gradle wrapper should not require bash

.drone.yml

@@ -0,0 +1,9 @@
+kind: pipeline
+name: default
+
+steps:
+- name: test
+  image: adoptopenjdk/openjdk8:alpine
+  commands:
+  - ./gradlew assemble
+  - ./gradlew check

.gitignore

@@ -49,7 +49,7 @@ gradle-app.setting
 ## Plugin-specific files:
 
 # IntelliJ
-out/
+/out/
 
 # mpeltonen/sbt-idea plugin
 .idea_modules/

README.md

@@ -9,7 +9,7 @@ A Java implementation for the Bitmessage protocol. To build, use command `./grad
 
 Please note that it still has its limitations, but the API should now be stable. Jabit uses Semantic Versioning, meaning as long as the major version doesn't change, nothing should break if you update.
 
-Be aware though that this doesn't necessarily applies for SNAPSHOT builds and the development branch, notably when it comes to database updates. In other words, they may break your installation!_ 
+Be aware though that this doesn't necessarily applies for SNAPSHOT builds and the development branch, notably when it comes to database updates. _In other words, they may break your installation!_ 
 
 #### Master
 [![Build Status](https://travis-ci.org/Dissem/Jabit.svg?branch=master)](https://travis-ci.org/Dissem/Jabit) 

build.gradle

@@ -1,38 +1,15 @@
-buildscript {
-    ext.kotlin_version = '1.2.71'
-    repositories {
-        mavenCentral()
-    }
-    dependencies {
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-    }
-}
-plugins {
-    id 'com.github.ben-manes.versions' version '0.17.0'
-    id "io.spring.dependency-management" version "1.0.4.RELEASE"
-}
-
 subprojects {
-    apply plugin: 'io.spring.dependency-management'
-    apply plugin: 'kotlin'
+    apply plugin: 'java'
     apply plugin: 'maven'
     apply plugin: 'signing'
     apply plugin: 'jacoco'
     apply plugin: 'gitflow-version'
-    apply plugin: 'com.github.ben-manes.versions'
 
     sourceCompatibility = 1.7
-    targetCompatibility = 1.7
     group = 'ch.dissem.jabit'
 
     repositories {
         mavenCentral()
-        maven { url 'https://oss.sonatype.org/content/repositories/snapshots/' }
-        jcenter()
-    }
-    dependencies {
-        implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7"
-        implementation "org.jetbrains.kotlin:kotlin-reflect"
     }
 
     test {
@@ -51,26 +28,10 @@ subprojects {
         from sourceSets.main.allSource
     }
 
-    compileKotlin {
-        kotlinOptions.jvmTarget = "1.6"
-    }
-
-    compileTestKotlin {
-        kotlinOptions.jvmTarget = "1.6"
-    }
-
     artifacts {
         archives javadocJar, sourcesJar
     }
 
-    jar {
-        manifest {
-            attributes 'Implementation-Title': "Jabit ${project.name.capitalize()}",
-                       'Implementation-Version': version
-        }
-        baseName "jabit-${project.name}"
-    }
-
     signing {
         required { isRelease && project.getProperties().get("signing.keyId")?.length() > 0 }
         sign configurations.archives
@@ -126,34 +87,4 @@ subprojects {
     }
 
     check.dependsOn jacocoTestReport
-
-    dependencyManagement {
-        dependencies {
-            dependencySet(group: 'org.jetbrains.kotlin', version: "$kotlin_version") {
-                entry 'kotlin-stdlib-jdk7'
-                entry 'kotlin-reflect'
-            }
-            dependencySet(group: 'org.slf4j', version: '1.7.25') {
-                entry 'slf4j-api'
-                entry 'slf4j-simple'
-            }
-
-            dependency 'ch.dissem.msgpack:msgpack:2.0.1'
-            dependency 'org.bouncycastle:bcprov-jdk15on:1.60'
-            dependency 'com.madgag.spongycastle:prov:1.58.0.0'
-            dependency 'org.apache.commons:commons-text:1.5'
-            dependency 'org.flywaydb:flyway-core:5.2.0'
-            dependency 'com.beust:klaxon:3.0.8'
-
-            dependency 'args4j:args4j:2.33'
-            dependency 'org.ini4j:ini4j:0.5.4'
-            dependency 'com.h2database:h2:1.4.197'
-
-            dependency 'org.hamcrest:java-hamcrest:2.0.0.0'
-            dependency 'com.nhaarman:mockito-kotlin:1.6.0'
-
-            dependency 'org.junit.jupiter:junit-jupiter-api:5.3.1'
-            dependency 'org.junit.jupiter:junit-jupiter-engine:5.3.1'
-        }
-    }
 }

buildSrc/src/main/groovy/ch/dissem/gradle/GitFlowVersion.groovy

@@ -50,8 +50,8 @@ class GitFlowVersion implements Plugin<Project> {
         project.ext.isRelease = isRelease(project)
         project.version = getVersion(project)
 
-        project.task('version') {
-            doLast { println "Version deduced from git: '${project.version}'" }
+        project.task('version') << {
+            println "Version deduced from git: '${project.version}'"
         }
     }
 }

core/build.gradle

@@ -24,28 +24,9 @@ artifacts {
 }
 
 dependencies {
-    compile 'org.slf4j:slf4j-api'
-    compile 'ch.dissem.msgpack:msgpack'
-    testCompile 'com.nhaarman:mockito-kotlin'
-    testCompile 'org.junit.jupiter:junit-jupiter-api'
-    testRuntime 'org.junit.jupiter:junit-jupiter-engine'
+    compile 'org.slf4j:slf4j-api:1.7.12'
+    testCompile 'junit:junit:4.12'
+    testCompile 'org.hamcrest:hamcrest-library:1.3'
+    testCompile 'org.mockito:mockito-core:1.10.19'
     testCompile project(':cryptography-bc')
 }
-
-def generatedResources = "${project.buildDir}/generated-resources/main"
-
-sourceSets {
-    main {
-        output.dir(generatedResources, builtBy: 'generateVersionInfo')
-    }
-}
-task('generateVersionInfo') {
-    doLast {
-        def dir = new File(generatedResources)
-        if (!dir.exists()) {
-            dir.mkdirs()
-        }
-        def file = new File(generatedResources, "version")
-        file.write(project.version.toString())
-    }
-}

core/src/main/java/ch/dissem/bitmessage/BitmessageContext.java

@@ -0,0 +1,451 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage;
+
+import ch.dissem.bitmessage.entity.*;
+import ch.dissem.bitmessage.entity.payload.Broadcast;
+import ch.dissem.bitmessage.entity.payload.ObjectType;
+import ch.dissem.bitmessage.entity.payload.Pubkey.Feature;
+import ch.dissem.bitmessage.entity.valueobject.PrivateKey;
+import ch.dissem.bitmessage.exception.DecryptionFailedException;
+import ch.dissem.bitmessage.factory.Factory;
+import ch.dissem.bitmessage.ports.*;
+import ch.dissem.bitmessage.utils.Property;
+import ch.dissem.bitmessage.utils.TTL;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.net.InetAddress;
+import java.util.List;
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+
+import static ch.dissem.bitmessage.InternalContext.NETWORK_EXTRA_BYTES;
+import static ch.dissem.bitmessage.InternalContext.NETWORK_NONCE_TRIALS_PER_BYTE;
+import static ch.dissem.bitmessage.entity.Plaintext.Type.BROADCAST;
+import static ch.dissem.bitmessage.entity.Plaintext.Type.MSG;
+import static ch.dissem.bitmessage.utils.UnixTime.*;
+
+/**
+ * <p>Use this class if you want to create a Bitmessage client.</p>
+ * You'll need the Builder to create a BitmessageContext, and set the following properties:
+ * <ul>
+ * <li>addressRepo</li>
+ * <li>inventory</li>
+ * <li>nodeRegistry</li>
+ * <li>networkHandler</li>
+ * <li>messageRepo</li>
+ * <li>streams</li>
+ * </ul>
+ * <p>The default implementations in the different module builds can be used.</p>
+ * <p>The port defaults to 8444 (the default Bitmessage port)</p>
+ */
+public class BitmessageContext {
+    public static final int CURRENT_VERSION = 3;
+    private final static Logger LOG = LoggerFactory.getLogger(BitmessageContext.class);
+
+    private final InternalContext ctx;
+
+    private final Labeler labeler;
+
+    private final boolean sendPubkeyOnIdentityCreation;
+
+    private BitmessageContext(Builder builder) {
+        if (builder.listener instanceof Listener.WithContext) {
+            ((Listener.WithContext) builder.listener).setContext(this);
+        }
+        ctx = new InternalContext(builder);
+        labeler = builder.labeler;
+        ctx.getProofOfWorkService().doMissingProofOfWork(30_000); // TODO: this should be configurable
+        sendPubkeyOnIdentityCreation = builder.sendPubkeyOnIdentityCreation;
+    }
+
+    public AddressRepository addresses() {
+        return ctx.getAddressRepository();
+    }
+
+    public MessageRepository messages() {
+        return ctx.getMessageRepository();
+    }
+
+    public Labeler labeler() {
+        return labeler;
+    }
+
+    public BitmessageAddress createIdentity(boolean shorter, Feature... features) {
+        final BitmessageAddress identity = new BitmessageAddress(new PrivateKey(
+            shorter,
+            ctx.getStreams()[0],
+            NETWORK_NONCE_TRIALS_PER_BYTE,
+            NETWORK_EXTRA_BYTES,
+            features
+        ));
+        ctx.getAddressRepository().save(identity);
+        if (sendPubkeyOnIdentityCreation) {
+            ctx.sendPubkey(identity, identity.getStream());
+        }
+        return identity;
+    }
+
+    public BitmessageAddress joinChan(String passphrase, String address) {
+        BitmessageAddress chan = BitmessageAddress.chan(address, passphrase);
+        chan.setAlias(passphrase);
+        ctx.getAddressRepository().save(chan);
+        return chan;
+    }
+
+    public BitmessageAddress createChan(String passphrase) {
+        // FIXME: hardcoded stream number
+        BitmessageAddress chan = BitmessageAddress.chan(1, passphrase);
+        ctx.getAddressRepository().save(chan);
+        return chan;
+    }
+
+    public List<BitmessageAddress> createDeterministicAddresses(
+        String passphrase, int numberOfAddresses, long version, long stream, boolean shorter) {
+        List<BitmessageAddress> result = BitmessageAddress.deterministic(
+            passphrase, numberOfAddresses, version, stream, shorter);
+        for (int i = 0; i < result.size(); i++) {
+            BitmessageAddress address = result.get(i);
+            address.setAlias("deterministic (" + (i + 1) + ")");
+            ctx.getAddressRepository().save(address);
+        }
+        return result;
+    }
+
+    public void broadcast(final BitmessageAddress from, final String subject, final String message) {
+        Plaintext msg = new Plaintext.Builder(BROADCAST)
+            .from(from)
+            .message(subject, message)
+            .build();
+        send(msg);
+    }
+
+    public void send(final BitmessageAddress from, final BitmessageAddress to, final String subject, final String message) {
+        if (from.getPrivateKey() == null) {
+            throw new IllegalArgumentException("'From' must be an identity, i.e. have a private key.");
+        }
+        Plaintext msg = new Plaintext.Builder(MSG)
+            .from(from)
+            .to(to)
+            .message(subject, message)
+            .build();
+        send(msg);
+    }
+
+    public void send(final Plaintext msg) {
+        if (msg.getFrom() == null || msg.getFrom().getPrivateKey() == null) {
+            throw new IllegalArgumentException("'From' must be an identity, i.e. have a private key.");
+        }
+        labeler().markAsSending(msg);
+        BitmessageAddress to = msg.getTo();
+        if (to != null) {
+            if (to.getPubkey() == null) {
+                LOG.info("Public key is missing from recipient. Requesting.");
+                ctx.requestPubkey(to);
+            }
+            if (to.getPubkey() == null) {
+                ctx.getMessageRepository().save(msg);
+            }
+        }
+        if (to == null || to.getPubkey() != null) {
+            LOG.info("Sending message.");
+            ctx.getMessageRepository().save(msg);
+            if (msg.getType() == MSG) {
+                ctx.send(msg);
+            } else {
+                ctx.send(
+                    msg.getFrom(),
+                    to,
+                    Factory.getBroadcast(msg),
+                    msg.getTTL()
+                );
+            }
+        }
+    }
+
+    public void startup() {
+        ctx.getNetworkHandler().start();
+    }
+
+    public void shutdown() {
+        ctx.getNetworkHandler().stop();
+    }
+
+    /**
+     * @param host             a trusted node that must be reliable (it's used for every synchronization)
+     * @param port             of the trusted host, default is 8444
+     * @param timeoutInSeconds synchronization should end no later than about 5 seconds after the timeout elapsed, even
+     *                         if not all objects were fetched
+     * @param wait             waits for the synchronization thread to finish
+     */
+    public void synchronize(InetAddress host, int port, long timeoutInSeconds, boolean wait) {
+        Future<?> future = ctx.getNetworkHandler().synchronize(host, port, timeoutInSeconds);
+        if (wait) {
+            try {
+                future.get();
+            } catch (InterruptedException e) {
+                LOG.info("Thread was interrupted. Trying to shut down synchronization and returning.");
+                future.cancel(true);
+            } catch (CancellationException | ExecutionException e) {
+                LOG.debug(e.getMessage(), e);
+            }
+        }
+    }
+
+    /**
+     * Send a custom message to a specific node (that should implement handling for this message type) and returns
+     * the response, which in turn is expected to be a {@link CustomMessage}.
+     *
+     * @param server  the node's address
+     * @param port    the node's port
+     * @param request the request
+     * @return the response
+     */
+    public CustomMessage send(InetAddress server, int port, CustomMessage request) {
+        return ctx.getNetworkHandler().send(server, port, request);
+    }
+
+    /**
+     * Removes expired objects from the inventory. You should call this method regularly,
+     * e.g. daily and on each shutdown.
+     */
+    public void cleanup() {
+        ctx.getInventory().cleanup();
+    }
+
+    /**
+     * Sends messages again whose time to live expired without being acknowledged. (And whose
+     * recipient is expected to send acknowledgements.
+     * <p>
+     * You should call this method regularly, but be aware of the following:
+     * <ul>
+     * <li>As messages might be sent, POW will be done. It is therefore not advised to
+     * call it on shutdown.</li>
+     * <li>It shouldn't be called right after startup, as it's possible the missing
+     * acknowledgement was sent while the client was offline.</li>
+     * <li>Other than that, the call isn't expensive as long as there is no message
+     * to send, so it might be a good idea to just call it every few minutes.</li>
+     * </ul>
+     */
+    public void resendUnacknowledgedMessages() {
+        ctx.resendUnacknowledged();
+    }
+
+    public boolean isRunning() {
+        return ctx.getNetworkHandler().isRunning();
+    }
+
+    public void addContact(BitmessageAddress contact) {
+        ctx.getAddressRepository().save(contact);
+        if (contact.getPubkey() == null) {
+            ctx.requestPubkey(contact);
+        }
+    }
+
+    public void addSubscribtion(BitmessageAddress address) {
+        address.setSubscribed(true);
+        ctx.getAddressRepository().save(address);
+        tryToFindBroadcastsForAddress(address);
+    }
+
+    private void tryToFindBroadcastsForAddress(BitmessageAddress address) {
+        for (ObjectMessage object : ctx.getInventory().getObjects(address.getStream(), Broadcast.getVersion(address), ObjectType.BROADCAST)) {
+            try {
+                Broadcast broadcast = (Broadcast) object.getPayload();
+                broadcast.decrypt(address);
+                // This decrypts it twice, but on the other hand it doesn't try to decrypt the objects with
+                // other subscriptions and the interface stays as simple as possible.
+                ctx.getNetworkListener().receive(object);
+            } catch (DecryptionFailedException ignore) {
+            } catch (Exception e) {
+                LOG.debug(e.getMessage(), e);
+            }
+        }
+    }
+
+    public Property status() {
+        return new Property("status", null,
+            ctx.getNetworkHandler().getNetworkStatus(),
+            new Property("unacknowledged", ctx.getMessageRepository().findMessagesToResend().size())
+        );
+    }
+
+    /**
+     * Returns the {@link InternalContext} - normally you wouldn't need it,
+     * unless you are doing something crazy with the protocol.
+     */
+    public InternalContext internals() {
+        return ctx;
+    }
+
+    public interface Listener {
+        void receive(Plaintext plaintext);
+
+        /**
+         * A message listener that needs a {@link BitmessageContext}, i.e. for implementing some sort of chat bot.
+         */
+        interface WithContext extends Listener {
+            void setContext(BitmessageContext ctx);
+        }
+    }
+
+    public static final class Builder {
+        int port = 8444;
+        Inventory inventory;
+        NodeRegistry nodeRegistry;
+        NetworkHandler networkHandler;
+        AddressRepository addressRepo;
+        MessageRepository messageRepo;
+        ProofOfWorkRepository proofOfWorkRepository;
+        ProofOfWorkEngine proofOfWorkEngine;
+        Cryptography cryptography;
+        CustomCommandHandler customCommandHandler;
+        Labeler labeler;
+        Listener listener;
+        int connectionLimit = 150;
+        long connectionTTL = 30 * MINUTE;
+        boolean sendPubkeyOnIdentityCreation = true;
+
+        public Builder port(int port) {
+            this.port = port;
+            return this;
+        }
+
+        public Builder inventory(Inventory inventory) {
+            this.inventory = inventory;
+            return this;
+        }
+
+        public Builder nodeRegistry(NodeRegistry nodeRegistry) {
+            this.nodeRegistry = nodeRegistry;
+            return this;
+        }
+
+        public Builder networkHandler(NetworkHandler networkHandler) {
+            this.networkHandler = networkHandler;
+            return this;
+        }
+
+        public Builder addressRepo(AddressRepository addressRepo) {
+            this.addressRepo = addressRepo;
+            return this;
+        }
+
+        public Builder messageRepo(MessageRepository messageRepo) {
+            this.messageRepo = messageRepo;
+            return this;
+        }
+
+        public Builder powRepo(ProofOfWorkRepository proofOfWorkRepository) {
+            this.proofOfWorkRepository = proofOfWorkRepository;
+            return this;
+        }
+
+        public Builder cryptography(Cryptography cryptography) {
+            this.cryptography = cryptography;
+            return this;
+        }
+
+        public Builder customCommandHandler(CustomCommandHandler handler) {
+            this.customCommandHandler = handler;
+            return this;
+        }
+
+        public Builder proofOfWorkEngine(ProofOfWorkEngine proofOfWorkEngine) {
+            this.proofOfWorkEngine = proofOfWorkEngine;
+            return this;
+        }
+
+        public Builder labeler(Labeler labeler) {
+            this.labeler = labeler;
+            return this;
+        }
+
+        public Builder listener(Listener listener) {
+            this.listener = listener;
+            return this;
+        }
+
+        public Builder connectionLimit(int connectionLimit) {
+            this.connectionLimit = connectionLimit;
+            return this;
+        }
+
+        public Builder connectionTTL(int hours) {
+            this.connectionTTL = hours * HOUR;
+            return this;
+        }
+
+        /**
+         * By default a client will send the public key when an identity is being created. On weaker devices
+         * this behaviour might not be desirable.
+         */
+        public Builder doNotSendPubkeyOnIdentityCreation() {
+            this.sendPubkeyOnIdentityCreation = false;
+            return this;
+        }
+
+        /**
+         * Time to live in seconds for public keys the client sends. Defaults to the maximum of 28 days,
+         * but on weak devices smaller values might be desirable.
+         * <p>
+         * Please be aware that this might cause some problems where you can't receive a message (the
+         * sender can't receive your public key) in some special situations. Also note that it's probably
+         * not a good idea to set it too low.
+         * </p>
+         *
+         * @deprecated use {@link TTL#pubkey(long)} instead.
+         */
+        public Builder pubkeyTTL(long days) {
+            if (days < 0 || days > 28 * DAY) throw new IllegalArgumentException("TTL must be between 1 and 28 days");
+            TTL.pubkey(days);
+            return this;
+        }
+
+        public BitmessageContext build() {
+            nonNull("inventory", inventory);
+            nonNull("nodeRegistry", nodeRegistry);
+            nonNull("networkHandler", networkHandler);
+            nonNull("addressRepo", addressRepo);
+            nonNull("messageRepo", messageRepo);
+            nonNull("proofOfWorkRepo", proofOfWorkRepository);
+            if (proofOfWorkEngine == null) {
+                proofOfWorkEngine = new MultiThreadedPOWEngine();
+            }
+            if (labeler == null) {
+                labeler = new DefaultLabeler();
+            }
+            if (customCommandHandler == null) {
+                customCommandHandler = new CustomCommandHandler() {
+                    @Override
+                    public MessagePayload handle(CustomMessage request) {
+                        throw new IllegalStateException(
+                            "Received custom request, but no custom command handler configured.");
+                    }
+                };
+            }
+            return new BitmessageContext(this);
+        }
+
+        private void nonNull(String name, Object o) {
+            if (o == null) throw new IllegalStateException(name + " must not be null");
+        }
+    }
+
+}

core/src/main/java/ch/dissem/bitmessage/DefaultMessageListener.java

@@ -0,0 +1,187 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage;
+
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.entity.Plaintext;
+import ch.dissem.bitmessage.entity.payload.*;
+import ch.dissem.bitmessage.entity.valueobject.InventoryVector;
+import ch.dissem.bitmessage.exception.DecryptionFailedException;
+import ch.dissem.bitmessage.ports.Labeler;
+import ch.dissem.bitmessage.ports.NetworkHandler;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+
+import static ch.dissem.bitmessage.entity.Plaintext.Status.PUBKEY_REQUESTED;
+
+class DefaultMessageListener implements NetworkHandler.MessageListener, InternalContext.ContextHolder {
+    private final static Logger LOG = LoggerFactory.getLogger(DefaultMessageListener.class);
+    private final Labeler labeler;
+    private final BitmessageContext.Listener listener;
+    private InternalContext ctx;
+
+    public DefaultMessageListener(Labeler labeler, BitmessageContext.Listener listener) {
+        this.labeler = labeler;
+        this.listener = listener;
+    }
+
+    @Override
+    public void setContext(InternalContext context) {
+        this.ctx = context;
+    }
+
+    @Override
+    @SuppressWarnings("ConstantConditions")
+    public void receive(ObjectMessage object) throws IOException {
+        ObjectPayload payload = object.getPayload();
+        if (payload.getType() == null) {
+            if (payload instanceof GenericPayload) {
+                receive((GenericPayload) payload);
+            }
+            return;
+        }
+
+        switch (payload.getType()) {
+            case GET_PUBKEY: {
+                receive(object, (GetPubkey) payload);
+                break;
+            }
+            case PUBKEY: {
+                receive(object, (Pubkey) payload);
+                break;
+            }
+            case MSG: {
+                receive(object, (Msg) payload);
+                break;
+            }
+            case BROADCAST: {
+                receive(object, (Broadcast) payload);
+                break;
+            }
+            default: {
+                throw new IllegalArgumentException("Unknown payload type " + payload.getType());
+            }
+        }
+    }
+
+    protected void receive(ObjectMessage object, GetPubkey getPubkey) {
+        BitmessageAddress identity = ctx.getAddressRepository().findIdentity(getPubkey.getRipeTag());
+        if (identity != null && identity.getPrivateKey() != null && !identity.isChan()) {
+            LOG.info("Got pubkey request for identity " + identity);
+            // FIXME: only send pubkey if it wasn't sent in the last 28 days
+            ctx.sendPubkey(identity, object.getStream());
+        }
+    }
+
+    protected void receive(ObjectMessage object, Pubkey pubkey) throws IOException {
+        BitmessageAddress address;
+        try {
+            if (pubkey instanceof V4Pubkey) {
+                V4Pubkey v4Pubkey = (V4Pubkey) pubkey;
+                address = ctx.getAddressRepository().findContact(v4Pubkey.getTag());
+                if (address != null) {
+                    v4Pubkey.decrypt(address.getPublicDecryptionKey());
+                }
+            } else {
+                address = ctx.getAddressRepository().findContact(pubkey.getRipe());
+            }
+            if (address != null) {
+                updatePubkey(address, pubkey);
+            }
+        } catch (DecryptionFailedException ignore) {
+        }
+    }
+
+    private void updatePubkey(BitmessageAddress address, Pubkey pubkey) {
+        address.setPubkey(pubkey);
+        LOG.info("Got pubkey for contact " + address);
+        ctx.getAddressRepository().save(address);
+        List<Plaintext> messages = ctx.getMessageRepository().findMessages(PUBKEY_REQUESTED, address);
+        LOG.info("Sending " + messages.size() + " messages for contact " + address);
+        for (Plaintext msg : messages) {
+            ctx.getLabeler().markAsSending(msg);
+            ctx.getMessageRepository().save(msg);
+            ctx.send(msg);
+        }
+    }
+
+    protected void receive(ObjectMessage object, Msg msg) throws IOException {
+        for (BitmessageAddress identity : ctx.getAddressRepository().getIdentities()) {
+            try {
+                msg.decrypt(identity.getPrivateKey().getPrivateEncryptionKey());
+                Plaintext plaintext = msg.getPlaintext();
+                plaintext.setTo(identity);
+                if (!object.isSignatureValid(plaintext.getFrom().getPubkey())) {
+                    LOG.warn("Msg with IV " + object.getInventoryVector() + " was successfully decrypted, but signature check failed. Ignoring.");
+                } else {
+                    receive(object.getInventoryVector(), plaintext);
+                }
+                break;
+            } catch (DecryptionFailedException ignore) {
+            }
+        }
+    }
+
+    protected void receive(GenericPayload ack) {
+        if (ack.getData().length == Msg.ACK_LENGTH) {
+            Plaintext msg = ctx.getMessageRepository().getMessageForAck(ack.getData());
+            if (msg != null) {
+                ctx.getLabeler().markAsAcknowledged(msg);
+                ctx.getMessageRepository().save(msg);
+            }
+        }
+    }
+
+    protected void receive(ObjectMessage object, Broadcast broadcast) throws IOException {
+        byte[] tag = broadcast instanceof V5Broadcast ? ((V5Broadcast) broadcast).getTag() : null;
+        for (BitmessageAddress subscription : ctx.getAddressRepository().getSubscriptions(broadcast.getVersion())) {
+            if (tag != null && !Arrays.equals(tag, subscription.getTag())) {
+                continue;
+            }
+            try {
+                broadcast.decrypt(subscription.getPublicDecryptionKey());
+                if (!object.isSignatureValid(broadcast.getPlaintext().getFrom().getPubkey())) {
+                    LOG.warn("Broadcast with IV " + object.getInventoryVector() + " was successfully decrypted, but signature check failed. Ignoring.");
+                } else {
+                    receive(object.getInventoryVector(), broadcast.getPlaintext());
+                }
+            } catch (DecryptionFailedException ignore) {
+            }
+        }
+    }
+
+    protected void receive(InventoryVector iv, Plaintext msg) {
+        msg.setInventoryVector(iv);
+        labeler.setLabels(msg);
+        ctx.getMessageRepository().save(msg);
+        listener.receive(msg);
+        updatePubkey(msg.getFrom(), msg.getFrom().getPubkey());
+
+        if (msg.getType() == Plaintext.Type.MSG && msg.getTo().has(Pubkey.Feature.DOES_ACK)) {
+            ObjectMessage ack = msg.getAckMessage();
+            if (ack != null) {
+                ctx.getInventory().storeObject(ack);
+                ctx.getNetworkHandler().offer(ack.getInventoryVector());
+            }
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/InternalContext.java

@@ -0,0 +1,317 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage;
+
+import ch.dissem.bitmessage.entity.*;
+import ch.dissem.bitmessage.entity.payload.*;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.ports.*;
+import ch.dissem.bitmessage.utils.Singleton;
+import ch.dissem.bitmessage.utils.TTL;
+import ch.dissem.bitmessage.utils.UnixTime;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.TreeSet;
+
+/**
+ * The internal context should normally only be used for port implementations. If you need it in your client
+ * implementation, you're either doing something wrong, something very weird, or the BitmessageContext should
+ * get extended.
+ * <p>
+ * On the other hand, if you need the BitmessageContext in a port implementation, the same thing might apply.
+ * </p>
+ */
+public class InternalContext {
+    private final static Logger LOG = LoggerFactory.getLogger(InternalContext.class);
+
+    public final static long NETWORK_NONCE_TRIALS_PER_BYTE = 1000;
+    public final static long NETWORK_EXTRA_BYTES = 1000;
+
+    private final Cryptography cryptography;
+    private final Inventory inventory;
+    private final NodeRegistry nodeRegistry;
+    private final NetworkHandler networkHandler;
+    private final AddressRepository addressRepository;
+    private final MessageRepository messageRepository;
+    private final ProofOfWorkRepository proofOfWorkRepository;
+    private final ProofOfWorkEngine proofOfWorkEngine;
+    private final CustomCommandHandler customCommandHandler;
+    private final ProofOfWorkService proofOfWorkService;
+    private final Labeler labeler;
+    private final NetworkHandler.MessageListener networkListener;
+
+    private final TreeSet<Long> streams = new TreeSet<>();
+    private final int port;
+    private final long clientNonce;
+    private long connectionTTL;
+    private int connectionLimit;
+
+    public InternalContext(BitmessageContext.Builder builder) {
+        this.cryptography = builder.cryptography;
+        this.inventory = builder.inventory;
+        this.nodeRegistry = builder.nodeRegistry;
+        this.networkHandler = builder.networkHandler;
+        this.addressRepository = builder.addressRepo;
+        this.messageRepository = builder.messageRepo;
+        this.proofOfWorkRepository = builder.proofOfWorkRepository;
+        this.proofOfWorkService = new ProofOfWorkService();
+        this.proofOfWorkEngine = builder.proofOfWorkEngine;
+        this.clientNonce = cryptography.randomNonce();
+        this.customCommandHandler = builder.customCommandHandler;
+        this.port = builder.port;
+        this.connectionLimit = builder.connectionLimit;
+        this.connectionTTL = builder.connectionTTL;
+        this.labeler = builder.labeler;
+        this.networkListener = new DefaultMessageListener(labeler, builder.listener);
+
+        Singleton.initialize(cryptography);
+
+        // TODO: streams of new identities and subscriptions should also be added. This works only after a restart.
+        for (BitmessageAddress address : addressRepository.getIdentities()) {
+            streams.add(address.getStream());
+        }
+        for (BitmessageAddress address : addressRepository.getSubscriptions()) {
+            streams.add(address.getStream());
+        }
+        if (streams.isEmpty()) {
+            streams.add(1L);
+        }
+
+        init(cryptography, inventory, nodeRegistry, networkHandler, addressRepository, messageRepository,
+            proofOfWorkRepository, proofOfWorkService, proofOfWorkEngine, customCommandHandler, builder.labeler,
+            networkListener);
+        for (BitmessageAddress identity : addressRepository.getIdentities()) {
+            streams.add(identity.getStream());
+        }
+    }
+
+    private void init(Object... objects) {
+        for (Object o : objects) {
+            if (o instanceof ContextHolder) {
+                ((ContextHolder) o).setContext(this);
+            }
+        }
+    }
+
+    public Cryptography getCryptography() {
+        return cryptography;
+    }
+
+    public Inventory getInventory() {
+        return inventory;
+    }
+
+    public NodeRegistry getNodeRegistry() {
+        return nodeRegistry;
+    }
+
+    public NetworkHandler getNetworkHandler() {
+        return networkHandler;
+    }
+
+    public AddressRepository getAddressRepository() {
+        return addressRepository;
+    }
+
+    public MessageRepository getMessageRepository() {
+        return messageRepository;
+    }
+
+    public ProofOfWorkRepository getProofOfWorkRepository() {
+        return proofOfWorkRepository;
+    }
+
+    public ProofOfWorkEngine getProofOfWorkEngine() {
+        return proofOfWorkEngine;
+    }
+
+    public ProofOfWorkService getProofOfWorkService() {
+        return proofOfWorkService;
+    }
+
+    public Labeler getLabeler() {
+        return labeler;
+    }
+
+    public NetworkHandler.MessageListener getNetworkListener() {
+        return networkListener;
+    }
+
+    public long[] getStreams() {
+        long[] result = new long[streams.size()];
+        int i = 0;
+        for (long stream : streams) {
+            result[i++] = stream;
+        }
+        return result;
+    }
+
+    public int getPort() {
+        return port;
+    }
+
+    public void send(final Plaintext plaintext) {
+        if (plaintext.getAckMessage() != null) {
+            long expires = UnixTime.now(+plaintext.getTTL());
+            LOG.info("Expires at " + expires);
+            proofOfWorkService.doProofOfWorkWithAck(plaintext, expires);
+        } else {
+            send(plaintext.getFrom(), plaintext.getTo(), new Msg(plaintext), plaintext.getTTL());
+        }
+    }
+
+    public void send(final BitmessageAddress from, BitmessageAddress to, final ObjectPayload payload,
+                     final long timeToLive) {
+        try {
+            final BitmessageAddress recipient = (to != null ? to : from);
+            long expires = UnixTime.now(+timeToLive);
+            LOG.info("Expires at " + expires);
+            final ObjectMessage object = new ObjectMessage.Builder()
+                .stream(recipient.getStream())
+                .expiresTime(expires)
+                .payload(payload)
+                .build();
+            if (object.isSigned()) {
+                object.sign(from.getPrivateKey());
+            }
+            if (payload instanceof Broadcast) {
+                ((Broadcast) payload).encrypt();
+            } else if (payload instanceof Encrypted) {
+                object.encrypt(recipient.getPubkey());
+            }
+            proofOfWorkService.doProofOfWork(to, object);
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public void sendPubkey(final BitmessageAddress identity, final long targetStream) {
+        try {
+            long expires = UnixTime.now(TTL.pubkey());
+            LOG.info("Expires at " + expires);
+            final ObjectMessage response = new ObjectMessage.Builder()
+                .stream(targetStream)
+                .expiresTime(expires)
+                .payload(identity.getPubkey())
+                .build();
+            response.sign(identity.getPrivateKey());
+            response.encrypt(cryptography.createPublicKey(identity.getPublicDecryptionKey()));
+            // TODO: remember that the pubkey is just about to be sent, and on which stream!
+            proofOfWorkService.doProofOfWork(response);
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    /**
+     * Be aware that if the pubkey already exists in the inventory, the metods will not request it and the callback
+     * for freshly received pubkeys will not be called. Instead the pubkey is added to the contact and stored on DB.
+     */
+    public void requestPubkey(final BitmessageAddress contact) {
+        BitmessageAddress stored = addressRepository.getAddress(contact.getAddress());
+
+        tryToFindMatchingPubkey(contact);
+        if (contact.getPubkey() != null) {
+            if (stored != null) {
+                stored.setPubkey(contact.getPubkey());
+                addressRepository.save(stored);
+            } else {
+                addressRepository.save(contact);
+            }
+            return;
+        }
+
+        if (stored == null) {
+            addressRepository.save(contact);
+        }
+
+        long expires = UnixTime.now(TTL.getpubkey());
+        LOG.info("Expires at " + expires);
+        final ObjectMessage request = new ObjectMessage.Builder()
+            .stream(contact.getStream())
+            .expiresTime(expires)
+            .payload(new GetPubkey(contact))
+            .build();
+        proofOfWorkService.doProofOfWork(request);
+    }
+
+    private void tryToFindMatchingPubkey(BitmessageAddress address) {
+        BitmessageAddress stored = addressRepository.getAddress(address.getAddress());
+        if (stored != null) {
+            address.setAlias(stored.getAlias());
+            address.setSubscribed(stored.isSubscribed());
+        }
+        for (ObjectMessage object : inventory.getObjects(address.getStream(), address.getVersion(), ObjectType.PUBKEY)) {
+            try {
+                Pubkey pubkey = (Pubkey) object.getPayload();
+                if (address.getVersion() == 4) {
+                    V4Pubkey v4Pubkey = (V4Pubkey) pubkey;
+                    if (Arrays.equals(address.getTag(), v4Pubkey.getTag())) {
+                        v4Pubkey.decrypt(address.getPublicDecryptionKey());
+                        if (object.isSignatureValid(v4Pubkey)) {
+                            address.setPubkey(v4Pubkey);
+                            addressRepository.save(address);
+                            break;
+                        } else {
+                            LOG.info("Found pubkey for " + address + " but signature is invalid");
+                        }
+                    }
+                } else {
+                    if (Arrays.equals(pubkey.getRipe(), address.getRipe())) {
+                        address.setPubkey(pubkey);
+                        addressRepository.save(address);
+                        break;
+                    }
+                }
+            } catch (Exception e) {
+                LOG.debug(e.getMessage(), e);
+            }
+        }
+    }
+
+    public void resendUnacknowledged() {
+        List<Plaintext> messages = messageRepository.findMessagesToResend();
+        for (Plaintext message : messages) {
+            send(message);
+            messageRepository.save(message);
+        }
+    }
+
+    public long getClientNonce() {
+        return clientNonce;
+    }
+
+    public long getConnectionTTL() {
+        return connectionTTL;
+    }
+
+    public int getConnectionLimit() {
+        return connectionLimit;
+    }
+
+    public CustomCommandHandler getCustomCommandHandler() {
+        return customCommandHandler;
+    }
+
+    public interface ContextHolder {
+        void setContext(InternalContext context);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/ProofOfWorkService.java

@@ -0,0 +1,125 @@
+package ch.dissem.bitmessage;
+
+import ch.dissem.bitmessage.entity.*;
+import ch.dissem.bitmessage.entity.payload.Msg;
+import ch.dissem.bitmessage.entity.payload.Pubkey;
+import ch.dissem.bitmessage.ports.Cryptography;
+import ch.dissem.bitmessage.ports.MessageRepository;
+import ch.dissem.bitmessage.ports.ProofOfWorkEngine;
+import ch.dissem.bitmessage.ports.ProofOfWorkRepository;
+import ch.dissem.bitmessage.ports.ProofOfWorkRepository.Item;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Timer;
+import java.util.TimerTask;
+
+import static ch.dissem.bitmessage.InternalContext.NETWORK_EXTRA_BYTES;
+import static ch.dissem.bitmessage.InternalContext.NETWORK_NONCE_TRIALS_PER_BYTE;
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * @author Christian Basler
+ */
+public class ProofOfWorkService implements ProofOfWorkEngine.Callback, InternalContext.ContextHolder {
+    private final static Logger LOG = LoggerFactory.getLogger(ProofOfWorkService.class);
+
+    private Cryptography cryptography;
+    private InternalContext ctx;
+    private ProofOfWorkRepository powRepo;
+    private MessageRepository messageRepo;
+
+    public void doMissingProofOfWork(long delayInMilliseconds) {
+        final List<byte[]> items = powRepo.getItems();
+        if (items.isEmpty()) return;
+
+        // Wait for 30 seconds, to let the application start up before putting heavy load on the CPU
+        new Timer().schedule(new TimerTask() {
+            @Override
+            public void run() {
+                LOG.info("Doing POW for " + items.size() + " tasks.");
+                for (byte[] initialHash : items) {
+                    Item item = powRepo.getItem(initialHash);
+                    cryptography.doProofOfWork(item.object, item.nonceTrialsPerByte, item.extraBytes,
+                        ProofOfWorkService.this);
+                }
+            }
+        }, delayInMilliseconds);
+    }
+
+    public void doProofOfWork(ObjectMessage object) {
+        doProofOfWork(null, object);
+    }
+
+    public void doProofOfWork(BitmessageAddress recipient, ObjectMessage object) {
+        Pubkey pubkey = recipient == null ? null : recipient.getPubkey();
+
+        long nonceTrialsPerByte = pubkey == null ? NETWORK_NONCE_TRIALS_PER_BYTE : pubkey.getNonceTrialsPerByte();
+        long extraBytes = pubkey == null ? NETWORK_EXTRA_BYTES : pubkey.getExtraBytes();
+
+        powRepo.putObject(object, nonceTrialsPerByte, extraBytes);
+        if (object.getPayload() instanceof PlaintextHolder) {
+            Plaintext plaintext = ((PlaintextHolder) object.getPayload()).getPlaintext();
+            plaintext.setInitialHash(cryptography.getInitialHash(object));
+            messageRepo.save(plaintext);
+        }
+        cryptography.doProofOfWork(object, nonceTrialsPerByte, extraBytes, this);
+    }
+
+    public void doProofOfWorkWithAck(Plaintext plaintext, long expirationTime) {
+        final ObjectMessage ack = plaintext.getAckMessage();
+        messageRepo.save(plaintext);
+        Item item = new Item(ack, NETWORK_NONCE_TRIALS_PER_BYTE, NETWORK_EXTRA_BYTES,
+            expirationTime, plaintext);
+        powRepo.putObject(item);
+        cryptography.doProofOfWork(ack, NETWORK_NONCE_TRIALS_PER_BYTE, NETWORK_EXTRA_BYTES, this);
+    }
+
+    @Override
+    public void onNonceCalculated(byte[] initialHash, byte[] nonce) {
+        Item item = powRepo.getItem(initialHash);
+        if (item.message == null) {
+            ObjectMessage object = powRepo.getItem(initialHash).object;
+            object.setNonce(nonce);
+            Plaintext plaintext = messageRepo.getMessage(initialHash);
+            if (plaintext != null) {
+                plaintext.setInventoryVector(object.getInventoryVector());
+                plaintext.updateNextTry();
+                ctx.getLabeler().markAsSent(plaintext);
+                messageRepo.save(plaintext);
+            }
+            try {
+                ctx.getNetworkListener().receive(object);
+            } catch (IOException e) {
+                LOG.debug(e.getMessage(), e);
+            }
+            ctx.getInventory().storeObject(object);
+            ctx.getNetworkHandler().offer(object.getInventoryVector());
+        } else {
+            item.message.getAckMessage().setNonce(nonce);
+            final ObjectMessage object = new ObjectMessage.Builder()
+                .stream(item.message.getStream())
+                .expiresTime(item.expirationTime)
+                .payload(new Msg(item.message))
+                .build();
+            if (object.isSigned()) {
+                object.sign(item.message.getFrom().getPrivateKey());
+            }
+            if (object.getPayload() instanceof Encrypted) {
+                object.encrypt(item.message.getTo().getPubkey());
+            }
+            doProofOfWork(item.message.getTo(), object);
+        }
+        powRepo.removeObject(initialHash);
+    }
+
+    @Override
+    public void setContext(InternalContext ctx) {
+        this.ctx = ctx;
+        this.cryptography = cryptography();
+        this.powRepo = ctx.getProofOfWorkRepository();
+        this.messageRepo = ctx.getMessageRepository();
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/Addr.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import ch.dissem.bitmessage.entity.valueobject.NetworkAddress;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+/**
+ * The 'addr' command holds a list of known active Bitmessage nodes.
+ */
+public class Addr implements MessagePayload {
+    private static final long serialVersionUID = -5117688017050138720L;
+
+    private final List<NetworkAddress> addresses;
+
+    private Addr(Builder builder) {
+        addresses = builder.addresses;
+    }
+
+    @Override
+    public Command getCommand() {
+        return Command.ADDR;
+    }
+
+    public List<NetworkAddress> getAddresses() {
+        return addresses;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        Encode.varInt(addresses.size(), out);
+        for (NetworkAddress address : addresses) {
+            address.write(out);
+        }
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        Encode.varInt(addresses.size(), buffer);
+        for (NetworkAddress address : addresses) {
+            address.write(buffer);
+        }
+    }
+
+    public static final class Builder {
+        private List<NetworkAddress> addresses = new ArrayList<>();
+
+        public Builder addresses(Collection<NetworkAddress> addresses){
+            this.addresses.addAll(addresses);
+            return this;
+        }
+
+        public Builder addAddress(final NetworkAddress address) {
+            this.addresses.add(address);
+            return this;
+        }
+
+        public Addr build() {
+            return new Addr(this);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/BitmessageAddress.java

