Temporarily add self-built Windows tor binary

Until it's officially published by the Briar Project.

.gitlab-ci.yml

@@ -98,16 +98,16 @@ bridge test:
       allow_failure: true
   script:
     - OPTIONAL_TESTS=org.briarproject.bramble.plugin.tor.BridgeTest ./gradlew --info bramble-java:test --tests BridgeTest
-  timeout: 3h
 
 mailbox integration test:
   extends: .optional_tests
   rules:
     - if: '$CI_PIPELINE_SOURCE == "schedule"'
       when: on_success
+      allow_failure: false
     - if: '$CI_COMMIT_TAG == null'
       when: manual
-      allow_failure: true # TODO figure out how not to allow failure while leaving this optional
+      allow_failure: false
   script:
     # start mailbox
     - cd /opt && git clone --depth 1 https://code.briarproject.org/briar/briar-mailbox.git briar-mailbox
@@ -118,3 +118,10 @@ mailbox integration test:
     - cd "$CI_PROJECT_DIR"
     - bramble-core/src/test/bash/wait-for-mailbox.sh
     - OPTIONAL_TESTS=org.briarproject.bramble.mailbox.MailboxIntegrationTest ./gradlew --info bramble-core:test --tests MailboxIntegrationTest
+
+pre_release_tests:
+  extends: .optional_tests
+  script:
+    - OPTIONAL_TESTS=org.briarproject.bramble.plugin.tor.BridgeTest ./gradlew --info bramble-java:test --tests BridgeTest
+  only:
+    - tags

CONTRIBUTING.md

@@ -1,10 +0,0 @@
-Folder-Description:
-===================
-* `briar-*`: Specifically for the Briar app (Phone/Desktop/Headless)
-* `bramble-*`: The protocol stack - not necessarily Briar-dependent
-
----
-
-* `*-api`: public stuff that can be referenced from other packages and modules - mostly interfaces + a few utility classes
-* `*-core`: implementations of api that are portable across Android/Desktop/Headless
-* `*-java`: implementations of api that are specific to Desktop & Headless

bramble-android/build.gradle

@@ -15,8 +15,8 @@ android {
 	defaultConfig {
 		minSdkVersion 16
 		targetSdkVersion 30
-		versionCode 10411
+		versionCode 10404
-		versionName "1.4.11"
+		versionName "1.4.4"
 		consumerProguardFiles 'proguard-rules.txt'
 
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -43,7 +43,7 @@ configurations {
 dependencies {
 	implementation project(path: ':bramble-core', configuration: 'default')
 	tor "org.briarproject:tor-android:$tor_version"
-	tor "org.briarproject:obfs4proxy-android:$obfs4proxy_version"
+	tor "org.briarproject:obfs4proxy-android:$obfs4proxy_version@zip"
 
 	annotationProcessor "com.google.dagger:dagger-compiler:$dagger_version"
 
@@ -70,6 +70,11 @@ clean.dependsOn cleanTorBinaries
 
 task unpackTorBinaries {
 	doLast {
+		copy {
+			from configurations.tor.collect { zipTree(it) }
+			into torBinariesDir
+			include 'geoip.zip'
+		}
 		configurations.tor.each { outer ->
 			zipTree(outer).each { inner ->
 				if (inner.name.endsWith('_arm_pie.zip')) {

bramble-android/proguard-rules.txt

@@ -18,7 +18,3 @@
 -dontnote com.google.common.**
 
 -dontwarn com.fasterxml.jackson.databind.ext.Java7SupportImpl
-
-# Keep all Jackson-serialisable classes and their members
--keep interface com.fasterxml.jackson.databind.annotation.JsonSerialize
--keep @com.fasterxml.jackson.databind.annotation.JsonSerialize class * { *; }

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

@@ -1,7 +1,6 @@
 package org.briarproject.bramble;
 
 import org.briarproject.bramble.battery.AndroidBatteryModule;
-import org.briarproject.bramble.io.DnsModule;
 import org.briarproject.bramble.network.AndroidNetworkModule;
 import org.briarproject.bramble.plugin.tor.CircumventionModule;
 import org.briarproject.bramble.reporting.ReportingModule;
@@ -19,7 +18,6 @@ import dagger.Module;
 		AndroidTaskSchedulerModule.class,
 		AndroidWakefulIoExecutorModule.class,
 		CircumventionModule.class,
-		DnsModule.class,
 		ReportingModule.class,
 		SocksModule.class
 })

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

@@ -11,10 +11,7 @@ import android.net.LinkAddress;
 import android.net.LinkProperties;
 import android.net.Network;
 import android.net.NetworkInfo;
-import android.net.wifi.WifiInfo;
-import android.net.wifi.WifiManager;
 
-import org.briarproject.bramble.api.Cancellable;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.lifecycle.Service;
@@ -24,6 +21,7 @@ import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
 import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 
 import java.net.Inet4Address;
 import java.net.InetAddress;
@@ -40,7 +38,6 @@ import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static android.content.Context.CONNECTIVITY_SERVICE;
-import static android.content.Context.WIFI_SERVICE;
 import static android.content.Intent.ACTION_SCREEN_OFF;
 import static android.content.Intent.ACTION_SCREEN_ON;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
@@ -114,37 +111,15 @@ class AndroidNetworkManager implements NetworkManager, Service {
 
 	@Override
 	public NetworkStatus getNetworkStatus() {
-		// https://issuetracker.google.com/issues/175055271
+		NetworkInfo net = connectivityManager.getActiveNetworkInfo();
-		try {
+		boolean connected = net != null && net.isConnected();
-			NetworkInfo net = connectivityManager.getActiveNetworkInfo();
+		boolean wifi = false, ipv6Only = false;
-			boolean connected = net != null && net.isConnected();
+		if (connected) {
-			boolean wifi = false, ipv6Only = false;
+			wifi = net.getType() == TYPE_WIFI;
-			if (connected) {
+			if (SDK_INT >= 23) ipv6Only = isActiveNetworkIpv6Only();
-				wifi = net.getType() == TYPE_WIFI;
+			else ipv6Only = areAllAvailableNetworksIpv6Only();
-				if (SDK_INT >= 23) ipv6Only = isActiveNetworkIpv6Only();
-				else ipv6Only = areAllAvailableNetworksIpv6Only();
-			}
-			return new NetworkStatus(connected, wifi, ipv6Only);
-		} catch (SecurityException e) {
-			logException(LOG, WARNING, e);
-			// Without the ConnectivityManager we can't detect whether we have
-			// internet access. Assume we do, which is probably less harmful
-			// than assuming we don't. Likewise, assume the connection is
-			// IPv6-only. Fall back to the WifiManager to detect whether we
-			// have a wifi connection.
-			LOG.info("ConnectivityManager is broken, guessing connectivity");
-			boolean connected = true, wifi = false, ipv6Only = true;
-			WifiManager wm = (WifiManager) app.getSystemService(WIFI_SERVICE);
-			if (wm != null) {
-				WifiInfo info = wm.getConnectionInfo();
-				if (info != null && info.getIpAddress() != 0) {
-					LOG.info("Connected to wifi");
-					wifi = true;
-					ipv6Only = false;
-				}
-			}
-			return new NetworkStatus(connected, wifi, ipv6Only);
 		}
+		return new NetworkStatus(connected, wifi, ipv6Only);
 	}
 
 	/**
@@ -155,29 +130,23 @@ class AndroidNetworkManager implements NetworkManager, Service {
 	 */
 	@TargetApi(23)
 	private boolean isActiveNetworkIpv6Only() {
-		// https://issuetracker.google.com/issues/175055271
+		Network net = connectivityManager.getActiveNetwork();
-		try {
+		if (net == null) {
-			Network net = connectivityManager.getActiveNetwork();
+			LOG.info("No active network");
-			if (net == null) {
-				LOG.info("No active network");
-				return false;
-			}
-			LinkProperties props = connectivityManager.getLinkProperties(net);
-			if (props == null) {
-				LOG.info("No link properties for active network");
-				return false;
-			}
-			boolean hasIpv6Unicast = false;
-			for (LinkAddress linkAddress : props.getLinkAddresses()) {
-				InetAddress addr = linkAddress.getAddress();
-				if (addr instanceof Inet4Address) return false;
-				if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
-			}
-			return hasIpv6Unicast;
-		} catch (SecurityException e) {
-			logException(LOG, WARNING, e);
 			return false;
 		}
+		LinkProperties props = connectivityManager.getLinkProperties(net);
+		if (props == null) {
+			LOG.info("No link properties for active network");
+			return false;
+		}
+		boolean hasIpv6Unicast = false;
+		for (LinkAddress linkAddress : props.getLinkAddresses()) {
+			InetAddress addr = linkAddress.getAddress();
+			if (addr instanceof Inet4Address) return false;
+			if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
+		}
+		return hasIpv6Unicast;
 	}
 
 	/**

bramble-android/src/main/java/org/briarproject/bramble/plugin/file/AndroidRemovableDrivePlugin.java

@@ -32,22 +32,13 @@ class AndroidRemovableDrivePlugin extends RemovableDrivePlugin {
 	InputStream openInputStream(TransportProperties p) throws IOException {
 		String uri = p.get(PROP_URI);
 		if (isNullOrEmpty(uri)) throw new IllegalArgumentException();
-		try {
+		return app.getContentResolver().openInputStream(Uri.parse(uri));
-			return app.getContentResolver().openInputStream(Uri.parse(uri));
-		} catch (SecurityException e) {
-			throw new IOException(e);
-		}
 	}
 
 	@Override
 	OutputStream openOutputStream(TransportProperties p) throws IOException {
 		String uri = p.get(PROP_URI);
 		if (isNullOrEmpty(uri)) throw new IllegalArgumentException();
-		try {
+		return app.getContentResolver().openOutputStream(Uri.parse(uri));
-			return app.getContentResolver()
-					.openOutputStream(Uri.parse(uri), "wt");
-		} catch (SecurityException e) {
-			throw new IOException(e);
-		}
 	}
 }

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

@@ -175,24 +175,16 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 	@TargetApi(21)
 	@Nullable
 	private InetAddress getWifiClientIpv6Address() {
-		// https://issuetracker.google.com/issues/175055271
+		for (Network net : connectivityManager.getAllNetworks()) {
-		try {
+			NetworkCapabilities caps =
-			for (Network net : connectivityManager.getAllNetworks()) {
+					connectivityManager.getNetworkCapabilities(net);
-				NetworkCapabilities caps =
+			if (caps == null || !caps.hasTransport(TRANSPORT_WIFI)) continue;
-						connectivityManager.getNetworkCapabilities(net);
+			LinkProperties props = connectivityManager.getLinkProperties(net);
-				if (caps == null || !caps.hasTransport(TRANSPORT_WIFI)) {
+			if (props == null) continue;
-					continue;
+			for (LinkAddress linkAddress : props.getLinkAddresses()) {
-				}
+				InetAddress addr = linkAddress.getAddress();
-				LinkProperties props =
+				if (isIpv6LinkLocalAddress(addr)) return addr;
-						connectivityManager.getLinkProperties(net);
-				if (props == null) continue;
-				for (LinkAddress linkAddress : props.getLinkAddresses()) {
-					InetAddress addr = linkAddress.getAddress();
-					if (isIpv6LinkLocalAddress(addr)) return addr;
-				}
 			}
-		} catch (SecurityException e) {
-			logException(LOG, WARNING, e);
 		}
 		return null;
 	}
@@ -235,17 +227,12 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 	// network's socket factory may try to connect via another network
 	private SocketFactory getSocketFactory() {
 		if (SDK_INT < 21) return SocketFactory.getDefault();
-		// https://issuetracker.google.com/issues/175055271
+		for (Network net : connectivityManager.getAllNetworks()) {
-		try {
+			NetworkCapabilities caps =
-			for (Network net : connectivityManager.getAllNetworks()) {
+					connectivityManager.getNetworkCapabilities(net);
-				NetworkCapabilities caps =
+			if (caps != null && caps.hasTransport(TRANSPORT_WIFI)) {
-						connectivityManager.getNetworkCapabilities(net);
+				return net.getSocketFactory();
-				if (caps != null && caps.hasTransport(TRANSPORT_WIFI)) {
-					return net.getSocketFactory();
-				}
 			}
-		} catch (SecurityException e) {
-			logException(LOG, WARNING, e);
 		}
 		LOG.warning("Could not find suitable socket factory");
 		return SocketFactory.getDefault();

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

@@ -11,35 +11,62 @@ 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.TorControlPort;
 import org.briarproject.bramble.api.plugin.TorDirectory;
 import org.briarproject.bramble.api.plugin.TorSocksPort;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPlugin;
+import org.briarproject.bramble.api.plugin.duplex.DuplexPluginFactory;
 import org.briarproject.bramble.api.system.AndroidWakeLockManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
 import org.briarproject.bramble.api.system.WakefulIoExecutor;
+import org.briarproject.bramble.util.AndroidUtils;
 
 import java.io.File;
 import java.util.concurrent.Executor;
+import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 import javax.net.SocketFactory;
 
-import static org.briarproject.bramble.util.AndroidUtils.getSupportedArchitectures;
-
 @Immutable
 @NotNullByDefault
-public class AndroidTorPluginFactory extends TorPluginFactory {
+public class AndroidTorPluginFactory implements DuplexPluginFactory {
 
+	private static final Logger LOG =
+			Logger.getLogger(AndroidTorPluginFactory.class.getName());
+
+	private static final int MAX_LATENCY = 30 * 1000; // 30 seconds
+	private static final int MAX_IDLE_TIME = 30 * 1000; // 30 seconds
+	private static final int MIN_POLLING_INTERVAL = 60 * 1000; // 1 minute
+	private static final int MAX_POLLING_INTERVAL = 10 * 60 * 1000; // 10 mins
+	private static final double BACKOFF_BASE = 1.2;
+
+	private final Executor ioExecutor, wakefulIoExecutor;
 	private final Application app;
+	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;
 	private final AndroidWakeLockManager wakeLockManager;
+	private final Clock clock;
+	private final File torDirectory;
+	private int torSocksPort;
+	private int torControlPort;
+	private final CryptoComponent crypto;
 
 	@Inject
 	AndroidTorPluginFactory(@IoExecutor Executor ioExecutor,
 			@WakefulIoExecutor Executor wakefulIoExecutor,
+			Application app,
 			NetworkManager networkManager,
 			LocationUtils locationUtils,
 			EventBus eventBus,
@@ -48,43 +75,80 @@ public class AndroidTorPluginFactory extends TorPluginFactory {
 			ResourceProvider resourceProvider,
 			CircumventionProvider circumventionProvider,
 			BatteryManager batteryManager,
+			AndroidWakeLockManager wakeLockManager,
 			Clock clock,
-			CryptoComponent crypto,
 			@TorDirectory File torDirectory,
 			@TorSocksPort int torSocksPort,
 			@TorControlPort int torControlPort,
-			Application app,
+			CryptoComponent crypto) {
-			AndroidWakeLockManager wakeLockManager) {
+		this.ioExecutor = ioExecutor;
-		super(ioExecutor, wakefulIoExecutor, networkManager, locationUtils,
+		this.wakefulIoExecutor = wakefulIoExecutor;
-				eventBus, torSocketFactory, backoffFactory, resourceProvider,
-				circumventionProvider, batteryManager, clock, crypto,
-				torDirectory, torSocksPort, torControlPort);
 		this.app = app;
+		this.networkManager = networkManager;
+		this.locationUtils = locationUtils;
+		this.eventBus = eventBus;
+		this.torSocketFactory = torSocketFactory;
+		this.backoffFactory = backoffFactory;
+		this.resourceProvider = resourceProvider;
+		this.circumventionProvider = circumventionProvider;
+		this.batteryManager = batteryManager;
 		this.wakeLockManager = wakeLockManager;
+		this.clock = clock;
+		this.torDirectory = torDirectory;
+		this.torSocksPort = torSocksPort;
+		this.torControlPort = torControlPort;
+		this.crypto = crypto;
 	}
 
-	@Nullable
 	@Override
-	String getArchitectureForTorBinary() {
+	public TransportId getId() {
-		for (String abi : getSupportedArchitectures()) {
+		return TorConstants.ID;
-			if (abi.startsWith("x86_64")) return "x86_64_pie";
+	}
-			else if (abi.startsWith("x86")) return "x86_pie";
+
-			else if (abi.startsWith("arm64")) return "arm64_pie";
+	@Override
-			else if (abi.startsWith("armeabi")) return "arm_pie";
+	public long getMaxLatency() {
+		return MAX_LATENCY;
+	}
+
+	@Override
+	public DuplexPlugin createPlugin(PluginCallback callback) {
+
+		// Check that we have a Tor binary for this architecture
+		String architecture = null;
+		for (String abi : AndroidUtils.getSupportedArchitectures()) {
+			if (abi.startsWith("x86_64")) {
+				architecture = "x86_64";
+				break;
+			} else if (abi.startsWith("x86")) {
+				architecture = "x86";
+				break;
+			} else if (abi.startsWith("arm64")) {
+				architecture = "arm64";
+				break;
+			} else if (abi.startsWith("armeabi")) {
+				architecture = "arm";
+				break;
+			}
 		}
-		return null;
+		if (architecture == null) {
-	}
+			LOG.info("Tor is not supported on this architecture");
+			return null;
+		}
+		// Use position-independent executable
+		architecture += "_pie";
 
-	@Override
+		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
-	TorPlugin createPluginInstance(Backoff backoff,
+				MAX_POLLING_INTERVAL, BACKOFF_BASE);
-			TorRendezvousCrypto torRendezvousCrypto, PluginCallback callback,
+		TorRendezvousCrypto torRendezvousCrypto =
-			String architecture) {
+				new TorRendezvousCryptoImpl(crypto);
-		return new AndroidTorPlugin(ioExecutor,
+		AndroidTorPlugin plugin = new AndroidTorPlugin(ioExecutor,
 				wakefulIoExecutor, app, networkManager, locationUtils,
 				torSocketFactory, clock, resourceProvider,
 				circumventionProvider, batteryManager, wakeLockManager,
 				backoff, torRendezvousCrypto, callback, architecture,
 				MAX_LATENCY, MAX_IDLE_TIME, torDirectory, torSocksPort,
 				torControlPort);
+		eventBus.addListener(plugin);
+		return plugin;
 	}
 }

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

@@ -8,7 +8,6 @@ import android.content.Intent;
 import android.os.Process;
 import android.os.SystemClock;
 
-import org.briarproject.bramble.api.Cancellable;
 import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.system.AlarmListener;
@@ -117,12 +116,10 @@ class AndroidTaskScheduler implements TaskScheduler, Service, AlarmListener {
 		long dueMillis = now + MILLISECONDS.convert(delay, unit);
 		Runnable wakeful = () ->
 				wakeLockManager.executeWakefully(task, executor, "TaskHandoff");
-		// Acquire the lock before scheduling the check to ensure the check
+		Future<?> check = scheduleCheckForDueTasks(delay, unit);
-		// doesn't access the task queue before the task has been added
+		ScheduledTask s = new ScheduledTask(wakeful, dueMillis, check,
-		ScheduledTask s;
+				cancelled);
 		synchronized (lock) {
-			Future<?> check = scheduleCheckForDueTasks(delay, unit);
-			s = new ScheduledTask(wakeful, dueMillis, check, cancelled);
 			tasks.add(s);
 		}
 		return s;
@@ -139,7 +136,6 @@ class AndroidTaskScheduler implements TaskScheduler, Service, AlarmListener {
 		return schedule(wrapped, executor, delay, unit, cancelled);
 	}
 
-	@GuardedBy("lock")
 	private Future<?> scheduleCheckForDueTasks(long delay, TimeUnit unit) {
 		Runnable wakeful = () -> wakeLockManager.runWakefully(
 				this::runDueTasks, "TaskScheduler");
@@ -210,7 +206,7 @@ class AndroidTaskScheduler implements TaskScheduler, Service, AlarmListener {
 		private final Future<?> check;
 		private final AtomicBoolean cancelled;
 
-		private ScheduledTask(Runnable task, long dueMillis,
+		public ScheduledTask(Runnable task, long dueMillis,
 				Future<?> check, AtomicBoolean cancelled) {
 			this.task = task;
 			this.dueMillis = dueMillis;

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

@@ -4,7 +4,6 @@ import android.annotation.SuppressLint;
 import android.bluetooth.BluetoothAdapter;
 import android.content.Context;
 import android.os.Build;
-import android.os.Looper;
 import android.provider.Settings;
 
 import org.briarproject.bramble.api.Pair;
@@ -135,8 +134,4 @@ public class AndroidUtils {
 			return null;
 		}
 	}
-
-	public static boolean isUiThread() {
-		return Looper.myLooper() == Looper.getMainLooper();
-	}
 }

bramble-android/witness.gradle

@@ -87,8 +87,8 @@ dependencyVerification {
         'org.apache.httpcomponents:httpmime:4.5.6:httpmime-4.5.6.jar:0b2b1102c18d3c7e05a77214b9b7501a6f6056174ae5604e0e256776eda7553e',
         'org.bouncycastle:bcpkix-jdk15on:1.56:bcpkix-jdk15on-1.56.jar:7043dee4e9e7175e93e0b36f45b1ec1ecb893c5f755667e8b916eb8dd201c6ca',
         'org.bouncycastle:bcprov-jdk15on:1.56:bcprov-jdk15on-1.56.jar:963e1ee14f808ffb99897d848ddcdb28fa91ddda867eb18d303e82728f878349',
-        'org.briarproject:obfs4proxy-android:0.0.12:obfs4proxy-android-0.0.12.jar:84159d2a4668abc40e3fccaa1f6fa0c04892863f9eb80a866ac8928d9f9a7e89',
+        'org.briarproject:obfs4proxy-android:0.0.12-dev-40245c4a:obfs4proxy-android-0.0.12-dev-40245c4a.zip:8ab05a8f8391be2cb5ab2b665c281a06d9e3a756bd0f95a40a36ca927866ea82',
-        'org.briarproject:tor-android:0.4.5.12-2:tor-android-0.4.5.12-2.jar:8545dbcef2bb6aa89c32bb6f8ac51f7a64bce3ae85845b3578ffdeb9b206feb9',
+        'org.briarproject:tor-android:0.3.5.17:tor-android-0.3.5.17.jar:1888afc10a26b93d00a010ea27bf0b1b162a6d524688b08b98d70d14dc363b54',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
         'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
         'org.checkerframework:checker-qual:3.5.0:checker-qual-3.5.0.jar:729990b3f18a95606fc2573836b6958bcdb44cb52bfbd1b7aa9c339cff35a5a4',

bramble-api/build.gradle

@@ -5,12 +5,10 @@ targetCompatibility = 1.8
 apply plugin: 'ru.vyarus.animalsniffer'
 apply plugin: 'witness'
 apply from: 'witness.gradle'
-apply plugin: 'checkstyle'
 
 dependencies {
 	implementation "com.google.dagger:dagger:$dagger_version"
 	implementation 'com.google.code.findbugs:jsr305:3.0.2'
-	implementation "com.fasterxml.jackson.core:jackson-annotations:$jackson_version"
 
 	testImplementation "junit:junit:$junit_version"
 	testImplementation "org.jmock:jmock:$jmock_version"

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

@@ -1,6 +0,0 @@
-package org.briarproject.bramble.api;
-
-public interface Cancellable {
-
-	void cancel();
-}

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

@@ -11,8 +11,6 @@ public interface FeatureFlags {
 
 	boolean shouldEnableDisappearingMessages();
 
-	boolean shouldEnableMailbox();
-
 	boolean shouldEnablePrivateGroupsInCore();
 
 	boolean shouldEnableForumsInCore();

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

@@ -1,14 +1,8 @@
 package org.briarproject.bramble.api;
 
-import org.briarproject.bramble.util.StringUtils;
-
-import java.util.ArrayList;
 import java.util.Hashtable;
-import java.util.List;
 import java.util.Map;
 
-import javax.annotation.Nullable;
-
 public abstract class StringMap extends Hashtable<String, String> {
 
 	protected StringMap(Map<String, String> m) {
@@ -58,31 +52,4 @@ public abstract class StringMap extends Hashtable<String, String> {
 	public void putLong(String key, long value) {
 		put(key, String.valueOf(value));
 	}
-
-	@Nullable
-	public int[] getIntArray(String key) {
-		String s = get(key);
-		if (s == null) return null;
-		// Handle empty string because "".split(",") returns {""}
-		if (s.length() == 0) return new int[0];
-		String[] intStrings = s.split(",");
-		int[] ints = new int[intStrings.length];
-		try {
-			for (int i = 0; i < ints.length; i++) {
-				ints[i] = Integer.parseInt(intStrings[i]);
-			}
-		} catch (NumberFormatException e) {
-			return null;
-		}
-		return ints;
-	}
-
-	public void putIntArray(String key, int[] value) {
-		List<String> intStrings = new ArrayList<>();
-		for (int integer : value) {
-			intStrings.add(String.valueOf(integer));
-		}
-		// Puts empty string if input array value is empty
-		put(key, StringUtils.join(intStrings, ","));
-	}
 }

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

@@ -6,14 +6,14 @@ import javax.annotation.concurrent.ThreadSafe;
 
 @ThreadSafe
 @NotNullByDefault
-public class UniqueId extends Bytes {
+public abstract class UniqueId extends Bytes {
 
 	/**
 	 * The length of a unique identifier in bytes.
 	 */
 	public static final int LENGTH = 32;
 
-	public UniqueId(byte[] id) {
+	protected UniqueId(byte[] id) {
 		super(id);
 		if (id.length != LENGTH) throw new IllegalArgumentException();
 	}

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

@@ -9,8 +9,6 @@ import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
@@ -20,7 +18,6 @@ import org.briarproject.bramble.api.sync.MessageId;
 
 import java.security.GeneralSecurityException;
 import java.util.Collection;
-import java.util.List;
 import java.util.Map;
 
 @NotNullByDefault
@@ -126,19 +123,6 @@ public interface ClientHelper {
 	Map<TransportId, TransportProperties> parseAndValidateTransportPropertiesMap(
 			BdfDictionary properties) throws FormatException;
 
-	/**
-	 * Parse and validate the elements of a Mailbox update message.
-	 *
-	 * @return the parsed update message
-	 * @throws FormatException if the message elements are invalid
-	 */
-	MailboxUpdate parseAndValidateMailboxUpdate(BdfList clientSupports,
-			BdfList serverSupports, BdfDictionary properties)
-			throws FormatException;
-
-	List<MailboxVersion> parseMailboxVersionList(BdfList bdfList)
-			throws FormatException;
-
 	/**
 	 * Retrieves the contact ID from the group metadata of the given contact
 	 * group.

