Check whether first visible message ID is null before storing.

.gitlab-ci.yml

@@ -1,4 +1,4 @@
-image: registry.gitlab.com/fdroid/ci-images-base:latest
+image: registry.gitlab.com/fdroid/ci-images:client-latest
 
 cache:
   paths:
@@ -7,7 +7,8 @@ cache:
 
 before_script:
   - export GRADLE_USER_HOME=$PWD/.gradle
-  - echo y | /opt/android-sdk/tools/bin/sdkmanager "build-tools;23.0.3"
+#  - export ANDROID_COMPILE_SDK=`sed -n 's,.*compileSdkVersion\s*\([0-9][0-9]*\).*,\1,p' app/build.gradle`
+#  - echo y | android --silent update sdk --no-ui --filter android-${ANDROID_COMPILE_SDK}
 
 test:
   script:

bramble-android/build.gradle

@@ -12,8 +12,8 @@ android {
 	defaultConfig {
 		minSdkVersion 14
 		targetSdkVersion 22
-		versionCode 1611
-		versionName "0.16.11"
+		versionCode 14
+		versionName "0.14"
 		consumerProguardFiles 'proguard-rules.txt'
 	}
 
@@ -25,38 +25,38 @@ android {
 
 dependencies {
 	compile project(':bramble-core')
-	compile fileTree(dir: 'libs', include: '*.jar')
+	compile fileTree(dir: 'libs', include: ['*.jar'])
 	provided 'javax.annotation:jsr250-api:1.0'
 }
 
 def torBinaryDir = 'src/main/res/raw'
 
 task downloadTorGeoIp(type: Download) {
-	src 'https://briarproject.org/build/geoip-2017-09-06.zip'
+	src 'https://briarproject.org/build/geoip-2015-12-01.zip'
 	dest "$torBinaryDir/geoip.zip"
 	onlyIfNewer true
 }
 
 task downloadTorBinaryArm(type: Download) {
-	src 'https://briarproject.org/build/tor-0.2.9.12-arm.zip'
+	src 'https://briarproject.org/build/tor-0.2.7.6-arm.zip'
 	dest "$torBinaryDir/tor_arm.zip"
 	onlyIfNewer true
 }
 
 task downloadTorBinaryArmPie(type: Download) {
-	src 'https://briarproject.org/build/tor-0.2.9.12-arm-pie.zip'
+	src 'https://briarproject.org/build/tor-0.2.7.6-arm-pie.zip'
 	dest "$torBinaryDir/tor_arm_pie.zip"
 	onlyIfNewer true
 }
 
 task downloadTorBinaryX86(type: Download) {
-	src 'https://briarproject.org/build/tor-0.2.9.12-x86.zip'
+	src 'https://briarproject.org/build/tor-0.2.7.6-x86.zip'
 	dest "$torBinaryDir/tor_x86.zip"
 	onlyIfNewer true
 }
 
 task downloadTorBinaryX86Pie(type: Download) {
-	src 'https://briarproject.org/build/tor-0.2.9.12-x86-pie.zip'
+	src 'https://briarproject.org/build/tor-0.2.7.6-x86-pie.zip'
 	dest "$torBinaryDir/tor_x86_pie.zip"
 	onlyIfNewer true
 }
@@ -64,31 +64,31 @@ task downloadTorBinaryX86Pie(type: Download) {
 task verifyTorGeoIp(type: Verify, dependsOn: 'downloadTorGeoIp') {
 	src "$torBinaryDir/geoip.zip"
 	algorithm 'SHA-256'
-	checksum 'fe49d3adb86d3c512373101422a017dbb86c85a570524663f09dd8ce143a24f3'
+	checksum '9bcdaf0a7ba0933735328d8ec466c25c25dbb459efc2bce9e55c774eabea5162'
 }
 
 task verifyTorBinaryArm(type: Verify, dependsOn: 'downloadTorBinaryArm') {
 	src "$torBinaryDir/tor_arm.zip"
 	algorithm 'SHA-256'
-	checksum '8ed0b347ffed1d6a4d2fd14495118eb92be83e9cc06e057e15220dc288b31688'
+	checksum '83272962eda701cd5d74d2418651c4ff0f0b1dff51f558a292d1a1c42bf12146'
 }
 
 task verifyTorBinaryArmPie(type: Verify, dependsOn: 'downloadTorBinaryArmPie') {
 	src "$torBinaryDir/tor_arm_pie.zip"
 	algorithm 'SHA-256'
-	checksum '64403262511c29f462ca5e7c7621bfc3c944898364d1d5ad35a016bb8a034283'
+	checksum 'd0300d1e45de11ebb24ed62b9c492be9c2e88590b7822195ab38c7a76ffcf646'
 }
 
 task verifyTorBinaryX86(type: Verify, dependsOn: 'downloadTorBinaryX86') {
 	src "$torBinaryDir/tor_x86.zip"
 	algorithm 'SHA-256'
-	checksum '61e014607a2079bcf1646289c67bff6372b1aded6e1d8d83d7791efda9a4d5ab'
+	checksum 'b8813d97b01ee1b9c9a4233c1b9bbe9f9f6b494ae6f9cbd84de8a3911911615e'
 }
 
 task verifyTorBinaryX86Pie(type: Verify, dependsOn: 'downloadTorBinaryX86Pie') {
 	src "$torBinaryDir/tor_x86_pie.zip"
 	algorithm 'SHA-256'
-	checksum '18fbc98356697dd0895836ab46d5c9877d1c539193464f7db1e82a65adaaf288'
+	checksum '9c66e765aa196dc089951a1b2140cc8290305c2fcbf365121f99e01a233baf4e'
 }
 
 project.afterEvaluate {

bramble-android/src/main/java/org/briarproject/bramble/plugin/AndroidPluginModule.java

@@ -39,7 +39,7 @@ public class AndroidPluginModule {
 			EventBus eventBus) {
 		Context appContext = app.getApplicationContext();
 		DuplexPluginFactory bluetooth = new DroidtoothPluginFactory(ioExecutor,
-				androidExecutor, appContext, random, eventBus, backoffFactory);
+				androidExecutor, appContext, random, backoffFactory);
 		DuplexPluginFactory tor = new TorPluginFactory(ioExecutor, appContext,
 				locationUtils, reporter, eventBus, torSocketFactory,
 				backoffFactory);

bramble-android/src/main/java/org/briarproject/bramble/plugin/droidtooth/DroidtoothPlugin.java

@@ -11,9 +11,8 @@ import android.content.IntentFilter;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.data.BdfList;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -24,8 +23,6 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.plugin.event.DisableBluetoothEvent;
-import org.briarproject.bramble.api.plugin.event.EnableBluetoothEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.bramble.util.AndroidUtils;
@@ -33,14 +30,23 @@ import org.briarproject.bramble.util.StringUtils;
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.io.InputStream;
 import java.security.SecureRandom;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.UUID;
 import java.util.concurrent.Callable;
+import java.util.concurrent.CompletionService;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorCompletionService;
+import java.util.concurrent.Future;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
@@ -55,6 +61,8 @@ import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERA
 import static android.bluetooth.BluetoothAdapter.SCAN_MODE_NONE;
 import static android.bluetooth.BluetoothAdapter.STATE_OFF;
 import static android.bluetooth.BluetoothAdapter.STATE_ON;
+import static android.bluetooth.BluetoothDevice.EXTRA_DEVICE;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_BLUETOOTH;
@@ -67,10 +75,14 @@ import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-class DroidtoothPlugin implements DuplexPlugin, EventListener {
+class DroidtoothPlugin implements DuplexPlugin {
 
 	private static final Logger LOG =
 			Logger.getLogger(DroidtoothPlugin.class.getName());
+	private static final String FOUND =
+			"android.bluetooth.device.action.FOUND";
+	private static final String DISCOVERY_FINISHED =
+			"android.bluetooth.adapter.action.DISCOVERY_FINISHED";
 
 	private final Executor ioExecutor;
 	private final AndroidExecutor androidExecutor;
@@ -154,7 +166,9 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		} else {
 			// Enable Bluetooth if settings allow
 			if (callback.getSettings().getBoolean(PREF_BT_ENABLE, false)) {
-				enableAdapter();
+				wasEnabledByUs = true;
+				if (adapter.enable()) LOG.info("Enabling Bluetooth");
+				else LOG.info("Could not enable Bluetooth");
 			} else {
 				LOG.info("Not enabling Bluetooth");
 			}
@@ -245,27 +259,13 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		return new DroidtoothTransportConnection(this, s);
 	}
 
-	private void enableAdapter() {
-		if (adapter != null && !adapter.isEnabled()) {
-			if (adapter.enable()) {
-				LOG.info("Enabling Bluetooth");
-				wasEnabledByUs = true;
-			} else {
-				LOG.info("Could not enable Bluetooth");
-			}
-		}
-	}
-
 	@Override
 	public void stop() {
 		running = false;
 		if (receiver != null) appContext.unregisterReceiver(receiver);
 		tryToClose(socket);
-		disableAdapter();
-	}
-
-	private void disableAdapter() {
-		if (adapter != null && adapter.isEnabled() && wasEnabledByUs) {
+		// Disable Bluetooth if we enabled it and it's still enabled
+		if (wasEnabledByUs && adapter.isEnabled()) {
 			if (adapter.disable()) LOG.info("Disabling Bluetooth");
 			else LOG.info("Could not disable Bluetooth");
 		}
@@ -363,7 +363,8 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 	@Override
 	public DuplexTransportConnection createConnection(ContactId c) {
 		if (!isRunning()) return null;
-		TransportProperties p = callback.getRemoteProperties(c);
+		TransportProperties p = callback.getRemoteProperties().get(c);
+		if (p == null) return null;
 		String address = p.get(PROP_ADDRESS);
 		if (StringUtils.isNullOrEmpty(address)) return null;
 		String uuid = p.get(PROP_UUID);
@@ -373,6 +374,90 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		return new DroidtoothTransportConnection(this, s);
 	}
 
+	@Override
+	public boolean supportsInvitations() {
+		return true;
+	}
+
+	@Override
+	public DuplexTransportConnection createInvitationConnection(PseudoRandom r,
+			long timeout, boolean alice) {
+		if (!isRunning()) return null;
+		// Use the invitation codes to generate the UUID
+		byte[] b = r.nextBytes(UUID_BYTES);
+		UUID uuid = UUID.nameUUIDFromBytes(b);
+		if (LOG.isLoggable(INFO)) LOG.info("Invitation UUID " + uuid);
+		// Bind a server socket for receiving invitation connections
+		BluetoothServerSocket ss;
+		try {
+			ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
+					"RFCOMM", uuid);
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			return null;
+		}
+		// Create the background tasks
+		CompletionService<BluetoothSocket> complete =
+				new ExecutorCompletionService<>(ioExecutor);
+		List<Future<BluetoothSocket>> futures = new ArrayList<>();
+		if (alice) {
+			// Return the first connected socket
+			futures.add(complete.submit(new ListeningTask(ss)));
+			futures.add(complete.submit(new DiscoveryTask(uuid.toString())));
+		} else {
+			// Return the first socket with readable data
+			futures.add(complete.submit(new ReadableTask(
+					new ListeningTask(ss))));
+			futures.add(complete.submit(new ReadableTask(
+					new DiscoveryTask(uuid.toString()))));
+		}
+		BluetoothSocket chosen = null;
+		try {
+			Future<BluetoothSocket> f = complete.poll(timeout, MILLISECONDS);
+			if (f == null) return null; // No task completed within the timeout
+			chosen = f.get();
+			return new DroidtoothTransportConnection(this, chosen);
+		} catch (InterruptedException e) {
+			LOG.info("Interrupted while exchanging invitations");
+			Thread.currentThread().interrupt();
+			return null;
+		} catch (ExecutionException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			return null;
+		} finally {
+			// Closing the socket will terminate the listener task
+			tryToClose(ss);
+			closeSockets(futures, chosen);
+		}
+	}
+
+	private void closeSockets(final List<Future<BluetoothSocket>> futures,
+			@Nullable final BluetoothSocket chosen) {
+		ioExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				for (Future<BluetoothSocket> f : futures) {
+					try {
+						if (f.cancel(true)) {
+							LOG.info("Cancelled task");
+						} else {
+							BluetoothSocket s = f.get();
+							if (s != null && s != chosen) {
+								LOG.info("Closing unwanted socket");
+								s.close();
+							}
+						}
+					} catch (InterruptedException e) {
+						LOG.info("Interrupted while closing sockets");
+						return;
+					} catch (ExecutionException | IOException e) {
+						if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+					}
+				}
+			}
+		});
+	}
+
 	@Override
 	public boolean supportsKeyAgreement() {
 		return true;
@@ -387,7 +472,7 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		// No truncation necessary because COMMIT_LENGTH = 16
 		UUID uuid = UUID.nameUUIDFromBytes(commitment);
 		if (LOG.isLoggable(INFO)) LOG.info("Key agreement UUID " + uuid);
-		// Bind a server socket for receiving key agreement connections
+		// Bind a server socket for receiving invitation connections
 		BluetoothServerSocket ss;
 		try {
 			ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
@@ -428,33 +513,6 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		return StringUtils.macToString(mac);
 	}
 
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof EnableBluetoothEvent) {
-			enableAdapterAsync();
-		} else if (e instanceof DisableBluetoothEvent) {
-			disableAdapterAsync();
-		}
-	}
-
-	private void enableAdapterAsync() {
-		ioExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				enableAdapter();
-			}
-		});
-	}
-
-	private void disableAdapterAsync() {
-		ioExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				disableAdapter();
-			}
-		});
-	}
-
 	private class BluetoothStateReceiver extends BroadcastReceiver {
 
 		@Override
@@ -478,6 +536,115 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		}
 	}
 
+	private class DiscoveryTask implements Callable<BluetoothSocket> {
+
+		private final String uuid;
+
+		private DiscoveryTask(String uuid) {
+			this.uuid = uuid;
+		}
+
+		@Override
+		public BluetoothSocket call() throws Exception {
+			// Repeat discovery until we connect or get interrupted
+			while (true) {
+				// Discover nearby devices
+				LOG.info("Discovering nearby devices");
+				List<String> addresses = discoverDevices();
+				if (addresses.isEmpty()) {
+					LOG.info("No devices discovered");
+					continue;
+				}
+				// Connect to any device with the right UUID
+				for (String address : addresses) {
+					BluetoothSocket s = connect(address, uuid);
+					if (s != null) {
+						LOG.info("Outgoing connection");
+						return s;
+					}
+				}
+			}
+		}
+
+		private List<String> discoverDevices() throws InterruptedException {
+			IntentFilter filter = new IntentFilter();
+			filter.addAction(FOUND);
+			filter.addAction(DISCOVERY_FINISHED);
+			DiscoveryReceiver disco = new DiscoveryReceiver();
+			appContext.registerReceiver(disco, filter);
+			LOG.info("Starting discovery");
+			adapter.startDiscovery();
+			return disco.waitForAddresses();
+		}
+	}
+
+	private static class DiscoveryReceiver extends BroadcastReceiver {
+
+		private final CountDownLatch finished = new CountDownLatch(1);
+		private final List<String> addresses = new CopyOnWriteArrayList<>();
+
+		@Override
+		public void onReceive(Context ctx, Intent intent) {
+			String action = intent.getAction();
+			if (action.equals(DISCOVERY_FINISHED)) {
+				LOG.info("Discovery finished");
+				ctx.unregisterReceiver(this);
+				finished.countDown();
+			} else if (action.equals(FOUND)) {
+				BluetoothDevice d = intent.getParcelableExtra(EXTRA_DEVICE);
+				if (LOG.isLoggable(INFO)) {
+					LOG.info("Discovered device: " +
+							scrubMacAddress(d.getAddress()));
+				}
+				addresses.add(d.getAddress());
+			}
+		}
+
+		private List<String> waitForAddresses() throws InterruptedException {
+			finished.await();
+			List<String> shuffled = new ArrayList<>(addresses);
+			Collections.shuffle(shuffled);
+			return shuffled;
+		}
+	}
+
+	private static class ListeningTask implements Callable<BluetoothSocket> {
+
+		private final BluetoothServerSocket serverSocket;
+
+		private ListeningTask(BluetoothServerSocket serverSocket) {
+			this.serverSocket = serverSocket;
+		}
+
+		@Override
+		public BluetoothSocket call() throws IOException {
+			BluetoothSocket s = serverSocket.accept();
+			LOG.info("Incoming connection");
+			return s;
+		}
+	}
+
+	private static class ReadableTask implements Callable<BluetoothSocket> {
+
+		private final Callable<BluetoothSocket> connectionTask;
+
+		private ReadableTask(Callable<BluetoothSocket> connectionTask) {
+			this.connectionTask = connectionTask;
+		}
+
+		@Override
+		public BluetoothSocket call() throws Exception {
+			BluetoothSocket s = connectionTask.call();
+			InputStream in = s.getInputStream();
+			while (in.available() == 0) {
+				LOG.info("Waiting for data");
+				Thread.sleep(1000);
+			}
+			LOG.info("Data available");
+			return s;
+		}
+	}
+
 	private class BluetoothKeyAgreementListener extends KeyAgreementListener {
 
 		private final BluetoothServerSocket ss;

bramble-android/src/main/java/org/briarproject/bramble/plugin/droidtooth/DroidtoothPluginFactory.java

@@ -2,7 +2,6 @@ package org.briarproject.bramble.plugin.droidtooth;
 
 import android.content.Context;
 
-import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
@@ -32,18 +31,15 @@ public class DroidtoothPluginFactory implements DuplexPluginFactory {
 	private final AndroidExecutor androidExecutor;
 	private final Context appContext;
 	private final SecureRandom secureRandom;
-	private final EventBus eventBus;
 	private final BackoffFactory backoffFactory;
 
 	public DroidtoothPluginFactory(Executor ioExecutor,
 			AndroidExecutor androidExecutor, Context appContext,
-			SecureRandom secureRandom, EventBus eventBus,
-			BackoffFactory backoffFactory) {
+			SecureRandom secureRandom, BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
 		this.androidExecutor = androidExecutor;
 		this.appContext = appContext;
 		this.secureRandom = secureRandom;
-		this.eventBus = eventBus;
 		this.backoffFactory = backoffFactory;
 	}
 
@@ -61,10 +57,7 @@ public class DroidtoothPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(DuplexPluginCallback callback) {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		DroidtoothPlugin plugin = new DroidtoothPlugin(ioExecutor,
-				androidExecutor, appContext, secureRandom, backoff, callback,
-				MAX_LATENCY);
-		eventBus.addListener(plugin);
-		return plugin;
+		return new DroidtoothPlugin(ioExecutor, androidExecutor, appContext,
+				secureRandom, backoff, callback, MAX_LATENCY);
 	}
 }

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorPlugin.java

@@ -17,6 +17,7 @@ import net.freehaven.tor.control.EventHandler;
 import net.freehaven.tor.control.TorControlConnection;
 
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
@@ -55,7 +56,6 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Scanner;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
@@ -85,13 +85,13 @@ import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_NEVER;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_WIFI;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_PORT;
-import static org.briarproject.bramble.api.plugin.TorConstants.PROP_ONION;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubOnion;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
+	private static final String PROP_ONION = "onion";
 	private static final String[] EVENTS = {
 			"CIRC", "ORCONN", "HS_DESC", "NOTICE", "WARN", "ERR"
 	};
@@ -539,21 +539,16 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	public void poll(Collection<ContactId> connected) {
 		if (!isRunning()) return;
 		backoff.increment();
-		Map<ContactId, TransportProperties> remote =
-				callback.getRemoteProperties();
-		for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {
-			ContactId c = e.getKey();
-			if (!connected.contains(c)) connectAndCallBack(c, e.getValue());
-		}
+		// TODO: Pass properties to connectAndCallBack()
+		for (ContactId c : callback.getRemoteProperties().keySet())
+			if (!connected.contains(c)) connectAndCallBack(c);
 	}
 
-	private void connectAndCallBack(final ContactId c,
-			final TransportProperties p) {
+	private void connectAndCallBack(final ContactId c) {
 		ioExecutor.execute(new Runnable() {
 			@Override
 			public void run() {
-				if (!isRunning()) return;
-				DuplexTransportConnection d = createConnection(p);
+				DuplexTransportConnection d = createConnection(c);
 				if (d != null) {
 					backoff.reset();
 					callback.outgoingConnectionCreated(c, d);
@@ -565,11 +560,8 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public DuplexTransportConnection createConnection(ContactId c) {
 		if (!isRunning()) return null;
-		return createConnection(callback.getRemoteProperties(c));
-	}
-
-	@Nullable
-	private DuplexTransportConnection createConnection(TransportProperties p) {
+		TransportProperties p = callback.getRemoteProperties().get(c);
+		if (p == null) return null;
 		String onion = p.get(PROP_ONION);
 		if (StringUtils.isNullOrEmpty(onion)) return null;
 		if (!ONION.matcher(onion).matches()) {
@@ -597,6 +589,17 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		}
 	}
 
+	@Override
+	public boolean supportsInvitations() {
+		return false;
+	}
+
+	@Override
+	public DuplexTransportConnection createInvitationConnection(PseudoRandom r,
+			long timeout, boolean alice) {
+		throw new UnsupportedOperationException();
+	}
+
 	@Override
 	public boolean supportsKeyAgreement() {
 		return false;

bramble-android/src/main/java/org/briarproject/bramble/plugin/tor/TorTransportConnection.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.plugin.tor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.duplex.AbstractDuplexTransportConnection;
-import org.briarproject.bramble.util.IoUtils;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -22,12 +21,12 @@ class TorTransportConnection extends AbstractDuplexTransportConnection {
 
 	@Override
 	protected InputStream getInputStream() throws IOException {
-		return IoUtils.getInputStream(socket);
+		return socket.getInputStream();
 	}
 
 	@Override
 	protected OutputStream getOutputStream() throws IOException {
-		return IoUtils.getOutputStream(socket);
+		return socket.getOutputStream();
 	}
 
 	@Override

bramble-api/build.gradle

@@ -7,12 +7,12 @@ apply plugin: 'witness'
 dependencies {
 	compile "com.google.dagger:dagger:2.0.2"
 	compile 'com.google.dagger:dagger-compiler:2.0.2'
-	compile 'com.google.code.findbugs:jsr305:3.0.2'
+	compile 'com.google.code.findbugs:jsr305:3.0.1'
 
 	testCompile 'junit:junit:4.12'
-	testCompile "org.jmock:jmock:2.8.2"
-	testCompile "org.jmock:jmock-junit4:2.8.2"
-	testCompile "org.jmock:jmock-legacy:2.8.2"
+	testCompile "org.jmock:jmock:2.8.1"
+	testCompile "org.jmock:jmock-junit4:2.8.1"
+	testCompile "org.jmock:jmock-legacy:2.8.1"
 	testCompile "org.hamcrest:hamcrest-library:1.3"
 	testCompile "org.hamcrest:hamcrest-core:1.3"
 }
@@ -21,7 +21,7 @@ dependencyVerification {
 	verify = [
 			'com.google.dagger:dagger:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
 			'com.google.dagger:dagger-compiler:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
-			'com.google.code.findbugs:jsr305:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+			'com.google.code.findbugs:jsr305:c885ce34249682bc0236b4a7d56efcc12048e6135a5baf7a9cde8ad8cda13fcd',
 			'javax.inject:javax.inject:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
 			'com.google.dagger:dagger-producers:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
 			'com.google.guava:guava:d664fbfc03d2e5ce9cab2a44fb01f1d0bf9dfebeccc1a473b1f9ea31f79f6f99',

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/CryptoComponent.java

@@ -10,6 +10,8 @@ public interface CryptoComponent {
 
 	SecretKey generateSecretKey();
 
+	PseudoRandom getPseudoRandom(int seed1, int seed2);
+
 	SecureRandom getSecureRandom();
 
 	KeyPair generateAgreementKeyPair();
@@ -22,6 +24,15 @@ public interface CryptoComponent {
 
 	KeyParser getMessageKeyParser();
 
+	/** Generates a random invitation code. */
+	int generateBTInvitationCode();
+
+	/**
+	 * Derives a confirmation code from the given master secret.
+	 * @param alice whether the code is for use by Alice or Bob.
+	 */
+	int deriveBTConfirmationCode(SecretKey master, boolean alice);
+
 	/**
 	 * Derives a stream header key from the given master secret.
 	 * @param alice whether the key is for use by Alice or Bob.
@@ -126,8 +137,7 @@ public interface CryptoComponent {
 	TransportKeys rotateTransportKeys(TransportKeys k, long rotationPeriod);
 
 	/** Encodes the pseudo-random tag that is used to recognise a stream. */
-	void encodeTag(byte[] tag, SecretKey tagKey, int protocolVersion,
-			long streamNumber);
+	void encodeTag(byte[] tag, SecretKey tagKey, long streamNumber);
 
 	/**
 	 * Signs the given byte[] with the given PrivateKey.

