Merge tag 'release-1.3.6' into briar-as-subproject

release-1.3.6

briar-api/build.gradle

@@ -10,4 +10,7 @@ dependencies {
 	implementation project(path: ':briar:bramble-api', configuration: 'default')
 
 	signature 'org.codehaus.mojo.signature:java16:1.1@signature'
+
+	testImplementation project(path: ':bramble-api', configuration: 'testOutput')
+	testImplementation "junit:junit:$junit_version"
 }

briar-api/src/main/java/org/briarproject/briar/api/attachment/Attachment.java

@@ -1,4 +1,4 @@
-package org.briarproject.briar.api.messaging;
+package org.briarproject.briar.api.attachment;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 

briar-api/src/main/java/org/briarproject/briar/api/attachment/AttachmentHeader.java

@@ -1,6 +1,7 @@
-package org.briarproject.briar.api.messaging;
+package org.briarproject.briar.api.attachment;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 
 import javax.annotation.concurrent.Immutable;
@@ -9,14 +10,21 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class AttachmentHeader {
 
+	private final GroupId groupId;
 	private final MessageId messageId;
 	private final String contentType;
 
-	public AttachmentHeader(MessageId messageId, String contentType) {
+	public AttachmentHeader(GroupId groupId, MessageId messageId,
+			String contentType) {
+		this.groupId = groupId;
 		this.messageId = messageId;
 		this.contentType = contentType;
 	}
 
+	public GroupId getGroupId() {
+		return groupId;
+	}
+
 	public MessageId getMessageId() {
 		return messageId;
 	}
@@ -27,13 +35,15 @@ public class AttachmentHeader {
 
 	@Override
 	public boolean equals(Object o) {
-		return o instanceof AttachmentHeader &&
-				messageId.equals(((AttachmentHeader) o).messageId);
+		if (o instanceof AttachmentHeader) {
+			AttachmentHeader h = (AttachmentHeader) o;
+			return groupId.equals(h.groupId) && messageId.equals(h.messageId);
+		}
+		return false;
 	}
 
 	@Override
 	public int hashCode() {
 		return messageId.hashCode();
 	}
-
 }

briar-api/src/main/java/org/briarproject/briar/api/attachment/AttachmentReader.java

@@ -0,0 +1,20 @@
+package org.briarproject.briar.api.attachment;
+
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.NoSuchMessageException;
+
+public interface AttachmentReader {
+
+	/**
+	 * Returns the attachment with the given attachment header.
+	 *
+	 * @throws NoSuchMessageException If the header refers to a message in
+	 * a different group from the one specified in the header, to a message
+	 * that is not an attachment, or to an attachment that does not have the
+	 * expected content type. This is meant to prevent social engineering
+	 * attacks that use invalid attachment IDs to test whether messages exist
+	 * in the victim's database
+	 */
+	Attachment getAttachment(AttachmentHeader h) throws DbException;
+
+}

briar-api/src/main/java/org/briarproject/briar/api/attachment/FileTooBigException.java

@@ -1,4 +1,4 @@
-package org.briarproject.briar.api.messaging;
+package org.briarproject.briar.api.attachment;
 
 import java.io.IOException;
 

briar-api/src/main/java/org/briarproject/briar/api/attachment/MediaConstants.java

@@ -0,0 +1,21 @@
+package org.briarproject.briar.api.attachment;
+
+import static org.briarproject.bramble.api.sync.SyncConstants.MAX_MESSAGE_BODY_LENGTH;
+
+public interface MediaConstants {
+
+	// Metadata keys for messages
+	String MSG_KEY_CONTENT_TYPE = "contentType";
+	String MSG_KEY_DESCRIPTOR_LENGTH = "descriptorLength";
+
+	/**
+	 * The maximum length of an attachment's content type in UTF-8 bytes.
+	 */
+	int MAX_CONTENT_TYPE_BYTES = 80;
+
+	/**
+	 * The maximum allowed size of image attachments.
+	 * TODO: Different limit for GIFs?
+	 */
+	int MAX_IMAGE_SIZE = MAX_MESSAGE_BODY_LENGTH - 100; // 6 * 1024 * 1024;
+}

briar-api/src/main/java/org/briarproject/briar/api/autodelete/AutoDeleteConstants.java

@@ -0,0 +1,23 @@
+package org.briarproject.briar.api.autodelete;
+
+import static java.util.concurrent.TimeUnit.DAYS;
+import static java.util.concurrent.TimeUnit.MINUTES;
+
+public interface AutoDeleteConstants {
+
+	/**
+	 * The minimum valid auto-delete timer duration in milliseconds.
+	 */
+	long MIN_AUTO_DELETE_TIMER_MS = MINUTES.toMillis(1);
+
+	/**
+	 * The maximum valid auto-delete timer duration in milliseconds.
+	 */
+	long MAX_AUTO_DELETE_TIMER_MS = DAYS.toMillis(365);
+
+	/**
+	 * Placeholder value indicating that a message has no auto-delete timer.
+	 * This value should not be sent over the wire - send null instead.
+	 */
+	long NO_AUTO_DELETE_TIMER = -1;
+}

briar-api/src/main/java/org/briarproject/briar/api/autodelete/AutoDeleteManager.java

@@ -0,0 +1,64 @@
+package org.briarproject.briar.api.autodelete;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.ClientId;
+
+import static java.util.concurrent.TimeUnit.DAYS;
+
+@NotNullByDefault
+public interface AutoDeleteManager {
+
+	/**
+	 * The unique ID of the auto-delete client.
+	 */
+	ClientId CLIENT_ID = new ClientId("org.briarproject.briar.autodelete");
+
+	/**
+	 * The current major version of the auto-delete client.
+	 */
+	int MAJOR_VERSION = 0;
+
+	/**
+	 * The current minor version of the auto-delete client.
+	 */
+	int MINOR_VERSION = 0;
+
+	/**
+	 * The default auto-delete timer duration.
+	 */
+	long DEFAULT_TIMER_DURATION = DAYS.toMillis(7);
+
+	/**
+	 * Returns the auto-delete timer duration for the given contact. Use
+	 * {@link #getAutoDeleteTimer(Transaction, ContactId, long)} if the timer
+	 * will be used in an outgoing message.
+	 */
+	long getAutoDeleteTimer(Transaction txn, ContactId c) throws DbException;
+
+	/**
+	 * Returns the auto-delete timer duration for the given contact, for use in
+	 * a message with the given timestamp. The timestamp is stored. This method
+	 * requires a read-write transaction.
+	 */
+	long getAutoDeleteTimer(Transaction txn, ContactId c, long timestamp)
+			throws DbException;
+
+	/**
+	 * Sets the auto-delete timer duration for the given contact.
+	 */
+	void setAutoDeleteTimer(Transaction txn, ContactId c, long timer)
+			throws DbException;
+
+	/**
+	 * Receives an auto-delete timer duration from the given contact, carried
+	 * in a message with the given timestamp. The local timer is set to the
+	 * same duration unless it has been
+	 * {@link #setAutoDeleteTimer(Transaction, ContactId, long) changed} more
+	 * recently than the remote timer.
+	 */
+	void receiveAutoDeleteTimer(Transaction txn, ContactId c, long timer,
+			long timestamp) throws DbException;
+}

briar-api/src/main/java/org/briarproject/briar/api/autodelete/UnexpectedTimerException.java

