core: ratchet synchronization (#2653)

2026-08-05 10:49:47 +00:00 · 2023-07-05 19:44:21 +04:00
parent c329bf4ea1
commit ae17566a94
10 changed files with 411 additions and 132 deletions
@@ -1134,6 +1134,19 @@ processChatCommand = \case
        connectionStats <- withAgent $ \a -> abortConnectionSwitch a connId
        pure $ CRGroupMemberSwitchAborted user g m connectionStats
      _ -> throwChatError CEGroupMemberNotActive
+  APISyncContactRatchet contactId force -> withUser $ \user -> do
+    ct <- withStore $ \db -> getContact db user contactId
+    cStats@ConnectionStats {ratchetSyncState = rss} <- withAgent $ \a -> synchronizeRatchet a (contactConnId ct) force
+    createInternalChatItem user (CDDirectSnd ct) (CISndConnEvent $ SCERatchetSync rss Nothing) Nothing
+    pure $ CRContactRatchetSyncStarted user ct cStats
+  APISyncGroupMemberRatchet gId gMemberId force -> withUser $ \user -> do
+    (g, m) <- withStore $ \db -> (,) <$> getGroupInfo db user gId <*> getGroupMember db user gId gMemberId
+    case memberConnId m of
+      Just connId -> do
+        cStats@ConnectionStats {ratchetSyncState = rss} <- withAgent $ \a -> synchronizeRatchet a connId force
+        createInternalChatItem user (CDGroupSnd g) (CISndConnEvent . SCERatchetSync rss . Just $ groupMemberRef m) Nothing
+        pure $ CRGroupMemberRatchetSyncStarted user g m cStats
+      _ -> throwChatError CEGroupMemberNotActive
  APIGetContactCode contactId -> withUser $ \user -> do
    ct@Contact {activeConn = conn@Connection {connId}} <- withStore $ \db -> getContact db user contactId
    code <- getConnectionCode (contactConnId ct)
@@ -1196,6 +1209,8 @@ processChatCommand = \case
  SwitchGroupMember gName mName -> withMemberName gName mName APISwitchGroupMember
  AbortSwitchContact cName -> withContactName cName APIAbortSwitchContact
  AbortSwitchGroupMember gName mName -> withMemberName gName mName APIAbortSwitchGroupMember
+  SyncContactRatchet cName force -> withContactName cName $ \ctId -> APISyncContactRatchet ctId force
+  SyncGroupMemberRatchet gName mName force -> withMemberName gName mName $ \gId mId -> APISyncGroupMemberRatchet gId mId force
  GetContactCode cName -> withContactName cName APIGetContactCode
  GetGroupMemberCode gName mName -> withMemberName gName mName APIGetGroupMemberCode
  VerifyContact cName code -> withContactName cName (`APIVerifyContact` code)
@@ -2716,7 +2731,7 @@ processAgentMessageConn user@User {userId} corrId agentConnId agentMessage = do
      _ -> Nothing