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/PseudoRandom.java

@@ -0,0 +1,12 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+/**
+ * A deterministic pseudo-random number generator.
+ */
+@NotNullByDefault
+public interface PseudoRandom {
+
+	byte[] nextBytes(int bytes);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/StreamDecrypterFactory.java

@@ -14,9 +14,8 @@ public interface StreamDecrypterFactory {
 	StreamDecrypter createStreamDecrypter(InputStream in, StreamContext ctx);
 
 	/**
-	 * Creates a {@link StreamDecrypter} for decrypting a contact exchange
-	 * stream.
+	 * Creates a {@link StreamDecrypter} for decrypting an invitation stream.
 	 */
-	StreamDecrypter createContactExchangeStreamDecrypter(InputStream in,
+	StreamDecrypter createInvitationStreamDecrypter(InputStream in,
 			SecretKey headerKey);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/crypto/StreamEncrypterFactory.java

@@ -14,9 +14,8 @@ public interface StreamEncrypterFactory {
 	StreamEncrypter createStreamEncrypter(OutputStream out, StreamContext ctx);
 
 	/**
-	 * Creates a {@link StreamEncrypter} for encrypting a contact exchange
-	 * stream.
+	 * Creates a {@link StreamEncrypter} for encrypting an invitation stream.
 	 */
-	StreamEncrypter createContactExchangeStreamDecrypter(OutputStream out,
+	StreamEncrypter createInvitationStreamEncrypter(OutputStream out,
 			SecretKey headerKey);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/invitation/InvitationConstants.java

@@ -0,0 +1,20 @@
+package org.briarproject.bramble.api.invitation;
+
+public interface InvitationConstants {
+
+	/**
+	 * The connection timeout in milliseconds.
+	 */
+	long CONNECTION_TIMEOUT = 60 * 1000;
+
+	/**
+	 * The confirmation timeout in milliseconds.
+	 */
+	long CONFIRMATION_TIMEOUT = 60 * 1000;
+
+	/**
+	 * The number of bits in an invitation or confirmation code. Codes must fit
+	 * into six decimal digits.
+	 */
+	int CODE_BITS = 19;
+}

bramble-api/src/main/java/org/briarproject/bramble/api/invitation/InvitationListener.java

@@ -0,0 +1,47 @@
+package org.briarproject.bramble.api.invitation;
+
+/**
+ * An interface for receiving updates about the state of an
+ * {@link InvitationTask}.
+ */
+public interface InvitationListener {
+
+	/** Called if a connection to the remote peer is established. */
+	void connectionSucceeded();
+
+	/**
+	 * Called if a connection to the remote peer cannot be established. This
+	 * indicates that the protocol has ended unsuccessfully.
+	 */
+	void connectionFailed();
+
+	/** Called if key agreement with the remote peer succeeds. */
+	void keyAgreementSucceeded(int localCode, int remoteCode);
+
+	/**
+	 * Called if key agreement with the remote peer fails or the connection is
+	 * lost. This indicates that the protocol has ended unsuccessfully.
+	 */
+	void keyAgreementFailed();
+
+	/** Called if the remote peer's confirmation check succeeds. */
+	void remoteConfirmationSucceeded();
+
+	/**
+	 * Called if remote peer's confirmation check fails or the connection is
+	 * lost. This indicates that the protocol has ended unsuccessfully.
+	 */
+	void remoteConfirmationFailed();
+
+	/**
+	 * Called if the exchange of pseudonyms succeeds. This indicates that the
+	 * protocol has ended successfully.
+	 */
+	void pseudonymExchangeSucceeded(String remoteName);
+
+	/**
+	 * Called if the exchange of pseudonyms fails or the connection is lost.
+	 * This indicates that the protocol has ended unsuccessfully.
+	 */
+	void pseudonymExchangeFailed();
+}

bramble-api/src/main/java/org/briarproject/bramble/api/invitation/InvitationState.java

@@ -0,0 +1,85 @@
+package org.briarproject.bramble.api.invitation;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * A snapshot of the state of an {@link InvitationTask}.
+ */
+@Immutable
+@NotNullByDefault
+public class InvitationState {
+
+	private final int localInvitationCode, remoteInvitationCode;
+	private final int localConfirmationCode, remoteConfirmationCode;
+	private final boolean connected, connectionFailed;
+	private final boolean localCompared, remoteCompared;
+	private final boolean localMatched, remoteMatched;
+	@Nullable
+	private final String contactName;
+
+	public InvitationState(int localInvitationCode, int remoteInvitationCode,
+			int localConfirmationCode, int remoteConfirmationCode,
+			boolean connected, boolean connectionFailed, boolean localCompared,
+			boolean remoteCompared, boolean localMatched,
+			boolean remoteMatched, @Nullable String contactName) {
+		this.localInvitationCode = localInvitationCode;
+		this.remoteInvitationCode = remoteInvitationCode;
+		this.localConfirmationCode = localConfirmationCode;
+		this.remoteConfirmationCode = remoteConfirmationCode;
+		this.connected = connected;
+		this.connectionFailed = connectionFailed;
+		this.localCompared = localCompared;
+		this.remoteCompared = remoteCompared;
+		this.localMatched = localMatched;
+		this.remoteMatched = remoteMatched;
+		this.contactName = contactName;
+	}
+
+	public int getLocalInvitationCode() {
+		return localInvitationCode;
+	}
+
+	public int getRemoteInvitationCode() {
+		return remoteInvitationCode;
+	}
+
+	public int getLocalConfirmationCode() {
+		return localConfirmationCode;
+	}
+
+	public int getRemoteConfirmationCode() {
+		return remoteConfirmationCode;
+	}
+
+	public boolean getConnected() {
+		return connected;
+	}
+
+	public boolean getConnectionFailed() {
+		return connectionFailed;
+	}
+
+	public boolean getLocalCompared() {
+		return localCompared;
+	}
+
+	public boolean getRemoteCompared() {
+		return remoteCompared;
+	}
+
+	public boolean getLocalMatched() {
+		return localMatched;
+	}
+
+	public boolean getRemoteMatched() {
+		return remoteMatched;
+	}
+
+	@Nullable
+	public String getContactName() {
+		return contactName;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/invitation/InvitationTask.java

@@ -0,0 +1,38 @@
+package org.briarproject.bramble.api.invitation;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+/**
+ * A task for exchanging invitations with a remote peer.
+ */
+@NotNullByDefault
+public interface InvitationTask {
+
+	/**
+	 * Adds a listener to be informed of state changes and returns the
+	 * task's current state.
+	 */
+	InvitationState addListener(InvitationListener l);
+
+	/**
+	 * Removes the given listener.
+	 */
+	void removeListener(InvitationListener l);
+
+	/**
+	 * Asynchronously starts the connection process.
+	 */
+	void connect();
+
+	/**
+	 * Asynchronously informs the remote peer that the local peer's
+	 * confirmation codes matched.
+	 */
+	void localConfirmationSucceeded();
+
+	/**
+	 * Asynchronously informs the remote peer that the local peer's
+	 * confirmation codes did not match.
+	 */
+	void localConfirmationFailed();
+}

bramble-api/src/main/java/org/briarproject/bramble/api/invitation/InvitationTaskFactory.java

@@ -0,0 +1,15 @@
+package org.briarproject.bramble.api.invitation;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+/**
+ * Creates tasks for exchanging invitations with remote peers.
+ */
+@NotNullByDefault
+public interface InvitationTaskFactory {
+
+	/**
+	 * Creates a task using the given local and remote invitation codes.
+	 */
+	InvitationTask createTask(int localCode, int remoteCode);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/LanTcpConstants.java

@@ -4,10 +4,5 @@ public interface LanTcpConstants {
 
 	TransportId ID = new TransportId("org.briarproject.bramble.lan");
 
-	// a transport property (shared with contacts)
-	String PROP_IP_PORTS = "ipPorts";
-
-	// a local setting
 	String PREF_LAN_IP_PORTS = "ipPorts";
-
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginCallback.java

@@ -29,11 +29,6 @@ public interface PluginCallback {
 	 */
 	Map<ContactId, TransportProperties> getRemoteProperties();
 
-	/**
-	 * Returns the plugin's remote transport properties for the given contact.
-	 */
-	TransportProperties getRemoteProperties(ContactId c);
-
 	/**
 	 * Merges the given settings with the namespaced settings
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginManager.java

@@ -32,6 +32,11 @@ public interface PluginManager {
 	 */
 	Collection<DuplexPlugin> getDuplexPlugins();
 
+	/**
+	 * Returns any duplex plugins that support invitations.
+	 */
+	Collection<DuplexPlugin> getInvitationPlugins();
+
 	/**
 	 * Returns any duplex plugins that support key agreement.
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/TorConstants.java

@@ -4,8 +4,6 @@ public interface TorConstants {
 
 	TransportId ID = new TransportId("org.briarproject.bramble.tor");
 
-	String PROP_ONION = "onion";
-
 	int SOCKS_PORT = 59050;
 	int CONTROL_PORT = 59051;
 
@@ -18,5 +16,4 @@ public interface TorConstants {
 	int PREF_TOR_NETWORK_NEVER = 0;
 	int PREF_TOR_NETWORK_WIFI = 1;
 	int PREF_TOR_NETWORK_ALWAYS = 2;
-
 }

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/duplex/DuplexPlugin.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.api.plugin.duplex;
 
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -22,6 +23,20 @@ public interface DuplexPlugin extends Plugin {
 	@Nullable
 	DuplexTransportConnection createConnection(ContactId c);
 
+	/**
+	 * Returns true if the plugin supports exchanging invitations.
+	 */
+	boolean supportsInvitations();
+
+	/**
+	 * Attempts to create and return an invitation connection to the remote
+	 * peer. Returns null if no connection can be established within the given
+	 * time.
+	 */
+	@Nullable
+	DuplexTransportConnection createInvitationConnection(PseudoRandom r,
+			long timeout, boolean alice);
+
 	/**
 	 * Returns true if the plugin supports short-range key agreement.
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/DisableBluetoothEvent.java

@@ -1,15 +0,0 @@
-package org.briarproject.bramble.api.plugin.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that asks the Bluetooth plugin to disable the Bluetooth adapter if
- * we previously enabled it.
- */
-@Immutable
-@NotNullByDefault
-public class DisableBluetoothEvent extends Event {
-}

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/event/EnableBluetoothEvent.java

@@ -1,14 +0,0 @@
-package org.briarproject.bramble.api.plugin.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event asks the Bluetooth plugin to enable the Bluetooth adapter.
- */
-@Immutable
-@NotNullByDefault
-public class EnableBluetoothEvent extends Event {
-}

bramble-api/src/main/java/org/briarproject/bramble/api/properties/TransportPropertyManager.java

@@ -49,13 +49,6 @@ public interface TransportPropertyManager {
 	Map<ContactId, TransportProperties> getRemoteProperties(TransportId t)
 			throws DbException;
 
-	/**
-	 * Returns the remote transport properties for the given contact and
-	 * transport.
-	 */
-	TransportProperties getRemoteProperties(ContactId c, TransportId t)
-			throws DbException;
-
 	/**
 	 * Merges the given properties with the existing local properties for the
 	 * given transport.

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

@@ -15,9 +15,9 @@ public interface StreamReaderFactory {
 	InputStream createStreamReader(InputStream in, StreamContext ctx);
 
 	/**
-	 * Creates an {@link InputStream InputStream} for reading from a contact
-	 * exchangestream.
+	 * Creates an {@link InputStream InputStream} for reading from an
+	 * invitation stream.
 	 */
-	InputStream createContactExchangeStreamReader(InputStream in,
+	InputStream createInvitationStreamReader(InputStream in,
 			SecretKey headerKey);
 }

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

@@ -15,9 +15,9 @@ public interface StreamWriterFactory {
 	OutputStream createStreamWriter(OutputStream out, StreamContext ctx);
 
 	/**
-	 * Creates an {@link OutputStream OutputStream} for writing to a contact
-	 * exchange stream.
+	 * Creates an {@link OutputStream OutputStream} for writing to an
+	 * invitation stream.
 	 */
-	OutputStream createContactExchangeStreamWriter(OutputStream out,
+	OutputStream createInvitationStreamWriter(OutputStream out,
 			SecretKey headerKey);
 }

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

@@ -4,11 +4,6 @@ import org.briarproject.bramble.api.crypto.SecretKey;
 
 public interface TransportConstants {
 
-	/**
-	 * The current version of the transport protocol.
-	 */
-	int PROTOCOL_VERSION = 3;
-
 	/**
 	 * The length of the pseudo-random tag in bytes.
 	 */
@@ -19,22 +14,21 @@ public interface TransportConstants {
 	 */
 	int STREAM_HEADER_NONCE_LENGTH = 24;
 
+	/**
+	 * The length of the stream header initialisation vector (IV) in bytes.
+	 */
+	int STREAM_HEADER_IV_LENGTH = STREAM_HEADER_NONCE_LENGTH - 8;
+
 	/**
 	 * The length of the message authentication code (MAC) in bytes.
 	 */
 	int MAC_LENGTH = 16;
 
-	/**
-	 * The length of the stream header plaintext in bytes. The stream header
-	 * contains the protocol version, stream number and frame key.
-	 */
-	int STREAM_HEADER_PLAINTEXT_LENGTH = 2 + 8 + SecretKey.LENGTH;
-
 	/**
 	 * The length of the stream header in bytes.
 	 */
-	int STREAM_HEADER_LENGTH = STREAM_HEADER_NONCE_LENGTH
-			+ STREAM_HEADER_PLAINTEXT_LENGTH + MAC_LENGTH;
+	int STREAM_HEADER_LENGTH = STREAM_HEADER_IV_LENGTH + SecretKey.LENGTH
+			+ MAC_LENGTH;
 
 	/**
 	 * The length of the frame nonce in bytes.

bramble-api/src/main/java/org/briarproject/bramble/util/IoUtils.java

@@ -8,7 +8,6 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.net.Socket;
 
 import javax.annotation.Nullable;
 
@@ -60,24 +59,4 @@ public class IoUtils {
 			offset += read;
 		}
 	}
-
-	// Workaround for a bug in Android 7, see
-	// https://android-review.googlesource.com/#/c/271775/
-	public static InputStream getInputStream(Socket s) throws IOException {
-		try {
-			return s.getInputStream();
-		} catch (NullPointerException e) {
-			throw new IOException(e);
-		}
-	}
-
-	// Workaround for a bug in Android 7, see
-	// https://android-review.googlesource.com/#/c/271775/
-	public static OutputStream getOutputStream(Socket s) throws IOException {
-		try {
-			return s.getOutputStream();
-		} catch (NullPointerException e) {
-			throw new IOException(e);
-		}
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/util/StringUtils.java

@@ -8,7 +8,6 @@ import java.nio.charset.CharacterCodingException;
 import java.nio.charset.Charset;
 import java.nio.charset.CharsetDecoder;
 import java.util.Collection;
-import java.util.Random;
 import java.util.regex.Pattern;
 
 import javax.annotation.Nullable;
@@ -28,7 +27,6 @@ public class StringUtils {
 			'0', '1', '2', '3', '4', '5', '6', '7',
 			'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
 	};
-	private static final Random random = new Random();
 
 	public static boolean isNullOrEmpty(@Nullable String s) {
 		return s == null || s.length() == 0;
@@ -141,12 +139,4 @@ public class StringUtils {
 		}
 		return s.toString();
 	}
-
-	public static String getRandomString(int length) {
-		char[] c = new char[length];
-		for (int i = 0; i < length; i++)
-			c[i] = (char) ('a' + random.nextInt(26));
-		return new String(c);
-	}
-
 }

bramble-api/src/test/java/org/briarproject/bramble/test/TestUtils.java

@@ -34,6 +34,13 @@ public class TestUtils {
 		return getRandomBytes(UniqueId.LENGTH);
 	}
 
+	public static String getRandomString(int length) {
+		char[] c = new char[length];
+		for (int i = 0; i < length; i++)
+			c[i] = (char) ('a' + random.nextInt(26));
+		return new String(c);
+	}
+
 	public static SecretKey getSecretKey() {
 		return new SecretKey(getRandomBytes(SecretKey.LENGTH));
 	}

bramble-core/build.gradle

@@ -1,9 +1,8 @@
 plugins {
-	id 'java'
-	id 'net.ltgt.apt' version '0.9'
-	id 'idea'
+	id "java"
+	id "net.ltgt.apt" version "0.9"
+	id "idea"
 }
-
 sourceCompatibility = 1.6
 targetCompatibility = 1.6
 
@@ -11,18 +10,17 @@ apply plugin: 'witness'
 
 dependencies {
 	compile project(':bramble-api')
-	compile 'com.madgag.spongycastle:core:1.58.0.0'
-	compile 'com.h2database:h2:1.4.192' // This is the last version that supports Java 1.6
-	compile 'org.bitlet:weupnp:0.1.4'
+	compile fileTree(dir: 'libs', include: '*.jar')
+	compile 'com.madgag.spongycastle:core:1.54.0.0'
+	compile 'com.h2database:h2:1.4.190'
 
 	testCompile project(path: ':bramble-api', configuration: 'testOutput')
 }
 
 dependencyVerification {
 	verify = [
-			'com.madgag.spongycastle:core:199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728',
-			'com.h2database:h2:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
-			'org.bitlet:weupnp:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
+			'com.madgag.spongycastle:core:1e7fa4b19ccccd1011364ab838d0b4702470c178bbbdd94c5c90b2d4d749ea1e',
+			'com.h2database:h2:23ba495a07bbbb3bd6c3084d10a96dad7a23741b8b6d64b213459a784195a98c'
 	]
 }
 

bramble-core/src/main/java/org/briarproject/bramble/BrambleCoreModule.java

@@ -8,6 +8,7 @@ import org.briarproject.bramble.db.DatabaseExecutorModule;
 import org.briarproject.bramble.db.DatabaseModule;
 import org.briarproject.bramble.event.EventModule;
 import org.briarproject.bramble.identity.IdentityModule;
+import org.briarproject.bramble.invitation.InvitationModule;
 import org.briarproject.bramble.keyagreement.KeyAgreementModule;
 import org.briarproject.bramble.lifecycle.LifecycleModule;
 import org.briarproject.bramble.plugin.PluginModule;
@@ -31,6 +32,7 @@ import dagger.Module;
 		DatabaseExecutorModule.class,
 		EventModule.class,
 		IdentityModule.class,
+		InvitationModule.class,
 		KeyAgreementModule.class,
 		LifecycleModule.class,
 		PluginModule.class,
@@ -52,7 +54,6 @@ public class BrambleCoreModule {
 		c.inject(new IdentityModule.EagerSingletons());
 		c.inject(new LifecycleModule.EagerSingletons());
 		c.inject(new PluginModule.EagerSingletons());
-		c.inject(new PropertiesModule.EagerSingletons());
 		c.inject(new SyncModule.EagerSingletons());
 		c.inject(new SystemModule.EagerSingletons());
 		c.inject(new TransportModule.EagerSingletons());

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

@@ -80,7 +80,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 	private volatile boolean alice;
 
 	@Inject
-	ContactExchangeTaskImpl(DatabaseComponent db,
+	public ContactExchangeTaskImpl(DatabaseComponent db,
 			AuthorFactory authorFactory, BdfReaderFactory bdfReaderFactory,
 			BdfWriterFactory bdfWriterFactory, Clock clock,
 			ConnectionManager connectionManager, ContactManager contactManager,
@@ -146,12 +146,12 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 
 		// Create the readers
 		InputStream streamReader =
-				streamReaderFactory.createContactExchangeStreamReader(in,
+				streamReaderFactory.createInvitationStreamReader(in,
 						alice ? bobHeaderKey : aliceHeaderKey);
 		BdfReader r = bdfReaderFactory.createReader(streamReader);
 		// Create the writers
 		OutputStream streamWriter =
-				streamWriterFactory.createContactExchangeStreamWriter(out,
+				streamWriterFactory.createInvitationStreamWriter(out,
 						alice ? aliceHeaderKey : bobHeaderKey);
 		BdfWriter w = bdfWriterFactory.createWriter(streamWriter);
 

bramble-core/src/main/java/org/briarproject/bramble/crypto/CryptoComponentImpl.java

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.KeyParser;
 import org.briarproject.bramble.api.crypto.PrivateKey;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.plugin.TransportId;
@@ -40,13 +41,12 @@ import java.util.logging.Logger;
 import javax.inject.Inject;
 
 import static java.util.logging.Level.INFO;
+import static org.briarproject.bramble.api.invitation.InvitationConstants.CODE_BITS;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.COMMIT_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
 import static org.briarproject.bramble.crypto.EllipticCurveConstants.PARAMETERS;
-import static org.briarproject.bramble.util.ByteUtils.INT_16_BYTES;
 import static org.briarproject.bramble.util.ByteUtils.INT_32_BYTES;
 import static org.briarproject.bramble.util.ByteUtils.INT_64_BYTES;
-import static org.briarproject.bramble.util.ByteUtils.MAX_16_BIT_UNSIGNED;
 import static org.briarproject.bramble.util.ByteUtils.MAX_32_BIT_UNSIGNED;
 
 class CryptoComponentImpl implements CryptoComponent {
@@ -66,6 +66,9 @@ class CryptoComponentImpl implements CryptoComponent {
 		return s.getBytes(Charset.forName("US-ASCII"));
 	}
 
+	// KDF labels for bluetooth confirmation code derivation
+	private static final byte[] BT_A_CONFIRM = ascii("ALICE_CONFIRMATION_CODE");
+	private static final byte[] BT_B_CONFIRM = ascii("BOB_CONFIRMATION_CODE");
 	// KDF labels for contact exchange stream header key derivation
 	private static final byte[] A_INVITE = ascii("ALICE_INVITATION_KEY");
 	private static final byte[] B_INVITE = ascii("BOB_INVITATION_KEY");
@@ -166,6 +169,14 @@ class CryptoComponentImpl implements CryptoComponent {
 		return new SecretKey(b);
 	}
 
+	@Override
+	public PseudoRandom getPseudoRandom(int seed1, int seed2) {
+		byte[] seed = new byte[INT_32_BYTES * 2];
+		ByteUtils.writeUint32(seed1, seed, 0);
+		ByteUtils.writeUint32(seed2, seed, INT_32_BYTES);
+		return new PseudoRandomImpl(seed);
+	}
+
 	@Override
 	public SecureRandom getSecureRandom() {
 		return secureRandom;
@@ -237,6 +248,20 @@ class CryptoComponentImpl implements CryptoComponent {
 		return messageEncrypter.getKeyParser();
 	}
 
+	@Override
+	public int generateBTInvitationCode() {
+		int codeBytes = (CODE_BITS + 7) / 8;
+		byte[] random = new byte[codeBytes];
+		secureRandom.nextBytes(random);
+		return ByteUtils.readUint(random, CODE_BITS);
+	}
+
+	@Override
+	public int deriveBTConfirmationCode(SecretKey master, boolean alice) {
+		byte[] b = macKdf(master, alice ? BT_A_CONFIRM : BT_B_CONFIRM);
+		return ByteUtils.readUint(b, CODE_BITS);
+	}
+
 	@Override
 	public SecretKey deriveHeaderKey(SecretKey master,
 			boolean alice) {
@@ -387,11 +412,8 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public void encodeTag(byte[] tag, SecretKey tagKey, int protocolVersion,
-			long streamNumber) {
+	public void encodeTag(byte[] tag, SecretKey tagKey, long streamNumber) {
 		if (tag.length < TAG_LENGTH) throw new IllegalArgumentException();
-		if (protocolVersion < 0 || protocolVersion > MAX_16_BIT_UNSIGNED)
-			throw new IllegalArgumentException();
 		if (streamNumber < 0 || streamNumber > MAX_32_BIT_UNSIGNED)
 			throw new IllegalArgumentException();
 		// Initialise the PRF
@@ -399,14 +421,10 @@ class CryptoComponentImpl implements CryptoComponent {
 		// The output of the PRF must be long enough to use as a tag
 		int macLength = prf.getDigestSize();
 		if (macLength < TAG_LENGTH) throw new IllegalStateException();
-		// The input is the protocol version as a 16-bit integer, followed by
-		// the stream number as a 64-bit integer
-		byte[] protocolVersionBytes = new byte[INT_16_BYTES];
-		ByteUtils.writeUint16(protocolVersion, protocolVersionBytes, 0);
-		prf.update(protocolVersionBytes, 0, protocolVersionBytes.length);
-		byte[] streamNumberBytes = new byte[INT_64_BYTES];
-		ByteUtils.writeUint64(streamNumber, streamNumberBytes, 0);
-		prf.update(streamNumberBytes, 0, streamNumberBytes.length);
+		// The input is the stream number as a 64-bit integer
+		byte[] input = new byte[INT_64_BYTES];
+		ByteUtils.writeUint64(streamNumber, input, 0);
+		prf.update(input, 0, input.length);
 		byte[] mac = new byte[macLength];
 		prf.doFinal(mac, 0);
 		// The output is the first TAG_LENGTH bytes of the MAC

bramble-core/src/main/java/org/briarproject/bramble/crypto/PseudoRandomImpl.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.spongycastle.crypto.Digest;
 import org.spongycastle.crypto.engines.Salsa20Engine;
@@ -10,11 +11,11 @@ import javax.annotation.concurrent.NotThreadSafe;
 
 @NotThreadSafe
 @NotNullByDefault
-class PseudoRandom {
+class PseudoRandomImpl implements PseudoRandom {
 
 	private final Salsa20Engine cipher = new Salsa20Engine();
 
-	PseudoRandom(byte[] seed) {
+	PseudoRandomImpl(byte[] seed) {
 		// Hash the seed to produce a 32-byte key
 		byte[] key = new byte[32];
 		Digest digest = new Blake2sDigest();
@@ -25,7 +26,8 @@ class PseudoRandom {
 		cipher.init(true, new ParametersWithIV(new KeyParameter(key), nonce));
 	}
 
-	byte[] nextBytes(int length) {
+	@Override
+	public byte[] nextBytes(int length) {
 		byte[] in = new byte[length], out = new byte[length];
 		cipher.processBytes(in, 0, length, out, 0);
 		return out;

bramble-core/src/main/java/org/briarproject/bramble/crypto/StreamDecrypterFactoryImpl.java

@@ -32,7 +32,7 @@ class StreamDecrypterFactoryImpl implements StreamDecrypterFactory {
 	}
 
 	@Override
-	public StreamDecrypter createContactExchangeStreamDecrypter(InputStream in,
+	public StreamDecrypter createInvitationStreamDecrypter(InputStream in,
 			SecretKey headerKey) {
 		return new StreamDecrypterImpl(in, cipherProvider.get(), 0, headerKey);
 	}

bramble-core/src/main/java/org/briarproject/bramble/crypto/StreamDecrypterImpl.java

@@ -20,11 +20,9 @@ import static org.briarproject.bramble.api.transport.TransportConstants.FRAME_NO
 import static org.briarproject.bramble.api.transport.TransportConstants.MAC_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAX_FRAME_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_IV_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_NONCE_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_PLAINTEXT_LENGTH;
-import static org.briarproject.bramble.util.ByteUtils.INT_16_BYTES;
 import static org.briarproject.bramble.util.ByteUtils.INT_64_BYTES;
 
 @NotThreadSafe
@@ -119,7 +117,7 @@ class StreamDecrypterImpl implements StreamDecrypter {
 
 	private void readStreamHeader() throws IOException {
 		byte[] streamHeaderCiphertext = new byte[STREAM_HEADER_LENGTH];
-		byte[] streamHeaderPlaintext = new byte[STREAM_HEADER_PLAINTEXT_LENGTH];
+		byte[] streamHeaderPlaintext = new byte[SecretKey.LENGTH];
 		// Read the stream header
 		int offset = 0;
 		while (offset < STREAM_HEADER_LENGTH) {
@@ -128,35 +126,21 @@ class StreamDecrypterImpl implements StreamDecrypter {
 			if (read == -1) throw new EOFException();
 			offset += read;
 		}
-		// Extract the nonce
+		// The nonce consists of the stream number followed by the IV
 		byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
-		System.arraycopy(streamHeaderCiphertext, 0, streamHeaderNonce, 0,
-				STREAM_HEADER_NONCE_LENGTH);
+		ByteUtils.writeUint64(streamNumber, streamHeaderNonce, 0);
+		System.arraycopy(streamHeaderCiphertext, 0, streamHeaderNonce,
+				INT_64_BYTES, STREAM_HEADER_IV_LENGTH);
 		// Decrypt and authenticate the stream header
 		try {
 			cipher.init(false, streamHeaderKey, streamHeaderNonce);
 			int decrypted = cipher.process(streamHeaderCiphertext,
-					STREAM_HEADER_NONCE_LENGTH,
-					STREAM_HEADER_PLAINTEXT_LENGTH + MAC_LENGTH,
+					STREAM_HEADER_IV_LENGTH, SecretKey.LENGTH + MAC_LENGTH,
 					streamHeaderPlaintext, 0);
-			if (decrypted != STREAM_HEADER_PLAINTEXT_LENGTH)
-				throw new RuntimeException();
+			if (decrypted != SecretKey.LENGTH) throw new RuntimeException();
 		} catch (GeneralSecurityException e) {
 			throw new FormatException();
 		}
-		// Check the protocol version
-		int receivedProtocolVersion =
-				ByteUtils.readUint16(streamHeaderPlaintext, 0);
-		if (receivedProtocolVersion != PROTOCOL_VERSION)
-			throw new FormatException();
-		// Check the stream number
-		long receivedStreamNumber = ByteUtils.readUint64(streamHeaderPlaintext,
-				INT_16_BYTES);
-		if (receivedStreamNumber != streamNumber) throw new FormatException();
-		// Extract the frame key
-		byte[] frameKeyBytes = new byte[SecretKey.LENGTH];
-		System.arraycopy(streamHeaderPlaintext, INT_16_BYTES + INT_64_BYTES,
-				frameKeyBytes, 0, SecretKey.LENGTH);
-		frameKey = new SecretKey(frameKeyBytes);
+		frameKey = new SecretKey(streamHeaderPlaintext);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/crypto/StreamEncrypterFactoryImpl.java

@@ -13,8 +13,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 import javax.inject.Provider;
 
-import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
-import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_NONCE_LENGTH;
+import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_IV_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
 