@@ -0,0 +1,12 @@
+package org.briarproject.briar.api.autodelete;
+
+import org.briarproject.bramble.api.db.DbException;
+
+/**
+ * Thrown when a database operation is attempted as part of message storing
+ * and the operation is expecting a different timer state. This
+ * exception may occur due to concurrent updates and does not indicate a
+ * database error.
+ */
+public class UnexpectedTimerException extends DbException {
+}

briar-api/src/main/java/org/briarproject/briar/api/autodelete/event/AutoDeleteTimerMirroredEvent.java

@@ -0,0 +1,28 @@
+package org.briarproject.briar.api.autodelete.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class AutoDeleteTimerMirroredEvent extends Event {
+
+	private final ContactId contactId;
+	private final long newTimer;
+
+	public AutoDeleteTimerMirroredEvent(ContactId contactId, long newTimer) {
+		this.contactId = contactId;
+		this.newTimer = newTimer;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	public long getNewTimer() {
+		return newTimer;
+	}
+}

briar-api/src/main/java/org/briarproject/briar/api/autodelete/event/ConversationMessagesDeletedEvent.java

@@ -0,0 +1,36 @@
+package org.briarproject.briar.api.autodelete.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.MessageId;
+
+import java.util.Collection;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when one or more messages
+ * in the private conversation with a contact have been deleted.
+ */
+@Immutable
+@NotNullByDefault
+public class ConversationMessagesDeletedEvent extends Event {
+
+	private final ContactId contactId;
+	private final Collection<MessageId> messageIds;
+
+	public ConversationMessagesDeletedEvent(ContactId contactId,
+			Collection<MessageId> messageIds) {
+		this.contactId = contactId;
+		this.messageIds = messageIds;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	public Collection<MessageId> getMessageIds() {
+		return messageIds;
+	}
+}

briar-api/src/main/java/org/briarproject/briar/api/avatar/AvatarManager.java

@@ -0,0 +1,53 @@
+package org.briarproject.briar.api.avatar;
+
+import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.sync.ClientId;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.annotation.Nullable;
+
+@NotNullByDefault
+public interface AvatarManager {
+
+	/**
+	 * The unique ID of the avatar client.
+	 */
+	ClientId CLIENT_ID = new ClientId("org.briarproject.briar.avatar");
+
+	/**
+	 * The current major version of the avatar client.
+	 */
+	int MAJOR_VERSION = 0;
+
+	/**
+	 * The current minor version of the avatar client.
+	 */
+	int MINOR_VERSION = 0;
+
+	/**
+	 * Store a new profile image represented by the given InputStream
+	 * and share it with all contacts.
+	 */
+	AttachmentHeader addAvatar(String contentType, InputStream in)
+			throws DbException, IOException;
+
+	/**
+	 * Returns the current known profile image header for the given contact
+	 * or null if none is known.
+	 */
+	@Nullable
+	AttachmentHeader getAvatarHeader(Transaction txn, Contact c)
+			throws DbException;
+
+	/**
+	 * Returns our current profile image header or null if none has been added.
+	 */
+	@Nullable
+	AttachmentHeader getMyAvatarHeader(Transaction txn) throws DbException;
+}

briar-api/src/main/java/org/briarproject/briar/api/avatar/AvatarMessageEncoder.java

@@ -0,0 +1,18 @@
+package org.briarproject.briar.api.avatar;
+
+import org.briarproject.bramble.api.Pair;
+import org.briarproject.bramble.api.data.BdfDictionary;
+import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.sync.Message;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+public interface AvatarMessageEncoder {
+	/**
+	 * Returns an update message and its metadata.
+	 */
+	Pair<Message, BdfDictionary> encodeUpdateMessage(GroupId groupId,
+			long version, String contentType, InputStream in)
+			throws IOException;
+}

briar-api/src/main/java/org/briarproject/briar/api/avatar/event/AvatarUpdatedEvent.java

@@ -0,0 +1,33 @@
+package org.briarproject.briar.api.avatar.event;
+
+import org.briarproject.bramble.api.contact.ContactId;
+import org.briarproject.bramble.api.event.Event;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
+
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * An event that is broadcast when a new avatar is received.
+ */
+@Immutable
+@NotNullByDefault
+public class AvatarUpdatedEvent extends Event {
+
+	private final ContactId contactId;
+	private final AttachmentHeader attachmentHeader;
+
+	public AvatarUpdatedEvent(ContactId contactId,
+			AttachmentHeader attachmentHeader) {
+		this.contactId = contactId;
+		this.attachmentHeader = attachmentHeader;
+	}
+
+	public ContactId getContactId() {
+		return contactId;
+	}
+
+	public AttachmentHeader getAttachmentHeader() {
+		return attachmentHeader;
+	}
+}

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

@@ -1,7 +1,7 @@
 package org.briarproject.briar.api.blog;
 
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorInfo;
+import org.briarproject.briar.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;

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, boolean isAutoDecline) {
 		super(id, groupId, time, local, read, sent, seen, sessionId,
-				accept, shareableId);
+				accept, shareableId, autoDeleteTimer, isAutoDecline);
 	}
 
 	@Override

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

@@ -10,6 +10,7 @@ import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 
 import java.util.Collection;
+import java.util.List;
 
 import javax.annotation.Nullable;
 
@@ -98,21 +99,38 @@ public interface BlogManager {
 	 */
 	Collection<Blog> getBlogs() throws DbException;
 
+	/**
+	 * Returns the group IDs of all blogs to which the user subscribes.
+	 */
+	Collection<GroupId> getBlogIds(Transaction txn) throws DbException;
+
 	/**
 	 * Returns the header of the blog post with the given ID.
 	 */
-	BlogPostHeader getPostHeader(GroupId g, MessageId m) throws DbException;
+	BlogPostHeader getPostHeader(Transaction txn, GroupId g, MessageId m)
+			throws DbException;
 
 	/**
 	 * Returns the text of the blog post with the given ID.
 	 */
 	String getPostText(MessageId m) throws DbException;
 
+	/**
+	 * Returns the text of the blog post with the given ID.
+	 */
+	String getPostText(Transaction txn, MessageId m) throws DbException;
+
 	/**
 	 * Returns the headers of all posts in the given blog.
 	 */
 	Collection<BlogPostHeader> getPostHeaders(GroupId g) throws DbException;
 
+	/**
+	 * Returns the headers of all posts in the given blog.
+	 */
+	List<BlogPostHeader> getPostHeaders(Transaction txn, GroupId g)
+			throws DbException;
+
 	/**
 	 * Marks a blog post as read or unread.
 	 */

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

@@ -1,7 +1,7 @@
 package org.briarproject.briar.api.blog;
 
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorInfo;
+import org.briarproject.briar.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;

