Check for concurrent cache updates.

and display attachments as they arrive while ImageActivity is open.

.gitlab-ci.yml

@@ -17,7 +17,7 @@ test:
 
   script:
     - ./gradlew --no-daemon -Djava.security.egd=file:/dev/urandom animalSnifferMain animalSnifferTest
-    - ./gradlew --no-daemon -Djava.security.egd=file:/dev/urandom test
+    - ./gradlew --no-daemon -Djava.security.egd=file:/dev/urandom check compileOfficialDebugAndroidTestSources compileScreenshotDebugAndroidTestSources
 
   after_script:
     # these file change every time but should not be cached

.idea/codeStyles/Project.xml

@@ -1,16 +1,10 @@
 <component name="ProjectCodeStyleConfiguration">
   <code_scheme name="Project" version="173">
-    <option name="RIGHT_MARGIN" value="100" />
     <AndroidXmlCodeStyleSettings>
-      <option name="USE_CUSTOM_SETTINGS" value="true" />
+      <option name="ARRANGEMENT_SETTINGS_MIGRATED_TO_191" value="true" />
     </AndroidXmlCodeStyleSettings>
     <JavaCodeStyleSettings>
       <option name="ANNOTATION_PARAMETER_WRAP" value="1" />
-      <option name="CLASS_COUNT_TO_USE_IMPORT_ON_DEMAND" value="99" />
-      <option name="NAMES_COUNT_TO_USE_IMPORT_ON_DEMAND" value="99" />
-      <option name="PACKAGES_TO_USE_IMPORT_ON_DEMAND">
-        <value />
-      </option>
       <option name="IMPORT_LAYOUT_TABLE">
         <value>
           <package name="android" withSubpackages="true" static="false" />
@@ -77,7 +71,6 @@
       </indentOptions>
     </codeStyleSettings>
     <codeStyleSettings language="XML">
-      <option name="FORCE_REARRANGE_MODE" value="1" />
       <indentOptions>
         <option name="CONTINUATION_INDENT_SIZE" value="4" />
         <option name="USE_TAB_CHARACTER" value="true" />
@@ -90,7 +83,8 @@
               <match>
                 <AND>
                   <NAME>xmlns:android</NAME>
-                  <XML_NAMESPACE>Namespace:</XML_NAMESPACE>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
                 </AND>
               </match>
             </rule>
@@ -100,7 +94,8 @@
               <match>
                 <AND>
                   <NAME>xmlns:.*</NAME>
-                  <XML_NAMESPACE>Namespace:</XML_NAMESPACE>
+                  <XML_ATTRIBUTE />
+                  <XML_NAMESPACE>^$</XML_NAMESPACE>
                 </AND>
               </match>
               <order>BY_NAME</order>
@@ -111,6 +106,7 @@
               <match>
                 <AND>
                   <NAME>.*:id</NAME>
+                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
                 </AND>
               </match>
@@ -121,6 +117,7 @@
               <match>
                 <AND>
                   <NAME>.*:name</NAME>
+                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
                 </AND>
               </match>
@@ -131,6 +128,7 @@
               <match>
                 <AND>
                   <NAME>name</NAME>
+                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>^$</XML_NAMESPACE>
                 </AND>
               </match>
@@ -141,6 +139,7 @@
               <match>
                 <AND>
                   <NAME>style</NAME>
+                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>^$</XML_NAMESPACE>
                 </AND>
               </match>
@@ -151,6 +150,7 @@
               <match>
                 <AND>
                   <NAME>.*</NAME>
+                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>^$</XML_NAMESPACE>
                 </AND>
               </match>
@@ -161,64 +161,12 @@
             <rule>
               <match>
                 <AND>
-                  <NAME>.*:layout_width</NAME>
+                  <NAME>.*</NAME>
+                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
                 </AND>
               </match>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*:layout_height</NAME>
-                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
-                </AND>
-              </match>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*:layout_.*</NAME>
-                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
-                </AND>
-              </match>
-              <order>BY_NAME</order>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*:width</NAME>
-                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
-                </AND>
-              </match>
-              <order>BY_NAME</order>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*:height</NAME>
-                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
-                </AND>
-              </match>
-              <order>BY_NAME</order>
-            </rule>
-          </section>
-          <section>
-            <rule>
-              <match>
-                <AND>
-                  <NAME>.*</NAME>
-                  <XML_NAMESPACE>http://schemas.android.com/apk/res/android</XML_NAMESPACE>
-                </AND>
-              </match>
-              <order>BY_NAME</order>
+              <order>ANDROID_ATTRIBUTE_ORDER</order>
             </rule>
           </section>
           <section>
@@ -226,6 +174,7 @@
               <match>
                 <AND>
                   <NAME>.*</NAME>
+                  <XML_ATTRIBUTE />
                   <XML_NAMESPACE>.*</XML_NAMESPACE>
                 </AND>
               </match>

bramble-android/build.gradle

@@ -5,23 +5,31 @@ apply plugin: 'witness'
 apply from: 'witness.gradle'
 
 android {
-	compileSdkVersion 28
-	buildToolsVersion '28.0.3'
+	compileSdkVersion 29
+	buildToolsVersion '29.0.2'
 
 	defaultConfig {
-		minSdkVersion 14
-		targetSdkVersion 26
-		versionCode 10107
-		versionName "1.1.7"
+		minSdkVersion 16
+		targetSdkVersion 28
+		versionCode 10205
+		versionName "1.2.5"
 		consumerProguardFiles 'proguard-rules.txt'
 
-		testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
 	}
 
 	compileOptions {
 		sourceCompatibility JavaVersion.VERSION_1_8
 		targetCompatibility JavaVersion.VERSION_1_8
 	}
+
+	lintOptions {
+		// FIXME
+		warning "LintError"
+		warning "InvalidPackage"
+		warning "MissingPermission"
+		warning "InlinedApi", "ObsoleteSdkInt", "Override", "NewApi", "UnusedAttribute"
+	}
 }
 
 configurations {
@@ -30,10 +38,10 @@ configurations {
 
 dependencies {
 	implementation project(path: ':bramble-core', configuration: 'default')
-	tor 'org.briarproject:tor-android:0.3.5.8@zip'
-	tor 'org.briarproject:obfs4proxy-android:0.0.9@zip'
+	tor 'org.briarproject:tor-android:0.3.5.9@zip'
+	tor 'org.briarproject:obfs4proxy-android:0.0.11-2@zip'
 
-	annotationProcessor 'com.google.dagger:dagger-compiler:2.22.1'
+	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 
 	compileOnly 'javax.annotation:jsr250-api:1.0'
 
@@ -59,6 +67,8 @@ task unpackTorBinaries {
 		copy {
 			from configurations.tor.collect { zipTree(it) }
 			into torBinariesDir
+			// TODO: Remove after next Tor upgrade, which won't include non-PIE binaries
+			include 'geoip.zip', '*_pie.zip'
 		}
 	}
 	dependsOn cleanTorBinaries

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

@@ -11,4 +11,14 @@ public interface BrambleAndroidEagerSingletons {
 	void inject(AndroidNetworkModule.EagerSingletons init);
 
 	void inject(ReportingModule.EagerSingletons init);
+
+	class Helper {
+
+		public static void injectEagerSingletons(
+				BrambleAndroidEagerSingletons c) {
+			c.inject(new AndroidBatteryModule.EagerSingletons());
+			c.inject(new AndroidNetworkModule.EagerSingletons());
+			c.inject(new ReportingModule.EagerSingletons());
+		}
+	}
 }

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

@@ -18,10 +18,4 @@ import dagger.Module;
 		SocksModule.class
 })
 public class BrambleAndroidModule {
-
-	public static void initEagerSingletons(BrambleAndroidEagerSingletons c) {
-		c.inject(new AndroidBatteryModule.EagerSingletons());
-		c.inject(new AndroidNetworkModule.EagerSingletons());
-		c.inject(new ReportingModule.EagerSingletons());
-	}
 }

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

@@ -16,6 +16,7 @@ import java.util.Set;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
 import javax.inject.Inject;
 
 import static android.os.Build.VERSION.SDK_INT;
@@ -29,8 +30,6 @@ class AndroidAccountManager extends AccountManagerImpl
 	private static final Logger LOG =
 			Logger.getLogger(AndroidAccountManager.class.getName());
 
-	private static final String PREF_DB_KEY = "key";
-
 	protected final Context appContext;
 	private final SharedPreferences prefs;
 
@@ -53,36 +52,6 @@ class AndroidAccountManager extends AccountManagerImpl
 		return exists;
 	}
 
-	// Locking: stateChangeLock
-	@Override
-	@Nullable
-	protected String loadEncryptedDatabaseKey() {
-		String key = getDatabaseKeyFromPreferences();
-		if (key == null) key = super.loadEncryptedDatabaseKey();
-		else migrateDatabaseKeyToFile(key);
-		return key;
-	}
-
-	// Locking: stateChangeLock
-	@Nullable
-	private String getDatabaseKeyFromPreferences() {
-		String key = prefs.getString(PREF_DB_KEY, null);
-		if (key == null) LOG.info("No database key in preferences");
-		else LOG.info("Found database key in preferences");
-		return key;
-	}
-
-	// Locking: stateChangeLock
-	private void migrateDatabaseKeyToFile(String key) {
-		if (storeEncryptedDatabaseKey(key)) {
-			if (prefs.edit().remove(PREF_DB_KEY).commit())
-				LOG.info("Database key migrated to file");
-			else LOG.warning("Database key not removed from preferences");
-		} else {
-			LOG.warning("Database key not migrated to file");
-		}
-	}
-
 	@Override
 	public void deleteAccount() {
 		synchronized (stateChangeLock) {
@@ -105,7 +74,7 @@ class AndroidAccountManager extends AccountManagerImpl
 		return PreferenceManager.getDefaultSharedPreferences(appContext);
 	}
 
-	// Locking: stateChangeLock
+	@GuardedBy("stateChangeLock")
 	private void deleteAppData(SharedPreferences... clear) {
 		// Clear and commit shared preferences
 		for (SharedPreferences prefs : clear) {

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

@@ -1,7 +1,6 @@
 package org.briarproject.bramble.plugin.tor;
 
 import android.content.Context;
-import android.os.Build;
 
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.event.EventBus;
@@ -89,9 +88,15 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 		// Check that we have a Tor binary for this architecture
 		String architecture = null;
 		for (String abi : AndroidUtils.getSupportedArchitectures()) {
-			if (abi.startsWith("x86")) {
+			if (abi.startsWith("x86_64")) {
+				architecture = "x86_64";
+				break;
+			} else if (abi.startsWith("x86")) {
 				architecture = "x86";
 				break;
+			} else if (abi.startsWith("arm64")) {
+				architecture = "arm64";
+				break;
 			} else if (abi.startsWith("armeabi")) {
 				architecture = "arm";
 				break;
@@ -101,8 +106,8 @@ public class AndroidTorPluginFactory implements DuplexPluginFactory {
 			LOG.info("Tor is not supported on this architecture");
 			return null;
 		}
-		// Use position-independent executable for SDK >= 16
-		if (Build.VERSION.SDK_INT >= 16) architecture += "_pie";
+		// Use position-independent executable
+		architecture += "_pie";
 
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);

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

@@ -23,6 +23,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static android.content.Context.WIFI_SERVICE;
+import static android.os.Build.VERSION.SDK_INT;
 import static android.provider.Settings.Secure.ANDROID_ID;
 
 @Immutable
@@ -74,8 +75,7 @@ class AndroidSecureRandomProvider extends UnixSecureRandomProvider {
 		// Silence strict mode
 		StrictMode.ThreadPolicy tp = StrictMode.allowThreadDiskWrites();
 		super.writeSeed();
-		if (Build.VERSION.SDK_INT >= 16 && Build.VERSION.SDK_INT <= 18)
-			applyOpenSslFix();
+		if (SDK_INT <= 18) applyOpenSslFix();
 		StrictMode.setThreadPolicy(tp);
 	}
 

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

@@ -6,15 +6,25 @@ import android.content.Context;
 import android.os.Build;
 import android.provider.Settings;
 
+import org.briarproject.bramble.api.Pair;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
 import java.io.File;
+import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 
+import javax.annotation.Nullable;
+
 import static android.content.Context.MODE_PRIVATE;
 import static android.os.Build.VERSION.SDK_INT;
+import static java.util.Arrays.asList;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
 
+@NotNullByDefault
 public class AndroidUtils {
 
 	// Fake Bluetooth address returned by BluetoothAdapter on API 23 and later
@@ -22,11 +32,10 @@ public class AndroidUtils {
 
 	private static final String STORED_REPORTS = "dev-reports";
 
-	@SuppressWarnings("deprecation")
 	public static Collection<String> getSupportedArchitectures() {
 		List<String> abis = new ArrayList<>();
 		if (SDK_INT >= 21) {
-			abis.addAll(Arrays.asList(Build.SUPPORTED_ABIS));
+			abis.addAll(asList(Build.SUPPORTED_ABIS));
 		} else {
 			abis.add(Build.CPU_ABI);
 			if (Build.CPU_ABI2 != null) abis.add(Build.CPU_ABI2);
@@ -36,25 +45,76 @@ public class AndroidUtils {
 
 	public static String getBluetoothAddress(Context ctx,
 			BluetoothAdapter adapter) {
+		return getBluetoothAddressAndMethod(ctx, adapter).getFirst();
+	}
+
+	public static Pair<String, String> getBluetoothAddressAndMethod(Context ctx,
+			BluetoothAdapter adapter) {
 		// Return the adapter's address if it's valid and not fake
 		@SuppressLint("HardwareIds")
 		String address = adapter.getAddress();
-		if (isValidBluetoothAddress(address)) return address;
+		if (isValidBluetoothAddress(address)) {
+			return new Pair<>(address, "adapter");
+		}
 		// Return the address from settings if it's valid and not fake
 		address = Settings.Secure.getString(ctx.getContentResolver(),
 				"bluetooth_address");
-		if (isValidBluetoothAddress(address)) return address;
+		if (isValidBluetoothAddress(address)) {
+			return new Pair<>(address, "settings");
+		}
+		// Try to get the address via reflection
+		address = getBluetoothAddressByReflection(adapter);
+		if (isValidBluetoothAddress(address)) {
+			return new Pair<>(requireNonNull(address), "reflection");
+		}
 		// Let the caller know we can't find the address
-		return "";
+		return new Pair<>("", "");
 	}
 
-	private static boolean isValidBluetoothAddress(String address) {
+	private static boolean isValidBluetoothAddress(@Nullable String address) {
 		return !StringUtils.isNullOrEmpty(address)
 				&& BluetoothAdapter.checkBluetoothAddress(address)
 				&& !address.equals(FAKE_BLUETOOTH_ADDRESS);
 	}
 
+	@Nullable
+	private static String getBluetoothAddressByReflection(
+			BluetoothAdapter adapter) {
+		try {
+			Field mServiceField =
+					adapter.getClass().getDeclaredField("mService");
+			mServiceField.setAccessible(true);
+			Object mService = mServiceField.get(adapter);
+			// mService may be null when Bluetooth is disabled
+			if (mService == null) throw new NoSuchFieldException();
+			Method getAddressMethod =
+					mService.getClass().getMethod("getAddress");
+			return (String) getAddressMethod.invoke(mService);
+		} catch (NoSuchFieldException e) {
+			return null;
+		} catch (IllegalAccessException e) {
+			return null;
+		} catch (NoSuchMethodException e) {
+			return null;
+		} catch (InvocationTargetException e) {
+			return null;
+		} catch (SecurityException e) {
+			return null;
+		}
+	}
+
 	public static File getReportDir(Context ctx) {
 		return ctx.getDir(STORED_REPORTS, MODE_PRIVATE);
 	}
+
+	/**
+	 * Returns an array of supported content types for image attachments.
+	 * GIFs can't be compressed on API < 24 so they're not supported.
+	 * <p>
+	 * TODO: Remove this restriction when large message support is added
+	 */
+	public static String[] getSupportedImageContentTypes() {
+		if (SDK_INT < 24) return new String[] {"image/jpeg", "image/png"};
+		else return new String[] {"image/jpeg", "image/png", "image/gif"};
+	}
 }

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

@@ -16,13 +16,10 @@ import org.junit.Test;
 
 import java.io.File;
 
-import static junit.framework.Assert.assertEquals;
 import static junit.framework.Assert.assertFalse;
 import static junit.framework.Assert.assertTrue;
 import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
-import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
 import static org.briarproject.bramble.test.TestUtils.getTestDirectory;
-import static org.briarproject.bramble.util.StringUtils.toHexString;
 
 public class AndroidAccountManagerTest extends BrambleMockTestCase {
 
@@ -40,11 +37,8 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 	private final Application app;
 	private final ApplicationInfo applicationInfo;
 
-	private final String encryptedKeyHex = toHexString(getRandomBytes(123));
 	private final File testDir = getTestDirectory();
 	private final File keyDir = new File(testDir, "key");
-	private final File keyFile = new File(keyDir, "db.key");
-	private final File keyBackupFile = new File(keyDir, "db.key.bak");
 	private final File dbDir = new File(testDir, "db");
 
 	private AndroidAccountManager accountManager;
@@ -75,29 +69,6 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 		};
 	}
 
-	@Test
-	public void testDbKeyIsMigratedFromPreferencesToFile() {
-		context.checking(new Expectations() {{
-			oneOf(prefs).getString("key", null);
-			will(returnValue(encryptedKeyHex));
-			oneOf(prefs).edit();
-			will(returnValue(editor));
-			oneOf(editor).remove("key");
-			will(returnValue(editor));
-			oneOf(editor).commit();
-			will(returnValue(true));
-		}});
-
-		assertFalse(keyFile.exists());
-		assertFalse(keyBackupFile.exists());
-
-		assertEquals(encryptedKeyHex,
-				accountManager.loadEncryptedDatabaseKey());
-
-		assertTrue(keyFile.exists());
-		assertTrue(keyBackupFile.exists());
-	}
-
 	@Test
 	public void testDeleteAccountClearsSharedPrefsAndDeletesFiles()
 			throws Exception {

