Builders for incoming and outgoing headers and batches. The protocol and serial components can now be used to serialise, sign, deserialise and verify real bundles (except for message parsing).

components/net/sf/briar/db/JdbcDatabase.java

@@ -467,7 +467,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setBytes(4, m.getAuthor().getBytes());
 			ps.setLong(5, m.getTimestamp());
 			ps.setInt(6, m.getSize());
-			ps.setBlob(7, new ByteArrayInputStream(m.getBody()));
+			ps.setBlob(7, new ByteArrayInputStream(m.getBytes()));
 			ps.setInt(8, 0);
 			int rowsAffected = ps.executeUpdate();
 			assert rowsAffected == 1;

components/net/sf/briar/db/ReadWriteLockDatabaseComponent.java

@@ -1,6 +1,7 @@
 package net.sf.briar.db;
 
 import java.io.IOException;
+import java.security.GeneralSecurityException;
 import java.security.SignatureException;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -18,8 +19,9 @@ import net.sf.briar.api.protocol.AuthorId;
 import net.sf.briar.api.protocol.Batch;
 import net.sf.briar.api.protocol.BatchBuilder;
 import net.sf.briar.api.protocol.BatchId;
-import net.sf.briar.api.protocol.Bundle;
-import net.sf.briar.api.protocol.BundleBuilder;
+import net.sf.briar.api.protocol.BundleId;
+import net.sf.briar.api.protocol.BundleReader;
+import net.sf.briar.api.protocol.BundleWriter;
 import net.sf.briar.api.protocol.GroupId;
 import net.sf.briar.api.protocol.Header;
 import net.sf.briar.api.protocol.HeaderBuilder;
@@ -190,8 +192,8 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		}
 	}
 
-	public Bundle generateBundle(ContactId c, BundleBuilder b)
-	throws DbException, IOException, SignatureException {
+	public void generateBundle(ContactId c, BundleWriter b) throws DbException,
+	IOException, GeneralSecurityException {
 		if(LOG.isLoggable(Level.FINE)) LOG.fine("Generating bundle for " + c);
 		HeaderBuilder h;
 		// Add acks
@@ -280,15 +282,13 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 			// more messages trickling in but we can't wait forever
 			if(size * 2 < Batch.MAX_SIZE) break;
 		}
-		Bundle bundle = b.build();
-		if(LOG.isLoggable(Level.FINE))
-			LOG.fine("Bundle generated, " + bundle.getSize() + " bytes");
+		b.close();
+		if(LOG.isLoggable(Level.FINE)) LOG.fine("Bundle generated");
 		System.gc();
-		return bundle;
 	}
 
 	private Batch fillBatch(ContactId c, long capacity) throws DbException,
-	SignatureException {
+	IOException, GeneralSecurityException {
 		contactLock.readLock().lock();
 		try {
 			if(!containsContact(c)) throw new NoSuchContactException();
@@ -441,8 +441,8 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		}
 	}
 
