smp-server: support namespaces (#1784)

* smp-server: namespaces resolver scaffolding

* smp-server: Names resolver hardening + cleanup

* smp-server: fuse parallel dispatchers

* smp-server: JSON wire format for NameRecord + Names.hs restructure

* smp-server: redact RpcAuth in Show

* smp-server: JSON wire fixups + spec rewrite + small cleanups

* plan: prepend implementation-diverged banner

* move SimplexName into shared module

* smp-server: name + contract whitelist on RSLV

* smp-server: address audit findings (canonical JSON, INI guards, SSRF, TLD case, shutdown)

* smp-server: round 2 audit fixes (label case, response cap, ipv6 link-local)

* smp-server: round 3 audit fixes (SSRF coverage, drop noop closeManager, CSV order)

* smp-server: round 4 audit fixes (0X-hex host, expanded IPv6 forms, pingEndpoint timeout)

* smp-server: hardcode TldRegistries (drop registry_tld_* INI keys)

* smp-server: round 6 audit fixes (IPv6 SSRF, redirects, ASCII labels)

- Reject IPv6 aliases of 169.254.169.254 (IPv4-compatible / IPv4-mapped /
  6to4 / NAT64) via numeric range check on parsed IPv6.
- Disable HTTP redirects on the Eth RPC request.
- Restrict SimplexName labels to ASCII (Cyrillic/Greek/full-width otherwise
  hash to different on-chain records and diverge from UTS-46 registrars).
- pingEndpoint: only JsonRpcErr means "reachable"; transport/decode failures
  fail startup. boundedIniInt: readMaybe over partial read.
- Add 127.0.0.0/8 and 0.0.0.0 to isLoopback.
- Replace hand-rolled hex helpers with Data.ByteArray.Encoding; raise
  managerConnCount to match rpcMaxConcurrency; hex Show for NameOwner.
- Fuse parallel http/https when into unless+case; drop reverse/re-reverse
  in mkDomain TLDWeb; first AbiInvariantViolated; Nothing <$ decodeAddress;
  forM_ (eitherToMaybe ...); >>= chain in NameOwner FromJSON.
- Drop dead imports/exports/pragmas and two restating comments.
- Tests: factor unsafeOwner/unsafeLink, addr1/2/3, testNamesConfig; add
  non-ASCII label rejection coverage.

* namespace: bound parser input to 253 bytes (DoS defense)

The bare-name fallback and bareDomain parser would otherwise consume
arbitrarily many non-space bytes via takeWhile1 before any validation
or length check. A crafted multi-megabyte token would be decoded as
UTF-8 and re-parsed in full before being rejected.

Introduce `boundedNonSpace` (scan with 253-byte cap) at the two
takeWhile1 sites. Inputs longer than 253 bytes leave residue that
parseOnly's implicit endOfInput rejects, so the parser fails fast
without ever allocating the full input.

The bound is the DNS full-domain limit, chosen for being a familiar
ceiling generous enough to cover any realistic SimpleX name (longest
plausible @user.subdomain.simplex stays well under 100 bytes). No
per-label cap — SimpleX names don't go through DNS label resolution
and there's no semantic reason to constrain individual labels.

* namespace: switch to Python HTTP resolver + agent plumbing (#1796)

* namespace: relax resolver_endpoint validation (path prefix, http without auth)

validateUrl gains two operator-friendly relaxations and a regression test:

- Allow a path prefix (e.g. https://gw.example.com:443/snrc) for a resolver
  behind a reverse-proxy sub-path; /resolve/<name> and /health are appended
  (HttpResolver already strips one trailing slash, so root and sub-path
  behave identically). Query/fragment/userinfo stay rejected.

- Off-loopback, reject only http WITH resolver_auth (the Authorization header
  would travel in cleartext). http without auth is now allowed (no secret to
  leak; resolver data is public — also lets dev setups reach a host resolver
  via http://host.docker.internal). https is always allowed, with or without
  auth. Plain http has no response integrity; intended for trusted/local
  networks only.

Exports validateUrl and adds validateUrlSpec (11 cases) to SMPNamesTests.