 @Immutable
@@ -37,22 +36,22 @@ class StreamEncrypterFactoryImpl implements StreamEncrypterFactory {
 		AuthenticatedCipher cipher = cipherProvider.get();
 		long streamNumber = ctx.getStreamNumber();
 		byte[] tag = new byte[TAG_LENGTH];
-		crypto.encodeTag(tag, ctx.getTagKey(), PROTOCOL_VERSION, streamNumber);
-		byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
-		crypto.getSecureRandom().nextBytes(streamHeaderNonce);
+		crypto.encodeTag(tag, ctx.getTagKey(), streamNumber);
+		byte[] streamHeaderIv = new byte[STREAM_HEADER_IV_LENGTH];
+		crypto.getSecureRandom().nextBytes(streamHeaderIv);
 		SecretKey frameKey = crypto.generateSecretKey();
 		return new StreamEncrypterImpl(out, cipher, streamNumber, tag,
-				streamHeaderNonce, ctx.getHeaderKey(), frameKey);
+				streamHeaderIv, ctx.getHeaderKey(), frameKey);
 	}
 
 	@Override
-	public StreamEncrypter createContactExchangeStreamDecrypter(
-			OutputStream out, SecretKey headerKey) {
+	public StreamEncrypter createInvitationStreamEncrypter(OutputStream out,
+			SecretKey headerKey) {
 		AuthenticatedCipher cipher = cipherProvider.get();
-		byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
-		crypto.getSecureRandom().nextBytes(streamHeaderNonce);
+		byte[] streamHeaderIv = new byte[STREAM_HEADER_IV_LENGTH];
+		crypto.getSecureRandom().nextBytes(streamHeaderIv);
 		SecretKey frameKey = crypto.generateSecretKey();
-		return new StreamEncrypterImpl(out, cipher, 0, null, streamHeaderNonce,
+		return new StreamEncrypterImpl(out, cipher, 0, null, streamHeaderIv,
 				headerKey, frameKey);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/crypto/StreamEncrypterImpl.java

@@ -18,11 +18,9 @@ import static org.briarproject.bramble.api.transport.TransportConstants.FRAME_NO
 import static org.briarproject.bramble.api.transport.TransportConstants.MAC_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAX_FRAME_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_IV_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_NONCE_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_PLAINTEXT_LENGTH;
-import static org.briarproject.bramble.util.ByteUtils.INT_16_BYTES;
 import static org.briarproject.bramble.util.ByteUtils.INT_64_BYTES;
 
 @NotThreadSafe
@@ -35,7 +33,7 @@ class StreamEncrypterImpl implements StreamEncrypter {
 	private final long streamNumber;
 	@Nullable
 	private final byte[] tag;
-	private final byte[] streamHeaderNonce;
+	private final byte[] streamHeaderIv;
 	private final byte[] frameNonce, frameHeader;
 	private final byte[] framePlaintext, frameCiphertext;
 
@@ -43,13 +41,13 @@ class StreamEncrypterImpl implements StreamEncrypter {
 	private boolean writeTag, writeStreamHeader;
 
 	StreamEncrypterImpl(OutputStream out, AuthenticatedCipher cipher,
-			long streamNumber, @Nullable byte[] tag, byte[] streamHeaderNonce,
+			long streamNumber, @Nullable byte[] tag, byte[] streamHeaderIv,
 			SecretKey streamHeaderKey, SecretKey frameKey) {
 		this.out = out;
 		this.cipher = cipher;
 		this.streamNumber = streamNumber;
 		this.tag = tag;
-		this.streamHeaderNonce = streamHeaderNonce;
+		this.streamHeaderIv = streamHeaderIv;
 		this.streamHeaderKey = streamHeaderKey;
 		this.frameKey = frameKey;
 		frameNonce = new byte[FRAME_NONCE_LENGTH];
@@ -116,23 +114,22 @@ class StreamEncrypterImpl implements StreamEncrypter {
 	}
 
 	private void writeStreamHeader() throws IOException {
-		// The header contains the protocol version, stream number and frame key
-		byte[] streamHeaderPlaintext = new byte[STREAM_HEADER_PLAINTEXT_LENGTH];
-		ByteUtils.writeUint16(PROTOCOL_VERSION, streamHeaderPlaintext, 0);
-		ByteUtils.writeUint64(streamNumber, streamHeaderPlaintext,
-				INT_16_BYTES);
-		System.arraycopy(frameKey.getBytes(), 0, streamHeaderPlaintext,
-				INT_16_BYTES + INT_64_BYTES, SecretKey.LENGTH);
+		// The nonce consists of the stream number followed by the IV
+		byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
+		ByteUtils.writeUint64(streamNumber, streamHeaderNonce, 0);
+		System.arraycopy(streamHeaderIv, 0, streamHeaderNonce, INT_64_BYTES,
+				STREAM_HEADER_IV_LENGTH);
+		byte[] streamHeaderPlaintext = frameKey.getBytes();
 		byte[] streamHeaderCiphertext = new byte[STREAM_HEADER_LENGTH];
-		System.arraycopy(streamHeaderNonce, 0, streamHeaderCiphertext, 0,
-				STREAM_HEADER_NONCE_LENGTH);
-		// Encrypt and authenticate the stream header key
+		System.arraycopy(streamHeaderIv, 0, streamHeaderCiphertext, 0,
+				STREAM_HEADER_IV_LENGTH);
+		// Encrypt and authenticate the frame key
 		try {
 			cipher.init(true, streamHeaderKey, streamHeaderNonce);
 			int encrypted = cipher.process(streamHeaderPlaintext, 0,
-					STREAM_HEADER_PLAINTEXT_LENGTH, streamHeaderCiphertext,
-					STREAM_HEADER_NONCE_LENGTH);
-			if (encrypted != STREAM_HEADER_PLAINTEXT_LENGTH + MAC_LENGTH)
+					SecretKey.LENGTH, streamHeaderCiphertext,
+					STREAM_HEADER_IV_LENGTH);
+			if (encrypted != SecretKey.LENGTH + MAC_LENGTH)
 				throw new RuntimeException();
 		} catch (GeneralSecurityException badCipher) {
 			throw new RuntimeException(badCipher);

bramble-core/src/main/java/org/briarproject/bramble/crypto/XSalsa20Poly1305AuthenticatedCipher.java

@@ -70,7 +70,25 @@ class XSalsa20Poly1305AuthenticatedCipher implements AuthenticatedCipher {
 			byte[] subKey = new byte[SUBKEY_LENGTH];
 			xSalsa20Engine.processBytes(zero, 0, SUBKEY_LENGTH, subKey, 0);
 
-			// Clamp the subkey
+			// Reverse the order of the Poly130 subkey
+			//
+			// NaCl and libsodium use the first 32 bytes of XSalsa20 as the
+			// subkey for crypto_onetimeauth_poly1305, which interprets it
+			// as r[0] ... r[15], k[0] ... k[15]. See section 9 of the NaCl
+			// paper (http://cr.yp.to/highspeed/naclcrypto-20090310.pdf),
+			// where the XSalsa20 output is defined as (r, s, t, ...).
+			//
+			// BC's Poly1305 implementation interprets the subkey as
+			// k[0] ... k[15], r[0] ... r[15] (per poly1305_aes_clamp in
+			// the reference implementation).
+			//
+			// To be NaCl-compatible, we reverse the subkey.
+			System.arraycopy(subKey, 0, zero, 0, SUBKEY_LENGTH / 2);
+			System.arraycopy(subKey, SUBKEY_LENGTH / 2, subKey, 0,
+					SUBKEY_LENGTH / 2);
+			System.arraycopy(zero, 0, subKey, SUBKEY_LENGTH / 2,
+					SUBKEY_LENGTH / 2);
+			// Now we can clamp the correct part of the subkey
 			Poly1305KeyGenerator.clamp(subKey);
 
 			// Initialize Poly1305 with the subkey

bramble-core/src/main/java/org/briarproject/bramble/invitation/AliceConnector.java

@@ -0,0 +1,119 @@
+package org.briarproject.bramble.invitation;
+
+import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.data.BdfReader;
+import org.briarproject.bramble.api.data.BdfReaderFactory;
+import org.briarproject.bramble.api.data.BdfWriter;
+import org.briarproject.bramble.api.data.BdfWriterFactory;
+import org.briarproject.bramble.api.identity.LocalAuthor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.security.GeneralSecurityException;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+
+/**
+ * A connection thread for the peer being Alice in the invitation protocol.
+ */
+@NotNullByDefault
+class AliceConnector extends Connector {
+
+	private static final Logger LOG =
+			Logger.getLogger(AliceConnector.class.getName());
+
+	AliceConnector(CryptoComponent crypto, BdfReaderFactory bdfReaderFactory,
+			BdfWriterFactory bdfWriterFactory,
+			ContactExchangeTask contactExchangeTask, ConnectorGroup group,
+			DuplexPlugin plugin, LocalAuthor localAuthor, PseudoRandom random) {
+		super(crypto, bdfReaderFactory, bdfWriterFactory, contactExchangeTask,
+				group, plugin, localAuthor, random);
+	}
+
+	@Override
+	public void run() {
+		// Create an incoming or outgoing connection
+		DuplexTransportConnection conn = createInvitationConnection(true);
+		if (conn == null) return;
+		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " connected");
+		// Don't proceed with more than one connection
+		if (group.getAndSetConnected()) {
+			if (LOG.isLoggable(INFO)) LOG.info(pluginName + " redundant");
+			tryToClose(conn, false);
+			return;
+		}
+		// Carry out the key agreement protocol
+		InputStream in;
+		OutputStream out;
+		BdfReader r;
+		BdfWriter w;
+		SecretKey master;
+		try {
+			in = conn.getReader().getInputStream();
+			out = conn.getWriter().getOutputStream();
+			r = bdfReaderFactory.createReader(in);
+			w = bdfWriterFactory.createWriter(out);
+			// Alice goes first
+			sendPublicKeyHash(w);
+			byte[] hash = receivePublicKeyHash(r);
+			sendPublicKey(w);
+			byte[] key = receivePublicKey(r);
+			master = deriveMasterSecret(hash, key, true);
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			group.keyAgreementFailed();
+			tryToClose(conn, true);
+			return;
+		} catch (GeneralSecurityException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			group.keyAgreementFailed();
+			tryToClose(conn, true);
+			return;
+		}
+		// The key agreement succeeded - derive the confirmation codes
+		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " agreement succeeded");
+		int aliceCode = crypto.deriveBTConfirmationCode(master, true);
+		int bobCode = crypto.deriveBTConfirmationCode(master, false);
+		group.keyAgreementSucceeded(aliceCode, bobCode);
+		// Exchange confirmation results
+		boolean localMatched, remoteMatched;
+		try {
+			localMatched = group.waitForLocalConfirmationResult();
+			sendConfirmation(w, localMatched);
+			remoteMatched = receiveConfirmation(r);
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			group.remoteConfirmationFailed();
+			tryToClose(conn, true);
+			return;
+		} catch (InterruptedException e) {
+			LOG.warning("Interrupted while waiting for confirmation");
+			group.remoteConfirmationFailed();
+			tryToClose(conn, true);
+			Thread.currentThread().interrupt();
+			return;
+		}
+		if (remoteMatched) group.remoteConfirmationSucceeded();
+		else group.remoteConfirmationFailed();
+		if (!(localMatched && remoteMatched)) {
+			if (LOG.isLoggable(INFO))
+				LOG.info(pluginName + " confirmation failed");
+			tryToClose(conn, false);
+			return;
+		}
+		// Confirmation succeeded - upgrade to a secure connection
+		if (LOG.isLoggable(INFO))
+			LOG.info(pluginName + " confirmation succeeded");
+		contactExchangeTask.startExchange(group, localAuthor, master, conn,
+				plugin.getId(), true);
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/invitation/BobConnector.java

@@ -0,0 +1,119 @@
+package org.briarproject.bramble.invitation;
+
+import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.data.BdfReader;
+import org.briarproject.bramble.api.data.BdfReaderFactory;
+import org.briarproject.bramble.api.data.BdfWriter;
+import org.briarproject.bramble.api.data.BdfWriterFactory;
+import org.briarproject.bramble.api.identity.LocalAuthor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.security.GeneralSecurityException;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+
+/**
+ * A connection thread for the peer being Bob in the invitation protocol.
+ */
+@NotNullByDefault
+class BobConnector extends Connector {
+
+	private static final Logger LOG =
+			Logger.getLogger(BobConnector.class.getName());
+
+	BobConnector(CryptoComponent crypto, BdfReaderFactory bdfReaderFactory,
+			BdfWriterFactory bdfWriterFactory,
+			ContactExchangeTask contactExchangeTask, ConnectorGroup group,
+			DuplexPlugin plugin, LocalAuthor localAuthor, PseudoRandom random) {
+		super(crypto, bdfReaderFactory, bdfWriterFactory, contactExchangeTask,
+				group, plugin, localAuthor, random);
+	}
+
+	@Override
+	public void run() {
+		// Create an incoming or outgoing connection
+		DuplexTransportConnection conn = createInvitationConnection(false);
+		if (conn == null) return;
+		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " connected");
+		// Carry out the key agreement protocol
+		InputStream in;
+		OutputStream out;
+		BdfReader r;
+		BdfWriter w;
+		SecretKey master;
+		try {
+			in = conn.getReader().getInputStream();
+			out = conn.getWriter().getOutputStream();
+			r = bdfReaderFactory.createReader(in);
+			w = bdfWriterFactory.createWriter(out);
+			// Alice goes first
+			byte[] hash = receivePublicKeyHash(r);
+			// Don't proceed with more than one connection
+			if (group.getAndSetConnected()) {
+				if (LOG.isLoggable(INFO)) LOG.info(pluginName + " redundant");
+				tryToClose(conn, false);
+				return;
+			}
+			sendPublicKeyHash(w);
+			byte[] key = receivePublicKey(r);
+			sendPublicKey(w);
+			master = deriveMasterSecret(hash, key, false);
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			group.keyAgreementFailed();
+			tryToClose(conn, true);
+			return;
+		} catch (GeneralSecurityException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			group.keyAgreementFailed();
+			tryToClose(conn, true);
+			return;
+		}
+		// The key agreement succeeded - derive the confirmation codes
+		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " agreement succeeded");
+		int aliceCode = crypto.deriveBTConfirmationCode(master, true);
+		int bobCode = crypto.deriveBTConfirmationCode(master, false);
+		group.keyAgreementSucceeded(bobCode, aliceCode);
+		// Exchange confirmation results
+		boolean localMatched, remoteMatched;
+		try {
+			remoteMatched = receiveConfirmation(r);
+			localMatched = group.waitForLocalConfirmationResult();
+			sendConfirmation(w, localMatched);
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			group.remoteConfirmationFailed();
+			tryToClose(conn, true);
+			return;
+		} catch (InterruptedException e) {
+			LOG.warning("Interrupted while waiting for confirmation");
+			group.remoteConfirmationFailed();
+			tryToClose(conn, true);
+			Thread.currentThread().interrupt();
+			return;
+		}
+		if (remoteMatched) group.remoteConfirmationSucceeded();
+		else group.remoteConfirmationFailed();
+		if (!(localMatched && remoteMatched)) {
+			if (LOG.isLoggable(INFO))
+				LOG.info(pluginName + " confirmation failed");
+			tryToClose(conn, false);
+			return;
+		}
+		// Confirmation succeeded - upgrade to a secure connection
+		if (LOG.isLoggable(INFO))
+			LOG.info(pluginName + " confirmation succeeded");
+		contactExchangeTask.startExchange(group, localAuthor, master, conn,
+				plugin.getId(), false);
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/invitation/Connector.java

@@ -0,0 +1,150 @@
+package org.briarproject.bramble.invitation;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.KeyPair;
+import org.briarproject.bramble.api.crypto.KeyParser;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.data.BdfReader;
+import org.briarproject.bramble.api.data.BdfReaderFactory;
+import org.briarproject.bramble.api.data.BdfWriter;
+import org.briarproject.bramble.api.data.BdfWriterFactory;
+import org.briarproject.bramble.api.identity.LocalAuthor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+
+import java.io.IOException;
+import java.security.GeneralSecurityException;
+import java.util.Arrays;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
+import static org.briarproject.bramble.api.invitation.InvitationConstants.CONNECTION_TIMEOUT;
+
+// FIXME: This class has way too many dependencies
+@NotNullByDefault
+abstract class Connector extends Thread {
+
+	private static final Logger LOG =
+			Logger.getLogger(Connector.class.getName());
+	private static final String LABEL_PUBLIC_KEY =
+			"org.briarproject.bramble.invitation.PUBLIC_KEY";
+
+	protected final CryptoComponent crypto;
+	protected final BdfReaderFactory bdfReaderFactory;
+	protected final BdfWriterFactory bdfWriterFactory;
+	protected final ContactExchangeTask contactExchangeTask;
+	protected final ConnectorGroup group;
+	protected final DuplexPlugin plugin;
+	protected final LocalAuthor localAuthor;
+	protected final PseudoRandom random;
+	protected final String pluginName;
+
+	private final KeyPair keyPair;
+	private final KeyParser keyParser;
+
+	Connector(CryptoComponent crypto, BdfReaderFactory bdfReaderFactory,
+			BdfWriterFactory bdfWriterFactory,
+			ContactExchangeTask contactExchangeTask, ConnectorGroup group,
+			DuplexPlugin plugin, LocalAuthor localAuthor, PseudoRandom random) {
+		super("Connector");
+		this.crypto = crypto;
+		this.bdfReaderFactory = bdfReaderFactory;
+		this.bdfWriterFactory = bdfWriterFactory;
+		this.contactExchangeTask = contactExchangeTask;
+		this.group = group;
+		this.plugin = plugin;
+		this.localAuthor = localAuthor;
+		this.random = random;
+		pluginName = plugin.getClass().getName();
+		keyPair = crypto.generateAgreementKeyPair();
+		keyParser = crypto.getAgreementKeyParser();
+	}
+
+	@Nullable
+	DuplexTransportConnection createInvitationConnection(boolean alice) {
+		if (LOG.isLoggable(INFO))
+			LOG.info(pluginName + " creating invitation connection");
+		return plugin.createInvitationConnection(random, CONNECTION_TIMEOUT,
+				alice);
+	}
+
+	void sendPublicKeyHash(BdfWriter w) throws IOException {
+		byte[] hash =
+				crypto.hash(LABEL_PUBLIC_KEY, keyPair.getPublic().getEncoded());
+		w.writeRaw(hash);
+		w.flush();
+		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " sent hash");
+	}
+
+	byte[] receivePublicKeyHash(BdfReader r) throws IOException {
+		int hashLength = crypto.getHashLength();
+		byte[] b = r.readRaw(hashLength);
+		if (b.length < hashLength) throw new FormatException();
+		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " received hash");
+		return b;
+	}
+
+	void sendPublicKey(BdfWriter w) throws IOException {
+		byte[] key = keyPair.getPublic().getEncoded();
+		w.writeRaw(key);
+		w.flush();
+		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " sent key");
+	}
+
+	byte[] receivePublicKey(BdfReader r)
+			throws GeneralSecurityException, IOException {
+		byte[] b = r.readRaw(MAX_PUBLIC_KEY_LENGTH);
+		keyParser.parsePublicKey(b);
+		if (LOG.isLoggable(INFO)) LOG.info(pluginName + " received key");
+		return b;
+	}
+
+	SecretKey deriveMasterSecret(byte[] hash, byte[] key, boolean alice)
+			throws GeneralSecurityException {
+		// Check that the hash matches the key
+		byte[] keyHash =
+				crypto.hash(LABEL_PUBLIC_KEY, keyPair.getPublic().getEncoded());
+		if (!Arrays.equals(hash, keyHash)) {
+			if (LOG.isLoggable(INFO))
+				LOG.info(pluginName + " hash does not match key");
+			throw new GeneralSecurityException();
+		}
+		//  Derive the master secret
+		if (LOG.isLoggable(INFO))
+			LOG.info(pluginName + " deriving master secret");
+		return crypto.deriveMasterSecret(key, keyPair, alice);
+	}
+
+	void sendConfirmation(BdfWriter w, boolean confirmed) throws IOException {
+		w.writeBoolean(confirmed);
+		w.flush();
+		if (LOG.isLoggable(INFO))
+			LOG.info(pluginName + " sent confirmation: " + confirmed);
+	}
+
+	boolean receiveConfirmation(BdfReader r) throws IOException {
+		boolean confirmed = r.readBoolean();
+		if (LOG.isLoggable(INFO))
+			LOG.info(pluginName + " received confirmation: " + confirmed);
+		return confirmed;
+	}
+
+	protected void tryToClose(DuplexTransportConnection conn,
+			boolean exception) {
+		try {
+			LOG.info("Closing connection");
+			conn.getReader().dispose(exception, true);
+			conn.getWriter().dispose(exception);
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/invitation/ConnectorGroup.java

@@ -0,0 +1,278 @@
+package org.briarproject.bramble.invitation;
+
+import org.briarproject.bramble.api.contact.ContactExchangeListener;
+import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
+import org.briarproject.bramble.api.data.BdfReaderFactory;
+import org.briarproject.bramble.api.data.BdfWriterFactory;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.identity.Author;
+import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.identity.LocalAuthor;
+import org.briarproject.bramble.api.invitation.InvitationListener;
+import org.briarproject.bramble.api.invitation.InvitationState;
+import org.briarproject.bramble.api.invitation.InvitationTask;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.plugin.PluginManager;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.logging.Logger;
+
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.api.invitation.InvitationConstants.CONFIRMATION_TIMEOUT;
+
+/**
+ * A task consisting of one or more parallel connection attempts.
+ */
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+class ConnectorGroup extends Thread implements InvitationTask,
+		ContactExchangeListener {
+
+	private static final Logger LOG =
+			Logger.getLogger(ConnectorGroup.class.getName());
+
+	private final CryptoComponent crypto;
+	private final BdfReaderFactory bdfReaderFactory;
+	private final BdfWriterFactory bdfWriterFactory;
+	private final ContactExchangeTask contactExchangeTask;
+	private final IdentityManager identityManager;
+	private final PluginManager pluginManager;
+	private final int localInvitationCode, remoteInvitationCode;
+	private final Collection<InvitationListener> listeners;
+	private final AtomicBoolean connected;
+	private final CountDownLatch localConfirmationLatch;
+	private final Lock lock = new ReentrantLock();
+
+	// The following are locking: lock
+	private int localConfirmationCode = -1, remoteConfirmationCode = -1;
+	private boolean connectionFailed = false;
+	private boolean localCompared = false, remoteCompared = false;
+	private boolean localMatched = false, remoteMatched = false;
+	private String remoteName = null;
+
+	ConnectorGroup(CryptoComponent crypto, BdfReaderFactory bdfReaderFactory,
+			BdfWriterFactory bdfWriterFactory,
+			ContactExchangeTask contactExchangeTask,
+			IdentityManager identityManager, PluginManager pluginManager,
+			int localInvitationCode, int remoteInvitationCode) {
+		super("ConnectorGroup");
+		this.crypto = crypto;
+		this.bdfReaderFactory = bdfReaderFactory;
+		this.bdfWriterFactory = bdfWriterFactory;
+		this.contactExchangeTask = contactExchangeTask;
+		this.identityManager = identityManager;
+		this.pluginManager = pluginManager;
+		this.localInvitationCode = localInvitationCode;
+		this.remoteInvitationCode = remoteInvitationCode;
+		listeners = new CopyOnWriteArrayList<InvitationListener>();
+		connected = new AtomicBoolean(false);
+		localConfirmationLatch = new CountDownLatch(1);
+	}
+
+	@Override
+	public InvitationState addListener(InvitationListener l) {
+		lock.lock();
+		try {
+			listeners.add(l);
+			return new InvitationState(localInvitationCode,
+					remoteInvitationCode, localConfirmationCode,
+					remoteConfirmationCode, connected.get(), connectionFailed,
+					localCompared, remoteCompared, localMatched, remoteMatched,
+					remoteName);
+		} finally {
+			lock.unlock();
+		}
+	}
+
+	@Override
+	public void removeListener(InvitationListener l) {
+		listeners.remove(l);
+	}
+
+	@Override
+	public void connect() {
+		start();
+	}
+
+	@Override
+	public void run() {
+		LocalAuthor localAuthor;
+		// Load the local pseudonym
+		try {
+			localAuthor = identityManager.getLocalAuthor();
+		} catch (DbException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			lock.lock();
+			try {
+				connectionFailed = true;
+			} finally {
+				lock.unlock();
+			}
+			for (InvitationListener l : listeners) l.connectionFailed();
+			return;
+		}
+		// Start the connection threads
+		Collection<Connector> connectors = new ArrayList<Connector>();
+		// Alice is the party with the smaller invitation code
+		if (localInvitationCode < remoteInvitationCode) {
+			for (DuplexPlugin plugin : pluginManager.getInvitationPlugins()) {
+				Connector c = createAliceConnector(plugin, localAuthor);
+				connectors.add(c);
+				c.start();
+			}
+		} else {
+			for (DuplexPlugin plugin : pluginManager.getInvitationPlugins()) {
+				Connector c = createBobConnector(plugin, localAuthor);
+				connectors.add(c);
+				c.start();
+			}
+		}
+		// Wait for the connection threads to finish
+		try {
+			for (Connector c : connectors) c.join();
+		} catch (InterruptedException e) {
+			LOG.warning("Interrupted while waiting for connectors");
+			Thread.currentThread().interrupt();
+		}
+		// If none of the threads connected, inform the listeners
+		if (!connected.get()) {
+			lock.lock();
+			try {
+				connectionFailed = true;
+			} finally {
+				lock.unlock();
+			}
+			for (InvitationListener l : listeners) l.connectionFailed();
+		}
+	}
+
+	private Connector createAliceConnector(DuplexPlugin plugin,
+			LocalAuthor localAuthor) {
+		PseudoRandom random = crypto.getPseudoRandom(localInvitationCode,
+				remoteInvitationCode);
+		return new AliceConnector(crypto, bdfReaderFactory, bdfWriterFactory,
+				contactExchangeTask, this, plugin, localAuthor, random);
+	}
+
+	private Connector createBobConnector(DuplexPlugin plugin,
+			LocalAuthor localAuthor) {
+		PseudoRandom random = crypto.getPseudoRandom(remoteInvitationCode,
+				localInvitationCode);
+		return new BobConnector(crypto, bdfReaderFactory, bdfWriterFactory,
+				contactExchangeTask, this, plugin, localAuthor, random);
+	}
+
+	@Override
+	public void localConfirmationSucceeded() {
+		lock.lock();
+		try {
+			localCompared = true;
+			localMatched = true;
+		} finally {
+			lock.unlock();
+		}
+		localConfirmationLatch.countDown();
+	}
+
+	@Override
+	public void localConfirmationFailed() {
+		lock.lock();
+		try {
+			localCompared = true;
+			localMatched = false;
+		} finally {
+			lock.unlock();
+		}
+		localConfirmationLatch.countDown();
+	}
+
+	boolean getAndSetConnected() {
+		boolean redundant = connected.getAndSet(true);
+		if (!redundant)
+			for (InvitationListener l : listeners) l.connectionSucceeded();
+		return redundant;
+	}
+
+	void keyAgreementSucceeded(int localCode, int remoteCode) {
+		lock.lock();
+		try {
+			localConfirmationCode = localCode;
+			remoteConfirmationCode = remoteCode;
+		} finally {
+			lock.unlock();
+		}
+		for (InvitationListener l : listeners)
+			l.keyAgreementSucceeded(localCode, remoteCode);
+	}
+
+	void keyAgreementFailed() {
+		for (InvitationListener l : listeners) l.keyAgreementFailed();
+	}
+
+	boolean waitForLocalConfirmationResult() throws InterruptedException {
+		localConfirmationLatch.await(CONFIRMATION_TIMEOUT, MILLISECONDS);
+		lock.lock();
+		try {
+			return localMatched;
+		} finally {
+			lock.unlock();
+		}
+	}
+
+	void remoteConfirmationSucceeded() {
+		lock.lock();
+		try {
+			remoteCompared = true;
+			remoteMatched = true;
+		} finally {
+			lock.unlock();
+		}
+		for (InvitationListener l : listeners) l.remoteConfirmationSucceeded();
+	}
+
+	void remoteConfirmationFailed() {
+		lock.lock();
+		try {
+			remoteCompared = true;
+			remoteMatched = false;
+		} finally {
+			lock.unlock();
+		}
+		for (InvitationListener l : listeners) l.remoteConfirmationFailed();
+	}
+
+	@Override
+	public void contactExchangeSucceeded(Author remoteAuthor) {
+		String name = remoteAuthor.getName();
+		lock.lock();
+		try {
+			remoteName = name;
+		} finally {
+			lock.unlock();
+		}
+		for (InvitationListener l : listeners)
+			l.pseudonymExchangeSucceeded(name);
+	}
+
+	@Override
+	public void duplicateContact(Author remoteAuthor) {
+		// TODO differentiate
+		for (InvitationListener l : listeners) l.pseudonymExchangeFailed();
+	}
+
+	@Override
+	public void contactExchangeFailed() {
+		for (InvitationListener l : listeners) l.pseudonymExchangeFailed();
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/invitation/InvitationModule.java

