From f334843e016b054fd6f89800b3e283410d7583fd Mon Sep 17 00:00:00 2001 From: Evgeny Poberezkin Date: Thu, 25 Jul 2024 13:15:03 +0100 Subject: [PATCH] smp server: key-value storage (for short invitation links) (#1206) * rfc: short invitation links * shorter * types * server implementation, client functions * test * update rfc * test name --- rfcs/2024-06-21-short-links.md | 124 ++++++++++++++++++++++ simplexmq.cabal | 1 + src/Simplex/Messaging/Client.hs | 45 ++++++-- src/Simplex/Messaging/Protocol.hs | 72 ++++++++++++- src/Simplex/Messaging/Server.hs | 77 ++++++++++---- src/Simplex/Messaging/Server/DataStore.hs | 19 ++++ src/Simplex/Messaging/Server/Env/STM.hs | 9 +- tests/ServerTests.hs | 77 ++++++++++++++ 8 files changed, 391 insertions(+), 33 deletions(-) create mode 100644 rfcs/2024-06-21-short-links.md create mode 100644 src/Simplex/Messaging/Server/DataStore.hs diff --git a/rfcs/2024-06-21-short-links.md b/rfcs/2024-06-21-short-links.md new file mode 100644 index 000000000..df028a8ff --- /dev/null +++ b/rfcs/2024-06-21-short-links.md @@ -0,0 +1,124 @@ +# Short invitation links + +## Problem + +Long links look scary and unsafe for many users. While this is a perceived problem, rather than a real one, it hurts adoption. + +What is worse, long links do not fit in profile descriptions of other social networks where people might want to advertize their contact addresses. + +The current link size limitation is also the reason for not including PQ KEM keys into invitation links and addresses, postponing the moment when PQ-resistant encryption kicks in - if we include PQ KEM key into the link, the QR code will not be scannable. + +Additionally, if we store short links, they can also include chat preferences and public profile data. + +## Solution + +MITM-resistant link shortening. + +Instead of generating the random address that would resolve into the link - doing so would create the possibility of MITM by the server hosting this link - we can use private key as the link ID that will be passed to the accepting party, and the hash of the public key as ID for the server - the accepting party would present this key itself as ID and it will also be used for server to client encryption (see Protocol below). HKDF will be used to derive symmetric key from private key and used in secret_box together with random nonce (to allow replacing data with the same key but with a different nonce - nonce will be sent to the server too). secret_box construction is authenticated encryption, so it would protect from MITM. + +The proposed syntax: + +```abnf +shortConnectionRequest = connectionScheme "/" connReqType "#/" smpServer "/" linkHash +connReqType = %s"invitation" / %s"contact" +connectionScheme = (%s"https://" clientAppServer) / %s"simplex:" +clientAppServer = hostname [ ":" port ] + ; client app server, e.g. simplex.chat +smpServer = serverIdentity "@" srvHosts [":" port] ; no smp:// prefix, no escaping +srvHosts = ["," srvHosts] ; RFC1123, RFC5891 +linkHash = +``` + +If SMP server supports pages, its name can be used as clientAppServer, without repeating it after #, for a shorter link. + +Example link: + +``` +https://simplex.chat/contact/#0YuTwO05YJWS8rkjn9eLJDjQhFKvIYd8d4xG8X1blIU=@smp8.simplex.im/abcdefghij0123456789abcdefghij0123456789abc= +``` + +This link has the length of ~136 characters (256 bits), which is shorter than the full contact address (~310 characters) and much shorter than invitation links (~528 characters) even without post-quantum keys added to them. + +This size can be further reduced by +- use server domain in the link. +- do not include onion address, as the connection happens via proxy anyway, if it's untrusted server. +- not pinning server TLS certificate - the downside here is that while the attack that compromises TLS will not be able to substitute the link (because it's hash will not match), it will be able to intercept and to block it. +- using shorter hash, e.g. SHA128 - reducing the collision resistance. + +If the server is known, the client could use it's hash and onion address, otherwise it could trust the proxy to use any existing session with the same hostname or to accept the risk of interception - given that there is no risk of substitution. + +With the first two of these "improvements" the link could be ~122 characters: + +``` +https://smp8.simplex.im/contact/#0YuTwO05YJWS8rkjn9eLJDjQhFKvIYd8d4xG8X1blIU@/abcdefghij0123456789abcdefghij0123456789abc +``` + +If onion address is preserved the link will be ~184 characters (won't fit in Twitter 160 characters bio): + +``` +https://smp8.simplex.im/contact/#0YuTwO05YJWS8rkjn9eLJDjQhFKvIYd8d4xG8X1blIU@beccx4yfxxbvyhqypaavemqurytl6hozr47wfc7uuecacjqdvwpw2xid.onion/abcdefghij0123456789abcdefghij0123456789abc +``` + +If we implement it, the request to resolve the link would be made via proxied SMP command (to avoid the direct connection between the client and the recipient's