-	public void receiveBundle(ContactId c, Bundle b) throws DbException,
-	IOException, SignatureException {
+	public void receiveBundle(ContactId c, BundleReader b) throws DbException,
+	IOException, GeneralSecurityException {
 		if(LOG.isLoggable(Level.FINE))
 			LOG.fine("Received bundle from " + c + ", "
 					+ b.getSize() + " bytes");
@@ -529,52 +529,64 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		}
 		// Store the messages
 		int batches = 0;
-		for(Batch batch = b.getNextBatch(); batch != null; batch = b.getNextBatch()) {
+		Batch batch = null;
+		while((batch = b.getNextBatch()) != null) {
+			storeBatch(c, batch);
 			batches++;
-			waitForPermissionToWrite();
-			contactLock.readLock().lock();
-			try {
-				if(!containsContact(c)) throw new NoSuchContactException();
-				messageLock.writeLock().lock();
-				try {
-					messageStatusLock.writeLock().lock();
-					try {
-						subscriptionLock.readLock().lock();
-						try {
-							Txn txn = db.startTransaction();
-							try {
-								int received = 0, stored = 0;
-								for(Message m : batch.getMessages()) {
-									received++;
-									GroupId g = m.getGroup();
-									if(db.containsSubscription(txn, g)) {
-										if(storeMessage(txn, m, c)) stored++;
-									}
-								}
-								if(LOG.isLoggable(Level.FINE))
-									LOG.fine("Received " + received
-											+ " messages, stored " + stored);
-								db.addBatchToAck(txn, c, batch.getId());
-								db.commitTransaction(txn);
-							} catch(DbException e) {
-								db.abortTransaction(txn);
-								throw e;
-							}
-						} finally {
-							subscriptionLock.readLock().unlock();
-						}
-					} finally {
-						messageStatusLock.writeLock().unlock();
-					}
-				} finally {
-					messageLock.writeLock().unlock();
-				}
-			} finally {
-				contactLock.readLock().unlock();
-			}
 		}
 		if(LOG.isLoggable(Level.FINE))
 			LOG.fine("Received " + batches + " batches");
+		b.close();
+		retransmitLostBatches(c, h.getId());
+		System.gc();
+	}
+
+	private void storeBatch(ContactId c, Batch b) throws DbException {
+		waitForPermissionToWrite();
+		contactLock.readLock().lock();
+		try {
+			if(!containsContact(c)) throw new NoSuchContactException();
+			messageLock.writeLock().lock();
+			try {
+				messageStatusLock.writeLock().lock();
+				try {
+					subscriptionLock.readLock().lock();
+					try {
+						Txn txn = db.startTransaction();
+						try {
+							int received = 0, stored = 0;
+							for(Message m : b.getMessages()) {
+								received++;
+								GroupId g = m.getGroup();
+								if(db.containsSubscription(txn, g)) {
+									if(storeMessage(txn, m, c)) stored++;
+								}
+							}
+							if(LOG.isLoggable(Level.FINE))
+								LOG.fine("Received " + received
+										+ " messages, stored " + stored);
+							db.addBatchToAck(txn, c, b.getId());
+							db.commitTransaction(txn);
+						} catch(DbException e) {
+							db.abortTransaction(txn);
+							throw e;
+						}
+					} finally {
+						subscriptionLock.readLock().unlock();
+					}
+				} finally {
+					messageStatusLock.writeLock().unlock();
+				}
+			} finally {
+				messageLock.writeLock().unlock();
+			}
+		} finally {
+			contactLock.readLock().unlock();
+		}
+	}
+
+	private void retransmitLostBatches(ContactId c, BundleId b)
+	throws DbException {
 		// Find any lost batches that need to be retransmitted
 		Set<BatchId> lost;
 		contactLock.readLock().lock();
@@ -586,7 +598,7 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				try {
 					Txn txn = db.startTransaction();
 					try {
-						lost = db.addReceivedBundle(txn, c, h.getId());
+						lost = db.addReceivedBundle(txn, c, b);
 						db.commitTransaction(txn);
 					} catch(DbException e) {
 						db.abortTransaction(txn);
@@ -629,7 +641,6 @@ class ReadWriteLockDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				contactLock.readLock().unlock();
 			}
 		}
-		System.gc();
 	}
 
 	public void removeContact(ContactId c) throws DbException {

components/net/sf/briar/db/SynchronizedDatabaseComponent.java

@@ -1,6 +1,7 @@
 package net.sf.briar.db;
 
 import java.io.IOException;
+import java.security.GeneralSecurityException;
 import java.security.SignatureException;
 import java.util.HashSet;
 import java.util.Iterator;
@@ -17,8 +18,9 @@ import net.sf.briar.api.protocol.AuthorId;
 import net.sf.briar.api.protocol.Batch;
 import net.sf.briar.api.protocol.BatchBuilder;
 import net.sf.briar.api.protocol.BatchId;
-import net.sf.briar.api.protocol.Bundle;
-import net.sf.briar.api.protocol.BundleBuilder;
+import net.sf.briar.api.protocol.BundleId;
+import net.sf.briar.api.protocol.BundleReader;
+import net.sf.briar.api.protocol.BundleWriter;
 import net.sf.briar.api.protocol.GroupId;
 import net.sf.briar.api.protocol.Header;
 import net.sf.briar.api.protocol.HeaderBuilder;
@@ -143,8 +145,8 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		}
 	}
 
