Poll Tor plugin infrequently once our HS is reachable.

Use colours from style guide

See merge request briar/briar!1257

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

@@ -12,7 +12,6 @@ import android.content.IntentFilter;
 import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.PluginException;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
@@ -82,10 +81,10 @@ class AndroidBluetoothPlugin extends BluetoothPlugin<BluetoothServerSocket> {
 			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
 			SecureRandom secureRandom, ScheduledExecutorService scheduler,
 			AndroidExecutor androidExecutor, Context appContext, Clock clock,
-			Backoff backoff, PluginCallback callback, int maxLatency,
+			PluginCallback callback, int maxLatency, int maxIdleTime,
-			int maxIdleTime) {
+			int pollingInterval) {
 		super(connectionLimiter, timeoutMonitor, ioExecutor, secureRandom,
-				backoff, callback, maxLatency, maxIdleTime);
+				callback, maxLatency, maxIdleTime, pollingInterval);
 		this.scheduler = scheduler;
 		this.androidExecutor = androidExecutor;
 		this.appContext = appContext;

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

@@ -5,8 +5,6 @@ import android.content.Context;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
@@ -20,17 +18,17 @@ import java.util.concurrent.ScheduledExecutorService;
 
 import javax.annotation.concurrent.Immutable;
 
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
 
 @Immutable
 @NotNullByDefault
 public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 
-	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_LATENCY = (int) SECONDS.toMillis(30);
-	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = (int) SECONDS.toMillis(30);
-	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int POLLING_INTERVAL = (int) MINUTES.toMillis(2);
-	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
-	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
 	private final ScheduledExecutorService scheduler;
@@ -40,13 +38,12 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 	private final EventBus eventBus;
 	private final Clock clock;
 	private final TimeoutMonitor timeoutMonitor;
-	private final BackoffFactory backoffFactory;
 
 	public AndroidBluetoothPluginFactory(Executor ioExecutor,
 			ScheduledExecutorService scheduler,
 			AndroidExecutor androidExecutor, Context appContext,
 			SecureRandom secureRandom, EventBus eventBus, Clock clock,
-			TimeoutMonitor timeoutMonitor, BackoffFactory backoffFactory) {
+			TimeoutMonitor timeoutMonitor) {
 		this.ioExecutor = ioExecutor;
 		this.scheduler = scheduler;
 		this.androidExecutor = androidExecutor;
@@ -55,7 +52,6 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 		this.eventBus = eventBus;
 		this.clock = clock;
 		this.timeoutMonitor = timeoutMonitor;
-		this.backoffFactory = backoffFactory;
 	}
 
 	@Override
@@ -72,12 +68,10 @@ public class AndroidBluetoothPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(PluginCallback callback) {
 		BluetoothConnectionLimiter connectionLimiter =
 				new BluetoothConnectionLimiterImpl(eventBus);
-		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
-				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		AndroidBluetoothPlugin plugin = new AndroidBluetoothPlugin(
 				connectionLimiter, timeoutMonitor, ioExecutor, secureRandom,
-				scheduler, androidExecutor, appContext, clock, backoff,
+				scheduler, androidExecutor, appContext, clock, callback,
-				callback, MAX_LATENCY, MAX_IDLE_TIME);
+				MAX_LATENCY, MAX_IDLE_TIME, POLLING_INTERVAL);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

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

@@ -15,7 +15,6 @@ import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.settings.Settings;
 
@@ -42,6 +41,7 @@ import static java.util.Collections.list;
 import static java.util.Collections.singletonList;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.api.plugin.LanTcpConstants.DEFAULT_PREF_PLUGIN_ENABLE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.ACTIVE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
 import static org.briarproject.bramble.util.IoUtils.tryToClose;
@@ -61,9 +61,9 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 	private volatile SocketFactory socketFactory;
 
 	AndroidLanTcpPlugin(Executor ioExecutor, Context appContext,
-			Backoff backoff, PluginCallback callback, int maxLatency,
+			PluginCallback callback, int maxLatency, int maxIdleTime,
-			int maxIdleTime, int connectionTimeout) {
+			int pollingInterval, int connectionTimeout) {
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
+		super(ioExecutor, callback, maxLatency, maxIdleTime, pollingInterval,
 				connectionTimeout);
 		// Don't execute more than one connection status check at a time
 		connectionStatusExecutor =
@@ -82,7 +82,8 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 		if (used.getAndSet(true)) throw new IllegalStateException();
 		initialisePortProperty();
 		Settings settings = callback.getSettings();
-		state.setStarted(settings.getBoolean(PREF_PLUGIN_ENABLE, false));
+		state.setStarted(settings.getBoolean(PREF_PLUGIN_ENABLE,
+				DEFAULT_PREF_PLUGIN_ENABLE));
 		updateConnectionStatus();
 	}
 

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

@@ -4,8 +4,6 @@ import android.content.Context;
 
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
@@ -15,29 +13,27 @@ import java.util.concurrent.Executor;
 
 import javax.annotation.concurrent.Immutable;
 
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 
 @Immutable
 @NotNullByDefault
 public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 
-	private static final int MAX_LATENCY = 30_000; // 30 seconds
+	private static final int MAX_LATENCY = (int) SECONDS.toMillis(30);
-	private static final int MAX_IDLE_TIME = 30_000; // 30 seconds
+	private static final int MAX_IDLE_TIME = (int) SECONDS.toMillis(30);
-	private static final int CONNECTION_TIMEOUT = 3_000; // 3 seconds
+	private static final int POLLING_INTERVAL = (int) MINUTES.toMillis(1);
-	private static final int MIN_POLLING_INTERVAL = 60_000; // 1 minute
+	private static final int CONNECTION_TIMEOUT = (int) SECONDS.toMillis(3);
-	private static final int MAX_POLLING_INTERVAL = 600_000; // 10 mins
-	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
 	private final EventBus eventBus;
-	private final BackoffFactory backoffFactory;
 	private final Context appContext;
 
 	public AndroidLanTcpPluginFactory(Executor ioExecutor, EventBus eventBus,
-			BackoffFactory backoffFactory, Context appContext) {
+			Context appContext) {
 		this.ioExecutor = ioExecutor;
 		this.eventBus = eventBus;
-		this.backoffFactory = backoffFactory;
 		this.appContext = appContext;
 	}
 
@@ -53,11 +49,9 @@ public class AndroidLanTcpPluginFactory implements DuplexPluginFactory {
 
 	@Override
 	public DuplexPlugin createPlugin(PluginCallback callback) {
-		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, callback, MAX_LATENCY, MAX_IDLE_TIME,
-				CONNECTION_TIMEOUT);
+				POLLING_INTERVAL, CONNECTION_TIMEOUT);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

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

@@ -10,7 +10,6 @@ import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
@@ -41,13 +40,15 @@ class AndroidTorPlugin extends TorPlugin {
 			LocationUtils locationUtils, SocketFactory torSocketFactory,
 			Clock clock, ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager, Backoff backoff,
+			BatteryManager batteryManager,
 			TorRendezvousCrypto torRendezvousCrypto,
 			PluginCallback callback, String architecture, int maxLatency,
-			int maxIdleTime) {
+			int maxIdleTime, int initialPollingInterval,
+			int stablePollingInterval) {
 		super(ioExecutor, networkManager, locationUtils, torSocketFactory,
 				clock, resourceProvider, circumventionProvider, batteryManager,
-				backoff, torRendezvousCrypto, callback, architecture, maxLatency, maxIdleTime,
+				torRendezvousCrypto, callback, architecture, maxLatency,
+				maxIdleTime, initialPollingInterval, stablePollingInterval,
 				appContext.getDir("tor", MODE_PRIVATE));
 		this.appContext = appContext;
 		PowerManager pm = (PowerManager)

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

@@ -6,8 +6,6 @@ import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TorConstants;
 import org.briarproject.bramble.api.plugin.TransportId;
@@ -25,18 +23,33 @@ import java.util.logging.Logger;
 import javax.annotation.concurrent.Immutable;
 import javax.net.SocketFactory;
 
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static java.util.logging.Logger.getLogger;
+
 @Immutable
 @NotNullByDefault
 public class AndroidTorPluginFactory implements DuplexPluginFactory {
 
 	private static final Logger LOG =
-			Logger.getLogger(AndroidTorPluginFactory.class.getName());
+			getLogger(AndroidTorPluginFactory.class.getName());
 
-	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_LATENCY = (int) SECONDS.toMillis(30);
-	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = (int) SECONDS.toMillis(30);
-	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+
-	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
+	/**
-	private static final double BACKOFF_BASE = 1.2;
+	 * How often to poll before our hidden service becomes reachable.
+	 */
+	private static final int INITIAL_POLLING_INTERVAL =
+			(int) MINUTES.toMillis(1);
+
+	/**
+	 * How often to poll when our hidden service is reachable. Our contacts
+	 * will poll when they come online, so our polling is just a fallback in
+	 * case of repeated connection failures.
+	 */
+	private static final int STABLE_POLLING_INTERVAL =
+			(int) MINUTES.toMillis(15);
 
 	private final Executor ioExecutor;
 	private final ScheduledExecutorService scheduler;
@@ -45,7 +58,6 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 	private final LocationUtils locationUtils;
 	private final EventBus eventBus;
 	private final SocketFactory torSocketFactory;
-	private final BackoffFactory backoffFactory;
 	private final ResourceProvider resourceProvider;
 	private final CircumventionProvider circumventionProvider;
 	private final BatteryManager batteryManager;
@@ -55,7 +67,7 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 			ScheduledExecutorService scheduler, Context appContext,
 			NetworkManager networkManager, LocationUtils locationUtils,
 			EventBus eventBus, SocketFactory torSocketFactory,
-			BackoffFactory backoffFactory, ResourceProvider resourceProvider,
+			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager, Clock clock) {
 		this.ioExecutor = ioExecutor;
@@ -65,7 +77,6 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 		this.locationUtils = locationUtils;
 		this.eventBus = eventBus;
 		this.torSocketFactory = torSocketFactory;
-		this.backoffFactory = backoffFactory;
 		this.resourceProvider = resourceProvider;
 		this.circumventionProvider = circumventionProvider;
 		this.batteryManager = batteryManager;
@@ -109,14 +120,13 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 		// Use position-independent executable
 		architecture += "_pie";
 
-		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
-				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		TorRendezvousCrypto torRendezvousCrypto = new TorRendezvousCryptoImpl();
 		AndroidTorPlugin plugin = new AndroidTorPlugin(ioExecutor, scheduler,
 				appContext, networkManager, locationUtils, torSocketFactory,
 				clock, resourceProvider, circumventionProvider, batteryManager,
-				backoff, torRendezvousCrypto, callback, architecture,
+				torRendezvousCrypto, callback, architecture, MAX_LATENCY,
-				MAX_LATENCY, MAX_IDLE_TIME);
+				MAX_IDLE_TIME, INITIAL_POLLING_INTERVAL,
+				STABLE_POLLING_INTERVAL);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

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

@@ -1,22 +0,0 @@
-package org.briarproject.bramble.api.plugin;
-
-/**
- * Calculates polling intervals for transport plugins that use backoff.
- */
-public interface Backoff {
-
-	/**
-	 * Returns the current polling interval.
-	 */
-	int getPollingInterval();
-
-	/**
-	 * Increments the backoff counter.
-	 */
-	void increment();
-
-	/**
-	 * Resets the backoff counter.
-	 */
-	void reset();
-}

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

@@ -1,7 +0,0 @@
-package org.briarproject.bramble.api.plugin;
-
-public interface BackoffFactory {
-
-	Backoff createBackoff(int minInterval, int maxInterval,
-			double base);
-}

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

@@ -6,6 +6,10 @@ public interface BluetoothConstants {
 
 	int UUID_BYTES = 16;
 
+	// Transport properties
 	String PROP_ADDRESS = "address";
 	String PROP_UUID = "uuid";
+
+	// Default value for PREF_PLUGIN_ENABLE
+	boolean DEFAULT_PREF_PLUGIN_ENABLE = false;
 }

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

@@ -12,4 +12,7 @@ public interface LanTcpConstants {
 	// Local settings (not shared with contacts)
 	String PREF_LAN_IP_PORTS = "ipPorts";
 	String PREF_IPV6 = "ipv6";
+
+	// Default value for PREF_PLUGIN_ENABLE
+	boolean DEFAULT_PREF_PLUGIN_ENABLE = true;
 }

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

@@ -1,9 +1,12 @@
 package org.briarproject.bramble.api.plugin;
 
+import static java.util.concurrent.TimeUnit.DAYS;
+
 public interface TorConstants {
 
 	TransportId ID = new TransportId("org.briarproject.bramble.tor");
 
+	// Transport properties
 	String PROP_ONION_V2 = "onion";
 	String PROP_ONION_V3 = "onion3";
 
@@ -13,17 +16,33 @@ public interface TorConstants {
 	int CONNECT_TO_PROXY_TIMEOUT = 5000; // Milliseconds
 	int EXTRA_SOCKET_TIMEOUT = 30000; // Milliseconds
 
+	// Local settings (not shared with contacts)
 	String PREF_TOR_NETWORK = "network2";
 	String PREF_TOR_PORT = "port";
 	String PREF_TOR_MOBILE = "useMobileData";
 	String PREF_TOR_ONLY_WHEN_CHARGING = "onlyWhenCharging";
+	String HS_PRIVATE_KEY_V2 = "onionPrivKey";
+	String HS_PRIVATE_KEY_V3 = "onionPrivKey3";
+	String HS_V3_CREATED = "onionPrivKey3Created";
 
+	/**
+	 * How long to publish a v3 hidden service before retiring the v2 service.
+	 */
+	long V3_MIGRATION_PERIOD_MS = DAYS.toMillis(180);
+
+	// Values for PREF_TOR_NETWORK
 	int PREF_TOR_NETWORK_AUTOMATIC = 0;
 	int PREF_TOR_NETWORK_WITHOUT_BRIDGES = 1;
 	int PREF_TOR_NETWORK_WITH_BRIDGES = 2;
 	// TODO: Remove when settings migration code is removed
 	int PREF_TOR_NETWORK_NEVER = 3;
 
+	// Default values for local settings
+	boolean DEFAULT_PREF_PLUGIN_ENABLE = true;
+	int DEFAULT_PREF_TOR_NETWORK = PREF_TOR_NETWORK_AUTOMATIC;
+	boolean DEFAULT_PREF_TOR_MOBILE = true;
+	boolean DEFAULT_PREF_TOR_ONLY_WHEN_CHARGING = false;
+
 	/**
 	 * Reason flag returned by {@link Plugin#getReasonsDisabled()}.
 	 */

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

@@ -4,4 +4,7 @@ public interface WanTcpConstants {
 
 	TransportId ID = new TransportId("org.briarproject.bramble.wan");
 
