Merge branch '1556-key-manager-methods-for-pending-contacts' into 'master'

Add key manager methods for pending contacts

Closes #1556

See merge request !1089

bramble-api/src/main/java/org/briarproject/bramble/api/Bytes.java

@@ -6,6 +6,7 @@ import org.briarproject.bramble.util.StringUtils;
 import java.util.Arrays;
 import java.util.Comparator;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**
@@ -38,7 +39,7 @@ public class Bytes implements Comparable<Bytes> {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		return o instanceof Bytes && Arrays.equals(bytes, ((Bytes) o).bytes);
 	}
 

bramble-api/src/main/java/org/briarproject/bramble/api/contact/ContactId.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.api.contact;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
 /**
@@ -28,7 +29,7 @@ public class ContactId {
 	}
 
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		return o instanceof ContactId && id == ((ContactId) o).id;
 	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/contact/PendingContactId.java

@@ -3,6 +3,7 @@ package org.briarproject.bramble.api.contact;
 import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**
@@ -17,9 +18,8 @@ public class PendingContactId extends UniqueId {
 		super(id);
 	}
 
-
 	@Override
-	public boolean equals(Object o) {
+	public boolean equals(@Nullable Object o) {
 		return o instanceof PendingContactId && super.equals(o);
 	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/nullsafety/NullSafety.java

@@ -6,10 +6,20 @@ import javax.annotation.Nullable;
 public class NullSafety {
 
 	/**
-	 * Stand-in for `Objects.requireNonNull()`.
+	 * Stand-in for {@code Objects.requireNonNull()}.
 	 */
 	public static <T> T requireNonNull(@Nullable T t) {
 		if (t == null) throw new NullPointerException();
 		return t;
 	}
+
+	/**
+	 * Checks that exactly one of the arguments is null.
+	 *
+	 * @throws AssertionError If both or neither of the arguments are null
+	 */
+	public static void requireExactlyOneNull(@Nullable Object a,
+			@Nullable Object b) {
+		if ((a == null) == (b == null)) throw new AssertionError();
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/transport/KeyManager.java

 package org.briarproject.bramble.api.transport;
 
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
@@ -18,17 +19,45 @@ public interface KeyManager {
 
 	/**
 	 * Informs the key manager that a new contact has been added. Derives and
-	 * stores a set of transport keys for communicating with the contact over
-	 * each transport and returns the key set IDs.
+	 * stores a set of rotation mode transport keys for communicating with the
+	 * contact over each transport and returns the key set IDs.
 	 * <p/>
 	 * {@link StreamContext StreamContexts} for the contact can be created
 	 * after this method has returned.
 	 *
-	 * @param alice true if the local party is Alice
-	 * @param active whether the derived keys can be used for outgoing streams
+	 * @param alice True if the local party is Alice
+	 * @param active Whether the derived keys can be used for outgoing streams
 	 */
-	Map<TransportId, KeySetId> addContact(Transaction txn, ContactId c,
-			SecretKey rootKey, long timestamp, boolean alice, boolean active)
+	Map<TransportId, KeySetId> addContactWithRotationKeys(Transaction txn,
+			ContactId c, SecretKey rootKey, long timestamp, boolean alice,
+			boolean active) throws DbException;
+
+	/**
+	 * Informs the key manager that a new contact has been added. Derives and
+	 * stores a set of handshake mode transport keys for communicating with the
+	 * contact over each transport and returns the key set IDs.
+	 * <p/>
+	 * {@link StreamContext StreamContexts} for the contact can be created
+	 * after this method has returned.
+	 *
+	 * @param alice True if the local party is Alice
+	 */
+	Map<TransportId, KeySetId> addContactWithHandshakeKeys(Transaction txn,
+			ContactId c, SecretKey rootKey, boolean alice) throws DbException;
+
+	/**
+	 * Informs the key manager that a new pending contact has been added.
+	 * Derives and stores a set of handshake mode transport keys for
+	 * communicating with the pending contact over each transport and returns
+	 * the key set IDs.
+	 * <p/>
+	 * {@link StreamContext StreamContexts} for the pending contact can be
+	 * created after this method has returned.
+	 *
+	 * @param alice True if the local party is Alice
+	 */
+	Map<TransportId, KeySetId> addPendingContact(Transaction txn,
+			PendingContactId p, SecretKey rootKey, boolean alice)
 			throws DbException;
 
