DO NOT MERGE: Log contact name and alias.

Use the logger. Log the contact name, alias and message status.

bramble-android/build.gradle

@@ -11,10 +11,10 @@ android {
 	}
 
 	defaultConfig {
-		minSdkVersion 16
+		minSdkVersion 21
-		targetSdkVersion 31
+		targetSdkVersion 33
-		versionCode 10501
+		versionCode 10504
-		versionName "1.5.1"
+		versionName "1.5.4"
 		consumerProguardFiles 'proguard-rules.txt'
 
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -40,7 +40,7 @@ configurations {
 }
 
 dependencies {
-	api 'org.briarproject:dont-kill-me-lib:0.2.6'
+	api 'org.briarproject:dont-kill-me-lib:0.2.7'
 
 	// In theory this dependency shouldn't be needed, but without it Android Studio's linter will
 	// complain about unresolved symbols for bramble-api test classes in bramble-android tests,

bramble-android/src/main/java/org/briarproject/android/dontkillmelib/wakelock/AndroidWakeLockModule.java

@@ -1,17 +0,0 @@
-package org.briarproject.android.dontkillmelib.wakelock;
-
-import javax.inject.Singleton;
-
-import dagger.Module;
-import dagger.Provides;
-
-@Module
-public class AndroidWakeLockModule {
-
-	@Provides
-	@Singleton
-	AndroidWakeLockManager provideWakeLockManager(
-			AndroidWakeLockManagerImpl wakeLockManager) {
-		return wakeLockManager;
-	}
-}

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

@@ -1,16 +1,16 @@
 package org.briarproject.bramble;
 
-import org.briarproject.android.dontkillmelib.wakelock.AndroidWakeLockModule;
 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;
 import org.briarproject.bramble.socks.SocksModule;
 import org.briarproject.bramble.system.AndroidSystemModule;
 import org.briarproject.bramble.system.AndroidTaskSchedulerModule;
+import org.briarproject.bramble.system.AndroidWakeLockModule;
 import org.briarproject.bramble.system.AndroidWakefulIoExecutorModule;
 import org.briarproject.bramble.system.DefaultThreadFactoryModule;
-import org.briarproject.onionwrapper.CircumventionModule;
 
 import dagger.Module;
 

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

@@ -20,7 +20,6 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.GuardedBy;
 import javax.inject.Inject;
 
-import static android.os.Build.VERSION.SDK_INT;
 import static java.util.Arrays.asList;
 import static java.util.logging.Level.INFO;
 import static org.briarproject.bramble.util.IoUtils.deleteFileOrDir;
@@ -105,15 +104,11 @@ class AndroidAccountManager extends AccountManagerImpl
 		}
 		files.add(appContext.getFilesDir());
 		addIfNotNull(files, appContext.getExternalCacheDir());
-		if (SDK_INT >= 19) {
+		for (File file : appContext.getExternalCacheDirs()) {
-			for (File file : appContext.getExternalCacheDirs()) {
+			addIfNotNull(files, file);
-				addIfNotNull(files, file);
-			}
 		}
-		if (SDK_INT >= 21) {
+		for (File file : appContext.getExternalMediaDirs()) {
-			for (File file : appContext.getExternalMediaDirs()) {
+			addIfNotNull(files, file);
-				addIfNotNull(files, file);
-			}
 		}
 		// Clear the cache directory but don't delete it
 		File cacheDir = appContext.getCacheDir();

bramble-android/src/main/java/org/briarproject/bramble/battery/AndroidBatteryManager.java

@@ -5,6 +5,7 @@ import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
+import android.os.PowerManager;
 
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.battery.event.BatteryEvent;
@@ -16,10 +17,17 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import androidx.annotation.RequiresApi;
+
 import static android.content.Intent.ACTION_BATTERY_CHANGED;
 import static android.content.Intent.ACTION_POWER_CONNECTED;
 import static android.content.Intent.ACTION_POWER_DISCONNECTED;
 import static android.os.BatteryManager.EXTRA_PLUGGED;
+import static android.os.Build.VERSION.SDK_INT;
+import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
+import static android.os.PowerManager.ACTION_DEVICE_LIGHT_IDLE_MODE_CHANGED;
+import static android.os.PowerManager.ACTION_LOW_POWER_STANDBY_ENABLED_CHANGED;
+import static android.os.PowerManager.ACTION_POWER_SAVE_MODE_CHANGED;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
 
@@ -57,6 +65,12 @@ class AndroidBatteryManager implements BatteryManager, Service {
 		IntentFilter filter = new IntentFilter();
 		filter.addAction(ACTION_POWER_CONNECTED);
 		filter.addAction(ACTION_POWER_DISCONNECTED);
+		filter.addAction(ACTION_POWER_SAVE_MODE_CHANGED);
+		if (SDK_INT >= 23) filter.addAction(ACTION_DEVICE_IDLE_MODE_CHANGED);
+		if (SDK_INT >= 33) {
+			filter.addAction(ACTION_LOW_POWER_STANDBY_ENABLED_CHANGED);
+			filter.addAction(ACTION_DEVICE_LIGHT_IDLE_MODE_CHANGED);
+		}
 		appContext.registerReceiver(batteryReceiver, filter);
 	}
 
@@ -76,6 +90,33 @@ class AndroidBatteryManager implements BatteryManager, Service {
 				eventBus.broadcast(new BatteryEvent(true));
 			else if (ACTION_POWER_DISCONNECTED.equals(action))
 				eventBus.broadcast(new BatteryEvent(false));
+			else if (SDK_INT >= 23 &&
+					ACTION_DEVICE_IDLE_MODE_CHANGED.equals(action) &&
+					LOG.isLoggable(INFO)) {
+				LOG.info("Device idle mode changed to: " +
+						getPowerManager(ctx).isDeviceIdleMode());
+			} else if (SDK_INT >= 23 &&
+					ACTION_POWER_SAVE_MODE_CHANGED.equals(action) &&
+					LOG.isLoggable(INFO)) {
+				LOG.info("Power save mode changed to: " +
+						getPowerManager(ctx).isPowerSaveMode());
+			} else if (SDK_INT >= 33 && LOG.isLoggable(INFO) &&
+					ACTION_LOW_POWER_STANDBY_ENABLED_CHANGED.equals(action)) {
+				PowerManager powerManager =
+						ctx.getSystemService(PowerManager.class);
+				LOG.info("Low power standby now is: " +
+						powerManager.isLowPowerStandbyEnabled());
+			} else if (SDK_INT >= 33 && LOG.isLoggable(INFO) &&
+					ACTION_DEVICE_LIGHT_IDLE_MODE_CHANGED.equals(action)) {
+				PowerManager powerManager = getPowerManager(ctx);
+				LOG.info("Light idle mode now is: " +
+						powerManager.isDeviceLightIdleMode());
+			}
 		}
 	}
+
+	@RequiresApi(api = 23)
+	private PowerManager getPowerManager(Context ctx) {
+		return ctx.getSystemService(PowerManager.class);
+	}
 }

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.plugin.bluetooth;
 
+import android.annotation.SuppressLint;
 import android.app.Application;
 import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
@@ -49,7 +50,6 @@ import static android.bluetooth.BluetoothAdapter.STATE_ON;
 import static android.bluetooth.BluetoothDevice.ACTION_FOUND;
 import static android.bluetooth.BluetoothDevice.DEVICE_TYPE_LE;
 import static android.bluetooth.BluetoothDevice.EXTRA_DEVICE;
-import static android.os.Build.VERSION.SDK_INT;
 import static java.util.Collections.shuffle;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.INFO;
@@ -60,6 +60,7 @@ import static org.briarproject.bramble.util.PrivacyUtils.scrubMacAddress;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
+@SuppressLint("MissingPermission")
 class AndroidBluetoothPlugin extends
 		AbstractBluetoothPlugin<BluetoothSocket, BluetoothServerSocket> {
 
@@ -253,7 +254,7 @@ class AndroidBluetoothPlugin extends
 					} else if (ACTION_FOUND.equals(action)) {
 						BluetoothDevice d = i.getParcelableExtra(EXTRA_DEVICE);
 						// Ignore Bluetooth LE devices
-						if (SDK_INT < 18 || d.getType() != DEVICE_TYPE_LE) {
+						if (d.getType() != DEVICE_TYPE_LE) {
 							String address = d.getAddress();
 							if (LOG.isLoggable(INFO))
 								LOG.info("Discovered " +

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.plugin.tcp;
 
-import android.annotation.TargetApi;
 import android.app.Application;
 import android.net.ConnectivityManager;
 import android.net.LinkAddress;
@@ -37,7 +36,6 @@ import javax.net.SocketFactory;
 import static android.content.Context.CONNECTIVITY_SERVICE;
 import static android.content.Context.WIFI_SERVICE;
 import static android.net.NetworkCapabilities.TRANSPORT_WIFI;
-import static android.os.Build.VERSION.SDK_INT;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.list;
 import static java.util.Collections.singletonList;
@@ -118,7 +116,7 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 		// If there's no wifi IPv4 address, we might be a client on an
 		// IPv6-only wifi network. We can only detect this on API 21+
 		if (wifi == null) {
-			return SDK_INT >= 21 ? getWifiClientIpv6Address() : null;
+			return getWifiClientIpv6Address();
 		}
 		// Use the wifi IPv4 address to determine which interface's IPv6
 		// address we should return (if the interface has a suitable address)
@@ -172,7 +170,6 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 	 * Returns a link-local IPv6 address for the wifi client interface, or null
 	 * if there's no such interface or it doesn't have a suitable address.
 	 */
-	@TargetApi(21)
 	@Nullable
 	private InetAddress getWifiClientIpv6Address() {
 		// https://issuetracker.google.com/issues/175055271
@@ -234,7 +231,6 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 	// On API 21 and later, a socket that is not created with the wifi
 	// 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
 		try {
 			for (Network net : connectivityManager.getAllNetworks()) {
@@ -302,7 +298,7 @@ class AndroidLanTcpPlugin extends LanTcpPlugin {
 		Pair<InetAddress, Boolean> wifi = getWifiIpv4Address();
 		// If there's no wifi IPv4 address, we might be a client on an
 		// IPv6-only wifi network. We can only detect this on API 21+
-		if (wifi == null && SDK_INT >= 21) {
+		if (wifi == null) {
 			InetAddress ipv6 = getWifiClientIpv6Address();
 			if (ipv6 != null) return new Pair<>(ipv6, false);
 		}

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

@@ -16,11 +16,11 @@ 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.system.Clock;
-import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.WakefulIoExecutor;
 import org.briarproject.nullsafety.NotNullByDefault;
 import org.briarproject.onionwrapper.AndroidTorWrapper;
 import org.briarproject.onionwrapper.CircumventionProvider;
+import org.briarproject.onionwrapper.LocationUtils;
 import org.briarproject.onionwrapper.TorWrapper;
 
 import java.io.File;

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

@@ -1,72 +0,0 @@
-package org.briarproject.bramble.system;
-
-import android.annotation.SuppressLint;
-import android.app.Application;
-import android.content.Context;
-import android.telephony.TelephonyManager;
-import android.text.TextUtils;
-
-import org.briarproject.bramble.api.system.LocationUtils;
-import org.briarproject.nullsafety.NotNullByDefault;
-
-import java.util.Locale;
-import java.util.logging.Logger;
-
-import javax.inject.Inject;
-
-import static android.content.Context.TELEPHONY_SERVICE;
-
-@NotNullByDefault
-class AndroidLocationUtils implements LocationUtils {
-
-	private static final Logger LOG =
-			Logger.getLogger(AndroidLocationUtils.class.getName());
-
-	private final Context appContext;
-
-	@Inject
-	AndroidLocationUtils(Application app) {
-		appContext = app.getApplicationContext();
-	}
-
-	/**
-	 * This guesses the current country from the first of these sources that
-	 * succeeds (also in order of likelihood of being correct):
-	 *
-	 * <ul>
-	 * <li>Phone network. This works even when no SIM card is inserted, or a
-	 *     foreign SIM card is inserted.</li>
-	 * <li>SIM card. This is only an heuristic and assumes the user is not
-	 *     roaming.</li>
-	 * <li>User locale. This is an even worse heuristic.</li>
-	 * </ul>
-	 *
-	 * Note: this is very similar to <a href="https://android.googlesource.com/platform/frameworks/base/+/cd92588%5E/location/java/android/location/CountryDetector.java">
-	 * this API</a> except it seems that Google doesn't want us to use it for
-	 * some reason - both that class and {@code Context.COUNTRY_CODE} are
-	 * annotated {@code @hide}.
-	 */
-	@Override
-	@SuppressLint("DefaultLocale")
-	public String getCurrentCountry() {
-		String countryCode = getCountryFromPhoneNetwork();
-		if (!TextUtils.isEmpty(countryCode)) return countryCode.toUpperCase();
-		LOG.info("Falling back to SIM card country");
-		countryCode = getCountryFromSimCard();
-		if (!TextUtils.isEmpty(countryCode)) return countryCode.toUpperCase();
-		LOG.info("Falling back to user-defined locale");
-		return Locale.getDefault().getCountry();
-	}
-
-	private String getCountryFromPhoneNetwork() {
-		Object o = appContext.getSystemService(TELEPHONY_SERVICE);
-		TelephonyManager tm = (TelephonyManager) o;
-		return tm == null ? "" : tm.getNetworkCountryIso();
-	}
-
-	private String getCountryFromSimCard() {
-		Object o = appContext.getSystemService(TELEPHONY_SERVICE);
-		TelephonyManager tm = (TelephonyManager) o;
-		return tm == null ? "" : tm.getSimCountryIso();
-	}
-}

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

@@ -31,8 +31,6 @@ import static android.provider.Settings.Secure.ANDROID_ID;
 @NotNullByDefault
 class AndroidSecureRandomProvider extends UnixSecureRandomProvider {
 
-	private static final int SEED_LENGTH = 32;
-
 	private final Context appContext;
 
 	@Inject
@@ -72,27 +70,6 @@ class AndroidSecureRandomProvider extends UnixSecureRandomProvider {
 		// Silence strict mode
 		StrictMode.ThreadPolicy tp = StrictMode.allowThreadDiskWrites();
 		super.writeSeed();
-		if (SDK_INT <= 18) applyOpenSslFix();
 		StrictMode.setThreadPolicy(tp);
 	}
-
-	// Based on https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html
-	private void applyOpenSslFix() {
-		byte[] seed = new UnixSecureRandomSpi().engineGenerateSeed(
-				SEED_LENGTH);
-		try {
-			// Seed the OpenSSL PRNG
-			Class.forName("org.apache.harmony.xnet.provider.jsse.NativeCrypto")
-					.getMethod("RAND_seed", byte[].class)
-					.invoke(null, (Object) seed);
-			// Mix the output of the Linux PRNG into the OpenSSL PRNG
-			int bytesRead = (Integer) Class.forName(
-							"org.apache.harmony.xnet.provider.jsse.NativeCrypto")
-					.getMethod("RAND_load_file", String.class, long.class)
-					.invoke(null, "/dev/urandom", 1024);
-			if (bytesRead != 1024) throw new IOException();
-		} catch (Exception e) {
-			throw new SecurityException(e);
-		}
-	}
 }

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

@@ -1,11 +1,14 @@
 package org.briarproject.bramble.system;
 
+import android.app.Application;
+
 import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.system.AndroidExecutor;
-import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
 import org.briarproject.bramble.api.system.SecureRandomProvider;
+import org.briarproject.onionwrapper.AndroidLocationUtilsFactory;
+import org.briarproject.onionwrapper.LocationUtils;
 
 import java.util.concurrent.Executor;
 import java.util.concurrent.RejectedExecutionHandler;
@@ -45,8 +48,9 @@ public class AndroidSystemModule {
 	}
 
 	@Provides
-	LocationUtils provideLocationUtils(AndroidLocationUtils locationUtils) {
+	@Singleton
-		return locationUtils;
+	LocationUtils provideLocationUtils(Application app) {
+		return AndroidLocationUtilsFactory.createAndroidLocationUtils(app);
 	}
 
 	@Provides

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

@@ -0,0 +1,25 @@
+package org.briarproject.bramble.system;
+
+import android.app.Application;
+
+import org.briarproject.android.dontkillmelib.wakelock.AndroidWakeLockManager;
+import org.briarproject.android.dontkillmelib.wakelock.AndroidWakeLockManagerFactory;
+
+import java.util.concurrent.ScheduledExecutorService;
+
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class AndroidWakeLockModule {
+
+	@Provides
+	@Singleton
+	AndroidWakeLockManager provideWakeLockManager(Application app,
+			ScheduledExecutorService scheduledExecutorService) {
+		return AndroidWakeLockManagerFactory.createAndroidWakeLockManager(app,
+				scheduledExecutorService);
+	}
+}

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

@@ -11,14 +11,10 @@ import org.briarproject.bramble.api.Pair;
 import org.briarproject.nullsafety.NotNullByDefault;
 
 import java.io.File;
-import java.io.IOException;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.List;
-import java.util.Scanner;
 
 import javax.annotation.Nullable;
 
@@ -29,7 +25,6 @@ import static android.content.pm.PackageManager.PERMISSION_GRANTED;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.os.Process.myPid;
 import static android.os.Process.myUid;
-import static java.lang.Runtime.getRuntime;
 import static java.util.Arrays.asList;
 import static org.briarproject.nullsafety.NullSafety.requireNonNull;
 
@@ -43,14 +38,7 @@ public class AndroidUtils {
 	private static final String STORED_LOGCAT = "dev-logcat";
 
 	public static Collection<String> getSupportedArchitectures() {
-		List<String> abis = new ArrayList<>();
+		return asList(Build.SUPPORTED_ABIS);
-		if (SDK_INT >= 21) {
-			abis.addAll(asList(Build.SUPPORTED_ABIS));
-		} else {
-			abis.add(Build.CPU_ABI);
-			if (Build.CPU_ABI2 != null) abis.add(Build.CPU_ABI2);
-		}
-		return abis;
 	}
 
 	public static boolean hasBtConnectPermission(Context ctx) {
@@ -75,10 +63,12 @@ public class AndroidUtils {
 			return new Pair<>(address, "adapter");
 		}
 		// Return the address from settings if it's valid and not fake
-		address = Settings.Secure.getString(ctx.getContentResolver(),
+		if (SDK_INT < 33) {
-				"bluetooth_address");
+			address = Settings.Secure.getString(ctx.getContentResolver(),
-		if (isValidBluetoothAddress(address)) {
+					"bluetooth_address");
-			return new Pair<>(address, "settings");
+			if (isValidBluetoothAddress(address)) {
+				return new Pair<>(address, "settings");
+			}
 		}
 		// Try to get the address via reflection
 		address = getBluetoothAddressByReflection(adapter);
@@ -136,19 +126,6 @@ public class AndroidUtils {
 		return new String[] {"image/jpeg", "image/png", "image/gif"};
 	}
 
-	@Nullable
-	public static String getSystemProperty(String propName) {
-		try {
-			Process p = getRuntime().exec("getprop " + propName);
-			Scanner s = new Scanner(p.getInputStream());
-			String line = s.nextLine();
-			s.close();
-			return line;
-		} catch (SecurityException | IOException e) {
-			return null;
-		}
-	}
-
 	public static boolean isUiThread() {
 		return Looper.myLooper() == Looper.getMainLooper();
 	}

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

@@ -87,6 +87,10 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 		File potatoFile = new File(potatoDir, "file");
 		File filesDir = new File(testDir, "filesDir");
 		File externalCacheDir = new File(testDir, "externalCacheDir");
+		File externalCacheDir1 = new File(testDir, "externalCacheDir1");
+		File externalCacheDir2 = new File(testDir, "externalCacheDir2");
+		File externalMediaDir1 = new File(testDir, "externalMediaDir1");
+		File externalMediaDir2 = new File(testDir, "externalMediaDir2");
 
 		context.checking(new Expectations() {{
 			oneOf(prefs).edit();
@@ -109,6 +113,12 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 			will(returnValue(cacheDir));
 			oneOf(app).getExternalCacheDir();
 			will(returnValue(externalCacheDir));
+			oneOf(app).getExternalCacheDirs();
+			will(returnValue(
+					new File[] {externalCacheDir1, externalCacheDir2}));
+			oneOf(app).getExternalMediaDirs();
+			will(returnValue(
+					new File[] {externalMediaDir1, externalMediaDir2}));
 		}});
 
 		assertTrue(dbDir.mkdirs());
@@ -125,6 +135,10 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 		assertTrue(potatoFile.createNewFile());
 		assertTrue(filesDir.mkdirs());
 		assertTrue(externalCacheDir.mkdirs());
+		assertTrue(externalCacheDir1.mkdirs());
+		assertTrue(externalCacheDir2.mkdirs());
+		assertTrue(externalMediaDir1.mkdirs());
+		assertTrue(externalMediaDir2.mkdirs());
 
 		accountManager.deleteAccount();
 
@@ -142,6 +156,10 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 		assertFalse(potatoFile.exists());
 		assertFalse(filesDir.exists());
 		assertFalse(externalCacheDir.exists());
+		assertFalse(externalCacheDir1.exists());
+		assertFalse(externalCacheDir2.exists());
+		assertFalse(externalMediaDir1.exists());
+		assertFalse(externalMediaDir2.exists());
 	}
 