@@ -0,0 +1,277 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import ch.dissem.bitmessage.entity.payload.Pubkey;
+import ch.dissem.bitmessage.entity.payload.Pubkey.Feature;
+import ch.dissem.bitmessage.entity.payload.V4Pubkey;
+import ch.dissem.bitmessage.entity.valueobject.PrivateKey;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.utils.AccessCounter;
+import ch.dissem.bitmessage.utils.Base58;
+import ch.dissem.bitmessage.utils.Bytes;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.Serializable;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Objects;
+
+import static ch.dissem.bitmessage.utils.Decode.bytes;
+import static ch.dissem.bitmessage.utils.Decode.varInt;
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * A Bitmessage address. Can be a user's private address, an address string without public keys or a recipient's address
+ * holding private keys.
+ */
+public class BitmessageAddress implements Serializable {
+    private static final long serialVersionUID = 2386328540805994064L;
+
+    private final long version;
+    private final long stream;
+    private final byte[] ripe;
+    private final byte[] tag;
+    /**
+     * Used for V4 address encryption. It's easier to just create it regardless of address version.
+     */
+    private final byte[] publicDecryptionKey;
+
+    private String address;
+
+    private PrivateKey privateKey;
+    private Pubkey pubkey;
+
+    private String alias;
+    private boolean subscribed;
+    private boolean chan;
+
+    BitmessageAddress(long version, long stream, byte[] ripe) {
+        try {
+            this.version = version;
+            this.stream = stream;
+            this.ripe = ripe;
+
+            ByteArrayOutputStream os = new ByteArrayOutputStream();
+            Encode.varInt(version, os);
+            Encode.varInt(stream, os);
+            if (version < 4) {
+                byte[] checksum = cryptography().sha512(os.toByteArray(), ripe);
+                this.tag = null;
+                this.publicDecryptionKey = Arrays.copyOfRange(checksum, 0, 32);
+            } else {
+                // for tag and decryption key, the checksum has to be created with 0x00 padding
+                byte[] checksum = cryptography().doubleSha512(os.toByteArray(), ripe);
+                this.tag = Arrays.copyOfRange(checksum, 32, 64);
+                this.publicDecryptionKey = Arrays.copyOfRange(checksum, 0, 32);
+            }
+            // but for the address and its checksum they need to be stripped
+            int offset = Bytes.numberOfLeadingZeros(ripe);
+            os.write(ripe, offset, ripe.length - offset);
+            byte[] checksum = cryptography().doubleSha512(os.toByteArray());
+            os.write(checksum, 0, 4);
+            this.address = "BM-" + Base58.encode(os.toByteArray());
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public BitmessageAddress(Pubkey publicKey) {
+        this(publicKey.getVersion(), publicKey.getStream(), publicKey.getRipe());
+        this.pubkey = publicKey;
+    }
+
+    public BitmessageAddress(String address, String passphrase) {
+        this(address);
+        this.privateKey = new PrivateKey(this, passphrase);
+        this.pubkey = this.privateKey.getPubkey();
+        if (!Arrays.equals(ripe, privateKey.getPubkey().getRipe())) {
+            throw new IllegalArgumentException("Wrong address or passphrase");
+        }
+    }
+
+    public static BitmessageAddress chan(String address, String passphrase) {
+        BitmessageAddress result = new BitmessageAddress(address, passphrase);
+        result.chan = true;
+        return result;
+    }
+
+    public static BitmessageAddress chan(long stream, String passphrase) {
+        PrivateKey privateKey = new PrivateKey(Pubkey.LATEST_VERSION, stream, passphrase);
+        BitmessageAddress result = new BitmessageAddress(privateKey);
+        result.chan = true;
+        return result;
+    }
+
+    public static List<BitmessageAddress> deterministic(String passphrase, int numberOfAddresses,
+                                                        long version, long stream, boolean shorter) {
+        List<BitmessageAddress> result = new ArrayList<>(numberOfAddresses);
+        List<PrivateKey> privateKeys = PrivateKey.deterministic(passphrase, numberOfAddresses, version, stream, shorter);
+        for (PrivateKey pk : privateKeys) {
+            result.add(new BitmessageAddress(pk));
+        }
+        return result;
+    }
+
+    public BitmessageAddress(PrivateKey privateKey) {
+        this(privateKey.getPubkey());
+        this.privateKey = privateKey;
+    }
+
+    public BitmessageAddress(String address) {
+        try {
+            this.address = address;
+            byte[] bytes = Base58.decode(address.substring(3));
+            ByteArrayInputStream in = new ByteArrayInputStream(bytes);
+            AccessCounter counter = new AccessCounter();
+            this.version = varInt(in, counter);
+            this.stream = varInt(in, counter);
+            this.ripe = Bytes.expand(bytes(in, bytes.length - counter.length() - 4), 20);
+
+            // test checksum
+            byte[] checksum = cryptography().doubleSha512(bytes, bytes.length - 4);
+            byte[] expectedChecksum = bytes(in, 4);
+            for (int i = 0; i < 4; i++) {
+                if (expectedChecksum[i] != checksum[i])
+                    throw new IllegalArgumentException("Checksum of address failed");
+            }
+            if (version < 4) {
+                checksum = cryptography().sha512(Arrays.copyOfRange(bytes, 0, counter.length()), ripe);
+                this.tag = null;
+                this.publicDecryptionKey = Arrays.copyOfRange(checksum, 0, 32);
+            } else {
+                checksum = cryptography().doubleSha512(Arrays.copyOfRange(bytes, 0, counter.length()), ripe);
+                this.tag = Arrays.copyOfRange(checksum, 32, 64);
+                this.publicDecryptionKey = Arrays.copyOfRange(checksum, 0, 32);
+            }
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public static byte[] calculateTag(long version, long stream, byte[] ripe) {
+        try {
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+            Encode.varInt(version, out);
+            Encode.varInt(stream, out);
+            out.write(ripe);
+            return Arrays.copyOfRange(cryptography().doubleSha512(out.toByteArray()), 32, 64);
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public long getStream() {
+        return stream;
+    }
+
+    public long getVersion() {
+        return version;
+    }
+
+    public Pubkey getPubkey() {
+        return pubkey;
+    }
+
+    public void setPubkey(Pubkey pubkey) {
+        if (pubkey instanceof V4Pubkey) {
+            if (!Arrays.equals(tag, ((V4Pubkey) pubkey).getTag()))
+                throw new IllegalArgumentException("Pubkey has incompatible tag");
+        }
+        if (!Arrays.equals(ripe, pubkey.getRipe()))
+            throw new IllegalArgumentException("Pubkey has incompatible ripe");
+        this.pubkey = pubkey;
+    }
+
+    /**
+     * @return the private key used to decrypt Pubkey objects (for v4 addresses) and broadcasts.
+     */
+    public byte[] getPublicDecryptionKey() {
+        return publicDecryptionKey;
+    }
+
+    public PrivateKey getPrivateKey() {
+        return privateKey;
+    }
+
+    public String getAddress() {
+        return address;
+    }
+
+    public String getAlias() {
+        return alias;
+    }
+
+    public void setAlias(String alias) {
+        this.alias = alias;
+    }
+
+    @Override
+    public String toString() {
+        return alias == null ? address : alias;
+    }
+
+    public byte[] getRipe() {
+        return ripe;
+    }
+
+    public byte[] getTag() {
+        return tag;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        BitmessageAddress address = (BitmessageAddress) o;
+        return Objects.equals(version, address.version) &&
+                Objects.equals(stream, address.stream) &&
+                Arrays.equals(ripe, address.ripe);
+    }
+
+    @Override
+    public int hashCode() {
+        return Arrays.hashCode(ripe);
+    }
+
+    public boolean isSubscribed() {
+        return subscribed;
+    }
+
+    public void setSubscribed(boolean subscribed) {
+        this.subscribed = subscribed;
+    }
+
+    public boolean isChan() {
+        return chan;
+    }
+
+    public void setChan(boolean chan) {
+        this.chan = chan;
+    }
+
+    public boolean has(Feature feature) {
+        if (pubkey == null || feature == null) {
+            return false;
+        }
+        return feature.isActive(pubkey.getBehaviorBitfield());
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/CustomMessage.java

@@ -0,0 +1,111 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.utils.AccessCounter;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.*;
+import java.nio.ByteBuffer;
+
+import static ch.dissem.bitmessage.utils.Decode.bytes;
+import static ch.dissem.bitmessage.utils.Decode.varString;
+
+/**
+ * @author Christian Basler
+ */
+public class CustomMessage implements MessagePayload {
+    private static final long serialVersionUID = -8932056829480326011L;
+
+    public static final String COMMAND_ERROR = "ERROR";
+
+    private final String command;
+    private final byte[] data;
+
+    public CustomMessage(String command) {
+        this.command = command;
+        this.data = null;
+    }
+
+    public CustomMessage(String command, byte[] data) {
+        this.command = command;
+        this.data = data;
+    }
+
+    public static CustomMessage read(InputStream in, int length) throws IOException {
+        AccessCounter counter = new AccessCounter();
+        return new CustomMessage(varString(in, counter), bytes(in, length - counter.length()));
+    }
+
+    @Override
+    public Command getCommand() {
+        return Command.CUSTOM;
+    }
+
+    public String getCustomCommand() {
+        return command;
+    }
+
+    public byte[] getData() {
+        if (data != null) {
+            return data;
+        } else {
+            try {
+                ByteArrayOutputStream out = new ByteArrayOutputStream();
+                write(out);
+                return out.toByteArray();
+            } catch (IOException e) {
+                throw new ApplicationException(e);
+            }
+        }
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        if (data != null) {
+            Encode.varString(command, out);
+            out.write(data);
+        } else {
+            throw new ApplicationException("Tried to write custom message without data. " +
+                    "Programmer: did you forget to override #write()?");
+        }
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        if (data != null) {
+            Encode.varString(command, buffer);
+            buffer.put(data);
+        } else {
+            throw new ApplicationException("Tried to write custom message without data. " +
+                    "Programmer: did you forget to override #write()?");
+        }
+    }
+
+    public boolean isError() {
+        return COMMAND_ERROR.equals(command);
+    }
+
+    public static CustomMessage error(String message) {
+        try {
+            return new CustomMessage(COMMAND_ERROR, message.getBytes("UTF-8"));
+        } catch (UnsupportedEncodingException e) {
+            throw new ApplicationException(e);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/Encrypted.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,18 +14,19 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.entity
+package ch.dissem.bitmessage.entity;
 
-import ch.dissem.bitmessage.exception.DecryptionFailedException
+import ch.dissem.bitmessage.exception.DecryptionFailedException;
+
+import java.io.IOException;
 
 /**
  * Used for objects that have encrypted content
  */
-interface Encrypted {
-    fun encrypt(publicKey: ByteArray)
+public interface Encrypted {
+    void encrypt(byte[] publicKey) throws IOException;
 
-    @Throws(DecryptionFailedException::class)
-    fun decrypt(privateKey: ByteArray)
+    void decrypt(byte[] privateKey) throws IOException, DecryptionFailedException;
 
-    val isDecrypted: Boolean
+    boolean isDecrypted();
 }

core/src/main/java/ch/dissem/bitmessage/entity/GetData.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import ch.dissem.bitmessage.entity.valueobject.InventoryVector;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * The 'getdata' command is used to request objects from a node.
+ */
+public class GetData implements MessagePayload {
+    private static final long serialVersionUID = 1433878785969631061L;
+
+    public static final int MAX_INVENTORY_SIZE = 50_000;
+
+    List<InventoryVector> inventory;
+
+    private GetData(Builder builder) {
+        inventory = builder.inventory;
+    }
+
+    @Override
+    public Command getCommand() {
+        return Command.GETDATA;
+    }
+
+    public List<InventoryVector> getInventory() {
+        return inventory;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        Encode.varInt(inventory.size(), out);
+        for (InventoryVector iv : inventory) {
+            iv.write(out);
+        }
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        Encode.varInt(inventory.size(), buffer);
+        for (InventoryVector iv : inventory) {
+            iv.write(buffer);
+        }
+    }
+
+    public static final class Builder {
+        private List<InventoryVector> inventory = new LinkedList<>();
+
+        public Builder addInventoryVector(InventoryVector inventoryVector) {
+            this.inventory.add(inventoryVector);
+            return this;
+        }
+
+        public Builder inventory(List<InventoryVector> inventory) {
+            this.inventory = inventory;
+            return this;
+        }
+
+        public GetData build() {
+            return new GetData(this);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/Inv.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import ch.dissem.bitmessage.entity.valueobject.InventoryVector;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * The 'inv' command holds up to 50000 inventory vectors, i.e. hashes of inventory items.
+ */
+public class Inv implements MessagePayload {
+    private static final long serialVersionUID = 3662992522956947145L;
+
+    private List<InventoryVector> inventory;
+
+    private Inv(Builder builder) {
+        inventory = builder.inventory;
+    }
+
+    public List<InventoryVector> getInventory() {
+        return inventory;
+    }
+
+    @Override
+    public Command getCommand() {
+        return Command.INV;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        Encode.varInt(inventory.size(), out);
+        for (InventoryVector iv : inventory) {
+            iv.write(out);
+        }
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        Encode.varInt(inventory.size(), buffer);
+        for (InventoryVector iv : inventory) {
+            iv.write(buffer);
+        }
+    }
+
+    public static final class Builder {
+        private List<InventoryVector> inventory = new LinkedList<>();
+
+        public Builder addInventoryVector(InventoryVector inventoryVector) {
+            this.inventory.add(inventoryVector);
+            return this;
+        }
+
+        public Builder inventory(List<InventoryVector> inventory) {
+            this.inventory = inventory;
+            return this;
+        }
+
+        public Inv build() {
+            return new Inv(this);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/MessagePayload.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,15 +14,15 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.entity
+package ch.dissem.bitmessage.entity;
 
 /**
  * A command can hold a network message payload
  */
-interface MessagePayload : Streamable {
-    val command: Command
+public interface MessagePayload extends Streamable {
+    Command getCommand();
 
-    enum class Command {
+    enum Command {
         VERSION, VERACK, ADDR, INV, GETDATA, OBJECT, CUSTOM
     }
 }

core/src/main/java/ch/dissem/bitmessage/entity/NetworkMessage.java

@@ -0,0 +1,151 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.UnsupportedEncodingException;
+import java.nio.ByteBuffer;
+import java.security.GeneralSecurityException;
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * A network message is exchanged between two nodes.
+ */
+public class NetworkMessage implements Streamable {
+    private static final long serialVersionUID = 702708857104464809L;
+
+    /**
+     * Magic value indicating message origin network, and used to seek to next message when stream state is unknown
+     */
+    public final static int MAGIC = 0xE9BEB4D9;
+    public final static byte[] MAGIC_BYTES = ByteBuffer.allocate(4).putInt(MAGIC).array();
+
+    private final MessagePayload payload;
+
+    public NetworkMessage(MessagePayload payload) {
+        this.payload = payload;
+    }
+
+    /**
+     * First 4 bytes of sha512(payload)
+     */
+    private byte[] getChecksum(byte[] bytes) throws NoSuchProviderException, NoSuchAlgorithmException {
+        byte[] d = cryptography().sha512(bytes);
+        return new byte[]{d[0], d[1], d[2], d[3]};
+    }
+
+    /**
+     * The actual data, a message or an object. Not to be confused with objectPayload.
+     */
+    public MessagePayload getPayload() {
+        return payload;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        // magic
+        Encode.int32(MAGIC, out);
+
+        // ASCII string identifying the packet content, NULL padded (non-NULL padding results in packet rejected)
+        String command = payload.getCommand().name().toLowerCase();
+        out.write(command.getBytes("ASCII"));
+        for (int i = command.length(); i < 12; i++) {
+            out.write('\0');
+        }
+
+        byte[] payloadBytes = Encode.bytes(payload);
+
+        // Length of payload in number of bytes. Because of other restrictions, there is no reason why this length would
+        // ever be larger than 1600003 bytes. Some clients include a sanity-check to avoid processing messages which are
+        // larger than this.
+        Encode.int32(payloadBytes.length, out);
+
+        // checksum
+        try {
+            out.write(getChecksum(payloadBytes));
+        } catch (GeneralSecurityException e) {
+            throw new ApplicationException(e);
+        }
+
+        // message payload
+        out.write(payloadBytes);
+    }
+
+    /**
+     * A more efficient implementation of the write method, writing header data to the provided buffer and returning
+     * a new buffer containing the payload.
+     *
+     * @param headerBuffer where the header data is written to (24 bytes)
+     * @return a buffer containing the payload, ready to be read.
+     */
+    public ByteBuffer writeHeaderAndGetPayloadBuffer(ByteBuffer headerBuffer) {
+        return ByteBuffer.wrap(writeHeader(headerBuffer));
+    }
+
+    /**
+     * For improved memory efficiency, you should use {@link #writeHeaderAndGetPayloadBuffer(ByteBuffer)}
+     * and write the header buffer as well as the returned payload buffer into the channel.
+     *
+     * @param buffer where everything gets written to. Needs to be large enough for the whole message
+     *               to be written.
+     */
+    @Override
+    public void write(ByteBuffer buffer) {
+        byte[] payloadBytes = writeHeader(buffer);
+        buffer.put(payloadBytes);
+    }
+
+    private byte[] writeHeader(ByteBuffer out) {
+        // magic
+        Encode.int32(MAGIC, out);
+
+        // ASCII string identifying the packet content, NULL padded (non-NULL padding results in packet rejected)
+        String command = payload.getCommand().name().toLowerCase();
+        try {
+            out.put(command.getBytes("ASCII"));
+        } catch (UnsupportedEncodingException e) {
+            throw new ApplicationException(e);
+        }
+        for (int i = command.length(); i < 12; i++) {
+            out.put((byte) 0);
+        }
+
+        byte[] payloadBytes = Encode.bytes(payload);
+
+        // Length of payload in number of bytes. Because of other restrictions, there is no reason why this length would
+        // ever be larger than 1600003 bytes. Some clients include a sanity-check to avoid processing messages which are
+        // larger than this.
+        Encode.int32(payloadBytes.length, out);
+
+        // checksum
+        try {
+            out.put(getChecksum(payloadBytes));
+        } catch (GeneralSecurityException e) {
+            throw new ApplicationException(e);
+        }
+
+        // message payload
+        return payloadBytes;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/ObjectMessage.java

@@ -0,0 +1,271 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import ch.dissem.bitmessage.entity.payload.ObjectPayload;
+import ch.dissem.bitmessage.entity.payload.ObjectType;
+import ch.dissem.bitmessage.entity.payload.Pubkey;
+import ch.dissem.bitmessage.entity.valueobject.InventoryVector;
+import ch.dissem.bitmessage.entity.valueobject.PrivateKey;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.exception.DecryptionFailedException;
+import ch.dissem.bitmessage.utils.Bytes;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+import java.util.Objects;
+
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * The 'object' command sends an object that is shared throughout the network.
+ */
+public class ObjectMessage implements MessagePayload {
+    private static final long serialVersionUID = 2495752480120659139L;
+
+    private byte[] nonce;
+    private long expiresTime;
+    private long objectType;
+    /**
+     * The object's version
+     */
+    private long version;
+    private long stream;
+
+    private ObjectPayload payload;
+    private byte[] payloadBytes;
+
+    private ObjectMessage(Builder builder) {
+        nonce = builder.nonce;
+        expiresTime = builder.expiresTime;
+        objectType = builder.objectType;
+        version = builder.payload.getVersion();
+        stream = builder.streamNumber > 0 ? builder.streamNumber : builder.payload.getStream();
+        payload = builder.payload;
+    }
+
+    @Override
+    public Command getCommand() {
+        return Command.OBJECT;
+    }
+
+    public byte[] getNonce() {
+        return nonce;
+    }
+
+    public void setNonce(byte[] nonce) {
+        this.nonce = nonce;
+    }
+
+    public long getExpiresTime() {
+        return expiresTime;
+    }
+
+    public long getType() {
+        return objectType;
+    }
+
+    public ObjectPayload getPayload() {
+        return payload;
+    }
+
+    public long getVersion() {
+        return version;
+    }
+
+    public long getStream() {
+        return stream;
+    }
+
+    public InventoryVector getInventoryVector() {
+        return new InventoryVector(
+                Bytes.truncate(cryptography().doubleSha512(nonce, getPayloadBytesWithoutNonce()), 32)
+        );
+    }
+
+    private boolean isEncrypted() {
+        return payload instanceof Encrypted && !((Encrypted) payload).isDecrypted();
+    }
+
+    public boolean isSigned() {
+        return payload.isSigned();
+    }
+
+    private byte[] getBytesToSign() {
+        try {
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+            writeHeaderWithoutNonce(out);
+            payload.writeBytesToSign(out);
+            return out.toByteArray();
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public void sign(PrivateKey key) {
+        if (payload.isSigned()) {
+            payload.setSignature(cryptography().getSignature(getBytesToSign(), key));
+        }
+    }
+
+    public void decrypt(PrivateKey key) throws IOException, DecryptionFailedException {
+        if (payload instanceof Encrypted) {
+            ((Encrypted) payload).decrypt(key.getPrivateEncryptionKey());
+        }
+    }
+
+    public void decrypt(byte[] privateEncryptionKey) throws IOException, DecryptionFailedException {
+        if (payload instanceof Encrypted) {
+            ((Encrypted) payload).decrypt(privateEncryptionKey);
+        }
+    }
+
+    public void encrypt(byte[] publicEncryptionKey) throws IOException {
+        if (payload instanceof Encrypted) {
+            ((Encrypted) payload).encrypt(publicEncryptionKey);
+        }
+    }
+
+    public void encrypt(Pubkey publicKey) {
+        try {
+            if (payload instanceof Encrypted) {
+                ((Encrypted) payload).encrypt(publicKey.getEncryptionKey());
+            }
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public boolean isSignatureValid(Pubkey pubkey) throws IOException {
+        if (isEncrypted()) throw new IllegalStateException("Payload must be decrypted first");
+        return cryptography().isSignatureValid(getBytesToSign(), payload.getSignature(), pubkey);
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        if (nonce == null) {
+            out.write(new byte[8]);
+        } else {
+            out.write(nonce);
+        }
+        out.write(getPayloadBytesWithoutNonce());
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        if (nonce == null) {
+            buffer.put(new byte[8]);
+        } else {
+            buffer.put(nonce);
+        }
+        buffer.put(getPayloadBytesWithoutNonce());
+    }
+
+    private void writeHeaderWithoutNonce(OutputStream out) throws IOException {
+        Encode.int64(expiresTime, out);
+        Encode.int32(objectType, out);
+        Encode.varInt(version, out);
+        Encode.varInt(stream, out);
+    }
+
+    public byte[] getPayloadBytesWithoutNonce() {
+        try {
+            if (payloadBytes == null) {
+                ByteArrayOutputStream out = new ByteArrayOutputStream();
+                writeHeaderWithoutNonce(out);
+                payload.write(out);
+                payloadBytes = out.toByteArray();
+            }
+            return payloadBytes;
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public static final class Builder {
+        private byte[] nonce;
+        private long expiresTime;
+        private long objectType = -1;
+        private long streamNumber;
+        private ObjectPayload payload;
+
+        public Builder nonce(byte[] nonce) {
+            this.nonce = nonce;
+            return this;
+        }
+
+        public Builder expiresTime(long expiresTime) {
+            this.expiresTime = expiresTime;
+            return this;
+        }
+
+        public Builder objectType(long objectType) {
+            this.objectType = objectType;
+            return this;
+        }
+
+        public Builder objectType(ObjectType objectType) {
+            this.objectType = objectType.getNumber();
+            return this;
+        }
+
+        public Builder stream(long streamNumber) {
+            this.streamNumber = streamNumber;
+            return this;
+        }
+
+        public Builder payload(ObjectPayload payload) {
+            this.payload = payload;
+            if (this.objectType == -1)
+                this.objectType = payload.getType().getNumber();
+            return this;
+        }
+
+        public ObjectMessage build() {
+            return new ObjectMessage(this);
+        }
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        ObjectMessage that = (ObjectMessage) o;
+
+        return expiresTime == that.expiresTime &&
+                objectType == that.objectType &&
+                version == that.version &&
+                stream == that.stream &&
+                Objects.equals(payload, that.payload);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = Arrays.hashCode(nonce);
+        result = 31 * result + (int) (expiresTime ^ (expiresTime >>> 32));
+        result = 31 * result + (int) (objectType ^ (objectType >>> 32));
+        result = 31 * result + (int) (version ^ (version >>> 32));
+        result = 31 * result + (int) (stream ^ (stream >>> 32));
+        result = 31 * result + (payload != null ? payload.hashCode() : 0);
+        return result;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/Plaintext.java

@@ -0,0 +1,612 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import ch.dissem.bitmessage.entity.payload.Msg;
+import ch.dissem.bitmessage.entity.payload.Pubkey.Feature;
+import ch.dissem.bitmessage.entity.valueobject.InventoryVector;
+import ch.dissem.bitmessage.entity.valueobject.Label;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.factory.Factory;
+import ch.dissem.bitmessage.utils.*;
+
+import java.io.*;
+import java.nio.ByteBuffer;
+import java.util.*;
+import java.util.Collections;
+
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * The unencrypted message to be sent by 'msg' or 'broadcast'.
+ */
+public class Plaintext implements Streamable {
+    private static final long serialVersionUID = -5325729856394951079L;
+
+    private final Type type;
+    private final BitmessageAddress from;
+    private final long encoding;
+    private final byte[] message;
+    private final byte[] ackData;
+    private ObjectMessage ackMessage;
+    private Object id;
+    private InventoryVector inventoryVector;
+    private BitmessageAddress to;
+    private byte[] signature;
+    private Status status;
+    private Long sent;
+    private Long received;
+
+    private Set<Label> labels;
+    private byte[] initialHash;
+
+    private long ttl;
+    private int retries;
+    private Long nextTry;
+
+    private Plaintext(Builder builder) {
+        id = builder.id;
+        inventoryVector = builder.inventoryVector;
+        type = builder.type;
+        from = builder.from;
+        to = builder.to;
+        encoding = builder.encoding;
+        message = builder.message;
+        ackData = builder.ackData;
+        if (builder.ackMessage != null && builder.ackMessage.length > 0) {
+            ackMessage = Factory.getObjectMessage(
+                3,
+                new ByteArrayInputStream(builder.ackMessage),
+                builder.ackMessage.length);
+        }
+        signature = builder.signature;
+        status = builder.status;
+        sent = builder.sent;
+        received = builder.received;
+        labels = builder.labels;
+        ttl = builder.ttl;
+        retries = builder.retries;
+        nextTry = builder.nextTry;
+    }
+
+    public static Plaintext read(Type type, InputStream in) throws IOException {
+        return readWithoutSignature(type, in)
+            .signature(Decode.varBytes(in))
+            .received(UnixTime.now())
+            .build();
+    }
+
+    public static Plaintext.Builder readWithoutSignature(Type type, InputStream in) throws IOException {
+        long version = Decode.varInt(in);
+        return new Builder(type)
+            .addressVersion(version)
+            .stream(Decode.varInt(in))
+            .behaviorBitfield(Decode.int32(in))
+            .publicSigningKey(Decode.bytes(in, 64))
+            .publicEncryptionKey(Decode.bytes(in, 64))
+            .nonceTrialsPerByte(version >= 3 ? Decode.varInt(in) : 0)
+            .extraBytes(version >= 3 ? Decode.varInt(in) : 0)
+            .destinationRipe(type == Type.MSG ? Decode.bytes(in, 20) : null)
+            .encoding(Decode.varInt(in))
+            .message(Decode.varBytes(in))
+            .ackMessage(type == Type.MSG ? Decode.varBytes(in) : null);
+    }
+
+    public InventoryVector getInventoryVector() {
+        return inventoryVector;
+    }
+
+    public void setInventoryVector(InventoryVector inventoryVector) {
+        this.inventoryVector = inventoryVector;
+    }
+
+    public Type getType() {
+        return type;
+    }
+
+    public byte[] getMessage() {
+        return message;
+    }
+
+    public BitmessageAddress getFrom() {
+        return from;
+    }
+
+    public BitmessageAddress getTo() {
+        return to;
+    }
+
+    public void setTo(BitmessageAddress to) {
+        if (this.to.getVersion() != 0)
+            throw new IllegalStateException("Correct address already set");
+        if (!Arrays.equals(this.to.getRipe(), to.getRipe())) {
+            throw new IllegalArgumentException("RIPEs don't match");
+        }
+        this.to = to;
+    }
+
+    public Set<Label> getLabels() {
+        return labels;
+    }
+
+    public long getStream() {
+        return from.getStream();
+    }
+
+    public byte[] getSignature() {
+        return signature;
+    }
+
+    public void setSignature(byte[] signature) {
+        this.signature = signature;
+    }
+
+    public boolean isUnread() {
+        for (Label label : labels) {
+            if (label.getType() == Label.Type.UNREAD) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    public void write(OutputStream out, boolean includeSignature) throws IOException {
+        Encode.varInt(from.getVersion(), out);
+        Encode.varInt(from.getStream(), out);
+        Encode.int32(from.getPubkey().getBehaviorBitfield(), out);
+        out.write(from.getPubkey().getSigningKey(), 1, 64);
+        out.write(from.getPubkey().getEncryptionKey(), 1, 64);
+        if (from.getVersion() >= 3) {
+            Encode.varInt(from.getPubkey().getNonceTrialsPerByte(), out);
+            Encode.varInt(from.getPubkey().getExtraBytes(), out);
+        }
+        if (type == Type.MSG) {
+            out.write(to.getRipe());
+        }
+        Encode.varInt(encoding, out);
+        Encode.varInt(message.length, out);
+        out.write(message);
+        if (type == Type.MSG) {
+            if (to.has(Feature.DOES_ACK) && getAckMessage() != null) {
+                ByteArrayOutputStream ack = new ByteArrayOutputStream();
+                getAckMessage().write(ack);
+                Encode.varBytes(ack.toByteArray(), out);
+            } else {
+                Encode.varInt(0, out);
+            }
+        }
+        if (includeSignature) {
+            if (signature == null) {
+                Encode.varInt(0, out);
+            } else {
+                Encode.varInt(signature.length, out);
+                out.write(signature);
+            }
+        }
+    }
+
+    public void write(ByteBuffer buffer, boolean includeSignature) {
+        Encode.varInt(from.getVersion(), buffer);
+        Encode.varInt(from.getStream(), buffer);
+        Encode.int32(from.getPubkey().getBehaviorBitfield(), buffer);
+        buffer.put(from.getPubkey().getSigningKey(), 1, 64);
+        buffer.put(from.getPubkey().getEncryptionKey(), 1, 64);
+        if (from.getVersion() >= 3) {
+            Encode.varInt(from.getPubkey().getNonceTrialsPerByte(), buffer);
+            Encode.varInt(from.getPubkey().getExtraBytes(), buffer);
+        }
+        if (type == Type.MSG) {
+            buffer.put(to.getRipe());
+        }
+        Encode.varInt(encoding, buffer);
+        Encode.varInt(message.length, buffer);
+        buffer.put(message);
+        if (type == Type.MSG) {
+            if (to.has(Feature.DOES_ACK) && getAckMessage() != null) {
+                Encode.varBytes(Encode.bytes(getAckMessage()), buffer);
+            } else {
+                Encode.varInt(0, buffer);
+            }
+        }
+        if (includeSignature) {
+            if (signature == null) {
+                Encode.varInt(0, buffer);
+            } else {
+                Encode.varInt(signature.length, buffer);
+                buffer.put(signature);
+            }
+        }
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        write(out, true);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        write(buffer, true);
+    }
+
+    public Object getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        if (this.id != null) throw new IllegalStateException("ID already set");
+        this.id = id;
+    }
+
+    public Long getSent() {
+        return sent;
+    }
+
+    public Long getReceived() {
+        return received;
+    }
+
+    public Status getStatus() {
+        return status;
+    }
+
+    public void setStatus(Status status) {
+        if (status != Status.RECEIVED && sent == null && status != Status.DRAFT) {
+            sent = UnixTime.now();
+        }
+        this.status = status;
+    }
+
+    public long getTTL() {
+        return ttl;
+    }
+
+    public int getRetries() {
+        return retries;
+    }
+
+    public Long getNextTry() {
+        return nextTry;
+    }
+
+    public void updateNextTry() {
+        if (to != null) {
+            if (nextTry == null) {
+                if (sent != null && to.has(Feature.DOES_ACK)) {
+                    nextTry = UnixTime.now(+ttl);
+                    retries++;
+                }
+            } else {
+                nextTry = nextTry + (1 << retries) * ttl;
+                retries++;
+            }
+        }
+    }
+
+    public String getSubject() {
+        Scanner s = new Scanner(new ByteArrayInputStream(message), "UTF-8");
+        String firstLine = s.nextLine();
+        if (encoding == 2) {
+            return firstLine.substring("Subject:".length()).trim();
+        } else if (firstLine.length() > 50) {
+            return firstLine.substring(0, 50).trim() + "...";
+        } else {
+            return firstLine;
+        }
+    }
+
+    public String getText() {
+        try {
+            String text = new String(message, "UTF-8");
+            if (encoding == 2) {
+                return text.substring(text.indexOf("\nBody:") + 6);
+            }
+            return text;
+        } catch (UnsupportedEncodingException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Plaintext plaintext = (Plaintext) o;
+        return Objects.equals(encoding, plaintext.encoding) &&
+            Objects.equals(from, plaintext.from) &&
+            Arrays.equals(message, plaintext.message) &&
+            Objects.equals(getAckMessage(), plaintext.getAckMessage()) &&
+            Arrays.equals(to == null ? null : to.getRipe(), plaintext.to == null ? null : plaintext.to.getRipe()) &&
+            Arrays.equals(signature, plaintext.signature) &&
+            Objects.equals(status, plaintext.status) &&
+            Objects.equals(sent, plaintext.sent) &&
+            Objects.equals(received, plaintext.received) &&
+            Objects.equals(labels, plaintext.labels);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(from, encoding, message, ackData, to, signature, status, sent, received, labels);
+    }
+
+    public void addLabels(Label... labels) {
+        if (labels != null) {
+            Collections.addAll(this.labels, labels);
+        }
+    }
+
+    public void addLabels(Collection<Label> labels) {
+        if (labels != null) {
+            for (Label label : labels) {
+                this.labels.add(label);
+            }
+        }
+    }
+
+    public void removeLabel(Label.Type type) {
+        Iterator<Label> iterator = labels.iterator();
+        while (iterator.hasNext()) {
+            Label label = iterator.next();
+            if (label.getType() == type) {
+                iterator.remove();
+            }
+        }
+    }
+
+    public byte[] getAckData() {
+        return ackData;
+    }
+
+    public ObjectMessage getAckMessage() {
+        if (ackMessage == null) {
+            ackMessage = Factory.createAck(this);
+        }
+        return ackMessage;
+    }
+
+    public void setInitialHash(byte[] initialHash) {
+        this.initialHash = initialHash;
+    }
+
+    public byte[] getInitialHash() {
+        return initialHash;
+    }
+
+    public enum Encoding {
+        IGNORE(0), TRIVIAL(1), SIMPLE(2);
+
+        long code;
+
+        Encoding(long code) {
+            this.code = code;
+        }
+
+        public long getCode() {
+            return code;
+        }
+    }
+
+    public enum Status {
+        DRAFT,
+        // For sent messages
+        PUBKEY_REQUESTED,
+        DOING_PROOF_OF_WORK,
+        SENT,
+        SENT_ACKNOWLEDGED,
+        RECEIVED
+    }
+
+    public enum Type {
+        MSG, BROADCAST
+    }
+
+    public static final class Builder {
+        private Object id;
+        private InventoryVector inventoryVector;
+        private Type type;
+        private BitmessageAddress from;
+        private BitmessageAddress to;
+        private long addressVersion;
+        private long stream;
+        private int behaviorBitfield;
+        private byte[] publicSigningKey;
+        private byte[] publicEncryptionKey;
+        private long nonceTrialsPerByte;
+        private long extraBytes;
+        private byte[] destinationRipe;
+        private long encoding;
+        private byte[] message = new byte[0];
+        private byte[] ackData;
+        private byte[] ackMessage;
+        private byte[] signature;
+        private long sent;
+        private long received;
+        private Status status;
+        private Set<Label> labels = new HashSet<>();
+        private long ttl;
+        private int retries;
+        private Long nextTry;
+
+        public Builder(Type type) {
+            this.type = type;
+        }
+
+        public Builder id(Object id) {
+            this.id = id;
+            return this;
+        }
+
+        public Builder IV(InventoryVector iv) {
+            this.inventoryVector = iv;
+            return this;
+        }
+
+        public Builder from(BitmessageAddress address) {
+            from = address;
+            return this;
+        }
+
+        public Builder to(BitmessageAddress address) {
+            if (type != Type.MSG && to != null)
+                throw new IllegalArgumentException("recipient address only allowed for msg");
+            to = address;
+            return this;
+        }
+
+        private Builder addressVersion(long addressVersion) {
+            this.addressVersion = addressVersion;
+            return this;
+        }
+
+        private Builder stream(long stream) {
+            this.stream = stream;
+            return this;
+        }
+
+        private Builder behaviorBitfield(int behaviorBitfield) {
+            this.behaviorBitfield = behaviorBitfield;
+            return this;
+        }
+
+        private Builder publicSigningKey(byte[] publicSigningKey) {
+            this.publicSigningKey = publicSigningKey;
+            return this;
+        }
+
+        private Builder publicEncryptionKey(byte[] publicEncryptionKey) {
+            this.publicEncryptionKey = publicEncryptionKey;
+            return this;
+        }
+
+        private Builder nonceTrialsPerByte(long nonceTrialsPerByte) {
+            this.nonceTrialsPerByte = nonceTrialsPerByte;
+            return this;
+        }
+
+        private Builder extraBytes(long extraBytes) {
+            this.extraBytes = extraBytes;
+            return this;
+        }
+
+        private Builder destinationRipe(byte[] ripe) {
+            if (type != Type.MSG && ripe != null) throw new IllegalArgumentException("ripe only allowed for msg");
+            this.destinationRipe = ripe;
+            return this;
+        }
+
+        public Builder encoding(Encoding encoding) {
+            this.encoding = encoding.getCode();
+            return this;
+        }
+
+        private Builder encoding(long encoding) {
+            this.encoding = encoding;
+            return this;
+        }
+
+        public Builder message(String subject, String message) {
+            try {
+                this.encoding = Encoding.SIMPLE.getCode();
+                this.message = ("Subject:" + subject + '\n' + "Body:" + message).getBytes("UTF-8");
+            } catch (UnsupportedEncodingException e) {
+                throw new ApplicationException(e);
+            }
+            return this;
+        }
+
+        public Builder message(byte[] message) {
+            this.message = message;
+            return this;
+        }
+
+        public Builder ackMessage(byte[] ack) {
+            if (type != Type.MSG && ack != null) throw new IllegalArgumentException("ackMessage only allowed for msg");
+            this.ackMessage = ack;
+            return this;
+        }
+
+        public Builder ackData(byte[] ackData) {
+            if (type != Type.MSG && ackData != null)
+                throw new IllegalArgumentException("ackMessage only allowed for msg");
+            this.ackData = ackData;
+            return this;
+        }
+
+        public Builder signature(byte[] signature) {
+            this.signature = signature;
+            return this;
+        }
+
+        public Builder sent(long sent) {
+            this.sent = sent;
+            return this;
+        }
+
+        public Builder received(long received) {
+            this.received = received;
+            return this;
+        }
+
+        public Builder status(Status status) {
+            this.status = status;
+            return this;
+        }
+
+        public Builder labels(Collection<Label> labels) {
+            this.labels.addAll(labels);
+            return this;
+        }
+
+        public Builder ttl(long ttl) {
+            this.ttl = ttl;
+            return this;
+        }
+
+        public Builder retries(int retries) {
+            this.retries = retries;
+            return this;
+        }
+
+        public Builder nextTry(Long nextTry) {
+            this.nextTry = nextTry;
+            return this;
+        }
+
+        public Plaintext build() {
+            if (from == null) {
+                from = new BitmessageAddress(Factory.createPubkey(
+                    addressVersion,
+                    stream,
+                    publicSigningKey,
+                    publicEncryptionKey,
+                    nonceTrialsPerByte,
+                    extraBytes,
+                    behaviorBitfield
+                ));
+            }
+            if (to == null && type != Type.BROADCAST && destinationRipe != null) {
+                to = new BitmessageAddress(0, 0, destinationRipe);
+            }
+            if (type == Type.MSG && ackMessage == null && ackData == null) {
+                ackData = cryptography().randomBytes(Msg.ACK_LENGTH);
+            }
+            if (ttl <= 0) {
+                ttl = TTL.msg();
+            }
+            return new Plaintext(this);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/PlaintextHolder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,8 +14,8 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.entity
+package ch.dissem.bitmessage.entity;
 