* namespace: NameRecord links as arrays (multi-link, cap 5)

* namespace: distinct RSLV error responses

RSLV collapsed every non-hit (no resolver, malformed name, not found,
backing-store failure) to ERR AUTH, so a client iterating its configured
servers could not tell "this router has no resolver, try the next" from
"name not registered, stop", and a transient backend error read as an
authoritative miss.

Names capability is runtime config, orthogonal to the linear SMP version
(a future v21 router without [NAMES] must still advertise v21), so it is
signalled by a command-time error like allowSMPProxy, not by the version
range:

  no resolver configured -> ERR CMD PROHIBITED  (client skips, tries next)
  backing-store failure   -> ERR INTERNAL        (transient: retry/surface)
  not found / malformed   -> ERR AUTH            (authoritative "no such name")

Update the protocol spec error table and add agent tests for the
no-resolver (CMD PROHIBITED) and backend-failure (INTERNAL) paths.

* refactor(names): server role + one error type

Addresses epoberezkin's review (PR #1784). Name resolution becomes a
server role like proxy; the agent owns resolution + server selection;
one error type flows through the whole stack.

- ServerRoles gains `names`; UserServers gains `nameSrvs` (opt-in list);
  resolveSimplexName drops the explicit server arg and picks a
  names-capable server via getNextServer.
- RSLV carries SimplexNameDomain (was RslvRequest): no JSON on the wire,
  contract dropped, name validated at parse (invalid -> CMD SYNTAX).
- Version check moves from the encoder to Client.hs (no ERR to server).
- ErrorType.NAME {nameErr :: NameErrorType} (+ AgentErrorType.NAME),
  wire- and JSON-encoded; resolver errors surface with diagnostics.
  Success response renamed NAME -> RNAME to free the collision.
- NameOwner -> EthAddress (record selector); NameRecord derives FromJSON
  and gains field-ordered Encoding; per-field caps removed.
- Remove newEnvWithNames / runSMPServerBlockingWithNames test seams;
  stub resolver folded into ServerConfig.namesResolverCall_.

* test(server): update stats backup line count

NameResolverStatsData adds 6 lines to the server stats backup (the
"rslvStats:" header plus the reqs/succ/notFound/resolverErrs/disabled
fields), so testRestoreMessages' expected stats-backup line count is
95 -> 101.

* feat(names): public-namespace resolution via RSLV/RNAME

SNRC names resolver role: RSLV command -> HTTP resolver -> RNAME record.
Agent owns server selection (ServerRoles.names); NAME error family; async,
concurrency-bounded resolution; length-prefixed extensible wire; spec.

* remove comments

Co-authored-by: Evgeny <evgeny@poberezkin.com>

* simplify

* move tests name

* simplify: text addresses, Tail JSON, drop admitRslv

* fix

* remove spaghetti

* reduce diff

* async again, refactor

* different threads limit for name resolutions

* remove comment

* FromField instance for SimplexNameInfo

* remove comments

* unStrJSON

* add sameConnShortLink

* remove scheme prefix

* remove unused import

* remove connecttarget tests

* remove comment

* comment

---------

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

src/Simplex/Messaging/Server.hs

@@ -65,7 +65,7 @@ import Data.Constraint (Dict (..))
 import Data.Dynamic (toDyn)
 import Data.Either (fromRight, partitionEithers)
 import Data.Foldable (foldrM)
-import Data.Functor (($>))
+import Data.Functor (($>), (<&>))
 import Data.IORef
 import Data.Int (Int64)
 import qualified Data.IntMap.Strict as IM
@@ -103,11 +103,13 @@ import qualified Simplex.Messaging.Crypto as C
 import Simplex.Messaging.Encoding
 import Simplex.Messaging.Encoding.String
 import Simplex.Messaging.Protocol
+import Simplex.Messaging.SimplexName (SimplexNameDomain)
 import Simplex.Messaging.Server.Control
 import Simplex.Messaging.Server.Env.STM as Env
 import Simplex.Messaging.Server.Expiration
 import Simplex.Messaging.Server.MsgStore
 import Simplex.Messaging.Server.MsgStore.Journal (JournalMsgStore, JournalQueue (..), getJournalQueueMessages)
+import Simplex.Messaging.Server.Names (NamesEnv, closeNamesEnv, resolveName)
 import Simplex.Messaging.Server.MsgStore.STM
 import Simplex.Messaging.Server.MsgStore.Types
 import Simplex.Messaging.Server.NtfStore
@@ -245,7 +247,9 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg, startOpt
       saveServerStats
 
