WIP: BluetoothPlugin: adds abstract superclass

The droidtooth plugin and bluetooth plugins share a lot of common code.
Add an abstract superclass that shares the common code between both
classes.

.gitlab-ci.yml

@@ -1,29 +0,0 @@
-image: registry.gitlab.com/fdroid/ci-images-base:latest
-
-cache:
-  paths:
-    - .gradle/wrapper
-    - .gradle/caches
-
-before_script:
-  - set -e
-  - export GRADLE_USER_HOME=$PWD/.gradle
-  # Accept the license for the Android build tools
-  - echo y | /opt/android-sdk/tools/bin/sdkmanager "build-tools;26.0.2"
-  # Download OpenJDK 6 so we can compile against its standard library
-  - JDK_FILE=openjdk-6-jre-headless_6b38-1.13.10-1~deb7u1_amd64.deb
-  - if [ ! -d openjdk ]
-  - then
-  - wget -q http://ftp.uk.debian.org/debian/pool/main/o/openjdk-6/$JDK_FILE
-  - dpkg-deb -x $JDK_FILE openjdk
-  - fi
-  - export JAVA_6_HOME=$PWD/openjdk/usr/lib/jvm/java-6-openjdk-amd64
-
-test:
-  script:
-    - ./gradlew test
-
-after_script:
-    # this file changes every time but should not be cached
-    - rm -f $GRADLE_USER_HOME/caches/modules-2/modules-2.lock
-    - rm -fr $GRADLE_USER_HOME/caches/*/plugin-resolution/

bramble-android/build.gradle

@@ -6,91 +6,99 @@ apply plugin: 'witness'
 apply plugin: 'de.undercouch.download'
 
 android {
-	compileSdkVersion 27
+	compileSdkVersion 23
-	buildToolsVersion '26.0.2'
+	buildToolsVersion "23.0.3"
 
 	defaultConfig {
 		minSdkVersion 14
-		targetSdkVersion 26
+		targetSdkVersion 22
-		versionCode 1700
+		versionCode 1
-		versionName "0.17.0"
+		versionName "1.0"
 		consumerProguardFiles 'proguard-rules.txt'
 	}
 
 	compileOptions {
-		sourceCompatibility JavaVersion.VERSION_1_8
+		sourceCompatibility JavaVersion.VERSION_1_7
-		targetCompatibility JavaVersion.VERSION_1_8
+		targetCompatibility JavaVersion.VERSION_1_7
 	}
 }
 
 dependencies {
-	implementation project(path: ':bramble-core', configuration: 'default')
+	compile project(':bramble-core')
-	implementation fileTree(dir: 'libs', include: '*.jar')
+	compile fileTree(dir: 'libs', include: ['*.jar'])
-
+	provided 'javax.annotation:jsr250-api:1.0'
-	annotationProcessor 'com.google.dagger:dagger-compiler:2.0.2'
-
-	compileOnly 'javax.annotation:jsr250-api:1.0'
 }
 
-dependencyVerification {
+def torBinaryDir = 'src/main/res/raw'
-	verify = [
+
-			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+task downloadTorGeoIp(type: Download) {
-			'com.google.dagger:dagger-compiler:2.0.2:dagger-compiler-2.0.2.jar:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
+	src 'https://briarproject.org/build/geoip-2015-12-01.zip'
-			'com.google.dagger:dagger-producers:2.0-beta:dagger-producers-2.0-beta.jar:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
+	dest "$torBinaryDir/geoip.zip"
-			'com.google.dagger:dagger:2.0.2:dagger-2.0.2.jar:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
+	onlyIfNewer true
-			'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',
-	]
 }
 
-ext.torBinaryDir = 'src/main/res/raw'
+task downloadTorBinaryArm(type: Download) {
-ext.torVersion = '0.2.9.12'
+	src 'https://briarproject.org/build/tor-0.2.7.6-arm.zip'
-ext.geoipVersion = '2017-09-06'
+	dest "$torBinaryDir/tor_arm.zip"
-ext.torDownloadUrl = 'https://briarproject.org/build/'
+	onlyIfNewer true
-
-def torBinaries = [
-		"tor_arm"    : '8ed0b347ffed1d6a4d2fd14495118eb92be83e9cc06e057e15220dc288b31688',
-		"tor_arm_pie": '64403262511c29f462ca5e7c7621bfc3c944898364d1d5ad35a016bb8a034283',
-		"tor_x86"    : '61e014607a2079bcf1646289c67bff6372b1aded6e1d8d83d7791efda9a4d5ab',
-		"tor_x86_pie": '18fbc98356697dd0895836ab46d5c9877d1c539193464f7db1e82a65adaaf288',
-		"geoip"      : 'fe49d3adb86d3c512373101422a017dbb86c85a570524663f09dd8ce143a24f3'
-]
-
-def downloadBinary(name) {
-	return tasks.create("downloadBinary${name}", Download) {
-		src "${torDownloadUrl}${name}.zip"
-				.replace('tor_', "tor-${torVersion}-")
-				.replace('geoip', "geoip-${geoipVersion}")
-				.replaceAll('_', '-')
-		dest "${torBinaryDir}/${name}.zip"
-		onlyIfNewer true
-	}
 }
 
-def verifyBinary(name, chksum) {
+task downloadTorBinaryArmPie(type: Download) {
-	return tasks.create([
+	src 'https://briarproject.org/build/tor-0.2.7.6-arm-pie.zip'
-			name     : "verifyBinary${name}",
+	dest "$torBinaryDir/tor_arm_pie.zip"
-			type     : Verify,
+	onlyIfNewer true
-			dependsOn: downloadBinary(name)]) {
+}
-		src "${torBinaryDir}/${name}.zip"
+
-		algorithm 'SHA-256'
+task downloadTorBinaryX86(type: Download) {
-		checksum chksum
+	src 'https://briarproject.org/build/tor-0.2.7.6-x86.zip'
-	}
+	dest "$torBinaryDir/tor_x86.zip"
+	onlyIfNewer true
+}
+
+task downloadTorBinaryX86Pie(type: Download) {
+	src 'https://briarproject.org/build/tor-0.2.7.6-x86-pie.zip'
+	dest "$torBinaryDir/tor_x86_pie.zip"
+	onlyIfNewer true
+}
+
+task verifyTorGeoIp(type: Verify, dependsOn: 'downloadTorGeoIp') {
+	src "$torBinaryDir/geoip.zip"
+	algorithm 'SHA-256'
+	checksum '9bcdaf0a7ba0933735328d8ec466c25c25dbb459efc2bce9e55c774eabea5162'
+}
+
+task verifyTorBinaryArm(type: Verify, dependsOn: 'downloadTorBinaryArm') {
+	src "$torBinaryDir/tor_arm.zip"
+	algorithm 'SHA-256'
+	checksum '83272962eda701cd5d74d2418651c4ff0f0b1dff51f558a292d1a1c42bf12146'
+}
+
+task verifyTorBinaryArmPie(type: Verify, dependsOn: 'downloadTorBinaryArmPie') {
+	src "$torBinaryDir/tor_arm_pie.zip"
+	algorithm 'SHA-256'
+	checksum 'd0300d1e45de11ebb24ed62b9c492be9c2e88590b7822195ab38c7a76ffcf646'
+}
+
+task verifyTorBinaryX86(type: Verify, dependsOn: 'downloadTorBinaryX86') {
+	src "$torBinaryDir/tor_x86.zip"
+	algorithm 'SHA-256'
+	checksum 'b8813d97b01ee1b9c9a4233c1b9bbe9f9f6b494ae6f9cbd84de8a3911911615e'
+}
+
+task verifyTorBinaryX86Pie(type: Verify, dependsOn: 'downloadTorBinaryX86Pie') {
+	src "$torBinaryDir/tor_x86_pie.zip"
+	algorithm 'SHA-256'
+	checksum '9c66e765aa196dc089951a1b2140cc8290305c2fcbf365121f99e01a233baf4e'
 }
 
 project.afterEvaluate {
-	torBinaries.every { key, value ->
+	preBuild.dependsOn {
-		preBuild.dependsOn.add(verifyBinary(key, value))
+		[
+				'verifyTorGeoIp',
+				'verifyTorBinaryArm',
+				'verifyTorBinaryArmPie',
+				'verifyTorBinaryX86',
+				'verifyTorBinaryX86Pie'
+		]
 	}
 }

bramble-android/proguard-rules.txt

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

bramble-android/src/main/AndroidManifest.xml

@@ -11,6 +11,8 @@
 	<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, eventBus, backoffFactory);
+				androidExecutor, appContext, random, backoffFactory);
 		DuplexPluginFactory tor = new TorPluginFactory(ioExecutor, appContext,
 				locationUtils, reporter, eventBus, torSocketFactory,
 				backoffFactory);
 		DuplexPluginFactory lan = new AndroidLanTcpPluginFactory(ioExecutor,
 				backoffFactory, appContext);
-		Collection<DuplexPluginFactory> duplex =
+		final 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

@@ -11,21 +11,17 @@ 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;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginException;
-import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.AbstractBluetoothPlugin;
-import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.plugin.event.DisableBluetoothEvent;
-import org.briarproject.bramble.api.plugin.event.EnableBluetoothEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.bramble.util.AndroidUtils;
@@ -33,14 +29,23 @@ import org.briarproject.bramble.util.StringUtils;
 
 import java.io.Closeable;
 import java.io.IOException;
+import java.io.InputStream;
 import java.security.SecureRandom;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.UUID;
 import java.util.concurrent.Callable;
+import java.util.concurrent.CompletionService;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Executor;
+import java.util.concurrent.ExecutorCompletionService;
+import java.util.concurrent.Future;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
 
@@ -55,6 +60,8 @@ import static android.bluetooth.BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERA
 import static android.bluetooth.BluetoothAdapter.SCAN_MODE_NONE;
 import static android.bluetooth.BluetoothAdapter.STATE_OFF;
 import static android.bluetooth.BluetoothAdapter.STATE_ON;
+import static android.bluetooth.BluetoothDevice.EXTRA_DEVICE;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_BLUETOOTH;
@@ -67,21 +74,20 @@ import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
-class DroidtoothPlugin implements DuplexPlugin, EventListener {
+class DroidtoothPlugin<C, S>
+		extends AbstractBluetoothPlugin<C, S>{
 
 	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;
 	private final Context appContext;
-	private final SecureRandom secureRandom;
-	private final Backoff backoff;
-	private final DuplexPluginCallback callback;
-	private final int maxLatency;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
-	private volatile boolean running = false;
 	private volatile boolean wasEnabledByUs = false;
 	private volatile BluetoothStateReceiver receiver = null;
 	private volatile BluetoothServerSocket socket = null;
@@ -92,29 +98,15 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 	DroidtoothPlugin(Executor ioExecutor, AndroidExecutor androidExecutor,
 			Context appContext, SecureRandom secureRandom, Backoff backoff,
 			DuplexPluginCallback callback, int maxLatency) {
-		this.ioExecutor = ioExecutor;
+
+		super(ioExecutor, secureRandom, backoff, maxLatency, callback);
 		this.androidExecutor = androidExecutor;
 		this.appContext = appContext;
-		this.secureRandom = secureRandom;
-		this.backoff = backoff;
-		this.callback = callback;
-		this.maxLatency = maxLatency;
 	}
 
 	@Override
-	public TransportId getId() {
+	protected void close(S ss) throws IOException {
-		return ID;
+		((BluetoothServerSocket)ss).close();
-	}
-
-	@Override
-	public int getMaxLatency() {
-		return maxLatency;
-	}
-
-	@Override
-	public int getMaxIdleTime() {
-		// Bluetooth detects dead connections so we don't need keepalives
-		return Integer.MAX_VALUE;
 	}
 