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

@@ -7,7 +7,6 @@ import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
-import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 
 @NotNullByDefault
 public interface ConnectionManager {
@@ -17,17 +16,6 @@ public interface ConnectionManager {
 	 */
 	void manageIncomingConnection(TransportId t, TransportConnectionReader r);
 
-	/**
-	 * Manages an incoming connection from a contact via a mailbox.
-	 * <p>
-	 * This method does not mark the tag as recognised until after the data
-	 * has been read from the {@link TransportConnectionReader}, at which
-	 * point the {@link TagController} is called to decide whether the tag
-	 * should be marked as recognised.
-	 */
-	void manageIncomingConnection(TransportId t, TransportConnectionReader r,
-			TagController c);
-
 	/**
 	 * Manages an incoming connection from a contact over a duplex transport.
 	 */
@@ -46,14 +34,6 @@ public interface ConnectionManager {
 	void manageOutgoingConnection(ContactId c, TransportId t,
 			TransportConnectionWriter w);
 
-	/**
-	 * Manages an outgoing connection to a contact via a mailbox. The IDs of
-	 * any messages sent or acked are added to the given
-	 * {@link OutgoingSessionRecord}.
-	 */
-	void manageOutgoingConnection(ContactId c, TransportId t,
-			TransportConnectionWriter w, OutgoingSessionRecord sessionRecord);
-
 	/**
 	 * Manages an outgoing connection to a contact over a duplex transport.
 	 */
@@ -66,21 +46,4 @@ public interface ConnectionManager {
 	 */
 	void manageOutgoingConnection(PendingContactId p, TransportId t,
 			DuplexTransportConnection d);
-
-	/**
-	 * An interface for controlling whether a tag should be marked as
-	 * recognised.
-	 */
-	interface TagController {
-		/**
-		 * This method is only called if a tag was read from the corresponding
-		 * {@link TransportConnectionReader} and recognised.
-		 *
-		 * @param exception True if an exception was thrown while reading from
-		 * the {@link TransportConnectionReader}, after successfully reading
-		 * and recognising the tag.
-		 * @return True if the tag should be marked as recognised.
-		 */
-		boolean shouldMarkTagAsRecognised(boolean exception);
-	}
 }

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

@@ -178,12 +178,6 @@ public interface ContactManager {
 	 */
 	void removePendingContact(PendingContactId p) throws DbException;
 
-	/**
-	 * Removes a {@link PendingContact}.
-	 */
-	void removePendingContact(Transaction txn, PendingContactId p)
-			throws DbException;
-
 	/**
 	 * Returns the contact with the given ID.
 	 */

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

@@ -3,6 +3,7 @@ package org.briarproject.bramble.api.contact;
 import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 
 /**
@@ -16,4 +17,9 @@ public class PendingContactId extends UniqueId {
 	public PendingContactId(byte[] id) {
 		super(id);
 	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+		return o instanceof PendingContactId && super.equals(o);
+	}
 }

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.api.crypto;
 
-import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.security.GeneralSecurityException;
@@ -11,8 +10,6 @@ import javax.annotation.Nullable;
 @NotNullByDefault
 public interface CryptoComponent {
 
-	UniqueId generateUniqueId();
-
 	SecretKey generateSecretKey();
 
 	SecureRandom getSecureRandom();
@@ -175,11 +172,9 @@ public interface CryptoComponent {
 	String asciiArmour(byte[] b, int lineLength);
 
 	/**
-	 * Encode the Onion given its public key. Specified here:
+	 * Encode the onion/hidden service address given its public key. As
-	 * https://gitweb.torproject.org/torspec.git/tree/rend-spec-v3.txt?id=29245fd5#n2135
+	 * specified here: https://gitweb.torproject.org/torspec.git/tree/rend-spec-v3.txt?id=29245fd5#n2135
-	 *
-	 * @return the encoded onion, base32 chars
 	 */
-	String encodeOnion(byte[] publicKey);
+	String encodeOnionAddress(byte[] publicKey);
 
 }

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

@@ -33,18 +33,11 @@ import java.util.List;
 import java.util.Map;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
 
 /**
  * Encapsulates the database implementation and exposes high-level operations
  * to other components.
- * <p>
- * With the exception of the {@link #open(SecretKey, MigrationListener)} and
- * {@link #close()} methods, which must not be called concurrently, the
- * database can be accessed from any thread. See {@link TransactionManager}
- * for locking behaviour.
  */
-@ThreadSafe
 @NotNullByDefault
 public interface DatabaseComponent extends TransactionManager {
 
@@ -126,11 +119,16 @@ public interface DatabaseComponent extends TransactionManager {
 			TransportKeys k) throws DbException;
 
 	/**
-	 * Returns true if there are any acks to send to the given contact.
+	 * Returns true if there are any acks or messages to send to the given
+	 * contact over a transport with the given maximum latency.
 	 * <p/>
 	 * Read-only.
+	 *
+	 * @param eager True if messages that are not yet due for retransmission
+	 * should be included
 	 */
-	boolean containsAcksToSend(Transaction txn, ContactId c) throws DbException;
+	boolean containsAnythingToSend(Transaction txn, ContactId c,
+			long maxLatency, boolean eager) throws DbException;
 
 	/**
 	 * Returns true if the database contains the given contact for the given
@@ -156,18 +154,6 @@ public interface DatabaseComponent extends TransactionManager {
 	 */
 	boolean containsIdentity(Transaction txn, AuthorId a) throws DbException;
 
-	/**
-	 * Returns true if there are any messages to send to the given contact
-	 * over a transport with the given maximum latency.
-	 * <p/>
-	 * Read-only.
-	 *
-	 * @param eager True if messages that are not yet due for retransmission
-	 * should be included
-	 */
-	boolean containsMessagesToSend(Transaction txn, ContactId c,
-			long maxLatency, boolean eager) throws DbException;
-
 	/**
 	 * Returns true if the database contains the given pending contact.
 	 * <p/>
@@ -207,15 +193,26 @@ public interface DatabaseComponent extends TransactionManager {
 			throws DbException;
 
 	/**
-	 * Returns a batch of messages for the given contact, for transmission over
+	 * Returns a batch of messages for the given contact, with a total length
-	 * a transport with the given maximum latency. The total length of the
+	 * less than or equal to the given length, for transmission over a
-	 * messages, including record headers, will be no more than the given
+	 * transport with the given maximum latency. Returns null if there are no
-	 * capacity. Returns null if there are no sendable messages that would fit
+	 * sendable messages that fit in the given length.
-	 * in the given capacity.
 	 */
 	@Nullable
 	Collection<Message> generateBatch(Transaction txn, ContactId c,
-			long capacity, long maxLatency) throws DbException;
+			int maxLength, long maxLatency) throws DbException;
+
+	/**
+	 * Returns a batch of messages for the given contact containing the
+	 * messages with the given IDs, for transmission over a transport with
+	 * the given maximum latency.
+	 * <p/>
+	 * If any of the given messages are not in the database or are not visible
+	 * to the contact, they are omitted from the batch without throwing an
+	 * exception.
+	 */
+	Collection<Message> generateBatch(Transaction txn, ContactId c,
+			Collection<MessageId> ids, long maxLatency) throws DbException;
 
 	/**
 	 * Returns an offer for the given contact for transmission over a
@@ -235,16 +232,15 @@ public interface DatabaseComponent extends TransactionManager {
 			throws DbException;
 
 	/**
-	 * Returns a batch of messages for the given contact, for transmission over
+	 * Returns a batch of messages for the given contact, with a total length
-	 * a transport with the given maximum latency. Only messages that have been
+	 * less than or equal to the given length, for transmission over a
-	 * requested by the contact are returned. The total length of the messages,
+	 * transport with the given maximum latency. Only messages that have been
-	 * including record headers, will be no more than the given capacity.
+	 * requested by the contact are returned. Returns null if there are no
-	 * Returns null if there are no sendable messages that have been requested
+	 * sendable messages that fit in the given length.
-	 * by the contact and would fit in the given capacity.
 	 */
 	@Nullable
 	Collection<Message> generateRequestedBatch(Transaction txn, ContactId c,
-			long capacity, long maxLatency) throws DbException;
+			int maxLength, long maxLatency) throws DbException;
 
 	/**
 	 * Returns the contact with the given ID.
@@ -283,13 +279,6 @@ public interface DatabaseComponent extends TransactionManager {
 	 */
 	Group getGroup(Transaction txn, GroupId g) throws DbException;
 
-	/**
-	 * Returns the ID of the group containing the given message.
-	 * <p/>
-	 * Read-only.
-	 */
-	GroupId getGroupId(Transaction txn, MessageId m) throws DbException;
-
 	/**
 	 * Returns the metadata for the given group.
 	 * <p/>
@@ -355,30 +344,6 @@ public interface DatabaseComponent extends TransactionManager {
 	Collection<MessageId> getMessageIds(Transaction txn, GroupId g,
 			Metadata query) throws DbException;
 
-	/**
-	 * Returns the IDs of all messages received from the given contact that
-	 * need to be acknowledged.
-	 * <p/>
-	 * Read-only.
-	 */
-	Collection<MessageId> getMessagesToAck(Transaction txn, ContactId c)
-			throws DbException;
-
-	/**
-	 * Returns the IDs of some messages that are eligible to be sent to the
-	 * given contact over a transport with the given maximum latency. The total
-	 * length of the messages including record headers will be no more than the
-	 * given capacity.
-	 * <p/>
-	 * Unlike {@link #getUnackedMessagesToSend(Transaction, ContactId)} this
-	 * method does not return messages that have already been sent unless they
-	 * are due for retransmission.
-	 * <p/>
-	 * Read-only.
-	 */
-	Collection<MessageId> getMessagesToSend(Transaction txn, ContactId c,
-			long capacity, long maxLatency) throws DbException;
-
 	/**
 	 * Returns the IDs of any messages that need to be validated.
 	 * <p/>
@@ -495,38 +460,21 @@ public interface DatabaseComponent extends TransactionManager {
 	MessageStatus getMessageStatus(Transaction txn, ContactId c, MessageId m)
 			throws DbException;
 
-	/**
-	 * Returns the message with the given ID for transmission to the given
-	 * contact over a transport with the given maximum latency. Returns null
-	 * if the message is no longer visible to the contact.
-	 * <p/>
-	 * Read-only if {@code markAsSent} is false.
-	 *
-	 * @param markAsSent True if the message should be marked as sent.
-	 * If false it can be marked as sent by calling
-	 * {@link #setMessagesSent(Transaction, ContactId, Collection, long)}.
-	 */
-	@Nullable
-	Message getMessageToSend(Transaction txn, ContactId c, MessageId m,
-			long maxLatency, boolean markAsSent) throws DbException;
-
 	/**
 	 * Returns the IDs of all messages that are eligible to be sent to the
-	 * given contact.
+	 * given contact, together with their raw lengths. This may include
-	 * <p>
+	 * messages that have already been sent and are not yet due for
-	 * Unlike {@link #getMessagesToSend(Transaction, ContactId, long, long)}
+	 * retransmission.
-	 * this method may return messages that have already been sent and are
-	 * not yet due for retransmission.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getUnackedMessagesToSend(Transaction txn,
+	Map<MessageId, Integer> getUnackedMessagesToSend(Transaction txn,
 			ContactId c) throws DbException;
 
 	/**
-	 * Resets the transmission count, expiry time and max latency of all messages
+	 * Reset the transmission count, expiry time and ETA of all messages that
-	 * that are eligible to be sent to the given contact. This includes messages
+	 * are eligible to be sent to the given contact. This includes messages that
-	 * that have already been sent and are not yet due for retransmission.
+	 * have already been sent and are not yet due for retransmission.
 	 */
 	void resetUnackedMessagesToSend(Transaction txn, ContactId c)
 			throws DbException;
@@ -550,18 +498,15 @@ public interface DatabaseComponent extends TransactionManager {
 	 */
 	long getNextCleanupDeadline(Transaction txn) throws DbException;
 
-	/**
+	/*
 	 * Returns the next time (in milliseconds since the Unix epoch) when a
-	 * message is due to be sent to the given contact over a transport with
+	 * message is due to be sent to the given contact. The returned value may
-	 * the given latency.
+	 * be zero if a message is due to be sent immediately, or Long.MAX_VALUE if
-	 * <p>
+	 * no messages are scheduled to be sent.
-	 * The returned value may be zero if a message is due to be sent
-	 * immediately, or Long.MAX_VALUE if no messages are scheduled to be sent.
 	 * <p/>
 	 * Read-only.
 	 */
-	long getNextSendTime(Transaction txn, ContactId c, long maxLatency)
+	long getNextSendTime(Transaction txn, ContactId c) throws DbException;
-			throws DbException;
 
 	/**
 	 * Returns the pending contact with the given ID.
@@ -703,13 +648,6 @@ public interface DatabaseComponent extends TransactionManager {
 	void removeTransportKeys(Transaction txn, TransportId t, KeySetId k)
 			throws DbException;
 
-	/**
-	 * Records an ack for the given messages as having been sent to the given
-	 * contact.
-	 */
-	void setAckSent(Transaction txn, ContactId c, Collection<MessageId> acked)
-			throws DbException;
-
 	/**
 	 * Sets the cleanup timer duration for the given message. This does not
 	 * start the message's cleanup timer.
@@ -756,13 +694,6 @@ public interface DatabaseComponent extends TransactionManager {
 	void setMessageState(Transaction txn, MessageId m, MessageState state)
 			throws DbException;
 
-	/**
-	 * Records the given messages as having been sent to the given contact
-	 * over a transport with the given maximum latency.
-	 */
-	void setMessagesSent(Transaction txn, ContactId c,
-			Collection<MessageId> sent, long maxLatency) throws DbException;
-
 	/**
 	 * Adds dependencies for a message
 	 */

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

@@ -18,10 +18,6 @@ import static java.lang.annotation.RetentionPolicy.RUNTIME;
  * submitted, tasks are not run concurrently, and submitting a task will never
  * block. Tasks must not run indefinitely. Tasks submitted during shutdown are
  * discarded.
- * <p>
- * It is not mandatory to use this executor for database tasks. The database
- * can be accessed from any thread, but this executor's guarantee that tasks
- * are run in the order they're submitted may be useful in some cases.
  */
 @Qualifier
 @Target({FIELD, METHOD, PARAMETER})

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

@@ -45,9 +45,6 @@ public class Transaction {
 	/**
 	 * Attaches an event to be broadcast when the transaction has been
 	 * committed. The event will be broadcast on the {@link EventExecutor}.
-	 * Events and {@link #attach(Runnable) tasks} are submitted to the
-	 * {@link EventExecutor} in the order they were attached to the
-	 * transaction.
 	 */
 	public void attach(Event e) {
 		if (actions == null) actions = new ArrayList<>();
@@ -57,9 +54,6 @@ public class Transaction {
 	/**
 	 * Attaches a task to be executed when the transaction has been
 	 * committed. The task will be run on the {@link EventExecutor}.
-	 * {@link #attach(Event) Events} and tasks are submitted to the
-	 * {@link EventExecutor} in the order they were attached to the
-	 * transaction.
 	 */
 	public void attach(Runnable r) {
 		if (actions == null) actions = new ArrayList<>();

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

@@ -1,95 +1,51 @@
 package org.briarproject.bramble.api.db;
 
-import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
 
-/**
- * An interface for managing database transactions.
- * <p>
- * Read-only transactions may access the database concurrently. Read-write
- * transactions access the database exclusively, so starting a read-only or
- * read-write transaction will block until there are no read-write
- * transactions in progress.
- * <p>
- * Failing to {@link #endTransaction(Transaction) end} a transaction will
- * prevent other callers from accessing the database, so it is recommended to
- * use the {@link #transaction(boolean, DbRunnable)},
- * {@link #transactionWithResult(boolean, DbCallable)} and
- * {@link #transactionWithNullableResult(boolean, NullableDbCallable)} methods
- * where possible, which handle committing or aborting the transaction on the
- * caller's behalf.
- * <p>
- * Transactions are not reentrant, i.e. it is not permitted to start a
- * transaction on a thread that already has a transaction in progress.
- */
-@ThreadSafe
 @NotNullByDefault
 public interface TransactionManager {
 
 	/**
-	 * Starts a new transaction and returns an object representing it. This
+	 * Starts a new transaction and returns an object representing it.
-	 * method acquires the database lock, which is held until
+	 * <p/>
-	 * {@link #endTransaction(Transaction)} is called.
+	 * This method acquires locks, so it must not be called while holding a
+	 * lock.
 	 *
-	 * @param readOnly True if the transaction will only be used for reading,
+	 * @param readOnly true if the transaction will only be used for reading.
-	 * in which case the database lock can be shared with other read-only
-	 * transactions.
 	 */
 	Transaction startTransaction(boolean readOnly) throws DbException;
 
 	/**
 	 * Commits a transaction to the database.
-	 * {@link #endTransaction(Transaction)} must be called to release the
-	 * database lock.
 	 */
 	void commitTransaction(Transaction txn) throws DbException;
 
 	/**
-	 * Ends a transaction. If the transaction has not been committed by
+	 * Ends a transaction. If the transaction has not been committed,
-	 * calling {@link #commitTransaction(Transaction)}, it is aborted and the
+	 * it will be aborted. If the transaction has been committed,
-	 * database lock is released.
+	 * any events attached to the transaction are broadcast.
-	 * <p>
+	 * The database lock will be released in either case.
-	 * If the transaction has been committed, any
-	 * {@link Transaction#attach events} attached to the transaction are
-	 * broadcast and any {@link Transaction#attach(Runnable) tasks} attached
-	 * to the transaction are submitted to the {@link EventExecutor}. The
-	 * database lock is then released.
 	 */
 	void endTransaction(Transaction txn);
 
 	/**
-	 * Runs the given task within a transaction. The database lock is held
+	 * Runs the given task within a transaction.
-	 * while running the task.
-	 *
-	 * @param readOnly True if the transaction will only be used for reading,
-	 * in which case the database lock can be shared with other read-only
-	 * transactions.
 	 */
 	<E extends Exception> void transaction(boolean readOnly,
 			DbRunnable<E> task) throws DbException, E;
 
 	/**
 	 * Runs the given task within a transaction and returns the result of the
-	 * task. The database lock is held while running the task.
+	 * task.
-	 *
-	 * @param readOnly True if the transaction will only be used for reading,
-	 * in which case the database lock can be shared with other read-only
-	 * transactions.
 	 */
 	<R, E extends Exception> R transactionWithResult(boolean readOnly,
 			DbCallable<R, E> task) throws DbException, E;
 
 	/**
 	 * Runs the given task within a transaction and returns the result of the
-	 * task, which may be null. The database lock is held while running the
+	 * task, which may be null.
-	 * task.
-	 *
-	 * @param readOnly True if the transaction will only be used for reading,
-	 * in which case the database lock can be shared with other read-only
-	 * transactions.
 	 */
 	@Nullable
 	<R, E extends Exception> R transactionWithNullableResult(boolean readOnly,

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

@@ -21,4 +21,9 @@ public class AuthorId extends UniqueId {
 	public AuthorId(byte[] id) {
 		super(id);
 	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof AuthorId && super.equals(o);
+	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/lifecycle/LifecycleManager.java

@@ -37,14 +37,8 @@ public interface LifecycleManager {
 	 */
 	enum LifecycleState {
 
-		CREATED,
+		STARTING, MIGRATING_DATABASE, COMPACTING_DATABASE, STARTING_SERVICES,
-		STARTING,
+		RUNNING, STOPPING;
-		MIGRATING_DATABASE,
-		COMPACTING_DATABASE,
-		STARTING_SERVICES,
-		RUNNING,
-		STOPPING,
-		STOPPED;
 
 		public boolean isAfter(LifecycleState state) {
 			return ordinal() > state.ordinal();

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/InvalidMailboxIdException.java

@@ -1,8 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-@NotNullByDefault
-public class InvalidMailboxIdException extends Exception {
-
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxAuthToken.java

@@ -1,24 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
-
-@ThreadSafe
-@NotNullByDefault
-public class MailboxAuthToken extends MailboxId {
-	public MailboxAuthToken(byte[] id) {
-		super(id);
-	}
-
-	/**
-	 * Creates a {@link MailboxAuthToken} from the given string.
-	 *
-	 * @throws InvalidMailboxIdException if token is not valid.
-	 */
-	public static MailboxAuthToken fromString(@Nullable String token)
-			throws InvalidMailboxIdException {
-		return new MailboxAuthToken(bytesFromString(token));
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxConstants.java

@@ -1,73 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.plugin.TransportId;
-
-import java.util.List;
-
-import static java.util.Collections.singletonList;
-import static java.util.concurrent.TimeUnit.DAYS;
-import static java.util.concurrent.TimeUnit.HOURS;
-import static org.briarproject.bramble.api.transport.TransportConstants.MAX_FRAME_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_LENGTH;
-import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
-
-public interface MailboxConstants {
-
-	/**
-	 * The transport ID of the mailbox plugin.
-	 */
-	TransportId ID = new TransportId("org.briarproject.bramble.mailbox");
-
-	/**
-	 * Mailbox API versions that we support as a client. This is reported to our
-	 * contacts by {@link MailboxUpdateManager}.
-	 */
-	List<MailboxVersion> CLIENT_SUPPORTS = singletonList(
-			new MailboxVersion(1, 0));
-
-	/**
-	 * The constant returned by
-	 * {@link MailboxHelper#getHighestCommonMajorVersion(List, List)}
-	 * when the server is too old to support our major version.
-	 */
-	int API_SERVER_TOO_OLD = -1;
-
-	/**
-	 * The constant returned by
-	 * {@link MailboxHelper#getHighestCommonMajorVersion(List, List)}
-	 * when we as a client are too old to support the server's major version.
-	 */
-	int API_CLIENT_TOO_OLD = -2;
-
-	/**
-	 * The maximum length of a file that can be uploaded to or downloaded from
-	 * a mailbox.
-	 */
-	int MAX_FILE_BYTES = 1024 * 1024;
-
-	/**
-	 * The maximum length of the plaintext payload of a file, such that the
-	 * ciphertext is no more than {@link #MAX_FILE_BYTES}.
-	 */
-	int MAX_FILE_PAYLOAD_BYTES =
-			(MAX_FILE_BYTES - TAG_LENGTH - STREAM_HEADER_LENGTH)
-					/ MAX_FRAME_LENGTH * MAX_PAYLOAD_LENGTH;
-
-	/**
-	 * The number of connection failures
-	 * that indicate a problem with the mailbox.
-	 */
-	int PROBLEM_NUM_CONNECTION_FAILURES = 5;
-
-	/**
-	 * The time in milliseconds since the last connection success
-	 * that need to pass to indicates a problem with the mailbox.
-	 */
-	long PROBLEM_MS_SINCE_LAST_SUCCESS = HOURS.toMillis(1);
-
-	/**
-	 * The maximum latency of the mailbox transport in milliseconds.
-	 */
-	long MAX_LATENCY = DAYS.toMillis(14);
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxDirectory.java

