Implemented KeyManager (untested).

A test is failing due to key derivation errors - must be fixed!

components/net/sf/briar/crypto/KeyRotator.java

@@ -1,24 +0,0 @@
-package net.sf.briar.crypto;
-
-import net.sf.briar.api.db.DbException;
-
-interface KeyRotator {
-
-	/**
-	 * Starts a new thread to rotate keys periodically. The rotator will pause
-	 * for the given number of milliseconds between rotations.
-	 */
-	void startRotating(Callback callback, long msBetweenRotations);
-
-	/** Tells the rotator thread to exit. */
-	void stopRotating();
-
-	interface Callback {
-
-		/**
-		 * Rotates keys, replacing and destroying any keys that have passed the
-		 * ends of their respective retention periods.
-		 */
-		void rotateKeys() throws DbException;
-	}
-}

components/net/sf/briar/crypto/KeyRotatorImpl.java

@@ -1,41 +0,0 @@
-package net.sf.briar.crypto;
-
-import java.util.Timer;
-import java.util.TimerTask;
-import java.util.logging.Level;
-import java.util.logging.Logger;
-
-import net.sf.briar.api.db.DbException;
-
-class KeyRotatorImpl extends TimerTask implements KeyRotator {
-
-	private static final Logger LOG =
-			Logger.getLogger(KeyRotatorImpl.class.getName());
-
-	private volatile Callback callback = null;
-	private volatile Timer timer = null;
-
-	public void startRotating(Callback callback, long msBetweenRotations) {
-		this.callback = callback;
-		timer = new Timer();
-		timer.scheduleAtFixedRate(this, 0L, msBetweenRotations);
-	}
-
-	public void stopRotating() {
-		if(timer == null) throw new IllegalStateException();
-		timer.cancel();
-	}
-
-	public void run() {
-		if(callback == null) throw new IllegalStateException();
-		try {
-			callback.rotateKeys();
-		} catch(DbException e) {
-			if(LOG.isLoggable(Level.WARNING)) LOG.warning(e.toString());
-			throw new Error(e); // Kill the application
-		} catch(RuntimeException e) {
-			if(LOG.isLoggable(Level.WARNING)) LOG.warning(e.toString());
-			throw new Error(e); // Kill the application
-		}
-	}
-}

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

@@ -468,11 +468,11 @@ interface Database<T> {
 
 	/**
 	 * Increments the outgoing connection counter for the given contact
-	 * transport in the given rotation period.
+	 * transport in the given rotation period and returns the old value;
 	 * <p>
 	 * Locking: contact read, window write.
 	 */
-	void incrementConnectionCounter(T txn, ContactId c, TransportId t,
+	long incrementConnectionCounter(T txn, ContactId c, TransportId t,
 			long period) throws DbException;
 
 	/**

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

@@ -758,30 +758,6 @@ DatabaseCleaner.Callback {
 		}
 	}
 
-	public Collection<ContactTransport> getContactTransports()
-			throws DbException {
-		contactLock.readLock().lock();
-		try {
-			windowLock.readLock().lock();
-			try {
-				T txn = db.startTransaction();
-				try {
-					Collection<ContactTransport> contactTransports =
-							db.getContactTransports(txn);
-					db.commitTransaction(txn);
-					return contactTransports;
-				} catch(DbException e) {
-					db.abortTransaction(txn);
-					throw e;
-				}
-			} finally {
-				windowLock.readLock().unlock();
-			}
-		} finally {
-			contactLock.readLock().unlock();
-		}
-	}
-
 	public TransportProperties getLocalProperties(TransportId t)
 			throws DbException {
 		transportLock.readLock().lock();
@@ -1005,7 +981,7 @@ DatabaseCleaner.Callback {
 		}
 	}
 
