Disable image attachments for remote contacts alpha.

.gitlab-ci.yml

@@ -17,7 +17,7 @@ test:
 
   script:
     - ./gradlew --no-daemon -Djava.security.egd=file:/dev/urandom animalSnifferMain animalSnifferTest
-    - ./gradlew --no-daemon -Djava.security.egd=file:/dev/urandom check compileOfficialDebugAndroidTestSources compileScreenshotDebugAndroidTestSources
+    - ./gradlew --no-daemon -Djava.security.egd=file:/dev/urandom test
 
   after_script:
     # these file change every time but should not be cached

.idea/codeStyles/Project.xml

@@ -1,10 +1,16 @@
 <component name="ProjectCodeStyleConfiguration">
   <code_scheme name="Project" version="173">
+    <option name="RIGHT_MARGIN" value="100" />
     <AndroidXmlCodeStyleSettings>
-      <option name="ARRANGEMENT_SETTINGS_MIGRATED_TO_191" value="true" />
+      <option name="USE_CUSTOM_SETTINGS" value="true" />
     </AndroidXmlCodeStyleSettings>
     <JavaCodeStyleSettings>
       <option name="ANNOTATION_PARAMETER_WRAP" value="1" />
+      <option name="CLASS_COUNT_TO_USE_IMPORT_ON_DEMAND" value="99" />
+      <option name="NAMES_COUNT_TO_USE_IMPORT_ON_DEMAND" value="99" />
+      <option name="PACKAGES_TO_USE_IMPORT_ON_DEMAND">
+        <value />
+      </option>
       <option name="IMPORT_LAYOUT_TABLE">
         <value>
           <package name="android" withSubpackages="true" static="false" />
@@ -71,6 +77,7 @@
       </indentOptions>
     </codeStyleSettings>
     <codeStyleSettings language="XML">
+      <option name="FORCE_REARRANGE_MODE" value="1" />
       <indentOptions>
         <option name="CONTINUATION_INDENT_SIZE" value="4" />
         <option name="USE_TAB_CHARACTER" value="true" />
@@ -83,8 +90,7 @@
               <match>
                 <AND>
                   <NAME>xmlns:android</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                  <XML_NAMESPACE>Namespace:</XML_NAMESPACE>
                 </AND>
               </match>
             </rule>
@@ -94,8 +100,7 @@
               <match>
                 <AND>
                   <NAME>xmlns:.*</NAME>
-                  <XML_ATTRIBUTE />
-                  <XML_NAMESPACE>^$</XML_NAMESPACE>
+                  <XML_NAMESPACE>Namespace:</XML_NAMESPACE>
                 </AND>
               </match>
               <order>BY_NAME</order>
@@ -106,7 +111,6 @@
               <match>
                 <AND>
                   <NAME>.*:id</NAME>
-                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
                 </AND>
               </match>
@@ -117,7 +121,6 @@
               <match>
                 <AND>
                   <NAME>.*:name</NAME>
-                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
                 </AND>
               </match>
@@ -128,7 +131,6 @@
               <match>
                 <AND>
                   <NAME>name</NAME>
-                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>^$</XML_NAMESPACE>
                 </AND>
               </match>
@@ -139,7 +141,6 @@
               <match>
                 <AND>
                   <NAME>style</NAME>
-                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>^$</XML_NAMESPACE>
                 </AND>
               </match>
@@ -150,7 +151,6 @@
               <match>
                 <AND>
                   <NAME>.*</NAME>
-                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>^$</XML_NAMESPACE>
                 </AND>
               </match>
@@ -161,12 +161,64 @@
             <rule>
               <match>
                 <AND>
-                  <NAME>.*</NAME>
-                  <XML_ATTRIBUTE />
+                  <NAME>.*:layout_width</NAME>
                   <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
                 </AND>
               </match>
-              <order>ANDROID_ATTRIBUTE_ORDER</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:layout_height</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:layout_.*</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:width</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*:height</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
+            </rule>
+          </section>
+          <section>
+            <rule>
+              <match>
+                <AND>
+                  <NAME>.*</NAME>
+                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
+                </AND>
+              </match>
+              <order>BY_NAME</order>
             </rule>
           </section>
           <section>
@@ -174,7 +226,6 @@
               <match>
                 <AND>
                   <NAME>.*</NAME>
-                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>.*</XML_NAMESPACE>
                 </AND>
               </match>

bramble-android/build.gradle

@@ -5,31 +5,23 @@ apply plugin: 'witness'
 apply from: 'witness.gradle'
 
 android {
-	compileSdkVersion 29
-	buildToolsVersion '29.0.2'
+	compileSdkVersion 28
+	buildToolsVersion '28.0.3'
 
 	defaultConfig {
-		minSdkVersion 16
-		targetSdkVersion 28
-		versionCode 10207
-		versionName "1.2.7"
+		minSdkVersion 14
+		targetSdkVersion 26
+		versionCode 10107
+		versionName "1.1.7"
 		consumerProguardFiles 'proguard-rules.txt'
 
-		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
+		testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
 	}
 
 	compileOptions {
 		sourceCompatibility JavaVersion.VERSION_1_8
 		targetCompatibility JavaVersion.VERSION_1_8
 	}
-
-	lintOptions {
-		// FIXME
-		warning "LintError"
-		warning "InvalidPackage"
-		warning "MissingPermission"
-		warning "InlinedApi", "ObsoleteSdkInt", "Override", "NewApi", "UnusedAttribute"
-	}
 }
 
 configurations {
@@ -38,10 +30,10 @@ configurations {
 
 dependencies {
 	implementation project(path: ':bramble-core', configuration: 'default')
-	tor 'org.briarproject:tor-android:0.3.5.10@zip'
-	tor 'org.briarproject:obfs4proxy-android:0.0.11-2@zip'
+	tor 'org.briarproject:tor-android:0.3.5.8@zip'
+	tor 'org.briarproject:obfs4proxy-android:0.0.9@zip'
 
-	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
+	annotationProcessor 'com.google.dagger:dagger-compiler:2.22.1'
 
 	compileOnly 'javax.annotation:jsr250-api:1.0'
 
@@ -67,8 +59,6 @@ task unpackTorBinaries {
 		copy {
 			from configurations.tor.collect { zipTree(it) }
 			into torBinariesDir
-			// TODO: Remove after next Tor upgrade, which won't include non-PIE binaries
-			include 'geoip.zip', '*_pie.zip'
 		}
 	}
 	dependsOn cleanTorBinaries

bramble-android/src/main/java/org/briarproject/bramble/BrambleAndroidEagerSingletons.java

@@ -11,14 +11,4 @@ public interface BrambleAndroidEagerSingletons {
 	void inject(AndroidNetworkModule.EagerSingletons init);
 
 	void inject(ReportingModule.EagerSingletons init);
-
-	class Helper {
-
-		public static void injectEagerSingletons(
-				BrambleAndroidEagerSingletons c) {
-			c.inject(new AndroidBatteryModule.EagerSingletons());
-			c.inject(new AndroidNetworkModule.EagerSingletons());
-			c.inject(new ReportingModule.EagerSingletons());
-		}
-	}
 }

bramble-android/src/main/java/org/briarproject/bramble/BrambleAndroidModule.java

@@ -18,4 +18,10 @@ import dagger.Module;
 		SocksModule.class
 })
 public class BrambleAndroidModule {
+
+	public static void initEagerSingletons(BrambleAndroidEagerSingletons c) {
+		c.inject(new AndroidBatteryModule.EagerSingletons());
+		c.inject(new AndroidNetworkModule.EagerSingletons());
+		c.inject(new ReportingModule.EagerSingletons());
+	}
 }

bramble-android/src/main/java/org/briarproject/bramble/account/AndroidAccountManager.java

@@ -12,16 +12,13 @@ import org.briarproject.bramble.api.identity.IdentityManager;
 
 import java.io.File;
 import java.util.HashSet;
-import java.util.List;
 import java.util.Set;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
 import javax.inject.Inject;
 
 import static android.os.Build.VERSION.SDK_INT;
-import static java.util.Arrays.asList;
 import static java.util.logging.Level.INFO;
 import static org.briarproject.bramble.util.IoUtils.deleteFileOrDir;
 import static org.briarproject.bramble.util.LogUtils.logFileOrDir;
@@ -32,11 +29,7 @@ class AndroidAccountManager extends AccountManagerImpl
 	private static final Logger LOG =
 			Logger.getLogger(AndroidAccountManager.class.getName());
 
-	/**
-	 * Directories that shouldn't be deleted when deleting the user's account.
-	 */
-	private static final List<String> PROTECTED_DIR_NAMES =
-			asList("cache", "code_cache", "lib", "shared_prefs");
+	private static final String PREF_DB_KEY = "key";
 
 	protected final Context appContext;
 	private final SharedPreferences prefs;
@@ -60,6 +53,36 @@ class AndroidAccountManager extends AccountManagerImpl
 		return exists;
 	}
 
+	// Locking: stateChangeLock
+	@Override
+	@Nullable
+	protected String loadEncryptedDatabaseKey() {
+		String key = getDatabaseKeyFromPreferences();
+		if (key == null) key = super.loadEncryptedDatabaseKey();
+		else migrateDatabaseKeyToFile(key);
+		return key;
+	}
+
+	// Locking: stateChangeLock
+	@Nullable
+	private String getDatabaseKeyFromPreferences() {
+		String key = prefs.getString(PREF_DB_KEY, null);
+		if (key == null) LOG.info("No database key in preferences");
+		else LOG.info("Found database key in preferences");
+		return key;
+	}
+
+	// Locking: stateChangeLock
+	private void migrateDatabaseKeyToFile(String key) {
+		if (storeEncryptedDatabaseKey(key)) {
+			if (prefs.edit().remove(PREF_DB_KEY).commit())
+				LOG.info("Database key migrated to file");
+			else LOG.warning("Database key not removed from preferences");
+		} else {
+			LOG.warning("Database key not migrated to file");
+		}
+	}
+
 	@Override
 	public void deleteAccount() {
 		synchronized (stateChangeLock) {
@@ -82,14 +105,14 @@ class AndroidAccountManager extends AccountManagerImpl
 		return PreferenceManager.getDefaultSharedPreferences(appContext);
 	}
 
-	@GuardedBy("stateChangeLock")
+	// Locking: stateChangeLock
 	private void deleteAppData(SharedPreferences... clear) {
 		// Clear and commit shared preferences
 		for (SharedPreferences prefs : clear) {
 			if (!prefs.edit().clear().commit())
 				LOG.warning("Could not clear shared preferences");
 		}
-		// Delete files, except protected directories
+		// Delete files, except lib and shared_prefs directories
 		Set<File> files = new HashSet<>();
 		File dataDir = getDataDir();
 		@Nullable
@@ -98,12 +121,14 @@ class AndroidAccountManager extends AccountManagerImpl
 			LOG.warning("Could not list files in app data dir");
 		} else {
 			for (File file : fileArray) {
-				if (!PROTECTED_DIR_NAMES.contains(file.getName())) {
+				String name = file.getName();
+				if (!name.equals("lib") && !name.equals("shared_prefs")) {
 					files.add(file);
 				}
 			}
 		}
 		files.add(appContext.getFilesDir());
+		files.add(appContext.getCacheDir());
 		addIfNotNull(files, appContext.getExternalCacheDir());
 		if (SDK_INT >= 19) {
 			for (File file : appContext.getExternalCacheDirs()) {
@@ -115,16 +140,12 @@ class AndroidAccountManager extends AccountManagerImpl
 				addIfNotNull(files, file);
 			}
 		}
-		// Clear the cache directory but don't delete it
-		File cacheDir = appContext.getCacheDir();
-		File[] children = cacheDir.listFiles();
-		if (children != null) files.addAll(asList(children));
 		for (File file : files) {
-			if (LOG.isLoggable(INFO)) {
-				LOG.info("Deleting " + file.getAbsolutePath());
-			}
 			deleteFileOrDir(file);
 		}
+		// Recreate the cache dir as some OpenGL drivers expect it to exist
+		if (!new File(dataDir, "cache").mkdirs())
+			LOG.warning("Could not recreate cache dir");
 	}
 
 	private File getDataDir() {

bramble-android/src/main/java/org/briarproject/bramble/network/AndroidNetworkManager.java

@@ -32,7 +32,6 @@ import static android.content.Intent.ACTION_SCREEN_OFF;
 import static android.content.Intent.ACTION_SCREEN_ON;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
 import static android.net.ConnectivityManager.TYPE_WIFI;
-import static android.net.wifi.p2p.WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
 import static java.util.concurrent.TimeUnit.MINUTES;
@@ -77,9 +76,9 @@ class AndroidNetworkManager implements NetworkManager, Service {
 		filter.addAction(ACTION_SCREEN_ON);
 		filter.addAction(ACTION_SCREEN_OFF);
 		filter.addAction(WIFI_AP_STATE_CHANGED_ACTION);
-		filter.addAction(WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
 		if (SDK_INT >= 23) filter.addAction(ACTION_DEVICE_IDLE_MODE_CHANGED);
 		appContext.registerReceiver(networkStateReceiver, filter);
+
 	}
 
 	@Override
@@ -137,8 +136,7 @@ class AndroidNetworkManager implements NetworkManager, Service {
 		}
 
 		private boolean isApEvent(@Nullable String action) {
-			return WIFI_AP_STATE_CHANGED_ACTION.equals(action) ||
-					WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action);
+			return WIFI_AP_STATE_CHANGED_ACTION.equals(action);
 		}
 	}
 }

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPlugin.java

@@ -9,7 +9,6 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 
-import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
@@ -25,6 +24,7 @@ import java.io.IOException;
 import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 import java.util.UUID;
 import java.util.concurrent.BlockingQueue;
@@ -47,10 +47,7 @@ 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.ACTION_FOUND;
-import static android.bluetooth.BluetoothDevice.DEVICE_TYPE_LE;
 import static android.bluetooth.BluetoothDevice.EXTRA_DEVICE;
-import static android.os.Build.VERSION.SDK_INT;
-import static java.util.Collections.shuffle;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
@@ -77,12 +74,11 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 	private volatile BluetoothAdapter adapter = null;
 
 	AndroidBluetoothPlugin(BluetoothConnectionLimiter connectionLimiter,
-			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
-			SecureRandom secureRandom, AndroidExecutor androidExecutor,
-			Context appContext, Clock clock, Backoff backoff,
-			PluginCallback callback, int maxLatency, int maxIdleTime) {
-		super(connectionLimiter, timeoutMonitor, ioExecutor, secureRandom,
-				backoff, callback, maxLatency, maxIdleTime);
+			Executor ioExecutor, AndroidExecutor androidExecutor,
+			Context appContext, SecureRandom secureRandom, Clock clock,
+			Backoff backoff, PluginCallback callback, int maxLatency) {
+		super(connectionLimiter, ioExecutor, secureRandom, backoff, callback,
+				maxLatency);
 		this.androidExecutor = androidExecutor;
 		this.appContext = appContext;
 		this.clock = clock;
@@ -174,10 +170,9 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 		return wrapSocket(ss.accept());
 	}
 
-	private DuplexTransportConnection wrapSocket(BluetoothSocket s)
-			throws IOException {
-		return new AndroidBluetoothTransportConnection(this, connectionLimiter,
-				timeoutMonitor, s);
+	private DuplexTransportConnection wrapSocket(BluetoothSocket s) {
+		return new AndroidBluetoothTransportConnection(this,
+				connectionLimiter, s);
 	}
 
 	@Override
@@ -245,15 +240,11 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 						break;
 					} else if (ACTION_FOUND.equals(action)) {
 						BluetoothDevice d = i.getParcelableExtra(EXTRA_DEVICE);
-						// Ignore Bluetooth LE devices
-						if (SDK_INT < 18 || d.getType() != DEVICE_TYPE_LE) {
-							String address = d.getAddress();
-							if (LOG.isLoggable(INFO))
-								LOG.info("Discovered " +
-										scrubMacAddress(address));
-							if (!addresses.contains(address))
-								addresses.add(address);
-						}
+						String address = d.getAddress();
+						if (LOG.isLoggable(INFO))
+							LOG.info("Discovered " + scrubMacAddress(address));
+						if (!addresses.contains(address))
+							addresses.add(address);
 					}
 					now = clock.currentTimeMillis();
 				}
@@ -269,7 +260,7 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 			appContext.unregisterReceiver(receiver);
 		}
 		// Shuffle the addresses so we don't always try the same one first
-		shuffle(addresses);
+		Collections.shuffle(addresses);
 		return addresses;
 	}
 

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothPluginFactory.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.plugin.bluetooth;
 import android.content.Context;
 
 import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
@@ -26,7 +25,6 @@ import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
 public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 
 	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
-	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
 	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
 	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
@@ -37,20 +35,18 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 	private final SecureRandom secureRandom;
 	private final EventBus eventBus;
 	private final Clock clock;
-	private final TimeoutMonitor timeoutMonitor;
 	private final BackoffFactory backoffFactory;
 
 	public AndroidBluetoothPluginFactory(Executor ioExecutor,
 			AndroidExecutor androidExecutor, Context appContext,
 			SecureRandom secureRandom, EventBus eventBus, Clock clock,
-			TimeoutMonitor timeoutMonitor, BackoffFactory backoffFactory) {
+			BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
 		this.androidExecutor = androidExecutor;
 		this.appContext = appContext;
 		this.secureRandom = secureRandom;
 		this.eventBus = eventBus;
 		this.clock = clock;
-		this.timeoutMonitor = timeoutMonitor;
 		this.backoffFactory = backoffFactory;
 	}
 
@@ -71,9 +67,8 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		AndroidBluetoothPlugin plugin = new AndroidBluetoothPlugin(
-				connectionLimiter, timeoutMonitor, ioExecutor, secureRandom,
-				androidExecutor, appContext, clock, backoff,
-				callback, MAX_LATENCY, MAX_IDLE_TIME);
+				connectionLimiter, ioExecutor, androidExecutor, appContext,
+				secureRandom, clock, backoff, callback, MAX_LATENCY);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-android/src/main/java/org/briarproject/bramble/plugin/bluetooth/AndroidBluetoothTransportConnection.java

@@ -2,7 +2,6 @@ package org.briarproject.bramble.plugin.bluetooth;
 
 import android.bluetooth.BluetoothSocket;
 
-import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.duplex.AbstractDuplexTransportConnection;
@@ -11,33 +10,24 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 
-import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
-import static org.briarproject.bramble.util.AndroidUtils.isValidBluetoothAddress;
-
 @NotNullByDefault
 class AndroidBluetoothTransportConnection
 		extends AbstractDuplexTransportConnection {
 
-	private final BluetoothConnectionLimiter connectionLimiter;
+	private final BluetoothConnectionLimiter connectionManager;
 	private final BluetoothSocket socket;
-	private final InputStream in;
 
 	AndroidBluetoothTransportConnection(Plugin plugin,
-			BluetoothConnectionLimiter connectionLimiter,
-			TimeoutMonitor timeoutMonitor, BluetoothSocket socket)
-			throws IOException {
+			BluetoothConnectionLimiter connectionManager,
+			BluetoothSocket socket) {
 		super(plugin);
-		this.connectionLimiter = connectionLimiter;
+		this.connectionManager = connectionManager;
 		this.socket = socket;
-		in = timeoutMonitor.createTimeoutInputStream(
-				socket.getInputStream(), plugin.getMaxIdleTime() * 2);
-		String address = socket.getRemoteDevice().getAddress();
-		if (isValidBluetoothAddress(address)) remote.put(PROP_ADDRESS, address);
 	}
 
 	@Override
-	protected InputStream getInputStream() {
-		return in;
+	protected InputStream getInputStream() throws IOException {
+		return socket.getInputStream();
 	}
 
 	@Override
@@ -50,7 +40,7 @@ class AndroidBluetoothTransportConnection
 		try {
 			socket.close();
 		} finally {
-			connectionLimiter.connectionClosed(this);
+			connectionManager.connectionClosed(this);
 		}
 	}
 }

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPlugin.java

@@ -19,7 +19,7 @@ import java.io.IOException;
 import java.net.InetAddress;
 import java.net.Socket;
 import java.net.UnknownHostException;
-import java.util.List;
+import java.util.Collection;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
@@ -40,6 +40,19 @@ class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
 	private static final Logger LOG =
 			getLogger(AndroidLanTcpPlugin.class.getName());
 
+	private static final byte[] WIFI_AP_ADDRESS_BYTES =
+			{(byte) 192, (byte) 168, 43, 1};
+	private static final InetAddress WIFI_AP_ADDRESS;
+
+	static {
+		try {
+			WIFI_AP_ADDRESS = InetAddress.getByAddress(WIFI_AP_ADDRESS_BYTES);
+		} catch (UnknownHostException e) {
+			// Should only be thrown if the address has an illegal length
+			throw new AssertionError(e);
+		}
+	}
+
 	private final Executor connectionStatusExecutor;
 	private final ConnectivityManager connectivityManager;
 	@Nullable
@@ -49,9 +62,8 @@ class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
 
 	AndroidLanTcpPlugin(Executor ioExecutor, Context appContext,
 			Backoff backoff, PluginCallback callback, int maxLatency,
-			int maxIdleTime, int connectionTimeout) {
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
-				connectionTimeout);
+			int maxIdleTime) {
+		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
 		// Don't execute more than one connection status check at a time
 		connectionStatusExecutor =
 				new PoliteExecutor("AndroidLanTcpPlugin", ioExecutor, 1);
@@ -67,7 +79,6 @@ class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
 	@Override
 	public void start() {
 		if (used.getAndSet(true)) throw new IllegalStateException();
-		initialisePortProperty();
 		running = true;
 		updateConnectionStatus();
 	}
@@ -84,19 +95,16 @@ class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
 	}
 
 	@Override
-	protected List<InetAddress> getUsableLocalInetAddresses() {
+	protected Collection<InetAddress> getLocalIpAddresses() {
 		// If the device doesn't have wifi, don't open any sockets
 		if (wifiManager == null) return emptyList();
-		// If we're connected to a wifi network, return its address
+		// If we're connected to a wifi network, use that network
 		WifiInfo info = wifiManager.getConnectionInfo();
-		if (info != null && info.getIpAddress() != 0) {
+		if (info != null && info.getIpAddress() != 0)
 			return singletonList(intToInetAddress(info.getIpAddress()));
-		}
 		// If we're running an access point, return its address
-		for (InetAddress addr : getLocalInetAddresses()) {
-			if (addr.equals(WIFI_AP_ADDRESS)) return singletonList(addr);
-			if (addr.equals(WIFI_DIRECT_AP_ADDRESS)) return singletonList(addr);
-		}
+		if (super.getLocalIpAddresses().contains(WIFI_AP_ADDRESS))
+			return singletonList(WIFI_AP_ADDRESS);
 		// No suitable addresses
 		return emptyList();
 	}
@@ -136,9 +144,8 @@ class AndroidLanTcpPlugin extends LanTcpPlugin implements EventListener {
 	private void updateConnectionStatus() {
 		connectionStatusExecutor.execute(() -> {
 			if (!running) return;
-			List<InetAddress> addrs = getUsableLocalInetAddresses();
-			if (addrs.contains(WIFI_AP_ADDRESS)
-					|| addrs.contains(WIFI_DIRECT_AP_ADDRESS)) {
+			Collection<InetAddress> addrs = getLocalIpAddresses();
+			if (addrs.contains(WIFI_AP_ADDRESS)) {
 				LOG.info("Providing wifi hotspot");
 				// There's no corresponding Network object and thus no way
 				// to get a suitable socket factory, so we won't be able to

bramble-android/src/main/java/org/briarproject/bramble/plugin/tcp/AndroidLanTcpPluginFactory.java

@@ -21,11 +21,10 @@ import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 @NotNullByDefault
 public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 
-	private static final int MAX_LATENCY = 30_000; // 30 seconds
-	private static final int MAX_IDLE_TIME = 30_000; // 30 seconds
-	private static final int CONNECTION_TIMEOUT = 3_000; // 3 seconds
-	private static final int MIN_POLLING_INTERVAL = 60_000; // 1 minute
-	private static final int MAX_POLLING_INTERVAL = 600_000; // 10 mins
+	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
@@ -56,8 +55,7 @@ public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		AndroidLanTcpPlugin plugin = new AndroidLanTcpPlugin(ioExecutor,
-				appContext, backoff, callback, MAX_LATENCY, MAX_IDLE_TIME,
-				CONNECTION_TIMEOUT);
+				appContext, backoff, callback, MAX_LATENCY, MAX_IDLE_TIME);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

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

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin.tor;
 
 import android.content.Context;
+import android.os.Build;
 
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.event.EventBus;
@@ -88,15 +89,9 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 		// Check that we have a Tor binary for this architecture
 		String architecture = null;
 		for (String abi : AndroidUtils.getSupportedArchitectures()) {
-			if (abi.startsWith("x86_64")) {
-				architecture = "x86_64";
-				break;
-			} else if (abi.startsWith("x86")) {
+			if (abi.startsWith("x86")) {
 				architecture = "x86";
 				break;
-			} else if (abi.startsWith("arm64")) {
-				architecture = "arm64";
-				break;
 			} else if (abi.startsWith("armeabi")) {
 				architecture = "arm";
 				break;
@@ -106,8 +101,8 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 			LOG.info("Tor is not supported on this architecture");
 			return null;
 		}
-		// Use position-independent executable
-		architecture += "_pie";
+		// Use position-independent executable for SDK >= 16
+		if (Build.VERSION.SDK_INT >= 16) architecture += "_pie";
 
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);

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

@@ -23,7 +23,6 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static android.content.Context.WIFI_SERVICE;
-import static android.os.Build.VERSION.SDK_INT;
 import static android.provider.Settings.Secure.ANDROID_ID;
 
 @Immutable
@@ -75,7 +74,8 @@ class AndroidSecureRandomProvider extends UnixSecureRandomProvider {
 		// Silence strict mode
 		StrictMode.ThreadPolicy tp = StrictMode.allowThreadDiskWrites();
 		super.writeSeed();
-		if (SDK_INT <= 18) applyOpenSslFix();
+		if (Build.VERSION.SDK_INT >= 16 && Build.VERSION.SDK_INT <= 18)
+			applyOpenSslFix();
 		StrictMode.setThreadPolicy(tp);
 	}
 

bramble-android/src/main/java/org/briarproject/bramble/util/AndroidUtils.java

@@ -6,25 +6,15 @@ import android.content.Context;
 import android.os.Build;
 import android.provider.Settings;
 
-import org.briarproject.bramble.api.Pair;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
 import java.io.File;
-import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
-import java.lang.reflect.Method;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 
-import javax.annotation.Nullable;
-
 import static android.content.Context.MODE_PRIVATE;
 import static android.os.Build.VERSION.SDK_INT;
-import static java.util.Arrays.asList;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 
-@NotNullByDefault
 public class AndroidUtils {
 
 	// Fake Bluetooth address returned by BluetoothAdapter on API 23 and later
@@ -32,10 +22,11 @@ public class AndroidUtils {
 
 	private static final String STORED_REPORTS = "dev-reports";
 
+	@SuppressWarnings("deprecation")
 	public static Collection<String> getSupportedArchitectures() {
 		List<String> abis = new ArrayList<>();
 		if (SDK_INT >= 21) {
-			abis.addAll(asList(Build.SUPPORTED_ABIS));
+			abis.addAll(Arrays.asList(Build.SUPPORTED_ABIS));
 		} else {
 			abis.add(Build.CPU_ABI);
 			if (Build.CPU_ABI2 != null) abis.add(Build.CPU_ABI2);
@@ -45,76 +36,25 @@ public class AndroidUtils {
 
 	public static String getBluetoothAddress(Context ctx,
 			BluetoothAdapter adapter) {
-		return getBluetoothAddressAndMethod(ctx, adapter).getFirst();
-	}
-
-	public static Pair<String, String> getBluetoothAddressAndMethod(Context ctx,
-			BluetoothAdapter adapter) {
 		// Return the adapter's address if it's valid and not fake
 		@SuppressLint("HardwareIds")
 		String address = adapter.getAddress();
-		if (isValidBluetoothAddress(address)) {
-			return new Pair<>(address, "adapter");
-		}
+		if (isValidBluetoothAddress(address)) return address;
 		// Return the address from settings if it's valid and not fake
 		address = Settings.Secure.getString(ctx.getContentResolver(),
 				"bluetooth_address");
-		if (isValidBluetoothAddress(address)) {
-			return new Pair<>(address, "settings");
-		}
-		// Try to get the address via reflection
-		address = getBluetoothAddressByReflection(adapter);
-		if (isValidBluetoothAddress(address)) {
-			return new Pair<>(requireNonNull(address), "reflection");
-		}
+		if (isValidBluetoothAddress(address)) return address;
 		// Let the caller know we can't find the address
-		return new Pair<>("", "");
+		return "";
 	}
 
-	public static boolean isValidBluetoothAddress(@Nullable String address) {
+	private static boolean isValidBluetoothAddress(String address) {
 		return !StringUtils.isNullOrEmpty(address)
 				&& BluetoothAdapter.checkBluetoothAddress(address)
 				&& !address.equals(FAKE_BLUETOOTH_ADDRESS);
 	}
 
