Update blog and forum sharing clients to include self-destruct timers.

briar-api/src/main/java/org/briarproject/briar/api/blog/BlogInvitationRequest.java

@@ -15,9 +15,9 @@ public class BlogInvitationRequest extends InvitationRequest<Blog> {
 	public BlogInvitationRequest(MessageId id, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
 			SessionId sessionId, Blog blog, @Nullable String text,
-			boolean available, boolean canBeOpened) {
+			boolean available, boolean canBeOpened, long autoDeleteTimer) {
 		super(id, groupId, time, local, read, sent, seen, sessionId, blog,
-				text, available, canBeOpened);
+				text, available, canBeOpened, autoDeleteTimer);
 	}
 
 	@Override

briar-api/src/main/java/org/briarproject/briar/api/blog/BlogInvitationResponse.java

@@ -12,9 +12,10 @@ public class BlogInvitationResponse extends InvitationResponse {
 
 	public BlogInvitationResponse(MessageId id, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
-			SessionId sessionId, boolean accept, GroupId shareableId) {
+			SessionId sessionId, boolean accept, GroupId shareableId,
+			long autoDeleteTimer) {
 		super(id, groupId, time, local, read, sent, seen, sessionId,
-				accept, shareableId);
+				accept, shareableId, autoDeleteTimer);
 	}
 
 	@Override

briar-api/src/main/java/org/briarproject/briar/api/blog/BlogSharingManager.java

@@ -18,5 +18,5 @@ public interface BlogSharingManager extends SharingManager<Blog> {
 	/**
 	 * The current minor version of the blog sharing client.
 	 */
-	int MINOR_VERSION = 0;
+	int MINOR_VERSION = 1;
 }

briar-api/src/main/java/org/briarproject/briar/api/forum/ForumInvitationRequest.java

@@ -17,9 +17,9 @@ public class ForumInvitationRequest extends InvitationRequest<Forum> {
 	public ForumInvitationRequest(MessageId id, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
 			SessionId sessionId, Forum forum, @Nullable String text,
-			boolean available, boolean canBeOpened) {
+			boolean available, boolean canBeOpened, long autoDeleteTimer) {
 		super(id, groupId, time, local, read, sent, seen, sessionId, forum,
-				text, available, canBeOpened);
+				text, available, canBeOpened, autoDeleteTimer);
 	}
 
 	@Override

briar-api/src/main/java/org/briarproject/briar/api/forum/ForumInvitationResponse.java

@@ -15,9 +15,10 @@ public class ForumInvitationResponse extends InvitationResponse {
 
 	public ForumInvitationResponse(MessageId id, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
-			SessionId sessionId, boolean accept, GroupId shareableId) {
+			SessionId sessionId, boolean accept, GroupId shareableId,
+			long autoDeleteTimer) {
 		super(id, groupId, time, local, read, sent, seen, sessionId,
-				accept, shareableId);
+				accept, shareableId, autoDeleteTimer);
 	}
 
 	@Override

briar-api/src/main/java/org/briarproject/briar/api/forum/ForumSharingManager.java

@@ -18,5 +18,5 @@ public interface ForumSharingManager extends SharingManager<Forum> {
 	/**
 	 * The current minor version of the forum sharing client.
 	 */
-	int MINOR_VERSION = 0;
+	int MINOR_VERSION = 1;
 }

briar-api/src/main/java/org/briarproject/briar/api/privategroup/invitation/GroupInvitationRequest.java

@@ -11,6 +11,8 @@ import org.briarproject.briar.api.sharing.InvitationRequest;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
+
 @Immutable
 @NotNullByDefault
 public class GroupInvitationRequest extends InvitationRequest<PrivateGroup> {
@@ -20,7 +22,7 @@ public class GroupInvitationRequest extends InvitationRequest<PrivateGroup> {
 			SessionId sessionId, PrivateGroup shareable,
 			@Nullable String text, boolean available, boolean canBeOpened) {
 		super(id, groupId, time, local, read, sent, seen, sessionId, shareable,
-				text, available, canBeOpened);
+				text, available, canBeOpened, NO_AUTO_DELETE_TIMER);
 	}
 
 	@Override

briar-api/src/main/java/org/briarproject/briar/api/privategroup/invitation/GroupInvitationResponse.java

@@ -9,6 +9,8 @@ import org.briarproject.briar.api.sharing.InvitationResponse;
 
 import javax.annotation.concurrent.Immutable;
 
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
+
 @Immutable
 @NotNullByDefault
 public class GroupInvitationResponse extends InvitationResponse {
@@ -17,7 +19,7 @@ public class GroupInvitationResponse extends InvitationResponse {
 			boolean local, boolean read, boolean sent, boolean seen,
 			SessionId sessionId, boolean accept, GroupId shareableId) {
 		super(id, groupId, time, local, read, sent, seen, sessionId,
-				accept, shareableId);
+				accept, shareableId, NO_AUTO_DELETE_TIMER);
 	}
 
 	@Override

briar-api/src/main/java/org/briarproject/briar/api/sharing/InvitationRequest.java

@@ -7,8 +7,6 @@ import org.briarproject.briar.api.conversation.ConversationRequest;
 
 import javax.annotation.Nullable;
 
-import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
-
 public abstract class InvitationRequest<S extends Shareable> extends
 		ConversationRequest<S> {
 
@@ -17,9 +15,9 @@ public abstract class InvitationRequest<S extends Shareable> extends
 	public InvitationRequest(MessageId messageId, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
 			SessionId sessionId, S object, @Nullable String text,
-			boolean available, boolean canBeOpened) {
+			boolean available, boolean canBeOpened, long autoDeleteTimer) {
 		super(messageId, groupId, time, local, read, sent, seen, sessionId,
-				object, text, !available, NO_AUTO_DELETE_TIMER);
+				object, text, !available, autoDeleteTimer);
 		this.canBeOpened = canBeOpened;
 	}
 

briar-api/src/main/java/org/briarproject/briar/api/sharing/InvitationResponse.java

@@ -5,17 +5,16 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.conversation.ConversationResponse;
 
-import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
-
 public abstract class InvitationResponse extends ConversationResponse {
 
 	private final GroupId shareableId;
 
 	public InvitationResponse(MessageId id, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
-			SessionId sessionId, boolean accepted, GroupId shareableId) {
+			SessionId sessionId, boolean accepted, GroupId shareableId,
+			long autoDeleteTimer) {
 		super(id, groupId, time, local, read, sent, seen, sessionId, accepted,
-				NO_AUTO_DELETE_TIMER);
+				autoDeleteTimer);
 		this.shareableId = shareableId;
 	}
 

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

@@ -9,11 +9,13 @@ import javax.annotation.concurrent.Immutable;
 
 @Immutable
 @NotNullByDefault
-class AcceptMessage extends SharingMessage {
+class AcceptMessage extends DeletableSharingMessage {
 
 	AcceptMessage(MessageId id, @Nullable MessageId previousMessageId,
-			GroupId contactGroupId, GroupId shareableId, long timestamp) {
-		super(id, contactGroupId, shareableId, timestamp, previousMessageId);
+			GroupId contactGroupId, GroupId shareableId, long timestamp,
+			long autoDeleteTimer) {
+		super(id, contactGroupId, shareableId, timestamp, previousMessageId,
+				autoDeleteTimer);
 	}
 
 }

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

@@ -20,20 +20,24 @@ public class BlogInvitationFactoryImpl
 	@Override
 	public BlogInvitationRequest createInvitationRequest(boolean local,
 			boolean sent, boolean seen, boolean read, InviteMessage<Blog> m,
-			ContactId c, boolean available, boolean canBeOpened) {
+			ContactId c, boolean available, boolean canBeOpened,
+			long autoDeleteTimer) {
 		SessionId sessionId = new SessionId(m.getShareableId().getBytes());
 		return new BlogInvitationRequest(m.getId(), m.getContactGroupId(),
 				m.getTimestamp(), local, read, sent, seen, sessionId,
-				m.getShareable(), m.getText(), available, canBeOpened);
+				m.getShareable(), m.getText(), available, canBeOpened,
+				autoDeleteTimer);
 	}
 
