WIP

5.7.4.0
agent: remove critical error on subscription timeout (#1146 )
2026-08-30 18:28:23 +00:00 · 2024-05-12 21:19:27 +03:00 · 2024-05-11 23:39:28 +01:00 · 2024-05-11 23:38:27 +01:00 · 2024-05-10 22:24:00 +01:00 · 2024-05-10 22:19:11 +01:00
57 changed files with 865 additions and 1301 deletions
@@ -49,7 +49,7 @@ jobs:
        run: cabal build --enable-tests

      - name: Test
-        timeout-minutes: 40
+        timeout-minutes: 30
        shell: bash
        run: cabal test --test-show-details=direct

@@ -1,3 +1,50 @@
+# 5.7.3
+
+SMP/NTF protocol:
+- add ALPN for handshake version negotiation, similar to XFTP (to preserve backwards compatibility with the old clients).
+- upgrade clients to versions v7/v2 of the protocols.
+
+SMP server:
+- faster responses to subscription requests.
+
+XFTP client:
+- fix network exception during file download treated as permanent file error.
+
+SMP agent:
+- do not report subscription timeouts while client is offline.
+
+# 5.7.2
+
+SMP agent:
+- fix connections failing when connecting via link due to race condition on slow network.
+- remove concurrency limit when waiting for connection subscription.
+- remove TLS timeout.
+
+# 5.7.1
+
+SMP agent:
+- increase timeout for TLS connection via SOCKS
+
+# 5.7.0
+
+Version 5.7.0.4
+
+_Please note_: the earliest SimpleX Chat clients supported by this version of the servers is 5.5.3 (released on February 11, 2024).
+
+SMP server:
+- increase max SMP protocol version to 7 (support for deniable authenticators).
+
+NTF server:
+- increase max NTF protocol version to 2 (support for deniable authenticators).
+
+XFTP server:
+- version handshake using ALPN.
+
+SMP agent:
+- increase timeouts for XFTP files.
+- don't send commands after timeout.
+- PQ encryption support.
+
 # 5.6.2

 Version 5.6.2.2.
@@ -1,23 +0,0 @@
-common:
-  corrId - random BS, used as CbNonce
-  entityId - p2r tlsUniq
-
-# setup
-s->p: "proxy", uri, auth?
-  # unless connected
-  p->r: "p_handshake"
-  p<-r: "r_key", tls-signed dh pub
-s<-r: "r_key", tls-signed dh pub # reply entityId contains tlsUniq
-
-# working
-s ; generate random dh priv, make shared secret
-s->p: s2r("forward", random dh pub, SEND command blob)
-  p->r: p2r("forward", random dh pub, s2r("forward", ...)))
-    r->c@ "msg", ...
-  p<-r: p2r("r_res", s2r("ok" / "error", error))
-s<-p@ s2r("ok" / "error", error)
-
-# expired
-  p<-r@ p2r("error", "key expired")
-s<-p@ "error", "key expired"
-s ; reconnect
@@ -1,5 +1,5 @@
 name: simplexmq
-version: 5.6.2.2
+version: 5.7.4.0
 synopsis: SimpleXMQ message broker
 description: |
  This package includes <./docs/Simplex-Messaging-Server.html server>,
@@ -71,6 +71,7 @@ dependencies:
  - transformers == 0.6.*
  - unliftio == 0.2.*
  - unliftio-core == 0.2.*
+  - unordered-containers
  - websockets == 0.12.*
  - yaml == 0.11.*
  - zstd == 0.1.3.*
@@ -2,9 +2,9 @@

 ## Problem

-SMP protocol relays are chosen and can be controlled by the message recipients. It means that the recipients can find out IP addresses of message senders by modifying SMP relay code (or by using proxies and timing correlation), unless the senders use VPN or some overlay network. Tor is an adequate solution in most cases to mitigate it, but it requires additional technical knowledge to install and configure (even installing Orbot on Android is seen as "complex" by many users), and reduces usability because of higher latency.
+SMP protocol relays are chosen and can be controlled by the message recipients. It means that the recipients can find out IP addresses of message senders by modifying SMP relay code (or by using proxies and timing correlation), unless the senders use VPN or some overlay network. Tor is an audequate solution in most cases to mitigate it, but it requires additional technical knowledge to install and configure (even installing Orbot on Android is seen as "complex" by many users), and reduces usability because of higher latency.

-The lack of in-built IP address protection is the main concern of many users, particularly given that most people do not realize that it is lacking by default - without transport protection SimpleX is not perceived as a "whole product".
+The lack of in-built IP address protection is the main concern of many users, particularly given that most people do not realise that it is lacking by default - without transport protection SimpleX is not perceived as a "whole product".

 Similarly, XFTP protocol relays are chosen by senders, and they can be used to detect file recipients' IP addresses.

@@ -43,7 +43,7 @@ Overall, this is not a viable or even appropriate option for the current stage.

 3. SMP / XFTP proxy.

-Introduce SMP and XFTP protocol extensions to allow message senders and file recipients to delegate the tasks of sending messages and receiving files to the proxies, so that peer-chosen relays can only observe IP addresses of the proxies and not of the users.
+Introduce SMP and XFTP protocol extenstions to allow message senders and file recipients to delegate the tasks of sending messages and receiving files to the proxies, so that peer-chosen relays can only observe IP addresses of the proxies and not of the users.

 Pros:
 - no dependency on and lower latency than via Tor
@@ -68,7 +68,7 @@ Below considers this design.

 2. SMP proxy should not be able to observe queue addresses and their count on the destination relays. This requirement is not needed for XFTP proxies, as each file chunk is downloaded only once, so there is no need to hide its address.

-3. There must be no identifiers and ciphertext in common in outgoing and incoming traffic inside TLS (the current designs have this quality).
+3. There must be no identifiers and cyphertext in common in outgoing and incoming traffic inside TLS (the current designs have this quality).

 4. Traffic between the client and destination relays must be e2e encrypted, with MITM-by-proxy mitigated, relying on the relay identity (certificate fingerprint), ideally without any additional fingerprint in relay address.

@@ -97,11 +97,11 @@ This would also reduce the difference in how the traffic looks to the observer -

 The flow of the messages will be:

-1. Client requests proxy to create session with the relay by sending `PRXY` command with the SMP relay address and optional proxy basic AUTH (below). It should be possible to batch multiple session requests into one block, to reduce traffic.
+1. Client requests proxy to create session with the relay by sending `server` command with the SMP relay address and optional proxy basic AUTH (below). It should be possible to batch multiple session requests into one block, to reduce traffic.

-2. Proxy connects to SMP relay, negotiating a shared secret via a handshake headers - it will be used to encrypt all sender blocks inside TLS (proxy-relay encryption). DH key returned by SMP relay in handshake will also be used to encrypt client commands, combining it with random per-command keys (sender-relay encryption, to hide metadata sent to the destination relay from proxy).
+2. Proxy connects to SMP relay, negotiating a shared secret in the handshake that will be used to encrypt all sender blocks inside TLS (proxy-relay encryption). SMP relay also returns in handshake its temporary DH key to agree e2e encryption with the client (sender-relay encryption, to hide metadata sent to the destination relay from proxy).

-3. Proxy replies to sender with `PKEY` message using "entityId" transmission field to indicate session ID for using in further requests, relay DH key for _s2r_ encryption with the client - this key is signed with the TLS online private key associated with the certificate (its fingerprint is included in the relay address), and the TLS session ID between proxy and relay (this session ID must be used in transmissions, to mitigate replay attacks as before).
+3. Proxy replies with `server_id` command including relay session ID to identify it in further requests, relay DH key for e2e encryption with the client - this key is signed with the TLS online private key associated with the certificate (its fingerprint is included in the relay address), and the TLS session ID between proxy and relay (this session ID must be used in transmissions, to mitigate replay attacks as before).

 A possible attack here is that proxy can use this TLS session to replay commands received from the client. Possibly, it could be mitigated with a bloom filter per proxy/SMP relay connection that would reject the repeated DH keys (that need to be used for replay), and also with DH key expiration (this mitigation should allow some acceptable rate of false positives from the bloom filter).

@@ -113,11 +113,11 @@ It is important that the same public key from destination relay is returned to a

 *Unrelated cosideration for SMP protocol privacy improvement*: instead of signing commands to the destination relay, the sender could have a ratchet per queue agreed with the destination relay that would simply use authenticated encryption with per-message symmetric key to encrypt the message on the way to relay, and this encryption would be used as a proof of sender.

-4. Now the client sends `PFWD` to proxy, which it then forwards to SMP relay as `RFWD`, applying _p2r_ encryption layer.
+4. Now the client sends `forward` to proxy, which it then forwards to SMP relay, applying additional encryption layer.

-5. SMP relay sends `RRES` to proxy applying _p2r_ encryption layer, which it then forwards to the client as `PRES`, removing the _p2r_ encryption layer.
+5. SMP relay sends `response` to proxy applying additional encryption layer, which it then forwards to the client removing the additional encryption layer.

-Effectively it works as a simplified two-hop onion routing with the first relay (proxy) chosen by the sending client and the second relay chosen by the recipient, not only protecting senders' IP addresses from the recipients' relays, but also preventing recipients' relays from correlating senders' traffic to different queues, as TLS session is owned by the proxy now and it mixes the traffic from multiple senders. To correlate traffic to users, proxy and relay would have to combine their information. SMP relays are still able to correlate traffic to receiving users via transport session.
+Effectively it works as a simplified two-hop onion routing with the first relay (proxy) chosen by the sending client and the second relay chosen by the recipient, not only protecting senders' IP addresses from the recipients' relays, but also preventing recipients relays from correlating senders' traffic to different queues, as TLS session is owned by the proxy now and it mixes the traffic from multiple senders. To correlate traffic to users, proxy and relay would have to combine their information. SMP relays are still able to correlate traffic to receiving users via transport session.

 Sequence diagram for sending the message via SMP proxy:

@@ -126,33 +126,33 @@ Sequence diagram for sending the message via SMP proxy:
 |  sending  |               |    SMP    |                     |    SMP    |              | receiving |
 |  client   |               |   proxy   |                     |   relay   |              |  client   |
 -------------               -------------                     -------------              -------------
-     |           `PRXY`           |                                 |                          |
-     | -------------------------> |                                 |                          |
+     |       `server`             |                                 |                          |
+     | -------------------------> |   create TLS session, get keys  |                          |
     |                            | ------------------------------> |                          |
-     |                            |          SMP handshake          |                          |
-     |                            | <------------------------------ |                          |
-     |           `PKEY`           |                                 |                          |
+     |        `server_id`         |       (if doesn't exist)        |                          |
     | <------------------------- |                                 |                          |
     |                            |                                 |                          |
-     |        `PFWD` (s2r)        |                                 |                          |
-     | -------------------------> |                                 |                          |
-     |                            |           `RFWD` (p2r)          |                          |
+     | TLS(F:s2r(SEND(e2e(msg)))) |                                 |                          |
+     | -------------------------> | TLS(F:p2r(s2r(SEND(e2e(msg))))) |                          |
     |                            | ------------------------------> |                          |
-     |                            |           `RRES` (p2r)          |                          |
-     |                            | <------------------------------ |                          |
-     |        `PRES` (s2r)        |                                 |           `MSG`          |
-     | <------------------------- |                                 | -----------------------> |
-     |                            |                                 |           `ACK`          |
+     |                            |                                 |                          |
+     |                            |     TLS(R:p2r(s2r(OK/ERR)))     |                          |
+     |     TLS(R:s2r(OK/ERR))     | <------------------------------ |                          |
+     | <------------------------- |                                 | TLS(MSG(r2c(e2e(msg))))  |
+     |                            |                                 | -----------------------> |
+     |                            |                                 |                          |
+     |                            |                                 |        TLS(ACK)          |
     |                            |                                 | <----------------------- |
     |                            |                                 |                          |
     |                            |                                 |                          |
+
 ```

-Below diagram shows the encrypttion layers for `PFWD`/`RFWD` commands and `RRES`/`PRES` responses:
+Below diagram shows the encrypttion layers for `forward` and `response` commands:

- s2r (added) - encryption between client and SMP relay, with relay key returned in relay handshake, with MITM by proxy mitigated by verifying the certificate fingerprint included in the relay address.
+- s2r (added) - encryption between client and SMP relay, with relay key returned in server_id command, with MITM by proxy mitigated by verifying the certificate fingerprint included in the relay address.
 - e2e (exists now) - end-to-end encryption per SMP queue, with double ratchet e2e encryption inside it.
- p2r (added) - additional encryption between proxy and SMP relay with the shared secret agreed in the handshake, to mitigate traffic correlation inside TLS.
+- p2r (added) - additional encryption between proxy and SMP relay with key agreed in the handshake, to mitigate traffic correlation inside TLS. This key could also be signed by the same certificate, if we don't want to rely on TLS security.
 - r2c (exists now) additional encryption between SMP relay and client to prevent traffic correlation inside TLS.

 ```
@@ -167,32 +167,27 @@ Below diagram shows the encrypttion layers for `PFWD`/`RFWD` commands and `RRES`
 -----------------             -----------------  -- TLS --  -----------------             -----------------
 ```

-Question: should proxy declare its role in handshake? When proxy connects to SMP relay it would indicate in the handshake that it will act as a proxy and the SMP relay would expect the same `forward` commands and reply with `response`s.
+When proxy connects to SMP relay it would indicate in the handshake that it will use proxy protocol and the SMP relay would expect the same `forward` commands and reply with `response`s.

-Common SMP transmission format (v4), for reference:
+Below syntax aims to fit in 16kb block using spare capacity in SMP protocol.