-	public void incrementConnectionCounter(ContactId c, TransportId t,
+	public long incrementConnectionCounter(ContactId c, TransportId t,
 			long period) throws DbException {
 		contactLock.readLock().lock();
 		try {
@@ -1015,8 +991,9 @@ DatabaseCleaner.Callback {
 				try {
 					if(!db.containsContactTransport(txn, c, t))
 						throw new NoSuchContactTransportException();
-					db.incrementConnectionCounter(txn, c, t, period);
+					long l = db.incrementConnectionCounter(txn, c, t, period);
 					db.commitTransaction(txn);
+					return l;
 				} catch(DbException e) {
 					db.abortTransaction(txn);
 					throw e;

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

@@ -1557,22 +1557,30 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT contactId, transportId, period, secret,"
-					+ " outgoing, centre, bitmap"
-					+ " FROM secrets";
+			String sql = "SELECT ct.contactId, ct.transportId, epoch,"
+					+ " clockDiff, latency, alice, period, secret, outgoing,"
+					+ " centre, bitmap"
+					+ " FROM contactTransports AS ct"
+					+ " JOIN secrets AS s"
+					+ " ON ct.contactId = s.contactId"
+					+ " AND ct.transportId = s.transportId";
 			ps = txn.prepareStatement(sql);
 			rs = ps.executeQuery();
 			List<TemporarySecret> secrets = new ArrayList<TemporarySecret>();
 			while(rs.next()) {
 				ContactId c = new ContactId(rs.getInt(1));
 				TransportId t = new TransportId(rs.getBytes(2));
-				long period = rs.getLong(3);
-				byte[] secret = rs.getBytes(4);
-				long outgoing = rs.getLong(5);
-				long centre = rs.getLong(6);
-				byte[] bitmap = rs.getBytes(7);
-				secrets.add(new TemporarySecret(c, t, period, secret, outgoing,
-						centre, bitmap));
+				long epoch = rs.getLong(3);
+				long clockDiff = rs.getLong(4);
+				long latency = rs.getLong(5);
+				boolean alice = rs.getBoolean(6);
+				long period = rs.getLong(7);
+				byte[] secret = rs.getBytes(8);
+				long outgoing = rs.getLong(9);
+				long centre = rs.getLong(10);
+				byte[] bitmap = rs.getBytes(11);
+				secrets.add(new TemporarySecret(c, t, epoch, clockDiff, latency,
+						alice, period, secret, outgoing, centre, bitmap));
 			}
 			rs.close();
 			ps.close();
@@ -2021,11 +2029,26 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	public void incrementConnectionCounter(Connection txn, ContactId c,
+	public long incrementConnectionCounter(Connection txn, ContactId c,
 			TransportId t, long period) throws DbException {
 		PreparedStatement ps = null;
+		ResultSet rs = null;
 		try {
-			String sql = "UPDATE secrets SET outgoing = outgoing + 1"
+			// Get the current connection counter
+			String sql = "SELECT outgoing FROM secrets"
+					+ " WHERE contactId = ? AND transportId = ? AND period + ?";
+			ps = txn.prepareStatement(sql);
+			ps.setInt(1, c.getInt());
+			ps.setBytes(2, t.getBytes());
+			ps.setLong(3, period);
+			rs = ps.executeQuery();
+			if(!rs.next()) throw new DbStateException();
+			long connection = rs.getLong(1);
+			if(rs.next()) throw new DbStateException();
+			rs.close();
+			ps.close();
+			// Increment the connection counter
+			sql = "UPDATE secrets SET outgoing = outgoing + 1"
 					+ " WHERE contactId = ? AND transportId = ? AND period = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
@@ -2034,8 +2057,10 @@ abstract class JdbcDatabase implements Database<Connection> {
 			int affected = ps.executeUpdate();
 			if(affected > 1) throw new DbStateException();
 			ps.close();
+			return connection;
 		} catch(SQLException e) {
 			tryToClose(ps);
+			tryToClose(rs);
 			throw new DbException(e);
 		}
 	}