    processDirectMessage :: ACommand 'Agent e -> ConnectionEntity -> Connection -> Maybe Contact -> m ()
-    processDirectMessage agentMsg connEntity conn@Connection {connId, viaUserContactLink, groupLinkId, customUserProfileId} = \case
+    processDirectMessage agentMsg connEntity conn@Connection {connId, viaUserContactLink, groupLinkId, customUserProfileId, connectionCode} = \case
      Nothing -> case agentMsg of
        CONF confId _ connInfo -> do
          -- [incognito] send saved profile
@@ -2849,6 +2864,36 @@ processAgentMessageConn user@User {userId} corrId agentConnId agentMessage = do
          when (phase `elem` [SPStarted, SPCompleted]) $ case qd of
            QDRcv -> createInternalChatItem user (CDDirectSnd ct) (CISndConnEvent $ SCESwitchQueue phase Nothing) Nothing
            QDSnd -> createInternalChatItem user (CDDirectRcv ct) (CIRcvConnEvent $ RCESwitchQueue phase) Nothing
+        RSYNC rss cryptoErr_ cStats ->
+          case (rss, connectionCode, cryptoErr_) of
+            (RSRequired, _, Just cryptoErr) -> processErr cryptoErr
+            (RSAllowed, _, Just cryptoErr) -> processErr cryptoErr
+            (RSAgreed, Just _, _) -> do
+              withStore' $ \db -> setConnectionVerified db user connId Nothing
+              let ct' = ct {activeConn = conn {connectionCode = Nothing}} :: Contact
+              ratchetSyncEventItem ct'
+              toView $ CRContactVerificationReset user ct'
+              createInternalChatItem user (CDDirectRcv ct') (CIRcvConnEvent RCEVerificationCodeReset) Nothing
+            _ -> ratchetSyncEventItem ct
+          where
+            processErr cryptoErr = do
+              let e@(mde, n) = agentMsgDecryptError cryptoErr
+              ci_ <- withStore $ \db ->
+                getDirectChatItemsLast db user contactId 1 ""
+                  >>= liftIO
+                    . mapM (\(ci, content') -> updateDirectChatItem' db user contactId ci content' False Nothing)
+                    . (mdeUpdatedCI e <=< headMaybe)
+              case ci_ of
+                Just ci -> toView $ CRChatItemUpdated user (AChatItem SCTDirect SMDRcv (DirectChat ct) ci)
+                _ -> do
+                  toView $ CRContactRatchetSync user ct (RatchetSyncProgress rss cStats)
+                  createInternalChatItem user (CDDirectRcv ct) (CIRcvDecryptionError mde n) Nothing
+            headMaybe = \case
+              x : _ -> Just x
+              _ -> Nothing
+            ratchetSyncEventItem ct' = do
+              toView $ CRContactRatchetSync user ct' (RatchetSyncProgress rss cStats)
+              createInternalChatItem user (CDDirectRcv ct') (CIRcvConnEvent $ RCERatchetSync rss) Nothing
        OK ->
          -- [async agent commands] continuation on receiving OK
          withCompletedCommand conn agentMsg $ \CommandData {cmdFunction, cmdId} ->
@@ -2863,24 +2908,11 @@ processAgentMessageConn user@User {userId} corrId agentConnId agentMessage = do
        ERR err -> do
          toView $ CRChatError (Just user) (ChatErrorAgent err $ Just connEntity)
          when (corrId /= "") $ withCompletedCommand conn agentMsg $ \_cmdData -> pure ()
-          forM_ (agentMsgDecryptError err) $ \e@(mde, n) -> do
-            ci_ <- withStore $ \db ->
-              getDirectChatItemsLast db user contactId 1 ""
-                >>= liftIO
-                  . mapM (\(ci, content') -> updateDirectChatItem' db user contactId ci content' False Nothing)
-                  . (mdeUpdatedCI e <=< headMaybe)
-            case ci_ of
-              Just ci -> toView $ CRChatItemUpdated user (AChatItem SCTDirect SMDRcv (DirectChat ct) ci)
-              _ -> createInternalChatItem user (CDDirectRcv ct) (CIRcvDecryptionError mde n) Nothing
-          where
-            headMaybe = \case
-              x : _ -> Just x
-              _ -> Nothing
        -- TODO add debugging output
        _ -> pure ()

