Use WhisperSystems Curve25519 library.

Note: Curve25519 is tested using standard ECDH and ECDHC over the Curve25519 curve.

.gitlab-ci.yml

@@ -6,9 +6,18 @@ cache:
     - .gradle/caches
 
 before_script:
+  - set -e
   - export GRADLE_USER_HOME=$PWD/.gradle
-#  - 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-${ANDROID_COMPILE_SDK}
+  # Accept the license for the Android build tools
+  - echo y | /opt/android-sdk/tools/bin/sdkmanager "build-tools;26.0.2"
+  # Download OpenJDK 6 so we can compile against its standard library
+  - JDK_FILE=openjdk-6-jre-headless_6b38-1.13.10-1~deb7u1_amd64.deb
+  - if [ ! -d openjdk ]
+  - then
+  - wget -q http://ftp.uk.debian.org/debian/pool/main/o/openjdk-6/$JDK_FILE
+  - dpkg-deb -x $JDK_FILE openjdk
+  - fi
+  - export JAVA_6_HOME=$PWD/openjdk/usr/lib/jvm/java-6-openjdk-amd64
 
 test:
   script:

bramble-android/build.gradle

@@ -6,99 +6,91 @@ apply plugin: 'witness'
 apply plugin: 'de.undercouch.download'
 
 android {
-	compileSdkVersion 23
-	buildToolsVersion "23.0.3"
+	compileSdkVersion 27
+	buildToolsVersion '26.0.2'
 
 	defaultConfig {
 		minSdkVersion 14
-		targetSdkVersion 22
-		versionCode 14
-		versionName "0.14"
+		targetSdkVersion 26
+		versionCode 1700
+		versionName "0.17.0"
 		consumerProguardFiles 'proguard-rules.txt'
 	}
 
 	compileOptions {
-		sourceCompatibility JavaVersion.VERSION_1_7
-		targetCompatibility JavaVersion.VERSION_1_7
+		sourceCompatibility JavaVersion.VERSION_1_8
+		targetCompatibility JavaVersion.VERSION_1_8
 	}
 }
 
 dependencies {
-	compile project(':bramble-core')
-	compile fileTree(dir: 'libs', include: '*.jar')
-	provided 'javax.annotation:jsr250-api:1.0'
+	implementation project(path: ':bramble-core', configuration: 'default')
+	implementation fileTree(dir: 'libs', include: '*.jar')
+
+	annotationProcessor 'com.google.dagger:dagger-compiler:2.0.2'
+
+	compileOnly 'javax.annotation:jsr250-api:1.0'
 }
 
-def torBinaryDir = 'src/main/res/raw'
-
-task downloadTorGeoIp(type: Download) {
-	src 'https://briarproject.org/build/geoip-2017-05-02.zip'
-	dest "$torBinaryDir/geoip.zip"
-	onlyIfNewer true
+dependencyVerification {
+	verify = [
+			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+			'com.google.dagger:dagger-compiler:2.0.2:dagger-compiler-2.0.2.jar:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
+			'com.google.dagger:dagger-producers:2.0-beta:dagger-producers-2.0-beta.jar:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
+			'com.google.dagger:dagger:2.0.2:dagger-2.0.2.jar:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
+			'com.google.guava:guava:18.0:guava-18.0.jar:d664fbfc03d2e5ce9cab2a44fb01f1d0bf9dfebeccc1a473b1f9ea31f79f6f99',
+			'com.h2database:h2:1.4.192:h2-1.4.192.jar:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
+			'com.madgag.spongycastle:core:1.58.0.0:core-1.58.0.0.jar:199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728',
+			'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
+			'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
+			'net.i2p.crypto:eddsa:0.2.0:eddsa-0.2.0.jar:a7cb1b85c16e2f0730b9204106929a1d9aaae1df728adc7041a8b8b605692140',
+			'org.bitlet:weupnp:0.1.4:weupnp-0.1.4.jar:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
+			'org.jacoco:org.jacoco.agent:0.7.4.201502262128:org.jacoco.agent-0.7.4.201502262128-runtime.jar:e357a0f1d573c2f702a273992b1b6cb661734f66311854efb3778a888515c5b5',
+			'org.jacoco:org.jacoco.agent:0.7.4.201502262128:org.jacoco.agent-0.7.4.201502262128.jar:47b4bec6df11a1118da3953da8b9fa1e7079d6fec857faa1a3cf912e53a6fd4e',
+			'org.jacoco:org.jacoco.ant:0.7.4.201502262128:org.jacoco.ant-0.7.4.201502262128.jar:013ce2a68ba57a3c59215ae0dec4df3498c078062a38c3b94c841fc14450f283',
+			'org.jacoco:org.jacoco.core:0.7.4.201502262128:org.jacoco.core-0.7.4.201502262128.jar:ec4c74554312fac5116350164786f91b35c9e082fa4ea598bfa42b5db05d7abb',
+			'org.jacoco:org.jacoco.report:0.7.4.201502262128:org.jacoco.report-0.7.4.201502262128.jar:7a3554c605e088e7e323b1084656243f0444fa353e2f2dee1f1a4204eb64ff09',
+			'org.ow2.asm:asm-debug-all:5.0.1:asm-debug-all-5.0.1.jar:4734de5b515a454b0096db6971fb068e5f70e6f10bbee2b3bd2fdfe5d978ed57',
+	]
 }
 
-task downloadTorBinaryArm(type: Download) {
-	src 'https://briarproject.org/build/tor-0.2.9.11-arm.zip'
-	dest "$torBinaryDir/tor_arm.zip"
-	onlyIfNewer true
+ext.torBinaryDir = 'src/main/res/raw'
+ext.torVersion = '0.2.9.12'
+ext.geoipVersion = '2017-09-06'
+ext.torDownloadUrl = 'https://briarproject.org/build/'
+
+def torBinaries = [
+		"tor_arm"    : '8ed0b347ffed1d6a4d2fd14495118eb92be83e9cc06e057e15220dc288b31688',
+		"tor_arm_pie": '64403262511c29f462ca5e7c7621bfc3c944898364d1d5ad35a016bb8a034283',
+		"tor_x86"    : '61e014607a2079bcf1646289c67bff6372b1aded6e1d8d83d7791efda9a4d5ab',
+		"tor_x86_pie": '18fbc98356697dd0895836ab46d5c9877d1c539193464f7db1e82a65adaaf288',
+		"geoip"      : 'fe49d3adb86d3c512373101422a017dbb86c85a570524663f09dd8ce143a24f3'
+]
+
+def downloadBinary(name) {
+	return tasks.create("downloadBinary${name}", Download) {
+		src "${torDownloadUrl}${name}.zip"
+				.replace('tor_', "tor-${torVersion}-")
+				.replace('geoip', "geoip-${geoipVersion}")
+				.replaceAll('_', '-')
+		dest "${torBinaryDir}/${name}.zip"
+		onlyIfNewer true
+	}
 }
 
-task downloadTorBinaryArmPie(type: Download) {
-	src 'https://briarproject.org/build/tor-0.2.9.11-arm-pie.zip'
-	dest "$torBinaryDir/tor_arm_pie.zip"
-	onlyIfNewer true
-}
-
-task downloadTorBinaryX86(type: Download) {
-	src 'https://briarproject.org/build/tor-0.2.9.11-x86.zip'
-	dest "$torBinaryDir/tor_x86.zip"
-	onlyIfNewer true
-}
-
-task downloadTorBinaryX86Pie(type: Download) {
-	src 'https://briarproject.org/build/tor-0.2.9.11-x86-pie.zip'
-	dest "$torBinaryDir/tor_x86_pie.zip"
-	onlyIfNewer true
-}
-
-task verifyTorGeoIp(type: Verify, dependsOn: 'downloadTorGeoIp') {
-	src "$torBinaryDir/geoip.zip"
-	algorithm 'SHA-256'
-	checksum '51f4d1272fb867e1f3b36b67a584e2a33c40b40f62305457d799fd399cd77c9b'
-}
-
-task verifyTorBinaryArm(type: Verify, dependsOn: 'downloadTorBinaryArm') {
-	src "$torBinaryDir/tor_arm.zip"
-	algorithm 'SHA-256'
-	checksum '1da6008663a8ad98b349e62acbbf42c379f65ec504fa467cb119c187cd5a4c6b'
-}
-
-task verifyTorBinaryArmPie(type: Verify, dependsOn: 'downloadTorBinaryArmPie') {
-	src "$torBinaryDir/tor_arm_pie.zip"
-	algorithm 'SHA-256'
-	checksum 'eb061f880829e05f104690ac744848133f2dacef04759d425a2cff0df32c271e'
-}
-
-task verifyTorBinaryX86(type: Verify, dependsOn: 'downloadTorBinaryX86') {
-	src "$torBinaryDir/tor_x86.zip"
-	algorithm 'SHA-256'
-	checksum 'f5308aff8303daca082f82227d02b51ddedba4ab1d1420739ada0427ae5dbb41'
-}
-
-task verifyTorBinaryX86Pie(type: Verify, dependsOn: 'downloadTorBinaryX86Pie') {
-	src "$torBinaryDir/tor_x86_pie.zip"
-	algorithm 'SHA-256'
-	checksum '889a6c81ac73d05d35ed610ca5a913cee44d333e4ae1749c2a107f2f7dd8197b'
+def verifyBinary(name, chksum) {
+	return tasks.create([
+			name     : "verifyBinary${name}",
+			type     : Verify,
+			dependsOn: downloadBinary(name)]) {
+		src "${torBinaryDir}/${name}.zip"
+		algorithm 'SHA-256'
+		checksum chksum
+	}
 }
 
 project.afterEvaluate {
-	preBuild.dependsOn {
-		[
-				'verifyTorGeoIp',
-				'verifyTorBinaryArm',
-				'verifyTorBinaryArmPie',
-				'verifyTorBinaryX86',
-				'verifyTorBinaryX86Pie'
-		]
+	torBinaries.every { key, value ->
+		preBuild.dependsOn.add(verifyBinary(key, value))
 	}
 }

bramble-android/proguard-rules.txt

@@ -8,6 +8,8 @@
 -dontwarn dagger.**
 -dontnote dagger.**
 
+-keep class net.i2p.crypto.eddsa.** { *; }
+
 -dontwarn sun.misc.Unsafe
 -dontnote com.google.common.**
 

bramble-android/src/main/AndroidManifest.xml

@@ -11,8 +11,6 @@
 	<uses-permission android:name="android.permission.INTERNET"/>
 	<uses-permission android:name="android.permission.READ_LOGS"/>
 	<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:allowBackup="false"

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

@@ -39,13 +39,13 @@ public class AndroidPluginModule {
 			EventBus eventBus) {
 		Context appContext = app.getApplicationContext();
 		DuplexPluginFactory bluetooth = new DroidtoothPluginFactory(ioExecutor,
-				androidExecutor, appContext, random, backoffFactory);
+				androidExecutor, appContext, random, eventBus, backoffFactory);
 		DuplexPluginFactory tor = new TorPluginFactory(ioExecutor, appContext,
 				locationUtils, reporter, eventBus, torSocketFactory,
 				backoffFactory);
 		DuplexPluginFactory lan = new AndroidLanTcpPluginFactory(ioExecutor,
 				backoffFactory, appContext);
-		final Collection<DuplexPluginFactory> duplex =
+		Collection<DuplexPluginFactory> duplex =
 				Arrays.asList(bluetooth, tor, lan);
 		@NotNullByDefault
 		PluginConfig pluginConfig = new PluginConfig() {

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

@@ -11,8 +11,9 @@ 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;
@@ -23,6 +24,8 @@ 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;
@@ -30,23 +33,14 @@ 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;
 
@@ -61,8 +55,6 @@ 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;
@@ -75,14 +67,10 @@ import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-class DroidtoothPlugin implements DuplexPlugin {
+class DroidtoothPlugin implements DuplexPlugin, EventListener {
 
 	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;
@@ -136,12 +124,7 @@ class DroidtoothPlugin implements DuplexPlugin {
 		// with a message queue, so submit it to the AndroidExecutor
 		try {
 			adapter = androidExecutor.runOnBackgroundThread(
-					new Callable<BluetoothAdapter>() {
-						@Override
-						public BluetoothAdapter call() throws Exception {
-							return BluetoothAdapter.getDefaultAdapter();
-						}
-					}).get();
+					BluetoothAdapter::getDefaultAdapter).get();
 		} catch (InterruptedException e) {
 			Thread.currentThread().interrupt();
 			LOG.warning("Interrupted while getting BluetoothAdapter");
@@ -166,9 +149,7 @@ class DroidtoothPlugin implements DuplexPlugin {
 		} else {
 			// Enable Bluetooth if settings allow
 			if (callback.getSettings().getBoolean(PREF_BT_ENABLE, false)) {
-				wasEnabledByUs = true;
-				if (adapter.enable()) LOG.info("Enabling Bluetooth");
-				else LOG.info("Could not enable Bluetooth");
+				enableAdapter();
 			} else {
 				LOG.info("Not enabling Bluetooth");
 			}
@@ -176,40 +157,36 @@ class DroidtoothPlugin implements DuplexPlugin {
 	}
 
 	private void bind() {
-		ioExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				if (!isRunning()) return;
-				String address = AndroidUtils.getBluetoothAddress(appContext,
-						adapter);
-				if (LOG.isLoggable(INFO))
-					LOG.info("Local address " + scrubMacAddress(address));
-				if (!StringUtils.isNullOrEmpty(address)) {
-					// Advertise the Bluetooth address to contacts
-					TransportProperties p = new TransportProperties();
-					p.put(PROP_ADDRESS, address);
-					callback.mergeLocalProperties(p);
-				}
-				// Bind a server socket to accept connections from contacts
-				BluetoothServerSocket ss;
-				try {
-					ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
-							"RFCOMM", getUuid());
-				} catch (IOException e) {
-					if (LOG.isLoggable(WARNING))
-						LOG.log(WARNING, e.toString(), e);
-					return;
-				}
-				if (!isRunning()) {
-					tryToClose(ss);
-					return;
-				}
-				LOG.info("Socket bound");
-				socket = ss;
-				backoff.reset();
-				callback.transportEnabled();
-				acceptContactConnections();
+		ioExecutor.execute(() -> {
+			if (!isRunning()) return;
+			String address = AndroidUtils.getBluetoothAddress(appContext,
+					adapter);
+			if (LOG.isLoggable(INFO))
+				LOG.info("Local address " + scrubMacAddress(address));
+			if (!StringUtils.isNullOrEmpty(address)) {
+				// Advertise the Bluetooth address to contacts
+				TransportProperties p = new TransportProperties();
+				p.put(PROP_ADDRESS, address);
+				callback.mergeLocalProperties(p);
 			}
+			// Bind a server socket to accept connections from contacts
+			BluetoothServerSocket ss;
+			try {
+				ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
+						"RFCOMM", getUuid());
+			} catch (IOException e) {
+				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+				return;
+			}
+			if (!isRunning()) {
+				tryToClose(ss);
+				return;
+			}
+			LOG.info("Socket bound");
+			socket = ss;
+			backoff.reset();
+			callback.transportEnabled();
+			acceptContactConnections();
 		});
 	}
 
@@ -259,13 +236,27 @@ class DroidtoothPlugin implements DuplexPlugin {
 		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);
-		// Disable Bluetooth if we enabled it and it's still enabled
-		if (wasEnabledByUs && adapter.isEnabled()) {
+		disableAdapter();
+	}
+
+	private void disableAdapter() {
+		if (adapter != null && adapter.isEnabled() && wasEnabledByUs) {
 			if (adapter.disable()) LOG.info("Disabling Bluetooth");
 			else LOG.info("Could not disable Bluetooth");
 		}
@@ -294,21 +285,18 @@ class DroidtoothPlugin implements DuplexPlugin {
 		Map<ContactId, TransportProperties> remote =
 				callback.getRemoteProperties();
 		for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {
-			final ContactId c = e.getKey();
+			ContactId c = e.getKey();
 			if (connected.contains(c)) continue;
-			final String address = e.getValue().get(PROP_ADDRESS);
+			String address = e.getValue().get(PROP_ADDRESS);
 			if (StringUtils.isNullOrEmpty(address)) continue;
-			final String uuid = e.getValue().get(PROP_UUID);
+			String uuid = e.getValue().get(PROP_UUID);
 			if (StringUtils.isNullOrEmpty(uuid)) continue;
-			ioExecutor.execute(new Runnable() {
-				@Override
-				public void run() {
-					if (!running) return;
-					BluetoothSocket s = connect(address, uuid);
-					if (s != null) {
-						backoff.reset();
-						callback.outgoingConnectionCreated(c, wrapSocket(s));
-					}
+			ioExecutor.execute(() -> {
+				if (!running) return;
+				BluetoothSocket s = connect(address, uuid);
+				if (s != null) {
+					backoff.reset();
+					callback.outgoingConnectionCreated(c, wrapSocket(s));
 				}
 			});
 		}
@@ -363,8 +351,7 @@ class DroidtoothPlugin implements DuplexPlugin {
 	@Override
 	public DuplexTransportConnection createConnection(ContactId c) {
 		if (!isRunning()) return null;
-		TransportProperties p = callback.getRemoteProperties().get(c);
-		if (p == null) return null;
+		TransportProperties p = callback.getRemoteProperties(c);
 		String address = p.get(PROP_ADDRESS);
 		if (StringUtils.isNullOrEmpty(address)) return null;
 		String uuid = p.get(PROP_UUID);
@@ -374,90 +361,6 @@ class DroidtoothPlugin implements DuplexPlugin {
 		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;
@@ -472,7 +375,7 @@ class DroidtoothPlugin implements DuplexPlugin {
 		// 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 invitation connections
+		// Bind a server socket for receiving key agreement connections
 		BluetoothServerSocket ss;
 		try {
 			ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
@@ -513,6 +416,23 @@ class DroidtoothPlugin implements DuplexPlugin {
 		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(this::enableAdapter);
+	}
+
+	private void disableAdapterAsync() {
+		ioExecutor.execute(this::disableAdapter);
+	}
+
 	private class BluetoothStateReceiver extends BroadcastReceiver {
 
 		@Override
@@ -536,115 +456,6 @@ class DroidtoothPlugin implements DuplexPlugin {
 		}
 	}
 
-	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;
@@ -657,16 +468,13 @@ class DroidtoothPlugin implements DuplexPlugin {
 
 		@Override
 		public Callable<KeyAgreementConnection> listen() {
-			return new Callable<KeyAgreementConnection>() {
-				@Override
-				public KeyAgreementConnection call() throws IOException {
-					BluetoothSocket s = ss.accept();
-					if (LOG.isLoggable(INFO))
-						LOG.info(ID.getString() + ": Incoming connection");
-					return new KeyAgreementConnection(
-							new DroidtoothTransportConnection(
-									DroidtoothPlugin.this, s), ID);
-				}
+			return () -> {
+				BluetoothSocket s = ss.accept();
+				if (LOG.isLoggable(INFO))
+					LOG.info(ID.getString() + ": Incoming connection");
+				return new KeyAgreementConnection(
+						new DroidtoothTransportConnection(
+								DroidtoothPlugin.this, s), ID);
 			};
 		}
 

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

@@ -2,6 +2,7 @@ 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;
@@ -31,15 +32,18 @@ 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, BackoffFactory backoffFactory) {
+			SecureRandom secureRandom, EventBus eventBus,
+			BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
 		this.androidExecutor = androidExecutor;
 		this.appContext = appContext;
 		this.secureRandom = secureRandom;
+		this.eventBus = eventBus;
 		this.backoffFactory = backoffFactory;
 	}
 
@@ -57,7 +61,10 @@ public class DroidtoothPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(DuplexPluginCallback callback) {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		return new DroidtoothPlugin(ioExecutor, androidExecutor, appContext,
-				secureRandom, backoff, callback, MAX_LATENCY);
+		DroidtoothPlugin plugin = new DroidtoothPlugin(ioExecutor,
+				androidExecutor, appContext, secureRandom, backoff, callback,
+				MAX_LATENCY);
+		eventBus.addListener(plugin);
+		return plugin;
 	}
 }

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

@@ -17,7 +17,6 @@ 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;
@@ -56,6 +55,7 @@ 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"
 	};
@@ -149,7 +149,8 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		cookieFile = new File(torDirectory, ".tor/control_auth_cookie");
 		Object o = appContext.getSystemService(POWER_SERVICE);
 		PowerManager pm = (PowerManager) o;
-		wakeLock = pm.newWakeLock(PARTIAL_WAKE_LOCK, "TorPlugin");
+		// This tag will prevent Huawei's powermanager from killing us.
+		wakeLock = pm.newWakeLock(PARTIAL_WAKE_LOCK, "LocationManagerService");
 		wakeLock.setReferenceCounted(false);
 	}
 