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

@@ -7,6 +7,7 @@ import net.sf.briar.api.ContactId;
 import net.sf.briar.api.crypto.CryptoComponent;
 import net.sf.briar.api.db.DatabaseComponent;
 import net.sf.briar.api.db.DbException;
+import net.sf.briar.api.db.TemporarySecret;
 import net.sf.briar.api.protocol.TransportId;
 import net.sf.briar.api.transport.ConnectionContext;
 import net.sf.briar.api.transport.ConnectionRecogniser;
@@ -37,9 +38,8 @@ class ConnectionRecogniserImpl implements ConnectionRecogniser {
 		return r.acceptConnection(tag);
 	}
 
-	public void addWindow(ContactId c, TransportId t, long period,
-			boolean alice, byte[] secret, long centre, byte[] bitmap)
-					throws DbException {
+	public void addSecret(TemporarySecret s) throws DbException {
+		TransportId t = s.getTransportId();
 		TransportConnectionRecogniser r;
 		synchronized(this) {
 			r = recognisers.get(t);
@@ -48,20 +48,24 @@ class ConnectionRecogniserImpl implements ConnectionRecogniser {
 				recognisers.put(t, r);
 			}
 		}
-		r.addWindow(c, period, alice, secret, centre, bitmap);
+		r.addSecret(s);
 	}
 
-	public void removeWindow(ContactId c, TransportId t, long period) {
+	public void removeSecret(ContactId c, TransportId t, long period) {
 		TransportConnectionRecogniser r;
 		synchronized(this) {
 			r = recognisers.get(t);
 		}
-		if(r != null) r.removeWindow(c, period);
+		if(r != null) r.removeSecret(c, period);
 	}
 
-	public synchronized void removeWindows(ContactId c) {
-		for(TransportConnectionRecogniser r : recognisers.values()) {
-			r.removeWindows(c);
-		}
+	public synchronized void removeSecrets(ContactId c) {
+		for(TransportConnectionRecogniser r : recognisers.values())
+			r.removeSecrets(c);
+	}
+
+	public synchronized void removeSecrets() {
+		for(TransportConnectionRecogniser r : recognisers.values())
+			r.removeSecrets();
 	}
 }

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

@@ -13,6 +13,7 @@ import net.sf.briar.api.transport.ConnectionContext;
 import net.sf.briar.api.transport.ConnectionWriter;
 import net.sf.briar.api.transport.ConnectionWriterFactory;
 
+
 import com.google.inject.Inject;
 
 class ConnectionWriterFactoryImpl implements ConnectionWriterFactory {

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

@@ -6,6 +6,7 @@ import static net.sf.briar.api.transport.TransportConstants.MAC_LENGTH;
 import java.io.IOException;
 import java.io.OutputStream;
 
+
 import net.sf.briar.api.transport.ConnectionWriter;
 
