tls-2.0.0: Network/TLS/Packet.hs
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE RecordWildCards #-}
-- | The Packet module contains everything necessary to serialize and
-- deserialize things with only explicit parameters, no TLS state is
-- involved here.
module Network.TLS.Packet (
-- * params for encoding and decoding
CurrentParams (..),
-- * marshall functions for header messages
decodeHeader,
encodeHeader,
-- * marshall functions for alert messages
decodeAlert,
decodeAlerts,
encodeAlerts,
-- * marshall functions for handshake messages
decodeHandshakeRecord,
decodeHandshake,
encodeHandshake,
encodeCertificate,
-- * marshall functions for change cipher spec message
decodeChangeCipherSpec,
encodeChangeCipherSpec,
decodePreMainSecret,
encodePreMainSecret,
encodeSignedDHParams,
encodeSignedECDHParams,
decodeReallyServerKeyXchgAlgorithmData,
-- * generate things for packet content
generateMainSecret,
generateExtendedMainSecret,
generateKeyBlock,
generateClientFinished,
generateServerFinished,
-- * for extensions parsing
getSignatureHashAlgorithm,
putSignatureHashAlgorithm,
getBinaryVersion,
putBinaryVersion,
getClientRandom32,
putClientRandom32,
getServerRandom32,
putServerRandom32,
getExtensions,
putExtension,
getSession,
putSession,
putDNames,
getDNames,
getHandshakeType,
) where
import Data.ByteArray (ByteArrayAccess)
import qualified Data.ByteArray as B (convert)
import qualified Data.ByteString as B
import Data.X509 (
CertificateChain,
CertificateChainRaw (..),
decodeCertificateChain,
encodeCertificateChain,
)
import Network.TLS.Cipher (Cipher (..), CipherKeyExchangeType (..))
import Network.TLS.Crypto
import Network.TLS.Imports
import Network.TLS.MAC
import Network.TLS.Struct
import Network.TLS.Util.ASN1
import Network.TLS.Wire
data CurrentParams = CurrentParams
{ cParamsVersion :: Version
-- ^ current protocol version
, cParamsKeyXchgType :: Maybe CipherKeyExchangeType
-- ^ current key exchange type
}
deriving (Show, Eq)
{- marshall helpers -}
getBinaryVersion :: Get Version
getBinaryVersion = Version <$> getWord16
putBinaryVersion :: Version -> Put
putBinaryVersion (Version ver) = putWord16 ver
getHeaderType :: Get ProtocolType
getHeaderType = ProtocolType <$> getWord8
putHeaderType :: ProtocolType -> Put
putHeaderType (ProtocolType pt) = putWord8 pt
getHandshakeType :: Get HandshakeType
getHandshakeType = HandshakeType <$> getWord8
{-
- decode and encode headers
-}
decodeHeader :: ByteString -> Either TLSError Header
decodeHeader =
runGetErr "header" $ Header <$> getHeaderType <*> getBinaryVersion <*> getWord16
encodeHeader :: Header -> ByteString
encodeHeader (Header pt ver len) = runPut (putHeaderType pt >> putBinaryVersion ver >> putWord16 len)
{- FIXME check len <= 2^14 -}
{-
- decode and encode ALERT
-}
decodeAlert :: Get (AlertLevel, AlertDescription)
decodeAlert = do
al <- AlertLevel <$> getWord8
ad <- AlertDescription <$> getWord8
return (al, ad)
decodeAlerts :: ByteString -> Either TLSError [(AlertLevel, AlertDescription)]
decodeAlerts = runGetErr "alerts" loop
where
loop = do
r <- remaining
if r == 0
then return []
else (:) <$> decodeAlert <*> loop
encodeAlerts :: [(AlertLevel, AlertDescription)] -> ByteString