@@ -369,57 +370,45 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void sendDevReports() {
-		ioExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				// TODO: Trigger this with a TransportEnabledEvent
-				File reportDir = AndroidUtils.getReportDir(appContext);
-				reporter.sendReports(reportDir);
-			}
+		ioExecutor.execute(() -> {
+			// TODO: Trigger this with a TransportEnabledEvent
+			File reportDir = AndroidUtils.getReportDir(appContext);
+			reporter.sendReports(reportDir);
 		});
 	}
 
 	private void bind() {
-		ioExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				// If there's already a port number stored in config, reuse it
-				String portString = callback.getSettings().get(PREF_TOR_PORT);
-				int port;
-				if (StringUtils.isNullOrEmpty(portString)) port = 0;
-				else port = Integer.parseInt(portString);
-				// Bind a server socket to receive connections from Tor
-				ServerSocket ss = null;
-				try {
-					ss = new ServerSocket();
-					ss.bind(new InetSocketAddress("127.0.0.1", port));
-				} catch (IOException e) {
-					if (LOG.isLoggable(WARNING))
-						LOG.log(WARNING, e.toString(), e);
-					tryToClose(ss);
-					return;
-				}
-				if (!running) {
-					tryToClose(ss);
-					return;
-				}
-				socket = ss;
-				// Store the port number
-				final String localPort = String.valueOf(ss.getLocalPort());
-				Settings s = new Settings();
-				s.put(PREF_TOR_PORT, localPort);
-				callback.mergeSettings(s);
-				// Create a hidden service if necessary
-				ioExecutor.execute(new Runnable() {
-					@Override
-					public void run() {
-						publishHiddenService(localPort);
-					}
-				});
-				backoff.reset();
-				// Accept incoming hidden service connections from Tor
-				acceptContactConnections(ss);
+		ioExecutor.execute(() -> {
+			// If there's already a port number stored in config, reuse it
+			String portString = callback.getSettings().get(PREF_TOR_PORT);
+			int port;
+			if (StringUtils.isNullOrEmpty(portString)) port = 0;
+			else port = Integer.parseInt(portString);
+			// Bind a server socket to receive connections from Tor
+			ServerSocket ss = null;
+			try {
+				ss = new ServerSocket();
+				ss.bind(new InetSocketAddress("127.0.0.1", port));
+			} catch (IOException e) {
+				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+				tryToClose(ss);
+				return;
 			}
+			if (!running) {
+				tryToClose(ss);
+				return;
+			}
+			socket = ss;
+			// Store the port number
+			String localPort = String.valueOf(ss.getLocalPort());
+			Settings s = new Settings();
+			s.put(PREF_TOR_PORT, localPort);
+			callback.mergeSettings(s);
+			// Create a hidden service if necessary
+			ioExecutor.execute(() -> publishHiddenService(localPort));
+			backoff.reset();
+			// Accept incoming hidden service connections from Tor
+			acceptContactConnections(ss);
 		});
 	}
 
@@ -539,20 +528,21 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	public void poll(Collection<ContactId> connected) {
 		if (!isRunning()) return;
 		backoff.increment();
-		// TODO: Pass properties to connectAndCallBack()
-		for (ContactId c : callback.getRemoteProperties().keySet())
-			if (!connected.contains(c)) connectAndCallBack(c);
+		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());
+		}
 	}
 
-	private void connectAndCallBack(final ContactId c) {
-		ioExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				DuplexTransportConnection d = createConnection(c);
-				if (d != null) {
-					backoff.reset();
-					callback.outgoingConnectionCreated(c, d);
-				}
+	private void connectAndCallBack(ContactId c, TransportProperties p) {
+		ioExecutor.execute(() -> {
+			if (!isRunning()) return;
+			DuplexTransportConnection d = createConnection(p);
+			if (d != null) {
+				backoff.reset();
+				callback.outgoingConnectionCreated(c, d);
 			}
 		});
 	}
@@ -560,8 +550,11 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public DuplexTransportConnection createConnection(ContactId c) {
 		if (!isRunning()) return null;
-		TransportProperties p = callback.getRemoteProperties().get(c);
-		if (p == null) return null;
+		return createConnection(callback.getRemoteProperties(c));
+	}
+
+	@Nullable
+	private DuplexTransportConnection createConnection(TransportProperties p) {
 		String onion = p.get(PROP_ONION);
 		if (StringUtils.isNullOrEmpty(onion)) return null;
 		if (!ONION.matcher(onion).matches()) {
@@ -589,17 +582,6 @@ 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;
@@ -693,48 +675,43 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void updateConnectionStatus() {
-		ioExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				if (!running) return;
+		ioExecutor.execute(() -> {
+			if (!running) return;
 
-				Object o = appContext.getSystemService(CONNECTIVITY_SERVICE);
-				ConnectivityManager cm = (ConnectivityManager) o;
-				NetworkInfo net = cm.getActiveNetworkInfo();
-				boolean online = net != null && net.isConnected();
-				boolean wifi = online && net.getType() == TYPE_WIFI;
-				String country = locationUtils.getCurrentCountry();
-				boolean blocked = TorNetworkMetadata.isTorProbablyBlocked(
-						country);
-				Settings s = callback.getSettings();
-				int network = s.getInt(PREF_TOR_NETWORK,
-						PREF_TOR_NETWORK_ALWAYS);
+			Object o = appContext.getSystemService(CONNECTIVITY_SERVICE);
+			ConnectivityManager cm = (ConnectivityManager) o;
+			NetworkInfo net = cm.getActiveNetworkInfo();
+			boolean online = net != null && net.isConnected();
+			boolean wifi = online && net.getType() == TYPE_WIFI;
+			String country = locationUtils.getCurrentCountry();
+			boolean blocked = TorNetworkMetadata.isTorProbablyBlocked(
+					country);
+			Settings s = callback.getSettings();
+			int network = s.getInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_ALWAYS);
 
-				if (LOG.isLoggable(INFO)) {
-					LOG.info("Online: " + online + ", wifi: " + wifi);
-					if ("".equals(country)) LOG.info("Country code unknown");
-					else LOG.info("Country code: " + country);
-				}
-
-				try {
-					if (!online) {
-						LOG.info("Disabling network, device is offline");
-						enableNetwork(false);
-					} else if (blocked) {
-						LOG.info("Disabling network, country is blocked");
-						enableNetwork(false);
-					} else if (network == PREF_TOR_NETWORK_NEVER
-							|| (network == PREF_TOR_NETWORK_WIFI && !wifi)) {
-						LOG.info("Disabling network due to data setting");
-						enableNetwork(false);
-					} else {
-						LOG.info("Enabling network");
-						enableNetwork(true);
-					}
-				} catch (IOException e) {
-					if (LOG.isLoggable(WARNING))
-						LOG.log(WARNING, e.toString(), e);
+			if (LOG.isLoggable(INFO)) {
+				LOG.info("Online: " + online + ", wifi: " + wifi);
+				if ("".equals(country)) LOG.info("Country code unknown");
+				else LOG.info("Country code: " + country);
+			}
+
+			try {
+				if (!online) {
+					LOG.info("Disabling network, device is offline");
+					enableNetwork(false);
+				} else if (blocked) {
+					LOG.info("Disabling network, country is blocked");
+					enableNetwork(false);
+				} else if (network == PREF_TOR_NETWORK_NEVER
+						|| (network == PREF_TOR_NETWORK_WIFI && !wifi)) {
+					LOG.info("Disabling network due to data setting");
+					enableNetwork(false);
+				} else {
+					LOG.info("Enabling network");
+					enableNetwork(true);
 				}
+			} catch (IOException e) {
+				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			}
 		});
 	}

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

@@ -3,6 +3,7 @@ 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;
@@ -21,12 +22,12 @@ class TorTransportConnection extends AbstractDuplexTransportConnection {
 
 	@Override
 	protected InputStream getInputStream() throws IOException {
-		return socket.getInputStream();
+		return IoUtils.getInputStream(socket);
 	}
 
 	@Override
 	protected OutputStream getOutputStream() throws IOException {
-		return socket.getOutputStream();
+		return IoUtils.getOutputStream(socket);
 	}
 
 	@Override

bramble-android/src/main/java/org/briarproject/bramble/system/AndroidExecutorImpl.java

@@ -27,14 +27,11 @@ class AndroidExecutorImpl implements AndroidExecutor {
 	@Inject
 	AndroidExecutorImpl(Application app) {
 		uiHandler = new Handler(app.getApplicationContext().getMainLooper());
-		loop = new Runnable() {
-			@Override
-			public void run() {
-				Looper.prepare();
-				backgroundHandler = new Handler();
-				startLatch.countDown();
-				Looper.loop();
-			}
+		loop = () -> {
+			Looper.prepare();
+			backgroundHandler = new Handler();
+			startLatch.countDown();
+			Looper.loop();
 		};
 	}
 

bramble-api/build.gradle

@@ -1,30 +1,39 @@
-apply plugin: 'java'
-sourceCompatibility = 1.6
-targetCompatibility = 1.6
+apply plugin: 'java-library'
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
 
 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'
+	implementation "com.google.dagger:dagger:2.0.2"
+	implementation 'com.google.code.findbugs:jsr305:3.0.2'
 
-	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.hamcrest:hamcrest-library:1.3"
-	testCompile "org.hamcrest:hamcrest-core:1.3"
+	testImplementation 'junit:junit:4.12'
+	testImplementation "org.jmock:jmock:2.8.2"
+	testImplementation "org.jmock:jmock-junit4:2.8.2"
+	testImplementation "org.jmock:jmock-legacy:2.8.2"
+	testImplementation "org.hamcrest:hamcrest-library:1.3"
+	testImplementation "org.hamcrest:hamcrest-core:1.3"
 }
 
 dependencyVerification {
 	verify = [
-			'com.google.dagger:dagger:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
-			'com.google.dagger:dagger-compiler:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
-			'com.google.code.findbugs:jsr305:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
-			'javax.inject:javax.inject:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
-			'com.google.dagger:dagger-producers:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
-			'com.google.guava:guava:d664fbfc03d2e5ce9cab2a44fb01f1d0bf9dfebeccc1a473b1f9ea31f79f6f99',
+			'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+			'com.google.dagger:dagger:2.0.2:dagger-2.0.2.jar:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
+			'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
+			'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
+			'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
+			'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
+			'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
+			'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
+			'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
+			'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
+			'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
+			'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
+			'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
+			'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
+			'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
 	]
 }
 
@@ -39,3 +48,8 @@ task jarTest(type: Jar, dependsOn: testClasses) {
 artifacts {
 	testOutput jarTest
 }
+
+// If a Java 6 JRE is available, check we're not using any Java 7 or 8 APIs
+tasks.withType(JavaCompile) {
+	useJava6StandardLibrary(it)
+}

bramble-api/src/main/java/org/briarproject/bramble/api/client/BdfMessageContext.java

@@ -23,7 +23,7 @@ public class BdfMessageContext {
 	}
 
 	public BdfMessageContext(BdfDictionary dictionary) {
-		this(dictionary, Collections.<MessageId>emptyList());
+		this(dictionary, Collections.emptyList());
 	}
 
 	public BdfDictionary getDictionary() {

bramble-api/src/main/java/org/briarproject/bramble/api/client/ContactGroupFactory.java

@@ -12,18 +12,19 @@ public interface ContactGroupFactory {
 	/**
 	 * Creates a group that is not shared with any contacts.
 	 */
-	Group createLocalGroup(ClientId clientId);
+	Group createLocalGroup(ClientId clientId, int clientVersion);
 
 	/**
 	 * Creates a group for the given client to share with the given contact.
 	 */
-	Group createContactGroup(ClientId clientId, Contact contact);
+	Group createContactGroup(ClientId clientId, int clientVersion,
+			Contact contact);
 
 	/**
 	 * Creates a group for the given client to share between the given authors
 	 * identified by their AuthorIds.
 	 */
-	Group createContactGroup(ClientId clientId, AuthorId authorId1,
-			AuthorId authorId2);
+	Group createContactGroup(ClientId clientId, int clientVersion,
+			AuthorId authorId1, AuthorId authorId2);
 
 }

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

@@ -12,6 +12,32 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 @NotNullByDefault
 public interface ContactExchangeTask {
 
+	/**
+	 * The current version of the contact exchange protocol
+	 */
+	int PROTOCOL_VERSION = 0;
+
+	/**
+	 * Label for deriving Alice's header key from the master secret.
+	 */
+	String ALICE_KEY_LABEL =
+			"org.briarproject.bramble.contact/ALICE_HEADER_KEY";
+
+	/**
+	 * Label for deriving Bob's header key from the master secret.
+	 */
+	String BOB_KEY_LABEL = "org.briarproject.bramble.contact/BOB_HEADER_KEY";
+
+	/**
+	 * Label for deriving Alice's key binding nonce from the master secret.
+	 */
+	String ALICE_NONCE_LABEL = "org.briarproject.bramble.contact/ALICE_NONCE";
+
+	/**
+	 * Label for deriving Bob's key binding nonce from the master secret.
+	 */
+	String BOB_NONCE_LABEL = "org.briarproject.bramble.contact/BOB_NONCE";
+
 	/**
 	 * Exchanges contact information with a remote peer.
 	 */

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

@@ -1,8 +1,5 @@
 package org.briarproject.bramble.api.crypto;
 
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.transport.TransportKeys;
-
 import java.security.GeneralSecurityException;
 import java.security.SecureRandom;
 
@@ -10,8 +7,6 @@ public interface CryptoComponent {
 
 	SecretKey generateSecretKey();
 
-	PseudoRandom getPseudoRandom(int seed1, int seed2);
-
 	SecureRandom getSecureRandom();
 
 	KeyPair generateAgreementKeyPair();
@@ -22,165 +17,98 @@ public interface CryptoComponent {
 
 	KeyParser getSignatureKeyParser();
 
+	KeyPair generateEdKeyPair();
+
+	KeyParser getEdKeyParser();
+
 	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.
-	 */
-	SecretKey deriveHeaderKey(SecretKey master, boolean alice);
-
-	/**
-	 * Derives a message authentication code key from the given master secret.
-	 * @param alice whether the key is for use by Alice or Bob.
-	 */
-	SecretKey deriveMacKey(SecretKey master, boolean alice);
-
-	/**
-	 * Derives a nonce from the given master secret for one of the parties to
-	 * sign.
-	 * @param alice whether the nonce is for use by Alice or Bob.
-	 */
-	byte[] deriveSignatureNonce(SecretKey master, boolean alice);
-
-	/**
-	 * Derives a commitment to the provided public key.
-	 * <p/>
-	 * Part of BQP.
+	 * Derives another secret key from the given secret key.
 	 *
-	 * @param publicKey the public key
-	 * @return the commitment to the provided public key.
+	 * @param label a namespaced label indicating the purpose of the derived
+	 * key, to prevent it from being repurposed or colliding with a key derived
+	 * for another purpose
 	 */
-	byte[] deriveKeyCommitment(byte[] publicKey);
+	SecretKey deriveKey(String label, SecretKey k, byte[]... inputs);
 
 	/**
 	 * Derives a common shared secret from two public keys and one of the
 	 * corresponding private keys.
-	 * <p/>
-	 * Part of BQP.
 	 *
-	 * @param theirPublicKey the ephemeral public key of the remote party
-	 * @param ourKeyPair our ephemeral keypair
-	 * @param alice true if ourKeyPair belongs to Alice
+	 * @param label a namespaced label indicating the purpose of this shared
+	 * secret, to prevent it from being repurposed or colliding with a shared
+	 * secret derived for another purpose
+	 * @param theirPublicKey the public key of the remote party
+	 * @param ourKeyPair the key pair of the local party
 	 * @return the shared secret
-	 * @throws GeneralSecurityException
 	 */
-	SecretKey deriveSharedSecret(byte[] theirPublicKey, KeyPair ourKeyPair,
-			boolean alice) throws GeneralSecurityException;
+	SecretKey deriveSharedSecret(String label, PublicKey theirPublicKey,
+			KeyPair ourKeyPair, byte[]... inputs)
+			throws GeneralSecurityException;
 
 	/**
-	 * Derives the content of a confirmation record.
-	 * <p/>
-	 * Part of BQP.
+	 * Signs the given byte[] with the given ECDSA private key.
 	 *
-	 * @param sharedSecret the common shared secret
-	 * @param theirPayload the commit payload from the remote party
-	 * @param ourPayload the commit payload we sent
-	 * @param theirPublicKey the ephemeral public key of the remote party
-	 * @param ourKeyPair our ephemeral keypair
-	 * @param alice true if ourKeyPair belongs to Alice
-	 * @param aliceRecord true if the confirmation record is for use by Alice
-	 * @return the confirmation record
-	 */
-	byte[] deriveConfirmationRecord(SecretKey sharedSecret,
-			byte[] theirPayload, byte[] ourPayload,
-			byte[] theirPublicKey, KeyPair ourKeyPair,
-			boolean alice, boolean aliceRecord);
-
-	/**
-	 * Derives a master secret from the given shared secret.
-	 * <p/>
-	 * Part of BQP.
-	 *
-	 * @param sharedSecret the common shared secret
-	 * @return the master secret
-	 */
-	SecretKey deriveMasterSecret(SecretKey sharedSecret);
-
-	/**
-	 * Derives a master secret from two public keys and one of the corresponding
-	 * private keys.
-	 * <p/>
-	 * This is a helper method that calls
-	 * deriveMasterSecret(deriveSharedSecret(theirPublicKey, ourKeyPair, alice))
-	 *
-	 * @param theirPublicKey the ephemeral public key of the remote party
-	 * @param ourKeyPair our ephemeral keypair
-	 * @param alice true if ourKeyPair belongs to Alice
-	 * @return the shared secret
-	 * @throws GeneralSecurityException
-	 */
-	SecretKey deriveMasterSecret(byte[] theirPublicKey, KeyPair ourKeyPair,
-			boolean alice) throws GeneralSecurityException;
-
-	/**
-	 * Derives initial transport keys for the given transport in the given
-	 * rotation period from the given master secret.
-	 * @param alice whether the keys are for use by Alice or Bob.
-	 */
-	TransportKeys deriveTransportKeys(TransportId t, SecretKey master,
-			long rotationPeriod, boolean alice);
-
-	/**
-	 * Rotates the given transport keys to the given rotation period. If the
-	 * keys are for a future rotation period they are not rotated.
-	 */
-	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);
-
-	/**
-	 * Signs the given byte[] with the given PrivateKey.
-	 *
-	 * @param label A label specific to this signature
-	 *              to ensure that the signature cannot be repurposed
+	 * @param label a namespaced label indicating the purpose of this
+	 * signature, to prevent it from being repurposed or colliding with a
+	 * signature created for another purpose
 	 */
 	byte[] sign(String label, byte[] toSign, byte[] privateKey)
 			throws GeneralSecurityException;
 
 	/**
-	 * Verifies that the given signature is valid for the signedData
-	 * and the given publicKey.
+	 * Signs the given byte[] with the given Ed25519 private key.
 	 *
-	 * @param label A label that was specific to this signature
+	 * @param label A label specific to this signature
 	 *              to ensure that the signature cannot be repurposed
+	 */
+	byte[] signEd(String label, byte[] toSign, byte[] privateKey)
+			throws GeneralSecurityException;
+
+	/**
+	 * Verifies that the given signature is valid for the signed data
+	 * and the given ECDSA public key.
+	 *
+	 * @param label a namespaced label indicating the purpose of this
+	 * signature, to prevent it from being repurposed or colliding with a
+	 * signature created for another purpose
 	 * @return true if the signature was valid, false otherwise.
 	 */
 	boolean verify(String label, byte[] signedData, byte[] publicKey,
 			byte[] signature) throws GeneralSecurityException;
 
+	/**
+	 * Verifies that the given signature is valid for the signed data
+	 * and the given Ed25519 public key.
+	 *
+	 * @param label A label that was specific to this signature
+	 *              to ensure that the signature cannot be repurposed
+	 * @return true if the signature was valid, false otherwise.
+	 */
+	boolean verifyEd(String label, byte[] signedData, byte[] publicKey,
+			byte[] signature) throws GeneralSecurityException;
+
 	/**
 	 * Returns the hash of the given inputs. The inputs are unambiguously
 	 * combined by prefixing each input with its length.
 	 *
-	 * @param label A label specific to this hash to ensure that hashes
-	 *              calculated for distinct purposes don't collide.
+	 * @param label a namespaced label indicating the purpose of this hash, to
+	 * prevent it from being repurposed or colliding with a hash created for
+	 * another purpose
 	 */
 	byte[] hash(String label, byte[]... inputs);
 
-	/**
-	 * Returns the length of hashes produced by
-	 * the {@link CryptoComponent#hash(String, byte[]...)} method.
-	 */
-	int getHashLength();
-
 	/**
 	 * Returns a message authentication code with the given key over the
 	 * given inputs. The inputs are unambiguously combined by prefixing each
 	 * input with its length.
+	 *
+	 * @param label a namespaced label indicating the purpose of this MAC, to
+	 * prevent it from being repurposed or colliding with a MAC created for
+	 * another purpose
 	 */
-	byte[] mac(SecretKey macKey, byte[]... inputs);
+	byte[] mac(String label, SecretKey macKey, byte[]... inputs);
 