-	@Nullable
-	private static String getBluetoothAddressByReflection(
-			BluetoothAdapter adapter) {
-		try {
-			Field mServiceField =
-					adapter.getClass().getDeclaredField("mService");
-			mServiceField.setAccessible(true);
-			Object mService = mServiceField.get(adapter);
-			// mService may be null when Bluetooth is disabled
-			if (mService == null) throw new NoSuchFieldException();
-			Method getAddressMethod =
-					mService.getClass().getMethod("getAddress");
-			return (String) getAddressMethod.invoke(mService);
-		} catch (NoSuchFieldException e) {
-			return null;
-		} catch (IllegalAccessException e) {
-			return null;
-		} catch (NoSuchMethodException e) {
-			return null;
-		} catch (InvocationTargetException e) {
-			return null;
-		} catch (SecurityException e) {
-			return null;
-		}
-	}
-
 	public static File getReportDir(Context ctx) {
 		return ctx.getDir(STORED_REPORTS, MODE_PRIVATE);
 	}
-
-	/**
-	 * Returns an array of supported content types for image attachments.
-	 * GIFs can't be compressed on API < 24 so they're not supported.
-	 * <p>
-	 * TODO: Remove this restriction when large message support is added
-	 */
-	public static String[] getSupportedImageContentTypes() {
-		if (SDK_INT < 24) return new String[] {"image/jpeg", "image/png"};
-		else return new String[] {"image/jpeg", "image/png", "image/gif"};
-	}
 }

bramble-android/src/test/java/org/briarproject/bramble/account/AndroidAccountManagerTest.java

@@ -16,10 +16,13 @@ import org.junit.Test;
 
 import java.io.File;
 
+import static junit.framework.Assert.assertEquals;
 import static junit.framework.Assert.assertFalse;
 import static junit.framework.Assert.assertTrue;
 import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
+import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
 import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
+import static org.briarproject.bramble.util.StringUtils.toHexString;
 
 public class AndroidAccountManagerTest extends BrambleMockTestCase {
 
@@ -37,8 +40,11 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 	private final Application app;
 	private final ApplicationInfo applicationInfo;
 
+	private final String encryptedKeyHex = toHexString(getRandomBytes(123));
 	private final File testDir = getTestDirectory();
 	private final File keyDir = new File(testDir, "key");
+	private final File keyFile = new File(keyDir, "db.key");
+	private final File keyBackupFile = new File(keyDir, "db.key.bak");
 	private final File dbDir = new File(testDir, "db");
 
 	private AndroidAccountManager accountManager;
@@ -69,12 +75,33 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 		};
 	}
 
+	@Test
+	public void testDbKeyIsMigratedFromPreferencesToFile() {
+		context.checking(new Expectations() {{
+			oneOf(prefs).getString("key", null);
+			will(returnValue(encryptedKeyHex));
+			oneOf(prefs).edit();
+			will(returnValue(editor));
+			oneOf(editor).remove("key");
+			will(returnValue(editor));
+			oneOf(editor).commit();
+			will(returnValue(true));
+		}});
+
+		assertFalse(keyFile.exists());
+		assertFalse(keyBackupFile.exists());
+
+		assertEquals(encryptedKeyHex,
+				accountManager.loadEncryptedDatabaseKey());
+
+		assertTrue(keyFile.exists());
+		assertTrue(keyBackupFile.exists());
+	}
+
 	@Test
 	public void testDeleteAccountClearsSharedPrefsAndDeletesFiles()
 			throws Exception {
-		// Directories 'code_cache', 'lib' and 'shared_prefs' should be spared
-		File codeCacheDir = new File(testDir, "code_cache");
-		File codeCacheFile = new File(codeCacheDir, "file");
+		// Directories 'lib' and 'shared_prefs' should be spared
 		File libDir = new File(testDir, "lib");
 		File libFile = new File(libDir, "file");
 		File sharedPrefsDir = new File(testDir, "shared_prefs");
@@ -113,8 +140,6 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 
 		assertTrue(dbDir.mkdirs());
 		assertTrue(keyDir.mkdirs());
-		assertTrue(codeCacheDir.mkdirs());
-		assertTrue(codeCacheFile.createNewFile());
 		assertTrue(libDir.mkdirs());
 		assertTrue(libFile.createNewFile());
 		assertTrue(sharedPrefsDir.mkdirs());
@@ -130,8 +155,6 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 
 		assertFalse(dbDir.exists());
 		assertFalse(keyDir.exists());
-		assertTrue(codeCacheDir.exists());
-		assertTrue(codeCacheFile.exists());
 		assertTrue(libDir.exists());
 		assertTrue(libFile.exists());
 		assertTrue(sharedPrefsDir.exists());

bramble-android/witness.gradle

@@ -1,46 +1,44 @@
 dependencyVerification {
     verify = [
         'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
-        'com.android.tools.analytics-library:protos:26.5.1:protos-26.5.1.jar:8dde1130725461fe827f2a343d353f2b51e8870661fc860d7d5ebddb097ead4e',
-        'com.android.tools.analytics-library:shared:26.5.1:shared-26.5.1.jar:ccc2f3b00ec17b11401610ba68553544fc8fc517120e84439ac6eb86b875e18d',
-        'com.android.tools.analytics-library:tracker:26.5.1:tracker-26.5.1.jar:3a76984c0fe2e847ca7a8b35b4780ef0447a9d1666946cb8e60466318e0ab5ae',
-        'com.android.tools.build:aapt2-proto:0.4.0:aapt2-proto-0.4.0.jar:fac0435e08898f89eeeb9ca236bea707155ff816c12205ced285ad53604133ca',
-        'com.android.tools.build:apksig:3.5.1:apksig-3.5.1.jar:1fd33e7f009a2a0da766cfeec4211a09f548034b015c289a66d75dd8a9302f4a',
-        'com.android.tools.build:apkzlib:3.5.1:apkzlib-3.5.1.jar:9f330167cbe973b7db407692f74f4f6453b7ffa5f2048934b06280c2ceee60fa',
-        'com.android.tools.build:builder-model:3.5.1:builder-model-3.5.1.jar:39ea3c82b76b6e0c9f9fa88d93e0edc1dd4a0f1dfae0ef6fbf2d451da47e5450',
-        'com.android.tools.build:builder-test-api:3.5.1:builder-test-api-3.5.1.jar:a1b59305584cbcaa078fdc9cfb80871012755b822dd32e8da19add6f7bbcb762',
-        'com.android.tools.build:builder:3.5.1:builder-3.5.1.jar:e3a8d382434c5f60990730c4719fc814e85a898a33a1e96c1df8d627d3c6eea6',
-        'com.android.tools.build:gradle-api:3.5.1:gradle-api-3.5.1.jar:be9b41859bace11998f66b04ed944f87e413f3ad6da3c4665587699da125addc',
-        'com.android.tools.build:manifest-merger:26.5.1:manifest-merger-26.5.1.jar:dcad9ecb967251f4d750f55a4204a2b400e8fbfe5cb930a1d0d5dbe10ae8bdfc',
-        'com.android.tools.ddms:ddmlib:26.5.1:ddmlib-26.5.1.jar:b081aef2a4ed3f4d47cae4cdb128469735f25a114e026d37123bf9ffdec742a8',
-        'com.android.tools.external.com-intellij:intellij-core:26.5.1:intellij-core-26.5.1.jar:20eced30adc124805bd93488d9cd9d3e33e6bf7b48e9fe5a703d4983f894d450',
-        'com.android.tools.external.com-intellij:kotlin-compiler:26.5.1:kotlin-compiler-26.5.1.jar:5aed762dd54875b77ae7018d97c05756ff0c5b9fd02ec595dd396ccd14cc22cb',
-        'com.android.tools.external.org-jetbrains:uast:26.5.1:uast-26.5.1.jar:4bc8653d6c0943f40fee963a149e36c6baa45683d2530968a13f5007e3c40740',
-        'com.android.tools.layoutlib:layoutlib-api:26.5.1:layoutlib-api-26.5.1.jar:88732f11396c427273e515d23042e35633f4fe4295528a99b866aa2adf0efd9c',
-        'com.android.tools.lint:lint-api:26.5.1:lint-api-26.5.1.jar:ec33fcd72bfaf70dd841e03fbfd93f109c2e575aec146067c606689c3972f0de',
-        'com.android.tools.lint:lint-checks:26.5.1:lint-checks-26.5.1.jar:a1b9607d484aaae7a71dcecdc76f8003d8239af226c776894a2cf63f9e6c60d7',
-        'com.android.tools.lint:lint-gradle-api:26.5.1:lint-gradle-api-26.5.1.jar:82453fd98a8394cc84ed995c04d2cd744abd1d6589403427ba7eef53115406f3',
-        'com.android.tools.lint:lint-gradle:26.5.1:lint-gradle-26.5.1.jar:59465b56cf7db77c656d5f8195d721c3d48b6bdd0502d774de335bfe4baff00b',
-        'com.android.tools.lint:lint:26.5.1:lint-26.5.1.jar:336e4b04ec6f8b0f25879131b7a7862d77df83a1879ee5b71be26128755f8e2e',
-        'com.android.tools:annotations:26.5.1:annotations-26.5.1.jar:2c43c82f8c59d8f7a61e3239e1a2dc9f69dc342ec09af9b7c9f69b25337c0b6e',
-        'com.android.tools:common:26.5.1:common-26.5.1.jar:eccfa54486ed54c4e3123cc42195d023bd0dd21bcd2f0e4868e8c6fc70f8ef6b',
-        'com.android.tools:dvlib:26.5.1:dvlib-26.5.1.jar:46f93ad498b4756e7d867d2fe38c38890a80e7407a4ae459e4a8c8d5c5aeacfe',
-        'com.android.tools:repository:26.5.1:repository-26.5.1.jar:2b3ee791aa4c3e8ce60498c161a27ca7228816fc630eed4d9f25f2f36a106dce',
-        'com.android.tools:sdk-common:26.5.1:sdk-common-26.5.1.jar:365f749676c3574676fd465177c8a492f340816db2b520d6ed114d3b6e77bea7',
-        'com.android.tools:sdklib:26.5.1:sdklib-26.5.1.jar:007da104afb27c8c682a1628023fe9ec438249c8d15ef0fd6624c5bb8e23b696',
+        'com.android.tools.analytics-library:protos:26.4.0:protos-26.4.0.jar:ad760915586797d39319f402837b378bff3bb4ed583e3e0c48c965631fb2135f',
+        'com.android.tools.analytics-library:shared:26.4.0:shared-26.4.0.jar:1332106a905d48909c81268c9e414946de3e83487db394c6073b0a9b5c3d0ed2',
+        'com.android.tools.analytics-library:tracker:26.4.0:tracker-26.4.0.jar:d0020cfbfd4cd75935f2972d6a24089840d4a10df6f3ef2a796093217dd37796',
+        'com.android.tools.build:apksig:3.4.0:apksig-3.4.0.jar:91d5a1866139c69756280355a6f61b4d619d0516841580114f45a10f2177327e',
+        'com.android.tools.build:apkzlib:3.4.0:apkzlib-3.4.0.jar:8653c85f5fdf1dde840e8b8af7396aeb79c34b66e541b5860059616006535592',
+        'com.android.tools.build:builder-model:3.4.0:builder-model-3.4.0.jar:a88f138124a9f016a70bcb4760359a502f65c7deed56507ee4014f4dd9ea853b',
+        'com.android.tools.build:builder-test-api:3.4.0:builder-test-api-3.4.0.jar:31089ab1ec19ca7687a010867d2f3807513c805b8226979706f4247b5d4df26f',
+        'com.android.tools.build:builder:3.4.0:builder-3.4.0.jar:476221b5203a7f50089bf185ed95000a34b6f5020ef0a17815afd58606922679',
+        'com.android.tools.build:gradle-api:3.4.0:gradle-api-3.4.0.jar:215eca38f6719213c2f492b4d622cdd11676c66c9871f8a2aed0c66d00175628',
+        'com.android.tools.build:manifest-merger:26.4.0:manifest-merger-26.4.0.jar:29e45e690dedd165035e97c21c2ca94d0bd4ec16b6b210daa26669a582b6f220',
+        'com.android.tools.ddms:ddmlib:26.4.0:ddmlib-26.4.0.jar:93f56fe4630c3166adbd6c51d7bb602d96abb91b07ba5b1165fdcd071e88c940',
+        'com.android.tools.external.com-intellij:intellij-core:26.4.0:intellij-core-26.4.0.jar:30cb0e879d4424de9677a50b537fb628636b4a50f5470af5e52437980c41421f',
+        'com.android.tools.external.com-intellij:kotlin-compiler:26.4.0:kotlin-compiler-26.4.0.jar:dd1fe225c31a0e012dc025336363a5b783e2c5c20ffb69e77f8f57e89420d998',
+        'com.android.tools.external.org-jetbrains:uast:26.4.0:uast-26.4.0.jar:f25f3285b775a983327583ff6584dea54e447813ef69e0ce08b05a45b5f4aab0',
+        'com.android.tools.layoutlib:layoutlib-api:26.4.0:layoutlib-api-26.4.0.jar:52128f5cf293b224072be361919bfd416e59480ab7264ddcdbbf046b0d7a12e3',
+        'com.android.tools.lint:lint-api:26.4.0:lint-api-26.4.0.jar:fdb8fca8ae4c254f438338d03d72605e00ed106f2d5550405af41ca1c8509401',
+        'com.android.tools.lint:lint-checks:26.4.0:lint-checks-26.4.0.jar:4ff52d40488cd3e22b9c6b2eb67784e0c3269d0b42ef9d17689cd75a7b2bceb4',
+        'com.android.tools.lint:lint-gradle-api:26.4.0:lint-gradle-api-26.4.0.jar:714b7a85c7d2aa10daeab16e969fe7530c659d0728a7f24021da456870418d0f',
+        'com.android.tools.lint:lint-gradle:26.4.0:lint-gradle-26.4.0.jar:b8c130d273f522388734457e1b96790f41528fcec6fda9e8eaa4e4d95a07cfbb',
+        'com.android.tools.lint:lint:26.4.0:lint-26.4.0.jar:83aa062fb0405b60ed358d858c8c2955e1bae44a455b498068c6a60988755f00',
+        'com.android.tools:annotations:26.4.0:annotations-26.4.0.jar:a7955b8e19c3a2a861d6faa43a58b7c0d46ea9112188ee3e235c6f9f439ecc1a',
+        'com.android.tools:common:26.4.0:common-26.4.0.jar:ea40b94b3c1284ea7700f011388e2906a8363a66abd902891722b3c557984852',
+        'com.android.tools:dvlib:26.4.0:dvlib-26.4.0.jar:23af89c535b01ba36ceed1b6b309b672814eba624e643cd7dedf0519edad50cc',
+        'com.android.tools:repository:26.4.0:repository-26.4.0.jar:3d1763ab46199374dc6d94129bba11c70f1d5857e2c81a3ac4898abca40b176b',
+        'com.android.tools:sdk-common:26.4.0:sdk-common-26.4.0.jar:78a522525b30ffc6b7bf1299c831d24ce385f68a9f4878f8f752e9baefa31b0f',
+        'com.android.tools:sdklib:26.4.0:sdklib-26.4.0.jar:b854c23892013a326d761cf071c72cf3e038ed0469d10f4a356829fa56e4c132',
+        'com.google.code.findbugs:jsr305:1.3.9:jsr305-1.3.9.jar:905721a0eea90a81534abb7ee6ef4ea2e5e645fa1def0a5cd88402df1b46c9ed',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
-        'com.google.code.gson:gson:2.8.5:gson-2.8.5.jar:233a0149fc365c9f6edbd683cfe266b19bdc773be98eabdaf6b3c924b48e7d81',
-        'com.google.dagger:dagger-compiler:2.24:dagger-compiler-2.24.jar:3c5afb955fb188da485cb2c048eff37dce0e1530b9780a0f2f7187d16d1ccc1f',
-        'com.google.dagger:dagger-producers:2.24:dagger-producers-2.24.jar:f10f45b95191954d5d6b043fca9e62fb621d21bf70634b8f8476c7988b504c3a',
-        'com.google.dagger:dagger-spi:2.24:dagger-spi-2.24.jar:c038445d14dbcb4054e61bf49e05009edf26fce4fdc7ec1a9db544784f68e718',
-        'com.google.dagger:dagger:2.24:dagger-2.24.jar:550a6e46a6dfcdf1d764887b6090cea94f783327e50e5c73754f18facfc70b64',
-        'com.google.errorprone:error_prone_annotations:2.2.0:error_prone_annotations-2.2.0.jar:6ebd22ca1b9d8ec06d41de8d64e0596981d9607b42035f9ed374f9de271a481a',
+        'com.google.code.gson:gson:2.8.0:gson-2.8.0.jar:c6221763bd79c4f1c3dc7f750b5f29a0bb38b367b81314c4f71896e340c40825',
+        'com.google.dagger:dagger-compiler:2.22.1:dagger-compiler-2.22.1.jar:e5f28302cbe70a79d3620cddebfb8ec0736814f3980ffe1e673bfe3342f507d3',
+        'com.google.dagger:dagger-producers:2.22.1:dagger-producers-2.22.1.jar:f834a0082014213a68ff06a0f048d750178d02196c58b0b15beb367d32b97e35',
+        'com.google.dagger:dagger-spi:2.22.1:dagger-spi-2.22.1.jar:4b0b922793b3bcb91b99fabb75dba77c68afd7ae4c5f0c4fd6ba681f0a291c7d',
+        'com.google.dagger:dagger:2.22.1:dagger-2.22.1.jar:329d4340f24c4f5717af016c097e90668bfea2a5376e6aa9964b01cef3fd241a',
+        'com.google.errorprone:error_prone_annotations:2.1.3:error_prone_annotations-2.1.3.jar:03d0329547c13da9e17c634d1049ea2ead093925e290567e1a364fd6b1fc7ff8',
         'com.google.errorprone:javac-shaded:9-dev-r4023-3:javac-shaded-9-dev-r4023-3.jar:65bfccf60986c47fbc17c9ebab0be626afc41741e0a6ec7109e0768817a36f30',
         'com.google.googlejavaformat:google-java-format:1.5:google-java-format-1.5.jar:aa19ad7850fb85178aa22f2fddb163b84d6ce4d0035872f30d4408195ca1144e',
-        'com.google.guava:failureaccess:1.0.1:failureaccess-1.0.1.jar:a171ee4c734dd2da837e4b16be9df4661afab72a41adaf31eb84dfdaf936ca26',
-        'com.google.guava:guava:27.0.1-jre:guava-27.0.1-jre.jar:e1c814fd04492a27c38e0317eabeaa1b3e950ec8010239e400fe90ad6c9107b4',
-        'com.google.guava:guava:27.1-jre:guava-27.1-jre.jar:4a5aa70cc968a4d137e599ad37553e5cfeed2265e8c193476d7119036c536fe7',
-        'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava:listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:b372a037d4230aa57fbeffdef30fd6123f9c0c2db85d0aced00c91b974f33f99',
+        'com.google.guava:guava:25.0-jre:guava-25.0-jre.jar:3fd4341776428c7e0e5c18a7c10de129475b69ab9d30aeafbb5c277bb6074fa9',
+        'com.google.guava:guava:26.0-jre:guava-26.0-jre.jar:a0e9cabad665bc20bcd2b01f108e5fc03f756e13aea80abaadb9f407033bea2c',
         'com.google.j2objc:j2objc-annotations:1.1:j2objc-annotations-1.1.jar:2994a7eb78f2710bd3d3bfb639b2c94e219cedac0d4d084d516e78c16dddecf6',
         'com.google.jimfs:jimfs:1.1:jimfs-1.1.jar:c4828e28d7c0a930af9387510b3bada7daa5c04d7c25a75c7b8b081f1c257ddd',
         'com.google.protobuf:protobuf-java:3.4.0:protobuf-java-3.4.0.jar:dce7e66b32456a1b1198da0caff3a8acb71548658391e798c79369241e6490a4',
@@ -57,7 +55,6 @@ dependencyVerification {
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'javax.xml.bind:jaxb-api:2.2.12-b140109.1041:jaxb-api-2.2.12-b140109.1041.jar:b5e60cd8b7b5ff01ce4a74c5dd008f4fbd14ced3495d0b47b85cfedc182211f2',
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
-        'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
         'net.sf.jopt-simple:jopt-simple:4.9:jopt-simple-4.9.jar:26c5856e954b5f864db76f13b86919b59c6eecf9fd930b96baa8884626baf2f5',
         'net.sf.kxml:kxml2:2.3.0:kxml2-2.3.0.jar:f264dd9f79a1fde10ce5ecc53221eff24be4c9331c830b7d52f2f08a7b633de2',
         'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
@@ -69,22 +66,22 @@ dependencyVerification {
         'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
         'org.bouncycastle:bcpkix-jdk15on:1.56:bcpkix-jdk15on-1.56.jar:7043dee4e9e7175e93e0b36f45b1ec1ecb893c5f755667e8b916eb8dd201c6ca',
         'org.bouncycastle:bcprov-jdk15on:1.56:bcprov-jdk15on-1.56.jar:963e1ee14f808ffb99897d848ddcdb28fa91ddda867eb18d303e82728f878349',
-        'org.briarproject:obfs4proxy-android:0.0.11-2:obfs4proxy-android-0.0.11-2.zip:57e55cbe87aa2aac210fdbb6cd8cdeafe15f825406a08ebf77a8b787aa2c6a8a',
-        'org.briarproject:tor-android:0.3.5.10:tor-android-0.3.5.10.zip:edd83bf557fcff2105eaa0bdb3f607a6852ebe7360920929ae3039dd5f4774c5',
+        'org.briarproject:obfs4proxy-android:0.0.9:obfs4proxy-android-0.0.9.zip:9b7e9181535ea8d8bbe8ae6338e08cf4c5fc1e357a779393e0ce49586d459ae0',
+        'org.briarproject:tor-android:0.3.5.8:tor-android-0.3.5.8.zip:42a13a6f185be1a62f42e3f30ce66a3c099ac5ec890a65e7593111b65b44a54a',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
         'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
         'org.codehaus.groovy:groovy-all:2.4.15:groovy-all-2.4.15.jar:51d6c4e71782e85674239189499854359d380fb75e1a703756e3aaa5b98a5af0',
-        'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',
+        'org.codehaus.mojo:animal-sniffer-annotations:1.14:animal-sniffer-annotations-1.14.jar:2068320bd6bad744c3673ab048f67e30bef8f518996fa380033556600669905d',
         'org.glassfish.jaxb:jaxb-core:2.2.11:jaxb-core-2.2.11.jar:37bcaee8ebb04362c8352a5bf6221b86967ecdab5164c696b10b9a2bb587b2aa',
         'org.glassfish.jaxb:jaxb-runtime:2.2.11:jaxb-runtime-2.2.11.jar:a874f2351cfba8e2946be3002d10c18a6da8f21b52ba2acf52f2b85d5520ed70',
         'org.glassfish.jaxb:txw2:2.2.11:txw2-2.2.11.jar:272a3ccad45a4511351920cd2a8633c53cab8d5220c7a92954da5526bb5eafea',
         '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.jetbrains.kotlin:kotlin-reflect:1.3.50:kotlin-reflect-1.3.50.jar:64583199ea5a54aefd1bd1595288925f784226ee562d1dd279011c6075b3d7a4',
-        'org.jetbrains.kotlin:kotlin-stdlib-common:1.3.50:kotlin-stdlib-common-1.3.50.jar:8ce678e88e4ba018b66dacecf952471e4d7dfee156a8a819760a5a5ff29d323c',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.50:kotlin-stdlib-jdk7-1.3.50.jar:9a026639e76212f8d57b86d55b075394c2e009f1979110751d34c05c5f75d57b',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.50:kotlin-stdlib-jdk8-1.3.50.jar:1b351fb6e09c14b55525c74c1f4cf48942eae43c348b7bc764a5e6e423d4da0c',
-        'org.jetbrains.kotlin:kotlin-stdlib:1.3.50:kotlin-stdlib-1.3.50.jar:e6f05746ee0366d0b52825a090fac474dcf44082c9083bbb205bd16976488d6c',
+        'org.jetbrains.kotlin:kotlin-reflect:1.3.21:kotlin-reflect-1.3.21.jar:a3065c822633191e0a3e3ee12a29bec234fc4b2864a6bb87ef48cce3e9e0c26a',
+        'org.jetbrains.kotlin:kotlin-stdlib-common:1.3.21:kotlin-stdlib-common-1.3.21.jar:cea61f7b611895e64f58569a9757fc0ab0d582f107211e1930e0ce2a0add52a7',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.21:kotlin-stdlib-jdk7-1.3.21.jar:a87875604fd42140da6938ae4d35ee61081f4482536efc6d2615b8b626a198af',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.21:kotlin-stdlib-jdk8-1.3.21.jar:5823ed66ac122a1c55442ebca5a209a843ccd87f562edc31a787f3d2e47f74d4',
+        'org.jetbrains.kotlin:kotlin-stdlib:1.3.21:kotlin-stdlib-1.3.21.jar:38ba2370d9f06f50433e06b2ca775b94473c2e2785f410926079ab793c72b034',
         'org.jetbrains.trove4j:trove4j:20160824:trove4j-20160824.jar:1917871c8deb468307a584680c87a44572f5a8b0b98c6d397fc0f5f86596dbe7',
         'org.jetbrains:annotations:13.0:annotations-13.0.jar:ace2a10dc8e2d5fd34925ecac03e4988b2c0f851650c94b8cef49ba1bd111478',
         'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',

bramble-api/build.gradle

@@ -7,7 +7,7 @@ apply plugin: 'witness'
 apply from: 'witness.gradle'
 
 dependencies {
-	implementation "com.google.dagger:dagger:2.24"
+	implementation "com.google.dagger:dagger:2.22.1"
 	implementation 'com.google.code.findbugs:jsr305:3.0.2'
 
 	testImplementation 'junit:junit:4.12'

bramble-api/src/main/java/org/briarproject/bramble/api/FeatureFlags.java

@@ -6,4 +6,6 @@ package org.briarproject.bramble.api;
 public interface FeatureFlags {
 
 	boolean shouldEnableImageAttachments();
+
+	boolean shouldEnableRemoteContacts();
 }

bramble-api/src/main/java/org/briarproject/bramble/api/account/AccountManager.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.api.account;
 
-import org.briarproject.bramble.api.crypto.DecryptionException;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
@@ -14,8 +13,7 @@ public interface AccountManager {
 	 * Returns true if the manager has the database key. This will be false
 	 * before {@link #createAccount(String, String)} or {@link #signIn(String)}
 	 * has been called, and true after {@link #createAccount(String, String)}
-	 * or {@link #signIn(String)} has returned true, until
-	 * {@link #deleteAccount()} is called or the process exits.
+	 * or {@link #signIn(String)} has returned true, until the process exits.
 	 */
 	boolean hasDatabaseKey();
 
@@ -24,22 +22,25 @@ public interface AccountManager {
 	 * before {@link #createAccount(String, String)} or {@link #signIn(String)}
 	 * has been called, and non-null after
 	 * {@link #createAccount(String, String)} or {@link #signIn(String)} has
-	 * returned true, until {@link #deleteAccount()} is called or the process
-	 * exits.
+	 * returned true, until the process exits.
 	 */
 	@Nullable
 	SecretKey getDatabaseKey();
 
 	/**
-	 * Returns true if the encrypted database key can be loaded from disk.
+	 * Returns true if the encrypted database key can be loaded from disk, and
+	 * the database directory exists and is a directory.
 	 */
 	boolean accountExists();
 
 	/**
 	 * Creates an identity with the given name and registers it with the
 	 * {@link IdentityManager}. Creates a database key, encrypts it with the
-	 * given password and stores it on disk. {@link #accountExists()} will
-	 * return true after this method returns true.
+	 * given password and stores it on disk.
+	 * <p/>
+	 * This method does not create the database directory, so
+	 * {@link #accountExists()} will continue to return false until the
+	 * database directory is created.
 	 */
 	boolean createAccount(String name, String password);
 
@@ -53,19 +54,17 @@ public interface AccountManager {
 	 * Loads the encrypted database key from disk and decrypts it with the
 	 * given password.
 	 *
-	 * @throws DecryptionException If the database key could not be loaded and
-	 * decrypted.
+	 * @return true if the database key was successfully loaded and decrypted.
 	 */
-	void signIn(String password) throws DecryptionException;
+	boolean signIn(String password);
 
 	/**
 	 * Loads the encrypted database key from disk, decrypts it with the old
 	 * password, encrypts it with the new password, and stores it on disk,
 	 * replacing the old key.
 	 *
-	 * @throws DecryptionException If the database key could not be loaded and
-	 * decrypted.
+	 * @return true if the database key was successfully loaded, re-encrypted
+	 * and stored.
 	 */
-	void changePassword(String oldPassword, String newPassword)
-			throws DecryptionException;
+	boolean changePassword(String oldPassword, String newPassword);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/connection/InterruptibleConnection.java

@@ -1,19 +0,0 @@
-package org.briarproject.bramble.api.connection;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * A duplex sync connection that can be closed by interrupting its outgoing
- * sync session.
- */
-@NotNullByDefault
-public interface InterruptibleConnection {
-
-	/**
-	 * Interrupts the connection's outgoing sync session. If the underlying
-	 * transport connection is alive and the remote peer is cooperative, this
-	 * should result in both sync sessions ending and the connection being
-	 * cleanly closed.
-	 */
-	void interruptOutgoingSession();
-}

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

@@ -4,10 +4,8 @@ import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.UnsupportedVersionException;
 import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.api.db.ContactExistsException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.NoSuchContactException;
-import org.briarproject.bramble.api.db.PendingContactExistsException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
@@ -119,14 +117,9 @@ public interface ContactManager {
 	 * @throws FormatException If the link is invalid
 	 * @throws GeneralSecurityException If the pending contact's handshake
 	 * public key is invalid
-	 * @throws ContactExistsException If a contact with the same handshake
-	 * public key already exists
-	 * @throws PendingContactExistsException If a pending contact with the same
-	 * handshake public key already exists
 	 */
 	PendingContact addPendingContact(String link, String alias)
-			throws DbException, FormatException, GeneralSecurityException,
-			ContactExistsException, PendingContactExistsException;
+			throws DbException, FormatException, GeneralSecurityException;
 
 	/**
 	 * Returns the pending contact with the given ID.