 	@After

bramble-android/witness.gradle

@@ -4,10 +4,10 @@ dependencyVerification {
         'cglib:cglib:3.2.8:cglib-3.2.8.jar:3f64de999ecc5595dc84ca8ff0879d8a34c8623f9ef3c517a53ed59023fcb9db',
         '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-compiler:2.43.2:dagger-compiler-2.43.2.jar:298c020ee6ed2f4cc651ebbfdb7f8de329b07c44b618d65be117846a850e2a03',
+        'com.google.dagger:dagger-compiler:2.45:dagger-compiler-2.45.jar:5617dfb994537dba5b41f3744a6dd13ec3cd99789c065e0d5c6fa9f21cf7ca25',
-        'com.google.dagger:dagger-producers:2.43.2:dagger-producers-2.43.2.jar:e7f5d9ffc85d48a49c8e22e02833d418f7ccad5d7512f529964db5127ab915ff',
+        'com.google.dagger:dagger-producers:2.45:dagger-producers-2.45.jar:a05abb4c3ccf6bb0f056bdcb5ef973898ecf172952ab5948a824aeea6c86ecaa',
-        'com.google.dagger:dagger-spi:2.43.2:dagger-spi-2.43.2.jar:3bae8d9dadeaaa5927da6f094389a560c12c05fec3d2711d2fa79292c7a7d7ad',
+        'com.google.dagger:dagger-spi:2.45:dagger-spi-2.45.jar:7cd6f0b09d88e64a9c97bc80e544ab8ac8fdee9301754413585a74cf64222b27',
-        'com.google.dagger:dagger:2.43.2:dagger-2.43.2.jar:c89681f7cbbf8c527bf4ac2748515d617fdb54a1d425c08d914fdc28192b5fe4',
+        'com.google.dagger:dagger:2.45:dagger-2.45.jar:f011cae7d2c0fb7ea17c34e05bc10e768b1081a5892ad019cf1fdb0e125c49c1',
         'com.google.devtools.ksp:symbol-processing-api:1.7.0-1.0.6:symbol-processing-api-1.7.0-1.0.6.jar:adc29417be5ca9ff42118105fea4e36d9ef44987abfc41432309371a60198941',
         'com.google.errorprone:error_prone_annotations:2.7.1:error_prone_annotations-2.7.1.jar:cd5257c08a246cf8628817ae71cb822be192ef91f6881ca4a3fcff4f1de1cff3',
         'com.google.errorprone:javac-shaded:9-dev-r4023-3:javac-shaded-9-dev-r4023-3.jar:65bfccf60986c47fbc17c9ebab0be626afc41741e0a6ec7109e0768817a36f30',
@@ -17,6 +17,7 @@ dependencyVerification {
         'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava:listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:b372a037d4230aa57fbeffdef30fd6123f9c0c2db85d0aced00c91b974f33f99',
         'com.google.j2objc:j2objc-annotations:1.3:j2objc-annotations-1.3.jar:21af30c92267bd6122c0e0b4d20cccb6641a37eaf956c6540ec471d584e64a7b',
         'com.squareup:javapoet:1.13.0:javapoet-1.13.0.jar:4c7517e848a71b36d069d12bb3bf46a70fd4cda3105d822b0ed2e19c00b69291',
+        'com.squareup:kotlinpoet:1.11.0:kotlinpoet-1.11.0.jar:2887ada1ca03dd83baa2758640d87e840d1907564db0ef88d2289c868a980492',
         'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.13.2:junit-4.13.2.jar:8e495b634469d64fb8acfa3495a065cbacc8a0fff55ce1e31007be4c16dc57d3',
@@ -24,12 +25,12 @@ dependencyVerification {
         'net.jcip:jcip-annotations:1.0:jcip-annotations-1.0.jar:be5805392060c71474bf6c9a67a099471274d30b83eef84bfc4e0889a4f1dcc0',
         'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
         'org.apache-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
-        'org.briarproject:dont-kill-me-lib:0.2.6:dont-kill-me-lib-0.2.6.aar:8a4cc201143227c0865c2edfba035f71109bf02e1ab26444fa3e42d3c569960f',
+        'org.briarproject:dont-kill-me-lib:0.2.7:dont-kill-me-lib-0.2.7.aar:8a9540941fd927e1c127096a7a9b4aa61ce2f2965d2e24f849be92f9e57213c4',
         'org.briarproject:jtorctl:0.5:jtorctl-0.5.jar:43f8c7d390169772b9a2c82ab806c8414c136a2a8636c555e22754bb7260793b',
         'org.briarproject:null-safety:0.1:null-safety-0.1.jar:161760de5e838cb982bafa973df820675d4397098e9a91637a36a306d43ba011',
         'org.briarproject:obfs4proxy-android:0.0.14-tor2:obfs4proxy-android-0.0.14-tor2.jar:a0a93770d6760ce57d9dbd31cc7177687374e00c3361dac22ab75e3b6e0f289e',
-        'org.briarproject:onionwrapper-android:0.0.1:onionwrapper-android-0.0.1.aar:959115946586daa090f057645cf75992407a59025e221c3bf88d2aa930ef3919',
+        'org.briarproject:onionwrapper-android:0.0.4:onionwrapper-android-0.0.4.aar:d761854dac454616b3e0ca099b2cd17060365ce4316afe495cc7ae86b6c81d15',
-        'org.briarproject:onionwrapper-core:0.0.1:onionwrapper-core-0.0.1.jar:a1937506b00ee6620e909a500e5d004be81f94a6f7d7c898e1a9e841a8ae8a2a',
+        'org.briarproject:onionwrapper-core:0.0.4:onionwrapper-core-0.0.4.jar:28a01a62e96aa763989a8afc325abd3bee54f8021269f91aa48b247a6e717870',
         'org.briarproject:snowflake-android:2.5.1:snowflake-android-2.5.1.jar:88ec81c17b1b6fa884d06839dec0330e328b45c89f88c970a213ce91ca8eac87',
         'org.briarproject:tor-android:0.4.7.13-2:tor-android-0.4.7.13-2.jar:453fd463b234a2104edd7f0d02d0649cbb5c5efbe47a76df3828f55a3f90f8b5',
         'org.checkerframework:checker-compat-qual:2.5.5:checker-compat-qual-2.5.5.jar:11d134b245e9cacc474514d2d66b5b8618f8039a1465cdc55bbc0b34e0008b7a',
@@ -41,6 +42,7 @@ dependencyVerification {
         'org.jacoco:org.jacoco.ant:0.8.7:org.jacoco.ant-0.8.7.jar:97ca96a382c3f23a44d8eb4c4e6c3742a30cb8005774a76ced0fc4806ce49605',
         'org.jacoco:org.jacoco.core:0.8.7:org.jacoco.core-0.8.7.jar:ad7739b5fb5969aa1a8aead3d74ed54dc82ed012f1f10f336bd1b96e71c1a13c',
         'org.jacoco:org.jacoco.report:0.8.7:org.jacoco.report-0.8.7.jar:cc89258623700a6c932592153cb528785876b6da183d5431f97efbba6f020e5b',
+        'org.jetbrains.kotlin:kotlin-reflect:1.6.10:kotlin-reflect-1.6.10.jar:3277ac102ae17aad10a55abec75ff5696c8d109790396434b496e75087854203',
         'org.jetbrains.kotlin:kotlin-stdlib-common:1.7.0:kotlin-stdlib-common-1.7.0.jar:59c6ff64fe9a6604afce03e8aaa75f83586c6030ac71fb0b34ee7cdefed3618f',
         'org.jetbrains.kotlin:kotlin-stdlib-common:1.8.0:kotlin-stdlib-common-1.8.0.jar:78ef93b59e603cc0fe51def9bd4c037b07cbace3b3b7806d1a490a42bc1f4cb2',
         'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.0:kotlin-stdlib-jdk7-1.7.0.jar:07e91be9b2ca20672d2bdb7e181b766e73453a2da13492b5ddaee8fa47aea239',

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

@@ -54,6 +54,38 @@ public interface CryptoComponent {
 			KeyPair ourKeyPair, byte[]... inputs)
 			throws GeneralSecurityException;
 
+	/**
+	 * Derives a shared secret from two static and two ephemeral key pairs.
+	 * <p>
+	 * Do not use this method for new protocols. The shared secret can be
+	 * re-derived using the ephemeral public keys and both static private
+	 * keys, so keys derived from the shared secret should not be used if
+	 * forward secrecy is required. Use {@link #deriveSharedSecret(String,
+	 * PublicKey, PublicKey, KeyPair, KeyPair, boolean, byte[]...)} instead.
+	 * <p>
+	 * TODO: Remove this after a reasonable migration period (added 2023-03-10).
+	 * <p>
+	 *
+	 * @param label A namespaced label indicating the purpose of this shared
+	 * secret, to prevent it from being repurposed or colliding with a shared
+	 * secret derived for another purpose
+	 * @param theirStaticPublicKey The static public key of the remote party
+	 * @param theirEphemeralPublicKey The ephemeral public key of the remote
+	 * party
+	 * @param ourStaticKeyPair The static key pair of the local party
+	 * @param ourEphemeralKeyPair The ephemeral key pair of the local party
+	 * @param alice True if the local party is Alice
+	 * @param inputs Additional inputs that will be included in the
+	 * derivation of the shared secret
+	 * @return The shared secret
+	 */
+	@Deprecated
+	SecretKey deriveSharedSecretBadly(String label,
+			PublicKey theirStaticPublicKey, PublicKey theirEphemeralPublicKey,
+			KeyPair ourStaticKeyPair, KeyPair ourEphemeralKeyPair,
+			boolean alice, byte[]... inputs)
+			throws GeneralSecurityException;
+
 	/**
 	 * Derives a shared secret from two static and two ephemeral key pairs.
 	 *

bramble-api/src/main/java/org/briarproject/bramble/api/network/NetworkStatus.java

@@ -2,6 +2,7 @@ package org.briarproject.bramble.api.network;
 
 import org.briarproject.nullsafety.NotNullByDefault;
 
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
 @Immutable
@@ -27,4 +28,20 @@ public class NetworkStatus {
 	public boolean isIpv6Only() {
 		return ipv6Only;
 	}
+
+	@Override
+	public int hashCode() {
+		return (connected ? 1 : 0) | (wifi ? 2 : 0) | (ipv6Only ? 4 : 0);
+	}
+
+	@Override
+	public boolean equals(@Nullable Object o) {
+		if (o instanceof NetworkStatus) {
+			NetworkStatus s = (NetworkStatus) o;
+			return connected == s.connected
+					&& wifi == s.wifi
+					&& ipv6Only == s.ipv6Only;
+		}
+		return false;
+	}
 }

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

@@ -32,8 +32,15 @@ public interface RecordReader {
 	 * 'accept' or 'ignore' predicates
 	 */
 	@Nullable
-	Record readRecord(Predicate<Record> accept, Predicate<Record> ignore)
+	Record readRecord(RecordPredicate accept, RecordPredicate ignore)
 			throws IOException;
 
 	void close() throws IOException;
+
+	/**
+	 * Interface that reifies the generic interface {@code Predicate<Record>}
+	 * for easier testing.
+	 */
+	interface RecordPredicate extends Predicate<Record> {
+	}
 }

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

@@ -1,16 +0,0 @@
-package org.briarproject.bramble.api.system;
-
-import org.briarproject.nullsafety.NotNullByDefault;
-
-@NotNullByDefault
-public interface LocationUtils {
-
-	/**
-	 * Get the country the device is currently located in, or "" if it cannot
-	 * be determined.
-	 * <p>
-	 * The country codes are formatted upper-case and as per <a href="
-	 * https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2">ISO 3166-1 alpha 2</a>.
-	 */
-	String getCurrentCountry();
-}

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

@@ -6,6 +6,7 @@ import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketAddress;
+import java.util.Locale;
 
 import javax.annotation.Nullable;
 
@@ -51,7 +52,7 @@ public class PrivacyUtils {
 	}
 
 	private static String scrubIpv6Address(byte[] ipv6) {
-		String hex = toHexString(ipv6).toLowerCase();
+		String hex = toHexString(ipv6).toLowerCase(Locale.US);
 		return hex.substring(0, 2) + "[scrubbed]" + hex.substring(30);
 	}
 

bramble-api/witness.gradle

@@ -4,7 +4,7 @@ dependencyVerification {
         'com.fasterxml.jackson.core:jackson-annotations:2.13.4:jackson-annotations-2.13.4.jar:ac5b27a634942391ca113850ee7db01df1499a240174021263501c05fc653b44',
         '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:2.43.2:dagger-2.43.2.jar:c89681f7cbbf8c527bf4ac2748515d617fdb54a1d425c08d914fdc28192b5fe4',
+        'com.google.dagger:dagger:2.45:dagger-2.45.jar:f011cae7d2c0fb7ea17c34e05bc10e768b1081a5892ad019cf1fdb0e125c49c1',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.13.2:junit-4.13.2.jar:8e495b634469d64fb8acfa3495a065cbacc8a0fff55ce1e31007be4c16dc57d3',
         'net.bytebuddy:byte-buddy:1.9.12:byte-buddy-1.9.12.jar:3688c3d434bebc3edc5516296a2ed0f47b65e451071b4afecad84f902f0efc11',
@@ -12,8 +12,8 @@ dependencyVerification {
         'org.apache-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
         'org.briarproject:null-safety:0.1:null-safety-0.1.jar:161760de5e838cb982bafa973df820675d4397098e9a91637a36a306d43ba011',
         'org.codehaus.mojo.signature:java16:1.1:java16-1.1.signature:53799223a2c98dba2d0add810bed76315460df285c69e4f397ae6098f87dd619',
-        'org.codehaus.mojo:animal-sniffer-ant-tasks:1.20:animal-sniffer-ant-tasks-1.20.jar:bb7d2498144118311d968bb08ff6fae3fc535fb1cb9cca8b8e9ea65b189422ac',
+        'org.codehaus.mojo:animal-sniffer-ant-tasks:1.22:animal-sniffer-ant-tasks-1.22.jar:3f6afeb3e09301d2d7179ed1db21e3ad8846c1e38415ad832a395138ae3f4218',
-        'org.codehaus.mojo:animal-sniffer:1.20:animal-sniffer-1.20.jar:80c422523c38db91260c6d78e5ee4b012862ab61cc55020c9e243dd7b5c62249',
+        'org.codehaus.mojo:animal-sniffer:1.22:animal-sniffer-1.22.jar:f18c11a25bdd8b520b9c6a28cbb6f33007c812ab0051b6be3f0778e660aa501c',
         'org.hamcrest:hamcrest-core:2.1:hamcrest-core-2.1.jar:e09109e54a289d88506b9bfec987ddd199f4217c9464132668351b9a4f00bee9',
         'org.hamcrest:hamcrest-library:2.1:hamcrest-library-2.1.jar:b7e2b6895b3b679f0e47b6380fda391b225e9b78505db9d8bdde8d3cc8d52a21',
         'org.hamcrest:hamcrest:2.1:hamcrest-2.1.jar:ba93b2e3a562322ba432f0a1b53addcc55cb188253319a020ed77f824e692050',
@@ -24,6 +24,6 @@ dependencyVerification {
         'org.jmock:jmock:2.12.0:jmock-2.12.0.jar:266d07314c0cd343c46ff8a55601272de8cf406807caf55e6f313295f83d10be',
         'org.objenesis:objenesis:3.0.1:objenesis-3.0.1.jar:7a8ff780b9ff48415d7c705f60030b0acaa616e7f823c98eede3b63508d4e984',
         'org.ow2.asm:asm:7.1:asm-7.1.jar:4ab2fa2b6d2cc9ccb1eaa05ea329c407b47b13ed2915f62f8c4b8cc96258d4de',
-        'org.ow2.asm:asm:9.1:asm-9.1.jar:cda4de455fab48ff0bcb7c48b4639447d4de859a7afc30a094a986f0936beba2',
+        'org.ow2.asm:asm:9.3:asm-9.3.jar:1263369b59e29c943918de11d6d6152e2ec6085ce63e5710516f8c67d368e4bc',
     ]
 }

bramble-core/build.gradle

@@ -28,7 +28,7 @@ dependencies {
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
 
 	testImplementation 'org.hsqldb:hsqldb:2.3.5' // The last version that supports Java 1.6
-	testImplementation 'net.jodah:concurrentunit:0.4.2'
+	testImplementation 'net.jodah:concurrentunit:0.4.6'
 	testImplementation "junit:junit:$junit_version"
 	testImplementation "org.jmock:jmock:$jmock_version"
 	testImplementation "org.jmock:jmock-junit4:$jmock_version"

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

@@ -1,7 +1,6 @@
 package org.briarproject.bramble.contact;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactExchangeManager;
@@ -24,6 +23,7 @@ import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.api.record.Record;
 import org.briarproject.bramble.api.record.RecordReader;
+import org.briarproject.bramble.api.record.RecordReader.RecordPredicate;
 import org.briarproject.bramble.api.record.RecordReaderFactory;
 import org.briarproject.bramble.api.record.RecordWriter;
 import org.briarproject.bramble.api.record.RecordWriterFactory;
@@ -61,12 +61,12 @@ class ContactExchangeManagerImpl implements ContactExchangeManager {
 			getLogger(ContactExchangeManagerImpl.class.getName());
 
 	// Accept records with current protocol version, known record type
-	private static final Predicate<Record> ACCEPT = r ->
+	private static final RecordPredicate ACCEPT = r ->
 			r.getProtocolVersion() == PROTOCOL_VERSION &&
 					isKnownRecordType(r.getRecordType());
 
 	// Ignore records with current protocol version, unknown record type
-	private static final Predicate<Record> IGNORE = r ->
+	private static final RecordPredicate IGNORE = r ->
 			r.getProtocolVersion() == PROTOCOL_VERSION &&
 					!isKnownRecordType(r.getRecordType());
 

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

@@ -5,14 +5,31 @@ import static org.briarproject.bramble.api.crypto.CryptoConstants.MAC_BYTES;
 interface HandshakeConstants {
 
 	/**
-	 * The current version of the handshake protocol.
+	 * The current major version of the handshake protocol.
 	 */
-	byte PROTOCOL_VERSION = 0;
+	byte PROTOCOL_MAJOR_VERSION = 0;
 
 	/**
-	 * Label for deriving the master key.
+	 * The current minor version of the handshake protocol.
 	 */
-	String MASTER_KEY_LABEL = "org.briarproject.bramble.handshake/MASTER_KEY";
+	byte PROTOCOL_MINOR_VERSION = 1;
+
+	/**
+	 * Label for deriving the master key when using the deprecated v0.0 key
+	 * derivation method.
+	 * <p>
+	 * TODO: Remove this after a reasonable migration period (added 2023-03-10).
+	 */
+	@Deprecated
+	String MASTER_KEY_LABEL_0_0 =
+			"org.briarproject.bramble.handshake/MASTER_KEY";
+
+	/**
+	 * Label for deriving the master key when using the v0.1 key derivation
+	 * method.
+	 */
+	String MASTER_KEY_LABEL_0_1 =
+			"org.briarproject.bramble.handshake/MASTER_KEY_0_1";
 
 	/**
 	 * Label for deriving Alice's proof of ownership from the master key.

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

@@ -13,11 +13,26 @@ interface HandshakeCrypto {
 	KeyPair generateEphemeralKeyPair();
 
 	/**
-	 * Derives the master key from the given static and ephemeral keys.
+	 * Derives the master key from the given static and ephemeral keys using
+	 * the deprecated v0.0 key derivation method.
+	 * <p>
+	 * TODO: Remove this after a reasonable migration period (added 2023-03-10).
 	 *
 	 * @param alice Whether the local peer is Alice
 	 */
-	SecretKey deriveMasterKey(PublicKey theirStaticPublicKey,
+	@Deprecated
+	SecretKey deriveMasterKey_0_0(PublicKey theirStaticPublicKey,
+			PublicKey theirEphemeralPublicKey, KeyPair ourStaticKeyPair,
+			KeyPair ourEphemeralKeyPair, boolean alice)
+			throws GeneralSecurityException;
+
+	/**
+	 * Derives the master key from the given static and ephemeral keys using
+	 * the v0.1 key derivation method.
+	 *
+	 * @param alice Whether the local peer is Alice
+	 */
+	SecretKey deriveMasterKey_0_1(PublicKey theirStaticPublicKey,
 			PublicKey theirEphemeralPublicKey, KeyPair ourStaticKeyPair,
 			KeyPair ourEphemeralKeyPair, boolean alice)
 			throws GeneralSecurityException;

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

@@ -13,7 +13,8 @@ import javax.inject.Inject;
 
 import static org.briarproject.bramble.contact.HandshakeConstants.ALICE_PROOF_LABEL;
 import static org.briarproject.bramble.contact.HandshakeConstants.BOB_PROOF_LABEL;
-import static org.briarproject.bramble.contact.HandshakeConstants.MASTER_KEY_LABEL;
+import static org.briarproject.bramble.contact.HandshakeConstants.MASTER_KEY_LABEL_0_0;
+import static org.briarproject.bramble.contact.HandshakeConstants.MASTER_KEY_LABEL_0_1;
 
 @Immutable
 @NotNullByDefault
@@ -32,7 +33,8 @@ class HandshakeCryptoImpl implements HandshakeCrypto {
 	}
 
 	@Override
-	public SecretKey deriveMasterKey(PublicKey theirStaticPublicKey,
+	@Deprecated
+	public SecretKey deriveMasterKey_0_0(PublicKey theirStaticPublicKey,
 			PublicKey theirEphemeralPublicKey, KeyPair ourStaticKeyPair,
 			KeyPair ourEphemeralKeyPair, boolean alice) throws
 			GeneralSecurityException {
@@ -46,9 +48,29 @@ class HandshakeCryptoImpl implements HandshakeCrypto {
 				alice ? ourEphemeral : theirEphemeral,
 				alice ? theirEphemeral : ourEphemeral
 		};
-		return crypto.deriveSharedSecret(MASTER_KEY_LABEL, theirStaticPublicKey,
+		return crypto.deriveSharedSecretBadly(MASTER_KEY_LABEL_0_0,
-				theirEphemeralPublicKey, ourStaticKeyPair, ourEphemeralKeyPair,
+				theirStaticPublicKey, theirEphemeralPublicKey,
-				alice, inputs);
+				ourStaticKeyPair, ourEphemeralKeyPair, alice, inputs);
+	}
+
+	@Override
+	public SecretKey deriveMasterKey_0_1(PublicKey theirStaticPublicKey,
+			PublicKey theirEphemeralPublicKey, KeyPair ourStaticKeyPair,
+			KeyPair ourEphemeralKeyPair, boolean alice) throws
+			GeneralSecurityException {
+		byte[] theirStatic = theirStaticPublicKey.getEncoded();
+		byte[] theirEphemeral = theirEphemeralPublicKey.getEncoded();
+		byte[] ourStatic = ourStaticKeyPair.getPublic().getEncoded();
+		byte[] ourEphemeral = ourEphemeralKeyPair.getPublic().getEncoded();
+		byte[][] inputs = {
+				alice ? ourStatic : theirStatic,
+				alice ? theirStatic : ourStatic,
+				alice ? ourEphemeral : theirEphemeral,
+				alice ? theirEphemeral : ourEphemeral
+		};
+		return crypto.deriveSharedSecret(MASTER_KEY_LABEL_0_1,
+				theirStaticPublicKey, theirEphemeralPublicKey,
+				ourStaticKeyPair, ourEphemeralKeyPair, alice, inputs);
 	}
 
 	@Override

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

@@ -2,7 +2,6 @@ package org.briarproject.bramble.contact;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.Pair;
-import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.contact.HandshakeManager;
 import org.briarproject.bramble.api.contact.PendingContact;
@@ -12,12 +11,12 @@ import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.TransportCrypto;
-import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.record.Record;
 import org.briarproject.bramble.api.record.RecordReader;
+import org.briarproject.bramble.api.record.RecordReader.RecordPredicate;
 import org.briarproject.bramble.api.record.RecordReaderFactory;
 import org.briarproject.bramble.api.record.RecordWriter;
 import org.briarproject.bramble.api.record.RecordWriterFactory;
@@ -28,15 +27,20 @@ import java.io.EOFException;
 import java.io.IOException;
 import java.io.InputStream;
 import java.security.GeneralSecurityException;
+import java.util.List;
 
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
+import static java.util.Arrays.asList;
+import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.api.crypto.CryptoConstants.MAX_AGREEMENT_PUBLIC_KEY_BYTES;
 import static org.briarproject.bramble.contact.HandshakeConstants.PROOF_BYTES;
-import static org.briarproject.bramble.contact.HandshakeConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.contact.HandshakeConstants.PROTOCOL_MAJOR_VERSION;
-import static org.briarproject.bramble.contact.HandshakeRecordTypes.EPHEMERAL_PUBLIC_KEY;
+import static org.briarproject.bramble.contact.HandshakeConstants.PROTOCOL_MINOR_VERSION;
-import static org.briarproject.bramble.contact.HandshakeRecordTypes.PROOF_OF_OWNERSHIP;
+import static org.briarproject.bramble.contact.HandshakeRecordTypes.RECORD_TYPE_EPHEMERAL_PUBLIC_KEY;
+import static org.briarproject.bramble.contact.HandshakeRecordTypes.RECORD_TYPE_MINOR_VERSION;
+import static org.briarproject.bramble.contact.HandshakeRecordTypes.RECORD_TYPE_PROOF_OF_OWNERSHIP;
 import static org.briarproject.bramble.util.ValidationUtils.checkLength;
 
 @Immutable
@@ -44,12 +48,14 @@ import static org.briarproject.bramble.util.ValidationUtils.checkLength;
 class HandshakeManagerImpl implements HandshakeManager {
 
 	// Ignore records with current protocol version, unknown record type
-	private static final Predicate<Record> IGNORE = r ->
+	private static final RecordPredicate IGNORE = r ->
-			r.getProtocolVersion() == PROTOCOL_VERSION &&
+			r.getProtocolVersion() == PROTOCOL_MAJOR_VERSION &&
 					!isKnownRecordType(r.getRecordType());
 
 	private static boolean isKnownRecordType(byte type) {
-		return type == EPHEMERAL_PUBLIC_KEY || type == PROOF_OF_OWNERSHIP;
+		return type == RECORD_TYPE_EPHEMERAL_PUBLIC_KEY ||
+				type == RECORD_TYPE_PROOF_OF_OWNERSHIP ||
+				type == RECORD_TYPE_MINOR_VERSION;
 	}
 
 	private final TransactionManager db;
@@ -61,7 +67,7 @@ class HandshakeManagerImpl implements HandshakeManager {
 	private final RecordWriterFactory recordWriterFactory;
 
 	@Inject
-	HandshakeManagerImpl(DatabaseComponent db,
+	HandshakeManagerImpl(TransactionManager db,
 			IdentityManager identityManager,
 			ContactManager contactManager,
 			TransportCrypto transportCrypto,
@@ -95,19 +101,31 @@ class HandshakeManagerImpl implements HandshakeManager {
 				.createRecordWriter(out.getOutputStream());
 		KeyPair ourEphemeralKeyPair =
 				handshakeCrypto.generateEphemeralKeyPair();
-		PublicKey theirEphemeralPublicKey;
+		Pair<Byte, PublicKey> theirMinorVersionAndKey;
 		if (alice) {
+			sendMinorVersion(recordWriter);
 			sendPublicKey(recordWriter, ourEphemeralKeyPair.getPublic());
-			theirEphemeralPublicKey = receivePublicKey(recordReader);
+			theirMinorVersionAndKey = receiveMinorVersionAndKey(recordReader);
 		} else {
-			theirEphemeralPublicKey = receivePublicKey(recordReader);
+			theirMinorVersionAndKey = receiveMinorVersionAndKey(recordReader);
+			sendMinorVersion(recordWriter);
 			sendPublicKey(recordWriter, ourEphemeralKeyPair.getPublic());
 		}
+		byte theirMinorVersion = theirMinorVersionAndKey.getFirst();
+		PublicKey theirEphemeralPublicKey = theirMinorVersionAndKey.getSecond();
 		SecretKey masterKey;
 		try {
-			masterKey = handshakeCrypto.deriveMasterKey(theirStaticPublicKey,
+			if (theirMinorVersion > 0) {
-					theirEphemeralPublicKey, ourStaticKeyPair,
+				masterKey = handshakeCrypto.deriveMasterKey_0_1(
-					ourEphemeralKeyPair, alice);
+						theirStaticPublicKey, theirEphemeralPublicKey,
+						ourStaticKeyPair, ourEphemeralKeyPair, alice);
+			} else {
+				// TODO: Remove this branch after a reasonable migration
+				//  period (added 2023-03-10).
+				masterKey = handshakeCrypto.deriveMasterKey_0_0(
+						theirStaticPublicKey, theirEphemeralPublicKey,
+						ourStaticKeyPair, ourEphemeralKeyPair, alice);
+			}
 		} catch (GeneralSecurityException e) {
 			throw new FormatException();
 		}
@@ -128,34 +146,91 @@ class HandshakeManagerImpl implements HandshakeManager {
 	}
 
 	private void sendPublicKey(RecordWriter w, PublicKey k) throws IOException {
-		w.writeRecord(new Record(PROTOCOL_VERSION, EPHEMERAL_PUBLIC_KEY,
+		w.writeRecord(new Record(PROTOCOL_MAJOR_VERSION,
-				k.getEncoded()));
+				RECORD_TYPE_EPHEMERAL_PUBLIC_KEY, k.getEncoded()));
 		w.flush();
 	}
 
