Decoupled ProtocolReader (which belongs in the protocol component)

from PacketReader (which belongs in the transport component).

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

@@ -12,6 +12,7 @@ import net.sf.briar.api.protocol.Message;
 import net.sf.briar.api.protocol.MessageEncoder;
 import net.sf.briar.api.protocol.MessageId;
 import net.sf.briar.api.protocol.Offer;
+import net.sf.briar.api.protocol.ProtocolReaderFactory;
 import net.sf.briar.api.protocol.Request;
 import net.sf.briar.api.protocol.SubscriptionUpdate;
 import net.sf.briar.api.protocol.TransportUpdate;
@@ -28,11 +29,12 @@ public class ProtocolModule extends AbstractModule {
 		bind(AuthorFactory.class).to(AuthorFactoryImpl.class);
 		bind(BatchFactory.class).to(BatchFactoryImpl.class);
 		bind(GroupFactory.class).to(GroupFactoryImpl.class);
+		bind(MessageEncoder.class).to(MessageEncoderImpl.class);
 		bind(OfferFactory.class).to(OfferFactoryImpl.class);
+		bind(ProtocolReaderFactory.class).to(ProtocolReaderFactoryImpl.class);
 		bind(RequestFactory.class).to(RequestFactoryImpl.class);
 		bind(SubscriptionFactory.class).to(SubscriptionFactoryImpl.class);
 		bind(TransportFactory.class).to(TransportFactoryImpl.class);
-		bind(MessageEncoder.class).to(MessageEncoderImpl.class);
 	}
 
 	@Provides

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

@@ -0,0 +1,51 @@
+package net.sf.briar.protocol;
+
+import java.io.InputStream;
+
+import net.sf.briar.api.protocol.Ack;
+import net.sf.briar.api.protocol.Batch;
+import net.sf.briar.api.protocol.Offer;
+import net.sf.briar.api.protocol.ProtocolReader;
+import net.sf.briar.api.protocol.ProtocolReaderFactory;
+import net.sf.briar.api.protocol.Request;
+import net.sf.briar.api.protocol.SubscriptionUpdate;
+import net.sf.briar.api.protocol.TransportUpdate;
+import net.sf.briar.api.serial.ObjectReader;
+import net.sf.briar.api.serial.ReaderFactory;
+
+import com.google.inject.Inject;
+import com.google.inject.Provider;
+
+class ProtocolReaderFactoryImpl implements ProtocolReaderFactory {
+
+	private final ReaderFactory readerFactory;
+	private final Provider<ObjectReader<Ack>> ackProvider;
+	private final Provider<ObjectReader<Batch>> batchProvider;
+	private final Provider<ObjectReader<Offer>> offerProvider;
+	private final Provider<ObjectReader<Request>> requestProvider;
+	private final Provider<ObjectReader<SubscriptionUpdate>> subscriptionProvider;
+	private final Provider<ObjectReader<TransportUpdate>> transportProvider;
+
+	@Inject
+	ProtocolReaderFactoryImpl(ReaderFactory readerFactory,
+			Provider<ObjectReader<Ack>> ackProvider,
+			Provider<ObjectReader<Batch>> batchProvider,
+			Provider<ObjectReader<Offer>> offerProvider,
+			Provider<ObjectReader<Request>> requestProvider,
+			Provider<ObjectReader<SubscriptionUpdate>> subscriptionProvider,
+			Provider<ObjectReader<TransportUpdate>> transportProvider) {
+		this.readerFactory = readerFactory;
+		this.ackProvider = ackProvider;
+		this.batchProvider = batchProvider;
+		this.offerProvider = offerProvider;
+		this.requestProvider = requestProvider;
+		this.subscriptionProvider = subscriptionProvider;
+		this.transportProvider = transportProvider;
+	}
+
+	public ProtocolReader createProtocolReader(InputStream in) {
+		return new ProtocolReaderImpl(in, readerFactory, ackProvider.get(),
+				batchProvider.get(), offerProvider.get(), requestProvider.get(),
+				subscriptionProvider.get(), transportProvider.get());
+	}
+}