+	// Default value for PREF_PLUGIN_ENABLE
+	boolean DEFAULT_PREF_PLUGIN_ENABLE = false;
 }
+

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

@@ -1,18 +0,0 @@
-package org.briarproject.bramble.plugin;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
-
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
-class BackoffFactoryImpl implements BackoffFactory {
-
-	@Override
-	public Backoff createBackoff(int minInterval, int maxInterval,
-			double base) {
-		return new BackoffImpl(minInterval, maxInterval, base);
-	}
-}

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

@@ -1,42 +0,0 @@
-package org.briarproject.bramble.plugin;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-
-import java.util.concurrent.atomic.AtomicInteger;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-@ThreadSafe
-@NotNullByDefault
-class BackoffImpl implements Backoff {
-
-	private final int minInterval, maxInterval;
-	private final double base;
-	private final AtomicInteger backoff;
-
-	BackoffImpl(int minInterval, int maxInterval, double base) {
-		this.minInterval = minInterval;
-		this.maxInterval = maxInterval;
-		this.base = base;
-		backoff = new AtomicInteger(0);
-	}
-
-	@Override
-	public int getPollingInterval() {
-		double multiplier = Math.pow(base, backoff.get());
-		// Large or infinite values will be rounded to Integer.MAX_VALUE
-		int interval = (int) (minInterval * multiplier);
-		return Math.min(interval, maxInterval);
-	}
-
-	@Override
-	public void increment() {
-		backoff.incrementAndGet();
-	}
-
-	@Override
-	public void reset() {
-		backoff.set(0);
-	}
-}

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

@@ -2,7 +2,6 @@ package org.briarproject.bramble.plugin;
 
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginConfig;
 import org.briarproject.bramble.api.plugin.PluginManager;
 
@@ -22,11 +21,6 @@ public class PluginModule {
 		Poller poller;
 	}
 
-	@Provides
-	BackoffFactory provideBackoffFactory() {
-		return new BackoffFactoryImpl();
-	}
-
 	@Provides
 	@Singleton
 	PluginManager providePluginManager(LifecycleManager lifecycleManager,

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

@@ -19,7 +19,6 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
 import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
 import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
@@ -96,16 +95,10 @@ class PollerImpl implements Poller, EventListener {
 			connectToContact(c.getContactId());
 		} else if (e instanceof ConnectionClosedEvent) {
 			ConnectionClosedEvent c = (ConnectionClosedEvent) e;
-			// Reschedule polling, the polling interval may have decreased
-			reschedule(c.getTransportId());
 			// If an outgoing connection failed, try to reconnect
 			if (!c.isIncoming() && c.isException()) {
 				connectToContact(c.getContactId(), c.getTransportId());
 			}
-		} else if (e instanceof ConnectionOpenedEvent) {
-			ConnectionOpenedEvent c = (ConnectionOpenedEvent) e;
-			// Reschedule polling, the polling interval may have decreased
-			reschedule(c.getTransportId());
 		} else if (e instanceof TransportActiveEvent) {
 			TransportActiveEvent t = (TransportActiveEvent) e;
 			// Poll the newly activated transport
@@ -164,12 +157,6 @@ class PollerImpl implements Poller, EventListener {
 		});
 	}
 
-	private void reschedule(TransportId t) {
-		Plugin p = pluginManager.getPlugin(t);
-		if (p != null && p.shouldPoll())
-			schedule(p, p.getPollingInterval(), false);
-	}
-
 	private void pollNow(TransportId t) {
 		Plugin p = pluginManager.getPlugin(t);
 		// Randomise next polling interval

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

@@ -14,7 +14,6 @@ import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.PluginException;
@@ -46,6 +45,7 @@ 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.keyagreement.KeyAgreementConstants.TRANSPORT_ID_BLUETOOTH;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.DEFAULT_PREF_PLUGIN_ENABLE;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_UUID;
@@ -72,9 +72,8 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	private final Executor ioExecutor;
 	private final SecureRandom secureRandom;
-	private final Backoff backoff;
 	private final PluginCallback callback;
-	private final int maxLatency, maxIdleTime;
+	private final int maxLatency, maxIdleTime, pollingInterval;
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	protected final PluginState state = new PluginState();
@@ -115,16 +114,16 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	BluetoothPlugin(BluetoothConnectionLimiter connectionLimiter,
 			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
-			SecureRandom secureRandom, Backoff backoff,
+			SecureRandom secureRandom, PluginCallback callback, int maxLatency, int maxIdleTime,
-			PluginCallback callback, int maxLatency, int maxIdleTime) {
+			int pollingInterval) {
 		this.connectionLimiter = connectionLimiter;
 		this.timeoutMonitor = timeoutMonitor;
 		this.ioExecutor = ioExecutor;
 		this.secureRandom = secureRandom;
-		this.backoff = backoff;
 		this.callback = callback;
 		this.maxLatency = maxLatency;
 		this.maxIdleTime = maxIdleTime;
+		this.pollingInterval = pollingInterval;
 	}
 
 	void onAdapterEnabled() {
@@ -164,7 +163,8 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 	public void start() throws PluginException {
 		if (used.getAndSet(true)) throw new IllegalStateException();
 		Settings settings = callback.getSettings();
-		boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE, false);
+		boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE,
+				DEFAULT_PREF_PLUGIN_ENABLE);
 		state.setStarted(enabledByUser);
 		try {
 			initialiseAdapter();
@@ -194,7 +194,6 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 				tryToClose(ss);
 				return;
 			}
-			backoff.reset();
 			acceptContactConnections(ss);
 		});
 	}
@@ -237,7 +236,6 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 			}
 			LOG.info("Connection received");
 			connectionLimiter.connectionOpened(conn);
-			backoff.reset();
 			callback.handleConnection(conn);
 		}
 	}
@@ -266,14 +264,13 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	@Override
 	public int getPollingInterval() {
-		return backoff.getPollingInterval();
+		return pollingInterval;
 	}
 
 	@Override
 	public void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties) {
 		if (getState() != ACTIVE) return;
-		backoff.increment();
 		for (Pair<TransportProperties, ConnectionHandler> p : properties) {
 			connect(p.getFirst(), p.getSecond());
 		}
@@ -286,10 +283,7 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 		if (isNullOrEmpty(uuid)) return;
 		ioExecutor.execute(() -> {
 			DuplexTransportConnection d = createConnection(p);
-			if (d != null) {
+			if (d != null) h.handleConnection(d);
-				backoff.reset();
-				h.handleConnection(d);
-			}
 		});
 	}
 
@@ -432,7 +426,8 @@ abstract class BluetoothPlugin<SS> implements DuplexPlugin, EventListener {
 
 	@IoExecutor
 	private void onSettingsUpdated(Settings settings) {
-		boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE, false);
+		boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE,
+				DEFAULT_PREF_PLUGIN_ENABLE);
 		SS ss = state.setEnabledByUser(enabledByUser);
 		State s = getState();
 		if (ss != null) {

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

@@ -5,7 +5,6 @@ import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
@@ -38,6 +37,7 @@ 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.keyagreement.KeyAgreementConstants.TRANSPORT_ID_LAN;
+import static org.briarproject.bramble.api.plugin.LanTcpConstants.DEFAULT_PREF_PLUGIN_ENABLE;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.PREF_IPV6;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.PREF_LAN_IP_PORTS;
@@ -87,9 +87,9 @@ class LanTcpPlugin extends TcpPlugin {
 		}
 	}
 
-	LanTcpPlugin(Executor ioExecutor, Backoff backoff, PluginCallback callback,
+	LanTcpPlugin(Executor ioExecutor, PluginCallback callback, int maxLatency,
-			int maxLatency, int maxIdleTime, int connectionTimeout) {
+			int maxIdleTime, int pollingInterval, int connectionTimeout) {
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
+		super(ioExecutor, callback, maxLatency, maxIdleTime, pollingInterval,
 				connectionTimeout);
 	}
 
@@ -103,7 +103,8 @@ class LanTcpPlugin extends TcpPlugin {
 		if (used.getAndSet(true)) throw new IllegalStateException();
 		initialisePortProperty();
 		Settings settings = callback.getSettings();
-		state.setStarted(settings.getBoolean(PREF_PLUGIN_ENABLE, false));
+		state.setStarted(settings.getBoolean(PREF_PLUGIN_ENABLE,
+				DEFAULT_PREF_PLUGIN_ENABLE));
 		bind();
 	}
 
@@ -116,6 +117,11 @@ class LanTcpPlugin extends TcpPlugin {
 		}
 	}
 
+	@Override
+	protected boolean isEnabledByDefault() {
+		return DEFAULT_PREF_PLUGIN_ENABLE;
+	}
+
 	@Override
 	protected List<InetSocketAddress> getLocalSocketAddresses(boolean ipv4) {
 		TransportProperties p = callback.getLocalProperties();

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

@@ -2,8 +2,6 @@ package org.briarproject.bramble.plugin.tcp;
 
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
@@ -13,28 +11,25 @@ import java.util.concurrent.Executor;
 
 import javax.annotation.concurrent.Immutable;
 
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
 
 @Immutable
 @NotNullByDefault
 public class LanTcpPluginFactory implements DuplexPluginFactory {
 
-	private static final int MAX_LATENCY = 30_000; // 30 seconds
+	private static final int MAX_LATENCY = (int) SECONDS.toMillis(30);
-	private static final int MAX_IDLE_TIME = 30_000; // 30 seconds
+	private static final int MAX_IDLE_TIME = (int) SECONDS.toMillis(30);
-	private static final int CONNECTION_TIMEOUT = 3_000; // 3 seconds
+	private static final int POLLING_INTERVAL = (int) MINUTES.toMillis(1);
-	private static final int MIN_POLLING_INTERVAL = 60_000; // 1 minute
+	private static final int CONNECTION_TIMEOUT = (int) SECONDS.toMillis(3);
-	private static final int MAX_POLLING_INTERVAL = 600_000; // 10 mins
-	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
 	private final EventBus eventBus;
-	private final BackoffFactory backoffFactory;
 
-	public LanTcpPluginFactory(Executor ioExecutor, EventBus eventBus,
+	public LanTcpPluginFactory(Executor ioExecutor, EventBus eventBus) {
-			BackoffFactory backoffFactory) {
 		this.ioExecutor = ioExecutor;
 		this.eventBus = eventBus;
-		this.backoffFactory = backoffFactory;
 	}
 
 	@Override
@@ -49,10 +44,9 @@ public class LanTcpPluginFactory implements DuplexPluginFactory {
 
 	@Override
 	public DuplexPlugin createPlugin(PluginCallback callback) {
-		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+		LanTcpPlugin plugin = new LanTcpPlugin(ioExecutor, callback,
-				MAX_POLLING_INTERVAL, BACKOFF_BASE);
+				MAX_LATENCY, MAX_IDLE_TIME, POLLING_INTERVAL,
-		LanTcpPlugin plugin =  new LanTcpPlugin(ioExecutor, backoff, callback, MAX_LATENCY,
+				CONNECTION_TIMEOUT);
-				MAX_IDLE_TIME, CONNECTION_TIMEOUT);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

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

@@ -10,7 +10,6 @@ import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
@@ -67,9 +66,8 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 			Pattern.compile("^\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}$");
 
 	protected final Executor ioExecutor, bindExecutor;
-	protected final Backoff backoff;
 	protected final PluginCallback callback;
-	protected final int maxLatency, maxIdleTime;
+	protected final int maxLatency, maxIdleTime, pollingInterval;
 	protected final int connectionTimeout, socketTimeout;
 	protected final AtomicBoolean used = new AtomicBoolean(false);
 	protected final PluginState state = new PluginState();
@@ -102,13 +100,18 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 	protected abstract boolean isConnectable(InterfaceAddress local,
 			InetSocketAddress remote);
 
-	TcpPlugin(Executor ioExecutor, Backoff backoff, PluginCallback callback,
+	/**
-			int maxLatency, int maxIdleTime, int connectionTimeout) {
+	 * Returns true if the plugin is enabled by default.
+	 */
+	protected abstract boolean isEnabledByDefault();
+
+	TcpPlugin(Executor ioExecutor, PluginCallback callback, int maxLatency,
+			int maxIdleTime, int pollingInterval, int connectionTimeout) {
 		this.ioExecutor = ioExecutor;
-		this.backoff = backoff;
 		this.callback = callback;
 		this.maxLatency = maxLatency;
 		this.maxIdleTime = maxIdleTime;
+		this.pollingInterval = pollingInterval;
 		this.connectionTimeout = connectionTimeout;
 		if (maxIdleTime > Integer.MAX_VALUE / 2)
 			socketTimeout = Integer.MAX_VALUE;
@@ -131,7 +134,8 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 	public void start() {
 		if (used.getAndSet(true)) throw new IllegalStateException();
 		Settings settings = callback.getSettings();
-		state.setStarted(settings.getBoolean(PREF_PLUGIN_ENABLE, false));
+		state.setStarted(
+				settings.getBoolean(PREF_PLUGIN_ENABLE, isEnabledByDefault()));
 		bind();
 	}
 
@@ -165,7 +169,6 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 			tryToClose(ss, LOG, WARNING);
 			return;
 		}
-		backoff.reset();
 		InetSocketAddress local =
 				(InetSocketAddress) ss.getLocalSocketAddress();
 		setLocalSocketAddress(local, ipv4);
@@ -198,7 +201,6 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 				LOG.info("Connection from " +
 						scrubSocketAddress(s.getRemoteSocketAddress()));
 			}
-			backoff.reset();
 			callback.handleConnection(new TcpTransportConnection(this, s));
 		}
 	}
@@ -225,14 +227,13 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 
 	@Override
 	public int getPollingInterval() {
-		return backoff.getPollingInterval();
+		return pollingInterval;
 	}
 
 	@Override
 	public void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties) {
 		if (getState() != ACTIVE) return;
-		backoff.increment();
 		for (Pair<TransportProperties, ConnectionHandler> p : properties) {
 			connect(p.getFirst(), p.getSecond());
 		}
@@ -241,10 +242,7 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 	private void connect(TransportProperties p, ConnectionHandler h) {
 		ioExecutor.execute(() -> {
 			DuplexTransportConnection d = createConnection(p);
-			if (d != null) {
+			if (d != null) h.handleConnection(d);
-				backoff.reset();
-				h.handleConnection(d);
-			}
 		});
 	}
 
@@ -402,7 +400,8 @@ abstract class TcpPlugin implements DuplexPlugin, EventListener {
 
 	@IoExecutor
 	private void onSettingsUpdated(Settings settings) {
-		boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE, false);
+		boolean enabledByUser =
+				settings.getBoolean(PREF_PLUGIN_ENABLE, isEnabledByDefault());
 		List<ServerSocket> toClose = state.setEnabledByUser(enabledByUser);
 		State s = getState();
 		if (!toClose.isEmpty()) {

