Implement closed group logic changes

Session/Conversations/Settings/OWSConversationSettingsViewController.m

@@ -860,7 +860,7 @@ CGFloat kIconViewLength = 24;
     if (gThread.isClosedGroup) {
         NSString *groupPublicKey = [LKGroupUtilities getDecodedGroupID:gThread.groupModel.groupId];
         [LKStorage writeSyncWithBlock:^(YapDatabaseReadWriteTransaction *_Nonnull transaction) {
-            [SNMessageSender leaveClosedGroupWithPublicKey:groupPublicKey using:transaction error:nil];
+            [[SNMessageSender leaveClosedGroupWithPublicKey:groupPublicKey using:transaction] retainUntilComplete];
         }];
     }
 

SessionMessagingKit/Sending & Receiving/MessageReceiver+Handling.swift

@@ -377,7 +377,6 @@ extension MessageReceiver {
     }
     
     private static func handleNewClosedGroup(_ message: ClosedGroupControlMessage, using transaction: Any) {
-        // Prepare
         guard case let .new(publicKeyAsData, name, encryptionKeyPair, membersAsData, adminsAsData) = message.kind else { return }
         let groupPublicKey = publicKeyAsData.toHexString()
         let members = membersAsData.map { $0.toHexString() }
@@ -426,8 +425,8 @@ extension MessageReceiver {
         guard let thread = TSGroupThread.fetch(uniqueId: threadID, transaction: transaction) else {
             return SNLog("Ignoring closed group encryption key pair for nonexistent group.")
         }
-        guard thread.groupModel.groupMemberIds.contains(message.sender!) else {
+        guard thread.groupModel.groupAdminIds.contains(message.sender!) else {
-            return SNLog("Ignoring closed group encryption key pair from non-member.")
+            return SNLog("Ignoring closed group encryption key pair from non-admin.")
         }
         // Find our wrapper and decrypt it if possible
         guard let wrapper = wrappers.first(where: { $0.publicKey == userPublicKey }), let encryptedKeyPair = wrapper.encryptedKeyPair else { return }
@@ -507,6 +506,10 @@ extension MessageReceiver {
             guard members.contains(group.groupAdminIds.first!) else {
                 return SNLog("Ignoring invalid closed group update.")
             }
+            // Check that the message was sent by the group admin
+            guard group.groupAdminIds.contains(message.sender!) else {
+                return SNLog("Ignoring invalid closed group update.")
+            }
             // If the current user was removed:
             // • Stop polling for the group
             // • Remove the key pairs associated with the group
@@ -518,16 +521,6 @@ extension MessageReceiver {
                 Storage.shared.removeAllClosedGroupEncryptionKeyPairs(for: groupPublicKey, using: transaction)
                 let _ = PushNotificationAPI.performOperation(.unsubscribe, for: groupPublicKey, publicKey: userPublicKey)
             }
-            // Generate and distribute a new encryption key pair if needed
-            // NOTE: If we're the admin we can be sure at this point that we weren't removed
-            let isCurrentUserAdmin = group.groupAdminIds.contains(getUserHexEncodedPublicKey())
-            if isCurrentUserAdmin {
-                do {
-                    try MessageSender.generateAndSendNewEncryptionKeyPair(for: groupPublicKey, to: Set(members), using: transaction)
-                } catch {
-                    SNLog("Couldn't distribute new encryption key pair.")
-                }
-            }
             // Update the group
             let newGroupModel = TSGroupModel(title: group.groupName, memberIds: [String](members), image: nil, groupId: groupID, groupType: .closedGroup, adminIds: group.groupAdminIds)
             thread.setGroupModel(newGroupModel, with: transaction)
@@ -547,25 +540,17 @@ extension MessageReceiver {
         performIfValid(for: message, using: transaction) { groupID, thread, group in
             let didAdminLeave = group.groupAdminIds.contains(message.sender!)
             let members: Set<String> = didAdminLeave ? [] : Set(group.groupMemberIds).subtracting([ message.sender! ]) // If the admin leaves the group is disbanded
-            let userPublicKey = getUserHexEncodedPublicKey()
-            let isCurrentUserAdmin = group.groupAdminIds.contains(userPublicKey)
             // If a regular member left:
-            // • Distribute a new encryption key pair if we're the admin of the group
+            // • Mark them as a zombie (to be removed by the admin later)
             // If the admin left:
-            // • Don't distribute a new encryption key pair
             // • Unsubscribe from PNs, delete the group public key, etc. as the group will be disbanded
             if didAdminLeave {
                 // Remove the group from the database and unsubscribe from PNs
                 Storage.shared.removeAllClosedGroupEncryptionKeyPairs(for: groupPublicKey, using: transaction)
                 Storage.shared.removeClosedGroupPublicKey(groupPublicKey, using: transaction)
-                let _ = PushNotificationAPI.performOperation(.unsubscribe, for: groupPublicKey, publicKey: userPublicKey)
+                let _ = PushNotificationAPI.performOperation(.unsubscribe, for: groupPublicKey, publicKey: getUserHexEncodedPublicKey())
-            } else if isCurrentUserAdmin {
+            } else {
-                // Generate and distribute a new encryption key pair if needed
+                // TODO: Mark as zombie
-                do {
-                    try MessageSender.generateAndSendNewEncryptionKeyPair(for: groupPublicKey, to: members, using: transaction)
-                } catch {
-                    SNLog("Couldn't distribute new encryption key pair.")
-                }
             }
             // Update the group
             let newGroupModel = TSGroupModel(title: group.groupName, memberIds: [String](members), image: nil, groupId: groupID, groupType: .closedGroup, adminIds: group.groupAdminIds)
@@ -579,6 +564,7 @@ extension MessageReceiver {
     }
     