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/client/MessageTracker.java

@@ -61,8 +61,11 @@ public interface MessageTracker {
 
 	/**
 	 * Marks a message as read or unread and updates the group count.
+	 *
+	 * @return True if the message was previously marked as read
 	 */
-	void setReadFlag(GroupId g, MessageId m, boolean read) throws DbException;
+	boolean setReadFlag(Transaction txn, GroupId g, MessageId m, boolean read)
+			throws DbException;
 
 	/**
 	 * Resets the {@link GroupCount} to the given msgCount and unreadCount.

briar-api/src/main/java/org/briarproject/briar/api/client/MessageTree.java

@@ -4,7 +4,7 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
 
 import java.util.Collection;
-import java.util.Comparator;
+import java.util.List;
 
 import javax.annotation.Nullable;
 
@@ -15,11 +15,9 @@ public interface MessageTree<T extends MessageTree.MessageNode> {
 
 	void add(T node);
 
-	void setComparator(Comparator<T> comparator);
-
 	void clear();
 
-	Collection<T> depthFirstOrder();
+	List<T> depthFirstOrder();
 
 	boolean contains(MessageId m);
 

briar-api/src/main/java/org/briarproject/briar/api/client/PostHeader.java

@@ -1,8 +1,8 @@
 package org.briarproject.briar.api.client;
 
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorInfo;
-import org.briarproject.bramble.api.identity.AuthorInfo.Status;
+import org.briarproject.briar.api.identity.AuthorInfo;
+import org.briarproject.briar.api.identity.AuthorInfo.Status;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
 

briar-api/src/main/java/org/briarproject/briar/api/conversation/ConversationManager.java

@@ -21,7 +21,6 @@ public interface ConversationManager {
 	int DELETE_SESSION_INVITATION_INCOMPLETE = 1 << 1;
 	int DELETE_SESSION_INTRODUCTION_IN_PROGRESS = 1 << 2;
 	int DELETE_SESSION_INVITATION_IN_PROGRESS = 1 << 3;
-	int DELETE_NOT_DOWNLOADED = 1 << 4;
 
 	/**
 	 * Clients that present messages in a private conversation need to
@@ -43,6 +42,21 @@ public interface ConversationManager {
 	 */
 	GroupCount getGroupCount(ContactId c) throws DbException;
 
+	/**
+	 * Returns the unified group count for all private conversation messages.
+	 */
+	GroupCount getGroupCount(Transaction txn, ContactId c) throws DbException;
+
+	void setReadFlag(GroupId g, MessageId m, boolean read)
+			throws DbException;
+
+	/**
+	 * Returns a timestamp for an outgoing message, which is later than the
+	 * timestamp of any message in the conversation with the given contact.
+	 */
+	long getTimestampForOutgoingMessage(Transaction txn, ContactId c)
+			throws DbException;
+
 	/**
 	 * Deletes all messages exchanged with the given contact.
 	 */
@@ -72,9 +86,6 @@ public interface ConversationManager {
 		GroupCount getGroupCount(Transaction txn, ContactId c)
 				throws DbException;
 
-		void setReadFlag(GroupId g, MessageId m, boolean read)
-				throws DbException;
-
 		/**
 		 * Deletes all messages associated with the given contact.
 		 */

briar-api/src/main/java/org/briarproject/briar/api/conversation/ConversationMessageHeader.java

@@ -12,18 +12,20 @@ public abstract class ConversationMessageHeader {
 
 	private final MessageId id;
 	private final GroupId groupId;
-	private final long timestamp;
-	private final boolean local, sent, seen, read;
+	private final long timestamp, autoDeleteTimer;
+	private final boolean local, read, sent, seen;
 
-	public ConversationMessageHeader(MessageId id, GroupId groupId, long timestamp,
-			boolean local, boolean read, boolean sent, boolean seen) {
+	public ConversationMessageHeader(MessageId id, GroupId groupId,
+			long timestamp, boolean local, boolean read, boolean sent,
+			boolean seen, long autoDeleteTimer) {
 		this.id = id;
 		this.groupId = groupId;
 		this.timestamp = timestamp;
 		this.local = local;
+		this.read = read;
 		this.sent = sent;
 		this.seen = seen;
-		this.read = read;
+		this.autoDeleteTimer = autoDeleteTimer;
 	}
 
 	public MessageId getId() {
@@ -55,4 +57,8 @@ public abstract class ConversationMessageHeader {
 	}
 
 	public abstract <T> T accept(ConversationMessageVisitor<T> v);
+
+	public long getAutoDeleteTimer() {
+		return autoDeleteTimer;
+	}
 }

briar-api/src/main/java/org/briarproject/briar/api/conversation/ConversationRequest.java

@@ -20,11 +20,12 @@ public abstract class ConversationRequest<N extends Nameable>
 	private final String text;
 	private final boolean answered;
 
-	public ConversationRequest(MessageId messageId, GroupId groupId, long time,
-			boolean local, boolean read, boolean sent, boolean seen,
-			SessionId sessionId, N nameable, @Nullable String text,
-			boolean answered) {
-		super(messageId, groupId, time, local, read, sent, seen);
+	public ConversationRequest(MessageId messageId, GroupId groupId,
+			long timestamp, boolean local, boolean read, boolean sent,
+			boolean seen, SessionId sessionId, N nameable,
+			@Nullable String text, boolean answered, long autoDeleteTimer) {
+		super(messageId, groupId, timestamp, local, read, sent, seen,
+				autoDeleteTimer);
 		this.sessionId = sessionId;
 		this.nameable = nameable;
 		this.text = text;

briar-api/src/main/java/org/briarproject/briar/api/conversation/ConversationResponse.java

@@ -12,14 +12,16 @@ import javax.annotation.concurrent.Immutable;
 public abstract class ConversationResponse extends ConversationMessageHeader {
 
 	private final SessionId sessionId;
-	private final boolean accepted;
+	private final boolean accepted, isAutoDecline;
 
 	public ConversationResponse(MessageId id, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
-			SessionId sessionId, boolean accepted) {
-		super(id, groupId, time, local, read, sent, seen);
+			SessionId sessionId, boolean accepted, long autoDeleteTimer,
+			boolean isAutoDecline) {
+		super(id, groupId, time, local, read, sent, seen, autoDeleteTimer);
 		this.sessionId = sessionId;
 		this.accepted = accepted;
+		this.isAutoDecline = isAutoDecline;
 	}
 
 	public SessionId getSessionId() {
@@ -30,4 +32,7 @@ public abstract class ConversationResponse extends ConversationMessageHeader {
 		return accepted;
 	}
 
+	public boolean isAutoDecline() {
+		return isAutoDecline;
+	}
 }

briar-api/src/main/java/org/briarproject/briar/api/conversation/DeletionResult.java

@@ -4,7 +4,6 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import javax.annotation.concurrent.NotThreadSafe;
 