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

@@ -2,7 +2,6 @@ package org.briarproject.bramble.plugin.tcp;
 
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
@@ -17,6 +16,7 @@ import java.util.concurrent.Executor;
 
 import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
+import static org.briarproject.bramble.api.plugin.WanTcpConstants.DEFAULT_PREF_PLUGIN_ENABLE;
 import static org.briarproject.bramble.api.plugin.WanTcpConstants.ID;
 
 @MethodsNotNullByDefault
@@ -29,10 +29,10 @@ class WanTcpPlugin extends TcpPlugin {
 
 	private volatile MappingResult mappingResult;
 
-	WanTcpPlugin(Executor ioExecutor, Backoff backoff, PortMapper portMapper,
+	WanTcpPlugin(Executor ioExecutor, PortMapper portMapper,
 			PluginCallback callback, int maxLatency, int maxIdleTime,
-			int connectionTimeout) {
+			int pollingInterval, int connectionTimeout) {
-		super(ioExecutor, backoff, callback, maxLatency, maxIdleTime,
+		super(ioExecutor, callback, maxLatency, maxIdleTime, pollingInterval,
 				connectionTimeout);
 		this.portMapper = portMapper;
 	}
@@ -42,6 +42,11 @@ class WanTcpPlugin extends TcpPlugin {
 		return ID;
 	}
 
+	@Override
+	protected boolean isEnabledByDefault() {
+		return DEFAULT_PREF_PLUGIN_ENABLE;
+	}
+
 	@Override
 	protected List<InetSocketAddress> getLocalSocketAddresses(boolean ipv4) {
 		if (!ipv4) return emptyList();

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

@@ -3,8 +3,6 @@ package org.briarproject.bramble.plugin.tcp;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
@@ -14,29 +12,27 @@ import java.util.concurrent.Executor;
 
 import javax.annotation.concurrent.Immutable;
 
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.briarproject.bramble.api.plugin.WanTcpConstants.ID;
 
 @Immutable
 @NotNullByDefault
 public class WanTcpPluginFactory implements DuplexPluginFactory {
 
-	private static final int MAX_LATENCY = 30_000; // 30 seconds
+	private static final int MAX_LATENCY = (int) SECONDS.toMillis(30);
-	private static final int MAX_IDLE_TIME = 30_000; // 30 seconds
+	private static final int MAX_IDLE_TIME = (int) SECONDS.toMillis(30);
-	private static final int CONNECTION_TIMEOUT = 30_000; // 30 seconds
+	private static final int POLLING_INTERVAL = (int) MINUTES.toMillis(1);
-	private static final int MIN_POLLING_INTERVAL = 60_000; // 1 minute
+	private static final int CONNECTION_TIMEOUT = (int) SECONDS.toMillis(30);
-	private static final int MAX_POLLING_INTERVAL = 600_000; // 10 mins
-	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
 	private final EventBus eventBus;
-	private final BackoffFactory backoffFactory;
 	private final ShutdownManager shutdownManager;
 
 	public WanTcpPluginFactory(Executor ioExecutor, EventBus eventBus,
-			BackoffFactory backoffFactory, ShutdownManager shutdownManager) {
+			ShutdownManager shutdownManager) {
 		this.ioExecutor = ioExecutor;
 		this.eventBus = eventBus;
-		this.backoffFactory = backoffFactory;
 		this.shutdownManager = shutdownManager;
 	}
 
@@ -52,11 +48,9 @@ public class WanTcpPluginFactory implements DuplexPluginFactory {
 
 	@Override
 	public DuplexPlugin createPlugin(PluginCallback callback) {
-		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
+		WanTcpPlugin plugin = new WanTcpPlugin(ioExecutor,
-				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-		WanTcpPlugin plugin = new WanTcpPlugin(ioExecutor, backoff,
 				new PortMapperImpl(shutdownManager), callback, MAX_LATENCY,
-				MAX_IDLE_TIME, CONNECTION_TIMEOUT);
+				MAX_IDLE_TIME, POLLING_INTERVAL, CONNECTION_TIMEOUT);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

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

@@ -17,7 +17,6 @@ import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.ConnectionHandler;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.PluginException;
@@ -46,9 +45,11 @@ import java.net.ServerSocket;
 import java.net.Socket;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Scanner;
+import java.util.Set;
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.logging.Logger;
@@ -75,6 +76,13 @@ import static org.briarproject.bramble.api.plugin.Plugin.State.ENABLING;
 import static org.briarproject.bramble.api.plugin.Plugin.State.INACTIVE;
 import static org.briarproject.bramble.api.plugin.Plugin.State.STARTING_STOPPING;
 import static org.briarproject.bramble.api.plugin.TorConstants.CONTROL_PORT;
+import static org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_PREF_PLUGIN_ENABLE;
+import static org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_PREF_TOR_MOBILE;
+import static org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_PREF_TOR_NETWORK;
+import static org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_PREF_TOR_ONLY_WHEN_CHARGING;
+import static org.briarproject.bramble.api.plugin.TorConstants.HS_PRIVATE_KEY_V2;
+import static org.briarproject.bramble.api.plugin.TorConstants.HS_PRIVATE_KEY_V3;
+import static org.briarproject.bramble.api.plugin.TorConstants.HS_V3_CREATED;
 import static org.briarproject.bramble.api.plugin.TorConstants.ID;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_MOBILE;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK;
@@ -88,6 +96,7 @@ import static org.briarproject.bramble.api.plugin.TorConstants.PROP_ONION_V3;
 import static org.briarproject.bramble.api.plugin.TorConstants.REASON_BATTERY;
 import static org.briarproject.bramble.api.plugin.TorConstants.REASON_COUNTRY_BLOCKED;
 import static org.briarproject.bramble.api.plugin.TorConstants.REASON_MOBILE_DATA;
+import static org.briarproject.bramble.api.plugin.TorConstants.V3_MIGRATION_PERIOD_MS;
 import static org.briarproject.bramble.plugin.tor.TorRendezvousCrypto.SEED_BYTES;
 import static org.briarproject.bramble.util.IoUtils.copyAndClose;
 import static org.briarproject.bramble.util.IoUtils.tryToClose;
@@ -101,28 +110,59 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	private static final Logger LOG = getLogger(TorPlugin.class.getName());
 
+	/**
+	 * Controller events we want to receive.
+	 */
 	private static final String[] EVENTS = {
 			"CIRC", "ORCONN", "HS_DESC", "NOTICE", "WARN", "ERR"
 	};
+
+	/**
+	 * Command-line argument to set our process as Tor's owning controller
+	 * so Tor exits when our process dies.
+	 */
 	private static final String OWNER = "__OwningControllerProcess";
+
+	/**
+	 * How long to wait for the authentication cookie file to be created.
+	 */
 	private static final int COOKIE_TIMEOUT_MS = 3000;
+
+	/**
+	 * How often to check whether the authentication cookie file has been
+	 * created.
+	 */
 	private static final int COOKIE_POLLING_INTERVAL_MS = 200;
+
+	/**
+	 * Regex for matching v2 hidden service names.
+	 */
 	private static final Pattern ONION_V2 = Pattern.compile("[a-z2-7]{16}");
+
+	/**
+	 * Regex for matching v3 hidden service names.
+	 */
 	private static final Pattern ONION_V3 = Pattern.compile("[a-z2-7]{56}");
 
+	/**
+	 * How many copies of our descriptor must be uploaded before we consider
+	 * our hidden service to be reachable and switch to less frequent polling.
+	 */
+	private static final int MIN_DESCRIPTORS_UPLOADED = 5;
+
 	private final Executor ioExecutor, connectionStatusExecutor;
 	private final NetworkManager networkManager;
 	private final LocationUtils locationUtils;
 	private final SocketFactory torSocketFactory;
 	private final Clock clock;
 	private final BatteryManager batteryManager;
-	private final Backoff backoff;
 	private final TorRendezvousCrypto torRendezvousCrypto;
 	private final PluginCallback callback;
 	private final String architecture;
 	private final CircumventionProvider circumventionProvider;
 	private final ResourceProvider resourceProvider;
 	private final int maxLatency, maxIdleTime, socketTimeout;
+	private final int initialPollingInterval, stablePollingInterval;
 	private final File torDirectory, torFile, geoIpFile, obfs4File, configFile;
 	private final File doneFile, cookieFile;
 	private final AtomicBoolean used = new AtomicBoolean(false);
@@ -141,10 +181,11 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			LocationUtils locationUtils, SocketFactory torSocketFactory,
 			Clock clock, ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager, Backoff backoff,
+			BatteryManager batteryManager,
 			TorRendezvousCrypto torRendezvousCrypto,
 			PluginCallback callback, String architecture, int maxLatency,
-			int maxIdleTime, File torDirectory) {
+			int maxIdleTime, int initialPollingInterval,
+			int stablePollingInterval, File torDirectory) {
 		this.ioExecutor = ioExecutor;
 		this.networkManager = networkManager;
 		this.locationUtils = locationUtils;
@@ -153,7 +194,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		this.resourceProvider = resourceProvider;
 		this.circumventionProvider = circumventionProvider;
 		this.batteryManager = batteryManager;
-		this.backoff = backoff;
 		this.torRendezvousCrypto = torRendezvousCrypto;
 		this.callback = callback;
 		this.architecture = architecture;
@@ -162,6 +202,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (maxIdleTime > Integer.MAX_VALUE / 2)
 			socketTimeout = Integer.MAX_VALUE;
 		else socketTimeout = maxIdleTime * 2;
+		this.initialPollingInterval = initialPollingInterval;
+		this.stablePollingInterval = stablePollingInterval;
 		this.torDirectory = torDirectory;
 		torFile = new File(torDirectory, "tor");
 		geoIpFile = new File(torDirectory, "geoip");
@@ -290,9 +332,9 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	// TODO: Remove after a reasonable migration period (added 2020-06-25)
 	private Settings migrateSettings(Settings settings) {
 		int network = settings.getInt(PREF_TOR_NETWORK,
-				PREF_TOR_NETWORK_AUTOMATIC);
+				DEFAULT_PREF_TOR_NETWORK);
 		if (network == PREF_TOR_NETWORK_NEVER) {
-			settings.putInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_AUTOMATIC);
+			settings.putInt(PREF_TOR_NETWORK, DEFAULT_PREF_TOR_NETWORK);
 			settings.putBoolean(PREF_PLUGIN_ENABLE, false);
 			callback.mergeSettings(settings);
 		}
@@ -426,7 +468,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			callback.mergeSettings(s);
 			// Create a hidden service if necessary
 			ioExecutor.execute(() -> publishHiddenService(localPort));
-			backoff.reset();
 			// Accept incoming hidden service connections from Tor
 			acceptContactConnections(ss);
 		});
@@ -434,15 +475,66 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	private void publishHiddenService(String port) {
 		if (!state.isTorRunning()) return;
-		LOG.info("Creating hidden service");
+		// TODO: Remove support for v2 hidden services after a reasonable
-		String privKey = settings.get(HS_PRIVKEY);
+		// migration period (migration started 2020-06-30)
+		String privKey2 = settings.get(HS_PRIVATE_KEY_V2);
+		String privKey3 = settings.get(HS_PRIVATE_KEY_V3);
+		String v3Created = settings.get(HS_V3_CREATED);
+		// Publish a v2 hidden service if we've already created one, and
+		// either we've never published a v3 hidden service or we're still
+		// in the migration period since first publishing it
+		if (!isNullOrEmpty(privKey2)) {
+			long now = clock.currentTimeMillis();
+			long then = v3Created == null ? now : Long.valueOf(v3Created);
+			if (now - then >= V3_MIGRATION_PERIOD_MS) retireV2HiddenService();
+			else publishV2HiddenService(port, privKey2);
+		}
+		publishV3HiddenService(port, privKey3);
+	}
+
+	private void publishV2HiddenService(String port, String privKey) {
+		LOG.info("Creating v2 hidden service");
+		Map<Integer, String> portLines = singletonMap(80, "127.0.0.1:" + port);
+		Map<String, String> response;
+		try {
+			response = controlConnection.addOnion(privKey, portLines);
+		} catch (IOException e) {
+			logException(LOG, WARNING, e);
+			return;
+		}
+		if (!response.containsKey(HS_ADDRESS)) {
+			LOG.warning("Tor did not return a hidden service address");
+			return;
+		}
+		String onion2 = response.get(HS_ADDRESS);
+		if (LOG.isLoggable(INFO)) {
+			LOG.info("V2 hidden service " + scrubOnion(onion2));
+		}
+		// The hostname has already been published and the private key stored
+	}
+
+	private void retireV2HiddenService() {
+		LOG.info("Retiring v2 hidden service");
+		TransportProperties p = new TransportProperties();
+		p.put(PROP_ONION_V2, "");
+		callback.mergeLocalProperties(p);
+		Settings s = new Settings();
+		s.put(HS_PRIVATE_KEY_V2, "");
+		callback.mergeSettings(s);
+	}
+
+	private void publishV3HiddenService(String port, @Nullable String privKey) {
+		LOG.info("Creating v3 hidden service");
 		Map<Integer, String> portLines = singletonMap(80, "127.0.0.1:" + port);
 		Map<String, String> response;
 		try {
 			// Use the control connection to set up the hidden service
-			if (privKey == null)
+			if (privKey == null) {
-				response = controlConnection.addOnion(portLines);
+				response = controlConnection.addOnion("NEW:ED25519-V3",
-			else response = controlConnection.addOnion(privKey, portLines);
+						portLines, null);
+			} else {
+				response = controlConnection.addOnion(privKey, portLines);
+			}
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
 			return;
@@ -456,16 +548,18 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			return;
 		}
 		// Publish the hidden service's onion hostname in transport properties
-		String onion2 = response.get(HS_ADDRESS);
+		String onion3 = response.get(HS_ADDRESS);
-		if (LOG.isLoggable(INFO))
+		if (LOG.isLoggable(INFO)) {
-			LOG.info("Hidden service " + scrubOnion(onion2));
+			LOG.info("V3 hidden service " + scrubOnion(onion3));
+		}
 		TransportProperties p = new TransportProperties();
-		p.put(PROP_ONION_V2, onion2);
+		p.put(PROP_ONION_V3, onion3);
 		callback.mergeLocalProperties(p);
 		if (privKey == null) {
 			// Save the hidden service's private key for next time
 			Settings s = new Settings();
-			s.put(HS_PRIVKEY, response.get(HS_PRIVKEY));
+			s.put(HS_PRIVATE_KEY_V3, response.get(HS_PRIVKEY));
+			s.put(HS_V3_CREATED, String.valueOf(clock.currentTimeMillis()));
 			callback.mergeSettings(s);
 		}
 	}
@@ -483,7 +577,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				return;
 			}
 			LOG.info("Connection received");
-			backoff.reset();
 			callback.handleConnection(new TorTransportConnection(this, s));
 		}
 	}
@@ -545,14 +638,19 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	@Override
 	public int getPollingInterval() {
-		return backoff.getPollingInterval();
+		if (state.isDescriptorPublished()) {
+			LOG.info("Using stable polling interval");
+			return stablePollingInterval;
+		} else {
+			LOG.info("Using initial polling interval");
+			return initialPollingInterval;
+		}
 	}
 
