Check whether first visible message ID is null before storing.

Store correct original parent ID when rewrapping blog posts

See merge request !534

.gitignore

@@ -9,17 +9,18 @@ Thumbs.db
 .DS_Store
 
 # Eclipse project files
-#.classpath
-#.project
+.classpath
+.project
+.settings
 
 # Local configuration file (sdk path, etc)
 local.properties
 
 # Android Studio
 .idea/*
+!.idea/runConfigurations/
 !.idea/codeStyleSettings.xml
 .gradle
 build/
 *.iml
-.gitignore
-src/test/
+projectFilesBackup/

.gitlab-ci.yml

@@ -0,0 +1,20 @@
+image: registry.gitlab.com/fdroid/ci-images:client-latest
+
+cache:
+  paths:
+    - .gradle/wrapper
+    - .gradle/caches
+
+before_script:
+  - export GRADLE_USER_HOME=$PWD/.gradle
+#  - export ANDROID_COMPILE_SDK=`sed -n 's,.*compileSdkVersion\s*\([0-9][0-9]*\).*,\1,p' app/build.gradle`
+#  - echo y | android --silent update sdk --no-ui --filter android-${ANDROID_COMPILE_SDK}
+
+test:
+  script:
+    - ./gradlew test
+
+after_script:
+    # this file changes every time but should not be cached
+    - rm -f $GRADLE_USER_HOME/caches/modules-2/modules-2.lock
+    - rm -fr $GRADLE_USER_HOME/caches/*/plugin-resolution/

.idea/runConfigurations/All_tests.xml

@@ -0,0 +1,28 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests" type="AndroidJUnit" factoryName="Android JUnit">
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <module name="briar-android" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-android" />
+    <option name="ENV_VARIABLES" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <envs />
+    <patterns />
+    <method>
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-api" run_configuration_type="AndroidJUnit" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-core" run_configuration_type="AndroidJUnit" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-j2se" run_configuration_type="AndroidJUnit" />
+      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in briar-core" run_configuration_type="AndroidJUnit" />
+    </method>
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_bramble_api.xml

@@ -0,0 +1,23 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in bramble-api" type="AndroidJUnit" factoryName="Android JUnit">
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <module name="bramble-api" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-api" />
+    <option name="ENV_VARIABLES" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <envs />
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_bramble_core.xml

@@ -0,0 +1,23 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in bramble-core" type="AndroidJUnit" factoryName="Android JUnit">
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <module name="bramble-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-core" />
+    <option name="ENV_VARIABLES" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <envs />
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_bramble_j2se.xml

@@ -0,0 +1,23 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in bramble-j2se" type="AndroidJUnit" factoryName="Android JUnit">
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <module name="bramble-j2se" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea -Djava.library.path=libs" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-j2se" />
+    <option name="ENV_VARIABLES" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <envs />
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_briar_android.xml

@@ -0,0 +1,23 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in briar-android" type="AndroidJUnit" factoryName="Android JUnit">
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <module name="briar-android" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-android" />
+    <option name="ENV_VARIABLES" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <envs />
+    <patterns />
+    <method />
+  </configuration>
+</component>

.idea/runConfigurations/All_tests_in_briar_core.xml

@@ -0,0 +1,23 @@
+<component name="ProjectRunConfigurationManager">
+  <configuration default="false" name="All tests in briar-core" type="AndroidJUnit" factoryName="Android JUnit">
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
+    <module name="briar-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
+    <option name="PACKAGE_NAME" value="" />
+    <option name="MAIN_CLASS_NAME" value="" />
+    <option name="METHOD_NAME" value="" />
+    <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
+    <option name="PARAMETERS" value="" />
+    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-core" />
+    <option name="ENV_VARIABLES" />
+    <option name="PASS_PARENT_ENVS" value="true" />
+    <option name="TEST_SEARCH_SCOPE">
+      <value defaultName="singleModule" />
+    </option>
+    <envs />
+    <patterns />
+    <method />
+  </configuration>
+</component>

bramble-android/build.gradle

@@ -12,8 +12,8 @@ android {
 	defaultConfig {
 		minSdkVersion 14
 		targetSdkVersion 22
-		versionCode 1
-		versionName "1.0"
+		versionCode 14
+		versionName "0.14"
 		consumerProguardFiles 'proguard-rules.txt'
 	}
 

bramble-android/src/main/java/org/briarproject/bramble/plugin/droidtooth/DroidtoothPlugin.java

@@ -67,6 +67,7 @@ import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_BLUETOOTH;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.ID;
+import static org.briarproject.bramble.api.plugin.BluetoothConstants.PREF_BT_ENABLE;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_ADDRESS;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.PROP_UUID;
 import static org.briarproject.bramble.api.plugin.BluetoothConstants.UUID_BYTES;
@@ -164,7 +165,7 @@ class DroidtoothPlugin implements DuplexPlugin {
 			bind();
 		} else {
 			// Enable Bluetooth if settings allow
-			if (callback.getSettings().getBoolean("enable", false)) {
+			if (callback.getSettings().getBoolean(PREF_BT_ENABLE, false)) {
 				wasEnabledByUs = true;
 				if (adapter.enable()) LOG.info("Enabling Bluetooth");
 				else LOG.info("Could not enable Bluetooth");

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

@@ -79,6 +79,12 @@ import static java.util.logging.Level.WARNING;
 import static net.freehaven.tor.control.TorControlCommands.HS_ADDRESS;
 import static net.freehaven.tor.control.TorControlCommands.HS_PRIVKEY;
 import static org.briarproject.bramble.api.plugin.TorConstants.CONTROL_PORT;
+import static org.briarproject.bramble.api.plugin.TorConstants.ID;
+import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK;
+import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_ALWAYS;
+import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_NEVER;
+import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_NETWORK_WIFI;
+import static org.briarproject.bramble.api.plugin.TorConstants.PREF_TOR_PORT;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubOnion;
 
 @MethodsNotNullByDefault
@@ -182,19 +188,31 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		String torPath = torFile.getAbsolutePath();
 		String configPath = configFile.getAbsolutePath();
 		String pid = String.valueOf(android.os.Process.myPid());
-		String[] cmd = {torPath, "-f", configPath, OWNER, pid};
-		String[] env = {"HOME=" + torDirectory.getAbsolutePath()};
 		Process torProcess;
+		ProcessBuilder pb =
+				new ProcessBuilder(torPath, "-f", configPath, OWNER, pid);
+		Map<String, String> env = pb.environment();
+		env.put("HOME", torDirectory.getAbsolutePath());
+		pb.directory(torDirectory);
 		try {
-			torProcess = Runtime.getRuntime().exec(cmd, env, torDirectory);
+			torProcess = pb.start();
 		} catch (SecurityException | IOException e) {
 			throw new PluginException(e);
 		}
 		// Log the process's standard output until it detaches
 		if (LOG.isLoggable(INFO)) {
 			Scanner stdout = new Scanner(torProcess.getInputStream());
-			while (stdout.hasNextLine()) LOG.info(stdout.nextLine());
+			Scanner stderr = new Scanner(torProcess.getErrorStream());
+			while (stdout.hasNextLine() || stderr.hasNextLine()){
+				if(stdout.hasNextLine()) {
+					LOG.info(stdout.nextLine());
+				}
+				if(stderr.hasNextLine()){
+					LOG.info(stderr.nextLine());
+				}
+			}
 			stdout.close();
+			stderr.close();
 		}
 		try {
 			// Wait for the process to detach or exit
@@ -366,7 +384,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			@Override
 			public void run() {
 				// If there's already a port number stored in config, reuse it
-				String portString = callback.getSettings().get("port");
+				String portString = callback.getSettings().get(PREF_TOR_PORT);
 				int port;
 				if (StringUtils.isNullOrEmpty(portString)) port = 0;
 				else port = Integer.parseInt(portString);
@@ -389,7 +407,7 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				// Store the port number
 				final String localPort = String.valueOf(ss.getLocalPort());
 				Settings s = new Settings();
-				s.put("port", localPort);
+				s.put(PREF_TOR_PORT, localPort);
 				callback.mergeSettings(s);
 				// Create a hidden service if necessary
 				ioExecutor.execute(new Runnable() {
@@ -666,7 +684,8 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 	@Override
 	public void eventOccurred(Event e) {
 		if (e instanceof SettingsUpdatedEvent) {
-			if (((SettingsUpdatedEvent) e).getNamespace().equals("tor")) {
+			SettingsUpdatedEvent s = (SettingsUpdatedEvent) e;
+			if (s.getNamespace().equals(ID.getString())) {
 				LOG.info("Tor settings updated");
 				updateConnectionStatus();
 			}
@@ -688,7 +707,8 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 				boolean blocked = TorNetworkMetadata.isTorProbablyBlocked(
 						country);
 				Settings s = callback.getSettings();
-				boolean useMobileData = s.getBoolean("torOverMobile", true);
+				int network = s.getInt(PREF_TOR_NETWORK,
+						PREF_TOR_NETWORK_ALWAYS);
 
 				if (LOG.isLoggable(INFO)) {
 					LOG.info("Online: " + online + ", wifi: " + wifi);
@@ -703,7 +723,8 @@ class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 					} else if (blocked) {
 						LOG.info("Disabling network, country is blocked");
 						enableNetwork(false);
-					} else if (!wifi && !useMobileData) {
+					} else if (network == PREF_TOR_NETWORK_NEVER
+							|| (network == PREF_TOR_NETWORK_WIFI && !wifi)) {
 						LOG.info("Disabling network due to data setting");
 						enableNetwork(false);
 					} else {

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

@@ -0,0 +1,93 @@
+package org.briarproject.bramble.system;
+
+import android.app.Application;
+import android.bluetooth.BluetoothAdapter;
+import android.bluetooth.BluetoothDevice;
+import android.content.ContentResolver;
+import android.content.Context;
+import android.net.wifi.WifiConfiguration;
+import android.net.wifi.WifiManager;
+import android.os.Build;
+import android.os.Parcel;
+import android.provider.Settings;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.util.List;
+
+import javax.annotation.concurrent.Immutable;
+import javax.inject.Inject;
+
+import static android.content.Context.WIFI_SERVICE;
+import static android.provider.Settings.Secure.ANDROID_ID;
+
+@Immutable
+@NotNullByDefault
+class AndroidSecureRandomProvider extends LinuxSecureRandomProvider {
+
+	private static final int SEED_LENGTH = 32;
+
+	private final Context appContext;
+
+	@Inject
+	AndroidSecureRandomProvider(Application app) {
+		appContext = app.getApplicationContext();
+	}
+
+	@Override
+	protected void writeToEntropyPool(DataOutputStream out) throws IOException {
+		super.writeToEntropyPool(out);
+		out.writeInt(android.os.Process.myPid());
+		out.writeInt(android.os.Process.myTid());
+		out.writeInt(android.os.Process.myUid());
+		if (Build.FINGERPRINT != null) out.writeUTF(Build.FINGERPRINT);
+		if (Build.SERIAL != null) out.writeUTF(Build.SERIAL);
+		ContentResolver contentResolver = appContext.getContentResolver();
+		String id = Settings.Secure.getString(contentResolver, ANDROID_ID);
+		if (id != null) out.writeUTF(id);
+		Parcel parcel = Parcel.obtain();
+		WifiManager wm =
+				(WifiManager) appContext.getSystemService(WIFI_SERVICE);
+		List<WifiConfiguration> configs = wm.getConfiguredNetworks();
+		if (configs != null) {
+			for (WifiConfiguration config : configs)
+				parcel.writeParcelable(config, 0);
+		}
+		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
+		if (bt != null) {
+			for (BluetoothDevice device : bt.getBondedDevices())
+				parcel.writeParcelable(device, 0);
+		}
+		out.write(parcel.marshall());
+		parcel.recycle();
+	}
+
+	@Override
+	protected void writeSeed() {
+		super.writeSeed();
+		if (Build.VERSION.SDK_INT >= 16 && Build.VERSION.SDK_INT <= 18)
+			applyOpenSslFix();
+	}
+
+	// Based on https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html
+	private void applyOpenSslFix() {
+		byte[] seed = new LinuxSecureRandomSpi().engineGenerateSeed(
+				SEED_LENGTH);
+		try {
+			// Seed the OpenSSL PRNG
+			Class.forName("org.apache.harmony.xnet.provider.jsse.NativeCrypto")
+					.getMethod("RAND_seed", byte[].class)
+					.invoke(null, 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/AndroidSeedProvider.java

@@ -1,42 +0,0 @@
-package org.briarproject.bramble.system;
-
-import android.app.Application;
-import android.content.ContentResolver;
-import android.content.Context;
-import android.os.Build;
-import android.provider.Settings;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-import java.io.DataOutputStream;
-import java.io.IOException;
-
-import javax.annotation.concurrent.Immutable;
-import javax.inject.Inject;
-
-import static android.provider.Settings.Secure.ANDROID_ID;
-
-@Immutable
-@NotNullByDefault
-class AndroidSeedProvider extends LinuxSeedProvider {
-
-	private final Context appContext;
-
-	@Inject
-	AndroidSeedProvider(Application app) {
-		appContext = app.getApplicationContext();
-	}
-
-	@Override
-	void writeToEntropyPool(DataOutputStream out) throws IOException {
-		out.writeInt(android.os.Process.myPid());
-		out.writeInt(android.os.Process.myTid());
-		out.writeInt(android.os.Process.myUid());
-		if (Build.FINGERPRINT != null) out.writeUTF(Build.FINGERPRINT);
-		if (Build.SERIAL != null) out.writeUTF(Build.SERIAL);
-		ContentResolver contentResolver = appContext.getContentResolver();
-		String id = Settings.Secure.getString(contentResolver, ANDROID_ID);
-		if (id != null) out.writeUTF(id);
-		super.writeToEntropyPool(out);
-	}
-}

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

@@ -4,7 +4,7 @@ import android.app.Application;
 
 import org.briarproject.bramble.api.system.AndroidExecutor;
 import org.briarproject.bramble.api.system.LocationUtils;
-import org.briarproject.bramble.api.system.SeedProvider;
+import org.briarproject.bramble.api.system.SecureRandomProvider;
 
 import javax.inject.Singleton;
 
@@ -16,8 +16,8 @@ public class AndroidSystemModule {
 
 	@Provides
 	@Singleton
-	SeedProvider provideSeedProvider(Application app) {
-		return new AndroidSeedProvider(app);
+	SecureRandomProvider provideSecureRandomProvider(Application app) {
+		return new AndroidSecureRandomProvider(app);
 	}
 
 	@Provides

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

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.api;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.util.StringUtils;
 
 import java.util.Arrays;
 import java.util.Comparator;
@@ -53,6 +54,12 @@ public class Bytes implements Comparable<Bytes> {
 		return aBytes.length - bBytes.length;
 	}
 
+	@Override
+	public String toString() {
+		return getClass().getSimpleName() +
+				"(" + StringUtils.toHexString(getBytes()) + ")";
+	}
+
 	public static class BytesComparator implements Comparator<Bytes> {
 
 		@Override

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

@@ -6,9 +6,9 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 public interface PasswordStrengthEstimator {
 
 	float NONE = 0;
-	float WEAK = 0.4f;
-	float QUITE_WEAK = 0.6f;
-	float QUITE_STRONG = 0.8f;
+	float WEAK = 0.25f;
+	float QUITE_WEAK = 0.5f;
+	float QUITE_STRONG = 0.75f;
 	float STRONG = 1;
 
 	/**

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

@@ -13,7 +13,9 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class Author {
 
-	public enum Status {ANONYMOUS, UNKNOWN, UNVERIFIED, VERIFIED, OURSELVES}
+	public enum Status {
+		NONE, ANONYMOUS, UNKNOWN, UNVERIFIED, VERIFIED, OURSELVES
+	}
 
 	private final AuthorId id;
 	private final String name;

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

@@ -9,4 +9,5 @@ public interface BluetoothConstants {
 	String PROP_ADDRESS = "address";
 	String PROP_UUID = "uuid";
 
+	String PREF_BT_ENABLE = "enable";
 }

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

@@ -4,4 +4,5 @@ public interface LanTcpConstants {
 
 	TransportId ID = new TransportId("org.briarproject.bramble.lan");
 
+	String PREF_LAN_IP_PORTS = "ipPorts";
 }

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

@@ -8,4 +8,12 @@ public interface TorConstants {
 	int CONTROL_PORT = 59051;
 
 	int CONNECT_TO_PROXY_TIMEOUT = 5000; // Milliseconds
+	int EXTRA_SOCKET_TIMEOUT = 30000; // Milliseconds
+
+	String PREF_TOR_NETWORK = "network";
+	String PREF_TOR_PORT = "port";
+
+	int PREF_TOR_NETWORK_NEVER = 0;
+	int PREF_TOR_NETWORK_WIFI = 1;
+	int PREF_TOR_NETWORK_ALWAYS = 2;
 }

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

@@ -0,0 +1,23 @@
+package org.briarproject.bramble.api.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.security.Provider;
+import java.security.SecureRandom;
+
+import javax.annotation.Nullable;
+
+/**
+ * Wrapper for a platform-specific secure random number generator.
+ */
+@NotNullByDefault
+public interface SecureRandomProvider {
+
+	/**
+	 * Returns a {@link Provider} that provides a strong {@link SecureRandom}
+	 * implementation, or null if the platform's default implementation should
+	 * be used.
+	 */
+	@Nullable
+	Provider getProvider();
+}

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

@@ -1,18 +0,0 @@
-package org.briarproject.bramble.api.system;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * Uses a platform-specific source to provide a seed for a pseudo-random
- * number generator.
- */
-@NotNullByDefault
-public interface SeedProvider {
-
-	/**
-	 * The length of the seed in bytes.
-	 */
-	int SEED_BYTES = 32;
-
-	byte[] getSeed();
-}

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

@@ -19,7 +19,7 @@ public class PrivacyUtils {
 
 	@Nullable
 	public static String scrubMacAddress(@Nullable String address) {
-		if (address == null) return null;
+		if (address == null || address.length() == 0) return null;
 		// this is a fake address we need to know about
 		if (address.equals("02:00:00:00:00:00")) return address;
 		// keep first and last octet of MAC address

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

@@ -0,0 +1,84 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.concurrent.Executor;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.GuardedBy;
+
+import static java.util.logging.Level.FINE;
+
+/**
+ * An {@link Executor} that delegates its tasks to another {@link Executor}
+ * while limiting the number of tasks that are delegated concurrently. Tasks
+ * are delegated in the order they are submitted to this executor.
+ */
+@NotNullByDefault
+public class PoliteExecutor implements Executor {
+
+	private static final Level LOG_LEVEL = FINE;
+
+	private final Object lock = new Object();
+	@GuardedBy("lock")
+	private final Queue<Runnable> queue = new LinkedList<Runnable>();
+	private final Executor delegate;
+	private final int maxConcurrentTasks;
+	private final Logger log;
+
+	@GuardedBy("lock")
+	private int concurrentTasks = 0;
+
+	/**
+	 * @param tag the tag to be used for logging
+	 * @param delegate the executor to which tasks will be delegated
+	 * @param maxConcurrentTasks the maximum number of tasks that will be
+	 * delegated concurrently. If this is set to 1, tasks submitted to this
+	 * executor will run in the order they are submitted and will not run
+	 * concurrently
+	 */
+	public PoliteExecutor(String tag, Executor delegate,
+			int maxConcurrentTasks) {
+		this.delegate = delegate;
+		this.maxConcurrentTasks = maxConcurrentTasks;
+		log = Logger.getLogger(tag);
+	}
+
+	@Override
+	public void execute(final Runnable r) {
+		final long submitted = System.currentTimeMillis();
+		Runnable wrapped = new Runnable() {
+			@Override
+			public void run() {
+				if (log.isLoggable(LOG_LEVEL)) {
+					long queued = System.currentTimeMillis() - submitted;
+					log.log(LOG_LEVEL, "Queue time " + queued + " ms");
+				}
+				try {
+					r.run();
+				} finally {
+					scheduleNext();
+				}
+			}
+		};
+		synchronized (lock) {
+			if (concurrentTasks < maxConcurrentTasks) {
+				concurrentTasks++;
+				delegate.execute(wrapped);
+			} else {
+				queue.add(wrapped);
+			}
+		}
+	}
+
+	private void scheduleNext() {
+		synchronized (lock) {
+			Runnable next = queue.poll();
+			if (next == null) concurrentTasks--;
+			else delegate.execute(next);
+		}
+	}
+}

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

@@ -0,0 +1,49 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.RejectedExecutionHandler;
+import java.util.concurrent.ThreadPoolExecutor;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.FINE;
+
+@NotNullByDefault
+public class TimeLoggingExecutor extends ThreadPoolExecutor {
+
+	private static final Level LOG_LEVEL = FINE;
+
+	private final Logger log;
+
+	public TimeLoggingExecutor(String tag, int corePoolSize, int maxPoolSize,
+			long keepAliveTime, TimeUnit unit,
+			BlockingQueue<Runnable> workQueue,
+			RejectedExecutionHandler handler) {
+		super(corePoolSize, maxPoolSize, keepAliveTime, unit, workQueue,
+				handler);
+		log = Logger.getLogger(tag);
+	}
+
+	@Override
+	public void execute(final Runnable r) {
+		if (log.isLoggable(LOG_LEVEL)) {
+			final long submitted = System.currentTimeMillis();
+			super.execute(new Runnable() {
+				@Override
+				public void run() {
+					long started = System.currentTimeMillis();
+					long queued = started - submitted;
+					log.log(LOG_LEVEL, "Queue time " + queued + " ms");
+					r.run();
+					long executing = System.currentTimeMillis() - started;
+					log.log(LOG_LEVEL, "Execution time " + executing + " ms");
+				}
+			});
+		} else {
+			super.execute(r);
+		}
+	}
+}