     closeServer :: M s ()
-    closeServer = asks (smpAgent . proxyAgent) >>= liftIO . closeSMPClientAgent
+    closeServer = do
+      asks (smpAgent . proxyAgent) >>= liftIO . closeSMPClientAgent
+      asks namesEnv >>= liftIO . mapM_ closeNamesEnv
 
     serverThread ::
       forall sub. String ->
@@ -517,7 +521,7 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg, startOpt
       initialDelay <- (startAt -) . fromIntegral . (`div` 1000000_000000) . diffTimeToPicoseconds . utctDayTime <$> liftIO getCurrentTime
       liftIO $ putStrLn $ "server stats log enabled: " <> statsFilePath
       liftIO $ threadDelay' $ 1000000 * (initialDelay + if initialDelay < 0 then 86400 else 0)
-      ss@ServerStats {fromTime, qCreated, qSecured, qDeletedAll, qDeletedAllB, qDeletedNew, qDeletedSecured, qSub, qSubAllB, qSubAuth, qSubDuplicate, qSubProhibited, qSubEnd, qSubEndB, ntfCreated, ntfDeleted, ntfDeletedB, ntfSub, ntfSubB, ntfSubAuth, ntfSubDuplicate, msgSent, msgSentAuth, msgSentQuota, msgSentLarge, msgRecv, msgRecvGet, msgGet, msgGetNoMsg, msgGetAuth, msgGetDuplicate, msgGetProhibited, msgExpired, activeQueues, msgSentNtf, msgRecvNtf, activeQueuesNtf, qCount, msgCount, ntfCount, pRelays, pRelaysOwn, pMsgFwds, pMsgFwdsOwn, pMsgFwdsRecv, rcvServices, ntfServices}
+      ss@ServerStats {fromTime, qCreated, qSecured, qDeletedAll, qDeletedAllB, qDeletedNew, qDeletedSecured, qSub, qSubAllB, qSubAuth, qSubDuplicate, qSubProhibited, qSubEnd, qSubEndB, ntfCreated, ntfDeleted, ntfDeletedB, ntfSub, ntfSubB, ntfSubAuth, ntfSubDuplicate, msgSent, msgSentAuth, msgSentQuota, msgSentLarge, msgRecv, msgRecvGet, msgGet, msgGetNoMsg, msgGetAuth, msgGetDuplicate, msgGetProhibited, msgExpired, activeQueues, msgSentNtf, msgRecvNtf, activeQueuesNtf, qCount, msgCount, ntfCount, pRelays, pRelaysOwn, pMsgFwds, pMsgFwdsOwn, pMsgFwdsRecv, rcvServices, ntfServices, rslvStats}
         <- asks serverStats
       st <- asks msgStore
       EntityCounts {queueCount, notifierCount, rcvServiceCount, ntfServiceCount, rcvServiceQueuesCount, ntfServiceQueuesCount} <-
@@ -580,6 +584,7 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg, startOpt
           qCount' <- readIORef qCount
           msgCount' <- readIORef msgCount
           ntfCount' <- readIORef ntfCount
+          rslvStats' <- getResetNameResolverStatsData rslvStats
           T.hPutStrLn h $
             T.intercalate
               ","
@@ -653,6 +658,7 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg, startOpt
                      ]
                        <> showServiceStats rcvServices'
                        <> showServiceStats ntfServices'
+                       <> showNameResolverStats rslvStats'
               )
         liftIO $ threadDelay' interval
       where
@@ -660,6 +666,8 @@ smpServer started cfg@ServerConfig {transports, transportConfig = tCfg, startOpt
           map tshow [_pRequests, _pSuccesses, _pErrorsConnect, _pErrorsCompat, _pErrorsOther]
         showServiceStats ServiceStatsData {_srvAssocNew, _srvAssocDuplicate, _srvAssocUpdated, _srvAssocRemoved, _srvSubCount, _srvSubDuplicate, _srvSubQueues, _srvSubEnd} =
           map tshow [_srvAssocNew, _srvAssocDuplicate, _srvAssocUpdated, _srvAssocRemoved, _srvSubCount, _srvSubDuplicate, _srvSubQueues, _srvSubEnd]
+        showNameResolverStats NameResolverStatsData {_rslvReqs, _rslvSucc, _rslvNotFound, _rslvResolverErrs, _rslvDisabled} =
+          map tshow [_rslvReqs, _rslvSucc, _rslvNotFound, _rslvResolverErrs, _rslvDisabled]
 