-import static org.briarproject.briar.api.conversation.ConversationManager.DELETE_NOT_DOWNLOADED;
 import static org.briarproject.briar.api.conversation.ConversationManager.DELETE_SESSION_INTRODUCTION_INCOMPLETE;
 import static org.briarproject.briar.api.conversation.ConversationManager.DELETE_SESSION_INTRODUCTION_IN_PROGRESS;
 import static org.briarproject.briar.api.conversation.ConversationManager.DELETE_SESSION_INVITATION_INCOMPLETE;
@@ -36,10 +35,6 @@ public class DeletionResult {
 		result |= DELETE_SESSION_INTRODUCTION_IN_PROGRESS;
 	}
 
-	public void addNotFullyDownloaded() {
-		result |= DELETE_NOT_DOWNLOADED;
-	}
-
 	public boolean allDeleted() {
 		return result == 0;
 	}
@@ -59,9 +54,4 @@ public class DeletionResult {
 	public boolean hasNotAllInvitationSelected() {
 		return (result & DELETE_SESSION_INVITATION_INCOMPLETE) != 0;
 	}
-
-	public boolean hasNotFullyDownloaded() {
-		return (result & DELETE_NOT_DOWNLOADED) != 0;
-	}
-
 }

briar-api/src/main/java/org/briarproject/briar/api/feed/Feed.java

@@ -10,7 +10,7 @@ import javax.annotation.concurrent.Immutable;
 
 @Immutable
 @NotNullByDefault
-public class Feed {
+public class Feed implements Comparable<Feed> {
 
 	private final String url;
 	private final Blog blog;
@@ -94,4 +94,13 @@ public class Feed {
 		return false;
 	}
 
+	@Override
+	public int compareTo(Feed o) {
+		if (this == o) return 0;
+		long aTime = getAdded(), bTime = o.getAdded();
+		if (aTime > bTime) return -1;
+		if (aTime < bTime) return 1;
+		return 0;
+	}
+
 }

briar-api/src/main/java/org/briarproject/briar/api/feed/FeedManager.java

@@ -1,6 +1,7 @@
 package org.briarproject.briar.api.feed;
 
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.ClientId;
 
@@ -23,7 +24,7 @@ public interface FeedManager {
 	/**
 	 * Adds an RSS feed as a new dedicated blog.
 	 */
-	void addFeed(String url) throws DbException, IOException;
+	Feed addFeed(String url) throws DbException, IOException;
 
 	/**
 	 * Removes an RSS feed.
@@ -35,4 +36,8 @@ public interface FeedManager {
 	 */
 	List<Feed> getFeeds() throws DbException;
 
+	/**
+	 * Returns a list of all added RSS feeds
+	 */
+	List<Feed> getFeeds(Transaction txn) throws DbException;
 }

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, boolean isAutoDecline) {
 		super(id, groupId, time, local, read, sent, seen, sessionId,
-				accept, shareableId);
+				accept, shareableId, autoDeleteTimer, isAutoDecline);
 	}
 
 	@Override

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

@@ -11,6 +11,7 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.client.MessageTracker.GroupCount;
 
 import java.util.Collection;
+import java.util.List;
 
 import javax.annotation.Nullable;
 
@@ -59,6 +60,12 @@ public interface ForumManager {
 	 */
 	ForumPostHeader addLocalPost(ForumPost p) throws DbException;
 
+	/**
+	 * Stores a local forum post.
+	 */
+	ForumPostHeader addLocalPost(Transaction txn, ForumPost p)
+			throws DbException;
+
 	/**
 	 * Returns the forum with the given ID.
 	 */
@@ -74,16 +81,32 @@ public interface ForumManager {
 	 */
 	Collection<Forum> getForums() throws DbException;
 
+	/**
+	 * Returns all forums to which the user subscribes.
+	 */
+	Collection<Forum> getForums(Transaction txn) throws DbException;
+
 	/**
 	 * Returns the text of the forum post with the given ID.
 	 */
 	String getPostText(MessageId m) throws DbException;
 
+	/**
+	 * Returns the text of the forum post with the given ID.
+	 */
+	String getPostText(Transaction txn, MessageId m) throws DbException;
+
 	/**
 	 * Returns the headers of all posts in the given forum.
 	 */
 	Collection<ForumPostHeader> getPostHeaders(GroupId g) throws DbException;
 
+	/**
+	 * Returns the headers of all posts in the given forum.
+	 */
+	List<ForumPostHeader> getPostHeaders(Transaction txn, GroupId g)
+			throws DbException;
+
 	/**
 	 * Registers a hook to be called whenever a forum is removed.
 	 */
@@ -94,6 +117,11 @@ public interface ForumManager {
 	 */
 	GroupCount getGroupCount(GroupId g) throws DbException;
 
+	/**
+	 * Returns the group count for the given forum.
+	 */
+	GroupCount getGroupCount(Transaction txn, GroupId g) throws DbException;
+
 	/**
 	 * Marks a message as read or unread and updates the group count.
 	 */

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

@@ -1,7 +1,7 @@
 package org.briarproject.briar.api.forum;
 
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorInfo;
+import org.briarproject.briar.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.client.PostHeader;

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/identity/AuthorInfo.java

@@ -0,0 +1,70 @@
+package org.briarproject.briar.api.identity;
+
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+import org.briarproject.bramble.api.nullsafety.NullSafety;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
+
+import javax.annotation.Nullable;
+import javax.annotation.concurrent.Immutable;
+
+@Immutable
+@NotNullByDefault
+public class AuthorInfo {
+
+	public enum Status {
+		NONE, ANONYMOUS, UNKNOWN, UNVERIFIED, VERIFIED, OURSELVES;
+
+		public boolean isContact() {
+			return this == UNVERIFIED || this == VERIFIED;
+		}
+	}
+
+	private final Status status;
+	@Nullable
+	private final String alias;
+	@Nullable
+	private final AttachmentHeader avatarHeader;
+
+	public AuthorInfo(Status status, @Nullable String alias,
+			@Nullable AttachmentHeader avatarHeader) {
+		this.status = status;
+		this.alias = alias;
+		this.avatarHeader = avatarHeader;
+	}
+
+	public AuthorInfo(Status status) {
+		this(status, null, null);
+	}
+
+	public Status getStatus() {
+		return status;
+	}
+
+	@Nullable
+	public String getAlias() {
+		return alias;
+	}
+
+	@Nullable
+	public AttachmentHeader getAvatarHeader() {
+		return avatarHeader;
+	}
+
+	@Override
+	public int hashCode() {
+		int hashCode = status.ordinal();
+		if (alias != null) hashCode += alias.hashCode();
+		return hashCode;
+	}
+
+	@Override
+	public boolean equals(Object o) {
+		if (!(o instanceof AuthorInfo)) return false;
+		AuthorInfo info = (AuthorInfo) o;
+		return status == info.status &&
+				// aliases are equal
+				NullSafety.equals(alias, info.alias) &&
+				// avatars are equal
+				NullSafety.equals(avatarHeader, info.avatarHeader);
+	}
+}