 	@Override
@@ -124,7 +116,12 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		// with a message queue, so submit it to the AndroidExecutor
 		try {
 			adapter = androidExecutor.runOnBackgroundThread(
-					BluetoothAdapter::getDefaultAdapter).get();
+					new Callable<BluetoothAdapter>() {
+						@Override
+						public BluetoothAdapter call() throws Exception {
+							return BluetoothAdapter.getDefaultAdapter();
+						}
+					}).get();
 		} catch (InterruptedException e) {
 			Thread.currentThread().interrupt();
 			LOG.warning("Interrupted while getting BluetoothAdapter");
@@ -149,7 +146,9 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		} else {
 			// Enable Bluetooth if settings allow
 			if (callback.getSettings().getBoolean(PREF_BT_ENABLE, false)) {
-				enableAdapter();
+				wasEnabledByUs = true;
+				if (adapter.enable()) LOG.info("Enabling Bluetooth");
+				else LOG.info("Could not enable Bluetooth");
 			} else {
 				LOG.info("Not enabling Bluetooth");
 			}
@@ -157,62 +156,43 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 	}
 
 	private void bind() {
-		ioExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			if (!isRunning()) return;
+			@Override
-			String address = AndroidUtils.getBluetoothAddress(appContext,
+			public void run() {
-					adapter);
+				if (!isRunning()) return;
-			if (LOG.isLoggable(INFO))
+				String address = AndroidUtils.getBluetoothAddress(appContext,
-				LOG.info("Local address " + scrubMacAddress(address));
+						adapter);
-			if (!StringUtils.isNullOrEmpty(address)) {
+				if (LOG.isLoggable(INFO))
-				// Advertise the Bluetooth address to contacts
+					LOG.info("Local address " + scrubMacAddress(address));
-				TransportProperties p = new TransportProperties();
+				if (!StringUtils.isNullOrEmpty(address)) {
-				p.put(PROP_ADDRESS, address);
+					// Advertise the Bluetooth address to contacts
-				callback.mergeLocalProperties(p);
+					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", UUID.fromString(getUuid()));
+				} catch (IOException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
+					return;
+				}
+				if (!isRunning()) {
+					tryToClose((S)ss);
+					return;
+				}
+				LOG.info("Socket bound");
+				socket = ss;
+				backoff.reset();
+				callback.transportEnabled();
+				acceptContactConnections();
 			}
-			// 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();
 		});
 	}
 
-	private UUID getUuid() {
-		String uuid = callback.getLocalProperties().get(PROP_UUID);
-		if (uuid == null) {
-			byte[] random = new byte[UUID_BYTES];
-			secureRandom.nextBytes(random);
-			uuid = UUID.nameUUIDFromBytes(random).toString();
-			TransportProperties p = new TransportProperties();
-			p.put(PROP_UUID, uuid);
-			callback.mergeLocalProperties(p);
-		}
-		return UUID.fromString(uuid);
-	}
-
-	private void tryToClose(@Nullable BluetoothServerSocket ss) {
-		try {
-			if (ss != null) ss.close();
-		} catch (IOException e) {
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-		} finally {
-			callback.transportDisabled();
-		}
-	}
-
 	private void acceptContactConnections() {
 		while (isRunning()) {
 			BluetoothSocket s;
@@ -236,27 +216,13 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		return new DroidtoothTransportConnection(this, s);
 	}
 
-	private void enableAdapter() {
-		if (adapter != null && !adapter.isEnabled()) {
-			if (adapter.enable()) {
-				LOG.info("Enabling Bluetooth");
-				wasEnabledByUs = true;
-			} else {
-				LOG.info("Could not enable Bluetooth");
-			}
-		}
-	}
-
 	@Override
 	public void stop() {
-		running = false;
+		this.running = false;
 		if (receiver != null) appContext.unregisterReceiver(receiver);
-		tryToClose(socket);
+		tryToClose((S)socket);
-		disableAdapter();
+		// Disable Bluetooth if we enabled it and it's still enabled
-	}
+		if (wasEnabledByUs && adapter.isEnabled()) {
-
-	private void disableAdapter() {
-		if (adapter != null && adapter.isEnabled() && wasEnabledByUs) {
 			if (adapter.disable()) LOG.info("Disabling Bluetooth");
 			else LOG.info("Could not disable Bluetooth");
 		}
@@ -267,39 +233,20 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		return running && adapter != null && adapter.isEnabled();
 	}
 
-	@Override
+	protected Runnable returnPollRunnable(final String address, final String uuid,
-	public boolean shouldPoll() {
+			final ContactId c) {
-		return true;
+		return new Runnable() {
-	}
+			@Override
-
+			public void run() {
-	@Override
-	public int getPollingInterval() {
-		return backoff.getPollingInterval();
-	}
-
-	@Override
-	public void poll(Collection<ContactId> connected) {
-		if (!isRunning()) return;
-		backoff.increment();
-		// Try to connect to known devices in parallel
-		Map<ContactId, TransportProperties> remote =
-				callback.getRemoteProperties();
-		for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {
-			ContactId c = e.getKey();
-			if (connected.contains(c)) continue;
-			String address = e.getValue().get(PROP_ADDRESS);
-			if (StringUtils.isNullOrEmpty(address)) continue;
-			String uuid = e.getValue().get(PROP_UUID);
-			if (StringUtils.isNullOrEmpty(uuid)) continue;
-			ioExecutor.execute(() -> {
 				if (!running) return;
 				BluetoothSocket s = connect(address, uuid);
 				if (s != null) {
 					backoff.reset();
 					callback.outgoingConnectionCreated(c, wrapSocket(s));
 				}
-			});
+			}
-		}
+
+		};
 	}
 
 	@Nullable
@@ -335,35 +282,95 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 				LOG.info("Failed to connect to " + scrubMacAddress(address)
 						+ ": " + e);
 			}
-			tryToClose(s);
+			tryToClose((S)s);
 			return null;
 		}
 	}
 
-	private void tryToClose(@Nullable Closeable c) {
+
+	public DuplexTransportConnection connectToAddress(String address, String uuid) {
+		BluetoothSocket s = connect(address, uuid);
+		return s == null ? null : wrapSocket(s);
+	}
+
+
+	@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 {
-			if (c != null) c.close();
+			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((S)ss);
+			closeSockets(futures, chosen);
 		}
 	}
 
-	@Override
+	private void closeSockets(final List<Future<BluetoothSocket>> futures,
-	public DuplexTransportConnection createConnection(ContactId c) {
+			@Nullable final BluetoothSocket chosen) {
-		if (!isRunning()) return null;
+		ioExecutor.execute(new Runnable() {
-		TransportProperties p = callback.getRemoteProperties(c);
+			@Override
-		String address = p.get(PROP_ADDRESS);
+			public void run() {
-		if (StringUtils.isNullOrEmpty(address)) return null;
+				for (Future<BluetoothSocket> f : futures) {
-		String uuid = p.get(PROP_UUID);
+					try {
-		if (StringUtils.isNullOrEmpty(uuid)) return null;
+						if (f.cancel(true)) {
-		BluetoothSocket s = connect(address, uuid);
+							LOG.info("Cancelled task");
-		if (s == null) return null;
+						} else {
-		return new DroidtoothTransportConnection(this, s);
+							BluetoothSocket s = f.get();
-	}
+							if (s != null && s != chosen) {
-
+								LOG.info("Closing unwanted socket");
-	@Override
+								s.close();
-	public boolean supportsKeyAgreement() {
+							}
-		return true;
+						}
+					} catch (InterruptedException e) {
+						LOG.info("Interrupted while closing sockets");
+						return;
+					} catch (ExecutionException | IOException e) {
+						if (LOG.isLoggable(INFO)) LOG.info(e.toString());
+					}
+				}
+			}
+		});
 	}
 
 	@Override
@@ -375,7 +382,7 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		// No truncation necessary because COMMIT_LENGTH = 16
 		UUID uuid = UUID.nameUUIDFromBytes(commitment);
 		if (LOG.isLoggable(INFO)) LOG.info("Key agreement UUID " + uuid);
-		// Bind a server socket for receiving key agreement connections
+		// Bind a server socket for receiving invitation connections
 		BluetoothServerSocket ss;
 		try {
 			ss = adapter.listenUsingInsecureRfcommWithServiceRecord(
@@ -390,48 +397,6 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		return new BluetoothKeyAgreementListener(descriptor, ss);
 	}
 
-	@Override
-	public DuplexTransportConnection createKeyAgreementConnection(
-			byte[] commitment, BdfList descriptor, long timeout) {
-		if (!isRunning()) return null;
-		String address;
-		try {
-			address = parseAddress(descriptor);
-		} catch (FormatException e) {
-			LOG.info("Invalid address in key agreement descriptor");
-			return null;
-		}
-		// No truncation necessary because COMMIT_LENGTH = 16
-		UUID uuid = UUID.nameUUIDFromBytes(commitment);
-		if (LOG.isLoggable(INFO))
-			LOG.info("Connecting to key agreement UUID " + uuid);
-		BluetoothSocket s = connect(address, uuid.toString());
-		if (s == null) return null;
-		return new DroidtoothTransportConnection(this, s);
-	}
-
-	private String parseAddress(BdfList descriptor) throws FormatException {
-		byte[] mac = descriptor.getRaw(1);
-		if (mac.length != 6) throw new FormatException();
-		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 {
 
@@ -443,7 +408,7 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 				bind();
 			} else if (state == STATE_OFF) {
 				LOG.info("Bluetooth disabled");
-				tryToClose(socket);
+				tryToClose((S)socket);
 			}
 			int scanMode = intent.getIntExtra(EXTRA_SCAN_MODE, 0);
 			if (scanMode == SCAN_MODE_NONE) {
@@ -456,6 +421,115 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 		}
 	}
 
+	private class DiscoveryTask implements Callable<BluetoothSocket> {
+
+		private final String uuid;
+
+		private DiscoveryTask(String uuid) {
+			this.uuid = uuid;
+		}
+
+		@Override
+		public BluetoothSocket call() throws Exception {
+			// Repeat discovery until we connect or get interrupted
+			while (true) {
+				// Discover nearby devices
+				LOG.info("Discovering nearby devices");
+				List<String> addresses = discoverDevices();
+				if (addresses.isEmpty()) {
+					LOG.info("No devices discovered");
+					continue;
+				}
+				// Connect to any device with the right UUID
+				for (String address : addresses) {
+					BluetoothSocket s = connect(address, uuid);
+					if (s != null) {
+						LOG.info("Outgoing connection");
+						return s;
+					}
+				}
+			}
+		}
+
+		private List<String> discoverDevices() throws InterruptedException {
+			IntentFilter filter = new IntentFilter();
+			filter.addAction(FOUND);
+			filter.addAction(DISCOVERY_FINISHED);
+			DiscoveryReceiver disco = new DiscoveryReceiver();
+			appContext.registerReceiver(disco, filter);
+			LOG.info("Starting discovery");
+			adapter.startDiscovery();
+			return disco.waitForAddresses();
+		}
+	}
+
+	private static class DiscoveryReceiver extends BroadcastReceiver {
+
+		private final CountDownLatch finished = new CountDownLatch(1);
+		private final List<String> addresses = new CopyOnWriteArrayList<>();
+
+		@Override
+		public void onReceive(Context ctx, Intent intent) {
+			String action = intent.getAction();
+			if (action.equals(DISCOVERY_FINISHED)) {
+				LOG.info("Discovery finished");
+				ctx.unregisterReceiver(this);
+				finished.countDown();
+			} else if (action.equals(FOUND)) {
+				BluetoothDevice d = intent.getParcelableExtra(EXTRA_DEVICE);
+				if (LOG.isLoggable(INFO)) {
+					LOG.info("Discovered device: " +
+							scrubMacAddress(d.getAddress()));
+				}
+				addresses.add(d.getAddress());
+			}
+		}
+
+		private List<String> waitForAddresses() throws InterruptedException {
+			finished.await();
+			List<String> shuffled = new ArrayList<>(addresses);
+			Collections.shuffle(shuffled);
+			return shuffled;
+		}
+	}
+
+	private static class ListeningTask implements Callable<BluetoothSocket> {
+
+		private final BluetoothServerSocket serverSocket;
+
+		private ListeningTask(BluetoothServerSocket serverSocket) {
+			this.serverSocket = serverSocket;
+		}
+
+		@Override
+		public BluetoothSocket call() throws IOException {
+			BluetoothSocket s = serverSocket.accept();
+			LOG.info("Incoming connection");
+			return s;
+		}
+	}
+
+	private static class ReadableTask implements Callable<BluetoothSocket> {
+
+		private final Callable<BluetoothSocket> connectionTask;
+
+		private ReadableTask(Callable<BluetoothSocket> connectionTask) {
+			this.connectionTask = connectionTask;
+		}
+
+		@Override
+		public BluetoothSocket call() throws Exception {
+			BluetoothSocket s = connectionTask.call();
+			InputStream in = s.getInputStream();
+			while (in.available() == 0) {
+				LOG.info("Waiting for data");
+				Thread.sleep(1000);
+			}
+			LOG.info("Data available");
+			return s;
+		}
+	}
+
 	private class BluetoothKeyAgreementListener extends KeyAgreementListener {
 
 		private final BluetoothServerSocket ss;
@@ -468,13 +542,16 @@ class DroidtoothPlugin implements DuplexPlugin, EventListener {
 