 /**

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

@@ -0,0 +1,305 @@
+package net.sf.briar.transport;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Timer;
+import java.util.TimerTask;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import net.sf.briar.api.ContactId;
+import net.sf.briar.api.crypto.CryptoComponent;
+import net.sf.briar.api.crypto.KeyManager;
+import net.sf.briar.api.db.DatabaseComponent;
+import net.sf.briar.api.db.DbException;
+import net.sf.briar.api.db.TemporarySecret;
+import net.sf.briar.api.db.event.ContactRemovedEvent;
+import net.sf.briar.api.db.event.DatabaseEvent;
+import net.sf.briar.api.db.event.DatabaseListener;
+import net.sf.briar.api.protocol.TransportId;
+import net.sf.briar.api.transport.ConnectionContext;
+import net.sf.briar.api.transport.ConnectionRecogniser;
+import net.sf.briar.util.ByteUtils;
+
+import com.google.inject.Inject;
+
+class KeyManagerImpl extends TimerTask implements KeyManager, DatabaseListener {
+
+	private static final int MS_BETWEEN_CHECKS = 60 * 1000;
+
+	private static final Logger LOG =
+			Logger.getLogger(KeyManagerImpl.class.getName());
+
+	private final CryptoComponent crypto;
+	private final DatabaseComponent db;
+	private final ConnectionRecogniser recogniser;
+	private final Timer timer;
+	// Locking: this
+	private final Map<ContactTransportKey, TemporarySecret> outgoing;
+	// Locking: this
+	private final Map<ContactTransportKey, TemporarySecret> incomingOld;
+	// Locking: this
+	private final Map<ContactTransportKey, TemporarySecret> incomingNew;
+
+	// Locking: this
+	private boolean running = false;
+
+	@Inject
+	public KeyManagerImpl(CryptoComponent crypto, DatabaseComponent db,
+			ConnectionRecogniser recogniser) {
+		this.crypto = crypto;
+		this.db = db;
+		this.recogniser = recogniser;
+		timer = new Timer();
+		outgoing = new HashMap<ContactTransportKey, TemporarySecret>();
+		incomingOld = new HashMap<ContactTransportKey, TemporarySecret>();
+		incomingNew = new HashMap<ContactTransportKey, TemporarySecret>();
+	}
+
+	public synchronized boolean start() {
+		if(running) return false;
+		Collection<TemporarySecret> secrets;
+		try {
+			secrets = db.getSecrets();
+		} catch(DbException e) {
+			if(LOG.isLoggable(Level.WARNING)) LOG.warning(e.toString());
+			return false;
+		}
+		// Work out what phase of its lifecycle each secret is in
+		long now = System.currentTimeMillis();
+		Collection<TemporarySecret> dead = assignSecretsToMaps(now, secrets);
+		// Replace any dead secrets
+		Collection<TemporarySecret> created = replaceDeadSecrets(now, dead);
+		try {
+			// Store any secrets that have been created
+			if(!created.isEmpty()) db.addSecrets(created);
+			// Pass the current incoming secrets to the connection recogniser
+			// FIXME: This uses a separate database transaction for each secret
+			for(TemporarySecret s : incomingOld.values())
+				recogniser.addSecret(s);
+			for(TemporarySecret s : incomingNew.values())
+				recogniser.addSecret(s);
+		} catch(DbException e) {
+			if(LOG.isLoggable(Level.WARNING)) LOG.warning(e.toString());
+			return false;
+		}
+		// Schedule periodic key rotation
+		timer.scheduleAtFixedRate(this, MS_BETWEEN_CHECKS, MS_BETWEEN_CHECKS);
+		running = true;
+		return true;
+	}
+
+	// Assigns secrets to the appropriate maps and returns any dead secrets
+	// FIXME: Check there are no duplicate keys when updating maps
+	private Collection<TemporarySecret> assignSecretsToMaps(long now,
+			Collection<TemporarySecret> secrets) {