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

@@ -132,33 +132,17 @@ public interface CryptoComponent {
 	 * storage. The encryption and authentication keys are derived from the
 	 * given password. The ciphertext will be decryptable using the same
 	 * password after the app restarts.
-	 *
-	 * @param keyStrengthener Used to strengthen the password-based key. If
-	 * null, the password-based key will not be strengthened
 	 */
-	byte[] encryptWithPassword(byte[] plaintext, String password,
-			@Nullable KeyStrengthener keyStrengthener);
+	byte[] encryptWithPassword(byte[] plaintext, String password);
 
 	/**
 	 * Decrypts and authenticates the given ciphertext that has been read from
 	 * storage. The encryption and authentication keys are derived from the
-	 * given password.
-	 *
-	 * @param keyStrengthener Used to strengthen the password-based key. If
-	 * null, or if strengthening was not used when encrypting the ciphertext,
-	 * the password-based key will not be strengthened
-	 * @throws DecryptionException If the ciphertext cannot be decrypted and
+	 * given password. Returns null if the ciphertext cannot be decrypted and
 	 * authenticated (for example, if the password is wrong).
 	 */
-	byte[] decryptWithPassword(byte[] ciphertext, String password,
-			@Nullable KeyStrengthener keyStrengthener)
-			throws DecryptionException;
-
-	/**
-	 * Returns true if the given ciphertext was encrypted using a strengthened
-	 * key. The validity of the ciphertext is not checked.
-	 */
-	boolean isEncryptedWithStrengthenedKey(byte[] ciphertext);
+	@Nullable
+	byte[] decryptWithPassword(byte[] ciphertext, String password);
 
 	/**
 	 * Encrypts the given plaintext to the given public key.

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

@@ -1,17 +0,0 @@
-package org.briarproject.bramble.api.crypto;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-@NotNullByDefault
-public class DecryptionException extends Exception {
-
-	private final DecryptionResult result;
-
-	public DecryptionException(DecryptionResult result) {
-		this.result = result;
-	}
-
-	public DecryptionResult getDecryptionResult() {
-		return result;
-	}
-}

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

@@ -1,29 +0,0 @@
-package org.briarproject.bramble.api.crypto;
-
-/**
- * The result of a password-based decryption operation.
- */
-public enum DecryptionResult {
-
-	/**
-	 * Decryption succeeded.
-	 */
-	SUCCESS,
-
-	/**
-	 * Decryption failed because the format of the ciphertext was invalid.
-	 */
-	INVALID_CIPHERTEXT,
-
-	/**
-	 * Decryption failed because the {@link KeyStrengthener} used for
-	 * encryption was not available for decryption.
-	 */
-	KEY_STRENGTHENER_ERROR,
-
-	/**
-	 * Decryption failed because the password used for decryption did not match
-	 * the password used for encryption.
-	 */
-	INVALID_PASSWORD
-}

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

@@ -1,23 +0,0 @@
-package org.briarproject.bramble.api.crypto;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * Interface for strengthening a password-based key, for example by using a
- * key stored in a key management service or hardware security module.
- */
-@NotNullByDefault
-public interface KeyStrengthener {
-
-	/**
-	 * Returns true if the strengthener has been initialised.
-	 */
-	@SuppressWarnings("BooleanMethodIsAlwaysInverted")
-	boolean isInitialised();
-
-	/**
-	 * Initialises the strengthener if necessary and returns a strong key
-	 * derived from the given key.
-	 */
-	SecretKey strengthenKey(SecretKey k);
-}

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

@@ -83,7 +83,7 @@ public interface DatabaseComponent extends TransactionManager {
 	/**
 	 * Stores a pending contact.
 	 */
-	void addPendingContact(Transaction txn, PendingContact p, AuthorId local)
+	void addPendingContact(Transaction txn, PendingContact p)
 			throws DbException;
 
 	/**

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

@@ -1,29 +1,13 @@
 package org.briarproject.bramble.api.db;
 
-import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.File;
 
-import javax.annotation.Nullable;
-
 @NotNullByDefault
 public interface DatabaseConfig {
 
-	/**
-	 * Returns the directory where the database stores its data.
-	 */
 	File getDatabaseDirectory();
 
-	/**
-	 * Returns the directory where the encrypted database key is stored.
-	 */
 	File getDatabaseKeyDirectory();
-
-	/**
-	 * Returns a {@link KeyStrengthener} for strengthening the encryption of
-	 * the database key, or null if no strengthener should be used.
-	 */
-	@Nullable
-	KeyStrengthener getKeyStrengthener();
 }

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

@@ -1,21 +1,9 @@
 package org.briarproject.bramble.api.db;
 
-import org.briarproject.bramble.api.contact.PendingContact;
-
 /**
  * Thrown when a duplicate pending contact is added to the database. This
  * exception may occur due to concurrent updates and does not indicate a
  * database error.
  */
 public class PendingContactExistsException extends DbException {
-
-	private final PendingContact pendingContact;
-
-	public PendingContactExistsException(PendingContact pendingContact) {
-		this.pendingContact = pendingContact;
-	}
-
-	public PendingContact getPendingContact() {
-		return pendingContact;
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/io/TimeoutMonitor.java

@@ -1,15 +0,0 @@
-package org.briarproject.bramble.api.io;
-
-import java.io.InputStream;
-
-public interface TimeoutMonitor {
-
-	/**
-	 * Returns an {@link InputStream} that wraps the given stream and allows
-	 * read timeouts to be detected.
-	 *
-	 * @param timeoutMs The read timeout in milliseconds. Timeouts will be
-	 * detected eventually but are not guaranteed to be detected immediately.
-	 */
-	InputStream createTimeoutInputStream(InputStream in, long timeoutMs);
-}

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

@@ -1,11 +1,8 @@
-package org.briarproject.bramble.api.connection;
+package org.briarproject.bramble.api.plugin;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 
 @NotNullByDefault

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

@@ -1,17 +1,14 @@
-package org.briarproject.bramble.api.connection;
+package org.briarproject.bramble.api.plugin;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.PluginConfig;
-import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
 import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
 import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
 import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionClosedEvent;
 import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionOpenedEvent;
-import org.briarproject.bramble.api.sync.Priority;
 
 import java.util.Collection;
 
@@ -23,57 +20,25 @@ public interface ConnectionRegistry {
 
 	/**
 	 * Registers a connection with the given contact over the given transport.
-	 * <p>
 	 * Broadcasts {@link ConnectionOpenedEvent}. Also broadcasts
 	 * {@link ContactConnectedEvent} if this is the only connection with the
 	 * contact.
 	 */
-	void registerConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn, boolean incoming);
+	void registerConnection(ContactId c, TransportId t, boolean incoming);
 
 	/**
 	 * Unregisters a connection with the given contact over the given transport.
-	 * <p>
 	 * Broadcasts {@link ConnectionClosedEvent}. Also broadcasts
 	 * {@link ContactDisconnectedEvent} if this is the only connection with
 	 * the contact.
 	 */
-	void unregisterConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn, boolean incoming, boolean exception);
-
-	/**
-	 * Sets the {@link Priority priority} of a connection that was previously
-	 * registered via {@link #registerConnection(ContactId, TransportId,
-	 * InterruptibleConnection, boolean)}.
-	 * <p>
-	 * If the registry has any "better" connections with the given contact, the
-	 * given connection will be interrupted. If the registry has any "worse"
-	 * connections with the given contact, those connections will be
-	 * interrupted.
-	 * <p>
-	 * Connection A is considered "better" than connection B if both
-	 * connections have had their priorities set, and either A's transport is
-	 * {@link PluginConfig#getTransportPreferences() preferred} to B's, or
-	 * they use the same transport and A has higher {@link Priority priority}
-	 * than B.
-	 * <p>
-	 * For backward compatibility, connections without priorities are not
-	 * considered better or worse than other connections.
-	 */
-	void setPriority(ContactId c, TransportId t, InterruptibleConnection conn,
-			Priority priority);
+	void unregisterConnection(ContactId c, TransportId t, boolean incoming);
 
 	/**
 	 * Returns any contacts that are connected via the given transport.
 	 */
 	Collection<ContactId> getConnectedContacts(TransportId t);
 
-	/**
-	 * Returns any contacts that are connected via the given transport or any
-	 * {@link PluginConfig#getTransportPreferences() better} transport.
-	 */
-	Collection<ContactId> getConnectedOrBetterContacts(TransportId t);
-
 	/**
 	 * Returns true if the given contact is connected via the given transport.
 	 */

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

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

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

@@ -5,8 +5,6 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPluginFactory;
 
 import java.util.Collection;
-import java.util.List;
-import java.util.Map;
 
 @NotNullByDefault
 public interface PluginConfig {
@@ -16,11 +14,4 @@ public interface PluginConfig {
 	Collection<SimplexPluginFactory> getSimplexFactories();
 
 	boolean shouldPoll();
-
-	/**
-	 * Returns a map representing transport preferences. For each entry in the
-	 * map, connections via the transports identified by the value are
-	 * preferred to connections via the transport identified by the key.
-	 */
-	Map<TransportId, List<TransportId>> getTransportPreferences();
 }

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

@@ -4,7 +4,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.properties.TransportProperties;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -15,8 +14,6 @@ import java.util.concurrent.atomic.AtomicBoolean;
 public abstract class AbstractDuplexTransportConnection
 		implements DuplexTransportConnection {
 
-	protected final TransportProperties remote = new TransportProperties();
-
 	private final Plugin plugin;
 	private final Reader reader;
 	private final Writer writer;
@@ -47,11 +44,6 @@ public abstract class AbstractDuplexTransportConnection
 		return writer;
 	}
 
-	@Override
-	public TransportProperties getRemoteProperties() {
-		return remote;
-	}
-
 	private class Reader implements TransportConnectionReader {
 
 		@Override

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

@@ -3,7 +3,6 @@ package org.briarproject.bramble.api.plugin.duplex;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.properties.TransportProperties;
 
 /**
  * An interface for reading and writing data over a duplex transport. The
@@ -24,10 +23,4 @@ public interface DuplexTransportConnection {
 	 * for writing to the connection.
 	 */
 	TransportConnectionWriter getWriter();
-
-	/**
-	 * Returns a possibly empty set of {@link TransportProperties} describing
-	 * the remote peer.
-	 */
-	TransportProperties getRemoteProperties();
 }

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

@@ -13,14 +13,13 @@ public class ConnectionClosedEvent extends Event {
 
 	private final ContactId contactId;
 	private final TransportId transportId;
-	private final boolean incoming, exception;
+	private final boolean incoming;
 
 	public ConnectionClosedEvent(ContactId contactId, TransportId transportId,
-			boolean incoming, boolean exception) {
+			boolean incoming) {
 		this.contactId = contactId;
 		this.transportId = transportId;
 		this.incoming = incoming;
-		this.exception = exception;
 	}
 
 	public ContactId getContactId() {
@@ -34,8 +33,4 @@ public class ConnectionClosedEvent extends Event {
 	public boolean isIncoming() {
 		return incoming;
 	}
-
-	public boolean isException() {
-		return exception;
-	}
 }

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

@@ -11,28 +11,4 @@ public interface TransportPropertyConstants {
 	 * The maximum length of a property's key or value in UTF-8 bytes.
 	 */
 	int MAX_PROPERTY_LENGTH = 100;
-
-	/**
-	 * Message metadata key for the transport ID of a local or remote update,
-	 * as a BDF string.
-	 */
-	String MSG_KEY_TRANSPORT_ID = "transportId";
-
-	/**
-	 * Message metadata key for the version number of a local or remote update,
-	 * as a BDF long.
-	 */
-	String MSG_KEY_VERSION = "version";
-
-	/**
-	 * Message metadata key for whether an update is local or remote, as a BDF
-	 * boolean.
-	 */
-	String MSG_KEY_LOCAL = "local";
-
-	/**
-	 * Group metadata key for any discovered transport properties of the
-	 * contact, as a BDF dictionary.
-	 */
-	String GROUP_KEY_DISCOVERED = "discovered";
 }

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

@@ -34,14 +34,6 @@ public interface TransportPropertyManager {
 	void addRemoteProperties(Transaction txn, ContactId c,
 			Map<TransportId, TransportProperties> props) throws DbException;
 
-	/**
-	 * Stores the given properties discovered from an incoming transport
-	 * connection. They will be overridden by any properties received while
-	 * adding the contact or synced from the contact.
-	 */
-	void addRemotePropertiesFromConnection(ContactId c, TransportId t,
-			TransportProperties props) throws DbException;
-
 	/**
 	 * Returns the local transport properties for all transports.
 	 */

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

@@ -1,23 +0,0 @@
-package org.briarproject.bramble.api.sync;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * A record containing a nonce for choosing between redundant sessions.
- */
-@Immutable
-@NotNullByDefault
-public class Priority {
-
-	private final byte[] nonce;
-
-	public Priority(byte[] nonce) {
-		this.nonce = nonce;
-	}
-
-	public byte[] getNonce() {
-		return nonce;
-	}
-}

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

@@ -1,13 +0,0 @@
-package org.briarproject.bramble.api.sync;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * An interface for handling a {@link Priority} record received by an
- * incoming {@link SyncSession}.
- */
-@NotNullByDefault
-public interface PriorityHandler {
-
-	void handle(Priority p);
-}

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

@@ -10,5 +10,4 @@ public interface RecordTypes {
 	byte OFFER = 2;
 	byte REQUEST = 3;
 	byte VERSIONS = 4;
-	byte PRIORITY = 5;
 }

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

@@ -49,10 +49,4 @@ public interface SyncConstants {
 	 * simultaneously.
 	 */
 	int MAX_SUPPORTED_VERSIONS = 10;
-
-	/**
-	 * The length of the priority nonce used for choosing between redundant
-	 * connections.
-	 */
-	int PRIORITY_NONCE_BYTES = 16;
 }

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

@@ -28,8 +28,4 @@ public interface SyncRecordReader {
 	boolean hasVersions() throws IOException;
 
 	Versions readVersions() throws IOException;
-
-	boolean hasPriority() throws IOException;
-
-	Priority readPriority() throws IOException;
 }

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

@@ -17,7 +17,5 @@ public interface SyncRecordWriter {
 
 	void writeVersions(Versions v) throws IOException;
 
-	void writePriority(Priority p) throws IOException;
-
 	void flush() throws IOException;
 }

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

@@ -6,18 +6,14 @@ import org.briarproject.bramble.api.transport.StreamWriter;
 
 import java.io.InputStream;
 
-import javax.annotation.Nullable;
-
 @NotNullByDefault
 public interface SyncSessionFactory {
 
-	SyncSession createIncomingSession(ContactId c, InputStream in,
-			PriorityHandler handler);
+	SyncSession createIncomingSession(ContactId c, InputStream in);
 
 	SyncSession createSimplexOutgoingSession(ContactId c, int maxLatency,
 			StreamWriter streamWriter);
 
 	SyncSession createDuplexOutgoingSession(ContactId c, int maxLatency,
-			int maxIdleTime, StreamWriter streamWriter,
-			@Nullable Priority priority);
+			int maxIdleTime, StreamWriter streamWriter);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/versioning/ClientVersion.java

@@ -1,63 +0,0 @@
-package org.briarproject.bramble.api.versioning;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.ClientId;
-
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
-public class ClientVersion implements Comparable<ClientVersion> {
-
-	private final ClientMajorVersion majorVersion;
-	private final int minorVersion;
-
-	public ClientVersion(ClientMajorVersion majorVersion,
-			int minorVersion) {
-		this.majorVersion = majorVersion;
-		this.minorVersion = minorVersion;
-	}
-
-	public ClientVersion(ClientId clientId, int majorVersion,
-			int minorVersion) {
-		this(new ClientMajorVersion(clientId, majorVersion), minorVersion);
-	}
-
-	public ClientMajorVersion getClientMajorVersion() {
-		return majorVersion;
-	}
-
-	public ClientId getClientId() {
-		return majorVersion.getClientId();
-	}
-
-	public int getMajorVersion() {
-		return majorVersion.getMajorVersion();
-	}
-
-	public int getMinorVersion() {
-		return minorVersion;
-	}
-
-	@Override
-	public boolean equals(Object o) {
-		if (o instanceof ClientVersion) {
-			ClientVersion cv = (ClientVersion) o;
-			return majorVersion.equals(cv.majorVersion)
-					&& minorVersion == cv.minorVersion;
-		}
-		return false;
-	}
-
-	@Override
-	public int hashCode() {
-		return majorVersion.hashCode();
-	}
-
-	@Override
-	public int compareTo(ClientVersion cv) {
-		int compare = majorVersion.compareTo(cv.majorVersion);
-		if (compare != 0) return compare;
-		return minorVersion - cv.minorVersion;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/versioning/event/ClientVersionUpdatedEvent.java

@@ -1,34 +0,0 @@
-package org.briarproject.bramble.api.versioning.event;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.versioning.ClientVersion;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when we receive a client versioning update from
- * a contact.
- */
-@Immutable
-@NotNullByDefault
-public class ClientVersionUpdatedEvent extends Event {
-
-	private final ContactId contactId;
-	private final ClientVersion clientVersion;
-
-	public ClientVersionUpdatedEvent(ContactId contactId,
-			ClientVersion clientVersion) {
-		this.contactId = contactId;
-		this.clientVersion = clientVersion;
-	}
-
-	public ContactId getContactId() {
-		return contactId;
-	}
-
-	public ClientVersion getClientVersion() {
-		return clientVersion;
-	}
-}

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

@@ -117,10 +117,4 @@ public class IoUtils {
 			throw new IOException(e);
 		}
 	}
-
-	public static boolean isNonEmptyDirectory(File f) {
-		if (!f.isDirectory()) return false;
-		File[] children = f.listFiles();
-		return children != null && children.length > 0;
-	}
 }

bramble-api/witness.gradle

@@ -2,7 +2,7 @@ dependencyVerification {
     verify = [
         'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
-        'com.google.dagger:dagger:2.24:dagger-2.24.jar:550a6e46a6dfcdf1d764887b6090cea94f783327e50e5c73754f18facfc70b64',
+        'com.google.dagger:dagger:2.22.1:dagger-2.22.1.jar:329d4340f24c4f5717af016c097e90668bfea2a5376e6aa9964b01cef3fd241a',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
         'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',

bramble-core/build.gradle

@@ -17,7 +17,7 @@ dependencies {
 	implementation 'org.whispersystems:curve25519-java:0.5.0'
 	implementation 'org.briarproject:jtorctl:0.3'
 
-	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
+	annotationProcessor 'com.google.dagger:dagger-compiler:2.22.1'
 
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
 	testImplementation 'org.hsqldb:hsqldb:2.3.5' // The last version that supports Java 1.6
@@ -26,7 +26,7 @@ dependencies {
 	testImplementation "org.jmock:jmock-junit4:2.8.2"
 	testImplementation "org.jmock:jmock-legacy:2.8.2"
 
-	testAnnotationProcessor 'com.google.dagger:dagger-compiler:2.24'
+	testAnnotationProcessor 'com.google.dagger:dagger-compiler:2.22.1'
 
 	signature 'org.codehaus.mojo.signature:java16:1.1@signature'
 }

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

@@ -39,21 +39,18 @@ public interface BrambleCoreEagerSingletons {
 
 	void inject(VersioningModule.EagerSingletons init);
 
-	class Helper {
-
-		public static void injectEagerSingletons(BrambleCoreEagerSingletons c) {
-			c.inject(new ContactModule.EagerSingletons());
-			c.inject(new CryptoExecutorModule.EagerSingletons());
-			c.inject(new DatabaseExecutorModule.EagerSingletons());
-			c.inject(new IdentityModule.EagerSingletons());
-			c.inject(new LifecycleModule.EagerSingletons());
-			c.inject(new RendezvousModule.EagerSingletons());
-			c.inject(new PluginModule.EagerSingletons());
-			c.inject(new PropertiesModule.EagerSingletons());
-			c.inject(new SystemModule.EagerSingletons());
-			c.inject(new TransportModule.EagerSingletons());
-			c.inject(new ValidationModule.EagerSingletons());
-			c.inject(new VersioningModule.EagerSingletons());
-		}
+	default void injectBrambleCoreEagerSingletons() {
+		inject(new ContactModule.EagerSingletons());
+		inject(new CryptoExecutorModule.EagerSingletons());
+		inject(new DatabaseExecutorModule.EagerSingletons());
+		inject(new IdentityModule.EagerSingletons());
+		inject(new LifecycleModule.EagerSingletons());
+		inject(new RendezvousModule.EagerSingletons());
+		inject(new PluginModule.EagerSingletons());
+		inject(new PropertiesModule.EagerSingletons());
+		inject(new SystemModule.EagerSingletons());
+		inject(new TransportModule.EagerSingletons());
+		inject(new ValidationModule.EagerSingletons());
+		inject(new VersioningModule.EagerSingletons());
 	}
 }

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

@@ -1,7 +1,6 @@
 package org.briarproject.bramble;
 
 import org.briarproject.bramble.client.ClientModule;
-import org.briarproject.bramble.connection.ConnectionModule;
 import org.briarproject.bramble.contact.ContactModule;
 import org.briarproject.bramble.crypto.CryptoExecutorModule;
 import org.briarproject.bramble.crypto.CryptoModule;
@@ -10,7 +9,6 @@ import org.briarproject.bramble.db.DatabaseExecutorModule;
 import org.briarproject.bramble.db.DatabaseModule;
 import org.briarproject.bramble.event.EventModule;
 import org.briarproject.bramble.identity.IdentityModule;
-import org.briarproject.bramble.io.IoModule;
 import org.briarproject.bramble.keyagreement.KeyAgreementModule;
 import org.briarproject.bramble.lifecycle.LifecycleModule;
 import org.briarproject.bramble.plugin.PluginModule;
@@ -29,7 +27,6 @@ import dagger.Module;
 
 @Module(includes = {
 		ClientModule.class,
-		ConnectionModule.class,
 		ContactModule.class,
 		CryptoModule.class,
 		CryptoExecutorModule.class,
@@ -38,7 +35,6 @@ import dagger.Module;
 		DatabaseExecutorModule.class,
 		EventModule.class,
 		IdentityModule.class,
-		IoModule.class,
 		KeyAgreementModule.class,
 		LifecycleModule.class,
 		PluginModule.class,
@@ -54,4 +50,8 @@ import dagger.Module;
 		VersioningModule.class
 })
 public class BrambleCoreModule {
+
+	public static void initEagerSingletons(BrambleCoreEagerSingletons c) {
+		c.injectBrambleCoreEagerSingletons();
+	}
 }

bramble-core/src/main/java/org/briarproject/bramble/account/AccountManagerImpl.java

@@ -2,8 +2,6 @@ package org.briarproject.bramble.account;
 
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.crypto.DecryptionException;
-import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.identity.Identity;
@@ -18,15 +16,12 @@ import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.nio.charset.Charset;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
 import javax.inject.Inject;
 
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.INVALID_CIPHERTEXT;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.StringUtils.fromHexString;
 import static org.briarproject.bramble.util.StringUtils.toHexString;
@@ -73,10 +68,9 @@ class AccountManagerImpl implements AccountManager {
 		return databaseKey;
 	}
 
-	// Package access for testing
-	@GuardedBy("stateChangeLock")
+	// Locking: stateChangeLock
 	@Nullable
-	String loadEncryptedDatabaseKey() {
+	protected String loadEncryptedDatabaseKey() {
 		String key = readDbKeyFromFile(dbKeyFile);
 		if (key == null) {
 			LOG.info("No database key in primary file");
@@ -89,7 +83,7 @@ class AccountManagerImpl implements AccountManager {
 		return key;
 	}
 
-	@GuardedBy("stateChangeLock")
+	// Locking: stateChangeLock
 	@Nullable
 	private String readDbKeyFromFile(File f) {
 		if (!f.exists()) {
@@ -98,7 +92,7 @@ class AccountManagerImpl implements AccountManager {
 		}
 		try {
 			BufferedReader reader = new BufferedReader(new InputStreamReader(
-					new FileInputStream(f), Charset.forName("UTF-8")));
+					new FileInputStream(f), "UTF-8"));
 			String key = reader.readLine();
 			reader.close();
 			return key;
@@ -108,9 +102,8 @@ class AccountManagerImpl implements AccountManager {
 		}
 	}
 
-	// Package access for testing
-	@GuardedBy("stateChangeLock")
-	boolean storeEncryptedDatabaseKey(String hex) {
+	// Locking: stateChangeLock
+	protected boolean storeEncryptedDatabaseKey(String hex) {
 		LOG.info("Storing database key in file");
 		// Create the directory if necessary
 		if (databaseConfig.getDatabaseKeyDirectory().mkdirs())
@@ -147,10 +140,10 @@ class AccountManagerImpl implements AccountManager {
 		}
 	}
 
-	@GuardedBy("stateChangeLock")
+	// Locking: stateChangeLock
 	private void writeDbKeyToFile(String key, File f) throws IOException {
 		FileOutputStream out = new FileOutputStream(f);
-		out.write(key.getBytes(Charset.forName("UTF-8")));
+		out.write(key.getBytes("UTF-8"));
 		out.flush();
 		out.close();
 	}
@@ -158,7 +151,8 @@ class AccountManagerImpl implements AccountManager {
 	@Override
 	public boolean accountExists() {
 		synchronized (stateChangeLock) {
-			return loadEncryptedDatabaseKey() != null;
+			return loadEncryptedDatabaseKey() != null
+					&& databaseConfig.getDatabaseDirectory().isDirectory();
 		}
 	}
 
@@ -176,11 +170,10 @@ class AccountManagerImpl implements AccountManager {
 		}
 	}
 
-	@GuardedBy("stateChangeLock")
+	// Locking: stateChangeLock
 	private boolean encryptAndStoreDatabaseKey(SecretKey key, String password) {
 		byte[] plaintext = key.getBytes();
-		byte[] ciphertext = crypto.encryptWithPassword(plaintext, password,
-				databaseConfig.getKeyStrengthener());
+		byte[] ciphertext = crypto.encryptWithPassword(plaintext, password);
 		return storeEncryptedDatabaseKey(toHexString(ciphertext));
 	}
 
@@ -195,41 +188,37 @@ class AccountManagerImpl implements AccountManager {
 	}
 
 	@Override
-	public void signIn(String password) throws DecryptionException {
+	public boolean signIn(String password) {
 		synchronized (stateChangeLock) {
-			databaseKey = loadAndDecryptDatabaseKey(password);
+			SecretKey key = loadAndDecryptDatabaseKey(password);
+			if (key == null) return false;
+			databaseKey = key;
+			return true;
 		}
 	}
 
-	@GuardedBy("stateChangeLock")
-	private SecretKey loadAndDecryptDatabaseKey(String password)
-			throws DecryptionException {
+	// Locking: stateChangeLock
+	@Nullable
+	private SecretKey loadAndDecryptDatabaseKey(String password) {
 		String hex = loadEncryptedDatabaseKey();
 		if (hex == null) {
 			LOG.warning("Failed to load encrypted database key");
-			throw new DecryptionException(INVALID_CIPHERTEXT);
+			return null;
 		}
 		byte[] ciphertext = fromHexString(hex);
-		KeyStrengthener keyStrengthener = databaseConfig.getKeyStrengthener();
-		byte[] plaintext = crypto.decryptWithPassword(ciphertext, password,
-				keyStrengthener);
-		SecretKey key = new SecretKey(plaintext);
-		// If the DB key was encrypted with a weak key and a key strengthener
-		// is now available, re-encrypt the DB key with a strengthened key
-		if (keyStrengthener != null &&
-				!crypto.isEncryptedWithStrengthenedKey(ciphertext)) {
-			LOG.info("Re-encrypting database key with strengthened key");
-			encryptAndStoreDatabaseKey(key, password);
+		byte[] plaintext = crypto.decryptWithPassword(ciphertext, password);
+		if (plaintext == null) {
+			LOG.info("Failed to decrypt database key");
+			return null;
 		}
-		return key;
+		return new SecretKey(plaintext);
 	}
 
 	@Override
-	public void changePassword(String oldPassword, String newPassword)
-			throws DecryptionException {
+	public boolean changePassword(String oldPassword, String newPassword) {
 		synchronized (stateChangeLock) {
 			SecretKey key = loadAndDecryptDatabaseKey(oldPassword);
-			encryptAndStoreDatabaseKey(key, newPassword);
+			return key != null && encryptAndStoreDatabaseKey(key, newPassword);
 		}
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/connection/Connection.java

@@ -1,79 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
-import static org.briarproject.bramble.util.IoUtils.read;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-abstract class Connection {
-
-	protected static final Logger LOG = getLogger(Connection.class.getName());
-
-	final KeyManager keyManager;
-	final ConnectionRegistry connectionRegistry;
-	final StreamReaderFactory streamReaderFactory;
-	final StreamWriterFactory streamWriterFactory;
-
-	Connection(KeyManager keyManager, ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory) {
-		this.keyManager = keyManager;
-		this.connectionRegistry = connectionRegistry;
-		this.streamReaderFactory = streamReaderFactory;
-		this.streamWriterFactory = streamWriterFactory;
-	}
-
-	@Nullable
-	StreamContext recogniseTag(TransportConnectionReader reader,
-			TransportId transportId) {
-		StreamContext ctx;
-		try {
-			byte[] tag = readTag(reader.getInputStream());
-			return keyManager.getStreamContext(transportId, tag);
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			return null;
-		}
-	}
-
-	private byte[] readTag(InputStream in) throws IOException {
-		byte[] tag = new byte[TAG_LENGTH];
-		read(in, tag);
-		return tag;
-	}
-
-	void disposeOnError(TransportConnectionReader reader, boolean recognised) {
-		try {
-			reader.dispose(true, recognised);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	void disposeOnError(TransportConnectionWriter writer) {
-		try {
-			writer.dispose(true);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-}