 	/**
 	 * Encrypts and authenticates the given plaintext so it can be written to

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

@@ -0,0 +1,50 @@
+package org.briarproject.bramble.api.crypto;
+
+/**
+ * Crypto operations for the key agreement protocol - see
+ * https://code.briarproject.org/akwizgran/briar-spec/blob/master/protocols/BQP.md
+ */
+public interface KeyAgreementCrypto {
+
+	/**
+	 * Hash label for public key commitment.
+	 */
+	String COMMIT_LABEL = "org.briarproject.bramble.keyagreement/COMMIT";
+
+	/**
+	 * Key derivation label for confirmation record.
+	 */
+	String CONFIRMATION_KEY_LABEL =
+			"org.briarproject.bramble.keyagreement/CONFIRMATION_KEY";
+
+	/**
+	 * MAC label for confirmation record.
+	 */
+	String CONFIRMATION_MAC_LABEL =
+			"org.briarproject.bramble.keyagreement/CONFIRMATION_MAC";
+
+	/**
+	 * Derives a commitment to the provided public key.
+	 *
+	 * @param publicKey the public key
+	 * @return the commitment to the provided public key.
+	 */
+	byte[] deriveKeyCommitment(PublicKey publicKey);
+
+	/**
+	 * Derives the content of a confirmation record.
+	 *
+	 * @param sharedSecret the common shared secret
+	 * @param theirPayload the key exchange payload of the remote party
+	 * @param ourPayload the key exchange payload of the local party
+	 * @param theirPublicKey the ephemeral public key of the remote party
+	 * @param ourKeyPair our ephemeral key pair of the local party
+	 * @param alice true if the local party is Alice
+	 * @param aliceRecord true if the confirmation record is for use by Alice
+	 * @return the confirmation record
+	 */
+	byte[] deriveConfirmationRecord(SecretKey sharedSecret,
+			byte[] theirPayload, byte[] ourPayload,
+			PublicKey theirPublicKey, KeyPair ourKeyPair,
+			boolean alice, boolean aliceRecord);
+}

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

@@ -1,12 +0,0 @@
-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

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

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

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

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

@@ -0,0 +1,32 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.TransportKeys;
+
+/**
+ * Crypto operations for the transport security protocol - see
+ * https://code.briarproject.org/akwizgran/briar-spec/blob/master/protocols/BTP.md
+ */
+public interface TransportCrypto {
+
+	/**
+	 * Derives initial transport keys for the given transport in the given
+	 * rotation period from the given master secret.
+	 *
+	 * @param alice whether the keys are for use by Alice or Bob.
+	 */
+	TransportKeys deriveTransportKeys(TransportId t, SecretKey master,
+			long rotationPeriod, boolean alice);
+
+	/**
+	 * Rotates the given transport keys to the given rotation period. If the
+	 * keys are for the given period or any later period they are not rotated.
+	 */
+	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);
+}

bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfDictionary.java

@@ -4,11 +4,14 @@ import org.briarproject.bramble.api.Bytes;
 import org.briarproject.bramble.api.FormatException;
 
 import java.util.Map;
-import java.util.concurrent.ConcurrentSkipListMap;
+import java.util.Map.Entry;
+import java.util.TreeMap;
 
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.NotThreadSafe;
 
-public class BdfDictionary extends ConcurrentSkipListMap<String, Object> {
+@NotThreadSafe
+public class BdfDictionary extends TreeMap<String, Object> {
 
 	public static final Object NULL_VALUE = new Object();
 

bramble-api/src/main/java/org/briarproject/bramble/api/data/BdfList.java

@@ -3,15 +3,17 @@ package org.briarproject.bramble.api.data;
 import org.briarproject.bramble.api.Bytes;
 import org.briarproject.bramble.api.FormatException;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Vector;
 
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.NotThreadSafe;
 
 import static org.briarproject.bramble.api.data.BdfDictionary.NULL_VALUE;
 
-public class BdfList extends Vector<Object> {
+@NotThreadSafe
+public class BdfList extends ArrayList<Object> {
 
 	/**
 	 * Factory method for constructing lists inline.

bramble-api/src/main/java/org/briarproject/bramble/api/db/DatabaseComponent.java

@@ -122,8 +122,9 @@ public interface DatabaseComponent {
 			throws DbException;
 
 	/**
-	 * Deletes the message with the given ID. The message ID and any other
-	 * associated data are not deleted.
+	 * Deletes the message with the given ID. Unlike
+	 * {@link #removeMessage(Transaction, MessageId)}, the message ID and any
+	 * other associated data are not deleted.
 	 */
 	void deleteMessage(Transaction txn, MessageId m) throws DbException;
 
@@ -452,6 +453,11 @@ public interface DatabaseComponent {
 	 */
 	void removeLocalAuthor(Transaction txn, AuthorId a) throws DbException;
 
+	/**
+	 * Removes a message (and all associated state) from the database.
+	 */
+	void removeMessage(Transaction txn, MessageId m) throws DbException;
+
 	/**
 	 * Removes a transport (and all associated state) from the database.
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/db/Metadata.java

@@ -1,11 +1,11 @@
 package org.briarproject.bramble.api.db;
 
-import java.util.Hashtable;
+import java.util.TreeMap;
 
-import javax.annotation.concurrent.ThreadSafe;
+import javax.annotation.concurrent.NotThreadSafe;
 
-@ThreadSafe
-public class Metadata extends Hashtable<String, byte[]> {
+@NotThreadSafe
+public class Metadata extends TreeMap<String, byte[]> {
 
 	/**
 	 * Special value to indicate that a key is being removed.

bramble-api/src/main/java/org/briarproject/bramble/api/db/Transaction.java

@@ -45,7 +45,7 @@ public class Transaction {
 	 * committed.
 	 */
 	public void attach(Event e) {
-		if (events == null) events = new ArrayList<Event>();
+		if (events == null) events = new ArrayList<>();
 		events.add(e);
 	}
 

bramble-api/src/main/java/org/briarproject/bramble/api/identity/AuthorId.java

@@ -16,7 +16,7 @@ public class AuthorId extends UniqueId {
 	/**
 	 * Label for hashing authors to calculate their identities.
 	 */
-	public static final String LABEL = "org.briarproject.bramble.AUTHOR_ID";
+	public static final String LABEL = "org.briarproject.bramble/AUTHOR_ID";
 
 	public AuthorId(byte[] id) {
 		super(id);

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

@@ -1,20 +0,0 @@
-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

@@ -1,47 +0,0 @@
-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

@@ -1,85 +0,0 @@
-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

@@ -1,38 +0,0 @@
-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

@@ -1,15 +0,0 @@
-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/keyagreement/KeyAgreementConstants.java

@@ -5,7 +5,7 @@ public interface KeyAgreementConstants {
 	/**
 	 * The current version of the BQP protocol.
 	 */
-	byte PROTOCOL_VERSION = 2;
+	byte PROTOCOL_VERSION = 3;
 
 	/**
 	 * The length of the record header in bytes.
@@ -22,7 +22,10 @@ public interface KeyAgreementConstants {
 	 */
 	int COMMIT_LENGTH = 16;
 
-	long CONNECTION_TIMEOUT = 20 * 1000; // Milliseconds
+	/**
+	 * The connection timeout in milliseconds.
+	 */
+	long CONNECTION_TIMEOUT = 20 * 1000;
 
 	/**
 	 * The transport identifier for Bluetooth.
@@ -33,4 +36,16 @@ public interface KeyAgreementConstants {
 	 * The transport identifier for LAN.
 	 */
 	int TRANSPORT_ID_LAN = 1;
+
+	/**
+	 * Label for deriving the shared secret.
+	 */
+	String SHARED_SECRET_LABEL =
+			"org.briarproject.bramble.keyagreement/SHARED_SECRET";
+
+	/**
+	 * Label for deriving the master secret.
+	 */
+	String MASTER_SECRET_LABEL =
+			"org.briarproject.bramble.keyagreement/MASTER_SECRET";
 }

bramble-api/src/main/java/org/briarproject/bramble/api/keyagreement/KeyAgreementTaskFactory.java

@@ -1,15 +0,0 @@
-package org.briarproject.bramble.api.keyagreement;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * Manages tasks for conducting key agreements with remote peers.
- */
-@NotNullByDefault
-public interface KeyAgreementTaskFactory {
-
-	/**
-	 * Gets the current key agreement task.
-	 */
-	KeyAgreementTask createTask();
-}

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

@@ -4,5 +4,10 @@ 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

@@ -29,6 +29,11 @@ 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

@@ -32,11 +32,6 @@ 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

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

@@ -1,7 +1,6 @@
 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;
@@ -23,20 +22,6 @@ 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

@@ -0,0 +1,15 @@
+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

@@ -0,0 +1,14 @@
+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

@@ -17,6 +17,11 @@ public interface TransportPropertyManager {
 	 */
 	ClientId CLIENT_ID = new ClientId("org.briarproject.briar.properties");
 
+	/**
+	 * The current version of the transport property client.
+	 */
+	int CLIENT_VERSION = 0;
+
 	/**
 	 * Stores the given properties received while adding a contact - they will
 	 * be superseded by any properties synced from the contact.
@@ -33,7 +38,7 @@ public interface TransportPropertyManager {
 	/**
 	 * Returns the local transport properties for all transports.
 	 * <br/>
-	 * Read-Only
+	 * TODO: Transaction can be read-only when code is simplified
 	 */
 	Map<TransportId, TransportProperties> getLocalProperties(Transaction txn)
 			throws DbException;
@@ -49,6 +54,13 @@ 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/sync/ClientId.java

@@ -36,4 +36,8 @@ public class ClientId implements Comparable<ClientId> {
 		return id.hashCode();
 	}
 
+	@Override
+	public String toString() {
+		return id;
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/GroupFactory.java

@@ -6,7 +6,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 public interface GroupFactory {
 
 	/**
-	 * Creates a group with the given client ID and descriptor.
+	 * Creates a group with the given client ID, client version and descriptor.
 	 */
-	Group createGroup(ClientId c, byte[] descriptor);
+	Group createGroup(ClientId c, int clientVersion, byte[] descriptor);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/sync/GroupId.java

@@ -15,7 +15,7 @@ public class GroupId extends UniqueId {
 	/**
 	 * Label for hashing groups to calculate their identifiers.
 	 */
-	public static final String LABEL = "org.briarproject.bramble.GROUP_ID";
+	public static final String LABEL = "org.briarproject.bramble/GROUP_ID";
 
 	public GroupId(byte[] id) {
 		super(id);

bramble-api/src/main/java/org/briarproject/bramble/api/sync/MessageContext.java

@@ -22,7 +22,7 @@ public class MessageContext {
 	}
 
 	public MessageContext(Metadata metadata) {
-		this(metadata, Collections.<MessageId>emptyList());
+		this(metadata, Collections.emptyList());
 	}
 
 	public Metadata getMetadata() {

bramble-api/src/main/java/org/briarproject/bramble/api/sync/MessageId.java

@@ -16,7 +16,7 @@ public class MessageId extends UniqueId {
 	/**
 	 * Label for hashing messages to calculate their identifiers.
 	 */
-	public static final String LABEL = "org.briarproject.bramble.MESSAGE_ID";
+	public static final String LABEL = "org.briarproject.bramble/MESSAGE_ID";
 
 	public MessageId(byte[] id) {
 		super(id);

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 an
-	 * invitation stream.
+	 * Creates an {@link InputStream InputStream} for reading from a contact
+	 * exchangestream.
 	 */
-	InputStream createInvitationStreamReader(InputStream in,
+	InputStream createContactExchangeStreamReader(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 an
-	 * invitation stream.
+	 * Creates an {@link OutputStream OutputStream} for writing to a contact
+	 * exchange stream.
 	 */
-	OutputStream createInvitationStreamWriter(OutputStream out,
+	OutputStream createContactExchangeStreamWriter(OutputStream out,
 			SecretKey headerKey);
 }

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

@@ -7,7 +7,7 @@ public interface TransportConstants {
 	/**
 	 * The current version of the transport protocol.
 	 */
-	int PROTOCOL_VERSION = 3;
+	int PROTOCOL_VERSION = 4;
 
 	/**
 	 * The length of the pseudo-random tag in bytes.
@@ -80,4 +80,32 @@ public interface TransportConstants {
 	 * The size of the reordering window.
 	 */
 	int REORDERING_WINDOW_SIZE = 32;
+
+	/**
+	 * Label for deriving Alice's initial tag key from the master secret.
+	 */
+	String ALICE_TAG_LABEL = "org.briarproject.bramble.transport/ALICE_TAG_KEY";
+
+	/**
+	 * Label for deriving Bob's initial tag key from the master secret.
+	 */
+	String BOB_TAG_LABEL = "org.briarproject.bramble.transport/BOB_TAG_KEY";
+
+	/**
+	 * Label for deriving Alice's initial header key from the master secret.
+	 */
+	String ALICE_HEADER_LABEL =
+			"org.briarproject.bramble.transport/ALICE_HEADER_KEY";
+
+	/**
+	 * Label for deriving Bob's initial header key from the master secret.
+	 */
+	String BOB_HEADER_LABEL =
+			"org.briarproject.bramble.transport/BOB_HEADER_KEY";
+
+	/**
+	 * Label for deriving the next period's key in key rotation.
+	 */
+	String ROTATE_LABEL = "org.briarproject.bramble.transport/ROTATE";
+
 }

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

@@ -8,6 +8,7 @@ import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.net.Socket;
 
 import javax.annotation.Nullable;
 
@@ -59,4 +60,24 @@ 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

@@ -8,6 +8,7 @@ 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;
@@ -27,6 +28,7 @@ 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;
@@ -139,4 +141,12 @@ 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/BrambleMockTestCase.java

@@ -3,8 +3,7 @@ package org.briarproject.bramble.test;
 import org.jmock.Mockery;
 import org.junit.After;
 
-public abstract class BrambleMockTestCase extends
-		BrambleTestCase {
+public abstract class BrambleMockTestCase extends BrambleTestCase {
 
 	protected final Mockery context = new Mockery();
 

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

@@ -8,12 +8,9 @@ public abstract class BrambleTestCase {
 
 	public BrambleTestCase() {
 		// Ensure exceptions thrown on worker threads cause tests to fail
-		UncaughtExceptionHandler fail = new UncaughtExceptionHandler() {
-			@Override
-			public void uncaughtException(Thread thread, Throwable throwable) {
-				throwable.printStackTrace();
-				fail();
-			}
+		UncaughtExceptionHandler fail = (thread, throwable) -> {
+			throwable.printStackTrace();
+			fail();
 		};
 		Thread.setDefaultUncaughtExceptionHandler(fail);
 	}

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

@@ -34,13 +34,6 @@ 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

@@ -1,28 +1,60 @@
-plugins {
-	id 'java'
-	id 'net.ltgt.apt' version '0.9'
-	id 'idea'
-}
-
-sourceCompatibility = 1.6
-targetCompatibility = 1.6
+apply plugin: 'java-library'
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
 
+apply plugin: 'net.ltgt.apt'
+apply plugin: 'idea'
 apply plugin: 'witness'
 
 dependencies {
-	compile project(':bramble-api')
-	compile 'com.madgag.spongycastle:core:1.56.0.0'
-	compile 'com.h2database:h2:1.4.192' // This is the last version that supports Java 1.6
-	compile 'org.bitlet:weupnp:0.1.4'
+	implementation project(path: ':bramble-api', configuration: 'default')
+	implementation 'com.madgag.spongycastle:core:1.58.0.0'
+	implementation 'com.h2database:h2:1.4.192' // The last version that supports Java 1.6
+	implementation 'org.bitlet:weupnp:0.1.4'
+	implementation 'net.i2p.crypto:eddsa:0.2.0'
 
-	testCompile project(path: ':bramble-api', configuration: 'testOutput')
+	apt 'com.google.dagger:dagger-compiler:2.0.2'
+
+	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
+	testImplementation 'org.hsqldb:hsqldb:2.3.5' // The last version that supports Java 1.6
+	testImplementation 'junit:junit:4.12'
+	testImplementation "org.jmock:jmock:2.8.2"
+	testImplementation "org.jmock:jmock-junit4:2.8.2"
+	testImplementation "org.jmock:jmock-legacy:2.8.2"
+	testImplementation "org.hamcrest:hamcrest-library:1.3"
+	testImplementation "org.hamcrest:hamcrest-core:1.3"
+	testImplementation "org.whispersystems:curve25519-java:0.4.1"
+
+	testApt 'com.google.dagger:dagger-compiler:2.0.2'
 }
 
 dependencyVerification {
 	verify = [
-			'com.madgag.spongycastle:core:5e791b0eaa9e0c4594231b44f616a52adddb7dccedeb0ad9ad74887e19499a23',
-			'com.h2database:h2:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
-			'org.bitlet:weupnp:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
+			'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+			'com.google.dagger:dagger-compiler:2.0.2:dagger-compiler-2.0.2.jar:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
+			'com.google.dagger:dagger-producers:2.0-beta:dagger-producers-2.0-beta.jar:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
+			'com.google.dagger:dagger:2.0.2:dagger-2.0.2.jar:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
+			'com.google.guava:guava:18.0:guava-18.0.jar:d664fbfc03d2e5ce9cab2a44fb01f1d0bf9dfebeccc1a473b1f9ea31f79f6f99',
+			'com.h2database:h2:1.4.192:h2-1.4.192.jar:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
+			'com.madgag.spongycastle:core:1.58.0.0:core-1.58.0.0.jar:199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728',
+			'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
+			'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
+			'net.i2p.crypto:eddsa:0.2.0:eddsa-0.2.0.jar:a7cb1b85c16e2f0730b9204106929a1d9aaae1df728adc7041a8b8b605692140',
+			'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
+			'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
+			'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
+			'org.bitlet:weupnp:0.1.4:weupnp-0.1.4.jar:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
+			'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
+			'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
+			'org.hsqldb:hsqldb:2.3.5:hsqldb-2.3.5.jar:6676a6977ac98997a80f827ddbd3fe8ca1e0853dad1492512135fd1a222ccfad',
+			'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
+			'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
+			'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
+			'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
+			'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
+			'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
+			'org.whispersystems:curve25519-java:0.4.1:curve25519-java-0.4.1.jar:7dd659d8822c06c3aea1a47f18fac9e5761e29cab8100030b877db445005f03e',
 	]
 }
 
@@ -37,3 +69,8 @@ task jarTest(type: Jar, dependsOn: testClasses) {
 artifacts {
 	testOutput jarTest
 }
+
+// If a Java 6 JRE is available, check we're not using any Java 7 or 8 APIs
+tasks.withType(JavaCompile) {
+	useJava6StandardLibrary(it)
+}

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

@@ -8,7 +8,6 @@ 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;
@@ -32,7 +31,6 @@ import dagger.Module;
 		DatabaseExecutorModule.class,
 		EventModule.class,
 		IdentityModule.class,
-		InvitationModule.class,
 		KeyAgreementModule.class,
 		LifecycleModule.class,
 		PluginModule.class,

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

@@ -24,7 +24,7 @@ public class PoliteExecutor implements Executor {
 
 	private final Object lock = new Object();
 	@GuardedBy("lock")
-	private final Queue<Runnable> queue = new LinkedList<Runnable>();
+	private final Queue<Runnable> queue = new LinkedList<>();
 	private final Executor delegate;
 	private final int maxConcurrentTasks;
 	private final Logger log;
@@ -48,20 +48,17 @@ public class PoliteExecutor implements Executor {
 	}
 
 	@Override
-	public void execute(final Runnable r) {
-		final long submitted = System.currentTimeMillis();
-		Runnable wrapped = new Runnable() {
-			@Override
-			public void run() {
-				if (log.isLoggable(LOG_LEVEL)) {
-					long queued = System.currentTimeMillis() - submitted;
-					log.log(LOG_LEVEL, "Queue time " + queued + " ms");
-				}
-				try {
-					r.run();
-				} finally {
-					scheduleNext();
-				}
+	public void execute(Runnable r) {
+		long submitted = System.currentTimeMillis();
+		Runnable wrapped = () -> {
+			if (log.isLoggable(LOG_LEVEL)) {
+				long queued = System.currentTimeMillis() - submitted;
+				log.log(LOG_LEVEL, "Queue time " + queued + " ms");
+			}
+			try {
+				r.run();
+			} finally {
+				scheduleNext();
 			}
 		};
 		synchronized (lock) {

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

@@ -28,19 +28,16 @@ public class TimeLoggingExecutor extends ThreadPoolExecutor {
 	}
 
 	@Override
-	public void execute(final Runnable r) {
+	public void execute(Runnable r) {
 		if (log.isLoggable(LOG_LEVEL)) {
-			final long submitted = System.currentTimeMillis();
-			super.execute(new Runnable() {
-				@Override
-				public void run() {
-					long started = System.currentTimeMillis();
-					long queued = started - submitted;
-					log.log(LOG_LEVEL, "Queue time " + queued + " ms");
-					r.run();
-					long executing = System.currentTimeMillis() - started;
-					log.log(LOG_LEVEL, "Execution time " + executing + " ms");
-				}
+			long submitted = System.currentTimeMillis();
+			super.execute(() -> {
+				long started = System.currentTimeMillis();
+				long queued = started - submitted;
+				log.log(LOG_LEVEL, "Queue time " + queued + " ms");
+				r.run();
+				long executing = System.currentTimeMillis() - started;
+				log.log(LOG_LEVEL, "Execution time " + executing + " ms");
 			});
 		} else {
 			super.execute(r);

bramble-core/src/main/java/org/briarproject/bramble/client/ClientHelperImpl.java

@@ -201,8 +201,7 @@ class ClientHelperImpl implements ClientHelper {
 	public Map<MessageId, BdfDictionary> getMessageMetadataAsDictionary(
 			Transaction txn, GroupId g) throws DbException, FormatException {
 		Map<MessageId, Metadata> raw = db.getMessageMetadata(txn, g);
-		Map<MessageId, BdfDictionary> parsed =
-				new HashMap<MessageId, BdfDictionary>(raw.size());
+		Map<MessageId, BdfDictionary> parsed = new HashMap<>(raw.size());
 		for (Entry<MessageId, Metadata> e : raw.entrySet())
 			parsed.put(e.getKey(), metadataParser.parse(e.getValue()));
 		return parsed;
@@ -229,8 +228,7 @@ class ClientHelperImpl implements ClientHelper {
 			FormatException {
 		Metadata metadata = metadataEncoder.encode(query);
 		Map<MessageId, Metadata> raw = db.getMessageMetadata(txn, g, metadata);
-		Map<MessageId, BdfDictionary> parsed =
-				new HashMap<MessageId, BdfDictionary>(raw.size());
+		Map<MessageId, BdfDictionary> parsed = new HashMap<>(raw.size());
 		for (Entry<MessageId, Metadata> e : raw.entrySet())
 			parsed.put(e.getKey(), metadataParser.parse(e.getValue()));
 		return parsed;

bramble-core/src/main/java/org/briarproject/bramble/client/ContactGroupFactoryImpl.java