    processGroupMessage :: ACommand 'Agent e -> ConnectionEntity -> Connection -> GroupInfo -> GroupMember -> m ()
-    processGroupMessage agentMsg connEntity conn@Connection {connId} gInfo@GroupInfo {groupId, localDisplayName = gName, groupProfile, membership, chatSettings} m = case agentMsg of
+    processGroupMessage agentMsg connEntity conn@Connection {connId, connectionCode} gInfo@GroupInfo {groupId, localDisplayName = gName, groupProfile, membership, chatSettings} m = case agentMsg of
      INV (ACR _ cReq) ->
        withCompletedCommand conn agentMsg $ \CommandData {cmdFunction} ->
          case cReq of
@@ -3028,6 +3060,33 @@ processAgentMessageConn user@User {userId} corrId agentConnId agentMessage = do
        when (phase `elem` [SPStarted, SPCompleted]) $ case qd of
          QDRcv -> createInternalChatItem user (CDGroupSnd gInfo) (CISndConnEvent . SCESwitchQueue phase . Just $ groupMemberRef m) Nothing
          QDSnd -> createInternalChatItem user (CDGroupRcv gInfo m) (CIRcvConnEvent $ RCESwitchQueue phase) Nothing
+      RSYNC rss cryptoErr_ cStats ->
+        case (rss, connectionCode, cryptoErr_) of
+          (RSRequired, _, Just cryptoErr) -> processErr cryptoErr
+          (RSAllowed, _, Just cryptoErr) -> processErr cryptoErr
+          (RSAgreed, Just _, _) -> do
+            withStore' $ \db -> setConnectionVerified db user connId Nothing
+            let m' = m {activeConn = Just (conn {connectionCode = Nothing} :: Connection)} :: GroupMember
+            ratchetSyncEventItem m'
+            toView $ CRGroupMemberVerificationReset user gInfo m'
+            createInternalChatItem user (CDGroupRcv gInfo m') (CIRcvConnEvent RCEVerificationCodeReset) Nothing
+          _ -> ratchetSyncEventItem m
+        where
+          processErr cryptoErr = do
+            let e@(mde, n) = agentMsgDecryptError cryptoErr
+            ci_ <- withStore $ \db ->
+              getGroupMemberChatItemLast db user groupId (groupMemberId' m)
+                >>= liftIO
+                  . mapM (\(ci, content') -> updateGroupChatItem db user groupId ci content' False Nothing)
+                  . mdeUpdatedCI e
+            case ci_ of
+              Just ci -> toView $ CRChatItemUpdated user (AChatItem SCTGroup SMDRcv (GroupChat gInfo) ci)
+              _ -> do
+                toView $ CRGroupMemberRatchetSync user gInfo m (RatchetSyncProgress rss cStats)
+                createInternalChatItem user (CDGroupRcv gInfo m) (CIRcvDecryptionError mde n) Nothing
+          ratchetSyncEventItem m' = do
+            toView $ CRGroupMemberRatchetSync user gInfo m' (RatchetSyncProgress rss cStats)
+            createInternalChatItem user (CDGroupRcv gInfo m') (CIRcvConnEvent $ RCERatchetSync rss) Nothing
      OK ->
        -- [async agent commands] continuation on receiving OK
        withCompletedCommand conn agentMsg $ \CommandData {cmdFunction, cmdId} ->
@@ -3038,35 +3097,24 @@ processAgentMessageConn user@User {userId} corrId agentConnId agentMessage = do
      ERR err -> do
        toView $ CRChatError (Just user) (ChatErrorAgent err $ Just connEntity)
        when (corrId /= "") $ withCompletedCommand conn agentMsg $ \_cmdData -> pure ()
-        forM_ (agentMsgDecryptError err) $ \e@(mde, n) -> do
-          ci_ <- withStore $ \db ->
-            getGroupMemberChatItemLast db user groupId (groupMemberId' m)
-              >>= liftIO
-                . mapM (\(ci, content') -> updateGroupChatItem db user groupId ci content' False Nothing)
-                . mdeUpdatedCI e
-          case ci_ of
-            Just ci -> toView $ CRChatItemUpdated user (AChatItem SCTGroup SMDRcv (GroupChat gInfo) ci)
-            _ -> createInternalChatItem user (CDGroupRcv gInfo m) (CIRcvDecryptionError mde n) Nothing
      -- TODO add debugging output
      _ -> pure ()

-    agentMsgDecryptError :: AgentErrorType -> Maybe (MsgDecryptError, Word32)
+    agentMsgDecryptError :: AgentCryptoError -> (MsgDecryptError, Word32)
    agentMsgDecryptError = \case
-      AGENT (A_CRYPTO RATCHET_HEADER) -> Just (MDERatchetHeader, 1)
-      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
+      DECRYPT_AES -> (MDEOther, 1)
+      DECRYPT_CB -> (MDEOther, 1)
+      RATCHET_HEADER -> (MDERatchetHeader, 1)
+      RATCHET_EARLIER _ -> (MDERatchetEarlier, 1)
+      RATCHET_SKIPPED n -> (MDETooManySkipped, n)