-interface PlaintextHolder {
-    val plaintext: Plaintext?
+public interface PlaintextHolder {
+    Plaintext getPlaintext();
 }

core/src/main/java/ch/dissem/bitmessage/entity/Streamable.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.Serializable;
+import java.nio.ByteBuffer;
+
+/**
+ * An object that can be written to an {@link OutputStream}
+ */
+public interface Streamable extends Serializable {
+    void write(OutputStream stream) throws IOException;
+
+    void write(ByteBuffer buffer);
+}

core/src/main/java/ch/dissem/bitmessage/entity/VerAck.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,27 +14,30 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.entity
+package ch.dissem.bitmessage.entity;
 
-import java.io.OutputStream
-import java.nio.ByteBuffer
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
 
 /**
  * The 'verack' command answers a 'version' command, accepting the other node's version.
  */
-class VerAck : MessagePayload {
+public class VerAck implements MessagePayload {
+    private static final long serialVersionUID = -4302074845199181687L;
 
-    override val command: MessagePayload.Command = MessagePayload.Command.VERACK
+    @Override
+    public Command getCommand() {
+        return Command.VERACK;
+    }
 
+    @Override
+    public void write(OutputStream stream) throws IOException {
         // 'verack' doesn't have any payload, so there is nothing to write
-    override fun writer(): StreamableWriter = EmptyWriter
-
-    internal object EmptyWriter : StreamableWriter {
-        override fun write(out: OutputStream) = Unit
-        override fun write(buffer: ByteBuffer) = Unit
     }
 
-    companion object {
-        private val serialVersionUID = -4302074845199181687L
+    @Override
+    public void write(ByteBuffer buffer) {
+        // 'verack' doesn't have any payload, so there is nothing to write
     }
 }

core/src/main/java/ch/dissem/bitmessage/entity/Version.java

@@ -0,0 +1,214 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity;
+
+import ch.dissem.bitmessage.BitmessageContext;
+import ch.dissem.bitmessage.entity.valueobject.NetworkAddress;
+import ch.dissem.bitmessage.utils.Encode;
+import ch.dissem.bitmessage.utils.UnixTime;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+
+/**
+ * The 'version' command advertises this node's latest supported protocol version upon initiation.
+ */
+public class Version implements MessagePayload {
+    private static final long serialVersionUID = 7219240857343176567L;
+
+    /**
+     * Identifies protocol version being used by the node. Should equal 3. Nodes should disconnect if the remote node's
+     * version is lower but continue with the connection if it is higher.
+     */
+    private final int version;
+
+    /**
+     * bitfield of features to be enabled for this connection
+     */
+    private final long services;
+
+    /**
+     * standard UNIX timestamp in seconds
+     */
+    private final long timestamp;
+
+    /**
+     * The network address of the node receiving this message (not including the time or stream number)
+     */
+    private final NetworkAddress addrRecv;
+
+    /**
+     * The network address of the node emitting this message (not including the time or stream number and the ip itself
+     * is ignored by the receiver)
+     */
+    private final NetworkAddress addrFrom;
+
+    /**
+     * Random nonce used to detect connections to self.
+     */
+    private final long nonce;
+
+    /**
+     * User Agent (0x00 if string is 0 bytes long). Sending nodes must not include a user_agent longer than 5000 bytes.
+     */
+    private final String userAgent;
+
+    /**
+     * The stream numbers that the emitting node is interested in. Sending nodes must not include more than 160000
+     * stream numbers.
+     */
+    private final long[] streams;
+
+    private Version(Builder builder) {
+        version = builder.version;
+        services = builder.services;
+        timestamp = builder.timestamp;
+        addrRecv = builder.addrRecv;
+        addrFrom = builder.addrFrom;
+        nonce = builder.nonce;
+        userAgent = builder.userAgent;
+        streams = builder.streamNumbers;
+    }
+
+    public int getVersion() {
+        return version;
+    }
+
+    public long getServices() {
+        return services;
+    }
+
+    public long getTimestamp() {
+        return timestamp;
+    }
+
+    public NetworkAddress getAddrRecv() {
+        return addrRecv;
+    }
+
+    public NetworkAddress getAddrFrom() {
+        return addrFrom;
+    }
+
+    public long getNonce() {
+        return nonce;
+    }
+
+    public String getUserAgent() {
+        return userAgent;
+    }
+
+    public long[] getStreams() {
+        return streams;
+    }
+
+    @Override
+    public Command getCommand() {
+        return Command.VERSION;
+    }
+
+    @Override
+    public void write(OutputStream stream) throws IOException {
+        Encode.int32(version, stream);
+        Encode.int64(services, stream);
+        Encode.int64(timestamp, stream);
+        addrRecv.write(stream, true);
+        addrFrom.write(stream, true);
+        Encode.int64(nonce, stream);
+        Encode.varString(userAgent, stream);
+        Encode.varIntList(streams, stream);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        Encode.int32(version, buffer);
+        Encode.int64(services, buffer);
+        Encode.int64(timestamp, buffer);
+        addrRecv.write(buffer, true);
+        addrFrom.write(buffer, true);
+        Encode.int64(nonce, buffer);
+        Encode.varString(userAgent, buffer);
+        Encode.varIntList(streams, buffer);
+    }
+
+
+    public static final class Builder {
+        private int version;
+        private long services;
+        private long timestamp;
+        private NetworkAddress addrRecv;
+        private NetworkAddress addrFrom;
+        private long nonce;
+        private String userAgent;
+        private long[] streamNumbers;
+
+        public Builder defaults(long clientNonce) {
+            version = BitmessageContext.CURRENT_VERSION;
+            services = 1;
+            timestamp = UnixTime.now();
+            userAgent = "/Jabit:0.0.1/";
+            streamNumbers = new long[]{1};
+            nonce = clientNonce;
+            return this;
+        }
+
+        public Builder version(int version) {
+            this.version = version;
+            return this;
+        }
+
+        public Builder services(long services) {
+            this.services = services;
+            return this;
+        }
+
+        public Builder timestamp(long timestamp) {
+            this.timestamp = timestamp;
+            return this;
+        }
+
+        public Builder addrRecv(NetworkAddress addrRecv) {
+            this.addrRecv = addrRecv;
+            return this;
+        }
+
+        public Builder addrFrom(NetworkAddress addrFrom) {
+            this.addrFrom = addrFrom;
+            return this;
+        }
+
+        public Builder nonce(long nonce) {
+            this.nonce = nonce;
+            return this;
+        }
+
+        public Builder userAgent(String userAgent) {
+            this.userAgent = userAgent;
+            return this;
+        }
+
+        public Builder streams(long... streamNumbers) {
+            this.streamNumbers = streamNumbers;
+            return this;
+        }
+
+        public Version build() {
+            return new Version(this);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/Broadcast.java

@@ -0,0 +1,114 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.Encrypted;
+import ch.dissem.bitmessage.entity.Plaintext;
+import ch.dissem.bitmessage.entity.PlaintextHolder;
+import ch.dissem.bitmessage.exception.DecryptionFailedException;
+
+import java.io.IOException;
+import java.util.Objects;
+
+import static ch.dissem.bitmessage.entity.Plaintext.Type.BROADCAST;
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * Users who are subscribed to the sending address will see the message appear in their inbox.
+ * Broadcasts are version 4 or 5.
+ */
+public abstract class Broadcast extends ObjectPayload implements Encrypted, PlaintextHolder {
+    private static final long serialVersionUID = 4064521827582239069L;
+
+    protected final long stream;
+    protected CryptoBox encrypted;
+    protected Plaintext plaintext;
+
+    protected Broadcast(long version, long stream, CryptoBox encrypted, Plaintext plaintext) {
+        super(version);
+        this.stream = stream;
+        this.encrypted = encrypted;
+        this.plaintext = plaintext;
+    }
+
+    public static long getVersion(BitmessageAddress address) {
+        return address.getVersion() < 4 ? 4 : 5;
+    }
+
+    @Override
+    public boolean isSigned() {
+        return true;
+    }
+
+    @Override
+    public byte[] getSignature() {
+        return plaintext.getSignature();
+    }
+
+    @Override
+    public void setSignature(byte[] signature) {
+        plaintext.setSignature(signature);
+    }
+
+    @Override
+    public long getStream() {
+        return stream;
+    }
+
+    @Override
+    public Plaintext getPlaintext() {
+        return plaintext;
+    }
+
+    @Override
+    public void encrypt(byte[] publicKey) throws IOException {
+        this.encrypted = new CryptoBox(plaintext, publicKey);
+    }
+
+    public void encrypt() throws IOException {
+        encrypt(cryptography().createPublicKey(plaintext.getFrom().getPublicDecryptionKey()));
+    }
+
+    @Override
+    public void decrypt(byte[] privateKey) throws IOException, DecryptionFailedException {
+        plaintext = Plaintext.read(BROADCAST, encrypted.decrypt(privateKey));
+    }
+
+    public void decrypt(BitmessageAddress address) throws IOException, DecryptionFailedException {
+        decrypt(address.getPublicDecryptionKey());
+    }
+
+    @Override
+    public boolean isDecrypted() {
+        return plaintext != null;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Broadcast broadcast = (Broadcast) o;
+        return stream == broadcast.stream &&
+                (Objects.equals(encrypted, broadcast.encrypted) || Objects.equals(plaintext, broadcast.plaintext));
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(stream);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/CryptoBox.java

@@ -0,0 +1,214 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.entity.Streamable;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.exception.DecryptionFailedException;
+import ch.dissem.bitmessage.utils.*;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.*;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
+import static ch.dissem.bitmessage.entity.valueobject.PrivateKey.PRIVATE_KEY_SIZE;
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+
+public class CryptoBox implements Streamable {
+    private static final long serialVersionUID = 7217659539975573852L;
+    private static final Logger LOG = LoggerFactory.getLogger(CryptoBox.class);
+
+    private final byte[] initializationVector;
+    private final int curveType;
+    private final byte[] R;
+    private final byte[] mac;
+    private byte[] encrypted;
+
+
+    public CryptoBox(Streamable data, byte[] K) throws IOException {
+        this(Encode.bytes(data), K);
+    }
+
+    public CryptoBox(byte[] data, byte[] K) throws IOException {
+        curveType = 0x02CA;
+
+        // 1. The destination public key is called K.
+        // 2. Generate 16 random bytes using a secure random number generator. Call them IV.
+        initializationVector = cryptography().randomBytes(16);
+
+        // 3. Generate a new random EC key pair with private key called r and public key called R.
+        byte[] r = cryptography().randomBytes(PRIVATE_KEY_SIZE);
+        R = cryptography().createPublicKey(r);
+        // 4. Do an EC point multiply with public key K and private key r. This gives you public key P.
+        byte[] P = cryptography().multiply(K, r);
+        byte[] X = Points.getX(P);
+        // 5. Use the X component of public key P and calculate the SHA512 hash H.
+        byte[] H = cryptography().sha512(X);
+        // 6. The first 32 bytes of H are called key_e and the last 32 bytes are called key_m.
+        byte[] key_e = Arrays.copyOfRange(H, 0, 32);
+        byte[] key_m = Arrays.copyOfRange(H, 32, 64);
+        // 7. Pad the input text to a multiple of 16 bytes, in accordance to PKCS7.
+        // 8. Encrypt the data with AES-256-CBC, using IV as initialization vector, key_e as encryption key and the padded input text as payload. Call the output cipher text.
+        encrypted = cryptography().crypt(true, data, key_e, initializationVector);
+        // 9. Calculate a 32 byte MAC with HMACSHA256, using key_m as salt and IV + R + cipher text as data. Call the output MAC.
+        mac = calculateMac(key_m);
+
+        // The resulting data is: IV + R + cipher text + MAC
+    }
+
+    private CryptoBox(Builder builder) {
+        initializationVector = builder.initializationVector;
+        curveType = builder.curveType;
+        R = cryptography().createPoint(builder.xComponent, builder.yComponent);
+        encrypted = builder.encrypted;
+        mac = builder.mac;
+    }
+
+    public static CryptoBox read(InputStream stream, int length) throws IOException {
+        AccessCounter counter = new AccessCounter();
+        return new Builder()
+                .IV(Decode.bytes(stream, 16, counter))
+                .curveType(Decode.uint16(stream, counter))
+                .X(Decode.shortVarBytes(stream, counter))
+                .Y(Decode.shortVarBytes(stream, counter))
+                .encrypted(Decode.bytes(stream, length - counter.length() - 32))
+                .MAC(Decode.bytes(stream, 32))
+                .build();
+    }
+
+    /**
+     * @param k a private key, typically should be 32 bytes long
+     * @return an InputStream yielding the decrypted data
+     * @throws DecryptionFailedException if the payload can't be decrypted using this private key
+     * @see <a href='https://bitmessage.org/wiki/Encryption#Decryption'>https://bitmessage.org/wiki/Encryption#Decryption</a>
+     */
+    public InputStream decrypt(byte[] k) throws DecryptionFailedException {
+        // 1. The private key used to decrypt is called k.
+        // 2. Do an EC point multiply with private key k and public key R. This gives you public key P.
+        byte[] P = cryptography().multiply(R, k);
+        // 3. Use the X component of public key P and calculate the SHA512 hash H.
+        byte[] H = cryptography().sha512(Arrays.copyOfRange(P, 1, 33));
+        // 4. The first 32 bytes of H are called key_e and the last 32 bytes are called key_m.
+        byte[] key_e = Arrays.copyOfRange(H, 0, 32);
+        byte[] key_m = Arrays.copyOfRange(H, 32, 64);
+
+        // 5. Calculate MAC' with HMACSHA256, using key_m as salt and IV + R + cipher text as data.
+        // 6. Compare MAC with MAC'. If not equal, decryption will fail.
+        if (!Arrays.equals(mac, calculateMac(key_m))) {
+            throw new DecryptionFailedException();
+        }
+
+        // 7. Decrypt the cipher text with AES-256-CBC, using IV as initialization vector, key_e as decryption key
+        //    and the cipher text as payload. The output is the padded input text.
+        return new ByteArrayInputStream(cryptography().crypt(false, encrypted, key_e, initializationVector));
+    }
+
+    private byte[] calculateMac(byte[] key_m) {
+        try {
+            ByteArrayOutputStream macData = new ByteArrayOutputStream();
+            writeWithoutMAC(macData);
+            return cryptography().mac(key_m, macData.toByteArray());
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    private void writeWithoutMAC(OutputStream out) throws IOException {
+        out.write(initializationVector);
+        Encode.int16(curveType, out);
+        writeCoordinateComponent(out, Points.getX(R));
+        writeCoordinateComponent(out, Points.getY(R));
+        out.write(encrypted);
+    }
+
+    private void writeCoordinateComponent(OutputStream out, byte[] x) throws IOException {
+        int offset = Bytes.numberOfLeadingZeros(x);
+        int length = x.length - offset;
+        Encode.int16(length, out);
+        out.write(x, offset, length);
+    }
+
+    private void writeCoordinateComponent(ByteBuffer buffer, byte[] x) {
+        int offset = Bytes.numberOfLeadingZeros(x);
+        int length = x.length - offset;
+        Encode.int16(length, buffer);
+        buffer.put(x, offset, length);
+    }
+
+    @Override
+    public void write(OutputStream stream) throws IOException {
+        writeWithoutMAC(stream);
+        stream.write(mac);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        buffer.put(initializationVector);
+        Encode.int16(curveType, buffer);
+        writeCoordinateComponent(buffer, Points.getX(R));
+        writeCoordinateComponent(buffer, Points.getY(R));
+        buffer.put(encrypted);
+        buffer.put(mac);
+    }
+
+    public static final class Builder {
+        private byte[] initializationVector;
+        private int curveType;
+        private byte[] xComponent;
+        private byte[] yComponent;
+        private byte[] encrypted;
+        private byte[] mac;
+
+        public Builder IV(byte[] initializationVector) {
+            this.initializationVector = initializationVector;
+            return this;
+        }
+
+        public Builder curveType(int curveType) {
+            if (curveType != 0x2CA) LOG.trace("Unexpected curve type " + curveType);
+            this.curveType = curveType;
+            return this;
+        }
+
+        public Builder X(byte[] xComponent) {
+            this.xComponent = xComponent;
+            return this;
+        }
+
+        public Builder Y(byte[] yComponent) {
+            this.yComponent = yComponent;
+            return this;
+        }
+
+        private Builder encrypted(byte[] encrypted) {
+            this.encrypted = encrypted;
+            return this;
+        }
+
+        public Builder MAC(byte[] mac) {
+            this.mac = mac;
+            return this;
+        }
+
+        public CryptoBox build() {
+            return new CryptoBox(this);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/GenericPayload.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.utils.Decode;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
+/**
+ * In cases we don't know what to do with an object, we just store its bytes and send it again - we don't really
+ * have to know what it is.
+ */
+public class GenericPayload extends ObjectPayload {
+    private static final long serialVersionUID = -912314085064185940L;
+
+    private long stream;
+    private byte[] data;
+
+    public GenericPayload(long version, long stream, byte[] data) {
+        super(version);
+        this.stream = stream;
+        this.data = data;
+    }
+
+    public static GenericPayload read(long version, long stream, InputStream is, int length) throws IOException {
+        return new GenericPayload(version, stream, Decode.bytes(is, length));
+    }
+
+    @Override
+    public ObjectType getType() {
+        return null;
+    }
+
+    @Override
+    public long getStream() {
+        return stream;
+    }
+
+    public byte[] getData() {
+        return data;
+    }
+
+    @Override
+    public void write(OutputStream stream) throws IOException {
+        stream.write(data);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        buffer.put(data);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        GenericPayload that = (GenericPayload) o;
+
+        if (stream != that.stream) return false;
+        return Arrays.equals(data, that.data);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = (int) (stream ^ (stream >>> 32));
+        result = 31 * result + Arrays.hashCode(data);
+        return result;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/GetPubkey.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.utils.Decode;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+
+/**
+ * Request for a public key.
+ */
+public class GetPubkey extends ObjectPayload {
+    private static final long serialVersionUID = -3634516646972610180L;
+
+    private long stream;
+    private byte[] ripeTag;
+
+    public GetPubkey(BitmessageAddress address) {
+        super(address.getVersion());
+        this.stream = address.getStream();
+        if (address.getVersion() < 4)
+            this.ripeTag = address.getRipe();
+        else
+            this.ripeTag = address.getTag();
+    }
+
+    private GetPubkey(long version, long stream, byte[] ripeOrTag) {
+        super(version);
+        this.stream = stream;
+        this.ripeTag = ripeOrTag;
+    }
+
+    public static GetPubkey read(InputStream is, long stream, int length, long version) throws IOException {
+        return new GetPubkey(version, stream, Decode.bytes(is, length));
+    }
+
+    /**
+     * @return an array of bytes that represent either the ripe, or the tag of an address, depending on the
+     * address version.
+     */
+    public byte[] getRipeTag() {
+        return ripeTag;
+    }
+
+    @Override
+    public ObjectType getType() {
+        return ObjectType.GET_PUBKEY;
+    }
+
+    @Override
+    public long getStream() {
+        return stream;
+    }
+
+    @Override
+    public void write(OutputStream stream) throws IOException {
+        stream.write(ripeTag);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        buffer.put(ripeTag);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/Msg.java

@@ -0,0 +1,135 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.entity.Encrypted;
+import ch.dissem.bitmessage.entity.Plaintext;
+import ch.dissem.bitmessage.entity.PlaintextHolder;
+import ch.dissem.bitmessage.exception.DecryptionFailedException;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.util.Objects;
+
+import static ch.dissem.bitmessage.entity.Plaintext.Type.MSG;
+
+/**
+ * Used for person-to-person messages.
+ */
+public class Msg extends ObjectPayload implements Encrypted, PlaintextHolder {
+    private static final long serialVersionUID = 4327495048296365733L;
+    public static final int ACK_LENGTH = 32;
+
+    private long stream;
+    private CryptoBox encrypted;
+    private Plaintext plaintext;
+
+    private Msg(long stream, CryptoBox encrypted) {
+        super(1);
+        this.stream = stream;
+        this.encrypted = encrypted;
+    }
+
+    public Msg(Plaintext plaintext) {
+        super(1);
+        this.stream = plaintext.getStream();
+        this.plaintext = plaintext;
+    }
+
+    public static Msg read(InputStream in, long stream, int length) throws IOException {
+        return new Msg(stream, CryptoBox.read(in, length));
+    }
+
+    @Override
+    public Plaintext getPlaintext() {
+        return plaintext;
+    }
+
+    @Override
+    public ObjectType getType() {
+        return ObjectType.MSG;
+    }
+
+    @Override
+    public long getStream() {
+        return stream;
+    }
+
+    @Override
+    public boolean isSigned() {
+        return true;
+    }
+
+    @Override
+    public void writeBytesToSign(OutputStream out) throws IOException {
+        plaintext.write(out, false);
+    }
+
+    @Override
+    public byte[] getSignature() {
+        return plaintext.getSignature();
+    }
+
+    @Override
+    public void setSignature(byte[] signature) {
+        plaintext.setSignature(signature);
+    }
+
+    @Override
+    public void encrypt(byte[] publicKey) throws IOException {
+        this.encrypted = new CryptoBox(plaintext, publicKey);
+    }
+
+    @Override
+    public void decrypt(byte[] privateKey) throws IOException, DecryptionFailedException {
+        plaintext = Plaintext.read(MSG, encrypted.decrypt(privateKey));
+    }
+
+    @Override
+    public boolean isDecrypted() {
+        return plaintext != null;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        if (encrypted == null) throw new IllegalStateException("Msg must be signed and encrypted before writing it.");
+        encrypted.write(out);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        if (encrypted == null) throw new IllegalStateException("Msg must be signed and encrypted before writing it.");
+        encrypted.write(buffer);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        if (!super.equals(o)) return false;
+        Msg msg = (Msg) o;
+        return stream == msg.stream &&
+                (Objects.equals(encrypted, msg.encrypted) || Objects.equals(plaintext, msg.plaintext));
+    }
+
+    @Override
+    public int hashCode() {
+        return (int) stream;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/ObjectPayload.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.entity.Streamable;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * The payload of an 'object' command. This is shared by the network.
+ */
+public abstract class ObjectPayload implements Streamable {
+    private static final long serialVersionUID = -5034977402902364482L;
+
+    private final long version;
+
+    protected ObjectPayload(long version) {
+        this.version = version;
+    }
+
+
+    public abstract ObjectType getType();
+
+    public abstract long getStream();
+
+    public long getVersion() {
+        return version;
+    }
+
+    public boolean isSigned() {
+        return false;
+    }
+
+    public void writeBytesToSign(OutputStream out) throws IOException {
+        // nothing to do
+    }
+
+    /**
+     * @return the ECDSA signature which, as of protocol v3, covers the object header starting with the time,
+     * appended with the data described in this table down to the extra_bytes. Therefore, this must
+     * be checked and set in the {@link ObjectMessage} object.
+     */
+    public byte[] getSignature() {
+        return null;
+    }
+
+    public void setSignature(byte[] signature) {
+        // nothing to do
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/ObjectType.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,20 +14,31 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.entity.payload
+package ch.dissem.bitmessage.entity.payload;
 
 /**
  * Known types for 'object' messages. Must not be used where an unknown type must be resent.
  */
-enum class ObjectType constructor(val number: Long) {
+public enum ObjectType {
     GET_PUBKEY(0),
     PUBKEY(1),
     MSG(2),
     BROADCAST(3);
 
-    companion object {
-        @JvmStatic fun fromNumber(number: Long): ObjectType? {
-            return values().firstOrNull { it.number == number }
-        }
+    int number;
+
+    ObjectType(int number) {
+        this.number = number;
+    }
+
+    public static ObjectType fromNumber(long number) {
+        for (ObjectType type : values()) {
+            if (type.number == number) return type;
+        }
+        return null;
+    }
+
+    public long getNumber() {
+        return number;
     }
 }

core/src/main/java/ch/dissem/bitmessage/entity/payload/Pubkey.java

@@ -0,0 +1,121 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * Public keys for signing and encryption, the answer to a 'getpubkey' request.
+ */
+public abstract class Pubkey extends ObjectPayload {
+    private static final long serialVersionUID = -6634533361454999619L;
+
+    public final static long LATEST_VERSION = 4;
+
+    protected Pubkey(long version) {
+        super(version);
+    }
+
+    public static byte[] getRipe(byte[] publicSigningKey, byte[] publicEncryptionKey) {
+        return cryptography().ripemd160(cryptography().sha512(publicSigningKey, publicEncryptionKey));
+    }
+
+    public abstract byte[] getSigningKey();
+
+    public abstract byte[] getEncryptionKey();
+
+    public abstract int getBehaviorBitfield();
+
+    public byte[] getRipe() {
+        return cryptography().ripemd160(cryptography().sha512(getSigningKey(), getEncryptionKey()));
+    }
+
+    public long getNonceTrialsPerByte() {
+        return 0;
+    }
+
+    public long getExtraBytes() {
+        return 0;
+    }
+
+    public void writeUnencrypted(OutputStream out) throws IOException {
+        write(out);
+    }
+
+    public void writeUnencrypted(ByteBuffer buffer){
+        write(buffer);
+    }
+
+    protected byte[] add0x04(byte[] key) {
+        if (key.length == 65) return key;
+        byte[] result = new byte[65];
+        result[0] = 4;
+        System.arraycopy(key, 0, result, 1, 64);
+        return result;
+    }
+
+    /**
+     * Bits 0 through 29 are yet undefined
+     */
+    public enum Feature {
+        /**
+         * Receiving node expects that the RIPE hash encoded in their address preceedes the encrypted message data of msg
+         * messages bound for them.
+         */
+        INCLUDE_DESTINATION(30),
+        /**
+         * If true, the receiving node does send acknowledgements (rather than dropping them).
+         */
+        DOES_ACK(31);
+
+        private int bit;
+
+        Feature(int bitNumber) {
+            // The Bitmessage Protocol Specification starts counting at the most significant bit,
+            // thus the slightly awkward calculation.
+            // https://bitmessage.org/wiki/Protocol_specification#Pubkey_bitfield_features
+            this.bit = 1 << (31 - bitNumber);
+        }
+
+        public static int bitfield(Feature... features) {
+            int bits = 0;
+            for (Feature feature : features) {
+                bits |= feature.bit;
+            }
+            return bits;
+        }
+
+        public static Feature[] features(int bitfield) {
+            ArrayList<Feature> features = new ArrayList<>(Feature.values().length);
+            for (Feature feature : Feature.values()) {
+                if ((bitfield & feature.bit) != 0) {
+                    features.add(feature);
+                }
+            }
+            return features.toArray(new Feature[features.size()]);
+        }
+
+        public boolean isActive(int bitfield) {
+            return (bitfield & bit) != 0;
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/V2Pubkey.java

@@ -0,0 +1,133 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.utils.Decode;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+
+/**
+ * A version 2 public key.
+ */
+public class V2Pubkey extends Pubkey {
+    private static final long serialVersionUID = -257598690676510460L;
+
+    protected long stream;
+    protected int behaviorBitfield;
+    protected byte[] publicSigningKey; // 64 Bytes
+    protected byte[] publicEncryptionKey; // 64 Bytes
+
+    protected V2Pubkey(long version) {
+        super(version);
+    }
+
+    private V2Pubkey(long version, Builder builder) {
+        super(version);
+        stream = builder.streamNumber;
+        behaviorBitfield = builder.behaviorBitfield;
+        publicSigningKey = add0x04(builder.publicSigningKey);
+        publicEncryptionKey = add0x04(builder.publicEncryptionKey);
+    }
+
+    public static V2Pubkey read(InputStream is, long stream) throws IOException {
+        return new V2Pubkey.Builder()
+                .stream(stream)
+                .behaviorBitfield((int) Decode.uint32(is))
+                .publicSigningKey(Decode.bytes(is, 64))
+                .publicEncryptionKey(Decode.bytes(is, 64))
+                .build();
+    }
+
+    @Override
+    public long getVersion() {
+        return 2;
+    }
+
+    @Override
+    public ObjectType getType() {
+        return ObjectType.PUBKEY;
+    }
+
+    @Override
+    public long getStream() {
+        return stream;
+    }
+
+    @Override
+    public byte[] getSigningKey() {
+        return publicSigningKey;
+    }
+
+    @Override
+    public byte[] getEncryptionKey() {
+        return publicEncryptionKey;
+    }
+
+    @Override
+    public int getBehaviorBitfield() {
+        return behaviorBitfield;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        Encode.int32(behaviorBitfield, out);
+        out.write(publicSigningKey, 1, 64);
+        out.write(publicEncryptionKey, 1, 64);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        Encode.int32(behaviorBitfield, buffer);
+        buffer.put(publicSigningKey, 1, 64);
+        buffer.put(publicEncryptionKey, 1, 64);
+    }
+
+    public static class Builder {
+        private long streamNumber;
+        private int behaviorBitfield;
+        private byte[] publicSigningKey;
+        private byte[] publicEncryptionKey;
+
+        public Builder stream(long streamNumber) {
+            this.streamNumber = streamNumber;
+            return this;
+        }
+
+        public Builder behaviorBitfield(int behaviorBitfield) {
+            this.behaviorBitfield = behaviorBitfield;
+            return this;
+        }
+
+        public Builder publicSigningKey(byte[] publicSigningKey) {
+            this.publicSigningKey = publicSigningKey;
+            return this;
+        }
+
+        public Builder publicEncryptionKey(byte[] publicEncryptionKey) {
+            this.publicEncryptionKey = publicEncryptionKey;
+            return this;
+        }
+
+        public V2Pubkey build() {
+            return new V2Pubkey(2, this);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/V3Pubkey.java

@@ -0,0 +1,167 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.utils.Decode;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Arrays;
+import java.util.Objects;
+
+/**
+ * A version 3 public key.
+ */
+public class V3Pubkey extends V2Pubkey {
+    private static final long serialVersionUID = 6958853116648528319L;
+
+    long nonceTrialsPerByte;
+    long extraBytes;
+    byte[] signature;
+
+    protected V3Pubkey(long version, Builder builder) {
+        super(version);
+        stream = builder.streamNumber;
+        behaviorBitfield = builder.behaviorBitfield;
+        publicSigningKey = add0x04(builder.publicSigningKey);
+        publicEncryptionKey = add0x04(builder.publicEncryptionKey);
+        nonceTrialsPerByte = builder.nonceTrialsPerByte;
+        extraBytes = builder.extraBytes;
+        signature = builder.signature;
+    }
+
+    public static V3Pubkey read(InputStream is, long stream) throws IOException {
+        return new V3Pubkey.Builder()
+                .stream(stream)
+                .behaviorBitfield(Decode.int32(is))
+                .publicSigningKey(Decode.bytes(is, 64))
+                .publicEncryptionKey(Decode.bytes(is, 64))
+                .nonceTrialsPerByte(Decode.varInt(is))
+                .extraBytes(Decode.varInt(is))
+                .signature(Decode.varBytes(is))
+                .build();
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        writeBytesToSign(out);
+        Encode.varInt(signature.length, out);
+        out.write(signature);
+    }
+
+    @Override
+    public long getVersion() {
+        return 3;
+    }
+
+    public long getNonceTrialsPerByte() {
+        return nonceTrialsPerByte;
+    }
+
+    public long getExtraBytes() {
+        return extraBytes;
+    }
+
+    public boolean isSigned() {
+        return true;
+    }
+
+    public void writeBytesToSign(OutputStream out) throws IOException {
+        super.write(out);
+        Encode.varInt(nonceTrialsPerByte, out);
+        Encode.varInt(extraBytes, out);
+    }
+
+    @Override
+    public byte[] getSignature() {
+        return signature;
+    }
+
+    @Override
+    public void setSignature(byte[] signature) {
+        this.signature = signature;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        V3Pubkey pubkey = (V3Pubkey) o;
+        return Objects.equals(nonceTrialsPerByte, pubkey.nonceTrialsPerByte) &&
+                Objects.equals(extraBytes, pubkey.extraBytes) &&
+                stream == pubkey.stream &&
+                behaviorBitfield == pubkey.behaviorBitfield &&
+                Arrays.equals(publicSigningKey, pubkey.publicSigningKey) &&
+                Arrays.equals(publicEncryptionKey, pubkey.publicEncryptionKey);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(nonceTrialsPerByte, extraBytes);
+    }
+
+    public static class Builder {
+        private long streamNumber;
+        private int behaviorBitfield;
+        private byte[] publicSigningKey;
+        private byte[] publicEncryptionKey;
+        private long nonceTrialsPerByte;
+        private long extraBytes;
+        private byte[] signature = new byte[0];
+
+        public Builder stream(long streamNumber) {
+            this.streamNumber = streamNumber;
+            return this;
+        }
+
+        public Builder behaviorBitfield(int behaviorBitfield) {
+            this.behaviorBitfield = behaviorBitfield;
+            return this;
+        }
+
+        public Builder publicSigningKey(byte[] publicSigningKey) {
+            this.publicSigningKey = publicSigningKey;
+            return this;
+        }
+
+        public Builder publicEncryptionKey(byte[] publicEncryptionKey) {
+            this.publicEncryptionKey = publicEncryptionKey;
+            return this;
+        }
+
+        public Builder nonceTrialsPerByte(long nonceTrialsPerByte) {
+            this.nonceTrialsPerByte = nonceTrialsPerByte;
+            return this;
+        }
+
+        public Builder extraBytes(long extraBytes) {
+            this.extraBytes = extraBytes;
+            return this;
+        }
+
+        public Builder signature(byte[] signature) {
+            this.signature = signature;
+            return this;
+        }
+
+        public V3Pubkey build() {
+            return new V3Pubkey(3, this);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/V4Broadcast.java

@@ -0,0 +1,67 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.Plaintext;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+
+/**
+ * Users who are subscribed to the sending address will see the message appear in their inbox.
+ * Broadcasts are version 4 or 5.
+ */
+public class V4Broadcast extends Broadcast {
+    private static final long serialVersionUID = 195663108282762711L;
+
+    protected V4Broadcast(long version, long stream, CryptoBox encrypted, Plaintext plaintext) {
+        super(version, stream, encrypted, plaintext);
+    }
+
+    public V4Broadcast(BitmessageAddress senderAddress, Plaintext plaintext) {
+        super(4, senderAddress.getStream(), null, plaintext);
+        if (senderAddress.getVersion() >= 4)
+            throw new IllegalArgumentException("Address version 3 or older expected, but was " + senderAddress.getVersion());
+    }
+
+    public static V4Broadcast read(InputStream in, long stream, int length) throws IOException {
+        return new V4Broadcast(4, stream, CryptoBox.read(in, length), null);
+    }
+
+    @Override
+    public ObjectType getType() {
+        return ObjectType.BROADCAST;
+    }
+
+    @Override
+    public void writeBytesToSign(OutputStream out) throws IOException {
+        plaintext.write(out, false);
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        encrypted.write(out);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        encrypted.write(buffer);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/V4Pubkey.java

@@ -0,0 +1,191 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.Encrypted;
+import ch.dissem.bitmessage.exception.DecryptionFailedException;
+import ch.dissem.bitmessage.utils.Decode;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
+/**
+ * A version 4 public key. When version 4 pubkeys are created, most of the data in the pubkey is encrypted. This is
+ * done in such a way that only someone who has the Bitmessage address which corresponds to a pubkey can decrypt and
+ * use that pubkey. This prevents people from gathering pubkeys sent around the network and using the data from them
+ * to create messages to be used in spam or in flooding attacks.
+ */
+public class V4Pubkey extends Pubkey implements Encrypted {
+    private static final long serialVersionUID = 1556710353694033093L;
+
+    private long stream;
+    private byte[] tag;
+    private CryptoBox encrypted;
+    private V3Pubkey decrypted;
+
+    private V4Pubkey(long stream, byte[] tag, CryptoBox encrypted) {
+        super(4);
+        this.stream = stream;
+        this.tag = tag;
+        this.encrypted = encrypted;
+    }
+
+    public V4Pubkey(V3Pubkey decrypted) {
+        super(4);
+        this.decrypted = decrypted;
+        this.stream = decrypted.stream;
+        this.tag = BitmessageAddress.calculateTag(4, decrypted.getStream(), decrypted.getRipe());
+    }
+
+    public static V4Pubkey read(InputStream in, long stream, int length, boolean encrypted) throws IOException {
+        if (encrypted)
+            return new V4Pubkey(stream,
+                    Decode.bytes(in, 32),
+                    CryptoBox.read(in, length - 32));
+        else
+            return new V4Pubkey(V3Pubkey.read(in, stream));
+    }
+
+    @Override
+    public void encrypt(byte[] publicKey) throws IOException {
+        if (getSignature() == null) throw new IllegalStateException("Pubkey must be signed before encryption.");
+        this.encrypted = new CryptoBox(decrypted, publicKey);
+    }
+
+    @Override
+    public void decrypt(byte[] privateKey) throws IOException, DecryptionFailedException {
+        decrypted = V3Pubkey.read(encrypted.decrypt(privateKey), stream);
+    }
+
+    @Override
+    public boolean isDecrypted() {
+        return decrypted != null;
+    }
+
+    @Override
+    public void write(OutputStream stream) throws IOException {
+        stream.write(tag);
+        encrypted.write(stream);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        buffer.put(tag);
+        encrypted.write(buffer);
+    }
+
+    @Override
+    public void writeUnencrypted(OutputStream out) throws IOException {
+        decrypted.write(out);
+    }
+
+    @Override
+    public void writeUnencrypted(ByteBuffer buffer) {
+        decrypted.write(buffer);
+    }
+
+    @Override
+    public void writeBytesToSign(OutputStream out) throws IOException {
+        out.write(tag);
+        decrypted.writeBytesToSign(out);
+    }
+
+    @Override
+    public long getVersion() {
+        return 4;
+    }
+
+    @Override
+    public ObjectType getType() {
+        return ObjectType.PUBKEY;
+    }
+
+    @Override
+    public long getStream() {
+        return stream;
+    }
+
+    public byte[] getTag() {
+        return tag;
+    }
+
+    @Override
+    public byte[] getSigningKey() {
+        return decrypted.getSigningKey();
+    }
+
+    @Override
+    public byte[] getEncryptionKey() {
+        return decrypted.getEncryptionKey();
+    }
+
+    @Override
+    public int getBehaviorBitfield() {
+        return decrypted.getBehaviorBitfield();
+    }
+
+    @Override
+    public byte[] getSignature() {
+        if (decrypted != null)
+            return decrypted.getSignature();
+        else
+            return null;
+    }
+
+    @Override
+    public void setSignature(byte[] signature) {
+        decrypted.setSignature(signature);
+    }
+
+    @Override
+    public boolean isSigned() {
+        return true;
+    }
+
+    public long getNonceTrialsPerByte() {
+        return decrypted.getNonceTrialsPerByte();
+    }
+
+    public long getExtraBytes() {
+        return decrypted.getExtraBytes();
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        V4Pubkey v4Pubkey = (V4Pubkey) o;
+
+        if (stream != v4Pubkey.stream) return false;
+        if (!Arrays.equals(tag, v4Pubkey.tag)) return false;
+        return !(decrypted != null ? !decrypted.equals(v4Pubkey.decrypted) : v4Pubkey.decrypted != null);
+
+    }
+
+    @Override
+    public int hashCode() {
+        int result = (int) (stream ^ (stream >>> 32));
+        result = 31 * result + Arrays.hashCode(tag);
+        result = 31 * result + (decrypted != null ? decrypted.hashCode() : 0);
+        return result;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/payload/V5Broadcast.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.payload;
+
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.Plaintext;
+import ch.dissem.bitmessage.utils.Decode;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+/**
+ * Users who are subscribed to the sending address will see the message appear in their inbox.
+ */
+public class V5Broadcast extends V4Broadcast {
+    private static final long serialVersionUID = 920649721626968644L;
+
+    private byte[] tag;
+
+    private V5Broadcast(long stream, byte[] tag, CryptoBox encrypted) {
+        super(5, stream, encrypted, null);
+        this.tag = tag;
+    }
+
+    public V5Broadcast(BitmessageAddress senderAddress, Plaintext plaintext) {
+        super(5, senderAddress.getStream(), null, plaintext);
+        if (senderAddress.getVersion() < 4)
+            throw new IllegalArgumentException("Address version 4 (or newer) expected, but was " + senderAddress.getVersion());
+        this.tag = senderAddress.getTag();
+    }
+
+    public static V5Broadcast read(InputStream is, long stream, int length) throws IOException {
+        return new V5Broadcast(stream, Decode.bytes(is, 32), CryptoBox.read(is, length - 32));
+    }
+
+    public byte[] getTag() {
+        return tag;
+    }
+
+    @Override
+    public void writeBytesToSign(OutputStream out) throws IOException {
+        out.write(tag);
+        super.writeBytesToSign(out);
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        out.write(tag);
+        super.write(out);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/valueobject/InventoryVector.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.valueobject;
+
+import ch.dissem.bitmessage.entity.Streamable;
+import ch.dissem.bitmessage.utils.Strings;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.Serializable;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
+public class InventoryVector implements Streamable, Serializable {
+    private static final long serialVersionUID = -7349009673063348719L;
+
+    /**
+     * Hash of the object
+     */
+    private final byte[] hash;
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (!(o instanceof InventoryVector)) return false;
+
+        InventoryVector that = (InventoryVector) o;
+
+        return Arrays.equals(hash, that.hash);
+    }
+
+    @Override
+    public int hashCode() {
+        return hash == null ? 0 : Arrays.hashCode(hash);
+    }
+
+    public byte[] getHash() {
+        return hash;
+    }
+
+    public InventoryVector(byte[] hash) {
+        this.hash = hash;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        out.write(hash);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        buffer.put(hash);
+    }
+
+    @Override
+    public String toString() {
+        return Strings.hex(hash).toString();
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/valueobject/Label.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.valueobject;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+public class Label implements Serializable {
+    private static final long serialVersionUID = 831782893630994914L;
+
+    private Object id;
+    private String label;
+    private Type type;
+    private int color;
+
+    public Label(String label, Type type, int color) {
+        this.label = label;
+        this.type = type;
+        this.color = color;
+    }
+
+    /**
+     * @return RGBA representation for the color.
+     */
+    public int getColor() {
+        return color;
+    }
+
+    /**
+     * @param color RGBA representation for the color.
+     */
+    public void setColor(int color) {
+        this.color = color;
+    }
+
+    @Override
+    public String toString() {
+        return label;
+    }
+
+    public Object getId() {
+        return id;
+    }
+
+    public void setId(Object id) {
+        this.id = id;
+    }
+
+    public Type getType() {
+        return type;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Label label1 = (Label) o;
+        return Objects.equals(label, label1.label);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(label);
+    }
+
+    public enum Type {
+        INBOX,
+        BROADCAST,
+        DRAFT,
+        OUTBOX,
+        SENT,
+        UNREAD,
+        TRASH
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/valueobject/NetworkAddress.java