     private static func handleClosedGroupEncryptionKeyPairRequest(_ message: ClosedGroupControlMessage, using transaction: Any) {
+        /*
         guard case .encryptionKeyPairRequest = message.kind else { return }
         let transaction = transaction as! YapDatabaseReadWriteTransaction
         guard let groupPublicKey = message.groupPublicKey else { return }
@@ -590,6 +576,7 @@ extension MessageReceiver {
             }
             MessageSender.sendLatestEncryptionKeyPair(to: publicKey, for: groupPublicKey, using: transaction)
         }
+         */
     }
     
     private static func performIfValid(for message: ClosedGroupControlMessage, using transaction: Any, _ update: (Data, TSGroupThread, TSGroupModel) -> Void) {

SessionMessagingKit/Sending & Receiving/MessageSender+ClosedGroups.swift

@@ -29,6 +29,8 @@ extension MessageSender {
             let closedGroupControlMessageKind = ClosedGroupControlMessage.Kind.new(publicKey: Data(hex: groupPublicKey), name: name,
                 encryptionKeyPair: encryptionKeyPair, members: membersAsData, admins: adminsAsData)
             let closedGroupControlMessage = ClosedGroupControlMessage(kind: closedGroupControlMessageKind)
+            // Sending this non-durably is okay because we show a loader to the user. If they close the app while the
+            // loader is still showing, it's within expectation that the group creation might be incomplete.
             let promise = MessageSender.sendNonDurably(closedGroupControlMessage, in: thread, using: transaction)
             promises.append(promise)
         }
@@ -45,34 +47,34 @@ extension MessageSender {
         return when(fulfilled: promises).map2 { thread }
     }
 
-    public static func generateAndSendNewEncryptionKeyPair(for groupPublicKey: String, to targetMembers: Set<String>, using transaction: Any) throws {
+    public static func generateAndSendNewEncryptionKeyPair(for groupPublicKey: String, to targetMembers: Set<String>, using transaction: Any) -> Promise<Void> {
         // Prepare
         let transaction = transaction as! YapDatabaseReadWriteTransaction
         let groupID = LKGroupUtilities.getEncodedClosedGroupIDAsData(groupPublicKey)
         let threadID = TSGroupThread.threadId(fromGroupId: groupID)
         guard let thread = TSGroupThread.fetch(uniqueId: threadID, transaction: transaction) else {
             SNLog("Can't distribute new encryption key pair for nonexistent closed group.")
-            throw Error.noThread
+            return Promise(error: Error.noThread)
         }
         guard thread.groupModel.groupAdminIds.contains(getUserHexEncodedPublicKey()) else {
             SNLog("Can't distribute new encryption key pair as a non-admin.")
-            throw Error.invalidClosedGroupUpdate
+            return Promise(error: Error.invalidClosedGroupUpdate)
         }
         // Generate the new encryption key pair
         let newKeyPair = Curve25519.generateKeyPair()
         // Distribute it
-        let proto = try SNProtoKeyPair.builder(publicKey: newKeyPair.publicKey,
+        let proto = try! SNProtoKeyPair.builder(publicKey: newKeyPair.publicKey,
             privateKey: newKeyPair.privateKey).build()
-        let plaintext = try proto.serializedData()
+        let plaintext = try! proto.serializedData()
-        let wrappers = try targetMembers.compactMap { publicKey -> ClosedGroupControlMessage.KeyPairWrapper in
+        let wrappers = targetMembers.compactMap { publicKey -> ClosedGroupControlMessage.KeyPairWrapper in
-            let ciphertext = try MessageSender.encryptWithSessionProtocol(plaintext, for: publicKey)
+            let ciphertext = try! MessageSender.encryptWithSessionProtocol(plaintext, for: publicKey)
             return ClosedGroupControlMessage.KeyPairWrapper(publicKey: publicKey, encryptedKeyPair: ciphertext)
         }
         let closedGroupControlMessage = ClosedGroupControlMessage(kind: .encryptionKeyPair(publicKey: nil, wrappers: wrappers))
         var distributingKeyPairs = distributingClosedGroupEncryptionKeyPairs[groupPublicKey] ?? []
         distributingKeyPairs.append(newKeyPair)
         distributingClosedGroupEncryptionKeyPairs[groupPublicKey] = distributingKeyPairs
-        let _ = MessageSender.sendNonDurably(closedGroupControlMessage, in: thread, using: transaction).done { // FIXME: It'd be great if we could make this a durable operation
+        return MessageSender.sendNonDurably(closedGroupControlMessage, in: thread, using: transaction).done {
             // Store it * after * having sent out the message to the group
             SNMessagingKitConfiguration.shared.storage.write { transaction in
                 Storage.shared.addClosedGroupEncryptionKeyPair(newKeyPair, for: groupPublicKey, using: transaction)
@@ -82,39 +84,42 @@ extension MessageSender {
                 distributingKeyPairs.remove(at: index)
             }
             distributingClosedGroupEncryptionKeyPairs[groupPublicKey] = distributingKeyPairs
-        }
+        }.map { _ in }
     }
     
