Add migration that drops offers table.

.gitlab-ci.yml

@@ -2,7 +2,6 @@ image: briar/ci-image-android:latest
 
 stages:
 - test
-- optional_tests
 - check_reproducibility
 
 test:
@@ -32,33 +31,3 @@ test_reproducible:
     - "curl -X POST -F token=${RELEASE_CHECK_TOKEN} -F ref=master -F variables[RELEASE_TAG]=${CI_COMMIT_REF_NAME} https://code.briarproject.org/api/v4/projects/61/trigger/pipeline"
   only:
     - tags
-
-.optional_tests:
-  stage: optional_tests
-  before_script:
-    - set -e
-    - export GRADLE_USER_HOME=$PWD/.gradle
-
-  cache:
-    paths:
-      - .gradle/wrapper
-      - .gradle/caches
-
-  script:
-    - OPTIONAL_TESTS=org.briarproject.bramble.plugin.tor.BridgeTest ./gradlew --info bramble-java:test --tests BridgeTest
-
-  after_script:
-    # these file change every time but should not be cached
-    - rm -f $GRADLE_USER_HOME/caches/modules-2/modules-2.lock
-    - rm -fr $GRADLE_USER_HOME/caches/*/plugin-resolution/
-
-manual_tests:
-  extends: .optional_tests
-  when: manual
-  except:
-    - tags
-
-pre_release_tests:
-  extends: .optional_tests
-  only:
-    - tags

.idea/dictionaries/briar.xml

@@ -1,14 +0,0 @@
-<component name="ProjectDictionaryState">
-  <dictionary name="briar">
-    <words>
-      <w>briar</w>
-      <w>briarproject</w>
-      <w>emoji</w>
-      <w>encrypter</w>
-      <w>identicon</w>
-      <w>introducee</w>
-      <w>introducer</w>
-      <w>onboarding</w>
-    </words>
-  </dictionary>
-</component>

.idea/runConfigurations/All_tests.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.briar-android" />
+    <module name="briar-android" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
@@ -13,7 +13,6 @@
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-core" run_configuration_type="AndroidJUnit" />
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-android" run_configuration_type="AndroidJUnit" />
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in bramble-java" run_configuration_type="AndroidJUnit" />
-      <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in briar-api" run_configuration_type="AndroidJUnit" />
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in briar-core" run_configuration_type="AndroidJUnit" />
       <option name="RunConfigurationTask" enabled="true" run_configuration_name="All tests in briar-headless" run_configuration_type="AndroidJUnit" />
     </method>

.idea/runConfigurations/All_tests_in_bramble_android.xml

@@ -1,14 +1,20 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in bramble-android" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.bramble-android" />
+    <module name="bramble-android" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-android" />
-    <method v="2">
+    <option name="PASS_PARENT_ENVS" value="true" />
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    <option name="TEST_SEARCH_SCOPE">
-    </method>
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_bramble_api.xml

@@ -1,14 +1,20 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in bramble-api" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.bramble-api" />
+    <module name="bramble-api" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-api" />
-    <method v="2">
+    <option name="PASS_PARENT_ENVS" value="true" />
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    <option name="TEST_SEARCH_SCOPE">
-    </method>
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_bramble_core.xml

@@ -1,14 +1,20 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in bramble-core" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.bramble-core" />
+    <module name="bramble-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-core" />
-    <method v="2">
+    <option name="PASS_PARENT_ENVS" value="true" />
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    <option name="TEST_SEARCH_SCOPE">
-    </method>
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_bramble_java.xml

@@ -1,6 +1,8 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in bramble-java" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.bramble-java" />
+    <module name="bramble-java" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
@@ -8,8 +10,11 @@
     <option name="VM_PARAMETERS" value="-ea -Djava.library.path=libs" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/bramble-java" />
-    <method v="2">
+    <option name="PASS_PARENT_ENVS" value="true" />
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    <option name="TEST_SEARCH_SCOPE">
-    </method>
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_briar_android.xml

@@ -1,14 +1,20 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in briar-android" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.briar-android" />
+    <module name="briar-android" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-android" />
-    <method v="2">
+    <option name="PASS_PARENT_ENVS" value="true" />
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    <option name="TEST_SEARCH_SCOPE">
-    </method>
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_briar_api.xml

@@ -1,14 +0,0 @@
-<component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="All tests in briar-api" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.briar-api" />
-    <option name="PACKAGE_NAME" value="" />
-    <option name="MAIN_CLASS_NAME" value="" />
-    <option name="METHOD_NAME" value="" />
-    <option name="TEST_OBJECT" value="package" />
-    <option name="PARAMETERS" value="" />
-    <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-api" />
-    <method v="2">
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-    </method>
-  </configuration>
-</component>

.idea/runConfigurations/All_tests_in_briar_core.xml

@@ -1,14 +1,20 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in briar-core" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.briar-core" />
+    <module name="briar-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="package" />
+    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="file://$PROJECT_DIR$/briar-core" />
-    <method v="2">
+    <option name="PASS_PARENT_ENVS" value="true" />
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    <option name="TEST_SEARCH_SCOPE">
-    </method>
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
   </configuration>
 </component>

.idea/runConfigurations/All_tests_in_briar_headless.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="All tests in briar-headless" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.briar-headless" />
+    <module name="briar-headless" />
     <option name="PACKAGE_NAME" value="org.briarproject.briar.headless" />
     <option name="MAIN_CLASS_NAME" value="" />
     <option name="METHOD_NAME" value="" />

.idea/runConfigurations/BridgeTest.xml

@@ -1,24 +0,0 @@
-<component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="BridgeTest" type="AndroidJUnit" factoryName="Android JUnit" nameIsGenerated="true">
-    <module name="briar.bramble-java" />
-    <useClassPathOnly />
-    <extension name="coverage">
-      <pattern>
-        <option name="PATTERN" value="org.briarproject.bramble.plugin.tor.*" />
-        <option name="ENABLED" value="true" />
-      </pattern>
-    </extension>
-    <option name="PACKAGE_NAME" value="org.briarproject.bramble.plugin.tor" />
-    <option name="MAIN_CLASS_NAME" value="org.briarproject.bramble.plugin.tor.BridgeTest" />
-    <option name="METHOD_NAME" value="" />
-    <option name="TEST_OBJECT" value="class" />
-    <option name="PARAMETERS" value="" />
-    <option name="WORKING_DIRECTORY" value="$MODULE_DIR$" />
-    <envs>
-      <env name="OPTIONAL_TESTS" value="org.briarproject.bramble.plugin.tor.BridgeTest" />
-    </envs>
-    <method v="2">
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
-    </method>
-  </configuration>
-</component>

.idea/runConfigurations/H2_Performance_Test.xml

@@ -1,14 +1,20 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="H2 Performance Test" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.bramble-core" />
+    <module name="bramble-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="org.briarproject.bramble.db" />
     <option name="MAIN_CLASS_NAME" value="org.briarproject.bramble.db.H2DatabasePerformanceTest" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="class" />
+    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="" />
-    <method v="2">
+    <option name="PASS_PARENT_ENVS" value="true" />
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    <option name="TEST_SEARCH_SCOPE">
-    </method>
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
   </configuration>
 </component>

.idea/runConfigurations/HyperSQL_Performance_Test.xml

@@ -1,14 +1,20 @@
 <component name="ProjectRunConfigurationManager">
   <configuration default="false" name="HyperSQL Performance Test" type="AndroidJUnit" factoryName="Android JUnit">
-    <module name="briar.bramble-core" />
+    <module name="bramble-core" />
+    <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
+    <option name="ALTERNATIVE_JRE_PATH" />
     <option name="PACKAGE_NAME" value="org.briarproject.bramble.db" />
     <option name="MAIN_CLASS_NAME" value="org.briarproject.bramble.db.HyperSqlDatabasePerformanceTest" />
     <option name="METHOD_NAME" value="" />
     <option name="TEST_OBJECT" value="class" />
+    <option name="VM_PARAMETERS" value="-ea" />
     <option name="PARAMETERS" value="" />
     <option name="WORKING_DIRECTORY" value="" />
-    <method v="2">
+    <option name="PASS_PARENT_ENVS" value="true" />
-      <option name="Android.Gradle.BeforeRunTask" enabled="true" />
+    <option name="TEST_SEARCH_SCOPE">
-    </method>
+      <value defaultName="singleModule" />
+    </option>
+    <patterns />
+    <method />
   </configuration>
 </component>

.idea/runConfigurations/briar_headless.xml

@@ -1,6 +1,6 @@
 <component name="ProjectRunConfigurationManager">
-  <configuration default="false" name="briar-headless" type="JetRunConfigurationType" singleton="true">
+  <configuration default="false" name="briar-headless" type="JetRunConfigurationType" factoryName="Kotlin" singleton="true">
-    <module name="briar.briar-headless" />
+    <extension name="coverage" enabled="false" merge="false" sample_coverage="true" runner="idea" />
     <option name="VM_PARAMETERS" value="" />
     <option name="PROGRAM_PARAMETERS" value="-v" />
     <option name="ALTERNATIVE_JRE_PATH_ENABLED" value="false" />
@@ -8,8 +8,9 @@
     <option name="PASS_PARENT_ENVS" value="true" />
     <option name="MAIN_CLASS_NAME" value="org.briarproject.briar.headless.MainKt" />
     <option name="WORKING_DIRECTORY" value="" />
-    <method v="2">
+    <module name="briar-headless" />
-      <option name="Make" enabled="true" />
+    <envs />
+    <method>
       <option name="Gradle.BeforeRunTask" enabled="true" tasks="jar" externalProjectPath="$PROJECT_DIR$/briar-headless" vmOptions="" scriptParameters="" />
     </method>
   </configuration>

bramble-android/build.gradle

@@ -5,18 +5,14 @@ apply plugin: 'witness'
 apply from: 'witness.gradle'
 
 android {
-	compileSdkVersion 30
+	compileSdkVersion rootProject.ext.compileSdkVersion
-	buildToolsVersion '30.0.2'
+	buildToolsVersion rootProject.ext.buildToolsVersion
-
-	packagingOptions {
-		doNotStrip '**/*.so'
-	}
 
 	defaultConfig {
-		minSdkVersion 16
+		minSdkVersion rootProject.ext.minSdkVersion
-		targetSdkVersion 29
+		targetSdkVersion rootProject.ext.targetSdkVersion
-		versionCode 10218
+		versionCode rootProject.ext.versionCode
-		versionName "1.2.18"
+		versionName rootProject.ext.versionName
 		consumerProguardFiles 'proguard-rules.txt'
 
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -42,18 +38,18 @@ configurations {
 
 dependencies {
 	implementation project(path: ':bramble-core', configuration: 'default')
-	tor 'org.briarproject:tor-android:0.3.5.13@zip'
+	tor 'org.briarproject:tor-android:0.3.5.10@zip'
-	tor 'org.briarproject:obfs4proxy-android:0.0.12-dev-40245c4a@zip'
+	tor 'org.briarproject:obfs4proxy-android:0.0.11-2@zip'
 
 	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 
 	compileOnly 'javax.annotation:jsr250-api:1.0'
 
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
-	testImplementation "junit:junit:$junit_version"
+	testImplementation 'junit:junit:4.12'
-	testImplementation "org.jmock:jmock:$jmock_version"
+	testImplementation "org.jmock:jmock:2.8.2"
-	testImplementation "org.jmock:jmock-junit4:$jmock_version"
+	testImplementation "org.jmock:jmock-junit4:2.8.2"
-	testImplementation "org.jmock:jmock-imposters:$jmock_version"
+	testImplementation "org.jmock:jmock-legacy:2.8.2"
 }
 
 def torBinariesDir = 'src/main/res/raw'

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

@@ -1,15 +1,11 @@
 package org.briarproject.bramble.network;
 
-import android.annotation.TargetApi;
 import android.app.Application;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.ConnectivityManager;
-import android.net.LinkAddress;
-import android.net.LinkProperties;
-import android.net.Network;
 import android.net.NetworkInfo;
 
 import org.briarproject.bramble.api.event.EventBus;
@@ -23,11 +19,6 @@ import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.system.TaskScheduler;
 import org.briarproject.bramble.api.system.TaskScheduler.Cancellable;
 
-import java.net.Inet4Address;
-import java.net.InetAddress;
-import java.net.NetworkInterface;
-import java.net.SocketException;
-import java.util.Enumeration;
 import java.util.concurrent.Executor;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -45,22 +36,16 @@ import static android.net.ConnectivityManager.TYPE_WIFI;
 import static android.net.wifi.p2p.WifiP2pManager.WIFI_P2P_THIS_DEVICE_CHANGED_ACTION;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.os.PowerManager.ACTION_DEVICE_IDLE_MODE_CHANGED;
-import static java.net.NetworkInterface.getNetworkInterfaces;
-import static java.util.Collections.list;
 import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.concurrent.TimeUnit.SECONDS;
 import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
-import static org.briarproject.bramble.util.LogUtils.logException;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 class AndroidNetworkManager implements NetworkManager, Service {
 
 	private static final Logger LOG =
-			getLogger(AndroidNetworkManager.class.getName());
+			Logger.getLogger(AndroidNetworkManager.class.getName());
 
 	// See android.net.wifi.WifiManager
 	private static final String WIFI_AP_STATE_CHANGED_ACTION =
@@ -69,8 +54,7 @@ class AndroidNetworkManager implements NetworkManager, Service {
 	private final TaskScheduler scheduler;
 	private final EventBus eventBus;
 	private final Executor eventExecutor;
-	private final Application app;
+	private final Context appContext;
-	private final ConnectivityManager connectivityManager;
 	private final AtomicReference<Cancellable> connectivityCheck =
 			new AtomicReference<>();
 	private final AtomicBoolean used = new AtomicBoolean(false);
@@ -83,9 +67,7 @@ class AndroidNetworkManager implements NetworkManager, Service {
 		this.scheduler = scheduler;
 		this.eventBus = eventBus;
 		this.eventExecutor = eventExecutor;
-		this.app = app;
+		this.appContext = app.getApplicationContext();
-		connectivityManager = (ConnectivityManager)
-				requireNonNull(app.getSystemService(CONNECTIVITY_SERVICE));
 	}
 
 	@Override
@@ -100,82 +82,24 @@ class AndroidNetworkManager implements NetworkManager, Service {
 		filter.addAction(WIFI_AP_STATE_CHANGED_ACTION);
 		filter.addAction(WIFI_P2P_THIS_DEVICE_CHANGED_ACTION);
 		if (SDK_INT >= 23) filter.addAction(ACTION_DEVICE_IDLE_MODE_CHANGED);
-		app.registerReceiver(networkStateReceiver, filter);
+		appContext.registerReceiver(networkStateReceiver, filter);
 	}
 
 	@Override
 	public void stopService() {
 		if (networkStateReceiver != null)
-			app.unregisterReceiver(networkStateReceiver);
+			appContext.unregisterReceiver(networkStateReceiver);
 	}
 
 	@Override
 	public NetworkStatus getNetworkStatus() {
-		NetworkInfo net = connectivityManager.getActiveNetworkInfo();
+		ConnectivityManager cm = (ConnectivityManager)
+				appContext.getSystemService(CONNECTIVITY_SERVICE);
+		if (cm == null) throw new AssertionError();
+		NetworkInfo net = cm.getActiveNetworkInfo();
 		boolean connected = net != null && net.isConnected();
-		boolean wifi = false, ipv6Only = false;
+		boolean wifi = connected && net.getType() == TYPE_WIFI;
-		if (connected) {
+		return new NetworkStatus(connected, wifi);
-			wifi = net.getType() == TYPE_WIFI;
-			if (SDK_INT >= 23) ipv6Only = isActiveNetworkIpv6Only();
-			else ipv6Only = areAllAvailableNetworksIpv6Only();
-		}
-		return new NetworkStatus(connected, wifi, ipv6Only);
-	}
-
-	/**
-	 * Returns true if the
-	 * {@link ConnectivityManager#getActiveNetwork() active network} has an
-	 * IPv6 unicast address and no IPv4 addresses. The active network is
-	 * assumed not to be a loopback interface.
-	 */
-	@TargetApi(23)
-	private boolean isActiveNetworkIpv6Only() {
-		Network net = connectivityManager.getActiveNetwork();
-		if (net == null) {
-			LOG.info("No active network");
-			return false;
-		}
-		LinkProperties props = connectivityManager.getLinkProperties(net);
-		if (props == null) {
-			LOG.info("No link properties for active network");
-			return false;
-		}
-		boolean hasIpv6Unicast = false;
-		for (LinkAddress linkAddress : props.getLinkAddresses()) {
-			InetAddress addr = linkAddress.getAddress();
-			if (addr instanceof Inet4Address) return false;
-			if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
-		}
-		return hasIpv6Unicast;
-	}
-
-	/**
-	 * Returns true if the device has at least one network interface with an
-	 * IPv6 unicast address and no interfaces with IPv4 addresses, excluding
-	 * loopback interfaces and interfaces that are
-	 * {@link NetworkInterface#isUp() down}. If this method returns true and
-	 * the device has internet access then it's via IPv6 only.
-	 */
-	private boolean areAllAvailableNetworksIpv6Only() {
-		try {
-			Enumeration<NetworkInterface> interfaces = getNetworkInterfaces();
-			if (interfaces == null) {
-				LOG.info("No network interfaces");
-				return false;
-			}
-			boolean hasIpv6Unicast = false;
-			for (NetworkInterface i : list(interfaces)) {
-				if (i.isLoopback() || !i.isUp()) continue;
-				for (InetAddress addr : list(i.getInetAddresses())) {
-					if (addr instanceof Inet4Address) return false;
-					if (!addr.isMulticastAddress()) hasIpv6Unicast = true;
-				}
-			}
-			return hasIpv6Unicast;
-		} catch (SocketException e) {
-			logException(LOG, WARNING, e);
-			return false;
-		}
 	}
 
 	private void updateConnectionStatus() {

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

@@ -175,11 +175,6 @@ class AndroidBluetoothPlugin
 		} catch (IOException e) {
 			IoUtils.tryToClose(s, LOG, WARNING);
 			throw e;
-		} catch (NullPointerException e) {
-			// BluetoothSocket#connect() may throw an NPE under unknown
-			// circumstances
-			IoUtils.tryToClose(s, LOG, WARNING);
-			throw new IOException(e);
 		}
 	}
 

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

@@ -6,6 +6,8 @@ import android.bluetooth.BluetoothAdapter;
 import android.bluetooth.BluetoothDevice;
 import android.content.ContentResolver;
 import android.content.Context;
+import android.net.wifi.WifiConfiguration;
+import android.net.wifi.WifiManager;
 import android.os.Build;
 import android.os.Parcel;
 import android.os.StrictMode;
@@ -15,10 +17,12 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.io.DataOutputStream;
 import java.io.IOException;
+import java.util.List;
 
