Add logging on replacing outgoing transport keys

* social-backup-poc:
  Rm test which was not present in this branch before cherry pick
  Resolve conflict on cherry pick commit to use ByteBuddyClassImposteriser
  Tell animal sniffer gradle plugin to ignore java.util.Objects
  Improve lost password and setup password dialog for social backup
  When creating social backup, only allow selecting contacts when there are at least 2 contacts in contact list
  Disable help recover account option by default

.idea/codeStyles/Project.xml

@@ -31,15 +31,6 @@
       <option name="PACKAGES_TO_USE_STAR_IMPORTS">
         <value />
       </option>
-      <option name="PACKAGES_IMPORT_LAYOUT">
-        <value>
-          <package name="" alias="false" withSubpackages="true" />
-          <package name="java" alias="false" withSubpackages="true" />
-          <package name="javax" alias="false" withSubpackages="true" />
-          <package name="kotlin" alias="false" withSubpackages="true" />
-          <package name="" alias="true" withSubpackages="true" />
-        </value>
-      </option>
       <option name="NAME_COUNT_TO_USE_STAR_IMPORT" value="2147483647" />
       <option name="NAME_COUNT_TO_USE_STAR_IMPORT_FOR_MEMBERS" value="2147483647" />
       <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />

.idea/dictionaries/briar.xml

@@ -7,7 +7,6 @@
       <w>encrypter</w>
       <w>identicon</w>
       <w>introducee</w>
-      <w>introducees</w>
       <w>introducer</w>
       <w>onboarding</w>
     </words>

bramble-android/build.gradle

@@ -8,11 +8,15 @@ android {
 	compileSdkVersion 30
 	buildToolsVersion '30.0.2'
 
+	packagingOptions {
+		doNotStrip '**/*.so'
+	}
+
 	defaultConfig {
 		minSdkVersion 16
 		targetSdkVersion 29
-		versionCode 10216
-		versionName "1.2.16"
+		versionCode 10218
+		versionName "1.2.18"
 		consumerProguardFiles 'proguard-rules.txt'
 
 		testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
@@ -46,10 +50,10 @@ dependencies {
 	compileOnly 'javax.annotation:jsr250-api:1.0'
 
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
-	testImplementation 'junit:junit:4.12'
-	testImplementation "org.jmock:jmock:2.8.2"
-	testImplementation "org.jmock:jmock-junit4:2.8.2"
-	testImplementation "org.jmock:jmock-legacy:2.8.2"
+	testImplementation "junit:junit:$junit_version"
+	testImplementation "org.jmock:jmock:$jmock_version"
+	testImplementation "org.jmock:jmock-junit4:$jmock_version"
+	testImplementation "org.jmock:jmock-imposters:$jmock_version"
 }
 
 def torBinariesDir = 'src/main/res/raw'

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

@@ -175,6 +175,11 @@ 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/util/AndroidUtils.java

@@ -114,12 +114,8 @@ public class AndroidUtils {
 
 	/**
 	 * Returns an array of supported content types for image attachments.
-	 * GIFs can't be compressed on API < 24 so they're not supported.
-	 * <p>
-	 * TODO: Remove this restriction when large message support is added
 	 */
 	public static String[] getSupportedImageContentTypes() {
-		if (SDK_INT < 24) return new String[] {"image/jpeg", "image/png"};
-		else return new String[] {"image/jpeg", "image/png", "image/gif"};
+		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.lib.legacy.ClassImposteriser;
+import org.jmock.imposters.ByteBuddyClassImposteriser;
 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(ClassImposteriser.INSTANCE);
+		context.setImposteriser(ByteBuddyClassImposteriser.INSTANCE);
 		app = context.mock(Application.class);
 		applicationInfo = new ApplicationInfo();
 		applicationInfo.dataDir = testDir.getAbsolutePath();

bramble-android/witness.gradle

@@ -1,6 +1,6 @@
 dependencyVerification {
     verify = [
-        'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+        'cglib:cglib:3.2.8:cglib-3.2.8.jar:3f64de999ecc5595dc84ca8ff0879d8a34c8623f9ef3c517a53ed59023fcb9db',
         'com.android.tools.analytics-library:protos:27.1.1:protos-27.1.1.jar:13f77e73762e58ab372d140b3a6be6903aea9775b62dd14fbc62d4cc7069c9a4',
         'com.android.tools.analytics-library:shared:27.1.1:shared-27.1.1.jar:82930a52001410e97d809930b670f4de3002286975f046b9de5f6b777b06d366',
         'com.android.tools.analytics-library:tracker:27.1.1:tracker-27.1.1.jar:31bc5a00be0055bac89c9b2f34751883e987cd89e3ac1783720645c164f591d9',
@@ -31,6 +31,7 @@ dependencyVerification {
         'com.android.tools:sdklib:27.1.1:sdklib-27.1.1.jar:08e6b83961ac9724b3c1e3d0eff971f13be6701292c77914b8794480f3391250',
         'com.android:signflinger:4.1.1:signflinger-4.1.1.jar:0c66825988873ec2d51057fa463f54a8f18fc7326ff4530b9da363b71e97ce60',
         'com.android:zipflinger:4.1.1:zipflinger-4.1.1.jar:0a8c3e52ac13dd031236f9fb5ba4408b1d5dcd12325a05440b36da09d8881446',
+        '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:2.8.5:gson-2.8.5.jar:233a0149fc365c9f6edbd683cfe266b19bdc773be98eabdaf6b3c924b48e7d81',
         'com.google.dagger:dagger-compiler:2.24:dagger-compiler-2.24.jar:3c5afb955fb188da485cb2c048eff37dce0e1530b9780a0f2f7187d16d1ccc1f',
@@ -63,16 +64,16 @@ dependencyVerification {
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'javax.xml.bind:jaxb-api:2.3.1:jaxb-api-2.3.1.jar:88b955a0df57880a26a74708bc34f74dcaf8ebf4e78843a28b50eae945732b06',
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
+        'net.bytebuddy:byte-buddy:1.9.12:byte-buddy-1.9.12.jar:3688c3d434bebc3edc5516296a2ed0f47b65e451071b4afecad84f902f0efc11',
+        '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.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-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
         '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',
@@ -85,8 +86,9 @@ dependencyVerification {
         'org.codehaus.mojo:animal-sniffer-annotations:1.18:animal-sniffer-annotations-1.18.jar:47f05852b48ee9baefef80fa3d8cea60efa4753c0013121dd7fe5eef2e5c729d',
         'org.glassfish.jaxb:jaxb-runtime:2.3.1:jaxb-runtime-2.3.1.jar:45fecfa5c8217ce1f3652ab95179790ec8cc0dec0384bca51cbeb94a293d9f2f',
         'org.glassfish.jaxb:txw2:2.3.1:txw2-2.3.1.jar:34975dde1c6920f1a39791142235689bc3cd357e24d05edd8ff93b885bd68d60',
-        'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
-        'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
+        'org.hamcrest:hamcrest-core:2.1:hamcrest-core-2.1.jar:e09109e54a289d88506b9bfec987ddd199f4217c9464132668351b9a4f00bee9',
+        'org.hamcrest:hamcrest-library:2.1:hamcrest-library-2.1.jar:b7e2b6895b3b679f0e47b6380fda391b225e9b78505db9d8bdde8d3cc8d52a21',
+        'org.hamcrest:hamcrest:2.1:hamcrest-2.1.jar:ba93b2e3a562322ba432f0a1b53addcc55cb188253319a020ed77f824e692050',
         'org.jetbrains.kotlin:kotlin-reflect:1.3.72:kotlin-reflect-1.3.72.jar:a188d9367de1c4ee9479db630985c0597b20709c83161b1430d24edb27e38c40',
         'org.jetbrains.kotlin:kotlin-stdlib-common:1.3.72:kotlin-stdlib-common-1.3.72.jar:5e7d1552863e480c1628b1cc39ce230ef829f5b7230106215a05acda5172203a',
         'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.72:kotlin-stdlib-jdk7-1.3.72.jar:40566c0c08d414b9413ba556ff7f8a0b04b98b9f0f424d122dd2088510efccc4',
@@ -94,17 +96,18 @@ dependencyVerification {
         'org.jetbrains.kotlin:kotlin-stdlib:1.3.72:kotlin-stdlib-1.3.72.jar:3856a7349ebacd6d1be6802b2fed9c4dc2c5a564ea92b6b945ac988243d4b16b',
         'org.jetbrains.trove4j:trove4j:20160824:trove4j-20160824.jar:1917871c8deb468307a584680c87a44572f5a8b0b98c6d397fc0f5f86596dbe7',
         'org.jetbrains:annotations:13.0:annotations-13.0.jar:ace2a10dc8e2d5fd34925ecac03e4988b2c0f851650c94b8cef49ba1bd111478',
-        'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
-        'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
-        'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
-        'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
+        'org.jmock:jmock-imposters:2.12.0:jmock-imposters-2.12.0.jar:3b836269745a137c9b2347e8d7c2104845b126ef04f012d6bfd94f1a7dea7b09',
+        'org.jmock:jmock-junit4:2.12.0:jmock-junit4-2.12.0.jar:3233062fc889637c151a24f1ee086bad04321ab7d8264fef279daff0fa27205b',
+        'org.jmock:jmock-legacy:2.12.0:jmock-legacy-2.12.0.jar:dea3a9cca653d082e2fe7e40232e982fe03a9984c7d67ceff24f3e03fe580dcd',
+        'org.jmock:jmock-testjar:2.12.0:jmock-testjar-2.12.0.jar:efefbcf6cd294d0e29f0c46eb2a3380d4ca4e1763ff719c69e2f2ac62f564a04',
+        'org.jmock:jmock:2.12.0:jmock-2.12.0.jar:266d07314c0cd343c46ff8a55601272de8cf406807caf55e6f313295f83d10be',
         'org.jvnet.staxex:stax-ex:1.8:stax-ex-1.8.jar:95b05d9590af4154c6513b9c5dc1fb2e55b539972ba0a9ef28e9a0c01d83ad77',
-        '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:7.0:asm-analysis-7.0.jar:e981f8f650c4d900bb033650b18e122fa6b161eadd5f88978d08751f72ee8474',
         'org.ow2.asm:asm-commons:7.0:asm-commons-7.0.jar:fed348ef05958e3e846a3ac074a12af5f7936ef3d21ce44a62c4fa08a771927d',
         'org.ow2.asm:asm-tree:7.0:asm-tree-7.0.jar:cfd7a0874f9de36a999c127feeadfbfe6e04d4a71ee954d7af3d853f0be48a6c',
         '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:7.1:asm-7.1.jar:4ab2fa2b6d2cc9ccb1eaa05ea329c407b47b13ed2915f62f8c4b8cc96258d4de',
     ]
 }

bramble-api/build.gradle

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

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

@@ -9,5 +9,4 @@ public interface FeatureFlags {
 
 	boolean shouldEnableProfilePictures();
 
-	boolean shouldEnableDisappearingMessages();
 }

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

@@ -2,6 +2,7 @@ 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;
 
@@ -43,6 +44,17 @@ 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/cleanup/CleanupHook.java

@@ -1,29 +0,0 @@
-package org.briarproject.bramble.api.cleanup;
-
-import org.briarproject.bramble.api.db.DatabaseComponent;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.MessageId;
-
-import java.util.Collection;
-
-/**
- * An interface for registering a hook with the {@link CleanupManager}
- * that will be called when a message's cleanup deadline is reached.
- */
-@NotNullByDefault
-public interface CleanupHook {
-
-	/**
-	 * Called when the cleanup deadlines of one or more messages are reached.
-	 * <p>
-	 * The callee is not required to delete the messages, but the hook won't be
-	 * called again for these messages unless another cleanup timer is set (see
-	 * {@link DatabaseComponent#setCleanupTimerDuration(Transaction, MessageId, long)}
-	 * and {@link DatabaseComponent#startCleanupTimer(Transaction, MessageId)}).
-	 */
-	void deleteMessages(Transaction txn, GroupId g,
-			Collection<MessageId> messageIds) throws DbException;
-}

bramble-api/src/main/java/org/briarproject/bramble/api/cleanup/CleanupManager.java

@@ -1,42 +0,0 @@
-package org.briarproject.bramble.api.cleanup;
-
-import org.briarproject.bramble.api.cleanup.event.CleanupTimerStartedEvent;
-import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.api.db.DatabaseComponent;
-import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.lifecycle.LifecycleManager;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.ClientId;
-import org.briarproject.bramble.api.sync.MessageId;
-
-/**
- * The CleanupManager is responsible for tracking the cleanup deadlines of
- * messages and passing them to their respective
- * {@link CleanupHook CleanupHooks} when the deadlines are reached.
- * <p>
- * The CleanupManager responds to
- * {@link CleanupTimerStartedEvent CleanupTimerStartedEvents} broadcast by the
- * {@link DatabaseComponent}.
- * <p>
- * See {@link DatabaseComponent#setCleanupTimerDuration(Transaction, MessageId, long)},
- * {@link DatabaseComponent#startCleanupTimer(Transaction, MessageId)},
- * {@link DatabaseComponent#stopCleanupTimer(Transaction, MessageId)}.
- */
-@NotNullByDefault
-public interface CleanupManager {
-
-	/**
-	 * When scheduling a cleanup task we overshoot the deadline by this many
-	 * milliseconds to reduce the number of tasks that need to be scheduled
-	 * when messages have cleanup deadlines that are close together.
-	 */
-	long BATCH_DELAY_MS = 1000;
-
-	/**
-	 * Registers a hook to be called when messages are due for cleanup.
-	 * This method should be called before
-	 * {@link LifecycleManager#startServices(SecretKey)}.
-	 */
-	void registerCleanupHook(ClientId c, int majorVersion,
-			CleanupHook hook);
-}

bramble-api/src/main/java/org/briarproject/bramble/api/cleanup/event/CleanupTimerStartedEvent.java

@@ -1,32 +0,0 @@
-package org.briarproject.bramble.api.cleanup.event;
-
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.MessageId;
-
-import javax.annotation.concurrent.Immutable;
-
-/**
- * An event that is broadcast when a message's cleanup timer is started.
- */
-@Immutable
-@NotNullByDefault
-public class CleanupTimerStartedEvent extends Event {
-
-	private final MessageId messageId;
-	private final long cleanupDeadline;
-
-	public CleanupTimerStartedEvent(MessageId messageId,
-			long cleanupDeadline) {
-		this.messageId = messageId;
-		this.cleanupDeadline = cleanupDeadline;
-	}
-
-	public MessageId getMessageId() {
-		return messageId;
-	}
-
-	public long getCleanupDeadline() {
-		return cleanupDeadline;
-	}
-}

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

@@ -1,7 +1,6 @@
 package org.briarproject.bramble.api.client;
 
 import org.briarproject.bramble.api.FormatException;
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.crypto.PrivateKey;
 import org.briarproject.bramble.api.crypto.PublicKey;
 import org.briarproject.bramble.api.data.BdfDictionary;
@@ -17,7 +16,6 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 
 import java.security.GeneralSecurityException;
-import java.util.Collection;
 import java.util.Map;
 
 @NotNullByDefault
@@ -52,11 +50,9 @@ public interface ClientHelper {
 	BdfDictionary getGroupMetadataAsDictionary(Transaction txn, GroupId g)
 			throws DbException, FormatException;
 
-	Collection<MessageId> getMessageIds(Transaction txn, GroupId g,
-			BdfDictionary query) throws DbException, FormatException;
-
 	BdfDictionary getMessageMetadataAsDictionary(MessageId m)
-			throws DbException, FormatException;
+			throws DbException,
+			FormatException;
 
 	BdfDictionary getMessageMetadataAsDictionary(Transaction txn, MessageId m)
 			throws DbException, FormatException;
@@ -123,17 +119,4 @@ public interface ClientHelper {
 	Map<TransportId, TransportProperties> parseAndValidateTransportPropertiesMap(
 			BdfDictionary properties) throws FormatException;
 
-	/**
-	 * Retrieves the contact ID from the group metadata of the given contact
-	 * group.
-	 */
-	ContactId getContactId(Transaction txn, GroupId contactGroupId)
-			throws DbException, FormatException;
-
-	/**
-	 * Stores the given contact ID in the group metadata of the given contact
-	 * group.
-	 */
-	void setContactId(Transaction txn, GroupId contactGroupId, ContactId c)
-			throws DbException;
 }

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

@@ -1,9 +0,0 @@
-package org.briarproject.bramble.api.client;
-
-public interface ContactGroupConstants {
-
-	/**
-	 * Group metadata key for associating a contact ID with a contact group.
-	 */
-	String GROUP_KEY_CONTACT_ID = "contactId";
-}

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

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

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

@@ -1,4 +1,4 @@
-package org.briarproject.bramble.contact;
+package org.briarproject.bramble.api.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
-interface ContactExchangeCrypto {
+public interface ContactExchangeCrypto {
 
 	/**
 	 * Derives the header key for a contact exchange stream from the master key.

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

@@ -0,0 +1,9 @@
+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

@@ -3,6 +3,7 @@ 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;
@@ -48,6 +49,10 @@ 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
@@ -205,6 +210,19 @@ 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}.

