module Network.TLS.Record.Engage
( engageRecord
) where
import Control.Monad.State
import Network.TLS.Cap
import Network.TLS.Record.State
import Network.TLS.Record.Types
import Network.TLS.Cipher
import Network.TLS.Compression
import Network.TLS.Util
import Data.ByteString (ByteString)
import qualified Data.ByteString as B
engageRecord :: Record Plaintext -> RecordM (Record Ciphertext)
engageRecord = compressRecord >=> encryptRecord
compressRecord :: Record Plaintext -> RecordM (Record Compressed)
compressRecord record =
onRecordFragment record $ fragmentCompress $ \bytes -> do
withCompression $ compressionDeflate bytes
encryptRecord :: Record Compressed -> RecordM (Record Ciphertext)
encryptRecord record = onRecordFragment record $ fragmentCipher $ \bytes -> do
st <- get
case stCipher st of
Nothing -> return bytes
_ -> encryptContent record bytes
encryptContent :: Record Compressed -> ByteString -> RecordM ByteString
encryptContent record content = do
digest <- makeDigest (recordToHeader record) content
encryptData $ B.concat [content, digest]
encryptData :: ByteString -> RecordM ByteString
encryptData content = do
tstate <- get
ver <- getRecordVersion
let cipher = fromJust "cipher" $ stCipher tstate
let bulk = cipherBulk cipher
let cst = stCryptState tstate
let writekey = cstKey cst
case bulkF bulk of
BulkBlockF encrypt _ -> do
let blockSize = fromIntegral $ bulkBlockSize bulk
let msg_len = B.length content
let padding = if blockSize > 0
then
let padbyte = blockSize (msg_len `mod` blockSize) in
let padbyte' = if padbyte == 0 then blockSize else padbyte in
B.replicate padbyte' (fromIntegral (padbyte' 1))
else
B.empty
let e = encrypt writekey (cstIV cst) (B.concat [ content, padding ])
if hasExplicitBlockIV ver
then return $ B.concat [cstIV cst,e]
else do
let newiv = fromJust "new iv" $ takelast (bulkIVSize bulk) e
put $ tstate { stCryptState = cst { cstIV = newiv } }
return e
BulkStreamF initF encryptF _ -> do
let iv = cstIV cst
let (e, newiv) = encryptF (if iv /= B.empty then iv else initF writekey) content
put $ tstate { stCryptState = cst { cstIV = newiv } }
return e