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
+import static android.content.Context.WIFI_SERVICE;
 import static android.os.Build.VERSION.SDK_INT;
 import static android.provider.Settings.Secure.ANDROID_ID;
 
@@ -48,6 +52,15 @@ class AndroidSecureRandomProvider extends UnixSecureRandomProvider {
 		String id = Settings.Secure.getString(contentResolver, ANDROID_ID);
 		if (id != null) out.writeUTF(id);
 		Parcel parcel = Parcel.obtain();
+		WifiManager wm = (WifiManager) appContext.getApplicationContext()
+				.getSystemService(WIFI_SERVICE);
+		if (wm != null) {
+			List<WifiConfiguration> configs = wm.getConfiguredNetworks();
+			if (configs != null) {
+				for (WifiConfiguration config : configs)
+					parcel.writeParcelable(config, 0);
+			}
+		}
 		BluetoothAdapter bt = BluetoothAdapter.getDefaultAdapter();
 		if (bt != null) {
 			for (BluetoothDevice device : bt.getBondedDevices())

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

@@ -2,6 +2,7 @@ package org.briarproject.bramble.system;
 
 import android.app.Application;
 import android.content.Context;
+import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.os.PowerManager;
 
@@ -105,21 +106,14 @@ class AndroidWakeLockManagerImpl implements AndroidWakeLockManager {
 
 	private String getWakeLockTag(Context ctx) {
 		PackageManager pm = ctx.getPackageManager();
-		if (isInstalled(pm, "com.huawei.powergenie")) {
+		for (PackageInfo info : pm.getInstalledPackages(0)) {
-			return "LocationManagerService";
+			String name = info.packageName.toLowerCase();
-		} else if (isInstalled(pm, "com.evenwell.PowerMonitor")) {
+			if (name.startsWith("com.huawei.powergenie")) {
-			return "AudioIn";
+				return "LocationManagerService";
+			} else if (name.startsWith("com.evenwell.powermonitor")) {
+				return "AudioIn";
+			}
 		}
 		return ctx.getPackageName();
 	}
-
-	private boolean isInstalled(PackageManager pm, String packageName) {
-		try {
-			pm.getPackageInfo(packageName, 0);
-			return true;
-		} catch (PackageManager.NameNotFoundException e) {
-			return false;
-		}
-	}
-
 }

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

@@ -31,7 +31,6 @@ public class AndroidUtils {
 	private static final String FAKE_BLUETOOTH_ADDRESS = "02:00:00:00:00:00";
 
 	private static final String STORED_REPORTS = "dev-reports";
-	private static final String STORED_LOGCAT = "dev-logcat";
 
 	public static Collection<String> getSupportedArchitectures() {
 		List<String> abis = new ArrayList<>();
@@ -108,14 +107,14 @@ public class AndroidUtils {
 		return ctx.getDir(STORED_REPORTS, MODE_PRIVATE);
 	}
 
-	public static File getLogcatFile(Context ctx) {
-		return new File(ctx.getFilesDir(), STORED_LOGCAT);
-	}
-
 	/**
 	 * 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() {
-		return new String[] {"image/jpeg", "image/png", "image/gif"};
+		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

@@ -9,7 +9,7 @@ import org.briarproject.bramble.api.db.DatabaseConfig;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.jmock.Expectations;
-import org.jmock.imposters.ByteBuddyClassImposteriser;
+import org.jmock.lib.legacy.ClassImposteriser;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -44,7 +44,7 @@ public class AndroidAccountManagerTest extends BrambleMockTestCase {
 	private AndroidAccountManager accountManager;
 
 	public AndroidAccountManagerTest() {
-		context.setImposteriser(ByteBuddyClassImposteriser.INSTANCE);
+		context.setImposteriser(ClassImposteriser.INSTANCE);
 		app = context.mock(Application.class);
 		applicationInfo = new ApplicationInfo();
 		applicationInfo.dataDir = testDir.getAbsolutePath();

bramble-android/witness.gradle

@@ -1,117 +1,103 @@
 dependencyVerification {
     verify = [
-        'cglib:cglib:3.2.8:cglib-3.2.8.jar:3f64de999ecc5595dc84ca8ff0879d8a34c8623f9ef3c517a53ed59023fcb9db',
+        'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
-        'com.android.tools.analytics-library:protos:27.2.2:protos-27.2.2.jar:02482564443c294dfe87c5f2b25387f724a698a09ed58e0cf0127400caa35a19',
+        'com.android.tools.analytics-library:protos:26.5.1:protos-26.5.1.jar:8dde1130725461fe827f2a343d353f2b51e8870661fc860d7d5ebddb097ead4e',
-        'com.android.tools.analytics-library:shared:27.2.2:shared-27.2.2.jar:0efe017ca17ee775c5af386475a09799a1282faa04821d54810c1a34f6348d9c',
+        'com.android.tools.analytics-library:shared:26.5.1:shared-26.5.1.jar:ccc2f3b00ec17b11401610ba68553544fc8fc517120e84439ac6eb86b875e18d',
-        'com.android.tools.analytics-library:tracker:27.2.2:tracker-27.2.2.jar:62489d84192dc06219664945c43201654ff85c3b715f46550751512a880d0e39',
+        'com.android.tools.analytics-library:tracker:26.5.1:tracker-26.5.1.jar:3a76984c0fe2e847ca7a8b35b4780ef0447a9d1666946cb8e60466318e0ab5ae',
-        'com.android.tools.build:aapt2-proto:4.1.0-alpha01-6193524:aapt2-proto-4.1.0-alpha01-6193524.jar:17e75523e1e92dd4f222c7368ee41df9e964a508232f591e265d0c499baf9dca',
+        'com.android.tools.build:aapt2-proto:0.4.0:aapt2-proto-0.4.0.jar:fac0435e08898f89eeeb9ca236bea707155ff816c12205ced285ad53604133ca',
-        'com.android.tools.build:apksig:4.2.2:apksig-4.2.2.jar:632690bf641b429dcb31650e6b2f6a2e87c4ac8afd45a6ba3cbc99fb1612178f',
+        'com.android.tools.build:apksig:3.5.1:apksig-3.5.1.jar:1fd33e7f009a2a0da766cfeec4211a09f548034b015c289a66d75dd8a9302f4a',
-        'com.android.tools.build:apkzlib:4.2.2:apkzlib-4.2.2.jar:3b5167c1265e97f65201c4d2be6a6f72165a3aa2fe9e0594a59b67af9e9e97b9',
+        'com.android.tools.build:apkzlib:3.5.1:apkzlib-3.5.1.jar:9f330167cbe973b7db407692f74f4f6453b7ffa5f2048934b06280c2ceee60fa',
-        'com.android.tools.build:builder-model:4.2.2:builder-model-4.2.2.jar:41868de0cb88ae70b828eee4191c13e0233f433abb1becdf6a2bd391bd446bc0',
+        'com.android.tools.build:builder-model:3.5.1:builder-model-3.5.1.jar:39ea3c82b76b6e0c9f9fa88d93e0edc1dd4a0f1dfae0ef6fbf2d451da47e5450',
-        'com.android.tools.build:builder-test-api:4.2.2:builder-test-api-4.2.2.jar:2f305c6d3a7b637d736b821bad372dcabd959e979f2065a9f65bac1e7b4d1875',
+        'com.android.tools.build:builder-test-api:3.5.1:builder-test-api-3.5.1.jar:a1b59305584cbcaa078fdc9cfb80871012755b822dd32e8da19add6f7bbcb762',
-        'com.android.tools.build:builder:4.2.2:builder-4.2.2.jar:40fedd0d16db8f34ddb4eaf812d966b90ef1764f65cf119030442823bcf995cd',
+        'com.android.tools.build:builder:3.5.1:builder-3.5.1.jar:e3a8d382434c5f60990730c4719fc814e85a898a33a1e96c1df8d627d3c6eea6',
-        'com.android.tools.build:gradle-api:4.2.2:gradle-api-4.2.2.jar:dd4ef35bbbfb8fc2d20e3311c76b516bc1672e82b61cb3a59fc877da0f9b4f61',
+        'com.android.tools.build:gradle-api:3.5.1:gradle-api-3.5.1.jar:be9b41859bace11998f66b04ed944f87e413f3ad6da3c4665587699da125addc',
-        'com.android.tools.build:manifest-merger:27.2.2:manifest-merger-27.2.2.jar:971974756f32d9e94c857d92772b1499b0b0f5d9c70cb8ebbd20d9bbf804a923',
+        'com.android.tools.build:manifest-merger:26.5.1:manifest-merger-26.5.1.jar:dcad9ecb967251f4d750f55a4204a2b400e8fbfe5cb930a1d0d5dbe10ae8bdfc',
-        'com.android.tools.ddms:ddmlib:27.2.2:ddmlib-27.2.2.jar:9ab0f9b58737c316af454184705854c75936ca3531f21acc29bd68a3343334d1',
+        'com.android.tools.ddms:ddmlib:26.5.1:ddmlib-26.5.1.jar:b081aef2a4ed3f4d47cae4cdb128469735f25a114e026d37123bf9ffdec742a8',
-        'com.android.tools.external.com-intellij:intellij-core:27.2.2:intellij-core-27.2.2.jar:01619d5dc28ec909cbdee699f1f13056e84462faf6dccf4817561293fb28bef0',
+        '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:27.2.2:kotlin-compiler-27.2.2.jar:71bd460199ce7293ecc54b91a115319c1e4b585eca5a5b3699f6a406f29e626c',
+        '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:27.2.2:uast-27.2.2.jar:efa59302fd433015e993143530cecb456b63d10d0b89bd1d3b1a016904338a65',
+        'com.android.tools.external.org-jetbrains:uast:26.5.1:uast-26.5.1.jar:4bc8653d6c0943f40fee963a149e36c6baa45683d2530968a13f5007e3c40740',
-        'com.android.tools.layoutlib:layoutlib-api:27.2.2:layoutlib-api-27.2.2.jar:f0901f2295d814e82ad95850ea2103dd89d8489e01727fafa55ccccc0dccd163',
+        'com.android.tools.layoutlib:layoutlib-api:26.5.1:layoutlib-api-26.5.1.jar:88732f11396c427273e515d23042e35633f4fe4295528a99b866aa2adf0efd9c',
-        'com.android.tools.lint:lint-api:27.2.2:lint-api-27.2.2.jar:1ecb5959c8e624ee49cdf9178de67bb0e823b4382ed253410eb36afe5c458b05',
+        'com.android.tools.lint:lint-api:26.5.1:lint-api-26.5.1.jar:ec33fcd72bfaf70dd841e03fbfd93f109c2e575aec146067c606689c3972f0de',
-        'com.android.tools.lint:lint-checks:27.2.2:lint-checks-27.2.2.jar:989e545a6b5e398e63a9f3608da02d6111f2241faec1baa0a3b4492cb03aeaf2',
+        'com.android.tools.lint:lint-checks:26.5.1:lint-checks-26.5.1.jar:a1b9607d484aaae7a71dcecdc76f8003d8239af226c776894a2cf63f9e6c60d7',
-        'com.android.tools.lint:lint-gradle-api:27.2.2:lint-gradle-api-27.2.2.jar:2be9c69d6fbbfb012ff6521fdfcb22eb7cfaa57d108e07bb1d4143dae9c1b433',
+        'com.android.tools.lint:lint-gradle-api:26.5.1:lint-gradle-api-26.5.1.jar:82453fd98a8394cc84ed995c04d2cd744abd1d6589403427ba7eef53115406f3',
-        'com.android.tools.lint:lint-gradle:27.2.2:lint-gradle-27.2.2.jar:742dedd5ccb459a245a35bf4fa16dfecc762da1a6b1741332cfe5228e812301a',
+        'com.android.tools.lint:lint-gradle:26.5.1:lint-gradle-26.5.1.jar:59465b56cf7db77c656d5f8195d721c3d48b6bdd0502d774de335bfe4baff00b',
-        'com.android.tools.lint:lint-model:27.2.2:lint-model-27.2.2.jar:ee31012586462bea2d591b6175934e5f29b6f781a78fda50f79387972364b9ab',
+        'com.android.tools.lint:lint:26.5.1:lint-26.5.1.jar:336e4b04ec6f8b0f25879131b7a7862d77df83a1879ee5b71be26128755f8e2e',
-        'com.android.tools.lint:lint:27.2.2:lint-27.2.2.jar:7247016af7fba8cabee6ae887515b144f5a2ff7823422654daf23be9202f8fb1',
+        'com.android.tools:annotations:26.5.1:annotations-26.5.1.jar:2c43c82f8c59d8f7a61e3239e1a2dc9f69dc342ec09af9b7c9f69b25337c0b6e',
-        'com.android.tools:annotations:27.2.2:annotations-27.2.2.jar:9375fb2df5c0cf1b46fef9e65b3a27ac88925ccf90054b19ae0ca0adc7036fe1',
+        'com.android.tools:common:26.5.1:common-26.5.1.jar:eccfa54486ed54c4e3123cc42195d023bd0dd21bcd2f0e4868e8c6fc70f8ef6b',
-        'com.android.tools:common:27.2.2:common-27.2.2.jar:a76f4e10cad39bed317be031fee915d280aa8bc11616c58ab94e051b1e38769d',
+        'com.android.tools:dvlib:26.5.1:dvlib-26.5.1.jar:46f93ad498b4756e7d867d2fe38c38890a80e7407a4ae459e4a8c8d5c5aeacfe',
-        'com.android.tools:dvlib:27.2.2:dvlib-27.2.2.jar:9931c6b57460b5f8cc2613ca5ff8596aa089a67655ace13d173f90538ecb4301',
+        'com.android.tools:repository:26.5.1:repository-26.5.1.jar:2b3ee791aa4c3e8ce60498c161a27ca7228816fc630eed4d9f25f2f36a106dce',
-        'com.android.tools:repository:27.2.2:repository-27.2.2.jar:ac5f9b19dc5d9d08e80b57da76059f5760ca76c221e40ffd4bf43d7b13991674',
+        'com.android.tools:sdk-common:26.5.1:sdk-common-26.5.1.jar:365f749676c3574676fd465177c8a492f340816db2b520d6ed114d3b6e77bea7',
-        'com.android.tools:sdk-common:27.2.2:sdk-common-27.2.2.jar:b147acc13850808d61fc391ccfeeebdf90841b461a7042acb2d92e466da8e674',
+        'com.android.tools:sdklib:26.5.1:sdklib-26.5.1.jar:007da104afb27c8c682a1628023fe9ec438249c8d15ef0fd6624c5bb8e23b696',
-        'com.android.tools:sdklib:27.2.2:sdklib-27.2.2.jar:fae0bafbe8b4f546cf64986a22b7d8ed108d45519366ff22f0170a9cf3ea7f34',
-        'com.android:signflinger:4.2.2:signflinger-4.2.2.jar:4d7aafd9666707b483b1ad2c466824287cf2e379dda1d204dd3b7e453ffcf760',
-        'com.android:zipflinger:4.2.2:zipflinger-4.2.2.jar:8e4677086c9a8f4a67374a4edc31db7e481f0d9b85907263c51ca72452c23a93',
-        'com.google.code.findbugs:annotations:3.0.1:annotations-3.0.1.jar:6b47ff0a6de0ce17cbedc3abb0828ca5bce3009d53ea47b3723ff023c4742f79',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
-        'com.google.code.gson:gson:2.8.6:gson-2.8.6.jar:c8fb4839054d280b3033f800d1f5a97de2f028eb8ba2eb458ad287e536f3f25f',
+        '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:error_prone_annotations:2.3.2:error_prone_annotations-2.3.2.jar:357cd6cfb067c969226c442451502aee13800a24e950fdfde77bcdb4565a668d',
         '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: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:guava:28.1-jre:guava-28.1-jre.jar:30beb8b8527bd07c6e747e77f1a92122c2f29d57ce347461a4a55eb26e382da4',
         '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.j2objc:j2objc-annotations:1.3:j2objc-annotations-1.3.jar:21af30c92267bd6122c0e0b4d20cccb6641a37eaf956c6540ec471d584e64a7b',
         'com.google.jimfs:jimfs:1.1:jimfs-1.1.jar:c4828e28d7c0a930af9387510b3bada7daa5c04d7c25a75c7b8b081f1c257ddd',
-        'com.google.protobuf:protobuf-java:3.10.0:protobuf-java-3.10.0.jar:161d7d61a8cb3970891c299578702fd079646e032329d6c2cabf998d191437c9',
+        'com.google.protobuf:protobuf-java:3.4.0:protobuf-java-3.4.0.jar:dce7e66b32456a1b1198da0caff3a8acb71548658391e798c79369241e6490a4',
         'com.googlecode.json-simple:json-simple:1.1:json-simple-1.1.jar:2d9484f4c649f708f47f9a479465fc729770ee65617dca3011836602264f6439',
         'com.squareup:javapoet:1.11.1:javapoet-1.11.1.jar:9cbf2107be499ec6e95afd36b58e3ca122a24166cdd375732e51267d64058e90',
         'com.squareup:javawriter:2.5.0:javawriter-2.5.0.jar:fcfb09fb0ea0aa97d3cfe7ea792398081348e468f126b3603cb3803f240197f0',
         'com.sun.activation:javax.activation:1.2.0:javax.activation-1.2.0.jar:993302b16cd7056f21e779cc577d175a810bb4900ef73cd8fbf2b50f928ba9ce',
-        'com.sun.istack:istack-commons-runtime:3.0.8:istack-commons-runtime-3.0.8.jar:4ffabb06be454a05e4398e20c77fa2b6308d4b88dfbef7ca30a76b5b7d5505ef',
+        'com.sun.istack:istack-commons-runtime:2.21:istack-commons-runtime-2.21.jar:c33e67a0807095f02a0e2da139412dd7c4f9cc1a4c054b3e434f96831ba950f4',
-        'com.sun.xml.fastinfoset:FastInfoset:1.2.16:FastInfoset-1.2.16.jar:056f3a1e144409f21ed16afc26805f58e9a21f3fce1543c42d400719d250c511',
+        'com.sun.xml.fastinfoset:FastInfoset:1.2.13:FastInfoset-1.2.13.jar:27a77db909f3c2833c0b1a37c55af1db06045118ad2eed96ce567b6632bce038',
         'commons-codec:commons-codec:1.10:commons-codec-1.10.jar:4241dfa94e711d435f29a4604a3e2de5c4aa3c165e23bd066be6fc1fc4309569',
         'commons-logging:commons-logging:1.2:commons-logging-1.2.jar:daddea1ea0be0f56978ab3006b8ac92834afeefbd9b7e4e6316fca57df0fa636',
-        'it.unimi.dsi:fastutil:8.4.0:fastutil-8.4.0.jar:2ad2824a4a0a0eb836b52ee2fc84ba2134f44bce7bfa54015ae3f31c710a3071',
+        'it.unimi.dsi:fastutil:7.2.0:fastutil-7.2.0.jar:74fa208043740642f7e6eb09faba15965218ad2f50ce3020efb100136e4b591c',
-        'jakarta.activation:jakarta.activation-api:1.2.1:jakarta.activation-api-1.2.1.jar:8b0a0f52fa8b05c5431921a063ed866efaa41dadf2e3a7ee3e1961f2b0d9645b',
-        'jakarta.xml.bind:jakarta.xml.bind-api:2.3.2:jakarta.xml.bind-api-2.3.2.jar:69156304079bdeed9fc0ae3b39389f19b3cc4ba4443bc80508995394ead742ea',
         'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
         '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.bytebuddy:byte-buddy:1.9.12:byte-buddy-1.9.12.jar:3688c3d434bebc3edc5516296a2ed0f47b65e451071b4afecad84f902f0efc11',
-        'net.java.dev.jna:jna-platform:5.6.0:jna-platform-5.6.0.jar:9ecea8bf2b1b39963939d18b70464eef60c508fed8820f9dcaba0c35518eabf7',
-        'net.java.dev.jna:jna:5.6.0:jna-5.6.0.jar:5557e235a8aa2f9766d5dc609d67948f2a8832c2d796cea9ef1d6cbe0b3b7eaf',
-        'net.jcip:jcip-annotations:1.0:jcip-annotations-1.0.jar:be5805392060c71474bf6c9a67a099471274d30b83eef84bfc4e0889a4f1dcc0',
         '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-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
+        '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.apache.commons:commons-compress:1.12:commons-compress-1.12.jar:2c1542faf343185b7cab9c3d55c8ae5471d6d095d3887a4adefdbdf2984dc0b6',
         'org.apache.httpcomponents:httpclient:4.5.6:httpclient-4.5.6.jar:c03f813195e7a80e3608d0ddd8da80b21696a4c92a6a2298865bf149071551c7',
         'org.apache.httpcomponents:httpcore:4.4.10:httpcore-4.4.10.jar:78ba1096561957db1b55200a159b648876430342d15d461277e62360da19f6fd',
         'org.apache.httpcomponents:httpmime:4.5.6:httpmime-4.5.6.jar:0b2b1102c18d3c7e05a77214b9b7501a6f6056174ae5604e0e256776eda7553e',
+        '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:0.0.12-dev-40245c4a:obfs4proxy-android-0.0.12-dev-40245c4a.zip:8ab05a8f8391be2cb5ab2b665c281a06d9e3a756bd0f95a40a36ca927866ea82',
+        'org.briarproject:obfs4proxy-android:0.0.11-2:obfs4proxy-android-0.0.11-2.zip:57e55cbe87aa2aac210fdbb6cd8cdeafe15f825406a08ebf77a8b787aa2c6a8a',
-        'org.briarproject:tor-android:0.3.5.13:tor-android-0.3.5.13.zip:e0978db136731dae07774b722970cdae1e462fb5adc82845dd80a7e2d87f356c',
+        'org.briarproject:tor-android:0.3.5.10:tor-android-0.3.5.10.zip:edd83bf557fcff2105eaa0bdb3f607a6852ebe7360920929ae3039dd5f4774c5',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
         'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
-        'org.checkerframework:checker-qual:2.8.1:checker-qual-2.8.1.jar:9103499008bcecd4e948da29b17864abb64304e15706444ae209d17ebe0575df',
         'org.codehaus.groovy:groovy-all:2.4.15:groovy-all-2.4.15.jar:51d6c4e71782e85674239189499854359d380fb75e1a703756e3aaa5b98a5af0',
         'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',
-        'org.codehaus.mojo:animal-sniffer-annotations:1.18:animal-sniffer-annotations-1.18.jar:47f05852b48ee9baefef80fa3d8cea60efa4753c0013121dd7fe5eef2e5c729d',
+        'org.glassfish.jaxb:jaxb-core:2.2.11:jaxb-core-2.2.11.jar:37bcaee8ebb04362c8352a5bf6221b86967ecdab5164c696b10b9a2bb587b2aa',
-        'org.glassfish.jaxb:jaxb-runtime:2.3.2:jaxb-runtime-2.3.2.jar:e6e0a1e89fb6ff786279e6a0082d5cef52dc2ebe67053d041800737652b4fd1b',
+        'org.glassfish.jaxb:jaxb-runtime:2.2.11:jaxb-runtime-2.2.11.jar:a874f2351cfba8e2946be3002d10c18a6da8f21b52ba2acf52f2b85d5520ed70',
-        'org.glassfish.jaxb:txw2:2.3.2:txw2-2.3.2.jar:4a6a9f483388d461b81aa9a28c685b8b74c0597993bf1884b04eddbca95f48fe',
+        'org.glassfish.jaxb:txw2:2.2.11:txw2-2.2.11.jar:272a3ccad45a4511351920cd2a8633c53cab8d5220c7a92954da5526bb5eafea',
-        'org.hamcrest:hamcrest-core:2.1:hamcrest-core-2.1.jar:e09109e54a289d88506b9bfec987ddd199f4217c9464132668351b9a4f00bee9',
+        'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
-        'org.hamcrest:hamcrest-library:2.1:hamcrest-library-2.1.jar:b7e2b6895b3b679f0e47b6380fda391b225e9b78505db9d8bdde8d3cc8d52a21',
+        'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
-        'org.hamcrest:hamcrest:2.1:hamcrest-2.1.jar:ba93b2e3a562322ba432f0a1b53addcc55cb188253319a020ed77f824e692050',
+        'org.jetbrains.kotlin:kotlin-reflect:1.3.50:kotlin-reflect-1.3.50.jar:64583199ea5a54aefd1bd1595288925f784226ee562d1dd279011c6075b3d7a4',
-        'org.jetbrains.intellij.deps:trove4j:1.0.20181211:trove4j-1.0.20181211.jar:affb7c85a3c87bdcf69ff1dbb84de11f63dc931293934bc08cd7ab18de083601',
+        'org.jetbrains.kotlin:kotlin-stdlib-common:1.3.50:kotlin-stdlib-common-1.3.50.jar:8ce678e88e4ba018b66dacecf952471e4d7dfee156a8a819760a5a5ff29d323c',
-        'org.jetbrains.kotlin:kotlin-reflect:1.4.31:kotlin-reflect-1.4.31.jar:91fad0b42974a7d5811e30a61f05706e176b144235717c6de7e81e3a781028f2',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.50:kotlin-stdlib-jdk7-1.3.50.jar:9a026639e76212f8d57b86d55b075394c2e009f1979110751d34c05c5f75d57b',
-        'org.jetbrains.kotlin:kotlin-stdlib-common:1.4.31:kotlin-stdlib-common-1.4.31.jar:57962f44371a746b678218a0802a8712c6255206de9a69ede215e3aa4b044708',
+        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.3.50:kotlin-stdlib-jdk8-1.3.50.jar:1b351fb6e09c14b55525c74c1f4cf48942eae43c348b7bc764a5e6e423d4da0c',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.4.31:kotlin-stdlib-jdk7-1.4.31.jar:1f966e54e86cf4b7d7014afdce04e0f3ee4625084cda3494edccc7b84af52664',
+        'org.jetbrains.kotlin:kotlin-stdlib:1.3.50:kotlin-stdlib-1.3.50.jar:e6f05746ee0366d0b52825a090fac474dcf44082c9083bbb205bd16976488d6c',
-        'org.jetbrains.kotlin:kotlin-stdlib-jdk8:1.4.31:kotlin-stdlib-jdk8-1.4.31.jar:b2f8364435ebcb0106ff9d4415a11ffdef8ec7786ee6e5ed465a01556cbd1683',
+        'org.jetbrains.trove4j:trove4j:20160824:trove4j-20160824.jar:1917871c8deb468307a584680c87a44572f5a8b0b98c6d397fc0f5f86596dbe7',
-        'org.jetbrains.kotlin:kotlin-stdlib:1.4.31:kotlin-stdlib-1.4.31.jar:76a599d88b167e8ac90879b6daa722c6ad3452ba714c9aba19bd196544b97f1c',
         'org.jetbrains:annotations:13.0:annotations-13.0.jar:ace2a10dc8e2d5fd34925ecac03e4988b2c0f851650c94b8cef49ba1bd111478',
-        'org.jmock:jmock-imposters:2.12.0:jmock-imposters-2.12.0.jar:3b836269745a137c9b2347e8d7c2104845b126ef04f012d6bfd94f1a7dea7b09',
+        'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
-        'org.jmock:jmock-junit4:2.12.0:jmock-junit4-2.12.0.jar:3233062fc889637c151a24f1ee086bad04321ab7d8264fef279daff0fa27205b',
+        'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
-        'org.jmock:jmock-legacy:2.12.0:jmock-legacy-2.12.0.jar:dea3a9cca653d082e2fe7e40232e982fe03a9984c7d67ceff24f3e03fe580dcd',
+        'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
-        'org.jmock:jmock-testjar:2.12.0:jmock-testjar-2.12.0.jar:efefbcf6cd294d0e29f0c46eb2a3380d4ca4e1763ff719c69e2f2ac62f564a04',
+        'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
-        'org.jmock:jmock:2.12.0:jmock-2.12.0.jar:266d07314c0cd343c46ff8a55601272de8cf406807caf55e6f313295f83d10be',
+        'org.jvnet.staxex:stax-ex:1.7.7:stax-ex-1.7.7.jar:a31ff7d77163c0deb09e7fee59ad35ae44c2cee2cc8552a116ccd1583d813fb4',
-        'org.jvnet.staxex:stax-ex:1.8.1:stax-ex-1.8.1.jar:20522549056e9e50aa35ef0b445a2e47a53d06be0b0a9467d704e2483ffb049a',
+        'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
-        'org.objenesis:objenesis:3.0.1:objenesis-3.0.1.jar:7a8ff780b9ff48415d7c705f60030b0acaa616e7f823c98eede3b63508d4e984',
+        'org.ow2.asm:asm-analysis:6.0:asm-analysis-6.0.jar:2f1a6387219c3a6cc4856481f221b03bd9f2408a326d416af09af5d6f608c1f4',
-        'org.ow2.asm:asm-analysis:7.0:asm-analysis-7.0.jar:e981f8f650c4d900bb033650b18e122fa6b161eadd5f88978d08751f72ee8474',
+        'org.ow2.asm:asm-commons:6.0:asm-commons-6.0.jar:f1bce5c648a96a017bdcd01fe5d59af9845297fd7b79b81c015a6fbbd9719abf',
-        'org.ow2.asm:asm-commons:7.0:asm-commons-7.0.jar:fed348ef05958e3e846a3ac074a12af5f7936ef3d21ce44a62c4fa08a771927d',
+        'org.ow2.asm:asm-tree:6.0:asm-tree-6.0.jar:887998fb69727c8759e4d253f856822801e33f9fd4caa566b3ac58ee92106215',
-        'org.ow2.asm:asm-tree:7.0:asm-tree-7.0.jar:cfd7a0874f9de36a999c127feeadfbfe6e04d4a71ee954d7af3d853f0be48a6c',
+        'org.ow2.asm:asm-util:6.0:asm-util-6.0.jar:356afebdb0f870175262e5188f8709a3b17aa2a5a6a4b0340b04d4b449bca5f6',
-        'org.ow2.asm:asm-util:7.0:asm-util-7.0.jar:75fbbca440ef463f41c2b0ab1a80abe67e910ac486da60a7863cbcb5bae7e145',
+        'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
-        'org.ow2.asm:asm:7.0:asm-7.0.jar:b88ef66468b3c978ad0c97fd6e90979e56155b4ac69089ba7a44e9aa7ffe9acf',
+        'org.ow2.asm:asm:6.0:asm-6.0.jar:dd8971c74a4e697899a8e95caae4ea8760ea6c486dc6b97b1795e75760420461',
-        'org.ow2.asm:asm:7.1:asm-7.1.jar:4ab2fa2b6d2cc9ccb1eaa05ea329c407b47b13ed2915f62f8c4b8cc96258d4de',
-        'xerces:xercesImpl:2.12.0:xercesImpl-2.12.0.jar:b50d3a4ca502faa4d1c838acb8aa9480446953421f7327e338c5dda3da5e76d0',
-        'xml-apis:xml-apis:1.4.01:xml-apis-1.4.01.jar:a840968176645684bb01aed376e067ab39614885f9eee44abe35a5f20ebe7fad',
     ]
 }