@@ -1,22 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import java.io.File;
-import java.lang.annotation.Retention;
-import java.lang.annotation.Target;
-
-import javax.inject.Qualifier;
-
-import static java.lang.annotation.ElementType.FIELD;
-import static java.lang.annotation.ElementType.METHOD;
-import static java.lang.annotation.ElementType.PARAMETER;
-import static java.lang.annotation.RetentionPolicy.RUNTIME;
-
-/**
- * Annotation for injecting the {@link File directory} where the Mailbox plugin
- * should store its state.
- */
-@Qualifier
-@Target({FIELD, METHOD, PARAMETER})
-@Retention(RUNTIME)
-public @interface MailboxDirectory {
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxFileId.java

@@ -1,24 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
-
-@ThreadSafe
-@NotNullByDefault
-public class MailboxFileId extends MailboxId {
-	public MailboxFileId(byte[] id) {
-		super(id);
-	}
-
-	/**
-	 * Creates a {@link MailboxFileId} from the given string.
-	 *
-	 * @throws IllegalArgumentException if token is not valid.
-	 */
-	public static MailboxFileId fromString(@Nullable String token)
-			throws InvalidMailboxIdException {
-		return new MailboxFileId(bytesFromString(token));
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxFolderId.java

@@ -1,24 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
-
-@ThreadSafe
-@NotNullByDefault
-public class MailboxFolderId extends MailboxId {
-	public MailboxFolderId(byte[] id) {
-		super(id);
-	}
-
-	/**
-	 * Creates a {@link MailboxFolderId} from the given string.
-	 *
-	 * @throws IllegalArgumentException if token is not valid.
-	 */
-	public static MailboxFolderId fromString(@Nullable String token)
-			throws InvalidMailboxIdException {
-		return new MailboxFolderId(bytesFromString(token));
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxHelper.java

@@ -1,47 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.List;
-import java.util.TreeSet;
-
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.API_CLIENT_TOO_OLD;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.API_SERVER_TOO_OLD;
-
-@NotNullByDefault
-public class MailboxHelper {
-
-	/**
-	 * Returns the highest major version that both client and server support
-	 * or {@link MailboxConstants#API_SERVER_TOO_OLD} if the server is too old
-	 * or {@link MailboxConstants#API_CLIENT_TOO_OLD} if the client is too old.
-	 */
-	public static int getHighestCommonMajorVersion(
-			List<MailboxVersion> client, List<MailboxVersion> server) {
-		TreeSet<Integer> clientVersions = new TreeSet<>();
-		for (MailboxVersion version : client) {
-			clientVersions.add(version.getMajor());
-		}
-		TreeSet<Integer> serverVersions = new TreeSet<>();
-		for (MailboxVersion version : server) {
-			serverVersions.add(version.getMajor());
-		}
-		for (int clientVersion : clientVersions.descendingSet()) {
-			if (serverVersions.contains(clientVersion)) return clientVersion;
-		}
-		if (clientVersions.last() < serverVersions.last()) {
-			return API_CLIENT_TOO_OLD;
-		}
-		return API_SERVER_TOO_OLD;
-	}
-
-	/**
-	 * Returns true if a client and server with the given API versions can
-	 * communicate with each other (ie, have any major API versions in common).
-	 */
-	public static boolean isClientCompatibleWithServer(
-			List<MailboxVersion> client, List<MailboxVersion> server) {
-		int common = getHighestCommonMajorVersion(client, server);
-		return common != API_CLIENT_TOO_OLD && common != API_SERVER_TOO_OLD;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxId.java

@@ -1,50 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import com.fasterxml.jackson.annotation.JsonValue;
-
-import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.UniqueId;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.Locale;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.ThreadSafe;
-
-import static org.briarproject.bramble.util.StringUtils.fromHexString;
-import static org.briarproject.bramble.util.StringUtils.toHexString;
-
-@ThreadSafe
-@NotNullByDefault
-public abstract class MailboxId extends UniqueId {
-	MailboxId(byte[] id) {
-		super(id);
-	}
-
-	/**
-	 * Returns valid {@link MailboxId} bytes from the given string.
-	 *
-	 * @throws InvalidMailboxIdException if token is not valid.
-	 */
-	static byte[] bytesFromString(@Nullable String token)
-			throws InvalidMailboxIdException {
-		if (token == null || token.length() != 64) {
-			throw new InvalidMailboxIdException();
-		}
-		try {
-			return fromHexString(token);
-		} catch (FormatException e) {
-			throw new InvalidMailboxIdException();
-		}
-	}
-
-	/**
-	 * Returns the string representation expected by the mailbox API.
-	 * Also used for serialization.
-	 */
-	@Override
-	@JsonValue
-	public String toString() {
-		return toHexString(getBytes()).toLowerCase(Locale.US);
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxManager.java

@@ -1,56 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.mailbox.event.OwnMailboxConnectionStatusEvent;
-
-import javax.annotation.Nullable;
-
-public interface MailboxManager {
-
-	/**
-	 * @return true if a mailbox is already paired.
-	 */
-	boolean isPaired(Transaction txn) throws DbException;
-
-	/**
-	 * @return the current status of the mailbox.
-	 */
-	MailboxStatus getMailboxStatus(Transaction txn) throws DbException;
-
-	/**
-	 * Returns the currently running pairing task,
-	 * or null if no pairing task is running.
-	 */
-	@Nullable
-	MailboxPairingTask getCurrentPairingTask();
-
-	/**
-	 * Starts and returns a pairing task. If a pairing task is already running,
-	 * it will be returned and the argument will be ignored.
-	 *
-	 * @param qrCodePayload The ISO-8859-1 encoded bytes of the mailbox QR code.
-	 */
-	MailboxPairingTask startPairingTask(String qrCodePayload);
-
-	/**
-	 * Can be used by the UI to test the mailbox connection.
-	 *
-	 * @return true (success) or false (error).
-	 * A {@link OwnMailboxConnectionStatusEvent} might be broadcast with a new
-	 * {@link MailboxStatus}.
-	 */
-	boolean checkConnection();
-
-	/**
-	 * Unpairs the owner's mailbox and tries to wipe it.
-	 * As this makes a network call, it should be run on the {@link IoExecutor}.
-	 *
-	 * @return true if we could wipe the mailbox, false if we couldn't.
-	 * It is advised to inform the user to wipe the mailbox themselves,
-	 * if we failed to wipe it.
-	 */
-	@IoExecutor
-	boolean unPair() throws DbException;
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxPairingState.java

@@ -1,25 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-public abstract class MailboxPairingState {
-
-	public static class QrCodeReceived extends MailboxPairingState {
-	}
-
-	public static class Pairing extends MailboxPairingState {
-	}
-
-	public static class Paired extends MailboxPairingState {
-	}
-
-	public static class InvalidQrCode extends MailboxPairingState {
-	}
-
-	public static class MailboxAlreadyPaired extends MailboxPairingState {
-	}
-
-	public static class ConnectionError extends MailboxPairingState {
-	}
-
-	public static class UnexpectedError extends MailboxPairingState {
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxPairingTask.java

@@ -1,21 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.Consumer;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-@NotNullByDefault
-public interface MailboxPairingTask extends Runnable {
-
-	/**
-	 * Adds an observer to the task. The observer will be notified on the
-	 * event thread of the current state of the task and any subsequent state
-	 * changes.
-	 */
-	void addObserver(Consumer<MailboxPairingState> observer);
-
-	/**
-	 * Removes an observer from the task.
-	 */
-	void removeObserver(Consumer<MailboxPairingState> observer);
-
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxProperties.java

@@ -1,98 +1,32 @@
 package org.briarproject.bramble.api.mailbox;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.NullSafety;
 
-import java.util.List;
-
-import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
 @Immutable
 @NotNullByDefault
 public class MailboxProperties {
 
-	private final String onion;
+	private final String onionAddress, authToken;
-	private final MailboxAuthToken authToken;
 	private final boolean owner;
-	private final List<MailboxVersion> serverSupports;
-	@Nullable
-	private final MailboxFolderId inboxId; // Null for own mailbox
-	@Nullable
-	private final MailboxFolderId outboxId; // Null for own mailbox
 
-	/**
+	public MailboxProperties(String onionAddress, String authToken,
-	 * Constructor for properties used by the mailbox's owner.
+			boolean owner) {
-	 */
+		this.onionAddress = onionAddress;
-	public MailboxProperties(String onion, MailboxAuthToken authToken,
-			List<MailboxVersion> serverSupports) {
-		this.onion = onion;
 		this.authToken = authToken;
-		this.owner = true;
+		this.owner = owner;
-		this.serverSupports = serverSupports;
-		this.inboxId = null;
-		this.outboxId = null;
 	}
 
-	/**
+	public String getOnionAddress() {
-	 * Constructor for properties used by a contact of the mailbox's owner.
+		return onionAddress;
-	 */
-	public MailboxProperties(String onion, MailboxAuthToken authToken,
-			List<MailboxVersion> serverSupports, MailboxFolderId inboxId,
-			MailboxFolderId outboxId) {
-		this.onion = onion;
-		this.authToken = authToken;
-		this.owner = false;
-		this.serverSupports = serverSupports;
-		this.inboxId = inboxId;
-		this.outboxId = outboxId;
 	}
 
-	/**
+	public String getAuthToken() {
-	 * Returns the onion address of the mailbox, excluding the .onion suffix.
-	 */
-	public String getOnion() {
-		return onion;
-	}
-
-	public MailboxAuthToken getAuthToken() {
 		return authToken;
 	}
 
 	public boolean isOwner() {
 		return owner;
 	}
-
-	public List<MailboxVersion> getServerSupports() {
-		return serverSupports;
-	}
-
-	@Nullable
-	public MailboxFolderId getInboxId() {
-		return inboxId;
-	}
-
-	@Nullable
-	public MailboxFolderId getOutboxId() {
-		return outboxId;
-	}
-
-	@Override
-	public boolean equals(Object o) {
-		if (o instanceof MailboxProperties) {
-			MailboxProperties m = (MailboxProperties) o;
-			return owner == m.owner &&
-					onion.equals(m.onion) &&
-					authToken.equals(m.authToken) &&
-					NullSafety.equals(inboxId, m.inboxId) &&
-					NullSafety.equals(outboxId, m.outboxId) &&
-					serverSupports.equals(m.serverSupports);
-		}
-		return false;
-	}
-
-	@Override
-	public int hashCode() {
-		return authToken.hashCode();
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxSettingsManager.java

@@ -1,26 +1,15 @@
 package org.briarproject.bramble.api.mailbox;
 
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
-import java.util.List;
-
 import javax.annotation.Nullable;
 
 @NotNullByDefault
 public interface MailboxSettingsManager {
 
-	/**
-	 * Registers a hook to be called when a mailbox has been paired or unpaired.
-	 * This method should be called before
-	 * {@link LifecycleManager#startServices(SecretKey)}.
-	 */
-	void registerMailboxHook(MailboxHook hook);
-
 	@Nullable
 	MailboxProperties getOwnMailboxProperties(Transaction txn)
 			throws DbException;
@@ -28,12 +17,10 @@ public interface MailboxSettingsManager {
 	void setOwnMailboxProperties(Transaction txn, MailboxProperties p)
 			throws DbException;
 
-	void removeOwnMailboxProperties(Transaction txn) throws DbException;
-
 	MailboxStatus getOwnMailboxStatus(Transaction txn) throws DbException;
 
-	void recordSuccessfulConnection(Transaction txn, long now,
+	void recordSuccessfulConnection(Transaction txn, long now)
-			List<MailboxVersion> versions) throws DbException;
+			throws DbException;
 
 	void recordFailedConnectionAttempt(Transaction txn, long now)
 			throws DbException;
@@ -43,31 +30,4 @@ public interface MailboxSettingsManager {
 
 	@Nullable
 	String getPendingUpload(Transaction txn, ContactId id) throws DbException;
-
-	interface MailboxHook {
-		/**
-		 * Called when Briar is paired with a mailbox.
-		 *
-		 * @param txn A read-write transaction
-		 */
-		void mailboxPaired(Transaction txn, MailboxProperties p)
-				throws DbException;
-
-		/**
-		 * Called when the mailbox is unpaired.
-		 *
-		 * @param txn A read-write transaction
-		 */
-		void mailboxUnpaired(Transaction txn) throws DbException;
-
-		/**
-		 * Called when we receive our mailbox's server-supported API versions.
-		 * This happens whenever we successfully check the connectivity of
-		 * our mailbox, so this hook may be called frequently.
-		 *
-		 * @param txn A read-write transaction
-		 */
-		void serverSupportedVersionsReceived(Transaction txn,
-				List<MailboxVersion> serverSupports) throws DbException;
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxStatus.java

@@ -2,30 +2,20 @@ package org.briarproject.bramble.api.mailbox;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
-import java.util.List;
-
 import javax.annotation.concurrent.Immutable;
 
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.CLIENT_SUPPORTS;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.PROBLEM_MS_SINCE_LAST_SUCCESS;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.PROBLEM_NUM_CONNECTION_FAILURES;
-import static org.briarproject.bramble.api.mailbox.MailboxHelper.getHighestCommonMajorVersion;
-
 @Immutable
 @NotNullByDefault
 public class MailboxStatus {
 
 	private final long lastAttempt, lastSuccess;
 	private final int attemptsSinceSuccess;
-	private final List<MailboxVersion> serverSupports;
 
 	public MailboxStatus(long lastAttempt, long lastSuccess,
-			int attemptsSinceSuccess,
+			int attemptsSinceSuccess) {
-			List<MailboxVersion> serverSupports) {
 		this.lastAttempt = lastAttempt;
 		this.lastSuccess = lastSuccess;
 		this.attemptsSinceSuccess = attemptsSinceSuccess;
-		this.serverSupports = serverSupports;
 	}
 
 	/**
@@ -66,28 +56,4 @@ public class MailboxStatus {
 	public int getAttemptsSinceSuccess() {
 		return attemptsSinceSuccess;
 	}
-
-	/**
-	 * Returns the mailbox's supported API versions.
-	 */
-	public List<MailboxVersion> getServerSupports() {
-		return serverSupports;
-	}
-
-	/**
-	 * @return true if this status indicates a problem with the mailbox.
-	 */
-	public boolean hasProblem(long now) {
-		return attemptsSinceSuccess >= PROBLEM_NUM_CONNECTION_FAILURES &&
-				(now - lastSuccess) >= PROBLEM_MS_SINCE_LAST_SUCCESS;
-	}
-
-	/**
-	 * @return a positive integer if the mailbox is compatible. Same result as
-	 * {@link MailboxHelper#getHighestCommonMajorVersion(List, List)}.
-	 */
-	public int getMailboxCompatibility() {
-		return getHighestCommonMajorVersion(CLIENT_SUPPORTS, serverSupports);
-	}
-
 }

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdate.java

@@ -1,31 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.List;
-
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
-public class MailboxUpdate {
-	private final boolean hasMailbox;
-	private final List<MailboxVersion> clientSupports;
-
-	public MailboxUpdate(List<MailboxVersion> clientSupports) {
-		this(clientSupports, false);
-	}
-
-	MailboxUpdate(List<MailboxVersion> clientSupports, boolean hasMailbox) {
-		this.clientSupports = clientSupports;
-		this.hasMailbox = hasMailbox;
-	}
-
-	public List<MailboxVersion> getClientSupports() {
-		return clientSupports;
-	}
-
-	public boolean hasMailbox() {
-		return hasMailbox;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdateManager.java

@@ -1,111 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.ClientId;
-
-import javax.annotation.Nullable;
-
-@NotNullByDefault
-public interface MailboxUpdateManager {
-
-	/**
-	 * The unique ID of the mailbox update (properties) client.
-	 */
-	ClientId CLIENT_ID =
-			new ClientId("org.briarproject.bramble.mailbox.properties");
-
-	/**
-	 * The current major version of the mailbox update (properties) client.
-	 */
-	int MAJOR_VERSION = 2;
-
-	/**
-	 * The current minor version of the mailbox update (properties) client.
-	 */
-	int MINOR_VERSION = 0;
-
-	/**
-	 * The number of properties required for an update message with a mailbox.
-	 * <p>
-	 * The required properties are {@link #PROP_KEY_ONION},
-	 * {@link #PROP_KEY_AUTHTOKEN}, {@link #PROP_KEY_INBOXID} and
-	 * {@link #PROP_KEY_OUTBOXID}.
-	 */
-	int PROP_COUNT = 4;
-
-	/**
-	 * The onion address of the mailbox, excluding the .onion suffix.
-	 */
-	String PROP_KEY_ONION = "onion";
-
-	/**
-	 * A bearer token for accessing the mailbox (64 hex digits).
-	 */
-	String PROP_KEY_AUTHTOKEN = "authToken";
-
-	/**
-	 * A folder ID for downloading messages (64 hex digits).
-	 */
-	String PROP_KEY_INBOXID = "inboxId";
-
-	/**
-	 * A folder ID for uploading messages (64 hex digits).
-	 */
-	String PROP_KEY_OUTBOXID = "outboxId";
-
-	/**
-	 * Length of the {@link #PROP_KEY_ONION} property.
-	 */
-	int PROP_ONION_LENGTH = 56;
-
-	/**
-	 * Message metadata key for the version number of a local or remote update,
-	 * as a BDF long.
-	 */
-	String MSG_KEY_VERSION = "version";
-
-	/**
-	 * Message metadata key for whether an update is local or remote, as a BDF
-	 * boolean.
-	 */
-	String MSG_KEY_LOCAL = "local";
-
-	/**
-	 * Key in the client's local group for storing the clientSupports list that
-	 * was last sent out.
-	 */
-	String GROUP_KEY_SENT_CLIENT_SUPPORTS = "sentClientSupports";
-
-	/**
-	 * Key in the client's local group for storing the serverSupports list that
-	 * was last sent out, if any.
-	 */
-	String GROUP_KEY_SENT_SERVER_SUPPORTS = "sentServerSupports";
-
-	/**
-	 * Returns the latest {@link MailboxUpdate} sent to the given contact.
-	 * <p>
-	 * If we have our own mailbox then the update will be a
-	 * {@link MailboxUpdateWithMailbox} containing the
-	 * {@link MailboxProperties} the contact should use for communicating with
-	 * our mailbox.
-	 */
-	MailboxUpdate getLocalUpdate(Transaction txn, ContactId c)
-			throws DbException;
-
-	/**
-	 * Returns the latest {@link MailboxUpdate} received from the given
-	 * contact, or null if no update has been received.
-	 * <p>
-	 * If the contact has a mailbox then the update will be a
-	 * {@link MailboxUpdateWithMailbox} containing the
-	 * {@link MailboxProperties} we should use for communicating with the
-	 * contact's mailbox.
-	 */
-	@Nullable
-	MailboxUpdate getRemoteUpdate(Transaction txn, ContactId c)
-			throws DbException;
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxUpdateWithMailbox.java

@@ -1,30 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.List;
-
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
-public class MailboxUpdateWithMailbox extends MailboxUpdate {
-
-	private final MailboxProperties properties;
-
-	public MailboxUpdateWithMailbox(List<MailboxVersion> clientSupports,
-			MailboxProperties properties) {
-		super(clientSupports, true);
-		if (properties.isOwner()) throw new IllegalArgumentException();
-		this.properties = properties;
-	}
-
-	public MailboxUpdateWithMailbox(MailboxUpdateWithMailbox o,
-			List<MailboxVersion> newClientSupports) {
-		this(newClientSupports, o.getMailboxProperties());
-	}
-
-	public MailboxProperties getMailboxProperties() {
-		return properties;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/MailboxVersion.java

@@ -1,44 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-@Immutable
-@NotNullByDefault
-public class MailboxVersion implements Comparable<MailboxVersion> {
-
-	private final int major;
-	private final int minor;
-
-	public MailboxVersion(int major, int minor) {
-		this.major = major;
-		this.minor = minor;
-	}
-
-	public int getMajor() {
-		return major;
-	}
-
-	public int getMinor() {
-		return minor;
-	}
-
-	@Override
-	public boolean equals(Object o) {
-		if (o instanceof MailboxVersion) {
-			MailboxVersion v = (MailboxVersion) o;
-			return major == v.major && minor == v.minor;
-		}
-		return false;
-	}
-
-	@Override
-	public int compareTo(MailboxVersion v) {
-		int c = major - v.major;
-		if (c != 0) {
-			return c;
-		}
-		return minor - v.minor;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/event/MailboxPairedEvent.java

@@ -1,36 +0,0 @@
-package org.briarproject.bramble.api.mailbox.event;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateWithMailbox;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.Map;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when a mailbox is paired.
- */
-@Immutable
-@NotNullByDefault
-public class MailboxPairedEvent extends Event {
-
-	private final MailboxProperties properties;
-	private final Map<ContactId, MailboxUpdateWithMailbox> localUpdates;
-
-	public MailboxPairedEvent(MailboxProperties properties,
-			Map<ContactId, MailboxUpdateWithMailbox> localUpdates) {
-		this.properties = properties;
-		this.localUpdates = localUpdates;
-	}
-
-	public MailboxProperties getProperties() {
-		return properties;
-	}
-
-	public Map<ContactId, MailboxUpdateWithMailbox> getLocalUpdates() {
-		return localUpdates;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/event/MailboxProblemEvent.java

@@ -1,19 +0,0 @@
-package org.briarproject.bramble.api.mailbox.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast by {@link MailboxSettingsManager} when
- * recording a connection failure for own Mailbox
- * that has persistent for long enough for the mailbox owner to become active
- * and fix the problem with the mailbox.
- */
-@Immutable
-@NotNullByDefault
-public class MailboxProblemEvent extends Event {
-
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/event/MailboxUnpairedEvent.java

@@ -1,28 +0,0 @@
-package org.briarproject.bramble.api.mailbox.event;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.Map;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when a mailbox is unpaired.
- */
-@Immutable
-@NotNullByDefault
-public class MailboxUnpairedEvent extends Event {
-
-	private final Map<ContactId, MailboxUpdate> localUpdates;
-
-	public MailboxUnpairedEvent(Map<ContactId, MailboxUpdate> localUpdates) {
-		this.localUpdates = localUpdates;
-	}
-
-	public Map<ContactId, MailboxUpdate> getLocalUpdates() {
-		return localUpdates;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/event/MailboxUpdateSentToNewContactEvent.java

@@ -1,40 +0,0 @@
-package org.briarproject.bramble.api.mailbox.event;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateManager;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when the first mailbox update is sent to a
- * newly added contact, which happens in the same transaction in which the
- * contact is added.
- * <p>
- * This event is not broadcast when the first mailbox update is sent to an
- * existing contact when setting up the
- * {@link MailboxUpdateManager mailbox update client}.
- */
-@Immutable
-@NotNullByDefault
-public class MailboxUpdateSentToNewContactEvent extends Event {
-
-	private final ContactId contactId;
-	private final MailboxUpdate mailboxUpdate;
-
-	public MailboxUpdateSentToNewContactEvent(ContactId contactId,
-			MailboxUpdate mailboxUpdate) {
-		this.contactId = contactId;
-		this.mailboxUpdate = mailboxUpdate;
-	}
-
-	public ContactId getContactId() {
-		return contactId;
-	}
-
-	public MailboxUpdate getMailboxUpdate() {
-		return mailboxUpdate;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/event/OwnMailboxConnectionStatusEvent.java

@@ -1,27 +0,0 @@
-package org.briarproject.bramble.api.mailbox.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.mailbox.MailboxSettingsManager;
-import org.briarproject.bramble.api.mailbox.MailboxStatus;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast by {@link MailboxSettingsManager} when
- * recording the connection status of own Mailbox.
- */
-@Immutable
-@NotNullByDefault
-public class OwnMailboxConnectionStatusEvent extends Event {
-
-	private final MailboxStatus status;
-
-	public OwnMailboxConnectionStatusEvent(MailboxStatus status) {
-		this.status = status;
-	}
-
-	public MailboxStatus getStatus() {
-		return status;
-	}
-}

bramble-api/src/main/java/org/briarproject/bramble/api/mailbox/event/RemoteMailboxUpdateEvent.java

@@ -1,34 +0,0 @@
-package org.briarproject.bramble.api.mailbox.event;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when {@link MailboxUpdate} are received
- * from a contact.
- */
-@Immutable
-@NotNullByDefault
-public class RemoteMailboxUpdateEvent extends Event {
-
-	private final ContactId contactId;
-	private final MailboxUpdate mailboxUpdate;
-
-	public RemoteMailboxUpdateEvent(ContactId contactId,
-			MailboxUpdate mailboxUpdate) {
-		this.contactId = contactId;
-		this.mailboxUpdate = mailboxUpdate;
-	}
-
-	public ContactId getContact() {
-		return contactId;
-	}
-
-	public MailboxUpdate getMailboxUpdate() {
-		return mailboxUpdate;
-	}
-}

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

@@ -1,7 +1,5 @@
 package org.briarproject.bramble.api.plugin;
 
-import static java.util.concurrent.TimeUnit.SECONDS;
-
 public interface TorConstants {
 