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

@@ -24,6 +24,19 @@ 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/AuthenticatedCipher.java

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

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

@@ -41,18 +41,6 @@ import javax.annotation.Nullable;
 @NotNullByDefault
 public interface DatabaseComponent extends TransactionManager {
 
-	/**
-	 * Return value for {@link #getNextCleanupDeadline(Transaction)} if
-	 * no messages are scheduled to be deleted.
-	 */
-	long NO_CLEANUP_DEADLINE = -1;
-
-	/**
-	 * Return value for {@link #startCleanupTimer(Transaction, MessageId)}
-	 * if the cleanup timer was not started.
-	 */
-	long TIMER_NOT_STARTED = -1;
-
 	/**
 	 * Opens the database and returns true if the database already existed.
 	 *
@@ -300,16 +288,6 @@ public interface DatabaseComponent extends TransactionManager {
 	Collection<MessageId> getMessageIds(Transaction txn, GroupId g)
 			throws DbException;
 
-	/**
-	 * Returns the IDs of any delivered messages in the given group with
-	 * metadata that matches all entries in the given query. If the query is
-	 * empty, the IDs of all delivered messages are returned.
-	 * <p/>
-	 * Read-only.
-	 */
-	Collection<MessageId> getMessageIds(Transaction txn, GroupId g,
-			Metadata query) throws DbException;
-
 	/**
 	 * Returns the IDs of any messages that need to be validated.
 	 * <p/>
@@ -336,15 +314,6 @@ public interface DatabaseComponent extends TransactionManager {
 	Collection<MessageId> getMessagesToShare(Transaction txn)
 			throws DbException;
 
-	/**
-	 * Returns the IDs of any messages of any messages that are due for
-	 * deletion, along with their group IDs.
-	 * <p/>
-	 * Read-only.
-	 */
-	Map<GroupId, Collection<MessageId>> getMessagesToDelete(Transaction txn)
-			throws DbException;
-
 	/**
 	 * Returns the metadata for all delivered messages in the given group.
 	 * <p/>
@@ -426,15 +395,6 @@ public interface DatabaseComponent extends TransactionManager {
 	MessageStatus getMessageStatus(Transaction txn, ContactId c, MessageId m)
 			throws DbException;
 
-	/**
-	 * Returns the next time (in milliseconds since the Unix epoch) when a
-	 * message is due to be deleted, or {@link #NO_CLEANUP_DEADLINE}
-	 * if no messages are scheduled to be deleted.
-	 * <p/>
-	 * Read-only.
-	 */
-	long getNextCleanupDeadline(Transaction txn) throws DbException;
-
 	/*
 	 * Returns the next time (in milliseconds since the Unix epoch) when a
 	 * message is due to be sent to the given contact. The returned value may
@@ -575,13 +535,6 @@ public interface DatabaseComponent extends TransactionManager {
 	void removeTransportKeys(Transaction txn, TransportId t, KeySetId k)
 			throws DbException;
 
-	/**
-	 * Sets the cleanup timer duration for the given message. This does not
-	 * start the message's cleanup timer.
-	 */
-	void setCleanupTimerDuration(Transaction txn, MessageId m, long duration)
-			throws DbException;
-
 	/**
 	 * Marks the given contact as verified.
 	 */
@@ -593,6 +546,11 @@ 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.
 	 */
@@ -604,12 +562,6 @@ public interface DatabaseComponent extends TransactionManager {
 	 */
 	void setMessagePermanent(Transaction txn, MessageId m) throws DbException;
 
-	/**
-	 * Marks the given message as not shared. This method is only meant for
-	 * testing.
-	 */
-	void setMessageNotShared(Transaction txn, MessageId m) throws DbException;
-
 	/**
 	 * Marks the given message as shared.
 	 */
@@ -652,22 +604,6 @@ public interface DatabaseComponent extends TransactionManager {
 	void setTransportKeysActive(Transaction txn, TransportId t, KeySetId k)
 			throws DbException;
 
-	/**
-	 * Starts the cleanup timer for the given message, if a timer duration
-	 * has been set and the timer has not already been started.
-	 *
-	 * @return The cleanup deadline, or {@link #TIMER_NOT_STARTED} if no
-	 * timer duration has been set for this message or its timer has already
-	 * been started.
-	 */
-	long startCleanupTimer(Transaction txn, MessageId m) throws DbException;
-
-	/**
-	 * Stops the cleanup timer for the given message, if the timer has been
-	 * started.
-	 */
-	void stopCleanupTimer(Transaction txn, MessageId m) throws DbException;
-
 	/**
 	 * Stores the given transport keys, deleting any keys they have replaced.
 	 */

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

@@ -26,6 +26,11 @@ 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/properties/TransportPropertyManager.java

@@ -74,6 +74,13 @@ 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/transport/KeyManager.java

@@ -35,6 +35,20 @@ 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
@@ -102,4 +116,8 @@ public interface KeyManager {
 	@Nullable
 	StreamContext getStreamContext(TransportId t, byte[] tag)
 			throws DbException;
+
+	@Nullable
+	StreamContext getStreamContextInHandshakeMode(ContactId c, TransportId t)
+			throws DbException;
 }

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

@@ -6,9 +6,7 @@ import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import javax.annotation.Nullable;
-import javax.annotation.concurrent.Immutable;
 
-@Immutable
 @NotNullByDefault
 public class ValidationUtils {
 
@@ -66,9 +64,4 @@ public class ValidationUtils {
 		if (dictionary != null && dictionary.size() != size)
 			throw new FormatException();
 	}
-
-	public static void checkRange(@Nullable Long l, long min, long max)
-			throws FormatException {
-		if (l != null && (l < min || l > max)) throw new FormatException();
-	}
 }

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

@@ -1,8 +0,0 @@
-package org.briarproject.bramble.test;
-
-public interface TimeTravel {
-
-	void setCurrentTimeMillis(long now) throws InterruptedException;
-
-	void addCurrentTimeMillis(long add) throws InterruptedException;
-}

bramble-api/witness.gradle

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

bramble-core/build.gradle

@@ -21,16 +21,25 @@ dependencies {
 
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
 	testImplementation 'org.hsqldb:hsqldb:2.3.5' // The last version that supports Java 1.6
-	testImplementation 'junit:junit:4.12'
-	testImplementation "org.jmock:jmock:2.8.2"
-	testImplementation "org.jmock:jmock-junit4:2.8.2"
-	testImplementation "org.jmock:jmock-legacy:2.8.2"
+	testImplementation 'net.jodah:concurrentunit:0.4.2'
+	testImplementation "junit:junit:$junit_version"
+	testImplementation "org.jmock:jmock:$jmock_version"
+	testImplementation "org.jmock:jmock-junit4:$jmock_version"
+	testImplementation "org.jmock:jmock-imposters:$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/BrambleCoreEagerSingletons.java

@@ -1,6 +1,5 @@
 package org.briarproject.bramble;
 
-import org.briarproject.bramble.cleanup.CleanupModule;
 import org.briarproject.bramble.contact.ContactModule;
 import org.briarproject.bramble.crypto.CryptoExecutorModule;
 import org.briarproject.bramble.db.DatabaseExecutorModule;
@@ -15,8 +14,6 @@ import org.briarproject.bramble.versioning.VersioningModule;
 
 public interface BrambleCoreEagerSingletons {
 
-	void inject(CleanupModule.EagerSingletons init);
-
 	void inject(ContactModule.EagerSingletons init);
 
 	void inject(CryptoExecutorModule.EagerSingletons init);
@@ -42,7 +39,6 @@ public interface BrambleCoreEagerSingletons {
 	class Helper {
 
 		public static void injectEagerSingletons(BrambleCoreEagerSingletons c) {
-			c.inject(new CleanupModule.EagerSingletons());
 			c.inject(new ContactModule.EagerSingletons());
 			c.inject(new CryptoExecutorModule.EagerSingletons());
 			c.inject(new DatabaseExecutorModule.EagerSingletons());

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble;
 
-import org.briarproject.bramble.cleanup.CleanupModule;
 import org.briarproject.bramble.client.ClientModule;
 import org.briarproject.bramble.connection.ConnectionModule;
 import org.briarproject.bramble.contact.ContactModule;
@@ -22,14 +21,15 @@ import org.briarproject.bramble.rendezvous.RendezvousModule;
 import org.briarproject.bramble.settings.SettingsModule;
 import org.briarproject.bramble.sync.SyncModule;
 import org.briarproject.bramble.sync.validation.ValidationModule;
+import org.briarproject.bramble.system.ClockModule;
 import org.briarproject.bramble.transport.TransportModule;
 import org.briarproject.bramble.versioning.VersioningModule;
 
 import dagger.Module;
 
 @Module(includes = {
-		CleanupModule.class,
 		ClientModule.class,
+		ClockModule.class,
 		ConnectionModule.class,
 		ContactModule.class,
 		CryptoModule.class,

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

@@ -176,6 +176,18 @@ 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/cleanup/CleanupManagerImpl.java

@@ -1,159 +0,0 @@
-package org.briarproject.bramble.cleanup;
-
-import org.briarproject.bramble.api.cleanup.CleanupHook;
-import org.briarproject.bramble.api.cleanup.CleanupManager;
-import org.briarproject.bramble.api.cleanup.event.CleanupTimerStartedEvent;
-import org.briarproject.bramble.api.db.DatabaseComponent;
-import org.briarproject.bramble.api.db.DatabaseExecutor;
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.db.Transaction;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventListener;
-import org.briarproject.bramble.api.lifecycle.Service;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.ClientId;
-import org.briarproject.bramble.api.sync.Group;
-import org.briarproject.bramble.api.sync.GroupId;
-import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.TaskScheduler;
-import org.briarproject.bramble.api.versioning.ClientMajorVersion;
-
-import java.util.Collection;
-import java.util.HashSet;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.Set;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.concurrent.Executor;
-import java.util.logging.Logger;
-
-import javax.annotation.concurrent.GuardedBy;
-import javax.annotation.concurrent.ThreadSafe;
-import javax.inject.Inject;
-
-import static java.lang.Math.max;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static java.util.logging.Level.INFO;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.db.DatabaseComponent.NO_CLEANUP_DEADLINE;
-import static org.briarproject.bramble.util.LogUtils.logException;
-
-@ThreadSafe
-@NotNullByDefault
-class CleanupManagerImpl implements CleanupManager, Service, EventListener {
-
-	private static final Logger LOG =
-			getLogger(CleanupManagerImpl.class.getName());
-
-	private final Executor dbExecutor;
-	private final DatabaseComponent db;
-	private final TaskScheduler taskScheduler;
-	private final Clock clock;
-	private final Map<ClientMajorVersion, CleanupHook> hooks =
-			new ConcurrentHashMap<>();
-	private final Object lock = new Object();
-
-	@GuardedBy("lock")
-	private final Set<CleanupTask> pending = new HashSet<>();
-
-	@Inject
-	CleanupManagerImpl(@DatabaseExecutor Executor dbExecutor,
-			DatabaseComponent db, TaskScheduler taskScheduler, Clock clock) {
-		this.dbExecutor = dbExecutor;
-		this.db = db;
-		this.taskScheduler = taskScheduler;
-		this.clock = clock;
-	}
-
-	@Override
-	public void registerCleanupHook(ClientId c, int majorVersion,
-			CleanupHook hook) {
-		hooks.put(new ClientMajorVersion(c, majorVersion), hook);
-	}
-
-	@Override
-	public void startService() {
-		maybeScheduleTask(clock.currentTimeMillis());
-	}
-
-	@Override
-	public void stopService() {
-	}
-
-	@Override
-	public void eventOccurred(Event e) {
-		if (e instanceof CleanupTimerStartedEvent) {
-			CleanupTimerStartedEvent a = (CleanupTimerStartedEvent) e;
-			maybeScheduleTask(a.getCleanupDeadline());
-		}
-	}
-
-	private void maybeScheduleTask(long deadline) {
-		synchronized (lock) {
-			for (CleanupTask task : pending) {
-				if (task.deadline <= deadline) return;
-			}
-			CleanupTask task = new CleanupTask(deadline);
-			pending.add(task);
-			scheduleTask(task);
-		}
-	}
-
-	private void scheduleTask(CleanupTask task) {
-		long now = clock.currentTimeMillis();
-		long delay = max(0, task.deadline - now + BATCH_DELAY_MS);
-		if (LOG.isLoggable(INFO)) {
-			LOG.info("Scheduling cleanup task in " + delay + " ms");
-		}
-		taskScheduler.schedule(() -> deleteMessagesAndScheduleNextTask(task),
-				dbExecutor, delay, MILLISECONDS);
-	}
-
-	private void deleteMessagesAndScheduleNextTask(CleanupTask task) {
-		try {
-			synchronized (lock) {
-				pending.remove(task);
-			}
-			long deadline = db.transactionWithResult(false, txn -> {
-				deleteMessages(txn);
-				return db.getNextCleanupDeadline(txn);
-			});
-			if (deadline != NO_CLEANUP_DEADLINE) {
-				maybeScheduleTask(deadline);
-			}
-		} catch (DbException e) {
-			logException(LOG, WARNING, e);
-		}
-	}
-
-	private void deleteMessages(Transaction txn) throws DbException {
-		Map<GroupId, Collection<MessageId>> ids = db.getMessagesToDelete(txn);
-		for (Entry<GroupId, Collection<MessageId>> e : ids.entrySet()) {
-			GroupId groupId = e.getKey();
-			Collection<MessageId> messageIds = e.getValue();
-			if (LOG.isLoggable(INFO)) {
-				LOG.info(messageIds.size() + " messages to delete");
-			}
-			for (MessageId m : messageIds) db.stopCleanupTimer(txn, m);
-			Group group = db.getGroup(txn, groupId);
-			ClientMajorVersion cv = new ClientMajorVersion(group.getClientId(),
-					group.getMajorVersion());
-			CleanupHook hook = hooks.get(cv);
-			if (hook == null) {
-				throw new IllegalStateException("No cleanup hook for " + cv);
-			}
-			hook.deleteMessages(txn, groupId, messageIds);
-		}
-	}
-
-	private static class CleanupTask {
-
-		private final long deadline;
-
-		private CleanupTask(long deadline) {
-			this.deadline = deadline;
-		}
-	}
-}

bramble-core/src/main/java/org/briarproject/bramble/cleanup/CleanupModule.java

@@ -1,29 +0,0 @@
-package org.briarproject.bramble.cleanup;
-
-import org.briarproject.bramble.api.cleanup.CleanupManager;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.lifecycle.LifecycleManager;
-
-import javax.inject.Inject;
-import javax.inject.Singleton;
-
-import dagger.Module;
-import dagger.Provides;
-
-@Module
-public class CleanupModule {
-
-	public static class EagerSingletons {
-		@Inject
-		CleanupManager cleanupManager;
-	}
-
-	@Provides
-	@Singleton
-	CleanupManager provideCleanupManager(LifecycleManager lifecycleManager,
-			EventBus eventBus, CleanupManagerImpl cleanupManager) {
-		lifecycleManager.registerService(cleanupManager);
-		eventBus.addListener(cleanupManager);
-		return cleanupManager;
-	}
-}

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

@@ -2,13 +2,11 @@ package org.briarproject.bramble.client;
 
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.client.ClientHelper;
-import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 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.data.BdfDictionary;
-import org.briarproject.bramble.api.data.BdfEntry;
 import org.briarproject.bramble.api.data.BdfList;
 import org.briarproject.bramble.api.data.BdfReader;
 import org.briarproject.bramble.api.data.BdfReaderFactory;
@@ -34,7 +32,6 @@ import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.security.GeneralSecurityException;
-import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Map.Entry;
@@ -42,7 +39,6 @@ import java.util.Map.Entry;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
-import static org.briarproject.bramble.api.client.ContactGroupConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.api.identity.Author.FORMAT_VERSION;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_PUBLIC_KEY_LENGTH;
@@ -155,12 +151,6 @@ class ClientHelperImpl implements ClientHelper {
 		return metadataParser.parse(metadata);
 	}
 
-	@Override
-	public Collection<MessageId> getMessageIds(Transaction txn, GroupId g,
-			BdfDictionary query) throws DbException, FormatException {
-		return db.getMessageIds(txn, g, metadataEncoder.encode(query));
-	}
-
 	@Override
 	public BdfDictionary getMessageMetadataAsDictionary(MessageId m)
 			throws DbException, FormatException {
@@ -399,27 +389,4 @@ class ClientHelperImpl implements ClientHelper {
 		return tpMap;
 	}
 
-	@Override
-	public ContactId getContactId(Transaction txn, GroupId contactGroupId)
-			throws DbException {
-		try {
-			BdfDictionary meta =
-					getGroupMetadataAsDictionary(txn, contactGroupId);
-			return new ContactId(meta.getLong(GROUP_KEY_CONTACT_ID).intValue());
-		} catch (FormatException e) {
-			throw new DbException(e); // Invalid group metadata
-		}
-	}
-
-	@Override
-	public void setContactId(Transaction txn, GroupId contactGroupId,
-			ContactId c) throws DbException {
-		BdfDictionary meta = BdfDictionary.of(
-				new BdfEntry(GROUP_KEY_CONTACT_ID, c.getInt()));
-		try {
-			mergeGroupMetadata(txn, contactGroupId, meta);
-		} catch (FormatException e) {
-			throw new AssertionError(e);
-		}
-	}
 }

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

@@ -47,7 +47,9 @@ abstract class Connection {
 			TransportId transportId) {
 		StreamContext ctx;
 		try {
+			LOG.info("Reading tag...");
 			byte[] tag = readTag(reader.getInputStream());
+			LOG.info("Read tag!");
 			return keyManager.getStreamContext(transportId, tag);
 		} catch (IOException | DbException e) {
 			logException(LOG, WARNING, e);

