Merge branch '1802-sync-via-removable-storage' into offline-testing

# Conflicts:
#	bramble-api/src/main/java/org/briarproject/bramble/api/FeatureFlags.java
#	bramble-core/build.gradle
#	bramble-core/src/test/java/org/briarproject/bramble/test/BrambleCoreIntegrationTestModule.java
#	bramble-core/witness.gradle
#	bramble-java/src/main/java/org/briarproject/bramble/plugin/tor/UnixTorPluginFactory.java
#	briar-android/src/main/java/org/briarproject/briar/android/AndroidComponent.java
#	briar-android/src/main/java/org/briarproject/briar/android/AppModule.java
#	briar-android/src/main/java/org/briarproject/briar/android/activity/ActivityComponent.java
#	briar-android/src/main/java/org/briarproject/briar/android/util/UiUtils.java
#	briar-android/src/main/res/values/strings.xml
#	briar-headless/src/main/java/org/briarproject/briar/headless/HeadlessModule.kt
#	briar-headless/src/test/java/org/briarproject/briar/headless/HeadlessTestModule.kt

briar-core/src/main/java/org/briarproject/briar/avatar/AvatarManagerImpl.java

@@ -40,6 +40,7 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
 import static org.briarproject.briar.api.attachment.MediaConstants.MSG_KEY_CONTENT_TYPE;
 import static org.briarproject.briar.avatar.AvatarConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.briar.avatar.AvatarConstants.MSG_KEY_VERSION;
@@ -124,8 +125,8 @@ class AvatarManagerImpl implements AvatarManager, OpenDatabaseHook, ContactHook,
 	}
 
 	@Override
-	public boolean incomingMessage(Transaction txn, Message m, Metadata meta)
-			throws DbException, InvalidMessageException {
+	public DeliveryAction incomingMessage(Transaction txn, Message m,
+			Metadata meta) throws DbException, InvalidMessageException {
 		Group ourGroup = getOurGroup(txn);
 		if (m.getGroupId().equals(ourGroup.getId())) {
 			throw new InvalidMessageException(
@@ -144,7 +145,7 @@ class AvatarManagerImpl implements AvatarManager, OpenDatabaseHook, ContactHook,
 					// We've already received a newer update - delete this one
 					db.deleteMessage(txn, m.getId());
 					db.deleteMessageMetadata(txn, m.getId());
-					return false; // don't broadcast update
+					return ACCEPT_DO_NOT_SHARE;
 				}
 			}
 			ContactId contactId = getContactId(txn, m.getGroupId());
@@ -155,7 +156,7 @@ class AvatarManagerImpl implements AvatarManager, OpenDatabaseHook, ContactHook,
 		} catch (FormatException e) {
 			throw new InvalidMessageException(e);
 		}
-		return false;
+		return ACCEPT_DO_NOT_SHARE;
 	}
 
 	@Override

briar-core/src/main/java/org/briarproject/briar/blog/BlogManagerImpl.java

@@ -50,6 +50,8 @@ import java.util.concurrent.CopyOnWriteArrayList;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_SHARE;
 import static org.briarproject.briar.api.blog.BlogConstants.KEY_AUTHOR;
 import static org.briarproject.briar.api.blog.BlogConstants.KEY_COMMENT;
 import static org.briarproject.briar.api.blog.BlogConstants.KEY_ORIGINAL_MSG_ID;
@@ -109,8 +111,9 @@ class BlogManagerImpl extends BdfIncomingMessageHook implements BlogManager,
 	}
 
 	@Override
-	protected boolean incomingMessage(Transaction txn, Message m, BdfList list,
-			BdfDictionary meta) throws DbException, FormatException {
+	protected DeliveryAction incomingMessage(Transaction txn, Message m,
+			BdfList list, BdfDictionary meta)
+			throws DbException, FormatException {
 
 		GroupId groupId = m.getGroupId();
 		MessageType type = getMessageType(meta);
@@ -138,7 +141,7 @@ class BlogManagerImpl extends BdfIncomingMessageHook implements BlogManager,
 			txn.attach(event);
 
 			// shares message and its dependencies
-			return true;
+			return ACCEPT_SHARE;
 		} else if (type == WRAPPED_COMMENT) {
 			// Check that the original message ID in the dependency's metadata
 			// matches the original parent ID of the wrapped comment
@@ -153,7 +156,7 @@ class BlogManagerImpl extends BdfIncomingMessageHook implements BlogManager,
 			}
 		}
 		// don't share message until parent arrives
-		return false;
+		return ACCEPT_DO_NOT_SHARE;
 	}
 
 	@Override

briar-core/src/main/java/org/briarproject/briar/forum/ForumManagerImpl.java

@@ -45,6 +45,7 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_SHARE;
 import static org.briarproject.briar.api.forum.ForumConstants.KEY_AUTHOR;
 import static org.briarproject.briar.api.forum.ForumConstants.KEY_LOCAL;
 import static org.briarproject.briar.api.forum.ForumConstants.KEY_PARENT;
@@ -75,8 +76,9 @@ class ForumManagerImpl extends BdfIncomingMessageHook implements ForumManager {
 	}
 
 	@Override
-	protected boolean incomingMessage(Transaction txn, Message m, BdfList body,
-			BdfDictionary meta) throws DbException, FormatException {
+	protected DeliveryAction incomingMessage(Transaction txn, Message m,
+			BdfList body, BdfDictionary meta)
+			throws DbException, FormatException {
 
 		messageTracker.trackIncomingMessage(txn, m);
 
@@ -86,8 +88,7 @@ class ForumManagerImpl extends BdfIncomingMessageHook implements ForumManager {
 				new ForumPostReceivedEvent(m.getGroupId(), header, text);
 		txn.attach(event);
 
-		// share message
-		return true;
+		return ACCEPT_SHARE;
 	}
 
 	@Override

briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeProtocolEngine.java

@@ -4,6 +4,7 @@ import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.client.ContactGroupFactory;
 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.crypto.KeyPair;
 import org.briarproject.bramble.api.crypto.PrivateKey;
@@ -48,6 +49,8 @@ import javax.inject.Inject;
 
 import static java.lang.Math.max;
 import static java.util.logging.Level.WARNING;
+import static org.briarproject.bramble.api.nullsafety.NullSafety.requireNonNull;
+import static org.briarproject.bramble.api.system.Clock.MIN_REASONABLE_TIME_MS;
 import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.briarproject.briar.introduction.IntroduceeState.AWAIT_AUTH;
 import static org.briarproject.briar.introduction.IntroduceeState.AWAIT_RESPONSES;
@@ -154,7 +157,8 @@ class IntroduceeProtocolEngine
 			case REMOTE_ACCEPTED:
 			case AWAIT_AUTH:
 			case AWAIT_ACTIVATE:
-				return abort(txn, session); // Invalid in these states
+				// Invalid in these states
+				return abort(txn, session, m.getMessageId());
 			default:
 				throw new AssertionError();
 		}
@@ -174,7 +178,8 @@ class IntroduceeProtocolEngine
 			case REMOTE_ACCEPTED:
 			case AWAIT_AUTH:
 			case AWAIT_ACTIVATE:
-				return abort(txn, session); // Invalid in these states
+				// Invalid in these states
+				return abort(txn, session, m.getMessageId());
 			default:
 				throw new AssertionError();
 		}
@@ -194,7 +199,8 @@ class IntroduceeProtocolEngine
 			case REMOTE_ACCEPTED:
 			case AWAIT_AUTH:
 			case AWAIT_ACTIVATE:
-				return abort(txn, session); // Invalid in these states
+				// Invalid in these states
+				return abort(txn, session, m.getMessageId());
 			default:
 				throw new AssertionError();
 		}
@@ -213,7 +219,8 @@ class IntroduceeProtocolEngine
 			case LOCAL_ACCEPTED:
 			case REMOTE_ACCEPTED:
 			case AWAIT_ACTIVATE:
-				return abort(txn, session); // Invalid in these states
+				// Invalid in these states
+				return abort(txn, session, m.getMessageId());
 			default:
 				throw new AssertionError();
 		}
@@ -232,7 +239,8 @@ class IntroduceeProtocolEngine
 			case LOCAL_ACCEPTED:
 			case REMOTE_ACCEPTED:
 			case AWAIT_AUTH:
-				return abort(txn, session); // Invalid in these states
+				// Invalid in these states
+				return abort(txn, session, m.getMessageId());
 			default:
 				throw new AssertionError();
 		}
@@ -248,7 +256,7 @@ class IntroduceeProtocolEngine
 			IntroduceeSession s, RequestMessage m) throws DbException {
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 
 		// Mark the request visible in the UI and available to answer
 		markMessageVisibleInUi(txn, m.getMessageId());
@@ -343,10 +351,10 @@ class IntroduceeProtocolEngine
 			IntroduceeSession s, AcceptMessage m) throws DbException {
 		// The timestamp must be higher than the last request message
 		if (m.getTimestamp() <= s.getRequestTimestamp())
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 
 		// Determine next state
 		IntroduceeState state =
@@ -365,10 +373,10 @@ class IntroduceeProtocolEngine
 			IntroduceeSession s, DeclineMessage m) throws DbException {
 		// The timestamp must be higher than the last request message
 		if (m.getTimestamp() <= s.getRequestTimestamp())
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 
 		// Mark the response visible in the UI
 		markMessageVisibleInUi(txn, m.getMessageId());
@@ -398,10 +406,10 @@ class IntroduceeProtocolEngine
 			throws DbException {
 		// The timestamp must be higher than the last request message
 		if (m.getTimestamp() <= s.getRequestTimestamp())
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 
 		// Move to START state
 		return IntroduceeSession.clear(s, START, s.getLastLocalMessageId(),
@@ -423,7 +431,7 @@ class IntroduceeProtocolEngine
 			signature = crypto.sign(ourMacKey, localAuthor.getPrivateKey());
 		} catch (GeneralSecurityException e) {
 			logException(LOG, WARNING, e);
-			return abort(txn, s);
+			return abort(txn, s, s.getLastRemoteMessageId());
 		}
 		if (s.getState() != AWAIT_AUTH) throw new AssertionError();
 		long localTimestamp = getTimestampForInvisibleMessage(s);
@@ -436,42 +444,42 @@ class IntroduceeProtocolEngine
 			IntroduceeSession s, AuthMessage m) throws DbException {
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 
 		LocalAuthor localAuthor = identityManager.getLocalAuthor(txn);
 		try {
 			crypto.verifyAuthMac(m.getMac(), s, localAuthor.getId());
 			crypto.verifySignature(m.getSignature(), s);
 		} catch (GeneralSecurityException e) {
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 		}
 		long timestamp = Math.min(s.getLocal().acceptTimestamp,
 				s.getRemote().acceptTimestamp);
 		if (timestamp == -1) throw new AssertionError();
+		if (timestamp < MIN_REASONABLE_TIME_MS) {
+			LOG.warning("Timestamp is too old");
+			return abort(txn, s, m.getMessageId());
+		}
 