-	private PublicKey receivePublicKey(RecordReader r) throws IOException {
+	/**
-		byte[] key = readRecord(r, EPHEMERAL_PUBLIC_KEY).getPayload();
+	 * Receives the remote peer's protocol minor version and ephemeral public
+	 * key.
+	 * <p>
+	 * In version 0.1 of the protocol, each peer sends a minor version record
+	 * followed by an ephemeral public key record.
+	 * <p>
+	 * In version 0.0 of the protocol, each peer sends an ephemeral public key
+	 * record without a preceding minor version record.
+	 * <p>
+	 * Therefore the remote peer's minor version must be non-zero if a minor
+	 * version record is received, and is assumed to be zero if no minor
+	 * version record is received.
+	 */
+	private Pair<Byte, PublicKey> receiveMinorVersionAndKey(RecordReader r)
+			throws IOException {
+		byte theirMinorVersion;
+		PublicKey theirEphemeralPublicKey;
+		// The first record can be either a minor version record or an
+		// ephemeral public key record
+		Record first = readRecord(r, asList(RECORD_TYPE_MINOR_VERSION,
+				RECORD_TYPE_EPHEMERAL_PUBLIC_KEY));
+		if (first.getRecordType() == RECORD_TYPE_MINOR_VERSION) {
+			// The payload must be a single byte giving the remote peer's
+			// protocol minor version, which must be non-zero
+			byte[] payload = first.getPayload();
+			checkLength(payload, 1);
+			theirMinorVersion = payload[0];
+			if (theirMinorVersion == 0) throw new FormatException();
+			// The second record must be an ephemeral public key record
+			Record second = readRecord(r,
+					singletonList(RECORD_TYPE_EPHEMERAL_PUBLIC_KEY));
+			theirEphemeralPublicKey = parsePublicKey(second);
+		} else {
+			// The remote peer did not send a minor version record, so the
+			// remote peer's protocol minor version is assumed to be zero
+			// TODO: Remove this branch after a reasonable migration period
+			//  (added 2023-03-10).
+			theirMinorVersion = 0;
+			theirEphemeralPublicKey = parsePublicKey(first);
+		}
+		return new Pair<>(theirMinorVersion, theirEphemeralPublicKey);
+	}
+
+	private PublicKey parsePublicKey(Record rec) throws IOException {
+		if (rec.getRecordType() != RECORD_TYPE_EPHEMERAL_PUBLIC_KEY) {
+			throw new AssertionError();
+		}
+		byte[] key = rec.getPayload();
 		checkLength(key, 1, MAX_AGREEMENT_PUBLIC_KEY_BYTES);
 		return new AgreementPublicKey(key);
 	}
 
 	private void sendProof(RecordWriter w, byte[] proof) throws IOException {
-		w.writeRecord(new Record(PROTOCOL_VERSION, PROOF_OF_OWNERSHIP, proof));
+		w.writeRecord(new Record(PROTOCOL_MAJOR_VERSION,
+				RECORD_TYPE_PROOF_OF_OWNERSHIP, proof));
 		w.flush();
 	}
 
 	private byte[] receiveProof(RecordReader r) throws IOException {
-		byte[] proof = readRecord(r, PROOF_OF_OWNERSHIP).getPayload();
+		Record rec = readRecord(r,
+				singletonList(RECORD_TYPE_PROOF_OF_OWNERSHIP));
+		byte[] proof = rec.getPayload();
 		checkLength(proof, PROOF_BYTES, PROOF_BYTES);
 		return proof;
 	}
 
-	private Record readRecord(RecordReader r, byte expectedType)
+	private void sendMinorVersion(RecordWriter w) throws IOException {
+		w.writeRecord(new Record(PROTOCOL_MAJOR_VERSION,
+				RECORD_TYPE_MINOR_VERSION,
+				new byte[] {PROTOCOL_MINOR_VERSION}));
+		w.flush();
+	}
+
+	private Record readRecord(RecordReader r, List<Byte> expectedTypes)
 			throws IOException {
-		// Accept records with current protocol version, expected type only
+		// Accept records with current protocol version, expected types only
-		Predicate<Record> accept = rec ->
+		RecordPredicate accept = rec ->
-				rec.getProtocolVersion() == PROTOCOL_VERSION &&
+				rec.getProtocolVersion() == PROTOCOL_MAJOR_VERSION &&
-						rec.getRecordType() == expectedType;
+						expectedTypes.contains(rec.getRecordType());
 		Record rec = r.readRecord(accept, IGNORE);
 		if (rec == null) throw new EOFException();
 		return rec;

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

@@ -5,7 +5,9 @@ package org.briarproject.bramble.contact;
  */
 interface HandshakeRecordTypes {
 
-	byte EPHEMERAL_PUBLIC_KEY = 0;
+	byte RECORD_TYPE_EPHEMERAL_PUBLIC_KEY = 0;
 
-	byte PROOF_OF_OWNERSHIP = 1;
+	byte RECORD_TYPE_PROOF_OF_OWNERSHIP = 1;
+
+	byte RECORD_TYPE_MINOR_VERSION = 2;
 }

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

@@ -34,6 +34,7 @@ import java.security.NoSuchAlgorithmException;
 import java.security.Provider;
 import java.security.SecureRandom;
 import java.security.Security;
+import java.util.Locale;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
@@ -222,7 +223,8 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public SecretKey deriveSharedSecret(String label,
+	@Deprecated
+	public SecretKey deriveSharedSecretBadly(String label,
 			PublicKey theirStaticPublicKey, PublicKey theirEphemeralPublicKey,
 			KeyPair ourStaticKeyPair, KeyPair ourEphemeralKeyPair,
 			boolean alice, byte[]... inputs) throws GeneralSecurityException {
@@ -250,6 +252,35 @@ class CryptoComponentImpl implements CryptoComponent {
 		return new SecretKey(hash);
 	}
 
+	@Override
+	public SecretKey deriveSharedSecret(String label,
+			PublicKey theirStaticPublicKey, PublicKey theirEphemeralPublicKey,
+			KeyPair ourStaticKeyPair, KeyPair ourEphemeralKeyPair,
+			boolean alice, byte[]... inputs) throws GeneralSecurityException {
+		PrivateKey ourStaticPrivateKey = ourStaticKeyPair.getPrivate();
+		PrivateKey ourEphemeralPrivateKey = ourEphemeralKeyPair.getPrivate();
+		byte[][] hashInputs = new byte[inputs.length + 3][];
+		// Alice ephemeral/Bob ephemeral
+		hashInputs[0] = performRawKeyAgreement(ourEphemeralPrivateKey,
+				theirEphemeralPublicKey);
+		// Alice static/Bob ephemeral, Bob static/Alice ephemeral
+		if (alice) {
+			hashInputs[1] = performRawKeyAgreement(ourStaticPrivateKey,
+					theirEphemeralPublicKey);
+			hashInputs[2] = performRawKeyAgreement(ourEphemeralPrivateKey,
+					theirStaticPublicKey);
+		} else {
+			hashInputs[1] = performRawKeyAgreement(ourEphemeralPrivateKey,
+					theirStaticPublicKey);
+			hashInputs[2] = performRawKeyAgreement(ourStaticPrivateKey,
+					theirEphemeralPublicKey);
+		}
+		arraycopy(inputs, 0, hashInputs, 3, inputs.length);
+		byte[] hash = hash(label, hashInputs);
+		if (hash.length != SecretKey.LENGTH) throw new IllegalStateException();
+		return new SecretKey(hash);
+	}
+
 	@Override
 	public byte[] sign(String label, byte[] toSign, PrivateKey privateKey)
 			throws GeneralSecurityException {
@@ -470,7 +501,7 @@ class CryptoComponentImpl implements CryptoComponent {
 		arraycopy(publicKey, 0, address, 0, publicKey.length);
 		arraycopy(checksum, 0, address, publicKey.length, ONION_CHECKSUM_BYTES);
 		address[address.length - 1] = ONION_HS_PROTOCOL_VERSION;
-		return Base32.encode(address).toLowerCase();
+		return Base32.encode(address).toLowerCase(Locale.US);
 	}
 
 }

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

@@ -1,11 +1,11 @@
 package org.briarproject.bramble.keyagreement;
 
-import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.record.Record;
 import org.briarproject.bramble.api.record.RecordReader;
+import org.briarproject.bramble.api.record.RecordReader.RecordPredicate;
 import org.briarproject.bramble.api.record.RecordReaderFactory;
 import org.briarproject.bramble.api.record.RecordWriter;
 import org.briarproject.bramble.api.record.RecordWriterFactory;
@@ -34,12 +34,12 @@ class KeyAgreementTransport {
 			Logger.getLogger(KeyAgreementTransport.class.getName());
 
 	// Accept records with current protocol version, known record type
-	private static final Predicate<Record> ACCEPT = r ->
+	private static final RecordPredicate ACCEPT = r ->
 			r.getProtocolVersion() == PROTOCOL_VERSION &&
 					isKnownRecordType(r.getRecordType());
 
 	// Ignore records with current protocol version, unknown record type
-	private static final Predicate<Record> IGNORE = r ->
+	private static final RecordPredicate IGNORE = r ->
 			r.getProtocolVersion() == PROTOCOL_VERSION &&
 					!isKnownRecordType(r.getRecordType());
 

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

@@ -0,0 +1,19 @@
+package org.briarproject.bramble.plugin.tor;
+
+import org.briarproject.onionwrapper.CircumventionProvider;
+import org.briarproject.onionwrapper.CircumventionProviderFactory;
+
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class CircumventionModule {
+
+	@Provides
+	@Singleton
+	CircumventionProvider provideCircumventionProvider() {
+		return CircumventionProviderFactory.createCircumventionProvider();
+	}
+}

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

@@ -24,11 +24,11 @@ import org.briarproject.bramble.api.rendezvous.KeyMaterialSource;
 import org.briarproject.bramble.api.rendezvous.RendezvousEndpoint;
 import org.briarproject.bramble.api.settings.Settings;
 import org.briarproject.bramble.api.settings.event.SettingsUpdatedEvent;
-import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.nullsafety.InterfaceNotNullByDefault;
 import org.briarproject.nullsafety.NotNullByDefault;
 import org.briarproject.onionwrapper.CircumventionProvider;
 import org.briarproject.onionwrapper.CircumventionProvider.BridgeType;
+import org.briarproject.onionwrapper.LocationUtils;
 import org.briarproject.onionwrapper.TorWrapper;
 import org.briarproject.onionwrapper.TorWrapper.HiddenServiceProperties;
 import org.briarproject.onionwrapper.TorWrapper.Observer;
@@ -311,6 +311,9 @@ class TorPlugin implements DuplexPlugin, EventListener {
 			tor.stop();
 		} catch (IOException e) {
 			logException(LOG, WARNING, e);
+		} catch (InterruptedException e) {
+			LOG.warning("Interrupted while stopping Tor");
+			Thread.currentThread().interrupt();
 		}
 	}
 
@@ -625,12 +628,23 @@ class TorPlugin implements DuplexPlugin, EventListener {
 		}
 
 		private synchronized State getState(TorState torState) {
-			if (torState == TorState.STARTING_STOPPING || !settingsChecked) {
+			// Treat TorState.STARTED as State.STARTING_STOPPING because it's
+			// only seen during startup, before TorWrapper#enableNetwork() is
+			// called for the first time. TorState.NOT_STARTED and
+			// TorState.STOPPED are mapped to State.STARTING_STOPPING because
+			// that's the State before we've started and after we've stopped.
+			if (torState == TorState.NOT_STARTED ||
+					torState == TorState.STARTING ||
+					torState == TorState.STARTED ||
+					torState == TorState.STOPPING ||
+					torState == TorState.STOPPED ||
+					!settingsChecked) {
 				return STARTING_STOPPING;
 			}
 			if (reasonsDisabled != 0) return DISABLED;
 			if (torState == TorState.CONNECTING) return ENABLING;
 			if (torState == TorState.CONNECTED) return ACTIVE;
+			// The plugin is enabled in settings but the device is offline
 			return INACTIVE;
 		}
 

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

@@ -17,10 +17,10 @@ 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.Clock;
-import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.WakefulIoExecutor;
 import org.briarproject.nullsafety.NotNullByDefault;
 import org.briarproject.onionwrapper.CircumventionProvider;
+import org.briarproject.onionwrapper.LocationUtils;
 
 import java.io.File;
 import java.util.concurrent.Executor;

bramble-core/src/main/java/org/briarproject/bramble/record/RecordReaderImpl.java

@@ -1,7 +1,6 @@
 package org.briarproject.bramble.record;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.record.Record;
 import org.briarproject.bramble.api.record.RecordReader;
 import org.briarproject.bramble.util.ByteUtils;
@@ -45,7 +44,7 @@ class RecordReaderImpl implements RecordReader {
 
 	@Nullable
 	@Override
-	public Record readRecord(Predicate<Record> accept, Predicate<Record> ignore)
+	public Record readRecord(RecordPredicate accept, RecordPredicate ignore)
 			throws IOException {
 		while (true) {
 			if (eof()) return null;

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

@@ -1,10 +1,10 @@
 package org.briarproject.bramble.sync;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.record.Record;
 import org.briarproject.bramble.api.record.RecordReader;
+import org.briarproject.bramble.api.record.RecordReader.RecordPredicate;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageFactory;
@@ -41,12 +41,12 @@ import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
 class SyncRecordReaderImpl implements SyncRecordReader {
 
 	// Accept records with current protocol version, known record type
-	private static final Predicate<Record> ACCEPT = r ->
+	private static final RecordPredicate ACCEPT = r ->
 			r.getProtocolVersion() == PROTOCOL_VERSION &&
 					isKnownRecordType(r.getRecordType());
 
 	// Ignore records with current protocol version, unknown record type
-	private static final Predicate<Record> IGNORE = r ->
+	private static final RecordPredicate IGNORE = r ->
 			r.getProtocolVersion() == PROTOCOL_VERSION &&
 					!isKnownRecordType(r.getRecordType());
 

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

@@ -22,6 +22,7 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.InvalidMessageException;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.validation.IncomingMessageHook;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientMajorVersion;
@@ -36,17 +37,20 @@ import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Locale;
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.TreeSet;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static java.util.Collections.emptyList;
+import static java.util.logging.Logger.getLogger;
 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;
@@ -58,6 +62,9 @@ import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_
 class ClientVersioningManagerImpl implements ClientVersioningManager,
 		Service, OpenDatabaseHook, ContactHook, IncomingMessageHook {
 
+	private static final Logger LOG =
+			getLogger(ClientVersioningManagerImpl.class.getName());
+
 	private final DatabaseComponent db;
 	private final ClientHelper clientHelper;
 	private final ContactGroupFactory contactGroupFactory;
@@ -128,12 +135,68 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 
 	@Override
 	public void onDatabaseOpened(Transaction txn) throws DbException {
+		LOG.info("onDatabaseOpened " + localGroup.getId());
+		for (Contact c : db.getContacts(txn)) {
+			try {
+				// FIXME: DO NOT MERGE, this logs the contact name and alias
+				LOG.info(String.format(Locale.US,
+						"find latest updates for %d: %s (%s)",
+						c.getId().getInt(),
+						c.getAuthor().getName(),
+						c.getAlias()));
+				LatestUpdates latestUpdates = findLatestUpdates(txn, c.getId());
+				if (latestUpdates == null) {
+					LOG.info("none found");
+				} else {
+					if (latestUpdates.local != null) {
+						MessageStatus status = db.getMessageStatus(txn,
+								c.getId(), latestUpdates.local.messageId);
+						LOG.info(String.format(Locale.US,
+								"local: %s; sent: %b; seen: %b%n",
+								latestUpdates.local.messageId,
+								status.isSent(),
+								status.isSeen()));
+						Update update =
+								loadUpdate(txn, latestUpdates.local.messageId);
+						printUpdate(update);
+					}
+					if (latestUpdates.remote != null) {
+						MessageStatus status = db.getMessageStatus(txn,
+								c.getId(), latestUpdates.remote.messageId);
+						LOG.info(String.format(Locale.US,
+								"remote: %s; sent: %b; seen: %b%n",
+								latestUpdates.remote.messageId,
+								status.isSent(),
+								status.isSeen()));
+						Update update =
+								loadUpdate(txn, latestUpdates.remote.messageId);
+						printUpdate(update);
+					}
+				}
+			} catch (FormatException e) {
+				throw new RuntimeException(e);
+			}
+		}
 		if (db.containsGroup(txn, localGroup.getId())) return;
 		db.addGroup(txn, localGroup);
 		// Set things up for any pre-existing contacts
 		for (Contact c : db.getContacts(txn)) addingContact(txn, c);
 	}
 
+	private void printUpdate(Update update) {
+		LOG.info(String.format(Locale.US, "update version: %d%n",
+				update.updateVersion));
+		for (ClientState state : update.states) {
+			LOG.info(String.format(Locale.US,
+					"id: %s, major: %d, minor: %d, active: %b, %n",
+					state.clientVersion.getClientId().getString(),
+					state.clientVersion.getClientMajorVersion()
+							.getMajorVersion(),
+					state.clientVersion.getMinorVersion(),
+					state.active));
+		}
+	}
+
 	@Override
 	public void startService() throws ServiceException {
 		List<ClientVersion> versions = new ArrayList<>(clients);

bramble-core/src/main/java/org/briarproject/onionwrapper/CircumventionModule.java

@@ -1,17 +0,0 @@
-package org.briarproject.onionwrapper;
-
-import javax.inject.Singleton;
-
-import dagger.Module;
-import dagger.Provides;
-
-@Module
-public class CircumventionModule {
-
-	@Provides
-	@Singleton
-	CircumventionProvider provideCircumventionProvider(
-			CircumventionProviderImpl provider) {
-		return provider;
-	}
-}

bramble-core/src/test/java/org/briarproject/bramble/contact/HandshakeManagerImplTest.java

@@ -0,0 +1,316 @@
+package org.briarproject.bramble.contact;
+
+import org.briarproject.bramble.api.FormatException;
+import org.briarproject.bramble.api.contact.ContactManager;
+import org.briarproject.bramble.api.contact.HandshakeManager.HandshakeResult;
+import org.briarproject.bramble.api.contact.PendingContact;
+import org.briarproject.bramble.api.crypto.KeyPair;
+import org.briarproject.bramble.api.crypto.PrivateKey;
+import org.briarproject.bramble.api.crypto.PublicKey;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.crypto.TransportCrypto;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.db.TransactionManager;
+import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.record.Record;
+import org.briarproject.bramble.api.record.RecordReader;
+import org.briarproject.bramble.api.record.RecordReader.RecordPredicate;
+import org.briarproject.bramble.api.record.RecordReaderFactory;
+import org.briarproject.bramble.api.record.RecordWriter;
+import org.briarproject.bramble.api.record.RecordWriterFactory;
+import org.briarproject.bramble.api.transport.StreamWriter;
+import org.briarproject.bramble.test.BrambleMockTestCase;
+import org.briarproject.bramble.test.DbExpectations;
+import org.briarproject.bramble.test.PredicateMatcher;
+import org.jmock.Expectations;
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Arrays;
+
+import static org.briarproject.bramble.contact.HandshakeConstants.PROOF_BYTES;
+import static org.briarproject.bramble.contact.HandshakeConstants.PROTOCOL_MAJOR_VERSION;
+import static org.briarproject.bramble.contact.HandshakeConstants.PROTOCOL_MINOR_VERSION;
+import static org.briarproject.bramble.contact.HandshakeRecordTypes.RECORD_TYPE_EPHEMERAL_PUBLIC_KEY;
+import static org.briarproject.bramble.contact.HandshakeRecordTypes.RECORD_TYPE_MINOR_VERSION;
+import static org.briarproject.bramble.contact.HandshakeRecordTypes.RECORD_TYPE_PROOF_OF_OWNERSHIP;
+import static org.briarproject.bramble.test.TestUtils.getAgreementPrivateKey;
+import static org.briarproject.bramble.test.TestUtils.getAgreementPublicKey;
+import static org.briarproject.bramble.test.TestUtils.getPendingContact;
+import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
+import static org.briarproject.bramble.test.TestUtils.getSecretKey;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+
+public class HandshakeManagerImplTest extends BrambleMockTestCase {
+
+	private final TransactionManager db =
+			context.mock(TransactionManager.class);
+	private final IdentityManager identityManager =
+			context.mock(IdentityManager.class);
+	private final ContactManager contactManager =
+			context.mock(ContactManager.class);
+	private final TransportCrypto transportCrypto =
+			context.mock(TransportCrypto.class);
+	private final HandshakeCrypto handshakeCrypto =
+			context.mock(HandshakeCrypto.class);
+	private final RecordReaderFactory recordReaderFactory =
+			context.mock(RecordReaderFactory.class);
+	private final RecordWriterFactory recordWriterFactory =
+			context.mock(RecordWriterFactory.class);
+	private final RecordReader recordReader = context.mock(RecordReader.class);
+	private final RecordWriter recordWriter = context.mock(RecordWriter.class);
+	private final StreamWriter streamWriter = context.mock(StreamWriter.class);
+
+	private final PendingContact pendingContact = getPendingContact();
+	private final PublicKey theirStaticPublicKey =
+			pendingContact.getPublicKey();
+	private final PublicKey ourStaticPublicKey = getAgreementPublicKey();
+	private final PrivateKey ourStaticPrivateKey = getAgreementPrivateKey();
+	private final KeyPair ourStaticKeyPair =
+			new KeyPair(ourStaticPublicKey, ourStaticPrivateKey);
+	private final PublicKey theirEphemeralPublicKey = getAgreementPublicKey();
+	private final PublicKey ourEphemeralPublicKey = getAgreementPublicKey();
+	private final PrivateKey ourEphemeralPrivateKey = getAgreementPrivateKey();
+	private final KeyPair ourEphemeralKeyPair =
+			new KeyPair(ourEphemeralPublicKey, ourEphemeralPrivateKey);
+	private final SecretKey masterKey = getSecretKey();
+	private final byte[] ourProof = getRandomBytes(PROOF_BYTES);
+	private final byte[] theirProof = getRandomBytes(PROOF_BYTES);
+
+	private final InputStream in = new ByteArrayInputStream(new byte[0]);
+	private final OutputStream out = new ByteArrayOutputStream(0);
+
+	private final HandshakeManagerImpl handshakeManager =
+			new HandshakeManagerImpl(db, identityManager, contactManager,
+					transportCrypto, handshakeCrypto, recordReaderFactory,
+					recordWriterFactory);
+
+	@Test
+	public void testHandshakeAsAliceWithPeerVersion_0_1() throws Exception {
+		testHandshakeWithPeerVersion_0_1(true);
+	}
+
+	@Test
+	public void testHandshakeAsBobWithPeerVersion_0_1() throws Exception {
+		testHandshakeWithPeerVersion_0_1(false);
+	}
+
+	private void testHandshakeWithPeerVersion_0_1(boolean alice)
+			throws Exception {
+		expectPrepareForHandshake(alice);
+		expectSendMinorVersion();
+		expectSendKey();
+		// Remote peer sends minor version, so use new key derivation
+		expectReceiveMinorVersion();
+		expectReceiveKey();
+		expectDeriveMasterKey_0_1(alice);
+		expectDeriveProof(alice);
+		expectSendProof();
+		expectReceiveProof();
+		expectSendEof();
+		expectReceiveEof();
+		expectVerifyOwnership(alice, true);
+
+		HandshakeResult result = handshakeManager.handshake(
+				pendingContact.getId(), in, streamWriter);
+
+		assertArrayEquals(masterKey.getBytes(),
+				result.getMasterKey().getBytes());
+		assertEquals(alice, result.isAlice());
+	}
+
+	@Test
+	public void testHandshakeAsAliceWithPeerVersion_0_0() throws Exception {
+		testHandshakeWithPeerVersion_0_0(true);
+	}
+
+	@Test
+	public void testHandshakeAsBobWithPeerVersion_0_0() throws Exception {
+		testHandshakeWithPeerVersion_0_0(false);
+	}
+
+	private void testHandshakeWithPeerVersion_0_0(boolean alice)
+			throws Exception {
+		expectPrepareForHandshake(alice);
+		expectSendMinorVersion();
+		expectSendKey();
+		// Remote peer does not send minor version, so use old key derivation
+		expectReceiveKey();
+		expectDeriveMasterKey_0_0(alice);
+		expectDeriveProof(alice);
+		expectSendProof();
+		expectReceiveProof();
+		expectSendEof();
+		expectReceiveEof();
+		expectVerifyOwnership(alice, true);
+
+		HandshakeResult result = handshakeManager.handshake(
+				pendingContact.getId(), in, streamWriter);
+
+		assertArrayEquals(masterKey.getBytes(),
+				result.getMasterKey().getBytes());
+		assertEquals(alice, result.isAlice());
+	}
+
+	@Test(expected = FormatException.class)
+	public void testProofOfOwnershipNotVerifiedAsAlice() throws Exception {
+		testProofOfOwnershipNotVerified(true);
+	}
+
+	@Test(expected = FormatException.class)
+	public void testProofOfOwnershipNotVerifiedAsBob() throws Exception {
+		testProofOfOwnershipNotVerified(false);
+	}
+
+	private void testProofOfOwnershipNotVerified(boolean alice)
+			throws Exception {
+		expectPrepareForHandshake(alice);
+		expectSendMinorVersion();
+		expectSendKey();
+		expectReceiveMinorVersion();
+		expectReceiveKey();
+		expectDeriveMasterKey_0_1(alice);
+		expectDeriveProof(alice);
+		expectSendProof();
+		expectReceiveProof();
+		expectSendEof();
+		expectReceiveEof();
+		expectVerifyOwnership(alice, false);
+
+		handshakeManager.handshake(pendingContact.getId(), in, streamWriter);
+	}
+
+	private void expectPrepareForHandshake(boolean alice) throws Exception {
+		Transaction txn = new Transaction(null, true);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(contactManager).getPendingContact(txn,
+					pendingContact.getId());
+			will(returnValue(pendingContact));
+			oneOf(identityManager).getHandshakeKeys(txn);
+			will(returnValue(ourStaticKeyPair));
+			oneOf(transportCrypto).isAlice(theirStaticPublicKey,
+					ourStaticKeyPair);
+			will(returnValue(alice));
+			oneOf(recordReaderFactory).createRecordReader(in);
+			will(returnValue(recordReader));
+			oneOf(streamWriter).getOutputStream();
+			will(returnValue(out));
+			oneOf(recordWriterFactory).createRecordWriter(out);
+			will(returnValue(recordWriter));
+			oneOf(handshakeCrypto).generateEphemeralKeyPair();
+			will(returnValue(ourEphemeralKeyPair));
+		}});
+	}
+
+	private void expectSendMinorVersion() throws Exception {
+		expectWriteRecord(new Record(PROTOCOL_MAJOR_VERSION,
+				RECORD_TYPE_MINOR_VERSION,
+				new byte[] {PROTOCOL_MINOR_VERSION}));
+	}
+
+	private void expectReceiveMinorVersion() throws Exception {
+		expectReadRecord(new Record(PROTOCOL_MAJOR_VERSION,
+				RECORD_TYPE_MINOR_VERSION,
+				new byte[] {PROTOCOL_MINOR_VERSION}));
+	}
+
+	private void expectSendKey() throws Exception {
+		expectWriteRecord(new Record(PROTOCOL_MAJOR_VERSION,
+				RECORD_TYPE_EPHEMERAL_PUBLIC_KEY,
+				ourEphemeralPublicKey.getEncoded()));
+	}
+
+	private void expectReceiveKey() throws Exception {
+		expectReadRecord(new Record(PROTOCOL_MAJOR_VERSION,
+				RECORD_TYPE_EPHEMERAL_PUBLIC_KEY,
+				theirEphemeralPublicKey.getEncoded()));
+	}
+
+	private void expectDeriveMasterKey_0_1(boolean alice) throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(handshakeCrypto).deriveMasterKey_0_1(theirStaticPublicKey,
+					theirEphemeralPublicKey, ourStaticKeyPair,
+					ourEphemeralKeyPair, alice);
+			will(returnValue(masterKey));
+		}});
+	}
+
+	private void expectDeriveMasterKey_0_0(boolean alice) throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(handshakeCrypto).deriveMasterKey_0_0(theirStaticPublicKey,
+					theirEphemeralPublicKey, ourStaticKeyPair,
+					ourEphemeralKeyPair, alice);
+			will(returnValue(masterKey));
+		}});
+	}
+
+	private void expectDeriveProof(boolean alice) {
+		context.checking(new Expectations() {{
+			oneOf(handshakeCrypto).proveOwnership(masterKey, alice);
+			will(returnValue(ourProof));
+		}});
+	}
+
+	private void expectSendProof() throws Exception {
+		expectWriteRecord(new Record(PROTOCOL_MAJOR_VERSION,
+				RECORD_TYPE_PROOF_OF_OWNERSHIP, ourProof));
+	}
+
+	private void expectReceiveProof() throws Exception {
+		expectReadRecord(new Record(PROTOCOL_MAJOR_VERSION,
+				RECORD_TYPE_PROOF_OF_OWNERSHIP, theirProof));
+	}
+
+	private void expectSendEof() throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(streamWriter).sendEndOfStream();
+		}});
+	}
+
+	private void expectReceiveEof() throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(recordReader).readRecord(with(any(RecordPredicate.class)),
+					with(any(RecordPredicate.class)));
+			will(returnValue(null));
+		}});
+	}
+
+	private void expectVerifyOwnership(boolean alice, boolean verified) {
+		context.checking(new Expectations() {{
+			oneOf(handshakeCrypto).verifyOwnership(masterKey, !alice,
+					theirProof);
+			will(returnValue(verified));
+		}});
+	}
+
+	private void expectWriteRecord(Record record) throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(recordWriter).writeRecord(with(new PredicateMatcher<>(
+					Record.class, r -> recordEquals(record, r))));
+			oneOf(recordWriter).flush();
+		}});
+	}
+
+	private boolean recordEquals(Record expected, Record actual) {
+		return expected.getProtocolVersion() == actual.getProtocolVersion() &&
+				expected.getRecordType() == actual.getRecordType() &&
+				Arrays.equals(expected.getPayload(), actual.getPayload());
+	}
+
+	private void expectReadRecord(Record record) throws Exception {
+		context.checking(new Expectations() {{
+			// Test that the `accept` predicate passed to the reader would
+			// accept the expected record
+			oneOf(recordReader).readRecord(with(new PredicateMatcher<>(
+							RecordPredicate.class, rp -> rp.test(record))),
+					with(any(RecordPredicate.class)));
+			will(returnValue(record));
+		}});
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/contact/PendingContactFactoryImplTest.java