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

@@ -0,0 +1,85 @@
+package net.sf.briar.protocol;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import net.sf.briar.api.protocol.Ack;
+import net.sf.briar.api.protocol.Batch;
+import net.sf.briar.api.protocol.Offer;
+import net.sf.briar.api.protocol.ProtocolReader;
+import net.sf.briar.api.protocol.Request;
+import net.sf.briar.api.protocol.SubscriptionUpdate;
+import net.sf.briar.api.protocol.Tags;
+import net.sf.briar.api.protocol.TransportUpdate;
+import net.sf.briar.api.serial.ObjectReader;
+import net.sf.briar.api.serial.Reader;
+import net.sf.briar.api.serial.ReaderFactory;
+
+class ProtocolReaderImpl implements ProtocolReader {
+
+	private final Reader reader;
+
+	ProtocolReaderImpl(InputStream in, ReaderFactory readerFactory,
+			ObjectReader<Ack> ackReader, ObjectReader<Batch> batchReader,
+			ObjectReader<Offer> offerReader,
+			ObjectReader<Request> requestReader,
+			ObjectReader<SubscriptionUpdate> subscriptionReader,
+			ObjectReader<TransportUpdate> transportReader) {
+		reader = readerFactory.createReader(in);
+		reader.addObjectReader(Tags.ACK, ackReader);
+		reader.addObjectReader(Tags.BATCH, batchReader);
+		reader.addObjectReader(Tags.OFFER, offerReader);
+		reader.addObjectReader(Tags.REQUEST, requestReader);
+		reader.addObjectReader(Tags.SUBSCRIPTIONS, subscriptionReader);
+		reader.addObjectReader(Tags.TRANSPORTS, transportReader);
+	}
+
+	public boolean hasAck() throws IOException {
+		return reader.hasUserDefined(Tags.ACK);
+	}
+
+	public Ack readAck() throws IOException {
+		return reader.readUserDefined(Tags.ACK, Ack.class);
+	}
+
+	public boolean hasBatch() throws IOException {
+		return reader.hasUserDefined(Tags.BATCH);
+	}
+
+	public Batch readBatch() throws IOException {
+		return reader.readUserDefined(Tags.BATCH, Batch.class);
+	}
+
+	public boolean hasOffer() throws IOException {
+		return reader.hasUserDefined(Tags.OFFER);
+	}
+
+	public Offer readOffer() throws IOException {
+		return reader.readUserDefined(Tags.OFFER, Offer.class);
+	}
+
+	public boolean hasRequest() throws IOException {
+		return reader.hasUserDefined(Tags.REQUEST);
+	}
+
+	public Request readRequest() throws IOException {
+		return reader.readUserDefined(Tags.REQUEST, Request.class);
+	}
+
+	public boolean hasSubscriptionUpdate() throws IOException {
+		return reader.hasUserDefined(Tags.SUBSCRIPTIONS);
+	}
+
+	public SubscriptionUpdate readSubscriptionUpdate() throws IOException {
+		return reader.readUserDefined(Tags.SUBSCRIPTIONS,
+				SubscriptionUpdate.class);
+	}
+
+	public boolean hasTransportUpdate() throws IOException {
+		return reader.hasUserDefined(Tags.TRANSPORTS);
+	}
+
+	public TransportUpdate readTransportUpdate() throws IOException {
+		return reader.readUserDefined(Tags.TRANSPORTS, TransportUpdate.class);
+	}
+}

components/net/sf/briar/transport/PacketDecrypter.java

@@ -8,6 +8,10 @@ interface PacketDecrypter {
 	/** Returns the input stream from which packets should be read. */
 	InputStream getInputStream();
 