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

@@ -1,62 +0,0 @@
-package org.briarproject.bramble.crypto;
-
-import java.security.Provider;
-import java.security.SecureRandom;
-import java.security.SecureRandomSpi;
-
-/**
- * A {@link SecureRandom} implementation that combines the outputs of two or
- * more other implementations using XOR.
- */
-class CombinedSecureRandom extends SecureRandom {
-
-	private static final Provider PROVIDER = new CombinedProvider();
-
-	CombinedSecureRandom(SecureRandom... randoms) {
-		super(new CombinedSecureRandomSpi(randoms), PROVIDER);
-	}
-
-	private static class CombinedSecureRandomSpi extends SecureRandomSpi {
-
-		private final SecureRandom[] randoms;
-
-		private CombinedSecureRandomSpi(SecureRandom... randoms) {
-			if (randoms.length < 2) throw new IllegalArgumentException();
-			this.randoms = randoms;
-		}
-
-		@Override
-		protected byte[] engineGenerateSeed(int numBytes) {
-			byte[] combined = new byte[numBytes];
-			for (SecureRandom random : randoms) {
-				byte[] b = random.generateSeed(numBytes);
-				int length = Math.min(numBytes, b.length);
-				for (int i = 0; i < length; i++)
-					combined[i] = (byte) (combined[i] ^ b[i]);
-			}
-			return combined;
-		}
-
-		@Override
-		protected void engineNextBytes(byte[] b) {
-			byte[] temp = new byte[b.length];
-			for (SecureRandom random : randoms) {
-				random.nextBytes(temp);
-				for (int i = 0; i < b.length; i++)
-					b[i] = (byte) (b[i] ^ temp[i]);
-			}
-		}
-
-		@Override
-		protected void engineSetSeed(byte[] seed) {
-			for (SecureRandom random : randoms) random.setSeed(seed);
-		}
-	}
-
-	private static class CombinedProvider extends Provider {
-
-		private CombinedProvider() {
-			super("Combined", 1.0, "");
-		}
-	}
-}

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

@@ -8,7 +8,7 @@ import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.plugin.TransportId;
-import org.briarproject.bramble.api.system.SeedProvider;
+import org.briarproject.bramble.api.system.SecureRandomProvider;
 import org.briarproject.bramble.api.transport.IncomingKeys;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
 import org.briarproject.bramble.api.transport.TransportKeys;
@@ -29,7 +29,10 @@ import org.spongycastle.crypto.params.KeyParameter;
 
 import java.nio.charset.Charset;
 import java.security.GeneralSecurityException;
+import java.security.NoSuchAlgorithmException;
+import java.security.Provider;
 import java.security.SecureRandom;
+import java.security.Security;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -101,16 +104,26 @@ class CryptoComponentImpl implements CryptoComponent {
 	private final MessageEncrypter messageEncrypter;
 
 	@Inject
-	CryptoComponentImpl(SeedProvider seedProvider) {
-		if (!FortunaSecureRandom.selfTest()) throw new RuntimeException();
-		SecureRandom platformSecureRandom = new SecureRandom();
+	CryptoComponentImpl(SecureRandomProvider secureRandomProvider) {
 		if (LOG.isLoggable(INFO)) {
-			String provider = platformSecureRandom.getProvider().getName();
-			String algorithm = platformSecureRandom.getAlgorithm();
-			LOG.info("Default SecureRandom: " + provider + " " + algorithm);
+			SecureRandom defaultSecureRandom = new SecureRandom();
+			String name = defaultSecureRandom.getProvider().getName();
+			String algorithm = defaultSecureRandom.getAlgorithm();
+			LOG.info("Default SecureRandom: " + name + " " + algorithm);
 		}
-		SecureRandom fortuna = new FortunaSecureRandom(seedProvider.getSeed());
-		secureRandom = new CombinedSecureRandom(platformSecureRandom, fortuna);
+		Provider provider = secureRandomProvider.getProvider();
+		if (provider == null) {
+			LOG.info("Using default");
+		} else {
+			installSecureRandomProvider(provider);
+			if (LOG.isLoggable(INFO)) {
+				SecureRandom installedSecureRandom = new SecureRandom();
+				String name = installedSecureRandom.getProvider().getName();
+				String algorithm = installedSecureRandom.getAlgorithm();
+				LOG.info("Installed SecureRandom: " + name + " " + algorithm);
+			}
+		}
+		secureRandom = new SecureRandom();
 		ECKeyGenerationParameters params = new ECKeyGenerationParameters(
 				PARAMETERS, secureRandom);
 		agreementKeyPairGenerator = new ECKeyPairGenerator();
@@ -124,6 +137,31 @@ class CryptoComponentImpl implements CryptoComponent {
 		messageEncrypter = new MessageEncrypter(secureRandom);
 	}
 
+	// Based on https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html
+	private void installSecureRandomProvider(Provider provider) {
+		Provider[] providers = Security.getProviders("SecureRandom.SHA1PRNG");
+		if (providers == null || providers.length == 0
+				|| !provider.getClass().equals(providers[0].getClass())) {
+			Security.insertProviderAt(provider, 1);
+		}
+		// Check the new provider is the default when no algorithm is specified
+		SecureRandom random = new SecureRandom();
+		if (!provider.getClass().equals(random.getProvider().getClass())) {
+			throw new SecurityException("Wrong SecureRandom provider: "
+					+ random.getProvider().getClass());
+		}
+		// Check the new provider is the default when SHA1PRNG is specified
+		try {
+			random = SecureRandom.getInstance("SHA1PRNG");
+		} catch (NoSuchAlgorithmException e) {
+			throw new SecurityException(e);
+		}
+		if (!provider.getClass().equals(random.getProvider().getClass())) {
+			throw new SecurityException("Wrong SHA1PRNG provider: "
+					+ random.getProvider().getClass());
+		}
+	}
+
 	@Override
 	public SecretKey generateSecretKey() {
 		byte[] b = new byte[SecretKey.LENGTH];
@@ -133,7 +171,10 @@ class CryptoComponentImpl implements CryptoComponent {
 
 	@Override
 	public PseudoRandom getPseudoRandom(int seed1, int seed2) {
-		return new PseudoRandomImpl(seed1, seed2);
+		byte[] seed = new byte[INT_32_BYTES * 2];
+		ByteUtils.writeUint32(seed1, seed, 0);
+		ByteUtils.writeUint32(seed2, seed, INT_32_BYTES);
+		return new PseudoRandomImpl(seed);
 	}
 
 	@Override
@@ -296,7 +337,7 @@ class CryptoComponentImpl implements CryptoComponent {
 	public SecretKey deriveMasterSecret(byte[] theirPublicKey,
 			KeyPair ourKeyPair, boolean alice) throws GeneralSecurityException {
 		return deriveMasterSecret(deriveSharedSecret(
-				theirPublicKey,ourKeyPair, alice));
+				theirPublicKey, ourKeyPair, alice));
 	}
 
 	@Override
@@ -607,7 +648,7 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	private long sampleRunningTime(int iterations) {
-		byte[] password = { 'p', 'a', 's', 's', 'w', 'o', 'r', 'd' };
+		byte[] password = {'p', 'a', 's', 's', 'w', 'o', 'r', 'd'};
 		byte[] salt = new byte[PBKDF_SALT_BYTES];
 		int keyLengthInBits = SecretKey.LENGTH * 8;
 		long start = System.nanoTime();

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

@@ -1,12 +1,13 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.TimeLoggingExecutor;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
 import org.briarproject.bramble.api.crypto.StreamDecrypterFactory;
 import org.briarproject.bramble.api.crypto.StreamEncrypterFactory;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
-import org.briarproject.bramble.api.system.SeedProvider;
+import org.briarproject.bramble.api.system.SecureRandomProvider;
 
 import java.security.SecureRandom;
 import java.util.concurrent.BlockingQueue;
@@ -31,14 +32,17 @@ public class CryptoModule {
 	public static class EagerSingletons {
 		@Inject
 		@CryptoExecutor
-		Executor cryptoExecutor;
+		ExecutorService cryptoExecutor;
 	}
 
 	/**
 	 * The maximum number of executor threads.
+	 * <p>
+	 * The number of available processors can change during the lifetime of the
+	 * JVM, so this is just a reasonable guess.
 	 */
 	private static final int MAX_EXECUTOR_THREADS =
-			Runtime.getRuntime().availableProcessors();
+			Math.max(1, Runtime.getRuntime().availableProcessors() - 1);
 
 	private final ExecutorService cryptoExecutor;
 
@@ -49,8 +53,8 @@ public class CryptoModule {
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();
 		// Create a limited # of threads and keep them in the pool for 60 secs
-		cryptoExecutor = new ThreadPoolExecutor(0, MAX_EXECUTOR_THREADS,
-				60, SECONDS, queue, policy);
+		cryptoExecutor = new TimeLoggingExecutor("CryptoExecutor", 0,
+				MAX_EXECUTOR_THREADS, 60, SECONDS, queue, policy);
 	}
 
 	@Provides
@@ -60,8 +64,9 @@ public class CryptoModule {
 
 	@Provides
 	@Singleton
-	CryptoComponent provideCryptoComponent(SeedProvider seedProvider) {
-		return new CryptoComponentImpl(seedProvider);
+	CryptoComponent provideCryptoComponent(
+			SecureRandomProvider secureRandomProvider) {
+		return new CryptoComponentImpl(secureRandomProvider);
 	}
 
 	@Provides
@@ -84,11 +89,18 @@ public class CryptoModule {
 	@Provides
 	@Singleton
 	@CryptoExecutor
-	Executor getCryptoExecutor(LifecycleManager lifecycleManager) {
+	ExecutorService getCryptoExecutorService(
+			LifecycleManager lifecycleManager) {
 		lifecycleManager.registerForShutdown(cryptoExecutor);
 		return cryptoExecutor;
 	}
 
+	@Provides
+	@CryptoExecutor
+	Executor getCryptoExecutor() {
+		return cryptoExecutor;
+	}
+
 	@Provides
 	SecureRandom getSecureRandom(CryptoComponent crypto) {
 		return crypto.getSecureRandom();

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

@@ -1,76 +0,0 @@
-package org.briarproject.bramble.crypto;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.spongycastle.crypto.Digest;
-
-import javax.annotation.concurrent.NotThreadSafe;
-
-/**
- * A message digest that prevents length extension attacks - see Ferguson and
- * Schneier, <i>Practical Cryptography</i>, chapter 6.
- * <p>
- * "Let h be an interative hash function. The hash function h<sub>d</sub> is
- * defined by h<sub>d</sub> := h(h(m)), and has a claimed security level of
- * min(k, n/2) where k is the security level of h and n is the size of the hash
- * result."
- */
-@NotThreadSafe
-@NotNullByDefault
-class DoubleDigest implements Digest {
-
-	private final Digest delegate;
-
-	DoubleDigest(Digest delegate) {
-		this.delegate = delegate;
-	}
-
-	private byte[] digest() {
-		byte[] digest = new byte[delegate.getDigestSize()];
-		delegate.doFinal(digest, 0); // h(m)
-		delegate.update(digest, 0, digest.length);
-		delegate.doFinal(digest, 0); // h(h(m))
-		return digest;
-	}
-
-	public int digest(byte[] buf, int offset, int len) {
-		byte[] digest = digest();
-		len = Math.min(len, digest.length);
-		System.arraycopy(digest, 0, buf, offset, len);
-		return len;
-	}
-
-	@Override
-	public int getDigestSize() {
-		return delegate.getDigestSize();
-	}
-
-	@Override
-	public String getAlgorithmName() {
-		return "Double " + delegate.getAlgorithmName();
-	}
-
-	@Override
-	public void reset() {
-		delegate.reset();
-	}
-
-	@Override
-	public void update(byte input) {
-		delegate.update(input);
-	}
-
-	public void update(byte[] input) {
-		delegate.update(input, 0, input.length);
-	}
-
-	@Override
-	public void update(byte[] input, int offset, int len) {
-		delegate.update(input, offset, len);
-	}
-
-	@Override
-	public int doFinal(byte[] out, int outOff) {
-		return digest(out, outOff, delegate.getDigestSize());
-	}
-
-}

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

@@ -1,114 +0,0 @@
-package org.briarproject.bramble.crypto;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.spongycastle.crypto.BlockCipher;
-import org.spongycastle.crypto.digests.SHA256Digest;
-import org.spongycastle.crypto.engines.AESLightEngine;
-import org.spongycastle.crypto.params.KeyParameter;
-
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-/**
- * Implements the Fortuna pseudo-random number generator, as described in
- * Ferguson and Schneier, <i>Practical Cryptography</i>, chapter 9.
- */
-@ThreadSafe
-@NotNullByDefault
-class FortunaGenerator {
-
-	private static final int MAX_BYTES_PER_REQUEST = 1024 * 1024;
-	private static final int KEY_BYTES = 32;
-	private static final int BLOCK_BYTES = 16;
-
-	private final Lock lock = new ReentrantLock();
-
-	// The following are locking: lock
-	private final DoubleDigest digest = new DoubleDigest(new SHA256Digest());
-	private final BlockCipher cipher = new AESLightEngine();
-	private final byte[] key = new byte[KEY_BYTES];
-	private final byte[] counter = new byte[BLOCK_BYTES];
-	private final byte[] buffer = new byte[BLOCK_BYTES];
-	private final byte[] newKey = new byte[KEY_BYTES];
-
-	FortunaGenerator(byte[] seed) {
-		reseed(seed);
-	}
-
-	void reseed(byte[] seed) {
-		lock.lock();
-		try {
-			digest.update(key);
-			digest.update(seed);
-			digest.digest(key, 0, KEY_BYTES);
-			incrementCounter();
-		} finally {
-			lock.unlock();
-		}
-
-	}
-
-	// Package access for testing
-	void incrementCounter() {
-		lock.lock();
-		try {
-			counter[0]++;
-			for (int i = 0; counter[i] == 0; i++) {
-				if (i + 1 == BLOCK_BYTES)
-					throw new RuntimeException("Counter exhausted");
-				counter[i + 1]++;
-			}
-		} finally {
-			lock.unlock();
-		}
-	}
-
-	// Package access for testing
-	byte[] getCounter() {
-		lock.lock();
-		try {
-			return counter;
-		} finally {
-			lock.unlock();
-		}
-
-	}
-
-	int nextBytes(byte[] dest, int off, int len) {
-		lock.lock();
-		try {
-			// Don't write more than the maximum number of bytes in one request
-			if (len > MAX_BYTES_PER_REQUEST) len = MAX_BYTES_PER_REQUEST;
-			cipher.init(true, new KeyParameter(key));
-			// Generate full blocks directly into the output buffer
-			int fullBlocks = len / BLOCK_BYTES;
-			for (int i = 0; i < fullBlocks; i++) {
-				cipher.processBlock(counter, 0, dest, off + i * BLOCK_BYTES);
-				incrementCounter();
-			}
-			// Generate a partial block if needed
-			int done = fullBlocks * BLOCK_BYTES, remaining = len - done;
-			if (remaining >= BLOCK_BYTES) throw new AssertionError();
-			if (remaining > 0) {
-				cipher.processBlock(counter, 0, buffer, 0);
-				incrementCounter();
-				// Copy the partial block to the output buffer and erase our copy
-				System.arraycopy(buffer, 0, dest, off + done, remaining);
-				for (int i = 0; i < BLOCK_BYTES; i++) buffer[i] = 0;
-			}
-			// Generate a new key
-			for (int i = 0; i < KEY_BYTES / BLOCK_BYTES; i++) {
-				cipher.processBlock(counter, 0, newKey, i * BLOCK_BYTES);
-				incrementCounter();
-			}
-			System.arraycopy(newKey, 0, key, 0, KEY_BYTES);
-			for (int i = 0; i < KEY_BYTES; i++) newKey[i] = 0;
-			// Return the number of bytes written
-			return len;
-		} finally {
-			lock.unlock();
-		}
-	}
-}

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

@@ -1,81 +0,0 @@
-package org.briarproject.bramble.crypto;
-
-import org.briarproject.bramble.util.StringUtils;
-
-import java.security.Provider;
-import java.security.SecureRandom;
-import java.security.SecureRandomSpi;
-import java.util.Arrays;
-
-/**
- * A {@link java.security.SecureRandom SecureRandom} implementation based on a
- * {@link FortunaGenerator}.
- */
-class FortunaSecureRandom extends SecureRandom {
-
-	// Package access for testing
-	static final byte[] SELF_TEST_VECTOR_1 =
-			StringUtils.fromHexString("4BD6EA599D47E3EE9DD911833C29CA22");
-	static final byte[] SELF_TEST_VECTOR_2 =
-			StringUtils.fromHexString("10984D576E6850E505CA9F42A9BFD88A");
-	static final byte[] SELF_TEST_VECTOR_3 =
-			StringUtils.fromHexString("1E12DA166BD86DCECDE50A8296018DE2");
-
-	private static final Provider PROVIDER = new FortunaProvider();
-
-	FortunaSecureRandom(byte[] seed) {
-		super(new FortunaSecureRandomSpi(seed), PROVIDER);
-	}
-
-	/**
-	 * Tests that the {@link #nextBytes(byte[])} and {@link #setSeed(byte[])}
-	 * methods are passed through to the generator in the expected way.
-	 */
-	static boolean selfTest() {
-		byte[] seed = new byte[32];
-		SecureRandom r = new FortunaSecureRandom(seed);
-		byte[] output = new byte[16];
-		r.nextBytes(output);
-		if (!Arrays.equals(SELF_TEST_VECTOR_1, output)) return false;
-		r.nextBytes(output);
-		if (!Arrays.equals(SELF_TEST_VECTOR_2, output)) return false;
-		r.setSeed(seed);
-		r.nextBytes(output);
-		return Arrays.equals(SELF_TEST_VECTOR_3, output);
-	}
-
-	private static class FortunaSecureRandomSpi extends SecureRandomSpi {
-
-		private final FortunaGenerator generator;
-
-		private FortunaSecureRandomSpi(byte[] seed) {
-			generator = new FortunaGenerator(seed);
-		}
-
-		@Override
-		protected byte[] engineGenerateSeed(int numBytes) {
-			byte[] b = new byte[numBytes];
-			engineNextBytes(b);
-			return b;
-		}
-
-		@Override
-		protected void engineNextBytes(byte[] b) {
-			int offset = 0;
-			while (offset < b.length)
-				offset += generator.nextBytes(b, offset, b.length - offset);
-		}
-
-		@Override
-		protected void engineSetSeed(byte[] seed) {
-			generator.reseed(seed);
-		}
-	}
-
-	private static class FortunaProvider extends Provider {
-
-		private FortunaProvider() {
-			super("Fortuna", 1.0, "");
-		}
-	}
-}

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

@@ -11,31 +11,14 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 class PasswordStrengthEstimatorImpl implements PasswordStrengthEstimator {
 
-	private static final int LOWER = 26;
-	private static final int UPPER = 26;
-	private static final int DIGIT = 10;
-	private static final int OTHER = 10;
-	private static final double STRONG = Math.log(Math.pow(LOWER + UPPER +
-			DIGIT + OTHER, 10));
+	// The minimum number of unique characters in a strong password
+	private static final int STRONG_UNIQUE_CHARS = 12;
 
 	@Override
 	public float estimateStrength(String password) {
 		HashSet<Character> unique = new HashSet<Character>();
 		int length = password.length();
 		for (int i = 0; i < length; i++) unique.add(password.charAt(i));
-		boolean lower = false, upper = false, digit = false, other = false;
-		for (char c : unique) {
-			if (Character.isLowerCase(c)) lower = true;
-			else if (Character.isUpperCase(c)) upper = true;
-			else if (Character.isDigit(c)) digit = true;
-			else other = true;
-		}
-		int alphabetSize = 0;
-		if (lower) alphabetSize += LOWER;
-		if (upper) alphabetSize += UPPER;
-		if (digit) alphabetSize += DIGIT;
-		if (other) alphabetSize += OTHER;
-		double score = Math.log(Math.pow(alphabetSize, unique.size()));
-		return Math.min(1, (float) (score / STRONG));
+		return Math.min(1, (float) unique.size() / STRONG_UNIQUE_CHARS);
 	}
 }

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

@@ -2,30 +2,34 @@ package org.briarproject.bramble.crypto;
 
 import org.briarproject.bramble.api.crypto.PseudoRandom;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.util.ByteUtils;
+import org.spongycastle.crypto.Digest;
+import org.spongycastle.crypto.engines.Salsa20Engine;
+import org.spongycastle.crypto.params.KeyParameter;
+import org.spongycastle.crypto.params.ParametersWithIV;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
-import static org.briarproject.bramble.util.ByteUtils.INT_32_BYTES;
-
 @NotThreadSafe
 @NotNullByDefault
 class PseudoRandomImpl implements PseudoRandom {
 
-	private final FortunaGenerator generator;
+	private final Salsa20Engine cipher = new Salsa20Engine();
 
-	PseudoRandomImpl(int seed1, int seed2) {
-		byte[] seed = new byte[INT_32_BYTES * 2];
-		ByteUtils.writeUint32(seed1, seed, 0);
-		ByteUtils.writeUint32(seed2, seed, INT_32_BYTES);
-		generator = new FortunaGenerator(seed);
+	PseudoRandomImpl(byte[] seed) {
+		// Hash the seed to produce a 32-byte key
+		byte[] key = new byte[32];
+		Digest digest = new Blake2sDigest();
+		digest.update(seed, 0, seed.length);
+		digest.doFinal(key, 0);
+		// Initialise the stream cipher with an all-zero nonce
+		byte[] nonce = new byte[8];
+		cipher.init(true, new ParametersWithIV(new KeyParameter(key), nonce));
 	}
 