 	TransportId ID = new TransportId("org.briarproject.bramble.tor");
@@ -12,9 +10,8 @@ public interface TorConstants {
 	int DEFAULT_SOCKS_PORT = 59050;
 	int DEFAULT_CONTROL_PORT = 59051;
 
-	int CONNECT_TO_PROXY_TIMEOUT = (int) SECONDS.toMillis(5);
+	int CONNECT_TO_PROXY_TIMEOUT = 5000; // Milliseconds
-	int EXTRA_CONNECT_TIMEOUT = (int) SECONDS.toMillis(120);
+	int EXTRA_SOCKET_TIMEOUT = 30000; // Milliseconds
-	int EXTRA_SOCKET_TIMEOUT = (int) SECONDS.toMillis(30);
 
 	// Local settings (not shared with contacts)
 	String PREF_TOR_NETWORK = "network2";

bramble-api/src/main/java/org/briarproject/bramble/api/record/RecordWriter.java

@@ -12,6 +12,4 @@ public interface RecordWriter {
 	void flush() throws IOException;
 
 	void close() throws IOException;
-
-	long getBytesWritten();
 }

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

@@ -20,4 +20,9 @@ public class GroupId extends UniqueId {
 	public GroupId(byte[] id) {
 		super(id);
 	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof GroupId && super.equals(o);
+	}
 }

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

@@ -27,4 +27,9 @@ public class MessageId extends UniqueId {
 	public MessageId(byte[] id) {
 		super(id);
 	}
+
+	@Override
+	public boolean equals(Object o) {
+		return o instanceof MessageId && super.equals(o);
+	}
 }

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

@@ -1,37 +0,0 @@
-package org.briarproject.bramble.api.sync;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.Collection;
-import java.util.concurrent.CopyOnWriteArrayList;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-/**
- * A container for holding the IDs of messages sent and acked during an
- * outgoing {@link SyncSession}, so they can be recorded in the DB as sent
- * or acked at some later time.
- */
-@ThreadSafe
-@NotNullByDefault
-public class OutgoingSessionRecord {
-
-	private final Collection<MessageId> ackedIds = new CopyOnWriteArrayList<>();
-	private final Collection<MessageId> sentIds = new CopyOnWriteArrayList<>();
-
-	public void onAckSent(Collection<MessageId> acked) {
-		ackedIds.addAll(acked);
-	}
-
-	public void onMessageSent(MessageId sent) {
-		sentIds.add(sent);
-	}
-
-	public Collection<MessageId> getAckedIds() {
-		return ackedIds;
-	}
-
-	public Collection<MessageId> getSentIds() {
-		return sentIds;
-	}
-}

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

@@ -20,6 +20,4 @@ public interface SyncRecordWriter {
 	void writePriority(Priority p) throws IOException;
 
 	void flush() throws IOException;
-
-	long getBytesWritten();
 }

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

@@ -12,30 +12,12 @@ import javax.annotation.Nullable;
 @NotNullByDefault
 public interface SyncSessionFactory {
 
-	/**
-	 * Creates a session for receiving data from a contact.
-	 */
 	SyncSession createIncomingSession(ContactId c, InputStream in,
 			PriorityHandler handler);
 
-	/**
-	 * Creates a session for sending data to a contact over a simplex transport.
-	 *
-	 * @param eager True if messages should be sent eagerly, ie regardless of
-	 * whether they're due for retransmission.
-	 */
 	SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
 			long maxLatency, boolean eager, StreamWriter streamWriter);
 
-	/**
-	 * Creates a session for sending data to a contact via a mailbox. The IDs
-	 * of any messages sent or acked will be added to the given
-	 * {@link OutgoingSessionRecord}.
-	 */
-	SyncSession createSimplexOutgoingSession(ContactId c, TransportId t,
-			long maxLatency, StreamWriter streamWriter,
-			OutgoingSessionRecord sessionRecord);
-
 	SyncSession createDuplexOutgoingSession(ContactId c, TransportId t,
 			long maxLatency, int maxIdleTime, StreamWriter streamWriter,
 			@Nullable Priority priority);

bramble-api/src/main/java/org/briarproject/bramble/api/sync/event/GroupVisibilityUpdatedEvent.java

@@ -3,7 +3,6 @@ package org.briarproject.bramble.api.sync.event;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.Group.Visibility;
 
 import java.util.Collection;
 
@@ -16,19 +15,12 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class GroupVisibilityUpdatedEvent extends Event {
 
-	private final Visibility visibility;
 	private final Collection<ContactId> affected;
 
-	public GroupVisibilityUpdatedEvent(Visibility visibility,
+	public GroupVisibilityUpdatedEvent(Collection<ContactId> affected) {
-			Collection<ContactId> affected) {
-		this.visibility = visibility;
 		this.affected = affected;
 	}
 
-	public Visibility getVisibility() {
-		return visibility;
-	}
-
 	/**
 	 * Returns the contacts affected by the update.
 	 */

bramble-api/src/main/java/org/briarproject/bramble/api/sync/event/MessageSharedEvent.java

@@ -1,14 +1,9 @@
 package org.briarproject.bramble.api.sync.event;
 
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.Group.Visibility;
-import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 
-import java.util.Map;
-
 import javax.annotation.concurrent.Immutable;
 
 /**
@@ -19,32 +14,12 @@ import javax.annotation.concurrent.Immutable;
 public class MessageSharedEvent extends Event {
 
 	private final MessageId messageId;
-	private final GroupId groupId;
-	private final Map<ContactId, Boolean> groupVisibility;
 
-	public MessageSharedEvent(MessageId message, GroupId groupId,
+	public MessageSharedEvent(MessageId message) {
-			Map<ContactId, Boolean> groupVisibility) {
 		this.messageId = message;
-		this.groupId = groupId;
-		this.groupVisibility = groupVisibility;
 	}
 
 	public MessageId getMessageId() {
 		return messageId;
 	}
-
-	public GroupId getGroupId() {
-		return groupId;
-	}
-
-	/**
-	 * Returns the IDs of all contacts for which the visibility of the
-	 * message's group is either {@link Visibility#SHARED shared} or
-	 * {@link Visibility#VISIBLE visible}. The value in the map is true if the
-	 * group is {@link Visibility#SHARED shared} or false if the group is
-	 * {@link Visibility#VISIBLE visible}.
-	 */
-	public Map<ContactId, Boolean> getGroupVisibility() {
-		return groupVisibility;
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/system/TaskScheduler.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.api.system;
 
-import org.briarproject.bramble.api.Cancellable;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.util.concurrent.Executor;
@@ -17,8 +16,6 @@ public interface TaskScheduler {
 	 * <p>
 	 * If the platform supports wake locks, a wake lock will be held while
 	 * submitting and running the task.
-	 *
-	 * @return A {@link Cancellable} for cancelling the task.
 	 */
 	Cancellable schedule(Runnable task, Executor executor, long delay,
 			TimeUnit unit);
@@ -30,11 +27,17 @@ public interface TaskScheduler {
 	 * <p>
 	 * If the platform supports wake locks, a wake lock will be held while
 	 * submitting and running the task.
-	 *
-	 * @return A {@link Cancellable} for cancelling all future executions of
-	 * the task.
 	 */
 	Cancellable scheduleWithFixedDelay(Runnable task, Executor executor,
 			long delay, long interval, TimeUnit unit);
 
+	interface Cancellable {
+
+		/**
+		 * Cancels the task if it has not already started running. If the task
+		 * is {@link #scheduleWithFixedDelay(Runnable, Executor, long, long, TimeUnit) periodic},
+		 * all future executions of the task are cancelled.
+		 */
+		void cancel();
+	}
 }

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

@@ -40,7 +40,7 @@ public class IoUtils {
 		}
 	}
 
-	public static void delete(File f) {
+	private static void delete(File f) {
 		if (!f.delete() && LOG.isLoggable(WARNING))
 			LOG.warning("Could not delete " + f.getAbsolutePath());
 	}

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

@@ -26,7 +26,7 @@ public class NetworkUtils {
 			// Despite what the docs say, the return value can be null
 			//noinspection ConstantConditions
 			return ifaces == null ? emptyList() : list(ifaces);
-		} catch (SocketException | NullPointerException e) {
+		} catch (SocketException e) {
 			logException(LOG, WARNING, e);
 			return emptyList();
 		}

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.util;
 
-import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.UnsupportedEncodingException;
@@ -96,10 +95,10 @@ public class StringUtils {
 	/**
 	 * Converts the given hex string to a byte array.
 	 */
-	public static byte[] fromHexString(String hex) throws FormatException {
+	public static byte[] fromHexString(String hex) {
 		int len = hex.length();
 		if (len % 2 != 0)
-			throw new FormatException();
+			throw new IllegalArgumentException("Not a hex string");
 		byte[] bytes = new byte[len / 2];
 		for (int i = 0, j = 0; i < len; i += 2, j++) {
 			int high = hexDigitToInt(hex.charAt(i));
@@ -109,11 +108,11 @@ public class StringUtils {
 		return bytes;
 	}
 
-	private static int hexDigitToInt(char c) throws FormatException {
+	private static int hexDigitToInt(char c) {
 		if (c >= '0' && c <= '9') return c - '0';
 		if (c >= 'A' && c <= 'F') return c - 'A' + 10;
 		if (c >= 'a' && c <= 'f') return c - 'a' + 10;
-		throw new FormatException();
+		throw new IllegalArgumentException("Not a hex digit: " + c);
 	}
 
 	public static String trim(String s) {
@@ -131,13 +130,13 @@ public class StringUtils {
 		return MAC.matcher(mac).matches();
 	}
 
-	public static byte[] macToBytes(String mac) throws FormatException {
+	public static byte[] macToBytes(String mac) {
-		if (!MAC.matcher(mac).matches()) throw new FormatException();
+		if (!MAC.matcher(mac).matches()) throw new IllegalArgumentException();
 		return fromHexString(mac.replaceAll(":", ""));
 	}
 
-	public static String macToString(byte[] mac) throws FormatException {
+	public static String macToString(byte[] mac) {
-		if (mac.length != 6) throw new FormatException();
+		if (mac.length != 6) throw new IllegalArgumentException();
 		StringBuilder s = new StringBuilder();
 		for (byte b : mac) {
 			if (s.length() > 0) s.append(':');

bramble-api/src/test/java/org/briarproject/bramble/api/mailbox/MailboxHelperTest.java

@@ -1,44 +0,0 @@
-package org.briarproject.bramble.api.mailbox;
-
-import org.junit.Test;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Random;
-
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.API_CLIENT_TOO_OLD;
-import static org.briarproject.bramble.api.mailbox.MailboxConstants.API_SERVER_TOO_OLD;
-import static org.briarproject.bramble.api.mailbox.MailboxHelper.getHighestCommonMajorVersion;
-import static org.junit.Assert.assertEquals;
-
-public class MailboxHelperTest {
-
-	private final Random random = new Random();
-
-	@Test
-	public void testGetHighestCommonMajorVersion() {
-		assertEquals(2, getHighestCommonMajorVersion(v(2), v(2)));
-		assertEquals(2, getHighestCommonMajorVersion(v(1, 2), v(2, 3, 4)));
-		assertEquals(2, getHighestCommonMajorVersion(v(2, 3, 4), v(2)));
-		assertEquals(2, getHighestCommonMajorVersion(v(2), v(2, 3, 4)));
-
-		assertEquals(API_CLIENT_TOO_OLD,
-				getHighestCommonMajorVersion(v(2), v(3, 4)));
-		assertEquals(API_CLIENT_TOO_OLD,
-				getHighestCommonMajorVersion(v(2), v(1, 3)));
-		assertEquals(API_SERVER_TOO_OLD,
-				getHighestCommonMajorVersion(v(3, 4, 5), v(2)));
-		assertEquals(API_SERVER_TOO_OLD,
-				getHighestCommonMajorVersion(v(1, 3), v(2)));
-	}
-
-	private List<MailboxVersion> v(int... ints) {
-		List<MailboxVersion> versions = new ArrayList<>(ints.length);
-		for (int v : ints) {
-			// minor versions should not matter
-			versions.add(new MailboxVersion(v, random.nextInt(42)));
-		}
-		return versions;
-	}
-
-}

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

@@ -1,46 +1,17 @@
 package org.briarproject.bramble.test;
 
-import org.junit.After;
-import org.junit.Before;
-
 import java.lang.Thread.UncaughtExceptionHandler;
-import java.util.logging.Logger;
 
-import javax.annotation.Nullable;
+import static org.junit.Assert.fail;
-
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
 
 public abstract class BrambleTestCase {
 
-	private static final Logger LOG =
-			getLogger(BrambleTestCase.class.getName());
-
-	@Nullable
-	protected volatile Throwable exceptionInBackgroundThread = null;
-
 	public BrambleTestCase() {
 		// Ensure exceptions thrown on worker threads cause tests to fail
 		UncaughtExceptionHandler fail = (thread, throwable) -> {
-			LOG.log(WARNING, "Caught unhandled exception", throwable);
+			throwable.printStackTrace();
-			exceptionInBackgroundThread = throwable;
+			fail();
 		};
 		Thread.setDefaultUncaughtExceptionHandler(fail);
 	}
-
-	@Before
-	public void beforeBrambleTestCase() {
-		exceptionInBackgroundThread = null;
-	}
-
-	@After
-	public void afterBrambleTestCase() {
-		Throwable thrown = exceptionInBackgroundThread;
-		if (thrown != null) {
-			LOG.log(WARNING,
-					"Background thread has thrown an exception unexpectedly",
-					thrown);
-			throw new AssertionError(thrown);
-		}
-	}
 }

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

@@ -12,20 +12,10 @@ import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.SignaturePrivateKey;
 import org.briarproject.bramble.api.crypto.SignaturePublicKey;
-import org.briarproject.bramble.api.db.CommitAction;
-import org.briarproject.bramble.api.db.EventAction;
-import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
 import org.briarproject.bramble.api.identity.Identity;
 import org.briarproject.bramble.api.identity.LocalAuthor;
-import org.briarproject.bramble.api.mailbox.MailboxAuthToken;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateWithMailbox;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.sync.ClientId;
@@ -35,24 +25,17 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.util.IoUtils;
 
-import java.io.ByteArrayOutputStream;
 import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Random;
 import java.util.concurrent.atomic.AtomicInteger;
 
-import javax.annotation.Nullable;
-import javax.crypto.Cipher;
-
 import static java.util.Arrays.asList;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.MAX_AGREEMENT_PUBLIC_KEY_BYTES;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.MAX_SIGNATURE_PUBLIC_KEY_BYTES;
@@ -63,8 +46,8 @@ import static org.briarproject.bramble.api.properties.TransportPropertyConstants
 import static org.briarproject.bramble.api.sync.ClientId.MAX_CLIENT_ID_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_GROUP_DESCRIPTOR_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
-import static org.briarproject.bramble.util.IoUtils.copyAndClose;
 import static org.briarproject.bramble.util.StringUtils.getRandomString;
+import static org.briarproject.bramble.util.StringUtils.toHexString;
 
 public class TestUtils {
 
@@ -228,35 +211,8 @@ public class TestUtils {
 				getAgreementPublicKey(), verified);
 	}
 
-	public static MailboxProperties getMailboxProperties(boolean owner,
+	public static String getMailboxSecret() {
-			List<MailboxVersion> serverSupports) {
+		return toHexString(getRandomBytes(32)).toLowerCase(Locale.US);
-		String onion = getRandomString(56);
-		MailboxAuthToken authToken = new MailboxAuthToken(getRandomId());
-		if (owner) {
-			return new MailboxProperties(onion, authToken, serverSupports);
-		}
-		MailboxFolderId inboxId = new MailboxFolderId(getRandomId());
-		MailboxFolderId outboxId = new MailboxFolderId(getRandomId());
-		return new MailboxProperties(onion, authToken, serverSupports,
-				inboxId, outboxId);
-	}
-
-	public static void writeBytes(File file, byte[] bytes)
-			throws IOException {
-		FileOutputStream outputStream = new FileOutputStream(file);
-		//noinspection TryFinallyCanBeTryWithResources
-		try {
-			outputStream.write(bytes);
-		} finally {
-			outputStream.close();
-		}
-	}
-
-	public static byte[] readBytes(File file) throws IOException {
-		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
-		FileInputStream inputStream = new FileInputStream(file);
-		copyAndClose(inputStream, outputStream);
-		return outputStream.toByteArray();
 	}
 
 	public static double getMedian(Collection<? extends Number> samples) {
@@ -293,68 +249,9 @@ public class TestUtils {
 		return Math.sqrt(getVariance(samples));
 	}
 
-	public static boolean isOptionalTestEnabled(Class<?> testClass) {
+	public static boolean isOptionalTestEnabled(Class testClass) {
 		String optionalTests = System.getenv("OPTIONAL_TESTS");
 		return optionalTests != null &&
 				asList(optionalTests.split(",")).contains(testClass.getName());
 	}
-
-	public static boolean mailboxUpdateEqual(@Nullable MailboxUpdate a,
-			@Nullable MailboxUpdate b) {
-		if (a == null || b == null) {
-			return a == b;
-		}
-		if (!a.hasMailbox() && !b.hasMailbox()) {
-			return a.getClientSupports().equals(b.getClientSupports());
-		} else if (a.hasMailbox() && b.hasMailbox()) {
-			MailboxUpdateWithMailbox am = (MailboxUpdateWithMailbox) a;
-			MailboxUpdateWithMailbox bm = (MailboxUpdateWithMailbox) b;
-			return am.getClientSupports().equals(bm.getClientSupports()) &&
-					mailboxPropertiesEqual(am.getMailboxProperties(),
-							bm.getMailboxProperties());
-		}
-		return false;
-	}
-
-	public static boolean mailboxPropertiesEqual(@Nullable MailboxProperties a,
-			@Nullable MailboxProperties b) {
-		if (a == null || b == null) {
-			return a == b;
-		}
-		return a.getOnion().equals(b.getOnion()) &&
-				a.getAuthToken().equals(b.getAuthToken()) &&
-				a.isOwner() == b.isOwner() &&
-				a.getServerSupports().equals(b.getServerSupports());
-	}
-
-	public static boolean hasEvent(Transaction txn,
-			Class<? extends Event> eventClass) {
-		for (CommitAction action : txn.getActions()) {
-			if (action instanceof EventAction) {
-				Event event = ((EventAction) action).getEvent();
-				if (eventClass.isInstance(event)) return true;
-			}
-		}
-		return false;
-	}
-
-	public static <E extends Event> E getEvent(Transaction txn,
-			Class<E> eventClass) {
-		for (CommitAction action : txn.getActions()) {
-			if (action instanceof EventAction) {
-				Event event = ((EventAction) action).getEvent();
-				if (eventClass.isInstance(event)) return eventClass.cast(event);
-			}
-		}
-		throw new AssertionError();
-	}
-
-	public static boolean isCryptoStrengthUnlimited() {
-		try {
-			return Cipher.getMaxAllowedKeyLength("AES/CBC/PKCS5Padding")
-					== Integer.MAX_VALUE;
-		} catch (NoSuchAlgorithmException e) {
-			throw new AssertionError();
-		}
-	}
 }

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

@@ -1,36 +0,0 @@
-package org.briarproject.bramble.test;
-
-import org.junit.Test;
-
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.fail;
-
-public class ThreadExceptionTest extends BrambleTestCase {
-
-	@Test(expected = AssertionError.class)
-	public void testAssertionErrorMakesTestCaseFail() {
-		// This is what BrambleTestCase does, too:
-		fail();
-	}
-
-	@Test
-	public void testExceptionInThreadMakesTestCaseFail() {
-		Thread t = new Thread(() -> {
-			System.out.println("thread before exception");
-			throw new RuntimeException("boom");
-		});
-
-		t.start();
-		try {
-			t.join();
-			System.out.println("joined thread");
-		} catch (InterruptedException e) {
-			System.out.println("interrupted while joining thread");
-			fail();
-		}
-
-		assertNotNull(exceptionInBackgroundThread);
-		exceptionInBackgroundThread = null;
-	}
-
-}

bramble-api/witness.gradle

@@ -1,7 +1,6 @@
 dependencyVerification {
     verify = [
         'cglib:cglib:3.2.8:cglib-3.2.8.jar:3f64de999ecc5595dc84ca8ff0879d8a34c8623f9ef3c517a53ed59023fcb9db',
-        'com.fasterxml.jackson.core:jackson-annotations:2.13.0:jackson-annotations-2.13.0.jar:81f9724d8843e8b08f8f6c0609e7a2b030d00c34861c4ac7e2099a7235047d6f',
         'com.google.code.findbugs:annotations:3.0.1:annotations-3.0.1.jar:6b47ff0a6de0ce17cbedc3abb0828ca5bce3009d53ea47b3723ff023c4742f79',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
         'com.google.dagger:dagger:2.33:dagger-2.33.jar:d8798c5b8cf6b125234e33af5c6293bb9f2208ce29b57924c35b8c0be7b6bdcb',

bramble-core/build.gradle

@@ -7,7 +7,6 @@ apply plugin: 'idea'
 apply plugin: 'witness'
 apply from: 'witness.gradle'
 apply from: '../dagger.gradle'
-apply plugin: 'checkstyle'
 
 dependencies {
 	implementation project(path: ':bramble-api', configuration: 'default')
@@ -17,7 +16,7 @@ dependencies {
 	implementation 'org.bitlet:weupnp:0.1.4'
 	implementation 'net.i2p.crypto:eddsa:0.2.0'
 	implementation 'org.whispersystems:curve25519-java:0.5.0'
-	implementation 'org.briarproject:jtorctl:0.5'
+	implementation 'org.briarproject:jtorctl:0.3'
 
 	//noinspection GradleDependency
 	implementation "com.squareup.okhttp3:okhttp:$okhttp_version"

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

@@ -6,7 +6,6 @@ import org.briarproject.bramble.crypto.CryptoExecutorModule;
 import org.briarproject.bramble.db.DatabaseExecutorModule;
 import org.briarproject.bramble.identity.IdentityModule;
 import org.briarproject.bramble.lifecycle.LifecycleModule;
-import org.briarproject.bramble.mailbox.MailboxModule;
 import org.briarproject.bramble.plugin.PluginModule;
 import org.briarproject.bramble.properties.PropertiesModule;
 import org.briarproject.bramble.rendezvous.RendezvousModule;
@@ -29,8 +28,6 @@ public interface BrambleCoreEagerSingletons {
 
 	void inject(LifecycleModule.EagerSingletons init);
 
-	void inject(MailboxModule.EagerSingletons init);
-
 	void inject(PluginModule.EagerSingletons init);
 
 	void inject(PropertiesModule.EagerSingletons init);
@@ -54,7 +51,6 @@ public interface BrambleCoreEagerSingletons {
 			c.inject(new DatabaseExecutorModule.EagerSingletons());
 			c.inject(new IdentityModule.EagerSingletons());
 			c.inject(new LifecycleModule.EagerSingletons());
-			c.inject(new MailboxModule.EagerSingletons());
 			c.inject(new RendezvousModule.EagerSingletons());
 			c.inject(new PluginModule.EagerSingletons());
 			c.inject(new PropertiesModule.EagerSingletons());

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.account;
 
-import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.DecryptionException;
@@ -210,13 +209,7 @@ class AccountManagerImpl implements AccountManager {
 			LOG.warning("Failed to load encrypted database key");
 			throw new DecryptionException(INVALID_CIPHERTEXT);
 		}
-		byte[] ciphertext;
+		byte[] ciphertext = fromHexString(hex);
-		try {
-			ciphertext = fromHexString(hex);
-		} catch (FormatException e) {
-			LOG.warning("Encrypted database key has invalid format");
-			throw new DecryptionException(INVALID_CIPHERTEXT);
-		}
 		KeyStrengthener keyStrengthener = databaseConfig.getKeyStrengthener();
 		byte[] plaintext = crypto.decryptWithPassword(ciphertext, password,
 				keyStrengthener);

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

@@ -1,7 +1,6 @@
 package org.briarproject.bramble.client;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
@@ -23,12 +22,6 @@ import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorFactory;
-import org.briarproject.bramble.api.mailbox.MailboxAuthToken;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxUpdate;
-import org.briarproject.bramble.api.mailbox.MailboxUpdateWithMailbox;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportProperties;
@@ -36,33 +29,23 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.util.Base32;
 
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.security.GeneralSecurityException;
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.HashMap;
-import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
 
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
-import static java.util.Collections.sort;
 import static org.briarproject.bramble.api.client.ContactGroupConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.api.identity.Author.FORMAT_VERSION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_COUNT;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_KEY_AUTHTOKEN;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_KEY_INBOXID;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_KEY_ONION;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_KEY_OUTBOXID;
-import static org.briarproject.bramble.api.mailbox.MailboxUpdateManager.PROP_ONION_LENGTH;
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MAX_PROPERTIES_PER_TRANSPORT;
 import static org.briarproject.bramble.api.properties.TransportPropertyConstants.MAX_PROPERTY_LENGTH;
 import static org.briarproject.bramble.util.ValidationUtils.checkLength;
@@ -416,70 +399,6 @@ class ClientHelperImpl implements ClientHelper {
 		return tpMap;
 	}
 