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

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

@@ -3,6 +3,7 @@ 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

@@ -2,6 +2,7 @@ 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;
@@ -13,9 +14,11 @@ 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;
@@ -24,6 +27,10 @@ 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,
@@ -32,14 +39,18 @@ 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) {
@@ -54,10 +65,22 @@ class IncomingDuplexSyncConnection extends DuplexSyncConnection
 			return;
 		}
 		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Received handshake tag, expected rotation mode");
-			onReadError(true);
-			return;
+			if (!performHandshake(ctx, contactId)) {
+				LOG.warning("Handshake failed");
+				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);
@@ -103,5 +126,39 @@ class IncomingDuplexSyncConnection extends DuplexSyncConnection
 			onWriteError();
 		}
 	}
+
+	private boolean performHandshake(StreamContext ctxIn, ContactId contactId) {
+		LOG.info("Performing handshake (Incoming)");
+		// Allocate the outgoing stream context
+		StreamContext ctxOut;
+
+		try {
+			ctxOut = keyManager.getStreamContextInHandshakeMode(contactId, transportId);
+		} catch (DbException e) {
+			logException(LOG, WARNING, e);
+			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 - IncomingDuplexSyncConnection");
+			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

@@ -2,6 +2,7 @@ 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;
@@ -14,9 +15,11 @@ 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;
 
@@ -28,27 +31,40 @@ 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(KeyManager keyManager,
+	OutgoingDuplexSyncConnection(
+			KeyManager keyManager,
 			ConnectionRegistry connectionRegistry,
 			StreamReaderFactory streamReaderFactory,
 			StreamWriterFactory streamWriterFactory,
 			SyncSessionFactory syncSessionFactory,
 			TransportPropertyManager transportPropertyManager,
-			Executor ioExecutor, SecureRandom secureRandom, ContactId contactId,
-			TransportId transportId, DuplexTransportConnection connection) {
+			Executor ioExecutor,
+			SecureRandom secureRandom,
+			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) {
 			LOG.warning("Could not allocate stream context");
@@ -56,10 +72,23 @@ class OutgoingDuplexSyncConnection extends DuplexSyncConnection
 			return;
 		}
 		if (ctx.isHandshakeMode()) {
-			// TODO: Support handshake mode for contacts
-			LOG.warning("Cannot use handshake mode stream context");
-			onWriteError();
-			return;
+			LOG.info("OutgoingDuplexSyncConnection - context is in handshake mode, performing handshake");
+			if (!performHandshake(ctx)) {
+				LOG.warning("Handshake failed");
+				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();
@@ -127,6 +156,60 @@ class OutgoingDuplexSyncConnection extends DuplexSyncConnection
 		}
 	}
 
+	private boolean performHandshake(StreamContext ctxOut) {
+		LOG.info("Performing handshake (Outgoing) for transport " +
+				ctxOut.getTransportId().getString());
+		// 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 (inContactId == 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 - OutgoingDuplexSyncConnection");
+			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/ContactExchangeCryptoImpl.java

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

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

@@ -4,6 +4,7 @@ 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;
@@ -47,8 +48,8 @@ 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.contact.ContactExchangeConstants.PROTOCOL_VERSION;
-import static org.briarproject.bramble.contact.ContactExchangeRecordTypes.CONTACT_INFO;
+import static org.briarproject.bramble.api.contact.ContactExchangeConstants.PROTOCOL_VERSION;
+import static org.briarproject.bramble.api.contact.ContactExchangeRecordTypes.CONTACT_INFO;
 import static org.briarproject.bramble.util.ValidationUtils.checkLength;
 import static org.briarproject.bramble.util.ValidationUtils.checkSize;
 
@@ -81,7 +82,8 @@ class ContactExchangeManagerImpl implements ContactExchangeManager {
 	private final ContactManager contactManager;
 	private final IdentityManager identityManager;
 	private final TransportPropertyManager transportPropertyManager;
-	private final ContactExchangeCrypto contactExchangeCrypto;
+	private final org.briarproject.bramble.api.contact.ContactExchangeCrypto
+			contactExchangeCrypto;
 	private final StreamReaderFactory streamReaderFactory;
 	private final StreamWriterFactory streamWriterFactory;
 

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

@@ -1,9 +0,0 @@
-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

@@ -9,6 +9,7 @@ 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;
@@ -119,6 +120,18 @@ 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,
@@ -234,6 +247,25 @@ 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 {

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

@@ -1,5 +1,6 @@
 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

@@ -3,6 +3,8 @@ 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;
@@ -88,6 +90,27 @@ 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/crypto/CryptoComponentImpl.java

@@ -6,6 +6,7 @@ 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;

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

@@ -1,5 +1,6 @@
 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/StreamDecrypterFactoryImpl.java

@@ -1,5 +1,6 @@
 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;

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

@@ -1,6 +1,7 @@
 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

@@ -1,5 +1,6 @@
 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;

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

@@ -1,5 +1,6 @@
 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/XSalsa20Poly1305AuthenticatedCipher.java

@@ -1,5 +1,6 @@
 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.spongycastle.crypto.DataLengthException;

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

@@ -32,6 +32,7 @@ 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;
@@ -497,25 +498,6 @@ interface Database<T> {
 	 */
 	Collection<MessageId> getMessagesToShare(T txn) throws DbException;
 
-	/**
-	 * Returns the IDs of any messages of any messages that are due for
-	 * deletion, along with their group IDs.
-	 * <p/>
-	 * Read-only.
-	 */
-	Map<GroupId, Collection<MessageId>> getMessagesToDelete(T txn)
-			throws DbException;
-
-	/**
-	 * Returns the next time (in milliseconds since the Unix epoch) when a
-	 * message is due to be deleted, or
-	 * {@link DatabaseComponent#NO_CLEANUP_DEADLINE} if no messages are
-	 * scheduled to be deleted.
-	 * <p/>
-	 * Read-only.
-	 */
-	long getNextCleanupDeadline(T txn) throws DbException;
-
 	/**
 	 * Returns the next time (in milliseconds since the Unix epoch) when a
 	 * message is due to be sent to the given contact. The returned value may
@@ -625,10 +607,8 @@ interface Database<T> {
 
 	/**
 	 * Marks a message as having been seen by the given contact.
-	 *
-	 * @return True if the message was not already marked as seen.
 	 */
-	boolean raiseSeenFlag(T txn, ContactId c, MessageId m) throws DbException;
+	void raiseSeenFlag(T txn, ContactId c, MessageId m) throws DbException;
 
 	/**
 	 * Removes a contact from the database.
@@ -692,13 +672,6 @@ interface Database<T> {
 	 */
 	void resetExpiryTime(T txn, ContactId c, MessageId m) throws DbException;
 
-	/**
-	 * Sets the cleanup timer duration for the given message. This does not
-	 * start the message's cleanup timer.
-	 */
-	void setCleanupTimerDuration(T txn, MessageId m, long duration)
-			throws DbException;
-
 	/**
 	 * Marks the given contact as verified.
 	 */
@@ -723,16 +696,20 @@ 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.
 	 */
 	void setMessagePermanent(T txn, MessageId m) throws DbException;
 
 	/**
-	 * Marks the given message as shared or not.
+	 * Marks the given message as shared.
 	 */
-	void setMessageShared(T txn, MessageId m, boolean shared)
-			throws DbException;
+	void setMessageShared(T txn, MessageId m) throws DbException;
 
 	/**
 	 * Sets the validation and delivery state of the given message.
@@ -759,22 +736,6 @@ interface Database<T> {
 	void setTransportKeysActive(T txn, TransportId t, KeySetId k)
 			throws DbException;
 
-	/**
-	 * Starts the cleanup timer for the given message, if a timer duration
-	 * has been set and the timer has not already been started.
-	 *
-	 * @return The cleanup deadline, or
-	 * {@link DatabaseComponent#TIMER_NOT_STARTED} if no timer duration has
-	 * been set for this message or its timer has already been started.
-	 */
-	long startCleanupTimer(T txn, MessageId m) throws DbException;
-
-	/**
-	 * Stops the cleanup timer for the given message, if the timer has been
-	 * started.
-	 */
-	void stopCleanupTimer(T txn, MessageId m) throws DbException;
-
 	/**
 	 * Updates the transmission count, expiry time and estimated time of arrival
 	 * of the given message with respect to the given contact, using the latency

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.db;
 
-import org.briarproject.bramble.api.cleanup.event.CleanupTimerStartedEvent;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.PendingContact;
@@ -577,15 +576,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getMessageIds(txn, g);
 	}
 
-	@Override
-	public Collection<MessageId> getMessageIds(Transaction transaction,
-			GroupId g, Metadata query) throws DbException {
-		T txn = unbox(transaction);
-		if (!db.containsGroup(txn, g))
-			throw new NoSuchGroupException();
-		return db.getMessageIds(txn, g, query);
-	}
-
 	@Override
 	public Collection<MessageId> getMessagesToValidate(Transaction transaction)
 			throws DbException {
@@ -607,13 +597,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getMessagesToShare(txn);
 	}
 
-	@Override
-	public Map<GroupId, Collection<MessageId>> getMessagesToDelete(
-			Transaction transaction) throws DbException {
-		T txn = unbox(transaction);
-		return db.getMessagesToDelete(txn);
-	}
-
 	@Override
 	public Map<MessageId, Metadata> getMessageMetadata(Transaction transaction,
 			GroupId g) throws DbException {
@@ -709,13 +692,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		return db.getMessageDependents(txn, m);
 	}
 
-	@Override
-	public long getNextCleanupDeadline(Transaction transaction)
-			throws DbException {
-		T txn = unbox(transaction);
-		return db.getNextCleanupDeadline(txn);
-	}
-
 	@Override
 	public long getNextSendTime(Transaction transaction, ContactId c)
 			throws DbException {
@@ -819,17 +795,8 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		Collection<MessageId> acked = new ArrayList<>();
 		for (MessageId m : a.getMessageIds()) {
 			if (db.containsVisibleMessage(txn, c, m)) {
-				if (db.raiseSeenFlag(txn, c, m)) {
-					// This is the first time the message has been acked by
-					// this contact. Start the cleanup timer (a no-op unless
-					// a cleanup deadline has been set for this message)
-					long deadline = db.startCleanupTimer(txn, m);
-					if (deadline != TIMER_NOT_STARTED) {
-						transaction.attach(new CleanupTimerStartedEvent(m,
-								deadline));
-					}
-					acked.add(m);
-				}
+				db.raiseSeenFlag(txn, c, m);
+				acked.add(m);
 			}
 		}
 		if (acked.size() > 0) {
@@ -985,16 +952,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.removeTransportKeys(txn, t, k);
 	}
 
-	@Override
-	public void setCleanupTimerDuration(Transaction transaction, MessageId m,
-			long duration) throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsMessage(txn, m))
-			throw new NoSuchMessageException();
-		db.setCleanupTimerDuration(txn, m, duration);
-	}
-
 	@Override
 	public void setContactVerified(Transaction transaction, ContactId c)
 			throws DbException {
@@ -1044,16 +1001,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.setMessagePermanent(txn, m);
 	}
 
-	@Override
-	public void setMessageNotShared(Transaction transaction, MessageId m)
-			throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsMessage(txn, m))
-			throw new NoSuchMessageException();
-		db.setMessageShared(txn, m, false);
-	}
-
 	@Override
 	public void setMessageShared(Transaction transaction, MessageId m)
 			throws DbException {
@@ -1063,7 +1010,7 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 			throw new NoSuchMessageException();
 		if (db.getMessageState(txn, m) != DELIVERED)
 			throw new IllegalArgumentException("Shared undelivered message");
-		db.setMessageShared(txn, m, true);
+		db.setMessageShared(txn, m);
 		transaction.attach(new MessageSharedEvent(m));
 	}
 
@@ -1093,6 +1040,15 @@ 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 {
@@ -1135,30 +1091,6 @@ class DatabaseComponentImpl<T> implements DatabaseComponent {
 		db.setTransportKeysActive(txn, t, k);
 	}
 
-	@Override
-	public long startCleanupTimer(Transaction transaction, MessageId m)
-			throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsMessage(txn, m))
-			throw new NoSuchMessageException();
-		long deadline = db.startCleanupTimer(txn, m);
-		if (deadline != TIMER_NOT_STARTED) {
-			transaction.attach(new CleanupTimerStartedEvent(m, deadline));
-		}
-		return deadline;
-	}
-
-	@Override
-	public void stopCleanupTimer(Transaction transaction, MessageId m)
-			throws DbException {
-		if (transaction.isReadOnly()) throw new IllegalArgumentException();
-		T txn = unbox(transaction);
-		if (!db.containsMessage(txn, m))
-			throw new NoSuchMessageException();
-		db.stopCleanupTimer(txn, m);
-	}
-
 	@Override
 	public void updateTransportKeys(Transaction transaction,
 			Collection<TransportKeySet> keys) throws DbException {

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

@@ -72,8 +72,6 @@ import static java.util.Arrays.asList;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
 import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.api.db.DatabaseComponent.NO_CLEANUP_DEADLINE;
-import static org.briarproject.bramble.api.db.DatabaseComponent.TIMER_NOT_STARTED;
 import static org.briarproject.bramble.api.db.Metadata.REMOVE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
@@ -100,7 +98,7 @@ import static org.briarproject.bramble.util.LogUtils.now;
 abstract class JdbcDatabase implements Database<Connection> {
 
 	// Package access for testing
-	static final int CODE_SCHEMA_VERSION = 48;
+	static final int CODE_SCHEMA_VERSION = 47;
 
 	// Time period offsets for incoming transport keys
 	private static final int OFFSET_PREV = -1;
@@ -182,11 +180,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 					+ " state INT NOT NULL,"
 					+ " shared BOOLEAN NOT NULL,"
 					+ " temporary BOOLEAN NOT NULL,"
-					// Null if no timer duration has been set
-					+ " cleanupTimerDuration BIGINT,"
-					// Null if no timer duration has been set or the timer
-					// hasn't started
-					+ " cleanupDeadline BIGINT,"
 					+ " length INT NOT NULL,"
 					+ " raw BLOB," // Null if message has been deleted
 					+ " PRIMARY KEY (messageId),"
@@ -343,10 +336,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 			"CREATE INDEX IF NOT EXISTS statusesByContactIdTimestamp"
 					+ " ON statuses (contactId, timestamp)";
 
-	private static final String INDEX_MESSAGES_BY_CLEANUP_DEADLINE =
-			"CREATE INDEX IF NOT EXISTS messagesByCleanupDeadline"
-					+ " ON messages (cleanupDeadline)";
-
 	private static final Logger LOG =
 			getLogger(JdbcDatabase.class.getName());
 
@@ -474,8 +463,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				new Migration43_44(dbTypes),
 				new Migration44_45(),
 				new Migration45_46(),
-				new Migration46_47(dbTypes),
-				new Migration47_48()
+				new Migration46_47(dbTypes)
 		);
 	}
 
@@ -543,7 +531,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 			s.executeUpdate(INDEX_MESSAGE_DEPENDENCIES_BY_DEPENDENCY_ID);
 			s.executeUpdate(INDEX_STATUSES_BY_CONTACT_ID_GROUP_ID);
 			s.executeUpdate(INDEX_STATUSES_BY_CONTACT_ID_TIMESTAMP);
-			s.executeUpdate(INDEX_MESSAGES_BY_CLEANUP_DEADLINE);
 			s.close();
 		} catch (SQLException e) {
 			tryToClose(s, LOG, WARNING);
@@ -1303,9 +1290,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	public void deleteMessage(Connection txn, MessageId m) throws DbException {
 		PreparedStatement ps = null;
 		try {
-			String sql = "UPDATE messages"
-					+ " SET raw = NULL, cleanupDeadline = NULL"
-					+ " WHERE messageId = ?";
+			String sql = "UPDATE messages SET raw = NULL WHERE messageId = ?";
 			ps = txn.prepareStatement(sql);
 			ps.setBytes(1, m.getBytes());
 			int affected = ps.executeUpdate();
@@ -1784,6 +1769,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 				// Return early if there are no matches
 				if (intersection.isEmpty()) return Collections.emptySet();
 			}
+			if (intersection == null) throw new AssertionError();
 			return intersection;
 		} catch (SQLException e) {
 			tryToClose(rs, LOG, WARNING);
@@ -2240,39 +2226,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public Map<GroupId, Collection<MessageId>> getMessagesToDelete(
-			Connection txn) throws DbException {
-		long now = clock.currentTimeMillis();
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			String sql = "SELECT messageId, groupId FROM messages"
-					+ " WHERE cleanupDeadline <= ?";
-			ps = txn.prepareStatement(sql);
-			ps.setLong(1, now);
-			rs = ps.executeQuery();
-			Map<GroupId, Collection<MessageId>> ids = new HashMap<>();
-			while (rs.next()) {
-				MessageId m = new MessageId(rs.getBytes(1));
-				GroupId g = new GroupId(rs.getBytes(2));
-				Collection<MessageId> messageIds = ids.get(g);
-				if (messageIds == null) {
-					messageIds = new ArrayList<>();
-					ids.put(g, messageIds);
-				}
-				messageIds.add(m);
-			}
-			rs.close();
-			ps.close();
-			return ids;
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public long getNextSendTime(Connection txn, ContactId c)
 			throws DbException {
@@ -2303,31 +2256,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public long getNextCleanupDeadline(Connection txn) throws DbException {
-		Statement s = null;
-		ResultSet rs = null;
-		try {
-			String sql = "SELECT cleanupDeadline FROM messages"
-					+ " WHERE cleanupDeadline IS NOT NULL"
-					+ " ORDER BY cleanupDeadline LIMIT 1";
-			s = txn.createStatement();
-			rs = s.executeQuery(sql);
-			long nextDeadline = NO_CLEANUP_DEADLINE;
-			if (rs.next()) {
-				nextDeadline = rs.getLong(1);
-				if (rs.next()) throw new AssertionError();
-			}
-			rs.close();
-			s.close();
-			return nextDeadline;
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(s, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public PendingContact getPendingContact(Connection txn, PendingContactId p)
 			throws DbException {
@@ -2848,7 +2776,7 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public boolean raiseSeenFlag(Connection txn, ContactId c, MessageId m)
+	public void raiseSeenFlag(Connection txn, ContactId c, MessageId m)
 			throws DbException {
 		PreparedStatement ps = null;
 		try {
@@ -2860,7 +2788,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 			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);
@@ -3094,25 +3021,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public void setCleanupTimerDuration(Connection txn, MessageId m,
-			long duration) throws DbException {
-		PreparedStatement ps = null;
-		try {
-			String sql = "UPDATE messages SET cleanupTimerDuration = ?"
-					+ " WHERE messageId = ? AND cleanupTimerDuration IS NULL";
-			ps = txn.prepareStatement(sql);
-			ps.setLong(1, duration);
-			ps.setBytes(2, m.getBytes());
-			int affected = ps.executeUpdate();
-			if (affected < 0 || affected > 1) throw new DbStateException();
-			ps.close();
-		} catch (SQLException e) {
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public void setContactVerified(Connection txn, ContactId c)
 			throws DbException {
@@ -3150,6 +3058,23 @@ 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 {
@@ -3220,24 +3145,22 @@ abstract class JdbcDatabase implements Database<Connection> {
 	}
 