 	@Override
 	public BlogInvitationResponse createInvitationResponse(MessageId id,
 			GroupId contactGroupId, long time, boolean local, boolean sent,
-			boolean seen, boolean read, boolean accept, GroupId shareableId) {
+			boolean seen, boolean read, boolean accept, GroupId shareableId,
+			long autoDeleteTimer) {
 		SessionId sessionId = new SessionId(shareableId.getBytes());
 		return new BlogInvitationResponse(id, contactGroupId, time, local, read,
-				sent, seen, sessionId, accept, shareableId);
+				sent, seen, sessionId, accept, shareableId,
+				autoDeleteTimer);
 	}
 
 }

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

@@ -8,13 +8,13 @@ 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.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
 import org.briarproject.briar.api.blog.Blog;
 import org.briarproject.briar.api.blog.BlogInvitationResponse;
 import org.briarproject.briar.api.blog.BlogManager;
+import org.briarproject.briar.api.blog.BlogSharingManager;
 import org.briarproject.briar.api.blog.event.BlogInvitationRequestReceivedEvent;
 import org.briarproject.briar.api.blog.event.BlogInvitationResponseReceivedEvent;
 import org.briarproject.briar.api.client.MessageTracker;
@@ -23,9 +23,6 @@ import org.briarproject.briar.api.conversation.ConversationRequest;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
-import static org.briarproject.briar.api.blog.BlogManager.CLIENT_ID;
-import static org.briarproject.briar.api.blog.BlogManager.MAJOR_VERSION;
-
 @Immutable
 @NotNullByDefault
 class BlogProtocolEngineImpl extends ProtocolEngineImpl<Blog> {
@@ -41,8 +38,9 @@ class BlogProtocolEngineImpl extends ProtocolEngineImpl<Blog> {
 			MessageTracker messageTracker, Clock clock, BlogManager blogManager,
 			InvitationFactory<Blog, BlogInvitationResponse> invitationFactory) {
 		super(db, clientHelper, clientVersioningManager, messageEncoder,
-				messageParser, messageTracker, clock, CLIENT_ID,
-				MAJOR_VERSION);
+				messageParser, messageTracker, clock,
+				BlogSharingManager.CLIENT_ID, BlogSharingManager.MAJOR_VERSION,
+				BlogManager.CLIENT_ID, BlogManager.MAJOR_VERSION);
 		this.blogManager = blogManager;
 		this.invitationFactory = invitationFactory;
 	}
@@ -52,7 +50,8 @@ class BlogProtocolEngineImpl extends ProtocolEngineImpl<Blog> {
 			ContactId contactId, boolean available, boolean canBeOpened) {
 		ConversationRequest<Blog> request = invitationFactory
 				.createInvitationRequest(false, false, true, false, m,
-						contactId, available, canBeOpened);
+						contactId, available, canBeOpened,
+						m.getAutoDeleteTimer());
 		return new BlogInvitationRequestReceivedEvent(request, contactId);
 	}
 
@@ -62,7 +61,7 @@ class BlogProtocolEngineImpl extends ProtocolEngineImpl<Blog> {
 		BlogInvitationResponse response = invitationFactory
 				.createInvitationResponse(m.getId(), m.getContactGroupId(),
 						m.getTimestamp(), false, false, false, false,
-						true, m.getShareableId());
+						true, m.getShareableId(), m.getAutoDeleteTimer());
 		return new BlogInvitationResponseReceivedEvent(response, contactId);
 	}
 
@@ -72,15 +71,10 @@ class BlogProtocolEngineImpl extends ProtocolEngineImpl<Blog> {
 		BlogInvitationResponse response = invitationFactory
 				.createInvitationResponse(m.getId(), m.getContactGroupId(),
 						m.getTimestamp(), false, false, false, false,
-						false, m.getShareableId());
+						false, m.getShareableId(), m.getAutoDeleteTimer());
 		return new BlogInvitationResponseReceivedEvent(response, contactId);
 	}
 
-	@Override
-	protected ClientId getShareableClientId() {
-		return CLIENT_ID;
-	}
-
 	@Override
 	protected void addShareable(Transaction txn, MessageId inviteId)
 			throws DbException, FormatException {

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

@@ -9,12 +9,13 @@ import javax.annotation.concurrent.Immutable;
 
 @Immutable
 @NotNullByDefault
-class DeclineMessage extends SharingMessage {
+class DeclineMessage extends DeletableSharingMessage {
 
 	DeclineMessage(MessageId id, GroupId contactGroupId,
 			GroupId shareableId, long timestamp,
-			@Nullable MessageId previousMessageId) {
-		super(id, contactGroupId, shareableId, timestamp, previousMessageId);
+			@Nullable MessageId previousMessageId, long autoDeleteTimer) {
+		super(id, contactGroupId, shareableId, timestamp, previousMessageId,
+				autoDeleteTimer);
 	}
 
 }

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

@@ -0,0 +1,22 @@
+package org.briarproject.briar.sharing;
+
+import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.sync.MessageId;
+
+import javax.annotation.Nullable;
+
+abstract class DeletableSharingMessage extends SharingMessage {
+
+	private final long autoDeleteTimer;
+
+	DeletableSharingMessage(MessageId id, GroupId contactGroupId,
+			GroupId shareableId, long timestamp,
+			@Nullable MessageId previousMessageId, long autoDeleteTimer) {
+		super(id, contactGroupId, shareableId, timestamp, previousMessageId);
+		this.autoDeleteTimer = autoDeleteTimer;
+	}
+
+	public long getAutoDeleteTimer() {
+		return autoDeleteTimer;
+	}
+}

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

@@ -20,20 +20,24 @@ public class ForumInvitationFactoryImpl
 	@Override
 	public ForumInvitationRequest createInvitationRequest(boolean local,
 			boolean sent, boolean seen, boolean read, InviteMessage<Forum> m,
-			ContactId c, boolean available, boolean canBeOpened) {
+			ContactId c, boolean available, boolean canBeOpened,
+			long autoDeleteTimer) {
 		SessionId sessionId = new SessionId(m.getShareableId().getBytes());
 		return new ForumInvitationRequest(m.getId(), m.getContactGroupId(),
 				m.getTimestamp(), local, read, sent, seen, sessionId,
-				m.getShareable(), m.getText(), available, canBeOpened);
+				m.getShareable(), m.getText(), available, canBeOpened,
+				autoDeleteTimer);
 	}
 
 	@Override
 	public ForumInvitationResponse createInvitationResponse(MessageId id,
 			GroupId contactGroupId, long time, boolean local, boolean sent,
-			boolean seen, boolean read, boolean accept, GroupId shareableId) {
+			boolean seen, boolean read, boolean accept, GroupId shareableId,
+			long autoDeleteTimer) {
 		SessionId sessionId = new SessionId(shareableId.getBytes());
 		return new ForumInvitationResponse(id, contactGroupId, time, local,
-				read, sent, seen, sessionId, accept, shareableId);
+				read, sent, seen, sessionId, accept, shareableId,
+				autoDeleteTimer);
 	}
 
 }

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

@@ -8,7 +8,6 @@ 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.nullsafety.NotNullByDefault;
-import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.system.Clock;
 import org.briarproject.bramble.api.versioning.ClientVersioningManager;
@@ -17,21 +16,20 @@ import org.briarproject.briar.api.conversation.ConversationRequest;
 import org.briarproject.briar.api.forum.Forum;
 import org.briarproject.briar.api.forum.ForumInvitationResponse;
 import org.briarproject.briar.api.forum.ForumManager;
+import org.briarproject.briar.api.forum.ForumSharingManager;
 import org.briarproject.briar.api.forum.event.ForumInvitationRequestReceivedEvent;
 import org.briarproject.briar.api.forum.event.ForumInvitationResponseReceivedEvent;
 
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
-import static org.briarproject.briar.api.forum.ForumManager.CLIENT_ID;
-import static org.briarproject.briar.api.forum.ForumManager.MAJOR_VERSION;
-
 @Immutable
 @NotNullByDefault
 class ForumProtocolEngineImpl extends ProtocolEngineImpl<Forum> {
 
 	private final ForumManager forumManager;
-	private final InvitationFactory<Forum, ForumInvitationResponse> invitationFactory;
+	private final InvitationFactory<Forum, ForumInvitationResponse>
+			invitationFactory;
 