 	/**
@@ -43,15 +72,28 @@ public interface KeyManager {
 	 */
 	boolean canSendOutgoingStreams(ContactId c, TransportId t);
 
+	/**
+	 * Returns true if we have keys that can be used for outgoing streams to
+	 * the given pending contact over the given transport.
+	 */
+	boolean canSendOutgoingStreams(PendingContactId p, TransportId t);
+
 	/**
 	 * Returns a {@link StreamContext} for sending a stream to the given
-	 * contact over the given transport, or null if an error occurs or the
-	 * contact does not support the transport.
+	 * contact over the given transport, or null if an error occurs.
 	 */
 	@Nullable
 	StreamContext getStreamContext(ContactId c, TransportId t)
 			throws DbException;
 
+	/**
+	 * Returns a {@link StreamContext} for sending a stream to the given
+	 * pending contact over the given transport, or null if an error occurs.
+	 */
+	@Nullable
+	StreamContext getStreamContext(PendingContactId p, TransportId t)
+			throws DbException;
+
 	/**
 	 * Looks up the given tag and returns a {@link StreamContext} for reading
 	 * from the corresponding stream, or null if an error occurs or the tag was

bramble-api/src/main/java/org/briarproject/bramble/api/transport/StreamContext.java

@@ -9,6 +9,8 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireExactlyOneNull;
+
 @Immutable
 @NotNullByDefault
 public class StreamContext {
@@ -26,8 +28,7 @@ public class StreamContext {
 			@Nullable PendingContactId pendingContactId,
 			TransportId transportId, SecretKey tagKey, SecretKey headerKey,
 			long streamNumber, boolean handshakeMode) {
-		if ((contactId == null) == (pendingContactId == null))
-			throw new IllegalArgumentException();
+		requireExactlyOneNull(contactId, pendingContactId);
 		this.contactId = contactId;
 		this.pendingContactId = pendingContactId;
 		this.transportId = transportId;

bramble-api/src/main/java/org/briarproject/bramble/api/transport/TransportKeySet.java

@@ -7,6 +7,8 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireExactlyOneNull;
+
 /**
  * A set of keys for communicating with a given contact or pending contact
  * over a given transport.
@@ -24,8 +26,7 @@ public class TransportKeySet {
 
 	public TransportKeySet(KeySetId keySetId, @Nullable ContactId contactId,
 			@Nullable PendingContactId pendingContactId, TransportKeys keys) {
-		if ((contactId == null) == (pendingContactId == null))
-			throw new IllegalArgumentException();
+		requireExactlyOneNull(contactId, pendingContactId);
 		this.keySetId = keySetId;
 		this.contactId = contactId;
 		this.pendingContactId = pendingContactId;

bramble-core/src/main/java/org/briarproject/bramble/contact/ContactManagerImpl.java

@@ -70,7 +70,8 @@ class ContactManagerImpl implements ContactManager {
 			SecretKey rootKey, long timestamp, boolean alice, boolean verified,
 			boolean active) throws DbException {
 		ContactId c = db.addContact(txn, remote, local, verified);
-		keyManager.addContact(txn, c, rootKey, timestamp, alice, active);
+		keyManager.addContactWithRotationKeys(txn, c, rootKey, timestamp,
+				alice, active);
 		Contact contact = db.getContact(txn, c);
 		for (ContactHook hook : hooks) hook.addingContact(txn, contact);
 		return c;

bramble-core/src/main/java/org/briarproject/bramble/transport/KeyManagerImpl.java

 package org.briarproject.bramble.transport;
 
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseComponent;
@@ -28,6 +29,7 @@ import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
@@ -88,14 +90,41 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 	}
 