bramble-android/witness.gradle

@@ -1,44 +1,46 @@
 dependencyVerification {
     verify = [
         'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
-        'com.android.tools.analytics-library:protos:26.4.0:protos-26.4.0.jar:ad760915586797d39319f402837b378bff3bb4ed583e3e0c48c965631fb2135f',
-        'com.android.tools.analytics-library:shared:26.4.0:shared-26.4.0.jar:1332106a905d48909c81268c9e414946de3e83487db394c6073b0a9b5c3d0ed2',
-        'com.android.tools.analytics-library:tracker:26.4.0:tracker-26.4.0.jar:d0020cfbfd4cd75935f2972d6a24089840d4a10df6f3ef2a796093217dd37796',
-        'com.android.tools.build:apksig:3.4.0:apksig-3.4.0.jar:91d5a1866139c69756280355a6f61b4d619d0516841580114f45a10f2177327e',
-        'com.android.tools.build:apkzlib:3.4.0:apkzlib-3.4.0.jar:8653c85f5fdf1dde840e8b8af7396aeb79c34b66e541b5860059616006535592',
-        'com.android.tools.build:builder-model:3.4.0:builder-model-3.4.0.jar:a88f138124a9f016a70bcb4760359a502f65c7deed56507ee4014f4dd9ea853b',
-        'com.android.tools.build:builder-test-api:3.4.0:builder-test-api-3.4.0.jar:31089ab1ec19ca7687a010867d2f3807513c805b8226979706f4247b5d4df26f',
-        'com.android.tools.build:builder:3.4.0:builder-3.4.0.jar:476221b5203a7f50089bf185ed95000a34b6f5020ef0a17815afd58606922679',
-        'com.android.tools.build:gradle-api:3.4.0:gradle-api-3.4.0.jar:215eca38f6719213c2f492b4d622cdd11676c66c9871f8a2aed0c66d00175628',
-        'com.android.tools.build:manifest-merger:26.4.0:manifest-merger-26.4.0.jar:29e45e690dedd165035e97c21c2ca94d0bd4ec16b6b210daa26669a582b6f220',
-        'com.android.tools.ddms:ddmlib:26.4.0:ddmlib-26.4.0.jar:93f56fe4630c3166adbd6c51d7bb602d96abb91b07ba5b1165fdcd071e88c940',
-        'com.android.tools.external.com-intellij:intellij-core:26.4.0:intellij-core-26.4.0.jar:30cb0e879d4424de9677a50b537fb628636b4a50f5470af5e52437980c41421f',
-        'com.android.tools.external.com-intellij:kotlin-compiler:26.4.0:kotlin-compiler-26.4.0.jar:dd1fe225c31a0e012dc025336363a5b783e2c5c20ffb69e77f8f57e89420d998',
-        'com.android.tools.external.org-jetbrains:uast:26.4.0:uast-26.4.0.jar:f25f3285b775a983327583ff6584dea54e447813ef69e0ce08b05a45b5f4aab0',
-        'com.android.tools.layoutlib:layoutlib-api:26.4.0:layoutlib-api-26.4.0.jar:52128f5cf293b224072be361919bfd416e59480ab7264ddcdbbf046b0d7a12e3',
-        'com.android.tools.lint:lint-api:26.4.0:lint-api-26.4.0.jar:fdb8fca8ae4c254f438338d03d72605e00ed106f2d5550405af41ca1c8509401',
-        'com.android.tools.lint:lint-checks:26.4.0:lint-checks-26.4.0.jar:4ff52d40488cd3e22b9c6b2eb67784e0c3269d0b42ef9d17689cd75a7b2bceb4',
-        'com.android.tools.lint:lint-gradle-api:26.4.0:lint-gradle-api-26.4.0.jar:714b7a85c7d2aa10daeab16e969fe7530c659d0728a7f24021da456870418d0f',
-        'com.android.tools.lint:lint-gradle:26.4.0:lint-gradle-26.4.0.jar:b8c130d273f522388734457e1b96790f41528fcec6fda9e8eaa4e4d95a07cfbb',
-        'com.android.tools.lint:lint:26.4.0:lint-26.4.0.jar:83aa062fb0405b60ed358d858c8c2955e1bae44a455b498068c6a60988755f00',
-        'com.android.tools:annotations:26.4.0:annotations-26.4.0.jar:a7955b8e19c3a2a861d6faa43a58b7c0d46ea9112188ee3e235c6f9f439ecc1a',
-        'com.android.tools:common:26.4.0:common-26.4.0.jar:ea40b94b3c1284ea7700f011388e2906a8363a66abd902891722b3c557984852',
-        'com.android.tools:dvlib:26.4.0:dvlib-26.4.0.jar:23af89c535b01ba36ceed1b6b309b672814eba624e643cd7dedf0519edad50cc',
-        'com.android.tools:repository:26.4.0:repository-26.4.0.jar:3d1763ab46199374dc6d94129bba11c70f1d5857e2c81a3ac4898abca40b176b',
-        'com.android.tools:sdk-common:26.4.0:sdk-common-26.4.0.jar:78a522525b30ffc6b7bf1299c831d24ce385f68a9f4878f8f752e9baefa31b0f',
-        'com.android.tools:sdklib:26.4.0:sdklib-26.4.0.jar:b854c23892013a326d761cf071c72cf3e038ed0469d10f4a356829fa56e4c132',
-        'com.google.code.findbugs:jsr305:1.3.9:jsr305-1.3.9.jar:905721a0eea90a81534abb7ee6ef4ea2e5e645fa1def0a5cd88402df1b46c9ed',
+        'com.android.tools.analytics-library:protos:26.5.1:protos-26.5.1.jar:8dde1130725461fe827f2a343d353f2b51e8870661fc860d7d5ebddb097ead4e',
+        'com.android.tools.analytics-library:shared:26.5.1:shared-26.5.1.jar:ccc2f3b00ec17b11401610ba68553544fc8fc517120e84439ac6eb86b875e18d',
+        'com.android.tools.analytics-library:tracker:26.5.1:tracker-26.5.1.jar:3a76984c0fe2e847ca7a8b35b4780ef0447a9d1666946cb8e60466318e0ab5ae',
+        'com.android.tools.build:aapt2-proto:0.4.0:aapt2-proto-0.4.0.jar:fac0435e08898f89eeeb9ca236bea707155ff816c12205ced285ad53604133ca',
+        'com.android.tools.build:apksig:3.5.1:apksig-3.5.1.jar:1fd33e7f009a2a0da766cfeec4211a09f548034b015c289a66d75dd8a9302f4a',
+        'com.android.tools.build:apkzlib:3.5.1:apkzlib-3.5.1.jar:9f330167cbe973b7db407692f74f4f6453b7ffa5f2048934b06280c2ceee60fa',
+        'com.android.tools.build:builder-model:3.5.1:builder-model-3.5.1.jar:39ea3c82b76b6e0c9f9fa88d93e0edc1dd4a0f1dfae0ef6fbf2d451da47e5450',
+        'com.android.tools.build:builder-test-api:3.5.1:builder-test-api-3.5.1.jar:a1b59305584cbcaa078fdc9cfb80871012755b822dd32e8da19add6f7bbcb762',
+        'com.android.tools.build:builder:3.5.1:builder-3.5.1.jar:e3a8d382434c5f60990730c4719fc814e85a898a33a1e96c1df8d627d3c6eea6',
+        'com.android.tools.build:gradle-api:3.5.1:gradle-api-3.5.1.jar:be9b41859bace11998f66b04ed944f87e413f3ad6da3c4665587699da125addc',
+        'com.android.tools.build:manifest-merger:26.5.1:manifest-merger-26.5.1.jar:dcad9ecb967251f4d750f55a4204a2b400e8fbfe5cb930a1d0d5dbe10ae8bdfc',
+        'com.android.tools.ddms:ddmlib:26.5.1:ddmlib-26.5.1.jar:b081aef2a4ed3f4d47cae4cdb128469735f25a114e026d37123bf9ffdec742a8',
+        'com.android.tools.external.com-intellij:intellij-core:26.5.1:intellij-core-26.5.1.jar:20eced30adc124805bd93488d9cd9d3e33e6bf7b48e9fe5a703d4983f894d450',
+        'com.android.tools.external.com-intellij:kotlin-compiler:26.5.1:kotlin-compiler-26.5.1.jar:5aed762dd54875b77ae7018d97c05756ff0c5b9fd02ec595dd396ccd14cc22cb',
+        'com.android.tools.external.org-jetbrains:uast:26.5.1:uast-26.5.1.jar:4bc8653d6c0943f40fee963a149e36c6baa45683d2530968a13f5007e3c40740',
+        'com.android.tools.layoutlib:layoutlib-api:26.5.1:layoutlib-api-26.5.1.jar:88732f11396c427273e515d23042e35633f4fe4295528a99b866aa2adf0efd9c',
+        'com.android.tools.lint:lint-api:26.5.1:lint-api-26.5.1.jar:ec33fcd72bfaf70dd841e03fbfd93f109c2e575aec146067c606689c3972f0de',
+        'com.android.tools.lint:lint-checks:26.5.1:lint-checks-26.5.1.jar:a1b9607d484aaae7a71dcecdc76f8003d8239af226c776894a2cf63f9e6c60d7',
+        'com.android.tools.lint:lint-gradle-api:26.5.1:lint-gradle-api-26.5.1.jar:82453fd98a8394cc84ed995c04d2cd744abd1d6589403427ba7eef53115406f3',
+        'com.android.tools.lint:lint-gradle:26.5.1:lint-gradle-26.5.1.jar:59465b56cf7db77c656d5f8195d721c3d48b6bdd0502d774de335bfe4baff00b',
+        'com.android.tools.lint:lint:26.5.1:lint-26.5.1.jar:336e4b04ec6f8b0f25879131b7a7862d77df83a1879ee5b71be26128755f8e2e',
+        'com.android.tools:annotations:26.5.1:annotations-26.5.1.jar:2c43c82f8c59d8f7a61e3239e1a2dc9f69dc342ec09af9b7c9f69b25337c0b6e',
+        'com.android.tools:common:26.5.1:common-26.5.1.jar:eccfa54486ed54c4e3123cc42195d023bd0dd21bcd2f0e4868e8c6fc70f8ef6b',
+        'com.android.tools:dvlib:26.5.1:dvlib-26.5.1.jar:46f93ad498b4756e7d867d2fe38c38890a80e7407a4ae459e4a8c8d5c5aeacfe',
+        'com.android.tools:repository:26.5.1:repository-26.5.1.jar:2b3ee791aa4c3e8ce60498c161a27ca7228816fc630eed4d9f25f2f36a106dce',
+        'com.android.tools:sdk-common:26.5.1:sdk-common-26.5.1.jar:365f749676c3574676fd465177c8a492f340816db2b520d6ed114d3b6e77bea7',
+        'com.android.tools:sdklib:26.5.1:sdklib-26.5.1.jar:007da104afb27c8c682a1628023fe9ec438249c8d15ef0fd6624c5bb8e23b696',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
-        'com.google.code.gson:gson:2.8.0:gson-2.8.0.jar:c6221763bd79c4f1c3dc7f750b5f29a0bb38b367b81314c4f71896e340c40825',
-        'com.google.dagger:dagger-compiler:2.22.1:dagger-compiler-2.22.1.jar:e5f28302cbe70a79d3620cddebfb8ec0736814f3980ffe1e673bfe3342f507d3',
-        'com.google.dagger:dagger-producers:2.22.1:dagger-producers-2.22.1.jar:f834a0082014213a68ff06a0f048d750178d02196c58b0b15beb367d32b97e35',
-        'com.google.dagger:dagger-spi:2.22.1:dagger-spi-2.22.1.jar:4b0b922793b3bcb91b99fabb75dba77c68afd7ae4c5f0c4fd6ba681f0a291c7d',
-        'com.google.dagger:dagger:2.22.1:dagger-2.22.1.jar:329d4340f24c4f5717af016c097e90668bfea2a5376e6aa9964b01cef3fd241a',
-        'com.google.errorprone:error_prone_annotations:2.1.3:error_prone_annotations-2.1.3.jar:03d0329547c13da9e17c634d1049ea2ead093925e290567e1a364fd6b1fc7ff8',
+        'com.google.code.gson:gson:2.8.5:gson-2.8.5.jar:233a0149fc365c9f6edbd683cfe266b19bdc773be98eabdaf6b3c924b48e7d81',
+        'com.google.dagger:dagger-compiler:2.24:dagger-compiler-2.24.jar:3c5afb955fb188da485cb2c048eff37dce0e1530b9780a0f2f7187d16d1ccc1f',
+        'com.google.dagger:dagger-producers:2.24:dagger-producers-2.24.jar:f10f45b95191954d5d6b043fca9e62fb621d21bf70634b8f8476c7988b504c3a',
+        'com.google.dagger:dagger-spi:2.24:dagger-spi-2.24.jar:c038445d14dbcb4054e61bf49e05009edf26fce4fdc7ec1a9db544784f68e718',
+        'com.google.dagger:dagger:2.24:dagger-2.24.jar:550a6e46a6dfcdf1d764887b6090cea94f783327e50e5c73754f18facfc70b64',
+        'com.google.errorprone:error_prone_annotations:2.2.0:error_prone_annotations-2.2.0.jar:6ebd22ca1b9d8ec06d41de8d64e0596981d9607b42035f9ed374f9de271a481a',
         'com.google.errorprone:javac-shaded:9-dev-r4023-3:javac-shaded-9-dev-r4023-3.jar:65bfccf60986c47fbc17c9ebab0be626afc41741e0a6ec7109e0768817a36f30',
         'com.google.googlejavaformat:google-java-format:1.5:google-java-format-1.5.jar:aa19ad7850fb85178aa22f2fddb163b84d6ce4d0035872f30d4408195ca1144e',
-        'com.google.guava:guava:25.0-jre:guava-25.0-jre.jar:3fd4341776428c7e0e5c18a7c10de129475b69ab9d30aeafbb5c277bb6074fa9',
-        'com.google.guava:guava:26.0-jre:guava-26.0-jre.jar:a0e9cabad665bc20bcd2b01f108e5fc03f756e13aea80abaadb9f407033bea2c',
+        'com.google.guava:failureaccess:1.0.1:failureaccess-1.0.1.jar:a171ee4c734dd2da837e4b16be9df4661afab72a41adaf31eb84dfdaf936ca26',
+        'com.google.guava:guava:27.0.1-jre:guava-27.0.1-jre.jar:e1c814fd04492a27c38e0317eabeaa1b3e950ec8010239e400fe90ad6c9107b4',
+        'com.google.guava:guava:27.1-jre:guava-27.1-jre.jar:4a5aa70cc968a4d137e599ad37553e5cfeed2265e8c193476d7119036c536fe7',
+        'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava:listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:b372a037d4230aa57fbeffdef30fd6123f9c0c2db85d0aced00c91b974f33f99',
         'com.google.j2objc:j2objc-annotations:1.1:j2objc-annotations-1.1.jar:2994a7eb78f2710bd3d3bfb639b2c94e219cedac0d4d084d516e78c16dddecf6',
         'com.google.jimfs:jimfs:1.1:jimfs-1.1.jar:c4828e28d7c0a930af9387510b3bada7daa5c04d7c25a75c7b8b081f1c257ddd',
         'com.google.protobuf:protobuf-java:3.4.0:protobuf-java-3.4.0.jar:dce7e66b32456a1b1198da0caff3a8acb71548658391e798c79369241e6490a4',
@@ -55,6 +57,7 @@ dependencyVerification {
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'javax.xml.bind:jaxb-api:2.2.12-b140109.1041:jaxb-api-2.2.12-b140109.1041.jar:b5e60cd8b7b5ff01ce4a74c5dd008f4fbd14ced3495d0b47b85cfedc182211f2',
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
+        'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
         'net.sf.jopt-simple:jopt-simple:4.9:jopt-simple-4.9.jar:26c5856e954b5f864db76f13b86919b59c6eecf9fd930b96baa8884626baf2f5',
         'net.sf.kxml:kxml2:2.3.0:kxml2-2.3.0.jar:f264dd9f79a1fde10ce5ecc53221eff24be4c9331c830b7d52f2f08a7b633de2',
         'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
@@ -66,22 +69,22 @@ dependencyVerification {
         'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
         'org.bouncycastle:bcpkix-jdk15on:1.56:bcpkix-jdk15on-1.56.jar:7043dee4e9e7175e93e0b36f45b1ec1ecb893c5f755667e8b916eb8dd201c6ca',
         'org.bouncycastle:bcprov-jdk15on:1.56:bcprov-jdk15on-1.56.jar:963e1ee14f808ffb99897d848ddcdb28fa91ddda867eb18d303e82728f878349',
-        'org.briarproject:obfs4proxy-android:0.0.9:obfs4proxy-android-0.0.9.zip:9b7e9181535ea8d8bbe8ae6338e08cf4c5fc1e357a779393e0ce49586d459ae0',
-        'org.briarproject:tor-android:0.3.5.8:tor-android-0.3.5.8.zip:42a13a6f185be1a62f42e3f30ce66a3c099ac5ec890a65e7593111b65b44a54a',
+        'org.briarproject:obfs4proxy-android:0.0.11-2:obfs4proxy-android-0.0.11-2.zip:57e55cbe87aa2aac210fdbb6cd8cdeafe15f825406a08ebf77a8b787aa2c6a8a',
+        'org.briarproject:tor-android:0.3.5.9:tor-android-0.3.5.9.zip:853b0440feccd6904bd03e6b2de53a62ebcde1d58068beeadc447a7dff950bc8',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
         'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
         'org.codehaus.groovy:groovy-all:2.4.15:groovy-all-2.4.15.jar:51d6c4e71782e85674239189499854359d380fb75e1a703756e3aaa5b98a5af0',
-        'org.codehaus.mojo:animal-sniffer-annotations:1.14:animal-sniffer-annotations-1.14.jar:2068320bd6bad744c3673ab048f67e30bef8f518996fa380033556600669905d',
+        'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',
         'org.glassfish.jaxb:jaxb-core:2.2.11:jaxb-core-2.2.11.jar:37bcaee8ebb04362c8352a5bf6221b86967ecdab5164c696b10b9a2bb587b2aa',
         'org.glassfish.jaxb:jaxb-runtime:2.2.11:jaxb-runtime-2.2.11.jar:a874f2351cfba8e2946be3002d10c18a6da8f21b52ba2acf52f2b85d5520ed70',
         'org.glassfish.jaxb:txw2:2.2.11:txw2-2.2.11.jar:272a3ccad45a4511351920cd2a8633c53cab8d5220c7a92954da5526bb5eafea',
         'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
         'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
-        'org.jetbrains.kotlin:kotlin-reflect:1.3.21:kotlin-reflect-1.3.21.jar:a3065c822633191e0a3e3ee12a29bec234fc4b2864a6bb87ef48cce3e9e0c26a',
-        'org.jetbrains.kotlin:kotlin-stdlib-common:1.3.21:kotlin-stdlib-common-1.3.21.jar:cea61f7b611895e64f58569a9757fc0ab0d582f107211e1930e0ce2a0add52a7',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.21:kotlin-stdlib-jdk7-1.3.21.jar:a87875604fd42140da6938ae4d35ee61081f4482536efc6d2615b8b626a198af',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.21:kotlin-stdlib-jdk8-1.3.21.jar:5823ed66ac122a1c55442ebca5a209a843ccd87f562edc31a787f3d2e47f74d4',
-        'org.jetbrains.kotlin:kotlin-stdlib:1.3.21:kotlin-stdlib-1.3.21.jar:38ba2370d9f06f50433e06b2ca775b94473c2e2785f410926079ab793c72b034',
+        'org.jetbrains.kotlin:kotlin-reflect:1.3.50:kotlin-reflect-1.3.50.jar:64583199ea5a54aefd1bd1595288925f784226ee562d1dd279011c6075b3d7a4',
+        'org.jetbrains.kotlin:kotlin-stdlib-common:1.3.50:kotlin-stdlib-common-1.3.50.jar:8ce678e88e4ba018b66dacecf952471e4d7dfee156a8a819760a5a5ff29d323c',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.50:kotlin-stdlib-jdk7-1.3.50.jar:9a026639e76212f8d57b86d55b075394c2e009f1979110751d34c05c5f75d57b',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.50:kotlin-stdlib-jdk8-1.3.50.jar:1b351fb6e09c14b55525c74c1f4cf48942eae43c348b7bc764a5e6e423d4da0c',
+        'org.jetbrains.kotlin:kotlin-stdlib:1.3.50:kotlin-stdlib-1.3.50.jar:e6f05746ee0366d0b52825a090fac474dcf44082c9083bbb205bd16976488d6c',
         'org.jetbrains.trove4j:trove4j:20160824:trove4j-20160824.jar:1917871c8deb468307a584680c87a44572f5a8b0b98c6d397fc0f5f86596dbe7',
         'org.jetbrains:annotations:13.0:annotations-13.0.jar:ace2a10dc8e2d5fd34925ecac03e4988b2c0f851650c94b8cef49ba1bd111478',
         'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',

bramble-api/build.gradle

@@ -7,7 +7,7 @@ apply plugin: 'witness'
 apply from: 'witness.gradle'
 
 dependencies {
-	implementation "com.google.dagger:dagger:2.22.1"
+	implementation "com.google.dagger:dagger:2.24"
 	implementation 'com.google.code.findbugs:jsr305:3.0.2'
 
 	testImplementation 'junit:junit:4.12'

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

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.api;
+
+/**
+ * Interface for specifying which features are enabled in a build.
+ */
+public interface FeatureFlags {
+
+	boolean shouldEnableImageAttachments();
+}

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

@@ -25,7 +25,10 @@ public interface ClientHelper {
 			throws DbException, FormatException;
 
 	void addLocalMessage(Transaction txn, Message m, BdfDictionary metadata,
-			boolean shared) throws DbException, FormatException;
+			boolean shared, boolean temporary)
+			throws DbException, FormatException;
+
+	Message createMessage(GroupId g, long timestamp, byte[] body);
 
 	Message createMessage(GroupId g, long timestamp, BdfList body)
 			throws FormatException;
@@ -108,7 +111,7 @@ public interface ClientHelper {
 	Author parseAndValidateAuthor(BdfList author) throws FormatException;
 
 	PublicKey parseAndValidateAgreementPublicKey(byte[] publicKeyBytes)
-		throws FormatException;
+			throws FormatException;
 
 	TransportProperties parseAndValidateTransportProperties(
 			BdfDictionary properties) throws FormatException;

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

@@ -4,8 +4,10 @@ import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.UnsupportedVersionException;
 import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.db.ContactExistsException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.NoSuchContactException;
+import org.briarproject.bramble.api.db.PendingContactExistsException;
 import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
@@ -117,9 +119,14 @@ public interface ContactManager {
 	 * @throws FormatException If the link is invalid
 	 * @throws GeneralSecurityException If the pending contact's handshake
 	 * public key is invalid
+	 * @throws ContactExistsException If a contact with the same handshake
+	 * public key already exists
+	 * @throws PendingContactExistsException If a pending contact with the same
+	 * handshake public key already exists
 	 */
 	PendingContact addPendingContact(String link, String alias)
-			throws DbException, FormatException, GeneralSecurityException;
+			throws DbException, FormatException, GeneralSecurityException,
+			ContactExistsException, PendingContactExistsException;
 
 	/**
 	 * Returns the pending contact with the given ID.

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

@@ -3,6 +3,7 @@ package org.briarproject.bramble.api.contact;
 public enum PendingContactState {
 
 	WAITING_FOR_CONNECTION,
+	OFFLINE,
 	CONNECTING,
 	ADDING_CONTACT,
 	FAILED

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

@@ -132,17 +132,32 @@ public interface CryptoComponent {
 	 * storage. The encryption and authentication keys are derived from the
 	 * given password. The ciphertext will be decryptable using the same
 	 * password after the app restarts.
+	 *
+	 * @param keyStrengthener Used to strengthen the password-based key. If
+	 * null, the password-based key will not be strengthened
 	 */
-	byte[] encryptWithPassword(byte[] plaintext, String password);
+	byte[] encryptWithPassword(byte[] plaintext, String password,
+			@Nullable KeyStrengthener keyStrengthener);
 
 	/**
 	 * Decrypts and authenticates the given ciphertext that has been read from
 	 * storage. The encryption and authentication keys are derived from the
 	 * given password. Returns null if the ciphertext cannot be decrypted and
 	 * authenticated (for example, if the password is wrong).
+	 *
+	 * @param keyStrengthener Used to strengthen the password-based key. If
+	 * null, or if strengthening was not used when encrypting the ciphertext,
+	 * the password-based key will not be strengthened
 	 */
 	@Nullable
-	byte[] decryptWithPassword(byte[] ciphertext, String password);
+	byte[] decryptWithPassword(byte[] ciphertext, String password,
+			@Nullable KeyStrengthener keyStrengthener);
+
+	/**
+	 * Returns true if the given ciphertext was encrypted using a strengthened
+	 * key. The validity of the ciphertext is not checked.
+	 */
+	boolean isEncryptedWithStrengthenedKey(byte[] ciphertext);
 
 	/**
 	 * Encrypts the given plaintext to the given public key.

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

@@ -0,0 +1,23 @@
+package org.briarproject.bramble.api.crypto;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+/**
+ * Interface for strengthening a password-based key, for example by using a
+ * key stored in a key management service or hardware security module.
+ */
+@NotNullByDefault
+public interface KeyStrengthener {
+
+	/**
+	 * Returns true if the strengthener has been initialised.
+	 */
+	@SuppressWarnings("BooleanMethodIsAlwaysInverted")
+	boolean isInitialised();
+
+	/**
+	 * Initialises the strengthener if necessary and returns a strong key
+	 * derived from the given key.
+	 */
+	SecretKey strengthenKey(SecretKey k);
+}

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

@@ -29,6 +29,7 @@ import org.briarproject.bramble.api.transport.TransportKeySet;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.Collection;
+import java.util.List;
 import java.util.Map;
 
 import javax.annotation.Nullable;
@@ -77,12 +78,12 @@ public interface DatabaseComponent extends TransactionManager {
 	 * Stores a local message.
 	 */
 	void addLocalMessage(Transaction txn, Message m, Metadata meta,
-			boolean shared) throws DbException;
+			boolean shared, boolean temporary) throws DbException;
 
 	/**
 	 * Stores a pending contact.
 	 */
-	void addPendingContact(Transaction txn, PendingContact p)
+	void addPendingContact(Transaction txn, PendingContact p, AuthorId local)
 			throws DbException;
 
 	/**
@@ -427,6 +428,13 @@ public interface DatabaseComponent extends TransactionManager {
 	 */
 	Settings getSettings(Transaction txn, String namespace) throws DbException;
 
+	/**
+	 * Returns the versions of the sync protocol supported by the given contact.
+	 * <p/>
+	 * Read-only.
+	 */
+	List<Byte> getSyncVersions(Transaction txn, ContactId c) throws DbException;
+
 	/**
 	 * Returns all transport keys for the given transport.
 	 * <p/>
@@ -510,6 +518,12 @@ public interface DatabaseComponent extends TransactionManager {
 	void removePendingContact(Transaction txn, PendingContactId p)
 			throws DbException;
 
+	/**
+	 * Removes all temporary messages (and all associated state) from the
+	 * database.
+	 */
+	void removeTemporaryMessages(Transaction txn) throws DbException;
+
 	/**
 	 * Removes a transport (and all associated state) from the database.
 	 */
@@ -538,6 +552,11 @@ public interface DatabaseComponent extends TransactionManager {
 	void setGroupVisibility(Transaction txn, ContactId c, GroupId g,
 			Visibility v) throws DbException;
 
+	/**
+	 * Marks the given message as permanent, i.e. not temporary.
+	 */
+	void setMessagePermanent(Transaction txn, MessageId m) throws DbException;
+
 	/**
 	 * Marks the given message as shared.
 	 */
@@ -568,6 +587,12 @@ public interface DatabaseComponent extends TransactionManager {
 	void setReorderingWindow(Transaction txn, KeySetId k, TransportId t,
 			long timePeriod, long base, byte[] bitmap) throws DbException;
 
+	/**
+	 * Sets the versions of the sync protocol supported by the given contact.
+	 */
+	void setSyncVersions(Transaction txn, ContactId c, List<Byte> supported)
+			throws DbException;
+
 	/**
 	 * Marks the given transport keys as usable for outgoing streams.
 	 */

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

@@ -1,13 +1,29 @@
 package org.briarproject.bramble.api.db;
 
+import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.File;
 
+import javax.annotation.Nullable;
+
 @NotNullByDefault
 public interface DatabaseConfig {
 
+	/**
+	 * Returns the directory where the database stores its data.
+	 */
 	File getDatabaseDirectory();
 
+	/**
+	 * Returns the directory where the encrypted database key is stored.
+	 */
 	File getDatabaseKeyDirectory();
+
+	/**
+	 * Returns a {@link KeyStrengthener} for strengthening the encryption of
+	 * the database key, or null if no strengthener should be used.
+	 */
+	@Nullable
+	KeyStrengthener getKeyStrengthener();
 }

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

@@ -1,9 +1,21 @@
 package org.briarproject.bramble.api.db;
 
+import org.briarproject.bramble.api.contact.PendingContact;
+
 /**
  * Thrown when a duplicate pending contact is added to the database. This
  * exception may occur due to concurrent updates and does not indicate a
  * database error.
  */
 public class PendingContactExistsException extends DbException {
+
+	private final PendingContact pendingContact;
+
+	public PendingContactExistsException(PendingContact pendingContact) {
+		this.pendingContact = pendingContact;
+	}
+
+	public PendingContact getPendingContact() {
+		return pendingContact;
+	}
 }

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

@@ -1,10 +1,16 @@
 package org.briarproject.bramble.api.sync;
 
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
 import java.util.Collection;
 
+import javax.annotation.concurrent.Immutable;
+
 /**
  * A record acknowledging receipt of one or more {@link Message Messages}.
  */
+@Immutable
+@NotNullByDefault
 public class Ack {
 
 	private final Collection<MessageId> acked;

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

@@ -1,8 +1,14 @@
 package org.briarproject.bramble.api.sync;
 
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
 
+@Immutable
+@NotNullByDefault
 public class Message {
 
 	/**

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

@@ -1,10 +1,16 @@
 package org.briarproject.bramble.api.sync;
 
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
 import java.util.Collection;
 
+import javax.annotation.concurrent.Immutable;
+
 /**
  * A record offering the recipient one or more {@link Message Messages}.
  */
+@Immutable
+@NotNullByDefault
 public class Offer {
 
 	private final Collection<MessageId> offered;

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

@@ -9,5 +9,5 @@ public interface RecordTypes {
 	byte MESSAGE = 1;
 	byte OFFER = 2;
 	byte REQUEST = 3;
-
+	byte VERSIONS = 4;
 }

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

@@ -1,10 +1,16 @@
 package org.briarproject.bramble.api.sync;
 
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
 import java.util.Collection;
 
+import javax.annotation.concurrent.Immutable;
+
 /**
  * A record requesting one or more {@link Message Messages} from the recipient.
  */
+@Immutable
+@NotNullByDefault
 public class Request {
 
 	private final Collection<MessageId> requested;

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

@@ -2,6 +2,9 @@ package org.briarproject.bramble.api.sync;
 
 import org.briarproject.bramble.api.UniqueId;
 
+import java.util.List;
+
+import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.api.record.Record.MAX_RECORD_PAYLOAD_BYTES;
 
 public interface SyncConstants {
@@ -11,6 +14,11 @@ public interface SyncConstants {
 	 */
 	byte PROTOCOL_VERSION = 0;
 
+	/**
+	 * The versions of the sync protocol this peer supports.
+	 */
+	List<Byte> SUPPORTED_VERSIONS = singletonList(PROTOCOL_VERSION);
+
 	/**
 	 * The maximum length of a group descriptor in bytes.
 	 */
@@ -35,4 +43,10 @@ public interface SyncConstants {
 	 * The maximum number of message IDs in an ack, offer or request record.
 	 */
 	int MAX_MESSAGE_IDS = MAX_RECORD_PAYLOAD_BYTES / UniqueId.LENGTH;
+
+	/**
+	 * The maximum number of versions of the sync protocol a peer may support
+	 * simultaneously.
+	 */
+	int MAX_SUPPORTED_VERSIONS = 10;
 }

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

@@ -25,4 +25,7 @@ public interface SyncRecordReader {
 
 	Request readRequest() throws IOException;
 
+	boolean hasVersions() throws IOException;
+
+	Versions readVersions() throws IOException;
 }

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

@@ -15,5 +15,7 @@ public interface SyncRecordWriter {
 
 	void writeRequest(Request r) throws IOException;
 
+	void writeVersions(Versions v) throws IOException;
+
 	void flush() throws IOException;
 }

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

@@ -0,0 +1,26 @@
+package org.briarproject.bramble.api.sync;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.List;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * A record telling the recipient which versions of the sync protocol the
+ * sender supports.
+ */
+@Immutable
+@NotNullByDefault
+public class Versions {
+
+	private final List<Byte> supported;
+
+	public Versions(List<Byte> supported) {
+		this.supported = supported;
+	}
+
+	public List<Byte> getSupportedVersions() {
+		return supported;
+	}
+}

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

@@ -0,0 +1,34 @@
+package org.briarproject.bramble.api.sync.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.List;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when the versions of the sync protocol supported
+ * by a contact are updated.
+ */
+@Immutable
+@NotNullByDefault
+public class SyncVersionsUpdatedEvent extends Event {
+
+	private final ContactId contactId;
+	private final List<Byte> supported;
+
+	public SyncVersionsUpdatedEvent(ContactId contactId, List<Byte> supported) {
+		this.contactId = contactId;
+		this.supported = supported;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	public List<Byte> getSupportedVersions() {
+		return supported;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/versioning/ClientVersion.java

@@ -0,0 +1,63 @@
+package org.briarproject.bramble.api.versioning;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.ClientId;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class ClientVersion implements Comparable<ClientVersion> {
+
+	private final ClientMajorVersion majorVersion;
+	private final int minorVersion;
+
+	public ClientVersion(ClientMajorVersion majorVersion,
+			int minorVersion) {
+		this.majorVersion = majorVersion;
+		this.minorVersion = minorVersion;
+	}
+
+	public ClientVersion(ClientId clientId, int majorVersion,
+			int minorVersion) {
+		this(new ClientMajorVersion(clientId, majorVersion), minorVersion);
+	}
+
+	public ClientMajorVersion getClientMajorVersion() {
+		return majorVersion;
+	}
+
+	public ClientId getClientId() {
+		return majorVersion.getClientId();
+	}
+
+	public int getMajorVersion() {
+		return majorVersion.getMajorVersion();
+	}
+
+	public int getMinorVersion() {
+		return minorVersion;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (o instanceof ClientVersion) {
+			ClientVersion cv = (ClientVersion) o;
+			return majorVersion.equals(cv.majorVersion)
+					&& minorVersion == cv.minorVersion;
+		}
+		return false;
+	}
+
+	@Override
+	public int hashCode() {
+		return majorVersion.hashCode();
+	}
+
+	@Override
+	public int compareTo(ClientVersion cv) {
+		int compare = majorVersion.compareTo(cv.majorVersion);
+		if (compare != 0) return compare;
+		return minorVersion - cv.minorVersion;
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/versioning/event/ClientVersionUpdatedEvent.java