bramble-api/build.gradle

@@ -10,9 +10,10 @@ dependencies {
 	implementation "com.google.dagger:dagger:2.24"
 	implementation 'com.google.code.findbugs:jsr305:3.0.2'
 
-	testImplementation "junit:junit:$junit_version"
+	testImplementation 'junit:junit:4.12'
-	testImplementation "org.jmock:jmock:$jmock_version"
+	testImplementation "org.jmock:jmock:2.8.2"
-	testImplementation "org.jmock:jmock-junit4:$jmock_version"
+	testImplementation "org.jmock:jmock-junit4:2.8.2"
+	testImplementation "org.jmock:jmock-legacy:2.8.2"
 
 	signature 'org.codehaus.mojo.signature:java16:1.1@signature'
 }

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

@@ -0,0 +1,25 @@
+package org.briarproject.bramble.api;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+import javax.annotation.Nullable;
+
+/**
+ * An item that can be consumed once.
+ */
+@NotNullByDefault
+public class Consumable<T> {
+
+	private final AtomicReference<T> reference;
+
+	public Consumable(T item) {
+		reference = new AtomicReference<>(item);
+	}
+
+	@Nullable
+	public T consume() {
+		return reference.getAndSet(null);
+	}
+}

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

@@ -6,7 +6,4 @@ package org.briarproject.bramble.api;
 public interface FeatureFlags {
 
 	boolean shouldEnableImageAttachments();
-
-	boolean shouldEnableProfilePictures();
-
 }

bramble-api/src/main/java/org/briarproject/bramble/api/account/AccountManager.java

@@ -2,7 +2,6 @@ package org.briarproject.bramble.api.account;
 
 import org.briarproject.bramble.api.crypto.DecryptionException;
 import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.api.identity.Identity;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
@@ -44,17 +43,6 @@ public interface AccountManager {
 	 */
 	boolean createAccount(String name, String password);
 
-	/**
-	 * Restores a given identity by registering it with the
-	 * {@link IdentityManager}.  Creates a database key, encrypts it with the
-	 * given password and stores it on disk. {@link #accountExists()} will
-	 * return true after this method returns true.
- 	 * @param identity
-	 * @param password
-	 * @return
-	 */
-	boolean restoreAccount(Identity identity, String password);
-
 	/**
 	 * Deletes all account state from disk. {@link #accountExists()} will
 	 * return false after this method returns.

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

@@ -35,24 +35,24 @@ public interface ClientHelper {
 
 	Message createMessageForStoringMetadata(GroupId g);
 
-	Message getMessage(MessageId m) throws DbException;
+	Message getSmallMessage(MessageId m) throws DbException;
 
-	Message getMessage(Transaction txn, MessageId m) throws DbException;
+	Message getSmallMessage(Transaction txn, MessageId m) throws DbException;
 
-	BdfList getMessageAsList(MessageId m) throws DbException, FormatException;
+	BdfList getSmallMessageAsList(MessageId m)
+			throws DbException, FormatException;
 
-	BdfList getMessageAsList(Transaction txn, MessageId m) throws DbException,
+	BdfList getSmallMessageAsList(Transaction txn, MessageId m)
-			FormatException;
+			throws DbException, FormatException;
 
-	BdfDictionary getGroupMetadataAsDictionary(GroupId g) throws DbException,
+	BdfDictionary getGroupMetadataAsDictionary(GroupId g)
-			FormatException;
+			throws DbException, FormatException;
 
 	BdfDictionary getGroupMetadataAsDictionary(Transaction txn, GroupId g)
 			throws DbException, FormatException;
 
 	BdfDictionary getMessageMetadataAsDictionary(MessageId m)
-			throws DbException,
+			throws DbException, FormatException;
-			FormatException;
 
 	BdfDictionary getMessageMetadataAsDictionary(Transaction txn, MessageId m)
 			throws DbException, FormatException;
@@ -67,8 +67,8 @@ public interface ClientHelper {
 			BdfDictionary query) throws DbException, FormatException;
 
 	Map<MessageId, BdfDictionary> getMessageMetadataAsDictionary(
-			Transaction txn, GroupId g, BdfDictionary query) throws DbException,
+			Transaction txn, GroupId g, BdfDictionary query)
-			FormatException;
+			throws DbException, FormatException;
 
 	void mergeGroupMetadata(GroupId g, BdfDictionary metadata)
 			throws DbException, FormatException;

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

@@ -1,9 +0,0 @@
-package org.briarproject.bramble.api.contact;
-
-/**
- * Record types for the contact exchange protocol.
- */
-public interface ContactExchangeRecordTypes {
-
-	byte CONTACT_INFO = 0;
-}

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

@@ -3,7 +3,6 @@ package org.briarproject.bramble.api.contact;
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.UnsupportedVersionException;
-import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.db.ContactExistsException;
 import org.briarproject.bramble.api.db.DbException;
@@ -12,6 +11,7 @@ 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;
+import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
@@ -49,10 +49,6 @@ public interface ContactManager {
 			SecretKey rootKey, long timestamp, boolean alice, boolean verified,
 			boolean active) throws DbException;
 
-	ContactId addContact(Transaction txn, Author remote, AuthorId local,
-			PublicKey handshake, boolean verified)
-			throws DbException, GeneralSecurityException;
-
 	/**
 	 * Stores a contact associated with the given local and remote pseudonyms,
 	 * replacing the given pending contact, derives and stores handshake mode
@@ -183,11 +179,6 @@ public interface ContactManager {
 	 */
 	Collection<Contact> getContacts() throws DbException;
 
-	/**
-	 * Returns all contacts.
-	 */
-	Collection<Contact> getContacts(Transaction txn) throws DbException;
-
 	/**
 	 * Removes a contact and all associated state.
 	 */
@@ -210,19 +201,6 @@ public interface ContactManager {
 	void setContactAlias(ContactId c, @Nullable String alias)
 			throws DbException;
 
-	/**
-	 * Sets the contact's handshake public key
-	 */
-	void setHandshakePublicKey(Transaction txn, ContactId c,
-			PublicKey handshakePublicKey) throws DbException,
-			GeneralSecurityException;
-
-	/**
-	 * Sets the contact's handshake public key
-	 */
-	void setHandshakePublicKey(ContactId c, PublicKey handshakePublicKey)
-			throws DbException, GeneralSecurityException;
-
 	/**
 	 * Returns true if a contact with this {@code remoteAuthorId} belongs to
 	 * the local pseudonym with this {@code localAuthorId}.
@@ -237,6 +215,16 @@ public interface ContactManager {
 	boolean contactExists(AuthorId remoteAuthorId, AuthorId localAuthorId)
 			throws DbException;
 