 	@Override
 	public byte[] nextBytes(int length) {
-		byte[] b = new byte[length];
-		int offset = 0;
-		while (offset < length) offset += generator.nextBytes(b, offset, length);
-		return b;
+		byte[] in = new byte[length], out = new byte[length];
+		cipher.processBytes(in, 0, length, out, 0);
+		return out;
 	}
 }

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

@@ -62,6 +62,8 @@ class StreamEncrypterImpl implements StreamEncrypter {
 	@Override
 	public void writeFrame(byte[] payload, int payloadLength,
 			int paddingLength, boolean finalFrame) throws IOException {
+		if (payloadLength < 0 || paddingLength < 0)
+			throw new IllegalArgumentException();
 		if (payloadLength + paddingLength > MAX_PAYLOAD_LENGTH)
 			throw new IllegalArgumentException();
 		// Don't allow the frame counter to wrap

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

@@ -67,6 +67,7 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import static java.util.logging.Level.FINE;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
@@ -130,8 +131,14 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		// Don't allow reentrant locking
 		if (lock.getReadHoldCount() > 0) throw new IllegalStateException();
 		if (lock.getWriteHoldCount() > 0) throw new IllegalStateException();
+		long start = System.currentTimeMillis();
 		if (readOnly) lock.readLock().lock();
 		else lock.writeLock().lock();
+		if (LOG.isLoggable(FINE)) {
+			long duration = System.currentTimeMillis() - start;
+			if (readOnly) LOG.fine("Waited " + duration + " ms for read lock");
+			else LOG.fine("Waited " + duration + " ms for write lock");
+		}
 		try {
 			return new Transaction(db.startTransaction(), readOnly);
 		} catch (DbException e) {
@@ -661,7 +668,9 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 				acked.add(m);
 			}
 		}
-		transaction.attach(new MessagesAckedEvent(c, acked));
+		if (acked.size() > 0) {
+			transaction.attach(new MessagesAckedEvent(c, acked));
+		}
 	}
 
 	@Override

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.db;
 
+import org.briarproject.bramble.TimeLoggingExecutor;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 
@@ -36,8 +37,8 @@ public class DatabaseExecutorModule {
 		RejectedExecutionHandler policy =
 				new ThreadPoolExecutor.DiscardPolicy();
 		// Use a single thread and keep it in the pool for 60 secs
-		databaseExecutor = new ThreadPoolExecutor(0, 1, 60, SECONDS, queue,
-				policy);
+		databaseExecutor = new TimeLoggingExecutor("DatabaseExecutor", 0, 1,
+				60, SECONDS, queue, policy);
 	}
 
 	@Provides

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

@@ -68,8 +68,8 @@ import static org.briarproject.bramble.db.ExponentialBackoff.calculateExpiry;
 @NotNullByDefault
 abstract class JdbcDatabase implements Database<Connection> {
 
-	private static final int SCHEMA_VERSION = 29;
-	private static final int MIN_SCHEMA_VERSION = 29;
+	private static final int SCHEMA_VERSION = 30;
+	private static final int MIN_SCHEMA_VERSION = 30;
 
 	private static final String CREATE_SETTINGS =
 			"CREATE TABLE settings"

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

@@ -34,6 +34,7 @@ import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static org.briarproject.bramble.api.keyagreement.KeyAgreementConstants.TRANSPORT_ID_LAN;
 import static org.briarproject.bramble.api.plugin.LanTcpConstants.ID;
+import static org.briarproject.bramble.api.plugin.LanTcpConstants.PREF_LAN_IP_PORTS;
 import static org.briarproject.bramble.util.ByteUtils.MAX_16_BIT_UNSIGNED;
 import static org.briarproject.bramble.util.PrivacyUtils.scrubSocketAddress;
 
@@ -43,7 +44,7 @@ class LanTcpPlugin extends TcpPlugin {
 	private static final Logger LOG =
 			Logger.getLogger(LanTcpPlugin.class.getName());
 
-	private static final int MAX_ADDRESSES = 5;
+	private static final int MAX_ADDRESSES = 4;
 	private static final String PROP_IP_PORTS = "ipPorts";
 	private static final String SEPARATOR = ",";
 
@@ -82,19 +83,19 @@ class LanTcpPlugin extends TcpPlugin {
 	private List<InetSocketAddress> parseSocketAddresses(String ipPorts) {
 		if (StringUtils.isNullOrEmpty(ipPorts)) return Collections.emptyList();
 		String[] split = ipPorts.split(SEPARATOR);
-		List<InetSocketAddress> remotes = new ArrayList<InetSocketAddress>();
+		List<InetSocketAddress> addresses = new ArrayList<InetSocketAddress>();
 		for (String ipPort : split) {
 			InetSocketAddress a = parseSocketAddress(ipPort);
-			if (a != null) remotes.add(a);
+			if (a != null) addresses.add(a);
 		}
-		return remotes;
+		return addresses;
 	}
 
 	@Override
 	protected void setLocalSocketAddress(InetSocketAddress a) {
 		String ipPort = getIpPortString(a);
 		// Get the list of recently used addresses
-		String setting = callback.getSettings().get(PROP_IP_PORTS);
+		String setting = callback.getSettings().get(PREF_LAN_IP_PORTS);
 		List<String> recent = new ArrayList<String>();
 		if (!StringUtils.isNullOrEmpty(setting))
 			Collections.addAll(recent, setting.split(SEPARATOR));
@@ -120,7 +121,7 @@ class LanTcpPlugin extends TcpPlugin {
 		}
 		// Save the setting
 		Settings settings = new Settings();
-		settings.put(PROP_IP_PORTS, setting);
+		settings.put(PREF_LAN_IP_PORTS, setting);
 		callback.mergeSettings(settings);
 	}
 

bramble-core/src/main/java/org/briarproject/bramble/socks/SocksModule.java

@@ -8,6 +8,7 @@ import dagger.Module;
 import dagger.Provides;
 
 import static org.briarproject.bramble.api.plugin.TorConstants.CONNECT_TO_PROXY_TIMEOUT;
+import static org.briarproject.bramble.api.plugin.TorConstants.EXTRA_SOCKET_TIMEOUT;
 import static org.briarproject.bramble.api.plugin.TorConstants.SOCKS_PORT;
 
 @Module
@@ -17,6 +18,7 @@ public class SocksModule {
 	SocketFactory provideTorSocketFactory() {
 		InetSocketAddress proxy = new InetSocketAddress("127.0.0.1",
 				SOCKS_PORT);
-		return new SocksSocketFactory(proxy, CONNECT_TO_PROXY_TIMEOUT);
+		return new SocksSocketFactory(proxy, CONNECT_TO_PROXY_TIMEOUT,
+				EXTRA_SOCKET_TIMEOUT);
 	}
 }

bramble-core/src/main/java/org/briarproject/bramble/socks/SocksSocket.java

@@ -6,18 +6,36 @@ import org.briarproject.bramble.util.IoUtils;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.Socket;
 import java.net.SocketAddress;
+import java.util.Arrays;
 
 class SocksSocket extends Socket {
 
-	private final SocketAddress proxy;
-	private final int connectToProxyTimeout;
+	private static final String[] ERRORS = {
+			"Succeeded",
+			"General SOCKS server failure",
+			"Connection not allowed by ruleset",
+			"Network unreachable",
+			"Host unreachable",
+			"Connection refused",
+			"TTL expired",
+			"Command not supported",
+			"Address type not supported"
+	};
 
-	SocksSocket(SocketAddress proxy, int connectToProxyTimeout) {
+	private static final byte[] UNSPECIFIED_ADDRESS = new byte[4];
+
+	private final SocketAddress proxy;
+	private final int connectToProxyTimeout, extraSocketTimeout;
+
+	SocksSocket(SocketAddress proxy, int connectToProxyTimeout,
+			int extraSocketTimeout) {
 		this.proxy = proxy;
 		this.connectToProxyTimeout = connectToProxyTimeout;
+		this.extraSocketTimeout = extraSocketTimeout;
 	}
 
 	@Override
@@ -28,6 +46,11 @@ class SocksSocket extends Socket {
 		if (!(endpoint instanceof InetSocketAddress))
 			throw new IllegalArgumentException();
 		InetSocketAddress inet = (InetSocketAddress) endpoint;
+		InetAddress address = inet.getAddress();
+		if (address != null
+				&& !Arrays.equals(address.getAddress(), UNSPECIFIED_ADDRESS)) {
+			throw new IllegalArgumentException();
+		}
 		String host = inet.getHostName();
 		if (host.length() > 255) throw new IllegalArgumentException();
 		int port = inet.getPort();
@@ -41,16 +64,16 @@ class SocksSocket extends Socket {
 		sendMethodRequest(out);
 		receiveMethodResponse(in);
 
-		// Use the supplied timeout temporarily
+		// Use the supplied timeout temporarily, plus any configured extra
 		int oldTimeout = getSoTimeout();
-		setSoTimeout(timeout);
+		setSoTimeout(timeout + extraSocketTimeout);
 
 		// Connect to the endpoint via the proxy
 		sendConnectRequest(out, host, port);
 		receiveConnectResponse(in);
 
-		// Restore the old timeout
-		setSoTimeout(oldTimeout);
+		// Restore the old timeout, plus any configured extra
+		setSoTimeout(oldTimeout + extraSocketTimeout);
 	}
 
 	private void sendMethodRequest(OutputStream out) throws IOException {
@@ -93,13 +116,16 @@ class SocksSocket extends Socket {
 	private void receiveConnectResponse(InputStream in) throws IOException {
 		byte[] connectResponse = new byte[4];
 		IoUtils.read(in, connectResponse);
-		byte version = connectResponse[0];
-		byte reply = connectResponse[1];
-		byte addressType = connectResponse[3];
+		int version = connectResponse[0] & 0xFF;
+		int reply = connectResponse[1] & 0xFF;
+		int addressType = connectResponse[3] & 0xFF;
 		if (version != 5)
 			throw new IOException("Unsupported SOCKS version: " + version);
-		if (reply != 0)
-			throw new IOException("Connection failed: " + reply);
+		if (reply != 0) {
+			if (reply < ERRORS.length)
+				throw new IOException("Connection failed: " + ERRORS[reply]);
+			else throw new IOException("Connection failed: " + reply);
+		}
 		if (addressType == 1) IoUtils.read(in, new byte[4]); // IPv4
 		else if (addressType == 4) IoUtils.read(in, new byte[16]); // IPv6
 		else throw new IOException("Unsupported address type: " + addressType);

bramble-core/src/main/java/org/briarproject/bramble/socks/SocksSocketFactory.java

@@ -11,16 +11,18 @@ import javax.net.SocketFactory;
 class SocksSocketFactory extends SocketFactory {
 
 	private final SocketAddress proxy;
-	private final int connectToProxyTimeout;
+	private final int connectToProxyTimeout, extraSocketTimeout;
 
-	SocksSocketFactory(SocketAddress proxy, int connectToProxyTimeout) {
+	SocksSocketFactory(SocketAddress proxy, int connectToProxyTimeout,
+			int extraSocketTimeout) {
 		this.proxy = proxy;
 		this.connectToProxyTimeout = connectToProxyTimeout;
+		this.extraSocketTimeout = extraSocketTimeout;
 	}
 
 	@Override
 	public Socket createSocket() {
-		return new SocksSocket(proxy, connectToProxyTimeout);
+		return new SocksSocket(proxy, connectToProxyTimeout, extraSocketTimeout);
 	}
 
 	@Override

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

@@ -1,6 +1,8 @@
 package org.briarproject.bramble.sync;
 
+import org.briarproject.bramble.PoliteExecutor;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.event.EventBus;
@@ -29,6 +31,16 @@ public class SyncModule {
 		ValidationManager validationManager;
 	}
 
+	/**
+	 * The maximum number of validation tasks to delegate to the crypto
+	 * executor concurrently.
+	 * <p>
+	 * The number of available processors can change during the lifetime of the
+	 * JVM, so this is just a reasonable guess.
+	 */
+	private static final int MAX_CONCURRENT_VALIDATION_TASKS =
+			Math.max(1, Runtime.getRuntime().availableProcessors() - 1);
+
 	@Provides
 	GroupFactory provideGroupFactory(CryptoComponent crypto) {
 		return new GroupFactoryImpl(crypto);
@@ -62,10 +74,20 @@ public class SyncModule {
 
 	@Provides
 	@Singleton
-	ValidationManager getValidationManager(LifecycleManager lifecycleManager,
-			EventBus eventBus, ValidationManagerImpl validationManager) {
+	ValidationManager provideValidationManager(
+			LifecycleManager lifecycleManager, EventBus eventBus,
+			ValidationManagerImpl validationManager) {
 		lifecycleManager.registerService(validationManager);
 		eventBus.addListener(validationManager);
 		return validationManager;
 	}
+
+	@Provides
+	@Singleton
+	@ValidationExecutor
+	Executor provideValidationExecutor(
+			@CryptoExecutor Executor cryptoExecutor) {
+		return new PoliteExecutor("ValidationExecutor", cryptoExecutor,
+				MAX_CONCURRENT_VALIDATION_TASKS);
+	}
 }

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

@@ -0,0 +1,25 @@
+package org.briarproject.bramble.sync;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import javax.inject.Qualifier;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+/**
+ * Annotation for injecting the executor for validation tasks. Also used for
+ * annotating methods that should run on the validation executor.
+ * <p>
+ * The contract of this executor is that tasks may be run concurrently, and
+ * submitting a task will never block. Tasks must not run indefinitely. Tasks
+ * submitted during shutdown are discarded.
+ */
+@Qualifier
+@Target({FIELD, METHOD, PARAMETER})
+@Retention(RUNTIME)
+@interface ValidationExecutor {
+}

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.sync;
 
-import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.DbException;
@@ -50,8 +49,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 			Logger.getLogger(ValidationManagerImpl.class.getName());
 
 	private final DatabaseComponent db;
-	private final Executor dbExecutor;
-	private final Executor cryptoExecutor;
+	private final Executor dbExecutor, validationExecutor;
 	private final MessageFactory messageFactory;
 	private final Map<ClientId, MessageValidator> validators;
 	private final Map<ClientId, IncomingMessageHook> hooks;
@@ -60,11 +58,11 @@ class ValidationManagerImpl implements ValidationManager, Service,
 	@Inject
 	ValidationManagerImpl(DatabaseComponent db,
 			@DatabaseExecutor Executor dbExecutor,
-			@CryptoExecutor Executor cryptoExecutor,
+			@ValidationExecutor Executor validationExecutor,
 			MessageFactory messageFactory) {
 		this.db = db;
 		this.dbExecutor = dbExecutor;
-		this.cryptoExecutor = cryptoExecutor;
+		this.validationExecutor = validationExecutor;
 		this.messageFactory = messageFactory;
 		validators = new ConcurrentHashMap<ClientId, MessageValidator>();
 		hooks = new ConcurrentHashMap<ClientId, IncomingMessageHook>();
@@ -104,6 +102,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void validateOutstandingMessages(ClientId c) {
 		try {
 			Queue<MessageId> unvalidated = new LinkedList<MessageId>();
@@ -130,6 +129,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void validateNextMessage(Queue<MessageId> unvalidated) {
 		try {
 			Message m;
@@ -167,6 +167,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void deliverOutstandingMessages(ClientId c) {
 		try {
 			Queue<MessageId> pending = new LinkedList<MessageId>();
@@ -194,6 +195,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void deliverNextPendingMessage(Queue<MessageId> pending) {
 		try {
 			boolean anyInvalid = false, allDelivered = true;
@@ -220,8 +222,8 @@ class ValidationManagerImpl implements ValidationManager, Service,
 						Message m = messageFactory.createMessage(id, raw);
 						Group g = db.getGroup(txn, m.getGroupId());
 						ClientId c = g.getClientId();
-						Metadata meta = db.getMessageMetadataForValidator(txn,
-								id);
+						Metadata meta =
+								db.getMessageMetadataForValidator(txn, id);
 						DeliveryResult result = deliverMessage(txn, m, c, meta);
 						if (result.valid) {
 							pending.addAll(getPendingDependents(txn, id));
@@ -240,8 +242,8 @@ class ValidationManagerImpl implements ValidationManager, Service,
 				db.endTransaction(txn);
 			}
 			if (invalidate != null) invalidateNextMessageAsync(invalidate);
-			deliverNextPendingMessageAsync(pending);
 			if (toShare != null) shareNextMessageAsync(toShare);
+			deliverNextPendingMessageAsync(pending);
 		} catch (NoSuchMessageException e) {
 			LOG.info("Message removed before delivery");
 			deliverNextPendingMessageAsync(pending);
@@ -249,13 +251,12 @@ class ValidationManagerImpl implements ValidationManager, Service,
 			LOG.info("Group removed before delivery");
 			deliverNextPendingMessageAsync(pending);
 		} catch (DbException e) {
-			if (LOG.isLoggable(WARNING))
-				LOG.log(WARNING, e.toString(), e);
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
 		}
 	}
 
 	private void validateMessageAsync(final Message m, final Group g) {
-		cryptoExecutor.execute(new Runnable() {
+		validationExecutor.execute(new Runnable() {
 			@Override
 			public void run() {
 				validateMessage(m, g);
@@ -263,10 +264,12 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@ValidationExecutor
 	private void validateMessage(Message m, Group g) {
 		MessageValidator v = validators.get(g.getClientId());
 		if (v == null) {
-			LOG.warning("No validator");
+			if (LOG.isLoggable(WARNING))
+				LOG.warning("No validator for " + g.getClientId().getString());
 		} else {
 			try {
 				MessageContext context = v.validateMessage(m, g);
@@ -291,6 +294,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void storeMessageContext(Message m, ClientId c,
 			MessageContext context) {
 		try {
@@ -353,6 +357,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
+	@DatabaseExecutor
 	private DeliveryResult deliverMessage(Transaction txn, Message m,
 			ClientId c, Metadata meta) throws DbException {
 		// Deliver the message to the client if it's registered a hook
@@ -362,10 +367,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 			try {
 				shareMsg = hook.incomingMessage(txn, m, meta);
 			} catch (InvalidMessageException e) {
-				// message is invalid, mark it as such and delete it
-				db.setMessageState(txn, m.getId(), INVALID);
-				db.deleteMessageMetadata(txn, m.getId());
-				db.deleteMessage(txn, m.getId());
+				invalidateMessage(txn, m.getId());
 				return new DeliveryResult(false, false);
 			}
 		}
@@ -373,6 +375,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		return new DeliveryResult(true, shareMsg);
 	}
 
+	@DatabaseExecutor
 	private Queue<MessageId> getPendingDependents(Transaction txn, MessageId m)
 			throws DbException {
 		Queue<MessageId> pending = new LinkedList<MessageId>();
@@ -392,6 +395,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void shareOutstandingMessages(ClientId c) {
 		try {
 			Queue<MessageId> toShare = new LinkedList<MessageId>();
@@ -424,6 +428,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void shareNextMessage(Queue<MessageId> toShare) {
 		try {
 			Transaction txn = db.startTransaction(false);
@@ -457,6 +462,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void invalidateNextMessage(Queue<MessageId> invalidate) {
 		try {
 			Transaction txn = db.startTransaction(false);
@@ -479,6 +485,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		}
 	}
 
+	@DatabaseExecutor
 	private void invalidateMessage(Transaction txn, MessageId m)
 			throws DbException {
 		db.setMessageState(txn, m, INVALID);
@@ -486,6 +493,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		db.deleteMessageMetadata(txn, m);
 	}
 
+	@DatabaseExecutor
 	private Queue<MessageId> getDependentsToInvalidate(Transaction txn,
 			MessageId m) throws DbException {
 		Queue<MessageId> invalidate = new LinkedList<MessageId>();
@@ -515,6 +523,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 		});
 	}
 
+	@DatabaseExecutor
 	private void loadGroupAndValidate(final Message m) {
 		try {
 			Group g;
@@ -534,6 +543,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 	}
 
 	private static class DeliveryResult {
+
 		private final boolean valid, share;
 
 		private DeliveryResult(boolean valid, boolean share) {

bramble-core/src/main/java/org/briarproject/bramble/system/AbstractSecureRandomProvider.java

@@ -0,0 +1,42 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.SecureRandomProvider;
+
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.InetAddress;
+import java.net.NetworkInterface;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map.Entry;
+import java.util.Properties;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+abstract class AbstractSecureRandomProvider implements SecureRandomProvider {
+
+	// Contribute whatever slightly unpredictable info we have to the pool
+	protected void writeToEntropyPool(DataOutputStream out) throws IOException {
+		out.writeLong(System.currentTimeMillis());
+		out.writeLong(System.nanoTime());
+		out.writeLong(Runtime.getRuntime().freeMemory());
+		List<NetworkInterface> ifaces =
+				Collections.list(NetworkInterface.getNetworkInterfaces());
+		for (NetworkInterface i : ifaces) {
+			List<InetAddress> addrs = Collections.list(i.getInetAddresses());
+			for (InetAddress a : addrs) out.write(a.getAddress());
+			byte[] hardware = i.getHardwareAddress();
+			if (hardware != null) out.write(hardware);
+		}
+		for (Entry<String, String> e : System.getenv().entrySet()) {
+			out.writeUTF(e.getKey());
+			out.writeUTF(e.getValue());
+		}
+		Properties properties = System.getProperties();
+		for (String key : properties.stringPropertyNames())
+			out.writeUTF(properties.getProperty(key));
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/system/LinuxSecureRandomProvider.java