@@ -0,0 +1,34 @@
+package org.briarproject.bramble.api.versioning.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.versioning.ClientVersion;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when we receive a client versioning update from
+ * a contact.
+ */
+@Immutable
+@NotNullByDefault
+public class ClientVersionUpdatedEvent extends Event {
+
+	private final ContactId contactId;
+	private final ClientVersion clientVersion;
+
+	public ClientVersionUpdatedEvent(ContactId contactId,
+			ClientVersion clientVersion) {
+		this.contactId = contactId;
+		this.clientVersion = clientVersion;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	public ClientVersion getClientVersion() {
+		return clientVersion;
+	}
+}

bramble-api/witness.gradle

@@ -2,7 +2,7 @@ dependencyVerification {
     verify = [
         'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
-        'com.google.dagger:dagger:2.22.1:dagger-2.22.1.jar:329d4340f24c4f5717af016c097e90668bfea2a5376e6aa9964b01cef3fd241a',
+        'com.google.dagger:dagger:2.24:dagger-2.24.jar:550a6e46a6dfcdf1d764887b6090cea94f783327e50e5c73754f18facfc70b64',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
         'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',

bramble-core/build.gradle

@@ -17,7 +17,7 @@ dependencies {
 	implementation 'org.whispersystems:curve25519-java:0.5.0'
 	implementation 'org.briarproject:jtorctl:0.3'
 
-	annotationProcessor 'com.google.dagger:dagger-compiler:2.22.1'
+	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
 	testImplementation 'org.hsqldb:hsqldb:2.3.5' // The last version that supports Java 1.6
@@ -26,7 +26,7 @@ dependencies {
 	testImplementation "org.jmock:jmock-junit4:2.8.2"
 	testImplementation "org.jmock:jmock-legacy:2.8.2"
 
-	testAnnotationProcessor 'com.google.dagger:dagger-compiler:2.22.1'
+	testAnnotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 
 	signature 'org.codehaus.mojo.signature:java16:1.1@signature'
 }

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

@@ -39,18 +39,21 @@ public interface BrambleCoreEagerSingletons {
 
 	void inject(VersioningModule.EagerSingletons init);
 
-	default void injectBrambleCoreEagerSingletons() {
-		inject(new ContactModule.EagerSingletons());
-		inject(new CryptoExecutorModule.EagerSingletons());
-		inject(new DatabaseExecutorModule.EagerSingletons());
-		inject(new IdentityModule.EagerSingletons());
-		inject(new LifecycleModule.EagerSingletons());
-		inject(new RendezvousModule.EagerSingletons());
-		inject(new PluginModule.EagerSingletons());
-		inject(new PropertiesModule.EagerSingletons());
-		inject(new SystemModule.EagerSingletons());
-		inject(new TransportModule.EagerSingletons());
-		inject(new ValidationModule.EagerSingletons());
-		inject(new VersioningModule.EagerSingletons());
+	class Helper {
+
+		public static void injectEagerSingletons(BrambleCoreEagerSingletons c) {
+			c.inject(new ContactModule.EagerSingletons());
+			c.inject(new CryptoExecutorModule.EagerSingletons());
+			c.inject(new DatabaseExecutorModule.EagerSingletons());
+			c.inject(new IdentityModule.EagerSingletons());
+			c.inject(new LifecycleModule.EagerSingletons());
+			c.inject(new RendezvousModule.EagerSingletons());
+			c.inject(new PluginModule.EagerSingletons());
+			c.inject(new PropertiesModule.EagerSingletons());
+			c.inject(new SystemModule.EagerSingletons());
+			c.inject(new TransportModule.EagerSingletons());
+			c.inject(new ValidationModule.EagerSingletons());
+			c.inject(new VersioningModule.EagerSingletons());
+		}
 	}
 }

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

@@ -50,8 +50,4 @@ import dagger.Module;
 		VersioningModule.class
 })
 public class BrambleCoreModule {
-
-	public static void initEagerSingletons(BrambleCoreEagerSingletons c) {
-		c.injectBrambleCoreEagerSingletons();
-	}
 }

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

@@ -2,6 +2,7 @@ package org.briarproject.bramble.account;
 
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.identity.Identity;
@@ -19,6 +20,7 @@ import java.io.InputStreamReader;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
 import javax.inject.Inject;
 
 import static java.util.logging.Level.WARNING;
@@ -68,9 +70,10 @@ class AccountManagerImpl implements AccountManager {
 		return databaseKey;
 	}
 
-	// Locking: stateChangeLock
+	// Package access for testing
+	@GuardedBy("stateChangeLock")
 	@Nullable
-	protected String loadEncryptedDatabaseKey() {
+	String loadEncryptedDatabaseKey() {
 		String key = readDbKeyFromFile(dbKeyFile);
 		if (key == null) {
 			LOG.info("No database key in primary file");
@@ -83,7 +86,7 @@ class AccountManagerImpl implements AccountManager {
 		return key;
 	}
 
-	// Locking: stateChangeLock
+	@GuardedBy("stateChangeLock")
 	@Nullable
 	private String readDbKeyFromFile(File f) {
 		if (!f.exists()) {
@@ -102,8 +105,9 @@ class AccountManagerImpl implements AccountManager {
 		}
 	}
 
-	// Locking: stateChangeLock
-	protected boolean storeEncryptedDatabaseKey(String hex) {
+	// Package access for testing
+	@GuardedBy("stateChangeLock")
+	boolean storeEncryptedDatabaseKey(String hex) {
 		LOG.info("Storing database key in file");
 		// Create the directory if necessary
 		if (databaseConfig.getDatabaseKeyDirectory().mkdirs())
@@ -140,7 +144,7 @@ class AccountManagerImpl implements AccountManager {
 		}
 	}
 
-	// Locking: stateChangeLock
+	@GuardedBy("stateChangeLock")
 	private void writeDbKeyToFile(String key, File f) throws IOException {
 		FileOutputStream out = new FileOutputStream(f);
 		out.write(key.getBytes("UTF-8"));
@@ -170,10 +174,11 @@ class AccountManagerImpl implements AccountManager {
 		}
 	}
 
-	// Locking: stateChangeLock
+	@GuardedBy("stateChangeLock")
 	private boolean encryptAndStoreDatabaseKey(SecretKey key, String password) {
 		byte[] plaintext = key.getBytes();
-		byte[] ciphertext = crypto.encryptWithPassword(plaintext, password);
+		byte[] ciphertext = crypto.encryptWithPassword(plaintext, password,
+				databaseConfig.getKeyStrengthener());
 		return storeEncryptedDatabaseKey(toHexString(ciphertext));
 	}
 
@@ -197,7 +202,7 @@ class AccountManagerImpl implements AccountManager {
 		}
 	}
 
-	// Locking: stateChangeLock
+	@GuardedBy("stateChangeLock")
 	@Nullable
 	private SecretKey loadAndDecryptDatabaseKey(String password) {
 		String hex = loadEncryptedDatabaseKey();
@@ -206,12 +211,22 @@ class AccountManagerImpl implements AccountManager {
 			return null;
 		}
 		byte[] ciphertext = fromHexString(hex);
-		byte[] plaintext = crypto.decryptWithPassword(ciphertext, password);
+		KeyStrengthener keyStrengthener = databaseConfig.getKeyStrengthener();
+		byte[] plaintext = crypto.decryptWithPassword(ciphertext, password,
+				keyStrengthener);
 		if (plaintext == null) {
 			LOG.info("Failed to decrypt database key");
 			return null;
 		}
-		return new SecretKey(plaintext);
+		SecretKey key = new SecretKey(plaintext);
+		// If the DB key was encrypted with a weak key and a key strengthener
+		// is now available, re-encrypt the DB key with a strengthened key
+		if (keyStrengthener != null &&
+				!crypto.isEncryptedWithStrengthenedKey(ciphertext)) {
+			LOG.info("Re-encrypting database key with strengthened key");
+			encryptAndStoreDatabaseKey(key, password);
+		}
+		return key;
 	}
 
 	@Override

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

@@ -85,14 +85,21 @@ class ClientHelperImpl implements ClientHelper {
 	@Override
 	public void addLocalMessage(Message m, BdfDictionary metadata,
 			boolean shared) throws DbException, FormatException {
-		db.transaction(false, txn -> addLocalMessage(txn, m, metadata, shared));
+		db.transaction(false, txn -> addLocalMessage(txn, m, metadata, shared,
+				false));
 	}
 
 	@Override
 	public void addLocalMessage(Transaction txn, Message m,
-			BdfDictionary metadata, boolean shared)
+			BdfDictionary metadata, boolean shared, boolean temporary)
 			throws DbException, FormatException {
-		db.addLocalMessage(txn, m, metadataEncoder.encode(metadata), shared);
+		db.addLocalMessage(txn, m, metadataEncoder.encode(metadata), shared,
+				temporary);
+	}
+
+	@Override
+	public Message createMessage(GroupId g, long timestamp, byte[] body) {
+		return messageFactory.createMessage(g, timestamp, body);
 	}
 
 	@Override

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

@@ -139,7 +139,8 @@ class ContactManagerImpl implements ContactManager, EventListener {
 				pendingContactFactory.createPendingContact(link, alias);
 		Transaction txn = db.startTransaction(false);
 		try {
-			db.addPendingContact(txn, p);
+			AuthorId local = identityManager.getLocalAuthor(txn).getId();
+			db.addPendingContact(txn, p, local);
 			KeyPair ourKeyPair = identityManager.getHandshakeKeys(txn);
 			keyManager.addPendingContact(txn, p.getId(), p.getPublicKey(),
 					ourKeyPair);
@@ -147,7 +148,6 @@ class ContactManagerImpl implements ContactManager, EventListener {
 		} finally {
 			db.endTransaction(txn);
 		}
-		states.put(p.getId(), WAITING_FOR_CONNECTION);
 		return p;
 	}
 

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

@@ -9,6 +9,7 @@ import org.briarproject.bramble.api.crypto.AgreementPublicKey;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.KeyParser;
+import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
@@ -51,7 +52,8 @@ class CryptoComponentImpl implements CryptoComponent {
 	private static final int SIGNATURE_KEY_PAIR_BITS = 256;
 	private static final int STORAGE_IV_BYTES = 24; // 196 bits
 	private static final int PBKDF_SALT_BYTES = 32; // 256 bits
-	private static final int PBKDF_FORMAT_SCRYPT = 0;
+	private static final byte PBKDF_FORMAT_SCRYPT = 0;
+	private static final byte PBKDF_FORMAT_SCRYPT_STRENGTHENED = 1;
 
 	private final SecureRandom secureRandom;
 	private final PasswordBasedKdf passwordBasedKdf;
@@ -311,7 +313,8 @@ class CryptoComponentImpl implements CryptoComponent {
 	}
 
 	@Override
-	public byte[] encryptWithPassword(byte[] input, String password) {
+	public byte[] encryptWithPassword(byte[] input, String password,
+			@Nullable KeyStrengthener keyStrengthener) {
 		AuthenticatedCipher cipher = new XSalsa20Poly1305AuthenticatedCipher();
 		int macBytes = cipher.getMacBytes();
 		// Generate a random salt
@@ -319,8 +322,9 @@ class CryptoComponentImpl implements CryptoComponent {
 		secureRandom.nextBytes(salt);
 		// Calibrate the KDF
 		int cost = passwordBasedKdf.chooseCostParameter();
-		// Derive the key from the password
+		// Derive the encryption key from the password
 		SecretKey key = passwordBasedKdf.deriveKey(password, salt, cost);
+		if (keyStrengthener != null) key = keyStrengthener.strengthenKey(key);
 		// Generate a random IV
 		byte[] iv = new byte[STORAGE_IV_BYTES];
 		secureRandom.nextBytes(iv);
@@ -331,7 +335,9 @@ class CryptoComponentImpl implements CryptoComponent {
 		byte[] output = new byte[outputLen];
 		int outputOff = 0;
 		// Format version
-		output[outputOff] = PBKDF_FORMAT_SCRYPT;
+		byte formatVersion = keyStrengthener == null
+				? PBKDF_FORMAT_SCRYPT : PBKDF_FORMAT_SCRYPT_STRENGTHENED;
+		output[outputOff] = formatVersion;
 		outputOff++;
 		// Salt
 		arraycopy(salt, 0, output, outputOff, salt.length);
@@ -354,7 +360,8 @@ class CryptoComponentImpl implements CryptoComponent {
 
 	@Override
 	@Nullable
-	public byte[] decryptWithPassword(byte[] input, String password) {
+	public byte[] decryptWithPassword(byte[] input, String password,
+			@Nullable KeyStrengthener keyStrengthener) {
 		AuthenticatedCipher cipher = new XSalsa20Poly1305AuthenticatedCipher();
 		int macBytes = cipher.getMacBytes();
 		// The input contains the format version, salt, cost parameter, IV,
@@ -366,8 +373,11 @@ class CryptoComponentImpl implements CryptoComponent {
 		// Format version
 		byte formatVersion = input[inputOff];
 		inputOff++;
-		if (formatVersion != PBKDF_FORMAT_SCRYPT)
-			return null; // Unknown format
+		// Check whether we support this format version
+		if (formatVersion != PBKDF_FORMAT_SCRYPT &&
+				formatVersion != PBKDF_FORMAT_SCRYPT_STRENGTHENED) {
+			return null;
+		}
 		// Salt
 		byte[] salt = new byte[PBKDF_SALT_BYTES];
 		arraycopy(input, inputOff, salt, 0, salt.length);
@@ -381,8 +391,13 @@ class CryptoComponentImpl implements CryptoComponent {
 		byte[] iv = new byte[STORAGE_IV_BYTES];
 		arraycopy(input, inputOff, iv, 0, iv.length);
 		inputOff += iv.length;
-		// Derive the key from the password
+		// Derive the decryption key from the password
 		SecretKey key = passwordBasedKdf.deriveKey(password, salt, (int) cost);
+		if (formatVersion == PBKDF_FORMAT_SCRYPT_STRENGTHENED) {
+			if (keyStrengthener == null || !keyStrengthener.isInitialised())
+				return null; // Can't derive the same strengthened key
+			key = keyStrengthener.strengthenKey(key);
+		}
 		// Initialise the cipher
 		try {
 			cipher.init(false, key, iv);
@@ -400,6 +415,12 @@ class CryptoComponentImpl implements CryptoComponent {
 		}
 	}
 
+	@Override
+	public boolean isEncryptedWithStrengthenedKey(byte[] ciphertext) {
+		return ciphertext.length > 0 &&
+				ciphertext[0] == PBKDF_FORMAT_SCRYPT_STRENGTHENED;
+	}
+
 	@Override
 	public byte[] encryptToKey(PublicKey publicKey, byte[] plaintext) {
 		try {

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

@@ -33,6 +33,7 @@ import org.briarproject.bramble.api.transport.TransportKeySet;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
 import java.util.Collection;
+import java.util.List;
 import java.util.Map;
 
 import javax.annotation.Nullable;
@@ -115,7 +116,7 @@ interface Database<T> {
 	 * if the message was created locally.
 	 */
 	void addMessage(T txn, Message m, MessageState state, boolean shared,
-			@Nullable ContactId sender) throws DbException;
+			boolean temporary, @Nullable ContactId sender) throws DbException;
 
 	/**
 	 * Adds a dependency between two messages, where the dependent message is
@@ -266,6 +267,16 @@ interface Database<T> {
 	 */
 	Collection<ContactId> getContacts(T txn, AuthorId local) throws DbException;
 
+	/**
+	 * Returns the contact with the given {@code handshakePublicKey}
+	 * for the given local pseudonym or {@code null} if none exists.
+	 * <p/>
+	 * Read-only.
+	 */
+	@Nullable
+	Contact getContact(T txn, PublicKey handshakePublicKey, AuthorId local)
+			throws DbException;
+
 	/**
 	 * Returns the group with the given ID.
 	 * <p/>
@@ -528,6 +539,13 @@ interface Database<T> {
 	 */
 	Settings getSettings(T txn, String namespace) throws DbException;
 
+	/**
+	 * Returns the versions of the sync protocol supported by the given contact.
+	 * <p/>
+	 * Read-only.
+	 */
+	List<Byte> getSyncVersions(T txn, ContactId c) throws DbException;
+
 	/**
 	 * Returns all transport keys for the given transport.
 	 * <p/>
@@ -630,6 +648,12 @@ interface Database<T> {
 	 */
 	void removePendingContact(T txn, PendingContactId p) throws DbException;
 
+	/**
+	 * Removes all temporary messages (and all associated state) from the
+	 * database.
+	 */
+	void removeTemporaryMessages(T txn) throws DbException;
+
 	/**
 	 * Removes a transport (and all associated state) from the database.
 	 */
@@ -671,6 +695,11 @@ interface Database<T> {
 	void setHandshakeKeyPair(T txn, AuthorId local, PublicKey publicKey,
 			PrivateKey privateKey) throws DbException;
 
+	/**
+	 * Marks the given message as permanent, i.e. not temporary.
+	 */
+	void setMessagePermanent(T txn, MessageId m) throws DbException;
+
 	/**
 	 * Marks the given message as shared.
 	 */
@@ -689,6 +718,12 @@ interface Database<T> {
 	void setReorderingWindow(T txn, KeySetId k, TransportId t,
 			long timePeriod, long base, byte[] bitmap) throws DbException;
 
+	/**
+	 * Sets the versions of the sync protocol supported by the given contact.
+	 */
+	void setSyncVersions(T txn, ContactId c, List<Byte> supported)
+			throws DbException;
+
 	/**
 	 * Marks the given transport keys as usable for outgoing streams.
 	 */

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

@@ -65,6 +65,7 @@ import org.briarproject.bramble.api.sync.event.MessageToAckEvent;
 import org.briarproject.bramble.api.sync.event.MessageToRequestEvent;
 import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
 import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
+import org.briarproject.bramble.api.sync.event.SyncVersionsUpdatedEvent;
 import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.TransportKeySet;
@@ -273,13 +274,14 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 
 	@Override
 	public void addLocalMessage(Transaction transaction, Message m,
-			Metadata meta, boolean shared) throws DbException {
+			Metadata meta, boolean shared, boolean temporary)
+			throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsGroup(txn, m.getGroupId()))
 			throw new NoSuchGroupException();
 		if (!db.containsMessage(txn, m.getId())) {
-			db.addMessage(txn, m, DELIVERED, shared, null);
+			db.addMessage(txn, m, DELIVERED, shared, temporary, null);
 			transaction.attach(new MessageAddedEvent(m, null));
 			transaction.attach(new MessageStateChangedEvent(m.getId(), true,
 					DELIVERED));
@@ -289,12 +291,17 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public void addPendingContact(Transaction transaction, PendingContact p)
-			throws DbException {
+	public void addPendingContact(Transaction transaction, PendingContact p,
+			AuthorId local) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
-		if (db.containsPendingContact(txn, p.getId()))
-			throw new PendingContactExistsException();
+		Contact contact = db.getContact(txn, p.getPublicKey(), local);
+		if (contact != null)
+			throw new ContactExistsException(local, contact.getAuthor());
+		if (db.containsPendingContact(txn, p.getId())) {
+			PendingContact existing = db.getPendingContact(txn, p.getId());
+			throw new PendingContactExistsException(existing);
+		}
 		db.addPendingContact(txn, p);
 		transaction.attach(new PendingContactAddedEvent(p));
 	}
@@ -715,6 +722,15 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getSettings(txn, namespace);
 	}
 
+	@Override
+	public List<Byte> getSyncVersions(Transaction transaction, ContactId c)
+			throws DbException {
+		T txn = unbox(transaction);
+		if (!db.containsContact(txn, c))
+			throw new NoSuchContactException();
+		return db.getSyncVersions(txn, c);
+	}
+
 	@Override
 	public Collection<TransportKeySet> getTransportKeys(Transaction transaction,
 			TransportId t) throws DbException {
@@ -800,7 +816,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 				db.raiseSeenFlag(txn, c, m.getId());
 				db.raiseAckFlag(txn, c, m.getId());
 			} else {
-				db.addMessage(txn, m, UNKNOWN, false, c);
+				db.addMessage(txn, m, UNKNOWN, false, false, c);
 				transaction.attach(new MessageAddedEvent(m, c));
 			}
 			transaction.attach(new MessageToAckEvent(c));
@@ -908,6 +924,14 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		transaction.attach(new PendingContactRemovedEvent(p));
 	}
 
+	@Override
+	public void removeTemporaryMessages(Transaction transaction)
+			throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		db.removeTemporaryMessages(txn);
+	}
+
 	@Override
 	public void removeTransport(Transaction transaction, TransportId t)
 			throws DbException {
@@ -967,6 +991,16 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		transaction.attach(new GroupVisibilityUpdatedEvent(affected));
 	}
 
+	@Override
+	public void setMessagePermanent(Transaction transaction, MessageId m)
+			throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsMessage(txn, m))
+			throw new NoSuchMessageException();
+		db.setMessagePermanent(txn, m);
+	}
+
 	@Override
 	public void setMessageShared(Transaction transaction, MessageId m)
 			throws DbException {
@@ -975,8 +1009,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		if (!db.containsMessage(txn, m))
 			throw new NoSuchMessageException();
 		if (db.getMessageState(txn, m) != DELIVERED)
-			throw new IllegalArgumentException(
-					"Shared undelivered message");
+			throw new IllegalArgumentException("Shared undelivered message");
 		db.setMessageShared(txn, m);
 		transaction.attach(new MessageSharedEvent(m));
 	}
@@ -1028,6 +1061,17 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.setReorderingWindow(txn, k, t, timePeriod, base, bitmap);
 	}
 
+	@Override
+	public void setSyncVersions(Transaction transaction, ContactId c,
+			List<Byte> supported) throws DbException {
+		if (transaction.isReadOnly()) throw new IllegalArgumentException();
+		T txn = unbox(transaction);
+		if (!db.containsContact(txn, c))
+			throw new NoSuchContactException();
+		db.setSyncVersions(txn, c, supported);
+		transaction.attach(new SyncVersionsUpdatedEvent(c, supported));
+	}
+
 	@Override
 	public void setTransportKeysActive(Transaction transaction, TransportId t,
 			KeySetId k) throws DbException {

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

@@ -62,6 +62,7 @@ import java.util.concurrent.locks.ReentrantLock;
 import java.util.logging.Logger;
 
 import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
 
 import static java.sql.Types.BINARY;
 import static java.sql.Types.BOOLEAN;
@@ -97,7 +98,7 @@ import static org.briarproject.bramble.util.LogUtils.now;
 abstract class JdbcDatabase implements Database<Connection> {
 
 	// Package access for testing
-	static final int CODE_SCHEMA_VERSION = 45;
+	static final int CODE_SCHEMA_VERSION = 47;
 
 	// Time period offsets for incoming transport keys
 	private static final int OFFSET_PREV = -1;
@@ -134,6 +135,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " handshakePublicKey _BINARY," // Null if key is unknown
 					+ " localAuthorId _HASH NOT NULL,"
 					+ " verified BOOLEAN NOT NULL,"
+					+ " syncVersions _BINARY DEFAULT '00' NOT NULL,"
 					+ " PRIMARY KEY (contactId),"
 					+ " FOREIGN KEY (localAuthorId)"
 					+ " REFERENCES localAuthors (authorId)"
@@ -177,6 +179,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " timestamp BIGINT NOT NULL,"
 					+ " state INT NOT NULL,"
 					+ " shared BOOLEAN NOT NULL,"
+					+ " temporary BOOLEAN NOT NULL,"
 					+ " length INT NOT NULL,"
 					+ " raw BLOB," // Null if message has been deleted
 					+ " PRIMARY KEY (messageId),"
@@ -336,25 +339,26 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private static final Logger LOG =
 			getLogger(JdbcDatabase.class.getName());
 
-	// Different database libraries use different names for certain types
 	private final MessageFactory messageFactory;
 	private final Clock clock;
 	private final DatabaseTypes dbTypes;
 
-	// Locking: connectionsLock
+	private final Lock connectionsLock = new ReentrantLock();
+	private final Condition connectionsChanged = connectionsLock.newCondition();
+
+	@GuardedBy("connectionsLock")
 	private final LinkedList<Connection> connections = new LinkedList<>();
 
-	private int openConnections = 0; // Locking: connectionsLock
-	private boolean closed = false; // Locking: connectionsLock
+	@GuardedBy("connectionsLock")
+	private int openConnections = 0;
+	@GuardedBy("connectionsLock")
+	private boolean closed = false;
 
 	protected abstract Connection createConnection()
 			throws DbException, SQLException;
 
 	protected abstract void compactAndClose() throws DbException;
 
-	private final Lock connectionsLock = new ReentrantLock();
-	private final Condition connectionsChanged = connectionsLock.newCondition();
-
 	JdbcDatabase(DatabaseTypes databaseTypes, MessageFactory messageFactory,
 			Clock clock) {
 		this.dbTypes = databaseTypes;
@@ -457,7 +461,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 				new Migration41_42(dbTypes),
 				new Migration42_43(dbTypes),
 				new Migration43_44(dbTypes),
-				new Migration44_45()
+				new Migration44_45(),
+				new Migration45_46(),
+				new Migration46_47(dbTypes)
 		);
 	}
 