+		Collection<TemporarySecret> dead = new ArrayList<TemporarySecret>();
+		for(TemporarySecret s : secrets) {
+			ContactId c = s.getContactId();
+			TransportId t = s.getTransportId();
+			ContactTransportKey k = new ContactTransportKey(c, t);
+			long rotationPeriod = getRotationPeriod(s);
+			long creationTime = getCreationTime(s);
+			long activationTime = creationTime + s.getClockDifference();
+			long successorCreationTime = creationTime + rotationPeriod;
+			long deactivationTime = activationTime + rotationPeriod;
+			long destructionTime = successorCreationTime + rotationPeriod;
+			if(now >= destructionTime) {
+				dead.add(s);
+			} else if(now >= deactivationTime) {
+				incomingOld.put(k, s);
+			} else if(now >= successorCreationTime) {
+				incomingOld.put(k, s);
+				outgoing.put(k, s);
+			} else if(now >= activationTime) {
+				incomingNew.put(k, s);
+				outgoing.put(k, s);
+			} else if(now >= creationTime) {
+				incomingNew.put(k, s);
+			} else {
+				// FIXME: What should we do if the clock moves backwards?
+				throw new IllegalStateException();
+			}
+		}
+		return dead;
+	}
+
+	// Replaces and erases the given secrets and returns any secrets created
+	private Collection<TemporarySecret> replaceDeadSecrets(long now,
+			Collection<TemporarySecret> dead) {
+		Collection<TemporarySecret> created = new ArrayList<TemporarySecret>();
+		for(TemporarySecret s : dead) {
+			ContactId c = s.getContactId();
+			TransportId t = s.getTransportId();
+			ContactTransportKey k = new ContactTransportKey(c, t);
+			if(incomingNew.containsKey(k)) throw new IllegalStateException();
+			byte[] secret = s.getSecret();
+			long period = s.getPeriod();
+			if(incomingOld.containsKey(k)) {
+				// The dead secret's successor is still alive
+				byte[] secret1 = crypto.deriveNextSecret(secret, period + 1);
+				TemporarySecret s1 = new TemporarySecret(s, period + 1,
+						secret1);
+				created.add(s1);
+				incomingNew.put(k, s1);
+				long creationTime = getCreationTime(s1);
+				long activationTime = creationTime + s1.getClockDifference();
+				if(now >= activationTime) outgoing.put(k, s1);
+			} else  {
+				// The dead secret has no living successor
+				long rotationPeriod = getRotationPeriod(s);
+				long elapsed = now - s.getEpoch();
+				long currentPeriod = elapsed / rotationPeriod;
+				if(currentPeriod <= period) throw new IllegalStateException();
+				// Derive the two current incoming secrets
+				byte[] secret1, secret2;
+				secret1 = secret;
+				for(long l = period; l < currentPeriod; l++) {
+					byte[] temp = crypto.deriveNextSecret(secret1, l);
+					ByteUtils.erase(secret1);
+					secret1 = temp;
+				}
+				secret2 = crypto.deriveNextSecret(secret1, currentPeriod);
+				// One of the incoming secrets is the current outgoing secret
+				TemporarySecret s1, s2;
+				s1 = new TemporarySecret(s, currentPeriod - 1, secret1);
+				created.add(s1);
+				incomingOld.put(k, s1);
+				s2 = new TemporarySecret(s, currentPeriod, secret2);
+				created.add(s2);
+				incomingNew.put(k, s2);
+				if(elapsed % rotationPeriod < s.getClockDifference()) {
+					// The outgoing secret is the newer incoming secret
+					outgoing.put(k, s2);
+				} else {
+					// The outgoing secret is the older incoming secret
+					outgoing.put(k, s1);
+				}
+			}
+			// Erase the dead secret
+			ByteUtils.erase(secret);
+		}
+		return created;
+	}
+
+	private long getRotationPeriod(TemporarySecret s) {
+		return 2 * s.getClockDifference() + s.getLatency();
+	}
+
+	private long getCreationTime(TemporarySecret s) {