-	public Bundle generateBundle(ContactId c, BundleBuilder b)
-	throws DbException, IOException, SignatureException {
+	public void generateBundle(ContactId c, BundleWriter b) throws DbException,
+	IOException, GeneralSecurityException {
 		if(LOG.isLoggable(Level.FINE)) LOG.fine("Generating bundle for " + c);
 		HeaderBuilder h;
 		// Add acks
@@ -215,15 +217,13 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 			// more messages trickling in but we can't wait forever
 			if(size * 2 < Batch.MAX_SIZE) break;
 		}
-		Bundle bundle = b.build();
-		if(LOG.isLoggable(Level.FINE))
-			LOG.fine("Bundle generated, " + bundle.getSize() + " bytes");
+		b.close();
+		if(LOG.isLoggable(Level.FINE)) LOG.fine("Bundle generated");
 		System.gc();
-		return bundle;
 	}
 
 	private Batch fillBatch(ContactId c, long capacity) throws DbException,
-	SignatureException {
+	IOException, GeneralSecurityException {
 		synchronized(contactLock) {
 			if(!containsContact(c)) throw new NoSuchContactException();
 			synchronized(messageLock) {
@@ -335,8 +335,8 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		}
 	}
 
-	public void receiveBundle(ContactId c, Bundle b) throws DbException,
-	IOException, SignatureException {
+	public void receiveBundle(ContactId c, BundleReader b) throws DbException,
+	IOException, GeneralSecurityException {
 		if(LOG.isLoggable(Level.FINE))
 			LOG.fine("Received bundle from " + c + ", "
 					+ b.getSize() + " bytes");
@@ -402,40 +402,52 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 		}
 		// Store the messages
 		int batches = 0;
-		for(Batch batch = b.getNextBatch(); batch != null; batch = b.getNextBatch()) {
+		Batch batch = null;
+		while((batch = b.getNextBatch()) != null) {
+			storeBatch(c, batch);
 			batches++;
-			waitForPermissionToWrite();
-			synchronized(contactLock) {
-				if(!containsContact(c)) throw new NoSuchContactException();
-				synchronized(messageLock) {
-					synchronized(messageStatusLock) {
-						synchronized(subscriptionLock) {
-							Txn txn = db.startTransaction();
-							try {
-								int received = 0, stored = 0;
-								for(Message m : batch.getMessages()) {
-									received++;
-									GroupId g = m.getGroup();
-									if(db.containsSubscription(txn, g)) {
-										if(storeMessage(txn, m, c)) stored++;
-									}
+		}
+		if(LOG.isLoggable(Level.FINE))
+			LOG.fine("Received " + batches + " batches");
+		b.close();
+		retransmitLostBatches(c, h.getId());
+		System.gc();
+	}
+
+	private void storeBatch(ContactId c, Batch b) throws DbException {
+		waitForPermissionToWrite();
+		synchronized(contactLock) {
+			if(!containsContact(c)) throw new NoSuchContactException();
+			synchronized(messageLock) {
+				synchronized(messageStatusLock) {
+					synchronized(subscriptionLock) {
+						Txn txn = db.startTransaction();
+						try {
+							int received = 0, stored = 0;
+							for(Message m : b.getMessages()) {
+								received++;
+								GroupId g = m.getGroup();
+								if(db.containsSubscription(txn, g)) {
+									if(storeMessage(txn, m, c)) stored++;
 								}
-								if(LOG.isLoggable(Level.FINE))
-									LOG.fine("Received " + received
-											+ " messages, stored " + stored);
-								db.addBatchToAck(txn, c, batch.getId());
-								db.commitTransaction(txn);
-							} catch(DbException e) {
-								db.abortTransaction(txn);
-								throw e;
 							}
+							if(LOG.isLoggable(Level.FINE))
+								LOG.fine("Received " + received
+										+ " messages, stored " + stored);
+							db.addBatchToAck(txn, c, b.getId());
+							db.commitTransaction(txn);
+						} catch(DbException e) {
+							db.abortTransaction(txn);
+							throw e;
 						}
 					}
 				}
 			}
 		}
-		if(LOG.isLoggable(Level.FINE))
-			LOG.fine("Received " + batches + " batches");
+	}
+
+	private void retransmitLostBatches(ContactId c, BundleId b)
+	throws DbException {
 		// Find any lost batches that need to be retransmitted
 		Set<BatchId> lost;
 		synchronized(contactLock) {
@@ -444,7 +456,7 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				synchronized(messageStatusLock) {
 					Txn txn = db.startTransaction();
 					try {
-						lost = db.addReceivedBundle(txn, c, h.getId());
+						lost = db.addReceivedBundle(txn, c, b);
 						db.commitTransaction(txn);
 					} catch(DbException e) {
 						db.abortTransaction(txn);
@@ -472,7 +484,6 @@ class SynchronizedDatabaseComponent<Txn> extends DatabaseComponentImpl<Txn> {
 				}
 			}
 		}
-		System.gc();
 	}
 