@@ -777,22 +783,23 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	@Override
 	public void addMessage(Connection txn, Message m, MessageState state,
-			boolean messageShared, @Nullable ContactId sender)
+			boolean shared, boolean temporary, @Nullable ContactId sender)
 			throws DbException {
 		PreparedStatement ps = null;
 		try {
 			String sql = "INSERT INTO messages (messageId, groupId, timestamp,"
-					+ " state, shared, length, raw)"
-					+ " VALUES (?, ?, ?, ?, ?, ?, ?)";
+					+ " state, shared, temporary, length, raw)"
+					+ " VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getId().getBytes());
 			ps.setBytes(2, m.getGroupId().getBytes());
 			ps.setLong(3, m.getTimestamp());
 			ps.setInt(4, state.getValue());
-			ps.setBoolean(5, messageShared);
+			ps.setBoolean(5, shared);
+			ps.setBoolean(6, temporary);
 			byte[] raw = messageFactory.getRawMessage(m);
-			ps.setInt(6, raw.length);
-			ps.setBytes(7, raw);
+			ps.setInt(7, raw.length);
+			ps.setBytes(8, raw);
 			int affected = ps.executeUpdate();
 			if (affected != 1) throw new DbStateException();
 			ps.close();
@@ -804,8 +811,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				boolean offered = removeOfferedMessage(txn, c, m.getId());
 				boolean seen = offered || c.equals(sender);
 				addStatus(txn, m.getId(), c, m.getGroupId(), m.getTimestamp(),
-						raw.length, state, e.getValue(), messageShared,
-						false, seen);
+						raw.length, state, e.getValue(), shared, false, seen);
 			}
 			// Update denormalised column in messageDependencies if dependency
 			// is in same group as dependent
@@ -1459,6 +1465,47 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Nullable
+	@Override
+	public Contact getContact(Connection txn, PublicKey handshakePublicKey,
+			AuthorId localAuthorId) throws DbException {
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			String sql = "SELECT contactId, authorId, formatVersion, name,"
+					+ " alias, publicKey, verified"
+					+ " FROM contacts"
+					+ " WHERE handshakePublicKey = ? AND localAuthorId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, handshakePublicKey.getEncoded());
+			ps.setBytes(2, localAuthorId.getBytes());
+			rs = ps.executeQuery();
+			if (!rs.next()) {
+				rs.close();
+				ps.close();
+				return null;
+			}
+			ContactId contactId = new ContactId(rs.getInt(1));
+			AuthorId authorId = new AuthorId(rs.getBytes(2));
+			int formatVersion = rs.getInt(3);
+			String name = rs.getString(4);
+			String alias = rs.getString(5);
+			PublicKey publicKey = new SignaturePublicKey(rs.getBytes(6));
+			boolean verified = rs.getBoolean(7);
+			if (rs.next()) throw new DbStateException();
+			rs.close();
+			ps.close();
+			Author author =
+					new Author(authorId, formatVersion, name, publicKey);
+			return new Contact(contactId, author, localAuthorId, alias,
+					handshakePublicKey, verified);
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public Group getGroup(Connection txn, GroupId g) throws DbException {
 		PreparedStatement ps = null;
@@ -2324,6 +2371,32 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public List<Byte> getSyncVersions(Connection txn, ContactId c)
+			throws DbException {
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			String sql = "SELECT syncVersions FROM contacts"
+					+ " WHERE contactId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setInt(1, c.getInt());
+			rs = ps.executeQuery();
+			if (!rs.next()) throw new DbStateException();
+			byte[] bytes = rs.getBytes(1);
+			List<Byte> supported = new ArrayList<>(bytes.length);
+			for (byte b : bytes) supported.add(b);
+			if (rs.next()) throw new DbStateException();
+			rs.close();
+			ps.close();
+			return supported;
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public Collection<TransportKeySet> getTransportKeys(Connection txn,
 			TransportId t) throws DbException {
@@ -2876,6 +2949,21 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public void removeTemporaryMessages(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			String sql = "DELETE FROM messages WHERE temporary = TRUE";
+			s = txn.createStatement();
+			int affected = s.executeUpdate(sql);
+			if (affected < 0) throw new DbStateException();
+			s.close();
+		} catch (SQLException e) {
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public void removeTransport(Connection txn, TransportId t)
 			throws DbException {
@@ -3021,6 +3109,24 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public void setMessagePermanent(Connection txn, MessageId m)
+			throws DbException {
+		PreparedStatement ps = null;
+		try {
+			String sql = "UPDATE messages SET temporary = FALSE"
+					+ " WHERE messageId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, m.getBytes());
+			int affected = ps.executeUpdate();
+			if (affected < 0 || affected > 1) throw new DbStateException();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public void setMessageShared(Connection txn, MessageId m)
 			throws DbException {
@@ -3124,6 +3230,29 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public void setSyncVersions(Connection txn, ContactId c,
+			List<Byte> supported) throws DbException {
+		PreparedStatement ps = null;
+		try {
+			String sql = "UPDATE contacts SET syncVersions = ?"
+					+ " WHERE contactId = ?";
+			ps = txn.prepareStatement(sql);
+			byte[] bytes = new byte[supported.size()];
+			for (int i = 0; i < bytes.length; i++) {
+				bytes[i] = supported.get(i);
+			}
+			ps.setBytes(1, bytes);
+			ps.setInt(2, c.getInt());
+			int affected = ps.executeUpdate();
+			if (affected < 0 || affected > 1) throw new DbStateException();
+			ps.close();
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public void setTransportKeysActive(Connection txn, TransportId t,
 			KeySetId k) throws DbException {

bramble-core/src/main/java/org/briarproject/bramble/db/Migration45_46.java

@@ -0,0 +1,40 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.db.DbException;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
+class Migration45_46 implements Migration<Connection> {
+
+	private static final Logger LOG = getLogger(Migration45_46.class.getName());
+
+	@Override
+	public int getStartVersion() {
+		return 45;
+	}
+
+	@Override
+	public int getEndVersion() {
+		return 46;
+	}
+
+	@Override
+	public void migrate(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			s = txn.createStatement();
+			s.execute("ALTER TABLE messages"
+					+ " ADD COLUMN temporary BOOLEAN DEFAULT FALSE NOT NULL");
+		} catch (SQLException e) {
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/db/Migration46_47.java

@@ -0,0 +1,47 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.db.DbException;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.logging.Logger;
+
+import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
+class Migration46_47 implements Migration<Connection> {
+
+	private static final Logger LOG = getLogger(Migration46_47.class.getName());
+
+	private final DatabaseTypes dbTypes;
+
+	Migration46_47(DatabaseTypes dbTypes) {
+		this.dbTypes = dbTypes;
+	}
+
+	@Override
+	public int getStartVersion() {
+		return 46;
+	}
+
+	@Override
+	public int getEndVersion() {
+		return 47;
+	}
+
+	@Override
+	public void migrate(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			s = txn.createStatement();
+			s.execute(dbTypes.replaceTypes("ALTER TABLE contacts"
+					+ " ADD COLUMN syncVersions"
+					+ " _BINARY DEFAULT '00' NOT NULL"));
+		} catch (SQLException e) {
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+}

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

@@ -107,8 +107,11 @@ class LifecycleManagerImpl implements LifecycleManager, MigrationListener {
 			else logDuration(LOG, "Creating database", start);
 
 			db.transaction(false, txn -> {
+				long start1 = now();
+				db.removeTemporaryMessages(txn);
+				logDuration(LOG, "Removing temporary messages", start1);
 				for (OpenDatabaseHook hook : openDatabaseHooks) {
-					long start1 = now();
+					start1 = now();
 					hook.onDatabaseOpened(txn);
 					if (LOG.isLoggable(FINE)) {
 						logDuration(LOG, "Calling open database hook "

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

@@ -195,8 +195,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (!assetsAreUpToDate()) installAssets();
 		if (cookieFile.exists() && !cookieFile.delete())
 			LOG.warning("Old auth cookie not deleted");
-		// Migrate old settings before having a chance to stop
-		migrateSettings();
 		// Start a new Tor process
 		LOG.info("Starting Tor");
 		String torPath = torFile.getAbsolutePath();
@@ -816,21 +814,6 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		controlConnection.setConf("ConnectionPadding", enable ? "1" : "0");
 	}
 
-	// TODO remove when sufficient time has passed. Added 2018-08-15
-	private void migrateSettings() {
-		Settings sOld = callback.getSettings();
-		int oldNetwork = sOld.getInt("network", -1);
-		if (oldNetwork == -1) return;
-		Settings s = new Settings();
-		if (oldNetwork == 0) {
-			s.putInt(PREF_TOR_NETWORK, PREF_TOR_NETWORK_NEVER);
-		} else if (oldNetwork == 1) {
-			s.putBoolean(PREF_TOR_MOBILE, false);
-		}
-		s.putInt("network", -1);
-		callback.mergeSettings(s);
-	}
-
 	private static class ConnectionStatus {
 
 		// All of the following are locking: this

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

@@ -284,7 +284,7 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 			meta.put("transportId", t.getString());
 			meta.put("version", version);
 			meta.put("local", local);
-			clientHelper.addLocalMessage(txn, m, meta, shared);
+			clientHelper.addLocalMessage(txn, m, meta, shared, false);
 		} catch (FormatException e) {
 			throw new RuntimeException(e);
 		}

bramble-core/src/main/java/org/briarproject/bramble/rendezvous/RendezvousPollerImpl.java

@@ -66,6 +66,7 @@ import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.contact.PendingContactState.ADDING_CONTACT;
 import static org.briarproject.bramble.api.contact.PendingContactState.FAILED;
+import static org.briarproject.bramble.api.contact.PendingContactState.OFFLINE;
 import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNull;
 import static org.briarproject.bramble.rendezvous.RendezvousConstants.POLLING_INTERVAL_MS;
@@ -158,9 +159,7 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 	private void addPendingContact(PendingContact p) {
 		long now = clock.currentTimeMillis();
 		long expiry = p.getTimestamp() + RENDEZVOUS_TIMEOUT_MS;
-		if (expiry > now) {
-			broadcastState(p.getId(), WAITING_FOR_CONNECTION);
-		} else {
+		if (expiry <= now) {
 			broadcastState(p.getId(), FAILED);
 			return;
 		}
@@ -180,9 +179,13 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 			for (PluginState ps : pluginStates.values()) {
 				RendezvousEndpoint endpoint =
 						createEndpoint(ps.plugin, p.getId(), cs);
-				if (endpoint != null)
+				if (endpoint != null) {
 					requireNull(ps.endpoints.put(p.getId(), endpoint));
+					cs.numEndpoints++;
+				}
 			}
+			if (cs.numEndpoints == 0) broadcastState(p.getId(), OFFLINE);
+			else broadcastState(p.getId(), WAITING_FOR_CONNECTION);
 		} catch (DbException | GeneralSecurityException e) {
 			logException(LOG, WARNING, e);
 		}
@@ -328,9 +331,14 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 		TransportId t = plugin.getId();
 		Map<PendingContactId, RendezvousEndpoint> endpoints = new HashMap<>();
 		for (Entry<PendingContactId, CryptoState> e : cryptoStates.entrySet()) {
-			RendezvousEndpoint endpoint =
-					createEndpoint(plugin, e.getKey(), e.getValue());
-			if (endpoint != null) endpoints.put(e.getKey(), endpoint);
+			PendingContactId p = e.getKey();
+			CryptoState cs = e.getValue();
+			RendezvousEndpoint endpoint = createEndpoint(plugin, p, cs);
+			if (endpoint != null) {
+				endpoints.put(p, endpoint);
+				if (++cs.numEndpoints == 1)
+					broadcastState(p, WAITING_FOR_CONNECTION);
+			}
 		}
 		requireNull(pluginStates.put(t, new PluginState(plugin, endpoints)));
 	}
@@ -344,8 +352,11 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 	private void removeTransport(TransportId t) {
 		PluginState ps = pluginStates.remove(t);
 		if (ps != null) {
-			for (RendezvousEndpoint endpoint : ps.endpoints.values()) {
-				tryToClose(endpoint, LOG, INFO);
+			for (Entry<PendingContactId, RendezvousEndpoint> e :
+					ps.endpoints.entrySet()) {
+				tryToClose(e.getValue(), LOG, INFO);
+				CryptoState cs = cryptoStates.get(e.getKey());
+				if (--cs.numEndpoints == 0) broadcastState(e.getKey(), OFFLINE);
 			}
 		}
 	}
@@ -391,6 +402,8 @@ class RendezvousPollerImpl implements RendezvousPoller, Service, EventListener {
 		private final boolean alice;
 		private final long expiry;
 
+		private int numEndpoints = 0;
+
 		private CryptoState(SecretKey rendezvousKey, boolean alice,
 				long expiry) {
 			this.rendezvousKey = rendezvousKey;

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

@@ -17,6 +17,7 @@ import org.briarproject.bramble.api.sync.Offer;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
 import org.briarproject.bramble.api.sync.SyncSession;
+import org.briarproject.bramble.api.sync.Versions;
 import org.briarproject.bramble.api.sync.event.GroupVisibilityUpdatedEvent;
 import org.briarproject.bramble.api.sync.event.MessageRequestedEvent;
 import org.briarproject.bramble.api.sync.event.MessageSharedEvent;
@@ -39,9 +40,11 @@ import javax.annotation.concurrent.ThreadSafe;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
 import static org.briarproject.bramble.api.record.Record.MAX_RECORD_PAYLOAD_BYTES;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
+import static org.briarproject.bramble.api.sync.SyncConstants.SUPPORTED_VERSIONS;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 /**
@@ -55,7 +58,7 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 class DuplexOutgoingSession implements SyncSession, EventListener {
 
 	private static final Logger LOG =
-			Logger.getLogger(DuplexOutgoingSession.class.getName());
+			getLogger(DuplexOutgoingSession.class.getName());
 
 	private static final ThrowingRunnable<IOException> CLOSE = () -> {
 	};
@@ -103,6 +106,8 @@ class DuplexOutgoingSession implements SyncSession, EventListener {
 	public void run() throws IOException {
 		eventBus.addListener(this);
 		try {
+			// Send our supported protocol versions
+			recordWriter.writeVersions(new Versions(SUPPORTED_VERSIONS));
 			// Start a query for each type of record
 			generateAck();
 			generateBatch();

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

@@ -18,14 +18,17 @@ import org.briarproject.bramble.api.sync.Offer;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
 import org.briarproject.bramble.api.sync.SyncSession;
+import org.briarproject.bramble.api.sync.Versions;
 
 import java.io.IOException;
+import java.util.List;
 import java.util.concurrent.Executor;
 import java.util.logging.Logger;
 
 import javax.annotation.concurrent.ThreadSafe;
 
 import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
@@ -37,7 +40,7 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 class IncomingSession implements SyncSession, EventListener {
 
 	private static final Logger LOG =
-			Logger.getLogger(IncomingSession.class.getName());
+			getLogger(IncomingSession.class.getName());
 
 	private final DatabaseComponent db;
 	private final Executor dbExecutor;
@@ -80,6 +83,9 @@ class IncomingSession implements SyncSession, EventListener {
 				} else if (recordReader.hasRequest()) {
 					Request r = recordReader.readRequest();
 					dbExecutor.execute(new ReceiveRequest(r));
+				} else if (recordReader.hasVersions()) {
+					Versions v = recordReader.readVersions();
+					dbExecutor.execute(new ReceiveVersions(v));
 				} else {
 					// unknown records are ignored in RecordReader#eof()
 					throw new FormatException();
@@ -190,4 +196,26 @@ class IncomingSession implements SyncSession, EventListener {
 			}
 		}
 	}
+
+	private class ReceiveVersions implements Runnable {
+
+		private final Versions versions;
+
+		private ReceiveVersions(Versions versions) {
+			this.versions = versions;
+		}
+
+		@DatabaseExecutor
+		@Override
+		public void run() {
+			try {
+				List<Byte> supported = versions.getSupportedVersions();
+				db.transaction(false,
+						txn -> db.setSyncVersions(txn, contactId, supported));
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				interrupt();
+			}
+		}
+	}
 }

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

@@ -15,6 +15,7 @@ import org.briarproject.bramble.api.sync.Ack;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
 import org.briarproject.bramble.api.sync.SyncSession;
+import org.briarproject.bramble.api.sync.Versions;
 import org.briarproject.bramble.api.transport.StreamWriter;
 
 import java.io.IOException;
@@ -29,9 +30,11 @@ import javax.annotation.concurrent.ThreadSafe;
 
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
+import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.lifecycle.LifecycleManager.LifecycleState.STOPPING;
 import static org.briarproject.bramble.api.record.Record.MAX_RECORD_PAYLOAD_BYTES;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
+import static org.briarproject.bramble.api.sync.SyncConstants.SUPPORTED_VERSIONS;
 import static org.briarproject.bramble.util.LogUtils.logException;
 
 /**
@@ -44,7 +47,7 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 class SimplexOutgoingSession implements SyncSession, EventListener {
 
 	private static final Logger LOG =
-			Logger.getLogger(SimplexOutgoingSession.class.getName());
+			getLogger(SimplexOutgoingSession.class.getName());
 
 	private static final ThrowingRunnable<IOException> CLOSE = () -> {
 	};
@@ -80,6 +83,8 @@ class SimplexOutgoingSession implements SyncSession, EventListener {
 	public void run() throws IOException {
 		eventBus.addListener(this);
 		try {
+			// Send our supported protocol versions
+			recordWriter.writeVersions(new Versions(SUPPORTED_VERSIONS));
 			// Start a query for each type of record
 			dbExecutor.execute(new GenerateAck());
 			dbExecutor.execute(new GenerateBatch());

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

@@ -13,6 +13,7 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.Offer;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
+import org.briarproject.bramble.api.sync.Versions;
 import org.briarproject.bramble.util.ByteUtils;
 
 import java.io.IOException;
@@ -26,6 +27,8 @@ import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
 import static org.briarproject.bramble.api.sync.RecordTypes.MESSAGE;
 import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
 import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
+import static org.briarproject.bramble.api.sync.RecordTypes.VERSIONS;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_SUPPORTED_VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
 
@@ -45,7 +48,7 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 
 	private static boolean isKnownRecordType(byte type) {
 		return type == ACK || type == MESSAGE || type == OFFER ||
-				type == REQUEST;
+				type == REQUEST || type == VERSIONS;
 	}
 
 	private final MessageFactory messageFactory;
@@ -148,4 +151,27 @@ class SyncRecordReaderImpl implements SyncRecordReader {
 		if (!hasRequest()) throw new FormatException();
 		return new Request(readMessageIds());
 	}
+
+	@Override
+	public boolean hasVersions() throws IOException {
+		return !eof() && getNextRecordType() == VERSIONS;
+	}
+
+	@Override
+	public Versions readVersions() throws IOException {
+		if (!hasVersions()) throw new FormatException();
+		return new Versions(readSupportedVersions());
+	}
+
+	private List<Byte> readSupportedVersions() throws IOException {
+		if (nextRecord == null) throw new AssertionError();
+		byte[] payload = nextRecord.getPayload();
+		if (payload.length == 0) throw new FormatException();
+		if (payload.length > MAX_SUPPORTED_VERSIONS)
+			throw new FormatException();
+		List<Byte> supported = new ArrayList<>(payload.length);
+		for (byte b : payload) supported.add(b);
+		nextRecord = null;
+		return supported;
+	}
 }

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

@@ -10,6 +10,7 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.Offer;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
+import org.briarproject.bramble.api.sync.Versions;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -20,6 +21,7 @@ import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
 import static org.briarproject.bramble.api.sync.RecordTypes.MESSAGE;
 import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
 import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
+import static org.briarproject.bramble.api.sync.RecordTypes.VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
 
 @NotThreadSafe
@@ -65,6 +67,12 @@ class SyncRecordWriterImpl implements SyncRecordWriter {
 		writeRecord(REQUEST);
 	}
 
+	@Override
+	public void writeVersions(Versions v) throws IOException {
+		for (byte b : v.getSupportedVersions()) payload.write(b);
+		writeRecord(VERSIONS);
+	}
+
 	@Override
 	public void flush() throws IOException {
 		writer.flush();

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

@@ -314,6 +314,7 @@ class ValidationManagerImpl implements ValidationManager, Service,
 			try {
 				shareMsg = hook.incomingMessage(txn, m, meta);
 			} catch (InvalidMessageException e) {
+				logException(LOG, INFO, e);
 				invalidateMessage(txn, m.getId());
 				return new DeliveryResult(false, false);
 			}

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

@@ -26,7 +26,9 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.validation.IncomingMessageHook;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientMajorVersion;
+import org.briarproject.bramble.api.versioning.ClientVersion;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
+import org.briarproject.bramble.api.versioning.event.ClientVersionUpdatedEvent;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -80,9 +82,9 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	@Override
 	public void registerClient(ClientId clientId, int majorVersion,
 			int minorVersion, ClientVersioningHook hook) {
-		ClientMajorVersion cv = new ClientMajorVersion(clientId, majorVersion);
-		clients.add(new ClientVersion(cv, minorVersion));
-		hooks.put(cv, hook);
+		ClientMajorVersion cmv = new ClientMajorVersion(clientId, majorVersion);
+		clients.add(new ClientVersion(cmv, minorVersion));
+		hooks.put(cmv, hook);
 	}
 
 	@Override
@@ -96,9 +98,9 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			Update remoteUpdate = loadUpdate(txn, latest.remote.messageId);
 			Map<ClientMajorVersion, Visibility> visibilities =
 					getVisibilities(localUpdate.states, remoteUpdate.states);
-			ClientMajorVersion cv =
+			ClientMajorVersion key =
 					new ClientMajorVersion(clientId, majorVersion);
-			Visibility v = visibilities.get(cv);
+			Visibility v = visibilities.get(key);
 			return v == null ? INVISIBLE : v;
 		} catch (FormatException e) {
 			throw new DbException(e);
@@ -112,10 +114,11 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			LatestUpdates latest = findLatestUpdates(txn, contactId);
 			if (latest == null || latest.remote == null) return -1;
 			Update remoteUpdate = loadUpdate(txn, latest.remote.messageId);
-			ClientMajorVersion cv =
+			ClientMajorVersion key =
 					new ClientMajorVersion(clientId, majorVersion);
 			for (ClientState remote : remoteUpdate.states) {
-				if (remote.majorVersion.equals(cv)) return remote.minorVersion;
+				if (remote.clientVersion.getClientMajorVersion().equals(key))
+					return remote.clientVersion.getMinorVersion();
 			}
 			return -1;
 		} catch (FormatException e) {
@@ -226,9 +229,21 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			Map<ClientMajorVersion, Visibility> after =
 					getVisibilities(newLocalStates, newRemoteStates);
 			// Call hooks for any visibilities that have changed
+			ContactId c = getContactId(txn, m.getGroupId());
 			if (!before.equals(after)) {
-				Contact c = getContact(txn, m.getGroupId());
-				callVisibilityHooks(txn, c, before, after);
+				Contact contact = db.getContact(txn, c);
+				callVisibilityHooks(txn, contact, before, after);
+			}
+			// Broadcast events for any new client versions
+			Set<ClientVersion> oldRemoteVersions = new HashSet<>();
+			for (ClientState cs : oldRemoteStates) {
+				oldRemoteVersions.add(cs.clientVersion);
+			}
+			for (ClientState cs : newRemoteStates) {
+				if (!oldRemoteVersions.contains(cs.clientVersion)) {
+					txn.attach(new ClientVersionUpdatedEvent(c,
+							cs.clientVersion));
+				}
 			}
 		} catch (FormatException e) {
 			throw new InvalidMessageException(e);
@@ -243,7 +258,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		try {
 			Message m = clientHelper.createMessage(localGroup.getId(), now,
 					body);
-			db.addLocalMessage(txn, m, new Metadata(), false);
+			db.addLocalMessage(txn, m, new Metadata(), false, false);
 		} catch (FormatException e) {
 			throw new AssertionError(e);
 		}
@@ -256,8 +271,8 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	}
 
 	private BdfList encodeClientVersion(ClientVersion cv) {
-		return BdfList.of(cv.majorVersion.getClientId().getString(),
-				cv.majorVersion.getMajorVersion(), cv.minorVersion);
+		return BdfList.of(cv.getClientId().getString(), cv.getMajorVersion(),
+				cv.getMinorVersion());
 	}
 
 	/**
@@ -298,8 +313,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			ClientId clientId = new ClientId(cv.getString(0));
 			int majorVersion = cv.getLong(1).intValue();
 			int minorVersion = cv.getLong(2).intValue();
-			parsed.add(new ClientVersion(clientId, majorVersion,
-					minorVersion));
+			parsed.add(new ClientVersion(clientId, majorVersion, minorVersion));
 		}
 		return parsed;
 	}
@@ -418,13 +432,15 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	private List<ClientState> updateStatesFromLocalVersions(
 			List<ClientState> oldStates, List<ClientVersion> newVersions) {
 		Map<ClientMajorVersion, ClientState> oldMap = new HashMap<>();
-		for (ClientState cs : oldStates) oldMap.put(cs.majorVersion, cs);
+		for (ClientState cs : oldStates) {
+			oldMap.put(cs.clientVersion.getClientMajorVersion(), cs);
+		}
 		List<ClientState> newStates = new ArrayList<>(newVersions.size());
 		for (ClientVersion newVersion : newVersions) {
-			ClientState oldState = oldMap.get(newVersion.majorVersion);
+			ClientMajorVersion key = newVersion.getClientMajorVersion();
+			ClientState oldState = oldMap.get(key);
 			boolean active = oldState != null && oldState.active;
-			newStates.add(new ClientState(newVersion.majorVersion,
-					newVersion.minorVersion, active));
+			newStates.add(new ClientState(newVersion, active));
 		}
 		return newStates;
 	}
@@ -438,7 +454,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			BdfDictionary meta = new BdfDictionary();
 			meta.put(MSG_KEY_UPDATE_VERSION, updateVersion);
 			meta.put(MSG_KEY_LOCAL, true);
-			clientHelper.addLocalMessage(txn, m, meta, true);
+			clientHelper.addLocalMessage(txn, m, meta, true, false);
 		} catch (FormatException e) {
 			throw new RuntimeException(e);
 		}
@@ -451,21 +467,25 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	}
 
 	private BdfList encodeClientState(ClientState cs) {
-		return BdfList.of(cs.majorVersion.getClientId().getString(),
-				cs.majorVersion.getMajorVersion(), cs.minorVersion, cs.active);
+		ClientVersion cv = cs.clientVersion;
+		return BdfList.of(cv.getClientId().getString(), cv.getMajorVersion(),
+				cv.getMinorVersion(), cs.active);
 	}
 
 	private Map<ClientMajorVersion, Visibility> getVisibilities(
 			List<ClientState> localStates, List<ClientState> remoteStates) {
 		Map<ClientMajorVersion, ClientState> remoteMap = new HashMap<>();
-		for (ClientState cs : remoteStates) remoteMap.put(cs.majorVersion, cs);
+		for (ClientState cs : remoteStates) {
+			remoteMap.put(cs.clientVersion.getClientMajorVersion(), cs);
+		}
 		Map<ClientMajorVersion, Visibility> visibilities = new HashMap<>();
 		for (ClientState local : localStates) {
-			ClientState remote = remoteMap.get(local.majorVersion);
-			if (remote == null) visibilities.put(local.majorVersion, INVISIBLE);
-			else if (remote.active)
-				visibilities.put(local.majorVersion, SHARED);
-			else visibilities.put(local.majorVersion, VISIBLE);
+			ClientMajorVersion key =
+					local.clientVersion.getClientMajorVersion();
+			ClientState remote = remoteMap.get(key);
+			if (remote == null) visibilities.put(key, INVISIBLE);
+			else if (remote.active) visibilities.put(key, SHARED);
+			else visibilities.put(key, VISIBLE);
 		}
 		return visibilities;
 	}
@@ -486,9 +506,9 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		}
 	}
 