 		Map<TransportId, KeySetId> keys = null;
 		try {
-			contactManager.addContact(txn, s.getRemote().author,
-					localAuthor.getId(), false);
+			ContactId contactId = contactManager.addContact(txn,
+					s.getRemote().author, localAuthor.getId(), false);
 
 			// Only add transport properties and keys when the contact was added
 			// This will be changed once we have a way to reset state for peers
 			// that were contacts already at some point in the past.
-			Contact c = contactManager.getContact(txn,
-					s.getRemote().author.getId(), localAuthor.getId());
 
 			// add the keys to the new contact
-			keys = keyManager.addRotationKeys(txn, c.getId(),
+			keys = keyManager.addRotationKeys(txn, contactId,
 					new SecretKey(s.getMasterKey()), timestamp,
 					s.getLocal().alice, false);
 
 			// add signed transport properties for the contact
-			transportPropertyManager.addRemoteProperties(txn, c.getId(),
-					s.getRemote().transportProperties);
+			transportPropertyManager.addRemoteProperties(txn, contactId,
+					requireNonNull(s.getRemote().transportProperties));
 		} catch (ContactExistsException e) {
-			// Ignore this, because the other introducee might have deleted us.
-			// So we still want updated transport properties
-			// and new transport keys.
+			// Ignore this, because the other introducee might have deleted us
 		}
 
 		// send ACTIVATE message with a MAC
@@ -487,13 +495,13 @@ class IntroduceeProtocolEngine
 			IntroduceeSession s, ActivateMessage m) throws DbException {
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 
 		// Validate MAC
 		try {
 			crypto.verifyActivateMac(m.getMac(), s);
 		} catch (GeneralSecurityException e) {
-			return abort(txn, s);
+			return abort(txn, s, m.getMessageId());
 		}
 
 		// We might not have added transport keys
@@ -522,8 +530,8 @@ class IntroduceeProtocolEngine
 				s.getLocalTimestamp(), m.getMessageId());
 	}
 
-	private IntroduceeSession abort(Transaction txn, IntroduceeSession s)
-			throws DbException {
+	private IntroduceeSession abort(Transaction txn, IntroduceeSession s,
+			@Nullable MessageId lastRemoteMessageId) throws DbException {
 		// Mark the request message unavailable to answer
 		markRequestsUnavailableToAnswer(txn, s);
 
@@ -536,7 +544,7 @@ class IntroduceeProtocolEngine
 
 		// Reset the session back to initial state
 		return IntroduceeSession.clear(s, START, sent.getId(),
-				sent.getTimestamp(), s.getLastRemoteMessageId());
+				sent.getTimestamp(), lastRemoteMessageId);
 	}
 
 	private boolean isInvalidDependency(IntroduceeSession s,

briar-core/src/main/java/org/briarproject/briar/introduction/IntroduceeSession.java

@@ -116,8 +116,8 @@ class IntroduceeSession extends Session<IntroduceeState>
 
 	static IntroduceeSession awaitActivate(IntroduceeSession s, AuthMessage m,
 			Message sent, @Nullable Map<TransportId, KeySetId> transportKeys) {
-		Local local = new Local(s.local, sent.getId(), sent.getTimestamp());
-		Remote remote = new Remote(s.remote, m.getMessageId());
+		Local local = Local.clear(s.local, sent.getId(), sent.getTimestamp());
+		Remote remote = Remote.clear(s.remote, m.getMessageId());
 		return new IntroduceeSession(s.getSessionId(), AWAIT_ACTIVATE,
 				s.getRequestTimestamp(), s.contactGroupId, s.introducer, local,
 				remote, null, transportKeys);
@@ -228,11 +228,15 @@ class IntroduceeSession extends Session<IntroduceeState>
 			this.ephemeralPrivateKey = ephemeralPrivateKey;
 		}
 
-		private Local(Local s, @Nullable MessageId lastMessageId,
-				long lastMessageTimestamp) {
-			this(s.alice, lastMessageId, lastMessageTimestamp,
-					s.ephemeralPublicKey, s.ephemeralPrivateKey,
-					s.transportProperties, s.acceptTimestamp, s.macKey);
+		/**
+		 * Returns a copy of the given Local, updating the last message ID
+		 * and timestamp and clearing the ephemeral keys.
+		 */
+		private static Local clear(Local s,
+				@Nullable MessageId lastMessageId, long lastMessageTimestamp) {
+			return new Local(s.alice, lastMessageId, lastMessageTimestamp,
+					null, null, s.transportProperties, s.acceptTimestamp,
+					s.macKey);
 		}
 	}
 
@@ -249,10 +253,23 @@ class IntroduceeSession extends Session<IntroduceeState>
 			this.author = author;
 		}
 
+		/**
+		 * Returns a copy of the given Remote, updating the last message ID.
+		 */
 		private Remote(Remote s, @Nullable MessageId lastMessageId) {
 			this(s.alice, s.author, lastMessageId, s.ephemeralPublicKey,
 					s.transportProperties, s.acceptTimestamp, s.macKey);
 		}
+
+		/**
+		 * Returns a copy of the given Remote, updating the last message ID
+		 * and clearing the ephemeral keys.
+		 */
+		private static Remote clear(Remote s,
+				@Nullable MessageId lastMessageId) {
+			return new Remote(s.alice, s.author, lastMessageId, null,
+					s.transportProperties, s.acceptTimestamp, s.macKey);
+		}
 	}
 
 }

briar-core/src/main/java/org/briarproject/briar/introduction/IntroducerProtocolEngine.java

@@ -115,7 +115,7 @@ class IntroducerProtocolEngine
 	@Override
 	public IntroducerSession onRequestMessage(Transaction txn,
 			IntroducerSession s, RequestMessage m) throws DbException {
-		return abort(txn, s); // Invalid in this role
+		return abort(txn, s, m); // Invalid in this role
 	}
 
 	@Override
@@ -136,7 +136,7 @@ class IntroducerProtocolEngine
 			case AWAIT_ACTIVATES:
 			case AWAIT_ACTIVATE_A:
 			case AWAIT_ACTIVATE_B:
-				return abort(txn, s); // Invalid in these states
+				return abort(txn, s, m); // Invalid in these states
 			default:
 				throw new AssertionError();
 		}
@@ -160,7 +160,7 @@ class IntroducerProtocolEngine
 			case AWAIT_ACTIVATES:
 			case AWAIT_ACTIVATE_A:
 			case AWAIT_ACTIVATE_B:
-				return abort(txn, s); // Invalid in these states
+				return abort(txn, s, m); // Invalid in these states
 			default:
 				throw new AssertionError();
 		}
@@ -183,7 +183,7 @@ class IntroducerProtocolEngine
 			case AWAIT_ACTIVATES:
 			case AWAIT_ACTIVATE_A:
 			case AWAIT_ACTIVATE_B:
-				return abort(txn, s); // Invalid in these states
+				return abort(txn, s, m); // Invalid in these states
 			default:
 				throw new AssertionError();
 		}
@@ -206,7 +206,7 @@ class IntroducerProtocolEngine
 			case AWAIT_AUTHS:
 			case AWAIT_AUTH_A:
 			case AWAIT_AUTH_B:
-				return abort(txn, s); // Invalid in these states
+				return abort(txn, s, m); // Invalid in these states
 			default:
 				throw new AssertionError();
 		}
@@ -244,17 +244,17 @@ class IntroducerProtocolEngine
 			IntroducerSession s, AcceptMessage m) throws DbException {
 		// The timestamp must be higher than the last request message
 		if (m.getTimestamp() <= s.getRequestTimestamp())
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getGroupId(), m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The message must be expected in the current state
 		boolean senderIsAlice = senderIsAlice(s, m);
 		if (s.getState() != AWAIT_RESPONSES) {
 			if (senderIsAlice && s.getState() != AWAIT_RESPONSE_A)
-				return abort(txn, s);
+				return abort(txn, s, m);
 			else if (!senderIsAlice && s.getState() != AWAIT_RESPONSE_B)
-				return abort(txn, s);
+				return abort(txn, s, m);
 		}
 