@@ -32,23 +32,25 @@ class ContactGroupFactoryImpl implements ContactGroupFactory {
 	}
 
 	@Override
-	public Group createLocalGroup(ClientId clientId) {
-		return groupFactory.createGroup(clientId, LOCAL_GROUP_DESCRIPTOR);
+	public Group createLocalGroup(ClientId clientId, int clientVersion) {
+		return groupFactory.createGroup(clientId, clientVersion,
+				LOCAL_GROUP_DESCRIPTOR);
 	}
 
 	@Override
-	public Group createContactGroup(ClientId clientId, Contact contact) {
+	public Group createContactGroup(ClientId clientId, int clientVersion,
+			Contact contact) {
 		AuthorId local = contact.getLocalAuthorId();
 		AuthorId remote = contact.getAuthor().getId();
 		byte[] descriptor = createGroupDescriptor(local, remote);
-		return groupFactory.createGroup(clientId, descriptor);
+		return groupFactory.createGroup(clientId, clientVersion, descriptor);
 	}
 
 	@Override
-	public Group createContactGroup(ClientId clientId, AuthorId authorId1,
-			AuthorId authorId2) {
+	public Group createContactGroup(ClientId clientId, int clientVersion,
+			AuthorId authorId1, AuthorId authorId2) {
 		byte[] descriptor = createGroupDescriptor(authorId1, authorId2);
-		return groupFactory.createGroup(clientId, descriptor);
+		return groupFactory.createGroup(clientId, clientVersion, descriptor);
 	}
 
 	private byte[] createGroupDescriptor(AuthorId local, AuthorId remote) {

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
-	public ContactExchangeTaskImpl(DatabaseComponent db,
+	ContactExchangeTaskImpl(DatabaseComponent db,
 			AuthorFactory authorFactory, BdfReaderFactory bdfReaderFactory,
 			BdfWriterFactory bdfWriterFactory, Clock clock,
 			ConnectionManager connectionManager, ContactManager contactManager,
@@ -141,23 +141,27 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		}
 
 		// Derive the header keys for the transport streams
-		SecretKey aliceHeaderKey = crypto.deriveHeaderKey(masterSecret, true);
-		SecretKey bobHeaderKey = crypto.deriveHeaderKey(masterSecret, false);
+		SecretKey aliceHeaderKey = crypto.deriveKey(ALICE_KEY_LABEL,
+				masterSecret, new byte[] {PROTOCOL_VERSION});
+		SecretKey bobHeaderKey = crypto.deriveKey(BOB_KEY_LABEL, masterSecret,
+				new byte[] {PROTOCOL_VERSION});
 
 		// Create the readers
 		InputStream streamReader =
-				streamReaderFactory.createInvitationStreamReader(in,
+				streamReaderFactory.createContactExchangeStreamReader(in,
 						alice ? bobHeaderKey : aliceHeaderKey);
 		BdfReader r = bdfReaderFactory.createReader(streamReader);
 		// Create the writers
 		OutputStream streamWriter =
-				streamWriterFactory.createInvitationStreamWriter(out,
+				streamWriterFactory.createContactExchangeStreamWriter(out,
 						alice ? aliceHeaderKey : bobHeaderKey);
 		BdfWriter w = bdfWriterFactory.createWriter(streamWriter);
 
 		// Derive the nonces to be signed
-		byte[] aliceNonce = crypto.deriveSignatureNonce(masterSecret, true);
-		byte[] bobNonce = crypto.deriveSignatureNonce(masterSecret, false);
+		byte[] aliceNonce = crypto.mac(ALICE_NONCE_LABEL, masterSecret,
+				new byte[] {PROTOCOL_VERSION});
+		byte[] bobNonce = crypto.mac(BOB_NONCE_LABEL, masterSecret,
+				new byte[] {PROTOCOL_VERSION});
 
 		// Exchange pseudonyms, signed nonces, and timestamps
 		long localTimestamp = clock.currentTimeMillis();
@@ -184,12 +188,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 			// Close the outgoing stream and expect EOF on the incoming stream
 			w.close();
 			if (!r.eof()) LOG.warning("Unexpected data at end of connection");
-		} catch (GeneralSecurityException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-			listener.contactExchangeFailed();
-			tryToClose(conn, true);
-			return;
-		} catch (IOException e) {
+		} catch (GeneralSecurityException | IOException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			listener.contactExchangeFailed();
 			tryToClose(conn, true);
@@ -201,8 +200,8 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 
 		try {
 			// Add the contact
-			ContactId contactId = addContact(remoteAuthor, masterSecret,
-					timestamp, alice, remoteProperties);
+			ContactId contactId = addContact(remoteAuthor, timestamp,
+					remoteProperties);
 			// Reuse the connection as a transport connection
 			connectionManager.manageOutgoingConnection(contactId, transportId,
 					conn);
@@ -276,8 +275,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 
 	private Map<TransportId, TransportProperties> receiveTransportProperties(
 			BdfReader r) throws IOException {
-		Map<TransportId, TransportProperties> remote =
-				new HashMap<TransportId, TransportProperties>();
+		Map<TransportId, TransportProperties> remote = new HashMap<>();
 		r.readListStart();
 		while (!r.hasListEnd()) {
 			r.readListStart();
@@ -300,15 +298,15 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		return remote;
 	}
 
-	private ContactId addContact(Author remoteAuthor, SecretKey master,
-			long timestamp, boolean alice,
+	private ContactId addContact(Author remoteAuthor, long timestamp,
 			Map<TransportId, TransportProperties> remoteProperties)
 			throws DbException {
 		ContactId contactId;
 		Transaction txn = db.startTransaction(false);
 		try {
 			contactId = contactManager.addContact(txn, remoteAuthor,
-					localAuthor.getId(), master, timestamp, alice, true, true);
+					localAuthor.getId(), masterSecret, timestamp, alice,
+					true, true);
 			transportPropertyManager.addRemoteProperties(txn, contactId,
 					remoteProperties);
 			db.commitTransaction(txn);
@@ -318,8 +316,7 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		return contactId;
 	}
 
-	private void tryToClose(DuplexTransportConnection conn,
-			boolean exception) {
+	private void tryToClose(DuplexTransportConnection conn, boolean exception) {
 		try {
 			LOG.info("Closing connection");
 			conn.getReader().dispose(exception, true);

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

@@ -34,8 +34,8 @@ class ContactManagerImpl implements ContactManager {
 	ContactManagerImpl(DatabaseComponent db, KeyManager keyManager) {
 		this.db = db;
 		this.keyManager = keyManager;
-		addHooks = new CopyOnWriteArrayList<AddContactHook>();
-		removeHooks = new CopyOnWriteArrayList<RemoveContactHook>();
+		addHooks = new CopyOnWriteArrayList<>();
+		removeHooks = new CopyOnWriteArrayList<>();
 	}
 
 	@Override
@@ -125,7 +125,7 @@ class ContactManagerImpl implements ContactManager {
 		} finally {
 			db.endTransaction(txn);
 		}
-		List<Contact> active = new ArrayList<Contact>(contacts.size());
+		List<Contact> active = new ArrayList<>(contacts.size());
 		for (Contact c : contacts) if (c.isActive()) active.add(c);
 		return active;
 	}

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

@@ -1,17 +1,16 @@
 package org.briarproject.bramble.crypto;
 
+import net.i2p.crypto.eddsa.EdDSAPrivateKey;
+import net.i2p.crypto.eddsa.EdDSAPublicKey;
+import net.i2p.crypto.eddsa.KeyPairGenerator;
+
 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;
 import org.briarproject.bramble.api.system.SecureRandomProvider;
-import org.briarproject.bramble.api.transport.IncomingKeys;
-import org.briarproject.bramble.api.transport.OutgoingKeys;
-import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.util.ByteUtils;
 import org.briarproject.bramble.util.StringUtils;
 import org.spongycastle.crypto.AsymmetricCipherKeyPair;
@@ -27,7 +26,6 @@ import org.spongycastle.crypto.params.ECPrivateKeyParameters;
 import org.spongycastle.crypto.params.ECPublicKeyParameters;
 import org.spongycastle.crypto.params.KeyParameter;
 
-import java.nio.charset.Charset;
 import java.security.GeneralSecurityException;
 import java.security.NoSuchAlgorithmException;
 import java.security.Provider;
@@ -41,15 +39,8 @@ 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 {
 
@@ -58,52 +49,19 @@ class CryptoComponentImpl implements CryptoComponent {
 
 	private static final int AGREEMENT_KEY_PAIR_BITS = 256;
 	private static final int SIGNATURE_KEY_PAIR_BITS = 256;
+	private static final int ED_KEY_PAIR_BITS = 256;
 	private static final int STORAGE_IV_BYTES = 24; // 196 bits
 	private static final int PBKDF_SALT_BYTES = 32; // 256 bits
 	private static final int PBKDF_TARGET_MILLIS = 500;
 	private static final int PBKDF_SAMPLES = 30;
-	private static final int HASH_SIZE = 256 / 8;
-
-	private static byte[] ascii(String s) {
-		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");
-	// KDF labels for contact exchange signature nonce derivation
-	private static final byte[] A_SIG_NONCE = ascii("ALICE_SIGNATURE_NONCE");
-	private static final byte[] B_SIG_NONCE = ascii("BOB_SIGNATURE_NONCE");
-	// Hash label for BQP public key commitment derivation
-	private static final String COMMIT =
-			"org.briarproject.bramble.COMMIT";
-	// Hash label for shared secret derivation
-	private static final String SHARED_SECRET =
-			"org.briarproject.bramble.SHARED_SECRET";
-	// KDF label for BQP confirmation key derivation
-	private static final byte[] CONFIRMATION_KEY = ascii("CONFIRMATION_KEY");
-	// KDF label for master key derivation
-	private static final byte[] MASTER_KEY = ascii("MASTER_KEY");
-	// KDF labels for tag key derivation
-	private static final byte[] A_TAG = ascii("ALICE_TAG_KEY");
-	private static final byte[] B_TAG = ascii("BOB_TAG_KEY");
-	// KDF labels for header key derivation
-	private static final byte[] A_HEADER = ascii("ALICE_HEADER_KEY");
-	private static final byte[] B_HEADER = ascii("BOB_HEADER_KEY");
-	// KDF labels for MAC key derivation
-	private static final byte[] A_MAC = ascii("ALICE_MAC_KEY");
-	private static final byte[] B_MAC = ascii("BOB_MAC_KEY");
-	// KDF label for key rotation
-	private static final byte[] ROTATE = ascii("ROTATE");
 
 	private final SecureRandom secureRandom;
 	private final ECKeyPairGenerator agreementKeyPairGenerator;
 	private final ECKeyPairGenerator signatureKeyPairGenerator;
 	private final KeyParser agreementKeyParser, signatureKeyParser;
 	private final MessageEncrypter messageEncrypter;
+	private final KeyPairGenerator edKeyPairGenerator;
+	private final KeyParser edKeyParser;
 
 	@Inject
 	CryptoComponentImpl(SecureRandomProvider secureRandomProvider) {
@@ -137,6 +95,9 @@ class CryptoComponentImpl implements CryptoComponent {
 		signatureKeyParser = new Sec1KeyParser(PARAMETERS,
 				SIGNATURE_KEY_PAIR_BITS);
 		messageEncrypter = new MessageEncrypter(secureRandom);
+		edKeyPairGenerator = new KeyPairGenerator();
+		edKeyPairGenerator.initialize(ED_KEY_PAIR_BITS, secureRandom);
+		edKeyParser = new EdKeyParser();
 	}
 
 	// Based on https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html
@@ -171,14 +132,6 @@ 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;
@@ -203,6 +156,21 @@ class CryptoComponentImpl implements CryptoComponent {
 		return secret;
 	}
 
+	@Override
+	public KeyPair generateEdKeyPair() {
+		java.security.KeyPair keyPair = edKeyPairGenerator.generateKeyPair();
+		EdDSAPublicKey edPublicKey = (EdDSAPublicKey) keyPair.getPublic();
+		PublicKey publicKey = new EdPublicKey(edPublicKey.getAbyte());
+		EdDSAPrivateKey edPrivateKey = (EdDSAPrivateKey) keyPair.getPrivate();
+		PrivateKey privateKey = new EdPrivateKey(edPrivateKey.getSeed());
+		return new KeyPair(publicKey, privateKey);
+	}
+
+	@Override
+	public KeyParser getEdKeyParser() {
+		return edKeyParser;
+	}
+
 	@Override
 	public KeyPair generateAgreementKeyPair() {
 		AsymmetricCipherKeyPair keyPair =
@@ -251,211 +219,63 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public int generateBTInvitationCode() {
-		int codeBytes = (CODE_BITS + 7) / 8;
-		byte[] random = new byte[codeBytes];
-		secureRandom.nextBytes(random);
-		return ByteUtils.readUint(random, CODE_BITS);
+	public SecretKey deriveKey(String label, SecretKey k, byte[]... inputs) {
+		byte[] mac = mac(label, k, inputs);
+		if (mac.length != SecretKey.LENGTH) throw new IllegalStateException();
+		return new SecretKey(mac);
 	}
 
 	@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) {
-		return new SecretKey(macKdf(master, alice ? A_INVITE : B_INVITE));
-	}
-
-	@Override
-	public SecretKey deriveMacKey(SecretKey master, boolean alice) {
-		return new SecretKey(macKdf(master, alice ? A_MAC : B_MAC));
-	}
-
-	@Override
-	public byte[] deriveSignatureNonce(SecretKey master,
-			boolean alice) {
-		return macKdf(master, alice ? A_SIG_NONCE : B_SIG_NONCE);
-	}
-
-	@Override
-	public byte[] deriveKeyCommitment(byte[] publicKey) {
-		byte[] hash = hash(COMMIT, publicKey);
-		// The output is the first COMMIT_LENGTH bytes of the hash
-		byte[] commitment = new byte[COMMIT_LENGTH];
-		System.arraycopy(hash, 0, commitment, 0, COMMIT_LENGTH);
-		return commitment;
-	}
-
-	@Override
-	public SecretKey deriveSharedSecret(byte[] theirPublicKey,
-			KeyPair ourKeyPair, boolean alice) throws GeneralSecurityException {
+	public SecretKey deriveSharedSecret(String label, PublicKey theirPublicKey,
+			KeyPair ourKeyPair, byte[]... inputs)
+			throws GeneralSecurityException {
 		PrivateKey ourPriv = ourKeyPair.getPrivate();
-		PublicKey theirPub = agreementKeyParser.parsePublicKey(theirPublicKey);
-		byte[] raw = performRawKeyAgreement(ourPriv, theirPub);
-		byte[] alicePub, bobPub;
-		if (alice) {
-			alicePub = ourKeyPair.getPublic().getEncoded();
-			bobPub = theirPublicKey;
-		} else {
-			alicePub = theirPublicKey;
-			bobPub = ourKeyPair.getPublic().getEncoded();
-		}
-		return new SecretKey(hash(SHARED_SECRET, raw, alicePub, bobPub));
-	}
-
-	@Override
-	public byte[] deriveConfirmationRecord(SecretKey sharedSecret,
-			byte[] theirPayload, byte[] ourPayload, byte[] theirPublicKey,
-			KeyPair ourKeyPair, boolean alice, boolean aliceRecord) {
-		SecretKey ck = new SecretKey(macKdf(sharedSecret, CONFIRMATION_KEY));
-		byte[] alicePayload, alicePub, bobPayload, bobPub;
-		if (alice) {
-			alicePayload = ourPayload;
-			alicePub = ourKeyPair.getPublic().getEncoded();
-			bobPayload = theirPayload;
-			bobPub = theirPublicKey;
-		} else {
-			alicePayload = theirPayload;
-			alicePub = theirPublicKey;
-			bobPayload = ourPayload;
-			bobPub = ourKeyPair.getPublic().getEncoded();
-		}
-		if (aliceRecord)
-			return macKdf(ck, alicePayload, alicePub, bobPayload, bobPub);
-		else
-			return macKdf(ck, bobPayload, bobPub, alicePayload, alicePub);
-	}
-
-	@Override
-	public SecretKey deriveMasterSecret(SecretKey sharedSecret) {
-		return new SecretKey(macKdf(sharedSecret, MASTER_KEY));
-	}
-
-	@Override
-	public SecretKey deriveMasterSecret(byte[] theirPublicKey,
-			KeyPair ourKeyPair, boolean alice) throws GeneralSecurityException {
-		return deriveMasterSecret(deriveSharedSecret(
-				theirPublicKey, ourKeyPair, alice));
-	}
-
-	@Override
-	public TransportKeys deriveTransportKeys(TransportId t,
-			SecretKey master, long rotationPeriod, boolean alice) {
-		// Keys for the previous period are derived from the master secret
-		SecretKey inTagPrev = deriveTagKey(master, t, !alice);
-		SecretKey inHeaderPrev = deriveHeaderKey(master, t, !alice);
-		SecretKey outTagPrev = deriveTagKey(master, t, alice);
-		SecretKey outHeaderPrev = deriveHeaderKey(master, t, alice);
-		// Derive the keys for the current and next periods
-		SecretKey inTagCurr = rotateKey(inTagPrev, rotationPeriod);
-		SecretKey inHeaderCurr = rotateKey(inHeaderPrev, rotationPeriod);
-		SecretKey inTagNext = rotateKey(inTagCurr, rotationPeriod + 1);
-		SecretKey inHeaderNext = rotateKey(inHeaderCurr, rotationPeriod + 1);
-		SecretKey outTagCurr = rotateKey(outTagPrev, rotationPeriod);
-		SecretKey outHeaderCurr = rotateKey(outHeaderPrev, rotationPeriod);
-		// Initialise the reordering windows and stream counters
-		IncomingKeys inPrev = new IncomingKeys(inTagPrev, inHeaderPrev,
-				rotationPeriod - 1);
-		IncomingKeys inCurr = new IncomingKeys(inTagCurr, inHeaderCurr,
-				rotationPeriod);
-		IncomingKeys inNext = new IncomingKeys(inTagNext, inHeaderNext,
-				rotationPeriod + 1);
-		OutgoingKeys outCurr = new OutgoingKeys(outTagCurr, outHeaderCurr,
-				rotationPeriod);
-		// Collect and return the keys
-		return new TransportKeys(t, inPrev, inCurr, inNext, outCurr);
-	}
-
-	@Override
-	public TransportKeys rotateTransportKeys(TransportKeys k,
-			long rotationPeriod) {
-		if (k.getRotationPeriod() >= rotationPeriod) return k;
-		IncomingKeys inPrev = k.getPreviousIncomingKeys();
-		IncomingKeys inCurr = k.getCurrentIncomingKeys();
-		IncomingKeys inNext = k.getNextIncomingKeys();
-		OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
-		long startPeriod = outCurr.getRotationPeriod();
-		// Rotate the keys
-		for (long p = startPeriod + 1; p <= rotationPeriod; p++) {
-			inPrev = inCurr;
-			inCurr = inNext;
-			SecretKey inNextTag = rotateKey(inNext.getTagKey(), p + 1);
-			SecretKey inNextHeader = rotateKey(inNext.getHeaderKey(), p + 1);
-			inNext = new IncomingKeys(inNextTag, inNextHeader, p + 1);
-			SecretKey outCurrTag = rotateKey(outCurr.getTagKey(), p);
-			SecretKey outCurrHeader = rotateKey(outCurr.getHeaderKey(), p);
-			outCurr = new OutgoingKeys(outCurrTag, outCurrHeader, p);
-		}
-		// Collect and return the keys
-		return new TransportKeys(k.getTransportId(), inPrev, inCurr, inNext,
-				outCurr);
-	}
-
-	private SecretKey rotateKey(SecretKey k, long rotationPeriod) {
-		byte[] period = new byte[INT_64_BYTES];
-		ByteUtils.writeUint64(rotationPeriod, period, 0);
-		return new SecretKey(macKdf(k, ROTATE, period));
-	}
-
-	private SecretKey deriveTagKey(SecretKey master, TransportId t,
-			boolean alice) {
-		byte[] id = StringUtils.toUtf8(t.getString());
-		return new SecretKey(macKdf(master, alice ? A_TAG : B_TAG, id));
-	}
-
-	private SecretKey deriveHeaderKey(SecretKey master, TransportId t,
-			boolean alice) {
-		byte[] id = StringUtils.toUtf8(t.getString());
-		return new SecretKey(macKdf(master, alice ? A_HEADER : B_HEADER, id));
-	}
-
-	@Override
-	public void encodeTag(byte[] tag, SecretKey tagKey, int protocolVersion,
-			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
-		Digest prf = new Blake2sDigest(tagKey.getBytes());
-		// 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);
-		byte[] mac = new byte[macLength];
-		prf.doFinal(mac, 0);
-		// The output is the first TAG_LENGTH bytes of the MAC
-		System.arraycopy(mac, 0, tag, 0, TAG_LENGTH);
+		byte[][] hashInputs = new byte[inputs.length + 1][];
+		hashInputs[0] = performRawKeyAgreement(ourPriv, theirPublicKey);
+		System.arraycopy(inputs, 0, hashInputs, 1, inputs.length);
+		byte[] hash = hash(label, hashInputs);
+		if (hash.length != SecretKey.LENGTH) throw new IllegalStateException();
+		return new SecretKey(hash);
 	}
 