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

@@ -1,114 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactExchangeManager;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.HandshakeManager;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.security.SecureRandom;
-import java.util.concurrent.Executor;
-
-import javax.annotation.concurrent.Immutable;
-import javax.inject.Inject;
-
-@Immutable
-@NotNullByDefault
-class ConnectionManagerImpl implements ConnectionManager {
-
-	private final Executor ioExecutor;
-	private final KeyManager keyManager;
-	private final StreamReaderFactory streamReaderFactory;
-	private final StreamWriterFactory streamWriterFactory;
-	private final SyncSessionFactory syncSessionFactory;
-	private final HandshakeManager handshakeManager;
-	private final ContactExchangeManager contactExchangeManager;
-	private final ConnectionRegistry connectionRegistry;
-	private final TransportPropertyManager transportPropertyManager;
-	private final SecureRandom secureRandom;
-
-	@Inject
-	ConnectionManagerImpl(@IoExecutor Executor ioExecutor,
-			KeyManager keyManager, StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			HandshakeManager handshakeManager,
-			ContactExchangeManager contactExchangeManager,
-			ConnectionRegistry connectionRegistry,
-			TransportPropertyManager transportPropertyManager,
-			SecureRandom secureRandom) {
-		this.ioExecutor = ioExecutor;
-		this.keyManager = keyManager;
-		this.streamReaderFactory = streamReaderFactory;
-		this.streamWriterFactory = streamWriterFactory;
-		this.syncSessionFactory = syncSessionFactory;
-		this.handshakeManager = handshakeManager;
-		this.contactExchangeManager = contactExchangeManager;
-		this.connectionRegistry = connectionRegistry;
-		this.transportPropertyManager = transportPropertyManager;
-		this.secureRandom = secureRandom;
-	}
-
-
-	@Override
-	public void manageIncomingConnection(TransportId t,
-			TransportConnectionReader r) {
-		ioExecutor.execute(new IncomingSimplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, t, r));
-	}
-
-	@Override
-	public void manageIncomingConnection(TransportId t,
-			DuplexTransportConnection d) {
-		ioExecutor.execute(new IncomingDuplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, ioExecutor,
-				t, d));
-	}
-
-	@Override
-	public void manageIncomingConnection(PendingContactId p, TransportId t,
-			DuplexTransportConnection d) {
-		ioExecutor.execute(new IncomingHandshakeConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				handshakeManager, contactExchangeManager, this, p, t, d));
-	}
-
-	@Override
-	public void manageOutgoingConnection(ContactId c, TransportId t,
-			TransportConnectionWriter w) {
-		ioExecutor.execute(new OutgoingSimplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, c, t, w));
-	}
-
-	@Override
-	public void manageOutgoingConnection(ContactId c, TransportId t,
-			DuplexTransportConnection d) {
-		ioExecutor.execute(new OutgoingDuplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, ioExecutor,
-				secureRandom, c, t, d));
-	}
-
-	@Override
-	public void manageOutgoingConnection(PendingContactId p, TransportId t,
-			DuplexTransportConnection d) {
-		ioExecutor.execute(new OutgoingHandshakeConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				handshakeManager, contactExchangeManager, this, p, t, d));
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/ConnectionModule.java

@@ -1,26 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-
-import javax.inject.Singleton;
-
-import dagger.Module;
-import dagger.Provides;
-
-@Module
-public class ConnectionModule {
-
-	@Provides
-	ConnectionManager provideConnectionManager(
-			ConnectionManagerImpl connectionManager) {
-		return connectionManager;
-	}
-
-	@Provides
-	@Singleton
-	ConnectionRegistry provideConnectionRegistry(
-			ConnectionRegistryImpl connectionRegistry) {
-		return connectionRegistry;
-	}
-}

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

@@ -1,270 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.Bytes;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.connection.InterruptibleConnection;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.PluginConfig;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
-import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
-import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
-import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionClosedEvent;
-import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionOpenedEvent;
-import org.briarproject.bramble.api.sync.Priority;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.Set;
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-import javax.inject.Inject;
-
-import static java.util.Collections.emptyList;
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Logger.getLogger;
-
-@ThreadSafe
-@NotNullByDefault
-class ConnectionRegistryImpl implements ConnectionRegistry {
-
-	private static final Logger LOG =
-			getLogger(ConnectionRegistryImpl.class.getName());
-
-	private final EventBus eventBus;
-	private final Map<TransportId, List<TransportId>> transportPrefs;
-
-	private final Object lock = new Object();
-	@GuardedBy("lock")
-	private final Map<ContactId, List<ConnectionRecord>> contactConnections;
-	@GuardedBy("lock")
-	private final Set<PendingContactId> connectedPendingContacts;
-
-	@Inject
-	ConnectionRegistryImpl(EventBus eventBus, PluginConfig pluginConfig) {
-		this.eventBus = eventBus;
-		transportPrefs = pluginConfig.getTransportPreferences();
-		contactConnections = new HashMap<>();
-		connectedPendingContacts = new HashSet<>();
-	}
-
-	@Override
-	public void registerConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn, boolean incoming) {
-		if (LOG.isLoggable(INFO)) {
-			if (incoming) LOG.info("Incoming connection registered: " + t);
-			else LOG.info("Outgoing connection registered: " + t);
-		}
-		boolean firstConnection;
-		synchronized (lock) {
-			List<ConnectionRecord> recs = contactConnections.get(c);
-			if (recs == null) {
-				recs = new ArrayList<>();
-				contactConnections.put(c, recs);
-			}
-			firstConnection = recs.isEmpty();
-			recs.add(new ConnectionRecord(t, conn));
-		}
-		eventBus.broadcast(new ConnectionOpenedEvent(c, t, incoming));
-		if (firstConnection) {
-			LOG.info("Contact connected");
-			eventBus.broadcast(new ContactConnectedEvent(c));
-		}
-	}
-
-	@Override
-	public void setPriority(ContactId c, TransportId t,
-			InterruptibleConnection conn, Priority priority) {
-		if (LOG.isLoggable(INFO)) LOG.info("Setting connection priority: " + t);
-		List<InterruptibleConnection> toInterrupt;
-		boolean interruptNewConnection = false;
-		synchronized (lock) {
-			List<ConnectionRecord> recs = contactConnections.get(c);
-			if (recs == null) throw new IllegalArgumentException();
-			toInterrupt = new ArrayList<>(recs.size());
-			for (ConnectionRecord rec : recs) {
-				if (rec.conn == conn) {
-					// Store the priority of this connection
-					rec.priority = priority;
-				} else if (rec.priority != null) {
-					int compare = compareConnections(t, priority,
-							rec.transportId, rec.priority);
-					if (compare == -1) {
-						// The old connection is better than the new one
-						interruptNewConnection = true;
-					} else if (compare == 1 && !rec.interrupted) {
-						// The new connection is better than the old one
-						toInterrupt.add(rec.conn);
-						rec.interrupted = true;
-					}
-				}
-			}
-		}
-		if (interruptNewConnection) {
-			LOG.info("Interrupting new connection");
-			conn.interruptOutgoingSession();
-		}
-		for (InterruptibleConnection old : toInterrupt) {
-			LOG.info("Interrupting old connection");
-			old.interruptOutgoingSession();
-		}
-	}
-
-	private int compareConnections(TransportId tA, Priority pA, TransportId tB,
-			Priority pB) {
-		if (getBetterTransports(tA).contains(tB)) return -1;
-		if (getBetterTransports(tB).contains(tA)) return 1;
-		return tA.equals(tB) ? Bytes.compare(pA.getNonce(), pB.getNonce()) : 0;
-	}
-
-	private List<TransportId> getBetterTransports(TransportId t) {
-		List<TransportId> better = transportPrefs.get(t);
-		return better == null ? emptyList() : better;
-	}
-
-	@Override
-	public void unregisterConnection(ContactId c, TransportId t,
-			InterruptibleConnection conn, boolean incoming, boolean exception) {
-		if (LOG.isLoggable(INFO)) {
-			if (incoming) LOG.info("Incoming connection unregistered: " + t);
-			else LOG.info("Outgoing connection unregistered: " + t);
-		}
-		boolean lastConnection;
-		synchronized (lock) {
-			List<ConnectionRecord> recs = contactConnections.get(c);
-			if (recs == null || !recs.remove(new ConnectionRecord(t, conn)))
-				throw new IllegalArgumentException();
-			lastConnection = recs.isEmpty();
-		}
-		eventBus.broadcast(
-				new ConnectionClosedEvent(c, t, incoming, exception));
-		if (lastConnection) {
-			LOG.info("Contact disconnected");
-			eventBus.broadcast(new ContactDisconnectedEvent(c));
-		}
-	}
-
-	@Override
-	public Collection<ContactId> getConnectedContacts(TransportId t) {
-		synchronized (lock) {
-			List<ContactId> contactIds = new ArrayList<>();
-			for (Entry<ContactId, List<ConnectionRecord>> e :
-					contactConnections.entrySet()) {
-				for (ConnectionRecord rec : e.getValue()) {
-					if (rec.transportId.equals(t)) {
-						contactIds.add(e.getKey());
-						break;
-					}
-				}
-			}
-			if (LOG.isLoggable(INFO)) {
-				LOG.info(contactIds.size() + " contacts connected: " + t);
-			}
-			return contactIds;
-		}
-	}
-
-	@Override
-	public Collection<ContactId> getConnectedOrBetterContacts(TransportId t) {
-		synchronized (lock) {
-			List<TransportId> better = getBetterTransports(t);
-			List<ContactId> contactIds = new ArrayList<>();
-			for (Entry<ContactId, List<ConnectionRecord>> e :
-					contactConnections.entrySet()) {
-				for (ConnectionRecord rec : e.getValue()) {
-					if (rec.transportId.equals(t) ||
-							better.contains(rec.transportId)) {
-						contactIds.add(e.getKey());
-						break;
-					}
-				}
-			}
-			if (LOG.isLoggable(INFO)) {
-				LOG.info(contactIds.size()
-						+ " contacts connected or better: " + t);
-			}
-			return contactIds;
-		}
-	}
-
-	@Override
-	public boolean isConnected(ContactId c, TransportId t) {
-		synchronized (lock) {
-			List<ConnectionRecord> recs = contactConnections.get(c);
-			if (recs == null) return false;
-			for (ConnectionRecord rec : recs) {
-				if (rec.transportId.equals(t)) return true;
-			}
-			return false;
-		}
-	}
-
-	@Override
-	public boolean isConnected(ContactId c) {
-		synchronized (lock) {
-			return contactConnections.containsKey(c);
-		}
-	}
-
-	@Override
-	public boolean registerConnection(PendingContactId p) {
-		boolean added;
-		synchronized (lock) {
-			added = connectedPendingContacts.add(p);
-		}
-		if (added) eventBus.broadcast(new RendezvousConnectionOpenedEvent(p));
-		return added;
-	}
-
-	@Override
-	public void unregisterConnection(PendingContactId p, boolean success) {
-		synchronized (lock) {
-			if (!connectedPendingContacts.remove(p))
-				throw new IllegalArgumentException();
-		}
-		eventBus.broadcast(new RendezvousConnectionClosedEvent(p, success));
-	}
-
-	private static class ConnectionRecord {
-
-		private final TransportId transportId;
-		private final InterruptibleConnection conn;
-		@GuardedBy("lock")
-		@Nullable
-		private Priority priority = null;
-		@GuardedBy("lock")
-		private boolean interrupted = false;
-
-		private ConnectionRecord(TransportId transportId,
-				InterruptibleConnection conn) {
-			this.transportId = transportId;
-			this.conn = conn;
-		}
-
-		@Override
-		public boolean equals(Object o) {
-			if (o instanceof ConnectionRecord) {
-				return conn == ((ConnectionRecord) o).conn;
-			} else {
-				return false;
-			}
-		}
-
-		@Override
-		public int hashCode() {
-			return conn.hashCode();
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/DuplexSyncConnection.java

@@ -1,104 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.connection.InterruptibleConnection;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportProperties;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.Priority;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.util.concurrent.Executor;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-
-@NotNullByDefault
-abstract class DuplexSyncConnection extends SyncConnection
-		implements InterruptibleConnection {
-
-	final Executor ioExecutor;
-	final TransportId transportId;
-	final TransportConnectionReader reader;
-	final TransportConnectionWriter writer;
-	final TransportProperties remote;
-
-	private final Object interruptLock = new Object();
-
-	@GuardedBy("interruptLock")
-	@Nullable
-	private SyncSession outgoingSession = null;
-	@GuardedBy("interruptLock")
-	private boolean interruptWaiting = false;
-
-	@Override
-	public void interruptOutgoingSession() {
-		synchronized (interruptLock) {
-			if (outgoingSession == null) interruptWaiting = true;
-			else outgoingSession.interrupt();
-		}
-	}
-
-	void setOutgoingSession(SyncSession outgoingSession) {
-		synchronized (interruptLock) {
-			this.outgoingSession = outgoingSession;
-			if (interruptWaiting) {
-				outgoingSession.interrupt();
-				interruptWaiting = false;
-			}
-		}
-	}
-
-	DuplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			Executor ioExecutor, TransportId transportId,
-			DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager);
-		this.ioExecutor = ioExecutor;
-		this.transportId = transportId;
-		reader = connection.getReader();
-		writer = connection.getWriter();
-		remote = connection.getRemoteProperties();
-	}
-
-	void onReadError(boolean recognised) {
-		disposeOnError(reader, recognised);
-		disposeOnError(writer);
-		interruptOutgoingSession();
-	}
-
-	void onWriteError() {
-		disposeOnError(reader, true);
-		disposeOnError(writer);
-	}
-
-	SyncSession createDuplexOutgoingSession(StreamContext ctx,
-			TransportConnectionWriter w, @Nullable Priority priority)
-			throws IOException {
-		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
-				w.getOutputStream(), ctx);
-		ContactId c = requireNonNull(ctx.getContactId());
-		return syncSessionFactory.createDuplexOutgoingSession(c,
-				w.getMaxLatency(), w.getMaxIdleTime(), streamWriter, priority);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/HandshakeConnection.java

@@ -1,72 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactExchangeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import javax.annotation.Nullable;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-abstract class HandshakeConnection extends Connection {
-
-	final HandshakeManager handshakeManager;
-	final ContactExchangeManager contactExchangeManager;
-	final ConnectionManager connectionManager;
-	final PendingContactId pendingContactId;
-	final TransportId transportId;
-	final DuplexTransportConnection connection;
-	final TransportConnectionReader reader;
-	final TransportConnectionWriter writer;
-
-	HandshakeConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			HandshakeManager handshakeManager,
-			ContactExchangeManager contactExchangeManager,
-			ConnectionManager connectionManager,
-			PendingContactId pendingContactId,
-			TransportId transportId, DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory);
-		this.handshakeManager = handshakeManager;
-		this.contactExchangeManager = contactExchangeManager;
-		this.connectionManager = connectionManager;
-		this.pendingContactId = pendingContactId;
-		this.transportId = transportId;
-		this.connection = connection;
-		reader = connection.getReader();
-		writer = connection.getWriter();
-	}
-
-	@Nullable
-	StreamContext allocateStreamContext(PendingContactId pendingContactId,
-			TransportId transportId) {
-		try {
-			return keyManager.getStreamContext(pendingContactId, transportId);
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-			return null;
-		}
-	}
-
-	void onError(boolean recognised) {
-		disposeOnError(reader, recognised);
-		disposeOnError(writer);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/IncomingDuplexSyncConnection.java

@@ -1,107 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.PriorityHandler;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.util.concurrent.Executor;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class IncomingDuplexSyncConnection extends DuplexSyncConnection
-		implements Runnable {
-
-	IncomingDuplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			Executor ioExecutor, TransportId transportId,
-			DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager, ioExecutor, transportId, connection);
-	}
-
-	@Override
-	public void run() {
-		// Read and recognise the tag
-		StreamContext ctx = recogniseTag(reader, transportId);
-		if (ctx == null) {
-			LOG.info("Unrecognised tag");
-			onReadError(false);
-			return;
-		}
-		ContactId contactId = ctx.getContactId();
-		if (contactId == null) {
-			LOG.warning("Expected contact tag, got rendezvous tag");
-			onReadError(true);
-			return;
-		}
-		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Received handshake tag, expected rotation mode");
-			onReadError(true);
-			return;
-		}
-		connectionRegistry.registerConnection(contactId, transportId,
-				this, true);
-		// Start the outgoing session on another thread
-		ioExecutor.execute(() -> runOutgoingSession(contactId));
-		try {
-			// Store any transport properties discovered from the connection
-			transportPropertyManager.addRemotePropertiesFromConnection(
-					contactId, transportId, remote);
-			// Update the connection registry when we receive our priority
-			PriorityHandler handler = p -> connectionRegistry.setPriority(
-					contactId, transportId, this, p);
-			// Create and run the incoming session
-			createIncomingSession(ctx, reader, handler).run();
-			reader.dispose(false, true);
-			interruptOutgoingSession();
-			connectionRegistry.unregisterConnection(contactId, transportId,
-					this, true, false);
-		} catch (DbException | IOException e) {
-			logException(LOG, WARNING, e);
-			onReadError(true);
-			connectionRegistry.unregisterConnection(contactId, transportId,
-					this, true, true);
-		}
-	}
-
-	private void runOutgoingSession(ContactId contactId) {
-		// Allocate a stream context
-		StreamContext ctx = allocateStreamContext(contactId, transportId);
-		if (ctx == null) {
-			LOG.warning("Could not allocate stream context");
-			onWriteError();
-			return;
-		}
-		try {
-			// Create and run the outgoing session
-			SyncSession out = createDuplexOutgoingSession(ctx, writer, null);
-			setOutgoingSession(out);
-			out.run();
-			writer.dispose(false);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onWriteError();
-		}
-	}
-}
-

bramble-core/src/main/java/org/briarproject/bramble/connection/IncomingHandshakeConnection.java

@@ -1,93 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactExchangeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager.HandshakeResult;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class IncomingHandshakeConnection extends HandshakeConnection
-		implements Runnable {
-
-	IncomingHandshakeConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			HandshakeManager handshakeManager,
-			ContactExchangeManager contactExchangeManager,
-			ConnectionManager connectionManager,
-			PendingContactId pendingContactId,
-			TransportId transportId, DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, handshakeManager, contactExchangeManager,
-				connectionManager, pendingContactId, transportId, connection);
-	}
-
-	@Override
-	public void run() {
-		// Read and recognise the tag
-		StreamContext ctxIn = recogniseTag(reader, transportId);
-		if (ctxIn == null) {
-			LOG.info("Unrecognised tag");
-			onError(false);
-			return;
-		}
-		PendingContactId inPendingContactId = ctxIn.getPendingContactId();
-		if (inPendingContactId == null) {
-			LOG.warning("Expected rendezvous tag, got contact tag");
-			onError(true);
-			return;
-		}
-		// Allocate the outgoing stream context
-		StreamContext ctxOut =
-				allocateStreamContext(pendingContactId, transportId);
-		if (ctxOut == null) {
-			LOG.warning("Could not allocate stream context");
-			onError(true);
-			return;
-		}
-		// Close the connection if it's redundant
-		if (!connectionRegistry.registerConnection(pendingContactId)) {
-			LOG.info("Redundant rendezvous connection");
-			onError(true);
-			return;
-		}
-		// Handshake and exchange contacts
-		try {
-			InputStream in = streamReaderFactory.createStreamReader(
-					reader.getInputStream(), ctxIn);
-			// Flush the output stream to send the outgoing stream header
-			StreamWriter out = streamWriterFactory.createStreamWriter(
-					writer.getOutputStream(), ctxOut);
-			out.getOutputStream().flush();
-			HandshakeResult result =
-					handshakeManager.handshake(pendingContactId, in, out);
-			contactExchangeManager.exchangeContacts(pendingContactId,
-					connection, result.getMasterKey(), result.isAlice(), false);
-			connectionRegistry.unregisterConnection(pendingContactId, true);
-			// Reuse the connection as a transport connection
-			connectionManager.manageIncomingConnection(transportId, connection);
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			onError(true);
-			connectionRegistry.unregisterConnection(pendingContactId, false);
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/IncomingSimplexSyncConnection.java

@@ -1,79 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.PriorityHandler;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class IncomingSimplexSyncConnection extends SyncConnection implements Runnable {
-
-	private final TransportId transportId;
-	private final TransportConnectionReader reader;
-
-	IncomingSimplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			TransportId transportId, TransportConnectionReader reader) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager);
-		this.transportId = transportId;
-		this.reader = reader;
-	}
-
-	@Override
-	public void run() {
-		// Read and recognise the tag
-		StreamContext ctx = recogniseTag(reader, transportId);
-		if (ctx == null) {
-			LOG.info("Unrecognised tag");
-			onError(false);
-			return;
-		}
-		ContactId contactId = ctx.getContactId();
-		if (contactId == null) {
-			LOG.warning("Received rendezvous stream, expected contact");
-			onError(true);
-			return;
-		}
-		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Received handshake tag, expected rotation mode");
-			onError(true);
-			return;
-		}
-		try {
-			// We don't expect to receive a priority for this connection
-			PriorityHandler handler = p ->
-					LOG.info("Ignoring priority for simplex connection");
-			// Create and run the incoming session
-			createIncomingSession(ctx, reader, handler).run();
-			reader.dispose(false, true);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onError(true);
-		}
-	}
-
-	private void onError(boolean recognised) {
-		disposeOnError(reader, recognised);
-	}
-}
-

bramble-core/src/main/java/org/briarproject/bramble/connection/OutgoingDuplexSyncConnection.java

@@ -1,141 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.Priority;
-import org.briarproject.bramble.api.sync.PriorityHandler;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.security.SecureRandom;
-import java.util.concurrent.Executor;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.sync.SyncConstants.PRIORITY_NONCE_BYTES;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class OutgoingDuplexSyncConnection extends DuplexSyncConnection
-		implements Runnable {
-
-	private final SecureRandom secureRandom;
-	private final ContactId contactId;
-
-	OutgoingDuplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			Executor ioExecutor, SecureRandom secureRandom, ContactId contactId,
-			TransportId transportId, DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager, ioExecutor, transportId, connection);
-		this.secureRandom = secureRandom;
-		this.contactId = contactId;
-	}
-
-	@Override
-	public void run() {
-		// Allocate a stream context
-		StreamContext ctx = allocateStreamContext(contactId, transportId);
-		if (ctx == null) {
-			LOG.warning("Could not allocate stream context");
-			onWriteError();
-			return;
-		}
-		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Cannot use handshake mode stream context");
-			onWriteError();
-			return;
-		}
-		// Start the incoming session on another thread
-		Priority priority = generatePriority();
-		ioExecutor.execute(() -> runIncomingSession(priority));
-		try {
-			// Create and run the outgoing session
-			SyncSession out =
-					createDuplexOutgoingSession(ctx, writer, priority);
-			setOutgoingSession(out);
-			out.run();
-			writer.dispose(false);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onWriteError();
-		}
-	}
-
-	private void runIncomingSession(Priority priority) {
-		// Read and recognise the tag
-		StreamContext ctx = recogniseTag(reader, transportId);
-		// Unrecognised tags are suspicious in this case
-		if (ctx == null) {
-			LOG.warning("Unrecognised tag for returning stream");
-			onReadError();
-			return;
-		}
-		// Check that the stream comes from the expected contact
-		ContactId inContactId = ctx.getContactId();
-		if (inContactId == null) {
-			LOG.warning("Expected contact tag, got rendezvous tag");
-			onReadError();
-			return;
-		}
-		if (!contactId.equals(inContactId)) {
-			LOG.warning("Wrong contact ID for returning stream");
-			onReadError();
-			return;
-		}
-		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Received handshake tag, expected rotation mode");
-			onReadError();
-			return;
-		}
-		connectionRegistry.registerConnection(contactId, transportId,
-				this, false);
-		connectionRegistry.setPriority(contactId, transportId, this, priority);
-		try {
-			// Store any transport properties discovered from the connection
-			transportPropertyManager.addRemotePropertiesFromConnection(
-					contactId, transportId, remote);
-			// We don't expect to receive a priority for this connection
-			PriorityHandler handler = p ->
-					LOG.info("Ignoring priority for outgoing connection");
-			// Create and run the incoming session
-			createIncomingSession(ctx, reader, handler).run();
-			reader.dispose(false, true);
-			interruptOutgoingSession();
-			connectionRegistry.unregisterConnection(contactId, transportId,
-					this, false, false);
-		} catch (DbException | IOException e) {
-			logException(LOG, WARNING, e);
-			onReadError();
-			connectionRegistry.unregisterConnection(contactId, transportId,
-					this, false, true);
-		}
-	}
-
-	private void onReadError() {
-		// 'Recognised' is always true for outgoing connections
-		onReadError(true);
-	}
-
-	private Priority generatePriority() {
-		byte[] nonce = new byte[PRIORITY_NONCE_BYTES];
-		secureRandom.nextBytes(nonce);
-		return new Priority(nonce);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/OutgoingHandshakeConnection.java

@@ -1,115 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.Contact;
-import org.briarproject.bramble.api.contact.ContactExchangeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager;
-import org.briarproject.bramble.api.contact.HandshakeManager.HandshakeResult;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class OutgoingHandshakeConnection extends HandshakeConnection
-		implements Runnable {
-
-	OutgoingHandshakeConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			HandshakeManager handshakeManager,
-			ContactExchangeManager contactExchangeManager,
-			ConnectionManager connectionManager,
-			PendingContactId pendingContactId,
-			TransportId transportId, DuplexTransportConnection connection) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, handshakeManager, contactExchangeManager,
-				connectionManager, pendingContactId, transportId, connection);
-	}
-
-	@Override
-	public void run() {
-		// Allocate the outgoing stream context
-		StreamContext ctxOut =
-				allocateStreamContext(pendingContactId, transportId);
-		if (ctxOut == null) {
-			LOG.warning("Could not allocate stream context");
-			onError();
-			return;
-		}
-		// Flush the output stream to send the outgoing stream header
-		StreamWriter out;
-		try {
-			out = streamWriterFactory.createStreamWriter(
-					writer.getOutputStream(), ctxOut);
-			out.getOutputStream().flush();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onError();
-			return;
-		}
-		// Read and recognise the tag
-		StreamContext ctxIn = recogniseTag(reader, transportId);
-		// Unrecognised tags are suspicious in this case
-		if (ctxIn == null) {
-			LOG.warning("Unrecognised tag for returning stream");
-			onError();
-			return;
-		}
-		// Check that the stream comes from the expected pending contact
-		PendingContactId inPendingContactId = ctxIn.getPendingContactId();
-		if (inPendingContactId == null) {
-			LOG.warning("Expected rendezvous tag, got contact tag");
-			onError();
-			return;
-		}
-		if (!inPendingContactId.equals(pendingContactId)) {
-			LOG.warning("Wrong pending contact ID for returning stream");
-			onError();
-			return;
-		}
-		// Close the connection if it's redundant
-		if (!connectionRegistry.registerConnection(pendingContactId)) {
-			LOG.info("Redundant rendezvous connection");
-			onError();
-			return;
-		}
-		// Handshake and exchange contacts
-		try {
-			InputStream in = streamReaderFactory.createStreamReader(
-					reader.getInputStream(), ctxIn);
-			HandshakeResult result =
-					handshakeManager.handshake(pendingContactId, in, out);
-			Contact contact = contactExchangeManager.exchangeContacts(
-					pendingContactId, connection, result.getMasterKey(),
-					result.isAlice(), false);
-			connectionRegistry.unregisterConnection(pendingContactId, true);
-			// Reuse the connection as a transport connection
-			connectionManager.manageOutgoingConnection(contact.getId(),
-					transportId, connection);
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			onError();
-			connectionRegistry.unregisterConnection(pendingContactId, false);
-		}
-	}
-
-	private void onError() {
-		// 'Recognised' is always true for outgoing connections
-		onError(true);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/connection/OutgoingSimplexSyncConnection.java

@@ -1,78 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
-
-	private final ContactId contactId;
-	private final TransportId transportId;
-	private final TransportConnectionWriter writer;
-
-	OutgoingSimplexSyncConnection(KeyManager keyManager,
-			ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager,
-			ContactId contactId, TransportId transportId,
-			TransportConnectionWriter writer) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory, syncSessionFactory,
-				transportPropertyManager);
-		this.contactId = contactId;
-		this.transportId = transportId;
-		this.writer = writer;
-	}
-
-	@Override
-	public void run() {
-		// Allocate a stream context
-		StreamContext ctx = allocateStreamContext(contactId, transportId);
-		if (ctx == null) {
-			LOG.warning("Could not allocate stream context");
-			onError();
-			return;
-		}
-		try {
-			// Create and run the outgoing session
-			createSimplexOutgoingSession(ctx, writer).run();
-			writer.dispose(false);
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onError();
-		}
-	}
-
-	private void onError() {
-		disposeOnError(writer);
-	}
-
-	private SyncSession createSimplexOutgoingSession(StreamContext ctx,
-			TransportConnectionWriter w) throws IOException {
-		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
-				w.getOutputStream(), ctx);
-		ContactId c = requireNonNull(ctx.getContactId());
-		return syncSessionFactory.createSimplexOutgoingSession(c,
-				w.getMaxLatency(), streamWriter);
-	}
-}
-

bramble-core/src/main/java/org/briarproject/bramble/connection/SyncConnection.java

