Implement BQP transport descriptors

briar-api/src/org/briarproject/api/keyagreement/KeyAgreementConnection.java

@@ -0,0 +1,23 @@
+package org.briarproject.api.keyagreement;
+
+import org.briarproject.api.TransportId;
+import org.briarproject.api.plugins.duplex.DuplexTransportConnection;
+
+public class KeyAgreementConnection {
+	private final DuplexTransportConnection conn;
+	private final TransportId id;
+
+	public KeyAgreementConnection(DuplexTransportConnection conn,
+			TransportId id) {
+		this.conn = conn;
+		this.id = id;
+	}
+
+	public DuplexTransportConnection getConnection() {
+		return conn;
+	}
+
+	public TransportId getTransportId() {
+		return id;
+	}
+}

briar-api/src/org/briarproject/api/keyagreement/KeyAgreementListener.java

@@ -0,0 +1,35 @@
+package org.briarproject.api.keyagreement;
+
+import java.util.concurrent.Callable;
+
+/**
+ * An class for managing a particular key agreement listener.
+ */
+public abstract class KeyAgreementListener {
+
+	private final TransportDescriptor descriptor;
+
+	public KeyAgreementListener(TransportDescriptor descriptor) {
+		this.descriptor = descriptor;
+	}
+
+	/**
+	 * Returns the descriptor that a remote peer can use to connect to this
+	 * listener.
+	 */
+	public TransportDescriptor getDescriptor() {
+		return descriptor;
+	}
+
+	/**
+	 * Starts listening for incoming connections, and returns a Callable that
+	 * will return a KeyAgreementConnection when an incoming connection is
+	 * received.
+	 */
+	public abstract Callable<KeyAgreementConnection> listen();
+
+	/**
+	 * Closes the underlying server socket.
+	 */
+	public abstract void close();
+}

briar-api/src/org/briarproject/api/keyagreement/TransportDescriptor.java

@@ -0,0 +1,28 @@
+package org.briarproject.api.keyagreement;
+
+import org.briarproject.api.TransportId;
+import org.briarproject.api.properties.TransportProperties;
+
+/**
+ * Describes how to connect to a device over a short-range transport.
+ */
+public class TransportDescriptor {
+
+	private final TransportId id;
+	private final TransportProperties properties;
+
+	public TransportDescriptor(TransportId id, TransportProperties properties) {
+		this.id = id;
+		this.properties = properties;
+	}
+
+	/** Returns the transport identifier. */
+	public TransportId getIdentifier() {
+		return id;
+	}
+
+	/** Returns the transport properties. */
+	public TransportProperties getProperties() {
+		return properties;
+	}
+}

briar-api/src/org/briarproject/api/plugins/PluginManager.java

@@ -19,4 +19,7 @@ public interface PluginManager {
 
 	/** Returns any running duplex plugins that support invitations. */
 	Collection<DuplexPlugin> getInvitationPlugins();
+
+	/** Returns any running duplex plugins that support key agreement. */
+	Collection<DuplexPlugin> getKeyAgreementPlugins();
 }

briar-api/src/org/briarproject/api/plugins/duplex/DuplexPlugin.java

@@ -2,6 +2,8 @@ package org.briarproject.api.plugins.duplex;
 
 import org.briarproject.api.contact.ContactId;
 import org.briarproject.api.crypto.PseudoRandom;
+import org.briarproject.api.keyagreement.KeyAgreementListener;
+import org.briarproject.api.keyagreement.TransportDescriptor;
 import org.briarproject.api.plugins.Plugin;
 
 /** An interface for transport plugins that support duplex communication. */
@@ -24,4 +26,19 @@ public interface DuplexPlugin extends Plugin {
 	 */
 	DuplexTransportConnection createInvitationConnection(PseudoRandom r,
 			long timeout, boolean alice);
+
+	/** Returns true if the plugin supports short-range key agreement. */
+	boolean supportsKeyAgreement();
+
+	/**
+	 * Returns a listener that can be used to perform key agreement.
+	 */
+	KeyAgreementListener createKeyAgreementListener(byte[] localCommitment);
+
+	/**
+	 * Attempts to connect to the remote peer specified in the given descriptor.
+	 * Returns null if no connection can be established within the given time.
+	 */
+	DuplexTransportConnection createKeyAgreementConnection(
+			byte[] remoteCommitment, TransportDescriptor d, long timeout);
 }