@@ -0,0 +1,238 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.valueobject;
+
+import ch.dissem.bitmessage.entity.Streamable;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.utils.Encode;
+import ch.dissem.bitmessage.utils.UnixTime;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.SocketAddress;
+import java.net.UnknownHostException;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
+/**
+ * A node's address. It's written in IPv6 format.
+ */
+public class NetworkAddress implements Streamable {
+    private static final long serialVersionUID = 2500120578167100300L;
+
+    private long time;
+
+    /**
+     * Stream number for this node
+     */
+    private final long stream;
+
+    /**
+     * same service(s) listed in version
+     */
+    private final long services;
+
+    /**
+     * IPv6 address. IPv4 addresses are written into the message as a 16 byte IPv4-mapped IPv6 address
+     * (12 bytes 00 00 00 00 00 00 00 00 00 00 FF FF, followed by the 4 bytes of the IPv4 address).
+     */
+    private final byte[] ipv6;
+    private final int port;
+
+    private NetworkAddress(Builder builder) {
+        time = builder.time;
+        stream = builder.stream;
+        services = builder.services;
+        ipv6 = builder.ipv6;
+        port = builder.port;
+    }
+
+    public byte[] getIPv6() {
+        return ipv6;
+    }
+
+    public int getPort() {
+        return port;
+    }
+
+    public long getServices() {
+        return services;
+    }
+
+    public long getStream() {
+        return stream;
+    }
+
+    public long getTime() {
+        return time;
+    }
+
+    public void setTime(long time) {
+        this.time = time;
+    }
+
+    public InetAddress toInetAddress() {
+        try {
+            return InetAddress.getByAddress(ipv6);
+        } catch (UnknownHostException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        NetworkAddress that = (NetworkAddress) o;
+
+        return port == that.port && Arrays.equals(ipv6, that.ipv6);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = ipv6 != null ? Arrays.hashCode(ipv6) : 0;
+        result = 31 * result + port;
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "[" + toInetAddress() + "]:" + port;
+    }
+
+    @Override
+    public void write(OutputStream stream) throws IOException {
+        write(stream, false);
+    }
+
+    public void write(OutputStream out, boolean light) throws IOException {
+        if (!light) {
+            Encode.int64(time, out);
+            Encode.int32(stream, out);
+        }
+        Encode.int64(services, out);
+        out.write(ipv6);
+        Encode.int16(port, out);
+    }
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        write(buffer, false);
+    }
+
+    public void write(ByteBuffer buffer, boolean light) {
+        if (!light) {
+            Encode.int64(time, buffer);
+            Encode.int32(stream, buffer);
+        }
+        Encode.int64(services, buffer);
+        buffer.put(ipv6);
+        Encode.int16(port, buffer);
+    }
+
+    public static final class Builder {
+        private long time;
+        private long stream;
+        private long services = 1;
+        private byte[] ipv6;
+        private int port;
+
+        public Builder time(final long time) {
+            this.time = time;
+            return this;
+        }
+
+        public Builder stream(final long stream) {
+            this.stream = stream;
+            return this;
+        }
+
+        public Builder services(final long services) {
+            this.services = services;
+            return this;
+        }
+
+        public Builder ip(InetAddress inetAddress) {
+            byte[] addr = inetAddress.getAddress();
+            if (addr.length == 16) {
+                this.ipv6 = addr;
+            } else if (addr.length == 4) {
+                this.ipv6 = new byte[16];
+                this.ipv6[10] = (byte) 0xff;
+                this.ipv6[11] = (byte) 0xff;
+                System.arraycopy(addr, 0, this.ipv6, 12, 4);
+            } else {
+                throw new IllegalArgumentException("Weird address " + inetAddress);
+            }
+            return this;
+        }
+
+        public Builder ipv6(byte[] ipv6) {
+            this.ipv6 = ipv6;
+            return this;
+        }
+
+        public Builder ipv6(int p00, int p01, int p02, int p03,
+                            int p04, int p05, int p06, int p07,
+                            int p08, int p09, int p10, int p11,
+                            int p12, int p13, int p14, int p15) {
+            this.ipv6 = new byte[]{
+                    (byte) p00, (byte) p01, (byte) p02, (byte) p03,
+                    (byte) p04, (byte) p05, (byte) p06, (byte) p07,
+                    (byte) p08, (byte) p09, (byte) p10, (byte) p11,
+                    (byte) p12, (byte) p13, (byte) p14, (byte) p15
+            };
+            return this;
+        }
+
+        public Builder ipv4(int p00, int p01, int p02, int p03) {
+            this.ipv6 = new byte[]{
+                    (byte) 0, (byte) 0, (byte) 0x00, (byte) 0x00,
+                    (byte) 0, (byte) 0, (byte) 0x00, (byte) 0x00,
+                    (byte) 0, (byte) 0, (byte) 0xff, (byte) 0xff,
+                    (byte) p00, (byte) p01, (byte) p02, (byte) p03
+            };
+            return this;
+        }
+
+        public Builder port(final int port) {
+            this.port = port;
+            return this;
+        }
+
+        public Builder address(SocketAddress address) {
+            if (address instanceof InetSocketAddress) {
+                InetSocketAddress inetAddress = (InetSocketAddress) address;
+                ip(inetAddress.getAddress());
+                port(inetAddress.getPort());
+            } else {
+                throw new IllegalArgumentException("Unknown type of address: " + address.getClass());
+            }
+            return this;
+        }
+
+        public NetworkAddress build() {
+            if (time == 0) {
+                time = UnixTime.now();
+            }
+            return new NetworkAddress(this);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/entity/valueobject/PrivateKey.java

@@ -0,0 +1,198 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.entity.valueobject;
+
+import ch.dissem.bitmessage.InternalContext;
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.Streamable;
+import ch.dissem.bitmessage.entity.payload.Pubkey;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.factory.Factory;
+import ch.dissem.bitmessage.utils.Bytes;
+import ch.dissem.bitmessage.utils.Decode;
+import ch.dissem.bitmessage.utils.Encode;
+
+import java.io.*;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.List;
+
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * Represents a private key. Additional information (stream, version, features, ...) is stored in the accompanying
+ * {@link Pubkey} object.
+ */
+public class PrivateKey implements Streamable {
+    private static final long serialVersionUID = 8562555470709110558L;
+
+    public static final int PRIVATE_KEY_SIZE = 32;
+
+    private final byte[] privateSigningKey;
+    private final byte[] privateEncryptionKey;
+
+    private final Pubkey pubkey;
+
+    public PrivateKey(boolean shorter, long stream, long nonceTrialsPerByte, long extraBytes, Pubkey.Feature... features) {
+        byte[] privSK;
+        byte[] pubSK;
+        byte[] privEK;
+        byte[] pubEK;
+        byte[] ripe;
+        do {
+            privSK = cryptography().randomBytes(PRIVATE_KEY_SIZE);
+            privEK = cryptography().randomBytes(PRIVATE_KEY_SIZE);
+            pubSK = cryptography().createPublicKey(privSK);
+            pubEK = cryptography().createPublicKey(privEK);
+            ripe = Pubkey.getRipe(pubSK, pubEK);
+        } while (ripe[0] != 0 || (shorter && ripe[1] != 0));
+        this.privateSigningKey = privSK;
+        this.privateEncryptionKey = privEK;
+        this.pubkey = cryptography().createPubkey(Pubkey.LATEST_VERSION, stream, privateSigningKey, privateEncryptionKey,
+                nonceTrialsPerByte, extraBytes, features);
+    }
+
+    public PrivateKey(byte[] privateSigningKey, byte[] privateEncryptionKey, Pubkey pubkey) {
+        this.privateSigningKey = privateSigningKey;
+        this.privateEncryptionKey = privateEncryptionKey;
+        this.pubkey = pubkey;
+    }
+
+    public PrivateKey(BitmessageAddress address, String passphrase) {
+        this(address.getVersion(), address.getStream(), passphrase);
+    }
+
+    public PrivateKey(long version, long stream, String passphrase) {
+        this(new Builder(version, stream, false).seed(passphrase).generate());
+    }
+
+    private PrivateKey(Builder builder) {
+        this.privateSigningKey = builder.privSK;
+        this.privateEncryptionKey = builder.privEK;
+        this.pubkey = Factory.createPubkey(builder.version, builder.stream, builder.pubSK, builder.pubEK,
+                InternalContext.NETWORK_NONCE_TRIALS_PER_BYTE, InternalContext.NETWORK_EXTRA_BYTES);
+    }
+
+    private static class Builder {
+        final long version;
+        final long stream;
+        final boolean shorter;
+
+        byte[] seed;
+        long nextNonce;
+
+        byte[] privSK, privEK;
+        byte[] pubSK, pubEK;
+
+        private Builder(long version, long stream, boolean shorter) {
+            this.version = version;
+            this.stream = stream;
+            this.shorter = shorter;
+        }
+
+        Builder seed(String passphrase) {
+            try {
+                seed = passphrase.getBytes("UTF-8");
+            } catch (UnsupportedEncodingException e) {
+                throw new ApplicationException(e);
+            }
+            return this;
+        }
+
+        Builder generate() {
+            long signingKeyNonce = nextNonce;
+            long encryptionKeyNonce = nextNonce + 1;
+            byte[] ripe;
+            do {
+                privEK = Bytes.truncate(cryptography().sha512(seed, Encode.varInt(encryptionKeyNonce)), 32);
+                privSK = Bytes.truncate(cryptography().sha512(seed, Encode.varInt(signingKeyNonce)), 32);
+                pubSK = cryptography().createPublicKey(privSK);
+                pubEK = cryptography().createPublicKey(privEK);
+                ripe = cryptography().ripemd160(cryptography().sha512(pubSK, pubEK));
+
+                signingKeyNonce += 2;
+                encryptionKeyNonce += 2;
+            } while (ripe[0] != 0 || (shorter && ripe[1] != 0));
+            nextNonce = signingKeyNonce;
+            return this;
+        }
+    }
+
+    public static List<PrivateKey> deterministic(String passphrase, int numberOfAddresses, long version, long stream, boolean shorter) {
+        List<PrivateKey> result = new ArrayList<>(numberOfAddresses);
+        Builder builder = new Builder(version, stream, shorter).seed(passphrase);
+        for (int i = 0; i < numberOfAddresses; i++) {
+            builder.generate();
+            result.add(new PrivateKey(builder));
+        }
+        return result;
+    }
+
+    public static PrivateKey read(InputStream is) throws IOException {
+        int version = (int) Decode.varInt(is);
+        long stream = Decode.varInt(is);
+        int len = (int) Decode.varInt(is);
+        Pubkey pubkey = Factory.readPubkey(version, stream, is, len, false);
+        len = (int) Decode.varInt(is);
+        byte[] signingKey = Decode.bytes(is, len);
+        len = (int) Decode.varInt(is);
+        byte[] encryptionKey = Decode.bytes(is, len);
+        return new PrivateKey(signingKey, encryptionKey, pubkey);
+    }
+
+    public byte[] getPrivateSigningKey() {
+        return privateSigningKey;
+    }
+
+    public byte[] getPrivateEncryptionKey() {
+        return privateEncryptionKey;
+    }
+
+    public Pubkey getPubkey() {
+        return pubkey;
+    }
+
+    @Override
+    public void write(OutputStream out) throws IOException {
+        Encode.varInt(pubkey.getVersion(), out);
+        Encode.varInt(pubkey.getStream(), out);
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        pubkey.writeUnencrypted(baos);
+        Encode.varInt(baos.size(), out);
+        out.write(baos.toByteArray());
+        Encode.varInt(privateSigningKey.length, out);
+        out.write(privateSigningKey);
+        Encode.varInt(privateEncryptionKey.length, out);
+        out.write(privateEncryptionKey);
+    }
+
+
+    @Override
+    public void write(ByteBuffer buffer) {
+        Encode.varInt(pubkey.getVersion(), buffer);
+        Encode.varInt(pubkey.getStream(), buffer);
+        try {
+            ByteArrayOutputStream baos = new ByteArrayOutputStream();
+            pubkey.writeUnencrypted(baos);
+            Encode.varBytes(baos.toByteArray(), buffer);
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+        Encode.varBytes(privateSigningKey, buffer);
+        Encode.varBytes(privateEncryptionKey, buffer);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/exception/AddressFormatException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,9 +14,15 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.exception
+package ch.dissem.bitmessage.exception;
 
 /**
  * Indicates an illegal Bitmessage address
  */
-class AddressFormatException(message: String) : RuntimeException(message)
+public class AddressFormatException extends RuntimeException {
+    private static final long serialVersionUID = 6943764578672021573L;
+
+    public AddressFormatException(String message) {
+        super(message);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/exception/ApplicationException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2016 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,20 +14,19 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.utils
-
-import ch.dissem.bitmessage.cryptography.bc.BouncyCryptography
-import org.junit.jupiter.api.BeforeAll
+package ch.dissem.bitmessage.exception;
 
 /**
  * @author Christian Basler
  */
-open class TestBase {
-    companion object {
-        @BeforeAll
-        @JvmStatic
-        fun setUpClass() {
-            Singleton.initialize(BouncyCryptography())
-        }
+public class ApplicationException extends RuntimeException {
+    private static final long serialVersionUID = 1796776684126759324L;
+
+    public ApplicationException(Throwable cause) {
+        super(cause);
+    }
+
+    public ApplicationException(String message) {
+        super(message);
     }
 }

core/src/main/java/ch/dissem/bitmessage/exception/DecryptionFailedException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,10 +14,8 @@
  * limitations under the License.
  */
 
-@file:JvmName("Numbers")
+package ch.dissem.bitmessage.exception;
 
-package ch.dissem.bitmessage.utils
-
-fun max(a: Long, b: Long): Long {
-    return if (a > b) a else b
+public class DecryptionFailedException extends Exception {
+    private static final long serialVersionUID = 3241116253113872731L;
 }

core/src/main/java/ch/dissem/bitmessage/exception/InsufficientProofOfWorkException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,20 +14,17 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.ports
+package ch.dissem.bitmessage.exception;
 
-import ch.dissem.bitmessage.entity.valueobject.Label
-import ch.dissem.bitmessage.utils.SqlStrings.join
+import ch.dissem.bitmessage.utils.Strings;
 
-abstract class AbstractLabelRepository : LabelRepository {
+import java.io.IOException;
+import java.util.Arrays;
 
-    override fun getLabels(): List<Label> {
-        return find("1=1")
+public class InsufficientProofOfWorkException extends IOException {
+    private static final long serialVersionUID = 9105580366564571318L;
+
+    public InsufficientProofOfWorkException(byte[] target, byte[] hash) {
+        super("Insufficient proof of work: " + Strings.hex(target) + " required, " + Strings.hex(Arrays.copyOfRange(hash, 0, 8)) + " achieved.");
     }
-
-    override fun getLabels(vararg types: Label.Type): List<Label> {
-        return find("type IN (${join(*types)})")
-    }
-
-    protected abstract fun find(where: String): List<Label>
 }

core/src/main/java/ch/dissem/bitmessage/exception/NodeException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,13 +14,21 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.exception
+package ch.dissem.bitmessage.exception;
 
 /**
  * An exception on the node that's severe enough to cause the client to disconnect this node.
-
+ *
  * @author Ch. Basler
  */
-class NodeException(message: String?, cause: Throwable? = null) : RuntimeException(message ?: cause?.message, cause) {
-    constructor(message: String) : this(message, null)
+public class NodeException extends RuntimeException {
+    private static final long serialVersionUID = 2965325796118227802L;
+
+    public NodeException(String message) {
+        super(message);
+    }
+
+    public NodeException(String message, Throwable cause) {
+        super(message, cause);
+    }
 }

core/src/main/java/ch/dissem/bitmessage/factory/BufferPool.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2016 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.factory;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.nio.ByteBuffer;
+import java.util.Map;
+import java.util.Stack;
+import java.util.TreeMap;
+
+import static ch.dissem.bitmessage.ports.NetworkHandler.HEADER_SIZE;
+import static ch.dissem.bitmessage.ports.NetworkHandler.MAX_PAYLOAD_SIZE;
+
+/**
+ * A pool for {@link ByteBuffer}s. As they may use up a lot of memory,
+ * they should be reused as efficiently as possible.
+ */
+class BufferPool {
+    private static final Logger LOG = LoggerFactory.getLogger(BufferPool.class);
+
+    public static final BufferPool bufferPool = new BufferPool();
+
+    private final Map<Integer, Stack<ByteBuffer>> pools = new TreeMap<>();
+
+    private BufferPool() {
+        pools.put(HEADER_SIZE, new Stack<ByteBuffer>());
+        pools.put(54, new Stack<ByteBuffer>());
+        pools.put(1000, new Stack<ByteBuffer>());
+        pools.put(60000, new Stack<ByteBuffer>());
+        pools.put(MAX_PAYLOAD_SIZE, new Stack<ByteBuffer>());
+    }
+
+    public synchronized ByteBuffer allocate(int capacity) {
+        Integer targetSize = getTargetSize(capacity);
+        Stack<ByteBuffer> pool = pools.get(targetSize);
+        if (pool.isEmpty()) {
+            LOG.trace("Creating new buffer of size " + targetSize);
+            return ByteBuffer.allocate(targetSize);
+        } else {
+            return pool.pop();
+        }
+    }
+
+    /**
+     * Returns a buffer that has the size of the Bitmessage network message header, 24 bytes.
+     *
+     * @return a buffer of size 24
+     */
+    public synchronized ByteBuffer allocateHeaderBuffer() {
+        Stack<ByteBuffer> pool = pools.get(HEADER_SIZE);
+        if (pool.isEmpty()) {
+            return ByteBuffer.allocate(HEADER_SIZE);
+        } else {
+            return pool.pop();
+        }
+    }
+
+    public synchronized void deallocate(ByteBuffer buffer) {
+        buffer.clear();
+        Stack<ByteBuffer> pool = pools.get(buffer.capacity());
+        if (pool == null) {
+            throw new IllegalArgumentException("Illegal buffer capacity " + buffer.capacity() +
+                " one of " + pools.keySet() + " expected.");
+        } else {
+            pool.push(buffer);
+        }
+    }
+
+    private Integer getTargetSize(int capacity) {
+        for (Integer size : pools.keySet()) {
+            if (size >= capacity) return size;
+        }
+        throw new IllegalArgumentException("Requested capacity too large: " +
+            "requested=" + capacity + "; max=" + MAX_PAYLOAD_SIZE);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/factory/Factory.java

@@ -0,0 +1,217 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.factory;
+
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.NetworkMessage;
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.entity.Plaintext;
+import ch.dissem.bitmessage.entity.payload.*;
+import ch.dissem.bitmessage.entity.valueobject.PrivateKey;
+import ch.dissem.bitmessage.exception.NodeException;
+import ch.dissem.bitmessage.utils.TTL;
+import ch.dissem.bitmessage.utils.UnixTime;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.SocketException;
+import java.net.SocketTimeoutException;
+
+import static ch.dissem.bitmessage.entity.payload.ObjectType.MSG;
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * Creates {@link NetworkMessage} objects from {@link InputStream InputStreams}
+ */
+public class Factory {
+    private static final Logger LOG = LoggerFactory.getLogger(Factory.class);
+
+    public static NetworkMessage getNetworkMessage(int version, InputStream stream) throws SocketTimeoutException {
+        try {
+            return V3MessageFactory.read(stream);
+        } catch (SocketTimeoutException | NodeException e) {
+            throw e;
+        } catch (SocketException e) {
+            throw new NodeException(e.getMessage(), e);
+        } catch (Exception e) {
+            LOG.error(e.getMessage(), e);
+            return null;
+        }
+    }
+
+    public static ObjectMessage getObjectMessage(int version, InputStream stream, int length) {
+        try {
+            return V3MessageFactory.readObject(stream, length);
+        } catch (IOException e) {
+            LOG.error(e.getMessage(), e);
+            return null;
+        }
+    }
+
+    public static Pubkey createPubkey(long version, long stream, byte[] publicSigningKey, byte[] publicEncryptionKey,
+                                      long nonceTrialsPerByte, long extraBytes, Pubkey.Feature... features) {
+        return createPubkey(version, stream, publicSigningKey, publicEncryptionKey, nonceTrialsPerByte, extraBytes,
+                Pubkey.Feature.bitfield(features));
+    }
+
+    public static Pubkey createPubkey(long version, long stream, byte[] publicSigningKey, byte[] publicEncryptionKey,
+                                      long nonceTrialsPerByte, long extraBytes, int behaviourBitfield) {
+        if (publicSigningKey.length != 64 && publicSigningKey.length != 65)
+            throw new IllegalArgumentException("64 bytes signing key expected, but it was "
+                    + publicSigningKey.length + " bytes long.");
+        if (publicEncryptionKey.length != 64 && publicEncryptionKey.length != 65)
+            throw new IllegalArgumentException("64 bytes encryption key expected, but it was "
+                    + publicEncryptionKey.length + " bytes long.");
+
+        switch ((int) version) {
+            case 2:
+                return new V2Pubkey.Builder()
+                        .stream(stream)
+                        .publicSigningKey(publicSigningKey)
+                        .publicEncryptionKey(publicEncryptionKey)
+                        .behaviorBitfield(behaviourBitfield)
+                        .build();
+            case 3:
+                return new V3Pubkey.Builder()
+                        .stream(stream)
+                        .publicSigningKey(publicSigningKey)
+                        .publicEncryptionKey(publicEncryptionKey)
+                        .behaviorBitfield(behaviourBitfield)
+                        .nonceTrialsPerByte(nonceTrialsPerByte)
+                        .extraBytes(extraBytes)
+                        .build();
+            case 4:
+                return new V4Pubkey(
+                        new V3Pubkey.Builder()
+                                .stream(stream)
+                                .publicSigningKey(publicSigningKey)
+                                .publicEncryptionKey(publicEncryptionKey)
+                                .behaviorBitfield(behaviourBitfield)
+                                .nonceTrialsPerByte(nonceTrialsPerByte)
+                                .extraBytes(extraBytes)
+                                .build()
+                );
+            default:
+                throw new IllegalArgumentException("Unexpected pubkey version " + version);
+        }
+    }
+
+    public static BitmessageAddress createIdentityFromPrivateKey(String address,
+                                                                 byte[] privateSigningKey, byte[] privateEncryptionKey,
+                                                                 long nonceTrialsPerByte, long extraBytes,
+                                                                 int behaviourBitfield) {
+        BitmessageAddress temp = new BitmessageAddress(address);
+        PrivateKey privateKey = new PrivateKey(privateSigningKey, privateEncryptionKey,
+                createPubkey(temp.getVersion(), temp.getStream(),
+                        cryptography().createPublicKey(privateSigningKey),
+                        cryptography().createPublicKey(privateEncryptionKey),
+                        nonceTrialsPerByte, extraBytes, behaviourBitfield));
+        BitmessageAddress result = new BitmessageAddress(privateKey);
+        if (!result.getAddress().equals(address)) {
+            throw new IllegalArgumentException("Address not matching private key. Address: " + address
+                    + "; Address derived from private key: " + result.getAddress());
+        }
+        return result;
+    }
+
+    public static BitmessageAddress generatePrivateAddress(boolean shorter,
+                                                           long stream,
+                                                           Pubkey.Feature... features) {
+        return new BitmessageAddress(new PrivateKey(shorter, stream, 1000, 1000, features));
+    }
+
+    static ObjectPayload getObjectPayload(long objectType,
+                                          long version,
+                                          long streamNumber,
+                                          InputStream stream,
+                                          int length) throws IOException {
+        ObjectType type = ObjectType.fromNumber(objectType);
+        if (type != null) {
+            switch (type) {
+                case GET_PUBKEY:
+                    return parseGetPubkey(version, streamNumber, stream, length);
+                case PUBKEY:
+                    return parsePubkey(version, streamNumber, stream, length);
+                case MSG:
+                    return parseMsg(version, streamNumber, stream, length);
+                case BROADCAST:
+                    return parseBroadcast(version, streamNumber, stream, length);
+                default:
+                    LOG.error("This should not happen, someone broke something in the code!");
+            }
+        }
+        // fallback: just store the message - we don't really care what it is
+        LOG.trace("Unexpected object type: " + objectType);
+        return GenericPayload.read(version, streamNumber, stream, length);
+    }
+
+    private static ObjectPayload parseGetPubkey(long version, long streamNumber, InputStream stream, int length) throws IOException {
+        return GetPubkey.read(stream, streamNumber, length, version);
+    }
+
+    public static Pubkey readPubkey(long version, long stream, InputStream is, int length, boolean encrypted) throws IOException {
+        switch ((int) version) {
+            case 2:
+                return V2Pubkey.read(is, stream);
+            case 3:
+                return V3Pubkey.read(is, stream);
+            case 4:
+                return V4Pubkey.read(is, stream, length, encrypted);
+        }
+        LOG.debug("Unexpected pubkey version " + version + ", handling as generic payload object");
+        return null;
+    }
+
+    private static ObjectPayload parsePubkey(long version, long streamNumber, InputStream stream, int length) throws IOException {
+        Pubkey pubkey = readPubkey(version, streamNumber, stream, length, true);
+        return pubkey != null ? pubkey : GenericPayload.read(version, streamNumber, stream, length);
+    }
+
+    private static ObjectPayload parseMsg(long version, long streamNumber, InputStream stream, int length) throws IOException {
+        return Msg.read(stream, streamNumber, length);
+    }
+
+    private static ObjectPayload parseBroadcast(long version, long streamNumber, InputStream stream, int length) throws IOException {
+        switch ((int) version) {
+            case 4:
+                return V4Broadcast.read(stream, streamNumber, length);
+            case 5:
+                return V5Broadcast.read(stream, streamNumber, length);
+            default:
+                LOG.debug("Encountered unknown broadcast version " + version);
+                return GenericPayload.read(version, streamNumber, stream, length);
+        }
+    }
+
+    public static Broadcast getBroadcast(Plaintext plaintext) {
+        BitmessageAddress sendingAddress = plaintext.getFrom();
+        if (sendingAddress.getVersion() < 4) {
+            return new V4Broadcast(sendingAddress, plaintext);
+        } else {
+            return new V5Broadcast(sendingAddress, plaintext);
+        }
+    }
+
+    public static ObjectMessage createAck(Plaintext plaintext) {
+        if (plaintext == null || plaintext.getAckData() == null)
+            return null;
+        GenericPayload ack = new GenericPayload(3, plaintext.getFrom().getStream(), plaintext.getAckData());
+        return new ObjectMessage.Builder().objectType(MSG).payload(ack).expiresTime(UnixTime.now(plaintext.getTTL())).build();
+    }
+}

core/src/main/java/ch/dissem/bitmessage/factory/V3MessageFactory.java

@@ -0,0 +1,232 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.factory;
+
+import ch.dissem.bitmessage.entity.*;
+import ch.dissem.bitmessage.entity.payload.GenericPayload;
+import ch.dissem.bitmessage.entity.payload.ObjectPayload;
+import ch.dissem.bitmessage.entity.valueobject.InventoryVector;
+import ch.dissem.bitmessage.entity.valueobject.NetworkAddress;
+import ch.dissem.bitmessage.exception.NodeException;
+import ch.dissem.bitmessage.utils.AccessCounter;
+import ch.dissem.bitmessage.utils.Decode;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+import static ch.dissem.bitmessage.entity.NetworkMessage.MAGIC_BYTES;
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * Creates protocol v3 network messages from {@link InputStream InputStreams}
+ */
+class V3MessageFactory {
+    private static Logger LOG = LoggerFactory.getLogger(V3MessageFactory.class);
+
+    public static NetworkMessage read(InputStream in) throws IOException {
+        findMagic(in);
+        String command = getCommand(in);
+        int length = (int) Decode.uint32(in);
+        if (length > 1600003) {
+            throw new NodeException("Payload of " + length + " bytes received, no more than 1600003 was expected.");
+        }
+        byte[] checksum = Decode.bytes(in, 4);
+
+        byte[] payloadBytes = Decode.bytes(in, length);
+
+        if (testChecksum(checksum, payloadBytes)) {
+            MessagePayload payload = getPayload(command, new ByteArrayInputStream(payloadBytes), length);
+            if (payload != null)
+                return new NetworkMessage(payload);
+            else
+                return null;
+        } else {
+            throw new IOException("Checksum failed for message '" + command + "'");
+        }
+    }
+
+    static MessagePayload getPayload(String command, InputStream stream, int length) throws IOException {
+        switch (command) {
+            case "version":
+                return parseVersion(stream);
+            case "verack":
+                return new VerAck();
+            case "addr":
+                return parseAddr(stream);
+            case "inv":
+                return parseInv(stream);
+            case "getdata":
+                return parseGetData(stream);
+            case "object":
+                return readObject(stream, length);
+            case "custom":
+                return readCustom(stream, length);
+            default:
+                LOG.debug("Unknown command: " + command);
+                return null;
+        }
+    }
+
+    private static MessagePayload readCustom(InputStream in, int length) throws IOException {
+        return CustomMessage.read(in, length);
+    }
+
+    public static ObjectMessage readObject(InputStream in, int length) throws IOException {
+        AccessCounter counter = new AccessCounter();
+        byte nonce[] = Decode.bytes(in, 8, counter);
+        long expiresTime = Decode.int64(in, counter);
+        long objectType = Decode.uint32(in, counter);
+        long version = Decode.varInt(in, counter);
+        long stream = Decode.varInt(in, counter);
+
+        byte[] data = Decode.bytes(in, length - counter.length());
+        ObjectPayload payload;
+        try {
+            ByteArrayInputStream dataStream = new ByteArrayInputStream(data);
+            payload = Factory.getObjectPayload(objectType, version, stream, dataStream, data.length);
+        } catch (Exception e) {
+            LOG.trace("Could not parse object payload - using generic payload instead", e);
+            payload = new GenericPayload(version, stream, data);
+        }
+
+        return new ObjectMessage.Builder()
+            .nonce(nonce)
+            .expiresTime(expiresTime)
+            .objectType(objectType)
+            .stream(stream)
+            .payload(payload)
+            .build();
+    }
+
+    private static GetData parseGetData(InputStream stream) throws IOException {
+        long count = Decode.varInt(stream);
+        GetData.Builder builder = new GetData.Builder();
+        for (int i = 0; i < count; i++) {
+            builder.addInventoryVector(parseInventoryVector(stream));
+        }
+        return builder.build();
+    }
+
+    private static Inv parseInv(InputStream stream) throws IOException {
+        long count = Decode.varInt(stream);
+        Inv.Builder builder = new Inv.Builder();
+        for (int i = 0; i < count; i++) {
+            builder.addInventoryVector(parseInventoryVector(stream));
+        }
+        return builder.build();
+    }
+
+    private static Addr parseAddr(InputStream stream) throws IOException {
+        long count = Decode.varInt(stream);
+        Addr.Builder builder = new Addr.Builder();
+        for (int i = 0; i < count; i++) {
+            builder.addAddress(parseAddress(stream, false));
+        }
+        return builder.build();
+    }
+
+    private static Version parseVersion(InputStream stream) throws IOException {
+        int version = Decode.int32(stream);
+        long services = Decode.int64(stream);
+        long timestamp = Decode.int64(stream);
+        NetworkAddress addrRecv = parseAddress(stream, true);
+        NetworkAddress addrFrom = parseAddress(stream, true);
+        long nonce = Decode.int64(stream);
+        String userAgent = Decode.varString(stream);
+        long[] streamNumbers = Decode.varIntList(stream);
+
+        return new Version.Builder()
+            .version(version)
+            .services(services)
+            .timestamp(timestamp)
+            .addrRecv(addrRecv).addrFrom(addrFrom)
+            .nonce(nonce)
+            .userAgent(userAgent)
+            .streams(streamNumbers).build();
+    }
+
+    private static InventoryVector parseInventoryVector(InputStream stream) throws IOException {
+        return new InventoryVector(Decode.bytes(stream, 32));
+    }
+
+    private static NetworkAddress parseAddress(InputStream stream, boolean light) throws IOException {
+        long time;
+        long streamNumber;
+        if (!light) {
+            time = Decode.int64(stream);
+            streamNumber = Decode.uint32(stream); // This isn't consistent, not sure if this is correct
+        } else {
+            time = 0;
+            streamNumber = 0;
+        }
+        long services = Decode.int64(stream);
+        byte[] ipv6 = Decode.bytes(stream, 16);
+        int port = Decode.uint16(stream);
+        return new NetworkAddress.Builder()
+            .time(time)
+            .stream(streamNumber)
+            .services(services)
+            .ipv6(ipv6)
+            .port(port)
+            .build();
+    }
+
+    private static boolean testChecksum(byte[] checksum, byte[] payload) {
+        byte[] payloadChecksum = cryptography().sha512(payload);
+        for (int i = 0; i < checksum.length; i++) {
+            if (checksum[i] != payloadChecksum[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private static String getCommand(InputStream stream) throws IOException {
+        byte[] bytes = new byte[12];
+        int end = bytes.length;
+        for (int i = 0; i < bytes.length; i++) {
+            bytes[i] = (byte) stream.read();
+            if (end == bytes.length) {
+                if (bytes[i] == 0) end = i;
+            } else {
+                if (bytes[i] != 0) throw new IOException("'\\0' padding expected for command");
+            }
+        }
+        return new String(bytes, 0, end, "ASCII");
+    }
+
+    private static void findMagic(InputStream in) throws IOException {
+        int pos = 0;
+        for (int i = 0; i < 1620000; i++) {
+            byte b = (byte) in.read();
+            if (b == MAGIC_BYTES[pos]) {
+                if (pos + 1 == MAGIC_BYTES.length) {
+                    return;
+                }
+            } else if (pos > 0 && b == MAGIC_BYTES[0]) {
+                pos = 1;
+            } else {
+                pos = 0;
+            }
+            pos++;
+        }
+        throw new NodeException("Failed to find MAGIC bytes in stream");
+    }
+}

core/src/main/java/ch/dissem/bitmessage/factory/V3MessageReader.java

@@ -0,0 +1,189 @@
+/*
+ * Copyright 2016 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.factory;
+
+import ch.dissem.bitmessage.entity.MessagePayload;
+import ch.dissem.bitmessage.entity.NetworkMessage;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.exception.NodeException;
+import ch.dissem.bitmessage.utils.Decode;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.nio.ByteBuffer;
+import java.util.LinkedList;
+import java.util.List;
+
+import static ch.dissem.bitmessage.entity.NetworkMessage.MAGIC_BYTES;
+import static ch.dissem.bitmessage.factory.BufferPool.bufferPool;
+import static ch.dissem.bitmessage.ports.NetworkHandler.MAX_PAYLOAD_SIZE;
+import static ch.dissem.bitmessage.utils.Singleton.cryptography;
+
+/**
+ * Similar to the {@link V3MessageFactory}, but used for NIO buffers which may or may not contain a whole message.
+ */
+public class V3MessageReader {
+    private ByteBuffer headerBuffer;
+    private ByteBuffer dataBuffer;
+
+    private ReaderState state = ReaderState.MAGIC;
+    private String command;
+    private int length;
+    private byte[] checksum;
+
+    private List<NetworkMessage> messages = new LinkedList<>();
+
+    public ByteBuffer getActiveBuffer() {
+        if (state != null && state != ReaderState.DATA) {
+            if (headerBuffer == null) {
+                headerBuffer = bufferPool.allocateHeaderBuffer();
+            }
+        }
+        return state == ReaderState.DATA ? dataBuffer : headerBuffer;
+    }
+
+    public void update() {
+        if (state != ReaderState.DATA) {
+            getActiveBuffer();
+            headerBuffer.flip();
+        }
+        switch (state) {
+            case MAGIC:
+                if (!findMagicBytes(headerBuffer)) {
+                    headerBuffer.compact();
+                    return;
+                }
+                state = ReaderState.HEADER;
+            case HEADER:
+                if (headerBuffer.remaining() < 20) {
+                    headerBuffer.compact();
+                    headerBuffer.limit(20);
+                    return;
+                }
+                command = getCommand(headerBuffer);
+                length = (int) Decode.uint32(headerBuffer);
+                if (length > MAX_PAYLOAD_SIZE) {
+                    throw new NodeException("Payload of " + length + " bytes received, no more than " +
+                        MAX_PAYLOAD_SIZE + " was expected.");
+                }
+                checksum = new byte[4];
+                headerBuffer.get(checksum);
+                state = ReaderState.DATA;
+                bufferPool.deallocate(headerBuffer);
+                headerBuffer = null;
+                dataBuffer = bufferPool.allocate(length);
+                dataBuffer.clear();
+                dataBuffer.limit(length);
+            case DATA:
+                if (dataBuffer.position() < length) {
+                    return;
+                } else {
+                    dataBuffer.flip();
+                }
+                if (!testChecksum(dataBuffer)) {
+                    state = ReaderState.MAGIC;
+                    throw new NodeException("Checksum failed for message '" + command + "'");
+                }
+                try {
+                    MessagePayload payload = V3MessageFactory.getPayload(
+                        command,
+                        new ByteArrayInputStream(dataBuffer.array(),
+                            dataBuffer.arrayOffset() + dataBuffer.position(), length),
+                        length);
+                    if (payload != null) {
+                        messages.add(new NetworkMessage(payload));
+                    }
+                } catch (IOException e) {
+                    throw new NodeException(e.getMessage());
+                } finally {
+                    state = ReaderState.MAGIC;
+                    bufferPool.deallocate(dataBuffer);
+                    dataBuffer = null;
+                    dataBuffer = null;
+                }
+        }
+    }
+
+    public List<NetworkMessage> getMessages() {
+        return messages;
+    }
+
+    private boolean findMagicBytes(ByteBuffer buffer) {
+        int i = 0;
+        while (buffer.hasRemaining()) {
+            if (i == 0) {
+                buffer.mark();
+            }
+            if (buffer.get() == MAGIC_BYTES[i]) {
+                i++;
+                if (i == MAGIC_BYTES.length) {
+                    return true;
+                }
+            } else {
+                i = 0;
+            }
+        }
+        if (i > 0) {
+            buffer.reset();
+        }
+        return false;
+    }
+
+    private static String getCommand(ByteBuffer buffer) {
+        int start = buffer.position();
+        int l = 0;
+        while (l < 12 && buffer.get() != 0) l++;
+        int i = l + 1;
+        while (i < 12) {
+            if (buffer.get() != 0) throw new NodeException("'\\0' padding expected for command");
+            i++;
+        }
+        try {
+            return new String(buffer.array(), start, l, "ASCII");
+        } catch (UnsupportedEncodingException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    private boolean testChecksum(ByteBuffer buffer) {
+        byte[] payloadChecksum = cryptography().sha512(buffer.array(),
+            buffer.arrayOffset() + buffer.position(), length);
+        for (int i = 0; i < checksum.length; i++) {
+            if (checksum[i] != payloadChecksum[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * De-allocates all buffers. This method should be called iff the reader isn't used anymore, i.e. when its
+     * connection is severed.
+     */
+    public void cleanup() {
+        state = null;
+        if (headerBuffer != null) {
+            bufferPool.deallocate(headerBuffer);
+        }
+        if (dataBuffer != null) {
+            bufferPool.deallocate(dataBuffer);
+        }
+    }
+
+    private enum ReaderState {MAGIC, HEADER, DATA}
+}