@@ -0,0 +1,16 @@
+package org.briarproject.bramble.invitation;
+
+import org.briarproject.bramble.api.invitation.InvitationTaskFactory;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class InvitationModule {
+
+	@Provides
+	InvitationTaskFactory provideInvitationTaskFactory(
+			InvitationTaskFactoryImpl invitationTaskFactory) {
+		return invitationTaskFactory;
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/invitation/InvitationTaskFactoryImpl.java

@@ -0,0 +1,47 @@
+package org.briarproject.bramble.invitation;
+
+import org.briarproject.bramble.api.contact.ContactExchangeTask;
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.data.BdfReaderFactory;
+import org.briarproject.bramble.api.data.BdfWriterFactory;
+import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.invitation.InvitationTask;
+import org.briarproject.bramble.api.invitation.InvitationTaskFactory;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.PluginManager;
+
+import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
+
+@Immutable
+@NotNullByDefault
+class InvitationTaskFactoryImpl implements InvitationTaskFactory {
+
+	private final CryptoComponent crypto;
+	private final BdfReaderFactory bdfReaderFactory;
+	private final BdfWriterFactory bdfWriterFactory;
+	private final ContactExchangeTask contactExchangeTask;
+	private final IdentityManager identityManager;
+	private final PluginManager pluginManager;
+
+	@Inject
+	InvitationTaskFactoryImpl(CryptoComponent crypto,
+			BdfReaderFactory bdfReaderFactory,
+			BdfWriterFactory bdfWriterFactory,
+			ContactExchangeTask contactExchangeTask,
+			IdentityManager identityManager, PluginManager pluginManager) {
+		this.crypto = crypto;
+		this.bdfReaderFactory = bdfReaderFactory;
+		this.bdfWriterFactory = bdfWriterFactory;
+		this.contactExchangeTask = contactExchangeTask;
+		this.identityManager = identityManager;
+		this.pluginManager = pluginManager;
+	}
+
+	@Override
+	public InvitationTask createTask(int localCode, int remoteCode) {
+		return new ConnectorGroup(crypto, bdfReaderFactory, bdfWriterFactory,
+				contactExchangeTask, identityManager, pluginManager,
+				localCode, remoteCode);
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/plugin/PluginManagerImpl.java

@@ -164,6 +164,14 @@ class PluginManagerImpl implements PluginManager, Service {
 		return new ArrayList<DuplexPlugin>(duplexPlugins);
 	}
 
+	@Override
+	public Collection<DuplexPlugin> getInvitationPlugins() {
+		List<DuplexPlugin> supported = new ArrayList<DuplexPlugin>();
+		for (DuplexPlugin d : duplexPlugins)
+			if (d.supportsInvitations()) supported.add(d);
+		return supported;
+	}
+
 	@Override
 	public Collection<DuplexPlugin> getKeyAgreementPlugins() {
 		List<DuplexPlugin> supported = new ArrayList<DuplexPlugin>();
@@ -283,16 +291,6 @@ class PluginManagerImpl implements PluginManager, Service {
 			}
 		}
 
-		@Override
-		public TransportProperties getRemoteProperties(ContactId c) {
-			try {
-				return transportPropertyManager.getRemoteProperties(c, id);
-			} catch (DbException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-				return new TransportProperties();
-			}
-		}
-
 		@Override
 		public void mergeSettings(Settings s) {
 			try {

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/LanTcpPlugin.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin.tcp;
 
 import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
@@ -34,7 +35,6 @@ import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_LAN;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.PREF_LAN_IP_PORTS;
-import static org.briarproject.bramble.api.plugin.LanTcpConstants.PROP_IP_PORTS;
 import static org.briarproject.bramble.util.ByteUtils.MAX_16_BIT_UNSIGNED;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubSocketAddress;
 
@@ -45,6 +45,7 @@ class LanTcpPlugin extends TcpPlugin {
 			Logger.getLogger(LanTcpPlugin.class.getName());
 
 	private static final int MAX_ADDRESSES = 4;
+	private static final String PROP_IP_PORTS = "ipPorts";
 	private static final String SEPARATOR = ",";
 
 	LanTcpPlugin(Executor ioExecutor, Backoff backoff,
@@ -125,8 +126,9 @@ class LanTcpPlugin extends TcpPlugin {
 	}
 
 	@Override
-	protected List<InetSocketAddress> getRemoteSocketAddresses(
-			TransportProperties p) {
+	protected List<InetSocketAddress> getRemoteSocketAddresses(ContactId c) {
+		TransportProperties p = callback.getRemoteProperties().get(c);
+		if (p == null) return Collections.emptyList();
 		return parseSocketAddresses(p.get(PROP_IP_PORTS));
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/TcpPlugin.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin.tcp;
 
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -9,7 +10,6 @@ import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.util.StringUtils;
 
 import java.io.IOException;
@@ -25,8 +25,6 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
@@ -69,11 +67,11 @@ abstract class TcpPlugin implements DuplexPlugin {
 	protected abstract void setLocalSocketAddress(InetSocketAddress a);
 
 	/**
-	 * Returns zero or more socket addresses for connecting to a contact with
-	 * the given transport properties.
+	 * Returns zero or more socket addresses for connecting to the given
+	 * contact.
 	 */
 	protected abstract List<InetSocketAddress> getRemoteSocketAddresses(
-			TransportProperties p);
+			ContactId c);
 
 	/**
 	 * Returns true if connections to the given address can be attempted.
@@ -210,21 +208,16 @@ abstract class TcpPlugin implements DuplexPlugin {
 	public void poll(Collection<ContactId> connected) {
 		if (!isRunning()) return;
 		backoff.increment();
-		Map<ContactId, TransportProperties> remote =
-				callback.getRemoteProperties();
-		for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {
-			ContactId c = e.getKey();
-			if (!connected.contains(c)) connectAndCallBack(c, e.getValue());
-		}
+		// TODO: Pass properties to connectAndCallBack()
+		for (ContactId c : callback.getRemoteProperties().keySet())
+			if (!connected.contains(c)) connectAndCallBack(c);
 	}
 
-	private void connectAndCallBack(final ContactId c,
-			final TransportProperties p) {
+	private void connectAndCallBack(final ContactId c) {
 		ioExecutor.execute(new Runnable() {
 			@Override
 			public void run() {
-				if (!isRunning()) return;
-				DuplexTransportConnection d = createConnection(p);
+				DuplexTransportConnection d = createConnection(c);
 				if (d != null) {
 					backoff.reset();
 					callback.outgoingConnectionCreated(c, d);
@@ -236,12 +229,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 	@Override
 	public DuplexTransportConnection createConnection(ContactId c) {
 		if (!isRunning()) return null;
-		return createConnection(callback.getRemoteProperties(c));
-	}
-
-	@Nullable
-	private DuplexTransportConnection createConnection(TransportProperties p) {
-		for (InetSocketAddress remote : getRemoteSocketAddresses(p)) {
+		for (InetSocketAddress remote : getRemoteSocketAddresses(c)) {
 			if (!isConnectable(remote)) {
 				if (LOG.isLoggable(INFO)) {
 					SocketAddress local = socket.getLocalSocketAddress();
@@ -293,6 +281,17 @@ abstract class TcpPlugin implements DuplexPlugin {
 		}
 	}
 
+	@Override
+	public boolean supportsInvitations() {
+		return false;
+	}
+
+	@Override
+	public DuplexTransportConnection createInvitationConnection(PseudoRandom r,
+			long timeout, boolean alice) {
+		throw new UnsupportedOperationException();
+	}
+
 	@Override
 	public boolean supportsKeyAgreement() {
 		return false;

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/TcpTransportConnection.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.plugin.tcp;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.duplex.AbstractDuplexTransportConnection;
-import org.briarproject.bramble.util.IoUtils;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -25,12 +24,12 @@ class TcpTransportConnection extends AbstractDuplexTransportConnection {
 
 	@Override
 	protected InputStream getInputStream() throws IOException {
-		return IoUtils.getInputStream(socket);
+		return socket.getInputStream();
 	}
 
 	@Override
 	protected OutputStream getOutputStream() throws IOException {
-		return IoUtils.getOutputStream(socket);
+		return socket.getOutputStream();
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/plugin/tcp/WanTcpPlugin.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.plugin.tcp;
 
+import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
@@ -77,8 +78,9 @@ class WanTcpPlugin extends TcpPlugin {
 	}
 
 	@Override
-	protected List<InetSocketAddress> getRemoteSocketAddresses(
-			TransportProperties p) {
+	protected List<InetSocketAddress> getRemoteSocketAddresses(ContactId c) {
+		TransportProperties p = callback.getRemoteProperties().get(c);
+		if (p == null) return Collections.emptyList();
 		InetSocketAddress parsed = parseSocketAddress(p.get(PROP_IP_PORT));
 		if (parsed == null) return Collections.emptyList();
 		return Collections.singletonList(parsed);

bramble-core/src/main/java/org/briarproject/bramble/properties/TransportPropertyManagerImpl.java

@@ -160,52 +160,35 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	@Override
 	public Map<ContactId, TransportProperties> getRemoteProperties(
 			TransportId t) throws DbException {
-		Map<ContactId, TransportProperties> remote =
-				new HashMap<ContactId, TransportProperties>();
-		Transaction txn = db.startTransaction(true);
 		try {
-			for (Contact c : db.getContacts(txn))
-				remote.put(c.getId(), getRemoteProperties(txn, c, t));
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
-		}
-		return remote;
-	}
-
-	private TransportProperties getRemoteProperties(Transaction txn, Contact c,
-			TransportId t) throws DbException {
-		// Don't return properties for inactive contacts
-		if (!c.isActive()) return new TransportProperties();
-		Group g = getContactGroup(c);
-		try {
-			// Find the latest remote update
-			LatestUpdate latest = findLatest(txn, g.getId(), t, false);
-			if (latest == null) return new TransportProperties();
-			// Retrieve and parse the latest remote properties
-			BdfList message =
-					clientHelper.getMessageAsList(txn, latest.messageId);
-			if (message == null) throw new DbException();
-			return parseProperties(message);
+			Map<ContactId, TransportProperties> remote =
+					new HashMap<ContactId, TransportProperties>();
+			Transaction txn = db.startTransaction(true);
+			try {
+				for (Contact c : db.getContacts(txn)) {
+					// Don't return properties for inactive contacts
+					if (!c.isActive()) continue;
+					Group g = getContactGroup(c);
+					// Find the latest remote update
+					LatestUpdate latest = findLatest(txn, g.getId(), t, false);
+					if (latest != null) {
+						// Retrieve and parse the latest remote properties
+						BdfList message = clientHelper.getMessageAsList(txn,
+								latest.messageId);
+						if (message == null) throw new DbException();
+						remote.put(c.getId(), parseProperties(message));
+					}
+				}
+				db.commitTransaction(txn);
+			} finally {
+				db.endTransaction(txn);
+			}
+			return remote;
 		} catch (FormatException e) {
 			throw new DbException(e);
 		}
 	}
 
-	@Override
-	public TransportProperties getRemoteProperties(ContactId c, TransportId t)
-			throws DbException {
-		TransportProperties p;
-		Transaction txn = db.startTransaction(true);
-		try {
-			p = getRemoteProperties(txn, db.getContact(txn, c), t);
-			db.commitTransaction(txn);
-		} finally {
-			db.endTransaction(txn);
-		}
-		return p;
-	}
-
 	@Override
 	public void mergeLocalProperties(TransportId t, TransportProperties p)
 			throws DbException {

bramble-core/src/main/java/org/briarproject/bramble/reporting/DevReportServer.java

@@ -1,7 +1,6 @@
 package org.briarproject.bramble.reporting;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.util.IoUtils;
 
 import java.io.Closeable;
 import java.io.File;
@@ -131,7 +130,7 @@ public class DevReportServer {
 			OutputStream out = null;
 			try {
 				socket.setSoTimeout(SOCKET_TIMEOUT_MS);
-				in = IoUtils.getInputStream(socket);
+				in = socket.getInputStream();
 				reportDir.mkdirs();
 				reportFile = File.createTempFile(FILE_PREFIX, FILE_SUFFIX,
 						reportDir);

bramble-core/src/main/java/org/briarproject/bramble/reporting/DevReporterImpl.java

@@ -93,7 +93,7 @@ class DevReporterImpl implements DevReporter {
 			InputStream in = null;
 			try {
 				Socket s = connectToDevelopers();
-				out = IoUtils.getOutputStream(s);
+				out = s.getOutputStream();
 				in = new FileInputStream(f);
 				IoUtils.copyAndClose(in, out);
 				f.delete();

bramble-core/src/main/java/org/briarproject/bramble/socks/SocksSocket.java

@@ -57,8 +57,8 @@ class SocksSocket extends Socket {
 
 		// Connect to the proxy
 		super.connect(proxy, connectToProxyTimeout);
-		OutputStream out = IoUtils.getOutputStream(this);
-		InputStream in = IoUtils.getInputStream(this);
+		OutputStream out = getOutputStream();
+		InputStream in = getInputStream();
 
 		// Request SOCKS 5 with no authentication
 		sendMethodRequest(out);

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

@@ -29,10 +29,10 @@ class StreamReaderFactoryImpl implements StreamReaderFactory {
 	}
 
 	@Override
-	public InputStream createContactExchangeStreamReader(InputStream in,
+	public InputStream createInvitationStreamReader(InputStream in,
 			SecretKey headerKey) {
 		return new StreamReaderImpl(
-				streamDecrypterFactory.createContactExchangeStreamDecrypter(in,
+				streamDecrypterFactory.createInvitationStreamDecrypter(in,
 						headerKey));
 	}
 }

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

@@ -30,10 +30,10 @@ class StreamWriterFactoryImpl implements StreamWriterFactory {
 	}
 
 	@Override
-	public OutputStream createContactExchangeStreamWriter(OutputStream out,
+	public OutputStream createInvitationStreamWriter(OutputStream out,
 			SecretKey headerKey) {
 		return new StreamWriterImpl(
-				streamEncrypterFactory.createContactExchangeStreamDecrypter(out,
+				streamEncrypterFactory.createInvitationStreamEncrypter(out,
 						headerKey));
 	}
 }

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

@@ -29,7 +29,6 @@ import javax.annotation.concurrent.ThreadSafe;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.WARNING;
 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;
 import static org.briarproject.bramble.util.ByteUtils.MAX_32_BIT_UNSIGNED;
 
@@ -127,8 +126,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		for (long streamNumber : inKeys.getWindow().getUnseen()) {
 			TagContext tagCtx = new TagContext(c, inKeys, streamNumber);
 			byte[] tag = new byte[TAG_LENGTH];
-			crypto.encodeTag(tag, inKeys.getTagKey(), PROTOCOL_VERSION,
-					streamNumber);
+			crypto.encodeTag(tag, inKeys.getTagKey(), streamNumber);
 			inContexts.put(new Bytes(tag), tagCtx);
 		}
 	}
@@ -244,8 +242,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 			// Add tags for any stream numbers added to the window
 			for (long streamNumber : change.getAdded()) {
 				byte[] addTag = new byte[TAG_LENGTH];
-				crypto.encodeTag(addTag, inKeys.getTagKey(), PROTOCOL_VERSION,
-						streamNumber);
+				crypto.encodeTag(addTag, inKeys.getTagKey(), streamNumber);
 				inContexts.put(new Bytes(addTag), new TagContext(
 						tagCtx.contactId, inKeys, streamNumber));
 			}
@@ -253,8 +250,7 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 			for (long streamNumber : change.getRemoved()) {
 				if (streamNumber == tagCtx.streamNumber) continue;
 				byte[] removeTag = new byte[TAG_LENGTH];
-				crypto.encodeTag(removeTag, inKeys.getTagKey(),
-						PROTOCOL_VERSION, streamNumber);
+				crypto.encodeTag(removeTag, inKeys.getTagKey(), streamNumber);
 				inContexts.remove(new Bytes(removeTag));
 			}
 			// Write the window back to the DB

bramble-core/src/test/java/org/briarproject/bramble/client/ClientHelperImplTest.java

@@ -20,7 +20,7 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.util.StringUtils;
+import org.briarproject.bramble.test.TestUtils;
 import org.jmock.Expectations;
 import org.jmock.Mockery;
 import org.junit.Test;
@@ -65,7 +65,7 @@ public class ClientHelperImplTest extends BrambleTestCase {
 			new Message(messageId, groupId, timestamp, rawMessage);
 	private final Metadata metadata = new Metadata();
 	private final BdfList list = BdfList.of("Sign this!", getRandomBytes(42));
-	private final String label = StringUtils.getRandomString(5);
+	private final String label = TestUtils.getRandomString(5);
 
 	public ClientHelperImplTest() {
 		clientHelper =

bramble-core/src/test/java/org/briarproject/bramble/crypto/HashTest.java

@@ -4,7 +4,6 @@ import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestSecureRandomProvider;
 import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.junit.Test;
 
 import java.util.Arrays;
@@ -16,7 +15,7 @@ public class HashTest extends BrambleTestCase {
 
 	private final CryptoComponent crypto;
 
-	private final String label = StringUtils.getRandomString(42);
+	private final String label = TestUtils.getRandomString(42);
 	private final byte[] inputBytes = TestUtils.getRandomBytes(123);
 	private final byte[] inputBytes1 = TestUtils.getRandomBytes(234);
 	private final byte[] inputBytes2 = new byte[0];
@@ -41,7 +40,7 @@ public class HashTest extends BrambleTestCase {
 
 	@Test
 	public void testDifferentLabelsProduceDifferentHashes() {
-		String label2 = StringUtils.getRandomString(42);
+		String label2 = TestUtils.getRandomString(42);
 		byte[] hash1 = crypto.hash(label, inputBytes, inputBytes1, inputBytes2);
 		byte[] hash2 =
 				crypto.hash(label2, inputBytes, inputBytes1, inputBytes2);

bramble-core/src/test/java/org/briarproject/bramble/crypto/PseudoSecureRandom.java

@@ -1,5 +1,7 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.api.crypto.PseudoRandom;
+
 import java.security.Provider;
 import java.security.SecureRandom;
 import java.security.SecureRandomSpi;
@@ -17,7 +19,7 @@ class PseudoSecureRandom extends SecureRandom {
 		private final PseudoRandom pseudoRandom;
 
 		private PseudoSecureRandomSpi(byte[] seed) {
-			pseudoRandom = new PseudoRandom(seed);
+			pseudoRandom = new PseudoRandomImpl(seed);
 		}
 
 		@Override

bramble-core/src/test/java/org/briarproject/bramble/crypto/SignatureTest.java

@@ -5,7 +5,6 @@ import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestSecureRandomProvider;
 import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.junit.Test;
 
 import java.util.Arrays;
@@ -19,7 +18,7 @@ public class SignatureTest extends BrambleTestCase {
 	private final CryptoComponent crypto;
 
 	private final byte[] publicKey, privateKey;
-	private final String label = StringUtils.getRandomString(42);
+	private final String label = TestUtils.getRandomString(42);
 	private final byte[] inputBytes = TestUtils.getRandomBytes(123);
 
 	public SignatureTest() {
@@ -65,7 +64,7 @@ public class SignatureTest extends BrambleTestCase {
 	public void testDifferentLabelsProduceDifferentSignatures()
 			throws Exception {
 		// Generate a second label
-		String label2 = StringUtils.getRandomString(42);
+		String label2 = TestUtils.getRandomString(42);
 		// Calculate the signature with different inputs
 		// the results should be different
 		byte[] sig1 = crypto.sign(label, inputBytes, privateKey);
@@ -101,7 +100,7 @@ public class SignatureTest extends BrambleTestCase {
 	@Test
 	public void testDifferentLabelFailsVerification() throws Exception {
 		// Generate a second label
-		String label2 = StringUtils.getRandomString(42);
+		String label2 = TestUtils.getRandomString(42);
 		// calculate the signature with different label, should fail to verify
 		byte[] sig = crypto.sign(label, inputBytes, privateKey);
 		assertFalse(crypto.verify(label2, inputBytes, publicKey, sig));

bramble-core/src/test/java/org/briarproject/bramble/crypto/StreamDecrypterImplTest.java

@@ -14,8 +14,7 @@ import static junit.framework.Assert.assertEquals;
 import static org.briarproject.bramble.api.transport.TransportConstants.FRAME_HEADER_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAC_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
-import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_NONCE_LENGTH;
+import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_IV_LENGTH;
 import static org.briarproject.bramble.util.ByteUtils.INT_16_BYTES;
 import static org.junit.Assert.assertArrayEquals;
 
@@ -23,8 +22,7 @@ public class StreamDecrypterImplTest extends BrambleTestCase {
 
 	private final AuthenticatedCipher cipher;
 	private final SecretKey streamHeaderKey, frameKey;
-	private final byte[] streamHeaderNonce, protocolVersionBytes;
-	private final byte[] streamNumberBytes, payload;
+	private final byte[] streamHeaderIv, payload;
 	private final int payloadLength = 123, paddingLength = 234;
 	private final long streamNumber = 1234;
 
@@ -32,12 +30,7 @@ public class StreamDecrypterImplTest extends BrambleTestCase {
 		cipher = new TestAuthenticatedCipher(); // Null cipher
 		streamHeaderKey = TestUtils.getSecretKey();
 		frameKey = TestUtils.getSecretKey();
-		streamHeaderNonce =
-				TestUtils.getRandomBytes(STREAM_HEADER_NONCE_LENGTH);
-		protocolVersionBytes = new byte[2];
-		ByteUtils.writeUint16(PROTOCOL_VERSION, protocolVersionBytes, 0);
-		streamNumberBytes = new byte[8];
-		ByteUtils.writeUint64(streamNumber, streamNumberBytes, 0);
+		streamHeaderIv = TestUtils.getRandomBytes(STREAM_HEADER_IV_LENGTH);
 		payload = TestUtils.getRandomBytes(payloadLength);
 	}
 
@@ -54,9 +47,7 @@ public class StreamDecrypterImplTest extends BrambleTestCase {
 		byte[] payload1 = TestUtils.getRandomBytes(payloadLength1);
 
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(streamHeaderNonce);
-		out.write(protocolVersionBytes);
-		out.write(streamNumberBytes);
+		out.write(streamHeaderIv);
 		out.write(frameKey.getBytes());
 		out.write(new byte[MAC_LENGTH]);
 		out.write(frameHeader);
@@ -85,85 +76,6 @@ public class StreamDecrypterImplTest extends BrambleTestCase {
 		assertEquals(-1, s.readFrame(buffer));
 	}
 
-	@Test(expected = IOException.class)
-	public void testWrongProtocolVersionThrowsException() throws Exception {
-		byte[] wrongProtocolVersionBytes = new byte[2];
-		ByteUtils.writeUint16(PROTOCOL_VERSION + 1, wrongProtocolVersionBytes,
-				0);
-
-		byte[] frameHeader = new byte[FRAME_HEADER_LENGTH];
-		FrameEncoder.encodeHeader(frameHeader, false, payloadLength,
-				paddingLength);
-
-		byte[] frameHeader1 = new byte[FRAME_HEADER_LENGTH];
-		int payloadLength1 = 345, paddingLength1 = 456;
-		FrameEncoder.encodeHeader(frameHeader1, true, payloadLength1,
-				paddingLength1);
-		byte[] payload1 = TestUtils.getRandomBytes(payloadLength1);
-
-		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(streamHeaderNonce);
-		out.write(wrongProtocolVersionBytes);
-		out.write(streamNumberBytes);
-		out.write(frameKey.getBytes());
-		out.write(new byte[MAC_LENGTH]);
-		out.write(frameHeader);
-		out.write(payload);
-		out.write(new byte[paddingLength]);
-		out.write(new byte[MAC_LENGTH]);
-		out.write(frameHeader1);
-		out.write(payload1);
-		out.write(new byte[paddingLength1]);
-		out.write(new byte[MAC_LENGTH]);
-
-		ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
-		StreamDecrypterImpl s = new StreamDecrypterImpl(in, cipher,
-				streamNumber, streamHeaderKey);
-
-		// Try to read the first frame
-		byte[] buffer = new byte[MAX_PAYLOAD_LENGTH];
-		s.readFrame(buffer);
-	}
-
-	@Test(expected = IOException.class)
-	public void testWrongStreamNumberThrowsException() throws Exception {
-		byte[] wrongStreamNumberBytes = new byte[8];
-		ByteUtils.writeUint64(streamNumber + 1, wrongStreamNumberBytes, 0);
-
-		byte[] frameHeader = new byte[FRAME_HEADER_LENGTH];
-		FrameEncoder.encodeHeader(frameHeader, false, payloadLength,
-				paddingLength);
-
-		byte[] frameHeader1 = new byte[FRAME_HEADER_LENGTH];
-		int payloadLength1 = 345, paddingLength1 = 456;
-		FrameEncoder.encodeHeader(frameHeader1, true, payloadLength1,
-				paddingLength1);
-		byte[] payload1 = TestUtils.getRandomBytes(payloadLength1);
-
-		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(streamHeaderNonce);
-		out.write(protocolVersionBytes);
-		out.write(wrongStreamNumberBytes);
-		out.write(frameKey.getBytes());
-		out.write(new byte[MAC_LENGTH]);
-		out.write(frameHeader);
-		out.write(payload);
-		out.write(new byte[paddingLength]);
-		out.write(new byte[MAC_LENGTH]);
-		out.write(frameHeader1);
-		out.write(payload1);
-		out.write(new byte[paddingLength1]);
-		out.write(new byte[MAC_LENGTH]);
-
-		ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
-		StreamDecrypterImpl s = new StreamDecrypterImpl(in, cipher,
-				streamNumber, streamHeaderKey);
-
-		// Try to read the first frame
-		byte[] buffer = new byte[MAX_PAYLOAD_LENGTH];
-		s.readFrame(buffer);
-	}
-
 	@Test(expected = IOException.class)
 	public void testTruncatedFrameThrowsException() throws Exception {
 		byte[] frameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -171,9 +83,7 @@ public class StreamDecrypterImplTest extends BrambleTestCase {
 				paddingLength);
 
