smp protocol: bind agreed version of forwarded command (#1915)

* smp protocol: bind agreed version of forwarded command

* refactor

* pass proxied relay version range via config

* simplify

* refactor

* packZipWith

---------

Co-authored-by: Evgeny @ SimpleX Chat <259188159+evgeny-simplex@users.noreply.github.com>

src/Simplex/Messaging/Client.hs

@@ -195,6 +195,7 @@ data PClient v err msg = PClient
     transportHost :: TransportHost,
     tcpConnectTimeout :: NetworkTimeout,
     tcpTimeout :: NetworkTimeout,
+    proxiedRelayVRange :: VersionRange v,
     sendPings :: TVar Bool,
     lastReceived :: TVar UTCTime,
     timeoutErrorCount :: TVar Int,
@@ -240,6 +241,7 @@ smpClientStub g sessionId thVersion thAuth = do
               transportHost = "localhost",
               tcpConnectTimeout,
               tcpTimeout,
+              proxiedRelayVRange = supportedClientSMPRelayVRange,
               sendPings,
               lastReceived,
               timeoutErrorCount,
@@ -477,6 +479,7 @@ data ProtocolClientConfig v = ProtocolClientConfig
     serviceCredentials :: Maybe ServiceCredentials,
     -- | client-server protocol version range
     serverVRange :: VersionRange v,
+    proxiedRelayVRange :: VersionRange v,
     -- | agree shared session secret (used in SMP proxy for additional encryption layer)
     agreeSecret :: Bool,
     -- | Whether connecting client is a proxy server. See comment in ClientHandshake
@@ -495,6 +498,7 @@ defaultClientConfig clientALPN useSNI serverVRange =
       clientALPN,
       serviceCredentials = Nothing,
       serverVRange,
+      proxiedRelayVRange = serverVRange,
       agreeSecret = False,
       proxyServer = False,
       useSNI
@@ -505,6 +509,7 @@ defaultSMPClientConfig :: ProtocolClientConfig SMPVersion
 defaultSMPClientConfig =
   (defaultClientConfig (Just alpnSupportedSMPHandshakes) False supportedClientSMPRelayVRange)
     { defaultTransport = (show defaultSMPPort, transport @TLS),
+      proxiedRelayVRange = supportedClientSMPRelayVRange,
       agreeSecret = True
     }
 {-# INLINE defaultSMPClientConfig #-}
@@ -568,7 +573,7 @@ type SMPTransportSession = TransportSession BrokerMsg
 -- A single queue can be used for multiple 'SMPClient' instances,
 -- as 'SMPServerTransmission' includes server information.
 getProtocolClient :: forall v err msg. Protocol v err msg => TVar ChaChaDRG -> NetworkRequestMode -> TransportSession msg -> ProtocolClientConfig v -> [HostName] -> Maybe (TBQueue (ServerTransmissionBatch v err msg)) -> UTCTime -> (ProtocolClient v err msg -> IO ()) -> IO (Either (ProtocolClientError err) (ProtocolClient v err msg))
-getProtocolClient g nm transportSession@(_, srv, _) cfg@ProtocolClientConfig {qSize, networkConfig, clientALPN, serviceCredentials, serverVRange, agreeSecret, proxyServer, useSNI} presetDomains msgQ proxySessTs disconnected = do
+getProtocolClient g nm transportSession@(_, srv, _) cfg@ProtocolClientConfig {qSize, networkConfig, clientALPN, serviceCredentials, serverVRange, proxiedRelayVRange, agreeSecret, proxyServer, useSNI} presetDomains msgQ proxySessTs disconnected = do
   case chooseTransportHost networkConfig (host srv) of
     Right useHost ->
       (getCurrentTime >>= mkProtocolClient useHost >>= runClient useTransport useHost)
@@ -593,6 +598,7 @@ getProtocolClient g nm transportSession@(_, srv, _) cfg@ProtocolClientConfig {qS
             transportHost,
             tcpConnectTimeout,
             tcpTimeout,
+            proxiedRelayVRange,
             sendPings,
             lastReceived,
             timeoutErrorCount,
@@ -1115,10 +1121,10 @@ deleteSMPQueues = okSMPCommands DEL
 -- send PRXY :: SMPServer -> Maybe BasicAuth -> Command Sender
 -- receives PKEY :: SessionId -> X.CertificateChain -> X.SignedExact X.PubKey -> BrokerMsg
 connectSMPProxiedRelay :: SMPClient -> NetworkRequestMode -> SMPServer -> Maybe BasicAuth -> ExceptT SMPClientError IO ProxiedRelay
-connectSMPProxiedRelay c@ProtocolClient {client_ = PClient {tcpConnectTimeout, tcpTimeout}} nm relayServ@ProtocolServer {port = relayPort, keyHash = C.KeyHash kh} proxyAuth =
+connectSMPProxiedRelay c@ProtocolClient {client_ = PClient {tcpConnectTimeout, tcpTimeout, proxiedRelayVRange}} nm relayServ@ProtocolServer {port = relayPort, keyHash = C.KeyHash kh} proxyAuth =
   sendProtocolCommand_ c nm Nothing tOut Nothing NoEntity (Cmd SProxiedClient (PRXY relayServ proxyAuth)) >>= \case
     PKEY sId vr (CertChainPubKey chain key) ->
-      case supportedClientSMPRelayVRange `compatibleVersion` vr of
+      case proxiedRelayVRange `compatibleVersion` vr of
         Nothing -> throwE $ transportErr TEVersion
         Just (Compatible v) -> do
           relayKey <- liftEitherWith (const $ transportErr $ TEHandshake IDENTITY) =<< liftIO (runExceptT $ validateRelay chain key)
@@ -1169,7 +1175,7 @@ instance StrEncoding ProxyClientError where
 -- consider how to process slow responses - is it handled somehow locally or delegated to the caller
 -- this method is used in the client
 -- sends PFWD :: C.PublicKeyX25519 -> EncTransmission -> Command Sender
--- receives PRES :: EncResponse -> BrokerMsg -- proxy to client
+-- receives PRES :: Maybe C.CbNonce -> EncResponse -> BrokerMsg -- proxy to client
 
