DO NOT MERGE: Delay sending of attachments.

and display attachments as they arrive while ImageActivity is open.

bramble-android/build.gradle

@@ -11,8 +11,8 @@ android {
 	defaultConfig {
 		minSdkVersion 16
 		targetSdkVersion 28
-		versionCode 10207
+		versionCode 10205
-		versionName "1.2.7"
+		versionName "1.2.5"
 		consumerProguardFiles 'proguard-rules.txt'
 
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -38,7 +38,7 @@ configurations {
 
 dependencies {
 	implementation project(path: ':bramble-core', configuration: 'default')
-	tor 'org.briarproject:tor-android:0.3.5.10@zip'
+	tor 'org.briarproject:tor-android:0.3.5.9@zip'
 	tor 'org.briarproject:obfs4proxy-android:0.0.11-2@zip'
 
 	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'

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

@@ -12,7 +12,6 @@ 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;
 
@@ -21,7 +20,6 @@ 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;
@@ -32,12 +30,6 @@ 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");
-
 	protected final Context appContext;
 	private final SharedPreferences prefs;
 
@@ -89,7 +81,7 @@ class AndroidAccountManager extends AccountManagerImpl
 			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 +90,14 @@ 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 +109,12 @@ 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) ||
+			return WIFI_AP_STATE_CHANGED_ACTION.equals(action);
-					WIFI_P2P_THIS_DEVICE_CHANGED_ACTION.equals(action);
 		}
 	}
 }

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

@@ -24,6 +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;
@@ -46,10 +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;
@@ -242,15 +240,11 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 						break;
 					} else if (ACTION_FOUND.equals(action)) {
 						BluetoothDevice d = i.getParcelableExtra(EXTRA_DEVICE);
-						// Ignore Bluetooth LE devices
+						String address = d.getAddress();
-						if (SDK_INT < 18 || d.getType() != DEVICE_TYPE_LE) {
+						if (LOG.isLoggable(INFO))
-							String address = d.getAddress();
+							LOG.info("Discovered " + scrubMacAddress(address));
-							if (LOG.isLoggable(INFO))
+						if (!addresses.contains(address))
-								LOG.info("Discovered " +
+							addresses.add(address);
-										scrubMacAddress(address));
-							if (!addresses.contains(address))
-								addresses.add(address);
-						}
 					}
 					now = clock.currentTimeMillis();
 				}
@@ -266,7 +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/AndroidBluetoothTransportConnection.java

@@ -10,9 +10,6 @@ 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 {
@@ -26,8 +23,6 @@ class AndroidBluetoothTransportConnection
 		super(plugin);
 		this.connectionManager = connectionManager;
 		this.socket = socket;
-		String address = socket.getRemoteDevice().getAddress();
-		if (isValidBluetoothAddress(address)) remote.put(PROP_ADDRESS, address);
 	}
 
 	@Override

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) {
+			int maxIdleTime) {
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
+		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
-				connectionTimeout);
 		// 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 (super.getLocalIpAddresses().contains(WIFI_AP_ADDRESS))
-			if (addr.equals(WIFI_AP_ADDRESS)) return singletonList(addr);
+			return singletonList(WIFI_AP_ADDRESS);
-			if (addr.equals(WIFI_DIRECT_AP_ADDRESS)) return singletonList(addr);
-		}
 		// 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();
+			Collection<InetAddress> addrs = getLocalIpAddresses();
-			if (addrs.contains(WIFI_AP_ADDRESS)
+			if (addrs.contains(WIFI_AP_ADDRESS)) {
-					|| addrs.contains(WIFI_DIRECT_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_LATENCY = 30 * 1000; // 30 seconds
-	private static final int MAX_IDLE_TIME = 30_000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
-	private static final int CONNECTION_TIMEOUT = 3_000; // 3 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
-	private static final int MIN_POLLING_INTERVAL = 60_000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
-	private static final int MAX_POLLING_INTERVAL = 600_000; // 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,
+				appContext, backoff, callback, MAX_LATENCY, MAX_IDLE_TIME);
-				CONNECTION_TIMEOUT);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

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

@@ -71,7 +71,7 @@ public class AndroidUtils {
 		return new Pair<>("", "");
 	}
 
-	public static boolean isValidBluetoothAddress(@Nullable String address) {
+	private static boolean isValidBluetoothAddress(@Nullable String address) {
 		return !StringUtils.isNullOrEmpty(address)
 				&& BluetoothAdapter.checkBluetoothAddress(address)
 				&& !address.equals(FAKE_BLUETOOTH_ADDRESS);

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

@@ -72,9 +72,7 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 	@Test
 	public void testDeleteAccountClearsSharedPrefsAndDeletesFiles()
 			throws Exception {
-		// Directories 'code_cache', 'lib' and 'shared_prefs' should be spared
+		// Directories 'lib' and 'shared_prefs' should be spared
-		File codeCacheDir = new File(testDir, "code_cache");
-		File codeCacheFile = new File(codeCacheDir, "file");
 		File libDir = new File(testDir, "lib");
 		File libFile = new File(libDir, "file");
 		File sharedPrefsDir = new File(testDir, "shared_prefs");
@@ -113,8 +111,6 @@ 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 +126,6 @@ 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

@@ -70,7 +70,7 @@ dependencyVerification {
         '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:tor-android:0.3.5.9:tor-android-0.3.5.9.zip:853b0440feccd6904bd03e6b2de53a62ebcde1d58068beeadc447a7dff950bc8',
         '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',

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
+	 * or {@link #signIn(String)} has returned true, until the process exits.
-	 * {@link #deleteAccount()} is called or 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
+	 * returned true, until the process exits.
-	 * 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
+	 * given password and stores it on disk.
-	 * return true after this method returns true.
+	 * <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
+	 * @return true if the database key was successfully loaded and decrypted.
-	 * 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
+	 * @return true if the database key was successfully loaded, re-encrypted
-	 * decrypted.
+	 * and stored.
 	 */
-	void changePassword(String oldPassword, String newPassword)
+	boolean changePassword(String oldPassword, String newPassword);
-			throws DecryptionException;
 }

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

@@ -142,17 +142,16 @@ public interface CryptoComponent {
 	/**
 	 * Decrypts and authenticates the given ciphertext that has been read from
 	 * storage. The encryption and authentication keys are derived from the
-	 * given password.
+	 * given password. Returns null if the ciphertext cannot be decrypted and
+	 * authenticated (for example, if the password is wrong).
 	 *
 	 * @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
-	 * authenticated (for example, if the password is wrong).
 	 */
+	@Nullable
 	byte[] decryptWithPassword(byte[] ciphertext, String password,
-			@Nullable KeyStrengthener keyStrengthener)
+			@Nullable KeyStrengthener keyStrengthener);
-			throws DecryptionException;
 
 	/**
 	 * Returns true if the given ciphertext was encrypted using a strengthened

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/plugin/ConnectionRegistry.java

@@ -5,7 +5,8 @@ import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
 import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+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;
 
@@ -20,15 +21,15 @@ public interface ConnectionRegistry {
 	/**
 	 * Registers a connection with the given contact over the given transport.
 	 * Broadcasts {@link ConnectionOpenedEvent}. Also broadcasts
-	 * {@link ConnectionStatusChangedEvent} if this is the only connection with
+	 * {@link ContactConnectedEvent} if this is the only connection with the
-	 * the contact.
+	 * contact.
 	 */
 	void registerConnection(ContactId c, TransportId t, boolean incoming);
 
 	/**
 	 * Unregisters a connection with the given contact over the given transport.
 	 * Broadcasts {@link ConnectionClosedEvent}. Also broadcasts
-	 * {@link ConnectionStatusChangedEvent} if this is the only connection with
+	 * {@link ContactDisconnectedEvent} if this is the only connection with
 	 * the contact.
 	 */
 	void unregisterConnection(ContactId c, TransportId t, boolean incoming);
@@ -44,9 +45,9 @@ public interface ConnectionRegistry {
 	boolean isConnected(ContactId c, TransportId t);
 
 	/**
-	 * Returns the connection status of the given contact via all transports.
+	 * Returns true if the given contact is connected via any transport.
 	 */
-	ConnectionStatus getConnectionStatus(ContactId c);
+	boolean isConnected(ContactId c);
 
 	/**
 	 * Registers a connection with the given pending contact. Broadcasts

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

@@ -1,5 +0,0 @@
-package org.briarproject.bramble.api.plugin;
-
-public enum ConnectionStatus {
-	CONNECTED, RECENTLY_CONNECTED, DISCONNECTED
-}

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/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/ContactConnectedEvent.java

@@ -3,31 +3,24 @@ package org.briarproject.bramble.api.plugin.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.plugin.ConnectionStatus;
 
 import javax.annotation.concurrent.Immutable;
 
 /**
- * An event that is broadcast when a contact's connection status changes.
+ * An event that is broadcast when a contact connects that was not previously
+ * connected via any transport.
  */
 @Immutable
 @NotNullByDefault
-public class ConnectionStatusChangedEvent extends Event {
+public class ContactConnectedEvent extends Event {
 
 	private final ContactId contactId;
-	private final ConnectionStatus status;
 
-	public ConnectionStatusChangedEvent(ContactId contactId,
+	public ContactConnectedEvent(ContactId contactId) {
-			ConnectionStatus status) {
 		this.contactId = contactId;
-		this.status = status;
 	}
 
 	public ContactId getContactId() {
 		return contactId;
 	}
-
-	public ConnectionStatus getConnectionStatus() {
-		return status;
-	}
 }

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

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api.plugin.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a contact disconnects and is no longer
+ * connected via any transport.
+ */
+@Immutable
+@NotNullByDefault
+public class ContactDisconnectedEvent extends Event {
+
+	private final ContactId contactId;
+
+	public ContactDisconnectedEvent(ContactId contactId) {
+		this.contactId = contactId;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+}

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

@@ -2,7 +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;
@@ -18,7 +17,6 @@ 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;
@@ -26,7 +24,6 @@ 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;
@@ -98,7 +95,7 @@ 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;
@@ -150,7 +147,7 @@ class AccountManagerImpl implements AccountManager {
 	@GuardedBy("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 +155,8 @@ class AccountManagerImpl implements AccountManager {
 	@Override
 	public boolean accountExists() {
 		synchronized (stateChangeLock) {
-			return loadEncryptedDatabaseKey() != null;
+			return loadEncryptedDatabaseKey() != null
+					&& databaseConfig.getDatabaseDirectory().isDirectory();
 		}
 	}
 
@@ -195,24 +193,31 @@ 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)
+	@Nullable
-			throws DecryptionException {
+	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);
+		if (plaintext == null) {
+			LOG.info("Failed to decrypt database key");
+			return null;
+		}
 		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
@@ -225,11 +230,10 @@ class AccountManagerImpl implements AccountManager {
 	}
 
 	@Override
-	public void changePassword(String oldPassword, String newPassword)
+	public boolean changePassword(String oldPassword, String newPassword) {
-			throws DecryptionException {
 		synchronized (stateChangeLock) {
 			SecretKey key = loadAndDecryptDatabaseKey(oldPassword);
-			encryptAndStoreDatabaseKey(key, newPassword);
+			return key != null && encryptAndStoreDatabaseKey(key, newPassword);
 		}
 	}
 }

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

@@ -7,7 +7,6 @@ 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;
@@ -40,9 +39,6 @@ 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;
@@ -363,17 +359,16 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
+	@Nullable
 	public byte[] decryptWithPassword(byte[] input, String password,
-			@Nullable KeyStrengthener keyStrengthener)
+			@Nullable KeyStrengthener keyStrengthener) {
-			throws DecryptionException {
 		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) {
+				+ STORAGE_IV_BYTES + macBytes)
-			throw new DecryptionException(INVALID_CIPHERTEXT);
+			return null; // Invalid input
-		}
 		int inputOff = 0;
 		// Format version
 		byte formatVersion = input[inputOff];
@@ -381,7 +376,7 @@ class CryptoComponentImpl implements CryptoComponent {
 		// Check whether we support this format version
 		if (formatVersion != PBKDF_FORMAT_SCRYPT &&
 				formatVersion != PBKDF_FORMAT_SCRYPT_STRENGTHENED) {
-			throw new DecryptionException(INVALID_CIPHERTEXT);
+			return null;
 		}
 		// Salt
 		byte[] salt = new byte[PBKDF_SALT_BYTES];
@@ -390,9 +385,8 @@ class CryptoComponentImpl implements CryptoComponent {
 		// Cost parameter
 		long cost = ByteUtils.readUint32(input, inputOff);
 		inputOff += INT_32_BYTES;
-		if (cost < 2 || cost > Integer.MAX_VALUE) {
+		if (cost < 2 || cost > Integer.MAX_VALUE)
-			throw new DecryptionException(INVALID_CIPHERTEXT);
+			return null; // Invalid cost parameter
-		}
 		// IV
 		byte[] iv = new byte[STORAGE_IV_BYTES];
 		arraycopy(input, inputOff, iv, 0, iv.length);
@@ -400,10 +394,8 @@ class CryptoComponentImpl implements CryptoComponent {
 		// Derive the decryption key from the password
 		SecretKey key = passwordBasedKdf.deriveKey(password, salt, (int) cost);
 		if (formatVersion == PBKDF_FORMAT_SCRYPT_STRENGTHENED) {
-			if (keyStrengthener == null || !keyStrengthener.isInitialised()) {
+			if (keyStrengthener == null || !keyStrengthener.isInitialised())
-				// Can't derive the same strengthened key
+				return null; // Can't derive the same strengthened key
-				throw new DecryptionException(KEY_STRENGTHENER_ERROR);
-			}
 			key = keyStrengthener.strengthenKey(key);
 		}
 		// Initialise the cipher
@@ -419,7 +411,7 @@ 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
 		}
 	}
 

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 = !config.getDatabaseDirectory().mkdirs();
-		boolean reopen = isNonEmptyDirectory(dir);
-		if (LOG.isLoggable(INFO)) LOG.info("Reopening DB: " + reopen);
-		if (!reopen && dir.mkdirs()) LOG.info("Created database directory");
 		super.open("org.hsqldb.jdbc.JDBCDriver", reopen, key, listener);
 		return reopen;
 	}

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

@@ -15,8 +15,6 @@ 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.SyncSession;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
@@ -54,7 +52,6 @@ class ConnectionManagerImpl implements ConnectionManager {
 	private final HandshakeManager handshakeManager;
 	private final ContactExchangeManager contactExchangeManager;
 	private final ConnectionRegistry connectionRegistry;
-	private final TransportPropertyManager transportPropertyManager;
 
 	@Inject
 	ConnectionManagerImpl(@IoExecutor Executor ioExecutor,
@@ -63,8 +60,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 			SyncSessionFactory syncSessionFactory,
 			HandshakeManager handshakeManager,
 			ContactExchangeManager contactExchangeManager,
-			ConnectionRegistry connectionRegistry,
+			ConnectionRegistry connectionRegistry) {
-			TransportPropertyManager transportPropertyManager) {
 		this.ioExecutor = ioExecutor;
 		this.keyManager = keyManager;
 		this.streamReaderFactory = streamReaderFactory;
@@ -73,7 +69,6 @@ class ConnectionManagerImpl implements ConnectionManager {
 		this.handshakeManager = handshakeManager;
 		this.contactExchangeManager = contactExchangeManager;
 		this.connectionRegistry = connectionRegistry;
-		this.transportPropertyManager = transportPropertyManager;
 	}
 
 	@Override
@@ -274,7 +269,6 @@ class ConnectionManagerImpl implements ConnectionManager {
 		private final TransportId transportId;
 		private final TransportConnectionReader reader;
 		private final TransportConnectionWriter writer;
-		private final TransportProperties remote;
 
 		@Nullable
 		private volatile SyncSession outgoingSession = null;
@@ -284,7 +278,6 @@ class ConnectionManagerImpl implements ConnectionManager {
 			this.transportId = transportId;
 			reader = connection.getReader();
 			writer = connection.getWriter();
-			remote = connection.getRemoteProperties();
 		}
 
 		@Override
@@ -320,16 +313,13 @@ class ConnectionManagerImpl implements ConnectionManager {
 			// 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);
 				// 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 (DbException | IOException e) {
+			} catch (IOException e) {
 				logException(LOG, WARNING, e);
 				onReadError(true);
 			} finally {
@@ -385,7 +375,6 @@ class ConnectionManagerImpl implements ConnectionManager {
 		private final TransportId transportId;
 		private final TransportConnectionReader reader;
 		private final TransportConnectionWriter writer;
-		private final TransportProperties remote;
 
 		@Nullable
 		private volatile SyncSession outgoingSession = null;
@@ -396,7 +385,6 @@ class ConnectionManagerImpl implements ConnectionManager {
 			this.transportId = transportId;
 			reader = connection.getReader();
 			writer = connection.getWriter();
-			remote = connection.getRemoteProperties();
 		}
 
 		@Override
@@ -473,16 +461,13 @@ class ConnectionManagerImpl implements ConnectionManager {
 			connectionRegistry.registerConnection(contactId, transportId,
 					false);
 			try {
-				// Store any transport properties discovered from the connection
-				transportPropertyManager.addRemotePropertiesFromConnection(
-						contactId, transportId, remote);
 				// 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 (DbException | IOException e) {
+			} catch (IOException e) {
 				logException(LOG, WARNING, e);
 				onReadError();
 			} finally {

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

@@ -6,41 +6,30 @@ 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.ConnectionStatus;
 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.ConnectionStatusChangedEvent;
+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.system.Clock;
-import org.briarproject.bramble.api.system.Scheduler;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
-import java.util.concurrent.ScheduledExecutorService;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.GuardedBy;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
-import static java.util.Collections.emptyList;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static java.util.concurrent.TimeUnit.MINUTES;
-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.api.plugin.ConnectionStatus.CONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.DISCONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.RECENTLY_CONNECTED;
 
 @ThreadSafe
 @NotNullByDefault
@@ -49,30 +38,22 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 	private static final Logger LOG =
 			getLogger(ConnectionRegistryImpl.class.getName());
 
-	private static final long RECENTLY_CONNECTED_MS = MINUTES.toMillis(1);
-	private static final long EXPIRY_INTERVAL_MS = SECONDS.toMillis(10);
-
 	private final EventBus eventBus;
-	private final Clock clock;
 
 	private final Object lock = new Object();
 	@GuardedBy("lock")
 	private final Map<TransportId, Multiset<ContactId>> contactConnections;
 	@GuardedBy("lock")
-	private final Map<ContactId, Counter> contactCounts;
+	private final Multiset<ContactId> contactCounts;
 	@GuardedBy("lock")
 	private final Set<PendingContactId> connectedPendingContacts;
 
 	@Inject
-	ConnectionRegistryImpl(EventBus eventBus, Clock clock,
+	ConnectionRegistryImpl(EventBus eventBus) {
-			@Scheduler ScheduledExecutorService scheduler) {
 		this.eventBus = eventBus;
-		this.clock = clock;
 		contactConnections = new HashMap<>();
-		contactCounts = new HashMap<>();
+		contactCounts = new Multiset<>();
 		connectedPendingContacts = new HashSet<>();
-		scheduler.scheduleWithFixedDelay(this::expireRecentConnections,
-				EXPIRY_INTERVAL_MS, EXPIRY_INTERVAL_MS, MILLISECONDS);
 	}
 
 	@Override
@@ -90,22 +71,12 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 				contactConnections.put(t, m);
 			}
 			m.add(c);
-
+			if (contactCounts.add(c) == 1) firstConnection = true;
-			Counter counter = contactCounts.get(c);
-			if (counter == null) {
-				counter = new Counter();
-				contactCounts.put(c, counter);
-			}
-			if (counter.connections == 0) {
-				counter.disconnectedTime = 0;
-				firstConnection = true;
-			}
-			counter.connections++;
 		}
 		eventBus.broadcast(new ConnectionOpenedEvent(c, t, incoming));
 		if (firstConnection) {
 			LOG.info("Contact connected");
-			eventBus.broadcast(new ConnectionStatusChangedEvent(c, CONNECTED));
+			eventBus.broadcast(new ContactConnectedEvent(c));
 		}
 	}
 
@@ -122,22 +93,12 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 			if (m == null || !m.contains(c))
 				throw new IllegalArgumentException();
 			m.remove(c);
-
+			if (contactCounts.remove(c) == 0) lastConnection = true;
-			Counter counter = contactCounts.get(c);
-			if (counter == null || counter.connections == 0) {
-				throw new IllegalArgumentException();
-			}
-			counter.connections--;
-			if (counter.connections == 0) {
-				counter.disconnectedTime = clock.currentTimeMillis();
-				lastConnection = true;
-			}
 		}
 		eventBus.broadcast(new ConnectionClosedEvent(c, t, incoming));
 		if (lastConnection) {
 			LOG.info("Contact disconnected");
-			eventBus.broadcast(
+			eventBus.broadcast(new ContactDisconnectedEvent(c));
-					new ConnectionStatusChangedEvent(c, RECENTLY_CONNECTED));
 		}
 	}
 
@@ -145,7 +106,7 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 	public Collection<ContactId> getConnectedContacts(TransportId t) {
 		synchronized (lock) {
 			Multiset<ContactId> m = contactConnections.get(t);
-			if (m == null) return emptyList();
+			if (m == null) return Collections.emptyList();
 			List<ContactId> ids = new ArrayList<>(m.keySet());
 			if (LOG.isLoggable(INFO))
 				LOG.info(ids.size() + " contacts connected: " + t);
@@ -162,11 +123,9 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 	}
 