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(streamHeaderNonce);
-		out.write(protocolVersionBytes);
-		out.write(streamNumberBytes);
+		out.write(streamHeaderIv);
 		out.write(frameKey.getBytes());
 		out.write(new byte[MAC_LENGTH]);
 		out.write(frameHeader);
@@ -201,9 +111,7 @@ public class StreamDecrypterImplTest extends BrambleTestCase {
 		byte[] payload = TestUtils.getRandomBytes(payloadLength);
 
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(streamHeaderNonce);
-		out.write(protocolVersionBytes);
-		out.write(streamNumberBytes);
+		out.write(streamHeaderIv);
 		out.write(frameKey.getBytes());
 		out.write(new byte[MAC_LENGTH]);
 		out.write(frameHeader);
@@ -230,9 +138,7 @@ public class StreamDecrypterImplTest extends BrambleTestCase {
 		padding[paddingLength - 1] = 1;
 
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(streamHeaderNonce);
-		out.write(protocolVersionBytes);
-		out.write(streamNumberBytes);
+		out.write(streamHeaderIv);
 		out.write(frameKey.getBytes());
 		out.write(new byte[MAC_LENGTH]);
 		out.write(frameHeader);
@@ -256,9 +162,7 @@ public class StreamDecrypterImplTest extends BrambleTestCase {
 				paddingLength);
 
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		out.write(streamHeaderNonce);
-		out.write(protocolVersionBytes);
-		out.write(streamNumberBytes);
+		out.write(streamHeaderIv);
 		out.write(frameKey.getBytes());
 		out.write(new byte[MAC_LENGTH]);
 		out.write(frameHeader);

bramble-core/src/test/java/org/briarproject/bramble/crypto/StreamEncrypterImplTest.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.crypto;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.ByteUtils;
 import org.junit.Test;
 
 import java.io.ByteArrayOutputStream;
@@ -12,9 +11,8 @@ import static org.briarproject.bramble.api.transport.TransportConstants.FRAME_HE
 import static org.briarproject.bramble.api.transport.TransportConstants.MAC_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAX_FRAME_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_IV_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_NONCE_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
@@ -23,8 +21,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 
 	private final AuthenticatedCipher cipher;
 	private final SecretKey streamHeaderKey, frameKey;
-	private final byte[] tag, streamHeaderNonce, protocolVersionBytes;
-	private final byte[] streamNumberBytes, payload;
+	private final byte[] tag, streamHeaderIv, payload;
 	private final long streamNumber = 1234;
 	private final int payloadLength = 123, paddingLength = 234;
 
@@ -33,12 +30,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 		streamHeaderKey = TestUtils.getSecretKey();
 		frameKey = TestUtils.getSecretKey();
 		tag = TestUtils.getRandomBytes(TAG_LENGTH);
-		streamHeaderNonce =
-				TestUtils.getRandomBytes(STREAM_HEADER_NONCE_LENGTH);
-		protocolVersionBytes = new byte[2];
-		ByteUtils.writeUint16(PROTOCOL_VERSION, protocolVersionBytes, 0);
-		streamNumberBytes = new byte[8];
-		ByteUtils.writeUint64(streamNumber, streamNumberBytes, 0);
+		streamHeaderIv = TestUtils.getRandomBytes(STREAM_HEADER_IV_LENGTH);
 		payload = TestUtils.getRandomBytes(payloadLength);
 	}
 
@@ -46,8 +38,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testRejectsNegativePayloadLength() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, -1, 0, false);
 	}
@@ -56,8 +47,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testRejectsNegativePaddingLength() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, 0, -1, false);
 	}
@@ -66,8 +56,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testRejectsMaxPayloadPlusPadding() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		byte[] bigPayload = new byte[MAX_PAYLOAD_LENGTH + 1];
 		s.writeFrame(bigPayload, MAX_PAYLOAD_LENGTH, 1, false);
@@ -77,8 +66,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testAcceptsMaxPayloadIncludingPadding() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		byte[] bigPayload = new byte[MAX_PAYLOAD_LENGTH];
 		s.writeFrame(bigPayload, MAX_PAYLOAD_LENGTH - 1, 1, false);
@@ -90,8 +78,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testAcceptsMaxPayloadWithoutPadding() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		byte[] bigPayload = new byte[MAX_PAYLOAD_LENGTH];
 		s.writeFrame(bigPayload, MAX_PAYLOAD_LENGTH, 0, false);
@@ -103,17 +90,14 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testWriteUnpaddedNonFinalFrameWithTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, payloadLength, 0, false);
 
 		// Expect the tag, stream header, frame header, payload and MAC
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
 		expected.write(tag);
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 		byte[] expectedFrameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -129,17 +113,14 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testWriteUnpaddedFinalFrameWithTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, payloadLength, 0, true);
 
 		// Expect the tag, stream header, frame header, payload and MAC
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
 		expected.write(tag);
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 		byte[] expectedFrameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -155,16 +136,13 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testWriteUnpaddedNonFinalFrameWithoutTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, null, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, null, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, payloadLength, 0, false);
 
 		// Expect the stream header, frame header, payload and MAC
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 		byte[] expectedFrameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -180,16 +158,13 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testWriteUnpaddedFinalFrameWithoutTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, null, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, null, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, payloadLength, 0, true);
 
 		// Expect the stream header, frame header, payload and MAC
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 		byte[] expectedFrameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -205,17 +180,14 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testWritePaddedNonFinalFrameWithTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, payloadLength, paddingLength, false);
 
 		// Expect the tag, stream header, frame header, payload, padding and MAC
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
 		expected.write(tag);
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 		byte[] expectedFrameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -233,17 +205,14 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testWritePaddedFinalFrameWithTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, payloadLength, paddingLength, true);
 
 		// Expect the tag, stream header, frame header, payload, padding and MAC
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
 		expected.write(tag);
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 		byte[] expectedFrameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -261,16 +230,13 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testWritePaddedNonFinalFrameWithoutTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, null, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, null, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, payloadLength, paddingLength, false);
 
 		// Expect the stream header, frame header, payload, padding and MAC
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 		byte[] expectedFrameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -288,16 +254,13 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testWritePaddedFinalFrameWithoutTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, null, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, null, streamHeaderIv, streamHeaderKey, frameKey);
 
 		s.writeFrame(payload, payloadLength, paddingLength, true);
 
 		// Expect the stream header, frame header, payload, padding and MAC
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 		byte[] expectedFrameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -315,8 +278,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testWriteTwoFramesWithTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 		int payloadLength1 = 345, paddingLength1 = 456;
 		byte[] payload1 = TestUtils.getRandomBytes(payloadLength1);
 
@@ -327,9 +289,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 		// MAC, second frame header, payload, padding, MAC
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
 		expected.write(tag);
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 		byte[] expectedFrameHeader = new byte[FRAME_HEADER_LENGTH];
@@ -355,8 +315,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 			throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		// Flush the stream once
 		s.flush();
@@ -364,9 +323,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 		// Expect the tag and stream header
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
 		expected.write(tag);
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 
@@ -378,8 +335,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 			throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, tag, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
 
 		// Flush the stream twice
 		s.flush();
@@ -388,9 +344,7 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 		// Expect the tag and stream header
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
 		expected.write(tag);
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 
@@ -401,17 +355,14 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 	public void testFlushDoesNotWriteTagIfNull() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
-				streamNumber, null, streamHeaderNonce, streamHeaderKey,
-				frameKey);
+				streamNumber, null, streamHeaderIv, streamHeaderKey, frameKey);
 
 		// Flush the stream once
 		s.flush();
 
 		// Expect the stream header
 		ByteArrayOutputStream expected = new ByteArrayOutputStream();
-		expected.write(streamHeaderNonce);
-		expected.write(protocolVersionBytes);
-		expected.write(streamNumberBytes);
+		expected.write(streamHeaderIv);
 		expected.write(frameKey.getBytes());
 		expected.write(new byte[MAC_LENGTH]);
 

bramble-core/src/test/java/org/briarproject/bramble/crypto/TagEncodingTest.java

@@ -1,59 +0,0 @@
-package org.briarproject.bramble.crypto;
-
-import org.briarproject.bramble.api.Bytes;
-import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSecureRandomProvider;
-import org.briarproject.bramble.test.TestUtils;
-import org.junit.Test;
-
-import java.util.HashSet;
-import java.util.Set;
-
-import static junit.framework.TestCase.assertTrue;
-import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
-import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
-
-public class TagEncodingTest extends BrambleTestCase {
-
-	private final CryptoComponent crypto;
-	private final SecretKey tagKey;
-	private final long streamNumber = 1234567890;
-
-	public TagEncodingTest() {
-		crypto = new CryptoComponentImpl(new TestSecureRandomProvider());
-		tagKey = TestUtils.getSecretKey();
-	}
-
-	@Test
-	public void testKeyAffectsTag() throws Exception {
-		Set<Bytes> set = new HashSet<Bytes>();
-		for (int i = 0; i < 100; i++) {
-			byte[] tag = new byte[TAG_LENGTH];
-			SecretKey tagKey = TestUtils.getSecretKey();
-			crypto.encodeTag(tag, tagKey, PROTOCOL_VERSION, streamNumber);
-			assertTrue(set.add(new Bytes(tag)));
-		}
-	}
-
-	@Test
-	public void testProtocolVersionAffectsTag() throws Exception {
-		Set<Bytes> set = new HashSet<Bytes>();
-		for (int i = 0; i < 100; i++) {
-			byte[] tag = new byte[TAG_LENGTH];
-			crypto.encodeTag(tag, tagKey, PROTOCOL_VERSION + i, streamNumber);
-			assertTrue(set.add(new Bytes(tag)));
-		}
-	}
-
-	@Test
-	public void testStreamNumberAffectsTag() throws Exception {
-		Set<Bytes> set = new HashSet<Bytes>();
-		for (int i = 0; i < 100; i++) {
-			byte[] tag = new byte[TAG_LENGTH];
-			crypto.encodeTag(tag, tagKey, PROTOCOL_VERSION, streamNumber + i);
-			assertTrue(set.add(new Bytes(tag)));
-		}
-	}
-}

bramble-core/src/test/java/org/briarproject/bramble/data/BdfReaderImplTest.java

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.data.BdfDictionary;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.TestUtils;
 import org.briarproject.bramble.util.StringUtils;
 import org.junit.Test;
 
@@ -158,7 +159,7 @@ public class BdfReaderImplTest extends BrambleTestCase {
 
 	@Test
 	public void testReadString8() throws Exception {
-		String longest = StringUtils.getRandomString(Byte.MAX_VALUE);
+		String longest = TestUtils.getRandomString(Byte.MAX_VALUE);
 		String longHex = StringUtils.toHexString(longest.getBytes("UTF-8"));
 		// "foo", the empty string, and 127 random letters
 		setContents("41" + "03" + "666F6F" + "41" + "00" +
@@ -180,7 +181,7 @@ public class BdfReaderImplTest extends BrambleTestCase {
 
 	@Test
 	public void testSkipString8() throws Exception {
-		String longest = StringUtils.getRandomString(Byte.MAX_VALUE);
+		String longest = TestUtils.getRandomString(Byte.MAX_VALUE);
 		String longHex = StringUtils.toHexString(longest.getBytes("UTF-8"));
 		// "foo", the empty string, and 127 random letters
 		setContents("41" + "03" + "666F6F" + "41" + "00" +
@@ -193,9 +194,9 @@ public class BdfReaderImplTest extends BrambleTestCase {
 
 	@Test
 	public void testReadString16() throws Exception {
-		String shortest = StringUtils.getRandomString(Byte.MAX_VALUE + 1);
+		String shortest = TestUtils.getRandomString(Byte.MAX_VALUE + 1);
 		String shortHex = StringUtils.toHexString(shortest.getBytes("UTF-8"));
-		String longest = StringUtils.getRandomString(Short.MAX_VALUE);
+		String longest = TestUtils.getRandomString(Short.MAX_VALUE);
 		String longHex = StringUtils.toHexString(longest.getBytes("UTF-8"));
 		// 128 random letters and 2^15 -1 random letters
 		setContents("42" + "0080" + shortHex + "42" + "7FFF" + longHex);
@@ -206,7 +207,7 @@ public class BdfReaderImplTest extends BrambleTestCase {
 
 	@Test(expected = FormatException.class)
 	public void testReadString16ChecksMaxLength() throws Exception {
-		String shortest = StringUtils.getRandomString(Byte.MAX_VALUE + 1);
+		String shortest = TestUtils.getRandomString(Byte.MAX_VALUE + 1);
 		String shortHex = StringUtils.toHexString(shortest.getBytes("UTF-8"));
 		// 128 random letters, twice
 		setContents("42" + "0080" + shortHex + "42" + "0080" + shortHex);
@@ -217,9 +218,9 @@ public class BdfReaderImplTest extends BrambleTestCase {
 
 	@Test
 	public void testSkipString16() throws Exception {
-		String shortest = StringUtils.getRandomString(Byte.MAX_VALUE + 1);
+		String shortest = TestUtils.getRandomString(Byte.MAX_VALUE + 1);
 		String shortHex = StringUtils.toHexString(shortest.getBytes("UTF-8"));
-		String longest = StringUtils.getRandomString(Short.MAX_VALUE);
+		String longest = TestUtils.getRandomString(Short.MAX_VALUE);
 		String longHex = StringUtils.toHexString(longest.getBytes("UTF-8"));
 		// 128 random letters and 2^15 - 1 random letters
 		setContents("42" + "0080" + shortHex + "42" + "7FFF" + longHex);
@@ -230,7 +231,7 @@ public class BdfReaderImplTest extends BrambleTestCase {
 
 	@Test
 	public void testReadString32() throws Exception {
-		String shortest = StringUtils.getRandomString(Short.MAX_VALUE + 1);
+		String shortest = TestUtils.getRandomString(Short.MAX_VALUE + 1);
 		String shortHex = StringUtils.toHexString(shortest.getBytes("UTF-8"));
 		// 2^15 random letters
 		setContents("44" + "00008000" + shortHex);
@@ -240,7 +241,7 @@ public class BdfReaderImplTest extends BrambleTestCase {
 
 	@Test(expected = FormatException.class)
 	public void testReadString32ChecksMaxLength() throws Exception {
-		String shortest = StringUtils.getRandomString(Short.MAX_VALUE + 1);
+		String shortest = TestUtils.getRandomString(Short.MAX_VALUE + 1);
 		String shortHex = StringUtils.toHexString(shortest.getBytes("UTF-8"));
 		// 2^15 random letters, twice
 		setContents("44" + "00008000" + shortHex +
@@ -252,7 +253,7 @@ public class BdfReaderImplTest extends BrambleTestCase {
 
 	@Test
 	public void testSkipString32() throws Exception {
-		String shortest = StringUtils.getRandomString(Short.MAX_VALUE + 1);
+		String shortest = TestUtils.getRandomString(Short.MAX_VALUE + 1);
 		String shortHex = StringUtils.toHexString(shortest.getBytes("UTF-8"));
 		// 2^15 random letters, twice
 		setContents("44" + "00008000" + shortHex +

bramble-core/src/test/java/org/briarproject/bramble/data/BdfWriterImplTest.java

@@ -81,7 +81,7 @@ public class BdfWriterImplTest extends BrambleTestCase {
 
 	@Test
 	public void testWriteString8() throws IOException {
-		String longest = StringUtils.getRandomString(Byte.MAX_VALUE);
+		String longest = TestUtils.getRandomString(Byte.MAX_VALUE);
 		String longHex = StringUtils.toHexString(longest.getBytes("UTF-8"));
 		w.writeString("foo bar baz bam ");
 		w.writeString(longest);
@@ -93,9 +93,9 @@ public class BdfWriterImplTest extends BrambleTestCase {
 
 	@Test
 	public void testWriteString16() throws IOException {
-		String shortest = StringUtils.getRandomString(Byte.MAX_VALUE + 1);
+		String shortest = TestUtils.getRandomString(Byte.MAX_VALUE + 1);
 		String shortHex = StringUtils.toHexString(shortest.getBytes("UTF-8"));
-		String longest = StringUtils.getRandomString(Short.MAX_VALUE);
+		String longest = TestUtils.getRandomString(Short.MAX_VALUE);
 		String longHex = StringUtils.toHexString(longest.getBytes("UTF-8"));
 		w.writeString(shortest);
 		w.writeString(longest);
@@ -106,7 +106,7 @@ public class BdfWriterImplTest extends BrambleTestCase {
 
 	@Test
 	public void testWriteString32() throws IOException {
-		String shortest = StringUtils.getRandomString(Short.MAX_VALUE + 1);
+		String shortest = TestUtils.getRandomString(Short.MAX_VALUE + 1);
 		String shortHex = StringUtils.toHexString(shortest.getBytes("UTF-8"));
 		w.writeString(shortest);
 		// STRING_32 tag, length 2^15, UTF-8 bytes

bramble-core/src/test/java/org/briarproject/bramble/db/BasicH2Test.java

@@ -2,7 +2,6 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -49,8 +48,8 @@ public class BasicH2Test extends BrambleTestCase {
 		createTable(connection);
 		// Generate an ID and two names
 		byte[] id = TestUtils.getRandomId();
-		String oldName = StringUtils.getRandomString(50);
-		String newName = StringUtils.getRandomString(50);
+		String oldName = TestUtils.getRandomString(50);
+		String newName = TestUtils.getRandomString(50);
 		// Insert the ID and old name into the table
 		insertRow(id, oldName);
 		// Check that the old name can be retrieved using the ID
@@ -79,8 +78,8 @@ public class BasicH2Test extends BrambleTestCase {
 		String[] newNames = new String[BATCH_SIZE];
 		for (int i = 0; i < BATCH_SIZE; i++) {
 			ids[i] = TestUtils.getRandomId();
-			oldNames[i] = StringUtils.getRandomString(50);
-			newNames[i] = StringUtils.getRandomString(50);
+			oldNames[i] = TestUtils.getRandomString(50);
+			newNames[i] = TestUtils.getRandomString(50);
 		}
 		// Insert the IDs and old names into the table as a batch
 		insertBatch(ids, oldNames);

bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseComponentImplTest.java

@@ -49,7 +49,6 @@ import org.briarproject.bramble.api.transport.OutgoingKeys;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.jmock.Expectations;
 import org.jmock.Mockery;
 import org.junit.Test;
@@ -95,7 +94,7 @@ public class DatabaseComponentImplTest extends BrambleTestCase {
 	private final Contact contact;
 
 	public DatabaseComponentImplTest() {
-		clientId = new ClientId(StringUtils.getRandomString(5));
+		clientId = new ClientId(TestUtils.getRandomString(5));
 		groupId = new GroupId(TestUtils.getRandomId());
 		byte[] descriptor = new byte[MAX_GROUP_DESCRIPTOR_LENGTH];
 		group = new Group(groupId, clientId, descriptor);

bramble-core/src/test/java/org/briarproject/bramble/db/H2DatabaseTest.java

@@ -24,7 +24,6 @@ import org.briarproject.bramble.system.SystemClock;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestDatabaseConfig;
 import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -85,7 +84,7 @@ public class H2DatabaseTest extends BrambleTestCase {
 
 	public H2DatabaseTest() throws Exception {
 		groupId = new GroupId(TestUtils.getRandomId());
-		clientId = new ClientId(StringUtils.getRandomString(5));
+		clientId = new ClientId(TestUtils.getRandomString(5));
 		byte[] descriptor = new byte[MAX_GROUP_DESCRIPTOR_LENGTH];
 		group = new Group(groupId, clientId, descriptor);
 		AuthorId authorId = new AuthorId(TestUtils.getRandomId());

bramble-core/src/test/java/org/briarproject/bramble/identity/IdentityManagerImplTest.java

@@ -11,7 +11,6 @@ import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.jmock.Expectations;
 import org.junit.Test;
 
@@ -32,9 +31,8 @@ public class IdentityManagerImplTest extends BrambleMockTestCase {
 	private final Transaction txn = new Transaction(null, false);
 	private final LocalAuthor localAuthor =
 			new LocalAuthor(new AuthorId(TestUtils.getRandomId()),
-					StringUtils.getRandomString(8),
-					TestUtils.getRandomBytes(42), TestUtils.getRandomBytes(42),
-					0);
+					TestUtils.getRandomString(8), TestUtils.getRandomBytes(42),
+					TestUtils.getRandomBytes(42), 0);
 	private final Collection<LocalAuthor> localAuthors =
 			Collections.singletonList(localAuthor);
 
@@ -95,7 +93,7 @@ public class IdentityManagerImplTest extends BrambleMockTestCase {
 		assertEquals(UNKNOWN, identityManager.getAuthorStatus(authorId));
 
 		// add one unverified contact
-		Author author = new Author(authorId, StringUtils.getRandomString(8),
+		Author author = new Author(authorId, TestUtils.getRandomString(8),
 				TestUtils.getRandomBytes(42));
 		Contact contact =
 				new Contact(new ContactId(1), author, localAuthor.getId(),

bramble-core/src/test/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java

@@ -311,11 +311,6 @@ public class LanTcpPluginTest extends BrambleTestCase {
 			return remote;
 		}
 
-		@Override
-		public TransportProperties getRemoteProperties(ContactId c) {
-			return remote.get(c);
-		}
-
 		@Override
 		public void mergeSettings(Settings s) {
 		}

bramble-core/src/test/java/org/briarproject/bramble/properties/TransportPropertyValidatorTest.java

@@ -14,7 +14,6 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.jmock.Mockery;
 import org.junit.Test;
 
@@ -37,7 +36,7 @@ public class TransportPropertyValidatorTest extends BrambleTestCase {
 		bdfDictionary = new BdfDictionary();
 
 		GroupId groupId = new GroupId(TestUtils.getRandomId());
-		ClientId clientId = new ClientId(StringUtils.getRandomString(5));
+		ClientId clientId = new ClientId(TestUtils.getRandomString(5));
 		byte[] descriptor = TestUtils.getRandomBytes(12);
 		group = new Group(groupId, clientId, descriptor);
 
@@ -86,7 +85,7 @@ public class TransportPropertyValidatorTest extends BrambleTestCase {
 	public void testValidateLongTransportId() throws IOException {
 
 		String wrongTransportIdString =
-				StringUtils.getRandomString(MAX_TRANSPORT_ID_LENGTH + 1);
+				TestUtils.getRandomString(MAX_TRANSPORT_ID_LENGTH + 1);
 		BdfList body = BdfList.of(wrongTransportIdString, 4, bdfDictionary);
 		tpv.validateMessage(message, group, body);
 	}

bramble-core/src/test/java/org/briarproject/bramble/sync/SyncIntegrationTest.java

@@ -22,7 +22,6 @@ import org.briarproject.bramble.api.transport.StreamReaderFactory;
 import org.briarproject.bramble.api.transport.StreamWriterFactory;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.junit.Test;
 
 import java.io.ByteArrayInputStream;
@@ -35,7 +34,6 @@ import java.util.Collection;
 import javax.inject.Inject;
 
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_GROUP_DESCRIPTOR_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
@@ -79,7 +77,7 @@ public class SyncIntegrationTest extends BrambleTestCase {
 		headerKey = TestUtils.getSecretKey();
 		streamNumber = 123;
 		// Create a group
-		ClientId clientId = new ClientId(StringUtils.getRandomString(5));
+		ClientId clientId = new ClientId(TestUtils.getRandomString(5));
 		byte[] descriptor = new byte[MAX_GROUP_DESCRIPTOR_LENGTH];
 		Group group = groupFactory.createGroup(clientId, descriptor);
 		// Add two messages to the group
@@ -117,7 +115,7 @@ public class SyncIntegrationTest extends BrambleTestCase {
 	private void read(byte[] connectionData) throws Exception {
 		// Calculate the expected tag
 		byte[] expectedTag = new byte[TAG_LENGTH];
-		crypto.encodeTag(expectedTag, tagKey, PROTOCOL_VERSION, streamNumber);
+		crypto.encodeTag(expectedTag, tagKey, streamNumber);
 
 		// Read the tag
 		InputStream in = new ByteArrayInputStream(connectionData);

bramble-core/src/test/java/org/briarproject/bramble/sync/ValidationManagerImplTest.java

@@ -23,7 +23,6 @@ import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.ImmediateExecutor;
 import org.briarproject.bramble.test.TestUtils;
 import org.briarproject.bramble.util.ByteUtils;
-import org.briarproject.bramble.util.StringUtils;
 import org.jmock.Expectations;
 import org.junit.Before;
 import org.junit.Test;
@@ -52,7 +51,7 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 	private final Executor dbExecutor = new ImmediateExecutor();
 	private final Executor validationExecutor = new ImmediateExecutor();
 	private final ClientId clientId =
-			new ClientId(StringUtils.getRandomString(5));
+			new ClientId(TestUtils.getRandomString(5));
 	private final MessageId messageId = new MessageId(TestUtils.getRandomId());
 	private final MessageId messageId1 = new MessageId(TestUtils.getRandomId());
 	private final MessageId messageId2 = new MessageId(TestUtils.getRandomId());

bramble-core/src/test/java/org/briarproject/bramble/test/ValidatorTestCase.java

@@ -9,7 +9,6 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.util.StringUtils;
 
 public abstract class ValidatorTestCase extends BrambleMockTestCase {
 
@@ -29,7 +28,7 @@ public abstract class ValidatorTestCase extends BrambleMockTestCase {
 	protected final Message message =
 			new Message(messageId, groupId, timestamp, raw);
 	protected final ClientId clientId =
-			new ClientId(StringUtils.getRandomString(123));
+			new ClientId(TestUtils.getRandomString(123));
 	protected final byte[] descriptor = TestUtils.getRandomBytes(123);
 	protected final Group group = new Group(groupId, clientId, descriptor);
 

bramble-core/src/test/java/org/briarproject/bramble/transport/TransportKeyManagerImplTest.java

@@ -33,7 +33,6 @@ import java.util.concurrent.ScheduledExecutorService;
 