 -- When client sends message via proxy, there may be one successful scenario and 9 error scenarios
 -- as shown below (WTF stands for unexpected response, ??? for response that failed to parse).
@@ -1228,14 +1234,14 @@ proxySMPCommand c@ProtocolClient {thParams = proxyThParams, client_ = PClient {c
     TBError e _ : _ -> throwE $ PCETransportError e
     TBTransmission s _ : _ -> pure s
     TBTransmissions s _ _ : _ -> pure s
-  et <- liftEitherWith PCECryptoError $ EncTransmission <$> C.cbEncrypt cmdSecret nonce b paddedProxiedTLength
+  et <- liftEitherWith PCECryptoError $ EncTransmission <$> C.cbEncrypt cmdSecret (encTransmissionNonce v nonce) b paddedProxiedTLength
   -- proxy interaction errors are wrapped
   let tOut = Just $ 2 * netTimeoutInt tcpTimeout nm
   tryE (sendProtocolCommand_ c nm (Just nonce) tOut Nothing (EntityId sessionId) (Cmd SProxiedClient (PFWD v cmdPubKey et))) >>= \case
     Right r -> case r of
-      PRES (EncResponse er) -> do
+      PRES nonce_ (EncResponse er) -> do
         -- server interaction errors are thrown directly
-        t' <- liftEitherWith PCECryptoError $ C.cbDecrypt cmdSecret (C.reverseNonce nonce) er
+        t' <- liftEitherWith PCECryptoError $ C.cbDecrypt cmdSecret (fromMaybe (C.reverseNonce nonce) nonce_) er
         case tParse serverThParams t' of
           t'' :| [] -> case tDecodeClient serverThParams t'' of
             (_, _, cmd) -> case cmd of
@@ -1253,10 +1259,10 @@ proxySMPCommand c@ProtocolClient {thParams = proxyThParams, client_ = PClient {c
 