 		@Override
 		public Callable<KeyAgreementConnection> listen() {
-			return () -> {
+			return new Callable<KeyAgreementConnection>() {
-				BluetoothSocket s = ss.accept();
+				@Override
-				if (LOG.isLoggable(INFO))
+				public KeyAgreementConnection call() throws IOException {
-					LOG.info(ID.getString() + ": Incoming connection");
+					BluetoothSocket s = ss.accept();
-				return new KeyAgreementConnection(
+					if (LOG.isLoggable(INFO))
-						new DroidtoothTransportConnection(
+						LOG.info(ID.getString() + ": Incoming connection");
-								DroidtoothPlugin.this, s), ID);
+					return new KeyAgreementConnection(
+							new DroidtoothTransportConnection(
+									DroidtoothPlugin.this, s), ID);
+				}
 			};
 		}
 

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

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

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

@@ -17,6 +17,7 @@ import net.freehaven.tor.control.EventHandler;
 import net.freehaven.tor.control.TorControlConnection;
 
 import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
@@ -55,7 +56,6 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Scanner;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.Executor;
@@ -85,13 +85,13 @@ import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_NEVER;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_WIFI;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_PORT;
-import static org.briarproject.bramble.api.plugin.TorConstants.PROP_ONION;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubOnion;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
+	private static final String PROP_ONION = "onion";
 	private static final String[] EVENTS = {
 			"CIRC", "ORCONN", "HS_DESC", "NOTICE", "WARN", "ERR"
 	};
@@ -149,8 +149,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		cookieFile = new File(torDirectory, ".tor/control_auth_cookie");
 		Object o = appContext.getSystemService(POWER_SERVICE);
 		PowerManager pm = (PowerManager) o;
-		// This tag will prevent Huawei's powermanager from killing us.
+		wakeLock = pm.newWakeLock(PARTIAL_WAKE_LOCK, "TorPlugin");
-		wakeLock = pm.newWakeLock(PARTIAL_WAKE_LOCK, "LocationManagerService");
 		wakeLock.setReferenceCounted(false);
 	}
 
@@ -370,45 +369,57 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void sendDevReports() {
-		ioExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			// TODO: Trigger this with a TransportEnabledEvent
+			@Override
-			File reportDir = AndroidUtils.getReportDir(appContext);
+			public void run() {
-			reporter.sendReports(reportDir);
+				// TODO: Trigger this with a TransportEnabledEvent
+				File reportDir = AndroidUtils.getReportDir(appContext);
+				reporter.sendReports(reportDir);
+			}
 		});
 	}
 
 	private void bind() {
-		ioExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			// If there's already a port number stored in config, reuse it
+			@Override
-			String portString = callback.getSettings().get(PREF_TOR_PORT);
+			public void run() {
-			int port;
+				// If there's already a port number stored in config, reuse it
-			if (StringUtils.isNullOrEmpty(portString)) port = 0;
+				String portString = callback.getSettings().get(PREF_TOR_PORT);
-			else port = Integer.parseInt(portString);
+				int port;
-			// Bind a server socket to receive connections from Tor
+				if (StringUtils.isNullOrEmpty(portString)) port = 0;
-			ServerSocket ss = null;
+				else port = Integer.parseInt(portString);
-			try {
+				// Bind a server socket to receive connections from Tor
-				ss = new ServerSocket();
+				ServerSocket ss = null;
-				ss.bind(new InetSocketAddress("127.0.0.1", port));
+				try {
-			} catch (IOException e) {
+					ss = new ServerSocket();
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+					ss.bind(new InetSocketAddress("127.0.0.1", port));
-				tryToClose(ss);
+				} catch (IOException e) {
-				return;
+					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);
 			}
-			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);
 		});
 	}
 
@@ -528,21 +539,20 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	public void poll(Collection<ContactId> connected) {
 		if (!isRunning()) return;
 		backoff.increment();
-		Map<ContactId, TransportProperties> remote =
+		// TODO: Pass properties to connectAndCallBack()
-				callback.getRemoteProperties();
+		for (ContactId c : callback.getRemoteProperties().keySet())
-		for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {
+			if (!connected.contains(c)) connectAndCallBack(c);
-			ContactId c = e.getKey();
-			if (!connected.contains(c)) connectAndCallBack(c, e.getValue());
-		}
 	}
 
-	private void connectAndCallBack(ContactId c, TransportProperties p) {
+	private void connectAndCallBack(final ContactId c) {
-		ioExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			if (!isRunning()) return;
+			@Override
-			DuplexTransportConnection d = createConnection(p);
+			public void run() {
-			if (d != null) {
+				DuplexTransportConnection d = createConnection(c);
-				backoff.reset();
+				if (d != null) {
-				callback.outgoingConnectionCreated(c, d);
+					backoff.reset();
+					callback.outgoingConnectionCreated(c, d);
+				}
 			}
 		});
 	}
@@ -550,11 +560,8 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public DuplexTransportConnection createConnection(ContactId c) {
 		if (!isRunning()) return null;
-		return createConnection(callback.getRemoteProperties(c));
+		TransportProperties p = callback.getRemoteProperties().get(c);
-	}
+		if (p == null) return null;
-
-	@Nullable
-	private DuplexTransportConnection createConnection(TransportProperties p) {
 		String onion = p.get(PROP_ONION);
 		if (StringUtils.isNullOrEmpty(onion)) return null;
 		if (!ONION.matcher(onion).matches()) {
@@ -582,6 +589,17 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		}
 	}
 
+	@Override
+	public boolean supportsInvitations() {
+		return false;
+	}
+
+	@Override
+	public DuplexTransportConnection createInvitationConnection(PseudoRandom r,
+			long timeout, boolean alice) {
+		throw new UnsupportedOperationException();
+	}
+
 	@Override
 	public boolean supportsKeyAgreement() {
 		return false;
@@ -675,43 +693,48 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	}
 
 	private void updateConnectionStatus() {
-		ioExecutor.execute(() -> {
+		ioExecutor.execute(new Runnable() {
-			if (!running) return;
+			@Override
+			public void run() {
+				if (!running) return;
 
-			Object o = appContext.getSystemService(CONNECTIVITY_SERVICE);
+				Object o = appContext.getSystemService(CONNECTIVITY_SERVICE);
-			ConnectivityManager cm = (ConnectivityManager) o;
+				ConnectivityManager cm = (ConnectivityManager) o;
-			NetworkInfo net = cm.getActiveNetworkInfo();
+				NetworkInfo net = cm.getActiveNetworkInfo();
-			boolean online = net != null && net.isConnected();
+				boolean online = net != null && net.isConnected();
-			boolean wifi = online && net.getType() == TYPE_WIFI;
+				boolean wifi = online && net.getType() == TYPE_WIFI;
-			String country = locationUtils.getCurrentCountry();
+				String country = locationUtils.getCurrentCountry();
-			boolean blocked = TorNetworkMetadata.isTorProbablyBlocked(
+				boolean blocked = TorNetworkMetadata.isTorProbablyBlocked(
-					country);
+						country);
-			Settings s = callback.getSettings();
+				Settings s = callback.getSettings();
-			int network = s.getInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_ALWAYS);
+				int network = s.getInt(PREF_TOR_NETWORK,
+						PREF_TOR_NETWORK_ALWAYS);
 
-			if (LOG.isLoggable(INFO)) {
+				if (LOG.isLoggable(INFO)) {
-				LOG.info("Online: " + online + ", wifi: " + wifi);
+					LOG.info("Online: " + online + ", wifi: " + wifi);
-				if ("".equals(country)) LOG.info("Country code unknown");
+					if ("".equals(country)) LOG.info("Country code unknown");
-				else LOG.info("Country code: " + country);
+					else LOG.info("Country code: " + country);
-			}
+				}
-
+
-			try {
+				try {
-				if (!online) {
+					if (!online) {
-					LOG.info("Disabling network, device is offline");
+						LOG.info("Disabling network, device is offline");
-					enableNetwork(false);
+						enableNetwork(false);
-				} else if (blocked) {
+					} else if (blocked) {
-					LOG.info("Disabling network, country is blocked");
+						LOG.info("Disabling network, country is blocked");
-					enableNetwork(false);
+						enableNetwork(false);
-				} else if (network == PREF_TOR_NETWORK_NEVER
+					} else if (network == PREF_TOR_NETWORK_NEVER
-						|| (network == PREF_TOR_NETWORK_WIFI && !wifi)) {
+							|| (network == PREF_TOR_NETWORK_WIFI && !wifi)) {
-					LOG.info("Disabling network due to data setting");
+						LOG.info("Disabling network due to data setting");
-					enableNetwork(false);
+						enableNetwork(false);
-				} else {
+					} else {
-					LOG.info("Enabling network");
+						LOG.info("Enabling network");
-					enableNetwork(true);
+						enableNetwork(true);
+					}
+				} catch (IOException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
 				}
-			} 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

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

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

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

bramble-api/build.gradle

@@ -1,39 +1,30 @@
-apply plugin: 'java-library'
+apply plugin: 'java'
-sourceCompatibility = 1.8
+sourceCompatibility = 1.6
-targetCompatibility = 1.8
+targetCompatibility = 1.6
 
 apply plugin: 'witness'
 
 dependencies {
-	implementation "com.google.dagger:dagger:2.0.2"
+	compile "com.google.dagger:dagger:2.0.2"
-	implementation 'com.google.code.findbugs:jsr305:3.0.2'
+	compile 'com.google.dagger:dagger-compiler:2.0.2'
+	compile 'com.google.code.findbugs:jsr305:3.0.1'
 
-	testImplementation 'junit:junit:4.12'
+	testCompile 'junit:junit:4.12'
-	testImplementation "org.jmock:jmock:2.8.2"
+	testCompile "org.jmock:jmock:2.8.1"
-	testImplementation "org.jmock:jmock-junit4:2.8.2"
+	testCompile "org.jmock:jmock-junit4:2.8.1"
-	testImplementation "org.jmock:jmock-legacy:2.8.2"
+	testCompile "org.jmock:jmock-legacy:2.8.1"
-	testImplementation "org.hamcrest:hamcrest-library:1.3"
+	testCompile "org.hamcrest:hamcrest-library:1.3"
-	testImplementation "org.hamcrest:hamcrest-core:1.3"
+	testCompile "org.hamcrest:hamcrest-core:1.3"
 }
 
 dependencyVerification {
 	verify = [
-			'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+			'com.google.dagger:dagger:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
-			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+			'com.google.dagger:dagger-compiler:b74bc9de063dd4c6400b232231f2ef5056145b8fbecbf5382012007dd1c071b3',
-			'com.google.dagger:dagger:2.0.2:dagger-2.0.2.jar:84c0282ed8be73a29e0475d639da030b55dee72369e58dd35ae7d4fe6243dcf9',
+			'com.google.code.findbugs:jsr305:c885ce34249682bc0236b4a7d56efcc12048e6135a5baf7a9cde8ad8cda13fcd',
-			'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
+			'javax.inject:javax.inject:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
-			'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
+			'com.google.dagger:dagger-producers:99ec15e8a0507ba569e7655bc1165ee5e5ca5aa914b3c8f7e2c2458f724edd6b',
-			'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
+			'com.google.guava:guava:d664fbfc03d2e5ce9cab2a44fb01f1d0bf9dfebeccc1a473b1f9ea31f79f6f99',
-			'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',
 	]
 }
 