 ```abnf
-paddedTransmission = <padded(transmission), 16384>
-transmission = signature signed
-signature = 0 ; empty signatures here
-signed = sessionIdentifier corrId entityId (smpCommand / brokerMsg)
+proxy_block = padded(proxy_transmission, 16384)
+proxy_transmission = corr_id relay_session_id proxy_command
+corr_id = length *8 OCTET
+proxy_command = server / server_id / forward / response / error
+server = "S" address [relay_basic_auth] ; creates transport session between proxy and relay
+server_id = "I" relay_session_id tls_session_id signed_relay_key ;
+    ; session_id is the TLS session ID between proxy and relay, it has to be included inside encrypted block to prevent replay attacks
+forward = %s"F" random_dh_pub_key encrypted_block ; it's important that a new key is used for each command, to prevent any correlation by proxy or by destination relay
+response = %s"R" encrypted_block; response received from the destination SMP relay
+relay_session_id = length *8 OCTET
+error = %s"E" error
 ```

- `corrId` is fully random each time and used as a nonce for encrypted blocks.
- `entityId` carries tlsUniq from the current proxy-to-relay connection.
- `smpCommand` gets extended with `s2p_command / p2r_command`.
- `brokerMsg` gets extended with `r_key / r_response`.
+The overhead is: 1+8 (corrId) + 1+8 (relay_session_id) + 1 (command) + 1+32 (random_dh_pub_key) + 2 (original length) + 16 (auth tag for e2e encryption) + 16 (auth tag for proxy to relay encryption) = 86 bytes. The reserve for sent messages in SMP is ~84 bytes, so it should about fit with some reduced bytes somewhere.

-```abnf
-s2p_command = proxy / forward
-p2r_command = p_handshake ; forward is
-proxy = %s"PRXY" SP relayUri SP basicAuth
-relayUri = length %s"smp://" serverIdentity "@" srvHost [":" port]
-forward = %s"PFWD" SP dhPublic SP encryptedBlock
-r_key = %s"PKEY" SP dhPublic
-r_response = %s"RRES" SP encryptedBlock
-dhPublic = length x509encoded
-```
+Another possible design is to allow mixing sent messages and normal SMP commands in the same transport connection, but it can make fitting in the block a bit harder, additional overhead would be: 1 (transmission count) + 2 (transmission size) + 1 (empty signature) = 4 bytes.

 The above assumes that the client can only send one message to an SMP relay and then has to wait for response before sending the next message. Missing the response would cause re-delivery (further improvement is possible when proxy detects these redelieveries and not send them to relays but simply reply with the same response).

@@ -5,7 +5,7 @@ cabal-version: 1.12
 -- see: https://github.com/sol/hpack

 name:           simplexmq
-version:        5.6.2.2
+version:        5.7.4.0
 synopsis:       SimpleXMQ message broker
 description:    This package includes <./docs/Simplex-Messaging-Server.html server>,
                <./docs/Simplex-Messaging-Client.html client> and
@@ -230,6 +230,7 @@ library
    , transformers ==0.6.*
    , unliftio ==0.2.*
    , unliftio-core ==0.2.*
+    , unordered-containers
    , websockets ==0.12.*
    , yaml ==0.11.*
    , zstd ==0.1.3.*
@@ -305,6 +306,7 @@ executable ntf-server
    , transformers ==0.6.*
    , unliftio ==0.2.*
    , unliftio-core ==0.2.*
+    , unordered-containers
    , websockets ==0.12.*
    , yaml ==0.11.*
    , zstd ==0.1.3.*
@@ -380,6 +382,7 @@ executable smp-agent
    , transformers ==0.6.*
    , unliftio ==0.2.*
    , unliftio-core ==0.2.*
+    , unordered-containers
    , websockets ==0.12.*
    , yaml ==0.11.*
    , zstd ==0.1.3.*
@@ -455,6 +458,7 @@ executable smp-server
    , transformers ==0.6.*
    , unliftio ==0.2.*
    , unliftio-core ==0.2.*
+    , unordered-containers
    , websockets ==0.12.*
    , yaml ==0.11.*
    , zstd ==0.1.3.*
@@ -530,6 +534,7 @@ executable xftp
    , transformers ==0.6.*
    , unliftio ==0.2.*
    , unliftio-core ==0.2.*
+    , unordered-containers
    , websockets ==0.12.*
    , yaml ==0.11.*
    , zstd ==0.1.3.*
@@ -605,6 +610,7 @@ executable xftp-server
    , transformers ==0.6.*
    , unliftio ==0.2.*
    , unliftio-core ==0.2.*
+    , unordered-containers
    , websockets ==0.12.*
    , yaml ==0.11.*
    , zstd ==0.1.3.*
@@ -652,7 +658,6 @@ test-suite simplexmq-test
      ServerTests
      SMPAgentClient
      SMPClient
-      SMPProxyTests
      Util
      XFTPAgent
      XFTPCLI
@@ -722,6 +727,7 @@ test-suite simplexmq-test
    , transformers ==0.6.*
    , unliftio ==0.2.*
    , unliftio-core ==0.2.*
+    , unordered-containers
    , websockets ==0.12.*
    , yaml ==0.11.*
    , zstd ==0.1.3.*
@@ -97,8 +97,8 @@ defaultXFTPClientConfig =
      clientALPN = Just supportedXFTPhandshakes
    }

-getXFTPClient :: TVar ChaChaDRG -> TransportSession FileResponse -> XFTPClientConfig -> (XFTPClient -> IO ()) -> IO (Either XFTPClientError XFTPClient)
-getXFTPClient g transportSession@(_, srv, _) config@XFTPClientConfig {clientALPN, xftpNetworkConfig, serverVRange} disconnected = runExceptT $ do
+getXFTPClient :: TransportSession FileResponse -> XFTPClientConfig -> (XFTPClient -> IO ()) -> IO (Either XFTPClientError XFTPClient)
+getXFTPClient transportSession@(_, srv, _) config@XFTPClientConfig {clientALPN, xftpNetworkConfig, serverVRange} disconnected = runExceptT $ do
  let tcConfig = (transportClientConfig xftpNetworkConfig) {alpn = clientALPN}
      http2Config = xftpHTTP2Config tcConfig config
      username = proxyUsername transportSession
@@ -112,7 +112,7 @@ getXFTPClient g transportSession@(_, srv, _) config@XFTPClientConfig {clientALPN
      thParams0 = THandleParams {sessionId, blockSize = xftpBlockSize, thVersion = VersionXFTP 1, thAuth = Nothing, implySessId = False, batch = True}
  logDebug $ "Client negotiated handshake protocol: " <> tshow sessionALPN
  thParams@THandleParams {thVersion} <- case sessionALPN of
-    Just "xftp/1" -> xftpClientHandshakeV1 g serverVRange keyHash http2Client thParams0
+    Just "xftp/1" -> xftpClientHandshakeV1 serverVRange keyHash http2Client thParams0
    Nothing -> pure thParams0
    _ -> throwError $ PCETransportError (TEHandshake VERSION)
  logDebug $ "Client negotiated protocol: " <> tshow thVersion
@@ -120,13 +120,12 @@ getXFTPClient g transportSession@(_, srv, _) config@XFTPClientConfig {clientALPN
  atomically $ writeTVar clientVar $ Just c
  pure c

-xftpClientHandshakeV1 :: TVar ChaChaDRG -> VersionRangeXFTP -> C.KeyHash -> HTTP2Client -> THandleParamsXFTP 'TClient -> ExceptT XFTPClientError IO (THandleParamsXFTP 'TClient)
-xftpClientHandshakeV1 g serverVRange keyHash@(C.KeyHash kh) c@HTTP2Client {sessionId, serverKey} thParams0 = do
+xftpClientHandshakeV1 :: VersionRangeXFTP -> C.KeyHash -> HTTP2Client -> THandleParamsXFTP 'TClient -> ExceptT XFTPClientError IO (THandleParamsXFTP 'TClient)
+xftpClientHandshakeV1 serverVRange keyHash@(C.KeyHash kh) c@HTTP2Client {sessionId, serverKey} thParams0 = do
  shs@XFTPServerHandshake {authPubKey = ck} <- getServerHandshake
  (v, sk) <- processServerHandshake shs
-  (k, pk) <- atomically $ C.generateKeyPair g
-  sendClientHandshake XFTPClientHandshake {xftpVersion = v, keyHash, authPubKey = k}
-  pure thParams0 {thAuth = Just THAuthClient {serverPeerPubKey = sk, serverCertKey = ck, clientPrivKey = pk}, thVersion = v}
+  sendClientHandshake XFTPClientHandshake {xftpVersion = v, keyHash}
+  pure thParams0 {thAuth = Just THAuthClient {serverPeerPubKey = sk, serverCertKey = ck, sessSecret = Nothing}, thVersion = v}
  where
    getServerHandshake :: ExceptT XFTPClientError IO XFTPServerHandshake
    getServerHandshake = do
@@ -186,11 +185,9 @@ xftpClientError = \case

 sendXFTPCommand :: forall p. FilePartyI p => XFTPClient -> C.APrivateAuthKey -> XFTPFileId -> FileCommand p -> Maybe XFTPChunkSpec -> ExceptT XFTPClientError IO (FileResponse, HTTP2Body)
 sendXFTPCommand c@XFTPClient {thParams} pKey fId cmd chunkSpec_ = do
-  -- TODO random corrId
-  let corrIdUsedAsNonce = ""
  t <-
    liftEither . first PCETransportError $
-      xftpEncodeAuthTransmission thParams pKey (corrIdUsedAsNonce, fId, FileCmd (sFileParty @p) cmd)
+      xftpEncodeAuthTransmission thParams pKey ("", fId, FileCmd (sFileParty @p) cmd)
  sendXFTPTransmission c t chunkSpec_

 sendXFTPTransmission :: XFTPClient -> ByteString -> Maybe XFTPChunkSpec -> ExceptT XFTPClientError IO (FileResponse, HTTP2Body)
@@ -248,8 +245,13 @@ downloadXFTPChunk g c@XFTPClient {config} rpKey fId chunkSpec@XFTPRcvChunkSpec {
        let dhSecret = C.dh' sDhKey rpDhKey
        cbState <- liftEither . first PCECryptoError $ LC.cbInit dhSecret cbNonce
        let t = chunkTimeout config chunkSize
-        ExceptT (sequence <$> (t `timeout` download cbState)) >>= maybe (throwError PCEResponseTimeout) pure
+        ExceptT (sequence <$> (t `timeout` (download cbState `catches` errors))) >>= maybe (throwError PCEResponseTimeout) pure
        where
+          errors =
+            [ Handler $ \(_e :: H.HTTP2Error) -> pure $ Left PCENetworkError,
+              Handler $ \(e :: IOException) -> pure $ Left (PCEIOError e),
+              Handler $ \(_e :: SomeException) -> pure $ Left PCENetworkError
+            ]
          download cbState =
            runExceptT . withExceptT PCEResponseError $
              receiveEncFile chunkPart cbState chunkSpec `catchError` \e ->
@@ -11,7 +11,6 @@ import Control.Logger.Simple (logInfo)
 import Control.Monad
 import Control.Monad.Except
 import Control.Monad.Trans (lift)
-import Crypto.Random (ChaChaDRG)
 import Data.Bifunctor (first)
 import qualified Data.ByteString.Char8 as B
 import Data.Text (Text)
@@ -61,15 +60,15 @@ newXFTPAgent config = do

 type ME a = ExceptT XFTPClientAgentError IO a

-getXFTPServerClient :: TVar ChaChaDRG -> XFTPClientAgent -> XFTPServer -> ME XFTPClient
-getXFTPServerClient g XFTPClientAgent {xftpClients, config} srv = do
+getXFTPServerClient :: XFTPClientAgent -> XFTPServer -> ME XFTPClient
+getXFTPServerClient XFTPClientAgent {xftpClients, config} srv = do
  atomically getClientVar >>= either newXFTPClient waitForXFTPClient
  where
    connectClient :: ME XFTPClient
    connectClient =
      ExceptT $
        first (XFTPClientAgentError srv)
-          <$> getXFTPClient g (1, srv, Nothing) (xftpConfig config) clientDisconnected
+          <$> getXFTPClient (1, srv, Nothing) (xftpConfig config) clientDisconnected

    clientDisconnected :: XFTPClient -> IO ()
    clientDisconnected _ = do
@@ -333,9 +333,9 @@ cliSendFileOpts SendOptions {filePath, outputDir, numRecipients, xftpServers, re
          rKeys <- atomically $ L.fromList <$> replicateM numRecipients (C.generateAuthKeyPair C.SEd25519 g)
          digest <- liftIO $ getChunkDigest chunkSpec
          let ch = FileInfo {sndKey, size = fromIntegral chunkSize, digest}
-          c <- withRetry retryCount $ getXFTPServerClient g a xftpServer
+          c <- withRetry retryCount $ getXFTPServerClient a xftpServer
          (sndId, rIds) <- withRetry retryCount $ createXFTPChunk c spKey ch (L.map fst rKeys) auth
-          withReconnect g a xftpServer retryCount $ \c' -> uploadXFTPChunk c' spKey sndId chunkSpec
+          withReconnect a xftpServer retryCount $ \c' -> uploadXFTPChunk c' spKey sndId chunkSpec
          logInfo $ "uploaded chunk " <> tshow chunkNo
          uploaded <- atomically . stateTVar uploadedChunks $ \cs ->
            let cs' = fromIntegral chunkSize : cs in (sum cs', cs')
@@ -445,7 +445,7 @@ cliReceiveFile ReceiveOptions {fileDescription, filePath, retryCount, tempPath,
      when (FileSize encSize /= size) $ throwError $ CLIError "File size mismatch"
      liftIO $ printNoNewLine "Decrypting file..."
      CryptoFile path _ <- withExceptT cliCryptoError $ decryptChunks encSize chunkPaths key nonce $ fmap CF.plain . getFilePath
-      forM_ chunks $ acknowledgeFileChunk g a
+      forM_ chunks $ acknowledgeFileChunk a
      whenM (doesPathExist encPath) $ removeDirectoryRecursive encPath
      liftIO $ do
        printNoNewLine $ "File downloaded: " <> path
@@ -456,7 +456,7 @@ cliReceiveFile ReceiveOptions {fileDescription, filePath, retryCount, tempPath,
      logInfo $ "downloading chunk " <> tshow chunkNo <> " from " <> showServer server <> "..."
      chunkPath <- uniqueCombine encPath $ show chunkNo
      let chunkSpec = XFTPRcvChunkSpec chunkPath (unFileSize chunkSize) (unFileDigest digest)
-      withReconnect g a server retryCount $ \c -> downloadXFTPChunk g c replicaKey (unChunkReplicaId replicaId) chunkSpec
+      withReconnect a server retryCount $ \c -> downloadXFTPChunk g c replicaKey (unChunkReplicaId replicaId) chunkSpec
      logInfo $ "downloaded chunk " <> tshow chunkNo <> " to " <> T.pack chunkPath
      downloaded <- atomically . stateTVar downloadedChunks $ \cs ->
        let cs' = fromIntegral (unFileSize chunkSize) : cs in (sum cs', cs')
@@ -472,12 +472,12 @@ cliReceiveFile ReceiveOptions {fileDescription, filePath, retryCount, tempPath,
          ifM (doesDirectoryExist path) (uniqueCombine path name) $
            ifM (doesFileExist path) (throwError "File already exists") (pure path)
        _ -> (`uniqueCombine` name) . (</> "Downloads") =<< getHomeDirectory
-    acknowledgeFileChunk :: TVar ChaChaDRG -> XFTPClientAgent -> FileChunk -> ExceptT CLIError IO ()
-    acknowledgeFileChunk g a FileChunk {replicas = replica : _} = do
+    acknowledgeFileChunk :: XFTPClientAgent -> FileChunk -> ExceptT CLIError IO ()
+    acknowledgeFileChunk a FileChunk {replicas = replica : _} = do
      let FileChunkReplica {server, replicaId, replicaKey} = replica
-      c <- withRetry retryCount $ getXFTPServerClient g a server
+      c <- withRetry retryCount $ getXFTPServerClient a server
      withRetry retryCount $ ackXFTPChunk c replicaKey (unChunkReplicaId replicaId)
-    acknowledgeFileChunk _ _ _ = throwError $ CLIError "chunk has no replicas"
+    acknowledgeFileChunk _ _ = throwError $ CLIError "chunk has no replicas"

 printProgress :: String -> Int64 -> Int64 -> IO ()
 printProgress s part total = printNoNewLine $ s <> " " <> show ((part * 100) `div` total) <> "%"
@@ -501,8 +501,7 @@ cliDeleteFile DeleteOptions {fileDescription, retryCount, yes} = do
    deleteFileChunk :: XFTPClientAgent -> FileChunk -> ExceptT CLIError IO ()
    deleteFileChunk a FileChunk {chunkNo, replicas = replica : _} = do
      let FileChunkReplica {server, replicaId, replicaKey} = replica
-      g <- liftIO C.newRandom
-      withReconnect g a server retryCount $ \c -> deleteXFTPChunk c replicaKey (unChunkReplicaId replicaId)
+      withReconnect a server retryCount $ \c -> deleteXFTPChunk c replicaKey (unChunkReplicaId replicaId)
      logInfo $ "deleted chunk " <> tshow chunkNo <> " from " <> showServer server
    deleteFileChunk _ _ = throwError $ CLIError "chunk has no replicas"

@@ -570,9 +569,9 @@ prepareChunkSpecs filePath chunkSizes = reverse . snd $ foldl' addSpec (0, []) c
 getEncPath :: MonadIO m => Maybe FilePath -> String -> m FilePath
 getEncPath path name = (`uniqueCombine` (name <> ".encrypted")) =<< maybe (liftIO getCanonicalTemporaryDirectory) pure path

-withReconnect :: Show e => TVar ChaChaDRG -> XFTPClientAgent -> XFTPServer -> Int -> (XFTPClient -> ExceptT e IO a) -> ExceptT CLIError IO a
-withReconnect g a srv n run = withRetry n $ do
-  c <- withRetry n $ getXFTPServerClient g a srv
+withReconnect :: Show e => XFTPClientAgent -> XFTPServer -> Int -> (XFTPClient -> ExceptT e IO a) -> ExceptT CLIError IO a
+withReconnect a srv n run = withRetry n $ do
+  c <- withRetry n $ getXFTPServerClient a srv
  withExceptT (CLIError . show) (run c) `catchError` \e -> do
    liftIO $ closeXFTPServerClient a srv
    throwError e
@@ -48,7 +48,6 @@ import Simplex.Messaging.Protocol
    SndPublicAuthKey,
    Transmission,
    TransmissionForAuth (..),
-    CorrId (..),
    encodeTransmission,
    encodeTransmissionForAuth,
    messageTagP,
@@ -329,7 +328,7 @@ checkParty' c = case testEquality (sFileParty @p) (sFileParty @p') of
 xftpEncodeAuthTransmission :: ProtocolEncoding XFTPVersion e c => THandleParams XFTPVersion 'TClient -> C.APrivateAuthKey -> Transmission c -> Either TransportError ByteString
 xftpEncodeAuthTransmission thParams@THandleParams {thAuth} pKey (corrId, fId, msg) = do
  let TransmissionForAuth {tForAuth, tToSend} = encodeTransmissionForAuth thParams (corrId, fId, msg)
-  xftpEncodeBatch1 . (,tToSend) =<< authTransmission thAuth (Just pKey) (C.cbNonce $ bs corrId) tForAuth
+  xftpEncodeBatch1 . (,tToSend) =<< authTransmission thAuth (Just pKey) corrId tForAuth

 xftpEncodeTransmission :: ProtocolEncoding XFTPVersion e c => THandleParams XFTPVersion p -> Transmission c -> Either TransportError ByteString
 xftpEncodeTransmission thParams (corrId, fId, msg) = do
@@ -141,11 +141,11 @@ xftpServer cfg@XFTPServerConfig {xftpPort, transportConfig, inactiveClientExpira
        processClientHandshake pk = do
          unless (B.length bodyHead == xftpBlockSize) $ throwError HANDSHAKE
          body <- liftHS $ C.unPad bodyHead
-          XFTPClientHandshake {xftpVersion, keyHash, authPubKey} <- liftHS $ smpDecode body
+          XFTPClientHandshake {xftpVersion, keyHash} <- liftHS $ smpDecode body
          kh <- asks serverIdentity
          unless (keyHash == kh) $ throwError HANDSHAKE
          unless (xftpVersion `isCompatible` supportedFileServerVRange) $ throwError HANDSHAKE
-          let auth = THAuthServer {clientPeerPubKey = authPubKey, serverPrivKey = pk}
+          let auth = THAuthServer {serverPrivKey = pk, sessSecret' = Nothing}
          atomically $ TM.insert sessionId (HandshakeAccepted auth xftpVersion) sessions
          liftIO . sendResponse $ H.responseNoBody N.ok200 []
          pure Nothing
@@ -13,12 +13,9 @@ import Control.Logger.Simple
 import Control.Monad
 import Control.Monad.IO.Unlift
 import Crypto.Random
-import Data.Default (def)
 import Data.Int (Int64)
-import Data.List (find)
 import Data.List.NonEmpty (NonEmpty)
 import qualified Data.Map.Strict as M
-import Data.Maybe (fromMaybe)
 import Data.Time.Clock (getCurrentTime)
 import Data.Word (Word32)
 import Data.X509.Validation (Fingerprint (..))
@@ -103,7 +100,7 @@ supportedXFTPhandshakes :: [ALPN]
 supportedXFTPhandshakes = ["xftp/1"]

 newXFTPServerEnv :: XFTPServerConfig -> IO XFTPEnv
-newXFTPServerEnv config@XFTPServerConfig {storeLogFile, fileSizeQuota, caCertificateFile, certificateFile, privateKeyFile} = do
+newXFTPServerEnv config@XFTPServerConfig {storeLogFile, fileSizeQuota, caCertificateFile, certificateFile, privateKeyFile, transportConfig} = do
  random <- liftIO C.newRandom
  store <- atomically newFileStore
  storeLog <- liftIO $ mapM (`readWriteFileStore` store) storeLogFile
@@ -112,17 +109,7 @@ newXFTPServerEnv config@XFTPServerConfig {storeLogFile, fileSizeQuota, caCertifi
  forM_ fileSizeQuota $ \quota -> do
    logInfo $ "Total / available storage: " <> tshow quota <> " / " <> tshow (quota - used)
    when (quota < used) $ logInfo "WARNING: storage quota is less than used storage, no files can be uploaded!"
-  tlsServerParams' <- liftIO $ loadTLSServerParams caCertificateFile certificateFile privateKeyFile
-  let TransportServerConfig {alpn} = transportConfig config
-  let tlsServerParams = case alpn of
-        Nothing -> tlsServerParams'
-        Just supported ->
-          tlsServerParams'
-            { T.serverHooks =
-                def
-                  { T.onALPNClientSuggest = Just $ pure . fromMaybe "" . find (`elem` supported)
-                  }
-            }
+  tlsServerParams <- liftIO $ loadTLSServerParams caCertificateFile certificateFile privateKeyFile (alpn transportConfig)
  Fingerprint fp <- liftIO $ loadFingerprint caCertificateFile
  serverStats <- atomically . newFileServerStats =<< liftIO getCurrentTime
  pure XFTPEnv {config, store, storeLog, random, tlsServerParams, serverIdentity = C.KeyHash fp, serverStats}
@@ -19,7 +19,7 @@ import Options.Applicative
 import Simplex.FileTransfer.Chunks
 import Simplex.FileTransfer.Description (FileSize (..))
 import Simplex.FileTransfer.Server (runXFTPServer)
-import Simplex.FileTransfer.Server.Env (XFTPServerConfig (..), defFileExpirationHours, defaultFileExpiration, defaultInactiveClientExpiration)
+import Simplex.FileTransfer.Server.Env (XFTPServerConfig (..), defFileExpirationHours, defaultFileExpiration, defaultInactiveClientExpiration, supportedXFTPhandshakes)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol (ProtoServerWithAuth (..), pattern XFTPServer)
@@ -180,7 +180,8 @@ xftpServerCLI cfgPath logPath = do
              serverStatsBackupFile = logStats $> combine logPath "file-server-stats.log",
              transportConfig =
                defaultTransportServerConfig
-                  { logTLSErrors = fromMaybe False $ iniOnOff "TRANSPORT" "log_tls_errors" ini
+                  { logTLSErrors = fromMaybe False $ iniOnOff "TRANSPORT" "log_tls_errors" ini,
+                    alpn = Just supportedXFTPhandshakes
                  }
            }

@@ -10,6 +10,7 @@

 module Simplex.FileTransfer.Transport
  ( supportedFileServerVRange,
+    authCmdsXFTPVersion,
    xftpClientHandshakeStub,
    XFTPClientHandshake (..),
    -- xftpClientHandshake,
@@ -83,14 +84,17 @@ type THandleParamsXFTP p = THandleParams XFTPVersion p
 initialXFTPVersion :: VersionXFTP
 initialXFTPVersion = VersionXFTP 1

+authCmdsXFTPVersion :: VersionXFTP
+authCmdsXFTPVersion = VersionXFTP 2
+
 currentXFTPVersion :: VersionXFTP
 currentXFTPVersion = VersionXFTP 2

 supportedFileServerVRange :: VersionRangeXFTP
 supportedFileServerVRange = mkVersionRange initialXFTPVersion currentXFTPVersion

-- XFTP protocol does not support handshake
-xftpClientHandshakeStub :: c -> C.KeyPairX25519 -> C.KeyHash -> VersionRangeXFTP -> ExceptT TransportError IO (THandle XFTPVersion c 'TClient)
+-- XFTP protocol does not use this handshake method
+xftpClientHandshakeStub :: c -> Maybe C.KeyPairX25519 -> C.KeyHash -> VersionRangeXFTP -> ExceptT TransportError IO (THandle XFTPVersion c 'TClient)
 xftpClientHandshakeStub _c _ks _keyHash _xftpVRange = throwError $ TEHandshake VERSION

 data XFTPServerHandshake = XFTPServerHandshake
@@ -104,19 +108,16 @@ data XFTPClientHandshake = XFTPClientHandshake
  { -- | agreed XFTP server protocol version
    xftpVersion :: VersionXFTP,
    -- | server identity - CA certificate fingerprint
-    keyHash :: C.KeyHash,
-    -- | pub key to agree shared secret for entity ID encryption, shared secret for command authorization is agreed using per-queue keys.
-    authPubKey :: C.PublicKeyX25519
+    keyHash :: C.KeyHash
  }

 instance Encoding XFTPClientHandshake where
-  smpEncode XFTPClientHandshake {xftpVersion, keyHash, authPubKey} =
-    smpEncode (xftpVersion, keyHash, authPubKey)
+  smpEncode XFTPClientHandshake {xftpVersion, keyHash} =
+    smpEncode (xftpVersion, keyHash)
  smpP = do
    (xftpVersion, keyHash) <- smpP
-    authPubKey <- smpP
    Tail _compat <- smpP
-    pure XFTPClientHandshake {xftpVersion, keyHash, authPubKey}
+    pure XFTPClientHandshake {xftpVersion, keyHash}

 instance Encoding XFTPServerHandshake where
  smpEncode XFTPServerHandshake {xftpVersionRange, sessionId, authPubKey} =
@@ -55,6 +55,7 @@ module Simplex.Messaging.Agent
    deleteConnectionAsync,
    deleteConnectionsAsync,
    createConnection,
+    prepareConnectionToJoin,
    joinConnection,
    allowConnection,
    acceptContact,
@@ -149,7 +150,7 @@ import Simplex.FileTransfer.Protocol (FileParty (..))
 import Simplex.FileTransfer.Util (removePath)
 import Simplex.Messaging.Agent.Client
 import Simplex.Messaging.Agent.Env.SQLite
-import Simplex.Messaging.Agent.Lock (withLock', withLock)
+import Simplex.Messaging.Agent.Lock (withLock, withLock')
 import Simplex.Messaging.Agent.NtfSubSupervisor
 import Simplex.Messaging.Agent.Protocol
 import Simplex.Messaging.Agent.RetryInterval
@@ -160,7 +161,7 @@ import qualified Simplex.Messaging.Agent.Store.SQLite.Migrations as Migrations
 import Simplex.Messaging.Client (ProtocolClient (..), ServerTransmission)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Crypto.File (CryptoFile, CryptoFileArgs)
-import Simplex.Messaging.Crypto.Ratchet (PQEncryption, PQSupport (..), pattern PQEncOn, pattern PQEncOff, pattern PQSupportOn, pattern PQSupportOff)
+import Simplex.Messaging.Crypto.Ratchet (PQEncryption, PQSupport (..), pattern PQEncOff, pattern PQEncOn, pattern PQSupportOff, pattern PQSupportOn)
 import qualified Simplex.Messaging.Crypto.Ratchet as CR
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String
@@ -198,7 +199,7 @@ getSMPAgentClient_ clientId cfg initServers store backgroundMode =
  liftIO $ newSMPAgentEnv cfg store >>= runReaderT runAgent
  where
    runAgent = do
-      c@AgentClient {acThread}  <- atomically . newAgentClient clientId initServers =<< ask
+      c@AgentClient {acThread} <- atomically . newAgentClient clientId initServers =<< ask
      t <- runAgentThreads c `forkFinally` const (liftIO $ disconnectAgentClient c)
      atomically . writeTVar acThread . Just =<< mkWeakThreadId t
      pure c
@@ -239,7 +240,7 @@ createUser c = withAgentEnv c .: createUser' c
 {-# INLINE createUser #-}

 -- | Delete user record optionally deleting all user's connections on SMP servers
-deleteUser :: AgentClient -> UserId -> Bool -> AE  ()
+deleteUser :: AgentClient -> UserId -> Bool -> AE ()
 deleteUser c = withAgentEnv c .: deleteUser' c
 {-# INLINE deleteUser #-}

@@ -288,9 +289,18 @@ createConnection :: AgentClient -> UserId -> Bool -> SConnectionMode c -> Maybe
 createConnection c userId enableNtfs = withAgentEnv c .:: newConn c userId "" enableNtfs
 {-# INLINE createConnection #-}

-- | Join SMP agent connection (JOIN command)
-joinConnection :: AgentClient -> UserId -> Bool -> ConnectionRequestUri c -> ConnInfo -> PQSupport -> SubscriptionMode -> AE ConnId
-joinConnection c userId enableNtfs = withAgentEnv c .:: joinConn c userId "" enableNtfs
+-- | Create SMP agent connection without queue (to be joined with joinConnection passing connection ID).
+-- This method is required to prevent race condition when confirmation from peer is received before
+-- the caller of joinConnection saves connection ID to the database.
+-- Instead of it we could send confirmation asynchronously, but then it would be harder to report
+-- "link deleted" (SMP AUTH) interactively, so this approach is simpler overall.
+prepareConnectionToJoin :: AgentClient -> UserId -> Bool -> ConnectionRequestUri c -> PQSupport -> AE ConnId
+prepareConnectionToJoin c userId enableNtfs = withAgentEnv c .: newConnToJoin c userId "" enableNtfs
+
+-- | Join SMP agent connection (JOIN command).
+joinConnection :: AgentClient -> UserId -> Maybe ConnId -> Bool -> ConnectionRequestUri c -> ConnInfo -> PQSupport -> SubscriptionMode -> AE ConnId
+joinConnection c userId Nothing enableNtfs = withAgentEnv c .:: joinConn c userId "" False enableNtfs
+joinConnection c userId (Just connId) enableNtfs = withAgentEnv c .:: joinConn c userId connId True enableNtfs
 {-# INLINE joinConnection #-}

 -- | Allow connection to continue after CONF notification (LET command)
@@ -575,7 +585,7 @@ processCommand :: AgentClient -> (EntityId, APartyCmd 'Client) -> AM (EntityId,
 processCommand c (connId, APC e cmd) =
  second (APC e) <$> case cmd of
    NEW enableNtfs (ACM cMode) pqIK subMode -> second (INV . ACR cMode) <$> newConn c userId connId enableNtfs cMode Nothing pqIK subMode
-    JOIN enableNtfs (ACR _ cReq) pqEnc subMode connInfo -> (,OK) <$> joinConn c userId connId enableNtfs cReq connInfo pqEnc subMode
+    JOIN enableNtfs (ACR _ cReq) pqEnc subMode connInfo -> (,OK) <$> joinConn c userId connId False enableNtfs cReq connInfo pqEnc subMode
    LET confId ownCInfo -> allowConnection' c connId confId ownCInfo $> (connId, OK)
    ACPT invId pqEnc ownCInfo -> (,OK) <$> acceptContact' c connId True invId ownCInfo pqEnc SMSubscribe
    RJCT invId -> rejectContact' c connId invId $> (connId, OK)
@@ -618,14 +628,14 @@ newConnAsync c userId corrId enableNtfs cMode pqInitKeys subMode = do
 newConnNoQueues :: AgentClient -> UserId -> ConnId -> Bool -> SConnectionMode c -> PQSupport -> AM ConnId
 newConnNoQueues c userId connId enableNtfs cMode pqSupport = do
  g <- asks random
-  connAgentVersion <- asks $ maxVersion . ($ pqSupport) . smpAgentVRange . config
+  connAgentVersion <- asks $ maxVersion . smpAgentVRange . config
  let cData = ConnData {userId, connId, connAgentVersion, enableNtfs, lastExternalSndId = 0, deleted = False, ratchetSyncState = RSOk, pqSupport}
  withStore c $ \db -> createNewConn db g cData cMode

 joinConnAsync :: AgentClient -> UserId -> ACorrId -> Bool -> ConnectionRequestUri c -> ConnInfo -> PQSupport -> SubscriptionMode -> AM ConnId
 joinConnAsync c userId corrId enableNtfs cReqUri@CRInvitationUri {} cInfo pqSup subMode = do
  withInvLock c (strEncode cReqUri) "joinConnAsync" $ do
-    lift (compatibleInvitationUri cReqUri pqSup) >>= \case
+    lift (compatibleInvitationUri cReqUri) >>= \case
      Just (_, Compatible (CR.E2ERatchetParams v _ _ _), Compatible connAgentVersion) -> do
        g <- asks random
        let pqSupport = pqSup `CR.pqSupportAnd` versionPQSupport_ connAgentVersion (Just v)
@@ -708,11 +718,14 @@ switchConnectionAsync' c corrId connId =

 newConn :: AgentClient -> UserId -> ConnId -> Bool -> SConnectionMode c -> Maybe CRClientData -> CR.InitialKeys -> SubscriptionMode -> AM (ConnId, ConnectionRequestUri c)
 newConn c userId connId enableNtfs cMode clientData pqInitKeys subMode =
-  getSMPServer c userId >>= newConnSrv c userId connId enableNtfs cMode clientData pqInitKeys subMode
+  getSMPServer c userId >>= newConnSrv c userId connId False enableNtfs cMode clientData pqInitKeys subMode

-newConnSrv :: AgentClient -> UserId -> ConnId -> Bool -> SConnectionMode c -> Maybe CRClientData -> CR.InitialKeys -> SubscriptionMode -> SMPServerWithAuth -> AM (ConnId, ConnectionRequestUri c)
-newConnSrv c userId connId enableNtfs cMode clientData pqInitKeys subMode srv = do
-  connId' <- newConnNoQueues c userId connId enableNtfs cMode (CR.connPQEncryption pqInitKeys)
+newConnSrv :: AgentClient -> UserId -> ConnId -> Bool -> Bool -> SConnectionMode c -> Maybe CRClientData -> CR.InitialKeys -> SubscriptionMode -> SMPServerWithAuth -> AM (ConnId, ConnectionRequestUri c)
+newConnSrv c userId connId hasNewConn enableNtfs cMode clientData pqInitKeys subMode srv = do
+  connId' <-
+    if hasNewConn
+      then pure connId
+      else newConnNoQueues c userId connId enableNtfs cMode (CR.connPQEncryption pqInitKeys)
  newRcvConnSrv c userId connId' enableNtfs cMode clientData pqInitKeys subMode srv

 newRcvConnSrv :: AgentClient -> UserId -> ConnId -> Bool -> SConnectionMode c -> Maybe CRClientData -> CR.InitialKeys -> SubscriptionMode -> SMPServerWithAuth -> AM (ConnId, ConnectionRequestUri c)
@@ -729,99 +742,118 @@ newRcvConnSrv c userId connId enableNtfs cMode clientData pqInitKeys subMode srv
  when enableNtfs $ do
    ns <- asks ntfSupervisor
    atomically $ sendNtfSubCommand ns (connId, NSCCreate)
-  let pqEnc = CR.connPQEncryption pqInitKeys
-      crData = ConnReqUriData SSSimplex (smpAgentVRange pqEnc) [qUri] clientData
-      e2eVRange = e2eEncryptVRange pqEnc
+  let crData = ConnReqUriData SSSimplex smpAgentVRange [qUri] clientData
  case cMode of
    SCMContact -> pure (connId, CRContactUri crData)
    SCMInvitation -> do
      g <- asks random
-      (pk1, pk2, pKem, e2eRcvParams) <- liftIO $ CR.generateRcvE2EParams g (maxVersion e2eVRange) (CR.initialPQEncryption pqInitKeys)
+      (pk1, pk2, pKem, e2eRcvParams) <- liftIO $ CR.generateRcvE2EParams g (maxVersion e2eEncryptVRange) (CR.initialPQEncryption pqInitKeys)
      withStore' c $ \db -> createRatchetX3dhKeys db connId pk1 pk2 pKem
-      pure (connId, CRInvitationUri crData $ toVersionRangeT e2eRcvParams e2eVRange)
+      pure (connId, CRInvitationUri crData $ toVersionRangeT e2eRcvParams e2eEncryptVRange)

-joinConn :: AgentClient -> UserId -> ConnId -> Bool -> ConnectionRequestUri c -> ConnInfo -> PQSupport -> SubscriptionMode -> AM ConnId
-joinConn c userId connId enableNtfs cReq cInfo pqSupport subMode = do
+newConnToJoin :: forall c. AgentClient -> UserId -> ConnId -> Bool -> ConnectionRequestUri c -> PQSupport -> AM ConnId
+newConnToJoin c userId connId enableNtfs cReq pqSup = case cReq of
+  CRInvitationUri {} ->
+    lift (compatibleInvitationUri cReq) >>= \case
+      Just (_, (Compatible (CR.E2ERatchetParams v _ _ _)), aVersion) -> create aVersion (Just v)
+      Nothing -> throwError $ AGENT A_VERSION
+  CRContactUri {} ->
+    lift (compatibleContactUri cReq) >>= \case
+      Just (_, aVersion) -> create aVersion Nothing
+      Nothing -> throwError $ AGENT A_VERSION
+  where
+    create :: Compatible VersionSMPA -> Maybe CR.VersionE2E -> AM ConnId
+    create (Compatible connAgentVersion) e2eV_ = do
+      g <- asks random
+      let pqSupport = pqSup `CR.pqSupportAnd` versionPQSupport_ connAgentVersion e2eV_
+          cData = ConnData {userId, connId, connAgentVersion, enableNtfs, lastExternalSndId = 0, deleted = False, ratchetSyncState = RSOk, pqSupport}
+      withStore c $ \db -> createNewConn db g cData SCMInvitation
+
+joinConn :: AgentClient -> UserId -> ConnId -> Bool -> Bool -> ConnectionRequestUri c -> ConnInfo -> PQSupport -> SubscriptionMode -> AM ConnId
+joinConn c userId connId hasNewConn enableNtfs cReq cInfo pqSupport subMode = do
  srv <- case cReq of
    CRInvitationUri ConnReqUriData {crSmpQueues = q :| _} _ ->
      getNextServer c userId [qServer q]
    _ -> getSMPServer c userId
-  joinConnSrv c userId connId enableNtfs cReq cInfo pqSupport subMode srv
+  joinConnSrv c userId connId hasNewConn enableNtfs cReq cInfo pqSupport subMode srv

-startJoinInvitation :: UserId -> ConnId -> Bool -> ConnectionRequestUri 'CMInvitation -> PQSupport -> AM (Compatible VersionSMPA, ConnData, NewSndQueue, CR.Ratchet 'C.X448, CR.SndE2ERatchetParams 'C.X448)
+startJoinInvitation :: UserId -> ConnId -> Bool -> ConnectionRequestUri 'CMInvitation -> PQSupport -> AM (ConnData, NewSndQueue, CR.Ratchet 'C.X448, CR.SndE2ERatchetParams 'C.X448)
 startJoinInvitation userId connId enableNtfs cReqUri pqSup =
-  lift (compatibleInvitationUri cReqUri pqSup) >>= \case
-    Just (qInfo, (Compatible e2eRcvParams@(CR.E2ERatchetParams v _ rcDHRr kem_)), aVersion@(Compatible connAgentVersion)) -> do
+  lift (compatibleInvitationUri cReqUri) >>= \case
+    Just (qInfo, (Compatible e2eRcvParams@(CR.E2ERatchetParams v _ rcDHRr kem_)), Compatible connAgentVersion) -> do
      g <- asks random
      let pqSupport = pqSup `CR.pqSupportAnd` versionPQSupport_ connAgentVersion (Just v)
      (pk1, pk2, pKem, e2eSndParams) <- liftIO $ CR.generateSndE2EParams g v (CR.replyKEM_ v kem_ pqSupport)
      (_, rcDHRs) <- atomically $ C.generateKeyPair g
      rcParams <- liftEitherWith cryptoError $ CR.pqX3dhSnd pk1 pk2 pKem e2eRcvParams
-      maxSupported <- asks $ maxVersion . ($ pqSup) . e2eEncryptVRange . config
+      maxSupported <- asks $ maxVersion . e2eEncryptVRange . config
      let rcVs = CR.RatchetVersions {current = v, maxSupported}
          rc = CR.initSndRatchet rcVs rcDHRr rcDHRs rcParams
      q <- lift $ newSndQueue userId "" qInfo
      let cData = ConnData {userId, connId, connAgentVersion, enableNtfs, lastExternalSndId = 0, deleted = False, ratchetSyncState = RSOk, pqSupport}