 	@Override
-	public Map<TransportId, KeySetId> addContact(Transaction txn,
-			ContactId c, SecretKey rootKey, long timestamp, boolean alice,
-			boolean active) throws DbException {
+	public Map<TransportId, KeySetId> addContactWithRotationKeys(
+			Transaction txn, ContactId c, SecretKey rootKey, long timestamp,
+			boolean alice, boolean active) throws DbException {
 		Map<TransportId, KeySetId> ids = new HashMap<>();
 		for (Entry<TransportId, TransportKeyManager> e : managers.entrySet()) {
 			TransportId t = e.getKey();
 			TransportKeyManager m = e.getValue();
-			ids.put(t, m.addContact(txn, c, rootKey, timestamp, alice, active));
+			ids.put(t, m.addContactWithRotationKeys(txn, c, rootKey, timestamp,
+					alice, active));
+		}
+		return ids;
+	}
+
+	@Override
+	public Map<TransportId, KeySetId> addContactWithHandshakeKeys(
+			Transaction txn, ContactId c, SecretKey rootKey, boolean alice)
+			throws DbException {
+		Map<TransportId, KeySetId> ids = new HashMap<>();
+		for (Entry<TransportId, TransportKeyManager> e : managers.entrySet()) {
+			TransportId t = e.getKey();
+			TransportKeyManager m = e.getValue();
+			ids.put(t, m.addContactWithHandshakeKeys(txn, c, rootKey, alice));
+		}
+		return ids;
+	}
+
+	@Override
+	public Map<TransportId, KeySetId> addPendingContact(Transaction txn,
+			PendingContactId p, SecretKey rootKey, boolean alice)
+			throws DbException {
+		Map<TransportId, KeySetId> ids = new HashMap<>();
+		for (Entry<TransportId, TransportKeyManager> e : managers.entrySet()) {
+			TransportId t = e.getKey();
+			TransportKeyManager m = e.getValue();
+			ids.put(t, m.addPendingContact(txn, p, rootKey, alice));
 		}
 		return ids;
 	}
@@ -104,13 +133,10 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 	public void activateKeys(Transaction txn, Map<TransportId, KeySetId> keys)
 			throws DbException {
 		for (Entry<TransportId, KeySetId> e : keys.entrySet()) {
-			TransportId t = e.getKey();
-			TransportKeyManager m = managers.get(t);
-			if (m == null) {
-				if (LOG.isLoggable(INFO)) LOG.info("No key manager for " + t);
-			} else {
+			withManager(e.getKey(), m -> {
 				m.activateKeys(txn, e.getValue());
-			}
+				return null;
+			});
 		}
 	}
 
@@ -120,28 +146,34 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 		return m != null && m.canSendOutgoingStreams(c);
 	}
 
+	@Override
+	public boolean canSendOutgoingStreams(PendingContactId p, TransportId t) {
+		TransportKeyManager m = managers.get(t);
+		return m != null && m.canSendOutgoingStreams(p);
+	}
+
 	@Override
 	public StreamContext getStreamContext(ContactId c, TransportId t)
 			throws DbException {
-		TransportKeyManager m = managers.get(t);
-		if (m == null) {
-			if (LOG.isLoggable(INFO)) LOG.info("No key manager for " + t);
-			return null;
-		}
-		return db.transactionWithNullableResult(false, txn ->
-				m.getStreamContext(txn, c));
+		return withManager(t, m ->
+				db.transactionWithNullableResult(false, txn ->
+						m.getStreamContext(txn, c)));
+	}
+
+	@Override
+	public StreamContext getStreamContext(PendingContactId p, TransportId t)
+			throws DbException {
+		return withManager(t, m ->
+				db.transactionWithNullableResult(false, txn ->
+						m.getStreamContext(txn, p)));
 	}
 
 	@Override
 	public StreamContext getStreamContext(TransportId t, byte[] tag)
 			throws DbException {
-		TransportKeyManager m = managers.get(t);
-		if (m == null) {
-			if (LOG.isLoggable(INFO)) LOG.info("No key manager for " + t);
-			return null;
-		}
-		return db.transactionWithNullableResult(false, txn ->
-				m.getStreamContext(txn, tag));
+		return withManager(t, m ->
+				db.transactionWithNullableResult(false, txn ->
+						m.getStreamContext(txn, tag)));
 	}
 
 	@Override
@@ -156,4 +188,20 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 			for (TransportKeyManager m : managers.values()) m.removeContact(c);
 		});
 	}
+
+	@Nullable
+	private <T> T withManager(TransportId t, ManagerTask<T> task)
+			throws DbException {
+		TransportKeyManager m = managers.get(t);
+		if (m == null) {
+			if (LOG.isLoggable(INFO)) LOG.info("No key manager for " + t);
+			return null;
+		}
+		return task.run(m);
+	}
+
+	private interface ManagerTask<T> {
+		@Nullable
+		T run(TransportKeyManager m) throws DbException;
+	}
 }

bramble-core/src/main/java/org/briarproject/bramble/transport/MutableTransportKeySet.java