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 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.REORDERING_WINDOW_SIZE;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
 import static org.briarproject.bramble.util.ByteUtils.MAX_32_BIT_UNSIGNED;
@@ -87,7 +86,7 @@ public class TransportKeyManagerImplTest extends BrambleTestCase {
 			// Encode the tags (3 sets per contact)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(6).of(crypto).encodeTag(with(any(byte[].class)),
-						with(tagKey), with(PROTOCOL_VERSION), with(i));
+						with(tagKey), with(i));
 				will(new EncodeTagAction());
 			}
 			// Save the keys that were rotated
@@ -134,7 +133,7 @@ public class TransportKeyManagerImplTest extends BrambleTestCase {
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(crypto).encodeTag(with(any(byte[].class)),
-						with(tagKey), with(PROTOCOL_VERSION), with(i));
+						with(tagKey), with(i));
 				will(new EncodeTagAction());
 			}
 			// Save the keys
@@ -200,7 +199,7 @@ public class TransportKeyManagerImplTest extends BrambleTestCase {
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(crypto).encodeTag(with(any(byte[].class)),
-						with(tagKey), with(PROTOCOL_VERSION), with(i));
+						with(tagKey), with(i));
 				will(new EncodeTagAction());
 			}
 			// Rotate the transport keys (the keys are unaffected)
@@ -248,7 +247,7 @@ public class TransportKeyManagerImplTest extends BrambleTestCase {
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(crypto).encodeTag(with(any(byte[].class)),
-						with(tagKey), with(PROTOCOL_VERSION), with(i));
+						with(tagKey), with(i));
 				will(new EncodeTagAction());
 			}
 			// Rotate the transport keys (the keys are unaffected)
@@ -307,7 +306,7 @@ public class TransportKeyManagerImplTest extends BrambleTestCase {
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(crypto).encodeTag(with(any(byte[].class)),
-						with(tagKey), with(PROTOCOL_VERSION), with(i));
+						with(tagKey), with(i));
 				will(new EncodeTagAction());
 			}
 			// Rotate the transport keys (the keys are unaffected)
@@ -356,7 +355,7 @@ public class TransportKeyManagerImplTest extends BrambleTestCase {
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(crypto).encodeTag(with(any(byte[].class)),
-						with(tagKey), with(PROTOCOL_VERSION), with(i));
+						with(tagKey), with(i));
 				will(new EncodeTagAction(tags));
 			}
 			// Rotate the transport keys (the keys are unaffected)
@@ -366,8 +365,7 @@ public class TransportKeyManagerImplTest extends BrambleTestCase {
 			oneOf(db).addTransportKeys(txn, contactId, transportKeys);
 			// Encode a new tag after sliding the window
 			oneOf(crypto).encodeTag(with(any(byte[].class)),
-					with(tagKey), with(PROTOCOL_VERSION),
-					with((long) REORDERING_WINDOW_SIZE));
+					with(tagKey), with((long) REORDERING_WINDOW_SIZE));
 			will(new EncodeTagAction(tags));
 			// Save the reordering window (previous rotation period, base 1)
 			oneOf(db).setReorderingWindow(txn, contactId, transportId, 999,
@@ -430,7 +428,7 @@ public class TransportKeyManagerImplTest extends BrambleTestCase {
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(crypto).encodeTag(with(any(byte[].class)),
-						with(tagKey), with(PROTOCOL_VERSION), with(i));
+						with(tagKey), with(i));
 				will(new EncodeTagAction());
 			}
 			// Schedule key rotation at the start of the next rotation period
@@ -452,7 +450,7 @@ public class TransportKeyManagerImplTest extends BrambleTestCase {
 			// Encode the tags (3 sets)
 			for (long i = 0; i < REORDERING_WINDOW_SIZE; i++) {
 				exactly(3).of(crypto).encodeTag(with(any(byte[].class)),
-						with(tagKey), with(PROTOCOL_VERSION), with(i));
+						with(tagKey), with(i));
 				will(new EncodeTagAction());
 			}
 			// Save the keys that were rotated

bramble-j2se/build.gradle

@@ -7,19 +7,10 @@ apply plugin: 'witness'
 dependencies {
 	compile project(':bramble-core')
 	compile fileTree(dir: 'libs', include: '*.jar')
-	compile 'net.java.dev.jna:jna:4.4.0'
-	compile 'net.java.dev.jna:jna-platform:4.4.0'
 
 	testCompile project(path: ':bramble-core', configuration: 'testOutput')
 }
 
-dependencyVerification {
-	verify = [
-			'net.java.dev.jna:jna:c4dadeeecaa90c8847902082aee5eb107fcf59c5d0e63a17fcaf273c0e2d2bd1',
-			'net.java.dev.jna:jna-platform:e9dda9e884fc107eb6367710540789a12dfa8ad28be9326b22ca6e352e325499',
-	]
-}
-
 tasks.withType(Test) {
 	systemProperty 'java.library.path', 'libs'
 }

bramble-j2se/src/main/java/org/briarproject/bramble/plugin/bluetooth/BluetoothPlugin.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.plugin.bluetooth;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
@@ -18,23 +19,33 @@ import org.briarproject.bramble.util.OsUtils;
 import org.briarproject.bramble.util.StringUtils;
 
 import java.io.IOException;
+import java.io.InputStream;
 import java.security.SecureRandom;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.UUID;
 import java.util.concurrent.Callable;
+import java.util.concurrent.CompletionService;
+import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorCompletionService;
+import java.util.concurrent.Future;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.bluetooth.BluetoothStateException;
+import javax.bluetooth.DiscoveryAgent;
 import javax.bluetooth.LocalDevice;
 import javax.microedition.io.Connector;
 import javax.microedition.io.StreamConnection;
 import javax.microedition.io.StreamConnectionNotifier;
 
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static javax.bluetooth.DiscoveryAgent.GIAC;
@@ -56,6 +67,7 @@ class BluetoothPlugin implements DuplexPlugin {
 	private final Backoff backoff;
 	private final DuplexPluginCallback callback;
 	private final int maxLatency;
+	private final Semaphore discoverySemaphore = new Semaphore(1);
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	private volatile boolean running = false;
@@ -249,7 +261,8 @@ class BluetoothPlugin implements DuplexPlugin {
 	@Override
 	public DuplexTransportConnection createConnection(ContactId c) {
 		if (!running) return null;
-		TransportProperties p = callback.getRemoteProperties(c);
+		TransportProperties p = callback.getRemoteProperties().get(c);
+		if (p == null) return null;
 		String address = p.get(PROP_ADDRESS);
 		if (StringUtils.isNullOrEmpty(address)) return null;
 		String uuid = p.get(PROP_UUID);
@@ -260,6 +273,95 @@ class BluetoothPlugin implements DuplexPlugin {
 		return new BluetoothTransportConnection(this, s);
 	}
 
+	@Override
+	public boolean supportsInvitations() {
+		return true;
+	}
+
+	@Override
+	public DuplexTransportConnection createInvitationConnection(PseudoRandom r,
+			long timeout, boolean alice) {
+		if (!running) return null;
+		// Use the invitation codes to generate the UUID
+		byte[] b = r.nextBytes(UUID_BYTES);
+		String uuid = UUID.nameUUIDFromBytes(b).toString();
+		String url = makeUrl("localhost", uuid);
+		// Make the device discoverable if possible
+		makeDeviceDiscoverable();
+		// Bind a server socket for receiving invitation connections
+		final StreamConnectionNotifier ss;
+		try {
+			ss = (StreamConnectionNotifier) Connector.open(url);
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			return null;
+		}
+		if (!running) {
+			tryToClose(ss);
+			return null;
+		}
+		// Create the background tasks
+		CompletionService<StreamConnection> complete =
+				new ExecutorCompletionService<>(ioExecutor);
+		List<Future<StreamConnection>> futures = new ArrayList<>();
+		if (alice) {
+			// Return the first connected socket
+			futures.add(complete.submit(new ListeningTask(ss)));
+			futures.add(complete.submit(new DiscoveryTask(uuid)));
+		} else {
+			// Return the first socket with readable data
+			futures.add(complete.submit(new ReadableTask(
+					new ListeningTask(ss))));
+			futures.add(complete.submit(new ReadableTask(
+					new DiscoveryTask(uuid))));
+		}
+		StreamConnection chosen = null;
+		try {
+			Future<StreamConnection> f = complete.poll(timeout, MILLISECONDS);
+			if (f == null) return null; // No task completed within the timeout
+			chosen = f.get();
+			return new BluetoothTransportConnection(this, chosen);
+		} catch (InterruptedException e) {
+			LOG.info("Interrupted while exchanging invitations");
+			Thread.currentThread().interrupt();
+			return null;
+		} catch (ExecutionException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			return null;
+		} finally {
+			// Closing the socket will terminate the listener task
+			tryToClose(ss);
+			closeSockets(futures, chosen);
+		}
+	}
+
+	private void closeSockets(final List<Future<StreamConnection>> futures,
+			@Nullable final StreamConnection chosen) {
+		ioExecutor.execute(new Runnable() {
+			@Override
+			public void run() {
+				for (Future<StreamConnection> f : futures) {
+					try {
+						if (f.cancel(true)) {
+							LOG.info("Cancelled task");
+						} else {
+							StreamConnection s = f.get();
+							if (s != null && s != chosen) {
+								LOG.info("Closing unwanted socket");
+								s.close();
+							}
+						}
+					} catch (InterruptedException e) {
+						LOG.info("Interrupted while closing sockets");
+						return;
+					} catch (ExecutionException | IOException e) {
+						if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+					}
+				}
+			}
+		});
+	}
+
 	@Override
 	public boolean supportsKeyAgreement() {
 		return true;
@@ -274,7 +376,7 @@ class BluetoothPlugin implements DuplexPlugin {
 		String url = makeUrl("localhost", uuid);
 		// Make the device discoverable if possible
 		makeDeviceDiscoverable();
-		// Bind a server socket for receiving key agreementconnections
+		// Bind a server socket for receiving invitation connections
 		final StreamConnectionNotifier ss;
 		try {
 			ss = (StreamConnectionNotifier) Connector.open(url);
@@ -329,6 +431,77 @@ class BluetoothPlugin implements DuplexPlugin {
 		}
 	}
 
+	private class DiscoveryTask implements Callable<StreamConnection> {
+
+		private final String uuid;
+
+		private DiscoveryTask(String uuid) {
+			this.uuid = uuid;
+		}
+
+		@Override
+		public StreamConnection call() throws Exception {
+			// Repeat discovery until we connect or get interrupted
+			DiscoveryAgent discoveryAgent = localDevice.getDiscoveryAgent();
+			while (true) {
+				if (!discoverySemaphore.tryAcquire())
+					throw new Exception("Discovery is already in progress");
+				try {
+					InvitationListener listener =
+							new InvitationListener(discoveryAgent, uuid);
+					discoveryAgent.startInquiry(GIAC, listener);
+					String url = listener.waitForUrl();
+					if (url != null) {
+						StreamConnection s = connect(url);
+						if (s != null) {
+							LOG.info("Outgoing connection");
+							return s;
+						}
+					}
+				} finally {
+					discoverySemaphore.release();
+				}
+			}
+		}
+	}
+
+	private static class ListeningTask implements Callable<StreamConnection> {
+
+		private final StreamConnectionNotifier serverSocket;
+
+		private ListeningTask(StreamConnectionNotifier serverSocket) {
+			this.serverSocket = serverSocket;
+		}
+
+		@Override
+		public StreamConnection call() throws Exception {
+			StreamConnection s = serverSocket.acceptAndOpen();
+			LOG.info("Incoming connection");
+			return s;
+		}
+	}
+
+	private static class ReadableTask implements Callable<StreamConnection> {
+
+		private final Callable<StreamConnection> connectionTask;
+
+		private ReadableTask(Callable<StreamConnection> connectionTask) {
+			this.connectionTask = connectionTask;
+		}
+
+		@Override
+		public StreamConnection call() throws Exception {
+			StreamConnection s = connectionTask.call();
+			InputStream in = s.openInputStream();
+			while (in.available() == 0) {
+				LOG.info("Waiting for data");
+				Thread.sleep(1000);
+			}
+			LOG.info("Data available");
+			return s;
+		}
+	}
+
 	private class BluetoothKeyAgreementListener extends KeyAgreementListener {
 
 		private final StreamConnectionNotifier ss;

bramble-j2se/src/main/java/org/briarproject/bramble/plugin/bluetooth/InvitationListener.java

@@ -0,0 +1,109 @@
+package org.briarproject.bramble.plugin.bluetooth;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.TreeSet;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.logging.Logger;
+
+import javax.bluetooth.BluetoothStateException;
+import javax.bluetooth.DataElement;
+import javax.bluetooth.DeviceClass;
+import javax.bluetooth.DiscoveryAgent;
+import javax.bluetooth.DiscoveryListener;
+import javax.bluetooth.RemoteDevice;
+import javax.bluetooth.ServiceRecord;
+import javax.bluetooth.UUID;
+
+import static java.util.logging.Level.WARNING;
+
+class InvitationListener implements DiscoveryListener {
+
+	private static final Logger LOG =
+			Logger.getLogger(InvitationListener.class.getName());
+
+	private final AtomicInteger searches = new AtomicInteger(1);
+	private final CountDownLatch finished = new CountDownLatch(1);
+	private final DiscoveryAgent discoveryAgent;
+	private final String uuid;
+
+	private volatile String url = null;
+
+	InvitationListener(DiscoveryAgent discoveryAgent, String uuid) {
+		this.discoveryAgent = discoveryAgent;
+		this.uuid = uuid;
+	}
+
+	String waitForUrl() throws InterruptedException {
+		finished.await();
+		return url;
+	}
+
+	@Override
+	public void deviceDiscovered(RemoteDevice device, DeviceClass deviceClass) {
+		UUID[] uuids = new UUID[] {new UUID(uuid, false)};
+		// Try to discover the services associated with the UUID
+		try {
+			discoveryAgent.searchServices(null, uuids, device, this);
+			searches.incrementAndGet();
+		} catch (BluetoothStateException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		}
+	}
+
+	@Override
+	public void servicesDiscovered(int transaction, ServiceRecord[] services) {
+		for (ServiceRecord record : services) {
+			// Does this service have a URL?
+			String serviceUrl = record.getConnectionURL(
+					ServiceRecord.NOAUTHENTICATE_NOENCRYPT, false);
+			if (serviceUrl == null) continue;
+			// Does this service have the UUID we're looking for?
+			Collection<String> uuids = new TreeSet<>();
+			findNestedClassIds(record.getAttributeValue(0x1), uuids);
+			for (String u : uuids) {
+				if (uuid.equalsIgnoreCase(u)) {
+					// The UUID matches - store the URL
+					url = serviceUrl;
+					finished.countDown();
+					return;
+				}
+			}
+		}
+	}
+
+	@Override
+	public void inquiryCompleted(int discoveryType) {
+		if (searches.decrementAndGet() == 0) finished.countDown();
+	}
+
+	@Override
+	public void serviceSearchCompleted(int transaction, int response) {
+		if (searches.decrementAndGet() == 0) finished.countDown();
+	}
+
+	// UUIDs are sometimes buried in nested data elements
+	private void findNestedClassIds(Object o, Collection<String> ids) {
+		o = getDataElementValue(o);
+		if (o instanceof Enumeration<?>) {
+			for (Object o1 : Collections.list((Enumeration<?>) o))
+				findNestedClassIds(o1, ids);
+		} else if (o instanceof UUID) {
+			ids.add(o.toString());
+		}
+	}
+
+	private Object getDataElementValue(Object o) {
+		if (o instanceof DataElement) {
+			// Bluecove throws an exception if the type is unknown
+			try {
+				return ((DataElement) o).getValue();
+			} catch (ClassCastException e) {
+				return null;
+			}
+		}
+		return null;
+	}
+}

bramble-j2se/src/main/java/org/briarproject/bramble/plugin/modem/ModemPlugin.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin.modem;
 
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
@@ -145,7 +146,8 @@ class ModemPlugin implements DuplexPlugin, Modem.Callback {
 		String fromIso = callback.getLocalProperties().get("iso3166");
 		if (StringUtils.isNullOrEmpty(fromIso)) return null;
 		// Get the ISO 3166 code for the callee's country
-		TransportProperties properties = callback.getRemoteProperties(c);
+		TransportProperties properties = callback.getRemoteProperties().get(c);
+		if (properties == null) return null;
 		String toIso = properties.get("iso3166");
 		if (StringUtils.isNullOrEmpty(toIso)) return null;
 		// Get the callee's phone number
@@ -165,6 +167,17 @@ class ModemPlugin implements DuplexPlugin, Modem.Callback {
 		return new ModemTransportConnection();
 	}
 
+	@Override
+	public boolean supportsInvitations() {
+		return false;
+	}
+
+	@Override
+	public DuplexTransportConnection createInvitationConnection(PseudoRandom r,
+			long timeout, boolean alice) {
+		throw new UnsupportedOperationException();
+	}
+
 	@Override
 	public boolean supportsKeyAgreement() {
 		return false;

bramble-j2se/src/test/java/org/briarproject/bramble/plugin/modem/ModemPluginTest.java

@@ -9,6 +9,8 @@ import org.jmock.Mockery;
 import org.junit.Test;
 
 import java.io.IOException;
+import java.util.Collections;
+import java.util.Map;
 
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
@@ -63,10 +65,12 @@ public class ModemPluginTest extends BrambleTestCase {
 		final Modem modem = context.mock(Modem.class);
 		final TransportProperties local = new TransportProperties();
 		local.put("iso3166", ISO_1336);
-		final TransportProperties remote = new TransportProperties();
-		remote.put("iso3166", ISO_1336);
-		remote.put("number", NUMBER);
-		final ContactId contactId = new ContactId(234);
+		TransportProperties p = new TransportProperties();
+		p.put("iso3166", ISO_1336);
+		p.put("number", NUMBER);
+		ContactId contactId = new ContactId(234);
+		final Map<ContactId, TransportProperties> remote =
+				Collections.singletonMap(contactId, p);
 		context.checking(new Expectations() {{
 			// start()
 			oneOf(serialPortList).getPortNames();
@@ -78,7 +82,7 @@ public class ModemPluginTest extends BrambleTestCase {
 			// createConnection()
 			oneOf(callback).getLocalProperties();
 			will(returnValue(local));
-			oneOf(callback).getRemoteProperties(contactId);
+			oneOf(callback).getRemoteProperties();
 			will(returnValue(remote));
 			oneOf(modem).dial(NUMBER);
 			will(returnValue(true));
@@ -102,10 +106,12 @@ public class ModemPluginTest extends BrambleTestCase {
 		final Modem modem = context.mock(Modem.class);
 		final TransportProperties local = new TransportProperties();
 		local.put("iso3166", ISO_1336);
-		final TransportProperties remote = new TransportProperties();
-		remote.put("iso3166", ISO_1336);
-		remote.put("number", NUMBER);
-		final ContactId contactId = new ContactId(234);
+		TransportProperties p = new TransportProperties();
+		p.put("iso3166", ISO_1336);
+		p.put("number", NUMBER);
+		ContactId contactId = new ContactId(234);
+		final Map<ContactId, TransportProperties> remote =
+				Collections.singletonMap(contactId, p);
 		context.checking(new Expectations() {{
 			// start()
 			oneOf(serialPortList).getPortNames();
@@ -117,7 +123,7 @@ public class ModemPluginTest extends BrambleTestCase {
 			// createConnection()
 			oneOf(callback).getLocalProperties();
 			will(returnValue(local));
-			oneOf(callback).getRemoteProperties(contactId);
+			oneOf(callback).getRemoteProperties();
 			will(returnValue(remote));
 			oneOf(modem).dial(NUMBER);
 			will(returnValue(false));
@@ -141,10 +147,12 @@ public class ModemPluginTest extends BrambleTestCase {
 		final Modem modem = context.mock(Modem.class);
 		final TransportProperties local = new TransportProperties();
 		local.put("iso3166", ISO_1336);
-		final TransportProperties remote = new TransportProperties();
-		remote.put("iso3166", ISO_1336);
-		remote.put("number", NUMBER);
-		final ContactId contactId = new ContactId(234);
+		TransportProperties p = new TransportProperties();
+		p.put("iso3166", ISO_1336);
+		p.put("number", NUMBER);
+		ContactId contactId = new ContactId(234);
+		final Map<ContactId, TransportProperties> remote =
+				Collections.singletonMap(contactId, p);
 		context.checking(new Expectations() {{
 			// start()
 			oneOf(serialPortList).getPortNames();
@@ -156,7 +164,7 @@ public class ModemPluginTest extends BrambleTestCase {
 			// createConnection()
 			oneOf(callback).getLocalProperties();
 			will(returnValue(local));
-			oneOf(callback).getRemoteProperties(contactId);
+			oneOf(callback).getRemoteProperties();
 			will(returnValue(remote));
 			oneOf(modem).dial(NUMBER);
 			will(throwException(new IOException()));

briar-android/.tx/config

@@ -1,6 +1,6 @@
 [main]
 host = https://www.transifex.com
-lang_map = pt_BR: pt-rBR, fr_FR: fr, nb_NO: nb, zh-Hans: zh-rCN
+lang_map = pt_BR: pt-rBR, fr_FR: fr
 
 [briar.stringsxml-5]
 file_filter = src/main/res/values-<lang>/strings.xml

briar-android/build.gradle

@@ -5,10 +5,13 @@ dependencies {
 	def supportVersion = '23.2.1'
 	compile project(':briar-core')
 	compile project(':bramble-android')
+	compile fileTree(dir: 'libs', include: '*.jar')
+
 	compile "com.android.support:support-v4:$supportVersion"
 	compile("com.android.support:appcompat-v7:$supportVersion") {
 		exclude module: 'support-v4'
 	}
+
 	compile("com.android.support:preference-v14:$supportVersion") {
 		exclude module: 'support-v4'
 	}
@@ -17,7 +20,7 @@ dependencies {
 		exclude module: 'recyclerview-v7'
 	}
 	compile "com.android.support:cardview-v7:$supportVersion"
-	compile "com.android.support:support-annotations:$supportVersion"
+	compile 'com.android.support:support-annotations:23.4.0'
 	compile('ch.acra:acra:4.8.5') {
 		exclude module: 'support-v4'
 		exclude module: 'support-annotations'
@@ -25,16 +28,15 @@ dependencies {
 	compile 'info.guardianproject.panic:panic:0.5'
 	compile 'info.guardianproject.trustedintents:trustedintents:0.2'
 	compile 'de.hdodenhof:circleimageview:2.1.0'
-	compile 'com.google.zxing:core:3.3.0'
-	compile 'com.jpardogo.materialtabstrip:library:1.1.0'
-	compile 'com.github.bumptech.glide:glide:3.8.0'
-	compile 'uk.co.samuelwall:material-tap-target-prompt:1.9.2'
-
+	compile 'com.google.zxing:core:3.2.1'
 	provided 'javax.annotation:jsr250-api:1.0'
+	compile 'com.jpardogo.materialtabstrip:library:1.1.0'
+	compile 'com.github.bumptech.glide:glide:3.7.0'
+	compile 'uk.co.samuelwall:material-tap-target-prompt:1.3.0'
 
 	testCompile project(path: ':bramble-core', configuration: 'testOutput')
 	testCompile 'org.robolectric:robolectric:3.0'
-	testCompile 'org.mockito:mockito-core:2.8.9'
+	testCompile 'org.mockito:mockito-core:1.10.19'
 }
 
 dependencyVerification {
@@ -43,18 +45,20 @@ dependencyVerification {
 			'info.guardianproject.panic:panic:a7ed9439826db2e9901649892cf9afbe76f00991b768d8f4c26332d7c9406cb2',
 			'info.guardianproject.trustedintents:trustedintents:6221456d8821a8d974c2acf86306900237cf6afaaa94a4c9c44e161350f80f3e',
 			'de.hdodenhof:circleimageview:bcbc588e19e6dcf8c120b1957776bfe229efba5d2fbe5da7156372eeacf65503',
-			'com.google.zxing:core:bba7724e02a997cec38213af77133ee8e24b0d5cf5fa7ecbc16a4fa93f11ee0d',
-			'com.jpardogo.materialtabstrip:library:24d19232b319f8c73e25793432357919a7ed972186f57a3b2c9093ea74ad8311',
-			'com.github.bumptech.glide:glide:750d9e7b940dc0ee48f8680623b55d46e14e8727acc922d7b156e57e7c549655',
-			'uk.co.samuelwall:material-tap-target-prompt:5d4951124366bc5c52e57beaa294db7611f0aa2a8d80e0163e1383e1966ba5b2',
+			'com.google.zxing:core:b4d82452e7a6bf6ec2698904b332431717ed8f9a850224f295aec89de80f2259',
+			'com.android.support:support-v4:81ce890f26d35c75ad17d0f998a7e3230330c3b41e0b629566bc744bee89e448',
 			'com.android.support:appcompat-v7:00f9d93acacd6731f309724054bf51492814b4b2869f16d7d5c0038dcb8c9a0d',
 			'com.android.support:preference-v14:44881bb46094e86d0bc2426f205419674a5b4eb514b44b5a4659b5de29f71eb7',
 			'com.android.support:design:003e0c0bea0a6891f8b2bc43f20ae7af2a49a17363e5bb10df5ee0bae12fa686',
-			'com.android.support:cardview-v7:4595f1c4a28cfa083b6c0920ad4d49e1c2ca4b8302a955e548f68eb63b74931b',
+			'com.android.support:support-annotations:e91a88dd0c5e99069b7f09d4a46b5e06f1e9c4c72fc0a8e987e25d86af480f01',
 			'com.android.support:animated-vector-drawable:06d1963b85aa917099d7757e6a7b3e4dc06889413dc747f625ae8683606db3a1',
 			'com.android.support:support-vector-drawable:799bafe4c3de812386f0b291f744d5d6876452722dd40189b9ab87dbbf594ea1',
 			'com.android.support:recyclerview-v7:44040a888e23e0c93162a3377cfe06751080e3c22d369ab0d4301ef60d63b0fe',
 			'com.android.support:preference-v7:775101bd07bd052e455761c5c5d9523d7ad59f2f320e3e8cbde241fd6b1d6025',
+			'com.android.support:cardview-v7:4595f1c4a28cfa083b6c0920ad4d49e1c2ca4b8302a955e548f68eb63b74931b',
+			'com.jpardogo.materialtabstrip:library:24d19232b319f8c73e25793432357919a7ed972186f57a3b2c9093ea74ad8311',
+			'com.github.bumptech.glide:glide:76ef123957b5fbaebb05fcbe6606dd58c3bc3fcdadb257f99811d0ac9ea9b88b',
+			'uk.co.samuelwall:material-tap-target-prompt:f67e1caead12a914525b32cbf6da52a96b93ff89573f93cb41102ef3130fb64a',
 	]
 }
 
@@ -78,19 +82,14 @@ android {
 	defaultConfig {
 		minSdkVersion 14
 		targetSdkVersion 22
-		versionCode 1611
-		versionName "0.16.11"
-		applicationId "org.briarproject.briar.beta"
-		resValue "string", "app_package", "org.briarproject.briar.beta"
-		resValue "string", "app_name", "Briar Beta"
+		versionCode 14
+		versionName "0.14"
+		resValue "string", "app_package", "org.briarproject.briar"
 		buildConfigField "String", "GitHash", "\"${getGitHash()}\""
 	}
 
 	buildTypes {
 		debug {
-			applicationIdSuffix ".debug"
-			resValue "string", "app_package", "org.briarproject.briar.beta.debug"
-			resValue "string", "app_name", "Briar Debug"
 			shrinkResources false
 			minifyEnabled true
 			proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
@@ -107,13 +106,8 @@ android {
 		targetCompatibility JavaVersion.VERSION_1_7
 	}
 
-	aaptOptions {
-		cruncherEnabled = false
-	}
-
 	lintOptions {
 		warning 'MissingTranslation'
 		warning 'ImpliedQuantity'
-		warning 'ExtraTranslation'
 	}
 }

briar-android/src/main/AndroidManifest.xml

@@ -15,9 +15,11 @@
 	<uses-permission android:name="android.permission.READ_LOGS"/>
 	<uses-permission android:name="android.permission.VIBRATE" />
 	<uses-permission android:name="android.permission.WAKE_LOCK" />
+	<!-- Since API 23, this is needed to add contacts via Bluetooth -->
+	<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
 
 	<application
-		android:name="org.briarproject.briar.android.BriarApplicationImpl"
+		android:name=".android.BriarApplicationImpl"
 		android:allowBackup="false"
 		android:icon="@mipmap/ic_launcher_round"
 		android:label="@string/app_name"
@@ -25,20 +27,15 @@
 		android:theme="@style/BriarTheme">
 
 		<service
-			android:name="org.briarproject.briar.android.BriarService"
+			android:name=".android.BriarService"
 			android:exported="false">
 			<intent-filter>
 				<action android:name="org.briarproject.briar.android.BriarService"/>
 			</intent-filter>
 		</service>
 