-	/** Reads, decrypts and returns a tag from the underlying input stream. */
+	/**
+	 * Reads, decrypts and returns a tag from the underlying input stream.
+	 * Returns null if the end of the input stream is reached before any bytes
+	 * are read.
+	 */
 	byte[] readTag() throws IOException;
 }

components/net/sf/briar/transport/PacketDecrypterImpl.java

@@ -54,9 +54,11 @@ class PacketDecrypterImpl extends FilterInputStream implements PacketDecrypter {
 		bufOff = bufLen = 0;
 		while(offset < tag.length) {
 			int read = in.read(tag, offset, tag.length - offset);
-			if(read == -1) throw new EOFException();
+			if(read == -1) break;
 			offset += read;
 		}
+		if(offset == 0) return null; // EOF between packets is acceptable
+		if(offset < tag.length) throw new EOFException();
 		betweenPackets = false;
 		try {
 			byte[] decryptedTag = tagCipher.doFinal(tag);

components/net/sf/briar/transport/PacketReaderFactoryImpl.java

@@ -8,47 +8,18 @@ import javax.crypto.Mac;
 import javax.crypto.SecretKey;
 
 import net.sf.briar.api.crypto.CryptoComponent;
-import net.sf.briar.api.protocol.Ack;
-import net.sf.briar.api.protocol.Batch;
-import net.sf.briar.api.protocol.Offer;
-import net.sf.briar.api.protocol.Request;
-import net.sf.briar.api.protocol.SubscriptionUpdate;
-import net.sf.briar.api.protocol.TransportUpdate;
-import net.sf.briar.api.serial.ObjectReader;
-import net.sf.briar.api.serial.ReaderFactory;
 import net.sf.briar.api.transport.PacketReader;
 import net.sf.briar.api.transport.PacketReaderFactory;
 
 import com.google.inject.Inject;
-import com.google.inject.Provider;
 
 class PacketReaderFactoryImpl implements PacketReaderFactory {
 
 	private final CryptoComponent crypto;
-	private final ReaderFactory readerFactory;
-	private final Provider<ObjectReader<Ack>> ackProvider;
-	private final Provider<ObjectReader<Batch>> batchProvider;
-	private final Provider<ObjectReader<Offer>> offerProvider;
-	private final Provider<ObjectReader<Request>> requestProvider;
-	private final Provider<ObjectReader<SubscriptionUpdate>> subscriptionProvider;
-	private final Provider<ObjectReader<TransportUpdate>> transportProvider;
 
 	@Inject
-	PacketReaderFactoryImpl(CryptoComponent crypto, ReaderFactory readerFactory,
-			Provider<ObjectReader<Ack>> ackProvider,
-			Provider<ObjectReader<Batch>> batchProvider,
-			Provider<ObjectReader<Offer>> offerProvider,
-			Provider<ObjectReader<Request>> requestProvider,
-			Provider<ObjectReader<SubscriptionUpdate>> subscriptionProvider,
-			Provider<ObjectReader<TransportUpdate>> transportProvider) {
+	PacketReaderFactoryImpl(CryptoComponent crypto) {
 		this.crypto = crypto;
-		this.readerFactory = readerFactory;
-		this.ackProvider = ackProvider;
-		this.batchProvider = batchProvider;
-		this.offerProvider = offerProvider;
-		this.requestProvider = requestProvider;
-		this.subscriptionProvider = subscriptionProvider;
-		this.transportProvider = transportProvider;
 	}
 
 	public PacketReader createPacketReader(byte[] firstTag, InputStream in,
@@ -66,9 +37,6 @@ class PacketReaderFactoryImpl implements PacketReaderFactory {
 		}
 		PacketDecrypter decrypter = new PacketDecrypterImpl(firstTag, in,
 				tagCipher, packetCipher, tagKey, packetKey);
-		return new PacketReaderImpl(firstTag, readerFactory, ackProvider.get(),
-				batchProvider.get(), offerProvider.get(), requestProvider.get(),
-				subscriptionProvider.get(), transportProvider.get(),
-				decrypter, mac, transportId, connection);
+		return new PacketReaderImpl(decrypter, mac, transportId, connection);
 	}
 }

components/net/sf/briar/transport/PacketReaderImpl.java

@@ -1,27 +1,18 @@
 package net.sf.briar.transport;
 
+import java.io.FilterInputStream;
 import java.io.IOException;
 import java.io.InputStream;
+import java.security.GeneralSecurityException;
 import java.util.Arrays;
 
 import javax.crypto.Mac;
 