 	@Override
-	public ConnectionStatus getConnectionStatus(ContactId c) {
+	public boolean isConnected(ContactId c) {
 		synchronized (lock) {
-			Counter counter = contactCounts.get(c);
+			return contactCounts.contains(c);
-			if (counter == null) return DISCONNECTED;
-			return counter.connections > 0 ? CONNECTED : RECENTLY_CONNECTED;
 		}
 	}
 
@@ -188,36 +147,4 @@ class ConnectionRegistryImpl implements ConnectionRegistry {
 		}
 		eventBus.broadcast(new RendezvousConnectionClosedEvent(p, success));
 	}
-
-	@Scheduler
-	private void expireRecentConnections() {
-		long now = clock.currentTimeMillis();
-		List<ContactId> disconnected = new ArrayList<>();
-		synchronized (lock) {
-			Iterator<Entry<ContactId, Counter>> it =
-					contactCounts.entrySet().iterator();
-			while (it.hasNext()) {
-				Entry<ContactId, Counter> e = it.next();
-				if (e.getValue().isExpired(now)) {
-					disconnected.add(e.getKey());
-					it.remove();
-				}
-			}
-		}
-		for (ContactId c : disconnected) {
-			eventBus.broadcast(
-					new ConnectionStatusChangedEvent(c, DISCONNECTED));
-		}
-	}
-
-	private static class Counter {
-
-		private int connections = 0;
-		private long disconnectedTime = 0;
-
-		private boolean isExpired(long now) {
-			return connections == 0 &&
-					now - disconnectedTime > RECENTLY_CONNECTED_MS;
-		}
-	}
 }

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) {
+			int maxLatency, int maxIdleTime) {
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
+		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
-				connectionTimeout);
 	}
 
 	@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 : getLocalIpAddresses()) {
-		for (InetAddress local : getUsableLocalInetAddresses()) {
+			if (isAcceptableAddress(local)) {
-			// If we've used this address before, try to use the same port
+				// If this is the old address, try to use the same port
-			int port = preferredPort;
+				for (InetSocketAddress old : olds) {
-			for (InetSocketAddress old : olds) {
+					if (old.getAddress().equals(local))
-				if (old.getAddress().equals(local)) {
+						locals.add(new InetSocketAddress(local, old.getPort()));
-					port = old.getPort();
-					break;
 				}
+				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 : split) {
-		for (String ipPort : ipPorts.split(SEPARATOR)) {
 			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);
+		return parseSocketAddresses(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;
 	}
 
 	private boolean isAcceptableAddress(InetAddress a) {
@@ -226,33 +145,52 @@ class LanTcpPlugin extends TcpPlugin {
 	}
 
 	@Override
-	protected boolean isConnectable(InterfaceAddress local,
+	protected boolean isConnectable(InetSocketAddress remote) {
-			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 addressesAreOnSameLan(localIp, remoteIp);
-		return areAddressesInSameNetwork(localIp, remoteIp, prefixLength);
 	}
 
 	// Package access for testing
-	static boolean areAddressesInSameNetwork(byte[] localIp, byte[] remoteIp,
+	boolean addressesAreOnSameLan(byte[] localIp, byte[] remoteIp) {
-			int prefixLength) {
+		// 10.0.0.0/8
-		if (localIp.length != remoteIp.length) return false;
+		if (isPrefix10(localIp)) return isPrefix10(remoteIp);
-		// Compare the first prefixLength bits of the addresses
+		// 172.16.0.0/12
-		for (int i = 0; i < prefixLength; i++) {
+		if (isPrefix172(localIp)) return isPrefix172(remoteIp);
-			int byteIndex = i >> 3;
+		// 192.168.0.0/16
-			int bitIndex = i & 7; // 0 to 7
+		if (isPrefix192(localIp)) return isPrefix192(remoteIp);
-			int mask = 128 >> bitIndex; // Select the bit at bitIndex
+		// Unrecognised prefix - may be compatible
-			if ((localIp[byteIndex] & mask) != (remoteIp[byteIndex] & mask)) {
-				return false; // Addresses differ at bit i
-			}
-		}
 		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.bind(new InetSocketAddress(socket.getInetAddress(), 0));
-			s.connect(remote, connectionTimeout);
+			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_LATENCY = 30 * 1000; // 30 seconds
-	private static final int MAX_IDLE_TIME = 30_000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
-	private static final int CONNECTION_TIMEOUT = 3_000; // 3 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
-	private static final int MIN_POLLING_INTERVAL = 60_000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
-	private static final int MAX_POLLING_INTERVAL = 600_000; // 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 maxLatency, maxIdleTime, socketTimeout;
-	protected final int connectionTimeout, 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(InetSocketAddress remote);
-	protected abstract boolean isConnectable(InterfaceAddress local,
-			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 (!isConnectable(remote)) {
-			if (!canConnectToOwnAddress() &&
-					remote.getAddress().equals(ss.getInetAddress())) {
-				continue;
-			}
-			if (!isConnectable(local, 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.bind(new InetSocketAddress(socket.getInetAddress(), 0));
-				s.connect(remote, connectionTimeout);
+				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() {
+	Collection<InetAddress> getLocalIpAddresses() {
-		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() {
 		try {
-			Enumeration<NetworkInterface> ifaces =
+			Enumeration<NetworkInterface> ifaces = getNetworkInterfaces();
-					NetworkInterface.getNetworkInterfaces();
+			if (ifaces == null) return emptyList();
-			return ifaces == null ? emptyList() : list(ifaces);
+			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,
+			PluginCallback callback, int maxLatency, int maxIdleTime) {
-			int connectionTimeout) {
+		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime);
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
-				connectionTimeout);
 		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,
+	protected boolean isConnectable(InetSocketAddress remote) {
-			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_LATENCY = 30 * 1000; // 30 seconds
-	private static final int MAX_IDLE_TIME = 30_000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
-	private static final int CONNECTION_TIMEOUT = 30_000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
-	private static final int MIN_POLLING_INTERVAL = 60_000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
-	private static final int MAX_POLLING_INTERVAL = 600_000; // 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/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) {
+			if (latest == null) return new TransportProperties();
-				remote = new TransportProperties();
+			// Retrieve and parse the latest remote properties
-			} else {
+			BdfList message =
-				// Retrieve and parse the latest remote properties
+					clientHelper.getMessageAsList(txn, latest.messageId);
-				BdfList message =
+			return parseProperties(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;
 		} 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("transportId", t.getString());
-			meta.put(MSG_KEY_VERSION, version);
+			meta.put("version", version);
-			meta.put(MSG_KEY_LOCAL, local);
+			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 =
+			TransportId t = new TransportId(meta.getString("transportId"));
-					new TransportId(meta.getString(MSG_KEY_TRANSPORT_ID));
+			long version = meta.getLong("version");
-			long version = meta.getLong(MSG_KEY_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())
+			if (meta.getString("transportId").equals(t.getString())
-					&& meta.getBoolean(MSG_KEY_LOCAL) == local) {
+					&& meta.getBoolean("local") == local) {
-				return new LatestUpdate(e.getKey(),
+				return new LatestUpdate(e.getKey(), meta.getLong("version"));
-						meta.getLong(MSG_KEY_VERSION));
 			}
 		}
 		return null;

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

@@ -1,7 +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;
@@ -20,15 +19,12 @@ 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;
@@ -39,7 +35,6 @@ 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 {
 
@@ -88,13 +83,8 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testSignInThrowsExceptionIfDbKeyCannotBeLoaded() {
+	public void testSignInReturnsFalseIfDbKeyCannotBeLoaded() {
-		try {
+		assertFalse(accountManager.signIn(password));
-			accountManager.signIn(password);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_CIPHERTEXT, expected.getDecryptionResult());
-		}
 		assertFalse(accountManager.hasDatabaseKey());
 
 		assertFalse(keyFile.exists());
@@ -102,11 +92,11 @@ 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)));
+			will(returnValue(null));
 		}});
 
 		storeDatabaseKey(keyFile, encryptedKeyHex);
@@ -115,12 +105,7 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
 
-		try {
+		assertFalse(accountManager.signIn(password));
-			accountManager.signIn(password);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_PASSWORD, expected.getDecryptionResult());
-		}
 		assertFalse(accountManager.hasDatabaseKey());
 
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
@@ -143,7 +128,7 @@ 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);
@@ -172,7 +157,7 @@ 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);
@@ -254,6 +239,55 @@ 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() {{
@@ -281,36 +315,26 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testChangePasswordThrowsExceptionIfDbKeyCannotBeLoaded() {
+	public void testChangePasswordReturnsFalseIfDbKeyCannotBeLoaded() {
-		try {
+		assertFalse(accountManager.changePassword(password, newPassword));
-			accountManager.changePassword(password, newPassword);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_CIPHERTEXT, expected.getDecryptionResult());
-		}
 
 		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)));
+			will(returnValue(null));
 		}});
 
 		storeDatabaseKey(keyFile, encryptedKeyHex);
 		storeDatabaseKey(keyBackupFile, encryptedKeyHex);
 
-		try {
+		assertFalse(accountManager.changePassword(password, newPassword));
-			accountManager.changePassword(password, newPassword);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_PASSWORD, expected.getDecryptionResult());
-		}
 
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
@@ -333,7 +357,7 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 		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 +366,7 @@ 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 +374,7 @@ 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/crypto/PasswordBasedEncryptionTest.java

@@ -1,35 +1,25 @@
 package org.briarproject.bramble.crypto;
 
-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.system.SystemClock;
-import org.briarproject.bramble.test.BrambleMockTestCase;
+import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestSecureRandomProvider;
-import org.jmock.Expectations;
+import org.briarproject.bramble.test.TestUtils;
 import org.junit.Test;
 
-import static org.briarproject.bramble.api.crypto.DecryptionResult.INVALID_CIPHERTEXT;
+import java.util.Random;
-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.test.TestUtils.getRandomBytes;
-import static org.briarproject.bramble.test.TestUtils.getSecretKey;
 import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
-import static org.junit.Assert.fail;
 
-public class PasswordBasedEncryptionTest extends BrambleMockTestCase {
+public class PasswordBasedEncryptionTest extends BrambleTestCase {
-
-	private final KeyStrengthener keyStrengthener =
-			context.mock(KeyStrengthener.class);
 
 	private final CryptoComponentImpl crypto =
 			new CryptoComponentImpl(new TestSecureRandomProvider(),
 					new ScryptKdf(new SystemClock()));
 
 	@Test
-	public void testEncryptionAndDecryption() throws Exception {
+	public void testEncryptionAndDecryption() {
-		byte[] input = getRandomBytes(1234);
+		byte[] input = TestUtils.getRandomBytes(1234);
 		String password = "password";
 		byte[] ciphertext = crypto.encryptWithPassword(input, password, null);
 		byte[] output = crypto.decryptWithPassword(ciphertext, password, null);
@@ -37,80 +27,14 @@ public class PasswordBasedEncryptionTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testInvalidFormatVersionThrowsException() {
+	public void testInvalidCiphertextReturnsNull() {
-		byte[] input = getRandomBytes(1234);
+		byte[] input = TestUtils.getRandomBytes(1234);
 		String password = "password";
 		byte[] ciphertext = crypto.encryptWithPassword(input, password, null);
-
+		// Modify the ciphertext
-		// Modify the format version
+		int position = new Random().nextInt(ciphertext.length);
-		ciphertext[0] ^= (byte) 0xFF;
+		ciphertext[position] = (byte) (ciphertext[position] ^ 0xFF);
-		try {
+		byte[] output = crypto.decryptWithPassword(ciphertext, password, null);
-			crypto.decryptWithPassword(ciphertext, password, null);
+		assertNull(output);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_CIPHERTEXT, expected.getDecryptionResult());
-		}
-	}
-
-	@Test
-	public void testInvalidPasswordThrowsException() {
-		byte[] input = getRandomBytes(1234);
-		byte[] ciphertext = crypto.encryptWithPassword(input, "password", null);
-
-		// Try to decrypt with the wrong password
-		try {
-			crypto.decryptWithPassword(ciphertext, "wrong", null);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(INVALID_PASSWORD, expected.getDecryptionResult());
-		}
-	}
-
-	@Test
-	public void testMissingKeyStrengthenerThrowsException() {
-		SecretKey strengthened = getSecretKey();
-		context.checking(new Expectations() {{
-			oneOf(keyStrengthener).strengthenKey(with(any(SecretKey.class)));
-			will(returnValue(strengthened));
-		}});
-
-		// Use the key strengthener during encryption
-		byte[] input = getRandomBytes(1234);
-		String password = "password";
-		byte[] ciphertext =
-				crypto.encryptWithPassword(input, password, keyStrengthener);
-
-		// The key strengthener is missing during decryption
-		try {
-			crypto.decryptWithPassword(ciphertext, password, null);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(KEY_STRENGTHENER_ERROR, expected.getDecryptionResult());
-		}
-	}
-
-	@Test
-	public void testKeyStrengthenerFailureThrowsException() {
-		SecretKey strengthened = getSecretKey();
-		context.checking(new Expectations() {{
-			oneOf(keyStrengthener).strengthenKey(with(any(SecretKey.class)));
-			will(returnValue(strengthened));
-			oneOf(keyStrengthener).isInitialised();
-			will(returnValue(false));
-		}});
-
-		// Use the key strengthener during encryption
-		byte[] input = getRandomBytes(1234);
-		String password = "password";
-		byte[] ciphertext =
-				crypto.encryptWithPassword(input, password, keyStrengthener);
-
-		// The key strengthener fails during decryption
-		try {
-			crypto.decryptWithPassword(ciphertext, password, keyStrengthener);
-			fail();
-		} catch (DecryptionException expected) {
-			assertEquals(KEY_STRENGTHENER_ERROR, expected.getDecryptionResult());
-		}
 	}
 }

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

@@ -7,20 +7,18 @@ 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.ConnectionStatusChangedEvent;
+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.system.Clock;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.jmock.Expectations;
 import org.junit.Test;
 
 import java.util.Collection;
-import java.util.concurrent.ScheduledExecutorService;
 
 import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static org.briarproject.bramble.test.TestUtils.getContactId;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.briarproject.bramble.test.TestUtils.getTransportId;
@@ -32,9 +30,6 @@ import static org.junit.Assert.fail;
 public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 
 	private final EventBus eventBus = context.mock(EventBus.class);
-	private final Clock clock = context.mock(Clock.class);
-	private final ScheduledExecutorService scheduler =
-			context.mock(ScheduledExecutorService.class);
 
 	private final ContactId contactId = getContactId();
 	private final ContactId contactId1 = getContactId();
@@ -45,25 +40,17 @@ public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testRegisterAndUnregister() {
-		context.checking(new Expectations() {{
+		ConnectionRegistry c = new ConnectionRegistryImpl(eventBus);
-			oneOf(scheduler).scheduleWithFixedDelay(with(any(Runnable.class)),
-					with(10_000L), with(10_000L), with(MILLISECONDS));
-		}});
-
-		ConnectionRegistry c = new ConnectionRegistryImpl(eventBus, clock,
-				scheduler);
-		context.assertIsSatisfied();
 
 		// The registry should be empty
 		assertEquals(emptyList(), c.getConnectedContacts(transportId));
 		assertEquals(emptyList(), c.getConnectedContacts(transportId1));
 
 		// Check that a registered connection shows up - this should
-		// broadcast a ConnectionOpenedEvent and a ConnectionStatusChangedEvent
+		// broadcast a ConnectionOpenedEvent and a ContactConnectedEvent
 		context.checking(new Expectations() {{
 			oneOf(eventBus).broadcast(with(any(ConnectionOpenedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(
+			oneOf(eventBus).broadcast(with(any(ContactConnectedEvent.class)));
-					ConnectionStatusChangedEvent.class)));
 		}});
 		c.registerConnection(contactId, transportId, true);
 		assertEquals(singletonList(contactId),
@@ -94,13 +81,11 @@ public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 		context.assertIsSatisfied();
 
 		// Unregister the other connection - this should broadcast a
-		// ConnectionClosedEvent and a ConnectionStatusChangedEvent
+		// ConnectionClosedEvent and a ContactDisconnectedEvent
 		context.checking(new Expectations() {{
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(System.currentTimeMillis()));
 			oneOf(eventBus).broadcast(with(any(ConnectionClosedEvent.class)));
 			oneOf(eventBus).broadcast(with(any(
-					ConnectionStatusChangedEvent.class)));
+					ContactDisconnectedEvent.class)));
 		}});
 		c.unregisterConnection(contactId, transportId, true);
 		assertEquals(emptyList(), c.getConnectedContacts(transportId));
@@ -117,12 +102,12 @@ public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 
 		// Register both contacts with one transport, one contact with both -
 		// this should broadcast three ConnectionOpenedEvents and two
-		// ConnectionStatusChangedEvents
+		// ContactConnectedEvents
 		context.checking(new Expectations() {{
 			exactly(3).of(eventBus).broadcast(with(any(
 					ConnectionOpenedEvent.class)));
 			exactly(2).of(eventBus).broadcast(with(any(
-					ConnectionStatusChangedEvent.class)));
+					ContactConnectedEvent.class)));
 		}});
 		c.registerConnection(contactId, transportId, true);
 		c.registerConnection(contactId1, transportId, true);
@@ -137,14 +122,7 @@ public class ConnectionRegistryImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testRegisterAndUnregisterPendingContacts() {
-		context.checking(new Expectations() {{
+		ConnectionRegistry c = new ConnectionRegistryImpl(eventBus);
-			oneOf(scheduler).scheduleWithFixedDelay(with(any(Runnable.class)),
-					with(10_000L), with(10_000L), with(MILLISECONDS));
-		}});
-
-		ConnectionRegistry c = new ConnectionRegistryImpl(eventBus, clock,
-				scheduler);
-		context.assertIsSatisfied();
 
 		context.checking(new Expectations() {{
 			oneOf(eventBus).broadcast(with(any(

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

@@ -7,11 +7,12 @@ import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.settings.Settings;
+import org.briarproject.bramble.plugin.tcp.LanTcpPlugin.LanAddressComparator;
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.junit.Before;
 import org.junit.Test;
 
 import java.io.IOException;
@@ -21,6 +22,7 @@ import java.net.InetSocketAddress;
 import java.net.NetworkInterface;
 import java.net.ServerSocket;
 import java.net.Socket;
+import java.util.Comparator;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -31,89 +33,56 @@ import static java.util.concurrent.Executors.newCachedThreadPool;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.COMMIT_LENGTH;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_LAN;
-import static org.briarproject.bramble.plugin.tcp.LanTcpPlugin.areAddressesInSameNetwork;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
-import static org.junit.Assume.assumeTrue;
 
 public class LanTcpPluginTest extends BrambleTestCase {
 
 	private final Backoff backoff = new TestBackoff();
 	private final ExecutorService ioExecutor = newCachedThreadPool();
 