-	@Override
-	public MailboxUpdate parseAndValidateMailboxUpdate(BdfList clientSupports,
-			BdfList serverSupports, BdfDictionary properties)
-			throws FormatException {
-		List<MailboxVersion> clientSupportsList =
-				parseMailboxVersionList(clientSupports);
-		List<MailboxVersion> serverSupportsList =
-				parseMailboxVersionList(serverSupports);
-
-		// We must always learn what Mailbox API version(s) the client supports
-		if (clientSupports.isEmpty()) {
-			throw new FormatException();
-		}
-		if (properties.isEmpty()) {
-			// No mailbox -- cannot claim to support any API versions!
-			if (!serverSupports.isEmpty()) {
-				throw new FormatException();
-			}
-			return new MailboxUpdate(clientSupportsList);
-		}
-		// Mailbox must be accompanied by the Mailbox API version(s) it supports
-		if (serverSupports.isEmpty()) {
-			throw new FormatException();
-		}
-		// Accepting more props than we need, for forward compatibility
-		if (properties.size() < PROP_COUNT) {
-			throw new FormatException();
-		}
-		String onion = properties.getString(PROP_KEY_ONION);
-		checkLength(onion, PROP_ONION_LENGTH);
-		try {
-			Base32.decode(onion, true);
-		} catch (IllegalArgumentException e) {
-			throw new FormatException();
-		}
-		byte[] authToken = properties.getRaw(PROP_KEY_AUTHTOKEN);
-		checkLength(authToken, UniqueId.LENGTH);
-		byte[] inboxId = properties.getRaw(PROP_KEY_INBOXID);
-		checkLength(inboxId, UniqueId.LENGTH);
-		byte[] outboxId = properties.getRaw(PROP_KEY_OUTBOXID);
-		checkLength(outboxId, UniqueId.LENGTH);
-		MailboxProperties props = new MailboxProperties(onion,
-				new MailboxAuthToken(authToken), serverSupportsList,
-				new MailboxFolderId(inboxId), new MailboxFolderId(outboxId));
-		return new MailboxUpdateWithMailbox(clientSupportsList, props);
-	}
-
-	@Override
-	public List<MailboxVersion> parseMailboxVersionList(BdfList bdfList)
-			throws FormatException {
-		List<MailboxVersion> list = new ArrayList<>();
-		for (int i = 0; i < bdfList.size(); i++) {
-			BdfList element = bdfList.getList(i);
-			if (element.size() != 2) {
-				throw new FormatException();
-			}
-			list.add(new MailboxVersion(element.getLong(0).intValue(),
-					element.getLong(1).intValue()));
-		}
-		// Sort the list of versions for easier comparison
-		sort(list);
-		return list;
-	}
-
 	@Override
 	public ContactId getContactId(Transaction txn, GroupId contactGroupId)
 			throws DbException {

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

@@ -54,7 +54,7 @@ abstract class Connection {
 		}
 	}
 
-	byte[] readTag(InputStream in) throws IOException {
+	private byte[] readTag(InputStream in) throws IOException {
 		byte[] tag = new byte[TAG_LENGTH];
 		read(in, tag);
 		return tag;

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

@@ -13,7 +13,6 @@ import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
 import org.briarproject.bramble.api.transport.StreamReaderFactory;
@@ -68,15 +67,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 			TransportConnectionReader r) {
 		ioExecutor.execute(new IncomingSimplexSyncConnection(keyManager,
 				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, t, r, null));
+				syncSessionFactory, transportPropertyManager, t, r));
-	}
-
-	@Override
-	public void manageIncomingConnection(TransportId t,
-			TransportConnectionReader r, TagController c) {
-		ioExecutor.execute(new IncomingSimplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, t, r, c));
 	}
 
 	@Override
@@ -101,16 +92,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 			TransportConnectionWriter w) {
 		ioExecutor.execute(new OutgoingSimplexSyncConnection(keyManager,
 				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, c, t, w, null));
+				syncSessionFactory, transportPropertyManager, c, t, w));
-	}
-
-	@Override
-	public void manageOutgoingConnection(ContactId c, TransportId t,
-			TransportConnectionWriter w, OutgoingSessionRecord sessionRecord) {
-		ioExecutor.execute(new OutgoingSimplexSyncConnection(keyManager,
-				connectionRegistry, streamReaderFactory, streamWriterFactory,
-				syncSessionFactory, transportPropertyManager, c, t, w,
-				sessionRecord));
 	}
 
 	@Override

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

@@ -1,9 +1,7 @@
 package org.briarproject.bramble.connection;
 
-import org.briarproject.bramble.api.connection.ConnectionManager.TagController;
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportId;
@@ -17,8 +15,6 @@ import org.briarproject.bramble.api.transport.StreamWriterFactory;
 
 import java.io.IOException;
 
-import javax.annotation.Nullable;
-
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
@@ -27,8 +23,6 @@ class IncomingSimplexSyncConnection extends SyncConnection implements Runnable {
 
 	private final TransportId transportId;
 	private final TransportConnectionReader reader;
-	@Nullable
-	private final TagController tagController;
 
 	IncomingSimplexSyncConnection(KeyManager keyManager,
 			ConnectionRegistry connectionRegistry,
@@ -36,50 +30,33 @@ class IncomingSimplexSyncConnection extends SyncConnection implements Runnable {
 			StreamWriterFactory streamWriterFactory,
 			SyncSessionFactory syncSessionFactory,
 			TransportPropertyManager transportPropertyManager,
-			TransportId transportId,
+			TransportId transportId, TransportConnectionReader reader) {
-			TransportConnectionReader reader,
-			@Nullable TagController tagController) {
 		super(keyManager, connectionRegistry, streamReaderFactory,
 				streamWriterFactory, syncSessionFactory,
 				transportPropertyManager);
 		this.transportId = transportId;
 		this.reader = reader;
-		this.tagController = tagController;
 	}
 
 	@Override
 	public void run() {
 		// Read and recognise the tag
-		byte[] tag;
+		StreamContext ctx = recogniseTag(reader, transportId);
-		StreamContext ctx;
-		try {
-			tag = readTag(reader.getInputStream());
-			// If we have a tag controller, defer marking the tag as recognised
-			if (tagController == null) {
-				ctx = keyManager.getStreamContext(transportId, tag);
-			} else {
-				ctx = keyManager.getStreamContextOnly(transportId, tag);
-			}
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			onError();
-			return;
-		}
 		if (ctx == null) {
 			LOG.info("Unrecognised tag");
-			onError();
+			onError(false);
 			return;
 		}
 		ContactId contactId = ctx.getContactId();
 		if (contactId == null) {
 			LOG.warning("Received rendezvous stream, expected contact");
-			onError(tag);
+			onError(true);
 			return;
 		}
 		if (ctx.isHandshakeMode()) {
 			// TODO: Support handshake mode for contacts
 			LOG.warning("Received handshake tag, expected rotation mode");
-			onError(tag);
+			onError(true);
 			return;
 		}
 		try {
@@ -88,33 +65,15 @@ class IncomingSimplexSyncConnection extends SyncConnection implements Runnable {
 					LOG.info("Ignoring priority for simplex connection");
 			// Create and run the incoming session
 			createIncomingSession(ctx, reader, handler).run();
-			// Success
-			markTagAsRecognisedIfRequired(false, tag);
 			reader.dispose(false, true);
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
-			onError(tag);
+			onError(true);
 		}
 	}
 
-	private void onError() {
+	private void onError(boolean recognised) {
-		disposeOnError(reader, false);
+		disposeOnError(reader, recognised);
-	}
-
-	private void onError(byte[] tag) {
-		markTagAsRecognisedIfRequired(true, tag);
-		disposeOnError(reader, true);
-	}
-
-	private void markTagAsRecognisedIfRequired(boolean exception, byte[] tag) {
-		if (tagController != null &&
-				tagController.shouldMarkTagAsRecognised(exception)) {
-			try {
-				keyManager.markTagAsRecognised(transportId, tag);
-			} catch (DbException e) {
-				logException(LOG, WARNING, e);
-			}
-		}
 	}
 }
 

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

@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
-import org.briarproject.bramble.api.sync.OutgoingSessionRecord;
 import org.briarproject.bramble.api.sync.SyncSession;
 import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
@@ -17,8 +16,6 @@ import org.briarproject.bramble.api.transport.StreamWriterFactory;
 
 import java.io.IOException;
 
-import javax.annotation.Nullable;
-
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 import static org.briarproject.bramble.util.LogUtils.logException;
@@ -29,8 +26,6 @@ class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
 	private final ContactId contactId;
 	private final TransportId transportId;
 	private final TransportConnectionWriter writer;
-	@Nullable
-	private final OutgoingSessionRecord sessionRecord;
 
 	OutgoingSimplexSyncConnection(KeyManager keyManager,
 			ConnectionRegistry connectionRegistry,
@@ -39,15 +34,13 @@ class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
 			SyncSessionFactory syncSessionFactory,
 			TransportPropertyManager transportPropertyManager,
 			ContactId contactId, TransportId transportId,
-			TransportConnectionWriter writer,
+			TransportConnectionWriter writer) {
-			@Nullable OutgoingSessionRecord sessionRecord) {
 		super(keyManager, connectionRegistry, streamReaderFactory,
 				streamWriterFactory, syncSessionFactory,
 				transportPropertyManager);
 		this.contactId = contactId;
 		this.transportId = transportId;
 		this.writer = writer;
-		this.sessionRecord = sessionRecord;
 	}
 
 	@Override
@@ -78,16 +71,10 @@ class OutgoingSimplexSyncConnection extends SyncConnection implements Runnable {
 		StreamWriter streamWriter = streamWriterFactory.createStreamWriter(
 				w.getOutputStream(), ctx);
 		ContactId c = requireNonNull(ctx.getContactId());
-		if (sessionRecord == null) {
+		// Use eager retransmission if the transport is lossy and cheap
-			// Use eager retransmission if the transport is lossy and cheap
+		return syncSessionFactory.createSimplexOutgoingSession(c,
-			return syncSessionFactory.createSimplexOutgoingSession(c,
+				ctx.getTransportId(), w.getMaxLatency(), w.isLossyAndCheap(),
-					ctx.getTransportId(), w.getMaxLatency(),
+				streamWriter);
-					w.isLossyAndCheap(), streamWriter);
-		} else {
-			return syncSessionFactory.createSimplexOutgoingSession(c,
-					ctx.getTransportId(), w.getMaxLatency(), streamWriter,
-					sessionRecord);
-		}
 	}
 }
 

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

@@ -131,8 +131,7 @@ class ContactManagerImpl implements ContactManager, EventListener {
 	}
 
 	@Override
-	public PendingContact addPendingContact(Transaction txn, String link,
+	public PendingContact addPendingContact(Transaction txn, String link, String alias)
-			String alias)
 			throws DbException, FormatException, GeneralSecurityException {
 		PendingContact p =
 				pendingContactFactory.createPendingContact(link, alias);
@@ -170,8 +169,7 @@ class ContactManagerImpl implements ContactManager, EventListener {
 	}
 
 	@Override
-	public Collection<Pair<PendingContact, PendingContactState>> getPendingContacts(
+	public Collection<Pair<PendingContact, PendingContactState>> getPendingContacts(Transaction txn)
-			Transaction txn)
 			throws DbException {
 		Collection<PendingContact> pendingContacts = db.getPendingContacts(txn);
 		List<Pair<PendingContact, PendingContactState>> pairs =
@@ -186,13 +184,7 @@ class ContactManagerImpl implements ContactManager, EventListener {
 
 	@Override
 	public void removePendingContact(PendingContactId p) throws DbException {
-		db.transaction(false, txn -> removePendingContact(txn, p));
+		db.transaction(false, txn -> db.removePendingContact(txn, p));
-	}
-
-	@Override
-	public void removePendingContact(Transaction txn, PendingContactId p)
-			throws DbException {
-		db.removePendingContact(txn, p);
 		states.remove(p);
 	}
 

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

@@ -8,7 +8,6 @@ import org.bouncycastle.crypto.CryptoException;
 import org.bouncycastle.crypto.Digest;
 import org.bouncycastle.crypto.digests.Blake2bDigest;
 import org.bouncycastle.crypto.digests.SHA3Digest;
-import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.crypto.AgreementPrivateKey;
 import org.briarproject.bramble.api.crypto.AgreementPublicKey;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
@@ -42,7 +41,6 @@ import javax.inject.Inject;
 
 import static java.lang.System.arraycopy;
 import static java.util.logging.Level.INFO;
-import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_AGREEMENT;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.KEY_TYPE_SIGNATURE;
 import static org.briarproject.bramble.api.crypto.DecryptionResult.INVALID_CIPHERTEXT;
@@ -56,7 +54,7 @@ import static org.briarproject.bramble.util.LogUtils.now;
 class CryptoComponentImpl implements CryptoComponent {
 
 	private static final Logger LOG =
-			getLogger(CryptoComponentImpl.class.getName());
+			Logger.getLogger(CryptoComponentImpl.class.getName());
 
 	private static final int SIGNATURE_KEY_PAIR_BITS = 256;
 	private static final int STORAGE_IV_BYTES = 24; // 196 bits
@@ -130,13 +128,6 @@ class CryptoComponentImpl implements CryptoComponent {
 		}
 	}
 
-	@Override
-	public UniqueId generateUniqueId() {
-		byte[] b = new byte[UniqueId.LENGTH];
-		secureRandom.nextBytes(b);
-		return new UniqueId(b);
-	}
-
 	@Override
 	public SecretKey generateSecretKey() {
 		byte[] b = new byte[SecretKey.LENGTH];
@@ -458,7 +449,7 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public String encodeOnion(byte[] publicKey) {
+	public String encodeOnionAddress(byte[] publicKey) {
 		Digest digest = new SHA3Digest(256);
 		byte[] label = ".onion checksum".getBytes(Charset.forName("US-ASCII"));
 		digest.update(label, 0, label.length);

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

@@ -163,11 +163,16 @@ interface Database<T> {
 			throws DbException;
 
 	/**
-	 * Returns true if there are any acks to send to the given contact.
+	 * Returns true if there are any acks or messages to send to the given
+	 * contact over a transport with the given maximum latency.
 	 * <p/>
 	 * Read-only.
+	 *
+	 * @param eager True if messages that are not yet due for retransmission
+	 * should be included
 	 */
-	boolean containsAcksToSend(T txn, ContactId c) throws DbException;
+	boolean containsAnythingToSend(T txn, ContactId c, long maxLatency,
+			boolean eager) throws DbException;
 
 	/**
 	 * Returns true if the database contains the given contact for the given
@@ -207,18 +212,6 @@ interface Database<T> {
 	 */
 	boolean containsMessage(T txn, MessageId m) throws DbException;
 
-	/**
-	 * Returns true if there are any messages to send to the given
-	 * contact over a transport with the given maximum latency.
-	 * <p/>
-	 * Read-only.
-	 *
-	 * @param eager True if messages that are not yet due for retransmission
-	 * should be included
-	 */
-	boolean containsMessagesToSend(T txn, ContactId c, long maxLatency,
-			boolean eager) throws DbException;
-
 	/**
 	 * Returns true if the database contains the given pending contact.
 	 * <p/>
@@ -320,13 +313,6 @@ interface Database<T> {
 	 */
 	Group getGroup(T txn, GroupId g) throws DbException;
 
-	/**
-	 * Returns the ID of the group containing the given message.
-	 * <p/>
-	 * Read-only.
-	 */
-	GroupId getGroupId(T txn, MessageId m) throws DbException;
-
 	/**
 	 * Returns the metadata for the given group.
 	 * <p/>
@@ -352,11 +338,8 @@ interface Database<T> {
 			throws DbException;
 
 	/**
-	 * Returns the IDs of all contacts for which the given group's visibility
+	 * Returns the IDs of all contacts to which the given group's visibility is
-	 * is either {@link Visibility#SHARED shared} or
+	 * either {@link Visibility VISIBLE} or {@link Visibility SHARED}.
-	 * {@link Visibility#VISIBLE visible}. The value in the map is true if the
-	 * group is {@link Visibility#SHARED shared} or false if the group is
-	 * {@link Visibility#VISIBLE visible}.
 	 * <p/>
 	 * Read-only.
 	 */
@@ -423,12 +406,6 @@ interface Database<T> {
 	Collection<MessageId> getMessageIds(T txn, GroupId g, Metadata query)
 			throws DbException;
 
-	/**
-	 * Returns the length of the given message in bytes, including the
-	 * message header.
-	 */
-	int getMessageLength(T txn, MessageId m) throws DbException;
-
 	/**
 	 * Returns the metadata for all delivered messages in the given group.
 	 * <p/>
@@ -519,8 +496,7 @@ interface Database<T> {
 
 	/**
 	 * Returns the IDs of some messages that are eligible to be sent to the
-	 * given contact. The total length of the messages including record headers
+	 * given contact, up to the given total length.
-	 * will be no more than the given capacity.
 	 * <p/>
 	 * Unlike {@link #getUnackedMessagesToSend(Object, ContactId)} this method
 	 * does not return messages that have already been sent unless they are
@@ -528,20 +504,20 @@ interface Database<T> {
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getMessagesToSend(T txn, ContactId c, long capacity,
+	Collection<MessageId> getMessagesToSend(T txn, ContactId c, int maxLength,
 			long maxLatency) throws DbException;
 
 	/**
 	 * Returns the IDs of all messages that are eligible to be sent to the
-	 * given contact.
+	 * given contact, together with their raw lengths.
 	 * <p/>
-	 * Unlike {@link #getMessagesToSend(Object, ContactId, long, long)} this
+	 * Unlike {@link #getMessagesToSend(Object, ContactId, int, long)} this
 	 * method may return messages that have already been sent and are not yet
 	 * due for retransmission.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getUnackedMessagesToSend(T txn, ContactId c)
+	Map<MessageId, Integer> getUnackedMessagesToSend(T txn, ContactId c)
 			throws DbException;
 
 	/**
@@ -597,16 +573,13 @@ interface Database<T> {
 
 	/**
 	 * Returns the next time (in milliseconds since the Unix epoch) when a
-	 * message is due to be sent to the given contact over a transport with
+	 * message is due to be sent to the given contact. The returned value may
-	 * the given latency.
+	 * be zero if a message is due to be sent immediately, or Long.MAX_VALUE
-	 * <p>
+	 * if no messages are scheduled to be sent.
-	 * The returned value may be zero if a message is due to be sent
-	 * immediately, or Long.MAX_VALUE if no messages are scheduled to be sent.
 	 * <p/>
 	 * Read-only.
 	 */
-	long getNextSendTime(T txn, ContactId c, long maxLatency)
+	long getNextSendTime(T txn, ContactId c) throws DbException;
-			throws DbException;
 
 	/**
 	 * Returns the pending contact with the given ID.
@@ -625,14 +598,13 @@ interface Database<T> {
 
 	/**
 	 * Returns the IDs of some messages that are eligible to be sent to the
-	 * given contact and have been requested by the contact. The total length
+	 * given contact and have been requested by the contact, up to the given
-	 * of the messages including record headers will be no more than the given
+	 * total length.
-	 * capacity.
 	 * <p/>
 	 * Read-only.
 	 */
 	Collection<MessageId> getRequestedMessagesToSend(T txn, ContactId c,
-			long capacity, long maxLatency) throws DbException;
+			int maxLength, long maxLatency) throws DbException;
 
 	/**
 	 * Returns all settings in the given namespace.
@@ -786,10 +758,9 @@ interface Database<T> {
 	void resetExpiryTime(T txn, ContactId c, MessageId m) throws DbException;
 
 	/**
-	 * Resets the transmission count, expiry time and max latency of all
+	 * Resets the transmission count, expiry time and ETA of all messages that
-	 * messages that are eligible to be sent to the given contact. This includes
+	 * are eligible to be sent to the given contact. This includes messages that
-	 * messages that have already been sent and are not yet due for
+	 * have already been sent and are not yet due for retransmission.
-	 * retransmission.
 	 */
 	void resetUnackedMessagesToSend(T txn, ContactId c) throws DbException;
 
@@ -877,13 +848,11 @@ interface Database<T> {
 	void stopCleanupTimer(T txn, MessageId m) throws DbException;
 
 	/**
-	 * Updates the transmission count, expiry time and max latency of the given
+	 * Updates the transmission count, expiry time and estimated time of arrival
-	 * message with respect to the given contact.
+	 * of the given message with respect to the given contact, using the latency
-	 *
+	 * of the transport over which it was sent.
-	 * @param maxLatency latency of the transport over which the message was
-	 * sent.
 	 */
-	void updateRetransmissionData(T txn, ContactId c, MessageId m,
+	void updateExpiryTimeAndEta(T txn, ContactId c, MessageId m,
 			long maxLatency) throws DbException;
 
 	/**

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

@@ -75,6 +75,7 @@ import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.Executor;
@@ -86,7 +87,6 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
-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.sync.Group.Visibility.INVISIBLE;
@@ -287,12 +287,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			transaction.attach(new MessageAddedEvent(m, null));
 			transaction.attach(new MessageStateChangedEvent(m.getId(), true,
 					DELIVERED));
-			if (shared) {
+			if (shared) transaction.attach(new MessageSharedEvent(m.getId()));
-				Map<ContactId, Boolean> visibility =
-						db.getGroupVisibility(txn, m.getGroupId());
-				transaction.attach(new MessageSharedEvent(m.getId(),
-						m.getGroupId(), visibility));
-			}
 		}
 		db.mergeMessageMetadata(txn, m.getId(), meta);
 	}
@@ -347,12 +342,12 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public boolean containsAcksToSend(Transaction transaction, ContactId c)
+	public boolean containsAnythingToSend(Transaction transaction, ContactId c,
-			throws DbException {
+			long maxLatency, boolean eager) throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
-		return db.containsAcksToSend(txn, c);
+		return db.containsAnythingToSend(txn, c, maxLatency, eager);
 	}
 
 	@Override
@@ -378,15 +373,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.containsIdentity(txn, a);
 	}
 
-	@Override
-	public boolean containsMessagesToSend(Transaction transaction, ContactId c,
-			long maxLatency, boolean eager) throws DbException {
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		return db.containsMessagesToSend(txn, c, maxLatency, eager);
-	}
-
 	@Override
 	public boolean containsPendingContact(Transaction transaction,
 			PendingContactId p) throws DbException {
@@ -438,27 +424,53 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	@Nullable
 	@Override
 	public Collection<Message> generateBatch(Transaction transaction,
-			ContactId c, long capacity, long maxLatency) throws DbException {
+			ContactId c, int maxLength, long maxLatency) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
 		Collection<MessageId> ids =
-				db.getMessagesToSend(txn, c, capacity, maxLatency);
+				db.getMessagesToSend(txn, c, maxLength, maxLatency);
-		if (ids.isEmpty()) return null;
 		long totalLength = 0;
 		List<Message> messages = new ArrayList<>(ids.size());
 		for (MessageId m : ids) {
 			Message message = db.getMessage(txn, m);
 			totalLength += message.getRawLength();
 			messages.add(message);
-			db.updateRetransmissionData(txn, c, m, maxLatency);
+			db.updateExpiryTimeAndEta(txn, c, m, maxLatency);
 		}
+		if (ids.isEmpty()) return null;
 		db.lowerRequestedFlag(txn, c, ids);
 		transaction.attach(new MessagesSentEvent(c, ids, totalLength));
 		return messages;
 	}
 
+	@Override
+	public Collection<Message> generateBatch(Transaction transaction,
+			ContactId c, Collection<MessageId> ids, long maxLatency)
+			throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsContact(txn, c))
+			throw new NoSuchContactException();
+		long totalLength = 0;
+		List<Message> messages = new ArrayList<>(ids.size());
+		List<MessageId> sentIds = new ArrayList<>(ids.size());
+		for (MessageId m : ids) {
+			if (db.containsVisibleMessage(txn, c, m)) {
+				Message message = db.getMessage(txn, m);
+				totalLength += message.getRawLength();
+				messages.add(message);
+				sentIds.add(m);
+				db.updateExpiryTimeAndEta(txn, c, m, maxLatency);
+			}
+		}
+		if (messages.isEmpty()) return messages;
+		db.lowerRequestedFlag(txn, c, sentIds);
+		transaction.attach(new MessagesSentEvent(c, sentIds, totalLength));
+		return messages;
+	}
+
 	@Nullable
 	@Override
 	public Offer generateOffer(Transaction transaction, ContactId c,
@@ -471,7 +483,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 				db.getMessagesToOffer(txn, c, maxMessages, maxLatency);
 		if (ids.isEmpty()) return null;
 		for (MessageId m : ids)
-			db.updateRetransmissionData(txn, c, m, maxLatency);
+			db.updateExpiryTimeAndEta(txn, c, m, maxLatency);
 		return new Offer(ids);
 	}
 