@@ -48,8 +39,3 @@ 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/Bytes.java

@@ -1,7 +1,6 @@
 package org.briarproject.bramble.api;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.util.StringUtils;
 
 import java.util.Arrays;
 import java.util.Comparator;
@@ -54,12 +53,6 @@ public class Bytes implements Comparable<Bytes> {
 		return aBytes.length - bBytes.length;
 	}
 
-	@Override
-	public String toString() {
-		return getClass().getSimpleName() +
-				"(" + StringUtils.toHexString(getBytes()) + ")";
-	}
-
 	public static class BytesComparator implements Comparator<Bytes> {
 
 		@Override

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.emptyList());
+		this(dictionary, Collections.<MessageId>emptyList());
 	}
 
 	public BdfDictionary getDictionary() {

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

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

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

@@ -12,32 +12,6 @@ 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

@@ -1,5 +1,8 @@
 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;
 
@@ -7,6 +10,8 @@ public interface CryptoComponent {
 
 	SecretKey generateSecretKey();
 
+	PseudoRandom getPseudoRandom(int seed1, int seed2);
+
 	SecureRandom getSecureRandom();
 
 	KeyPair generateAgreementKeyPair();
@@ -17,98 +22,164 @@ public interface CryptoComponent {
 
 	KeyParser getSignatureKeyParser();
 
-	KeyPair generateEdKeyPair();
-
-	KeyParser getEdKeyParser();
-
 	KeyParser getMessageKeyParser();
 
+	/** Generates a random invitation code. */
+	int generateBTInvitationCode();
+
 	/**
-	 * Derives another secret key from the given secret key.
+	 * Derives a confirmation code from the given master secret.
-	 *
+	 * @param alice whether the code is for use by Alice or Bob.
-	 * @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
 	 */
-	SecretKey deriveKey(String label, SecretKey k, byte[]... inputs);
+	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.
+	 *
+	 * @param publicKey the public key
+	 * @return the commitment to the provided public key.
+	 */
+	byte[] deriveKeyCommitment(byte[] publicKey);
 
 	/**
 	 * Derives a common shared secret from two public keys and one of the
 	 * corresponding private keys.
+	 * <p/>
+	 * Part of BQP.
 	 *
-	 * @param label a namespaced label indicating the purpose of this shared
+	 * @param theirPublicKey the ephemeral public key of the remote party
-	 * secret, to prevent it from being repurposed or colliding with a shared
+	 * @param ourKeyPair our ephemeral keypair
-	 * secret derived for another purpose
+	 * @param alice true if ourKeyPair belongs to Alice
-	 * @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(String label, PublicKey theirPublicKey,
+	SecretKey deriveSharedSecret(byte[] theirPublicKey, KeyPair ourKeyPair,
-			KeyPair ourKeyPair, byte[]... inputs)
+			boolean alice) throws GeneralSecurityException;
-			throws GeneralSecurityException;
 
 	/**
-	 * Signs the given byte[] with the given ECDSA private key.
+	 * Derives the content of a confirmation record.
+	 * <p/>
+	 * Part of BQP.
 	 *
-	 * @param label a namespaced label indicating the purpose of this
+	 * @param sharedSecret the common shared secret
-	 * signature, to prevent it from being repurposed or colliding with a
+	 * @param theirPayload the commit payload from the remote party
-	 * signature created for another purpose
+	 * @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, 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
 	 */
 	byte[] sign(String label, byte[] toSign, byte[] privateKey)
 			throws GeneralSecurityException;
 
 	/**
-	 * Signs the given byte[] with the given Ed25519 private key.
+	 * Verifies that the given signature is valid for the signedData
+	 * and the given publicKey.
 	 *
-	 * @param label A label specific to this signature
+	 * @param label A label that was 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 namespaced label indicating the purpose of this hash, to
+	 * @param label A label specific to this hash to ensure that hashes
-	 * prevent it from being repurposed or colliding with a hash created for
+	 *              calculated for distinct purposes don't collide.
-	 * 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(String label, SecretKey macKey, byte[]... inputs);
+	byte[] mac(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

@@ -1,50 +0,0 @@
-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

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

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

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

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

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

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

@@ -1,32 +0,0 @@
-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

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

@@ -3,17 +3,15 @@ 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;
 
-@NotThreadSafe
+public class BdfList extends Vector<Object> {
-public class BdfList extends ArrayList<Object> {
 
 	/**
 	 * Factory method for constructing lists inline.

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

@@ -122,9 +122,8 @@ public interface DatabaseComponent {
 			throws DbException;
 
 	/**
-	 * Deletes the message with the given ID. Unlike
+	 * Deletes the message with the given ID. The message ID and any other
-	 * {@link #removeMessage(Transaction, MessageId)}, the message ID and any
+	 * associated data are not deleted.
-	 * other associated data are not deleted.
 	 */
 	void deleteMessage(Transaction txn, MessageId m) throws DbException;
 
@@ -453,11 +452,6 @@ 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.TreeMap;
+import java.util.Hashtable;
 
-import javax.annotation.concurrent.NotThreadSafe;
+import javax.annotation.concurrent.ThreadSafe;
 
-@NotThreadSafe
+@ThreadSafe
-public class Metadata extends TreeMap<String, byte[]> {
+public class Metadata extends Hashtable<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<>();
+		if (events == null) events = new ArrayList<Event>();
 		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

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

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

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

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

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

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

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

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

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

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

@@ -5,7 +5,7 @@ public interface KeyAgreementConstants {
 	/**
 	 * The current version of the BQP protocol.
 	 */
-	byte PROTOCOL_VERSION = 3;
+	byte PROTOCOL_VERSION = 2;
 
 	/**
 	 * The length of the record header in bytes.
@@ -22,10 +22,7 @@ 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.
@@ -36,16 +33,4 @@ 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

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

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

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

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

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

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

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

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

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

@@ -0,0 +1,190 @@
+package org.briarproject.bramble.api.plugin.duplex;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.data.BdfList;
+import org.briarproject.bramble.api.plugin.Backoff;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.properties.TransportProperties;
+import org.briarproject.bramble.util.StringUtils;
+
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_UUID;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.UUID_BYTES;
+
+import java.io.IOException;
+import java.security.SecureRandom;
+import java.util.Collection;
+import java.util.Map;
+import java.util.UUID;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+
+/**
+ * Created by Santiago Torres-Arias on 1/10/17.
+ */
+
+public abstract class AbstractBluetoothPlugin<C, S> implements DuplexPlugin {
+
+	private static final Logger LOG =
+			Logger.getLogger("Halp");
+
+	protected final Executor ioExecutor;
+	protected final SecureRandom secureRandom;
+	protected final Backoff backoff;
+	protected final int maxLatency;
+	protected final DuplexPluginCallback callback;
+	protected final S ss = null;
+
+	protected volatile boolean running = false;
+
+	protected Runnable pollRunnable = null;
+
+	public AbstractBluetoothPlugin(Executor ioExecutor,
+			SecureRandom secureRandom,
+			Backoff backoff, int maxLatency,
+			DuplexPluginCallback callback) {
+		this.ioExecutor = ioExecutor;
+		this.secureRandom = secureRandom;
+		this.backoff = backoff;
+		this.maxLatency = maxLatency;
+		this.callback = callback;
+	}
+
+	@Override
+	public boolean supportsInvitations() {
+		return true;
+	}
+
+	@Override
+	public boolean supportsKeyAgreement() {
+		return true;
+	}
+
+	@Override
+	public boolean isRunning() {
+		return running;
+	}
+
+	@Override
+	public boolean shouldPoll() {
+		return true;
+	}
+
+	@Override
+	public int getPollingInterval() {
+		return backoff.getPollingInterval();
+	}
+
+	protected String getUuid() {
+		String uuid = callback.getLocalProperties().get(PROP_UUID);
+		if (uuid == null) {
+			byte[] random = new byte[UUID_BYTES];
+			secureRandom.nextBytes(random);
+			uuid = UUID.nameUUIDFromBytes(random).toString();
+			TransportProperties p = new TransportProperties();
+			p.put(PROP_UUID, uuid);
+			callback.mergeLocalProperties(p);
+		}
+		return uuid;
+	}
+
+	@Override
+	public TransportId getId() {
+		return ID;
+	}
+
+	@Override
+	public int getMaxLatency() {
+		return maxLatency;
+	}
+
+	@Override
+	public int getMaxIdleTime() {
+		// Bluetooth detects dead connections so we don't need keepalives
+		return Integer.MAX_VALUE;
+	}
+
+	protected String parseAddress(BdfList descriptor) throws FormatException {
+		byte[] mac = descriptor.getRaw(1);
+		if (mac.length != 6) throw new FormatException();
+		return StringUtils.macToString(mac);
+	}
+
+	protected void tryToClose(@Nullable S ss) {
+		try {
+			if (ss != null) close(ss);
+		} catch (IOException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		} finally {
+			callback.transportDisabled();
+		}
+	}
+
+	protected abstract void close(S ss) throws IOException;
+
+	public void stop() {
+		running = false;
+		tryToClose(ss);
+	}
+
+	@Override
+	public void poll(final Collection<ContactId> connected) {
+		if (!running) return;
+		backoff.increment();
+		// Try to connect to known devices in parallel
+		Map<ContactId, TransportProperties> remote =
+				callback.getRemoteProperties();
+		for (Map.Entry<ContactId, TransportProperties> e : remote.entrySet()) {
+			final ContactId c = e.getKey();
+			if (connected.contains(c)) continue;
+			final String address = e.getValue().get(PROP_ADDRESS);
+			if (StringUtils.isNullOrEmpty(address)) continue;
+			final String uuid = e.getValue().get(PROP_UUID);
+			if (StringUtils.isNullOrEmpty(uuid)) continue;
+			ioExecutor.execute(returnPollRunnable(address,uuid, c));
+		}
+	}
+
+	protected abstract Runnable returnPollRunnable(String address, String uuid,
+			ContactId c);
+
+	@Override
+	public DuplexTransportConnection createConnection(ContactId c) {
+		if (!isRunning()) return null;
+		TransportProperties p = callback.getRemoteProperties().get(c);
+		if (p == null) return null;
+		String address = p.get(PROP_ADDRESS);
+		if (StringUtils.isNullOrEmpty(address)) return null;
+		String uuid = p.get(PROP_UUID);
+		if (StringUtils.isNullOrEmpty(uuid)) return null;
+		return connectToAddress(address, uuid);
+	}
+
+	protected abstract DuplexTransportConnection connectToAddress(String address, String uuid);
+
+	@Override
+	public DuplexTransportConnection createKeyAgreementConnection(
+			byte[] commitment, BdfList descriptor, long timeout) {
+		if (!isRunning()) return null;
+		String address;
+		try {
+			address = parseAddress(descriptor);
+		} catch (FormatException e) {
+			LOG.info("Invalid address in key agreement descriptor");
+			return null;
+		}
+		// No truncation necessary because COMMIT_LENGTH = 16
+		String uuid = UUID.nameUUIDFromBytes(commitment).toString();
+		if (LOG.isLoggable(INFO))
+			LOG.info("Connecting to key agreement UUID " + uuid);
+		return connectToAddress(address, uuid);
+	}
+
+}

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

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

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

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

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

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

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

@@ -17,11 +17,6 @@ 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.
@@ -38,7 +33,7 @@ public interface TransportPropertyManager {
 	/**
 	 * Returns the local transport properties for all transports.
 	 * <br/>
-	 * TODO: Transaction can be read-only when code is simplified
+	 * Read-Only
 	 */
 	Map<TransportId, TransportProperties> getLocalProperties(Transaction txn)
 			throws DbException;
@@ -54,13 +49,6 @@ public interface TransportPropertyManager {
 	Map<ContactId, TransportProperties> getRemoteProperties(TransportId t)
 			throws DbException;
 
-	/**
-	 * Returns the remote transport properties for the given contact and
-	 * transport.
-	 */
-	TransportProperties getRemoteProperties(ContactId c, TransportId t)
-			throws DbException;
-
 	/**
 	 * Merges the given properties with the existing local properties for the
 	 * given transport.