-		<service
-			android:name="org.briarproject.briar.android.NotificationCleanupService"
-			android:exported="false">
-		</service>
-
 		<activity
-			android:name="org.briarproject.briar.android.reporting.DevReportActivity"
+			android:name=".android.reporting.DevReportActivity"
 			android:excludeFromRecents="true"
 			android:exported="false"
 			android:finishOnTaskLaunch="true"
@@ -50,24 +47,24 @@
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.splash.ExpiredActivity"
+			android:name=".android.splash.ExpiredActivity"
 			android:label="@string/app_name">
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.login.PasswordActivity"
+			android:name=".android.login.PasswordActivity"
 			android:label="@string/app_name"
 			android:windowSoftInputMode="stateVisible">
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.login.SetupActivity"
+			android:name=".android.login.SetupActivity"
 			android:label="@string/setup_title"
 			android:windowSoftInputMode="adjustResize">
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.splash.SplashScreenActivity"
+			android:name=".android.splash.SplashScreenActivity"
 			android:theme="@style/BriarTheme.NoActionBar"
 			android:label="@string/app_name">
 			<intent-filter>
@@ -77,258 +74,268 @@
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+			android:name=".android.navdrawer.NavDrawerActivity"
 			android:theme="@style/BriarTheme.NoActionBar"
 		    android:launchMode="singleTop">
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.contact.ConversationActivity"
+			android:name=".android.contact.ConversationActivity"
 			android:label="@string/app_name"
 			android:theme="@style/BriarTheme.NoActionBar"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
 			android:windowSoftInputMode="stateHidden|adjustResize">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+				android:value=".android.navdrawer.NavDrawerActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.privategroup.creation.CreateGroupActivity"
+			android:name=".android.privategroup.creation.CreateGroupActivity"
 			android:label="@string/groups_create_group_title"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
 			android:windowSoftInputMode="adjustResize">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+				android:value=".android.navdrawer.NavDrawerActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.privategroup.conversation.GroupActivity"
+			android:name=".android.privategroup.conversation.GroupActivity"
 			android:label="@string/app_name"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
 			android:theme="@style/BriarTheme.NoActionBar"
 			android:windowSoftInputMode="adjustResize|stateHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+				android:value=".android.navdrawer.NavDrawerActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.privategroup.invitation.GroupInvitationActivity"
+			android:name=".android.privategroup.invitation.GroupInvitationActivity"
 			android:label="@string/groups_invitations_title"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity">
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"/>
+				android:value=".android.navdrawer.NavDrawerActivity"/>
 		</activity>
 
 			<activity
-			android:name="org.briarproject.briar.android.privategroup.memberlist.GroupMemberListActivity"
+			android:name=".android.privategroup.memberlist.GroupMemberListActivity"
 			android:label="@string/groups_member_list"
-			android:parentActivityName="org.briarproject.briar.android.privategroup.conversation.GroupActivity"
+			android:parentActivityName=".android.privategroup.conversation.GroupActivity"
 			android:windowSoftInputMode="adjustResize|stateHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.privategroup.conversation.GroupActivity"
+				android:value=".android.privategroup.conversation.GroupActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.privategroup.reveal.RevealContactsActivity"
+			android:name=".android.privategroup.reveal.RevealContactsActivity"
 			android:label="@string/groups_reveal_contacts"
-			android:parentActivityName="org.briarproject.briar.android.privategroup.conversation.GroupActivity"
+			android:parentActivityName=".android.privategroup.conversation.GroupActivity"
 			android:windowSoftInputMode="adjustResize|stateAlwaysHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.privategroup.conversation.GroupActivity"
+				android:value=".android.privategroup.conversation.GroupActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.privategroup.creation.GroupInviteActivity"
+			android:name=".android.privategroup.creation.GroupInviteActivity"
 			android:label="@string/groups_invite_members"
-			android:parentActivityName="org.briarproject.briar.android.privategroup.conversation.GroupActivity"
+			android:parentActivityName=".android.privategroup.conversation.GroupActivity"
 			android:windowSoftInputMode="adjustResize|stateHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.privategroup.conversation.GroupActivity"/>
+				android:value=".android.privategroup.conversation.GroupActivity"/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.sharing.ForumInvitationActivity"
+			android:name=".android.sharing.ForumInvitationActivity"
 			android:label="@string/forum_invitations_title"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity">
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+				android:value=".android.navdrawer.NavDrawerActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.sharing.BlogInvitationActivity"
+			android:name=".android.sharing.BlogInvitationActivity"
 			android:label="@string/blogs_sharing_invitations_title"
-			android:parentActivityName="org.briarproject.briar.android.contact.ConversationActivity">
+			android:parentActivityName=".android.contact.ConversationActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.contact.ConversationActivity"
+				android:value=".android.contact.ConversationActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.forum.CreateForumActivity"
+			android:name=".android.forum.CreateForumActivity"
 			android:label="@string/create_forum_title"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
-			android:windowSoftInputMode="adjustResize">
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
+			android:windowSoftInputMode="stateVisible">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+				android:value=".android.navdrawer.NavDrawerActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.forum.ForumActivity"
+			android:name=".android.forum.ForumActivity"
 			android:label="@string/app_name"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
 			android:theme="@style/BriarTheme.NoActionBar"
 			android:windowSoftInputMode="adjustResize|stateHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+				android:value=".android.navdrawer.NavDrawerActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.sharing.ShareForumActivity"
+			android:name=".android.sharing.ShareForumActivity"
 			android:label="@string/activity_share_toolbar_header"
-			android:parentActivityName="org.briarproject.briar.android.forum.ForumActivity"
+			android:parentActivityName=".android.forum.ForumActivity"
 			android:windowSoftInputMode="adjustResize|stateHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.forum.ForumActivity"
+				android:value=".android.forum.ForumActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.sharing.ShareBlogActivity"
+			android:name=".android.sharing.ShareBlogActivity"
 			android:label="@string/activity_share_toolbar_header"
-			android:parentActivityName="org.briarproject.briar.android.blog.BlogActivity"
+			android:parentActivityName=".android.blog.BlogActivity"
 			android:windowSoftInputMode="adjustResize|stateHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.blog.BlogActivity"
+				android:value=".android.blog.BlogActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.sharing.ForumSharingStatusActivity"
+			android:name=".android.sharing.ForumSharingStatusActivity"
 			android:label="@string/sharing_status"
-			android:parentActivityName="org.briarproject.briar.android.forum.ForumActivity">
+			android:parentActivityName=".android.forum.ForumActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.forum.ForumActivity"
+				android:value=".android.forum.ForumActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.sharing.BlogSharingStatusActivity"
+			android:name=".android.sharing.BlogSharingStatusActivity"
 			android:label="@string/sharing_status"
-			android:parentActivityName="org.briarproject.briar.android.blog.BlogActivity">
+			android:parentActivityName=".android.blog.BlogActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.blog.BlogActivity"
+				android:value=".android.blog.BlogActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.blog.BlogActivity"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+			android:name=".android.blog.BlogActivity"
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
 			android:theme="@style/BriarTheme.NoActionBar">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"/>
+				android:value=".android.navdrawer.NavDrawerActivity"/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.blog.WriteBlogPostActivity"
+			android:name=".android.blog.WriteBlogPostActivity"
 			android:label="@string/blogs_write_blog_post"
-			android:parentActivityName="org.briarproject.briar.android.blog.BlogActivity"
+			android:parentActivityName=".android.blog.BlogActivity"
 			android:windowSoftInputMode="stateVisible|adjustResize">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.blog.BlogActivity"
+				android:value=".android.blog.BlogActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.blog.ReblogActivity"
+			android:name=".android.blog.ReblogActivity"
 			android:label="@string/blogs_reblog_button"
-			android:parentActivityName="org.briarproject.briar.android.blog.BlogActivity"
+			android:parentActivityName=".android.blog.BlogActivity"
 			android:windowSoftInputMode="stateHidden">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.blog.BlogActivity"
+				android:value=".android.blog.BlogActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.blog.RssFeedImportActivity"
+			android:name=".android.blog.RssFeedImportActivity"
 			android:label="@string/blogs_rss_feeds_import"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
 			android:windowSoftInputMode="stateVisible|adjustResize">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+				android:value=".android.navdrawer.NavDrawerActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.blog.RssFeedManageActivity"
+			android:name=".android.blog.RssFeedManageActivity"
 			android:label="@string/blogs_rss_feeds_manage"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity">
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+				android:value=".android.navdrawer.NavDrawerActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.keyagreement.KeyAgreementActivity"
+			android:name=".android.invitation.AddContactActivity"
+			android:label="@string/add_contact_title"
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value=".android.navdrawer.NavDrawerActivity"
+				/>
+		</activity>
+
+		<activity
+			android:name=".android.keyagreement.KeyAgreementActivity"
 			android:label="@string/add_contact_title"
 			android:theme="@style/BriarTheme.NoActionBar"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity">
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"/>
+				android:value=".android.navdrawer.NavDrawerActivity"/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.introduction.IntroductionActivity"
+			android:name=".android.introduction.IntroductionActivity"
 			android:label="@string/introduction_activity_title"
-			android:parentActivityName="org.briarproject.briar.android.contact.ConversationActivity"
+			android:parentActivityName=".android.contact.ConversationActivity"
 			android:windowSoftInputMode="stateHidden|adjustResize">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.contact.ConversationActivity"
+				android:value=".android.contact.ConversationActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.StartupFailureActivity"
+			android:name=".android.StartupFailureActivity"
 			android:label="@string/startup_failed_activity_title">
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.settings.SettingsActivity"
+			android:name=".android.settings.SettingsActivity"
 			android:label="@string/settings_button"
-			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
 			android:permission="android.permission.READ_NETWORK_USAGE_HISTORY">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
+				android:value=".android.navdrawer.NavDrawerActivity"
 				/>
 			<intent-filter>
 				<action android:name="android.intent.action.MANAGE_NETWORK_USAGE"/>
@@ -337,27 +344,27 @@
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.login.ChangePasswordActivity"
+			android:name=".android.login.ChangePasswordActivity"
 			android:label="@string/change_password"
-			android:parentActivityName="org.briarproject.briar.android.settings.SettingsActivity">
+			android:parentActivityName=".android.settings.SettingsActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.settings.SettingsActivity"
+				android:value=".android.settings.SettingsActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.panic.PanicPreferencesActivity"
+			android:name=".android.panic.PanicPreferencesActivity"
 			android:label="@string/panic_setting"
-			android:parentActivityName="org.briarproject.briar.android.settings.SettingsActivity">
+			android:parentActivityName=".android.settings.SettingsActivity">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
-				android:value="org.briarproject.briar.android.settings.SettingsActivity"
+				android:value=".android.settings.SettingsActivity"
 				/>
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.panic.PanicResponderActivity"
+			android:name=".android.panic.PanicResponderActivity"
 			android:noHistory="true"
 			android:theme="@android:style/Theme.NoDisplay">
 			<!-- this can never have launchMode singleTask or singleInstance! -->
@@ -368,7 +375,7 @@
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.panic.ExitActivity"
+			android:name=".android.panic.ExitActivity"
 			android:theme="@android:style/Theme.NoDisplay">
 		</activity>
 

briar-android/src/main/java/org/briarproject/briar/android/AndroidComponent.java

@@ -12,6 +12,7 @@ import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.invitation.InvitationTaskFactory;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementTaskFactory;
 import org.briarproject.bramble.api.keyagreement.PayloadEncoder;
 import org.briarproject.bramble.api.keyagreement.PayloadParser;
@@ -26,6 +27,7 @@ import org.briarproject.briar.BriarCoreEagerSingletons;
 import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.reporting.BriarReportSender;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
+import org.briarproject.briar.api.android.ReferenceManager;
 import org.briarproject.briar.api.android.ScreenFilterMonitor;
 import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogPostFactory;
@@ -43,7 +45,6 @@ import org.briarproject.briar.api.privategroup.PrivateGroupFactory;
 import org.briarproject.briar.api.privategroup.PrivateGroupManager;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationFactory;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager;
-import org.briarproject.briar.api.test.TestDataCreator;
 import org.thoughtcrime.securesms.components.emoji.EmojiProvider;
 import org.thoughtcrime.securesms.components.emoji.RecentEmojiPageModel;
 
@@ -73,6 +74,8 @@ public interface AndroidComponent
 
 	DatabaseConfig databaseConfig();
 
+	ReferenceManager referenceMangager();
+
 	@DatabaseExecutor
 	Executor databaseExecutor();
 
@@ -86,6 +89,8 @@ public interface AndroidComponent
 
 	EventBus eventBus();
 
+	InvitationTaskFactory invitationTaskFactory();
+
 	AndroidNotificationManager androidNotificationManager();
 
 	ScreenFilterMonitor screenFilterMonitor();
@@ -138,8 +143,6 @@ public interface AndroidComponent
 
 	Clock clock();
 
-	TestDataCreator testDataCreator();
-
 	@IoExecutor
 	Executor ioExecutor();
 
@@ -151,8 +154,6 @@ public interface AndroidComponent
 
 	void inject(RecentEmojiPageModel recentEmojiPageModel);
 
-	void inject(NotificationCleanupService notificationCleanupService);
-
 	// Eager singleton load
 	void inject(AppModule.EagerSingletons init);
 }

briar-android/src/main/java/org/briarproject/briar/android/AndroidNotificationManagerImpl.java

@@ -2,12 +2,14 @@ package org.briarproject.briar.android;
 
 import android.app.Application;
 import android.app.NotificationManager;
-import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
+import android.os.Build;
 import android.support.annotation.UiThread;
+import android.support.v4.app.NotificationCompat;
 import android.support.v4.app.TaskStackBuilder;
+import android.support.v4.content.ContextCompat;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
@@ -23,14 +25,12 @@ import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.system.AndroidExecutor;
-import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.contact.ConversationActivity;
 import org.briarproject.briar.android.forum.ForumActivity;
 import org.briarproject.briar.android.navdrawer.NavDrawerActivity;
 import org.briarproject.briar.android.privategroup.conversation.GroupActivity;
-import org.briarproject.briar.android.util.BriarNotificationBuilder;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.blog.event.BlogPostAddedEvent;
 import org.briarproject.briar.api.forum.event.ForumPostReceivedEvent;
@@ -48,7 +48,6 @@ import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
 import java.util.concurrent.Future;
-import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
@@ -62,6 +61,7 @@ import static android.content.Context.NOTIFICATION_SERVICE;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.support.v4.app.NotificationCompat.CATEGORY_MESSAGE;
 import static android.support.v4.app.NotificationCompat.CATEGORY_SOCIAL;
+import static android.support.v4.app.NotificationCompat.VISIBILITY_SECRET;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.contact.ConversationActivity.CONTACT_ID;
@@ -84,7 +84,15 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	private static final int BLOG_POST_NOTIFICATION_ID = 6;
 	private static final int INTRODUCTION_SUCCESS_NOTIFICATION_ID = 7;
 
-	private static final long SOUND_DELAY = TimeUnit.SECONDS.toMillis(2);
+	// Content URIs to differentiate between pending intents
+	private static final String CONTACT_URI =
+			"content://org.briarproject.briar/contact";
+	private static final String GROUP_URI =
+			"content://org.briarproject.briar/group";
+	private static final String FORUM_URI =
+			"content://org.briarproject.briar/forum";
+	private static final String BLOG_URI =
+			"content://org.briarproject.briar/blog";
 
 	private static final Logger LOG =
 			Logger.getLogger(AndroidNotificationManagerImpl.class.getName());
@@ -93,7 +101,6 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	private final SettingsManager settingsManager;
 	private final AndroidExecutor androidExecutor;
 	private final Context appContext;
-	private final Clock clock;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	// The following must only be accessed on the main UI thread
@@ -109,18 +116,16 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	private boolean blockContacts = false, blockGroups = false;
 	private boolean blockForums = false, blockBlogs = false;
 	private boolean blockIntroductions = false;
-	private long lastSound = 0;
 
 	private volatile Settings settings = new Settings();
 
 	@Inject
 	AndroidNotificationManagerImpl(@DatabaseExecutor Executor dbExecutor,
 			SettingsManager settingsManager, AndroidExecutor androidExecutor,
-			Application app, Clock clock) {
+			Application app) {
 		this.dbExecutor = dbExecutor;
 		this.settingsManager = settingsManager;
 		this.androidExecutor = androidExecutor;
-		this.clock = clock;
 		appContext = app.getApplicationContext();
 	}
 
@@ -259,7 +264,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				if (count == null) contactCounts.put(c, 1);
 				else contactCounts.put(c, count + 1);
 				contactTotal++;
-				updateContactNotification(true);
+				updateContactNotification();
 			}
 		});
 	}
@@ -272,30 +277,32 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				Integer count = contactCounts.remove(c);
 				if (count == null) return; // Already cleared
 				contactTotal -= count;
-				updateContactNotification(false);
+				updateContactNotification();
 			}
 		});
 	}
 
 	@UiThread
-	private void updateContactNotification(boolean mayAlertAgain) {
+	private void updateContactNotification() {
 		if (contactTotal == 0) {
 			clearContactNotification();
 		} else if (settings.getBoolean(PREF_NOTIFY_PRIVATE, true)) {
-			BriarNotificationBuilder b =
-					new BriarNotificationBuilder(appContext);
+			NotificationCompat.Builder b =
+					new NotificationCompat.Builder(appContext);
 			b.setSmallIcon(R.drawable.notification_private_message);
-			b.setColorRes(R.color.briar_primary);
+			b.setColor(ContextCompat.getColor(appContext,
+					R.color.briar_primary));
 			b.setContentTitle(appContext.getText(R.string.app_name));
 			b.setContentText(appContext.getResources().getQuantityString(
 					R.plurals.private_message_notification_text, contactTotal,
 					contactTotal));
-			b.setNumber(contactTotal);
-			boolean showOnLockScreen =
-					settings.getBoolean(PREF_NOTIFY_LOCK_SCREEN, false);
-			b.setLockscreenVisibility(CATEGORY_MESSAGE, showOnLockScreen);
-			if (mayAlertAgain) setAlertProperties(b);
-			setDeleteIntent(b, CONTACT_URI);
+			boolean sound = settings.getBoolean(PREF_NOTIFY_SOUND, true);
+			String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
+			if (sound && !StringUtils.isNullOrEmpty(ringtoneUri))
+				b.setSound(Uri.parse(ringtoneUri));
+			b.setDefaults(getDefaults());
+			b.setOnlyAlertOnce(true);
+			b.setAutoCancel(true);
 			if (contactCounts.size() == 1) {
 				// Touching the notification shows the relevant conversation
 				Intent i = new Intent(appContext, ConversationActivity.class);
@@ -318,25 +325,16 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				t.addNextIntent(i);
 				b.setContentIntent(t.getPendingIntent(nextRequestId++, 0));
 			}
+			if (Build.VERSION.SDK_INT >= 21) {
+				b.setCategory(CATEGORY_MESSAGE);
+				b.setVisibility(VISIBILITY_SECRET);
+			}
 			Object o = appContext.getSystemService(NOTIFICATION_SERVICE);
 			NotificationManager nm = (NotificationManager) o;
 			nm.notify(PRIVATE_MESSAGE_NOTIFICATION_ID, b.build());
 		}
 	}
 
-	@UiThread
-	private void setAlertProperties(BriarNotificationBuilder b) {
-		long currentTime = clock.currentTimeMillis();
-		if (currentTime - lastSound > SOUND_DELAY) {
-			boolean sound = settings.getBoolean(PREF_NOTIFY_SOUND, true);
-			String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
-			if (sound && !StringUtils.isNullOrEmpty(ringtoneUri))
-				b.setSound(Uri.parse(ringtoneUri));
-			b.setDefaults(getDefaults());
-			lastSound = currentTime;
-		}
-	}
-
 	@UiThread
 	private int getDefaults() {
 		int defaults = DEFAULT_LIGHTS;
@@ -349,19 +347,13 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		return defaults;
 	}
 
-	private void setDeleteIntent(BriarNotificationBuilder b, String uri) {
-		Intent i = new Intent(appContext, NotificationCleanupService.class);
-		i.setData(Uri.parse(uri));
-		b.setDeleteIntent(PendingIntent.getService(appContext, nextRequestId++,
-				i, 0));
-	}
-
 	@Override
 	public void clearAllContactNotifications() {
 		androidExecutor.runOnUiThread(new Runnable() {
 			@Override
 			public void run() {
 				clearContactNotification();
+				clearIntroductionSuccessNotification();
 			}
 		});
 	}
@@ -377,7 +369,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				if (count == null) groupCounts.put(g, 1);
 				else groupCounts.put(g, count + 1);
 				groupTotal++;
-				updateGroupMessageNotification(true);
+				updateGroupMessageNotification();
 			}
 		});
 	}
@@ -390,30 +382,31 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				Integer count = groupCounts.remove(g);
 				if (count == null) return; // Already cleared
 				groupTotal -= count;
-				updateGroupMessageNotification(false);
+				updateGroupMessageNotification();
 			}
 		});
 	}
 
 	@UiThread
-	private void updateGroupMessageNotification(boolean mayAlertAgain) {
+	private void updateGroupMessageNotification() {
 		if (groupTotal == 0) {
 			clearGroupMessageNotification();
 		} else if (settings.getBoolean(PREF_NOTIFY_GROUP, true)) {
-			BriarNotificationBuilder b =
-					new BriarNotificationBuilder(appContext);
+			NotificationCompat.Builder b =
+					new NotificationCompat.Builder(appContext);
 			b.setSmallIcon(R.drawable.notification_private_group);
-			b.setColorRes(R.color.briar_primary);
+			b.setColor(ContextCompat.getColor(appContext,
+					R.color.briar_primary));
 			b.setContentTitle(appContext.getText(R.string.app_name));
 			b.setContentText(appContext.getResources().getQuantityString(
 					R.plurals.group_message_notification_text, groupTotal,
 					groupTotal));
-			b.setNumber(groupTotal);
-			boolean showOnLockScreen =
-					settings.getBoolean(PREF_NOTIFY_LOCK_SCREEN, false);
-			b.setLockscreenVisibility(CATEGORY_SOCIAL, showOnLockScreen);
-			if (mayAlertAgain) setAlertProperties(b);
-			setDeleteIntent(b, GROUP_URI);
+			String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
+			if (!StringUtils.isNullOrEmpty(ringtoneUri))
+				b.setSound(Uri.parse(ringtoneUri));
+			b.setDefaults(getDefaults());
+			b.setOnlyAlertOnce(true);
+			b.setAutoCancel(true);
 			if (groupCounts.size() == 1) {
 				// Touching the notification shows the relevant group
 				Intent i = new Intent(appContext, GroupActivity.class);
@@ -437,6 +430,10 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				t.addNextIntent(i);
 				b.setContentIntent(t.getPendingIntent(nextRequestId++, 0));
 			}
+			if (Build.VERSION.SDK_INT >= 21) {
+				b.setCategory(CATEGORY_SOCIAL);
+				b.setVisibility(VISIBILITY_SECRET);
+			}
 			Object o = appContext.getSystemService(NOTIFICATION_SERVICE);
 			NotificationManager nm = (NotificationManager) o;
 			nm.notify(GROUP_MESSAGE_NOTIFICATION_ID, b.build());
@@ -464,7 +461,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				if (count == null) forumCounts.put(g, 1);
 				else forumCounts.put(g, count + 1);
 				forumTotal++;
-				updateForumPostNotification(true);
+				updateForumPostNotification();
 			}
 		});
 	}
@@ -477,30 +474,31 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				Integer count = forumCounts.remove(g);
 				if (count == null) return; // Already cleared
 				forumTotal -= count;
-				updateForumPostNotification(false);
+				updateForumPostNotification();
 			}
 		});
 	}
 
 	@UiThread
-	private void updateForumPostNotification(boolean mayAlertAgain) {
+	private void updateForumPostNotification() {
 		if (forumTotal == 0) {
 			clearForumPostNotification();
 		} else if (settings.getBoolean(PREF_NOTIFY_FORUM, true)) {
-			BriarNotificationBuilder b =
-					new BriarNotificationBuilder(appContext);
+			NotificationCompat.Builder b =
+					new NotificationCompat.Builder(appContext);
 			b.setSmallIcon(R.drawable.notification_forum);
-			b.setColorRes(R.color.briar_primary);
+			b.setColor(ContextCompat.getColor(appContext,
+					R.color.briar_primary));
 			b.setContentTitle(appContext.getText(R.string.app_name));
 			b.setContentText(appContext.getResources().getQuantityString(
 					R.plurals.forum_post_notification_text, forumTotal,
 					forumTotal));
-			b.setNumber(forumTotal);
-			boolean showOnLockScreen =
-					settings.getBoolean(PREF_NOTIFY_LOCK_SCREEN, false);
-			b.setLockscreenVisibility(CATEGORY_SOCIAL, showOnLockScreen);
-			if (mayAlertAgain) setAlertProperties(b);
-			setDeleteIntent(b, FORUM_URI);
+			String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
+			if (!StringUtils.isNullOrEmpty(ringtoneUri))
+				b.setSound(Uri.parse(ringtoneUri));
+			b.setDefaults(getDefaults());
+			b.setOnlyAlertOnce(true);
+			b.setAutoCancel(true);
 			if (forumCounts.size() == 1) {
 				// Touching the notification shows the relevant forum
 				Intent i = new Intent(appContext, ForumActivity.class);
@@ -524,6 +522,10 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				t.addNextIntent(i);
 				b.setContentIntent(t.getPendingIntent(nextRequestId++, 0));
 			}
+			if (Build.VERSION.SDK_INT >= 21) {
+				b.setCategory(CATEGORY_SOCIAL);
+				b.setVisibility(VISIBILITY_SECRET);
+			}
 			Object o = appContext.getSystemService(NOTIFICATION_SERVICE);
 			NotificationManager nm = (NotificationManager) o;
 			nm.notify(FORUM_POST_NOTIFICATION_ID, b.build());
@@ -551,7 +553,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				if (count == null) blogCounts.put(g, 1);
 				else blogCounts.put(g, count + 1);
 				blogTotal++;
-				updateBlogPostNotification(true);
+				updateBlogPostNotification();
 			}
 		});
 	}
@@ -564,30 +566,31 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				Integer count = blogCounts.remove(g);
 				if (count == null) return; // Already cleared
 				blogTotal -= count;
-				updateBlogPostNotification(false);
+				updateBlogPostNotification();
 			}
 		});
 	}
 