 -- this method is used in the proxy
 -- sends RFWD :: EncFwdTransmission -> Command Sender
--- receives RRES :: EncFwdResponse -> BrokerMsg
+-- receives RRES :: Maybe C.CbNonce -> EncFwdResponse -> BrokerMsg
 -- proxy should send PRES to the client with EncResponse
 -- Always uses background timeout mode
-forwardSMPTransmission :: SMPClient -> CorrId -> VersionSMP -> C.PublicKeyX25519 -> EncTransmission -> ExceptT SMPClientError IO EncResponse
+forwardSMPTransmission :: SMPClient -> CorrId -> VersionSMP -> C.PublicKeyX25519 -> EncTransmission -> ExceptT SMPClientError IO (Maybe C.CbNonce, EncResponse)
 forwardSMPTransmission c@ProtocolClient {thParams, client_ = PClient {clientCorrId = g}} fwdCorrId fwdVersion fwdKey fwdTransmission = do
   -- prepare params
   sessSecret <- case thAuth thParams of
@@ -1268,11 +1274,11 @@ forwardSMPTransmission c@ProtocolClient {thParams, client_ = PClient {clientCorr
       eft = EncFwdTransmission $ C.cbEncryptNoPad sessSecret nonce (smpEncode fwdT)
   -- send
   sendProtocolCommand_ c NRMBackground (Just nonce) Nothing Nothing NoEntity (Cmd SProxyService (RFWD eft)) >>= \case
-    RRES (EncFwdResponse efr) -> do
+    RRES nonce_ (EncFwdResponse efr) -> do
       -- unwrap
       r' <- liftEitherWith PCECryptoError $ C.cbDecryptNoPad sessSecret (C.reverseNonce nonce) efr
       FwdResponse {fwdCorrId = _, fwdResponse} <- liftEitherWith (const $ PCEResponseError BLOCK) $ smpDecode r'
-      pure fwdResponse
+      pure (nonce_, fwdResponse)
     r -> throwE $ unexpectedResponse r
 
 -- get queue information - always sent interactively

src/Simplex/Messaging/Protocol.hs

@@ -168,6 +168,7 @@ module Simplex.Messaging.Protocol
     EncFwdTransmission (..),
     EncResponse (..),
     EncTransmission (..),
+    encTransmissionNonce,
     FwdResponse (..),
     FwdTransmission (..),
     NameRecord (..),
@@ -280,7 +281,7 @@ import Simplex.Messaging.ServiceScheme
 import Simplex.Messaging.SimplexName (LabelHash, SimplexDomain (..), SimplexTLD (..), fullDomainName, labelHash)
 import Simplex.Messaging.Transport
 import Simplex.Messaging.Transport.Client (TransportHost, TransportHosts (..))
-import Simplex.Messaging.Util (bshow, eitherToMaybe, safeDecodeUtf8, (<$?>))
+import Simplex.Messaging.Util (bshow, eitherToMaybe, packZipWith, safeDecodeUtf8, (<$?>))
 import Simplex.Messaging.Version
 import Simplex.Messaging.Version.Internal
 
@@ -702,6 +703,11 @@ instance Encoding NewNtfCreds where
 newtype EncTransmission = EncTransmission ByteString
   deriving (Show)
 
+encTransmissionNonce :: VersionSMP -> C.CbNonce -> C.CbNonce
+encTransmissionNonce v nonce@(C.CbNonce s)
+  | v >= fwdNoncesSMPVersion = C.cbNonce $ packZipWith xor (smpEncode v) s <> BS.drop 2 s
+  | otherwise = nonce
+
 data FwdTransmission = FwdTransmission
   { fwdCorrId :: CorrId,
     fwdVersion :: VersionSMP,
@@ -737,8 +743,8 @@ data BrokerMsg where
   NMSG :: C.CbNonce -> EncNMsgMeta -> BrokerMsg
   -- Should include certificate chain
   PKEY :: SessionId -> VersionRangeSMP -> CertChainPubKey -> BrokerMsg -- TLS-signed server key for proxy shared secret and initial sender key
-  RRES :: EncFwdResponse -> BrokerMsg -- relay to proxy
-  PRES :: EncResponse -> BrokerMsg -- proxy to client
+  RRES :: Maybe C.CbNonce -> EncFwdResponse -> BrokerMsg -- relay to proxy
+  PRES :: Maybe C.CbNonce -> EncResponse -> BrokerMsg -- proxy to client
   END :: BrokerMsg
   ENDS :: Int64 -> IdsHash -> BrokerMsg
   DELD :: BrokerMsg
@@ -1985,8 +1991,8 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where
     NID nId srvNtfDh -> e (NID_, ' ', nId, srvNtfDh)
     NMSG nmsgNonce encNMsgMeta -> e (NMSG_, ' ', nmsgNonce, encNMsgMeta)
     PKEY sid vr certKey -> e (PKEY_, ' ', sid, vr, certKey)
-    RRES (EncFwdResponse encBlock) -> e (RRES_, ' ', Tail encBlock)
-    PRES (EncResponse encBlock) -> e (PRES_, ' ', Tail encBlock)
+    RRES nonce_ (EncFwdResponse encBlock) -> fwdResp RRES_ nonce_ encBlock
+    PRES nonce_ (EncResponse encBlock) -> fwdResp PRES_ nonce_ encBlock
     END -> e END_
     ENDS n idsHash -> serviceResp ENDS_ n idsHash
     DELD -> e DELD_
@@ -2010,6 +2016,9 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where
       serviceResp tag n idsHash
         | v >= rcvServiceSMPVersion = e (tag, ' ', n, idsHash)
         | otherwise = e (tag, ' ', n)
+      fwdResp tag nonce_ encBlock
+        | v >= fwdNoncesSMPVersion = e (tag, ' ', nonce_, Tail encBlock)
+        | otherwise = e (tag, ' ', Tail encBlock)
 