@@ -8,6 +8,8 @@ import org.briarproject.bramble.api.transport.KeySetId;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.NotThreadSafe;
 
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireExactlyOneNull;
+
 @NotThreadSafe
 @NotNullByDefault
 class MutableTransportKeySet {
@@ -22,8 +24,7 @@ class MutableTransportKeySet {
 	MutableTransportKeySet(KeySetId keySetId, @Nullable ContactId contactId,
 			@Nullable PendingContactId pendingContactId,
 			MutableTransportKeys keys) {
-		if ((contactId == null) == (pendingContactId == null))
-			throw new IllegalArgumentException();
+		requireExactlyOneNull(contactId, pendingContactId);
 		this.keySetId = keySetId;
 		this.contactId = contactId;
 		this.pendingContactId = pendingContactId;

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManager.java

 package org.briarproject.bramble.transport;
 
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
@@ -15,19 +16,34 @@ interface TransportKeyManager {
 
 	void start(Transaction txn) throws DbException;
 
-	KeySetId addContact(Transaction txn, ContactId c, SecretKey rootKey,
-			long timestamp, boolean alice, boolean active) throws DbException;
+	KeySetId addContactWithRotationKeys(Transaction txn, ContactId c,
+			SecretKey rootKey, long timestamp, boolean alice, boolean active)
+			throws DbException;
+
+	KeySetId addContactWithHandshakeKeys(Transaction txn, ContactId c,
+			SecretKey rootKey, boolean alice) throws DbException;
+
+	KeySetId addPendingContact(Transaction txn, PendingContactId p,
+			SecretKey rootKey, boolean alice) throws DbException;
 
 	void activateKeys(Transaction txn, KeySetId k) throws DbException;
 
 	void removeContact(ContactId c);
 
+	void removePendingContact(PendingContactId p);
+
 	boolean canSendOutgoingStreams(ContactId c);
 
+	boolean canSendOutgoingStreams(PendingContactId p);
+
 	@Nullable
 	StreamContext getStreamContext(Transaction txn, ContactId c)
 			throws DbException;
 
+	@Nullable
+	StreamContext getStreamContext(Transaction txn, PendingContactId p)
+			throws DbException;
+
 	@Nullable
 	StreamContext getStreamContext(Transaction txn, byte[] tag)
 			throws DbException;

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManagerImpl.java

@@ -36,6 +36,7 @@ import javax.annotation.concurrent.ThreadSafe;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireExactlyOneNull;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAX_CLOCK_DIFFERENCE;
 import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
@@ -64,8 +65,11 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	@GuardedBy("lock")
 	private final Map<Bytes, TagContext> inContexts = new HashMap<>();
 	@GuardedBy("lock")
-	private final Map<ContactId, MutableTransportKeySet> outContexts =
-			new HashMap<>();
+	private final Map<ContactId, MutableTransportKeySet>
+			contactOutContexts = new HashMap<>();
+	@GuardedBy("lock")
+	private final Map<PendingContactId, MutableTransportKeySet>
+			pendingContactOutContexts = new HashMap<>();
 
 	TransportKeyManagerImpl(DatabaseComponent db,
 			TransportCrypto transportCrypto, Executor dbExecutor,
@@ -133,6 +137,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	private void addKeys(KeySetId keySetId, @Nullable ContactId contactId,
 			@Nullable PendingContactId pendingContactId,
 			MutableTransportKeys keys) {
+		requireExactlyOneNull(contactId, pendingContactId);
 		MutableTransportKeySet ks = new MutableTransportKeySet(keySetId,
 				contactId, pendingContactId, keys);
 		this.keys.put(keySetId, ks);
@@ -162,19 +167,30 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 
 	@GuardedBy("lock")
 	private void considerReplacingOutgoingKeys(MutableTransportKeySet ks) {
-		// Use the active outgoing keys with the highest key set ID
-		ContactId c = ks.getContactId();
-		if (c != null && ks.getKeys().getCurrentOutgoingKeys().isActive()) {
-			MutableTransportKeySet old = outContexts.get(c);
-			if (old == null ||
-					(old.getKeys().isHandshakeMode() &&
-							!ks.getKeys().isHandshakeMode()) ||
+		// Use the active outgoing keys with the highest key set ID, preferring
+		// rotation keys to handshake keys
+		if (ks.getKeys().getCurrentOutgoingKeys().isActive()) {
+			MutableTransportKeySet old = getOutgoingKeySet(ks.getContactId(),
+					ks.getPendingContactId());
+			if (old == null || (old.getKeys().isHandshakeMode() &&
+					!ks.getKeys().isHandshakeMode()) ||
 					old.getKeySetId().getInt() < ks.getKeySetId().getInt()) {
-				outContexts.put(c, ks);
+				if (ks.getContactId() == null)
+					pendingContactOutContexts.put(ks.getPendingContactId(), ks);
+				else contactOutContexts.put(ks.getContactId(), ks);
 			}
 		}
 	}
 