@@ -13,6 +13,7 @@ import org.jmock.Expectations;
 import org.junit.Test;
 
 import java.security.GeneralSecurityException;
+import java.util.Locale;
 
 import static java.lang.System.arraycopy;
 import static org.briarproject.bramble.api.contact.HandshakeLinkConstants.BASE32_LINK_BYTES;
@@ -174,7 +175,7 @@ public class PendingContactFactoryImplTest extends BrambleMockTestCase {
 		rawLink[0] = (byte) formatVersion;
 		byte[] publicKeyBytes = publicKey.getEncoded();
 		arraycopy(publicKeyBytes, 0, rawLink, 1, publicKeyBytes.length);
-		String base32 = Base32.encode(rawLink).toLowerCase();
+		String base32 = Base32.encode(rawLink).toLowerCase(Locale.US);
 		assertEquals(BASE32_LINK_BYTES, base32.length());
 		return base32;
 	}

bramble-core/src/test/java/org/briarproject/bramble/crypto/KeyAgreementTest.java

@@ -60,6 +60,22 @@ public class KeyAgreementTest extends BrambleTestCase {
 		assertArrayEquals(aShared.getBytes(), bShared.getBytes());
 	}
 
+	@Test
+	public void testDerivesStaticEphemeralSharedSecretBadly() throws Exception {
+		String label = getRandomString(123);
+		KeyPair aStatic = crypto.generateAgreementKeyPair();
+		KeyPair aEphemeral = crypto.generateAgreementKeyPair();
+		KeyPair bStatic = crypto.generateAgreementKeyPair();
+		KeyPair bEphemeral = crypto.generateAgreementKeyPair();
+		SecretKey aShared = crypto.deriveSharedSecretBadly(label,
+				bStatic.getPublic(), bEphemeral.getPublic(), aStatic,
+				aEphemeral, true, inputs);
+		SecretKey bShared = crypto.deriveSharedSecretBadly(label,
+				aStatic.getPublic(), aEphemeral.getPublic(), bStatic,
+				bEphemeral, false, inputs);
+		assertArrayEquals(aShared.getBytes(), bShared.getBytes());
+	}
+
 	@Test
 	public void testDerivesStaticEphemeralSharedSecret() throws Exception {
 		String label = getRandomString(123);

bramble-core/src/test/java/org/briarproject/bramble/crypto/OnionEncodingTest.java

@@ -0,0 +1,30 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
+import org.junit.Test;
+
+import java.security.SecureRandom;
+import java.util.regex.Pattern;
+
+import static org.junit.Assert.assertTrue;
+
+public class OnionEncodingTest extends BrambleTestCase {
+
+	private static final Pattern ONION_V3 = Pattern.compile("[a-z2-7]{56}");
+
+	private final CryptoComponent crypto =
+			new CryptoComponentImpl(new TestSecureRandomProvider(), null);
+	private final SecureRandom secureRandom = new SecureRandom();
+
+	@Test
+	public void testHostnameIsValid() {
+		byte[] publicKey = new byte[32];
+		for (int i = 0; i < 100; i++) {
+			secureRandom.nextBytes(publicKey);
+			String onion = crypto.encodeOnion(publicKey);
+			assertTrue(onion, ONION_V3.matcher(onion).matches());
+		}
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/keyagreement/KeyAgreementTransportTest.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.keyagreement;
 
-import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.keyagreement.KeyAgreementConnection;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;
@@ -8,11 +7,13 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.record.Record;
 import org.briarproject.bramble.api.record.RecordReader;
+import org.briarproject.bramble.api.record.RecordReader.RecordPredicate;
 import org.briarproject.bramble.api.record.RecordReaderFactory;
 import org.briarproject.bramble.api.record.RecordWriter;
 import org.briarproject.bramble.api.record.RecordWriterFactory;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.CaptureArgumentAction;
+import org.briarproject.bramble.test.PredicateMatcher;
 import org.jmock.Expectations;
 import org.jmock.imposters.ByteBuddyClassImposteriser;
 import org.junit.Test;
@@ -21,8 +22,6 @@ import java.io.InputStream;
 import java.io.OutputStream;
 import java.util.concurrent.atomic.AtomicReference;
 
-import javax.annotation.Nullable;
-
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.api.keyagreement.RecordTypes.ABORT;
 import static org.briarproject.bramble.api.keyagreement.RecordTypes.CONFIRM;
@@ -119,7 +118,7 @@ public class KeyAgreementTransportTest extends BrambleMockTestCase {
 	public void testReceiveKeyThrowsExceptionIfAtEndOfStream()
 			throws Exception {
 		setup();
-		expectReadRecord(null);
+		expectReadEof();
 
 		kat.receiveKey();
 	}
@@ -148,7 +147,7 @@ public class KeyAgreementTransportTest extends BrambleMockTestCase {
 	public void testReceiveConfirmThrowsExceptionIfAtEndOfStream()
 			throws Exception {
 		setup();
-		expectReadRecord(null);
+		expectReadEof();
 
 		kat.receiveConfirm();
 	}
@@ -209,12 +208,22 @@ public class KeyAgreementTransportTest extends BrambleMockTestCase {
 		assertArrayEquals(expectedPayload, actual.getPayload());
 	}
 
-	private void expectReadRecord(@Nullable Record record) throws Exception {
+	private void expectReadRecord(Record record) throws Exception {
 		context.checking(new Expectations() {{
-			//noinspection unchecked
+			// Test that the `accept` predicate passed to the reader would
-			oneOf(recordReader).readRecord(with(any(Predicate.class)),
+			// accept the expected record
-					with(any(Predicate.class)));
+			oneOf(recordReader).readRecord(with(new PredicateMatcher<>(
+							RecordPredicate.class, rp -> rp.test(record))),
+					with(any(RecordPredicate.class)));
 			will(returnValue(record));
 		}});
 	}
+
+	private void expectReadEof() throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(recordReader).readRecord(with(any(RecordPredicate.class)),
+					with(any(RecordPredicate.class)));
+			will(returnValue(null));
+		}});
+	}
 }

bramble-core/src/test/java/org/briarproject/bramble/record/RecordReaderImplTest.java

@@ -1,9 +1,9 @@
 package org.briarproject.bramble.record;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.record.Record;
 import org.briarproject.bramble.api.record.RecordReader;
+import org.briarproject.bramble.api.record.RecordReader.RecordPredicate;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.util.ByteUtils;
 import org.junit.Test;
@@ -128,12 +128,12 @@ public class RecordReaderImplTest extends BrambleTestCase {
 		RecordReader reader = new RecordReaderImpl(in);
 
 		// Accept records with version 0, type 0 or 1
-		Predicate<Record> accept = r -> {
+		RecordPredicate accept = r -> {
 			byte version = r.getProtocolVersion(), type = r.getRecordType();
 			return version == 0 && (type == 0 || type == 1);
 		};
 		// Ignore records with version 0, any other type
-		Predicate<Record> ignore = r -> {
+		RecordPredicate ignore = r -> {
 			byte version = r.getProtocolVersion(), type = r.getRecordType();
 			return version == 0 && !(type == 0 || type == 1);
 		};
@@ -183,12 +183,12 @@ public class RecordReaderImplTest extends BrambleTestCase {
 		RecordReader reader = new RecordReaderImpl(in);
 
 		// Accept records with version 0, type 0 or 1
-		Predicate<Record> accept = r -> {
+		RecordPredicate accept = r -> {
 			byte version = r.getProtocolVersion(), type = r.getRecordType();
 			return version == 0 && (type == 0 || type == 1);
 		};
 		// Ignore records with version 0, any other type
-		Predicate<Record> ignore = r -> {
+		RecordPredicate ignore = r -> {
 			byte version = r.getProtocolVersion(), type = r.getRecordType();
 			return version == 0 && !(type == 0 || type == 1);
 		};

bramble-core/src/test/java/org/briarproject/bramble/sync/SyncRecordReaderImplTest.java

@@ -1,10 +1,10 @@
 package org.briarproject.bramble.sync;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.UniqueId;
 import org.briarproject.bramble.api.record.Record;
 import org.briarproject.bramble.api.record.RecordReader;
+import org.briarproject.bramble.api.record.RecordReader.RecordPredicate;
 import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
@@ -24,8 +24,6 @@ import org.junit.Test;
 import java.io.ByteArrayOutputStream;
 import java.util.List;
 
-import javax.annotation.Nullable;
-
 import static org.briarproject.bramble.api.record.Record.MAX_RECORD_PAYLOAD_BYTES;
 import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
 import static org.briarproject.bramble.api.sync.RecordTypes.MESSAGE;
@@ -186,7 +184,7 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 	@Test
 	public void testEofReturnsTrueWhenAtEndOfStream() throws Exception {
 		expectReadRecord(createAck());
-		expectReadRecord(null);
+		expectReadEof();
 
 		SyncRecordReader reader =
 				new SyncRecordReaderImpl(messageFactory, recordReader);
@@ -212,15 +210,25 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 		}});
 	}
 
-	private void expectReadRecord(@Nullable Record record) throws Exception {
+	private void expectReadRecord(Record record) throws Exception {
 		context.checking(new Expectations() {{
-			//noinspection unchecked
+			// Test that the `accept` predicate passed to the reader would
-			oneOf(recordReader).readRecord(with(any(Predicate.class)),
+			// accept the expected record
-					with(any(Predicate.class)));
+			oneOf(recordReader).readRecord(with(new PredicateMatcher<>(
+							RecordPredicate.class, rp -> rp.test(record))),
+					with(any(RecordPredicate.class)));
 			will(returnValue(record));
 		}});
 	}
 
+	private void expectReadEof() throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(recordReader).readRecord(with(any(RecordPredicate.class)),
+					with(any(RecordPredicate.class)));
+			will(returnValue(null));
+		}});
+	}
+
 	private Record createMessage(int payloadLength) {
 		return new Record(PROTOCOL_VERSION, MESSAGE, new byte[payloadLength]);
 	}

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

@@ -234,12 +234,12 @@ public abstract class BrambleIntegrationTest<C extends BrambleIntegrationTestCom
 	}
 
 	protected void awaitPendingMessageDelivery(int num)
-			throws TimeoutException {
+			throws TimeoutException, InterruptedException {
 		awaitPendingMessageDelivery(num, TIMEOUT);
 	}
 
 	protected void awaitPendingMessageDelivery(int num, long timeout)
-			throws TimeoutException {
+			throws TimeoutException, InterruptedException {
 		deliveryWaiter.await(timeout, num);
 		assertEquals("Messages delivered", num, deliveryCounter.getAndSet(0));
 

bramble-core/witness.gradle

@@ -6,10 +6,10 @@ dependencyVerification {
         'com.fasterxml.jackson.core:jackson-databind:2.13.4:jackson-databind-2.13.4.jar:c9faff420d9e2c7e1e4711dbeebec2506a32c9942027211c5c293d8d87807eb6',
         '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-compiler:2.43.2:dagger-compiler-2.43.2.jar:298c020ee6ed2f4cc651ebbfdb7f8de329b07c44b618d65be117846a850e2a03',
+        'com.google.dagger:dagger-compiler:2.45:dagger-compiler-2.45.jar:5617dfb994537dba5b41f3744a6dd13ec3cd99789c065e0d5c6fa9f21cf7ca25',
-        'com.google.dagger:dagger-producers:2.43.2:dagger-producers-2.43.2.jar:e7f5d9ffc85d48a49c8e22e02833d418f7ccad5d7512f529964db5127ab915ff',
+        'com.google.dagger:dagger-producers:2.45:dagger-producers-2.45.jar:a05abb4c3ccf6bb0f056bdcb5ef973898ecf172952ab5948a824aeea6c86ecaa',
-        'com.google.dagger:dagger-spi:2.43.2:dagger-spi-2.43.2.jar:3bae8d9dadeaaa5927da6f094389a560c12c05fec3d2711d2fa79292c7a7d7ad',
+        'com.google.dagger:dagger-spi:2.45:dagger-spi-2.45.jar:7cd6f0b09d88e64a9c97bc80e544ab8ac8fdee9301754413585a74cf64222b27',
-        'com.google.dagger:dagger:2.43.2:dagger-2.43.2.jar:c89681f7cbbf8c527bf4ac2748515d617fdb54a1d425c08d914fdc28192b5fe4',
+        'com.google.dagger:dagger:2.45:dagger-2.45.jar:f011cae7d2c0fb7ea17c34e05bc10e768b1081a5892ad019cf1fdb0e125c49c1',
         'com.google.devtools.ksp:symbol-processing-api:1.7.0-1.0.6:symbol-processing-api-1.7.0-1.0.6.jar:adc29417be5ca9ff42118105fea4e36d9ef44987abfc41432309371a60198941',
         'com.google.errorprone:error_prone_annotations:2.7.1:error_prone_annotations-2.7.1.jar:cd5257c08a246cf8628817ae71cb822be192ef91f6881ca4a3fcff4f1de1cff3',
         'com.google.errorprone:javac-shaded:9-dev-r4023-3:javac-shaded-9-dev-r4023-3.jar:65bfccf60986c47fbc17c9ebab0be626afc41741e0a6ec7109e0768817a36f30',
@@ -19,42 +19,44 @@ dependencyVerification {
         'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava:listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:b372a037d4230aa57fbeffdef30fd6123f9c0c2db85d0aced00c91b974f33f99',
         'com.google.j2objc:j2objc-annotations:1.3:j2objc-annotations-1.3.jar:21af30c92267bd6122c0e0b4d20cccb6641a37eaf956c6540ec471d584e64a7b',
         'com.h2database:h2:1.4.192:h2-1.4.192.jar:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
-        'com.squareup.okhttp3:mockwebserver:4.9.3:mockwebserver-4.9.3.jar:9c8c581c29f22f877a35d11380462f75bb24bf1886204fe835ee695594a2784e',
+        'com.squareup.okhttp3:mockwebserver:4.10.0:mockwebserver-4.10.0.jar:af29da234e63159d6e0dea43bf8288eea97d71cdf1651a5ee2d6c0d0d4adbf8f',
-        'com.squareup.okhttp3:okhttp:3.12.13:okhttp-3.12.13.jar:508234e024ef7e270ab1a6d5b356f5b98e786511239ca986d684fd1e2cf7bc82',
+        'com.squareup.okhttp3:okhttp:4.10.0:okhttp-4.10.0.jar:7580f14fa1691206e37081ad3f92063b1603b328da0bb316f2fef02e0562e7ec',
-        'com.squareup.okhttp3:okhttp:4.9.3:okhttp-4.9.3.jar:93ecd6cba19d87dccfe566ec848d91aae799e3cf16c00709358ea69bd9227219',
+        'com.squareup.okio:okio-jvm:3.0.0:okio-jvm-3.0.0.jar:be64a0cc1f28ea9cd5c970dd7e7557af72c808d738c495b397bf897c9921e907',
-        'com.squareup.okio:okio:1.15.0:okio-1.15.0.jar:693fa319a7e8843300602b204023b7674f106ebcb577f2dd5807212b66118bd2',
-        'com.squareup.okio:okio:2.8.0:okio-jvm-2.8.0.jar:4496b06e73982fcdd8a5393f46e5df2ce2fa4465df5895454cac68a32f09bbc8',
         'com.squareup:javapoet:1.13.0:javapoet-1.13.0.jar:4c7517e848a71b36d069d12bb3bf46a70fd4cda3105d822b0ed2e19c00b69291',
+        'com.squareup:kotlinpoet:1.11.0:kotlinpoet-1.11.0.jar:2887ada1ca03dd83baa2758640d87e840d1907564db0ef88d2289c868a980492',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.13.2:junit-4.13.2.jar:8e495b634469d64fb8acfa3495a065cbacc8a0fff55ce1e31007be4c16dc57d3',
         'net.bytebuddy:byte-buddy:1.9.12:byte-buddy-1.9.12.jar:3688c3d434bebc3edc5516296a2ed0f47b65e451071b4afecad84f902f0efc11',
         'net.i2p.crypto:eddsa:0.2.0:eddsa-0.2.0.jar:a7cb1b85c16e2f0730b9204106929a1d9aaae1df728adc7041a8b8b605692140',
         'net.jcip:jcip-annotations:1.0:jcip-annotations-1.0.jar:be5805392060c71474bf6c9a67a099471274d30b83eef84bfc4e0889a4f1dcc0',
-        'net.jodah:concurrentunit:0.4.2:concurrentunit-0.4.2.jar:5583078e1acf91734939e985bc9e7ee947b0e93a8eef679da6bb07bbeb47ced3',
+        'net.jodah:concurrentunit:0.4.6:concurrentunit-0.4.6.jar:760e6d4ab7801484de09da621b61141f3b2c2432949da9eb13f076e5d9a5e0a5',
         'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
         'org.apache-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
         'org.bitlet:weupnp:0.1.4:weupnp-0.1.4.jar:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
         'org.bouncycastle:bcprov-jdk15to18:1.71:bcprov-jdk15to18-1.71.jar:143aaa4a40edd5fc2a18db7900059f6c16f4d931b94b94b20f7e2238e6662886',
         'org.briarproject:jtorctl:0.5:jtorctl-0.5.jar:43f8c7d390169772b9a2c82ab806c8414c136a2a8636c555e22754bb7260793b',
         'org.briarproject:null-safety:0.1:null-safety-0.1.jar:161760de5e838cb982bafa973df820675d4397098e9a91637a36a306d43ba011',
-        'org.briarproject:onionwrapper-core:0.0.1:onionwrapper-core-0.0.1.jar:a1937506b00ee6620e909a500e5d004be81f94a6f7d7c898e1a9e841a8ae8a2a',
+        'org.briarproject:onionwrapper-core:0.0.4:onionwrapper-core-0.0.4.jar:28a01a62e96aa763989a8afc325abd3bee54f8021269f91aa48b247a6e717870',
         'org.briarproject:socks-socket:0.1:socks-socket-0.1.jar:e5898822d10f5390363c5dddb945891648c92cf93ba50709e07f0d173ec0eb4b',
         'org.checkerframework:checker-compat-qual:2.5.5:checker-compat-qual-2.5.5.jar:11d134b245e9cacc474514d2d66b5b8618f8039a1465cdc55bbc0b34e0008b7a',
         'org.checkerframework:checker-qual:3.12.0:checker-qual-3.12.0.jar:ff10785ac2a357ec5de9c293cb982a2cbb605c0309ea4cc1cb9b9bc6dbe7f3cb',
         'org.codehaus.mojo.signature:java16:1.1:java16-1.1.signature:53799223a2c98dba2d0add810bed76315460df285c69e4f397ae6098f87dd619',
-        'org.codehaus.mojo:animal-sniffer-ant-tasks:1.20:animal-sniffer-ant-tasks-1.20.jar:bb7d2498144118311d968bb08ff6fae3fc535fb1cb9cca8b8e9ea65b189422ac',
+        'org.codehaus.mojo:animal-sniffer-ant-tasks:1.22:animal-sniffer-ant-tasks-1.22.jar:3f6afeb3e09301d2d7179ed1db21e3ad8846c1e38415ad832a395138ae3f4218',
-        'org.codehaus.mojo:animal-sniffer:1.20:animal-sniffer-1.20.jar:80c422523c38db91260c6d78e5ee4b012862ab61cc55020c9e243dd7b5c62249',
+        'org.codehaus.mojo:animal-sniffer:1.22:animal-sniffer-1.22.jar:f18c11a25bdd8b520b9c6a28cbb6f33007c812ab0051b6be3f0778e660aa501c',
         'org.hamcrest:hamcrest-core:2.1:hamcrest-core-2.1.jar:e09109e54a289d88506b9bfec987ddd199f4217c9464132668351b9a4f00bee9',
         'org.hamcrest:hamcrest-library:2.1:hamcrest-library-2.1.jar:b7e2b6895b3b679f0e47b6380fda391b225e9b78505db9d8bdde8d3cc8d52a21',
         'org.hamcrest:hamcrest:2.1:hamcrest-2.1.jar:ba93b2e3a562322ba432f0a1b53addcc55cb188253319a020ed77f824e692050',
         'org.hsqldb:hsqldb:2.3.5:hsqldb-2.3.5.jar:6676a6977ac98997a80f827ddbd3fe8ca1e0853dad1492512135fd1a222ccfad',
-        'org.jetbrains.kotlin:kotlin-stdlib-common:1.4.10:kotlin-stdlib-common-1.4.10.jar:4681f2d436a68c7523595d84ed5758e1382f9da0f67c91e6a848690d711274fe',
+        'org.jetbrains.kotlin:kotlin-reflect:1.6.10:kotlin-reflect-1.6.10.jar:3277ac102ae17aad10a55abec75ff5696c8d109790396434b496e75087854203',
+        'org.jetbrains.kotlin:kotlin-stdlib-common:1.6.20:kotlin-stdlib-common-1.6.20.jar:8da40a2520d30dcb1012176fe93d24e82d08a3e346c37e0343b0fb6f64f6be01',
         'org.jetbrains.kotlin:kotlin-stdlib-common:1.7.0:kotlin-stdlib-common-1.7.0.jar:59c6ff64fe9a6604afce03e8aaa75f83586c6030ac71fb0b34ee7cdefed3618f',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.4.10:kotlin-stdlib-jdk7-1.4.10.jar:f9566380c08722c780ce33ceee23e98ddf765ca98fabd3e2fabae7975c8d232b',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.5.31:kotlin-stdlib-jdk7-1.5.31.jar:a25bf47353ce899d843cbddee516d621a73473e7fba97f8d0301e7b4aed7c15f',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.6.10:kotlin-stdlib-jdk7-1.6.10.jar:2aedcdc6b69b33bdf5cc235bcea88e7cf6601146bb6bcdffdb312bbacd7be261',
         'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.0:kotlin-stdlib-jdk7-1.7.0.jar:07e91be9b2ca20672d2bdb7e181b766e73453a2da13492b5ddaee8fa47aea239',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.4.10:kotlin-stdlib-jdk8-1.4.10.jar:39b7a9442d7a3865e0f4a732c56c1d5da0e11ffb3bb82a461d32deb0c0ca7673',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.5.31:kotlin-stdlib-jdk8-1.5.31.jar:b548f7767aacf029d2417e47440742bd6d3ebede19b60386e23554ce5c4c5fdc',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.6.10:kotlin-stdlib-jdk8-1.6.10.jar:1456d82d039ea30d8485b032901f52bbf07e7cdbe8bb1f8708ad32a8574c41ce',
         'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.0:kotlin-stdlib-jdk8-1.7.0.jar:cf058e11db1dfc9944680c8c61b95ac689aaaa8a3eb30bced028100f038f030b',
-        'org.jetbrains.kotlin:kotlin-stdlib:1.4.10:kotlin-stdlib-1.4.10.jar:01ecb09782c042b931c1839acf21a188340b295d05400afd6e3415d4475b8daa',
+        'org.jetbrains.kotlin:kotlin-stdlib:1.6.20:kotlin-stdlib-1.6.20.jar:eeb51c2b67b26233fd81d0bc4f8044ec849718890905763ceffd84a31e2cb799',
         'org.jetbrains.kotlin:kotlin-stdlib:1.7.0:kotlin-stdlib-1.7.0.jar:aa88e9625577957f3249a46cb6e166ee09b369e600f7a11d148d16b0a6d87f05',
         'org.jetbrains.kotlinx:kotlinx-metadata-jvm:0.5.0:kotlinx-metadata-jvm-0.5.0.jar:ca063a96639b08b9eaa0de4d65e899480740a6efbe28ab9a8681a2ced03055a4',
         'org.jetbrains:annotations:13.0:annotations-13.0.jar:ace2a10dc8e2d5fd34925ecac03e4988b2c0f851650c94b8cef49ba1bd111478',
@@ -65,7 +67,7 @@ dependencyVerification {
         'org.jmock:jmock:2.12.0:jmock-2.12.0.jar:266d07314c0cd343c46ff8a55601272de8cf406807caf55e6f313295f83d10be',
         'org.objenesis:objenesis:3.0.1:objenesis-3.0.1.jar:7a8ff780b9ff48415d7c705f60030b0acaa616e7f823c98eede3b63508d4e984',
         'org.ow2.asm:asm:7.1:asm-7.1.jar:4ab2fa2b6d2cc9ccb1eaa05ea329c407b47b13ed2915f62f8c4b8cc96258d4de',
-        'org.ow2.asm:asm:9.1:asm-9.1.jar:cda4de455fab48ff0bcb7c48b4639447d4de859a7afc30a094a986f0936beba2',
+        'org.ow2.asm:asm:9.3:asm-9.3.jar:1263369b59e29c943918de11d6d6152e2ec6085ce63e5710516f8c67d368e4bc',
         'org.whispersystems:curve25519-java:0.5.0:curve25519-java-0.5.0.jar:0aadd43cf01d11e9b58f867b3c4f25c3194e8b0623d1953d32dfbfbee009e38d',
     ]
 }