@@ -493,22 +505,22 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	@Nullable
 	@Override
 	public Collection<Message> generateRequestedBatch(Transaction transaction,
-			ContactId c, long capacity, long maxLatency) throws DbException {
+			ContactId c, int maxLength, long maxLatency) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
 		Collection<MessageId> ids =
-				db.getRequestedMessagesToSend(txn, c, capacity, maxLatency);
+				db.getRequestedMessagesToSend(txn, c, maxLength, maxLatency);
-		if (ids.isEmpty()) return null;
 		long totalLength = 0;
 		List<Message> messages = new ArrayList<>(ids.size());
 		for (MessageId m : ids) {
 			Message message = db.getMessage(txn, m);
 			totalLength += message.getRawLength();
 			messages.add(message);
-			db.updateRetransmissionData(txn, c, m, maxLatency);
+			db.updateExpiryTimeAndEta(txn, c, m, maxLatency);
 		}
+		if (ids.isEmpty()) return null;
 		db.lowerRequestedFlag(txn, c, ids);
 		transaction.attach(new MessagesSentEvent(c, ids, totalLength));
 		return messages;
@@ -555,15 +567,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getGroup(txn, g);
 	}
 
-	@Override
-	public GroupId getGroupId(Transaction transaction, MessageId m)
-			throws DbException {
-		T txn = unbox(transaction);
-		if (!db.containsMessage(txn, m))
-			throw new NoSuchMessageException();
-		return db.getGroupId(txn, m);
-	}
-
 	@Override
 	public Metadata getGroupMetadata(Transaction transaction, GroupId g)
 			throws DbException {
@@ -632,24 +635,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getMessageIds(txn, g, query);
 	}
 
-	@Override
-	public Collection<MessageId> getMessagesToAck(Transaction transaction,
-			ContactId c) throws DbException {
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		return db.getMessagesToAck(txn, c, Integer.MAX_VALUE);
-	}
-
-	@Override
-	public Collection<MessageId> getMessagesToSend(Transaction transaction,
-			ContactId c, long capacity, long maxLatency) throws DbException {
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		return db.getMessagesToSend(txn, c, capacity, maxLatency);
-	}
-
 	@Override
 	public Collection<MessageId> getMessagesToValidate(Transaction transaction)
 			throws DbException {
@@ -755,31 +740,10 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return status;
 	}
 
-	@Nullable
 	@Override
-	public Message getMessageToSend(Transaction transaction, ContactId c,
+	public Map<MessageId, Integer> getUnackedMessagesToSend(
-			MessageId m, long maxLatency, boolean markAsSent)
+			Transaction transaction,
-			throws DbException {
+			ContactId c) throws DbException {
-		if (markAsSent && transaction.isReadOnly()) {
-			throw new IllegalArgumentException();
-		}
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		if (!db.containsVisibleMessage(txn, c, m)) return null;
-		Message message = db.getMessage(txn, m);
-		if (markAsSent) {
-			db.updateRetransmissionData(txn, c, m, maxLatency);
-			db.lowerRequestedFlag(txn, c, singletonList(m));
-			transaction.attach(new MessagesSentEvent(c, singletonList(m),
-					message.getRawLength()));
-		}
-		return message;
-	}
-
-	@Override
-	public Collection<MessageId> getUnackedMessagesToSend(
-			Transaction transaction, ContactId c) throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
@@ -830,10 +794,10 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public long getNextSendTime(Transaction transaction, ContactId c,
+	public long getNextSendTime(Transaction transaction, ContactId c)
-			long maxLatency) throws DbException {
+			throws DbException {
 		T txn = unbox(transaction);
-		return db.getNextSendTime(txn, c, maxLatency);
+		return db.getNextSendTime(txn, c);
 	}
 
 	@Override
@@ -1041,8 +1005,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 				db.getGroupVisibility(txn, id).keySet();
 		db.removeGroup(txn, id);
 		transaction.attach(new GroupRemovedEvent(g));
-		transaction.attach(new GroupVisibilityUpdatedEvent(INVISIBLE,
+		transaction.attach(new GroupVisibilityUpdatedEvent(affected));
-				affected));
 	}
 
 	@Override
@@ -1106,16 +1069,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.removeTransportKeys(txn, t, k);
 	}
 
-	@Override
-	public void setAckSent(Transaction transaction, ContactId c,
-			Collection<MessageId> acked) throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		db.lowerAckFlag(txn, c, acked);
-	}
-
 	@Override
 	public void setCleanupTimerDuration(Transaction transaction, MessageId m,
 			long duration) throws DbException {
@@ -1162,8 +1115,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		if (old == INVISIBLE) db.addGroupVisibility(txn, c, g, v == SHARED);
 		else if (v == INVISIBLE) db.removeGroupVisibility(txn, c, g);
 		else db.setGroupVisibility(txn, c, g, v == SHARED);
-		List<ContactId> affected = singletonList(c);
+		List<ContactId> affected = Collections.singletonList(c);
-		transaction.attach(new GroupVisibilityUpdatedEvent(v, affected));
+		transaction.attach(new GroupVisibilityUpdatedEvent(affected));
 	}
 
 	@Override
@@ -1196,9 +1149,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		if (db.getMessageState(txn, m) != DELIVERED)
 			throw new IllegalArgumentException("Shared undelivered message");
 		db.setMessageShared(txn, m, true);
-		GroupId g = db.getGroupId(txn, m);
+		transaction.attach(new MessageSharedEvent(m));
-		Map<ContactId, Boolean> visibility = db.getGroupVisibility(txn, g);
-		transaction.attach(new MessageSharedEvent(m, g, visibility));
 	}
 
 	@Override
@@ -1212,28 +1163,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		transaction.attach(new MessageStateChangedEvent(m, false, state));
 	}
 
-	@Override
-	public void setMessagesSent(Transaction transaction, ContactId c,
-			Collection<MessageId> sent, long maxLatency) throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		long totalLength = 0;
-		List<MessageId> visible = new ArrayList<>(sent.size());
-		for (MessageId m : sent) {
-			if (db.containsVisibleMessage(txn, c, m)) {
-				visible.add(m);
-				totalLength += db.getMessageLength(txn, m);
-				db.updateRetransmissionData(txn, c, m, maxLatency);
-			}
-		}
-		db.lowerRequestedFlag(txn, c, visible);
-		if (!visible.isEmpty()) {
-			transaction.attach(new MessagesSentEvent(c, visible, totalLength));
-		}
-	}
-
 	@Override
 	public void addMessageDependencies(Transaction transaction,
 			Message dependent, Collection<MessageId> dependencies)

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

@@ -2,6 +2,8 @@ package org.briarproject.bramble.db;
 
 import org.briarproject.bramble.api.settings.Settings;
 
+import static java.util.concurrent.TimeUnit.DAYS;
+
 interface DatabaseConstants {
 
 	/**
@@ -23,6 +25,19 @@ interface DatabaseConstants {
 	 */
 	String SCHEMA_VERSION_KEY = "schemaVersion";
 
+	/**
+	 * The {@link Settings} key under which the time of the last database
+	 * compaction is stored.
+	 */
+	String LAST_COMPACTED_KEY = "lastCompacted";
+
+	/**
+	 * The maximum time between database compactions in milliseconds. When the
+	 * database is opened it will be compacted if more than this amount of time
+	 * has passed since the last compaction.
+	 */
+	long MAX_COMPACTION_INTERVAL_MS = DAYS.toMillis(30);
+
 	/**
 	 * The {@link Settings} key under which the flag is stored indicating
 	 * whether the database is marked as dirty.

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

@@ -85,17 +85,12 @@ class H2Database extends JdbcDatabase {
 	public void close() throws DbException {
 		// H2 will close the database when the last connection closes
 		Connection c = null;
-		Statement s = null;
 		try {
 			c = createConnection();
-			closeAllConnections();
+			super.closeAllConnections();
 			setDirty(c, false);
-			s = c.createStatement();
-			s.execute("SHUTDOWN COMPACT");
-			s.close();
 			c.close();
 		} catch (SQLException e) {
-			tryToClose(s, LOG, WARNING);
 			tryToClose(c, LOG, WARNING);
 			throw new DbException(e);
 		}

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

@@ -79,11 +79,11 @@ class HyperSqlDatabase extends JdbcDatabase {
 		Connection c = null;
 		Statement s = null;
 		try {
-			closeAllConnections();
+			super.closeAllConnections();
 			c = createConnection();
 			setDirty(c, false);
 			s = c.createStatement();
-			s.executeQuery("SHUTDOWN COMPACT");
+			s.executeQuery("SHUTDOWN");
 			s.close();
 			c.close();
 		} catch (SQLException e) {
@@ -106,7 +106,7 @@ class HyperSqlDatabase extends JdbcDatabase {
 		Connection c = null;
 		Statement s = null;
 		try {
-			closeAllConnections();
+			super.closeAllConnections();
 			c = createConnection();
 			s = c.createStatement();
 			s.executeQuery("SHUTDOWN COMPACT");

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

@@ -51,6 +51,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.LinkedHashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
@@ -69,14 +70,12 @@ import static java.sql.Types.BOOLEAN;
 import static java.sql.Types.INTEGER;
 import static java.sql.Types.VARCHAR;
 import static java.util.Arrays.asList;
-import static java.util.logging.Level.FINE;
 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.db.DatabaseComponent.NO_CLEANUP_DEADLINE;
 import static org.briarproject.bramble.api.db.DatabaseComponent.TIMER_NOT_STARTED;
 import static org.briarproject.bramble.api.db.Metadata.REMOVE;
-import static org.briarproject.bramble.api.record.Record.RECORD_HEADER_BYTES;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
@@ -86,6 +85,8 @@ import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
 import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
 import static org.briarproject.bramble.db.DatabaseConstants.DB_SETTINGS_NAMESPACE;
 import static org.briarproject.bramble.db.DatabaseConstants.DIRTY_KEY;
+import static org.briarproject.bramble.db.DatabaseConstants.LAST_COMPACTED_KEY;
+import static org.briarproject.bramble.db.DatabaseConstants.MAX_COMPACTION_INTERVAL_MS;
 import static org.briarproject.bramble.db.DatabaseConstants.SCHEMA_VERSION_KEY;
 import static org.briarproject.bramble.db.ExponentialBackoff.calculateExpiry;
 import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
@@ -101,12 +102,7 @@ import static org.briarproject.bramble.util.LogUtils.now;
 abstract class JdbcDatabase implements Database<Connection> {
 
 	// Package access for testing
-	static final int CODE_SCHEMA_VERSION = 50;
+	static final int CODE_SCHEMA_VERSION = 49;
-
-	/**
-	 * The maximum number of idle connections to keep open.
-	 */
-	private static final int MAX_CONNECTION_POOL_SIZE = 1;
 
 	// Time period offsets for incoming transport keys
 	private static final int OFFSET_PREV = -1;
@@ -256,7 +252,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " requested BOOLEAN NOT NULL,"
 					+ " expiry BIGINT NOT NULL,"
 					+ " txCount INT NOT NULL,"
-					+ " maxLatency BIGINT," // Null if latency was reset
+					+ " eta BIGINT NOT NULL,"
 					+ " PRIMARY KEY (messageId, contactId),"
 					+ " FOREIGN KEY (messageId)"
 					+ " REFERENCES messages (messageId)"
@@ -369,7 +365,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private final Condition connectionsChanged = connectionsLock.newCondition();
 
 	@GuardedBy("connectionsLock")
-	private final LinkedList<Connection> connectionPool = new LinkedList<>();
+	private final LinkedList<Connection> connections = new LinkedList<>();
 
 	@GuardedBy("connectionsLock")
 	private int openConnections = 0;
@@ -382,7 +378,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 			throws DbException, SQLException;
 
 	// Used exclusively during open to compact the database after schema
-	// migrations or if the database was not shut down cleanly
+	// migrations or after DatabaseConstants#MAX_COMPACTION_INTERVAL_MS has
+	// elapsed
 	protected abstract void compactAndClose() throws DbException;
 
 	JdbcDatabase(DatabaseTypes databaseTypes, MessageFactory messageFactory,
@@ -408,8 +405,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (reopen) {
 				Settings s = getSettings(txn, DB_SETTINGS_NAMESPACE);
 				wasDirtyOnInitialisation = isDirty(s);
-				boolean migrated = migrateSchema(txn, s, listener);
+				compact = migrateSchema(txn, s, listener) || isCompactionDue(s);
-				compact = wasDirtyOnInitialisation || migrated;
 			} else {
 				wasDirtyOnInitialisation = false;
 				createTables(txn);
@@ -439,6 +435,14 @@ abstract class JdbcDatabase implements Database<Connection> {
 			} finally {
 				connectionsLock.unlock();
 			}
+			txn = startTransaction();
+			try {
+				storeLastCompacted(txn);
+				commitTransaction(txn);
+			} catch (DbException e) {
+				abortTransaction(txn);
+				throw e;
+			}
 		}
 	}
 
@@ -498,11 +502,18 @@ abstract class JdbcDatabase implements Database<Connection> {
 				new Migration45_46(),
 				new Migration46_47(dbTypes),
 				new Migration47_48(),
-				new Migration48_49(),
+				new Migration48_49()
-				new Migration49_50()
 		);
 	}
 
+	private boolean isCompactionDue(Settings s) {
+		long lastCompacted = s.getLong(LAST_COMPACTED_KEY, 0);
+		long elapsed = clock.currentTimeMillis() - lastCompacted;
+		if (LOG.isLoggable(INFO))
+			LOG.info(elapsed + " ms since last compaction");
+		return elapsed > MAX_COMPACTION_INTERVAL_MS;
+	}
+
 	private void storeSchemaVersion(Connection txn, int version)
 			throws DbException {
 		Settings s = new Settings();
@@ -510,6 +521,12 @@ abstract class JdbcDatabase implements Database<Connection> {
 		mergeSettings(txn, s, DB_SETTINGS_NAMESPACE);
 	}
 
+	private void storeLastCompacted(Connection txn) throws DbException {
+		Settings s = new Settings();
+		s.putLong(LAST_COMPACTED_KEY, clock.currentTimeMillis());
+		mergeSettings(txn, s, DB_SETTINGS_NAMESPACE);
+	}
+
 	private boolean isDirty(Settings s) {
 		return s.getBoolean(DIRTY_KEY, false);
 	}
@@ -523,6 +540,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private void initialiseSettings(Connection txn) throws DbException {
 		Settings s = new Settings();
 		s.putInt(SCHEMA_VERSION_KEY, CODE_SCHEMA_VERSION);
+		s.putLong(LAST_COMPACTED_KEY, clock.currentTimeMillis());
 		mergeSettings(txn, s, DB_SETTINGS_NAMESPACE);
 	}
 
@@ -577,8 +595,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		connectionsLock.lock();
 		try {
 			if (closed) throw new DbClosedException();
-			txn = connectionPool.poll();
+			txn = connections.poll();
-			logConnectionCounts();
 		} finally {
 			connectionsLock.unlock();
 		}
@@ -589,14 +606,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				txn.setAutoCommit(false);
 				connectionsLock.lock();
 				try {
-					// The DB may have been closed since the check above
-					if (closed) {
-						tryToClose(txn, LOG, WARNING);
-						throw new DbClosedException();
-					}
 					openConnections++;
-					logConnectionCounts();
-					connectionsChanged.signalAll();
 				} finally {
 					connectionsLock.unlock();
 				}
@@ -607,91 +617,67 @@ abstract class JdbcDatabase implements Database<Connection> {
 		return txn;
 	}
 
-	@GuardedBy("connectionsLock")
-	private void logConnectionCounts() {
-		if (LOG.isLoggable(FINE)) {
-			LOG.fine(openConnections + " connections open, "
-					+ connectionPool.size() + " in pool");
-		}
-	}
-
 	@Override
 	public void abortTransaction(Connection txn) {
-		// The transaction may have been aborted due to an earlier exception,
-		// so close the connection rather than returning it to the pool
 		try {
 			txn.rollback();
+			connectionsLock.lock();
+			try {
+				connections.add(txn);
+				connectionsChanged.signalAll();
+			} finally {
+				connectionsLock.unlock();
+			}
 		} catch (SQLException e) {
+			// Try to close the connection
 			logException(LOG, WARNING, e);
-		}
+			tryToClose(txn, LOG, WARNING);
-		closeConnection(txn);
+			// Whatever happens, allow the database to close
-	}
+			connectionsLock.lock();
-
+			try {
-	private void closeConnection(Connection txn) {
+				openConnections--;
-		tryToClose(txn, LOG, WARNING);
+				connectionsChanged.signalAll();
-		connectionsLock.lock();
+			} finally {
-		try {
+				connectionsLock.unlock();
-			openConnections--;
+			}
-			logConnectionCounts();
-			connectionsChanged.signalAll();
-		} finally {
-			connectionsLock.unlock();
 		}
 	}
 
 	@Override
 	public void commitTransaction(Connection txn) throws DbException {
-		// If the transaction commits successfully then return the connection
-		// to the pool, otherwise close it
 		try {
 			txn.commit();
-			returnConnectionToPool(txn);
 		} catch (SQLException e) {
-			logException(LOG, WARNING, e);
-			closeConnection(txn);
 			throw new DbException(e);
 		}
-	}
-
-	private void returnConnectionToPool(Connection txn) {
-		boolean shouldClose;
 		connectionsLock.lock();
 		try {
-			shouldClose = connectionPool.size() >= MAX_CONNECTION_POOL_SIZE;
+			connections.add(txn);
-			if (shouldClose) openConnections--;
-			else connectionPool.add(txn);
-			logConnectionCounts();
 			connectionsChanged.signalAll();
 		} finally {
 			connectionsLock.unlock();
 		}
-		if (shouldClose) tryToClose(txn, LOG, WARNING);
 	}
 