 	@Override
-	public void setMessageShared(Connection txn, MessageId m, boolean shared)
+	public void setMessageShared(Connection txn, MessageId m)
 			throws DbException {
 		PreparedStatement ps = null;
 		try {
-			String sql = "UPDATE messages SET shared = ?"
+			String sql = "UPDATE messages SET shared = TRUE"
 					+ " WHERE messageId = ?";
 			ps = txn.prepareStatement(sql);
-			ps.setBoolean(1, shared);
-			ps.setBytes(2, m.getBytes());
+			ps.setBytes(1, m.getBytes());
 			int affected = ps.executeUpdate();
 			if (affected < 0 || affected > 1) throw new DbStateException();
 			ps.close();
 			// Update denormalised column in statuses
-			sql = "UPDATE statuses SET messageShared = ?"
+			sql = "UPDATE statuses SET messageShared = TRUE"
 					+ " WHERE messageId = ?";
 			ps = txn.prepareStatement(sql);
-			ps.setBoolean(1, shared);
-			ps.setBytes(2, m.getBytes());
+			ps.setBytes(1, m.getBytes());
 			affected = ps.executeUpdate();
 			if (affected < 0) throw new DbStateException();
 			ps.close();
@@ -3366,60 +3289,6 @@ abstract class JdbcDatabase implements Database<Connection> {
 		}
 	}
 
-	@Override
-	public long startCleanupTimer(Connection txn, MessageId m)
-			throws DbException {
-		long now = clock.currentTimeMillis();
-		PreparedStatement ps = null;
-		ResultSet rs = null;
-		try {
-			String sql = "UPDATE messages"
-					+ " SET cleanupDeadline = ? + cleanupTimerDuration"
-					+ " WHERE messageId = ?"
-					+ " AND cleanupTimerDuration IS NOT NULL"
-					+ " AND cleanupDeadline IS NULL";
-			ps = txn.prepareStatement(sql);
-			ps.setLong(1, now);
-			ps.setBytes(2, m.getBytes());
-			int affected = ps.executeUpdate();
-			if (affected < 0 || affected > 1) throw new DbStateException();
-			ps.close();
-			if (affected == 0) return TIMER_NOT_STARTED;
-			sql = "SELECT cleanupDeadline FROM messages WHERE messageId = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setBytes(1, m.getBytes());
-			rs = ps.executeQuery();
-			if (!rs.next()) throw new DbStateException();
-			long deadline = rs.getLong(1);
-			if (rs.next()) throw new DbStateException();
-			rs.close();
-			ps.close();
-			return deadline;
-		} catch (SQLException e) {
-			tryToClose(rs, LOG, WARNING);
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
-	@Override
-	public void stopCleanupTimer(Connection txn, MessageId m)
-			throws DbException {
-		PreparedStatement ps = null;
-		try {
-			String sql = "UPDATE messages SET cleanupDeadline = NULL"
-					+ " WHERE messageId = ?";
-			ps = txn.prepareStatement(sql);
-			ps.setBytes(1, m.getBytes());
-			int affected = ps.executeUpdate();
-			if (affected < 0 || affected > 1) throw new DbStateException();
-			ps.close();
-		} catch (SQLException e) {
-			tryToClose(ps, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-
 	@Override
 	public void updateExpiryTimeAndEta(Connection txn, ContactId c, MessageId m,
 			int maxLatency) throws DbException {

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

@@ -1,47 +0,0 @@
-package org.briarproject.bramble.db;
-
-import org.briarproject.bramble.api.db.DbException;
-
-import java.sql.Connection;
-import java.sql.SQLException;
-import java.sql.Statement;
-import java.util.logging.Logger;
-
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
-import static org.briarproject.bramble.db.JdbcUtils.tryToClose;
-
-class Migration47_48 implements Migration<Connection> {
-
-	private static final Logger LOG = getLogger(Migration47_48.class.getName());
-
-	@Override
-	public int getStartVersion() {
-		return 47;
-	}
-
-	@Override
-	public int getEndVersion() {
-		return 48;
-	}
-
-	@Override
-	public void migrate(Connection txn) throws DbException {
-		Statement s = null;
-		try {
-			s = txn.createStatement();
-			// Null if no timer duration has been set
-			s.execute("ALTER TABLE messages"
-					+ " ADD COLUMN cleanupTimerDuration BIGINT");
-			// Null if no timer duration has been set or the timer
-			// hasn't started
-			s.execute("ALTER TABLE messages"
-					+ " ADD COLUMN cleanupDeadline BIGINT");
-			s.execute("CREATE INDEX IF NOT EXISTS messagesByCleanupDeadline"
-					+ " ON messages (cleanupDeadline)");
-		} catch (SQLException e) {
-			tryToClose(s, LOG, WARNING);
-			throw new DbException(e);
-		}
-	}
-}

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

@@ -118,6 +118,11 @@ 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();

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

@@ -127,6 +127,7 @@ class KeyAgreementConnector {
 		List<Pair<DuplexPlugin, BdfList>> transports = new ArrayList<>();
 		for (TransportId id : PREFERRED_TRANSPORTS) {
 			TransportDescriptor d = descriptors.get(id);
+			LOG.info("id: " + id + " d: " + d);
 			Plugin p = pluginManager.getPlugin(id);
 			if (d != null && p instanceof DuplexPlugin) {
 				if (LOG.isLoggable(INFO))
@@ -137,6 +138,9 @@ class KeyAgreementConnector {
 
 		// TODO: If we don't have any transports in common with the peer,
 		//  warn the user and give up (#1224)
+        if (transports.isEmpty()) {
+           LOG.info("No transports found");
+        }
 
 		if (!transports.isEmpty()) {
 			byte[] commitment = remotePayload.getCommitment();

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

@@ -34,12 +34,12 @@ class KeyAgreementTransport {
 			Logger.getLogger(KeyAgreementTransport.class.getName());
 
 	// Accept records with current protocol version, known record type
-	private static Predicate<Record> ACCEPT = r ->
+	private static final Predicate<Record> ACCEPT = r ->
 			r.getProtocolVersion() == PROTOCOL_VERSION &&
 					isKnownRecordType(r.getRecordType());
 
 	// Ignore records with current protocol version, unknown record type
-	private static Predicate<Record> IGNORE = r ->
+	private static final Predicate<Record> IGNORE = r ->
 			r.getProtocolVersion() == PROTOCOL_VERSION &&
 					!isKnownRecordType(r.getRecordType());
 

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

@@ -470,6 +470,10 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 			if (now - then >= V3_MIGRATION_PERIOD_MS) retireV2HiddenService();
 			else publishV2HiddenService(port, privKey2);
 		}
+		if (isNullOrEmpty(privKey3)) {
+			TransportProperties p = callback.getLocalProperties();
+			privKey3 = p.get(HS_PRIVATE_KEY_V3);
+		}
 		publishV3HiddenService(port, privKey3);
 	}
 
@@ -511,9 +515,11 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		try {
 			// Use the control connection to set up the hidden service
 			if (privKey == null) {
+				LOG.info("Private key is null");
 				response = controlConnection.addOnion("NEW:ED25519-V3",
 						portLines, null);
 			} else {
+				LOG.info("Private key is not null");
 				response = controlConnection.addOnion(privKey, portLines);
 			}
 		} catch (IOException e) {
@@ -535,12 +541,15 @@ abstract class TorPlugin implements DuplexPlugin, EventHandler, EventListener {
 		if (privKey == null) {
 			// Publish the hidden service's onion hostname in transport props
 			TransportProperties p = new TransportProperties();
+			String now = String.valueOf(clock.currentTimeMillis());
 			p.put(PROP_ONION_V3, onion3);
+			p.put(HS_PRIVATE_KEY_V3, response.get(HS_PRIVKEY));
+			p.put(HS_V3_CREATED, now);
 			callback.mergeLocalProperties(p);
 			// Save the hidden service's private key for next time
 			Settings s = new Settings();
 			s.put(HS_PRIVATE_KEY_V3, response.get(HS_PRIVKEY));
-			s.put(HS_V3_CREATED, String.valueOf(clock.currentTimeMillis()));
+			s.put(HS_V3_CREATED, now);
 			callback.mergeSettings(s);
 		}
 	}

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

@@ -294,7 +294,13 @@ class TransportPropertyManagerImpl implements TransportPropertyManager,
 	public TransportProperties getRemoteProperties(ContactId c, TransportId t)
 			throws DbException {
 		return db.transactionWithResult(true, txn ->
-				getRemoteProperties(txn, db.getContact(txn, c), t));
+				getRemoteProperties(txn, c, t));
+	}
+
+	@Override
+	public TransportProperties getRemoteProperties(Transaction txn,
+			ContactId c, TransportId t) throws DbException {
+		return getRemoteProperties(txn, db.getContact(txn, c), t);
 	}
 
 	@Override

bramble-core/src/main/java/org/briarproject/bramble/transport/KeyManagerImpl.java

@@ -101,9 +101,9 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 	}
 
 	@Override
-	public Map<TransportId, KeySetId> addRotationKeys(
-			Transaction txn, ContactId c, SecretKey rootKey, long timestamp,
-			boolean alice, boolean active) throws DbException {
+	public Map<TransportId, KeySetId> addRotationKeys(Transaction txn,
+			ContactId c, SecretKey rootKey, long timestamp, boolean alice,
+			boolean active) throws DbException {
 		Map<TransportId, KeySetId> ids = new HashMap<>();
 		for (Entry<TransportId, TransportKeyManager> e : managers.entrySet()) {
 			TransportId t = e.getKey();
@@ -114,12 +114,21 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 		return ids;
 	}
 
+	@Override
+	public Map<TransportId, KeySetId> addRotationKeys(ContactId c,
+			SecretKey rootKey, long timestamp, boolean alice, boolean active)
+			throws DbException {
+		return db.transactionWithResult(false, txn ->
+				addRotationKeys(txn, c, rootKey, timestamp, alice, active));
+	}
+
 	@Override
 	public Map<TransportId, KeySetId> addContact(Transaction txn, ContactId c,
 			PublicKey theirPublicKey, KeyPair ourKeyPair)
 			throws DbException, GeneralSecurityException {
 		SecretKey staticMasterKey = transportCrypto
 				.deriveStaticMasterKey(theirPublicKey, ourKeyPair);
+		LOG.info("Deriving root handshake key " + c.toString() + " " + ourKeyPair.getPublic().toString() + " them: " + theirPublicKey.toString());
 		SecretKey rootKey =
 				transportCrypto.deriveHandshakeRootKey(staticMasterKey, false);
 		boolean alice = transportCrypto.isAlice(theirPublicKey, ourKeyPair);
@@ -127,6 +136,7 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 		for (Entry<TransportId, TransportKeyManager> e : managers.entrySet()) {
 			TransportId t = e.getKey();
 			TransportKeyManager m = e.getValue();
+			LOG.info("Adding handshake keys for transport " + t.getString());
 			ids.put(t, m.addHandshakeKeys(txn, c, rootKey, alice));
 		}
 		return ids;
@@ -137,7 +147,7 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 			PendingContactId p, PublicKey theirPublicKey, KeyPair ourKeyPair)
 			throws DbException, GeneralSecurityException {
 		SecretKey staticMasterKey = transportCrypto
-					.deriveStaticMasterKey(theirPublicKey, ourKeyPair);
+				.deriveStaticMasterKey(theirPublicKey, ourKeyPair);
 		SecretKey rootKey =
 				transportCrypto.deriveHandshakeRootKey(staticMasterKey, true);
 		boolean alice = transportCrypto.isAlice(theirPublicKey, ourKeyPair);
@@ -197,6 +207,14 @@ class KeyManagerImpl implements KeyManager, Service, EventListener {
 						m.getStreamContext(txn, tag)));
 	}
 
+	@Override
+	public StreamContext getStreamContextInHandshakeMode(ContactId c, TransportId t)
+			throws DbException {
+		return withManager(t, m ->
+				db.transactionWithNullableResult(false, txn ->
+						m.getStreamContextInHandshakeMode(txn, c)));
+	}
+
 	@Override
 	public void eventOccurred(Event e) {
 		if (e instanceof ContactRemovedEvent) {

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManager.java

@@ -48,4 +48,7 @@ interface TransportKeyManager {
 	StreamContext getStreamContext(Transaction txn, byte[] tag)
 			throws DbException;
 
+	@Nullable
+	StreamContext getStreamContextInHandshakeMode(Transaction txn, ContactId c)
+			throws DbException;
 }

bramble-core/src/main/java/org/briarproject/bramble/transport/TransportKeyManagerImpl.java

@@ -19,6 +19,7 @@ import org.briarproject.bramble.api.transport.StreamContext;
 import org.briarproject.bramble.api.transport.TransportKeySet;
 import org.briarproject.bramble.api.transport.TransportKeys;
 import org.briarproject.bramble.transport.ReorderingWindow.Change;
+import org.briarproject.bramble.util.StringUtils;
 
 import java.util.ArrayList;
 import java.util.Collection;
@@ -182,9 +183,12 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 			if (old == null || (old.getKeys().isHandshakeMode() &&
 					!ks.getKeys().isHandshakeMode()) ||
 					old.getKeySetId().getInt() < ks.getKeySetId().getInt()) {
+				LOG.info("Replacing Outgoing keys!");
 				if (ks.getContactId() == null)
 					pendingContactOutContexts.put(ks.getPendingContactId(), ks);
 				else contactOutContexts.put(ks.getContactId(), ks);
+			} else {
+				LOG.info("Not replacing Outgoing keys!");
 			}
 		}
 	}
@@ -372,6 +376,9 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 			MutableTransportKeySet ks = getOutgoingKeySet(c, p);
 			if (ks == null) return null;
 			MutableTransportKeys keys = ks.getKeys();
+
+			LOG.info("Using keys for outgoing connection - handshake mode: " +
+					keys.isHandshakeMode());
 			MutableOutgoingKeys outKeys = keys.getCurrentOutgoingKeys();
 			if (!outKeys.isActive()) throw new AssertionError();
 			if (outKeys.getStreamCounter() > MAX_32_BIT_UNSIGNED) return null;
@@ -395,7 +402,18 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		try {
 			// Look up the incoming keys for the tag
 			TagContext tagCtx = inContexts.remove(new Bytes(tag));
-			if (tagCtx == null) return null;
+			if (tagCtx == null) {
+				LOG.info("Cannot find tag!");
+				for (MutableTransportKeySet t : keys.values()) {
+					LOG.info("Header key: " + StringUtils
+							.toHexString(t.getKeys().getCurrentIncomingKeys()
+									.getHeaderKey().getBytes()));
+					LOG.info("Tag key: " + StringUtils.toHexString(
+							t.getKeys().getCurrentIncomingKeys().getTagKey()
+									.getBytes()));
+				}
+				return null;
+			}
 			MutableIncomingKeys inKeys = tagCtx.inKeys;
 			// Create a stream context
 			StreamContext ctx = new StreamContext(tagCtx.contactId,
@@ -443,6 +461,51 @@ class TransportKeyManagerImpl implements TransportKeyManager {
 		}
 	}
 
+	@Override
+	public StreamContext getStreamContextInHandshakeMode(Transaction txn,
+			ContactId c)
+			throws DbException {
+		lock.lock();
+		try {
+			MutableTransportKeySet ks = getOutgoingKeySet(c, null);
+			if (ks == null) return null;
+			MutableTransportKeys currentKeys = ks.getKeys();
+			LOG.info("Current keys handshake mode? " +
+					currentKeys.isHandshakeMode());
+			if (currentKeys.isHandshakeMode())
+				return getStreamContext(txn, c, null);
+
+			for (MutableTransportKeySet keySet : this.keys.values()) {
+				MutableTransportKeys keys = keySet.getKeys();
+				if (!keys.isHandshakeMode()) continue;
+				LOG.info("Found handshake mode keys");
+				MutableOutgoingKeys outKeys = keys.getCurrentOutgoingKeys();
+//				if (!outKeys.isActive()) throw new AssertionError();
+				if (outKeys.getStreamCounter() > MAX_32_BIT_UNSIGNED)
+					return null;
+				// Create a stream context
+				LOG.info("Creating handshake mode stream context");
+				StreamContext ctx = new StreamContext(c, null, transportId,
+						outKeys.getTagKey(), outKeys.getHeaderKey(),
+						outKeys.getStreamCounter(), keys.isHandshakeMode());
+				LOG.info("Tag key: " +
+						StringUtils.toHexString(outKeys.getTagKey().getBytes()));
+				LOG.info("Header key: " +
+						StringUtils.toHexString(outKeys.getHeaderKey().getBytes()));
+				// Increment the stream counter and write it back to the DB
+				outKeys.incrementStreamCounter();
+				db.incrementStreamCounter(txn, transportId,
+						keySet.getKeySetId());
+				LOG.info("Returning");
+				return ctx;
+			}
+			LOG.info("Cannot find handshake mode keys");
+			return null;
+		} finally {
+			lock.unlock();
+		}
+	}
+
 	@DatabaseExecutor
 	@Wakeful
 	private void updateKeys(Transaction txn) throws DbException {