bramble-java/build.gradle

@@ -11,7 +11,7 @@ dependencies {
 	implementation project(':bramble-core')
 
 	implementation fileTree(dir: 'libs', include: '*.jar')
-	def jna_version = '4.5.2'
+	def jna_version = '5.13.0'
 	implementation "net.java.dev.jna:jna:$jna_version"
 	implementation "net.java.dev.jna:jna-platform:$jna_version"
 	implementation "org.briarproject:onionwrapper-java:$onionwrapper_version"

bramble-java/src/main/java/org/briarproject/bramble/BrambleJavaEagerSingletons.java

@@ -0,0 +1,17 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.network.JavaNetworkModule;
+import org.briarproject.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public interface BrambleJavaEagerSingletons {
+
+	void inject(JavaNetworkModule.EagerSingletons init);
+
+	class Helper {
+
+		public static void injectEagerSingletons(BrambleJavaEagerSingletons c) {
+			c.inject(new JavaNetworkModule.EagerSingletons());
+		}
+	}
+}

bramble-java/src/main/java/org/briarproject/bramble/BrambleJavaModule.java

@@ -3,9 +3,9 @@ package org.briarproject.bramble;
 import org.briarproject.bramble.io.DnsModule;
 import org.briarproject.bramble.mailbox.ModularMailboxModule;
 import org.briarproject.bramble.network.JavaNetworkModule;
+import org.briarproject.bramble.plugin.tor.CircumventionModule;
 import org.briarproject.bramble.socks.SocksModule;
 import org.briarproject.bramble.system.JavaSystemModule;
-import org.briarproject.onionwrapper.CircumventionModule;
 
 import dagger.Module;
 

bramble-java/src/main/java/org/briarproject/bramble/network/JavaNetworkManager.java

@@ -1,33 +1,51 @@
 package org.briarproject.bramble.network;
 
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.lifecycle.Service;
 import org.briarproject.bramble.api.network.NetworkManager;
 import org.briarproject.bramble.api.network.NetworkStatus;
-import org.briarproject.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.network.event.NetworkStatusEvent;
-import org.briarproject.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.system.TaskScheduler;
+import org.briarproject.nullsafety.NotNullByDefault;
 
 import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.net.NetworkInterface;
 import java.net.SocketException;
+import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
 import static java.util.Collections.list;
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.NetworkUtils.getNetworkInterfaces;
 
-@MethodsNotNullByDefault
+@NotNullByDefault
-@ParametersNotNullByDefault
+class JavaNetworkManager implements NetworkManager, Service {
-class JavaNetworkManager implements NetworkManager {
 
 	private static final Logger LOG =
 			getLogger(JavaNetworkManager.class.getName());
 
+	private final TaskScheduler scheduler;
+	private final Executor ioExecutor;
+	private final EventBus eventBus;
+	private final AtomicReference<NetworkStatus> lastStatus =
+			new AtomicReference<>();
+
 	@Inject
-	JavaNetworkManager() {
+	JavaNetworkManager(TaskScheduler scheduler,
+			@IoExecutor Executor ioExecutor,
+			EventBus eventBus) {
+		this.scheduler = scheduler;
+		this.ioExecutor = ioExecutor;
+		this.eventBus = eventBus;
 	}
 
 	@Override
@@ -48,7 +66,29 @@ class JavaNetworkManager implements NetworkManager {
 		} catch (SocketException e) {
 			logException(LOG, WARNING, e);
 		}
+		if (LOG.isLoggable(INFO)) {
+			LOG.info("Connected: " + connected
+					+ ", has IPv4 address: " + hasIpv4
+					+ ", has IPv6 unicast address: " + hasIpv6Unicast);
+		}
 		return new NetworkStatus(connected, false, !hasIpv4 && hasIpv6Unicast);
 	}
 
+	private void broadcastNetworkStatusIfChanged() {
+		NetworkStatus status = getNetworkStatus();
+		NetworkStatus old = lastStatus.getAndSet(status);
+		if (!status.equals(old)) {
+			eventBus.broadcast(new NetworkStatusEvent(status));
+		}
+	}
+
+	@Override
+	public void startService() {
+		scheduler.scheduleWithFixedDelay(this::broadcastNetworkStatusIfChanged,
+				ioExecutor, 0, 10, SECONDS);
+	}
+
+	@Override
+	public void stopService() {
+	}
 }

bramble-java/src/main/java/org/briarproject/bramble/network/JavaNetworkModule.java

@@ -1,7 +1,9 @@
 package org.briarproject.bramble.network;
 
+import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.network.NetworkManager;
 
+import javax.inject.Inject;
 import javax.inject.Singleton;
 
 import dagger.Module;
@@ -10,9 +12,16 @@ import dagger.Provides;
 @Module
 public class JavaNetworkModule {
 
+	public static class EagerSingletons {
+		@Inject
+		NetworkManager networkManager;
+	}
+
 	@Provides
 	@Singleton
-	NetworkManager provideNetworkManager(JavaNetworkManager networkManager) {
+	NetworkManager provideNetworkManager(LifecycleManager lifecycleManager,
+			JavaNetworkManager networkManager) {
+		lifecycleManager.registerService(networkManager);
 		return networkManager;
 	}
 }

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

@@ -0,0 +1,85 @@
+package org.briarproject.bramble.plugin.tor;
+
+import org.briarproject.bramble.api.battery.BatteryManager;
+import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.event.EventBus;
+import org.briarproject.bramble.api.event.EventExecutor;
+import org.briarproject.bramble.api.lifecycle.IoExecutor;
+import org.briarproject.bramble.api.network.NetworkManager;
+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.TorControlPort;
+import org.briarproject.bramble.api.plugin.TorDirectory;
+import org.briarproject.bramble.api.plugin.TorSocksPort;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.system.WakefulIoExecutor;
+import org.briarproject.nullsafety.NotNullByDefault;
+import org.briarproject.onionwrapper.CircumventionProvider;
+import org.briarproject.onionwrapper.LocationUtils;
+import org.briarproject.onionwrapper.MacTorWrapper;
+import org.briarproject.onionwrapper.TorWrapper;
+import org.briarproject.onionwrapper.UnixTorWrapper;
+
+import java.io.File;
+import java.util.concurrent.Executor;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
+import javax.net.SocketFactory;
+
+import static java.util.logging.Level.INFO;
+import static org.briarproject.bramble.util.OsUtils.isMac;
+
+@Immutable
+@NotNullByDefault
+public class MacTorPluginFactory extends TorPluginFactory {
+
+	@Inject
+	MacTorPluginFactory(@IoExecutor Executor ioExecutor,
+			@EventExecutor Executor eventExecutor,
+			@WakefulIoExecutor Executor wakefulIoExecutor,
+			NetworkManager networkManager,
+			LocationUtils locationUtils,
+			EventBus eventBus,
+			SocketFactory torSocketFactory,
+			BackoffFactory backoffFactory,
+			CircumventionProvider circumventionProvider,
+			BatteryManager batteryManager,
+			Clock clock,
+			CryptoComponent crypto,
+			@TorDirectory File torDirectory,
+			@TorSocksPort int torSocksPort,
+			@TorControlPort int torControlPort) {
+		super(ioExecutor, eventExecutor, wakefulIoExecutor, networkManager,
+				locationUtils, eventBus, torSocketFactory, backoffFactory,
+				circumventionProvider, batteryManager, clock, crypto,
+				torDirectory, torSocksPort, torControlPort);
+	}
+
+	@Nullable
+	@Override
+	String getArchitectureForTorBinary() {
+		if (!isMac()) return null;
+		String arch = System.getProperty("os.arch");
+		if (LOG.isLoggable(INFO)) {
+			LOG.info("System's os.arch is " + arch);
+		}
+		if (arch.equals("x86_64")) return "x86_64";
+		else if (arch.equals("aarch64")) return "aarch64";
+		return null;
+	}
+
+	@Override
+	TorPlugin createPluginInstance(Backoff backoff,
+			TorRendezvousCrypto torRendezvousCrypto, PluginCallback callback,
+			String architecture) {
+		TorWrapper tor = new MacTorWrapper(ioExecutor, eventExecutor,
+				architecture, torDirectory, torSocksPort, torControlPort);
+		return new TorPlugin(ioExecutor, wakefulIoExecutor, networkManager,
+				locationUtils, torSocketFactory, circumventionProvider,
+				batteryManager, backoff, torRendezvousCrypto, tor, callback,
+				MAX_LATENCY, MAX_IDLE_TIME, true);
+	}
+}

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

@@ -13,10 +13,10 @@ 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.system.Clock;
-import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.WakefulIoExecutor;
 import org.briarproject.nullsafety.NotNullByDefault;
 import org.briarproject.onionwrapper.CircumventionProvider;
+import org.briarproject.onionwrapper.LocationUtils;
 import org.briarproject.onionwrapper.TorWrapper;
 import org.briarproject.onionwrapper.UnixTorWrapper;
 

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

@@ -13,10 +13,10 @@ 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.system.Clock;
-import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.WakefulIoExecutor;
 import org.briarproject.nullsafety.NotNullByDefault;
 import org.briarproject.onionwrapper.CircumventionProvider;
+import org.briarproject.onionwrapper.LocationUtils;
 import org.briarproject.onionwrapper.TorWrapper;
 import org.briarproject.onionwrapper.WindowsTorWrapper;
 

bramble-java/src/main/java/org/briarproject/bramble/system/DesktopSecureRandomModule.java

@@ -16,7 +16,7 @@ public class DesktopSecureRandomModule {
 	@Provides
 	@Singleton
 	SecureRandomProvider provideSecureRandomProvider() {
-		if (isLinux() || isMac()) return new UnixSecureRandomProvider();
+		if (isLinux()) return new UnixSecureRandomProvider();
 		return () -> null; // Use system default
 	}
 }

bramble-java/src/main/java/org/briarproject/bramble/system/JavaLocationUtils.java

@@ -1,27 +0,0 @@
-package org.briarproject.bramble.system;
-
-import org.briarproject.bramble.api.system.LocationUtils;
-import org.briarproject.nullsafety.NotNullByDefault;
-
-import java.util.Locale;
-import java.util.logging.Logger;
-
-import javax.inject.Inject;
-
-@NotNullByDefault
-class JavaLocationUtils implements LocationUtils {
-
-	private static final Logger LOG =
-			Logger.getLogger(JavaLocationUtils.class.getName());
-
-	@Inject
-	JavaLocationUtils() {
-	}
-
-	@Override
-	public String getCurrentCountry() {
-		LOG.info("Using user-defined locale");
-		return Locale.getDefault().getCountry();
-	}
-
-}

bramble-java/src/main/java/org/briarproject/bramble/system/JavaSystemModule.java

@@ -1,7 +1,8 @@
 package org.briarproject.bramble.system;
 
-import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.api.system.ResourceProvider;
+import org.briarproject.onionwrapper.JavaLocationUtilsFactory;
+import org.briarproject.onionwrapper.LocationUtils;
 
 import javax.inject.Singleton;
 
@@ -13,8 +14,8 @@ public class JavaSystemModule {
 
 	@Provides
 	@Singleton
-	LocationUtils provideLocationUtils(JavaLocationUtils locationUtils) {
+	LocationUtils provideLocationUtils() {
-		return locationUtils;
+		return JavaLocationUtilsFactory.createJavaLocationUtils();
 	}
 
 	@Provides

bramble-java/witness.gradle

@@ -3,10 +3,10 @@ dependencyVerification {
         'cglib:cglib:3.2.8:cglib-3.2.8.jar:3f64de999ecc5595dc84ca8ff0879d8a34c8623f9ef3c517a53ed59023fcb9db',
         '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-compiler:2.43.2:dagger-compiler-2.43.2.jar:298c020ee6ed2f4cc651ebbfdb7f8de329b07c44b618d65be117846a850e2a03',
+        'com.google.dagger:dagger-compiler:2.45:dagger-compiler-2.45.jar:5617dfb994537dba5b41f3744a6dd13ec3cd99789c065e0d5c6fa9f21cf7ca25',
-        'com.google.dagger:dagger-producers:2.43.2:dagger-producers-2.43.2.jar:e7f5d9ffc85d48a49c8e22e02833d418f7ccad5d7512f529964db5127ab915ff',
+        'com.google.dagger:dagger-producers:2.45:dagger-producers-2.45.jar:a05abb4c3ccf6bb0f056bdcb5ef973898ecf172952ab5948a824aeea6c86ecaa',
-        'com.google.dagger:dagger-spi:2.43.2:dagger-spi-2.43.2.jar:3bae8d9dadeaaa5927da6f094389a560c12c05fec3d2711d2fa79292c7a7d7ad',
+        'com.google.dagger:dagger-spi:2.45:dagger-spi-2.45.jar:7cd6f0b09d88e64a9c97bc80e544ab8ac8fdee9301754413585a74cf64222b27',
-        'com.google.dagger:dagger:2.43.2:dagger-2.43.2.jar:c89681f7cbbf8c527bf4ac2748515d617fdb54a1d425c08d914fdc28192b5fe4',
+        'com.google.dagger:dagger:2.45:dagger-2.45.jar:f011cae7d2c0fb7ea17c34e05bc10e768b1081a5892ad019cf1fdb0e125c49c1',
         'com.google.devtools.ksp:symbol-processing-api:1.7.0-1.0.6:symbol-processing-api-1.7.0-1.0.6.jar:adc29417be5ca9ff42118105fea4e36d9ef44987abfc41432309371a60198941',
         'com.google.errorprone:error_prone_annotations:2.7.1:error_prone_annotations-2.7.1.jar:cd5257c08a246cf8628817ae71cb822be192ef91f6881ca4a3fcff4f1de1cff3',
         'com.google.errorprone:javac-shaded:9-dev-r4023-3:javac-shaded-9-dev-r4023-3.jar:65bfccf60986c47fbc17c9ebab0be626afc41741e0a6ec7109e0768817a36f30',
@@ -16,23 +16,25 @@ dependencyVerification {
         'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava:listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:b372a037d4230aa57fbeffdef30fd6123f9c0c2db85d0aced00c91b974f33f99',
         'com.google.j2objc:j2objc-annotations:1.3:j2objc-annotations-1.3.jar:21af30c92267bd6122c0e0b4d20cccb6641a37eaf956c6540ec471d584e64a7b',
         'com.squareup:javapoet:1.13.0:javapoet-1.13.0.jar:4c7517e848a71b36d069d12bb3bf46a70fd4cda3105d822b0ed2e19c00b69291',
+        'com.squareup:kotlinpoet:1.11.0:kotlinpoet-1.11.0.jar:2887ada1ca03dd83baa2758640d87e840d1907564db0ef88d2289c868a980492',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.13.2:junit-4.13.2.jar:8e495b634469d64fb8acfa3495a065cbacc8a0fff55ce1e31007be4c16dc57d3',
         'net.bytebuddy:byte-buddy:1.9.12:byte-buddy-1.9.12.jar:3688c3d434bebc3edc5516296a2ed0f47b65e451071b4afecad84f902f0efc11',
-        'net.java.dev.jna:jna-platform:4.5.2:jna-platform-4.5.2.jar:f1d00c167d8921c6e23c626ef9f1c3ae0be473c95c68ffa012bc7ae55a87e2d6',
+        'net.java.dev.jna:jna-platform:5.13.0:jna-platform-5.13.0.jar:474d7b88f6e97009b6ec1d98c3024dd95c23187c65dabfbc35331bcac3d173dd',
-        'net.java.dev.jna:jna:4.5.2:jna-4.5.2.jar:0c8eb7acf67261656d79005191debaba3b6bf5dd60a43735a245429381dbecff',
+        'net.java.dev.jna:jna:5.13.0:jna-5.13.0.jar:66d4f819a062a51a1d5627bffc23fac55d1677f0e0a1feba144aabdd670a64bb',
         'net.jcip:jcip-annotations:1.0:jcip-annotations-1.0.jar:be5805392060c71474bf6c9a67a099471274d30b83eef84bfc4e0889a4f1dcc0',
         'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
         'org.apache-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
         'org.briarproject:jtorctl:0.5:jtorctl-0.5.jar:43f8c7d390169772b9a2c82ab806c8414c136a2a8636c555e22754bb7260793b',
         'org.briarproject:null-safety:0.1:null-safety-0.1.jar:161760de5e838cb982bafa973df820675d4397098e9a91637a36a306d43ba011',
-        'org.briarproject:onionwrapper-core:0.0.1:onionwrapper-core-0.0.1.jar:a1937506b00ee6620e909a500e5d004be81f94a6f7d7c898e1a9e841a8ae8a2a',
+        'org.briarproject:onionwrapper-core:0.0.4:onionwrapper-core-0.0.4.jar:28a01a62e96aa763989a8afc325abd3bee54f8021269f91aa48b247a6e717870',
-        'org.briarproject:onionwrapper-java:0.0.1:onionwrapper-java-0.0.1.jar:102ccea934d02b13702fd28e890e27e342db8b669a4c84bb54a3783cb8926552',
+        'org.briarproject:onionwrapper-java:0.0.4:onionwrapper-java-0.0.4.jar:7806ef878074498653b557e26eb70e6007df3450d6a910a2e9a322f7eb4df442',
         'org.checkerframework:checker-compat-qual:2.5.5:checker-compat-qual-2.5.5.jar:11d134b245e9cacc474514d2d66b5b8618f8039a1465cdc55bbc0b34e0008b7a',
         'org.checkerframework:checker-qual:3.12.0:checker-qual-3.12.0.jar:ff10785ac2a357ec5de9c293cb982a2cbb605c0309ea4cc1cb9b9bc6dbe7f3cb',
         'org.hamcrest:hamcrest-core:2.1:hamcrest-core-2.1.jar:e09109e54a289d88506b9bfec987ddd199f4217c9464132668351b9a4f00bee9',
         'org.hamcrest:hamcrest-library:2.1:hamcrest-library-2.1.jar:b7e2b6895b3b679f0e47b6380fda391b225e9b78505db9d8bdde8d3cc8d52a21',
         'org.hamcrest:hamcrest:2.1:hamcrest-2.1.jar:ba93b2e3a562322ba432f0a1b53addcc55cb188253319a020ed77f824e692050',
+        'org.jetbrains.kotlin:kotlin-reflect:1.6.10:kotlin-reflect-1.6.10.jar:3277ac102ae17aad10a55abec75ff5696c8d109790396434b496e75087854203',
         'org.jetbrains.kotlin:kotlin-stdlib-common:1.7.0:kotlin-stdlib-common-1.7.0.jar:59c6ff64fe9a6604afce03e8aaa75f83586c6030ac71fb0b34ee7cdefed3618f',
         'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.7.0:kotlin-stdlib-jdk7-1.7.0.jar:07e91be9b2ca20672d2bdb7e181b766e73453a2da13492b5ddaee8fa47aea239',
         'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.7.0:kotlin-stdlib-jdk8-1.7.0.jar:cf058e11db1dfc9944680c8c61b95ac689aaaa8a3eb30bced028100f038f030b',

briar-android/build.gradle

@@ -24,10 +24,10 @@ android {
 	}
 
 	defaultConfig {
-		minSdkVersion 16
+		minSdkVersion 21
-		targetSdkVersion 31
+		targetSdkVersion 33
-		versionCode 10501
+		versionCode 10504
-		versionName "1.5.1"
+		versionName "1.5.4"
 		applicationId "org.briarproject.briar.android"
 		buildConfigField "String", "TorVersion", "\"$tor_version\""
 