server). + +Pros: +- a bit shorter link. +- possibility to include post-quantum keys into the full link keeping the same shortened link size. +- possibility to include chat profile of contact or group, and preferences, for a much better connection experience, and to show this information when the link sent in the conversation (clients can resolve them automatically, without connecting - it can be resolved by the sending clients). +- server will not have access to the link. + +Cons: +- protocol complexity. +- observers can access the link content, so for 1-time invitation we should only include permissions and not profile. + +Pros are a huge improvement of UX of connecting both within and from outside of the app (e.g., link can be resolved even before creating chat profile, as part of the onboarding). + +## Protocol + +To support short links, the SMP servers would provide a simple key-value store enabled by three additional commands: `WRT`, `CLR` and `READ` + +`WRT` command is used to store and to update values in the store. The size of the value is limited by the same size as sent messages (or, possibly, smaller - as connection information size used in confirmation messages) - the clients would use this fixed size irrespective of the content. `WRT` command will be sent with the data blob ID in the transaction entityId field, public authorization key used to authorize `WRT` and `CLR` commands (subsequent WRT commands to the existing key must use the same key), and the data blob. + +`CLR` command must use with the same entity ID and must be authorized by the same key. + +`READ` command must use the ID which hash would be equal of the ID used to create the data blob, and this ID would also be used as public authorization + +## Algorithm to store and to retrieve data blob. + +**Store data blob** + +- the data blob owner generates X25519 key pair: `(k, pk)`. +- private key `pk` will be included in the short link shared with the other party (only base64url encoded key bytes, not X509 encoding). +- `HKDF(pk)` will be used to encrypt the link data with secret_box before storing it on the server. +- the hash of public key `sha256(k)` will be used as ID by the owner to store and to remove the data blob (`WRT` and `CLR` commands). + +**Retrieve data blob** + +- the sender uses the public key `k` derived from the private key `pk` included in the link as entity ID to retrieve data blob (the server will compute the ID used by the owner as `sha256(k)` and will be able to look it up). This provides the quality that the traffic of the parties has no shared IDs inside TLS. It also means that unlike message queue creation, the ID to retrieve the blob was never sent to the blob creator, and also is not known to the server in advance (the second part is only an observation, in itself it does not increase security, as server has access to an encrypted blob anyway). +- note that the sender does not authorize the request to retrieve the blob, as it would not increase security unless a different key is used to authorize, and adding a key would increase link size. +- server session keys with the sender will be `(sk, spk)`, where `sk` is public key shared with the sender during session handshake, and `spk` is the private key known only to the server. +- this public key `k` will also be combined with server session key `spk` using `dh(k, spk)` to encrypt the response, so that there is no ciphertext in common in sent and received traffic for these blobs. Correlation ID will be used as a nonce for this encryption. +- having received the blob, the client can now decrypt it using secret_box with `HKDF(pk)`. + +Using the same key as ID for the request, and also to additionally encrypt the response allows to use a single key in the link, without increasing the link size. + +## Threat model + +**Compromised SMP server** + +can: +- delete link data. +- hide link selectively from some requests. + +cannot: +- undetectably replace link data. +- access unencrypted link data, whether it was or was not accessed by the accepting party. +- observe IP addresses of the users accessing link data. + +**Passive observer who observed short link**: + +can: +- access original unencrypted link data + +cannot: +- replace or delete the link data diff --git a/simplexmq.cabal b/simplexmq.cabal index 489b77eb5..20f6d016b 100644 --- a/simplexmq.cabal +++ b/simplexmq.cabal @@ -167,6 +167,7 @@ library Simplex.Messaging.Server Simplex.Messaging.Server.CLI Simplex.Messaging.Server.Control + Simplex.Messaging.Server.DataStore Simplex.Messaging.Server.Env.STM Simplex.Messaging.Server.Expiration Simplex.Messaging.Server.Information diff --git a/src/Simplex/Messaging/Client.hs b/src/Simplex/Messaging/Client.hs index 80fd65ffc..a8886abf7 100644 --- a/src/Simplex/Messaging/Client.hs +++ b/src/Simplex/Messaging/Client.hs @@ -58,6 +58,10 @@ module Simplex.Messaging.Client