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

@@ -5,5 +5,6 @@ interface ClientVersioningConstants {
 	// Metadata keys
 	String MSG_KEY_UPDATE_VERSION = "version";
 	String MSG_KEY_LOCAL = "local";
+	String GROUP_KEY_CONTACT_ID = "contactId";
 }
 

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

@@ -50,6 +50,7 @@ import static java.util.Collections.emptyList;
 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.versioning.ClientVersioningConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_LOCAL;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_UPDATE_VERSION;
 
@@ -160,7 +161,13 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		db.addGroup(txn, g);
 		db.setGroupVisibility(txn, c.getId(), g.getId(), SHARED);
 		// Attach the contact ID to the group
-		clientHelper.setContactId(txn, g.getId(), c.getId());
+		BdfDictionary meta = new BdfDictionary();
+		meta.put(GROUP_KEY_CONTACT_ID, c.getId().getInt());
+		try {
+			clientHelper.mergeGroupMetadata(txn, g.getId(), meta);
+		} catch (FormatException e) {
+			throw new AssertionError(e);
+		}
 		// Create and store the first local update
 		List<ClientVersion> versions = new ArrayList<>(clients);
 		Collections.sort(versions);
@@ -222,7 +229,7 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 			Map<ClientMajorVersion, Visibility> after =
 					getVisibilities(newLocalStates, newRemoteStates);
 			// Call hooks for any visibilities that have changed
-			ContactId c = clientHelper.getContactId(txn, m.getGroupId());
+			ContactId c = getContactId(txn, m.getGroupId());
 			if (!before.equals(after)) {
 				Contact contact = db.getContact(txn, c);
 				callVisibilityHooks(txn, contact, before, after);
@@ -514,6 +521,17 @@ class ClientVersioningManagerImpl implements ClientVersioningManager,
 		storeUpdate(txn, g, states, 1);
 	}
 
+	private ContactId getContactId(Transaction txn, GroupId g)
+			throws DbException {
+		try {
+			BdfDictionary meta =
+					clientHelper.getGroupMetadataAsDictionary(txn, g);
+			return new ContactId(meta.getLong(GROUP_KEY_CONTACT_ID).intValue());
+		} catch (FormatException e) {
+			throw new DbException(e);
+		}
+	}
+
 	private List<ClientState> updateStatesFromRemoteStates(
 			List<ClientState> oldLocalStates, List<ClientState> remoteStates) {
 		Set<ClientMajorVersion> remoteSet = new HashSet<>();

bramble-core/src/main/resources/bridges

@@ -2,12 +2,11 @@ Bridge obfs4 192.95.36.142:443 CDF2E852BF539B82BD10E27E9115A31734E378C2 cert=qUV
 Bridge obfs4 38.229.1.78:80 C8CBDB2464FC9804A69531437BCF2BE31FDD2EE4 cert=Hmyfd2ev46gGY7NoVxA9ngrPF2zCZtzskRTzoWXbxNkzeVnGFPWmrTtILRyqCTjHR+s9dg iat-mode=1
 Bridge obfs4 37.218.245.14:38224 D9A82D2F9C2F65A18407B1D2B764F130847F8B5D cert=bjRaMrr1BRiAW8IE9U5z27fQaYgOhX1UCmOpg2pFpoMvo6ZgQMzLsaTzzQNTlm7hNcb+Sg iat-mode=0
 Bridge obfs4 85.31.186.98:443 011F2599C0E9B27EE74B353155E244813763C3E5 cert=ayq0XzCwhpdysn5o0EyDUbmSOx3X/oTEbzDMvczHOdBJKlvIdHHLJGkZARtT4dcBFArPPg iat-mode=0
-Bridge obfs4 85.31.186.26:443 91A6354697E6B02A386312F68D82CF86824D3606 cert=PBwr+S8JTVZo6MPdHnkTwXJPILWADLqfMGoVvhZClMq/Urndyd42BwX9YFJHZnBB3H0XCw iat-mode=0
+Bridge obfs4 144.217.20.138:80 FB70B257C162BF1038CA669D568D76F5B7F0BABB cert=vYIV5MgrghGQvZPIi1tJwnzorMgqgmlKaB77Y3Z9Q/v94wZBOAXkW+fdx4aSxLVnKO+xNw iat-mode=0
 Bridge obfs4 193.11.166.194:27015 2D82C2E354D531A68469ADF7F878FA6060C6BACA cert=4TLQPJrTSaDffMK7Nbao6LC7G9OW/NHkUwIdjLSS3KYf0Nv4/nQiiI8dY2TcsQx01NniOg iat-mode=0
 Bridge obfs4 193.11.166.194:27020 86AC7B8D430DAC4117E9F42C9EAED18133863AAF cert=0LDeJH4JzMDtkJJrFphJCiPqKx7loozKN7VNfuukMGfHO0Z8OGdzHVkhVAOfo1mUdv9cMg iat-mode=0
 Bridge obfs4 193.11.166.194:27025 1AE2C08904527FEA90C4C4F8C1083EA59FBC6FAF cert=ItvYZzW5tn6v3G4UnQa6Qz04Npro6e81AP70YujmK/KXwDFPTs3aHXcHp4n8Vt6w/bv8cA iat-mode=0
 Bridge obfs4 209.148.46.65:443 74FAD13168806246602538555B5521A0383A1875 cert=ssH+9rP8dG2NLDN2XuFw63hIO/9MNNinLmxQDpVa+7kTOa9/m+tGWT1SmSYpQ9uTBGa6Hw iat-mode=0
-Bridge obfs4 146.57.248.225:22 10A6CD36A537FCE513A322361547444B393989F0 cert=K1gDtDAIcUfeLqbstggjIw2rtgIKqdIhUlHp82XRqNSq/mtAjp1BIC9vHKJ2FAEpGssTPw iat-mode=0
 Bridge obfs4 45.145.95.6:27015 C5B7CD6946FF10C5B3E89691A7D3F2C122D2117C cert=TD7PbUO0/0k6xYHMPW3vJxICfkMZNdkRrb63Zhl5j9dW3iRGiCx0A7mPhe5T2EDzQ35+Zw iat-mode=0
 Bridge obfs4 51.222.13.177:80 5EDAC3B810E12B01F6FD8050D2FD3E277B289A08 cert=2uplIpLQ0q9+0qMFrK5pkaYRDOe460LL9WHBvatgkuRr/SL31wBOEupaMMJ6koRE6Ld0ew iat-mode=0
 Bridge obfs4 78.46.188.239:37356 5A2D2F4158D0453E00C7C176978D3F41D69C45DB cert=3c0SwxpOisbohNxEc4tb875RVW8eOu1opRTVXJhafaKA/PNNtI7ElQIVOVZg1AdL5bxGCw iat-mode=0

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

@@ -1,18 +1,18 @@
 package org.briarproject.bramble;
 
-import org.briarproject.bramble.system.TimeTravelModule;
+import org.briarproject.bramble.system.DefaultTaskSchedulerModule;
 
 public interface BrambleCoreIntegrationTestEagerSingletons
 		extends BrambleCoreEagerSingletons {
 
-	void inject(TimeTravelModule.EagerSingletons init);
+	void inject(DefaultTaskSchedulerModule.EagerSingletons init);
 
 	class Helper {
 
 		public static void injectEagerSingletons(
 				BrambleCoreIntegrationTestEagerSingletons c) {
 			BrambleCoreEagerSingletons.Helper.injectEagerSingletons(c);
-			c.inject(new TimeTravelModule.EagerSingletons());
+			c.inject(new DefaultTaskSchedulerModule.EagerSingletons());
 		}
 	}
 }

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

@@ -13,7 +13,7 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageContext;
 import org.briarproject.bramble.test.ValidatorTestCase;
 import org.jmock.Expectations;
-import org.jmock.lib.legacy.ClassImposteriser;
+import org.jmock.imposters.ByteBuddyClassImposteriser;
 import org.junit.Test;
 
 import static org.briarproject.bramble.api.transport.TransportConstants.MAX_CLOCK_DIFFERENCE;
@@ -38,7 +38,7 @@ public class BdfMessageValidatorTest extends ValidatorTestCase {
 	private final Metadata meta = new Metadata();
 
 	public BdfMessageValidatorTest() {
-		context.setImposteriser(ClassImposteriser.INSTANCE);
+		context.setImposteriser(ByteBuddyClassImposteriser.INSTANCE);
 	}
 
 	@Test(expected = InvalidMessageException.class)

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestUtils;

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

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.test.TestUtils;

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

@@ -1,5 +1,6 @@
 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;
 

bramble-core/src/test/java/org/briarproject/bramble/crypto/XSalsa20Poly1305AuthenticatedCipherTest.java

@@ -1,5 +1,6 @@
 package org.briarproject.bramble.crypto;
 
+import org.briarproject.bramble.api.crypto.AuthenticatedCipher;
 import org.briarproject.bramble.api.crypto.SecretKey;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.briarproject.bramble.util.StringUtils;

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

@@ -1,6 +1,5 @@
 package org.briarproject.bramble.db;
 
-import org.briarproject.bramble.api.cleanup.event.CleanupTimerStartedEvent;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.PendingContactId;
@@ -70,8 +69,6 @@ import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
-import static java.util.concurrent.TimeUnit.HOURS;
-import static org.briarproject.bramble.api.db.DatabaseComponent.TIMER_NOT_STARTED;
 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;
@@ -513,11 +510,11 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			throws Exception {
 		context.checking(new Expectations() {{
 			// Check whether the group is in the DB (which it's not)
-			exactly(10).of(database).startTransaction();
+			exactly(8).of(database).startTransaction();
 			will(returnValue(txn));
-			exactly(10).of(database).containsGroup(txn, groupId);
+			exactly(8).of(database).containsGroup(txn, groupId);
 			will(returnValue(false));
-			exactly(10).of(database).abortTransaction(txn);
+			exactly(8).of(database).abortTransaction(txn);
 			// Allow other checks to pass
 			allowing(database).containsContact(txn, contactId);
 			will(returnValue(true));
@@ -526,7 +523,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 				eventExecutor, shutdownManager);
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getGroup(transaction, groupId));
 			fail();
 		} catch (NoSuchGroupException expected) {
@@ -534,7 +531,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getGroupMetadata(transaction, groupId));
 			fail();
 		} catch (NoSuchGroupException expected) {
@@ -542,23 +539,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
-					db.getMessageIds(transaction, groupId));
-			fail();
-		} catch (NoSuchGroupException expected) {
-			// Expected
-		}
-
-		try {
-			db.transaction(true, transaction ->
-					db.getMessageIds(transaction, groupId, new Metadata()));
-			fail();
-		} catch (NoSuchGroupException expected) {
-			// Expected
-		}
-
-		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getMessageMetadata(transaction, groupId));
 			fail();
 		} catch (NoSuchGroupException expected) {
@@ -566,7 +547,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getMessageMetadata(transaction, groupId,
 							new Metadata()));
 			fail();
@@ -575,7 +556,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getMessageStatus(transaction, contactId, groupId));
 			fail();
 		} catch (NoSuchGroupException expected) {
@@ -613,11 +594,11 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			throws Exception {
 		context.checking(new Expectations() {{
 			// Check whether the message is in the DB (which it's not)
-			exactly(15).of(database).startTransaction();
+			exactly(12).of(database).startTransaction();
 			will(returnValue(txn));
-			exactly(15).of(database).containsMessage(txn, messageId);
+			exactly(12).of(database).containsMessage(txn, messageId);
 			will(returnValue(false));
-			exactly(15).of(database).abortTransaction(txn);
+			exactly(12).of(database).abortTransaction(txn);
 			// Allow other checks to pass
 			allowing(database).containsContact(txn, contactId);
 			will(returnValue(true));
@@ -642,7 +623,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getMessage(transaction, messageId));
 			fail();
 		} catch (NoSuchMessageException expected) {
@@ -650,7 +631,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getMessageMetadata(transaction, messageId));
 			fail();
 		} catch (NoSuchMessageException expected) {
@@ -658,7 +639,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getMessageState(transaction, messageId));
 			fail();
 		} catch (NoSuchMessageException expected) {
@@ -666,7 +647,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getMessageStatus(transaction, contactId, messageId));
 			fail();
 		} catch (NoSuchMessageException expected) {
@@ -681,15 +662,6 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			// Expected
 		}
 
-		try {
-			db.transaction(false, transaction ->
-					db.setCleanupTimerDuration(transaction, message.getId(),
-							HOURS.toMillis(1)));
-			fail();
-		} catch (NoSuchMessageException expected) {
-			// Expected
-		}
-
 		try {
 			db.transaction(false, transaction ->
 					db.setMessagePermanent(transaction, message.getId()));
@@ -715,7 +687,7 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getMessageDependencies(transaction, messageId));
 			fail();
 		} catch (NoSuchMessageException expected) {
@@ -723,28 +695,12 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		}
 
 		try {
-			db.transaction(true, transaction ->
+			db.transaction(false, transaction ->
 					db.getMessageDependents(transaction, messageId));
 			fail();
 		} catch (NoSuchMessageException expected) {
 			// Expected
 		}
-
-		try {
-			db.transaction(false, transaction ->
-					db.startCleanupTimer(transaction, messageId));
-			fail();
-		} catch (NoSuchMessageException expected) {
-			// Expected
-		}
-
-		try {
-			db.transaction(false, transaction ->
-					db.stopCleanupTimer(transaction, messageId));
-			fail();
-		} catch (NoSuchMessageException expected) {
-			// Expected
-		}
 	}
 
 	@Test
@@ -1025,9 +981,6 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 			oneOf(database).containsVisibleMessage(txn, contactId, messageId);
 			will(returnValue(true));
 			oneOf(database).raiseSeenFlag(txn, contactId, messageId);
-			will(returnValue(true));
-			oneOf(database).startCleanupTimer(txn, messageId);
-			will(returnValue(TIMER_NOT_STARTED)); // No cleanup duration was set
 			oneOf(database).commitTransaction(txn);
 			oneOf(eventBus).broadcast(with(any(MessagesAckedEvent.class)));
 		}});
@@ -1040,56 +993,6 @@ public class DatabaseComponentImplTest extends BrambleMockTestCase {
 		});
 	}
 
-	@Test
-	public void testReceiveDuplicateAck() throws Exception {
-		context.checking(new Expectations() {{
-			oneOf(database).startTransaction();
-			will(returnValue(txn));
-			oneOf(database).containsContact(txn, contactId);
-			will(returnValue(true));
-			oneOf(database).containsVisibleMessage(txn, contactId, messageId);
-			will(returnValue(true));
-			oneOf(database).raiseSeenFlag(txn, contactId, messageId);
-			will(returnValue(false)); // Already acked
-			oneOf(database).commitTransaction(txn);
-		}});
-		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				eventExecutor, shutdownManager);
-
-		db.transaction(false, transaction -> {
-			Ack a = new Ack(singletonList(messageId));
-			db.receiveAck(transaction, contactId, a);
-		});
-	}
-
-	@Test
-	public void testReceiveAckWithCleanupTimer() throws Exception {
-		long deadline = System.currentTimeMillis();
-		context.checking(new Expectations() {{
-			oneOf(database).startTransaction();
-			will(returnValue(txn));
-			oneOf(database).containsContact(txn, contactId);
-			will(returnValue(true));
-			oneOf(database).containsVisibleMessage(txn, contactId, messageId);
-			will(returnValue(true));
-			oneOf(database).raiseSeenFlag(txn, contactId, messageId);
-			will(returnValue(true));
-			oneOf(database).startCleanupTimer(txn, messageId);
-			will(returnValue(deadline));
-			oneOf(database).commitTransaction(txn);
-			oneOf(eventBus).broadcast(with(any(
-					CleanupTimerStartedEvent.class)));
-			oneOf(eventBus).broadcast(with(any(MessagesAckedEvent.class)));
-		}});
-		DatabaseComponent db = createDatabaseComponent(database, eventBus,
-				eventExecutor, shutdownManager);
-
-		db.transaction(false, transaction -> {
-			Ack a = new Ack(singletonList(messageId));
-			db.receiveAck(transaction, contactId, a);
-		});
-	}
-
 	@Test
 	public void testReceiveMessage() throws Exception {
 		context.checking(new Expectations() {{

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

@@ -53,11 +53,10 @@ import java.util.concurrent.atomic.AtomicLong;
 
 import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
+import static java.util.Collections.emptyMap;
 import static java.util.Collections.singletonList;
 import static java.util.Collections.singletonMap;
 import static java.util.concurrent.TimeUnit.SECONDS;
-import static org.briarproject.bramble.api.db.DatabaseComponent.NO_CLEANUP_DEADLINE;
-import static org.briarproject.bramble.api.db.DatabaseComponent.TIMER_NOT_STARTED;
 import static org.briarproject.bramble.api.db.Metadata.REMOVE;
 import static org.briarproject.bramble.api.identity.AuthorConstants.MAX_AUTHOR_NAME_LENGTH;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
@@ -352,7 +351,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertTrue(ids.isEmpty());
 
 		// Sharing the message should make it sendable
-		db.setMessageShared(txn, messageId, true);
+		db.setMessageShared(txn, messageId);
 		ids = db.getMessagesToSend(txn, contactId, ONE_MEGABYTE, MAX_LATENCY);
 		assertEquals(singletonList(messageId), ids);
 		ids = db.getMessagesToOffer(txn, contactId, 100, MAX_LATENCY);
@@ -632,7 +631,8 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 
 		// The group should not be visible to the contact
 		assertEquals(INVISIBLE, db.getGroupVisibility(txn, contactId, groupId));
-		assertTrue(db.getGroupVisibility(txn, groupId).isEmpty());
+		assertEquals(emptyMap(),
+				db.getGroupVisibility(txn, groupId));
 