 		// Mark the response visible in the UI
@@ -309,16 +309,16 @@ class IntroducerProtocolEngine
 			IntroducerSession s, AcceptMessage m) throws DbException {
 		// The timestamp must be higher than the last request message
 		if (m.getTimestamp() <= s.getRequestTimestamp())
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getGroupId(), m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The message must be expected in the current state
 		boolean senderIsAlice = senderIsAlice(s, m);
 		if (senderIsAlice && s.getState() != B_DECLINED)
-			return abort(txn, s);
+			return abort(txn, s, m);
 		else if (!senderIsAlice && s.getState() != A_DECLINED)
-			return abort(txn, s);
+			return abort(txn, s, m);
 
 		// Mark the response visible in the UI
 		markMessageVisibleInUi(txn, m.getMessageId());
@@ -362,17 +362,17 @@ class IntroducerProtocolEngine
 			IntroducerSession s, DeclineMessage m) throws DbException {
 		// The timestamp must be higher than the last request message
 		if (m.getTimestamp() <= s.getRequestTimestamp())
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getGroupId(), m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The message must be expected in the current state
 		boolean senderIsAlice = senderIsAlice(s, m);
 		if (s.getState() != AWAIT_RESPONSES) {
 			if (senderIsAlice && s.getState() != AWAIT_RESPONSE_A)
-				return abort(txn, s);
+				return abort(txn, s, m);
 			else if (!senderIsAlice && s.getState() != AWAIT_RESPONSE_B)
-				return abort(txn, s);
+				return abort(txn, s, m);
 		}
 
 		// Mark the response visible in the UI
@@ -419,16 +419,16 @@ class IntroducerProtocolEngine
 			IntroducerSession s, DeclineMessage m) throws DbException {
 		// The timestamp must be higher than the last request message
 		if (m.getTimestamp() <= s.getRequestTimestamp())
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getGroupId(), m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The message must be expected in the current state
 		boolean senderIsAlice = senderIsAlice(s, m);
 		if (senderIsAlice && s.getState() != B_DECLINED)
-			return abort(txn, s);
+			return abort(txn, s, m);
 		else if (!senderIsAlice && s.getState() != A_DECLINED)
-			return abort(txn, s);
+			return abort(txn, s, m);
 
 		// Mark the response visible in the UI
 		markMessageVisibleInUi(txn, m.getMessageId());
@@ -470,14 +470,14 @@ class IntroducerProtocolEngine
 			IntroducerSession s, AuthMessage m) throws DbException {
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getGroupId(), m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The message must be expected in the current state
 		boolean senderIsAlice = senderIsAlice(s, m);
 		if (s.getState() != AWAIT_AUTHS) {
 			if (senderIsAlice && s.getState() != AWAIT_AUTH_A)
-				return abort(txn, s);
+				return abort(txn, s, m);
 			else if (!senderIsAlice && s.getState() != AWAIT_AUTH_B)
-				return abort(txn, s);
+				return abort(txn, s, m);
 		}
 
 		// Forward AUTH message
@@ -506,14 +506,14 @@ class IntroducerProtocolEngine
 			IntroducerSession s, ActivateMessage m) throws DbException {
 		// The dependency, if any, must be the last remote message
 		if (isInvalidDependency(s, m.getGroupId(), m.getPreviousMessageId()))
-			return abort(txn, s);
+			return abort(txn, s, m);
 		// The message must be expected in the current state
 		boolean senderIsAlice = senderIsAlice(s, m);
 		if (s.getState() != AWAIT_ACTIVATES) {
 			if (senderIsAlice && s.getState() != AWAIT_ACTIVATE_A)
-				return abort(txn, s);
+				return abort(txn, s, m);
 			else if (!senderIsAlice && s.getState() != AWAIT_ACTIVATE_B)
-				return abort(txn, s);
+				return abort(txn, s, m);
 		}
 
 		// Forward ACTIVATE message
@@ -588,21 +588,31 @@ class IntroducerProtocolEngine
 				s.getRequestTimestamp(), introduceeA, introduceeB);
 	}
 
-	private IntroducerSession abort(Transaction txn, IntroducerSession s)
-			throws DbException {
+	private IntroducerSession abort(Transaction txn, IntroducerSession s,
+			AbstractIntroductionMessage lastRemoteMessage) throws DbException {
 		// Broadcast abort event for testing
 		txn.attach(new IntroductionAbortedEvent(s.getSessionId()));
 
+		// Record the message that triggered the abort
+		Introducee introduceeA = s.getIntroduceeA();
+		Introducee introduceeB = s.getIntroduceeB();
+		if (senderIsAlice(s, lastRemoteMessage)) {
+			introduceeA = new Introducee(introduceeA,
+					lastRemoteMessage.getMessageId());
+		} else {
+			introduceeB = new Introducee(introduceeB,
+					lastRemoteMessage.getMessageId());
+		}
+
 		// Send an ABORT message to both introducees
-		long timestampA =
-				getTimestampForInvisibleMessage(s, s.getIntroduceeA());
-		Message sentA = sendAbortMessage(txn, s.getIntroduceeA(), timestampA);
-		long timestampB =
-				getTimestampForInvisibleMessage(s, s.getIntroduceeB());
-		Message sentB = sendAbortMessage(txn, s.getIntroduceeB(), timestampB);
+		long timestampA = getTimestampForInvisibleMessage(s, introduceeA);
+		Message sentA = sendAbortMessage(txn, introduceeA, timestampA);
+		long timestampB = getTimestampForInvisibleMessage(s, introduceeB);
+		Message sentB = sendAbortMessage(txn, introduceeB, timestampB);
+
 		// Reset the session back to initial state
-		Introducee introduceeA = new Introducee(s.getIntroduceeA(), sentA);
-		Introducee introduceeB = new Introducee(s.getIntroduceeB(), sentB);
+		introduceeA = new Introducee(introduceeA, sentA);
+		introduceeB = new Introducee(introduceeB, sentB);
 		return new IntroducerSession(s.getSessionId(), START,
 				s.getRequestTimestamp(), introduceeA, introduceeB);
 	}

briar-core/src/main/java/org/briarproject/briar/introduction/IntroductionManagerImpl.java

@@ -56,6 +56,7 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
 import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 import static org.briarproject.briar.api.introduction.Role.INTRODUCEE;
 import static org.briarproject.briar.api.introduction.Role.INTRODUCER;
@@ -171,8 +172,9 @@ class IntroductionManagerImpl extends ConversationClientImpl
 	}
 
 	@Override
-	protected boolean incomingMessage(Transaction txn, Message m, BdfList body,
-			BdfDictionary bdfMeta) throws DbException, FormatException {
+	protected DeliveryAction incomingMessage(Transaction txn, Message m,
+			BdfList body, BdfDictionary bdfMeta)
+			throws DbException, FormatException {
 		// Parse the metadata
 		MessageMetadata meta = messageParser.parseMetadata(bdfMeta);
 		// set the clean-up timer that will be started when message gets read
@@ -213,7 +215,7 @@ class IntroductionManagerImpl extends ConversationClientImpl
 		}
 		// Store the updated session
 		storeSession(txn, storageId, session);
-		return false;
+		return ACCEPT_DO_NOT_SHARE;
 	}
 
 	private IntroduceeSession createNewIntroduceeSession(Transaction txn,

briar-core/src/main/java/org/briarproject/briar/messaging/MessagingManagerImpl.java

@@ -63,6 +63,7 @@ import static java.util.Collections.emptyList;
 import static java.util.logging.Logger.getLogger;
 import static org.briarproject.bramble.api.client.ContactGroupConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
 import static org.briarproject.bramble.util.IoUtils.copyAndClose;
 import static org.briarproject.bramble.util.LogUtils.logDuration;
 import static org.briarproject.bramble.util.LogUtils.now;
@@ -172,8 +173,8 @@ class MessagingManagerImpl implements MessagingManager, IncomingMessageHook,
 	}
 
 	@Override
-	public boolean incomingMessage(Transaction txn, Message m, Metadata meta)
-			throws DbException, InvalidMessageException {
+	public DeliveryAction incomingMessage(Transaction txn, Message m,
+			Metadata meta) throws DbException, InvalidMessageException {
 		try {
 			BdfDictionary metaDict = metadataParser.parse(meta);
 			// Message type is null for version 0.0 private messages
@@ -193,8 +194,7 @@ class MessagingManagerImpl implements MessagingManager, IncomingMessageHook,
 		} catch (FormatException e) {
 			throw new InvalidMessageException(e);
 		}
-		// Don't share message
-		return false;
+		return ACCEPT_DO_NOT_SHARE;
 	}
 
 	private void incomingPrivateMessage(Transaction txn, Message m,

briar-core/src/main/java/org/briarproject/briar/privategroup/PrivateGroupManagerImpl.java

@@ -55,6 +55,7 @@ import java.util.concurrent.CopyOnWriteArrayList;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_SHARE;
 import static org.briarproject.briar.api.identity.AuthorInfo.Status.UNVERIFIED;
 import static org.briarproject.briar.api.identity.AuthorInfo.Status.VERIFIED;
 import static org.briarproject.briar.api.privategroup.MessageType.JOIN;
@@ -518,18 +519,19 @@ class PrivateGroupManagerImpl extends BdfIncomingMessageHook
 	}
 