 	public void removeContact(ContactId c) throws DbException {

components/net/sf/briar/protocol/BatchBuilderImpl.java

@@ -0,0 +1,44 @@
+package net.sf.briar.protocol;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.security.KeyPair;
+import java.security.MessageDigest;
+import java.security.Signature;
+import java.util.ArrayList;
+import java.util.List;
+
+import net.sf.briar.api.protocol.BatchBuilder;
+import net.sf.briar.api.protocol.Message;
+import net.sf.briar.api.serial.Writer;
+import net.sf.briar.api.serial.WriterFactory;
+
+abstract class BatchBuilderImpl implements BatchBuilder {
+
+	protected final List<Message> messages = new ArrayList<Message>();
+	protected final KeyPair keyPair;
+	protected final Signature signature;
+	protected final MessageDigest messageDigest;
+
+	private final WriterFactory writerFactory;
+
+	protected BatchBuilderImpl(KeyPair keyPair, Signature signature,
+			MessageDigest messageDigest, WriterFactory writerFactory) {
+		this.keyPair = keyPair;
+		this.signature = signature;
+		this.messageDigest = messageDigest;
+		this.writerFactory = writerFactory;
+	}
+
+	public void addMessage(Message m) {
+		messages.add(m);
+	}
+
+	protected byte[] getSignableRepresentation() throws IOException {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		Writer w = writerFactory.createWriter(out);
+		w.writeList(messages);
+		w.close();
+		return out.toByteArray();
+	}
+}

components/net/sf/briar/protocol/BundleReaderImpl.java

@@ -1,7 +1,7 @@
 package net.sf.briar.protocol;
 
 import java.io.IOException;
-import java.security.SignatureException;
+import java.security.GeneralSecurityException;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -10,7 +10,7 @@ import java.util.Set;
 import net.sf.briar.api.protocol.Batch;
 import net.sf.briar.api.protocol.BatchBuilder;
 import net.sf.briar.api.protocol.BatchId;
-import net.sf.briar.api.protocol.Bundle;
+import net.sf.briar.api.protocol.BundleReader;
 import net.sf.briar.api.protocol.GroupId;
 import net.sf.briar.api.protocol.Header;
 import net.sf.briar.api.protocol.HeaderBuilder;
@@ -24,26 +24,32 @@ import net.sf.briar.api.serial.Reader;
 import com.google.inject.Provider;
 
 /** A bundle that deserialises its contents on demand using a reader. */
-abstract class BundleReader implements Bundle {
+class BundleReaderImpl implements BundleReader {
 
 	private static enum State { START, FIRST_BATCH, MORE_BATCHES, END };
 
 	private final Reader r;
+	private final long size;
 	private final MessageParser messageParser;
 	private final Provider<HeaderBuilder> headerBuilderProvider;
 	private final Provider<BatchBuilder> batchBuilderProvider;
 	private State state = State.START;
 
-	BundleReader(Reader r, MessageParser messageParser,
+	BundleReaderImpl(Reader r, long size, MessageParser messageParser,
 			Provider<HeaderBuilder> headerBuilderProvider,
 			Provider<BatchBuilder> batchBuilderProvider) {
 		this.r = r;
+		this.size = size;
 		this.messageParser = messageParser;
 		this.headerBuilderProvider = headerBuilderProvider;
 		this.batchBuilderProvider = batchBuilderProvider;
 	}
 