 	@UiThread
-	private void updateBlogPostNotification(boolean mayAlertAgain) {
+	private void updateBlogPostNotification() {
 		if (blogTotal == 0) {
 			clearBlogPostNotification();
 		} else if (settings.getBoolean(PREF_NOTIFY_BLOG, true)) {
-			BriarNotificationBuilder b =
-					new BriarNotificationBuilder(appContext);
+			NotificationCompat.Builder b =
+					new NotificationCompat.Builder(appContext);
 			b.setSmallIcon(R.drawable.notification_blog);
-			b.setColorRes(R.color.briar_primary);
+			b.setColor(ContextCompat.getColor(appContext,
+					R.color.briar_primary));
 			b.setContentTitle(appContext.getText(R.string.app_name));
 			b.setContentText(appContext.getResources().getQuantityString(
 					R.plurals.blog_post_notification_text, blogTotal,
 					blogTotal));
-			b.setNumber(blogTotal);
-			boolean showOnLockScreen =
-					settings.getBoolean(PREF_NOTIFY_LOCK_SCREEN, false);
-			b.setLockscreenVisibility(CATEGORY_SOCIAL, showOnLockScreen);
-			if (mayAlertAgain) setAlertProperties(b);
-			setDeleteIntent(b, BLOG_URI);
+			String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
+			if (!StringUtils.isNullOrEmpty(ringtoneUri))
+				b.setSound(Uri.parse(ringtoneUri));
+			b.setDefaults(getDefaults());
+			b.setOnlyAlertOnce(true);
+			b.setAutoCancel(true);
 			// Touching the notification shows the combined blog feed
 			Intent i = new Intent(appContext, NavDrawerActivity.class);
 			i.putExtra(INTENT_BLOGS, true);
@@ -597,7 +600,10 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 			t.addParentStack(NavDrawerActivity.class);
 			t.addNextIntent(i);
 			b.setContentIntent(t.getPendingIntent(nextRequestId++, 0));
-
+			if (Build.VERSION.SDK_INT >= 21) {
+				b.setCategory(CATEGORY_SOCIAL);
+				b.setVisibility(VISIBILITY_SECRET);
+			}
 			Object o = appContext.getSystemService(NOTIFICATION_SERVICE);
 			NotificationManager nm = (NotificationManager) o;
 			nm.notify(BLOG_POST_NOTIFICATION_ID, b.build());
@@ -627,18 +633,20 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 
 	@UiThread
 	private void updateIntroductionNotification() {
-		BriarNotificationBuilder b = new BriarNotificationBuilder(appContext);
+		NotificationCompat.Builder b =
+				new NotificationCompat.Builder(appContext);
 		b.setSmallIcon(R.drawable.notification_introduction);
-		b.setColorRes(R.color.briar_primary);
+		b.setColor(ContextCompat.getColor(appContext, R.color.briar_primary));
 		b.setContentTitle(appContext.getText(R.string.app_name));
 		b.setContentText(appContext.getResources().getQuantityString(
 				R.plurals.introduction_notification_text, introductionTotal,
 				introductionTotal));
-		boolean showOnLockScreen =
-				settings.getBoolean(PREF_NOTIFY_LOCK_SCREEN, false);
-		b.setLockscreenVisibility(CATEGORY_MESSAGE, showOnLockScreen);
-		setAlertProperties(b);
-		setDeleteIntent(b, INTRODUCTION_URI);
+		String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
+		if (!StringUtils.isNullOrEmpty(ringtoneUri))
+			b.setSound(Uri.parse(ringtoneUri));
+		b.setDefaults(getDefaults());
+		b.setOnlyAlertOnce(true);
+		b.setAutoCancel(true);
 		// Touching the notification shows the contact list
 		Intent i = new Intent(appContext, NavDrawerActivity.class);
 		i.putExtra(INTENT_CONTACTS, true);
@@ -648,22 +656,15 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		t.addParentStack(NavDrawerActivity.class);
 		t.addNextIntent(i);
 		b.setContentIntent(t.getPendingIntent(nextRequestId++, 0));
-
+		if (Build.VERSION.SDK_INT >= 21) {
+			b.setCategory(CATEGORY_MESSAGE);
+			b.setVisibility(VISIBILITY_SECRET);
+		}
 		Object o = appContext.getSystemService(NOTIFICATION_SERVICE);
 		NotificationManager nm = (NotificationManager) o;
 		nm.notify(INTRODUCTION_SUCCESS_NOTIFICATION_ID, b.build());
 	}
 
-	@Override
-	public void clearAllIntroductionNotifications() {
-		androidExecutor.runOnUiThread(new Runnable() {
-			@Override
-			public void run() {
-				clearIntroductionSuccessNotification();
-			}
-		});
-	}
-
 	@Override
 	public void blockNotification(final GroupId g) {
 		androidExecutor.runOnUiThread(new Runnable() {
@@ -704,6 +705,68 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		});
 	}
 
+	@Override
+	public void blockAllContactNotifications() {
+		androidExecutor.runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				blockContacts = true;
+				blockIntroductions = true;
+			}
+		});
+	}
+
+	@Override
+	public void unblockAllContactNotifications() {
+		androidExecutor.runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				blockContacts = false;
+				blockIntroductions = false;
+			}
+		});
+	}
+
+	@Override
+	public void blockAllGroupMessageNotifications() {
+		androidExecutor.runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				blockGroups = true;
+			}
+		});
+	}
+
+	@Override
+	public void unblockAllGroupMessageNotifications() {
+		androidExecutor.runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				blockGroups = false;
+			}
+		});
+	}
+
+	@Override
+	public void blockAllForumPostNotifications() {
+		androidExecutor.runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				blockForums = true;
+			}
+		});
+	}
+
+	@Override
+	public void unblockAllForumPostNotifications() {
+		androidExecutor.runOnUiThread(new Runnable() {
+			@Override
+			public void run() {
+				blockForums = false;
+			}
+		});
+	}
+
 	@Override
 	public void blockAllBlogPostNotifications() {
 		androidExecutor.runOnUiThread(new Runnable() {
@@ -723,4 +786,5 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 			}
 		});
 	}
+
 }

briar-android/src/main/java/org/briarproject/briar/android/AppModule.java

@@ -38,6 +38,8 @@ public class AppModule {
 	static class EagerSingletons {
 		@Inject
 		AndroidNotificationManager androidNotificationManager;
+		@Inject
+		ScreenFilterMonitor screenFilterMonitor;
 	}
 
 	private final Application application;
@@ -169,8 +171,10 @@ public class AppModule {
 	}
 
 	@Provides
+	@Singleton
 	ScreenFilterMonitor provideScreenFilterMonitor(
-			ScreenFilterMonitorImpl screenFilterMonitor) {
-		return screenFilterMonitor;
+			LifecycleManager lifecycleManager, ScreenFilterMonitorImpl sfm) {
+		lifecycleManager.registerService(sfm);
+		return sfm;
 	}
 }

briar-android/src/main/java/org/briarproject/briar/android/BriarApplication.java

@@ -6,9 +6,5 @@ package org.briarproject.briar.android;
  */
 public interface BriarApplication {
 
-	// This build expires on 31 December 2017
-	long EXPIRY_DATE = 1514761200 * 1000L;
-
 	AndroidComponent getApplicationComponent();
-
 }

briar-android/src/main/java/org/briarproject/briar/android/BriarApplicationImpl.java

@@ -2,9 +2,6 @@ package org.briarproject.briar.android;
 
 import android.app.Application;
 import android.content.Context;
-import android.os.StrictMode;
-import android.os.StrictMode.ThreadPolicy;
-import android.os.StrictMode.VmPolicy;
 
 import org.acra.ACRA;
 import org.acra.ReportingInteractionMode;
@@ -36,8 +33,6 @@ import static org.acra.ReportField.REPORT_ID;
 import static org.acra.ReportField.STACK_TRACE;
 import static org.acra.ReportField.USER_APP_START_DATE;
 import static org.acra.ReportField.USER_CRASH_DATE;
-import static org.briarproject.briar.android.TestingConstants.DEFAULT_LOG_LEVEL;
-import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 
 @ReportsCrashes(
 		reportPrimerClass = BriarReportPrimer.class,
@@ -77,9 +72,6 @@ public class BriarApplicationImpl extends Application
 	@Override
 	public void onCreate() {
 		super.onCreate();
-
-		if (IS_DEBUG_BUILD) enableStrictMode();
-		Logger.getLogger("").setLevel(DEFAULT_LOG_LEVEL);
 		LOG.info("Created");
 
 		applicationComponent = DaggerAndroidComponent.builder()
@@ -93,17 +85,6 @@ public class BriarApplicationImpl extends Application
 		AndroidEagerSingletons.initEagerSingletons(applicationComponent);
 	}
 
-	private void enableStrictMode() {
-		ThreadPolicy.Builder threadPolicy = new ThreadPolicy.Builder();
-		threadPolicy.detectAll();
-		threadPolicy.penaltyLog();
-		StrictMode.setThreadPolicy(threadPolicy.build());
-		VmPolicy.Builder vmPolicy = new VmPolicy.Builder();
-		vmPolicy.detectAll();
-		vmPolicy.penaltyLog();
-		StrictMode.setVmPolicy(vmPolicy.build());
-	}
-
 	@Override
 	public AndroidComponent getApplicationComponent() {
 		return applicationComponent;

briar-android/src/main/java/org/briarproject/briar/android/NotificationCleanupService.java

@@ -1,53 +0,0 @@
-package org.briarproject.briar.android;
-
-import android.app.IntentService;
-import android.content.Intent;
-import android.support.annotation.Nullable;
-
-import org.briarproject.briar.api.android.AndroidNotificationManager;
-
-import javax.inject.Inject;
-
-import static org.briarproject.briar.api.android.AndroidNotificationManager.BLOG_URI;
-import static org.briarproject.briar.api.android.AndroidNotificationManager.CONTACT_URI;
-import static org.briarproject.briar.api.android.AndroidNotificationManager.FORUM_URI;
-import static org.briarproject.briar.api.android.AndroidNotificationManager.GROUP_URI;
-import static org.briarproject.briar.api.android.AndroidNotificationManager.INTRODUCTION_URI;
-
-public class NotificationCleanupService extends IntentService {
-
-	private static final String TAG =
-			NotificationCleanupService.class.getName();
-
-	@Inject
-	AndroidNotificationManager notificationManager;
-
-	public NotificationCleanupService() {
-		super(TAG);
-	}
-
-	@Override
-	public void onCreate() {
-		super.onCreate();
-		AndroidComponent applicationComponent =
-				((BriarApplication) getApplication()).getApplicationComponent();
-		applicationComponent.inject(this);
-	}
-
-	@Override
-	protected void onHandleIntent(@Nullable Intent i) {
-		if (i == null || i.getData() == null) return;
-		String uri = i.getData().toString();
-		if (uri.equals(CONTACT_URI)) {
-			notificationManager.clearAllContactNotifications();
-		} else if (uri.equals(GROUP_URI)) {
-			notificationManager.clearAllGroupMessageNotifications();
-		} else if (uri.equals(FORUM_URI)) {
-			notificationManager.clearAllForumPostNotifications();
-		} else if (uri.equals(BLOG_URI)) {
-			notificationManager.clearAllBlogPostNotifications();
-		} else if (uri.equals(INTRODUCTION_URI)) {
-			notificationManager.clearAllIntroductionNotifications();
-		}
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/ScreenFilterMonitorImpl.java

@@ -1,13 +1,23 @@
 package org.briarproject.briar.android;
 
 import android.app.Application;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.SharedPreferences;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.Signature;
 import android.support.annotation.UiThread;
+import android.support.v7.preference.PreferenceManager;
 
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.lifecycle.Service;
+import org.briarproject.bramble.api.lifecycle.ServiceException;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.api.android.ScreenFilterMonitor;
 
@@ -16,26 +26,38 @@ import java.io.InputStream;
 import java.security.cert.CertificateException;
 import java.security.cert.CertificateFactory;
 import java.security.cert.X509Certificate;
+import java.util.Collection;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 import java.util.TreeSet;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static android.Manifest.permission.SYSTEM_ALERT_WINDOW;
+import static android.content.Intent.ACTION_PACKAGE_ADDED;
+import static android.content.Intent.EXTRA_REPLACING;
 import static android.content.pm.ApplicationInfo.FLAG_SYSTEM;
 import static android.content.pm.ApplicationInfo.FLAG_UPDATED_SYSTEM_APP;
 import static android.content.pm.PackageManager.GET_PERMISSIONS;
 import static android.content.pm.PackageManager.GET_SIGNATURES;
 import static java.util.logging.Level.WARNING;
 
-@NotNullByDefault
-class ScreenFilterMonitorImpl implements ScreenFilterMonitor {
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class ScreenFilterMonitorImpl extends BroadcastReceiver
+		implements Service, ScreenFilterMonitor {
 
 	private static final Logger LOG =
 			Logger.getLogger(ScreenFilterMonitorImpl.class.getName());
+	private static final String PREF_SCREEN_FILTER_APPS =
+			"shownScreenFilterApps";
 
 	/*
  	 * Ignore Play Services if it uses this package name and public key - it's
@@ -56,17 +78,124 @@ class ScreenFilterMonitorImpl implements ScreenFilterMonitor {
 					"82BA35E003C1B4B10DD244A8EE24FFFD333872AB5221985EDAB0FC0D" +
 					"0B145B6AA192858E79020103";
 
+	private final Context appContext;
+	private final AndroidExecutor androidExecutor;
 	private final PackageManager pm;
+	private final SharedPreferences prefs;
+	private final AtomicBoolean used = new AtomicBoolean(false);
+
+	// The following must only be accessed on the UI thread
+	private final Set<String> apps = new HashSet<>();
+	private final Set<String> shownApps;
+	private boolean serviceStarted = false;
 
 	@Inject
-	ScreenFilterMonitorImpl(Application app) {
-		pm = app.getPackageManager();
+	ScreenFilterMonitorImpl(AndroidExecutor executor, Application app) {
+		this.androidExecutor = executor;
+		this.appContext = app;
+		pm = appContext.getPackageManager();
+		prefs = PreferenceManager.getDefaultSharedPreferences(appContext);
+		shownApps = getShownScreenFilterApps();
+	}
+
+	@Override
+	public void startService() throws ServiceException {
+		if (used.getAndSet(true)) throw new IllegalStateException();
+		Future<Void> f = androidExecutor.runOnUiThread(new Callable<Void>() {
+			@Override
+			public Void call() {
+				IntentFilter intentFilter = new IntentFilter();
+				intentFilter.addAction(ACTION_PACKAGE_ADDED);
+				intentFilter.addDataScheme("package");
+				appContext.registerReceiver(ScreenFilterMonitorImpl.this,
+						intentFilter);
+				apps.addAll(getInstalledScreenFilterApps());
+				serviceStarted = true;
+				return null;
+			}
+		});
+		try {
+			f.get();
+		} catch (InterruptedException | ExecutionException e) {
+			throw new ServiceException(e);
+		}
+	}
+
+	@Override
+	public void stopService() throws ServiceException {
+		Future<Void> f = androidExecutor.runOnUiThread(new Callable<Void>() {
+			@Override
+			public Void call() {
+				serviceStarted = false;
+				appContext.unregisterReceiver(ScreenFilterMonitorImpl.this);
+				return null;
+			}
+		});
+		try {
+			f.get();
+		} catch (InterruptedException | ExecutionException e) {
+			throw new ServiceException(e);
+		}
+	}
+
+	private Set<String> getShownScreenFilterApps() {
+		// Result must not be modified
+		Set<String> s = prefs.getStringSet(PREF_SCREEN_FILTER_APPS, null);
+		HashSet<String> result = new HashSet<>();
+		if (s != null) {
+			result.addAll(s);
+		}
+		return result;
+	}
+
+	@Override
+	public void onReceive(Context context, Intent intent) {
+		if (!intent.getBooleanExtra(EXTRA_REPLACING, false)) {
+			final String packageName =
+					intent.getData().getEncodedSchemeSpecificPart();
+			androidExecutor.runOnUiThread(new Runnable() {
+				@Override
+				public void run() {
+					String pkg = isOverlayApp(packageName);
+					if (pkg == null) {
+						return;
+					}
+					apps.add(pkg);
+				}
+			});
+		}
 	}
 
 	@Override
 	@UiThread
 	public Set<String> getApps() {
-		Set<String> screenFilterApps = new TreeSet<>();
+		if (!serviceStarted) {
+			apps.addAll(getInstalledScreenFilterApps());
+		}
+		TreeSet<String> buf = new TreeSet<>();
+		if (apps.isEmpty()) {
+			return buf;
+		}
+		buf.addAll(apps);
+		buf.removeAll(shownApps);
+		return buf;
+	}
+
+	@Override
+	@UiThread
+	public void storeAppsAsShown(Collection<String> s, boolean persistent) {
+		HashSet<String> buf = new HashSet<>(s);
+		shownApps.addAll(buf);
+		if (persistent && !s.isEmpty()) {
+			buf.addAll(getShownScreenFilterApps());
+			prefs.edit()
+					.putStringSet(PREF_SCREEN_FILTER_APPS, buf)
+					.apply();
+		}
+	}
+
+	private Set<String> getInstalledScreenFilterApps() {
+		HashSet<String> screenFilterApps = new HashSet<>();
 		List<PackageInfo> packageInfos =
 				pm.getInstalledPackages(GET_PERMISSIONS);
 		for (PackageInfo packageInfo : packageInfos) {
@@ -80,6 +209,21 @@ class ScreenFilterMonitorImpl implements ScreenFilterMonitor {
 		return screenFilterApps;
 	}
 
+	// Checks if a package uses the SYSTEM_ALERT_WINDOW permission and if so
+	// returns the app name.
+	@Nullable
+	private String isOverlayApp(String pkg) {
+		try {
+			PackageInfo pkgInfo = pm.getPackageInfo(pkg, GET_PERMISSIONS);
+			if (isOverlayApp(pkgInfo)) {
+				return pkgToString(pkgInfo);
+			}
+		} catch (NameNotFoundException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		}
+		return null;
+	}
+
 	// Fetches the application name for a given package.
 	@Nullable
 	private String pkgToString(PackageInfo pkgInfo) {

briar-android/src/main/java/org/briarproject/briar/android/TestingConstants.java

@@ -10,21 +10,13 @@ import static java.util.logging.Level.OFF;
 public interface TestingConstants {
 
 	/**
-	 * Whether this is a debug build.
-	 */
-	boolean IS_DEBUG_BUILD = BuildConfig.DEBUG;
-
-	/**
-	 * Whether this is a beta build. This should be set to false for final
+	 * Whether this is an alpha or beta build. This should be set to false for
 	 * release builds.
 	 */
-	boolean IS_BETA_BUILD = true;
+	boolean TESTING = BuildConfig.DEBUG;
 
-	/**
-	 * Default log level. Disable logging for final release builds.
-	 */
-	@SuppressWarnings("ConstantConditions")
-	Level DEFAULT_LOG_LEVEL = IS_DEBUG_BUILD || IS_BETA_BUILD ? INFO : OFF;
+	/** Default log level. */
+	Level DEFAULT_LOG_LEVEL = TESTING ? INFO : OFF;
 
 	/**
 	 * Whether to prevent screenshots from being taken. Setting this to true
@@ -32,5 +24,5 @@ public interface TestingConstants {
 	 * Unfortunately this also prevents the user from taking screenshots
 	 * intentionally.
 	 */
-	boolean PREVENT_SCREENSHOTS = !IS_DEBUG_BUILD;
+	boolean PREVENT_SCREENSHOTS = !TESTING;
 }

briar-android/src/main/java/org/briarproject/briar/android/activity/ActivityComponent.java

@@ -24,6 +24,7 @@ import org.briarproject.briar.android.forum.ForumModule;
 import org.briarproject.briar.android.introduction.ContactChooserFragment;
 import org.briarproject.briar.android.introduction.IntroductionActivity;
 import org.briarproject.briar.android.introduction.IntroductionMessageFragment;
+import org.briarproject.briar.android.invitation.AddContactActivity;
 import org.briarproject.briar.android.keyagreement.IntroFragment;
 import org.briarproject.briar.android.keyagreement.KeyAgreementActivity;
 import org.briarproject.briar.android.keyagreement.ShowQrCodeFragment;
@@ -38,7 +39,7 @@ import org.briarproject.briar.android.privategroup.conversation.GroupConversatio
 import org.briarproject.briar.android.privategroup.creation.CreateGroupActivity;
 import org.briarproject.briar.android.privategroup.creation.CreateGroupFragment;
 import org.briarproject.briar.android.privategroup.creation.CreateGroupMessageFragment;
-import org.briarproject.briar.android.privategroup.creation.CreateGroupModule;
+import org.briarproject.briar.android.privategroup.creation.GroupCreateModule;
 import org.briarproject.briar.android.privategroup.creation.GroupInviteActivity;
 import org.briarproject.briar.android.privategroup.creation.GroupInviteFragment;
 import org.briarproject.briar.android.privategroup.invitation.GroupInvitationActivity;
@@ -51,7 +52,6 @@ import org.briarproject.briar.android.privategroup.reveal.GroupRevealModule;
 import org.briarproject.briar.android.privategroup.reveal.RevealContactsActivity;
 import org.briarproject.briar.android.privategroup.reveal.RevealContactsFragment;
 import org.briarproject.briar.android.settings.SettingsActivity;
-import org.briarproject.briar.android.settings.SettingsFragment;
 import org.briarproject.briar.android.sharing.BlogInvitationActivity;
 import org.briarproject.briar.android.sharing.BlogSharingStatusActivity;
 import org.briarproject.briar.android.sharing.ForumInvitationActivity;
@@ -71,7 +71,7 @@ import dagger.Component;
 @Component(
 		modules = {ActivityModule.class, ForumModule.class, SharingModule.class,
 				BlogModule.class, ContactModule.class, GroupListModule.class,
-				CreateGroupModule.class, GroupInvitationModule.class,
+				GroupCreateModule.class, GroupInvitationModule.class,
 				GroupConversationModule.class, GroupMemberModule.class,
 				GroupRevealModule.class},
 		dependencies = AndroidComponent.class)
@@ -91,6 +91,8 @@ public interface ActivityComponent {
 
 	void inject(PanicPreferencesActivity activity);
 
+	void inject(AddContactActivity activity);
+
 	void inject(KeyAgreementActivity activity);
 
 	void inject(ConversationActivity activity);
@@ -180,6 +182,4 @@ public interface ActivityComponent {
 
 	void inject(IntroductionMessageFragment fragment);
 
-	void inject(SettingsFragment fragment);
-
 }

briar-android/src/main/java/org/briarproject/briar/android/activity/BaseActivity.java

@@ -2,13 +2,9 @@ package org.briarproject.briar.android.activity;
 
 import android.os.Bundle;
 import android.os.IBinder;
-import android.support.annotation.LayoutRes;
 import android.support.annotation.UiThread;
 import android.support.v7.app.AppCompatActivity;
-import android.support.v7.widget.Toolbar;
 import android.view.View;
-import android.view.ViewGroup;
-import android.view.ViewGroup.LayoutParams;
 import android.view.inputmethod.InputMethodManager;
 
 import org.briarproject.bramble.api.db.DbException;
@@ -17,9 +13,7 @@ import org.briarproject.briar.android.BriarApplication;
 import org.briarproject.briar.android.DestroyableContext;
 import org.briarproject.briar.android.controller.ActivityLifecycleController;
 import org.briarproject.briar.android.forum.ForumModule;
-import org.briarproject.briar.android.fragment.ScreenFilterDialogFragment;
-import org.briarproject.briar.android.widget.TapSafeFrameLayout;
-import org.briarproject.briar.android.widget.TapSafeFrameLayout.OnTapFilteredListener;
+import org.briarproject.briar.android.fragment.SFDialogFragment;
 import org.briarproject.briar.api.android.ScreenFilterMonitor;
 
 import java.util.ArrayList;
@@ -29,23 +23,21 @@ import java.util.Set;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import static android.view.ViewGroup.LayoutParams.MATCH_PARENT;
 import static android.view.WindowManager.LayoutParams.FLAG_SECURE;
 import static android.view.inputmethod.InputMethodManager.SHOW_IMPLICIT;
 import static org.briarproject.briar.android.TestingConstants.PREVENT_SCREENSHOTS;
 
 public abstract class BaseActivity extends AppCompatActivity
-		implements DestroyableContext, OnTapFilteredListener {
-
-	@Inject
-	protected ScreenFilterMonitor screenFilterMonitor;
-
+		implements DestroyableContext {
 	protected ActivityComponent activityComponent;
 
 	private final List<ActivityLifecycleController> lifecycleControllers =
 			new ArrayList<>();
 	private boolean destroyed = false;
-	private ScreenFilterDialogFragment dialogFrag;
+
+	@Inject
+	protected ScreenFilterMonitor screenFilterMonitor;
+	private SFDialogFragment dialogFrag;
 
 	public abstract void injectActivity(ActivityComponent component);
 
@@ -73,6 +65,7 @@ public abstract class BaseActivity extends AppCompatActivity
 		for (ActivityLifecycleController alc : lifecycleControllers) {
 			alc.onActivityCreate(this);
 		}
+
 	}
 
 	public ActivityComponent getActivityComponent() {
@@ -104,6 +97,12 @@ public abstract class BaseActivity extends AppCompatActivity
 		}
 	}
 
+	@Override
+	protected void onPostResume() {
+		super.onPostResume();
+		showNewScreenFilterWarning();
+	}
+
 	@Override
 	protected void onPause() {
 		super.onPause();
@@ -113,14 +112,18 @@ public abstract class BaseActivity extends AppCompatActivity
 		}
 	}
 
-	private void showScreenFilterWarning() {
-		if (dialogFrag != null && dialogFrag.isVisible()) return;
-		Set<String> apps = screenFilterMonitor.getApps();
-		if (apps.isEmpty()) return;
-		dialogFrag =
-				ScreenFilterDialogFragment.newInstance(new ArrayList<>(apps));
+	protected void showNewScreenFilterWarning() {
+		final Set<String> apps = screenFilterMonitor.getApps();
+		if (apps.isEmpty()) {
+			return;
+		}
+		dialogFrag = SFDialogFragment.newInstance(new ArrayList<>(apps));
 		dialogFrag.setCancelable(false);
-		dialogFrag.show(getSupportFragmentManager(), dialogFrag.getTag());
+		dialogFrag.show(getSupportFragmentManager(), "SFDialog");
+	}
+
+	public void rememberShownApps(ArrayList<String> s, boolean permanent) {
+		screenFilterMonitor.storeAppsAsShown(s, permanent);
 	}
 
 	@Override
@@ -158,70 +161,4 @@ public abstract class BaseActivity extends AppCompatActivity
 		supportFinishAfterTransition();
 	}
 
-	/*
-	 * Wraps the given view in a wrapper that notifies this activity when an
-	 * obscured touch has been filtered, and returns the wrapper.
-	 */
-	private View makeTapSafeWrapper(View v) {
-		TapSafeFrameLayout wrapper = new TapSafeFrameLayout(this);
-		wrapper.setLayoutParams(new LayoutParams(MATCH_PARENT, MATCH_PARENT));
-		wrapper.setOnTapFilteredListener(this);
-		wrapper.addView(v);
-		return wrapper;
-	}
-
-	/*
-	 * Finds the AppCompat toolbar, if any, and configures it to filter
-	 * obscured touches. If a custom toolbar is used, it will be part of the
-	 * content view and thus protected by the wrapper. But the default toolbar
-	 * is outside the wrapper.
-	 */
-	private void protectToolbar() {
-		View decorView = getWindow().getDecorView();
-		if (decorView instanceof ViewGroup) {
-			Toolbar toolbar = findToolbar((ViewGroup) decorView);
-			if (toolbar != null) toolbar.setFilterTouchesWhenObscured(true);
-		}
-	}
-
-	@Nullable
-	private Toolbar findToolbar(ViewGroup vg) {
-		for (int i = 0, len = vg.getChildCount(); i < len; i++) {
-			View child = vg.getChildAt(i);
-			if (child instanceof Toolbar) return (Toolbar) child;
-			if (child instanceof ViewGroup) {
-				Toolbar toolbar = findToolbar((ViewGroup) child);
-				if (toolbar != null) return toolbar;
-			}
-		}
-		return null;
-	}
-
-	@Override
-	public void setContentView(@LayoutRes int layoutRes) {
-		setContentView(getLayoutInflater().inflate(layoutRes, null));
-	}
-
-	@Override
-	public void setContentView(View v) {
-		super.setContentView(makeTapSafeWrapper(v));
-		protectToolbar();
-	}
-
-	@Override
-	public void setContentView(View v, LayoutParams layoutParams) {
-		super.setContentView(makeTapSafeWrapper(v), layoutParams);
-		protectToolbar();
-	}
-
-	@Override
-	public void addContentView(View v, LayoutParams layoutParams) {
-		super.addContentView(makeTapSafeWrapper(v), layoutParams);
-		protectToolbar();
-	}
-
-	@Override
-	public void onTapFiltered() {
-		showScreenFilterWarning();
-	}
 }