 	@Override
-	protected boolean incomingMessage(Transaction txn, Message m, BdfList body,
-			BdfDictionary meta) throws DbException, FormatException {
+	protected DeliveryAction incomingMessage(Transaction txn, Message m,
+			BdfList body, BdfDictionary meta)
+			throws DbException, FormatException {
 
 		MessageType type =
 				MessageType.valueOf(meta.getLong(KEY_TYPE).intValue());
 		switch (type) {
 			case JOIN:
 				handleJoinMessage(txn, m, meta);
-				return true;
+				return ACCEPT_SHARE;
 			case POST:
 				handleGroupMessage(txn, m, meta);
-				return true;
+				return ACCEPT_SHARE;
 			default:
 				// the validator should only let valid types pass
 				throw new RuntimeException("Unknown MessageType");

briar-core/src/main/java/org/briarproject/briar/privategroup/invitation/GroupInvitationManagerImpl.java

@@ -54,6 +54,7 @@ import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
 import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 import static org.briarproject.briar.privategroup.invitation.CreatorState.START;
 import static org.briarproject.briar.privategroup.invitation.MessageType.ABORT;
@@ -147,8 +148,9 @@ class GroupInvitationManagerImpl extends ConversationClientImpl
 	}
 
 	@Override
-	protected boolean incomingMessage(Transaction txn, Message m, BdfList body,
-			BdfDictionary bdfMeta) throws DbException, FormatException {
+	protected DeliveryAction incomingMessage(Transaction txn, Message m,
+			BdfList body, BdfDictionary bdfMeta)
+			throws DbException, FormatException {
 		// Parse the metadata
 		MessageMetadata meta = messageParser.parseMetadata(bdfMeta);
 		// set the clean-up timer that will be started when message gets read
@@ -171,7 +173,7 @@ class GroupInvitationManagerImpl extends ConversationClientImpl
 		}
 		// Store the updated session
 		storeSession(txn, storageId, session);
-		return false;
+		return ACCEPT_DO_NOT_SHARE;
 	}
 
 	private SessionId getSessionId(GroupId privateGroupId) {

briar-core/src/main/java/org/briarproject/briar/sharing/SharingManagerImpl.java

@@ -49,6 +49,7 @@ import java.util.Set;
 import javax.annotation.Nullable;
 
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
 import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 import static org.briarproject.briar.sharing.MessageType.ABORT;
 import static org.briarproject.briar.sharing.MessageType.ACCEPT;
@@ -133,8 +134,8 @@ abstract class SharingManagerImpl<S extends Shareable>
 	}
 
 	@Override
-	protected boolean incomingMessage(Transaction txn, Message m, BdfList body,
-			BdfDictionary d) throws DbException, FormatException {
+	protected DeliveryAction incomingMessage(Transaction txn, Message m,
+			BdfList body, BdfDictionary d) throws DbException, FormatException {
 		// Parse the metadata
 		MessageMetadata meta = messageParser.parseMetadata(d);
 		// set the clean-up timer that will be started when message gets read
@@ -157,7 +158,7 @@ abstract class SharingManagerImpl<S extends Shareable>
 		}
 		// Store the updated session
 		storeSession(txn, storageId, session);
-		return false;
+		return ACCEPT_DO_NOT_SHARE;
 	}
 
 	/**

briar-core/src/test/java/org/briarproject/briar/avatar/AvatarManagerImplTest.java

@@ -44,6 +44,7 @@ import javax.annotation.Nullable;
 import static org.briarproject.bramble.api.sync.Group.Visibility.INVISIBLE;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
 import static org.briarproject.bramble.api.sync.Group.Visibility.VISIBLE;
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
 import static org.briarproject.bramble.test.TestUtils.getContact;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getLocalAuthor;
@@ -59,7 +60,6 @@ import static org.briarproject.briar.api.avatar.AvatarManager.MAJOR_VERSION;
 import static org.briarproject.briar.avatar.AvatarConstants.GROUP_KEY_CONTACT_ID;
 import static org.briarproject.briar.avatar.AvatarConstants.MSG_KEY_VERSION;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
 
 public class AvatarManagerImplTest extends BrambleMockTestCase {
 
@@ -196,7 +196,8 @@ public class AvatarManagerImplTest extends BrambleMockTestCase {
 				null);
 		expectGetContactId(txn, contactGroupId, contact.getId());
 
-		assertFalse(avatarManager.incomingMessage(txn, contactMsg, meta));
+		assertEquals(ACCEPT_DO_NOT_SHARE,
+				avatarManager.incomingMessage(txn, contactMsg, meta));
 		assertEquals(1, txn.getActions().size());
 		Event event = ((EventAction) txn.getActions().get(0)).getEvent();
 		AvatarUpdatedEvent avatarUpdatedEvent = (AvatarUpdatedEvent) event;
@@ -230,7 +231,8 @@ public class AvatarManagerImplTest extends BrambleMockTestCase {
 		expectFindLatest(txn, contactGroupId, latestMsgId, latest);
 		expectGetContactId(txn, contactGroupId, contact.getId());
 
-		assertFalse(avatarManager.incomingMessage(txn, contactMsg, meta));
+		assertEquals(ACCEPT_DO_NOT_SHARE,
+				avatarManager.incomingMessage(txn, contactMsg, meta));
 
 		// event to broadcast
 		assertEquals(1, txn.getActions().size());
@@ -260,7 +262,8 @@ public class AvatarManagerImplTest extends BrambleMockTestCase {
 		}});
 		expectFindLatest(txn, contactGroupId, latestMsgId, latest);
 
-		assertFalse(avatarManager.incomingMessage(txn, contactMsg, meta));
+		assertEquals(ACCEPT_DO_NOT_SHARE,
+				avatarManager.incomingMessage(txn, contactMsg, meta));
 
 		// no event to broadcast
 		assertEquals(0, txn.getActions().size());
@@ -271,7 +274,8 @@ public class AvatarManagerImplTest extends BrambleMockTestCase {
 			throws DbException, InvalidMessageException {
 		Transaction txn = new Transaction(null, false);
 		expectGetOurGroup(txn);
-		avatarManager.incomingMessage(txn, ourMsg, meta);
+		assertEquals(ACCEPT_DO_NOT_SHARE,
+				avatarManager.incomingMessage(txn, ourMsg, meta));
 	}
 
 	@Test

briar-core/src/test/java/org/briarproject/briar/blog/BlogManagerImplTest.java

@@ -33,6 +33,7 @@ import org.jmock.Expectations;
 import org.jmock.Mockery;
 import org.junit.Test;
 
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_SHARE;
 import static org.briarproject.bramble.test.TestUtils.getContact;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
 import static org.briarproject.bramble.test.TestUtils.getLocalAuthor;
@@ -184,7 +185,8 @@ public class BlogManagerImplTest extends BriarTestCase {
 			will(returnValue(verifiedInfo));
 		}});
 
-		blogManager.incomingMessage(txn, message, body, meta);
+		assertEquals(ACCEPT_SHARE,
+				blogManager.incomingMessage(txn, message, body, meta));
 		context.assertIsSatisfied();
 
 		assertEquals(1, txn.getActions().size());
@@ -225,7 +227,8 @@ public class BlogManagerImplTest extends BriarTestCase {
 			will(returnValue(rssLocalAuthor));
 		}});
 
-		blogManager.incomingMessage(txn, rssMessage, body, meta);
+		assertEquals(ACCEPT_SHARE,
+				blogManager.incomingMessage(txn, rssMessage, body, meta));
 		context.assertIsSatisfied();
 
 		assertEquals(1, txn.getActions().size());

briar-core/src/test/java/org/briarproject/briar/introduction/IntroduceeProtocolEngineTest.java