-	public Header getHeader() throws IOException, SignatureException {
+	public long getSize() {
+		return size;
+	}
+
+	public Header getHeader() throws IOException, GeneralSecurityException {
 		if(state != State.START) throw new IllegalStateException();
 		r.setReadLimit(Header.MAX_SIZE);
 		Set<BatchId> acks = new HashSet<BatchId>();
@@ -69,7 +75,7 @@ abstract class BundleReader implements Bundle {
 		return h.build();
 	}
 
-	public Batch getNextBatch() throws IOException, SignatureException {
+	public Batch getNextBatch() throws IOException, GeneralSecurityException {
 		if(state == State.FIRST_BATCH) {
 			r.readListStart();
 			state = State.MORE_BATCHES;
@@ -91,4 +97,8 @@ abstract class BundleReader implements Bundle {
 		b.setSignature(sig);
 		return b.build();
 	}
+
+	public void close() throws IOException {
+		r.close();
+	}
 }

components/net/sf/briar/protocol/BundleWriterImpl.java

@@ -4,14 +4,14 @@ import java.io.IOException;
 
 import net.sf.briar.api.protocol.Batch;
 import net.sf.briar.api.protocol.BatchId;
-import net.sf.briar.api.protocol.BundleBuilder;
+import net.sf.briar.api.protocol.BundleWriter;
 import net.sf.briar.api.protocol.GroupId;
 import net.sf.briar.api.protocol.Header;
 import net.sf.briar.api.protocol.Message;
 import net.sf.briar.api.serial.Writer;
 
 /** A bundle builder that serialises its contents using a writer. */
-abstract class BundleWriter implements BundleBuilder {
+class BundleWriterImpl implements BundleWriter {
 
 	private static enum State { START, FIRST_BATCH, MORE_BATCHES, END };
 
@@ -19,7 +19,7 @@ abstract class BundleWriter implements BundleBuilder {
 	private final long capacity;
 	private State state = State.START;
 
-	BundleWriter(Writer w, long capacity) {
+	BundleWriterImpl(Writer w, long capacity) {
 		this.w = w;
 		this.capacity = capacity;
 	}
@@ -48,12 +48,12 @@ abstract class BundleWriter implements BundleBuilder {
 		}
 		if(state != State.MORE_BATCHES) throw new IllegalStateException();
 		w.writeListStart();
-		for(Message m : b.getMessages()) w.writeRaw(m.getBody());
+		for(Message m : b.getMessages()) w.writeRaw(m.getBytes());
 		w.writeListEnd();
 		w.writeRaw(b.getSignature());
 	}
 
-	void close() throws IOException {
+	public void close() throws IOException {
 		if(state == State.FIRST_BATCH) {
 			w.writeListStart();
 			state = State.MORE_BATCHES;

components/net/sf/briar/protocol/FileBundle.java

@@ -1,30 +0,0 @@
-package net.sf.briar.protocol;
-
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.IOException;
-
-import net.sf.briar.api.protocol.BatchBuilder;
-import net.sf.briar.api.protocol.HeaderBuilder;
-import net.sf.briar.api.protocol.MessageParser;
-import net.sf.briar.api.serial.ReaderFactory;
-
-import com.google.inject.Provider;
-
-class FileBundle extends BundleReader {
-
-	private final File file;
-
-	FileBundle(File file, ReaderFactory readerFactory,
-			MessageParser messageParser,
-			Provider<HeaderBuilder> headerBuilderProvider,
-			Provider<BatchBuilder> batchBuilderProvider) throws IOException {
-		super(readerFactory.createReader(new FileInputStream(file)),
-				messageParser, headerBuilderProvider, batchBuilderProvider);
-		this.file = file;
-	}
-
-	public long getSize() throws IOException {
-		return file.length();
-	}
-}