+	@GuardedBy("lock")
+	@Nullable
+	private MutableTransportKeySet getOutgoingKeySet(@Nullable ContactId c,
+			@Nullable PendingContactId p) {
+		requireExactlyOneNull(c, p);
+		if (c == null) return pendingContactOutContexts.get(p);
+		else return contactOutContexts.get(c);
+	}
+
 	private void scheduleKeyUpdate(long now) {
 		long delay = timePeriodLength - now % timePeriodLength;
 		scheduler.schedule((Runnable) this::updateKeys, delay, MILLISECONDS);
@@ -191,8 +207,9 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	}
 
 	@Override
-	public KeySetId addContact(Transaction txn, ContactId c, SecretKey rootKey,
-			long timestamp, boolean alice, boolean active) throws DbException {
+	public KeySetId addContactWithRotationKeys(Transaction txn, ContactId c,
+			SecretKey rootKey, long timestamp, boolean alice, boolean active)
+			throws DbException {
 		lock.lock();
 		try {
 			// Work out what time period the timestamp belongs to
@@ -213,6 +230,46 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		}
 	}
 
+	@Override
+	public KeySetId addContactWithHandshakeKeys(Transaction txn, ContactId c,
+			SecretKey rootKey, boolean alice) throws DbException {
+		lock.lock();
+		try {
+			// Work out what time period we're in
+			long timePeriod = clock.currentTimeMillis() / timePeriodLength;
+			// Derive the transport keys
+			TransportKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+					rootKey, timePeriod, alice);
+			// Write the keys back to the DB
+			KeySetId keySetId = db.addTransportKeys(txn, c, k);
+			// Initialise mutable state for the contact
+			addKeys(keySetId, c, null, new MutableTransportKeys(k));
+			return keySetId;
+		} finally {
+			lock.unlock();
+		}
+	}
+
+	@Override
+	public KeySetId addPendingContact(Transaction txn, PendingContactId p,
+			SecretKey rootKey, boolean alice) throws DbException {
+		lock.lock();
+		try {
+			// Work out what time period we're in
+			long timePeriod = clock.currentTimeMillis() / timePeriodLength;
+			// Derive the transport keys
+			TransportKeys k = transportCrypto.deriveHandshakeKeys(transportId,
+					rootKey, timePeriod, alice);
+			// Write the keys back to the DB
+			KeySetId keySetId = db.addTransportKeys(txn, p, k);
+			// Initialise mutable state for the pending contact
+			addKeys(keySetId, null, p, new MutableTransportKeys(k));
+			return keySetId;
+		} finally {
+			lock.unlock();
+		}
+	}
+
 	@Override
 	public void activateKeys(Transaction txn, KeySetId k) throws DbException {
 		lock.lock();
@@ -234,8 +291,9 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		try {
 			// Remove mutable state for the contact
 			Iterator<TagContext> it = inContexts.values().iterator();
-			while (it.hasNext()) if (c.equals(it.next().contactId)) it.remove();
-			outContexts.remove(c);
+			while (it.hasNext())
+				if (c.equals(it.next().contactId)) it.remove();
+			contactOutContexts.remove(c);
 			Iterator<MutableTransportKeySet> it1 = keys.values().iterator();
 			while (it1.hasNext())
 				if (c.equals(it1.next().getContactId())) it1.remove();
@@ -244,14 +302,40 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		}
 	}
 