briar-api/src/main/java/org/briarproject/briar/api/identity/AuthorManager.java

@@ -0,0 +1,43 @@
+package org.briarproject.briar.api.identity;
+
+import org.briarproject.bramble.api.contact.Contact;
+import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
+import org.briarproject.bramble.api.identity.AuthorId;
+import org.briarproject.bramble.api.identity.LocalAuthor;
+import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
+
+@NotNullByDefault
+public interface AuthorManager {
+
+	/**
+	 * Returns the {@link AuthorInfo} for the given author.
+	 */
+	AuthorInfo getAuthorInfo(AuthorId a) throws DbException;
+
+	/**
+	 * Returns the {@link AuthorInfo} for the given author.
+	 */
+	AuthorInfo getAuthorInfo(Transaction txn, AuthorId a) throws DbException;
+
+	/**
+	 * Returns the {@link AuthorInfo} for the given contact.
+	 */
+	AuthorInfo getAuthorInfo(Contact c) throws DbException;
+
+	/**
+	 * Returns the {@link AuthorInfo} for the given contact.
+	 */
+	AuthorInfo getAuthorInfo(Transaction txn, Contact c)
+			throws DbException;
+
+	/**
+	 * Returns the {@link AuthorInfo} for the {@link LocalAuthor}.
+	 */
+	AuthorInfo getMyAuthorInfo() throws DbException;
+
+	/**
+	 * Returns the {@link AuthorInfo} for the {@link LocalAuthor}.
+	 */
+	AuthorInfo getMyAuthorInfo(Transaction txn) throws DbException;
+}

briar-api/src/main/java/org/briarproject/briar/api/introduction/IntroductionManager.java

@@ -31,18 +31,18 @@ public interface IntroductionManager extends ConversationClient {
 	/**
 	 * The current minor version of the introduction client.
 	 */
-	int MINOR_VERSION = 0;
+	int MINOR_VERSION = 1;
 
 	/**
 	 * Sends two initial introduction messages.
 	 */
-	void makeIntroduction(Contact c1, Contact c2, @Nullable String text,
-			long timestamp) throws DbException;
+	void makeIntroduction(Contact c1, Contact c2, @Nullable String text)
+			throws DbException;
 
 	/**
 	 * Responds to an introduction.
 	 */
 	void respondToIntroduction(ContactId contactId, SessionId sessionId,
-			long timestamp, boolean accept) throws DbException;
+			boolean accept) throws DbException;
 
 }

briar-api/src/main/java/org/briarproject/briar/api/introduction/IntroductionRequest.java

@@ -1,7 +1,7 @@
 package org.briarproject.briar.api.introduction;
 
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorInfo;
+import org.briarproject.briar.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
@@ -18,12 +18,12 @@ public class IntroductionRequest extends ConversationRequest<Author> {
 
 	private final AuthorInfo authorInfo;
 
-	public IntroductionRequest(MessageId messageId, GroupId groupId,
-			long time, boolean local, boolean read, boolean sent, boolean seen,
+	public IntroductionRequest(MessageId messageId, GroupId groupId, long time,
+			boolean local, boolean read, boolean sent, boolean seen,
 			SessionId sessionId, Author author, @Nullable String text,
-			boolean answered, AuthorInfo authorInfo) {
+			boolean answered, AuthorInfo authorInfo, long autoDeleteTimer) {
 		super(messageId, groupId, time, local, read, sent, seen, sessionId,
-				author, text, answered);
+				author, text, answered, autoDeleteTimer);
 		this.authorInfo = authorInfo;
 	}
 

briar-api/src/main/java/org/briarproject/briar/api/introduction/IntroductionResponse.java

@@ -1,13 +1,13 @@
 package org.briarproject.briar.api.introduction;
 
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.client.SessionId;
 import org.briarproject.briar.api.conversation.ConversationMessageVisitor;
 import org.briarproject.briar.api.conversation.ConversationResponse;
+import org.briarproject.briar.api.identity.AuthorInfo;
 
 import javax.annotation.concurrent.Immutable;
 
@@ -25,9 +25,10 @@ public class IntroductionResponse extends ConversationResponse {
 	public IntroductionResponse(MessageId messageId, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
 			SessionId sessionId, boolean accepted, Author author,
-			AuthorInfo introducedAuthorInfo, Role role, boolean canSucceed) {
+			AuthorInfo introducedAuthorInfo, Role role, boolean canSucceed,
+			long autoDeleteTimer, boolean isAutoDecline) {
 		super(messageId, groupId, time, local, read, sent, seen, sessionId,
-				accepted);
+				accepted, autoDeleteTimer, isAutoDecline);
 		this.introducedAuthor = author;
 		this.introducedAuthorInfo = introducedAuthorInfo;
 		this.ourRole = role;

briar-api/src/main/java/org/briarproject/briar/api/messaging/InvalidAttachmentException.java

@@ -1,14 +0,0 @@
-package org.briarproject.briar.api.messaging;
-
-import org.briarproject.bramble.api.db.DbException;
-import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
-
-/**
- * An exception that is thrown when an {@link AttachmentHeader} is used to
- * load an {@link Attachment}, and the header refers to a message that is not
- * an attachment, or to an attachment that does not have the expected content
- * type.
- */
-@NotNullByDefault
-public class InvalidAttachmentException extends DbException {
-}

briar-api/src/main/java/org/briarproject/briar/api/messaging/MessagingConstants.java

@@ -7,22 +7,21 @@ public interface MessagingConstants {
 	/**
 	 * The maximum length of a private message's text in UTF-8 bytes.
 	 */
-	int MAX_PRIVATE_MESSAGE_TEXT_LENGTH = MAX_MESSAGE_BODY_LENGTH - 1024;
+	int MAX_PRIVATE_MESSAGE_TEXT_LENGTH = MAX_MESSAGE_BODY_LENGTH - 2048;
+
+	/**
+	 * The maximum length of an incoming private message's text in UTF-8 bytes.
+	 * This is higher than MAX_PRIVATE_MESSAGE_TEXT_LENGTH for compatibility
+	 * with older peers.
+	 * <p>
+	 * TODO: Remove after a reasonable migration period (added 2021-03-12).
+	 */
+	int MAX_PRIVATE_MESSAGE_INCOMING_TEXT_LENGTH =
+			MAX_MESSAGE_BODY_LENGTH - 1024;
 
 	/**
 	 * The maximum number of attachments per private message.
 	 */
 	int MAX_ATTACHMENTS_PER_MESSAGE = 10;
 
-	/**
-	 * The maximum length of an attachment's content type in UTF-8 bytes.
-	 */
-	int MAX_CONTENT_TYPE_BYTES = 50;
-
-	/**
-	 * The maximum allowed size of image attachments.
-	 * TODO: Different limit for GIFs?
-	 */
-	int MAX_IMAGE_SIZE = MAX_MESSAGE_BODY_LENGTH - 100; // 6 * 1024 * 1024;
-
 }

briar-api/src/main/java/org/briarproject/briar/api/messaging/MessagingManager.java

@@ -7,6 +7,8 @@ import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.ClientId;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
+import org.briarproject.briar.api.attachment.FileTooBigException;
 import org.briarproject.briar.api.conversation.ConversationManager.ConversationClient;
 
 import java.io.IOException;
@@ -30,13 +32,18 @@ public interface MessagingManager extends ConversationClient {
 	/**
 	 * The current minor version of the messaging client.
 	 */
-	int MINOR_VERSION = 2;
+	int MINOR_VERSION = 3;
 