-      pure (aVersion, cData, q, rc, e2eSndParams)
+      pure (cData, q, rc, e2eSndParams)
    Nothing -> throwError $ AGENT A_VERSION

 connRequestPQSupport :: AgentClient -> PQSupport -> ConnectionRequestUri c -> IO (Maybe (VersionSMPA, PQSupport))
 connRequestPQSupport c pqSup cReq = withAgentEnv' c $ case cReq of
-  CRInvitationUri {} -> invPQSupported <$$> compatibleInvitationUri cReq pqSup
+  CRInvitationUri {} -> invPQSupported <$$> compatibleInvitationUri cReq
    where
      invPQSupported (_, Compatible (CR.E2ERatchetParams e2eV _ _ _), Compatible agentV) = (agentV, pqSup `CR.pqSupportAnd` versionPQSupport_ agentV (Just e2eV))
-  CRContactUri {} -> ctPQSupported <$$> compatibleContactUri cReq pqSup
+  CRContactUri {} -> ctPQSupported <$$> compatibleContactUri cReq
    where
      ctPQSupported (_, Compatible agentV) = (agentV, pqSup `CR.pqSupportAnd` versionPQSupport_ agentV Nothing)

-compatibleInvitationUri :: ConnectionRequestUri 'CMInvitation -> PQSupport -> AM' (Maybe (Compatible SMPQueueInfo, Compatible (CR.RcvE2ERatchetParams 'C.X448), Compatible VersionSMPA))
-compatibleInvitationUri (CRInvitationUri ConnReqUriData {crAgentVRange, crSmpQueues = (qUri :| _)} e2eRcvParamsUri) pqSup = do
+compatibleInvitationUri :: ConnectionRequestUri 'CMInvitation -> AM' (Maybe (Compatible SMPQueueInfo, Compatible (CR.RcvE2ERatchetParams 'C.X448), Compatible VersionSMPA))
+compatibleInvitationUri (CRInvitationUri ConnReqUriData {crAgentVRange, crSmpQueues = (qUri :| _)} e2eRcvParamsUri) = do
  AgentConfig {smpClientVRange, smpAgentVRange, e2eEncryptVRange} <- asks config
  pure $
    (,,)
      <$> (qUri `compatibleVersion` smpClientVRange)
-      <*> (e2eRcvParamsUri `compatibleVersion` e2eEncryptVRange pqSup)
-      <*> (crAgentVRange `compatibleVersion` smpAgentVRange pqSup)
+      <*> (e2eRcvParamsUri `compatibleVersion` e2eEncryptVRange)
+      <*> (crAgentVRange `compatibleVersion` smpAgentVRange)

-compatibleContactUri :: ConnectionRequestUri 'CMContact -> PQSupport -> AM' (Maybe (Compatible SMPQueueInfo, Compatible VersionSMPA))
-compatibleContactUri (CRContactUri ConnReqUriData {crAgentVRange, crSmpQueues = (qUri :| _)}) pqSup = do
+compatibleContactUri :: ConnectionRequestUri 'CMContact -> AM' (Maybe (Compatible SMPQueueInfo, Compatible VersionSMPA))
+compatibleContactUri (CRContactUri ConnReqUriData {crAgentVRange, crSmpQueues = (qUri :| _)}) = do
  AgentConfig {smpClientVRange, smpAgentVRange} <- asks config
  pure $
    (,)
      <$> (qUri `compatibleVersion` smpClientVRange)
-      <*> (crAgentVRange `compatibleVersion` smpAgentVRange pqSup)
+      <*> (crAgentVRange `compatibleVersion` smpAgentVRange)

 versionPQSupport_ :: VersionSMPA -> Maybe CR.VersionE2E -> PQSupport
 versionPQSupport_ agentV e2eV_ = PQSupport $ agentV >= pqdrSMPAgentVersion && maybe True (>= CR.pqRatchetE2EEncryptVersion) e2eV_
 {-# INLINE versionPQSupport_ #-}

-joinConnSrv :: AgentClient -> UserId -> ConnId -> Bool -> ConnectionRequestUri c -> ConnInfo -> PQSupport -> SubscriptionMode -> SMPServerWithAuth -> AM ConnId
-joinConnSrv c userId connId enableNtfs inv@CRInvitationUri {} cInfo pqSup subMode srv =
+joinConnSrv :: AgentClient -> UserId -> ConnId -> Bool -> Bool -> ConnectionRequestUri c -> ConnInfo -> PQSupport -> SubscriptionMode -> SMPServerWithAuth -> AM ConnId
+joinConnSrv c userId connId hasNewConn enableNtfs inv@CRInvitationUri {} cInfo pqSup subMode srv =
  withInvLock c (strEncode inv) "joinConnSrv" $ do
-    (aVersion, cData, q, rc, e2eSndParams) <- startJoinInvitation userId connId enableNtfs inv pqSup
+    (cData, q, rc, e2eSndParams) <- startJoinInvitation userId connId enableNtfs inv pqSup
    g <- asks random
    (connId', sq) <- withStore c $ \db -> runExceptT $ do
-      r@(connId', _) <- ExceptT $ createSndConn db g cData q
+      r@(connId', _) <-
+        if hasNewConn
+          then (connId,) <$> ExceptT (updateNewConnSnd db connId q)
+          else ExceptT $ createSndConn db g cData q
      liftIO $ createRatchet db connId' rc
      pure r
    let cData' = (cData :: ConnData) {connId = connId'}
-    tryError (confirmQueue aVersion c cData' sq srv cInfo (Just e2eSndParams) subMode) >>= \case
+    tryError (confirmQueue c cData' sq srv cInfo (Just e2eSndParams) subMode) >>= \case
      Right _ -> pure connId'
      Left e -> do
        -- possible improvement: recovery for failure on network timeout, see rfcs/2022-04-20-smp-conf-timeout-recovery.md
        void $ withStore' c $ \db -> deleteConn db Nothing connId'
        throwError e
-joinConnSrv c userId connId enableNtfs cReqUri@CRContactUri {} cInfo pqSup subMode srv =
-  lift (compatibleContactUri cReqUri pqSup) >>= \case
+joinConnSrv c userId connId hasNewConn enableNtfs cReqUri@CRContactUri {} cInfo pqSup subMode srv =
+  lift (compatibleContactUri cReqUri) >>= \case
    Just (qInfo, vrsn) -> do
-      (connId', cReq) <- newConnSrv c userId connId enableNtfs SCMInvitation Nothing (CR.IKNoPQ pqSup) subMode srv
+      (connId', cReq) <- newConnSrv c userId connId hasNewConn enableNtfs SCMInvitation Nothing (CR.IKNoPQ pqSup) subMode srv
      sendInvitation c userId qInfo vrsn cReq cInfo
      pure connId'
    Nothing -> throwError $ AGENT A_VERSION

 joinConnSrvAsync :: AgentClient -> UserId -> ConnId -> Bool -> ConnectionRequestUri c -> ConnInfo -> PQSupport -> SubscriptionMode -> SMPServerWithAuth -> AM ()
 joinConnSrvAsync c userId connId enableNtfs inv@CRInvitationUri {} cInfo pqSupport subMode srv = do
-  (_aVersion, cData, q, rc, e2eSndParams) <- startJoinInvitation userId connId enableNtfs inv pqSupport
+  (cData, q, rc, e2eSndParams) <- startJoinInvitation userId connId enableNtfs inv pqSupport
  q' <- withStore c $ \db -> runExceptT $ do
    liftIO $ createRatchet db connId rc
    ExceptT $ updateNewConnSnd db connId q
@@ -863,7 +895,7 @@ acceptContact' c connId enableNtfs invId ownConnInfo pqSupport subMode = withCon
  withStore c (`getConn` contactConnId) >>= \case
    SomeConn _ (ContactConnection ConnData {userId} _) -> do
      withStore' c $ \db -> acceptInvitation db invId ownConnInfo
-      joinConn c userId connId enableNtfs connReq ownConnInfo pqSupport subMode `catchAgentError` \err -> do
+      joinConn c userId connId False enableNtfs connReq ownConnInfo pqSupport subMode `catchAgentError` \err -> do
        withStore' c (`unacceptInvitation` invId)
        throwError err
    _ -> throwError $ CMD PROHIBITED
@@ -1209,7 +1241,7 @@ enqueueMessage c cData sq msgFlags aMessage =
 {-# INLINE enqueueMessage #-}

 -- this function is used only for sending messages in batch, it returns the list of successes to enqueue additional deliveries
-enqueueMessageB :: forall t. (Traversable t) => AgentClient -> t (Either AgentErrorType (ConnData, NonEmpty SndQueue, Maybe PQEncryption, MsgFlags, AMessage)) -> AM' (t (Either AgentErrorType ((AgentMsgId, PQEncryption), Maybe (ConnData, [SndQueue], AgentMsgId))))
+enqueueMessageB :: forall t. Traversable t => AgentClient -> t (Either AgentErrorType (ConnData, NonEmpty SndQueue, Maybe PQEncryption, MsgFlags, AMessage)) -> AM' (t (Either AgentErrorType ((AgentMsgId, PQEncryption), Maybe (ConnData, [SndQueue], AgentMsgId))))
 enqueueMessageB c reqs = do
  cfg <- asks config
  reqMids <- withStoreBatch c $ \db -> fmap (bindRight $ storeSentMsg db cfg) reqs
@@ -1219,7 +1251,7 @@ enqueueMessageB c reqs = do
    pure $ Right ((msgId, pqSecr), if null sqs' then Nothing else Just (cData, sqs', msgId))
  where
    storeSentMsg :: DB.Connection -> AgentConfig -> (ConnData, NonEmpty SndQueue, Maybe PQEncryption, MsgFlags, AMessage) -> IO (Either AgentErrorType ((ConnData, NonEmpty SndQueue, Maybe PQEncryption, MsgFlags, AMessage), InternalId, PQEncryption))
-    storeSentMsg db cfg req@(cData@ConnData {connId, pqSupport}, sq :| _, pqEnc_, msgFlags, aMessage) = fmap (first storeError) $ runExceptT $ do
+    storeSentMsg db cfg req@(cData@ConnData {connId}, sq :| _, pqEnc_, msgFlags, aMessage) = fmap (first storeError) $ runExceptT $ do
      let AgentConfig {smpAgentVRange, e2eEncryptVRange} = cfg
      internalTs <- liftIO getCurrentTime
      (internalId, internalSndId, prevMsgHash) <- liftIO $ updateSndIds db connId
@@ -1227,10 +1259,9 @@ enqueueMessageB c reqs = do
          agentMsg = AgentMessage privHeader aMessage
          agentMsgStr = smpEncode agentMsg
          internalHash = C.sha256Hash agentMsgStr
-          currentE2EVersion = maxVersion $ e2eEncryptVRange PQSupportOff
-      (encAgentMessage, pqEnc) <- agentRatchetEncrypt db cData agentMsgStr e2eEncUserMsgLength pqEnc_ currentE2EVersion
-      -- agent version range is determined by the connection suppport of PQ encryption, that is may be enabled when message is sent
-      let agentVersion = maxVersion $ smpAgentVRange pqSupport
+          currentE2EVersion = maxVersion e2eEncryptVRange
+      (encAgentMessage, pqEnc) <- agentRatchetEncrypt db cData agentMsgStr e2eEncAgentMsgLength pqEnc_ currentE2EVersion
+      let agentVersion = maxVersion smpAgentVRange
          msgBody = smpEncode $ AgentMsgEnvelope {agentVersion, encAgentMessage}
          msgType = agentMessageType agentMsg
          msgData = SndMsgData {internalId, internalSndId, internalTs, msgType, msgFlags, msgBody, pqEncryption = pqEnc, internalHash, prevMsgHash}
@@ -1242,7 +1273,7 @@ enqueueSavedMessage :: AgentClient -> ConnData -> AgentMsgId -> SndQueue -> AM'
 enqueueSavedMessage c cData msgId sq = enqueueSavedMessageB c $ Identity (cData, [sq], msgId)
 {-# INLINE enqueueSavedMessage #-}

-enqueueSavedMessageB :: (Foldable t) => AgentClient -> t (ConnData, [SndQueue], AgentMsgId) -> AM' ()
+enqueueSavedMessageB :: Foldable t => AgentClient -> t (ConnData, [SndQueue], AgentMsgId) -> AM' ()
 enqueueSavedMessageB c reqs = do
  -- saving to the database is in the start to avoid race conditions when delivery is read from queue before it is saved
  void $ withStoreBatch' c $ \db -> concatMap (storeDeliveries db) reqs
@@ -1520,7 +1551,7 @@ synchronizeRatchet' c connId pqSupport' force = withConnLock c connId "synchroni
          let cData' = cData {pqSupport = pqSupport'} :: ConnData
          AgentConfig {e2eEncryptVRange} <- asks config
          g <- asks random
-          (pk1, pk2, pKem, e2eParams) <- liftIO $ CR.generateRcvE2EParams g (maxVersion $ e2eEncryptVRange pqSupport') pqSupport'
+          (pk1, pk2, pKem, e2eParams) <- liftIO $ CR.generateRcvE2EParams g (maxVersion e2eEncryptVRange) pqSupport'
          enqueueRatchetKeyMsgs c cData' sqs e2eParams
          withStore' c $ \db -> do
            setConnRatchetSync db connId RSStarted
@@ -2046,7 +2077,7 @@ data ACKd = ACKd | ACKPending
 -- | make sure to ACK or throw in each message processing branch
 -- it cannot be finally, unfortunately, as sometimes it needs to be ACK+DEL
 processSMPTransmission :: AgentClient -> ServerTransmission SMPVersion BrokerMsg -> AM ()
-processSMPTransmission c@AgentClient {smpClients, subQ} (tSess@(_, srv, _), _v, sessId, rId, cmd) = do
+processSMPTransmission c@AgentClient {smpClients, subQ} (tSess@(_, srv, _), _v, sessId, isResponse, rId, cmd) = do
  (rq, SomeConn _ conn) <- withStore c (\db -> getRcvConn db srv rId)
  processSMP rq conn $ toConnData conn
  where
@@ -2189,8 +2220,8 @@ processSMPTransmission c@AgentClient {smpClients, subQ} (tSess@(_, srv, _), _v,
                      _ -> prohibited >> ack
                  _ -> prohibited >> ack
              updateConnVersion :: Connection c -> ConnData -> VersionSMPA -> AM (Connection c)
-              updateConnVersion conn' cData'@ConnData {pqSupport} msgAgentVersion = do
-                aVRange <- asks $ ($ pqSupport) . smpAgentVRange . config
+              updateConnVersion conn' cData' msgAgentVersion = do
+                aVRange <- asks $ smpAgentVRange . config
                let msgAVRange = fromMaybe (versionToRange msgAgentVersion) $ safeVersionRange (minVersion aVRange) msgAgentVersion
                case msgAVRange `compatibleVersion` aVRange of
                  Just (Compatible av)
@@ -2221,7 +2252,7 @@ processSMPTransmission c@AgentClient {smpClients, subQ} (tSess@(_, srv, _), _v,
              ignored = pure "END from disconnected client - ignored"
          _ -> do
            logServer "<--" c srv rId $ "unexpected: " <> bshow cmd
-            notify . ERR $ BROKER (B.unpack $ strEncode srv) UNEXPECTED
+            notify . ERR $ BROKER (B.unpack $ strEncode srv) $ if isResponse then TIMEOUT else UNEXPECTED
        where
          notify :: forall e m. MonadIO m => AEntityI e => ACommand 'Agent e -> m ()
          notify = atomically . notify'
@@ -2256,19 +2287,17 @@ processSMPTransmission c@AgentClient {smpClients, subQ} (tSess@(_, srv, _), _v,
            logServer "<--" c srv rId $ "MSG <CONF>:" <> logSecret srvMsgId
            AgentConfig {smpClientVRange, smpAgentVRange, e2eEncryptVRange} <- asks config
            let ConnData {pqSupport} = toConnData conn'
-                aVRange = smpAgentVRange pqSupport
-                e2eVRange = e2eEncryptVRange pqSupport
            unless
-              (agentVersion `isCompatible` aVRange && smpClientVersion `isCompatible` smpClientVRange)
+              (agentVersion `isCompatible` smpAgentVRange && smpClientVersion `isCompatible` smpClientVRange)
              (throwError $ AGENT A_VERSION)
            case status of
              New -> case (conn', e2eEncryption) of
                -- party initiating connection
                (RcvConnection _ _, Just (CR.AE2ERatchetParams _ e2eSndParams@(CR.E2ERatchetParams e2eVersion _ _ _))) -> do
-                  unless (e2eVersion `isCompatible` e2eVRange) (throwError $ AGENT A_VERSION)
+                  unless (e2eVersion `isCompatible` e2eEncryptVRange) (throwError $ AGENT A_VERSION)
                  (pk1, rcDHRs, pKem) <- withStore c (`getRatchetX3dhKeys` connId)
                  rcParams <- liftError cryptoError $ CR.pqX3dhRcv pk1 rcDHRs pKem e2eSndParams
-                  let rcVs = CR.RatchetVersions {current = e2eVersion, maxSupported = maxVersion e2eVRange}
+                  let rcVs = CR.RatchetVersions {current = e2eVersion, maxSupported = maxVersion e2eEncryptVRange}
                      pqSupport' = pqSupport `CR.pqSupportAnd` versionPQSupport_ agentVersion (Just e2eVersion)
                      rc = CR.initRcvRatchet rcVs rcDHRs rcParams pqSupport'
                  g <- asks random
@@ -2450,7 +2479,7 @@ processSMPTransmission c@AgentClient {smpClients, subQ} (tSess@(_, srv, _), _v,
              ContactConnection {} -> do
                -- show connection request even if invitaion via contact address is not compatible.
                -- in case invitation not compatible, assume there is no PQ encryption support.
-                pqSupport <- lift $ maybe PQSupportOff pqSupported <$> compatibleInvitationUri connReq PQSupportOn
+                pqSupport <- lift $ maybe PQSupportOff pqSupported <$> compatibleInvitationUri connReq
                g <- asks random
                let newInv = NewInvitation {contactConnId = connId, connReq, recipientConnInfo = cInfo}
                invId <- withStore c $ \db -> createInvitation db g newInv
@@ -2470,10 +2499,9 @@ processSMPTransmission c@AgentClient {smpClients, subQ} (tSess@(_, srv, _), _v,
          newRatchetKey e2eOtherPartyParams@(CR.E2ERatchetParams e2eVersion k1Rcv k2Rcv _) conn'@(DuplexConnection cData'@ConnData {lastExternalSndId, pqSupport} _ sqs) =
            unlessM ratchetExists $ do
              AgentConfig {e2eEncryptVRange} <- asks config
-              let connE2EVRange = e2eEncryptVRange pqSupport
-              unless (e2eVersion `isCompatible` connE2EVRange) (throwError $ AGENT A_VERSION)
+              unless (e2eVersion `isCompatible` e2eEncryptVRange) (throwError $ AGENT A_VERSION)
              keys <- getSendRatchetKeys
-              let rcVs = CR.RatchetVersions {current = e2eVersion, maxSupported = maxVersion connE2EVRange}
+              let rcVs = CR.RatchetVersions {current = e2eVersion, maxSupported = maxVersion e2eEncryptVRange}
              initRatchet rcVs keys
              notifyAgreed
            where
@@ -2571,21 +2599,20 @@ confirmQueueAsync c cData sq srv connInfo e2eEncryption_ subMode = do
  storeConfirmation c cData sq e2eEncryption_ =<< mkAgentConfirmation c cData sq srv connInfo subMode
  lift $ submitPendingMsg c cData sq

-confirmQueue :: Compatible VersionSMPA -> AgentClient -> ConnData -> SndQueue -> SMPServerWithAuth -> ConnInfo -> Maybe (CR.SndE2ERatchetParams 'C.X448) -> SubscriptionMode -> AM ()
-confirmQueue (Compatible agentVersion) c cData@ConnData {connId, pqSupport} sq srv connInfo e2eEncryption_ subMode = do
+confirmQueue :: AgentClient -> ConnData -> SndQueue -> SMPServerWithAuth -> ConnInfo -> Maybe (CR.SndE2ERatchetParams 'C.X448) -> SubscriptionMode -> AM ()
+confirmQueue c cData@ConnData {connId, connAgentVersion, pqSupport} sq srv connInfo e2eEncryption_ subMode = do
  msg <- mkConfirmation =<< mkAgentConfirmation c cData sq srv connInfo subMode
  sendConfirmation c sq msg
  withStore' c $ \db -> setSndQueueStatus db sq Confirmed
  where
    mkConfirmation :: AgentMessage -> AM MsgBody
    mkConfirmation aMessage = do
-      -- the version to be used when PQSupport is disabled
-      currentE2EVersion <- asks $ maxVersion . ($ PQSupportOff) . e2eEncryptVRange . config
+      currentE2EVersion <- asks $ maxVersion . e2eEncryptVRange . config
      withStore c $ \db -> runExceptT $ do
        void . liftIO $ updateSndIds db connId
        let pqEnc = CR.pqSupportToEnc pqSupport
        (encConnInfo, _) <- agentRatchetEncrypt db cData (smpEncode aMessage) e2eEncConnInfoLength (Just pqEnc) currentE2EVersion
-        pure . smpEncode $ AgentConfirmation {agentVersion, e2eEncryption_, encConnInfo}
+        pure . smpEncode $ AgentConfirmation {agentVersion = connAgentVersion, e2eEncryption_, encConnInfo}

 mkAgentConfirmation :: AgentClient -> ConnData -> SndQueue -> SMPServerWithAuth -> ConnInfo -> SubscriptionMode -> AM AgentMessage
 mkAgentConfirmation c cData sq srv connInfo subMode = do
@@ -2599,8 +2626,7 @@ enqueueConfirmation c cData sq connInfo e2eEncryption_ = do

 storeConfirmation :: AgentClient -> ConnData -> SndQueue -> Maybe (CR.SndE2ERatchetParams 'C.X448) -> AgentMessage -> AM ()
 storeConfirmation c cData@ConnData {connId, pqSupport, connAgentVersion = v} sq e2eEncryption_ agentMsg = do
-  -- the version to be used when PQSupport is disabled
-  currentE2EVersion <- asks $ maxVersion . ($ PQSupportOff) . e2eEncryptVRange . config
+  currentE2EVersion <- asks $ maxVersion . e2eEncryptVRange . config
  withStore c $ \db -> runExceptT $ do
    internalTs <- liftIO getCurrentTime
    (internalId, internalSndId, prevMsgHash) <- liftIO $ updateSndIds db connId
@@ -2620,8 +2646,8 @@ enqueueRatchetKeyMsgs c cData (sq :| sqs) e2eEncryption = do
  mapM_ (lift . enqueueSavedMessage c cData msgId) $ filter isActiveSndQ sqs

 enqueueRatchetKey :: AgentClient -> ConnData -> SndQueue -> CR.RcvE2ERatchetParams 'C.X448 -> AM AgentMsgId
-enqueueRatchetKey c cData@ConnData {connId, pqSupport} sq e2eEncryption = do
-  aVRange <- asks $ ($ pqSupport) . smpAgentVRange . config
+enqueueRatchetKey c cData@ConnData {connId} sq e2eEncryption = do
+  aVRange <- asks $ smpAgentVRange . config
  msgId <- storeRatchetKey $ maxVersion aVRange
  lift $ submitPendingMsg c cData sq
  pure $ unId msgId
@@ -630,12 +630,16 @@ reconnectSMPClient tc c tSess@(_, srv, _) qs = do
  let t = (length qs `div` 90 + 1) * tcpTimeout * 3
  ExceptT (sequence <$> (t `timeout` runExceptT resubscribe)) >>= \case
    Just _ -> atomically $ writeTVar tc 0
-    Nothing -> do
-      tc' <- atomically $ stateTVar tc $ \i -> (i + 1, i + 1)
-      maxTC <- asks $ maxSubscriptionTimeouts . config
-      let err = if tc' >= maxTC then CRITICAL True else INTERNAL
-          msg = show tc' <> " consecutive subscription timeouts: " <> show (length qs) <> " queues, transport session: " <> show tSess
-      atomically $ writeTBQueue (subQ c) ("", "", APC SAEConn $ ERR $ err msg)
+    Nothing ->
+      (offline <$> readTVarIO (userNetworkState c)) >>= \case
+        -- reset and do not report consequitive timeouts while offline
+        Just _ -> atomically $ writeTVar tc 0
+        Nothing -> do
+          tc' <- atomically $ stateTVar tc $ \i -> (i + 1, i + 1)
+          maxTC <- asks $ maxSubscriptionTimeouts . config
+          when (tc' >= maxTC) $ do
+            let msg = show tc' <> " consecutive subscription timeouts: " <> show (length qs) <> " queues, transport session: " <> show tSess
+            atomically $ writeTBQueue (subQ c) ("", "", APC SAEConn $ ERR $ INTERNAL msg)
  where
    resubscribe :: AM ()
    resubscribe = do
@@ -688,10 +692,9 @@ getXFTPServerClient c@AgentClient {active, xftpClients, workerSeq} tSess@(userId
    connectClient :: XFTPClientVar -> AM XFTPClient
    connectClient v = do
      cfg <- asks $ xftpCfg . config
-      g <- asks random
      xftpNetworkConfig <- atomically $ getNetworkConfig c
      liftError' (protocolClientError XFTP $ B.unpack $ strEncode srv) $
-        X.getXFTPClient g tSess cfg {xftpNetworkConfig} $
+        X.getXFTPClient tSess cfg {xftpNetworkConfig} $
          clientDisconnected v

    clientDisconnected :: XFTPClientVar -> XFTPClient -> IO ()
@@ -1008,7 +1011,7 @@ runXFTPServerTest c userId (ProtoServerWithAuth srv auth) = do
  rcvPath <- getTempFilePath workDir
  liftIO $ do
    let tSess = (userId, srv, Nothing)
-    X.getXFTPClient g tSess cfg {xftpNetworkConfig} (\_ -> pure ()) >>= \case
+    X.getXFTPClient tSess cfg {xftpNetworkConfig} (\_ -> pure ()) >>= \case
      Right xftp -> withTestChunk filePath $ do
        (sndKey, spKey) <- atomically $ C.generateAuthKeyPair C.SEd25519 g
        (rcvKey, rpKey) <- atomically $ C.generateAuthKeyPair C.SEd25519 g
@@ -56,7 +56,7 @@ import qualified Simplex.Messaging.Agent.Store.SQLite.Migrations as Migrations
 import Simplex.Messaging.Client
 import Simplex.Messaging.Client.Agent ()
 import qualified Simplex.Messaging.Crypto as C
-import Simplex.Messaging.Crypto.Ratchet (PQSupport, VersionRangeE2E, supportedE2EEncryptVRange)
+import Simplex.Messaging.Crypto.Ratchet (VersionRangeE2E, supportedE2EEncryptVRange)
 import Simplex.Messaging.Notifications.Client (defaultNTFClientConfig)
 import Simplex.Messaging.Notifications.Transport (NTFVersion)
 import Simplex.Messaging.Notifications.Types
@@ -117,8 +117,8 @@ data AgentConfig = AgentConfig
    caCertificateFile :: FilePath,
    privateKeyFile :: FilePath,
    certificateFile :: FilePath,
-    e2eEncryptVRange :: PQSupport -> VersionRangeE2E,
-    smpAgentVRange :: PQSupport -> VersionRangeSMPA,
+    e2eEncryptVRange :: VersionRangeE2E,
+    smpAgentVRange :: VersionRangeSMPA,
    smpClientVRange :: VersionRangeSMPC
  }

@@ -181,7 +181,7 @@ defaultAgentConfig =
      maxWorkerRestartsPerMin = 5,
      -- 3 consecutive subscription timeouts will result in alert to the user
      -- this is a fallback, as the timeout set to 3x of expected timeout, to avoid potential locking.
-      maxSubscriptionTimeouts = 3,
+      maxSubscriptionTimeouts = 5,
      storedMsgDataTTL = 21 * nominalDay,
      rcvFilesTTL = 2 * nominalDay,
      sndFilesTTL = nominalDay,
@@ -44,7 +44,7 @@ module Simplex.Messaging.Agent.Protocol
    currentSMPAgentVersion,
    supportedSMPAgentVRange,
    e2eEncConnInfoLength,
-    e2eEncUserMsgLength,
+    e2eEncAgentMsgLength,

    -- * SMP agent protocol types
    ConnInfo,
@@ -272,16 +272,11 @@ deliveryRcptsSMPAgentVersion = VersionSMPA 4
 pqdrSMPAgentVersion :: VersionSMPA
 pqdrSMPAgentVersion = VersionSMPA 5

-- TODO v5.7 increase to 5
 currentSMPAgentVersion :: VersionSMPA
-currentSMPAgentVersion = VersionSMPA 4
+currentSMPAgentVersion = VersionSMPA 5

-- TODO v5.7 remove dependency of version range on whether PQ support is needed
-supportedSMPAgentVRange :: PQSupport -> VersionRangeSMPA
-supportedSMPAgentVRange pq =
-  mkVersionRange duplexHandshakeSMPAgentVersion $ case pq of
-    PQSupportOn -> pqdrSMPAgentVersion
-    PQSupportOff -> currentSMPAgentVersion
+supportedSMPAgentVRange :: VersionRangeSMPA
+supportedSMPAgentVRange = mkVersionRange duplexHandshakeSMPAgentVersion currentSMPAgentVersion

 -- it is shorter to allow all handshake headers,
 -- including E2E (double-ratchet) parameters and
@@ -292,8 +287,8 @@ e2eEncConnInfoLength v = \case
  PQSupportOn | v >= pqdrSMPAgentVersion -> 11122
  _ -> 14848

-e2eEncUserMsgLength :: VersionSMPA -> PQSupport -> Int
-e2eEncUserMsgLength v = \case
+e2eEncAgentMsgLength :: VersionSMPA -> PQSupport -> Int
+e2eEncAgentMsgLength v = \case
  -- reduced by 2222 (the increase of message ratchet header size)
  PQSupportOn | v >= pqdrSMPAgentVersion -> 13634
  _ -> 15856
@@ -49,7 +49,7 @@ runSMPAgentBlocking (ATransport t) cfg@AgentConfig {tcpPort, caCertificateFile,
    smpAgent :: forall c. Transport c => TProxy c -> ServiceName -> Env -> IO ()
    smpAgent _ port env = do
      -- tlsServerParams is not in Env to avoid breaking functional API w/t key and certificate generation
-      tlsServerParams <- loadTLSServerParams caCertificateFile certificateFile privateKeyFile
+      tlsServerParams <- loadTLSServerParams caCertificateFile certificateFile privateKeyFile Nothing
      clientId <- newTVarIO initClientId
      runTransportServer started port tlsServerParams defaultTransportServerConfig $ \(h :: c) -> do
        putLn h $ "Welcome to SMP agent v" <> B.pack simplexMQVersion
@@ -54,9 +54,6 @@ module Simplex.Messaging.Client
    suspendSMPQueue,
    deleteSMPQueue,
    deleteSMPQueues,
-    createSMPProxySession,
-    proxySMPMessage,
-    forwardSMPMessage,
    sendProtocolCommand,

    -- * Supporting types and client configuration
@@ -72,7 +69,6 @@ module Simplex.Messaging.Client
    chooseTransportHost,
    proxyUsername,
    temporaryClientError,
-    smpProxyError,
    ServerTransmission,
    ClientCommand,

@@ -101,23 +97,20 @@ import Data.List (find)
 import Data.List.NonEmpty (NonEmpty (..))
 import qualified Data.List.NonEmpty as L
 import Data.Maybe (fromMaybe)
-import Data.Time.Clock (UTCTime (..), getCurrentTime)
-import qualified Data.X509 as X
-import qualified Data.X509.Validation as XV
+import Data.Time.Clock (UTCTime (..), diffUTCTime, getCurrentTime)
 import Network.Socket (ServiceName)
 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)
 import Simplex.Messaging.Protocol
 import Simplex.Messaging.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
 import Simplex.Messaging.Transport
-import Simplex.Messaging.Transport.Client (SocksProxy, TransportClientConfig (..), TransportHost (..), runTransportClient)
+import Simplex.Messaging.Transport.Client (SocksProxy, TransportClientConfig (..), TransportHost (..), defaultTcpConnectTimeout, runTransportClient)
 import Simplex.Messaging.Transport.KeepAlive
 import Simplex.Messaging.Transport.WebSockets (WS)
-import Simplex.Messaging.Util (bshow, liftEitherWith, raceAny_, threadDelay')
+import Simplex.Messaging.Util (bshow, diffToMicroseconds, raceAny_, threadDelay', whenM)
 import Simplex.Messaging.Version
 import System.Timeout (timeout)

@@ -136,21 +129,26 @@ data PClient v err msg = PClient
    transportSession :: TransportSession msg,
    transportHost :: TransportHost,
    tcpTimeout :: Int,
-    batchDelay :: Maybe Int,
-    pingErrorCount :: TVar Int,
+    rcvConcurrency :: Int,
+    sendPings :: TVar Bool,
+    lastReceived :: TVar UTCTime,
+    timeoutErrorCount :: TVar Int,
    clientCorrId :: TVar ChaChaDRG,
    sentCommands :: TMap CorrId (Request err msg),
-    sndQ :: TBQueue ByteString,
+    sndQ :: TBQueue (TVar Bool, ByteString),
    rcvQ :: TBQueue (NonEmpty (SignedTransmission err msg)),
    msgQ :: Maybe (TBQueue (ServerTransmission v msg))
  }

 smpClientStub :: TVar ChaChaDRG -> ByteString -> VersionSMP -> Maybe (THandleAuth 'TClient) -> STM SMPClient
 smpClientStub g sessionId thVersion thAuth = do
+  let ts = UTCTime (read "2024-03-31") 0
  connected <- newTVar False
  clientCorrId <- C.newRandomDRG g
  sentCommands <- TM.empty
-  pingErrorCount <- newTVar 0
+  sendPings <- newTVar False
+  lastReceived <- newTVar ts
+  timeoutErrorCount <- newTVar 0
  sndQ <- newTBQueue 100
  rcvQ <- newTBQueue 100
  return
@@ -165,15 +163,17 @@ smpClientStub g sessionId thVersion thAuth = do
              implySessId = thVersion >= authCmdsSMPVersion,
              batch = True
            },
-        sessionTs = UTCTime (read "2024-03-31") 0,
+        sessionTs = ts,
        client_ =
          PClient
            { connected,
              transportSession = (1, "smp://LcJUMfVhwD8yxjAiSaDzzGF3-kLG4Uh0Fl_ZIjrRwjI=@localhost:5001", Nothing),
              transportHost = "localhost",
              tcpTimeout = 15_000_000,
-              batchDelay = Nothing,
-              pingErrorCount,
+              rcvConcurrency = 8,
+              sendPings,
+              lastReceived,
+              timeoutErrorCount,
              clientCorrId,
              sentCommands,
              sndQ,
@@ -188,7 +188,7 @@ type SMPClient = ProtocolClient SMPVersion ErrorType BrokerMsg
 type ClientCommand msg = (Maybe C.APrivateAuthKey, EntityId, ProtoCommand msg)

 -- | Type synonym for transmission from some SPM server queue.
-type ServerTransmission v msg = (TransportSession msg, Version v, SessionId, EntityId, msg)
+type ServerTransmission v msg = (TransportSession msg, Version v, SessionId, Bool, EntityId, msg)

 data HostMode
  = -- | prefer (or require) onion hosts when connecting via SOCKS proxy
@@ -215,11 +215,13 @@ data NetworkConfig = NetworkConfig
    tcpTimeout :: Int,
    -- | additional timeout per kilobyte (1024 bytes) to be sent
    tcpTimeoutPerKb :: Int64,
+    -- | break response timeouts into groups, so later responses get later deadlines
+    rcvConcurrency :: Int,
    -- | TCP keep-alive options, Nothing to skip enabling keep-alive
    tcpKeepAlive :: Maybe KeepAliveOpts,
    -- | period for SMP ping commands (microseconds, 0 to disable)
    smpPingInterval :: Int64,
-    -- | the count of PING errors after which SMP client terminates (and will be reconnected), 0 to disable
+    -- | the count of timeout errors after which SMP client terminates (and will be reconnected), 0 to disable
    smpPingCount :: Int,
    logTLSErrors :: Bool
  }
@@ -235,9 +237,10 @@ defaultNetworkConfig =
      hostMode = HMOnionViaSocks,
      requiredHostMode = False,
      sessionMode = TSMUser,
-      tcpConnectTimeout = 20_000_000,
+      tcpConnectTimeout = defaultTcpConnectTimeout,
      tcpTimeout = 15_000_000,
      tcpTimeoutPerKb = 5_000,
+      rcvConcurrency = 8,
      tcpKeepAlive = Just defaultKeepAliveOpts,
      smpPingInterval = 600_000_000, -- 10min
      smpPingCount = 3,
@@ -245,8 +248,8 @@ defaultNetworkConfig =
    }

 transportClientConfig :: NetworkConfig -> TransportClientConfig
-transportClientConfig NetworkConfig {socksProxy, tcpKeepAlive, logTLSErrors} =
-  TransportClientConfig {socksProxy, tcpKeepAlive, logTLSErrors, clientCredentials = Nothing, alpn = Nothing}
+transportClientConfig NetworkConfig {socksProxy, tcpConnectTimeout, tcpKeepAlive, logTLSErrors} =
+  TransportClientConfig {socksProxy, tcpConnectTimeout, tcpKeepAlive, logTLSErrors, clientCredentials = Nothing, alpn = Nothing}
 {-# INLINE transportClientConfig #-}

 -- | protocol client configuration.
@@ -257,30 +260,33 @@ data ProtocolClientConfig v = ProtocolClientConfig
    defaultTransport :: (ServiceName, ATransport),
    -- | network configuration
    networkConfig :: NetworkConfig,
+    clientALPN :: Maybe [ALPN],
    -- | client-server protocol version range
    serverVRange :: VersionRange v,
-    -- | delay between sending batches of commands (microseconds)
-    batchDelay :: Maybe Int
+    -- | agree shared session secret (used in SMP proxy)
+    agreeSecret :: Bool
  }

 -- | Default protocol client configuration.
-defaultClientConfig :: VersionRange v -> ProtocolClientConfig v
-defaultClientConfig serverVRange =
+defaultClientConfig :: Maybe [ALPN] -> VersionRange v -> ProtocolClientConfig v
+defaultClientConfig clientALPN serverVRange =
  ProtocolClientConfig
    { qSize = 64,
      defaultTransport = ("443", transport @TLS),
      networkConfig = defaultNetworkConfig,
+      clientALPN,
      serverVRange,
-      batchDelay = Nothing
+      agreeSecret = False
    }
 {-# INLINE defaultClientConfig #-}

 defaultSMPClientConfig :: ProtocolClientConfig SMPVersion
-defaultSMPClientConfig = defaultClientConfig supportedClientSMPRelayVRange
+defaultSMPClientConfig = defaultClientConfig (Just supportedSMPHandshakes) supportedClientSMPRelayVRange
 {-# INLINE defaultSMPClientConfig #-}

 data Request err msg = Request
-  { entityId :: EntityId,
+  { corrId :: CorrId,
+    entityId :: EntityId,
    responseVar :: TMVar (Either (ProtocolClientError err) msg)
  }

@@ -328,18 +334,20 @@ type TransportSession msg = (UserId, ProtoServer msg, Maybe EntityId)
 -- 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 -> TransportSession msg -> ProtocolClientConfig v -> Maybe (TBQueue (ServerTransmission v msg)) -> (ProtocolClient v err msg -> IO ()) -> IO (Either (ProtocolClientError err) (ProtocolClient v err msg))
-getProtocolClient g transportSession@(_, srv, _) cfg@ProtocolClientConfig {qSize, networkConfig, serverVRange, batchDelay} msgQ disconnected = do
+getProtocolClient g transportSession@(_, srv, _) cfg@ProtocolClientConfig {qSize, networkConfig, clientALPN, serverVRange, agreeSecret} msgQ disconnected = do
  case chooseTransportHost networkConfig (host srv) of
    Right useHost ->
-      (atomically (mkProtocolClient useHost) >>= runClient useTransport useHost)
+      (getCurrentTime >>= atomically . mkProtocolClient useHost >>= runClient useTransport useHost)
        `catch` \(e :: IOException) -> pure . Left $ PCEIOError e
    Left e -> pure $ Left e
  where
-    NetworkConfig {tcpConnectTimeout, tcpTimeout, smpPingInterval} = networkConfig
-    mkProtocolClient :: TransportHost -> STM (PClient v err msg)
-    mkProtocolClient transportHost = do
+    NetworkConfig {tcpConnectTimeout, tcpTimeout, rcvConcurrency, smpPingInterval} = networkConfig
+    mkProtocolClient :: TransportHost -> UTCTime -> STM (PClient v err msg)
+    mkProtocolClient transportHost ts = do
      connected <- newTVar False
-      pingErrorCount <- newTVar 0
+      sendPings <- newTVar False
+      lastReceived <- newTVar ts
+      timeoutErrorCount <- newTVar 0
      clientCorrId <- C.newRandomDRG g
      sentCommands <- TM.empty
      sndQ <- newTBQueue qSize
@@ -350,10 +358,12 @@ getProtocolClient g transportSession@(_, srv, _) cfg@ProtocolClientConfig {qSize
            transportSession,
            transportHost,
            tcpTimeout,
-            batchDelay,
-            pingErrorCount,
+            sendPings,
+            lastReceived,
+            timeoutErrorCount,
            clientCorrId,
            sentCommands,
+            rcvConcurrency,
            sndQ,
            rcvQ,
            msgQ
@@ -362,7 +372,7 @@ getProtocolClient g transportSession@(_, srv, _) cfg@ProtocolClientConfig {qSize
    runClient :: (ServiceName, ATransport) -> TransportHost -> PClient v err msg -> IO (Either (ProtocolClientError err) (ProtocolClient v err msg))