@@ -1,64 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.TransportConnectionReader;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.PriorityHandler;
-import org.briarproject.bramble.api.sync.SyncSession;
-import org.briarproject.bramble.api.sync.SyncSessionFactory;
-import org.briarproject.bramble.api.transport.KeyManager;
-import org.briarproject.bramble.api.transport.StreamContext;
-import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriterFactory;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-import javax.annotation.Nullable;
-
-import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@NotNullByDefault
-class SyncConnection extends Connection {
-
-	final SyncSessionFactory syncSessionFactory;
-	final TransportPropertyManager transportPropertyManager;
-
-	SyncConnection(KeyManager keyManager, ConnectionRegistry connectionRegistry,
-			StreamReaderFactory streamReaderFactory,
-			StreamWriterFactory streamWriterFactory,
-			SyncSessionFactory syncSessionFactory,
-			TransportPropertyManager transportPropertyManager) {
-		super(keyManager, connectionRegistry, streamReaderFactory,
-				streamWriterFactory);
-		this.syncSessionFactory = syncSessionFactory;
-		this.transportPropertyManager = transportPropertyManager;
-	}
-
-	@Nullable
-	StreamContext allocateStreamContext(ContactId contactId,
-			TransportId transportId) {
-		try {
-			return keyManager.getStreamContext(contactId, transportId);
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-			return null;
-		}
-	}
-
-	SyncSession createIncomingSession(StreamContext ctx,
-			TransportConnectionReader r, PriorityHandler handler)
-			throws IOException {
-		InputStream streamReader = streamReaderFactory.createStreamReader(
-				r.getInputStream(), ctx);
-		ContactId c = requireNonNull(ctx.getContactId());
-		return syncSessionFactory
-				.createIncomingSession(c, streamReader, handler);
-	}
-}

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

@@ -139,8 +139,7 @@ class ContactManagerImpl implements ContactManager, EventListener {
 				pendingContactFactory.createPendingContact(link, alias);
 		Transaction txn = db.startTransaction(false);
 		try {
-			AuthorId local = identityManager.getLocalAuthor(txn).getId();
-			db.addPendingContact(txn, p, local);
+			db.addPendingContact(txn, p);
 			KeyPair ourKeyPair = identityManager.getHandshakeKeys(txn);
 			keyManager.addPendingContact(txn, p.getId(), p.getPublicKey(),
 					ourKeyPair);

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

@@ -7,10 +7,8 @@ import net.i2p.crypto.eddsa.KeyPairGenerator;
 import org.briarproject.bramble.api.crypto.AgreementPrivateKey;
 import org.briarproject.bramble.api.crypto.AgreementPublicKey;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.crypto.DecryptionException;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.KeyParser;
-import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
@@ -40,9 +38,6 @@ import static java.lang.System.arraycopy;
 import static java.util.logging.Level.INFO;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_AGREEMENT;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_SIGNATURE;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.INVALID_CIPHERTEXT;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.INVALID_PASSWORD;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.KEY_STRENGTHENER_ERROR;
 import static org.briarproject.bramble.util.ByteUtils.INT_32_BYTES;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -56,8 +51,7 @@ class CryptoComponentImpl implements CryptoComponent {
 	private static final int SIGNATURE_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 byte PBKDF_FORMAT_SCRYPT = 0;
-	private static final byte PBKDF_FORMAT_SCRYPT_STRENGTHENED = 1;
+	private static final int PBKDF_FORMAT_SCRYPT = 0;
 
 	private final SecureRandom secureRandom;
 	private final PasswordBasedKdf passwordBasedKdf;
@@ -317,8 +311,7 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public byte[] encryptWithPassword(byte[] input, String password,
-			@Nullable KeyStrengthener keyStrengthener) {
+	public byte[] encryptWithPassword(byte[] input, String password) {
 		AuthenticatedCipher cipher = new XSalsa20Poly1305AuthenticatedCipher();
 		int macBytes = cipher.getMacBytes();
 		// Generate a random salt
@@ -326,9 +319,8 @@ class CryptoComponentImpl implements CryptoComponent {
 		secureRandom.nextBytes(salt);
 		// Calibrate the KDF
 		int cost = passwordBasedKdf.chooseCostParameter();
-		// Derive the encryption key from the password
+		// Derive the key from the password
 		SecretKey key = passwordBasedKdf.deriveKey(password, salt, cost);
-		if (keyStrengthener != null) key = keyStrengthener.strengthenKey(key);
 		// Generate a random IV
 		byte[] iv = new byte[STORAGE_IV_BYTES];
 		secureRandom.nextBytes(iv);
@@ -339,9 +331,7 @@ class CryptoComponentImpl implements CryptoComponent {
 		byte[] output = new byte[outputLen];
 		int outputOff = 0;
 		// Format version
-		byte formatVersion = keyStrengthener == null
-				? PBKDF_FORMAT_SCRYPT : PBKDF_FORMAT_SCRYPT_STRENGTHENED;
-		output[outputOff] = formatVersion;
+		output[outputOff] = PBKDF_FORMAT_SCRYPT;
 		outputOff++;
 		// Salt
 		arraycopy(salt, 0, output, outputOff, salt.length);
@@ -363,26 +353,21 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public byte[] decryptWithPassword(byte[] input, String password,
-			@Nullable KeyStrengthener keyStrengthener)
-			throws DecryptionException {
+	@Nullable
+	public byte[] decryptWithPassword(byte[] input, String password) {
 		AuthenticatedCipher cipher = new XSalsa20Poly1305AuthenticatedCipher();
 		int macBytes = cipher.getMacBytes();
 		// The input contains the format version, salt, cost parameter, IV,
 		// ciphertext and MAC
 		if (input.length < 1 + PBKDF_SALT_BYTES + INT_32_BYTES
-				+ STORAGE_IV_BYTES + macBytes) {
-			throw new DecryptionException(INVALID_CIPHERTEXT);
-		}
+				+ STORAGE_IV_BYTES + macBytes)
+			return null; // Invalid input
 		int inputOff = 0;
 		// Format version
 		byte formatVersion = input[inputOff];
 		inputOff++;
-		// Check whether we support this format version
-		if (formatVersion != PBKDF_FORMAT_SCRYPT &&
-				formatVersion != PBKDF_FORMAT_SCRYPT_STRENGTHENED) {
-			throw new DecryptionException(INVALID_CIPHERTEXT);
-		}
+		if (formatVersion != PBKDF_FORMAT_SCRYPT)
+			return null; // Unknown format
 		// Salt
 		byte[] salt = new byte[PBKDF_SALT_BYTES];
 		arraycopy(input, inputOff, salt, 0, salt.length);
@@ -390,22 +375,14 @@ class CryptoComponentImpl implements CryptoComponent {
 		// Cost parameter
 		long cost = ByteUtils.readUint32(input, inputOff);
 		inputOff += INT_32_BYTES;
-		if (cost < 2 || cost > Integer.MAX_VALUE) {
-			throw new DecryptionException(INVALID_CIPHERTEXT);
-		}
+		if (cost < 2 || cost > Integer.MAX_VALUE)
+			return null; // Invalid cost parameter
 		// IV
 		byte[] iv = new byte[STORAGE_IV_BYTES];
 		arraycopy(input, inputOff, iv, 0, iv.length);
 		inputOff += iv.length;
-		// Derive the decryption key from the password
+		// Derive the key from the password
 		SecretKey key = passwordBasedKdf.deriveKey(password, salt, (int) cost);
-		if (formatVersion == PBKDF_FORMAT_SCRYPT_STRENGTHENED) {
-			if (keyStrengthener == null || !keyStrengthener.isInitialised()) {
-				// Can't derive the same strengthened key
-				throw new DecryptionException(KEY_STRENGTHENER_ERROR);
-			}
-			key = keyStrengthener.strengthenKey(key);
-		}
 		// Initialise the cipher
 		try {
 			cipher.init(false, key, iv);
@@ -419,16 +396,10 @@ class CryptoComponentImpl implements CryptoComponent {
 			cipher.process(input, inputOff, inputLen, output, 0);
 			return output;
 		} catch (GeneralSecurityException e) {
-			throw new DecryptionException(INVALID_PASSWORD);
+			return null; // Invalid ciphertext
 		}
 	}
 
-	@Override
-	public boolean isEncryptedWithStrengthenedKey(byte[] ciphertext) {
-		return ciphertext.length > 0 &&
-				ciphertext[0] == PBKDF_FORMAT_SCRYPT_STRENGTHENED;
-	}
-
 	@Override
 	public byte[] encryptToKey(PublicKey publicKey, byte[] plaintext) {
 		try {

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

@@ -267,16 +267,6 @@ interface Database<T> {
 	 */
 	Collection<ContactId> getContacts(T txn, AuthorId local) throws DbException;
 
-	/**
-	 * Returns the contact with the given {@code handshakePublicKey}
-	 * for the given local pseudonym or {@code null} if none exists.
-	 * <p/>
-	 * Read-only.
-	 */
-	@Nullable
-	Contact getContact(T txn, PublicKey handshakePublicKey, AuthorId local)
-			throws DbException;
-
 	/**
 	 * Returns the group with the given ID.
 	 * <p/>

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

@@ -291,17 +291,12 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public void addPendingContact(Transaction transaction, PendingContact p,
-			AuthorId local) throws DbException {
+	public void addPendingContact(Transaction transaction, PendingContact p)
+			throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
-		Contact contact = db.getContact(txn, p.getPublicKey(), local);
-		if (contact != null)
-			throw new ContactExistsException(local, contact.getAuthor());
-		if (db.containsPendingContact(txn, p.getId())) {
-			PendingContact existing = db.getPendingContact(txn, p.getId());
-			throw new PendingContactExistsException(existing);
-		}
+		if (db.containsPendingContact(txn, p.getId()))
+			throw new PendingContactExistsException();
 		db.addPendingContact(txn, p);
 		transaction.attach(new PendingContactAddedEvent(p));
 	}

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

@@ -25,7 +25,6 @@ import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
-import static org.briarproject.bramble.util.IoUtils.isNonEmptyDirectory;
 import static org.briarproject.bramble.util.LogUtils.logFileOrDir;
 
 /**
@@ -70,9 +69,8 @@ class H2Database extends JdbcDatabase {
 			LOG.info("Contents of account directory before opening DB:");
 			logFileOrDir(LOG, INFO, dir.getParentFile());
 		}
-		boolean reopen = isNonEmptyDirectory(dir);
+		boolean reopen = !dir.mkdirs();
 		if (LOG.isLoggable(INFO)) LOG.info("Reopening DB: " + reopen);
-		if (!reopen && dir.mkdirs()) LOG.info("Created database directory");
 		super.open("org.h2.Driver", reopen, key, listener);
 		if (LOG.isLoggable(INFO)) {
 			LOG.info("Contents of account directory after opening DB:");

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

@@ -20,11 +20,9 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
-import static org.briarproject.bramble.util.IoUtils.isNonEmptyDirectory;
 
 /**
  * Contains all the HSQLDB-specific code for the database.
@@ -66,10 +64,7 @@ class HyperSqlDatabase extends JdbcDatabase {
 	public boolean open(SecretKey key, @Nullable MigrationListener listener)
 			throws DbException {
 		this.key = key;
-		File dir = config.getDatabaseDirectory();
-		boolean reopen = isNonEmptyDirectory(dir);
-		if (LOG.isLoggable(INFO)) LOG.info("Reopening DB: " + reopen);
-		if (!reopen && dir.mkdirs()) LOG.info("Created database directory");
+		boolean reopen = !config.getDatabaseDirectory().mkdirs();
 		super.open("org.hsqldb.jdbc.JDBCDriver", reopen, key, listener);
 		return reopen;
 	}

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

@@ -1465,47 +1465,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Nullable
-	@Override
-	public Contact getContact(Connection txn, PublicKey handshakePublicKey,
-			AuthorId localAuthorId) throws DbException {
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			String sql = "SELECT contactId, authorId, formatVersion, name,"
-					+ " alias, publicKey, verified"
-					+ " FROM contacts"
-					+ " WHERE handshakePublicKey = ? AND localAuthorId = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setBytes(1, handshakePublicKey.getEncoded());
-			ps.setBytes(2, localAuthorId.getBytes());
-			rs = ps.executeQuery();
-			if (!rs.next()) {
-				rs.close();
-				ps.close();
-				return null;
-			}
-			ContactId contactId = new ContactId(rs.getInt(1));
-			AuthorId authorId = new AuthorId(rs.getBytes(2));
-			int formatVersion = rs.getInt(3);
-			String name = rs.getString(4);
-			String alias = rs.getString(5);
-			PublicKey publicKey = new SignaturePublicKey(rs.getBytes(6));
-			boolean verified = rs.getBoolean(7);
-			if (rs.next()) throw new DbStateException();
-			rs.close();
-			ps.close();
-			Author author =
-					new Author(authorId, formatVersion, name, publicKey);
-			return new Contact(contactId, author, localAuthorId, alias,
-					handshakePublicKey, verified);
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public Group getGroup(Connection txn, GroupId g) throws DbException {
 		PreparedStatement ps = null;

bramble-core/src/main/java/org/briarproject/bramble/io/IoModule.java

@@ -1,18 +0,0 @@
-package org.briarproject.bramble.io;
-
-import org.briarproject.bramble.api.io.TimeoutMonitor;
-
-import javax.inject.Singleton;
-
-import dagger.Module;
-import dagger.Provides;
-
-@Module
-public class IoModule {
-
-	@Provides
-	@Singleton
-	TimeoutMonitor provideTimeoutMonitor(TimeoutMonitorImpl timeoutMonitor) {
-		return timeoutMonitor;
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/io/TimeoutInputStream.java

@@ -1,104 +0,0 @@
-package org.briarproject.bramble.io;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.Clock;
-
-import java.io.IOException;
-import java.io.InputStream;
-
-import javax.annotation.concurrent.GuardedBy;
-
-@NotNullByDefault
-class TimeoutInputStream extends InputStream {
-
-	private final Clock clock;
-	private final InputStream in;
-	private final long timeoutMs;
-	private final CloseListener listener;
-	private final Object lock = new Object();
-	@GuardedBy("lock")
-	private long readStartedMs = -1;
-
-	TimeoutInputStream(Clock clock, InputStream in, long timeoutMs,
-			CloseListener listener) {
-		this.clock = clock;
-		this.in = in;
-		this.timeoutMs = timeoutMs;
-		this.listener = listener;
-	}
-
-	@Override
-	public int read() throws IOException {
-		synchronized (lock) {
-			readStartedMs = clock.currentTimeMillis();
-		}
-		int input = in.read();
-		synchronized (lock) {
-			readStartedMs = -1;
-		}
-		return input;
-	}
-
-	@Override
-	public int read(byte[] b) throws IOException {
-		return read(b, 0, b.length);
-	}
-
-	@Override
-	public int read(byte[] b, int off, int len) throws IOException {
-		synchronized (lock) {
-			readStartedMs = clock.currentTimeMillis();
-		}
-		int read = in.read(b, off, len);
-		synchronized (lock) {
-			readStartedMs = -1;
-		}
-		return read;
-	}
-
-	@Override
-	public void close() throws IOException {
-		try {
-			in.close();
-		} finally {
-			listener.onClose(this);
-		}
-	}
-
-	@Override
-	public int available() throws IOException {
-		return in.available();
-	}
-
-	@Override
-	public void mark(int readlimit) {
-		in.mark(readlimit);
-	}
-
-	@Override
-	public boolean markSupported() {
-		return in.markSupported();
-	}
-
-	@Override
-	public void reset() throws IOException {
-		in.reset();
-	}
-
-	@Override
-	public long skip(long n) throws IOException {
-		return in.skip(n);
-	}
-
-	boolean hasTimedOut() {
-		synchronized (lock) {
-			return readStartedMs != -1 &&
-					clock.currentTimeMillis() - readStartedMs > timeoutMs;
-		}
-	}
-
-	interface CloseListener {
-
-		void onClose(TimeoutInputStream closed);
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/io/TimeoutMonitorImpl.java

@@ -1,96 +0,0 @@
-package org.briarproject.bramble.io;
-
-import org.briarproject.bramble.api.io.TimeoutMonitor;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.Scheduler;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.List;
-import java.util.concurrent.Executor;
-import java.util.concurrent.Future;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.logging.Logger;
-
-import javax.annotation.concurrent.GuardedBy;
-import javax.inject.Inject;
-
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static java.util.concurrent.TimeUnit.SECONDS;
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-class TimeoutMonitorImpl implements TimeoutMonitor {
-
-	private static final Logger LOG =
-			getLogger(TimeoutMonitorImpl.class.getName());
-
-	private static final long CHECK_INTERVAL_MS = SECONDS.toMillis(10);
-
-	private final ScheduledExecutorService scheduler;
-	private final Executor ioExecutor;
-	private final Clock clock;
-	private final Object lock = new Object();
-	@GuardedBy("lock")
-	private final List<TimeoutInputStream> streams = new ArrayList<>();
-
-	@GuardedBy("lock")
-	private Future<?> task = null;
-
-	@Inject
-	TimeoutMonitorImpl(@Scheduler ScheduledExecutorService scheduler,
-			@IoExecutor Executor ioExecutor, Clock clock) {
-		this.scheduler = scheduler;
-		this.ioExecutor = ioExecutor;
-		this.clock = clock;
-	}
-
-	@Override
-	public InputStream createTimeoutInputStream(InputStream in,
-			long timeoutMs) {
-		TimeoutInputStream stream = new TimeoutInputStream(clock, in,
-				timeoutMs, this::removeStream);
-		synchronized (lock) {
-			if (streams.isEmpty()) {
-				task = scheduler.scheduleWithFixedDelay(this::checkTimeouts,
-						CHECK_INTERVAL_MS, CHECK_INTERVAL_MS, MILLISECONDS);
-			}
-			streams.add(stream);
-		}
-		return stream;
-	}
-
-	private void removeStream(TimeoutInputStream stream) {
-		Future<?> toCancel = null;
-		synchronized (lock) {
-			if (streams.remove(stream) && streams.isEmpty()) {
-				toCancel = task;
-				task = null;
-			}
-		}
-		if (toCancel != null) toCancel.cancel(false);
-	}
-
-	@Scheduler
-	private void checkTimeouts() {
-		ioExecutor.execute(() -> {
-			List<TimeoutInputStream> snapshot;
-			synchronized (lock) {
-				snapshot = new ArrayList<>(streams);
-			}
-			for (TimeoutInputStream stream : snapshot) {
-				if (stream.hasTimedOut()) {
-					LOG.info("Input stream has timed out");
-					try {
-						stream.close();
-					} catch (IOException e) {
-						logException(LOG, INFO, e);
-					}
-				}
-			}
-		});
-	}
-}

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

@@ -0,0 +1,694 @@
+package org.briarproject.bramble.plugin;
+
+import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.contact.ContactExchangeManager;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.HandshakeManager;
+import org.briarproject.bramble.api.contact.HandshakeManager.HandshakeResult;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
+import org.briarproject.bramble.api.plugin.TransportConnectionReader;
+import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
+import org.briarproject.bramble.api.sync.SyncSession;
+import org.briarproject.bramble.api.sync.SyncSessionFactory;
+import org.briarproject.bramble.api.transport.KeyManager;
+import org.briarproject.bramble.api.transport.StreamContext;
+import org.briarproject.bramble.api.transport.StreamReaderFactory;
+import org.briarproject.bramble.api.transport.StreamWriter;
+import org.briarproject.bramble.api.transport.StreamWriterFactory;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.concurrent.Executor;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
+import static org.briarproject.bramble.util.IoUtils.read;
+import static org.briarproject.bramble.util.LogUtils.logException;
+
+@NotNullByDefault
+class ConnectionManagerImpl implements ConnectionManager {
+
+	private static final Logger LOG =
+			getLogger(ConnectionManagerImpl.class.getName());
+
+	private final Executor ioExecutor;
+	private final KeyManager keyManager;
+	private final StreamReaderFactory streamReaderFactory;
+	private final StreamWriterFactory streamWriterFactory;
+	private final SyncSessionFactory syncSessionFactory;
+	private final HandshakeManager handshakeManager;
+	private final ContactExchangeManager contactExchangeManager;
+	private final ConnectionRegistry connectionRegistry;
+
+	@Inject
+	ConnectionManagerImpl(@IoExecutor Executor ioExecutor,
+			KeyManager keyManager, StreamReaderFactory streamReaderFactory,
+			StreamWriterFactory streamWriterFactory,
+			SyncSessionFactory syncSessionFactory,
+			HandshakeManager handshakeManager,
+			ContactExchangeManager contactExchangeManager,
+			ConnectionRegistry connectionRegistry) {
+		this.ioExecutor = ioExecutor;
+		this.keyManager = keyManager;
+		this.streamReaderFactory = streamReaderFactory;
+		this.streamWriterFactory = streamWriterFactory;
+		this.syncSessionFactory = syncSessionFactory;
+		this.handshakeManager = handshakeManager;
+		this.contactExchangeManager = contactExchangeManager;
+		this.connectionRegistry = connectionRegistry;
+	}
+
+	@Override
+	public void manageIncomingConnection(TransportId t,
+			TransportConnectionReader r) {
+		ioExecutor.execute(new ManageIncomingSimplexConnection(t, r));
+	}
+
+	@Override
+	public void manageIncomingConnection(TransportId t,
+			DuplexTransportConnection d) {
+		ioExecutor.execute(new ManageIncomingDuplexConnection(t, d));
+	}
+
+	@Override
+	public void manageIncomingConnection(PendingContactId p, TransportId t,
+			DuplexTransportConnection d) {
+		ioExecutor.execute(new ManageIncomingHandshakeConnection(p, t, d));
+	}
+
+	@Override
+	public void manageOutgoingConnection(ContactId c, TransportId t,
+			TransportConnectionWriter w) {
+		ioExecutor.execute(new ManageOutgoingSimplexConnection(c, t, w));
+	}
+
+	@Override
+	public void manageOutgoingConnection(ContactId c, TransportId t,
+			DuplexTransportConnection d) {
+		ioExecutor.execute(new ManageOutgoingDuplexConnection(c, t, d));
+	}
+
+	@Override
+	public void manageOutgoingConnection(PendingContactId p, TransportId t,
+			DuplexTransportConnection d) {
+		ioExecutor.execute(new ManageOutgoingHandshakeConnection(p, t, d));
+	}
+
+	private byte[] readTag(InputStream in) throws IOException {
+		byte[] tag = new byte[TAG_LENGTH];
+		read(in, tag);
+		return tag;
+	}
+
+	private SyncSession createIncomingSession(StreamContext ctx,
+			TransportConnectionReader r) throws IOException {
+		InputStream streamReader = streamReaderFactory.createStreamReader(
+				r.getInputStream(), ctx);
+		ContactId c = requireNonNull(ctx.getContactId());
+		return syncSessionFactory.createIncomingSession(c, streamReader);
+	}
+
+	private SyncSession createSimplexOutgoingSession(StreamContext ctx,
+			TransportConnectionWriter w) throws IOException {
+		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
+				w.getOutputStream(), ctx);
+		ContactId c = requireNonNull(ctx.getContactId());
+		return syncSessionFactory.createSimplexOutgoingSession(c,
+				w.getMaxLatency(), streamWriter);
+	}
+
+	private SyncSession createDuplexOutgoingSession(StreamContext ctx,
+			TransportConnectionWriter w) throws IOException {
+		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
+				w.getOutputStream(), ctx);
+		ContactId c = requireNonNull(ctx.getContactId());
+		return syncSessionFactory.createDuplexOutgoingSession(c,
+				w.getMaxLatency(), w.getMaxIdleTime(), streamWriter);
+	}
+
+	private void disposeOnError(TransportConnectionReader reader,
+			boolean recognised) {
+		try {
+			reader.dispose(true, recognised);
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
+	private void disposeOnError(TransportConnectionWriter writer) {
+		try {
+			writer.dispose(true);
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+		}
+	}
+
+	private class ManageIncomingSimplexConnection implements Runnable {
+
+		private final TransportId transportId;
+		private final TransportConnectionReader reader;
+
+		private ManageIncomingSimplexConnection(TransportId transportId,
+				TransportConnectionReader reader) {
+			this.transportId = transportId;
+			this.reader = reader;
+		}
+
+		@Override
+		public void run() {
+			// Read and recognise the tag
+			StreamContext ctx;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctx = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError(false);
+				return;
+			}
+			if (ctx == null) {
+				LOG.info("Unrecognised tag");
+				onError(false);
+				return;
+			}
+			ContactId contactId = ctx.getContactId();
+			if (contactId == null) {
+				LOG.warning("Received rendezvous stream, expected contact");
+				onError(true);
+				return;
+			}
+			if (ctx.isHandshakeMode()) {
+				// TODO: Support handshake mode for contacts
+				LOG.warning("Received handshake tag, expected rotation mode");
+				onError(true);
+				return;
+			}
+			connectionRegistry.registerConnection(contactId, transportId, true);
+			try {
+				// Create and run the incoming session
+				createIncomingSession(ctx, reader).run();
+				reader.dispose(false, true);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onError(true);
+			} finally {
+				connectionRegistry.unregisterConnection(contactId, transportId,
+						true);
+			}
+		}
+
+		private void onError(boolean recognised) {
+			disposeOnError(reader, recognised);
+		}
+	}
+
+	private class ManageOutgoingSimplexConnection implements Runnable {
+
+		private final ContactId contactId;
+		private final TransportId transportId;
+		private final TransportConnectionWriter writer;
+
+		private ManageOutgoingSimplexConnection(ContactId contactId,
+				TransportId transportId, TransportConnectionWriter writer) {
+			this.contactId = contactId;
+			this.transportId = transportId;
+			this.writer = writer;
+		}
+
+		@Override
+		public void run() {
+			// Allocate a stream context
+			StreamContext ctx;
+			try {
+				ctx = keyManager.getStreamContext(contactId, transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				return;
+			}
+			if (ctx == null) {
+				LOG.warning("Could not allocate stream context");
+				onError();
+				return;
+			}
+			connectionRegistry.registerConnection(contactId, transportId,
+					false);
+			try {
+				// Create and run the outgoing session
+				createSimplexOutgoingSession(ctx, writer).run();
+				writer.dispose(false);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onError();
+			} finally {
+				connectionRegistry.unregisterConnection(contactId, transportId,
+						false);
+			}
+		}
+
+		private void onError() {
+			disposeOnError(writer);
+		}
+	}
+
+	private class ManageIncomingDuplexConnection implements Runnable {
+
+		private final TransportId transportId;
+		private final TransportConnectionReader reader;
+		private final TransportConnectionWriter writer;
+
+		@Nullable
+		private volatile SyncSession outgoingSession = null;
+
+		private ManageIncomingDuplexConnection(TransportId transportId,
+				DuplexTransportConnection connection) {
+			this.transportId = transportId;
+			reader = connection.getReader();
+			writer = connection.getWriter();
+		}
+
+		@Override
+		public void run() {
+			// Read and recognise the tag
+			StreamContext ctx;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctx = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onReadError(false);
+				return;
+			}
+			if (ctx == null) {
+				LOG.info("Unrecognised tag");
+				onReadError(false);
+				return;
+			}
+			ContactId contactId = ctx.getContactId();
+			if (contactId == null) {
+				LOG.warning("Expected contact tag, got rendezvous tag");
+				onReadError(true);
+				return;
+			}
+			if (ctx.isHandshakeMode()) {
+				// TODO: Support handshake mode for contacts
+				LOG.warning("Received handshake tag, expected rotation mode");
+				onReadError(true);
+				return;
+			}
+			connectionRegistry.registerConnection(contactId, transportId, true);
+			// Start the outgoing session on another thread
+			ioExecutor.execute(() -> runOutgoingSession(contactId));
+			try {
+				// Create and run the incoming session
+				createIncomingSession(ctx, reader).run();
+				reader.dispose(false, true);
+				// Interrupt the outgoing session so it finishes cleanly
+				SyncSession out = outgoingSession;
+				if (out != null) out.interrupt();
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onReadError(true);
+			} finally {
+				connectionRegistry.unregisterConnection(contactId, transportId,
+						true);
+			}
+		}
+
+		private void runOutgoingSession(ContactId contactId) {
+			// Allocate a stream context
+			StreamContext ctx;
+			try {
+				ctx = keyManager.getStreamContext(contactId, transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onWriteError();
+				return;
+			}
+			if (ctx == null) {
+				LOG.warning("Could not allocate stream context");
+				onWriteError();
+				return;
+			}
+			try {
+				// Create and run the outgoing session
+				SyncSession out = createDuplexOutgoingSession(ctx, writer);
+				outgoingSession = out;
+				out.run();
+				writer.dispose(false);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onWriteError();
+			}
+		}
+
+		private void onReadError(boolean recognised) {
+			disposeOnError(reader, recognised);
+			disposeOnError(writer);
+			// Interrupt the outgoing session so it finishes
+			SyncSession out = outgoingSession;
+			if (out != null) out.interrupt();
+		}
+
+		private void onWriteError() {
+			disposeOnError(reader, true);
+			disposeOnError(writer);
+		}
+	}
+
+	private class ManageOutgoingDuplexConnection implements Runnable {
+
+		private final ContactId contactId;
+		private final TransportId transportId;
+		private final TransportConnectionReader reader;
+		private final TransportConnectionWriter writer;
+
+		@Nullable
+		private volatile SyncSession outgoingSession = null;
+
+		private ManageOutgoingDuplexConnection(ContactId contactId,
+				TransportId transportId, DuplexTransportConnection connection) {
+			this.contactId = contactId;
+			this.transportId = transportId;
+			reader = connection.getReader();
+			writer = connection.getWriter();
+		}
+
+		@Override
+		public void run() {
+			// Allocate a stream context
+			StreamContext ctx;
+			try {
+				ctx = keyManager.getStreamContext(contactId, transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onWriteError();
+				return;
+			}
+			if (ctx == null) {
+				LOG.warning("Could not allocate stream context");
+				onWriteError();
+				return;
+			}
+			if (ctx.isHandshakeMode()) {
+				// TODO: Support handshake mode for contacts
+				LOG.warning("Cannot use handshake mode stream context");
+				onWriteError();
+				return;
+			}
+			// Start the incoming session on another thread
+			ioExecutor.execute(this::runIncomingSession);
+			try {
+				// Create and run the outgoing session
+				SyncSession out = createDuplexOutgoingSession(ctx, writer);
+				outgoingSession = out;
+				out.run();
+				writer.dispose(false);
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onWriteError();
+			}
+		}
+
+		private void runIncomingSession() {
+			// Read and recognise the tag
+			StreamContext ctx;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctx = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onReadError();
+				return;
+			}
+			// Unrecognised tags are suspicious in this case
+			if (ctx == null) {
+				LOG.warning("Unrecognised tag for returning stream");
+				onReadError();
+				return;
+			}
+			// Check that the stream comes from the expected contact
+			ContactId inContactId = ctx.getContactId();
+			if (inContactId == null) {
+				LOG.warning("Expected contact tag, got rendezvous tag");
+				onReadError();
+				return;
+			}
+			if (!contactId.equals(inContactId)) {
+				LOG.warning("Wrong contact ID for returning stream");
+				onReadError();
+				return;
+			}
+			if (ctx.isHandshakeMode()) {
+				// TODO: Support handshake mode for contacts
+				LOG.warning("Received handshake tag, expected rotation mode");
+				onReadError();
+				return;
+			}
+			connectionRegistry.registerConnection(contactId, transportId,
+					false);
+			try {
+				// Create and run the incoming session
+				createIncomingSession(ctx, reader).run();
+				reader.dispose(false, true);
+				// Interrupt the outgoing session so it finishes cleanly
+				SyncSession out = outgoingSession;
+				if (out != null) out.interrupt();
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onReadError();
+			} finally {
+				connectionRegistry.unregisterConnection(contactId, transportId,
+						false);
+			}
+		}
+
+		private void onReadError() {
+			// 'Recognised' is always true for outgoing connections
+			disposeOnError(reader, true);
+			disposeOnError(writer);
+			// Interrupt the outgoing session so it finishes
+			SyncSession out = outgoingSession;
+			if (out != null) out.interrupt();
+		}
+
+		private void onWriteError() {
+			disposeOnError(reader, true);
+			disposeOnError(writer);
+		}
+	}
+
+	private class ManageIncomingHandshakeConnection implements Runnable {
+
+		private final PendingContactId pendingContactId;
+		private final TransportId transportId;
+		private final DuplexTransportConnection connection;
+		private final TransportConnectionReader reader;
+		private final TransportConnectionWriter writer;
+
+		private ManageIncomingHandshakeConnection(
+				PendingContactId pendingContactId, TransportId transportId,
+				DuplexTransportConnection connection) {
+			this.pendingContactId = pendingContactId;
+			this.transportId = transportId;
+			this.connection = connection;
+			reader = connection.getReader();
+			writer = connection.getWriter();
+		}
+
+		@Override
+		public void run() {
+			// Read and recognise the tag
+			StreamContext ctxIn;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctxIn = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError(false);
+				return;
+			}
+			if (ctxIn == null) {
+				LOG.info("Unrecognised tag");
+				onError(false);
+				return;
+			}
+			PendingContactId inPendingContactId = ctxIn.getPendingContactId();
+			if (inPendingContactId == null) {
+				LOG.warning("Expected rendezvous tag, got contact tag");
+				onError(true);
+				return;
+			}
+			// Allocate the outgoing stream context
+			StreamContext ctxOut;
+			try {
+				ctxOut = keyManager.getStreamContext(pendingContactId,
+						transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onError(true);
+				return;
+			}
+			if (ctxOut == null) {
+				LOG.warning("Could not allocate stream context");
+				onError(true);
+				return;
+			}
+			// Close the connection if it's redundant
+			if (!connectionRegistry.registerConnection(pendingContactId)) {
+				LOG.info("Redundant rendezvous connection");
+				onError(true);
+				return;
+			}
+			// Handshake and exchange contacts
+			try {
+				InputStream in = streamReaderFactory.createStreamReader(
+						reader.getInputStream(), ctxIn);
+				// Flush the output stream to send the outgoing stream header
+				StreamWriter out = streamWriterFactory.createStreamWriter(
+						writer.getOutputStream(), ctxOut);
+				out.getOutputStream().flush();
+				HandshakeResult result = handshakeManager.handshake(
+						pendingContactId, in, out);
+				Contact contact = contactExchangeManager.exchangeContacts(
+						pendingContactId, connection, result.getMasterKey(),
+						result.isAlice(), false);
+				connectionRegistry.unregisterConnection(pendingContactId, true);
+				// Reuse the connection as a transport connection
+				manageOutgoingConnection(contact.getId(), transportId,
+						connection);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError(true);
+				connectionRegistry.unregisterConnection(pendingContactId,
+						false);
+			}
+		}
+
+		private void onError(boolean recognised) {
+			disposeOnError(reader, recognised);
+			disposeOnError(writer);
+		}
+	}
+
+	private class ManageOutgoingHandshakeConnection implements Runnable {
+
+		private final PendingContactId pendingContactId;
+		private final TransportId transportId;
+		private final DuplexTransportConnection connection;
+		private final TransportConnectionReader reader;
+		private final TransportConnectionWriter writer;
+
+		private ManageOutgoingHandshakeConnection(
+				PendingContactId pendingContactId, TransportId transportId,
+				DuplexTransportConnection connection) {
+			this.pendingContactId = pendingContactId;
+			this.transportId = transportId;
+			this.connection = connection;
+			reader = connection.getReader();
+			writer = connection.getWriter();
+		}
+
+		@Override
+		public void run() {
+			// Allocate the outgoing stream context
+			StreamContext ctxOut;
+			try {
+				ctxOut = keyManager.getStreamContext(pendingContactId,
+						transportId);
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				return;
+			}
+			if (ctxOut == null) {
+				LOG.warning("Could not allocate stream context");
+				onError();
+				return;
+			}
+			// Flush the output stream to send the outgoing stream header
+			StreamWriter out;
+			try {
+				out = streamWriterFactory.createStreamWriter(
+						writer.getOutputStream(), ctxOut);
+				out.getOutputStream().flush();
+			} catch (IOException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				return;
+			}
+			// Read and recognise the tag
+			StreamContext ctxIn;
+			try {
+				byte[] tag = readTag(reader.getInputStream());
+				ctxIn = keyManager.getStreamContext(transportId, tag);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				return;
+			}
+			// Unrecognised tags are suspicious in this case
+			if (ctxIn == null) {
+				LOG.warning("Unrecognised tag for returning stream");
+				onError();
+				return;
+			}
+			// Check that the stream comes from the expected pending contact
+			PendingContactId inPendingContactId = ctxIn.getPendingContactId();
+			if (inPendingContactId == null) {
+				LOG.warning("Expected rendezvous tag, got contact tag");
+				onError();
+				return;
+			}
+			if (!inPendingContactId.equals(pendingContactId)) {
+				LOG.warning("Wrong pending contact ID for returning stream");
+				onError();
+				return;
+			}
+			// Close the connection if it's redundant
+			if (!connectionRegistry.registerConnection(pendingContactId)) {
+				LOG.info("Redundant rendezvous connection");
+				onError();
+				return;
+			}
+			// Handshake and exchange contacts
+			try {
+				InputStream in = streamReaderFactory.createStreamReader(
+						reader.getInputStream(), ctxIn);
+				HandshakeResult result = handshakeManager.handshake(
+						pendingContactId, in, out);
+				Contact contact = contactExchangeManager.exchangeContacts(
+						pendingContactId, connection, result.getMasterKey(),
+						result.isAlice(), false);
+				connectionRegistry.unregisterConnection(pendingContactId, true);
+				// Reuse the connection as a transport connection
+				manageOutgoingConnection(contact.getId(), transportId,
+						connection);
+			} catch (IOException | DbException e) {
+				logException(LOG, WARNING, e);
+				onError();
+				connectionRegistry.unregisterConnection(pendingContactId,
+						false);
+			}
+		}
+
+		private void onError() {
+			// 'Recognised' is always true for outgoing connections
+			disposeOnError(reader, true);
+			disposeOnError(writer);
+		}
+	}
+}