@@ -0,0 +1,263 @@
+package org.briarproject.briar.introduction;
+
+import org.briarproject.bramble.api.client.ClientHelper;
+import org.briarproject.bramble.api.client.ContactGroupFactory;
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.contact.ContactManager;
+import org.briarproject.bramble.api.crypto.PrivateKey;
+import org.briarproject.bramble.api.crypto.PublicKey;
+import org.briarproject.bramble.api.crypto.SecretKey;
+import org.briarproject.bramble.api.data.BdfDictionary;
+import org.briarproject.bramble.api.db.DatabaseComponent;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.identity.Author;
+import org.briarproject.bramble.api.identity.IdentityManager;
+import org.briarproject.bramble.api.identity.LocalAuthor;
+import org.briarproject.bramble.api.plugin.TransportId;
+import org.briarproject.bramble.api.properties.TransportPropertyManager;
+import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.sync.Message;
+import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.bramble.api.system.Clock;
+import org.briarproject.bramble.api.transport.KeyManager;
+import org.briarproject.bramble.api.transport.KeySetId;
+import org.briarproject.bramble.api.versioning.ClientVersioningManager;
+import org.briarproject.bramble.test.BrambleMockTestCase;
+import org.briarproject.briar.api.autodelete.AutoDeleteManager;
+import org.briarproject.briar.api.client.MessageTracker;
+import org.briarproject.briar.api.client.SessionId;
+import org.briarproject.briar.api.conversation.ConversationManager;
+import org.briarproject.briar.api.identity.AuthorManager;
+import org.jmock.Expectations;
+import org.junit.Test;
+
+import java.util.Collections;
+import java.util.Random;
+
+import static java.util.Collections.emptyList;
+import static java.util.Collections.emptyMap;
+import static org.briarproject.bramble.api.crypto.CryptoConstants.MAC_BYTES;
+import static org.briarproject.bramble.api.crypto.CryptoConstants.MAX_SIGNATURE_BYTES;
+import static org.briarproject.bramble.api.system.Clock.MIN_REASONABLE_TIME_MS;
+import static org.briarproject.bramble.test.TestUtils.getAgreementPrivateKey;
+import static org.briarproject.bramble.test.TestUtils.getAgreementPublicKey;
+import static org.briarproject.bramble.test.TestUtils.getAuthor;
+import static org.briarproject.bramble.test.TestUtils.getContactId;
+import static org.briarproject.bramble.test.TestUtils.getLocalAuthor;
+import static org.briarproject.bramble.test.TestUtils.getMessage;
+import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
+import static org.briarproject.bramble.test.TestUtils.getRandomId;
+import static org.briarproject.bramble.test.TestUtils.getSecretKey;
+import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
+import static org.briarproject.briar.introduction.IntroduceeState.AWAIT_ACTIVATE;
+import static org.briarproject.briar.introduction.IntroduceeState.AWAIT_AUTH;
+import static org.briarproject.briar.introduction.IntroduceeState.START;
+import static org.briarproject.briar.introduction.MessageType.ABORT;
+import static org.briarproject.briar.introduction.MessageType.ACTIVATE;
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+public class IntroduceeProtocolEngineTest extends BrambleMockTestCase {
+
+	private final DatabaseComponent db = context.mock(DatabaseComponent.class);
+	private final ClientHelper clientHelper = context.mock(ClientHelper.class);
+	private final ContactManager contactManager =
+			context.mock(ContactManager.class);
+	private final ContactGroupFactory contactGroupFactory =
+			context.mock(ContactGroupFactory.class);
+	private final MessageTracker messageTracker =
+			context.mock(MessageTracker.class);
+	private final IdentityManager identityManager =
+			context.mock(IdentityManager.class);
+	private final AuthorManager authorManager =
+			context.mock(AuthorManager.class);
+	private final MessageParser messageParser =
+			context.mock(MessageParser.class);
+	private final MessageEncoder messageEncoder =
+			context.mock(MessageEncoder.class);
+	private final IntroductionCrypto crypto =
+			context.mock(IntroductionCrypto.class);
+	private final KeyManager keyManager = context.mock(KeyManager.class);
+	private final TransportPropertyManager transportPropertyManager =
+			context.mock(TransportPropertyManager.class);
+	private final ClientVersioningManager clientVersioningManager =
+			context.mock(ClientVersioningManager.class);
+	private final AutoDeleteManager autoDeleteManager =
+			context.mock(AutoDeleteManager.class);
+	private final ConversationManager conversationManager =
+			context.mock(ConversationManager.class);
+	private final Clock clock = context.mock(Clock.class);
+
+	private final Author introducer = getAuthor();
+	private final Author remoteIntroducee = getAuthor();
+	private final LocalAuthor localIntroducee = getLocalAuthor();
+	private final ContactId contactId = getContactId();
+	private final GroupId contactGroupId = new GroupId(getRandomId());
+	private final SessionId sessionId = new SessionId(getRandomId());
+	private final boolean alice = new Random().nextBoolean();
+	private final long now = System.currentTimeMillis();
+	private final long requestTimestamp = now - 12345;
+	private final long localAcceptTimestamp = requestTimestamp + 123;
+	private final long remoteAuthTimestamp = localAcceptTimestamp + 123;
+	private final MessageId lastLocalMessageId = new MessageId(getRandomId());
+	private final MessageId lastRemoteMessageId = new MessageId(getRandomId());
+	private final PublicKey localPublicKey = getAgreementPublicKey();
+	private final PrivateKey localPrivateKey = getAgreementPrivateKey();
+	private final PublicKey remotePublicKey = getAgreementPublicKey();
+	private final SecretKey localMacKey = getSecretKey();
+	private final SecretKey remoteMacKey = getSecretKey();
+	private final SecretKey masterKey = getSecretKey();
+	private final byte[] remoteMac = getRandomBytes(MAC_BYTES);
+	private final byte[] localMac = getRandomBytes(MAC_BYTES);
+	private final byte[] remoteSignature = getRandomBytes(MAX_SIGNATURE_BYTES);
+
+	private final IntroduceeProtocolEngine engine =
+			new IntroduceeProtocolEngine(db, clientHelper, contactManager,
+					contactGroupFactory, messageTracker, identityManager,
+					authorManager, messageParser, messageEncoder, crypto,
+					keyManager, transportPropertyManager,
+					clientVersioningManager, autoDeleteManager,
+					conversationManager, clock);
+
+	@Test
+	public void testDoesNotAbortSessionIfTimestampIsMaxAge() throws Exception {
+		Transaction txn = new Transaction(null, false);
+
+		long remoteAcceptTimestamp = MIN_REASONABLE_TIME_MS;
+		IntroduceeSession session =
+				createAwaitAuthSession(remoteAcceptTimestamp);
+
+		AuthMessage authMessage = new AuthMessage(new MessageId(getRandomId()),
+				contactGroupId, remoteAuthTimestamp, lastRemoteMessageId,
+				sessionId, remoteMac, remoteSignature);
+
+		Message activateMessage = getMessage(contactGroupId, 1234, now);
+		BdfDictionary activateMeta = new BdfDictionary();
+
+		context.checking(new Expectations() {{
+			// Verify the auth message
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localIntroducee));
+			oneOf(crypto).verifyAuthMac(remoteMac, session,
+					localIntroducee.getId());
+			oneOf(crypto).verifySignature(remoteSignature, session);
+			// Add the contact
+			oneOf(contactManager).addContact(txn, remoteIntroducee,
+					localIntroducee.getId(), false);
+			will(returnValue(contactId));
+			oneOf(keyManager).addRotationKeys(txn, contactId, masterKey,
+					remoteAcceptTimestamp, alice, false);
+			will(returnValue(emptyMap()));
+			oneOf(transportPropertyManager).addRemoteProperties(txn, contactId,
+					emptyMap());
+			// Send the activate message
+			oneOf(crypto).activateMac(session);
+			will(returnValue(localMac));
+			oneOf(clock).currentTimeMillis();
+			will(returnValue(now));
+			oneOf(messageEncoder).encodeActivateMessage(contactGroupId, now,
+					lastLocalMessageId, sessionId, localMac);
+			will(returnValue(activateMessage));
+			oneOf(messageEncoder).encodeMetadata(ACTIVATE, sessionId, now,
+					true, true, false, NO_AUTO_DELETE_TIMER, false);
+			will(returnValue(activateMeta));
+			oneOf(clientHelper).addLocalMessage(txn, activateMessage,
+					activateMeta, true, false);
+		}});
+
+		IntroduceeSession after =
+				engine.onAuthMessage(txn, session, authMessage);
+
+		assertEquals(AWAIT_ACTIVATE, after.getState());
+		assertNull(after.getMasterKey());
+		assertEquals(Collections.<TransportId, KeySetId>emptyMap(),
+				after.getTransportKeys());
+
+		IntroduceeSession.Local afterLocal = after.getLocal();
+		assertEquals(activateMessage.getId(), afterLocal.lastMessageId);
+		assertEquals(now, afterLocal.lastMessageTimestamp);
+		assertNull(afterLocal.ephemeralPublicKey);
+		assertNull(afterLocal.ephemeralPrivateKey);
+		assertArrayEquals(localMacKey.getBytes(), afterLocal.macKey);
+
+		IntroduceeSession.Remote afterRemote = after.getRemote();
+		assertEquals(authMessage.getMessageId(), afterRemote.lastMessageId);
+		assertNull(afterRemote.ephemeralPublicKey);
+		assertArrayEquals(remoteMacKey.getBytes(), afterRemote.macKey);
+	}
+
+	@Test
+	public void testAbortsSessionIfTimestampIsTooOld() throws Exception {
+		Transaction txn = new Transaction(null, false);
+
+		long remoteAcceptTimestamp = MIN_REASONABLE_TIME_MS - 1;
+		IntroduceeSession session =
+				createAwaitAuthSession(remoteAcceptTimestamp);
+
+		AuthMessage authMessage = new AuthMessage(new MessageId(getRandomId()),
+				contactGroupId, remoteAuthTimestamp, lastRemoteMessageId,
+				sessionId, remoteMac, remoteSignature);
+
+		BdfDictionary query = new BdfDictionary();
+		Message abortMessage = getMessage(contactGroupId, 123, now);
+		BdfDictionary abortMeta = new BdfDictionary();
+
+		context.checking(new Expectations() {{
+			// Verify the auth message
+			oneOf(identityManager).getLocalAuthor(txn);
+			will(returnValue(localIntroducee));
+			oneOf(crypto).verifyAuthMac(remoteMac, session,
+					localIntroducee.getId());
+			oneOf(crypto).verifySignature(remoteSignature, session);
+			// Abort the session
+			oneOf(messageParser).getRequestsAvailableToAnswerQuery(sessionId);
+			will(returnValue(query));
+			oneOf(clientHelper).getMessageIds(txn, contactGroupId, query);
+			will(returnValue(emptyList()));
+			oneOf(clock).currentTimeMillis();
+			will(returnValue(now));
+			oneOf(messageEncoder).encodeAbortMessage(contactGroupId, now,
+					lastLocalMessageId, sessionId);
+			will(returnValue(abortMessage));
+			oneOf(messageEncoder).encodeMetadata(ABORT, sessionId, now,
+					true, true, false, NO_AUTO_DELETE_TIMER, false);
+			will(returnValue(abortMeta));
+			oneOf(clientHelper).addLocalMessage(txn, abortMessage, abortMeta,
+					true, false);
+		}});
+
+		IntroduceeSession after =
+				engine.onAuthMessage(txn, session, authMessage);
+
+		assertEquals(START, after.getState());
+		assertNull(after.getMasterKey());
+		assertNull(after.getTransportKeys());
+
+		IntroduceeSession.Local afterLocal = after.getLocal();
+		assertEquals(abortMessage.getId(), afterLocal.lastMessageId);
+		assertEquals(now, afterLocal.lastMessageTimestamp);
+		assertNull(afterLocal.ephemeralPublicKey);
+		assertNull(afterLocal.ephemeralPrivateKey);
+		assertNull(afterLocal.macKey);
+
+		IntroduceeSession.Remote afterRemote = after.getRemote();
+		assertEquals(authMessage.getMessageId(), afterRemote.lastMessageId);
+		assertNull(afterRemote.ephemeralPublicKey);
+		assertNull(afterRemote.macKey);
+	}
+
+	private IntroduceeSession createAwaitAuthSession(
+			long remoteAcceptTimestamp) {
+		IntroduceeSession.Local local = new IntroduceeSession.Local(alice,
+				lastLocalMessageId, localAcceptTimestamp, localPublicKey,
+				localPrivateKey, emptyMap(), localAcceptTimestamp,
+				localMacKey.getBytes());
+		IntroduceeSession.Remote remote = new IntroduceeSession.Remote(!alice,
+				remoteIntroducee, lastRemoteMessageId, remotePublicKey,
+				emptyMap(), remoteAcceptTimestamp, remoteMacKey.getBytes());
+		return new IntroduceeSession(sessionId,
+				AWAIT_AUTH, requestTimestamp, contactGroupId, introducer,
+				local, remote, masterKey.getBytes(), emptyMap());
+	}
+}