     prometheusMetricsThread_ :: ServerConfig s -> [M s ()]
     prometheusMetricsThread_ ServerConfig {prometheusInterval = Just interval, prometheusMetricsFile} =
@@ -1266,6 +1274,7 @@ verifyQueueTransmission service thAuth (tAuth, authorized, (corrId, entId, comma
     vc SNotifierService NSUBS {} = verifyServiceCmd
     vc SProxiedClient _ = VRVerified Nothing
     vc SProxyService (RFWD _) = VRVerified Nothing
+    vc SResolver (RSLV _) = VRVerified Nothing
     checkRole = case (service, partyClientRole p) of
       (Just THClientService {serviceRole}, Just role) -> serviceRole == role
       _ -> True
@@ -1463,19 +1472,40 @@ client
           Nothing -> inc False pRequests >> inc False pErrorsConnect $> Just (ERR $ PROXY NO_SESSION)
       where
         forkProxiedCmd :: M s BrokerMsg -> M s (Maybe BrokerMsg)
-        forkProxiedCmd cmdAction = do
-          bracket_ wait signal . forkClient clnt (B.unpack $ "client $" <> encode sessionId <> " proxy") $ do
-            -- commands MUST be processed under a reasonable timeout or the client would halt
-            cmdAction >>= \t -> atomically $ writeTBQueue sndQ ([(corrId, EntityId sessId, t)], [])
-          pure Nothing
-          where
-            wait = do
-              ServerConfig {serverClientConcurrency} <- asks config
-              atomically $ do
-                used <- readTVar procThreads
-                when (used >= serverClientConcurrency) retry
-                writeTVar procThreads $! used + 1
-            signal = atomically $ modifyTVar' procThreads (\t -> t - 1)
+        forkProxiedCmd = forkCmd serverClientConcurrency corrId (EntityId sessId)
+    -- Run a slow command on a thread
+    forkCmd :: (ServerConfig s -> Int) -> CorrId -> EntityId -> M s BrokerMsg -> M s (Maybe a)
+    forkCmd concurrency corrId entId cmdAction = do
+      bracket_ wait signal . forkClient clnt (B.unpack $ "client $" <> encode sessionId <> " cmd") $
+        -- commands MUST be processed under a reasonable timeout or the client would halt
+        cmdAction >>= \t -> atomically $ writeTBQueue sndQ ([(corrId, entId, t)], [])
+      pure Nothing
+      where
+        wait = do
+          limit <- asks (concurrency . config)
+          atomically $ do
+            used <- readTVar procThreads
+            when (used >= limit) retry
+            writeTVar procThreads $! used + 1
+        signal = atomically $ modifyTVar' procThreads (\t -> t - 1)
+    rslvNamesEnv :: M s (Maybe NamesEnv)
+    rslvNamesEnv = do
+      st <- asks (rslvStats . serverStats)
+      incStat (rslvReqs st)
+      asks namesEnv >>= \case
+        Nothing -> incStat (rslvDisabled st) $> Nothing
+        Just nenv -> pure (Just nenv)
+    -- Runs on a forked thread so RSLV does not block other commands;
+    -- concurrency is limited by serverResolverConcurrency in forkCmd.
+    resolveNameMsg :: NamesEnv -> SimplexNameDomain -> M s BrokerMsg
+    resolveNameMsg nenv d = do
+      st <- asks (rslvStats . serverStats)
+      (selector, msg) <-
+        liftIO (resolveName nenv d) <&> \case
+          Right rec -> (rslvSucc, RNAME rec)
+          Left e@NOT_FOUND -> (rslvNotFound, ERR $ NAME e)
+          Left e -> (rslvResolverErrs, ERR $ NAME e)
+      incStat (selector st) $> msg
     transportErr :: TransportError -> ErrorType
     transportErr = PROXY . BROKER . TRANSPORT
     mkIncProxyStats :: MonadIO m => ProxyStats -> ProxyStats -> OwnServer -> (ProxyStats -> IORef Int) -> m ()
@@ -1489,7 +1519,10 @@ client
         SKEY k -> withQueue $ \q qr -> checkMode QMMessaging qr $ secureQueue_ q k
         SEND flags msgBody -> response <$> withQueue_ False err (sendMessage flags msgBody)
       Cmd SIdleClient PING -> pure $ response (corrId, NoEntity, PONG)
-      Cmd SProxyService (RFWD encBlock) -> response . (corrId,NoEntity,) <$> processForwardedCommand encBlock
+      Cmd SProxyService (RFWD encBlock) -> (response . (corrId, NoEntity,) =<<) <$> processForwardedCommand encBlock
+      Cmd SResolver (RSLV d) -> rslvNamesEnv >>= \case
+        Nothing -> pure $ response (corrId, NoEntity, ERR (NAME NO_RESOLVER))
+        Just nenv -> forkCmd serverResolverConcurrency corrId NoEntity (resolveNameMsg nenv d)
       Cmd SSenderLink command -> case command of
         LKEY k -> withQueue $ \q qr -> checkMode QMMessaging qr $ secureQueue_ q k $>> getQueueLink_ q qr
         LGET -> withQueue $ \q qr -> checkContact qr $ getQueueLink_ q qr
@@ -2087,8 +2120,8 @@ client
                   encNMsgMeta = C.cbEncrypt rcvNtfDhSecret ntfNonce (smpEncode msgMeta) 128
               pure $ MsgNtf {ntfMsgId = msgId, ntfTs = msgTs, ntfNonce, ntfEncMeta = fromRight "" encNMsgMeta}
 