-    public static func update(_ groupPublicKey: String, with members: Set<String>, name: String, transaction: YapDatabaseReadWriteTransaction) throws {
+    public static func update(_ groupPublicKey: String, with members: Set<String>, name: String, transaction: YapDatabaseReadWriteTransaction) -> Promise<Void> {
         // Get the group, check preconditions & prepare
         let groupID = LKGroupUtilities.getEncodedClosedGroupIDAsData(groupPublicKey)
         let threadID = TSGroupThread.threadId(fromGroupId: groupID)
         guard let thread = TSGroupThread.fetch(uniqueId: threadID, transaction: transaction) else {
             SNLog("Can't update nonexistent closed group.")
-            throw Error.noThread
+            return Promise(error: Error.noThread)
         }
         let group = thread.groupModel
+        var promises: [Promise<Void>] = []
         // Update name if needed
-        if name != group.groupName { try setName(to: name, for: groupPublicKey, using: transaction) }
+        if name != group.groupName { promises.append(setName(to: name, for: groupPublicKey, using: transaction)) }
         // Add members if needed
         let addedMembers = members.subtracting(group.groupMemberIds)
-        if !addedMembers.isEmpty { try addMembers(addedMembers, to: groupPublicKey, using: transaction) }
+        if !addedMembers.isEmpty { promises.append(addMembers(addedMembers, to: groupPublicKey, using: transaction)) }
         // Remove members if needed
         let removedMembers = Set(group.groupMemberIds).subtracting(members)
-        if !removedMembers.isEmpty { try removeMembers(removedMembers, to: groupPublicKey, using: transaction) }
+        if !removedMembers.isEmpty { promises.append(removeMembers(removedMembers, to: groupPublicKey, using: transaction)) }
+        // Return
+        return when(fulfilled: promises).map2 { _ in }
     }
     
-    public static func setName(to name: String, for groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) throws {
+    public static func setName(to name: String, for groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) -> Promise<Void> {
         // Get the group, check preconditions & prepare
         let groupID = LKGroupUtilities.getEncodedClosedGroupIDAsData(groupPublicKey)
         let threadID = TSGroupThread.threadId(fromGroupId: groupID)
         guard let thread = TSGroupThread.fetch(uniqueId: threadID, transaction: transaction) else {
             SNLog("Can't change name for nonexistent closed group.")
-            throw Error.noThread
+            return Promise(error: Error.noThread)
         }
         guard !name.isEmpty else {
             SNLog("Can't set closed group name to an empty value.")
-            throw Error.invalidClosedGroupUpdate
+            return Promise(error: Error.invalidClosedGroupUpdate)
         }
         let group = thread.groupModel
         // Send the update to the group
@@ -127,19 +132,21 @@ extension MessageSender {
         let updateInfo = group.getInfoStringAboutUpdate(to: newGroupModel)
         let infoMessage = TSInfoMessage(timestamp: NSDate.ows_millisecondTimeStamp(), in: thread, messageType: .groupUpdate, customMessage: updateInfo)
         infoMessage.save(with: transaction)
+        // Return
+        return Promise.value(())
     }
     
