From b721794a51ea2a4412e137c3523acf760bbf6e86 Mon Sep 17 00:00:00 2001
From: Niels Andriesse <andriesseniels@gmail.com>
Date: Mon, 8 Feb 2021 09:37:39 +1100
Subject: [PATCH] Fix closed group update handling from before it was created

---
 .../Database/Storage+ClosedGroups.swift           | 14 ++++++++++++++
 .../MessageReceiver+Handling.swift                | 15 ++++++++++-----
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/SessionMessagingKit/Database/Storage+ClosedGroups.swift b/SessionMessagingKit/Database/Storage+ClosedGroups.swift
index cda71072d..8ec789b85 100644
--- a/SessionMessagingKit/Database/Storage+ClosedGroups.swift
+++ b/SessionMessagingKit/Database/Storage+ClosedGroups.swift
@@ -9,6 +9,8 @@ extension Storage {
     }
 
     private static let closedGroupPublicKeyCollection = "SNClosedGroupPublicKeyCollection"
+    
+    private static let closedGroupFormationTimestampCollection = "SNClosedGroupFormationTimestampCollection"
 
     public func getClosedGroupEncryptionKeyPairs(for groupPublicKey: String) -> [ECKeyPair] {
         let collection = Storage.getClosedGroupEncryptionKeyPairCollection(for: groupPublicKey)
@@ -45,6 +47,18 @@ extension Storage {
         (transaction as! YapDatabaseReadWriteTransaction).removeObject(forKey: groupPublicKey, inCollection: Storage.closedGroupPublicKeyCollection)
     }
     
+    public func getClosedGroupFormationTimestamp(for groupPublicKey: String) -> UInt64? {
+        var result: UInt64?
+        Storage.read { transaction in
+            result = transaction.object(forKey: groupPublicKey, inCollection: Storage.closedGroupFormationTimestampCollection) as? UInt64
+        }
+        return result
+    }
+    
+    public func setClosedGroupFormationTimestamp(to timestamp: UInt64, for groupPublicKey: String, using transaction: Any) {
+        (transaction as! YapDatabaseReadWriteTransaction).setObject(timestamp, forKey: groupPublicKey, inCollection: Storage.closedGroupFormationTimestampCollection)
+    }
+    
     
     
     // MARK: - Ratchets
diff --git a/SessionMessagingKit/Sending & Receiving/MessageReceiver+Handling.swift b/SessionMessagingKit/Sending & Receiving/MessageReceiver+Handling.swift
index 7e8125810..cfbb6b3b6 100644
--- a/SessionMessagingKit/Sending & Receiving/MessageReceiver+Handling.swift	
+++ b/SessionMessagingKit/Sending & Receiving/MessageReceiver+Handling.swift	
@@ -150,7 +150,7 @@ extension MessageReceiver {
         for closedGroup in message.closedGroups {
             guard !allClosedGroupPublicKeys.contains(closedGroup.publicKey) else { continue }
             handleNewClosedGroup(groupPublicKey: closedGroup.publicKey, name: closedGroup.name, encryptionKeyPair: closedGroup.encryptionKeyPair,
-                members: [String](closedGroup.members), admins: [String](closedGroup.admins), using: transaction)
+                members: [String](closedGroup.members), admins: [String](closedGroup.admins), messageSentTimestamp: message.sentTimestamp!, using: transaction)
         }
         let allOpenGroups = Set(storage.getAllUserOpenGroups().keys)
         for openGroupURL in message.openGroups {
@@ -262,10 +262,11 @@ extension MessageReceiver {
         let groupPublicKey = publicKeyAsData.toHexString()
         let members = membersAsData.map { $0.toHexString() }
         let admins = adminsAsData.map { $0.toHexString() }
-        handleNewClosedGroup(groupPublicKey: groupPublicKey, name: name, encryptionKeyPair: encryptionKeyPair, members: members, admins: admins, using: transaction)
+        handleNewClosedGroup(groupPublicKey: groupPublicKey, name: name, encryptionKeyPair: encryptionKeyPair,
+            members: members, admins: admins, messageSentTimestamp: message.sentTimestamp!, using: transaction)
     }
 
-    private static func handleNewClosedGroup(groupPublicKey: String, name: String, encryptionKeyPair: ECKeyPair, members: [String], admins: [String], using transaction: Any) {
+    private static func handleNewClosedGroup(groupPublicKey: String, name: String, encryptionKeyPair: ECKeyPair, members: [String], admins: [String], messageSentTimestamp: UInt64, using transaction: Any) {
         let transaction = transaction as! YapDatabaseReadWriteTransaction
         // Create the group
         let groupID = LKGroupUtilities.getEncodedClosedGroupIDAsData(groupPublicKey)
@@ -282,6 +283,8 @@ extension MessageReceiver {
         Storage.shared.addClosedGroupPublicKey(groupPublicKey, using: transaction)
         // Store the key pair
         Storage.shared.addClosedGroupEncryptionKeyPair(encryptionKeyPair, for: groupPublicKey, using: transaction)
+        // Store the formation timestamp
+        Storage.shared.setClosedGroupFormationTimestamp(to: messageSentTimestamp, for: groupPublicKey, using: transaction)
         // Notify the PN server
         let _ = PushNotificationAPI.performOperation(.subscribe, for: groupPublicKey, publicKey: getUserHexEncodedPublicKey())
         // Notify the user
@@ -459,8 +462,10 @@ extension MessageReceiver {
         }
         let group = thread.groupModel
         // Check that the message isn't from before the group was created
-        guard Double(message.sentTimestamp!) > thread.creationDate.timeIntervalSince1970 * 1000 else {
-            return SNLog("Ignoring closed group update from before thread was created.")
+        if let formationTimestamp = Storage.shared.getClosedGroupFormationTimestamp(for: groupPublicKey) {
+            guard message.sentTimestamp! > formationTimestamp else {
+                return SNLog("Ignoring closed group update from before thread was created.")
+            }
         }
         // Check that the sender is a member of the group
         guard Set(group.groupMemberIds).contains(message.sender!) else {