 	@Override
 	public byte[] sign(String label, byte[] toSign, byte[] privateKey)
 			throws GeneralSecurityException {
-		Signature signature = new SignatureImpl(secureRandom);
-		KeyParser keyParser = getSignatureKeyParser();
+		return sign(new SignatureImpl(secureRandom), signatureKeyParser, label,
+				toSign, privateKey);
+	}
+
+	@Override
+	public byte[] signEd(String label, byte[] toSign, byte[] privateKey)
+			throws GeneralSecurityException {
+		return sign(new EdSignature(), edKeyParser, label, toSign, privateKey);
+	}
+
+	private byte[] sign(Signature sig, KeyParser keyParser, String label,
+			byte[] toSign, byte[] privateKey) throws GeneralSecurityException {
 		PrivateKey key = keyParser.parsePrivateKey(privateKey);
-		signature.initSign(key);
-		updateSignature(signature, label, toSign);
-		return signature.sign();
+		sig.initSign(key);
+		updateSignature(sig, label, toSign);
+		return sig.sign();
 	}
 
 	@Override
 	public boolean verify(String label, byte[] signedData, byte[] publicKey,
 			byte[] signature) throws GeneralSecurityException {
-		Signature sig = new SignatureImpl(secureRandom);
-		KeyParser keyParser = getSignatureKeyParser();
+		return verify(new SignatureImpl(secureRandom), signatureKeyParser,
+				label, signedData, publicKey, signature);
+	}
+
+	@Override
+	public boolean verifyEd(String label, byte[] signedData, byte[] publicKey,
+			byte[] signature) throws GeneralSecurityException {
+		return verify(new EdSignature(), edKeyParser, label, signedData,
+				publicKey, signature);
+	}
+
+	private boolean verify(Signature sig, KeyParser keyParser, String label,
+			byte[] signedData, byte[] publicKey, byte[] signature)
+			throws GeneralSecurityException {
 		PublicKey key = keyParser.parsePublicKey(publicKey);
 		sig.initVerify(key);
 		updateSignature(sig, label, signedData);
@@ -463,7 +283,7 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	private void updateSignature(Signature signature, String label,
-			byte[] toSign) {
+			byte[] toSign) throws GeneralSecurityException {
 		byte[] labelBytes = StringUtils.toUtf8(label);
 		byte[] length = new byte[INT_32_BYTES];
 		ByteUtils.writeUint32(labelBytes.length, length, 0);
@@ -493,14 +313,13 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public int getHashLength() {
-		return HASH_SIZE;
-	}
-
-	@Override
-	public byte[] mac(SecretKey macKey, byte[]... inputs) {
+	public byte[] mac(String label, SecretKey macKey, byte[]... inputs) {
+		byte[] labelBytes = StringUtils.toUtf8(label);
 		Digest mac = new Blake2sDigest(macKey.getBytes());
 		byte[] length = new byte[INT_32_BYTES];
+		ByteUtils.writeUint32(labelBytes.length, length, 0);
+		mac.update(length, 0, length.length);
+		mac.update(labelBytes, 0, labelBytes.length);
 		for (byte[] input : inputs) {
 			ByteUtils.writeUint32(input.length, length, 0);
 			mac.update(length, 0, length.length);
@@ -592,30 +411,6 @@ class CryptoComponentImpl implements CryptoComponent {
 		return AsciiArmour.wrap(b, lineLength);
 	}
 
-	// Key derivation function based on a pseudo-random function - see
-	// NIST SP 800-108, section 5.1
-	private byte[] macKdf(SecretKey key, byte[]... inputs) {
-		// Initialise the PRF
-		Digest prf = new Blake2sDigest(key.getBytes());
-		// The output of the PRF must be long enough to use as a key
-		int macLength = prf.getDigestSize();
-		if (macLength < SecretKey.LENGTH) throw new IllegalStateException();
-		// Calculate the PRF over the concatenated length-prefixed inputs
-		byte[] length = new byte[INT_32_BYTES];
-		for (byte[] input : inputs) {
-			ByteUtils.writeUint32(input.length, length, 0);
-			prf.update(length, 0, length.length);
-			prf.update(input, 0, input.length);
-		}
-		byte[] mac = new byte[macLength];
-		prf.doFinal(mac, 0);
-		// The output is the first SecretKey.LENGTH bytes of the MAC
-		if (mac.length == SecretKey.LENGTH) return mac;
-		byte[] truncated = new byte[SecretKey.LENGTH];
-		System.arraycopy(mac, 0, truncated, 0, truncated.length);
-		return truncated;
-	}
-
 	// Password-based key derivation function - see PKCS#5 v2.1, section 5.2
 	private byte[] pbkdf2(String password, byte[] salt, int iterations) {
 		byte[] utf8 = StringUtils.toUtf8(password);
@@ -629,8 +424,8 @@ class CryptoComponentImpl implements CryptoComponent {
 
 	// Package access for testing
 	int chooseIterationCount(int targetMillis) {
-		List<Long> quickSamples = new ArrayList<Long>(PBKDF_SAMPLES);
-		List<Long> slowSamples = new ArrayList<Long>(PBKDF_SAMPLES);
+		List<Long> quickSamples = new ArrayList<>(PBKDF_SAMPLES);
+		List<Long> slowSamples = new ArrayList<>(PBKDF_SAMPLES);
 		long iterationNanos = 0, initNanos = 0;
 		while (iterationNanos <= 0 || initNanos <= 0) {
 			// Sample the running time with one iteration and two iterations

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

@@ -3,9 +3,11 @@ package org.briarproject.bramble.crypto;
 import org.briarproject.bramble.TimeLoggingExecutor;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.CryptoExecutor;
+import org.briarproject.bramble.api.crypto.KeyAgreementCrypto;
 import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
 import org.briarproject.bramble.api.crypto.StreamDecrypterFactory;
 import org.briarproject.bramble.api.crypto.StreamEncrypterFactory;
+import org.briarproject.bramble.api.crypto.TransportCrypto;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.system.SecureRandomProvider;
 
@@ -48,7 +50,7 @@ public class CryptoModule {
 
 	public CryptoModule() {
 		// Use an unbounded queue
-		BlockingQueue<Runnable> queue = new LinkedBlockingQueue<Runnable>();
+		BlockingQueue<Runnable> queue = new LinkedBlockingQueue<>();
 		// Discard tasks that are submitted during shutdown
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();
@@ -74,6 +76,12 @@ public class CryptoModule {
 		return new PasswordStrengthEstimatorImpl();
 	}
 
+	@Provides
+	TransportCrypto provideTransportCrypto(
+			TransportCryptoImpl transportCrypto) {
+		return transportCrypto;
+	}
+
 	@Provides
 	StreamDecrypterFactory provideStreamDecrypterFactory(
 			Provider<AuthenticatedCipher> cipherProvider) {
@@ -81,9 +89,17 @@ public class CryptoModule {
 	}
 
 	@Provides
-	StreamEncrypterFactory provideStreamEncrypterFactory(CryptoComponent crypto,
+	StreamEncrypterFactory provideStreamEncrypterFactory(
+			CryptoComponent crypto, TransportCrypto transportCrypto,
 			Provider<AuthenticatedCipher> cipherProvider) {
-		return new StreamEncrypterFactoryImpl(crypto, cipherProvider);
+		return new StreamEncrypterFactoryImpl(crypto, transportCrypto,
+				cipherProvider);
+	}
+
+	@Provides
+	KeyAgreementCrypto provideKeyAgreementCrypto(
+			KeyAgreementCryptoImpl keyAgreementCrypto) {
+		return keyAgreementCrypto;
 	}
 
 	@Provides

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

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.crypto.KeyParser;
+import org.briarproject.bramble.api.crypto.PrivateKey;
+import org.briarproject.bramble.api.crypto.PublicKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.security.GeneralSecurityException;
+
+@NotNullByDefault
+class EdKeyParser implements KeyParser {
+
+	@Override
+	public PublicKey parsePublicKey(byte[] encodedKey)
+			throws GeneralSecurityException {
+		if (encodedKey.length != 32) throw new GeneralSecurityException();
+		return new EdPublicKey(encodedKey);
+	}
+
+	@Override
+	public PrivateKey parsePrivateKey(byte[] encodedKey)
+			throws GeneralSecurityException {
+		if (encodedKey.length != 32) throw new GeneralSecurityException();
+		return new EdPrivateKey(encodedKey);
+	}
+}

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

@@ -0,0 +1,18 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.Bytes;
+import org.briarproject.bramble.api.crypto.PrivateKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+class EdPrivateKey extends Bytes implements PrivateKey {
+
+	EdPrivateKey(byte[] bytes) {
+		super(bytes);
+	}
+
+	@Override
+	public byte[] getEncoded() {
+		return getBytes();
+	}
+}

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

@@ -0,0 +1,18 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.Bytes;
+import org.briarproject.bramble.api.crypto.PublicKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+class EdPublicKey extends Bytes implements PublicKey {
+
+	EdPublicKey(byte[] bytes) {
+		super(bytes);
+	}
+
+	@Override
+	public byte[] getEncoded() {
+		return getBytes();
+	}
+}

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

@@ -0,0 +1,83 @@
+package org.briarproject.bramble.crypto;
+
+import net.i2p.crypto.eddsa.EdDSAPrivateKey;
+import net.i2p.crypto.eddsa.EdDSAPublicKey;
+import net.i2p.crypto.eddsa.EdDSASecurityProvider;
+import net.i2p.crypto.eddsa.spec.EdDSANamedCurveSpec;
+import net.i2p.crypto.eddsa.spec.EdDSANamedCurveTable;
+import net.i2p.crypto.eddsa.spec.EdDSAPrivateKeySpec;
+import net.i2p.crypto.eddsa.spec.EdDSAPublicKeySpec;
+
+import org.briarproject.bramble.api.crypto.PrivateKey;
+import org.briarproject.bramble.api.crypto.PublicKey;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.security.GeneralSecurityException;
+import java.security.NoSuchAlgorithmException;
+import java.security.Provider;
+
+import static net.i2p.crypto.eddsa.EdDSAEngine.SIGNATURE_ALGORITHM;
+
+@NotNullByDefault
+class EdSignature implements Signature {
+
+	private static final Provider PROVIDER = new EdDSASecurityProvider();
+
+	private static final EdDSANamedCurveSpec CURVE_SPEC =
+			EdDSANamedCurveTable.getByName("Ed25519");
+
+	private final java.security.Signature signature;
+
+	EdSignature() {
+		try {
+			signature = java.security.Signature
+					.getInstance(SIGNATURE_ALGORITHM, PROVIDER);
+		} catch (NoSuchAlgorithmException e) {
+			throw new AssertionError(e);
+		}
+	}
+
+	@Override
+	public void initSign(PrivateKey k) throws GeneralSecurityException {
+		if (!(k instanceof EdPrivateKey))
+			throw new IllegalArgumentException();
+		EdDSAPrivateKey privateKey = new EdDSAPrivateKey(
+				new EdDSAPrivateKeySpec(k.getEncoded(), CURVE_SPEC));
+		signature.initSign(privateKey);
+	}
+
+	@Override
+	public void initVerify(PublicKey k) throws GeneralSecurityException {
+		if (!(k instanceof EdPublicKey))
+			throw new IllegalArgumentException();
+		EdDSAPublicKey publicKey = new EdDSAPublicKey(
+				new EdDSAPublicKeySpec(k.getEncoded(), CURVE_SPEC));
+		signature.initVerify(publicKey);
+	}
+
+	@Override
+	public void update(byte b) throws GeneralSecurityException {
+		signature.update(b);
+	}
+
+	@Override
+	public void update(byte[] b) throws GeneralSecurityException {
+		signature.update(b);
+	}
+
+	@Override
+	public void update(byte[] b, int off, int len)
+			throws GeneralSecurityException {
+		signature.update(b, off, len);
+	}
+
+	@Override
+	public byte[] sign() throws GeneralSecurityException {
+		return signature.sign();
+	}
+
+	@Override
+	public boolean verify(byte[] sig) throws GeneralSecurityException {
+		return signature.verify(sig);
+	}
+}

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

@@ -0,0 +1,56 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.KeyAgreementCrypto;
+import org.briarproject.bramble.api.crypto.KeyPair;
+import org.briarproject.bramble.api.crypto.PublicKey;
+import org.briarproject.bramble.api.crypto.SecretKey;
+
+import javax.inject.Inject;
+
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.COMMIT_LENGTH;
+
+class KeyAgreementCryptoImpl implements KeyAgreementCrypto {
+
+	private final CryptoComponent crypto;
+
+	@Inject
+	KeyAgreementCryptoImpl(CryptoComponent crypto) {
+		this.crypto = crypto;
+	}
+
+	@Override
+	public byte[] deriveKeyCommitment(PublicKey publicKey) {
+		byte[] hash = crypto.hash(COMMIT_LABEL, publicKey.getEncoded());
+		// The output is the first COMMIT_LENGTH bytes of the hash
+		byte[] commitment = new byte[COMMIT_LENGTH];
+		System.arraycopy(hash, 0, commitment, 0, COMMIT_LENGTH);
+		return commitment;
+	}
+
+	@Override
+	public byte[] deriveConfirmationRecord(SecretKey sharedSecret,
+			byte[] theirPayload, byte[] ourPayload, PublicKey theirPublicKey,
+			KeyPair ourKeyPair, boolean alice, boolean aliceRecord) {
+		SecretKey ck = crypto.deriveKey(CONFIRMATION_KEY_LABEL, sharedSecret);
+		byte[] alicePayload, alicePub, bobPayload, bobPub;
+		if (alice) {
+			alicePayload = ourPayload;
+			alicePub = ourKeyPair.getPublic().getEncoded();
+			bobPayload = theirPayload;
+			bobPub = theirPublicKey.getEncoded();
+		} else {
+			alicePayload = theirPayload;
+			alicePub = theirPublicKey.getEncoded();
+			bobPayload = ourPayload;
+			bobPub = ourKeyPair.getPublic().getEncoded();
+		}
+		if (aliceRecord) {
+			return crypto.mac(CONFIRMATION_MAC_LABEL, ck, alicePayload,
+					alicePub, bobPayload, bobPub);
+		} else {
+			return crypto.mac(CONFIRMATION_MAC_LABEL, ck, bobPayload, bobPub,
+					alicePayload, alicePub);
+		}
+	}
+}

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

@@ -16,7 +16,7 @@ class PasswordStrengthEstimatorImpl implements PasswordStrengthEstimator {
 
 	@Override
 	public float estimateStrength(String password) {
-		HashSet<Character> unique = new HashSet<Character>();
+		HashSet<Character> unique = new HashSet<>();
 		int length = password.length();
 		for (int i = 0; i < length; i++) unique.add(password.charAt(i));
 		return Math.min(1, (float) unique.size() / STRONG_UNIQUE_CHARS);

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

@@ -22,25 +22,25 @@ interface Signature {
 	/**
 	 * @see {@link java.security.Signature#update(byte)}
 	 */
-	void update(byte b);
+	void update(byte b) throws GeneralSecurityException;
 
 	/**
 	 * @see {@link java.security.Signature#update(byte[])}
 	 */
-	void update(byte[] b);
+	void update(byte[] b) throws GeneralSecurityException;
 
 	/**
 	 * @see {@link java.security.Signature#update(byte[], int, int)}
 	 */
-	void update(byte[] b, int off, int len);
+	void update(byte[] b, int off, int len) throws GeneralSecurityException;
 
 	/**
 	 * @see {@link java.security.Signature#sign()}
 	 */
-	byte[] sign();
+	byte[] sign() throws GeneralSecurityException;
 
 	/**
 	 * @see {@link java.security.Signature#verify(byte[])}
 	 */
-	boolean verify(byte[] signature);
+	boolean verify(byte[] signature) throws GeneralSecurityException;
 }

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

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

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

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.StreamEncrypter;
 import org.briarproject.bramble.api.crypto.StreamEncrypterFactory;
+import org.briarproject.bramble.api.crypto.TransportCrypto;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.transport.StreamContext;
 
@@ -22,12 +23,15 @@ import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENG
 class StreamEncrypterFactoryImpl implements StreamEncrypterFactory {
 
 	private final CryptoComponent crypto;
+	private final TransportCrypto transportCrypto;
 	private final Provider<AuthenticatedCipher> cipherProvider;
 
 	@Inject
 	StreamEncrypterFactoryImpl(CryptoComponent crypto,
+			TransportCrypto transportCrypto,
 			Provider<AuthenticatedCipher> cipherProvider) {
 		this.crypto = crypto;
+		this.transportCrypto = transportCrypto;
 		this.cipherProvider = cipherProvider;
 	}
 
@@ -37,7 +41,8 @@ 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);
+		transportCrypto.encodeTag(tag, ctx.getTagKey(), PROTOCOL_VERSION,
+				streamNumber);
 		byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
 		crypto.getSecureRandom().nextBytes(streamHeaderNonce);
 		SecretKey frameKey = crypto.generateSecretKey();
@@ -46,8 +51,8 @@ class StreamEncrypterFactoryImpl implements StreamEncrypterFactory {
 	}
 
 	@Override
-	public StreamEncrypter createInvitationStreamEncrypter(OutputStream out,
-			SecretKey headerKey) {
+	public StreamEncrypter createContactExchangeStreamDecrypter(
+			OutputStream out, SecretKey headerKey) {
 		AuthenticatedCipher cipher = cipherProvider.get();
 		byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
 		crypto.getSecureRandom().nextBytes(streamHeaderNonce);

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

@@ -0,0 +1,135 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.crypto.TransportCrypto;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.transport.IncomingKeys;
+import org.briarproject.bramble.api.transport.OutgoingKeys;
+import org.briarproject.bramble.api.transport.TransportKeys;
+import org.briarproject.bramble.util.ByteUtils;
+import org.briarproject.bramble.util.StringUtils;
+import org.spongycastle.crypto.Digest;
+
+import javax.inject.Inject;
+
+import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_HEADER_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.ALICE_TAG_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.BOB_HEADER_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.BOB_TAG_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.ROTATE_LABEL;
+import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
+import static org.briarproject.bramble.util.ByteUtils.INT_16_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 TransportCryptoImpl implements TransportCrypto {
+
+	private final CryptoComponent crypto;
+
+	@Inject
+	TransportCryptoImpl(CryptoComponent crypto) {
+		this.crypto = crypto;
+	}
+
+	@Override
+	public TransportKeys deriveTransportKeys(TransportId t,
+			SecretKey master, long rotationPeriod, boolean alice) {
+		// Keys for the previous period are derived from the master secret
+		SecretKey inTagPrev = deriveTagKey(master, t, !alice);
+		SecretKey inHeaderPrev = deriveHeaderKey(master, t, !alice);
+		SecretKey outTagPrev = deriveTagKey(master, t, alice);
+		SecretKey outHeaderPrev = deriveHeaderKey(master, t, alice);
+		// Derive the keys for the current and next periods
+		SecretKey inTagCurr = rotateKey(inTagPrev, rotationPeriod);
+		SecretKey inHeaderCurr = rotateKey(inHeaderPrev, rotationPeriod);
+		SecretKey inTagNext = rotateKey(inTagCurr, rotationPeriod + 1);
+		SecretKey inHeaderNext = rotateKey(inHeaderCurr, rotationPeriod + 1);
+		SecretKey outTagCurr = rotateKey(outTagPrev, rotationPeriod);
+		SecretKey outHeaderCurr = rotateKey(outHeaderPrev, rotationPeriod);
+		// Initialise the reordering windows and stream counters
+		IncomingKeys inPrev = new IncomingKeys(inTagPrev, inHeaderPrev,
+				rotationPeriod - 1);
+		IncomingKeys inCurr = new IncomingKeys(inTagCurr, inHeaderCurr,
+				rotationPeriod);
+		IncomingKeys inNext = new IncomingKeys(inTagNext, inHeaderNext,
+				rotationPeriod + 1);
+		OutgoingKeys outCurr = new OutgoingKeys(outTagCurr, outHeaderCurr,
+				rotationPeriod);
+		// Collect and return the keys
+		return new TransportKeys(t, inPrev, inCurr, inNext, outCurr);
+	}
+
+	@Override
+	public TransportKeys rotateTransportKeys(TransportKeys k,
+			long rotationPeriod) {
+		if (k.getRotationPeriod() >= rotationPeriod) return k;
+		IncomingKeys inPrev = k.getPreviousIncomingKeys();
+		IncomingKeys inCurr = k.getCurrentIncomingKeys();
+		IncomingKeys inNext = k.getNextIncomingKeys();
+		OutgoingKeys outCurr = k.getCurrentOutgoingKeys();
+		long startPeriod = outCurr.getRotationPeriod();
+		// Rotate the keys
+		for (long p = startPeriod + 1; p <= rotationPeriod; p++) {
+			inPrev = inCurr;
+			inCurr = inNext;
+			SecretKey inNextTag = rotateKey(inNext.getTagKey(), p + 1);
+			SecretKey inNextHeader = rotateKey(inNext.getHeaderKey(), p + 1);
+			inNext = new IncomingKeys(inNextTag, inNextHeader, p + 1);
+			SecretKey outCurrTag = rotateKey(outCurr.getTagKey(), p);
+			SecretKey outCurrHeader = rotateKey(outCurr.getHeaderKey(), p);
+			outCurr = new OutgoingKeys(outCurrTag, outCurrHeader, p);
+		}
+		// Collect and return the keys
+		return new TransportKeys(k.getTransportId(), inPrev, inCurr, inNext,
+				outCurr);
+	}
+
+	private SecretKey rotateKey(SecretKey k, long rotationPeriod) {
+		byte[] period = new byte[INT_64_BYTES];
+		ByteUtils.writeUint64(rotationPeriod, period, 0);
+		return crypto.deriveKey(ROTATE_LABEL, k, period);
+	}
+
+	private SecretKey deriveTagKey(SecretKey master, TransportId t,
+			boolean alice) {
+		String label = alice ? ALICE_TAG_LABEL : BOB_TAG_LABEL;
+		byte[] id = StringUtils.toUtf8(t.getString());
+		return crypto.deriveKey(label, master, id);
+	}
+
+	private SecretKey deriveHeaderKey(SecretKey master, TransportId t,
+			boolean alice) {
+		String label = alice ? ALICE_HEADER_LABEL : BOB_HEADER_LABEL;
+		byte[] id = StringUtils.toUtf8(t.getString());
+		return crypto.deriveKey(label, master, id);
+	}
+
+	@Override
+	public void encodeTag(byte[] tag, SecretKey tagKey, int protocolVersion,
+			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
+		Digest prf = new Blake2sDigest(tagKey.getBytes());
+		// 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);
+		byte[] mac = new byte[macLength];
+		prf.doFinal(mac, 0);
+		// The output is the first TAG_LENGTH bytes of the MAC
+		System.arraycopy(mac, 0, tag, 0, TAG_LENGTH);
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseComponentImpl.java