encodeAlerts l = runPut $ mapM_ encodeAlert l
where
encodeAlert (al, ad) = putWord8 (fromAlertLevel al) >> putWord8 (fromAlertDescription ad)
{- decode and encode HANDSHAKE -}
decodeHandshakeRecord :: ByteString -> GetResult (HandshakeType, ByteString)
decodeHandshakeRecord = runGet "handshake-record" $ do
ty <- getHandshakeType
content <- getOpaque24
return (ty, content)
decodeHandshake
:: CurrentParams -> HandshakeType -> ByteString -> Either TLSError Handshake
decodeHandshake cp ty = runGetErr ("handshake[" ++ show ty ++ "]") $ case ty of
HandshakeType_HelloRequest -> decodeHelloRequest
HandshakeType_ClientHello -> decodeClientHello
HandshakeType_ServerHello -> decodeServerHello
HandshakeType_Certificate -> decodeCertificate
HandshakeType_ServerKeyXchg -> decodeServerKeyXchg cp
HandshakeType_CertRequest -> decodeCertRequest cp
HandshakeType_ServerHelloDone -> decodeServerHelloDone
HandshakeType_CertVerify -> decodeCertVerify cp
HandshakeType_ClientKeyXchg -> decodeClientKeyXchg cp
HandshakeType_Finished -> decodeFinished
HandshakeType_NewSessionTicket -> decodeNewSessionTicket
x -> fail $ "Unsupported HandshakeType " ++ show x
decodeHelloRequest :: Get Handshake
decodeHelloRequest = return HelloRequest
decodeClientHello :: Get Handshake
decodeClientHello = do
ver <- getBinaryVersion
random <- getClientRandom32
session <- getSession
ciphers <- getWords16
compressions <- getWords8
r <- remaining
exts <-
if r > 0
then fromIntegral <$> getWord16 >>= getExtensions
else do
rest <- remaining
_ <- getBytes rest
return []
let ch = CH session ciphers exts
return $ ClientHello ver random compressions ch
decodeServerHello :: Get Handshake
decodeServerHello = do
ver <- getBinaryVersion
random <- getServerRandom32
session <- getSession
cipherid <- getWord16
compressionid <- getWord8
r <- remaining
exts <-
if r > 0
then fromIntegral <$> getWord16 >>= getExtensions
else return []
return $ ServerHello ver random session cipherid compressionid exts
decodeServerHelloDone :: Get Handshake
decodeServerHelloDone = return ServerHelloDone
decodeCertificate :: Get Handshake
decodeCertificate = do
certsRaw <-
CertificateChainRaw
<$> (getWord24 >>= \len -> getList (fromIntegral len) getCertRaw)
case decodeCertificateChain certsRaw of
Left (i, s) -> fail ("error certificate parsing " ++ show i ++ ":" ++ s)
Right cc -> return $ Certificate cc
where
getCertRaw = getOpaque24 >>= \cert -> return (3 + B.length cert, cert)
decodeFinished :: Get Handshake
decodeFinished = Finished <$> (remaining >>= getBytes)
decodeNewSessionTicket :: Get Handshake
decodeNewSessionTicket = NewSessionTicket <$> getWord32 <*> getOpaque16
decodeCertRequest :: CurrentParams -> Get Handshake
decodeCertRequest _cp = do
certTypes <- map CertificateType <$> getWords8
sigHashAlgs <- getWord16 >>= getSignatureHashAlgorithms
CertRequest certTypes sigHashAlgs <$> getDNames
where
getSignatureHashAlgorithms len =
getList (fromIntegral len) (getSignatureHashAlgorithm >>= \sh -> return (2, sh))
-- | Decode a list CA distinguished names
getDNames :: Get [DistinguishedName]
getDNames = do
dNameLen <- getWord16
-- FIXME: Decide whether to remove this check completely or to make it an option.