    runClient (port', ATransport t) useHost c = do
      cVar <- newEmptyTMVarIO
-      let tcConfig = transportClientConfig networkConfig
+      let tcConfig = (transportClientConfig networkConfig) {alpn = clientALPN}
          username = proxyUsername transportSession
      action <-
        async $
@@ -382,12 +392,13 @@ getProtocolClient g transportSession@(_, srv, _) cfg@ProtocolClientConfig {qSize

    client :: forall c. Transport c => TProxy c -> PClient v err msg -> TMVar (Either (ProtocolClientError err) (ProtocolClient v err msg)) -> c -> IO ()
    client _ c cVar h = do
-      ks <- atomically $ C.generateKeyPair g
+      ks <- if agreeSecret then Just <$> atomically (C.generateKeyPair g) else pure Nothing
      runExceptT (protocolClientHandshake @v @err @msg h ks (keyHash srv) serverVRange) >>= \case
        Left e -> atomically . putTMVar cVar . Left $ PCETransportError e
        Right th@THandle {params} -> do
          sessionTs <- getCurrentTime
          let c' = ProtocolClient {action = Nothing, client_ = c, thParams = params, sessionTs}
+          atomically $ writeTVar (lastReceived c) sessionTs
          atomically $ do
            writeTVar (connected c) True
            putTMVar cVar $ Right c'
@@ -395,36 +406,48 @@ getProtocolClient g transportSession@(_, srv, _) cfg@ProtocolClientConfig {qSize
            `finally` disconnected c'

    send :: Transport c => ProtocolClient v err msg -> THandle v c 'TClient -> IO ()
-    send ProtocolClient {client_ = PClient {sndQ}} h = forever $ atomically (readTBQueue sndQ) >>= tPutLog h
+    send ProtocolClient {client_ = PClient {sndQ}} h = forever $ atomically (readTBQueue sndQ) >>= \(active, s) -> whenM (readTVarIO active) (void $ tPutLog h s)

    receive :: Transport c => ProtocolClient v err msg -> THandle v c 'TClient -> IO ()
-    receive ProtocolClient {client_ = PClient {rcvQ}} h = forever $ tGet h >>= atomically . writeTBQueue rcvQ
+    receive ProtocolClient {client_ = PClient {rcvQ, lastReceived, timeoutErrorCount}} h = forever $ do
+      tGet h >>= atomically . writeTBQueue rcvQ
+      getCurrentTime >>= atomically . writeTVar lastReceived
+      atomically $ writeTVar timeoutErrorCount 0

    ping :: ProtocolClient v err msg -> IO ()
-    ping c@ProtocolClient {client_ = PClient {pingErrorCount}} = do
-      threadDelay' smpPingInterval
-      runExceptT (sendProtocolCommand c Nothing "" $ protocolPing @v @err @msg) >>= \case
-        Left PCEResponseTimeout -> do
-          cnt <- atomically $ stateTVar pingErrorCount $ \cnt -> (cnt + 1, cnt + 1)
-          when (maxCnt == 0 || cnt < maxCnt) $ ping c
-        _ -> ping c -- sendProtocolCommand resets pingErrorCount
+    ping c@ProtocolClient {client_ = PClient {sendPings, lastReceived, timeoutErrorCount}} = loop smpPingInterval
      where
+        loop :: Int64 -> IO ()
+        loop delay = do
+          threadDelay' delay
+          diff <- diffUTCTime <$> getCurrentTime <*> readTVarIO lastReceived
+          let idle = diffToMicroseconds diff
+              remaining = smpPingInterval - idle
+          if remaining > 1_000_000 -- delay pings only for significant time
+            then loop remaining
+            else do
+              whenM (readTVarIO sendPings) $ void . runExceptT $ sendProtocolCommand c Nothing "" (protocolPing @v @err @msg)
+              -- sendProtocolCommand/getResponse updates counter for each command
+              cnt <- readTVarIO timeoutErrorCount
+              -- drop client when maxCnt of commands have timed out in sequence, but only after some time has passed after last received response
+              when (maxCnt == 0 || cnt < maxCnt || diff < recoverWindow) $ loop smpPingInterval
+        recoverWindow = 15 * 60 -- seconds
        maxCnt = smpPingCount networkConfig

    process :: ProtocolClient v err msg -> IO ()
    process c = forever $ atomically (readTBQueue $ rcvQ $ client_ c) >>= mapM_ (processMsg c)

    processMsg :: ProtocolClient v err msg -> SignedTransmission err msg -> IO ()
-    processMsg c@ProtocolClient {client_ = PClient {sentCommands}} (_, _, (corrId, entId, respOrErr)) =
-      if B.null $ bs corrId
-        then sendMsg respOrErr
-        else do
+    processMsg c@ProtocolClient {client_ = PClient {sentCommands}} (_, _, (corrId, entId, respOrErr))
+      | isResponse =
          atomically (TM.lookup corrId sentCommands) >>= \case
            Nothing -> sendMsg respOrErr
            Just Request {entityId, responseVar} -> atomically $ do
              TM.delete corrId sentCommands
              putTMVar responseVar $ response entityId
+      | otherwise = sendMsg respOrErr
      where
+        isResponse = not $ B.null $ bs corrId
        response entityId
          | entityId == entId =
              case respOrErr of
@@ -435,7 +458,7 @@ getProtocolClient g transportSession@(_, srv, _) cfg@ProtocolClientConfig {qSize
          | otherwise = Left . PCEUnexpectedResponse $ bshow respOrErr
        sendMsg :: Either err msg -> IO ()
        sendMsg = \case
-          Right msg -> atomically $ mapM_ (`writeTBQueue` serverTransmission c entId msg) msgQ
+          Right msg -> atomically $ mapM_ (`writeTBQueue` serverTransmission c isResponse entId msg) msgQ
          Left e -> putStrLn $ "SMP client error: " <> show e

 proxyUsername :: TransportSession msg -> ByteString
@@ -487,19 +510,6 @@ temporaryClientError = \case
  _ -> False
 {-# INLINE temporaryClientError #-}

-- TODO keep error params
-smpProxyError :: SMPClientError -> ErrorType
-smpProxyError = \case
-  PCEProtocolError _ -> PROXY PROTOCOL
-  PCEResponseError _ -> PROXY RESPONSE
-  PCEUnexpectedResponse _ -> PROXY UNEXPECTED
-  PCEResponseTimeout -> PROXY TIMEOUT
-  PCENetworkError -> PROXY NETWORK
-  PCEIncompatibleHost -> PROXY BAD_HOST
-  PCETransportError _ -> PROXY TRANSPORT
-  PCECryptoError _ -> INTERNAL
-  PCEIOError _ -> INTERNAL
-
 -- | Create a new SMP queue.
 --
 -- https://github.com/simplex-chat/simplexmq/blob/master/protocol/simplex-messaging.md#create-queue-command
@@ -519,15 +529,18 @@ createSMPQueue c (rKey, rpKey) dhKey auth subMode =
 --
 -- https://github.com/simplex-chat/simplexmq/blob/master/protocol/simplex-messaging.md#subscribe-to-queue
 subscribeSMPQueue :: SMPClient -> RcvPrivateAuthKey -> RecipientId -> ExceptT SMPClientError IO ()
-subscribeSMPQueue c rpKey rId =
+subscribeSMPQueue c@ProtocolClient {client_ = PClient {sendPings}} rpKey rId = do
+  liftIO . atomically $ writeTVar sendPings True
  sendSMPCommand c (Just rpKey) rId SUB >>= \case
-    OK -> return ()
+    OK -> pure ()
    cmd@MSG {} -> liftIO $ writeSMPMessage c rId cmd
    r -> throwE . PCEUnexpectedResponse $ bshow r

 -- | Subscribe to multiple SMP queues batching commands if supported.
 subscribeSMPQueues :: SMPClient -> NonEmpty (RcvPrivateAuthKey, RecipientId) -> IO (NonEmpty (Either SMPClientError ()))
-subscribeSMPQueues c qs = sendProtocolCommands c cs >>= mapM (processSUBResponse c)
+subscribeSMPQueues c@ProtocolClient {client_ = PClient {sendPings}} qs = do
+  atomically $ writeTVar sendPings True
+  sendProtocolCommands c cs >>= mapM (processSUBResponse c)
  where
    cs = L.map (\(rpKey, rId) -> (Just rpKey, rId, Cmd SRecipient SUB)) qs

@@ -545,11 +558,11 @@ processSUBResponse c (Response rId r) = case r of
  Left e -> pure $ Left e

 writeSMPMessage :: SMPClient -> RecipientId -> BrokerMsg -> IO ()
-writeSMPMessage c rId msg = atomically $ mapM_ (`writeTBQueue` serverTransmission c rId msg) (msgQ $ client_ c)
+writeSMPMessage c rId msg = atomically $ mapM_ (`writeTBQueue` serverTransmission c False rId msg) (msgQ $ client_ c)

-serverTransmission :: ProtocolClient v err msg -> RecipientId -> msg -> ServerTransmission v msg
-serverTransmission ProtocolClient {thParams = THandleParams {thVersion, sessionId}, client_ = PClient {transportSession}} entityId message =
-  (transportSession, thVersion, sessionId, entityId, message)
+serverTransmission :: ProtocolClient v err msg -> Bool -> RecipientId -> msg -> ServerTransmission v msg
+serverTransmission ProtocolClient {thParams = THandleParams {thVersion, sessionId}, client_ = PClient {transportSession}} isResponse entityId message =
+  (transportSession, thVersion, sessionId, isResponse, entityId, message)

 -- | Get message from SMP queue. The server returns ERR PROHIBITED if a client uses SUB and GET via the same transport connection for the same queue
 --
@@ -650,102 +663,6 @@ deleteSMPQueues :: SMPClient -> NonEmpty (RcvPrivateAuthKey, RecipientId) -> IO
 deleteSMPQueues = okSMPCommands DEL
 {-# INLINE deleteSMPQueues #-}

-- TODO picture
-
-- send PRXY :: SMPServer -> Maybe BasicAuth -> Command Sender
-- receives PKEY :: SessionId -> X.CertificateChain -> X.SignedExact X.PubKey -> BrokerMsg
-createSMPProxySession :: SMPClient -> SMPServer -> Maybe BasicAuth -> ExceptT SMPClientError IO (SessionId, VersionSMP, C.PublicKeyX25519)
-createSMPProxySession c relayServ@ProtocolServer {keyHash = C.KeyHash kh} proxyAuth =
-  sendSMPCommand c Nothing "" (PRXY relayServ proxyAuth) >>= \case
-    -- XXX: rfc says sessionId should be in the entityId of response
-    PKEY sId vr (chain, key) -> do
-      case supportedClientSMPRelayVRange `compatibleVersion` vr of
-        Nothing -> throwE PCEIncompatibleHost -- TODO different error
-        Just (Compatible v) -> liftEitherWith x509Error $ (sId,v,) <$> validateRelay chain key
-    r -> throwE . PCEUnexpectedResponse $ bshow r
-  where
-    x509Error :: String -> SMPClientError
-    x509Error _msg = PCEResponseError $ error "TODO: x509 error" -- TODO different error
-    validateRelay :: X.CertificateChain -> X.SignedExact X.PubKey -> Either String C.PublicKeyX25519
-    validateRelay (X.CertificateChain cert) exact = do
-      serverKey <- case cert of
-        [leaf, ca]
-          | XV.Fingerprint kh == XV.getFingerprint ca X.HashSHA256 ->
-              C.x509ToPublic (X.certPubKey . X.signedObject $ X.getSigned leaf, []) >>= C.pubKey
-        _ -> throwError "bad certificate"
-      pubKey <- C.verifyX509 serverKey exact
-      C.x509ToPublic (pubKey, []) >>= C.pubKey
-
-- 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
-proxySMPMessage ::
-  SMPClient ->
-  -- proxy session from PKEY
-  SessionId ->
-  VersionSMP ->
-  C.PublicKeyX25519 ->
-  -- message to deliver
-  Maybe SndPrivateAuthKey ->
-  SenderId ->
-  MsgFlags ->
-  MsgBody ->
-  ExceptT SMPClientError IO ()
-- TODO use version
-proxySMPMessage c@ProtocolClient {thParams = proxyThParams, client_ = PClient {clientCorrId = g}} sessionId _v serverKey spKey sId flags msg = do
-  -- prepare params
-  let serverThAuth = (\ta -> ta {serverPeerPubKey = serverKey}) <$> thAuth proxyThParams
-      serverThParams = proxyThParams {sessionId, thAuth = serverThAuth}
-  (cmdPubKey, cmdPrivKey) <- liftIO . atomically $ C.generateKeyPair @'C.X25519 g
-  let cmdSecret = C.dh' serverKey cmdPrivKey
-  nonce@(C.CbNonce corrId) <- liftIO . atomically $ C.randomCbNonce g
-  -- encode
-  let TransmissionForAuth {tForAuth, tToSend} = encodeTransmissionForAuth serverThParams (CorrId corrId, sId, Cmd SSender $ SEND flags msg)
-  auth <- liftEitherWith PCETransportError $ authTransmission serverThAuth spKey nonce tForAuth
-  b <- case batchTransmissions (batch serverThParams) (blockSize serverThParams) [Right (auth, tToSend)] of
-    [] -> throwE $ PCETransportError TELargeMsg -- some other error. Internal?
-    TBError e _ : _ -> throwE $ PCETransportError e -- large message error?
-    TBTransmission s _ : _ -> pure s
-    TBTransmissions s _ _ : _ -> pure s
-  et <- liftEitherWith PCECryptoError $ EncTransmission <$> C.cbEncrypt cmdSecret nonce b paddedProxiedMsgLength
-  sendProtocolCommand_ c (Just nonce) Nothing sessionId (Cmd SProxiedClient (PFWD cmdPubKey et)) >>= \case
-    -- TODO support PKEY + resend?
-    PRES (EncResponse er) -> do
-      t' <- liftEitherWith PCECryptoError $ C.cbDecrypt cmdSecret (C.reverseNonce nonce) er
-      case tParse proxyThParams t' of
-        t'' :| [] -> case tDecodeParseValidate proxyThParams t'' of
-          (_auth, _signed, (_c, _e, r)) -> case r of -- TODO: verify
-            Left e -> throwE $ PCEResponseError e
-            Right OK -> pure ()
-            Right (ERR e) -> throwE $ PCEProtocolError e
-            Right u -> throwE . PCEUnexpectedResponse $ bshow u -- possibly differentiate unexpected response from server/proxy
-        _ -> throwE $ PCETransportError TEBadBlock
-    r -> throwE . PCEUnexpectedResponse $ bshow r -- from proxy
-
-- this method is used in the proxy
-- sends RFWD :: EncFwdTransmission -> Command Sender
-- receives RRES :: EncFwdResponse -> BrokerMsg
-- proxy should send PRES to the client with EncResponse
-forwardSMPMessage :: SMPClient -> CorrId -> C.PublicKeyX25519 -> EncTransmission -> ExceptT SMPClientError IO EncResponse
-forwardSMPMessage c@ProtocolClient {thParams, client_ = PClient {clientCorrId = g}} fwdCorrId fwdKey fwdTransmission = do
-  -- prepare params
-  sessSecret <- case thAuth thParams of
-    Nothing -> throwError $ PCEProtocolError INTERNAL -- different error - proxy didn't pass key?
-    Just THAuthClient {serverPeerPubKey, clientPrivKey} -> pure $ C.dh' serverPeerPubKey clientPrivKey
-  nonce <- liftIO . atomically $ C.randomCbNonce g
-  -- wrap
-  let fwdT = FwdTransmission {fwdCorrId, fwdKey, fwdTransmission}
-  eft <- liftEitherWith PCECryptoError $ EncFwdTransmission <$> C.cbEncrypt sessSecret nonce (smpEncode fwdT) paddedForwardedMsgLength
-  -- send
-  sendProtocolCommand_ c (Just nonce) Nothing "" (Cmd SSender (RFWD eft)) >>= \case
-    RRES (EncFwdResponse efr) -> do
-      -- unwrap
-      r' <- liftEitherWith PCECryptoError $ C.cbDecrypt sessSecret (C.reverseNonce nonce) efr
-      FwdResponse {fwdCorrId = _, fwdResponse} <- liftEitherWith (const $ PCEResponseError BLOCK) $ smpDecode r'
-      pure fwdResponse
-    r -> throwE . PCEUnexpectedResponse $ bshow r
-
 okSMPCommand :: PartyI p => Command p -> SMPClient -> C.APrivateAuthKey -> QueueId -> ExceptT SMPClientError IO ()
 okSMPCommand cmd c pKey qId =
  sendSMPCommand c (Just pKey) qId cmd >>= \case
@@ -793,27 +710,26 @@ streamProtocolCommands c@ProtocolClient {thParams = THandleParams {batch, blockS
  mapM_ (cb <=< sendBatch c) bs

 sendBatch :: ProtocolClient v err msg -> TransportBatch (Request err msg) -> IO [Response err msg]
-sendBatch c@ProtocolClient {client_ = PClient {sndQ}} b = do
+sendBatch c@ProtocolClient {client_ = PClient {rcvConcurrency, sndQ}} b = do
  case b of
    TBError e Request {entityId} -> do
      putStrLn "send error: large message"
      pure [Response entityId $ Left $ PCETransportError e]
    TBTransmissions s n rs
      | n > 0 -> do
-          atomically $ writeTBQueue sndQ s
-          mapConcurrently (getResponse c) rs
+          active <- newTVarIO True
+          atomically $ writeTBQueue sndQ (active, s)
+          mapConcurrently (getResponse c active) rs
      | otherwise -> pure []
    TBTransmission s r -> do
-      atomically $ writeTBQueue sndQ s
-      (: []) <$> getResponse c r
+      active <- newTVarIO True
+      atomically $ writeTBQueue sndQ (active, s)
+      (: []) <$> getResponse c active r

 -- | Send Protocol command
 sendProtocolCommand :: forall v err msg. ProtocolEncoding v err (ProtoCommand msg) => ProtocolClient v err msg -> Maybe C.APrivateAuthKey -> EntityId -> ProtoCommand msg -> ExceptT (ProtocolClientError err) IO msg
-sendProtocolCommand c = sendProtocolCommand_ c Nothing
-
-sendProtocolCommand_ :: forall v err msg. ProtocolEncoding v err (ProtoCommand msg) => ProtocolClient v err msg -> Maybe C.CbNonce -> Maybe C.APrivateAuthKey -> EntityId -> ProtoCommand msg -> ExceptT (ProtocolClientError err) IO msg
-sendProtocolCommand_ c@ProtocolClient {client_ = PClient {sndQ}, thParams = THandleParams {batch, blockSize}} nonce_ pKey entId cmd =
-  ExceptT $ uncurry sendRecv =<< mkTransmission_ c nonce_ (pKey, entId, cmd)
+sendProtocolCommand c@ProtocolClient {client_ = PClient {sndQ}, thParams = THandleParams {batch, blockSize}} pKey entId cmd =
+  ExceptT $ uncurry sendRecv =<< mkTransmission c (pKey, entId, cmd)
  where
    -- two separate "atomically" needed to avoid blocking
    sendRecv :: Either TransportError SentRawTransmission -> Request err msg -> IO (Either (ProtocolClientError err) msg)
@@ -821,46 +737,50 @@ sendProtocolCommand_ c@ProtocolClient {client_ = PClient {sndQ}, thParams = THan
      Left e -> pure . Left $ PCETransportError e
      Right t
        | B.length s > blockSize - 2 -> pure . Left $ PCETransportError TELargeMsg
-        | otherwise -> atomically (writeTBQueue sndQ s) >> response <$> getResponse c r
+        | otherwise -> do
+            active <- newTVarIO True
+            atomically (writeTBQueue sndQ (active, s))
+            response <$> getResponse c active r
        where
          s
            | batch = tEncodeBatch1 t
            | otherwise = tEncode t

 -- TODO switch to timeout or TimeManager that supports Int64
-getResponse :: ProtocolClient v err msg -> Request err msg -> IO (Response err msg)
-getResponse ProtocolClient {client_ = PClient {tcpTimeout, pingErrorCount}} Request {entityId, responseVar} = do
+getResponse :: ProtocolClient v err msg -> TVar Bool -> Request err msg -> IO (Response err msg)
+getResponse ProtocolClient {client_ = PClient {tcpTimeout, timeoutErrorCount, sentCommands}} active Request {corrId, entityId, responseVar} = do
  response <-
    timeout tcpTimeout (atomically (takeTMVar responseVar)) >>= \case
-      -- BTW: another registerDelay candidate. Also, crashes caller with BlockedIndef.
-      Just r -> atomically (writeTVar pingErrorCount 0) $> r
-      Nothing -> pure $ Left PCEResponseTimeout
+      Just r -> atomically (writeTVar timeoutErrorCount 0) $> r
+      Nothing -> do
+        atomically (writeTVar active False >> TM.delete corrId sentCommands)
+        atomically $ modifyTVar' timeoutErrorCount (+ 1)
+        pure $ Left PCEResponseTimeout
  pure Response {entityId, response}

-mkTransmission :: ProtocolEncoding v err (ProtoCommand msg) => ProtocolClient v err msg -> ClientCommand msg -> IO (PCTransmission err msg)
-mkTransmission c = mkTransmission_ c Nothing
-
-mkTransmission_ :: forall v err msg. ProtocolEncoding v err (ProtoCommand msg) => ProtocolClient v err msg -> Maybe C.CbNonce -> ClientCommand msg -> IO (PCTransmission err msg)
-mkTransmission_ ProtocolClient {thParams, client_ = PClient {clientCorrId, sentCommands}} nonce_ (pKey_, entId, cmd) = do
-  nonce@(C.CbNonce corrId) <- maybe (atomically $ C.randomCbNonce clientCorrId) pure nonce_
-  let TransmissionForAuth {tForAuth, tToSend} = encodeTransmissionForAuth thParams (CorrId corrId, entId, cmd)
-      auth = authTransmission (thAuth thParams) pKey_ nonce tForAuth
-  r <- atomically $ mkRequest (CorrId corrId)
+mkTransmission :: forall v err msg. ProtocolEncoding v err (ProtoCommand msg) => ProtocolClient v err msg -> ClientCommand msg -> IO (PCTransmission err msg)
+mkTransmission ProtocolClient {thParams, client_ = PClient {clientCorrId, sentCommands}} (pKey_, entId, cmd) = do
+  corrId <- atomically getNextCorrId
+  let TransmissionForAuth {tForAuth, tToSend} = encodeTransmissionForAuth thParams (corrId, entId, cmd)
+      auth = authTransmission (thAuth thParams) pKey_ corrId tForAuth
+  r <- atomically $ mkRequest corrId
  pure ((,tToSend) <$> auth, r)
  where
+    getNextCorrId :: STM CorrId
+    getNextCorrId = CorrId <$> C.randomBytes 24 clientCorrId -- also used as nonce
    mkRequest :: CorrId -> STM (Request err msg)
    mkRequest corrId = do
-      r <- Request entId <$> newEmptyTMVar
+      r <- Request corrId entId <$> newEmptyTMVar
      TM.insert corrId r sentCommands
      pure r

-authTransmission :: Maybe (THandleAuth 'TClient) -> Maybe C.APrivateAuthKey -> C.CbNonce -> ByteString -> Either TransportError (Maybe TransmissionAuth)
-authTransmission thAuth pKey_ nonce t = traverse authenticate pKey_
+authTransmission :: Maybe (THandleAuth 'TClient) -> Maybe C.APrivateAuthKey -> CorrId -> ByteString -> Either TransportError (Maybe TransmissionAuth)
+authTransmission thAuth pKey_ (CorrId corrId) t = traverse authenticate pKey_
  where
    authenticate :: C.APrivateAuthKey -> Either TransportError TransmissionAuth
    authenticate (C.APrivateAuthKey a pk) = case a of
      C.SX25519 -> case thAuth of
-        Just THAuthClient {serverPeerPubKey = k} -> Right $ TAAuthenticator $ C.cbAuthenticate k pk nonce t
+        Just THAuthClient {serverPeerPubKey = k} -> Right $ TAAuthenticator $ C.cbAuthenticate k pk (C.cbNonce corrId) t
        Nothing -> Left TENoServerAuth
      C.SEd25519 -> sign pk
      C.SEd448 -> sign pk
@@ -98,7 +98,6 @@ data SMPClientAgent = SMPClientAgent
    agentQ :: TBQueue SMPClientAgentEvent,
    randomDrg :: TVar ChaChaDRG,
    smpClients :: TMap SMPServer SMPClientVar,
-    smpSessions :: TMap SessionId SMPClient,
    srvSubs :: TMap SMPServer (TMap SMPSub C.APrivateAuthKey),
    pendingSrvSubs :: TMap SMPServer (TMap SMPSub C.APrivateAuthKey),
    reconnections :: TVar [Async ()],
@@ -136,7 +135,6 @@ newSMPClientAgent agentCfg@SMPClientAgentConfig {msgQSize, agentQSize} randomDrg
  msgQ <- newTBQueue msgQSize
  agentQ <- newTBQueue agentQSize
  smpClients <- TM.empty
-  smpSessions <- TM.empty
  srvSubs <- TM.empty
  pendingSrvSubs <- TM.empty
  reconnections <- newTVar []
@@ -149,7 +147,6 @@ newSMPClientAgent agentCfg@SMPClientAgentConfig {msgQSize, agentQSize} randomDrg
        agentQ,
        randomDrg,
        smpClients,
-        smpSessions,
        srvSubs,
        pendingSrvSubs,
        reconnections,
@@ -158,7 +155,7 @@ newSMPClientAgent agentCfg@SMPClientAgentConfig {msgQSize, agentQSize} randomDrg
      }

 getSMPServerClient' :: SMPClientAgent -> SMPServer -> ExceptT SMPClientError IO SMPClient
-getSMPServerClient' ca@SMPClientAgent {agentCfg, smpClients, smpSessions, msgQ, randomDrg, workerSeq} srv =
+getSMPServerClient' ca@SMPClientAgent {agentCfg, smpClients, msgQ, randomDrg, workerSeq} srv =
  atomically getClientVar >>= either newSMPClient waitForSMPClient
  where
    getClientVar :: STM (Either SMPClientVar SMPClientVar)
@@ -181,9 +178,7 @@ getSMPServerClient' ca@SMPClientAgent {agentCfg, smpClients, smpSessions, msgQ,
          tryE (connectClient v) >>= \r -> case r of
            Right smp -> do
              logInfo . decodeUtf8 $ "Agent connected to " <> showServer srv
-              atomically $ do
-                putTMVar (sessionVar v) r
-                TM.insert (sessionId $ thParams smp) smp smpSessions
+              atomically $ putTMVar (sessionVar v) r
              successAction smp
            Left e -> do
              if e == PCENetworkError || e == PCEResponseTimeout
@@ -205,14 +200,13 @@ getSMPServerClient' ca@SMPClientAgent {agentCfg, smpClients, smpSessions, msgQ,
    connectClient v = ExceptT $ getProtocolClient randomDrg (1, srv, Nothing) (smpCfg agentCfg) (Just msgQ) (clientDisconnected v)

    clientDisconnected :: SMPClientVar -> SMPClient -> IO ()
-    clientDisconnected v smp = do
-      removeClientAndSubs v smp >>= (`forM_` serverDown)
+    clientDisconnected v _ = do
+      removeClientAndSubs v >>= (`forM_` serverDown)
      logInfo . decodeUtf8 $ "Agent disconnected from " <> showServer srv

-    removeClientAndSubs :: SMPClientVar -> SMPClient -> IO (Maybe (Map SMPSub C.APrivateAuthKey))
-    removeClientAndSubs v smp = atomically $ do
+    removeClientAndSubs :: SMPClientVar -> IO (Maybe (Map SMPSub C.APrivateAuthKey))
+    removeClientAndSubs v = atomically $ do
      removeSessVar v srv smpClients
-      TM.delete (sessionId $ thParams smp) smpSessions
      TM.lookupDelete srv (srvSubs ca) >>= mapM updateSubs
      where
        updateSubs sVar = do
@@ -277,9 +271,6 @@ getSMPServerClient' ca@SMPClientAgent {agentCfg, smpClients, smpSessions, msgQ,
    notify :: SMPClientAgentEvent -> IO ()
    notify evt = atomically $ writeTBQueue (agentQ ca) evt

-lookupSMPServerClient :: SMPClientAgent -> SessionId -> STM (Maybe SMPClient)
-lookupSMPServerClient SMPClientAgent {smpSessions} sessId = TM.lookup sessId smpSessions
-
 closeSMPClientAgent :: SMPClientAgent -> IO ()
 closeSMPClientAgent c = do
  closeSMPServerClients c
@@ -4,20 +4,9 @@
 module Simplex.Messaging.Compression where

 import qualified Codec.Compression.Zstd as Z1
-import qualified Codec.Compression.Zstd.FFI as Z
-import Control.Monad (forM)
-import Control.Monad.Except
-import Control.Monad.IO.Class
 import Data.ByteString (ByteString)
 import qualified Data.ByteString as B
-import qualified Data.ByteString.Unsafe as B
-import Data.Either (fromRight)
-import Data.List.NonEmpty (NonEmpty)
-import Foreign
-import Foreign.C.Types
-import GHC.IO (unsafePerformIO)
 import Simplex.Messaging.Encoding
-import UnliftIO.Exception (bracket)

 data Compressed
  = -- | Short messages are left intact to skip copying and FFI festivities.
@@ -42,49 +31,15 @@ instance Encoding Compressed where
      '1' -> Compressed <$> smpP
      x -> fail $ "unknown Compressed tag: " <> show x

-- | Compress as single chunk using stack-allocated context.
 compress1 :: ByteString -> Compressed
 compress1 bs
  | B.length bs <= maxLengthPassthrough = Passthrough bs
  | otherwise = Compressed . Large $ Z1.compress compressionLevel bs

-type CompressCtx = (Ptr Z.CCtx, Ptr CChar, CSize)
-
-withCompressCtx :: CSize -> (CompressCtx -> IO a) -> IO a
-withCompressCtx scratchSize action =
-  bracket Z.createCCtx Z.freeCCtx $ \cctx ->
-    allocaBytes (fromIntegral scratchSize) $ \scratchPtr ->
-      action (cctx, scratchPtr, scratchSize)
-
-- | Compress bytes, falling back to Passthrough in case of some internal error.
-compress :: CompressCtx -> ByteString -> IO Compressed
-compress ctx bs = fromRight (Passthrough bs) <$> compress_ ctx bs
-
-compress_ :: CompressCtx -> ByteString -> IO (Either String Compressed)
-compress_ (cctx, scratchPtr, scratchSize) bs
-  | B.length bs <= maxLengthPassthrough = pure . Right $ Passthrough bs
-  | otherwise =
-      B.unsafeUseAsCStringLen bs $ \(sourcePtr, sourceSize) -> runExceptT $ do
-        -- should not fail, unless input buffer is too short
-        dstSize <- ExceptT $ Z.checkError $ Z.compressCCtx cctx scratchPtr scratchSize sourcePtr (fromIntegral sourceSize) compressionLevel
-        liftIO $ Compressed . Large <$> B.packCStringLen (scratchPtr, fromIntegral dstSize)
-
-type DecompressCtx = (Ptr Z.DCtx, Ptr CChar, CSize)
-
-withDecompressCtx :: Int -> (DecompressCtx -> IO a) -> IO a
-withDecompressCtx maxUnpackedSize action =
-  bracket Z.createDCtx Z.freeDCtx $ \dctx ->
-    allocaBytes maxUnpackedSize $ \scratchPtr ->
-      action (dctx, scratchPtr, fromIntegral maxUnpackedSize)
-
-decompress :: DecompressCtx -> Compressed -> IO (Either String ByteString)
-decompress (dctx, scratchPtr, scratchSize) = \case
-  Passthrough bs -> pure $ Right bs
-  Compressed (Large bs) ->
-    B.unsafeUseAsCStringLen bs $ \(sourcePtr, sourceSize) -> do
-      res <- Z.checkError $ Z.decompressDCtx dctx scratchPtr scratchSize sourcePtr (fromIntegral sourceSize)
-      forM res $ \dstSize -> B.packCStringLen (scratchPtr, fromIntegral dstSize)
-
-decompressBatch :: Int -> NonEmpty Compressed -> NonEmpty (Either String ByteString)
-decompressBatch maxUnpackedSize items = unsafePerformIO $ withDecompressCtx maxUnpackedSize $ forM items . decompress
-{-# NOINLINE decompressBatch #-} -- prevent double-evaluation under unsafePerformIO
+decompress1 :: Compressed -> Either String ByteString
+decompress1 = \case
+  Passthrough bs -> Right bs
+  Compressed (Large bs) -> case Z1.decompress bs of
+    Z1.Error e -> Left e
+    Z1.Skip -> Right mempty
+    Z1.Decompress bs' -> Right bs'
@@ -141,7 +141,6 @@ module Simplex.Messaging.Crypto
    sbEncrypt_,
    cbNonce,
    randomCbNonce,
-    reverseNonce,

    -- * NaCl crypto_secretbox
    SbKey (unSbKey),
@@ -757,8 +756,6 @@ data Signature (a :: Algorithm) where
  SignatureEd25519 :: Ed25519.Signature -> Signature Ed25519
  SignatureEd448 :: Ed448.Signature -> Signature Ed448

-deriving instance Eq (Signature a)
-
 deriving instance Show (Signature a)

 data ASignature
@@ -1293,9 +1290,6 @@ randomCbNonce = fmap CryptoBoxNonce . randomBytes 24
 randomBytes :: Int -> TVar ChaChaDRG -> STM ByteString
 randomBytes n gVar = stateTVar gVar $ randomBytesGenerate n

-reverseNonce :: CbNonce -> CbNonce
-reverseNonce (CryptoBoxNonce s) = CryptoBoxNonce (B.reverse s)
-
 instance Encoding CbNonce where
  smpEncode = unCbNonce
  smpP = CryptoBoxNonce <$> A.take 24
@@ -143,16 +143,11 @@ kdfX3DHE2EEncryptVersion = VersionE2E 2
 pqRatchetE2EEncryptVersion :: VersionE2E
 pqRatchetE2EEncryptVersion = VersionE2E 3

-- TODO v5.7 increase to 3
 currentE2EEncryptVersion :: VersionE2E
-currentE2EEncryptVersion = VersionE2E 2
+currentE2EEncryptVersion = VersionE2E 3

-- TODO v5.7 remove dependency of version range on whether PQ encryption is used
-supportedE2EEncryptVRange :: PQSupport -> VersionRangeE2E
-supportedE2EEncryptVRange pq =
-  mkVersionRange kdfX3DHE2EEncryptVersion $ case pq of 
-    PQSupportOn -> pqRatchetE2EEncryptVersion
-    PQSupportOff -> currentE2EEncryptVersion
+supportedE2EEncryptVRange :: VersionRangeE2E
+supportedE2EEncryptVRange = mkVersionRange kdfX3DHE2EEncryptVersion currentE2EEncryptVersion

 data RatchetKEMState
  = RKSProposed -- only KEM encapsulation key
@@ -10,7 +10,7 @@ import Data.Word (Word16)
 import Simplex.Messaging.Client
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Notifications.Protocol
-import Simplex.Messaging.Notifications.Transport (NTFVersion, supportedClientNTFVRange)
+import Simplex.Messaging.Notifications.Transport (NTFVersion, supportedClientNTFVRange, supportedNTFHandshakes)
 import Simplex.Messaging.Protocol (ErrorType)
 import Simplex.Messaging.Util (bshow)

@@ -19,7 +19,7 @@ type NtfClient = ProtocolClient NTFVersion ErrorType NtfResponse
 type NtfClientError = ProtocolClientError ErrorType

 defaultNTFClientConfig :: ProtocolClientConfig NTFVersion
-defaultNTFClientConfig = defaultClientConfig supportedClientNTFVRange
+defaultNTFClientConfig = defaultClientConfig (Just supportedNTFHandshakes) supportedClientNTFVRange

 ntfRegisterToken :: NtfClient -> C.APrivateAuthKey -> NewNtfEntity 'Token -> ExceptT NtfClientError IO (NtfTokenId, C.PublicKeyX25519)
 ntfRegisterToken c pKey newTkn =
@@ -152,7 +152,7 @@ instance Encoding ANewNtfEntity where
 instance Protocol NTFVersion ErrorType NtfResponse where
  type ProtoCommand NtfResponse = NtfCmd
  type ProtoType NtfResponse = 'PNTF
-  protocolClientHandshake = ntfClientHandshake
+  protocolClientHandshake c _ks = ntfClientHandshake c
  protocolPing = NtfCmd SSubscription PING
  protocolError = \case
    NRErr e -> Just e
@@ -218,7 +218,7 @@ ntfSubscriber NtfSubscriber {smpSubscribers, newSubQ, smpAgent = ca@SMPClientAge

    receiveSMP :: M ()
    receiveSMP = forever $ do
-      ((_, srv, _), _, _, ntfId, msg) <- atomically $ readTBQueue msgQ
+      ((_, srv, _), _, _, _, ntfId, msg) <- atomically $ readTBQueue msgQ
      let smpQueue = SMPQueueNtf srv ntfId
      case msg of
        SMP.NMSG nmsgNonce encNMsgMeta -> do
@@ -34,7 +34,7 @@ import Simplex.Messaging.Server.Expiration
 import Simplex.Messaging.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
 import Simplex.Messaging.Transport (ATransport, THandleParams, TransportPeer (..))
-import Simplex.Messaging.Transport.Server (TransportServerConfig, loadFingerprint, loadTLSServerParams)
+import Simplex.Messaging.Transport.Server (TransportServerConfig, alpn, loadFingerprint, loadTLSServerParams)
 import System.IO (IOMode (..))
 import System.Mem.Weak (Weak)
 import UnliftIO.STM
@@ -84,7 +84,7 @@ data NtfEnv = NtfEnv
  }

 newNtfServerEnv :: NtfServerConfig -> IO NtfEnv
-newNtfServerEnv config@NtfServerConfig {subQSize, pushQSize, smpAgentCfg, apnsConfig, storeLogFile, caCertificateFile, certificateFile, privateKeyFile} = do
+newNtfServerEnv config@NtfServerConfig {subQSize, pushQSize, smpAgentCfg, apnsConfig, storeLogFile, caCertificateFile, certificateFile, privateKeyFile, transportConfig} = do
  random <- liftIO C.newRandom
  store <- atomically newNtfStore
  logInfo "restoring subscriptions..."
@@ -92,7 +92,7 @@ newNtfServerEnv config@NtfServerConfig {subQSize, pushQSize, smpAgentCfg, apnsCo
  logInfo "restored subscriptions"
  subscriber <- atomically $ newNtfSubscriber subQSize smpAgentCfg random
  pushServer <- atomically $ newNtfPushServer pushQSize apnsConfig
-  tlsServerParams <- liftIO $ loadTLSServerParams caCertificateFile certificateFile privateKeyFile
+  tlsServerParams <- liftIO $ loadTLSServerParams caCertificateFile certificateFile privateKeyFile (alpn transportConfig)
  Fingerprint fp <- liftIO $ loadFingerprint caCertificateFile
  serverStats <- atomically . newNtfServerStats =<< liftIO getCurrentTime
  pure NtfEnv {config, subscriber, pushServer, store, storeLog, random, tlsServerParams, serverIdentity = C.KeyHash fp, serverStats}
@@ -13,13 +13,12 @@ import Data.Maybe (fromMaybe)
 import qualified Data.Text as T
 import Network.Socket (HostName)
 import Options.Applicative
-import Simplex.Messaging.Client (ProtocolClientConfig (..))
-import Simplex.Messaging.Client.Agent (SMPClientAgentConfig (..), defaultSMPClientAgentConfig)
+import Simplex.Messaging.Client.Agent (defaultSMPClientAgentConfig)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Notifications.Server (runNtfServer)
 import Simplex.Messaging.Notifications.Server.Env (NtfServerConfig (..), defaultInactiveClientExpiration)
 import Simplex.Messaging.Notifications.Server.Push.APNS (defaultAPNSPushClientConfig)
-import Simplex.Messaging.Notifications.Transport (supportedServerNTFVRange)
+import Simplex.Messaging.Notifications.Transport (supportedNTFHandshakes, supportedServerNTFVRange)
 import Simplex.Messaging.Protocol (ProtoServerWithAuth (..), pattern NtfServer)
 import Simplex.Messaging.Server.CLI
 import Simplex.Messaging.Server.Expiration
@@ -31,9 +30,6 @@ import System.FilePath (combine)
 import System.IO (BufferMode (..), hSetBuffering, stderr, stdout)
 import Text.Read (readMaybe)

-defaultSMPBatchDelay :: Int
-defaultSMPBatchDelay = 10000
-
 ntfServerCLI :: FilePath -> FilePath -> IO ()
 ntfServerCLI cfgPath logPath =
  getCliCommand' (cliCommandP cfgPath logPath iniFile) serverVersion >>= \case
@@ -87,9 +83,7 @@ ntfServerCLI cfgPath logPath =
               \# host is only used to print server address on start\n"
            <> ("host: " <> host <> "\n")
            <> ("port: " <> defaultServerPort <> "\n")
-            <> "log_tls_errors: off\n\
-               \# delay between command batches sent to SMP relays (microseconds), 0 to disable\n"
-            <> ("smp_batch_delay: " <> show defaultSMPBatchDelay <> "\n")
+            <> "log_tls_errors: off\n"
            <> "websockets: off\n\n\
               \[INACTIVE_CLIENTS]\n\
               \# TTL and interval to check inactive clients\n\
@@ -111,8 +105,6 @@ ntfServerCLI cfgPath logPath =
        enableStoreLog = settingIsOn "STORE_LOG" "enable" ini
        logStats = settingIsOn "STORE_LOG" "log_stats" ini
        c = combine cfgPath . ($ defaultX509Config)
-        smpBatchDelay = readIniDefault defaultSMPBatchDelay "TRANSPORT" "smp_batch_delay" ini