-	void closeAllConnections() {
+	void closeAllConnections() throws SQLException {
 		boolean interrupted = false;
 		connectionsLock.lock();
 		try {
 			closed = true;
-			for (Connection c : connectionPool) tryToClose(c, LOG, WARNING);
+			for (Connection c : connections) c.close();
-			openConnections -= connectionPool.size();
+			openConnections -= connections.size();
-			connectionPool.clear();
+			connections.clear();
 			while (openConnections > 0) {
-				if (LOG.isLoggable(INFO)) {
-					LOG.info("Waiting for " + openConnections
-							+ " connections to be closed");
-				}
 				try {
 					connectionsChanged.await();
 				} catch (InterruptedException e) {
 					LOG.warning("Interrupted while closing connections");
 					interrupted = true;
 				}
-				for (Connection c : connectionPool) tryToClose(c, LOG, WARNING);
+				for (Connection c : connections) c.close();
-				openConnections -= connectionPool.size();
+				openConnections -= connections.size();
-				connectionPool.clear();
+				connections.clear();
 			}
-			LOG.info("All connections closed");
 		} finally {
 			connectionsLock.unlock();
 		}
@@ -934,10 +920,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 		try {
 			String sql = "INSERT INTO statuses (messageId, contactId, groupId,"
 					+ " timestamp, length, state, groupShared, messageShared,"
-					+ " deleted, ack, seen, requested, expiry, txCount,"
+					+ " deleted, ack, seen, requested, expiry, txCount, eta)"
-					+ " maxLatency)"
 					+ " VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, FALSE, 0, 0,"
-					+ " NULL)";
+					+ " 0)";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
 			ps.setInt(2, c.getInt());
@@ -1147,8 +1132,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public boolean containsAcksToSend(Connection txn, ContactId c)
+	public boolean containsAnythingToSend(Connection txn, ContactId c,
-			throws DbException {
+			long maxLatency, boolean eager) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
@@ -1160,7 +1145,34 @@ abstract class JdbcDatabase implements Database<Connection> {
 			boolean acksToSend = rs.next();
 			rs.close();
 			ps.close();
-			return acksToSend;
+			if (acksToSend) return true;
+			if (eager) {
+				sql = "SELECT NULL from statuses"
+						+ " WHERE contactId = ? AND state = ?"
+						+ " AND groupShared = TRUE AND messageShared = TRUE"
+						+ " AND deleted = FALSE AND seen = FALSE";
+				ps = txn.prepareStatement(sql);
+				ps.setInt(1, c.getInt());
+				ps.setInt(2, DELIVERED.getValue());
+			} else {
+				long now = clock.currentTimeMillis();
+				long eta = now + maxLatency;
+				sql = "SELECT NULL FROM statuses"
+						+ " WHERE contactId = ? AND state = ?"
+						+ " AND groupShared = TRUE AND messageShared = TRUE"
+						+ " AND deleted = FALSE AND seen = FALSE"
+						+ " AND (expiry <= ? OR eta > ?)";
+				ps = txn.prepareStatement(sql);
+				ps.setInt(1, c.getInt());
+				ps.setInt(2, DELIVERED.getValue());
+				ps.setLong(3, now);
+				ps.setLong(4, eta);
+			}
+			rs = ps.executeQuery();
+			boolean messagesToSend = rs.next();
+			rs.close();
+			ps.close();
+			return messagesToSend;
 		} catch (SQLException e) {
 			tryToClose(rs, LOG, WARNING);
 			tryToClose(ps, LOG, WARNING);
@@ -1280,46 +1292,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public boolean containsMessagesToSend(Connection txn, ContactId c,
-			long maxLatency, boolean eager) throws DbException {
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			if (eager) {
-				String sql = "SELECT NULL from statuses"
-						+ " WHERE contactId = ? AND state = ?"
-						+ " AND groupShared = TRUE AND messageShared = TRUE"
-						+ " AND deleted = FALSE AND seen = FALSE";
-				ps = txn.prepareStatement(sql);
-				ps.setInt(1, c.getInt());
-				ps.setInt(2, DELIVERED.getValue());
-			} else {
-				long now = clock.currentTimeMillis();
-				String sql = "SELECT NULL FROM statuses"
-						+ " WHERE contactId = ? AND state = ?"
-						+ " AND groupShared = TRUE AND messageShared = TRUE"
-						+ " AND deleted = FALSE AND seen = FALSE"
-						+ " AND (expiry <= ? OR maxLatency IS NULL"
-						+ " OR ? < maxLatency)";
-				ps = txn.prepareStatement(sql);
-				ps.setInt(1, c.getInt());
-				ps.setInt(2, DELIVERED.getValue());
-				ps.setLong(3, now);
-				ps.setLong(4, maxLatency);
-			}
-			rs = ps.executeQuery();
-			boolean messagesToSend = rs.next();
-			rs.close();
-			ps.close();
-			return messagesToSend;
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public boolean containsPendingContact(Connection txn, PendingContactId p)
 			throws DbException {
@@ -1683,27 +1655,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public GroupId getGroupId(Connection txn, MessageId m) throws DbException {
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			String sql = "SELECT groupId FROM messages WHERE messageId = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setBytes(1, m.getBytes());
-			rs = ps.executeQuery();
-			if (!rs.next()) throw new DbStateException();
-			GroupId g = new GroupId(rs.getBytes(1));
-			rs.close();
-			ps.close();
-			return g;
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public Collection<Group> getGroups(Connection txn, ClientId c,
 			int majorVersion) throws DbException {
@@ -1951,31 +1902,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public int getMessageLength(Connection txn, MessageId m)
-			throws DbException {
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			String sql = "SELECT length from messages"
-					+ " WHERE messageId = ? AND state = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setBytes(1, m.getBytes());
-			ps.setInt(2, DELIVERED.getValue());
-			rs = ps.executeQuery();
-			if (!rs.next()) throw new DbStateException();
-			int length = rs.getInt(1);
-			if (rs.next()) throw new DbStateException();
-			rs.close();
-			ps.close();
-			return length;
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public Map<MessageId, Metadata> getMessageMetadata(Connection txn,
 			GroupId g) throws DbException {
@@ -2268,6 +2194,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	public Collection<MessageId> getMessagesToOffer(Connection txn,
 			ContactId c, int maxMessages, long maxLatency) throws DbException {
 		long now = clock.currentTimeMillis();
+		long eta = now + maxLatency;
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
@@ -2276,14 +2203,13 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " AND groupShared = TRUE AND messageShared = TRUE"
 					+ " AND deleted = FALSE"
 					+ " AND seen = FALSE AND requested = FALSE"
-					+ " AND (expiry <= ? OR maxLatency IS NULL"
+					+ " AND (expiry <= ? OR eta > ?)"
-					+ " OR ? < maxLatency)"
 					+ " ORDER BY timestamp LIMIT ?";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
 			ps.setInt(2, DELIVERED.getValue());
 			ps.setLong(3, now);
-			ps.setLong(4, maxLatency);
+			ps.setLong(4, eta);
 			ps.setInt(5, maxMessages);
 			rs = ps.executeQuery();
 			List<MessageId> ids = new ArrayList<>();
@@ -2324,9 +2250,10 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public Collection<MessageId> getMessagesToSend(Connection txn,
+	public Collection<MessageId> getMessagesToSend(Connection txn, ContactId c,
-			ContactId c, long capacity, long maxLatency) throws DbException {
+			int maxLength, long maxLatency) throws DbException {
 		long now = clock.currentTimeMillis();
+		long eta = now + maxLatency;
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
@@ -2335,21 +2262,21 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " AND groupShared = TRUE AND messageShared = TRUE"
 					+ " AND deleted = FALSE"
 					+ " AND seen = FALSE"
-					+ " AND (expiry <= ? OR maxLatency IS NULL"
+					+ " AND (expiry <= ? OR eta > ?)"
-					+ " OR ? < maxLatency)"
 					+ " ORDER BY timestamp";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
 			ps.setInt(2, DELIVERED.getValue());
 			ps.setLong(3, now);
-			ps.setLong(4, maxLatency);
+			ps.setLong(4, eta);
 			rs = ps.executeQuery();
 			List<MessageId> ids = new ArrayList<>();
+			int total = 0;
 			while (rs.next()) {
 				int length = rs.getInt(1);
-				if (capacity < RECORD_HEADER_BYTES + length) break;
+				if (total + length > maxLength) break;
 				ids.add(new MessageId(rs.getBytes(2)));
-				capacity -= RECORD_HEADER_BYTES + length;
+				total += length;
 			}
 			rs.close();
 			ps.close();
@@ -2362,12 +2289,12 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public Collection<MessageId> getUnackedMessagesToSend(Connection txn,
+	public Map<MessageId, Integer> getUnackedMessagesToSend(Connection txn,
 			ContactId c) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT messageId FROM statuses"
+			String sql = "SELECT length, messageId FROM statuses"
 					+ " WHERE contactId = ? AND state = ?"
 					+ " AND groupShared = TRUE AND messageShared = TRUE"
 					+ " AND deleted = FALSE AND seen = FALSE"
@@ -2376,11 +2303,15 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(1, c.getInt());
 			ps.setInt(2, DELIVERED.getValue());
 			rs = ps.executeQuery();
-			List<MessageId> ids = new ArrayList<>();
+			Map<MessageId, Integer> results = new LinkedHashMap<>();
-			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
+			while (rs.next()) {
+				int length = rs.getInt(1);
+				MessageId id = new MessageId(rs.getBytes(2));
+				results.put(id, length);
+			}
 			rs.close();
 			ps.close();
-			return ids;
+			return results;
 		} catch (SQLException e) {
 			tryToClose(rs, LOG, WARNING);
 			tryToClose(ps, LOG, WARNING);
@@ -2493,7 +2424,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 				MessageId m = new MessageId(rs.getBytes(1));
 				GroupId g = new GroupId(rs.getBytes(2));
 				Collection<MessageId> messageIds = ids.get(g);
-				//noinspection Java8MapApi
 				if (messageIds == null) {
 					messageIds = new ArrayList<>();
 					ids.put(g, messageIds);
@@ -2511,28 +2441,12 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public long getNextSendTime(Connection txn, ContactId c, long maxLatency)
+	public long getNextSendTime(Connection txn, ContactId c)
 			throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			// Are any messages sendable immediately?
+			String sql = "SELECT expiry FROM statuses"
-			String sql = "SELECT NULL FROM statuses"
-					+ " WHERE contactId = ? AND state = ?"
-					+ " AND groupShared = TRUE AND messageShared = TRUE"
-					+ " AND deleted = FALSE AND seen = FALSE"
-					+ " AND (maxLatency IS NULL OR ? < maxLatency)";
-			ps = txn.prepareStatement(sql);
-			ps.setInt(1, c.getInt());
-			ps.setInt(2, DELIVERED.getValue());
-			ps.setLong(3, maxLatency);
-			rs = ps.executeQuery();
-			boolean found = rs.next();
-			rs.close();
-			ps.close();
-			if (found) return 0;
-			// When is the earliest expiry time (could be in the past)?
-			sql = "SELECT expiry FROM statuses"
 					+ " WHERE contactId = ? AND state = ?"
 					+ " AND groupShared = TRUE AND messageShared = TRUE"
 					+ " AND deleted = FALSE AND seen = FALSE"
@@ -2636,8 +2550,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	@Override
 	public Collection<MessageId> getRequestedMessagesToSend(Connection txn,
-			ContactId c, long capacity, long maxLatency) throws DbException {
+			ContactId c, int maxLength, long maxLatency) throws DbException {
 		long now = clock.currentTimeMillis();
+		long eta = now + maxLatency;
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
@@ -2646,21 +2561,21 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " AND groupShared = TRUE AND messageShared = TRUE"
 					+ " AND deleted = FALSE"
 					+ " AND seen = FALSE AND requested = TRUE"
-					+ " AND (expiry <= ? OR maxLatency IS NULL"
+					+ " AND (expiry <= ? OR eta > ?)"
-					+ " OR ? < maxLatency)"
 					+ " ORDER BY timestamp";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
 			ps.setInt(2, DELIVERED.getValue());
 			ps.setLong(3, now);
-			ps.setLong(4, maxLatency);
+			ps.setLong(4, eta);
 			rs = ps.executeQuery();
 			List<MessageId> ids = new ArrayList<>();
+			int total = 0;
 			while (rs.next()) {
 				int length = rs.getInt(1);
-				if (capacity < RECORD_HEADER_BYTES + length) break;
+				if (total + length > maxLength) break;
 				ids.add(new MessageId(rs.getBytes(2)));
-				capacity -= RECORD_HEADER_BYTES + length;
+				total += length;
 			}
 			rs.close();
 			ps.close();
@@ -2814,7 +2729,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 				ContactId c = new ContactId(rs.getInt(1));
 				TransportId t = new TransportId(rs.getString(2));
 				Collection<TransportId> transportIds = ids.get(c);
-				//noinspection Java8MapApi
 				if (transportIds == null) {
 					transportIds = new ArrayList<>();
 					ids.put(c, transportIds);
@@ -3384,8 +3298,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			throws DbException {
 		PreparedStatement ps = null;
 		try {
-			String sql = "UPDATE statuses SET expiry = 0, txCount = 0,"
+			String sql = "UPDATE statuses SET expiry = 0, txCount = 0, eta = 0"
-					+ " maxLatency = NULL"
 					+ " WHERE contactId = ? AND state = ?"
 					+ " AND groupShared = TRUE AND messageShared = TRUE"
 					+ " AND deleted = FALSE AND seen = FALSE";
@@ -3730,8 +3643,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public void updateRetransmissionData(Connection txn, ContactId c,
+	public void updateExpiryTimeAndEta(Connection txn, ContactId c, MessageId m,
-			MessageId m, long maxLatency) throws DbException {
+			long maxLatency) throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
@@ -3747,12 +3660,13 @@ abstract class JdbcDatabase implements Database<Connection> {
 			rs.close();
 			ps.close();
 			sql = "UPDATE statuses"
-					+ " SET expiry = ?, txCount = txCount + 1, maxLatency = ?"
+					+ " SET expiry = ?, txCount = txCount + 1, eta = ?"
 					+ " WHERE messageId = ? AND contactId = ?";
 			ps = txn.prepareStatement(sql);
 			long now = clock.currentTimeMillis();
+			long eta = now + maxLatency;
 			ps.setLong(1, calculateExpiry(now, maxLatency, txCount));
-			ps.setLong(2, maxLatency);
+			ps.setLong(2, eta);
 			ps.setBytes(3, m.getBytes());
 			ps.setInt(4, c.getInt());
 			int affected = ps.executeUpdate();

bramble-core/src/main/java/org/briarproject/bramble/db/Migration49_50.java

@@ -1,45 +0,0 @@
-package org.briarproject.bramble.db;
-
-import org.briarproject.bramble.api.db.DbException;
-
-import java.sql.Connection;
-import java.sql.SQLException;
-import java.sql.Statement;
-import java.util.logging.Logger;
-
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
-
-class Migration49_50 implements Migration<Connection> {
-
-	private static final Logger LOG = getLogger(Migration49_50.class.getName());
-
-	@Override
-	public int getStartVersion() {
-		return 49;
-	}
-
-	@Override
-	public int getEndVersion() {
-		return 50;
-	}
-
-	@Override
-	public void migrate(Connection txn) throws DbException {
-		Statement s = null;
-		try {
-			s = txn.createStatement();
-			s.execute("ALTER TABLE statuses"
-					+ " ALTER COLUMN eta"
-					+ " RENAME TO maxLatency");
-			s.execute("ALTER TABLE statuses"
-					+ " ALTER COLUMN maxLatency"
-					+ " SET NULL");
-			s.execute("UPDATE statuses SET maxLatency = NULL");
-		} catch (SQLException e) {
-			tryToClose(s, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-}

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

@@ -1,10 +1,10 @@
 package org.briarproject.bramble.io;
 
-import org.briarproject.bramble.api.Cancellable;
 import org.briarproject.bramble.api.io.TimeoutMonitor;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 import org.briarproject.bramble.api.system.Wakeful;
 
 import java.io.IOException;

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

@@ -18,7 +18,7 @@ import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
-import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.Semaphore;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.ThreadSafe;
@@ -29,12 +29,10 @@ 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.lifecycle.LifecycleManager.LifecycleState.COMPACTING_DATABASE;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.CREATED;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.MIGRATING_DATABASE;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.RUNNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STARTING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STARTING_SERVICES;
-import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPED;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.ALREADY_RUNNING;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.StartResult.CLOCK_ERROR;
@@ -62,11 +60,12 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 	private final List<Service> services;
 	private final List<OpenDatabaseHook> openDatabaseHooks;
 	private final List<ExecutorService> executors;
+	private final Semaphore startStopSemaphore = new Semaphore(1);
 	private final CountDownLatch dbLatch = new CountDownLatch(1);
 	private final CountDownLatch startupLatch = new CountDownLatch(1);
 	private final CountDownLatch shutdownLatch = new CountDownLatch(1);
-	private final AtomicReference<LifecycleState> state =
+
-			new AtomicReference<>(CREATED);
+	private volatile LifecycleState state = STARTING;
 
 	@Inject
 	LifecycleManagerImpl(DatabaseComponent db, EventBus eventBus,
@@ -103,8 +102,8 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 
 	@Override
 	public StartResult startServices(SecretKey dbKey) {
-		if (!state.compareAndSet(CREATED, STARTING)) {
+		if (!startStopSemaphore.tryAcquire()) {
-			LOG.warning("Already running");
+			LOG.info("Already starting or stopping");
 			return ALREADY_RUNNING;
 		}
 		long now = clock.currentTimeMillis();
@@ -136,7 +135,7 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 			});
 
 			LOG.info("Starting services");
-			state.set(STARTING_SERVICES);
+			state = STARTING_SERVICES;
 			dbLatch.countDown();
 			eventBus.broadcast(new LifecycleEvent(STARTING_SERVICES));
 
@@ -149,7 +148,7 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 				}
 			}
 
-			state.set(RUNNING);
+			state = RUNNING;
 			startupLatch.countDown();
 			eventBus.broadcast(new LifecycleEvent(RUNNING));
 			return SUCCESS;
@@ -165,58 +164,59 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 		} catch (ServiceException e) {
 			logException(LOG, WARNING, e);
 			return SERVICE_ERROR;
+		} finally {
+			startStopSemaphore.release();
 		}
 	}
 
 	@Override
 	public void onDatabaseMigration() {
-		state.set(MIGRATING_DATABASE);
+		state = MIGRATING_DATABASE;
 		eventBus.broadcast(new LifecycleEvent(MIGRATING_DATABASE));
 	}
 
 	@Override
 	public void onDatabaseCompaction() {
-		state.set(COMPACTING_DATABASE);
+		state = COMPACTING_DATABASE;
 		eventBus.broadcast(new LifecycleEvent(COMPACTING_DATABASE));
 	}
 
 	@Override
 	public void stopServices() {
-		if (!state.compareAndSet(RUNNING, STOPPING)) {
+		try {
-			LOG.warning("Not running");
+			startStopSemaphore.acquire();
+		} catch (InterruptedException e) {
+			LOG.warning("Interrupted while waiting to stop services");
 			return;
 		}
-		LOG.info("Stopping services");
+		try {
-		eventBus.broadcast(new LifecycleEvent(STOPPING));
+			LOG.info("Stopping services");
-		for (Service s : services) {
+			state = STOPPING;
-			try {
+			eventBus.broadcast(new LifecycleEvent(STOPPING));
+			for (Service s : services) {
 				long start = now();
 				s.stopService();
 				if (LOG.isLoggable(FINE)) {
 					logDuration(LOG, "Stopping service "
 							+ s.getClass().getSimpleName(), start);
 				}
-			} catch (ServiceException e) {
-				logException(LOG, WARNING, e);
 			}
-		}
+			for (ExecutorService e : executors) {
-		for (ExecutorService e : executors) {
+				if (LOG.isLoggable(FINE)) {
-			if (LOG.isLoggable(FINE)) {
+					LOG.fine("Stopping executor "
-				LOG.fine("Stopping executor "
+							+ e.getClass().getSimpleName());
-						+ e.getClass().getSimpleName());
+				}
+				e.shutdownNow();
 			}
-			e.shutdownNow();
-		}
-		try {
 			long start = now();
 			db.close();
 			logDuration(LOG, "Closing database", start);
-		} catch (DbException e) {
+			shutdownLatch.countDown();
+		} catch (DbException | ServiceException e) {
 			logException(LOG, WARNING, e);
+		} finally {
+			startStopSemaphore.release();
 		}
-		state.set(STOPPED);
-		shutdownLatch.countDown();
-		eventBus.broadcast(new LifecycleEvent(STOPPED));
 	}
 
 	@Override
@@ -236,6 +236,6 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 
 	@Override
 	public LifecycleState getLifecycleState() {
-		return state.get();
+		return state;
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ApiCall.java

@@ -1,21 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
-
-/**
- * An interface for calling an API endpoint with the option to retry the call.
- */
-interface ApiCall {
-
-	/**
-	 * This method makes a synchronous call to an API endpoint and returns
-	 * true if the call should be retried, in which case the method may be
-	 * called again on the same {@link ApiCall} instance after a delay.
-	 *
-	 * @return True if the API call needs to be retried, or false if the API
-	 * call succeeded or {@link TolerableFailureException failed tolerably}.
-	 */
-	@IoExecutor
-	boolean callApi();
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ConnectivityChecker.java

@@ -1,43 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-/**
- * An interface for checking whether a mailbox is reachable.
- */
-@ThreadSafe
-@NotNullByDefault
-interface ConnectivityChecker {
-
-	/**
-	 * Destroys the checker. Any current connectivity check is cancelled.
-	 */
-	void destroy();
-
-	/**
-	 * Starts a connectivity check if needed and calls the given observer when
-	 * the check succeeds. If a check is already running then the observer is
-	 * called when the check succeeds. If a connectivity check has recently
-	 * succeeded then the observer is called immediately.
-	 * <p>
-	 * Observers are removed after being called, or when the checker is
-	 * {@link #destroy() destroyed}.
-	 */
-	void checkConnectivity(MailboxProperties properties,
-			ConnectivityObserver o);
-
-	/**
-	 * Removes an observer that was added via
-	 * {@link #checkConnectivity(MailboxProperties, ConnectivityObserver)}. If
-	 * there are no remaining observers and a connectivity check is running
-	 * then the check will be cancelled.
-	 */
-	void removeObserver(ConnectivityObserver o);
-
-	interface ConnectivityObserver {
-		void onConnectivityCheckSucceeded();
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ConnectivityCheckerImpl.java

@@ -1,122 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.Clock;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-
-@ThreadSafe
-@NotNullByDefault
-abstract class ConnectivityCheckerImpl implements ConnectivityChecker {
-
-	/**
-	 * If no more than this much time has elapsed since the last connectivity
-	 * check succeeded, consider the result to be fresh and don't check again.
-	 * <p>
-	 * Package access for testing.
-	 */
-	static final long CONNECTIVITY_CHECK_FRESHNESS_MS = 10_000;
-
-	private final Object lock = new Object();
-
-	protected final Clock clock;
-	private final MailboxApiCaller mailboxApiCaller;
-
-	@GuardedBy("lock")
-	private boolean destroyed = false;
-
-	@GuardedBy("lock")
-	@Nullable
-	private Cancellable connectivityCheck = null;
-
-	@GuardedBy("lock")
-	private long lastConnectivityCheckSucceeded = 0;
-
-	@GuardedBy("lock")
-	private final List<ConnectivityObserver> connectivityObservers =
-			new ArrayList<>();
-
-	/**
-	 * Creates an {@link ApiCall} for checking whether the mailbox is
-	 * reachable. The {@link ApiCall} should call
-	 * {@link #onConnectivityCheckSucceeded(long)} if the check succeeds.
-	 */
-	abstract ApiCall createConnectivityCheckTask(MailboxProperties properties);
-
-	ConnectivityCheckerImpl(Clock clock, MailboxApiCaller mailboxApiCaller) {
-		this.clock = clock;
-		this.mailboxApiCaller = mailboxApiCaller;
-	}
-
-	@Override
-	public void destroy() {
-		synchronized (lock) {
-			destroyed = true;
-			connectivityObservers.clear();
-			if (connectivityCheck != null) {
-				connectivityCheck.cancel();
-				connectivityCheck = null;
-			}
-		}
-	}
-
-	@Override
-	public void checkConnectivity(MailboxProperties properties,
-			ConnectivityObserver o) {
-		boolean callNow = false;
-		synchronized (lock) {
-			if (destroyed) return;
-			if (connectivityCheck == null) {
-				// No connectivity check is running
-				long now = clock.currentTimeMillis();
-				if (now - lastConnectivityCheckSucceeded
-						> CONNECTIVITY_CHECK_FRESHNESS_MS) {
-					// The last connectivity check is stale, start a new one
-					connectivityObservers.add(o);
-					ApiCall task = createConnectivityCheckTask(properties);
-					connectivityCheck = mailboxApiCaller.retryWithBackoff(task);
-				} else {
-					// The last connectivity check is fresh
-					callNow = true;
-				}
-			} else {
-				// A connectivity check is running, wait for it to succeed
-				connectivityObservers.add(o);
-			}
-		}
-		if (callNow) o.onConnectivityCheckSucceeded();
-	}
-
-	protected void onConnectivityCheckSucceeded(long now) {
-		List<ConnectivityObserver> observers;
-		synchronized (lock) {
-			if (destroyed) return;
-			connectivityCheck = null;
-			lastConnectivityCheckSucceeded = now;
-			observers = new ArrayList<>(connectivityObservers);
-			connectivityObservers.clear();
-		}
-		for (ConnectivityObserver o : observers) {
-			o.onConnectivityCheckSucceeded();
-		}
-	}
-
-	@Override
-	public void removeObserver(ConnectivityObserver o) {
-		synchronized (lock) {
-			if (destroyed) return;
-			connectivityObservers.remove(o);
-			if (connectivityObservers.isEmpty() && connectivityCheck != null) {
-				connectivityCheck.cancel();
-				connectivityCheck = null;
-			}
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ContactMailboxClient.java

@@ -1,124 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.util.logging.Logger;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-
-import static java.util.logging.Logger.getLogger;
-
-@ThreadSafe
-@NotNullByDefault
-class ContactMailboxClient implements MailboxClient {
-
-	private static final Logger LOG =
-			getLogger(ContactMailboxClient.class.getName());
-
-	private final MailboxWorkerFactory workerFactory;
-	private final ConnectivityChecker connectivityChecker;
-	private final TorReachabilityMonitor reachabilityMonitor;
-	private final Object lock = new Object();
-
-	@GuardedBy("lock")
-	@Nullable
-	private MailboxWorker uploadWorker = null, downloadWorker = null;
-
-	ContactMailboxClient(MailboxWorkerFactory workerFactory,
-			ConnectivityChecker connectivityChecker,
-			TorReachabilityMonitor reachabilityMonitor) {
-		this.workerFactory = workerFactory;
-		this.connectivityChecker = connectivityChecker;
-		this.reachabilityMonitor = reachabilityMonitor;
-	}
-
-	@Override
-	public void start() {
-		LOG.info("Started");
-		// Nothing to do until contact is assigned
-	}
-
-	@Override
-	public void destroy() {
-		LOG.info("Destroyed");
-		MailboxWorker uploadWorker, downloadWorker;
-		synchronized (lock) {
-			uploadWorker = this.uploadWorker;
-			this.uploadWorker = null;
-			downloadWorker = this.downloadWorker;
-			this.downloadWorker = null;
-		}
-		if (uploadWorker != null) uploadWorker.destroy();
-		if (downloadWorker != null) downloadWorker.destroy();
-		// The connectivity checker belongs to the client, so it should be
-		// destroyed. The Tor reachability monitor is shared between clients,
-		// so it should not be destroyed
-		connectivityChecker.destroy();
-	}
-
-	@Override
-	public void assignContactForUpload(ContactId contactId,
-			MailboxProperties properties, MailboxFolderId folderId) {
-		LOG.info("Contact assigned for upload");
-		if (properties.isOwner()) throw new IllegalArgumentException();
-		// For a contact's mailbox we should always be uploading to the outbox
-		// assigned to us by the contact
-		if (!folderId.equals(properties.getOutboxId())) {
-			throw new IllegalArgumentException();
-		}
-		MailboxWorker uploadWorker = workerFactory.createUploadWorker(
-				connectivityChecker, properties, folderId, contactId);
-		synchronized (lock) {
-			if (this.uploadWorker != null) throw new IllegalStateException();
-			this.uploadWorker = uploadWorker;
-		}
-		uploadWorker.start();
-	}
-
-	@Override
-	public void deassignContactForUpload(ContactId contactId) {
-		LOG.info("Contact deassigned for upload");
-		MailboxWorker uploadWorker;
-		synchronized (lock) {
-			uploadWorker = this.uploadWorker;
-			this.uploadWorker = null;
-		}
-		if (uploadWorker != null) uploadWorker.destroy();
-	}
-
-	@Override
-	public void assignContactForDownload(ContactId contactId,
-			MailboxProperties properties, MailboxFolderId folderId) {
-		LOG.info("Contact assigned for download");
-		if (properties.isOwner()) throw new IllegalArgumentException();
-		// For a contact's mailbox we should always be downloading from the
-		// inbox assigned to us by the contact
-		if (!folderId.equals(properties.getInboxId())) {
-			throw new IllegalArgumentException();
-		}
-		MailboxWorker downloadWorker =
-				workerFactory.createDownloadWorkerForContactMailbox(
-						connectivityChecker, reachabilityMonitor, properties);
-		synchronized (lock) {
-			if (this.downloadWorker != null) throw new IllegalStateException();
-			this.downloadWorker = downloadWorker;
-		}
-		downloadWorker.start();
-	}
-
-	@Override
-	public void deassignContactForDownload(ContactId contactId) {
-		LOG.info("Contact deassigned for download");
-		MailboxWorker downloadWorker;
-		synchronized (lock) {
-			downloadWorker = this.downloadWorker;
-			this.downloadWorker = null;
-		}
-		if (downloadWorker != null) downloadWorker.destroy();
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ContactMailboxConnectivityChecker.java

@@ -1,43 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
-
-import java.util.logging.Logger;
-
-import javax.annotation.concurrent.ThreadSafe;
-import javax.inject.Inject;
-
-import static java.util.logging.Logger.getLogger;
-
-@ThreadSafe
-@NotNullByDefault
-class ContactMailboxConnectivityChecker extends ConnectivityCheckerImpl {
-
-	private static final Logger LOG =
-			getLogger(ContactMailboxConnectivityChecker.class.getName());
-
-	private final MailboxApi mailboxApi;
-
-	@Inject
-	ContactMailboxConnectivityChecker(Clock clock,
-			MailboxApiCaller mailboxApiCaller, MailboxApi mailboxApi) {
-		super(clock, mailboxApiCaller);
-		this.mailboxApi = mailboxApi;
-	}
-
-	@Override
-	ApiCall createConnectivityCheckTask(MailboxProperties properties) {
-		if (properties.isOwner()) throw new IllegalArgumentException();
-		return new SimpleApiCall(() -> {
-			LOG.info("Checking connectivity of contact's mailbox");
-			if (!mailboxApi.checkStatus(properties)) throw new ApiException();
-			LOG.info("Contact's mailbox is reachable");
-			// Call the observers and cache the result
-			onConnectivityCheckSucceeded(clock.currentTimeMillis());
-		});
-	}
-
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/ContactMailboxDownloadWorker.java