@@ -90,8 +90,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	private final ReentrantReadWriteLock lock =
 			new ReentrantReadWriteLock(true);
 
-	private volatile int shutdownHandle = -1;
-
 	@Inject
 	DatabaseComponentImpl(Database<T> db, Class<T> txnClass, EventBus eventBus,
 			ShutdownManager shutdown) {
@@ -103,26 +101,20 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 
 	@Override
 	public boolean open() throws DbException {
-		Runnable shutdownHook = new Runnable() {
-			@Override
-			public void run() {
-				try {
-					close();
-				} catch (DbException e) {
-					if (LOG.isLoggable(WARNING))
-						LOG.log(WARNING, e.toString(), e);
-				}
-			}
-		};
 		boolean reopened = db.open();
-		shutdownHandle = shutdown.addShutdownHook(shutdownHook);
+		shutdown.addShutdownHook(() -> {
+			try {
+				close();
+			} catch (DbException e) {
+				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			}
+		});
 		return reopened;
 	}
 
 	@Override
 	public void close() throws DbException {
 		if (closed.getAndSet(true)) return;
-		shutdown.removeShutdownHook(shutdownHandle);
 		db.close();
 	}
 
@@ -141,11 +133,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		}
 		try {
 			return new Transaction(db.startTransaction(), readOnly);
-		} catch (DbException e) {
-			if (readOnly) lock.readLock().unlock();
-			else lock.writeLock().unlock();
-			throw e;
-		} catch (RuntimeException e) {
+		} catch (DbException | RuntimeException e) {
 			if (readOnly) lock.readLock().unlock();
 			else lock.writeLock().unlock();
 			throw e;
@@ -331,7 +319,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
 		Collection<MessageId> ids = db.getMessagesToSend(txn, c, maxLength);
-		List<byte[]> messages = new ArrayList<byte[]>(ids.size());
+		List<byte[]> messages = new ArrayList<>(ids.size());
 		for (MessageId m : ids) {
 			messages.add(db.getRawMessage(txn, m));
 			db.updateExpiryTime(txn, c, m, maxLatency);
@@ -381,7 +369,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			throw new NoSuchContactException();
 		Collection<MessageId> ids = db.getRequestedMessagesToSend(txn, c,
 				maxLength);
-		List<byte[]> messages = new ArrayList<byte[]>(ids.size());
+		List<byte[]> messages = new ArrayList<>(ids.size());
 		for (MessageId m : ids) {
 			messages.add(db.getRawMessage(txn, m));
 			db.updateExpiryTime(txn, c, m, maxLatency);
@@ -661,7 +649,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
-		Collection<MessageId> acked = new ArrayList<MessageId>();
+		Collection<MessageId> acked = new ArrayList<>();
 		for (MessageId m : a.getMessageIds()) {
 			if (db.containsVisibleMessage(txn, c, m)) {
 				db.raiseSeenFlag(txn, c, m);
@@ -770,6 +758,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		transaction.attach(new LocalAuthorRemovedEvent(a));
 	}
 
+	@Override
+	public void removeMessage(Transaction transaction, MessageId m)
+			throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsMessage(txn, m))
+			throw new NoSuchMessageException();
+		db.removeMessage(txn, m);
+	}
+
 	@Override
 	public void removeTransport(Transaction transaction, TransportId t)
 			throws DbException {
@@ -886,8 +884,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			Map<ContactId, TransportKeys> keys) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
-		Map<ContactId, TransportKeys> filtered =
-				new HashMap<ContactId, TransportKeys>();
+		Map<ContactId, TransportKeys> filtered = new HashMap<>();
 		for (Entry<ContactId, TransportKeys> e : keys.entrySet()) {
 			ContactId c = e.getKey();
 			TransportKeys k = e.getValue();

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseExecutorModule.java

@@ -32,7 +32,7 @@ public class DatabaseExecutorModule {
 
 	public DatabaseExecutorModule() {
 		// Use an unbounded queue
-		BlockingQueue<Runnable> queue = new LinkedBlockingQueue<Runnable>();
+		BlockingQueue<Runnable> queue = new LinkedBlockingQueue<>();
 		// Discard tasks that are submitted during shutdown
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();

bramble-core/src/main/java/org/briarproject/bramble/db/DatabaseModule.java

@@ -26,7 +26,7 @@ public class DatabaseModule {
 	@Singleton
 	DatabaseComponent provideDatabaseComponent(Database<Connection> db,
 			EventBus eventBus, ShutdownManager shutdown) {
-		return new DatabaseComponentImpl<Connection>(db, Connection.class,
-				eventBus, shutdown);
+		return new DatabaseComponentImpl<>(db, Connection.class, eventBus,
+				shutdown);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/db/H2Database.java

@@ -22,21 +22,23 @@ import javax.inject.Inject;
 class H2Database extends JdbcDatabase {
 
 	private static final String HASH_TYPE = "BINARY(32)";
+	private static final String SECRET_TYPE = "BINARY(32)";
 	private static final String BINARY_TYPE = "BINARY";
 	private static final String COUNTER_TYPE = "INT NOT NULL AUTO_INCREMENT";
-	private static final String SECRET_TYPE = "BINARY(32)";
+	private static final String STRING_TYPE = "VARCHAR";
 
 	private final DatabaseConfig config;
 	private final String url;
 
 	@Inject
 	H2Database(DatabaseConfig config, Clock clock) {
-		super(HASH_TYPE, BINARY_TYPE, COUNTER_TYPE, SECRET_TYPE, clock);
+		super(HASH_TYPE, SECRET_TYPE, BINARY_TYPE, COUNTER_TYPE, STRING_TYPE,
+				clock);
 		this.config = config;
 		File dir = config.getDatabaseDirectory();
 		String path = new File(dir, "db").getAbsolutePath();
 		url = "jdbc:h2:split:" + path + ";CIPHER=AES;MULTI_THREADED=1"
-				+ ";WRITE_DELAY=0;DB_CLOSE_ON_EXIT=false";
+				+ ";WRITE_DELAY=0";
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/db/HyperSqlDatabase.java

@@ -0,0 +1,99 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.db.DatabaseConfig;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.util.StringUtils;
+
+import java.io.File;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.sql.Statement;
+
+import javax.inject.Inject;
+
+/**
+ * Contains all the HSQLDB-specific code for the database.
+ */
+@NotNullByDefault
+class HyperSqlDatabase extends JdbcDatabase {
+
+	private static final String HASH_TYPE = "BINARY(32)";
+	private static final String SECRET_TYPE = "BINARY(32)";
+	private static final String BINARY_TYPE = "BINARY";
+	private static final String COUNTER_TYPE =
+			"INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY(START WITH 1)";
+	private static final String STRING_TYPE = "VARCHAR";
+
+	private final DatabaseConfig config;
+	private final String url;
+
+	@Inject
+	HyperSqlDatabase(DatabaseConfig config, Clock clock) {
+		super(HASH_TYPE, SECRET_TYPE, BINARY_TYPE, COUNTER_TYPE, STRING_TYPE,
+				clock);
+		this.config = config;
+		File dir = config.getDatabaseDirectory();
+		String path = new File(dir, "db").getAbsolutePath();
+		url = "jdbc:hsqldb:file:" + path
+				+ ";sql.enforce_size=false;allow_empty_batch=true"
+				+ ";encrypt_lobs=true;crypt_type=AES";
+	}
+
+	@Override
+	public boolean open() throws DbException {
+		boolean reopen = config.databaseExists();
+		if (!reopen) config.getDatabaseDirectory().mkdirs();
+		super.open("org.hsqldb.jdbc.JDBCDriver", reopen);
+		return reopen;
+	}
+
+	@Override
+	public void close() throws DbException {
+		try {
+			super.closeAllConnections();
+			Connection c = createConnection();
+			Statement s = c.createStatement();
+			s.executeQuery("SHUTDOWN");
+			s.close();
+			c.close();
+		} catch (SQLException e) {
+			throw new DbException(e);
+		}
+	}
+
+	@Override
+	public long getFreeSpace() throws DbException {
+		File dir = config.getDatabaseDirectory();
+		long maxSize = config.getMaxSize();
+		long free = dir.getFreeSpace();
+		long used = getDiskSpace(dir);
+		long quota = maxSize - used;
+		return Math.min(free, quota);
+	}
+
+	private long getDiskSpace(File f) {
+		if (f.isDirectory()) {
+			long total = 0;
+			File[] children = f.listFiles();
+			if (children != null)
+				for (File child : children) total += getDiskSpace(child);
+			return total;
+		} else if (f.isFile()) {
+			return f.length();
+		} else {
+			return 0;
+		}
+	}
+
+	@Override
+	protected Connection createConnection() throws SQLException {
+		SecretKey key = config.getEncryptionKey();
+		if (key == null) throw new IllegalStateException();
+		String hex = StringUtils.toHexString(key.getBytes());
+		return DriverManager.getConnection(url + ";crypt_key=" + hex);
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/db/JdbcDatabase.java

@@ -68,32 +68,32 @@ import static org.briarproject.bramble.db.ExponentialBackoff.calculateExpiry;
 @NotNullByDefault
 abstract class JdbcDatabase implements Database<Connection> {
 
-	private static final int SCHEMA_VERSION = 30;
-	private static final int MIN_SCHEMA_VERSION = 30;
+	private static final int SCHEMA_VERSION = 31;
+	private static final int MIN_SCHEMA_VERSION = 31;
 
 	private static final String CREATE_SETTINGS =
 			"CREATE TABLE settings"
-					+ " (namespace VARCHAR NOT NULL,"
-					+ " key VARCHAR NOT NULL,"
-					+ " value VARCHAR NOT NULL,"
-					+ " PRIMARY KEY (namespace, key))";
+					+ " (namespace _STRING NOT NULL,"
+					+ " settingKey _STRING NOT NULL,"
+					+ " value _STRING NOT NULL,"
+					+ " PRIMARY KEY (namespace, settingKey))";
 
 	private static final String CREATE_LOCAL_AUTHORS =
 			"CREATE TABLE localAuthors"
-					+ " (authorId HASH NOT NULL,"
-					+ " name VARCHAR NOT NULL,"
-					+ " publicKey BINARY NOT NULL,"
-					+ " privateKey BINARY NOT NULL,"
+					+ " (authorId _HASH NOT NULL,"
+					+ " name _STRING NOT NULL,"
+					+ " publicKey _BINARY NOT NULL,"
+					+ " privateKey _BINARY NOT NULL,"
 					+ " created BIGINT NOT NULL,"
 					+ " PRIMARY KEY (authorId))";
 
 	private static final String CREATE_CONTACTS =
 			"CREATE TABLE contacts"
-					+ " (contactId COUNTER,"
-					+ " authorId HASH NOT NULL,"
-					+ " name VARCHAR NOT NULL,"
-					+ " publicKey BINARY NOT NULL,"
-					+ " localAuthorId HASH NOT NULL,"
+					+ " (contactId _COUNTER,"
+					+ " authorId _HASH NOT NULL,"
+					+ " name _STRING NOT NULL,"
+					+ " publicKey _BINARY NOT NULL,"
+					+ " localAuthorId _HASH NOT NULL,"
 					+ " verified BOOLEAN NOT NULL,"
 					+ " active BOOLEAN NOT NULL,"
 					+ " PRIMARY KEY (contactId),"
@@ -103,17 +103,17 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	private static final String CREATE_GROUPS =
 			"CREATE TABLE groups"
-					+ " (groupId HASH NOT NULL,"
-					+ " clientId VARCHAR NOT NULL,"
-					+ " descriptor BINARY NOT NULL,"
+					+ " (groupId _HASH NOT NULL,"
+					+ " clientId _STRING NOT NULL,"
+					+ " descriptor _BINARY NOT NULL,"
 					+ " PRIMARY KEY (groupId))";
 
 	private static final String CREATE_GROUP_METADATA =
 			"CREATE TABLE groupMetadata"
-					+ " (groupId HASH NOT NULL,"
-					+ " key VARCHAR NOT NULL,"
-					+ " value BINARY NOT NULL,"
-					+ " PRIMARY KEY (groupId, key),"
+					+ " (groupId _HASH NOT NULL,"
+					+ " metaKey _STRING NOT NULL,"
+					+ " value _BINARY NOT NULL,"
+					+ " PRIMARY KEY (groupId, metaKey),"
 					+ " FOREIGN KEY (groupId)"
 					+ " REFERENCES groups (groupId)"
 					+ " ON DELETE CASCADE)";
@@ -121,7 +121,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private static final String CREATE_GROUP_VISIBILITIES =
 			"CREATE TABLE groupVisibilities"
 					+ " (contactId INT NOT NULL,"
-					+ " groupId HASH NOT NULL,"
+					+ " groupId _HASH NOT NULL,"
 					+ " shared BOOLEAN NOT NULL,"
 					+ " PRIMARY KEY (contactId, groupId),"
 					+ " FOREIGN KEY (contactId)"
@@ -133,8 +133,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	private static final String CREATE_MESSAGES =
 			"CREATE TABLE messages"
-					+ " (messageId HASH NOT NULL,"
-					+ " groupId HASH NOT NULL,"
+					+ " (messageId _HASH NOT NULL,"
+					+ " groupId _HASH NOT NULL,"
 					+ " timestamp BIGINT NOT NULL,"
 					+ " state INT NOT NULL,"
 					+ " shared BOOLEAN NOT NULL,"
@@ -147,19 +147,19 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	private static final String CREATE_MESSAGE_METADATA =
 			"CREATE TABLE messageMetadata"
-					+ " (messageId HASH NOT NULL,"
-					+ " key VARCHAR NOT NULL,"
-					+ " value BINARY NOT NULL,"
-					+ " PRIMARY KEY (messageId, key),"
+					+ " (messageId _HASH NOT NULL,"
+					+ " metaKey _STRING NOT NULL,"
+					+ " value _BINARY NOT NULL,"
+					+ " PRIMARY KEY (messageId, metaKey),"
 					+ " FOREIGN KEY (messageId)"
 					+ " REFERENCES messages (messageId)"
 					+ " ON DELETE CASCADE)";
 
 	private static final String CREATE_MESSAGE_DEPENDENCIES =
 			"CREATE TABLE messageDependencies"
-					+ " (groupId HASH NOT NULL,"
-					+ " messageId HASH NOT NULL,"
-					+ " dependencyId HASH NOT NULL," // Not a foreign key
+					+ " (groupId _HASH NOT NULL,"
+					+ " messageId _HASH NOT NULL,"
+					+ " dependencyId _HASH NOT NULL," // Not a foreign key
 					+ " FOREIGN KEY (groupId)"
 					+ " REFERENCES groups (groupId)"
 					+ " ON DELETE CASCADE,"
@@ -169,7 +169,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	private static final String CREATE_OFFERS =
 			"CREATE TABLE offers"
-					+ " (messageId HASH NOT NULL," // Not a foreign key
+					+ " (messageId _HASH NOT NULL," // Not a foreign key
 					+ " contactId INT NOT NULL,"
 					+ " PRIMARY KEY (messageId, contactId),"
 					+ " FOREIGN KEY (contactId)"
@@ -178,7 +178,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	private static final String CREATE_STATUSES =
 			"CREATE TABLE statuses"
-					+ " (messageId HASH NOT NULL,"
+					+ " (messageId _HASH NOT NULL,"
 					+ " contactId INT NOT NULL,"
 					+ " ack BOOLEAN NOT NULL,"
 					+ " seen BOOLEAN NOT NULL,"
@@ -195,20 +195,20 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	private static final String CREATE_TRANSPORTS =
 			"CREATE TABLE transports"
-					+ " (transportId VARCHAR NOT NULL,"
+					+ " (transportId _STRING NOT NULL,"
 					+ " maxLatency INT NOT NULL,"
 					+ " PRIMARY KEY (transportId))";
 
 	private static final String CREATE_INCOMING_KEYS =
 			"CREATE TABLE incomingKeys"
 					+ " (contactId INT NOT NULL,"
-					+ " transportId VARCHAR NOT NULL,"
-					+ " period BIGINT NOT NULL,"
-					+ " tagKey SECRET NOT NULL,"
-					+ " headerKey SECRET NOT NULL,"
+					+ " transportId _STRING NOT NULL,"
+					+ " rotationPeriod BIGINT NOT NULL,"
+					+ " tagKey _SECRET NOT NULL,"
+					+ " headerKey _SECRET NOT NULL,"
 					+ " base BIGINT NOT NULL,"
-					+ " bitmap BINARY NOT NULL,"
-					+ " PRIMARY KEY (contactId, transportId, period),"
+					+ " bitmap _BINARY NOT NULL,"
+					+ " PRIMARY KEY (contactId, transportId, rotationPeriod),"
 					+ " FOREIGN KEY (contactId)"
 					+ " REFERENCES contacts (contactId)"
 					+ " ON DELETE CASCADE,"
@@ -219,10 +219,10 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private static final String CREATE_OUTGOING_KEYS =
 			"CREATE TABLE outgoingKeys"
 					+ " (contactId INT NOT NULL,"
-					+ " transportId VARCHAR NOT NULL,"
-					+ " period BIGINT NOT NULL,"
-					+ " tagKey SECRET NOT NULL,"
-					+ " headerKey SECRET NOT NULL,"
+					+ " transportId _STRING NOT NULL,"
+					+ " rotationPeriod BIGINT NOT NULL,"
+					+ " tagKey _SECRET NOT NULL,"
+					+ " headerKey _SECRET NOT NULL,"
 					+ " stream BIGINT NOT NULL,"
 					+ " PRIMARY KEY (contactId, transportId),"
 					+ " FOREIGN KEY (contactId)"
@@ -232,15 +232,40 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " REFERENCES transports (transportId)"
 					+ " ON DELETE CASCADE)";
 
+	private static final String INDEX_CONTACTS_BY_AUTHOR_ID =
+			"CREATE INDEX IF NOT EXISTS contactsByAuthorId"
+					+ " ON contacts (authorId)";
+
+	private static final String INDEX_MESSAGES_BY_GROUP_ID =
+			"CREATE INDEX IF NOT EXISTS messagesByGroupId"
+					+ " ON messages (groupId)";
+
+	private static final String INDEX_OFFERS_BY_CONTACT_ID =
+			"CREATE INDEX IF NOT EXISTS offersByContactId"
+					+ " ON offers (contactId)";
+
+	private static final String INDEX_GROUPS_BY_CLIENT_ID =
+			"CREATE INDEX IF NOT EXISTS groupsByClientId"
+					+ " ON groups (clientId)";
+
+	private static final String INDEX_MESSAGE_METADATA_BY_MESSAGE_ID =
+			"CREATE INDEX IF NOT EXISTS messageMetadataByMessageId"
+					+ " ON messageMetadata (messageId)";
+
+	private static final String INDEX_GROUP_METADATA_BY_GROUP_ID =
+			"CREATE INDEX IF NOT EXISTS groupMetadataByGroupId"
+					+ " ON groupMetadata (groupId)";
+
 	private static final Logger LOG =
 			Logger.getLogger(JdbcDatabase.class.getName());
 