 	/**
 	 * Stores a local private message.
 	 */
 	void addLocalMessage(PrivateMessage m) throws DbException;
 
+	/**
+	 * Stores a local private message.
+	 */
+	void addLocalMessage(Transaction txn, PrivateMessage m) throws DbException;
+
 	/**
 	 * Stores a local attachment message.
 	 *
@@ -68,21 +75,8 @@ public interface MessagingManager extends ConversationClient {
 	String getMessageText(MessageId m) throws DbException;
 
 	/**
-	 * Returns the attachment with the given message ID and content type.
-	 *
-	 * @throws InvalidAttachmentException If the header refers to a message
-	 * that is not an attachment, or to an attachment that does not have the
-	 * expected content type
+	 * Returns the private message format supported by the given contact.
 	 */
-	Attachment getAttachment(AttachmentHeader h) throws DbException;
-
-	/**
-	 * Returns true if the contact with the given {@link ContactId} does support
-	 * image attachments.
-	 *
-	 * Added: 2019-01-01
-	 */
-	boolean contactSupportsImages(Transaction txn, ContactId c)
+	PrivateMessageFormat getContactMessageFormat(Transaction txn, ContactId c)
 			throws DbException;
-
 }

briar-api/src/main/java/org/briarproject/briar/api/messaging/PrivateMessage.java

@@ -2,50 +2,73 @@ package org.briarproject.briar.api.messaging;
 
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.Message;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 
 import java.util.List;
 
 import javax.annotation.concurrent.Immutable;
 
 import static java.util.Collections.emptyList;
+import static org.briarproject.briar.api.autodelete.AutoDeleteConstants.NO_AUTO_DELETE_TIMER;
+import static org.briarproject.briar.api.messaging.PrivateMessageFormat.TEXT_IMAGES;
+import static org.briarproject.briar.api.messaging.PrivateMessageFormat.TEXT_IMAGES_AUTO_DELETE;
+import static org.briarproject.briar.api.messaging.PrivateMessageFormat.TEXT_ONLY;
 
 @Immutable
 @NotNullByDefault
 public class PrivateMessage {
 
 	private final Message message;
-	private final boolean legacyFormat, hasText;
+	private final boolean hasText;
 	private final List<AttachmentHeader> attachmentHeaders;
+	private final long autoDeleteTimer;
+	private final PrivateMessageFormat format;
 
 	/**
-	 * Constructor for private messages in the legacy format, which does not
-	 * support attachments.
+	 * Constructor for private messages in the
+	 * {@link PrivateMessageFormat#TEXT_ONLY TEXT_ONLY} format.
 	 */
 	public PrivateMessage(Message message) {
 		this.message = message;
-		legacyFormat = true;
 		hasText = true;
 		attachmentHeaders = emptyList();
+		autoDeleteTimer = NO_AUTO_DELETE_TIMER;
+		format = TEXT_ONLY;
 	}
 
 	/**
-	 * Constructor for private messages in the current format, which supports
-	 * attachments.
+	 * Constructor for private messages in the
+	 * {@link PrivateMessageFormat#TEXT_IMAGES TEXT_IMAGES} format.
 	 */
 	public PrivateMessage(Message message, boolean hasText,
 			List<AttachmentHeader> headers) {
 		this.message = message;
 		this.hasText = hasText;
 		this.attachmentHeaders = headers;
-		legacyFormat = false;
+		autoDeleteTimer = NO_AUTO_DELETE_TIMER;
+		format = TEXT_IMAGES;
+	}
+
+	/**
+	 * Constructor for private messages in the
+	 * {@link PrivateMessageFormat#TEXT_IMAGES_AUTO_DELETE TEXT_IMAGES_AUTO_DELETE}
+	 * format.
+	 */
+	public PrivateMessage(Message message, boolean hasText,
+			List<AttachmentHeader> headers, long autoDeleteTimer) {
+		this.message = message;
+		this.hasText = hasText;
+		this.attachmentHeaders = headers;
+		this.autoDeleteTimer = autoDeleteTimer;
+		format = TEXT_IMAGES_AUTO_DELETE;
 	}
 
 	public Message getMessage() {
 		return message;
 	}
 
-	public boolean isLegacyFormat() {
-		return legacyFormat;
+	public PrivateMessageFormat getFormat() {
+		return format;
 	}
 
 	public boolean hasText() {
@@ -55,4 +78,8 @@ public class PrivateMessage {
 	public List<AttachmentHeader> getAttachmentHeaders() {
 		return attachmentHeaders;
 	}
+
+	public long getAutoDeleteTimer() {
+		return autoDeleteTimer;
+	}
 }

briar-api/src/main/java/org/briarproject/briar/api/messaging/PrivateMessageFactory.java

@@ -3,6 +3,7 @@ package org.briarproject.briar.api.messaging;
 import org.briarproject.bramble.api.FormatException;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 
 import java.util.List;
 
@@ -11,11 +12,29 @@ import javax.annotation.Nullable;
 @NotNullByDefault
 public interface PrivateMessageFactory {
 
+	/**
+	 * Creates a private message in the
+	 * {@link PrivateMessageFormat#TEXT_ONLY TEXT_ONLY} format.
+	 */
 	PrivateMessage createLegacyPrivateMessage(GroupId groupId, long timestamp,
 			String text) throws FormatException;
 
+	/**
+	 * Creates a private message in the
+	 * {@link PrivateMessageFormat#TEXT_IMAGES TEXT_IMAGES} format. This format
+	 * requires the contact to support client version 0.1 or higher.
+	 */
 	PrivateMessage createPrivateMessage(GroupId groupId, long timestamp,
 			@Nullable String text, List<AttachmentHeader> headers)
 			throws FormatException;
 
+	/**
+	 * Creates a private message in the
+	 * {@link PrivateMessageFormat#TEXT_IMAGES_AUTO_DELETE TEXT_IMAGES_AUTO_DELETE}
+	 * format. This format requires the contact to support client version 0.3
+	 * or higher.
+	 */
+	PrivateMessage createPrivateMessage(GroupId groupId, long timestamp,
+			@Nullable String text, List<AttachmentHeader> headers,
+			long autoDeleteTimer) throws FormatException;
 }

briar-api/src/main/java/org/briarproject/briar/api/messaging/PrivateMessageFormat.java

@@ -0,0 +1,24 @@
+package org.briarproject.briar.api.messaging;
+
+public enum PrivateMessageFormat {
+
+	/**
+	 * First version of the private message format, which doesn't support
+	 * image attachments or auto-deletion.
+	 */
+	TEXT_ONLY,
+
+	/**
+	 * Second version of the private message format, which supports image
+	 * attachments but not auto-deletion. Support for this format was
+	 * added in client version 0.1.
+	 */
+	TEXT_IMAGES,
+
+	/**
+	 * Third version of the private message format, which supports image
+	 * attachments and auto-deletion. Support for this format was added
+	 * in client version 0.3.
+	 */
+	TEXT_IMAGES_AUTO_DELETE
+}

briar-api/src/main/java/org/briarproject/briar/api/messaging/PrivateMessageHeader.java