@@ -0,0 +1,69 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.security.Provider;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Logger;
+
+import javax.annotation.concurrent.Immutable;
+
+import static java.util.logging.Level.WARNING;
+
+@Immutable
+@NotNullByDefault
+class LinuxSecureRandomProvider extends AbstractSecureRandomProvider {
+
+	private static final Logger LOG =
+			Logger.getLogger(LinuxSecureRandomProvider.class.getName());
+
+	private static final File RANDOM_DEVICE = new File("/dev/urandom");
+
+	private final AtomicBoolean seeded = new AtomicBoolean(false);
+	private final File outputDevice;
+
+	LinuxSecureRandomProvider() {
+		this(RANDOM_DEVICE);
+	}
+
+	LinuxSecureRandomProvider(File outputDevice) {
+		this.outputDevice = outputDevice;
+	}
+
+	@Override
+	public Provider getProvider() {
+		if (!seeded.getAndSet(true)) writeSeed();
+		return new LinuxProvider();
+	}
+
+	protected void writeSeed() {
+		try {
+			DataOutputStream out = new DataOutputStream(
+					new FileOutputStream(outputDevice));
+			writeToEntropyPool(out);
+			out.flush();
+			out.close();
+		} catch (IOException e) {
+			// On some devices /dev/urandom isn't writable - this isn't fatal
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		}
+	}
+
+	// Based on https://android-developers.googleblog.com/2013/08/some-securerandom-thoughts.html
+	private static class LinuxProvider extends Provider {
+
+		private LinuxProvider() {
+			super("LinuxPRNG", 1.1, "A Linux-specific PRNG using /dev/urandom");
+			// Although /dev/urandom is not a SHA-1 PRNG, some callers
+			// explicitly request a SHA1PRNG SecureRandom and we need to
+			// prevent them from getting the default implementation whose
+			// output may have low entropy.
+			put("SecureRandom.SHA1PRNG", LinuxSecureRandomSpi.class.getName());
+			put("SecureRandom.SHA1PRNG ImplementedIn", "Software");
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/system/LinuxSecureRandomSpi.java

@@ -0,0 +1,64 @@
+package org.briarproject.bramble.system;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.security.SecureRandomSpi;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+
+public class LinuxSecureRandomSpi extends SecureRandomSpi {
+
+	private static final Logger LOG =
+			Logger.getLogger(LinuxSecureRandomSpi.class.getName());
+
+	private static final File RANDOM_DEVICE = new File("/dev/urandom");
+
+	private final File inputDevice, outputDevice;
+
+	public LinuxSecureRandomSpi() {
+		this(RANDOM_DEVICE, RANDOM_DEVICE);
+	}
+
+	LinuxSecureRandomSpi(File inputDevice, File outputDevice) {
+		this.inputDevice = inputDevice;
+		this.outputDevice = outputDevice;
+	}
+
+	@Override
+	protected void engineSetSeed(byte[] seed) {
+		try {
+			DataOutputStream out = new DataOutputStream(
+					new FileOutputStream(outputDevice));
+			out.write(seed);
+			out.flush();
+			out.close();
+		} catch (IOException e) {
+			// On some devices /dev/urandom isn't writable - this isn't fatal
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		}
+	}
+
+	@Override
+	protected void engineNextBytes(byte[] bytes) {
+		try {
+			DataInputStream in = new DataInputStream(
+					new FileInputStream(inputDevice));
+			in.readFully(bytes);
+			in.close();
+		} catch (IOException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+	@Override
+	protected byte[] engineGenerateSeed(int len) {
+		byte[] seed = new byte[len];
+		engineNextBytes(seed);
+		return seed;
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/system/LinuxSeedProvider.java

@@ -1,75 +0,0 @@
-package org.briarproject.bramble.system;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.SeedProvider;
-
-import java.io.DataInputStream;
-import java.io.DataOutputStream;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.net.InetAddress;
-import java.net.NetworkInterface;
-import java.util.Collections;
-import java.util.List;
-import java.util.logging.Logger;
-
-import javax.annotation.concurrent.Immutable;
-
-import static java.util.logging.Level.WARNING;
-
-@Immutable
-@NotNullByDefault
-class LinuxSeedProvider implements SeedProvider {
-
-	private static final Logger LOG =
-			Logger.getLogger(LinuxSeedProvider.class.getName());
-
-	private final String outputFile, inputFile;
-
-	LinuxSeedProvider() {
-		this("/dev/urandom", "/dev/urandom");
-	}
-
-	LinuxSeedProvider(String outputFile, String inputFile) {
-		this.outputFile = outputFile;
-		this.inputFile = inputFile;
-	}
-
-	@Override
-	public byte[] getSeed() {
-		byte[] seed = new byte[SEED_BYTES];
-		// Contribute whatever slightly unpredictable info we have to the pool
-		try {
-			DataOutputStream out = new DataOutputStream(
-					new FileOutputStream(outputFile));
-			writeToEntropyPool(out);
-			out.flush();
-			out.close();
-		} catch (IOException e) {
-			// On some devices /dev/urandom isn't writable - this isn't fatal
-			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
-		}
-		// Read the seed from the pool
-		try {
-			DataInputStream in = new DataInputStream(
-					new FileInputStream(inputFile));
-			in.readFully(seed);
-			in.close();
-		} catch (IOException e) {
-			throw new RuntimeException(e);
-		}
-		return seed;
-	}
-
-	void writeToEntropyPool(DataOutputStream out) throws IOException {
-		out.writeLong(System.currentTimeMillis());
-		out.writeLong(System.nanoTime());
-		List<NetworkInterface> ifaces =
-				Collections.list(NetworkInterface.getNetworkInterfaces());
-		for (NetworkInterface i : ifaces) {
-			List<InetAddress> addrs = Collections.list(i.getInetAddresses());
-			for (InetAddress a : addrs) out.write(a.getAddress());
-		}
-	}
-}

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

@@ -0,0 +1,142 @@
+package org.briarproject.bramble;
+
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.Vector;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.Executor;
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+public class PoliteExecutorTest extends BrambleTestCase {
+
+	private static final String TAG = "Test";
+	private static final int TASKS = 10;
+
+	@Test
+	public void testTasksAreDelegatedInOrderOfSubmission() throws Exception {
+		// Delegate to a single-threaded executor
+		Executor delegate = Executors.newSingleThreadExecutor();
+		// Allow all the tasks to be delegated straight away
+		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, TASKS * 2);
+		final List<Integer> list = new Vector<Integer>();
+		final CountDownLatch latch = new CountDownLatch(TASKS);
+		for (int i = 0; i < TASKS; i++) {
+			final int result = i;
+			polite.execute(new Runnable() {
+				@Override
+				public void run() {
+					list.add(result);
+					latch.countDown();
+				}
+			});
+		}
+		// Wait for all the tasks to finish
+		latch.await();
+		// The tasks should have run in the order they were submitted
+		assertEquals(ascendingOrder(), list);
+	}
+
+	@Test
+	public void testQueuedTasksAreDelegatedInOrderOfSubmission()
+			throws Exception {
+		// Delegate to a single-threaded executor
+		Executor delegate = Executors.newSingleThreadExecutor();
+		// Allow two tasks to be delegated at a time
+		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, 2);
+		final List<Integer> list = new Vector<Integer>();
+		final CountDownLatch latch = new CountDownLatch(TASKS);
+		for (int i = 0; i < TASKS; i++) {
+			final int result = i;
+			polite.execute(new Runnable() {
+				@Override
+				public void run() {
+					list.add(result);
+					latch.countDown();
+				}
+			});
+		}
+		// Wait for all the tasks to finish
+		latch.await();
+		// The tasks should have run in the order they were submitted
+		assertEquals(ascendingOrder(), list);
+	}
+
+	@Test
+	public void testTasksRunInParallelOnDelegate() throws Exception {
+		// Delegate to a multi-threaded executor
+		Executor delegate = Executors.newCachedThreadPool();
+		// Allow all the tasks to be delegated straight away
+		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, TASKS * 2);
+		final List<Integer> list = new Vector<Integer>();
+		final CountDownLatch[] latches = new CountDownLatch[TASKS];
+		for (int i = 0; i < TASKS; i++) latches[i] = new CountDownLatch(1);
+		for (int i = 0; i < TASKS; i++) {
+			final int result = i;
+			polite.execute(new Runnable() {
+				@Override
+				public void run() {
+					try {
+						// Each task waits for the next task, if any, to finish
+						if (result < TASKS - 1) latches[result + 1].await();
+						list.add(result);
+					} catch (InterruptedException e) {
+						fail();
+					}
+					latches[result].countDown();
+				}
+			});
+		}
+		// Wait for all the tasks to finish
+		for (int i = 0; i < TASKS; i++) latches[i].await();
+		// The tasks should have finished in reverse order
+		assertEquals(descendingOrder(), list);
+	}
+
+	@Test
+	public void testTasksDoNotRunInParallelOnDelegate() throws Exception {
+		// Delegate to a multi-threaded executor
+		Executor delegate = Executors.newCachedThreadPool();
+		// Allow one task to be delegated at a time
+		PoliteExecutor polite = new PoliteExecutor(TAG, delegate, 1);
+		final List<Integer> list = new Vector<Integer>();
+		final CountDownLatch latch = new CountDownLatch(TASKS);
+		for (int i = 0; i < TASKS; i++) {
+			final int result = i;
+			polite.execute(new Runnable() {
+				@Override
+				public void run() {
+					try {
+						// Each task runs faster than the previous task
+						Thread.sleep(TASKS - result);
+						list.add(result);
+					} catch (InterruptedException e) {
+						fail();
+					}
+					latch.countDown();
+				}
+			});
+		}
+		// Wait for all the tasks to finish
+		latch.await();
+		// The tasks should have finished in the order they were submitted
+		assertEquals(ascendingOrder(), list);
+	}
+
+	private List<Integer> ascendingOrder() {
+		Integer[] array = new Integer[TASKS];
+		for (int i = 0; i < TASKS; i++) array[i] = i;
+		return Arrays.asList(array);
+	}
+
+	private List<Integer> descendingOrder() {
+		Integer[] array = new Integer[TASKS];
+		for (int i = 0; i < TASKS; i++) array[i] = TASKS - 1 - i;
+		return Arrays.asList(array);
+	}
+}

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

@@ -45,7 +45,7 @@ public class EllipticCurveMultiplicationTest extends BrambleTestCase {
 		byte[] seed = new byte[32];
 		new SecureRandom().nextBytes(seed);
 		// Montgomery ladder multiplier
-		SecureRandom random = new FortunaSecureRandom(seed);
+		SecureRandom random = new PseudoSecureRandom(seed);
 		ECKeyGenerationParameters montgomeryGeneratorParams =
 				new ECKeyGenerationParameters(PARAMETERS, random);
 		ECKeyPairGenerator montgomeryGenerator = new ECKeyPairGenerator();
@@ -63,7 +63,7 @@ public class EllipticCurveMultiplicationTest extends BrambleTestCase {
 		ECPublicKeyParameters montgomeryPublic2 =
 				(ECPublicKeyParameters) montgomeryKeyPair2.getPublic();
 		// Default multiplier
-		random = new FortunaSecureRandom(seed);
+		random = new PseudoSecureRandom(seed);
 		ECKeyGenerationParameters defaultGeneratorParams =
 				new ECKeyGenerationParameters(defaultParameters, random);
 		ECKeyPairGenerator defaultGenerator = new ECKeyPairGenerator();

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

@@ -1,99 +0,0 @@
-package org.briarproject.bramble.crypto;
-
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.junit.Test;
-import org.spongycastle.crypto.BlockCipher;
-import org.spongycastle.crypto.engines.AESLightEngine;
-import org.spongycastle.crypto.params.KeyParameter;
-
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertEquals;
-
-public class FortunaGeneratorTest extends BrambleTestCase {
-
-	@Test
-	public void testCounterInitialisedToOne() {
-		FortunaGenerator f = new FortunaGenerator(new byte[32]);
-		// The counter is little-endian
-		byte[] expected = new byte[16];
-		expected[0] = 1;
-		assertArrayEquals(expected, f.getCounter());
-	}
-
-	@Test
-	public void testIncrementCounter() {
-		FortunaGenerator f = new FortunaGenerator(new byte[32]);
-		// Increment the counter until it reaches 255
-		for (int i = 1; i < 255; i++) f.incrementCounter();
-		byte[] expected = new byte[16];
-		expected[0] = (byte) 255;
-		assertArrayEquals(expected, f.getCounter());
-		// Increment the counter again - it should carry into the next byte
-		f.incrementCounter();
-		expected[0] = 0;
-		expected[1] = 1;
-		assertArrayEquals(expected, f.getCounter());
-		// Increment the counter until it carries into the next byte
-		for (int i = 256; i < 65536; i++) f.incrementCounter();
-		expected[0] = 0;
-		expected[1] = 0;
-		expected[2] = 1;
-		assertArrayEquals(expected, f.getCounter());
-	}
-
-	@Test
-	public void testNextBytes() {
-		// Generate several outputs with the same seed - they should all match
-		byte[] seed = new byte[32];
-		byte[] out1 = new byte[48];
-		new FortunaGenerator(seed).nextBytes(out1, 0, 48);
-		// One byte longer than a block, with an offset of one
-		byte[] out2 = new byte[49];
-		new FortunaGenerator(seed).nextBytes(out2, 1, 48);
-		for (int i = 0; i < 48; i++) assertEquals(out1[i], out2[i + 1]);
-		// One byte shorter than a block
-		byte[] out3 = new byte[47];
-		new FortunaGenerator(seed).nextBytes(out3, 0, 47);
-		for (int i = 0; i < 47; i++) assertEquals(out1[i], out3[i]);
-		// Less than a block, with an offset greater than a block
-		byte[] out4 = new byte[32];
-		new FortunaGenerator(seed).nextBytes(out4, 17, 15);
-		for (int i = 0; i < 15; i++) assertEquals(out1[i], out4[i + 17]);
-	}
-
-	@Test
-	public void testRekeying() {
-		byte[] seed = new byte[32];
-		FortunaGenerator f = new FortunaGenerator(seed);
-		// Generate three blocks of output
-		byte[] out1 = new byte[48];
-		f.nextBytes(out1, 0, 48);
-		// Create another generator with the same seed and generate one block
-		f = new FortunaGenerator(seed);
-		byte[] out2 = new byte[16];
-		f.nextBytes(out2, 0, 16);
-		// The generator should have rekeyed with the 2nd and 3rd blocks
-		byte[] expectedKey = new byte[32];
-		System.arraycopy(out1, 16, expectedKey, 0, 32);
-		// The generator's counter should have been incremented 3 times
-		byte[] expectedCounter = new byte[16];
-		expectedCounter[0] = 4;
-		// The next expected output block is the counter encrypted with the key
-		byte[] expectedOutput = new byte[16];
-		BlockCipher c = new AESLightEngine();
-		c.init(true, new KeyParameter(expectedKey));
-		c.processBlock(expectedCounter, 0, expectedOutput, 0);
-		// Check that the generator produces the expected output block
-		byte[] out3 = new byte[16];
-		f.nextBytes(out3, 0, 16);
-		assertArrayEquals(expectedOutput, out3);
-	}
-
-	@Test
-	public void testMaximumRequestLength() {
-		int expectedMax = 1024 * 1024;
-		byte[] output = new byte[expectedMax + 123];
-		FortunaGenerator f = new FortunaGenerator(new byte[32]);
-		assertEquals(expectedMax, f.nextBytes(output, 0, output.length));
-	}
-}

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

@@ -1,67 +0,0 @@
-package org.briarproject.bramble.crypto;
-
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.junit.Test;
-import org.spongycastle.crypto.BlockCipher;
-import org.spongycastle.crypto.digests.SHA256Digest;
-import org.spongycastle.crypto.engines.AESLightEngine;
-import org.spongycastle.crypto.params.KeyParameter;
-
-import static org.briarproject.bramble.crypto.FortunaSecureRandom.SELF_TEST_VECTOR_1;
-import static org.briarproject.bramble.crypto.FortunaSecureRandom.SELF_TEST_VECTOR_2;
-import static org.briarproject.bramble.crypto.FortunaSecureRandom.SELF_TEST_VECTOR_3;
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertTrue;
-
-public class FortunaSecureRandomTest extends BrambleTestCase {
-
-	@Test
-	public void testClassPassesSelfTest() {
-		assertTrue(FortunaSecureRandom.selfTest());
-	}
-
-	@Test
-	public void testSelfTestVectorsAreReproducible() {
-		byte[] key = new byte[32], seed = new byte[32];
-		byte[] counter = new byte[16], output = new byte[16];
-		byte[] newKey = new byte[32];
-		// Calculate the initial key
-		DoubleDigest digest = new DoubleDigest(new SHA256Digest());
-		digest.update(key);
-		digest.update(seed);
-		digest.digest(key, 0, 32);
-		// Calculate the first output block and the new key
-		BlockCipher c = new AESLightEngine();
-		c.init(true, new KeyParameter(key));
-		counter[0] = 1;
-		c.processBlock(counter, 0, output, 0);
-		counter[0] = 2;
-		c.processBlock(counter, 0, newKey, 0);
-		counter[0] = 3;
-		c.processBlock(counter, 0, newKey, 16);
-		System.arraycopy(newKey, 0, key, 0, 32);
-		// The first self-test vector should match the first output block
-		assertArrayEquals(SELF_TEST_VECTOR_1, output);
-		// Calculate the second output block and the new key before reseeding
-		c.init(true, new KeyParameter(key));
-		counter[0] = 4;
-		c.processBlock(counter, 0, output, 0);
-		counter[0] = 5;
-		c.processBlock(counter, 0, newKey, 0);
-		counter[0] = 6;
-		c.processBlock(counter, 0, newKey, 16);
-		System.arraycopy(newKey, 0, key, 0, 32);
-		// The second self-test vector should match the second output block
-		assertArrayEquals(SELF_TEST_VECTOR_2, output);
-		// Calculate the new key after reseeding
-		digest.update(key);
-		digest.update(seed);
-		digest.digest(key, 0, 32);
-		// Calculate the third output block
-		c.init(true, new KeyParameter(key));
-		counter[0] = 8;
-		c.processBlock(counter, 0, output, 0);
-		// The third self-test vector should match the third output block
-		assertArrayEquals(SELF_TEST_VECTOR_3, output);
-	}
-}

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

@@ -2,7 +2,7 @@ package org.briarproject.bramble.crypto;
 
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSeedProvider;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
 import org.briarproject.bramble.test.TestUtils;
 import org.junit.Test;
 
@@ -21,7 +21,7 @@ public class HashTest extends BrambleTestCase {
 	private final byte[] inputBytes2 = new byte[0];
 
 	public HashTest() {
-		crypto = new CryptoComponentImpl(new TestSeedProvider());
+		crypto = new CryptoComponentImpl(new TestSecureRandomProvider());
 	}
 
 	@Test

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

@@ -3,9 +3,9 @@ package org.briarproject.bramble.crypto;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.api.system.SeedProvider;
+import org.briarproject.bramble.api.system.SecureRandomProvider;
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSeedProvider;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
 import org.junit.Test;
 
 import static org.junit.Assert.assertArrayEquals;
@@ -14,8 +14,9 @@ public class KeyAgreementTest extends BrambleTestCase {
 
 	@Test
 	public void testDeriveMasterSecret() throws Exception {
-		SeedProvider seedProvider = new TestSeedProvider();
-		CryptoComponent crypto = new CryptoComponentImpl(seedProvider);
+		SecureRandomProvider
+				secureRandomProvider = new TestSecureRandomProvider();
+		CryptoComponent crypto = new CryptoComponentImpl(secureRandomProvider);
 		KeyPair aPair = crypto.generateAgreementKeyPair();
 		byte[] aPub = aPair.getPublic().getEncoded();
 		KeyPair bPair = crypto.generateAgreementKeyPair();
@@ -27,8 +28,9 @@ public class KeyAgreementTest extends BrambleTestCase {
 
 	@Test
 	public void testDeriveSharedSecret() throws Exception {
-		SeedProvider seedProvider = new TestSeedProvider();
-		CryptoComponent crypto = new CryptoComponentImpl(seedProvider);
+		SecureRandomProvider
+				secureRandomProvider = new TestSecureRandomProvider();
+		CryptoComponent crypto = new CryptoComponentImpl(secureRandomProvider);
 		KeyPair aPair = crypto.generateAgreementKeyPair();
 		byte[] aPub = aPair.getPublic().getEncoded();
 		KeyPair bPair = crypto.generateAgreementKeyPair();

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

@@ -1,20 +1,24 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.api.Bytes;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSeedProvider;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
 import org.briarproject.bramble.test.TestUtils;
 import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 public class KeyDerivationTest extends BrambleTestCase {
 
@@ -23,7 +27,7 @@ public class KeyDerivationTest extends BrambleTestCase {
 	private final SecretKey master;
 
 	public KeyDerivationTest() {
-		crypto = new CryptoComponentImpl(new TestSeedProvider());
+		crypto = new CryptoComponentImpl(new TestSecureRandomProvider());
 		master = TestUtils.getSecretKey();
 	}
 
@@ -156,11 +160,7 @@ public class KeyDerivationTest extends BrambleTestCase {
 	}
 
 	private void assertAllDifferent(List<SecretKey> keys) {
-		for (SecretKey ki : keys) {
-			for (SecretKey kj : keys) {
-				if (ki == kj) assertArrayEquals(ki.getBytes(), kj.getBytes());
-				else assertFalse(Arrays.equals(ki.getBytes(), kj.getBytes()));
-			}
-		}
+		Set<Bytes> set = new HashSet<Bytes>();
+		for (SecretKey k : keys) assertTrue(set.add(new Bytes(k.getBytes())));
 	}
 }

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

@@ -5,7 +5,7 @@ import org.briarproject.bramble.api.crypto.KeyParser;
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSeedProvider;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
 import org.briarproject.bramble.test.TestUtils;
 import org.junit.Test;
 