-	private Callback callback = null;
-	private LanTcpPlugin plugin = null;
-
-	@Before
-	public void setUp() {
-		callback = new Callback();
-		plugin = new LanTcpPlugin(ioExecutor, backoff, callback, 0, 0, 1000) {
-			@Override
-			protected boolean canConnectToOwnAddress() {
-				return true;
-			}
-		};
-	}
-
 	@Test
-	public void testAreAddressesInSameNetwork() {
+	public void testAddressesAreOnSameLan() {
-		// Local and remote in 10.0.0.0/8
+		Callback callback = new Callback();
-		assertTrue(areAddressesInSameNetwork(makeAddress(10, 0, 0, 0),
+		LanTcpPlugin plugin = new LanTcpPlugin(ioExecutor, backoff, callback,
-				makeAddress(10, 255, 255, 255), 8));
+				0, 0);
-		assertFalse(areAddressesInSameNetwork(makeAddress(10, 0, 0, 0),
+		// Local and remote in 10.0.0.0/8 should return true
-				makeAddress(10, 255, 255, 255), 9));
+		assertTrue(plugin.addressesAreOnSameLan(makeAddress(10, 0, 0, 0),
-
+				makeAddress(10, 255, 255, 255)));
-		// Local and remote in 172.16.0.0/12
+		// Local and remote in 172.16.0.0/12 should return true
-		assertTrue(areAddressesInSameNetwork(makeAddress(172, 16, 0, 0),
+		assertTrue(plugin.addressesAreOnSameLan(makeAddress(172, 16, 0, 0),
-				makeAddress(172, 31, 255, 255), 12));
+				makeAddress(172, 31, 255, 255)));
-		assertFalse(areAddressesInSameNetwork(makeAddress(172, 16, 0, 0),
+		// Local and remote in 192.168.0.0/16 should return true
-				makeAddress(172, 31, 255, 255), 13));
+		assertTrue(plugin.addressesAreOnSameLan(makeAddress(192, 168, 0, 0),
-
+				makeAddress(192, 168, 255, 255)));
-		// Local and remote in 192.168.0.0/16
+		// Local and remote in 169.254.0.0/16 (link-local) should return true
-		assertTrue(areAddressesInSameNetwork(makeAddress(192, 168, 0, 0),
+		assertTrue(plugin.addressesAreOnSameLan(makeAddress(169, 254, 0, 0),
-				makeAddress(192, 168, 255, 255), 16));
+				makeAddress(169, 254, 255, 255)));
-		assertFalse(areAddressesInSameNetwork(makeAddress(192, 168, 0, 0),
+		// Local and remote in different recognised prefixes should return false
-				makeAddress(192, 168, 255, 255), 17));
+		assertFalse(plugin.addressesAreOnSameLan(makeAddress(10, 0, 0, 0),
-
+				makeAddress(172, 31, 255, 255)));
-		// Local and remote in 169.254.0.0/16
+		assertFalse(plugin.addressesAreOnSameLan(makeAddress(10, 0, 0, 0),
-		assertTrue(areAddressesInSameNetwork(makeAddress(169, 254, 0, 0),
+				makeAddress(192, 168, 255, 255)));
-				makeAddress(169, 254, 255, 255), 16));
+		assertFalse(plugin.addressesAreOnSameLan(makeAddress(172, 16, 0, 0),
-		assertFalse(areAddressesInSameNetwork(makeAddress(169, 254, 0, 0),
+				makeAddress(10, 255, 255, 255)));
-				makeAddress(169, 254, 255, 255), 17));
+		assertFalse(plugin.addressesAreOnSameLan(makeAddress(172, 16, 0, 0),
-
+				makeAddress(192, 168, 255, 255)));
-		// Local in 10.0.0.0/8, remote in a different network
+		assertFalse(plugin.addressesAreOnSameLan(makeAddress(192, 168, 0, 0),
-		assertFalse(areAddressesInSameNetwork(makeAddress(10, 0, 0, 0),
+				makeAddress(10, 255, 255, 255)));
-				makeAddress(172, 31, 255, 255), 8));
+		assertFalse(plugin.addressesAreOnSameLan(makeAddress(192, 168, 0, 0),
-		assertFalse(areAddressesInSameNetwork(makeAddress(10, 0, 0, 0),
+				makeAddress(172, 31, 255, 255)));
-				makeAddress(192, 168, 255, 255), 8));
+		// Remote prefix unrecognised should return false
-		assertFalse(areAddressesInSameNetwork(makeAddress(10, 0, 0, 0),
+		assertFalse(plugin.addressesAreOnSameLan(makeAddress(10, 0, 0, 0),
-				makeAddress(169, 254, 255, 255), 8));
+				makeAddress(1, 2, 3, 4)));
-
+		assertFalse(plugin.addressesAreOnSameLan(makeAddress(172, 16, 0, 0),
-		// Local in 172.16.0.0/12, remote in a different network
+				makeAddress(1, 2, 3, 4)));
-		assertFalse(areAddressesInSameNetwork(makeAddress(172, 16, 0, 0),
+		assertFalse(plugin.addressesAreOnSameLan(makeAddress(192, 168, 0, 0),
-				makeAddress(10, 255, 255, 255), 12));
+				makeAddress(1, 2, 3, 4)));
-		assertFalse(areAddressesInSameNetwork(makeAddress(172, 16, 0, 0),
+		// Both prefixes unrecognised should return true (could be link-local)
-				makeAddress(192, 168, 255, 255), 12));
+		assertTrue(plugin.addressesAreOnSameLan(makeAddress(1, 2, 3, 4),
-		assertFalse(areAddressesInSameNetwork(makeAddress(172, 16, 0, 0),
+				makeAddress(5, 6, 7, 8)));
-				makeAddress(169, 254, 255, 255), 12));
-
-		// Local in 192.168.0.0/16, remote in a different network
-		assertFalse(areAddressesInSameNetwork(makeAddress(192, 168, 0, 0),
-				makeAddress(10, 255, 255, 255), 16));
-		assertFalse(areAddressesInSameNetwork(makeAddress(192, 168, 0, 0),
-				makeAddress(172, 31, 255, 255), 16));
-		assertFalse(areAddressesInSameNetwork(makeAddress(192, 168, 0, 0),
-				makeAddress(169, 254, 255, 255), 16));
-
-		// Local in 169.254.0.0/16, remote in a different network
-		assertFalse(areAddressesInSameNetwork(makeAddress(169, 254, 0, 0),
-				makeAddress(10, 255, 255, 255), 16));
-		assertFalse(areAddressesInSameNetwork(makeAddress(169, 254, 0, 0),
-				makeAddress(172, 31, 255, 255), 16));
-		assertFalse(areAddressesInSameNetwork(makeAddress(169, 254, 0, 0),
-				makeAddress(192, 168, 255, 255), 16));
 	}
 
 	private byte[] makeAddress(int... parts) {
@@ -124,7 +93,13 @@ public class LanTcpPluginTest extends BrambleTestCase {
 
 	@Test
 	public void testIncomingConnection() throws Exception {
-		assumeTrue(systemHasLocalIpv4Address());
+		if (!systemHasLocalIpv4Address()) {
+			System.err.println("WARNING: Skipping test, no local IPv4 address");
+			return;
+		}
+		Callback callback = new Callback();
+		DuplexPlugin plugin = new LanTcpPlugin(ioExecutor, backoff, callback,
+				0, 0);
 		plugin.start();
 		// The plugin should have bound a socket and stored the port number
 		assertTrue(callback.propertiesLatch.await(5, SECONDS));
@@ -153,7 +128,13 @@ public class LanTcpPluginTest extends BrambleTestCase {
 
 	@Test
 	public void testOutgoingConnection() throws Exception {
-		assumeTrue(systemHasLocalIpv4Address());
+		if (!systemHasLocalIpv4Address()) {
+			System.err.println("WARNING: Skipping test, no local IPv4 address");
+			return;
+		}
+		Callback callback = new Callback();
+		DuplexPlugin plugin = new LanTcpPlugin(ioExecutor, backoff, callback,
+				0, 0);
 		plugin.start();
 		// The plugin should have bound a socket and stored the port number
 		assertTrue(callback.propertiesLatch.await(5, SECONDS));
@@ -196,7 +177,13 @@ public class LanTcpPluginTest extends BrambleTestCase {
 
 	@Test
 	public void testIncomingKeyAgreementConnection() throws Exception {
-		assumeTrue(systemHasLocalIpv4Address());
+		if (!systemHasLocalIpv4Address()) {
+			System.err.println("WARNING: Skipping test, no local IPv4 address");
+			return;
+		}
+		Callback callback = new Callback();
+		DuplexPlugin plugin = new LanTcpPlugin(ioExecutor, backoff, callback,
+				0, 0);
 		plugin.start();
 		assertTrue(callback.propertiesLatch.await(5, SECONDS));
 		KeyAgreementListener kal =
@@ -238,7 +225,13 @@ public class LanTcpPluginTest extends BrambleTestCase {
 
 	@Test
 	public void testOutgoingKeyAgreementConnection() throws Exception {
-		assumeTrue(systemHasLocalIpv4Address());
+		if (!systemHasLocalIpv4Address()) {
+			System.err.println("WARNING: Skipping test, no local IPv4 address");
+			return;
+		}
+		Callback callback = new Callback();
+		DuplexPlugin plugin = new LanTcpPlugin(ioExecutor, backoff, callback,
+				0, 0);
 		plugin.start();
 		// The plugin should have bound a socket and stored the port number
 		assertTrue(callback.propertiesLatch.await(5, SECONDS));
@@ -283,12 +276,62 @@ public class LanTcpPluginTest extends BrambleTestCase {
 		plugin.stop();
 	}
 
+	@Test
+	public void testComparatorPrefersNonZeroPorts() {
+		Comparator<InetSocketAddress> comparator = new LanAddressComparator();
+		InetSocketAddress nonZero = new InetSocketAddress("1.2.3.4", 1234);
+		InetSocketAddress zero = new InetSocketAddress("1.2.3.4", 0);
+
+		assertEquals(0, comparator.compare(nonZero, nonZero));
+		assertTrue(comparator.compare(nonZero, zero) < 0);
+
+		assertTrue(comparator.compare(zero, nonZero) > 0);
+		assertEquals(0, comparator.compare(zero, zero));
+	}
+
+	@Test
+	public void testComparatorPrefersLongerPrefixes() {
+		Comparator<InetSocketAddress> comparator = new LanAddressComparator();
+		InetSocketAddress prefix192 = new InetSocketAddress("192.168.0.1", 0);
+		InetSocketAddress prefix172 = new InetSocketAddress("172.16.0.1", 0);
+		InetSocketAddress prefix10 = new InetSocketAddress("10.0.0.1", 0);
+
+		assertEquals(0, comparator.compare(prefix192, prefix192));
+		assertTrue(comparator.compare(prefix192, prefix172) < 0);
+		assertTrue(comparator.compare(prefix192, prefix10) < 0);
+
+		assertTrue(comparator.compare(prefix172, prefix192) > 0);
+		assertEquals(0, comparator.compare(prefix172, prefix172));
+		assertTrue(comparator.compare(prefix172, prefix10) < 0);
+
+		assertTrue(comparator.compare(prefix10, prefix192) > 0);
+		assertTrue(comparator.compare(prefix10, prefix172) > 0);
+		assertEquals(0, comparator.compare(prefix10, prefix10));
+	}
+
+	@Test
+	public void testComparatorPrefersSiteLocalToLinkLocal() {
+		Comparator<InetSocketAddress> comparator = new LanAddressComparator();
+		InetSocketAddress prefix192 = new InetSocketAddress("192.168.0.1", 0);
+		InetSocketAddress prefix172 = new InetSocketAddress("172.16.0.1", 0);
+		InetSocketAddress prefix10 = new InetSocketAddress("10.0.0.1", 0);
+		InetSocketAddress linkLocal = new InetSocketAddress("169.254.0.1", 0);
+
+		assertTrue(comparator.compare(prefix192, linkLocal) < 0);
+		assertTrue(comparator.compare(prefix172, linkLocal) < 0);
+		assertTrue(comparator.compare(prefix10, linkLocal) < 0);
+
+		assertTrue(comparator.compare(linkLocal, prefix192) > 0);
+		assertTrue(comparator.compare(linkLocal, prefix172) > 0);
+		assertTrue(comparator.compare(linkLocal, prefix10) > 0);
+		assertEquals(0, comparator.compare(linkLocal, linkLocal));
+	}
+
 	private boolean systemHasLocalIpv4Address() throws Exception {
 		for (NetworkInterface i : list(getNetworkInterfaces())) {
 			for (InetAddress a : list(i.getInetAddresses())) {
-				if (a instanceof Inet4Address) {
+				if (a instanceof Inet4Address)
 					return a.isLinkLocalAddress() || a.isSiteLocalAddress();
-				}
 			}
 		}
 		return false;
@@ -297,9 +340,7 @@ public class LanTcpPluginTest extends BrambleTestCase {
 	@NotNullByDefault
 	private static class Callback implements PluginCallback {
 
-		// Properties will be stored twice: the preferred port at startup,
+		private final CountDownLatch propertiesLatch = new CountDownLatch(1);
-		// and the IP:port when the server socket is bound
-		private final CountDownLatch propertiesLatch = new CountDownLatch(2);
 		private final CountDownLatch connectionsLatch = new CountDownLatch(1);
 		private final TransportProperties local = new TransportProperties();
 

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

@@ -24,18 +24,14 @@ import org.briarproject.bramble.test.DbExpectations;
 import org.jmock.Expectations;
 import org.junit.Test;
 
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 
 import static java.util.Arrays.asList;
-import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
-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;
 import static org.briarproject.bramble.api.properties.TransportPropertyManager.CLIENT_ID;
 import static org.briarproject.bramble.api.properties.TransportPropertyManager.MAJOR_VERSION;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
@@ -190,25 +186,25 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		Message message = getMessage(contactGroupId);
 		Metadata meta = new Metadata();
 		BdfDictionary metaDictionary = BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 2),
+				new BdfEntry("version", 2),
-				new BdfEntry(MSG_KEY_LOCAL, false)
+				new BdfEntry("local", false)
 		);
 		Map<MessageId, BdfDictionary> messageMetadata =
 				new LinkedHashMap<>();
 		// A remote update for another transport should be ignored
 		MessageId barUpdateId = new MessageId(getRandomId());
 		messageMetadata.put(barUpdateId, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "bar"),
+				new BdfEntry("transportId", "bar"),
-				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry("version", 1),
-				new BdfEntry(MSG_KEY_LOCAL, false)
+				new BdfEntry("local", false)
 		));
 		// A local update for the same transport should be ignored
 		MessageId localUpdateId = new MessageId(getRandomId());
 		messageMetadata.put(localUpdateId, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry("version", 1),
-				new BdfEntry(MSG_KEY_LOCAL, true)
+				new BdfEntry("local", true)
 		));
 
 		context.checking(new Expectations() {{
@@ -232,18 +228,18 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		Metadata meta = new Metadata();
 		// Version 4 is being delivered
 		BdfDictionary metaDictionary = BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 4),
+				new BdfEntry("version", 4),
-				new BdfEntry(MSG_KEY_LOCAL, false)
+				new BdfEntry("local", false)
 		);
 		Map<MessageId, BdfDictionary> messageMetadata =
 				new LinkedHashMap<>();
 		// An older remote update for the same transport should be deleted
 		MessageId fooVersion3 = new MessageId(getRandomId());
 		messageMetadata.put(fooVersion3, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 3),
+				new BdfEntry("version", 3),
-				new BdfEntry(MSG_KEY_LOCAL, false)
+				new BdfEntry("local", false)
 		));
 
 		context.checking(new Expectations() {{
@@ -269,18 +265,18 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		Metadata meta = new Metadata();
 		// Version 3 is being delivered
 		BdfDictionary metaDictionary = BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 3),
+				new BdfEntry("version", 3),
-				new BdfEntry(MSG_KEY_LOCAL, false)
+				new BdfEntry("local", false)
 		);
 		Map<MessageId, BdfDictionary> messageMetadata =
 				new LinkedHashMap<>();
 		// A newer remote update for the same transport should not be deleted
 		MessageId fooVersion4 = new MessageId(getRandomId());
 		messageMetadata.put(fooVersion4, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 4),
+				new BdfEntry("version", 4),
-				new BdfEntry(MSG_KEY_LOCAL, false)
+				new BdfEntry("local", false)
 		));
 
 		context.checking(new Expectations() {{
@@ -346,9 +342,9 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		// A local update for another transport should be ignored
 		MessageId barUpdateId = new MessageId(getRandomId());
 		messageMetadata.put(barUpdateId, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "bar"),
+				new BdfEntry("transportId", "bar"),
-				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry("version", 1),
-				new BdfEntry(MSG_KEY_LOCAL, true)
+				new BdfEntry("local", true)
 		));
 
 		context.checking(new DbExpectations() {{
@@ -370,16 +366,16 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		// A local update for another transport should be ignored
 		MessageId barUpdateId = new MessageId(getRandomId());
 		messageMetadata.put(barUpdateId, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "bar"),
+				new BdfEntry("transportId", "bar"),
-				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry("version", 1),
-				new BdfEntry(MSG_KEY_LOCAL, true)
+				new BdfEntry("local", true)
 		));
 		// A local update for the right transport should be returned
 		MessageId fooUpdateId = new MessageId(getRandomId());
 		messageMetadata.put(fooUpdateId, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry("version", 1),
-				new BdfEntry(MSG_KEY_LOCAL, true)
+				new BdfEntry("local", true)
 		));
 		BdfList fooUpdate = BdfList.of("foo", 1, fooPropertiesDict);
 
@@ -409,28 +405,28 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		List<Contact> contacts = asList(contact1, contact2);
 		Group contactGroup1 = getGroup(CLIENT_ID, MAJOR_VERSION);
 		Group contactGroup2 = getGroup(CLIENT_ID, MAJOR_VERSION);
-		Map<MessageId, BdfDictionary> messageMetadata =
+		Map<MessageId, BdfDictionary> messageMetadata2 =
 				new LinkedHashMap<>();
 		// A remote update for another transport should be ignored
 		MessageId barUpdateId = new MessageId(getRandomId());
-		messageMetadata.put(barUpdateId, BdfDictionary.of(
+		messageMetadata2.put(barUpdateId, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "bar"),
+				new BdfEntry("transportId", "bar"),
-				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry("version", 1),
-				new BdfEntry(MSG_KEY_LOCAL, false)
+				new BdfEntry("local", false)
 		));
 		// A local update for the right transport should be ignored
 		MessageId localUpdateId = new MessageId(getRandomId());
-		messageMetadata.put(localUpdateId, BdfDictionary.of(
+		messageMetadata2.put(localUpdateId, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry("version", 1),
-				new BdfEntry(MSG_KEY_LOCAL, true)
+				new BdfEntry("local", true)
 		));
 		// A remote update for the right transport should be returned
 		MessageId fooUpdateId = new MessageId(getRandomId());
-		messageMetadata.put(fooUpdateId, BdfDictionary.of(
+		messageMetadata2.put(fooUpdateId, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry("version", 1),
-				new BdfEntry(MSG_KEY_LOCAL, false)
+				new BdfEntry("local", false)
 		));
 		BdfList fooUpdate = BdfList.of("foo", 1, fooPropertiesDict);
 
@@ -444,25 +440,19 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(contactGroup1));
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup1.getId());
-			will(returnValue(emptyMap()));
+			will(returnValue(Collections.emptyMap()));
-			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
-					contactGroup1.getId());
-			will(returnValue(new BdfDictionary()));
 			// Second contact: returns an update
 			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
 					MAJOR_VERSION, contact2);
 			will(returnValue(contactGroup2));
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup2.getId());
-			will(returnValue(messageMetadata));
+			will(returnValue(messageMetadata2));
 			oneOf(clientHelper).getMessageAsList(txn, fooUpdateId);
 			will(returnValue(fooUpdate));
 			oneOf(clientHelper).parseAndValidateTransportProperties(
 					fooPropertiesDict);
 			will(returnValue(fooProperties));
-			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
-					contactGroup2.getId());
-			will(returnValue(new BdfDictionary()));
 		}});
 
 		TransportPropertyManagerImpl t = createInstance();
@@ -473,62 +463,6 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		assertEquals(fooProperties, properties.get(contact2.getId()));
 	}
 
-	@Test
-	public void testReceivePropertiesOverrideDiscoveredProperties()
-			throws Exception {
-		Transaction txn = new Transaction(null, true);
-		Contact contact = getContact();
-		List<Contact> contacts = singletonList(contact);
-		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
-		MessageId updateId = new MessageId(getRandomId());
-		Map<MessageId, BdfDictionary> messageMetadata = singletonMap(updateId,
-				BdfDictionary.of(
-						new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
-						new BdfEntry(MSG_KEY_VERSION, 1),
-						new BdfEntry(MSG_KEY_LOCAL, false)
-				));
-		BdfList update = BdfList.of("foo", 1, fooPropertiesDict);
-		TransportProperties discovered = new TransportProperties();
-		discovered.put("fooKey1", "overridden");
-		discovered.put("fooKey3", "fooValue3");
-		BdfDictionary discoveredDict = new BdfDictionary(discovered);
-		BdfDictionary groupMeta = BdfDictionary.of(
-				new BdfEntry(GROUP_KEY_DISCOVERED, discoveredDict)
-		);
-		TransportProperties merged = new TransportProperties();
-		merged.putAll(fooProperties);
-		merged.put("fooKey3", "fooValue3");
-
-		context.checking(new DbExpectations() {{
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getContacts(txn);
-			will(returnValue(contacts));
-			// One update
-			oneOf(contactGroupFactory).createContactGroup(CLIENT_ID,
-					MAJOR_VERSION, contact);
-			will(returnValue(contactGroup));
-			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
-					contactGroup.getId());
-			will(returnValue(messageMetadata));
-			oneOf(clientHelper).getMessageAsList(txn, updateId);
-			will(returnValue(update));
-			oneOf(clientHelper).parseAndValidateTransportProperties(
-					fooPropertiesDict);
-			will(returnValue(fooProperties));
-			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
-					contactGroup.getId());
-			will(returnValue(groupMeta));
-			oneOf(clientHelper).parseAndValidateTransportProperties(
-					discoveredDict);
-			will(returnValue(discovered));
-		}});
-
-		TransportPropertyManagerImpl t = createInstance();
-		Map<ContactId, TransportProperties> properties =
-				t.getRemoteProperties(new TransportId("foo"));
-		assertEquals(merged, properties.get(contact.getId()));
-	}
-
 	@Test
 	public void testMergingUnchangedPropertiesDoesNotCreateUpdate()
 			throws Exception {
@@ -536,9 +470,9 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		MessageId updateId = new MessageId(getRandomId());
 		Map<MessageId, BdfDictionary> messageMetadata = singletonMap(updateId,
 				BdfDictionary.of(
-						new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+						new BdfEntry("transportId", "foo"),
-						new BdfEntry(MSG_KEY_VERSION, 1),
+						new BdfEntry("version", 1),
-						new BdfEntry(MSG_KEY_LOCAL, true)
+						new BdfEntry("local", true)
 				));
 		BdfList update = BdfList.of("foo", 1, fooPropertiesDict);
 