@@ -3,6 +3,7 @@ package org.briarproject.briar.api.messaging;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
 import org.briarproject.briar.api.conversation.ConversationMessageHeader;
 import org.briarproject.briar.api.conversation.ConversationMessageVisitor;
 
@@ -19,8 +20,9 @@ public class PrivateMessageHeader extends ConversationMessageHeader {
 
 	public PrivateMessageHeader(MessageId id, GroupId groupId, long timestamp,
 			boolean local, boolean read, boolean sent, boolean seen,
-			boolean hasText, List<AttachmentHeader> headers) {
-		super(id, groupId, timestamp, local, read, sent, seen);
+			boolean hasText, List<AttachmentHeader> headers,
+			long autoDeleteTimer) {
+		super(id, groupId, timestamp, local, read, sent, seen, autoDeleteTimer);
 		this.hasText = hasText;
 		this.attachmentHeaders = headers;
 	}
@@ -37,5 +39,4 @@ public class PrivateMessageHeader extends ConversationMessageHeader {
 	public <T> T accept(ConversationMessageVisitor<T> v) {
 		return v.visitPrivateMessageHeader(this);
 	}
-
 }

briar-api/src/main/java/org/briarproject/briar/api/privategroup/GroupMember.java

@@ -2,7 +2,7 @@ package org.briarproject.briar.api.privategroup;
 
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorInfo;
+import org.briarproject.briar.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 
 import javax.annotation.Nullable;

briar-api/src/main/java/org/briarproject/briar/api/privategroup/GroupMessageHeader.java

@@ -1,7 +1,7 @@
 package org.briarproject.briar.api.privategroup;
 
 import org.briarproject.bramble.api.identity.Author;
-import org.briarproject.bramble.api.identity.AuthorInfo;
+import org.briarproject.briar.api.identity.AuthorInfo;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.bramble.api.sync.MessageId;

briar-api/src/main/java/org/briarproject/briar/api/privategroup/JoinMessageHeader.java

@@ -8,21 +8,14 @@ import javax.annotation.concurrent.Immutable;
 @NotNullByDefault
 public class JoinMessageHeader extends GroupMessageHeader {
 
-	private final Visibility visibility;
 	private final boolean isInitial;
 
-	public JoinMessageHeader(GroupMessageHeader h, Visibility visibility,
-			boolean isInitial) {
+	public JoinMessageHeader(GroupMessageHeader h, boolean isInitial) {
 		super(h.getGroupId(), h.getId(), h.getParentId(), h.getTimestamp(),
 				h.getAuthor(), h.getAuthorInfo(), h.isRead());
-		this.visibility = visibility;
 		this.isInitial = isInitial;
 	}
 
-	public Visibility getVisibility() {
-		return visibility;
-	}
-
 	public boolean isInitial() {
 		return isInitial;
 	}

briar-api/src/main/java/org/briarproject/briar/api/privategroup/PrivateGroupManager.java

@@ -12,6 +12,7 @@ import org.briarproject.bramble.api.sync.MessageId;
 import org.briarproject.briar.api.client.MessageTracker.GroupCount;
 
 import java.util.Collection;
+import java.util.List;
 
 @NotNullByDefault
 public interface PrivateGroupManager {
@@ -66,6 +67,11 @@ public interface PrivateGroupManager {
 	 */
 	void markGroupDissolved(Transaction txn, GroupId g) throws DbException;
 
+	/**
+	 * Returns true if the given private group has been dissolved.
+	 */
+	boolean isDissolved(Transaction txn, GroupId g) throws DbException;
+
 	/**
 	 * Returns true if the given private group has been dissolved.
 	 */
@@ -76,6 +82,12 @@ public interface PrivateGroupManager {
 	 */
 	GroupMessageHeader addLocalMessage(GroupMessage p) throws DbException;
 
+	/**
+	 * Stores and sends a local private group message.
+	 */
+	GroupMessageHeader addLocalMessage(Transaction txn, GroupMessage p)
+			throws DbException;
+
 	/**
 	 * Returns the private group with the given ID.
 	 */
@@ -91,26 +103,54 @@ public interface PrivateGroupManager {
 	 */
 	Collection<PrivateGroup> getPrivateGroups() throws DbException;
 
+	/**
+	 * Returns all private groups the user is a member of.
+	 */
+	Collection<PrivateGroup> getPrivateGroups(Transaction txn)
+			throws DbException;
+
 	/**
 	 * Returns the text of the private group message with the given ID.
 	 */
 	String getMessageText(MessageId m) throws DbException;
 
+	/**
+	 * Returns the text of the private group message with the given ID.
+	 */
+	String getMessageText(Transaction txn, MessageId m) throws DbException;
+
 	/**
 	 * Returns the headers of all messages in the given private group.
 	 */
 	Collection<GroupMessageHeader> getHeaders(GroupId g) throws DbException;
 
+	/**
+	 * Returns the headers of all messages in the given private group.
+	 */
+	List<GroupMessageHeader> getHeaders(Transaction txn, GroupId g)
+			throws DbException;
+
 	/**
 	 * Returns all members of the given private group.
 	 */
 	Collection<GroupMember> getMembers(GroupId g) throws DbException;
 
+	/**
+	 * Returns all members of the given private group.
+	 */
+	Collection<GroupMember> getMembers(Transaction txn, GroupId g)
+			throws DbException;
+
 	/**
 	 * Returns true if the given author is a member of the given private group.
 	 */
 	boolean isMember(Transaction txn, GroupId g, Author a) throws DbException;
 
+	/**
+	 * Returns the group count for the given private group.
+	 */
+	GroupCount getGroupCount(Transaction txn, GroupId g) throws DbException;
+
 	/**
 	 * Returns the group count for the given private group.
 	 */

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

@@ -32,7 +32,7 @@ public interface GroupInvitationManager extends ConversationClient {
 	/**
 	 * The current minor version of the private group invitation client.
 	 */
-	int MINOR_VERSION = 0;
+	int MINOR_VERSION = 1;
 
 	/**
 	 * Sends an invitation to share the given private group with the given
@@ -43,7 +43,8 @@ public interface GroupInvitationManager extends ConversationClient {
 	 * pending.
 	 */
 	void sendInvitation(GroupId g, ContactId c, @Nullable String text,
-			long timestamp, byte[] signature) throws DbException;
+			long timestamp, byte[] signature, long autoDeleteTimer)
+			throws DbException;
 
 	/**
 	 * Responds to a pending private group invitation from the given contact.