briar-core/src/test/java/org/briarproject/briar/messaging/SimplexMessagingIntegrationTest.java

@@ -11,7 +11,9 @@ import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.sync.event.MessageStateChangedEvent;
+import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
 import org.briarproject.bramble.test.TestDatabaseConfigModule;
 import org.briarproject.bramble.test.TestTransportConnectionReader;
 import org.briarproject.bramble.test.TestTransportConnectionWriter;
@@ -71,7 +73,16 @@ public class SimplexMessagingIntegrationTest extends BriarTestCase {
 	}
 
 	@Test
-	public void testWriteAndRead() throws Exception {
+	public void testWriteAndReadWithLazyRetransmission() throws Exception {
+		testWriteAndRead(false);
+	}
+
+	@Test
+	public void testWriteAndReadWithEagerRetransmission() throws Exception {
+		testWriteAndRead(true);
+	}
+
+	private void testWriteAndRead(boolean eager) throws Exception {
 		// Create the identities
 		Identity aliceIdentity =
 				alice.getIdentityManager().createIdentity("Alice");
@@ -86,16 +97,21 @@ public class SimplexMessagingIntegrationTest extends BriarTestCase {
 		bob.getEventBus().addListener(listener);
 		// Alice sends a private message to Bob
 		sendMessage(alice, bobId);
-		// Sync Alice's client versions and transport properties
-		read(bob, write(alice, bobId), 2);
-		// Sync Bob's client versions and transport properties
-		read(alice, write(bob, aliceId), 2);
-		// Sync the private message and the attachment
-		read(bob, write(alice, bobId), 2);
+		// Sync Alice's client versions
+		read(bob, write(alice, bobId, eager, 1), 1);
+		// Sync Bob's client versions
+		read(alice, write(bob, aliceId, eager, 1), 1);
+		// Sync Alice's second client versioning update (with the active flag
+		// raised), the private message and the attachment
+		read(bob, write(alice, bobId, eager, 3), 3);
 		// Bob should have received the private message
 		assertTrue(listener.messageAdded);
 		// Bob should have received the attachment
 		assertTrue(listener.attachmentAdded);
+		// Sync messages from Alice to Bob again. If using eager
+		// retransmission, the three unacked messages should be sent again.
+		// They're all duplicates, so no further deliveries should occur
+		read(bob, write(alice, bobId, eager, eager ? 3 : 0), 0);
 	}
 
 	private ContactId setUp(SimplexMessagingIntegrationTestComponent device,
@@ -149,15 +165,24 @@ public class SimplexMessagingIntegrationTest extends BriarTestCase {
 	}
 
 	private byte[] write(SimplexMessagingIntegrationTestComponent device,
-			ContactId contactId) throws Exception {
+			ContactId contactId, boolean eager, int transmissions)
+			throws Exception {
+		// Listen for message transmissions
+		MessageTransmissionListener listener =
+				new MessageTransmissionListener(transmissions);
+		device.getEventBus().addListener(listener);
 		// Write the outgoing stream
 		ByteArrayOutputStream out = new ByteArrayOutputStream();
 		TestTransportConnectionWriter writer =
-				new TestTransportConnectionWriter(out);
+				new TestTransportConnectionWriter(out, eager);
 		device.getConnectionManager().manageOutgoingConnection(contactId,
 				SIMPLEX_TRANSPORT_ID, writer);
 		// Wait for the writer to be disposed
 		writer.getDisposedLatch().await(TIMEOUT_MS, MILLISECONDS);
+		// Check that the expected number of messages were sent
+		assertTrue(listener.sent.await(TIMEOUT_MS, MILLISECONDS));
+		// Clean up the listener
+		device.getEventBus().removeListener(listener);
 		// Return the contents of the stream
 		return out.toByteArray();
 	}
@@ -178,6 +203,24 @@ public class SimplexMessagingIntegrationTest extends BriarTestCase {
 		deleteTestDirectory(testDir);
 	}
 
+	@NotNullByDefault
+	private static class MessageTransmissionListener implements EventListener {
+
+		private final CountDownLatch sent;
+
+		private MessageTransmissionListener(int transmissions) {
+			sent = new CountDownLatch(transmissions);
+		}
+
+		@Override
+		public void eventOccurred(Event e) {
+			if (e instanceof MessagesSentEvent) {
+				MessagesSentEvent m = (MessagesSentEvent) e;
+				for (MessageId ignored : m.getMessageIds()) sent.countDown();
+			}
+		}
+	}
+
 	@NotNullByDefault
 	private static class MessageDeliveryListener implements EventListener {
 
@@ -191,7 +234,9 @@ public class SimplexMessagingIntegrationTest extends BriarTestCase {
 		public void eventOccurred(Event e) {
 			if (e instanceof MessageStateChangedEvent) {
 				MessageStateChangedEvent m = (MessageStateChangedEvent) e;
-				if (m.getState().equals(DELIVERED)) delivered.countDown();
+				if (!m.isLocal() && m.getState().equals(DELIVERED)) {
+					delivered.countDown();
+				}
 			}
 		}
 	}

briar-core/src/test/java/org/briarproject/briar/privategroup/invitation/GroupInvitationManagerImplTest.java

@@ -47,6 +47,7 @@ import javax.annotation.Nullable;
 import static java.util.Arrays.asList;
 import static junit.framework.TestCase.fail;
 import static org.briarproject.bramble.api.sync.Group.Visibility.SHARED;
+import static org.briarproject.bramble.api.sync.validation.IncomingMessageHook.DeliveryAction.ACCEPT_DO_NOT_SHARE;
 import static org.briarproject.bramble.test.TestUtils.getAuthor;
 import static org.briarproject.bramble.test.TestUtils.getContact;
 import static org.briarproject.bramble.test.TestUtils.getGroup;
@@ -275,43 +276,50 @@ public class GroupInvitationManagerImplTest extends BrambleMockTestCase {
 	@Test
 	public void testIncomingFirstInviteMessage() throws Exception {
 		expectFirstIncomingMessage(Role.INVITEE, INVITE);
-		groupInvitationManager.incomingMessage(txn, message, body, meta);
+		assertEquals(ACCEPT_DO_NOT_SHARE, groupInvitationManager
+				.incomingMessage(txn, message, body, meta));
 	}
 
 	@Test
 	public void testIncomingFirstJoinMessage() throws Exception {
 		expectFirstIncomingMessage(Role.PEER, JOIN);
-		groupInvitationManager.incomingMessage(txn, message, body, meta);
+		assertEquals(ACCEPT_DO_NOT_SHARE, groupInvitationManager
+				.incomingMessage(txn, message, body, meta));
 	}
 
 	@Test
 	public void testIncomingInviteMessage() throws Exception {
 		expectIncomingMessage(Role.INVITEE, INVITE);
-		groupInvitationManager.incomingMessage(txn, message, body, meta);
+		assertEquals(ACCEPT_DO_NOT_SHARE, groupInvitationManager
+				.incomingMessage(txn, message, body, meta));
 	}
 