-- when (cParamsVersion cp < TLS12 && dNameLen < 3) $ fail "certrequest distinguishname not of the correct size"
getList (fromIntegral dNameLen) getDName
where
getDName = do
dName <- getOpaque16
when (B.length dName == 0) $ fail "certrequest: invalid DN length"
dn <-
either fail return $ decodeASN1Object "cert request DistinguishedName" dName
return (2 + B.length dName, dn)
decodeCertVerify :: CurrentParams -> Get Handshake
decodeCertVerify cp = CertVerify <$> getDigitallySigned (cParamsVersion cp)
decodeClientKeyXchg :: CurrentParams -> Get Handshake
decodeClientKeyXchg cp =
-- case ClientKeyXchg <$> (remaining >>= getBytes)
case cParamsKeyXchgType cp of
Nothing -> error "no client key exchange type"
Just cke -> ClientKeyXchg <$> parseCKE cke
where
parseCKE CipherKeyExchange_RSA = CKX_RSA <$> (remaining >>= getBytes)
parseCKE CipherKeyExchange_DHE_RSA = parseClientDHPublic
parseCKE CipherKeyExchange_DHE_DSA = parseClientDHPublic
parseCKE CipherKeyExchange_DH_Anon = parseClientDHPublic
parseCKE CipherKeyExchange_ECDHE_RSA = parseClientECDHPublic
parseCKE CipherKeyExchange_ECDHE_ECDSA = parseClientECDHPublic
parseCKE _ = error "unsupported client key exchange type"
parseClientDHPublic = CKX_DH . dhPublic <$> getInteger16
parseClientECDHPublic = CKX_ECDH <$> getOpaque8
decodeServerKeyXchg_DH :: Get ServerDHParams
decodeServerKeyXchg_DH = getServerDHParams
-- We don't support ECDH_Anon at this moment
-- decodeServerKeyXchg_ECDH :: Get ServerECDHParams
decodeServerKeyXchg_RSA :: Get ServerRSAParams
decodeServerKeyXchg_RSA =
ServerRSAParams
<$> getInteger16 -- modulus
<*> getInteger16 -- exponent
decodeServerKeyXchgAlgorithmData
:: Version
-> CipherKeyExchangeType
-> Get ServerKeyXchgAlgorithmData
decodeServerKeyXchgAlgorithmData ver cke = toCKE
where
toCKE = case cke of
CipherKeyExchange_RSA -> SKX_RSA . Just <$> decodeServerKeyXchg_RSA
CipherKeyExchange_DH_Anon -> SKX_DH_Anon <$> decodeServerKeyXchg_DH
CipherKeyExchange_DHE_RSA -> do
dhparams <- getServerDHParams
signature <- getDigitallySigned ver
return $ SKX_DHE_RSA dhparams signature
CipherKeyExchange_DHE_DSA -> do
dhparams <- getServerDHParams
signature <- getDigitallySigned ver
return $ SKX_DHE_DSA dhparams signature
CipherKeyExchange_ECDHE_RSA -> do
ecdhparams <- getServerECDHParams
signature <- getDigitallySigned ver
return $ SKX_ECDHE_RSA ecdhparams signature
CipherKeyExchange_ECDHE_ECDSA -> do
ecdhparams <- getServerECDHParams
signature <- getDigitallySigned ver
return $ SKX_ECDHE_ECDSA ecdhparams signature
_ -> do
bs <- remaining >>= getBytes
return $ SKX_Unknown bs
decodeServerKeyXchg :: CurrentParams -> Get Handshake
decodeServerKeyXchg cp =
case cParamsKeyXchgType cp of
Just cke -> ServerKeyXchg <$> decodeServerKeyXchgAlgorithmData (cParamsVersion cp) cke