+	/**
+	 * Returns the {@link AuthorInfo} for the given author.
+	 */
+	AuthorInfo getAuthorInfo(AuthorId a) throws DbException;
+
+	/**
+	 * Returns the {@link AuthorInfo} for the given author.
+	 */
+	AuthorInfo getAuthorInfo(Transaction txn, AuthorId a) throws DbException;
+
 	interface ContactHook {
 
 		/**

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

@@ -24,19 +24,6 @@ public interface HandshakeManager {
 	HandshakeResult handshake(PendingContactId p, InputStream in,
 			StreamWriter out) throws DbException, IOException;
 
-	/**
-	 * Handshakes with the given contact. Returns an ephemeral master key
-	 * authenticated with both parties' handshake key pairs and a flag
-	 * indicating whether the local peer is Alice or Bob.
-	 *
-	 * @param in An incoming stream for the handshake, which must be secured in
-	 * handshake mode
-	 * @param out An outgoing stream for the handshake, which must be secured
-	 * in handshake mode
-	 */
-	HandshakeResult handshake(ContactId c, InputStream in, StreamWriter out)
-			throws DbException, IOException;
-
 	class HandshakeResult {
 
 		private final SecretKey masterKey;

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

@@ -19,10 +19,4 @@ public interface StreamDecrypterFactory {
 	 */
 	StreamDecrypter createContactExchangeStreamDecrypter(InputStream in,
 			SecretKey headerKey);
-
-	/**
-	 * Creates a {@link StreamDecrypter} for decrypting a log stream.
-	 */
-	StreamDecrypter createLogStreamDecrypter(InputStream in,
-			SecretKey headerKey);
 }

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

@@ -17,12 +17,6 @@ public interface StreamEncrypterFactory {
 	 * Creates a {@link StreamEncrypter} for encrypting a contact exchange
 	 * stream.
 	 */
-	StreamEncrypter createContactExchangeStreamEncrypter(OutputStream out,
+	StreamEncrypter createContactExchangeStreamDecrypter(OutputStream out,
-			SecretKey headerKey);
-
-	/**
-	 * Creates a {@link StreamEncrypter} for encrypting a log stream.
-	 */
-	StreamEncrypter createLogStreamEncrypter(OutputStream out,
 			SecretKey headerKey);
 }

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

@@ -163,27 +163,23 @@ public interface DatabaseComponent extends TransactionManager {
 	 * less than or equal to the given length, for transmission over a
 	 * transport with the given maximum latency. Returns null if there are no
 	 * sendable messages that fit in the given length.
+	 *
+	 * @param small True if only single-block messages should be sent
 	 */
 	@Nullable
 	Collection<Message> generateBatch(Transaction txn, ContactId c,
-			int maxLength, int maxLatency) throws DbException;
+			int maxLength, int maxLatency, boolean small) throws DbException;
 
 	/**
 	 * Returns an offer for the given contact for transmission over a
 	 * transport with the given maximum latency, or null if there are no
 	 * messages to offer.
+	 *
+	 * @param small True if only single-block messages should be offered
 	 */
 	@Nullable
 	Offer generateOffer(Transaction txn, ContactId c, int maxMessages,
-			int maxLatency) throws DbException;
+			int maxLatency, boolean small) throws DbException;
-
-	/**
-	 * Returns a request for the given contact, or null if there are no
-	 * messages to request.
-	 */
-	@Nullable
-	Request generateRequest(Transaction txn, ContactId c, int maxMessages)
-			throws DbException;
 
 	/**
 	 * Returns a batch of messages for the given contact, with a total length
@@ -272,13 +268,14 @@ public interface DatabaseComponent extends TransactionManager {
 	Collection<Identity> getIdentities(Transaction txn) throws DbException;
 
 	/**
-	 * Returns the message with the given ID.
+	 * Returns the single-block message with the given ID.
 	 * <p/>
 	 * Read-only.
 	 *
 	 * @throws MessageDeletedException if the message has been deleted
+	 * @throws MessageTooLargeException if the message has more than one block
 	 */
-	Message getMessage(Transaction txn, MessageId m) throws DbException;
+	Message getSmallMessage(Transaction txn, MessageId m) throws DbException;
 
 	/**
 	 * Returns the IDs of all delivered messages in the given group.
@@ -546,11 +543,6 @@ public interface DatabaseComponent extends TransactionManager {
 	void setContactAlias(Transaction txn, ContactId c, @Nullable String alias)
 			throws DbException;
 
-	/**
-	 * Sets the remote handshake public key for a given contact
-	 */
-	void setHandshakePublicKey(Transaction txn, ContactId c, PublicKey handshakePublicKey) throws DbException;
-
 	/**
 	 * Sets the given group's visibility to the given contact.
 	 */

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

@@ -0,0 +1,8 @@
+package org.briarproject.bramble.api.db;
+
+/**
+ * Thrown when a multi-block message is requested from the database via a
+ * method that is only suitable for requesting single-block messages.
+ */
+public class MessageTooLargeException extends DbException {
+}

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

@@ -1,8 +1,6 @@
-package org.briarproject.briar.api.identity;
+package org.briarproject.bramble.api.identity;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.nullsafety.NullSafety;
-import org.briarproject.briar.api.attachment.AttachmentHeader;
 
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
@@ -22,18 +20,14 @@ public class AuthorInfo {
 	private final Status status;
 	@Nullable
 	private final String alias;
-	@Nullable
-	private final AttachmentHeader avatarHeader;
 
-	public AuthorInfo(Status status, @Nullable String alias,
+	public AuthorInfo(Status status, @Nullable String alias) {
-			@Nullable AttachmentHeader avatarHeader) {
 		this.status = status;
 		this.alias = alias;
-		this.avatarHeader = avatarHeader;
 	}
 
 	public AuthorInfo(Status status) {
-		this(status, null, null);
+		this(status, null);
 	}
 
 	public Status getStatus() {
@@ -45,11 +39,6 @@ public class AuthorInfo {
 		return alias;
 	}
 
-	@Nullable
-	public AttachmentHeader getAvatarHeader() {
-		return avatarHeader;
-	}
-
 	@Override
 	public int hashCode() {
 		int hashCode = status.ordinal();
@@ -62,9 +51,6 @@ public class AuthorInfo {
 		if (!(o instanceof AuthorInfo)) return false;
 		AuthorInfo info = (AuthorInfo) o;
 		return status == info.status &&
-				// aliases are equal
+				(alias == null ? info.alias == null : alias.equals(info.alias));
-				NullSafety.equals(alias, info.alias) &&
-				// avatars are equal
-				NullSafety.equals(avatarHeader, info.avatarHeader);
 	}
 }

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

@@ -26,11 +26,6 @@ public interface IdentityManager {
 	 */
 	void registerIdentity(Identity i);
 
-	/**
-	 * Returns the cached local identity or loads it from the database.
-	 */
-	Identity getIdentity(Transaction txn) throws DbException;
-
 	/**
 	 * Returns the cached local identity or loads it from the database.
 	 */

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

@@ -8,12 +8,11 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class NetworkStatus {
 
-	private final boolean connected, wifi, ipv6Only;
+	private final boolean connected, wifi;
 
-	public NetworkStatus(boolean connected, boolean wifi, boolean ipv6Only) {
+	public NetworkStatus(boolean connected, boolean wifi) {
 		this.connected = connected;
 		this.wifi = wifi;
-		this.ipv6Only = ipv6Only;
 	}
 
 	public boolean isConnected() {
@@ -23,8 +22,4 @@ public class NetworkStatus {
 	public boolean isWifi() {
 		return wifi;
 	}
-
-	public boolean isIpv6Only() {
-		return ipv6Only;
-	}
 }

bramble-api/src/main/java/org/briarproject/bramble/api/nullsafety/NullSafety.java

@@ -29,12 +29,4 @@ public class NullSafety {
 	public static void requireNull(@Nullable Object o) {
 		if (o != null) throw new AssertionError();
 	}
-
-	/**
-	 * Stand-in for {@code Objects.equals()}.
-	 */
-	public static boolean equals(@Nullable Object a, @Nullable Object b) {
-		return (a == b) || (a != null && a.equals(b));
-	}
-
 }

bramble-api/src/main/java/org/briarproject/bramble/api/properties/TransportPropertyManager.java

@@ -74,13 +74,6 @@ public interface TransportPropertyManager {
 	TransportProperties getRemoteProperties(ContactId c, TransportId t)
 			throws DbException;
 
-	/**
-	 * Returns the remote transport properties for the given contact and
-	 * transport.
-	 */
-	TransportProperties getRemoteProperties(Transaction txn, ContactId c,
-			TransportId t) throws DbException;
-
 	/**
 	 * Merges the given properties with the existing local properties for the
 	 * given transport.

bramble-api/src/main/java/org/briarproject/bramble/api/reporting/DevConfig.java

@@ -13,6 +13,4 @@ public interface DevConfig {
 	String getDevOnionAddress();
 
 	File getReportDir();
-
-	File getLogcatFile();
 }

bramble-api/src/main/java/org/briarproject/bramble/api/reporting/DevReporter.java

@@ -23,8 +23,6 @@ public interface DevReporter {
 
 	/**
 	 * Sends any reports previously stored on disk.
-	 *
-	 * @return The number of reports that were sent.
 	 */
-	int sendReports();
+	void sendReports();
 }

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

@@ -29,10 +29,15 @@ public interface SyncConstants {
 	 */
 	int MESSAGE_HEADER_LENGTH = UniqueId.LENGTH + 8;
 
+	/**
+	 * The maximum length of a block in bytes.
+	 */
+	int MAX_BLOCK_LENGTH = 32 * 1024; // 32 KiB
+
 	/**
 	 * The maximum length of a message body in bytes.
 	 */
-	int MAX_MESSAGE_BODY_LENGTH = 32 * 1024; // 32 KiB
+	int MAX_MESSAGE_BODY_LENGTH = MAX_BLOCK_LENGTH;
 
 	/**
 	 * The maximum length of a message in bytes.

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

@@ -1,26 +0,0 @@
-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 javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when a message is offered by a contact and needs
- * to be requested.
- */
-@Immutable
-@NotNullByDefault
-public class MessageToRequestEvent extends Event {
-
-	private final ContactId contactId;
-
-	public MessageToRequestEvent(ContactId contactId) {
-		this.contactId = contactId;
-	}
-
-	public ContactId getContactId() {
-		return contactId;
-	}
-}

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

@@ -7,16 +7,16 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import javax.annotation.concurrent.Immutable;
 
 /**
- * An event that is broadcast when a message is received from, or offered by, a
+ * An event that is broadcast when one or more messages are received from, or
- * contact and needs to be acknowledged.
+ * offered by, a contact and need to be acknowledged.
  */
 @Immutable
 @NotNullByDefault
-public class MessageToAckEvent extends Event {
+public class MessagesToAckEvent extends Event {
 
 	private final ContactId contactId;
 
-	public MessageToAckEvent(ContactId contactId) {
+	public MessagesToAckEvent(ContactId contactId) {
 		this.contactId = contactId;
 	}
 

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

@@ -0,0 +1,39 @@
+package org.briarproject.bramble.api.sync.event;
+
+import org.briarproject.bramble.api.Consumable;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
+
+import java.util.Collection;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when one or more messages are offered by a
+ * contact and need to be requested.
+ */
+@Immutable
+@NotNullByDefault
+public class MessagesToRequestEvent extends Event {
+
+	private final ContactId contactId;
+	private final Consumable<Collection<MessageId>> ids;
+
+	public MessagesToRequestEvent(ContactId contactId,
+			Collection<MessageId> ids) {
+		this.contactId = contactId;
+		this.ids = new Consumable<>(ids);
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	@Nullable
+	public Collection<MessageId> consumeIds() {
+		return ids.consume();
+	}
+}

bramble-api/src/main/java/org/briarproject/bramble/api/transport/KeyManager.java

@@ -35,20 +35,6 @@ public interface KeyManager {
 			ContactId c, SecretKey rootKey, long timestamp, boolean alice,
 			boolean active) throws DbException;
 
-	/**
-	 * Derives and stores a set of rotation mode transport keys for
-	 * communicating with the given contact over each transport and returns the
-	 * key set IDs.
-	 * <p/>
-	 * {@link StreamContext StreamContexts} for the contact can be created
-	 * after this method has returned.
-	 *
-	 * @param alice True if the local party is Alice
-	 * @param active Whether the derived keys can be used for outgoing streams
-	 */
-	Map<TransportId, KeySetId> addRotationKeys(ContactId c, SecretKey rootKey,
-			long timestamp, boolean alice, boolean active) throws DbException;
-
 	/**
 	 * Informs the key manager that a new contact has been added. Derives and
 	 * stores a set of handshake mode transport keys for communicating with the

bramble-api/src/main/java/org/briarproject/bramble/api/transport/StreamReaderFactory.java

@@ -16,13 +16,8 @@ public interface StreamReaderFactory {
 
 	/**
 	 * Creates an {@link InputStream InputStream} for reading from a contact
-	 * exchange stream.
+	 * exchangestream.
 	 */
 	InputStream createContactExchangeStreamReader(InputStream in,
 			SecretKey headerKey);
-
-	/**
-	 * Creates an {@link InputStream} for reading from a log stream.
-	 */
-	InputStream createLogStreamReader(InputStream in, SecretKey headerKey);
 }

bramble-api/src/main/java/org/briarproject/bramble/api/transport/StreamWriterFactory.java

@@ -7,19 +7,17 @@ import java.io.OutputStream;
 
 @NotNullByDefault
 public interface StreamWriterFactory {
+
 	/**
-	 * Creates a {@link StreamWriter} for writing to a transport stream.
+	 * Creates an {@link OutputStream OutputStream} for writing to a
+	 * transport stream
 	 */
 	StreamWriter createStreamWriter(OutputStream out, StreamContext ctx);
 
 	/**
-	 * Creates a {@link StreamWriter} for writing to a contact exchange stream.
+	 * Creates an {@link OutputStream OutputStream} for writing to a contact
+	 * exchange stream.
 	 */
 	StreamWriter createContactExchangeStreamWriter(OutputStream out,
 			SecretKey headerKey);
-
-	/**
-	 * Creates a {@link StreamWriter} for writing to a log stream.
-	 */
-	StreamWriter createLogStreamWriter(OutputStream out, SecretKey headerKey);
 }

bramble-api/src/test/java/org/briarproject/bramble/api/identity/AuthorInfoTest.java

@@ -0,0 +1,42 @@
+package org.briarproject.bramble.api.identity;
+
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.junit.Test;
+
+import static org.briarproject.bramble.api.identity.AuthorInfo.Status.NONE;
+import static org.briarproject.bramble.api.identity.AuthorInfo.Status.VERIFIED;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+public class AuthorInfoTest extends BrambleTestCase {
+
+	@Test
+	public void testEquals() {
+		assertEquals(
+				new AuthorInfo(NONE),
+				new AuthorInfo(NONE, null)
+		);
+		assertEquals(
+				new AuthorInfo(NONE, "test"),
+				new AuthorInfo(NONE, "test")
+		);
+
+		assertNotEquals(
+				new AuthorInfo(NONE),
+				new AuthorInfo(VERIFIED)
+		);
+		assertNotEquals(
+				new AuthorInfo(NONE, "test"),
+				new AuthorInfo(NONE)
+		);
+		assertNotEquals(
+				new AuthorInfo(NONE),
+				new AuthorInfo(NONE, "test")
+		);
+		assertNotEquals(
+				new AuthorInfo(NONE, "a"),
+				new AuthorInfo(NONE, "b")
+		);
+	}
+
+}

bramble-api/witness.gradle

@@ -1,27 +1,24 @@
 dependencyVerification {
     verify = [
-        'cglib:cglib:3.2.8:cglib-3.2.8.jar:3f64de999ecc5595dc84ca8ff0879d8a34c8623f9ef3c517a53ed59023fcb9db',
+        'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
-        'com.google.code.findbugs:annotations:3.0.1:annotations-3.0.1.jar:6b47ff0a6de0ce17cbedc3abb0828ca5bce3009d53ea47b3723ff023c4742f79',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
         'com.google.dagger:dagger:2.24:dagger-2.24.jar:550a6e46a6dfcdf1d764887b6090cea94f783327e50e5c73754f18facfc70b64',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
-        'net.bytebuddy:byte-buddy:1.9.12:byte-buddy-1.9.12.jar:3688c3d434bebc3edc5516296a2ed0f47b65e451071b4afecad84f902f0efc11',
+        'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
-        'net.jcip:jcip-annotations:1.0:jcip-annotations-1.0.jar:be5805392060c71474bf6c9a67a099471274d30b83eef84bfc4e0889a4f1dcc0',
+        'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
-        'org.apache-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
+        'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
         'org.codehaus.mojo.signature:java16:1.1:java16-1.1.signature:53799223a2c98dba2d0add810bed76315460df285c69e4f397ae6098f87dd619',
         '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:2.1:hamcrest-core-2.1.jar:e09109e54a289d88506b9bfec987ddd199f4217c9464132668351b9a4f00bee9',
+        'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
-        'org.hamcrest:hamcrest-library:2.1:hamcrest-library-2.1.jar:b7e2b6895b3b679f0e47b6380fda391b225e9b78505db9d8bdde8d3cc8d52a21',
+        'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
-        'org.hamcrest:hamcrest:2.1:hamcrest-2.1.jar:ba93b2e3a562322ba432f0a1b53addcc55cb188253319a020ed77f824e692050',
+        'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
-        'org.jmock:jmock-imposters:2.12.0:jmock-imposters-2.12.0.jar:3b836269745a137c9b2347e8d7c2104845b126ef04f012d6bfd94f1a7dea7b09',
+        'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
-        'org.jmock:jmock-junit4:2.12.0:jmock-junit4-2.12.0.jar:3233062fc889637c151a24f1ee086bad04321ab7d8264fef279daff0fa27205b',
+        'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
-        'org.jmock:jmock-legacy:2.12.0:jmock-legacy-2.12.0.jar:dea3a9cca653d082e2fe7e40232e982fe03a9984c7d67ceff24f3e03fe580dcd',
+        'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
-        'org.jmock:jmock-testjar:2.12.0:jmock-testjar-2.12.0.jar:efefbcf6cd294d0e29f0c46eb2a3380d4ca4e1763ff719c69e2f2ac62f564a04',
+        'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
-        'org.jmock:jmock:2.12.0:jmock-2.12.0.jar:266d07314c0cd343c46ff8a55601272de8cf406807caf55e6f313295f83d10be',
-        'org.objenesis:objenesis:3.0.1:objenesis-3.0.1.jar:7a8ff780b9ff48415d7c705f60030b0acaa616e7f823c98eede3b63508d4e984',
         'org.ow2.asm:asm-all:5.2:asm-all-5.2.jar:7fbffbc1db3422e2101689fd88df8384b15817b52b9b2b267b9f6d2511dc198d',
-        'org.ow2.asm:asm:7.1:asm-7.1.jar:4ab2fa2b6d2cc9ccb1eaa05ea329c407b47b13ed2915f62f8c4b8cc96258d4de',
+        'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
     ]
 }

bramble-core/build.gradle

@@ -10,7 +10,7 @@ apply from: '../dagger.gradle'
 
 dependencies {
 	implementation project(path: ':bramble-api', configuration: 'default')
-	implementation 'org.bouncycastle:bcprov-jdk15on:1.65'
+	implementation 'com.madgag.spongycastle:core:1.58.0.0'
 	implementation 'com.h2database:h2:1.4.192' // The last version that supports Java 1.6
 	implementation 'org.bitlet:weupnp:0.1.4'
 	implementation 'net.i2p.crypto:eddsa:0.2.0'
@@ -21,25 +21,16 @@ dependencies {
 