 	@Override
 	public void poll(Collection<Pair<TransportProperties, ConnectionHandler>>
 			properties) {
 		if (getState() != ACTIVE) return;
-		backoff.increment();
 		for (Pair<TransportProperties, ConnectionHandler> p : properties) {
 			connect(p.getFirst(), p.getSecond());
 		}
@@ -561,22 +659,22 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	private void connect(TransportProperties p, ConnectionHandler h) {
 		ioExecutor.execute(() -> {
 			DuplexTransportConnection d = createConnection(p);
-			if (d != null) {
+			if (d != null) h.handleConnection(d);
-				backoff.reset();
-				h.handleConnection(d);
-			}
 		});
 	}
 
 	@Override
 	public DuplexTransportConnection createConnection(TransportProperties p) {
 		if (getState() != ACTIVE) return null;
-		String bestOnion = null;
+		// TODO: Remove support for v2 hidden services after a reasonable
+		// migration period (migration started 2020-06-30)
+		String bestOnion = null, version = null;
 		String onion2 = p.get(PROP_ONION_V2);
 		String onion3 = p.get(PROP_ONION_V3);
 		if (!isNullOrEmpty(onion2)) {
 			if (ONION_V2.matcher(onion2).matches()) {
 				bestOnion = onion2;
+				version = "v2";
 			} else {
 				// Don't scrub the address so we can find the problem
 				if (LOG.isLoggable(INFO))
@@ -586,6 +684,7 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (!isNullOrEmpty(onion3)) {
 			if (ONION_V3.matcher(onion3).matches()) {
 				bestOnion = onion3;
+				version = "v3";
 			} else {
 				// Don't scrub the address so we can find the problem
 				if (LOG.isLoggable(INFO))
@@ -595,17 +694,21 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (bestOnion == null) return null;
 		Socket s = null;
 		try {
-			if (LOG.isLoggable(INFO))
+			if (LOG.isLoggable(INFO)) {
-				LOG.info("Connecting to " + scrubOnion(bestOnion));
+				LOG.info("Connecting to " + version + " "
+						+ scrubOnion(bestOnion));
+			}
 			s = torSocketFactory.createSocket(bestOnion + ".onion", 80);
 			s.setSoTimeout(socketTimeout);
-			if (LOG.isLoggable(INFO))
+			if (LOG.isLoggable(INFO)) {
-				LOG.info("Connected to " + scrubOnion(bestOnion));
+				LOG.info("Connected to " + version + " "
+						+ scrubOnion(bestOnion));
+			}
 			return new TorTransportConnection(this, s);
 		} catch (IOException e) {
 			if (LOG.isLoggable(INFO)) {
-				LOG.info("Could not connect to " + scrubOnion(bestOnion)
+				LOG.info("Could not connect to " + version + " "
-						+ ": " + e.toString());
+						+ scrubOnion(bestOnion) + ": " + e.toString());
 			}
 			tryToClose(s, LOG, WARNING);
 			return null;
@@ -686,10 +789,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	@Override
 	public void circuitStatus(String status, String id, String path) {
-		if (status.equals("BUILT") &&
+		if (status.equals("BUILT") && state.getAndSetCircuitBuilt()) {
-				state.getAndSetCircuitBuilt()) {
 			LOG.info("First circuit built");
-			backoff.reset();
 		}
 	}
 
@@ -699,8 +800,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 
 	@Override
 	public void orConnStatus(String status, String orName) {
-		if (LOG.isLoggable(INFO))
+		if (LOG.isLoggable(INFO)) LOG.info("OR connection " + status);
-			LOG.info("OR connection " + status + " " + orName);
+		state.setOrConnectionStatus(orName, status);
 		if (status.equals("CLOSED") || status.equals("FAILED")) {
 			// Check whether we've lost connectivity
 			updateConnectionStatus(networkManager.getNetworkStatus(),
@@ -721,14 +822,20 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (LOG.isLoggable(INFO)) LOG.info(severity + " " + msg);
 		if (severity.equals("NOTICE") && msg.startsWith("Bootstrapped 100%")) {
 			state.setBootstrapped();
-			backoff.reset();
 		}
 	}
 
 	@Override
 	public void unrecognized(String type, String msg) {
-		if (type.equals("HS_DESC") && msg.startsWith("UPLOADED"))
+		if (type.equals("HS_DESC") && msg.startsWith("UPLOADED")) {
-			LOG.info("Descriptor uploaded");
+			String[] words = msg.split(" ");
+			if (words.length > 1 && ONION_V3.matcher(words[1]).matches()) {
+				LOG.info("V3 descriptor uploaded");
+				state.descriptorUploaded();
+			} else {
+				LOG.info("V2 descriptor uploaded");
+			}
+		}
 	}
 
 	@Override
@@ -774,13 +881,15 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			String country = locationUtils.getCurrentCountry();
 			boolean blocked =
 					circumventionProvider.isTorProbablyBlocked(country);
-			boolean enabledByUser =
+			boolean enabledByUser = settings.getBoolean(PREF_PLUGIN_ENABLE,
-					settings.getBoolean(PREF_PLUGIN_ENABLE, true);
+					DEFAULT_PREF_PLUGIN_ENABLE);
 			int network = settings.getInt(PREF_TOR_NETWORK,
-					PREF_TOR_NETWORK_AUTOMATIC);
+					DEFAULT_PREF_TOR_NETWORK);
-			boolean useMobile = settings.getBoolean(PREF_TOR_MOBILE, true);
+			boolean useMobile = settings.getBoolean(PREF_TOR_MOBILE,
+					DEFAULT_PREF_TOR_MOBILE);
 			boolean onlyWhenCharging =
-					settings.getBoolean(PREF_TOR_ONLY_WHEN_CHARGING, false);
+					settings.getBoolean(PREF_TOR_ONLY_WHEN_CHARGING,
+							DEFAULT_PREF_TOR_ONLY_WHEN_CHARGING);
 			boolean bridgesWork = circumventionProvider.doBridgesWork(country);
 			boolean automatic = network == PREF_TOR_NETWORK_AUTOMATIC;
 
@@ -880,6 +989,12 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		@Nullable
 		private ServerSocket serverSocket = null;
 
+		@GuardedBy("this")
+		private final Set<String> orConnections = new HashSet<>();
+
+		@GuardedBy("this")
+		private int descriptorsUploaded = 0;
+
 		synchronized void setStarted() {
 			started = true;
 			callback.pluginStateChanged(getState());
@@ -913,7 +1028,10 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		synchronized void enableNetwork(boolean enable) {
 			networkInitialised = true;
 			networkEnabled = enable;
-			if (!enable) circuitBuilt = false;
+			if (!enable) {
+				circuitBuilt = false;
+				descriptorsUploaded = 0;
+			}
 			callback.pluginStateChanged(getState());
 		}
 
@@ -923,6 +1041,34 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			callback.pluginStateChanged(getState());
 		}
 
+		synchronized void setOrConnectionStatus(String orName, String status) {
+			if (status.equals("CONNECTED")) {
+				if (!orConnections.add(orName)) {
+					LOG.warning("Duplicate OR connection");
+				}
+			} else {
+				orConnections.remove(orName);
+				if (orConnections.isEmpty()) descriptorsUploaded = 0;
+			}
+			if (LOG.isLoggable(INFO)) {
+				LOG.info(orConnections.size() + " OR connections");
+			}
+			callback.pluginStateChanged(getState());
+		}
+
+		// Doesn't affect getState()
+		synchronized void descriptorUploaded() {
+			if (networkEnabled && !orConnections.isEmpty()) {
+				descriptorsUploaded++;
+			} else {
+				LOG.warning("Descriptor was uploaded with no OR connection");
+			}
+		}
+
+		synchronized boolean isDescriptorPublished() {
+			return descriptorsUploaded >= MIN_DESCRIPTORS_UPLOADED;
+		}
+
 		// Doesn't affect getState()
 		synchronized boolean setServerSocket(ServerSocket ss) {
 			if (stopped || serverSocket != null) return false;
@@ -942,7 +1088,8 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			if (reasonsDisabled != 0) return DISABLED;
 			if (!networkInitialised) return ENABLING;
 			if (!networkEnabled) return INACTIVE;
-			return bootstrapped && circuitBuilt ? ACTIVE : ENABLING;
+			return bootstrapped && circuitBuilt && !orConnections.isEmpty()
+					? ACTIVE : ENABLING;
 		}
 
 		synchronized int getReasonsDisabled() {

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

@@ -30,6 +30,7 @@ import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager.ClientVersioningHook;
 
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.Map;
 import java.util.Map.Entry;
 
@@ -41,6 +42,7 @@ import static org.briarproject.bramble.api.properties.TransportPropertyConstants
 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.util.StringUtils.isNullOrEmpty;
 
 @Immutable
 @NotNullByDefault
@@ -272,14 +274,22 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 				LatestUpdate latest = findLatest(txn, localGroup.getId(), t,
 						true);
 				if (latest == null) {
-					merged = p;
+					merged = new TransportProperties(p);
+					Iterator<String> it = merged.values().iterator();
+					while (it.hasNext()) {
+						if (isNullOrEmpty(it.next())) it.remove();
+					}
 					changed = true;
 				} else {
 					BdfList message = clientHelper.getMessageAsList(txn,
 							latest.messageId);
 					TransportProperties old = parseProperties(message);
 					merged = new TransportProperties(old);
-					merged.putAll(p);
+					for (Entry<String, String> e : p.entrySet()) {
+						String key = e.getKey(), value = e.getValue();
+						if (isNullOrEmpty(value)) merged.remove(key);
+						else merged.put(key, value);
+					}
 					changed = !merged.equals(old);
 				}
 				if (changed) {

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

@@ -1,63 +0,0 @@
-package org.briarproject.bramble.plugin;
-
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.junit.Test;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
-public class BackoffImplTest extends BrambleTestCase {
-
-	private static final int MIN_INTERVAL = 60 * 1000;
-	private static final int MAX_INTERVAL = 60 * 60 * 1000;
-	private static final double BASE = 1.2;
-
-	@Test
-	public void testPollingIntervalStartsAtMinimum() {
-		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
-		assertEquals(MIN_INTERVAL, b.getPollingInterval());
-	}
-
-	@Test
-	public void testIncrementIncreasesPollingInterval() {
-		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
-		b.increment();
-		assertTrue(b.getPollingInterval() > MIN_INTERVAL);
-	}
-
-	@Test
-	public void testResetResetsPollingInterval() {
-		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
-		b.increment();
-		b.increment();
-		b.reset();
-		assertEquals(MIN_INTERVAL, b.getPollingInterval());
-	}
-
-	@Test
-	public void testBaseAffectsBackoffSpeed() {
-		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
-		b.increment();
-		int interval = b.getPollingInterval();
-		BackoffImpl b1 = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE * 2);
-		b1.increment();
-		int interval1 = b1.getPollingInterval();
-		assertTrue(interval < interval1);
-	}
-
-	@Test
-	public void testIntervalDoesNotExceedMaxInterval() {
-		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL, BASE);
-		for (int i = 0; i < 100; i++) b.increment();
-		assertEquals(MAX_INTERVAL, b.getPollingInterval());
-	}
-
-	@Test
-	public void testIntervalDoesNotExceedMaxIntervalWithInfiniteMultiplier() {
-		BackoffImpl b = new BackoffImpl(MIN_INTERVAL, MAX_INTERVAL,
-				Double.POSITIVE_INFINITY);
-		b.increment();
-		assertEquals(MAX_INTERVAL, b.getPollingInterval());
-	}
-}
-

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

@@ -12,7 +12,6 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.plugin.event.ConnectionClosedEvent;
-import org.briarproject.bramble.api.plugin.event.ConnectionOpenedEvent;
 import org.briarproject.bramble.api.plugin.event.TransportActiveEvent;
 import org.briarproject.bramble.api.plugin.event.TransportInactiveEvent;
 import org.briarproject.bramble.api.plugin.simplex.SimplexPlugin;
@@ -157,22 +156,20 @@ public class PollerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testRescheduleOnOutgoingConnectionClosed() {
+	public void testDoesNotReconnectOnOutgoingConnectionClosed() {
 		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
 
 		context.checking(new Expectations() {{
 			allowing(plugin).getId();
 			will(returnValue(transportId));
 		}});
-		expectReschedule(plugin);
 
 		poller.eventOccurred(new ConnectionClosedEvent(contactId, transportId,
 				false, false));
 	}
 
 	@Test
-	public void testRescheduleAndReconnectOnOutgoingConnectionFailed()
+	public void testReconnectsOnOutgoingConnectionFailed() throws Exception {
-			throws Exception {
 		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
 		DuplexTransportConnection duplexConnection =
 				context.mock(DuplexTransportConnection.class);
@@ -181,7 +178,6 @@ public class PollerImplTest extends BrambleMockTestCase {
 			allowing(plugin).getId();
 			will(returnValue(transportId));
 		}});
-		expectReschedule(plugin);
 		expectReconnect(plugin, duplexConnection);
 
 		poller.eventOccurred(new ConnectionClosedEvent(contactId, transportId,
@@ -189,147 +185,31 @@ public class PollerImplTest extends BrambleMockTestCase {
 	}
 
 	@Test
-	public void testRescheduleOnIncomingConnectionClosed() {
+	public void testDoesNotReconnectOnIncomingConnectionClosed() {
 		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
 
 		context.checking(new Expectations() {{
 			allowing(plugin).getId();
 			will(returnValue(transportId));
 		}});
-		expectReschedule(plugin);
 
 		poller.eventOccurred(new ConnectionClosedEvent(contactId, transportId,
 				true, false));
 	}
 
 	@Test
-	public void testRescheduleOnIncomingConnectionFailed() {
+	public void testDoesNotReconnectOnIncomingConnectionFailed() {
 		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
 
 		context.checking(new Expectations() {{
 			allowing(plugin).getId();
 			will(returnValue(transportId));
 		}});
-		expectReschedule(plugin);
 
 		poller.eventOccurred(new ConnectionClosedEvent(contactId, transportId,
 				true, false));
 	}
 