Nothing -> ServerKeyXchg . SKX_Unparsed <$> (remaining >>= getBytes)
encodeHandshake :: Handshake -> ByteString
encodeHandshake o =
let content = encodeHandshake' o
in let len = B.length content
in let header = runPut $ encodeHandshakeHeader (typeOfHandshake o) len
in B.concat [header, content]
encodeHandshakeHeader :: HandshakeType -> Int -> Put
encodeHandshakeHeader ty len = putWord8 (fromHandshakeType ty) >> putWord24 len
encodeHandshake' :: Handshake -> ByteString
encodeHandshake' (ClientHello version random compressionIDs CH{..}) = runPut $ do
putBinaryVersion version
putClientRandom32 random
putSession chSession
putWords16 chCiphers
putWords8 compressionIDs
putExtensions chExtensions
return ()
encodeHandshake' (ServerHello version random session cipherid compressionID exts) = runPut $ do
putBinaryVersion version
putServerRandom32 random
putSession session
putWord16 cipherid
putWord8 compressionID
putExtensions exts
return ()
encodeHandshake' (Certificate cc) = encodeCertificate cc
encodeHandshake' (ClientKeyXchg ckx) = runPut $ do
case ckx of
CKX_RSA encryptedPreMain -> putBytes encryptedPreMain
CKX_DH clientDHPublic -> putInteger16 $ dhUnwrapPublic clientDHPublic
CKX_ECDH bytes -> putOpaque8 bytes
encodeHandshake' (ServerKeyXchg skg) = runPut $
case skg of
SKX_RSA _ -> error "encodeHandshake' SKX_RSA not implemented"
SKX_DH_Anon params -> putServerDHParams params
SKX_DHE_RSA params sig -> putServerDHParams params >> putDigitallySigned sig
SKX_DHE_DSA params sig -> putServerDHParams params >> putDigitallySigned sig
SKX_ECDHE_RSA params sig -> putServerECDHParams params >> putDigitallySigned sig
SKX_ECDHE_ECDSA params sig -> putServerECDHParams params >> putDigitallySigned sig
SKX_Unparsed bytes -> putBytes bytes
_ ->
error ("encodeHandshake': cannot handle: " ++ show skg)
encodeHandshake' HelloRequest = ""
encodeHandshake' ServerHelloDone = ""
encodeHandshake' (CertRequest certTypes sigAlgs certAuthorities) = runPut $ do
putWords8 (map fromCertificateType certTypes)
putWords16 $
map
( \(HashAlgorithm x, SignatureAlgorithm y) -> fromIntegral x * 256 + fromIntegral y
)
sigAlgs
putDNames certAuthorities
encodeHandshake' (CertVerify digitallySigned) = runPut $ putDigitallySigned digitallySigned
encodeHandshake' (Finished opaque) = runPut $ putBytes opaque
encodeHandshake' (NewSessionTicket life ticket) = runPut $ do
putWord32 life
putOpaque16 ticket
------------------------------------------------------------
-- | Encode a list of distinguished names.
putDNames :: [DistinguishedName] -> Put
putDNames dnames = do
enc <- mapM encodeCA dnames
let totLength = sum $ map ((+) 2 . B.length) enc
putWord16 (fromIntegral totLength)
mapM_ (\b -> putWord16 (fromIntegral (B.length b)) >> putBytes b) enc
where
-- Convert a distinguished name to its DER encoding.