 		// Make the group visible to the contact
 		db.addGroupVisibility(txn, contactId, groupId, false);
@@ -655,7 +655,8 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		// Make the group invisible again
 		db.removeGroupVisibility(txn, contactId, groupId);
 		assertEquals(INVISIBLE, db.getGroupVisibility(txn, contactId, groupId));
-		assertTrue(db.getGroupVisibility(txn, groupId).isEmpty());
+		assertEquals(emptyMap(),
+				db.getGroupVisibility(txn, groupId));
 
 		db.commitTransaction(txn);
 		db.close();
@@ -2039,7 +2040,7 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		assertEquals(Long.MAX_VALUE, db.getNextSendTime(txn, contactId));
 
 		// Share the message - now it should be sendable immediately
-		db.setMessageShared(txn, messageId, true);
+		db.setMessageShared(txn, messageId);
 		assertEquals(0, db.getNextSendTime(txn, contactId));
 
 		// Mark the message as requested - it should still be sendable
@@ -2346,87 +2347,6 @@ public abstract class JdbcDatabaseTest extends BrambleTestCase {
 		db.close();
 	}
 
-	@Test
-	public void testCleanupTimer() throws Exception {
-		long duration = 60_000;
-		long now = System.currentTimeMillis();
-		AtomicLong time = new AtomicLong(now);
-		Database<Connection> db =
-				open(false, new TestMessageFactory(), new SettableClock(time));
-		Connection txn = db.startTransaction();
-
-		// No messages should be due or scheduled for deletion
-		assertTrue(db.getMessagesToDelete(txn).isEmpty());
-		assertEquals(NO_CLEANUP_DEADLINE, db.getNextCleanupDeadline(txn));
-
-		// Add a group and a message
-		db.addGroup(txn, group);
-		db.addMessage(txn, message, DELIVERED, false, false, null);
-
-		// No messages should be due or scheduled for deletion
-		assertTrue(db.getMessagesToDelete(txn).isEmpty());
-		assertEquals(NO_CLEANUP_DEADLINE, db.getNextCleanupDeadline(txn));
-
-		// Set the message's cleanup timer duration
-		db.setCleanupTimerDuration(txn, messageId, duration);
-
-		// No messages should be due or scheduled for deletion
-		assertTrue(db.getMessagesToDelete(txn).isEmpty());
-		assertEquals(NO_CLEANUP_DEADLINE, db.getNextCleanupDeadline(txn));
-
-		// Start the message's cleanup timer
-		assertEquals(now + duration, db.startCleanupTimer(txn, messageId));
-
-		// The timer can't be started again
-		assertEquals(TIMER_NOT_STARTED, db.startCleanupTimer(txn, messageId));
-
-		// No messages should be due for deletion, but the message should be
-		// scheduled for deletion
-		assertTrue(db.getMessagesToDelete(txn).isEmpty());
-		assertEquals(now + duration, db.getNextCleanupDeadline(txn));
-
-		// Stop the timer
-		db.stopCleanupTimer(txn, messageId);
-
-		// No messages should be due or scheduled for deletion
-		assertTrue(db.getMessagesToDelete(txn).isEmpty());
-		assertEquals(NO_CLEANUP_DEADLINE, db.getNextCleanupDeadline(txn));
-
-		// Start the timer again
-		assertEquals(now + duration, db.startCleanupTimer(txn, messageId));
-
-		// No messages should be due for deletion, but the message should be
-		// scheduled for deletion
-		assertTrue(db.getMessagesToDelete(txn).isEmpty());
-		assertEquals(now + duration, db.getNextCleanupDeadline(txn));
-
-		// 1 ms before the timer expires, no messages should be due for
-		// deletion but the message should be scheduled for deletion
-		time.set(now + duration - 1);
-		assertTrue(db.getMessagesToDelete(txn).isEmpty());
-		assertEquals(now + duration, db.getNextCleanupDeadline(txn));
-
-		// When the timer expires, the message should be due and scheduled for
-		// deletion
-		time.set(now + duration);
-		assertEquals(singletonMap(groupId, singletonList(messageId)),
-				db.getMessagesToDelete(txn));
-		assertEquals(now + duration, db.getNextCleanupDeadline(txn));
-
-		// 1 ms after the timer expires, the message should be due and
-		// scheduled for deletion
-		time.set(now + duration + 1);
-		assertEquals(singletonMap(groupId, singletonList(messageId)),
-				db.getMessagesToDelete(txn));
-		assertEquals(now + duration, db.getNextCleanupDeadline(txn));
-
-		// Once the message has been deleted, it should no longer be due
-		// or scheduled for deletion
-		db.deleteMessage(txn, messageId);
-		assertTrue(db.getMessagesToDelete(txn).isEmpty());
-		assertEquals(NO_CLEANUP_DEADLINE, db.getNextCleanupDeadline(txn));
-	}
-
 	private Database<Connection> open(boolean resume) throws Exception {
 		return open(resume, new TestMessageFactory(), new SystemClock());
 	}

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

@@ -11,8 +11,8 @@ import org.briarproject.bramble.api.keyagreement.PayloadEncoder;
 import org.briarproject.bramble.test.BrambleTestCase;
 import org.jmock.Expectations;
 import org.jmock.auto.Mock;
+import org.jmock.imposters.ByteBuddyClassImposteriser;
 import org.jmock.integration.junit4.JUnitRuleMockery;
-import org.jmock.lib.legacy.ClassImposteriser;
 import org.junit.Rule;
 import org.junit.Test;
 
@@ -34,7 +34,7 @@ public class KeyAgreementProtocolTest extends BrambleTestCase {
 	@Rule
 	public JUnitRuleMockery context = new JUnitRuleMockery() {{
 		// So we can mock concrete classes like KeyAgreementTransport
-		setImposteriser(ClassImposteriser.INSTANCE);
+		setImposteriser(ByteBuddyClassImposteriser.INSTANCE);
 	}};
 
 	private final PublicKey alicePubKey = getAgreementPublicKey();

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

@@ -14,7 +14,7 @@ import org.briarproject.bramble.api.record.RecordWriterFactory;
 import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.CaptureArgumentAction;
 import org.jmock.Expectations;
-import org.jmock.lib.legacy.ClassImposteriser;
+import org.jmock.imposters.ByteBuddyClassImposteriser;
 import org.junit.Test;
 
 import java.io.InputStream;
@@ -58,7 +58,7 @@ public class KeyAgreementTransportTest extends BrambleMockTestCase {
 	private KeyAgreementTransport kat;
 
 	public KeyAgreementTransportTest() {
-		context.setImposteriser(ClassImposteriser.INSTANCE);
+		context.setImposteriser(ByteBuddyClassImposteriser.INSTANCE);
 		inputStream = context.mock(InputStream.class);
 		outputStream = context.mock(OutputStream.class);
 	}

bramble-core/src/test/java/org/briarproject/bramble/plugin/PollerImplTest.java

@@ -25,7 +25,7 @@ import org.briarproject.bramble.test.BrambleMockTestCase;
 import org.briarproject.bramble.test.ImmediateExecutor;
 import org.briarproject.bramble.test.RunAction;
 import org.jmock.Expectations;
-import org.jmock.lib.legacy.ClassImposteriser;
+import org.jmock.imposters.ByteBuddyClassImposteriser;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -69,7 +69,7 @@ public class PollerImplTest extends BrambleMockTestCase {
 	private PollerImpl poller;
 
 	public PollerImplTest() {
-		context.setImposteriser(ClassImposteriser.INSTANCE);
+		context.setImposteriser(ByteBuddyClassImposteriser.INSTANCE);
 		random = context.mock(SecureRandom.class);
 	}
 

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

@@ -1,122 +0,0 @@
-package org.briarproject.bramble.system;
-
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.TaskScheduler;
-
-import java.util.Queue;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.Executor;
-import java.util.concurrent.PriorityBlockingQueue;
-import java.util.concurrent.TimeUnit;
-import java.util.concurrent.atomic.AtomicBoolean;
-
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static java.util.concurrent.TimeUnit.MINUTES;
-import static org.junit.Assert.fail;
-
-/**
- * A {@link TaskScheduler} for use in tests. The scheduler keeps all scheduled
- * tasks in a queue until {@link #runTasks()} is called.
- */
-@NotNullByDefault
-class TestTaskScheduler implements TaskScheduler {
-
-	private final Queue<Task> queue = new PriorityBlockingQueue<>();
-	private final Clock clock;
-
-	TestTaskScheduler(Clock clock) {
-		this.clock = clock;
-	}
-
-	@Override
-	public Cancellable schedule(Runnable task, Executor executor, long delay,
-			TimeUnit unit) {
-		AtomicBoolean cancelled = new AtomicBoolean(false);
-		return schedule(task, executor, delay, unit, cancelled);
-	}
-
-	@Override
-	public Cancellable scheduleWithFixedDelay(Runnable task, Executor executor,
-			long delay, long interval, TimeUnit unit) {
-		AtomicBoolean cancelled = new AtomicBoolean(false);
-		return scheduleWithFixedDelay(task, executor, delay, interval, unit,
-				cancelled);
-	}
-
-	private Cancellable schedule(Runnable task, Executor executor, long delay,
-			TimeUnit unit, AtomicBoolean cancelled) {
-		long delayMillis = MILLISECONDS.convert(delay, unit);
-		long dueMillis = clock.currentTimeMillis() + delayMillis;
-		Task t = new Task(task, executor, dueMillis, cancelled);
-		queue.add(t);
-		return t;
-	}
-
-	private Cancellable scheduleWithFixedDelay(Runnable task, Executor executor,
-			long delay, long interval, TimeUnit unit, AtomicBoolean cancelled) {
-		// All executions of this periodic task share a cancelled flag
-		Runnable wrapped = () -> {
-			task.run();
-			scheduleWithFixedDelay(task, executor, interval, interval, unit,
-					cancelled);
-		};
-		return schedule(wrapped, executor, delay, unit, cancelled);
-	}
-
-	/**
-	 * Runs any scheduled tasks that are due.
-	 */
-	void runTasks() throws InterruptedException {
-		long now = clock.currentTimeMillis();
-		while (true) {
-			Task t = queue.peek();
-			if (t == null || t.dueMillis > now) return;
-			t = queue.poll();
-			// Submit the task to its executor and wait for it to finish
-			if (!t.run().await(1, MINUTES)) fail();
-		}
-	}
-
-	private static class Task
-			implements Cancellable, Comparable<Task> {
-
-		private final Runnable task;
-		private final Executor executor;
-		private final long dueMillis;
-		private final AtomicBoolean cancelled;
-
-		private Task(Runnable task, Executor executor, long dueMillis,
-				AtomicBoolean cancelled) {
-			this.task = task;
-			this.executor = executor;
-			this.dueMillis = dueMillis;
-			this.cancelled = cancelled;
-		}
-
-		@SuppressWarnings("UseCompareMethod") // Animal Sniffer
-		@Override
-		public int compareTo(Task task) {
-			return Long.valueOf(dueMillis).compareTo(task.dueMillis);
-		}
-
-		/**
-		 * Submits the task to its executor and returns a latch that will be
-		 * released when the task finishes.
-		 */
-		public CountDownLatch run() {
-			if (cancelled.get()) return new CountDownLatch(0);
-			CountDownLatch latch = new CountDownLatch(1);
-			executor.execute(() -> {
-				task.run();
-				latch.countDown();
-			});
-			return latch;
-		}
-
-		@Override
-		public void cancel() {
-			cancelled.set(true);
-		}
-	}
-}

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

@@ -1,98 +0,0 @@
-package org.briarproject.bramble.system;
-
-import org.briarproject.bramble.api.lifecycle.LifecycleManager;
-import org.briarproject.bramble.api.system.Clock;
-import org.briarproject.bramble.api.system.TaskScheduler;
-import org.briarproject.bramble.test.SettableClock;
-import org.briarproject.bramble.test.TimeTravel;
-
-import java.util.concurrent.RejectedExecutionHandler;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.ScheduledThreadPoolExecutor;
-import java.util.concurrent.atomic.AtomicLong;
-
-import javax.inject.Inject;
-import javax.inject.Singleton;
-
-import dagger.Module;
-import dagger.Provides;
-
-@Module
-public class TimeTravelModule {
-
-	public static class EagerSingletons {
-		@Inject
-		TaskScheduler scheduler;
-	}
-
-	private final ScheduledExecutorService scheduledExecutorService;
-	private final Clock clock;
-	private final TaskScheduler taskScheduler;
-	private final TimeTravel timeTravel;
-
-	public TimeTravelModule() {
-		this(false);
-	}
-
-	public TimeTravelModule(boolean travel) {
-		// Discard tasks that are submitted during shutdown
-		RejectedExecutionHandler policy =
-				new ScheduledThreadPoolExecutor.DiscardPolicy();
-		scheduledExecutorService =
-				new ScheduledThreadPoolExecutor(1, policy);
-		if (travel) {
-			// Use a SettableClock and TestTaskScheduler to allow time travel
-			AtomicLong time = new AtomicLong(System.currentTimeMillis());
-			clock = new SettableClock(time);
-			TestTaskScheduler testTaskScheduler = new TestTaskScheduler(clock);
-			taskScheduler = testTaskScheduler;
-			timeTravel = new TimeTravel() {
-				@Override
-				public void setCurrentTimeMillis(long now)
-						throws InterruptedException {
-					time.set(now);
-					testTaskScheduler.runTasks();
-				}
-
-				@Override
-				public void addCurrentTimeMillis(long add)
-						throws InterruptedException {
-					time.addAndGet(add);
-					testTaskScheduler.runTasks();
-				}
-			};
-		} else {
-			// Use the default clock and task scheduler
-			clock = new SystemClock();
-			taskScheduler = new TaskSchedulerImpl(scheduledExecutorService);
-			timeTravel = new TimeTravel() {
-				@Override
-				public void setCurrentTimeMillis(long now) {
-					throw new UnsupportedOperationException();
-				}
-
-				@Override
-				public void addCurrentTimeMillis(long add) {
-					throw new UnsupportedOperationException();
-				}
-			};
-		}
-	}
-
-	@Provides
-	Clock provideClock() {
-		return clock;
-	}
-
-	@Provides
-	@Singleton
-	TaskScheduler provideTaskScheduler(LifecycleManager lifecycleManager) {
-		lifecycleManager.registerForShutdown(scheduledExecutorService);
-		return taskScheduler;
-	}
-
-	@Provides
-	TimeTravel provideTimeTravel() {
-		return timeTravel;
-	}
-}

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

@@ -3,8 +3,8 @@ package org.briarproject.bramble.test;
 import org.briarproject.bramble.api.FeatureFlags;
 import org.briarproject.bramble.battery.DefaultBatteryManagerModule;
 import org.briarproject.bramble.event.DefaultEventExecutorModule;
+import org.briarproject.bramble.system.DefaultTaskSchedulerModule;
 import org.briarproject.bramble.system.DefaultWakefulIoExecutorModule;
-import org.briarproject.bramble.system.TimeTravelModule;
 
 import dagger.Module;
 import dagger.Provides;
@@ -12,11 +12,11 @@ import dagger.Provides;
 @Module(includes = {
 		DefaultBatteryManagerModule.class,
 		DefaultEventExecutorModule.class,
+		DefaultTaskSchedulerModule.class,
 		DefaultWakefulIoExecutorModule.class,
 		TestDatabaseConfigModule.class,
 		TestPluginConfigModule.class,
-		TestSecureRandomModule.class,
-		TimeTravelModule.class
+		TestSecureRandomModule.class
 })
 public class BrambleCoreIntegrationTestModule {
 
@@ -33,11 +33,6 @@ public class BrambleCoreIntegrationTestModule {
 			public boolean shouldEnableProfilePictures() {
 				return true;
 			}
-
-			@Override
-			public boolean shouldEnableDisappearingMessages() {
-				return true;
-			}
 		};
 	}
 }

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

@@ -38,6 +38,7 @@ import static org.briarproject.bramble.test.TestUtils.getContact;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getMessage;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
+import static org.briarproject.bramble.versioning.ClientVersioningConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_LOCAL;
 import static org.briarproject.bramble.versioning.ClientVersioningConstants.MSG_KEY_UPDATE_VERSION;
 import static org.junit.Assert.assertEquals;
@@ -59,6 +60,8 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 	private final ClientId clientId = getClientId();
 	private final long now = System.currentTimeMillis();
 	private final Transaction txn = new Transaction(null, false);
+	private final BdfDictionary groupMeta = BdfDictionary.of(
+			new BdfEntry(GROUP_KEY_CONTACT_ID, contact.getId().getInt()));
 
 	private ClientVersioningManagerImpl createInstance() {
 		context.checking(new Expectations() {{
@@ -120,8 +123,8 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).addGroup(txn, contactGroup);
 			oneOf(db).setGroupVisibility(txn, contact.getId(),
 					contactGroup.getId(), SHARED);
-			oneOf(clientHelper).setContactId(txn, contactGroup.getId(),
-					contact.getId());
+			oneOf(clientHelper).mergeGroupMetadata(txn, contactGroup.getId(),
+					groupMeta);
 			oneOf(clock).currentTimeMillis();
 			will(returnValue(now));
 			oneOf(clientHelper).createMessage(contactGroup.getId(), now,
@@ -457,8 +460,9 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(db).deleteMessage(txn, oldRemoteUpdateId);
 			oneOf(db).deleteMessageMetadata(txn, oldRemoteUpdateId);
 			// Get contact ID
-			oneOf(clientHelper).getContactId(txn, contactGroup.getId());
-			will(returnValue(contact.getId()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			// No states or visibilities have changed
 		}});
 