@@ -62,7 +62,6 @@ android {
 	productFlavors {
 		screenshot {
 			dimension "version"
-			minSdkVersion 21
 			applicationIdSuffix ".screenshot" // = org.briarproject.briar.android.screenshot.debug
 			proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt', 'proguard-test.txt'
 		}
@@ -90,6 +89,7 @@ android {
 
 	lintOptions {
 		warning 'MissingTranslation'
+		warning 'MissingDefaultResource'
 		warning 'ImpliedQuantity'
 		warning 'ExtraTranslation'
 		// FIXME
@@ -108,24 +108,30 @@ dependencies {
 	implementation project(':bramble-android')
 	implementation project(':briar-core')
 
-	implementation 'androidx.fragment:fragment:1.3.4'
+	implementation 'androidx.fragment:fragment:1.5.5'
-	implementation 'androidx.preference:preference:1.1.1'
+	implementation 'androidx.preference:preference:1.2.0'
-	implementation 'androidx.exifinterface:exifinterface:1.3.3'
+	implementation 'androidx.exifinterface:exifinterface:1.3.6'
-	implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
+	implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.5.1'
-	implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
+	implementation 'androidx.lifecycle:lifecycle-livedata:2.5.1'
-	implementation 'com.google.android.material:material:1.3.0'
+
+	implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
+	// check https://github.com/material-components/material-components-android/issues/3191
+	// before upgrading material library
+	implementation 'com.google.android.material:material:1.7.0'
 	implementation 'androidx.recyclerview:recyclerview-selection:1.1.0'
 
+	// force kotlin standard lib to latest version to prevent jetifier issues
+	implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlin_version"
 	implementation "com.squareup.okhttp3:okhttp:$okhttp_version"
 	implementation "org.jsoup:jsoup:$jsoup_version"
 	implementation 'info.guardianproject.panic:panic:1.0'
 	implementation 'de.hdodenhof:circleimageview:3.1.0'
 	implementation 'com.google.zxing:core:3.3.3'  // newer version need minSdk 24
-	implementation 'uk.co.samuelwall:material-tap-target-prompt:3.3.0'
+	implementation 'uk.co.samuelwall:material-tap-target-prompt:3.3.2'
-	implementation 'com.vanniktech:emoji-google:0.7.0' // newer versions need minSdk 21
+	implementation 'com.vanniktech:emoji-google:0.9.0' // newer versions are more work to adapt
 	implementation 'com.github.kobakei:MaterialFabSpeedDial:1.2.1'
 	implementation 'com.github.chrisbanes:PhotoView:2.3.0'
-	def glideVersion = '4.12.0'
+	def glideVersion = '4.14.2'
 	implementation("com.github.bumptech.glide:glide:$glideVersion") {
 		exclude group: 'com.android.support'
 		exclude module: 'disklrucache' // when there's no disk cache, we can't accidentally use it
@@ -142,12 +148,12 @@ dependencies {
 
 	def espressoVersion = '3.3.0'
 	testImplementation 'androidx.test:runner:1.4.0'
-	testImplementation 'androidx.test.ext:junit:1.1.3'
+	testImplementation 'androidx.test.ext:junit:1.1.5'
 	testImplementation 'androidx.fragment:fragment-testing:1.4.0'
 	testImplementation "androidx.arch.core:core-testing:2.1.0"
-	testImplementation "androidx.test.espresso:espresso-core:$espressoVersion"
+	testImplementation "androidx.test.espresso:espresso-core:3.5.0"
-	testImplementation 'org.robolectric:robolectric:4.4'
+	testImplementation 'org.robolectric:robolectric:4.8.2' // newer versions have SecureRandom issue
-	testImplementation 'org.mockito:mockito-core:3.9.0'
+	testImplementation 'org.mockito:mockito-core:5.1.1'
 	testImplementation "junit:junit:$junit_version"
 	testImplementation "org.jmock:jmock:$jmock_version"
 	testImplementation "org.jmock:jmock-junit4:$jmock_version"

briar-android/src/main/AndroidManifest.xml

@@ -19,6 +19,10 @@
 	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 	<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
 	<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
+	<uses-permission
+		android:name="android.permission.NEARBY_WIFI_DEVICES"
+		android:usesPermissionFlags="neverForLocation"
+		tools:targetApi="31" />
 	<uses-permission android:name="android.permission.CAMERA" />
 	<uses-permission android:name="android.permission.INTERNET" />
 	<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
@@ -30,8 +34,10 @@
 		android:name="android.permission.WRITE_EXTERNAL_STORAGE"
 		android:maxSdkVersion="18"
 		tools:ignore="ScopedStorage" />
+	<uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
 
-	<uses-permission-sdk-23 android:name="android.permission.ACCESS_FINE_LOCATION" />
+	<uses-permission-sdk-23 android:name="android.permission.ACCESS_FINE_LOCATION"
+		android:maxSdkVersion="32" />
 	<uses-permission-sdk-23 android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />
 	<uses-permission-sdk-23 android:name="android.permission.USE_BIOMETRIC" />
 	<uses-permission-sdk-23 android:name="android.permission.FOREGROUND_SERVICE" />
@@ -99,11 +105,6 @@
 			android:exported="false"
 			android:label="@string/app_name" />
 
-		<activity
-			android:name="org.briarproject.briar.android.splash.ExpiredOldAndroidActivity"
-			android:exported="false"
-			android:label="@string/app_name" />
-
 		<activity
 			android:name="org.briarproject.briar.android.login.StartupActivity"
 			android:exported="false"

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

@@ -27,7 +27,6 @@ import org.briarproject.bramble.api.plugin.PluginManager;
 import org.briarproject.bramble.api.settings.SettingsManager;
 import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.mailbox.ModularMailboxModule;
 import org.briarproject.bramble.plugin.file.RemovableDriveModule;
 import org.briarproject.bramble.system.ClockModule;
@@ -84,6 +83,7 @@ import org.briarproject.briar.api.privategroup.invitation.GroupInvitationFactory
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager;
 import org.briarproject.briar.api.test.TestDataCreator;
 import org.briarproject.onionwrapper.CircumventionProvider;
+import org.briarproject.onionwrapper.LocationUtils;
 
 import java.util.concurrent.Executor;
 

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

@@ -294,10 +294,8 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		b.setOngoing(true);
 		Intent i = new Intent(appContext, SplashScreenActivity.class);
 		b.setContentIntent(getActivity(appContext, 0, i, getImmutableFlags(0)));
-		if (SDK_INT >= 21) {
+		b.setCategory(CATEGORY_SERVICE);
-			b.setCategory(CATEGORY_SERVICE);
+		b.setVisibility(VISIBILITY_SECRET);
-			b.setVisibility(VISIBILITY_SECRET);
-		}
 		b.setPriority(PRIORITY_MIN);
 		return b.build();
 	}
@@ -773,8 +771,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		i.setAction(ACTION_STOP_HOTSPOT);
 		PendingIntent actionIntent =
 				getActivity(appContext, 0, i, getImmutableFlags(0));
-		int icon = SDK_INT >= 21 ? R.drawable.ic_portable_wifi_off : 0;
+		b.addAction(R.drawable.ic_portable_wifi_off, actionTitle, actionIntent);
-		b.addAction(icon, actionTitle, actionIntent);
 		notificationManager.notify(HOTSPOT_NOTIFICATION_ID, b.build());
 	}
 

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

@@ -212,7 +212,7 @@ public class AppModule {
 			public Collection<SimplexPluginFactory> getSimplexFactories() {
 				List<SimplexPluginFactory> simplex = new ArrayList<>();
 				simplex.add(mailbox);
-				if (SDK_INT >= 19) simplex.add(drive);
+				simplex.add(drive);
 				return simplex;
 			}
 

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

@@ -7,17 +7,26 @@ import android.content.IntentFilter;
 import android.os.PowerManager;
 
 import org.briarproject.bramble.api.lifecycle.Service;
-import org.briarproject.bramble.api.lifecycle.ServiceException;
 import org.briarproject.briar.api.android.DozeWatchdog;
 
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Logger;
+
+import androidx.annotation.RequiresApi;
 
 import static android.content.Context.POWER_SERVICE;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
+import static android.os.PowerManager.ACTION_DEVICE_LIGHT_IDLE_MODE_CHANGED;
+import static android.os.PowerManager.ACTION_LOW_POWER_STANDBY_ENABLED_CHANGED;
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
 
 class DozeWatchdogImpl implements DozeWatchdog, Service {
 
+	private static final Logger LOG =
+			getLogger(DozeWatchdogImpl.class.getName());
+
 	private final Context appContext;
 	private final AtomicBoolean dozed = new AtomicBoolean(false);
 	private final BroadcastReceiver receiver = new DozeBroadcastReceiver();
@@ -32,14 +41,18 @@ class DozeWatchdogImpl implements DozeWatchdog, Service {
 	}
 
 	@Override
-	public void startService() throws ServiceException {
+	public void startService() {
 		if (SDK_INT < 23) return;
 		IntentFilter filter = new IntentFilter(ACTION_DEVICE_IDLE_MODE_CHANGED);
+		if (SDK_INT >= 33) {
+			filter.addAction(ACTION_DEVICE_LIGHT_IDLE_MODE_CHANGED);
+			filter.addAction(ACTION_LOW_POWER_STANDBY_ENABLED_CHANGED);
+		}
 		appContext.registerReceiver(receiver, filter);
 	}
 
 	@Override
-	public void stopService() throws ServiceException {
+	public void stopService() {
 		if (SDK_INT < 23) return;
 		appContext.unregisterReceiver(receiver);
 	}
@@ -49,9 +62,33 @@ class DozeWatchdogImpl implements DozeWatchdog, Service {
 		@Override
 		public void onReceive(Context context, Intent intent) {
 			if (SDK_INT < 23) return;
+			String action = intent.getAction();
 			PowerManager pm =
 					(PowerManager) appContext.getSystemService(POWER_SERVICE);
-			if (pm.isDeviceIdleMode()) dozed.set(true);
+			if (ACTION_DEVICE_IDLE_MODE_CHANGED.equals(action)) {
+				if (pm.isDeviceIdleMode()) dozed.set(true);
+			} else if (SDK_INT >= 33) {
+				onReceive33(action, pm);
+			}
+		}
+
+		@RequiresApi(33)
+		private void onReceive33(String action, PowerManager pm) {
+			if (ACTION_LOW_POWER_STANDBY_ENABLED_CHANGED.equals(action)) {
+				if (pm.isLowPowerStandbyEnabled()) {
+					if (LOG.isLoggable(WARNING)) {
+						LOG.warning("System is in low power standby mode");
+					}
+					dozed.set(true);
+				}
+			} else if (ACTION_DEVICE_LIGHT_IDLE_MODE_CHANGED.equals(action)) {
+				if (pm.isDeviceLightIdleMode()) {
+					if (LOG.isLoggable(WARNING)) {
+						LOG.warning("System is in light idle mode");
+					}
+					dozed.set(true);
+				}
+			}
 		}
 	}
 }

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

@@ -56,16 +56,8 @@ public class Localizer {
 	// Get Locale from BCP-47 tag
 	@Nullable
 	public static Locale getLocaleFromTag(String tag) {
-		if (tag.equals("default"))
+		if (tag.equals("default")) return null;
-			return null;
+		return Locale.forLanguageTag(tag);
-		if (SDK_INT >= 21) {
-			return Locale.forLanguageTag(tag);
-		}
-		if (tag.contains("-")) {
-			String[] langArray = tag.split("-");
-			return new Locale(langArray[0], langArray[1]);
-		} else
-			return new Locale(tag);
 	}
 
 	/*
@@ -94,12 +86,8 @@ public class Localizer {
 		if (locale.equals(currentLocale))
 			return context;
 		Locale.setDefault(locale);
-		if (SDK_INT >= 17) {
+		conf.setLocale(locale);
-			conf.setLocale(locale);
+		context = context.createConfigurationContext(conf);
-			context = context.createConfigurationContext(conf);
-		} else
-			conf.locale = locale;
-		//noinspection deprecation
 		res.updateConfiguration(conf, res.getDisplayMetrics());
 		return context;
 	}

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

@@ -2,8 +2,8 @@ package org.briarproject.briar.android;
 
 import org.briarproject.briar.BuildConfig;
 
-import static android.os.Build.VERSION.SDK_INT;
 import static java.util.concurrent.TimeUnit.DAYS;
+import static org.briarproject.briar.BuildConfig.BuildTimestamp;
 
 public interface TestingConstants {
 
@@ -20,15 +20,9 @@ public interface TestingConstants {
 	 */
 	boolean PREVENT_SCREENSHOTS = !IS_DEBUG_BUILD;
 
-	boolean IS_OLD_ANDROID = SDK_INT <= 19;
-	long OLD_ANDROID_WARN_DATE = 1659225600_000L;   // 2022-07-31
-	long OLD_ANDROID_EXPIRY_DATE = 1675123200_000L; // 2023-01-31
-
 	/**
-	 * Debug builds expire after 90 days. Release builds running on Android 4
+	 * Debug builds expire after 90 days.
-	 * expire at a set date, otherwise they expire after 292 million years.
 	 */
 	long EXPIRY_DATE = IS_DEBUG_BUILD ?
-			BuildConfig.BuildTimestamp + DAYS.toMillis(90)
+			BuildTimestamp + DAYS.toMillis(90) : Long.MAX_VALUE;
-			: (IS_OLD_ANDROID ? OLD_ANDROID_EXPIRY_DATE : Long.MAX_VALUE);
 }

briar-android/src/main/java/org/briarproject/briar/android/account/DozeFragment.java

@@ -1,6 +1,7 @@
 package org.briarproject.briar.android.account;
 
 import android.annotation.SuppressLint;
+import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.os.Bundle;
 import android.view.LayoutInflater;
@@ -8,6 +9,7 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Button;
 import android.widget.ProgressBar;
+import android.widget.Toast;
 
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.account.PowerView.OnCheckedChangedListener;
@@ -18,6 +20,7 @@ import androidx.annotation.Nullable;
 
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
+import static android.widget.Toast.LENGTH_LONG;
 import static org.briarproject.android.dontkillmelib.DozeUtils.getDozeWhitelistingIntent;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_DOZE_WHITELISTING;
 import static org.briarproject.briar.android.util.UiUtils.showOnboardingDialog;
@@ -113,7 +116,12 @@ public class DozeFragment extends SetupFragment
 	private void askForDozeWhitelisting() {
 		if (getContext() == null) return;
 		Intent i = getDozeWhitelistingIntent(getContext());
-		startActivityForResult(i, REQUEST_DOZE_WHITELISTING);
+		try {
+			startActivityForResult(i, REQUEST_DOZE_WHITELISTING);
+		} catch (ActivityNotFoundException e) {
+			Toast.makeText(requireContext(),
+					R.string.error_start_activity, LENGTH_LONG).show();
+		}
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/account/HuaweiProtectedAppsView.java

@@ -14,6 +14,7 @@ import androidx.annotation.UiThread;
 
 import static org.briarproject.android.dontkillmelib.HuaweiUtils.getHuaweiProtectedAppsIntent;
 import static org.briarproject.android.dontkillmelib.HuaweiUtils.protectedAppsNeedsToBeShown;
+import static org.briarproject.briar.android.util.UiUtils.tryToStartActivity;
 
 @UiThread
 @NotNullByDefault
@@ -49,7 +50,7 @@ class HuaweiProtectedAppsView extends PowerView {
 
 	@Override
 	protected void onButtonClick() {
-		getContext().startActivity(getHuaweiProtectedAppsIntent());
+		tryToStartActivity(getContext(), getHuaweiProtectedAppsIntent());
 		setChecked(true);
 	}
 }

briar-android/src/main/java/org/briarproject/briar/android/account/SetPasswordFragment.java

@@ -19,10 +19,17 @@ import org.briarproject.nullsafety.ParametersNotNullByDefault;
 
 import javax.annotation.Nullable;
 
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts.RequestPermission;
+
+import static android.Manifest.permission.POST_NOTIFICATIONS;
 import static android.content.Context.INPUT_METHOD_SERVICE;
+import static android.content.pm.PackageManager.PERMISSION_GRANTED;
+import static android.os.Build.VERSION.SDK_INT;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;
+import static androidx.core.content.ContextCompat.checkSelfPermission;
 import static org.briarproject.bramble.api.crypto.PasswordStrengthEstimator.QUITE_WEAK;
 import static org.briarproject.briar.android.util.UiUtils.setError;
 
@@ -38,6 +45,10 @@ public class SetPasswordFragment extends SetupFragment {
 	private StrengthMeter strengthMeter;
 	private Button nextButton;
 
+	private final ActivityResultLauncher<String> requestPermissionLauncher =
+			registerForActivityResult(new RequestPermission(), isGranted ->
+					setPassword());
+
 	public static SetPasswordFragment newInstance() {
 		return new SetPasswordFragment();
 	}
@@ -121,6 +132,18 @@ public class SetPasswordFragment extends SetupFragment {
 		IBinder token = passwordEntry.getWindowToken();
 		Object o = requireContext().getSystemService(INPUT_METHOD_SERVICE);
 		((InputMethodManager) o).hideSoftInputFromWindow(token, 0);
+		if (SDK_INT >= 33 &&
+				checkSelfPermission(requireContext(), POST_NOTIFICATIONS) !=
+						PERMISSION_GRANTED) {
+			// this calls setPassword() when it returns
+			requestPermissionLauncher.launch(POST_NOTIFICATIONS);
+		} else {
+			setPassword();
+		}
+	}
+
+	private void setPassword() {
 		viewModel.setPassword(passwordEntry.getText().toString());
 	}
+
 }

briar-android/src/main/java/org/briarproject/briar/android/account/SetupActivity.java

@@ -36,7 +36,7 @@ public class SetupActivity extends BaseActivity
 
 	@Inject
 	ViewModelProvider.Factory viewModelFactory;
-	SetupViewModel viewModel;
+	private SetupViewModel viewModel;
 
 	@Override
 	public void injectActivity(ActivityComponent component) {
@@ -71,16 +71,16 @@ public class SetupActivity extends BaseActivity
 		}
 	}
 
-	void showPasswordFragment() {
+	private void showPasswordFragment() {
 		showNextFragment(SetPasswordFragment.newInstance());
 	}
 
 	@TargetApi(23)
-	void showDozeFragment() {
+	private void showDozeFragment() {
 		showNextFragment(DozeFragment.newInstance());
 	}
 
-	void showApp() {
+	private void showApp() {
 		Intent i = new Intent(this, ENTRY_ACTIVITY);
 		i.setFlags(FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_TASK_ON_HOME |
 				FLAG_ACTIVITY_CLEAR_TASK | FLAG_ACTIVITY_CLEAR_TOP);

briar-android/src/main/java/org/briarproject/briar/android/account/UnlockActivity.java

@@ -1,6 +1,7 @@
 package org.briarproject.briar.android.account;
 
 import android.app.KeyguardManager;
+import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.hardware.biometrics.BiometricPrompt;
 import android.hardware.biometrics.BiometricPrompt.AuthenticationCallback;
@@ -28,11 +29,11 @@ import static android.hardware.biometrics.BiometricPrompt.BIOMETRIC_ERROR_CANCEL
 import static android.hardware.biometrics.BiometricPrompt.BIOMETRIC_ERROR_USER_CANCELED;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.view.View.INVISIBLE;
+import static android.widget.Toast.LENGTH_LONG;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_KEYGUARD_UNLOCK;
 import static org.briarproject.briar.android.util.UiUtils.hasKeyguardLock;
 import static org.briarproject.briar.android.util.UiUtils.hasUsableFingerprint;
 
-@RequiresApi(21)
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class UnlockActivity extends BaseActivity {
@@ -192,7 +193,12 @@ public class UnlockActivity extends BaseActivity {
 			unlock();
 		} else {
 			keyguardShown = true;
-			startActivityForResult(intent, REQUEST_KEYGUARD_UNLOCK);
+			try {
+				startActivityForResult(intent, REQUEST_KEYGUARD_UNLOCK);
+			} catch (ActivityNotFoundException e) {
+				Toast.makeText(this, R.string.error_start_activity, LENGTH_LONG)
+						.show();
+			}
 			overridePendingTransition(0, 0);
 		}
 	}

briar-android/src/main/java/org/briarproject/briar/android/account/XiaomiLockAppsView.java

@@ -1,5 +1,6 @@
 package org.briarproject.briar.android.account;
 
+import android.content.ActivityNotFoundException;
 import android.content.Context;
 import android.util.AttributeSet;
 import android.widget.Toast;
@@ -60,12 +61,12 @@ class XiaomiLockAppsView extends PowerView {
 			getContext().startActivity(getXiaomiLockAppsIntent());
 			setChecked(true);
 			return;
-		} catch (SecurityException e) {
+		} catch (SecurityException | ActivityNotFoundException e) {
 			logException(LOG, WARNING, e);
+			Toast.makeText(getContext(),
+					R.string.dnkm_xiaomi_lock_apps_error_toast,
+					LENGTH_LONG).show();
 		}
-		Toast.makeText(getContext(),
-				R.string.dnkm_xiaomi_lock_apps_error_toast,
-				LENGTH_LONG).show();
 		// Let the user continue with setup
 		setChecked(true);
 	}

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

@@ -81,7 +81,6 @@ import org.briarproject.briar.android.sharing.ShareBlogFragment;
 import org.briarproject.briar.android.sharing.ShareForumActivity;
 import org.briarproject.briar.android.sharing.ShareForumFragment;
 import org.briarproject.briar.android.sharing.SharingModule;
-import org.briarproject.briar.android.splash.ExpiredOldAndroidActivity;
 import org.briarproject.briar.android.splash.SplashScreenActivity;
 import org.briarproject.briar.android.test.TestDataActivity;
 
@@ -184,8 +183,6 @@ public interface ActivityComponent {
 
 	void inject(RemovableDriveActivity activity);
 
-	void inject(ExpiredOldAndroidActivity activity);
-
 	// Fragments
 
 	void inject(SetupFragment fragment);

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

@@ -1,9 +1,11 @@
 package org.briarproject.briar.android.activity;
 
+import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.transition.Transition;
 import android.view.Window;
 import android.widget.CheckBox;
+import android.widget.Toast;
 
 import org.briarproject.android.dontkillmelib.wakelock.AndroidWakeLockManager;
 import org.briarproject.bramble.api.system.Wakeful;
@@ -24,7 +26,6 @@ import java.util.logging.Logger;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import androidx.annotation.RequiresApi;
 import androidx.annotation.StringRes;
 import androidx.appcompat.app.ActionBar;
 import androidx.appcompat.app.AlertDialog;
@@ -35,9 +36,12 @@ import static android.content.Intent.FLAG_ACTIVITY_EXCLUDE_FROM_RECENTS;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.content.Intent.FLAG_ACTIVITY_NO_ANIMATION;
 import static android.os.Build.VERSION.SDK_INT;
+import static android.widget.Toast.LENGTH_LONG;
 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.android.dontkillmelib.DozeUtils.getDozeWhitelistingIntent;
+import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_DOZE_WHITELISTING;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PASSWORD;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_UNLOCK;
@@ -105,7 +109,7 @@ public abstract class BriarActivity extends BaseActivity {
 			LOG.info("Not signed in, launching StartupActivity");
 			Intent i = new Intent(this, StartupActivity.class);
 			startActivityForResult(i, REQUEST_PASSWORD);
-		} else if (SDK_INT >= 21 && lockManager.isLocked() && !isFinishing()) {
+		} else if (lockManager.isLocked() && !isFinishing()) {
 			// Also check that the activity isn't finishing already.
 			// This is possible if we finished in onActivityResult().
 			// Launching another UnlockActivity would cause a loop.
@@ -135,8 +139,7 @@ public abstract class BriarActivity extends BaseActivity {
 	 * @param exitTransition used to move views out when starting a <b>new</b> activity.
 	 * @param returnTransition used when window is closing, because the activity is finishing.
 	 */
-	@RequiresApi(api = 21)
+	protected void setSceneTransitionAnimation(
-	public void setSceneTransitionAnimation(
 			@Nullable Transition enterTransition,
 			@Nullable Transition exitTransition,
 			@Nullable Transition returnTransition) {
@@ -181,7 +184,13 @@ public abstract class BriarActivity extends BaseActivity {
 		b.setPositiveButton(R.string.fix,
 				(dialog, which) -> {
 					Intent i = getDozeWhitelistingIntent(BriarActivity.this);
-					startActivityForResult(i, REQUEST_DOZE_WHITELISTING);
+					try {
+						startActivityForResult(i, REQUEST_DOZE_WHITELISTING);
+					} catch (ActivityNotFoundException e) {
+						logException(LOG, WARNING, e);
+						Toast.makeText(this, R.string.error_start_activity,
+								LENGTH_LONG).show();
+					}
 					dialog.dismiss();
 				});
 		b.setNegativeButton(R.string.cancel,
@@ -232,8 +241,7 @@ public abstract class BriarActivity extends BaseActivity {
 