-	private void callVisibilityHook(Transaction txn, ClientMajorVersion cv,
+	private void callVisibilityHook(Transaction txn, ClientMajorVersion cmv,
 			Contact c, Visibility v) throws DbException {
-		ClientVersioningHook hook = hooks.get(cv);
+		ClientVersioningHook hook = hooks.get(cmv);
 		if (hook != null) hook.onClientVisibilityChanging(txn, c, v);
 	}
 
@@ -496,18 +516,17 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			List<ClientVersion> versions) throws DbException {
 		List<ClientState> states = new ArrayList<>(versions.size());
 		for (ClientVersion cv : versions) {
-			states.add(new ClientState(cv.majorVersion, cv.minorVersion,
-					false));
+			states.add(new ClientState(cv, false));
 		}
 		storeUpdate(txn, g, states, 1);
 	}
 
-	private Contact getContact(Transaction txn, GroupId g) throws DbException {
+	private ContactId getContactId(Transaction txn, GroupId g)
+			throws DbException {
 		try {
 			BdfDictionary meta =
 					clientHelper.getGroupMetadataAsDictionary(txn, g);
-			int id = meta.getLong(GROUP_KEY_CONTACT_ID).intValue();
-			return db.getContact(txn, new ContactId(id));
+			return new ContactId(meta.getLong(GROUP_KEY_CONTACT_ID).intValue());
 		} catch (FormatException e) {
 			throw new DbException(e);
 		}
@@ -516,13 +535,16 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 	private List<ClientState> updateStatesFromRemoteStates(
 			List<ClientState> oldLocalStates, List<ClientState> remoteStates) {
 		Set<ClientMajorVersion> remoteSet = new HashSet<>();
-		for (ClientState cs : remoteStates) remoteSet.add(cs.majorVersion);
+		for (ClientState cs : remoteStates) {
+			remoteSet.add(cs.clientVersion.getClientMajorVersion());
+		}
 		List<ClientState> newLocalStates =
 				new ArrayList<>(oldLocalStates.size());
 		for (ClientState oldState : oldLocalStates) {
-			boolean active = remoteSet.contains(oldState.majorVersion);
-			newLocalStates.add(new ClientState(oldState.majorVersion,
-					oldState.minorVersion, active));
+			ClientMajorVersion cmv =
+					oldState.clientVersion.getClientMajorVersion();
+			boolean active = remoteSet.contains(cmv);
+			newLocalStates.add(new ClientState(oldState.clientVersion, active));
 		}
 		return newLocalStates;
 	}
@@ -561,61 +583,19 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		}
 	}
 
-	private static class ClientVersion implements Comparable<ClientVersion> {
-
-		private final ClientMajorVersion majorVersion;
-		private final int minorVersion;
-
-		private ClientVersion(ClientMajorVersion majorVersion,
-				int minorVersion) {
-			this.majorVersion = majorVersion;
-			this.minorVersion = minorVersion;
-		}
-
-		private ClientVersion(ClientId clientId, int majorVersion,
-				int minorVersion) {
-			this(new ClientMajorVersion(clientId, majorVersion), minorVersion);
-		}
-
-		@Override
-		public boolean equals(Object o) {
-			if (o instanceof ClientVersion) {
-				ClientVersion cv = (ClientVersion) o;
-				return majorVersion.equals(cv.majorVersion)
-						&& minorVersion == cv.minorVersion;
-			}
-			return false;
-		}
-
-		@Override
-		public int hashCode() {
-			return majorVersion.hashCode();
-		}
-
-		@Override
-		public int compareTo(ClientVersion cv) {
-			int compare = majorVersion.compareTo(cv.majorVersion);
-			if (compare != 0) return compare;
-			return minorVersion - cv.minorVersion;
-		}
-	}
-
 	private static class ClientState {
 
-		private final ClientMajorVersion majorVersion;
-		private final int minorVersion;
+		private final ClientVersion clientVersion;
 		private final boolean active;
 
-		private ClientState(ClientMajorVersion majorVersion, int minorVersion,
-				boolean active) {
-			this.majorVersion = majorVersion;
-			this.minorVersion = minorVersion;
+		private ClientState(ClientVersion clientVersion, boolean active) {
+			this.clientVersion = clientVersion;
 			this.active = active;
 		}
 
 		private ClientState(ClientId clientId, int majorVersion,
 				int minorVersion, boolean active) {
-			this(new ClientMajorVersion(clientId, majorVersion), minorVersion,
+			this(new ClientVersion(clientId, majorVersion, minorVersion),
 					active);
 		}
 
@@ -623,8 +603,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		public boolean equals(Object o) {
 			if (o instanceof ClientState) {
 				ClientState cs = (ClientState) o;
-				return majorVersion.equals(cs.majorVersion)
-						&& minorVersion == cs.minorVersion
+				return clientVersion.equals(cs.clientVersion)
 						&& active == cs.active;
 			}
 			return false;
@@ -632,7 +611,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 
 		@Override
 		public int hashCode() {
-			return majorVersion.hashCode();
+			return clientVersion.hashCode();
 		}
 	}
 }

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

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.account;
 
 import org.briarproject.bramble.api.crypto.CryptoComponent;
+import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.identity.Identity;
@@ -39,6 +40,8 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 
 	private final DatabaseConfig databaseConfig =
 			context.mock(DatabaseConfig.class);
+	private final KeyStrengthener keyStrengthener =
+			context.mock(KeyStrengthener.class);
 	private final CryptoComponent crypto = context.mock(CryptoComponent.class);
 	private final IdentityManager identityManager =
 			context.mock(IdentityManager.class);
@@ -68,6 +71,8 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(dbDir));
 			allowing(databaseConfig).getDatabaseKeyDirectory();
 			will(returnValue(keyDir));
+			allowing(databaseConfig).getKeyStrengthener();
+			will(returnValue(keyStrengthener));
 		}});
 
 		accountManager =
@@ -89,7 +94,8 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testSignInReturnsFalseIfPasswordIsWrong() throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(crypto).decryptWithPassword(encryptedKey, password);
+			oneOf(crypto).decryptWithPassword(encryptedKey, password,
+					keyStrengthener);
 			will(returnValue(null));
 		}});
 
@@ -109,8 +115,11 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testSignInReturnsTrueIfPasswordIsRight() throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(crypto).decryptWithPassword(encryptedKey, password);
+			oneOf(crypto).decryptWithPassword(encryptedKey, password,
+					keyStrengthener);
 			will(returnValue(key.getBytes()));
+			oneOf(crypto).isEncryptedWithStrengthenedKey(encryptedKey);
+			will(returnValue(true));
 		}});
 
 		storeDatabaseKey(keyFile, encryptedKeyHex);
@@ -129,6 +138,35 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
 	}
 
+	@Test
+	public void testSignInReEncryptsKey() throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(crypto).decryptWithPassword(encryptedKey, password,
+					keyStrengthener);
+			will(returnValue(key.getBytes()));
+			oneOf(crypto).isEncryptedWithStrengthenedKey(encryptedKey);
+			will(returnValue(false));
+			oneOf(crypto).encryptWithPassword(key.getBytes(), password,
+					keyStrengthener);
+			will(returnValue(newEncryptedKey));
+		}});
+
+		storeDatabaseKey(keyFile, encryptedKeyHex);
+		storeDatabaseKey(keyBackupFile, encryptedKeyHex);
+
+		assertEquals(encryptedKeyHex, loadDatabaseKey(keyFile));
+		assertEquals(encryptedKeyHex, loadDatabaseKey(keyBackupFile));
+
+		assertTrue(accountManager.signIn(password));
+		assertTrue(accountManager.hasDatabaseKey());
+		SecretKey decrypted = accountManager.getDatabaseKey();
+		assertNotNull(decrypted);
+		assertArrayEquals(key.getBytes(), decrypted.getBytes());
+
+		assertEquals(newEncryptedKeyHex, loadDatabaseKey(keyFile));
+		assertEquals(newEncryptedKeyHex, loadDatabaseKey(keyBackupFile));
+	}
+
 	@Test
 	public void testDbKeyIsLoadedFromPrimaryFile() throws Exception {
 		storeDatabaseKey(keyFile, encryptedKeyHex);
@@ -258,7 +296,8 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 			oneOf(identityManager).registerIdentity(identity);
 			oneOf(crypto).generateSecretKey();
 			will(returnValue(key));
-			oneOf(crypto).encryptWithPassword(key.getBytes(), password);
+			oneOf(crypto).encryptWithPassword(key.getBytes(), password,
+					keyStrengthener);
 			will(returnValue(encryptedKey));
 		}});
 
@@ -287,7 +326,8 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	public void testChangePasswordReturnsFalseIfPasswordIsWrong()
 			throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(crypto).decryptWithPassword(encryptedKey, password);
+			oneOf(crypto).decryptWithPassword(encryptedKey, password,
+					keyStrengthener);
 			will(returnValue(null));
 		}});
 
@@ -304,9 +344,13 @@ public class AccountManagerImplTest extends BrambleMockTestCase {
 	public void testChangePasswordReturnsTrueIfPasswordIsRight()
 			throws Exception {
 		context.checking(new Expectations() {{
-			oneOf(crypto).decryptWithPassword(encryptedKey, password);
+			oneOf(crypto).decryptWithPassword(encryptedKey, password,
+					keyStrengthener);
 			will(returnValue(key.getBytes()));
-			oneOf(crypto).encryptWithPassword(key.getBytes(), newPassword);
+			oneOf(crypto).isEncryptedWithStrengthenedKey(encryptedKey);
+			will(returnValue(true));
+			oneOf(crypto).encryptWithPassword(key.getBytes(), newPassword,
+					keyStrengthener);
 			will(returnValue(newEncryptedKey));
 		}});
 

bramble-core/src/test/java/org/briarproject/bramble/client/ClientHelperImplTest.java

@@ -96,7 +96,7 @@ public class ClientHelperImplTest extends BrambleTestCase {
 			oneOf(db).transaction(with(false), withDbRunnable(txn));
 			oneOf(metadataEncoder).encode(dictionary);
 			will(returnValue(metadata));
-			oneOf(db).addLocalMessage(txn, message, metadata, shared);
+			oneOf(db).addLocalMessage(txn, message, metadata, shared, false);
 		}});
 
 		clientHelper.addLocalMessage(message, dictionary, shared);

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

@@ -1,16 +1,21 @@
 package org.briarproject.bramble.contact;
 
+import org.briarproject.bramble.BrambleCoreEagerSingletons;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.contact.event.ContactAddedEvent;
+import org.briarproject.bramble.api.contact.event.PendingContactStateChangedEvent;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.Identity;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestDatabaseConfigModule;
 import org.briarproject.bramble.test.TestDuplexTransportConnection;
@@ -27,7 +32,7 @@ import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static junit.framework.TestCase.assertNotNull;
 import static junit.framework.TestCase.assertNull;
 import static junit.framework.TestCase.fail;
-import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
+import static org.briarproject.bramble.api.contact.PendingContactState.OFFLINE;
 import static org.briarproject.bramble.test.TestDuplexTransportConnection.createPair;
 import static org.briarproject.bramble.test.TestPluginConfigModule.DUPLEX_TRANSPORT_ID;
 import static org.briarproject.bramble.test.TestUtils.deleteTestDirectory;
@@ -57,11 +62,11 @@ public class ContactExchangeIntegrationTest extends BrambleTestCase {
 		alice = DaggerContactExchangeIntegrationTestComponent.builder()
 				.testDatabaseConfigModule(
 						new TestDatabaseConfigModule(aliceDir)).build();
-		alice.injectBrambleCoreEagerSingletons();
+		BrambleCoreEagerSingletons.Helper.injectEagerSingletons(alice);
 		bob = DaggerContactExchangeIntegrationTestComponent.builder()
 				.testDatabaseConfigModule(new TestDatabaseConfigModule(bobDir))
 				.build();
-		bob.injectBrambleCoreEagerSingletons();
+		BrambleCoreEagerSingletons.Helper.injectEagerSingletons(bob);
 		// Set up the devices and get the identities
 		aliceIdentity = setUp(alice, "Alice");
 		bobIdentity = setUp(bob, "Bob");
@@ -188,9 +193,14 @@ public class ContactExchangeIntegrationTest extends BrambleTestCase {
 	private PendingContact addPendingContact(
 			ContactExchangeIntegrationTestComponent local,
 			ContactExchangeIntegrationTestComponent remote) throws Exception {
+		EventWaiter waiter = new EventWaiter();
+		local.getEventBus().addListener(waiter);
 		String link = remote.getContactManager().getHandshakeLink();
 		String alias = remote.getIdentityManager().getLocalAuthor().getName();
-		return local.getContactManager().addPendingContact(link, alias);
+		PendingContact pendingContact =
+				local.getContactManager().addPendingContact(link, alias);
+		waiter.latch.await(TIMEOUT, MILLISECONDS);
+		return pendingContact;
 	}
 
 	private void assertContacts(boolean verified,
@@ -237,7 +247,7 @@ public class ContactExchangeIntegrationTest extends BrambleTestCase {
 		assertEquals(1, pairs.size());
 		Pair<PendingContact, PendingContactState> pair =
 				pairs.iterator().next();
-		assertEquals(WAITING_FOR_CONNECTION, pair.getSecond());
+		assertEquals(OFFLINE, pair.getSecond());
 		PendingContact pendingContact = pair.getFirst();
 		assertEquals(expectedIdentity.getLocalAuthor().getName(),
 				pendingContact.getAlias());
@@ -261,4 +271,19 @@ public class ContactExchangeIntegrationTest extends BrambleTestCase {
 		tearDown(bob);
 		deleteTestDirectory(testDir);
 	}
+
+	@NotNullByDefault
+	private static class EventWaiter implements EventListener {
+
+		private final CountDownLatch latch = new CountDownLatch(1);
+
+		@Override
+		public void eventOccurred(Event e) {
+			if (e instanceof PendingContactStateChangedEvent) {
+				PendingContactStateChangedEvent p =
+						(PendingContactStateChangedEvent) e;
+				if (p.getPendingContactState() == OFFLINE) latch.countDown();
+			}
+		}
+	}
 }

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

@@ -21,8 +21,8 @@ public class PasswordBasedEncryptionTest extends BrambleTestCase {
 	public void testEncryptionAndDecryption() {
 		byte[] input = TestUtils.getRandomBytes(1234);
 		String password = "password";
-		byte[] ciphertext = crypto.encryptWithPassword(input, password);
-		byte[] output = crypto.decryptWithPassword(ciphertext, password);
+		byte[] ciphertext = crypto.encryptWithPassword(input, password, null);
+		byte[] output = crypto.decryptWithPassword(ciphertext, password, null);
 		assertArrayEquals(input, output);
 	}
 
@@ -30,11 +30,11 @@ public class PasswordBasedEncryptionTest extends BrambleTestCase {
 	public void testInvalidCiphertextReturnsNull() {
 		byte[] input = TestUtils.getRandomBytes(1234);
 		String password = "password";
-		byte[] ciphertext = crypto.encryptWithPassword(input, password);
+		byte[] ciphertext = crypto.encryptWithPassword(input, password, null);
 		// Modify the ciphertext
 		int position = new Random().nextInt(ciphertext.length);
 		ciphertext[position] = (byte) (ciphertext[position] ^ 0xFF);
-		byte[] output = crypto.decryptWithPassword(ciphertext, password);
+		byte[] output = crypto.decryptWithPassword(ciphertext, password, null);
 		assertNull(output);
 	}
 }

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

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.Bytes;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.system.SystemClock;
+import org.briarproject.bramble.test.ArrayClock;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.junit.Test;
 
@@ -11,8 +12,6 @@ import java.util.HashSet;
 import java.util.Set;
 
 import static junit.framework.TestCase.assertTrue;
-
-import org.briarproject.bramble.test.ArrayClock;
 import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
 import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.junit.Assert.assertEquals;

bramble-core/src/test/java/org/briarproject/bramble/db/DatabaseComponentImplTest.java

@@ -61,10 +61,12 @@ import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Random;
 import java.util.concurrent.Executor;
 import java.util.concurrent.atomic.AtomicReference;
 
 import static java.util.Arrays.asList;
+import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
@@ -120,6 +122,9 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 	private final Contact contact;
 	private final KeySetId keySetId;
 	private final PendingContactId pendingContactId;
+	private final Random random = new Random();
+	private final boolean shared = random.nextBoolean();
+	private final boolean temporary = random.nextBoolean();
 
 	public DatabaseComponentImplTest() {
 		clientId = getClientId();
@@ -253,7 +258,8 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
-				db.addLocalMessage(transaction, message, metadata, true));
+				db.addLocalMessage(transaction, message, metadata, shared,
+						temporary));
 	}
 
 	@Test
@@ -265,20 +271,23 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			will(returnValue(true));
 			oneOf(database).containsMessage(txn, messageId);
 			will(returnValue(false));
-			oneOf(database).addMessage(txn, message, DELIVERED, true, null);
+			oneOf(database).addMessage(txn, message, DELIVERED, shared,
+					temporary, null);
 			oneOf(database).mergeMessageMetadata(txn, messageId, metadata);
 			oneOf(database).commitTransaction(txn);
 			// The message was added, so the listeners should be called
 			oneOf(eventBus).broadcast(with(any(MessageAddedEvent.class)));
-			oneOf(eventBus)
-					.broadcast(with(any(MessageStateChangedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(MessageSharedEvent.class)));
+			oneOf(eventBus).broadcast(with(any(
+					MessageStateChangedEvent.class)));
+			if (shared)
+				oneOf(eventBus).broadcast(with(any(MessageSharedEvent.class)));
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
 				eventExecutor, shutdownManager);
 
 		db.transaction(false, transaction ->
-				db.addLocalMessage(transaction, message, metadata, true));
+				db.addLocalMessage(transaction, message, metadata, shared,
+						temporary));
 	}
 
 	@Test
@@ -286,11 +295,11 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			throws Exception {
 		context.checking(new Expectations() {{
 			// Check whether the contact is in the DB (which it's not)
-			exactly(16).of(database).startTransaction();
+			exactly(18).of(database).startTransaction();
 			will(returnValue(txn));
-			exactly(16).of(database).containsContact(txn, contactId);
+			exactly(18).of(database).containsContact(txn, contactId);
 			will(returnValue(false));
-			exactly(16).of(database).abortTransaction(txn);
+			exactly(18).of(database).abortTransaction(txn);
 		}});
 		DatabaseComponent db = createDatabaseComponent(database, eventBus,
 				eventExecutor, shutdownManager);
@@ -368,6 +377,14 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			// Expected
 		}
 
+		try {
+			db.transaction(false, transaction ->
+					db.getSyncVersions(transaction, contactId));
+			fail();
+		} catch (NoSuchContactException expected) {
+			// Expected
+		}
+
 		try {
 			Ack a = new Ack(singletonList(messageId));
 			db.transaction(false, transaction ->
@@ -427,6 +444,14 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		} catch (NoSuchContactException expected) {
 			// Expected
 		}
+
+		try {
+			db.transaction(false, transaction ->
+					db.setSyncVersions(transaction, contactId, emptyList()));
+			fail();
+		} catch (NoSuchContactException expected) {
+			// Expected
+		}
 	}
 
 	@Test
@@ -569,11 +594,11 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			throws Exception {
 		context.checking(new Expectations() {{
 			// Check whether the message is in the DB (which it's not)
-			exactly(11).of(database).startTransaction();
+			exactly(12).of(database).startTransaction();
 			will(returnValue(txn));
-			exactly(11).of(database).containsMessage(txn, messageId);
+			exactly(12).of(database).containsMessage(txn, messageId);
 			will(returnValue(false));
-			exactly(11).of(database).abortTransaction(txn);
+			exactly(12).of(database).abortTransaction(txn);
 			// Allow other checks to pass
 			allowing(database).containsContact(txn, contactId);
 			will(returnValue(true));
@@ -637,6 +662,14 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			// Expected
 		}
 
+		try {
+			db.transaction(false, transaction ->
+					db.setMessagePermanent(transaction, message.getId()));
+			fail();
+		} catch (NoSuchMessageException expected) {
+			// Expected
+		}
+
 		try {
 			db.transaction(false, transaction ->
 					db.setMessageShared(transaction, message.getId()));
@@ -972,7 +1005,8 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			will(returnValue(VISIBLE));
 			oneOf(database).containsMessage(txn, messageId);
 			will(returnValue(false));
-			oneOf(database).addMessage(txn, message, UNKNOWN, false, contactId);
+			oneOf(database).addMessage(txn, message, UNKNOWN, false, false,
+					contactId);
 			// Second time
 			oneOf(database).containsContact(txn, contactId);
 			will(returnValue(true));
@@ -1507,6 +1541,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 	public void testMessageDependencies() throws Exception {
 		int shutdownHandle = 12345;
 		MessageId messageId2 = new MessageId(getRandomId());
+
 		context.checking(new Expectations() {{
 			// open()
 			oneOf(database).open(key, null);
@@ -1521,7 +1556,8 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			will(returnValue(true));
 			oneOf(database).containsMessage(txn, messageId);
 			will(returnValue(false));
-			oneOf(database).addMessage(txn, message, DELIVERED, true, null);
+			oneOf(database).addMessage(txn, message, DELIVERED, shared,
+					temporary, null);
 			oneOf(database).mergeMessageMetadata(txn, messageId, metadata);
 			// addMessageDependencies()
 			oneOf(database).containsMessage(txn, messageId);
@@ -1544,7 +1580,8 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(eventBus).broadcast(with(any(MessageAddedEvent.class)));
 			oneOf(eventBus).broadcast(with(any(
 					MessageStateChangedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(MessageSharedEvent.class)));
+			if (shared)
+				oneOf(eventBus).broadcast(with(any(MessageSharedEvent.class)));
 			// endTransaction()
 			oneOf(database).commitTransaction(txn);
 			// close()
@@ -1555,7 +1592,8 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 
 		assertFalse(db.open(key, null));
 		db.transaction(false, transaction -> {
-			db.addLocalMessage(transaction, message, metadata, true);
+			db.addLocalMessage(transaction, message, metadata, shared,
+					temporary);
 			Collection<MessageId> dependencies = new ArrayList<>(2);
 			dependencies.add(messageId1);
 			dependencies.add(messageId2);

bramble-core/src/test/java/org/briarproject/bramble/db/DatabasePerformanceTest.java

@@ -567,8 +567,9 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 					MessageState state =
 							MessageState.fromValue(random.nextInt(4));
 					boolean shared = random.nextBoolean();
+					boolean temporary = random.nextBoolean();
 					ContactId sender = random.nextBoolean() ? c : null;
-					db.addMessage(txn, m, state, shared, sender);
+					db.addMessage(txn, m, state, shared, temporary, sender);
 					if (random.nextBoolean())
 						db.raiseRequestedFlag(txn, c, m.getId());
 					Metadata mm = getMetadata(METADATA_KEYS_PER_MESSAGE);
@@ -597,7 +598,8 @@ public abstract class DatabasePerformanceTest extends BrambleTestCase {
 			for (int j = 0; j < MESSAGES_PER_GROUP; j++) {
 				Message m = getMessage(g.getId());
 				messages.add(m);
-				db.addMessage(txn, m, DELIVERED, false, null);
+				boolean temporary = random.nextBoolean();
+				db.addMessage(txn, m, DELIVERED, false, temporary, null);
 				Metadata mm = getMetadata(METADATA_KEYS_PER_MESSAGE);
 				messageMeta.get(g.getId()).add(mm);
 				db.mergeMessageMetadata(txn, m.getId(), mm);

bramble-core/src/test/java/org/briarproject/bramble/db/JdbcDatabaseTest.java

@@ -34,6 +34,7 @@ import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.SettableClock;
 import org.briarproject.bramble.test.TestDatabaseConfig;
 import org.briarproject.bramble.test.TestMessageFactory;
+import org.briarproject.bramble.test.TestUtils;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -41,7 +42,6 @@ import org.junit.Test;
 import java.io.File;
 import java.sql.Connection;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
@@ -51,6 +51,7 @@ import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
 
+import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
@@ -153,7 +154,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.addGroup(txn, group);
 		assertTrue(db.containsGroup(txn, groupId));
 		assertFalse(db.containsMessage(txn, messageId));
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 		assertTrue(db.containsMessage(txn, messageId));
 		db.commitTransaction(txn);
 		db.close();
@@ -191,7 +192,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and a message
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// Removing the group should remove the message
 		assertTrue(db.containsMessage(txn, messageId));
@@ -213,7 +214,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// The contact has not seen the message, so it should be sendable
 		Collection<MessageId> ids =
@@ -244,7 +245,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
-		db.addMessage(txn, message, UNKNOWN, true, null);
+		db.addMessage(txn, message, UNKNOWN, true, false, null);
 
 		// The message has not been validated, so it should not be sendable
 		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
@@ -288,7 +289,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertEquals(contactId,
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// The group is invisible, so the message should not be sendable
 		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
@@ -340,7 +341,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
-		db.addMessage(txn, message, DELIVERED, false, null);
+		db.addMessage(txn, message, DELIVERED, false, false, null);
 
 		// The message is not shared, so it should not be sendable
 		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
@@ -371,7 +372,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// The message is sendable, but too large to send
 		Collection<MessageId> ids =
@@ -402,15 +403,15 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		// Add some messages to ack
 		Message message1 = getMessage(groupId);
 		MessageId messageId1 = message1.getId();
-		db.addMessage(txn, message, DELIVERED, true, contactId);
-		db.addMessage(txn, message1, DELIVERED, true, contactId);
+		db.addMessage(txn, message, DELIVERED, true, false, contactId);
+		db.addMessage(txn, message1, DELIVERED, true, false, contactId);
 