@@ -571,7 +505,7 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			// There are no existing properties to merge with
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					localGroup.getId());
-			will(returnValue(emptyMap()));
+			will(returnValue(Collections.emptyMap()));
 			// Store the new properties in the local group, version 1
 			expectStoreMessage(txn, localGroup.getId(), "foo",
 					fooPropertiesDict, 1, true, false);
@@ -583,7 +517,7 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(contactGroup));
 			oneOf(clientHelper).getMessageMetadataAsDictionary(txn,
 					contactGroup.getId());
-			will(returnValue(emptyMap()));
+			will(returnValue(Collections.emptyMap()));
 			expectStoreMessage(txn, contactGroup.getId(), "foo",
 					fooPropertiesDict, 1, true, true);
 		}});
@@ -598,9 +532,9 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		Contact contact = getContact();
 		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
 		BdfDictionary oldMetadata = BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 1),
+				new BdfEntry("version", 1),
-				new BdfEntry(MSG_KEY_LOCAL, true)
+				new BdfEntry("local", true)
 		);
 		MessageId localGroupUpdateId = new MessageId(getRandomId());
 		Map<MessageId, BdfDictionary> localGroupMessageMetadata =
@@ -655,14 +589,14 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		// The latest update for transport "foo" should be returned
 		MessageId fooVersion999 = new MessageId(getRandomId());
 		messageMetadata.put(fooVersion999, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "foo"),
+				new BdfEntry("transportId", "foo"),
-				new BdfEntry(MSG_KEY_VERSION, 999)
+				new BdfEntry("version", 999)
 		));
 		// The latest update for transport "bar" should be returned
 		MessageId barVersion3 = new MessageId(getRandomId());
 		messageMetadata.put(barVersion3, BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, "bar"),
+				new BdfEntry("transportId", "bar"),
-				new BdfEntry(MSG_KEY_VERSION, 3)
+				new BdfEntry("version", 3)
 		));
 		BdfList fooUpdate = BdfList.of("foo", 999, fooPropertiesDict);
 		BdfList barUpdate = BdfList.of("bar", 3, barPropertiesDict);
@@ -693,9 +627,9 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		Message message = getMessage(g);
 		long timestamp = message.getTimestamp();
 		BdfDictionary meta = BdfDictionary.of(
-				new BdfEntry(MSG_KEY_TRANSPORT_ID, transportId),
+				new BdfEntry("transportId", transportId),
-				new BdfEntry(MSG_KEY_VERSION, version),
+				new BdfEntry("version", version),
-				new BdfEntry(MSG_KEY_LOCAL, local)
+				new BdfEntry("local", local)
 		);
 
 		context.checking(new Expectations() {{

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

@@ -4,7 +4,6 @@ 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.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.properties.TransportProperties;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -38,11 +37,6 @@ public class TestDuplexTransportConnection
 		return writer;
 	}
 
-	@Override
-	public TransportProperties getRemoteProperties() {
-		return new TransportProperties();
-	}
-
 	/**
 	 * Creates and returns a pair of TestDuplexTransportConnections that are
 	 * connected to each other.

bramble-java/build.gradle

@@ -16,7 +16,7 @@ dependencies {
 	implementation fileTree(dir: 'libs', include: '*.jar')
 	implementation 'net.java.dev.jna:jna:4.5.2'
 	implementation 'net.java.dev.jna:jna-platform:4.5.2'
-	tor 'org.briarproject:tor:0.3.5.10@zip'
+	tor 'org.briarproject:tor:0.3.5.9@zip'
 	tor 'org.briarproject:obfs4proxy:0.0.7@zip'
 
 	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'

bramble-java/witness.gradle

@@ -24,7 +24,7 @@ dependencyVerification {
         'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
         'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
         'org.briarproject:obfs4proxy:0.0.7:obfs4proxy-0.0.7.zip:5b2f693262ce43a7e130f7cc7d5d1617925330640a2eb6d71085e95df8ee0642',
-        'org.briarproject:tor:0.3.5.10:tor-0.3.5.10.zip:7b387d3523ae8af289c23be59dc4c64ec5d3721385d7825a09705095e3318d5c',
+        'org.briarproject:tor:0.3.5.9:tor-0.3.5.9.zip:6c3994b129db019cc23caaf50d6b4383903c40d05fbc47fc94211170a3e5d38c',
         '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.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',

briar-android/build.gradle

@@ -22,8 +22,8 @@ android {
 	defaultConfig {
 		minSdkVersion 16
 		targetSdkVersion 28
-		versionCode 10207
+		versionCode 10205
-		versionName "1.2.7"
+		versionName "1.2.5"
 		applicationId "org.briarproject.briar.android"
 		buildConfigField "String", "GitHash",
 				"\"${getStdout(['git', 'rev-parse', '--short=7', 'HEAD'], 'No commit hash')}\""
@@ -98,7 +98,7 @@ dependencies {
 	implementation 'androidx.lifecycle:lifecycle-extensions:2.1.0'
 	implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
 	implementation 'com.google.android.material:material:1.1.0-beta01'
-	implementation 'androidx.recyclerview:recyclerview-selection:1.1.0-rc01'
+	implementation 'androidx.recyclerview:recyclerview-selection:1.0.0'
 
 	implementation 'ch.acra:acra:4.11'
 	implementation 'info.guardianproject.panic:panic:1.0'

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/attachment/AttachmentRetrieverIntegrationTest.java

@@ -13,8 +13,9 @@ import java.util.Random;
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 
 import static androidx.test.InstrumentationRegistry.getContext;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.AVAILABLE;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.ERROR;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 @RunWith(AndroidJUnit4.class)
@@ -27,7 +28,7 @@ public class AttachmentRetrieverIntegrationTest {
 
 	private final ImageHelper imageHelper = new ImageHelperImpl();
 	private final AttachmentRetriever retriever =
-			new AttachmentRetrieverImpl(null, dimensions, imageHelper,
+			new AttachmentRetrieverImpl(null, null, dimensions, imageHelper,
 					new ImageSizeCalculator(imageHelper));
 
 	@Test
@@ -35,7 +36,7 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("kitten_small.jpg");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(msgId, item.getMessageId());
 		assertEquals(160, item.getWidth());
 		assertEquals(240, item.getHeight());
@@ -43,7 +44,7 @@ public class AttachmentRetrieverIntegrationTest {
 		assertEquals(240, item.getThumbnailHeight());
 		assertEquals("image/jpeg", item.getMimeType());
 		assertJpgOrJpeg(item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -51,7 +52,7 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("kitten_original.jpg");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(msgId, item.getMessageId());
 		assertEquals(1728, item.getWidth());
 		assertEquals(2592, item.getHeight());
@@ -59,7 +60,7 @@ public class AttachmentRetrieverIntegrationTest {
 		assertEquals(dimensions.maxHeight, item.getThumbnailHeight());
 		assertEquals("image/jpeg", item.getMimeType());
 		assertJpgOrJpeg(item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -67,7 +68,7 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/png");
 		InputStream is = getAssetInputStream("kitten.png");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(msgId, item.getMessageId());
 		assertEquals(737, item.getWidth());
 		assertEquals(510, item.getHeight());
@@ -75,7 +76,7 @@ public class AttachmentRetrieverIntegrationTest {
 		assertEquals(138, item.getThumbnailHeight());
 		assertEquals("image/png", item.getMimeType());
 		assertEquals("png", item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -83,14 +84,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
 		InputStream is = getAssetInputStream("uber.gif");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(1, item.getWidth());
 		assertEquals(1, item.getHeight());
 		assertEquals(dimensions.minHeight, item.getThumbnailWidth());
 		assertEquals(dimensions.minHeight, item.getThumbnailHeight());
 		assertEquals("image/gif", item.getMimeType());
 		assertEquals("gif", item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -98,14 +99,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("lottapixel.jpg");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(64250, item.getWidth());
 		assertEquals(64250, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
 		assertEquals(dimensions.maxWidth, item.getThumbnailHeight());
 		assertEquals("image/jpeg", item.getMimeType());
 		assertJpgOrJpeg(item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -113,14 +114,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/png");
 		InputStream is = getAssetInputStream("image_io_crash.png");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(1184, item.getWidth());
 		assertEquals(448, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
 		assertEquals(dimensions.minHeight, item.getThumbnailHeight());
 		assertEquals("image/png", item.getMimeType());
 		assertEquals("png", item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -128,14 +129,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
 		InputStream is = getAssetInputStream("gimp_crash.gif");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(1, item.getWidth());
 		assertEquals(1, item.getHeight());
 		assertEquals(dimensions.minHeight, item.getThumbnailWidth());
 		assertEquals(dimensions.minHeight, item.getThumbnailHeight());
 		assertEquals("image/gif", item.getMimeType());
 		assertEquals("gif", item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -143,14 +144,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
 		InputStream is = getAssetInputStream("opti_png_afl.gif");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(32, item.getWidth());
 		assertEquals(32, item.getHeight());
 		assertEquals(dimensions.minHeight, item.getThumbnailWidth());
 		assertEquals(dimensions.minHeight, item.getThumbnailHeight());
 		assertEquals("image/gif", item.getMimeType());
 		assertEquals("gif", item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -158,8 +159,8 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("libraw_error.jpg");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
-		assertTrue(item.hasError());
+		assertEquals(ERROR, item.getState());
 	}
 
 	@Test
@@ -167,14 +168,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
 		InputStream is = getAssetInputStream("animated.gif");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(65535, item.getWidth());
 		assertEquals(65535, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
 		assertEquals(dimensions.maxWidth, item.getThumbnailHeight());
 		assertEquals("image/gif", item.getMimeType());
 		assertEquals("gif", item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -182,14 +183,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
 		InputStream is = getAssetInputStream("animated2.gif");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(10000, item.getWidth());
 		assertEquals(10000, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
 		assertEquals(dimensions.maxWidth, item.getThumbnailHeight());
 		assertEquals("image/gif", item.getMimeType());
 		assertEquals("gif", item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -197,14 +198,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/gif");
 		InputStream is = getAssetInputStream("error_large.gif");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(16384, item.getWidth());
 		assertEquals(16384, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
 		assertEquals(dimensions.maxWidth, item.getThumbnailHeight());
 		assertEquals("image/gif", item.getMimeType());
 		assertEquals("gif", item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -212,14 +213,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("error_high.jpg");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(1, item.getWidth());
 		assertEquals(10000, item.getHeight());
 		assertEquals(dimensions.minWidth, item.getThumbnailWidth());
 		assertEquals(dimensions.maxHeight, item.getThumbnailHeight());
 		assertEquals("image/jpeg", item.getMimeType());
 		assertJpgOrJpeg(item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	@Test
@@ -227,14 +228,14 @@ public class AttachmentRetrieverIntegrationTest {
 		AttachmentHeader h = new AttachmentHeader(msgId, "image/jpeg");
 		InputStream is = getAssetInputStream("error_wide.jpg");
 		Attachment a = new Attachment(h, is);
-		AttachmentItem item = retriever.getAttachmentItem(a, true);
+		AttachmentItem item = retriever.createAttachmentItem(a, true);
 		assertEquals(1920, item.getWidth());
 		assertEquals(1, item.getHeight());
 		assertEquals(dimensions.maxWidth, item.getThumbnailWidth());
 		assertEquals(dimensions.minHeight, item.getThumbnailHeight());
 		assertEquals("image/jpeg", item.getMimeType());
 		assertJpgOrJpeg(item.getExtension());
-		assertFalse(item.hasError());
+		assertEquals(AVAILABLE, item.getState());
 	}
 
 	private InputStream getAssetInputStream(String name) throws Exception {

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

@@ -28,9 +28,7 @@ import static android.security.keystore.KeyProperties.PURPOSE_SIGN;
 import static java.util.Arrays.asList;
 import static java.util.Collections.singletonList;
 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.util.LogUtils.logException;
 
 @RequiresApi(23)
 @NotNullByDefault
@@ -81,10 +79,7 @@ class AndroidKeyStrengthener implements KeyStrengthener {
 				return true;
 			}
 			return false;
-		} catch (GeneralSecurityException e) {
+		} catch (GeneralSecurityException | IOException e) {
-			logException(LOG, WARNING, e);
-			return false;
-		} catch (IOException e) {
 			throw new RuntimeException(e);
 		}
 	}

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

@@ -36,7 +36,6 @@ import org.briarproject.bramble.util.AndroidUtils;
 import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.android.account.LockManagerImpl;
 import org.briarproject.briar.android.keyagreement.ContactExchangeModule;
-import org.briarproject.briar.android.login.LoginModule;
 import org.briarproject.briar.android.viewmodel.ViewModelModule;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.DozeWatchdog;
@@ -65,11 +64,7 @@ import static org.briarproject.bramble.api.reporting.ReportingConstants.DEV_ONIO
 import static org.briarproject.bramble.api.reporting.ReportingConstants.DEV_PUBLIC_KEY_HEX;
 import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 
-@Module(includes = {
+@Module(includes = {ContactExchangeModule.class, ViewModelModule.class})
-		ContactExchangeModule.class,
-		LoginModule.class,
-		ViewModelModule.class
-})
 public class AppModule {
 
 	static class EagerSingletons {

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

@@ -8,6 +8,8 @@ import org.briarproject.briar.android.controller.BriarController;
 import org.briarproject.briar.android.controller.BriarControllerImpl;
 import org.briarproject.briar.android.controller.DbController;
 import org.briarproject.briar.android.controller.DbControllerImpl;
+import org.briarproject.briar.android.login.ChangePasswordController;
+import org.briarproject.briar.android.login.ChangePasswordControllerImpl;
 import org.briarproject.briar.android.navdrawer.NavDrawerController;
 import org.briarproject.briar.android.navdrawer.NavDrawerControllerImpl;
 
@@ -44,6 +46,13 @@ public class ActivityModule {
 		return setupController;
 	}
 
+	@ActivityScope
+	@Provides
+	ChangePasswordController providePasswordController(
+			ChangePasswordControllerImpl passwordController) {
+		return passwordController;
+	}
+
 	@ActivityScope
 	@Provides
 	protected BriarController provideBriarController(
@@ -71,4 +80,5 @@ public class ActivityModule {
 	BriarServiceConnection provideBriarServiceConnection() {
 		return new BriarServiceConnection();
 	}
+
 }

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

@@ -92,9 +92,6 @@ public abstract class BaseActivity extends AppCompatActivity
 				.build();
 		injectActivity(activityComponent);
 		super.onCreate(state);
-		if (LOG.isLoggable(INFO)) {
-			LOG.info("Creating " + getClass().getSimpleName());
-		}
 
 		// WARNING: When removing this or making it possible to turn it off,
 		//          we need a solution for the app lock feature.
@@ -130,9 +127,8 @@ public abstract class BaseActivity extends AppCompatActivity
 	@Override
 	protected void onStart() {
 		super.onStart();
-		if (LOG.isLoggable(INFO)) {
+		if (LOG.isLoggable(INFO))
-			LOG.info("Starting " + getClass().getSimpleName());
+			LOG.info("Starting " + this.getClass().getSimpleName());
-		}
 		for (ActivityLifecycleController alc : lifecycleControllers) {
 			alc.onActivityStart();
 		}
@@ -148,28 +144,11 @@ public abstract class BaseActivity extends AppCompatActivity
 		return (ScreenFilterDialogFragment) f;
 	}
 
-	@Override
-	protected void onResume() {
-		super.onResume();
-		if (LOG.isLoggable(INFO)) {
-			LOG.info("Resuming " + getClass().getSimpleName());
-		}
-	}
-
-	@Override
-	protected void onPause() {
-		super.onPause();
-		if (LOG.isLoggable(INFO)) {
-			LOG.info("Pausing " + getClass().getSimpleName());
-		}
-	}
-
 	@Override
 	protected void onStop() {
 		super.onStop();
-		if (LOG.isLoggable(INFO)) {
+		if (LOG.isLoggable(INFO))
-			LOG.info("Stopping " + getClass().getSimpleName());
+			LOG.info("Stopping " + this.getClass().getSimpleName());
-		}
 		for (ActivityLifecycleController alc : lifecycleControllers) {
 			alc.onActivityStop();
 		}
@@ -224,9 +203,6 @@ public abstract class BaseActivity extends AppCompatActivity
 	@Override
 	protected void onDestroy() {
 		super.onDestroy();
-		if (LOG.isLoggable(INFO)) {
-			LOG.info("Destroying " + getClass().getSimpleName());
-		}
 		destroyed = true;
 		for (ActivityLifecycleController alc : lifecycleControllers) {
 			alc.onActivityDestroy();

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

@@ -95,14 +95,12 @@ public abstract class BriarActivity extends BaseActivity {
 			// Also check that the activity isn't finishing already.
 			// This is possible if we finished in onActivityResult().
 			// Launching another StartupActivity would cause a loop.
-			LOG.info("Not signed in, launching StartupActivity");
 			Intent i = new Intent(this, StartupActivity.class);
 			startActivityForResult(i, REQUEST_PASSWORD);
 		} else if (lockManager.isLocked() && !isFinishing()) {
 			// Also check that the activity isn't finishing already.
 			// This is possible if we finished in onActivityResult().
 			// Launching another UnlockActivity would cause a loop.
-			LOG.info("Locked, launching UnlockActivity");
 			Intent i = new Intent(this, UnlockActivity.class);
 			startActivityForResult(i, REQUEST_UNLOCK);
 		} else if (SDK_INT >= 23) {

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentCreatorImpl.java

@@ -34,6 +34,7 @@ import androidx.lifecycle.MutableLiveData;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.ERROR;
 import static org.briarproject.briar.android.util.UiUtils.observeForeverOnce;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_IMAGE_SIZE;
 
@@ -109,8 +110,8 @@ class AttachmentCreatorImpl implements AttachmentCreator {
 		// get and cache AttachmentItem for ImagePreview
 		try {
 			Attachment a = retriever.getMessageAttachment(h);
-			AttachmentItem item = retriever.getAttachmentItem(a, needsSize);
+			AttachmentItem item = retriever.createAttachmentItem(a, needsSize);
-			if (item.hasError()) throw new IOException();
+			if (item.getState() == ERROR) throw new IOException();
 			AttachmentItemResult itemResult =
 					new AttachmentItemResult(uri, item);
 			itemResults.add(itemResult);
@@ -167,13 +168,6 @@ class AttachmentCreatorImpl implements AttachmentCreator {
 	@Override
 	@UiThread
 	public void onAttachmentsSent(MessageId id) {
-		List<AttachmentItem> items = new ArrayList<>(itemResults.size());
-		for (AttachmentItemResult itemResult : itemResults) {
-			// check if we are trying to send attachment items with errors
-			if (itemResult.getItem() == null) throw new IllegalStateException();
-			items.add(itemResult.getItem());
-		}
-		retriever.cachePut(id, items);
 		resetState();
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentItem.java

@@ -7,24 +7,33 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
 
-import java.util.concurrent.atomic.AtomicLong;
-
 import javax.annotation.concurrent.Immutable;
 
 import androidx.annotation.Nullable;
 
+import static java.lang.System.arraycopy;
 import static java.util.Objects.requireNonNull;
+import static org.briarproject.bramble.util.StringUtils.toHexString;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.LOADING;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.MISSING;
 
 @Immutable
 @NotNullByDefault
 public class AttachmentItem implements Parcelable {
 
+	public enum State {
+		LOADING, MISSING, AVAILABLE, ERROR;
+
+		public boolean isFinal() {
+			return this == AVAILABLE || this == ERROR;
+		}
+	}
+
 	private final AttachmentHeader header;
 	private final int width, height;
 	private final String extension;
 	private final int thumbnailWidth, thumbnailHeight;
-	private final boolean hasError;
+	private final State state;
-	private final long instanceId;
 
 	public static final Creator<AttachmentItem> CREATOR =
 			new Creator<AttachmentItem>() {
@@ -39,19 +48,33 @@ public class AttachmentItem implements Parcelable {
 				}
 			};
 
-	private static final AtomicLong NEXT_INSTANCE_ID = new AtomicLong(0);
-
 	AttachmentItem(AttachmentHeader header, int width, int height,
 			String extension, int thumbnailWidth, int thumbnailHeight,
-			boolean hasError) {
+			State state) {
 		this.header = header;
 		this.width = width;
 		this.height = height;
 		this.extension = extension;
 		this.thumbnailWidth = thumbnailWidth;
 		this.thumbnailHeight = thumbnailHeight;
-		this.hasError = hasError;
+		this.state = state;
-		instanceId = NEXT_INSTANCE_ID.getAndIncrement();
+	}
+
+	/**
+	 * Use only for {@link State MISSING} or {@link State LOADING} items.
+	 */
+	AttachmentItem(AttachmentHeader header, int width, int height,
+			State state) {
+		this(header, width, height, "", width, height, state);
+		if (state != MISSING && state != LOADING)
+			throw new IllegalArgumentException();
+	}
+
+	/**
+	 * Use when the item does not need a size.
+	 */
+	AttachmentItem(AttachmentHeader header, String extension, State state) {
+		this(header, 0, 0, extension, 0, 0, state);
 	}
 
 	protected AttachmentItem(Parcel in) {
@@ -64,8 +87,7 @@ public class AttachmentItem implements Parcelable {
 		extension = requireNonNull(in.readString());
 		thumbnailWidth = in.readInt();
 		thumbnailHeight = in.readInt();
-		hasError = in.readByte() != 0;
+		state = State.valueOf(requireNonNull(in.readString()));
-		instanceId = in.readLong();
 		header = new AttachmentHeader(messageId, mimeType);
 	}
 
@@ -101,12 +123,20 @@ public class AttachmentItem implements Parcelable {
 		return thumbnailHeight;
 	}
 
-	public boolean hasError() {
+	public State getState() {
-		return hasError;
+		return state;
 	}
 
-	public String getTransitionName() {
+	public String getTransitionName(MessageId conversationItemId) {
-		return String.valueOf(instanceId);
+		int len = MessageId.LENGTH;
+		byte[] instanceId = new byte[len * 2];
+		arraycopy(header.getMessageId().getBytes(), 0, instanceId, 0, len);
+		arraycopy(conversationItemId.getBytes(), 0, instanceId, len, len);
+		return toHexString(instanceId);
+	}
+
+	boolean hasSize() {
+		return width != 0 && height != 0;
 	}
 
 	@Override
@@ -123,14 +153,15 @@ public class AttachmentItem implements Parcelable {
 		dest.writeString(extension);
 		dest.writeInt(thumbnailWidth);
 		dest.writeInt(thumbnailHeight);
-		dest.writeByte((byte) (hasError ? 1 : 0));
+		dest.writeString(state.name());
-		dest.writeLong(instanceId);
 	}
 
 	@Override
 	public boolean equals(@Nullable Object o) {
 		return o instanceof AttachmentItem &&
-				instanceId == ((AttachmentItem) o).instanceId;
+				header.getMessageId().equals(
+						((AttachmentItem) o).header.getMessageId()
+				);
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetriever.java

@@ -1,29 +1,56 @@
 package org.briarproject.briar.android.attachment;
 
