core: do not create decryption error chat items for earlier messages (#2189)

* core: do not create decryption error chat items for earlier messages

* do not report earlier error, mobile items, fix tests

apps/android/app/src/main/java/chat/simplex/app/model/ChatModel.kt

@@ -1466,10 +1466,10 @@ data class ChatItem (
         file = null
       )
 
-    fun invalidJSON(json: String): ChatItem =
+    fun invalidJSON(chatDir: CIDirection?, meta: CIMeta?, json: String): ChatItem =
       ChatItem(
-        chatDir = CIDirection.DirectSnd(),
+        chatDir = chatDir ?: CIDirection.DirectSnd(),
-        meta = CIMeta.invalidJSON(),
+        meta = meta ?: CIMeta.invalidJSON(),
         content = CIContent.InvalidJSON(json),
         quotedItem = null,
         file = null
@@ -1681,13 +1681,11 @@ sealed class CIContent: ItemContent {
 @Serializable
 enum class MsgDecryptError {
   @SerialName("ratchetHeader") RatchetHeader,
-  @SerialName("earlier") Earlier,
   @SerialName("tooManySkipped") TooManySkipped;
 
   val text: String get() = when (this) {
-    RatchetHeader -> generalGetString(R.string.decryption_error_permanent)
+    RatchetHeader -> generalGetString(R.string.decryption_error)
-    Earlier -> generalGetString(R.string.decryption_error)
+    TooManySkipped -> generalGetString(R.string.decryption_error)
-    TooManySkipped -> generalGetString(R.string.decryption_error_permanent)
   }
 }
 

apps/android/app/src/main/java/chat/simplex/app/model/SimpleXAPI.kt

@@ -3011,9 +3011,15 @@ private fun parseChatData(chat: JsonElement): Chat {
     ?: ChatInfo.InvalidJSON(json.encodeToString(chat.jsonObject["chatInfo"]))
   val chatStats = decodeObject(Chat.ChatStats.serializer(), chat.jsonObject["chatStats"])!!
   val chatItems: List<ChatItem> = chat.jsonObject["chatItems"]!!.jsonArray.map {
-    decodeObject(ChatItem.serializer(), it) ?: ChatItem.invalidJSON(json.encodeToString(it))
+    decodeObject(ChatItem.serializer(), it) ?: parseChatItem(it)
   }
- return Chat(chatInfo, chatItems, chatStats)
+  return Chat(chatInfo, chatItems, chatStats)
+}
+
+private fun parseChatItem(j: JsonElement): ChatItem {
+  val chatDir: CIDirection? = decodeObject(CIDirection.serializer(), j.jsonObject["chatDir"])
+  val meta: CIMeta? = decodeObject(CIMeta.serializer(), j.jsonObject["meta"])
+  return ChatItem.invalidJSON(chatDir, meta, json.encodeToString(j))
 }
 
 private fun <T> decodeObject(deserializer: DeserializationStrategy<T>, obj: JsonElement?): T? =

apps/android/app/src/main/java/chat/simplex/app/views/chat/item/CIRcvDecryptionError.kt

@@ -15,8 +15,6 @@ fun CIRcvDecryptionError(msgDecryptError: MsgDecryptError, msgCount: UInt, ci: C
         MsgDecryptError.RatchetHeader -> String.format(generalGetString(R.string.alert_text_decryption_error_header), msgCount.toLong()) + "\n" +
             generalGetString(R.string.alert_text_fragment_encryption_out_of_sync_old_database) + "\n" +
             generalGetString(R.string.alert_text_fragment_permanent_error_reconnect)
-        MsgDecryptError.Earlier -> String.format(generalGetString(R.string.alert_text_decryption_error_earlier), msgCount.toLong()) + "\n" +
-            generalGetString(R.string.alert_text_fragment_encryption_out_of_sync_old_database)
         MsgDecryptError.TooManySkipped -> String.format(generalGetString(R.string.alert_text_decryption_error_too_many_skipped), msgCount.toLong()) + "\n" +
             generalGetString(R.string.alert_text_fragment_encryption_out_of_sync_old_database) + "\n" +
             generalGetString(R.string.alert_text_fragment_permanent_error_reconnect)

apps/android/app/src/main/res/values/strings.xml

@@ -32,7 +32,6 @@
   <string name="moderated_description">moderated</string>
   <string name="invalid_chat">invalid chat</string>
   <string name="invalid_data">invalid data</string>
-  <string name="decryption_error_permanent">Permanent decryption error</string>
   <string name="decryption_error">Decryption error</string>
 