+		long rotationPeriod = getRotationPeriod(s);
+		return s.getEpoch() + rotationPeriod * s.getPeriod();
+	}
+
+	public synchronized void stop() {
+		if(!running) return;
+		recogniser.removeSecrets();
+		removeAndEraseSecrets(outgoing);
+		removeAndEraseSecrets(incomingOld);
+		removeAndEraseSecrets(incomingNew);
+		running = false;
+	}
+
+	// Locking: this
+	private void removeAndEraseSecrets(Map<?, TemporarySecret> m) {
+		for(TemporarySecret s : m.values()) ByteUtils.erase(s.getSecret());
+		m.clear();
+	}
+
+	public synchronized ConnectionContext getConnectionContext(ContactId c,
+			TransportId t) {
+		TemporarySecret s = outgoing.get(new ContactTransportKey(c, t));
+		if(s == null) return null;
+		long connection;
+		try {
+			connection = db.incrementConnectionCounter(c, t, s.getPeriod());
+		} catch(DbException e) {
+			if(LOG.isLoggable(Level.WARNING)) LOG.warning(e.toString());
+			return null;
+		}
+		byte[] secret = s.getSecret().clone();
+		return new ConnectionContext(c, t, secret, connection, s.getAlice());
+	}
+
+	@Override
+	public synchronized void run() {
+		// Rebuild the maps because we may be running a whole period late
+		Collection<TemporarySecret> secrets = new ArrayList<TemporarySecret>();
+		secrets.addAll(incomingOld.values());
+		secrets.addAll(incomingNew.values());
+		outgoing.clear();
+		incomingOld.clear();
+		incomingNew.clear();
+		// Work out what phase of its lifecycle each secret is in
+		long now = System.currentTimeMillis();
+		Collection<TemporarySecret> dead = assignSecretsToMaps(now, secrets);
+		// Replace any dead secrets
+		Collection<TemporarySecret> created = replaceDeadSecrets(now, dead);
+		try {
+			// Store any secrets that have been created
+			if(!created.isEmpty()) db.addSecrets(created);
+			// Pass the current incoming secrets to the connection recogniser
+			// FIXME: This uses a separate database transaction for each secret
+			for(TemporarySecret s : incomingOld.values())
+				recogniser.addSecret(s);
+			for(TemporarySecret s : incomingNew.values())
+				recogniser.addSecret(s);
+		} catch(DbException e) {
+			if(LOG.isLoggable(Level.WARNING)) LOG.warning(e.toString());
+		}
+	}
+
+	public void eventOccurred(DatabaseEvent e) {
+		if(e instanceof ContactRemovedEvent) {
+			ContactId c = ((ContactRemovedEvent) e).getContactId();
+			recogniser.removeSecrets(c);
+			synchronized(this) {
+				removeAndEraseSecrets(c, outgoing);
+				removeAndEraseSecrets(c, incomingOld);
+				removeAndEraseSecrets(c, incomingNew);
+			}
+		}
+	}
+
+	// Locking: this
+	private void removeAndEraseSecrets(ContactId c, Map<?, TemporarySecret> m) {
+		Iterator<TemporarySecret> it = m.values().iterator();
+		while(it.hasNext()) {
+			TemporarySecret s = it.next();
+			if(s.getContactId().equals(c)) {
+				ByteUtils.erase(s.getSecret());
+				it.remove();
+			}
+		}
+	}
+
+	private static class ContactTransportKey {
+
+		private final ContactId contactId;
+		private final TransportId transportId;
+
+		private ContactTransportKey(ContactId contactId,
+				TransportId transportId) {
+			this.contactId = contactId;
+			this.transportId = transportId;
+		}
+
+		@Override
+		public int hashCode() {
+			return contactId.hashCode() + transportId.hashCode();
+		}
+
+		@Override
+		public boolean equals(Object o) {
+			if(o instanceof ContactTransportKey) {
+				ContactTransportKey k = (ContactTransportKey) o;
+				return contactId.equals(k.contactId) &&
+						transportId.equals(k.transportId);
+			}
+			return false;
+		}
+	}
+}