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
 	testImplementation 'org.hsqldb:hsqldb:2.3.5' // The last version that supports Java 1.6
-	testImplementation 'net.jodah:concurrentunit:0.4.2'
+	testImplementation 'junit:junit:4.12'
-	testImplementation "junit:junit:$junit_version"
+	testImplementation "org.jmock:jmock:2.8.2"
-	testImplementation "org.jmock:jmock:$jmock_version"
+	testImplementation "org.jmock:jmock-junit4:2.8.2"
-	testImplementation "org.jmock:jmock-junit4:$jmock_version"
+	testImplementation "org.jmock:jmock-legacy:2.8.2"
-	testImplementation "org.jmock:jmock-imposters:$jmock_version"
 
 	testAnnotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 
 	signature 'org.codehaus.mojo.signature:java16:1.1@signature'
 }
 
-animalsniffer {
-	// Allow requireNonNull: Android desugaring rewrites it (so it's safe for us to use),
-	// and it gets used when passing method references instead of lambdas with Java 11.
-	// Note that this line allows *all* methods from java.util.Objects.
-	// That's the best that we can do with the configuration options that Animal Sniffer offers.
-	ignore 'java.util.Objects'
-}
-
 // needed to make test output available to bramble-java
 configurations {
 	testOutput.extendsFrom(testCompile)

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

@@ -176,18 +176,6 @@ class AccountManagerImpl implements AccountManager {
 		}
 	}
 
-	public boolean restoreAccount(Identity identity, String password) {
-		synchronized (stateChangeLock) {
-			if (hasDatabaseKey())
-				throw new AssertionError("Already have a database key");
-			identityManager.registerIdentity(identity);
-			SecretKey key = crypto.generateSecretKey();
-			if (!encryptAndStoreDatabaseKey(key, password)) return false;
-			databaseKey = key;
-			return true;
-		}
-	}
-
 	@GuardedBy("stateChangeLock")
 	private boolean encryptAndStoreDatabaseKey(SecretKey key, String password) {
 		byte[] plaintext = key.getBytes();

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

@@ -116,25 +116,27 @@ class ClientHelperImpl implements ClientHelper {
 	}
 
 	@Override
-	public Message getMessage(MessageId m) throws DbException {
+	public Message getSmallMessage(MessageId m) throws DbException {
-		return db.transactionWithResult(true, txn -> getMessage(txn, m));
+		return db.transactionWithResult(true, txn -> getSmallMessage(txn, m));
 	}
 
 	@Override
-	public Message getMessage(Transaction txn, MessageId m) throws DbException {
+	public Message getSmallMessage(Transaction txn, MessageId m)
-		return db.getMessage(txn, m);
+			throws DbException {
+		return db.getSmallMessage(txn, m);
 	}
 
 	@Override
-	public BdfList getMessageAsList(MessageId m) throws DbException,
+	public BdfList getSmallMessageAsList(MessageId m)
-			FormatException {
-		return db.transactionWithResult(true, txn -> getMessageAsList(txn, m));
-	}
-
-	@Override
-	public BdfList getMessageAsList(Transaction txn, MessageId m)
 			throws DbException, FormatException {
-		return toList(db.getMessage(txn, m).getBody());
+		return db.transactionWithResult(true, txn ->
+				getSmallMessageAsList(txn, m));
+	}
+
+	@Override
+	public BdfList getSmallMessageAsList(Transaction txn, MessageId m)
+			throws DbException, FormatException {
+		return toList(db.getSmallMessage(txn, m).getBody());
 	}
 
 	@Override

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

@@ -76,7 +76,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 		ioExecutor.execute(new IncomingDuplexSyncConnection(keyManager,
 				connectionRegistry, streamReaderFactory, streamWriterFactory,
 				syncSessionFactory, transportPropertyManager, ioExecutor,
-				t, d, handshakeManager));
+				t, d));
 	}
 
 	@Override
@@ -101,7 +101,7 @@ class ConnectionManagerImpl implements ConnectionManager {
 		ioExecutor.execute(new OutgoingDuplexSyncConnection(keyManager,
 				connectionRegistry, streamReaderFactory, streamWriterFactory,
 				syncSessionFactory, transportPropertyManager, ioExecutor,
-				secureRandom, handshakeManager, c, t, d));
+				secureRandom, c, t, d));
 	}
 
 	@Override

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

@@ -3,7 +3,6 @@ package org.briarproject.bramble.connection;
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.connection.InterruptibleConnection;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.HandshakeManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportConnectionReader;
 import org.briarproject.bramble.api.plugin.TransportConnectionWriter;

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

@@ -2,7 +2,6 @@ package org.briarproject.bramble.connection;
 
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.HandshakeManager;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
@@ -14,11 +13,9 @@ import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
 import org.briarproject.bramble.api.transport.StreamContext;
 import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
 import org.briarproject.bramble.api.transport.StreamWriterFactory;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.util.concurrent.Executor;
 
 import static java.util.logging.Level.WARNING;
@@ -27,10 +24,6 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 @NotNullByDefault
 class IncomingDuplexSyncConnection extends DuplexSyncConnection
 		implements Runnable {
-	private final HandshakeManager handshakeManager;
-
-	// FIXME: Exchange timestamp as part of handshake protocol?
-	private static final long TIMESTAMP = 1617235200; // 1 April 2021 00:00 UTC
 
 	IncomingDuplexSyncConnection(KeyManager keyManager,
 			ConnectionRegistry connectionRegistry,
@@ -39,18 +32,14 @@ class IncomingDuplexSyncConnection extends DuplexSyncConnection
 			SyncSessionFactory syncSessionFactory,
 			TransportPropertyManager transportPropertyManager,
 			Executor ioExecutor, TransportId transportId,
-			DuplexTransportConnection connection,
+			DuplexTransportConnection connection) {
-			HandshakeManager handshakeManager) {
 		super(keyManager, connectionRegistry, streamReaderFactory,
 				streamWriterFactory, syncSessionFactory,
 				transportPropertyManager, ioExecutor, transportId, connection);
-		this.handshakeManager = handshakeManager;
 	}
 
 	@Override
 	public void run() {
-		LOG.info("Running IncomingDuplexSyncConnection on transport " +
-				transportId.getString());
 		// Read and recognise the tag
 		StreamContext ctx = recogniseTag(reader, transportId);
 		if (ctx == null) {
@@ -65,22 +54,10 @@ class IncomingDuplexSyncConnection extends DuplexSyncConnection
 			return;
 		}
 		if (ctx.isHandshakeMode()) {
-			if (!performHandshake(ctx, contactId)) {
+			// TODO: Support handshake mode for contacts
-				LOG.warning("Handshake failed");
+			LOG.warning("Received handshake tag, expected rotation mode");
-				return;
+			onReadError(true);
-			}
+			return;
-			// Allocate a rotation mode stream context
-			ctx = allocateStreamContext(contactId, transportId);
-			if (ctx == null) {
-				LOG.warning("Could not allocate stream context");
-				onWriteError();
-				return;
-			}
-			if (ctx.isHandshakeMode()) {
-				LOG.warning("Got handshake mode context after handshaking");
-				onWriteError();
-				return;
-			}
 		}
 		connectionRegistry.registerIncomingConnection(contactId, transportId,
 				this);
@@ -126,35 +103,5 @@ class IncomingDuplexSyncConnection extends DuplexSyncConnection
 			onWriteError();
 		}
 	}
-
-	private boolean performHandshake(StreamContext ctxIn, ContactId contactId) {
-		LOG.info("Performing handshake (Incoming)");
-		// Allocate the outgoing stream context
-		StreamContext ctxOut =
-				allocateStreamContext(contactId, transportId);
-		if (ctxOut == null) {
-			LOG.warning("Could not allocate stream context");
-			onReadError(true);
-			return false;
-		}
-		try {
-			InputStream in = streamReaderFactory.createStreamReader(
-					reader.getInputStream(), ctxIn);
-			// Flush the output stream to send the outgoing stream header
-			StreamWriter out = streamWriterFactory.createStreamWriter(
-					writer.getOutputStream(), ctxOut);
-			out.getOutputStream().flush();
-			HandshakeManager.HandshakeResult result =
-					handshakeManager.handshake(contactId, in, out);
-			keyManager.addRotationKeys(contactId, result.getMasterKey(),
-					TIMESTAMP, result.isAlice(), true);
-			LOG.info("Rotation keys added");
-			return true;
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			onReadError(true);
-			return false;
-		}
-	}
 }
 

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

@@ -2,7 +2,6 @@ package org.briarproject.bramble.connection;
 
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactId;
-import org.briarproject.bramble.api.contact.HandshakeManager;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.plugin.TransportId;
@@ -15,11 +14,9 @@ import org.briarproject.bramble.api.sync.SyncSessionFactory;
 import org.briarproject.bramble.api.transport.KeyManager;
 import org.briarproject.bramble.api.transport.StreamContext;
 import org.briarproject.bramble.api.transport.StreamReaderFactory;
-import org.briarproject.bramble.api.transport.StreamWriter;
 import org.briarproject.bramble.api.transport.StreamWriterFactory;
 
 import java.io.IOException;
-import java.io.InputStream;
 import java.security.SecureRandom;
 import java.util.concurrent.Executor;
 
@@ -31,38 +28,26 @@ import static org.briarproject.bramble.util.LogUtils.logException;
 class OutgoingDuplexSyncConnection extends DuplexSyncConnection
 		implements Runnable {
 
-	// FIXME: Exchange timestamp as part of handshake protocol?
-	private static final long TIMESTAMP = 1617235200; // 1 April 2021 00:00 UTC
-
 	private final SecureRandom secureRandom;
-	private final HandshakeManager handshakeManager;
 	private final ContactId contactId;
 
-	OutgoingDuplexSyncConnection(
+	OutgoingDuplexSyncConnection(KeyManager keyManager,
-			KeyManager keyManager,
 			ConnectionRegistry connectionRegistry,
 			StreamReaderFactory streamReaderFactory,
 			StreamWriterFactory streamWriterFactory,
 			SyncSessionFactory syncSessionFactory,
 			TransportPropertyManager transportPropertyManager,
-			Executor ioExecutor,
+			Executor ioExecutor, SecureRandom secureRandom, ContactId contactId,
-			SecureRandom secureRandom,
+			TransportId transportId, DuplexTransportConnection connection) {
-			HandshakeManager handshakeManager,
-			ContactId contactId,
-			TransportId transportId,
-			DuplexTransportConnection connection) {
 		super(keyManager, connectionRegistry, streamReaderFactory,
 				streamWriterFactory, syncSessionFactory,
 				transportPropertyManager, ioExecutor, transportId, connection);
 		this.secureRandom = secureRandom;
-		this.handshakeManager = handshakeManager;
 		this.contactId = contactId;
 	}
 
 	@Override
 	public void run() {
-		LOG.info("Running OutgoingDuplexSyncConnection on transport " +
-				transportId.getString());
 		// Allocate a stream context
 		StreamContext ctx = allocateStreamContext(contactId, transportId);
 		if (ctx == null) {
@@ -71,22 +56,10 @@ class OutgoingDuplexSyncConnection extends DuplexSyncConnection
 			return;
 		}
 		if (ctx.isHandshakeMode()) {
-			if (!performHandshake(ctx)) {
+			// TODO: Support handshake mode for contacts
-				LOG.warning("Handshake failed");
+			LOG.warning("Cannot use handshake mode stream context");
-				return;
+			onWriteError();
-			}
+			return;
-			// Allocate a rotation mode stream context
-			ctx = allocateStreamContext(contactId, transportId);
-			if (ctx == null) {
-				LOG.warning("Could not allocate stream context");
-				onWriteError();
-				return;
-			}
-			if (ctx.isHandshakeMode()) {
-				LOG.warning("Got handshake mode context after handshaking");
-				onWriteError();
-				return;
-			}
 		}
 		// Start the incoming session on another thread
 		Priority priority = generatePriority();
@@ -154,59 +127,6 @@ class OutgoingDuplexSyncConnection extends DuplexSyncConnection
 		}
 	}
 
-	private boolean performHandshake(StreamContext ctxOut) {
-		LOG.info("Performing handshake (Outgoing)");
-		// Flush the output stream to send the outgoing stream header
-		StreamWriter out;
-		try {
-			out = streamWriterFactory.createStreamWriter(
-					writer.getOutputStream(), ctxOut);
-			out.getOutputStream().flush();
-		} catch (IOException e) {
-			logException(LOG, WARNING, e);
-			onWriteError();
-			return false;
-		}
-		// Read and recognise the tag
-		StreamContext ctxIn = recogniseTag(reader, transportId);
-		// Unrecognised tags are suspicious in this case
-		if (ctxIn == null) {
-			LOG.warning("Unrecognised tag for returning stream");
-			onReadError();
-			return false;
-		}
-		// Check that the stream comes from the expected contact
-		ContactId inContactId = ctxIn.getContactId();
-		if (contactId == null) {
-			LOG.warning("Expected contact tag, got rendezvous tag");
-			onReadError();
-			return false;
-		}
-		if (!inContactId.equals(contactId)) {
-			LOG.warning("Wrong contact ID for returning stream");
-			onReadError();
-			return false;
-		}
-		// TODO: Register the connection, close it if it's redundant
-		// Handshake and exchange contacts
-		try {
-			InputStream in = streamReaderFactory.createStreamReader(
-					reader.getInputStream(), ctxIn);
-			HandshakeManager.HandshakeResult result =
-					handshakeManager.handshake(contactId, in, out);
-			keyManager.addRotationKeys(contactId, result.getMasterKey(),
-					TIMESTAMP, result.isAlice(), true);
-			LOG.info("Rotation keys added");
-			return true;
-		} catch (IOException | DbException e) {
-			logException(LOG, WARNING, e);
-			onWriteError();
-			return false;
-		} finally {
-			// TODO: Unregister the connection
-		}
-	}
-
 	private void onReadError() {
 		// 'Recognised' is always true for outgoing connections
 		onReadError(true);

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

@@ -1,6 +1,6 @@
-package org.briarproject.bramble.api.contact;
+package org.briarproject.bramble.contact;
 
-public interface ContactExchangeConstants {
+interface ContactExchangeConstants {
 
 	/**
 	 * The current version of the contact exchange protocol.

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

@@ -1,4 +1,4 @@
-package org.briarproject.bramble.api.contact;
+package org.briarproject.bramble.contact;
 
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
@@ -6,7 +6,7 @@ import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 @NotNullByDefault
-public interface ContactExchangeCrypto {
+interface ContactExchangeCrypto {
 
 	/**
 	 * Derives the header key for a contact exchange stream from the master key.

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.contact;
 
-import org.briarproject.bramble.api.contact.ContactExchangeCrypto;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
@@ -11,12 +10,12 @@ import java.security.GeneralSecurityException;
 
 import javax.inject.Inject;
 
-import static org.briarproject.bramble.api.contact.ContactExchangeConstants.ALICE_KEY_LABEL;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.ALICE_KEY_LABEL;
-import static org.briarproject.bramble.api.contact.ContactExchangeConstants.ALICE_NONCE_LABEL;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.ALICE_NONCE_LABEL;
-import static org.briarproject.bramble.api.contact.ContactExchangeConstants.BOB_KEY_LABEL;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.BOB_KEY_LABEL;
-import static org.briarproject.bramble.api.contact.ContactExchangeConstants.BOB_NONCE_LABEL;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.BOB_NONCE_LABEL;
-import static org.briarproject.bramble.api.contact.ContactExchangeConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.PROTOCOL_VERSION;
-import static org.briarproject.bramble.api.contact.ContactExchangeConstants.SIGNING_LABEL;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.SIGNING_LABEL;
 
 @NotNullByDefault
 class ContactExchangeCryptoImpl implements ContactExchangeCrypto {

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

@@ -4,7 +4,6 @@ import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.Predicate;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.contact.Contact;
-import org.briarproject.bramble.api.contact.ContactExchangeCrypto;
 import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
@@ -48,8 +47,8 @@ import javax.inject.Inject;
 
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_SIGNATURE_LENGTH;
-import static org.briarproject.bramble.api.contact.ContactExchangeConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.contact.ContactExchangeConstants.PROTOCOL_VERSION;
-import static org.briarproject.bramble.api.contact.ContactExchangeRecordTypes.CONTACT_INFO;
+import static org.briarproject.bramble.contact.ContactExchangeRecordTypes.CONTACT_INFO;
 import static org.briarproject.bramble.util.ValidationUtils.checkLength;
 import static org.briarproject.bramble.util.ValidationUtils.checkSize;
 
@@ -82,8 +81,7 @@ class ContactExchangeManagerImpl implements ContactExchangeManager {
 	private final ContactManager contactManager;
 	private final IdentityManager identityManager;
 	private final TransportPropertyManager transportPropertyManager;
-	private final org.briarproject.bramble.api.contact.ContactExchangeCrypto
+	private final ContactExchangeCrypto contactExchangeCrypto;
-			contactExchangeCrypto;
 	private final StreamReaderFactory streamReaderFactory;
 	private final StreamWriterFactory streamWriterFactory;
 

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

@@ -0,0 +1,9 @@
+package org.briarproject.bramble.contact;
+
+/**
+ * Record types for the contact exchange protocol.
+ */
+interface ContactExchangeRecordTypes {
+
+	byte CONTACT_INFO = 0;
+}

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

@@ -9,7 +9,6 @@ import org.briarproject.bramble.api.contact.PendingContact;
 import org.briarproject.bramble.api.contact.PendingContactId;
 import org.briarproject.bramble.api.contact.PendingContactState;
 import org.briarproject.bramble.api.contact.event.PendingContactStateChangedEvent;
-import org.briarproject.bramble.api.crypto.CryptoConstants;
 import org.briarproject.bramble.api.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.crypto.SecretKey;
@@ -21,7 +20,9 @@ import org.briarproject.bramble.api.event.Event;
 import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.Author;
 import org.briarproject.bramble.api.identity.AuthorId;
+import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.identity.LocalAuthor;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.transport.KeyManager;
 