encodeCA dn = return $ encodeASN1Object dn
{- FIXME make sure it return error if not 32 available -}
getRandom32 :: Get ByteString
getRandom32 = getBytes 32
getServerRandom32 :: Get ServerRandom
getServerRandom32 = ServerRandom <$> getRandom32
getClientRandom32 :: Get ClientRandom
getClientRandom32 = ClientRandom <$> getRandom32
putRandom32 :: ByteString -> Put
putRandom32 = putBytes
putClientRandom32 :: ClientRandom -> Put
putClientRandom32 (ClientRandom r) = putRandom32 r
putServerRandom32 :: ServerRandom -> Put
putServerRandom32 (ServerRandom r) = putRandom32 r
getSession :: Get Session
getSession = do
len8 <- getWord8
case fromIntegral len8 of
0 -> return $ Session Nothing
len -> Session . Just <$> getBytes len
putSession :: Session -> Put
putSession (Session Nothing) = putWord8 0
putSession (Session (Just s)) = putOpaque8 s
getExtensions :: Int -> Get [ExtensionRaw]
getExtensions 0 = return []
getExtensions len = do
extty <- ExtensionID <$> getWord16
extdatalen <- getWord16
extdata <- getBytes $ fromIntegral extdatalen
extxs <- getExtensions (len - fromIntegral extdatalen - 4)
return $ ExtensionRaw extty extdata : extxs
putExtension :: ExtensionRaw -> Put
putExtension (ExtensionRaw (ExtensionID ty) l) = putWord16 ty >> putOpaque16 l
putExtensions :: [ExtensionRaw] -> Put
putExtensions [] = return ()
putExtensions es = putOpaque16 (runPut $ mapM_ putExtension es)
getSignatureHashAlgorithm :: Get HashAndSignatureAlgorithm
getSignatureHashAlgorithm = do
h <- HashAlgorithm <$> getWord8
s <- SignatureAlgorithm <$> getWord8
return (h, s)
putSignatureHashAlgorithm :: HashAndSignatureAlgorithm -> Put
putSignatureHashAlgorithm (HashAlgorithm h, SignatureAlgorithm s) =
putWord8 h >> putWord8 s
getServerDHParams :: Get ServerDHParams
getServerDHParams = ServerDHParams <$> getBigNum16 <*> getBigNum16 <*> getBigNum16
putServerDHParams :: ServerDHParams -> Put
putServerDHParams (ServerDHParams p g y) = mapM_ putBigNum16 [p, g, y]
-- RFC 4492 Section 5.4 Server Key Exchange
getServerECDHParams :: Get ServerECDHParams
getServerECDHParams = do
curveType <- getWord8
case curveType of
3 -> do
-- ECParameters ECCurveType: curve name type
grp <- Group <$> getWord16 -- ECParameters NamedCurve
mxy <- getOpaque8 -- ECPoint
case decodeGroupPublic grp mxy of
Left e -> error $ "getServerECDHParams: " ++ show e
Right grppub -> return $ ServerECDHParams grp grppub
_ ->
error "getServerECDHParams: unknown type for ECDH Params"
-- RFC 4492 Section 5.4 Server Key Exchange
putServerECDHParams :: ServerECDHParams -> Put
putServerECDHParams (ServerECDHParams (Group grp) grppub) = do
putWord8 3 -- ECParameters ECCurveType
putWord16 grp -- ECParameters NamedCurve
putOpaque8 $ encodeGroupPublic grppub -- ECPoint
getDigitallySigned :: Version -> Get DigitallySigned
getDigitallySigned _ver =
DigitallySigned
<$> getSignatureHashAlgorithm
<*> getOpaque16
putDigitallySigned :: DigitallySigned -> Put
putDigitallySigned (DigitallySigned h sig) =
putSignatureHashAlgorithm h >> putOpaque16 sig
{-
- decode and encode ALERT
-}
decodeChangeCipherSpec :: ByteString -> Either TLSError ()
decodeChangeCipherSpec = runGetErr "changecipherspec" $ do
x <- getWord8
when (x /= 1) (fail "unknown change cipher spec content")
encodeChangeCipherSpec :: ByteString
encodeChangeCipherSpec = runPut (putWord8 1)
-- RSA pre-main secret
decodePreMainSecret :: ByteString -> Either TLSError (Version, ByteString)
decodePreMainSecret =
runGetErr "pre-main-secret" $
(,) <$> getBinaryVersion <*> getBytes 46
encodePreMainSecret :: Version -> ByteString -> ByteString
encodePreMainSecret version bytes = runPut (putBinaryVersion version >> putBytes bytes)
-- | in certain cases, we haven't manage to decode ServerKeyExchange properly,
-- because the decoding was too eager and the cipher wasn't been set yet.