-        processForwardedCommand :: EncFwdTransmission -> M s BrokerMsg
-        processForwardedCommand (EncFwdTransmission s) = fmap (either ERR RRES) . runExceptT $ do
+        processForwardedCommand :: EncFwdTransmission -> M s (Maybe BrokerMsg)
+        processForwardedCommand (EncFwdTransmission s) = fmap (either (Just . ERR) id) . runExceptT $ do
           THAuthServer {serverPrivKey, sessSecret'} <- maybe (throwE $ transportErr TENoServerAuth) pure (thAuth thParams')
           sessSecret <- maybe (throwE $ transportErr TENoServerAuth) pure sessSecret'
           let proxyNonce = C.cbNonce $ bs corrId
@@ -2103,28 +2136,31 @@ client
             t :| [] -> pure $ tDecodeServer clntTHParams t
             _ -> throwE BLOCK
           let clntThAuth = Just $ THAuthServer {serverPrivKey, peerClientService = Nothing, sessSecret' = Just clientSecret}
-          -- process forwarded command
-          r <-
-            lift (rejectOrVerify clntThAuth t') >>= \case
-              Left r -> pure r
-              -- rejectOrVerify filters allowed commands, no need to repeat it here.
-              -- INTERNAL is used because processCommand never returns Nothing for sender commands (could be extracted for better types).
-              -- `fst` removes empty message that is only returned for `SUB` command
-              Right t''@(_, (corrId', entId', _)) -> maybe (corrId', entId', ERR INTERNAL) fst <$> lift (processCommand Nothing fwdVersion (Right (M.empty, M.empty, M.empty)) t'')
-          -- encode response
-          r' <- case batchTransmissions clntTHParams [Right (Nothing, encodeTransmission clntTHParams r)] of
-            [] -> throwE INTERNAL -- at least 1 item is guaranteed from NonEmpty/Right
-            TBError _ _ : _ -> throwE BLOCK
-            TBTransmission b' _ : _ -> pure b'
-            TBTransmissions b' _ _ : _ -> pure b'
-          -- encrypt to client
-          r2 <- liftEitherWith (const BLOCK) $ EncResponse <$> C.cbEncrypt clientSecret (C.reverseNonce clientNonce) r' paddedProxiedTLength
-          -- encrypt to proxy
-          let fr = FwdResponse {fwdCorrId, fwdResponse = r2}
-              r3 = EncFwdResponse $ C.cbEncryptNoPad sessSecret (C.reverseNonce proxyNonce) (smpEncode fr)
+              encodeResp r = do
+                r' <- case batchTransmissions clntTHParams [Right (Nothing, encodeTransmission clntTHParams r)] of
+                  [] -> throwE INTERNAL -- at least 1 item is guaranteed from NonEmpty/Right
+                  TBError _ _ : _ -> throwE BLOCK
+                  TBTransmission b' _ : _ -> pure b'