 		// Both message IDs should be returned
 		Collection<MessageId> ids = db.getMessagesToAck(txn, contactId, 1234);
-		assertEquals(Arrays.asList(messageId, messageId1), ids);
+		assertEquals(asList(messageId, messageId1), ids);
 
 		// Remove both message IDs
-		db.lowerAckFlag(txn, contactId, Arrays.asList(messageId, messageId1));
+		db.lowerAckFlag(txn, contactId, asList(messageId, messageId1));
 
 		// Both message IDs should have been removed
 		assertEquals(emptyList(), db.getMessagesToAck(txn,
@@ -422,7 +423,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Both message IDs should be returned
 		ids = db.getMessagesToAck(txn, contactId, 1234);
-		assertEquals(Arrays.asList(messageId, messageId1), ids);
+		assertEquals(asList(messageId, messageId1), ids);
 
 		db.commitTransaction(txn);
 		db.close();
@@ -439,7 +440,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// Retrieve the message from the database and mark it as sent
 		Collection<MessageId> ids = db.getMessagesToSend(txn, contactId,
@@ -608,7 +609,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertEquals(contactId,
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// The group is not visible so the message should not be visible
 		assertFalse(db.containsVisibleMessage(txn, contactId, messageId));
@@ -1149,6 +1150,43 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.close();
 	}
 
+	@Test
+	public void testGetContactsByHandshakePublicKey() throws Exception {
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Add an identity for a local author - no contacts should be
+		// associated
+		db.addIdentity(txn, identity);
+		PublicKey handshakePublicKey = TestUtils.getSignaturePublicKey();
+		Contact contact =
+				db.getContact(txn, handshakePublicKey, localAuthor.getId());
+		assertNull(contact);
+
+		// Add a contact associated with the local author
+		assertEquals(contactId, db.addContact(txn, author, localAuthor.getId(),
+				handshakePublicKey, true));
+		contact = db.getContact(txn, handshakePublicKey, localAuthor.getId());
+		assertNotNull(contact);
+		assertEquals(contactId, contact.getId());
+		assertEquals(author, contact.getAuthor());
+		assertNull(contact.getAlias());
+		assertEquals(handshakePublicKey, contact.getHandshakePublicKey());
+		assertTrue(contact.isVerified());
+		assertEquals(author.getName(), contact.getAuthor().getName());
+		assertEquals(author.getPublicKey(), contact.getAuthor().getPublicKey());
+		assertEquals(author.getFormatVersion(),
+				contact.getAuthor().getFormatVersion());
+
+		// Ensure no contacts are returned after contact was deleted
+		db.removeContact(txn, contactId);
+		contact = db.getContact(txn, handshakePublicKey, localAuthor.getId());
+		assertNull(contact);
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
 	@Test
 	public void testOfferedMessages() throws Exception {
 		Database<Connection> db = open(false);
@@ -1223,7 +1261,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and a message
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// Attach some metadata to the message
 		Metadata metadata = new Metadata();
@@ -1294,7 +1332,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and a message
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// Attach some metadata to the message
 		Metadata metadata = new Metadata();
@@ -1355,8 +1393,8 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and two messages
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, DELIVERED, true, null);
-		db.addMessage(txn, message1, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
+		db.addMessage(txn, message1, DELIVERED, true, false, null);
 
 		// Attach some metadata to the messages
 		Metadata metadata = new Metadata();
@@ -1459,8 +1497,8 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and two messages
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, DELIVERED, true, null);
-		db.addMessage(txn, message1, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
+		db.addMessage(txn, message1, DELIVERED, true, false, null);
 
 		// Attach some metadata to the messages
 		Metadata metadata = new Metadata();
@@ -1536,9 +1574,9 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and some messages
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, PENDING, true, contactId);
-		db.addMessage(txn, message1, PENDING, true, contactId);
-		db.addMessage(txn, message2, INVALID, true, contactId);
+		db.addMessage(txn, message, PENDING, true, false, contactId);
+		db.addMessage(txn, message1, PENDING, true, false, contactId);
+		db.addMessage(txn, message2, INVALID, true, false, contactId);
 
 		// Add dependencies
 		db.addMessageDependency(txn, message, messageId1, PENDING);
@@ -1589,7 +1627,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertEquals(0, dependents.size());
 
 		// Add message 3
-		db.addMessage(txn, message3, UNKNOWN, false, contactId);
+		db.addMessage(txn, message3, UNKNOWN, false, false, contactId);
 
 		// Message 3 has message 1 as a dependent
 		dependents = db.getMessageDependents(txn, messageId3);
@@ -1601,7 +1639,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertEquals(0, dependents.size());
 
 		// Add message 4
-		db.addMessage(txn, message4, UNKNOWN, false, contactId);
+		db.addMessage(txn, message4, UNKNOWN, false, false, contactId);
 
 		// Message 4 has message 2 as a dependent
 		dependents = db.getMessageDependents(txn, messageId4);
@@ -1619,7 +1657,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and a message
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, PENDING, true, contactId);
+		db.addMessage(txn, message, PENDING, true, false, contactId);
 
 		// Add a second group
 		Group group1 = getGroup(clientId, 123);
@@ -1629,7 +1667,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		// Add a message to the second group
 		Message message1 = getMessage(groupId1);
 		MessageId messageId1 = message1.getId();
-		db.addMessage(txn, message1, DELIVERED, true, contactId);
+		db.addMessage(txn, message1, DELIVERED, true, false, contactId);
 
 		// Create an ID for a missing message
 		MessageId messageId2 = new MessageId(getRandomId());
@@ -1637,7 +1675,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		// Add another message to the first group
 		Message message3 = getMessage(groupId);
 		MessageId messageId3 = message3.getId();
-		db.addMessage(txn, message3, DELIVERED, true, contactId);
+		db.addMessage(txn, message3, DELIVERED, true, false, contactId);
 
 		// Add dependencies between the messages
 		db.addMessageDependency(txn, message, messageId1, PENDING);
@@ -1680,10 +1718,10 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and some messages with different states
 		db.addGroup(txn, group);
-		db.addMessage(txn, message1, UNKNOWN, true, contactId);
-		db.addMessage(txn, message2, INVALID, true, contactId);
-		db.addMessage(txn, message3, PENDING, true, contactId);
-		db.addMessage(txn, message4, DELIVERED, true, contactId);
+		db.addMessage(txn, message1, UNKNOWN, true, false, contactId);
+		db.addMessage(txn, message2, INVALID, true, false, contactId);
+		db.addMessage(txn, message3, PENDING, true, false, contactId);
+		db.addMessage(txn, message4, DELIVERED, true, false, contactId);
 
 		Collection<MessageId> result;
 
@@ -1713,10 +1751,10 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and some messages
 		db.addGroup(txn, group);
-		db.addMessage(txn, message1, DELIVERED, true, contactId);
-		db.addMessage(txn, message2, DELIVERED, false, contactId);
-		db.addMessage(txn, message3, DELIVERED, false, contactId);
-		db.addMessage(txn, message4, DELIVERED, true, contactId);
+		db.addMessage(txn, message1, DELIVERED, true, false, contactId);
+		db.addMessage(txn, message2, DELIVERED, false, false, contactId);
+		db.addMessage(txn, message3, DELIVERED, false, false, contactId);
+		db.addMessage(txn, message4, DELIVERED, true, false, contactId);
 
 		// Introduce dependencies between the messages
 		db.addMessageDependency(txn, message1, message2.getId(), DELIVERED);
@@ -1744,7 +1782,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// The message should not be sent or seen
 		MessageStatus status = db.getMessageStatus(txn, contactId, messageId);
@@ -1878,7 +1916,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// The message should be visible to the contact
 		assertTrue(db.containsVisibleMessage(txn, contactId, messageId));
@@ -1961,7 +1999,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// Add a group and a message
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, UNKNOWN, false, contactId);
+		db.addMessage(txn, message, UNKNOWN, false, false, contactId);
 
 		// Walk the message through the validation and delivery states
 		assertEquals(UNKNOWN, db.getMessageState(txn, messageId));
@@ -1988,7 +2026,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertEquals(contactId,
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
-		db.addMessage(txn, message, UNKNOWN, false, null);
+		db.addMessage(txn, message, UNKNOWN, false, false, null);
 
 		// There should be no messages to send
 		assertEquals(Long.MAX_VALUE, db.getNextSendTime(txn, contactId));
@@ -2073,7 +2111,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// Time: now
 		// Retrieve the message from the database
@@ -2118,7 +2156,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 				db.addContact(txn, author, localAuthor.getId(), null, true));
 		db.addGroup(txn, group);
 		db.addGroupVisibility(txn, contactId, groupId, true);
-		db.addMessage(txn, message, DELIVERED, true, null);
+		db.addMessage(txn, message, DELIVERED, true, false, null);
 
 		// Time: now
 		// Retrieve the message from the database
@@ -2257,6 +2295,58 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.close();
 	}
 
+	@Test
+	public void testTemporaryMessages() throws Exception {
+		Message message1 = getMessage(groupId);
+		MessageId messageId1 = message1.getId();
+
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Add a group and two temporary messages
+		db.addGroup(txn, group);
+		db.addMessage(txn, message, DELIVERED, false, true, null);
+		db.addMessage(txn, message1, DELIVERED, false, true, null);
+
+		// Mark one of the messages as permanent
+		db.setMessagePermanent(txn, messageId);
+
+		// Remove all temporary messages
+		db.removeTemporaryMessages(txn);
+
+		// The permanent message should not have been removed
+		assertTrue(db.containsMessage(txn, messageId));
+
+		// The temporary message should have been removed
+		assertFalse(db.containsMessage(txn, messageId1));
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
+	@Test
+	public void testSyncVersions() throws Exception {
+		Database<Connection> db = open(false);
+		Connection txn = db.startTransaction();
+
+		// Add a contact
+		db.addIdentity(txn, identity);
+		assertEquals(contactId,
+				db.addContact(txn, author, localAuthor.getId(), null, true));
+
+		// Only sync version 0 should be supported by default
+		List<Byte> defaultSupported = singletonList((byte) 0);
+		assertEquals(defaultSupported, db.getSyncVersions(txn, contactId));
+
+		// Set the supported versions and check that they're returned
+		List<Byte> supported = asList((byte) 0, (byte) 1);
+		db.setSyncVersions(txn, contactId, supported);
+		assertEquals(supported, db.getSyncVersions(txn, contactId));
+
+		db.commitTransaction(txn);
+		db.close();
+	}
+
 	private Database<Connection> open(boolean resume) throws Exception {
 		return open(resume, new TestMessageFactory(), new SystemClock());
 	}

bramble-core/src/test/java/org/briarproject/bramble/lifecycle/LifecycleManagerImplTest.java

@@ -42,6 +42,7 @@ public class LifecycleManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).open(dbKey, lifecycleManager);
 			will(returnValue(false));
 			oneOf(db).transaction(with(false), withDbRunnable(txn));
+			oneOf(db).removeTemporaryMessages(txn);
 			allowing(eventBus).broadcast(with(any(LifecycleEvent.class)));
 		}});
 

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

@@ -637,7 +637,8 @@ public class TransportPropertyManagerImplTest extends BrambleMockTestCase {
 			will(returnValue(timestamp));
 			oneOf(clientHelper).createMessage(g, timestamp, body);
 			will(returnValue(message));
-			oneOf(clientHelper).addLocalMessage(txn, message, meta, shared);
+			oneOf(clientHelper).addLocalMessage(txn, message, meta, shared,
+					false);
 		}});
 	}
 }

bramble-core/src/test/java/org/briarproject/bramble/rendezvous/RendezvousPollerImplTest.java

@@ -45,6 +45,7 @@ import static java.util.Collections.singletonList;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
 import static org.briarproject.bramble.api.contact.PendingContactState.ADDING_CONTACT;
 import static org.briarproject.bramble.api.contact.PendingContactState.FAILED;
+import static org.briarproject.bramble.api.contact.PendingContactState.OFFLINE;
 import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.rendezvous.RendezvousConstants.POLLING_INTERVAL_MS;
 import static org.briarproject.bramble.rendezvous.RendezvousConstants.RENDEZVOUS_TIMEOUT_MS;
@@ -120,7 +121,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 			will(returnValue(beforeExpiry));
 			oneOf(eventBus).broadcast(with(new PredicateMatcher<>(
 					PendingContactStateChangedEvent.class, e ->
-					e.getPendingContactState() == WAITING_FOR_CONNECTION)));
+					e.getPendingContactState() == OFFLINE)));
 			// Capture the poll task
 			oneOf(scheduler).scheduleAtFixedRate(with(any(Runnable.class)),
 					with(POLLING_INTERVAL_MS), with(POLLING_INTERVAL_MS),
@@ -184,7 +185,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		context.assertIsSatisfied();
 
 		// Add the pending contact - endpoint should be created and polled
-		expectAddUnexpiredPendingContact(beforeExpiry);
+		expectAddPendingContact(beforeExpiry, WAITING_FOR_CONNECTION);
 		expectDeriveRendezvousKey();
 		expectCreateEndpoint();
 
@@ -205,9 +206,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		context.assertIsSatisfied();
 
 		// Remove the pending contact - endpoint should be closed
-		context.checking(new Expectations() {{
-			oneOf(rendezvousEndpoint).close();
-		}});
+		expectCloseEndpoint();
 
 		rendezvousPoller.eventOccurred(
 				new PendingContactRemovedEvent(pendingContact.getId()));
@@ -238,7 +237,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		context.assertIsSatisfied();
 
 		// Add the pending contact - endpoint should be created and polled
-		expectAddUnexpiredPendingContact(beforeExpiry);
+		expectAddPendingContact(beforeExpiry, WAITING_FOR_CONNECTION);
 		expectDeriveRendezvousKey();
 		expectCreateEndpoint();
 
@@ -260,10 +259,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 
 		// Run the poll task - pending contact expires, endpoint is closed
 		expectPendingContactExpires(afterExpiry);
-
-		context.checking(new Expectations() {{
-			oneOf(rendezvousEndpoint).close();
-		}});
+		expectCloseEndpoint();
 
 		capturePollTask.get().run();
 		context.assertIsSatisfied();
@@ -289,7 +285,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		context.assertIsSatisfied();
 
 		// Add the pending contact - no endpoints should be created yet
-		expectAddUnexpiredPendingContact(beforeExpiry);
+		expectAddPendingContact(beforeExpiry, OFFLINE);
 		expectDeriveRendezvousKey();
 
 		rendezvousPoller.eventOccurred(
@@ -299,14 +295,14 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		// Enable the transport - endpoint should be created
 		expectGetPlugin();
 		expectCreateEndpoint();
+		expectStateChangedEvent(WAITING_FOR_CONNECTION);
 
 		rendezvousPoller.eventOccurred(new TransportEnabledEvent(transportId));
 		context.assertIsSatisfied();
 
 		// Disable the transport - endpoint should be closed
-		context.checking(new Expectations() {{
-			oneOf(rendezvousEndpoint).close();
-		}});
+		expectCloseEndpoint();
+		expectStateChangedEvent(OFFLINE);
 
 		rendezvousPoller.eventOccurred(new TransportDisabledEvent(transportId));
 		context.assertIsSatisfied();
@@ -482,13 +478,14 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 		return capturePollTask;
 	}
 
-	private void expectAddUnexpiredPendingContact(long now) {
+	private void expectAddPendingContact(long now,
+			PendingContactState initialState) {
 		context.checking(new Expectations() {{
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
 			oneOf(eventBus).broadcast(with(new PredicateMatcher<>(
 					PendingContactStateChangedEvent.class, e ->
-					e.getPendingContactState() == WAITING_FOR_CONNECTION)));
+					e.getPendingContactState() == initialState)));
 		}});
 	}
 
@@ -546,7 +543,7 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 			will(returnValue(now));
 			oneOf(eventBus).broadcast(with(new PredicateMatcher<>(
 					PendingContactStateChangedEvent.class, e ->
-					e.getPendingContactState() == WAITING_FOR_CONNECTION)));
+					e.getPendingContactState() == OFFLINE)));
 			// Capture the poll task
 			oneOf(scheduler).scheduleAtFixedRate(with(any(Runnable.class)),
 					with(POLLING_INTERVAL_MS), with(POLLING_INTERVAL_MS),
@@ -576,4 +573,10 @@ public class RendezvousPollerImplTest extends BrambleMockTestCase {
 					e.getPendingContactState() == state)));
 		}});
 	}
+
+	private void expectCloseEndpoint() throws Exception {
+		context.checking(new Expectations() {{
+			oneOf(rendezvousEndpoint).close();
+		}});
+	}
 }

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

@@ -9,6 +9,7 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.SyncRecordWriter;
+import org.briarproject.bramble.api.sync.Versions;
 import org.briarproject.bramble.api.transport.StreamWriter;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.DbExpectations;
@@ -49,6 +50,8 @@ public class SimplexOutgoingSessionTest extends BrambleMockTestCase {
 		context.checking(new DbExpectations() {{
 			// Add listener
 			oneOf(eventBus).addListener(session);
+			// Send the protocol versions
+			oneOf(recordWriter).writeVersions(with(any(Versions.class)));
 			// No acks to send
 			oneOf(db).transactionWithNullableResult(with(false),
 					withNullableDbCallable(noAckTxn));
@@ -83,6 +86,8 @@ public class SimplexOutgoingSessionTest extends BrambleMockTestCase {
 		context.checking(new DbExpectations() {{
 			// Add listener
 			oneOf(eventBus).addListener(session);
+			// Send the protocol versions
+			oneOf(recordWriter).writeVersions(with(any(Versions.class)));
 			// One ack to send
 			oneOf(db).transactionWithNullableResult(with(false),
 					withNullableDbCallable(ackTxn));

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.sync;
 
+import org.briarproject.bramble.BrambleCoreEagerSingletons;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.TransportCrypto;
@@ -72,7 +73,7 @@ public class SyncIntegrationTest extends BrambleTestCase {
 
 		SyncIntegrationTestComponent component =
 				DaggerSyncIntegrationTestComponent.builder().build();
-		component.injectBrambleCoreEagerSingletons();
+		BrambleCoreEagerSingletons.Helper.injectEagerSingletons(component);
 		component.inject(this);
 
 		contactId = getContactId();

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

@@ -10,11 +10,14 @@ import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.Offer;
 import org.briarproject.bramble.api.sync.Request;
 import org.briarproject.bramble.api.sync.SyncRecordReader;
+import org.briarproject.bramble.api.sync.Versions;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.jmock.Expectations;
+import org.junit.Before;
 import org.junit.Test;
 
 import java.io.ByteArrayOutputStream;
+import java.util.List;
 
 import javax.annotation.Nullable;
 
@@ -22,7 +25,9 @@ import static org.briarproject.bramble.api.record.Record.MAX_RECORD_PAYLOAD_BYTE
 import static org.briarproject.bramble.api.sync.RecordTypes.ACK;
 import static org.briarproject.bramble.api.sync.RecordTypes.OFFER;
 import static org.briarproject.bramble.api.sync.RecordTypes.REQUEST;
+import static org.briarproject.bramble.api.sync.RecordTypes.VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_IDS;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_SUPPORTED_VERSIONS;
 import static org.briarproject.bramble.api.sync.SyncConstants.PROTOCOL_VERSION;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.junit.Assert.assertEquals;
@@ -35,12 +40,17 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 			context.mock(MessageFactory.class);
 	private final RecordReader recordReader = context.mock(RecordReader.class);
 
+	private SyncRecordReader reader;
+
+	@Before
+	public void setUp() {
+		reader = new SyncRecordReaderImpl(messageFactory, recordReader);
+	}
+
 	@Test
 	public void testNoFormatExceptionIfAckIsMaximumSize() throws Exception {
 		expectReadRecord(createAck());
 
-		SyncRecordReader reader =
-				new SyncRecordReaderImpl(messageFactory, recordReader);
 		Ack ack = reader.readAck();
 		assertEquals(MAX_MESSAGE_IDS, ack.getMessageIds().size());
 	}
@@ -49,8 +59,6 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 	public void testFormatExceptionIfAckIsEmpty() throws Exception {
 		expectReadRecord(createEmptyAck());
 
-		SyncRecordReader reader =
-				new SyncRecordReaderImpl(messageFactory, recordReader);
 		reader.readAck();
 	}
 
@@ -58,8 +66,6 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 	public void testNoFormatExceptionIfOfferIsMaximumSize() throws Exception {
 		expectReadRecord(createOffer());
 
-		SyncRecordReader reader =
-				new SyncRecordReaderImpl(messageFactory, recordReader);
 		Offer offer = reader.readOffer();
 		assertEquals(MAX_MESSAGE_IDS, offer.getMessageIds().size());
 	}
@@ -68,8 +74,6 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 	public void testFormatExceptionIfOfferIsEmpty() throws Exception {
 		expectReadRecord(createEmptyOffer());
 
-		SyncRecordReader reader =
-				new SyncRecordReaderImpl(messageFactory, recordReader);
 		reader.readOffer();
 	}
 
@@ -77,8 +81,6 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 	public void testNoFormatExceptionIfRequestIsMaximumSize() throws Exception {
 		expectReadRecord(createRequest());
 
-		SyncRecordReader reader =
-				new SyncRecordReaderImpl(messageFactory, recordReader);
 		Request request = reader.readRequest();
 		assertEquals(MAX_MESSAGE_IDS, request.getMessageIds().size());
 	}
@@ -87,11 +89,36 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 	public void testFormatExceptionIfRequestIsEmpty() throws Exception {
 		expectReadRecord(createEmptyRequest());
 
-		SyncRecordReader reader =
-				new SyncRecordReaderImpl(messageFactory, recordReader);
 		reader.readRequest();
 	}
 
+	@Test
+	public void testNoFormatExceptionIfVersionsIsMaximumSize()
+			throws Exception {
+		expectReadRecord(createVersions(MAX_SUPPORTED_VERSIONS));
+
+		Versions versions = reader.readVersions();
+		List<Byte> supported = versions.getSupportedVersions();
+		assertEquals(MAX_SUPPORTED_VERSIONS, supported.size());
+		for (int i = 0; i < supported.size(); i++) {
+			assertEquals(i, (int) supported.get(i));
+		}
+	}
+
+	@Test(expected = FormatException.class)
+	public void testFormatExceptionIfVersionsIsEmpty() throws Exception {
+		expectReadRecord(createVersions(0));
+
+		reader.readVersions();
+	}
+
+	@Test(expected = FormatException.class)
+	public void testFormatExceptionIfVersionsIsTooLarge() throws Exception {
+		expectReadRecord(createVersions(MAX_SUPPORTED_VERSIONS + 1));
+
+		reader.readVersions();
+	}
+
 	@Test
 	public void testEofReturnsTrueWhenAtEndOfStream() throws Exception {
 		expectReadRecord(createAck());
@@ -140,6 +167,12 @@ public class SyncRecordReaderImplTest extends BrambleMockTestCase {
 		return new Record(PROTOCOL_VERSION, REQUEST, new byte[0]);
 	}
 
+	private Record createVersions(int numVersions) {
+		byte[] payload = new byte[numVersions];
+		for (int i = 0; i < payload.length; i++) payload[i] = (byte) i;
+		return new Record(PROTOCOL_VERSION, VERSIONS, payload);
+	}
+
 	private byte[] createPayload() throws Exception {
 		ByteArrayOutputStream payload = new ByteArrayOutputStream();
 		while (payload.size() + UniqueId.LENGTH <= MAX_RECORD_PAYLOAD_BYTES) {

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

@@ -28,7 +28,6 @@ import java.util.Map;
 import java.util.concurrent.Executor;
 
 import static java.util.Arrays.asList;
-import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
@@ -80,24 +79,9 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 
 	@Test
 	public void testStartAndStop() throws Exception {
-		Transaction txn = new Transaction(null, true);
-		Transaction txn1 = new Transaction(null, true);
-		Transaction txn2 = new Transaction(null, true);
-
-		context.checking(new DbExpectations() {{
-			// validateOutstandingMessages()
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getMessagesToValidate(txn);
-			will(returnValue(emptyList()));
-			// deliverOutstandingMessages()
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn1));
-			oneOf(db).getPendingMessages(txn1);
-			will(returnValue(emptyList()));
-			// shareOutstandingMessages()
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn2));
-			oneOf(db).getMessagesToShare(txn2);
-			will(returnValue(emptyList()));
-		}});
+		expectGetMessagesToValidate();
+		expectGetPendingMessages();
+		expectGetMessagesToShare();
 
 		vm.startService();
 		vm.stopService();
@@ -106,167 +90,134 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testMessagesAreValidatedAtStartup() throws Exception {
 		Transaction txn = new Transaction(null, true);
-		Transaction txn1 = new Transaction(null, true);
-		Transaction txn2 = new Transaction(null, false);
-		Transaction txn3 = new Transaction(null, true);
-		Transaction txn4 = new Transaction(null, false);
-		Transaction txn5 = new Transaction(null, true);
-		Transaction txn6 = new Transaction(null, true);
+		Transaction txn1 = new Transaction(null, false);
+		Transaction txn2 = new Transaction(null, true);
+		Transaction txn3 = new Transaction(null, false);
+
+		expectGetMessagesToValidate(messageId, messageId1);
 
 		context.checking(new DbExpectations() {{
-			// Get messages to validate
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getMessagesToValidate(txn);
-			will(returnValue(asList(messageId, messageId1)));
 			// Load the first raw message and group
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn1));
-			oneOf(db).getMessage(txn1, messageId);
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(db).getMessage(txn, messageId);
 			will(returnValue(message));
-			oneOf(db).getGroup(txn1, groupId);
+			oneOf(db).getGroup(txn, groupId);
 			will(returnValue(group));
 			// Validate the first message: valid
 			oneOf(validator).validateMessage(message, group);
 			will(returnValue(validResult));
 			// Store the validation result for the first message
-			oneOf(db).transaction(with(false), withDbRunnable(txn2));
-			oneOf(db).mergeMessageMetadata(txn2, messageId, metadata);
+			oneOf(db).transaction(with(false), withDbRunnable(txn1));
+			oneOf(db).mergeMessageMetadata(txn1, messageId, metadata);
 			// Deliver the first message
-			oneOf(hook).incomingMessage(txn2, message, metadata);
+			oneOf(hook).incomingMessage(txn1, message, metadata);
 			will(returnValue(false));
-			oneOf(db).setMessageState(txn2, messageId, DELIVERED);
+			oneOf(db).setMessageState(txn1, messageId, DELIVERED);
 			// Get any pending dependents
-			oneOf(db).getMessageDependents(txn2, messageId);
+			oneOf(db).getMessageDependents(txn1, messageId);
 			will(returnValue(emptyMap()));
 			// Load the second raw message and group
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn3));
-			oneOf(db).getMessage(txn3, messageId1);
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn2));
+			oneOf(db).getMessage(txn2, messageId1);
 			will(returnValue(message1));
-			oneOf(db).getGroup(txn3, groupId);
+			oneOf(db).getGroup(txn2, groupId);
 			will(returnValue(group));
 			// Validate the second message: invalid
 			oneOf(validator).validateMessage(message1, group);
 			will(throwException(new InvalidMessageException()));
 			// Store the validation result for the second message
-			oneOf(db).transaction(with(false), withDbRunnable(txn4));
-			oneOf(db).getMessageState(txn4, messageId1);
+			oneOf(db).transaction(with(false), withDbRunnable(txn3));
+			oneOf(db).getMessageState(txn3, messageId1);
 			will(returnValue(UNKNOWN));
-			oneOf(db).setMessageState(txn4, messageId1, INVALID);
-			oneOf(db).deleteMessage(txn4, messageId1);
-			oneOf(db).deleteMessageMetadata(txn4, messageId1);
+			oneOf(db).setMessageState(txn3, messageId1, INVALID);
+			oneOf(db).deleteMessage(txn3, messageId1);
+			oneOf(db).deleteMessageMetadata(txn3, messageId1);
 			// Recursively invalidate any dependents
-			oneOf(db).getMessageDependents(txn4, messageId1);
+			oneOf(db).getMessageDependents(txn3, messageId1);
 			will(returnValue(emptyMap()));
-			// Get pending messages to deliver
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn5));
-			oneOf(db).getPendingMessages(txn5);
-			will(returnValue(emptyList()));
-			// Get messages to share
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn6));
-			oneOf(db).getMessagesToShare(txn6);
-			will(returnValue(emptyList()));
 		}});
 