 	@Inject
 	ForumProtocolEngineImpl(DatabaseComponent db,
@@ -42,8 +40,10 @@ class ForumProtocolEngineImpl extends ProtocolEngineImpl<Forum> {
 			ForumManager forumManager,
 			InvitationFactory<Forum, ForumInvitationResponse> invitationFactory) {
 		super(db, clientHelper, clientVersioningManager, messageEncoder,
-				messageParser, messageTracker, clock, CLIENT_ID,
-				MAJOR_VERSION);
+				messageParser, messageTracker, clock,
+				ForumSharingManager.CLIENT_ID,
+				ForumSharingManager.MAJOR_VERSION,
+				ForumManager.CLIENT_ID, ForumManager.MAJOR_VERSION);
 		this.forumManager = forumManager;
 		this.invitationFactory = invitationFactory;
 	}
@@ -53,7 +53,8 @@ class ForumProtocolEngineImpl extends ProtocolEngineImpl<Forum> {
 			ContactId contactId, boolean available, boolean canBeOpened) {
 		ConversationRequest<Forum> request = invitationFactory
 				.createInvitationRequest(false, false, true, false, m,
-						contactId, available, canBeOpened);
+						contactId, available, canBeOpened,
+						m.getAutoDeleteTimer());
 		return new ForumInvitationRequestReceivedEvent(request, contactId);
 	}
 
@@ -63,7 +64,7 @@ class ForumProtocolEngineImpl extends ProtocolEngineImpl<Forum> {
 		ForumInvitationResponse response = invitationFactory
 				.createInvitationResponse(m.getId(), m.getContactGroupId(),
 						m.getTimestamp(), false, false, true, false,
-						true, m.getShareableId());
+						true, m.getShareableId(), m.getAutoDeleteTimer());
 		return new ForumInvitationResponseReceivedEvent(response, contactId);
 	}
 
@@ -73,15 +74,10 @@ class ForumProtocolEngineImpl extends ProtocolEngineImpl<Forum> {
 		ForumInvitationResponse response = invitationFactory
 				.createInvitationResponse(m.getId(), m.getContactGroupId(),
 						m.getTimestamp(), false, false, true, false,
-						false, m.getShareableId());
+						false, m.getShareableId(), m.getAutoDeleteTimer());
 		return new ForumInvitationResponseReceivedEvent(response, contactId);
 	}
 
-	@Override
-	protected ClientId getShareableClientId() {
-		return CLIENT_ID;
-	}
-
 	@Override
 	protected void addShareable(Transaction txn, MessageId inviteId)
 			throws DbException, FormatException {

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

@@ -11,10 +11,10 @@ public interface InvitationFactory<S extends Shareable, R extends InvitationResp
 
 	ConversationRequest<S> createInvitationRequest(boolean local, boolean sent,
 			boolean seen, boolean read, InviteMessage<S> m, ContactId c,
-			boolean available, boolean canBeOpened);
+			boolean available, boolean canBeOpened, long autoDeleteTimer);
 
 	R createInvitationResponse(MessageId id, GroupId contactGroupId, long time,
 			boolean local, boolean sent, boolean seen, boolean read,
-			boolean accept, GroupId shareableId);
+			boolean accept, GroupId shareableId, long autoDeleteTimer);
 
 }

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

@@ -10,7 +10,7 @@ import javax.annotation.concurrent.Immutable;
 
 @Immutable
 @NotNullByDefault
-class InviteMessage<S extends Shareable> extends SharingMessage {
+class InviteMessage<S extends Shareable> extends DeletableSharingMessage {
 
 	private final S shareable;
 	@Nullable
@@ -18,9 +18,9 @@ class InviteMessage<S extends Shareable> extends SharingMessage {
 
 	InviteMessage(MessageId id, @Nullable MessageId previousMessageId,
 			GroupId contactGroupId, S shareable, @Nullable String text,
-			long timestamp) {
+			long timestamp, long autoDeleteTimer) {
 		super(id, contactGroupId, shareable.getId(), timestamp,
-				previousMessageId);
+				previousMessageId, autoDeleteTimer);
 		if (text != null && text.isEmpty())
 			throw new IllegalArgumentException();
 		this.shareable = shareable;

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

@@ -14,7 +14,7 @@ interface MessageEncoder {
 
 	BdfDictionary encodeMetadata(MessageType type, GroupId shareableId,
 			long timestamp, boolean local, boolean read, boolean visible,
-			boolean available, boolean accepted);
+			boolean available, boolean accepted, long autoDeleteTimer);
 
 	void setVisibleInUi(BdfDictionary meta, boolean visible);
 
@@ -22,16 +22,49 @@ interface MessageEncoder {
 
 	void setInvitationAccepted(BdfDictionary meta, boolean accepted);
 
+	/**
+	 * Encodes an invite message without an auto-delete timer.
+	 */
 	Message encodeInviteMessage(GroupId contactGroupId, long timestamp,
 			@Nullable MessageId previousMessageId, BdfList descriptor,
 			@Nullable String text);
 
+	/**
+	 * Encodes an invite message with an optional auto-delete timer. This
+	 * requires the contact to support client version 0.1 or higher.
+	 */
+	Message encodeInviteMessage(GroupId contactGroupId, long timestamp,
+			@Nullable MessageId previousMessageId, BdfList descriptor,
+			@Nullable String text, long autoDeleteTimer);
+
+	/**
+	 * Encodes an accept message without an auto-delete timer.
+	 */
 	Message encodeAcceptMessage(GroupId contactGroupId, GroupId shareableId,
 			long timestamp, @Nullable MessageId previousMessageId);
 
+	/**
+	 * Encodes an accept message with an optional auto-delete timer. This
+	 * requires the contact to support client version 0.1 or higher.
+	 */
+	Message encodeAcceptMessage(GroupId contactGroupId, GroupId shareableId,
+			long timestamp, @Nullable MessageId previousMessageId,
+			long autoDeleteTimer);
+
+	/**
+	 * Encodes a decline message without an auto-delete timer.
+	 */
 	Message encodeDeclineMessage(GroupId contactGroupId, GroupId shareableId,
 			long timestamp, @Nullable MessageId previousMessageId);
 
+	/**
+	 * Encodes a decline message with an optional auto-delete timer. This
+	 * requires the contact to support client version 0.1 or higher.
+	 */
+	Message encodeDeclineMessage(GroupId contactGroupId, GroupId shareableId,
+			long timestamp, @Nullable MessageId previousMessageId,
+			long autoDeleteTimer);
+
 	Message encodeLeaveMessage(GroupId contactGroupId, GroupId shareableId,
 			long timestamp, @Nullable MessageId previousMessageId);
 

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

@@ -14,11 +14,13 @@ import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 import javax.inject.Inject;
 
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 import static org.briarproject.briar.sharing.MessageType.ABORT;
 import static org.briarproject.briar.sharing.MessageType.ACCEPT;
 import static org.briarproject.briar.sharing.MessageType.DECLINE;
 import static org.briarproject.briar.sharing.MessageType.INVITE;
 import static org.briarproject.briar.sharing.MessageType.LEAVE;
+import static org.briarproject.briar.sharing.SharingConstants.MSG_KEY_AUTO_DELETE_TIMER;
 import static org.briarproject.briar.sharing.SharingConstants.MSG_KEY_AVAILABLE_TO_ANSWER;
 import static org.briarproject.briar.sharing.SharingConstants.MSG_KEY_INVITATION_ACCEPTED;
 import static org.briarproject.briar.sharing.SharingConstants.MSG_KEY_LOCAL;
@@ -45,7 +47,8 @@ class MessageEncoderImpl implements MessageEncoder {
 	@Override
 	public BdfDictionary encodeMetadata(MessageType type,
 			GroupId shareableId, long timestamp, boolean local, boolean read,
-			boolean visible, boolean available, boolean accepted) {
+			boolean visible, boolean available, boolean accepted,
+			long autoDeleteTimer) {
 		BdfDictionary meta = new BdfDictionary();
 		meta.put(MSG_KEY_MESSAGE_TYPE, type.getValue());
 		meta.put(MSG_KEY_SHAREABLE_ID, shareableId);
@@ -55,6 +58,9 @@ class MessageEncoderImpl implements MessageEncoder {
 		meta.put(MSG_KEY_VISIBLE_IN_UI, visible);
 		meta.put(MSG_KEY_AVAILABLE_TO_ANSWER, available);
 		meta.put(MSG_KEY_INVITATION_ACCEPTED, accepted);
+		if (autoDeleteTimer != NO_AUTO_DELETE_TIMER) {
+			meta.put(MSG_KEY_AUTO_DELETE_TIMER, autoDeleteTimer);
+		}
 		return meta;
 	}
 