+import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
+import org.briarproject.briar.api.messaging.PrivateMessageHeader;
+import org.briarproject.briar.api.messaging.event.AttachmentReceivedEvent;
 
 import java.io.InputStream;
 import java.util.List;
 
-import androidx.annotation.Nullable;
+import androidx.lifecycle.LiveData;
+
 
 @NotNullByDefault
 public interface AttachmentRetriever {
 
-	void cachePut(MessageId messageId, List<AttachmentItem> attachments);
+	@DatabaseExecutor
-
-	@Nullable
-	List<AttachmentItem> cacheGet(MessageId messageId);
-
 	Attachment getMessageAttachment(AttachmentHeader h) throws DbException;
 
+	/**
+	 * Returns a list of observable {@link LiveData}
+	 * that get updated as the state of their {@link AttachmentItem}s changes.
+	 */
+	List<LiveData<AttachmentItem>> getAttachmentItems(
+			PrivateMessageHeader messageHeader);
+
+	/**
+	 * Retrieves item size and adds the item to the cache, if available.
+	 * <p>
+	 * Use this to eagerly load the attachment size before it gets displayed.
+	 * This is needed for messages containing a single attachment.
+	 * Messages with more than one attachment use a standard size.
+	 */
+	@DatabaseExecutor
+	void cacheAttachmentItemWithSize(MessageId conversationMessageId,
+			AttachmentHeader h) throws DbException;
+
 	/**
 	 * Creates an {@link AttachmentItem} from the {@link Attachment}'s
 	 * {@link InputStream} which will be closed when this method returns.
 	 */
-	AttachmentItem getAttachmentItem(Attachment a, boolean needsSize);
+	AttachmentItem createAttachmentItem(Attachment a, boolean needsSize);
+
+	/**
+	 * Loads an {@link AttachmentItem}
+	 * that arrived via an {@link AttachmentReceivedEvent}
+	 * and notifies the associated {@link LiveData}.
+	 */
+	@DatabaseExecutor
+	void loadAttachmentItem(MessageId attachmentId);
+
 }

briar-android/src/main/java/org/briarproject/briar/android/attachment/AttachmentRetrieverImpl.java

@@ -1,25 +1,39 @@
 package org.briarproject.briar.android.attachment;
 
+import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.NoSuchMessageException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.briar.android.attachment.AttachmentItem.State;
 import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.MessagingManager;
+import org.briarproject.briar.api.messaging.PrivateMessageHeader;
 
 import java.io.BufferedInputStream;
 import java.io.InputStream;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
-import androidx.annotation.Nullable;
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
 
+import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.util.IoUtils.tryToClose;
+import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.AVAILABLE;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.ERROR;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.LOADING;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.MISSING;
 
 @NotNullByDefault
 class AttachmentRetrieverImpl implements AttachmentRetriever {
@@ -27,6 +41,8 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 	private static final Logger LOG =
 			getLogger(AttachmentRetrieverImpl.class.getName());
 
+	@DatabaseExecutor
+	private final Executor dbExecutor;
 	private final MessagingManager messagingManager;
 	private final ImageHelper imageHelper;
 	private final ImageSizeCalculator imageSizeCalculator;
@@ -34,13 +50,17 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 	private final int minWidth, maxWidth;
 	private final int minHeight, maxHeight;
 
-	private final Map<MessageId, List<AttachmentItem>> attachmentCache =
+	private final Map<MessageId, MutableLiveData<AttachmentItem>>
-			new ConcurrentHashMap<>();
+			itemsWithSize = new ConcurrentHashMap<>();
+	private final Map<MessageId, MutableLiveData<AttachmentItem>>
+			itemsWithoutSize = new ConcurrentHashMap<>();
 
 	@Inject
-	AttachmentRetrieverImpl(MessagingManager messagingManager,
+	AttachmentRetrieverImpl(@DatabaseExecutor Executor dbExecutor,
+			MessagingManager messagingManager,
 			AttachmentDimensions dimensions, ImageHelper imageHelper,
 			ImageSizeCalculator imageSizeCalculator) {
+		this.dbExecutor = dbExecutor;
 		this.messagingManager = messagingManager;
 		this.imageHelper = imageHelper;
 		this.imageSizeCalculator = imageSizeCalculator;
@@ -52,40 +72,130 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 	}
 
 	@Override
-	public void cachePut(MessageId messageId,
+	@DatabaseExecutor
-			List<AttachmentItem> attachments) {
-		attachmentCache.put(messageId, attachments);
-	}
-
-	@Override
-	@Nullable
-	public List<AttachmentItem> cacheGet(MessageId messageId) {
-		return attachmentCache.get(messageId);
-	}
-
-	@Override
 	public Attachment getMessageAttachment(AttachmentHeader h)
 			throws DbException {
 		return messagingManager.getAttachment(h);
 	}
 
 	@Override
-	public AttachmentItem getAttachmentItem(Attachment a, boolean needsSize) {
+	public List<LiveData<AttachmentItem>> getAttachmentItems(
-		AttachmentHeader h = a.getHeader();
+			PrivateMessageHeader messageHeader) {
-		if (!needsSize) {
+		List<AttachmentHeader> headers = messageHeader.getAttachmentHeaders();
-			String extension =
+		List<LiveData<AttachmentItem>> items = new ArrayList<>(headers.size());
-					imageHelper.getExtensionFromMimeType(h.getContentType());
+		boolean needsSize = headers.size() == 1;
-			boolean hasError = false;
+		for (AttachmentHeader h : headers) {
-			if (extension == null) {
+			// try cache for existing item live data
-				extension = "";
+			MutableLiveData<AttachmentItem> liveData;
-				hasError = true;
+			if (needsSize) liveData = itemsWithSize.get(h.getMessageId());
+			else {
+				// try items with size first, as they work as well
+				liveData = itemsWithSize.get(h.getMessageId());
+				if (liveData == null)
+					liveData = itemsWithoutSize.get(h.getMessageId());
 			}
-			return new AttachmentItem(h, 0, 0, extension, 0, 0, hasError);
+
+			// create new live data with LOADING item if cache miss
+			if (liveData == null) {
+				AttachmentItem item = new AttachmentItem(h,
+						defaultSize, defaultSize, LOADING);
+				final MutableLiveData<AttachmentItem> finalLiveData =
+						new MutableLiveData<>(item);
+				// kick-off loading of attachment, will post to live data
+				dbExecutor.execute(
+						() -> loadAttachmentItem(h, needsSize, finalLiveData));
+				// add new LiveData to cache
+				liveData = finalLiveData;
+				if (needsSize) itemsWithSize.put(h.getMessageId(), liveData);
+				else itemsWithoutSize.put(h.getMessageId(), liveData);
+			}
+			items.add(liveData);
+		}
+		return items;
+	}
+
+	@Override
+	@DatabaseExecutor
+	public void cacheAttachmentItemWithSize(MessageId conversationMessageId,
+			AttachmentHeader h) throws DbException {
+		try {
+			Attachment a = messagingManager.getAttachment(h);
+			AttachmentItem item = createAttachmentItem(a, true);
+			MutableLiveData<AttachmentItem> liveData =
+					new MutableLiveData<>(item);
+			itemsWithSize.put(h.getMessageId(), liveData);
+		} catch (NoSuchMessageException e) {
+			LOG.info("Attachment not received yet");
+		}
+	}
+
+	@Override
+	@DatabaseExecutor
+	public void loadAttachmentItem(MessageId attachmentId) {
+		// try to find LiveData for attachment in both caches
+		MutableLiveData<AttachmentItem> liveData;
+		boolean needsSize = true;
+		liveData = itemsWithSize.get(attachmentId);
+		if (liveData == null) {
+			needsSize = false;
+			liveData = itemsWithoutSize.get(attachmentId);
 		}
 
-		InputStream is = new BufferedInputStream(a.getStream());
+		// If no LiveData for the attachment exists,
-		Size size = imageSizeCalculator.getSize(is, h.getContentType());
+		// its message did not yet arrive and we can ignore it for now.
+		if (liveData == null) return;
 
+		// actually load the attachment item
+		AttachmentHeader h = requireNonNull(liveData.getValue()).getHeader();
+		loadAttachmentItem(h, needsSize, liveData);
+	}
+
+	/**
+	 * Loads an {@link AttachmentItem} from the database
+	 * and notifies the given {@link LiveData}.
+	 */
+	@DatabaseExecutor
+	private void loadAttachmentItem(AttachmentHeader h, boolean needsSize,
+			MutableLiveData<AttachmentItem> liveData) {
+		Attachment a;
+		AttachmentItem item;
+		try {
+			a = messagingManager.getAttachment(h);
+			item = createAttachmentItem(a, needsSize);
+		} catch (NoSuchMessageException e) {
+			LOG.info("Attachment not received yet");
+			item = new AttachmentItem(h, defaultSize, defaultSize, MISSING);
+		} catch (DbException e) {
+			logException(LOG, WARNING, e);
+			item = new AttachmentItem(h, "", ERROR);
+		}
+		liveData.postValue(item);
+	}
+
+	@Override
+	public AttachmentItem createAttachmentItem(Attachment a,
+			boolean needsSize) {
+		AttachmentItem item;
+		AttachmentHeader h = a.getHeader();
+		if (needsSize) {
+			InputStream is = new BufferedInputStream(a.getStream());
+			Size size = imageSizeCalculator.getSize(is, h.getContentType());
+			tryToClose(is, LOG, WARNING);
+			item = createAttachmentItem(h, size);
+		} else {
+			String extension =
+					imageHelper.getExtensionFromMimeType(h.getContentType());
+			State state = AVAILABLE;
+			if (extension == null) {
+				extension = "";
+				state = ERROR;
+			}
+			item = new AttachmentItem(h, extension, state);
+		}
+		return item;
+	}
+
+	private AttachmentItem createAttachmentItem(AttachmentHeader h, Size size) {
 		// calculate thumbnail size
 		Size thumbnailSize = new Size(defaultSize, defaultSize, size.mimeType);
 		if (!size.error) {
@@ -104,8 +214,9 @@ class AttachmentRetrieverImpl implements AttachmentRetriever {
 			hasError = true;
 		}
 		if (extension == null) extension = "";
-		return new AttachmentItem(h, size.width, size.height, extension,
+		State state = hasError ? ERROR : AVAILABLE;
-				thumbnailSize.width, thumbnailSize.height, hasError);
+		return new AttachmentItem(h, size.width, size.height,
+				extension, thumbnailSize.width, thumbnailSize.height, state);
 	}
 
 	private Size getThumbnailSize(int width, int height, String mimeType) {

briar-android/src/main/java/org/briarproject/briar/android/attachment/UnavailableItem.java

@@ -0,0 +1,36 @@
+package org.briarproject.briar.android.attachment;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.briar.api.messaging.AttachmentHeader;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+class UnavailableItem {
+
+	private final MessageId conversationMessageId;
+	private final AttachmentHeader header;
+	private final boolean needsSize;
+
+	UnavailableItem(MessageId conversationMessageId,
+			AttachmentHeader header, boolean needsSize) {
+		this.conversationMessageId = conversationMessageId;
+		this.header = header;
+		this.needsSize = needsSize;
+	}
+
+	MessageId getConversationMessageId() {
+		return conversationMessageId;
+	}
+
+	AttachmentHeader getHeader() {
+		return header;
+	}
+
+	boolean needsSize() {
+		return needsSize;
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogController.java

@@ -9,6 +9,7 @@ import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;
 
 import java.util.Collection;
 
+import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
 
 @NotNullByDefault
@@ -17,10 +18,7 @@ public interface BlogController extends BaseController {
 	void setGroupId(GroupId g);
 
 	@UiThread
-	void setBlogSharingListener(BlogSharingListener listener);
+	void setBlogSharingListener(@Nullable BlogSharingListener listener);
-
-	@UiThread
-	void unsetBlogSharingListener(BlogSharingListener listener);
 
 	void loadBlogPosts(
 			ResultExceptionHandler<Collection<BlogPostItem>, DbException> handler);

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogControllerImpl.java

@@ -96,15 +96,10 @@ class BlogControllerImpl extends BaseControllerImpl
 	}
 
 	@Override
-	public void setBlogSharingListener(BlogSharingListener listener) {
+	public void setBlogSharingListener(@Nullable BlogSharingListener listener) {
 		this.listener = listener;
 	}
 
-	@Override
-	public void unsetBlogSharingListener(BlogSharingListener listener) {
-		if (this.listener == listener) this.listener = null;
-	}
-
 	@Override
 	public void eventOccurred(Event e) {
 		if (groupId == null || listener == null)

briar-android/src/main/java/org/briarproject/briar/android/blog/BlogFragment.java

@@ -141,8 +141,7 @@ public class BlogFragment extends BaseFragment
 	@Override
 	public void onDestroy() {
 		super.onDestroy();
-		blogController.unsetBlogSharingListener(this);
+		blogController.setBlogSharingListener(null);
-		sharingController.unsetSharingListener(this);
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedController.java

@@ -7,6 +7,7 @@ import org.briarproject.briar.api.blog.Blog;
 
 import java.util.Collection;
 
+import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
 
 @NotNullByDefault
@@ -18,10 +19,7 @@ public interface FeedController extends BaseController {
 	void loadPersonalBlog(ResultExceptionHandler<Blog, DbException> handler);
 
 	@UiThread
-	void setFeedListener(FeedListener listener);
+	void setFeedListener(@Nullable FeedListener listener);
-
-	@UiThread
-	void unsetFeedListener(FeedListener listener);
 
 	@NotNullByDefault
 	interface FeedListener extends BlogListener {

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedControllerImpl.java

@@ -69,15 +69,10 @@ class FeedControllerImpl extends BaseControllerImpl implements FeedController {
 	}
 
 	@Override
-	public void setFeedListener(FeedListener listener) {
+	public void setFeedListener(@Nullable FeedListener listener) {
 		this.listener = listener;
 	}
 
-	@Override
-	public void unsetFeedListener(FeedListener listener) {
-		if (this.listener == listener) this.listener = null;
-	}
-
 	@Override
 	public void eventOccurred(Event e) {
 		if (listener == null) throw new IllegalStateException();

briar-android/src/main/java/org/briarproject/briar/android/blog/FeedFragment.java

@@ -134,7 +134,7 @@ public class FeedFragment extends BaseFragment implements
 	@Override
 	public void onDestroy() {
 		super.onDestroy();
-		feedController.unsetFeedListener(this);
+		feedController.setFeedListener(null);
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactItem.java

@@ -2,38 +2,35 @@ package org.briarproject.briar.android.contact;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.DISCONNECTED;
-
 @NotThreadSafe
 @NotNullByDefault
 public class ContactItem {
 
 	private final Contact contact;
-	private ConnectionStatus status;
+	private boolean connected;
 
 	public ContactItem(Contact contact) {
-		this(contact, DISCONNECTED);
+		this(contact, false);
 	}
 
-	public ContactItem(Contact contact, ConnectionStatus status) {
+	public ContactItem(Contact contact, boolean connected) {
 		this.contact = contact;
-		this.status = status;
+		this.connected = connected;
 	}
 
 	public Contact getContact() {
 		return contact;
 	}
 
-	ConnectionStatus getConnectionStatus() {
+	boolean isConnected() {
-		return status;
+		return connected;
 	}
 
-	void setConnectionStatus(ConnectionStatus status) {
+	void setConnected(boolean connected) {
-		this.status = status;
+		this.connected = connected;
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactItemViewHolder.java

@@ -7,7 +7,6 @@ import android.widget.TextView;
 
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
 
@@ -17,8 +16,6 @@ import androidx.annotation.UiThread;
 import androidx.recyclerview.widget.RecyclerView;
 import im.delight.android.identicons.IdenticonDrawable;
 
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.CONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.RECENTLY_CONNECTED;
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
 
 @UiThread
@@ -30,7 +27,7 @@ public class ContactItemViewHolder<I extends ContactItem>
 	protected final ImageView avatar;
 	protected final TextView name;
 	@Nullable
-	private final ImageView bulb;
+	protected final ImageView bulb;
 
 	public ContactItemViewHolder(View v) {
 		super(v);
@@ -50,13 +47,10 @@ public class ContactItemViewHolder<I extends ContactItem>
 
 		if (bulb != null) {
 			// online/offline
-			ConnectionStatus status = item.getConnectionStatus();
+			if (item.isConnected()) {
-			if (status == CONNECTED) {
+				bulb.setImageResource(R.drawable.contact_connected);
-				bulb.setImageResource(R.drawable.ic_connected);
-			} else if (status == RECENTLY_CONNECTED) {
-				bulb.setImageResource(R.drawable.ic_recently_connected);
 			} else {
-				bulb.setImageResource(R.drawable.ic_disconnected);
+				bulb.setImageResource(R.drawable.contact_disconnected);
 			}
 		}
 

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListAdapter.java

@@ -39,7 +39,7 @@ public class ContactListAdapter extends
 		if (c1.getTimestamp() != c2.getTimestamp()) {
 			return false;
 		}
-		return c1.getConnectionStatus() == c2.getConnectionStatus();
+		return c1.isConnected() == c2.isConnected();
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListFragment.java

@@ -25,8 +25,8 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
@@ -53,6 +53,7 @@ import javax.inject.Inject;
 import androidx.annotation.UiThread;
 import androidx.core.app.ActivityCompat;
 import androidx.core.app.ActivityOptionsCompat;
+import androidx.core.util.Pair;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial;
 import io.github.kobakei.materialfabspeeddial.FabSpeedDial.OnMenuItemClickListener;
@@ -60,7 +61,7 @@ import io.github.kobakei.materialfabspeeddial.FabSpeedDial.OnMenuItemClickListen
 import static android.os.Build.VERSION.SDK_INT;
 import static androidx.core.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
 import static androidx.core.view.ViewCompat.getTransitionName;
-import static com.google.android.material.snackbar.BaseTransientBottomBar.LENGTH_INDEFINITE;
+import static com.google.android.material.snackbar.Snackbar.LENGTH_INDEFINITE;
 import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
@@ -86,12 +87,7 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 
 	private ContactListAdapter adapter;
 	private BriarRecyclerView list;
-	/**
+	private Snackbar snackbar;
-	 * The Snackbar is non-null when shown and null otherwise.
-	 * Use {@link #showSnackBar()} and {@link #dismissSnackBar()} to interact.
-	 */
-	@Nullable
-	private Snackbar snackbar = null;
 
 	// Fields that are accessed from background threads must be volatile
 	@Inject
@@ -136,15 +132,26 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 					ContactId contactId = item.getContact().getId();
 					i.putExtra(CONTACT_ID, contactId.getInt());
 
-					Bundle options = null;
-					// work-around for android bug #224270
 					if (SDK_INT >= 23 && !isSamsung7()) {
-						options = makeTransitionOptions(view);
+						ContactListItemViewHolder holder =
-					}
+								(ContactListItemViewHolder) list
-					if (options == null) {
+										.getRecyclerView()
-						startActivity(i);
+										.findViewHolderForAdapterPosition(
+												adapter.findItemPosition(item));
+						Pair<View, String> avatar =
+								Pair.create(holder.avatar,
+										getTransitionName(holder.avatar));
+						Pair<View, String> bulb =
+								Pair.create(holder.bulb,
+										getTransitionName(holder.bulb));
+						ActivityOptionsCompat options =
+								makeSceneTransitionAnimation(getActivity(),
+										avatar, bulb);
+						ActivityCompat.startActivity(getActivity(), i,
+								options.toBundle());
 					} else {
-						ActivityCompat.startActivity(getActivity(), i, options);
+						// work-around for android bug #224270
+						startActivity(i);
 					}
 				};
 		adapter = new ContactListAdapter(requireContext(),
@@ -156,16 +163,14 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		list.setEmptyText(getString(R.string.no_contacts));
 		list.setEmptyAction(getString(R.string.no_contacts_action));
 
-		return contentView;
+		snackbar = new BriarSnackbarBuilder()
-	}
+				.setAction(R.string.show, v ->
+						startActivity(new Intent(getContext(),
+								PendingContactListActivity.class)))
+				.make(contentView, R.string.pending_contact_requests_snackbar,
+						LENGTH_INDEFINITE);
 
-	@Nullable
+		return contentView;
-	private Bundle makeTransitionOptions(View view) {
-		View avatar = view.findViewById(R.id.avatarView);
-		String name = requireNonNull(getTransitionName(avatar));
-		ActivityOptionsCompat options = makeSceneTransitionAnimation(
-				requireActivity(), view, name);
-		return options.toBundle();
 	}
 
 	@Override
@@ -198,9 +203,9 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		listener.runOnDbThread(() -> {
 			try {
 				if (contactManager.getPendingContacts().isEmpty()) {
-					runOnUiThreadUnlessDestroyed(this::dismissSnackBar);
+					runOnUiThreadUnlessDestroyed(() -> snackbar.dismiss());
 				} else {
-					runOnUiThreadUnlessDestroyed(this::showSnackBar);
+					runOnUiThreadUnlessDestroyed(() -> snackbar.show());
 				}
 			} catch (DbException e) {
 				logException(LOG, WARNING, e);
@@ -215,7 +220,6 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		adapter.clear();
 		list.showProgressBar();
 		list.stopPeriodicUpdate();
-		dismissSnackBar();
 	}
 
 	private void loadContacts() {
@@ -229,9 +233,9 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 						ContactId id = c.getId();
 						GroupCount count =
 								conversationManager.getGroupCount(id);
-						ConnectionStatus status = connectionRegistry
+						boolean connected =
-								.getConnectionStatus(c.getId());
+								connectionRegistry.isConnected(c.getId());
-						contacts.add(new ContactListItem(c, status, count));
+						contacts.add(new ContactListItem(c, connected, count));
 					} catch (NoSuchContactException e) {
 						// Continue
 					}
@@ -262,9 +266,10 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 		if (e instanceof ContactAddedEvent) {
 			LOG.info("Contact added, reloading");
 			loadContacts();
-		} else if (e instanceof ConnectionStatusChangedEvent) {
+		} else if (e instanceof ContactConnectedEvent) {
-			ConnectionStatusChangedEvent c = (ConnectionStatusChangedEvent) e;
+			setConnected(((ContactConnectedEvent) e).getContactId(), true);
-			setConnectionStatus(c.getContactId(), c.getConnectionStatus());
+		} else if (e instanceof ContactDisconnectedEvent) {
+			setConnected(((ContactDisconnectedEvent) e).getContactId(), false);
 		} else if (e instanceof ContactRemovedEvent) {
 			LOG.info("Contact removed, removing item");
 			removeItem(((ContactRemovedEvent) e).getContactId());
@@ -300,37 +305,14 @@ public class ContactListFragment extends BaseFragment implements EventListener,
 	}
 