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

@@ -36,8 +36,4 @@ 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, client version and descriptor.
+	 * Creates a group with the given client ID and descriptor.
 	 */
-	Group createGroup(ClientId c, int clientVersion, byte[] descriptor);
+	Group createGroup(ClientId c, 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.emptyList());
+		this(metadata, Collections.<MessageId>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 a contact
+	 * Creates an {@link InputStream InputStream} for reading from an
-	 * exchangestream.
+	 * invitation stream.
 	 */
-	InputStream createContactExchangeStreamReader(InputStream in,
+	InputStream createInvitationStreamReader(InputStream in,
 			SecretKey headerKey);
 }

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

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

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

@@ -4,11 +4,6 @@ import org.briarproject.bramble.api.crypto.SecretKey;
 
 public interface TransportConstants {
 
-	/**
-	 * The current version of the transport protocol.
-	 */
-	int PROTOCOL_VERSION = 4;
-
 	/**
 	 * The length of the pseudo-random tag in bytes.
 	 */
@@ -19,22 +14,21 @@ public interface TransportConstants {
 	 */
 	int STREAM_HEADER_NONCE_LENGTH = 24;
 
+	/**
+	 * The length of the stream header initialisation vector (IV) in bytes.
+	 */
+	int STREAM_HEADER_IV_LENGTH = STREAM_HEADER_NONCE_LENGTH - 8;
+
 	/**
 	 * The length of the message authentication code (MAC) in bytes.
 	 */
 	int MAC_LENGTH = 16;
 
-	/**
-	 * The length of the stream header plaintext in bytes. The stream header
-	 * contains the protocol version, stream number and frame key.
-	 */
-	int STREAM_HEADER_PLAINTEXT_LENGTH = 2 + 8 + SecretKey.LENGTH;
-
 	/**
 	 * The length of the stream header in bytes.
 	 */
-	int STREAM_HEADER_LENGTH = STREAM_HEADER_NONCE_LENGTH
+	int STREAM_HEADER_LENGTH = STREAM_HEADER_IV_LENGTH + SecretKey.LENGTH
-			+ STREAM_HEADER_PLAINTEXT_LENGTH + MAC_LENGTH;
+			+ MAC_LENGTH;
 
 	/**
 	 * The length of the frame nonce in bytes.
@@ -80,32 +74,4 @@ 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

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

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

@@ -19,7 +19,7 @@ public class PrivacyUtils {
 
 	@Nullable
 	public static String scrubMacAddress(@Nullable String address) {
-		if (address == null || address.length() == 0) return null;
+		if (address == null) return null;
 		// this is a fake address we need to know about
 		if (address.equals("02:00:00:00:00:00")) return address;
 		// keep first and last octet of MAC address

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

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

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

@@ -3,7 +3,8 @@ 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

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

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

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

bramble-core/build.gradle

@@ -1,60 +1,26 @@
-apply plugin: 'java-library'
+plugins {
-sourceCompatibility = 1.8
+	id "java"
-targetCompatibility = 1.8
+	id "net.ltgt.apt" version "0.9"
+	id "idea"
+}
+sourceCompatibility = 1.6
+targetCompatibility = 1.6
 
-apply plugin: 'net.ltgt.apt'
-apply plugin: 'idea'
 apply plugin: 'witness'
 
 dependencies {
-	implementation project(path: ':bramble-api', configuration: 'default')
+	compile project(':bramble-api')
-	implementation 'com.madgag.spongycastle:core:1.58.0.0'
+	compile fileTree(dir: 'libs', include: '*.jar')
-	implementation 'com.h2database:h2:1.4.192' // The last version that supports Java 1.6
+	compile 'com.madgag.spongycastle:core:1.54.0.0'
-	implementation 'org.bitlet:weupnp:0.1.4'
+	compile 'com.h2database:h2:1.4.190'
-	implementation 'net.i2p.crypto:eddsa:0.2.0'
 
-	apt 'com.google.dagger:dagger-compiler:2.0.2'
+	testCompile project(path: ':bramble-api', configuration: 'testOutput')
-
-	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 = [
-			'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+			'com.madgag.spongycastle:core:1e7fa4b19ccccd1011364ab838d0b4702470c178bbbdd94c5c90b2d4d749ea1e',
-			'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+			'com.h2database:h2:23ba495a07bbbb3bd6c3084d10a96dad7a23741b8b6d64b213459a784195a98c'
-			'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',
 	]
 }
 
@@ -69,8 +35,3 @@ 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

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

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

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

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

@@ -201,7 +201,8 @@ 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<>(raw.size());
+		Map<MessageId, BdfDictionary> parsed =
+				new HashMap<MessageId, BdfDictionary>(raw.size());
 		for (Entry<MessageId, Metadata> e : raw.entrySet())
 			parsed.put(e.getKey(), metadataParser.parse(e.getValue()));
 		return parsed;
@@ -228,7 +229,8 @@ 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<>(raw.size());
+		Map<MessageId, BdfDictionary> parsed =
+				new HashMap<MessageId, BdfDictionary>(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

@@ -32,25 +32,23 @@ class ContactGroupFactoryImpl implements ContactGroupFactory {
 	}
 
 	@Override
-	public Group createLocalGroup(ClientId clientId, int clientVersion) {
+	public Group createLocalGroup(ClientId clientId) {
-		return groupFactory.createGroup(clientId, clientVersion,
+		return groupFactory.createGroup(clientId, LOCAL_GROUP_DESCRIPTOR);
-				LOCAL_GROUP_DESCRIPTOR);
 	}
 
 	@Override
-	public Group createContactGroup(ClientId clientId, int clientVersion,
+	public Group createContactGroup(ClientId clientId, Contact contact) {
-			Contact contact) {
 		AuthorId local = contact.getLocalAuthorId();
 		AuthorId remote = contact.getAuthor().getId();
 		byte[] descriptor = createGroupDescriptor(local, remote);
-		return groupFactory.createGroup(clientId, clientVersion, descriptor);
+		return groupFactory.createGroup(clientId, descriptor);
 	}
 
 	@Override
-	public Group createContactGroup(ClientId clientId, int clientVersion,
+	public Group createContactGroup(ClientId clientId, AuthorId authorId1,
-			AuthorId authorId1, AuthorId authorId2) {
+			AuthorId authorId2) {
 		byte[] descriptor = createGroupDescriptor(authorId1, authorId2);
-		return groupFactory.createGroup(clientId, clientVersion, descriptor);
+		return groupFactory.createGroup(clientId, 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
-	ContactExchangeTaskImpl(DatabaseComponent db,
+	public ContactExchangeTaskImpl(DatabaseComponent db,
 			AuthorFactory authorFactory, BdfReaderFactory bdfReaderFactory,
 			BdfWriterFactory bdfWriterFactory, Clock clock,
 			ConnectionManager connectionManager, ContactManager contactManager,
@@ -141,27 +141,23 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		}
 
 		// Derive the header keys for the transport streams
-		SecretKey aliceHeaderKey = crypto.deriveKey(ALICE_KEY_LABEL,
+		SecretKey aliceHeaderKey = crypto.deriveHeaderKey(masterSecret, true);
-				masterSecret, new byte[] {PROTOCOL_VERSION});
+		SecretKey bobHeaderKey = crypto.deriveHeaderKey(masterSecret, false);
-		SecretKey bobHeaderKey = crypto.deriveKey(BOB_KEY_LABEL, masterSecret,
-				new byte[] {PROTOCOL_VERSION});
 
 		// Create the readers
 		InputStream streamReader =
-				streamReaderFactory.createContactExchangeStreamReader(in,
+				streamReaderFactory.createInvitationStreamReader(in,
 						alice ? bobHeaderKey : aliceHeaderKey);
 		BdfReader r = bdfReaderFactory.createReader(streamReader);
 		// Create the writers
 		OutputStream streamWriter =
-				streamWriterFactory.createContactExchangeStreamWriter(out,
+				streamWriterFactory.createInvitationStreamWriter(out,
 						alice ? aliceHeaderKey : bobHeaderKey);
 		BdfWriter w = bdfWriterFactory.createWriter(streamWriter);
 
 		// Derive the nonces to be signed
-		byte[] aliceNonce = crypto.mac(ALICE_NONCE_LABEL, masterSecret,
+		byte[] aliceNonce = crypto.deriveSignatureNonce(masterSecret, true);
-				new byte[] {PROTOCOL_VERSION});
+		byte[] bobNonce = crypto.deriveSignatureNonce(masterSecret, false);
-		byte[] bobNonce = crypto.mac(BOB_NONCE_LABEL, masterSecret,
-				new byte[] {PROTOCOL_VERSION});
 
 		// Exchange pseudonyms, signed nonces, and timestamps
 		long localTimestamp = clock.currentTimeMillis();
@@ -188,7 +184,12 @@ 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 | IOException e) {
+		} catch (GeneralSecurityException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			listener.contactExchangeFailed();
+			tryToClose(conn, true);
+			return;
+		} catch (IOException e) {
 			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 			listener.contactExchangeFailed();
 			tryToClose(conn, true);
@@ -200,8 +201,8 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 
 		try {
 			// Add the contact
-			ContactId contactId = addContact(remoteAuthor, timestamp,
+			ContactId contactId = addContact(remoteAuthor, masterSecret,
-					remoteProperties);
+					timestamp, alice, remoteProperties);
 			// Reuse the connection as a transport connection
 			connectionManager.manageOutgoingConnection(contactId, transportId,
 					conn);
@@ -275,7 +276,8 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 
 	private Map<TransportId, TransportProperties> receiveTransportProperties(
 			BdfReader r) throws IOException {
-		Map<TransportId, TransportProperties> remote = new HashMap<>();
+		Map<TransportId, TransportProperties> remote =
+				new HashMap<TransportId, TransportProperties>();
 		r.readListStart();
 		while (!r.hasListEnd()) {
 			r.readListStart();
@@ -298,15 +300,15 @@ class ContactExchangeTaskImpl extends Thread implements ContactExchangeTask {
 		return remote;
 	}
 
-	private ContactId addContact(Author remoteAuthor, long timestamp,
+	private ContactId addContact(Author remoteAuthor, SecretKey master,
+			long timestamp, boolean alice,
 			Map<TransportId, TransportProperties> remoteProperties)
 			throws DbException {
 		ContactId contactId;
 		Transaction txn = db.startTransaction(false);
 		try {
 			contactId = contactManager.addContact(txn, remoteAuthor,
-					localAuthor.getId(), masterSecret, timestamp, alice,
+					localAuthor.getId(), master, timestamp, alice, true, true);
-					true, true);
 			transportPropertyManager.addRemoteProperties(txn, contactId,
 					remoteProperties);
 			db.commitTransaction(txn);
@@ -316,7 +318,8 @@ 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<>();
+		addHooks = new CopyOnWriteArrayList<AddContactHook>();
-		removeHooks = new CopyOnWriteArrayList<>();
+		removeHooks = new CopyOnWriteArrayList<RemoveContactHook>();
 	}
 
 	@Override
@@ -125,7 +125,7 @@ class ContactManagerImpl implements ContactManager {
 		} finally {
 			db.endTransaction(txn);
 		}
-		List<Contact> active = new ArrayList<>(contacts.size());
+		List<Contact> active = new ArrayList<Contact>(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