-- we keep the Server Key Exchange in it unparsed format, and this function is
-- able to really decode the server key xchange if it's unparsed.
decodeReallyServerKeyXchgAlgorithmData
:: Version
-> CipherKeyExchangeType
-> ByteString
-> Either TLSError ServerKeyXchgAlgorithmData
decodeReallyServerKeyXchgAlgorithmData ver cke =
runGetErr
"server-key-xchg-algorithm-data"
(decodeServerKeyXchgAlgorithmData ver cke)
{-
- generate things for packet content
-}
type PRF = ByteString -> ByteString -> Int -> ByteString
-- | The TLS12 PRF is cipher specific, and some TLS12 algorithms use SHA384
-- instead of the default SHA256.
getPRF :: Version -> Cipher -> PRF
getPRF ver ciph
| ver < TLS12 = prf_MD5SHA1
| maybe True (< TLS12) (cipherMinVer ciph) = prf_SHA256
| otherwise = prf_TLS ver $ fromMaybe SHA256 $ cipherPRFHash ciph
generateMainSecret_TLS
:: ByteArrayAccess preMain
=> PRF
-> preMain
-> ClientRandom
-> ServerRandom
-> ByteString
generateMainSecret_TLS prf preMainSecret (ClientRandom c) (ServerRandom s) =
prf (B.convert preMainSecret) seed 48
where
seed = B.concat ["master secret", c, s]
generateMainSecret
:: ByteArrayAccess preMain
=> Version
-> Cipher
-> preMain
-> ClientRandom
-> ServerRandom
-> ByteString
generateMainSecret v c = generateMainSecret_TLS $ getPRF v c
generateExtendedMainSecret
:: ByteArrayAccess preMain
=> Version
-> Cipher
-> preMain
-> ByteString
-> ByteString
generateExtendedMainSecret v c preMainSecret sessionHash =
getPRF v c (B.convert preMainSecret) seed 48
where
seed = B.append "extended master secret" sessionHash
generateKeyBlock_TLS
:: PRF -> ClientRandom -> ServerRandom -> ByteString -> Int -> ByteString
generateKeyBlock_TLS prf (ClientRandom c) (ServerRandom s) mainSecret kbsize =
prf mainSecret seed kbsize
where
seed = B.concat ["key expansion", s, c]
generateKeyBlock
:: Version
-> Cipher
-> ClientRandom
-> ServerRandom
-> ByteString
-> Int
-> ByteString
generateKeyBlock v c = generateKeyBlock_TLS $ getPRF v c
generateFinished_TLS :: PRF -> ByteString -> ByteString -> HashCtx -> ByteString
generateFinished_TLS prf label mainSecret hashctx = prf mainSecret seed 12
where
seed = B.concat [label, hashFinal hashctx]
generateClientFinished
:: Version
-> Cipher
-> ByteString
-> HashCtx
-> ByteString
generateClientFinished ver ciph =
generateFinished_TLS (getPRF ver ciph) "client finished"
generateServerFinished
:: Version
-> Cipher
-> ByteString
-> HashCtx
-> ByteString
generateServerFinished ver ciph =
generateFinished_TLS (getPRF ver ciph) "server finished"
encodeSignedDHParams
:: ServerDHParams -> ClientRandom -> ServerRandom -> ByteString
encodeSignedDHParams dhparams cran sran =
runPut $
putClientRandom32 cran >> putServerRandom32 sran >> putServerDHParams dhparams
-- Combination of RFC 5246 and 4492 is ambiguous.
-- Let's assume ecdhe_rsa and ecdhe_dss are identical to
-- dhe_rsa and dhe_dss.
encodeSignedECDHParams
:: ServerECDHParams -> ClientRandom -> ServerRandom -> ByteString
encodeSignedECDHParams dhparams cran sran =
runPut $
putClientRandom32 cran >> putServerRandom32 sran >> putServerECDHParams dhparams
encodeCertificate :: CertificateChain -> ByteString
encodeCertificate cc = runPut $ putOpaque24 (runPut $ mapM_ putOpaque24 certs)
where
(CertificateChainRaw certs) = encodeCertificateChain cc