-	@Test
-	public void testRescheduleOnConnectionOpened() {
-		Plugin plugin = context.mock(Plugin.class);
-
-		context.checking(new Expectations() {{
-			allowing(plugin).getId();
-			will(returnValue(transportId));
-			// Get the plugin
-			oneOf(pluginManager).getPlugin(transportId);
-			will(returnValue(plugin));
-			// The plugin supports polling
-			oneOf(plugin).shouldPoll();
-			will(returnValue(true));
-			// Schedule the next poll
-			oneOf(plugin).getPollingInterval();
-			will(returnValue(pollingInterval));
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(now));
-			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval), with(MILLISECONDS));
-			will(returnValue(future));
-		}});
-
-		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
-				false));
-	}
-
-	@Test
-	public void testRescheduleDoesNotReplaceEarlierTask() {
-		Plugin plugin = context.mock(Plugin.class);
-
-		context.checking(new Expectations() {{
-			allowing(plugin).getId();
-			will(returnValue(transportId));
-			// First event
-			// Get the plugin
-			oneOf(pluginManager).getPlugin(transportId);
-			will(returnValue(plugin));
-			// The plugin supports polling
-			oneOf(plugin).shouldPoll();
-			will(returnValue(true));
-			// Schedule the next poll
-			oneOf(plugin).getPollingInterval();
-			will(returnValue(pollingInterval));
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(now));
-			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval), with(MILLISECONDS));
-			will(returnValue(future));
-			// Second event
-			// Get the plugin
-			oneOf(pluginManager).getPlugin(transportId);
-			will(returnValue(plugin));
-			// The plugin supports polling
-			oneOf(plugin).shouldPoll();
-			will(returnValue(true));
-			// Don't replace the previously scheduled task, due earlier
-			oneOf(plugin).getPollingInterval();
-			will(returnValue(pollingInterval));
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(now + 1));
-		}});
-
-		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
-				false));
-		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
-				false));
-	}
-
-	@Test
-	public void testRescheduleReplacesLaterTask() {
-		Plugin plugin = context.mock(Plugin.class);
-
-		context.checking(new Expectations() {{
-			allowing(plugin).getId();
-			will(returnValue(transportId));
-			// First event
-			// Get the plugin
-			oneOf(pluginManager).getPlugin(transportId);
-			will(returnValue(plugin));
-			// The plugin supports polling
-			oneOf(plugin).shouldPoll();
-			will(returnValue(true));
-			// Schedule the next poll
-			oneOf(plugin).getPollingInterval();
-			will(returnValue(pollingInterval));
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(now));
-			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval), with(MILLISECONDS));
-			will(returnValue(future));
-			// Second event
-			// Get the plugin
-			oneOf(pluginManager).getPlugin(transportId);
-			will(returnValue(plugin));
-			// The plugin supports polling
-			oneOf(plugin).shouldPoll();
-			will(returnValue(true));
-			// Replace the previously scheduled task, due later
-			oneOf(plugin).getPollingInterval();
-			will(returnValue(pollingInterval - 2));
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(now + 1));
-			oneOf(future).cancel(false);
-			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval - 2), with(MILLISECONDS));
-		}});
-
-		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
-				false));
-		poller.eventOccurred(new ConnectionOpenedEvent(contactId, transportId,
-				false));
-	}
-
 	@Test
 	public void testPollsOnTransportActivated() throws Exception {
 		DuplexPlugin plugin = context.mock(DuplexPlugin.class);
@@ -441,25 +321,6 @@ public class PollerImplTest extends BrambleMockTestCase {
 		poller.eventOccurred(new TransportInactiveEvent(transportId));
 	}
 
-	private void expectReschedule(Plugin plugin) {
-		context.checking(new Expectations() {{
-			// Get the plugin
-			oneOf(pluginManager).getPlugin(transportId);
-			will(returnValue(plugin));
-			// The plugin supports polling
-			oneOf(plugin).shouldPoll();
-			will(returnValue(true));
-			// Schedule the next poll
-			oneOf(plugin).getPollingInterval();
-			will(returnValue(pollingInterval));
-			oneOf(clock).currentTimeMillis();
-			will(returnValue(now));
-			oneOf(scheduler).schedule(with(any(Runnable.class)),
-					with((long) pollingInterval), with(MILLISECONDS));
-			will(returnValue(future));
-		}});
-	}
-
 	private void expectReconnect(DuplexPlugin plugin,
 			DuplexTransportConnection duplexConnection) throws Exception {
 		context.checking(new Expectations() {{

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

@@ -3,7 +3,6 @@ package org.briarproject.bramble.plugin.tcp;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.Plugin.State;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
@@ -42,7 +41,6 @@ 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;
@@ -51,7 +49,7 @@ public class LanTcpPluginTest extends BrambleTestCase {
 	@Before
 	public void setUp() {
 		callback = new Callback();
-		plugin = new LanTcpPlugin(ioExecutor, backoff, callback, 0, 0, 1000) {
+		plugin = new LanTcpPlugin(ioExecutor, callback, 0, 0, 0, 1000) {
 			@Override
 			protected boolean canConnectToOwnAddress() {
 				return true;
@@ -347,20 +345,4 @@ public class LanTcpPluginTest extends BrambleTestCase {
 		public void handleWriter(TransportConnectionWriter w) {
 		}
 	}
-
-	private static class TestBackoff implements Backoff {
-
-		@Override
-		public int getPollingInterval() {
-			return 60 * 1000;
-		}
-
-		@Override
-		public void increment() {
-		}
-
-		@Override
-		public void reset() {
-		}
-	}
 }

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

@@ -566,6 +566,10 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		Contact contact = getContact();
 		Group contactGroup = getGroup(CLIENT_ID, MAJOR_VERSION);
 
+		// Property with an empty value should be discarded
+		TransportProperties properties = new TransportProperties(fooProperties);
+		properties.put("fooKey3", "");
+
 		context.checking(new DbExpectations() {{
 			oneOf(db).transaction(with(false), withDbRunnable(txn));
 			// There are no existing properties to merge with
@@ -589,7 +593,7 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		}});
 
 		TransportPropertyManagerImpl t = createInstance();
-		t.mergeLocalProperties(new TransportId("foo"), fooProperties);
+		t.mergeLocalProperties(new TransportId("foo"), properties);
 	}
 
 	@Test
@@ -605,16 +609,24 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		MessageId localGroupUpdateId = new MessageId(getRandomId());
 		Map<MessageId, BdfDictionary> localGroupMessageMetadata =
 				singletonMap(localGroupUpdateId, oldMetadata);
+
 		MessageId contactGroupUpdateId = new MessageId(getRandomId());
 		Map<MessageId, BdfDictionary> contactGroupMessageMetadata =
 				singletonMap(contactGroupUpdateId, oldMetadata);
+
 		TransportProperties oldProperties = new TransportProperties();
 		oldProperties.put("fooKey1", "oldFooValue1");
+		oldProperties.put("fooKey3", "oldFooValue3");
 		BdfDictionary oldPropertiesDict = BdfDictionary.of(
-				new BdfEntry("fooKey1", "oldFooValue1")
+				new BdfEntry("fooKey1", "oldFooValue1"),
+				new BdfEntry("fooKey3", "oldFooValue3")
 		);
 		BdfList oldUpdate = BdfList.of("foo", 1, oldPropertiesDict);
 
+		// Property assigned an empty value should be removed
+		TransportProperties properties = new TransportProperties(fooProperties);
+		properties.put("fooKey3", "");
+
 		context.checking(new DbExpectations() {{
 			oneOf(db).transaction(with(false), withDbRunnable(txn));
 			// Merge the new properties with the existing properties
@@ -647,7 +659,7 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 		}});
 
 		TransportPropertyManagerImpl t = createInstance();
-		t.mergeLocalProperties(new TransportId("foo"), fooProperties);
+		t.mergeLocalProperties(new TransportId("foo"), properties);
 	}
 
 	private void expectGetLocalProperties(Transaction txn) throws Exception {

bramble-java/src/main/java/org/briarproject/bramble/plugin/DesktopPluginModule.java

@@ -5,7 +5,6 @@ import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.BluetoothConstants;
 import org.briarproject.bramble.api.plugin.LanTcpConstants;
 import org.briarproject.bramble.api.plugin.PluginConfig;
@@ -37,18 +36,16 @@ public class DesktopPluginModule extends PluginModule {
 
 	@Provides
 	PluginConfig getPluginConfig(@IoExecutor Executor ioExecutor,
-			SecureRandom random, BackoffFactory backoffFactory,
+			SecureRandom random, ReliabilityLayerFactory reliabilityFactory,
-			ReliabilityLayerFactory reliabilityFactory,
 			ShutdownManager shutdownManager, EventBus eventBus,
 			TimeoutMonitor timeoutMonitor) {
 		DuplexPluginFactory bluetooth = new JavaBluetoothPluginFactory(
-				ioExecutor, random, eventBus, timeoutMonitor, backoffFactory);
+				ioExecutor, random, eventBus, timeoutMonitor);
 		DuplexPluginFactory modem = new ModemPluginFactory(ioExecutor,
 				reliabilityFactory);
-		DuplexPluginFactory lan = new LanTcpPluginFactory(ioExecutor, eventBus,
+		DuplexPluginFactory lan = new LanTcpPluginFactory(ioExecutor, eventBus);
-				backoffFactory);
 		DuplexPluginFactory wan = new WanTcpPluginFactory(ioExecutor, eventBus,
-				backoffFactory, shutdownManager);
+				shutdownManager);
 		Collection<DuplexPluginFactory> duplex =
 				asList(bluetooth, modem, lan, wan);
 		@NotNullByDefault

bramble-java/src/main/java/org/briarproject/bramble/plugin/bluetooth/JavaBluetoothPlugin.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.plugin.bluetooth;
 import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 
@@ -36,10 +35,10 @@ class JavaBluetoothPlugin extends BluetoothPlugin<StreamConnectionNotifier> {
 
 	JavaBluetoothPlugin(BluetoothConnectionLimiter connectionManager,
 			TimeoutMonitor timeoutMonitor, Executor ioExecutor,
-			SecureRandom secureRandom, Backoff backoff,
+			SecureRandom secureRandom, PluginCallback callback, int maxLatency,
-			PluginCallback callback, int maxLatency, int maxIdleTime) {
+			int maxIdleTime, int pollingInterval) {
 		super(connectionManager, timeoutMonitor, ioExecutor, secureRandom,
-				backoff, callback, maxLatency, maxIdleTime);
+				callback, maxLatency, maxIdleTime, pollingInterval);
 	}
 
 	@Override

bramble-java/src/main/java/org/briarproject/bramble/plugin/bluetooth/JavaBluetoothPluginFactory.java

@@ -3,8 +3,6 @@ package org.briarproject.bramble.plugin.bluetooth;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
@@ -15,32 +13,30 @@ import java.util.concurrent.Executor;
 
 import javax.annotation.concurrent.Immutable;
 
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
 
 @Immutable
 @NotNullByDefault
 public class JavaBluetoothPluginFactory implements DuplexPluginFactory {
 
-	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_LATENCY = (int) SECONDS.toMillis(30);
-	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = (int) SECONDS.toMillis(30);
-	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int POLLING_INTERVAL = (int) MINUTES.toMillis(2);
-	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
-	private static final double BACKOFF_BASE = 1.2;
 
 	private final Executor ioExecutor;
 	private final SecureRandom secureRandom;
 	private final EventBus eventBus;
 	private final TimeoutMonitor timeoutMonitor;
-	private final BackoffFactory backoffFactory;
 
 	public JavaBluetoothPluginFactory(Executor ioExecutor,
 			SecureRandom secureRandom, EventBus eventBus,
-			TimeoutMonitor timeoutMonitor, BackoffFactory backoffFactory) {
+			TimeoutMonitor timeoutMonitor) {
 		this.ioExecutor = ioExecutor;
 		this.secureRandom = secureRandom;
 		this.eventBus = eventBus;
 		this.timeoutMonitor = timeoutMonitor;
-		this.backoffFactory = backoffFactory;
 	}
 
 	@Override
@@ -57,11 +53,9 @@ public class JavaBluetoothPluginFactory implements DuplexPluginFactory {
 	public DuplexPlugin createPlugin(PluginCallback callback) {
 		BluetoothConnectionLimiter connectionLimiter =
 				new BluetoothConnectionLimiterImpl(eventBus);
-		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
-				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		JavaBluetoothPlugin plugin = new JavaBluetoothPlugin(connectionLimiter,
-				timeoutMonitor, ioExecutor, secureRandom, backoff, callback,
+				timeoutMonitor, ioExecutor, secureRandom, callback, MAX_LATENCY,
-				MAX_LATENCY, MAX_IDLE_TIME);
+				MAX_IDLE_TIME, POLLING_INTERVAL);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/JavaTorPlugin.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.plugin.tor;
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
@@ -24,14 +23,16 @@ abstract class JavaTorPlugin extends TorPlugin {
 			LocationUtils locationUtils, SocketFactory torSocketFactory,
 			Clock clock, ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager, Backoff backoff,
+			BatteryManager batteryManager,
 			TorRendezvousCrypto torRendezvousCrypto,
 			PluginCallback callback, String architecture, int maxLatency,
-			int maxIdleTime, File torDirectory) {
+			int maxIdleTime, int initialPollingInterval,
+			int stablePollingInterval, File torDirectory) {
 		super(ioExecutor, networkManager, locationUtils, torSocketFactory,
 				clock, resourceProvider, circumventionProvider, batteryManager,
-				backoff, torRendezvousCrypto, callback, architecture,
+				torRendezvousCrypto, callback, architecture, maxLatency,
-				maxLatency, maxIdleTime, torDirectory);
+				maxIdleTime, initialPollingInterval, stablePollingInterval,
+				torDirectory);
 	}
 
 	@Override

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/UnixTorPlugin.java

@@ -6,7 +6,6 @@ import com.sun.jna.Native;
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
@@ -24,14 +23,16 @@ class UnixTorPlugin extends JavaTorPlugin {
 			LocationUtils locationUtils, SocketFactory torSocketFactory,
 			Clock clock, ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
-			BatteryManager batteryManager, Backoff backoff,
+			BatteryManager batteryManager,
 			TorRendezvousCrypto torRendezvousCrypto,
 			PluginCallback callback, String architecture, int maxLatency,
-			int maxIdleTime, File torDirectory) {
+			int maxIdleTime, int initialPollingInterval,
+			int stablePollingInterval, File torDirectory) {
 		super(ioExecutor, networkManager, locationUtils, torSocketFactory,
 				clock, resourceProvider, circumventionProvider, batteryManager,
-				backoff, torRendezvousCrypto, callback, architecture,
+				torRendezvousCrypto, callback, architecture,
-				maxLatency, maxIdleTime, torDirectory);
+				maxLatency, maxIdleTime, initialPollingInterval,
+				stablePollingInterval, torDirectory);
 	}
 
 	@Override

bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/UnixTorPluginFactory.java

@@ -4,8 +4,6 @@ import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.Backoff;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.PluginCallback;
 import org.briarproject.bramble.api.plugin.TorConstants;
 import org.briarproject.bramble.api.plugin.TransportId;
@@ -22,6 +20,8 @@ import java.util.logging.Logger;
 import javax.annotation.concurrent.Immutable;
 import javax.net.SocketFactory;
 