   protocolP v = \case
     MSG_ -> do
@@ -2041,8 +2050,8 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where
     NID_ -> NID <$> _smpP <*> smpP
     NMSG_ -> NMSG <$> _smpP <*> smpP
     PKEY_ -> PKEY <$> _smpP <*> smpP <*> smpP
-    RRES_ -> RRES <$> (EncFwdResponse . unTail <$> _smpP)
-    PRES_ -> PRES <$> (EncResponse . unTail <$> _smpP)
+    RRES_ -> fwdRespP RRES EncFwdResponse
+    PRES_ -> fwdRespP PRES EncResponse
     END_ -> pure END
     ENDS_ -> serviceRespP ENDS
     DELD_ -> pure DELD
@@ -2059,6 +2068,9 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where
       serviceRespP resp
         | v >= rcvServiceSMPVersion = resp <$> _smpP <*> smpP
         | otherwise = resp <$> _smpP <*> pure mempty
+      fwdRespP :: (Maybe C.CbNonce -> a -> BrokerMsg) -> (ByteString -> a) -> Parser BrokerMsg
+      fwdRespP resp enc = resp <$> (A.space *> nonceP) <*> (enc <$> A.takeByteString)
+      nonceP = if v >= fwdNoncesSMPVersion then smpP else pure Nothing
 
   fromProtocolError = \case
     PECmdSyntax -> CMD SYNTAX
@@ -2075,7 +2087,7 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where
     -- PONG response must not have queue ID
     PONG -> noEntityMsg
     PKEY {} -> noEntityMsg
-    RRES _ -> noEntityMsg
+    RRES {} -> noEntityMsg
     ALLS -> noEntityMsg
     RNAME {} -> noEntityMsg
     -- other broker responses must have queue ID

