Moved POW to its own port so it will be easily possible to create other (faster) implementations

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

@@ -0,0 +1,34 @@
+/*
+ * 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 nonceTrialsPerByte
+     * @param extraBytes
+     * @return 8 bytes nonce
+     */
+    byte[] calculateNonce(byte[] initialHash, byte[] target, long nonceTrialsPerByte, long extraBytes);
+}

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

@@ -0,0 +1,46 @@
+/*
+ * 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.utils.Bytes;
+
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+
+import static ch.dissem.bitmessage.utils.Bytes.inc;
+
+/**
+ * Created by chris on 14.04.15.
+ */
+public class SimplePOWEngine implements ProofOfWorkEngine {
+    @Override
+    public byte[] calculateNonce(byte[] initialHash, byte[] target, long nonceTrialsPerByte, long extraBytes) {
+        byte[] nonce = new byte[8];
+        MessageDigest mda;
+        try {
+            mda = MessageDigest.getInstance("SHA-512");
+        } catch (NoSuchAlgorithmException e) {
+            throw new RuntimeException(e);
+        }
+        do {
+            inc(nonce);
+            mda.update(nonce);
+            mda.update(initialHash);
+        } while (Bytes.lt(target, mda.digest(mda.digest()), 8));
+        return nonce;
+    }
+}

domain/src/main/java/ch/dissem/bitmessage/utils/Security.java

@@ -17,6 +17,7 @@
 package ch.dissem.bitmessage.utils;
 
 import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.ports.ProofOfWorkEngine;
 import org.bouncycastle.jce.provider.BouncyCastleProvider;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -25,11 +26,8 @@ import java.io.IOException;
 import java.math.BigInteger;
 import java.security.GeneralSecurityException;
 import java.security.MessageDigest;
-import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
 
-import static ch.dissem.bitmessage.utils.Bytes.inc;
-
 /**
  * Provides some methods to help with hashing and encryption.
  */
@@ -68,23 +66,12 @@ public class Security {
         return result;
     }
 
-    public static void doProofOfWork(ObjectMessage object, long nonceTrialsPerByte, long extraBytes) throws IOException {
+    public static void doProofOfWork(ObjectMessage object, ProofOfWorkEngine worker, long nonceTrialsPerByte, long extraBytes) throws IOException {
         byte[] initialHash = getInitialHash(object);
 
         byte[] target = getProofOfWorkTarget(object, nonceTrialsPerByte, extraBytes);
-        // also start with nonce = 0 where nonce is 8 bytes in length and can be hashed as if it is a string.
-        byte[] nonce = new byte[8];
-        MessageDigest mda;
-        try {
-            mda = MessageDigest.getInstance("SHA-512");
-        } catch (NoSuchAlgorithmException e) {
-            throw new RuntimeException(e);
-        }
-        do {
-            inc(nonce);
-            mda.update(nonce);
-            mda.update(initialHash);
-        } while (Bytes.lt(target, mda.digest(mda.digest()), 8));
+
+        byte[] nonce = worker.calculateNonce(initialHash, target, nonceTrialsPerByte, extraBytes);
         object.setNonce(nonce);
     }
 

domain/src/test/java/ch/dissem/bitmessage/utils/SecurityTest.java

@@ -18,10 +18,12 @@ package ch.dissem.bitmessage.utils;
 
 import ch.dissem.bitmessage.entity.ObjectMessage;
 import ch.dissem.bitmessage.entity.payload.GenericPayload;
+import ch.dissem.bitmessage.ports.SimplePOWEngine;
 import org.junit.Test;
 
 import javax.xml.bind.DatatypeConverter;
 import java.io.IOException;
+import java.security.KeyPairGenerator;
 import java.util.Calendar;
 import java.util.GregorianCalendar;
 
@@ -84,7 +86,14 @@ public class SecurityTest {
                 .expiresTime(expires.getTimeInMillis() / 1000)
                 .payload(new GenericPayload(1, new byte[0]))
                 .build();
-        Security.doProofOfWork(objectMessage, 1000, 1000);
-        Security.checkProofOfWork(objectMessage, 1000, 1000);
+        Security.doProofOfWork(objectMessage, new SimplePOWEngine(), 10, 10);
+        Security.checkProofOfWork(objectMessage, 10, 10);
+    }
+
+    @Test
+    public void testECIES() throws Exception {
+        KeyPairGenerator kpg = KeyPairGenerator.getInstance("ECIES", "BC");
+//        kpg.initialize();
+        kpg.generateKeyPair();
     }
 }