-import net.sf.briar.api.protocol.Ack;
-import net.sf.briar.api.protocol.Batch;
-import net.sf.briar.api.protocol.Offer;
-import net.sf.briar.api.protocol.Request;
-import net.sf.briar.api.protocol.SubscriptionUpdate;
-import net.sf.briar.api.protocol.Tags;
-import net.sf.briar.api.protocol.TransportUpdate;
 import net.sf.briar.api.serial.FormatException;
-import net.sf.briar.api.serial.ObjectReader;
-import net.sf.briar.api.serial.Reader;
-import net.sf.briar.api.serial.ReaderFactory;
 import net.sf.briar.api.transport.PacketReader;
 
-class PacketReaderImpl implements PacketReader {
+class PacketReaderImpl extends FilterInputStream implements PacketReader {
 
-	private final Reader reader;
 	private final PacketDecrypter decrypter;
 	private final Mac mac;
 	private final int macLength, transportId;
@@ -30,23 +21,9 @@ class PacketReaderImpl implements PacketReader {
 	private long packet = 0L;
 	private boolean betweenPackets = true;
 
-	PacketReaderImpl(byte[] firstTag, ReaderFactory readerFactory,
-			ObjectReader<Ack> ackReader, ObjectReader<Batch> batchReader,
-			ObjectReader<Offer> offerReader,
-			ObjectReader<Request> requestReader,
-			ObjectReader<SubscriptionUpdate> subscriptionReader,
-			ObjectReader<TransportUpdate> transportReader,
-			PacketDecrypter decrypter, Mac mac, int transportId,
+	PacketReaderImpl(PacketDecrypter decrypter, Mac mac, int transportId,
 			long connection) {
-		InputStream in = decrypter.getInputStream();
-		reader = readerFactory.createReader(in);
-		reader.addObjectReader(Tags.ACK, ackReader);
-		reader.addObjectReader(Tags.BATCH, batchReader);
-		reader.addObjectReader(Tags.OFFER, offerReader);
-		reader.addObjectReader(Tags.REQUEST, requestReader);
-		reader.addObjectReader(Tags.SUBSCRIPTIONS, subscriptionReader);
-		reader.addObjectReader(Tags.TRANSPORTS, transportReader);
-		reader.addConsumer(new MacConsumer(mac));
+		super(decrypter.getInputStream());
 		this.decrypter = decrypter;
 		this.mac = mac;
 		macLength = mac.getMacLength();
@@ -54,32 +31,36 @@ class PacketReaderImpl implements PacketReader {
 		this.connection = connection;
 	}
 
-	public boolean hasAck() throws IOException {
+	public InputStream getInputStream() {
+		return this;
+	}
+
+	public void finishPacket() throws IOException, GeneralSecurityException {
+		if(!betweenPackets) readMac();
+	}
+
+	@Override
+	public int read() throws IOException {
 		if(betweenPackets) readTag();
-		return reader.hasUserDefined(Tags.ACK);
+		int i = in.read();
+		if(i != -1) mac.update((byte) i);
+		return i;
 	}
 
-	private void readTag() throws IOException {
-		assert betweenPackets;
-		if(packet > Constants.MAX_32_BIT_UNSIGNED)
-			throw new IllegalStateException();
-		byte[] tag = decrypter.readTag();
-		if(!TagDecoder.decodeTag(tag, transportId, connection, packet))
-			throw new FormatException();
-		mac.update(tag);
-		packet++;
-		betweenPackets = false;
+	@Override
+	public int read(byte[] b) throws IOException {
+		return read(b, 0, b.length);
 	}
 
-	public Ack readAck() throws IOException {
+	@Override
+	public int read(byte[] b, int off, int len) throws IOException {
 		if(betweenPackets) readTag();
-		Ack a = reader.readUserDefined(Tags.ACK, Ack.class);
-		readMac();
-		betweenPackets = true;
-		return a;
+		int i = in.read(b, off, len);
+		if(i != -1) mac.update(b, off, i);
+		return i;
 	}
 