+		expectGetPendingMessages();
+		expectGetMessagesToShare();
+
 		vm.startService();
 	}
 
 	@Test
 	public void testPendingMessagesAreDeliveredAtStartup() throws Exception {
-		Transaction txn = new Transaction(null, true);
-		Transaction txn1 = new Transaction(null, true);
-		Transaction txn2 = new Transaction(null, false);
-		Transaction txn3 = new Transaction(null, false);
-		Transaction txn4 = new Transaction(null, true);
+		Transaction txn = new Transaction(null, false);
+		Transaction txn1 = new Transaction(null, false);
+
+		expectGetMessagesToValidate();
+		expectGetPendingMessages(messageId);
 
 		context.checking(new DbExpectations() {{
-			// Get messages to validate
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getMessagesToValidate(txn);
-			will(returnValue(emptyList()));
-			// Get pending messages to deliver
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn1));
-			oneOf(db).getPendingMessages(txn1);
-			will(returnValue(singletonList(messageId)));
 			// Check whether the message is ready to deliver
-			oneOf(db).transaction(with(false), withDbRunnable(txn2));
-			oneOf(db).getMessageState(txn2, messageId);
+			oneOf(db).transaction(with(false), withDbRunnable(txn));
+			oneOf(db).getMessageState(txn, messageId);
 			will(returnValue(PENDING));
-			oneOf(db).getMessageDependencies(txn2, messageId);
+			oneOf(db).getMessageDependencies(txn, messageId);
 			will(returnValue(singletonMap(messageId1, DELIVERED)));
 			// Get the message and its metadata to deliver
-			oneOf(db).getMessage(txn2, messageId);
+			oneOf(db).getMessage(txn, messageId);
 			will(returnValue(message));
-			oneOf(db).getGroup(txn2, groupId);
+			oneOf(db).getGroup(txn, groupId);
 			will(returnValue(group));
-			oneOf(db).getMessageMetadataForValidator(txn2, messageId);
+			oneOf(db).getMessageMetadataForValidator(txn, messageId);
 			will(returnValue(new Metadata()));
 			// Deliver the message
-			oneOf(hook).incomingMessage(txn2, message, metadata);
+			oneOf(hook).incomingMessage(txn, message, metadata);
 			will(returnValue(false));
-			oneOf(db).setMessageState(txn2, messageId, DELIVERED);
+			oneOf(db).setMessageState(txn, messageId, DELIVERED);
 			// Get any pending dependents
-			oneOf(db).getMessageDependents(txn2, messageId);
+			oneOf(db).getMessageDependents(txn, messageId);
 			will(returnValue(singletonMap(messageId2, PENDING)));
 			// Check whether the dependent is ready to deliver
-			oneOf(db).transaction(with(false), withDbRunnable(txn3));
-			oneOf(db).getMessageState(txn3, messageId2);
+			oneOf(db).transaction(with(false), withDbRunnable(txn1));
+			oneOf(db).getMessageState(txn1, messageId2);
 			will(returnValue(PENDING));
-			oneOf(db).getMessageDependencies(txn3, messageId2);
+			oneOf(db).getMessageDependencies(txn1, messageId2);
 			will(returnValue(singletonMap(messageId1, DELIVERED)));
 			// Get the dependent and its metadata to deliver
-			oneOf(db).getMessage(txn3, messageId2);
+			oneOf(db).getMessage(txn1, messageId2);
 			will(returnValue(message2));
-			oneOf(db).getGroup(txn3, groupId);
+			oneOf(db).getGroup(txn1, groupId);
 			will(returnValue(group));
-			oneOf(db).getMessageMetadataForValidator(txn3, messageId2);
+			oneOf(db).getMessageMetadataForValidator(txn1, messageId2);
 			will(returnValue(metadata));
 			// Deliver the dependent
-			oneOf(hook).incomingMessage(txn3, message2, metadata);
+			oneOf(hook).incomingMessage(txn1, message2, metadata);
 			will(returnValue(false));
-			oneOf(db).setMessageState(txn3, messageId2, DELIVERED);
+			oneOf(db).setMessageState(txn1, messageId2, DELIVERED);
 			// Get any pending dependents
-			oneOf(db).getMessageDependents(txn3, messageId2);
+			oneOf(db).getMessageDependents(txn1, messageId2);
 			will(returnValue(emptyMap()));
-
-			// Get messages to share
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn4));
-			oneOf(db).getMessagesToShare(txn4);
-			will(returnValue(emptyList()));
 		}});
 
+		expectGetMessagesToShare();
+
 		vm.startService();
 	}
 
 	@Test
 	public void testMessagesAreSharedAtStartup() throws Exception {
-		Transaction txn = new Transaction(null, true);
-		Transaction txn1 = new Transaction(null, true);
-		Transaction txn2 = new Transaction(null, true);
-		Transaction txn3 = new Transaction(null, false);
-		Transaction txn4 = new Transaction(null, false);
+		Transaction txn = new Transaction(null, false);
+		Transaction txn1 = new Transaction(null, false);
+
+		expectGetMessagesToValidate();
+		expectGetPendingMessages();
+		expectGetMessagesToShare(messageId);
 
 		context.checking(new DbExpectations() {{
-			// No messages to validate
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getMessagesToValidate(txn);
-			will(returnValue(emptyList()));
-			// No pending messages to deliver
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn1));
-			oneOf(db).getPendingMessages(txn1);
-			will(returnValue(emptyList()));
-
-			// Get messages to share
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn2));
-			oneOf(db).getMessagesToShare(txn2);
-			will(returnValue(singletonList(messageId)));
 			// Share message and get dependencies
-			oneOf(db).transaction(with(false), withDbRunnable(txn3));
-			oneOf(db).setMessageShared(txn3, messageId);
-			oneOf(db).getMessageDependencies(txn3, messageId);
+			oneOf(db).transaction(with(false), withDbRunnable(txn));
+			oneOf(db).setMessageShared(txn, messageId);
+			oneOf(db).getMessageDependencies(txn, messageId);
 			will(returnValue(singletonMap(messageId2, DELIVERED)));
 			// Share dependency
-			oneOf(db).transaction(with(false), withDbRunnable(txn4));
-			oneOf(db).setMessageShared(txn4, messageId2);
-			oneOf(db).getMessageDependencies(txn4, messageId2);
+			oneOf(db).transaction(with(false), withDbRunnable(txn1));
+			oneOf(db).setMessageShared(txn1, messageId2);
+			oneOf(db).getMessageDependencies(txn1, messageId2);
 			will(returnValue(emptyMap()));
 		}});
 
@@ -318,49 +269,39 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 			throws Exception {
 		Transaction txn = new Transaction(null, true);
 		Transaction txn1 = new Transaction(null, true);
-		Transaction txn2 = new Transaction(null, true);
-		Transaction txn3 = new Transaction(null, false);
-		Transaction txn4 = new Transaction(null, true);
-		Transaction txn5 = new Transaction(null, true);
+		Transaction txn2 = new Transaction(null, false);
+
+		expectGetMessagesToValidate(messageId, messageId1);
 
 		context.checking(new DbExpectations() {{
-			// Get messages to validate
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getMessagesToValidate(txn);
-			will(returnValue(asList(messageId, messageId1)));
 			// Load the first raw message - *gasp* it's gone!
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn1));
-			oneOf(db).getMessage(txn1, messageId);
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(db).getMessage(txn, messageId);
 			will(throwException(new NoSuchMessageException()));
 			// Load the second raw message and group
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn2));
-			oneOf(db).getMessage(txn2, messageId1);
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn1));
+			oneOf(db).getMessage(txn1, messageId1);
 			will(returnValue(message1));
-			oneOf(db).getGroup(txn2, groupId);
+			oneOf(db).getGroup(txn1, groupId);
 			will(returnValue(group));
 			// Validate the second message: invalid
 			oneOf(validator).validateMessage(message1, group);
 			will(throwException(new InvalidMessageException()));
 			// Invalidate the second message
-			oneOf(db).transaction(with(false), withDbRunnable(txn3));
-			oneOf(db).getMessageState(txn3, messageId1);
+			oneOf(db).transaction(with(false), withDbRunnable(txn2));
+			oneOf(db).getMessageState(txn2, messageId1);
 			will(returnValue(UNKNOWN));
-			oneOf(db).setMessageState(txn3, messageId1, INVALID);
-			oneOf(db).deleteMessage(txn3, messageId1);
-			oneOf(db).deleteMessageMetadata(txn3, messageId1);
+			oneOf(db).setMessageState(txn2, messageId1, INVALID);
+			oneOf(db).deleteMessage(txn2, messageId1);
+			oneOf(db).deleteMessageMetadata(txn2, messageId1);
 			// Recursively invalidate dependents
-			oneOf(db).getMessageDependents(txn3, messageId1);
+			oneOf(db).getMessageDependents(txn2, messageId1);
 			will(returnValue(emptyMap()));
-			// Get pending messages to deliver
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn4));
-			oneOf(db).getPendingMessages(txn4);
-			will(returnValue(emptyList()));
-			// Get messages to share
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn5));
-			oneOf(db).getMessagesToShare(txn5);
-			will(returnValue(emptyList()));
 		}});
 
+		expectGetPendingMessages();
+		expectGetMessagesToShare();
+
 		vm.startService();
 	}
 
@@ -369,52 +310,42 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 			throws Exception {
 		Transaction txn = new Transaction(null, true);
 		Transaction txn1 = new Transaction(null, true);
-		Transaction txn2 = new Transaction(null, true);
-		Transaction txn3 = new Transaction(null, false);
-		Transaction txn4 = new Transaction(null, true);
-		Transaction txn5 = new Transaction(null, true);
+		Transaction txn2 = new Transaction(null, false);
+
+		expectGetMessagesToValidate(messageId, messageId1);
 
 		context.checking(new DbExpectations() {{
-			// Get messages to validate
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
-			oneOf(db).getMessagesToValidate(txn);
-			will(returnValue(asList(messageId, messageId1)));
 			// Load the first raw message
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn1));
-			oneOf(db).getMessage(txn1, messageId);
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(db).getMessage(txn, messageId);
 			will(returnValue(message));
 			// Load the group - *gasp* it's gone!
-			oneOf(db).getGroup(txn1, groupId);
+			oneOf(db).getGroup(txn, groupId);
 			will(throwException(new NoSuchGroupException()));
 			// Load the second raw message and group
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn2));
-			oneOf(db).getMessage(txn2, messageId1);
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn1));
+			oneOf(db).getMessage(txn1, messageId1);
 			will(returnValue(message1));
-			oneOf(db).getGroup(txn2, groupId);
+			oneOf(db).getGroup(txn1, groupId);
 			will(returnValue(group));
 			// Validate the second message: invalid
 			oneOf(validator).validateMessage(message1, group);
 			will(throwException(new InvalidMessageException()));
 			// Store the validation result for the second message
-			oneOf(db).transaction(with(false), withDbRunnable(txn3));
-			oneOf(db).getMessageState(txn3, messageId1);
+			oneOf(db).transaction(with(false), withDbRunnable(txn2));
+			oneOf(db).getMessageState(txn2, messageId1);
 			will(returnValue(UNKNOWN));
-			oneOf(db).setMessageState(txn3, messageId1, INVALID);
-			oneOf(db).deleteMessage(txn3, messageId1);
-			oneOf(db).deleteMessageMetadata(txn3, messageId1);
+			oneOf(db).setMessageState(txn2, messageId1, INVALID);
+			oneOf(db).deleteMessage(txn2, messageId1);
+			oneOf(db).deleteMessageMetadata(txn2, messageId1);
 			// Recursively invalidate dependents
-			oneOf(db).getMessageDependents(txn3, messageId1);
+			oneOf(db).getMessageDependents(txn2, messageId1);
 			will(returnValue(emptyMap()));
-			// Get pending messages to deliver
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn4));
-			oneOf(db).getPendingMessages(txn4);
-			will(returnValue(emptyList()));
-			// Get messages to share
-			oneOf(db).transactionWithResult(with(true), withDbCallable(txn5));
-			oneOf(db).getMessagesToShare(txn5);
-			will(returnValue(emptyList()));
 		}});
 
+		expectGetPendingMessages();
+		expectGetMessagesToShare();
+
 		vm.startService();
 	}
 
@@ -801,4 +732,35 @@ public class ValidationManagerImplTest extends BrambleMockTestCase {
 
 		vm.eventOccurred(new MessageAddedEvent(message, contactId));
 	}
+
+	private void expectGetMessagesToValidate(MessageId... ids)
+			throws Exception {
+		Transaction txn = new Transaction(null, true);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(db).getMessagesToValidate(txn);
+			will(returnValue(asList(ids)));
+		}});
+	}
+
+	private void expectGetPendingMessages(MessageId... ids) throws Exception {
+		Transaction txn = new Transaction(null, true);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(db).getPendingMessages(txn);
+			will(returnValue(asList(ids)));
+		}});
+	}
+
+	private void expectGetMessagesToShare(MessageId... ids) throws Exception {
+		Transaction txn = new Transaction(null, true);
+
+		context.checking(new DbExpectations() {{
+			oneOf(db).transactionWithResult(with(true), withDbCallable(txn));
+			oneOf(db).getMessagesToShare(txn);
+			will(returnValue(asList(ids)));
+		}});
+	}
 }

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

@@ -1,9 +1,11 @@
 package org.briarproject.bramble.test;
 
+import org.briarproject.bramble.api.FeatureFlags;
 import org.briarproject.bramble.battery.DefaultBatteryManagerModule;
 import org.briarproject.bramble.event.DefaultEventExecutorModule;
 
 import dagger.Module;
+import dagger.Provides;
 
 @Module(includes = {
 		DefaultBatteryManagerModule.class,
@@ -13,4 +15,9 @@ import dagger.Module;
 		TestSecureRandomModule.class
 })
 public class BrambleCoreIntegrationTestModule {
+
+	@Provides
+	FeatureFlags provideFeatureFlags() {
+		return () -> true;
+	}
 }

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

@@ -1,10 +1,13 @@
 package org.briarproject.bramble.test;
 
+import org.briarproject.bramble.api.crypto.KeyStrengthener;
 import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.File;
 
+import javax.annotation.Nullable;
+
 @NotNullByDefault
 public class TestDatabaseConfig implements DatabaseConfig {
 
@@ -24,4 +27,10 @@ public class TestDatabaseConfig implements DatabaseConfig {
 	public File getDatabaseKeyDirectory() {
 		return keyDir;
 	}
+
+	@Nullable
+	@Override
+	public KeyStrengthener getKeyStrengthener() {
+		return null;
+	}
 }

bramble-core/src/test/java/org/briarproject/bramble/versioning/ClientVersioningManagerImplTest.java

@@ -60,6 +60,8 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 	private final ClientId clientId = getClientId();
 	private final long now = System.currentTimeMillis();
 	private final Transaction txn = new Transaction(null, false);
+	private final BdfDictionary groupMeta = BdfDictionary.of(
+			new BdfEntry(GROUP_KEY_CONTACT_ID, contact.getId().getInt()));
 
 	private ClientVersioningManagerImpl createInstance() {
 		context.checking(new Expectations() {{
@@ -107,8 +109,6 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 	}
 
 	private void expectAddingContact() throws Exception {
-		BdfDictionary groupMeta = BdfDictionary.of(
-				new BdfEntry(GROUP_KEY_CONTACT_ID, contact.getId().getInt()));
 		long now = System.currentTimeMillis();
 		BdfList localUpdateBody = BdfList.of(new BdfList(), 1L);
 		Message localUpdate = getMessage(contactGroup.getId());
@@ -131,7 +131,7 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 					localUpdateBody);
 			will(returnValue(localUpdate));
 			oneOf(clientHelper).addLocalMessage(txn, localUpdate,
-					localUpdateMeta, true);
+					localUpdateMeta, true, false);
 		}});
 	}
 
@@ -172,7 +172,7 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 					localVersionsBody);
 			will(returnValue(localVersions));
 			oneOf(db).addLocalMessage(txn, localVersions, new Metadata(),
-					false);
+					false, false);
 			// Inform contacts that client versions have changed
 			oneOf(db).getContacts(txn);
 			will(returnValue(singletonList(contact)));
@@ -259,7 +259,7 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 					newLocalVersionsBody);
 			will(returnValue(newLocalVersions));
 			oneOf(db).addLocalMessage(txn, newLocalVersions, new Metadata(),
-					false);
+					false, false);
 			// Inform contacts that client versions have changed
 			oneOf(db).getContacts(txn);
 			will(returnValue(singletonList(contact)));
@@ -284,7 +284,7 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 					newLocalUpdateBody);
 			will(returnValue(newLocalUpdate));
 			oneOf(clientHelper).addLocalMessage(txn, newLocalUpdate,
-					newLocalUpdateMeta, true);
+					newLocalUpdateMeta, true, false);
 			// No visibilities have changed
 		}});
 
@@ -355,7 +355,7 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 					newLocalVersionsBody);
 			will(returnValue(newLocalVersions));
 			oneOf(db).addLocalMessage(txn, newLocalVersions, new Metadata(),
-					false);
+					false, false);
 			// Inform contacts that client versions have changed
 			oneOf(db).getContacts(txn);
 			will(returnValue(singletonList(contact)));
@@ -382,7 +382,7 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 					newLocalUpdateBody);
 			will(returnValue(newLocalUpdate));
 			oneOf(clientHelper).addLocalMessage(txn, newLocalUpdate,
-					newLocalUpdateMeta, true);
+					newLocalUpdateMeta, true, false);
 			// The client's visibility has changed
 			oneOf(hook).onClientVisibilityChanging(txn, contact, visibility);
 		}});
@@ -459,6 +459,10 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			// Delete the old remote update
 			oneOf(db).deleteMessage(txn, oldRemoteUpdateId);
 			oneOf(db).deleteMessageMetadata(txn, oldRemoteUpdateId);
+			// Get contact ID
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			// No states or visibilities have changed
 		}});
 
@@ -488,6 +492,10 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			// Load the latest local update
 			oneOf(clientHelper).getMessageAsList(txn, oldLocalUpdateId);
 			will(returnValue(oldLocalUpdateBody));
+			// Get client ID
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			// No states or visibilities have changed
 		}});
 
@@ -567,7 +575,7 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 					newLocalUpdateBody);
 			will(returnValue(newLocalUpdate));
 			oneOf(clientHelper).addLocalMessage(txn, newLocalUpdate,
-					newLocalUpdateMeta, true);
+					newLocalUpdateMeta, true, false);
 			// The client's visibility has changed
 			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
 					contactGroup.getId());
@@ -640,7 +648,7 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 					newLocalUpdateBody);
 			will(returnValue(newLocalUpdate));
 			oneOf(clientHelper).addLocalMessage(txn, newLocalUpdate,
-					newLocalUpdateMeta, true);
+					newLocalUpdateMeta, true, false);
 			// The client's visibility has changed
 			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
 					contactGroup.getId());

bramble-core/witness.gradle

@@ -1,15 +1,17 @@
 dependencyVerification {
     verify = [
         'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
-        'com.google.code.findbugs:jsr305:1.3.9:jsr305-1.3.9.jar:905721a0eea90a81534abb7ee6ef4ea2e5e645fa1def0a5cd88402df1b46c9ed',
-        'com.google.dagger:dagger-compiler:2.22.1:dagger-compiler-2.22.1.jar:e5f28302cbe70a79d3620cddebfb8ec0736814f3980ffe1e673bfe3342f507d3',
-        'com.google.dagger:dagger-producers:2.22.1:dagger-producers-2.22.1.jar:f834a0082014213a68ff06a0f048d750178d02196c58b0b15beb367d32b97e35',
-        'com.google.dagger:dagger-spi:2.22.1:dagger-spi-2.22.1.jar:4b0b922793b3bcb91b99fabb75dba77c68afd7ae4c5f0c4fd6ba681f0a291c7d',
-        'com.google.dagger:dagger:2.22.1:dagger-2.22.1.jar:329d4340f24c4f5717af016c097e90668bfea2a5376e6aa9964b01cef3fd241a',
-        'com.google.errorprone:error_prone_annotations:2.1.3:error_prone_annotations-2.1.3.jar:03d0329547c13da9e17c634d1049ea2ead093925e290567e1a364fd6b1fc7ff8',
+        'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+        'com.google.dagger:dagger-compiler:2.24:dagger-compiler-2.24.jar:3c5afb955fb188da485cb2c048eff37dce0e1530b9780a0f2f7187d16d1ccc1f',
+        'com.google.dagger:dagger-producers:2.24:dagger-producers-2.24.jar:f10f45b95191954d5d6b043fca9e62fb621d21bf70634b8f8476c7988b504c3a',
+        'com.google.dagger:dagger-spi:2.24:dagger-spi-2.24.jar:c038445d14dbcb4054e61bf49e05009edf26fce4fdc7ec1a9db544784f68e718',
+        'com.google.dagger:dagger:2.24:dagger-2.24.jar:550a6e46a6dfcdf1d764887b6090cea94f783327e50e5c73754f18facfc70b64',
+        'com.google.errorprone:error_prone_annotations:2.2.0:error_prone_annotations-2.2.0.jar:6ebd22ca1b9d8ec06d41de8d64e0596981d9607b42035f9ed374f9de271a481a',
         'com.google.errorprone:javac-shaded:9-dev-r4023-3:javac-shaded-9-dev-r4023-3.jar:65bfccf60986c47fbc17c9ebab0be626afc41741e0a6ec7109e0768817a36f30',
         'com.google.googlejavaformat:google-java-format:1.5:google-java-format-1.5.jar:aa19ad7850fb85178aa22f2fddb163b84d6ce4d0035872f30d4408195ca1144e',
-        'com.google.guava:guava:25.0-jre:guava-25.0-jre.jar:3fd4341776428c7e0e5c18a7c10de129475b69ab9d30aeafbb5c277bb6074fa9',
+        'com.google.guava:failureaccess:1.0.1:failureaccess-1.0.1.jar:a171ee4c734dd2da837e4b16be9df4661afab72a41adaf31eb84dfdaf936ca26',
+        'com.google.guava:guava:27.1-jre:guava-27.1-jre.jar:4a5aa70cc968a4d137e599ad37553e5cfeed2265e8c193476d7119036c536fe7',
+        'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava:listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:b372a037d4230aa57fbeffdef30fd6123f9c0c2db85d0aced00c91b974f33f99',
         'com.google.j2objc:j2objc-annotations:1.1:j2objc-annotations-1.1.jar:2994a7eb78f2710bd3d3bfb639b2c94e219cedac0d4d084d516e78c16dddecf6',
         'com.h2database:h2:1.4.192:h2-1.4.192.jar:225b22e9857235c46c93861410b60b8c81c10dc8985f4faf188985ba5445126c',
         'com.madgag.spongycastle:core:1.58.0.0:core-1.58.0.0.jar:199617dd5698c5a9312b898c0a4cec7ce9dd8649d07f65d91629f58229d72728',
@@ -18,14 +20,16 @@ dependencyVerification {
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
         'net.i2p.crypto:eddsa:0.2.0:eddsa-0.2.0.jar:a7cb1b85c16e2f0730b9204106929a1d9aaae1df728adc7041a8b8b605692140',
+        'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
         'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
         'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
         'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
         'org.bitlet:weupnp:0.1.4:weupnp-0.1.4.jar:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
         'org.briarproject:jtorctl:0.3:jtorctl-0.3.jar:f2939238a097898998432effe93b0334d97a787972ab3a91a8973a1d309fc864',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
+        'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
         'org.codehaus.mojo.signature:java16:1.1:java16-1.1.signature:53799223a2c98dba2d0add810bed76315460df285c69e4f397ae6098f87dd619',
-        'org.codehaus.mojo:animal-sniffer-annotations:1.14:animal-sniffer-annotations-1.14.jar:2068320bd6bad744c3673ab048f67e30bef8f518996fa380033556600669905d',
+        'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',
         'org.codehaus.mojo:animal-sniffer-ant-tasks:1.16:animal-sniffer-ant-tasks-1.16.jar:890040976fbe2d584619a6a61b1fd2e925b3b5eb342a85eb2762c467c0d64e90',
         'org.codehaus.mojo:animal-sniffer:1.16:animal-sniffer-1.16.jar:72be8bcc226ba43b937c722a08a07852bfa1b11400089265d5df0ee7b38b1d52',
         'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',

bramble-java/build.gradle

@@ -16,10 +16,10 @@ dependencies {
 	implementation fileTree(dir: 'libs', include: '*.jar')
 	implementation 'net.java.dev.jna:jna:4.5.2'
 	implementation 'net.java.dev.jna:jna-platform:4.5.2'
-	tor 'org.briarproject:tor:0.3.5.8@zip'
+	tor 'org.briarproject:tor:0.3.5.9@zip'
 	tor 'org.briarproject:obfs4proxy:0.0.7@zip'
 