-    public static func addMembers(_ newMembers: Set<String>, to groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) throws {
+    public static func addMembers(_ newMembers: Set<String>, to groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) -> Promise<Void> {
         // Get the group, check preconditions & prepare
         let groupID = LKGroupUtilities.getEncodedClosedGroupIDAsData(groupPublicKey)
         let threadID = TSGroupThread.threadId(fromGroupId: groupID)
         guard let thread = TSGroupThread.fetch(uniqueId: threadID, transaction: transaction) else {
             SNLog("Can't add members to nonexistent closed group.")
-            throw Error.noThread
+            return Promise(error: Error.noThread)
         }
         guard !newMembers.isEmpty else {
             SNLog("Invalid closed group update.")
-            throw Error.invalidClosedGroupUpdate
+            return Promise(error: Error.invalidClosedGroupUpdate)
         }
         let group = thread.groupModel
         let members = [String](Set(group.groupMemberIds).union(newMembers))
@@ -147,7 +154,7 @@ extension MessageSender {
         let adminsAsData = group.groupAdminIds.map { Data(hex: $0) }
         guard let encryptionKeyPair = Storage.shared.getLatestClosedGroupEncryptionKeyPair(for: groupPublicKey) else {
             SNLog("Couldn't find encryption key pair for closed group: \(groupPublicKey).")
-            throw Error.noKeyPair
+            return Promise(error: Error.noKeyPair)
         }
         // Send the update to the group
         let closedGroupControlMessage = ClosedGroupControlMessage(kind: .membersAdded(members: newMembers.map { Data(hex: $0) }))
@@ -168,37 +175,38 @@ extension MessageSender {
         let updateInfo = group.getInfoStringAboutUpdate(to: newGroupModel)
         let infoMessage = TSInfoMessage(timestamp: NSDate.ows_millisecondTimeStamp(), in: thread, messageType: .groupUpdate, customMessage: updateInfo)
         infoMessage.save(with: transaction)
+        // Return
+        return Promise.value(())
     }
     
-    public static func removeMembers(_ membersToRemove: Set<String>, to groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) throws {
+    public static func removeMembers(_ membersToRemove: Set<String>, to groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) -> Promise<Void> {
         // Get the group, check preconditions & prepare
         let userPublicKey = getUserHexEncodedPublicKey()
         let groupID = LKGroupUtilities.getEncodedClosedGroupIDAsData(groupPublicKey)
         let threadID = TSGroupThread.threadId(fromGroupId: groupID)
         guard let thread = TSGroupThread.fetch(uniqueId: threadID, transaction: transaction) else {
             SNLog("Can't remove members from nonexistent closed group.")
-            throw Error.noThread
+            return Promise(error: Error.noThread)
         }
         guard !membersToRemove.isEmpty else {
             SNLog("Invalid closed group update.")
-            throw Error.invalidClosedGroupUpdate
+            return Promise(error: Error.invalidClosedGroupUpdate)
         }
         guard !membersToRemove.contains(userPublicKey) else {
             SNLog("Invalid closed group update.")
-            throw Error.invalidClosedGroupUpdate
+            return Promise(error: Error.invalidClosedGroupUpdate)
         }
         let group = thread.groupModel
+        guard group.groupAdminIds.contains(userPublicKey) else {
+            SNLog("Only an admin can remove members from a group.")
+            return Promise(error: Error.invalidClosedGroupUpdate)
+        }
         let members = Set(group.groupMemberIds).subtracting(membersToRemove)
-        let isCurrentUserAdmin = group.groupAdminIds.contains(userPublicKey)
+        // Send the update to the group and generate + distribute a new encryption key pair
-        // Send the update to the group and generate + distribute a new encryption key pair if needed
         let closedGroupControlMessage = ClosedGroupControlMessage(kind: .membersRemoved(members: membersToRemove.map { Data(hex: $0) }))
-        if isCurrentUserAdmin {
+        let promise = MessageSender.sendNonDurably(closedGroupControlMessage, in: thread, using: transaction).map {
-            let _ = MessageSender.sendNonDurably(closedGroupControlMessage, in: thread, using: transaction).done {
+            generateAndSendNewEncryptionKeyPair(for: groupPublicKey, to: members, using: transaction)
-                try generateAndSendNewEncryptionKeyPair(for: groupPublicKey, to: members, using: transaction)
+        }.map { _ in }
-            }
-        } else {
-            MessageSender.send(closedGroupControlMessage, in: thread, using: transaction)
-        }
         // Update the group
         let newGroupModel = TSGroupModel(title: group.groupName, memberIds: [String](members), image: nil, groupId: groupID, groupType: .closedGroup, adminIds: group.groupAdminIds)
         thread.setGroupModel(newGroupModel, with: transaction)
@@ -206,16 +214,22 @@ extension MessageSender {
         let updateInfo = group.getInfoStringAboutUpdate(to: newGroupModel)
         let infoMessage = TSInfoMessage(timestamp: NSDate.ows_millisecondTimeStamp(), in: thread, messageType: .groupUpdate, customMessage: updateInfo)
         infoMessage.save(with: transaction)
+        // Return
+        return promise
+    }
+    
+    @objc(leaveClosedGroupWithPublicKey:using:)
+    public static func objc_leave(_ groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) -> AnyPromise {
+        return AnyPromise.from(leave(groupPublicKey, using: transaction))
     }
     