@@ -93,6 +99,27 @@ class MessageEncoderImpl implements MessageEncoder {
 		}
 	}
 
+	@Override
+	public Message encodeInviteMessage(GroupId contactGroupId, long timestamp,
+			@Nullable MessageId previousMessageId, BdfList descriptor,
+			@Nullable String text, long autoDeleteTimer) {
+		if (text != null && text.isEmpty())
+			throw new IllegalArgumentException();
+		BdfList body = BdfList.of(
+				INVITE.getValue(),
+				previousMessageId,
+				descriptor,
+				text,
+				encodeTimer(autoDeleteTimer)
+		);
+		try {
+			return messageFactory.createMessage(contactGroupId, timestamp,
+					clientHelper.toByteArray(body));
+		} catch (FormatException e) {
+			throw new AssertionError(e);
+		}
+	}
+
 	@Override
 	public Message encodeAcceptMessage(GroupId contactGroupId,
 			GroupId shareableId, long timestamp,
@@ -101,6 +128,14 @@ class MessageEncoderImpl implements MessageEncoder {
 				previousMessageId);
 	}
 
+	@Override
+	public Message encodeAcceptMessage(GroupId contactGroupId,
+			GroupId shareableId, long timestamp,
+			@Nullable MessageId previousMessageId, long autoDeleteTimer) {
+		return encodeMessage(ACCEPT, contactGroupId, shareableId, timestamp,
+				previousMessageId, autoDeleteTimer);
+	}
+
 	@Override
 	public Message encodeDeclineMessage(GroupId contactGroupId,
 			GroupId shareableId, long timestamp,
@@ -109,6 +144,14 @@ class MessageEncoderImpl implements MessageEncoder {
 				previousMessageId);
 	}
 
+	@Override
+	public Message encodeDeclineMessage(GroupId contactGroupId,
+			GroupId shareableId, long timestamp,
+			@Nullable MessageId previousMessageId, long autoDeleteTimer) {
+		return encodeMessage(DECLINE, contactGroupId, shareableId, timestamp,
+				previousMessageId, autoDeleteTimer);
+	}
+
 	@Override
 	public Message encodeLeaveMessage(GroupId contactGroupId,
 			GroupId shareableId, long timestamp,
@@ -141,4 +184,25 @@ class MessageEncoderImpl implements MessageEncoder {
 		}
 	}
 
+	private Message encodeMessage(MessageType type, GroupId contactGroupId,
+			GroupId shareableId, long timestamp,
+			@Nullable MessageId previousMessageId, long autoDeleteTimer) {
+		BdfList body = BdfList.of(
+				type.getValue(),
+				shareableId,
+				previousMessageId,
+				encodeTimer(autoDeleteTimer)
+		);
+		try {
+			return messageFactory.createMessage(contactGroupId, timestamp,
+					clientHelper.toByteArray(body));
+		} catch (FormatException e) {
+			throw new AssertionError(e);
+		}
+	}
+
+	@Nullable
+	private Long encodeTimer(long autoDeleteTimer) {
+		return autoDeleteTimer == NO_AUTO_DELETE_TIMER ? null : autoDeleteTimer;
+	}
 }

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

@@ -11,12 +11,12 @@ class MessageMetadata {
 
 	private final MessageType type;
 	private final GroupId shareableId;
-	private final long timestamp;
+	private final long timestamp, autoDeleteTimer;
 	private final boolean local, read, visible, available, accepted;
 
 	MessageMetadata(MessageType type, GroupId shareableId, long timestamp,
 			boolean local, boolean read, boolean visible, boolean available,
-			boolean accepted) {
+			boolean accepted, long autoDeleteTimer) {
 		this.shareableId = shareableId;
 		this.type = type;
 		this.timestamp = timestamp;
@@ -25,6 +25,7 @@ class MessageMetadata {
 		this.visible = visible;
 		this.available = available;
 		this.accepted = accepted;
+		this.autoDeleteTimer = autoDeleteTimer;
 	}
 
 	MessageType getMessageType() {
@@ -64,4 +65,7 @@ class MessageMetadata {
 		return accepted;
 	}
 
+	public long getAutoDeleteTimer() {
+		return autoDeleteTimer;
+	}
 }

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

@@ -15,7 +15,9 @@ import org.briarproject.briar.api.sharing.Shareable;
 
 import javax.annotation.concurrent.Immutable;
 
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 import static org.briarproject.briar.sharing.MessageType.INVITE;
+import static org.briarproject.briar.sharing.SharingConstants.MSG_KEY_AUTO_DELETE_TIMER;
 import static org.briarproject.briar.sharing.SharingConstants.MSG_KEY_AVAILABLE_TO_ANSWER;
 import static org.briarproject.briar.sharing.SharingConstants.MSG_KEY_INVITATION_ACCEPTED;
 import static org.briarproject.briar.sharing.SharingConstants.MSG_KEY_LOCAL;
@@ -70,8 +72,10 @@ abstract class MessageParserImpl<S extends Shareable>
 		boolean visible = meta.getBoolean(MSG_KEY_VISIBLE_IN_UI, false);
 		boolean available = meta.getBoolean(MSG_KEY_AVAILABLE_TO_ANSWER, false);
 		boolean accepted = meta.getBoolean(MSG_KEY_INVITATION_ACCEPTED, false);
+		long timer = meta.getLong(MSG_KEY_AUTO_DELETE_TIMER,
+				NO_AUTO_DELETE_TIMER);
 		return new MessageMetadata(type, shareableId, timestamp, local, read,
-				visible, available, accepted);
+				visible, available, accepted, timer);
 	}
 
 	@Override
@@ -90,8 +94,10 @@ abstract class MessageParserImpl<S extends Shareable>
 		BdfList descriptor = body.getList(2);
 		S shareable = createShareable(descriptor);
 		String text = body.getOptionalString(3);
+		long timer = NO_AUTO_DELETE_TIMER;
+		if (body.size() == 5) timer = body.getLong(4, NO_AUTO_DELETE_TIMER);
 		return new InviteMessage<>(m.getId(), previousMessageId,
-				m.getGroupId(), shareable, text, m.getTimestamp());
+				m.getGroupId(), shareable, text, m.getTimestamp(), timer);
 	}
 
 	@Override
@@ -100,8 +106,10 @@ abstract class MessageParserImpl<S extends Shareable>
 		GroupId shareableId = new GroupId(body.getRaw(1));
 		byte[] b = body.getOptionalRaw(2);
 		MessageId previousMessageId = (b == null ? null : new MessageId(b));
+		long timer = NO_AUTO_DELETE_TIMER;
+		if (body.size() == 4) timer = body.getLong(3, NO_AUTO_DELETE_TIMER);
 		return new AcceptMessage(m.getId(), previousMessageId, m.getGroupId(),
-				shareableId, m.getTimestamp());
+				shareableId, m.getTimestamp(), timer);
 	}
 
 	@Override
@@ -110,8 +118,10 @@ abstract class MessageParserImpl<S extends Shareable>
 		GroupId shareableId = new GroupId(body.getRaw(1));
 		byte[] b = body.getOptionalRaw(2);
 		MessageId previousMessageId = (b == null ? null : new MessageId(b));
+		long timer = NO_AUTO_DELETE_TIMER;
+		if (body.size() == 4) timer = body.getLong(3, NO_AUTO_DELETE_TIMER);
 		return new DeclineMessage(m.getId(), m.getGroupId(), shareableId,
-				m.getTimestamp(), previousMessageId);
+				m.getTimestamp(), previousMessageId, timer);
 	}
 