components/net/sf/briar/protocol/FileBundleBuilder.java

@@ -1,41 +0,0 @@
-package net.sf.briar.protocol;
-
-import java.io.File;
-import java.io.FileOutputStream;
-import java.io.IOException;
-
-import net.sf.briar.api.protocol.BatchBuilder;
-import net.sf.briar.api.protocol.Bundle;
-import net.sf.briar.api.protocol.HeaderBuilder;
-import net.sf.briar.api.protocol.MessageParser;
-import net.sf.briar.api.serial.ReaderFactory;
-import net.sf.briar.api.serial.WriterFactory;
-
-import com.google.inject.Provider;
-
-public class FileBundleBuilder extends BundleWriter {
-
-	private final File file;
-	private final ReaderFactory readerFactory;
-	private final MessageParser messageParser;
-	private final Provider<HeaderBuilder> headerBuilderProvider;
-	private final Provider<BatchBuilder> batchBuilderProvider;
-
-	FileBundleBuilder(File file, long capacity, WriterFactory writerFactory,
-			ReaderFactory readerFactory, MessageParser messageParser,
-			Provider<HeaderBuilder> headerBuilderProvider,
-			Provider<BatchBuilder> batchBuilderProvider) throws IOException {
-		super(writerFactory.createWriter(new FileOutputStream(file)), capacity);
-		this.file = file;
-		this.readerFactory = readerFactory;
-		this.messageParser = messageParser;
-		this.headerBuilderProvider = headerBuilderProvider;
-		this.batchBuilderProvider = batchBuilderProvider;
-	}
-
-	public Bundle build() throws IOException {
-		super.close();
-		return new FileBundle(file, readerFactory, messageParser,
-				headerBuilderProvider, batchBuilderProvider);
-	}
-}

components/net/sf/briar/protocol/HeaderBuilderImpl.java

@@ -0,0 +1,63 @@
+package net.sf.briar.protocol;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.security.KeyPair;
+import java.security.MessageDigest;
+import java.security.Signature;
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import net.sf.briar.api.protocol.BatchId;
+import net.sf.briar.api.protocol.GroupId;
+import net.sf.briar.api.protocol.HeaderBuilder;
+import net.sf.briar.api.serial.Writer;
+import net.sf.briar.api.serial.WriterFactory;
+
+abstract class HeaderBuilderImpl implements HeaderBuilder {
+
+	protected final List<BatchId> acks = new ArrayList<BatchId>();
+	protected final List<GroupId> subs = new ArrayList<GroupId>();
+	protected final Map<String, String> transports =
+		new LinkedHashMap<String, String>();
+
+	protected final KeyPair keyPair;
+	protected final Signature signature;
+	protected final MessageDigest messageDigest;
+
+	private final WriterFactory writerFactory;
+
+	protected HeaderBuilderImpl(KeyPair keyPair, Signature signature,
+			MessageDigest messageDigest, WriterFactory writerFactory) {
+		this.keyPair = keyPair;
+		this.signature = signature;
+		this.messageDigest = messageDigest;
+		this.writerFactory = writerFactory;
+	}
+
+	public void addAcks(Iterable<BatchId> acks) {
+		for(BatchId ack : acks) this.acks.add(ack);
+	}
+
+	public void addSubscriptions(Iterable<GroupId> subs) {
+		for(GroupId sub : subs) this.subs.add(sub);
+	}
+
+	public void addTransports(Map<String, String> transports) {
+		for(String key : transports.keySet()) {
+			this.transports.put(key, transports.get(key));
+		}
+	}
+
+	protected byte[] getSignableRepresentation() throws IOException {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		Writer w = writerFactory.createWriter(out);
+		w.writeList(acks);
+		w.writeList(subs);
+		w.writeMap(transports);
+		w.close();
+		return out.toByteArray();
+	}
+}