core/src/main/java/ch/dissem/bitmessage/ports/AbstractCryptography.java

@@ -0,0 +1,192 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.InternalContext;
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.entity.payload.Pubkey;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.exception.InsufficientProofOfWorkException;
+import ch.dissem.bitmessage.factory.Factory;
+import ch.dissem.bitmessage.utils.Bytes;
+import ch.dissem.bitmessage.utils.UnixTime;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.crypto.Mac;
+import javax.crypto.spec.SecretKeySpec;
+import java.io.IOException;
+import java.math.BigInteger;
+import java.security.GeneralSecurityException;
+import java.security.MessageDigest;
+import java.security.Provider;
+import java.security.SecureRandom;
+
+import static ch.dissem.bitmessage.InternalContext.NETWORK_EXTRA_BYTES;
+import static ch.dissem.bitmessage.InternalContext.NETWORK_NONCE_TRIALS_PER_BYTE;
+import static ch.dissem.bitmessage.utils.Numbers.max;
+
+/**
+ * Implements everything that isn't directly dependent on either Spongy- or Bouncycastle.
+ */
+public abstract class AbstractCryptography implements Cryptography, InternalContext.ContextHolder {
+    protected static final Logger LOG = LoggerFactory.getLogger(Cryptography.class);
+    private static final SecureRandom RANDOM = new SecureRandom();
+    private static final BigInteger TWO = BigInteger.valueOf(2);
+    private static final BigInteger TWO_POW_64 = TWO.pow(64);
+    private static final BigInteger TWO_POW_16 = TWO.pow(16);
+
+    protected final Provider provider;
+    private InternalContext context;
+
+    protected AbstractCryptography(Provider provider) {
+        this.provider = provider;
+    }
+
+    @Override
+    public void setContext(InternalContext context) {
+        this.context = context;
+    }
+
+    public byte[] sha512(byte[] data, int offset, int length) {
+        MessageDigest mda = md("SHA-512");
+        mda.update(data, offset, length);
+        return mda.digest();
+    }
+
+    public byte[] sha512(byte[]... data) {
+        return hash("SHA-512", data);
+    }
+
+    public byte[] doubleSha512(byte[]... data) {
+        MessageDigest mda = md("SHA-512");
+        for (byte[] d : data) {
+            mda.update(d);
+        }
+        return mda.digest(mda.digest());
+    }
+
+    public byte[] doubleSha512(byte[] data, int length) {
+        MessageDigest mda = md("SHA-512");
+        mda.update(data, 0, length);
+        return mda.digest(mda.digest());
+    }
+
+    public byte[] ripemd160(byte[]... data) {
+        return hash("RIPEMD160", data);
+    }
+
+    public byte[] doubleSha256(byte[] data, int length) {
+        MessageDigest mda = md("SHA-256");
+        mda.update(data, 0, length);
+        return mda.digest(mda.digest());
+    }
+
+    public byte[] sha1(byte[]... data) {
+        return hash("SHA-1", data);
+    }
+
+    public byte[] randomBytes(int length) {
+        byte[] result = new byte[length];
+        RANDOM.nextBytes(result);
+        return result;
+    }
+
+    public void doProofOfWork(ObjectMessage object, long nonceTrialsPerByte,
+                              long extraBytes, ProofOfWorkEngine.Callback callback) {
+        nonceTrialsPerByte = max(nonceTrialsPerByte, NETWORK_NONCE_TRIALS_PER_BYTE);
+        extraBytes = max(extraBytes, NETWORK_EXTRA_BYTES);
+
+        byte[] initialHash = getInitialHash(object);
+
+        byte[] target = getProofOfWorkTarget(object, nonceTrialsPerByte, extraBytes);
+
+        context.getProofOfWorkEngine().calculateNonce(initialHash, target, callback);
+    }
+
+    public void checkProofOfWork(ObjectMessage object, long nonceTrialsPerByte, long extraBytes)
+            throws IOException {
+        byte[] target = getProofOfWorkTarget(object, nonceTrialsPerByte, extraBytes);
+        byte[] value = doubleSha512(object.getNonce(), getInitialHash(object));
+        if (Bytes.lt(target, value, 8)) {
+            throw new InsufficientProofOfWorkException(target, value);
+        }
+    }
+
+    @Override
+    public byte[] getInitialHash(ObjectMessage object) {
+        return sha512(object.getPayloadBytesWithoutNonce());
+    }
+
+    @Override
+    public byte[] getProofOfWorkTarget(ObjectMessage object, long nonceTrialsPerByte, long extraBytes) {
+        if (nonceTrialsPerByte == 0) nonceTrialsPerByte = NETWORK_NONCE_TRIALS_PER_BYTE;
+        if (extraBytes == 0) extraBytes = NETWORK_EXTRA_BYTES;
+
+        BigInteger TTL = BigInteger.valueOf(object.getExpiresTime() - UnixTime.now());
+        BigInteger powLength = BigInteger.valueOf(object.getPayloadBytesWithoutNonce().length + extraBytes);
+        BigInteger denominator = BigInteger.valueOf(nonceTrialsPerByte)
+                .multiply(
+                        powLength.add(
+                                powLength.multiply(TTL).divide(TWO_POW_16)
+                        )
+                );
+        return Bytes.expand(TWO_POW_64.divide(denominator).toByteArray(), 8);
+    }
+
+    private byte[] hash(String algorithm, byte[]... data) {
+        MessageDigest mda = md(algorithm);
+        for (byte[] d : data) {
+            mda.update(d);
+        }
+        return mda.digest();
+    }
+
+    private MessageDigest md(String algorithm) {
+        try {
+            return MessageDigest.getInstance(algorithm, provider);
+        } catch (GeneralSecurityException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public byte[] mac(byte[] key_m, byte[] data) {
+        try {
+            Mac mac = Mac.getInstance("HmacSHA256", provider);
+            mac.init(new SecretKeySpec(key_m, "HmacSHA256"));
+            return mac.doFinal(data);
+        } catch (GeneralSecurityException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public Pubkey createPubkey(long version, long stream, byte[] privateSigningKey, byte[] privateEncryptionKey,
+                               long nonceTrialsPerByte, long extraBytes, Pubkey.Feature... features) {
+        return Factory.createPubkey(version, stream,
+                createPublicKey(privateSigningKey),
+                createPublicKey(privateEncryptionKey),
+                nonceTrialsPerByte, extraBytes, features);
+    }
+
+    public BigInteger keyToBigInt(byte[] privateKey) {
+        return new BigInteger(1, privateKey);
+    }
+
+    public long randomNonce() {
+        return RANDOM.nextLong();
+    }
+}

core/src/main/java/ch/dissem/bitmessage/ports/AbstractMessageRepository.java

@@ -0,0 +1,127 @@
+/*
+ * Copyright 2016 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.InternalContext;
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.Plaintext;
+import ch.dissem.bitmessage.entity.valueobject.Label;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.utils.Strings;
+import ch.dissem.bitmessage.utils.UnixTime;
+
+import java.util.Collection;
+import java.util.List;
+
+import static ch.dissem.bitmessage.utils.SqlStrings.join;
+
+public abstract class AbstractMessageRepository implements MessageRepository, InternalContext.ContextHolder {
+    protected InternalContext ctx;
+
+    @Override
+    public void setContext(InternalContext context) {
+        this.ctx = context;
+    }
+
+    protected void safeSenderIfNecessary(Plaintext message) {
+        if (message.getId() == null) {
+            BitmessageAddress savedAddress = ctx.getAddressRepository().getAddress(message.getFrom().getAddress());
+            if (savedAddress == null) {
+                ctx.getAddressRepository().save(message.getFrom());
+            } else if (savedAddress.getPubkey() == null && message.getFrom().getPubkey() != null) {
+                savedAddress.setPubkey(message.getFrom().getPubkey());
+                ctx.getAddressRepository().save(savedAddress);
+            }
+        }
+    }
+
+    @Override
+    public Plaintext getMessage(Object id) {
+        if (id instanceof Long) {
+            return single(find("id=" + id));
+        } else {
+            throw new IllegalArgumentException("Long expected for ID");
+        }
+    }
+
+    @Override
+    public Plaintext getMessage(byte[] initialHash) {
+        return single(find("initial_hash=X'" + Strings.hex(initialHash) + "'"));
+    }
+
+    @Override
+    public Plaintext getMessageForAck(byte[] ackData) {
+        return single(find("ack_data=X'" + Strings.hex(ackData) + "' AND status='" + Plaintext.Status.SENT + "'"));
+    }
+
+    @Override
+    public List<Plaintext> findMessages(Label label) {
+        if (label == null) {
+            return find("id NOT IN (SELECT message_id FROM Message_Label)");
+        } else {
+            return find("id IN (SELECT message_id FROM Message_Label WHERE label_id=" + label.getId() + ")");
+        }
+    }
+
+    @Override
+    public List<Plaintext> findMessages(Plaintext.Status status, BitmessageAddress recipient) {
+        return find("status='" + status.name() + "' AND recipient='" + recipient.getAddress() + "'");
+    }
+
+    @Override
+    public List<Plaintext> findMessages(Plaintext.Status status) {
+        return find("status='" + status.name() + "'");
+    }
+
+    @Override
+    public List<Plaintext> findMessages(BitmessageAddress sender) {
+        return find("sender='" + sender.getAddress() + "'");
+    }
+
+    @Override
+    public List<Plaintext> findMessagesToResend() {
+        return find("status='" + Plaintext.Status.SENT.name() + "'" +
+                " AND next_try < " + UnixTime.now());
+    }
+
+    @Override
+    public List<Label> getLabels() {
+        return findLabels("1=1");
+    }
+
+    @Override
+    public List<Label> getLabels(Label.Type... types) {
+        return findLabels("type IN (" + join(types) + ")");
+    }
+
+    protected abstract List<Label> findLabels(String where);
+
+
+    protected <T> T single(Collection<T> collection) {
+        switch (collection.size()) {
+            case 0:
+                return null;
+            case 1:
+                return collection.iterator().next();
+            default:
+                throw new ApplicationException("This shouldn't happen, found " + collection.size() +
+                        " items, one or none was expected");
+        }
+    }
+
+    protected abstract List<Plaintext> find(String where);
+}

core/src/main/java/ch/dissem/bitmessage/ports/AddressRepository.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+
+import java.util.List;
+
+public interface AddressRepository {
+    BitmessageAddress findContact(byte[] ripeOrTag);
+
+    BitmessageAddress findIdentity(byte[] ripeOrTag);
+
+    /**
+     * @return all Bitmessage addresses that belong to this user, i.e. have a private key.
+     */
+    List<BitmessageAddress> getIdentities();
+
+    /**
+     * @return all subscribed chans.
+     */
+    List<BitmessageAddress> getChans();
+
+    List<BitmessageAddress> getSubscriptions();
+
+    List<BitmessageAddress> getSubscriptions(long broadcastVersion);
+
+    /**
+     * @return all Bitmessage addresses that have no private key or are chans.
+     */
+    List<BitmessageAddress> getContacts();
+
+    void save(BitmessageAddress address);
+
+    void remove(BitmessageAddress address);
+
+    BitmessageAddress getAddress(String address);
+}

core/src/main/java/ch/dissem/bitmessage/ports/Cryptography.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,260 +14,209 @@
  * limitations under the License. 
  */
 
-package ch.dissem.bitmessage.ports
+package ch.dissem.bitmessage.ports;
 
-import ch.dissem.bitmessage.InternalContext.Companion.NETWORK_EXTRA_BYTES
-import ch.dissem.bitmessage.InternalContext.Companion.NETWORK_NONCE_TRIALS_PER_BYTE
-import ch.dissem.bitmessage.entity.ObjectMessage
-import ch.dissem.bitmessage.entity.payload.Pubkey
-import ch.dissem.bitmessage.exception.InsufficientProofOfWorkException
-import java.math.BigInteger
-import java.security.MessageDigest
-import java.security.SecureRandom
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.entity.payload.Pubkey;
+import ch.dissem.bitmessage.exception.InsufficientProofOfWorkException;
+
+import java.io.IOException;
+import java.math.BigInteger;
+import java.security.MessageDigest;
+import java.security.SecureRandom;
 
 /**
- * Provides some methods to help with hashing and encryption. All randoms are created using [SecureRandom],
+ * Provides some methods to help with hashing and encryption. All randoms are created using {@link SecureRandom},
  * which should be secure enough.
  */
-interface Cryptography {
+public interface Cryptography {
     /**
-     * A helper method to calculate SHA-512 hashes. Please note that a new [MessageDigest] object is created at
+     * A helper method to calculate SHA-512 hashes. Please note that a new {@link MessageDigest} object is created at
      * each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in
      * success on the same thread.
-
+     *
      * @param data   to get hashed
-     * *
      * @param offset of the data to be hashed
-     * *
      * @param length of the data to be hashed
-     * *
      * @return SHA-512 hash of data within the given range
      */
-    fun sha512(data: ByteArray, offset: Int, length: Int): ByteArray
+    byte[] sha512(byte[] data, int offset, int length);
 
     /**
-     * A helper method to calculate SHA-512 hashes. Please note that a new [MessageDigest] object is created at
+     * A helper method to calculate SHA-512 hashes. Please note that a new {@link MessageDigest} object is created at
      * each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in
      * success on the same thread.
-
+     *
      * @param data to get hashed
-     * *
      * @return SHA-512 hash of data
      */
-    fun sha512(vararg data: ByteArray): ByteArray
+    byte[] sha512(byte[]... data);
 
     /**
-     * A helper method to calculate doubleSHA-512 hashes. Please note that a new [MessageDigest] object is created
+     * A helper method to calculate doubleSHA-512 hashes. Please note that a new {@link MessageDigest} object is created
      * at each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in
      * success on the same thread.
-
+     *
      * @param data to get hashed
-     * *
      * @return SHA-512 hash of data
      */
-    fun doubleSha512(vararg data: ByteArray): ByteArray
+    byte[] doubleSha512(byte[]... data);
 
     /**
      * A helper method to calculate double SHA-512 hashes. This method allows to only use a part of the available bytes
      * to use for the hash calculation.
-     *
-     *
-     * Please note that a new [MessageDigest] object is created at each call (to ensure thread safety), so you
+     * <p>
+     * Please note that a new {@link MessageDigest} object is created at each call (to ensure thread safety), so you
      * shouldn't use this if you need to do many hash calculations in short order on the same thread.
+     * </p>
      *
-
      * @param data   to get hashed
-     * *
      * @param length number of bytes to be taken into account
-     * *
      * @return SHA-512 hash of data
      */
-    fun doubleSha512(data: ByteArray, length: Int): ByteArray
+    byte[] doubleSha512(byte[] data, int length);
 
     /**
      * A helper method to calculate RIPEMD-160 hashes. Supplying multiple byte arrays has the same result as a
      * concatenation of all arrays, but might perform better.
-     *
-     *
-     * Please note that a new [MessageDigest] object is created at
+     * <p>
+     * Please note that a new {@link MessageDigest} object is created at
      * each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in short
      * order on the same thread.
+     * </p>
      *
-
      * @param data to get hashed
-     * *
      * @return RIPEMD-160 hash of data
      */
-    fun ripemd160(vararg data: ByteArray): ByteArray
+    byte[] ripemd160(byte[]... data);
 
     /**
      * A helper method to calculate double SHA-256 hashes. This method allows to only use a part of the available bytes
      * to use for the hash calculation.
-     *
-     *
-     * Please note that a new [MessageDigest] object is created at
+     * <p>
+     * Please note that a new {@link MessageDigest} object is created at
      * each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in short
      * order on the same thread.
+     * </p>
      *
-
      * @param data   to get hashed
-     * *
      * @param length number of bytes to be taken into account
-     * *
      * @return SHA-256 hash of data
      */
-    fun doubleSha256(data: ByteArray, length: Int): ByteArray
+    byte[] doubleSha256(byte[] data, int length);
 
     /**
      * A helper method to calculate SHA-1 hashes. Supplying multiple byte arrays has the same result as a
      * concatenation of all arrays, but might perform better.
-     *
-     *
-     * Please note that a new [MessageDigest] object is created at
+     * <p>
+     * Please note that a new {@link MessageDigest} object is created at
      * each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in short
      * order on the same thread.
+     * </p>
      *
-
      * @param data to get hashed
-     * *
      * @return SHA hash of data
      */
-    fun sha1(vararg data: ByteArray): ByteArray
+    byte[] sha1(byte[]... data);
 
     /**
      * @param length number of bytes to return
-     * *
      * @return an array of the given size containing random bytes
      */
-    fun randomBytes(length: Int): ByteArray
+    byte[] randomBytes(int length);
 
     /**
      * Calculates the proof of work. This might take a long time, depending on the hardware, message size and time to
      * live.
-
-     * @param objectMessage      to do the proof of work for
-     * *
+     *
+     * @param object             to do the proof of work for
      * @param nonceTrialsPerByte difficulty
-     * *
      * @param extraBytes         bytes to add to the object size (makes it more difficult to send small messages)
-     * *
      * @param callback           to handle nonce once it's calculated
      */
-    fun doProofOfWork(objectMessage: ObjectMessage, nonceTrialsPerByte: Long,
-                      extraBytes: Long, callback: ProofOfWorkEngine.Callback)
-
-    @JvmSynthetic
-    fun doProofOfWork(objectMessage: ObjectMessage, nonceTrialsPerByte: Long,
-                      extraBytes: Long, callback: (ByteArray, ByteArray) -> Unit) {
-        doProofOfWork(objectMessage, nonceTrialsPerByte, extraBytes, object : ProofOfWorkEngine.Callback {
-            override fun onNonceCalculated(initialHash: ByteArray, nonce: ByteArray) {
-                callback.invoke(initialHash, nonce)
-            }
-        })
-    }
+    void doProofOfWork(ObjectMessage object, long nonceTrialsPerByte,
+                       long extraBytes, ProofOfWorkEngine.Callback callback);
 
     /**
-     * @param objectMessage      to be checked
-     * *
+     * @param object             to be checked
      * @param nonceTrialsPerByte difficulty
-     * *
      * @param extraBytes         bytes to add to the object size
-     * *
      * @throws InsufficientProofOfWorkException if proof of work doesn't check out (makes it more difficult to send small messages)
      */
-    @Throws(InsufficientProofOfWorkException::class)
-    fun checkProofOfWork(objectMessage: ObjectMessage, nonceTrialsPerByte: Long, extraBytes: Long)
+    void checkProofOfWork(ObjectMessage object, long nonceTrialsPerByte, long extraBytes)
+            throws IOException;
 
-    fun getInitialHash(objectMessage: ObjectMessage): ByteArray
+    byte[] getInitialHash(ObjectMessage object);
 
-    fun getProofOfWorkTarget(objectMessage: ObjectMessage, nonceTrialsPerByte: Long = NETWORK_NONCE_TRIALS_PER_BYTE, extraBytes: Long = NETWORK_EXTRA_BYTES): ByteArray
+    byte[] getProofOfWorkTarget(ObjectMessage object, long nonceTrialsPerByte, long extraBytes);
 
     /**
      * Calculates the MAC for a message (data)
-
+     *
      * @param key_m the symmetric key used
-     * *
      * @param data  the message data to calculate the MAC for
-     * *
      * @return the MAC
      */
-    fun mac(key_m: ByteArray, data: ByteArray): ByteArray
+    byte[] mac(byte[] key_m, byte[] data);
 
     /**
      * @param encrypt if true, encrypts data, otherwise tries to decrypt it.
-     * *
      * @param data
-     * *
      * @param key_e
-     * *
      * @return
      */
-    fun crypt(encrypt: Boolean, data: ByteArray, key_e: ByteArray, initializationVector: ByteArray): ByteArray
+    byte[] crypt(boolean encrypt, byte[] data, byte[] key_e, byte[] initializationVector);
 
     /**
      * Create a new public key fom given private keys.
-
+     *
      * @param version              of the public key / address
-     * *
      * @param stream               of the address
-     * *
      * @param privateSigningKey    private key used for signing
-     * *
      * @param privateEncryptionKey private key used for encryption
-     * *
      * @param nonceTrialsPerByte   proof of work difficulty
-     * *
      * @param extraBytes           bytes to add for the proof of work (make it harder for small messages)
-     * *
      * @param features             of the address
-     * *
      * @return a public key object
      */
-    fun createPubkey(version: Long, stream: Long, privateSigningKey: ByteArray, privateEncryptionKey: ByteArray,
-                     nonceTrialsPerByte: Long, extraBytes: Long, vararg features: Pubkey.Feature): Pubkey
+    Pubkey createPubkey(long version, long stream, byte[] privateSigningKey, byte[] privateEncryptionKey,
+                        long nonceTrialsPerByte, long extraBytes, Pubkey.Feature... features);
 
     /**
      * @param privateKey private key as byte array
-     * *
      * @return a public key corresponding to the given private key
      */
-    fun createPublicKey(privateKey: ByteArray): ByteArray
+    byte[] createPublicKey(byte[] privateKey);
 
     /**
      * @param privateKey private key as byte array
-     * *
      * @return a big integer representation (unsigned) of the given bytes
      */
-    fun keyToBigInt(privateKey: ByteArray): BigInteger
+    BigInteger keyToBigInt(byte[] privateKey);
 
     /**
      * @param data      to check
-     * *
      * @param signature the signature of the message
-     * *
      * @param pubkey    the sender's public key
-     * *
      * @return true if the signature is valid, false otherwise
      */
-    fun isSignatureValid(data: ByteArray, signature: ByteArray, pubkey: Pubkey): Boolean
+    boolean isSignatureValid(byte[] data, byte[] signature, Pubkey pubkey);
 
     /**
      * Calculate the signature of data, using the given private key.
-
+     *
      * @param data       to be signed
-     * *
      * @param privateKey to be used for signing
-     * *
      * @return the signature
      */
-    fun getSignature(data: ByteArray, privateKey: ch.dissem.bitmessage.entity.valueobject.PrivateKey): ByteArray
+    byte[] getSignature(byte[] data, ch.dissem.bitmessage.entity.valueobject.PrivateKey privateKey);
 
     /**
      * @return a random number of type long
      */
-    fun randomNonce(): Long
+    long randomNonce();
 
-    fun multiply(k: ByteArray, r: ByteArray): ByteArray
+    byte[] multiply(byte[] k, byte[] r);
 
-    fun createPoint(x: ByteArray, y: ByteArray): ByteArray
+    byte[] createPoint(byte[] x, byte[] y);
 }

core/src/main/java/ch/dissem/bitmessage/ports/CustomCommandHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,15 +14,14 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.exception
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.entity.CustomMessage;
+import ch.dissem.bitmessage.entity.MessagePayload;
 
 /**
  * @author Christian Basler
  */
-class ApplicationException : RuntimeException {
-
-    constructor(cause: Throwable) : super(cause)
-
-    constructor(message: String) : super(message)
-
+public interface CustomCommandHandler {
+    MessagePayload handle(CustomMessage request);
 }

core/src/main/java/ch/dissem/bitmessage/ports/DefaultLabeler.java

@@ -0,0 +1,92 @@
+/*
+ * Copyright 2016 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.InternalContext;
+import ch.dissem.bitmessage.entity.Plaintext;
+import ch.dissem.bitmessage.entity.valueobject.Label;
+
+import static ch.dissem.bitmessage.entity.Plaintext.Status.*;
+
+public class DefaultLabeler implements Labeler, InternalContext.ContextHolder {
+    private InternalContext ctx;
+
+    @Override
+    public void setLabels(Plaintext msg) {
+        msg.setStatus(RECEIVED);
+        if (msg.getType() == Plaintext.Type.BROADCAST) {
+            msg.addLabels(ctx.getMessageRepository().getLabels(Label.Type.INBOX, Label.Type.BROADCAST, Label.Type.UNREAD));
+        } else {
+            msg.addLabels(ctx.getMessageRepository().getLabels(Label.Type.INBOX, Label.Type.UNREAD));
+        }
+    }
+
+    @Override
+    public void markAsDraft(Plaintext msg) {
+        msg.setStatus(DRAFT);
+        msg.addLabels(ctx.getMessageRepository().getLabels(Label.Type.DRAFT));
+    }
+
+    @Override
+    public void markAsSending(Plaintext msg) {
+        if (msg.getTo() != null && msg.getTo().getPubkey() == null) {
+            msg.setStatus(PUBKEY_REQUESTED);
+        } else {
+            msg.setStatus(DOING_PROOF_OF_WORK);
+        }
+        msg.removeLabel(Label.Type.DRAFT);
+        msg.addLabels(ctx.getMessageRepository().getLabels(Label.Type.OUTBOX));
+    }
+
+    @Override
+    public void markAsSent(Plaintext msg) {
+        msg.setStatus(SENT);
+        msg.removeLabel(Label.Type.OUTBOX);
+        msg.addLabels(ctx.getMessageRepository().getLabels(Label.Type.SENT));
+    }
+
+    @Override
+    public void markAsAcknowledged(Plaintext msg) {
+        msg.setStatus(SENT_ACKNOWLEDGED);
+    }
+
+    @Override
+    public void markAsRead(Plaintext msg) {
+        msg.removeLabel(Label.Type.UNREAD);
+    }
+
+    @Override
+    public void markAsUnread(Plaintext msg) {
+        msg.addLabels(ctx.getMessageRepository().getLabels(Label.Type.UNREAD));
+    }
+
+    @Override
+    public void delete(Plaintext msg) {
+        msg.getLabels().clear();
+        msg.addLabels(ctx.getMessageRepository().getLabels(Label.Type.TRASH));
+    }
+
+    @Override
+    public void archive(Plaintext msg) {
+        msg.getLabels().clear();
+    }
+
+    @Override
+    public void setContext(InternalContext ctx) {
+        this.ctx = ctx;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/ports/Inventory.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,42 +14,44 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.ports
+package ch.dissem.bitmessage.ports;
 
-import ch.dissem.bitmessage.entity.ObjectMessage
-import ch.dissem.bitmessage.entity.payload.ObjectType
-import ch.dissem.bitmessage.entity.valueobject.InventoryVector
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.entity.payload.ObjectType;
+import ch.dissem.bitmessage.entity.valueobject.InventoryVector;
+
+import java.util.List;
 
 /**
  * The Inventory stores and retrieves objects, cleans up outdated objects and can tell which objects are still missing.
  */
-interface Inventory {
+public interface Inventory {
     /**
      * Returns the IVs of all valid objects we have for the given streams
      */
-    fun getInventory(vararg streams: Long): List<InventoryVector>
+    List<InventoryVector> getInventory(long... streams);
 
     /**
      * Returns the IVs of all objects in the offer that we don't have already. Implementations are allowed to
      * ignore the streams parameter, but it must be set when calling this method.
      */
-    fun getMissing(offer: List<InventoryVector>, vararg streams: Long): List<InventoryVector>
+    List<InventoryVector> getMissing(List<InventoryVector> offer, long... streams);
 
-    fun getObject(vector: InventoryVector): ObjectMessage?
+    ObjectMessage getObject(InventoryVector vector);
 
     /**
      * This method is mainly used to search for public keys to newly added addresses or broadcasts from new
      * subscriptions.
      */
-    fun getObjects(stream: Long, version: Long, vararg types: ObjectType): List<ObjectMessage>
+    List<ObjectMessage> getObjects(long stream, long version, ObjectType... types);
 
-    fun storeObject(objectMessage: ObjectMessage)
+    void storeObject(ObjectMessage object);
 
-    operator fun contains(objectMessage: ObjectMessage): Boolean
+    boolean contains(ObjectMessage object);
 
     /**
      * Deletes all objects that expired 5 minutes ago or earlier
      * (so we don't accidentally request objects we just deleted)
      */
-    fun cleanup()
+    void cleanup();
 }

core/src/main/java/ch/dissem/bitmessage/ports/Labeler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2016 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,43 +14,44 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.ports
+package ch.dissem.bitmessage.ports;
 
-import ch.dissem.bitmessage.entity.Plaintext
+import ch.dissem.bitmessage.entity.Plaintext;
 
 /**
  * Defines and sets labels. Note that it should also update the status field of a message.
- * Generally it's highly advised to override the [DefaultLabeler] whenever possible,
+ * Generally it's highly advised to override the {@link DefaultLabeler} whenever possible,
  * instead of directly implementing the interface.
- *
+ * <p>
  * As the labeler gets called whenever the state of a message changes, it can also be used
  * as a listener.
+ * </p>
  */
-interface Labeler {
+public interface Labeler {
     /**
      * Sets the labels of a newly received message.
      *
      * @param msg an unlabeled message or broadcast
      */
-    fun setLabels(msg: Plaintext)
+    void setLabels(Plaintext msg);
 
-    fun markAsDraft(msg: Plaintext)
+    void markAsDraft(Plaintext msg);
 
     /**
-     * It is paramount that this methods marks the [Plaintext] object with status
-     * [Plaintext.Status.PUBKEY_REQUESTED] (see [DefaultLabeler])
+     * It is paramount that this methods marks the {@link Plaintext} object with status
+     * {@link Plaintext.Status#PUBKEY_REQUESTED} (see {@link DefaultLabeler})
      */
-    fun markAsSending(msg: Plaintext)
+    void markAsSending(Plaintext msg);
 
-    fun markAsSent(msg: Plaintext)
+    void markAsSent(Plaintext msg);
 
-    fun markAsAcknowledged(msg: Plaintext)
+    void markAsAcknowledged(Plaintext msg);
 
-    fun markAsRead(msg: Plaintext)
+    void markAsRead(Plaintext msg);
 
-    fun markAsUnread(msg: Plaintext)
+    void markAsUnread(Plaintext msg);
 
-    fun delete(msg: Plaintext)
+    void delete(Plaintext msg);
 
-    fun archive(msg: Plaintext)
+    void archive(Plaintext msg);
 }

core/src/main/java/ch/dissem/bitmessage/ports/MessageRepository.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.Plaintext;
+import ch.dissem.bitmessage.entity.Plaintext.Status;
+import ch.dissem.bitmessage.entity.valueobject.Label;
+
+import java.util.List;
+
+public interface MessageRepository {
+    List<Label> getLabels();
+
+    List<Label> getLabels(Label.Type... types);
+
+    int countUnread(Label label);
+
+    Plaintext getMessage(Object id);
+
+    Plaintext getMessage(byte[] initialHash);
+
+    Plaintext getMessageForAck(byte[] ackData);
+
+    List<Plaintext> findMessages(Label label);
+
+    List<Plaintext> findMessages(Status status);
+
+    List<Plaintext> findMessages(Status status, BitmessageAddress recipient);
+
+    List<Plaintext> findMessages(BitmessageAddress sender);
+
+    List<Plaintext> findMessagesToResend();
+
+    void save(Plaintext message);
+
+    void remove(Plaintext message);
+}

core/src/main/java/ch/dissem/bitmessage/ports/MultiThreadedPOWEngine.java

@@ -0,0 +1,128 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.utils.Bytes;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.*;
+
+import static ch.dissem.bitmessage.utils.Bytes.inc;
+import static ch.dissem.bitmessage.utils.ThreadFactoryBuilder.pool;
+
+/**
+ * A POW engine using all available CPU cores.
+ */
+public class MultiThreadedPOWEngine implements ProofOfWorkEngine {
+    private static final Logger LOG = LoggerFactory.getLogger(MultiThreadedPOWEngine.class);
+    private final ExecutorService waiterPool = Executors.newSingleThreadExecutor(pool("POW-waiter").daemon().build());
+    private final ExecutorService workerPool = Executors.newCachedThreadPool(pool("POW-worker").daemon().build());
+
+    /**
+     * This method will block until all pending nonce calculations are done, but not wait for its own calculation
+     * to finish.
+     * (This implementation becomes very inefficient if multiple nonce are calculated at the same time.)
+     *
+     * @param initialHash the SHA-512 hash of the object to send, sans nonce
+     * @param target      the target, representing an unsigned long
+     * @param callback    called with the calculated nonce as argument. The ProofOfWorkEngine implementation must make
+     */
+    @Override
+    public void calculateNonce(final byte[] initialHash, final byte[] target, final Callback callback) {
+        waiterPool.execute(new Runnable() {
+            @Override
+            public void run() {
+                long startTime = System.currentTimeMillis();
+
+                int cores = Runtime.getRuntime().availableProcessors();
+                if (cores > 255) cores = 255;
+                LOG.info("Doing POW using " + cores + " cores");
+                List<Worker> workers = new ArrayList<>(cores);
+                for (int i = 0; i < cores; i++) {
+                    Worker w = new Worker((byte) cores, i, initialHash, target);
+                    workers.add(w);
+                }
+                List<Future<byte[]>> futures = new ArrayList<>(cores);
+                for (Worker w : workers) {
+                    // Doing this in the previous loop might cause a ConcurrentModificationException in the worker
+                    // if a worker finds a nonce while new ones are still being added.
+                    futures.add(workerPool.submit(w));
+                }
+                try {
+                    while (!Thread.interrupted()) {
+                        for (Future<byte[]> future : futures) {
+                            if (future.isDone()) {
+                                callback.onNonceCalculated(initialHash, future.get());
+                                LOG.info("Nonce calculated in " + ((System.currentTimeMillis() - startTime) / 1000) + " seconds");
+                                for (Future<byte[]> f : futures) {
+                                    f.cancel(true);
+                                }
+                                return;
+                            }
+                        }
+                        Thread.sleep(100);
+                    }
+                    LOG.error("POW waiter thread interrupted - this should not happen!");
+                } catch (ExecutionException e) {
+                    LOG.error(e.getMessage(), e);
+                } catch (InterruptedException e) {
+                    LOG.error("POW waiter thread interrupted - this should not happen!", e);
+                }
+            }
+        });
+    }
+
+    private class Worker implements Callable<byte[]> {
+        private final byte numberOfCores;
+        private final byte[] initialHash;
+        private final byte[] target;
+        private final MessageDigest mda;
+        private final byte[] nonce = new byte[8];
+
+        Worker(byte numberOfCores, int core, byte[] initialHash, byte[] target) {
+            this.numberOfCores = numberOfCores;
+            this.initialHash = initialHash;
+            this.target = target;
+            this.nonce[7] = (byte) core;
+            try {
+                mda = MessageDigest.getInstance("SHA-512");
+            } catch (NoSuchAlgorithmException e) {
+                LOG.error(e.getMessage(), e);
+                throw new ApplicationException(e);
+            }
+        }
+
+        @Override
+        public byte[] call() throws Exception {
+            do {
+                inc(nonce, numberOfCores);
+                mda.update(nonce);
+                mda.update(initialHash);
+                if (!Bytes.lt(target, mda.digest(mda.digest()), 8)) {
+                    return nonce;
+                }
+            } while (!Thread.interrupted());
+            return null;
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/ports/NetworkHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,73 +14,73 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.ports
+package ch.dissem.bitmessage.ports;
 
-import ch.dissem.bitmessage.entity.CustomMessage
-import ch.dissem.bitmessage.entity.ObjectMessage
-import ch.dissem.bitmessage.entity.valueobject.InventoryVector
-import ch.dissem.bitmessage.utils.Property
+import ch.dissem.bitmessage.entity.CustomMessage;
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.entity.valueobject.InventoryVector;
+import ch.dissem.bitmessage.utils.Property;
 
-import java.io.IOException
-import java.net.InetAddress
-import java.util.concurrent.Future
+import java.io.IOException;
+import java.net.InetAddress;
+import java.util.Collection;
+import java.util.concurrent.Future;
 
 /**
  * Handles incoming messages
  */
-interface NetworkHandler {
+public interface NetworkHandler {
+    int NETWORK_MAGIC_NUMBER = 8;
+    int HEADER_SIZE = 24;
+    int MAX_PAYLOAD_SIZE = 1600003;
+    int MAX_MESSAGE_SIZE = HEADER_SIZE + MAX_PAYLOAD_SIZE;
 
     /**
      * Connects to the trusted host, fetches and offers new messages and disconnects afterwards.
-     *
-     *
+     * <p>
      * An implementation should disconnect if either the timeout is reached or the returned thread is interrupted.
-     *
+     * </p>
      */
-    fun synchronize(server: InetAddress, port: Int, timeoutInSeconds: Long): Future<*>
+    Future<?> synchronize(InetAddress server, int port, long timeoutInSeconds);
 
     /**
      * Send a custom message to a specific node (that should implement handling for this message type) and returns
-     * the response, which in turn is expected to be a [CustomMessage].
-
+     * the response, which in turn is expected to be a {@link CustomMessage}.
+     *
      * @param server  the node's address
-     * *
      * @param port    the node's port
-     * *
      * @param request the request
-     * *
      * @return the response
      */
-    fun send(server: InetAddress, port: Int, request: CustomMessage): CustomMessage
+    CustomMessage send(InetAddress server, int port, CustomMessage request);
 
     /**
      * Start a full network node, accepting incoming connections and relaying objects.
      */
-    fun start()
+    void start();
 
     /**
      * Stop the full network node.
      */
-    fun stop()
+    void stop();
 
     /**
      * Offer new objects to up to 8 random nodes.
      */
-    fun offer(iv: InventoryVector)
+    void offer(InventoryVector iv);
 
     /**
      * Request each of those objects from a node that knows of the requested object.
-
+     *
      * @param inventoryVectors of the objects to be requested
      */
-    fun request(inventoryVectors: MutableCollection<InventoryVector>)
+    void request(Collection<InventoryVector> inventoryVectors);
 
-    fun getNetworkStatus(): Property
+    Property getNetworkStatus();
 
-    val isRunning: Boolean
+    boolean isRunning();
 
     interface MessageListener {
-        @Throws(IOException::class)
-        fun receive(objectMessage: ObjectMessage)
+        void receive(ObjectMessage object) throws IOException;
     }
 }

core/src/main/java/ch/dissem/bitmessage/ports/NodeRegistry.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.entity.valueobject.NetworkAddress;
+
+import java.util.List;
+
+/**
+ * Stores and provides known peers.
+ */
+public interface NodeRegistry {
+    List<NetworkAddress> getKnownAddresses(int limit, long... streams);
+
+    void offerAddresses(List<NetworkAddress> addresses);
+}

core/src/main/java/ch/dissem/bitmessage/ports/NodeRegistryHelper.java

@@ -0,0 +1,54 @@
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.entity.valueobject.NetworkAddress;
+import ch.dissem.bitmessage.exception.ApplicationException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.InetAddress;
+import java.util.*;
+
+/**
+ * Helper class to kick start node registries.
+ */
+public class NodeRegistryHelper {
+    private static final Logger LOG = LoggerFactory.getLogger(NodeRegistryHelper.class);
+
+    public static Map<Long, Set<NetworkAddress>> loadStableNodes() {
+        try (InputStream in = NodeRegistryHelper.class.getClassLoader().getResourceAsStream("nodes.txt")) {
+            Scanner scanner = new Scanner(in);
+            long stream = 0;
+            Map<Long, Set<NetworkAddress>> result = new HashMap<>();
+            Set<NetworkAddress> streamSet = null;
+            while (scanner.hasNext()) {
+                try {
+                    String line = scanner.nextLine().trim();
+                    if (line.startsWith("[stream")) {
+                        stream = Long.parseLong(line.substring(8, line.lastIndexOf(']')));
+                        streamSet = new HashSet<>();
+                        result.put(stream, streamSet);
+                    } else if (streamSet != null && !line.isEmpty() && !line.startsWith("#")) {
+                        int portIndex = line.lastIndexOf(':');
+                        InetAddress[] inetAddresses = InetAddress.getAllByName(line.substring(0, portIndex));
+                        int port = Integer.valueOf(line.substring(portIndex + 1));
+                        for (InetAddress inetAddress : inetAddresses) {
+                            streamSet.add(new NetworkAddress.Builder().ip(inetAddress).port(port).stream(stream).build());
+                        }
+                    }
+                } catch (IOException e) {
+                    LOG.warn(e.getMessage(), e);
+                }
+            }
+            if (LOG.isDebugEnabled()) {
+                for (Map.Entry<Long, Set<NetworkAddress>> e : result.entrySet()) {
+                    LOG.debug("Stream " + e.getKey() + ": loaded " + e.getValue().size() + " bootstrap nodes.");
+                }
+            }
+            return result;
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/ports/ProofOfWorkEngine.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports;
+
+/**
+ * Does the proof of work necessary to send an object.
+ */
+public interface ProofOfWorkEngine {
+    /**
+     * Returns a nonce, such that the first 8 bytes from sha512(sha512(nonce||initialHash)) represent a unsigned long
+     * smaller than target.
+     *
+     * @param initialHash the SHA-512 hash of the object to send, sans nonce
+     * @param target      the target, representing an unsigned long
+     * @param callback    called with the calculated nonce as argument. The ProofOfWorkEngine implementation must make
+     *                    sure this is only called once.
+     */
+    void calculateNonce(byte[] initialHash, byte[] target, Callback callback);
+
+    interface Callback {
+        /**
+         * @param nonce 8 bytes nonce
+         */
+        void onNonceCalculated(byte[] initialHash, byte[] nonce);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/ports/ProofOfWorkRepository.java