suspendSMPQueue, deleteSMPQueue, deleteSMPQueues, + createSMPDataBlob, + deleteSMPDataBlob, + getSMPDataBlob, + proxyGetSMPDataBlob, connectSMPProxiedRelay, proxySMPMessage, forwardSMPTransmission, @@ -748,9 +752,14 @@ secureSndSMPQueue c spKey sId senderKey = okSMPCommand (SKEY senderKey) c spKey {-# INLINE secureSndSMPQueue #-} proxySecureSndSMPQueue :: SMPClient -> ProxiedRelay -> SndPrivateAuthKey -> SenderId -> SndPublicAuthKey -> ExceptT SMPClientError IO (Either ProxyClientError ()) -proxySecureSndSMPQueue c proxiedRelay spKey sId senderKey = proxySMPCommand c proxiedRelay (Just spKey) sId (SKEY senderKey) +proxySecureSndSMPQueue c proxiedRelay spKey sId senderKey = proxySMPCommand c proxiedRelay (Just spKey) sId (SKEY senderKey) okResult {-# INLINE proxySecureSndSMPQueue #-} +okResult :: BrokerMsg -> Maybe () +okResult = \case + OK -> Just () + _ -> Nothing + -- | Enable notifications for the queue for push notifications server. -- -- https://github.com/simplex-chat/simplexmq/blob/master/protocol/simplex-messaging.md#enable-notifications-command @@ -792,7 +801,7 @@ sendSMPMessage c spKey sId flags msg = r -> throwE $ unexpectedResponse r proxySMPMessage :: SMPClient -> ProxiedRelay -> Maybe SndPrivateAuthKey -> SenderId -> MsgFlags -> MsgBody -> ExceptT SMPClientError IO (Either ProxyClientError ()) -proxySMPMessage c proxiedRelay spKey sId flags msg = proxySMPCommand c proxiedRelay spKey sId (SEND flags msg) +proxySMPMessage c proxiedRelay spKey sId flags msg = proxySMPCommand c proxiedRelay spKey sId (SEND flags msg) okResult -- | Acknowledge message delivery (server deletes the message). -- @@ -824,6 +833,25 @@ deleteSMPQueues :: SMPClient -> NonEmpty (RcvPrivateAuthKey, RecipientId) -> IO deleteSMPQueues = okSMPCommands DEL {-# INLINE deleteSMPQueues #-} +createSMPDataBlob :: SMPClient -> C.AAuthKeyPair -> BlobId -> DataBlob -> ExceptT SMPClientError IO () +createSMPDataBlob c (dKey, dpKey) dId blob = okSMPCommand (WRT dKey blob) c dpKey dId +{-# INLINE createSMPDataBlob #-} + +deleteSMPDataBlob :: SMPClient -> DataPrivateAuthKey -> BlobId -> ExceptT SMPClientError IO () +deleteSMPDataBlob = okSMPCommand CLR +{-# INLINE deleteSMPDataBlob #-} + +getSMPDataBlob :: SMPClient -> BlobId -> ExceptT SMPClientError IO EncDataBlob +getSMPDataBlob c dId = + sendSMPCommand c Nothing dId READ >>= \case + DATA encBlob -> pure encBlob + r -> throwE $ unexpectedResponse r + +proxyGetSMPDataBlob :: SMPClient -> ProxiedRelay -> BlobId -> ExceptT SMPClientError IO (Either ProxyClientError EncDataBlob) +proxyGetSMPDataBlob c proxiedRelay dId = proxySMPCommand c proxiedRelay Nothing dId READ $ \case + DATA encBlob -> Just encBlob + _ -> Nothing + -- send PRXY :: SMPServer -> Maybe BasicAuth -> Command Sender -- receives PKEY :: SessionId -> X.CertificateChain -> X.SignedExact X.PubKey -> BrokerMsg connectSMPProxiedRelay :: SMPClient -> SMPServer -> Maybe BasicAuth -> ExceptT SMPClientError IO ProxiedRelay @@ -912,8 +940,9 @@ proxySMPCommand :: Maybe SndPrivateAuthKey -> SenderId -> Command 'Sender -> - ExceptT SMPClientError IO (Either ProxyClientError ()) -proxySMPCommand c@ProtocolClient {thParams = proxyThParams, client_ = PClient {clientCorrId = g, tcpTimeout}} (ProxiedRelay sessionId v _ serverKey) spKey sId command = do + (BrokerMsg -> Maybe r) -> + ExceptT SMPClientError IO (Either ProxyClientError r) +proxySMPCommand c@ProtocolClient {thParams = proxyThParams, client_ = PClient {clientCorrId = g, tcpTimeout}} (ProxiedRelay sessionId v _ serverKey) spKey sId command toResult = do -- prepare params let serverThAuth = (\ta -> ta {serverPeerPubKey = serverKey}) <$> thAuth proxyThParams serverThParams = smpTHParamsSetVersion v proxyThParams {sessionId, thAuth = serverThAuth} @@ -939,9 +968,11 @@ proxySMPCommand c@ProtocolClient {thParams = proxyThParams, client_ = PClient {c case tParse serverThParams t' of t'' :| [] -> case tDecodeParseValidate serverThParams t'' of (_auth, _signed, (_c, _e, cmd)) -> case cmd of - Right OK -> pure $ Right () - Right (ERR e) -> throwE $ PCEProtocolError e -- this is the error from the destination relay - Right r' -> throwE $ unexpectedResponse r' + Right r' -> case toResult r' of + Just r'' -> pure $ Right r'' + Nothing -> case r' of + ERR e -> throwE $ PCEProtocolError e -- this is the error from the destination relay + _ -> throwE $ unexpectedResponse r' Left e -> throwE $ PCEResponseError e _ -> throwE $ PCETransportError TEBadBlock ERR e -> pure . Left $ ProxyProtocolError e -- this will not happen, this error is returned via Left diff --git a/src/Simplex/Messaging/Protocol.hs b/src/Simplex/Messaging/Protocol.hs index 63e3e4d98..57027a771 100644 --- a/src/Simplex/Messaging/Protocol.hs +++ b/src/Simplex/Messaging/Protocol.hs @@ -101,6 +101,7 @@ module Simplex.Messaging.Protocol CorrId (..), EntityId, QueueId, + BlobId, RecipientId, SenderId, NotifierId, @@ -114,6 +115,8 @@ module Simplex.Messaging.Protocol