@@ -39,6 +40,10 @@ import javax.inject.Inject;
 
 import static org.briarproject.bramble.api.contact.PendingContactState.WAITING_FOR_CONNECTION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
+import static org.briarproject.bramble.api.identity.AuthorInfo.Status.OURSELVES;
+import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNKNOWN;
+import static org.briarproject.bramble.api.identity.AuthorInfo.Status.UNVERIFIED;
+import static org.briarproject.bramble.api.identity.AuthorInfo.Status.VERIFIED;
 import static org.briarproject.bramble.util.StringUtils.toUtf8;
 
 @ThreadSafe
@@ -120,18 +125,6 @@ class ContactManagerImpl implements ContactManager, EventListener {
 						verified, active));
 	}
 
-	@Override
-	public ContactId addContact(Transaction txn, Author remote, AuthorId local,
-			PublicKey handshake, boolean verified)
-			throws DbException, GeneralSecurityException {
-		ContactId c = db.addContact(txn, remote, local, handshake, verified);
-		Contact contact = db.getContact(txn, c);
-		KeyPair ourKeyPair = identityManager.getHandshakeKeys(txn);
-		keyManager.addContact(txn, c, handshake, ourKeyPair);
-		for (ContactHook hook : hooks) hook.addingContact(txn, contact);
-		return c;
-	}
-
 	@Override
 	public String getHandshakeLink() throws DbException {
 		KeyPair keyPair = db.transactionWithResult(true,
@@ -220,11 +213,6 @@ class ContactManagerImpl implements ContactManager, EventListener {
 		return db.transactionWithResult(true, db::getContacts);
 	}
 
-	@Override
-	public Collection<Contact> getContacts(Transaction txn) throws DbException {
-		return db.getContacts(txn);
-	}
-
 	@Override
 	public void removeContact(ContactId c) throws DbException {
 		db.transaction(false, txn -> removeContact(txn, c));
@@ -247,25 +235,6 @@ class ContactManagerImpl implements ContactManager, EventListener {
 		db.transaction(false, txn -> setContactAlias(txn, c, alias));
 	}
 
-	@Override
-	public void setHandshakePublicKey(Transaction txn, ContactId c,
-			PublicKey handshakePublicKey) throws DbException, GeneralSecurityException {
-		if (handshakePublicKey.getKeyType() !=
-				CryptoConstants.KEY_TYPE_AGREEMENT) {
-			throw new IllegalArgumentException();
-		}
-		db.setHandshakePublicKey(txn, c, handshakePublicKey);
-		KeyPair ourKeyPair = identityManager.getHandshakeKeys(txn);
-		keyManager.addContact(txn, c, handshakePublicKey, ourKeyPair);
-	}
-
-	@Override
-	public void setHandshakePublicKey(ContactId c, PublicKey handshakePublicKey)
-			throws DbException, GeneralSecurityException {
-		db.transaction(false,
-				txn -> setHandshakePublicKey(txn, c, handshakePublicKey));
-	}
-
 	@Override
 	public boolean contactExists(Transaction txn, AuthorId remoteAuthorId,
 			AuthorId localAuthorId) throws DbException {
@@ -287,6 +256,25 @@ class ContactManagerImpl implements ContactManager, EventListener {
 		db.removeContact(txn, c);
 	}
 
+	@Override
+	public AuthorInfo getAuthorInfo(AuthorId a) throws DbException {
+		return db.transactionWithResult(true, txn -> getAuthorInfo(txn, a));
+	}
+
+	@Override
+	public AuthorInfo getAuthorInfo(Transaction txn, AuthorId authorId)
+			throws DbException {
+		LocalAuthor localAuthor = identityManager.getLocalAuthor(txn);
+		if (localAuthor.getId().equals(authorId))
+			return new AuthorInfo(OURSELVES);
+		Collection<Contact> contacts = db.getContactsByAuthorId(txn, authorId);
+		if (contacts.isEmpty()) return new AuthorInfo(UNKNOWN);
+		if (contacts.size() > 1) throw new AssertionError();
+		Contact c = contacts.iterator().next();
+		if (c.isVerified()) return new AuthorInfo(VERIFIED, c.getAlias());
+		else return new AuthorInfo(UNVERIFIED, c.getAlias());
+	}
+
 	@Override
 	public void eventOccurred(Event e) {
 		if (e instanceof PendingContactStateChangedEvent) {

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.contact;
 
-import org.briarproject.bramble.api.contact.ContactExchangeCrypto;
 import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.contact.HandshakeManager;

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

@@ -3,8 +3,6 @@ package org.briarproject.bramble.contact;
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.Pair;
 import org.briarproject.bramble.api.Predicate;
-import org.briarproject.bramble.api.contact.Contact;
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.contact.HandshakeManager;
 import org.briarproject.bramble.api.contact.PendingContact;
@@ -90,27 +88,6 @@ class HandshakeManagerImpl implements HandshakeManager {
 		});
 		PublicKey theirStaticPublicKey = keys.getFirst();
 		KeyPair ourStaticKeyPair = keys.getSecond();
-		return handshake(theirStaticPublicKey, ourStaticKeyPair, in, out);
-	}
-
-	@Override
-	public HandshakeResult handshake(ContactId c, InputStream in,
-			StreamWriter out) throws DbException, IOException {
-		Pair<PublicKey, KeyPair> keys = db.transactionWithResult(true, txn -> {
-			Contact contact = contactManager.getContact(txn, c);
-			PublicKey handshakePublicKey = contact.getHandshakePublicKey();
-			if (handshakePublicKey == null) throw new DbException();
-			KeyPair keyPair = identityManager.getHandshakeKeys(txn);
-			return new Pair<>(handshakePublicKey, keyPair);
-		});
-		PublicKey theirStaticPublicKey = keys.getFirst();
-		KeyPair ourStaticKeyPair = keys.getSecond();
-		return handshake(theirStaticPublicKey, ourStaticKeyPair, in, out);
-	}
-
-	private HandshakeResult handshake(PublicKey theirStaticPublicKey,
-			KeyPair ourStaticKeyPair, InputStream in, StreamWriter out)
-			throws IOException {
 		boolean alice = transportCrypto.isAlice(theirStaticPublicKey,
 				ourStaticKeyPair);
 		RecordReader recordReader = recordReaderFactory.createRecordReader(in);

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

@@ -11,7 +11,6 @@ import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.Base32;
 
 import java.security.GeneralSecurityException;
-import java.util.Locale;
 import java.util.regex.Matcher;
 
 import javax.inject.Inject;
@@ -53,7 +52,7 @@ class PendingContactFactoryImpl implements PendingContactFactory {
 		byte[] raw = new byte[RAW_LINK_BYTES];
 		raw[0] = FORMAT_VERSION;
 		arraycopy(encoded, 0, raw, 1, encoded.length);
-		return "briar://" + Base32.encode(raw).toLowerCase(Locale.US);
+		return "briar://" + Base32.encode(raw).toLowerCase();
 	}
 
 	private PublicKey parseHandshakeLink(String link) throws FormatException {

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

@@ -1,11 +1,12 @@
-package org.briarproject.bramble.api.crypto;
+package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import java.security.GeneralSecurityException;
 
 @NotNullByDefault
-public interface AuthenticatedCipher {
+interface AuthenticatedCipher {
 
 	/**
 	 * Initializes this cipher for encryption or decryption with a key and an

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

@@ -6,7 +6,6 @@ import net.i2p.crypto.eddsa.KeyPairGenerator;
 
 import org.briarproject.bramble.api.crypto.AgreementPrivateKey;
 import org.briarproject.bramble.api.crypto.AgreementPublicKey;
-import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.DecryptionException;
 import org.briarproject.bramble.api.crypto.KeyPair;
@@ -21,9 +20,9 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.system.SecureRandomProvider;
 import org.briarproject.bramble.util.ByteUtils;
 import org.briarproject.bramble.util.StringUtils;
-import org.bouncycastle.crypto.CryptoException;
+import org.spongycastle.crypto.CryptoException;
-import org.bouncycastle.crypto.Digest;
+import org.spongycastle.crypto.Digest;
-import org.bouncycastle.crypto.digests.Blake2bDigest;
+import org.spongycastle.crypto.digests.Blake2bDigest;
 import org.whispersystems.curve25519.Curve25519;
 import org.whispersystems.curve25519.Curve25519KeyPair;
 

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.crypto;
 
-import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.KeyAgreementCrypto;
 import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;

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

@@ -6,33 +6,33 @@ import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.util.StringUtils;
-import org.bouncycastle.asn1.teletrust.TeleTrusTNamedCurves;
+import org.spongycastle.asn1.teletrust.TeleTrusTNamedCurves;
-import org.bouncycastle.asn1.x9.X9ECParameters;
+import org.spongycastle.asn1.x9.X9ECParameters;
-import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
+import org.spongycastle.crypto.AsymmetricCipherKeyPair;
-import org.bouncycastle.crypto.BasicAgreement;
+import org.spongycastle.crypto.BasicAgreement;
-import org.bouncycastle.crypto.BlockCipher;
+import org.spongycastle.crypto.BlockCipher;
-import org.bouncycastle.crypto.CipherParameters;
+import org.spongycastle.crypto.CipherParameters;
-import org.bouncycastle.crypto.CryptoException;
+import org.spongycastle.crypto.CryptoException;
-import org.bouncycastle.crypto.DerivationFunction;
+import org.spongycastle.crypto.DerivationFunction;
-import org.bouncycastle.crypto.KeyEncoder;
+import org.spongycastle.crypto.KeyEncoder;
-import org.bouncycastle.crypto.Mac;
+import org.spongycastle.crypto.Mac;
-import org.bouncycastle.crypto.agreement.ECDHCBasicAgreement;
+import org.spongycastle.crypto.agreement.ECDHCBasicAgreement;
-import org.bouncycastle.crypto.digests.SHA256Digest;
+import org.spongycastle.crypto.digests.SHA256Digest;
-import org.bouncycastle.crypto.engines.AESLightEngine;
+import org.spongycastle.crypto.engines.AESLightEngine;
-import org.bouncycastle.crypto.engines.IESEngine;
+import org.spongycastle.crypto.engines.IESEngine;
-import org.bouncycastle.crypto.generators.ECKeyPairGenerator;
+import org.spongycastle.crypto.generators.ECKeyPairGenerator;
-import org.bouncycastle.crypto.generators.EphemeralKeyPairGenerator;
+import org.spongycastle.crypto.generators.EphemeralKeyPairGenerator;
-import org.bouncycastle.crypto.generators.KDF2BytesGenerator;
+import org.spongycastle.crypto.generators.KDF2BytesGenerator;
-import org.bouncycastle.crypto.macs.HMac;
+import org.spongycastle.crypto.macs.HMac;
-import org.bouncycastle.crypto.modes.CBCBlockCipher;
+import org.spongycastle.crypto.modes.CBCBlockCipher;
-import org.bouncycastle.crypto.paddings.PaddedBufferedBlockCipher;
+import org.spongycastle.crypto.paddings.PaddedBufferedBlockCipher;
-import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
+import org.spongycastle.crypto.params.AsymmetricKeyParameter;
-import org.bouncycastle.crypto.params.ECDomainParameters;
+import org.spongycastle.crypto.params.ECDomainParameters;
-import org.bouncycastle.crypto.params.ECKeyGenerationParameters;
+import org.spongycastle.crypto.params.ECKeyGenerationParameters;
-import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
+import org.spongycastle.crypto.params.ECPrivateKeyParameters;
-import org.bouncycastle.crypto.params.ECPublicKeyParameters;
+import org.spongycastle.crypto.params.ECPublicKeyParameters;
-import org.bouncycastle.crypto.params.IESWithCipherParameters;
+import org.spongycastle.crypto.params.IESWithCipherParameters;
-import org.bouncycastle.crypto.parsers.ECIESPublicKeyParser;
+import org.spongycastle.crypto.parsers.ECIESPublicKeyParser;
 
 import java.io.FileInputStream;
 import java.io.FileOutputStream;

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

@@ -3,22 +3,20 @@ package org.briarproject.bramble.crypto;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.StringUtils;
-import org.bouncycastle.crypto.generators.SCrypt;
+import org.spongycastle.crypto.generators.SCrypt;
 
 import java.util.logging.Logger;
 
 import javax.inject.Inject;
 
-import static java.lang.Math.min;
 import static java.util.logging.Level.INFO;
-import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.now;
 
 class ScryptKdf implements PasswordBasedKdf {
 
 	private static final Logger LOG =
-			getLogger(ScryptKdf.class.getName());
+			Logger.getLogger(ScryptKdf.class.getName());
 
 	private static final int MIN_COST = 256; // Min parameter N
 	private static final int MAX_COST = 1024 * 1024; // Max parameter N
@@ -35,20 +33,10 @@ class ScryptKdf implements PasswordBasedKdf {
 
 	@Override
 	public int chooseCostParameter() {
-		// Scrypt uses at least 128 * N * r bytes of memory. Don't use more
-		// than half of the JVM's max heap size or we may run out of memory.
-		// https://blog.filippo.io/the-scrypt-parameters/
-		long maxMemory = Runtime.getRuntime().maxMemory();
-		long maxCost = min(MAX_COST, maxMemory / BLOCK_SIZE / 256);
-		if (LOG.isLoggable(INFO) && maxCost < MAX_COST) {
-			LOG.info("Max cost capped at " + maxCost
-					+ " due to max heap size " + maxMemory);
-		}
 		// Increase the cost from min to max while measuring performance
 		int cost = MIN_COST;
-		while (cost * 2 <= maxCost && measureDuration(cost) * 2 <= TARGET_MS) {
+		while (cost * 2 <= MAX_COST && measureDuration(cost) * 2 <= TARGET_MS)
 			cost *= 2;
-		}
 		if (LOG.isLoggable(INFO))
 			LOG.info("KDF cost parameter " + cost);
 		return cost;

bramble-core/src/main/java/org/briarproject/bramble/crypto/Sec1KeyParser.java

@@ -4,11 +4,11 @@ import org.briarproject.bramble.api.crypto.KeyParser;
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.bouncycastle.crypto.params.ECDomainParameters;
+import org.spongycastle.crypto.params.ECDomainParameters;
-import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
+import org.spongycastle.crypto.params.ECPrivateKeyParameters;
-import org.bouncycastle.crypto.params.ECPublicKeyParameters;
+import org.spongycastle.crypto.params.ECPublicKeyParameters;
-import org.bouncycastle.math.ec.ECCurve;
+import org.spongycastle.math.ec.ECCurve;
-import org.bouncycastle.math.ec.ECPoint;
+import org.spongycastle.math.ec.ECPoint;
 
 import java.math.BigInteger;
 import java.security.GeneralSecurityException;

bramble-core/src/main/java/org/briarproject/bramble/crypto/Sec1PrivateKey.java

@@ -2,7 +2,7 @@ package org.briarproject.bramble.crypto;
 
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.bouncycastle.crypto.params.ECPrivateKeyParameters;
+import org.spongycastle.crypto.params.ECPrivateKeyParameters;
 
 import javax.annotation.concurrent.Immutable;
 

bramble-core/src/main/java/org/briarproject/bramble/crypto/Sec1PublicKey.java

@@ -2,7 +2,7 @@ package org.briarproject.bramble.crypto;
 
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.bouncycastle.crypto.params.ECPublicKeyParameters;
+import org.spongycastle.crypto.params.ECPublicKeyParameters;
 
 import javax.annotation.concurrent.Immutable;
 

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.crypto;
 
-import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.StreamDecrypter;
 import org.briarproject.bramble.api.crypto.StreamDecrypterFactory;
@@ -37,10 +36,4 @@ class StreamDecrypterFactoryImpl implements StreamDecrypterFactory {
 			SecretKey headerKey) {
 		return new StreamDecrypterImpl(in, cipherProvider.get(), 0, headerKey);
 	}
-
-	@Override
-	public StreamDecrypter createLogStreamDecrypter(InputStream in,
-			SecretKey headerKey) {
-		return createContactExchangeStreamDecrypter(in, headerKey);
-	}
 }

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

@@ -1,7 +1,6 @@
 package org.briarproject.bramble.crypto;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.StreamDecrypter;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.crypto;
 
-import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.StreamEncrypter;
@@ -52,7 +51,7 @@ class StreamEncrypterFactoryImpl implements StreamEncrypterFactory {
 	}
 
 	@Override
-	public StreamEncrypter createContactExchangeStreamEncrypter(
+	public StreamEncrypter createContactExchangeStreamDecrypter(
 			OutputStream out, SecretKey headerKey) {
 		AuthenticatedCipher cipher = cipherProvider.get();
 		byte[] streamHeaderNonce = new byte[STREAM_HEADER_NONCE_LENGTH];
@@ -61,10 +60,4 @@ class StreamEncrypterFactoryImpl implements StreamEncrypterFactory {
 		return new StreamEncrypterImpl(out, cipher, 0, null, streamHeaderNonce,
 				headerKey, frameKey);
 	}
-
-	@Override
-	public StreamEncrypter createLogStreamEncrypter(OutputStream out,
-			SecretKey headerKey) {
-		return createContactExchangeStreamEncrypter(out, headerKey);
-	}
 }

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.crypto;
 
-import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.crypto.StreamEncrypter;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;

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

@@ -9,8 +9,8 @@ import org.briarproject.bramble.api.plugin.TransportId;
 import org.briarproject.bramble.api.transport.IncomingKeys;
 import org.briarproject.bramble.api.transport.OutgoingKeys;
 import org.briarproject.bramble.api.transport.TransportKeys;
-import org.bouncycastle.crypto.Digest;
+import org.spongycastle.crypto.Digest;
-import org.bouncycastle.crypto.digests.Blake2bDigest;
+import org.spongycastle.crypto.digests.Blake2bDigest;
 
 import java.security.GeneralSecurityException;
 

bramble-core/src/main/java/org/briarproject/bramble/crypto/XSalsa20Poly1305AuthenticatedCipher.java

@@ -1,14 +1,13 @@
 package org.briarproject.bramble.crypto;
 
-import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.bouncycastle.crypto.DataLengthException;
+import org.spongycastle.crypto.DataLengthException;
-import org.bouncycastle.crypto.engines.XSalsa20Engine;
+import org.spongycastle.crypto.engines.XSalsa20Engine;
-import org.bouncycastle.crypto.generators.Poly1305KeyGenerator;
+import org.spongycastle.crypto.generators.Poly1305KeyGenerator;
-import org.bouncycastle.crypto.macs.Poly1305;
+import org.spongycastle.crypto.macs.Poly1305;
-import org.bouncycastle.crypto.params.KeyParameter;
+import org.spongycastle.crypto.params.KeyParameter;
-import org.bouncycastle.crypto.params.ParametersWithIV;
+import org.spongycastle.crypto.params.ParametersWithIV;
 
 import java.security.GeneralSecurityException;
 

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

@@ -12,6 +12,7 @@ import org.briarproject.bramble.api.db.DataTooOldException;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.MessageDeletedException;
+import org.briarproject.bramble.api.db.MessageTooLargeException;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.identity.Author;
@@ -32,7 +33,6 @@ import org.briarproject.bramble.api.transport.KeySetId;
 import org.briarproject.bramble.api.transport.TransportKeySet;
 import org.briarproject.bramble.api.transport.TransportKeys;
 