-	private void readMac() throws IOException {
+	private void readMac() throws IOException, GeneralSecurityException {
 		byte[] expectedMac = mac.doFinal();
 		byte[] actualMac = new byte[macLength];
 		InputStream in = decrypter.getInputStream();
@@ -89,74 +70,22 @@ class PacketReaderImpl implements PacketReader {
 			if(read == -1) break;
 			offset += read;
 		}
-		if(offset < macLength) throw new FormatException();
-		if(!Arrays.equals(expectedMac, actualMac)) throw new FormatException();
-	}
-
-	public boolean hasBatch() throws IOException {
-		if(betweenPackets) readTag();
-		return reader.hasUserDefined(Tags.BATCH);
-	}
-
-	public Batch readBatch() throws IOException {
-		if(betweenPackets) readTag();
-		Batch b = reader.readUserDefined(Tags.BATCH, Batch.class);
-		readMac();
+		if(offset < macLength) throw new GeneralSecurityException();
+		if(!Arrays.equals(expectedMac, actualMac))
+			throw new GeneralSecurityException();
 		betweenPackets = true;
-		return b;
 	}
 
-	public boolean hasOffer() throws IOException {
-		if(betweenPackets) readTag();
-		return reader.hasUserDefined(Tags.OFFER);
-	}
-
-	public Offer readOffer() throws IOException {
-		if(betweenPackets) readTag();
-		Offer o = reader.readUserDefined(Tags.OFFER, Offer.class);
-		readMac();
-		betweenPackets = true;
-		return o;
-	}
-
-	public boolean hasRequest() throws IOException {
-		if(betweenPackets) readTag();
-		return reader.hasUserDefined(Tags.REQUEST);
-	}
-
-	public Request readRequest() throws IOException {
-		if(betweenPackets) readTag();
-		Request r = reader.readUserDefined(Tags.REQUEST, Request.class);
-		readMac();
-		betweenPackets = true;
-		return r;
-	}
-
-	public boolean hasSubscriptionUpdate() throws IOException {
-		if(betweenPackets) readTag();
-		return reader.hasUserDefined(Tags.SUBSCRIPTIONS);
-	}
-
-	public SubscriptionUpdate readSubscriptionUpdate() throws IOException {
-		if(betweenPackets) readTag();
-		SubscriptionUpdate s = reader.readUserDefined(Tags.SUBSCRIPTIONS,
-				SubscriptionUpdate.class);
-		readMac();
-		betweenPackets = true;
-		return s;
-	}
-
-	public boolean hasTransportUpdate() throws IOException {
-		if(betweenPackets) readTag();
-		return reader.hasUserDefined(Tags.TRANSPORTS);
-	}
-
-	public TransportUpdate readTransportUpdate() throws IOException {
-		if(betweenPackets) readTag();
-		TransportUpdate t = reader.readUserDefined(Tags.TRANSPORTS,
-				TransportUpdate.class);
-		readMac();
-		betweenPackets = true;
-		return t;
+	private void readTag() throws IOException {
+		assert betweenPackets;
+		if(packet > Constants.MAX_32_BIT_UNSIGNED)
+			throw new IllegalStateException();
+		byte[] tag = decrypter.readTag();
+		if(tag == null) return; // EOF
+		if(!TagDecoder.decodeTag(tag, transportId, connection, packet))
+			throw new FormatException();
+		mac.update(tag);
+		packet++;
+		betweenPackets = false;
 	}
 }

components/net/sf/briar/transport/PacketWriterImpl.java

@@ -37,7 +37,7 @@ class PacketWriterImpl extends FilterOutputStream implements PacketWriter {
 		return this;
 	}
 
-	public void nextPacket() throws IOException {
+	public void finishPacket() throws IOException {
 		if(!betweenPackets) writeMac();
 	}
 
@@ -50,9 +50,7 @@ class PacketWriterImpl extends FilterOutputStream implements PacketWriter {
 
 	@Override
 	public void write(byte[] b) throws IOException {
-		if(betweenPackets) writeTag();
-		out.write(b);
-		mac.update(b);
+		write(b, 0, b.length);
 	}
 
 	@Override