 	@UiThread
-	private void setConnectionStatus(ContactId c, ConnectionStatus status) {
+	private void setConnected(ContactId c, boolean connected) {
 		adapter.incrementRevision();
 		int position = adapter.findItemPosition(c);
 		ContactListItem item = adapter.getItemAt(position);
 		if (item != null) {
-			item.setConnectionStatus(status);
+			item.setConnected(connected);
 			adapter.updateItemAt(position, item);
 		}
 	}
 
-	@UiThread
-	private void showSnackBar() {
-		if (snackbar != null) return;
-		View v = requireNonNull(getView());
-		int stringRes = R.string.pending_contact_requests_snackbar;
-		snackbar = new BriarSnackbarBuilder()
-				.setAction(R.string.show, view -> showPendingContactList())
-				.make(v, stringRes, LENGTH_INDEFINITE);
-		snackbar.show();
-	}
-
-	@UiThread
-	private void dismissSnackBar() {
-		if (snackbar == null) return;
-		snackbar.dismiss();
-		snackbar = null;
-	}
-
-	private void showPendingContactList() {
-		Intent i = new Intent(getContext(), PendingContactListActivity.class);
-		startActivity(i);
-	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListItem.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.contact;
 
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.api.client.MessageTracker.GroupCount;
 import org.briarproject.briar.api.conversation.ConversationMessageHeader;
 
@@ -16,9 +15,9 @@ public class ContactListItem extends ContactItem {
 	private long timestamp;
 	private int unread;
 
-	public ContactListItem(Contact contact, ConnectionStatus status,
+	public ContactListItem(Contact contact, boolean connected,
 			GroupCount count) {
-		super(contact, status);
+		super(contact, connected);
 		this.empty = count.getMsgCount() == 0;
 		this.unread = count.getUnreadCount();
 		this.timestamp = count.getLatestMsgTime();

briar-android/src/main/java/org/briarproject/briar/android/contact/ContactListItemViewHolder.java

@@ -7,6 +7,7 @@ import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
+import org.briarproject.briar.android.util.UiUtils;
 
 import java.util.Locale;
 
@@ -14,11 +15,8 @@ import javax.annotation.Nullable;
 
 import androidx.annotation.UiThread;
 
-import static android.view.View.INVISIBLE;
-import static android.view.View.VISIBLE;
 import static androidx.core.view.ViewCompat.setTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.formatDate;
-import static org.briarproject.briar.android.util.UiUtils.getAvatarTransitionName;
 
 @UiThread
 @NotNullByDefault
@@ -41,11 +39,10 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 		// unread count
 		int unreadCount = item.getUnreadCount();
 		if (unreadCount > 0) {
-			unread.setText(String.format(Locale.getDefault(), "%d",
+			unread.setText(String.format(Locale.getDefault(), "%d", unreadCount));
-					unreadCount));
+			unread.setVisibility(View.VISIBLE);
-			unread.setVisibility(VISIBLE);
 		} else {
-			unread.setVisibility(INVISIBLE);
+			unread.setVisibility(View.INVISIBLE);
 		}
 
 		// date of last message
@@ -57,7 +54,8 @@ class ContactListItemViewHolder extends ContactItemViewHolder<ContactListItem> {
 		}
 
 		ContactId c = item.getContact().getId();
-		setTransitionName(avatar, getAvatarTransitionName(c));
+		setTransitionName(avatar, UiUtils.getAvatarTransitionName(c));
+		setTransitionName(bulb, UiUtils.getBulbTransitionName(c));
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/PendingContactListViewModel.java

@@ -92,7 +92,7 @@ public class PendingContactListViewModel extends AndroidViewModel
 				Collection<Pair<PendingContact, PendingContactState>> pairs =
 						contactManager.getPendingContacts();
 				List<PendingContactItem> items = new ArrayList<>(pairs.size());
-				boolean online = pairs.isEmpty();
+				boolean online = items.isEmpty();
 				for (Pair<PendingContact, PendingContactState> pair : pairs) {
 					PendingContact p = pair.getFirst();
 					PendingContactState state = pair.getSecond();

briar-android/src/main/java/org/briarproject/briar/android/contact/add/remote/PendingContactViewHolder.java

@@ -54,6 +54,8 @@ class PendingContactViewHolder extends ViewHolder {
 				status.setText(R.string.waiting_for_contact_to_come_online);
 				break;
 			case OFFLINE:
+				color = ContextCompat
+						.getColor(status.getContext(), R.color.briar_yellow);
 				status.setText("");
 				break;
 			case CONNECTING:

briar-android/src/main/java/org/briarproject/briar/android/controller/SharingController.java

@@ -16,12 +16,6 @@ public interface SharingController {
 	@UiThread
 	void setSharingListener(SharingListener listener);
 
-	/**
-	 * Unsets the listener.
-	 */
-	@UiThread
-	void unsetSharingListener(SharingListener listener);
-
 	/**
 	 * Call this when your lifecycle starts,
 	 * so the listener will be called when information changes.

briar-android/src/main/java/org/briarproject/briar/android/controller/SharingControllerImpl.java

@@ -6,7 +6,8 @@ import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 
 import java.util.Collection;
 import java.util.HashSet;
@@ -17,8 +18,6 @@ import javax.inject.Inject;
 
 import androidx.annotation.UiThread;
 
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.CONNECTED;
-
 @NotNullByDefault
 public class SharingControllerImpl implements SharingController, EventListener {
 
@@ -44,11 +43,6 @@ public class SharingControllerImpl implements SharingController, EventListener {
 		this.listener = listener;
 	}
 
-	@Override
-	public void unsetSharingListener(SharingListener listener) {
-		if (this.listener == listener) this.listener = null;
-	}
-
 	@Override
 	public void onStart() {
 		eventBus.addListener(this);
@@ -61,14 +55,15 @@ public class SharingControllerImpl implements SharingController, EventListener {
 
 	@Override
 	public void eventOccurred(Event e) {
-		if (e instanceof ConnectionStatusChangedEvent) {
+		if (e instanceof ContactConnectedEvent) {
-			ConnectionStatusChangedEvent c = (ConnectionStatusChangedEvent) e;
+			setConnected(((ContactConnectedEvent) e).getContactId());
-			setConnectionStatus(c.getContactId());
+		} else if (e instanceof ContactDisconnectedEvent) {
+			setConnected(((ContactDisconnectedEvent) e).getContactId());
 		}
 	}
 
 	@UiThread
-	private void setConnectionStatus(ContactId c) {
+	private void setConnected(ContactId c) {
 		if (listener == null) throw new IllegalStateException();
 		if (contacts.contains(c)) {
 			int online = getOnlineCount();
@@ -95,9 +90,7 @@ public class SharingControllerImpl implements SharingController, EventListener {
 	public int getOnlineCount() {
 		int online = 0;
 		for (ContactId c : contacts) {
-			if (connectionRegistry.getConnectionStatus(c) == CONNECTED) {
+			if (connectionRegistry.isConnected(c)) online++;
-				online++;
-			}
 		}
 		return online;
 	}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationActivity.java

@@ -13,6 +13,7 @@ import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 import android.view.View;
+import android.widget.ImageView;
 import android.widget.TextView;
 import android.widget.Toast;
 
@@ -26,15 +27,14 @@ import org.briarproject.bramble.api.contact.event.ContactRemovedEvent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.NoSuchContactException;
-import org.briarproject.bramble.api.db.NoSuchMessageException;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
+import org.briarproject.bramble.api.plugin.event.ContactConnectedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionStatusChangedEvent;
+import org.briarproject.bramble.api.plugin.event.ContactDisconnectedEvent;
 import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
@@ -64,13 +64,13 @@ import org.briarproject.briar.api.client.ProtocolStateException;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.conversation.ConversationManager;
 import org.briarproject.briar.api.conversation.ConversationMessageHeader;
+import org.briarproject.briar.api.conversation.ConversationMessageVisitor;
 import org.briarproject.briar.api.conversation.ConversationRequest;
 import org.briarproject.briar.api.conversation.ConversationResponse;
 import org.briarproject.briar.api.conversation.DeletionResult;
 import org.briarproject.briar.api.conversation.event.ConversationMessageReceivedEvent;
 import org.briarproject.briar.api.forum.ForumSharingManager;
 import org.briarproject.briar.api.introduction.IntroductionManager;
-import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.AttachmentHeader;
 import org.briarproject.briar.api.messaging.MessagingManager;
 import org.briarproject.briar.api.messaging.PrivateMessageHeader;
@@ -96,6 +96,7 @@ import androidx.appcompat.widget.Toolbar;
 import androidx.core.app.ActivityCompat;
 import androidx.core.app.ActivityOptionsCompat;
 import androidx.core.content.ContextCompat;
+import androidx.lifecycle.LiveData;
 import androidx.lifecycle.Observer;
 import androidx.lifecycle.ViewModelProvider;
 import androidx.lifecycle.ViewModelProviders;
@@ -117,15 +118,11 @@ import static androidx.core.app.ActivityOptionsCompat.makeSceneTransitionAnimati
 import static androidx.core.view.ViewCompat.setTransitionName;
 import static androidx.lifecycle.Lifecycle.State.STARTED;
 import static androidx.recyclerview.widget.SortedList.INVALID_POSITION;
-import static java.util.Collections.emptyList;
-import static java.util.Collections.singletonList;
 import static java.util.Collections.sort;
 import static java.util.Objects.requireNonNull;
 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.api.plugin.ConnectionStatus.CONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.RECENTLY_CONNECTED;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -137,8 +134,10 @@ import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_INTRO
 import static org.briarproject.briar.android.conversation.ImageActivity.ATTACHMENTS;
 import static org.briarproject.briar.android.conversation.ImageActivity.ATTACHMENT_POSITION;
 import static org.briarproject.briar.android.conversation.ImageActivity.DATE;
+import static org.briarproject.briar.android.conversation.ImageActivity.ITEM_ID;
 import static org.briarproject.briar.android.conversation.ImageActivity.NAME;
 import static org.briarproject.briar.android.util.UiUtils.getAvatarTransitionName;
+import static org.briarproject.briar.android.util.UiUtils.getBulbTransitionName;
 import static org.briarproject.briar.android.util.UiUtils.observeOnce;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_ATTACHMENTS_PER_MESSAGE;
 import static org.briarproject.briar.api.messaging.MessagingConstants.MAX_PRIVATE_MESSAGE_TEXT_LENGTH;
@@ -185,8 +184,6 @@ public class ConversationActivity extends BriarActivity
 	volatile GroupInvitationManager groupInvitationManager;
 
 	private final Map<MessageId, String> textCache = new ConcurrentHashMap<>();
-	private final Map<MessageId, PrivateMessageHeader> missingAttachments =
-			new ConcurrentHashMap<>();
 	private final Observer<String> contactNameObserver = name -> {
 		requireNonNull(name);
 		loadMessages();
@@ -198,8 +195,8 @@ public class ConversationActivity extends BriarActivity
 	private ConversationAdapter adapter;
 	private Toolbar toolbar;
 	private CircleImageView toolbarAvatar;
+	private ImageView toolbarStatus;
 	private TextView toolbarTitle;
-	private TextView toolbarStatus;
 	private BriarRecyclerView list;
 	private LinearLayoutManager layoutManager;
 	private TextInputView textInputView;
@@ -237,8 +234,8 @@ public class ConversationActivity extends BriarActivity
 		// Custom Toolbar
 		toolbar = requireNonNull(setUpCustomToolbar(true));
 		toolbarAvatar = toolbar.findViewById(R.id.contactAvatar);
-		toolbarTitle = toolbar.findViewById(R.id.contactName);
 		toolbarStatus = toolbar.findViewById(R.id.contactStatus);
+		toolbarTitle = toolbar.findViewById(R.id.contactName);
 
 		observeOnce(viewModel.getContactAuthorId(), this, authorId -> {
 			requireNonNull(authorId);
@@ -257,12 +254,14 @@ public class ConversationActivity extends BriarActivity
 				this::onAddedPrivateMessage);
 
 		setTransitionName(toolbarAvatar, getAvatarTransitionName(contactId));
+		setTransitionName(toolbarStatus, getBulbTransitionName(contactId));
 
 		visitor = new ConversationVisitor(this, this, this,
 				viewModel.getContactDisplayName());
 		adapter = new ConversationAdapter(this, this);
 		list = findViewById(R.id.conversationView);
 		layoutManager = new LinearLayoutManager(this);
+		layoutManager.setStackFromEnd(true);
 		list.setLayoutManager(layoutManager);
 		list.setAdapter(adapter);
 		list.setEmptyText(getString(R.string.no_private_messages));
@@ -498,14 +497,14 @@ public class ConversationActivity extends BriarActivity
 
 	@UiThread
 	private void displayContactOnlineStatus() {
-		ConnectionStatus status =
+		if (connectionRegistry.isConnected(contactId)) {
-				connectionRegistry.getConnectionStatus(contactId);
+			toolbarStatus.setImageDrawable(ContextCompat.getDrawable(
-		if (status == CONNECTED) {
+					ConversationActivity.this, R.drawable.contact_online));
-			toolbarStatus.setText(R.string.online);
+			toolbarStatus.setContentDescription(getString(R.string.online));
-		} else if (status == RECENTLY_CONNECTED) {
-			toolbarStatus.setText(R.string.recently_online);
 		} else {
-			toolbarStatus.setText(R.string.offline);
+			toolbarStatus.setImageDrawable(ContextCompat.getDrawable(
+					ConversationActivity.this, R.drawable.contact_offline));
+			toolbarStatus.setContentDescription(getString(R.string.offline));
 		}
 	}
 
@@ -539,6 +538,7 @@ public class ConversationActivity extends BriarActivity
 		});
 	}
 
+	@DatabaseExecutor
 	private void eagerlyLoadMessageSize(PrivateMessageHeader h) {
 		try {
 			MessageId id = h.getId();
@@ -555,21 +555,11 @@ public class ConversationActivity extends BriarActivity
 			// images we use a grid so the size is fixed
 			List<AttachmentHeader> headers = h.getAttachmentHeaders();
 			if (headers.size() == 1) {
-				List<AttachmentItem> items = attachmentRetriever.cacheGet(id);
+				LOG.info("Eagerly loading image size for latest message");
-				if (items == null) {
+				AttachmentHeader header = headers.get(0);
-					LOG.info("Eagerly loading image size for latest message");
+				// get the item to retrieve its size
-					AttachmentHeader header = headers.get(0);
+				attachmentRetriever
-					try {
+						.cacheAttachmentItemWithSize(h.getId(), header);
-						Attachment a = attachmentRetriever
-								.getMessageAttachment(header);
-						AttachmentItem item =
-								attachmentRetriever.getAttachmentItem(a, true);
-						attachmentRetriever.cachePut(id, singletonList(item));
-					} catch (NoSuchMessageException e) {
-						LOG.info("Attachment not received yet");
-						missingAttachments.put(header.getMessageId(), h);
-					}
-				}
 			}
 		} catch (DbException e) {
 			logException(LOG, WARNING, e);
@@ -650,44 +640,12 @@ public class ConversationActivity extends BriarActivity
 				&& adapter.isScrolledToBottom(layoutManager);
 	}
 
-	private void loadMessageAttachments(PrivateMessageHeader h) {
+	private void updateMessageAttachment(MessageId m, AttachmentItem item) {
-		// TODO: Use placeholders for missing/invalid attachments
-		runOnDbThread(() -> {
-			try {
-				// TODO move getting the items off to IoExecutor, if size == 1
-				List<AttachmentHeader> headers = h.getAttachmentHeaders();
-				boolean needsSize = headers.size() == 1;
-				List<AttachmentItem> items = new ArrayList<>(headers.size());
-				for (AttachmentHeader header : headers) {
-					try {
-						Attachment a = attachmentRetriever
-								.getMessageAttachment(header);
-						AttachmentItem item = attachmentRetriever
-								.getAttachmentItem(a, needsSize);
-						items.add(item);
-					} catch (NoSuchMessageException e) {
-						LOG.info("Attachment not received yet");
-						missingAttachments.put(header.getMessageId(), h);
-						return;
-					}
-				}
-				// Don't cache items unless all are present and valid
-				attachmentRetriever.cachePut(h.getId(), items);
-				displayMessageAttachments(h.getId(), items);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		});
-	}
-
-	private void displayMessageAttachments(MessageId m,
-			List<AttachmentItem> items) {
 		runOnUiThreadUnlessDestroyed(() -> {
 			Pair<Integer, ConversationMessageItem> pair =
 					adapter.getMessageItem(m);
-			if (pair != null) {
+			if (pair != null && pair.getSecond().updateAttachments(item)) {
 				boolean scroll = shouldScrollWhenUpdatingMessage();
-				pair.getSecond().setAttachments(items);
 				adapter.notifyItemChanged(pair.getFirst());
 				if (scroll) scrollToBottom();
 			}
@@ -728,10 +686,16 @@ public class ConversationActivity extends BriarActivity
 				LOG.info("Messages acked");
 				markMessages(m.getMessageIds(), true, true);
 			}
-		} else if (e instanceof ConnectionStatusChangedEvent) {
+		} else if (e instanceof ContactConnectedEvent) {
-			ConnectionStatusChangedEvent c = (ConnectionStatusChangedEvent) e;
+			ContactConnectedEvent c = (ContactConnectedEvent) e;
 			if (c.getContactId().equals(contactId)) {
-				LOG.info("Connection status changed");
+				LOG.info("Contact connected");
+				displayContactOnlineStatus();
+			}
+		} else if (e instanceof ContactDisconnectedEvent) {
+			ContactDisconnectedEvent c = (ContactDisconnectedEvent) e;
+			if (c.getContactId().equals(contactId)) {
+				LOG.info("Contact disconnected");
 				displayContactOnlineStatus();
 			}
 		} else if (e instanceof ClientVersionUpdatedEvent) {
@@ -758,11 +722,8 @@ public class ConversationActivity extends BriarActivity
 
 	@UiThread
 	private void onAttachmentReceived(MessageId attachmentId) {
-		PrivateMessageHeader h = missingAttachments.remove(attachmentId);
+		runOnDbThread(
-		if (h != null) {
+				() -> attachmentRetriever.loadAttachmentItem(attachmentId));
-			LOG.info("Missing attachment received");
-			loadMessageAttachments(h);
-		}
 	}
 
 	@UiThread
@@ -773,7 +734,7 @@ public class ConversationActivity extends BriarActivity
 			observeOnce(viewModel.getContactDisplayName(), this,
 					name -> addConversationItem(h.accept(visitor)));
 		} else {
-			// visitor also loads message text (if existing)
+			// visitor also loads message text and attachments (if existing)
 			addConversationItem(h.accept(visitor));
 		}
 	}
@@ -1100,8 +1061,9 @@ public class ConversationActivity extends BriarActivity
 		i.putExtra(ATTACHMENT_POSITION, attachments.indexOf(item));
 		i.putExtra(NAME, name);
 		i.putExtra(DATE, messageItem.getTime());
+		i.putExtra(ITEM_ID, messageItem.getId().getBytes());
 		// restoring list position should not trigger android bug #224270
-		String transitionName = item.getTransitionName();
+		String transitionName = item.getTransitionName(messageItem.getId());
 		ActivityOptionsCompat options =
 				makeSceneTransitionAnimation(this, view, transitionName);
 		ActivityCompat.startActivity(this, i, options.toBundle());
@@ -1140,15 +1102,37 @@ public class ConversationActivity extends BriarActivity
 		return text;
 	}
 
+	/**
+	 * Called by {@link PrivateMessageHeader#accept(ConversationMessageVisitor)}
+	 */
 	@Override
 	public List<AttachmentItem> getAttachmentItems(PrivateMessageHeader h) {
-		List<AttachmentItem> attachments =
+		List<LiveData<AttachmentItem>> liveDataList =
-				attachmentRetriever.cacheGet(h.getId());
+				attachmentRetriever.getAttachmentItems(h);
-		if (attachments == null) {
+		List<AttachmentItem> items = new ArrayList<>(liveDataList.size());
-			loadMessageAttachments(h);
+		for (LiveData<AttachmentItem> liveData : liveDataList) {
-			return emptyList();
+			liveData.observe(this, new AttachmentObserver(h.getId(), liveData));
+			items.add(requireNonNull(liveData.getValue()));
+		}
+		return items;
+	}
+
+	private class AttachmentObserver implements Observer<AttachmentItem> {
+		private final MessageId conversationMessageId;
+		private final LiveData<AttachmentItem> liveData;
+
+		private AttachmentObserver(MessageId conversationMessageId,
+				LiveData<AttachmentItem> liveData) {
+			this.conversationMessageId = conversationMessageId;
+			this.liveData = liveData;
+		}
+
+		@Override
+		public void onChanged(AttachmentItem attachmentItem) {
+			updateMessageAttachment(conversationMessageId, attachmentItem);
+			if (attachmentItem.getState().isFinal())
+				liveData.removeObserver(this);
 		}
-		return attachments;
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/conversation/ConversationMessageItem.java