 	@Wakeful
 	private void finishAndExit() {
-		if (SDK_INT >= 21) finishAndRemoveTask();
+		finishAndRemoveTask();
-		else supportFinishAfterTransition();
 		LOG.info("Exiting");
 		BriarApplication app = (BriarApplication) getApplication();
 		if (!app.isInstrumentationTest()) System.exit(0);

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

@@ -21,7 +21,6 @@ import androidx.annotation.UiThread;
 import androidx.core.view.ViewCompat;
 import androidx.recyclerview.widget.RecyclerView;
 
-import static android.os.Build.VERSION.SDK_INT;
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
@@ -134,12 +133,6 @@ class BlogPostViewHolder extends RecyclerView.ViewHolder {
 		} else {
 			reblogger.setVisibility(GONE);
 		}
-
-		// Apply Android 4 padding fix after setting up author/reblogger views
-		if (SDK_INT < 21) {
-			reblogger.setPadding(padding, padding, padding, padding);
-			author.setPadding(padding, padding, padding, padding);
-		}
 	}
 
 	private void onBindComment(BlogCommentItem item, boolean authorClickable) {

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

@@ -27,11 +27,9 @@ import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import androidx.activity.result.ActivityResultLauncher;
-import androidx.annotation.RequiresApi;
 import androidx.fragment.app.Fragment;
 import androidx.lifecycle.ViewModelProvider;
 
-import static android.os.Build.VERSION.SDK_INT;
 import static android.view.View.GONE;
 import static android.view.View.VISIBLE;
 import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;
@@ -52,7 +50,6 @@ public class RssFeedImportFragment extends BaseFragment {
 	private Button importButton;
 	private ProgressBar progressBar;
 
-	@RequiresApi(19)
 	private final ActivityResultLauncher<String[]> docLauncher =
 			registerForActivityResult(new OpenDocumentAdvanced(),
 					this::onFileChosen);
@@ -74,7 +71,7 @@ public class RssFeedImportFragment extends BaseFragment {
 			@Nullable ViewGroup container,
 			@Nullable Bundle savedInstanceState) {
 		requireActivity().setTitle(getString(R.string.blogs_rss_feeds_import));
-		if (SDK_INT >= 19) setHasOptionsMenu(true);
+		setHasOptionsMenu(true);
 		View v = inflater.inflate(R.layout.fragment_rss_feed_import,
 				container, false);
 
@@ -117,15 +114,13 @@ public class RssFeedImportFragment extends BaseFragment {
 
 	@Override
 	public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
-		if (SDK_INT >= 19) {
+		inflater.inflate(R.menu.rss_feed_import_actions, menu);
-			inflater.inflate(R.menu.rss_feed_import_actions, menu);
-		}
 		super.onCreateOptionsMenu(menu, inflater);
 	}
 
 	@Override
 	public boolean onOptionsItemSelected(MenuItem item) {
-		if (item.getItemId() == R.id.action_import_file && SDK_INT >= 19) {
+		if (item.getItemId() == R.id.action_import_file) {
 			launchActivityToOpenFile(requireContext(), docLauncher,
 					contentLauncher, "*/*");
 			return true;

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

@@ -55,7 +55,6 @@ import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener
 import org.briarproject.briar.android.introduction.IntroductionActivity;
 import org.briarproject.briar.android.privategroup.conversation.GroupActivity;
 import org.briarproject.briar.android.removabledrive.RemovableDriveActivity;
-import org.briarproject.briar.android.util.ActivityLaunchers.GetImageAdvanced;
 import org.briarproject.briar.android.util.ActivityLaunchers.GetMultipleImagesAdvanced;
 import org.briarproject.briar.android.util.ActivityLaunchers.OpenMultipleImageDocumentsAdvanced;
 import org.briarproject.briar.android.util.BriarSnackbarBuilder;
@@ -122,13 +121,11 @@ import androidx.vectordrawable.graphics.drawable.VectorDrawableCompat;
 import de.hdodenhof.circleimageview.CircleImageView;
 import uk.co.samuelwall.materialtaptargetprompt.MaterialTapTargetPrompt;
 
-import static android.os.Build.VERSION.SDK_INT;
 import static android.view.Gravity.RIGHT;
 import static android.widget.Toast.LENGTH_SHORT;
 import static androidx.core.app.ActivityOptionsCompat.makeSceneTransitionAnimation;
 import static androidx.lifecycle.Lifecycle.State.STARTED;
 import static androidx.recyclerview.widget.SortedList.INVALID_POSITION;
-import static java.util.Collections.singletonList;
 import static java.util.Collections.sort;
 import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.INFO;
@@ -200,18 +197,13 @@ public class ConversationActivity extends BriarActivity
 		requireNonNull(name);
 		loadMessages();
 	};
-	@Nullable
+
-	private final ActivityResultLauncher<String[]> docLauncher = SDK_INT >= 19 ?
+	private final ActivityResultLauncher<String[]> docLauncher =
 			registerForActivityResult(new OpenMultipleImageDocumentsAdvanced(),
-					this::onImagesChosen) :
+					this::onImagesChosen);
-			null;
 	private final ActivityResultLauncher<String> contentLauncher =
-			SDK_INT >= 18 ?
+			registerForActivityResult(new GetMultipleImagesAdvanced(),
-					registerForActivityResult(new GetMultipleImagesAdvanced(),
+					this::onImagesChosen);
-							this::onImagesChosen) :
-					registerForActivityResult(new GetImageAdvanced(), uri -> {
-						if (uri != null) onImagesChosen(singletonList(uri));
-					});
 
 	private AttachmentRetriever attachmentRetriever;
 	private ConversationViewModel viewModel;
@@ -242,13 +234,11 @@ public class ConversationActivity extends BriarActivity
 
 	@Override
 	public void onCreate(@Nullable Bundle state) {
-		if (SDK_INT >= 21) {
+		// Spurious lint warning - using END causes a crash
-			// Spurious lint warning - using END causes a crash
+		@SuppressLint("RtlHardcoded")
-			@SuppressLint("RtlHardcoded")
+		Transition slide = new Slide(RIGHT);
-			Transition slide = new Slide(RIGHT);
+		slide.setDuration(TRANSITION_DURATION_MS);
-			slide.setDuration(TRANSITION_DURATION_MS);
+		setSceneTransitionAnimation(slide, null, slide);
-			setSceneTransitionAnimation(slide, null, slide);
-		}
 		super.onCreate(state);
 
 		Intent i = getIntent();
@@ -389,10 +379,6 @@ public class ConversationActivity extends BriarActivity
 						this::showIntroductionOnboarding);
 			}
 		});
-		// Transfer Data feature only supported on API 19+
-		if (SDK_INT >= 19) {
-			menu.findItem(R.id.action_transfer_data).setVisible(true);
-		}
 		// enable alias and bluetooth action once available
 		observeOnce(viewModel.getContactItem(), this, contact -> {
 			menu.findItem(R.id.action_set_alias).setEnabled(true);
@@ -434,11 +420,9 @@ public class ConversationActivity extends BriarActivity
 			startActivity(intent);
 			return true;
 		} else if (itemId == R.id.action_transfer_data) {
-			if (SDK_INT >= 19) {
+			Intent intent = new Intent(this, RemovableDriveActivity.class);
-				Intent intent = new Intent(this, RemovableDriveActivity.class);
+			intent.putExtra(CONTACT_ID, contactId.getInt());
-				intent.putExtra(CONTACT_ID, contactId.getInt());
+			startActivity(intent);
-				startActivity(intent);
-			}
 			return true;
 		} else if (itemId == R.id.action_delete_all_messages) {
 			askToDeleteAllMessages();
@@ -955,14 +939,10 @@ public class ConversationActivity extends BriarActivity
 
 	private void showImageOnboarding(Boolean show) {
 		if (!show) return;
-		if (SDK_INT >= 21) {
+		// show onboarding only after the enter transition has ended
-			// show onboarding only after the enter transition has ended
+		// otherwise the tap target animation won't play
-			// otherwise the tap target animation won't play
+		textInputView.postDelayed(this::showImageOnboarding,
-			textInputView.postDelayed(this::showImageOnboarding,
+				TRANSITION_DURATION_MS + ONBOARDING_DELAY_MS);
-					TRANSITION_DURATION_MS + ONBOARDING_DELAY_MS);
-		} else {
-			showImageOnboarding();
-		}
 	}
 
 	private void showImageOnboarding() {
@@ -973,14 +953,10 @@ public class ConversationActivity extends BriarActivity
 
 	private void showIntroductionOnboarding(@Nullable Boolean show) {
 		if (show == null || !show) return;
-		if (SDK_INT >= 21) {
+		// show onboarding only after the enter transition has ended
-			// show onboarding only after the enter transition has ended
+		// otherwise the tap target animation won't play
-			// otherwise the tap target animation won't play
+		textInputView.postDelayed(this::showIntroductionOnboarding,
-			textInputView.postDelayed(this::showIntroductionOnboarding,
+				TRANSITION_DURATION_MS + ONBOARDING_DELAY_MS);
-					TRANSITION_DURATION_MS + ONBOARDING_DELAY_MS);
-		} else {
-			showIntroductionOnboarding();
-		}
 	}
 
 	private void showIntroductionOnboarding() {

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

@@ -26,6 +26,7 @@ import org.briarproject.briar.android.util.BriarSnackbarBuilder;
 import org.briarproject.briar.android.view.PullDownLayout;
 import org.briarproject.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.nullsafety.ParametersNotNullByDefault;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.List;
 
@@ -41,13 +42,11 @@ import androidx.viewpager2.adapter.FragmentStateAdapter;
 import androidx.viewpager2.widget.ViewPager2;
 
 import static android.graphics.Color.TRANSPARENT;
-import static android.os.Build.VERSION.SDK_INT;
 import static android.view.View.GONE;
 import static android.view.View.SYSTEM_UI_FLAG_FULLSCREEN;
 import static android.view.View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
 import static android.view.View.SYSTEM_UI_FLAG_LAYOUT_STABLE;
 import static android.view.View.VISIBLE;
-import static android.view.WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS;
 import static com.google.android.material.snackbar.Snackbar.LENGTH_LONG;
 import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.util.UiUtils.formatDateAbsolute;
@@ -77,11 +76,9 @@ public class ImageActivity extends BriarActivity
 	private List<AttachmentItem> attachments;
 	private MessageId conversationMessageId;
 
-	@Nullable
+	private final ActivityResultLauncher<String> launcher =
-	private final ActivityResultLauncher<String> launcher = SDK_INT >= 19 ?
 			registerForActivityResult(new CreateDocumentAdvanced(),
-					this::onImageUriSelected) :
+					this::onImageUriSelected);
-			null;
 
 	@Override
 	public void injectActivity(ActivityComponent component) {
@@ -97,10 +94,8 @@ public class ImageActivity extends BriarActivity
 		// Transitions
 		if (state == null) supportPostponeEnterTransition();
 		Window window = getWindow();
-		if (SDK_INT >= 21) {
+		Transition transition = new Fade();
-			Transition transition = new Fade();
+		setSceneTransitionAnimation(transition, null, transition);
-			setSceneTransitionAnimation(transition, null, transition);
-		}
 
 		// Intent Extras
 		Intent i = getIntent();
@@ -124,12 +119,7 @@ public class ImageActivity extends BriarActivity
 		layout.getViewTreeObserver().addOnGlobalLayoutListener(this);
 
 		// Status Bar
-		if (SDK_INT >= 21) {
+		window.setStatusBarColor(TRANSPARENT);
-			window.setStatusBarColor(TRANSPARENT);
-		} else if (SDK_INT >= 19) {
-			// we can't make the status bar transparent, but translucent
-			window.addFlags(FLAG_TRANSLUCENT_STATUS);
-		}
 
 		// Toolbar
 		appBarLayout = findViewById(R.id.appBarLayout);
@@ -257,16 +247,12 @@ public class ImageActivity extends BriarActivity
 
 	private void showSaveImageDialog() {
 		OnClickListener okListener = (dialog, which) -> {
-			if (SDK_INT >= 19) {
+			String name = viewModel.getFileName() + "." +
-				String name = viewModel.getFileName() + "." +
+					getVisibleAttachment().getExtension();
-						getVisibleAttachment().getExtension();
+			try {
-				try {
+				launcher.launch(name);
-					requireNonNull(launcher).launch(name);
+			} catch (ActivityNotFoundException e) {
-				} catch (ActivityNotFoundException e) {
+				viewModel.onSaveImageError();
-					viewModel.onSaveImageError();
-				}
-			} else {
-				viewModel.saveImage(getVisibleAttachment());
 			}
 		};
 		Builder builder = new Builder(this, R.style.BriarDialogTheme);
@@ -295,7 +281,7 @@ public class ImageActivity extends BriarActivity
 				.show();
 	}
 
-	AttachmentItem getVisibleAttachment() {
+	private AttachmentItem getVisibleAttachment() {
 		return attachments.get(viewPager.getCurrentItem());
 	}
 
@@ -307,6 +293,7 @@ public class ImageActivity extends BriarActivity
 			super(ImageActivity.this);
 		}
 
+		@NotNull
 		@Override
 		public Fragment createFragment(int position) {
 			Fragment f = ImageFragment.newInstance(

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

@@ -31,7 +31,6 @@ import androidx.fragment.app.Fragment;
 import androidx.lifecycle.LifecycleOwner;
 import androidx.lifecycle.ViewModelProvider;
 
-import static android.os.Build.VERSION.SDK_INT;
 import static android.widget.ImageView.ScaleType.FIT_START;
 import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
 import static org.briarproject.briar.android.attachment.AttachmentItem.State.AVAILABLE;
@@ -150,7 +149,7 @@ public class ImageFragment extends Fragment
 	public boolean onResourceReady(Drawable resource, Object model,
 			Target<Drawable> target, DataSource dataSource,
 			boolean isFirstResource) {
-		if (SDK_INT >= 21 && !(resource instanceof Animatable)) {
+		if (!(resource instanceof Animatable)) {
 			// set transition name only when not animatable,
 			// because the animation won't start otherwise
 			photoView.setTransitionName(

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

@@ -18,7 +18,6 @@ import androidx.annotation.DrawableRes;
 import androidx.recyclerview.widget.RecyclerView.ViewHolder;
 import androidx.recyclerview.widget.StaggeredGridLayoutManager.LayoutParams;
 
-import static android.os.Build.VERSION.SDK_INT;
 import static android.widget.ImageView.ScaleType.CENTER_CROP;
 import static android.widget.ImageView.ScaleType.FIT_CENTER;
 import static com.bumptech.glide.load.engine.DiskCacheStrategy.NONE;
@@ -58,10 +57,8 @@ class ImageViewHolder extends ViewHolder {
 			loadImage(attachment, r);
 			imageView.setScaleType(CENTER_CROP);
 		}
-		if (SDK_INT >= 21) {
+		imageView.setTransitionName(
-			imageView.setTransitionName(
+				attachment.getTransitionName(conversationItemId));
-					attachment.getTransitionName(conversationItemId));
-		}
 	}
 
 	private void setImageViewDimensions(AttachmentItem a, boolean single,

briar-android/src/main/java/org/briarproject/briar/android/forum/ForumPostItem.java

@@ -1,8 +1,5 @@
 package org.briarproject.briar.android.forum;
 
-import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.briar.api.identity.AuthorInfo;
-import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.android.threaded.ThreadItem;
 import org.briarproject.briar.api.forum.ForumPostHeader;
 

briar-android/src/main/java/org/briarproject/briar/android/fragment/ScreenFilterDialogFragment.java

@@ -19,6 +19,7 @@ import org.briarproject.briar.api.android.ScreenFilterMonitor;
 import org.briarproject.briar.api.android.ScreenFilterMonitor.AppDetails;
 import org.briarproject.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.nullsafety.ParametersNotNullByDefault;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -32,6 +33,7 @@ import androidx.fragment.app.DialogFragment;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.provider.Settings.ACTION_MANAGE_OVERLAY_PERMISSION;
 import static android.view.View.GONE;
+import static org.briarproject.briar.android.util.UiUtils.tryToStartActivity;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -68,6 +70,7 @@ public class ScreenFilterDialogFragment extends DialogFragment {
 		((BaseActivity) requireActivity()).getActivityComponent().inject(this);
 	}
 
+	@NotNull
 	@Override
 	public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {
 		Activity activity = getActivity();
@@ -98,7 +101,7 @@ public class ScreenFilterDialogFragment extends DialogFragment {
 			builder.setNeutralButton(R.string.screen_filter_review_apps,
 					(dialog, which) -> {
 						Intent i = new Intent(ACTION_MANAGE_OVERLAY_PERMISSION);
-						startActivity(i);
+						tryToStartActivity(requireActivity(), i);
 					});
 		}
 		builder.setPositiveButton(R.string.continue_button, (dialog, which) -> {

briar-android/src/main/java/org/briarproject/briar/android/hotspot/AbstractConditionManager.java

@@ -1,21 +1,27 @@
 package org.briarproject.briar.android.hotspot;
 
+import android.content.ActivityNotFoundException;
 import android.content.Context;
+import android.content.Intent;
 import android.net.wifi.WifiManager;
+import android.widget.Toast;
 
 import org.briarproject.briar.R;
 
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts;
 import androidx.annotation.StringRes;
 import androidx.appcompat.app.AlertDialog;
 import androidx.core.util.Consumer;
 import androidx.fragment.app.FragmentActivity;
 
 import static android.content.Context.WIFI_SERVICE;
+import static android.widget.Toast.LENGTH_LONG;
 
 /**
  * Abstract base class for the ConditionManagers that ensure that the conditions
  * to open a hotspot are fulfilled. There are different extensions of this for
- * API levels lower than 29 and 29+.
+ * API levels lower than 29, 29+ and 33+.
  */
 abstract class AbstractConditionManager {
 
@@ -28,6 +34,7 @@ abstract class AbstractConditionManager {
 	final Consumer<Boolean> permissionUpdateCallback;
 	protected FragmentActivity ctx;
 	WifiManager wifiManager;
+	private ActivityResultLauncher<Intent> wifiRequest;
 
 	AbstractConditionManager(Consumer<Boolean> permissionUpdateCallback) {
 		this.permissionUpdateCallback = permissionUpdateCallback;
@@ -38,8 +45,12 @@ abstract class AbstractConditionManager {
 	 */
 	void init(FragmentActivity ctx) {
 		this.ctx = ctx;
-		this.wifiManager = (WifiManager) ctx.getApplicationContext()
+		wifiManager = (WifiManager) ctx.getApplicationContext()
 				.getSystemService(WIFI_SERVICE);
+		wifiRequest = ctx.registerForActivityResult(
+				new ActivityResultContracts.StartActivityForResult(),
+				result -> permissionUpdateCallback
+						.accept(wifiManager.isWifiEnabled()));
 	}
 
 	/**
@@ -57,6 +68,8 @@ abstract class AbstractConditionManager {
 	 */
 	abstract boolean checkAndRequestConditions();
 
+	abstract String getWifiSettingsAction();
+
 	void showRationale(Context ctx, @StringRes int title,
 			@StringRes int body, Runnable onContinueClicked,
 			Runnable onDismiss) {
@@ -69,4 +82,13 @@ abstract class AbstractConditionManager {
 		builder.show();
 	}
 
+	void requestEnableWiFi() {
+		try {
+			wifiRequest.launch(new Intent(getWifiSettingsAction()));
+		} catch (ActivityNotFoundException e) {
+			Toast.makeText(ctx, R.string.error_start_activity, LENGTH_LONG)
+					.show();
+		}
+	}
+
 }

briar-android/src/main/java/org/briarproject/briar/android/hotspot/ConditionManager.java

@@ -1,15 +1,12 @@
 package org.briarproject.briar.android.hotspot;
 
-import android.content.Intent;
 import android.provider.Settings;
 
 import org.briarproject.briar.R;
+import org.briarproject.nullsafety.NotNullByDefault;
 
 import java.util.logging.Logger;
 
-import androidx.activity.result.ActivityResultCaller;
-import androidx.activity.result.ActivityResultLauncher;
-import androidx.activity.result.contract.ActivityResultContracts.StartActivityForResult;
 import androidx.core.util.Consumer;
 
 import static java.util.logging.Level.INFO;
@@ -22,20 +19,14 @@ import static java.util.logging.Logger.getLogger;
  * As soon as {@link #checkAndRequestConditions()} returns true,
  * all conditions are fulfilled.
  */
+@NotNullByDefault
 class ConditionManager extends AbstractConditionManager {
 
 	private static final Logger LOG =
 			getLogger(ConditionManager.class.getName());
 
-	private final ActivityResultLauncher<Intent> wifiRequest;
+	ConditionManager(Consumer<Boolean> permissionUpdateCallback) {
-
+		super( permissionUpdateCallback);
-	ConditionManager(ActivityResultCaller arc,
-			Consumer<Boolean> permissionUpdateCallback) {
-		super(permissionUpdateCallback);
-		wifiRequest = arc.registerForActivityResult(
-				new StartActivityForResult(),
-				result -> permissionUpdateCallback
-						.accept(wifiManager.isWifiEnabled()));
 	}
 
 	@Override
@@ -76,8 +67,9 @@ class ConditionManager extends AbstractConditionManager {
 		return false;
 	}
 
-	private void requestEnableWiFi() {
+	@Override
-		wifiRequest.launch(new Intent(Settings.ACTION_WIFI_SETTINGS));
+	String getWifiSettingsAction() {
+		return Settings.ACTION_WIFI_SETTINGS;
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/hotspot/ConditionManager29.java

@@ -1,18 +1,17 @@
 package org.briarproject.briar.android.hotspot;
 
-import android.content.Intent;
 import android.provider.Settings;
 
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.util.Permission;
 import org.briarproject.briar.android.util.PermissionUtils;
+import org.briarproject.nullsafety.NotNullByDefault;
 
 import java.util.logging.Logger;
 
 import androidx.activity.result.ActivityResultCaller;
 import androidx.activity.result.ActivityResultLauncher;
 import androidx.activity.result.contract.ActivityResultContracts.RequestPermission;
-import androidx.activity.result.contract.ActivityResultContracts.StartActivityForResult;
 import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 import androidx.core.util.Consumer;
@@ -28,12 +27,13 @@ import static org.briarproject.briar.android.util.PermissionUtils.showLocationDi
 
 /**
  * This class ensures that the conditions to open a hotspot are fulfilled on
- * API levels >= 29.
+ * API levels >= 29 and < 33.
  * <p>
  * As soon as {@link #checkAndRequestConditions()} returns true,
  * all conditions are fulfilled.
  */
 @RequiresApi(29)
+@NotNullByDefault
 class ConditionManager29 extends AbstractConditionManager {
 
 	private static final Logger LOG =
@@ -42,7 +42,6 @@ class ConditionManager29 extends AbstractConditionManager {
 	private Permission locationPermission = Permission.UNKNOWN;
 
 	private final ActivityResultLauncher<String> locationRequest;
-	private final ActivityResultLauncher<Intent> wifiRequest;
 
 	ConditionManager29(ActivityResultCaller arc,
 			Consumer<Boolean> permissionUpdateCallback) {
@@ -53,11 +52,6 @@ class ConditionManager29 extends AbstractConditionManager {
 					onRequestPermissionResult(granted);
 					permissionUpdateCallback.accept(TRUE.equals(granted));
 				});
-		wifiRequest = arc.registerForActivityResult(
-				new StartActivityForResult(),
-				result -> permissionUpdateCallback
-						.accept(wifiManager.isWifiEnabled())
-		);
 	}
 
 	@Override
@@ -131,6 +125,11 @@ class ConditionManager29 extends AbstractConditionManager {
 		return false;
 	}
 
+	@Override
+	String getWifiSettingsAction() {
+		return Settings.Panel.ACTION_WIFI;
+	}
+
 	private void onRequestPermissionResult(@Nullable Boolean granted) {
 		if (granted != null && granted) {
 			locationPermission = Permission.GRANTED;
@@ -146,8 +145,4 @@ class ConditionManager29 extends AbstractConditionManager {
 		locationRequest.launch(ACCESS_FINE_LOCATION);
 	}
 
-	private void requestEnableWiFi() {
-		wifiRequest.launch(new Intent(Settings.Panel.ACTION_WIFI));
-	}
-
 }

briar-android/src/main/java/org/briarproject/briar/android/hotspot/ConditionManager33.java