components/net/sf/briar/protocol/IncomingBatchBuilder.java

@@ -0,0 +1,40 @@
+package net.sf.briar.protocol;
+
+import java.io.IOException;
+import java.security.InvalidKeyException;
+import java.security.KeyPair;
+import java.security.MessageDigest;
+import java.security.Signature;
+import java.security.SignatureException;
+
+import net.sf.briar.api.protocol.Batch;
+import net.sf.briar.api.protocol.BatchId;
+import net.sf.briar.api.serial.WriterFactory;
+
+public class IncomingBatchBuilder extends BatchBuilderImpl {
+
+	IncomingBatchBuilder(KeyPair keyPair, Signature signature,
+			MessageDigest messageDigest, WriterFactory writerFactory) {
+		super(keyPair, signature, messageDigest, writerFactory);
+	}
+
+	private byte[] sig = null;
+
+	public void setSignature(byte[] sig) {
+		this.sig = sig;
+	}
+
+	public Batch build() throws IOException, SignatureException,
+	InvalidKeyException {
+		if(sig == null) throw new IllegalStateException();
+		byte[] raw = getSignableRepresentation();
+		signature.initVerify(keyPair.getPublic());
+		signature.update(raw);
+		signature.verify(sig);
+		messageDigest.reset();
+		messageDigest.update(raw);
+		messageDigest.update(sig);
+		byte[] hash = messageDigest.digest();
+		return new BatchImpl(new BatchId(hash), raw.length, messages, sig);
+	}
+}

components/net/sf/briar/protocol/IncomingHeaderBuilder.java

@@ -0,0 +1,47 @@
+package net.sf.briar.protocol;
+
+import java.io.IOException;
+import java.security.InvalidKeyException;
+import java.security.KeyPair;
+import java.security.MessageDigest;
+import java.security.Signature;
+import java.security.SignatureException;
+import java.util.HashSet;
+import java.util.Set;
+
+import net.sf.briar.api.protocol.BatchId;
+import net.sf.briar.api.protocol.BundleId;
+import net.sf.briar.api.protocol.GroupId;
+import net.sf.briar.api.protocol.Header;
+import net.sf.briar.api.serial.WriterFactory;
+
+class IncomingHeaderBuilder extends HeaderBuilderImpl {
+
+	private byte[] sig = null;
+
+	IncomingHeaderBuilder(KeyPair keyPair, Signature signature,
+			MessageDigest messageDigest, WriterFactory writerFactory) {
+		super(keyPair, signature, messageDigest, writerFactory);
+	}
+
+	public void setSignature(byte[] sig) {
+		this.sig = sig;
+	}
+
+	public Header build() throws IOException, SignatureException,
+	InvalidKeyException {
+		if(sig == null) throw new IllegalStateException();
+		byte[] raw = getSignableRepresentation();
+		signature.initVerify(keyPair.getPublic());
+		signature.update(raw);
+		signature.verify(sig);
+		messageDigest.reset();
+		messageDigest.update(raw);
+		messageDigest.update(sig);
+		byte[] hash = messageDigest.digest();
+		Set<BatchId> ackSet = new HashSet<BatchId>(acks);
+		Set<GroupId> subSet = new HashSet<GroupId>(subs);
+		return new HeaderImpl(new BundleId(hash), raw.length, ackSet, subSet,
+				transports, sig);
+	}
+}

components/net/sf/briar/protocol/MessageImpl.java

@@ -48,7 +48,7 @@ public class MessageImpl implements Message {
 		return body.length;
 	}
 
-	public byte[] getBody() {
+	public byte[] getBytes() {
 		return body;
 	}
 

components/net/sf/briar/protocol/OutgoingBatchBuilder.java

@@ -0,0 +1,37 @@
+package net.sf.briar.protocol;
+
+import java.io.IOException;
+import java.security.InvalidKeyException;
+import java.security.KeyPair;
+import java.security.MessageDigest;
+import java.security.Signature;
+import java.security.SignatureException;
+
+import net.sf.briar.api.protocol.Batch;
+import net.sf.briar.api.protocol.BatchId;
+import net.sf.briar.api.serial.WriterFactory;
+
+public class OutgoingBatchBuilder extends BatchBuilderImpl {
+
+	OutgoingBatchBuilder(KeyPair keyPair, Signature signature,
+			MessageDigest messageDigest, WriterFactory writerFactory) {
+		super(keyPair, signature, messageDigest, writerFactory);
+	}
+
+	public void setSignature(byte[] sig) {
+		throw new UnsupportedOperationException();
+	}
+
+	public Batch build() throws IOException, SignatureException,
+	InvalidKeyException {
+		byte[] raw = getSignableRepresentation();
+		signature.initSign(keyPair.getPrivate());
+		signature.update(raw);
+		byte[] sig = signature.sign();
+		messageDigest.reset();
+		messageDigest.update(raw);
+		messageDigest.update(sig);
+		byte[] hash = messageDigest.digest();
+		return new BatchImpl(new BatchId(hash), raw.length, messages, sig);
+	}
+}