 	@Test
 	public void testIncomingJoinMessage() throws Exception {
 		expectIncomingMessage(Role.INVITEE, JOIN);
-		groupInvitationManager.incomingMessage(txn, message, body, meta);
+		assertEquals(ACCEPT_DO_NOT_SHARE, groupInvitationManager
+				.incomingMessage(txn, message, body, meta));
 	}
 
 	@Test
 	public void testIncomingJoinMessageForCreator() throws Exception {
 		expectIncomingMessage(Role.CREATOR, JOIN);
-		groupInvitationManager.incomingMessage(txn, message, body, meta);
+		assertEquals(ACCEPT_DO_NOT_SHARE, groupInvitationManager
+				.incomingMessage(txn, message, body, meta));
 	}
 
 	@Test
 	public void testIncomingLeaveMessage() throws Exception {
 		expectIncomingMessage(Role.INVITEE, LEAVE);
-		groupInvitationManager.incomingMessage(txn, message, body, meta);
+		assertEquals(ACCEPT_DO_NOT_SHARE, groupInvitationManager
+				.incomingMessage(txn, message, body, meta));
 	}
 
 	@Test
 	public void testIncomingAbortMessage() throws Exception {
 		expectIncomingMessage(Role.INVITEE, ABORT);
-		groupInvitationManager.incomingMessage(txn, message, body, meta);
+		assertEquals(ACCEPT_DO_NOT_SHARE, groupInvitationManager
+				.incomingMessage(txn, message, body, meta));
 	}
 
 	private void expectFirstIncomingMessage(Role role, MessageType type)

briar-core/src/test/java/org/briarproject/briar/test/BriarIntegrationTest.java

@@ -1,8 +1,5 @@
 package org.briarproject.briar.test;
 
-import net.jodah.concurrentunit.Waiter;
-
-import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.client.ClientHelper;
 import org.briarproject.bramble.api.client.ContactGroupFactory;
 import org.briarproject.bramble.api.contact.Contact;
@@ -10,13 +7,8 @@ import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.crypto.CryptoComponent;
 import org.briarproject.bramble.api.crypto.SecretKey;
-import org.briarproject.bramble.api.data.BdfList;
-import org.briarproject.bramble.api.data.BdfStringUtils;
 import org.briarproject.bramble.api.db.DatabaseComponent;
 import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.event.Event;
-import org.briarproject.bramble.api.event.EventBus;
-import org.briarproject.bramble.api.event.EventListener;
 import org.briarproject.bramble.api.identity.Identity;
 import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.identity.LocalAuthor;
@@ -25,11 +17,7 @@ import org.briarproject.bramble.api.nullsafety.MethodsNotNullByDefault;
 import org.briarproject.bramble.api.nullsafety.ParametersNotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageFactory;
 import org.briarproject.bramble.api.sync.MessageId;
-import org.briarproject.bramble.api.sync.event.MessageStateChangedEvent;
-import org.briarproject.bramble.api.sync.event.MessagesAckedEvent;
-import org.briarproject.bramble.api.sync.event.MessagesSentEvent;
-import org.briarproject.bramble.test.TestTransportConnectionReader;
-import org.briarproject.bramble.test.TestTransportConnectionWriter;
+import org.briarproject.bramble.test.BrambleIntegrationTest;
 import org.briarproject.bramble.test.TestUtils;
 import org.briarproject.briar.api.autodelete.AutoDeleteManager;
 import org.briarproject.briar.api.blog.BlogFactory;
@@ -43,48 +31,19 @@ import org.briarproject.briar.api.privategroup.invitation.GroupInvitationFactory
 import org.junit.After;
 import org.junit.Before;
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
 import java.io.File;
-import java.util.HashSet;
-import java.util.Set;
-import java.util.concurrent.CountDownLatch;
-import java.util.concurrent.Executor;
-import java.util.concurrent.Semaphore;
-import java.util.concurrent.atomic.AtomicInteger;
-import java.util.logging.Logger;
 
-import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import javax.inject.Inject;
 
-import static java.util.concurrent.Executors.newSingleThreadExecutor;
-import static java.util.concurrent.TimeUnit.MILLISECONDS;
-import static java.util.concurrent.TimeUnit.MINUTES;
-import static java.util.logging.Level.WARNING;
-import static java.util.logging.Logger.getLogger;
 import static junit.framework.Assert.assertNotNull;
-import static org.briarproject.bramble.api.sync.validation.MessageState.DELIVERED;
-import static org.briarproject.bramble.api.sync.validation.MessageState.INVALID;
-import static org.briarproject.bramble.api.sync.validation.MessageState.PENDING;
-import static org.briarproject.bramble.test.TestPluginConfigModule.SIMPLEX_TRANSPORT_ID;
 import static org.briarproject.bramble.test.TestUtils.getSecretKey;
-import static org.briarproject.bramble.util.LogUtils.logException;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.fail;
 
 @MethodsNotNullByDefault
 @ParametersNotNullByDefault
 public abstract class BriarIntegrationTest<C extends BriarIntegrationTestComponent>
-		extends BriarTestCase {
-
-	private static final Logger LOG =
-			getLogger(BriarIntegrationTest.class.getName());
-
-	private static final boolean DEBUG = false;
-
-	protected final static int TIMEOUT = 15000;
+		extends BrambleIntegrationTest<C> {
 
 	@Nullable
 	protected ContactId contactId1From2, contactId2From1;
@@ -94,7 +53,7 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 			contact2From0;
 	protected LocalAuthor author0, author1, author2;
 	protected ContactManager contactManager0, contactManager1, contactManager2;
-	protected IdentityManager identityManager0, identityManager1,
+	private IdentityManager identityManager0, identityManager1,
 			identityManager2;
 	protected DatabaseComponent db0, db1, db2;
 	protected MessageTracker messageTracker0, messageTracker1, messageTracker2;
@@ -123,18 +82,8 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 	@Inject
 	protected ForumPostFactory forumPostFactory;
 
-	// objects accessed from background threads need to be volatile
-	private volatile Waiter validationWaiter;
-	private volatile Waiter deliveryWaiter;
-	private volatile Waiter ackWaiter;
-	private volatile boolean expectAck = false;
-
 	protected C c0, c1, c2;
 
-	private final Semaphore messageSemaphore = new Semaphore(0);
-	private final AtomicInteger deliveryCounter = new AtomicInteger(0);
-	private final AtomicInteger validationCounter = new AtomicInteger(0);
-	private final AtomicInteger ackCounter = new AtomicInteger(0);
 	private final File testDir = TestUtils.getTestDirectory();
 	private final String AUTHOR0 = "Author 0";
 	private final String AUTHOR1 = "Author 1";
@@ -148,8 +97,9 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 	protected final File t2Dir = new File(testDir, AUTHOR2);
 
 	@Before
+	@Override
 	public void setUp() throws Exception {
-		assertTrue(testDir.mkdirs());
+		super.setUp();
 		createComponents();
 
 		identityManager0 = c0.getIdentityManager();
@@ -165,14 +115,6 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 		db1 = c1.getDatabaseComponent();
 		db2 = c2.getDatabaseComponent();
 
-		// initialize waiters fresh for each test
-		validationWaiter = new Waiter();
-		deliveryWaiter = new Waiter();
-		ackWaiter = new Waiter();
-		deliveryCounter.set(0);
-		validationCounter.set(0);
-		ackCounter.set(0);
-
 		createAndRegisterIdentities();
 		startLifecycles();
 		listenToEvents();
@@ -195,68 +137,9 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 	}
 
 	private void listenToEvents() {
-		Listener listener0 = new Listener(c0);
-		c0.getEventBus().addListener(listener0);
-		Listener listener1 = new Listener(c1);
-		c1.getEventBus().addListener(listener1);
-		Listener listener2 = new Listener(c2);
-		c2.getEventBus().addListener(listener2);
-	}
-
-	private class Listener implements EventListener {
-
-		private final ClientHelper clientHelper;
-		private final Executor executor;
-
-		private Listener(C c) {
-			clientHelper = c.getClientHelper();
-			executor = newSingleThreadExecutor();
-		}
-
-		@Override
-		public void eventOccurred(Event e) {
-			if (e instanceof MessageStateChangedEvent) {
-				MessageStateChangedEvent event = (MessageStateChangedEvent) e;
-				if (!event.isLocal()) {
-					if (event.getState() == DELIVERED) {
-						LOG.info("Delivered new message "
-								+ event.getMessageId());
-						deliveryCounter.addAndGet(1);
-						loadAndLogMessage(event.getMessageId());
-						deliveryWaiter.resume();
-					} else if (event.getState() == INVALID ||
-							event.getState() == PENDING) {
-						LOG.info("Validated new " + event.getState().name() +
-								" message " + event.getMessageId());
-						validationCounter.addAndGet(1);
-						loadAndLogMessage(event.getMessageId());
-						validationWaiter.resume();
-					}
-				}
-			} else if (e instanceof MessagesAckedEvent && expectAck) {
-				MessagesAckedEvent event = (MessagesAckedEvent) e;
-				ackCounter.addAndGet(event.getMessageIds().size());
-				for (MessageId m : event.getMessageIds()) {
-					loadAndLogMessage(m);
-					ackWaiter.resume();
-				}
-			}
-		}
-
-		private void loadAndLogMessage(MessageId id) {
-			executor.execute(() -> {
-				if (DEBUG) {
-					try {
-						BdfList body = clientHelper.getMessageAsList(id);
-						LOG.info("Contents of " + id + ":\n"
-								+ BdfStringUtils.toString(body));
-					} catch (DbException | FormatException e) {
-						logException(LOG, WARNING, e);
-					}
-				}
-				messageSemaphore.release();
-			});
-		}
+		addEventListener(c0);
+		addEventListener(c1);
+		addEventListener(c2);
 	}
 
 	private void createAndRegisterIdentities() {
@@ -335,9 +218,10 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 	}
 