NtfPublicAuthKey, RcvNtfPublicDhKey, RcvNtfDhSecret, + DataPrivateAuthKey, + DataPublicAuthKey, Message (..), RcvMessage (..), MsgId, @@ -133,6 +136,8 @@ module Simplex.Messaging.Protocol FwdResponse (..), FwdTransmission (..), MsgFlags (..), + DataBlob (..), + EncDataBlob, initialSMPClientVersion, currentSMPClientVersion, userProtocol, @@ -374,6 +379,8 @@ type NotifierId = QueueId -- | SMP queue ID on the server. type QueueId = EntityId +type BlobId = EntityId + type EntityId = ByteString -- | Parameterized type for SMP protocol commands from all clients. @@ -395,6 +402,10 @@ data Command (p :: Party) where OFF :: Command Recipient DEL :: Command Recipient QUE :: Command Recipient + -- Data storage commands + WRT :: DataPublicAuthKey -> DataBlob -> Command Recipient + CLR :: Command Recipient + READ :: Command Sender -- SMP sender commands SKEY :: SndPublicAuthKey -> Command Sender -- SEND v1 has to be supported for encoding/decoding @@ -403,6 +414,7 @@ data Command (p :: Party) where PING :: Command Sender -- SMP notification subscriber commands NSUB :: Command Notifier + -- Proxy commands 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) @@ -476,6 +488,7 @@ data BrokerMsg where PRES :: EncResponse -> BrokerMsg -- proxy to client END :: BrokerMsg INFO :: QueueInfo -> BrokerMsg + DATA :: EncDataBlob -> BrokerMsg OK :: BrokerMsg ERR :: ErrorType -> BrokerMsg PONG :: BrokerMsg @@ -673,6 +686,9 @@ data CommandTag (p :: Party) where OFF_ :: CommandTag Recipient DEL_ :: CommandTag Recipient QUE_ :: CommandTag Recipient + WRT_ :: CommandTag Recipient + CLR_ :: CommandTag Recipient + READ_ :: CommandTag Sender SKEY_ :: CommandTag Sender SEND_ :: CommandTag Sender PING_ :: CommandTag Sender @@ -697,6 +713,7 @@ data BrokerMsgTag | PRES_ | END_ | INFO_ + | DATA_ | OK_ | ERR_ | PONG_ @@ -722,6 +739,9 @@ instance PartyI p => Encoding (CommandTag p) where OFF_ -> "OFF" DEL_ -> "DEL" QUE_ -> "QUE" + WRT_ -> "WRT" + CLR_ -> "CLR" + READ_ -> "READ" SKEY_ -> "SKEY" SEND_ -> "SEND" PING_ -> "PING" @@ -743,6 +763,9 @@ instance ProtocolMsgTag CmdTag where "OFF" -> Just $ CT SRecipient OFF_ "DEL" -> Just $ CT SRecipient DEL_ "QUE" -> Just $ CT SRecipient QUE_ + "WRT" -> Just $ CT SRecipient WRT_ + "CLR" -> Just $ CT SRecipient CLR_ + "READ" -> Just $ CT SSender READ_ "SKEY" -> Just $ CT SSender SKEY_ "SEND" -> Just $ CT SSender SEND_ "PING" -> Just $ CT SSender PING_ @@ -770,6 +793,7 @@ instance Encoding BrokerMsgTag where PRES_ -> "PRES" END_ -> "END" INFO_ -> "INFO" + DATA_ -> "DATA" OK_ -> "OK" ERR_ -> "ERR" PONG_ -> "PONG" @@ -786,6 +810,7 @@ instance ProtocolMsgTag BrokerMsgTag where "PRES" -> Just PRES_ "END" -> Just END_ "INFO" -> Just INFO_ + "DATA" -> Just DATA_ "OK" -> Just OK_ "ERR" -> Just ERR_ "PONG" -> Just PONG_ @@ -1157,12 +1182,38 @@ type RcvNtfPublicDhKey = C.PublicKeyX25519 -- | DH Secret used to encrypt notification metadata from server to recipient type RcvNtfDhSecret = C.DhSecretX25519 +-- | private key to authorize owner access to data blobs +type DataPrivateAuthKey = C.APrivateAuthKey + +-- | public key to authorize owner access to data blobs +type DataPublicAuthKey = C.APublicAuthKey + -- | SMP message server ID. type MsgId = ByteString -- | SMP message body. type MsgBody = ByteString +data DataBlob = DataBlob + { dataNonce :: C.CbNonce, + dataBody :: ByteString + } + deriving (Eq, Show) + +instance Encoding DataBlob where + smpEncode DataBlob {dataNonce, dataBody} = smpEncode (dataNonce, Tail dataBody) + smpP = do + (dataNonce, Tail dataBody) <- smpP + pure DataBlob {dataNonce, dataBody} + +instance StrEncoding DataBlob where + strEncode DataBlob {dataNonce, dataBody} = strEncode (dataNonce, dataBody) + strP = do + (dataNonce, dataBody) <- strP + pure DataBlob {dataNonce, dataBody} + +type EncDataBlob = ByteString + data ProtocolErrorType = PECmdSyntax | PECmdUnknown | PESession | PEBlock -- | Type for protocol errors. @@ -1307,6 +1358,9 @@ instance PartyI p => ProtocolEncoding SMPVersion ErrorType (Command p) where OFF -> e OFF_ DEL -> e DEL_ QUE -> e QUE_ + WRT k blob -> e (WRT_, ' ', k, blob) + CLR -> e CLR_ + READ -> e READ_ SKEY k -> e (SKEY_, ' ', k) SEND flags msg -> e (SEND_, ' ', flags, ' ', Tail msg) PING -> e PING_ @@ -1336,14 +1390,12 @@ instance PartyI p => ProtocolEncoding SMPVersion ErrorType (Command p) where SKEY _ | isNothing auth || B.null entId -> Left $ CMD NO_AUTH | otherwise -> Right cmd + READ -> entityNoAuthCmd PING -> noAuthCmd PRXY {} -> noAuthCmd - PFWD {} - | B.null entId -> Left $ CMD NO_ENTITY - | isNothing auth -> Right cmd - | otherwise -> Left $ CMD HAS_AUTH + PFWD {} -> entityNoAuthCmd RFWD _ -> noAuthCmd - -- other client commands must have both signature and queue ID + -- other client commands must have both signature and entity ID _ | isNothing auth || B.null entId -> Left $ CMD NO_AUTH | otherwise -> Right cmd @@ -1353,6 +1405,11 @@ instance PartyI p => ProtocolEncoding SMPVersion ErrorType (Command p) where noAuthCmd | isNothing auth && B.null entId = Right cmd | otherwise = Left $ CMD HAS_AUTH + entityNoAuthCmd :: Either ErrorType (Command p) + entityNoAuthCmd + | B.null entId = Left $ CMD NO_ENTITY + | isJust auth = Left $ CMD HAS_AUTH + | otherwise = Right cmd instance ProtocolEncoding SMPVersion ErrorType Cmd where type Tag Cmd = CmdTag @@ -1378,10 +1435,13 @@ instance ProtocolEncoding SMPVersion ErrorType Cmd where OFF_ -> pure OFF DEL_ -> pure DEL QUE_ -> pure QUE + WRT_ -> WRT <$> _smpP <*> smpP + CLR_ -> pure CLR CT SSender tag -> Cmd SSender <$> case tag of SKEY_ -> SKEY <$> _smpP SEND_ -> SEND <$> _smpP <*> (unTail <$> _smpP) + READ_ -> pure READ PING_ -> pure PING RFWD_ -> RFWD <$> (EncFwdTransmission . unTail <$> _smpP) CT SProxiedClient tag -> @@ -1412,6 +1472,7 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where PRES (EncResponse encBlock) -> e (PRES_, ' ', Tail encBlock) END -> e END_ INFO info -> e (INFO_, ' ', info) + DATA body -> e (DATA_, ' ', Tail body) OK -> e OK_ ERR err -> e (ERR_, ' ', err) PONG -> e PONG_ @@ -1437,6 +1498,7 @@ instance ProtocolEncoding SMPVersion ErrorType BrokerMsg where PRES_ -> PRES <$> (EncResponse . unTail <$> _smpP) END_ -> pure END INFO_ -> INFO <$> _smpP + DATA_ -> DATA . unTail <$> _smpP OK_ -> pure OK ERR_ -> ERR <$> _smpP PONG_ -> pure PONG diff --git a/src/Simplex/Messaging/Server.hs b/src/Simplex/Messaging/Server.hs index 34c7dd561..33af8da0e 100644 --- a/src/Simplex/Messaging/Server.hs +++ b/src/Simplex/Messaging/Server.hs @@ -43,6 +43,8 @@ import Control.Monad.Except import Control.Monad.IO.Unlift import Control.Monad.Reader import Control.Monad.Trans.Except +import qualified Crypto.PubKey.Curve25519 as X25519 +import qualified Crypto.Error as CE import Crypto.Random import Control.Monad.STM (retry) import Data.Bifunctor (first) @@ -78,6 +80,7 @@ import Simplex.Messaging.Encoding import Simplex.Messaging.Encoding.String import Simplex.Messaging.Protocol import Simplex.Messaging.Server.Control +import Simplex.Messaging.Server.DataStore import Simplex.Messaging.Server.Env.STM as Env import Simplex.Messaging.Server.Expiration import Simplex.Messaging.Server.MsgStore @@ -631,14 +634,13 @@ receive h@THandle {params = THandleParams {thAuth}} Client {rcvQ, sndQ, rcvActiv write sndQ errs write rcvQ cmds where - cmdAction :: ServerStats -> SignedTransmission ErrorType Cmd -> M (Either (Transmission BrokerMsg) (Maybe QueueRec, Transmission Cmd)) + cmdAction :: ServerStats -> SignedTransmission ErrorType Cmd -> M (Either (Transmission BrokerMsg) (VerificationResult, Transmission Cmd)) cmdAction stats (tAuth, authorized, (corrId, entId, 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 where verified = \case - VRVerified qr -> pure $ Right (qr, (corrId, entId, cmd)) VRFailed -> do case cmd of Cmd _ SEND {} -> incStat $ msgSentAuth stats @@ -646,6 +648,7 @@ receive h@THandle {params = THandleParams {thAuth}} Client {rcvQ, sndQ, rcvActiv Cmd _ GET -> incStat $ msgGetAuth stats _ -> pure () pure $ Left (corrId, entId, ERR AUTH) + vRes -> pure $ Right (vRes, (corrId, entId, cmd)) write q = mapM_ (atomically . writeTBQueue q) . L.nonEmpty send :: Transport c => MVar (THandleSMP c 'TServer) -> Client -> IO () @@ -697,8 +700,6 @@ disconnectTransport THandle {connection, params = THandleParams {sessionId}} rcv ts <- max <$> readTVarIO rcvActiveAt <*> readTVarIO sndActiveAt if systemSeconds ts < old then closeConnection connection else loop -data VerificationResult = VRVerified (Maybe QueueRec) | VRFailed - -- This function verifies queue command authorization, with the objective to have constant time between the three AUTH error scenarios: -- - the queue and party key exist, and the provided authorization has type matching queue key, but it is made with the different key. -- - the queue and party key exist, but the provided authorization has incorrect type. @@ -706,13 +707,16 @@ data VerificationResult = VRVerified (Maybe QueueRec) | VRFailed -- In all cases, the time of the verification should depend only on the provided authorization type, -- a dummy key is used to run verification in the last two cases, and failure is returned irrespective of the result. verifyTransmission :: Maybe (THandleAuth 'TServer, C.CbNonce) -> Maybe TransmissionAuth -> ByteString -> QueueId -> Cmd -> M VerificationResult -verifyTransmission auth_ tAuth authorized queueId cmd = +verifyTransmission auth_ tAuth authorized entId cmd = case cmd of Cmd SRecipient (NEW k _ _ _ _) -> pure $ Nothing `verifiedWith` k + Cmd SRecipient (WRT k _) -> (\d -> d `verifiedData` (verify k && maybe True ((k ==) . dataKey) d)) <$> getData entId + Cmd SRecipient CLR -> maybe dummyVerify (\d -> Just d `verifiedData` verify (dataKey d)) <$> getData entId Cmd SRecipient _ -> verifyQueue (\q -> Just q `verifiedWith` recipientKey q) <$> get SRecipient -- SEND will be accepted without authorization before the queue is secured with KEY or SKEY command Cmd