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

@@ -0,0 +1,150 @@
+package org.briarproject.bramble.plugin;
+
+import org.briarproject.bramble.api.Multiset;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.PendingContactId;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
+import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
+import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionClosedEvent;
+import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionOpenedEvent;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.GuardedBy;
+import javax.annotation.concurrent.ThreadSafe;
+import javax.inject.Inject;
+
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Logger.getLogger;
+
+@ThreadSafe
+@NotNullByDefault
+class ConnectionRegistryImpl implements ConnectionRegistry {
+
+	private static final Logger LOG =
+			getLogger(ConnectionRegistryImpl.class.getName());
+
+	private final EventBus eventBus;
+
+	private final Object lock = new Object();
+	@GuardedBy("lock")
+	private final Map<TransportId, Multiset<ContactId>> contactConnections;
+	@GuardedBy("lock")
+	private final Multiset<ContactId> contactCounts;
+	@GuardedBy("lock")
+	private final Set<PendingContactId> connectedPendingContacts;
+
+	@Inject
+	ConnectionRegistryImpl(EventBus eventBus) {
+		this.eventBus = eventBus;
+		contactConnections = new HashMap<>();
+		contactCounts = new Multiset<>();
+		connectedPendingContacts = new HashSet<>();
+	}
+
+	@Override
+	public void registerConnection(ContactId c, TransportId t,
+			boolean incoming) {
+		if (LOG.isLoggable(INFO)) {
+			if (incoming) LOG.info("Incoming connection registered: " + t);
+			else LOG.info("Outgoing connection registered: " + t);
+		}
+		boolean firstConnection = false;
+		synchronized (lock) {
+			Multiset<ContactId> m = contactConnections.get(t);
+			if (m == null) {
+				m = new Multiset<>();
+				contactConnections.put(t, m);
+			}
+			m.add(c);
+			if (contactCounts.add(c) == 1) firstConnection = true;
+		}
+		eventBus.broadcast(new ConnectionOpenedEvent(c, t, incoming));
+		if (firstConnection) {
+			LOG.info("Contact connected");
+			eventBus.broadcast(new ContactConnectedEvent(c));
+		}
+	}
+
+	@Override
+	public void unregisterConnection(ContactId c, TransportId t,
+			boolean incoming) {
+		if (LOG.isLoggable(INFO)) {
+			if (incoming) LOG.info("Incoming connection unregistered: " + t);
+			else LOG.info("Outgoing connection unregistered: " + t);
+		}
+		boolean lastConnection = false;
+		synchronized (lock) {
+			Multiset<ContactId> m = contactConnections.get(t);
+			if (m == null || !m.contains(c))
+				throw new IllegalArgumentException();
+			m.remove(c);
+			if (contactCounts.remove(c) == 0) lastConnection = true;
+		}
+		eventBus.broadcast(new ConnectionClosedEvent(c, t, incoming));
+		if (lastConnection) {
+			LOG.info("Contact disconnected");
+			eventBus.broadcast(new ContactDisconnectedEvent(c));
+		}
+	}
+
+	@Override
+	public Collection<ContactId> getConnectedContacts(TransportId t) {
+		synchronized (lock) {
+			Multiset<ContactId> m = contactConnections.get(t);
+			if (m == null) return Collections.emptyList();
+			List<ContactId> ids = new ArrayList<>(m.keySet());
+			if (LOG.isLoggable(INFO))
+				LOG.info(ids.size() + " contacts connected: " + t);
+			return ids;
+		}
+	}
+
+	@Override
+	public boolean isConnected(ContactId c, TransportId t) {
+		synchronized (lock) {
+			Multiset<ContactId> m = contactConnections.get(t);
+			return m != null && m.contains(c);
+		}
+	}
+
+	@Override
+	public boolean isConnected(ContactId c) {
+		synchronized (lock) {
+			return contactCounts.contains(c);
+		}
+	}
+
+	@Override
+	public boolean registerConnection(PendingContactId p) {
+		boolean added;
+		synchronized (lock) {
+			added = connectedPendingContacts.add(p);
+		}
+		if (added) eventBus.broadcast(new RendezvousConnectionOpenedEvent(p));
+		return added;
+	}
+
+	@Override
+	public void unregisterConnection(PendingContactId p, boolean success) {
+		synchronized (lock) {
+			if (!connectedPendingContacts.remove(p))
+				throw new IllegalArgumentException();
+		}
+		eventBus.broadcast(new RendezvousConnectionClosedEvent(p, success));
+	}
+}

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

@@ -1,12 +1,12 @@
 package org.briarproject.bramble.plugin;
 
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.lifecycle.ServiceException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.PluginConfig;

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

@@ -3,6 +3,8 @@ package org.briarproject.bramble.plugin;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.plugin.BackoffFactory;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.plugin.PluginConfig;
 import org.briarproject.bramble.api.plugin.PluginManager;
 
@@ -27,6 +29,20 @@ public class PluginModule {
 		return new BackoffFactoryImpl();
 	}
 
+	@Provides
+	@Singleton
+	ConnectionManager provideConnectionManager(
+			ConnectionManagerImpl connectionManager) {
+		return connectionManager;
+	}
+
+	@Provides
+	@Singleton
+	ConnectionRegistry provideConnectionRegistry(
+			ConnectionRegistryImpl connectionRegistry) {
+		return connectionRegistry;
+	}
+
 	@Provides
 	@Singleton
 	PluginManager providePluginManager(LifecycleManager lifecycleManager,

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

@@ -1,8 +1,6 @@
 package org.briarproject.bramble.plugin;
 
 import org.briarproject.bramble.api.Pair;
-import org.briarproject.bramble.api.connection.ConnectionManager;
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
 import org.briarproject.bramble.api.db.DbException;
@@ -11,6 +9,8 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
+import org.briarproject.bramble.api.plugin.ConnectionRegistry;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
@@ -98,8 +98,8 @@ class PollerImpl implements Poller, EventListener {
 			ConnectionClosedEvent c = (ConnectionClosedEvent) e;
 			// Reschedule polling, the polling interval may have decreased
 			reschedule(c.getTransportId());
-			// If an outgoing connection failed, try to reconnect
-			if (!c.isIncoming() && c.isException()) {
+			if (!c.isIncoming()) {
+				// Connect to the disconnected contact
 				connectToContact(c.getContactId(), c.getTransportId());
 			}
 		} else if (e instanceof ConnectionOpenedEvent) {
@@ -215,7 +215,7 @@ class PollerImpl implements Poller, EventListener {
 			Map<ContactId, TransportProperties> remote =
 					transportPropertyManager.getRemoteProperties(t);
 			Collection<ContactId> connected =
-					connectionRegistry.getConnectedOrBetterContacts(t);
+					connectionRegistry.getConnectedContacts(t);
 			Collection<Pair<TransportProperties, ConnectionHandler>>
 					properties = new ArrayList<>();
 			for (Entry<ContactId, TransportProperties> e : remote.entrySet()) {

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

@@ -5,7 +5,6 @@ import org.briarproject.bramble.api.Pair;
 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.io.TimeoutMonitor;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.keyagreement.event.KeyAgreementListeningEvent;
@@ -61,13 +60,12 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 			getLogger(BluetoothPlugin.class.getName());
 
 	final BluetoothConnectionLimiter connectionLimiter;
-	final TimeoutMonitor timeoutMonitor;
 
 	private final Executor ioExecutor;
 	private final SecureRandom secureRandom;
 	private final Backoff backoff;
 	private final PluginCallback callback;
-	private final int maxLatency, maxIdleTime;
+	private final int maxLatency;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	private volatile boolean running = false, contactConnections = false;
@@ -107,17 +105,14 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	abstract DuplexTransportConnection discoverAndConnect(String uuid);
 
 	BluetoothPlugin(BluetoothConnectionLimiter connectionLimiter,
-			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
-			SecureRandom secureRandom, Backoff backoff,
-			PluginCallback callback, int maxLatency, int maxIdleTime) {
+			Executor ioExecutor, SecureRandom secureRandom,
+			Backoff backoff, PluginCallback callback, int maxLatency) {
 		this.connectionLimiter = connectionLimiter;
-		this.timeoutMonitor = timeoutMonitor;
 		this.ioExecutor = ioExecutor;
 		this.secureRandom = secureRandom;
 		this.backoff = backoff;
 		this.callback = callback;
 		this.maxLatency = maxLatency;
-		this.maxIdleTime = maxIdleTime;
 	}
 
 	void onAdapterEnabled() {
@@ -146,7 +141,8 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	@Override
 	public int getMaxIdleTime() {
-		return maxIdleTime;
+		// Bluetooth detects dead connections so we don't need keepalives
+		return Integer.MAX_VALUE;
 	}
 
 	@Override
@@ -231,11 +227,9 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 				if (LOG.isLoggable(INFO)) LOG.info(e.toString());
 				return;
 			}
-			LOG.info("Connection received");
-			if (connectionLimiter.contactConnectionOpened(conn)) {
-				backoff.reset();
+			backoff.reset();
+			if (connectionLimiter.contactConnectionOpened(conn))
 				callback.handleConnection(conn);
-			}
 			if (!running) return;
 		}
 	}
@@ -279,10 +273,13 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		String uuid = p.get(PROP_UUID);
 		if (isNullOrEmpty(uuid)) return;
 		ioExecutor.execute(() -> {
+			if (!isRunning() || !shouldAllowContactConnections()) return;
+			if (!connectionLimiter.canOpenContactConnection()) return;
 			DuplexTransportConnection d = createConnection(p);
 			if (d != null) {
 				backoff.reset();
-				h.handleConnection(d);
+				if (connectionLimiter.contactConnectionOpened(d))
+					h.handleConnection(d);
 			}
 		});
 	}
@@ -328,6 +325,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		if (isNullOrEmpty(uuid)) return null;
 		DuplexTransportConnection conn = connect(address, uuid);
 		if (conn == null) return null;
+		// TODO: Why don't we reset the backoff here?
 		return connectionLimiter.contactConnectionOpened(conn) ? conn : null;
 	}
 

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

@@ -17,20 +17,18 @@ import java.io.IOException;
 import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
-import java.net.InterfaceAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
+import java.net.SocketAddress;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.List;
-import java.util.Random;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
-
-import static java.lang.Integer.parseInt;
 import static java.util.Collections.addAll;
+import static java.util.Collections.emptyList;
 import static java.util.Collections.sort;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
@@ -39,7 +37,6 @@ import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TR
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.PREF_LAN_IP_PORTS;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.PROP_IP_PORTS;
-import static org.briarproject.bramble.api.plugin.LanTcpConstants.PROP_PORT;
 import static org.briarproject.bramble.util.ByteUtils.MAX_16_BIT_UNSIGNED;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubSocketAddress;
 import static org.briarproject.bramble.util.StringUtils.isNullOrEmpty;
@@ -50,36 +47,15 @@ class LanTcpPlugin extends TcpPlugin {
 
 	private static final Logger LOG = getLogger(LanTcpPlugin.class.getName());
 
+	private static final LanAddressComparator ADDRESS_COMPARATOR =
+			new LanAddressComparator();
+
 	private static final int MAX_ADDRESSES = 4;
 	private static final String SEPARATOR = ",";
 
-	/**
-	 * The IP address of an Android device providing a wifi access point.
-	 */
-	protected static final InetAddress WIFI_AP_ADDRESS;
-
-	/**
-	 * The IP address of an Android device providing a wifi direct
-	 * legacy mode access point.
-	 */
-	protected static final InetAddress WIFI_DIRECT_AP_ADDRESS;
-
-	static {
-		try {
-			WIFI_AP_ADDRESS = InetAddress.getByAddress(
-					new byte[] {(byte) 192, (byte) 168, 43, 1});
-			WIFI_DIRECT_AP_ADDRESS = InetAddress.getByAddress(
-					new byte[] {(byte) 192, (byte) 168, 49, 1});
-		} catch (UnknownHostException e) {
-			// Should only be thrown if the address has an illegal length
-			throw new AssertionError(e);
-		}
-	}
-
 	LanTcpPlugin(Executor ioExecutor, Backoff backoff, PluginCallback callback,
-			int maxLatency, int maxIdleTime, int connectionTimeout) {
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
-				connectionTimeout);
+			int maxLatency, int maxIdleTime) {
+		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
 	}
 
 	@Override
@@ -87,82 +63,38 @@ class LanTcpPlugin extends TcpPlugin {
 		return ID;
 	}
 
-	@Override
-	public void start() {
-		if (used.getAndSet(true)) throw new IllegalStateException();
-		initialisePortProperty();
-		running = true;
-		bind();
-	}
-
-	protected void initialisePortProperty() {
-		TransportProperties p = callback.getLocalProperties();
-		if (isNullOrEmpty(p.get(PROP_PORT))) {
-			int port = new Random().nextInt(32768) + 32768;
-			p.put(PROP_PORT, String.valueOf(port));
-			callback.mergeLocalProperties(p);
-		}
-	}
-
 	@Override
 	protected List<InetSocketAddress> getLocalSocketAddresses() {
+		// Use the same address and port as last time if available
 		TransportProperties p = callback.getLocalProperties();
-		int preferredPort = parsePortProperty(p.get(PROP_PORT));
 		String oldIpPorts = p.get(PROP_IP_PORTS);
 		List<InetSocketAddress> olds = parseSocketAddresses(oldIpPorts);
-
 		List<InetSocketAddress> locals = new ArrayList<>();
-		List<InetSocketAddress> fallbacks = new ArrayList<>();
-		for (InetAddress local : getUsableLocalInetAddresses()) {
-			// If we've used this address before, try to use the same port
-			int port = preferredPort;
-			for (InetSocketAddress old : olds) {
-				if (old.getAddress().equals(local)) {
-					port = old.getPort();
-					break;
+		for (InetAddress local : getLocalIpAddresses()) {
+			if (isAcceptableAddress(local)) {
+				// If this is the old address, try to use the same port
+				for (InetSocketAddress old : olds) {
+					if (old.getAddress().equals(local))
+						locals.add(new InetSocketAddress(local, old.getPort()));
 				}
+				locals.add(new InetSocketAddress(local, 0));
 			}
-			locals.add(new InetSocketAddress(local, port));
-			// Fall back to any available port
-			fallbacks.add(new InetSocketAddress(local, 0));
 		}
-		locals.addAll(fallbacks);
+		sort(locals, ADDRESS_COMPARATOR);
 		return locals;
 	}
 
-	private int parsePortProperty(@Nullable String portProperty) {
-		if (isNullOrEmpty(portProperty)) return 0;
-		try {
-			return parseInt(portProperty);
-		} catch (NumberFormatException e) {
-			return 0;
-		}
-	}
-
 	private List<InetSocketAddress> parseSocketAddresses(String ipPorts) {
+		if (isNullOrEmpty(ipPorts)) return emptyList();
+		String[] split = ipPorts.split(SEPARATOR);
 		List<InetSocketAddress> addresses = new ArrayList<>();
-		if (isNullOrEmpty(ipPorts)) return addresses;
-		for (String ipPort : ipPorts.split(SEPARATOR)) {
+		for (String ipPort : split) {
 			InetSocketAddress a = parseSocketAddress(ipPort);
 			if (a != null) addresses.add(a);
 		}
 		return addresses;
 	}
 
-	protected List<InetAddress> getUsableLocalInetAddresses() {
-		List<InterfaceAddress> ifAddrs =
-				new ArrayList<>(getLocalInterfaceAddresses());
-		// Prefer longer network prefixes
-		sort(ifAddrs, (a, b) ->
-				b.getNetworkPrefixLength() - a.getNetworkPrefixLength());
-		List<InetAddress> addrs = new ArrayList<>();
-		for (InterfaceAddress ifAddr : ifAddrs) {
-			InetAddress addr = ifAddr.getAddress();
-			if (isAcceptableAddress(addr)) addrs.add(addr);
-		}
-		return addrs;
-	}
-
 	@Override
 	protected void setLocalSocketAddress(InetSocketAddress a) {
 		String ipPort = getIpPortString(a);
@@ -200,20 +132,7 @@ class LanTcpPlugin extends TcpPlugin {
 	@Override
 	protected List<InetSocketAddress> getRemoteSocketAddresses(
 			TransportProperties p) {
-		String ipPorts = p.get(PROP_IP_PORTS);
-		List<InetSocketAddress> remotes = parseSocketAddresses(ipPorts);
-		int port = parsePortProperty(p.get(PROP_PORT));
-		// If the contact has a preferred port, we can guess their IP:port when
-		// they're providing a wifi access point
-		if (port != 0) {
-			InetSocketAddress wifiAp =
-					new InetSocketAddress(WIFI_AP_ADDRESS, port);
-			if (!remotes.contains(wifiAp)) remotes.add(wifiAp);
-			InetSocketAddress wifiDirectAp =
-					new InetSocketAddress(WIFI_DIRECT_AP_ADDRESS, port);
-			if (!remotes.contains(wifiDirectAp)) remotes.add(wifiDirectAp);
-		}
-		return remotes;
+		return parseSocketAddresses(p.get(PROP_IP_PORTS));
 	}
 
 	private boolean isAcceptableAddress(InetAddress a) {
@@ -226,33 +145,52 @@ class LanTcpPlugin extends TcpPlugin {
 	}
 
 	@Override
-	protected boolean isConnectable(InterfaceAddress local,
-			InetSocketAddress remote) {
+	protected boolean isConnectable(InetSocketAddress remote) {
 		if (remote.getPort() == 0) return false;
 		if (!isAcceptableAddress(remote.getAddress())) return false;
 		// Try to determine whether the address is on the same LAN as us
-		byte[] localIp = local.getAddress().getAddress();
+		if (socket == null) return false;
+		byte[] localIp = socket.getInetAddress().getAddress();
 		byte[] remoteIp = remote.getAddress().getAddress();
-		int prefixLength = local.getNetworkPrefixLength();
-		return areAddressesInSameNetwork(localIp, remoteIp, prefixLength);
+		return addressesAreOnSameLan(localIp, remoteIp);
 	}
 
 	// Package access for testing
-	static boolean areAddressesInSameNetwork(byte[] localIp, byte[] remoteIp,
-			int prefixLength) {
-		if (localIp.length != remoteIp.length) return false;
-		// Compare the first prefixLength bits of the addresses
-		for (int i = 0; i < prefixLength; i++) {
-			int byteIndex = i >> 3;
-			int bitIndex = i & 7; // 0 to 7
-			int mask = 128 >> bitIndex; // Select the bit at bitIndex
-			if ((localIp[byteIndex] & mask) != (remoteIp[byteIndex] & mask)) {
-				return false; // Addresses differ at bit i
-			}
-		}
+	boolean addressesAreOnSameLan(byte[] localIp, byte[] remoteIp) {
+		// 10.0.0.0/8
+		if (isPrefix10(localIp)) return isPrefix10(remoteIp);
+		// 172.16.0.0/12
+		if (isPrefix172(localIp)) return isPrefix172(remoteIp);
+		// 192.168.0.0/16
+		if (isPrefix192(localIp)) return isPrefix192(remoteIp);
+		// Unrecognised prefix - may be compatible
 		return true;
 	}
 