-        batchDelay = if smpBatchDelay <= 0 then Nothing else Just smpBatchDelay
        serverConfig =
          NtfServerConfig
            { transports = iniTransports ini,
@@ -121,7 +113,7 @@ ntfServerCLI cfgPath logPath =
              clientQSize = 64,
              subQSize = 512,
              pushQSize = 1048,
-              smpAgentCfg = defaultSMPClientAgentConfig {smpCfg = (smpCfg defaultSMPClientAgentConfig) {batchDelay}},
+              smpAgentCfg = defaultSMPClientAgentConfig,
              apnsConfig = defaultAPNSPushClientConfig,
              subsBatchSize = 900,
              inactiveClientExpiration =
@@ -141,7 +133,8 @@ ntfServerCLI cfgPath logPath =
              ntfServerVRange = supportedServerNTFVRange,
              transportConfig =
                defaultTransportServerConfig
-                  { logTLSErrors = fromMaybe False $ iniOnOff "TRANSPORT" "log_tls_errors" ini
+                  { logTLSErrors = fromMaybe False $ iniOnOff "TRANSPORT" "log_tls_errors" ini,
+                    alpn = Just supportedNTFHandshakes
                  }
            }

@@ -44,17 +44,23 @@ authBatchCmdsNTFVersion :: VersionNTF
 authBatchCmdsNTFVersion = VersionNTF 2

 currentClientNTFVersion :: VersionNTF
-currentClientNTFVersion = VersionNTF 1
+currentClientNTFVersion = VersionNTF 2

 currentServerNTFVersion :: VersionNTF
-currentServerNTFVersion = VersionNTF 1
+currentServerNTFVersion = VersionNTF 2

 supportedClientNTFVRange :: VersionRangeNTF
 supportedClientNTFVRange = mkVersionRange initialNTFVersion currentClientNTFVersion

+legacyServerNTFVRange :: VersionRangeNTF
+legacyServerNTFVRange = mkVersionRange initialNTFVersion initialNTFVersion
+
 supportedServerNTFVRange :: VersionRangeNTF
 supportedServerNTFVRange = mkVersionRange initialNTFVersion currentServerNTFVersion

+supportedNTFHandshakes :: [ALPN]
+supportedNTFHandshakes = ["ntf/1"]
+
 type THandleNTF c p = THandle NTFVersion c p

 data NtfServerHandshake = NtfServerHandshake
@@ -68,9 +74,7 @@ data NtfClientHandshake = NtfClientHandshake
  { -- | agreed SMP notifications server protocol version
    ntfVersion :: VersionNTF,
    -- | server identity - CA certificate fingerprint
-    keyHash :: C.KeyHash,
-    -- pub key to agree shared secret for entity ID encryption, shared secret for command authorization is agreed using per-queue keys.
-    authPubKey :: Maybe C.PublicKeyX25519
+    keyHash :: C.KeyHash
  }

 instance Encoding NtfServerHandshake where
@@ -95,39 +99,30 @@ authEncryptCmdsP :: VersionNTF -> Parser a -> Parser (Maybe a)
 authEncryptCmdsP v p = if v >= authBatchCmdsNTFVersion then Just <$> p else pure Nothing

 instance Encoding NtfClientHandshake where
-  smpEncode NtfClientHandshake {ntfVersion, keyHash, authPubKey} =
-    smpEncode (ntfVersion, keyHash) <> encodeNtfAuthPubKey ntfVersion authPubKey
+  smpEncode NtfClientHandshake {ntfVersion, keyHash} =
+    smpEncode (ntfVersion, keyHash)
  smpP = do
    (ntfVersion, keyHash) <- smpP
-    -- TODO drop SMP v6: remove special parser and make key non-optional
-    authPubKey <- ntfAuthPubKeyP ntfVersion
-    pure NtfClientHandshake {ntfVersion, keyHash, authPubKey}
-
-ntfAuthPubKeyP :: VersionNTF -> Parser (Maybe C.PublicKeyX25519)
-ntfAuthPubKeyP v = if v >= authBatchCmdsNTFVersion then Just <$> smpP else pure Nothing
-
-encodeNtfAuthPubKey :: VersionNTF -> Maybe C.PublicKeyX25519 -> ByteString
-encodeNtfAuthPubKey v k
-  | v >= authBatchCmdsNTFVersion = maybe "" smpEncode k
-  | otherwise = ""
+    pure NtfClientHandshake {ntfVersion, keyHash}

 -- | Notifcations server transport handshake.
 ntfServerHandshake :: forall c. Transport c => C.APrivateSignKey -> c -> C.KeyPairX25519 -> C.KeyHash -> VersionRangeNTF -> ExceptT TransportError IO (THandleNTF c 'TServer)
 ntfServerHandshake serverSignKey c (k, pk) kh ntfVRange = do
  let th@THandle {params = THandleParams {sessionId}} = ntfTHandle c
  let sk = C.signX509 serverSignKey $ C.publicToX509 k
-  sendHandshake th $ NtfServerHandshake {sessionId, ntfVersionRange = ntfVRange, authPubKey = Just sk}
+  let ntfVersionRange = maybe legacyServerNTFVRange (const ntfVRange) $ getSessionALPN c
+  sendHandshake th $ NtfServerHandshake {sessionId, ntfVersionRange, authPubKey = Just sk}
  getHandshake th >>= \case
-    NtfClientHandshake {ntfVersion = v, keyHash, authPubKey = k'}
+    NtfClientHandshake {ntfVersion = v, keyHash}
      | keyHash /= kh ->
          throwError $ TEHandshake IDENTITY
-      | v `isCompatible` ntfVRange ->
-          pure $ ntfThHandleServer th v pk k'
+      | v `isCompatible` ntfVersionRange ->
+          pure $ ntfThHandleServer th v pk
      | otherwise -> throwError $ TEHandshake VERSION

 -- | Notifcations server client transport handshake.
-ntfClientHandshake :: forall c. Transport c => c -> C.KeyPairX25519 -> C.KeyHash -> VersionRangeNTF -> ExceptT TransportError IO (THandleNTF c 'TClient)
-ntfClientHandshake c (k, pk) keyHash ntfVRange = do
+ntfClientHandshake :: forall c. Transport c => c -> C.KeyHash -> VersionRangeNTF -> ExceptT TransportError IO (THandleNTF c 'TClient)
+ntfClientHandshake c keyHash ntfVRange = do
  let th@THandle {params = THandleParams {sessionId}} = ntfTHandle c
  NtfServerHandshake {sessionId = sessId, ntfVersionRange, authPubKey = sk'} <- getHandshake th
  if sessionId /= sessId
@@ -138,18 +133,18 @@ ntfClientHandshake c (k, pk) keyHash ntfVRange = do
          serverKey <- getServerVerifyKey c
          pubKey <- C.verifyX509 serverKey signedKey
          (,(getServerCerts c, signedKey)) <$> (C.x509ToPublic (pubKey, []) >>= C.pubKey)
-        sendHandshake th $ NtfClientHandshake {ntfVersion = v, keyHash, authPubKey = Just k}
-        pure $ ntfThHandleClient th v pk ck_
+        sendHandshake th $ NtfClientHandshake {ntfVersion = v, keyHash}
+        pure $ ntfThHandleClient th v ck_
      Nothing -> throwError $ TEHandshake VERSION

-ntfThHandleServer :: forall c. THandleNTF c 'TServer -> VersionNTF -> C.PrivateKeyX25519 -> Maybe C.PublicKeyX25519 -> THandleNTF c 'TServer
-ntfThHandleServer th v pk k_ =
-  let thAuth = (\k -> THAuthServer {clientPeerPubKey = k, serverPrivKey = pk}) <$> k_
-   in ntfThHandle_ th v thAuth
+ntfThHandleServer :: forall c. THandleNTF c 'TServer -> VersionNTF -> C.PrivateKeyX25519 -> THandleNTF c 'TServer
+ntfThHandleServer th v pk =
+  let thAuth = THAuthServer {serverPrivKey = pk, sessSecret' = Nothing}
+   in ntfThHandle_ th v (Just thAuth)

-ntfThHandleClient :: forall c. THandleNTF c 'TClient -> VersionNTF -> C.PrivateKeyX25519 -> Maybe (C.PublicKeyX25519, (X.CertificateChain, X.SignedExact X.PubKey)) -> THandleNTF c 'TClient
-ntfThHandleClient th v pk ck_ =
-  let thAuth = (\(k, ck) -> THAuthClient {serverPeerPubKey = k, serverCertKey = ck, clientPrivKey = pk}) <$> ck_
+ntfThHandleClient :: forall c. THandleNTF c 'TClient -> VersionNTF -> Maybe (C.PublicKeyX25519, (X.CertificateChain, X.SignedExact X.PubKey)) -> THandleNTF c 'TClient
+ntfThHandleClient th v ck_ =
+  let thAuth = (\(k, ck) -> THAuthClient {serverPeerPubKey = k, serverCertKey = ck, sessSecret = Nothing}) <$> ck_
   in ntfThHandle_ th v thAuth

 ntfThHandle_ :: forall c p. THandleNTF c p -> VersionNTF -> Maybe (THandleAuth p) -> THandleNTF c p
@@ -43,8 +43,6 @@ module Simplex.Messaging.Protocol
  ( -- * SMP protocol parameters
    supportedSMPClientVRange,
    maxMessageLength,
-    paddedProxiedMsgLength,
-    paddedForwardedMsgLength,
    e2eEncConfirmationLength,
    e2eEncMessageLength,

@@ -58,7 +56,6 @@ module Simplex.Messaging.Protocol
    SubscriptionMode (..),
    Party (..),
    Cmd (..),
-    DirectParty,
    BrokerMsg (..),
    SParty (..),
    PartyI (..),
@@ -66,7 +63,6 @@ module Simplex.Messaging.Protocol
    ProtocolErrorType (..),
    ErrorType (..),
    CommandError (..),
-    ProxyError (..),
    Transmission,
    TransmissionAuth (..),
    SignedTransmission,
@@ -125,12 +121,6 @@ module Simplex.Messaging.Protocol
    EncNMsgMeta,
    SMPMsgMeta (..),
    NMsgMeta (..),
-    EncFwdResponse (..),
-    EncFwdTransmission (..),
-    EncResponse (..),
-    EncTransmission (..),
-    FwdResponse (..),
-    FwdTransmission (..),
    MsgFlags (..),
    initialSMPClientVersion,
    userProtocol,
@@ -198,10 +188,7 @@ import Data.String
 import Data.Time.Clock.System (SystemTime (..))
 import Data.Type.Equality
 import Data.Word (Word16)
-import qualified Data.X509 as X
 import GHC.TypeLits (ErrorMessage (..), TypeError, type (+))
-import qualified GHC.TypeLits as TE
-import qualified GHC.TypeLits as Type
 import Network.Socket (ServiceName)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding
@@ -244,20 +231,6 @@ supportedSMPClientVRange = mkVersionRange initialSMPClientVersion currentSMPClie
 maxMessageLength :: Int
 maxMessageLength = 16088

-- without signature works with min 16151 (fails with 16150)
-- with Ed448: 16265 (fails with 16264)
-- with Ed25519: 16215 (fails with 16214)
-- with X25519: 16232 (fails with 16231)
-paddedProxiedMsgLength :: Int
-paddedProxiedMsgLength = 16232
-
-- without signature works with min 16239 (fails with 16238)
-- with Ed448: 16353 (fails with 16352)
-- with Ed25519: 16303 (fails with 16302)
-- with X25519: 16320 (fails with 16319)
-paddedForwardedMsgLength :: Int
-paddedForwardedMsgLength = 16320
-
 type MaxMessageLen = 16088

 -- 16 extra bytes: 8 for timestamp and 8 for flags (7 flags and the space, only 1 flag is currently used)
@@ -265,13 +238,13 @@ type MaxRcvMessageLen = MaxMessageLen + 16 -- 16104, the padded size is 16106

 -- it is shorter to allow per-queue e2e encryption DH key in the "public" header
 e2eEncConfirmationLength :: Int
-e2eEncConfirmationLength = 15936
+e2eEncConfirmationLength = 15920 -- 15881 .. 15976

 e2eEncMessageLength :: Int
-e2eEncMessageLength = 16032
+e2eEncMessageLength = 16016 -- 16004 .. 16021

 -- | SMP protocol clients
-data Party = Recipient | Sender | Notifier | ProxiedClient
+data Party = Recipient | Sender | Notifier
  deriving (Show)

 -- | Singleton types for SMP protocol clients
@@ -279,13 +252,11 @@ data SParty :: Party -> Type where
  SRecipient :: SParty Recipient
  SSender :: SParty Sender
  SNotifier :: SParty Notifier
-  SProxiedClient :: SParty ProxiedClient

 instance TestEquality SParty where
  testEquality SRecipient SRecipient = Just Refl
  testEquality SSender SSender = Just Refl
  testEquality SNotifier SNotifier = Just Refl
-  testEquality SProxiedClient SProxiedClient = Just Refl
  testEquality _ _ = Nothing

 deriving instance Show (SParty p)
@@ -298,15 +269,6 @@ instance PartyI Sender where sParty = SSender

 instance PartyI Notifier where sParty = SNotifier

-instance PartyI ProxiedClient where sParty = SProxiedClient
-
-type family DirectParty (p :: Party) :: Constraint where
-  DirectParty Recipient = ()
-  DirectParty Sender = ()
-  DirectParty Notifier = ()
-  DirectParty p =
-    (Int ~ Bool, TypeError (Type.Text "Party " :<>: ShowType p :<>: Type.Text " is not direct"))
-
 -- | Type for client command of any participant.
 data Cmd = forall p. PartyI p => Cmd (SParty p) (Command p)

@@ -397,17 +359,6 @@ data Command (p :: Party) where
  PING :: Command Sender
  -- SMP notification subscriber commands
  NSUB :: Command Notifier
-  PRXY :: SMPServer -> Maybe BasicAuth -> Command ProxiedClient -- request a relay server connection by URI
-  -- Transmission to proxy:
-  -- - entity ID: ID of the session with relay returned in PKEY (response to PRXY)
-  -- - corrId: also used as a nonce to encrypt transmission to relay, corrId + 1 - from relay
-  -- - key (1st param in the command) is used to agree DH secret for this particular transmission and its response
-  -- Encrypted transmission should include session ID (tlsunique) from proxy-relay connection.
-  PFWD :: C.PublicKeyX25519 -> EncTransmission -> Command ProxiedClient -- use CorrId as CbNonce, client to proxy
-  -- Transmission forwarded to relay:
-  -- - entity ID: empty
-  -- - corrId: unique correlation ID between proxy and relay, also used as a nonce to encrypt forwarded transmission
-  RFWD :: EncFwdTransmission -> Command Sender -- use CorrId as CbNonce, proxy to relay

 deriving instance Show (Command p)

@@ -433,25 +384,6 @@ instance Encoding SubscriptionMode where
      'C' -> pure SMOnlyCreate
      _ -> fail "bad SubscriptionMode"

-newtype EncTransmission = EncTransmission ByteString
-  deriving (Show)
-
-data FwdTransmission = FwdTransmission
-  { fwdCorrId :: CorrId,
-    fwdKey :: C.PublicKeyX25519,
-    fwdTransmission :: EncTransmission
-  }
-
-instance Encoding FwdTransmission where
-  smpEncode FwdTransmission {fwdCorrId = CorrId corrId, fwdKey, fwdTransmission = EncTransmission t} =
-    smpEncode (corrId, fwdKey, Tail t)
-  smpP = do
-    (corrId, fwdKey, Tail t) <- smpP
-    pure FwdTransmission {fwdCorrId = CorrId corrId, fwdKey, fwdTransmission = EncTransmission t}
-
-newtype EncFwdTransmission = EncFwdTransmission ByteString
-  deriving (Show)
-
 data BrokerMsg where
  -- SMP broker messages (responses, client messages, notifications)
  IDS :: QueueIdsKeys -> BrokerMsg
@@ -461,10 +393,6 @@ data BrokerMsg where
  MSG :: RcvMessage -> BrokerMsg
  NID :: NotifierId -> RcvNtfPublicDhKey -> BrokerMsg
  NMSG :: C.CbNonce -> EncNMsgMeta -> BrokerMsg
-  -- Should include certificate chain
-  PKEY :: SessionId -> VersionRangeSMP -> (X.CertificateChain, X.SignedExact X.PubKey) -> 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
  END :: BrokerMsg
  OK :: BrokerMsg
  ERR :: ErrorType -> BrokerMsg
@@ -477,24 +405,6 @@ data RcvMessage = RcvMessage
  }
  deriving (Eq, Show)

-newtype EncFwdResponse = EncFwdResponse ByteString
-  deriving (Eq, Show)
-
-data FwdResponse = FwdResponse
-  { fwdCorrId :: CorrId,
-    fwdResponse :: EncResponse
-  }
-
-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)
-
 -- | received message without server/recipient encryption
 data Message
  = Message
@@ -657,9 +567,6 @@ data CommandTag (p :: Party) where
  DEL_ :: CommandTag Recipient
  SEND_ :: CommandTag Sender
  PING_ :: CommandTag Sender
-  PRXY_ :: CommandTag ProxiedClient
-  PFWD_ :: CommandTag ProxiedClient
-  RFWD_ :: CommandTag Sender
  NSUB_ :: CommandTag Notifier

 data CmdTag = forall p. PartyI p => CT (SParty p) (CommandTag p)
@@ -673,9 +580,6 @@ data BrokerMsgTag
  | MSG_
  | NID_
  | NMSG_
-  | PKEY_
-  | RRES_
-  | PRES_
  | END_
  | OK_
  | ERR_
@@ -703,9 +607,6 @@ instance PartyI p => Encoding (CommandTag p) where
    DEL_ -> "DEL"
    SEND_ -> "SEND"
    PING_ -> "PING"
-    PRXY_ -> "PRXY"
-    PFWD_ -> "PFWD"
-    RFWD_ -> "RFWD"
    NSUB_ -> "NSUB"
  smpP = messageTagP

@@ -722,9 +623,6 @@ instance ProtocolMsgTag CmdTag where
    "DEL" -> Just $ CT SRecipient DEL_
    "SEND" -> Just $ CT SSender SEND_
    "PING" -> Just $ CT SSender PING_
-    "PRXY" -> Just $ CT SProxiedClient PRXY_
-    "PFWD" -> Just $ CT SProxiedClient PFWD_
-    "RFWD" -> Just $ CT SSender RFWD_
    "NSUB" -> Just $ CT SNotifier NSUB_
    _ -> Nothing

@@ -741,9 +639,6 @@ instance Encoding BrokerMsgTag where
    MSG_ -> "MSG"
    NID_ -> "NID"
    NMSG_ -> "NMSG"
-    PKEY_ -> "PKEY"
-    RRES_ -> "RRES"
-    PRES_ -> "PRES"
    END_ -> "END"
    OK_ -> "OK"
    ERR_ -> "ERR"
@@ -756,9 +651,6 @@ instance ProtocolMsgTag BrokerMsgTag where
    "MSG" -> Just MSG_
    "NID" -> Just NID_
    "NMSG" -> Just NMSG_
-    "PKEY" -> Just PKEY_
-    "RRES" -> Just RRES_
-    "PRES" -> Just PRES_
    "END" -> Just END_
    "OK" -> Just OK_
    "ERR" -> Just ERR_
@@ -937,7 +829,7 @@ type family UserProtocol (p :: ProtocolType) :: Constraint where
  UserProtocol PSMP = ()
  UserProtocol PXFTP = ()
  UserProtocol a =
-    (Int ~ Bool, TypeError (TE.Text "Servers for protocol " :<>: ShowType a :<>: TE.Text " cannot be configured by the users"))
+    (Int ~ Bool, TypeError (Text "Servers for protocol " :<>: ShowType a :<>: Text " cannot be configured by the users"))

 userProtocol :: SProtocolType p -> Maybe (Dict (UserProtocol p))
 userProtocol = \case
@@ -1146,8 +1038,6 @@ data ErrorType
    SESSION
  | -- | SMP command is unknown or has invalid syntax
    CMD {cmdErr :: CommandError}
-  | -- | error from proxied relay
-    PROXY {proxyErr :: ProxyError}
  | -- | command authorization error - bad signature or non-existing SMP queue
    AUTH
  | -- | SMP queue capacity is exceeded on the server
@@ -1156,8 +1046,6 @@ data ErrorType
    NO_MSG
  | -- | sent message is too large (> maxMessageLength = 16088 bytes)
    LARGE_MSG
-  | -- | relay public key is expired
-    EXPIRED
  | -- | internal server error
    INTERNAL
  | -- | used internally, never returned by the server (to be removed)
@@ -1167,12 +1055,8 @@ data ErrorType
 instance StrEncoding ErrorType where
  strEncode = \case
    CMD e -> "CMD " <> bshow e
-    PROXY e -> "PROXY " <> bshow e
    e -> bshow e
-  strP =
-    "CMD " *> (CMD <$> parseRead1)
-      <|> "PROXY " *> (PROXY <$> parseRead1)
-      <|> parseRead1
+  strP = "CMD " *> (CMD <$> parseRead1) <|> parseRead1

 -- | SMP command error type.
 data CommandError
@@ -1190,22 +1074,6 @@ data CommandError
    NO_ENTITY
  deriving (Eq, Read, Show)

-- TODO keep error params
-data ProxyError
-  = -- | Correctly parsed SMP server ERR response.
-    -- This error is forwarded to the agent client as `ERR SMP err`.
-    PROTOCOL -- {protocolErr :: String}
-  | -- | Invalid server response that failed to parse.
-    -- Forwarded to the agent client as `ERR BROKER RESPONSE`.
-    RESPONSE -- {responseErr :: String}
-  | UNEXPECTED
-  | TIMEOUT
-  | NETWORK
-  | BAD_HOST
-  | NO_SESSION
-  | TRANSPORT -- {transportErr :: TransportError}
-  deriving (Eq, Read, Show)
-
 -- | SMP transmission parser.
 transmissionP :: THandleParams v p -> Parser RawTransmission
 transmissionP THandleParams {sessionId, implySessId} = do
@@ -1224,7 +1092,7 @@ transmissionP THandleParams {sessionId, implySessId} = do
 class (ProtocolEncoding v err msg, ProtocolEncoding v err (ProtoCommand msg), Show err, Show msg) => Protocol v err msg | msg -> v, msg -> err where
  type ProtoCommand msg = cmd | cmd -> msg
  type ProtoType msg = (sch :: ProtocolType) | sch -> msg
-  protocolClientHandshake :: forall c. Transport c => c -> C.KeyPairX25519 -> C.KeyHash -> VersionRange v -> ExceptT TransportError IO (THandle v c 'TClient)
+  protocolClientHandshake :: forall c. Transport c => c -> Maybe C.KeyPairX25519 -> C.KeyHash -> VersionRange v -> ExceptT TransportError IO (THandle v c 'TClient)
  protocolPing :: ProtoCommand msg
  protocolError :: msg -> Maybe err

@@ -1267,9 +1135,6 @@ instance PartyI p => ProtocolEncoding SMPVersion ErrorType (Command p) where
    SEND flags msg -> e (SEND_, ' ', flags, ' ', Tail msg)
    PING -> e PING_
    NSUB -> e NSUB_
-    PRXY host auth_ -> e (PRXY_, ' ', host, auth_)
-    PFWD pubKey (EncTransmission s) -> e (PFWD_, ' ', pubKey, Tail s)
-    RFWD (EncFwdTransmission s) -> e (RFWD_, ' ', Tail s)
    where
      e :: Encoding a => a -> ByteString
      e = smpEncode
@@ -1279,33 +1144,24 @@ instance PartyI p => ProtocolEncoding SMPVersion ErrorType (Command p) where
  fromProtocolError = fromProtocolError @SMPVersion @ErrorType @BrokerMsg
  {-# INLINE fromProtocolError #-}

-  checkCredentials (auth, _, entId, _) cmd = case cmd of
+  checkCredentials (auth, _, queueId, _) cmd = case cmd of
    -- NEW must have signature but NOT queue ID
    NEW {}
      | isNothing auth -> Left $ CMD NO_AUTH
-      | not (B.null entId) -> Left $ CMD HAS_AUTH
+      | not (B.null queueId) -> Left $ CMD HAS_AUTH
      | otherwise -> Right cmd
    -- SEND must have queue ID, signature is not always required
    SEND {}
-      | B.null entId -> Left $ CMD NO_ENTITY
+      | B.null queueId -> Left $ CMD NO_ENTITY
      | otherwise -> Right cmd
-    PING -> noAuthCmd
-    PRXY {} -> noAuthCmd
-    PFWD {}
-      | B.null entId -> Left $ CMD NO_ENTITY
-      | isNothing auth -> Right cmd
+    -- PING must not have queue ID or signature
+    PING
+      | isNothing auth && B.null queueId -> Right cmd
      | otherwise -> Left $ CMD HAS_AUTH
-    RFWD _ -> noAuthCmd
    -- other client commands must have both signature and queue ID
    _
-      | isNothing auth || B.null entId -> Left $ CMD NO_AUTH
+      | isNothing auth || B.null queueId -> Left $ CMD NO_AUTH
      | otherwise -> Right cmd
-    where
-      -- command must not have entity ID (queue or session ID) or signature
-      noAuthCmd :: Either ErrorType (Command p)
-      noAuthCmd
-        | isNothing auth && B.null entId = Right cmd
-        | otherwise = Left $ CMD HAS_AUTH

 instance ProtocolEncoding SMPVersion ErrorType Cmd where
  type Tag Cmd = CmdTag
@@ -1333,11 +1189,6 @@ instance ProtocolEncoding SMPVersion ErrorType Cmd where
      Cmd SSender <$> case tag of
        SEND_ -> SEND <$> _smpP <*> (unTail <$> _smpP)
        PING_ -> pure PING
-        RFWD_ -> RFWD <$> (EncFwdTransmission . unTail <$> _smpP)
-    CT SProxiedClient tag ->
-      Cmd SProxiedClient <$> case tag of
-        PFWD_ -> PFWD <$> _smpP <*> (EncTransmission . unTail <$> smpP)
-        PRXY_ -> PRXY <$> _smpP <*> smpP
    CT SNotifier NSUB_ -> pure $ Cmd SNotifier NSUB

  fromProtocolError = fromProtocolError @SMPVersion @ErrorType @BrokerMsg
@@ -1353,9 +1204,6 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where
      e (MSG_, ' ', msgId, Tail body)
    NID nId srvNtfDh -> e (NID_, ' ', nId, srvNtfDh)
    NMSG nmsgNonce encNMsgMeta -> e (NMSG_, ' ', nmsgNonce, encNMsgMeta)
-    PKEY sid vr (cert, key) -> e (PKEY_, ' ', sid, vr, C.encodeCertChain cert, C.SignedObject key)
-    RRES (EncFwdResponse encBlock) -> e (RRES_, ' ', Tail encBlock)
-    PRES (EncResponse encBlock) -> e (PRES_, ' ', Tail encBlock)
    END -> e END_
    OK -> e OK_
    ERR err -> e (ERR_, ' ', err)
@@ -1373,9 +1221,6 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where
    IDS_ -> IDS <$> (QIK <$> _smpP <*> smpP <*> smpP)
    NID_ -> NID <$> _smpP <*> smpP
    NMSG_ -> NMSG <$> _smpP <*> smpP
-    PKEY_ -> PKEY <$> _smpP <*> smpP <*> ((,) <$> C.certChainP <*> (C.getSignedExact <$> smpP))
-    RRES_ -> RRES <$> (EncFwdResponse . unTail <$> _smpP)
-    PRES_ -> PRES <$> (EncResponse . unTail <$> _smpP)
    END_ -> pure END
    OK_ -> pure OK
    ERR_ -> ERR <$> _smpP
@@ -1388,24 +1233,19 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where
    PEBlock -> BLOCK
  {-# INLINE fromProtocolError #-}

-  checkCredentials (_, _, entId, _) cmd = case cmd of
+  checkCredentials (_, _, queueId, _) cmd = case cmd of
    -- IDS response should not have queue ID
    IDS _ -> Right cmd
    -- ERR response does not always have queue ID
    ERR _ -> Right cmd
    -- PONG response must not have queue ID
-    PONG -> noEntityMsg
-    PKEY {} -> noEntityMsg
-    RRES _ -> noEntityMsg
+    PONG
+      | B.null queueId -> Right cmd
+      | otherwise -> Left $ CMD HAS_AUTH
    -- other broker responses must have queue ID
    _
-      | B.null entId -> Left $ CMD NO_ENTITY
+      | B.null queueId -> Left $ CMD NO_ENTITY
      | otherwise -> Right cmd
-    where
-      noEntityMsg :: Either ErrorType BrokerMsg
-      noEntityMsg
-        | B.null entId = Right cmd
-        | otherwise = Left $ CMD HAS_AUTH

 -- | Parse SMP protocol commands and broker messages
 parseProtocol :: forall v err msg. ProtocolEncoding v err msg => Version v -> ByteString -> Either err msg
@@ -1428,10 +1268,8 @@ instance Encoding ErrorType where
    BLOCK -> "BLOCK"
    SESSION -> "SESSION"
    CMD err -> "CMD " <> smpEncode err
-    PROXY err -> "PROXY " <> smpEncode err
    AUTH -> "AUTH"
    QUOTA -> "QUOTA"
-    EXPIRED -> "EXPIRED"
    NO_MSG -> "NO_MSG"
    LARGE_MSG -> "LARGE_MSG"
    INTERNAL -> "INTERNAL"
@@ -1442,10 +1280,8 @@ instance Encoding ErrorType where
      "BLOCK" -> pure BLOCK
      "SESSION" -> pure SESSION
      "CMD" -> CMD <$> _smpP
-      "PROXY" -> PROXY <$> _smpP
      "AUTH" -> pure AUTH
      "QUOTA" -> pure QUOTA
-      "EXPIRED" -> pure EXPIRED
      "NO_MSG" -> pure NO_MSG
      "LARGE_MSG" -> pure LARGE_MSG
      "INTERNAL" -> pure INTERNAL
@@ -1468,29 +1304,7 @@ instance Encoding CommandError where
      "NO_AUTH" -> pure NO_AUTH
      "HAS_AUTH" -> pure HAS_AUTH
      "NO_ENTITY" -> pure NO_ENTITY
-      "NO_QUEUE" -> pure NO_ENTITY -- for backward compatibility
-      _ -> fail "bad command error type"
-
-instance Encoding ProxyError where
-  smpEncode e = case e of
-    PROTOCOL -> "PROTOCOL"
-    RESPONSE -> "RESPONSE"
-    UNEXPECTED -> "UNEXPECTED"
-    TIMEOUT -> "TIMEOUT"
-    NETWORK -> "NETWORK"
-    BAD_HOST -> "BAD_HOST"
-    NO_SESSION -> "NO_SESSION"
-    TRANSPORT -> "TRANSPORT"
-  smpP =
-    A.takeTill (== ' ') >>= \case
-      "PROTOCOL" -> pure PROTOCOL
-      "RESPONSE" -> pure RESPONSE
-      "UNEXPECTED" -> pure UNEXPECTED
-      "TIMEOUT" -> pure TIMEOUT
-      "NETWORK" -> pure NETWORK
-      "BAD_HOST" -> pure BAD_HOST
-      "NO_SESSION" -> pure NO_SESSION
-      "TRANSPORT" -> pure TRANSPORT
+      "NO_QUEUE" -> pure NO_ENTITY
      _ -> fail "bad command error type"

 -- | Send signed SMP transmission to TCP transport.
@@ -1630,6 +1444,4 @@ $(J.deriveJSON defaultJSON ''MsgFlags)

 $(J.deriveJSON (sumTypeJSON id) ''CommandError)

-$(J.deriveJSON (sumTypeJSON id) ''ProxyError)
-
 $(J.deriveJSON (sumTypeJSON id) ''ErrorType)
@@ -13,6 +13,7 @@
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE TupleSections #-}
+{-# LANGUAGE TypeApplications #-}

 -- |
 -- Module      : Simplex.Messaging.Server
@@ -42,7 +43,6 @@ import Control.Monad
 import Control.Monad.Except
 import Control.Monad.IO.Unlift
 import Control.Monad.Reader
-import Control.Monad.Trans.Except
 import Crypto.Random
 import Data.Bifunctor (first)
 import Data.ByteString.Base64 (encode)
@@ -51,9 +51,10 @@ import qualified Data.ByteString.Char8 as B
 import qualified Data.ByteString.Lazy.Char8 as LB
 import Data.Either (fromRight, partitionEithers)
 import Data.Functor (($>))
+import qualified Data.HashMap.Strict as HM
 import Data.Int (Int64)
 import qualified Data.IntMap.Strict as IM
-import Data.List (intercalate)
+import Data.List (intercalate, mapAccumR)
 import Data.List.NonEmpty (NonEmpty)
 import qualified Data.List.NonEmpty as L
 import qualified Data.Map.Strict as M
@@ -68,10 +69,8 @@ import GHC.Stats (getRTSStats)
 import GHC.TypeLits (KnownNat)
 import Network.Socket (ServiceName, Socket, socketToHandle)
 import Simplex.Messaging.Agent.Lock
-import Simplex.Messaging.Client (ProtocolClient (thParams), forwardSMPMessage, smpProxyError)
-import Simplex.Messaging.Client.Agent (SMPClientAgent (..), SMPClientAgentEvent (..), getSMPServerClient', lookupSMPServerClient)
 import qualified Simplex.Messaging.Crypto as C
-import Simplex.Messaging.Encoding
+import Simplex.Messaging.Encoding (Encoding (smpEncode))
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol
 import Simplex.Messaging.Server.Control
@@ -93,7 +92,6 @@ import System.Exit (exitFailure)
 import System.IO (hPrint, hPutStrLn, hSetNewlineMode, universalNewlineMode)
 import System.Mem.Weak (deRefWeak)
 import UnliftIO (timeout)
-import UnliftIO.Async (mapConcurrently)
 import UnliftIO.Concurrent
 import UnliftIO.Directory (doesFileExist, renameFile)
 import UnliftIO.Exception
@@ -126,13 +124,11 @@ type M a = ReaderT Env IO a
 smpServer :: TMVar Bool -> ServerConfig -> M ()
 smpServer started cfg@ServerConfig {transports, transportConfig = tCfg} = do
  s <- asks server
-  pa <- asks proxyAgent
  expired <- restoreServerMessages
  restoreServerStats expired
  raceAny_
    ( serverThread s "server subscribedQ" subscribedQ subscribers subscriptions cancelSub
        : serverThread s "server ntfSubscribedQ" ntfSubscribedQ Env.notifiers ntfSubscriptions (\_ -> pure ())
-        : receiveFromProxyAgent pa
        : map runServer transports <> expireMessagesThread_ cfg <> serverStatsThread_ cfg <> controlPortThread_ cfg
    )
    `finally` withLock' (savingLock s) "final" (saveServer False)
@@ -185,19 +181,6 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg} = do
          mkWeakThreadId t >>= atomically . modifyTVar' (endThreads c) . IM.insert tId
          atomically $ TM.lookupDelete qId (clientSubs c)

-    receiveFromProxyAgent :: ProxyAgent -> M ()
-    receiveFromProxyAgent ProxyAgent {smpAgent = SMPClientAgent {agentQ}} =
-      forever $
-        atomically (readTBQueue agentQ) >>= \case
-          CAConnected srv -> logInfo $ "SMP server connected " <> showServer' srv
-          CADisconnected srv [] -> logInfo $ "SMP server disconnected " <> showServer' srv
-          CADisconnected srv subs -> logError $ "SMP server disconnected " <> showServer' srv <> " / subscriptions: " <> tshow (length subs)
-          CAReconnected srv -> logInfo $ "SMP server reconnected " <> showServer' srv
-          CAResubscribed srv subs -> logError $ "SMP server resubscribed " <> showServer' srv <> " / subscriptions: " <> tshow (length subs)
-          CASubError srv errs -> logError $ "SMP server subscription errors " <> showServer' srv <> " / errors: " <> tshow (length errs)
-      where
-        showServer' = decodeLatin1 . strEncode . host
-
    expireMessagesThread_ :: ServerConfig -> [M ()]
    expireMessagesThread_ ServerConfig {messageExpiration = Just msgExp} = [expireMessages msgExp]
    expireMessagesThread_ _ = []
@@ -333,7 +316,7 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg} = do
              CPResume -> withAdminRole $ hPutStrLn h "resume not implemented"
              CPClients -> withAdminRole $ do
                active <- unliftIO u (asks clients) >>= readTVarIO
-                hPutStrLn h "clientId,sessionId,connected,createdAt,rcvActiveAt,sndActiveAt,age,subscriptions"
+                hPutStrLn h $ "clientId,sessionId,connected,createdAt,rcvActiveAt,sndActiveAt,age,subscriptions"
                forM_ (IM.toList active) $ \(cid, Client {sessionId, connected, createdAt, rcvActiveAt, sndActiveAt, subscriptions}) -> do
                  connected' <- bshow <$> readTVarIO connected
                  rcvActiveAt' <- strEncode <$> readTVarIO rcvActiveAt
@@ -429,7 +412,7 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg} = do
                    hPutStrLn h "AUTH"

 runClientTransport :: Transport c => THandleSMP c 'TServer -> M ()
-runClientTransport th@THandle {params = thParams@THandleParams {thVersion, sessionId}} = do
+runClientTransport h@THandle {params = THandleParams {thVersion, sessionId}} = do
  q <- asks $ tbqSize . config
  ts <- liftIO getSystemTime
  active <- asks clients
@@ -440,11 +423,12 @@ runClientTransport th@THandle {params = thParams@THandleParams {thVersion, sessi
    pure new
  s <- asks server
  expCfg <- asks $ inactiveClientExpiration . config
+  th <- newMVar h -- put TH under a fair lock to interleave messages and command responses
  labelMyThread . B.unpack $ "client $" <> encode sessionId
-  raceAny_ ([liftIO $ send th c, client thParams c s, receive th c] <> disconnectThread_ c expCfg)
+  raceAny_ ([liftIO $ send th c, liftIO $ sendMsg th c, client c s, receive h c] <> disconnectThread_ c expCfg)
    `finally` clientDisconnected c
  where
-    disconnectThread_ c (Just expCfg) = [liftIO $ disconnectTransport th (rcvActiveAt c) (sndActiveAt c) expCfg (noSubscriptions c)]
+    disconnectThread_ c (Just expCfg) = [liftIO $ disconnectTransport h (rcvActiveAt c) (sndActiveAt c) expCfg (noSubscriptions c)]
    disconnectThread_ _ _ = []
    noSubscriptions c = atomically $ (&&) <$> TM.null (subscriptions c) <*> TM.null (ntfSubscriptions c)

@@ -477,40 +461,61 @@ cancelSub sub =
    _ -> return ()

 receive :: Transport c => THandleSMP c 'TServer -> Client -> M ()
-receive th@THandle {params = THandleParams {thAuth}} Client {rcvQ, sndQ, rcvActiveAt, sessionId} = do
+receive h@THandle {params = THandleParams {thAuth}} Client {rcvQ, sndQ, rcvActiveAt, sessionId} = do
  labelMyThread . B.unpack $ "client $" <> encode sessionId <> " receive"
  forever $ do
-    ts <- L.toList <$> liftIO (tGet th)
+    ts <- L.toList <$> liftIO (tGet h)
    atomically . writeTVar rcvActiveAt =<< liftIO getSystemTime
-    (errs, cmds) <- partitionEithers <$> mapM cmdAction ts
-    write sndQ errs
-    write rcvQ cmds
+    as <- partitionEithers <$> mapM cmdAction ts
+    write sndQ $ fst as
+    write rcvQ $ snd as
  where
    cmdAction :: SignedTransmission ErrorType Cmd -> M (Either (Transmission BrokerMsg) (Maybe QueueRec, Transmission Cmd))
-    cmdAction (tAuth, authorized, (corrId, entId, cmdOrError)) =
+    cmdAction (tAuth, authorized, (corrId, queueId, cmdOrError)) =
      case cmdOrError of
-        Left e -> pure $ Left (corrId, entId, ERR e)
-        Right cmd -> verified <$> verifyTransmission ((,C.cbNonce (bs corrId)) <$> thAuth) tAuth authorized entId cmd
+        Left e -> pure $ Left (corrId, queueId, ERR e)
+        Right cmd -> verified <$> verifyTransmission ((,C.cbNonce (bs corrId)) <$> thAuth) tAuth authorized queueId cmd
          where
            verified = \case
-              VRVerified qr -> Right (qr, (corrId, entId, cmd))
-              VRFailed -> Left (corrId, entId, ERR AUTH)
+              VRVerified qr -> Right (qr, (corrId, queueId, cmd))
+              VRFailed -> Left (corrId, queueId, ERR AUTH)
    write q = mapM_ (atomically . writeTBQueue q) . L.nonEmpty

-send :: Transport c => THandleSMP c 'TServer -> Client -> IO ()
-send h@THandle {params} Client {sndQ, sessionId, sndActiveAt} = do
+send :: Transport c => MVar (THandleSMP c 'TServer) -> Client -> IO ()
+send th c@Client {sndQ, msgQ, sessionId} = do
  labelMyThread . B.unpack $ "client $" <> encode sessionId <> " send"
-  forever $ do
-    ts <- atomically $ L.sortWith tOrder <$> readTBQueue sndQ
-    -- TODO we can authorize responses as well
-    void . liftIO . tPut h $ L.map (\t -> Right (Nothing, encodeTransmission params t)) ts
-    atomically . writeTVar sndActiveAt =<< liftIO getSystemTime
+  forever $ atomically (readTBQueue sndQ) >>= sendTransmissions
  where
-    tOrder :: Transmission BrokerMsg -> Int
-    tOrder (_, _, cmd) = case cmd of
-      MSG {} -> 0
-      NMSG {} -> 0
-      _ -> 1
+    sendTransmissions :: NonEmpty (Transmission BrokerMsg) -> IO ()
+    sendTransmissions ts
+      | L.length ts <= 2 = tSend th c ts
+      | otherwise = do
+          let (msgs_, ts') = mapAccumR splitMessages [] ts
+          -- If the request had batched subscriptions (L.length ts > 2)
+          -- this will reply OK to all SUBs in the first batched transmission,
+          -- to reduce client timeouts.
+          tSend th c ts'
+          -- After that all messages will be sent in separate transmissions,
+          -- without any client response timeouts, and allowing them to interleave
+          -- with other requests responses.
+          mapM_ (atomically . writeTBQueue msgQ) $ L.nonEmpty msgs_
+      where
+        splitMessages :: [Transmission BrokerMsg] -> Transmission BrokerMsg -> ([Transmission BrokerMsg], Transmission BrokerMsg)
+        splitMessages msgs t@(corrId, entId, cmd) = case cmd of
+          -- replace MSG response with OK, accumulating MSG in a separate list.
+          MSG {} -> ((CorrId "", entId, cmd) : msgs, (corrId, entId, OK))
+          _ -> (msgs, t)
+
+sendMsg :: Transport c => MVar (THandleSMP c 'TServer) -> Client -> IO ()
+sendMsg th c@Client {msgQ, sessionId} = do
+  labelMyThread . B.unpack $ "client $" <> encode sessionId <> " sendMsg"