SSender (SKEY k) -> verifyQueue (\q -> Just q `verifiedWith` k) <$> get SSender Cmd SSender SEND {} -> verifyQueue (\q -> Just q `verified` maybe (isNothing tAuth) verify (senderKey q)) <$> get SSender + Cmd SSender READ -> maybe VRFailed (VRVerifiedData . Just) <$> getData (C.sha256Hash entId) Cmd SSender PING -> pure $ VRVerified Nothing Cmd SSender RFWD {} -> pure $ VRVerified Nothing -- NSUB will not be accepted without authorization @@ -725,10 +729,13 @@ verifyTransmission auth_ tAuth authorized queueId cmd = verifyQueue = either (const dummyVerify) verified q cond = if cond then VRVerified q else VRFailed verifiedWith q k = q `verified` verify k + verifiedData d cond = if cond then VRVerifiedData d else VRFailed get :: DirectParty p => SParty p -> M (Either ErrorType QueueRec) get party = do st <- asks queueStore - atomically $ getQueue st party queueId + atomically $ getQueue st party entId + getData :: BlobId -> M (Maybe DataRec) + getData blobId = atomically . TM.lookup blobId =<< asks dataStore verifyCmdAuthorization :: Maybe (THandleAuth 'TServer, C.CbNonce) -> Maybe TransmissionAuth -> ByteString -> C.APublicAuthKey -> Bool verifyCmdAuthorization auth_ tAuth authorized key = maybe False (verify key) tAuth @@ -873,16 +880,15 @@ client thParams' clnt@Client {subscriptions, ntfSubscriptions, rcvQ, sndQ, sessi mkIncProxyStats ps psOwn own sel = do incStat $ sel ps when own $ incStat $ sel psOwn - processCommand :: (Maybe QueueRec, Transmission Cmd) -> M (Maybe (Transmission BrokerMsg)) - processCommand (qr_, (corrId, entId, cmd)) = case cmd of + processCommand :: (VerificationResult, Transmission Cmd) -> M (Maybe (Transmission BrokerMsg)) + processCommand (vRes, (corrId, entId, cmd)) = case cmd of Cmd SProxiedClient command -> processProxiedCmd (corrId, entId, command) Cmd SSender command -> Just <$> case command of - SKEY sKey -> (corrId,entId,) <$> case qr_ of - Just QueueRec {sndSecure, recipientId} - | sndSecure -> secureQueue_ "SKEY" recipientId sKey - | otherwise -> pure $ ERR AUTH - Nothing -> pure $ ERR INTERNAL + SKEY sKey -> + withQueue $ \QueueRec {sndSecure, recipientId} -> + (corrId,entId,) <$> if sndSecure then secureQueue_ "SKEY" recipientId sKey else pure $ ERR AUTH SEND flags msgBody -> withQueue $ \qr -> sendMessage qr flags msgBody + READ -> getDataBlob PING -> pure (corrId, "", PONG) RFWD encBlock -> (corrId, "",) <$> processForwardedCommand encBlock Cmd SNotifier NSUB -> Just <$> subscribeNotifications @@ -901,14 +907,16 @@ client thParams' clnt@Client {subscriptions, ntfSubscriptions, rcvQ, sndQ, sessi SUB -> withQueue (`subscribeQueue` entId) GET -> withQueue getMessage ACK msgId -> withQueue (`acknowledgeMsg` msgId) - KEY sKey -> (corrId,entId,) <$> case qr_ of - Just QueueRec {recipientId} -> secureQueue_ "KEY" recipientId sKey - Nothing -> pure $ ERR INTERNAL + KEY sKey -> + withQueue $ \QueueRec {recipientId} -> + (corrId,entId,) <$> secureQueue_ "KEY" recipientId sKey NKEY nKey dhKey -> addQueueNotifier_ st nKey dhKey NDEL -> deleteQueueNotifier_ st OFF -> suspendQueue_ st DEL -> delQueueAndMsgs st QUE -> withQueue getQueueInfo + WRT key blob -> storeDataBlob key blob + CLR -> deleteDataBlob where createQueue :: QueueStore -> RcvPublicAuthKey -> RcvPublicDhKey -> SubscriptionMode -> SenderCanSecure -> M (Transmission BrokerMsg) createQueue st recipientKey dhKey subMode sndSecure = time "NEW" $ do @@ -1067,7 +1075,9 @@ client thParams' clnt@Client {subscriptions, ntfSubscriptions, rcvQ, sndQ, sessi pure r withQueue :: (QueueRec -> M (Transmission BrokerMsg)) -> M (Transmission BrokerMsg) - withQueue action = maybe (pure $ err AUTH) action qr_ + withQueue action = case vRes of + VRVerified (Just qr) -> action qr + _ -> pure $ err INTERNAL subscribeNotifications :: M (Transmission BrokerMsg) subscribeNotifications = time "NSUB" . atomically $ do @@ -1278,7 +1288,7 @@ client thParams' clnt@Client {subscriptions, ntfSubscriptions, rcvQ, sndQ, sessi incStat $ pMsgFwdsRecv stats pure $ RRES r3 where - rejectOrVerify :: Maybe (THandleAuth 'TServer) -> SignedTransmission ErrorType Cmd -> M (Either (Transmission BrokerMsg) (Maybe QueueRec, Transmission Cmd)) + rejectOrVerify :: Maybe (THandleAuth 'TServer) -> SignedTransmission ErrorType Cmd -> M (Either (Transmission BrokerMsg) (VerificationResult, Transmission Cmd)) rejectOrVerify clntThAuth (tAuth, authorized, (corrId', entId', cmdOrError)) = case cmdOrError of Left e -> pure $ Left (corrId', entId', ERR e) @@ -1289,10 +1299,12 @@ client thParams' clnt@Client {subscriptions, ntfSubscriptions, rcvQ, sndQ, sessi allowed = case cmd' of Cmd SSender SEND {} -> True Cmd SSender (SKEY _) -> True + Cmd SSender READ -> True _ -> False verified = \case - VRVerified qr -> Right (qr, (corrId', entId', cmd')) VRFailed -> Left (corrId', entId', ERR AUTH) + vRes' -> Right (vRes', (corrId', entId', cmd')) + deliverMessage :: T.Text -> QueueRec -> RecipientId -> Sub -> Maybe