@@ -19,7 +19,7 @@ import static org.junit.Assert.assertTrue;
 public class KeyEncodingAndParsingTest extends BrambleTestCase {
 
 	private final CryptoComponentImpl crypto =
-			new CryptoComponentImpl(new TestSeedProvider());
+			new CryptoComponentImpl(new TestSecureRandomProvider());
 
 	@Test
 	public void testAgreementPublicKeyLength() throws Exception {

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

@@ -3,7 +3,7 @@ package org.briarproject.bramble.crypto;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSeedProvider;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
 import org.briarproject.bramble.test.TestUtils;
 import org.junit.Test;
 
@@ -22,7 +22,7 @@ public class MacTest extends BrambleTestCase {
 	private final byte[] inputBytes2 = new byte[0];
 
 	public MacTest() {
-		crypto = new CryptoComponentImpl(new TestSeedProvider());
+		crypto = new CryptoComponentImpl(new TestSecureRandomProvider());
 	}
 
 	@Test

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

@@ -1,7 +1,7 @@
 package org.briarproject.bramble.crypto;
 
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSeedProvider;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
 import org.briarproject.bramble.test.TestUtils;
 import org.junit.Test;
 
@@ -15,7 +15,7 @@ import static org.junit.Assert.assertTrue;
 public class PasswordBasedKdfTest extends BrambleTestCase {
 
 	private final CryptoComponentImpl crypto =
-			new CryptoComponentImpl(new TestSeedProvider());
+			new CryptoComponentImpl(new TestSecureRandomProvider());
 
 	@Test
 	public void testEncryptionAndDecryption() {

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

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.junit.Test;
 
+import static org.briarproject.bramble.api.crypto.PasswordStrengthEstimator.NONE;
 import static org.briarproject.bramble.api.crypto.PasswordStrengthEstimator.QUITE_STRONG;
 import static org.junit.Assert.assertTrue;
 
@@ -12,7 +13,7 @@ public class PasswordStrengthEstimatorImplTest extends BrambleTestCase {
 	@Test
 	public void testWeakPasswords() {
 		PasswordStrengthEstimator e = new PasswordStrengthEstimatorImpl();
-		assertTrue(e.estimateStrength("") < QUITE_STRONG);
+		assertTrue(e.estimateStrength("") == NONE);
 		assertTrue(e.estimateStrength("password") < QUITE_STRONG);
 		assertTrue(e.estimateStrength("letmein") < QUITE_STRONG);
 		assertTrue(e.estimateStrength("123456") < QUITE_STRONG);

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

@@ -0,0 +1,48 @@
+package org.briarproject.bramble.crypto;
+
+import org.briarproject.bramble.api.crypto.PseudoRandom;
+
+import java.security.Provider;
+import java.security.SecureRandom;
+import java.security.SecureRandomSpi;
+
+class PseudoSecureRandom extends SecureRandom {
+
+	private static final Provider PROVIDER = new PseudoSecureRandomProvider();
+
+	PseudoSecureRandom(byte[] seed) {
+		super(new PseudoSecureRandomSpi(seed), PROVIDER);
+	}
+
+	private static class PseudoSecureRandomSpi extends SecureRandomSpi {
+
+		private final PseudoRandom pseudoRandom;
+
+		private PseudoSecureRandomSpi(byte[] seed) {
+			pseudoRandom = new PseudoRandomImpl(seed);
+		}
+
+		@Override
+		protected byte[] engineGenerateSeed(int length) {
+			return pseudoRandom.nextBytes(length);
+		}
+
+		@Override
+		protected void engineNextBytes(byte[] b) {
+			byte[] random = pseudoRandom.nextBytes(b.length);
+			System.arraycopy(random, 0, b, 0, b.length);
+		}
+
+		@Override
+		protected void engineSetSeed(byte[] seed) {
+			// Thank you for your input
+		}
+	}
+
+	private static class PseudoSecureRandomProvider extends Provider {
+
+		private PseudoSecureRandomProvider() {
+			super("PseudoSecureRandom", 1.0, "Only for testing");
+		}
+	}
+}

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

@@ -3,7 +3,7 @@ package org.briarproject.bramble.crypto;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestSeedProvider;
+import org.briarproject.bramble.test.TestSecureRandomProvider;
 import org.briarproject.bramble.test.TestUtils;
 import org.junit.Test;
 
@@ -22,7 +22,7 @@ public class SignatureTest extends BrambleTestCase {
 	private final byte[] inputBytes = TestUtils.getRandomBytes(123);
 
 	public SignatureTest() {
-		crypto = new CryptoComponentImpl(new TestSeedProvider());
+		crypto = new CryptoComponentImpl(new TestSecureRandomProvider());
 		KeyPair k = crypto.generateSignatureKeyPair();
 		publicKey = k.getPublic().getEncoded();
 		privateKey = k.getPrivate().getEncoded();

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

@@ -9,9 +9,13 @@ import java.io.ByteArrayOutputStream;
 
 import static org.briarproject.bramble.api.transport.TransportConstants.FRAME_HEADER_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.MAC_LENGTH;
+import static org.briarproject.bramble.api.transport.TransportConstants.MAX_FRAME_LENGTH;
+import static org.briarproject.bramble.api.transport.TransportConstants.MAX_PAYLOAD_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_IV_LENGTH;
+import static org.briarproject.bramble.api.transport.TransportConstants.STREAM_HEADER_LENGTH;
 import static org.briarproject.bramble.api.transport.TransportConstants.TAG_LENGTH;
 import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
 
 public class StreamEncrypterImplTest extends BrambleTestCase {
 
@@ -30,6 +34,58 @@ public class StreamEncrypterImplTest extends BrambleTestCase {
 		payload = TestUtils.getRandomBytes(payloadLength);
 	}
 
+	@Test(expected = IllegalArgumentException.class)
+	public void testRejectsNegativePayloadLength() throws Exception {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
+
+		s.writeFrame(payload, -1, 0, false);
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void testRejectsNegativePaddingLength() throws Exception {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
+
+		s.writeFrame(payload, 0, -1, false);
+	}
+
+	@Test(expected = IllegalArgumentException.class)
+	public void testRejectsMaxPayloadPlusPadding() throws Exception {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
+
+		byte[] bigPayload = new byte[MAX_PAYLOAD_LENGTH + 1];
+		s.writeFrame(bigPayload, MAX_PAYLOAD_LENGTH, 1, false);
+	}
+
+	@Test
+	public void testAcceptsMaxPayloadIncludingPadding() throws Exception {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
+
+		byte[] bigPayload = new byte[MAX_PAYLOAD_LENGTH];
+		s.writeFrame(bigPayload, MAX_PAYLOAD_LENGTH - 1, 1, false);
+		assertEquals(TAG_LENGTH + STREAM_HEADER_LENGTH + MAX_FRAME_LENGTH,
+				out.size());
+	}
+
+	@Test
+	public void testAcceptsMaxPayloadWithoutPadding() throws Exception {
+		ByteArrayOutputStream out = new ByteArrayOutputStream();
+		StreamEncrypterImpl s = new StreamEncrypterImpl(out, cipher,
+				streamNumber, tag, streamHeaderIv, streamHeaderKey, frameKey);
+
+		byte[] bigPayload = new byte[MAX_PAYLOAD_LENGTH];
+		s.writeFrame(bigPayload, MAX_PAYLOAD_LENGTH, 0, false);
+		assertEquals(TAG_LENGTH + STREAM_HEADER_LENGTH + MAX_FRAME_LENGTH,
+				out.size());
+	}
+
 	@Test
 	public void testWriteUnpaddedNonFinalFrameWithTag() throws Exception {
 		ByteArrayOutputStream out = new ByteArrayOutputStream();

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

@@ -1,14 +0,0 @@
-package org.briarproject.bramble.properties;
-
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.junit.Test;
-
-import static org.junit.Assert.fail;
-
-public class TransportPropertyManagerImplTest extends BrambleTestCase {
-
-	@Test
-	public void testUnitTestsExist() {
-		fail(); // FIXME: Write tests
-	}
-}

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

@@ -19,12 +19,12 @@ import org.briarproject.bramble.api.sync.ValidationManager.IncomingMessageHook;
 import org.briarproject.bramble.api.sync.ValidationManager.MessageValidator;
 import org.briarproject.bramble.api.sync.ValidationManager.State;
 import org.briarproject.bramble.api.sync.event.MessageAddedEvent;
-import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.ImmediateExecutor;
 import org.briarproject.bramble.test.TestUtils;
 import org.briarproject.bramble.util.ByteUtils;
 import org.jmock.Expectations;
-import org.jmock.Mockery;
+import org.junit.Before;
 import org.junit.Test;
 
 import java.util.Arrays;
@@ -38,8 +38,18 @@ import static org.briarproject.bramble.api.sync.ValidationManager.State.INVALID;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.PENDING;
 import static org.briarproject.bramble.api.sync.ValidationManager.State.UNKNOWN;
 
-public class ValidationManagerImplTest extends BrambleTestCase {
+public class ValidationManagerImplTest extends BrambleMockTestCase {
 
+	private final DatabaseComponent db = context.mock(DatabaseComponent.class);
+	private final MessageFactory messageFactory =
+			context.mock(MessageFactory.class);
+	private final MessageValidator validator =
+			context.mock(MessageValidator.class);
+	private final IncomingMessageHook hook =
+			context.mock(IncomingMessageHook.class);
+
+	private final Executor dbExecutor = new ImmediateExecutor();
+	private final Executor validationExecutor = new ImmediateExecutor();
 	private final ClientId clientId =
 			new ClientId(TestUtils.getRandomString(5));
 	private final MessageId messageId = new MessageId(TestUtils.getRandomId());
@@ -63,23 +73,58 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 	private final MessageContext validResultWithDependencies =
 			new MessageContext(metadata, Collections.singletonList(messageId1));
 
+	private ValidationManagerImpl vm;
+
 	public ValidationManagerImplTest() {
 		// Encode the messages
 		System.arraycopy(groupId.getBytes(), 0, raw, 0, UniqueId.LENGTH);
 		ByteUtils.writeUint64(timestamp, raw, UniqueId.LENGTH);
 	}
 
+	@Before
+	public void setUp() {
+		vm = new ValidationManagerImpl(db, dbExecutor, validationExecutor,
+				messageFactory);
+		vm.registerMessageValidator(clientId, validator);
+		vm.registerIncomingMessageHook(clientId, hook);
+	}
+
+	@Test
+	public void testStartAndStop() throws Exception {
+		final Transaction txn = new Transaction(null, true);
+		final Transaction txn1 = new Transaction(null, true);
+		final Transaction txn2 = new Transaction(null, true);
+
+		context.checking(new Expectations() {{
+			// validateOutstandingMessages()
+			oneOf(db).startTransaction(true);
+			will(returnValue(txn));
+			oneOf(db).getMessagesToValidate(txn, clientId);
+			will(returnValue(Collections.emptyList()));
+			oneOf(db).commitTransaction(txn);
+			oneOf(db).endTransaction(txn);
+			// deliverOutstandingMessages()
+			oneOf(db).startTransaction(true);
+			will(returnValue(txn1));
+			oneOf(db).getPendingMessages(txn1, clientId);
+			will(returnValue(Collections.emptyList()));
+			oneOf(db).commitTransaction(txn1);
+			oneOf(db).endTransaction(txn1);
+			// shareOutstandingMessages()
+			oneOf(db).startTransaction(true);
+			will(returnValue(txn2));
+			oneOf(db).getMessagesToShare(txn2, clientId);
+			will(returnValue(Collections.emptyList()));
+			oneOf(db).commitTransaction(txn2);
+			oneOf(db).endTransaction(txn2);
+		}});
+
+		vm.startService();
+		vm.stopService();
+	}
+
 	@Test
 	public void testMessagesAreValidatedAtStartup() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, false);
@@ -87,6 +132,7 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 		final Transaction txn4 = new Transaction(null, false);
 		final Transaction txn5 = new Transaction(null, true);
 		final Transaction txn6 = new Transaction(null, true);
+
 		context.checking(new Expectations() {{
 			// Get messages to validate
 			oneOf(db).startTransaction(true);
@@ -165,26 +211,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn6);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testPendingMessagesAreDeliveredAtStartup() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, false);
@@ -266,26 +297,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn4);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testMessagesAreSharedAtStartup() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, true);
@@ -333,29 +349,15 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn4);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testIncomingMessagesAreShared() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
 		final Transaction txn2 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -396,33 +398,19 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn2);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testValidationContinuesAfterNoSuchMessageException()
 			throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, true);
 		final Transaction txn3 = new Transaction(null, false);
 		final Transaction txn4 = new Transaction(null, true);
 		final Transaction txn5 = new Transaction(null, true);
+
 		context.checking(new Expectations() {{
 			// Get messages to validate
 			oneOf(db).startTransaction(true);
@@ -481,33 +469,19 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn5);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testValidationContinuesAfterNoSuchGroupException()
 			throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, true);
 		final Transaction txn2 = new Transaction(null, true);
 		final Transaction txn3 = new Transaction(null, false);
 		final Transaction txn4 = new Transaction(null, true);
 		final Transaction txn5 = new Transaction(null, true);
+
 		context.checking(new Expectations() {{
 			// Get messages to validate
 			oneOf(db).startTransaction(true);
@@ -571,28 +545,14 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn5);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.startService();
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testNonLocalMessagesAreValidatedWhenAdded() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -619,51 +579,20 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn1);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testLocalMessagesAreNotValidatedWhenAdded() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
-
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, null));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testMessagesWithUndeliveredDependenciesArePending()
 			throws Exception {
-
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -688,29 +617,15 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn1);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testMessagesWithDeliveredDependenciesGetDelivered()
 			throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -741,30 +656,16 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn1);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testMessagesWithInvalidDependenciesAreInvalid()
 			throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
 		final Transaction txn2 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -809,26 +710,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn2);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testRecursiveInvalidation() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final MessageId messageId3 = new MessageId(TestUtils.getRandomId());
 		final MessageId messageId4 = new MessageId(TestUtils.getRandomId());
 		final Map<MessageId, State> twoDependents =
@@ -842,6 +728,7 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 		final Transaction txn4 = new Transaction(null, false);
 		final Transaction txn5 = new Transaction(null, false);
 		final Transaction txn6 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -927,26 +814,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn6);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testPendingDependentsGetDelivered() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final MessageId messageId3 = new MessageId(TestUtils.getRandomId());
 		final MessageId messageId4 = new MessageId(TestUtils.getRandomId());
 		final Message message3 = new Message(messageId3, groupId, timestamp,
@@ -968,6 +840,7 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 		final Transaction txn4 = new Transaction(null, false);
 		final Transaction txn5 = new Transaction(null, false);
 		final Transaction txn6 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -1100,26 +973,11 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn6);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
 
 	@Test
 	public void testOnlyReadyPendingDependentsGetDelivered() throws Exception {
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
 		final Map<MessageId, State> twoDependencies =
 				new LinkedHashMap<MessageId, State>();
 		twoDependencies.put(messageId, DELIVERED);
@@ -1127,6 +985,7 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 		final Transaction txn = new Transaction(null, true);
 		final Transaction txn1 = new Transaction(null, false);
 		final Transaction txn2 = new Transaction(null, false);
+
 		context.checking(new Expectations() {{
 			// Load the group
 			oneOf(db).startTransaction(true);
@@ -1162,86 +1021,6 @@ public class ValidationManagerImplTest extends BrambleTestCase {
 			oneOf(db).endTransaction(txn2);
 		}});
 
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-
-		context.assertIsSatisfied();
 	}
-
-	@Test
-	public void testMessageDependencyCycle() throws Exception {
-		final MessageContext cycleContext = new MessageContext(metadata,
-				Collections.singletonList(messageId));
-
-		Mockery context = new Mockery();
-		final DatabaseComponent db = context.mock(DatabaseComponent.class);
-		final Executor dbExecutor = new ImmediateExecutor();
-		final Executor cryptoExecutor = new ImmediateExecutor();
-		final MessageFactory messageFactory =
-				context.mock(MessageFactory.class);
-		final MessageValidator validator = context.mock(MessageValidator.class);
-		final IncomingMessageHook hook =
-				context.mock(IncomingMessageHook.class);
-		final Transaction txn = new Transaction(null, true);
-		final Transaction txn1 = new Transaction(null, false);
-		final Transaction txn2 = new Transaction(null, true);
-		final Transaction txn3 = new Transaction(null, false);
-		context.checking(new Expectations() {{
-			// Load the group
-			oneOf(db).startTransaction(true);
-			will(returnValue(txn));
-			oneOf(db).getGroup(txn, groupId);
-			will(returnValue(group));
-			oneOf(db).commitTransaction(txn);
-			oneOf(db).endTransaction(txn);
-			// Validate the message: valid
-			oneOf(validator).validateMessage(message, group);
-			will(returnValue(validResultWithDependencies));
-			// Store the validation result
-			oneOf(db).startTransaction(false);
-			will(returnValue(txn1));
-			oneOf(db).addMessageDependencies(txn1, message,
-					validResultWithDependencies.getDependencies());
-			oneOf(db).getMessageDependencies(txn1, messageId);
-			will(returnValue(Collections.singletonMap(messageId1, UNKNOWN)));
-			oneOf(db).mergeMessageMetadata(txn1, messageId, metadata);
-			oneOf(db).setMessageState(txn1, messageId, PENDING);
-			oneOf(db).commitTransaction(txn1);
-			oneOf(db).endTransaction(txn1);
-			// Second message is coming in
-			oneOf(db).startTransaction(true);
-			will(returnValue(txn2));
-			oneOf(db).getGroup(txn2, groupId);
-			will(returnValue(group));
-			oneOf(db).commitTransaction(txn2);
-			oneOf(db).endTransaction(txn2);
-			// Validate the message: valid
-			oneOf(validator).validateMessage(message1, group);
-			will(returnValue(cycleContext));
-			// Store the validation result
-			oneOf(db).startTransaction(false);
-			will(returnValue(txn3));
-			oneOf(db).addMessageDependencies(txn3, message1,
-					cycleContext.getDependencies());
-			oneOf(db).getMessageDependencies(txn3, messageId1);
-			will(returnValue(Collections.singletonMap(messageId, PENDING)));
-			oneOf(db).mergeMessageMetadata(txn3, messageId1, metadata);
-			oneOf(db).setMessageState(txn3, messageId1, PENDING);
-			oneOf(db).commitTransaction(txn3);
-			oneOf(db).endTransaction(txn3);
-		}});
-
-		ValidationManagerImpl vm = new ValidationManagerImpl(db, dbExecutor,
-				cryptoExecutor, messageFactory);
-		vm.registerMessageValidator(clientId, validator);
-		vm.registerIncomingMessageHook(clientId, hook);
-		vm.eventOccurred(new MessageAddedEvent(message, contactId));
-		vm.eventOccurred(new MessageAddedEvent(message1, contactId));
-
-		context.assertIsSatisfied();
-	}
-
 }

bramble-core/src/test/java/org/briarproject/bramble/system/LinuxSecureRandomProviderTest.java

@@ -0,0 +1,57 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.TestUtils;
+import org.briarproject.bramble.util.OsUtils;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.File;
+import java.security.Provider;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+public class LinuxSecureRandomProviderTest extends BrambleTestCase {
+
+	private final File testDir = TestUtils.getTestDirectory();
+
+	@Before
+	public void setUp() {
+		testDir.mkdirs();
+	}
+
+	@Test
+	public void testGetProviderWritesToRandomDeviceOnFirstCall()
+			throws Exception {
+		if (!(OsUtils.isLinux())) {
+			System.err.println("WARNING: Skipping test, can't run on this OS");
+			return;
+		}
+		// Redirect the provider's output to a file
+		File urandom = new File(testDir, "urandom");
+		urandom.delete();
+		assertTrue(urandom.createNewFile());
+		assertEquals(0, urandom.length());
+		LinuxSecureRandomProvider p = new LinuxSecureRandomProvider(urandom);
+		// Getting a provider should write entropy to the file
+		Provider provider = p.getProvider();
+		assertNotNull(provider);
+		assertEquals("LinuxPRNG", provider.getName());
+		// There should be at least 16 bytes from the clock, 8 from the runtime
+		long length = urandom.length();
+		assertTrue(length >= 24);
+		// Getting another provider should not write to the file again
+		provider = p.getProvider();
+		assertNotNull(provider);
+		assertEquals("LinuxPRNG", provider.getName());
+		assertEquals(length, urandom.length());
+	}
+
+	@After
+	public void tearDown() {
+		TestUtils.deleteTestDirectory(testDir);
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/system/LinuxSecureRandomSpiTest.java