    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')
        MDETooManySkipped -> r n' -- the numbers are not added as sequential MDETooManySkipped will have it incremented by 1
+        MDERatchetEarlier -> r (n + n')
+        MDEOther -> r (n + n')
      | otherwise = Nothing
      where
        r n'' = Just (ci, CIRcvDecryptionError mde n'')
@@ -4919,10 +4967,14 @@ chatCommandP =
      "/_switch @" *> (APISwitchContact <$> A.decimal),
      "/_abort switch #" *> (APIAbortSwitchGroupMember <$> A.decimal <* A.space <*> A.decimal),
      "/_abort switch @" *> (APIAbortSwitchContact <$> A.decimal),
+      "/_sync #" *> (APISyncGroupMemberRatchet <$> A.decimal <* A.space <*> A.decimal <*> (" force=on" $> True <|> pure False)),
+      "/_sync @" *> (APISyncContactRatchet <$> A.decimal <*> (" force=on" $> True <|> pure False)),
      "/switch #" *> (SwitchGroupMember <$> displayName <* A.space <* char_ '@' <*> displayName),
      "/switch " *> char_ '@' *> (SwitchContact <$> displayName),
      "/abort switch #" *> (AbortSwitchGroupMember <$> displayName <* A.space <* char_ '@' <*> displayName),
      "/abort switch " *> char_ '@' *> (AbortSwitchContact <$> displayName),
+      "/sync #" *> (SyncGroupMemberRatchet <$> displayName <* A.space <* char_ '@' <*> displayName <*> (" force=on" $> True <|> pure False)),
+      "/sync " *> char_ '@' *> (SyncContactRatchet <$> displayName <*> (" force=on" $> True <|> pure False)),
      "/_get code @" *> (APIGetContactCode <$> A.decimal),
      "/_get code #" *> (APIGetGroupMemberCode <$> A.decimal <* A.space <*> A.decimal),
      "/_verify code @" *> (APIVerifyContact <$> A.decimal <*> optional (A.space *> textP)),
@@ -287,6 +287,8 @@ data ChatCommand
  | APISwitchGroupMember GroupId GroupMemberId
  | APIAbortSwitchContact ContactId
  | APIAbortSwitchGroupMember GroupId GroupMemberId
+  | APISyncContactRatchet ContactId Bool
+  | APISyncGroupMemberRatchet GroupId GroupMemberId Bool
  | APIGetContactCode ContactId
  | APIGetGroupMemberCode GroupId GroupMemberId
  | APIVerifyContact ContactId (Maybe Text)
@@ -300,6 +302,8 @@ data ChatCommand
  | SwitchGroupMember GroupName ContactName
  | AbortSwitchContact ContactName
  | AbortSwitchGroupMember GroupName ContactName
+  | SyncContactRatchet ContactName Bool
+  | SyncGroupMemberRatchet GroupName ContactName Bool
  | GetContactCode ContactName
  | GetGroupMemberCode GroupName ContactName
  | VerifyContact ContactName (Maybe Text)
@@ -415,6 +419,12 @@ data ChatResponse
  | CRGroupMemberSwitchAborted {user :: User, groupInfo :: GroupInfo, member :: GroupMember, connectionStats :: ConnectionStats}
  | CRContactSwitch {user :: User, contact :: Contact, switchProgress :: SwitchProgress}
  | CRGroupMemberSwitch {user :: User, groupInfo :: GroupInfo, member :: GroupMember, switchProgress :: SwitchProgress}
+  | CRContactRatchetSyncStarted {user :: User, contact :: Contact, connectionStats :: ConnectionStats}
+  | CRGroupMemberRatchetSyncStarted {user :: User, groupInfo :: GroupInfo, member :: GroupMember, connectionStats :: ConnectionStats}
+  | CRContactRatchetSync {user :: User, contact :: Contact, ratchetSyncProgress :: RatchetSyncProgress}
+  | CRGroupMemberRatchetSync {user :: User, groupInfo :: GroupInfo, member :: GroupMember, ratchetSyncProgress :: RatchetSyncProgress}
+  | CRContactVerificationReset {user :: User, contact :: Contact}
+  | CRGroupMemberVerificationReset {user :: User, groupInfo :: GroupInfo, member :: GroupMember}
  | CRContactCode {user :: User, contact :: Contact, connectionCode :: Text}
  | CRGroupMemberCode {user :: User, groupInfo :: GroupInfo, member :: GroupMember, connectionCode :: Text}
  | CRConnectionVerified {user :: User, verified :: Bool, expectedCode :: Text}
@@ -719,6 +729,14 @@ data SwitchProgress = SwitchProgress

