Server POW (work in progress)

app/src/main/java/ch/dissem/apps/abit/adapter/AndroidSecurity.java

@@ -0,0 +1,84 @@
+package ch.dissem.apps.abit.adapter;
+
+import android.content.Context;
+import android.content.SharedPreferences;
+import android.preference.PreferenceManager;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+
+import ch.dissem.apps.abit.util.PRNGFixes;
+import ch.dissem.bitmessage.entity.BitmessageAddress;
+import ch.dissem.bitmessage.entity.ObjectMessage;
+import ch.dissem.bitmessage.entity.Plaintext;
+import ch.dissem.bitmessage.entity.PlaintextHolder;
+import ch.dissem.bitmessage.entity.payload.Broadcast;
+import ch.dissem.bitmessage.entity.valueobject.Label;
+import ch.dissem.bitmessage.factory.Factory;
+import ch.dissem.bitmessage.ports.ProofOfWorkEngine;
+import ch.dissem.bitmessage.security.sc.SpongySecurity;
+import ch.dissem.bitmessage.utils.UnixTime;
+
+import static ch.dissem.apps.abit.util.Constants.PREFERENCE_SERVER_POW;
+import static ch.dissem.bitmessage.entity.Plaintext.Status.SENT;
+import static ch.dissem.bitmessage.entity.Plaintext.Type.BROADCAST;
+import static ch.dissem.bitmessage.utils.UnixTime.DAY;
+
+/**
+ * @author Christian Basler
+ */
+public class AndroidSecurity extends SpongySecurity {
+    private final SharedPreferences preferences;
+
+    public AndroidSecurity(Context ctx) {
+        PRNGFixes.apply();
+        preferences = PreferenceManager.getDefaultSharedPreferences(ctx);
+    }
+
+    @Override
+    public void doProofOfWork(ObjectMessage object, long nonceTrialsPerByte, long extraBytes, ProofOfWorkEngine.Callback callback) {
+        if (preferences.getBoolean(PREFERENCE_SERVER_POW, false)) {
+            object.setNonce(new byte[8]);
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+            try {
+                object.write(out);
+                sendAsBroadcast(getContext().getAddressRepo().getIdentities().get(0), out.toByteArray());
+                if (object.getPayload() instanceof PlaintextHolder) {
+                    Plaintext plaintext = ((PlaintextHolder) object.getPayload()).getPlaintext();
+                    plaintext.setInventoryVector(object.getInventoryVector());
+                    plaintext.setStatus(SENT);
+                    plaintext.removeLabel(Label.Type.OUTBOX);
+                    plaintext.addLabels(getContext().getMessageRepository().getLabels(Label.Type.SENT));
+                    getContext().getMessageRepository().save(plaintext);
+
+                }
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        } else {
+            super.doProofOfWork(object, nonceTrialsPerByte, extraBytes, callback);
+        }
+    }
+
+    private void sendAsBroadcast(BitmessageAddress identity, byte[] data) throws IOException {
+        Plaintext msg = new Plaintext.Builder(BROADCAST)
+                .from(identity)
+                .message(data)
+                .build();
+        Broadcast payload = Factory.getBroadcast(identity, msg);
+        long expires = UnixTime.now(+2 * DAY);
+        final ObjectMessage object = new ObjectMessage.Builder()
+                .stream(identity.getStream())
+                .expiresTime(expires)
+                .payload(payload)
+                .build();
+        object.sign(identity.getPrivateKey());
+        payload.encrypt();
+        object.setNonce(new byte[8]);
+
+        getContext().getInventory().storeObject(object);
+        getContext().getNetworkHandler().offer(object.getInventoryVector());
+        // TODO: offer to the trusted node only?
+        // at least make sure it is offered to the trusted node!
+    }
+}