+import static java.util.concurrent.TimeUnit.MINUTES;
+import static java.util.concurrent.TimeUnit.SECONDS;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.OsUtils.isLinux;
 
@@ -32,18 +32,28 @@ public class UnixTorPluginFactory implements DuplexPluginFactory {
 	private static final Logger LOG =
 			getLogger(UnixTorPluginFactory.class.getName());
 
-	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_LATENCY = (int) SECONDS.toMillis(30);
-	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = (int) SECONDS.toMillis(30);
-	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+
-	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
+	/**
-	private static final double BACKOFF_BASE = 1.2;
+	 * How often to poll before our hidden service becomes reachable.
+	 */
+	private static final int INITIAL_POLLING_INTERVAL =
+			(int) MINUTES.toMillis(1);
+
+	/**
+	 * How often to poll when our hidden service is reachable. Our contacts
+	 * will poll when they come online, so our polling is just a fallback in
+	 * case of repeated connection failures.
+	 */
+	private static final int STABLE_POLLING_INTERVAL =
+			(int) MINUTES.toMillis(15);
 
 	private final Executor ioExecutor;
 	private final NetworkManager networkManager;
 	private final LocationUtils locationUtils;
 	private final EventBus eventBus;
 	private final SocketFactory torSocketFactory;
-	private final BackoffFactory backoffFactory;
 	private final ResourceProvider resourceProvider;
 	private final CircumventionProvider circumventionProvider;
 	private final BatteryManager batteryManager;
@@ -53,7 +63,7 @@ public class UnixTorPluginFactory implements DuplexPluginFactory {
 	public UnixTorPluginFactory(Executor ioExecutor,
 			NetworkManager networkManager, LocationUtils locationUtils,
 			EventBus eventBus, SocketFactory torSocketFactory,
-			BackoffFactory backoffFactory, ResourceProvider resourceProvider,
+			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager, Clock clock, File torDirectory) {
 		this.ioExecutor = ioExecutor;
@@ -61,7 +71,6 @@ public class UnixTorPluginFactory implements DuplexPluginFactory {
 		this.locationUtils = locationUtils;
 		this.eventBus = eventBus;
 		this.torSocketFactory = torSocketFactory;
-		this.backoffFactory = backoffFactory;
 		this.resourceProvider = resourceProvider;
 		this.circumventionProvider = circumventionProvider;
 		this.batteryManager = batteryManager;
@@ -94,14 +103,13 @@ public class UnixTorPluginFactory implements DuplexPluginFactory {
 			return null;
 		}
 
-		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
-				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		TorRendezvousCrypto torRendezvousCrypto = new TorRendezvousCryptoImpl();
 		UnixTorPlugin plugin = new UnixTorPlugin(ioExecutor, networkManager,
 				locationUtils, torSocketFactory, clock, resourceProvider,
-				circumventionProvider, batteryManager, backoff,
+				circumventionProvider, batteryManager, torRendezvousCrypto,
-				torRendezvousCrypto, callback, architecture, MAX_LATENCY,
+				callback, architecture, MAX_LATENCY, MAX_IDLE_TIME,
-				MAX_IDLE_TIME, torDirectory);
+				INITIAL_POLLING_INTERVAL, STABLE_POLLING_INTERVAL,
+				torDirectory);
 		eventBus.addListener(plugin);
 		return plugin;
 	}

bramble-java/src/test/java/org/briarproject/bramble/plugin/tor/BridgeTest.java

@@ -5,7 +5,6 @@ import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.network.NetworkManager;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
@@ -69,8 +68,6 @@ public class BridgeTest extends BrambleTestCase {
 	@Inject
 	EventBus eventBus;
 	@Inject
-	BackoffFactory backoffFactory;
-	@Inject
 	Clock clock;
 
 	private final File torDir = getTestDirectory();
@@ -120,9 +117,8 @@ public class BridgeTest extends BrambleTestCase {
 			}
 		};
 		factory = new UnixTorPluginFactory(ioExecutor, networkManager,
-				locationUtils, eventBus, torSocketFactory, backoffFactory,
+				locationUtils, eventBus, torSocketFactory, resourceProvider,
-				resourceProvider, bridgeProvider, batteryManager, clock,
+				bridgeProvider, batteryManager, clock, torDir);
-				torDir);
 	}
 
 	@After

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

@@ -164,7 +164,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		nc.setLockscreenVisibility(VISIBILITY_SECRET);
 		nc.enableVibration(true);
 		nc.enableLights(true);
-		nc.setLightColor(getColor(appContext, R.color.briar_green_light));
+		nc.setLightColor(getColor(appContext, R.color.briar_lime_400));
 		notificationManager.createNotificationChannel(nc);
 	}
 

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

@@ -19,7 +19,6 @@ import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.plugin.BackoffFactory;
 import org.briarproject.bramble.api.plugin.BluetoothConstants;
 import org.briarproject.bramble.api.plugin.LanTcpConstants;
 import org.briarproject.bramble.api.plugin.PluginConfig;
@@ -127,23 +126,22 @@ public class AppModule {
 	PluginConfig providePluginConfig(@IoExecutor Executor ioExecutor,
 			@Scheduler ScheduledExecutorService scheduler,
 			AndroidExecutor androidExecutor, SecureRandom random,
-			SocketFactory torSocketFactory, BackoffFactory backoffFactory,
+			SocketFactory torSocketFactory, Application app,
-			Application app, NetworkManager networkManager,
+			NetworkManager networkManager, LocationUtils locationUtils,
-			LocationUtils locationUtils, EventBus eventBus,
+			EventBus eventBus, ResourceProvider resourceProvider,
-			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager, Clock clock,
 			TimeoutMonitor timeoutMonitor) {
 		Context appContext = app.getApplicationContext();
 		DuplexPluginFactory bluetooth = new AndroidBluetoothPluginFactory(
 				ioExecutor, scheduler, androidExecutor, appContext, random,
-				eventBus, clock, timeoutMonitor, backoffFactory);
+				eventBus, clock, timeoutMonitor);
 		DuplexPluginFactory tor = new AndroidTorPluginFactory(ioExecutor,
 				scheduler, appContext, networkManager, locationUtils, eventBus,
-				torSocketFactory, backoffFactory, resourceProvider,
+				torSocketFactory, resourceProvider, circumventionProvider,
-				circumventionProvider, batteryManager, clock);
+				batteryManager, clock);
 		DuplexPluginFactory lan = new AndroidLanTcpPluginFactory(ioExecutor,
-				eventBus, backoffFactory, appContext);
+				eventBus, appContext);
 		Collection<DuplexPluginFactory> duplex = asList(bluetooth, tor, lan);
 		@NotNullByDefault
 		PluginConfig pluginConfig = new PluginConfig() {

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

@@ -76,7 +76,7 @@ public class PendingContactListActivity extends BriarActivity
 		list.showProgressBar();
 
 		offlineSnackbar = new BriarSnackbarBuilder()
-				.setBackgroundColor(R.color.briar_red)
+				.setBackgroundColor(R.color.briar_red_500)
 				.make(list, R.string.offline_state, LENGTH_INDEFINITE);
 	}
 

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

@@ -46,11 +46,11 @@ class PendingContactViewHolder extends ViewHolder {
 		});
 
 		int color = ContextCompat
-				.getColor(status.getContext(), R.color.briar_green);
+				.getColor(status.getContext(), R.color.briar_lime_600);
 		switch (item.getState()) {
 			case WAITING_FOR_CONNECTION:
-				color = ContextCompat
+				color = ContextCompat.getColor(status.getContext(),
-						.getColor(status.getContext(), R.color.briar_yellow);
+						R.color.briar_orange_500);
 				status.setText(R.string.waiting_for_contact_to_come_online);
 				break;
 			case OFFLINE:
@@ -64,7 +64,7 @@ class PendingContactViewHolder extends ViewHolder {
 				break;
 			case FAILED:
 				color = ContextCompat
-						.getColor(status.getContext(), R.color.briar_red);
+						.getColor(status.getContext(), R.color.briar_red_500);
 				status.setText(R.string.adding_contact_failed);
 				break;
 			default:

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

@@ -41,7 +41,8 @@ class ConversationMessageViewHolder extends ConversationItemViewHolder {
 
 		// remember original status text color
 		timeColor = time.getCurrentTextColor();
-		timeColorBubble = getColor(v.getContext(), R.color.briar_white);
+		timeColorBubble =
+				getColor(v.getContext(), R.color.msg_status_bubble_foreground);
 
 		// clone constraint sets from layout files
 		textConstraints.clone(v.getContext(),

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

@@ -299,7 +299,7 @@ public class ImageActivity extends BriarActivity
 		int stringRes = error ?
 				R.string.save_image_error : R.string.save_image_success;
 		int colorRes = error ?
-				R.color.briar_red : R.color.briar_primary;
+				R.color.briar_red_500 : R.color.briar_primary;
 		new BriarSnackbarBuilder()
 				.setBackgroundColor(colorRes)
 				.make(layout, stringRes, LENGTH_LONG)

briar-android/src/main/java/org/briarproject/briar/android/navdrawer/NavDrawerActivity.java

@@ -432,8 +432,8 @@ public class NavDrawerActivity extends BriarActivity implements
 
 	@ColorRes
 	private int getIconColor(State state) {
-		if (state == ACTIVE) return R.color.briar_green_light;
+		if (state == ACTIVE) return R.color.briar_lime_400;
-		else if (state == ENABLING) return R.color.briar_yellow;
+		else if (state == ENABLING) return R.color.briar_orange_500;
 		else return android.R.color.tertiary_text_light;
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/settings/SettingsFragment.java

@@ -75,6 +75,9 @@ import static androidx.core.view.ViewCompat.LAYOUT_DIRECTION_LTR;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.plugin.Plugin.PREF_PLUGIN_ENABLE;
+import static org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_PREF_TOR_MOBILE;
+import static org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_PREF_TOR_NETWORK;
+import static org.briarproject.bramble.api.plugin.TorConstants.DEFAULT_PREF_TOR_ONLY_WHEN_CHARGING;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_MOBILE;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK;
 import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_AUTOMATIC;
@@ -372,9 +375,9 @@ public class SettingsFragment extends PreferenceFragmentCompat
 
 	// TODO: Remove after a reasonable migration period (added 2020-06-25)
 	private Settings migrateTorSettings(Settings s) {
-		int network = s.getInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_AUTOMATIC);
+		int network = s.getInt(PREF_TOR_NETWORK, DEFAULT_PREF_TOR_NETWORK);
 		if (network == PREF_TOR_NETWORK_NEVER) {
-			s.putInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_AUTOMATIC);
+			s.putInt(PREF_TOR_NETWORK, DEFAULT_PREF_TOR_NETWORK);
 			s.putBoolean(PREF_PLUGIN_ENABLE, false);
 			// We don't need to save the migrated settings - the Tor plugin is
 			// responsible for that. This code just handles the case where the
@@ -388,29 +391,32 @@ public class SettingsFragment extends PreferenceFragmentCompat
 			// due to events, we might try to display before a load completed
 			if (!settingsLoaded) return;
 
-			boolean btEnabledSetting =
+			boolean btEnabledSetting = btSettings.getBoolean(PREF_PLUGIN_ENABLE,
-					btSettings.getBoolean(PREF_PLUGIN_ENABLE, false);
+					BluetoothConstants.DEFAULT_PREF_PLUGIN_ENABLE);
 			enableBluetooth.setChecked(btEnabledSetting);
 
 			boolean wifiEnabledSetting =
-					wifiSettings.getBoolean(PREF_PLUGIN_ENABLE, false);
+					wifiSettings.getBoolean(PREF_PLUGIN_ENABLE,
+							LanTcpConstants.DEFAULT_PREF_PLUGIN_ENABLE);
 			enableWifi.setChecked(wifiEnabledSetting);
 
 			boolean torEnabledSetting =
-					torSettings.getBoolean(PREF_PLUGIN_ENABLE, true);
+					torSettings.getBoolean(PREF_PLUGIN_ENABLE,
+							TorConstants.DEFAULT_PREF_PLUGIN_ENABLE);
 			enableTor.setChecked(torEnabledSetting);
 
 			int torNetworkSetting = torSettings.getInt(PREF_TOR_NETWORK,
-					PREF_TOR_NETWORK_AUTOMATIC);
+					DEFAULT_PREF_TOR_NETWORK);
 			torNetwork.setValue(Integer.toString(torNetworkSetting));
 			setTorNetworkSummary(torNetworkSetting);
 
-			boolean torMobileSetting =
+			boolean torMobileSetting = torSettings.getBoolean(PREF_TOR_MOBILE,
-					torSettings.getBoolean(PREF_TOR_MOBILE, true);
+					DEFAULT_PREF_TOR_MOBILE);
 			torMobile.setChecked(torMobileSetting);
 
 			boolean torChargingSetting =
-					torSettings.getBoolean(PREF_TOR_ONLY_WHEN_CHARGING, false);
+					torSettings.getBoolean(PREF_TOR_ONLY_WHEN_CHARGING,
+							DEFAULT_PREF_TOR_ONLY_WHEN_CHARGING);
 			torOnlyWhenCharging.setChecked(torChargingSetting);
 
 			displayScreenLockSetting();

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

@@ -20,7 +20,7 @@ public class BriarNotificationBuilder extends NotificationCompat.Builder {
 		// https://issuetracker.google.com/issues/36961721
 		setAutoCancel(true);
 
-		setLights(ContextCompat.getColor(context, R.color.briar_green_light),
+		setLights(ContextCompat.getColor(context, R.color.briar_lime_400),
 				750, 500);
 		if (SDK_INT >= 21) setVisibility(VISIBILITY_PRIVATE);
 	}

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

@@ -11,7 +11,7 @@
 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:fillColor="#82c91e"
 		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