Message -> M (Transmission BrokerMsg) deliverMessage name qr rId s@Sub {subThread} msg_ = time (name <> " deliver") . atomically $ readTVar subThread >>= \case @@ -1360,6 +1372,33 @@ client thParams' clnt@Client {subscriptions, ntfSubscriptions, rcvQ, sndQ, sessi qDelivered <- decodeLatin1 . encode <$$> tryReadTMVar delivered pure QSub {qSubThread, qDelivered} + storeDataBlob :: DataPublicAuthKey -> DataBlob -> M (Transmission BrokerMsg) + storeDataBlob dataKey dataBlob + | B.length (dataBody dataBlob) > e2eEncMessageLength = pure $ err LARGE_MSG + | otherwise = ok <$ (atomically . TM.insert entId d =<< asks dataStore) + where + d = DataRec {dataId = entId, dataKey, dataBlob} + + deleteDataBlob :: M (Transmission BrokerMsg) + deleteDataBlob = ok <$ (atomically . TM.delete entId =<< asks dataStore) + + getDataBlob :: M (Transmission BrokerMsg) + getDataBlob = case vRes of + VRVerifiedData (Just DataRec {dataBlob}) -> + case thAuth thParams' of + Nothing -> pure $ err $ transportErr TENoServerAuth + Just THAuthServer {serverPrivKey} -> case X25519.publicKey entId of + CE.CryptoFailed _ -> pure $ err AUTH + CE.CryptoPassed k -> do + let secret = C.dh' (C.PublicKeyX25519 k) serverPrivKey + nonce = C.cbNonce $ bs corrId + THandleParams {thVersion} = thParams' + pure . (corrId,entId,) $ + case C.cbEncrypt secret nonce (smpEncode dataBlob) (maxMessageLength thVersion) of + Left _ -> ERR CRYPTO + Right encBlob -> DATA encBlob + _ -> pure $ err INTERNAL + ok :: Transmission BrokerMsg ok = (corrId, entId, OK) diff --git a/src/Simplex/Messaging/Server/DataStore.hs b/src/Simplex/Messaging/Server/DataStore.hs new file mode 100644 index 000000000..56f339e02 --- /dev/null +++ b/src/Simplex/Messaging/Server/DataStore.hs @@ -0,0 +1,19 @@ +{-# LANGUAGE NamedFieldPuns #-} +{-# LANGUAGE OverloadedStrings #-} + +module Simplex.Messaging.Server.DataStore where + +import Simplex.Messaging.Encoding.String +import Simplex.Messaging.Protocol + +data DataRec = DataRec + { dataId :: BlobId, + dataKey :: DataPublicAuthKey, + dataBlob :: DataBlob + } + +instance StrEncoding DataRec where + strEncode DataRec {dataId, dataKey, dataBlob} = strEncode (Str "v1", dataId, dataKey, dataBlob) + strP = do + (dataId, dataKey, dataBlob) <- "v1 " *> strP + pure DataRec {dataId, dataKey, dataBlob} diff --git a/src/Simplex/Messaging/Server/Env/STM.hs b/src/Simplex/Messaging/Server/Env/STM.hs index dc77b7481..3524ad46b 100644 --- a/src/Simplex/Messaging/Server/Env/STM.hs +++ b/src/Simplex/Messaging/Server/Env/STM.hs @@ -28,6 +28,7 @@ import Simplex.Messaging.Client.Agent (SMPClientAgent, SMPClientAgentConfig, new import Simplex.Messaging.Crypto (KeyHash (..)) import qualified Simplex.Messaging.Crypto as C import Simplex.Messaging.Protocol +import Simplex.Messaging.Server.DataStore import Simplex.Messaging.Server.Expiration import Simplex.Messaging.Server.Information import Simplex.Messaging.Server.MsgStore.STM @@ -118,6 +119,7 @@ data Env = Env serverIdentity :: KeyHash, queueStore :: QueueStore, msgStore :: STMMsgStore, + dataStore :: TMap BlobId DataRec, random :: TVar ChaChaDRG, storeLog :: Maybe (StoreLog 'WriteMode), tlsServerParams :: T.ServerParams, @@ -144,11 +146,13 @@ newtype ProxyAgent = ProxyAgent type ClientId = Int +data VerificationResult = VRVerified (Maybe QueueRec) | VRVerifiedData (Maybe DataRec) | VRFailed + data Client = Client { clientId :: ClientId, subscriptions :: TMap RecipientId Sub, ntfSubscriptions :: TMap NotifierId (), - rcvQ :: TBQueue (NonEmpty (Maybe QueueRec, Transmission Cmd)), + rcvQ :: TBQueue (NonEmpty (VerificationResult, Transmission Cmd)), sndQ :: TBQueue (NonEmpty (Transmission BrokerMsg)), msgQ :: TBQueue (NonEmpty (Transmission BrokerMsg)), procThreads :: TVar Int, @@ -205,6 +209,7 @@ newEnv config@ServerConfig {caCertificateFile, certificateFile, privateKeyFile, server <- atomically newServer queueStore <- atomically newQueueStore msgStore <- atomically newMsgStore + dataStore <- atomically TM.empty random <- liftIO C.newRandom storeLog <- restoreQueues queueStore `mapM` storeLogFile tlsServerParams <- loadTLSServerParams caCertificateFile certificateFile privateKeyFile (alpn transportConfig) @@ -215,7 +220,7 @@ newEnv config@ServerConfig {caCertificateFile, certificateFile, privateKeyFile, clientSeq <- newTVarIO 0 clients <- newTVarIO mempty proxyAgent <- atomically $ newSMPProxyAgent smpAgentCfg random - pure Env {config, serverInfo, server, serverIdentity, queueStore, msgStore, random, storeLog, tlsServerParams, serverStats, sockets, clientSeq, clients, proxyAgent} + pure Env {config, serverInfo, server, serverIdentity, queueStore, msgStore, dataStore, random, storeLog, tlsServerParams, serverStats, sockets, clientSeq, clients, proxyAgent} where restoreQueues :: QueueStore -> FilePath -> IO (StoreLog 'WriteMode) restoreQueues QueueStore {queues, senders, notifiers} f = do diff --git a/tests/ServerTests.hs b/tests/ServerTests.hs index 