@@ -0,0 +1,45 @@
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.entity.Plaintext;
+
+import java.util.List;
+
+/**
+ * Objects that proof of work is currently being done for.
+ *
+ * @author Christian Basler
+ */
+public interface ProofOfWorkRepository {
+    Item getItem(byte[] initialHash);
+
+    List<byte[]> getItems();
+
+    void putObject(ObjectMessage object, long nonceTrialsPerByte, long extraBytes);
+
+    void putObject(Item item);
+
+    void removeObject(byte[] initialHash);
+
+    class Item {
+        public final ObjectMessage object;
+        public final long nonceTrialsPerByte;
+        public final long extraBytes;
+
+        // Needed for ACK POW calculation
+        public final Long expirationTime;
+        public final Plaintext message;
+
+        public Item(ObjectMessage object, long nonceTrialsPerByte, long extraBytes) {
+            this(object, nonceTrialsPerByte, extraBytes, 0, null);
+        }
+
+        public Item(ObjectMessage object, long nonceTrialsPerByte, long extraBytes, long expirationTime, Plaintext message) {
+            this.object = object;
+            this.nonceTrialsPerByte = nonceTrialsPerByte;
+            this.extraBytes = extraBytes;
+            this.expirationTime = expirationTime;
+            this.message = message;
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/ports/SimplePOWEngine.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.ports;
+
+import ch.dissem.bitmessage.exception.ApplicationException;
+import ch.dissem.bitmessage.utils.Bytes;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+import static ch.dissem.bitmessage.utils.Bytes.inc;
+
+/**
+ * You should really use the MultiThreadedPOWEngine, but this one might help you grok the other one.
+ * <p>
+ * <strong>Warning:</strong> implementations probably depend on POW being asynchronous, that's
+ * another reason not to use this one.
+ * </p>
+ */
+public class SimplePOWEngine implements ProofOfWorkEngine {
+    @Override
+    public void calculateNonce(byte[] initialHash, byte[] target, Callback callback) {
+        try {
+            MessageDigest mda = MessageDigest.getInstance("SHA-512");
+            byte[] nonce = new byte[8];
+            do {
+                inc(nonce);
+                mda.update(nonce);
+                mda.update(initialHash);
+            } while (Bytes.lt(target, mda.digest(mda.digest()), 8));
+            callback.onNonceCalculated(initialHash, nonce);
+        } catch (NoSuchAlgorithmException e) {
+            throw new ApplicationException(e);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/AccessCounter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,50 +14,48 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.utils
+package ch.dissem.bitmessage.utils;
 
 /**
  * Intended to count the bytes read or written during (de-)serialization.
  */
-class AccessCounter {
-    private var count: Int = 0
-
-    /**
-     * Increases the counter by one.
-     */
-    private fun inc() {
-        count++
-    }
-
-    /**
-     * Increases the counter by length.
-     */
-    private fun inc(length: Int) {
-        count += length
-    }
-
-    fun length(): Int {
-        return count
-    }
-
-    override fun toString(): String {
-        return count.toString()
-    }
-
-    companion object {
+public class AccessCounter {
+    private int count;
 
     /**
      * Increases the counter by one, if not null.
      */
-        @JvmStatic fun inc(counter: AccessCounter?) {
-            counter?.inc()
+    public static void inc(AccessCounter counter) {
+        if (counter != null) counter.inc();
     }
 
     /**
      * Increases the counter by length, if not null.
      */
-        @JvmStatic fun inc(counter: AccessCounter?, length: Int) {
-            counter?.inc(length)
-        }
+    public static void inc(AccessCounter counter, int length) {
+        if (counter != null) counter.inc(length);
+    }
+
+    /**
+     * Increases the counter by one.
+     */
+    private void inc() {
+        count++;
+    }
+
+    /**
+     * Increases the counter by length.
+     */
+    private void inc(int length) {
+        count += length;
+    }
+
+    public int length() {
+        return count;
+    }
+
+    @Override
+    public String toString() {
+        return String.valueOf(count);
     }
 }

core/src/main/java/ch/dissem/bitmessage/utils/Base58.java

@@ -0,0 +1,168 @@
+/*
+ * Copyright 2011 Google Inc.
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+import ch.dissem.bitmessage.exception.AddressFormatException;
+import ch.dissem.bitmessage.exception.ApplicationException;
+
+import java.io.UnsupportedEncodingException;
+
+import static java.util.Arrays.copyOfRange;
+
+/**
+ * Base58 encoder and decoder.
+ *
+ * @author Christian Basler: I removed some dependencies to the BitcoinJ code so it can be used here more easily.
+ */
+public class Base58 {
+    private static final int[] INDEXES = new int[128];
+    private static final char[] ALPHABET = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz".toCharArray();
+
+    static {
+        for (int i = 0; i < INDEXES.length; i++) {
+            INDEXES[i] = -1;
+        }
+        for (int i = 0; i < ALPHABET.length; i++) {
+            INDEXES[ALPHABET[i]] = i;
+        }
+    }
+
+    /**
+     * Encodes the given bytes in base58. No checksum is appended.
+     *
+     * @param data to encode
+     * @return base58 encoded input
+     */
+    public static String encode(byte[] data) {
+        if (data.length == 0) {
+            return "";
+        }
+        final byte[] bytes = copyOfRange(data, 0, data.length);
+        // Count leading zeroes.
+        int zeroCount = 0;
+        while (zeroCount < bytes.length && bytes[zeroCount] == 0) {
+            ++zeroCount;
+        }
+        // The actual encoding.
+        byte[] temp = new byte[bytes.length * 2];
+        int j = temp.length;
+
+        int startAt = zeroCount;
+        while (startAt < bytes.length) {
+            byte mod = divmod58(bytes, startAt);
+            if (bytes[startAt] == 0) {
+                ++startAt;
+            }
+            temp[--j] = (byte) ALPHABET[mod];
+        }
+
+        // Strip extra '1' if there are some after decoding.
+        while (j < temp.length && temp[j] == ALPHABET[0]) {
+            ++j;
+        }
+        // Add as many leading '1' as there were leading zeros.
+        while (--zeroCount >= 0) {
+            temp[--j] = (byte) ALPHABET[0];
+        }
+
+        byte[] output = copyOfRange(temp, j, temp.length);
+        try {
+            return new String(output, "US-ASCII");
+        } catch (UnsupportedEncodingException e) {
+            throw new ApplicationException(e);  // Cannot happen.
+        }
+    }
+
+    public static byte[] decode(String input) throws AddressFormatException {
+        if (input.length() == 0) {
+            return new byte[0];
+        }
+        byte[] input58 = new byte[input.length()];
+        // Transform the String to a base58 byte sequence
+        for (int i = 0; i < input.length(); ++i) {
+            char c = input.charAt(i);
+
+            int digit58 = -1;
+            if (c < 128) {
+                digit58 = INDEXES[c];
+            }
+            if (digit58 < 0) {
+                throw new AddressFormatException("Illegal character " + c + " at " + i);
+            }
+
+            input58[i] = (byte) digit58;
+        }
+        // Count leading zeroes
+        int zeroCount = 0;
+        while (zeroCount < input58.length && input58[zeroCount] == 0) {
+            ++zeroCount;
+        }
+        // The encoding
+        byte[] temp = new byte[input.length()];
+        int j = temp.length;
+
+        int startAt = zeroCount;
+        while (startAt < input58.length) {
+            byte mod = divmod256(input58, startAt);
+            if (input58[startAt] == 0) {
+                ++startAt;
+            }
+
+            temp[--j] = mod;
+        }
+        // Do no add extra leading zeroes, move j to first non null byte.
+        while (j < temp.length && temp[j] == 0) {
+            ++j;
+        }
+        return copyOfRange(temp, j - zeroCount, temp.length);
+    }
+
+    //
+    // number -> number / 58, returns number % 58
+    //
+    private static byte divmod58(byte[] number, int startAt) {
+        int remainder = 0;
+        for (int i = startAt; i < number.length; i++) {
+            int digit256 = (int) number[i] & 0xFF;
+            int temp = remainder * 256 + digit256;
+
+            number[i] = (byte) (temp / 58);
+
+            remainder = temp % 58;
+        }
+
+        return (byte) remainder;
+    }
+
+    //
+    // number -> number / 256, returns number % 256
+    //
+    private static byte divmod256(byte[] number58, int startAt) {
+        int remainder = 0;
+        for (int i = startAt; i < number58.length; i++) {
+            int digit58 = (int) number58[i] & 0xFF;
+            int temp = remainder * 58 + digit58;
+
+            number58[i] = (byte) (temp / 256);
+
+            remainder = temp % 256;
+        }
+
+        return (byte) remainder;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/Bytes.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,10 +21,6 @@ package ch.dissem.bitmessage.utils;
  * This is one part due to the fact that Java doesn't support unsigned numbers, and another
  * part so we don't have to convert between byte arrays and numbers in time critical
  * situations.
- * <p>
- * Note: This class can't yet be ported to Kotlin, as with Kotlin byte + byte = int, which
- * would be rather inefficient in our case.
- * </p>
  */
 public class Bytes {
     public static final byte BYTE_0x80 = (byte) 0x80;

core/src/main/java/ch/dissem/bitmessage/utils/CallbackWaiter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,32 +14,35 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.utils
+package ch.dissem.bitmessage.utils;
 
 /**
  * Waits for a value within a callback method to be set.
  */
-class CallbackWaiter<T> {
-    private val startTime = System.currentTimeMillis()
-    @Volatile private var isSet: Boolean = false
-    private var _value: T? = null
-    var time: Long = 0
-        private set
+public class CallbackWaiter<T> {
+    private final long startTime = System.currentTimeMillis();
+    private volatile boolean isSet;
+    private T value;
+    private long time;
 
-    fun setValue(value: T?) {
+    public void setValue(T value) {
         synchronized (this) {
-            this.time = System.currentTimeMillis() - startTime
-            this._value = value
-            this.isSet = true
+            this.time = System.currentTimeMillis() - startTime;
+            this.value = value;
+            this.isSet = true;
         }
     }
 
-    fun waitForValue(): T? {
+    public T waitForValue() throws InterruptedException {
         while (!isSet) {
-            Thread.sleep(100)
+            Thread.sleep(100);
         }
         synchronized (this) {
-            return _value
+            return value;
         }
     }
+
+    public long getTime() {
+        return time;
+    }
 }

core/src/main/java/ch/dissem/bitmessage/utils/Collections.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Random;
+
+public class Collections {
+    private final static Random RANDOM = new Random();
+
+    /**
+     * @param count      the number of elements to return (if possible)
+     * @param collection the collection to take samples from
+     * @return a random subset of the given collection, or a copy of the collection if it's not larger than count. The
+     * result is by no means securely random, but should be random enough so not the same objects get selected over
+     * and over again.
+     */
+    public static <T> List<T> selectRandom(int count, Collection<T> collection) {
+        ArrayList<T> result = new ArrayList<>(count);
+        if (collection.size() <= count) {
+            result.addAll(collection);
+        } else {
+            double collectionRest = collection.size();
+            double resultRest = count;
+            int skipMax = (int) Math.ceil(collectionRest / resultRest);
+            int skip = RANDOM.nextInt(skipMax);
+            for (T item : collection) {
+                collectionRest--;
+                if (skip > 0) {
+                    skip--;
+                } else {
+                    result.add(item);
+                    resultRest--;
+                    if (resultRest == 0) {
+                        break;
+                    }
+                    skipMax = (int) Math.ceil(collectionRest / resultRest);
+                    skip = RANDOM.nextInt(skipMax);
+                }
+            }
+        }
+        return result;
+    }
+
+    public static <T> T selectRandom(Collection<T> collection) {
+        int index = RANDOM.nextInt(collection.size());
+        for (T item : collection) {
+            if (index == 0) {
+                return item;
+            }
+            index--;
+        }
+        throw new IllegalArgumentException("Empty collection? Size: " + collection.size());
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/DebugUtils.java

@@ -0,0 +1,48 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.Map;
+
+public class DebugUtils {
+    private final static Logger LOG = LoggerFactory.getLogger(DebugUtils.class);
+
+    public static void saveToFile(ObjectMessage objectMessage) {
+        try {
+            File f = new File(System.getProperty("user.home") + "/jabit.error/" + objectMessage.getInventoryVector() + ".inv");
+            f.createNewFile();
+            objectMessage.write(new FileOutputStream(f));
+        } catch (IOException e) {
+            LOG.debug(e.getMessage(), e);
+        }
+    }
+
+    public static <K> void inc(Map<K, Integer> map, K key) {
+        if (map.containsKey(key)) {
+            map.put(key, map.get(key) + 1);
+        } else {
+            map.put(key, 1);
+        }
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/Decode.java

@@ -0,0 +1,152 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+
+import static ch.dissem.bitmessage.utils.AccessCounter.inc;
+
+/**
+ * This class handles decoding simple types from byte stream, according to
+ * https://bitmessage.org/wiki/Protocol_specification#Common_structures
+ */
+public class Decode {
+    public static byte[] shortVarBytes(InputStream in, AccessCounter counter) throws IOException {
+        int length = uint16(in, counter);
+        return bytes(in, length, counter);
+    }
+
+    public static byte[] varBytes(InputStream in) throws IOException {
+        return varBytes(in, null);
+    }
+
+    public static byte[] varBytes(InputStream in, AccessCounter counter) throws IOException {
+        int length = (int) varInt(in, counter);
+        return bytes(in, length, counter);
+    }
+
+    public static byte[] bytes(InputStream in, int count) throws IOException {
+        return bytes(in, count, null);
+    }
+
+    public static byte[] bytes(InputStream in, int count, AccessCounter counter) throws IOException {
+        byte[] result = new byte[count];
+        int off = 0;
+        while (off < count) {
+            int read = in.read(result, off, count - off);
+            if (read < 0) {
+                throw new IOException("Unexpected end of stream, wanted to read " + count + " bytes but only got " + off);
+            }
+            off += read;
+        }
+        inc(counter, count);
+        return result;
+    }
+
+    public static long[] varIntList(InputStream in) throws IOException {
+        int length = (int) varInt(in);
+        long[] result = new long[length];
+
+        for (int i = 0; i < length; i++) {
+            result[i] = varInt(in);
+        }
+        return result;
+    }
+
+    public static long varInt(InputStream in) throws IOException {
+        return varInt(in, null);
+    }
+
+    public static long varInt(InputStream in, AccessCounter counter) throws IOException {
+        int first = in.read();
+        inc(counter);
+        switch (first) {
+            case 0xfd:
+                return uint16(in, counter);
+            case 0xfe:
+                return uint32(in, counter);
+            case 0xff:
+                return int64(in, counter);
+            default:
+                return first;
+        }
+    }
+
+    public static int uint8(InputStream in) throws IOException {
+        return in.read();
+    }
+
+    public static int uint16(InputStream in) throws IOException {
+        return uint16(in, null);
+    }
+
+    public static int uint16(InputStream in, AccessCounter counter) throws IOException {
+        inc(counter, 2);
+        return in.read() << 8 | in.read();
+    }
+
+    public static long uint32(InputStream in) throws IOException {
+        return uint32(in, null);
+    }
+
+    public static long uint32(InputStream in, AccessCounter counter) throws IOException {
+        inc(counter, 4);
+        return in.read() << 24 | in.read() << 16 | in.read() << 8 | in.read();
+    }
+
+    public static long uint32(ByteBuffer in) {
+        return u(in.get()) << 24 | u(in.get()) << 16 | u(in.get()) << 8 | u(in.get());
+    }
+
+    public static int int32(InputStream in) throws IOException {
+        return int32(in, null);
+    }
+
+    public static int int32(InputStream in, AccessCounter counter) throws IOException {
+        inc(counter, 4);
+        return ByteBuffer.wrap(bytes(in, 4)).getInt();
+    }
+
+    public static long int64(InputStream in) throws IOException {
+        return int64(in, null);
+    }
+
+    public static long int64(InputStream in, AccessCounter counter) throws IOException {
+        inc(counter, 8);
+        return ByteBuffer.wrap(bytes(in, 8)).getLong();
+    }
+
+    public static String varString(InputStream in) throws IOException {
+        return varString(in, null);
+    }
+
+    public static String varString(InputStream in, AccessCounter counter) throws IOException {
+        int length = (int) varInt(in, counter);
+        // FIXME: technically, it says the length in characters, but I think this one might be correct
+        // otherwise it will get complicated, as we'll need to read UTF-8 char by char...
+        return new String(bytes(in, length, counter), "utf-8");
+    }
+
+    /**
+     * Returns the given byte as if it were unsigned.
+     */
+    private static int u(byte b) {
+        return b & 0xFF;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/Encode.java

@@ -0,0 +1,207 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+import ch.dissem.bitmessage.entity.Streamable;
+import ch.dissem.bitmessage.exception.ApplicationException;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.UnsupportedEncodingException;
+import java.nio.Buffer;
+import java.nio.ByteBuffer;
+
+import static ch.dissem.bitmessage.utils.AccessCounter.inc;
+
+/**
+ * This class handles encoding simple types from byte stream, according to
+ * https://bitmessage.org/wiki/Protocol_specification#Common_structures
+ */
+public class Encode {
+    public static void varIntList(long[] values, OutputStream stream) throws IOException {
+        varInt(values.length, stream);
+        for (long value : values) {
+            varInt(value, stream);
+        }
+    }
+
+    public static void varIntList(long[] values, ByteBuffer buffer) {
+        varInt(values.length, buffer);
+        for (long value : values) {
+            varInt(value, buffer);
+        }
+    }
+
+    public static void varInt(long value, OutputStream stream) throws IOException {
+        varInt(value, stream, null);
+    }
+
+    public static void varInt(long value, ByteBuffer buffer) {
+        if (value < 0) {
+            // This is due to the fact that Java doesn't really support unsigned values.
+            // Please be aware that this might be an error due to a smaller negative value being cast to long.
+            // Normally, negative values shouldn't occur within the protocol, and longs large enough for being
+            // recognized as negatives aren't realistic.
+            buffer.put((byte) 0xff);
+            buffer.putLong(value);
+        } else if (value < 0xfd) {
+            buffer.put((byte) value);
+        } else if (value <= 0xffffL) {
+            buffer.put((byte) 0xfd);
+            buffer.putShort((short) value);
+        } else if (value <= 0xffffffffL) {
+            buffer.put((byte) 0xfe);
+            buffer.putInt((int) value);
+        } else {
+            buffer.put((byte) 0xff);
+            buffer.putLong(value);
+        }
+    }
+
+    public static byte[] varInt(long value) {
+        ByteBuffer buffer = ByteBuffer.allocate(9);
+        varInt(value, buffer);
+        buffer.flip();
+        return Bytes.truncate(buffer.array(), buffer.limit());
+    }
+
+    public static void varInt(long value, OutputStream stream, AccessCounter counter) throws IOException {
+        ByteBuffer buffer = ByteBuffer.allocate(9);
+        varInt(value, buffer);
+        buffer.flip();
+        stream.write(buffer.array(), 0, buffer.limit());
+        inc(counter, buffer.limit());
+    }
+
+    public static void int8(long value, OutputStream stream) throws IOException {
+        int8(value, stream, null);
+    }
+
+    public static void int8(long value, OutputStream stream, AccessCounter counter) throws IOException {
+        stream.write((int) value);
+        inc(counter);
+    }
+
+    public static void int16(long value, OutputStream stream) throws IOException {
+        int16(value, stream, null);
+    }
+
+    public static void int16(long value, OutputStream stream, AccessCounter counter) throws IOException {
+        stream.write(ByteBuffer.allocate(2).putShort((short) value).array());
+        inc(counter, 2);
+    }
+
+    public static void int16(long value, ByteBuffer buffer) {
+        buffer.putShort((short) value);
+    }
+
+    public static void int32(long value, OutputStream stream) throws IOException {
+        int32(value, stream, null);
+    }
+
+    public static void int32(long value, OutputStream stream, AccessCounter counter) throws IOException {
+        stream.write(ByteBuffer.allocate(4).putInt((int) value).array());
+        inc(counter, 4);
+    }
+
+    public static void int32(long value, ByteBuffer buffer) {
+        buffer.putInt((int) value);
+    }
+
+    public static void int64(long value, OutputStream stream) throws IOException {
+        int64(value, stream, null);
+    }
+
+    public static void int64(long value, OutputStream stream, AccessCounter counter) throws IOException {
+        stream.write(ByteBuffer.allocate(8).putLong(value).array());
+        inc(counter, 8);
+    }
+
+    public static void int64(long value, ByteBuffer buffer) {
+        buffer.putLong(value);
+    }
+
+    public static void varString(String value, OutputStream out) throws IOException {
+        byte[] bytes = value.getBytes("utf-8");
+        // Technically, it says the length in characters, but I think this one might be correct.
+        // It doesn't really matter, as only ASCII characters are being used.
+        // see also Decode#varString()
+        varInt(bytes.length, out);
+        out.write(bytes);
+    }
+
+    public static void varString(String value, ByteBuffer buffer) {
+        try {
+            byte[] bytes = value.getBytes("utf-8");
+            // Technically, it says the length in characters, but I think this one might be correct.
+            // It doesn't really matter, as only ASCII characters are being used.
+            // see also Decode#varString()
+            buffer.put(varInt(bytes.length));
+            buffer.put(bytes);
+        } catch (UnsupportedEncodingException e) {
+            throw new ApplicationException(e);
+        }
+    }
+
+    public static void varBytes(byte[] data, OutputStream out) throws IOException {
+        varInt(data.length, out);
+        out.write(data);
+    }
+
+    public static void varBytes(byte[] data, ByteBuffer buffer) {
+        varInt(data.length, buffer);
+        buffer.put(data);
+    }
+
+    /**
+     * Serializes a {@link Streamable} object and returns the byte array.
+     *
+     * @param streamable the object to be serialized
+     * @return an array of bytes representing the given streamable object.
+     */
+    public static byte[] bytes(Streamable streamable) {
+        if (streamable == null) return null;
+
+        ByteArrayOutputStream stream = new ByteArrayOutputStream();
+        try {
+            streamable.write(stream);
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+        return stream.toByteArray();
+    }
+
+    /**
+     * @param streamable the object to be serialized
+     * @param padding    the result will be padded such that its length is a multiple of <em>padding</em>
+     * @return the bytes of the given {@link Streamable} object, 0-padded such that the final length is x*padding.
+     */
+    public static byte[] bytes(Streamable streamable, int padding) {
+        ByteArrayOutputStream stream = new ByteArrayOutputStream();
+        try {
+            streamable.write(stream);
+        } catch (IOException e) {
+            throw new ApplicationException(e);
+        }
+        int offset = padding - stream.size() % padding;
+        int length = stream.size() + offset;
+        byte[] result = new byte[length];
+        stream.write(result, offset, stream.size());
+        return result;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/Numbers.java

@@ -0,0 +1,10 @@
+package ch.dissem.bitmessage.utils;
+
+/**
+ * @author Christian Basler
+ */
+public class Numbers {
+    public static long max(long a, long b) {
+        return a > b ? a : b;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/Points.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+import java.util.Arrays;
+
+/**
+ * Created by chris on 20.07.15.
+ */
+public class Points {
+    public static byte[] getX(byte[] P) {
+        return Arrays.copyOfRange(P, 1, ((P.length - 1) / 2) + 1);
+    }
+
+    public static byte[] getY(byte[] P) {
+        return Arrays.copyOfRange(P, ((P.length - 1) / 2) + 1, P.length);
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/Property.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+import java.util.Arrays;
+import java.util.Objects;
+
+/**
+ * Some property that has a name, a value and/or other properties. This can be used for any purpose, but is for now
+ * used to contain different status information. It is by default displayed in some JSON inspired human readable
+ * notation, but you might only want to rely on the 'human readable' part.
+ * <p>
+ * If you need a real JSON representation, please add a method <code>toJson()</code>.
+ * </p>
+ */
+public class Property {
+    private String name;
+    private Object value;
+    private Property[] properties;
+
+    public Property(String name, Object value, Property... properties) {
+        this.name = name;
+        this.value = value;
+        this.properties = properties;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public Object getValue() {
+        return value;
+    }
+
+    /**
+     * Returns the property if available or <code>null</code> otherwise.
+     * Subproperties can be requested by submitting the sequence of properties.
+     */
+    public Property getProperty(String... name) {
+        if (name == null || name.length == 0) return null;
+
+        for (Property p : properties) {
+            if (Objects.equals(name[0], p.name)) {
+                if (name.length == 1)
+                    return p;
+                else
+                    return p.getProperty(Arrays.copyOfRange(name, 1, name.length));
+            }
+        }
+        return null;
+    }
+
+    public Property[] getProperties() {
+        return properties;
+    }
+
+    @Override
+    public String toString() {
+        return toString("");
+    }
+
+    private String toString(String indentation) {
+        StringBuilder result = new StringBuilder();
+        result.append(indentation).append(name).append(": ");
+        if (value != null || properties.length == 0) {
+            result.append(value);
+        }
+        if (properties.length > 0) {
+            result.append("{\n");
+            for (Property property : properties) {
+                result.append(property.toString(indentation + "  ")).append('\n');
+            }
+            result.append(indentation).append("}");
+        }
+        return result.toString();
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/Singleton.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,23 +14,23 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.utils
+package ch.dissem.bitmessage.utils;
 
-import ch.dissem.bitmessage.ports.Cryptography
-import kotlin.properties.Delegates
+import ch.dissem.bitmessage.ports.Cryptography;
 
 /**
  * @author Christian Basler
  */
-object Singleton {
-    private var cryptography by Delegates.notNull<Cryptography>()
+public class Singleton {
+    private static Cryptography cryptography;
 
-    @Synchronized
-    @JvmStatic fun initialize(cryptography: Cryptography) {
-        Singleton.cryptography = cryptography
+    public static void initialize(Cryptography cryptography) {
+        synchronized (Singleton.class) {
+            Singleton.cryptography = cryptography;
+        }
     }
 
-    @JvmStatic fun cryptography(): Cryptography {
-        return cryptography
+    public static Cryptography cryptography() {
+        return cryptography;
     }
 }

core/src/main/java/ch/dissem/bitmessage/utils/SqlStrings.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2016 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+import ch.dissem.bitmessage.entity.payload.ObjectType;
+
+import static ch.dissem.bitmessage.utils.Strings.hex;
+
+public class SqlStrings {
+    public static StringBuilder join(long... objects) {
+        StringBuilder streamList = new StringBuilder();
+        for (int i = 0; i < objects.length; i++) {
+            if (i > 0) streamList.append(", ");
+            streamList.append(objects[i]);
+        }
+        return streamList;
+    }
+
+    public static StringBuilder join(byte[]... objects) {
+        StringBuilder streamList = new StringBuilder();
+        for (int i = 0; i < objects.length; i++) {
+            if (i > 0) streamList.append(", ");
+            streamList.append(hex(objects[i]));
+        }
+        return streamList;
+    }
+
+    public static StringBuilder join(ObjectType... types) {
+        StringBuilder streamList = new StringBuilder();
+        for (int i = 0; i < types.length; i++) {
+            if (i > 0) streamList.append(", ");
+            streamList.append(types[i].getNumber());
+        }
+        return streamList;
+    }
+
+    public static StringBuilder join(Enum... types) {
+        StringBuilder streamList = new StringBuilder();
+        for (int i = 0; i < types.length; i++) {
+            if (i > 0) streamList.append(", ");
+            streamList.append('\'').append(types[i].name()).append('\'');
+        }
+        return streamList;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/Strings.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 Christian Basler
+ * Copyright 2015 Christian Basler
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -14,27 +14,27 @@
  * limitations under the License.
  */
 
-package ch.dissem.bitmessage.utils
+package ch.dissem.bitmessage.utils;
 
 /**
  * Some utilities to handle strings.
  * TODO: Probably this should be split in a GUI related and an SQL related utility class.
  */
-object Strings {
-    @JvmStatic fun join(vararg objects: Any): String {
-        return objects.joinToString()
+public class Strings {
+    public static StringBuilder join(Object... objects) {
+        StringBuilder streamList = new StringBuilder();
+        for (int i = 0; i < objects.length; i++) {
+            if (i > 0) streamList.append(", ");
+            streamList.append(objects[i]);
+        }
+        return streamList;
     }
 
-    @JvmStatic fun hex(bytes: ByteArray): String {
-        return bytes.map { String.format("%02x", it) }.joinToString(separator = "")
+    public static StringBuilder hex(byte[] bytes) {
+        StringBuilder hex = new StringBuilder(bytes.length + 2);
+        for (byte b : bytes) {
+            hex.append(String.format("%02x", b));
         }
-
-    @JvmStatic fun str(o: Any?): String? {
-        return o?.toString()
-    }
-
-    @JvmName("strNonNull")
-    @JvmStatic fun str(o: Any): String {
-        return o.toString()
+        return hex;
     }
 }

core/src/main/java/ch/dissem/bitmessage/utils/TTL.java

@@ -0,0 +1,40 @@
+package ch.dissem.bitmessage.utils;
+
+import static ch.dissem.bitmessage.utils.UnixTime.DAY;
+
+/**
+ * Stores times to live for different object types. Usually this shouldn't be messed with,
+ * but for tests it might be a good idea to reduce it to a minimum, and on mobile clients
+ * you might want to optimize it as well.
+ *
+ * @author Christian Basler
+ */
+public class TTL {
+    private static long msg = 2 * DAY;
+    private static long getpubkey = 2 * DAY;
+    private static long pubkey = 28 * DAY;
+
+    public static long msg() {
+        return msg;
+    }
+
+    public static void msg(long msg) {
+        TTL.msg = msg;
+    }
+
+    public static long getpubkey() {
+        return getpubkey;
+    }
+
+    public static void getpubkey(long getpubkey) {
+        TTL.getpubkey = getpubkey;
+    }
+
+    public static long pubkey() {
+        return pubkey;
+    }
+
+    public static void pubkey(long pubkey) {
+        TTL.pubkey = pubkey;
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/ThreadFactoryBuilder.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2016 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class ThreadFactoryBuilder {
+    private final String namePrefix;
+    private int prio = Thread.NORM_PRIORITY;
+    private boolean daemon = false;
+
+    private ThreadFactoryBuilder(String pool) {
+        this.namePrefix = pool + "-thread-";
+    }
+
+
+    public static ThreadFactoryBuilder pool(String name) {
+        return new ThreadFactoryBuilder(name);
+    }
+
+    public ThreadFactoryBuilder lowPrio() {
+        prio = Thread.MIN_PRIORITY;
+        return this;
+    }
+
+    public ThreadFactoryBuilder daemon() {
+        daemon = true;
+        return this;
+    }
+
+    public ThreadFactory build() {
+        SecurityManager s = System.getSecurityManager();
+        final ThreadGroup group = (s != null) ? s.getThreadGroup() :
+                Thread.currentThread().getThreadGroup();
+
+        return new ThreadFactory() {
+            private final AtomicInteger threadNumber = new AtomicInteger(1);
+
+            @Override
+            public Thread newThread(Runnable r) {
+                Thread t = new Thread(group, r,
+                        namePrefix + threadNumber.getAndIncrement(),
+                        0);
+                t.setPriority(prio);
+                t.setDaemon(daemon);
+                return t;
+            }
+        };
+    }
+}

core/src/main/java/ch/dissem/bitmessage/utils/UnixTime.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2015 Christian Basler
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package ch.dissem.bitmessage.utils;
+
+/**
+ * A simple utility class that simplifies using the second based time used in Bitmessage.
+ */
+public class UnixTime {
+    /**
+     * Length of a minute in seconds, intended for use with {@link #now(long)}.
+     */
+    public static final int MINUTE = 60;
+    /**
+     * Length of an hour in seconds, intended for use with {@link #now(long)}.
+     */
+    public static final long HOUR = 60 * MINUTE;
+    /**
+     * Length of a day in seconds, intended for use with {@link #now(long)}.
+     */
+    public static final long DAY = 24 * HOUR;
+
+    /**
+     * @return the time in second based Unix time ({@link System#currentTimeMillis()}/1000)
+     */
+    public static long now() {
+        return System.currentTimeMillis() / 1000;
+    }
+
+    /**
+     * Same as {@link #now()} + shiftSeconds, but might be more readable.
+     *
+     * @param shiftSeconds number of seconds from now we're interested in
+     * @return the Unix time in shiftSeconds seconds / shiftSeconds seconds ago
+     */
+    public static long now(long shiftSeconds) {
+        return (System.currentTimeMillis() / 1000) + shiftSeconds;
+    }
+}

core/src/main/kotlin/ch/dissem/bitmessage/BitmessageContext.kt

@@ -1,465 +0,0 @@
-/*
- * Copyright 2015 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage
-
-import ch.dissem.bitmessage.BitmessageContext.Companion.version
-import ch.dissem.bitmessage.InternalContext.Companion.NETWORK_EXTRA_BYTES
-import ch.dissem.bitmessage.InternalContext.Companion.NETWORK_NONCE_TRIALS_PER_BYTE
-import ch.dissem.bitmessage.entity.BitmessageAddress
-import ch.dissem.bitmessage.entity.CustomMessage
-import ch.dissem.bitmessage.entity.MessagePayload
-import ch.dissem.bitmessage.entity.Plaintext
-import ch.dissem.bitmessage.entity.Plaintext.Status.DRAFT
-import ch.dissem.bitmessage.entity.Plaintext.Type.BROADCAST
-import ch.dissem.bitmessage.entity.Plaintext.Type.MSG
-import ch.dissem.bitmessage.entity.payload.Broadcast
-import ch.dissem.bitmessage.entity.payload.ObjectType
-import ch.dissem.bitmessage.entity.payload.Pubkey.Feature
-import ch.dissem.bitmessage.entity.valueobject.PrivateKey
-import ch.dissem.bitmessage.exception.DecryptionFailedException
-import ch.dissem.bitmessage.factory.Factory
-import ch.dissem.bitmessage.ports.*
-import ch.dissem.bitmessage.utils.Property
-import ch.dissem.bitmessage.utils.UnixTime.MINUTE
-import org.slf4j.LoggerFactory
-import java.net.InetAddress
-import java.util.concurrent.CancellationException
-import java.util.concurrent.ExecutionException
-import kotlin.properties.Delegates
-
-/**
- *
- * Use this class if you want to create a Bitmessage client.
- * You'll need the Builder to create a BitmessageContext, and set the following properties:
- *
- *  * addressRepo
- *  * inventory
- *  * nodeRegistry
- *  * networkHandler
- *  * messageRepo
- *  * streams
- *
- *
- * The default implementations in the different module builds can be used.
- *
- * The port defaults to 8444 (the default Bitmessage port)
- */
-class BitmessageContext private constructor(builder: BitmessageContext.Builder) {
-
-    /**
-     * The [InternalContext] - normally you wouldn't need it,
-     * unless you are doing something crazy with the protocol.
-     */
-    val internals: InternalContext
-        @JvmName("internals") get
-
-    val labeler: Labeler
-        @JvmName("labeler") get
-
-    val addresses: AddressRepository
-        @JvmName("addresses") get
-
-    val labels: LabelRepository
-        @JvmName("labels") get
-
-    val messages: MessageRepository
-        @JvmName("messages") get
-
-    fun createIdentity(shorter: Boolean, vararg features: Feature): BitmessageAddress {
-        val identity = BitmessageAddress(PrivateKey(
-            shorter,
-            internals.streams[0],
-            NETWORK_NONCE_TRIALS_PER_BYTE,
-            NETWORK_EXTRA_BYTES,
-            *features
-        ))
-        internals.addressRepository.save(identity)
-        if (internals.preferences.sendPubkeyOnIdentityCreation) {
-            internals.sendPubkey(identity, identity.stream)
-        }
-        return identity
-    }
-
-    fun joinChan(passphrase: String, address: String): BitmessageAddress {
-        val chan = BitmessageAddress.chan(address, passphrase)
-        chan.alias = passphrase
-        internals.addressRepository.save(chan)
-        return chan
-    }
-
-    fun createChan(passphrase: String): BitmessageAddress {
-        // FIXME: hardcoded stream number
-        val chan = BitmessageAddress.chan(1, passphrase)
-        internals.addressRepository.save(chan)
-        return chan
-    }
-
-    fun createDeterministicAddresses(
-        passphrase: String, numberOfAddresses: Int, version: Long, stream: Long, shorter: Boolean): List<BitmessageAddress> {
-        val result = BitmessageAddress.deterministic(
-            passphrase, numberOfAddresses, version, stream, shorter)
-        for (i in result.indices) {
-            val address = result[i]
-            address.alias = "deterministic (" + (i + 1) + ")"
-            internals.addressRepository.save(address)
-        }
-        return result
-    }
-
-    fun broadcast(from: BitmessageAddress, subject: String, message: String) {
-        send(Plaintext(
-            type = BROADCAST,
-            from = from,
-            subject = subject,
-            body = message,
-            status = DRAFT
-        ))
-    }
-
-    fun send(from: BitmessageAddress, to: BitmessageAddress, subject: String, message: String) {
-        if (from.privateKey == null) {
-            throw IllegalArgumentException("'From' must be an identity, i.e. have a private key.")
-        }
-        send(Plaintext(
-            type = MSG,
-            from = from,
-            to = to,
-            subject = subject,
-            body = message
-        ))
-    }
-
-    fun send(msg: Plaintext) {
-        if (msg.from.privateKey == null) {
-            throw IllegalArgumentException("'From' must be an identity, i.e. have a private key.")
-        }
-        labeler.markAsSending(msg)
-        val to = msg.to
-        if (to != null) {
-            if (to.pubkey == null) {
-                LOG.info("Public key is missing from recipient. Requesting.")
-                internals.requestPubkey(to)
-            }
-            if (to.pubkey == null) {
-                internals.messageRepository.save(msg)
-            }
-        }
-        if (to == null || to.pubkey != null) {
-            LOG.info("Sending message.")
-            internals.messageRepository.save(msg)
-            if (msg.type == MSG) {
-                internals.send(msg)
-            } else {
-                internals.send(
-                    msg.from,
-                    to,
-                    Factory.getBroadcast(msg),
-                    msg.ttl
-                )
-            }
-        }
-    }
-
-    fun startup() {
-        internals.networkHandler.start()
-    }
-
-    fun shutdown() {
-        internals.networkHandler.stop()
-    }
-
-    /**
-     * @param host             a trusted node that must be reliable (it's used for every synchronization)
-     * @param port             of the trusted host, default is 8444
-     * @param timeoutInSeconds synchronization should end no later than about 5 seconds after the timeout elapsed,
-     *                         even if not all objects were fetched
-     * @param wait             waits for the synchronization thread to finish
-     */
-    fun synchronize(host: InetAddress, port: Int, timeoutInSeconds: Long, wait: Boolean) {
-        val future = internals.networkHandler.synchronize(host, port, timeoutInSeconds)
-        if (wait) {
-            try {
-                future.get()
-            } catch (e: InterruptedException) {
-                LOG.info("Thread was interrupted. Trying to shut down synchronization and returning.")
-                future.cancel(true)
-            } catch (e: CancellationException) {
-                LOG.debug(e.message, e)
-            } catch (e: ExecutionException) {
-                LOG.debug(e.message, e)
-            }
-
-        }
-    }
-
-    /**
-     * Send a custom message to a specific node (that should implement handling for this message type) and returns
-     * the response, which in turn is expected to be a [CustomMessage].
-     *
-     * @param server  the node's address
-     * @param port    the node's port
-     * @param request the request
-     * @return the response
-     */
-    fun send(server: InetAddress, port: Int, request: CustomMessage): CustomMessage =
-        internals.networkHandler.send(server, port, request)
-
-    /**
-     * Removes expired objects from the inventory. You should call this method regularly,
-     * e.g. daily and on each shutdown.
-     */
-    fun cleanup() {
-        internals.inventory.cleanup()
-        internals.nodeRegistry.cleanup()
-    }
-
-    /**
-     * Sends messages again whose time to live expired without being acknowledged. (And whose
-     * recipient is expected to send acknowledgements.
-     *
-     * You should call this method regularly, but be aware of the following:
-     *
-     *  * As messages might be sent, POW will be done. It is therefore not advised to
-     *    call it on shutdown.
-     *  * It shouldn't be called right after startup, as it's possible the missing
-     *    acknowledgement was sent while the client was offline.
-     *  * Other than that, the call isn't expensive as long as there is no message
-     *    to send, so it might be a good idea to just call it every few minutes.
-     */
-    fun resendUnacknowledgedMessages() {
-        internals.resendUnacknowledged()
-    }
-
-    fun isRunning() = internals.networkHandler.isRunning
-
-    fun addContact(contact: BitmessageAddress) {
-        internals.addressRepository.save(contact)
-        if (contact.pubkey == null) {
-            // If it already existed, the saved contact might have the public key
-            if (internals.addressRepository.getAddress(contact.address)!!.pubkey == null) {
-                internals.requestPubkey(contact)
-            }
-        }
-    }
-
-    fun addSubscribtion(address: BitmessageAddress) {
-        address.isSubscribed = true
-        internals.addressRepository.save(address)
-        tryToFindBroadcastsForAddress(address)
-    }
-
-    private fun tryToFindBroadcastsForAddress(address: BitmessageAddress) {
-        for (objectMessage in internals.inventory.getObjects(address.stream, Broadcast.getVersion(address), ObjectType.BROADCAST)) {
-            try {
-                val broadcast = objectMessage.payload as Broadcast
-                broadcast.decrypt(address)
-                // This decrypts it twice, but on the other hand it doesn't try to decrypt the objects with
-                // other subscriptions and the interface stays as simple as possible.
-                internals.networkListener.receive(objectMessage)
-            } catch (ignore: DecryptionFailedException) {
-            } catch (e: Exception) {
-                LOG.debug(e.message, e)
-            }
-        }
-    }
-
-    fun status(): Property {
-        return Property("status",
-            Property("user agent", internals.preferences.userAgent),
-            internals.networkHandler.getNetworkStatus(),
-            Property("unacknowledged", internals.messageRepository.findMessagesToResend().size)
-        )
-    }
-
-    interface Listener {
-        fun receive(plaintext: Plaintext)
-
-        /**
-         * A message listener that needs a [BitmessageContext], i.e. for implementing some sort of chat bot.
-         */
-        interface WithContext : Listener {
-            fun setContext(ctx: BitmessageContext)
-        }
-    }
-
-    /**
-     * Kotlin users: you might want to use [BitmessageContext.build] instead.
-     */
-    class Builder {
-        var inventory by Delegates.notNull<Inventory>()
-        var nodeRegistry by Delegates.notNull<NodeRegistry>()
-        var networkHandler by Delegates.notNull<NetworkHandler>()
-        var addressRepo by Delegates.notNull<AddressRepository>()
-        var labelRepo by Delegates.notNull<LabelRepository>()
-        var messageRepo by Delegates.notNull<MessageRepository>()
-        var proofOfWorkRepo by Delegates.notNull<ProofOfWorkRepository>()
-        var proofOfWorkEngine: ProofOfWorkEngine? = null
-        var cryptography by Delegates.notNull<Cryptography>()
-        var customCommandHandler: CustomCommandHandler? = null
-        var labeler: Labeler? = null
-        var listener by Delegates.notNull<Listener>()
-        val preferences = Preferences()
-
-        fun inventory(inventory: Inventory): Builder {
-            this.inventory = inventory
-            return this
-        }
-
-        fun nodeRegistry(nodeRegistry: NodeRegistry): Builder {
-            this.nodeRegistry = nodeRegistry
-            return this
-        }
-
-        fun networkHandler(networkHandler: NetworkHandler): Builder {
-            this.networkHandler = networkHandler
-            return this
-        }
-
-        fun addressRepo(addressRepo: AddressRepository): Builder {
-            this.addressRepo = addressRepo
-            return this
-        }
-
-        fun labelRepo(labelRepo: LabelRepository): Builder {
-            this.labelRepo = labelRepo
-            return this
-        }
-
-        fun messageRepo(messageRepo: MessageRepository): Builder {
-            this.messageRepo = messageRepo
-            return this
-        }
-
-        fun powRepo(proofOfWorkRepository: ProofOfWorkRepository): Builder {
-            this.proofOfWorkRepo = proofOfWorkRepository
-            return this
-        }
-
-        fun cryptography(cryptography: Cryptography): Builder {
-            this.cryptography = cryptography
-            return this
-        }
-
-        fun customCommandHandler(handler: CustomCommandHandler): Builder {
-            this.customCommandHandler = handler
-            return this
-        }
-
-        fun proofOfWorkEngine(proofOfWorkEngine: ProofOfWorkEngine): Builder {
-            this.proofOfWorkEngine = proofOfWorkEngine
-            return this
-        }
-
-        fun labeler(labeler: Labeler): Builder {
-            this.labeler = labeler
-            return this
-        }
-
-        fun listener(listener: Listener): Builder {
-            this.listener = listener
-            return this
-        }
-
-        @JvmSynthetic
-        fun listener(listener: (Plaintext) -> Unit): Builder {
-            this.listener = object : Listener {
-                override fun receive(plaintext: Plaintext) {
-                    listener.invoke(plaintext)
-                }
-            }
-            return this
-        }
-
-        fun build() = BitmessageContext(this)
-    }
-
-    init {
-        this.labeler = builder.labeler ?: DefaultLabeler()
-        this.internals = InternalContext(
-            builder.cryptography,
-            builder.inventory,
-            builder.nodeRegistry,
-            builder.networkHandler,
-            builder.addressRepo,
-            builder.labelRepo,
-            builder.messageRepo,
-            builder.proofOfWorkRepo,
-            builder.proofOfWorkEngine ?: MultiThreadedPOWEngine(),
-            builder.customCommandHandler ?: object : CustomCommandHandler {
-                override fun handle(request: CustomMessage): MessagePayload? {
-                    BitmessageContext.LOG.debug("Received custom request, but no custom command handler configured.")
-                    return null
-                }
-            },
-            builder.listener,
-            labeler,
-            builder.preferences
-        )
-        this.addresses = builder.addressRepo
-        this.labels = builder.labelRepo
-        this.messages = builder.messageRepo
-        (builder.listener as? Listener.WithContext)?.setContext(this)
-        internals.proofOfWorkService.doMissingProofOfWork(builder.preferences.doMissingProofOfWorkDelayInSeconds * 1000L)
-    }
-
-    companion object {
-        @JvmField
-        val CURRENT_VERSION = 3
-        private val LOG = LoggerFactory.getLogger(BitmessageContext::class.java)
-
-        val version: String by lazy {
-            BitmessageContext::class.java.getResource("/version")?.readText() ?: "local build"
-        }
-            @JvmStatic get
-
-        @JvmSynthetic
-        inline fun build(block: Builder.() -> Unit): BitmessageContext {
-            val builder = Builder()
-            block(builder)
-            return builder.build()
-        }
-
-    }
-}
-
-class Preferences {
-    var port = 8444
-    /**
-     * Defaults to "/Jabit:<version>/", and whatever you set will be inserted into "/<your user agent>/Jabit:<version>/"
-     */
-    var userAgent = "/Jabit:$version/"
-        set(value) {
-            field = "/$value/Jabit:$version/"
-        }
-    /**
-     * Time to live for any connection
-     */
-    var connectionTTL = 30 * MINUTE
-    /**
-     * Maximum number of connections. Values below 8 would probably result in erratic behaviour, so you shouldn't do that.
-     */
-    var connectionLimit = 150
-    /**
-     * By default a client will send the public key when an identity is being created. On weaker devices
-     * this behaviour might not be desirable.
-     */
-    var sendPubkeyOnIdentityCreation = true
-    /**
-     * Delay in seconds before outstandinng proof of work is calculated.
-     */
-    var doMissingProofOfWorkDelayInSeconds = 30
-}