@@ -1,65 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.mailbox.MailboxApi.ApiException;
-import org.briarproject.bramble.mailbox.MailboxApi.MailboxFile;
-import org.briarproject.bramble.mailbox.MailboxApi.TolerableFailureException;
-
-import java.io.IOException;
-import java.util.LinkedList;
-import java.util.List;
-import java.util.Queue;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-import static java.util.Collections.emptyList;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-
-@ThreadSafe
-@NotNullByDefault
-class ContactMailboxDownloadWorker extends MailboxDownloadWorker {
-
-	ContactMailboxDownloadWorker(
-			ConnectivityChecker connectivityChecker,
-			TorReachabilityMonitor torReachabilityMonitor,
-			MailboxApiCaller mailboxApiCaller,
-			MailboxApi mailboxApi,
-			MailboxFileManager mailboxFileManager,
-			MailboxProperties mailboxProperties) {
-		super(connectivityChecker, torReachabilityMonitor, mailboxApiCaller,
-				mailboxApi, mailboxFileManager, mailboxProperties);
-		if (mailboxProperties.isOwner()) throw new IllegalArgumentException();
-	}
-
-	@Override
-	protected ApiCall createApiCallForDownloadCycle() {
-		return new SimpleApiCall(this::apiCallListInbox);
-	}
-
-	private void apiCallListInbox() throws IOException, ApiException {
-		synchronized (lock) {
-			if (state == State.DESTROYED) return;
-		}
-		LOG.info("Listing inbox");
-		MailboxFolderId folderId =
-				requireNonNull(mailboxProperties.getInboxId());
-		List<MailboxFile> files;
-		try {
-			files = mailboxApi.getFiles(mailboxProperties, folderId);
-		} catch (TolerableFailureException e) {
-			LOG.warning("Inbox folder does not exist");
-			files = emptyList();
-		}
-		if (files.isEmpty()) {
-			onDownloadCycleFinished();
-		} else {
-			Queue<FolderFile> queue = new LinkedList<>();
-			for (MailboxFile file : files) {
-				queue.add(new FolderFile(folderId, file.name));
-			}
-			downloadNextFile(queue);
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApi.java

@@ -3,27 +3,15 @@ package org.briarproject.bramble.mailbox;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.mailbox.MailboxAuthToken;
-import org.briarproject.bramble.api.mailbox.MailboxFileId;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
 import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
-import java.io.File;
 import java.io.IOException;
 import java.util.Collection;
-import java.util.List;
 
-import javax.annotation.Nonnull;
 import javax.annotation.concurrent.Immutable;
 
-@NotNullByDefault
 interface MailboxApi {
 
-	List<MailboxVersion> getServerSupports(MailboxProperties properties)
-			throws IOException, ApiException;
-
 	/**
 	 * Sets up the mailbox with the setup token.
 	 *
@@ -31,7 +19,7 @@ interface MailboxApi {
 	 * @return the owner token
 	 * @throws ApiException for 401 response.
 	 */
-	MailboxProperties setup(MailboxProperties properties)
+	String setup(MailboxProperties properties)
 			throws IOException, ApiException;
 
 	/**
@@ -43,14 +31,6 @@ interface MailboxApi {
 	boolean checkStatus(MailboxProperties properties)
 			throws IOException, ApiException;
 
-	/**
-	 * Unpairs Briar and the mailbox (owner only).
-	 * Resets mailbox state to that after first install
-	 * (e.g. removes all stored files as well).
-	 */
-	void wipeMailbox(MailboxProperties properties)
-			throws IOException, ApiException;
-
 	/**
 	 * Adds a new contact to the mailbox.
 	 *
@@ -77,78 +57,16 @@ interface MailboxApi {
 	Collection<ContactId> getContacts(MailboxProperties properties)
 			throws IOException, ApiException;
 
-	/**
-	 * Used by contacts to send files to the owner
-	 * and by the owner to send files to contacts.
-	 * <p>
-	 * The owner can add files to the contacts' inboxes
-	 * and the contacts can add files to their own outbox.
-	 */
-	void addFile(MailboxProperties properties, MailboxFolderId folderId,
-			File file) throws IOException, ApiException;
-
-	/**
-	 * Used by owner and contacts to list their files to retrieve.
-	 * <p>
-	 * Returns 200 OK with the list of files in JSON.
-	 *
-	 * @throws TolerableFailureException if response code is 404 (folder does
-	 * not exist or client is not authorised to download from it)
-	 */
-	List<MailboxFile> getFiles(MailboxProperties properties,
-			MailboxFolderId folderId)
-			throws IOException, ApiException, TolerableFailureException;
-
-	/**
-	 * Used by owner and contacts to retrieve a file.
-	 * <p>
-	 * Returns 200 OK if successful with the files' raw bytes
-	 * in the response body.
-	 *
-	 * @param file the empty file the response bytes will be written into.
-	 * @throws TolerableFailureException if response code is 404 (folder does
-	 * not exist, client is not authorised to download from folder, or file
-	 * does not exist)
-	 */
-	void getFile(MailboxProperties properties, MailboxFolderId folderId,
-			MailboxFileId fileId, File file)
-			throws IOException, ApiException, TolerableFailureException;
-
-	/**
-	 * Used by owner and contacts to delete files.
-	 * <p>
-	 * Returns 200 OK (no exception) if deletion was successful.
-	 *
-	 * @throws TolerableFailureException if response code is 404 (folder does
-	 * not exist, client is not authorised to download from folder, or file
-	 * does not exist)
-	 */
-	void deleteFile(MailboxProperties properties, MailboxFolderId folderId,
-			MailboxFileId fileId)
-			throws IOException, ApiException, TolerableFailureException;
-
-	/**
-	 * Lists all contact outboxes that have files available
-	 * for the owner to download.
-	 *
-	 * @return a list of folder names
-	 * to be used with {@link #getFiles(MailboxProperties, MailboxFolderId)}.
-	 * @throws IllegalArgumentException if used by non-owner.
-	 */
-	List<MailboxFolderId> getFolders(MailboxProperties properties)
-			throws IOException, ApiException;
-
 	@Immutable
 	@JsonSerialize
 	class MailboxContact {
 		public final int contactId;
-		public final MailboxAuthToken token;
+		public final String token, inboxId, outboxId;
-		public final MailboxFolderId inboxId, outboxId;
 
 		MailboxContact(ContactId contactId,
-				MailboxAuthToken token,
+				String token,
-				MailboxFolderId inboxId,
+				String inboxId,
-				MailboxFolderId outboxId) {
+				String outboxId) {
 			this.contactId = contactId.getInt();
 			this.token = token;
 			this.inboxId = inboxId;
@@ -156,32 +74,10 @@ interface MailboxApi {
 		}
 	}
 
-	@JsonSerialize
-	class MailboxFile implements Comparable<MailboxFile> {
-		public final MailboxFileId name;
-		public final long time;
-
-		public MailboxFile(MailboxFileId name, long time) {
-			this.name = name;
-			this.time = time;
-		}
-
-		@Override
-		public int compareTo(@Nonnull MailboxApi.MailboxFile mailboxFile) {
-			//noinspection UseCompareMethod
-			return time < mailboxFile.time ? -1 :
-					(time == mailboxFile.time ? 0 : 1);
-		}
-	}
-
 	@Immutable
 	class ApiException extends Exception {
 	}
 
-	@Immutable
-	class MailboxAlreadyPairedException extends ApiException {
-	}
-
 	/**
 	 * A failure that does not need to be retried,
 	 * e.g. when adding a contact that already exists.

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiCaller.java

@@ -1,34 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import static java.util.concurrent.TimeUnit.DAYS;
-import static java.util.concurrent.TimeUnit.MINUTES;
-
-@NotNullByDefault
-interface MailboxApiCaller {
-
-	/**
-	 * The minimum interval between retries in milliseconds.
-	 */
-	long MIN_RETRY_INTERVAL_MS = MINUTES.toMillis(1);
-
-	/**
-	 * The maximum interval between retries in milliseconds.
-	 */
-	long MAX_RETRY_INTERVAL_MS = DAYS.toMillis(1);
-
-	/**
-	 * Asynchronously calls the given API call on the {@link IoExecutor},
-	 * automatically retrying at increasing intervals until the API call
-	 * returns false or retries are cancelled.
-	 * <p>
-	 * This method is safe to call while holding a lock.
-	 *
-	 * @return A {@link Cancellable} that can be used to cancel any future
-	 * retries.
-	 */
-	Cancellable retryWithBackoff(ApiCall apiCall);
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiCallerImpl.java

@@ -1,98 +0,0 @@
-package org.briarproject.bramble.mailbox;
-
-import org.briarproject.bramble.api.Cancellable;
-import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.TaskScheduler;
-
-import java.util.concurrent.Executor;
-
-import javax.annotation.Nullable;
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.Immutable;
-import javax.inject.Inject;
-
-import static java.lang.Math.min;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-
-@Immutable
-@NotNullByDefault
-class MailboxApiCallerImpl implements MailboxApiCaller {
-
-	private final TaskScheduler taskScheduler;
-	private final Executor ioExecutor;
-
-	@Inject
-	MailboxApiCallerImpl(TaskScheduler taskScheduler,
-			@IoExecutor Executor ioExecutor) {
-		this.taskScheduler = taskScheduler;
-		this.ioExecutor = ioExecutor;
-	}
-
-	@Override
-	public Cancellable retryWithBackoff(ApiCall apiCall) {
-		Task task = new Task(apiCall);
-		task.start();
-		return task;
-	}
-
-	private class Task implements Cancellable {
-
-		private final ApiCall apiCall;
-		private final Object lock = new Object();
-
-		@GuardedBy("lock")
-		@Nullable
-		private Cancellable scheduledTask = null;
-
-		@GuardedBy("lock")
-		private boolean cancelled = false;
-
-		@GuardedBy("lock")
-		private long retryIntervalMs = MIN_RETRY_INTERVAL_MS;
-
-		private Task(ApiCall apiCall) {
-			this.apiCall = apiCall;
-		}
-
-		private void start() {
-			synchronized (lock) {
-				if (cancelled) throw new AssertionError();
-				ioExecutor.execute(this::callApi);
-			}
-		}
-
-		@IoExecutor
-		private void callApi() {
-			synchronized (lock) {
-				if (cancelled) return;
-			}
-			// The call returns true if we should retry
-			if (apiCall.callApi()) {
-				synchronized (lock) {
-					if (cancelled) return;
-					scheduledTask = taskScheduler.schedule(this::callApi,
-							ioExecutor, retryIntervalMs, MILLISECONDS);
-					// Increase the retry interval each time we retry
-					retryIntervalMs =
-							min(MAX_RETRY_INTERVAL_MS, retryIntervalMs * 2);
-				}
-			} else {
-				synchronized (lock) {
-					scheduledTask = null;
-				}
-			}
-		}
-
-		@Override
-		public void cancel() {
-			Cancellable scheduledTask;
-			synchronized (lock) {
-				cancelled = true;
-				scheduledTask = this.scheduledTask;
-				this.scheduledTask = null;
-			}
-			if (scheduledTask != null) scheduledTask.cancel();
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/mailbox/MailboxApiImpl.java

@@ -3,22 +3,12 @@ package org.briarproject.bramble.mailbox;
 import com.fasterxml.jackson.core.JacksonException;
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.json.JsonMapper;
-import com.fasterxml.jackson.databind.node.ArrayNode;
-import com.fasterxml.jackson.databind.node.ObjectNode;
 
 import org.briarproject.bramble.api.WeakSingletonProvider;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.mailbox.InvalidMailboxIdException;
-import org.briarproject.bramble.api.mailbox.MailboxAuthToken;
-import org.briarproject.bramble.api.mailbox.MailboxFileId;
-import org.briarproject.bramble.api.mailbox.MailboxFolderId;
-import org.briarproject.bramble.api.mailbox.MailboxId;
 import org.briarproject.bramble.api.mailbox.MailboxProperties;
-import org.briarproject.bramble.api.mailbox.MailboxVersion;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
-import java.io.File;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -34,60 +24,37 @@ import okhttp3.Response;
 import okhttp3.ResponseBody;
 
 import static com.fasterxml.jackson.databind.MapperFeature.BLOCK_UNSAFE_POLYMORPHIC_BASE_TYPES;
-import static java.util.Collections.sort;
 import static java.util.Objects.requireNonNull;
 import static okhttp3.internal.Util.EMPTY_REQUEST;
-import static org.briarproject.bramble.util.IoUtils.copyAndClose;
+import static org.briarproject.bramble.util.StringUtils.fromHexString;
 
 @NotNullByDefault
 class MailboxApiImpl implements MailboxApi {
 
-	private static final MediaType JSON =
-			requireNonNull(MediaType.parse("application/json; charset=utf-8"));
-	private static final MediaType FILE =
-			requireNonNull(MediaType.parse("application/octet-stream"));
-
 	private final WeakSingletonProvider<OkHttpClient> httpClientProvider;
 	private final JsonMapper mapper = JsonMapper.builder()
 			.enable(BLOCK_UNSAFE_POLYMORPHIC_BASE_TYPES)
 			.build();
-	private final UrlConverter urlConverter;
+	private static final MediaType JSON =
+			requireNonNull(MediaType.parse("application/json; charset=utf-8"));
 
 	@Inject
-	MailboxApiImpl(WeakSingletonProvider<OkHttpClient> httpClientProvider,
+	MailboxApiImpl(WeakSingletonProvider<OkHttpClient> httpClientProvider) {
-			UrlConverter urlConverter) {
 		this.httpClientProvider = httpClientProvider;
-		this.urlConverter = urlConverter;
 	}
 
 	@Override
-	public List<MailboxVersion> getServerSupports(MailboxProperties properties)
+	public String setup(MailboxProperties properties)
-			throws IOException, ApiException {
-		if (!properties.isOwner()) throw new IllegalArgumentException();
-		Response response = sendGetRequest(properties, "/versions");
-		if (response.code() != 200) throw new ApiException();
-
-		ResponseBody body = response.body();
-		if (body == null) throw new ApiException();
-		try {
-			JsonNode node = mapper.readTree(body.string());
-			return parseServerSupports(node);
-		} catch (JacksonException e) {
-			throw new ApiException();
-		}
-	}
-
-	@Override
-	public MailboxProperties setup(MailboxProperties properties)
 			throws IOException, ApiException {
 		if (!properties.isOwner()) throw new IllegalArgumentException();
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(getBaseUrl(properties) + "/setup")
+				.url(properties.getOnionAddress() + "/setup")
 				.put(EMPTY_REQUEST)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
 		Response response = client.newCall(request).execute();
-		if (response.code() == 401) throw new MailboxAlreadyPairedException();
+		// TODO consider throwing a special exception for the 401 case
+		if (response.code() == 401) throw new ApiException();
 		if (!response.isSuccessful()) throw new ApiException();
 		ResponseBody body = response.body();
 		if (body == null) throw new ApiException();
@@ -97,69 +64,49 @@ class MailboxApiImpl implements MailboxApi {
 			if (tokenNode == null) {
 				throw new ApiException();
 			}
-			return new MailboxProperties(properties.getOnion(),
+			String ownerToken = tokenNode.textValue();
-					MailboxAuthToken.fromString(tokenNode.textValue()),
+			if (ownerToken == null || !isValidToken(ownerToken)) {
-					parseServerSupports(node));
+				throw new ApiException();
-		} catch (JacksonException | InvalidMailboxIdException e) {
+			}
+			return ownerToken;
+		} catch (JacksonException e) {
 			throw new ApiException();
 		}
 	}
 
-	private List<MailboxVersion> parseServerSupports(JsonNode node)
+	private boolean isValidToken(String token) {
-			throws ApiException {
+		if (token.length() != 64) return false;
-		List<MailboxVersion> serverSupports = new ArrayList<>();
+		try {
-		ArrayNode serverSupportsNode = getArray(node, "serverSupports");
+			// try to convert to bytes
-		for (JsonNode versionNode : serverSupportsNode) {
+			fromHexString(token);
-			if (!versionNode.isObject()) throw new ApiException();
+			return true;
-			ObjectNode objectNode = (ObjectNode) versionNode;
+		} catch (IllegalArgumentException e) {
-			JsonNode majorNode = objectNode.get("major");
+			return false;
-			JsonNode minorNode = objectNode.get("minor");
-			if (majorNode == null || !majorNode.isNumber()) {
-				throw new ApiException();
-			}
-			if (minorNode == null || !minorNode.isNumber()) {
-				throw new ApiException();
-			}
-			int major = majorNode.asInt();
-			int minor = minorNode.asInt();
-			if (major < 0 || minor < 0) throw new ApiException();
-			serverSupports.add(new MailboxVersion(major, minor));
 		}
-		// Sort the list of versions for easier comparison
-		sort(serverSupports);
-		return serverSupports;
 	}
 
 	@Override
 	public boolean checkStatus(MailboxProperties properties)
 			throws IOException, ApiException {
+		if (!properties.isOwner()) throw new IllegalArgumentException();
 		Response response = sendGetRequest(properties, "/status");
 		if (response.code() == 401) throw new ApiException();
 		return response.isSuccessful();
 	}
 
-	@Override
-	public void wipeMailbox(MailboxProperties properties)
-			throws IOException, ApiException {
-		if (!properties.isOwner()) throw new IllegalArgumentException();
-		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(getBaseUrl(properties) + "/")
-				.delete()
-				.build();
-		OkHttpClient client = httpClientProvider.get();
-		Response response = client.newCall(request).execute();
-		if (response.code() != 204) throw new ApiException();
-	}
-
-	/* Contact Management API (owner only) */
-
 	@Override
 	public void addContact(MailboxProperties properties, MailboxContact contact)
-			throws IOException, ApiException, TolerableFailureException {
+			throws IOException, ApiException,
+			TolerableFailureException {
 		if (!properties.isOwner()) throw new IllegalArgumentException();
 		byte[] bodyBytes = mapper.writeValueAsBytes(contact);
 		RequestBody body = RequestBody.create(JSON, bodyBytes);
-		Response response = sendPostRequest(properties, "/contacts", body);
+		Request request = getRequestBuilder(properties.getAuthToken())
+				.url(properties.getOnionAddress() + "/contacts")
+				.post(body)
+				.build();
+		OkHttpClient client = httpClientProvider.get();
+		Response response = client.newCall(request).execute();
 		if (response.code() == 409) throw new TolerableFailureException();
 		if (!response.isSuccessful()) throw new ApiException();
 	}
@@ -168,7 +115,7 @@ class MailboxApiImpl implements MailboxApi {
 	public void deleteContact(MailboxProperties properties, ContactId contactId)
 			throws IOException, ApiException, TolerableFailureException {
 		if (!properties.isOwner()) throw new IllegalArgumentException();
-		String url = getBaseUrl(properties) + "/contacts/" +
+		String url = properties.getOnionAddress() + "/contacts/" +
 				contactId.getInt();
 		Request request = getRequestBuilder(properties.getAuthToken())
 				.delete()
@@ -191,7 +138,10 @@ class MailboxApiImpl implements MailboxApi {
 		if (body == null) throw new ApiException();
 		try {
 			JsonNode node = mapper.readTree(body.string());
-			ArrayNode contactsNode = getArray(node, "contacts");
+			JsonNode contactsNode = node.get("contacts");
+			if (contactsNode == null || !contactsNode.isArray()) {
+				throw new ApiException();
+			}
 			List<ContactId> list = new ArrayList<>();
 			for (JsonNode contactNode : contactsNode) {
 				if (!contactNode.isNumber()) throw new ApiException();
@@ -205,151 +155,18 @@ class MailboxApiImpl implements MailboxApi {
 		}
 	}
 
-	/* File Management (owner and contacts) */
-
-	@Override
-	public void addFile(MailboxProperties properties, MailboxFolderId folderId,
-			File file) throws IOException, ApiException {
-		String path = "/files/" + folderId;
-		RequestBody body = RequestBody.create(FILE, file);
-		Response response = sendPostRequest(properties, path, body);
-		if (response.code() != 200) throw new ApiException();
-	}
-
-	@Override
-	public List<MailboxFile> getFiles(MailboxProperties properties,
-			MailboxFolderId folderId)
-			throws IOException, ApiException, TolerableFailureException {
-		String path = "/files/" + folderId;
-		Response response = sendGetRequest(properties, path);
-		if (response.code() == 404) throw new TolerableFailureException();
-		if (response.code() != 200) throw new ApiException();
-
-		ResponseBody body = response.body();
-		if (body == null) throw new ApiException();
-		try {
-			JsonNode node = mapper.readTree(body.string());
-			ArrayNode filesNode = getArray(node, "files");
-			List<MailboxFile> list = new ArrayList<>();
-			for (JsonNode fileNode : filesNode) {
-				if (!fileNode.isObject()) throw new ApiException();
-				ObjectNode objectNode = (ObjectNode) fileNode;
-				JsonNode nameNode = objectNode.get("name");
-				JsonNode timeNode = objectNode.get("time");
-				if (nameNode == null || !nameNode.isTextual()) {
-					throw new ApiException();
-				}
-				if (timeNode == null || !timeNode.isNumber()) {
-					throw new ApiException();
-				}
-				String name = nameNode.asText();
-				long time = timeNode.asLong();
-				if (time < 1) throw new ApiException();
-				list.add(new MailboxFile(MailboxFileId.fromString(name), time));
-			}
-			sort(list);
-			return list;
-		} catch (JacksonException | InvalidMailboxIdException e) {
-			throw new ApiException();
-		}
-	}
-
-	@Override
-	public void getFile(MailboxProperties properties, MailboxFolderId folderId,
-			MailboxFileId fileId, File file)
-			throws IOException, ApiException, TolerableFailureException {
-		String path = "/files/" + folderId + "/" + fileId;
-		Response response = sendGetRequest(properties, path);
-		if (response.code() == 404) throw new TolerableFailureException();
-		if (response.code() != 200) throw new ApiException();
-
-		ResponseBody body = response.body();
-		if (body == null) throw new ApiException();
-		FileOutputStream outputStream = new FileOutputStream(file);
-		copyAndClose(body.byteStream(), outputStream);
-	}
-
-	@Override
-	public void deleteFile(MailboxProperties properties,
-			MailboxFolderId folderId, MailboxFileId fileId)
-			throws IOException, ApiException, TolerableFailureException {
-		String path = "/files/" + folderId + "/" + fileId;
-		Request request = getRequestBuilder(properties.getAuthToken())
-				.delete()
-				.url(getBaseUrl(properties) + path)
-				.build();
-		OkHttpClient client = httpClientProvider.get();
-		Response response = client.newCall(request).execute();
-		if (response.code() == 404) throw new TolerableFailureException();
-		if (response.code() != 200) throw new ApiException();
-	}
-
-	@Override
-	public List<MailboxFolderId> getFolders(MailboxProperties properties)
-			throws IOException, ApiException {
-		if (!properties.isOwner()) throw new IllegalArgumentException();
-		Response response = sendGetRequest(properties, "/folders");
-		if (response.code() != 200) throw new ApiException();
-
-		ResponseBody body = response.body();
-		if (body == null) throw new ApiException();
-		try {
-			JsonNode node = mapper.readTree(body.string());
-			ArrayNode filesNode = getArray(node, "folders");
-			List<MailboxFolderId> list = new ArrayList<>();
-			for (JsonNode fileNode : filesNode) {
-				if (!fileNode.isObject()) throw new ApiException();
-				ObjectNode objectNode = (ObjectNode) fileNode;
-				JsonNode idNode = objectNode.get("id");
-				if (idNode == null || !idNode.isTextual()) {
-					throw new ApiException();
-				}
-				String id = idNode.asText();
-				list.add(MailboxFolderId.fromString(id));
-			}
-			return list;
-		} catch (JacksonException | InvalidMailboxIdException e) {
-			throw new ApiException();
-		}
-	}
-
-	/* Helper Functions */
-
 	private Response sendGetRequest(MailboxProperties properties, String path)
 			throws IOException {
 		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(getBaseUrl(properties) + path)
+				.url(properties.getOnionAddress() + path)
 				.build();
 		OkHttpClient client = httpClientProvider.get();
 		return client.newCall(request).execute();
 	}
 
-	private Response sendPostRequest(MailboxProperties properties, String path,
+	private Request.Builder getRequestBuilder(String token) {
-			RequestBody body) throws IOException {
-		Request request = getRequestBuilder(properties.getAuthToken())
-				.url(getBaseUrl(properties) + path)
-				.post(body)
-				.build();
-		OkHttpClient client = httpClientProvider.get();
-		return client.newCall(request).execute();
-	}
-
-	private Request.Builder getRequestBuilder(MailboxId token) {
 		return new Request.Builder()
 				.addHeader("Authorization", "Bearer " + token);
 	}
 
-	/* JSON helpers */
-
-	private ArrayNode getArray(JsonNode node, String name) throws ApiException {
-		JsonNode arrayNode = node.get(name);
-		if (arrayNode == null || !arrayNode.isArray()) {
-			throw new ApiException();
-		}
-		return (ArrayNode) arrayNode;
-	}
-
-	private String getBaseUrl(MailboxProperties properties) {
-		return urlConverter.convertOnionToBaseUrl(properties.getOnion());
-	}
 }