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

@@ -18,9 +18,10 @@ public class GroupInvitationRequest extends InvitationRequest<PrivateGroup> {
 	public GroupInvitationRequest(MessageId id, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
 			SessionId sessionId, PrivateGroup shareable,
-			@Nullable String text, boolean available, boolean canBeOpened) {
+			@Nullable String text, boolean available, boolean canBeOpened,
+			long autoDeleteTimer) {
 		super(id, groupId, time, local, read, sent, seen, sessionId, shareable,
-				text, available, canBeOpened);
+				text, available, canBeOpened, autoDeleteTimer);
 	}
 
 	@Override

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

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

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

@@ -15,9 +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);
+				object, text, !available, autoDeleteTimer);
 		this.canBeOpened = canBeOpened;
 	}
 

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

@@ -11,8 +11,10 @@ public abstract class InvitationResponse extends ConversationResponse {
 
 	public InvitationResponse(MessageId id, GroupId groupId, long time,
 			boolean local, boolean read, boolean sent, boolean seen,
-			SessionId sessionId, boolean accepted, GroupId shareableId) {
-		super(id, groupId, time, local, read, sent, seen, sessionId, accepted);
+			SessionId sessionId, boolean accepted, GroupId shareableId,
+			long autoDeleteTimer, boolean isAutoDecline) {
+		super(id, groupId, time, local, read, sent, seen, sessionId, accepted,
+				autoDeleteTimer, isAutoDecline);
 		this.shareableId = shareableId;
 	}
 

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

@@ -3,6 +3,7 @@ package org.briarproject.briar.api.sharing;
 import org.briarproject.bramble.api.contact.Contact;
 import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DbException;
+import org.briarproject.bramble.api.db.Transaction;
 import org.briarproject.bramble.api.nullsafety.NotNullByDefault;
 import org.briarproject.bramble.api.sync.GroupId;
 import org.briarproject.briar.api.client.SessionId;
@@ -21,7 +22,7 @@ public interface SharingManager<S extends Shareable>
 	 * including optional text.
 	 */
 	void sendInvitation(GroupId shareableId, ContactId contactId,
-			@Nullable String text, long timestamp) throws DbException;
+			@Nullable String text) throws DbException;
 
 	/**
 	 * Responds to a pending group invitation
@@ -45,6 +46,12 @@ public interface SharingManager<S extends Shareable>
 	 */
 	Collection<Contact> getSharedWith(GroupId g) throws DbException;
 
+	/**
+	 * Returns all contacts with whom the given group is shared.
+	 */
+	Collection<Contact> getSharedWith(Transaction txn, GroupId g)
+			throws DbException;
+
 	/**
 	 * Returns true if the group not already shared and no invitation is open
 	 */

briar-api/src/main/java/org/briarproject/briar/api/test/TestAvatarCreator.java

@@ -0,0 +1,11 @@
+package org.briarproject.briar.api.test;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import javax.annotation.Nullable;
+
+public interface TestAvatarCreator {
+	@Nullable
+	InputStream getAvatarInputStream() throws IOException;
+}

briar-api/src/main/java/org/briarproject/briar/api/test/TestDataCreator.java

@@ -14,13 +14,16 @@ public interface TestDataCreator {
 	 * @param numContacts Number of contacts to create. Must be >= 1
 	 * @param numPrivateMsgs Number of private messages to create for each
 	 * contact.
+	 * @param avatarPercent Percentage of contacts
+	 * that will use a random profile image. Between 0 and 100.
 	 * @param numBlogPosts Number of blog posts to create.
 	 * @param numForums Number of forums to create.
 	 * @param numForumPosts Number of forum posts to create per forum.
 	 */
-	void createTestData(int numContacts, int numPrivateMsgs, int numBlogPosts,
-			int numForums, int numForumPosts);
+	void createTestData(int numContacts, int numPrivateMsgs, int avatarPercent,
+			int numBlogPosts, int numForums, int numForumPosts);
 
 	@IoExecutor
-	Contact addContact(String name) throws DbException;
+	Contact addContact(String name, boolean alias, boolean avatar)
+			throws DbException;
 }

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

@@ -0,0 +1,61 @@
+package org.briarproject.briar.api.identity;
+
+import org.briarproject.bramble.api.sync.GroupId;
+import org.briarproject.bramble.api.sync.MessageId;
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.briarproject.briar.api.attachment.AttachmentHeader;
+import org.junit.Test;
+
+import static org.briarproject.bramble.test.TestUtils.getRandomId;
+import static org.briarproject.bramble.util.StringUtils.getRandomString;
+import static org.briarproject.briar.api.attachment.MediaConstants.MAX_CONTENT_TYPE_BYTES;
+import static org.briarproject.briar.api.identity.AuthorInfo.Status.NONE;
+import static org.briarproject.briar.api.identity.AuthorInfo.Status.VERIFIED;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+public class AuthorInfoTest extends BrambleTestCase {
+
+	private final String contentType = getRandomString(MAX_CONTENT_TYPE_BYTES);
+	private final AttachmentHeader avatarHeader =
+			new AttachmentHeader(new GroupId(getRandomId()),
+					new MessageId(getRandomId()), contentType);
+
+	@Test
+	public void testEquals() {
+		assertEquals(
+				new AuthorInfo(NONE),
+				new AuthorInfo(NONE, null, null)
+		);
+		assertEquals(
+				new AuthorInfo(NONE, "test", null),
+				new AuthorInfo(NONE, "test", null)
+		);
+		assertEquals(
+				new AuthorInfo(NONE, "test", avatarHeader),
+				new AuthorInfo(NONE, "test", avatarHeader)
+		);
+
+		assertNotEquals(
+				new AuthorInfo(NONE),
+				new AuthorInfo(VERIFIED)
+		);
+		assertNotEquals(
+				new AuthorInfo(NONE, "test", null),
+				new AuthorInfo(NONE)
+		);
+		assertNotEquals(
+				new AuthorInfo(NONE),
+				new AuthorInfo(NONE, "test", null)
+		);
+		assertNotEquals(
+				new AuthorInfo(NONE, "a", null),
+				new AuthorInfo(NONE, "b", null)
+		);
+		assertNotEquals(
+				new AuthorInfo(NONE, "a", null),
+				new AuthorInfo(NONE, "a", avatarHeader)
+		);
+	}
+
+}

briar-api/witness.gradle

@@ -1,8 +1,10 @@
 dependencyVerification {
     verify = [
+        'junit:junit:4.13.2:junit-4.13.2.jar:8e495b634469d64fb8acfa3495a065cbacc8a0fff55ce1e31007be4c16dc57d3',
         'org.codehaus.mojo.signature:java16:1.1:java16-1.1.signature:53799223a2c98dba2d0add810bed76315460df285c69e4f397ae6098f87dd619',
         'org.codehaus.mojo:animal-sniffer-ant-tasks:1.16:animal-sniffer-ant-tasks-1.16.jar:890040976fbe2d584619a6a61b1fd2e925b3b5eb342a85eb2762c467c0d64e90',
         'org.codehaus.mojo:animal-sniffer:1.16:animal-sniffer-1.16.jar:72be8bcc226ba43b937c722a08a07852bfa1b11400089265d5df0ee7b38b1d52',
+        'org.hamcrest:hamcrest-core:1.3:hamcrest-core-1.3.jar:66fdef91e9739348df7a096aa384a5685f4e875584cce89386a7a47251c4d8e9',
         'org.ow2.asm:asm-all:5.2:asm-all-5.2.jar:7fbffbc1db3422e2101689fd88df8384b15817b52b9b2b267b9f6d2511dc198d',
     ]
 }