-	annotationProcessor 'com.google.dagger:dagger-compiler:2.22.1'
+	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
 	testImplementation project(path: ':bramble-core', configuration: 'testOutput')
@@ -28,7 +28,7 @@ dependencies {
 	testImplementation "org.jmock:jmock-junit4:2.8.2"
 	testImplementation "org.jmock:jmock-legacy:2.8.2"
 
-	testAnnotationProcessor 'com.google.dagger:dagger-compiler:2.22.1'
+	testAnnotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 }
 
 def torBinariesDir = 'src/main/resources'

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.plugin.tor;
 
+import org.briarproject.bramble.BrambleCoreEagerSingletons;
 import org.briarproject.bramble.api.battery.BatteryManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
@@ -45,7 +46,7 @@ public class BridgeTest extends BrambleTestCase {
 	public static Iterable<String> data() {
 		BrambleJavaIntegrationTestComponent component =
 				DaggerBrambleJavaIntegrationTestComponent.builder().build();
-		component.injectBrambleCoreEagerSingletons();
+		BrambleCoreEagerSingletons.Helper.injectEagerSingletons(component);
 		return component.getCircumventionProvider().getBridges(false);
 	}
 
@@ -90,7 +91,7 @@ public class BridgeTest extends BrambleTestCase {
 
 		BrambleJavaIntegrationTestComponent component =
 				DaggerBrambleJavaIntegrationTestComponent.builder().build();
-		component.injectBrambleCoreEagerSingletons();
+		BrambleCoreEagerSingletons.Helper.injectEagerSingletons(component);
 		component.inject(this);
 
 		LocationUtils locationUtils = () -> "US";

bramble-java/witness.gradle

@@ -1,15 +1,17 @@
 dependencyVerification {
     verify = [
         'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
-        'com.google.code.findbugs:jsr305:1.3.9:jsr305-1.3.9.jar:905721a0eea90a81534abb7ee6ef4ea2e5e645fa1def0a5cd88402df1b46c9ed',
-        'com.google.dagger:dagger-compiler:2.22.1:dagger-compiler-2.22.1.jar:e5f28302cbe70a79d3620cddebfb8ec0736814f3980ffe1e673bfe3342f507d3',
-        'com.google.dagger:dagger-producers:2.22.1:dagger-producers-2.22.1.jar:f834a0082014213a68ff06a0f048d750178d02196c58b0b15beb367d32b97e35',
-        'com.google.dagger:dagger-spi:2.22.1:dagger-spi-2.22.1.jar:4b0b922793b3bcb91b99fabb75dba77c68afd7ae4c5f0c4fd6ba681f0a291c7d',
-        'com.google.dagger:dagger:2.22.1:dagger-2.22.1.jar:329d4340f24c4f5717af016c097e90668bfea2a5376e6aa9964b01cef3fd241a',
-        'com.google.errorprone:error_prone_annotations:2.1.3:error_prone_annotations-2.1.3.jar:03d0329547c13da9e17c634d1049ea2ead093925e290567e1a364fd6b1fc7ff8',
+        'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
+        'com.google.dagger:dagger-compiler:2.24:dagger-compiler-2.24.jar:3c5afb955fb188da485cb2c048eff37dce0e1530b9780a0f2f7187d16d1ccc1f',
+        'com.google.dagger:dagger-producers:2.24:dagger-producers-2.24.jar:f10f45b95191954d5d6b043fca9e62fb621d21bf70634b8f8476c7988b504c3a',
+        'com.google.dagger:dagger-spi:2.24:dagger-spi-2.24.jar:c038445d14dbcb4054e61bf49e05009edf26fce4fdc7ec1a9db544784f68e718',
+        'com.google.dagger:dagger:2.24:dagger-2.24.jar:550a6e46a6dfcdf1d764887b6090cea94f783327e50e5c73754f18facfc70b64',
+        'com.google.errorprone:error_prone_annotations:2.2.0:error_prone_annotations-2.2.0.jar:6ebd22ca1b9d8ec06d41de8d64e0596981d9607b42035f9ed374f9de271a481a',
         'com.google.errorprone:javac-shaded:9-dev-r4023-3:javac-shaded-9-dev-r4023-3.jar:65bfccf60986c47fbc17c9ebab0be626afc41741e0a6ec7109e0768817a36f30',
         'com.google.googlejavaformat:google-java-format:1.5:google-java-format-1.5.jar:aa19ad7850fb85178aa22f2fddb163b84d6ce4d0035872f30d4408195ca1144e',
-        'com.google.guava:guava:25.0-jre:guava-25.0-jre.jar:3fd4341776428c7e0e5c18a7c10de129475b69ab9d30aeafbb5c277bb6074fa9',
+        'com.google.guava:failureaccess:1.0.1:failureaccess-1.0.1.jar:a171ee4c734dd2da837e4b16be9df4661afab72a41adaf31eb84dfdaf936ca26',
+        'com.google.guava:guava:27.1-jre:guava-27.1-jre.jar:4a5aa70cc968a4d137e599ad37553e5cfeed2265e8c193476d7119036c536fe7',
+        'com.google.guava:listenablefuture:9999.0-empty-to-avoid-conflict-with-guava:listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar:b372a037d4230aa57fbeffdef30fd6123f9c0c2db85d0aced00c91b974f33f99',
         'com.google.j2objc:j2objc-annotations:1.1:j2objc-annotations-1.1.jar:2994a7eb78f2710bd3d3bfb639b2c94e219cedac0d4d084d516e78c16dddecf6',
         'com.squareup:javapoet:1.11.1:javapoet-1.11.1.jar:9cbf2107be499ec6e95afd36b58e3ca122a24166cdd375732e51267d64058e90',
         'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
@@ -17,13 +19,15 @@ dependencyVerification {
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
         'net.java.dev.jna:jna-platform:4.5.2:jna-platform-4.5.2.jar:f1d00c167d8921c6e23c626ef9f1c3ae0be473c95c68ffa012bc7ae55a87e2d6',
         'net.java.dev.jna:jna:4.5.2:jna-4.5.2.jar:0c8eb7acf67261656d79005191debaba3b6bf5dd60a43735a245429381dbecff',
+        'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
         'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
         'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
         'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
         'org.briarproject:obfs4proxy:0.0.7:obfs4proxy-0.0.7.zip:5b2f693262ce43a7e130f7cc7d5d1617925330640a2eb6d71085e95df8ee0642',
-        'org.briarproject:tor:0.3.5.8:tor-0.3.5.8.zip:96e83391f01984f28669235fc02fbb0243140a2b3b2c73aeffd0042c8d3ced18',
+        'org.briarproject:tor:0.3.5.9:tor-0.3.5.9.zip:6c3994b129db019cc23caaf50d6b4383903c40d05fbc47fc94211170a3e5d38c',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
-        'org.codehaus.mojo:animal-sniffer-annotations:1.14:animal-sniffer-annotations-1.14.jar:2068320bd6bad744c3673ab048f67e30bef8f518996fa380033556600669905d',
+        'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
+        'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',
         'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
         'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
         'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',

briar-android/.tx/config

@@ -1,6 +1,6 @@
 [main]
 host = https://www.transifex.com
-lang_map = pt_BR: pt-rBR, nb_NO: nb, zh-Hans: zh-rCN
+lang_map = pt_BR: pt-rBR, nb_NO: nb, zh-Hans: zh-rCN, zh-Hant: zh-rTW
 
 [briar.stringsxml-5]
 file_filter = src/main/res/values-<lang>/strings.xml

briar-android/artwork/briar-android_tv_artwork_logo_horizontal_black.svg

@@ -0,0 +1,123 @@
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+   sodipodi:docname="briar-android_tv_artwork_logo_horizontal_black.svg"
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+   inkscape:export-filename="C:\Users\hughi\Downloads\briar-android_tv_artwork_logo_horizontal_black.png"
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+     x="144.2" /><path
+     class="st2"
+     d="m 217.3,-82.8 c 9.7,0 17.7,7.9 17.7,17.7 v 8.3 c 0,9.7 -8,17.7 -17.7,17.7 H 17.7 C 8,-39.1 0,-47 0,-56.8 v -8.3 c 0,-9.7 7.9,-17.7 17.7,-17.7 h 199.6 m 0,-7 H 17.7 c -13.6,0 -24.7,11 -24.7,24.6 v 8.3 c 0,13.6 11.1,24.7 24.7,24.7 h 199.7 c 13.6,0 24.7,-11.1 24.7,-24.7 v -8.3 C 242,-78.8 230.9,-89.8 217.3,-89.8 Z"
+     id="path53"
+     inkscape:connector-curvature="0"
+     style="display:none;fill:#ffffff" /><path
+     inkscape:connector-curvature="0"
+     d="m 164.94845,130.5118 v 37.0142 h 17.3299 c 8.17094,0 12.45497,-4.0911 12.45497,-10.4911 0,-4.156 -1.91138,-7.2578 -5.73332,-8.9728 v -0.083 c 2.89934,-1.7808 4.15207,-4.0233 4.15207,-7.521 0,-5.2791 -3.62408,-9.9627 -11.26806,-9.9627 z m 35.97934,0 v 37.0142 h 4.34796 v -14.8454 l -0.45977,-0.4615 h 8.76264 c 4.87623,0 7.64484,1.7133 9.424,5.5433 l 4.61191,9.7636 h 4.87655 l -5.46909,-11.5461 c -1.18614,-2.5738 -3.0974,-4.2227 -4.81061,-4.9483 v -0.083 c 4.0196,-1.0565 7.38013,-4.6856 7.38013,-9.5024 0,-7.3236 -5.66649,-10.9515 -12.45366,-10.9515 z m 36.10959,0 v 37.0142 h 4.34922 v -37.0142 z m 25.56832,0 -16.27714,37.0142 h 4.74504 l 3.95341,-8.9069 -0.19703,-0.4619 h 20.2293 l -0.19713,0.4619 3.9535,8.9069 h 4.74491 l -16.34284,-37.0142 z m 25.82985,0 v 37.0142 h 4.34912 v -14.8454 l -0.4612,-0.4615 h 8.76406 c 4.87643,0 7.64485,1.7133 9.42429,5.5433 l 4.61186,9.7636 H 320 l -5.46903,-11.5461 c -1.18594,-2.5738 -3.09737,-4.2227 -4.81072,-4.9483 v -0.083 c 4.01975,-1.0565 7.38026,-4.6856 7.38026,-9.5024 0,-7.3236 -5.6664,-10.9515 -12.45361,-10.9515 z m -119.59919,4.0908 h 12.58636 c 4.7444,0 7.24733,1.9136 7.24733,5.8723 0,3.2982 -1.97576,5.9394 -7.24733,5.9394 h -12.58636 l 0.46124,-0.4633 v -10.8868 z m 35.97962,0 h 12.32187 c 4.48085,0 7.907,1.8468 7.97296,6.7961 0,3.9585 -3.09676,6.7292 -8.43423,6.7292 h -11.8606 l 0.45977,-0.4614 v -12.6023 z m 87.44177,0 h 12.32223 c 4.54673,0 7.97414,1.8468 7.97414,6.7961 0,3.9585 -3.09683,6.7292 -8.43417,6.7292 h -11.8622 l 0.46141,-0.4614 v -12.6023 z m -27.28106,0.4616 h 0.0674 l 1.11984,3.6954 6.52328,14.8464 0.46124,0.46 h -16.27578 l 0.46131,-0.46 6.52318,-14.8464 z m -96.14033,15.4387 h 13.44199 c 5.46934,0 7.97421,2.5073 7.97421,6.532 0,4.0908 -2.30722,6.401 -7.97421,6.401 h -13.44199 l 0.46124,-0.463 V 150.966 Z"
+     id="path57"
+     style="stroke-width:0.65979397" /></svg>

briar-android/build.gradle

@@ -16,14 +16,14 @@ def getStdout = { command, defaultValue ->
 }
 
 android {
-	compileSdkVersion 28
-	buildToolsVersion '28.0.3'
+	compileSdkVersion 29
+	buildToolsVersion '29.0.2'
 
 	defaultConfig {
-		minSdkVersion 15
-		targetSdkVersion 26
-		versionCode 10107
-		versionName "1.1.7"
+		minSdkVersion 16
+		targetSdkVersion 28
+		versionCode 10205
+		versionName "1.2.5"
 		applicationId "org.briarproject.briar.android"
 		buildConfigField "String", "GitHash",
 				"\"${getStdout(['git', 'rev-parse', '--short=7', 'HEAD'], 'No commit hash')}\""
@@ -31,6 +31,7 @@ android {
 		buildConfigField "Long", "BuildTimestamp",
 				"${getStdout(['git', 'log', '-n', '1', '--format=%ct'], now)}000L"
 		testInstrumentationRunner 'org.briarproject.briar.android.BriarTestRunner'
+		testInstrumentationRunnerArguments disableAnalytics: 'true'
 	}
 
 	buildTypes {
@@ -82,6 +83,8 @@ android {
 		warning 'MissingTranslation'
 		warning 'ImpliedQuantity'
 		warning 'ExtraTranslation'
+		// FIXME
+		warning 'InvalidPackage'
 	}
 }
 
@@ -90,66 +93,61 @@ dependencies {
 	implementation project(path: ':bramble-core', configuration: 'default')
 	implementation project(':bramble-android')
 
-	def supportVersion = '28.0.0'
-	implementation "com.android.support:support-v4:$supportVersion"
-	implementation("com.android.support:appcompat-v7:$supportVersion") {
-		exclude module: 'support-v4'
-	}
-	implementation("com.android.support:preference-v14:$supportVersion") {
-		exclude module: 'support-v4'
-	}
-	implementation("com.android.support:design:$supportVersion") {
-		exclude module: 'support-v4'
-		exclude module: 'recyclerview-v7'
-	}
-	implementation "com.android.support:cardview-v7:$supportVersion"
-	implementation "com.android.support:support-annotations:$supportVersion"
-	implementation "com.android.support:exifinterface:$supportVersion"
-	implementation 'com.android.support.constraint:constraint-layout:1.1.3'
-	implementation "android.arch.lifecycle:extensions:1.1.1"
+	implementation 'androidx.preference:preference:1.1.0'
+	implementation 'androidx.exifinterface:exifinterface:1.0.0'
+	implementation 'androidx.lifecycle:lifecycle-extensions:2.1.0'
+	implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
+	implementation 'com.google.android.material:material:1.1.0-beta01'
+	implementation 'androidx.recyclerview:recyclerview-selection:1.0.0'
 
-	implementation('ch.acra:acra:4.11') {
-		exclude module: 'support-v4'
-		exclude module: 'support-annotations'
-	}
-	implementation 'info.guardianproject.panic:panic:0.5'
+	implementation 'ch.acra:acra:4.11'
+	implementation 'info.guardianproject.panic:panic:1.0'
 	implementation 'info.guardianproject.trustedintents:trustedintents:0.2'
-	implementation 'de.hdodenhof:circleimageview:2.2.0'
-	implementation 'com.google.zxing:core:3.3.3'
-	implementation 'uk.co.samuelwall:material-tap-target-prompt:2.14.0'
-	implementation 'com.vanniktech:emoji-google:0.5.1'
-	implementation 'com.github.kobakei:MaterialFabSpeedDial:1.2.1' // later versions already use androidx
-	def glideVersion = '4.9.0'
+	implementation 'de.hdodenhof:circleimageview:3.0.1'
+	implementation 'com.google.zxing:core:3.3.3'  // newer version need minSdk 24
+	implementation 'uk.co.samuelwall:material-tap-target-prompt:3.0.0'
+	implementation 'com.vanniktech:emoji-google:0.6.0'
+	implementation 'com.github.kobakei:MaterialFabSpeedDial:1.2.1'
+	implementation 'com.github.chrisbanes:PhotoView:2.3.0'
+	def glideVersion = '4.10.0'
 	implementation("com.github.bumptech.glide:glide:$glideVersion") {
 		exclude group: 'com.android.support'
 		exclude module: 'disklrucache' // when there's no disk cache, we can't accidentally use it
 	}
-	implementation 'com.github.chrisbanes:PhotoView:2.1.4' // later versions already use androidx
 
-	annotationProcessor 'com.google.dagger:dagger-compiler:2.22.1'
+	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 	annotationProcessor "com.github.bumptech.glide:compiler:$glideVersion"
 
 	compileOnly 'javax.annotation:jsr250-api:1.0'
 
+	def espressoVersion = '3.2.0'
+	def jmockVersion = '2.8.2'
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
 	testImplementation project(path: ':bramble-core', configuration: 'testOutput')
-	testImplementation 'org.robolectric:robolectric:4.0.1'
-	testImplementation 'org.robolectric:shadows-support-v4:3.3.2'
-	testImplementation 'org.mockito:mockito-core:2.25.0'
+	testImplementation 'androidx.test:runner:1.2.0'
+	testImplementation 'androidx.test.ext:junit:1.1.1'
+	testImplementation 'androidx.fragment:fragment-testing:1.1.0'
+	testImplementation "androidx.test.espresso:espresso-core:$espressoVersion"
+	testImplementation 'org.robolectric:robolectric:4.3.1'
+	testImplementation 'org.mockito:mockito-core:3.1.0'
 	testImplementation 'junit:junit:4.12'
-	testImplementation "org.jmock:jmock:2.8.2"
-	testImplementation "org.jmock:jmock-junit4:2.8.2"
-	testImplementation "org.jmock:jmock-legacy:2.8.2"
+	testImplementation "org.jmock:jmock:$jmockVersion"
+	testImplementation "org.jmock:jmock-junit4:$jmockVersion"
+	testImplementation "org.jmock:jmock-legacy:$jmockVersion"
 
-	def espressoVersion = '3.0.2'
-	androidTestImplementation "com.android.support.test.espresso:espresso-core:$espressoVersion"
-	androidTestImplementation "com.android.support.test.espresso:espresso-contrib:$espressoVersion"
-	androidTestImplementation "com.android.support.test.espresso:espresso-intents:$espressoVersion"
-	androidTestAnnotationProcessor "com.google.dagger:dagger-compiler:2.22.1"
+	androidTestImplementation project(path: ':bramble-api', configuration: 'testOutput')
+	androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+	androidTestImplementation "androidx.test.espresso:espresso-core:$espressoVersion"
+	androidTestImplementation "androidx.test.espresso:espresso-contrib:$espressoVersion"
+	androidTestImplementation "androidx.test.espresso:espresso-intents:$espressoVersion"
+	androidTestAnnotationProcessor "com.google.dagger:dagger-compiler:2.24"
 	androidTestCompileOnly 'javax.annotation:jsr250-api:1.0'
 	androidTestImplementation 'junit:junit:4.12'
-	androidTestScreenshotImplementation "tools.fastlane:screengrab:1.2.0"
-	androidTestScreenshotImplementation "com.android.support.test.uiautomator:uiautomator-v18:2.1.3"
+	androidTestScreenshotImplementation('tools.fastlane:screengrab:1.2.0') {
+		// workaround for jetifier issue https://issuetracker.google.com/issues/123060356
+		exclude group: 'com.android.support.test.uiautomator'
+	}
+	androidTestScreenshotImplementation 'androidx.test.uiautomator:uiautomator:2.2.0'
 }
 
 task verifyTranslations {

briar-android/proguard-rules.txt

@@ -5,6 +5,10 @@
 
 # QR codes
 -keep class com.google.zxing.Result
+-keepclassmembers enum * {
+    public static **[] values();
+    public static ** valueOf(java.lang.String);
+}
 
 # RSS libraries
 -keep,includedescriptorclasses class com.rometools.rome.feed.synd.impl.** { *; }

briar-android/src/androidTest/java/org/briarproject/briar/android/BriarTestComponentApplication.java

@@ -1,8 +1,8 @@
 package org.briarproject.briar.android;
 
-import org.briarproject.bramble.BrambleAndroidModule;
-import org.briarproject.bramble.BrambleCoreModule;
-import org.briarproject.briar.BriarCoreModule;
+import org.briarproject.bramble.BrambleAndroidEagerSingletons;
+import org.briarproject.bramble.BrambleCoreEagerSingletons;
+import org.briarproject.briar.BriarCoreEagerSingletons;
 
 public class BriarTestComponentApplication extends BriarApplicationImpl {
 
@@ -12,10 +12,10 @@ public class BriarTestComponentApplication extends BriarApplicationImpl {
 				.appModule(new AppModule(this)).build();
 		// We need to load the eager singletons directly after making the
 		// dependency graphs
-		BrambleCoreModule.initEagerSingletons(component);
-		BrambleAndroidModule.initEagerSingletons(component);
-		BriarCoreModule.initEagerSingletons(component);
-		AndroidEagerSingletons.initEagerSingletons(component);
+		BrambleCoreEagerSingletons.Helper.injectEagerSingletons(component);
+		BrambleAndroidEagerSingletons.Helper.injectEagerSingletons(component);
+		BriarCoreEagerSingletons.Helper.injectEagerSingletons(component);
+		AndroidEagerSingletons.Helper.injectEagerSingletons(component);
 		return component;
 	}
 

briar-android/src/androidTest/java/org/briarproject/briar/android/BriarTestRunner.java

@@ -2,7 +2,8 @@ package org.briarproject.briar.android;
 
 import android.app.Application;
 import android.content.Context;
-import android.support.test.runner.AndroidJUnitRunner;
+
+import androidx.test.runner.AndroidJUnitRunner;
 
 public class BriarTestRunner extends AndroidJUnitRunner {
 

briar-android/src/androidTest/java/org/briarproject/briar/android/UiTest.java

@@ -2,7 +2,6 @@ package org.briarproject.briar.android;
 
 import android.app.Activity;
 import android.content.Intent;
-import android.support.test.espresso.intent.rule.IntentsTestRule;
 
 import org.briarproject.bramble.api.account.AccountManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
@@ -12,13 +11,16 @@ import org.briarproject.briar.R;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import static android.support.test.InstrumentationRegistry.getTargetContext;
+import androidx.test.espresso.intent.rule.IntentsTestRule;
+
+import static androidx.test.core.app.ApplicationProvider.getApplicationContext;
+
 
 @SuppressWarnings("WeakerAccess")
 public abstract class UiTest {
 
 	protected final String USERNAME =
-			getTargetContext().getString(R.string.screenshot_alice);
+			getApplicationContext().getString(R.string.screenshot_alice);
 	protected static final String PASSWORD = "123456";
 
 	@Inject
@@ -27,9 +29,7 @@ public abstract class UiTest {
 	protected LifecycleManager lifecycleManager;
 
 	public UiTest() {
-		BriarTestComponentApplication app =
-				(BriarTestComponentApplication) getTargetContext()
-						.getApplicationContext();
+		BriarTestComponentApplication app = getApplicationContext();
 		inject((BriarUiTestComponent) app.getApplicationComponent());
 	}
 
@@ -64,8 +64,8 @@ public abstract class UiTest {
 			accountManager.createAccount(USERNAME, PASSWORD);
 			if (runnable != null) {
 				Intent serviceIntent =
-						new Intent(getTargetContext(), BriarService.class);
-				getTargetContext().startService(serviceIntent);
+						new Intent(getApplicationContext(), BriarService.class);
+				getApplicationContext().startService(serviceIntent);
 				try {
 					lifecycleManager.waitForStartup();
 				} catch (InterruptedException e) {

briar-android/src/androidTest/java/org/briarproject/briar/android/ViewActions.java

@@ -1,21 +1,22 @@
 package org.briarproject.briar.android;
 
 import android.app.Activity;
-import android.support.test.espresso.PerformException;
-import android.support.test.espresso.UiController;
-import android.support.test.espresso.ViewAction;
-import android.support.test.runner.lifecycle.ActivityLifecycleMonitor;
-import android.support.test.runner.lifecycle.ActivityLifecycleMonitorRegistry;
-import android.support.test.runner.lifecycle.Stage;
 import android.view.View;
 
 import org.hamcrest.Matcher;
 
 import java.util.concurrent.TimeoutException;
 
-import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
-import static android.support.test.espresso.util.HumanReadables.describe;
-import static android.support.test.espresso.util.TreeIterables.breadthFirstViewTraversal;
+import androidx.test.espresso.PerformException;
+import androidx.test.espresso.UiController;
+import androidx.test.espresso.ViewAction;
+import androidx.test.runner.lifecycle.ActivityLifecycleMonitor;
+import androidx.test.runner.lifecycle.ActivityLifecycleMonitorRegistry;
+import androidx.test.runner.lifecycle.Stage;
+
+import static androidx.test.espresso.matcher.ViewMatchers.isDisplayed;
+import static androidx.test.espresso.util.HumanReadables.describe;
+import static androidx.test.espresso.util.TreeIterables.breadthFirstViewTraversal;
 import static java.lang.System.currentTimeMillis;
 import static java.util.concurrent.TimeUnit.SECONDS;
 

briar-android/src/androidTestOfficial/assets/PngSuite/PngSuite.LICENSE

@@ -0,0 +1,9 @@
+PngSuite
+--------
+
+Permission to use, copy, modify and distribute these images for any
+purpose and without fee is hereby granted.
+
+
+(c) Willem van Schaik, 1996, 2011
+

briar-android/src/androidTestOfficial/assets/PngSuite/PngSuite.README

@@ -0,0 +1,25 @@
+        PNGSUITE
+----------------
+
+        testset for PNG-(de)coders
+        created by Willem van Schaik
+------------------------------------
+
+This is a collection of graphics images created to test the png applications
+like viewers, converters and editors. All (as far as that is possible)
+formats supported by the PNG standard are represented.
+
+The suite consists of the following files:
+
+-	PngSuite.README		- this file
+-	PngSuite.LICENSE	- the PngSuite is freeware
+-	PngSuite.png		- image with PngSuite logo
+-	PngSuite.tgz		- archive of all PNG testfiles
+-	PngSuite.zip		- same in .zip format for PCs
+
+
+--------
+    (c) Willem van Schaik
+	willem@schaik.com
+        Calgary, April 2011
+