src/Simplex/Messaging/Server.hs

@@ -1462,7 +1462,7 @@ client
             inc own pRequests
             forkProxiedCmd $ do
               liftIO (runExceptT (forwardSMPTransmission smp corrId fwdV pubKey encBlock) `E.catches` clientHandlers)  >>= \case
-                Right r -> PRES r <$ inc own pSuccesses
+                Right (nonce_, r) -> PRES nonce_ r <$ inc own pSuccesses
                 Left e -> ERR (smpProxyError e) <$ case e of
                   PCEProtocolError {} -> inc own pSuccesses
                   _ -> inc own pErrorsOther
@@ -2131,7 +2131,7 @@ client
           unless (fwdVersion `isCompatible` thServerVRange thParams') $ throwE $ transportErr TEVersion
           let clientSecret = C.dh' fwdKey serverPrivKey
               clientNonce = C.cbNonce $ bs fwdCorrId
-          b <- liftEitherWith (const CRYPTO) $ C.cbDecrypt clientSecret clientNonce et
+          b <- liftEitherWith (const CRYPTO) $ C.cbDecrypt clientSecret (encTransmissionNonce fwdVersion clientNonce) et
           let clntTHParams = smpTHParamsSetVersion fwdVersion thParams'
           -- only allowing single forwarded transactions
           t' <- case tParse clntTHParams b of
@@ -2144,9 +2144,13 @@ client
                   TBError _ _ : _ -> throwE BLOCK
                   TBTransmission b' _ : _ -> pure b'
                   TBTransmissions b' _ _ : _ -> pure b'
-                r2 <- liftEitherWith (const BLOCK) $ EncResponse <$> C.cbEncrypt clientSecret (C.reverseNonce clientNonce) r' paddedProxiedTLength
+                nonce_ <-
+                  if fwdVersion >= fwdNoncesSMPVersion
+                    then Just <$> (atomically . C.randomCbNonce =<< asks random)
+                    else pure Nothing
+                r2 <- liftEitherWith (const BLOCK) $ EncResponse <$> C.cbEncrypt clientSecret (fromMaybe (C.reverseNonce clientNonce) nonce_) r' paddedProxiedTLength
                 let fr = FwdResponse {fwdCorrId, fwdResponse = r2}
-                pure $ RRES $ EncFwdResponse $ C.cbEncryptNoPad sessSecret (C.reverseNonce proxyNonce) (smpEncode fr)
+                pure $ RRES nonce_ $ EncFwdResponse $ C.cbEncryptNoPad sessSecret (C.reverseNonce proxyNonce) (smpEncode fr)
           -- the inner response, or Nothing if forked (RSLV).
           r_ <- lift (rejectOrVerify clntThAuth t') >>= \case
             -- rejectOrVerify filters allowed commands, no need to repeat it here.

src/Simplex/Messaging/Transport.hs

@@ -54,6 +54,7 @@ module Simplex.Messaging.Transport
     namesSMPVersion,
     serverInfoSMPVersion,
     nameAvailSMPVersion,
+    fwdNoncesSMPVersion,
     simplexMQVersion,
     smpBlockSize,
     TransportConfig (..),
@@ -177,6 +178,7 @@ smpBlockSize = 16384
 -- 20 - public namespaces resolver, RSLV command (6/20/2026)
 -- 21 - server public information in handshake (7/5/2026)
 -- 22 - RNAME answers name availability as well as the record (7/25/2026)
+-- 23 - version in forwarded command nonce, random nonce in forwarded responses (10/2/2026)
 
 data SMPVersion
 
@@ -218,6 +220,9 @@ serverInfoSMPVersion = VersionSMP 21
 nameAvailSMPVersion :: VersionSMP
 nameAvailSMPVersion = VersionSMP 22
 
+fwdNoncesSMPVersion :: VersionSMP
+fwdNoncesSMPVersion = VersionSMP 23
+
 minClientSMPRelayVersion :: VersionSMP
 minClientSMPRelayVersion = VersionSMP 14
 
@@ -225,20 +230,20 @@ minServerSMPRelayVersion :: VersionSMP
 minServerSMPRelayVersion = VersionSMP 14
 
 currentClientSMPRelayVersion :: VersionSMP
-currentClientSMPRelayVersion = VersionSMP 22
+currentClientSMPRelayVersion = VersionSMP 23
 
 currentServerSMPRelayVersion :: VersionSMP
-currentServerSMPRelayVersion = VersionSMP 22
+currentServerSMPRelayVersion = VersionSMP 23
 
 -- Max SMP protocol version to be used in e2e encrypted connection between
 -- client and server, as defined by SMP proxy. Normally set below the current
 -- version to prevent client version fingerprinting by the destination relays
--- when clients upgrade at different times. Pinned to the current version (22)
--- for this release because a proxied RSLV only carries availability from
--- nameAvailSMPVersion (22), so the one-version anti-fingerprinting buffer does
--- not apply yet; it reappears once the current version advances past 22.
+-- when clients upgrade at different times. Pinned to the current version (23)
+-- for this release because forwarded commands use the nonces from
+-- fwdNoncesSMPVersion (23), so the one-version anti-fingerprinting buffer does
+-- not apply yet; it reappears once the current version advances past 23.
 proxiedSMPRelayVersion :: VersionSMP
-proxiedSMPRelayVersion = VersionSMP 22
+proxiedSMPRelayVersion = VersionSMP 23
 
 -- minimal supported protocol version is 14
 supportedClientSMPRelayVRange :: VersionRangeSMP