 	@Override

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

@@ -28,6 +28,7 @@ import java.util.Map;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 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;
@@ -57,14 +58,15 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 	private final MessageEncoder messageEncoder;
 	private final MessageTracker messageTracker;
 	private final Clock clock;
-	private final ClientId shareableClientId;
-	private final int shareableClientVersion;
+	private final ClientId sharingClientId, shareableClientId;
+	private final int sharingClientMajorVersion, shareableClientMajorVersion;
 
 	ProtocolEngineImpl(DatabaseComponent db, ClientHelper clientHelper,
 			ClientVersioningManager clientVersioningManager,
 			MessageEncoder messageEncoder, MessageParser<S> messageParser,
 			MessageTracker messageTracker, Clock clock,
-			ClientId shareableClientId, int shareableClientVersion) {
+			ClientId sharingClientId, int sharingClientMajorVersion,
+			ClientId shareableClientId, int shareableClientMajorVersion) {
 		this.db = db;
 		this.clientHelper = clientHelper;
 		this.clientVersioningManager = clientVersioningManager;
@@ -72,8 +74,10 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 		this.messageParser = messageParser;
 		this.messageTracker = messageTracker;
 		this.clock = clock;
+		this.sharingClientId = sharingClientId;
+		this.sharingClientMajorVersion = sharingClientMajorVersion;
 		this.shareableClientId = shareableClientId;
-		this.shareableClientVersion = shareableClientVersion;
+		this.shareableClientMajorVersion = shareableClientMajorVersion;
 	}
 
 	@Override
@@ -121,9 +125,21 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 			throw new DbException(e); // Invalid group descriptor
 		}
 		long localTimestamp = Math.max(timestamp, getLocalTimestamp(s));
-		Message m = messageEncoder.encodeInviteMessage(s.getContactGroupId(),
-				localTimestamp, s.getLastLocalMessageId(), descriptor, text);
-		sendMessage(txn, m, INVITE, s.getShareableId(), true);
+		Message m;
+		if (contactSupportsAutoDeletion(txn, s.getContactGroupId())) {
+			// TODO: Look up the current auto-delete timer
+			long timer = NO_AUTO_DELETE_TIMER;
+			m = messageEncoder.encodeInviteMessage(s.getContactGroupId(),
+					localTimestamp, s.getLastLocalMessageId(), descriptor,
+					text, timer);
+			sendMessage(txn, m, INVITE, s.getShareableId(), true, timer);
+		} else {
+			m = messageEncoder.encodeInviteMessage(s.getContactGroupId(),
+					localTimestamp, s.getLastLocalMessageId(), descriptor,
+					text);
+			sendMessage(txn, m, INVITE, s.getShareableId(), true,
+					NO_AUTO_DELETE_TIMER);
+		}
 		return m;
 	}
 
@@ -173,12 +189,23 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 	protected abstract void addShareable(Transaction txn, MessageId inviteId)
 			throws DbException, FormatException;
 
-	private Message sendAcceptMessage(Transaction txn, Session session)
+	private Message sendAcceptMessage(Transaction txn, Session s)
 			throws DbException {
-		Message m = messageEncoder.encodeAcceptMessage(
-				session.getContactGroupId(), session.getShareableId(),
-				getLocalTimestamp(session), session.getLastLocalMessageId());
-		sendMessage(txn, m, ACCEPT, session.getShareableId(), true);
+		Message m;
+		if (contactSupportsAutoDeletion(txn, s.getContactGroupId())) {
+			// TODO: Look up the current auto-delete timer
+			long timer = NO_AUTO_DELETE_TIMER;
+			m = messageEncoder.encodeAcceptMessage(s.getContactGroupId(),
+					s.getShareableId(), getLocalTimestamp(s),
+					s.getLastLocalMessageId(), timer);
+			sendMessage(txn, m, ACCEPT, s.getShareableId(), true, timer);
+		} else {
+			m = messageEncoder.encodeAcceptMessage(s.getContactGroupId(),
+					s.getShareableId(), getLocalTimestamp(s),
+					s.getLastLocalMessageId());
+			sendMessage(txn, m, ACCEPT, s.getShareableId(), true,
+					NO_AUTO_DELETE_TIMER);
+		}
 		return m;
 	}
 
@@ -215,12 +242,23 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 				s.getInviteTimestamp());
 	}
 
-	private Message sendDeclineMessage(Transaction txn, Session session)
+	private Message sendDeclineMessage(Transaction txn, Session s)
 			throws DbException {
-		Message m = messageEncoder.encodeDeclineMessage(
-				session.getContactGroupId(), session.getShareableId(),
-				getLocalTimestamp(session), session.getLastLocalMessageId());
-		sendMessage(txn, m, DECLINE, session.getShareableId(), true);
+		Message m;
+		if (contactSupportsAutoDeletion(txn, s.getContactGroupId())) {
+			// TODO: Look up the current auto-delete timer
+			long timer = NO_AUTO_DELETE_TIMER;
+			m = messageEncoder.encodeDeclineMessage(s.getContactGroupId(),
+					s.getShareableId(), getLocalTimestamp(s),
+					s.getLastLocalMessageId(), timer);
+			sendMessage(txn, m, DECLINE, s.getShareableId(), true, timer);
+		} else {
+			m = messageEncoder.encodeDeclineMessage(s.getContactGroupId(),
+					s.getShareableId(), getLocalTimestamp(s),
+					s.getLastLocalMessageId());
+			sendMessage(txn, m, DECLINE, s.getShareableId(), true,
+					NO_AUTO_DELETE_TIMER);
+		}
 		return m;
 	}
 
@@ -263,7 +301,8 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 		Message m = messageEncoder.encodeLeaveMessage(
 				session.getContactGroupId(), session.getShareableId(),
 				getLocalTimestamp(session), session.getLastLocalMessageId());
-		sendMessage(txn, m, LEAVE, session.getShareableId(), false);
+		sendMessage(txn, m, LEAVE, session.getShareableId(), false,
+				NO_AUTO_DELETE_TIMER);
 		return m;
 	}
 
@@ -547,26 +586,25 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 			throws DbException {
 		if (!db.containsGroup(txn, g)) return false;
 		Group group = db.getGroup(txn, g);
-		return group.getClientId().equals(getShareableClientId());
+		return group.getClientId().equals(shareableClientId);
 	}
 
-	protected abstract ClientId getShareableClientId();
-
 	private Message sendAbortMessage(Transaction txn, Session session)
 			throws DbException {
 		Message m = messageEncoder.encodeAbortMessage(
 				session.getContactGroupId(), session.getShareableId(),
 				getLocalTimestamp(session), session.getLastLocalMessageId());
-		sendMessage(txn, m, ABORT, session.getShareableId(), false);
+		sendMessage(txn, m, ABORT, session.getShareableId(), false,
+				NO_AUTO_DELETE_TIMER);
 		return m;
 	}
 
 	private void sendMessage(Transaction txn, Message m, MessageType type,
-			GroupId shareableId, boolean visibleInConversation)
-			throws DbException {
-		BdfDictionary meta = messageEncoder
-				.encodeMetadata(type, shareableId, m.getTimestamp(), true, true,
-						visibleInConversation, false, false);
+			GroupId shareableId, boolean visibleInConversation,
+			long autoDeleteTimer) throws DbException {
+		BdfDictionary meta = messageEncoder.encodeMetadata(type, shareableId,
+				m.getTimestamp(), true, true, visibleInConversation, false,
+				false, autoDeleteTimer);
 		try {
 			clientHelper.addLocalMessage(txn, m, meta, true, false);
 		} catch (FormatException e) {
@@ -612,7 +650,7 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 		// Apply min of preferred visibility and client's visibility
 		ContactId contactId = getContactId(txn, session.getContactGroupId());
 		Visibility client = clientVersioningManager.getClientVisibility(txn,
-				contactId, shareableClientId, shareableClientVersion);
+				contactId, shareableClientId, shareableClientMajorVersion);
 		Visibility min = Visibility.min(preferred, client);
 		db.setGroupVisibility(txn, contactId, session.getShareableId(), min);
 	}
@@ -637,4 +675,20 @@ abstract class ProtocolEngineImpl<S extends Shareable>
 						session.getInviteTimestamp()) + 1);
 	}
 