+  forever $ atomically (readTBQueue msgQ) >>= mapM_ (\t -> tSend th c [t])
+
+tSend :: Transport c => MVar (THandleSMP c 'TServer) -> Client -> NonEmpty (Transmission BrokerMsg) -> IO ()
+tSend th Client {sndActiveAt} ts = do
+  withMVar th $ \h@THandle {params} ->
+    void . tPut h $ L.map (\t -> Right (Nothing, encodeTransmission params t)) ts
+  atomically . writeTVar sndActiveAt =<< liftIO getSystemTime

 disconnectTransport :: Transport c => THandle v c 'TServer -> TVar SystemTime -> TVar SystemTime -> ExpirationConfig -> IO Bool -> IO ()
 disconnectTransport THandle {connection, params = THandleParams {sessionId}} rcvActiveAt sndActiveAt expCfg noSubscriptions = do
@@ -537,22 +542,26 @@ verifyTransmission :: Maybe (THandleAuth 'TServer, C.CbNonce) -> Maybe Transmiss
 verifyTransmission auth_ tAuth authorized queueId cmd =
  case cmd of
    Cmd SRecipient (NEW k _ _ _) -> pure $ Nothing `verifiedWith` k
-    Cmd SRecipient _ -> verifyQueue (\q -> Just q `verifiedWith` recipientKey q) <$> get SRecipient
+    Cmd SRecipient _ -> do
+      QueueStore {recipientKeys} <- asks queueStore
+      (queueId `HM.lookup`) <$> readTVarIO recipientKeys >>= \case
+        Nothing -> pure $! dummyVerify
+        Just rKey -> if verify rKey then slowIO >> get SRecipient >>= either (\_notGonnaHappenUnlessDeletedWhileCheckingAuth -> pure VRFailed) (pure . VRVerified . Just) else pure VRFailed
    -- SEND will be accepted without authorization before the queue is secured with KEY command
    Cmd SSender SEND {} -> verifyQueue (\q -> Just q `verified` maybe (isNothing tAuth) verify (senderKey q)) <$> get SSender
    Cmd SSender PING -> pure $ VRVerified Nothing
-    Cmd SSender RFWD {} -> pure $ VRVerified Nothing
    -- NSUB will not be accepted without authorization
-    Cmd SNotifier NSUB -> verifyQueue (\q -> maybe dummyVerify (\n -> Just q `verifiedWith` notifierKey n) (notifier q)) <$> get SNotifier
-    Cmd SProxiedClient _ -> pure $ VRVerified Nothing
+    Cmd SNotifier NSUB -> verifyQueue (\q -> maybe dummyVerify (Just q `verifiedWith`) (notifierKey <$> notifier q)) <$> get SNotifier
  where
    verify = verifyCmdAuthorization auth_ tAuth authorized
    dummyVerify = verify (dummyAuthKey tAuth) `seq` VRFailed
    verifyQueue :: (QueueRec -> VerificationResult) -> Either ErrorType QueueRec -> VerificationResult
-    verifyQueue = either (const dummyVerify)
+    verifyQueue = either (\_ -> dummyVerify)
    verified q cond = if cond then VRVerified q else VRFailed
    verifiedWith q k = q `verified` verify k
-    get :: DirectParty p => SParty p -> M (Either ErrorType QueueRec)
+    slowIO :: M ()
+    slowIO = liftIO $ threadDelay 100000 -- XXX: Some thumb twiddling to prove that fetching queue data doesn't allow to distinguish bad key and non-existent queue.
+    get :: SParty p -> M (Either ErrorType QueueRec)
    get party = do
      st <- asks queueStore
      atomically $ getQueue st party queueId
@@ -602,55 +611,25 @@ dummyKeyEd448 = "MEMwBQYDK2VxAzoA6ibQc9XpkSLtwrf7PLvp81qW/etiumckVFImCMRdftcG/Xo
 dummyKeyX25519 :: C.PublicKey 'C.X25519
 dummyKeyX25519 = "MCowBQYDK2VuAyEA4JGSMYht18H4mas/jHeBwfcM7jLwNYJNOAhi2/g4RXg="

-client :: THandleParams SMPVersion 'TServer -> Client -> Server -> M ()
-client thParams' clnt@Client {subscriptions, ntfSubscriptions, rcvQ, sndQ, sessionId} Server {subscribedQ, ntfSubscribedQ, notifiers} = do
+client :: Client -> Server -> M ()
+client clnt@Client {subscriptions, ntfSubscriptions, rcvQ, sndQ, sessionId} Server {subscribedQ, ntfSubscribedQ, notifiers} = do
  labelMyThread . B.unpack $ "client $" <> encode sessionId <> " commands"
-  forever $ do
-    (proxied, rs) <- partitionEithers . L.toList <$> (mapM processCommand =<< atomically (readTBQueue rcvQ))
-    forM_ (L.nonEmpty rs) reply
-    -- TODO cancel this thread if the client gets disconnected
-    -- TODO limit client concurrency
-    forM_ (L.nonEmpty proxied) $ \cmds -> forkIO $ mapConcurrently processProxiedCmd cmds >>= reply
+  forever $
+    atomically (readTBQueue rcvQ)
+      >>= mapM processCommand
+      >>= atomically . writeTBQueue sndQ
  where
-    reply :: MonadIO m => NonEmpty (Transmission BrokerMsg) -> m ()
-    reply = atomically . writeTBQueue sndQ
-    processProxiedCmd :: Transmission (Command 'ProxiedClient) -> M (Transmission BrokerMsg)
-    processProxiedCmd (corrId, sessId, command) = (corrId, sessId,) <$> case command of
-      PRXY srv auth -> ifM allowProxy getRelay (pure $ ERR AUTH)
-        where
-          allowProxy = do
-            ServerConfig {allowSMPProxy, newQueueBasicAuth} <- asks config
-            pure $ allowSMPProxy && maybe True ((== auth) . Just) newQueueBasicAuth
-          getRelay = do
-            ProxyAgent {smpAgent} <- asks proxyAgent
-            -- TODO catch IO errors too
-            liftIO $ proxyResp <$> runExceptT (getSMPServerClient' smpAgent srv)
-            where
-              proxyResp = \case
-                Right smp ->
-                  let THandleParams {sessionId = srvSessId, thAuth} = thParams smp
-                      vr = supportedServerSMPRelayVRange
-                   in case thAuth of
-                        Just THAuthClient {serverCertKey} -> PKEY srvSessId vr serverCertKey
-                        Nothing -> ERR $ PROXY TRANSPORT -- TODO different error?
-                Left err -> ERR $ smpProxyError err
-      PFWD pubKey encBlock -> do
-        ProxyAgent {smpAgent} <- asks proxyAgent
-        atomically (lookupSMPServerClient smpAgent sessId) >>= \case
-          Just smp -> liftIO $ either (ERR . smpProxyError) PRES <$> runExceptT (forwardSMPMessage smp corrId pubKey encBlock)
-          Nothing -> pure $ ERR $ PROXY NO_SESSION
-    processCommand :: (Maybe QueueRec, Transmission Cmd) -> M (Either (Transmission (Command 'ProxiedClient)) (Transmission BrokerMsg))
+    processCommand :: (Maybe QueueRec, Transmission Cmd) -> M (Transmission BrokerMsg)
    processCommand (qr_, (corrId, queueId, cmd)) = do
      st <- asks queueStore
      case cmd of
-        Cmd SProxiedClient command -> pure $ Left (corrId, queueId, command)
-        Cmd SSender command -> Right <$> case command of
-          SEND flags msgBody -> withQueue $ \qr -> sendMessage qr flags msgBody
-          PING -> pure (corrId, "", PONG)
-          RFWD encBlock -> (corrId, "",) <$> processForwardedCommand encBlock
-        Cmd SNotifier NSUB -> Right <$> subscribeNotifications
+        Cmd SSender command ->
+          case command of
+            SEND flags msgBody -> withQueue $ \qr -> sendMessage qr flags msgBody
+            PING -> pure (corrId, "", PONG)
+        Cmd SNotifier NSUB -> subscribeNotifications
        Cmd SRecipient command ->
-          Right <$> case command of
+          case command of
            NEW rKey dhKey auth subMode ->
              ifM
                allowNew
@@ -914,59 +893,6 @@ client thParams' clnt@Client {subscriptions, ntfSubscriptions, rcvQ, sndQ, sessi
                  encNMsgMeta = C.cbEncrypt rcvNtfDhSecret cbNonce (smpEncode msgMeta) 128
              pure . (cbNonce,) $ fromRight "" encNMsgMeta

-        processForwardedCommand :: EncFwdTransmission -> M BrokerMsg
-        processForwardedCommand (EncFwdTransmission s) = fmap (either id id) . runExceptT $ do
-          -- TODO error
-          THAuthServer {clientPeerPubKey, serverPrivKey} <- maybe (throwError $ ERR INTERNAL) pure thAuth
-          -- TODO compute during handshake?
-          let sessSecret = C.dh' clientPeerPubKey serverPrivKey
-              proxyNonce = C.cbNonce $ bs corrId
-          -- TODO error
-          s' <- liftEitherWith internalErr $ C.cbDecrypt sessSecret proxyNonce s
-          -- TODO error
-          FwdTransmission {fwdCorrId, fwdKey, fwdTransmission = EncTransmission et} <- liftEitherWith internalErr $ smpDecode s'
-          -- TODO error - this error is reported to proxy, as we failed to get to client's transmission
-          let clientSecret = C.dh' fwdKey serverPrivKey
-              clientNonce = C.cbNonce $ bs fwdCorrId
-          b <- liftEitherWith internalErr $ C.cbDecrypt clientSecret clientNonce et
-          -- only allowing single forwarded transactions
-          let t' = tDecodeParseValidate thParams' $ L.head $ tParse thParams' b
-              clntThAuth = Just $ THAuthServer {clientPeerPubKey = fwdKey, serverPrivKey}
-          -- TODO error
-          r <-
-            lift (rejectOrVerify clntThAuth t') >>= \case
-              Left r -> pure r
-              Right t''@(_, (corrId', entId', _)) ->
-                -- Left will not be returned by processCommand, as only SEND command is allowed
-                fromRight (corrId', entId', ERR INTERNAL) <$> lift (processCommand t'')
-
-          -- encode response
-          r' <- case batchTransmissions (batch thParams') (blockSize thParams') [Right (Nothing, encodeTransmission thParams' r)] of
-            [] -> throwE $ ERR INTERNAL -- TODO error
-            TBError _ _ : _ -> throwE $ ERR INTERNAL -- TODO error
-            TBTransmission b' _ : _ -> pure b'
-            TBTransmissions b' _ _ : _ -> pure b'
-          -- encrypt to client
-          r2 <- liftEitherWith internalErr $ EncResponse <$> C.cbEncrypt clientSecret (C.reverseNonce clientNonce) r' paddedProxiedMsgLength
-          -- encrypt to proxy
-          let fr = FwdResponse {fwdCorrId, fwdResponse = r2}
-          r3 <- liftEitherWith internalErr $ EncFwdResponse <$> C.cbEncrypt sessSecret (C.reverseNonce proxyNonce) (smpEncode fr) paddedForwardedMsgLength
-          pure $ RRES r3
-          where
-            internalErr _ = ERR INTERNAL -- TODO errors
-            THandleParams {thAuth} = thParams'
-            rejectOrVerify :: Maybe (THandleAuth 'TServer) -> SignedTransmission ErrorType Cmd -> M (Either (Transmission BrokerMsg) (Maybe QueueRec, Transmission Cmd))
-            rejectOrVerify clntThAuth (tAuth, authorized, (corrId', entId', cmdOrError)) =
-              case cmdOrError of
-                Left e -> pure $ Left (corrId', entId', ERR e)
-                -- flags msgBody -> withQueue $ \qr -> sendMessage qr flags msgBody
-                Right cmd'@(Cmd SSender SEND {}) -> verified <$> verifyTransmission ((,C.cbNonce (bs corrId')) <$> clntThAuth) tAuth authorized entId' cmd'
-                  where
-                    verified = \case
-                      VRVerified qr -> Right (qr, (corrId', entId', cmd'))
-                      VRFailed -> Left (corrId', entId', ERR AUTH)
-                Right _ -> pure $ Left (corrId', entId', ERR $ CMD PROHIBITED)
-
        deliverMessage :: T.Text -> QueueRec -> RecipientId -> TVar Sub -> MsgQueue -> Maybe Message -> M (Transmission BrokerMsg)
        deliverMessage name qr rId sub q msg_ = time (name <> " deliver") $ do
          readTVarIO sub >>= \case
@@ -1079,9 +1005,10 @@ saveServerMessages keepMsgs = asks (storeMsgsFile . config) >>= mapM_ saveMessag
            >>= mapM_ (B.hPutStrLn h . strEncode . MLRv3 rId)

 restoreServerMessages :: M Int
-restoreServerMessages = asks (storeMsgsFile . config) >>= \case
-  Just f -> ifM (doesFileExist f) (restoreMessages f) (pure 0)
-  Nothing -> pure 0
+restoreServerMessages =
+  asks (storeMsgsFile . config) >>= \case
+    Just f -> ifM (doesFileExist f) (restoreMessages f) (pure 0)
+    Nothing -> pure 0
  where
    restoreMessages f = do
      logInfo $ "restoring messages from file " <> T.pack f
@@ -22,7 +22,6 @@ import Network.Socket (ServiceName)
 import qualified Network.TLS as T
 import Numeric.Natural
 import Simplex.Messaging.Agent.Lock
-import Simplex.Messaging.Client.Agent (SMPClientAgent, SMPClientAgentConfig, newSMPClientAgent)
 import Simplex.Messaging.Crypto (KeyHash (..))
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Protocol
@@ -35,7 +34,7 @@ import Simplex.Messaging.Server.StoreLog
 import Simplex.Messaging.TMap (TMap)
 import qualified Simplex.Messaging.TMap as TM
 import Simplex.Messaging.Transport (ATransport, VersionRangeSMP, VersionSMP)
-import Simplex.Messaging.Transport.Server (SocketState, TransportServerConfig, loadFingerprint, loadTLSServerParams, newSocketState)
+import Simplex.Messaging.Transport.Server (SocketState, TransportServerConfig, alpn, loadFingerprint, loadTLSServerParams, newSocketState)
 import System.IO (IOMode (..))
 import System.Mem.Weak (Weak)
 import UnliftIO.STM
@@ -80,9 +79,7 @@ data ServerConfig = ServerConfig
    -- | TCP transport config
    transportConfig :: TransportServerConfig,
    -- | run listener on control port
-    controlPort :: Maybe ServiceName,
-    smpAgentCfg :: SMPClientAgentConfig,
-    allowSMPProxy :: Bool -- auth is the same with `newQueueBasicAuth`
+    controlPort :: Maybe ServiceName
  }

 defMsgExpirationDays :: Int64
@@ -113,9 +110,8 @@ data Env = Env
    tlsServerParams :: T.ServerParams,
    serverStats :: ServerStats,
    sockets :: SocketState,
-    clientSeq :: TVar ClientId,
-    clients :: TVar (IntMap Client),
-    proxyAgent :: ProxyAgent -- senders served on this proxy
+    clientSeq :: TVar Int,
+    clients :: TVar (IntMap Client)
  }

 data Server = Server
@@ -126,18 +122,13 @@ data Server = Server
    savingLock :: Lock
  }

-data ProxyAgent = ProxyAgent
-  { smpAgent :: SMPClientAgent
-  }
-
-type ClientId = Int
-
 data Client = Client
-  { clientId :: ClientId,
+  { clientId :: Int,
    subscriptions :: TMap RecipientId (TVar Sub),
    ntfSubscriptions :: TMap NotifierId (),
    rcvQ :: TBQueue (NonEmpty (Maybe QueueRec, Transmission Cmd)),
    sndQ :: TBQueue (NonEmpty (Transmission BrokerMsg)),
+    msgQ :: TBQueue (NonEmpty (Transmission BrokerMsg)),
    endThreads :: TVar (IntMap (Weak ThreadId)),
    endThreadSeq :: TVar Int,
    thVersion :: VersionSMP,
@@ -145,8 +136,7 @@ data Client = Client
    connected :: TVar Bool,
    createdAt :: SystemTime,
    rcvActiveAt :: TVar SystemTime,
-    sndActiveAt :: TVar SystemTime,
-    proxyClient_ :: TVar (Maybe C.DhSecretX25519) -- this client is actually an SMP proxy
+    sndActiveAt :: TVar SystemTime
  }

 data SubscriptionThread = NoSub | SubPending | SubThread (Weak ThreadId) | ProhibitSub
@@ -165,20 +155,20 @@ newServer = do
  savingLock <- createLock
  return Server {subscribedQ, subscribers, ntfSubscribedQ, notifiers, savingLock}

-newClient :: TVar ClientId -> Natural -> VersionSMP -> ByteString -> SystemTime -> STM Client
+newClient :: TVar Int -> Natural -> VersionSMP -> ByteString -> SystemTime -> STM Client
 newClient nextClientId qSize thVersion sessionId createdAt = do
  clientId <- stateTVar nextClientId $ \next -> (next, next + 1)
  subscriptions <- TM.empty
  ntfSubscriptions <- TM.empty
  rcvQ <- newTBQueue qSize
  sndQ <- newTBQueue qSize
+  msgQ <- newTBQueue qSize
  endThreads <- newTVar IM.empty
  endThreadSeq <- newTVar 0
  connected <- newTVar True
  rcvActiveAt <- newTVar createdAt
  sndActiveAt <- newTVar createdAt
-  proxyClient_ <- newTVar Nothing
-  return Client {clientId, subscriptions, ntfSubscriptions, rcvQ, sndQ, endThreads, endThreadSeq, thVersion, sessionId, connected, createdAt, rcvActiveAt, sndActiveAt, proxyClient_}
+  return Client {clientId, subscriptions, ntfSubscriptions, rcvQ, sndQ, msgQ, endThreads, endThreadSeq, thVersion, sessionId, connected, createdAt, rcvActiveAt, sndActiveAt}

 newSubscription :: SubscriptionThread -> STM Sub
 newSubscription subThread = do
@@ -186,21 +176,20 @@ newSubscription subThread = do
  return Sub {subThread, delivered}

 newEnv :: ServerConfig -> IO Env
-newEnv config@ServerConfig {caCertificateFile, certificateFile, privateKeyFile, storeLogFile, smpAgentCfg} = do
+newEnv config@ServerConfig {caCertificateFile, certificateFile, privateKeyFile, storeLogFile, transportConfig} = do
  server <- atomically newServer
  queueStore <- atomically newQueueStore
  msgStore <- atomically newMsgStore
  random <- liftIO C.newRandom
  storeLog <- restoreQueues queueStore `mapM` storeLogFile
-  tlsServerParams <- loadTLSServerParams caCertificateFile certificateFile privateKeyFile
+  tlsServerParams <- loadTLSServerParams caCertificateFile certificateFile privateKeyFile (alpn transportConfig)
  Fingerprint fp <- loadFingerprint caCertificateFile
  let serverIdentity = KeyHash fp
  serverStats <- atomically . newServerStats =<< getCurrentTime
  sockets <- atomically newSocketState
  clientSeq <- newTVarIO 0
  clients <- newTVarIO mempty
-  proxyAgent <- atomically $ newSMPProxyAgent smpAgentCfg random
-  return Env {config, server, serverIdentity, queueStore, msgStore, random, storeLog, tlsServerParams, serverStats, sockets, clientSeq, clients, proxyAgent}
+  return Env {config, server, serverIdentity, queueStore, msgStore, random, storeLog, tlsServerParams, serverStats, sockets, clientSeq, clients}
  where
    restoreQueues :: QueueStore -> FilePath -> IO (StoreLog 'WriteMode)
    restoreQueues QueueStore {queues, senders, notifiers} f = do
@@ -216,8 +205,3 @@ newEnv config@ServerConfig {caCertificateFile, certificateFile, privateKeyFile,
    addNotifier q = case notifier q of
      Nothing -> id
      Just NtfCreds {notifierId} -> M.insert notifierId (recipientId q)
-
-newSMPProxyAgent :: SMPClientAgentConfig -> TVar ChaChaDRG -> STM ProxyAgent
-newSMPProxyAgent smpAgentCfg random = do
-  smpAgent <- newSMPClientAgent smpAgentCfg random
-  pure ProxyAgent {smpAgent}
@@ -18,8 +18,6 @@ import qualified Data.Text as T
 import Data.Text.Encoding (encodeUtf8)
 import Network.Socket (HostName)
 import Options.Applicative
-import Simplex.Messaging.Client (ProtocolClientConfig (..))
-import Simplex.Messaging.Client.Agent (SMPClientAgentConfig (..), defaultSMPClientAgentConfig)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol (BasicAuth (..), ProtoServerWithAuth (ProtoServerWithAuth), pattern SMPServer)
@@ -27,11 +25,10 @@ import Simplex.Messaging.Server (runSMPServer)
 import Simplex.Messaging.Server.CLI
 import Simplex.Messaging.Server.Env.STM (ServerConfig (..), defMsgExpirationDays, defaultInactiveClientExpiration, defaultMessageExpiration)
 import Simplex.Messaging.Server.Expiration
-import Simplex.Messaging.Transport (simplexMQVersion, supportedServerSMPRelayVRange, batchCmdsSMPVersion, sendingProxySMPVersion)
+import Simplex.Messaging.Transport (simplexMQVersion, supportedSMPHandshakes, supportedServerSMPRelayVRange)
 import Simplex.Messaging.Transport.Client (TransportHost (..))
 import Simplex.Messaging.Transport.Server (TransportServerConfig (..), defaultTransportServerConfig)
 import Simplex.Messaging.Util (safeDecodeUtf8)
-import Simplex.Messaging.Version (mkVersionRange)
 import System.Directory (createDirectoryIfMissing, doesFileExist)
 import System.FilePath (combine)
 import System.IO (BufferMode (..), hSetBuffering, stderr, stdout)
@@ -214,11 +211,10 @@ smpServerCLI cfgPath logPath =
              smpServerVRange = supportedServerSMPRelayVRange,
              transportConfig =
                defaultTransportServerConfig
-                  { logTLSErrors = fromMaybe False $ iniOnOff "TRANSPORT" "log_tls_errors" ini
+                  { logTLSErrors = fromMaybe False $ iniOnOff "TRANSPORT" "log_tls_errors" ini,
+                    alpn = Just supportedSMPHandshakes
                  },
-              controlPort = either (const Nothing) (Just . T.unpack) $ lookupValue "TRANSPORT" "control_port" ini,
-              smpAgentCfg = defaultSMPClientAgentConfig {smpCfg = (smpCfg defaultSMPClientAgentConfig) {serverVRange = mkVersionRange batchCmdsSMPVersion sendingProxySMPVersion}},
-              allowSMPProxy = True -- TODO: "get from INI"
+              controlPort = either (const Nothing) (Just . T.unpack) $ lookupValue "TRANSPORT" "control_port" ini
            }

 data CliCommand
@@ -310,3 +306,4 @@ cliCommandP cfgPath logPath iniFile =
      pure InitOptions {enableStoreLog, logStats, signAlgorithm, ip, fqdn, password, scripted}
    parseBasicAuth :: ReadM ServerPassword
    parseBasicAuth = eitherReader $ fmap ServerPassword . strDecode . B.pack
+
@@ -8,6 +8,9 @@ module Simplex.Messaging.Server.QueueStore where
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol

+-- normalized/storage form
+-- can be split into per-party pieces
+-- id/public key form party index, dhsecrets can use dense storage or loaded on demand
 data QueueRec = QueueRec
  { recipientId :: !RecipientId,
    recipientKey :: !RcvPublicAuthKey,
@@ -24,6 +24,8 @@ where

 import Control.Monad
 import Data.Functor (($>))
+import Data.HashMap.Strict (HashMap)
+import qualified Data.HashMap.Strict as HM
 import Simplex.Messaging.Protocol
 import Simplex.Messaging.Server.QueueStore
 import Simplex.Messaging.TMap (TMap)
@@ -32,29 +34,37 @@ import Simplex.Messaging.Util (ifM, ($>>=))
 import UnliftIO.STM

 data QueueStore = QueueStore
-  { queues :: TMap RecipientId (TVar QueueRec),
-    senders :: TMap SenderId RecipientId,
-    notifiers :: TMap NotifierId RecipientId
+  { recipientKeys :: TVar (HashMap RecipientId RcvPublicAuthKey), -- O(1) index for const-time auth checks
+    senderKeys :: TVar (HashMap SenderId SndPublicAuthKey), -- O(1) index for const-time auth checks
+    notifierKeys :: TVar (HashMap NotifierId NtfPublicAuthKey), -- O(1) index for const-time auth checks
+    queues :: TMap RecipientId (TVar QueueRec), -- can be stored cold; and indexed with ints (using annotated keys below)
+    senders :: TMap SenderId RecipientId, -- not needed with annotated keys
+    notifiers :: TMap NotifierId RecipientId -- not needed with annotated keys
  }

 newQueueStore :: STM QueueStore
 newQueueStore = do
+  recipientKeys <- newTVar mempty
+  senderKeys <- newTVar mempty
+  notifierKeys <- newTVar mempty
  queues <- TM.empty
  senders <- TM.empty
  notifiers <- TM.empty
-  pure QueueStore {queues, senders, notifiers}
+  pure QueueStore {recipientKeys, senderKeys, notifierKeys, queues, senders, notifiers}

 addQueue :: QueueStore -> QueueRec -> STM (Either ErrorType ())
-addQueue QueueStore {queues, senders} q@QueueRec {recipientId = rId, senderId = sId} = do
+addQueue QueueStore {recipientKeys, senderKeys, queues, senders} q@QueueRec {recipientId = rId, recipientKey, senderId = sId, senderKey} = do
  ifM hasId (pure $ Left DUPLICATE_) $ do
    qVar <- newTVar q
    TM.insert rId qVar queues
+    modifyTVar' recipientKeys $ HM.insert rId recipientKey
    TM.insert sId rId senders
+    forM_ senderKey $ modifyTVar' senderKeys . HM.insert rId -- XXX: should not exist here yet, unless testing?
    pure $ Right ()
  where
    hasId = (||) <$> TM.member rId queues <*> TM.member sId senders

-getQueue :: DirectParty p => QueueStore -> SParty p -> QueueId -> STM (Either ErrorType QueueRec)
+getQueue :: QueueStore -> SParty p -> QueueId -> STM (Either ErrorType QueueRec)
 getQueue QueueStore {queues, senders, notifiers} party qId =
  toResult <$> (mapM readTVar =<< getVar)
  where
@@ -64,13 +74,14 @@ getQueue QueueStore {queues, senders, notifiers} party qId =
      SNotifier -> TM.lookup qId notifiers $>>= (`TM.lookup` queues)

 secureQueue :: QueueStore -> RecipientId -> SndPublicAuthKey -> STM (Either ErrorType QueueRec)
-secureQueue QueueStore {queues} rId sKey =
+secureQueue QueueStore {senderKeys, queues} rId sKey =
  withQueue rId queues $ \qVar ->
    readTVar qVar >>= \q -> case senderKey q of
      Just k -> pure $ if sKey == k then Just q else Nothing
-      _ ->
+      _ -> do
        let q' = q {senderKey = Just sKey}
-         in writeTVar qVar q' $> Just q'
+        modifyTVar' senderKeys $ HM.insert rId sKey
+        writeTVar qVar q' $> Just q'

 addQueueNotifier :: QueueStore -> RecipientId -> NtfCreds -> STM (Either ErrorType QueueRec)
 addQueueNotifier QueueStore {queues, notifiers} rId ntfCreds@NtfCreds {notifierId = nId} = do
@@ -33,15 +33,17 @@ module Simplex.Messaging.Transport
    VersionSMP,
    VersionRangeSMP,
    THandleSMP,
+    supportedSMPHandshakes,
    supportedClientSMPRelayVRange,
    supportedServerSMPRelayVRange,
+    legacyServerSMPRelayVRange,
    currentClientSMPRelayVersion,
+    legacyServerSMPRelayVersion,
    currentServerSMPRelayVersion,
    batchCmdsSMPVersion,
    basicAuthSMPVersion,
    subModeSMPVersion,
    authCmdsSMPVersion,
-    sendingProxySMPVersion,
    simplexMQVersion,
    smpBlockSize,
    TransportConfig (..),
@@ -79,7 +81,7 @@ module Simplex.Messaging.Transport
  )
 where

-import Control.Applicative ((<|>))
+import Control.Applicative (optional, (<|>))
 import Control.Monad (forM)
 import Control.Monad.Except
 import Control.Monad.Trans.Except (throwE)
@@ -115,11 +117,6 @@ import UnliftIO.STM

 -- * Transport parameters

-- min size it works with:
-- unsigned message: 16292 (paddedProxiedMsgLength = 16151, paddedForwardedMsgLength = 16239)
-- Ed448: 16406 (16384 + 22, fails with 21)
-- Ed25519: 16356
-- X25519: 16381
 smpBlockSize :: Int
 smpBlockSize = 16384

@@ -155,23 +152,29 @@ subModeSMPVersion = VersionSMP 6
 authCmdsSMPVersion :: VersionSMP
 authCmdsSMPVersion = VersionSMP 7

-sendingProxySMPVersion :: VersionSMP
-sendingProxySMPVersion = VersionSMP 8
-
 currentClientSMPRelayVersion :: VersionSMP
-currentClientSMPRelayVersion = VersionSMP 6
+currentClientSMPRelayVersion = VersionSMP 7
+
+legacyServerSMPRelayVersion :: VersionSMP
+legacyServerSMPRelayVersion = VersionSMP 6

 currentServerSMPRelayVersion :: VersionSMP
-currentServerSMPRelayVersion = VersionSMP 6
+currentServerSMPRelayVersion = VersionSMP 7

 -- minimal supported protocol version is 4
 -- TODO remove code that supports sending commands without batching
 supportedClientSMPRelayVRange :: VersionRangeSMP
 supportedClientSMPRelayVRange = mkVersionRange batchCmdsSMPVersion currentClientSMPRelayVersion

+legacyServerSMPRelayVRange :: VersionRangeSMP
+legacyServerSMPRelayVRange = mkVersionRange batchCmdsSMPVersion legacyServerSMPRelayVersion
+
 supportedServerSMPRelayVRange :: VersionRangeSMP
 supportedServerSMPRelayVRange = mkVersionRange batchCmdsSMPVersion currentServerSMPRelayVersion

+supportedSMPHandshakes :: [ALPN]
+supportedSMPHandshakes = ["smp/1"]
+
 simplexMQVersion :: String
 simplexMQVersion = showVersion SMQ.version

@@ -203,6 +206,9 @@ class Transport c where
  -- | tls-unique channel binding per RFC5929
  tlsUnique :: c -> SessionId

+  -- | ALPN value negotiated for the session
+  getSessionALPN :: c -> Maybe ALPN
+
  -- | Close connection
  closeConnection :: c -> IO ()

@@ -297,6 +303,7 @@ instance Transport TLS where
  getServerConnection = getTLS TServer
  getClientConnection = getTLS TClient
  getServerCerts = tlsServerCerts
+  getSessionALPN = tlsALPN
  tlsUnique = tlsUniq
  closeConnection tls = closeTLS $ tlsContext tls

@@ -345,14 +352,14 @@ data THandleParams v p = THandleParams

 data THandleAuth (p :: TransportPeer) where
  THAuthClient ::
-    { serverPeerPubKey :: C.PublicKeyX25519, -- used only in the client to combine with per-queue key
-      serverCertKey :: (X.CertificateChain, X.SignedExact X.PubKey), -- the key here is clientPrivKey signed with server certificate
-      clientPrivKey :: C.PrivateKeyX25519 -- used to combine with peer's per-queue key (currently only in the server)
+    { serverPeerPubKey :: C.PublicKeyX25519, -- used by the client to combine with client's private per-queue key
+      serverCertKey :: (X.CertificateChain, X.SignedExact X.PubKey), -- the key here is serverPeerPubKey signed with server certificate
+      sessSecret :: Maybe C.DhSecretX25519 -- session secret (will be used in SMP proxy only)
    } ->
    THandleAuth 'TClient
  THAuthServer ::
-    { clientPeerPubKey :: C.PublicKeyX25519, -- used only in the client to combine with per-queue key
-      serverPrivKey :: C.PrivateKeyX25519 -- used to combine with peer's per-queue key (currently only in the server)
+    { serverPrivKey :: C.PrivateKeyX25519, -- used by the server to combine with client's public per-queue key
+      sessSecret' :: Maybe C.DhSecretX25519 -- session secret (will be used in SMP proxy only)
    } ->
    THandleAuth 'TServer

@@ -363,7 +370,6 @@ data ServerHandshake = ServerHandshake
  { smpVersionRange :: VersionRangeSMP,
    sessionId :: SessionId,
    -- pub key to agree shared secrets for command authorization and entity ID encryption.
-    -- todo C.PublicKeyX25519
    authPubKey :: Maybe (X.CertificateChain, X.SignedExact X.PubKey)
  }

@@ -409,7 +415,7 @@ encodeAuthEncryptCmds v k
  | otherwise = ""

 authEncryptCmdsP :: VersionSMP -> Parser a -> Parser (Maybe a)
-authEncryptCmdsP v p = if v >= authCmdsSMPVersion then Just <$> p else pure Nothing
+authEncryptCmdsP v p = if v >= authCmdsSMPVersion then optional p else pure Nothing

 -- | Error of SMP encrypted transport over TCP.
 data TransportError
@@ -478,20 +484,21 @@ smpServerHandshake serverSignKey c (k, pk) kh smpVRange = do
  let th@THandle {params = THandleParams {sessionId}} = smpTHandle c
      sk = C.signX509 serverSignKey $ C.publicToX509 k
      certChain = getServerCerts c
-  sendHandshake th $ ServerHandshake {sessionId, smpVersionRange = smpVRange, authPubKey = Just (certChain, sk)}
+      smpVersionRange = maybe legacyServerSMPRelayVRange (const smpVRange) $ getSessionALPN c
+  sendHandshake th $ ServerHandshake {sessionId, smpVersionRange, authPubKey = Just (certChain, sk)}
  getHandshake th >>= \case
    ClientHandshake {smpVersion = v, keyHash, authPubKey = k'}
      | keyHash /= kh ->
          throwE $ TEHandshake IDENTITY
-      | v `isCompatible` smpVRange ->
+      | v `isCompatible` smpVersionRange ->
          pure $ smpThHandleServer th v pk k'
      | otherwise -> throwE $ TEHandshake VERSION

 -- | Client SMP transport handshake.
 --
 -- See https://github.com/simplex-chat/simplexmq/blob/master/protocol/simplex-messaging.md#appendix-a
-smpClientHandshake :: forall c. Transport c => c -> C.KeyPairX25519 -> C.KeyHash -> VersionRangeSMP -> ExceptT TransportError IO (THandleSMP c 'TClient)
-smpClientHandshake c (k, pk) keyHash@(C.KeyHash kh) smpVRange = do
+smpClientHandshake :: forall c. Transport c => c -> Maybe C.KeyPairX25519 -> C.KeyHash -> VersionRangeSMP -> ExceptT TransportError IO (THandleSMP c 'TClient)
+smpClientHandshake c ks_ keyHash@(C.KeyHash kh) smpVRange = do
  let th@THandle {params = THandleParams {sessionId}} = smpTHandle c
  ServerHandshake {sessionId = sessId, smpVersionRange, authPubKey} <- getHandshake th
  if sessionId /= sessId
@@ -506,18 +513,18 @@ smpClientHandshake c (k, pk) keyHash@(C.KeyHash kh) smpVRange = do
            serverKey <- getServerVerifyKey c
            pubKey <- C.verifyX509 serverKey exact
            (,certKey) <$> (C.x509ToPublic (pubKey, []) >>= C.pubKey)
-        sendHandshake th $ ClientHandshake {smpVersion = v, keyHash, authPubKey = Just k}
-        pure $ smpThHandleClient th v pk ck_
+        sendHandshake th $ ClientHandshake {smpVersion = v, keyHash, authPubKey = fst <$> ks_}
+        pure $ smpThHandleClient th v (snd <$> ks_) ck_
      Nothing -> throwE $ TEHandshake VERSION

 smpThHandleServer :: forall c. THandleSMP c 'TServer -> VersionSMP -> C.PrivateKeyX25519 -> Maybe C.PublicKeyX25519 -> THandleSMP c 'TServer
 smpThHandleServer th v pk k_ =
-  let thAuth = (\k -> THAuthServer {clientPeerPubKey = k, serverPrivKey = pk}) <$> k_
-   in smpThHandle_ th v thAuth
+  let thAuth = THAuthServer {serverPrivKey = pk, sessSecret' = (`C.dh'` pk) <$> k_}
+   in smpThHandle_ th v (Just thAuth)

-smpThHandleClient :: forall c. THandleSMP c 'TClient -> VersionSMP -> C.PrivateKeyX25519 -> Maybe (C.PublicKeyX25519, (X.CertificateChain, X.SignedExact X.PubKey)) -> THandleSMP c 'TClient
-smpThHandleClient th v pk ck_ =
-  let thAuth = (\(k, ck) -> THAuthClient {serverPeerPubKey = k, serverCertKey = ck, clientPrivKey = pk}) <$> ck_
+smpThHandleClient :: forall c. THandleSMP c 'TClient -> VersionSMP -> Maybe C.PrivateKeyX25519 -> Maybe (C.PublicKeyX25519, (X.CertificateChain, X.SignedExact X.PubKey)) -> THandleSMP c 'TClient
+smpThHandleClient th v pk_ ck_ =
+  let thAuth = (\(k, ck) -> THAuthClient {serverPeerPubKey = k, serverCertKey = ck, sessSecret = C.dh' k <$> pk_}) <$> ck_
   in smpThHandle_ th v thAuth

 smpThHandle_ :: forall c p. THandleSMP c p -> VersionSMP -> Maybe (THandleAuth p) -> THandleSMP c p
@@ -2,6 +2,7 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE NamedFieldPuns #-}
+{-# LANGUAGE NumericUnderscores #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE ScopedTypeVariables #-}

@@ -10,6 +11,7 @@ module Simplex.Messaging.Transport.Client
    runTLSTransportClient,
    smpClientHandshake,
    defaultSMPPort,
+    defaultTcpConnectTimeout,
    defaultTransportClientConfig,
    defaultSocksProxy,
    TransportClientConfig (..),
@@ -17,7 +19,7 @@ module Simplex.Messaging.Transport.Client
    TransportHost (..),
    TransportHosts (..),
    TransportHosts_ (..),
-    validateCertificateChain
+    validateCertificateChain,
  )
 where

@@ -50,7 +52,7 @@ import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Parsers (parseAll, parseString)
 import Simplex.Messaging.Transport
 import Simplex.Messaging.Transport.KeepAlive
-import Simplex.Messaging.Util (bshow, (<$?>), catchAll, tshow)
+import Simplex.Messaging.Util (bshow, catchAll, tshow, (<$?>))
 import System.IO.Error
 import Text.Read (readMaybe)
 import UnliftIO.Exception (IOException)
@@ -112,6 +114,7 @@ instance IsString (NonEmpty TransportHost) where fromString = parseString strDec

 data TransportClientConfig = TransportClientConfig
  { socksProxy :: Maybe SocksProxy,
+    tcpConnectTimeout :: Int,
    tcpKeepAlive :: Maybe KeepAliveOpts,
    logTLSErrors :: Bool,
    clientCredentials :: Maybe (X.CertificateChain, T.PrivKey),
@@ -119,8 +122,12 @@ data TransportClientConfig = TransportClientConfig
  }
  deriving (Eq, Show)

+-- time to resolve host, connect socket, set up TLS
+defaultTcpConnectTimeout :: Int
+defaultTcpConnectTimeout = 25_000_000
+
 defaultTransportClientConfig :: TransportClientConfig
-defaultTransportClientConfig = TransportClientConfig Nothing (Just defaultKeepAliveOpts) True Nothing Nothing
+defaultTransportClientConfig = TransportClientConfig Nothing defaultTcpConnectTimeout (Just defaultKeepAliveOpts) True Nothing Nothing

 clientTransportConfig :: TransportClientConfig -> TransportConfig
 clientTransportConfig TransportClientConfig {logTLSErrors} =
@@ -136,19 +143,21 @@ runTLSTransportClient tlsParams caStore_ cfg@TransportClientConfig {socksProxy,
  let hostName = B.unpack $ strEncode host
      clientParams = mkTLSClientParams tlsParams caStore_ hostName port keyHash clientCredentials alpn serverCert
      connectTCP = case socksProxy of
-        Just proxy -> connectSocksClient proxy proxyUsername $ hostAddr host
+        Just proxy -> connectSocksClient proxy proxyUsername (hostAddr host)
        _ -> connectTCPClient hostName
  c <- do
    sock <- connectTCP port
    mapM_ (setSocketKeepAlive sock) tcpKeepAlive `catchAll` \e -> logError ("Error setting TCP keep-alive" <> tshow e)
    let tCfg = clientTransportConfig cfg
-    connectTLS (Just hostName) tCfg clientParams sock >>= \tls -> do
-      chain <- atomically (tryTakeTMVar serverCert) >>= \case
+    -- No TLS timeout to avoid failing connections via SOCKS
+    tls <- connectTLS (Just hostName) tCfg clientParams sock
+    chain <-
+      atomically (tryTakeTMVar serverCert) >>= \case
        Nothing -> do