   <!-- PendingContactConnection - ChatModel.kt -->
@@ -749,7 +748,6 @@
   <string name="alert_title_msg_bad_id">Bad message ID</string>
   <string name="alert_text_msg_bad_id">The ID of the next message is incorrect (less or equal to the previous).\nIt can happen because of some bug or when the connection is compromised.</string>
   <string name="alert_text_decryption_error_header"><xliff:g id="message count" example="1">%1$d</xliff:g> messages failed to decrypt.</string>
-  <string name="alert_text_decryption_error_earlier"><xliff:g id="message count" example="1">%1$d</xliff:g> messages failed to decrypt and won\'t be shown.</string>
   <string name="alert_text_decryption_error_too_many_skipped"><xliff:g id="message count" example="1">%1$d</xliff:g> messages skipped.</string>
   <string name="alert_text_fragment_encryption_out_of_sync_old_database">It can happen when you or your connection used the old database backup.</string>
   <string name="alert_text_fragment_permanent_error_reconnect">This error is permanent for this connection, please re-connect.</string>

apps/ios/Shared/Views/Chat/ChatItem/CIRcvDecryptionError.swift

@@ -25,8 +25,6 @@ struct CIRcvDecryptionError: View {
             switch msgDecryptError {
             case .ratchetHeader:
                 message = Text("\(msgCount) messages failed to decrypt.") + Text("\n") + why + Text("\n") + permanent
-            case .earlier:
-                message = Text("\(msgCount) messages failed to decrypt and won't be shown.") + Text("\n") + why
             case .tooManySkipped:
                 message = Text("\(msgCount) messages skipped.") + Text("\n") + why + Text("\n") + permanent
             }

apps/ios/SimpleXChat/API.swift

@@ -174,7 +174,11 @@ func parseChatData(_ jChat: Any) throws -> ChatData {
         if let ci: ChatItem = try? decodeObject(jCI) {
             return ci
         }
-        return ChatItem.invalidJSON(prettyJSON(jCI) ?? "")
+        return ChatItem.invalidJSON(
+            chatDir: decodeProperty(jCI, "chatDir"),
+            meta: decodeProperty(jCI, "meta"),
+            json: prettyJSON(jCI) ?? ""
+        )
     }
     return ChatData(chatInfo: chatInfo, chatItems: chatItems, chatStats: chatStats)
 }
@@ -183,6 +187,13 @@ func decodeObject<T: Decodable>(_ obj: Any) throws -> T {
     try jsonDecoder.decode(T.self, from: JSONSerialization.data(withJSONObject: obj))
 }
 
+func decodeProperty<T: Decodable>(_ obj: Any, _ prop: NSString) -> T? {
+    if let jProp = (obj as? NSDictionary)?[prop] {
+        return try? decodeObject(jProp)
+    }
+    return nil
+}
+
 func prettyJSON(_ obj: Any) -> String? {
     if let d = try? JSONSerialization.data(withJSONObject: obj, options: .prettyPrinted) {
         return String(decoding: d, as: UTF8.self)

apps/ios/SimpleXChat/ChatTypes.swift

@@ -1943,10 +1943,10 @@ public struct ChatItem: Identifiable, Decodable {
         return item
     }
 