+	@Override
+	public void removePendingContact(PendingContactId p) {
+		lock.lock();
+		try {
+			// Remove mutable state for the pending contact
+			Iterator<TagContext> it = inContexts.values().iterator();
+			while (it.hasNext())
+				if (p.equals(it.next().pendingContactId)) it.remove();
+			pendingContactOutContexts.remove(p);
+			Iterator<MutableTransportKeySet> it1 = keys.values().iterator();
+			while (it1.hasNext())
+				if (p.equals(it1.next().getPendingContactId())) it1.remove();
+		} finally {
+			lock.unlock();
+		}
+	}
+
 	@Override
 	public boolean canSendOutgoingStreams(ContactId c) {
+		return canSendOutgoingStreams(c, null);
+	}
+
+	@Override
+	public boolean canSendOutgoingStreams(PendingContactId p) {
+		return canSendOutgoingStreams(null, p);
+	}
+
+	private boolean canSendOutgoingStreams(@Nullable ContactId c,
+			@Nullable PendingContactId p) {
 		lock.lock();
 		try {
-			MutableTransportKeySet ks = outContexts.get(c);
+			MutableTransportKeySet ks = getOutgoingKeySet(c, p);
 			if (ks == null) return false;
-			MutableOutgoingKeys outKeys =
-					ks.getKeys().getCurrentOutgoingKeys();
+			MutableOutgoingKeys outKeys = ks.getKeys().getCurrentOutgoingKeys();
 			if (!outKeys.isActive()) throw new AssertionError();
 			return outKeys.getStreamCounter() <= MAX_32_BIT_UNSIGNED;
 		} finally {
@@ -262,17 +346,30 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 	@Override
 	public StreamContext getStreamContext(Transaction txn, ContactId c)
 			throws DbException {
+		return getStreamContext(txn, c, null);
+	}
+
+	@Override
+	public StreamContext getStreamContext(Transaction txn, PendingContactId p)
+			throws DbException {
+		return getStreamContext(txn, null, p);
+	}
+
+	@Nullable
+	private StreamContext getStreamContext(Transaction txn,
+			@Nullable ContactId c, @Nullable PendingContactId p)
+			throws DbException {
 		lock.lock();
 		try {
 			// Look up the outgoing keys for the contact
-			MutableTransportKeySet ks = outContexts.get(c);
+			MutableTransportKeySet ks = getOutgoingKeySet(c, p);
 			if (ks == null) return null;
 			MutableTransportKeys keys = ks.getKeys();
 			MutableOutgoingKeys outKeys = keys.getCurrentOutgoingKeys();
 			if (!outKeys.isActive()) throw new AssertionError();
 			if (outKeys.getStreamCounter() > MAX_32_BIT_UNSIGNED) return null;
 			// Create a stream context
-			StreamContext ctx = new StreamContext(c, null, transportId,
+			StreamContext ctx = new StreamContext(c, p, transportId,
 					outKeys.getTagKey(), outKeys.getHeaderKey(),
 					outKeys.getStreamCounter(), keys.isHandshakeMode());
 			// Increment the stream counter and write it back to the DB
@@ -353,7 +450,8 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 			UpdateResult updateResult = updateKeys(snapshot, now);
 			// Rebuild the mutable state for all contacts
 			inContexts.clear();
-			outContexts.clear();
+			contactOutContexts.clear();
+			pendingContactOutContexts.clear();
 			keys.clear();
 			addKeys(updateResult.current);
 			// Write any updated keys back to the DB
@@ -381,6 +479,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 				@Nullable PendingContactId pendingContactId,
 				MutableIncomingKeys inKeys, long streamNumber,
 				boolean handshakeMode) {
+			requireExactlyOneNull(contactId, pendingContactId);
 			this.keySetId = keySetId;
 			this.contactId = contactId;
 			this.pendingContactId = pendingContactId;

bramble-core/src/test/java/org/briarproject/bramble/contact/ContactManagerImplTest.java

@@ -73,8 +73,8 @@ public class ContactManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).transactionWithResult(with(false), withDbCallable(txn));
 			oneOf(db).addContact(txn, remote, local, verified);
 			will(returnValue(contactId));
-			oneOf(keyManager).addContact(txn, contactId, rootKey, timestamp,
-					alice, active);
+			oneOf(keyManager).addContactWithRotationKeys(txn, contactId,
+					rootKey, timestamp, alice, active);