+	boolean contactSupportsAutoDeletion(Transaction txn, GroupId contactGroupId)
+			throws DbException {
+		try {
+			BdfDictionary meta = clientHelper
+					.getGroupMetadataAsDictionary(txn, contactGroupId);
+			int contactId = meta.getLong(GROUP_KEY_CONTACT_ID).intValue();
+			ContactId c = new ContactId(contactId);
+			int minorVersion = clientVersioningManager
+					.getClientMinorVersion(txn, c, sharingClientId,
+							sharingClientMajorVersion);
+			// Auto-delete was added in client version 0.1
+			return minorVersion >= 1;
+		} catch (FormatException e) {
+			throw new DbException(e);
+		}
+	}
 }

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

@@ -16,6 +16,7 @@ interface SharingConstants {
 	String MSG_KEY_VISIBLE_IN_UI = "visibleInUi";
 	String MSG_KEY_AVAILABLE_TO_ANSWER = "availableToAnswer";
 	String MSG_KEY_INVITATION_ACCEPTED = "invitationAccepted";
+	String MSG_KEY_AUTO_DELETE_TIMER = "autoDeleteTimer";
 
 	// Session keys
 	String SESSION_KEY_IS_SESSION = "isSession";

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

@@ -368,7 +368,8 @@ abstract class SharingManagerImpl<S extends Shareable>
 		return invitationFactory
 				.createInvitationRequest(meta.isLocal(), status.isSent(),
 						status.isSeen(), meta.isRead(), invite, c,
-						meta.isAvailableToAnswer(), canBeOpened);
+						meta.isAvailableToAnswer(), canBeOpened,
+						meta.getAutoDeleteTimer());
 	}
 
 	private InvitationResponse parseInvitationResponse(GroupId contactGroupId,
@@ -376,7 +377,8 @@ abstract class SharingManagerImpl<S extends Shareable>
 			boolean accept) {
 		return invitationFactory.createInvitationResponse(m, contactGroupId,
 				meta.getTimestamp(), meta.isLocal(), status.isSent(),
-				status.isSeen(), meta.isRead(), accept, meta.getShareableId());
+				status.isSeen(), meta.isRead(), accept, meta.getShareableId(),
+				meta.getAutoDeleteTimer());
 	}
 
 	@Override

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

@@ -15,11 +15,15 @@ import org.briarproject.bramble.api.sync.Message;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.bramble.api.system.Clock;
 
-import java.util.Collections;
-
+import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
 
+import static java.util.Collections.singletonList;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.MAX_AUTO_DELETE_TIMER_MS;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.MIN_AUTO_DELETE_TIMER_MS;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 import static org.briarproject.bramble.util.ValidationUtils.checkLength;
+import static org.briarproject.bramble.util.ValidationUtils.checkRange;
 import static org.briarproject.bramble.util.ValidationUtils.checkSize;
 import static org.briarproject.briar.api.sharing.SharingConstants.MAX_INVITATION_TEXT_LENGTH;
 import static org.briarproject.briar.sharing.MessageType.INVITE;
@@ -45,9 +49,10 @@ abstract class SharingValidator extends BdfMessageValidator {
 				return validateInviteMessage(m, body);
 			case ACCEPT:
 			case DECLINE:
+				return validateNonInviteMessageWithOptionalTimer(type, m, body);
 			case LEAVE:
 			case ABORT:
-				return validateNonInviteMessage(type, m, body);
+				return validateNonInviteMessageWithoutTimer(type, m, body);
 			default:
 				throw new FormatException();
 		}
@@ -55,47 +60,80 @@ abstract class SharingValidator extends BdfMessageValidator {
 
 	private BdfMessageContext validateInviteMessage(Message m, BdfList body)
 			throws FormatException {
-		checkSize(body, 4);
+		// Client version 0.0: Message type, optional previous message ID,
+		// descriptor, optional text.
+		// Client version 0.1: Message type, optional previous message ID,
+		// descriptor, optional text, optional auto-delete timer.
+		checkSize(body, 4, 5);
 		byte[] previousMessageId = body.getOptionalRaw(1);
 		checkLength(previousMessageId, UniqueId.LENGTH);
 		BdfList descriptor = body.getList(2);
 		GroupId shareableId = validateDescriptor(descriptor);
 		String text = body.getOptionalString(3);
 		checkLength(text, 1, MAX_INVITATION_TEXT_LENGTH);
+		long timer = NO_AUTO_DELETE_TIMER;
+		if (body.size() == 5) timer = validateTimer(body.getOptionalLong(4));
 
-		BdfDictionary meta = messageEncoder
-				.encodeMetadata(INVITE, shareableId, m.getTimestamp(), false,
-						false, false, false, false);
+		BdfDictionary meta = messageEncoder.encodeMetadata(INVITE, shareableId,
+				m.getTimestamp(), false, false, false, false, false, timer);
 		if (previousMessageId == null) {
 			return new BdfMessageContext(meta);
 		} else {
 			MessageId dependency = new MessageId(previousMessageId);
-			return new BdfMessageContext(meta,
-					Collections.singletonList(dependency));
+			return new BdfMessageContext(meta, singletonList(dependency));
 		}
 	}
 
 	protected abstract GroupId validateDescriptor(BdfList descriptor)
 			throws FormatException;
 
-	private BdfMessageContext validateNonInviteMessage(MessageType type,
-			Message m, BdfList body) throws FormatException {
+	private BdfMessageContext validateNonInviteMessageWithoutTimer(
+			MessageType type, Message m, BdfList body) throws FormatException {
 		checkSize(body, 3);
 		byte[] shareableId = body.getRaw(1);
 		checkLength(shareableId, UniqueId.LENGTH);
 		byte[] previousMessageId = body.getOptionalRaw(2);
 		checkLength(previousMessageId, UniqueId.LENGTH);
 
-		BdfDictionary meta = messageEncoder
-				.encodeMetadata(type, new GroupId(shareableId),
-						m.getTimestamp(), false, false, false, false, false);
+		BdfDictionary meta = messageEncoder.encodeMetadata(type,
+				new GroupId(shareableId), m.getTimestamp(), false, false,
+				false, false, false, NO_AUTO_DELETE_TIMER);
 		if (previousMessageId == null) {
 			return new BdfMessageContext(meta);
 		} else {
 			MessageId dependency = new MessageId(previousMessageId);
-			return new BdfMessageContext(meta,
-					Collections.singletonList(dependency));
+			return new BdfMessageContext(meta, singletonList(dependency));
 		}
 	}
 
+	private BdfMessageContext validateNonInviteMessageWithOptionalTimer(
+			MessageType type, Message m, BdfList body) throws FormatException {
+		// Client version 0.0: Message type, shareable ID, optional previous
+		// message ID.
+		// Client version 0.1: Message type, shareable ID, optional previous
+		// message ID, optional auto-delete timer.
+		checkSize(body, 3, 4);
+		byte[] shareableId = body.getRaw(1);
+		checkLength(shareableId, UniqueId.LENGTH);
+		byte[] previousMessageId = body.getOptionalRaw(2);
+		checkLength(previousMessageId, UniqueId.LENGTH);
+		long timer = NO_AUTO_DELETE_TIMER;
+		if (body.size() == 4) timer = validateTimer(body.getOptionalLong(3));
+
+		BdfDictionary meta = messageEncoder.encodeMetadata(type,
+				new GroupId(shareableId), m.getTimestamp(), false, false,
+				false, false, false, timer);
+		if (previousMessageId == null) {
+			return new BdfMessageContext(meta);
+		} else {
+			MessageId dependency = new MessageId(previousMessageId);
+			return new BdfMessageContext(meta, singletonList(dependency));
+		}
+	}
+
+	private long validateTimer(@Nullable Long timer) throws FormatException {
+		if (timer == null) return NO_AUTO_DELETE_TIMER;
+		checkRange(timer, MIN_AUTO_DELETE_TIMER_MS, MAX_AUTO_DELETE_TIMER_MS);
+		return timer;
+	}
 }

briar-core/src/test/java/org/briarproject/briar/sharing/BlogSharingValidatorTest.java