 	// Different database libraries use different names for certain types
-	private final String hashType, binaryType, counterType, secretType;
+	private final String hashType, secretType, binaryType;
+	private final String counterType, stringType;
 	private final Clock clock;
 
-	private final LinkedList<Connection> connections =
-			new LinkedList<Connection>(); // Locking: connectionsLock
+	// Locking: connectionsLock
+	private final LinkedList<Connection> connections = new LinkedList<>();
 
 	private int openConnections = 0; // Locking: connectionsLock
 	private boolean closed = false; // Locking: connectionsLock
@@ -251,12 +276,13 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private final Lock connectionsLock = new ReentrantLock();
 	private final Condition connectionsChanged = connectionsLock.newCondition();
 
-	JdbcDatabase(String hashType, String binaryType, String counterType,
-			String secretType, Clock clock) {
+	JdbcDatabase(String hashType, String secretType, String binaryType,
+			String counterType, String stringType, Clock clock) {
 		this.hashType = hashType;
+		this.secretType = secretType;
 		this.binaryType = binaryType;
 		this.counterType = counterType;
-		this.secretType = secretType;
+		this.stringType = stringType;
 		this.clock = clock;
 	}
 
@@ -267,7 +293,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		} catch (ClassNotFoundException e) {
 			throw new DbException(e);
 		}
-		// Open the database and create the tables if necessary
+		// Open the database and create the tables and indexes if necessary
 		Connection txn = startTransaction();
 		try {
 			if (reopen) {
@@ -276,6 +302,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				createTables(txn);
 				storeSchemaVersion(txn);
 			}
+			createIndexes(txn);
 			commitTransaction(txn);
 		} catch (DbException e) {
 			abortTransaction(txn);
@@ -340,17 +367,35 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	private void createIndexes(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			s = txn.createStatement();
+			s.executeUpdate(INDEX_CONTACTS_BY_AUTHOR_ID);
+			s.executeUpdate(INDEX_MESSAGES_BY_GROUP_ID);
+			s.executeUpdate(INDEX_OFFERS_BY_CONTACT_ID);
+			s.executeUpdate(INDEX_GROUPS_BY_CLIENT_ID);
+			s.executeUpdate(INDEX_MESSAGE_METADATA_BY_MESSAGE_ID);
+			s.executeUpdate(INDEX_GROUP_METADATA_BY_GROUP_ID);
+			s.close();
+		} catch (SQLException e) {
+			tryToClose(s);
+			throw new DbException(e);
+		}
+	}
+
 	private String insertTypeNames(String s) {
-		s = s.replaceAll("HASH", hashType);
-		s = s.replaceAll("BINARY", binaryType);
-		s = s.replaceAll("COUNTER", counterType);
-		s = s.replaceAll("SECRET", secretType);
+		s = s.replaceAll("_HASH", hashType);
+		s = s.replaceAll("_SECRET", secretType);
+		s = s.replaceAll("_BINARY", binaryType);
+		s = s.replaceAll("_COUNTER", counterType);
+		s = s.replaceAll("_STRING", stringType);
 		return s;
 	}
 
 	@Override
 	public Connection startTransaction() throws DbException {
-		Connection txn = null;
+		Connection txn;
 		connectionsLock.lock();
 		try {
 			if (closed) throw new DbClosedException();
@@ -458,7 +503,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 		try {
 			// Create a contact row
 			String sql = "INSERT INTO contacts"
-					+ " (authorId, name, publicKey, localAuthorId, verified, active)"
+					+ " (authorId, name, publicKey, localAuthorId,"
+					+ " verified, active)"
 					+ " VALUES (?, ?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, remote.getId().getBytes());
@@ -677,7 +723,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		try {
 			// Store the incoming keys
 			String sql = "INSERT INTO incomingKeys (contactId, transportId,"
-					+ " period, tagKey, headerKey, base, bitmap)"
+					+ " rotationPeriod, tagKey, headerKey, base, bitmap)"
 					+ " VALUES (?, ?, ?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
@@ -712,8 +758,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 				if (rows != 1) throw new DbStateException();
 			ps.close();
 			// Store the outgoing keys
-			sql = "INSERT INTO outgoingKeys (contactId, transportId, period,"
-					+ " tagKey, headerKey, stream)"
+			sql = "INSERT INTO outgoingKeys (contactId, transportId,"
+					+ " rotationPeriod, tagKey, headerKey, stream)"
 					+ " VALUES (?, ?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
@@ -993,7 +1039,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " FROM contacts";
 			ps = txn.prepareStatement(sql);
 			rs = ps.executeQuery();
-			List<Contact> contacts = new ArrayList<Contact>();
+			List<Contact> contacts = new ArrayList<>();
 			while (rs.next()) {
 				ContactId contactId = new ContactId(rs.getInt(1));
 				AuthorId authorId = new AuthorId(rs.getBytes(2));
@@ -1027,7 +1073,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, local.getBytes());
 			rs = ps.executeQuery();
-			List<ContactId> ids = new ArrayList<ContactId>();
+			List<ContactId> ids = new ArrayList<>();
 			while (rs.next()) ids.add(new ContactId(rs.getInt(1)));
 			rs.close();
 			ps.close();
@@ -1052,7 +1098,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, remote.getBytes());
 			rs = ps.executeQuery();
-			List<Contact> contacts = new ArrayList<Contact>();
+			List<Contact> contacts = new ArrayList<>();
 			while (rs.next()) {
 				ContactId c = new ContactId(rs.getInt(1));
 				String name = rs.getString(2);
@@ -1108,7 +1154,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, c.getString());
 			rs = ps.executeQuery();
-			List<Group> groups = new ArrayList<Group>();
+			List<Group> groups = new ArrayList<>();
 			while (rs.next()) {
 				GroupId id = new GroupId(rs.getBytes(1));
 				byte[] descriptor = rs.getBytes(2);
@@ -1161,7 +1207,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, g.getBytes());
 			rs = ps.executeQuery();
-			List<ContactId> visible = new ArrayList<ContactId>();
+			List<ContactId> visible = new ArrayList<>();
 			while (rs.next()) visible.add(new ContactId(rs.getInt(1)));
 			rs.close();
 			ps.close();
@@ -1213,7 +1259,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " FROM localAuthors";
 			ps = txn.prepareStatement(sql);
 			rs = ps.executeQuery();
-			List<LocalAuthor> authors = new ArrayList<LocalAuthor>();
+			List<LocalAuthor> authors = new ArrayList<>();
 			while (rs.next()) {
 				AuthorId authorId = new AuthorId(rs.getBytes(1));
 				String name = rs.getString(2);
@@ -1243,7 +1289,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, g.getBytes());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<MessageId>();
+			List<MessageId> ids = new ArrayList<>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1266,7 +1312,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, state.getValue());
 			ps.setBytes(2, g.getBytes());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<MessageId>();
+			List<MessageId> ids = new ArrayList<>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1293,7 +1339,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " JOIN messageMetadata AS md"
 					+ " ON m.messageId = md.messageId"
 					+ " WHERE state = ? AND groupId = ?"
-					+ " AND key = ? AND value = ?";
+					+ " AND metaKey = ? AND value = ?";
 			for (Entry<String, byte[]> e : query.entrySet()) {
 				ps = txn.prepareStatement(sql);
 				ps.setInt(1, DELIVERED.getValue());
@@ -1301,7 +1347,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				ps.setString(3, e.getKey());
 				ps.setBytes(4, e.getValue());
 				rs = ps.executeQuery();
-				Set<MessageId> ids = new HashSet<MessageId>();
+				Set<MessageId> ids = new HashSet<>();
 				while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 				rs.close();
 				ps.close();
@@ -1325,7 +1371,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT m.messageId, key, value"
+			String sql = "SELECT m.messageId, metaKey, value"
 					+ " FROM messages AS m"
 					+ " JOIN messageMetadata AS md"
 					+ " ON m.messageId = md.messageId"
@@ -1335,7 +1381,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, DELIVERED.getValue());
 			ps.setBytes(2, g.getBytes());
 			rs = ps.executeQuery();
-			Map<MessageId, Metadata> all = new HashMap<MessageId, Metadata>();
+			Map<MessageId, Metadata> all = new HashMap<>();
 			Metadata metadata = null;
 			MessageId lastMessageId = null;
 			while (rs.next()) {
@@ -1364,8 +1410,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		Collection<MessageId> matches = getMessageIds(txn, g, query);
 		if (matches.isEmpty()) return Collections.emptyMap();
 		// Retrieve the metadata for each match
-		Map<MessageId, Metadata> all = new HashMap<MessageId, Metadata>(
-				matches.size());
+		Map<MessageId, Metadata> all = new HashMap<>(matches.size());
 		for (MessageId m : matches) all.put(m, getMessageMetadata(txn, m));
 		return all;
 	}
@@ -1376,7 +1421,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT key, value FROM groupMetadata"
+			String sql = "SELECT metaKey, value FROM groupMetadata"
 					+ " WHERE groupId = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, g.getBytes());
@@ -1399,7 +1444,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT key, value FROM messageMetadata AS md"
+			String sql = "SELECT metaKey, value FROM messageMetadata AS md"
 					+ " JOIN messages AS m"
 					+ " ON m.messageId = md.messageId"
 					+ " WHERE m.state = ? AND md.messageId = ?";
@@ -1425,7 +1470,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT key, value FROM messageMetadata AS md"
+			String sql = "SELECT metaKey, value FROM messageMetadata AS md"
 					+ " JOIN messages AS m"
 					+ " ON m.messageId = md.messageId"
 					+ " WHERE (m.state = ? OR m.state = ?)"
@@ -1463,7 +1508,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setBytes(1, g.getBytes());
 			ps.setInt(2, c.getInt());
 			rs = ps.executeQuery();
-			List<MessageStatus> statuses = new ArrayList<MessageStatus>();
+			List<MessageStatus> statuses = new ArrayList<>();
 			while (rs.next()) {
 				MessageId messageId = new MessageId(rs.getBytes(1));
 				boolean sent = rs.getBoolean(2);
@@ -1522,7 +1567,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
 			rs = ps.executeQuery();
-			Map<MessageId, State> dependencies = new HashMap<MessageId, State>();
+			Map<MessageId, State> dependencies = new HashMap<>();
 			while (rs.next()) {
 				MessageId dependency = new MessageId(rs.getBytes(1));
 				State state = State.fromValue(rs.getInt(2));
@@ -1560,7 +1605,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
 			rs = ps.executeQuery();
-			Map<MessageId, State> dependents = new HashMap<MessageId, State>();
+			Map<MessageId, State> dependents = new HashMap<>();
 			while (rs.next()) {
 				MessageId dependent = new MessageId(rs.getBytes(1));
 				State state = State.fromValue(rs.getInt(2));
@@ -1612,7 +1657,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, c.getInt());
 			ps.setInt(2, maxMessages);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<MessageId>();
+			List<MessageId> ids = new ArrayList<>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1648,7 +1693,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setLong(3, now);
 			ps.setInt(4, maxMessages);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<MessageId>();
+			List<MessageId> ids = new ArrayList<>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1673,7 +1718,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, c.getInt());
 			ps.setInt(2, maxMessages);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<MessageId>();
+			List<MessageId> ids = new ArrayList<>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1708,7 +1753,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(2, DELIVERED.getValue());
 			ps.setLong(3, now);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<MessageId>();
+			List<MessageId> ids = new ArrayList<>();
 			int total = 0;
 			while (rs.next()) {
 				int length = rs.getInt(1);
@@ -1750,7 +1795,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, state.getValue());
 			ps.setString(2, c.getString());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<MessageId>();
+			List<MessageId> ids = new ArrayList<>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1780,7 +1825,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, c.getString());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<MessageId>();
+			List<MessageId> ids = new ArrayList<>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1839,7 +1884,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(2, DELIVERED.getValue());
 			ps.setLong(3, now);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<MessageId>();
+			List<MessageId> ids = new ArrayList<>();
 			int total = 0;
 			while (rs.next()) {
 				int length = rs.getInt(1);
@@ -1863,7 +1908,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT key, value FROM settings WHERE namespace = ?";
+			String sql = "SELECT settingKey, value FROM settings"
+					+ " WHERE namespace = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, namespace);
 			rs = ps.executeQuery();
@@ -1886,14 +1932,15 @@ abstract class JdbcDatabase implements Database<Connection> {
 		ResultSet rs = null;
 		try {
 			// Retrieve the incoming keys
-			String sql = "SELECT period, tagKey, headerKey, base, bitmap"
+			String sql = "SELECT rotationPeriod, tagKey, headerKey,"
+					+ " base, bitmap"
 					+ " FROM incomingKeys"
 					+ " WHERE transportId = ?"
-					+ " ORDER BY contactId, period";
+					+ " ORDER BY contactId, rotationPeriod";
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, t.getString());
 			rs = ps.executeQuery();
-			List<IncomingKeys> inKeys = new ArrayList<IncomingKeys>();
+			List<IncomingKeys> inKeys = new ArrayList<>();
 			while (rs.next()) {
 				long rotationPeriod = rs.getLong(1);
 				SecretKey tagKey = new SecretKey(rs.getBytes(2));
@@ -1906,15 +1953,14 @@ abstract class JdbcDatabase implements Database<Connection> {
 			rs.close();
 			ps.close();
 			// Retrieve the outgoing keys in the same order
-			sql = "SELECT contactId, period, tagKey, headerKey, stream"
+			sql = "SELECT contactId, rotationPeriod, tagKey, headerKey, stream"
 					+ " FROM outgoingKeys"
 					+ " WHERE transportId = ?"
-					+ " ORDER BY contactId, period";
+					+ " ORDER BY contactId, rotationPeriod";
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, t.getString());
 			rs = ps.executeQuery();
-			Map<ContactId, TransportKeys> keys =
-					new HashMap<ContactId, TransportKeys>();
+			Map<ContactId, TransportKeys> keys = new HashMap<>();
 			for (int i = 0; rs.next(); i++) {
 				// There should be three times as many incoming keys
 				if (inKeys.size() < (i + 1) * 3) throw new DbStateException();
@@ -1947,7 +1993,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		try {
 			String sql = "UPDATE outgoingKeys SET stream = stream + 1"
-					+ " WHERE contactId = ? AND transportId = ? AND period = ?";
+					+ " WHERE contactId = ? AND transportId = ?"
+					+ " AND rotationPeriod = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
 			ps.setString(2, t.getString());
@@ -2032,8 +2079,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		try {
 			// Determine which keys are being removed
-			List<String> removed = new ArrayList<String>();
-			Map<String, byte[]> retained = new HashMap<String, byte[]>();
+			List<String> removed = new ArrayList<>();
+			Map<String, byte[]> retained = new HashMap<>();
 			for (Entry<String, byte[]> e : meta.entrySet()) {
 				if (e.getValue() == REMOVE) removed.add(e.getKey());
 				else retained.put(e.getKey(), e.getValue());
@@ -2041,7 +2088,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			// Delete any keys that are being removed
 			if (!removed.isEmpty()) {
 				String sql = "DELETE FROM " + tableName
-						+ " WHERE " + columnName + " = ? AND key = ?";
+						+ " WHERE " + columnName + " = ? AND metaKey = ?";
 				ps = txn.prepareStatement(sql);
 				ps.setBytes(1, id);
 				for (String key : removed) {
@@ -2060,7 +2107,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (retained.isEmpty()) return;
 			// Update any keys that already exist
 			String sql = "UPDATE " + tableName + " SET value = ?"
-					+ " WHERE " + columnName + " = ? AND key = ?";
+					+ " WHERE " + columnName + " = ? AND metaKey = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(2, id);
 			for (Entry<String, byte[]> e : retained.entrySet()) {
@@ -2077,7 +2124,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			}
 			// Insert any keys that don't already exist
 			sql = "INSERT INTO " + tableName
-					+ " (" + columnName + ", key, value)"
+					+ " (" + columnName + ", metaKey, value)"
 					+ " VALUES (?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, id);
@@ -2109,7 +2156,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		try {
 			// Update any settings that already exist
 			String sql = "UPDATE settings SET value = ?"
-					+ " WHERE namespace = ? AND key = ?";
+					+ " WHERE namespace = ? AND settingKey = ?";
 			ps = txn.prepareStatement(sql);
 			for (Entry<String, String> e : s.entrySet()) {
 				ps.setString(1, e.getValue());
@@ -2124,7 +2171,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				if (rows > 1) throw new DbStateException();
 			}
 			// Insert any settings that don't already exist
-			sql = "INSERT INTO settings (namespace, key, value)"
+			sql = "INSERT INTO settings (namespace, settingKey, value)"
 					+ " VALUES (?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			int updateIndex = 0, inserted = 0;
@@ -2488,7 +2535,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		try {
 			String sql = "UPDATE incomingKeys SET base = ?, bitmap = ?"
-					+ " WHERE contactId = ? AND transportId = ? AND period = ?";
+					+ " WHERE contactId = ? AND transportId = ?"
+					+ " AND rotationPeriod = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setLong(1, base);
 			ps.setBytes(2, bitmap);

bramble-core/src/main/java/org/briarproject/bramble/event/EventBusImpl.java

@@ -15,7 +15,7 @@ import javax.annotation.concurrent.ThreadSafe;
 class EventBusImpl implements EventBus {
 
 	private final Collection<EventListener> listeners =
-			new CopyOnWriteArrayList<EventListener>();
+			new CopyOnWriteArrayList<>();
 
 	@Override
 	public void addListener(EventListener l) {

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

@@ -1,119 +0,0 @@
-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

@@ -1,119 +0,0 @@
-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

@@ -1,150 +0,0 @@
-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

@@ -1,278 +0,0 @@
-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

@@ -1,16 +0,0 @@
-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

@@ -1,47 +0,0 @@
-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/keyagreement/KeyAgreementConnector.java

@@ -1,6 +1,6 @@
 package org.briarproject.bramble.keyagreement;
 
-import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.KeyAgreementCrypto;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
@@ -46,37 +46,34 @@ class KeyAgreementConnector {
 
 	private final Callbacks callbacks;
 	private final Clock clock;
-	private final CryptoComponent crypto;
+	private final KeyAgreementCrypto keyAgreementCrypto;
 	private final PluginManager pluginManager;
 	private final CompletionService<KeyAgreementConnection> connect;
 
-	private final List<KeyAgreementListener> listeners =
-			new ArrayList<KeyAgreementListener>();
+	private final List<KeyAgreementListener> listeners = new ArrayList<>();
 	private final List<Future<KeyAgreementConnection>> pending =
-			new ArrayList<Future<KeyAgreementConnection>>();
+			new ArrayList<>();
 
 	private volatile boolean connecting = false;
 	private volatile boolean alice = false;
 
 	KeyAgreementConnector(Callbacks callbacks, Clock clock,
-			CryptoComponent crypto, PluginManager pluginManager,
+			KeyAgreementCrypto keyAgreementCrypto, PluginManager pluginManager,
 			Executor ioExecutor) {
 		this.callbacks = callbacks;
 		this.clock = clock;
-		this.crypto = crypto;
+		this.keyAgreementCrypto = keyAgreementCrypto;
 		this.pluginManager = pluginManager;
-		connect = new ExecutorCompletionService<KeyAgreementConnection>(
-				ioExecutor);
+		connect = new ExecutorCompletionService<>(ioExecutor);
 	}
 
 	public Payload listen(KeyPair localKeyPair) {
 		LOG.info("Starting BQP listeners");
 		// Derive commitment
-		byte[] commitment = crypto.deriveKeyCommitment(
-				localKeyPair.getPublic().getEncoded());
+		byte[] commitment = keyAgreementCrypto.deriveKeyCommitment(
+				localKeyPair.getPublic());
 		// Start all listeners and collect their descriptors
-		List<TransportDescriptor> descriptors =
-				new ArrayList<TransportDescriptor>();
+		List<TransportDescriptor> descriptors = new ArrayList<>();
 		for (DuplexPlugin plugin : pluginManager.getKeyAgreementPlugins()) {
 			KeyAgreementListener l =
 					plugin.createKeyAgreementListener(commitment);
@@ -132,10 +129,7 @@ class KeyAgreementConnector {
 			LOG.info("Interrupted while waiting for connection");
 			Thread.currentThread().interrupt();
 			return null;
-		} catch (ExecutionException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-			return null;
-		} catch (IOException e) {
+		} catch (ExecutionException | IOException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			return null;
 		} finally {

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementModule.java

@@ -1,19 +1,10 @@
 package org.briarproject.bramble.keyagreement;
 
-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.event.EventBus;
-import org.briarproject.bramble.api.keyagreement.KeyAgreementTaskFactory;
+import org.briarproject.bramble.api.keyagreement.KeyAgreementTask;
 import org.briarproject.bramble.api.keyagreement.PayloadEncoder;
 import org.briarproject.bramble.api.keyagreement.PayloadParser;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.plugin.PluginManager;
-import org.briarproject.bramble.api.system.Clock;
-
-import java.util.concurrent.Executor;
-
-import javax.inject.Singleton;
 
 import dagger.Module;
 import dagger.Provides;
@@ -22,13 +13,9 @@ import dagger.Provides;
 public class KeyAgreementModule {
 