@@ -0,0 +1,128 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.Bytes;
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.bramble.test.TestUtils;
+import org.briarproject.bramble.util.IoUtils;
+import org.briarproject.bramble.util.OsUtils;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.util.HashSet;
+import java.util.Set;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+
+public class LinuxSecureRandomSpiTest extends BrambleTestCase {
+
+	private static final File RANDOM_DEVICE = new File("/dev/urandom");
+	private static final int SEED_BYTES = 32;
+
+	private final File testDir = TestUtils.getTestDirectory();
+
+	@Before
+	public void setUp() {
+		testDir.mkdirs();
+	}
+
+	@Test
+	public void testSeedsAreDistinct() {
+		if (!(OsUtils.isLinux())) {
+			System.err.println("WARNING: Skipping test, can't run on this OS");
+			return;
+		}
+		Set<Bytes> seeds = new HashSet<Bytes>();
+		LinuxSecureRandomSpi engine = new LinuxSecureRandomSpi();
+		for (int i = 0; i < 1000; i++) {
+			byte[] seed = engine.engineGenerateSeed(SEED_BYTES);
+			assertEquals(SEED_BYTES, seed.length);
+			assertTrue(seeds.add(new Bytes(seed)));
+		}
+	}
+
+	@Test
+	public void testEngineSetSeedWritesToRandomDevice() throws Exception {
+		if (!(OsUtils.isLinux())) {
+			System.err.println("WARNING: Skipping test, can't run on this OS");
+			return;
+		}
+		// Redirect the engine's output to a file
+		File urandom = new File(testDir, "urandom");
+		urandom.delete();
+		assertTrue(urandom.createNewFile());
+		assertEquals(0, urandom.length());
+		// Generate a seed
+		byte[] seed = TestUtils.getRandomBytes(SEED_BYTES);
+		// Check that the engine writes the seed to the file
+		LinuxSecureRandomSpi engine = new LinuxSecureRandomSpi(RANDOM_DEVICE,
+				urandom);
+		engine.engineSetSeed(seed);
+		assertEquals(SEED_BYTES, urandom.length());
+		byte[] written = new byte[SEED_BYTES];
+		FileInputStream in = new FileInputStream(urandom);
+		IoUtils.read(in, written);
+		in.close();
+		assertArrayEquals(seed, written);
+	}
+
+	@Test
+	public void testEngineNextBytesReadsFromRandomDevice() throws Exception {
+		if (!(OsUtils.isLinux())) {
+			System.err.println("WARNING: Skipping test, can't run on this OS");
+			return;
+		}
+		// Generate some entropy
+		byte[] entropy = TestUtils.getRandomBytes(SEED_BYTES);
+		// Write the entropy to a file
+		File urandom = new File(testDir, "urandom");
+		urandom.delete();
+		FileOutputStream out = new FileOutputStream(urandom);
+		out.write(entropy);
+		out.flush();
+		out.close();
+		assertTrue(urandom.exists());
+		assertEquals(SEED_BYTES, urandom.length());
+		// Check that the engine reads from the file
+		LinuxSecureRandomSpi engine = new LinuxSecureRandomSpi(urandom,
+				RANDOM_DEVICE);
+		byte[] b = new byte[SEED_BYTES];
+		engine.engineNextBytes(b);
+		assertArrayEquals(entropy, b);
+	}
+
+	@Test
+	public void testEngineGenerateSeedReadsFromRandomDevice() throws Exception {
+		if (!(OsUtils.isLinux())) {
+			System.err.println("WARNING: Skipping test, can't run on this OS");
+			return;
+		}
+		// Generate some entropy
+		byte[] entropy = TestUtils.getRandomBytes(SEED_BYTES);
+		// Write the entropy to a file
+		File urandom = new File(testDir, "urandom");
+		urandom.delete();
+		FileOutputStream out = new FileOutputStream(urandom);
+		out.write(entropy);
+		out.flush();
+		out.close();
+		assertTrue(urandom.exists());
+		assertEquals(SEED_BYTES, urandom.length());
+		// Check that the engine reads from the file
+		LinuxSecureRandomSpi engine = new LinuxSecureRandomSpi(urandom,
+				RANDOM_DEVICE);
+		byte[] b = engine.engineGenerateSeed(SEED_BYTES);
+		assertArrayEquals(entropy, b);
+	}
+
+	@After
+	public void tearDown() {
+		TestUtils.deleteTestDirectory(testDir);
+	}
+}

bramble-core/src/test/java/org/briarproject/bramble/system/LinuxSeedProviderTest.java

@@ -1,90 +0,0 @@
-package org.briarproject.bramble.system;
-
-import org.briarproject.bramble.api.Bytes;
-import org.briarproject.bramble.test.BrambleTestCase;
-import org.briarproject.bramble.test.TestUtils;
-import org.briarproject.bramble.util.OsUtils;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-
-import java.io.File;
-import java.io.FileOutputStream;
-import java.util.HashSet;
-import java.util.Set;
-
-import static org.briarproject.bramble.api.system.SeedProvider.SEED_BYTES;
-import static org.junit.Assert.assertArrayEquals;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-
-public class LinuxSeedProviderTest extends BrambleTestCase {
-
-	private final File testDir = TestUtils.getTestDirectory();
-
-	@Before
-	public void setUp() {
-		testDir.mkdirs();
-	}
-
-	@Test
-	public void testSeedAppearsSane() {
-		if (!(OsUtils.isLinux())) {
-			System.err.println("WARNING: Skipping test, can't run on this OS");
-			return;
-		}
-		Set<Bytes> seeds = new HashSet<Bytes>();
-		LinuxSeedProvider p = new LinuxSeedProvider();
-		for (int i = 0; i < 1000; i++) {
-			byte[] seed = p.getSeed();
-			assertEquals(SEED_BYTES, seed.length);
-			assertTrue(seeds.add(new Bytes(seed)));
-		}
-	}
-
-	@Test
-	public void testEntropyIsWrittenToPool() throws Exception {
-		if (!(OsUtils.isLinux())) {
-			System.err.println("WARNING: Skipping test, can't run on this OS");
-			return;
-		}
-		// Redirect the provider's entropy to a file
-		File urandom = new File(testDir, "urandom");
-		urandom.delete();
-		assertTrue(urandom.createNewFile());
-		assertEquals(0, urandom.length());
-		String path = urandom.getAbsolutePath();
-		LinuxSeedProvider p = new LinuxSeedProvider(path, "/dev/urandom");
-		p.getSeed();
-		// There should be 16 bytes from the clock, plus network interfaces
-		assertTrue(urandom.length() > 20);
-	}
-
-	@Test
-	public void testSeedIsReadFromPool() throws Exception {
-		if (!(OsUtils.isLinux())) {
-			System.err.println("WARNING: Skipping test, can't run on this OS");
-			return;
-		}
-		// Generate a seed
-		byte[] seed = TestUtils.getRandomBytes(SEED_BYTES);
-		// Write the seed to a file
-		File urandom = new File(testDir, "urandom");
-		urandom.delete();
-		FileOutputStream out = new FileOutputStream(urandom);
-		out.write(seed);
-		out.flush();
-		out.close();
-		assertTrue(urandom.exists());
-		assertEquals(SEED_BYTES, urandom.length());
-		// Check that the provider reads the seed from the file
-		String path = urandom.getAbsolutePath();
-		LinuxSeedProvider p = new LinuxSeedProvider("/dev/urandom", path);
-		assertArrayEquals(seed, p.getSeed());
-	}
-
-	@After
-	public void tearDown() {
-		TestUtils.deleteTestDirectory(testDir);
-	}
-}

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

@@ -0,0 +1,16 @@
+package org.briarproject.bramble.test;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.system.SecureRandomProvider;
+
+import java.security.Provider;
+
+@NotNullByDefault
+public class TestSecureRandomProvider implements SecureRandomProvider {
+
+	@Override
+	public Provider getProvider() {
+		// Use the default provider
+		return null;
+	}
+}

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

@@ -1,13 +0,0 @@
-package org.briarproject.bramble.test;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.SeedProvider;
-
-@NotNullByDefault
-public class TestSeedProvider implements SeedProvider {
-
-	@Override
-	public byte[] getSeed() {
-		return TestUtils.getRandomBytes(32);
-	}
-}

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

@@ -1,6 +1,6 @@
 package org.briarproject.bramble.test;
 
-import org.briarproject.bramble.api.system.SeedProvider;
+import org.briarproject.bramble.api.system.SecureRandomProvider;
 
 import javax.inject.Singleton;
 
@@ -12,7 +12,7 @@ public class TestSeedProviderModule {
 
 	@Provides
 	@Singleton
-	SeedProvider provideSeedProvider() {
-		return new TestSeedProvider();
+	SecureRandomProvider provideSeedProvider() {
+		return new TestSecureRandomProvider();
 	}
 }

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

@@ -0,0 +1,16 @@
+package org.briarproject.bramble.test;
+
+import javax.net.SocketFactory;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class TestSocksModule {
+
+	@Provides
+	SocketFactory provideSocketFactory() {
+		return SocketFactory.getDefault();
+	}
+
+}

bramble-j2se/src/main/java/org/briarproject/bramble/system/DesktopSecureRandomModule.java

@@ -0,0 +1,19 @@
+package org.briarproject.bramble.system;
+
+import org.briarproject.bramble.api.system.SecureRandomProvider;
+import org.briarproject.bramble.util.OsUtils;
+
+import javax.inject.Singleton;
+
+import dagger.Module;
+import dagger.Provides;
+
+@Module
+public class DesktopSecureRandomModule {
+
+	@Provides
+	@Singleton
+	SecureRandomProvider provideSecureRandomProvider() {
+		return OsUtils.isLinux() ? new LinuxSecureRandomProvider() : null;
+	}
+}

bramble-j2se/src/main/java/org/briarproject/bramble/system/DesktopSeedProviderModule.java

@@ -1,19 +0,0 @@
-package org.briarproject.bramble.system;
-
-import org.briarproject.bramble.api.system.SeedProvider;
-import org.briarproject.bramble.util.OsUtils;
-
-import javax.inject.Singleton;
-
-import dagger.Module;
-import dagger.Provides;
-
-@Module
-public class DesktopSeedProviderModule {
-
-	@Provides
-	@Singleton
-	SeedProvider provideSeedProvider() {
-		return OsUtils.isLinux() ? new LinuxSeedProvider() : null;
-	}
-}

briar-android/build.gradle

@@ -82,6 +82,8 @@ android {
 	defaultConfig {
 		minSdkVersion 14
 		targetSdkVersion 22
+		versionCode 14
+		versionName "0.14"
 		resValue "string", "app_package", "org.briarproject.briar"
 		buildConfigField "String", "GitHash", "\"${getGitHash()}\""
 	}

briar-android/src/main/AndroidManifest.xml

@@ -1,9 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest
 	package="org.briarproject.briar"
-	xmlns:android="http://schemas.android.com/apk/res/android"
-	android:versionCode="13"
-	android:versionName="0.13">
+	xmlns:android="http://schemas.android.com/apk/res/android">
 
 	<uses-feature android:name="android.hardware.bluetooth"/>
 	<uses-feature android:name="android.hardware.camera" />
@@ -23,7 +21,7 @@
 	<application
 		android:name=".android.BriarApplicationImpl"
 		android:allowBackup="false"
-		android:icon="@drawable/ic_launcher"
+		android:icon="@mipmap/ic_launcher_round"
 		android:label="@string/app_name"
 		android:logo="@mipmap/ic_launcher_round"
 		android:theme="@style/BriarTheme">
@@ -333,7 +331,8 @@
 		<activity
 			android:name=".android.settings.SettingsActivity"
 			android:label="@string/settings_button"
-			android:parentActivityName=".android.navdrawer.NavDrawerActivity">
+			android:parentActivityName=".android.navdrawer.NavDrawerActivity"
+			android:permission="android.permission.READ_NETWORK_USAGE_HISTORY">
 			<meta-data
 				android:name="android.support.PARENT_ACTIVITY"
 				android:value=".android.navdrawer.NavDrawerActivity"
@@ -356,13 +355,12 @@
 
 		<activity
 			android:name=".android.panic.PanicPreferencesActivity"
-			android:label="@string/panic_setting">
-			<intent-filter>
-				<action android:name="info.guardianproject.panic.action.CONNECT"/>
-				<action android:name="info.guardianproject.panic.action.DISCONNECT"/>
-
-				<category android:name="android.intent.category.DEFAULT"/>
-			</intent-filter>
+			android:label="@string/panic_setting"
+			android:parentActivityName=".android.settings.SettingsActivity">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value=".android.settings.SettingsActivity"
+				/>
 		</activity>
 
 		<activity

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

@@ -28,9 +28,11 @@ import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.reporting.BriarReportSender;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.ReferenceManager;
+import org.briarproject.briar.api.android.ScreenFilterMonitor;
 import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogPostFactory;
 import org.briarproject.briar.api.blog.BlogSharingManager;
+import org.briarproject.briar.api.client.MessageTracker;
 import org.briarproject.briar.api.feed.FeedManager;
 import org.briarproject.briar.api.forum.ForumManager;
 import org.briarproject.briar.api.forum.ForumSharingManager;
@@ -43,6 +45,8 @@ import org.briarproject.briar.api.privategroup.PrivateGroupFactory;
 import org.briarproject.briar.api.privategroup.PrivateGroupManager;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationFactory;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager;
+import org.thoughtcrime.securesms.components.emoji.EmojiProvider;
+import org.thoughtcrime.securesms.components.emoji.RecentEmojiPageModel;
 
 import java.util.concurrent.Executor;
 
@@ -75,6 +79,8 @@ public interface AndroidComponent
 	@DatabaseExecutor
 	Executor databaseExecutor();
 
+	MessageTracker messageTracker();
+
 	LifecycleManager lifecycleManager();
 
 	IdentityManager identityManager();
@@ -87,6 +93,8 @@ public interface AndroidComponent
 
 	AndroidNotificationManager androidNotificationManager();
 
+	ScreenFilterMonitor screenFilterMonitor();
+
 	ConnectionRegistry connectionRegistry();
 
 	ContactManager contactManager();
@@ -138,10 +146,14 @@ public interface AndroidComponent
 	@IoExecutor
 	Executor ioExecutor();
 
-	void inject(BriarService activity);
+	void inject(BriarService briarService);
 
 	void inject(BriarReportSender briarReportSender);
 
+	void inject(EmojiProvider emojiProvider);
+
+	void inject(RecentEmojiPageModel recentEmojiPageModel);
+
 	// Eager singleton load
 	void inject(AppModule.EagerSingletons init);
 }

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

@@ -2,11 +2,8 @@ package org.briarproject.briar.android;
 
 import android.app.Application;
 import android.app.NotificationManager;
-import android.app.PendingIntent;
-import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
-import android.content.IntentFilter;
 import android.net.Uri;
 import android.os.Build;
 import android.support.annotation.UiThread;
@@ -62,7 +59,6 @@ import static android.app.Notification.DEFAULT_SOUND;
 import static android.app.Notification.DEFAULT_VIBRATE;
 import static android.content.Context.NOTIFICATION_SERVICE;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
-import static android.content.Intent.FLAG_ACTIVITY_SINGLE_TOP;
 import static android.support.v4.app.NotificationCompat.CATEGORY_MESSAGE;
 import static android.support.v4.app.NotificationCompat.CATEGORY_SOCIAL;
 import static android.support.v4.app.NotificationCompat.VISIBILITY_SECRET;
@@ -73,8 +69,6 @@ import static org.briarproject.briar.android.navdrawer.NavDrawerActivity.INTENT_
 import static org.briarproject.briar.android.navdrawer.NavDrawerActivity.INTENT_CONTACTS;
 import static org.briarproject.briar.android.navdrawer.NavDrawerActivity.INTENT_FORUMS;
 import static org.briarproject.briar.android.navdrawer.NavDrawerActivity.INTENT_GROUPS;
-import static org.briarproject.briar.android.settings.SettingsFragment.PREF_NOTIFY_BLOG;
-import static org.briarproject.briar.android.settings.SettingsFragment.PREF_NOTIFY_GROUP;
 import static org.briarproject.briar.android.settings.SettingsFragment.SETTINGS_NAMESPACE;
 
 @ThreadSafe
@@ -92,25 +86,13 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 
 	// Content URIs to differentiate between pending intents
 	private static final String CONTACT_URI =
-			"content://org.briarproject/contact";
+			"content://org.briarproject.briar/contact";
 	private static final String GROUP_URI =
-			"content://org.briarproject/group";
+			"content://org.briarproject.briar/group";
 	private static final String FORUM_URI =
-			"content://org.briarproject/forum";
+			"content://org.briarproject.briar/forum";
 	private static final String BLOG_URI =
-			"content://org.briarproject/blog";
-
-	// Actions for intents that are broadcast when notifications are dismissed
-	private static final String CLEAR_PRIVATE_MESSAGE_ACTION =
-			"org.briarproject.briar.CLEAR_PRIVATE_MESSAGE_NOTIFICATION";
-	private static final String CLEAR_GROUP_ACTION =
-			"org.briarproject.briar.CLEAR_GROUP_NOTIFICATION";
-	private static final String CLEAR_FORUM_ACTION =
-			"org.briarproject.briar.CLEAR_FORUM_NOTIFICATION";
-	private static final String CLEAR_BLOG_ACTION =
-			"org.briarproject.briar.CLEAR_BLOG_NOTIFICATION";
-	private static final String CLEAR_INTRODUCTION_ACTION =
-			"org.briarproject.briar.CLEAR_INTRODUCTION_NOTIFICATION";
+			"content://org.briarproject.briar/blog";
 
 	private static final Logger LOG =
 			Logger.getLogger(AndroidNotificationManagerImpl.class.getName());
@@ -119,7 +101,6 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	private final SettingsManager settingsManager;
 	private final AndroidExecutor androidExecutor;
 	private final Context appContext;
-	private final BroadcastReceiver receiver = new DeleteIntentReceiver();
 	private final AtomicBoolean used = new AtomicBoolean(false);
 
 	// The following must only be accessed on the main UI thread
@@ -157,30 +138,11 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		} catch (DbException e) {
 			throw new ServiceException(e);
 		}
-		// Register a broadcast receiver for notifications being dismissed
-		Future<Void> f = androidExecutor.runOnUiThread(new Callable<Void>() {
-			@Override
-			public Void call() {
-				IntentFilter filter = new IntentFilter();
-				filter.addAction(CLEAR_PRIVATE_MESSAGE_ACTION);
-				filter.addAction(CLEAR_GROUP_ACTION);
-				filter.addAction(CLEAR_FORUM_ACTION);
-				filter.addAction(CLEAR_BLOG_ACTION);
-				filter.addAction(CLEAR_INTRODUCTION_ACTION);
-				appContext.registerReceiver(receiver, filter);
-				return null;
-			}
-		});
-		try {
-			f.get();
-		} catch (InterruptedException | ExecutionException e) {
-			throw new ServiceException(e);
-		}
 	}
 