-import java.sql.Connection;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
@@ -126,11 +126,6 @@ interface Database<T> {
 	void addMessageDependency(T txn, Message dependent, MessageId dependency,
 			MessageState dependentState) throws DbException;
 
-	/**
-	 * Records that a message has been offered by the given contact.
-	 */
-	void addOfferedMessage(T txn, ContactId c, MessageId m) throws DbException;
-
 	/**
 	 * Stores a pending contact.
 	 */
@@ -219,13 +214,6 @@ interface Database<T> {
 	boolean containsVisibleMessage(T txn, ContactId c, MessageId m)
 			throws DbException;
 
-	/**
-	 * Returns the number of messages offered by the given contact.
-	 * <p/>
-	 * Read-only.
-	 */
-	int countOfferedMessages(T txn, ContactId c) throws DbException;
-
 	/**
 	 * Deletes the message with the given ID. Unlike
 	 * {@link #removeMessage(Object, MessageId)}, the message ID and any other
@@ -333,13 +321,14 @@ interface Database<T> {
 	Collection<Identity> getIdentities(T txn) throws DbException;
 
 	/**
-	 * Returns the message with the given ID.
+	 * Returns the single-block message with the given ID.
 	 * <p/>
 	 * Read-only.
 	 *
 	 * @throws MessageDeletedException if the message has been deleted
+	 * @throws MessageTooLargeException if the message has more than one block
 	 */
-	Message getMessage(T txn, MessageId m) throws DbException;
+	Message getSmallMessage(T txn, MessageId m) throws DbException;
 
 	/**
 	 * Returns the IDs and states of all dependencies of the given message.
@@ -458,13 +447,13 @@ interface Database<T> {
 			int maxMessages, int maxLatency) throws DbException;
 
 	/**
-	 * Returns the IDs of some messages that are eligible to be requested from
+	 * Returns the IDs of some single-block messages that are eligible to be
-	 * the given contact, up to the given number of messages.
+	 * offered to the given contact, up to the given number of messages.
 	 * <p/>
 	 * Read-only.
 	 */
-	Collection<MessageId> getMessagesToRequest(T txn, ContactId c,
+	Collection<MessageId> getSmallMessagesToOffer(T txn, ContactId c,
-			int maxMessages) throws DbException;
+			int maxMessages, int maxLatency) throws DbException;
 
 	/**
 	 * Returns the IDs of some messages that are eligible to be sent to the
@@ -475,6 +464,15 @@ interface Database<T> {
 	Collection<MessageId> getMessagesToSend(T txn, ContactId c, int maxLength,
 			int maxLatency) throws DbException;
 
+	/**
+	 * Returns the IDs of some single-block messages that are eligible to be
+	 * sent to the given contact, up to the given total length.
+	 * <p/>
+	 * Read-only.
+	 */
+	Collection<MessageId> getSmallMessagesToSend(T txn, ContactId c,
+			int maxLength, int maxLatency) throws DbException;
+
 	/**
 	 * Returns the IDs of any messages that need to be validated.
 	 * <p/>
@@ -637,13 +635,6 @@ interface Database<T> {
 	 */
 	void removeMessage(T txn, MessageId m) throws DbException;
 
-	/**
-	 * Removes the given offered messages that were offered by the given
-	 * contact.
-	 */
-	void removeOfferedMessages(T txn, ContactId c,
-			Collection<MessageId> requested) throws DbException;
-
 	/**
 	 * Removes a pending contact (and all associated state) from the database.
 	 */
@@ -696,11 +687,6 @@ interface Database<T> {
 	void setHandshakeKeyPair(T txn, AuthorId local, PublicKey publicKey,
 			PrivateKey privateKey) throws DbException;
 
-	/**
-	 * Sets the handshake public key for a given contact
-	 */
-	void setHandshakePublicKey(T txn, ContactId c, PublicKey handshakePublicKey) throws DbException;
-
 	/**
 	 * Marks the given message as permanent, i.e. not temporary.
 	 */

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

@@ -61,10 +61,10 @@ import org.briarproject.bramble.api.sync.event.MessageAddedEvent;
 import org.briarproject.bramble.api.sync.event.MessageRequestedEvent;
 import org.briarproject.bramble.api.sync.event.MessageSharedEvent;
 import org.briarproject.bramble.api.sync.event.MessageStateChangedEvent;
-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.MessagesToAckEvent;
+import org.briarproject.bramble.api.sync.event.MessagesToRequestEvent;
 import org.briarproject.bramble.api.sync.event.SyncVersionsUpdatedEvent;
 import org.briarproject.bramble.api.sync.validation.MessageState;
 import org.briarproject.bramble.api.transport.KeySetId;
@@ -91,7 +91,6 @@ import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
 import static org.briarproject.bramble.api.sync.validation.MessageState.UNKNOWN;
-import static org.briarproject.bramble.db.DatabaseConstants.MAX_OFFERED_MESSAGES;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -406,19 +405,22 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	@Nullable
 	@Override
 	public Collection<Message> generateBatch(Transaction transaction,
-			ContactId c, int maxLength, int maxLatency) throws DbException {
+			ContactId c, int maxLength, int maxLatency, boolean small)
+			throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
-		Collection<MessageId> ids =
+		Collection<MessageId> ids;
-				db.getMessagesToSend(txn, c, maxLength, maxLatency);
+		if (small)
+			ids = db.getSmallMessagesToSend(txn, c, maxLength, maxLatency);
+		else ids = db.getMessagesToSend(txn, c, maxLength, maxLatency);
+		if (ids.isEmpty()) return null;
 		List<Message> messages = new ArrayList<>(ids.size());
 		for (MessageId m : ids) {
-			messages.add(db.getMessage(txn, m));
+			messages.add(db.getSmallMessage(txn, m));
 			db.updateExpiryTimeAndEta(txn, c, m, maxLatency);
 		}
-		if (ids.isEmpty()) return null;
 		db.lowerRequestedFlag(txn, c, ids);
 		transaction.attach(new MessagesSentEvent(c, ids));
 		return messages;
@@ -427,34 +429,21 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	@Nullable
 	@Override
 	public Offer generateOffer(Transaction transaction, ContactId c,
-			int maxMessages, int maxLatency) throws DbException {
+			int maxMessages, int maxLatency, boolean small) throws DbException {
 		if (transaction.isReadOnly()) throw new IllegalArgumentException();
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
-		Collection<MessageId> ids =
+		Collection<MessageId> ids;
-				db.getMessagesToOffer(txn, c, maxMessages, maxLatency);
+		if (small)
+			ids = db.getSmallMessagesToOffer(txn, c, maxMessages, maxLatency);
+		else ids = db.getMessagesToOffer(txn, c, maxMessages, maxLatency);
 		if (ids.isEmpty()) return null;
 		for (MessageId m : ids)
 			db.updateExpiryTimeAndEta(txn, c, m, maxLatency);
 		return new Offer(ids);
 	}
 
-	@Nullable
-	@Override
-	public Request generateRequest(Transaction transaction, ContactId c,
-			int maxMessages) throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		Collection<MessageId> ids = db.getMessagesToRequest(txn, c,
-				maxMessages);
-		if (ids.isEmpty()) return null;
-		db.removeOfferedMessages(txn, c, ids);
-		return new Request(ids);
-	}
-
 	@Nullable
 	@Override
 	public Collection<Message> generateRequestedBatch(Transaction transaction,
@@ -465,12 +454,12 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			throw new NoSuchContactException();
 		Collection<MessageId> ids =
 				db.getRequestedMessagesToSend(txn, c, maxLength, maxLatency);
+		if (ids.isEmpty()) return null;
 		List<Message> messages = new ArrayList<>(ids.size());
 		for (MessageId m : ids) {
-			messages.add(db.getMessage(txn, m));
+			messages.add(db.getSmallMessage(txn, m));
 			db.updateExpiryTimeAndEta(txn, c, m, maxLatency);
 		}
-		if (ids.isEmpty()) return null;
 		db.lowerRequestedFlag(txn, c, ids);
 		transaction.attach(new MessagesSentEvent(c, ids));
 		return messages;
@@ -559,12 +548,12 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 	}
 
 	@Override
-	public Message getMessage(Transaction transaction, MessageId m)
+	public Message getSmallMessage(Transaction transaction, MessageId m)
 			throws DbException {
 		T txn = unbox(transaction);
 		if (!db.containsMessage(txn, m))
 			throw new NoSuchMessageException();
-		return db.getMessage(txn, m);
+		return db.getSmallMessage(txn, m);
 	}
 
 	@Override
@@ -819,7 +808,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 				db.addMessage(txn, m, UNKNOWN, false, false, c);
 				transaction.attach(new MessageAddedEvent(m, c));
 			}
-			transaction.attach(new MessageToAckEvent(c));
+			transaction.attach(new MessagesToAckEvent(c));
 		}
 	}
 
@@ -830,21 +819,20 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		T txn = unbox(transaction);
 		if (!db.containsContact(txn, c))
 			throw new NoSuchContactException();
-		boolean ack = false, request = false;
+		boolean ack = false;
-		int count = db.countOfferedMessages(txn, c);
+		List<MessageId> request = new ArrayList<>(o.getMessageIds().size());
 		for (MessageId m : o.getMessageIds()) {
 			if (db.containsVisibleMessage(txn, c, m)) {
 				db.raiseSeenFlag(txn, c, m);
 				db.raiseAckFlag(txn, c, m);
 				ack = true;
-			} else if (count < MAX_OFFERED_MESSAGES) {
+			} else {
-				db.addOfferedMessage(txn, c, m);
+				request.add(m);
-				request = true;
-				count++;
 			}
 		}
-		if (ack) transaction.attach(new MessageToAckEvent(c));
+		if (ack) transaction.attach(new MessagesToAckEvent(c));
-		if (request) transaction.attach(new MessageToRequestEvent(c));
+		if (!request.isEmpty())
+			transaction.attach(new MessagesToRequestEvent(c, request));
 	}
 
 	@Override
@@ -1040,15 +1028,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		}
 	}
 
-	@Override
-	public void setHandshakePublicKey(Transaction transaction, ContactId c, PublicKey handshakePublicKey) throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsContact(txn, c))
-			throw new NoSuchContactException();
-		db.setHandshakePublicKey(txn, c, handshakePublicKey);
-	}
-
 	@Override
 	public void setHandshakeKeyPair(Transaction transaction, AuthorId local,
 			PublicKey publicKey, PrivateKey privateKey) throws DbException {

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

@@ -6,13 +6,6 @@ import static java.util.concurrent.TimeUnit.DAYS;
 
 interface DatabaseConstants {
 
-	/**
-	 * The maximum number of offered messages from each contact that will be
-	 * stored. If offers arrive more quickly than requests can be sent and this
-	 * limit is reached, additional offers will not be stored.
-	 */
-	int MAX_OFFERED_MESSAGES = 1000;
-
 	/**
 	 * The namespace of the {@link Settings} where the database schema version
 	 * is stored.

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

@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.event.EventExecutor;
 import org.briarproject.bramble.api.lifecycle.ShutdownManager;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 
 import java.sql.Connection;
@@ -22,9 +21,8 @@ public class DatabaseModule {
 
 	@Provides
 	@Singleton
-	Database<Connection> provideDatabase(DatabaseConfig config,
+	Database<Connection> provideDatabase(DatabaseConfig config, Clock clock) {
-			MessageFactory messageFactory, Clock clock) {
+		return new H2Database(config, clock);
-		return new H2Database(config, messageFactory, clock);
 	}
 
 	@Provides

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

@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.db.DbClosedException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.StringUtils;
 
@@ -51,9 +50,8 @@ class H2Database extends JdbcDatabase {
 	private volatile SecretKey key = null;
 
 	@Inject
-	H2Database(DatabaseConfig config, MessageFactory messageFactory,
+	H2Database(DatabaseConfig config, Clock clock) {
-			Clock clock) {
+		super(dbTypes, clock);
-		super(dbTypes, messageFactory, clock);
 		this.config = config;
 		File dir = config.getDatabaseDirectory();
 		String path = new File(dir, "db").getAbsolutePath();

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

@@ -6,7 +6,6 @@ import org.briarproject.bramble.api.db.DbClosedException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.util.StringUtils;
 
@@ -51,9 +50,8 @@ class HyperSqlDatabase extends JdbcDatabase {
 	private volatile SecretKey key = null;
 
 	@Inject
-	HyperSqlDatabase(DatabaseConfig config, MessageFactory messageFactory,
+	HyperSqlDatabase(DatabaseConfig config, Clock clock) {
-			Clock clock) {
+		super(dbTypes, clock);
-		super(dbTypes, messageFactory, clock);
 		this.config = config;
 		File dir = config.getDatabaseDirectory();
 		String path = new File(dir, "db").getAbsolutePath();

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

@@ -16,6 +16,7 @@ import org.briarproject.bramble.api.db.DataTooOldException;
 import org.briarproject.bramble.api.db.DbClosedException;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.db.MessageDeletedException;
+import org.briarproject.bramble.api.db.MessageTooLargeException;
 import org.briarproject.bramble.api.db.Metadata;
 import org.briarproject.bramble.api.db.MigrationListener;
 import org.briarproject.bramble.api.identity.Author;
@@ -30,7 +31,6 @@ import org.briarproject.bramble.api.sync.Group;
 import org.briarproject.bramble.api.sync.Group.Visibility;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.Message;
-import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.MessageStatus;
 import org.briarproject.bramble.api.sync.validation.MessageState;
@@ -76,6 +76,7 @@ import static org.briarproject.bramble.api.db.Metadata.REMOVE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_BLOCK_LENGTH;
 import static org.briarproject.bramble.api.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
 import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
 import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
@@ -98,7 +99,7 @@ import static org.briarproject.bramble.util.LogUtils.now;
 abstract class JdbcDatabase implements Database<Connection> {
 
 	// Package access for testing
-	static final int CODE_SCHEMA_VERSION = 47;
+	static final int CODE_SCHEMA_VERSION = 49;
 
 	// Time period offsets for incoming transport keys
 	private static final int OFFSET_PREV = -1;
@@ -180,8 +181,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " state INT NOT NULL,"
 					+ " shared BOOLEAN NOT NULL,"
 					+ " temporary BOOLEAN NOT NULL,"
-					+ " length INT NOT NULL,"
+					+ " length INT NOT NULL," // Includes message header
-					+ " raw BLOB," // Null if message has been deleted
+					+ " deleted BOOLEAN NOT NULL,"
+					+ " blockCount INT NOT NULL,"
 					+ " PRIMARY KEY (messageId),"
 					+ " FOREIGN KEY (groupId)"
 					+ " REFERENCES groups (groupId)"
@@ -218,13 +220,15 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " REFERENCES messages (messageId)"
 					+ " ON DELETE CASCADE)";
 
-	private static final String CREATE_OFFERS =
+	private static final String CREATE_BLOCKS =
-			"CREATE TABLE offers"
+			"CREATE TABLE blocks"
-					+ " (messageId _HASH NOT NULL," // Not a foreign key
+					+ " (messageId _HASH NOT NULL,"
-					+ " contactId INT NOT NULL,"
+					+ " blockNumber INT NOT NULL,"
-					+ " PRIMARY KEY (messageId, contactId),"
+					+ " blockLength INT NOT NULL," // Excludes block header
-					+ " FOREIGN KEY (contactId)"
+					+ " data BLOB," // Null if message has been deleted
-					+ " REFERENCES contacts (contactId)"
+					+ " PRIMARY KEY (messageId, blockNumber),"
+					+ " FOREIGN KEY (messageId)"
+					+ " REFERENCES messages (messageId)"
 					+ " ON DELETE CASCADE)";
 
 	private static final String CREATE_STATUSES =
@@ -339,7 +343,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 	private static final Logger LOG =
 			getLogger(JdbcDatabase.class.getName());
 
-	private final MessageFactory messageFactory;
 	private final Clock clock;
 	private final DatabaseTypes dbTypes;
 
@@ -359,10 +362,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 
 	protected abstract void compactAndClose() throws DbException;
 
-	JdbcDatabase(DatabaseTypes databaseTypes, MessageFactory messageFactory,
+	JdbcDatabase(DatabaseTypes databaseTypes, Clock clock) {
-			Clock clock) {
 		this.dbTypes = databaseTypes;
-		this.messageFactory = messageFactory;
 		this.clock = clock;
 	}
 
@@ -440,10 +441,12 @@ abstract class JdbcDatabase implements Database<Connection> {
 				if (LOG.isLoggable(INFO))
 					LOG.info("Migrating from schema " + start + " to " + end);
 				if (listener != null) listener.onDatabaseMigration();
+				long startTime = now();
 				// Apply the migration
 				m.migrate(txn);
 				// Store the new schema version
 				storeSchemaVersion(txn, end);
+				logDuration(LOG, "Migration", startTime);
 				dataSchemaVersion = end;
 			}
 		}
@@ -463,7 +466,9 @@ abstract class JdbcDatabase implements Database<Connection> {
 				new Migration43_44(dbTypes),
 				new Migration44_45(),
 				new Migration45_46(),
-				new Migration46_47(dbTypes)
+				new Migration46_47(dbTypes),
+				new Migration47_48(dbTypes),
+				new Migration48_49()
 		);
 	}
 
