Add key manager methods for pending contacts.

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

@@ -17,7 +17,6 @@ public class PendingContactId extends UniqueId {
 		super(id);
 	}
 
-
 	@Override
 	public boolean equals(Object o) {
 		return o instanceof PendingContactId && super.equals(o);

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

@@ -1,6 +1,7 @@
 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;
@@ -39,11 +40,26 @@ public interface KeyManager {
 	 * {@link StreamContext StreamContexts} for the contact can be created
 	 * after this method has returned.
 	 *
-	 * @param alice True if the local party is ALice
+	 * @param alice True if the local party is Alice
 	 */
 	Map<TransportId, KeySetId> addContact(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;
+
 	/**
 	 * Marks the given transport keys as usable for outgoing streams.
 	 */
@@ -56,15 +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