 instance ToJSON SwitchProgress where toEncoding = J.genericToEncoding J.defaultOptions

+data RatchetSyncProgress = RatchetSyncProgress
+  { ratchetSyncStatus :: RatchetSyncState,
+    connectionStats :: ConnectionStats
+  }
+  deriving (Show, Generic)
+
+instance ToJSON RatchetSyncProgress where toEncoding = J.genericToEncoding J.defaultOptions
+
 data ParsedServerAddress = ParsedServerAddress
  { serverAddress :: Maybe ServerAddress,
    parseError :: String
@@ -29,7 +29,7 @@ import Database.SQLite.Simple.ToField (ToField (..))
 import GHC.Generics (Generic)
 import Simplex.Chat.Protocol
 import Simplex.Chat.Types
-import Simplex.Messaging.Agent.Protocol (MsgErrorType (..), SwitchPhase (..))
+import Simplex.Messaging.Agent.Protocol (MsgErrorType (..), RatchetSyncState (..), SwitchPhase (..))
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Parsers (dropPrefix, enumJSON, fstToLower, singleFieldJSON, sumTypeJSON)
 import Simplex.Messaging.Util (safeDecodeUtf8, tshow)
@@ -157,7 +157,7 @@ ciMsgContent = \case
  CIRcvMsgContent mc -> Just mc
  _ -> Nothing

-data MsgDecryptError = MDERatchetHeader | MDETooManySkipped
+data MsgDecryptError = MDERatchetHeader | MDETooManySkipped | MDERatchetEarlier | MDEOther
  deriving (Eq, Show, Generic)

 instance ToJSON MsgDecryptError where
@@ -253,10 +253,15 @@ instance ToJSON DBSndGroupEvent where
  toJSON (SGE v) = J.genericToJSON (singleFieldJSON $ dropPrefix "SGE") v
  toEncoding (SGE v) = J.genericToEncoding (singleFieldJSON $ dropPrefix "SGE") v

-data RcvConnEvent = RCESwitchQueue {phase :: SwitchPhase}
+data RcvConnEvent
+  = RCESwitchQueue {phase :: SwitchPhase}
+  | RCERatchetSync {syncStatus :: RatchetSyncState}
+  | RCEVerificationCodeReset
  deriving (Show, Generic)

-data SndConnEvent = SCESwitchQueue {phase :: SwitchPhase, member :: Maybe GroupMemberRef}
+data SndConnEvent
+  = SCESwitchQueue {phase :: SwitchPhase, member :: Maybe GroupMemberRef}
+  | SCERatchetSync {syncStatus :: RatchetSyncState, member :: Maybe GroupMemberRef}
  deriving (Show, Generic)

 instance FromJSON RcvConnEvent where
@@ -387,6 +392,16 @@ rcvConnEventToText = \case
    SPConfirmed -> "confirmed changing address for you..."
    SPSecured -> "secured new address for you..."
    SPCompleted -> "changed address for you"
+  RCERatchetSync syncStatus -> ratchetSyncStatusToText syncStatus
+  RCEVerificationCodeReset -> "security code changed"
+
+ratchetSyncStatusToText :: RatchetSyncState -> Text
+ratchetSyncStatusToText = \case
+  RSOk -> "connection synchronized"
+  RSAllowed -> "decryption error (connection may be out of sync), synchronization allowed"
+  RSRequired -> "decryption error (connection out of sync), synchronization required"
+  RSStarted -> "connection synchronization started"
+  RSAgreed -> "connection synchronization agreed"