+	private static boolean isPrefix10(byte[] ipv4) {
+		return ipv4[0] == 10;
+	}
+
+	private static boolean isPrefix172(byte[] ipv4) {
+		return ipv4[0] == (byte) 172 && (ipv4[1] & 0xF0) == 16;
+	}
+
+	private static boolean isPrefix192(byte[] ipv4) {
+		return ipv4[0] == (byte) 192 && ipv4[1] == (byte) 168;
+	}
+
+	// Returns the prefix length for an RFC 1918 address, or 0 for any other
+	// address
+	private static int getRfc1918PrefixLength(InetAddress addr) {
+		if (!(addr instanceof Inet4Address)) return 0;
+		if (!addr.isSiteLocalAddress()) return 0;
+		byte[] ipv4 = addr.getAddress();
+		if (isPrefix10(ipv4)) return 8;
+		if (isPrefix172(ipv4)) return 12;
+		if (isPrefix192(ipv4)) return 16;
+		return 0;
+	}
+
 	@Override
 	public boolean supportsKeyAgreement() {
 		return true;
@@ -291,12 +229,6 @@ class LanTcpPlugin extends TcpPlugin {
 	public DuplexTransportConnection createKeyAgreementConnection(
 			byte[] commitment, BdfList descriptor) {
 		if (!isRunning()) return null;
-		ServerSocket ss = socket;
-		InterfaceAddress local = getLocalInterfaceAddress(ss.getInetAddress());
-		if (local == null) {
-			LOG.warning("No interface for key agreement server socket");
-			return null;
-		}
 		InetSocketAddress remote;
 		try {
 			remote = parseSocketAddress(descriptor);
@@ -304,11 +236,12 @@ class LanTcpPlugin extends TcpPlugin {
 			LOG.info("Invalid IP/port in key agreement descriptor");
 			return null;
 		}
-		if (!isConnectable(local, remote)) {
+		if (!isConnectable(remote)) {
 			if (LOG.isLoggable(INFO)) {
+				SocketAddress local = socket.getLocalSocketAddress();
 				LOG.info(scrubSocketAddress(remote) +
 						" is not connectable from " +
-						scrubSocketAddress(ss.getLocalSocketAddress()));
+						scrubSocketAddress(local));
 			}
 			return null;
 		}
@@ -316,8 +249,8 @@ class LanTcpPlugin extends TcpPlugin {
 			if (LOG.isLoggable(INFO))
 				LOG.info("Connecting to " + scrubSocketAddress(remote));
 			Socket s = createSocket();
-			s.bind(new InetSocketAddress(ss.getInetAddress(), 0));
-			s.connect(remote, connectionTimeout);
+			s.bind(new InetSocketAddress(socket.getInetAddress(), 0));
+			s.connect(remote);
 			s.setSoTimeout(socketTimeout);
 			if (LOG.isLoggable(INFO))
 				LOG.info("Connected to " + scrubSocketAddress(remote));
@@ -366,4 +299,19 @@ class LanTcpPlugin extends TcpPlugin {
 			IoUtils.tryToClose(ss, LOG, WARNING);
 		}
 	}
+
+	static class LanAddressComparator implements Comparator<InetSocketAddress> {
+
+		@Override
+		public int compare(InetSocketAddress a, InetSocketAddress b) {
+			// Prefer addresses with non-zero ports
+			int aPort = a.getPort(), bPort = b.getPort();
+			if (aPort > 0 && bPort == 0) return -1;
+			if (aPort == 0 && bPort > 0) return 1;
+			// Prefer addresses with longer RFC 1918 prefixes
+			int aPrefix = getRfc1918PrefixLength(a.getAddress());
+			int bPrefix = getRfc1918PrefixLength(b.getAddress());
+			return bPrefix - aPrefix;
+		}
+	}
 }

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

@@ -18,11 +18,10 @@ import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 @NotNullByDefault
 public class LanTcpPluginFactory implements DuplexPluginFactory {
 
-	private static final int MAX_LATENCY = 30_000; // 30 seconds
-	private static final int MAX_IDLE_TIME = 30_000; // 30 seconds
-	private static final int CONNECTION_TIMEOUT = 3_000; // 3 seconds
-	private static final int MIN_POLLING_INTERVAL = 60_000; // 1 minute
-	private static final int MAX_POLLING_INTERVAL = 600_000; // 10 mins
+	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
@@ -49,6 +48,6 @@ public class LanTcpPluginFactory implements DuplexPluginFactory {
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		return new LanTcpPlugin(ioExecutor, backoff, callback, MAX_LATENCY,
-				MAX_IDLE_TIME, CONNECTION_TIMEOUT);
+				MAX_IDLE_TIME);
 	}
 }

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

@@ -19,10 +19,10 @@ import org.briarproject.bramble.util.IoUtils;
 import java.io.IOException;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
-import java.net.InterfaceAddress;
 import java.net.NetworkInterface;
 import java.net.ServerSocket;
 import java.net.Socket;
+import java.net.SocketAddress;
 import java.net.SocketException;
 import java.net.UnknownHostException;
 import java.util.ArrayList;
@@ -36,6 +36,7 @@ import java.util.regex.Pattern;
 
 import javax.annotation.Nullable;
 
+import static java.net.NetworkInterface.getNetworkInterfaces;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.list;
 import static java.util.logging.Level.INFO;
@@ -57,8 +58,7 @@ abstract class TcpPlugin implements DuplexPlugin {
 	protected final Executor ioExecutor, bindExecutor;
 	protected final Backoff backoff;
 	protected final PluginCallback callback;
-	protected final int maxLatency, maxIdleTime;
-	protected final int connectionTimeout, socketTimeout;
+	protected final int maxLatency, maxIdleTime, socketTimeout;
 	protected final AtomicBoolean used = new AtomicBoolean(false);
 
 	protected volatile boolean running = false;
@@ -86,18 +86,15 @@ abstract class TcpPlugin implements DuplexPlugin {
 	/**
 	 * Returns true if connections to the given address can be attempted.
 	 */
-	@SuppressWarnings("BooleanMethodIsAlwaysInverted")
-	protected abstract boolean isConnectable(InterfaceAddress local,
-			InetSocketAddress remote);
+	protected abstract boolean isConnectable(InetSocketAddress remote);
 
 	TcpPlugin(Executor ioExecutor, Backoff backoff, PluginCallback callback,
-			int maxLatency, int maxIdleTime, int connectionTimeout) {
+			int maxLatency, int maxIdleTime) {
 		this.ioExecutor = ioExecutor;
 		this.backoff = backoff;
 		this.callback = callback;
 		this.maxLatency = maxLatency;
 		this.maxIdleTime = maxIdleTime;
-		this.connectionTimeout = connectionTimeout;
 		if (maxIdleTime > Integer.MAX_VALUE / 2)
 			socketTimeout = Integer.MAX_VALUE;
 		else socketTimeout = maxIdleTime * 2;
@@ -233,23 +230,13 @@ abstract class TcpPlugin implements DuplexPlugin {
 	@Override
 	public DuplexTransportConnection createConnection(TransportProperties p) {
 		if (!isRunning()) return null;
-		ServerSocket ss = socket;
-		InterfaceAddress local = getLocalInterfaceAddress(ss.getInetAddress());
-		if (local == null) {
-			LOG.warning("No interface for server socket");
-			return null;
-		}
 		for (InetSocketAddress remote : getRemoteSocketAddresses(p)) {
-			// Don't try to connect to our own address
-			if (!canConnectToOwnAddress() &&
-					remote.getAddress().equals(ss.getInetAddress())) {
-				continue;
-			}
-			if (!isConnectable(local, remote)) {
+			if (!isConnectable(remote)) {
 				if (LOG.isLoggable(INFO)) {
+					SocketAddress local = socket.getLocalSocketAddress();
 					LOG.info(scrubSocketAddress(remote) +
 							" is not connectable from " +
-							scrubSocketAddress(ss.getLocalSocketAddress()));
+							scrubSocketAddress(local));
 				}
 				continue;
 			}
@@ -257,8 +244,8 @@ abstract class TcpPlugin implements DuplexPlugin {
 				if (LOG.isLoggable(INFO))
 					LOG.info("Connecting to " + scrubSocketAddress(remote));
 				Socket s = createSocket();
-				s.bind(new InetSocketAddress(ss.getInetAddress(), 0));
-				s.connect(remote, connectionTimeout);
+				s.bind(new InetSocketAddress(socket.getInetAddress(), 0));
+				s.connect(remote);
 				s.setSoTimeout(socketTimeout);
 				if (LOG.isLoggable(INFO))
 					LOG.info("Connected to " + scrubSocketAddress(remote));
@@ -272,19 +259,6 @@ abstract class TcpPlugin implements DuplexPlugin {
 		return null;
 	}
 
-	@Nullable
-	InterfaceAddress getLocalInterfaceAddress(InetAddress a) {
-		for (InterfaceAddress ifAddr : getLocalInterfaceAddresses()) {
-			if (ifAddr.getAddress().equals(a)) return ifAddr;
-		}
-		return null;
-	}
-
-	// Override for testing
-	protected boolean canConnectToOwnAddress() {
-		return false;
-	}
-
 	protected Socket createSocket() throws IOException {
 		return new Socket();
 	}
@@ -340,27 +314,14 @@ abstract class TcpPlugin implements DuplexPlugin {
 		throw new UnsupportedOperationException();
 	}
 
-	List<InterfaceAddress> getLocalInterfaceAddresses() {
-		List<InterfaceAddress> addrs = new ArrayList<>();
-		for (NetworkInterface iface : getNetworkInterfaces()) {
-			addrs.addAll(iface.getInterfaceAddresses());
-		}
-		return addrs;
-	}
-
-	List<InetAddress> getLocalInetAddresses() {
-		List<InetAddress> addrs = new ArrayList<>();
-		for (NetworkInterface iface : getNetworkInterfaces()) {
-			addrs.addAll(list(iface.getInetAddresses()));
-		}
-		return addrs;
-	}
-
-	private List<NetworkInterface> getNetworkInterfaces() {
+	Collection<InetAddress> getLocalIpAddresses() {
 		try {
-			Enumeration<NetworkInterface> ifaces =
-					NetworkInterface.getNetworkInterfaces();
-			return ifaces == null ? emptyList() : list(ifaces);
+			Enumeration<NetworkInterface> ifaces = getNetworkInterfaces();
+			if (ifaces == null) return emptyList();
+			List<InetAddress> addrs = new ArrayList<>();
+			for (NetworkInterface iface : list(ifaces))
+				addrs.addAll(list(iface.getInetAddresses()));
+			return addrs;
 		} catch (SocketException e) {
 			logException(LOG, WARNING, e);
 			return emptyList();

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

@@ -10,7 +10,6 @@ import org.briarproject.bramble.api.properties.TransportProperties;
 import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
-import java.net.InterfaceAddress;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.concurrent.Executor;
@@ -30,10 +29,8 @@ class WanTcpPlugin extends TcpPlugin {
 	private volatile MappingResult mappingResult;
 
 	WanTcpPlugin(Executor ioExecutor, Backoff backoff, PortMapper portMapper,
-			PluginCallback callback, int maxLatency, int maxIdleTime,
-			int connectionTimeout) {
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
-				connectionTimeout);
+			PluginCallback callback, int maxLatency, int maxIdleTime) {
+		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
 		this.portMapper = portMapper;
 	}
 
@@ -48,7 +45,7 @@ class WanTcpPlugin extends TcpPlugin {
 		TransportProperties p = callback.getLocalProperties();
 		InetSocketAddress old = parseSocketAddress(p.get(PROP_IP_PORT));
 		List<InetSocketAddress> addrs = new LinkedList<>();
-		for (InetAddress a : getLocalInetAddresses()) {
+		for (InetAddress a : getLocalIpAddresses()) {
 			if (isAcceptableAddress(a)) {
 				// If this is the old address, try to use the same port
 				if (old != null && old.getAddress().equals(a))
@@ -89,8 +86,7 @@ class WanTcpPlugin extends TcpPlugin {
 	}
 
 	@Override
-	protected boolean isConnectable(InterfaceAddress local,
-			InetSocketAddress remote) {
+	protected boolean isConnectable(InetSocketAddress remote) {
 		if (remote.getPort() == 0) return false;
 		return isAcceptableAddress(remote.getAddress());
 	}

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

@@ -19,11 +19,10 @@ import static org.briarproject.bramble.api.plugin.WanTcpConstants.ID;
 @NotNullByDefault
 public class WanTcpPluginFactory implements DuplexPluginFactory {
 
-	private static final int MAX_LATENCY = 30_000; // 30 seconds
-	private static final int MAX_IDLE_TIME = 30_000; // 30 seconds
-	private static final int CONNECTION_TIMEOUT = 30_000; // 30 seconds
-	private static final int MIN_POLLING_INTERVAL = 60_000; // 1 minute
-	private static final int MAX_POLLING_INTERVAL = 600_000; // 10 mins
+	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
 	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
@@ -53,6 +52,6 @@ public class WanTcpPluginFactory implements DuplexPluginFactory {
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		return new WanTcpPlugin(ioExecutor, backoff,
 				new PortMapperImpl(shutdownManager), callback, MAX_LATENCY,
-				MAX_IDLE_TIME, CONNECTION_TIMEOUT);
+				MAX_IDLE_TIME);
 	}
 }

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

@@ -195,6 +195,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (!assetsAreUpToDate()) installAssets();
 		if (cookieFile.exists() && !cookieFile.delete())
 			LOG.warning("Old auth cookie not deleted");
+		// Migrate old settings before having a chance to stop
+		migrateSettings();
 		// Start a new Tor process
 		LOG.info("Starting Tor");
 		String torPath = torFile.getAbsolutePath();
@@ -814,6 +816,21 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		controlConnection.setConf("ConnectionPadding", enable ? "1" : "0");
 	}
 
+	// TODO remove when sufficient time has passed. Added 2018-08-15
+	private void migrateSettings() {
+		Settings sOld = callback.getSettings();
+		int oldNetwork = sOld.getInt("network", -1);
+		if (oldNetwork == -1) return;
+		Settings s = new Settings();
+		if (oldNetwork == 0) {
+			s.putInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_NEVER);
+		} else if (oldNetwork == 1) {
+			s.putBoolean(PREF_TOR_MOBILE, false);
+		}
+		s.putInt("network", -1);
+		callback.mergeSettings(s);
+	}
+
 	private static class ConnectionStatus {
 
 		// All of the following are locking: this

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

@@ -37,11 +37,6 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
-import static org.briarproject.bramble.api.properties.TransportPropertyConstants.GROUP_KEY_DISCOVERED;
-import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_LOCAL;
-import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_TRANSPORT_ID;
-import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MSG_KEY_VERSION;
-
 @Immutable
 @NotNullByDefault
 class TransportPropertyManagerImpl implements TransportPropertyManager,
@@ -116,10 +111,10 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		try {
 			// Find the latest update for this transport, if any
 			BdfDictionary d = metadataParser.parse(meta);
-			TransportId t = new TransportId(d.getString(MSG_KEY_TRANSPORT_ID));
+			TransportId t = new TransportId(d.getString("transportId"));
 			LatestUpdate latest = findLatest(txn, m.getGroupId(), t, false);
 			if (latest != null) {
-				if (d.getLong(MSG_KEY_VERSION) > latest.version) {
+				if (d.getLong("version") > latest.version) {
 					// This update is newer - delete the previous update
 					db.deleteMessage(txn, latest.messageId);
 					db.deleteMessageMetadata(txn, latest.messageId);
@@ -145,27 +140,6 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		}
 	}
 
-	@Override
-	public void addRemotePropertiesFromConnection(ContactId c, TransportId t,
-			TransportProperties props) throws DbException {
-		if (props.isEmpty()) return;
-		try {
-			db.transaction(false, txn -> {
-				Group g = getContactGroup(db.getContact(txn, c));
-				BdfDictionary meta = clientHelper.getGroupMetadataAsDictionary(
-						txn, g.getId());
-				BdfDictionary discovered =
-						meta.getOptionalDictionary(GROUP_KEY_DISCOVERED);
-				if (discovered == null) discovered = new BdfDictionary();
-				discovered.putAll(props);
-				meta.put(GROUP_KEY_DISCOVERED, discovered);
-				clientHelper.mergeGroupMetadata(txn, g.getId(), meta);
-			});
-		} catch (FormatException e) {
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public Map<TransportId, TransportProperties> getLocalProperties()
 			throws DbException {
@@ -229,26 +203,12 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 		Group g = getContactGroup(c);
 		try {
 			// Find the latest remote update
-			TransportProperties remote;
 			LatestUpdate latest = findLatest(txn, g.getId(), t, false);
-			if (latest == null) {
-				remote = new TransportProperties();
-			} else {
-				// Retrieve and parse the latest remote properties
-				BdfList message =
-						clientHelper.getMessageAsList(txn, latest.messageId);
-				remote = parseProperties(message);
-			}
-			// Merge in any discovered properties
-			BdfDictionary meta =
-					clientHelper.getGroupMetadataAsDictionary(txn, g.getId());
-			BdfDictionary d = meta.getOptionalDictionary(GROUP_KEY_DISCOVERED);
-			if (d == null) return remote;
-			TransportProperties merged =
-					clientHelper.parseAndValidateTransportProperties(d);
-			// Received properties override discovered properties
-			merged.putAll(remote);
-			return merged;
+			if (latest == null) return new TransportProperties();
+			// Retrieve and parse the latest remote properties
+			BdfList message =
+					clientHelper.getMessageAsList(txn, latest.messageId);
+			return parseProperties(message);
 		} catch (FormatException e) {
 			throw new DbException(e);
 		}
@@ -321,9 +281,9 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 			long now = clock.currentTimeMillis();
 			Message m = clientHelper.createMessage(g, now, body);
 			BdfDictionary meta = new BdfDictionary();
-			meta.put(MSG_KEY_TRANSPORT_ID, t.getString());
-			meta.put(MSG_KEY_VERSION, version);
-			meta.put(MSG_KEY_LOCAL, local);
+			meta.put("transportId", t.getString());
+			meta.put("version", version);
+			meta.put("local", local);
 			clientHelper.addLocalMessage(txn, m, meta, shared, false);
 		} catch (FormatException e) {
 			throw new RuntimeException(e);
@@ -342,9 +302,8 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 				.getMessageMetadataAsDictionary(txn, localGroup.getId());
 		for (Entry<MessageId, BdfDictionary> e : metadata.entrySet()) {
 			BdfDictionary meta = e.getValue();
-			TransportId t =
-					new TransportId(meta.getString(MSG_KEY_TRANSPORT_ID));
-			long version = meta.getLong(MSG_KEY_VERSION);
+			TransportId t = new TransportId(meta.getString("transportId"));
+			long version = meta.getLong("version");
 			latestUpdates.put(t, new LatestUpdate(e.getKey(), version));
 		}
 		return latestUpdates;
@@ -357,10 +316,9 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 				clientHelper.getMessageMetadataAsDictionary(txn, g);
 		for (Entry<MessageId, BdfDictionary> e : metadata.entrySet()) {
 			BdfDictionary meta = e.getValue();
-			if (meta.getString(MSG_KEY_TRANSPORT_ID).equals(t.getString())
-					&& meta.getBoolean(MSG_KEY_LOCAL) == local) {
-				return new LatestUpdate(e.getKey(),
-						meta.getLong(MSG_KEY_VERSION));
+			if (meta.getString("transportId").equals(t.getString())
+					&& meta.getBoolean("local") == local) {
+				return new LatestUpdate(e.getKey(), meta.getLong("version"));
 			}
 		}
 		return null;

bramble-core/src/main/java/org/briarproject/bramble/rendezvous/RendezvousPollerImpl.java

@@ -2,7 +2,6 @@ package org.briarproject.bramble.rendezvous;
 
 import org.briarproject.bramble.PoliteExecutor;
 import org.briarproject.bramble.api.Pair;
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.contact.PendingContactState;
@@ -24,6 +23,7 @@ import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.lifecycle.ServiceException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
+import org.briarproject.bramble.api.plugin.ConnectionManager;
 import org.briarproject.bramble.api.plugin.Plugin;
 import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;

bramble-core/src/main/java/org/briarproject/bramble/sync/DuplexOutgoingSession.java

@@ -14,7 +14,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.Priority;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
 import org.briarproject.bramble.api.sync.SyncSession;
@@ -36,7 +35,6 @@ import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
 import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
@@ -76,8 +74,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	private final int maxLatency, maxIdleTime;
 	private final StreamWriter streamWriter;
 	private final SyncRecordWriter recordWriter;
-	@Nullable
-	private final Priority priority;
 	private final BlockingQueue<ThrowingRunnable<IOException>> writerTasks;
 
 	private final AtomicBoolean generateAckQueued = new AtomicBoolean(false);
@@ -92,7 +88,7 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	DuplexOutgoingSession(DatabaseComponent db, Executor dbExecutor,
 			EventBus eventBus, Clock clock, ContactId contactId, int maxLatency,
 			int maxIdleTime, StreamWriter streamWriter,
-			SyncRecordWriter recordWriter, @Nullable Priority priority) {
+			SyncRecordWriter recordWriter) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
@@ -102,7 +98,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		this.maxIdleTime = maxIdleTime;
 		this.streamWriter = streamWriter;
 		this.recordWriter = recordWriter;
-		this.priority = priority;
 		writerTasks = new LinkedBlockingQueue<>();
 	}
 
@@ -113,8 +108,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 		try {
 			// Send our supported protocol versions
 			recordWriter.writeVersions(new Versions(SUPPORTED_VERSIONS));
-			// Send our connection priority, if this is an outgoing connection
-			if (priority != null) recordWriter.writePriority(priority);
 			// Start a query for each type of record
 			generateAck();
 			generateBatch();
@@ -166,9 +159,6 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 						dataToFlush = true;
 					}
 				}
-				// Write any records that were already in the queue
-				ThrowingRunnable<IOException> task;
-				while ((task = writerTasks.poll()) != null) task.run();
 				streamWriter.sendEndOfStream();
 			} catch (InterruptedException e) {
 				LOG.info("Interrupted while waiting for a record to write");

bramble-core/src/main/java/org/briarproject/bramble/sync/IncomingSession.java

@@ -15,8 +15,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.Priority;
-import org.briarproject.bramble.api.sync.PriorityHandler;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
 import org.briarproject.bramble.api.sync.SyncSession;
@@ -49,19 +47,17 @@ class IncomingSession implements SyncSession, EventListener {
 	private final EventBus eventBus;
 	private final ContactId contactId;
 	private final SyncRecordReader recordReader;
-	private final PriorityHandler priorityHandler;
 
 	private volatile boolean interrupted = false;
 
 	IncomingSession(DatabaseComponent db, Executor dbExecutor,
 			EventBus eventBus, ContactId contactId,
-			SyncRecordReader recordReader, PriorityHandler priorityHandler) {
+			SyncRecordReader recordReader) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
 		this.eventBus = eventBus;
 		this.contactId = contactId;
 		this.recordReader = recordReader;
-		this.priorityHandler = priorityHandler;
 	}
 
 	@IoExecutor
@@ -90,9 +86,6 @@ class IncomingSession implements SyncSession, EventListener {
 				} else if (recordReader.hasVersions()) {
 					Versions v = recordReader.readVersions();
 					dbExecutor.execute(new ReceiveVersions(v));
-				} else if (recordReader.hasPriority()) {
-					Priority p = recordReader.readPriority();
-					priorityHandler.handle(p);
 				} else {
 					// unknown records are ignored in RecordReader#eof()
 					throw new FormatException();

bramble-core/src/main/java/org/briarproject/bramble/sync/SimplexOutgoingSession.java

@@ -95,9 +95,6 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 					if (task == CLOSE) break;
 					task.run();
 				}
-				// Write any records that were already in the queue
-				ThrowingRunnable<IOException> task;
-				while ((task = writerTasks.poll()) != null) task.run();
 				streamWriter.sendEndOfStream();
 			} catch (InterruptedException e) {
 				LOG.info("Interrupted while waiting for a record to write");

bramble-core/src/main/java/org/briarproject/bramble/sync/SyncRecordReaderImpl.java

@@ -11,7 +11,6 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.Priority;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
 import org.briarproject.bramble.api.sync.Versions;
@@ -27,12 +26,10 @@ import javax.annotation.concurrent.NotThreadSafe;
 import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
 import static org.briarproject.bramble.api.sync.RecordTypes.MESSAGE;
 import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
-import static org.briarproject.bramble.api.sync.RecordTypes.PRIORITY;
 import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
 import static org.briarproject.bramble.api.sync.RecordTypes.VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_SUPPORTED_VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
-import static org.briarproject.bramble.api.sync.SyncConstants.PRIORITY_NONCE_BYTES;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
 
 @NotThreadSafe
@@ -51,7 +48,7 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 
 	private static boolean isKnownRecordType(byte type) {
 		return type == ACK || type == MESSAGE || type == OFFER ||
-				type == REQUEST || type == VERSIONS || type == PRIORITY;
+				type == REQUEST || type == VERSIONS;
 	}
 
 	private final MessageFactory messageFactory;
@@ -177,23 +174,4 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 		nextRecord = null;
 		return supported;
 	}
-
-	@Override
-	public boolean hasPriority() throws IOException {
-		return !eof() && getNextRecordType() == PRIORITY;
-	}
-
-	@Override
-	public Priority readPriority() throws IOException {
-		if (!hasPriority()) throw new FormatException();
-		return new Priority(readNonce());
-	}
-
-	private byte[] readNonce() throws IOException {
-		if (nextRecord == null) throw new AssertionError();
-		byte[] payload = nextRecord.getPayload();
-		if (payload.length != PRIORITY_NONCE_BYTES) throw new FormatException();
-		nextRecord = null;
-		return payload;
-	}
 }

bramble-core/src/main/java/org/briarproject/bramble/sync/SyncRecordWriterImpl.java

@@ -8,7 +8,6 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.Offer;
-import org.briarproject.bramble.api.sync.Priority;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
 import org.briarproject.bramble.api.sync.Versions;
@@ -21,7 +20,6 @@ import javax.annotation.concurrent.NotThreadSafe;
 import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
 import static org.briarproject.bramble.api.sync.RecordTypes.MESSAGE;
 import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
-import static org.briarproject.bramble.api.sync.RecordTypes.PRIORITY;
 import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
 import static org.briarproject.bramble.api.sync.RecordTypes.VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
@@ -75,12 +73,6 @@ class SyncRecordWriterImpl implements SyncRecordWriter {
 		writeRecord(VERSIONS);
 	}
 
-	@Override
-	public void writePriority(Priority p) throws IOException {
-		writer.writeRecord(
-				new Record(PROTOCOL_VERSION, PRIORITY, p.getNonce()));
-	}
-
 	@Override
 	public void flush() throws IOException {
 		writer.flush();

bramble-core/src/main/java/org/briarproject/bramble/sync/SyncSessionFactoryImpl.java

@@ -5,8 +5,6 @@ import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.Priority;
-import org.briarproject.bramble.api.sync.PriorityHandler;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
 import org.briarproject.bramble.api.sync.SyncRecordReaderFactory;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
@@ -20,7 +18,6 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.concurrent.Executor;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
@@ -49,12 +46,10 @@ class SyncSessionFactoryImpl implements SyncSessionFactory {
 	}
 
 	@Override
-	public SyncSession createIncomingSession(ContactId c, InputStream in,
-			PriorityHandler handler) {
+	public SyncSession createIncomingSession(ContactId c, InputStream in) {
 		SyncRecordReader recordReader =
 				recordReaderFactory.createRecordReader(in);
-		return new IncomingSession(db, dbExecutor, eventBus, c, recordReader,
-				handler);
+		return new IncomingSession(db, dbExecutor, eventBus, c, recordReader);
 	}
 
 	@Override
@@ -69,12 +64,11 @@ class SyncSessionFactoryImpl implements SyncSessionFactory {
 
 	@Override
 	public SyncSession createDuplexOutgoingSession(ContactId c, int maxLatency,
-			int maxIdleTime, StreamWriter streamWriter,
-			@Nullable Priority priority) {
+			int maxIdleTime, StreamWriter streamWriter) {
 		OutputStream out = streamWriter.getOutputStream();
 		SyncRecordWriter recordWriter =
 				recordWriterFactory.createRecordWriter(out);
 		return new DuplexOutgoingSession(db, dbExecutor, eventBus, clock, c,
-				maxLatency, maxIdleTime, streamWriter, recordWriter, priority);
+				maxLatency, maxIdleTime, streamWriter, recordWriter);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/versioning/ClientVersioningManagerImpl.java

@@ -26,9 +26,7 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.validation.IncomingMessageHook;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientMajorVersion;
-import org.briarproject.bramble.api.versioning.ClientVersion;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
-import org.briarproject.bramble.api.versioning.event.ClientVersionUpdatedEvent;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -82,9 +80,9 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	@Override
 	public void registerClient(ClientId clientId, int majorVersion,
 			int minorVersion, ClientVersioningHook hook) {
-		ClientMajorVersion cmv = new ClientMajorVersion(clientId, majorVersion);
-		clients.add(new ClientVersion(cmv, minorVersion));
-		hooks.put(cmv, hook);
+		ClientMajorVersion cv = new ClientMajorVersion(clientId, majorVersion);
+		clients.add(new ClientVersion(cv, minorVersion));
+		hooks.put(cv, hook);
 	}
 
 	@Override
@@ -98,9 +96,9 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			Update remoteUpdate = loadUpdate(txn, latest.remote.messageId);
 			Map<ClientMajorVersion, Visibility> visibilities =
 					getVisibilities(localUpdate.states, remoteUpdate.states);
-			ClientMajorVersion key =
+			ClientMajorVersion cv =
 					new ClientMajorVersion(clientId, majorVersion);
-			Visibility v = visibilities.get(key);
+			Visibility v = visibilities.get(cv);
 			return v == null ? INVISIBLE : v;
 		} catch (FormatException e) {
 			throw new DbException(e);
@@ -114,11 +112,10 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			LatestUpdates latest = findLatestUpdates(txn, contactId);
 			if (latest == null || latest.remote == null) return -1;
 			Update remoteUpdate = loadUpdate(txn, latest.remote.messageId);
-			ClientMajorVersion key =
+			ClientMajorVersion cv =
 					new ClientMajorVersion(clientId, majorVersion);
 			for (ClientState remote : remoteUpdate.states) {
-				if (remote.clientVersion.getClientMajorVersion().equals(key))
-					return remote.clientVersion.getMinorVersion();
+				if (remote.majorVersion.equals(cv)) return remote.minorVersion;
 			}
 			return -1;
 		} catch (FormatException e) {
@@ -229,21 +226,9 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			Map<ClientMajorVersion, Visibility> after =
 					getVisibilities(newLocalStates, newRemoteStates);
 			// Call hooks for any visibilities that have changed
-			ContactId c = getContactId(txn, m.getGroupId());
 			if (!before.equals(after)) {
-				Contact contact = db.getContact(txn, c);
-				callVisibilityHooks(txn, contact, before, after);
-			}
-			// Broadcast events for any new client versions
-			Set<ClientVersion> oldRemoteVersions = new HashSet<>();
-			for (ClientState cs : oldRemoteStates) {
-				oldRemoteVersions.add(cs.clientVersion);
-			}
-			for (ClientState cs : newRemoteStates) {
-				if (!oldRemoteVersions.contains(cs.clientVersion)) {
-					txn.attach(new ClientVersionUpdatedEvent(c,
-							cs.clientVersion));
-				}
+				Contact c = getContact(txn, m.getGroupId());
+				callVisibilityHooks(txn, c, before, after);
 			}
 		} catch (FormatException e) {
 			throw new InvalidMessageException(e);
@@ -271,8 +256,8 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	}
 
 	private BdfList encodeClientVersion(ClientVersion cv) {
-		return BdfList.of(cv.getClientId().getString(), cv.getMajorVersion(),
-				cv.getMinorVersion());
+		return BdfList.of(cv.majorVersion.getClientId().getString(),
+				cv.majorVersion.getMajorVersion(), cv.minorVersion);
 	}
 