@@ -488,9 +492,10 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			// Load the latest local update
 			oneOf(clientHelper).getMessageAsList(txn, oldLocalUpdateId);
 			will(returnValue(oldLocalUpdateBody));
-			// Get contact ID
-			oneOf(clientHelper).getContactId(txn, contactGroup.getId());
-			will(returnValue(contact.getId()));
+			// Get client ID
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			// No states or visibilities have changed
 		}});
 
@@ -541,6 +546,8 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 		BdfDictionary newLocalUpdateMeta = BdfDictionary.of(
 				new BdfEntry(MSG_KEY_UPDATE_VERSION, 2L),
 				new BdfEntry(MSG_KEY_LOCAL, true));
+		BdfDictionary groupMeta = BdfDictionary.of(
+				new BdfEntry(GROUP_KEY_CONTACT_ID, contact.getId().getInt()));
 
 		context.checking(new Expectations() {{
 			oneOf(clientHelper).toList(newRemoteUpdate);
@@ -570,8 +577,9 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(clientHelper).addLocalMessage(txn, newLocalUpdate,
 					newLocalUpdateMeta, true, false);
 			// The client's visibility has changed
-			oneOf(clientHelper).getContactId(txn, contactGroup.getId());
-			will(returnValue(contact.getId()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			oneOf(db).getContact(txn, contact.getId());
 			will(returnValue(contact));
 			oneOf(hook).onClientVisibilityChanging(txn, contact, visibility);
@@ -611,6 +619,8 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 		BdfDictionary newLocalUpdateMeta = BdfDictionary.of(
 				new BdfEntry(MSG_KEY_UPDATE_VERSION, 2L),
 				new BdfEntry(MSG_KEY_LOCAL, true));
+		BdfDictionary groupMeta = BdfDictionary.of(
+				new BdfEntry(GROUP_KEY_CONTACT_ID, contact.getId().getInt()));
 
 		context.checking(new Expectations() {{
 			oneOf(clientHelper).toList(newRemoteUpdate);
@@ -640,8 +650,9 @@ public class ClientVersioningManagerImplTest extends BrambleMockTestCase {
 			oneOf(clientHelper).addLocalMessage(txn, newLocalUpdate,
 					newLocalUpdateMeta, true, false);
 			// The client's visibility has changed
-			oneOf(clientHelper).getContactId(txn, contactGroup.getId());
-			will(returnValue(contact.getId()));
+			oneOf(clientHelper).getGroupMetadataAsDictionary(txn,
+					contactGroup.getId());
+			will(returnValue(groupMeta));
 			oneOf(db).getContact(txn, contact.getId());
 			will(returnValue(contact));
 			oneOf(hook).onClientVisibilityChanging(txn, contact, INVISIBLE);

bramble-core/witness.gradle

@@ -1,6 +1,7 @@
 dependencyVerification {
     verify = [
-        'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+        'cglib:cglib:3.2.8:cglib-3.2.8.jar:3f64de999ecc5595dc84ca8ff0879d8a34c8623f9ef3c517a53ed59023fcb9db',
+        'com.google.code.findbugs:annotations:3.0.1:annotations-3.0.1.jar:6b47ff0a6de0ce17cbedc3abb0828ca5bce3009d53ea47b3723ff023c4742f79',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
         'com.google.dagger:dagger-compiler:2.24:dagger-compiler-2.24.jar:3c5afb955fb188da485cb2c048eff37dce0e1530b9780a0f2f7187d16d1ccc1f',
         'com.google.dagger:dagger-producers:2.24:dagger-producers-2.24.jar:f10f45b95191954d5d6b043fca9e62fb621d21bf70634b8f8476c7988b504c3a',
@@ -19,11 +20,12 @@ dependencyVerification {
         'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.12:junit-4.12.jar:59721f0805e223d84b90677887d9ff567dc534d7c502ca903c0c2b17f05c116a',
+        'net.bytebuddy:byte-buddy:1.9.12:byte-buddy-1.9.12.jar:3688c3d434bebc3edc5516296a2ed0f47b65e451071b4afecad84f902f0efc11',
         'net.i2p.crypto:eddsa:0.2.0:eddsa-0.2.0.jar:a7cb1b85c16e2f0730b9204106929a1d9aaae1df728adc7041a8b8b605692140',
+        'net.jcip:jcip-annotations:1.0:jcip-annotations-1.0.jar:be5805392060c71474bf6c9a67a099471274d30b83eef84bfc4e0889a4f1dcc0',
+        'net.jodah:concurrentunit:0.4.2:concurrentunit-0.4.2.jar:5583078e1acf91734939e985bc9e7ee947b0e93a8eef679da6bb07bbeb47ced3',
         'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
-        'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
-        'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
-        'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
+        'org.apache-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
         'org.bitlet:weupnp:0.1.4:weupnp-0.1.4.jar:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
         'org.briarproject:jtorctl:0.3:jtorctl-0.3.jar:f2939238a097898998432effe93b0334d97a787972ab3a91a8973a1d309fc864',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
@@ -32,16 +34,18 @@ dependencyVerification {
         'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',
         'org.codehaus.mojo:animal-sniffer-ant-tasks:1.16:animal-sniffer-ant-tasks-1.16.jar:890040976fbe2d584619a6a61b1fd2e925b3b5eb342a85eb2762c467c0d64e90',
         'org.codehaus.mojo:animal-sniffer:1.16:animal-sniffer-1.16.jar:72be8bcc226ba43b937c722a08a07852bfa1b11400089265d5df0ee7b38b1d52',
-        'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
-        'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
+        'org.hamcrest:hamcrest-core:2.1:hamcrest-core-2.1.jar:e09109e54a289d88506b9bfec987ddd199f4217c9464132668351b9a4f00bee9',
+        'org.hamcrest:hamcrest-library:2.1:hamcrest-library-2.1.jar:b7e2b6895b3b679f0e47b6380fda391b225e9b78505db9d8bdde8d3cc8d52a21',
+        'org.hamcrest:hamcrest:2.1:hamcrest-2.1.jar:ba93b2e3a562322ba432f0a1b53addcc55cb188253319a020ed77f824e692050',
         'org.hsqldb:hsqldb:2.3.5:hsqldb-2.3.5.jar:6676a6977ac98997a80f827ddbd3fe8ca1e0853dad1492512135fd1a222ccfad',
-        'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
-        'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
-        'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
-        'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
-        'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
+        'org.jmock:jmock-imposters:2.12.0:jmock-imposters-2.12.0.jar:3b836269745a137c9b2347e8d7c2104845b126ef04f012d6bfd94f1a7dea7b09',
+        'org.jmock:jmock-junit4:2.12.0:jmock-junit4-2.12.0.jar:3233062fc889637c151a24f1ee086bad04321ab7d8264fef279daff0fa27205b',
+        'org.jmock:jmock-legacy:2.12.0:jmock-legacy-2.12.0.jar:dea3a9cca653d082e2fe7e40232e982fe03a9984c7d67ceff24f3e03fe580dcd',
+        'org.jmock:jmock-testjar:2.12.0:jmock-testjar-2.12.0.jar:efefbcf6cd294d0e29f0c46eb2a3380d4ca4e1763ff719c69e2f2ac62f564a04',
+        '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:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
+        'org.ow2.asm:asm:7.1:asm-7.1.jar:4ab2fa2b6d2cc9ccb1eaa05ea329c407b47b13ed2915f62f8c4b8cc96258d4de',
         'org.whispersystems:curve25519-java:0.5.0:curve25519-java-0.5.0.jar:0aadd43cf01d11e9b58f867b3c4f25c3194e8b0623d1953d32dfbfbee009e38d',
     ]
 }

bramble-java/build.gradle

@@ -16,17 +16,16 @@ dependencies {
 	implementation fileTree(dir: 'libs', include: '*.jar')
 	implementation 'net.java.dev.jna:jna:4.5.2'
 	implementation 'net.java.dev.jna:jna-platform:4.5.2'
-	tor 'org.briarproject:tor:0.3.5.13@zip'
+	tor 'org.briarproject:tor:0.3.5.13-1@zip'
 	tor 'org.briarproject:obfs4proxy:0.0.12-dev-40245c4a@zip'
 
 	annotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 
 	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
 	testImplementation project(path: ':bramble-core', configuration: 'testOutput')
-	testImplementation 'junit:junit:4.12'
-	testImplementation "org.jmock:jmock:2.8.2"
-	testImplementation "org.jmock:jmock-junit4:2.8.2"
-	testImplementation "org.jmock:jmock-legacy:2.8.2"
+	testImplementation "junit:junit:$junit_version"
+	testImplementation "org.jmock:jmock:$jmock_version"
+	testImplementation "org.jmock:jmock-junit4:$jmock_version"
 
 	testAnnotationProcessor 'com.google.dagger:dagger-compiler:2.24'
 }

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

@@ -8,9 +8,9 @@ import org.briarproject.bramble.system.JavaSystemModule;
 import dagger.Module;
 
 @Module(includes = {
-		CircumventionModule.class,
 		JavaNetworkModule.class,
 		JavaSystemModule.class,
+		CircumventionModule.class,
 		SocksModule.class
 })
 public class BrambleJavaModule {

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

@@ -25,6 +25,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 import javax.net.SocketFactory;
 
+import static java.util.logging.Level.INFO;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.util.OsUtils.isLinux;
 
@@ -96,8 +97,15 @@ public class UnixTorPluginFactory implements DuplexPluginFactory {
 		String architecture = null;
 		if (isLinux()) {
 			String arch = System.getProperty("os.arch");
+			if (LOG.isLoggable(INFO)) {
+				LOG.info("System's os.arch is " + arch);
+			}
 			if (arch.equals("amd64")) {
 				architecture = "linux-x86_64";
+			} else if (arch.equals("aarch64")) {
+				architecture = "linux-aarch64";
+			} else if (arch.equals("arm")) {
+				architecture = "linux-armhf";
 			}
 		}
 		if (architecture == null) {
@@ -105,6 +113,10 @@ public class UnixTorPluginFactory implements DuplexPluginFactory {
 			return null;
 		}
 
+		if (LOG.isLoggable(INFO)) {
+			LOG.info("The selected architecture for Tor is " + architecture);
+		}
+
 		Backoff backoff = backoffFactory.createBackoff(MIN_POLLING_INTERVAL,
 				MAX_POLLING_INTERVAL, BACKOFF_BASE);
 		TorRendezvousCrypto torRendezvousCrypto = new TorRendezvousCryptoImpl();

bramble-java/witness.gradle

@@ -1,6 +1,7 @@
 dependencyVerification {
     verify = [
-        'cglib:cglib:3.2.0:cglib-3.2.0.jar:adb13bab79712ad6bdf1bd59f2a3918018a8016e722e8a357065afb9e6690861',
+        'cglib:cglib:3.2.8:cglib-3.2.8.jar:3f64de999ecc5595dc84ca8ff0879d8a34c8623f9ef3c517a53ed59023fcb9db',
+        'com.google.code.findbugs:annotations:3.0.1:annotations-3.0.1.jar:6b47ff0a6de0ce17cbedc3abb0828ca5bce3009d53ea47b3723ff023c4742f79',
         'com.google.code.findbugs:jsr305:3.0.2:jsr305-3.0.2.jar:766ad2a0783f2687962c8ad74ceecc38a28b9f72a2d085ee438b7813e928d0c7',
         'com.google.dagger:dagger-compiler:2.24:dagger-compiler-2.24.jar:3c5afb955fb188da485cb2c048eff37dce0e1530b9780a0f2f7187d16d1ccc1f',
         'com.google.dagger:dagger-producers:2.24:dagger-producers-2.24.jar:f10f45b95191954d5d6b043fca9e62fb621d21bf70634b8f8476c7988b504c3a',
@@ -17,24 +18,26 @@ dependencyVerification {
         'javax.annotation:jsr250-api:1.0:jsr250-api-1.0.jar:a1a922d0d9b6d183ed3800dfac01d1e1eb159f0e8c6f94736931c1def54a941f',
         'javax.inject:javax.inject:1:javax.inject-1.jar:91c77044a50c481636c32d916fd89c9118a72195390452c81065080f957de7ff',
         'junit:junit:4.12: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:4.5.2:jna-platform-4.5.2.jar:f1d00c167d8921c6e23c626ef9f1c3ae0be473c95c68ffa012bc7ae55a87e2d6',
         'net.java.dev.jna:jna:4.5.2:jna-4.5.2.jar:0c8eb7acf67261656d79005191debaba3b6bf5dd60a43735a245429381dbecff',
+        'net.jcip:jcip-annotations:1.0:jcip-annotations-1.0.jar:be5805392060c71474bf6c9a67a099471274d30b83eef84bfc4e0889a4f1dcc0',
         'net.ltgt.gradle.incap:incap:0.2:incap-0.2.jar:b625b9806b0f1e4bc7a2e3457119488de3cd57ea20feedd513db070a573a4ffd',
-        'org.apache.ant:ant-launcher:1.9.4:ant-launcher-1.9.4.jar:7bccea20b41801ca17bcbc909a78c835d0f443f12d639c77bd6ae3d05861608d',
-        'org.apache.ant:ant:1.9.4:ant-1.9.4.jar:649ae0730251de07b8913f49286d46bba7b92d47c5f332610aa426c4f02161d8',
-        'org.beanshell:bsh:1.3.0:bsh-1.3.0.jar:9b04edc75d19db54f1b4e8b5355e9364384c6cf71eb0a1b9724c159d779879f8',
+        'org.apache-extras.beanshell:bsh:2.0b6:bsh-2.0b6.jar:a17955976070c0573235ee662f2794a78082758b61accffce8d3f8aedcd91047',
         'org.briarproject:obfs4proxy:0.0.12-dev-40245c4a:obfs4proxy-0.0.12-dev-40245c4a.zip:172029e7058b3a83ac93ac4991a44bf76e16ce8d46f558f5836d57da3cb3a766',
-        'org.briarproject:tor:0.3.5.13:tor-0.3.5.13.zip:1c5f0b821ee2aadb0ea04aa96caab3ca0a08370cce8de81c2dfe04d172f8a2a0',
+        'org.briarproject:tor:0.3.5.13-1:tor-0.3.5.13-1.zip:ef35c16bf8dc1f4c75ed71d9f55e4514f383d124ec96b859aca647c990927c99',
         'org.checkerframework:checker-compat-qual:2.5.3:checker-compat-qual-2.5.3.jar:d76b9afea61c7c082908023f0cbc1427fab9abd2df915c8b8a3e7a509bccbc6d',
         'org.checkerframework:checker-qual:2.5.2:checker-qual-2.5.2.jar:64b02691c8b9d4e7700f8ee2e742dce7ea2c6e81e662b7522c9ee3bf568c040a',
         'org.codehaus.mojo:animal-sniffer-annotations:1.17:animal-sniffer-annotations-1.17.jar:92654f493ecfec52082e76354f0ebf87648dc3d5cec2e3c3cdb947c016747a53',
-        'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
-        'org.hamcrest:hamcrest-library:1.3:hamcrest-library-1.3.jar:711d64522f9ec410983bd310934296da134be4254a125080a0416ec178dfad1c',
-        'org.jmock:jmock-junit4:2.8.2:jmock-junit4-2.8.2.jar:f7ee4df4f7bd7b7f1cafad3b99eb74d579f109d5992ff625347352edb55e674c',
-        'org.jmock:jmock-legacy:2.8.2:jmock-legacy-2.8.2.jar:f2b985a5c08a9edb7f37612330c058809da3f6a6d63ce792426ebf8ff0d6d31b',
-        'org.jmock:jmock-testjar:2.8.2:jmock-testjar-2.8.2.jar:8900860f72c474e027cf97fe78dcbf154a1aa7fc62b6845c5fb4e4f3c7bc8760',
-        'org.jmock:jmock:2.8.2:jmock-2.8.2.jar:6c73cb4a2e6dbfb61fd99c9a768539c170ab6568e57846bd60dbf19596b65b16',
-        'org.objenesis:objenesis:2.1:objenesis-2.1.jar:c74330cc6b806c804fd37e74487b4fe5d7c2750c5e15fbc6efa13bdee1bdef80',
-        'org.ow2.asm:asm:5.0.4:asm-5.0.4.jar:896618ed8ae62702521a78bc7be42b7c491a08e6920a15f89a3ecdec31e9a220',
+        'org.hamcrest:hamcrest-core:2.1:hamcrest-core-2.1.jar:e09109e54a289d88506b9bfec987ddd199f4217c9464132668351b9a4f00bee9',
+        'org.hamcrest:hamcrest-library:2.1:hamcrest-library-2.1.jar:b7e2b6895b3b679f0e47b6380fda391b225e9b78505db9d8bdde8d3cc8d52a21',
+        'org.hamcrest:hamcrest:2.1:hamcrest-2.1.jar:ba93b2e3a562322ba432f0a1b53addcc55cb188253319a020ed77f824e692050',
+        'org.jmock:jmock-imposters:2.12.0:jmock-imposters-2.12.0.jar:3b836269745a137c9b2347e8d7c2104845b126ef04f012d6bfd94f1a7dea7b09',
+        'org.jmock:jmock-junit4:2.12.0:jmock-junit4-2.12.0.jar:3233062fc889637c151a24f1ee086bad04321ab7d8264fef279daff0fa27205b',
+        'org.jmock:jmock-legacy:2.12.0:jmock-legacy-2.12.0.jar:dea3a9cca653d082e2fe7e40232e982fe03a9984c7d67ceff24f3e03fe580dcd',
+        'org.jmock:jmock-testjar:2.12.0:jmock-testjar-2.12.0.jar:efefbcf6cd294d0e29f0c46eb2a3380d4ca4e1763ff719c69e2f2ac62f564a04',
+        'org.jmock:jmock:2.12.0:jmock-2.12.0.jar:266d07314c0cd343c46ff8a55601272de8cf406807caf55e6f313295f83d10be',
+        'org.objenesis:objenesis:3.0.1:objenesis-3.0.1.jar:7a8ff780b9ff48415d7c705f60030b0acaa616e7f823c98eede3b63508d4e984',
+        'org.ow2.asm:asm:7.1:asm-7.1.jar:4ab2fa2b6d2cc9ccb1eaa05ea329c407b47b13ed2915f62f8c4b8cc96258d4de',
     ]
 }

briar-android/build.gradle

@@ -19,12 +19,16 @@ android {
 	compileSdkVersion 30
 	buildToolsVersion '30.0.2'
 