 sndConnEventToText :: SndConnEvent -> Text
 sndConnEventToText = \case
@@ -395,6 +410,7 @@ sndConnEventToText = \case
    SPConfirmed -> "confirmed changing address" <> forMember m <> "..."
    SPSecured -> "secured new address" <> forMember m <> "..."
    SPCompleted -> "you changed address" <> forMember m
+  SCERatchetSync syncStatus m -> ratchetSyncStatusToText syncStatus <> forMember m
  where
    forMember member_ =
      maybe "" (\GroupMemberRef {profile = Profile {displayName}} -> " for " <> displayName) member_
@@ -413,11 +429,16 @@ msgIntegrityError = \case

 msgDecryptErrorText :: MsgDecryptError -> Word32 -> Text
 msgDecryptErrorText err n =
-  "decryption error, possibly due to the device change (" <> errName <> if n == 1 then ")" else ", " <> tshow n <> " messages)"
+  "decryption error, possibly due to the device change"
+    <> maybe "" (\ed -> " (" <> ed <> ")") errDesc
  where
-    errName = case err of
-      MDERatchetHeader -> "header"
-      MDETooManySkipped -> "too many skipped messages"
+    errDesc = case err of
+      MDERatchetHeader -> Just $ "header" <> counter
+      MDETooManySkipped -> Just $ "too many skipped messages" <> counter
+      MDERatchetEarlier -> Just $ "earlier message" <> counter
+      MDEOther -> counter_
+    counter_ = if n == 1 then Nothing else Just $ tshow n <> " messages"
+    counter = maybe "" (", " <>) counter_

 msgDirToModeratedContent_ :: SMsgDirection d -> CIContent d
 msgDirToModeratedContent_ = \case
@@ -627,9 +627,6 @@ getContactConnections db userId Contact {contactId} =
    connections [] = throwError $ SEContactNotFound contactId
    connections rows = pure $ map toConnection rows

-
-
-
 getConnectionById :: DB.Connection -> User -> Int64 -> ExceptT StoreError IO Connection
 getConnectionById db User {userId} connId = ExceptT $ do
  firstRow toConnection (SEConnectionNotFoundById connId) $
@@ -28,7 +28,6 @@ import Data.Time (LocalTime (..), TimeOfDay (..), TimeZone (..), utcToLocalTime)
 import Data.Time.Calendar (addDays)
 import Data.Time.Clock (UTCTime)
 import Data.Time.Format (defaultTimeLocale, formatTime)
-import Data.Word (Word32)
 import GHC.Generics (Generic)
 import qualified Network.HTTP.Types as Q
 import Numeric (showFFloat)
@@ -86,6 +85,12 @@ responseToView user_ ChatConfig {logLevel, showReactions, testView} liveItems ts
  CRGroupMemberSwitchAborted {} -> ["switch aborted"]
  CRContactSwitch u ct progress -> ttyUser u $ viewContactSwitch ct progress
  CRGroupMemberSwitch u g m progress -> ttyUser u $ viewGroupMemberSwitch g m progress
+  CRContactRatchetSyncStarted {} -> ["connection synchronization started"]
+  CRGroupMemberRatchetSyncStarted {} -> ["connection synchronization started"]
+  CRContactRatchetSync u ct progress -> ttyUser u $ viewContactRatchetSync ct progress
+  CRGroupMemberRatchetSync u g m progress -> ttyUser u $ viewGroupMemberRatchetSync g m progress
+  CRContactVerificationReset u ct -> ttyUser u $ viewContactVerificationReset ct
+  CRGroupMemberVerificationReset u g m -> ttyUser u $ viewGroupMemberVerificationReset g m
  CRConnectionVerified u verified code -> ttyUser u [plain $ if verified then "connection verified" else "connection not verified, current code is " <> code]
  CRContactCode u ct code -> ttyUser u $ viewContactCode ct code testView
  CRGroupMemberCode u g m code -> ttyUser u $ viewGroupMemberCode g m code testView
@@ -385,7 +390,6 @@ viewChatItem chat ci@ChatItem {chatDir, meta = meta, content, quotedItem, file}
      CIDirectRcv -> case content of
        CIRcvMsgContent mc -> withRcvFile from $ rcvMsg from quote mc
        CIRcvIntegrityError err -> viewRcvIntegrityError from err ts tz meta
-        CIRcvDecryptionError err n -> viewRcvDecryptionError from err n ts tz meta
        CIRcvGroupEvent {} -> showRcvItemProhibited from
        _ -> showRcvItem from
        where
@@ -402,7 +406,6 @@ viewChatItem chat ci@ChatItem {chatDir, meta = meta, content, quotedItem, file}
      CIGroupRcv m -> case content of
        CIRcvMsgContent mc -> withRcvFile from $ rcvMsg from quote mc
        CIRcvIntegrityError err -> viewRcvIntegrityError from err ts tz meta
-        CIRcvDecryptionError err n -> viewRcvDecryptionError from err n ts tz meta
        CIRcvGroupInvitation {} -> showRcvItemProhibited from
        CIRcvModerated {} -> receivedWithTime_ ts tz (ttyFromGroup g m) quote meta [plainContent content] False
        _ -> showRcvItem from
@@ -587,9 +590,6 @@ msgPreview = msgPlain . preview . msgContentText
 viewRcvIntegrityError :: StyledString -> MsgErrorType -> CurrentTime -> TimeZone -> CIMeta c 'MDRcv -> [StyledString]
 viewRcvIntegrityError from msgErr ts tz meta = receivedWithTime_ ts tz from [] meta (viewMsgIntegrityError msgErr) False