9534b7902..50d3f5dad 100644 --- a/tests/ServerTests.hs +++ b/tests/ServerTests.hs @@ -21,7 +21,10 @@ import Control.Concurrent.STM import Control.Exception (SomeException, try) import Control.Monad import Control.Monad.IO.Class +import Crypto.Hash (SHA512) +import qualified Crypto.KDF.HKDF as H import Data.Bifunctor (first) +import qualified Data.ByteArray as BA import Data.ByteString.Base64 import Data.ByteString.Char8 (ByteString) import qualified Data.ByteString.Char8 as B @@ -68,6 +71,7 @@ serverTests t@(ATransport t') = do testMsgExpireOnSend t' testMsgExpireOnInterval t' testMsgNOTExpireOnInterval t' + describe "Data blobs" $ testDataBlobs t' pattern Resp :: CorrId -> QueueId -> BrokerMsg -> SignedTransmission ErrorType BrokerMsg pattern Resp corrId queueId command <- (_, _, (corrId, queueId, Right command)) @@ -914,6 +918,79 @@ testMsgNOTExpireOnInterval t = Nothing -> return () Just _ -> error "nothing else should be delivered" +testDataBlobs :: forall c. Transport c => TProxy c -> Spec +testDataBlobs t = + it "should store, retrieve, update and delete data blob directly from the server" $ + smpTest2 t $ \r s -> do + g <- C.newRandom + -- k: ID to retrive blob. + -- pk: part of the link sent to the accepting party (Sender role), + -- also key material for HKDF to derive key to e2e encrypt blob. + -- hash(k): ID used to store blob + -- (k, pk): used to agree additional server-to-client encryption when retrieving blob, + -- using DH with server session keys. + (C.PublicKeyX25519 k, pk'@(C.PrivateKeyX25519 pk _)) <- atomically $ C.generateKeyPair @'C.X25519 g + (blobKey, blobPKey) <- atomically $ C.generateAuthKeyPair C.SEd25519 g + let kBytes = BA.convert k :: ByteString + rBlobId = C.sha256Hash kBytes + sBlobId = kBytes + pkBytes = BA.convert pk :: ByteString + ikm = pkBytes + salt = "" :: ByteString + info = "SimpleXDataBlob" :: ByteString + prk = H.extract salt ikm :: H.PRK SHA512 + skBytes = H.expand prk info 32 + origData = "hello" + origData2 = "hello 2" + dataNonce <- atomically $ C.randomCbNonce g + Right sk <- pure $ C.sbKey skBytes + -- store and retrieve blob + Right dataBody <- pure $ C.sbEncrypt sk dataNonce origData e2eEncConfirmationLength + let blob = DataBlob {dataNonce, dataBody} + -- storing data signed with the incorrect key fails (not matching key in command) + (_, blobPKey') <- atomically $ C.generateAuthKeyPair C.SEd25519 g + Resp "0" _ (ERR AUTH) <- signSendRecv r blobPKey' ("0", rBlobId, WRT blobKey blob) + -- correct key succeeds + Resp "1" _ OK <- signSendRecv r blobPKey ("1", rBlobId, WRT blobKey blob) + Resp "2" _ (DATA encBlob) <- sendRecv s ("", "2", sBlobId, READ) + THandle {params = THandleParams {thAuth = Just THAuthClient {serverPeerPubKey}}} <- pure s + let ss = C.dh' serverPeerPubKey pk' + respNonce = C.cbNonce "2" -- correlation ID sent in READ request + Right blobStr <- pure $ C.cbDecrypt ss respNonce encBlob + Right blob'@DataBlob {dataNonce = dataNonce', dataBody = body'} <- pure $ smpDecode blobStr + blob' `shouldBe` blob + Right origData' <- pure $ C.sbDecrypt sk dataNonce' body' + origData' `shouldBe` origData + -- update and retrieve blob + dataNonce2 <- atomically $ C.randomCbNonce g + Right dataBody2 <- pure $ C.sbEncrypt sk dataNonce2 origData2 e2eEncConfirmationLength + let blob2 = DataBlob {dataNonce = dataNonce2, dataBody = dataBody2} + -- storing data under the same ID but signed with the different key fails (even if it matches key in command) + (blobKey'', blobPKey'') <- atomically $ C.generateAuthKeyPair C.SEd25519 g + Resp "3" _ (ERR AUTH) <- signSendRecv r blobPKey'' ("3", rBlobId, WRT blobKey'' blob2) + -- same key but signed with the wrong key also fails + Resp "4" _ (ERR AUTH) <- signSendRecv r blobPKey'' ("4", rBlobId, WRT blobKey blob2) + -- same key bsucceeds + Resp "5" _ OK <- signSendRecv r blobPKey ("5", rBlobId, WRT blobKey blob2) + Resp "6" _ (DATA encBlob2) <- sendRecv s ("", "6", sBlobId, READ) + let respNonce2 = C.cbNonce "6" -- correlation ID sent in READ request + Right blobStr2 <- pure $ C.cbDecrypt ss respNonce2 encBlob2 + Right blob2'@DataBlob {dataNonce = dataNonce2', dataBody = body2'} <- pure $ smpDecode blobStr2 + blob2' `shouldBe` blob2 + Right origData2' <- pure $ C.sbDecrypt sk dataNonce2' body2' + origData2' `shouldBe` origData2 + -- remove data blob + -- incorrect ID fails + Resp "7" _ (ERR AUTH) <- signSendRecv r blobPKey ("7", sBlobId, CLR) + -- incorrect key fails + Resp "8" _ (ERR AUTH) <- signSendRecv r blobPKey'' ("8", rBlobId, CLR) + Resp "9" _ (DATA encBlob2') <- sendRecv s ("", "9", sBlobId, READ) + encBlob2' `shouldBe` encBlob2' + -- correct key and ID succeed + Resp "10" _ OK <- signSendRecv r blobPKey ("10", rBlobId, CLR) + Resp "11" _ (ERR AUTH) <- sendRecv s ("", "11", sBlobId, READ) + pure () + samplePubKey :: C.APublicVerifyKey samplePubKey = C.APublicVerifyKey C.SEd25519 "MCowBQYDK2VwAyEAfAOflyvbJv1fszgzkQ6buiZJVgSpQWsucXq7U6zjMgY="