@@ -1,16 +1,17 @@
 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;
@@ -26,6 +27,7 @@ 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;
@@ -39,8 +41,13 @@ 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_32_BYTES;
+import static org.briarproject.bramble.util.ByteUtils.INT_64_BYTES;
+import static org.briarproject.bramble.util.ByteUtils.MAX_32_BIT_UNSIGNED;
 
 class CryptoComponentImpl implements CryptoComponent {
 
@@ -49,19 +56,52 @@ 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) {
@@ -95,9 +135,6 @@ 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
@@ -132,6 +169,14 @@ class CryptoComponentImpl implements CryptoComponent {
 		return new SecretKey(b);
 	}
 
+	@Override
+	public PseudoRandom getPseudoRandom(int seed1, int seed2) {
+		byte[] seed = new byte[INT_32_BYTES * 2];
+		ByteUtils.writeUint32(seed1, seed, 0);
+		ByteUtils.writeUint32(seed2, seed, INT_32_BYTES);
+		return new PseudoRandomImpl(seed);
+	}
+
 	@Override
 	public SecureRandom getSecureRandom() {
 		return secureRandom;
@@ -156,21 +201,6 @@ 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 =
@@ -219,63 +249,204 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public SecretKey deriveKey(String label, SecretKey k, byte[]... inputs) {
+	public int generateBTInvitationCode() {
-		byte[] mac = mac(label, k, inputs);
+		int codeBytes = (CODE_BITS + 7) / 8;
-		if (mac.length != SecretKey.LENGTH) throw new IllegalStateException();
+		byte[] random = new byte[codeBytes];
-		return new SecretKey(mac);
+		secureRandom.nextBytes(random);
+		return ByteUtils.readUint(random, CODE_BITS);
 	}
 
 	@Override
-	public SecretKey deriveSharedSecret(String label, PublicKey theirPublicKey,
+	public int deriveBTConfirmationCode(SecretKey master, boolean alice) {
-			KeyPair ourKeyPair, byte[]... inputs)
+		byte[] b = macKdf(master, alice ? BT_A_CONFIRM : BT_B_CONFIRM);
-			throws GeneralSecurityException {
+		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 {
 		PrivateKey ourPriv = ourKeyPair.getPrivate();
-		byte[][] hashInputs = new byte[inputs.length + 1][];
+		PublicKey theirPub = agreementKeyParser.parsePublicKey(theirPublicKey);
-		hashInputs[0] = performRawKeyAgreement(ourPriv, theirPublicKey);
+		byte[] raw = performRawKeyAgreement(ourPriv, theirPub);
-		System.arraycopy(inputs, 0, hashInputs, 1, inputs.length);
+		byte[] alicePub, bobPub;
-		byte[] hash = hash(label, hashInputs);
+		if (alice) {
-		if (hash.length != SecretKey.LENGTH) throw new IllegalStateException();
+			alicePub = ourKeyPair.getPublic().getEncoded();
-		return new SecretKey(hash);
+			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, long streamNumber) {
+		if (tag.length < TAG_LENGTH) 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 stream number as a 64-bit integer
+		byte[] input = new byte[INT_64_BYTES];
+		ByteUtils.writeUint64(streamNumber, input, 0);
+		prf.update(input, 0, input.length);
+		byte[] mac = new byte[macLength];
+		prf.doFinal(mac, 0);
+		// The output is the first TAG_LENGTH bytes of the MAC
+		System.arraycopy(mac, 0, tag, 0, TAG_LENGTH);
 	}
 
 	@Override
 	public byte[] sign(String label, byte[] toSign, byte[] privateKey)
 			throws GeneralSecurityException {
-		return sign(new SignatureImpl(secureRandom), signatureKeyParser, label,
+		Signature signature = new SignatureImpl(secureRandom);
-				toSign, privateKey);
+		KeyParser keyParser = getSignatureKeyParser();
-	}
-
-	@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);
-		sig.initSign(key);
+		signature.initSign(key);
-		updateSignature(sig, label, toSign);
+		updateSignature(signature, label, toSign);
-		return sig.sign();
+		return signature.sign();
 	}
 
 	@Override
 	public boolean verify(String label, byte[] signedData, byte[] publicKey,
 			byte[] signature) throws GeneralSecurityException {
-		return verify(new SignatureImpl(secureRandom), signatureKeyParser,
+		Signature sig = new SignatureImpl(secureRandom);
-				label, signedData, publicKey, signature);
+		KeyParser keyParser = getSignatureKeyParser();
-	}
-
-	@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);
@@ -283,7 +454,7 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	private void updateSignature(Signature signature, String label,
-			byte[] toSign) throws GeneralSecurityException {
+			byte[] toSign) {
 		byte[] labelBytes = StringUtils.toUtf8(label);
 		byte[] length = new byte[INT_32_BYTES];
 		ByteUtils.writeUint32(labelBytes.length, length, 0);
@@ -313,13 +484,14 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public byte[] mac(String label, SecretKey macKey, byte[]... inputs) {
+	public int getHashLength() {
-		byte[] labelBytes = StringUtils.toUtf8(label);
+		return HASH_SIZE;
+	}
+
+	@Override
+	public byte[] mac(SecretKey macKey, byte[]... inputs) {
 		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);
@@ -411,6 +583,30 @@ 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);
@@ -424,8 +620,8 @@ class CryptoComponentImpl implements CryptoComponent {
 
 	// Package access for testing
 	int chooseIterationCount(int targetMillis) {
-		List<Long> quickSamples = new ArrayList<>(PBKDF_SAMPLES);
+		List<Long> quickSamples = new ArrayList<Long>(PBKDF_SAMPLES);
-		List<Long> slowSamples = new ArrayList<>(PBKDF_SAMPLES);
+		List<Long> slowSamples = new ArrayList<Long>(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

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

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

@@ -1,26 +0,0 @@
-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

@@ -1,18 +0,0 @@
-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

@@ -1,18 +0,0 @@
-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

@@ -1,83 +0,0 @@
-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

@@ -1,56 +0,0 @@
-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<>();
+		HashSet<Character> unique = new HashSet<Character>();
 		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/PseudoRandomImpl.java

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

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

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

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

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

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

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

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

@@ -4,7 +4,6 @@ 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;
 
@@ -14,8 +13,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 import javax.inject.Provider;
 
-import static org.briarproject.bramble.api.transport.TransportConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_IV_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_NONCE_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
 
 @Immutable
@@ -23,15 +21,12 @@ 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;
 	}
 
@@ -41,23 +36,22 @@ class StreamEncrypterFactoryImpl implements StreamEncrypterFactory {
 		AuthenticatedCipher cipher = cipherProvider.get();
 		long streamNumber = ctx.getStreamNumber();
 		byte[] tag = new byte[TAG_LENGTH];
-		transportCrypto.encodeTag(tag, ctx.getTagKey(), PROTOCOL_VERSION,
+		crypto.encodeTag(tag, ctx.getTagKey(), streamNumber);
-				streamNumber);
+		byte[] streamHeaderIv = new byte[STREAM_HEADER_IV_LENGTH];
-		byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
+		crypto.getSecureRandom().nextBytes(streamHeaderIv);
-		crypto.getSecureRandom().nextBytes(streamHeaderNonce);
 		SecretKey frameKey = crypto.generateSecretKey();
 		return new StreamEncrypterImpl(out, cipher, streamNumber, tag,
-				streamHeaderNonce, ctx.getHeaderKey(), frameKey);
+				streamHeaderIv, ctx.getHeaderKey(), frameKey);
 	}
 
 	@Override
-	public StreamEncrypter createContactExchangeStreamDecrypter(
+	public StreamEncrypter createInvitationStreamEncrypter(OutputStream out,
-			OutputStream out, SecretKey headerKey) {
+			SecretKey headerKey) {
 		AuthenticatedCipher cipher = cipherProvider.get();
-		byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
+		byte[] streamHeaderIv = new byte[STREAM_HEADER_IV_LENGTH];
-		crypto.getSecureRandom().nextBytes(streamHeaderNonce);
+		crypto.getSecureRandom().nextBytes(streamHeaderIv);
 		SecretKey frameKey = crypto.generateSecretKey();
-		return new StreamEncrypterImpl(out, cipher, 0, null, streamHeaderNonce,
+		return new StreamEncrypterImpl(out, cipher, 0, null, streamHeaderIv,
 				headerKey, frameKey);
 	}
 }

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

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

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

@@ -1,135 +0,0 @@
-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/crypto/XSalsa20Poly1305AuthenticatedCipher.java

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

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

@@ -90,6 +90,8 @@ 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) {
@@ -101,20 +103,26 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 
 	@Override
 	public boolean open() throws DbException {
-		boolean reopened = db.open();
+		Runnable shutdownHook = new Runnable() {
-		shutdown.addShutdownHook(() -> {
+			@Override
-			try {
+			public void run() {
-				close();
+				try {
-			} catch (DbException e) {
+					close();
-				if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+				} catch (DbException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
+				}
 			}
-		});
+		};
+		boolean reopened = db.open();
+		shutdownHandle = shutdown.addShutdownHook(shutdownHook);
 		return reopened;
 	}
 
 	@Override
 	public void close() throws DbException {
 		if (closed.getAndSet(true)) return;
+		shutdown.removeShutdownHook(shutdownHandle);
 		db.close();
 	}
 
@@ -133,7 +141,11 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		}
 		try {
 			return new Transaction(db.startTransaction(), readOnly);
-		} catch (DbException | RuntimeException e) {
+		} catch (DbException e) {
+			if (readOnly) lock.readLock().unlock();
+			else lock.writeLock().unlock();
+			throw e;
+		} catch (RuntimeException e) {
 			if (readOnly) lock.readLock().unlock();
 			else lock.writeLock().unlock();
 			throw e;
@@ -319,7 +331,7 @@ 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<>(ids.size());
+		List<byte[]> messages = new ArrayList<byte[]>(ids.size());
 		for (MessageId m : ids) {
 			messages.add(db.getRawMessage(txn, m));
 			db.updateExpiryTime(txn, c, m, maxLatency);
@@ -369,7 +381,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			throw new NoSuchContactException();
 		Collection<MessageId> ids = db.getRequestedMessagesToSend(txn, c,
 				maxLength);
-		List<byte[]> messages = new ArrayList<>(ids.size());
+		List<byte[]> messages = new ArrayList<byte[]>(ids.size());
 		for (MessageId m : ids) {
 			messages.add(db.getRawMessage(txn, m));
 			db.updateExpiryTime(txn, c, m, maxLatency);
@@ -649,7 +661,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
-		Collection<MessageId> acked = new ArrayList<>();
+		Collection<MessageId> acked = new ArrayList<MessageId>();
 		for (MessageId m : a.getMessageIds()) {
 			if (db.containsVisibleMessage(txn, c, m)) {
 				db.raiseSeenFlag(txn, c, m);
@@ -758,16 +770,6 @@ 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 {
@@ -884,7 +886,8 @@ 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<>();
+		Map<ContactId, TransportKeys> filtered =
+				new HashMap<ContactId, TransportKeys>();
 		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<>();
+		BlockingQueue<Runnable> queue = new LinkedBlockingQueue<Runnable>();
 		// 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<>(db, Connection.class, eventBus,
+		return new DatabaseComponentImpl<Connection>(db, Connection.class,
-				shutdown);
+				eventBus, shutdown);
 	}
 }

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

@@ -22,23 +22,21 @@ 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 STRING_TYPE = "VARCHAR";
+	private static final String SECRET_TYPE = "BINARY(32)";
 
 	private final DatabaseConfig config;
 	private final String url;
 
 	@Inject
 	H2Database(DatabaseConfig config, Clock clock) {
-		super(HASH_TYPE, SECRET_TYPE, BINARY_TYPE, COUNTER_TYPE, STRING_TYPE,
+		super(HASH_TYPE, BINARY_TYPE, COUNTER_TYPE, SECRET_TYPE, clock);
-				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";
+				+ ";WRITE_DELAY=0;DB_CLOSE_ON_EXIT=false";
 	}
 