-viewRcvDecryptionError :: StyledString -> MsgDecryptError -> Word32 -> CurrentTime -> TimeZone -> CIMeta c 'MDRcv -> [StyledString]
-viewRcvDecryptionError from err n ts tz meta = receivedWithTime_ ts tz from [] meta [ttyError $ msgDecryptErrorText err n] False
-
 viewMsgIntegrityError :: MsgErrorType -> [StyledString]
 viewMsgIntegrityError err = [ttyError $ msgIntegrityError err]

@@ -968,6 +968,28 @@ viewGroupMemberSwitch g m (SwitchProgress qd phase _) = case qd of
  QDRcv -> [ttyGroup' g <> ": you " <> viewSwitchPhase phase <> " for " <> ttyMember m]
  QDSnd -> [ttyGroup' g <> ": " <> ttyMember m <> " " <> viewSwitchPhase phase <> " for you"]

+viewContactRatchetSync :: Contact -> RatchetSyncProgress -> [StyledString]
+viewContactRatchetSync ct@Contact {localDisplayName = c} RatchetSyncProgress {ratchetSyncStatus = rss} =
+  [ttyContact' ct <> ": " <> (plain . ratchetSyncStatusToText) rss]
+    <> help
+  where
+    help = ["use " <> highlight ("/sync " <> c) <> " to synchronize" | rss `elem` [RSAllowed, RSRequired]]
+
+viewGroupMemberRatchetSync :: GroupInfo -> GroupMember -> RatchetSyncProgress -> [StyledString]
+viewGroupMemberRatchetSync g m@GroupMember {localDisplayName = n} RatchetSyncProgress {ratchetSyncStatus = rss} =
+  [ttyGroup' g <> " " <> ttyMember m <> ": " <> (plain . ratchetSyncStatusToText) rss]
+    <> help
+  where
+    help = ["use " <> highlight ("/sync #" <> groupName' g <> " " <> n) <> " to synchronize" | rss `elem` [RSAllowed, RSRequired]]
+
+viewContactVerificationReset :: Contact -> [StyledString]
+viewContactVerificationReset ct =
+  [ttyContact' ct <> ": security code changed"]
+
+viewGroupMemberVerificationReset :: GroupInfo -> GroupMember -> [StyledString]
+viewGroupMemberVerificationReset g m =
+  [ttyGroup' g <> " " <> ttyMember m <> ": security code changed"]
+
 viewContactCode :: Contact -> Text -> Bool -> [StyledString]
 viewContactCode ct@Contact {localDisplayName = c} = viewSecurityCode (ttyContact' ct) ("/verify " <> c <> " <code from your contact>")