core/src/main/kotlin/ch/dissem/bitmessage/DefaultMessageListener.kt

@@ -1,180 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage
-
-import ch.dissem.bitmessage.entity.BitmessageAddress
-import ch.dissem.bitmessage.entity.ObjectMessage
-import ch.dissem.bitmessage.entity.Plaintext
-import ch.dissem.bitmessage.entity.Plaintext.Status.PUBKEY_REQUESTED
-import ch.dissem.bitmessage.entity.payload.*
-import ch.dissem.bitmessage.entity.valueobject.InventoryVector
-import ch.dissem.bitmessage.exception.DecryptionFailedException
-import ch.dissem.bitmessage.ports.AlreadyStoredException
-import ch.dissem.bitmessage.ports.Labeler
-import ch.dissem.bitmessage.ports.NetworkHandler
-import ch.dissem.bitmessage.utils.Strings.hex
-import org.slf4j.LoggerFactory
-import java.util.*
-
-open class DefaultMessageListener(
-    private val labeler: Labeler,
-    private val listener: BitmessageContext.Listener
-) : NetworkHandler.MessageListener, InternalContext.ContextHolder {
-    private lateinit var ctx: InternalContext
-
-    override fun setContext(context: InternalContext) {
-        ctx = context
-    }
-
-    override fun receive(objectMessage: ObjectMessage) {
-        val payload = objectMessage.payload
-
-        when (payload.type) {
-            ObjectType.GET_PUBKEY -> {
-                receive(objectMessage, payload as GetPubkey)
-            }
-            ObjectType.PUBKEY -> {
-                receive(payload as Pubkey)
-            }
-            ObjectType.MSG -> {
-                receive(objectMessage, payload as Msg)
-            }
-            ObjectType.BROADCAST -> {
-                receive(objectMessage, payload as Broadcast)
-            }
-            null -> {
-                if (payload is GenericPayload) {
-                    receive(payload)
-                }
-            }
-        }
-    }
-
-    protected fun receive(objectMessage: ObjectMessage, getPubkey: GetPubkey) {
-        val identity = ctx.addressRepository.findIdentity(getPubkey.ripeTag)
-        if (identity?.privateKey != null && !identity.isChan) {
-            LOG.info("Got pubkey request for identity " + identity)
-            // FIXME: only send pubkey if it wasn't sent in the last TTL.pubkey() days
-            ctx.sendPubkey(identity, objectMessage.stream)
-        }
-    }
-
-    protected fun receive(pubkey: Pubkey) {
-        try {
-            if (pubkey is V4Pubkey) {
-                ctx.addressRepository.findContact(pubkey.tag)?.let {
-                    if (it.pubkey == null) {
-                        pubkey.decrypt(it.publicDecryptionKey)
-                        updatePubkey(it, pubkey)
-                    }
-                }
-            } else {
-                ctx.addressRepository.findContact(pubkey.ripe)?.let {
-                    if (it.pubkey == null) {
-                        updatePubkey(it, pubkey)
-                    }
-                }
-            }
-        } catch (_: DecryptionFailedException) {
-        }
-    }
-
-    private fun updatePubkey(address: BitmessageAddress, pubkey: Pubkey) {
-        address.pubkey = pubkey
-        LOG.info("Got pubkey for contact " + address)
-        ctx.addressRepository.save(address)
-        val messages = ctx.messageRepository.findMessages(PUBKEY_REQUESTED, address)
-        LOG.info("Sending " + messages.size + " messages for contact " + address)
-        for (msg in messages) {
-            ctx.labeler.markAsSending(msg)
-            ctx.messageRepository.save(msg)
-            ctx.send(msg)
-        }
-    }
-
-    protected fun receive(objectMessage: ObjectMessage, msg: Msg) {
-        for (identity in ctx.addressRepository.getIdentities()) {
-            try {
-                msg.decrypt(identity.privateKey!!.privateEncryptionKey)
-                val plaintext = msg.plaintext!!
-                plaintext.to = identity
-                if (!objectMessage.isSignatureValid(plaintext.from.pubkey!!)) {
-                    LOG.warn("Msg with IV " + objectMessage.inventoryVector + " was successfully decrypted, but signature check failed. Ignoring.")
-                } else {
-                    receive(objectMessage.inventoryVector, plaintext)
-                }
-                break
-            } catch (_: DecryptionFailedException) {
-            }
-        }
-    }
-
-    protected fun receive(ack: GenericPayload) {
-        if (ack.data.size == Msg.ACK_LENGTH) {
-            ctx.messageRepository.getMessageForAck(ack.data)?.let {
-                ctx.labeler.markAsAcknowledged(it)
-                ctx.messageRepository.save(it)
-            } ?: LOG.debug("Message not found for ack ${hex(ack.data)}")
-        }
-    }
-
-    protected fun receive(objectMessage: ObjectMessage, broadcast: Broadcast) {
-        val tag = (broadcast as? V5Broadcast)?.tag
-        ctx.addressRepository.getSubscriptions(broadcast.version)
-            .filter { tag == null || Arrays.equals(tag, it.tag) }
-            .forEach {
-                try {
-                    broadcast.decrypt(it.publicDecryptionKey)
-                    if (!objectMessage.isSignatureValid(broadcast.plaintext!!.from.pubkey!!)) {
-                        LOG.warn("Broadcast with IV " + objectMessage.inventoryVector + " was successfully decrypted, but signature check failed. Ignoring.")
-                    } else {
-                        receive(objectMessage.inventoryVector, broadcast.plaintext!!)
-                    }
-                } catch (_: DecryptionFailedException) {
-                }
-            }
-    }
-
-    protected fun receive(iv: InventoryVector, msg: Plaintext) {
-        val contact = ctx.addressRepository.getAddress(msg.from.address)
-        if (contact != null && contact.pubkey == null) {
-            updatePubkey(contact, msg.from.pubkey!!)
-        }
-
-        msg.inventoryVector = iv
-        try {
-            ctx.messageRepository.save(msg)
-            // We might need the ID here, so we need to add the labels and save it again
-            labeler.setLabels(msg)
-            ctx.messageRepository.save(msg)
-            listener.receive(msg)
-
-            if (msg.type == Plaintext.Type.MSG && msg.to!!.has(Pubkey.Feature.DOES_ACK)) {
-                msg.ackMessage?.let {
-                    ctx.inventory.storeObject(it)
-                    ctx.networkHandler.offer(it.inventoryVector)
-                } ?: LOG.debug("ack message expected")
-            }
-        } catch (e: AlreadyStoredException) {
-            LOG.trace("Message was already received before.", e)
-        }
-    }
-
-    companion object {
-        private val LOG = LoggerFactory.getLogger(DefaultMessageListener::class.java)
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/InternalContext.kt

@@ -1,225 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage
-
-import ch.dissem.bitmessage.entity.BitmessageAddress
-import ch.dissem.bitmessage.entity.Encrypted
-import ch.dissem.bitmessage.entity.ObjectMessage
-import ch.dissem.bitmessage.entity.Plaintext
-import ch.dissem.bitmessage.entity.payload.*
-import ch.dissem.bitmessage.ports.*
-import ch.dissem.bitmessage.utils.Singleton
-import ch.dissem.bitmessage.utils.TTL
-import ch.dissem.bitmessage.utils.UnixTime
-import org.slf4j.LoggerFactory
-import java.util.*
-import java.util.concurrent.Executors
-
-/**
- * The internal context should normally only be used for port implementations. If you need it in your client
- * implementation, you're either doing something wrong, something very weird, or the BitmessageContext should
- * get extended.
- *
- *
- * On the other hand, if you need the BitmessageContext in a port implementation, the same thing might apply.
- *
- */
-class InternalContext(
-    val cryptography: Cryptography,
-    val inventory: Inventory,
-    val nodeRegistry: NodeRegistry,
-    val networkHandler: NetworkHandler,
-    val addressRepository: AddressRepository,
-    val labelRepository: LabelRepository,
-    val messageRepository: MessageRepository,
-    val proofOfWorkRepository: ProofOfWorkRepository,
-    val proofOfWorkEngine: ProofOfWorkEngine,
-    val customCommandHandler: CustomCommandHandler,
-    listener: BitmessageContext.Listener,
-    val labeler: Labeler,
-
-    val preferences: Preferences
-) {
-
-    private val threadPool = Executors.newCachedThreadPool()
-
-    val proofOfWorkService: ProofOfWorkService = ProofOfWorkService()
-    val networkListener: NetworkHandler.MessageListener = DefaultMessageListener(labeler, listener)
-    val clientNonce: Long = cryptography.randomNonce()
-    private val _streams = TreeSet<Long>()
-    val streams: LongArray
-        get() = _streams.toLongArray()
-
-    init {
-        Singleton.initialize(cryptography)
-
-        // TODO: streams of new identities and subscriptions should also be added. This works only after a restart.
-        addressRepository.getIdentities().mapTo(_streams) { it.stream }
-        addressRepository.getSubscriptions().mapTo(_streams) { it.stream }
-        if (_streams.isEmpty()) {
-            _streams.add(1L)
-        }
-
-        init(cryptography, inventory, nodeRegistry, networkHandler, addressRepository, messageRepository,
-            proofOfWorkRepository, proofOfWorkService, proofOfWorkEngine, customCommandHandler, labeler,
-            networkListener)
-    }
-
-    private fun init(vararg objects: Any) {
-        objects.filter { it is ContextHolder }.forEach { (it as ContextHolder).setContext(this) }
-    }
-
-    fun send(plaintext: Plaintext) {
-        if (plaintext.ackMessage != null) {
-            val expires = UnixTime.now + plaintext.ttl
-            LOG.info("Expires at " + expires)
-            proofOfWorkService.doProofOfWorkWithAck(plaintext, expires)
-        } else {
-            send(plaintext.from, plaintext.to, Msg(plaintext), plaintext.ttl)
-        }
-    }
-
-    fun send(from: BitmessageAddress, to: BitmessageAddress?, payload: ObjectPayload,
-             timeToLive: Long) {
-        val recipient = to ?: from
-        val expires = UnixTime.now + timeToLive
-        LOG.info("Expires at " + expires)
-        val objectMessage = ObjectMessage(
-            stream = recipient.stream,
-            expiresTime = expires,
-            payload = payload
-        )
-        if (objectMessage.isSigned) {
-            objectMessage.sign(
-                from.privateKey ?: throw IllegalArgumentException("The given sending address is no identity")
-            )
-        }
-        if (payload is Broadcast) {
-            payload.encrypt()
-        } else if (payload is Encrypted) {
-            objectMessage.encrypt(
-                recipient.pubkey ?: throw IllegalArgumentException("The public key for the recipient isn't available")
-            )
-        }
-        proofOfWorkService.doProofOfWork(to, objectMessage)
-    }
-
-    fun sendPubkey(identity: BitmessageAddress, targetStream: Long) {
-        val expires = UnixTime.now + TTL.pubkey
-        LOG.info("Expires at " + expires)
-        val payload = identity.pubkey ?: throw IllegalArgumentException("The given address is no identity")
-        val response = ObjectMessage(
-            expiresTime = expires,
-            stream = targetStream,
-            payload = payload
-        )
-        response.sign(
-            identity.privateKey ?: throw IllegalArgumentException("The given address is no identity")
-        )
-        response.encrypt(cryptography.createPublicKey(identity.publicDecryptionKey))
-        // TODO: remember that the pubkey is just about to be sent, and on which stream!
-        proofOfWorkService.doProofOfWork(response)
-    }
-
-    /**
-     * Be aware that if the pubkey already exists in the inventory, the metods will not request it and the callback
-     * for freshly received pubkeys will not be called. Instead the pubkey is added to the contact and stored on DB.
-     */
-    fun requestPubkey(contact: BitmessageAddress) {
-        threadPool.execute {
-            val stored = addressRepository.getAddress(contact.address)
-
-            tryToFindMatchingPubkey(contact)
-            if (contact.pubkey != null) {
-                if (stored != null) {
-                    stored.pubkey = contact.pubkey
-                    addressRepository.save(stored)
-                } else {
-                    addressRepository.save(contact)
-                }
-                return@execute
-            }
-
-            if (stored == null) {
-                addressRepository.save(contact)
-            }
-
-            val expires = UnixTime.now + TTL.getpubkey
-            LOG.info("Expires at $expires")
-            val request = ObjectMessage(
-                stream = contact.stream,
-                expiresTime = expires,
-                payload = GetPubkey(contact)
-            )
-            proofOfWorkService.doProofOfWork(request)
-        }
-    }
-
-    private fun tryToFindMatchingPubkey(address: BitmessageAddress) {
-        addressRepository.getAddress(address.address)?.let {
-            address.alias = it.alias
-            address.isSubscribed = it.isSubscribed
-        }
-        for (objectMessage in inventory.getObjects(address.stream, address.version, ObjectType.PUBKEY)) {
-            try {
-                val pubkey = objectMessage.payload as Pubkey
-                if (address.version == 4L) {
-                    val v4Pubkey = pubkey as V4Pubkey
-                    if (Arrays.equals(address.tag, v4Pubkey.tag)) {
-                        v4Pubkey.decrypt(address.publicDecryptionKey)
-                        if (objectMessage.isSignatureValid(v4Pubkey)) {
-                            address.pubkey = v4Pubkey
-                            addressRepository.save(address)
-                            break
-                        } else {
-                            LOG.info("Found pubkey for $address but signature is invalid")
-                        }
-                    }
-                } else {
-                    if (Arrays.equals(pubkey.ripe, address.ripe)) {
-                        address.pubkey = pubkey
-                        addressRepository.save(address)
-                        break
-                    }
-                }
-            } catch (e: Exception) {
-                LOG.debug(e.message, e)
-            }
-        }
-    }
-
-    fun resendUnacknowledged() {
-        val messages = messageRepository.findMessagesToResend()
-        for (message in messages) {
-            send(message)
-            messageRepository.save(message)
-        }
-    }
-
-    interface ContextHolder {
-        fun setContext(context: InternalContext)
-    }
-
-    companion object {
-        private val LOG = LoggerFactory.getLogger(InternalContext::class.java)
-
-        @JvmField
-        val NETWORK_NONCE_TRIALS_PER_BYTE: Long = 1000
-        @JvmField
-        val NETWORK_EXTRA_BYTES: Long = 1000
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/ProofOfWorkService.kt

@@ -1,121 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage
-
-import ch.dissem.bitmessage.InternalContext.Companion.NETWORK_EXTRA_BYTES
-import ch.dissem.bitmessage.InternalContext.Companion.NETWORK_NONCE_TRIALS_PER_BYTE
-import ch.dissem.bitmessage.entity.*
-import ch.dissem.bitmessage.entity.payload.Msg
-import ch.dissem.bitmessage.ports.ProofOfWorkEngine
-import ch.dissem.bitmessage.ports.ProofOfWorkRepository.Item
-import org.slf4j.LoggerFactory
-import java.util.*
-
-/**
- * @author Christian Basler
- */
-class ProofOfWorkService : ProofOfWorkEngine.Callback, InternalContext.ContextHolder {
-
-    private lateinit var ctx: InternalContext
-    private val cryptography by lazy { ctx.cryptography }
-    private val powRepo by lazy { ctx.proofOfWorkRepository }
-    private val messageRepo by lazy { ctx.messageRepository }
-
-    override fun setContext(context: InternalContext) {
-        ctx = context
-    }
-
-    fun doMissingProofOfWork(delayInMilliseconds: Long) {
-        val items = powRepo.getItems()
-        if (items.isEmpty()) return
-
-        // Wait for 30 seconds, to let the application start up before putting heavy load on the CPU
-        Timer().schedule(object : TimerTask() {
-            override fun run() {
-                LOG.info("Doing POW for " + items.size + " tasks.")
-                for (initialHash in items) {
-                    val (objectMessage, nonceTrialsPerByte, extraBytes) = powRepo.getItem(initialHash)
-                    cryptography.doProofOfWork(objectMessage, nonceTrialsPerByte, extraBytes,
-                        this@ProofOfWorkService)
-                }
-            }
-        }, delayInMilliseconds)
-    }
-
-    fun doProofOfWork(objectMessage: ObjectMessage) {
-        doProofOfWork(null, objectMessage)
-    }
-
-    fun doProofOfWork(recipient: BitmessageAddress?, objectMessage: ObjectMessage) {
-        val pubkey = recipient?.pubkey
-
-        val nonceTrialsPerByte = pubkey?.nonceTrialsPerByte ?: NETWORK_NONCE_TRIALS_PER_BYTE
-        val extraBytes = pubkey?.extraBytes ?: NETWORK_EXTRA_BYTES
-
-        powRepo.putObject(objectMessage, nonceTrialsPerByte, extraBytes)
-        if (objectMessage.payload is PlaintextHolder) {
-            objectMessage.payload.plaintext?.let {
-                it.initialHash = cryptography.getInitialHash(objectMessage)
-                messageRepo.save(it)
-            } ?: LOG.error("PlaintextHolder without Plaintext shouldn't make it to the POW")
-        }
-        cryptography.doProofOfWork(objectMessage, nonceTrialsPerByte, extraBytes, this)
-    }
-
-    fun doProofOfWorkWithAck(plaintext: Plaintext, expirationTime: Long) {
-        val ack = plaintext.ackMessage!!
-        messageRepo.save(plaintext)
-        val item = Item(ack, NETWORK_NONCE_TRIALS_PER_BYTE, NETWORK_EXTRA_BYTES,
-            expirationTime, plaintext)
-        powRepo.putObject(item)
-        cryptography.doProofOfWork(ack, NETWORK_NONCE_TRIALS_PER_BYTE, NETWORK_EXTRA_BYTES, this)
-    }
-
-    override fun onNonceCalculated(initialHash: ByteArray, nonce: ByteArray) {
-        val (objectMessage, _, _, expirationTime, message) = powRepo.getItem(initialHash)
-        if (message == null) {
-            objectMessage.nonce = nonce
-            messageRepo.getMessage(initialHash)?.let {
-                it.inventoryVector = objectMessage.inventoryVector
-                it.updateNextTry()
-                ctx.labeler.markAsSent(it)
-                messageRepo.save(it)
-            }
-            ctx.inventory.storeObject(objectMessage)
-            ctx.networkHandler.offer(objectMessage.inventoryVector)
-        } else {
-            message.ackMessage!!.nonce = nonce
-            val newObjectMessage = ObjectMessage.Builder()
-                .stream(message.stream)
-                .expiresTime(expirationTime!!)
-                .payload(Msg(message))
-                .build()
-            if (newObjectMessage.isSigned) {
-                newObjectMessage.sign(message.from.privateKey!!)
-            }
-            if (newObjectMessage.payload is Encrypted) {
-                newObjectMessage.encrypt(message.to!!.pubkey!!)
-            }
-            doProofOfWork(message.to, newObjectMessage)
-        }
-        powRepo.removeObject(initialHash)
-    }
-
-    companion object {
-        private val LOG = LoggerFactory.getLogger(ProofOfWorkService::class.java)
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/constants/constants.kt

@@ -1,27 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.constants
-
-/**
- * Some network constants
- */
-object Network {
-    @JvmField val NETWORK_MAGIC_NUMBER = 8
-    @JvmField val HEADER_SIZE = 24
-    @JvmField val MAX_PAYLOAD_SIZE = 1600003
-    @JvmField val MAX_MESSAGE_SIZE = HEADER_SIZE + MAX_PAYLOAD_SIZE
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/Addr.kt

@@ -1,52 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.entity.valueobject.NetworkAddress
-import ch.dissem.bitmessage.utils.Encode
-import java.io.OutputStream
-import java.nio.ByteBuffer
-
-/**
- * The 'addr' command holds a list of known active Bitmessage nodes.
- */
-data class Addr constructor(val addresses: List<NetworkAddress>) : MessagePayload {
-
-    override val command: MessagePayload.Command = MessagePayload.Command.ADDR
-
-    override fun writer(): StreamableWriter = Writer(this)
-
-    private class Writer(
-        private val item: Addr
-    ) : StreamableWriter {
-
-        override fun write(out: OutputStream) {
-            Encode.varInt(item.addresses.size, out)
-            for (address in item.addresses) {
-                address.writer().write(out)
-            }
-        }
-
-        override fun write(buffer: ByteBuffer) {
-            Encode.varInt(item.addresses.size, buffer)
-            for (address in item.addresses) {
-                address.writer().write(buffer)
-            }
-        }
-
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/BitmessageAddress.kt

@@ -1,195 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.entity.payload.Pubkey
-import ch.dissem.bitmessage.entity.payload.Pubkey.Feature
-import ch.dissem.bitmessage.entity.payload.V4Pubkey
-import ch.dissem.bitmessage.entity.valueobject.PrivateKey
-import ch.dissem.bitmessage.utils.AccessCounter
-import ch.dissem.bitmessage.utils.Base58
-import ch.dissem.bitmessage.utils.Bytes
-import ch.dissem.bitmessage.utils.Decode.bytes
-import ch.dissem.bitmessage.utils.Decode.varInt
-import ch.dissem.bitmessage.utils.Encode
-import ch.dissem.bitmessage.utils.Singleton.cryptography
-import java.io.ByteArrayInputStream
-import java.io.ByteArrayOutputStream
-import java.io.Serializable
-import java.util.*
-
-/**
- * A Bitmessage address. Can be a user's private address, an address string without public keys or a recipient's address
- * holding private keys.
- */
-class BitmessageAddress : Serializable {
-
-    val version: Long
-    val stream: Long
-    val ripe: ByteArray
-    val tag: ByteArray?
-    /**
-     * The private key used to decrypt Pubkey objects (for v4 addresses) and broadcasts. It's easier to just create
-     * it regardless of address version.
-     */
-    val publicDecryptionKey: ByteArray
-
-    val address: String
-
-    var privateKey: PrivateKey? = null
-        private set
-    var pubkey: Pubkey? = null
-        set(pubkey) {
-            if (pubkey != null) {
-                if (pubkey is V4Pubkey) {
-                    if (!Arrays.equals(tag, pubkey.tag))
-                        throw IllegalArgumentException("Pubkey has incompatible tag")
-                }
-                if (!Arrays.equals(ripe, pubkey.ripe))
-                    throw IllegalArgumentException("Pubkey has incompatible ripe")
-                field = pubkey
-            }
-        }
-
-
-    var alias: String? = null
-    var isSubscribed: Boolean = false
-    var isChan: Boolean = false
-
-    internal constructor(version: Long, stream: Long, ripe: ByteArray) {
-        this.version = version
-        this.stream = stream
-        this.ripe = ripe
-
-        val os = ByteArrayOutputStream()
-        Encode.varInt(version, os)
-        Encode.varInt(stream, os)
-        if (version < 4) {
-            val checksum = cryptography().sha512(os.toByteArray(), ripe)
-            this.tag = null
-            this.publicDecryptionKey = Arrays.copyOfRange(checksum, 0, 32)
-        } else {
-            // for tag and decryption key, the checksum has to be created with 0x00 padding
-            val checksum = cryptography().doubleSha512(os.toByteArray(), ripe)
-            this.tag = Arrays.copyOfRange(checksum, 32, 64)
-            this.publicDecryptionKey = Arrays.copyOfRange(checksum, 0, 32)
-        }
-        // but for the address and its checksum they need to be stripped
-        val offset = Bytes.numberOfLeadingZeros(ripe)
-        os.write(ripe, offset, ripe.size - offset)
-        val checksum = cryptography().doubleSha512(os.toByteArray())
-        os.write(checksum, 0, 4)
-        this.address = "BM-" + Base58.encode(os.toByteArray())
-    }
-
-    constructor(publicKey: Pubkey) : this(publicKey.version, publicKey.stream, publicKey.ripe) {
-        this.pubkey = publicKey
-    }
-
-    constructor(address: String, passphrase: String) : this(address) {
-        val key = PrivateKey(this, passphrase)
-        if (!Arrays.equals(ripe, key.pubkey.ripe)) {
-            throw IllegalArgumentException("Wrong address or passphrase")
-        }
-        this.privateKey = key
-        this.pubkey = key.pubkey
-    }
-
-    constructor(privateKey: PrivateKey) : this(privateKey.pubkey) {
-        this.privateKey = privateKey
-    }
-
-    constructor(address: String) {
-        this.address = address
-        val bytes = Base58.decode(address.substring(3))
-        val input = ByteArrayInputStream(bytes)
-        val counter = AccessCounter()
-        this.version = varInt(input, counter)
-        this.stream = varInt(input, counter)
-        this.ripe = Bytes.expand(bytes(input, bytes.size - counter.length() - 4), 20)
-
-        // test checksum
-        var checksum = cryptography().doubleSha512(bytes, bytes.size - 4)
-        val expectedChecksum = bytes(input, 4)
-        for (i in 0..3) {
-            if (expectedChecksum[i] != checksum[i])
-                throw IllegalArgumentException("Checksum of address failed")
-        }
-        if (version < 4) {
-            checksum = cryptography().sha512(Arrays.copyOfRange(bytes, 0, counter.length()), ripe)
-            this.tag = null
-            this.publicDecryptionKey = Arrays.copyOfRange(checksum, 0, 32)
-        } else {
-            checksum = cryptography().doubleSha512(Arrays.copyOfRange(bytes, 0, counter.length()), ripe)
-            this.tag = Arrays.copyOfRange(checksum, 32, 64)
-            this.publicDecryptionKey = Arrays.copyOfRange(checksum, 0, 32)
-        }
-    }
-
-    override fun toString(): String {
-        return alias ?: address
-    }
-
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (other !is BitmessageAddress) return false
-        return version == other.version &&
-            stream == other.stream &&
-            Arrays.equals(ripe, other.ripe)
-    }
-
-    override fun hashCode(): Int {
-        return Arrays.hashCode(ripe)
-    }
-
-    fun has(feature: Feature?): Boolean {
-        return feature?.isActive(pubkey?.behaviorBitfield ?: 0) ?: false
-    }
-
-    companion object {
-        @JvmStatic fun chan(address: String, passphrase: String): BitmessageAddress {
-            val result = BitmessageAddress(address, passphrase)
-            result.isChan = true
-            return result
-        }
-
-        @JvmStatic fun chan(stream: Long, passphrase: String): BitmessageAddress {
-            val privateKey = PrivateKey(Pubkey.LATEST_VERSION, stream, passphrase)
-            val result = BitmessageAddress(privateKey)
-            result.isChan = true
-            return result
-        }
-
-        @JvmStatic fun deterministic(passphrase: String, numberOfAddresses: Int,
-                                     version: Long, stream: Long, shorter: Boolean): List<BitmessageAddress> {
-            val result = ArrayList<BitmessageAddress>(numberOfAddresses)
-            val privateKeys = PrivateKey.deterministic(passphrase, numberOfAddresses, version, stream, shorter)
-            for (pk in privateKeys) {
-                result.add(BitmessageAddress(pk))
-            }
-            return result
-        }
-
-        @JvmStatic fun calculateTag(version: Long, stream: Long, ripe: ByteArray): ByteArray {
-            val out = ByteArrayOutputStream()
-            Encode.varInt(version, out)
-            Encode.varInt(stream, out)
-            out.write(ripe)
-            return Arrays.copyOfRange(cryptography().doubleSha512(out.toByteArray()), 32, 64)
-        }
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/CustomMessage.kt

@@ -1,86 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.exception.ApplicationException
-import ch.dissem.bitmessage.utils.AccessCounter
-import ch.dissem.bitmessage.utils.Decode.bytes
-import ch.dissem.bitmessage.utils.Decode.varString
-import ch.dissem.bitmessage.utils.Encode
-import java.io.ByteArrayOutputStream
-import java.io.InputStream
-import java.io.OutputStream
-import java.nio.ByteBuffer
-
-/**
- * @author Christian Basler
- */
-open class CustomMessage(val customCommand: String, private val data: ByteArray? = null) : MessagePayload {
-
-    override val command: MessagePayload.Command = MessagePayload.Command.CUSTOM
-
-    val isError = COMMAND_ERROR == customCommand
-
-    fun getData(): ByteArray {
-        return data ?: {
-            val out = ByteArrayOutputStream()
-            writer().write(out)
-            out.toByteArray()
-        }.invoke()
-    }
-
-    override fun writer(): StreamableWriter = Writer(this)
-
-    protected open class Writer(
-        private val item: CustomMessage
-    ) : StreamableWriter {
-
-        override fun write(out: OutputStream) {
-            if (item.data != null) {
-                Encode.varString(item.customCommand, out)
-                out.write(item.data)
-            } else {
-                throw ApplicationException("Tried to write custom message without data. "
-                    + "Programmer: did you forget to override #write()?")
-            }
-        }
-
-        override fun write(buffer: ByteBuffer) {
-            if (item.data != null) {
-                Encode.varString(item.customCommand, buffer)
-                buffer.put(item.data)
-            } else {
-                throw ApplicationException("Tried to write custom message without data. "
-                    + "Programmer: did you forget to override #write()?")
-            }
-        }
-
-    }
-
-    companion object {
-        val COMMAND_ERROR = "ERROR"
-
-        @JvmStatic
-        fun read(input: InputStream, length: Int): CustomMessage {
-            val counter = AccessCounter()
-            return CustomMessage(varString(input, counter), bytes(input, length - counter.length()))
-        }
-
-        @JvmStatic
-        fun error(message: String) = CustomMessage(COMMAND_ERROR, message.toByteArray(charset("UTF-8")))
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/GetData.kt

@@ -1,38 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.entity.valueobject.InventoryVector
-
-/**
- * The 'getdata' command is used to request objects from a node.
- */
-class GetData constructor(var inventory: List<InventoryVector>) : MessagePayload {
-
-    override val command: MessagePayload.Command = MessagePayload.Command.GETDATA
-
-    override fun writer(): StreamableWriter = Writer(this)
-
-    private class Writer(
-        item: GetData
-    ) : InventoryWriter(item.inventory)
-
-    companion object {
-        @JvmField
-        val MAX_INVENTORY_SIZE = 50000
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/Inv.kt

@@ -1,33 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.entity.valueobject.InventoryVector
-
-/**
- * The 'inv' command holds up to 50000 inventory vectors, i.e. hashes of inventory items.
- */
-class Inv constructor(val inventory: List<InventoryVector>) : MessagePayload {
-
-    override val command: MessagePayload.Command = MessagePayload.Command.INV
-
-    override fun writer(): StreamableWriter = Writer(this)
-
-    private class Writer(
-        item: Inv
-    ) : InventoryWriter(item.inventory)
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/InventoryWriter.kt

@@ -1,40 +0,0 @@
-/*
- * Copyright 2018 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.entity.valueobject.InventoryVector
-import ch.dissem.bitmessage.utils.Encode
-import java.io.OutputStream
-import java.nio.ByteBuffer
-
-internal open class InventoryWriter(private val inventory: List<InventoryVector>) : StreamableWriter {
-
-    override fun write(out: OutputStream) {
-        Encode.varInt(inventory.size, out)
-        for (iv in inventory) {
-            iv.writer().write(out)
-        }
-    }
-
-    override fun write(buffer: ByteBuffer) {
-        Encode.varInt(inventory.size, buffer)
-        for (iv in inventory) {
-            iv.writer().write(buffer)
-        }
-    }
-
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/NetworkMessage.kt

@@ -1,132 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.utils.Encode
-import ch.dissem.bitmessage.utils.Singleton.cryptography
-import java.io.OutputStream
-import java.nio.ByteBuffer
-
-/**
- * A network message is exchanged between two nodes.
- */
-data class NetworkMessage(
-    /**
-     * The actual data, a message or an object. Not to be confused with objectPayload.
-     */
-    val payload: MessagePayload
-) : Streamable {
-
-    override fun writer(): Writer = Writer(this)
-
-    class Writer internal constructor(
-        private val item: NetworkMessage
-    ) : StreamableWriter {
-
-        override fun write(out: OutputStream) {
-            // magic
-            Encode.int32(MAGIC, out)
-
-            // ASCII string identifying the packet content, NULL padded (non-NULL padding results in packet rejected)
-            val command = item.payload.command.name.toLowerCase()
-            out.write(command.toByteArray(charset("ASCII")))
-            for (i in command.length..11) {
-                out.write(0x0)
-            }
-
-            val payloadBytes = Encode.bytes(item.payload)
-
-            // Length of payload in number of bytes. Because of other restrictions, there is no reason why this length would
-            // ever be larger than 1600003 bytes. Some clients include a sanity-check to avoid processing messages which are
-            // larger than this.
-            Encode.int32(payloadBytes.size, out)
-
-            // checksum
-            out.write(getChecksum(payloadBytes))
-
-            // message payload
-            out.write(payloadBytes)
-        }
-
-        /**
-         * A more efficient implementation of the write method, writing header data to the provided buffer and returning
-         * a new buffer containing the payload.
-
-         * @param headerBuffer where the header data is written to (24 bytes)
-         * *
-         * @return a buffer containing the payload, ready to be read.
-         */
-        fun writeHeaderAndGetPayloadBuffer(headerBuffer: ByteBuffer): ByteBuffer {
-            return ByteBuffer.wrap(writeHeader(headerBuffer))
-        }
-
-        /**
-         * For improved memory efficiency, you should use [.writeHeaderAndGetPayloadBuffer]
-         * and write the header buffer as well as the returned payload buffer into the channel.
-
-         * @param buffer where everything gets written to. Needs to be large enough for the whole message
-         * *               to be written.
-         */
-        override fun write(buffer: ByteBuffer) {
-            val payloadBytes = writeHeader(buffer)
-            buffer.put(payloadBytes)
-        }
-
-        private fun writeHeader(out: ByteBuffer): ByteArray {
-            // magic
-            Encode.int32(MAGIC, out)
-
-            // ASCII string identifying the packet content, NULL padded (non-NULL padding results in packet rejected)
-            val command = item.payload.command.name.toLowerCase()
-            out.put(command.toByteArray(charset("ASCII")))
-
-            for (i in command.length..11) {
-                out.put(0.toByte())
-            }
-
-            val payloadBytes = Encode.bytes(item.payload)
-
-            // Length of payload in number of bytes. Because of other restrictions, there is no reason why this length would
-            // ever be larger than 1600003 bytes. Some clients include a sanity-check to avoid processing messages which are
-            // larger than this.
-            Encode.int32(payloadBytes.size, out)
-
-            // checksum
-            out.put(getChecksum(payloadBytes))
-
-            // message payload
-            return payloadBytes
-        }
-
-        /**
-         * First 4 bytes of sha512(payload)
-         */
-        private fun getChecksum(bytes: ByteArray): ByteArray {
-            val d = cryptography().sha512(bytes)
-            return byteArrayOf(d[0], d[1], d[2], d[3])
-        }
-
-    }
-
-    companion object {
-        /**
-         * Magic value indicating message origin network, and used to seek to next message when stream state is unknown
-         */
-        val MAGIC = 0xE9BEB4D9.toInt()
-        val MAGIC_BYTES = ByteBuffer.allocate(4).putInt(MAGIC).array()
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/ObjectMessage.kt