@@ -9,12 +9,13 @@ import java.util.List;
 import javax.annotation.concurrent.NotThreadSafe;
 
 import androidx.annotation.LayoutRes;
+import androidx.annotation.UiThread;
 
 @NotThreadSafe
 @NotNullByDefault
 class ConversationMessageItem extends ConversationItem {
 
-	private List<AttachmentItem> attachments;
+	private final List<AttachmentItem> attachments;
 
 	ConversationMessageItem(@LayoutRes int layoutRes, PrivateMessageHeader h,
 			List<AttachmentItem> attachments) {
@@ -26,8 +27,14 @@ class ConversationMessageItem extends ConversationItem {
 		return attachments;
 	}
 
-	void setAttachments(List<AttachmentItem> attachments) {
+	@UiThread
-		this.attachments = attachments;
+	boolean updateAttachments(AttachmentItem item) {
+		int pos = attachments.indexOf(item);
+		if (pos != -1 && attachments.get(pos).getState() != item.getState()) {
+			attachments.set(pos, item);
+			return true;
+		}
+		return false;
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageActivity.java

@@ -17,6 +17,7 @@ import com.google.android.material.appbar.AppBarLayout;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
@@ -69,6 +70,7 @@ public class ImageActivity extends BriarActivity
 	final static String ATTACHMENT_POSITION = "position";
 	final static String NAME = "name";
 	final static String DATE = "date";
+	final static String ITEM_ID = "itemId";
 
 	@RequiresApi(api = 16)
 	private final static int UI_FLAGS_DEFAULT =
@@ -82,6 +84,7 @@ public class ImageActivity extends BriarActivity
 	private AppBarLayout appBarLayout;
 	private ViewPager viewPager;
 	private List<AttachmentItem> attachments;
+	private MessageId conversationMessageId;
 
 	@Override
 	public void injectActivity(ActivityComponent component) {
@@ -136,6 +139,7 @@ public class ImageActivity extends BriarActivity
 		String date = formatDateAbsolute(this, time);
 		contactName.setText(name);
 		dateView.setText(date);
+		conversationMessageId = new MessageId(i.getByteArrayExtra(ITEM_ID));
 
 		// Set up image ViewPager
 		viewPager = findViewById(R.id.viewPager);
@@ -325,8 +329,8 @@ public class ImageActivity extends BriarActivity
 
 		@Override
 		public Fragment getItem(int position) {
-			Fragment f = ImageFragment
+			Fragment f = ImageFragment.newInstance(
-					.newInstance(attachments.get(position), isFirst);
+					attachments.get(position), conversationMessageId, isFirst);
 			isFirst = false;
 			return f;
 		}

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageAdapter.java

@@ -49,7 +49,8 @@ class ImageAdapter extends Adapter<ImageViewHolder> {
 	public ImageViewHolder onCreateViewHolder(ViewGroup viewGroup, int type) {
 		View v = LayoutInflater.from(viewGroup.getContext()).inflate(
 				R.layout.list_item_image, viewGroup, false);
-		return new ImageViewHolder(v, imageSize);
+		requireNonNull(conversationItem);
+		return new ImageViewHolder(v, imageSize, conversationItem.getId());
 	}
 
 	@Override
@@ -58,7 +59,7 @@ class ImageAdapter extends Adapter<ImageViewHolder> {
 		// get item
 		requireNonNull(conversationItem);
 		AttachmentItem item = items.get(position);
-		// set onClick listener
+		// set onClick listener, if not missing or error
 		imageViewHolder.itemView.setOnClickListener(v ->
 				listener.onAttachmentClicked(v, conversationItem, item)
 		);

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageFragment.java

@@ -15,6 +15,7 @@ import com.bumptech.glide.request.target.Target;
 import com.github.chrisbanes.photoview.PhotoView;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.BaseActivity;
 import org.briarproject.briar.android.attachment.AttachmentItem;
@@ -23,6 +24,7 @@ import org.briarproject.briar.android.conversation.glide.GlideApp;
 import javax.annotation.ParametersAreNonnullByDefault;
 import javax.inject.Inject;
 
+import androidx.annotation.DrawableRes;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 import androidx.lifecycle.ViewModelProvider;
@@ -32,27 +34,36 @@ import static android.os.Build.VERSION.SDK_INT;
 import static android.widget.ImageView.ScaleType.FIT_START;
 import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.AVAILABLE;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.ERROR;
 import static org.briarproject.briar.android.conversation.ImageActivity.ATTACHMENT_POSITION;
+import static org.briarproject.briar.android.conversation.ImageActivity.ITEM_ID;
 
 @MethodsNotNullByDefault
 @ParametersAreNonnullByDefault
-public class ImageFragment extends Fragment {
+public class ImageFragment extends Fragment
+		implements RequestListener<Drawable> {
 
 	private final static String IS_FIRST = "isFirst";
+	@DrawableRes
+	private static final int ERROR_RES = R.drawable.ic_image_broken;
 
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
 
 	private AttachmentItem attachment;
 	private boolean isFirst;
+	private MessageId conversationItemId;
 	private ImageViewModel viewModel;
 	private PhotoView photoView;
 
-	static ImageFragment newInstance(AttachmentItem a, boolean isFirst) {
+	static ImageFragment newInstance(AttachmentItem a,
+			MessageId conversationMessageId, boolean isFirst) {
 		ImageFragment f = new ImageFragment();
 		Bundle args = new Bundle();
 		args.putParcelable(ATTACHMENT_POSITION, a);
 		args.putBoolean(IS_FIRST, isFirst);
+		args.putByteArray(ITEM_ID, conversationMessageId.getBytes());
 		f.setArguments(args);
 		return f;
 	}
@@ -70,6 +81,8 @@ public class ImageFragment extends Fragment {
 		Bundle args = requireNonNull(getArguments());
 		attachment = requireNonNull(args.getParcelable(ATTACHMENT_POSITION));
 		isFirst = args.getBoolean(IS_FIRST);
+		conversationItemId =
+				new MessageId(requireNonNull(args.getByteArray(ITEM_ID)));
 	}
 
 	@Nullable
@@ -82,55 +95,72 @@ public class ImageFragment extends Fragment {
 
 		viewModel = ViewModelProviders.of(requireNonNull(getActivity()),
 				viewModelFactory).get(ImageViewModel.class);
+		viewModel.getOnAttachmentLoaded()
+				.observeEvent(this, this::onAttachmentLoaded);
 
 		photoView = v.findViewById(R.id.photoView);
 		photoView.setScaleLevels(1, 2, 4);
 		photoView.setOnClickListener(view -> viewModel.clickImage());
 
-		// Request Listener
+		if (attachment.getState() == AVAILABLE) {
-		RequestListener<Drawable> listener = new RequestListener<Drawable>() {
+			loadImage();
-
+			// postponed transition will be started when Image was loaded
-			@Override
+		} else if (attachment.getState() == ERROR) {
-			public boolean onLoadFailed(@Nullable GlideException e,
+			photoView.setImageResource(ERROR_RES);
-					Object model, Target<Drawable> target,
+			startPostponedTransition();
-					boolean isFirstResource) {
+		} else {
-				if (getActivity() != null && isFirst)
+			photoView.setImageResource(R.drawable.ic_image_missing);
-					getActivity().supportStartPostponedEnterTransition();
+			startPostponedTransition();
-				return false;
+		}
-			}
-
-			@Override
-			public boolean onResourceReady(Drawable resource, Object model,
-					Target<Drawable> target, DataSource dataSource,
-					boolean isFirstResource) {
-				if (SDK_INT >= 21 && !(resource instanceof Animatable)) {
-					// set transition name only when not animatable,
-					// because the animation won't start otherwise
-					photoView.setTransitionName(
-							attachment.getTransitionName());
-				}
-				// Move image to the top if overlapping toolbar
-				if (viewModel.isOverlappingToolbar(photoView, resource)) {
-					photoView.setScaleType(FIT_START);
-				}
-				if (getActivity() != null && isFirst) {
-					getActivity().supportStartPostponedEnterTransition();
-				}
-				return false;
-			}
-		};
-
-		// Load Image
-		GlideApp.with(this)
-				.load(attachment)
-				// TODO allow if size < maxTextureSize ?
-//				.override(SIZE_ORIGINAL)
-				.diskCacheStrategy(NONE)
-				.error(R.drawable.ic_image_broken)
-				.addListener(listener)
-				.into(photoView);
 
 		return v;
 	}
 
+	private void loadImage() {
+		GlideApp.with(this)
+				.load(attachment)
+				// TODO allow if size < maxTextureSize ?
+//					.override(SIZE_ORIGINAL)
+				.diskCacheStrategy(NONE)
+				.error(ERROR_RES)
+				.addListener(this)
+				.into(photoView);
+	}
+
+	private void onAttachmentLoaded(MessageId messageId) {
+		if (attachment.getMessageId().equals(messageId)) loadImage();
+	}
+
+	@Override
+	public boolean onLoadFailed(@Nullable GlideException e,
+			Object model, Target<Drawable> target,
+			boolean isFirstResource) {
+		startPostponedTransition();
+		return false;
+	}
+
+	@Override
+	public boolean onResourceReady(Drawable resource, Object model,
+			Target<Drawable> target, DataSource dataSource,
+			boolean isFirstResource) {
+		if (SDK_INT >= 21 && !(resource instanceof Animatable)) {
+			// set transition name only when not animatable,
+			// because the animation won't start otherwise
+			photoView.setTransitionName(
+					attachment.getTransitionName(conversationItemId));
+		}
+		// Move image to the top if overlapping toolbar
+		if (viewModel.isOverlappingToolbar(photoView, resource)) {
+			photoView.setScaleType(FIT_START);
+		}
+		startPostponedTransition();
+		return false;
+	}
+
+	private void startPostponedTransition() {
+		if (getActivity() != null && isFirst) {
+			getActivity().supportStartPostponedEnterTransition();
+		}
+	}
+
 }

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageViewHolder.java

@@ -7,6 +7,7 @@ import android.widget.ImageView;
 import com.bumptech.glide.load.Transformation;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.attachment.AttachmentItem;
 import org.briarproject.briar.android.conversation.glide.BriarImageTransformation;
@@ -18,8 +19,12 @@ import androidx.recyclerview.widget.RecyclerView.ViewHolder;
 import androidx.recyclerview.widget.StaggeredGridLayoutManager.LayoutParams;
 
 import static android.os.Build.VERSION.SDK_INT;
+import static android.widget.ImageView.ScaleType.CENTER_CROP;
+import static android.widget.ImageView.ScaleType.FIT_CENTER;
 import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
 import static com.bumptech.glide.load.resource.drawable.DrawableTransitionOptions.withCrossFade;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.AVAILABLE;
+import static org.briarproject.briar.android.attachment.AttachmentItem.State.ERROR;
 
 @NotNullByDefault
 class ImageViewHolder extends ViewHolder {
@@ -29,25 +34,33 @@ class ImageViewHolder extends ViewHolder {
 
 	protected final ImageView imageView;
 	private final int imageSize;
+	private final MessageId conversationItemId;
 
-	ImageViewHolder(View v, int imageSize) {
+	ImageViewHolder(View v, int imageSize, MessageId conversationItemId) {
 		super(v);
 		imageView = v.findViewById(R.id.imageView);
 		this.imageSize = imageSize;
+		this.conversationItemId = conversationItemId;
 	}
 
 	void bind(AttachmentItem attachment, Radii r, boolean single,
 			boolean needsStretch) {
-		if (attachment.hasError()) {
+		setImageViewDimensions(attachment, single, needsStretch);
-			GlideApp.with(imageView)
+		if (attachment.getState() != AVAILABLE) {
-					.clear(imageView);
+			GlideApp.with(imageView).clear(imageView);
-			imageView.setImageResource(ERROR_RES);
+			if (attachment.getState() == ERROR) {
-		} else {
+				imageView.setImageResource(ERROR_RES);
-			setImageViewDimensions(attachment, single, needsStretch);
+			} else {
-			loadImage(attachment, r);
+				imageView.setImageResource(R.drawable.ic_image_missing);
-			if (SDK_INT >= 21) {
-				imageView.setTransitionName(attachment.getTransitionName());
 			}
+			imageView.setScaleType(FIT_CENTER);
+		} else {
+			loadImage(attachment, r);
+			imageView.setScaleType(CENTER_CROP);
+		}
+		if (SDK_INT >= 21) {
+			imageView.setTransitionName(
+					attachment.getTransitionName(conversationItemId));
 		}
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/conversation/ImageViewModel.java

@@ -7,13 +7,18 @@ import android.view.View;
 
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventBus;
+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.sync.MessageId;
 import org.briarproject.briar.android.attachment.AttachmentItem;
 import org.briarproject.briar.android.viewmodel.LiveEvent;
 import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
 import org.briarproject.briar.api.messaging.Attachment;
 import org.briarproject.briar.api.messaging.MessagingManager;
+import org.briarproject.briar.api.messaging.event.AttachmentReceivedEvent;
 
 import java.io.File;
 import java.io.FileOutputStream;
@@ -41,16 +46,19 @@ import static org.briarproject.bramble.util.IoUtils.copyAndClose;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 @NotNullByDefault
-public class ImageViewModel extends AndroidViewModel {
+public class ImageViewModel extends AndroidViewModel implements EventListener {
 
 	private static Logger LOG = getLogger(ImageViewModel.class.getName());
 
 	private final MessagingManager messagingManager;
+	private final EventBus eventBus;
 	@DatabaseExecutor
 	private final Executor dbExecutor;
 	@IoExecutor
 	private final Executor ioExecutor;
 
+	private final MutableLiveEvent<MessageId> attachmentLoaded =
+			new MutableLiveEvent<>();
 	/**
 	 * true means there was an error saving the image, false if image was saved.
 	 */
@@ -62,13 +70,34 @@ public class ImageViewModel extends AndroidViewModel {
 
 	@Inject
 	ImageViewModel(Application application,
-			MessagingManager messagingManager,
+			MessagingManager messagingManager, EventBus eventBus,
 			@DatabaseExecutor Executor dbExecutor,
 			@IoExecutor Executor ioExecutor) {
 		super(application);
 		this.messagingManager = messagingManager;
+		this.eventBus = eventBus;
 		this.dbExecutor = dbExecutor;
 		this.ioExecutor = ioExecutor;
+
+		eventBus.addListener(this);
+	}
+
+	@Override
+	protected void onCleared() {
+		super.onCleared();
+		eventBus.removeListener(this);
+	}
+
+	@Override
+	public void eventOccurred(Event e) {
+		if (e instanceof AttachmentReceivedEvent) {
+			attachmentLoaded
+					.postEvent(((AttachmentReceivedEvent) e).getMessageId());
+		}
+	}
+
+	LiveEvent<MessageId> getOnAttachmentLoaded() {
+		return attachmentLoaded;
 	}
 
 	void clickImage() {

briar-android/src/main/java/org/briarproject/briar/android/introduction/ContactChooserFragment.java

@@ -12,7 +12,6 @@ import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
@@ -74,8 +73,7 @@ public class ContactChooserFragment extends BaseFragment {
 	}
 
 	@Override
-	public View onCreateView(LayoutInflater inflater,
+	public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container,
-			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 
 		View contentView = inflater.inflate(R.layout.list, container, false);
@@ -129,9 +127,9 @@ public class ContactChooserFragment extends BaseFragment {
 						ContactId id = c.getId();
 						GroupCount count =
 								conversationManager.getGroupCount(id);
-						ConnectionStatus status = connectionRegistry
+						boolean connected =
-								.getConnectionStatus(c.getId());
+								connectionRegistry.isConnected(c.getId());
-						contacts.add(new ContactListItem(c, status, count));
+						contacts.add(new ContactListItem(c, connected, count));
 					}
 				}
 				displayContacts(contacts);

briar-android/src/main/java/org/briarproject/briar/android/login/ChangePasswordActivity.java

@@ -15,33 +15,27 @@ import android.widget.Toast;
 
 import com.google.android.material.textfield.TextInputLayout;
 
-import org.briarproject.bramble.api.crypto.DecryptionResult;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
+import org.briarproject.briar.android.controller.handler.UiResultHandler;
+import org.briarproject.briar.android.util.UiUtils;
 
 import javax.inject.Inject;
 
-import androidx.annotation.VisibleForTesting;
+import androidx.annotation.NonNull;
-import androidx.lifecycle.ViewModelProvider;
-import androidx.lifecycle.ViewModelProviders;
 
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
-import static android.widget.Toast.LENGTH_LONG;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.KEY_STRENGTHENER_ERROR;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.SUCCESS;
 import static org.briarproject.bramble.api.crypto.PasswordStrengthEstimator.QUITE_WEAK;
-import static org.briarproject.briar.android.login.LoginUtils.createKeyStrengthenerErrorDialog;
 import static org.briarproject.briar.android.util.UiUtils.hideSoftKeyboard;
-import static org.briarproject.briar.android.util.UiUtils.setError;
 import static org.briarproject.briar.android.util.UiUtils.showSoftKeyboard;
 
 public class ChangePasswordActivity extends BriarActivity
 		implements OnClickListener, OnEditorActionListener {
 
 	@Inject
-	ViewModelProvider.Factory viewModelFactory;
+	protected ChangePasswordController passwordController;
 
 	private TextInputLayout currentPasswordEntryWrapper;
 	private TextInputLayout newPasswordEntryWrapper;
@@ -53,17 +47,11 @@ public class ChangePasswordActivity extends BriarActivity
 	private Button changePasswordButton;
 	private ProgressBar progress;
 
-	@VisibleForTesting
-	ChangePasswordViewModel viewModel;
-
 	@Override
 	public void onCreate(Bundle state) {
 		super.onCreate(state);
 		setContentView(R.layout.activity_change_password);
 
-		viewModel = ViewModelProviders.of(this, viewModelFactory)
-				.get(ChangePasswordViewModel.class);
-
 		currentPasswordEntryWrapper =
 				findViewById(R.id.current_password_entry_wrapper);
 		newPasswordEntryWrapper = findViewById(R.id.new_password_entry_wrapper);
@@ -114,12 +102,13 @@ public class ChangePasswordActivity extends BriarActivity
 		String firstPassword = newPassword.getText().toString();
 		String secondPassword = newPasswordConfirmation.getText().toString();
 		boolean passwordsMatch = firstPassword.equals(secondPassword);
-		float strength = viewModel.estimatePasswordStrength(firstPassword);
+		float strength =
+				passwordController.estimatePasswordStrength(firstPassword);
 		strengthMeter.setStrength(strength);
-		setError(newPasswordEntryWrapper,
+		UiUtils.setError(newPasswordEntryWrapper,
 				getString(R.string.password_too_weak),
 				firstPassword.length() > 0 && strength < QUITE_WEAK);
-		setError(newPasswordConfirmationWrapper,
+		UiUtils.setError(newPasswordConfirmationWrapper,
 				getString(R.string.passwords_do_not_match),
 				secondPassword.length() > 0 && !passwordsMatch);
 		changePasswordButton.setEnabled(
@@ -138,34 +127,32 @@ public class ChangePasswordActivity extends BriarActivity
 		// Replace the button with a progress bar
 		changePasswordButton.setVisibility(INVISIBLE);
 		progress.setVisibility(VISIBLE);
-
+		passwordController.changePassword(currentPassword.getText().toString(),
-		String curPwd = currentPassword.getText().toString();
+				newPassword.getText().toString(),
-		String newPwd = newPassword.getText().toString();
+				new UiResultHandler<Boolean>(this) {
-		viewModel.changePassword(curPwd, newPwd).observeEvent(this, result -> {
+					@Override
-					if (result == SUCCESS) {
+					public void onResultUi(@NonNull Boolean result) {
-						Toast.makeText(ChangePasswordActivity.this,
+						if (result) {
-								R.string.password_changed,
+							Toast.makeText(ChangePasswordActivity.this,
-								LENGTH_LONG).show();
+									R.string.password_changed,
-						setResult(RESULT_OK);
+									Toast.LENGTH_LONG).show();
-						supportFinishAfterTransition();
+							setResult(RESULT_OK);
-					} else {
+							supportFinishAfterTransition();
-						tryAgain(result);
+						} else {
+							tryAgain();
+						}
 					}
-				}
+				});
-		);
 	}
 
-	private void tryAgain(DecryptionResult result) {
+	private void tryAgain() {
+		UiUtils.setError(currentPasswordEntryWrapper,
+				getString(R.string.try_again), true);
 		changePasswordButton.setVisibility(VISIBLE);
 		progress.setVisibility(INVISIBLE);
-		if (result == KEY_STRENGTHENER_ERROR) {
+		currentPassword.setText("");
-			createKeyStrengthenerErrorDialog(this).show();
+
-		} else {
+		// show the keyboard again
-			setError(currentPasswordEntryWrapper,
+		showSoftKeyboard(currentPassword);
-					getString(R.string.try_again), true);
-			currentPassword.setText("");
-			// show the keyboard again
-			showSoftKeyboard(currentPassword);
-		}
 	}
 }

briar-android/src/main/java/org/briarproject/briar/android/login/ChangePasswordControllerImpl.java