 	@Provides
-	@Singleton
-	KeyAgreementTaskFactory provideKeyAgreementTaskFactory(Clock clock,
-			CryptoComponent crypto, EventBus eventBus,
-			@IoExecutor Executor ioExecutor, PayloadEncoder payloadEncoder,
-			PluginManager pluginManager) {
-		return new KeyAgreementTaskFactoryImpl(clock, crypto, eventBus,
-				ioExecutor, payloadEncoder, pluginManager);
+	KeyAgreementTask provideKeyAgreementTask(
+			KeyAgreementTaskImpl keyAgreementTask) {
+		return keyAgreementTask;
 	}
 
 	@Provides

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementProtocol.java

@@ -1,7 +1,10 @@
 package org.briarproject.bramble.keyagreement;
 
 import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.KeyAgreementCrypto;
 import org.briarproject.bramble.api.crypto.KeyPair;
+import org.briarproject.bramble.api.crypto.KeyParser;
+import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.keyagreement.Payload;
 import org.briarproject.bramble.api.keyagreement.PayloadEncoder;
@@ -11,6 +14,10 @@ import java.io.IOException;
 import java.security.GeneralSecurityException;
 import java.util.Arrays;
 
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.MASTER_SECRET_LABEL;
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.SHARED_SECRET_LABEL;
+
 /**
  * Implementation of the BQP protocol.
  * <p/>
@@ -57,6 +64,7 @@ class KeyAgreementProtocol {
 
 	private final Callbacks callbacks;
 	private final CryptoComponent crypto;
+	private final KeyAgreementCrypto keyAgreementCrypto;
 	private final PayloadEncoder payloadEncoder;
 	private final KeyAgreementTransport transport;
 	private final Payload theirPayload, ourPayload;
@@ -64,11 +72,13 @@ class KeyAgreementProtocol {
 	private final boolean alice;
 
 	KeyAgreementProtocol(Callbacks callbacks, CryptoComponent crypto,
+			KeyAgreementCrypto keyAgreementCrypto,
 			PayloadEncoder payloadEncoder, KeyAgreementTransport transport,
 			Payload theirPayload, Payload ourPayload, KeyPair ourKeyPair,
 			boolean alice) {
 		this.callbacks = callbacks;
 		this.crypto = crypto;
+		this.keyAgreementCrypto = keyAgreementCrypto;
 		this.payloadEncoder = payloadEncoder;
 		this.transport = transport;
 		this.theirPayload = theirPayload;
@@ -86,7 +96,7 @@ class KeyAgreementProtocol {
 	 */
 	SecretKey perform() throws AbortException, IOException {
 		try {
-			byte[] theirPublicKey;
+			PublicKey theirPublicKey;
 			if (alice) {
 				sendKey();
 				// Alice waits here until Bob obtains her payload.
@@ -104,7 +114,7 @@ class KeyAgreementProtocol {
 				receiveConfirm(s, theirPublicKey);
 				sendConfirm(s, theirPublicKey);
 			}
-			return crypto.deriveMasterSecret(s);
+			return crypto.deriveKey(MASTER_SECRET_LABEL, s);
 		} catch (AbortException e) {
 			sendAbort(e.getCause() != null);
 			throw e;
@@ -115,27 +125,41 @@ class KeyAgreementProtocol {
 		transport.sendKey(ourKeyPair.getPublic().getEncoded());
 	}
 
-	private byte[] receiveKey() throws AbortException {
-		byte[] publicKey = transport.receiveKey();
+	private PublicKey receiveKey() throws AbortException {
+		byte[] publicKeyBytes = transport.receiveKey();
 		callbacks.initialRecordReceived();
-		byte[] expected = crypto.deriveKeyCommitment(publicKey);
-		if (!Arrays.equals(expected, theirPayload.getCommitment()))
+		KeyParser keyParser = crypto.getAgreementKeyParser();
+		try {
+			PublicKey publicKey = keyParser.parsePublicKey(publicKeyBytes);
+			byte[] expected = keyAgreementCrypto.deriveKeyCommitment(publicKey);
+			if (!Arrays.equals(expected, theirPayload.getCommitment()))
+				throw new AbortException();
+			return publicKey;
+		} catch (GeneralSecurityException e) {
 			throw new AbortException();
-		return publicKey;
+		}
 	}
 
-	private SecretKey deriveSharedSecret(byte[] theirPublicKey)
+	private SecretKey deriveSharedSecret(PublicKey theirPublicKey)
 			throws AbortException {
 		try {
-			return crypto.deriveSharedSecret(theirPublicKey, ourKeyPair, alice);
+			byte[] ourPublicKeyBytes = ourKeyPair.getPublic().getEncoded();
+			byte[] theirPublicKeyBytes = theirPublicKey.getEncoded();
+			byte[][] inputs = {
+					new byte[] {PROTOCOL_VERSION},
+					alice ? ourPublicKeyBytes : theirPublicKeyBytes,
+					alice ? theirPublicKeyBytes : ourPublicKeyBytes
+			};
+			return crypto.deriveSharedSecret(SHARED_SECRET_LABEL,
+					theirPublicKey, ourKeyPair, inputs);
 		} catch (GeneralSecurityException e) {
 			throw new AbortException(e);
 		}
 	}
 
-	private void sendConfirm(SecretKey s, byte[] theirPublicKey)
+	private void sendConfirm(SecretKey s, PublicKey theirPublicKey)
 			throws IOException {
-		byte[] confirm = crypto.deriveConfirmationRecord(s,
+		byte[] confirm = keyAgreementCrypto.deriveConfirmationRecord(s,
 				payloadEncoder.encode(theirPayload),
 				payloadEncoder.encode(ourPayload),
 				theirPublicKey, ourKeyPair,
@@ -143,10 +167,10 @@ class KeyAgreementProtocol {
 		transport.sendConfirm(confirm);
 	}
 
-	private void receiveConfirm(SecretKey s, byte[] theirPublicKey)
+	private void receiveConfirm(SecretKey s, PublicKey theirPublicKey)
 			throws AbortException {
 		byte[] confirm = transport.receiveConfirm();
-		byte[] expected = crypto.deriveConfirmationRecord(s,
+		byte[] expected = keyAgreementCrypto.deriveConfirmationRecord(s,
 				payloadEncoder.encode(theirPayload),
 				payloadEncoder.encode(ourPayload),
 				theirPublicKey, ourKeyPair,

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementTaskFactoryImpl.java

@@ -1,46 +0,0 @@
-package org.briarproject.bramble.keyagreement;
-
-import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.keyagreement.KeyAgreementTask;
-import org.briarproject.bramble.api.keyagreement.KeyAgreementTaskFactory;
-import org.briarproject.bramble.api.keyagreement.PayloadEncoder;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.PluginManager;
-import org.briarproject.bramble.api.system.Clock;
-
-import java.util.concurrent.Executor;
-
-import javax.annotation.concurrent.Immutable;
-import javax.inject.Inject;
-
-@Immutable
-@NotNullByDefault
-class KeyAgreementTaskFactoryImpl implements KeyAgreementTaskFactory {
-
-	private final Clock clock;
-	private final CryptoComponent crypto;
-	private final EventBus eventBus;
-	private final Executor ioExecutor;
-	private final PayloadEncoder payloadEncoder;
-	private final PluginManager pluginManager;
-
-	@Inject
-	KeyAgreementTaskFactoryImpl(Clock clock, CryptoComponent crypto,
-			EventBus eventBus, @IoExecutor Executor ioExecutor,
-			PayloadEncoder payloadEncoder, PluginManager pluginManager) {
-		this.clock = clock;
-		this.crypto = crypto;
-		this.eventBus = eventBus;
-		this.ioExecutor = ioExecutor;
-		this.payloadEncoder = payloadEncoder;
-		this.pluginManager = pluginManager;
-	}
-
-	@Override
-	public KeyAgreementTask createTask() {
-		return new KeyAgreementTaskImpl(clock, crypto, eventBus, payloadEncoder,
-				pluginManager, ioExecutor);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/KeyAgreementTaskImpl.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.keyagreement;
 
 import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.KeyAgreementCrypto;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.event.EventBus;
@@ -14,6 +15,7 @@ import org.briarproject.bramble.api.keyagreement.event.KeyAgreementFinishedEvent
 import org.briarproject.bramble.api.keyagreement.event.KeyAgreementListeningEvent;
 import org.briarproject.bramble.api.keyagreement.event.KeyAgreementStartedEvent;
 import org.briarproject.bramble.api.keyagreement.event.KeyAgreementWaitingEvent;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.PluginManager;
@@ -23,6 +25,8 @@ import java.io.IOException;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
+import javax.inject.Inject;
+
 import static java.util.logging.Level.WARNING;
 
 @MethodsNotNullByDefault
@@ -35,6 +39,7 @@ class KeyAgreementTaskImpl extends Thread implements
 			Logger.getLogger(KeyAgreementTaskImpl.class.getName());
 
 	private final CryptoComponent crypto;
+	private final KeyAgreementCrypto keyAgreementCrypto;
 	private final EventBus eventBus;
 	private final PayloadEncoder payloadEncoder;
 	private final KeyPair localKeyPair;
@@ -43,14 +48,17 @@ class KeyAgreementTaskImpl extends Thread implements
 	private Payload localPayload;
 	private Payload remotePayload;
 
+	@Inject
 	KeyAgreementTaskImpl(Clock clock, CryptoComponent crypto,
-			EventBus eventBus, PayloadEncoder payloadEncoder,
-			PluginManager pluginManager, Executor ioExecutor) {
+			KeyAgreementCrypto keyAgreementCrypto, EventBus eventBus,
+			PayloadEncoder payloadEncoder, PluginManager pluginManager,
+			@IoExecutor Executor ioExecutor) {
 		this.crypto = crypto;
+		this.keyAgreementCrypto = keyAgreementCrypto;
 		this.eventBus = eventBus;
 		this.payloadEncoder = payloadEncoder;
 		localKeyPair = crypto.generateAgreementKeyPair();
-		connector = new KeyAgreementConnector(this, clock, crypto,
+		connector = new KeyAgreementConnector(this, clock, keyAgreementCrypto,
 				pluginManager, ioExecutor);
 	}
 
@@ -100,8 +108,8 @@ class KeyAgreementTaskImpl extends Thread implements
 		// Run BQP protocol over the connection
 		LOG.info("Starting BQP protocol");
 		KeyAgreementProtocol protocol = new KeyAgreementProtocol(this, crypto,
-				payloadEncoder, transport, remotePayload, localPayload,
-				localKeyPair, alice);
+				keyAgreementCrypto, payloadEncoder, transport, remotePayload,
+				localPayload, localKeyPair, alice);
 		try {
 			SecretKey master = protocol.perform();
 			KeyAgreementResult result =

bramble-core/src/main/java/org/briarproject/bramble/keyagreement/PayloadParserImpl.java

@@ -51,8 +51,7 @@ class PayloadParserImpl implements PayloadParser {
 		byte[] commitment = payload.getRaw(1);
 		if (commitment.length != COMMIT_LENGTH) throw new FormatException();
 		// Remaining elements: transport descriptors
-		List<TransportDescriptor> recognised =
-				new ArrayList<TransportDescriptor>();
+		List<TransportDescriptor> recognised = new ArrayList<>();
 		for (int i = 2; i < payload.size(); i++) {
 			BdfList descriptor = payload.getList(i);
 			long transportId = descriptor.getLong(0);

bramble-core/src/main/java/org/briarproject/bramble/lifecycle/LifecycleManagerImpl.java

@@ -63,9 +63,9 @@ class LifecycleManagerImpl implements LifecycleManager {
 		this.crypto = crypto;
 		this.authorFactory = authorFactory;
 		this.identityManager = identityManager;
-		services = new CopyOnWriteArrayList<Service>();
-		clients = new CopyOnWriteArrayList<Client>();
-		executors = new CopyOnWriteArrayList<ExecutorService>();
+		services = new CopyOnWriteArrayList<>();
+		clients = new CopyOnWriteArrayList<>();
+		executors = new CopyOnWriteArrayList<>();
 	}
 
 	@Override
@@ -88,7 +88,7 @@ class LifecycleManagerImpl implements LifecycleManager {
 		executors.add(e);
 	}
 
-	private LocalAuthor createLocalAuthor(final String nickname) {
+	private LocalAuthor createLocalAuthor(String nickname) {
 		long now = System.currentTimeMillis();
 		KeyPair keyPair = crypto.generateSignatureKeyPair();
 		byte[] publicKey = keyPair.getPublic().getEncoded();
@@ -203,9 +203,7 @@ class LifecycleManagerImpl implements LifecycleManager {
 			if (LOG.isLoggable(INFO))
 				LOG.info("Closing database took " + duration + " ms");
 			shutdownLatch.countDown();
-		} catch (DbException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-		} catch (ServiceException e) {
+		} catch (DbException | ServiceException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 		} finally {
 			startStopSemaphore.release();

bramble-core/src/main/java/org/briarproject/bramble/lifecycle/LifecycleModule.java

@@ -37,7 +37,7 @@ public class LifecycleModule {
 
 	public LifecycleModule() {
 		// The thread pool is unbounded, so use direct handoff
-		BlockingQueue<Runnable> queue = new SynchronousQueue<Runnable>();
+		BlockingQueue<Runnable> queue = new SynchronousQueue<>();
 		// Discard tasks that are submitted during shutdown
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();

bramble-core/src/main/java/org/briarproject/bramble/lifecycle/ShutdownManagerImpl.java

@@ -21,7 +21,7 @@ class ShutdownManagerImpl implements ShutdownManager {
 	private int nextHandle = 0;
 
 	ShutdownManagerImpl() {
-		hooks = new HashMap<Integer, Thread>();
+		hooks = new HashMap<>();
 	}
 
 	@Override

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

@@ -134,11 +134,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 			try {
 				byte[] tag = readTag(reader);
 				ctx = keyManager.getStreamContext(transportId, tag);
-			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-				disposeReader(true, false);
-				return;
-			} catch (DbException e) {
+			} catch (IOException | DbException e) {
 				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 				disposeReader(true, false);
 				return;
@@ -249,11 +245,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 			try {
 				byte[] tag = readTag(reader);
 				ctx = keyManager.getStreamContext(transportId, tag);
-			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-				disposeReader(true, false);
-				return;
-			} catch (DbException e) {
+			} catch (IOException | DbException e) {
 				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 				disposeReader(true, false);
 				return;
@@ -266,12 +258,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 			contactId = ctx.getContactId();
 			connectionRegistry.registerConnection(contactId, transportId, true);
 			// Start the outgoing session on another thread
-			ioExecutor.execute(new Runnable() {
-				@Override
-				public void run() {
-					runOutgoingSession();
-				}
-			});
+			ioExecutor.execute(this::runOutgoingSession);
 			try {
 				// Create and run the incoming session
 				incomingSession = createIncomingSession(ctx, reader);
@@ -368,12 +355,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 				return;
 			}
 			// Start the incoming session on another thread
-			ioExecutor.execute(new Runnable() {
-				@Override
-				public void run() {
-					runIncomingSession();
-				}
-			});
+			ioExecutor.execute(this::runIncomingSession);
 			try {
 				// Create and run the outgoing session
 				outgoingSession = createDuplexOutgoingSession(ctx, writer);
@@ -391,11 +373,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 			try {
 				byte[] tag = readTag(reader);
 				ctx = keyManager.getStreamContext(transportId, tag);
-			} catch (IOException e) {
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-				disposeReader(true, false);
-				return;
-			} catch (DbException e) {
+			} catch (IOException | DbException e) {
 				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 				disposeReader(true, false);
 				return;

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

@@ -42,8 +42,8 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 	@Inject
 	ConnectionRegistryImpl(EventBus eventBus) {
 		this.eventBus = eventBus;
-		connections = new HashMap<TransportId, Map<ContactId, Integer>>();
-		contactCounts = new HashMap<ContactId, Integer>();
+		connections = new HashMap<>();
+		contactCounts = new HashMap<>();
 	}
 
 	@Override
@@ -58,7 +58,7 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 		try {
 			Map<ContactId, Integer> m = connections.get(t);
 			if (m == null) {
-				m = new HashMap<ContactId, Integer>();
+				m = new HashMap<>();
 				connections.put(t, m);
 			}
 			Integer count = m.get(c);
@@ -124,7 +124,7 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 		try {
 			Map<ContactId, Integer> m = connections.get(t);
 			if (m == null) return Collections.emptyList();
-			List<ContactId> ids = new ArrayList<ContactId>(m.keySet());
+			List<ContactId> ids = new ArrayList<>(m.keySet());
 			if (LOG.isLoggable(INFO))
 				LOG.info(ids.size() + " contacts connected");
 			return ids;

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

@@ -82,10 +82,10 @@ class PluginManagerImpl implements PluginManager, Service {
 		this.settingsManager = settingsManager;
 		this.transportPropertyManager = transportPropertyManager;
 		this.uiCallback = uiCallback;
-		plugins = new ConcurrentHashMap<TransportId, Plugin>();
-		simplexPlugins = new CopyOnWriteArrayList<SimplexPlugin>();
-		duplexPlugins = new CopyOnWriteArrayList<DuplexPlugin>();
-		startLatches = new ConcurrentHashMap<TransportId, CountDownLatch>();
+		plugins = new ConcurrentHashMap<>();
+		simplexPlugins = new CopyOnWriteArrayList<>();
+		duplexPlugins = new CopyOnWriteArrayList<>();
+		startLatches = new ConcurrentHashMap<>();
 	}
 
 	@Override
@@ -156,25 +156,17 @@ class PluginManagerImpl implements PluginManager, Service {
 
 	@Override
 	public Collection<SimplexPlugin> getSimplexPlugins() {
-		return new ArrayList<SimplexPlugin>(simplexPlugins);
+		return new ArrayList<>(simplexPlugins);
 	}
 
 	@Override
 	public Collection<DuplexPlugin> getDuplexPlugins() {
-		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;
+		return new ArrayList<>(duplexPlugins);
 	}
 
 	@Override
 	public Collection<DuplexPlugin> getKeyAgreementPlugins() {
-		List<DuplexPlugin> supported = new ArrayList<DuplexPlugin>();
+		List<DuplexPlugin> supported = new ArrayList<>();
 		for (DuplexPlugin d : duplexPlugins)
 			if (d.supportsKeyAgreement()) supported.add(d);
 		return supported;
@@ -291,6 +283,16 @@ 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/Poller.java

@@ -66,7 +66,7 @@ class Poller implements EventListener {
 		this.random = random;
 		this.clock = clock;
 		lock = new ReentrantLock();
-		tasks = new HashMap<TransportId, PollTask>();
+		tasks = new HashMap<>();
 	}
 
 	@Override
@@ -111,30 +111,24 @@ class Poller implements EventListener {
 			connectToContact(c, (DuplexPlugin) p);
 	}
 
-	private void connectToContact(final ContactId c, final SimplexPlugin p) {
-		ioExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				TransportId t = p.getId();
-				if (!connectionRegistry.isConnected(c, t)) {
-					TransportConnectionWriter w = p.createWriter(c);
-					if (w != null)
-						connectionManager.manageOutgoingConnection(c, t, w);
-				}
+	private void connectToContact(ContactId c, SimplexPlugin p) {
+		ioExecutor.execute(() -> {
+			TransportId t = p.getId();
+			if (!connectionRegistry.isConnected(c, t)) {
+				TransportConnectionWriter w = p.createWriter(c);
+				if (w != null)
+					connectionManager.manageOutgoingConnection(c, t, w);
 			}
 		});
 	}
 
-	private void connectToContact(final ContactId c, final DuplexPlugin p) {
-		ioExecutor.execute(new Runnable() {
-			@Override
-			public void run() {
-				TransportId t = p.getId();
-				if (!connectionRegistry.isConnected(c, t)) {
-					DuplexTransportConnection d = p.createConnection(c);
-					if (d != null)
-						connectionManager.manageOutgoingConnection(c, t, d);
-				}
+	private void connectToContact(ContactId c, DuplexPlugin p) {
+		ioExecutor.execute(() -> {
+			TransportId t = p.getId();
+			if (!connectionRegistry.isConnected(c, t)) {
+				DuplexTransportConnection d = p.createConnection(c);
+				if (d != null)
+					connectionManager.manageOutgoingConnection(c, t, d);
 			}
 		});
 	}
@@ -159,14 +153,10 @@ class Poller implements EventListener {
 		try {
 			PollTask scheduled = tasks.get(t);
 			if (scheduled == null || due < scheduled.due) {
-				final PollTask task = new PollTask(p, due, randomiseNext);
+				PollTask task = new PollTask(p, due, randomiseNext);
 				tasks.put(t, task);
-				scheduler.schedule(new Runnable() {
-					@Override
-					public void run() {
-						ioExecutor.execute(task);
-					}
-				}, delay, MILLISECONDS);
+				scheduler.schedule(
+						() -> ioExecutor.execute(task), delay, MILLISECONDS);
 			}
 		} finally {
 			lock.unlock();
@@ -174,7 +164,7 @@ class Poller implements EventListener {
 	}
 
 	@IoExecutor
-	private void poll(final Plugin p) {
+	private void poll(Plugin p) {
 		TransportId t = p.getId();
 		if (LOG.isLoggable(INFO)) LOG.info("Polling plugin " + t);
 		p.poll(connectionRegistry.getConnectedContacts(t));