+                  TBTransmissions b' _ _ : _ -> pure b'
+                r2 <- liftEitherWith (const BLOCK) $ EncResponse <$> C.cbEncrypt clientSecret (C.reverseNonce clientNonce) r' paddedProxiedTLength
+                let fr = FwdResponse {fwdCorrId, fwdResponse = r2}
+                pure $ RRES $ EncFwdResponse $ C.cbEncryptNoPad sessSecret (C.reverseNonce proxyNonce) (smpEncode fr)
+          -- the inner response, or Nothing if forked (RSLV).
+          r_ <- lift (rejectOrVerify clntThAuth t') >>= \case
+            -- rejectOrVerify filters allowed commands, no need to repeat it here.
+            Left r -> pure $ Just r
+            Right t''@(_, (corrId', entId', cmd')) -> case cmd' of
+              Cmd SResolver (RSLV d) -> lift $ rslvNamesEnv >>= \case
+                Nothing -> pure $ Just (corrId', entId', ERR (NAME NO_RESOLVER))
+                Just nenv -> forkCmd serverResolverConcurrency corrId NoEntity $ do
+                  msg <- resolveNameMsg nenv d
+                  either ERR id <$> runExceptT (encodeResp (corrId', entId', msg))
+              -- INTERNAL because processCommand never returns Nothing for sender commands;
+              -- `fst` drops the empty message only returned for SUB.
+              _ -> Just . maybe (corrId', entId', ERR INTERNAL) fst <$> lift (processCommand Nothing fwdVersion (Right (M.empty, M.empty, M.empty)) t'')
           stats <- asks serverStats
           incStat $ pMsgFwdsRecv stats
-          pure r3
+          traverse encodeResp r_
           where
             rejectOrVerify :: Maybe (THandleAuth 'TServer) -> SignedTransmissionOrError ErrorType Cmd -> M s (VerifiedTransmissionOrError s)
             rejectOrVerify clntThAuth = \case
@@ -2138,6 +2174,7 @@ client
                     Cmd SSender (SKEY _) -> True
                     Cmd SSenderLink (LKEY _) -> True
                     Cmd SSenderLink LGET -> True
+                    Cmd SResolver (RSLV _) -> True
                     _ -> False
                   verified = \case
                     VRVerified q -> Right (q, t'')
@@ -2472,4 +2509,4 @@ restoreServerStats msgStats_ ntfStats = asks (serverStatsBackupFile . config) >>
           logNote $ "error restoring server stats: " <> T.pack e
           liftIO exitFailure
     compareCounts name statsCnt storeCnt =
-      when (statsCnt /= storeCnt) $ logWarn $ name <> " count differs: stats: " <> tshow statsCnt <> ", store: " <> tshow storeCnt
+      when (statsCnt /= storeCnt) $ logWarn $ name <> " count differs: stats: " <> tshow statsCnt <> ", store: " <> tshow storeCnt