 	@Override

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

@@ -1,99 +0,0 @@
-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 = 31;
+	private static final int SCHEMA_VERSION = 30;
-	private static final int MIN_SCHEMA_VERSION = 31;
+	private static final int MIN_SCHEMA_VERSION = 30;
 
 	private static final String CREATE_SETTINGS =
 			"CREATE TABLE settings"
-					+ " (namespace _STRING NOT NULL,"
+					+ " (namespace VARCHAR NOT NULL,"
-					+ " settingKey _STRING NOT NULL,"
+					+ " key VARCHAR NOT NULL,"
-					+ " value _STRING NOT NULL,"
+					+ " value VARCHAR NOT NULL,"
-					+ " PRIMARY KEY (namespace, settingKey))";
+					+ " PRIMARY KEY (namespace, key))";
 
 	private static final String CREATE_LOCAL_AUTHORS =
 			"CREATE TABLE localAuthors"
-					+ " (authorId _HASH NOT NULL,"
+					+ " (authorId HASH NOT NULL,"
-					+ " name _STRING NOT NULL,"
+					+ " name VARCHAR NOT NULL,"
-					+ " publicKey _BINARY NOT NULL,"
+					+ " publicKey BINARY NOT NULL,"
-					+ " privateKey _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,"
+					+ " (contactId COUNTER,"
-					+ " authorId _HASH NOT NULL,"
+					+ " authorId HASH NOT NULL,"
-					+ " name _STRING NOT NULL,"
+					+ " name VARCHAR NOT NULL,"
-					+ " publicKey _BINARY NOT NULL,"
+					+ " publicKey BINARY NOT NULL,"
-					+ " localAuthorId _HASH 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,"
+					+ " (groupId HASH NOT NULL,"
-					+ " clientId _STRING NOT NULL,"
+					+ " clientId VARCHAR NOT NULL,"
-					+ " descriptor _BINARY NOT NULL,"
+					+ " descriptor BINARY NOT NULL,"
 					+ " PRIMARY KEY (groupId))";
 
 	private static final String CREATE_GROUP_METADATA =
 			"CREATE TABLE groupMetadata"
-					+ " (groupId _HASH NOT NULL,"
+					+ " (groupId HASH NOT NULL,"
-					+ " metaKey _STRING NOT NULL,"
+					+ " key VARCHAR NOT NULL,"
-					+ " value _BINARY NOT NULL,"
+					+ " value BINARY NOT NULL,"
-					+ " PRIMARY KEY (groupId, metaKey),"
+					+ " PRIMARY KEY (groupId, key),"
 					+ " 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,"
+					+ " (messageId HASH NOT NULL,"
-					+ " groupId _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,"
+					+ " (messageId HASH NOT NULL,"
-					+ " metaKey _STRING NOT NULL,"
+					+ " key VARCHAR NOT NULL,"
-					+ " value _BINARY NOT NULL,"
+					+ " value BINARY NOT NULL,"
-					+ " PRIMARY KEY (messageId, metaKey),"
+					+ " PRIMARY KEY (messageId, key),"
 					+ " FOREIGN KEY (messageId)"
 					+ " REFERENCES messages (messageId)"
 					+ " ON DELETE CASCADE)";
 
 	private static final String CREATE_MESSAGE_DEPENDENCIES =
 			"CREATE TABLE messageDependencies"
-					+ " (groupId _HASH NOT NULL,"
+					+ " (groupId HASH NOT NULL,"
-					+ " messageId _HASH NOT NULL,"
+					+ " messageId HASH NOT NULL,"
-					+ " dependencyId _HASH NOT NULL," // Not a foreign key
+					+ " 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 _STRING NOT NULL,"
+					+ " (transportId VARCHAR NOT NULL,"
 					+ " maxLatency INT NOT NULL,"
 					+ " PRIMARY KEY (transportId))";
 
 	private static final String CREATE_INCOMING_KEYS =
 			"CREATE TABLE incomingKeys"
 					+ " (contactId INT NOT NULL,"
-					+ " transportId _STRING NOT NULL,"
+					+ " transportId VARCHAR NOT NULL,"
-					+ " rotationPeriod BIGINT NOT NULL,"
+					+ " period BIGINT NOT NULL,"
-					+ " tagKey _SECRET NOT NULL,"
+					+ " tagKey SECRET NOT NULL,"
-					+ " headerKey _SECRET NOT NULL,"
+					+ " headerKey SECRET NOT NULL,"
 					+ " base BIGINT NOT NULL,"
-					+ " bitmap _BINARY NOT NULL,"
+					+ " bitmap BINARY NOT NULL,"
-					+ " PRIMARY KEY (contactId, transportId, rotationPeriod),"
+					+ " PRIMARY KEY (contactId, transportId, period),"
 					+ " 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 _STRING NOT NULL,"
+					+ " transportId VARCHAR NOT NULL,"
-					+ " rotationPeriod BIGINT NOT NULL,"
+					+ " period BIGINT NOT NULL,"
-					+ " tagKey _SECRET NOT NULL,"
+					+ " tagKey SECRET NOT NULL,"
-					+ " headerKey _SECRET NOT NULL,"
+					+ " headerKey SECRET NOT NULL,"
 					+ " stream BIGINT NOT NULL,"
 					+ " PRIMARY KEY (contactId, transportId),"
 					+ " FOREIGN KEY (contactId)"
@@ -232,40 +232,15 @@ 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, secretType, binaryType;
+	private final String hashType, binaryType, counterType, secretType;
-	private final String counterType, stringType;
 	private final Clock clock;
 
-	// Locking: connectionsLock
+	private final LinkedList<Connection> connections =
-	private final LinkedList<Connection> connections = new LinkedList<>();
+			new LinkedList<Connection>(); // Locking: connectionsLock
 
 	private int openConnections = 0; // Locking: connectionsLock
 	private boolean closed = false; // Locking: connectionsLock
@@ -276,13 +251,12 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private final Lock connectionsLock = new ReentrantLock();
 	private final Condition connectionsChanged = connectionsLock.newCondition();
 
-	JdbcDatabase(String hashType, String secretType, String binaryType,
+	JdbcDatabase(String hashType, String binaryType, String counterType,
-			String counterType, String stringType, Clock clock) {
+			String secretType, Clock clock) {
 		this.hashType = hashType;
-		this.secretType = secretType;
 		this.binaryType = binaryType;
 		this.counterType = counterType;
-		this.stringType = stringType;
+		this.secretType = secretType;
 		this.clock = clock;
 	}
 
@@ -293,7 +267,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		} catch (ClassNotFoundException e) {
 			throw new DbException(e);
 		}
-		// Open the database and create the tables and indexes if necessary
+		// Open the database and create the tables if necessary
 		Connection txn = startTransaction();
 		try {
 			if (reopen) {
@@ -302,7 +276,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 				createTables(txn);
 				storeSchemaVersion(txn);
 			}
-			createIndexes(txn);
 			commitTransaction(txn);
 		} catch (DbException e) {
 			abortTransaction(txn);
@@ -367,35 +340,17 @@ 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("HASH", hashType);
-		s = s.replaceAll("_SECRET", secretType);
+		s = s.replaceAll("BINARY", binaryType);
-		s = s.replaceAll("_BINARY", binaryType);
+		s = s.replaceAll("COUNTER", counterType);
-		s = s.replaceAll("_COUNTER", counterType);
+		s = s.replaceAll("SECRET", secretType);
-		s = s.replaceAll("_STRING", stringType);
 		return s;
 	}
 