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

@@ -17,12 +17,12 @@
 		android:fillColor="#ffffff"
 		android:pathData="M175.3 16.5l-9.8 0 0 -5.7c0 -1.4 -1.2 -2.6 -2.6 -2.6l-19.3 0c-1.4 0 -2.6 1.2 -2.6 2.6l0 14.4c0 1.4 1.2 2.6 2.6 2.6l15.1 0 0 17.3c0 2.4 2 4.4 4.4 4.4l12.2 0c2.4 0 4.4 -2 4.4 -4.4l0 -24.2c0.1 -2.4 -1.9 -4.4 -4.4 -4.4zm-12.4 -5.9l-9.6 6 -9.6 -6 19.2 0zm-19.4 14.8l0 -12.3 9.8 6.1 9.8 -6.1 0 12.3 -19.6 0zm28.6 21.2l-5.8 0 0 -1.5 5.8 0 0 1.5zm5 -4.6l-15.8 0 0 -14.2 1.6 0c1.4 0 2.6 -1.2 2.6 -2.6l0 -4.1 11.6 0 0 20.9z"/>
 	<path
-		android:fillColor="#ff0000"
+		android:fillColor="#db3b21"
 		android:pathData="M101.4 17.8l2 2 7.4 -7.3 7.3 7.3 2.1 -2 -7.4 -7.4 7.4 -7.3 -2.1 -2.1 -7.3 7.4 -7.4 -7.4 -2 2.1 7.3 7.3z"/>
 	<path
-		android:fillColor="#ff0000"
+		android:fillColor="#db3b21"
 		android:pathData="M176 17.8l2.1 2 7.3 -7.3 7.4 7.3 2 -2 -7.3 -7.4 7.3 -7.3 -2 -2.1 -7.4 7.4 -7.3 -7.4 -2.1 2.1 7.3 7.3z"/>
 	<path
-		android:fillColor="#08b124"
+		android:fillColor="#67a60f"
 		android:pathData="M35.8 18.8l0 0L52.5 2.1 50.5 0 35.6 14.8 28.5 7.7l-2.1 2.1 9.2 9.1z"/>
 </vector>

briar-android/src/main/res/drawable/bubble_completed.xml

@@ -7,7 +7,7 @@
 		android:radius="32dp"/>
 
 	<solid
-		android:color="@color/briar_green"/>
+		android:color="@color/briar_lime_600"/>
 
 </shape>
 

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

@@ -13,7 +13,7 @@ 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:pathData="M0,0 L24,0 L24,24 L0,24 Z"/>
 	<path
-		android:fillColor="#95d220"
+		android:fillColor="#82c91e"
 		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

briar-android/src/main/res/drawable/contact_offline.xml

@@ -6,7 +6,7 @@
         android:viewportWidth="24">
 
 	<path
-		android:fillColor="#2D3E50"
+		android:fillColor="#2e3d4f"
 		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

briar-android/src/main/res/drawable/contact_online.xml

@@ -6,7 +6,7 @@
         android:viewportWidth="24">
 
 	<path
-		android:fillColor="#95D220"
+		android:fillColor="#82c91e"
 		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

briar-android/src/main/res/drawable/ic_content_copy.xml

@@ -1,7 +1,7 @@
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
         android:width="24dp"
         android:height="24dp"
-        android:tint="#2A93C6"
+        android:tint="#418cd8"
         android:viewportHeight="24.0"
         android:viewportWidth="24.0">
 	<path

briar-android/src/main/res/drawable/ic_content_paste.xml

@@ -1,7 +1,7 @@
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
         android:width="24dp"
         android:height="24dp"
-        android:tint="#2A93C6"
+        android:tint="#418cd8"
         android:viewportHeight="24.0"
         android:viewportWidth="24.0">
 	<path

briar-android/src/main/res/drawable/ic_image_broken.xml

@@ -4,6 +4,6 @@
         android:viewportHeight="24.0"
         android:viewportWidth="24.0">
 	<path
-		android:fillColor="#808080"
+		android:fillColor="#707070"
 		android:pathData="M21,5v6.59l-3,-3.01 -4,4.01 -4,-4 -4,4 -3,-3.01L3,5c0,-1.1 0.9,-2 2,-2h14c1.1,0 2,0.9 2,2zM18,11.42l3,3.01L21,19c0,1.1 -0.9,2 -2,2L5,21c-1.1,0 -2,-0.9 -2,-2v-6.58l3,2.99 4,-4 4,4 4,-3.99z"/>
 </vector>

briar-android/src/main/res/drawable/ic_more_vert_accent.xml

@@ -4,6 +4,6 @@
         android:viewportHeight="24.0"
         android:viewportWidth="24.0">
 	<path
-		android:fillColor="#FF2D3E50"
+		android:fillColor="#2e3d4f"
 		android:pathData="M12,8c1.1,0 2,-0.9 2,-2s-0.9,-2 -2,-2 -2,0.9 -2,2 0.9,2 2,2zM12,10c-1.1,0 -2,0.9 -2,2s0.9,2 2,2 2,-0.9 2,-2 -0.9,-2 -2,-2zM12,16c-1.1,0 -2,0.9 -2,2s0.9,2 2,2 2,-0.9 2,-2 -0.9,-2 -2,-2z"/>
 </vector>

briar-android/src/main/res/drawable/ic_rss_feed.xml

@@ -6,7 +6,7 @@
         android:viewportWidth="30">
 
 	<path
-		android:fillColor="#ffa500"
+		android:fillColor="#fc9403"
 		android:pathData="M0,0 L30,0 L30,30 L0,30 L0,0 Z"/>
 	<path
 		android:fillColor="#ffffff"

briar-android/src/main/res/drawable/qr_code_explanation.xml

@@ -18,12 +18,12 @@
 		android:fillColor="#000000"
 		android:pathData="M175.3 16.5l-9.8 0 0 -5.7c0 -1.4 -1.2 -2.6 -2.6 -2.6l-19.3 0c-1.4 0 -2.6 1.2 -2.6 2.6l0 14.4c0 1.4 1.2 2.6 2.6 2.6l15.1 0 0 17.3c0 2.4 2 4.4 4.4 4.4l12.2 0c2.4 0 4.4 -2 4.4 -4.4l0 -24.2c0.1 -2.4 -1.9 -4.4 -4.4 -4.4zm-12.4 -5.9l-9.6 6 -9.6 -6 19.2 0zm-19.4 14.8l0 -12.3 9.8 6.1 9.8 -6.1 0 12.3 -19.6 0zm28.6 21.2l-5.8 0 0 -1.5 5.8 0 0 1.5zm5 -4.6l-15.8 0 0 -14.2 1.6 0c1.4 0 2.6 -1.2 2.6 -2.6l0 -4.1 11.6 0 0 20.9z"/>
 	<path
-		android:fillColor="#ff0000"
+		android:fillColor="#db3b21"
 		android:pathData="M101.4 17.8l2 2 7.4 -7.3 7.3 7.3 2.1 -2 -7.4 -7.4 7.4 -7.3 -2.1 -2.1 -7.3 7.4 -7.4 -7.4 -2 2.1 7.3 7.3z"/>
 	<path
-		android:fillColor="#ff0000"
+		android:fillColor="#db3b21"
 		android:pathData="M176 17.8l2.1 2 7.3 -7.3 7.4 7.3 2 -2 -7.3 -7.4 7.3 -7.3 -2 -2.1 -7.4 7.4 -7.3 -7.4 -2.1 2.1 7.3 7.3z"/>
 	<path
-		android:fillColor="#08b124"
+		android:fillColor="#67a60f"
 		android:pathData="M35.8 18.8l0 0L52.5 2.1 50.5 0 35.6 14.8 28.5 7.7l-2.1 2.1 9.2 9.1z"/>
 </vector>

briar-android/src/main/res/drawable/social_share_blue.xml

@@ -1,7 +1,7 @@
 <vector xmlns:android="http://schemas.android.com/apk/res/android"
         android:width="24dp"
         android:height="24dp"
-        android:tint="#2A93C6"
+        android:tint="#418cd8"
         android:viewportHeight="24.0"
         android:viewportWidth="24.0">
 	<path

briar-android/src/main/res/drawable/trust_indicator_anonymous.xml

@@ -5,7 +5,7 @@
         android:viewportHeight="20"
         android:viewportWidth="49">
 	<path
-		android:fillColor="#b7b7b7"
+		android:fillColor="#a7a7a7"
 		android:pathData="M15.5002,13.8797 L15.5002,11.8208 L12.9502,11.8208 L12.9502,8.38194
 L15.5002,8.38194 L15.5002,6.32312 L12.9502,6.32312 L12.9502,2.49959
 L10.5752,2.49959 L10.5752,6.32312 L7.42514,6.32312 L7.42514,2.49959
@@ -16,7 +16,7 @@ L10.5752,13.8797 L10.5752,17.4996 L12.9502,17.4996 L12.9502,13.8797
 L15.5002,13.8797 Z M10.5752,11.8208 L7.42514,11.8208 L7.42514,8.38194
 L10.5752,8.38194 L10.5752,11.8208 Z"/>
 	<path
-		android:fillColor="#b7b7b7"
+		android:fillColor="#a7a7a7"
 		android:pathData="M31.0002,13.8797 L31.0002,11.8208 L28.4502,11.8208 L28.4502,8.38194
 L31.0002,8.38194 L31.0002,6.32312 L28.4502,6.32312 L28.4502,2.49959
 L26.0752,2.49959 L26.0752,6.32312 L22.9251,6.32312 L22.9251,2.49959
@@ -27,7 +27,7 @@ L26.0752,13.8797 L26.0752,17.4996 L28.4502,17.4996 L28.4502,13.8797
 L31.0002,13.8797 Z M26.0752,11.8208 L22.9251,11.8208 L22.9251,8.38194
 L26.0752,8.38194 L26.0752,11.8208 Z"/>
 	<path
-		android:fillColor="#b7b7b7"
+		android:fillColor="#a7a7a7"
 		android:pathData="M46.5002,13.8797 L46.5002,11.8208 L43.9502,11.8208 L43.9502,8.38194
 L46.5002,8.38194 L46.5002,6.32312 L43.9502,6.32312 L43.9502,2.49959
 L41.5752,2.49959 L41.5752,6.32312 L38.4251,6.32312 L38.4251,2.49959

briar-android/src/main/res/drawable/trust_indicator_unknown.xml

@@ -5,7 +5,7 @@
         android:viewportHeight="20"
         android:viewportWidth="49">
 	<path
-		android:fillColor="#c34032"
+		android:fillColor="#db3b21"
 		android:pathData="M15.5002,13.8797 L15.5002,11.8208 L12.9502,11.8208 L12.9502,8.38194
 L15.5002,8.38194 L15.5002,6.32312 L12.9502,6.32312 L12.9502,2.49959
 L10.5752,2.49959 L10.5752,6.32312 L7.42514,6.32312 L7.42514,2.49959
@@ -16,7 +16,7 @@ L10.5752,13.8797 L10.5752,17.4996 L12.9502,17.4996 L12.9502,13.8797
 L15.5002,13.8797 Z M10.5752,11.8208 L7.42514,11.8208 L7.42514,8.38194
 L10.5752,8.38194 L10.5752,11.8208 Z"/>
 	<path
-		android:fillColor="#b7b7b7"
+		android:fillColor="#a7a7a7"
 		android:pathData="M31.0002,13.8797 L31.0002,11.8208 L28.4502,11.8208 L28.4502,8.38194
 L31.0002,8.38194 L31.0002,6.32312 L28.4502,6.32312 L28.4502,2.49959
 L26.0752,2.49959 L26.0752,6.32312 L22.9251,6.32312 L22.9251,2.49959
@@ -27,7 +27,7 @@ L26.0752,13.8797 L26.0752,17.4996 L28.4502,17.4996 L28.4502,13.8797
 L31.0002,13.8797 Z M26.0752,11.8208 L22.9251,11.8208 L22.9251,8.38194
 L26.0752,8.38194 L26.0752,11.8208 Z"/>
 	<path
-		android:fillColor="#b7b7b7"
+		android:fillColor="#a7a7a7"
 		android:pathData="M46.5002,13.8797 L46.5002,11.8208 L43.9502,11.8208 L43.9502,8.38194
 L46.5002,8.38194 L46.5002,6.32312 L43.9502,6.32312 L43.9502,2.49959
 L41.5752,2.49959 L41.5752,6.32312 L38.4251,6.32312 L38.4251,2.49959

briar-android/src/main/res/drawable/trust_indicator_unverified.xml

@@ -5,7 +5,7 @@
         android:viewportHeight="20"
         android:viewportWidth="49">
 	<path
-		android:fillColor="#fcd53a"
+		android:fillColor="#fc9403"
 		android:pathData="M15.5002,13.8797 L15.5002,11.8208 L12.9502,11.8208 L12.9502,8.38194
 L15.5002,8.38194 L15.5002,6.32312 L12.9502,6.32312 L12.9502,2.49959
 L10.5752,2.49959 L10.5752,6.32312 L7.42514,6.32312 L7.42514,2.49959
@@ -16,7 +16,7 @@ L10.5752,13.8797 L10.5752,17.4996 L12.9502,17.4996 L12.9502,13.8797
 L15.5002,13.8797 Z M10.5752,11.8208 L7.42514,11.8208 L7.42514,8.38194
 L10.5752,8.38194 L10.5752,11.8208 Z"/>
 	<path
-		android:fillColor="#fcd53a"
+		android:fillColor="#fc9403"
 		android:pathData="M31.0002,13.8797 L31.0002,11.8208 L28.4502,11.8208 L28.4502,8.38194
 L31.0002,8.38194 L31.0002,6.32312 L28.4502,6.32312 L28.4502,2.49959
 L26.0752,2.49959 L26.0752,6.32312 L22.9251,6.32312 L22.9251,2.49959
@@ -27,7 +27,7 @@ L26.0752,13.8797 L26.0752,17.4996 L28.4502,17.4996 L28.4502,13.8797
 L31.0002,13.8797 Z M26.0752,11.8208 L22.9251,11.8208 L22.9251,8.38194
 L26.0752,8.38194 L26.0752,11.8208 Z"/>
 	<path
-		android:fillColor="#b7b7b7"
+		android:fillColor="#a7a7a7"
 		android:pathData="M46.5002,13.8797 L46.5002,11.8208 L43.9502,11.8208 L43.9502,8.38194
 L46.5002,8.38194 L46.5002,6.32312 L43.9502,6.32312 L43.9502,2.49959
 L41.5752,2.49959 L41.5752,6.32312 L38.4251,6.32312 L38.4251,2.49959

briar-android/src/main/res/drawable/trust_indicator_verified.xml

@@ -5,7 +5,7 @@
         android:viewportHeight="20"
         android:viewportWidth="49">
 	<path
-		android:fillColor="#7fac49"
+		android:fillColor="#67a60f"
 		android:pathData="M15.5002,13.8797 L15.5002,11.8208 L12.9502,11.8208 L12.9502,8.38194
 L15.5002,8.38194 L15.5002,6.32312 L12.9502,6.32312 L12.9502,2.49959
 L10.5752,2.49959 L10.5752,6.32312 L7.42514,6.32312 L7.42514,2.49959
@@ -16,7 +16,7 @@ L10.5752,13.8797 L10.5752,17.4996 L12.9502,17.4996 L12.9502,13.8797
 L15.5002,13.8797 Z M10.5752,11.8208 L7.42514,11.8208 L7.42514,8.38194
 L10.5752,8.38194 L10.5752,11.8208 Z"/>
 	<path
-		android:fillColor="#7fac49"
+		android:fillColor="#67a60f"
 		android:pathData="M31.0002,13.8797 L31.0002,11.8208 L28.4502,11.8208 L28.4502,8.38194
 L31.0002,8.38194 L31.0002,6.32312 L28.4502,6.32312 L28.4502,2.49959
 L26.0752,2.49959 L26.0752,6.32312 L22.9251,6.32312 L22.9251,2.49959
@@ -27,7 +27,7 @@ L26.0752,13.8797 L26.0752,17.4996 L28.4502,17.4996 L28.4502,13.8797
 L31.0002,13.8797 Z M26.0752,11.8208 L22.9251,11.8208 L22.9251,8.38194
 L26.0752,8.38194 L26.0752,11.8208 Z"/>
 	<path
-		android:fillColor="#7fac49"
+		android:fillColor="#67a60f"
 		android:pathData="M46.5002,13.8797 L46.5002,11.8208 L43.9502,11.8208 L43.9502,8.38194
 L46.5002,8.38194 L46.5002,6.32312 L43.9502,6.32312 L43.9502,2.49959
 L41.5752,2.49959 L41.5752,6.32312 L38.4251,6.32312 L38.4251,2.49959

briar-android/src/main/res/layout/activity_image.xml

@@ -4,14 +4,13 @@
 	android:id="@+id/layout"
 	android:layout_width="match_parent"
 	android:layout_height="match_parent"
-	android:background="@color/briar_black"
+	android:background="@android:color/black"
 	tools:context=".android.conversation.ImageActivity">
 