components/net/sf/briar/protocol/OutgoingHeaderBuilder.java

@@ -0,0 +1,44 @@
+package net.sf.briar.protocol;
+
+import java.io.IOException;
+import java.security.InvalidKeyException;
+import java.security.KeyPair;
+import java.security.MessageDigest;
+import java.security.Signature;
+import java.security.SignatureException;
+import java.util.HashSet;
+import java.util.Set;
+
+import net.sf.briar.api.protocol.BatchId;
+import net.sf.briar.api.protocol.BundleId;
+import net.sf.briar.api.protocol.GroupId;
+import net.sf.briar.api.protocol.Header;
+import net.sf.briar.api.serial.WriterFactory;
+
+public class OutgoingHeaderBuilder extends HeaderBuilderImpl {
+
+	OutgoingHeaderBuilder(KeyPair keyPair, Signature signature,
+			MessageDigest messageDigest, WriterFactory writerFactory) {
+		super(keyPair, signature, messageDigest, writerFactory);
+	}
+
+	public void setSignature(byte[] sig) {
+		throw new UnsupportedOperationException();
+	}
+
+	public Header build() throws IOException, SignatureException,
+	InvalidKeyException {
+		byte[] raw = getSignableRepresentation();
+		signature.initSign(keyPair.getPrivate());
+		signature.update(raw);
+		byte[] sig = signature.sign();
+		messageDigest.reset();
+		messageDigest.update(raw);
+		messageDigest.update(sig);
+		byte[] hash = messageDigest.digest();
+		Set<BatchId> ackSet = new HashSet<BatchId>(acks);
+		Set<GroupId> subSet = new HashSet<GroupId>(subs);
+		return new HeaderImpl(new BundleId(hash), raw.length, ackSet, subSet,
+				transports, sig);
+	}
+}

components/net/sf/briar/serial/ReaderFactoryImpl.java

@@ -5,7 +5,7 @@ import java.io.InputStream;
 import net.sf.briar.api.serial.Reader;
 import net.sf.briar.api.serial.ReaderFactory;
 
-class ReaderFactoryImpl implements ReaderFactory {
+public class ReaderFactoryImpl implements ReaderFactory {
 
 	public Reader createReader(InputStream in) {
 		return new ReaderImpl(in);

components/net/sf/briar/serial/ReaderImpl.java

@@ -53,6 +53,10 @@ class ReaderImpl implements Reader {
 		readLimit = 0L;
 	}
 
+	public void close() throws IOException {
+		in.close();
+	}
+
 	public boolean hasBoolean() throws IOException {
 		if(!started) readNext(true);
 		if(eof) return false;

components/net/sf/briar/serial/WriterFactoryImpl.java

@@ -5,7 +5,7 @@ import java.io.OutputStream;
 import net.sf.briar.api.serial.Writer;
 import net.sf.briar.api.serial.WriterFactory;
 
-class WriterFactoryImpl implements WriterFactory {
+public class WriterFactoryImpl implements WriterFactory {
 
 	public Writer createWriter(OutputStream out) {
 		return new WriterImpl(out);

components/net/sf/briar/serial/WriterImpl.java

@@ -18,6 +18,11 @@ class WriterImpl implements Writer {
 		this.out = out;
 	}
 
+	public void close() throws IOException {
+		out.flush();
+		out.close();
+	}
+
 	public void writeBoolean(boolean b) throws IOException {
 		if(b) out.write(Tag.TRUE);
 		else out.write(Tag.FALSE);
@@ -156,9 +161,4 @@ class WriterImpl implements Writer {
 	public void writeNull() throws IOException {
 		out.write(Tag.NULL);
 	}
-
-	public void close() throws IOException {
-		out.flush();
-		out.close();
-	}
 }