-    @objc(leaveClosedGroupWithPublicKey:using:error:)
+    public static func leave(_ groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) -> Promise<Void> {
-    public static func leave(_ groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) throws {
         // Get the group, check preconditions & prepare
         let groupID = LKGroupUtilities.getEncodedClosedGroupIDAsData(groupPublicKey)
         let threadID = TSGroupThread.threadId(fromGroupId: groupID)
         guard let thread = TSGroupThread.fetch(uniqueId: threadID, transaction: transaction) else {
             SNLog("Can't leave nonexistent closed group.")
-            throw Error.noThread
+            return Promise(error: Error.noThread)
         }
         let group = thread.groupModel
         let userPublicKey = getUserHexEncodedPublicKey()
@@ -224,14 +238,14 @@ extension MessageSender {
         let admins: Set<String> = isCurrentUserAdmin ? [] : Set(group.groupAdminIds)
         // Send the update to the group
         let closedGroupControlMessage = ClosedGroupControlMessage(kind: .memberLeft)
-        let _ = MessageSender.sendNonDurably(closedGroupControlMessage, in: thread, using: transaction).done {
+        let promise = MessageSender.sendNonDurably(closedGroupControlMessage, in: thread, using: transaction).done {
             SNMessagingKitConfiguration.shared.storage.write { transaction in
                 // Remove the group from the database and unsubscribe from PNs
                 Storage.shared.removeAllClosedGroupEncryptionKeyPairs(for: groupPublicKey, using: transaction)
                 Storage.shared.removeClosedGroupPublicKey(groupPublicKey, using: transaction)
                 let _ = PushNotificationAPI.performOperation(.unsubscribe, for: groupPublicKey, publicKey: userPublicKey)
             }
-        }
+        }.map { _ in }
         // Update the group
         let newGroupModel = TSGroupModel(title: group.groupName, memberIds: [String](members), image: nil, groupId: groupID, groupType: .closedGroup, adminIds: [String](admins))
         thread.setGroupModel(newGroupModel, with: transaction)
@@ -239,8 +253,11 @@ extension MessageSender {
         let updateInfo = group.getInfoStringAboutUpdate(to: newGroupModel)
         let infoMessage = TSInfoMessage(timestamp: NSDate.ows_millisecondTimeStamp(), in: thread, messageType: .groupUpdate, customMessage: updateInfo)
         infoMessage.save(with: transaction)
+        // Return
+        return promise
     }
     
+    /*
     public static func requestEncryptionKeyPair(for groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) throws {
         #if DEBUG
         preconditionFailure("Shouldn't currently be in use.")
@@ -258,15 +275,16 @@ extension MessageSender {
         let closedGroupControlMessage = ClosedGroupControlMessage(kind: .encryptionKeyPairRequest)
         MessageSender.send(closedGroupControlMessage, in: thread, using: transaction)
     }
+     */
     
     public static func sendLatestEncryptionKeyPair(to publicKey: String, for groupPublicKey: String, using transaction: YapDatabaseReadWriteTransaction) {
         // Check that the user in question is part of the closed group
         let groupID = LKGroupUtilities.getEncodedClosedGroupIDAsData(groupPublicKey)
         let threadID = TSGroupThread.threadId(fromGroupId: groupID)
-        guard let thread = TSGroupThread.fetch(uniqueId: threadID, transaction: transaction) else {
+        guard let groupThread = TSGroupThread.fetch(uniqueId: threadID, transaction: transaction) else {
-            return SNLog("Couldn't find thread .")
+            return SNLog("Couldn't send key pair for nonexistent closed group.")
         }
-        let group = thread.groupModel
+        let group = groupThread.groupModel
         guard group.groupMemberIds.contains(publicKey) else {
             return SNLog("Refusing to send latest encryption key pair to non-member.")
         }