          logError "onServerCertificate didn't fire or failed to get cert chain"
          closeTLS tls >> error "onServerCertificate failed"
        Just c -> pure c
-      getClientConnection tCfg chain tls
+    getClientConnection tCfg chain tls
  client c `E.finally` closeConnection c
  where
    hostAddr = \case
@@ -24,7 +24,7 @@ import Numeric.Natural (Natural)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Transport (ALPN, SessionId, TLS (tlsALPN), getServerCerts, getServerVerifyKey, tlsUniq)
-import Simplex.Messaging.Transport.Client (TransportClientConfig (..), TransportHost (..), runTLSTransportClient)
+import Simplex.Messaging.Transport.Client (TransportClientConfig (..), TransportHost (..), defaultTcpConnectTimeout, runTLSTransportClient)
 import Simplex.Messaging.Transport.HTTP2
 import Simplex.Messaging.Util (eitherToMaybe)
 import UnliftIO.STM
@@ -70,8 +70,16 @@ defaultHTTP2ClientConfig :: HTTP2ClientConfig
 defaultHTTP2ClientConfig =
  HTTP2ClientConfig
    { qSize = 64,
-      connTimeout = 10000000,
-      transportConfig = TransportClientConfig Nothing Nothing True Nothing Nothing,
+      connTimeout = defaultTcpConnectTimeout,
+      transportConfig =
+        TransportClientConfig
+          { socksProxy = Nothing,
+            tcpConnectTimeout = defaultTcpConnectTimeout,
+            tcpKeepAlive = Nothing,
+            logTLSErrors = True,
+            clientCredentials = Nothing,
+            alpn = Nothing
+          },
      bufferSize = defaultHTTP2BufferSize,
      bodyHeadSize = 16384,
      suportedTLSParams = http2TLSParams
@@ -51,7 +51,7 @@ data HTTP2Server = HTTP2Server
 -- This server is for testing only, it processes all requests in a single queue.
 getHTTP2Server :: HTTP2ServerConfig -> IO HTTP2Server
 getHTTP2Server HTTP2ServerConfig {qSize, http2Port, bufferSize, bodyHeadSize, serverSupported, caCertificateFile, certificateFile, privateKeyFile, transportConfig} = do
-  tlsServerParams <- loadSupportedTLSServerParams serverSupported caCertificateFile certificateFile privateKeyFile
+  tlsServerParams <- loadSupportedTLSServerParams serverSupported caCertificateFile certificateFile privateKeyFile (alpn transportConfig)
  started <- newEmptyTMVarIO
  reqQ <- newTBQueueIO qSize
  action <- async $
@@ -28,10 +28,10 @@ import Control.Logger.Simple
 import Control.Monad
 import qualified Crypto.Store.X509 as SX
 import Data.Default (def)
-import Data.List (find)
 import Data.IntMap.Strict (IntMap)
 import qualified Data.IntMap.Strict as IM
-import Data.Maybe (fromJust)
+import Data.List (find)
+import Data.Maybe (fromJust, fromMaybe)
 import qualified Data.X509 as X
 import Data.X509.Validation (Fingerprint (..))
 import qualified Data.X509.Validation as XV
@@ -152,12 +152,13 @@ startTCPServer started port = withSocketsDo $ resolve >>= open >>= setStarted
      pure sock
    setStarted sock = atomically (tryPutTMVar started True) >> pure sock

-loadTLSServerParams :: FilePath -> FilePath -> FilePath -> IO T.ServerParams
+loadTLSServerParams :: FilePath -> FilePath -> FilePath -> Maybe [ALPN] -> IO T.ServerParams
 loadTLSServerParams = loadSupportedTLSServerParams supportedParameters

-loadSupportedTLSServerParams :: T.Supported -> FilePath -> FilePath -> FilePath -> IO T.ServerParams
-loadSupportedTLSServerParams serverSupported caCertificateFile certificateFile privateKeyFile =
-  fromCredential <$> loadServerCredential
+loadSupportedTLSServerParams :: T.Supported -> FilePath -> FilePath -> FilePath -> Maybe [ALPN] -> IO T.ServerParams
+loadSupportedTLSServerParams serverSupported caCertificateFile certificateFile privateKeyFile alpn_ = do
+  tlsServerParams <- fromCredential <$> loadServerCredential
+  pure tlsServerParams {T.serverHooks = maybe def alpnHooks alpn_}
  where
    loadServerCredential :: IO T.Credential
    loadServerCredential =
@@ -172,6 +173,7 @@ loadSupportedTLSServerParams serverSupported caCertificateFile certificateFile p
          T.serverHooks = def,
          T.serverSupported = serverSupported
        }
+    alpnHooks supported = def {T.onALPNClientSuggest = Just $ pure . fromMaybe "" . find (`elem` supported)}

 loadFingerprint :: FilePath -> IO Fingerprint
 loadFingerprint certificateFile = do
@@ -14,7 +14,8 @@ import Network.WebSockets
 import Network.WebSockets.Stream (Stream)
 import qualified Network.WebSockets.Stream as S
 import Simplex.Messaging.Transport
-  ( TProxy,
+  ( ALPN,
+    TProxy,
    Transport (..),
    TransportConfig (..),
    TransportError (..),
@@ -28,6 +29,7 @@ import Simplex.Messaging.Transport.Buffer (trimCR)
 data WS = WS
  { wsPeer :: TransportPeer,
    tlsUniq :: ByteString,
+    wsALPN :: Maybe ALPN,
    wsStream :: Stream,
    wsConnection :: Connection,
    wsTransportConfig :: TransportConfig,
@@ -61,6 +63,9 @@ instance Transport WS where
  getServerCerts :: WS -> X.CertificateChain
  getServerCerts = wsServerCerts

+  getSessionALPN :: WS -> Maybe ALPN
+  getSessionALPN = wsALPN
+
  tlsUnique :: WS -> ByteString
  tlsUnique = tlsUniq

@@ -90,7 +95,8 @@ getWS wsPeer cfg wsServerCerts cxt = withTlsUnique wsPeer cxt connectWS
    connectWS tlsUniq = do
      s <- makeTLSContextStream cxt
      wsConnection <- connectPeer wsPeer s
-      pure $ WS {wsPeer, tlsUniq, wsStream = s, wsConnection, wsTransportConfig = cfg, wsServerCerts}
+      wsALPN <- T.getNegotiatedProtocol cxt
+      pure $ WS {wsPeer, tlsUniq, wsALPN, wsStream = s, wsConnection, wsTransportConfig = cfg, wsServerCerts}
    connectPeer :: TransportPeer -> Stream -> IO Connection
    connectPeer TServer = acceptClientRequest
    connectPeer TClient = sendClientRequest
@@ -27,9 +27,9 @@ import GHC.Stack (withFrozenCallStack)
 import Network.HTTP.Types (urlEncode)
 import SMPAgentClient
 import SMPClient (testKeyHash, testPort, testPort2, testStoreLogFile, withSmpServer, withSmpServerStoreLogOn)
-import Simplex.Messaging.Agent.Protocol hiding (MID, CONF, INFO, REQ)
+import Simplex.Messaging.Agent.Protocol hiding (CONF, INFO, MID, REQ)
 import qualified Simplex.Messaging.Agent.Protocol as A
-import Simplex.Messaging.Crypto.Ratchet (InitialKeys (..), PQEncryption (..), PQSupport (..), pattern IKPQOn, pattern IKPQOff, pattern PQEncOn, pattern PQSupportOn, pattern PQSupportOff)
+import Simplex.Messaging.Crypto.Ratchet (InitialKeys (..), PQEncryption (..), PQSupport (..), pattern IKPQOff, pattern IKPQOn, pattern PQEncOn, pattern PQSupportOff, pattern PQSupportOn)
 import qualified Simplex.Messaging.Crypto.Ratchet as CR
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol (ErrorType (..))
@@ -214,14 +214,13 @@ testDuplexConnection _ alice bob = testDuplexConnection' (alice, IKPQOn) (bob, P
 testDuplexConnection' :: (HasCallStack, Transport c) => (c, InitialKeys) -> (c, PQSupport) -> IO ()
 testDuplexConnection' (alice, aPQ) (bob, bPQ) = do
  let pq = pqConnectionMode aPQ bPQ
-      pqSup = CR.pqEncToSupport pq
  ("1", "bob", Right (INV cReq)) <- alice #: ("1", "bob", "NEW T INV" <> pqConnModeStr aPQ <> " subscribe")
  let cReq' = strEncode cReq
  bob #: ("11", "alice", "JOIN T " <> cReq' <> enableKEMStr bPQ <> " subscribe 14\nbob's connInfo") #> ("11", "alice", OK)
  ("", "bob", Right (A.CONF confId pqSup' _ "bob's connInfo")) <- (alice <#:)
-  pqSup' `shouldBe` pqSup
+  pqSup' `shouldBe` CR.connPQEncryption aPQ
  alice #: ("2", "bob", "LET " <> confId <> " 16\nalice's connInfo") #> ("2", "bob", OK)
-  bob <# ("", "alice", A.INFO pqSup "alice's connInfo")
+  bob <# ("", "alice", A.INFO bPQ "alice's connInfo")
  bob <# ("", "alice", CON pq)
  alice <# ("", "bob", CON pq)
  -- message IDs 1 to 3 get assigned to control messages, so first MSG is assigned ID 4
@@ -253,15 +252,14 @@ testDuplexConnRandomIds _ alice bob = testDuplexConnRandomIds' (alice, IKPQOn) (
 testDuplexConnRandomIds' :: (HasCallStack, Transport c) => (c, InitialKeys) -> (c, PQSupport) -> IO ()
 testDuplexConnRandomIds' (alice, aPQ) (bob, bPQ) = do
  let pq = pqConnectionMode aPQ bPQ
-      pqSup = CR.pqEncToSupport pq
  ("1", bobConn, Right (INV cReq)) <- alice #: ("1", "", "NEW T INV" <> pqConnModeStr aPQ <> " subscribe")
  let cReq' = strEncode cReq
  ("11", aliceConn, Right OK) <- bob #: ("11", "", "JOIN T " <> cReq' <> enableKEMStr bPQ <> " subscribe 14\nbob's connInfo")
  ("", bobConn', Right (A.CONF confId pqSup' _ "bob's connInfo")) <- (alice <#:)
-  pqSup' `shouldBe` pqSup
+  pqSup' `shouldBe` CR.connPQEncryption aPQ
  bobConn' `shouldBe` bobConn
  alice #: ("2", bobConn, "LET " <> confId <> " 16\nalice's connInfo") =#> \case ("2", c, OK) -> c == bobConn; _ -> False
-  bob <# ("", aliceConn, A.INFO pqSup "alice's connInfo")
+  bob <# ("", aliceConn, A.INFO bPQ "alice's connInfo")
  bob <# ("", aliceConn, CON pq)
  alice <# ("", bobConn, CON pq)
  alice #: ("2", bobConn, "SEND F :hello") #> ("2", bobConn, A.MID 4 pq)
@@ -291,17 +289,15 @@ testContactConnection (alice, aPQ) (bob, bPQ) (tom, tPQ) = do
  ("1", "alice_contact", Right (INV cReq)) <- alice #: ("1", "alice_contact", "NEW T CON" <> pqConnModeStr aPQ <> " subscribe")
  let cReq' = strEncode cReq
      abPQ = pqConnectionMode aPQ bPQ
-      abPQSup = CR.pqEncToSupport abPQ
      aPQMode = CR.connPQEncryption aPQ

  bob #: ("11", "alice", "JOIN T " <> cReq' <> enableKEMStr bPQ <> " subscribe 14\nbob's connInfo") #> ("11", "alice", OK)
-  ("", "alice_contact", Right (A.REQ aInvId pqSup' _ "bob's connInfo")) <- (alice <#:)
-  pqSup' `shouldBe` bPQ
+  ("", "alice_contact", Right (A.REQ aInvId PQSupportOn _ "bob's connInfo")) <- (alice <#:)
  alice #: ("2", "bob", "ACPT " <> aInvId <> enableKEMStr aPQMode <> " 16\nalice's connInfo") #> ("2", "bob", OK)
  ("", "alice", Right (A.CONF bConfId pqSup'' _ "alice's connInfo")) <- (bob <#:)
-  pqSup'' `shouldBe` abPQSup
+  pqSup'' `shouldBe` bPQ
  bob #: ("12", "alice", "LET " <> bConfId <> " 16\nbob's connInfo 2") #> ("12", "alice", OK)
-  alice <# ("", "bob", A.INFO abPQSup "bob's connInfo 2")
+  alice <# ("", "bob", A.INFO (CR.connPQEncryption aPQ) "bob's connInfo 2")
  alice <# ("", "bob", CON abPQ)
  bob <# ("", "alice", CON abPQ)
  alice #: ("3", "bob", "SEND F :hi") #> ("3", "bob", A.MID 4 abPQ)
@@ -310,15 +306,13 @@ testContactConnection (alice, aPQ) (bob, bPQ) (tom, tPQ) = do
  bob #: ("13", "alice", "ACK 4") #> ("13", "alice", OK)

  let atPQ = pqConnectionMode aPQ tPQ
-      atPQSup = CR.pqEncToSupport atPQ
  tom #: ("21", "alice", "JOIN T " <> cReq' <> enableKEMStr tPQ <> " subscribe 14\ntom's connInfo") #> ("21", "alice", OK)
-  ("", "alice_contact", Right (A.REQ aInvId' pqSup3 _ "tom's connInfo")) <- (alice <#:)
-  pqSup3 `shouldBe` tPQ
+  ("", "alice_contact", Right (A.REQ aInvId' PQSupportOn _ "tom's connInfo")) <- (alice <#:)
  alice #: ("4", "tom", "ACPT " <> aInvId' <> enableKEMStr aPQMode <> " 16\nalice's connInfo") #> ("4", "tom", OK)
  ("", "alice", Right (A.CONF tConfId pqSup4 _ "alice's connInfo")) <- (tom <#:)
-  pqSup4 `shouldBe` atPQSup
+  pqSup4 `shouldBe` tPQ
  tom #: ("22", "alice", "LET " <> tConfId <> " 16\ntom's connInfo 2") #> ("22", "alice", OK)
-  alice <# ("", "tom", A.INFO atPQSup "tom's connInfo 2")
+  alice <# ("", "tom", A.INFO (CR.connPQEncryption aPQ) "tom's connInfo 2")
  alice <# ("", "tom", CON atPQ)
  tom <# ("", "alice", CON atPQ)
  alice #: ("5", "tom", "SEND F :hi there") #> ("5", "tom", A.MID 4 atPQ)
@@ -329,22 +323,20 @@ testContactConnection (alice, aPQ) (bob, bPQ) (tom, tPQ) = do
 testContactConnRandomIds :: Transport c => (c, InitialKeys) -> (c, PQSupport) -> IO ()
 testContactConnRandomIds (alice, aPQ) (bob, bPQ) = do
  let pq = pqConnectionMode aPQ bPQ
-      pqSup = CR.pqEncToSupport pq
  ("1", aliceContact, Right (INV cReq)) <- alice #: ("1", "", "NEW T CON" <> pqConnModeStr aPQ <> " subscribe")
  let cReq' = strEncode cReq

  ("11", aliceConn, Right OK) <- bob #: ("11", "", "JOIN T " <> cReq' <> enableKEMStr bPQ <> " subscribe 14\nbob's connInfo")
-  ("", aliceContact', Right (A.REQ aInvId pqSup' _ "bob's connInfo")) <- (alice <#:)
-  pqSup' `shouldBe` bPQ
+  ("", aliceContact', Right (A.REQ aInvId PQSupportOn _ "bob's connInfo")) <- (alice <#:)
  aliceContact' `shouldBe` aliceContact

  ("2", bobConn, Right OK) <- alice #: ("2", "", "ACPT " <> aInvId <> enableKEMStr (CR.connPQEncryption aPQ) <> " 16\nalice's connInfo")
  ("", aliceConn', Right (A.CONF bConfId pqSup'' _ "alice's connInfo")) <- (bob <#:)
-  pqSup'' `shouldBe` pqSup
+  pqSup'' `shouldBe` bPQ
  aliceConn' `shouldBe` aliceConn

  bob #: ("12", aliceConn, "LET " <> bConfId <> " 16\nbob's connInfo 2") #> ("12", aliceConn, OK)
-  alice <# ("", bobConn, A.INFO pqSup "bob's connInfo 2")
+  alice <# ("", bobConn, A.INFO (CR.connPQEncryption aPQ) "bob's connInfo 2")
  alice <# ("", bobConn, CON pq)
  bob <# ("", aliceConn, CON pq)

@@ -358,7 +350,7 @@ testRejectContactRequest _ alice bob = do
  ("1", "a_contact", Right (INV cReq)) <- alice #: ("1", "a_contact", "NEW T CON subscribe")
  let cReq' = strEncode cReq
  bob #: ("11", "alice", "JOIN T " <> cReq' <> " subscribe 10\nbob's info") #> ("11", "alice", OK)
-  ("", "a_contact", Right (A.REQ aInvId PQSupportOff _ "bob's info")) <- (alice <#:)
+  ("", "a_contact", Right (A.REQ aInvId PQSupportOn _ "bob's info")) <- (alice <#:)
  -- RJCT must use correct contact connection
  alice #: ("2a", "bob", "RJCT " <> aInvId) #> ("2a", "bob", ERR $ CONN NOT_FOUND)
  alice #: ("2b", "a_contact", "RJCT " <> aInvId) #> ("2b", "a_contact", OK)
@@ -555,10 +547,10 @@ testResumeDeliveryQuotaExceeded _ alice bob = do
  bob <#= \case ("", "alice", Msg "message 4") -> True; _ -> False
  bob #: ("4", "alice", "ACK 7") #> ("4", "alice", OK)
  inAnyOrder
-      (tGetAgent alice)
-      [ \case ("", c, Right (SENT 8)) -> c == "bob"; _ -> False,
-        \case ("", c, Right QCONT) -> c == "bob"; _ -> False
-      ]
+    (tGetAgent alice)
+    [ \case ("", c, Right (SENT 8)) -> c == "bob"; _ -> False,
+      \case ("", c, Right QCONT) -> c == "bob"; _ -> False
+    ]
  bob <#= \case ("", "alice", Msg "over quota") -> True; _ -> False
  -- message 8 is skipped because of alice agent sending "QCONT" message
  bob #: ("5", "alice", "ACK 9") #> ("5", "alice", OK)
@@ -571,12 +563,11 @@ connect' (h1, name1, pqMode1) (h2, name2, pqMode2) = do
  ("c1", _, Right (INV cReq)) <- h1 #: ("c1", name2, "NEW T INV" <> pqConnModeStr pqMode1 <> " subscribe")
  let cReq' = strEncode cReq
      pq = pqConnectionMode pqMode1 pqMode2
-      pqSup = CR.pqEncToSupport pq
  h2 #: ("c2", name1, "JOIN T " <> cReq' <> enableKEMStr pqMode2 <> " subscribe 5\ninfo2") #> ("c2", name1, OK)
  ("", _, Right (A.CONF connId pqSup' _ "info2")) <- (h1 <#:)
-  pqSup' `shouldBe` pqSup
+  pqSup' `shouldBe` CR.connPQEncryption pqMode1
  h1 #: ("c3", name2, "LET " <> connId <> " 5\ninfo1") #> ("c3", name2, OK)
-  h2 <# ("", name1, A.INFO pqSup "info1")
+  h2 <# ("", name1, A.INFO pqMode2 "info1")
  h2 <# ("", name1, CON pq)
  h1 <# ("", name2, CON pq)

@@ -589,7 +580,7 @@ enableKEMStr _ = ""

 pqConnModeStr :: InitialKeys -> ByteString
 pqConnModeStr (IKNoPQ PQSupportOff) = ""
-pqConnModeStr pq =  " " <> strEncode pq
+pqConnModeStr pq = " " <> strEncode pq

 sendMessage :: Transport c => (c, ConnId) -> (c, ConnId) -> ByteString -> IO ()
 sendMessage (h1, name1) (h2, name2) msg = do
@@ -68,7 +68,7 @@ testE2ERatchetParams :: RcvE2ERatchetParamsUri 'C.X448
 testE2ERatchetParams = E2ERatchetParamsUri (mkVersionRange (VersionE2E 1) (VersionE2E 1)) testDhPubKey testDhPubKey Nothing

 testE2ERatchetParams12 :: RcvE2ERatchetParamsUri 'C.X448
-testE2ERatchetParams12 = E2ERatchetParamsUri (supportedE2EEncryptVRange PQSupportOn) testDhPubKey testDhPubKey Nothing
+testE2ERatchetParams12 = E2ERatchetParamsUri supportedE2EEncryptVRange testDhPubKey testDhPubKey Nothing

 connectionRequest :: AConnectionRequestUri
 connectionRequest =
@@ -82,7 +82,7 @@ connectionRequestCurrentRange :: AConnectionRequestUri
 connectionRequestCurrentRange =
  ACR SCMInvitation $
    CRInvitationUri
-      connReqData {crAgentVRange = supportedSMPAgentVRange PQSupportOn, crSmpQueues = [queueV1, queueV1]}
+      connReqData {crAgentVRange = supportedSMPAgentVRange, crSmpQueues = [queueV1, queueV1]}
      testE2ERatchetParams12

 connectionRequestClientDataEmpty :: AConnectionRequestUri
@@ -93,9 +93,9 @@ fullMsgLen :: Ratchet a -> Int
 fullMsgLen Ratchet {rcSupportKEM, rcVersion} = headerLenLength + fullHeaderLen v rcSupportKEM + C.authTagSize + paddedMsgLen
  where
    v = current rcVersion
-    headerLenLength = case rcSupportKEM of
-      PQSupportOn | v >= pqRatchetE2EEncryptVersion -> 3 -- two bytes are added because of two Large used in new encoding
-      _ -> 1
+    headerLenLength
+      | v >= pqRatchetE2EEncryptVersion = 3 -- two bytes are added because of two Large used in new encoding
+      | otherwise = 1

 testMessageHeader :: forall a. AlgorithmI a => VersionE2E -> C.SAlgorithm a -> Expectation
 testMessageHeader v _ = do
@@ -520,7 +520,7 @@ initRatchets = do
  Right paramsBob <- pure $ pqX3dhSnd pkBob1 pkBob2 Nothing e2eAlice
  Right paramsAlice <- runExceptT $ pqX3dhRcv pkAlice1 pkAlice2 Nothing e2eBob
  (_, pkBob3) <- atomically $ C.generateKeyPair g
-  let vs = testRatchetVersions PQSupportOff
+  let vs = testRatchetVersions
      bob = initSndRatchet vs (C.publicKey pkAlice2) pkBob3 paramsBob
      alice = initRcvRatchet vs pkAlice2 paramsAlice PQSupportOff
  pure (alice, bob, encrypt' noSndKEM, decrypt' noRcvKEM, (\#>))
@@ -537,7 +537,7 @@ initRatchetsKEMProposed = do
  Right paramsBob <- pure $ pqX3dhSnd pkBob1 pkBob2 pKemParams_ e2eAlice
  Right paramsAlice <- runExceptT $ pqX3dhRcv pkAlice1 pkAlice2 Nothing e2eBob
  (_, pkBob3) <- atomically $ C.generateKeyPair g
-  let vs = testRatchetVersions PQSupportOn
+  let vs = testRatchetVersions
      bob = initSndRatchet vs (C.publicKey pkAlice2) pkBob3 paramsBob
      alice = initRcvRatchet vs pkAlice2 paramsAlice PQSupportOn
  pure (alice, bob, encrypt' hasSndKEM, decrypt' hasRcvKEM, (!#>))
@@ -555,7 +555,7 @@ initRatchetsKEMAccepted = do
  Right paramsBob <- pure $ pqX3dhSnd pkBob1 pkBob2 pKemParams_ e2eAlice
  Right paramsAlice <- runExceptT $ pqX3dhRcv pkAlice1 pkAlice2 pKem_ e2eBob
  (_, pkBob3) <- atomically $ C.generateKeyPair g
-  let vs = testRatchetVersions PQSupportOn
+  let vs = testRatchetVersions
      bob = initSndRatchet vs (C.publicKey pkAlice2) pkBob3 paramsBob
      alice = initRcvRatchet vs pkAlice2 paramsAlice PQSupportOn
  pure (alice, bob, encrypt' hasSndKEM, decrypt' hasRcvKEM, (!#>))
@@ -572,14 +572,14 @@ initRatchetsKEMProposedAgain = do
  Right paramsBob <- pure $ pqX3dhSnd pkBob1 pkBob2 pKemParams_ e2eAlice
  Right paramsAlice <- runExceptT $ pqX3dhRcv pkAlice1 pkAlice2 pKem_ e2eBob
  (_, pkBob3) <- atomically $ C.generateKeyPair g
-  let vs = testRatchetVersions PQSupportOn
+  let vs = testRatchetVersions
      bob = initSndRatchet vs (C.publicKey pkAlice2) pkBob3 paramsBob
      alice = initRcvRatchet vs pkAlice2 paramsAlice PQSupportOn
  pure (alice, bob, encrypt' hasSndKEM, decrypt' hasRcvKEM, (!#>))

-testRatchetVersions :: PQSupport -> RatchetVersions
-testRatchetVersions pq =
-  let v = maxVersion $ supportedE2EEncryptVRange pq
+testRatchetVersions :: RatchetVersions
+testRatchetVersions =
+  let v = maxVersion supportedE2EEncryptVRange
   in RatchetVersions v v

 encrypt_ :: AlgorithmI a => Maybe PQEncryption -> (TVar ChaChaDRG, Ratchet a, SkippedMsgKeys) -> ByteString -> IO (Either CryptoError (ByteString, Ratchet a, SkippedMsgDiff))
@@ -58,10 +58,10 @@ import Data.ByteString.Char8 (ByteString)
 import qualified Data.ByteString.Char8 as B
 import Data.Either (isRight)
 import Data.Int (Int64)
-import Data.List (nub)
+import Data.List (find, nub)
 import Data.List.NonEmpty (NonEmpty)
 import qualified Data.Map as M
-import Data.Maybe (isNothing)
+import Data.Maybe (isJust, isNothing)
 import qualified Data.Set as S
 import Data.Time.Clock (diffUTCTime, getCurrentTime)
 import Data.Time.Clock.System (SystemTime (..), getSystemTime)
@@ -80,7 +80,7 @@ import qualified Simplex.Messaging.Agent.Protocol as A
 import Simplex.Messaging.Agent.RetryInterval (RetryInterval (..))
 import Simplex.Messaging.Agent.Store.SQLite (MigrationConfirmation (..), SQLiteStore (dbNew))
 import Simplex.Messaging.Agent.Store.SQLite.Common (withTransaction')
-import Simplex.Messaging.Client (NetworkConfig (..), ProtocolClientConfig (..), TransportSessionMode (TSMEntity, TSMUser), defaultSMPClientConfig)
+import Simplex.Messaging.Client (NetworkConfig (..), ProtocolClientConfig (..), TransportSessionMode (TSMEntity, TSMUser), defaultClientConfig)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Crypto.Ratchet (InitialKeys (..), PQEncryption (..), PQSupport (..), pattern PQEncOff, pattern PQEncOn, pattern PQSupportOff, pattern PQSupportOn)
 import qualified Simplex.Messaging.Crypto.Ratchet as CR
@@ -90,7 +90,7 @@ import Simplex.Messaging.Protocol (BasicAuth, ErrorType (..), MsgBody, ProtocolS
 import qualified Simplex.Messaging.Protocol as SMP
 import Simplex.Messaging.Server.Env.STM (ServerConfig (..))
 import Simplex.Messaging.Server.Expiration
-import Simplex.Messaging.Transport (ATransport (..), SMPVersion, VersionSMP, authCmdsSMPVersion, basicAuthSMPVersion, batchCmdsSMPVersion, currentServerSMPRelayVersion)
+import Simplex.Messaging.Transport (ATransport (..), SMPVersion, VersionSMP, authCmdsSMPVersion, basicAuthSMPVersion, batchCmdsSMPVersion, currentServerSMPRelayVersion, supportedSMPHandshakes)
 import Simplex.Messaging.Util (diffToMicroseconds)
 import Simplex.Messaging.Version (VersionRange (..))
 import qualified Simplex.Messaging.Version as V
@@ -175,22 +175,26 @@ pattern Rcvd :: AgentMsgId -> ACommand 'Agent 'AEConn
 pattern Rcvd agentMsgId <- RCVD MsgMeta {integrity = MsgOk} [MsgReceipt {agentMsgId, msgRcptStatus = MROk}]

 smpCfgVPrev :: ProtocolClientConfig SMPVersion
-smpCfgVPrev = (smpCfg agentCfg) {serverVRange = prevRange $ serverVRange $ smpCfg agentCfg}
+smpCfgVPrev = (smpCfg agentCfg) {clientALPN = Nothing, serverVRange = prevRange $ serverVRange $ smpCfg agentCfg}

 smpCfgV7 :: ProtocolClientConfig SMPVersion
 smpCfgV7 = (smpCfg agentCfg) {serverVRange = V.mkVersionRange batchCmdsSMPVersion authCmdsSMPVersion}

+ntfCfgVPrev :: ProtocolClientConfig NTFVersion
+ntfCfgVPrev = (ntfCfg agentCfg) {clientALPN = Nothing, serverVRange = V.mkVersionRange (VersionNTF 1) (VersionNTF 1)}
+
 ntfCfgV2 :: ProtocolClientConfig NTFVersion
-ntfCfgV2 = (smpCfg agentCfg) {serverVRange = V.mkVersionRange (VersionNTF 1) authBatchCmdsNTFVersion}
+ntfCfgV2 = (ntfCfg agentCfg) {serverVRange = V.mkVersionRange (VersionNTF 1) authBatchCmdsNTFVersion}

 agentCfgVPrev :: AgentConfig
 agentCfgVPrev =
  agentCfg
    { sndAuthAlg = C.AuthAlg C.SEd25519,
-      smpAgentVRange = \_ -> prevRange $ smpAgentVRange agentCfg PQSupportOff,
+      smpAgentVRange = prevRange $ smpAgentVRange agentCfg,
      smpClientVRange = prevRange $ smpClientVRange agentCfg,
-      e2eEncryptVRange = \_ -> prevRange $ e2eEncryptVRange agentCfg PQSupportOff,
-      smpCfg = smpCfgVPrev
+      e2eEncryptVRange = prevRange $ e2eEncryptVRange agentCfg,
+      smpCfg = smpCfgVPrev,
+      ntfCfg = ntfCfgVPrev
    }

 -- agent config for the next client version
@@ -198,14 +202,14 @@ agentCfgV7 :: AgentConfig
 agentCfgV7 =
  agentCfg
    { sndAuthAlg = C.AuthAlg C.SX25519,
-      smpAgentVRange = \_ -> V.mkVersionRange duplexHandshakeSMPAgentVersion $ max pqdrSMPAgentVersion currentSMPAgentVersion,
-      e2eEncryptVRange = \_ -> V.mkVersionRange CR.kdfX3DHE2EEncryptVersion $ max CR.pqRatchetE2EEncryptVersion CR.currentE2EEncryptVersion,
+      smpAgentVRange = V.mkVersionRange duplexHandshakeSMPAgentVersion $ max pqdrSMPAgentVersion currentSMPAgentVersion,
+      e2eEncryptVRange = V.mkVersionRange CR.kdfX3DHE2EEncryptVersion $ max CR.pqRatchetE2EEncryptVersion CR.currentE2EEncryptVersion,
      smpCfg = smpCfgV7,
      ntfCfg = ntfCfgV2
    }

 agentCfgRatchetVPrev :: AgentConfig
-agentCfgRatchetVPrev = agentCfg {e2eEncryptVRange = \_ -> prevRange $ e2eEncryptVRange agentCfg PQSupportOff}
+agentCfgRatchetVPrev = agentCfg {e2eEncryptVRange = prevRange $ e2eEncryptVRange agentCfg}

 prevRange :: VersionRange v -> VersionRange v
 prevRange vr = vr {maxVersion = max (minVersion vr) (prevVersion $ maxVersion vr)}
@@ -244,7 +248,7 @@ createConnection :: AgentClient -> UserId -> Bool -> SConnectionMode c -> Maybe
 createConnection c userId enableNtfs cMode clientData = A.createConnection c userId enableNtfs cMode clientData (IKNoPQ PQSupportOn)

 joinConnection :: AgentClient -> UserId -> Bool -> ConnectionRequestUri c -> ConnInfo -> SubscriptionMode -> AE ConnId
-joinConnection c userId enableNtfs cReq connInfo = A.joinConnection c userId enableNtfs cReq connInfo PQSupportOn
+joinConnection c userId enableNtfs cReq connInfo = A.joinConnection c userId Nothing enableNtfs cReq connInfo PQSupportOn

 sendMessage :: AgentClient -> ConnId -> SMP.MsgFlags -> MsgBody -> AE AgentMsgId
 sendMessage c connId msgFlags msgBody = do
@@ -333,6 +337,9 @@ functionalAPITests t = do
    skip "faster version of the previous test (200 subscriptions gets very slow with test coverage)" $
      it "should subscribe to multiple (6) subscriptions with batching" $
        testBatchedSubscriptions 6 3 t
+    it "should subscribe to multiple connections with pending messages" $
+      withSmpServer t $
+        testBatchedPendingMessages 10 5
  describe "Async agent commands" $ do
    it "should connect using async agent commands" $
      withSmpServer t testAsyncCommands
@@ -503,7 +510,7 @@ runAgentClientTest :: HasCallStack => PQSupport -> AgentClient -> AgentClient ->
 runAgentClientTest pqSupport alice@AgentClient {} bob baseId =
  runRight_ $ do
    (bobId, qInfo) <- A.createConnection alice 1 True SCMInvitation Nothing (IKNoPQ pqSupport) SMSubscribe
-    aliceId <- A.joinConnection bob 1 True qInfo "bob's connInfo" pqSupport SMSubscribe
+    aliceId <- A.joinConnection bob 1 Nothing True qInfo "bob's connInfo" pqSupport SMSubscribe
    ("", _, A.CONF confId pqSup' _ "bob's connInfo") <- get alice
    liftIO $ pqSup' `shouldBe` pqSupport
    allowConnection alice bobId confId "alice's connInfo"
@@ -546,28 +553,27 @@ testEnablePQEncryption =
    (a, 4, "msg 1") \#>\ b
    (b, 5, "msg 2") \#>\ a
    -- 45 bytes is used by agent message envelope inside double ratchet message envelope
-    let largeMsg g' pqEnc = atomically $ C.randomBytes (e2eEncUserMsgLength pqdrSMPAgentVersion pqEnc - 45) g'
+    let largeMsg g' pqEnc = atomically $ C.randomBytes (e2eEncAgentMsgLength pqdrSMPAgentVersion pqEnc - 45) g'
    lrg <- largeMsg g PQSupportOff
    (a, 6, lrg) \#>\ b
    (b, 7, lrg) \#>\ a
-    -- enabling PQ encryption
-    (a, 8, lrg) \#>! b
-    (b, 9, lrg) \#>! a
    -- switched to smaller envelopes (before reporting PQ encryption enabled)
    sml <- largeMsg g PQSupportOn
    -- fail because of message size
    Left (A.CMD LARGE) <- tryError $ A.sendMessage ca bId PQEncOn SMP.noMsgFlags lrg
-    (11, PQEncOff) <- A.sendMessage ca bId PQEncOn SMP.noMsgFlags sml
-    get ca =##> \case ("", connId, SENT 11) -> connId == bId; _ -> False
-    get cb =##> \case ("", connId, MsgErr' 10 MsgSkipped {} PQEncOff msg') -> connId == aId && msg' == sml; _ -> False
-    ackMessage cb aId 10 Nothing
+    (9, PQEncOff) <- A.sendMessage ca bId PQEncOn SMP.noMsgFlags sml
+    get ca =##> \case ("", connId, SENT 9) -> connId == bId; _ -> False
+    get cb =##> \case ("", connId, MsgErr' 8 MsgSkipped {} PQEncOff msg') -> connId == aId && msg' == sml; _ -> False
+    ackMessage cb aId 8 Nothing
    -- -- fail in reply to sync IDss
    Left (A.CMD LARGE) <- tryError $ A.sendMessage cb aId PQEncOn SMP.noMsgFlags lrg
-    (12, PQEncOn) <- A.sendMessage cb aId PQEncOn SMP.noMsgFlags sml
-    get cb =##> \case ("", connId, SENT 12) -> connId == aId; _ -> False
-    get ca =##> \case ("", connId, MsgErr' 12 MsgSkipped {} PQEncOn msg') -> connId == bId && msg' == sml; _ -> False
-    ackMessage ca bId 12 Nothing
+    (10, PQEncOff) <- A.sendMessage cb aId PQEncOn SMP.noMsgFlags sml
+    get cb =##> \case ("", connId, SENT 10) -> connId == aId; _ -> False
+    get ca =##> \case ("", connId, MsgErr' 10 MsgSkipped {} PQEncOff msg') -> connId == bId && msg' == sml; _ -> False
+    ackMessage ca bId 10 Nothing
+    (a, 11, sml) \#>! b
    -- PQ encryption now enabled
+    (b, 12, sml) !#>! a
    (a, 13, sml) !#>! b
    (b, 14, sml) !#>! a
    -- disabling PQ encryption
@@ -631,7 +637,9 @@ runAgentClientContactTest :: HasCallStack => PQSupport -> AgentClient -> AgentCl
 runAgentClientContactTest pqSupport alice bob baseId =
  runRight_ $ do
    (_, qInfo) <- A.createConnection alice 1 True SCMContact Nothing (IKNoPQ pqSupport) SMSubscribe
-    aliceId <- A.joinConnection bob 1 True qInfo "bob's connInfo" pqSupport SMSubscribe
+    aliceId <- A.prepareConnectionToJoin bob 1 True qInfo pqSupport
+    aliceId' <- A.joinConnection bob 1 (Just aliceId) True qInfo "bob's connInfo" pqSupport SMSubscribe
+    liftIO $ aliceId' `shouldBe` aliceId
    ("", _, A.REQ invId pqSup' _ "bob's connInfo") <- get alice
    liftIO $ pqSup' `shouldBe` pqSupport
    bobId <- acceptContact alice True invId "alice's connInfo" PQSupportOn SMSubscribe
@@ -797,8 +805,8 @@ testAllowConnectionClientRestart t = do

 testIncreaseConnAgentVersion :: HasCallStack => ATransport -> IO ()
 testIncreaseConnAgentVersion t = do
-  alice <- getSMPAgentClient' 1 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 2} initAgentServers testDB
-  bob <- getSMPAgentClient' 2 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 2} initAgentServers testDB2
+  alice <- getSMPAgentClient' 1 agentCfg {smpAgentVRange = mkVersionRange 1 2} initAgentServers testDB
+  bob <- getSMPAgentClient' 2 agentCfg {smpAgentVRange = mkVersionRange 1 2} initAgentServers testDB2
  withSmpServerStoreMsgLogOn t testPort $ \_ -> do
    (aliceId, bobId) <- runRight $ do
      (aliceId, bobId) <- makeConnection_ PQSupportOff alice bob
@@ -810,7 +818,7 @@ testIncreaseConnAgentVersion t = do
    -- version doesn't increase if incompatible

    disposeAgentClient alice
-    alice2 <- getSMPAgentClient' 3 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 3} initAgentServers testDB
+    alice2 <- getSMPAgentClient' 3 agentCfg {smpAgentVRange = mkVersionRange 1 3} initAgentServers testDB

    runRight_ $ do
      subscribeConnection alice2 bobId
@@ -821,7 +829,7 @@ testIncreaseConnAgentVersion t = do
    -- version increases if compatible

    disposeAgentClient bob
-    bob2 <- getSMPAgentClient' 4 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 3} initAgentServers testDB2
+    bob2 <- getSMPAgentClient' 4 agentCfg {smpAgentVRange = mkVersionRange 1 3} initAgentServers testDB2

    runRight_ $ do
      subscribeConnection bob2 aliceId
@@ -832,7 +840,7 @@ testIncreaseConnAgentVersion t = do
    -- version doesn't decrease, even if incompatible

    disposeAgentClient alice2
-    alice3 <- getSMPAgentClient' 5 agentCfg {smpAgentVRange = \_ -> mkVersionRange 2 2} initAgentServers testDB
+    alice3 <- getSMPAgentClient' 5 agentCfg {smpAgentVRange = mkVersionRange 2 2} initAgentServers testDB

    runRight_ $ do
      subscribeConnection alice3 bobId
@@ -841,7 +849,7 @@ testIncreaseConnAgentVersion t = do
      checkVersion bob2 aliceId 3

    disposeAgentClient bob2
-    bob3 <- getSMPAgentClient' 6 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 1} initAgentServers testDB2
+    bob3 <- getSMPAgentClient' 6 agentCfg {smpAgentVRange = mkVersionRange 1 1} initAgentServers testDB2

    runRight_ $ do
      subscribeConnection bob3 aliceId
@@ -858,8 +866,8 @@ checkVersion c connId v = do

 testIncreaseConnAgentVersionMaxCompatible :: HasCallStack => ATransport -> IO ()
 testIncreaseConnAgentVersionMaxCompatible t = do
-  alice <- getSMPAgentClient' 1 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 2} initAgentServers testDB
-  bob <- getSMPAgentClient' 2 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 2} initAgentServers testDB2
+  alice <- getSMPAgentClient' 1 agentCfg {smpAgentVRange = mkVersionRange 1 2} initAgentServers testDB
+  bob <- getSMPAgentClient' 2 agentCfg {smpAgentVRange = mkVersionRange 1 2} initAgentServers testDB2
  withSmpServerStoreMsgLogOn t testPort $ \_ -> do
    (aliceId, bobId) <- runRight $ do
      (aliceId, bobId) <- makeConnection_ PQSupportOff alice bob
@@ -871,7 +879,7 @@ testIncreaseConnAgentVersionMaxCompatible t = do
    -- version increases to max compatible

    disposeAgentClient alice
-    alice2 <- getSMPAgentClient' 3 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 3} initAgentServers testDB
+    alice2 <- getSMPAgentClient' 3 agentCfg {smpAgentVRange = mkVersionRange 1 3} initAgentServers testDB
    disposeAgentClient bob
    bob2 <- getSMPAgentClient' 4 agentCfg {smpAgentVRange = supportedSMPAgentVRange} initAgentServers testDB2

@@ -886,8 +894,8 @@ testIncreaseConnAgentVersionMaxCompatible t = do

 testIncreaseConnAgentVersionStartDifferentVersion :: HasCallStack => ATransport -> IO ()
 testIncreaseConnAgentVersionStartDifferentVersion t = do
-  alice <- getSMPAgentClient' 1 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 2} initAgentServers testDB
-  bob <- getSMPAgentClient' 2 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 3} initAgentServers testDB2
+  alice <- getSMPAgentClient' 1 agentCfg {smpAgentVRange = mkVersionRange 1 2} initAgentServers testDB
+  bob <- getSMPAgentClient' 2 agentCfg {smpAgentVRange = mkVersionRange 1 3} initAgentServers testDB2
  withSmpServerStoreMsgLogOn t testPort $ \_ -> do
    (aliceId, bobId) <- runRight $ do
      (aliceId, bobId) <- makeConnection_ PQSupportOff alice bob
@@ -899,7 +907,7 @@ testIncreaseConnAgentVersionStartDifferentVersion t = do
    -- version increases to max compatible

    disposeAgentClient alice
-    alice2 <- getSMPAgentClient' 3 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 3} initAgentServers testDB
+    alice2 <- getSMPAgentClient' 3 agentCfg {smpAgentVRange = mkVersionRange 1 3} initAgentServers testDB

    runRight_ $ do
      subscribeConnection alice2 bobId
@@ -1400,7 +1408,9 @@ makeConnectionForUsers = makeConnectionForUsers_ PQSupportOn
 makeConnectionForUsers_ :: PQSupport -> AgentClient -> UserId -> AgentClient -> UserId -> ExceptT AgentErrorType IO (ConnId, ConnId)
 makeConnectionForUsers_ pqSupport alice aliceUserId bob bobUserId = do
  (bobId, qInfo) <- A.createConnection alice aliceUserId True SCMInvitation Nothing (CR.IKNoPQ pqSupport) SMSubscribe
-  aliceId <- A.joinConnection bob bobUserId True qInfo "bob's connInfo" pqSupport SMSubscribe
+  aliceId <- A.prepareConnectionToJoin bob bobUserId True qInfo pqSupport
+  aliceId' <- A.joinConnection bob bobUserId (Just aliceId) True qInfo "bob's connInfo" pqSupport SMSubscribe
+  liftIO $ aliceId' `shouldBe` aliceId
  ("", _, A.CONF confId pqSup' _ "bob's connInfo") <- get alice
  liftIO $ pqSup' `shouldBe` pqSupport
  allowConnection alice bobId confId "alice's connInfo"
@@ -1527,7 +1537,7 @@ testBatchedSubscriptions :: Int -> Int -> ATransport -> IO ()
 testBatchedSubscriptions nCreate nDel t =
  withAgentClientsCfgServers2 agentCfg agentCfg initAgentServers2 $ \a b -> do
    conns <- runServers $ do
-      conns <- replicateM (nCreate :: Int) $ makeConnection_ PQSupportOff a b
+      conns <- replicateM nCreate $ makeConnection_ PQSupportOff a b
