Remove new member announcement and add signature to invitation

briar-api/src/org/briarproject/api/clients/ContactGroupFactory.java

@@ -1,9 +1,9 @@
 package org.briarproject.api.clients;
 
 import org.briarproject.api.contact.Contact;
+import org.briarproject.api.identity.AuthorId;
 import org.briarproject.api.sync.ClientId;
 import org.briarproject.api.sync.Group;
-import org.briarproject.api.sync.GroupFactory;
 
 public interface ContactGroupFactory {
 
@@ -13,4 +13,11 @@ public interface ContactGroupFactory {
 	/** Creates a group for the given client to share with the given contact. */
 	Group createContactGroup(ClientId clientId, Contact contact);
 
+	/**
+	 * Creates a group for the given client to share between the given authors
+	 * identified by their AuthorIds.
+	 */
+	Group createContactGroup(ClientId clientId, AuthorId authorId1,
+			AuthorId authorId2);
+
 }

briar-api/src/org/briarproject/api/privategroup/GroupMessageFactory.java

@@ -10,33 +10,29 @@ import org.jetbrains.annotations.Nullable;
 public interface GroupMessageFactory {
 
 	/**
-	 * Creates a new member announcement that contains the joiner's identity
-	 * and is signed by the creator.
-	 * <p>
-	 * When a new member accepts an invitation to the group,
-	 * the creator sends this new member announcement to the group.
-	 *
-	 * @param groupId   The ID of the group the new member joined
-	 * @param timestamp The current timestamp
-	 * @param creator   The creator of the group with {@param groupId}
-	 * @param member    The new member that has just accepted an invitation
-	 */
-	@CryptoExecutor
-	GroupMessage createNewMemberMessage(GroupId groupId, long timestamp,
-			LocalAuthor creator, Author member);
-
-	/**
-	 * Creates a join announcement message
-	 * that depends on a previous new member announcement.
+	 * Creates a join announcement message for the creator of a group.
 	 *
 	 * @param groupId     The ID of the Group that is being joined
-	 * @param timestamp   Must be equal to the timestamp of the new member message
-	 * @param member      Our own LocalAuthor
-	 * @param newMemberId The MessageId of the new member message
+	 * @param timestamp   Must be greater than the timestamp of the invitation message
+	 * @param creator     The creator's LocalAuthor
 	 */
 	@CryptoExecutor
 	GroupMessage createJoinMessage(GroupId groupId, long timestamp,
-			LocalAuthor member, MessageId newMemberId);
+			LocalAuthor creator);
+
+	/**
+	 * Creates a join announcement message for a joining member.
+	 *
+	 * @param groupId          The ID of the Group that is being joined
+	 * @param timestamp        Must be greater than the timestamp of the
+	 *                         invitation message
+	 * @param member           The member's LocalAuthor
+	 * @param inviteTimestamp  The timestamp of the group invitation message
+	 * @param creatorSignature The creator's signature from the group invitation
+	 */
+	@CryptoExecutor
+	GroupMessage createJoinMessage(GroupId groupId, long timestamp,
+			LocalAuthor member, long inviteTimestamp, byte[] creatorSignature);
 
 	/**
 	 * Creates a group message

briar-api/src/org/briarproject/api/privategroup/MessageType.java

@@ -1,9 +1,8 @@
 package org.briarproject.api.privategroup;
 
 public enum MessageType {
-	NEW_MEMBER(0),
-	JOIN(1),
-	POST(2);
+	JOIN(0),
+	POST(1);
 
 	int value;
 

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

@@ -21,12 +21,10 @@ public interface PrivateGroupManager extends MessageTracker {
 	 * Adds a new private group and joins it.
 	 *
 	 * @param group        The private group to add
-	 * @param newMemberMsg The creator's message announcing herself as
-	 *                     first new member
 	 * @param joinMsg      The creator's own join message
 	 */
-	void addPrivateGroup(PrivateGroup group, GroupMessage newMemberMsg,
-			GroupMessage joinMsg) throws DbException;
+	void addPrivateGroup(PrivateGroup group, GroupMessage joinMsg)
+			throws DbException;
 
 	/** Removes a dissolved private group. */
 	void removePrivateGroup(GroupId g) throws DbException;