@@ -508,7 +513,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_MESSAGES));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_MESSAGE_METADATA));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_MESSAGE_DEPENDENCIES));
-			s.executeUpdate(dbTypes.replaceTypes(CREATE_OFFERS));
+			s.executeUpdate(dbTypes.replaceTypes(CREATE_BLOCKS));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_STATUSES));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_TRANSPORTS));
 			s.executeUpdate(dbTypes.replaceTypes(CREATE_PENDING_CONTACTS));
@@ -726,7 +731,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		ResultSet rs = null;
 		try {
 			String sql = "SELECT messageId, timestamp, state, shared,"
-					+ " length, raw IS NULL"
+					+ " length, deleted"
 					+ " FROM messages"
 					+ " WHERE groupId = ?";
 			ps = txn.prepareStatement(sql);
@@ -739,9 +744,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 				boolean messageShared = rs.getBoolean(4);
 				int length = rs.getInt(5);
 				boolean deleted = rs.getBoolean(6);
-				boolean seen = removeOfferedMessage(txn, c, id);
 				addStatus(txn, id, c, g, timestamp, length, state, groupShared,
-						messageShared, deleted, seen);
+						messageShared, deleted, false);
 			}
 			rs.close();
 			ps.close();
@@ -788,8 +792,8 @@ abstract class JdbcDatabase implements Database<Connection> {
 		PreparedStatement ps = null;
 		try {
 			String sql = "INSERT INTO messages (messageId, groupId, timestamp,"
-					+ " state, shared, temporary, length, raw)"
+					+ " state, shared, temporary, length, deleted, blockCount)"
-					+ " VALUES (?, ?, ?, ?, ?, ?, ?, ?)";
+					+ " VALUES (?, ?, ?, ?, ?, ?, ?, FALSE, 1)";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getId().getBytes());
 			ps.setBytes(2, m.getGroupId().getBytes());
@@ -797,21 +801,29 @@ abstract class JdbcDatabase implements Database<Connection> {
 			ps.setInt(4, state.getValue());
 			ps.setBoolean(5, shared);
 			ps.setBoolean(6, temporary);
-			byte[] raw = messageFactory.getRawMessage(m);
+			ps.setInt(7, m.getRawLength());
-			ps.setInt(7, raw.length);
-			ps.setBytes(8, raw);
 			int affected = ps.executeUpdate();
 			if (affected != 1) throw new DbStateException();
 			ps.close();
+			sql = "INSERT INTO blocks (messageId, blockNumber, blockLength,"
+					+ " data)"
+					+ " VALUES (?, 0, ?, ?)";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, m.getId().getBytes());
+			ps.setInt(2, m.getBody().length);
+			ps.setBytes(3, m.getBody());
+			affected = ps.executeUpdate();
+			if (affected != 1) throw new DbStateException();
+			ps.close();
 			// Create a status row for each contact that can see the group
 			Map<ContactId, Boolean> visibility =
 					getGroupVisibility(txn, m.getGroupId());
 			for (Entry<ContactId, Boolean> e : visibility.entrySet()) {
 				ContactId c = e.getKey();
-				boolean offered = removeOfferedMessage(txn, c, m.getId());
+				boolean seen = c.equals(sender);
-				boolean seen = offered || c.equals(sender);
 				addStatus(txn, m.getId(), c, m.getGroupId(), m.getTimestamp(),
-						raw.length, state, e.getValue(), shared, false, seen);
+						m.getRawLength(), state, e.getValue(), shared, false,
+						seen);
 			}
 			// Update denormalised column in messageDependencies if dependency
 			// is in same group as dependent
@@ -830,37 +842,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public void addOfferedMessage(Connection txn, ContactId c, MessageId m)
-			throws DbException {
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			String sql = "SELECT NULL FROM offers"
-					+ " WHERE messageId = ? AND contactId = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setBytes(1, m.getBytes());
-			ps.setInt(2, c.getInt());
-			rs = ps.executeQuery();
-			boolean found = rs.next();
-			if (rs.next()) throw new DbStateException();
-			rs.close();
-			ps.close();
-			if (found) return;
-			sql = "INSERT INTO offers (messageId, contactId) VALUES (?, ?)";
-			ps = txn.prepareStatement(sql);
-			ps.setBytes(1, m.getBytes());
-			ps.setInt(2, c.getInt());
-			int affected = ps.executeUpdate();
-			if (affected != 1) throw new DbStateException();
-			ps.close();
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	private void addStatus(Connection txn, MessageId m, ContactId c, GroupId g,
 			long timestamp, int length, MessageState state, boolean groupShared,
 			boolean messageShared, boolean deleted, boolean seen)
@@ -1262,40 +1243,22 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public int countOfferedMessages(Connection txn, ContactId c)
-			throws DbException {
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			String sql = "SELECT COUNT (messageId) FROM offers "
-					+ " WHERE contactId = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setInt(1, c.getInt());
-			rs = ps.executeQuery();
-			if (!rs.next()) throw new DbException();
-			int count = rs.getInt(1);
-			if (rs.next()) throw new DbException();
-			rs.close();
-			ps.close();
-			return count;
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public void deleteMessage(Connection txn, MessageId m) throws DbException {
 		PreparedStatement ps = null;
 		try {
-			String sql = "UPDATE messages SET raw = NULL WHERE messageId = ?";
+			String sql = "UPDATE messages SET deleted = TRUE"
+					+ " 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();
+			sql = "UPDATE blocks SET data = NULL WHERE messageId = ?";
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, m.getBytes());
+			affected = ps.executeUpdate();
 			if (affected < 0) throw new DbStateException();
-			if (affected > 1) throw new DbStateException();
 			ps.close();
 			// Update denormalised column in statuses
 			sql = "UPDATE statuses SET deleted = TRUE WHERE messageId = ?";
@@ -1688,11 +1651,13 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public Message getMessage(Connection txn, MessageId m) throws DbException {
+	public Message getSmallMessage(Connection txn, MessageId m)
+			throws DbException {
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT groupId, timestamp, raw FROM messages"
+			String sql = "SELECT groupId, timestamp, deleted, blockCount"
+					+ " FROM messages"
 					+ " WHERE messageId = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
@@ -1700,15 +1665,25 @@ abstract class JdbcDatabase implements Database<Connection> {
 			if (!rs.next()) throw new DbStateException();
 			GroupId g = new GroupId(rs.getBytes(1));
 			long timestamp = rs.getLong(2);
-			byte[] raw = rs.getBytes(3);
+			boolean deleted = rs.getBoolean(3);
+			int blockCount = rs.getInt(4);
 			if (rs.next()) throw new DbStateException();
 			rs.close();
 			ps.close();
-			if (raw == null) throw new MessageDeletedException();
+			if (deleted) throw new MessageDeletedException();
-			if (raw.length <= MESSAGE_HEADER_LENGTH) throw new AssertionError();
+			if (blockCount > 1) throw new MessageTooLargeException();
-			byte[] body = new byte[raw.length - MESSAGE_HEADER_LENGTH];
+			sql = "SELECT data FROM blocks"
-			System.arraycopy(raw, MESSAGE_HEADER_LENGTH, body, 0, body.length);
+					+ " WHERE messageId = ? AND blockNumber = 0";
-			return new Message(m, g, timestamp, body);
+			ps = txn.prepareStatement(sql);
+			ps.setBytes(1, m.getBytes());
+			rs = ps.executeQuery();
+			if (!rs.next()) throw new DbStateException();
+			byte[] data = rs.getBytes(1);
+			if (data == null) throw new DbStateException();
+			if (rs.next()) throw new DbStateException();
+			rs.close();
+			ps.close();
+			return new Message(m, g, timestamp, data);
 		} catch (SQLException e) {
 			tryToClose(rs, LOG, WARNING);
 			tryToClose(ps, LOG, WARNING);
@@ -2101,17 +2076,28 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public Collection<MessageId> getMessagesToRequest(Connection txn,
+	public Collection<MessageId> getSmallMessagesToOffer(Connection txn,
-			ContactId c, int maxMessages) throws DbException {
+			ContactId c, int maxMessages, int maxLatency) throws DbException {
+		long now = clock.currentTimeMillis();
+		long eta = now + maxLatency;
 		PreparedStatement ps = null;
 		ResultSet rs = null;
 		try {
-			String sql = "SELECT messageId FROM offers"
+			String sql = "SELECT messageId FROM statuses"
-					+ " WHERE contactId = ?"
+					+ " WHERE contactId = ? AND state = ?"
-					+ " LIMIT ?";
+					+ " AND length <= ?"
+					+ " AND groupShared = TRUE AND messageShared = TRUE"
+					+ " AND deleted = FALSE"
+					+ " AND seen = FALSE AND requested = FALSE"
+					+ " AND (expiry <= ? OR eta > ?)"
+					+ " ORDER BY timestamp LIMIT ?";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, c.getInt());
-			ps.setInt(2, maxMessages);
+			ps.setInt(2, DELIVERED.getValue());
+			ps.setInt(3, MESSAGE_HEADER_LENGTH + MAX_BLOCK_LENGTH);
+			ps.setLong(4, now);
+			ps.setLong(5, eta);
+			ps.setInt(6, maxMessages);
 			rs = ps.executeQuery();
 			List<MessageId> ids = new ArrayList<>();
 			while (rs.next()) ids.add(new MessageId(rs.getBytes(1)));
@@ -2164,6 +2150,47 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
+	@Override
+	public Collection<MessageId> getSmallMessagesToSend(Connection txn,
+			ContactId c, int maxLength, int maxLatency) throws DbException {
+		long now = clock.currentTimeMillis();
+		long eta = now + maxLatency;
+		PreparedStatement ps = null;
+		ResultSet rs = null;
+		try {
+			String sql = "SELECT length, messageId FROM statuses"
+					+ " WHERE contactId = ? AND state = ?"
+					+ " AND length <= ?"
+					+ " AND groupShared = TRUE AND messageShared = TRUE"
+					+ " AND deleted = FALSE"
+					+ " AND seen = FALSE"
+					+ " AND (expiry <= ? OR eta > ?)"
+					+ " ORDER BY timestamp";
+			ps = txn.prepareStatement(sql);
+			ps.setInt(1, c.getInt());
+			ps.setInt(2, DELIVERED.getValue());
+			ps.setInt(3, MESSAGE_HEADER_LENGTH + MAX_BLOCK_LENGTH);
+			ps.setLong(4, now);
+			ps.setLong(5, eta);
+			rs = ps.executeQuery();
+			List<MessageId> ids = new ArrayList<>();
+			int total = 0;
+			while (rs.next()) {
+				int length = rs.getInt(1);
+				if (total + length > maxLength) break;
+				ids.add(new MessageId(rs.getBytes(2)));
+				total += length;
+			}
+			rs.close();
+			ps.close();
+			return ids;
+		} catch (SQLException e) {
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(ps, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+
 	@Override
 	public Collection<MessageId> getMessagesToValidate(Connection txn)
 			throws DbException {
@@ -2182,7 +2209,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 		ResultSet rs = null;
 		try {
 			String sql = "SELECT messageId FROM messages"
-					+ " WHERE state = ? AND raw IS NOT NULL";
+					+ " WHERE state = ? AND deleted = FALSE";
 			ps = txn.prepareStatement(sql);
 			ps.setInt(1, state.getValue());
 			rs = ps.executeQuery();
@@ -2887,50 +2914,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	private boolean removeOfferedMessage(Connection txn, ContactId c,
-			MessageId m) throws DbException {
-		PreparedStatement ps = null;
-		try {
-			String sql = "DELETE FROM offers"
-					+ " WHERE contactId = ? AND messageId = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setInt(1, c.getInt());
-			ps.setBytes(2, m.getBytes());
-			int affected = ps.executeUpdate();
-			if (affected < 0 || affected > 1) throw new DbStateException();
-			ps.close();
-			return affected == 1;
-		} catch (SQLException e) {
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
-	@Override
-	public void removeOfferedMessages(Connection txn, ContactId c,
-			Collection<MessageId> requested) throws DbException {
-		PreparedStatement ps = null;
-		try {
-			String sql = "DELETE FROM offers"
-					+ " WHERE contactId = ? AND messageId = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setInt(1, c.getInt());
-			for (MessageId m : requested) {
-				ps.setBytes(2, m.getBytes());
-				ps.addBatch();
-			}
-			int[] batchAffected = ps.executeBatch();
-			if (batchAffected.length != requested.size())
-				throw new DbStateException();
-			for (int rows : batchAffected)
-				if (rows != 1) throw new DbStateException();
-			ps.close();
-		} catch (SQLException e) {
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public void removePendingContact(Connection txn, PendingContactId p)
 			throws DbException {
@@ -3058,23 +3041,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public void setHandshakePublicKey(Connection txn, ContactId c, PublicKey handshakePublicKey) throws DbException {
-		PreparedStatement ps = null;
-		try {
-			String sql = "UPDATE contacts SET handshakePublicKey = ? WHERE contactId = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setBytes(1, handshakePublicKey.getEncoded());
-			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 setGroupVisibility(Connection txn, ContactId c, GroupId g,
 			boolean shared) throws DbException {

bramble-core/src/main/java/org/briarproject/bramble/db/Migration38_39.java

@@ -37,6 +37,7 @@ class Migration38_39 implements Migration<Connection> {
 			s.execute("ALTER TABLE incomingKeys"
 					+ " ALTER COLUMN contactId"
 					+ " SET NOT NULL");
+			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);

bramble-core/src/main/java/org/briarproject/bramble/db/Migration39_40.java

@@ -36,6 +36,7 @@ class Migration39_40 implements Migration<Connection> {
 			s.execute("ALTER TABLE statuses"
 					+ " ALTER COLUMN eta"
 					+ " SET NOT NULL");
+			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);

bramble-core/src/main/java/org/briarproject/bramble/db/Migration40_41.java

@@ -38,6 +38,7 @@ class Migration40_41 implements Migration<Connection> {
 			s = txn.createStatement();
 			s.execute("ALTER TABLE contacts"
 					+ dbTypes.replaceTypes(" ADD alias _STRING"));
+			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);

bramble-core/src/main/java/org/briarproject/bramble/db/Migration41_42.java

@@ -89,6 +89,7 @@ class Migration41_42 implements Migration<Connection> {
 					+ " FOREIGN KEY (keySetId)"
 					+ " REFERENCES outgoingHandshakeKeys (keySetId)"
 					+ " ON DELETE CASCADE)"));
+			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);

bramble-core/src/main/java/org/briarproject/bramble/db/Migration42_43.java

@@ -44,6 +44,7 @@ class Migration42_43 implements Migration<Connection> {
 					+ " ADD COLUMN handshakePublicKey _BINARY"));
 			s.execute("ALTER TABLE contacts"
 					+ " DROP COLUMN active");
+			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);

bramble-core/src/main/java/org/briarproject/bramble/db/Migration43_44.java

@@ -50,6 +50,7 @@ class Migration43_44 implements Migration<Connection> {
 					+ " ADD COLUMN rootKey _SECRET"));
 			s.execute("ALTER TABLE outgoingKeys"
 					+ " ADD COLUMN alice BOOLEAN");
+			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);

bramble-core/src/main/java/org/briarproject/bramble/db/Migration44_45.java

@@ -31,6 +31,7 @@ class Migration44_45 implements Migration<Connection> {
 		try {
 			s = txn.createStatement();
 			s.execute("ALTER TABLE pendingContacts DROP COLUMN state");
+			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);

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

@@ -32,6 +32,7 @@ class Migration45_46 implements Migration<Connection> {
 			s = txn.createStatement();
 			s.execute("ALTER TABLE messages"
 					+ " ADD COLUMN temporary BOOLEAN DEFAULT FALSE NOT NULL");
+			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);

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

@@ -39,6 +39,7 @@ class Migration46_47 implements Migration<Connection> {
 			s.execute(dbTypes.replaceTypes("ALTER TABLE contacts"
 					+ " ADD COLUMN syncVersions"
 					+ " _BINARY DEFAULT '00' NOT NULL"));
+			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
 			throw new DbException(e);

bramble-core/src/main/java/org/briarproject/bramble/db/Migration47_48.java

@@ -0,0 +1,95 @@
+package org.briarproject.bramble.db;
+
+import org.briarproject.bramble.api.db.DbException;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.logging.Logger;
+
+import static java.lang.System.arraycopy;
+import static java.sql.Types.BINARY;
+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.sync.SyncConstants.MESSAGE_HEADER_LENGTH;
+import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
+
+class Migration47_48 implements Migration<Connection> {
+
+	private static final Logger LOG = getLogger(Migration47_48.class.getName());
+
+	private final DatabaseTypes dbTypes;
+
+	Migration47_48(DatabaseTypes dbTypes) {
+		this.dbTypes = dbTypes;
+	}
+
+	@Override
+	public int getStartVersion() {
+		return 47;
+	}
+
+	@Override
+	public int getEndVersion() {
+		return 48;
+	}
+
+	@Override
+	public void migrate(Connection txn) throws DbException {
+		Statement s = null;
+		ResultSet rs = null;
+		PreparedStatement ps = null;
+		try {
+			s = txn.createStatement();
+			s.execute("ALTER TABLE messages"
+					+ " ADD COLUMN deleted BOOLEAN DEFAULT FALSE NOT NULL");
+			s.execute("UPDATE messages SET deleted = TRUE WHERE raw IS NULL");
+			s.execute("ALTER TABLE messages"
+					+ " ADD COLUMN blockCount INT DEFAULT 1 NOT NULL");
+			s.execute(dbTypes.replaceTypes("CREATE TABLE blocks"
+					+ " (messageId _HASH NOT NULL,"
+					+ " blockNumber INT NOT NULL,"
+					+ " blockLength INT NOT NULL," // Excludes block header
+					+ " data BLOB," // Null if message has been deleted
+					+ " PRIMARY KEY (messageId, blockNumber),"
+					+ " FOREIGN KEY (messageId)"
+					+ " REFERENCES messages (messageId)"
+					+ " ON DELETE CASCADE)"));
+			rs = s.executeQuery("SELECT messageId, length, raw FROM messages");
+			ps = txn.prepareStatement("INSERT INTO blocks"
+					+ " (messageId, blockNumber, blockLength, data)"
+					+ " VALUES (?, 0, ?, ?)");
+			int migrated = 0;
+			while (rs.next()) {
+				byte[] id = rs.getBytes(1);
+				int length = rs.getInt(2);
+				byte[] raw = rs.getBytes(3);
+				ps.setBytes(1, id);
+				ps.setInt(2, length - MESSAGE_HEADER_LENGTH);
+				if (raw == null) {
+					ps.setNull(3, BINARY);
+				} else {
+					byte[] data = new byte[raw.length - MESSAGE_HEADER_LENGTH];
+					arraycopy(raw, MESSAGE_HEADER_LENGTH, data, 0, data.length);
+					ps.setBytes(3, data);
+				}
+				if (ps.executeUpdate() != 1) throw new DbStateException();
+				migrated++;
+			}
+			ps.close();
+			rs.close();
+			s.execute("ALTER TABLE messages DROP COLUMN raw");
+			s.close();
+			if (LOG.isLoggable(INFO))
+				LOG.info("Migrated " + migrated + " messages");
+		} catch (SQLException e) {
+			tryToClose(ps, LOG, WARNING);
+			tryToClose(rs, LOG, WARNING);
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/db/Migration48_49.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 Migration48_49 implements Migration<Connection> {
+
+	private static final Logger LOG = getLogger(Migration48_49.class.getName());
+
+	@Override
+	public int getStartVersion() {
+		return 48;
+	}
+
+	@Override
+	public int getEndVersion() {
+		return 49;
+	}
+
+	@Override
+	public void migrate(Connection txn) throws DbException {
+		Statement s = null;
+		try {
+			s = txn.createStatement();
+			s.execute("DROP TABLE offers");
+			s.close();
+		} catch (SQLException e) {
+			tryToClose(s, LOG, WARNING);
+			throw new DbException(e);
+		}
+	}
+}

bramble-core/src/main/java/org/briarproject/bramble/identity/IdentityManagerImpl.java

@@ -118,11 +118,6 @@ class IdentityManagerImpl implements IdentityManager, OpenDatabaseHook {
 		return cached.getLocalAuthor();
 	}
 
-	@Override
-	public Identity getIdentity(Transaction txn) throws DbException {
-		return getCachedIdentity(txn);
-	}
-
 	@Override
 	public LocalAuthor getLocalAuthor(Transaction txn) throws DbException {
 		return getCachedIdentity(txn).getLocalAuthor();