+	packagingOptions {
+		doNotStrip '**/*.so'
+	}
+
 	defaultConfig {
 		minSdkVersion 16
 		targetSdkVersion 29
-		versionCode 10216
-		versionName "1.2.16"
-		applicationId "org.briarproject.briar.android"
+		versionCode 10218
+		versionName "1.2.18"
+		applicationId "org.briarproject.briar.socialbackup"
 
 		vectorDrawables.useSupportLibrary = true
 		buildConfigField "String", "GitHash",
@@ -102,6 +106,7 @@ dependencies {
 	implementation 'androidx.constraintlayout:constraintlayout:2.0.4'
 	implementation 'com.google.android.material:material:1.2.1'
 	implementation 'androidx.recyclerview:recyclerview-selection:1.1.0-rc03'
+	implementation 'org.magmacollective.darkcrystal:dark-crystal-secret-sharing-wrapper:1.1.0'
 
 	implementation 'info.guardianproject.panic:panic:1.0'
 	implementation 'info.guardianproject.trustedintents:trustedintents:0.2'
@@ -132,11 +137,12 @@ dependencies {
 	testImplementation "androidx.arch.core:core-testing:2.1.0"
 	testImplementation "androidx.test.espresso:espresso-core:$espressoVersion"
 	testImplementation 'org.robolectric:robolectric:4.3.1'
-	testImplementation 'org.mockito:mockito-core:3.1.0'
-	testImplementation 'junit:junit:4.13.1'
-	testImplementation "org.jmock:jmock:$jmockVersion"
-	testImplementation "org.jmock:jmock-junit4:$jmockVersion"
-	testImplementation "org.jmock:jmock-legacy:$jmockVersion"
+
+	testImplementation 'org.mockito:mockito-core:3.9.0'
+	testImplementation "junit:junit:$junit_version"
+	testImplementation "org.jmock:jmock:$jmock_version"
+	testImplementation "org.jmock:jmock-junit4:$jmock_version"
+	testImplementation "org.jmock:jmock-imposters:$jmock_version"
 	testAnnotationProcessor "com.google.dagger:dagger-compiler:2.24"
 
 	androidTestImplementation project(path: ':bramble-api', configuration: 'testOutput')

briar-android/proguard-rules.txt

@@ -40,3 +40,5 @@
 
 # Dependency injection annotations, needed for UI tests on older API levels
 -keep class javax.inject.**
+
+-keep class com.sun.jna.** { *; }

briar-android/src/androidTestOfficial/java/org/briarproject/briar/android/BriarUiTestComponent.java

@@ -3,7 +3,6 @@ package org.briarproject.briar.android;
 import org.briarproject.bramble.BrambleAndroidModule;
 import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.account.BriarAccountModule;
-import org.briarproject.bramble.system.ClockModule;
 import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.attachment.AttachmentModule;
 import org.briarproject.briar.android.attachment.media.MediaModule;
@@ -17,7 +16,6 @@ import dagger.Component;
 @Component(modules = {
 		AppModule.class,
 		AttachmentModule.class,
-		ClockModule.class,
 		MediaModule.class,
 		BriarCoreModule.class,
 		BrambleAndroidModule.class,

briar-android/src/androidTestScreenshot/java/org/briarproject/briar/android/BriarUiTestComponent.java

@@ -3,7 +3,6 @@ package org.briarproject.briar.android;
 import org.briarproject.bramble.BrambleAndroidModule;
 import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.account.BriarAccountModule;
-import org.briarproject.bramble.system.ClockModule;
 import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.attachment.AttachmentModule;
 import org.briarproject.briar.android.attachment.media.MediaModule;
@@ -18,7 +17,6 @@ import dagger.Component;
 @Component(modules = {
 		AppModule.class,
 		AttachmentModule.class,
-		ClockModule.class,
 		MediaModule.class,
 		BriarCoreModule.class,
 		BrambleAndroidModule.class,

briar-android/src/debug/res/values/strings.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-	<string name="app_name" translatable="false">Briar Debug</string>
-	<string name="app_package" translatable="false">org.briarproject.briar.android.debug</string>
+	<string name="app_name" translatable="false">Briar SB Debug</string>
+	<string name="app_package" translatable="false">org.briarproject.briar.socialbackup.debug</string>
 </resources>

briar-android/src/main/AndroidManifest.xml

@@ -27,7 +27,10 @@
 	<uses-permission android:name="android.permission.USE_FINGERPRINT" />
 	<uses-permission android:name="android.permission.VIBRATE" />
 	<uses-permission android:name="android.permission.WAKE_LOCK" />
-	<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+	<uses-permission
+		android:name="android.permission.WRITE_EXTERNAL_STORAGE"
+		android:maxSdkVersion="18"
+		tools:ignore="ScopedStorage" />
 
 	<uses-permission-sdk-23 android:name="android.permission.ACCESS_FINE_LOCATION" />
 	<uses-permission-sdk-23 android:name="android.permission.REQUEST_IGNORE_BATTERY_OPTIMIZATIONS" />
@@ -38,6 +41,7 @@
 		android:name="org.briarproject.briar.android.BriarApplicationImpl"
 		android:allowBackup="false"
 		android:banner="@mipmap/tv_banner"
+		android:fullBackupContent="@xml/backup_rules"
 		android:icon="@mipmap/ic_launcher_round"
 		android:label="@string/app_name"
 		android:logo="@mipmap/ic_launcher_round"
@@ -134,6 +138,51 @@
 			</intent-filter>
 		</activity>
 
+		<activity
+			android:name="org.briarproject.briar.android.account.NewOrRecoverActivity"
+			android:label="@string/activity_name_new_or_recover_account"
+			android:parentActivityName="org.briarproject.briar.android.login.StartupActivity">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value="org.briarproject.briar.android.login.StartupActivity" />
+		</activity>
+
+		<activity
+			android:name="org.briarproject.briar.android.socialbackup.DistributedBackupActivity"
+			android:label="@string/activity_name_distributed_backup"
+			android:parentActivityName="org.briarproject.briar.android.settings.SettingsActivity">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value="org.briarproject.briar.android.settings.SettingsActivity" />
+		</activity>
+
+		<activity
+			android:name="org.briarproject.briar.android.socialbackup.recover.CustodianReturnShardActivity"
+			android:label="@string/activity_name_custodian_help_recovery"
+			android:parentActivityName="org.briarproject.briar.android.conversation.ConversationActivity">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value="org.briarproject.briar.android.conversation.ConversationActivity" />
+		</activity>
+
+		<activity
+			android:name="org.briarproject.briar.android.socialbackup.recover.OwnerReturnShardActivity"
+			android:label="@string/activity_name_recovery"
+			android:parentActivityName="org.briarproject.briar.android.account.NewOrRecoverActivity">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value="org.briarproject.briar.android.account.NewOrRecoverActivity" />
+		</activity>
+
+		<activity
+			android:name="org.briarproject.briar.android.socialbackup.recover.RestoreAccountActivity"
+			android:label="@string/activity_name_restore_account"
+			android:parentActivityName="org.briarproject.briar.android.socialbackup.recover.OwnerReturnShardActivity">
+			<meta-data
+				android:name="android.support.PARENT_ACTIVITY"
+				android:value="org.briarproject.briar.android.socialbackup.recover.OwnerReturnShardActivity" />
+		</activity>
+
 		<activity
 			android:name="org.briarproject.briar.android.conversation.ConversationActivity"
 			android:label="@string/app_name"
@@ -338,7 +387,7 @@
 		</activity>
 
 		<activity
-			android:name="org.briarproject.briar.android.keyagreement.ContactExchangeActivity"
+			android:name="org.briarproject.briar.android.contact.add.nearby.AddNearbyContactActivity"
 			android:label="@string/add_contact_title"
 			android:parentActivityName="org.briarproject.briar.android.navdrawer.NavDrawerActivity"
 			android:theme="@style/BriarTheme.NoActionBar">

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

@@ -8,11 +8,13 @@ import org.briarproject.bramble.BrambleCoreModule;
 import org.briarproject.bramble.account.BriarAccountModule;
 import org.briarproject.bramble.api.FeatureFlags;
 import org.briarproject.bramble.api.account.AccountManager;
+import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.connection.ConnectionRegistry;
 import org.briarproject.bramble.api.contact.ContactExchangeManager;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.crypto.CryptoExecutor;
 import org.briarproject.bramble.api.crypto.PasswordStrengthEstimator;
+import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DatabaseExecutor;
 import org.briarproject.bramble.api.db.TransactionManager;
 import org.briarproject.bramble.api.event.EventBus;
@@ -29,7 +31,6 @@ import org.briarproject.bramble.api.system.AndroidWakeLockManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.system.LocationUtils;
 import org.briarproject.bramble.plugin.tor.CircumventionProvider;
-import org.briarproject.bramble.system.ClockModule;
 import org.briarproject.briar.BriarCoreEagerSingletons;
 import org.briarproject.briar.BriarCoreModule;
 import org.briarproject.briar.android.attachment.AttachmentModule;
@@ -43,7 +44,6 @@ import org.briarproject.briar.api.android.DozeWatchdog;
 import org.briarproject.briar.api.android.LockManager;
 import org.briarproject.briar.api.android.ScreenFilterMonitor;
 import org.briarproject.briar.api.attachment.AttachmentReader;
-import org.briarproject.briar.api.autodelete.AutoDeleteManager;
 import org.briarproject.briar.api.blog.BlogManager;
 import org.briarproject.briar.api.blog.BlogPostFactory;
 import org.briarproject.briar.api.blog.BlogSharingManager;
@@ -61,6 +61,7 @@ import org.briarproject.briar.api.privategroup.PrivateGroupFactory;
 import org.briarproject.briar.api.privategroup.PrivateGroupManager;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationFactory;
 import org.briarproject.briar.api.privategroup.invitation.GroupInvitationManager;
+import org.briarproject.briar.api.socialbackup.SocialBackupManager;
 import org.briarproject.briar.api.test.TestDataCreator;
 
 import java.util.concurrent.Executor;
@@ -78,7 +79,6 @@ import dagger.Component;
 		BriarAccountModule.class,
 		AppModule.class,
 		AttachmentModule.class,
-		ClockModule.class,
 		MediaModule.class
 })
 public interface AndroidComponent
@@ -187,7 +187,11 @@ public interface AndroidComponent
 
 	Thread.UncaughtExceptionHandler exceptionHandler();
 
-	AutoDeleteManager autoDeleteManager();
+	SocialBackupManager socialBackupManager();
+
+    DatabaseComponent databaseComponent();
+
+    ClientHelper clientHelper();
 
 	void inject(SignInReminderReceiver briarService);
 

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

@@ -37,7 +37,6 @@ import org.briarproject.briar.android.splash.SplashScreenActivity;
 import org.briarproject.briar.android.util.BriarNotificationBuilder;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
 import org.briarproject.briar.api.blog.event.BlogPostAddedEvent;
-import org.briarproject.briar.api.conversation.ConversationResponse;
 import org.briarproject.briar.api.conversation.event.ConversationMessageReceivedEvent;
 import org.briarproject.briar.api.forum.event.ForumPostReceivedEvent;
 import org.briarproject.briar.api.privategroup.event.GroupMessageAddedEvent;
@@ -227,12 +226,6 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		} else if (e instanceof ConversationMessageReceivedEvent) {
 			ConversationMessageReceivedEvent<?> p =
 					(ConversationMessageReceivedEvent<?>) e;
-			if (p.getMessageHeader() instanceof ConversationResponse) {
-				ConversationResponse r =
-						(ConversationResponse) p.getMessageHeader();
-				// don't show notification for own auto-decline responses
-				if (r.isAutoDecline()) return;
-			}
 			showContactNotification(p.getContactId());
 		} else if (e instanceof GroupMessageAddedEvent) {
 			GroupMessageAddedEvent g = (GroupMessageAddedEvent) e;

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

@@ -31,8 +31,9 @@ import org.briarproject.briar.android.account.DozeHelperModule;
 import org.briarproject.briar.android.account.LockManagerImpl;
 import org.briarproject.briar.android.account.SetupModule;
 import org.briarproject.briar.android.contact.ContactListModule;
+import org.briarproject.briar.android.contact.add.nearby.AddNearbyContactModule;
 import org.briarproject.briar.android.forum.ForumModule;
-import org.briarproject.briar.android.keyagreement.ContactExchangeModule;
+import org.briarproject.briar.android.introduction.IntroductionModule;
 import org.briarproject.briar.android.logging.LoggingModule;
 import org.briarproject.briar.android.login.LoginModule;
 import org.briarproject.briar.android.navdrawer.NavDrawerModule;
@@ -41,6 +42,8 @@ import org.briarproject.briar.android.privategroup.list.GroupListModule;
 import org.briarproject.briar.android.reporting.DevReportModule;
 import org.briarproject.briar.android.settings.SettingsModule;
 import org.briarproject.briar.android.sharing.SharingModule;
+import org.briarproject.briar.android.socialbackup.recover.CustodianReturnShardModule;
+import org.briarproject.briar.android.socialbackup.recover.OwnerReturnShardModule;
 import org.briarproject.briar.android.test.TestAvatarCreatorImpl;
 import org.briarproject.briar.android.viewmodel.ViewModelModule;
 import org.briarproject.briar.api.android.AndroidNotificationManager;
@@ -48,6 +51,7 @@ import org.briarproject.briar.api.android.DozeWatchdog;
 import org.briarproject.briar.api.android.LockManager;
 import org.briarproject.briar.api.android.ScreenFilterMonitor;
 import org.briarproject.briar.api.test.TestAvatarCreator;
+import org.briarproject.briar.socialbackup.AndroidDarkCrystalModule;
 
 import java.io.File;
 import java.security.GeneralSecurityException;
@@ -74,7 +78,7 @@ import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 @Module(includes = {
 		SetupModule.class,
 		DozeHelperModule.class,
-		ContactExchangeModule.class,
+		AddNearbyContactModule.class,
 		LoggingModule.class,
 		LoginModule.class,
 		NavDrawerModule.class,
@@ -82,11 +86,15 @@ import static org.briarproject.briar.android.TestingConstants.IS_DEBUG_BUILD;
 		SettingsModule.class,
 		DevReportModule.class,
 		ContactListModule.class,
+		AndroidDarkCrystalModule.class,
+		IntroductionModule.class,
 		// below need to be within same scope as ViewModelProvider.Factory
 		ForumModule.class,
 		GroupListModule.class,
 		GroupConversationModule.class,
 		SharingModule.class,
+		OwnerReturnShardModule.class,
+		CustodianReturnShardModule.class
 })
 public class AppModule {
 
@@ -283,11 +291,6 @@ public class AppModule {
 			public boolean shouldEnableProfilePictures() {
 				return IS_DEBUG_BUILD;
 			}
-
-			@Override
-			public boolean shouldEnableDisappearingMessages() {
-				return IS_DEBUG_BUILD;
-			}
 		};
 	}
 }

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

@@ -33,7 +33,6 @@ public class DozeFragment extends SetupFragment
 	private DozeView dozeView;
 	private HuaweiView huaweiView;
 	private Button next;
-	private ProgressBar progressBar;
 	private boolean secondAttempt = false;
 
 	public static DozeFragment newInstance() {
@@ -58,11 +57,19 @@ public class DozeFragment extends SetupFragment
 		huaweiView = v.findViewById(R.id.huaweiView);
 		huaweiView.setOnCheckedChangedListener(this);
 		next = v.findViewById(R.id.next);
-		progressBar = v.findViewById(R.id.progress);
+		ProgressBar progressBar = v.findViewById(R.id.progress);
 
 		dozeView.setOnButtonClickListener(this::askForDozeWhitelisting);
 		next.setOnClickListener(this);
 
+		viewModel.getIsCreatingAccount()
+				.observe(getViewLifecycleOwner(), isCreatingAccount -> {
+					if (isCreatingAccount) {
+						next.setVisibility(INVISIBLE);
+						progressBar.setVisibility(VISIBLE);
+					}
+				});
+
 		return v;
 	}
 
@@ -104,15 +111,6 @@ public class DozeFragment extends SetupFragment
 
 	@Override
 	public void onClick(View view) {
-		setNextClicked();
 		viewModel.dozeExceptionConfirmed();
 	}
-
-	@Override
-	void setNextClicked() {
-		super.setNextClicked();
-
-		next.setVisibility(INVISIBLE);
-		progressBar.setVisibility(VISIBLE);
-	}
 }

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

@@ -2,7 +2,7 @@ package org.briarproject.briar.android.account;
 
 import android.content.Context;
 
-interface DozeHelper {
+public interface DozeHelper {
 
 	boolean needToShowDozeFragment(Context context);
 }

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

@@ -14,7 +14,7 @@ import static org.briarproject.briar.android.util.UiUtils.needsDozeWhitelisting;
 
 @UiThread
 @NotNullByDefault
-class DozeView extends PowerView {
+public class DozeView extends PowerView {
 
 	@Nullable
 	private Runnable onButtonClickListener;