@@ -0,0 +1,134 @@
+package org.briarproject.briar.android.hotspot;
+
+import android.provider.Settings;
+
+import org.briarproject.briar.R;
+import org.briarproject.briar.android.util.Permission;
+import org.briarproject.briar.android.util.PermissionUtils;
+import org.briarproject.nullsafety.NotNullByDefault;
+
+import java.util.logging.Logger;
+
+import androidx.activity.result.ActivityResultCaller;
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts.RequestPermission;
+import androidx.annotation.Nullable;
+import androidx.annotation.RequiresApi;
+import androidx.core.util.Consumer;
+
+import static android.Manifest.permission.NEARBY_WIFI_DEVICES;
+import static androidx.core.app.ActivityCompat.shouldShowRequestPermissionRationale;
+import static java.lang.Boolean.TRUE;
+import static java.util.logging.Level.INFO;
+import static java.util.logging.Logger.getLogger;
+
+/**
+ * This class ensures that the conditions to open a hotspot are fulfilled on
+ * API levels >= 33.
+ * <p>
+ * As soon as {@link #checkAndRequestConditions()} returns true,
+ * all conditions are fulfilled.
+ */
+@RequiresApi(33)
+@NotNullByDefault
+class ConditionManager33 extends AbstractConditionManager {
+
+	private static final Logger LOG =
+			getLogger(ConditionManager33.class.getName());
+
+	private Permission nearbyWifiPermission = Permission.UNKNOWN;
+
+	private final ActivityResultLauncher<String> nearbyWifiRequest;
+
+	ConditionManager33(ActivityResultCaller arc,
+			Consumer<Boolean> permissionUpdateCallback) {
+		super(permissionUpdateCallback);
+		// permissionUpdateCallback receives false if permissions were denied
+		nearbyWifiRequest = arc.registerForActivityResult(
+				new RequestPermission(), granted -> {
+					onRequestPermissionResult(granted);
+					permissionUpdateCallback.accept(TRUE.equals(granted));
+				});
+	}
+
+	@Override
+	void onStart() {
+		nearbyWifiPermission = Permission.UNKNOWN;
+	}
+
+	private boolean areEssentialPermissionsGranted() {
+		boolean isWifiEnabled = wifiManager.isWifiEnabled();
+		if (LOG.isLoggable(INFO)) {
+			LOG.info(String.format("areEssentialPermissionsGranted(): " +
+							"nearbyWifiPermission? %s, " +
+							"wifiManager.isWifiEnabled()? %b",
+					nearbyWifiPermission, isWifiEnabled));
+		}
+		return nearbyWifiPermission == Permission.GRANTED && isWifiEnabled;
+	}
+
+	@Override
+	boolean checkAndRequestConditions() {
+		if (areEssentialPermissionsGranted()) return true;
+
+		if (nearbyWifiPermission == Permission.UNKNOWN) {
+			requestPermissions();
+			return false;
+		}
+
+		// If the location permission has been permanently denied, ask the
+		// user to change the setting
+		if (nearbyWifiPermission == Permission.PERMANENTLY_DENIED) {
+			PermissionUtils.showDenialDialog(ctx,
+					R.string.permission_nearby_devices_title,
+					R.string.permission_hotspot_nearby_wifi_denied_body,
+					() -> permissionUpdateCallback.accept(false));
+			return false;
+		}
+
+		// Should we show the rationale for location permission?
+		if (nearbyWifiPermission == Permission.SHOW_RATIONALE) {
+			showRationale(ctx,
+					R.string.permission_location_title,
+					R.string.permission_hotspot_nearby_wifi_request_body,
+					this::requestPermissions,
+					() -> permissionUpdateCallback.accept(false));
+			return false;
+		}
+
+		// If Wifi is not enabled, we show the rationale for enabling Wifi?
+		if (!wifiManager.isWifiEnabled()) {
+			showRationale(ctx, R.string.wifi_settings_title,
+					R.string.wifi_settings_request_enable_body,
+					this::requestEnableWiFi,
+					() -> permissionUpdateCallback.accept(false));
+			return false;
+		}
+
+		// we shouldn't usually reach this point, but if we do, return false
+		// anyway to force a recheck. Maybe some condition changed in the
+		// meantime.
+		return false;
+	}
+
+	@Override
+	String getWifiSettingsAction() {
+		return Settings.Panel.ACTION_WIFI;
+	}
+
+	private void onRequestPermissionResult(@Nullable Boolean granted) {
+		if (granted != null && granted) {
+			nearbyWifiPermission = Permission.GRANTED;
+		} else if (shouldShowRequestPermissionRationale(ctx,
+				NEARBY_WIFI_DEVICES)) {
+			nearbyWifiPermission = Permission.SHOW_RATIONALE;
+		} else {
+			nearbyWifiPermission = Permission.PERMANENTLY_DENIED;
+		}
+	}
+
+	private void requestPermissions() {
+		nearbyWifiRequest.launch(NEARBY_WIFI_DEVICES);
+	}
+
+}

briar-android/src/main/java/org/briarproject/briar/android/hotspot/FallbackFragment.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.hotspot;
 
 import android.content.Context;
 import android.content.Intent;
-import android.content.pm.ResolveInfo;
 import android.net.Uri;
 import android.os.Bundle;
 import android.view.LayoutInflater;
@@ -17,8 +16,6 @@ import org.briarproject.briar.android.util.ActivityLaunchers.CreateDocumentAdvan
 import org.briarproject.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.nullsafety.ParametersNotNullByDefault;
 
-import java.util.List;
-
 import javax.inject.Inject;
 
 import androidx.activity.result.ActivityResultLauncher;
@@ -29,14 +26,12 @@ import androidx.lifecycle.ViewModelProvider;
 import static android.content.Intent.ACTION_SEND;
 import static android.content.Intent.EXTRA_STREAM;
 import static android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION;
-import static android.content.pm.PackageManager.MATCH_DEFAULT_ONLY;
-import static android.os.Build.VERSION.SDK_INT;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static androidx.transition.TransitionManager.beginDelayedTransition;
 import static org.briarproject.briar.android.AppModule.getAndroidComponent;
 import static org.briarproject.briar.android.hotspot.HotspotViewModel.getApkFileName;
-import static org.briarproject.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.briar.android.util.UiUtils.tryToStartActivity;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -48,11 +43,9 @@ public class FallbackFragment extends BaseFragment {
 	ViewModelProvider.Factory viewModelFactory;
 
 	private HotspotViewModel viewModel;
-	@Nullable
+	private final ActivityResultLauncher<String> launcher =
-	private final ActivityResultLauncher<String> launcher = SDK_INT >= 19 ?
 			registerForActivityResult(new CreateDocumentAdvanced(),
-					this::onDocumentCreated) :
+					this::onDocumentCreated);
-			null;
 	private Button fallbackButton;
 	private ProgressBar progressBar;
 
@@ -89,12 +82,7 @@ public class FallbackFragment extends BaseFragment {
 			beginDelayedTransition((ViewGroup) v);
 			fallbackButton.setVisibility(INVISIBLE);
 			progressBar.setVisibility(VISIBLE);
-
+			launcher.launch(getApkFileName());
-			if (SDK_INT >= 19) {
-				requireNonNull(launcher).launch(getApkFileName());
-			} else {
-				viewModel.exportApk();
-			}
 		});
 		viewModel.getSavedApkToUri().observeEvent(this, this::shareUri);
 	}
@@ -110,24 +98,12 @@ public class FallbackFragment extends BaseFragment {
 		progressBar.setVisibility(INVISIBLE);
 	}
 
-	void shareUri(Uri uri) {
+	private void shareUri(Uri uri) {
 		Intent i = new Intent(ACTION_SEND);
 		i.putExtra(EXTRA_STREAM, uri);
 		i.setType("*/*"); // gives us all sharing options
 		i.addFlags(FLAG_GRANT_READ_URI_PERMISSION);
-		Context ctx = requireContext();
+		tryToStartActivity(requireActivity(), Intent.createChooser(i, null));
-		if (SDK_INT <= 19) {
-			// Workaround for Android bug:
-			// ctx.grantUriPermission also needed for Android 4
-			List<ResolveInfo> resInfoList = ctx.getPackageManager()
-					.queryIntentActivities(i, MATCH_DEFAULT_ONLY);
-			for (ResolveInfo resolveInfo : resInfoList) {
-				String packageName = resolveInfo.activityInfo.packageName;
-				ctx.grantUriPermission(packageName, uri,
-						FLAG_GRANT_READ_URI_PERMISSION);
-			}
-		}
-		startActivity(Intent.createChooser(i, null));
 	}
 
 }

briar-android/src/main/java/org/briarproject/briar/android/hotspot/HotspotIntroFragment.java

@@ -49,8 +49,10 @@ public class HotspotIntroFragment extends Fragment {
 	private TextView progressTextView;
 
 	private final AbstractConditionManager conditionManager = SDK_INT < 29 ?
-			new ConditionManager(this, this::onPermissionUpdate) :
+			new ConditionManager(this::onPermissionUpdate) :
-			new ConditionManager29(this, this::onPermissionUpdate);
+			SDK_INT >= 33 ?
+					new ConditionManager33(this, this::onPermissionUpdate) :
+					new ConditionManager29(this, this::onPermissionUpdate);
 
 	@Override
 	public void onAttach(Context context) {
@@ -87,7 +89,6 @@ public class HotspotIntroFragment extends Fragment {
 	}
 
 	private void onButtonClick(View view) {
-		startButton.setEnabled(false);
 		startHotspotIfConditionsFulfilled();
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/hotspot/HotspotViewModel.java

@@ -25,7 +25,6 @@ import org.briarproject.nullsafety.NotNullByDefault;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.concurrent.Executor;
@@ -38,9 +37,6 @@ import androidx.annotation.UiThread;
 import androidx.lifecycle.LiveData;
 import androidx.lifecycle.MutableLiveData;
 
-import static android.os.Build.VERSION.SDK_INT;
-import static android.os.Environment.DIRECTORY_DOWNLOADS;
-import static android.os.Environment.getExternalStoragePublicDirectory;
 import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
@@ -168,7 +164,6 @@ class HotspotViewModel extends DbViewModel
 	}
 
 	void exportApk(Uri uri) {
-		if (SDK_INT < 19) throw new IllegalStateException();
 		try {
 			OutputStream out = getApplication().getContentResolver()
 					.openOutputStream(uri, "wt");
@@ -178,20 +173,6 @@ class HotspotViewModel extends DbViewModel
 		}
 	}
 
-	void exportApk() {
-		if (SDK_INT >= 19) throw new IllegalStateException();
-		File path = getExternalStoragePublicDirectory(DIRECTORY_DOWNLOADS);
-		//noinspection ResultOfMethodCallIgnored
-		path.mkdirs();
-		File file = new File(path, getApkFileName());
-		try {
-			OutputStream out = new FileOutputStream(file);
-			writeApk(out, Uri.fromFile(file));
-		} catch (FileNotFoundException e) {
-			handleException(e);
-		}
-	}
-
 	static String getApkFileName() {
 		return "briar" + (DEBUG ? "-debug-" : "-") + VERSION_NAME + ".apk";
 	}

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

@@ -22,13 +22,19 @@ import org.briarproject.nullsafety.ParametersNotNullByDefault;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import androidx.activity.result.ActivityResultLauncher;
+import androidx.activity.result.contract.ActivityResultContracts.RequestPermission;
 import androidx.appcompat.app.AlertDialog;
 import androidx.lifecycle.LifecycleOwner;
 import androidx.lifecycle.ViewModelProvider;
 
+import static android.Manifest.permission.POST_NOTIFICATIONS;
+import static android.content.pm.PackageManager.PERMISSION_GRANTED;
+import static android.os.Build.VERSION.SDK_INT;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
 import static android.view.inputmethod.EditorInfo.IME_ACTION_DONE;
+import static androidx.core.content.ContextCompat.checkSelfPermission;
 import static org.briarproject.bramble.api.crypto.DecryptionResult.KEY_STRENGTHENER_ERROR;
 import static org.briarproject.bramble.api.crypto.DecryptionResult.SUCCESS;
 import static org.briarproject.briar.android.login.LoginUtils.createKeyStrengthenerErrorDialog;
@@ -52,6 +58,10 @@ public class PasswordFragment extends BaseFragment implements TextWatcher {
 	private TextInputLayout input;
 	private TextInputEditText password;
 
+	private final ActivityResultLauncher<String> requestPermissionLauncher =
+			registerForActivityResult(new RequestPermission(), isGranted ->
+					validatePassword());
+
 	@Override
 	public void injectFragment(ActivityComponent component) {
 		component.inject(this);
@@ -109,6 +119,17 @@ public class PasswordFragment extends BaseFragment implements TextWatcher {
 		hideSoftKeyboard(password);
 		signInButton.setVisibility(INVISIBLE);
 		progress.setVisibility(VISIBLE);
+		if (SDK_INT >= 33 &&
+				checkSelfPermission(requireContext(), POST_NOTIFICATIONS) !=
+						PERMISSION_GRANTED) {
+			// this calls validatePassword() when it returns
+			requestPermissionLauncher.launch(POST_NOTIFICATIONS);
+		} else {
+			validatePassword();
+		}
+	}
+
+	private void validatePassword() {
 		viewModel.validatePassword(password.getText().toString());
 	}
 

briar-android/src/main/java/org/briarproject/briar/android/logout/ExitActivity.java

@@ -5,8 +5,6 @@ import android.os.Bundle;
 
 import java.util.logging.Logger;
 
-import static android.os.Build.VERSION.SDK_INT;
-
 public class ExitActivity extends Activity {
 
 	private static final Logger LOG =
@@ -15,8 +13,7 @@ public class ExitActivity extends Activity {
 	@Override
 	public void onCreate(Bundle state) {
 		super.onCreate(state);
-		if (SDK_INT >= 21) finishAndRemoveTask();
+		finishAndRemoveTask();
-		else finish();
 		LOG.info("Exiting");
 		System.exit(0);
 	}

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

@@ -75,15 +75,12 @@ import static org.briarproject.bramble.api.plugin.Plugin.State.ENABLING;
 import static org.briarproject.bramble.api.plugin.Plugin.State.STARTING_STOPPING;
 import static org.briarproject.briar.android.BriarService.EXTRA_STARTUP_FAILED;
 import static org.briarproject.briar.android.BriarService.EXTRA_START_RESULT;
-import static org.briarproject.briar.android.TestingConstants.EXPIRY_DATE;
 import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PASSWORD;
 import static org.briarproject.briar.android.navdrawer.IntentRouter.handleExternalIntent;
-import static org.briarproject.briar.android.util.UiUtils.formatDateFull;
 import static org.briarproject.briar.android.util.UiUtils.getDaysUntilExpiry;
 import static org.briarproject.briar.android.util.UiUtils.observeOnce;
 import static org.briarproject.briar.android.util.UiUtils.resolveColorAttribute;
-import static org.briarproject.briar.android.util.UiUtils.shouldWarnOldAndroidExpiry;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -140,11 +137,9 @@ public class NavDrawerActivity extends BriarActivity implements
 		setContentView(R.layout.activity_nav_drawer);
 
 		BriarApplication app = (BriarApplication) getApplication();
-		if (!app.isInstrumentationTest()) {
+		if (IS_DEBUG_BUILD && !app.isInstrumentationTest()) {
-			if (IS_DEBUG_BUILD || shouldWarnOldAndroidExpiry()) {
+			navDrawerViewModel.showExpiryWarning()
-				navDrawerViewModel.showExpiryWarning()
+					.observe(this, this::showExpiryWarning);
-						.observe(this, this::showExpiryWarning);
-			}
 		}
 		navDrawerViewModel.shouldAskForDozeWhitelisting().observe(this, ask -> {
 			if (ask) showDozeDialog(R.string.dnkm_doze_intro);
@@ -212,7 +207,7 @@ public class NavDrawerActivity extends BriarActivity implements
 	public void onStart() {
 		super.onStart();
 		lockManager.checkIfLockable();
-		if (IS_DEBUG_BUILD || shouldWarnOldAndroidExpiry()) {
+		if (IS_DEBUG_BUILD) {
 			navDrawerViewModel.checkExpiryWarning();
 		}
 	}
@@ -384,23 +379,14 @@ public class NavDrawerActivity extends BriarActivity implements
 			return;
 		}
 
-		String text;
-		if (IS_DEBUG_BUILD) {
-			text = getResources().getQuantityString(
-					R.plurals.expiry_warning, (int) daysUntilExpiry,
-					(int) daysUntilExpiry);
-		} else {
-			text = getResources().getQuantityString(
-					R.plurals.old_android_expiry_warning, (int) daysUntilExpiry,
-					formatDateFull(this, EXPIRY_DATE),
-					(int) daysUntilExpiry);
-		}
-
 		ViewGroup expiryWarning = findViewById(R.id.expiryWarning);
 		if (show) {
 			// show expiry warning text
 			TextView expiryWarningText =
 					expiryWarning.findViewById(R.id.expiryWarningText);
+			String text = getResources().getQuantityString(
+					R.plurals.expiry_warning, (int) daysUntilExpiry,
+					(int) daysUntilExpiry);
 			expiryWarningText.setText(text);
 			// make close button functional
 			ImageView expiryWarningClose =
@@ -432,7 +418,7 @@ public class NavDrawerActivity extends BriarActivity implements
 			}
 
 			@Override
-			public View getView(int position, View convertView,
+			public View getView(int position, @Nullable View convertView,
 					ViewGroup parent) {
 				View view;
 				if (convertView != null) {

briar-android/src/main/java/org/briarproject/briar/android/panic/PanicResponderActivity.java

@@ -19,7 +19,6 @@ import info.guardianproject.panic.Panic;
 import info.guardianproject.panic.PanicResponder;
 import info.guardianproject.trustedintents.TrustedIntents;
 
-import static android.os.Build.VERSION.SDK_INT;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.briar.android.panic.PanicPreferencesFragment.KEY_LOCK;
 import static org.briarproject.briar.android.panic.PanicPreferencesFragment.KEY_PURGE;
@@ -73,12 +72,7 @@ public class PanicResponderActivity extends BriarActivity {
 				}
 			}
 		}
-
+		finishAndRemoveTask();
-		if (SDK_INT >= 21) {
-			finishAndRemoveTask();
-		} else {
-			finish();
-		}
 	}
 
 	@Override

briar-android/src/main/java/org/briarproject/briar/android/removabledrive/ReceiveFragment.java

@@ -20,7 +20,6 @@ import javax.inject.Inject;
 
 import androidx.activity.result.ActivityResultLauncher;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;
 import androidx.lifecycle.ViewModelProvider;
@@ -31,7 +30,6 @@ import static org.briarproject.briar.android.AppModule.getAndroidComponent;
 import static org.briarproject.briar.android.util.UiUtils.hideViewOnSmallScreen;
 import static org.briarproject.briar.android.util.UiUtils.launchActivityToOpenFile;
 
-@RequiresApi(19)
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class ReceiveFragment extends Fragment {

briar-android/src/main/java/org/briarproject/briar/android/removabledrive/RemovableDriveActivity.java

@@ -19,7 +19,6 @@ import javax.inject.Inject;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.annotation.StringRes;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentManager;
@@ -29,7 +28,6 @@ import static java.util.Objects.requireNonNull;
 import static org.briarproject.briar.android.conversation.ConversationActivity.CONTACT_ID;
 import static org.briarproject.briar.android.util.UiUtils.showFragment;
 
-@RequiresApi(19)
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class RemovableDriveActivity extends BriarActivity {

briar-android/src/main/java/org/briarproject/briar/android/removabledrive/SendFragment.java

@@ -24,7 +24,6 @@ import javax.inject.Inject;
 
 import androidx.activity.result.ActivityResultLauncher;
 import androidx.annotation.Nullable;
-import androidx.annotation.RequiresApi;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;
 import androidx.lifecycle.ViewModelProvider;
@@ -38,7 +37,6 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.AppModule.getAndroidComponent;
 import static org.briarproject.briar.android.util.UiUtils.hideViewOnSmallScreen;
 
-@RequiresApi(19)
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public class SendFragment extends Fragment {

briar-android/src/main/java/org/briarproject/briar/android/reporting/BriarReportCollector.java

@@ -220,10 +220,10 @@ class BriarReportCollector {
 				method.setAccessible(true);
 				mobileEnabled = (Boolean) requireNonNull(method.invoke(cm));
 			} catch (ClassNotFoundException
-					| NoSuchMethodException
+			         | NoSuchMethodException
-					| IllegalArgumentException
+			         | IllegalArgumentException
-					| InvocationTargetException
+			         | InvocationTargetException
-					| IllegalAccessException e) {
+			         | IllegalAccessException e) {
 				connectivityInfo
 						.add("MobileDataReflectionException", e.toString());
 			}
@@ -300,15 +300,12 @@ class BriarReportCollector {
 					scanMode == SCAN_MODE_CONNECTABLE_DISCOVERABLE;
 			connectivityInfo.add("BluetoothDiscoverable", btDiscoverable);
 
-			if (SDK_INT >= 21) {
+			// Is Bluetooth LE scanning and advertising supported?
-				// Is Bluetooth LE scanning and advertising supported?
+			boolean btLeScan = bt.getBluetoothLeScanner() != null;
-				boolean btLeScan = bt.getBluetoothLeScanner() != null;
+			connectivityInfo.add("BluetoothLeScanningSupported", btLeScan);
-				connectivityInfo.add("BluetoothLeScanningSupported", btLeScan);
+			boolean btLeAdvertise = bt.getBluetoothLeAdvertiser() != null;
-				boolean btLeAdvertise =
+			connectivityInfo.add("BluetoothLeAdvertisingSupported",
-						bt.getBluetoothLeAdvertiser() != null;
+					btLeAdvertise);
-				connectivityInfo.add("BluetoothLeAdvertisingSupported",
-						btLeAdvertise);
-			}
 
 			Pair<String, String> p = getBluetoothAddressAndMethod(ctx, bt);
 			String address = p.getFirst();

briar-android/src/main/java/org/briarproject/briar/android/reporting/ReportFormFragment.java

@@ -1,6 +1,5 @@
 package org.briarproject.briar.android.reporting;
 
-import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
@@ -33,13 +32,11 @@ import androidx.recyclerview.widget.RecyclerView;
 import static android.view.View.GONE;
 import static android.view.View.INVISIBLE;
 import static android.view.View.VISIBLE;
-import static android.widget.Toast.LENGTH_LONG;
 import static android.widget.Toast.LENGTH_SHORT;
 import static java.util.Objects.requireNonNull;
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.android.util.UiUtils.onSingleLinkClick;
+import static org.briarproject.briar.android.util.UiUtils.tryToStartActivity;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -180,13 +177,7 @@ public class ReportFormFragment extends BaseFragment {
 	private void triggerPrivacyPolicy() {
 		Intent i = new Intent(Intent.ACTION_VIEW);
 		i.setData(Uri.parse("https://briarproject.org/privacy-policy/\\"));
-		try {
+		tryToStartActivity(requireActivity(), i);
-			startActivity(i);
-		} catch (ActivityNotFoundException e) {
-			logException(LOG, WARNING, e);
-			Toast.makeText(requireContext(),
-					R.string.error_start_activity, LENGTH_LONG).show();
-		}
 	}
 
 }

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

@@ -1,6 +1,5 @@
 package org.briarproject.briar.android.settings;
 
-import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.Bundle;
@@ -8,7 +7,6 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;
-import android.widget.Toast;
 
 import org.briarproject.briar.BuildConfig;
 import org.briarproject.briar.R;
@@ -21,10 +19,9 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 
-import static android.widget.Toast.LENGTH_LONG;
+import static android.content.Intent.ACTION_VIEW;
-import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.util.LogUtils.logException;
+import static org.briarproject.briar.android.util.UiUtils.tryToStartActivity;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -85,16 +82,9 @@ public class AboutFragment extends Fragment {
 	}
 
 	private void goToUrl(String url) {
-		Intent i = new Intent(Intent.ACTION_VIEW);
+		Intent i = new Intent(ACTION_VIEW);
 		i.setData(Uri.parse(url));
-		try {
+		tryToStartActivity(requireActivity(), i);
-			startActivity(i);
-		} catch (ActivityNotFoundException e) {
-			logException(LOG, WARNING, e);
-			Toast.makeText(requireContext(),
-					R.string.error_start_activity, LENGTH_LONG).show();
-		}
-
 	}
 
 }

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

@@ -27,7 +27,6 @@ import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
 import static android.os.Build.VERSION.SDK_INT;
 import static androidx.core.view.ViewCompat.LAYOUT_DIRECTION_LTR;
 import static java.util.Objects.requireNonNull;
-import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.briar.android.BriarApplication.ENTRY_ACTIVITY;
 import static org.briarproject.briar.android.navdrawer.NavDrawerActivity.SIGN_OUT_URI;
@@ -75,12 +74,6 @@ public class DisplayFragment extends PreferenceFragmentCompat {
 			Locale locale = Localizer.getLocaleFromTag(tag);
 			if (locale == null)
 				throw new IllegalStateException();
-			// Exclude RTL locales on API < 17, they won't be laid out correctly
-			if (SDK_INT < 17 && !isLeftToRight(locale)) {
-				if (LOG.isLoggable(INFO))
-					LOG.info("Skipping RTL locale " + tag);
-				continue;
-			}
 			String nativeName = locale.getDisplayName(locale);
 			// Fallback to English if the name is unknown in both native and
 			// current locale.