@@ -1,227 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.entity.payload.ObjectPayload
-import ch.dissem.bitmessage.entity.payload.ObjectType
-import ch.dissem.bitmessage.entity.payload.Pubkey
-import ch.dissem.bitmessage.entity.valueobject.InventoryVector
-import ch.dissem.bitmessage.entity.valueobject.PrivateKey
-import ch.dissem.bitmessage.exception.ApplicationException
-import ch.dissem.bitmessage.exception.DecryptionFailedException
-import ch.dissem.bitmessage.utils.Bytes
-import ch.dissem.bitmessage.utils.Encode
-import ch.dissem.bitmessage.utils.Singleton.cryptography
-import java.io.ByteArrayOutputStream
-import java.io.IOException
-import java.io.OutputStream
-import java.nio.ByteBuffer
-import java.util.*
-
-/**
- * The 'object' command sends an object that is shared throughout the network.
- */
-data class ObjectMessage(
-    var nonce: ByteArray? = null,
-    val expiresTime: Long,
-    val payload: ObjectPayload,
-    val type: Long = payload.type?.number ?: throw IllegalArgumentException("payload must have type defined"),
-    /**
-     * The object's version
-     */
-    val version: Long = payload.version,
-    val stream: Long = payload.stream
-) : MessagePayload {
-
-    override val command: MessagePayload.Command = MessagePayload.Command.OBJECT
-
-    val inventoryVector: InventoryVector
-        get() {
-            return InventoryVector(
-                Bytes.truncate(
-                    cryptography().doubleSha512(
-                        nonce ?: throw IllegalStateException("nonce must be set"),
-                        payloadBytesWithoutNonce
-                    ), 32
-                )
-            )
-        }
-
-    private val isEncrypted: Boolean
-        get() = payload is Encrypted && !payload.isDecrypted
-
-    val isSigned: Boolean
-        get() = payload.isSigned
-
-    private val bytesToSign: ByteArray
-        get() {
-            try {
-                val out = ByteArrayOutputStream()
-                writer.writeHeaderWithoutNonce(out)
-                payload.writer().writeBytesToSign(out)
-                return out.toByteArray()
-            } catch (e: IOException) {
-                throw ApplicationException(e)
-            }
-        }
-
-    fun sign(key: PrivateKey) {
-        if (payload.isSigned) {
-            payload.signature = cryptography().getSignature(bytesToSign, key)
-        }
-    }
-
-    @Throws(DecryptionFailedException::class)
-    fun decrypt(key: PrivateKey) {
-        if (payload is Encrypted) {
-            payload.decrypt(key.privateEncryptionKey)
-        }
-    }
-
-    @Throws(DecryptionFailedException::class)
-    fun decrypt(privateEncryptionKey: ByteArray) {
-        if (payload is Encrypted) {
-            payload.decrypt(privateEncryptionKey)
-        }
-    }
-
-    fun encrypt(publicEncryptionKey: ByteArray) {
-        if (payload is Encrypted) {
-            payload.encrypt(publicEncryptionKey)
-        }
-    }
-
-    fun encrypt(publicKey: Pubkey) {
-        try {
-            if (payload is Encrypted) {
-                payload.encrypt(publicKey.encryptionKey)
-            }
-        } catch (e: IOException) {
-            throw ApplicationException(e)
-        }
-
-    }
-
-    fun isSignatureValid(pubkey: Pubkey): Boolean {
-        if (isEncrypted) throw IllegalStateException("Payload must be decrypted first")
-        return cryptography().isSignatureValid(bytesToSign, payload.signature ?: return false, pubkey)
-    }
-
-    val payloadBytesWithoutNonce: ByteArray by lazy {
-        val out = ByteArrayOutputStream()
-        writer.writeHeaderWithoutNonce(out)
-        payload.writer().write(out)
-        out.toByteArray()
-    }
-
-    private val writer = Writer(this)
-    override fun writer(): StreamableWriter = writer
-
-    private class Writer(
-        private val item: ObjectMessage
-    ) : StreamableWriter {
-
-        override fun write(out: OutputStream) {
-            out.write(item.nonce ?: ByteArray(8))
-            out.write(item.payloadBytesWithoutNonce)
-        }
-
-        override fun write(buffer: ByteBuffer) {
-            buffer.put(item.nonce ?: ByteArray(8))
-            buffer.put(item.payloadBytesWithoutNonce)
-        }
-
-        internal fun writeHeaderWithoutNonce(out: OutputStream) {
-            Encode.int64(item.expiresTime, out)
-            Encode.int32(item.type, out)
-            Encode.varInt(item.version, out)
-            Encode.varInt(item.stream, out)
-        }
-
-    }
-
-    class Builder {
-        private var nonce: ByteArray? = null
-        private var expiresTime: Long = 0
-        private var objectType: Long? = null
-        private var streamNumber: Long = 0
-        private var payload: ObjectPayload? = null
-
-        fun nonce(nonce: ByteArray): Builder {
-            this.nonce = nonce
-            return this
-        }
-
-        fun expiresTime(expiresTime: Long): Builder {
-            this.expiresTime = expiresTime
-            return this
-        }
-
-        fun objectType(objectType: Long): Builder {
-            this.objectType = objectType
-            return this
-        }
-
-        fun objectType(objectType: ObjectType): Builder {
-            this.objectType = objectType.number
-            return this
-        }
-
-        fun stream(streamNumber: Long): Builder {
-            this.streamNumber = streamNumber
-            return this
-        }
-
-        fun payload(payload: ObjectPayload): Builder {
-            this.payload = payload
-            if (this.objectType == null)
-                this.objectType = payload.type?.number
-            return this
-        }
-
-        fun build(): ObjectMessage {
-            return ObjectMessage(
-                nonce = nonce,
-                expiresTime = expiresTime,
-                type = objectType!!,
-                version = payload!!.version,
-                stream = if (streamNumber > 0) streamNumber else payload!!.stream,
-                payload = payload!!
-            )
-        }
-    }
-
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (other !is ObjectMessage) return false
-        return expiresTime == other.expiresTime &&
-            type == other.type &&
-            version == other.version &&
-            stream == other.stream &&
-            payload == other.payload
-    }
-
-    override fun hashCode(): Int {
-        var result = Arrays.hashCode(nonce)
-        result = 31 * result + (expiresTime xor expiresTime.ushr(32)).toInt()
-        result = 31 * result + (type xor type.ushr(32)).toInt()
-        result = 31 * result + (version xor version.ushr(32)).toInt()
-        result = 31 * result + (stream xor stream.ushr(32)).toInt()
-        result = 31 * result + (payload.hashCode())
-        return result
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/Plaintext.kt

@@ -1,832 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.entity.Plaintext.Encoding.*
-import ch.dissem.bitmessage.entity.Plaintext.Type.MSG
-import ch.dissem.bitmessage.entity.payload.Msg
-import ch.dissem.bitmessage.entity.payload.Pubkey.Feature
-import ch.dissem.bitmessage.entity.valueobject.ExtendedEncoding
-import ch.dissem.bitmessage.entity.valueobject.InventoryVector
-import ch.dissem.bitmessage.entity.valueobject.Label
-import ch.dissem.bitmessage.entity.valueobject.extended.Attachment
-import ch.dissem.bitmessage.entity.valueobject.extended.Message
-import ch.dissem.bitmessage.exception.ApplicationException
-import ch.dissem.bitmessage.factory.ExtendedEncodingFactory
-import ch.dissem.bitmessage.factory.Factory
-import ch.dissem.bitmessage.utils.*
-import ch.dissem.bitmessage.utils.Singleton.cryptography
-import java.io.*
-import java.nio.ByteBuffer
-import java.util.*
-import java.util.Collections
-import kotlin.collections.HashSet
-import kotlin.collections.LinkedHashSet
-
-private fun message(encoding: Plaintext.Encoding, subject: String, body: String): ByteArray = when (encoding) {
-    SIMPLE -> "Subject:$subject\nBody:$body".toByteArray()
-    EXTENDED -> Message.Builder().subject(subject).body(body).build().zip()
-    TRIVIAL -> (subject + body).toByteArray()
-    IGNORE -> ByteArray(0)
-}
-
-private fun ackData(type: Plaintext.Type, ackData: ByteArray?): ByteArray? {
-    if (ackData != null) {
-        return ackData
-    } else if (type == MSG) {
-        return cryptography().randomBytes(Msg.ACK_LENGTH)
-    } else {
-        return null
-    }
-}
-
-/**
- * A plaintext message before encryption or after decryption.
- */
-class Plaintext private constructor(
-    val type: Type,
-    val from: BitmessageAddress,
-    to: BitmessageAddress?,
-    val encodingCode: Long,
-    val message: ByteArray,
-    val ackData: ByteArray?,
-    ackMessage: Lazy<ObjectMessage?> = lazy { Factory.createAck(from, ackData, ttl) },
-    var conversationId: UUID = UUID.randomUUID(),
-    var inventoryVector: InventoryVector? = null,
-    var signature: ByteArray? = null,
-    sent: Long? = null,
-    val received: Long? = null,
-    var initialHash: ByteArray? = null,
-    ttl: Long = TTL.msg,
-    val labels: MutableSet<Label> = HashSet(),
-    status: Status
-) : Streamable {
-
-    var id: Any? = null
-        set(id) {
-            if (this.id != null) throw IllegalStateException("ID already set")
-            field = id
-        }
-
-    var to: BitmessageAddress? = to
-        set(to) {
-            if (to == null) {
-                return
-            }
-            this.to?.let {
-                if (it.version != 0L)
-                    throw IllegalStateException("Correct address already set")
-                if (!Arrays.equals(it.ripe, to.ripe)) {
-                    throw IllegalArgumentException("RIPEs don't match")
-                }
-            }
-            field = to
-        }
-
-    val stream: Long
-        get() = to?.stream ?: from.stream
-
-    val extendedData: ExtendedEncoding? by lazy {
-        if (encodingCode == EXTENDED.code) {
-            ExtendedEncodingFactory.unzip(message)
-        } else {
-            null
-        }
-    }
-
-    val ackMessage: ObjectMessage? by ackMessage
-
-    var status: Status = status
-        set(status) {
-            if (status != Status.RECEIVED && sent == null && status != Status.DRAFT) {
-                sent = UnixTime.now
-            }
-            field = status
-        }
-
-    val encoding: Encoding? by lazy { Encoding.fromCode(encodingCode) }
-    var sent: Long? = sent
-        private set
-    var retries: Int = 0
-        private set
-    var nextTry: Long? = null
-        private set
-    val ttl: Long = ttl
-        @JvmName("getTTL") get
-
-    constructor(
-        type: Type,
-        from: BitmessageAddress,
-        to: BitmessageAddress?,
-        encoding: Encoding,
-        message: ByteArray,
-        ackData: ByteArray? = null,
-        conversationId: UUID = UUID.randomUUID(),
-        inventoryVector: InventoryVector? = null,
-        signature: ByteArray? = null,
-        received: Long? = null,
-        initialHash: ByteArray? = null,
-        ttl: Long = TTL.msg,
-        labels: MutableSet<Label> = HashSet(),
-        status: Status
-    ) : this(
-        type = type,
-        from = from,
-        to = to,
-        encodingCode = encoding.code,
-        message = message,
-        ackData = ackData(type, ackData),
-        conversationId = conversationId,
-        inventoryVector = inventoryVector,
-        signature = signature,
-        received = received,
-        initialHash = initialHash,
-        ttl = ttl,
-        labels = labels,
-        status = status
-    )
-
-    constructor(
-        type: Type,
-        from: BitmessageAddress,
-        to: BitmessageAddress?,
-        encoding: Long,
-        message: ByteArray,
-        ackMessage: ByteArray?,
-        conversationId: UUID = UUID.randomUUID(),
-        inventoryVector: InventoryVector? = null,
-        signature: ByteArray? = null,
-        received: Long? = null,
-        initialHash: ByteArray? = null,
-        ttl: Long = TTL.msg,
-        labels: MutableSet<Label> = HashSet(),
-        status: Status
-    ) : this(
-        type = type,
-        from = from,
-        to = to,
-        encodingCode = encoding,
-        message = message,
-        ackData = null,
-        ackMessage = lazy {
-            if (ackMessage != null && ackMessage.isNotEmpty()) {
-                Factory.getObjectMessage(
-                    3,
-                    ByteArrayInputStream(ackMessage),
-                    ackMessage.size
-                )
-            } else null
-        },
-        conversationId = conversationId,
-        inventoryVector = inventoryVector,
-        signature = signature,
-        received = received,
-        initialHash = initialHash,
-        ttl = ttl,
-        labels = labels,
-        status = status
-    )
-
-    constructor(
-        type: Type,
-        from: BitmessageAddress,
-        to: BitmessageAddress? = null,
-        encoding: Encoding = SIMPLE,
-        subject: String,
-        body: String,
-        ackData: ByteArray? = null,
-        conversationId: UUID = UUID.randomUUID(),
-        ttl: Long = TTL.msg,
-        labels: MutableSet<Label> = HashSet(),
-        status: Status = Status.DRAFT
-    ) : this(
-        type = type,
-        from = from,
-        to = to,
-        encoding = encoding,
-        message = message(encoding, subject, body),
-        ackData = ackData(type, ackData),
-        conversationId = conversationId,
-        inventoryVector = null,
-        signature = null,
-        received = null,
-        initialHash = null,
-        ttl = ttl,
-        labels = labels,
-        status = status
-    )
-
-    constructor(builder: Builder) : this(
-        // Calling prepare() here is somewhat ugly, but also a foolproof way to make sure the builder is properly initialized
-        type = builder.prepare().type,
-        from = builder.from ?: throw IllegalStateException("sender identity not set"),
-        to = builder.to,
-        encodingCode = builder.encoding,
-        message = builder.message,
-        ackData = builder.ackData,
-        ackMessage = lazy {
-            val ackMsg = builder.ackMessage
-            if (ackMsg != null && ackMsg.isNotEmpty()) {
-                Factory.getObjectMessage(
-                    3,
-                    ByteArrayInputStream(ackMsg),
-                    ackMsg.size
-                )
-            } else {
-                Factory.createAck(builder.from!!, builder.ackData, builder.ttl)
-            }
-        },
-        conversationId = builder.conversation ?: UUID.randomUUID(),
-        inventoryVector = builder.inventoryVector,
-        signature = builder.signature,
-        sent = builder.sent,
-        received = builder.received,
-        initialHash = null,
-        ttl = builder.ttl,
-        labels = LinkedHashSet(builder.labels),
-        status = builder.status ?: Status.RECEIVED
-    ) {
-        id = builder.id
-    }
-
-    fun updateNextTry() {
-        if (to != null) {
-            if (nextTry == null) {
-                if (sent != null && to!!.has(Feature.DOES_ACK)) {
-                    nextTry = UnixTime.now + ttl
-                    retries++
-                }
-            } else {
-                nextTry = nextTry!! + (1 shl retries) * ttl
-                retries++
-            }
-        }
-    }
-
-    val subject: String?
-        get() {
-            val s = Scanner(ByteArrayInputStream(message), "UTF-8")
-            val firstLine = s.nextLine()
-            return when (encodingCode) {
-                EXTENDED.code -> if (Message.TYPE == extendedData?.type) {
-                    (extendedData!!.content as? Message)?.subject
-                } else {
-                    null
-                }
-                SIMPLE.code -> firstLine.substring("Subject:".length).trim { it <= ' ' }
-                else -> {
-                    if (firstLine.length > 50) {
-                        firstLine.substring(0, 50).trim { it <= ' ' } + "..."
-                    } else {
-                        firstLine
-                    }
-                }
-            }
-        }
-
-    val text: String?
-        get() {
-            if (encodingCode == EXTENDED.code) {
-                return if (Message.TYPE == extendedData?.type) {
-                    (extendedData?.content as Message?)?.body
-                } else {
-                    null
-                }
-            } else {
-                val text = String(message)
-                if (encodingCode == SIMPLE.code) {
-                    return text.substring(text.indexOf("\nBody:") + 6)
-                }
-                return text
-            }
-        }
-
-    fun <T : ExtendedEncoding.ExtendedType> getExtendedData(type: Class<T>): T? {
-        val extendedData = extendedData ?: return null
-        if (type.isInstance(extendedData.content)) {
-            @Suppress("UNCHECKED_CAST")
-            return extendedData.content as T
-        }
-        return null
-    }
-
-    val parents: List<InventoryVector>
-        get() {
-            val extendedData = extendedData ?: return emptyList()
-            return if (Message.TYPE == extendedData.type) {
-                (extendedData.content as Message).parents
-            } else {
-                emptyList()
-            }
-        }
-
-    val files: List<Attachment>
-        get() {
-            val extendedData = extendedData ?: return emptyList()
-            return if (Message.TYPE == extendedData.type) {
-                (extendedData.content as Message).files
-            } else {
-                emptyList()
-            }
-        }
-
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (other !is Plaintext) return false
-        return encoding == other.encoding &&
-            from.address == other.from.address &&
-            Arrays.equals(message, other.message) &&
-            ackMessage == other.ackMessage &&
-            Arrays.equals(to?.ripe, other.to?.ripe) &&
-            Arrays.equals(signature, other.signature) &&
-            status == other.status &&
-            sent == other.sent &&
-            received == other.received &&
-            labels == other.labels
-    }
-
-    override fun hashCode(): Int {
-        return Objects.hash(from, encoding, message, ackData, to, signature, status, sent, received, labels)
-    }
-
-    fun addLabels(vararg labels: Label) {
-        Collections.addAll(this.labels, *labels)
-    }
-
-    fun addLabels(labels: Collection<Label>?) {
-        if (labels != null) {
-            this.labels.addAll(labels)
-        }
-    }
-
-    fun removeLabel(type: Label.Type) {
-        labels.removeAll { it.type == type }
-    }
-
-    fun isUnread(): Boolean {
-        return labels.any { it.type == Label.Type.UNREAD }
-    }
-
-    override fun toString(): String {
-        val subject = subject
-        if (subject?.isNotEmpty() == true) {
-            return subject
-        } else {
-            return Strings.hex(
-                initialHash ?: return super.toString()
-            )
-        }
-    }
-
-    enum class Encoding constructor(code: Long) {
-
-        IGNORE(0), TRIVIAL(1), SIMPLE(2), EXTENDED(3);
-
-        var code: Long = 0
-            internal set
-
-        init {
-            this.code = code
-        }
-
-        companion object {
-
-            @JvmStatic
-            fun fromCode(code: Long): Encoding? {
-                for (e in values()) {
-                    if (e.code == code) {
-                        return e
-                    }
-                }
-                return null
-            }
-
-        }
-    }
-
-    enum class Status {
-
-        DRAFT,
-        PUBKEY_REQUESTED,
-        DOING_PROOF_OF_WORK,
-        SENT,
-        SENT_ACKNOWLEDGED,
-        RECEIVED
-    }
-
-    enum class Type {
-
-        MSG, BROADCAST
-    }
-
-    fun writer(includeSignature: Boolean): StreamableWriter = Writer(this, includeSignature)
-
-    override fun writer(): StreamableWriter = Writer(this)
-
-    private class Writer(
-        private val item: Plaintext,
-        private val includeSignature: Boolean = true
-    ) : StreamableWriter {
-
-        override fun write(out: OutputStream) {
-            Encode.varInt(item.from.version, out)
-            Encode.varInt(item.from.stream, out)
-            item.from.pubkey?.apply {
-                Encode.int32(behaviorBitfield, out)
-                out.write(signingKey, 1, 64)
-                out.write(encryptionKey, 1, 64)
-                if (item.from.version >= 3) {
-                    Encode.varInt(nonceTrialsPerByte, out)
-                    Encode.varInt(extraBytes, out)
-                }
-            } ?: {
-                Encode.int32(0, out)
-                val empty = ByteArray(64)
-                out.write(empty)
-                out.write(empty)
-                if (item.from.version >= 3) {
-                    Encode.varInt(0, out)
-                    Encode.varInt(0, out)
-                }
-            }.invoke()
-            if (item.type == MSG) {
-                // A draft without recipient is allowed, therefore this workaround.
-                item.to?.let { out.write(it.ripe) } ?: if (item.status == Status.DRAFT) {
-                    out.write(ByteArray(20))
-                } else {
-                    throw IllegalStateException("No recipient set for message")
-                }
-            }
-            Encode.varInt(item.encodingCode, out)
-            Encode.varInt(item.message.size, out)
-            out.write(item.message)
-            if (item.type == MSG) {
-                if (item.to?.has(Feature.DOES_ACK) == true) {
-                    val ack = ByteArrayOutputStream()
-                    item.ackMessage?.writer()?.write(ack)
-                    Encode.varBytes(ack.toByteArray(), out)
-                } else {
-                    Encode.varInt(0, out)
-                }
-            }
-            if (includeSignature) {
-                val sig = item.signature
-                if (sig == null) {
-                    Encode.varInt(0, out)
-                } else {
-                    Encode.varBytes(sig, out)
-                }
-            }
-        }
-
-        override fun write(buffer: ByteBuffer) {
-            Encode.varInt(item.from.version, buffer)
-            Encode.varInt(item.from.stream, buffer)
-            if (item.from.pubkey == null) {
-                Encode.int32(0, buffer)
-                val empty = ByteArray(64)
-                buffer.put(empty)
-                buffer.put(empty)
-                if (item.from.version >= 3) {
-                    Encode.varInt(0, buffer)
-                    Encode.varInt(0, buffer)
-                }
-            } else {
-                Encode.int32(item.from.pubkey!!.behaviorBitfield, buffer)
-                buffer.put(item.from.pubkey!!.signingKey, 1, 64)
-                buffer.put(item.from.pubkey!!.encryptionKey, 1, 64)
-                if (item.from.version >= 3) {
-                    Encode.varInt(item.from.pubkey!!.nonceTrialsPerByte, buffer)
-                    Encode.varInt(item.from.pubkey!!.extraBytes, buffer)
-                }
-            }
-            if (item.type == MSG) {
-                // A draft without recipient is allowed, therefore this workaround.
-                item.to?.let { buffer.put(it.ripe) } ?: if (item.status == Status.DRAFT) {
-                    buffer.put(ByteArray(20))
-                } else {
-                    throw IllegalStateException("No recipient set for message")
-                }
-            }
-            Encode.varInt(item.encodingCode, buffer)
-            Encode.varBytes(item.message, buffer)
-            if (item.type == MSG) {
-                if (item.to!!.has(Feature.DOES_ACK) && item.ackMessage != null) {
-                    Encode.varBytes(Encode.bytes(item.ackMessage!!), buffer)
-                } else {
-                    Encode.varInt(0, buffer)
-                }
-            }
-            if (includeSignature) {
-                val sig = item.signature
-                if (sig == null) {
-                    Encode.varInt(0, buffer)
-                } else {
-                    Encode.varBytes(sig, buffer)
-                }
-            }
-        }
-
-    }
-
-    class Builder(internal val type: Type) {
-        var id: Any? = null
-        var inventoryVector: InventoryVector? = null
-        var from: BitmessageAddress? = null
-        var to: BitmessageAddress? = null
-            set(value) {
-                if (value != null) {
-                    if (type != MSG && to != null)
-                        throw IllegalArgumentException("recipient address only allowed for msg")
-                    field = value
-                }
-            }
-        var addressVersion: Long = 0
-        var stream: Long = 0
-        var behaviorBitfield: Int = 0
-        var publicSigningKey: ByteArray? = null
-        var publicEncryptionKey: ByteArray? = null
-        var nonceTrialsPerByte: Long = 0
-        var extraBytes: Long = 0
-        var destinationRipe: ByteArray? = null
-            set(value) {
-                if (type != MSG && value != null) throw IllegalArgumentException("ripe only allowed for msg")
-                field = value
-            }
-        var preventAck: Boolean = false
-        var encoding: Long = 0
-        var message = ByteArray(0)
-        var ackData: ByteArray? = null
-        var ackMessage: ByteArray? = null
-        var signature: ByteArray? = null
-        var sent: Long? = null
-        var received: Long? = null
-        var status: Status? = null
-        var labels: Collection<Label> = emptySet()
-        var ttl: Long = 0
-        var retries: Int = 0
-        var nextTry: Long? = null
-        var conversation: UUID? = null
-
-        fun id(id: Any): Builder {
-            this.id = id
-            return this
-        }
-
-        fun IV(iv: InventoryVector?): Builder {
-            this.inventoryVector = iv
-            return this
-        }
-
-        fun from(address: BitmessageAddress): Builder {
-            from = address
-            return this
-        }
-
-        fun to(address: BitmessageAddress?): Builder {
-            to = address
-            return this
-        }
-
-        fun addressVersion(addressVersion: Long): Builder {
-            this.addressVersion = addressVersion
-            return this
-        }
-
-        fun stream(stream: Long): Builder {
-            this.stream = stream
-            return this
-        }
-
-        fun behaviorBitfield(behaviorBitfield: Int): Builder {
-            this.behaviorBitfield = behaviorBitfield
-            return this
-        }
-
-        fun publicSigningKey(publicSigningKey: ByteArray): Builder {
-            this.publicSigningKey = publicSigningKey
-            return this
-        }
-
-        fun publicEncryptionKey(publicEncryptionKey: ByteArray): Builder {
-            this.publicEncryptionKey = publicEncryptionKey
-            return this
-        }
-
-        fun nonceTrialsPerByte(nonceTrialsPerByte: Long): Builder {
-            this.nonceTrialsPerByte = nonceTrialsPerByte
-            return this
-        }
-
-        fun extraBytes(extraBytes: Long): Builder {
-            this.extraBytes = extraBytes
-            return this
-        }
-
-        fun destinationRipe(ripe: ByteArray?): Builder {
-            this.destinationRipe = ripe
-            return this
-        }
-
-        @JvmOverloads
-        fun preventAck(preventAck: Boolean = true): Builder {
-            this.preventAck = preventAck
-            return this
-        }
-
-        fun encoding(encoding: Encoding): Builder {
-            this.encoding = encoding.code
-            return this
-        }
-
-        fun encoding(encoding: Long): Builder {
-            this.encoding = encoding
-            return this
-        }
-
-        fun message(message: ExtendedEncoding): Builder {
-            this.encoding = EXTENDED.code
-            this.message = message.zip()
-            return this
-        }
-
-        fun message(subject: String, message: String): Builder {
-            try {
-                this.encoding = SIMPLE.code
-                this.message = "Subject:$subject\nBody:$message".toByteArray(charset("UTF-8"))
-            } catch (e: UnsupportedEncodingException) {
-                throw ApplicationException(e)
-            }
-            return this
-        }
-
-        fun message(message: ByteArray): Builder {
-            this.message = message
-            return this
-        }
-
-        fun ackMessage(ack: ByteArray?): Builder {
-            if (type != MSG && ack != null) throw IllegalArgumentException("ackMessage only allowed for msg")
-            this.ackMessage = ack
-            return this
-        }
-
-        fun ackData(ackData: ByteArray?): Builder {
-            if (type != MSG && ackData != null)
-                throw IllegalArgumentException("ackMessage only allowed for msg")
-            this.ackData = ackData
-            return this
-        }
-
-        fun signature(signature: ByteArray?): Builder {
-            this.signature = signature
-            return this
-        }
-
-        fun sent(sent: Long?): Builder {
-            this.sent = sent
-            return this
-        }
-
-        fun received(received: Long?): Builder {
-            this.received = received
-            return this
-        }
-
-        fun status(status: Status): Builder {
-            this.status = status
-            return this
-        }
-
-        fun labels(labels: Collection<Label>): Builder {
-            this.labels = labels
-            return this
-        }
-
-        fun ttl(ttl: Long): Builder {
-            this.ttl = ttl
-            return this
-        }
-
-        fun retries(retries: Int): Builder {
-            this.retries = retries
-            return this
-        }
-
-        fun nextTry(nextTry: Long?): Builder {
-            this.nextTry = nextTry
-            return this
-        }
-
-        fun conversation(id: UUID): Builder {
-            this.conversation = id
-            return this
-        }
-
-        internal fun prepare(): Builder {
-            if (from == null) {
-                from = BitmessageAddress(
-                    Factory.createPubkey(
-                        addressVersion,
-                        stream,
-                        publicSigningKey!!,
-                        publicEncryptionKey!!,
-                        nonceTrialsPerByte,
-                        extraBytes,
-                        behaviorBitfield
-                    )
-                )
-            }
-            if (to == null && type != Type.BROADCAST && destinationRipe != null) {
-                to = BitmessageAddress(0, 0, destinationRipe!!)
-            }
-            if (preventAck) {
-                ackData = null
-                ackMessage = null
-            } else if (type == MSG && ackMessage == null && ackData == null && to?.has(Feature.DOES_ACK) == true) {
-                ackData = cryptography().randomBytes(Msg.ACK_LENGTH)
-            }
-            if (ttl <= 0) {
-                ttl = TTL.msg
-            }
-            return this
-        }
-
-        @JvmSynthetic
-        inline fun build(block: Builder.() -> Unit): Plaintext {
-            block(this)
-            return build()
-        }
-
-        fun build(): Plaintext {
-            return Plaintext(this)
-        }
-    }
-
-    companion object {
-
-        @JvmStatic
-        fun read(type: Type, input: InputStream): Plaintext {
-            return readWithoutSignature(type, input)
-                .signature(Decode.varBytes(input))
-                .received(UnixTime.now)
-                .build()
-        }
-
-        @JvmStatic
-        fun readWithoutSignature(type: Type, input: InputStream): Plaintext.Builder {
-            val version = Decode.varInt(input)
-            return Builder(type)
-                .addressVersion(version)
-                .stream(Decode.varInt(input))
-                .behaviorBitfield(Decode.int32(input))
-                .publicSigningKey(Decode.bytes(input, 64))
-                .publicEncryptionKey(Decode.bytes(input, 64))
-                .nonceTrialsPerByte(if (version >= 3) Decode.varInt(input) else 0)
-                .extraBytes(if (version >= 3) Decode.varInt(input) else 0)
-                .destinationRipe(if (type == MSG) Decode.bytes(input, 20).let {
-                    if (it.any { x -> x != 0.toByte() }) it else null
-                } else null)
-                .encoding(Decode.varInt(input))
-                .message(Decode.varBytes(input))
-                .ackMessage(if (type == MSG) Decode.varBytes(input) else null)
-        }
-
-        @JvmSynthetic
-        inline fun build(type: Type, block: Builder.() -> Unit): Plaintext {
-            val builder = Builder(type)
-            block(builder)
-            return builder.build()
-        }
-
-    }
-}
-
-data class Conversation(val id: UUID, val subject: String, val messages: List<Plaintext>) : Serializable {
-    val participants = messages
-        .map { it.from }
-        .filter { it.privateKey == null || it.isChan }
-        .distinct()
-
-    val extract: String by lazy {
-        messages.firstOrNull { m -> m.labels.any { l -> l.type==Label.Type.UNREAD } }?.text
-            ?: messages.lastOrNull()?.text
-            ?: ""
-    }
-
-    fun hasUnread() = messages.any { it.isUnread() }
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/Streamable.kt

@@ -1,50 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import java.io.OutputStream
-import java.io.Serializable
-import java.nio.ByteBuffer
-
-/**
- * An object that can be written to an [OutputStream]
- */
-interface Streamable : Serializable {
-    fun writer(): StreamableWriter
-}
-
-interface SignedStreamable : Streamable {
-    override fun writer(): SignedStreamableWriter
-}
-
-interface EncryptedStreamable : SignedStreamable {
-    override fun writer(): EncryptedStreamableWriter
-}
-
-interface StreamableWriter: Serializable {
-    fun write(out: OutputStream)
-    fun write(buffer: ByteBuffer)
-}
-
-interface SignedStreamableWriter : StreamableWriter {
-    fun writeBytesToSign(out: OutputStream)
-}
-
-interface EncryptedStreamableWriter : SignedStreamableWriter {
-    fun writeUnencrypted(out: OutputStream)
-    fun writeUnencrypted(buffer: ByteBuffer)
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/Version.kt

@@ -1,206 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity
-
-import ch.dissem.bitmessage.BitmessageContext
-import ch.dissem.bitmessage.entity.valueobject.NetworkAddress
-import ch.dissem.bitmessage.utils.Encode
-import ch.dissem.bitmessage.utils.UnixTime
-import java.io.OutputStream
-import java.nio.ByteBuffer
-
-/**
- * The 'version' command advertises this node's latest supported protocol version upon initiation.
- */
-class Version constructor(
-    /**
-     * Identifies protocol version being used by the node. Should equal 3. Nodes should disconnect if the remote node's
-     * version is lower but continue with the connection if it is higher.
-     */
-    val version: Int = BitmessageContext.CURRENT_VERSION,
-
-    /**
-     * bitfield of features to be enabled for this connection
-     */
-    val services: Long = Version.Service.getServiceFlag(Version.Service.NODE_NETWORK),
-
-    /**
-     * standard UNIX timestamp in seconds
-     */
-    val timestamp: Long = UnixTime.now,
-
-    /**
-     * The network address of the node receiving this message (not including the time or stream number)
-     */
-    val addrRecv: NetworkAddress,
-
-    /**
-     * The network address of the node emitting this message (not including the time or stream number and the ip itself
-     * is ignored by the receiver)
-     */
-    val addrFrom: NetworkAddress,
-
-    /**
-     * Random nonce used to detect connections to self.
-     */
-    val nonce: Long,
-
-    /**
-     * User Agent (0x00 if string is 0 bytes long). Sending nodes must not include a user_agent longer than 5000 bytes.
-     */
-    val userAgent: String,
-
-    /**
-     * The stream numbers that the emitting node is interested in. Sending nodes must not include more than 160000
-     * stream numbers.
-     */
-    val streams: LongArray = longArrayOf(1)
-) : MessagePayload {
-
-    fun provides(service: Service?) = service?.isEnabled(services) == true
-
-    override val command: MessagePayload.Command = MessagePayload.Command.VERSION
-
-    override fun writer(): StreamableWriter = Writer(this)
-
-    private class Writer(
-        private val item: Version
-    ) : StreamableWriter {
-        override fun write(out: OutputStream) {
-            Encode.int32(item.version, out)
-            Encode.int64(item.services, out)
-            Encode.int64(item.timestamp, out)
-            item.addrRecv.writer(true).write(out)
-            item.addrFrom.writer(true).write(out)
-            Encode.int64(item.nonce, out)
-            Encode.varString(item.userAgent, out)
-            Encode.varIntList(item.streams, out)
-        }
-
-        override fun write(buffer: ByteBuffer) {
-            Encode.int32(item.version, buffer)
-            Encode.int64(item.services, buffer)
-            Encode.int64(item.timestamp, buffer)
-            item.addrRecv.writer(true).write(buffer)
-            item.addrFrom.writer(true).write(buffer)
-            Encode.int64(item.nonce, buffer)
-            Encode.varString(item.userAgent, buffer)
-            Encode.varIntList(item.streams, buffer)
-        }
-    }
-
-    class Builder {
-        private var version: Int = 0
-        private var services: Long = 0
-        private var timestamp: Long = 0
-        private var addrRecv: NetworkAddress? = null
-        private var addrFrom: NetworkAddress? = null
-        private var nonce: Long = 0
-        private var userAgent: String? = null
-        private var streamNumbers: LongArray? = null
-
-        fun defaults(clientNonce: Long): Builder {
-            version = BitmessageContext.CURRENT_VERSION
-            services = Service.getServiceFlag(Service.NODE_NETWORK)
-            timestamp = UnixTime.now
-            userAgent = "/Jabit:0.0.1/"
-            streamNumbers = longArrayOf(1)
-            nonce = clientNonce
-            return this
-        }
-
-        fun version(version: Int): Builder {
-            this.version = version
-            return this
-        }
-
-        fun services(vararg services: Service): Builder {
-            this.services = Service.getServiceFlag(*services)
-            return this
-        }
-
-        fun services(services: Long): Builder {
-            this.services = services
-            return this
-        }
-
-        fun timestamp(timestamp: Long): Builder {
-            this.timestamp = timestamp
-            return this
-        }
-
-        fun addrRecv(addrRecv: NetworkAddress): Builder {
-            this.addrRecv = addrRecv
-            return this
-        }
-
-        fun addrFrom(addrFrom: NetworkAddress): Builder {
-            this.addrFrom = addrFrom
-            return this
-        }
-
-        fun nonce(nonce: Long): Builder {
-            this.nonce = nonce
-            return this
-        }
-
-        fun userAgent(userAgent: String): Builder {
-            this.userAgent = userAgent
-            return this
-        }
-
-        fun streams(vararg streamNumbers: Long): Builder {
-            this.streamNumbers = streamNumbers
-            return this
-        }
-
-        fun build(): Version {
-            val addrRecv = this.addrRecv
-            val addrFrom = this.addrFrom
-            if (addrRecv == null || addrFrom == null) {
-                throw IllegalStateException("Receiving and sending address must be set")
-            }
-
-            return Version(
-                version = version,
-                services = services,
-                timestamp = timestamp,
-                addrRecv = addrRecv, addrFrom = addrFrom,
-                nonce = nonce,
-                userAgent = userAgent ?: "/Jabit:0.0.1/",
-                streams = streamNumbers ?: longArrayOf(1)
-            )
-        }
-    }
-
-    enum class Service constructor(internal var flag: Long) {
-        // TODO: NODE_SSL(2);
-        NODE_NETWORK(1);
-
-        fun isEnabled(flag: Long) = (flag and this.flag) != 0L
-
-        companion object {
-            fun getServiceFlag(vararg services: Service): Long {
-                var flag: Long = 0
-                for (service in services) {
-                    flag = flag or service.flag
-                }
-                return flag
-            }
-        }
-    }
-}

core/src/main/kotlin/ch/dissem/bitmessage/entity/payload/Broadcast.kt

@@ -1,83 +0,0 @@
-/*
- * Copyright 2017 Christian Basler
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package ch.dissem.bitmessage.entity.payload
-
-import ch.dissem.bitmessage.entity.BitmessageAddress
-import ch.dissem.bitmessage.entity.Encrypted
-import ch.dissem.bitmessage.entity.Plaintext
-import ch.dissem.bitmessage.entity.Plaintext.Type.BROADCAST
-import ch.dissem.bitmessage.entity.PlaintextHolder
-import ch.dissem.bitmessage.exception.DecryptionFailedException
-import ch.dissem.bitmessage.utils.Singleton.cryptography
-import java.util.*
-
-/**
- * Users who are subscribed to the sending address will see the message appear in their inbox.
- * Broadcasts are version 4 or 5.
- */
-abstract class Broadcast protected constructor(
-    version: Long,
-    override val stream: Long,
-    protected var encrypted: CryptoBox?,
-    override var plaintext: Plaintext?
-) : ObjectPayload(version), Encrypted, PlaintextHolder {
-
-    override val isSigned: Boolean = true
-
-    override var signature: ByteArray?
-        get() = plaintext?.signature
-        set(signature) {
-            plaintext?.signature = signature ?: throw IllegalStateException("no plaintext data available")
-        }
-
-    override fun encrypt(publicKey: ByteArray) {
-        this.encrypted = CryptoBox(plaintext ?: throw IllegalStateException("no plaintext data available"), publicKey)
-    }
-
-    fun encrypt() {
-        encrypt(cryptography().createPublicKey(plaintext?.from?.publicDecryptionKey ?: return))
-    }
-
-    @Throws(DecryptionFailedException::class)
-    override fun decrypt(privateKey: ByteArray) {
-        plaintext = Plaintext.read(BROADCAST, encrypted?.decrypt(privateKey) ?: return)
-    }
-
-    @Throws(DecryptionFailedException::class)
-    fun decrypt(address: BitmessageAddress) {
-        decrypt(address.publicDecryptionKey)
-    }
-
-    override val isDecrypted: Boolean
-        get() = plaintext != null
-
-    override fun equals(other: Any?): Boolean {
-        if (this === other) return true
-        if (other !is Broadcast) return false
-        return stream == other.stream && (encrypted == other.encrypted || plaintext == other.plaintext)
-    }
-
-    override fun hashCode(): Int {
-        return Objects.hash(stream)
-    }
-
-    companion object {
-        fun getVersion(address: BitmessageAddress): Long {
-            return if (address.version < 4) 4L else 5L
-        }
-    }
-}