      forM_ conns $ \(aId, bId) -> exchangeGreetings_ PQEncOff a bId b aId
      let (aIds', bIds') = unzip $ take nDel conns
      delete a bIds'
@@ -1586,6 +1596,25 @@ testBatchedSubscriptions nCreate nDel t =
        killThread t1
        pure res

+testBatchedPendingMessages :: Int -> Int -> IO ()
+testBatchedPendingMessages nCreate nMsgs =
+  withA $ \a -> do
+    conns <- withB $ \b -> runRight $ do
+      replicateM nCreate $ makeConnection a b
+    let msgConns = take nMsgs conns
+    runRight_ $ forM_ msgConns $ \(_, bId) -> sendMessage a bId SMP.noMsgFlags "hello"
+    replicateM_ nMsgs $ get a =##> \case ("", cId, SENT _) -> isJust $ find ((cId ==) . snd) msgConns; _ -> False
+    withB $ \b -> runRight_ $ do
+      r <- subscribeConnections b $ map fst conns
+      liftIO $ all isRight r `shouldBe` True
+      replicateM_ nMsgs $ do
+        ("", cId, Msg' msgId _ "hello") <- get b
+        liftIO $ isJust (find ((cId ==) . fst) msgConns) `shouldBe` True
+        ackMessage b cId msgId Nothing
+  where
+    withA = withAgent 1 agentCfg initAgentServers testDB
+    withB = withAgent 2 agentCfg initAgentServers testDB2
+
 testAsyncCommands :: IO ()
 testAsyncCommands =
  withAgentClients2 $ \alice bob -> runRight_ $ do
@@ -2413,7 +2442,8 @@ testCreateQueueAuth srvVersion clnt1 clnt2 = do
  where
    getClient clientId (clntAuth, clntVersion) db =
      let servers = initAgentServers {smp = userServers [ProtoServerWithAuth testSMPServer clntAuth]}
-          smpCfg = (defaultSMPClientConfig :: ProtocolClientConfig SMPVersion) {serverVRange = V.mkVersionRange (prevVersion basicAuthSMPVersion) clntVersion}
+          alpn_ = if clntVersion >= authCmdsSMPVersion then Just supportedSMPHandshakes else Nothing
+          smpCfg = defaultClientConfig alpn_ $ V.mkVersionRange (prevVersion basicAuthSMPVersion) clntVersion
          sndAuthAlg = if srvVersion >= authCmdsSMPVersion && clntVersion >= authCmdsSMPVersion then C.AuthAlg C.SX25519 else C.AuthAlg C.SEd25519
       in getSMPAgentClient' clientId agentCfg {smpCfg, sndAuthAlg} servers db

@@ -2454,8 +2484,8 @@ testDeliveryReceipts =

 testDeliveryReceiptsVersion :: HasCallStack => ATransport -> IO ()
 testDeliveryReceiptsVersion t = do
-  a <- getSMPAgentClient' 1 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 3} initAgentServers testDB
-  b <- getSMPAgentClient' 2 agentCfg {smpAgentVRange = \_ -> mkVersionRange 1 3} initAgentServers testDB2
+  a <- getSMPAgentClient' 1 agentCfg {smpAgentVRange = mkVersionRange 1 3} initAgentServers testDB
+  b <- getSMPAgentClient' 2 agentCfg {smpAgentVRange = mkVersionRange 1 3} initAgentServers testDB2
  withSmpServerStoreMsgLogOn t testPort $ \_ -> do
    (aId, bId) <- runRight $ do
      (aId, bId) <- makeConnection_ PQSupportOff a b
@@ -2482,8 +2512,8 @@ testDeliveryReceiptsVersion t = do
      subscribeConnection a' bId
      subscribeConnection b' aId
      exchangeGreetingsMsgId_ PQEncOff 6 a' bId b' aId
-      checkVersion a' bId 4
-      checkVersion b' aId 4
+      checkVersion a' bId 5
+      checkVersion b' aId 5
      (8, PQEncOff) <- A.sendMessage a' bId PQEncOn SMP.noMsgFlags "hello"
      get a' ##> ("", bId, SENT 8)
      get b' =##> \case ("", c, Msg' 8 PQEncOff "hello") -> c == aId; _ -> False
@@ -281,12 +281,12 @@ randomSUB_ :: (C.AlgorithmI a, C.AuthAlgorithm a) => C.SAlgorithm a -> VersionSM
 randomSUB_ a v sessId = do
  g <- C.newRandom
  rId <- atomically $ C.randomBytes 24 g
-  nonce@(C.CbNonce corrId) <- atomically $ C.randomCbNonce g
+  corrId <- atomically $ CorrId <$> C.randomBytes 24 g
  (rKey, rpKey) <- atomically $ C.generateAuthKeyPair a g
  thAuth_ <- testTHandleAuth v g rKey
  let thParams = testTHandleParams v sessId
-      TransmissionForAuth {tForAuth, tToSend} = encodeTransmissionForAuth thParams (CorrId corrId, rId, Cmd SRecipient SUB)
-  pure $ (,tToSend) <$> authTransmission thAuth_ (Just rpKey) nonce tForAuth
+      TransmissionForAuth {tForAuth, tToSend} = encodeTransmissionForAuth thParams (corrId, rId, Cmd SRecipient SUB)
+  pure $ (,tToSend) <$> authTransmission thAuth_ (Just rpKey) corrId tForAuth

 randomSUBCmd :: ProtocolClient SMPVersion ErrorType BrokerMsg -> IO (PCTransmission ErrorType BrokerMsg)
 randomSUBCmd = randomSUBCmd_ C.SEd25519
@@ -311,13 +311,13 @@ randomSEND_ :: (C.AlgorithmI a, C.AuthAlgorithm a) => C.SAlgorithm a -> VersionS
 randomSEND_ a v sessId len = do
  g <- C.newRandom
  sId <- atomically $ C.randomBytes 24 g
-  nonce@(C.CbNonce corrId) <- atomically $ C.randomCbNonce g
+  corrId <- atomically $ CorrId <$> C.randomBytes 3 g
  (sKey, spKey) <- atomically $ C.generateAuthKeyPair a g
  thAuth_ <- testTHandleAuth v g sKey
  msg <- atomically $ C.randomBytes len g
  let thParams = testTHandleParams v sessId
-      TransmissionForAuth {tForAuth, tToSend} = encodeTransmissionForAuth thParams (CorrId corrId, sId, Cmd SSender $ SEND noMsgFlags msg)
-  pure $ (,tToSend) <$> authTransmission thAuth_ (Just spKey) nonce tForAuth
+      TransmissionForAuth {tForAuth, tToSend} = encodeTransmissionForAuth thParams (corrId, sId, Cmd SSender $ SEND noMsgFlags msg)
+  pure $ (,tToSend) <$> authTransmission thAuth_ (Just spKey) corrId tForAuth

 testTHandleParams :: VersionSMP -> ByteString -> THandleParams SMPVersion 'TClient
 testTHandleParams v sessionId =
@@ -333,14 +333,13 @@ testTHandleParams v sessionId =
 testTHandleAuth :: VersionSMP -> TVar ChaChaDRG -> C.APublicAuthKey -> IO (Maybe (THandleAuth 'TClient))
 testTHandleAuth v g (C.APublicAuthKey a serverPeerPubKey) = case a of
  C.SX25519 | v >= authCmdsSMPVersion -> do
-    (_, clientPrivKey) <- atomically $ C.generateKeyPair @'C.X25519 g
    ca <- head <$> XS.readCertificates "tests/fixtures/ca.crt"
    serverCert <- head <$> XS.readCertificates "tests/fixtures/server.crt"
    serverKey <- head <$> XF.readKeyFile "tests/fixtures/server.key"
    signKey <- either error pure $ C.x509ToPrivate (serverKey, []) >>= C.privKey @C.APrivateSignKey
    (serverAuthPub, _) <- atomically $ C.generateKeyPair @'C.X25519 g
    let serverCertKey = (X.CertificateChain [serverCert, ca], C.signX509 signKey $ C.toPubKey C.publicToX509 serverAuthPub)
-    pure $ Just THAuthClient {serverPeerPubKey, serverCertKey, clientPrivKey}
+    pure $ Just THAuthClient {serverPeerPubKey, serverCertKey, sessSecret = Nothing}
  _ -> pure Nothing

 randomSENDCmd :: ProtocolClient SMPVersion ErrorType BrokerMsg -> Int -> IO (PCTransmission ErrorType BrokerMsg)
@@ -2,6 +2,7 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE StandaloneDeriving #-}
+{-# LANGUAGE TypeApplications #-}
 {-# OPTIONS_GHC -Wno-orphans #-}

 module CoreTests.ProtocolErrorTests where
@@ -13,10 +14,9 @@ import GHC.Generics (Generic)
 import Generic.Random (genericArbitraryU)
 import Simplex.FileTransfer.Transport (XFTPErrorType (..))
 import Simplex.Messaging.Agent.Protocol
-import qualified Simplex.Messaging.Agent.Protocol as Agent
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String
-import Simplex.Messaging.Protocol (CommandError (..), ErrorType (..), ProxyError (..))
+import Simplex.Messaging.Protocol (CommandError (..), ErrorType (..))
 import Simplex.Messaging.Transport (HandshakeError (..), TransportError (..))
 import Simplex.RemoteControl.Types (RCErrorType (..))
 import Test.Hspec
@@ -33,7 +33,7 @@ protocolErrorTests = modifyMaxSuccess (const 1000) $ do
        || strDecode (strEncode err) == Right err
  where
    errHasSpaces = \case
-      BROKER srv (Agent.RESPONSE e) -> hasSpaces srv || hasSpaces e
+      BROKER srv (RESPONSE e) -> hasSpaces srv || hasSpaces e
      BROKER srv _ -> hasSpaces srv
      _ -> False
    hasSpaces s = ' ' `B.elem` encodeUtf8 (T.pack s)
@@ -54,8 +54,6 @@ deriving instance Generic ErrorType

 deriving instance Generic CommandError

-deriving instance Generic ProxyError
-
 deriving instance Generic TransportError

 deriving instance Generic HandshakeError
@@ -80,8 +78,6 @@ instance Arbitrary ErrorType where arbitrary = genericArbitraryU

 instance Arbitrary CommandError where arbitrary = genericArbitraryU

-instance Arbitrary ProxyError where arbitrary = genericArbitraryU
-
 instance Arbitrary TransportError where arbitrary = genericArbitraryU

 instance Arbitrary HandshakeError where arbitrary = genericArbitraryU
@@ -22,10 +22,13 @@ tRcvQueuesTests = do
  describe "connection API" $ do
    it "hasConn" hasConnTest
    it "hasConn, batch add" hasConnTestBatch
+    it "hasConn, batch idempotent" batchIdempotentTest
    it "deleteConn" deleteConnTest
  describe "session API" $ do
    it "getSessQueues" getSessQueuesTest
    it "getDelSessQueues" getDelSessQueuesTest
+  describe "queue transfer" $ do
+    it "getDelSessQueues-batchAddQueues preserves total length" removeSubsTest

 checkDataInvariant :: RQ.TRcvQueues -> IO Bool
 checkDataInvariant trq = atomically $ do
@@ -62,6 +65,19 @@ hasConnTestBatch = do
  atomically (RQ.hasConn "c3" trq) `shouldReturn` True
  atomically (RQ.hasConn "nope" trq) `shouldReturn` False

+batchIdempotentTest :: IO ()
+batchIdempotentTest = do
+  trq <- atomically RQ.empty
+  let qs = [dummyRQ 0 "smp://1234-w==@alpha" "c1", dummyRQ 0 "smp://1234-w==@alpha" "c2", dummyRQ 0 "smp://1234-w==@beta" "c3"]
+  atomically $ RQ.batchAddQueues trq qs
+  checkDataInvariant trq `shouldReturn` True
+  qs' <- readTVarIO $ RQ.getRcvQueues trq
+  cs' <- readTVarIO $ RQ.getConnections trq
+  atomically $ RQ.batchAddQueues trq qs
+  checkDataInvariant trq `shouldReturn` True
+  readTVarIO (RQ.getRcvQueues trq) `shouldReturn` qs'
+  fmap L.nub <$> readTVarIO (RQ.getConnections trq) `shouldReturn`cs' -- connections get duplicated, but that doesn't appear to affect anybody
+
 deleteConnTest :: IO ()
 deleteConnTest = do
  trq <- atomically RQ.empty
@@ -121,6 +137,40 @@ getDelSessQueuesTest = do
  atomically (RQ.hasConn "c3" trq) `shouldReturn` True
  atomically (RQ.hasConn "c4" trq) `shouldReturn` True

+removeSubsTest :: IO ()
+removeSubsTest = do
+  aq <- atomically RQ.empty
+  let qs =
+        [ dummyRQ 0 "smp://1234-w==@alpha" "c1",
+          dummyRQ 0 "smp://1234-w==@alpha" "c2",
+          dummyRQ 0 "smp://1234-w==@beta" "c3",
+          dummyRQ 1 "smp://1234-w==@beta" "c4"
+        ]
+  atomically $ RQ.batchAddQueues aq qs
+
+  pq <- atomically RQ.empty
+  atomically (totalSize aq pq) `shouldReturn` (4, 4)
+
+  atomically $ RQ.getDelSessQueues (0, "smp://1234-w==@alpha", Nothing) aq >>= RQ.batchAddQueues pq . fst
+  atomically (totalSize aq pq) `shouldReturn` (4, 4)
+
+  atomically $ RQ.getDelSessQueues (0, "smp://1234-w==@beta", Just "non-existent") aq >>= RQ.batchAddQueues pq . fst
+  atomically (totalSize aq pq) `shouldReturn` (4, 4)
+
+  atomically $ RQ.getDelSessQueues (0, "smp://1234-w==@localhost", Nothing) aq >>= RQ.batchAddQueues pq . fst
+  atomically (totalSize aq pq) `shouldReturn` (4, 4)
+
+  atomically $ RQ.getDelSessQueues (0, "smp://1234-w==@beta", Just "c3") aq >>= RQ.batchAddQueues pq . fst
+  atomically (totalSize aq pq) `shouldReturn` (4, 4)
+
+totalSize :: RQ.TRcvQueues -> RQ.TRcvQueues -> STM (Int, Int)
+totalSize a b = do
+  qsizeA <- M.size <$> readTVar (RQ.getRcvQueues a)
+  qsizeB <- M.size <$> readTVar (RQ.getRcvQueues b)
+  csizeA <- M.size <$> readTVar (RQ.getConnections a)
+  csizeB <- M.size <$> readTVar (RQ.getConnections b)
+  pure (qsizeA + qsizeB, csizeA + csizeB)
+
 dummyRQ :: UserId -> SMPServer -> ConnId -> RcvQueue
 dummyRQ userId server connId =
  RcvQueue
@@ -36,6 +36,7 @@ import Simplex.Messaging.Encoding
 import Simplex.Messaging.Notifications.Protocol (NtfResponse)
 import Simplex.Messaging.Notifications.Server (runNtfServerBlocking)
 import Simplex.Messaging.Notifications.Server.Env
+import qualified Simplex.Messaging.Notifications.Server.Env as Env
 import Simplex.Messaging.Notifications.Server.Push.APNS
 import Simplex.Messaging.Notifications.Server.Push.APNS.Internal
 import Simplex.Messaging.Notifications.Transport
@@ -45,6 +46,7 @@ import Simplex.Messaging.Transport.Client
 import Simplex.Messaging.Transport.HTTP2 (HTTP2Body (..), http2TLSParams)
 import Simplex.Messaging.Transport.HTTP2.Server
 import Simplex.Messaging.Transport.Server
+import qualified Simplex.Messaging.Transport.Server as Server
 import Simplex.Messaging.Version (mkVersionRange)
 import Test.Hspec
 import UnliftIO.Async
@@ -73,10 +75,8 @@ ntfTestStoreLogFile = "tests/tmp/ntf-server-store.log"
 testNtfClient :: Transport c => (THandleNTF c 'TClient -> IO a) -> IO a
 testNtfClient client = do
  Right host <- pure $ chooseTransportHost defaultNetworkConfig testHost
-  runTransportClient defaultTransportClientConfig Nothing host ntfTestPort (Just testKeyHash) $ \h -> do
-    g <- C.newRandom
-    ks <- atomically $ C.generateKeyPair g
-    runExceptT (ntfClientHandshake h ks testKeyHash supportedClientNTFVRange) >>= \case
+  runTransportClient defaultTransportClientConfig Nothing host ntfTestPort (Just testKeyHash) $ \h ->
+    runExceptT (ntfClientHandshake h testKeyHash supportedClientNTFVRange) >>= \case
      Right th -> client th
      Left e -> error $ show e

@@ -115,7 +115,8 @@ ntfServerCfgV2 :: NtfServerConfig
 ntfServerCfgV2 =
  ntfServerCfg
    { ntfServerVRange = mkVersionRange initialNTFVersion authBatchCmdsNTFVersion,
-      smpAgentCfg = defaultSMPClientAgentConfig {smpCfg = (smpCfg defaultSMPClientAgentConfig) {serverVRange = mkVersionRange batchCmdsSMPVersion authCmdsSMPVersion}}
+      smpAgentCfg = defaultSMPClientAgentConfig {smpCfg = (smpCfg defaultSMPClientAgentConfig) {serverVRange = mkVersionRange batchCmdsSMPVersion authCmdsSMPVersion}},
+      Env.transportConfig = defaultTransportServerConfig {Server.alpn = Just supportedNTFHandshakes}
    }

 withNtfServerStoreLog :: ATransport -> (ThreadId -> IO a) -> IO a
@@ -34,7 +34,7 @@ import Simplex.Messaging.Agent.RetryInterval
 import Simplex.Messaging.Agent.Server (runSMPAgentBlocking)
 import Simplex.Messaging.Agent.Store.SQLite (MigrationConfirmation (..), SQLiteStore (dbNew))
 import Simplex.Messaging.Agent.Store.SQLite.Common (withTransaction')
-import Simplex.Messaging.Client (ProtocolClientConfig (..), chooseTransportHost, defaultSMPClientConfig, defaultNetworkConfig)
+import Simplex.Messaging.Client (ProtocolClientConfig (..), chooseTransportHost, defaultNetworkConfig, defaultSMPClientConfig)
 import Simplex.Messaging.Notifications.Client (defaultNTFClientConfig)
 import Simplex.Messaging.Parsers (parseAll)
 import Simplex.Messaging.Protocol (NtfServer, ProtoServerWithAuth)
@@ -215,7 +215,7 @@ agentCfg =
      certificateFile = "tests/fixtures/server.crt"
    }
  where
-    networkConfig = defaultNetworkConfig {tcpConnectTimeout = 3_000_000, tcpTimeout = 2_000_000}
+    networkConfig = defaultNetworkConfig {tcpConnectTimeout = 1_000_000, tcpTimeout = 2_000_000}

 fastRetryInterval :: RetryInterval
 fastRetryInterval = defaultReconnectInterval {initialInterval = 50_000}
@@ -16,8 +16,7 @@ import Control.Monad.Except (runExceptT)
 import Data.ByteString.Char8 (ByteString)
 import Data.List.NonEmpty (NonEmpty)
 import Network.Socket
-import Simplex.Messaging.Client (ProtocolClientConfig (..), chooseTransportHost, defaultNetworkConfig)
-import Simplex.Messaging.Client.Agent (SMPClientAgentConfig (..), defaultSMPClientAgentConfig)
+import Simplex.Messaging.Client (chooseTransportHost, defaultNetworkConfig)
 import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Protocol
@@ -25,8 +24,10 @@ import Simplex.Messaging.Server (runSMPServerBlocking)
 import Simplex.Messaging.Server.Env.STM
 import Simplex.Messaging.Transport
 import Simplex.Messaging.Transport.Client
+import qualified Simplex.Messaging.Transport.Client as Client
 import Simplex.Messaging.Transport.Server
-import Simplex.Messaging.Version (mkVersionRange)
+import qualified Simplex.Messaging.Transport.Server as Server
+import Simplex.Messaging.Version
 import System.Environment (lookupEnv)
 import System.Info (os)
 import Test.Hspec
@@ -74,16 +75,15 @@ testSMPClient = testSMPClientVR supportedClientSMPRelayVRange
 testSMPClientVR :: Transport c => VersionRangeSMP -> (THandleSMP c 'TClient -> IO a) -> IO a
 testSMPClientVR vr client = do
  Right useHost <- pure $ chooseTransportHost defaultNetworkConfig testHost
-  testSMPClient_ useHost testPort vr client
-
-testSMPClient_ :: Transport c => TransportHost -> ServiceName -> VersionRangeSMP -> (THandleSMP c 'TClient -> IO a) -> IO a
-testSMPClient_ host port vr client = do
-  runTransportClient defaultTransportClientConfig Nothing host port (Just testKeyHash) $ \h -> do
-    g <- C.newRandom
-    ks <- atomically $ C.generateKeyPair g
-    runExceptT (smpClientHandshake h ks testKeyHash vr) >>= \case
+  let tcConfig = defaultTransportClientConfig {Client.alpn = clientALPN}
+  runTransportClient tcConfig Nothing useHost testPort (Just testKeyHash) $ \h ->
+    runExceptT (smpClientHandshake h Nothing testKeyHash vr) >>= \case
      Right th -> client th
      Left e -> error $ show e
+  where
+    clientALPN
+      | authCmdsSMPVersion `isCompatible` vr = Just supportedSMPHandshakes
+      | otherwise = Nothing

 cfg :: ServerConfig
 cfg =
@@ -111,23 +111,13 @@ cfg =
      privateKeyFile = "tests/fixtures/server.key",
      certificateFile = "tests/fixtures/server.crt",
      smpServerVRange = supportedServerSMPRelayVRange,
-      transportConfig = defaultTransportServerConfig,
-      controlPort = Nothing,
-      smpAgentCfg = defaultSMPClientAgentConfig,
-      allowSMPProxy = False
+      transportConfig = defaultTransportServerConfig {Server.alpn = Just supportedSMPHandshakes},
+      controlPort = Nothing
    }

 cfgV7 :: ServerConfig
 cfgV7 = cfg {smpServerVRange = mkVersionRange batchCmdsSMPVersion authCmdsSMPVersion}

-proxyCfg :: ServerConfig
-proxyCfg =
-  cfgV7
-    { allowSMPProxy = True, 
-      smpServerVRange = mkVersionRange batchCmdsSMPVersion sendingProxySMPVersion,
-      smpAgentCfg = defaultSMPClientAgentConfig {smpCfg = (smpCfg defaultSMPClientAgentConfig) {serverVRange = mkVersionRange batchCmdsSMPVersion sendingProxySMPVersion}}
-    }
-
 withSmpServerStoreMsgLogOn :: HasCallStack => ATransport -> ServiceName -> (HasCallStack => ThreadId -> IO a) -> IO a
 withSmpServerStoreMsgLogOn t = withSmpServerConfigOn t cfg {storeLogFile = Just testStoreLogFile, storeMsgsFile = Just testStoreMsgsFile, serverStatsBackupFile = Just testServerStatsBackupFile}

@@ -1,137 +0,0 @@
-{-# LANGUAGE DataKinds #-}
-{-# LANGUAGE DuplicateRecordFields #-}
-{-# LANGUAGE GADTs #-}
-{-# LANGUAGE NamedFieldPuns #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-{-# LANGUAGE TupleSections #-}
-{-# LANGUAGE TypeApplications #-}
-
-module SMPProxyTests where
-
-import AgentTests.FunctionalAPITests (runRight_)
-import Data.ByteString.Char8 (ByteString)
-import SMPAgentClient (testSMPServer, testSMPServer2)
-import SMPClient
-import qualified SMPClient as SMP
-import ServerTests (decryptMsgV3, sendRecv)
-import Simplex.Messaging.Client
-import qualified Simplex.Messaging.Crypto as C
-import Simplex.Messaging.Protocol
-import Simplex.Messaging.Server.Env.STM (ServerConfig (..))
-import Simplex.Messaging.Transport
-import Simplex.Messaging.Version (mkVersionRange)
-import Test.Hspec
-import UnliftIO
-
-smpProxyTests :: Spec
-smpProxyTests = do
-  describe "server configuration" $ do
-    it "refuses proxy handshake unless enabled" testNoProxy
-    it "checks basic auth in proxy requests" testProxyAuth
-  describe "proxy requests" $ do
-    describe "bad relay URIs" $ do
-      xit "host not resolved" todo
-      xit "when SMP port blackholed" todo
-      xit "no SMP service at host/port" todo
-      xit "bad SMP fingerprint" todo
-    xit "batching proxy requests" todo
-  describe "forwarding requests" $ do
-    describe "deliver message via SMP proxy" $ do
-      it "same server" $
-        withSmpServerConfigOn (transport @TLS) proxyCfg testPort $ \_ -> do
-          let proxyServ = SMPServer SMP.testHost SMP.testPort SMP.testKeyHash
-          let relayServ = proxyServ
-          deliverMessageViaProxy proxyServ relayServ C.SEd448 "hello 1" "hello 2"
-      it "different servers" $
-        withSmpServerConfigOn (transport @TLS) proxyCfg testPort $ \_ ->
-          withSmpServerConfigOn (transport @TLS) cfgV7 testPort2 $ \_ -> do
-            let proxyServ = SMPServer SMP.testHost SMP.testPort SMP.testKeyHash
-            let relayServ = SMPServer SMP.testHost SMP.testPort2 SMP.testKeyHash
-            deliverMessageViaProxy proxyServ relayServ C.SEd448 "hello 1" "hello 2"
-      xit "max message size, Ed448 keys" $
-        withSmpServerConfigOn (transport @TLS) proxyCfg testPort $ \_ ->
-          withSmpServerConfigOn (transport @TLS) cfgV7 testPort2 $ \_ -> do
-            g <- C.newRandom
-            msg <- atomically $ C.randomBytes maxMessageLength g
-            msg' <- atomically $ C.randomBytes maxMessageLength g
-            let proxyServ = SMPServer SMP.testHost SMP.testPort SMP.testKeyHash
-            let relayServ = SMPServer SMP.testHost SMP.testPort2 SMP.testKeyHash
-            deliverMessageViaProxy proxyServ relayServ C.SEd448 msg msg'
-      it "max message size, Ed25519 keys" $
-        withSmpServerConfigOn (transport @TLS) proxyCfg testPort $ \_ ->
-          withSmpServerConfigOn (transport @TLS) cfgV7 testPort2 $ \_ -> do
-            g <- C.newRandom
-            msg <- atomically $ C.randomBytes maxMessageLength g
-            msg' <- atomically $ C.randomBytes maxMessageLength g
-            let proxyServ = SMPServer SMP.testHost SMP.testPort SMP.testKeyHash
-            let relayServ = SMPServer SMP.testHost SMP.testPort2 SMP.testKeyHash
-            deliverMessageViaProxy proxyServ relayServ C.SEd25519 msg msg'
-      it "max message size, X25519 keys" $
-        withSmpServerConfigOn (transport @TLS) proxyCfg testPort $ \_ ->
-          withSmpServerConfigOn (transport @TLS) cfgV7 testPort2 $ \_ -> do
-            g <- C.newRandom
-            msg <- atomically $ C.randomBytes maxMessageLength g
-            msg' <- atomically $ C.randomBytes maxMessageLength g
-            let proxyServ = SMPServer SMP.testHost SMP.testPort SMP.testKeyHash
-            let relayServ = SMPServer SMP.testHost SMP.testPort2 SMP.testKeyHash
-            deliverMessageViaProxy proxyServ relayServ C.SX25519 msg msg'
-    xit "sender-proxy-relay-recipient works" todo
-    xit "similar timing for proxied and direct sends" todo
-
-deliverMessageViaProxy :: (C.AlgorithmI a, C.AuthAlgorithm a) => SMPServer -> SMPServer -> C.SAlgorithm a -> ByteString -> ByteString -> IO ()
-deliverMessageViaProxy proxyServ relayServ alg msg msg' = do
-  g <- C.newRandom
-  -- set up proxy
-  Right pc <- getProtocolClient g (1, proxyServ, Nothing) defaultSMPClientConfig {serverVRange = mkVersionRange batchCmdsSMPVersion sendingProxySMPVersion} Nothing (\_ -> pure ())
-  THAuthClient {} <- maybe (fail "getProtocolClient returned no thAuth") pure $ thAuth $ thParams pc
-  -- set up relay
-  msgQ <- newTBQueueIO 4
-  Right rc <- getProtocolClient g (2, relayServ, Nothing) defaultSMPClientConfig {serverVRange = mkVersionRange batchCmdsSMPVersion authCmdsSMPVersion} (Just msgQ) (\_ -> pure ())
-  runRight_ $ do
-    -- prepare receiving queue
-    (rPub, rPriv) <- atomically $ C.generateAuthKeyPair alg g
-    (rdhPub, rdhPriv :: C.PrivateKeyX25519) <- atomically $ C.generateKeyPair g
-    QIK {rcvId, sndId, rcvPublicDhKey = srvDh} <- createSMPQueue rc (rPub, rPriv) rdhPub (Just "correct") SMSubscribe
-    let dec = decryptMsgV3 $ C.dh' srvDh rdhPriv
-    -- get proxy session
-    (sessId, v, relayKey) <- createSMPProxySession pc relayServ (Just "correct")
-    -- send via proxy to unsecured queue
-    proxySMPMessage pc sessId v relayKey Nothing sndId noMsgFlags msg
-    -- receive 1
-    (_tSess, _v, _sid, _ety, MSG RcvMessage {msgId, msgBody = EncRcvMsgBody encBody}) <- atomically $ readTBQueue msgQ
-    liftIO $ dec msgId encBody `shouldBe` Right msg
-    ackSMPMessage rc rPriv rcvId msgId
-    -- secure queue
-    (sPub, sPriv) <- atomically $ C.generateAuthKeyPair alg g
-    secureSMPQueue rc rPriv rcvId sPub
-    -- send via proxy to secured queue
-    proxySMPMessage pc sessId v relayKey (Just sPriv) sndId noMsgFlags msg'
-    -- receive 2
-    (_tSess, _v, _sid, _ety, MSG RcvMessage {msgId = msgId', msgBody = EncRcvMsgBody encBody'}) <- atomically $ readTBQueue msgQ
-    liftIO $ dec msgId' encBody' `shouldBe` Right msg'
-    ackSMPMessage rc rPriv rcvId msgId'
-
-proxyVRange :: VersionRangeSMP
-proxyVRange = mkVersionRange batchCmdsSMPVersion sendingProxySMPVersion
-
-testNoProxy :: IO ()
-testNoProxy = do
-  withSmpServerConfigOn (transport @TLS) cfg testPort2 $ \_ -> do
-    testSMPClient_ "127.0.0.1" testPort2 proxyVRange $ \(th :: THandleSMP TLS 'TClient) -> do
-      (_, _, (_corrId, _entityId, reply)) <- sendRecv th (Nothing, "0", "", PRXY testSMPServer Nothing)
-      reply `shouldBe` Right (ERR AUTH)
-
-testProxyAuth :: IO ()
-testProxyAuth = do
-  withSmpServerConfigOn (transport @TLS) proxyCfgAuth testPort $ \_ -> do
-    testSMPClient_ "127.0.0.1" testPort proxyVRange $ \(th :: THandleSMP TLS 'TClient) -> do
-      (_, _s, (_corrId, _entityId, reply)) <- sendRecv th (Nothing, "0", "", PRXY testSMPServer2 $ Just "wrong")
-      reply `shouldBe` Right (ERR AUTH)
-  where
-    proxyCfgAuth = proxyCfg {newQueueBasicAuth = Just "correct"}
-
-todo :: IO ()
-todo = do
-  fail "TODO"
@@ -62,7 +62,7 @@ serverTests t@(ATransport t') = do
  describe "Store log" $ testWithStoreLog t
  describe "Restore messages" $ testRestoreMessages t
  describe "Restore messages (old / v2)" $ testRestoreExpireMessages t
-  describe "Timing of AUTH error" $ testTiming t
+  fdescribe "Timing of AUTH error" $ testTiming t
  describe "Message notifications" $ testMessageNotifications t
  describe "Message expiration" $ do
    testMsgExpireOnSend t'
@@ -931,6 +931,8 @@ instance Eq C.ASignature where
    Just Refl -> s == s'
    _ -> False

+deriving instance Eq (C.Signature a)
+
 syntaxTests :: ATransport -> Spec
 syntaxTests (ATransport t) = do
  it "unknown command" $ ("", "abcd", "1234", ('H', 'E', 'L', 'L', 'O')) >#> ("", "abcd", "1234", ERR $ CMD UNKNOWN)
@@ -21,7 +21,6 @@ import GHC.IO.Exception (IOException (..))
 import qualified GHC.IO.Exception as IOException
 import NtfServerTests (ntfServerTests)
 import RemoteControl (remoteControlTests)
-import SMPProxyTests (smpProxyTests)
 import ServerTests
 import Simplex.Messaging.Transport (TLS, Transport (..))
 import Simplex.Messaging.Transport.WebSockets (WS)
@@ -47,7 +46,7 @@ main = do
      $ do
        describe "Agent SQLite schema dump" schemaDumpTest
        describe "Core tests" $ do
-          xdescribe "Batching tests" batchingTests
+          describe "Batching tests" batchingTests
          describe "Encoding tests" encodingTests
          describe "Protocol error tests" protocolErrorTests
          describe "Version range" versionRangeTests
@@ -60,7 +59,6 @@ main = do
        describe "SMP server via WebSockets" $ serverTests (transport @WS)
        describe "Notifications server" $ ntfServerTests (transport @TLS)
        describe "SMP client agent" $ agentTests (transport @TLS)
-        describe "SMP proxy" smpProxyTests
        describe "XFTP" $ do
          describe "XFTP server" xftpServerTests
          describe "XFTP file description" fileDescriptionTests
@@ -14,7 +14,6 @@ import Simplex.FileTransfer.Client
 import Simplex.FileTransfer.Description
 import Simplex.FileTransfer.Server (runXFTPServerBlocking)
 import Simplex.FileTransfer.Server.Env (XFTPServerConfig (..), defaultFileExpiration, defaultInactiveClientExpiration, supportedXFTPhandshakes)
-import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Protocol (XFTPServer)
 import Simplex.Messaging.Transport (ALPN)
 import Simplex.Messaging.Transport.Server
@@ -133,8 +132,7 @@ testXFTPClient :: HasCallStack => (HasCallStack => XFTPClient -> IO a) -> IO a
 testXFTPClient = testXFTPClientWith testXFTPClientConfig

 testXFTPClientWith :: HasCallStack => XFTPClientConfig -> (HasCallStack => XFTPClient -> IO a) -> IO a
-testXFTPClientWith cfg client = do
-  g <- C.newRandom
-  getXFTPClient g (1, testXFTPServer, Nothing) cfg (\_ -> pure ()) >>= \case
+testXFTPClientWith cfg client =
+  getXFTPClient (1, testXFTPServer, Nothing) cfg (\_ -> pure ()) >>= \case
    Right c -> client c
    Left e -> error $ show e
@@ -219,8 +219,7 @@ testFileChunkExpiration = withXFTPServerCfg testXFTPServerConfig {fileExpiration
 testInactiveClientExpiration :: Expectation
 testInactiveClientExpiration = withXFTPServerCfg testXFTPServerConfig {inactiveClientExpiration} $ \_ -> runRight_ $ do
  disconnected <- newEmptyTMVarIO
-  g <- liftIO C.newRandom
-  c <- ExceptT $ getXFTPClient g (1, testXFTPServer, Nothing) testXFTPClientConfig (\_ -> atomically $ putTMVar disconnected ())
+  c <- ExceptT $ getXFTPClient (1, testXFTPServer, Nothing) testXFTPClientConfig (\_ -> atomically $ putTMVar disconnected ())
  pingXFTP c
  liftIO $ do
    threadDelay 100000
Author	SHA1	Message	Date
Alexander Bondarenko	5aa2972774	WIP	2024-05-12 21:19:27 +03:00
Evgeny Poberezkin	1339a8da11	5.7.4.0	2024-05-11 23:39:28 +01:00
Evgeny Poberezkin	103ae06d55	agent: remove critical error on subscription timeout (#1146 )	2024-05-11 23:38:27 +01:00
Evgeny Poberezkin	acc7faea11	5.7.3.1	2024-05-10 22:24:00 +01:00
Evgeny PoberezkinandAlexander Bondarenko	727fd8b8f5	server: more efficient response to batched subscriptions (#1141 ) * server: more efficient response to batched subscriptions * add sndMsgQ for interleaving messages with replies * remove redundant liftIO * refactor * refactor2 * rename * fix * diff * remove comment * remove comment --------- Co-authored-by: Alexander Bondarenko <486682+dpwiz@users.noreply.github.com>	2024-05-10 22:19:11 +01:00
Evgeny Poberezkin	dc111437fd	5.7.3.0	2024-05-10 15:15:43 +01:00
Evgeny Poberezkin	5cafd9d5c4	server: more efficient responses to batch subscriptions (#1137 ) * server: more efficient responses to batch subscriptions * comments * comment * enable tests * LogError	2024-05-09 09:20:57 +01:00
Evgeny Poberezkin	ea21b296fd	agent: reset error count and do not report errors when consequitive timeouts happen while offline (#1136 ) * agent: reset error count and do not report errors when consequitive timeouts happen while offline * refactor * comment	2024-05-08 15:33:51 +01:00
spaced4ndy	3f57d54832	xftp: catch exceptions in chunk download (#1133 )	2024-05-08 16:57:04 +04:00
Evgeny Poberezkin	b40654c95d	update agent to v7/v2 SMP/NTF protocol versions (#997 ) * update agent to v7/v2 SMP/NTF protocol versions	2024-05-08 13:05:06 +01:00
Alexander BondarenkoandEvgeny Poberezkin	7a07076277	transport: require ALPN for extended handshakes (#1134 ) * transport: require ALPN for extended handshakes * fix 8.10 build * rename --------- Co-authored-by: Evgeny Poberezkin <evgeny@poberezkin.com>	2024-05-08 00:06:09 +01:00
Evgeny Poberezkin	93fd424f86	5.7.2.0	2024-05-05 17:13:26 +01:00
Evgeny Poberezkin	e13b0df539	client: remove TLS handshake timeout (#1129 ) * client: remove TLS handshake timeout * remove comment	2024-05-05 17:05:51 +01:00
Evgeny Poberezkin	ee8e4067b0	agent: prepare connection record before joining to prevent race conditions (#1128 ) * agent: prepare connection record before joining to prevent race conditions * prepare connection for contact address as well * clean up	2024-05-05 12:12:19 +01:00
Alexander BondarenkoandEvgeny Poberezkin	0e205e70ad	add TRcvQueues tests (#1117 ) Co-authored-by: Evgeny Poberezkin <evgeny@poberezkin.com>	2024-05-03 23:39:00 +01:00
Evgeny Poberezkin	b586a6e90a	client: removed concurrency limit when waiting for subscription results (#1126 )	2024-05-03 22:16:52 +01:00
Evgeny Poberezkin	259f6fcc3b	Merge branch 'stable'	2024-05-02 16:24:32 +01:00
Evgeny Poberezkin	8d8010a62a	5.7.1.0	2024-05-02 16:22:55 +01:00
Evgeny Poberezkin	c5941b790b	client: increase timeout for SOCKS connection, increase timeout for direct connection (#1123 )	2024-05-02 16:00:58 +01:00
Evgeny Poberezkin	60403955c0	5.7.0.4	2024-05-02 16:00:35 +01:00
Evgeny Poberezkinandspaced4ndy	9e49c289b4	upgrade SMP/NTF servers to v7/v2 protocol versions (#996 ) * upgrade SMP/NTF servers to v7/v2 protocol versions * 5.6.0.0 --------- Co-authored-by: spaced4ndy <8711996+spaced4ndy@users.noreply.github.com>	2024-05-02 16:00:03 +01:00
Evgeny Poberezkin	6f83273318	client: increase timeout for SOCKS connection, increase timeout for direct connection (#1123 )	2024-05-02 15:14:01 +01:00
Alexander BondarenkoandEvgeny Poberezkin	0d2c1d3c01	transport: reduce ping traffic (#1118 ) * transport: reduce ping traffic * make pings opt-in, enable automatically with SUB commands * fix reduced delays * enable pings on MSG too * rename pingErrorCount * check timeout counter even when not sending pings * clean up * reset timeout error count on any event --------- Co-authored-by: Evgeny Poberezkin <evgeny@poberezkin.com>	2024-05-01 10:38:33 +01:00
Evgeny Poberezkin	323cdc412e	5.7.0.4	2024-05-01 00:56:33 +01:00
Evgeny Poberezkinandspaced4ndy	66eccbecb3	upgrade SMP/NTF servers to v7/v2 protocol versions (#996 ) * upgrade SMP/NTF servers to v7/v2 protocol versions * 5.6.0.0 --------- Co-authored-by: spaced4ndy <8711996+spaced4ndy@users.noreply.github.com>	2024-05-01 00:51:08 +01:00
Evgeny Poberezkin	935d2e25df	5.7.0.3	2024-04-25 10:22:18 +01:00
Alexander Bondarenko	b931c1be37	utils: remove zstd contexts (#1116 )	2024-04-25 09:33:22 +01:00
Evgeny Poberezkin	daa866f333	5.7.0.2	2024-04-22 18:59:33 +01:00
Evgeny Poberezkin	fe28e02be7	agent: make version independent of PQ enqryption support (#1114 ) * agent: make version independent of PQ enqryption support * remove comment	2024-04-22 13:40:24 +01:00
Evgeny Poberezkin	1612a7e2c7	agent: reduce sizes for per-queue e2e encryption (#1113 )	2024-04-22 09:25:03 +01:00
Evgeny Poberezkin	b08314722d	5.7.0.1	2024-04-21 22:58:15 +01:00
Evgeny Poberezkin	2347b82b47	adjust timeouts and delayed response errors (#1112 )	2024-04-21 22:57:07 +01:00
Evgeny Poberezkin	3d40393ae8	5.7.0.0	2024-04-20 18:20:18 +01:00
Alexander BondarenkoandEvgeny Poberezkin	b98fdb672d	transport: increase client timeouts, don't send command after timeout (#1110 ) * transport: fix client handshake timeouts * fix handshake timeout * skip sending requests for timed out responses * expose batch concurrency as PClient field * move to NetworkConfig * remove Request on timeout * use record --------- Co-authored-by: Evgeny Poberezkin <evgeny@poberezkin.com>	2024-04-20 18:17:48 +01:00
Evgeny Poberezkin	3ba3172aaf	xftp: enable ALPN in XFTP server (#1109 )	2024-04-20 09:15:33 +01:00
Evgeny Poberezkin	c00c223f3b	remove (or make optional) client key from handshakes (#1104 ) * remove (or make optional) client key from handshakes * remove comment	2024-04-18 22:43:49 +01:00
Evgeny Poberezkin Alexander Bondarenko IC Rainbow	2f43b43225	parameterize transport handle with transport peer to include server certificate (#1100 ) * parameterize transport handle with transport peer to include server certificate * include server certificate into THandle * load server chain and sign key * fix key type * fix for 8.10 --------- Co-authored-by: Alexander Bondarenko <486682+dpwiz@users.noreply.github.com> Co-authored-by: IC Rainbow <aenor.realm@gmail.com>	2024-04-17 17:46:22 +01:00