-    public static func invalidJSON(_ json: String) -> ChatItem {
+    public static func invalidJSON(chatDir: CIDirection?, meta: CIMeta?, json: String) -> ChatItem {
         ChatItem(
-            chatDir: CIDirection.directSnd,
+            chatDir: chatDir ?? .directSnd,
-            meta: CIMeta.invalidJSON,
+            meta: meta ?? .invalidJSON,
             content: .invalidJSON(json: json),
             quotedItem: nil,
             file: nil
@@ -2178,13 +2178,11 @@ public enum CIContent: Decodable, ItemContent {
 
 public enum MsgDecryptError: String, Decodable {
     case ratchetHeader
-    case earlier
     case tooManySkipped
 
     var text: String {
         switch self {
         case .ratchetHeader: return NSLocalizedString("Permanent decryption error", comment: "message decrypt error item")
-        case .earlier: return NSLocalizedString("Decryption error", comment: "message decrypt error item")
         case .tooManySkipped: return NSLocalizedString("Permanent decryption error", comment: "message decrypt error item")
         }
     }

src/Simplex/Chat.hs

@@ -2820,19 +2820,19 @@ processAgentMessageConn user@User {userId} corrId agentConnId agentMessage = do
     agentMsgDecryptError :: AgentErrorType -> Maybe (MsgDecryptError, Word32)
     agentMsgDecryptError = \case
       AGENT (A_CRYPTO RATCHET_HEADER) -> Just (MDERatchetHeader, 1)
-      AGENT (A_CRYPTO (RATCHET_EARLIER n)) -> Just (MDEEarlier, n + 1) -- 1 is added to account for the message that has A_DUPLICATE error
       AGENT (A_CRYPTO (RATCHET_SKIPPED n)) -> Just (MDETooManySkipped, n)
       -- we are not treating this as decryption error, as in many cases it happens as the result of duplicate or redundant delivery,
       -- and we don't have a way to differentiate.
       -- we could store the hashes of past messages in the agent, or delaying message deletion after ACK
       -- A_DUPLICATE -> Nothing
+      -- earlier messages may be received in case of redundant delivery, and do not necessarily indicate an error
+      -- AGENT (A_CRYPTO (RATCHET_EARLIER n)) -> Nothing
       _ -> Nothing
 
     mdeUpdatedCI :: (MsgDecryptError, Word32) -> CChatItem c -> Maybe (ChatItem c 'MDRcv, CIContent 'MDRcv)
     mdeUpdatedCI (mde', n') (CChatItem _ ci@ChatItem {content = CIRcvDecryptionError mde n})
       | mde == mde' = case mde of
         MDERatchetHeader -> r (n + n')
-        MDEEarlier -> r n -- the first error in a sequence has the largest number – it's the number of messages to receive to catch up, keeping it
         MDETooManySkipped -> r n' -- the numbers are not added as sequential MDETooManySkipped will have it incremented by 1
       | otherwise = Nothing
       where

src/Simplex/Chat/Messages.hs

@@ -735,10 +735,7 @@ data CIContent (d :: MsgDirection) where
 
 deriving instance Show (CIContent d)
 
-data MsgDecryptError
+data MsgDecryptError = MDERatchetHeader | MDETooManySkipped
-  = MDERatchetHeader
-  | MDEEarlier
-  | MDETooManySkipped
   deriving (Eq, Show, Generic)
 
 instance ToJSON MsgDecryptError where
@@ -954,7 +951,6 @@ msgDecryptErrorText err n =
   where
     errName = case err of
       MDERatchetHeader -> "header"
-      MDEEarlier -> "earlier message"
       MDETooManySkipped -> "too many skipped messages"
 
 msgDirToModeratedContent_ :: SMsgDirection d -> CIContent d

tests/ChatTests/Groups.hs

@@ -2055,7 +2055,6 @@ testGroupMsgDecryptError tmp =
         bob #> "#team 4"
         alice <# "#team bob> 4"
         bob #> "#team 5"
-        cath <# "#team bob> decryption error, possibly due to the device change (earlier message, 2 messages)"
         cath <# "#team bob> incorrect message hash"
         [alice, cath] *<# "#team bob> 5"
         bob #> "#team 6"