 	@After
+	@Override
 	public void tearDown() throws Exception {
 		stopLifecycles();
-		TestUtils.deleteTestDirectory(testDir);
+		super.tearDown();
 	}
 
 	private void stopLifecycles() throws InterruptedException {
@@ -402,122 +286,6 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 		sendAcks(c1, c2, contactId2From1, num);
 	}
 
-	protected void syncMessage(BriarIntegrationTestComponent fromComponent,
-			BriarIntegrationTestComponent toComponent, ContactId toId, int num,
-			boolean valid) throws Exception {
-		syncMessage(fromComponent, toComponent, toId, num, 0, valid ? 0 : num,
-				valid ? num : 0);
-	}
-
-	protected void syncMessage(BriarIntegrationTestComponent fromComponent,
-			BriarIntegrationTestComponent toComponent, ContactId toId,
-			int numNew, int numDupes, int numPendingOrInvalid, int numDelivered)
-			throws Exception {
-
-		// Debug output
-		String from =
-				fromComponent.getIdentityManager().getLocalAuthor().getName();
-		String to = toComponent.getIdentityManager().getLocalAuthor().getName();
-		LOG.info("TEST: Sending " + (numNew + numDupes) + " message(s) from "
-				+ from + " to " + to);
-
-		// Listen for messages being sent
-		waitForEvents(fromComponent);
-		SendListener sendListener = new SendListener();
-		fromComponent.getEventBus().addListener(sendListener);
-
-		// Write the messages to a transport stream
-		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		TestTransportConnectionWriter writer =
-				new TestTransportConnectionWriter(out);
-		fromComponent.getConnectionManager().manageOutgoingConnection(toId,
-				SIMPLEX_TRANSPORT_ID, writer);
-		writer.getDisposedLatch().await(TIMEOUT, MILLISECONDS);
-
-		// Check that the expected number of messages were sent
-		waitForEvents(fromComponent);
-		fromComponent.getEventBus().removeListener(sendListener);
-		assertEquals("Messages sent", numNew + numDupes,
-				sendListener.sent.size());
-
-		// Read the messages from the transport stream
-		ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
-		TestTransportConnectionReader reader =
-				new TestTransportConnectionReader(in);
-		toComponent.getConnectionManager().manageIncomingConnection(
-				SIMPLEX_TRANSPORT_ID, reader);
-
-		if (numPendingOrInvalid > 0) {
-			validationWaiter.await(TIMEOUT, numPendingOrInvalid);
-		}
-		assertEquals("Messages validated", numPendingOrInvalid,
-				validationCounter.getAndSet(0));
-
-		if (numDelivered > 0) {
-			deliveryWaiter.await(TIMEOUT, numDelivered);
-		}
-		assertEquals("Messages delivered", numDelivered,
-				deliveryCounter.getAndSet(0));
-
-		try {
-			messageSemaphore.tryAcquire(numNew, TIMEOUT, MILLISECONDS);
-		} catch (InterruptedException e) {
-			LOG.info("Interrupted while waiting for messages");
-			Thread.currentThread().interrupt();
-			fail();
-		}
-	}
-
-	protected void sendAcks(BriarIntegrationTestComponent fromComponent,
-			BriarIntegrationTestComponent toComponent, ContactId toId, int num)
-			throws Exception {
-		// Debug output
-		String from =
-				fromComponent.getIdentityManager().getLocalAuthor().getName();
-		String to = toComponent.getIdentityManager().getLocalAuthor().getName();
-		LOG.info("TEST: Sending " + num + " ACKs from " + from + " to " + to);
-
-		expectAck = true;
-
-		// Listen for messages being sent (none should be sent)
-		waitForEvents(fromComponent);
-		SendListener sendListener = new SendListener();
-		fromComponent.getEventBus().addListener(sendListener);
-
-		// start outgoing connection
-		ByteArrayOutputStream out = new ByteArrayOutputStream();
-		TestTransportConnectionWriter writer =
-				new TestTransportConnectionWriter(out);
-		fromComponent.getConnectionManager().manageOutgoingConnection(toId,
-				SIMPLEX_TRANSPORT_ID, writer);
-		writer.getDisposedLatch().await(TIMEOUT, MILLISECONDS);
-
-		// Check that no messages were sent
-		waitForEvents(fromComponent);
-		fromComponent.getEventBus().removeListener(sendListener);
-		assertEquals("Messages sent", 0, sendListener.sent.size());
-
-		// handle incoming connection
-		ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
-		TestTransportConnectionReader reader =
-				new TestTransportConnectionReader(in);
-		toComponent.getConnectionManager().manageIncomingConnection(
-				SIMPLEX_TRANSPORT_ID, reader);
-
-		ackWaiter.await(TIMEOUT, num);
-		assertEquals("ACKs delivered", num, ackCounter.getAndSet(0));
-		assertEquals("No messages delivered", 0, deliveryCounter.get());
-		try {
-			messageSemaphore.tryAcquire(num, TIMEOUT, MILLISECONDS);
-		} catch (InterruptedException e) {
-			LOG.info("Interrupted while waiting for messages");
-			Thread.currentThread().interrupt();
-			fail();
-		} finally {
-			expectAck = false;
-		}
-	}
-
 	protected void removeAllContacts() throws DbException {
 		contactManager0.removeContact(contactId1From0);
 		contactManager0.removeContact(contactId2From0);
@@ -562,40 +330,4 @@ public abstract class BriarIntegrationTest<C extends BriarIntegrationTestCompone
 		db.transaction(false, txn -> db.setMessageShared(txn, messageId));
 	}
 
-	/**
-	 * Broadcasts a marker event and waits for it to be delivered, which
-	 * indicates that all previously broadcast events have been delivered.
-	 */
-	public static void waitForEvents(BriarIntegrationTestComponent component)
-			throws Exception {
-		CountDownLatch latch = new CountDownLatch(1);
-		MarkerEvent marker = new MarkerEvent();
-		EventBus eventBus = component.getEventBus();
-		eventBus.addListener(new EventListener() {
-			@Override
-			public void eventOccurred(@Nonnull Event e) {
-				if (e == marker) {
-					latch.countDown();
-					eventBus.removeListener(this);
-				}
-			}
-		});
-		eventBus.broadcast(marker);
-		if (!latch.await(1, MINUTES)) fail();
-	}
-
-	private static class MarkerEvent extends Event {
-	}
-
-	private static class SendListener implements EventListener {
-
-		private final Set<MessageId> sent = new HashSet<>();
-
-		@Override
-		public void eventOccurred(Event e) {
-			if (e instanceof MessagesSentEvent) {
-				sent.addAll(((MessagesSentEvent) e).getMessageIds());
-			}
-		}
-	}
 }

briar-core/src/test/java/org/briarproject/briar/test/BriarIntegrationTestComponent.java

@@ -2,17 +2,14 @@ package org.briarproject.briar.test;
 
 import org.briarproject.bramble.BrambleCoreIntegrationTestEagerSingletons;
 import org.briarproject.bramble.BrambleCoreModule;
-import org.briarproject.bramble.api.client.ClientHelper;
-import org.briarproject.bramble.api.connection.ConnectionManager;
 import org.briarproject.bramble.api.contact.ContactManager;
 import org.briarproject.bramble.api.db.DatabaseComponent;
-import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.identity.AuthorFactory;
-import org.briarproject.bramble.api.identity.IdentityManager;
 import org.briarproject.bramble.api.lifecycle.LifecycleManager;
 import org.briarproject.bramble.api.properties.TransportPropertyManager;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.test.BrambleCoreIntegrationTestModule;
+import org.briarproject.bramble.test.BrambleIntegrationTestComponent;
 import org.briarproject.bramble.test.TimeTravel;
 import org.briarproject.briar.api.attachment.AttachmentReader;
 import org.briarproject.briar.api.autodelete.AutoDeleteManager;
@@ -67,7 +64,7 @@ import dagger.Component;
 		SharingModule.class
 })
 public interface BriarIntegrationTestComponent
-		extends BrambleCoreIntegrationTestEagerSingletons {
+		extends BrambleIntegrationTestComponent {
 
 	void inject(BriarIntegrationTest<BriarIntegrationTestComponent> init);
 
@@ -95,16 +92,10 @@ public interface BriarIntegrationTestComponent
 
 	LifecycleManager getLifecycleManager();
 
-	EventBus getEventBus();
-
-	IdentityManager getIdentityManager();
-
 	AttachmentReader getAttachmentReader();
 
 	AvatarManager getAvatarManager();
 
-	ClientHelper getClientHelper();
-
 	ContactManager getContactManager();
 
 	ConversationManager getConversationManager();
@@ -139,8 +130,6 @@ public interface BriarIntegrationTestComponent
 
 	BlogFactory getBlogFactory();
 
-	ConnectionManager getConnectionManager();
-
 	AutoDeleteManager getAutoDeleteManager();
 
 	Clock getClock();