 	/**
@@ -313,7 +298,8 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			ClientId clientId = new ClientId(cv.getString(0));
 			int majorVersion = cv.getLong(1).intValue();
 			int minorVersion = cv.getLong(2).intValue();
-			parsed.add(new ClientVersion(clientId, majorVersion, minorVersion));
+			parsed.add(new ClientVersion(clientId, majorVersion,
+					minorVersion));
 		}
 		return parsed;
 	}
@@ -432,15 +418,13 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	private List<ClientState> updateStatesFromLocalVersions(
 			List<ClientState> oldStates, List<ClientVersion> newVersions) {
 		Map<ClientMajorVersion, ClientState> oldMap = new HashMap<>();
-		for (ClientState cs : oldStates) {
-			oldMap.put(cs.clientVersion.getClientMajorVersion(), cs);
-		}
+		for (ClientState cs : oldStates) oldMap.put(cs.majorVersion, cs);
 		List<ClientState> newStates = new ArrayList<>(newVersions.size());
 		for (ClientVersion newVersion : newVersions) {
-			ClientMajorVersion key = newVersion.getClientMajorVersion();
-			ClientState oldState = oldMap.get(key);
+			ClientState oldState = oldMap.get(newVersion.majorVersion);
 			boolean active = oldState != null && oldState.active;
-			newStates.add(new ClientState(newVersion, active));
+			newStates.add(new ClientState(newVersion.majorVersion,
+					newVersion.minorVersion, active));
 		}
 		return newStates;
 	}
@@ -467,25 +451,21 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	}
 
 	private BdfList encodeClientState(ClientState cs) {
-		ClientVersion cv = cs.clientVersion;
-		return BdfList.of(cv.getClientId().getString(), cv.getMajorVersion(),
-				cv.getMinorVersion(), cs.active);
+		return BdfList.of(cs.majorVersion.getClientId().getString(),
+				cs.majorVersion.getMajorVersion(), cs.minorVersion, cs.active);
 	}
 
 	private Map<ClientMajorVersion, Visibility> getVisibilities(
 			List<ClientState> localStates, List<ClientState> remoteStates) {
 		Map<ClientMajorVersion, ClientState> remoteMap = new HashMap<>();
-		for (ClientState cs : remoteStates) {
-			remoteMap.put(cs.clientVersion.getClientMajorVersion(), cs);
-		}
+		for (ClientState cs : remoteStates) remoteMap.put(cs.majorVersion, cs);
 		Map<ClientMajorVersion, Visibility> visibilities = new HashMap<>();
 		for (ClientState local : localStates) {
-			ClientMajorVersion key =
-					local.clientVersion.getClientMajorVersion();
-			ClientState remote = remoteMap.get(key);
-			if (remote == null) visibilities.put(key, INVISIBLE);
-			else if (remote.active) visibilities.put(key, SHARED);
-			else visibilities.put(key, VISIBLE);
+			ClientState remote = remoteMap.get(local.majorVersion);
+			if (remote == null) visibilities.put(local.majorVersion, INVISIBLE);
+			else if (remote.active)
+				visibilities.put(local.majorVersion, SHARED);
+			else visibilities.put(local.majorVersion, VISIBLE);
 		}
 		return visibilities;
 	}
@@ -506,9 +486,9 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		}
 	}
 
-	private void callVisibilityHook(Transaction txn, ClientMajorVersion cmv,
+	private void callVisibilityHook(Transaction txn, ClientMajorVersion cv,
 			Contact c, Visibility v) throws DbException {
-		ClientVersioningHook hook = hooks.get(cmv);
+		ClientVersioningHook hook = hooks.get(cv);
 		if (hook != null) hook.onClientVisibilityChanging(txn, c, v);
 	}
 
@@ -516,17 +496,18 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			List<ClientVersion> versions) throws DbException {
 		List<ClientState> states = new ArrayList<>(versions.size());
 		for (ClientVersion cv : versions) {
-			states.add(new ClientState(cv, false));
+			states.add(new ClientState(cv.majorVersion, cv.minorVersion,
+					false));
 		}
 		storeUpdate(txn, g, states, 1);
 	}
 
-	private ContactId getContactId(Transaction txn, GroupId g)
-			throws DbException {
+	private Contact getContact(Transaction txn, GroupId g) throws DbException {
 		try {
 			BdfDictionary meta =
 					clientHelper.getGroupMetadataAsDictionary(txn, g);
-			return new ContactId(meta.getLong(GROUP_KEY_CONTACT_ID).intValue());
+			int id = meta.getLong(GROUP_KEY_CONTACT_ID).intValue();
+			return db.getContact(txn, new ContactId(id));
 		} catch (FormatException e) {
 			throw new DbException(e);
 		}
@@ -535,16 +516,13 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	private List<ClientState> updateStatesFromRemoteStates(
 			List<ClientState> oldLocalStates, List<ClientState> remoteStates) {
 		Set<ClientMajorVersion> remoteSet = new HashSet<>();
-		for (ClientState cs : remoteStates) {
-			remoteSet.add(cs.clientVersion.getClientMajorVersion());
-		}
+		for (ClientState cs : remoteStates) remoteSet.add(cs.majorVersion);
 		List<ClientState> newLocalStates =
 				new ArrayList<>(oldLocalStates.size());
 		for (ClientState oldState : oldLocalStates) {
-			ClientMajorVersion cmv =
-					oldState.clientVersion.getClientMajorVersion();
-			boolean active = remoteSet.contains(cmv);
-			newLocalStates.add(new ClientState(oldState.clientVersion, active));
+			boolean active = remoteSet.contains(oldState.majorVersion);
+			newLocalStates.add(new ClientState(oldState.majorVersion,
+					oldState.minorVersion, active));
 		}
 		return newLocalStates;
 	}
@@ -583,19 +561,61 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		}
 	}
 
+	private static class ClientVersion implements Comparable<ClientVersion> {
+
+		private final ClientMajorVersion majorVersion;
+		private final int minorVersion;
+
+		private ClientVersion(ClientMajorVersion majorVersion,
+				int minorVersion) {
+			this.majorVersion = majorVersion;
+			this.minorVersion = minorVersion;
+		}
+
+		private ClientVersion(ClientId clientId, int majorVersion,
+				int minorVersion) {
+			this(new ClientMajorVersion(clientId, majorVersion), minorVersion);
+		}
+
+		@Override
+		public boolean equals(Object o) {
+			if (o instanceof ClientVersion) {
+				ClientVersion cv = (ClientVersion) o;
+				return majorVersion.equals(cv.majorVersion)
+						&& minorVersion == cv.minorVersion;
+			}
+			return false;
+		}
+
+		@Override
+		public int hashCode() {
+			return majorVersion.hashCode();
+		}
+
+		@Override
+		public int compareTo(ClientVersion cv) {
+			int compare = majorVersion.compareTo(cv.majorVersion);
+			if (compare != 0) return compare;
+			return minorVersion - cv.minorVersion;
+		}
+	}
+
 	private static class ClientState {
 
-		private final ClientVersion clientVersion;
+		private final ClientMajorVersion majorVersion;
+		private final int minorVersion;
 		private final boolean active;
 
-		private ClientState(ClientVersion clientVersion, boolean active) {
-			this.clientVersion = clientVersion;
+		private ClientState(ClientMajorVersion majorVersion, int minorVersion,
+				boolean active) {
+			this.majorVersion = majorVersion;
+			this.minorVersion = minorVersion;
 			this.active = active;
 		}
 
 		private ClientState(ClientId clientId, int majorVersion,
 				int minorVersion, boolean active) {
-			this(new ClientVersion(clientId, majorVersion, minorVersion),
+			this(new ClientMajorVersion(clientId, majorVersion), minorVersion,
 					active);
 		}
 
@@ -603,7 +623,8 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		public boolean equals(Object o) {
 			if (o instanceof ClientState) {
 				ClientState cs = (ClientState) o;
-				return clientVersion.equals(cs.clientVersion)
+				return majorVersion.equals(cs.majorVersion)
+						&& minorVersion == cs.minorVersion
 						&& active == cs.active;
 			}
 			return false;
@@ -611,7 +632,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 
 		@Override
 		public int hashCode() {
-			return clientVersion.hashCode();
+			return majorVersion.hashCode();
 		}
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/account/AccountManagerImplTest.java

@@ -1,8 +1,6 @@
 package org.briarproject.bramble.account;
 
 import org.briarproject.bramble.api.crypto.CryptoComponent;
-import org.briarproject.bramble.api.crypto.DecryptionException;
-import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.identity.Identity;
@@ -20,15 +18,12 @@ import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.nio.charset.Charset;
 
 import javax.annotation.Nullable;
 
 import static junit.framework.Assert.assertFalse;
 import static junit.framework.Assert.assertNull;
 import static junit.framework.Assert.assertTrue;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.INVALID_CIPHERTEXT;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.INVALID_PASSWORD;
 import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
 import static org.briarproject.bramble.test.TestUtils.getIdentity;
 import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
@@ -39,14 +34,11 @@ import static org.briarproject.bramble.util.StringUtils.toHexString;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.fail;
 
 public class AccountManagerImplTest extends BrambleMockTestCase {
 
 	private final DatabaseConfig databaseConfig =
 			context.mock(DatabaseConfig.class);
-	private final KeyStrengthener keyStrengthener =
-			context.mock(KeyStrengthener.class);
 	private final CryptoComponent crypto = context.mock(CryptoComponent.class);
 	private final IdentityManager identityManager =
 			context.mock(IdentityManager.class);
@@ -76,8 +68,6 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(dbDir));
 			allowing(databaseConfig).getDatabaseKeyDirectory();
 			will(returnValue(keyDir));
-			allowing(databaseConfig).getKeyStrengthener();
-			will(returnValue(keyStrengthener));
 		}});
 
 		accountManager =
@@ -88,13 +78,8 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testSignInThrowsExceptionIfDbKeyCannotBeLoaded() {
-		try {
-			accountManager.signIn(password);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_CIPHERTEXT, expected.getDecryptionResult());
-		}
+	public void testSignInReturnsFalseIfDbKeyCannotBeLoaded() {
+		assertFalse(accountManager.signIn(password));
 		assertFalse(accountManager.hasDatabaseKey());
 
 		assertFalse(keyFile.exists());
@@ -102,11 +87,10 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testSignInThrowsExceptionIfPasswordIsWrong() throws Exception {
+	public void testSignInReturnsFalseIfPasswordIsWrong() throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(crypto).decryptWithPassword(encryptedKey, password,
-					keyStrengthener);
-			will(throwException(new DecryptionException(INVALID_PASSWORD)));
+			oneOf(crypto).decryptWithPassword(encryptedKey, password);
+			will(returnValue(null));
 		}});
 
 		storeDatabaseKey(keyFile, encryptedKeyHex);
@@ -115,12 +99,7 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
 
-		try {
-			accountManager.signIn(password);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_PASSWORD, expected.getDecryptionResult());
-		}
+		assertFalse(accountManager.signIn(password));
 		assertFalse(accountManager.hasDatabaseKey());
 
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
@@ -130,11 +109,8 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testSignInReturnsTrueIfPasswordIsRight() throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(crypto).decryptWithPassword(encryptedKey, password,
-					keyStrengthener);
+			oneOf(crypto).decryptWithPassword(encryptedKey, password);
 			will(returnValue(key.getBytes()));
-			oneOf(crypto).isEncryptedWithStrengthenedKey(encryptedKey);
-			will(returnValue(true));
 		}});
 
 		storeDatabaseKey(keyFile, encryptedKeyHex);
@@ -143,7 +119,7 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
 
-		accountManager.signIn(password);
+		assertTrue(accountManager.signIn(password));
 		assertTrue(accountManager.hasDatabaseKey());
 		SecretKey decrypted = accountManager.getDatabaseKey();
 		assertNotNull(decrypted);
@@ -153,35 +129,6 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
 	}
 
-	@Test
-	public void testSignInReEncryptsKey() throws Exception {
-		context.checking(new Expectations() {{
-			oneOf(crypto).decryptWithPassword(encryptedKey, password,
-					keyStrengthener);
-			will(returnValue(key.getBytes()));
-			oneOf(crypto).isEncryptedWithStrengthenedKey(encryptedKey);
-			will(returnValue(false));
-			oneOf(crypto).encryptWithPassword(key.getBytes(), password,
-					keyStrengthener);
-			will(returnValue(newEncryptedKey));
-		}});
-
-		storeDatabaseKey(keyFile, encryptedKeyHex);
-		storeDatabaseKey(keyBackupFile, encryptedKeyHex);
-
-		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
-		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
-
-		accountManager.signIn(password);
-		assertTrue(accountManager.hasDatabaseKey());
-		SecretKey decrypted = accountManager.getDatabaseKey();
-		assertNotNull(decrypted);
-		assertArrayEquals(key.getBytes(), decrypted.getBytes());
-
-		assertEquals(newEncryptedKeyHex, loadDatabaseKey(keyFile));
-		assertEquals(newEncryptedKeyHex, loadDatabaseKey(keyBackupFile));
-	}
-
 	@Test
 	public void testDbKeyIsLoadedFromPrimaryFile() throws Exception {
 		storeDatabaseKey(keyFile, encryptedKeyHex);
@@ -254,6 +201,55 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 		assertFalse(keyBackupFile.exists());
 	}
 
+	@Test
+	public void testAccountExistsReturnsFalseIfDbDirectoryDoesNotExist()
+			throws Exception {
+		storeDatabaseKey(keyFile, encryptedKeyHex);
+		storeDatabaseKey(keyBackupFile, encryptedKeyHex);
+
+		assertFalse(dbDir.exists());
+
+		assertFalse(accountManager.accountExists());
+
+		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
+		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
+		assertFalse(dbDir.exists());
+	}
+
+	@Test
+	public void testAccountExistsReturnsFalseIfDbDirectoryIsNotDirectory()
+			throws Exception {
+		storeDatabaseKey(keyFile, encryptedKeyHex);
+		storeDatabaseKey(keyBackupFile, encryptedKeyHex);
+
+		assertTrue(dbDir.createNewFile());
+		assertFalse(dbDir.isDirectory());
+
+		assertFalse(accountManager.accountExists());
+
+		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
+		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
+		assertTrue(dbDir.exists());
+		assertFalse(dbDir.isDirectory());
+	}
+
+	@Test
+	public void testAccountExistsReturnsTrueIfDbDirectoryIsDirectory()
+			throws Exception {
+		storeDatabaseKey(keyFile, encryptedKeyHex);
+		storeDatabaseKey(keyBackupFile, encryptedKeyHex);
+
+		assertTrue(dbDir.mkdirs());
+		assertTrue(dbDir.isDirectory());
+
+		assertTrue(accountManager.accountExists());
+
+		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
+		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
+		assertTrue(dbDir.exists());
+		assertTrue(dbDir.isDirectory());
+	}
+
 	@Test
 	public void testCreateAccountStoresDbKey() throws Exception {
 		context.checking(new Expectations() {{
@@ -262,8 +258,7 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 			oneOf(identityManager).registerIdentity(identity);
 			oneOf(crypto).generateSecretKey();
 			will(returnValue(key));
-			oneOf(crypto).encryptWithPassword(key.getBytes(), password,
-					keyStrengthener);
+			oneOf(crypto).encryptWithPassword(key.getBytes(), password);
 			will(returnValue(encryptedKey));
 		}});
 
@@ -281,36 +276,25 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testChangePasswordThrowsExceptionIfDbKeyCannotBeLoaded() {
-		try {
-			accountManager.changePassword(password, newPassword);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_CIPHERTEXT, expected.getDecryptionResult());
-		}
+	public void testChangePasswordReturnsFalseIfDbKeyCannotBeLoaded() {
+		assertFalse(accountManager.changePassword(password, newPassword));
 
 		assertFalse(keyFile.exists());
 		assertFalse(keyBackupFile.exists());
 	}
 
 	@Test
-	public void testChangePasswordThrowsExceptionIfPasswordIsWrong()
+	public void testChangePasswordReturnsFalseIfPasswordIsWrong()
 			throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(crypto).decryptWithPassword(encryptedKey, password,
-					keyStrengthener);
-			will(throwException(new DecryptionException(INVALID_PASSWORD)));
+			oneOf(crypto).decryptWithPassword(encryptedKey, password);
+			will(returnValue(null));
 		}});
 
 		storeDatabaseKey(keyFile, encryptedKeyHex);
 		storeDatabaseKey(keyBackupFile, encryptedKeyHex);
 
-		try {
-			accountManager.changePassword(password, newPassword);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_PASSWORD, expected.getDecryptionResult());
-		}
+		assertFalse(accountManager.changePassword(password, newPassword));
 
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
@@ -320,20 +304,16 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	public void testChangePasswordReturnsTrueIfPasswordIsRight()
 			throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(crypto).decryptWithPassword(encryptedKey, password,
-					keyStrengthener);
+			oneOf(crypto).decryptWithPassword(encryptedKey, password);
 			will(returnValue(key.getBytes()));
-			oneOf(crypto).isEncryptedWithStrengthenedKey(encryptedKey);
-			will(returnValue(true));
-			oneOf(crypto).encryptWithPassword(key.getBytes(), newPassword,
-					keyStrengthener);
+			oneOf(crypto).encryptWithPassword(key.getBytes(), newPassword);
 			will(returnValue(newEncryptedKey));
 		}});
 
 		storeDatabaseKey(keyFile, encryptedKeyHex);
 		storeDatabaseKey(keyBackupFile, encryptedKeyHex);
 
-		accountManager.changePassword(password, newPassword);
+		assertTrue(accountManager.changePassword(password, newPassword));
 
 		assertEquals(newEncryptedKeyHex, loadDatabaseKey(keyFile));
 		assertEquals(newEncryptedKeyHex, loadDatabaseKey(keyBackupFile));
@@ -342,7 +322,7 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	private void storeDatabaseKey(File f, String hex) throws IOException {
 		f.getParentFile().mkdirs();
 		FileOutputStream out = new FileOutputStream(f);
-		out.write(hex.getBytes(Charset.forName("UTF-8")));
+		out.write(hex.getBytes("UTF-8"));
 		out.flush();
 		out.close();
 	}
@@ -350,7 +330,7 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	@Nullable
 	private String loadDatabaseKey(File f) throws IOException {
 		BufferedReader reader = new BufferedReader(new InputStreamReader(
-				new FileInputStream(f), Charset.forName("UTF-8")));
+				new FileInputStream(f), "UTF-8"));
 		String hex = reader.readLine();
 		reader.close();
 		return hex;

bramble-core/src/test/java/org/briarproject/bramble/connection/ConnectionRegistryImplTest.java

@@ -1,600 +0,0 @@
-package org.briarproject.bramble.connection;
-
-import org.briarproject.bramble.api.connection.ConnectionRegistry;
-import org.briarproject.bramble.api.connection.InterruptibleConnection;
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.PendingContactId;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.plugin.PluginConfig;
-import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
-import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
-import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
-import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionClosedEvent;
-import org.briarproject.bramble.api.rendezvous.event.RendezvousConnectionOpenedEvent;
-import org.briarproject.bramble.api.sync.Priority;
-import org.briarproject.bramble.test.BrambleMockTestCase;
-import org.jmock.Expectations;
-import org.junit.Test;
-
-import java.util.Collection;
-
-import static java.util.Collections.emptyList;
-import static java.util.Collections.emptyMap;
-import static java.util.Collections.singletonList;
-import static java.util.Collections.singletonMap;
-import static org.briarproject.bramble.test.TestUtils.getContactId;
-import static org.briarproject.bramble.test.TestUtils.getRandomId;
-import static org.briarproject.bramble.test.TestUtils.getTransportId;
-import static org.briarproject.bramble.util.StringUtils.fromHexString;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
-
-public class ConnectionRegistryImplTest extends BrambleMockTestCase {
-
-	private final EventBus eventBus = context.mock(EventBus.class);
-	private final PluginConfig pluginConfig = context.mock(PluginConfig.class);
-	private final InterruptibleConnection conn1 =
-			context.mock(InterruptibleConnection.class, "conn1");
-	private final InterruptibleConnection conn2 =
-			context.mock(InterruptibleConnection.class, "conn2");
-	private final InterruptibleConnection conn3 =
-			context.mock(InterruptibleConnection.class, "conn3");
-
-	private final ContactId contactId1 = getContactId();
-	private final ContactId contactId2 = getContactId();
-	private final TransportId transportId1 = getTransportId();
-	private final TransportId transportId2 = getTransportId();
-	private final TransportId transportId3 = getTransportId();
-	private final PendingContactId pendingContactId =
-			new PendingContactId(getRandomId());
-
-	private final Priority low =
-			new Priority(fromHexString("00000000000000000000000000000000"));
-	private final Priority high =
-			new Priority(fromHexString("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF"));
-
-	@Test
-	public void testRegisterMultipleConnections() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// The registry should be empty
-		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId1));
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId2));
-		assertEquals(emptyList(), c.getConnectedContacts(transportId3));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId3));
-
-		// Check that a registered connection shows up - this should
-		// broadcast a ConnectionOpenedEvent and a ContactConnectedEvent
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn1, true);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Register another connection with the same contact and transport -
-		// this should broadcast a ConnectionOpenedEvent and lookup should be
-		// unaffected
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn2, true);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Unregister one of the connections - this should broadcast a
-		// ConnectionClosedEvent and lookup should be unaffected
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
-		}});
-		c.unregisterConnection(contactId1, transportId1, conn1, true, false);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Unregister the other connection - this should broadcast a
-		// ConnectionClosedEvent and a ContactDisconnectedEvent
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(
-					ContactDisconnectedEvent.class)));
-		}});
-		c.unregisterConnection(contactId1, transportId1, conn2, true, false);
-		context.assertIsSatisfied();
-
-		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId1));
-
-		// Try to unregister the connection again - exception should be thrown
-		try {
-			c.unregisterConnection(contactId1, transportId1, conn2,
-					true, false);
-			fail();
-		} catch (IllegalArgumentException expected) {
-			// Expected
-		}
-	}
-
-	@Test
-	public void testRegisterMultipleContacts() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Register two contacts with one transport, then one of the contacts
-		// with a second transport - this should broadcast three
-		// ConnectionOpenedEvents and two ContactConnectedEvents
-		context.checking(new Expectations() {{
-			exactly(3).of(eventBus).broadcast(with(any(
-					ConnectionOpenedEvent.class)));
-			exactly(2).of(eventBus).broadcast(with(any(
-					ContactConnectedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn1, true);
-		c.registerConnection(contactId2, transportId1, conn2, true);
-		c.registerConnection(contactId2, transportId2, conn3, true);
-		context.assertIsSatisfied();
-
-		Collection<ContactId> connected = c.getConnectedContacts(transportId1);
-		assertEquals(2, connected.size());
-		assertTrue(connected.contains(contactId1));
-		assertTrue(connected.contains(contactId2));
-
-		connected = c.getConnectedOrBetterContacts(transportId1);
-		assertEquals(2, connected.size());
-		assertTrue(connected.contains(contactId1));
-		assertTrue(connected.contains(contactId2));
-
-		assertEquals(singletonList(contactId2),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId2),
-				c.getConnectedOrBetterContacts(transportId2));
-	}
-
-	@Test
-	public void testConnectionsAreNotInterruptedUnlessPriorityIsSet() {
-		// Prefer transport 2 to transport 1
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(
-					singletonMap(transportId1, singletonList(transportId2))));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Connect via transport 1 (worse than 2) and set priority to low
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn1, true);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 2 (better than 1) and set priority to high -
-		// the old connection should not be interrupted, despite using a worse
-		// transport, to remain compatible with old peers
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId2, conn2, true);
-		c.setPriority(contactId1, transportId2, conn2, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 3 (no preference) and set priority to high -
-		// again, no interruptions are expected
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId3, conn3, true);
-		c.setPriority(contactId1, transportId3, conn3, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-	}
-
-	@Test
-	public void testNewConnectionIsInterruptedIfOldConnectionUsesBetterTransport() {
-		// Prefer transport 1 to transport 2
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(
-					singletonMap(transportId2, singletonList(transportId1))));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Connect via transport 1 (better than 2) and set priority to low
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn1, true);
-		c.setPriority(contactId1, transportId1, conn1, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// The contact is not connected via transport 2 but is connected via a
-		// better transport
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 2 (worse than 1) and set priority to high -
-		// the new connection should be interrupted because it uses a worse
-		// transport
-		context.checking(new Expectations() {{
-			oneOf(conn2).interruptOutgoingSession();
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId2, conn2, true);
-		c.setPriority(contactId1, transportId2, conn2, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 3 (no preference) and set priority to low -
-		// no further interruptions
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId3, conn3, true);
-		c.setPriority(contactId1, transportId3, conn3, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-
-		// Unregister the interrupted connection (transport 2)
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
-		}});
-		c.unregisterConnection(contactId1, transportId2, conn2, true, false);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// The contact is not connected via transport 2 but is connected via a
-		// better transport
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-	}
-
-	@Test
-	public void testOldConnectionIsInterruptedIfNewConnectionUsesBetterTransport() {
-		// Prefer transport 2 to transport 1
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(
-					singletonMap(transportId1, singletonList(transportId2))));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Connect via transport 1 (worse than 2) and set priority to high
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn1, true);
-		c.setPriority(contactId1, transportId1, conn1, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(emptyList(), c.getConnectedContacts(transportId2));
-		assertEquals(emptyList(), c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 2 (better than 1) and set priority to low -
-		// the old connection should be interrupted because it uses a worse
-		// transport
-		context.checking(new Expectations() {{
-			oneOf(conn1).interruptOutgoingSession();
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId2, conn2, true);
-		c.setPriority(contactId1, transportId2, conn2, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		// Connect via transport 3 (no preference) and set priority to high -
-		// no further interruptions
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId3, conn3, true);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-
-		// Unregister the interrupted connection (transport 1)
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
-		}});
-		c.unregisterConnection(contactId1, transportId1, conn1, true, false);
-		context.assertIsSatisfied();
-
-		// The contact is not connected via transport 1 but is connected via a
-		// better transport
-		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId2));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId2));
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId3));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId3));
-	}
-
-	@Test
-	public void testNewConnectionIsInterruptedIfOldConnectionHasHigherPriority() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Register a connection with high priority
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn1, true);
-		c.setPriority(contactId1, transportId1, conn1, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Register another connection via the same transport (no priority yet)
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn2, true);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Set the priority of the second connection to low - the second
-		// connection should be interrupted
-		context.checking(new Expectations() {{
-			oneOf(conn2).interruptOutgoingSession();
-		}});
-		c.setPriority(contactId1, transportId1, conn2, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Register a third connection with low priority - it should also be
-		// interrupted
-		context.checking(new Expectations() {{
-			oneOf(conn3).interruptOutgoingSession();
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn3, true);
-		c.setPriority(contactId1, transportId1, conn3, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-	}
-
-	@Test
-	public void testOldConnectionIsInterruptedIfNewConnectionHasHigherPriority() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		// Register a connection with low priority
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn1, true);
-		c.setPriority(contactId1, transportId1, conn1, low);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Register another connection via the same transport (no priority yet)
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-		}});
-		c.registerConnection(contactId1, transportId1, conn2, true);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-
-		// Set the priority of the second connection to high - the first
-		// connection should be interrupted
-		context.checking(new Expectations() {{
-			oneOf(conn1).interruptOutgoingSession();
-		}});
-		c.setPriority(contactId1, transportId1, conn2, high);
-		context.assertIsSatisfied();
-
-		assertEquals(singletonList(contactId1),
-				c.getConnectedContacts(transportId1));
-		assertEquals(singletonList(contactId1),
-				c.getConnectedOrBetterContacts(transportId1));
-	}
-
-	@Test
-	public void testRegisterAndUnregisterPendingContacts() {
-		context.checking(new Expectations() {{
-			allowing(pluginConfig).getTransportPreferences();
-			will(returnValue(emptyMap()));
-		}});
-
-		ConnectionRegistry c =
-				new ConnectionRegistryImpl(eventBus, pluginConfig);
-
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(
-					RendezvousConnectionOpenedEvent.class)));
-		}});
-		assertTrue(c.registerConnection(pendingContactId));
-		assertFalse(c.registerConnection(pendingContactId)); // Redundant
-		context.assertIsSatisfied();
-
-		context.checking(new Expectations() {{
-			oneOf(eventBus).broadcast(with(any(
-					RendezvousConnectionClosedEvent.class)));
-		}});
-		c.unregisterConnection(pendingContactId, true);
-		context.assertIsSatisfied();
-
-		try {
-			c.unregisterConnection(pendingContactId, true);
-			fail();
-		} catch (IllegalArgumentException expected) {
-			// Expected
-		}
-	}
-}