@@ -8,10 +8,16 @@ import org.briarproject.briar.api.blog.Blog;
 import org.jmock.Expectations;
 import org.junit.Test;
 
+import javax.annotation.Nullable;
+
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.MAX_AUTO_DELETE_TIMER_MS;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.MIN_AUTO_DELETE_TIMER_MS;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 import static org.briarproject.bramble.test.TestUtils.getAuthor;
 import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.briarproject.briar.api.sharing.SharingConstants.MAX_INVITATION_TEXT_LENGTH;
 import static org.briarproject.briar.sharing.MessageType.INVITE;
+import static org.junit.Assert.fail;
 
 public class BlogSharingValidatorTest extends SharingValidatorTest {
 
@@ -31,7 +37,7 @@ public class BlogSharingValidatorTest extends SharingValidatorTest {
 	@Test
 	public void testAcceptsInvitationWithText() throws Exception {
 		expectCreateBlog();
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), previousMsgId, descriptor, text));
 		assertExpectedContext(context, previousMsgId);
@@ -40,7 +46,7 @@ public class BlogSharingValidatorTest extends SharingValidatorTest {
 	@Test
 	public void testAcceptsInvitationWithNullText() throws Exception {
 		expectCreateBlog();
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), previousMsgId, descriptor, null));
 		assertExpectedContext(context, previousMsgId);
@@ -49,16 +55,64 @@ public class BlogSharingValidatorTest extends SharingValidatorTest {
 	@Test
 	public void testAcceptsInvitationWithNullPreviousMsgId() throws Exception {
 		expectCreateBlog();
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), null, descriptor, text));
 		assertExpectedContext(context, null);
 	}
 
+	@Test
+	public void testAcceptsInvitationWithMinAutoDeleteTimer() throws Exception {
+		testAcceptsInvitationWithAutoDeleteTimer(MIN_AUTO_DELETE_TIMER_MS);
+	}
+
+	@Test
+	public void testAcceptsInvitationWithMaxAutoDeleteTimer() throws Exception {
+		testAcceptsInvitationWithAutoDeleteTimer(MAX_AUTO_DELETE_TIMER_MS);
+	}
+
+	@Test
+	public void testAcceptsInvitationWithNullAutoDeleteTimer()
+			throws Exception {
+		testAcceptsInvitationWithAutoDeleteTimer(null);
+	}
+
+	private void testAcceptsInvitationWithAutoDeleteTimer(@Nullable Long timer)
+			throws Exception {
+		expectCreateBlog();
+		expectEncodeMetadata(INVITE,
+				timer == null ? NO_AUTO_DELETE_TIMER : timer);
+		BdfMessageContext context = validator.validateMessage(message, group,
+				BdfList.of(INVITE.getValue(), previousMsgId, descriptor, text,
+						timer));
+		assertExpectedContext(context, previousMsgId);
+	}
+
+	@Test(expected = FormatException.class)
+	public void testRejectsInvitationWithTooBigAutoDeleteTimer()
+			throws Exception {
+		testRejectsInvitationWithAutoDeleteTimer(MAX_AUTO_DELETE_TIMER_MS + 1);
+	}
+
+	@Test(expected = FormatException.class)
+	public void testRejectsInvitationWithTooSmallAutoDeleteTimer()
+			throws Exception {
+		testRejectsInvitationWithAutoDeleteTimer(MIN_AUTO_DELETE_TIMER_MS - 1);
+	}
+
+	private void testRejectsInvitationWithAutoDeleteTimer(Long timer)
+			throws Exception {
+		expectCreateBlog();
+		validator.validateMessage(message, group,
+				BdfList.of(INVITE.getValue(), previousMsgId, descriptor, text,
+						timer));
+		fail();
+	}
+
 	@Test
 	public void testAcceptsInvitationForRssBlog() throws Exception {
 		expectCreateRssBlog();
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfList rssDescriptor = BdfList.of(authorList, true);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), previousMsgId, rssDescriptor,
@@ -93,7 +147,7 @@ public class BlogSharingValidatorTest extends SharingValidatorTest {
 	public void testAcceptsMinLengthText() throws Exception {
 		String shortText = getRandomString(1);
 		expectCreateBlog();
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), previousMsgId, descriptor,
 						shortText));

briar-core/src/test/java/org/briarproject/briar/sharing/ForumSharingValidatorTest.java

@@ -7,12 +7,18 @@ import org.briarproject.briar.api.forum.Forum;
 import org.jmock.Expectations;
 import org.junit.Test;
 
+import javax.annotation.Nullable;
+
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.MAX_AUTO_DELETE_TIMER_MS;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.MIN_AUTO_DELETE_TIMER_MS;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
 import static org.briarproject.bramble.util.StringUtils.getRandomString;
 import static org.briarproject.briar.api.forum.ForumConstants.FORUM_SALT_LENGTH;
 import static org.briarproject.briar.api.forum.ForumConstants.MAX_FORUM_NAME_LENGTH;
 import static org.briarproject.briar.api.sharing.SharingConstants.MAX_INVITATION_TEXT_LENGTH;
 import static org.briarproject.briar.sharing.MessageType.INVITE;
+import static org.junit.Assert.fail;
 
 public class ForumSharingValidatorTest extends SharingValidatorTest {
 
@@ -31,7 +37,7 @@ public class ForumSharingValidatorTest extends SharingValidatorTest {
 	@Test
 	public void testAcceptsInvitationWithText() throws Exception {
 		expectCreateForum(forumName);
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), previousMsgId, descriptor, text));
 		assertExpectedContext(context, previousMsgId);
@@ -40,7 +46,7 @@ public class ForumSharingValidatorTest extends SharingValidatorTest {
 	@Test
 	public void testAcceptsInvitationWithNullText() throws Exception {
 		expectCreateForum(forumName);
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), previousMsgId, descriptor, null));
 		assertExpectedContext(context, previousMsgId);
@@ -49,12 +55,60 @@ public class ForumSharingValidatorTest extends SharingValidatorTest {
 	@Test
 	public void testAcceptsInvitationWithNullPreviousMsgId() throws Exception {
 		expectCreateForum(forumName);
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), null, descriptor, null));
 		assertExpectedContext(context, null);
 	}
 
+	@Test
+	public void testAcceptsInvitationWithMinAutoDeleteTimer() throws Exception {
+		testAcceptsInvitationWithAutoDeleteTimer(MIN_AUTO_DELETE_TIMER_MS);
+	}
+
+	@Test
+	public void testAcceptsInvitationWithMaxAutoDeleteTimer() throws Exception {
+		testAcceptsInvitationWithAutoDeleteTimer(MAX_AUTO_DELETE_TIMER_MS);
+	}
+
+	@Test
+	public void testAcceptsInvitationWithNullAutoDeleteTimer()
+			throws Exception {
+		testAcceptsInvitationWithAutoDeleteTimer(null);
+	}
+
+	private void testAcceptsInvitationWithAutoDeleteTimer(@Nullable Long timer)
+			throws Exception {
+		expectCreateForum(forumName);
+		expectEncodeMetadata(INVITE,
+				timer == null ? NO_AUTO_DELETE_TIMER : timer);
+		BdfMessageContext context = validator.validateMessage(message, group,
+				BdfList.of(INVITE.getValue(), previousMsgId, descriptor, text,
+						timer));
+		assertExpectedContext(context, previousMsgId);
+	}
+
+	@Test(expected = FormatException.class)
+	public void testRejectsInvitationWithTooBigAutoDeleteTimer()
+			throws Exception {
+		testRejectsInvitationWithAutoDeleteTimer(MAX_AUTO_DELETE_TIMER_MS + 1);
+	}
+
+	@Test(expected = FormatException.class)
+	public void testRejectsInvitationWithTooSmallAutoDeleteTimer()
+			throws Exception {
+		testRejectsInvitationWithAutoDeleteTimer(MIN_AUTO_DELETE_TIMER_MS - 1);
+	}
+
+	private void testRejectsInvitationWithAutoDeleteTimer(long timer)
+			throws FormatException {
+		expectCreateForum(forumName);
+		validator.validateMessage(message, group,
+				BdfList.of(INVITE.getValue(), previousMsgId, descriptor, text,
+						timer));
+		fail();
+	}
+
 	@Test(expected = FormatException.class)
 	public void testRejectsNullForumName() throws Exception {
 		BdfList invalidDescriptor = BdfList.of(null, salt);
@@ -84,7 +138,7 @@ public class ForumSharingValidatorTest extends SharingValidatorTest {
 		String shortForumName = getRandomString(1);
 		BdfList validDescriptor = BdfList.of(shortForumName, salt);
 		expectCreateForum(shortForumName);
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), previousMsgId, validDescriptor,
 						null));
@@ -144,7 +198,7 @@ public class ForumSharingValidatorTest extends SharingValidatorTest {
 	@Test
 	public void testAcceptsMinLengthText() throws Exception {
 		expectCreateForum(forumName);
-		expectEncodeMetadata(INVITE);
+		expectEncodeMetadata(INVITE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(INVITE.getValue(), previousMsgId, descriptor, "1"));
 		assertExpectedContext(context, previousMsgId);

briar-core/src/test/java/org/briarproject/briar/sharing/SharingValidatorTest.java