@@ -0,0 +1,43 @@
+package org.briarproject.briar.android.login;
+
+import org.briarproject.bramble.api.account.AccountManager;
+import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.android.controller.handler.ResultHandler;
+
+import java.util.concurrent.Executor;
+
+import javax.inject.Inject;
+
+@NotNullByDefault
+public class ChangePasswordControllerImpl implements ChangePasswordController {
+
+	protected final AccountManager accountManager;
+	protected final Executor ioExecutor;
+	private final PasswordStrengthEstimator strengthEstimator;
+
+	@Inject
+	ChangePasswordControllerImpl(AccountManager accountManager,
+			@IoExecutor Executor ioExecutor,
+			PasswordStrengthEstimator strengthEstimator) {
+		this.accountManager = accountManager;
+		this.ioExecutor = ioExecutor;
+		this.strengthEstimator = strengthEstimator;
+	}
+
+	@Override
+	public float estimatePasswordStrength(String password) {
+		return strengthEstimator.estimateStrength(password);
+	}
+
+	@Override
+	public void changePassword(String oldPassword, String newPassword,
+			ResultHandler<Boolean> resultHandler) {
+		ioExecutor.execute(() -> {
+			boolean changed =
+					accountManager.changePassword(oldPassword, newPassword);
+			resultHandler.onResult(changed);
+		});
+	}
+}

briar-android/src/main/java/org/briarproject/briar/android/login/ChangePasswordViewModel.java

@@ -1,53 +0,0 @@
-package org.briarproject.briar.android.login;
-
-import org.briarproject.bramble.api.account.AccountManager;
-import org.briarproject.bramble.api.crypto.DecryptionException;
-import org.briarproject.bramble.api.crypto.DecryptionResult;
-import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.briar.android.viewmodel.LiveEvent;
-import org.briarproject.briar.android.viewmodel.MutableLiveEvent;
-
-import java.util.concurrent.Executor;
-
-import javax.inject.Inject;
-
-import androidx.lifecycle.ViewModel;
-
-import static org.briarproject.bramble.api.crypto.DecryptionResult.SUCCESS;
-
-@NotNullByDefault
-public class ChangePasswordViewModel extends ViewModel {
-
-	private final AccountManager accountManager;
-	private final Executor ioExecutor;
-	private final PasswordStrengthEstimator strengthEstimator;
-
-	@Inject
-	ChangePasswordViewModel(AccountManager accountManager,
-			@IoExecutor Executor ioExecutor,
-			PasswordStrengthEstimator strengthEstimator) {
-		this.accountManager = accountManager;
-		this.ioExecutor = ioExecutor;
-		this.strengthEstimator = strengthEstimator;
-	}
-
-	float estimatePasswordStrength(String password) {
-		return strengthEstimator.estimateStrength(password);
-	}
-
-	LiveEvent<DecryptionResult> changePassword(String oldPassword,
-			String newPassword) {
-		MutableLiveEvent<DecryptionResult> result = new MutableLiveEvent<>();
-		ioExecutor.execute(() -> {
-			try {
-				accountManager.changePassword(oldPassword, newPassword);
-				result.postEvent(SUCCESS);
-			} catch (DecryptionException e) {
-				result.postEvent(e.getDecryptionResult());
-			}
-		});
-		return result;
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/login/LoginModule.java

@@ -1,23 +0,0 @@
-package org.briarproject.briar.android.login;
-
-import org.briarproject.briar.android.viewmodel.ViewModelKey;
-
-import androidx.lifecycle.ViewModel;
-import dagger.Binds;
-import dagger.Module;
-import dagger.multibindings.IntoMap;
-
-@Module
-public abstract class LoginModule {
-
-	@Binds
-	@IntoMap
-	@ViewModelKey(StartupViewModel.class)
-	abstract ViewModel bindStartupViewModel(StartupViewModel viewModel);
-
-	@Binds
-	@IntoMap
-	@ViewModelKey(ChangePasswordViewModel.class)
-	abstract ViewModel bindChangePasswordViewModel(
-			ChangePasswordViewModel viewModel);
-}

briar-android/src/main/java/org/briarproject/briar/android/login/LoginUtils.java

@@ -1,30 +0,0 @@
-package org.briarproject.briar.android.login;
-
-import android.content.Context;
-import android.graphics.drawable.Drawable;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.briar.R;
-
-import androidx.appcompat.app.AlertDialog;
-
-import static androidx.core.content.ContextCompat.getColor;
-import static androidx.core.content.ContextCompat.getDrawable;
-import static androidx.core.graphics.drawable.DrawableCompat.setTint;
-import static java.util.Objects.requireNonNull;
-
-@NotNullByDefault
-class LoginUtils {
-
-	static AlertDialog createKeyStrengthenerErrorDialog(Context ctx) {
-		AlertDialog.Builder builder =
-				new AlertDialog.Builder(ctx, R.style.BriarDialogTheme);
-		Drawable icon = getDrawable(ctx, R.drawable.alerts_and_states_error);
-		setTint(requireNonNull(icon), getColor(ctx, R.color.color_primary));
-		builder.setIcon(icon);
-		builder.setTitle(R.string.dialog_title_cannot_check_password);
-		builder.setMessage(R.string.dialog_message_cannot_check_password);
-		builder.setPositiveButton(R.string.ok, null);
-		return builder.create();
-	}
-}

briar-android/src/main/java/org/briarproject/briar/android/login/PasswordFragment.java

@@ -12,7 +12,6 @@ import android.widget.ProgressBar;
 import com.google.android.material.textfield.TextInputEditText;
 import com.google.android.material.textfield.TextInputLayout;
 
-import org.briarproject.bramble.api.crypto.DecryptionResult;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.briar.R;
@@ -29,9 +28,6 @@ import androidx.lifecycle.ViewModelProviders;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.KEY_STRENGTHENER_ERROR;
-import static org.briarproject.bramble.api.crypto.DecryptionResult.SUCCESS;
-import static org.briarproject.briar.android.login.LoginUtils.createKeyStrengthenerErrorDialog;
 import static org.briarproject.briar.android.util.UiUtils.enterPressed;
 import static org.briarproject.briar.android.util.UiUtils.hideSoftKeyboard;
 import static org.briarproject.briar.android.util.UiUtils.setError;
@@ -62,13 +58,12 @@ public class PasswordFragment extends BaseFragment implements TextWatcher {
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 		View v = inflater.inflate(R.layout.fragment_password, container,
-				false);
+						false);
 
 		viewModel = ViewModelProviders.of(requireActivity(), viewModelFactory)
 				.get(StartupViewModel.class);
-
+		viewModel.getPasswordValidated().observeEvent(this, valid -> {
-		viewModel.getPasswordValidated().observeEvent(this, result -> {
+			if (!valid) onPasswordInvalid();
-			if (result != SUCCESS) onPasswordInvalid(result);
 		});
 
 		signInButton = v.findViewById(R.id.btn_sign_in);
@@ -112,20 +107,18 @@ public class PasswordFragment extends BaseFragment implements TextWatcher {
 		viewModel.validatePassword(password.getText().toString());
 	}
 
-	private void onPasswordInvalid(DecryptionResult result) {
+	private void onPasswordInvalid() {
+		setError(input, getString(R.string.try_again), true);
 		signInButton.setVisibility(VISIBLE);
 		progress.setVisibility(INVISIBLE);
-		if (result == KEY_STRENGTHENER_ERROR) {
+		password.setText(null);
-			createKeyStrengthenerErrorDialog(requireContext()).show();
+
-		} else {
+		// show the keyboard again
-			setError(input, getString(R.string.try_again), true);
+		showSoftKeyboard(password);
-			password.setText(null);
-			// show the keyboard again
-			showSoftKeyboard(password);
-		}
 	}
 
-	private void onForgottenPasswordClick() {
+	public void onForgottenPasswordClick() {
+		// TODO Encapsulate the dialog in a re-usable fragment
 		AlertDialog.Builder builder = new AlertDialog.Builder(requireContext(),
 				R.style.BriarDialogTheme);
 		builder.setTitle(R.string.dialog_title_lost_password);

briar-android/src/main/java/org/briarproject/briar/android/login/StartupViewModel.java

@@ -3,8 +3,6 @@ package org.briarproject.briar.android.login;
 import android.app.Application;
 
 import org.briarproject.bramble.api.account.AccountManager;
-import org.briarproject.bramble.api.crypto.DecryptionException;
-import org.briarproject.bramble.api.crypto.DecryptionResult;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventListener;
@@ -26,7 +24,6 @@ import androidx.lifecycle.AndroidViewModel;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
-import static org.briarproject.bramble.api.crypto.DecryptionResult.SUCCESS;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.COMPACTING_DATABASE;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.MIGRATING_DATABASE;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STARTING_SERVICES;
@@ -49,7 +46,7 @@ public class StartupViewModel extends AndroidViewModel
 	@IoExecutor
 	private final Executor ioExecutor;
 
-	private final MutableLiveEvent<DecryptionResult> passwordValidated =
+	private final MutableLiveEvent<Boolean> passwordValidated =
 			new MutableLiveEvent<>();
 	private final MutableLiveEvent<Boolean> accountDeleted =
 			new MutableLiveEvent<>();
@@ -108,17 +105,13 @@ public class StartupViewModel extends AndroidViewModel
 
 	void validatePassword(String password) {
 		ioExecutor.execute(() -> {
-			try {
+			boolean signedIn = accountManager.signIn(password);
-				accountManager.signIn(password);
+			passwordValidated.postEvent(signedIn);
-				passwordValidated.postEvent(SUCCESS);
+			if (signedIn) state.postValue(SIGNED_IN);
-				state.postValue(SIGNED_IN);
-			} catch (DecryptionException e) {
-				passwordValidated.postEvent(e.getDecryptionResult());
-			}
 		});
 	}
 
-	LiveEvent<DecryptionResult> getPasswordValidated() {
+	LiveEvent<Boolean> getPasswordValidated() {
 		return passwordValidated;
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListController.java

@@ -10,6 +10,8 @@ import org.briarproject.briar.api.privategroup.GroupMessageHeader;
 
 import java.util.Collection;
 
+import javax.annotation.Nullable;
+
 import androidx.annotation.UiThread;
 
 @NotNullByDefault
@@ -19,10 +21,7 @@ interface GroupListController extends DbController {
 	 * The listener must be set right after the controller was injected
 	 */
 	@UiThread
-	void setGroupListListener(GroupListListener listener);
+	void setGroupListListener(@Nullable GroupListListener listener);
-
-	@UiThread
-	void unsetGroupListListener(GroupListListener listener);
 
 	@UiThread
 	void onStart();

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListControllerImpl.java

@@ -80,15 +80,10 @@ class GroupListControllerImpl extends DbControllerImpl
 	}
 
 	@Override
-	public void setGroupListListener(GroupListListener listener) {
+	public void setGroupListListener(@Nullable GroupListListener listener) {
 		this.listener = listener;
 	}
 
-	@Override
-	public void unsetGroupListListener(GroupListListener listener) {
-		if (this.listener == listener) this.listener = null;
-	}
-
 	@Override
 	@CallSuper
 	public void onStart() {

briar-android/src/main/java/org/briarproject/briar/android/privategroup/list/GroupListFragment.java

@@ -112,7 +112,7 @@ public class GroupListFragment extends BaseFragment implements
 	@Override
 	public void onDestroy() {
 		super.onDestroy();
-		controller.unsetGroupListListener(this);
+		controller.setGroupListListener(null);
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/GroupMemberListActivity.java

@@ -99,7 +99,7 @@ public class GroupMemberListActivity extends BriarActivity
 				supportFinishAfterTransition();
 			}
 		}
-		// TODO ConnectionStatusChangedEvent
+		// TODO ContactConnectedEvent and ContactDisconnectedEvent
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/GroupMemberListControllerImpl.java

@@ -5,7 +5,6 @@ import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.android.controller.DbControllerImpl;
 import org.briarproject.briar.android.controller.handler.ResultExceptionHandler;
@@ -20,7 +19,6 @@ import java.util.logging.Logger;
 import javax.inject.Inject;
 
 import static java.util.logging.Level.WARNING;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.DISCONNECTED;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 class GroupMemberListControllerImpl extends DbControllerImpl
@@ -52,11 +50,10 @@ class GroupMemberListControllerImpl extends DbControllerImpl
 						privateGroupManager.getMembers(groupId);
 				for (GroupMember m : members) {
 					ContactId c = m.getContactId();
-					ConnectionStatus status = DISCONNECTED;
+					boolean online = false;
-					if (c != null) {
+					if (c != null)
-						status = connectionRegistry.getConnectionStatus(c);
+						online = connectionRegistry.isConnected(c);
-					}
+					items.add(new MemberListItem(m, online));
-					items.add(new MemberListItem(m, status));
 				}
 				handler.onResult(items);
 			} catch (DbException e) {

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/MemberListAdapter.java

@@ -45,7 +45,7 @@ class MemberListAdapter extends
 
 	@Override
 	public boolean areContentsTheSame(MemberListItem m1, MemberListItem m2) {
-		if (m1.getConnectionStatus() != m2.getConnectionStatus()) return false;
+		if (m1.isOnline() != m2.isOnline()) return false;
 		if (m1.getContactId() != m2.getContactId()) return false;
 		if (m1.getStatus() != m2.getStatus()) return false;
 		return true;

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/MemberListItem.java

@@ -5,7 +5,6 @@ import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.identity.AuthorInfo.Status;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.api.privategroup.GroupMember;
 
 import javax.annotation.Nullable;
@@ -16,11 +15,11 @@ import javax.annotation.concurrent.NotThreadSafe;
 class MemberListItem {
 
 	private final GroupMember groupMember;
-	private ConnectionStatus status;
+	private boolean online;
 
-	MemberListItem(GroupMember groupMember, ConnectionStatus status) {
+	MemberListItem(GroupMember groupMember, boolean online) {
 		this.groupMember = groupMember;
-		this.status = status;
+		this.online = online;
 	}
 
 	Author getMember() {
@@ -44,12 +43,12 @@ class MemberListItem {
 		return groupMember.getContactId();
 	}
 
-	ConnectionStatus getConnectionStatus() {
+	boolean isOnline() {
-		return status;
+		return online;
 	}
 
-	void setConnectionStatus(ConnectionStatus status) {
+	void setOnline(boolean online) {
-		this.status = status;
+		this.online = online;
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/privategroup/memberlist/MemberListItemHolder.java

@@ -5,7 +5,6 @@ import android.widget.ImageView;
 import android.widget.TextView;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.view.AuthorView;
 
@@ -15,8 +14,6 @@ import androidx.recyclerview.widget.RecyclerView;
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static org.briarproject.bramble.api.identity.AuthorInfo.Status.OURSELVES;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.CONNECTED;
-import static org.briarproject.bramble.api.plugin.ConnectionStatus.RECENTLY_CONNECTED;
 import static org.briarproject.briar.android.util.UiUtils.getContactDisplayName;
 
 @UiThread
@@ -41,13 +38,10 @@ class MemberListItemHolder extends RecyclerView.ViewHolder {
 		// online status of visible contacts
 		if (item.getContactId() != null) {
 			bulb.setVisibility(VISIBLE);
-			ConnectionStatus status = item.getConnectionStatus();
+			if (item.isOnline()) {
-			if (status == CONNECTED) {
+				bulb.setImageResource(R.drawable.contact_connected);
-				bulb.setImageResource(R.drawable.ic_connected);
-			} else if (status == RECENTLY_CONNECTED) {
-				bulb.setImageResource(R.drawable.ic_recently_connected);
 			} else {
-				bulb.setImageResource(R.drawable.ic_disconnected);
+				bulb.setImageResource(R.drawable.contact_disconnected);
 			}
 		} else {
 			bulb.setVisibility(GONE);

briar-android/src/main/java/org/briarproject/briar/android/sharing/SharingStatusActivity.java

@@ -14,7 +14,6 @@ import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.plugin.ConnectionRegistry;
-import org.briarproject.bramble.api.plugin.ConnectionStatus;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.event.GroupRemovedEvent;
 import org.briarproject.briar.R;
@@ -105,7 +104,7 @@ abstract class SharingStatusActivity extends BriarActivity
 				supportFinishAfterTransition();
 			}
 		}
-		// TODO ConnectionStatusChangedEvent
+		// TODO ContactConnectedEvent and ContactDisconnectedEvent
 	}
 
 	@Override
@@ -135,9 +134,8 @@ abstract class SharingStatusActivity extends BriarActivity
 			try {
 				List<ContactItem> contactItems = new ArrayList<>();
 				for (Contact c : getSharedWith()) {
-					ConnectionStatus status =
+					boolean online = connectionRegistry.isConnected(c.getId());
-							connectionRegistry.getConnectionStatus(c.getId());
+					ContactItem item = new ContactItem(c, online);
-					ContactItem item = new ContactItem(c, status);
 					contactItems.add(item);
 				}
 				displaySharedWith(contactItems);

briar-android/src/main/java/org/briarproject/briar/android/util/UiUtils.java

@@ -238,6 +238,10 @@ public class UiUtils {
 		return "avatar" + c.getInt();
 	}
 
+	public static String getBulbTransitionName(ContactId c) {
+		return "bulb" + c.getInt();
+	}
+
 	public static OnClickListener getGoToSettingsListener(Context context) {
 		return (dialog, which) -> {
 			Intent i = new Intent();
@@ -377,7 +381,7 @@ public class UiUtils {
 	/**
 	 * Same as {@link #observeOnce(LiveData, LifecycleOwner, Observer)},
 	 * but without a {@link LifecycleOwner}.
-	 * <p>
+	 *
 	 * Warning: Do NOT call from objects that have a lifecycle.
 	 */
 	@UiThread
@@ -397,4 +401,5 @@ public class UiUtils {
 		return ctx.getResources().getConfiguration().getLayoutDirection() ==
 				LAYOUT_DIRECTION_RTL;
 	}
+
 }

briar-android/src/main/java/org/briarproject/briar/android/viewmodel/ViewModelModule.java

@@ -4,6 +4,7 @@ import org.briarproject.briar.android.contact.add.remote.AddContactViewModel;
 import org.briarproject.briar.android.contact.add.remote.PendingContactListViewModel;
 import org.briarproject.briar.android.conversation.ConversationViewModel;
 import org.briarproject.briar.android.conversation.ImageViewModel;
+import org.briarproject.briar.android.login.StartupViewModel;
 
 import javax.inject.Singleton;
 
@@ -16,6 +17,11 @@ import dagger.multibindings.IntoMap;
 @Module
 public abstract class ViewModelModule {
 
+	@Binds
+	@IntoMap
+	@ViewModelKey(StartupViewModel.class)
+	abstract ViewModel bindStartupViewModel(StartupViewModel startupViewModel);
+
 	@Binds
 	@IntoMap
 	@ViewModelKey(ConversationViewModel.class)

briar-android/src/main/java/org/briarproject/briar/android/widget/LinkDialogFragment.java

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.widget;
 
 
-import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.net.Uri;
@@ -11,7 +10,6 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.TextView;
-import android.widget.Toast;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
@@ -24,7 +22,6 @@ import androidx.fragment.app.DialogFragment;
 
 import static android.content.Intent.ACTION_VIEW;
 import static android.content.pm.PackageManager.MATCH_DEFAULT_ONLY;
-import static android.widget.Toast.LENGTH_SHORT;
 import static java.util.Objects.requireNonNull;
 
 @MethodsNotNullByDefault
@@ -67,23 +64,18 @@ public class LinkDialogFragment extends DialogFragment {
 		urlView.setText(url);
 
 		// prepare normal intent or intent chooser
-		Context ctx = requireContext();
 		Intent i = new Intent(ACTION_VIEW, Uri.parse(url));
-		PackageManager packageManager = ctx.getPackageManager();
+		PackageManager packageManager =
-		List activities =
+				requireNonNull(getContext()).getPackageManager();
-				packageManager.queryIntentActivities(i, MATCH_DEFAULT_ONLY);
+		List activities = packageManager.queryIntentActivities(i,
+				MATCH_DEFAULT_ONLY);
 		boolean choice = activities.size() > 1;
 		Intent intent = choice ? Intent.createChooser(i,
 				getString(R.string.link_warning_open_link)) : i;
 
 		Button openButton = v.findViewById(R.id.openButton);
 		openButton.setOnClickListener(v1 -> {
-			if (intent.resolveActivity(packageManager) != null) {
+			startActivity(intent);
-				startActivity(intent);
-			} else {
-				Toast.makeText(ctx, R.string.error_start_activity, LENGTH_SHORT)
-						.show();
-			}
 			getDialog().dismiss();
 		});
 

briar-android/src/main/res/drawable-night/contact_connected.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+        android:width="24dp"
+        android:height="24dp"
+        android:viewportHeight="24"
+        android:viewportWidth="24">
+
+	<path
+		android:fillColor="#abffffff"
+		android:pathData="M12,2 C6.48,2,2,6.48,2,12 S6.48,22,12,22 S22,17.52,22,12 S17.52,2,12,2 Z M12,20
+C7.58,20,4,16.42,4,12 S7.58,4,12,4 S20,7.58,20,12 S16.42,20,12,20 Z"/>
+
+	<path
+		android:fillColor="#95d220"
+		android:pathData="M10.8972,19.9503 C6.5514,19.3493,3.43091,15.2154,4.0625,10.896
+C4.55452,7.53099,7.09451,4.8236,10.394,4.14714
+C14.2569,3.35517,18.1698,5.54347,19.5236,9.25295
+C20.0698,10.7495,20.1616,12.4612,19.777,13.9758
+C19.5457,14.8864,18.8106,16.3388,18.2072,17.0771
+C16.4904,19.1779,13.581,20.3215,10.8973,19.9503 Z"
+		android:strokeLineCap="round"
+		android:strokeLineJoin="round"
+		android:strokeWidth="0.76779664"/>
+</vector>