 	@Override
 	public Connection startTransaction() throws DbException {
-		Connection txn;
+		Connection txn = null;
 		connectionsLock.lock();
 		try {
 			if (closed) throw new DbClosedException();
@@ -503,8 +458,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		try {
 			// Create a contact row
 			String sql = "INSERT INTO contacts"
-					+ " (authorId, name, publicKey, localAuthorId,"
+					+ " (authorId, name, publicKey, localAuthorId, verified, active)"
-					+ " verified, active)"
 					+ " VALUES (?, ?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, remote.getId().getBytes());
@@ -723,7 +677,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		try {
 			// Store the incoming keys
 			String sql = "INSERT INTO incomingKeys (contactId, transportId,"
-					+ " rotationPeriod, tagKey, headerKey, base, bitmap)"
+					+ " period, tagKey, headerKey, base, bitmap)"
 					+ " VALUES (?, ?, ?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
@@ -758,8 +712,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 				if (rows != 1) throw new DbStateException();
 			ps.close();
 			// Store the outgoing keys
-			sql = "INSERT INTO outgoingKeys (contactId, transportId,"
+			sql = "INSERT INTO outgoingKeys (contactId, transportId, period,"
-					+ " rotationPeriod, tagKey, headerKey, stream)"
+					+ " tagKey, headerKey, stream)"
 					+ " VALUES (?, ?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
@@ -1039,7 +993,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " FROM contacts";
 			ps = txn.prepareStatement(sql);
 			rs = ps.executeQuery();
-			List<Contact> contacts = new ArrayList<>();
+			List<Contact> contacts = new ArrayList<Contact>();
 			while (rs.next()) {
 				ContactId contactId = new ContactId(rs.getInt(1));
 				AuthorId authorId = new AuthorId(rs.getBytes(2));
@@ -1073,7 +1027,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, local.getBytes());
 			rs = ps.executeQuery();
-			List<ContactId> ids = new ArrayList<>();
+			List<ContactId> ids = new ArrayList<ContactId>();
 			while (rs.next()) ids.add(new ContactId(rs.getInt(1)));
 			rs.close();
 			ps.close();
@@ -1098,7 +1052,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, remote.getBytes());
 			rs = ps.executeQuery();
-			List<Contact> contacts = new ArrayList<>();
+			List<Contact> contacts = new ArrayList<Contact>();
 			while (rs.next()) {
 				ContactId c = new ContactId(rs.getInt(1));
 				String name = rs.getString(2);
@@ -1154,7 +1108,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, c.getString());
 			rs = ps.executeQuery();
-			List<Group> groups = new ArrayList<>();
+			List<Group> groups = new ArrayList<Group>();
 			while (rs.next()) {
 				GroupId id = new GroupId(rs.getBytes(1));
 				byte[] descriptor = rs.getBytes(2);
@@ -1207,7 +1161,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, g.getBytes());
 			rs = ps.executeQuery();
-			List<ContactId> visible = new ArrayList<>();
+			List<ContactId> visible = new ArrayList<ContactId>();
 			while (rs.next()) visible.add(new ContactId(rs.getInt(1)));
 			rs.close();
 			ps.close();
@@ -1259,7 +1213,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " FROM localAuthors";
 			ps = txn.prepareStatement(sql);
 			rs = ps.executeQuery();
-			List<LocalAuthor> authors = new ArrayList<>();
+			List<LocalAuthor> authors = new ArrayList<LocalAuthor>();
 			while (rs.next()) {
 				AuthorId authorId = new AuthorId(rs.getBytes(1));
 				String name = rs.getString(2);
@@ -1289,7 +1243,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, g.getBytes());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			List<MessageId> ids = new ArrayList<MessageId>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1312,7 +1266,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, state.getValue());
 			ps.setBytes(2, g.getBytes());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			List<MessageId> ids = new ArrayList<MessageId>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1339,7 +1293,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " JOIN messageMetadata AS md"
 					+ " ON m.messageId = md.messageId"
 					+ " WHERE state = ? AND groupId = ?"
-					+ " AND metaKey = ? AND value = ?";
+					+ " AND key = ? AND value = ?";
 			for (Entry<String, byte[]> e : query.entrySet()) {
 				ps = txn.prepareStatement(sql);
 				ps.setInt(1, DELIVERED.getValue());
@@ -1347,7 +1301,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				ps.setString(3, e.getKey());
 				ps.setBytes(4, e.getValue());
 				rs = ps.executeQuery();
-				Set<MessageId> ids = new HashSet<>();
+				Set<MessageId> ids = new HashSet<MessageId>();
 				while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 				rs.close();
 				ps.close();
@@ -1371,7 +1325,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT m.messageId, metaKey, value"
+			String sql = "SELECT m.messageId, key, value"
 					+ " FROM messages AS m"
 					+ " JOIN messageMetadata AS md"
 					+ " ON m.messageId = md.messageId"
@@ -1381,7 +1335,7 @@ 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<>();
+			Map<MessageId, Metadata> all = new HashMap<MessageId, Metadata>();
 			Metadata metadata = null;
 			MessageId lastMessageId = null;
 			while (rs.next()) {
@@ -1410,7 +1364,8 @@ 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<>(matches.size());
+		Map<MessageId, Metadata> all = new HashMap<MessageId, Metadata>(
+				matches.size());
 		for (MessageId m : matches) all.put(m, getMessageMetadata(txn, m));
 		return all;
 	}
@@ -1421,7 +1376,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT metaKey, value FROM groupMetadata"
+			String sql = "SELECT key, value FROM groupMetadata"
 					+ " WHERE groupId = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, g.getBytes());
@@ -1444,7 +1399,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT metaKey, value FROM messageMetadata AS md"
+			String sql = "SELECT key, value FROM messageMetadata AS md"
 					+ " JOIN messages AS m"
 					+ " ON m.messageId = md.messageId"
 					+ " WHERE m.state = ? AND md.messageId = ?";
@@ -1470,7 +1425,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT metaKey, value FROM messageMetadata AS md"
+			String sql = "SELECT key, value FROM messageMetadata AS md"
 					+ " JOIN messages AS m"
 					+ " ON m.messageId = md.messageId"
 					+ " WHERE (m.state = ? OR m.state = ?)"
@@ -1508,7 +1463,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setBytes(1, g.getBytes());
 			ps.setInt(2, c.getInt());
 			rs = ps.executeQuery();
-			List<MessageStatus> statuses = new ArrayList<>();
+			List<MessageStatus> statuses = new ArrayList<MessageStatus>();
 			while (rs.next()) {
 				MessageId messageId = new MessageId(rs.getBytes(1));
 				boolean sent = rs.getBoolean(2);
@@ -1567,7 +1522,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
 			rs = ps.executeQuery();
-			Map<MessageId, State> dependencies = new HashMap<>();
+			Map<MessageId, State> dependencies = new HashMap<MessageId, State>();
 			while (rs.next()) {
 				MessageId dependency = new MessageId(rs.getBytes(1));
 				State state = State.fromValue(rs.getInt(2));
@@ -1605,7 +1560,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
 			rs = ps.executeQuery();
-			Map<MessageId, State> dependents = new HashMap<>();
+			Map<MessageId, State> dependents = new HashMap<MessageId, State>();
 			while (rs.next()) {
 				MessageId dependent = new MessageId(rs.getBytes(1));
 				State state = State.fromValue(rs.getInt(2));
@@ -1657,7 +1612,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, c.getInt());
 			ps.setInt(2, maxMessages);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			List<MessageId> ids = new ArrayList<MessageId>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1693,7 +1648,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setLong(3, now);
 			ps.setInt(4, maxMessages);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			List<MessageId> ids = new ArrayList<MessageId>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1718,7 +1673,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, c.getInt());
 			ps.setInt(2, maxMessages);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			List<MessageId> ids = new ArrayList<MessageId>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1753,7 +1708,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(2, DELIVERED.getValue());
 			ps.setLong(3, now);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			List<MessageId> ids = new ArrayList<MessageId>();
 			int total = 0;
 			while (rs.next()) {
 				int length = rs.getInt(1);
@@ -1795,7 +1750,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, state.getValue());
 			ps.setString(2, c.getString());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			List<MessageId> ids = new ArrayList<MessageId>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1825,7 +1780,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, c.getString());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			List<MessageId> ids = new ArrayList<MessageId>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
 			rs.close();
 			ps.close();
@@ -1884,7 +1839,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(2, DELIVERED.getValue());
 			ps.setLong(3, now);
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			List<MessageId> ids = new ArrayList<MessageId>();
 			int total = 0;
 			while (rs.next()) {
 				int length = rs.getInt(1);
@@ -1908,8 +1863,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT settingKey, value FROM settings"
+			String sql = "SELECT key, value FROM settings WHERE namespace = ?";
-					+ " WHERE namespace = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, namespace);
 			rs = ps.executeQuery();
@@ -1932,15 +1886,14 @@ abstract class JdbcDatabase implements Database<Connection> {
 		ResultSet rs = null;
 		try {
 			// Retrieve the incoming keys
-			String sql = "SELECT rotationPeriod, tagKey, headerKey,"
+			String sql = "SELECT period, tagKey, headerKey, base, bitmap"
-					+ " base, bitmap"
 					+ " FROM incomingKeys"
 					+ " WHERE transportId = ?"
-					+ " ORDER BY contactId, rotationPeriod";
+					+ " ORDER BY contactId, period";
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, t.getString());
 			rs = ps.executeQuery();
-			List<IncomingKeys> inKeys = new ArrayList<>();
+			List<IncomingKeys> inKeys = new ArrayList<IncomingKeys>();
 			while (rs.next()) {
 				long rotationPeriod = rs.getLong(1);
 				SecretKey tagKey = new SecretKey(rs.getBytes(2));
@@ -1953,14 +1906,15 @@ abstract class JdbcDatabase implements Database<Connection> {
 			rs.close();
 			ps.close();
 			// Retrieve the outgoing keys in the same order
-			sql = "SELECT contactId, rotationPeriod, tagKey, headerKey, stream"
+			sql = "SELECT contactId, period, tagKey, headerKey, stream"
 					+ " FROM outgoingKeys"
 					+ " WHERE transportId = ?"
-					+ " ORDER BY contactId, rotationPeriod";
+					+ " ORDER BY contactId, period";
 			ps = txn.prepareStatement(sql);
 			ps.setString(1, t.getString());
 			rs = ps.executeQuery();
-			Map<ContactId, TransportKeys> keys = new HashMap<>();
+			Map<ContactId, TransportKeys> keys =
+					new HashMap<ContactId, TransportKeys>();
 			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();
@@ -1993,8 +1947,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		try {
 			String sql = "UPDATE outgoingKeys SET stream = stream + 1"
-					+ " WHERE contactId = ? AND transportId = ?"
+					+ " WHERE contactId = ? AND transportId = ? AND period = ?";
-					+ " AND rotationPeriod = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
 			ps.setString(2, t.getString());
@@ -2079,8 +2032,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		try {
 			// Determine which keys are being removed
-			List<String> removed = new ArrayList<>();
+			List<String> removed = new ArrayList<String>();
-			Map<String, byte[]> retained = new HashMap<>();
+			Map<String, byte[]> retained = new HashMap<String, byte[]>();
 			for (Entry<String, byte[]> e : meta.entrySet()) {
 				if (e.getValue() == REMOVE) removed.add(e.getKey());
 				else retained.put(e.getKey(), e.getValue());
@@ -2088,7 +2041,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			// Delete any keys that are being removed
 			if (!removed.isEmpty()) {
 				String sql = "DELETE FROM " + tableName
-						+ " WHERE " + columnName + " = ? AND metaKey = ?";
+						+ " WHERE " + columnName + " = ? AND key = ?";
 				ps = txn.prepareStatement(sql);
 				ps.setBytes(1, id);
 				for (String key : removed) {
@@ -2107,7 +2060,7 @@ 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 metaKey = ?";
+					+ " WHERE " + columnName + " = ? AND key = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(2, id);
 			for (Entry<String, byte[]> e : retained.entrySet()) {
@@ -2124,7 +2077,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			}
 			// Insert any keys that don't already exist
 			sql = "INSERT INTO " + tableName
-					+ " (" + columnName + ", metaKey, value)"
+					+ " (" + columnName + ", key, value)"
 					+ " VALUES (?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, id);
@@ -2156,7 +2109,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		try {
 			// Update any settings that already exist
 			String sql = "UPDATE settings SET value = ?"
-					+ " WHERE namespace = ? AND settingKey = ?";
+					+ " WHERE namespace = ? AND key = ?";
 			ps = txn.prepareStatement(sql);
 			for (Entry<String, String> e : s.entrySet()) {
 				ps.setString(1, e.getValue());
@@ -2171,7 +2124,7 @@ 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, settingKey, value)"
+			sql = "INSERT INTO settings (namespace, key, value)"
 					+ " VALUES (?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			int updateIndex = 0, inserted = 0;
@@ -2535,8 +2488,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		try {
 			String sql = "UPDATE incomingKeys SET base = ?, bitmap = ?"
-					+ " WHERE contactId = ? AND transportId = ?"
+					+ " WHERE contactId = ? AND transportId = ? AND period = ?";
-					+ " 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<>();
+			new CopyOnWriteArrayList<EventListener>();
 
 	@Override
 	public void addListener(EventListener l) {

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

@@ -1,10 +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.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;
@@ -14,10 +11,6 @@ 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/>
@@ -64,7 +57,6 @@ 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;
@@ -72,13 +64,11 @@ 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;
@@ -96,7 +86,7 @@ class KeyAgreementProtocol {
 	 */
 	SecretKey perform() throws AbortException, IOException {
 		try {
-			PublicKey theirPublicKey;
+			byte[] theirPublicKey;
 			if (alice) {
 				sendKey();
 				// Alice waits here until Bob obtains her payload.
@@ -114,7 +104,7 @@ class KeyAgreementProtocol {
 				receiveConfirm(s, theirPublicKey);
 				sendConfirm(s, theirPublicKey);
 			}
-			return crypto.deriveKey(MASTER_SECRET_LABEL, s);
+			return crypto.deriveMasterSecret(s);
 		} catch (AbortException e) {
 			sendAbort(e.getCause() != null);
 			throw e;
@@ -125,41 +115,27 @@ class KeyAgreementProtocol {
 		transport.sendKey(ourKeyPair.getPublic().getEncoded());
 	}
 
-	private PublicKey receiveKey() throws AbortException {
+	private byte[] receiveKey() throws AbortException {
-		byte[] publicKeyBytes = transport.receiveKey();
+		byte[] publicKey = transport.receiveKey();
 		callbacks.initialRecordReceived();
-		KeyParser keyParser = crypto.getAgreementKeyParser();
+		byte[] expected = crypto.deriveKeyCommitment(publicKey);
-		try {
+		if (!Arrays.equals(expected, theirPayload.getCommitment()))
-			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(PublicKey theirPublicKey)
+	private SecretKey deriveSharedSecret(byte[] theirPublicKey)
 			throws AbortException {
 		try {
-			byte[] ourPublicKeyBytes = ourKeyPair.getPublic().getEncoded();
+			return crypto.deriveSharedSecret(theirPublicKey, ourKeyPair, alice);
-			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, PublicKey theirPublicKey)
+	private void sendConfirm(SecretKey s, byte[] theirPublicKey)
 			throws IOException {
-		byte[] confirm = keyAgreementCrypto.deriveConfirmationRecord(s,
+		byte[] confirm = crypto.deriveConfirmationRecord(s,
 				payloadEncoder.encode(theirPayload),
 				payloadEncoder.encode(ourPayload),
 				theirPublicKey, ourKeyPair,
@@ -167,10 +143,10 @@ class KeyAgreementProtocol {
 		transport.sendConfirm(confirm);
 	}
 
-	private void receiveConfirm(SecretKey s, PublicKey theirPublicKey)
+	private void receiveConfirm(SecretKey s, byte[] theirPublicKey)
 			throws AbortException {
 		byte[] confirm = transport.receiveConfirm();
-		byte[] expected = keyAgreementCrypto.deriveConfirmationRecord(s,
+		byte[] expected = crypto.deriveConfirmationRecord(s,
 				payloadEncoder.encode(theirPayload),
 				payloadEncoder.encode(ourPayload),
 				theirPublicKey, ourKeyPair,

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

@@ -0,0 +1,46 @@
+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);
+	}
+}