 	<androidx.viewpager.widget.ViewPager
 		android:id="@+id/viewPager"
 		android:layout_width="match_parent"
-		android:layout_height="match_parent"
+		android:layout_height="match_parent" />
-		tools:background="@color/briar_green_light" />
 
 	<com.google.android.material.appbar.AppBarLayout
 		android:id="@+id/appBarLayout"

briar-android/src/main/res/layout/fragment_link_dialog.xml

@@ -60,7 +60,7 @@
 				android:layout_gravity="center_vertical"
 				android:layout_marginTop="16dp"
 				android:layout_marginBottom="16dp"
-				android:background="@color/briar_white"
+				android:background="@android:color/white"
 				android:padding="8dp"
 				android:textColor="@color/briar_text_primary"
 				android:textIsSelectable="true"

briar-android/src/main/res/layout/fragment_link_exchange.xml

@@ -84,7 +84,7 @@
 			android:src="@drawable/ic_call_made"
 			app:layout_constraintStart_toStartOf="parent"
 			app:layout_constraintTop_toBottomOf="@+id/stepOneText"
-			app:tint="@color/briar_white" />
+			app:tint="@android:color/white" />
 
 		<TextView
 			android:id="@+id/yourLink"
@@ -105,7 +105,7 @@
 			android:layout_width="0dp"
 			android:layout_height="wrap_content"
 			android:layout_marginTop="16dp"
-			android:background="@color/briar_white"
+			android:background="@android:color/white"
 			android:ellipsize="end"
 			android:padding="8dp"
 			android:singleLine="true"
@@ -160,7 +160,7 @@
 			android:src="@drawable/ic_call_received"
 			app:layout_constraintStart_toStartOf="parent"
 			app:layout_constraintTop_toBottomOf="@+id/copyButton"
-			app:tint="@color/briar_white" />
+			app:tint="@android:color/white" />
 
 		<TextView
 			android:id="@+id/inputLink"

briar-android/src/main/res/layout/fragment_nickname.xml

@@ -97,7 +97,7 @@
 			app:layout_constraintBottom_toTopOf="@+id/contactNameLayout"
 			app:layout_constraintStart_toStartOf="parent"
 			app:layout_constraintTop_toBottomOf="@+id/imageView"
-			app:tint="@color/briar_white" />
+			app:tint="@android:color/white" />
 
 		<TextView
 			android:id="@+id/nicknameIntro"

briar-android/src/main/res/layout/list_item_pending_contact.xml

@@ -60,7 +60,7 @@
 		app:layout_constraintEnd_toStartOf="@+id/time"
 		app:layout_constraintStart_toStartOf="@+id/name"
 		app:layout_constraintTop_toBottomOf="@+id/name"
-		tools:textColor="@color/briar_red" />
+		tools:textColor="@color/briar_red_500" />
 
 	<TextView
 		android:id="@+id/time"

briar-android/src/main/res/values-night/color.xml

@@ -1,29 +1,29 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-	<color name="briar_primary">@color/briar_blue_dark</color>
+	<color name="briar_primary">@color/briar_night_800</color>
-	<color name="briar_accent">@color/briar_green</color>
+	<color name="briar_accent">@color/briar_lime_600</color>
 
 	<color name="preference_category">@color/briar_accent</color>
-	<color name="preference_category_background">@color/briar_black_almost</color>
+	<color name="preference_category_background">@color/briar_night_950</color>
 
-	<color name="color_primary">@color/briar_white</color>
+	<color name="color_primary">@android:color/white</color>
 
-	<color name="msg_in">@color/briar_blue</color>
+	<color name="msg_in">@color/briar_night_700</color>
-	<color name="msg_out">@color/briar_blue_elio_light</color>
+	<color name="msg_out">@color/briar_blue_600</color>
-	<color name="notice_in">@color/briar_blue_dark</color>
+	<color name="notice_in">@color/briar_night_800</color>
-	<color name="notice_out">@color/briar_blue_elio</color>
+	<color name="notice_out">@color/briar_blue_800</color>
 	<color name="msg_stroke">@color/msg_stroke_dark</color>
 
-	<color name="window_background">@color/briar_blue_very_dark</color>
+	<color name="window_background">@color/briar_night_950</color>
-	<color name="card_background">@color/briar_blue_dark</color>
+	<color name="card_background">@color/briar_night_800</color>
-	<color name="item_background_highlight">@color/briar_blue</color>
+	<color name="item_background_highlight">@color/briar_night_700</color>
 
-	<color name="briar_button_background_color">@color/briar_blue_medium</color>
+	<color name="briar_button_background_color">@color/briar_night_500</color>
-	<color name="briar_button_text_neutral">@color/briar_blue_light</color>
+	<color name="briar_button_text_neutral">@color/briar_blue_400</color>
 	<color name="briar_button_text_disabled">#23cccccc</color>
 
-	<color name="thread_indicator">@color/briar_blue</color>
+	<color name="thread_indicator">@color/briar_night_700</color>
-	<color name="thread_item_highlight">@color/briar_black</color>
+	<color name="thread_item_highlight">@android:color/black</color>
 
-	<color name="divider">@color/briar_black</color>
+	<color name="divider">@android:color/black</color>
 </resources>

briar-android/src/main/res/values/color.xml

@@ -1,68 +1,75 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-	<color name="briar_blue">#2D3E50</color>
+	<color name="briar_lime_600">#67a60f</color>
-	<color name="briar_blue_dark">#222E3C</color>
+	<color name="briar_lime_400">#82c91e</color>
-	<color name="briar_blue_very_dark">#0F1720</color>
-	<color name="briar_blue_medium">#4F6C8C</color>
-	<color name="briar_blue_elio">#236087</color>
-	<color name="briar_blue_elio_light">#3C80A9</color>
-	<color name="briar_blue_light">#2A93C6</color>
-	<color name="briar_blue_grey">#EBEFF2</color>
-	<color name="briar_yellow">#9e9d24</color>
-	<color name="briar_green">#5C940D</color>
-	<color name="briar_green_light">#95D220</color>
-	<color name="briar_red">#ff0000</color>
-	<color name="briar_white">#FFFFFF</color>
-	<color name="briar_black">#000000</color>
-	<color name="briar_black_almost">#080C10</color>
 
-	<color name="m_grey_300">#e0e0e0</color>
+	<color name="briar_blue_800">#134a81</color>
-	<color name="m_grey_500">#9e9e9e</color>
+	<color name="briar_blue_600">#1b69b6</color>
-	<color name="m_blue_grey_50">#eceff1</color>
+	<color name="briar_blue_400">#418cd8</color>
 
-	<color name="briar_primary">@color/briar_blue</color>
+	<color name="briar_orange_500">#fc9403</color>
-	<color name="briar_primary_dark">@color/briar_blue_very_dark</color>
-	<color name="briar_accent">@color/briar_blue</color>
 
-	<color name="window_background">#EBEBEB</color>
+	<color name="briar_red_500">#db3b21</color>
+
+	<color name="briar_night_950">#0e171f</color>
+	<color name="briar_night_800">#212d3b</color>
+	<color name="briar_night_700">#2e3d4f</color>
+	<color name="briar_night_500">#435b77</color>
+	<color name="briar_night_50">#ebf3fa</color>
+
+	<color name="briar_gray_900">#2e2e2e</color>
+	<color name="briar_gray_500">#a7a7a7</color>
+	<color name="briar_gray_300">#cccccc</color>
+	<color name="briar_gray_200">#dfdfdf</color>
+	<color name="briar_gray_100">#f2f2f2</color>
+
+	<color name="briar_brand_blue">@color/briar_night_700</color>
+	<color name="briar_brand_green">@color/briar_lime_400</color>
+
+	<color name="briar_primary">@color/briar_brand_blue</color>
+	<color name="briar_primary_dark">@color/briar_night_950</color>
+	<color name="briar_accent">@color/briar_brand_blue</color>
+
+	<color name="window_background">@color/briar_gray_100</color>
 	<color name="card_background">@color/cardview_light_background</color>
-	<color name="item_background_highlight">#DCDCDC</color>
+	<color name="item_background_highlight">@color/briar_gray_200</color>
-	<color name="briar_warning_background">@color/briar_red</color>
+	<color name="briar_warning_background">@color/briar_red_500</color>
-	<color name="action_bar_text">@color/briar_white</color>
+	<color name="action_bar_text">@android:color/white</color>
-	<color name="private_message_date_inverse">@color/m_grey_300</color>
+	<color name="private_message_date_inverse">@color/briar_gray_200</color>
 	<color name="forum_avatar_shadow">#99000000</color>
 
 	<color name="color_primary">#dd000000</color>
 
-	<color name="msg_in">@color/briar_white</color>
+	<color name="msg_in">@android:color/white</color>
-	<color name="msg_out">@color/briar_blue_elio_light</color>
+	<color name="msg_out">@color/briar_blue_400</color>
-	<color name="notice_in">@color/briar_blue_grey</color>
+	<color name="notice_in">@color/briar_night_50</color>
-	<color name="notice_out">@color/briar_blue_elio</color>
+	<color name="notice_out">@color/briar_blue_600</color>
-	<color name="msg_stroke_light">#cbcbcb</color>
+	<color name="msg_stroke_light">@color/briar_gray_300</color>
-	<color name="msg_stroke_dark">#333333</color>
+	<color name="msg_stroke_dark">@color/briar_gray_900</color>
 	<color name="msg_stroke">@color/msg_stroke_light</color>
 	<color name="msg_status_bubble_background">#66000000</color>
+	<color name="msg_status_bubble_foreground">@android:color/white</color>
 	<color name="msg_selected_background">@color/briar_accent</color>
 
 	<!-- text colors -->
-	<color name="briar_text_link">@color/briar_blue_light</color>
+	<color name="briar_text_link">@color/briar_blue_400</color>
 	<color name="briar_text_primary">#df000000</color>
-	<color name="briar_text_primary_inverse">@color/briar_white</color>
+	<color name="briar_text_primary_inverse">@android:color/white</color>
 	<color name="briar_text_secondary_inverse">#b4ffffff</color>
 	<color name="briar_text_tertiary_inverse">#80ffffff</color>
 
-	<color name="preference_category">@color/briar_blue_medium</color>
+	<color name="preference_category">@color/briar_night_500</color>
 	<color name="preference_category_background">@color/window_background</color>
 
 	<color name="briar_button_background_color">@color/briar_accent</color>
-	<color name="briar_button_text_positive">@color/briar_blue_light</color>
+	<color name="briar_button_text_positive">@color/briar_blue_400</color>
-	<color name="briar_button_text_neutral">@color/briar_blue_medium</color>
+	<color name="briar_button_text_neutral">@color/briar_night_500</color>
-	<color name="briar_button_text_negative">@color/briar_red</color>
+	<color name="briar_button_text_negative">@color/briar_red_500</color>
 	<color name="briar_button_text_disabled">#28000000</color>
 
-	<color name="thread_indicator">@color/m_grey_500</color>
+	<color name="thread_indicator">@color/briar_gray_500</color>
 	<color name="thread_item_background">@color/window_background</color>
-	<color name="thread_item_highlight">@color/briar_white</color>
+	<color name="thread_item_highlight">@android:color/white</color>
 
-	<color name="divider">#c1c1c1</color>
+	<color name="divider">@color/briar_gray_200</color>
 </resources>

briar-android/src/main/res/values/styles.xml

@@ -130,7 +130,7 @@
 		<item name="android:layout_height">28dp</item>
 		<item name="android:background">@drawable/bubble_accent</item>
 		<item name="android:gravity">center</item>
-		<item name="android:textColor">@color/briar_white</item>
+		<item name="android:textColor">@android:color/white</item>
 		<item name="android:textSize">18sp</item>
 	</style>
 

briar-headless/src/main/java/org/briarproject/briar/headless/HeadlessModule.kt

@@ -9,7 +9,6 @@ import org.briarproject.bramble.api.db.DatabaseConfig
 import org.briarproject.bramble.api.event.EventBus
 import org.briarproject.bramble.api.lifecycle.IoExecutor
 import org.briarproject.bramble.api.network.NetworkManager
-import org.briarproject.bramble.api.plugin.BackoffFactory
 import org.briarproject.bramble.api.plugin.PluginConfig
 import org.briarproject.bramble.api.plugin.TransportId
 import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory
@@ -70,16 +69,15 @@ internal class HeadlessModule(private val appDir: File) {
     @Provides
     internal fun providePluginConfig(
         @IoExecutor ioExecutor: Executor, torSocketFactory: SocketFactory,
-        backoffFactory: BackoffFactory, networkManager: NetworkManager,
+        networkManager: NetworkManager, locationUtils: LocationUtils, eventBus: EventBus,
-        locationUtils: LocationUtils, eventBus: EventBus, resourceProvider: ResourceProvider,
+        resourceProvider: ResourceProvider, circumventionProvider: CircumventionProvider,
-        circumventionProvider: CircumventionProvider, batteryManager: BatteryManager, clock: Clock
+        batteryManager: BatteryManager, clock: Clock
     ): PluginConfig {
         val duplex: List<DuplexPluginFactory> = if (isLinux() || isMac()) {
             val torDirectory = File(appDir, "tor")
             val tor = UnixTorPluginFactory(
                 ioExecutor, networkManager, locationUtils, eventBus, torSocketFactory,
-                backoffFactory, resourceProvider, circumventionProvider, batteryManager, clock,
+                resourceProvider, circumventionProvider, batteryManager, clock, torDirectory
-                torDirectory
             )
             listOf(tor)
         } else {