simplify

protocol/simplex-messaging.md

@@ -1172,10 +1172,9 @@ The shared secret for encrypting transmission bodies between proxy router and de
 
 
 ```abnf
-relayResponse = %s"RRES" SP <encrypted(responseTransmission)>
-responseTransmission = fwdCorrId [fwdResponseNonce] forwardedResponse
+relayResponse = %s"RRES" SP [responseNonce] <encrypted(responseTransmission)>
+responseTransmission = fwdCorrId forwardedResponse
   ; fwdCorrId and forwardedResponse defined above in RFWD section
-fwdResponseNonce = 24*24 OCTET ; when fwdSmpVersion is 23 or higher
 ```
 
 ### Short link commands

src/Simplex/Messaging/Client.hs

@@ -162,7 +162,7 @@ import Numeric.Natural
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String
-import Simplex.Messaging.Parsers (defaultJSON, dropPrefix, enumJSON, parseAll, sumTypeJSON)
+import Simplex.Messaging.Parsers (defaultJSON, dropPrefix, enumJSON, sumTypeJSON)
 import Simplex.Messaging.Protocol
 import Simplex.Messaging.Protocol.Types
 import Simplex.Messaging.Server.QueueStore.QueueInfo
@@ -1259,7 +1259,7 @@ 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 (Maybe C.CbNonce, EncResponse)
@@ -1274,11 +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 = _, fwdNonce, fwdResponse} <- liftEitherWith (const $ PCEResponseError BLOCK) $ parseAll (fwdResponseP fwdVersion) r'
-      pure (fwdNonce, fwdResponse)
+      FwdResponse {fwdCorrId = _, fwdResponse} <- liftEitherWith (const $ PCEResponseError BLOCK) $ smpDecode r'
+      pure (nonce_, fwdResponse)
     r -> throwE $ unexpectedResponse r
 
 -- get queue information - always sent interactively

src/Simplex/Messaging/Protocol.hs

@@ -170,8 +170,6 @@ module Simplex.Messaging.Protocol
     EncTransmission (..),
     encTransmissionNonce,
     FwdResponse (..),
-    encodeFwdResponse,
-    fwdResponseP,
     FwdTransmission (..),
     NameRecord (..),
     MsgFlags (..),
@@ -745,7 +743,7 @@ 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
+  RRES :: Maybe C.CbNonce -> EncFwdResponse -> BrokerMsg -- relay to proxy
   PRES :: Maybe C.CbNonce -> EncResponse -> BrokerMsg -- proxy to client
   END :: BrokerMsg
   ENDS :: Int64 -> IdsHash -> BrokerMsg
@@ -769,20 +767,15 @@ newtype EncFwdResponse = EncFwdResponse ByteString
 
 data FwdResponse = FwdResponse
   { fwdCorrId :: CorrId,
-    fwdNonce :: Maybe C.CbNonce,
     fwdResponse :: EncResponse
   }
 
-encodeFwdResponse :: FwdResponse -> ByteString
-encodeFwdResponse FwdResponse {fwdCorrId = CorrId corrId, fwdNonce, fwdResponse = EncResponse t} =
-  smpEncode corrId <> maybe "" smpEncode fwdNonce <> smpEncode (Tail t)
-
-fwdResponseP :: VersionSMP -> Parser FwdResponse
-fwdResponseP v = do
-  corrId <- smpP
-  fwdNonce <- if v >= fwdNoncesSMPVersion then Just <$> smpP else pure Nothing
-  Tail t <- smpP
-  pure FwdResponse {fwdCorrId = CorrId corrId, fwdNonce, fwdResponse = EncResponse t}
+instance Encoding FwdResponse where
+  smpEncode FwdResponse {fwdCorrId = CorrId corrId, fwdResponse = EncResponse t} =
+    smpEncode (corrId, Tail t)
+  smpP = do
+    (corrId, Tail t) <- smpP
+    pure FwdResponse {fwdCorrId = CorrId corrId, fwdResponse = EncResponse t}
 
 newtype EncResponse = EncResponse ByteString
   deriving (Eq, Show)
@@ -1998,7 +1991,9 @@ 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)
+    RRES nonce_ (EncFwdResponse encBlock)
+      | v >= fwdNoncesSMPVersion -> e (RRES_, ' ', nonce_, Tail encBlock)
+      | otherwise -> e (RRES_, ' ', Tail encBlock)
     PRES nonce_ (EncResponse encBlock)
       | v >= fwdNoncesSMPVersion -> e (PRES_, ' ', nonce_, Tail encBlock)
       | otherwise -> e (PRES_, ' ', Tail encBlock)
@@ -2056,7 +2051,9 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where
     NID_ -> NID <$> _smpP <*> smpP
     NMSG_ -> NMSG <$> _smpP <*> smpP
     PKEY_ -> PKEY <$> _smpP <*> smpP <*> smpP
-    RRES_ -> RRES <$> (EncFwdResponse . unTail <$> _smpP)
+    RRES_
+      | v >= fwdNoncesSMPVersion -> RRES <$> _smpP <*> (EncFwdResponse . unTail <$> smpP)
+      | otherwise -> RRES Nothing . EncFwdResponse . unTail <$> _smpP
     PRES_
       | v >= fwdNoncesSMPVersion -> PRES <$> _smpP <*> (EncResponse . unTail <$> smpP)
       | otherwise -> PRES Nothing . EncResponse . unTail <$> _smpP
@@ -2092,7 +2089,7 @@ 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

@@ -2144,13 +2144,13 @@ client
                   TBError _ _ : _ -> throwE BLOCK
                   TBTransmission b' _ : _ -> pure b'
                   TBTransmissions b' _ _ : _ -> pure b'
-                fwdNonce <-
+                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) fwdNonce) r' paddedProxiedTLength
-                let fr = FwdResponse {fwdCorrId, fwdNonce, fwdResponse = r2}
-                pure $ RRES $ EncFwdResponse $ C.cbEncryptNoPad sessSecret (C.reverseNonce proxyNonce) (encodeFwdResponse fr)
+                r2 <- liftEitherWith (const BLOCK) $ EncResponse <$> C.cbEncrypt clientSecret (fromMaybe (C.reverseNonce clientNonce) nonce_) r' paddedProxiedTLength
+                let fr = FwdResponse {fwdCorrId, fwdResponse = r2}
+                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.