 	@Override
 	public void stopService() throws ServiceException {
-		// Clear all notifications and unregister the broadcast receiver
+		// Clear all notifications
 		Future<Void> f = androidExecutor.runOnUiThread(new Callable<Void>() {
 			@Override
 			public Void call() {
@@ -189,7 +151,6 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				clearForumPostNotification();
 				clearBlogPostNotification();
 				clearIntroductionSuccessNotification();
-				appContext.unregisterReceiver(receiver);
 				return null;
 			}
 		});
@@ -325,34 +286,30 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	private void updateContactNotification() {
 		if (contactTotal == 0) {
 			clearContactNotification();
-		} else if (settings.getBoolean("notifyPrivateMessages", true)) {
+		} else if (settings.getBoolean(PREF_NOTIFY_PRIVATE, true)) {
 			NotificationCompat.Builder b =
 					new NotificationCompat.Builder(appContext);
 			b.setSmallIcon(R.drawable.notification_private_message);
-			b.setColor(ContextCompat.getColor(appContext, R.color.briar_primary));
+			b.setColor(ContextCompat.getColor(appContext,
+					R.color.briar_primary));
 			b.setContentTitle(appContext.getText(R.string.app_name));
 			b.setContentText(appContext.getResources().getQuantityString(
 					R.plurals.private_message_notification_text, contactTotal,
 					contactTotal));
-			boolean sound = settings.getBoolean("notifySound", true);
-			String ringtoneUri = settings.get("notifyRingtoneUri");
+			boolean sound = settings.getBoolean(PREF_NOTIFY_SOUND, true);
+			String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
 			if (sound && !StringUtils.isNullOrEmpty(ringtoneUri))
 				b.setSound(Uri.parse(ringtoneUri));
 			b.setDefaults(getDefaults());
 			b.setOnlyAlertOnce(true);
 			b.setAutoCancel(true);
-			// Clear the counters if the notification is dismissed
-			Intent clear = new Intent(CLEAR_PRIVATE_MESSAGE_ACTION);
-			PendingIntent delete = PendingIntent.getBroadcast(appContext, 0,
-					clear, 0);
-			b.setDeleteIntent(delete);
 			if (contactCounts.size() == 1) {
 				// Touching the notification shows the relevant conversation
 				Intent i = new Intent(appContext, ConversationActivity.class);
 				ContactId c = contactCounts.keySet().iterator().next();
 				i.putExtra(CONTACT_ID, c.getInt());
 				i.setData(Uri.parse(CONTACT_URI + "/" + c.getInt()));
-				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 				TaskStackBuilder t = TaskStackBuilder.create(appContext);
 				t.addParentStack(ConversationActivity.class);
 				t.addNextIntent(i);
@@ -361,7 +318,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				// Touching the notification shows the contact list
 				Intent i = new Intent(appContext, NavDrawerActivity.class);
 				i.putExtra(INTENT_CONTACTS, true);
-				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 				i.setData(Uri.parse(CONTACT_URI));
 				TaskStackBuilder t = TaskStackBuilder.create(appContext);
 				t.addParentStack(NavDrawerActivity.class);
@@ -381,11 +338,11 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	@UiThread
 	private int getDefaults() {
 		int defaults = DEFAULT_LIGHTS;
-		boolean sound = settings.getBoolean("notifySound", true);
-		String ringtoneUri = settings.get("notifyRingtoneUri");
+		boolean sound = settings.getBoolean(PREF_NOTIFY_SOUND, true);
+		String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
 		if (sound && StringUtils.isNullOrEmpty(ringtoneUri))
 			defaults |= DEFAULT_SOUND;
-		if (settings.getBoolean("notifyVibration", true))
+		if (settings.getBoolean(PREF_NOTIFY_VIBRATION, true))
 			defaults |= DEFAULT_VIBRATE;
 		return defaults;
 	}
@@ -438,22 +395,18 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 			NotificationCompat.Builder b =
 					new NotificationCompat.Builder(appContext);
 			b.setSmallIcon(R.drawable.notification_private_group);
-			b.setColor(ContextCompat.getColor(appContext, R.color.briar_primary));
+			b.setColor(ContextCompat.getColor(appContext,
+					R.color.briar_primary));
 			b.setContentTitle(appContext.getText(R.string.app_name));
 			b.setContentText(appContext.getResources().getQuantityString(
 					R.plurals.group_message_notification_text, groupTotal,
 					groupTotal));
-			String ringtoneUri = settings.get("notifyRingtoneUri");
+			String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
 			if (!StringUtils.isNullOrEmpty(ringtoneUri))
 				b.setSound(Uri.parse(ringtoneUri));
 			b.setDefaults(getDefaults());
 			b.setOnlyAlertOnce(true);
 			b.setAutoCancel(true);
-			// Clear the counters if the notification is dismissed
-			Intent clear = new Intent(CLEAR_GROUP_ACTION);
-			PendingIntent delete = PendingIntent.getBroadcast(appContext, 0,
-					clear, 0);
-			b.setDeleteIntent(delete);
 			if (groupCounts.size() == 1) {
 				// Touching the notification shows the relevant group
 				Intent i = new Intent(appContext, GroupActivity.class);
@@ -461,7 +414,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				i.putExtra(GROUP_ID, g.getBytes());
 				String idHex = StringUtils.toHexString(g.getBytes());
 				i.setData(Uri.parse(GROUP_URI + "/" + idHex));
-				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 				TaskStackBuilder t = TaskStackBuilder.create(appContext);
 				t.addParentStack(GroupActivity.class);
 				t.addNextIntent(i);
@@ -470,7 +423,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				// Touching the notification shows the group list
 				Intent i = new Intent(appContext, NavDrawerActivity.class);
 				i.putExtra(INTENT_GROUPS, true);
-				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 				i.setData(Uri.parse(GROUP_URI));
 				TaskStackBuilder t = TaskStackBuilder.create(appContext);
 				t.addParentStack(NavDrawerActivity.class);
@@ -530,26 +483,22 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 	private void updateForumPostNotification() {
 		if (forumTotal == 0) {
 			clearForumPostNotification();
-		} else if (settings.getBoolean("notifyForumPosts", true)) {
+		} else if (settings.getBoolean(PREF_NOTIFY_FORUM, true)) {
 			NotificationCompat.Builder b =
 					new NotificationCompat.Builder(appContext);
 			b.setSmallIcon(R.drawable.notification_forum);
-			b.setColor(ContextCompat.getColor(appContext, R.color.briar_primary));
+			b.setColor(ContextCompat.getColor(appContext,
+					R.color.briar_primary));
 			b.setContentTitle(appContext.getText(R.string.app_name));
 			b.setContentText(appContext.getResources().getQuantityString(
 					R.plurals.forum_post_notification_text, forumTotal,
 					forumTotal));
-			String ringtoneUri = settings.get("notifyRingtoneUri");
+			String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
 			if (!StringUtils.isNullOrEmpty(ringtoneUri))
 				b.setSound(Uri.parse(ringtoneUri));
 			b.setDefaults(getDefaults());
 			b.setOnlyAlertOnce(true);
 			b.setAutoCancel(true);
-			// Clear the counters if the notification is dismissed
-			Intent clear = new Intent(CLEAR_FORUM_ACTION);
-			PendingIntent delete = PendingIntent.getBroadcast(appContext, 0,
-					clear, 0);
-			b.setDeleteIntent(delete);
 			if (forumCounts.size() == 1) {
 				// Touching the notification shows the relevant forum
 				Intent i = new Intent(appContext, ForumActivity.class);
@@ -557,7 +506,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				i.putExtra(GROUP_ID, g.getBytes());
 				String idHex = StringUtils.toHexString(g.getBytes());
 				i.setData(Uri.parse(FORUM_URI + "/" + idHex));
-				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 				TaskStackBuilder t = TaskStackBuilder.create(appContext);
 				t.addParentStack(ForumActivity.class);
 				t.addNextIntent(i);
@@ -566,7 +515,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 				// Touching the notification shows the forum list
 				Intent i = new Intent(appContext, NavDrawerActivity.class);
 				i.putExtra(INTENT_FORUMS, true);
-				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+				i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 				i.setData(Uri.parse(FORUM_URI));
 				TaskStackBuilder t = TaskStackBuilder.create(appContext);
 				t.addParentStack(NavDrawerActivity.class);
@@ -630,26 +579,22 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 			NotificationCompat.Builder b =
 					new NotificationCompat.Builder(appContext);
 			b.setSmallIcon(R.drawable.notification_blog);
-			b.setColor(ContextCompat.getColor(appContext, R.color.briar_primary));
+			b.setColor(ContextCompat.getColor(appContext,
+					R.color.briar_primary));
 			b.setContentTitle(appContext.getText(R.string.app_name));
 			b.setContentText(appContext.getResources().getQuantityString(
 					R.plurals.blog_post_notification_text, blogTotal,
 					blogTotal));
-			String ringtoneUri = settings.get("notifyRingtoneUri");
+			String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
 			if (!StringUtils.isNullOrEmpty(ringtoneUri))
 				b.setSound(Uri.parse(ringtoneUri));
 			b.setDefaults(getDefaults());
 			b.setOnlyAlertOnce(true);
 			b.setAutoCancel(true);
-			// Clear the counters if the notification is dismissed
-			Intent clear = new Intent(CLEAR_BLOG_ACTION);
-			PendingIntent delete = PendingIntent.getBroadcast(appContext, 0,
-					clear, 0);
-			b.setDeleteIntent(delete);
 			// Touching the notification shows the combined blog feed
 			Intent i = new Intent(appContext, NavDrawerActivity.class);
 			i.putExtra(INTENT_BLOGS, true);
-			i.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+			i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 			i.setData(Uri.parse(BLOG_URI));
 			TaskStackBuilder t = TaskStackBuilder.create(appContext);
 			t.addParentStack(NavDrawerActivity.class);
@@ -696,21 +641,16 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		b.setContentText(appContext.getResources().getQuantityString(
 				R.plurals.introduction_notification_text, introductionTotal,
 				introductionTotal));
-		String ringtoneUri = settings.get("notifyRingtoneUri");
+		String ringtoneUri = settings.get(PREF_NOTIFY_RINGTONE_URI);
 		if (!StringUtils.isNullOrEmpty(ringtoneUri))
 			b.setSound(Uri.parse(ringtoneUri));
 		b.setDefaults(getDefaults());
 		b.setOnlyAlertOnce(true);
 		b.setAutoCancel(true);
-		// Clear the counter if the notification is dismissed
-		Intent clear = new Intent(CLEAR_INTRODUCTION_ACTION);
-		PendingIntent delete = PendingIntent.getBroadcast(appContext, 0,
-				clear, 0);
-		b.setDeleteIntent(delete);
 		// Touching the notification shows the contact list
 		Intent i = new Intent(appContext, NavDrawerActivity.class);
 		i.putExtra(INTENT_CONTACTS, true);
-		i.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+		i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 		i.setData(Uri.parse(CONTACT_URI));
 		TaskStackBuilder t = TaskStackBuilder.create(appContext);
 		t.addParentStack(NavDrawerActivity.class);
@@ -847,27 +787,4 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		});
 	}
 
-	private class DeleteIntentReceiver extends BroadcastReceiver {
-
-		@Override
-		public void onReceive(Context context, Intent intent) {
-			final String action = intent.getAction();
-			androidExecutor.runOnUiThread(new Runnable() {
-				@Override
-				public void run() {
-					if (CLEAR_PRIVATE_MESSAGE_ACTION.equals(action)) {
-						clearContactNotification();
-					} else if (CLEAR_GROUP_ACTION.equals(action)) {
-						clearGroupMessageNotification();
-					} else if (CLEAR_FORUM_ACTION.equals(action)) {
-						clearForumPostNotification();
-					} else if (CLEAR_BLOG_ACTION.equals(action)) {
-						clearBlogPostNotification();
-					} else if (CLEAR_INTRODUCTION_ACTION.equals(action)) {
-						clearIntroductionSuccessNotification();
-					}
-				}
-			});
-		}
-	}
 }

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

@@ -16,6 +16,7 @@ import org.briarproject.bramble.api.ui.UiCallback;
 import org.briarproject.bramble.util.StringUtils;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.android.ReferenceManager;
+import org.briarproject.briar.api.android.ScreenFilterMonitor;
 
 import java.io.File;
 import java.security.GeneralSecurityException;
@@ -37,6 +38,8 @@ public class AppModule {
 	static class EagerSingletons {
 		@Inject
 		AndroidNotificationManager androidNotificationManager;
+		@Inject
+		ScreenFilterMonitor screenFilterMonitor;
 	}
 
 	private final Application application;
@@ -166,4 +169,12 @@ public class AppModule {
 		eventBus.addListener(notificationManager);
 		return notificationManager;
 	}
+
+	@Provides
+	@Singleton
+	ScreenFilterMonitor provideScreenFilterMonitor(
+			LifecycleManager lifecycleManager, ScreenFilterMonitorImpl sfm) {
+		lifecycleManager.registerService(sfm);
+		return sfm;
+	}
 }

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

@@ -28,7 +28,6 @@ import javax.inject.Inject;
 import static android.app.PendingIntent.FLAG_UPDATE_CURRENT;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.content.Intent.FLAG_ACTIVITY_NEW_TASK;
-import static android.content.Intent.FLAG_ACTIVITY_SINGLE_TOP;
 import static android.support.v4.app.NotificationCompat.CATEGORY_SERVICE;
 import static android.support.v4.app.NotificationCompat.PRIORITY_MIN;
 import static android.support.v4.app.NotificationCompat.VISIBILITY_SECRET;
@@ -83,8 +82,7 @@ public class BriarService extends Service {
 		b.setWhen(0); // Don't show the time
 		b.setOngoing(true);
 		Intent i = new Intent(this, NavDrawerActivity.class);
-		i.setFlags(FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TOP |
-				FLAG_ACTIVITY_SINGLE_TOP);
+		i.setFlags(FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TOP);
 		b.setContentIntent(PendingIntent.getActivity(this, 0, i, 0));
 		if (Build.VERSION.SDK_INT >= 21) {
 			b.setCategory(CATEGORY_SERVICE);

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

@@ -0,0 +1,282 @@
+package org.briarproject.briar.android;
+
+import android.app.Application;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.content.SharedPreferences;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.pm.Signature;
+import android.support.annotation.UiThread;
+import android.support.v7.preference.PreferenceManager;
+
+import org.briarproject.bramble.api.lifecycle.Service;
+import org.briarproject.bramble.api.lifecycle.ServiceException;
+import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
+import org.briarproject.bramble.api.system.AndroidExecutor;
+import org.briarproject.bramble.util.StringUtils;
+import org.briarproject.briar.api.android.ScreenFilterMonitor;
+
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
+import java.security.cert.CertificateException;
+import java.security.cert.CertificateFactory;
+import java.security.cert.X509Certificate;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.TreeSet;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.logging.Logger;
+
+import javax.annotation.Nullable;
+import javax.inject.Inject;
+
+import static android.Manifest.permission.SYSTEM_ALERT_WINDOW;
+import static android.content.Intent.ACTION_PACKAGE_ADDED;
+import static android.content.Intent.EXTRA_REPLACING;
+import static android.content.pm.ApplicationInfo.FLAG_SYSTEM;
+import static android.content.pm.ApplicationInfo.FLAG_UPDATED_SYSTEM_APP;
+import static android.content.pm.PackageManager.GET_PERMISSIONS;
+import static android.content.pm.PackageManager.GET_SIGNATURES;
+import static java.util.logging.Level.WARNING;
+
+@MethodsNotNullByDefault
+@ParametersNotNullByDefault
+public class ScreenFilterMonitorImpl extends BroadcastReceiver
+		implements Service, ScreenFilterMonitor {
+
+	private static final Logger LOG =
+			Logger.getLogger(ScreenFilterMonitorImpl.class.getName());
+	private static final String PREF_SCREEN_FILTER_APPS =
+			"shownScreenFilterApps";
+
+	/*
+ 	 * Ignore Play Services if it uses this package name and public key - it's
+	 * effectively a system app, but not flagged as such on older systems
+	 */
+	private static final String PLAY_SERVICES_PACKAGE =
+			"com.google.android.gms";
+	private static final String PLAY_SERVICES_PUBLIC_KEY =
+			"30820120300D06092A864886F70D01010105000382010D0030820108" +
+					"0282010100AB562E00D83BA208AE0A966F124E29DA11F2AB56D08F58" +
+					"E2CCA91303E9B754D372F640A71B1DCB130967624E4656A7776A9219" +
+					"3DB2E5BFB724A91E77188B0E6A47A43B33D9609B77183145CCDF7B2E" +
+					"586674C9E1565B1F4C6A5955BFF251A63DABF9C55C27222252E875E4" +
+					"F8154A645F897168C0B1BFC612EABF785769BB34AA7984DC7E2EA276" +
+					"4CAE8307D8C17154D7EE5F64A51A44A602C249054157DC02CD5F5C0E" +
+					"55FBEF8519FBE327F0B1511692C5A06F19D18385F5C4DBC2D6B93F68" +
+					"CC2979C70E18AB93866B3BD5DB8999552A0E3B4C99DF58FB918BEDC1" +
+					"82BA35E003C1B4B10DD244A8EE24FFFD333872AB5221985EDAB0FC0D" +
+					"0B145B6AA192858E79020103";
+
+	private final Context appContext;
+	private final AndroidExecutor androidExecutor;
+	private final PackageManager pm;
+	private final SharedPreferences prefs;
+	private final AtomicBoolean used = new AtomicBoolean(false);
+
+	// The following must only be accessed on the UI thread
+	private final Set<String> apps = new HashSet<>();
+	private final Set<String> shownApps;
+	private boolean serviceStarted = false;
+
+	@Inject
+	ScreenFilterMonitorImpl(AndroidExecutor executor, Application app) {
+		this.androidExecutor = executor;
+		this.appContext = app;
+		pm = appContext.getPackageManager();
+		prefs = PreferenceManager.getDefaultSharedPreferences(appContext);
+		shownApps = getShownScreenFilterApps();
+	}
+
+	@Override
+	public void startService() throws ServiceException {
+		if (used.getAndSet(true)) throw new IllegalStateException();
+		Future<Void> f = androidExecutor.runOnUiThread(new Callable<Void>() {
+			@Override
+			public Void call() {
+				IntentFilter intentFilter = new IntentFilter();
+				intentFilter.addAction(ACTION_PACKAGE_ADDED);
+				intentFilter.addDataScheme("package");
+				appContext.registerReceiver(ScreenFilterMonitorImpl.this,
+						intentFilter);
+				apps.addAll(getInstalledScreenFilterApps());
+				serviceStarted = true;
+				return null;
+			}
+		});
+		try {
+			f.get();
+		} catch (InterruptedException | ExecutionException e) {
+			throw new ServiceException(e);
+		}
+	}
+
+	@Override
+	public void stopService() throws ServiceException {
+		Future<Void> f = androidExecutor.runOnUiThread(new Callable<Void>() {
+			@Override
+			public Void call() {
+				serviceStarted = false;
+				appContext.unregisterReceiver(ScreenFilterMonitorImpl.this);
+				return null;
+			}
+		});
+		try {
+			f.get();
+		} catch (InterruptedException | ExecutionException e) {
+			throw new ServiceException(e);
+		}
+	}
+
+	private Set<String> getShownScreenFilterApps() {
+		// Result must not be modified
+		Set<String> s = prefs.getStringSet(PREF_SCREEN_FILTER_APPS, null);
+		HashSet<String> result = new HashSet<>();
+		if (s != null) {
+			result.addAll(s);
+		}
+		return result;
+	}
+
+	@Override
+	public void onReceive(Context context, Intent intent) {
+		if (!intent.getBooleanExtra(EXTRA_REPLACING, false)) {
+			final String packageName =
+					intent.getData().getEncodedSchemeSpecificPart();
+			androidExecutor.runOnUiThread(new Runnable() {
+				@Override
+				public void run() {
+					String pkg = isOverlayApp(packageName);
+					if (pkg == null) {
+						return;
+					}
+					apps.add(pkg);
+				}
+			});
+		}
+	}
+
+	@Override
+	@UiThread
+	public Set<String> getApps() {
+		if (!serviceStarted) {
+			apps.addAll(getInstalledScreenFilterApps());
+		}
+		TreeSet<String> buf = new TreeSet<>();
+		if (apps.isEmpty()) {
+			return buf;
+		}
+		buf.addAll(apps);
+		buf.removeAll(shownApps);
+		return buf;
+	}
+
+	@Override
+	@UiThread
+	public void storeAppsAsShown(Collection<String> s, boolean persistent) {
+		HashSet<String> buf = new HashSet<>(s);
+		shownApps.addAll(buf);
+		if (persistent && !s.isEmpty()) {
+			buf.addAll(getShownScreenFilterApps());
+			prefs.edit()
+					.putStringSet(PREF_SCREEN_FILTER_APPS, buf)
+					.apply();
+		}
+	}
+
+	private Set<String> getInstalledScreenFilterApps() {
+		HashSet<String> screenFilterApps = new HashSet<>();
+		List<PackageInfo> packageInfos =
+				pm.getInstalledPackages(GET_PERMISSIONS);
+		for (PackageInfo packageInfo : packageInfos) {
+			if (isOverlayApp(packageInfo)) {
+				String name = pkgToString(packageInfo);
+				if (name != null) {
+					screenFilterApps.add(name);
+				}
+			}
+		}
+		return screenFilterApps;
+	}
+
+	// Checks if a package uses the SYSTEM_ALERT_WINDOW permission and if so
+	// returns the app name.
+	@Nullable
+	private String isOverlayApp(String pkg) {
+		try {
+			PackageInfo pkgInfo = pm.getPackageInfo(pkg, GET_PERMISSIONS);
+			if (isOverlayApp(pkgInfo)) {
+				return pkgToString(pkgInfo);
+			}
+		} catch (NameNotFoundException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+		}
+		return null;
+	}
+
+	// Fetches the application name for a given package.
+	@Nullable
+	private String pkgToString(PackageInfo pkgInfo) {
+		CharSequence seq = pm.getApplicationLabel(pkgInfo.applicationInfo);
+		if (seq != null) {
+			return seq.toString();
+		}
+		return null;
+	}
+
+	// Checks if an installed package is a user app using the permission.
+	private boolean isOverlayApp(PackageInfo packageInfo) {
+		int mask = FLAG_SYSTEM | FLAG_UPDATED_SYSTEM_APP;
+		// Ignore system apps
+		if ((packageInfo.applicationInfo.flags & mask) != 0) {
+			return false;
+		}
+		// Ignore Play Services, it's effectively a system app
+		if (isPlayServices(packageInfo.packageName)) {
+			return false;
+		}
+		// Get permissions
+		String[] requestedPermissions = packageInfo.requestedPermissions;
+		if (requestedPermissions != null) {
+			for (String requestedPermission : requestedPermissions) {
+				if (requestedPermission.equals(SYSTEM_ALERT_WINDOW)) {
+					return true;
+				}
+			}
+		}
+		return false;
+	}
+
+	private boolean isPlayServices(String pkg) {
+		if (!PLAY_SERVICES_PACKAGE.equals(pkg)) return false;
+		try {
+			PackageInfo sigs = pm.getPackageInfo(pkg, GET_SIGNATURES);
+			// The genuine Play Services app should have a single signature
+			Signature[] signatures = sigs.signatures;
+			if (signatures == null || signatures.length != 1) return false;
+			// Extract the public key from the signature
+			CertificateFactory certFactory =
+					CertificateFactory.getInstance("X509");
+			byte[] signatureBytes = signatures[0].toByteArray();
+			InputStream in = new ByteArrayInputStream(signatureBytes);
+			X509Certificate cert =
+					(X509Certificate) certFactory.generateCertificate(in);
+			byte[] publicKeyBytes = cert.getPublicKey().getEncoded();
+			String publicKey = StringUtils.toHexString(publicKeyBytes);
+			return PLAY_SERVICES_PUBLIC_KEY.equals(publicKey);
+		} catch (NameNotFoundException | CertificateException e) {
+			if (LOG.isLoggable(WARNING)) LOG.log(WARNING, e.toString(), e);
+			return false;
+		}
+	}
+}

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

@@ -1,5 +1,7 @@
 package org.briarproject.briar.android;
 
+import org.briarproject.briar.BuildConfig;
+
 import java.util.logging.Level;
 
 import static java.util.logging.Level.INFO;
@@ -11,7 +13,7 @@ public interface TestingConstants {
 	 * Whether this is an alpha or beta build. This should be set to false for
 	 * release builds.
 	 */
-	boolean TESTING = true;
+	boolean TESTING = BuildConfig.DEBUG;
 
 	/** Default log level. */
 	Level DEFAULT_LOG_LEVEL = TESTING ? INFO : OFF;

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

@@ -64,8 +64,6 @@ import org.briarproject.briar.android.sharing.ShareForumFragment;
 import org.briarproject.briar.android.sharing.ShareForumMessageFragment;
 import org.briarproject.briar.android.sharing.SharingModule;
 import org.briarproject.briar.android.splash.SplashScreenActivity;
-import org.thoughtcrime.securesms.components.emoji.EmojiProvider;
-import org.thoughtcrime.securesms.components.emoji.RecentEmojiPageModel;
 
 import dagger.Component;
 
@@ -151,10 +149,6 @@ public interface ActivityComponent {
 
 	void inject(RssFeedManageActivity activity);
 
-	void inject(EmojiProvider emojiProvider);
-
-	void inject(RecentEmojiPageModel recentEmojiPageModel);
-
 	// Fragments
 	void inject(ContactListFragment fragment);
 