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

@@ -11,6 +11,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.security.GeneralSecurityException;
 
+
 import net.sf.briar.api.crypto.AuthenticatedCipher;
 import net.sf.briar.api.crypto.ErasableKey;
 

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

@@ -15,6 +15,7 @@ import net.sf.briar.api.crypto.CryptoComponent;
 import net.sf.briar.api.crypto.ErasableKey;
 import net.sf.briar.api.db.DatabaseComponent;
 import net.sf.briar.api.db.DbException;
+import net.sf.briar.api.db.TemporarySecret;
 import net.sf.briar.api.protocol.TransportId;
 import net.sf.briar.api.transport.ConnectionContext;
 import net.sf.briar.util.ByteUtils;
@@ -74,8 +75,13 @@ class TransportConnectionRecogniser {
 		return ctx;
 	}
 
-	synchronized void addWindow(ContactId contactId, long period, boolean alice,
-			byte[] secret, long centre, byte[] bitmap) throws DbException {
+	synchronized void addSecret(TemporarySecret s) throws DbException {
+		ContactId contactId = s.getContactId();
+		long period = s.getPeriod();
+		byte[] secret = s.getSecret();
+		boolean alice = s.getAlice();
+		long centre = s.getWindowCentre();
+		byte[] bitmap = s.getWindowBitmap();
 		// Create the connection window and the expected tags
 		Cipher cipher = crypto.getTagCipher();
 		ErasableKey key = crypto.deriveTagKey(secret, alice);
@@ -96,10 +102,15 @@ class TransportConnectionRecogniser {
 		removalMap.put(new RemovalKey(contactId, period), rctx);
 	}
 
-	synchronized void removeWindow(ContactId contactId, long period) {
+	synchronized void removeSecret(ContactId contactId, long period) {
 		RemovalKey rk = new RemovalKey(contactId, period);
 		RemovalContext rctx = removalMap.remove(rk);
 		if(rctx == null) throw new IllegalArgumentException();
+		removeSecret(rctx);
+	}
+
+	// Locking: this
+	private void removeSecret(RemovalContext rctx) {
 		// Remove the expected tags
 		Cipher cipher = crypto.getTagCipher();
 		ErasableKey key = crypto.deriveTagKey(rctx.secret, rctx.alice);
@@ -114,12 +125,18 @@ class TransportConnectionRecogniser {
 		ByteUtils.erase(rctx.secret);
 	}
 
-	synchronized void removeWindows(ContactId c) {
+	synchronized void removeSecrets(ContactId c) {
 		Collection<RemovalKey> keysToRemove = new ArrayList<RemovalKey>();
 		for(RemovalKey k : removalMap.keySet()) {
 			if(k.contactId.equals(c)) keysToRemove.add(k);
 		}
-		for(RemovalKey k : keysToRemove) removeWindow(k.contactId, k.period);
+		for(RemovalKey k : keysToRemove) removeSecret(k.contactId, k.period);
+	}
+
+	synchronized void removeSecrets() {
+		for(RemovalContext rctx : removalMap.values()) removeSecret(rctx);
+		assert tagMap.isEmpty();
+		removalMap.clear();
 	}
 
 	private static class WindowContext {
@@ -148,7 +165,7 @@ class TransportConnectionRecogniser {
 
 		@Override
 		public int hashCode() {
-			return contactId.hashCode()+ (int) period;
+			return contactId.hashCode() + (int) period;
 		}
 
 		@Override

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

@@ -3,13 +3,16 @@ package net.sf.briar.transport;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Executors;
 
+import net.sf.briar.api.crypto.KeyManager;
 import net.sf.briar.api.transport.ConnectionDispatcher;
 import net.sf.briar.api.transport.ConnectionReaderFactory;
+import net.sf.briar.api.transport.ConnectionRecogniser;
 import net.sf.briar.api.transport.ConnectionRegistry;
 import net.sf.briar.api.transport.ConnectionWriterFactory;
 import net.sf.briar.api.transport.IncomingConnectionExecutor;
 
 import com.google.inject.AbstractModule;
+import com.google.inject.Singleton;
 
 public class TransportModule extends AbstractModule {
 
@@ -18,6 +21,8 @@ public class TransportModule extends AbstractModule {
 		bind(ConnectionDispatcher.class).to(ConnectionDispatcherImpl.class);
 		bind(ConnectionReaderFactory.class).to(
 				ConnectionReaderFactoryImpl.class);
+		bind(ConnectionRecogniser.class).to(ConnectionRecogniserImpl.class).in(
+				Singleton.class);
 		bind(ConnectionRegistry.class).toInstance(new ConnectionRegistryImpl());
 		bind(ConnectionWriterFactory.class).to(
 				ConnectionWriterFactoryImpl.class);
@@ -25,5 +30,6 @@ public class TransportModule extends AbstractModule {
 		bind(Executor.class).annotatedWith(
 				IncomingConnectionExecutor.class).toInstance(
 						Executors.newCachedThreadPool());
+		bind(KeyManager.class).to(KeyManagerImpl.class).in(Singleton.class);
 	}
 }