hs-tls/core/Network/TLS/Sending.hs
2013-07-28 09:19:28 +01:00

73 lines
2.8 KiB
Haskell

-- |
-- Module : Network.TLS.Sending
-- License : BSD-style
-- Maintainer : Vincent Hanquez <vincent@snarc.org>
-- Stability : experimental
-- Portability : unknown
--
-- the Sending module contains calls related to marshalling packets according
-- to the TLS state
--
module Network.TLS.Sending (writePacket) where
import Control.Monad.State
import Data.ByteString (ByteString)
import qualified Data.ByteString as B
import Network.TLS.Types (Role(..))
import Network.TLS.Cap
import Network.TLS.Struct
import Network.TLS.Record
import Network.TLS.Packet
import Network.TLS.State
import Network.TLS.Handshake.State
import Network.TLS.Cipher
-- | 'makePacketData' create a Header and a content bytestring related to a packet
-- this doesn't change any state
makeRecord :: Packet -> RecordM (Record Plaintext)
makeRecord pkt = do
ver <- getRecordVersion
return $ Record (packetType pkt) ver (fragmentPlaintext $ writePacketContent pkt)
where writePacketContent (Handshake hss) = encodeHandshakes hss
writePacketContent (Alert a) = encodeAlerts a
writePacketContent (ChangeCipherSpec) = encodeChangeCipherSpec
writePacketContent (AppData x) = x
-- | marshall packet data
encodeRecord :: Record Ciphertext -> RecordM ByteString
encodeRecord record = return $ B.concat [ encodeHeader hdr, content ]
where (hdr, content) = recordToRaw record
-- | writePacket transform a packet into marshalled data related to current state
-- and updating state on the go
writePacket :: Packet -> TLSSt ByteString
writePacket pkt@(Handshake hss) = do
forM_ hss $ \hs -> do
case hs of
Finished fdata -> updateVerifiedData ClientRole fdata
_ -> return ()
let encoded = encodeHandshake hs
when (certVerifyHandshakeMaterial hs) $ withHandshakeM $ addHandshakeMessage encoded
when (finishHandshakeTypeMaterial $ typeOfHandshake hs) $ withHandshakeM $ updateHandshakeDigest encoded
prepareRecord (makeRecord pkt >>= engageRecord >>= encodeRecord)
writePacket pkt = do
d <- prepareRecord (makeRecord pkt >>= engageRecord >>= encodeRecord)
when (pkt == ChangeCipherSpec) $ switchTxEncryption
return d
-- before TLS 1.1, the block cipher IV is made of the residual of the previous block,
-- so we use cstIV as is, however in other case we generate an explicit IV
prepareRecord :: RecordM a -> TLSSt a
prepareRecord f = do
st <- get
ver <- getVersion
let sz = case stCipher $ stTxState st of
Nothing -> 0
Just cipher -> bulkIVSize $ cipherBulk cipher
if hasExplicitBlockIV ver && sz > 0
then do newIV <- genRandom sz
runTxState (modify $ setRecordIV newIV)
runTxState f
else runTxState f