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

@@ -13,11 +13,15 @@ import org.briarproject.briar.android.BriarApplication;
 import org.briarproject.briar.android.DestroyableContext;
 import org.briarproject.briar.android.controller.ActivityLifecycleController;
 import org.briarproject.briar.android.forum.ForumModule;
+import org.briarproject.briar.android.fragment.SFDialogFragment;
+import org.briarproject.briar.api.android.ScreenFilterMonitor;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Set;
 
 import javax.annotation.Nullable;
+import javax.inject.Inject;
 
 import static android.view.WindowManager.LayoutParams.FLAG_SECURE;
 import static android.view.inputmethod.InputMethodManager.SHOW_IMPLICIT;
@@ -25,13 +29,16 @@ import static org.briarproject.briar.android.TestingConstants.PREVENT_SCREENSHOT
 
 public abstract class BaseActivity extends AppCompatActivity
 		implements DestroyableContext {
-
 	protected ActivityComponent activityComponent;
 
 	private final List<ActivityLifecycleController> lifecycleControllers =
 			new ArrayList<>();
 	private boolean destroyed = false;
 
+	@Inject
+	protected ScreenFilterMonitor screenFilterMonitor;
+	private SFDialogFragment dialogFrag;
+
 	public abstract void injectActivity(ActivityComponent component);
 
 	public void addLifecycleController(ActivityLifecycleController alc) {
@@ -58,6 +65,7 @@ public abstract class BaseActivity extends AppCompatActivity
 		for (ActivityLifecycleController alc : lifecycleControllers) {
 			alc.onActivityCreate(this);
 		}
+
 	}
 
 	public ActivityComponent getActivityComponent() {
@@ -89,6 +97,35 @@ public abstract class BaseActivity extends AppCompatActivity
 		}
 	}
 
+	@Override
+	protected void onPostResume() {
+		super.onPostResume();
+		showNewScreenFilterWarning();
+	}
+
+	@Override
+	protected void onPause() {
+		super.onPause();
+		if (dialogFrag != null) {
+			dialogFrag.dismiss();
+			dialogFrag = null;
+		}
+	}
+
+	protected void showNewScreenFilterWarning() {
+		final Set<String> apps = screenFilterMonitor.getApps();
+		if (apps.isEmpty()) {
+			return;
+		}
+		dialogFrag = SFDialogFragment.newInstance(new ArrayList<>(apps));
+		dialogFrag.setCancelable(false);
+		dialogFrag.show(getSupportFragmentManager(), "SFDialog");
+	}
+
+	public void rememberShownApps(ArrayList<String> s, boolean permanent) {
+		screenFilterMonitor.storeAppsAsShown(s, permanent);
+	}
+
 	@Override
 	protected void onDestroy() {
 		super.onDestroy();

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

@@ -3,7 +3,6 @@ package org.briarproject.briar.android.activity;
 import android.annotation.SuppressLint;
 import android.content.Intent;
 import android.os.Build;
-import android.support.annotation.Nullable;
 import android.support.v7.app.ActionBar;
 import android.support.v7.widget.Toolbar;
 import android.transition.Slide;
@@ -14,20 +13,20 @@ import android.view.Window;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.controller.BriarController;
 import org.briarproject.briar.android.controller.DbController;
-import org.briarproject.briar.android.controller.handler.UiResultHandler;
+import org.briarproject.briar.android.controller.handler.ResultHandler;
 import org.briarproject.briar.android.fragment.BaseFragment;
 import org.briarproject.briar.android.login.PasswordActivity;
 import org.briarproject.briar.android.panic.ExitActivity;
 
 import java.util.logging.Logger;
 
+import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TASK;
 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.content.Intent.FLAG_ACTIVITY_SINGLE_TOP;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_PASSWORD;
 
 @SuppressLint("Registered")
@@ -61,7 +60,6 @@ public abstract class BriarActivity extends BaseActivity {
 		super.onStart();
 		if (!briarController.hasEncryptionKey() && !isFinishing()) {
 			Intent i = new Intent(this, PasswordActivity.class);
-			i.setFlags(FLAG_ACTIVITY_SINGLE_TOP);
 			startActivityForResult(i, REQUEST_PASSWORD);
 		}
 	}
@@ -118,17 +116,28 @@ public abstract class BriarActivity extends BaseActivity {
 	}
 
 	protected void signOut(final boolean removeFromRecentApps) {
-		briarController.signOut(new UiResultHandler<Void>(this) {
-			@Override
-			public void onResultUi(Void result) {
-				if (removeFromRecentApps) startExitActivity();
-				else finishAndExit();
-			}
-		});
+		if (briarController.hasEncryptionKey()) {
+			// Don't use UiResultHandler because we want the result even if
+			// this activity has been destroyed
+			briarController.signOut(new ResultHandler<Void>() {
+				@Override
+				public void onResult(Void result) {
+					runOnUiThread(new Runnable() {
+						@Override
+						public void run() {
+							exit(removeFromRecentApps);
+						}
+					});
+				}
+			});
+		} else {
+			exit(removeFromRecentApps);
+		}
 	}
 
-	protected void signOut() {
-		signOut(false);
+	private void exit(boolean removeFromRecentApps) {
+		if (removeFromRecentApps) startExitActivity();
+		else finishAndExit();
 	}
 
 	private void startExitActivity() {

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

@@ -21,6 +21,7 @@ import org.briarproject.briar.api.blog.Blog;
 import org.briarproject.briar.api.blog.BlogCommentHeader;
 import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogPostHeader;
+import org.briarproject.briar.util.HtmlUtils;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -33,6 +34,7 @@ import javax.annotation.Nullable;
 
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.briar.util.HtmlUtils.ARTICLE;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
@@ -229,6 +231,7 @@ abstract class BaseControllerImpl extends DbControllerImpl
 		return header;
 	}
 
+	@DatabaseExecutor
 	private BlogPostItem getItem(BlogPostHeader h) throws DbException {
 		String body;
 		if (h instanceof BlogCommentHeader) {
@@ -243,10 +246,11 @@ abstract class BaseControllerImpl extends DbControllerImpl
 		}
 	}
 
+	@DatabaseExecutor
 	private String getPostBody(MessageId m) throws DbException {
 		String body = bodyCache.get(m);
 		if (body == null) {
-			body = blogManager.getPostBody(m);
+			body = HtmlUtils.clean(blogManager.getPostBody(m), ARTICLE);
 			bodyCache.put(m, body);
 		}
 		//noinspection ConstantConditions

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

@@ -2,7 +2,6 @@ package org.briarproject.briar.android.blog;
 
 import android.content.Intent;
 import android.os.Bundle;
-import android.support.annotation.Nullable;
 import android.support.v7.widget.Toolbar;
 import android.view.View;
 
@@ -15,6 +14,7 @@ import org.briarproject.briar.android.activity.BriarActivity;
 import org.briarproject.briar.android.fragment.BaseFragment.BaseFragmentListener;
 import org.briarproject.briar.android.sharing.BlogSharingStatusActivity;
 
+import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 @MethodsNotNullByDefault

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

@@ -169,7 +169,7 @@ class BlogControllerImpl extends BaseControllerImpl
 					LocalAuthor a = identityManager.getLocalAuthor();
 					Blog b = blogManager.getBlog(groupId);
 					boolean ours = a.getId().equals(b.getAuthor().getId());
-					boolean removable = blogManager.canBeRemoved(groupId);
+					boolean removable = blogManager.canBeRemoved(b);
 					BlogItem blog = new BlogItem(b, ours, removable);
 					long duration = System.currentTimeMillis() - now;
 					if (LOG.isLoggable(INFO))

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

@@ -43,7 +43,6 @@ import javax.inject.Inject;
 
 import static android.app.Activity.RESULT_OK;
 import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
-import static android.content.Intent.FLAG_ACTIVITY_SINGLE_TOP;
 import static android.widget.Toast.LENGTH_SHORT;
 import static org.briarproject.briar.android.activity.BriarActivity.GROUP_ID;
 import static org.briarproject.briar.android.activity.RequestCodes.REQUEST_SHARE_BLOG;
@@ -149,14 +148,14 @@ public class BlogFragment extends BaseFragment
 				return true;
 			case R.id.action_blog_share:
 				Intent i2 = new Intent(getActivity(), ShareBlogActivity.class);
-				i2.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+				i2.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 				i2.putExtra(GROUP_ID, groupId.getBytes());
 				startActivityForResult(i2, REQUEST_SHARE_BLOG);
 				return true;
 			case R.id.action_blog_sharing_status:
 				Intent i3 = new Intent(getActivity(),
 						BlogSharingStatusActivity.class);
-				i3.setFlags(FLAG_ACTIVITY_CLEAR_TOP | FLAG_ACTIVITY_SINGLE_TOP);
+				i3.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
 				i3.putExtra(GROUP_ID, groupId.getBytes());
 				startActivity(i3);
 				return true;

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

@@ -48,6 +48,10 @@ public class BlogPostItem implements Comparable<BlogPostItem> {
 		return body;
 	}
 
+	public boolean isRssFeed() {
+		return header.isRssFeed();
+	}
+
 	public boolean isRead() {
 		return read;
 	}

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

@@ -108,7 +108,8 @@ class BlogPostViewHolder extends RecyclerView.ViewHolder {
 		author.setAuthor(a);
 		author.setAuthorStatus(post.getAuthorStatus());
 		author.setDate(post.getTimestamp());
-		author.setPersona(AuthorView.NORMAL);
+		author.setPersona(
+				item.isRssFeed() ? AuthorView.RSS_FEED : AuthorView.NORMAL);
 		// TODO make author clickable more often #624
 		if (item.getHeader().getType() == POST) {
 			author.setBlogLink(post.getGroupId());
@@ -168,7 +169,9 @@ class BlogPostViewHolder extends RecyclerView.ViewHolder {
 		reblogger.setVisibility(VISIBLE);
 		reblogger.setPersona(AuthorView.REBLOGGER);
 
-		author.setPersona(AuthorView.COMMENTER);
+		author.setPersona(item.getHeader().getRootPost().isRssFeed() ?
+				AuthorView.RSS_FEED_REBLOGGED :
+				AuthorView.COMMENTER);
 
 		// comments
 		for (BlogCommentHeader c : item.getComments()) {

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

@@ -179,7 +179,6 @@ public class FeedFragment extends BaseFragment implements
 			case R.id.action_rss_feeds_import:
 				Intent i2 =
 						new Intent(getActivity(), RssFeedImportActivity.class);
-				i2.putExtra(GROUP_ID, personalBlog.getId().getBytes());
 				startActivity(i2);
 				return true;
 			case R.id.action_rss_feeds_manage:

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

@@ -6,7 +6,7 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.view.ViewGroup;
-import android.widget.ImageView;
+import android.widget.ImageButton;
 import android.widget.TextView;
 
 import org.briarproject.briar.R;
@@ -39,12 +39,7 @@ class RssFeedAdapter extends BriarAdapter<Feed, RssFeedAdapter.FeedViewHolder> {
 		if (item == null) return;
 
 		// Feed Title
-		if (item.getTitle() != null) {
-			ui.title.setText(item.getTitle());
-			ui.title.setVisibility(VISIBLE);
-		} else {
-			ui.title.setVisibility(GONE);
-		}
+		ui.title.setText(item.getTitle());
 
 		// Delete Button
 		ui.delete.setOnClickListener(new OnClickListener() {
@@ -75,6 +70,14 @@ class RssFeedAdapter extends BriarAdapter<Feed, RssFeedAdapter.FeedViewHolder> {
 		} else {
 			ui.description.setVisibility(GONE);
 		}
+
+		// Open feed's blog when clicked
+		ui.layout.setOnClickListener(new OnClickListener() {
+			@Override
+			public void onClick(View v) {
+				listener.onFeedClick(item);
+			}
+		});
 	}
 
 	@Override
@@ -99,8 +102,9 @@ class RssFeedAdapter extends BriarAdapter<Feed, RssFeedAdapter.FeedViewHolder> {
 	}
 
 	static class FeedViewHolder extends RecyclerView.ViewHolder {
+		private final View layout;
 		private final TextView title;
-		private final ImageView delete;
+		private final ImageButton delete;
 		private final TextView imported;
 		private final TextView updated;
 		private final TextView author;
@@ -110,8 +114,9 @@ class RssFeedAdapter extends BriarAdapter<Feed, RssFeedAdapter.FeedViewHolder> {
 		private FeedViewHolder(View v) {
 			super(v);
 
+			layout = v;
 			title = (TextView) v.findViewById(R.id.titleView);
-			delete = (ImageView) v.findViewById(R.id.deleteButton);
+			delete = (ImageButton) v.findViewById(R.id.deleteButton);
 			imported = (TextView) v.findViewById(R.id.importedView);
 			updated = (TextView) v.findViewById(R.id.updatedView);
 			author = (TextView) v.findViewById(R.id.authorView);
@@ -121,6 +126,7 @@ class RssFeedAdapter extends BriarAdapter<Feed, RssFeedAdapter.FeedViewHolder> {
 	}
 
 	interface RssFeedListener {
+		void onFeedClick(Feed feed);
 		void onDeleteClick(Feed feed);
 	}
 

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

@@ -1,7 +1,6 @@
 package org.briarproject.briar.android.blog;
 
 import android.content.DialogInterface;
-import android.content.Intent;
 import android.os.Bundle;
 import android.support.v7.app.AlertDialog;
 import android.text.Editable;
@@ -15,7 +14,6 @@ import android.widget.ProgressBar;
 
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
-import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
@@ -44,9 +42,6 @@ public class RssFeedImportActivity extends BriarActivity {
 	@IoExecutor
 	Executor ioExecutor;
 
-	// Fields that are accessed from background threads must be volatile
-	private volatile GroupId groupId = null;
-
 	@Inject
 	@SuppressWarnings("WeakerAccess")
 	volatile FeedManager feedManager;
@@ -55,12 +50,6 @@ public class RssFeedImportActivity extends BriarActivity {
 	public void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 
-		// GroupId from Intent
-		Intent i = getIntent();
-		byte[] b = i.getByteArrayExtra(GROUP_ID);
-		if (b == null) throw new IllegalStateException("No Group in intent.");
-		groupId = new GroupId(b);
-
 		setContentView(R.layout.activity_rss_feed_import);
 
 		urlInput = (EditText) findViewById(R.id.urlInput);
@@ -128,7 +117,7 @@ public class RssFeedImportActivity extends BriarActivity {
 			@Override
 			public void run() {
 				try {
-					feedManager.addFeed(url, groupId);
+					feedManager.addFeed(url);
 					feedImported();
 				} catch (DbException | IOException e) {
 					if (LOG.isLoggable(WARNING))

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

@@ -1,15 +1,16 @@
 package org.briarproject.briar.android.blog;
 
+import android.content.DialogInterface;
 import android.content.Intent;
 import android.os.Bundle;
 import android.support.design.widget.Snackbar;
+import android.support.v7.app.AlertDialog;
 import android.support.v7.widget.LinearLayoutManager;
 import android.view.Menu;
 import android.view.MenuInflater;
 import android.view.MenuItem;
 
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.activity.ActivityComponent;
 import org.briarproject.briar.android.activity.BriarActivity;
@@ -23,6 +24,7 @@ import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
+import static android.content.Intent.FLAG_ACTIVITY_CLEAR_TOP;
 import static android.support.design.widget.Snackbar.LENGTH_LONG;
 import static java.util.logging.Level.WARNING;
 
@@ -34,7 +36,6 @@ public class RssFeedManageActivity extends BriarActivity
 
 	private BriarRecyclerView list;
 	private RssFeedAdapter adapter;
-	private GroupId groupId;
 
 	@Inject
 	@SuppressWarnings("WeakerAccess")
@@ -44,12 +45,6 @@ public class RssFeedManageActivity extends BriarActivity
 	public void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
 
-		// GroupId from Intent
-		Intent i = getIntent();
-		byte[] b = i.getByteArrayExtra(GROUP_ID);
-		if (b == null) throw new IllegalStateException("No Group in intent.");
-		groupId = new GroupId(b);
-
 		setContentView(R.layout.activity_rss_feed_manage);
 
 		adapter = new RssFeedAdapter(this, this);
@@ -87,7 +82,6 @@ public class RssFeedManageActivity extends BriarActivity
 				return true;
 			case R.id.action_rss_feeds_import:
 				Intent i = new Intent(this, RssFeedImportActivity.class);
-				i.putExtra(GROUP_ID, groupId.getBytes());
 				startActivity(i);
 				return true;
 			default:
@@ -100,21 +94,32 @@ public class RssFeedManageActivity extends BriarActivity
 		component.inject(this);
 	}
 
+	@Override
+	public void onFeedClick(Feed feed) {
+		Intent i = new Intent(this, BlogActivity.class);
+		i.putExtra(GROUP_ID, feed.getBlogId().getBytes());
+		i.setFlags(FLAG_ACTIVITY_CLEAR_TOP);
+		startActivity(i);
+	}
+
 	@Override
 	public void onDeleteClick(final Feed feed) {
-		runOnDbThread(new Runnable() {
-			@Override
-			public void run() {
-				try {
-					feedManager.removeFeed(feed.getUrl());
-					onFeedDeleted(feed);
-				} catch (DbException e) {
-					if (LOG.isLoggable(WARNING))
-						LOG.log(WARNING, e.toString(), e);
-					onDeleteError();
-				}
-			}
-		});
+		DialogInterface.OnClickListener okListener =
+				new DialogInterface.OnClickListener() {
+					@Override
+					public void onClick(DialogInterface dialog, int which) {
+						deleteFeed(feed);
+					}
+				};
+		AlertDialog.Builder builder = new AlertDialog.Builder(this,
+				R.style.BriarDialogTheme);
+		builder.setTitle(getString(R.string.blogs_rss_remove_feed));
+		builder.setMessage(
+				getString(R.string.blogs_rss_remove_feed_dialog_message));
+		builder.setPositiveButton(R.string.cancel, null);
+		builder.setNegativeButton(R.string.blogs_rss_remove_feed_ok,
+				okListener);
+		builder.show();
 	}
 
 	private void loadFeeds() {
@@ -149,6 +154,22 @@ public class RssFeedManageActivity extends BriarActivity
 		});
 	}
 
+	private void deleteFeed(final Feed feed) {
+		runOnDbThread(new Runnable() {
+			@Override
+			public void run() {
+				try {
+					feedManager.removeFeed(feed);
+					onFeedDeleted(feed);
+				} catch (DbException e) {
+					if (LOG.isLoggable(WARNING))
+						LOG.log(WARNING, e.toString(), e);
+					onDeleteError();
+				}
+			}
+		});
+	}
+
 	private void onLoadError() {
 		runOnUiThreadUnlessDestroyed(new Runnable() {
 			@Override

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

@@ -1,6 +1,5 @@
 package org.briarproject.briar.android.contact;
 
-import android.support.annotation.Nullable;
 import android.support.annotation.UiThread;
 import android.support.v7.widget.RecyclerView;
 import android.view.View;
@@ -13,6 +12,8 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.briar.R;
 import org.briarproject.briar.android.contact.BaseContactListAdapter.OnContactClickListener;
 
+import javax.annotation.Nullable;
+
 import im.delight.android.identicons.IdenticonDrawable;
 
 @UiThread

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

@@ -946,6 +946,7 @@ public class ConversationActivity extends BriarActivity
 	@Override
 	public void respondToRequest(final ConversationRequestItem item,
 			final boolean accept) {
+		item.setAnswered(true);
 		int position = adapter.findItemPosition(item);
 		if (position != INVALID_POSITION) {
 			adapter.notifyItemChanged(position, item);

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

@@ -21,7 +21,8 @@ class ConversationRequestItem extends ConversationNoticeInItem {
 	private final GroupId requestedGroupId;
 	private final RequestType requestType;
 	private final SessionId sessionId;
-	private final boolean answered, canBeOpened;
+	private final boolean canBeOpened;
+	private boolean answered;
 
 	ConversationRequestItem(MessageId id, GroupId groupId,
 			RequestType requestType, SessionId sessionId, String text,
@@ -53,6 +54,10 @@ class ConversationRequestItem extends ConversationNoticeInItem {
 		return answered;
 	}
 
+	void setAnswered(boolean answered) {
+		this.answered = answered;
+	}
+
 	public boolean canBeOpened() {
 		return canBeOpened;
 	}

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

@@ -51,6 +51,8 @@ class ConversationRequestViewHolder extends ConversationNoticeInViewHolder {
 			acceptButton.setOnClickListener(new OnClickListener() {
 				@Override
 				public void onClick(View v) {
+					acceptButton.setEnabled(false);
+					declineButton.setEnabled(false);
 					listener.respondToRequest(item, true);
 				}
 			});
@@ -58,6 +60,8 @@ class ConversationRequestViewHolder extends ConversationNoticeInViewHolder {
 			declineButton.setOnClickListener(new OnClickListener() {
 				@Override
 				public void onClick(View v) {
+					acceptButton.setEnabled(false);
+					declineButton.setEnabled(false);
 					listener.respondToRequest(item, false);
 				}
 			});

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

@@ -17,7 +17,7 @@ public class DbControllerImpl implements DbController {
 	private static final Logger LOG =
 			Logger.getLogger(DbControllerImpl.class.getName());
 
-	private final Executor dbExecutor;
+	protected final Executor dbExecutor;
 	private final LifecycleManager lifecycleManager;
 
 	@Inject

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

@@ -1,7 +1,5 @@
 package org.briarproject.briar.android.controller;
 
-import android.support.annotation.Nullable;
-
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventBus;
@@ -15,6 +13,7 @@ import java.util.Collection;
 import java.util.HashSet;
 import java.util.Set;
 
+import javax.annotation.Nullable;
 import javax.inject.Inject;
 
 @NotNullByDefault