@@ -16,6 +16,11 @@ import java.util.Collection;
 
 import javax.annotation.Nullable;
 
+import static java.util.Collections.emptyList;
+import static java.util.Collections.singletonList;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.MAX_AUTO_DELETE_TIMER_MS;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.MIN_AUTO_DELETE_TIMER_MS;
+import static org.briarproject.bramble.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
 import static org.briarproject.bramble.test.TestUtils.getRandomBytes;
 import static org.briarproject.bramble.test.TestUtils.getRandomId;
 import static org.briarproject.briar.sharing.MessageType.ABORT;
@@ -24,7 +29,7 @@ import static org.briarproject.briar.sharing.MessageType.DECLINE;
 import static org.briarproject.briar.sharing.MessageType.INVITE;
 import static org.briarproject.briar.sharing.MessageType.LEAVE;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 public abstract class SharingValidatorTest extends ValidatorTestCase {
 
@@ -54,23 +59,84 @@ public abstract class SharingValidatorTest extends ValidatorTestCase {
 
 	@Test
 	public void testAcceptsAccept() throws Exception {
-		expectEncodeMetadata(ACCEPT);
+		expectEncodeMetadata(ACCEPT, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(ACCEPT.getValue(), groupId, previousMsgId));
 		assertExpectedContext(context, previousMsgId);
 	}
 
+	@Test
+	public void testAcceptsAcceptWithMinAutoDeleteTimer() throws Exception {
+		testAcceptsResponseWithAutoDeleteTimer(ACCEPT,
+				MIN_AUTO_DELETE_TIMER_MS);
+	}
+
+	@Test
+	public void testAcceptsAcceptWithMaxAutoDeleteTimer() throws Exception {
+		testAcceptsResponseWithAutoDeleteTimer(ACCEPT,
+				MAX_AUTO_DELETE_TIMER_MS);
+	}
+
+	@Test
+	public void testAcceptsAcceptWithNullAutoDeleteTimer() throws Exception {
+		testAcceptsResponseWithAutoDeleteTimer(ACCEPT, null);
+	}
+
+	@Test(expected = FormatException.class)
+	public void testRejectsAcceptWithTooBigAutoDeleteTimer() throws Exception {
+		testRejectsResponseWithAutoDeleteTimer(ACCEPT,
+				MAX_AUTO_DELETE_TIMER_MS + 1);
+	}
+
+	@Test(expected = FormatException.class)
+	public void testRejectsAcceptWithTooSmallAutoDeleteTimer()
+			throws Exception {
+		testRejectsResponseWithAutoDeleteTimer(ACCEPT,
+				MIN_AUTO_DELETE_TIMER_MS - 1);
+	}
+
 	@Test
 	public void testAcceptsDecline() throws Exception {
-		expectEncodeMetadata(DECLINE);
+		expectEncodeMetadata(DECLINE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(DECLINE.getValue(), groupId, previousMsgId));
 		assertExpectedContext(context, previousMsgId);
 	}
 
+	@Test
+	public void testAcceptsDeclineWithMinAutoDeleteTimer() throws Exception {
+		testAcceptsResponseWithAutoDeleteTimer(DECLINE,
+				MIN_AUTO_DELETE_TIMER_MS);
+	}
+
+	@Test
+	public void testAcceptsDeclineWithMaxAutoDeleteTimer() throws Exception {
+		testAcceptsResponseWithAutoDeleteTimer(DECLINE,
+				MAX_AUTO_DELETE_TIMER_MS);
+	}
+
+	@Test
+	public void testAcceptsDeclineWithNullAutoDeleteTimer() throws Exception {
+		testAcceptsResponseWithAutoDeleteTimer(DECLINE, null);
+	}
+
+	@Test(expected = FormatException.class)
+	public void testRejectsDeclineWithTooBigAutoDeleteTimer()
+			throws Exception {
+		testRejectsResponseWithAutoDeleteTimer(DECLINE,
+				MAX_AUTO_DELETE_TIMER_MS + 1);
+	}
+
+	@Test(expected = FormatException.class)
+	public void testRejectsDeclineWithTooSmallAutoDeleteTimer()
+			throws Exception {
+		testRejectsResponseWithAutoDeleteTimer(DECLINE,
+				MIN_AUTO_DELETE_TIMER_MS - 1);
+	}
+
 	@Test
 	public void testAcceptsLeave() throws Exception {
-		expectEncodeMetadata(LEAVE);
+		expectEncodeMetadata(LEAVE, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(LEAVE.getValue(), groupId, previousMsgId));
 		assertExpectedContext(context, previousMsgId);
@@ -78,7 +144,7 @@ public abstract class SharingValidatorTest extends ValidatorTestCase {
 
 	@Test
 	public void testAcceptsAbort() throws Exception {
-		expectEncodeMetadata(ABORT);
+		expectEncodeMetadata(ABORT, NO_AUTO_DELETE_TIMER);
 		BdfMessageContext context = validator.validateMessage(message, group,
 				BdfList.of(ABORT.getValue(), groupId, previousMsgId));
 		assertExpectedContext(context, previousMsgId);
@@ -141,10 +207,10 @@ public abstract class SharingValidatorTest extends ValidatorTestCase {
 				BdfList.of(ABORT.getValue(), groupId, previousMsgId, 123));
 	}
 
-	void expectEncodeMetadata(MessageType type) {
+	void expectEncodeMetadata(MessageType type, long autoDeleteTimer) {
 		context.checking(new Expectations() {{
 			oneOf(messageEncoder).encodeMetadata(type, groupId, timestamp,
-					false, false, false, false, false);
+					false, false, false, false, false, autoDeleteTimer);
 			will(returnValue(meta));
 		}});
 	}
@@ -153,12 +219,26 @@ public abstract class SharingValidatorTest extends ValidatorTestCase {
 			@Nullable MessageId previousMsgId) {
 		Collection<MessageId> dependencies = messageContext.getDependencies();
 		if (previousMsgId == null) {
-			assertTrue(dependencies.isEmpty());
+			assertEquals(emptyList(), dependencies);
 		} else {
-			assertEquals(1, dependencies.size());
-			assertTrue(dependencies.contains(previousMsgId));
+			assertEquals(singletonList(previousMsgId), dependencies);
 		}
 		assertEquals(meta, messageContext.getDictionary());
 	}
 
+	private void testAcceptsResponseWithAutoDeleteTimer(MessageType type,
+			@Nullable Long timer) throws Exception {
+		expectEncodeMetadata(type,
+				timer == null ? NO_AUTO_DELETE_TIMER : timer);
+		BdfMessageContext context = validator.validateMessage(message, group,
+				BdfList.of(type.getValue(), groupId, previousMsgId, timer));
+		assertExpectedContext(context, previousMsgId);
+	}
+
+	private void testRejectsResponseWithAutoDeleteTimer(MessageType type,
+			long timer) throws FormatException {
+		validator.validateMessage(message, group,
+				BdfList.of(type.getValue(), groupId, previousMsgId, timer));
+		fail();
+	}
 }