cryptonite/Crypto/Hash/Internal/MD5.hs

102 lines
3.0 KiB
Haskell

{-# LANGUAGE ForeignFunctionInterface, CPP, MultiParamTypeClasses #-}
-- |
-- Module : Crypto.Hash.Internal.MD5
-- License : BSD-style
-- Maintainer : Vincent Hanquez <vincent@snarc.org>
-- Stability : experimental
-- Portability : unknown
--
-- A module containing MD5 bindings
--
module Crypto.Hash.Internal.MD5
( Ctx(..)
-- * Internal values
, digestSize
, sizeCtx
-- * Internal IO hash functions
, internalInit
, internalInitAt
, internalUpdate
, internalFinalize
-- * Context copy and creation
, withCtxCopy
, withCtxNewThrow
, withCtxThrow
) where
import Foreign.Ptr
import Foreign.ForeignPtr (withForeignPtr)
import Foreign.Storable
import Foreign.Marshal.Alloc
import Data.ByteString (ByteString)
import Data.ByteString.Unsafe (unsafeUseAsCStringLen)
import Data.ByteString.Internal (create, toForeignPtr)
import Data.Word
newtype Ctx = Ctx ByteString
{-# INLINE digestSize #-}
digestSize :: Int
digestSize = 16
{-# INLINE sizeCtx #-}
sizeCtx :: Int
sizeCtx = 96
{-# INLINE withByteStringPtr #-}
withByteStringPtr :: ByteString -> (Ptr Word8 -> IO a) -> IO a
withByteStringPtr b f =
withForeignPtr fptr $ \ptr -> f (ptr `plusPtr` off)
where (fptr, off, _) = toForeignPtr b
{-# INLINE memcopy64 #-}
memcopy64 :: Ptr Word64 -> Ptr Word64 -> IO ()
memcopy64 dst src = mapM_ peekAndPoke [0..(12-1)]
where peekAndPoke i = peekElemOff src i >>= pokeElemOff dst i
withCtxCopy :: Ctx -> (Ptr Ctx -> IO ()) -> IO Ctx
withCtxCopy (Ctx ctxB) f = Ctx `fmap` createCtx
where createCtx = create sizeCtx $ \dstPtr ->
withByteStringPtr ctxB $ \srcPtr -> do
memcopy64 (castPtr dstPtr) (castPtr srcPtr)
f (castPtr dstPtr)
withCtxThrow :: Ctx -> (Ptr Ctx -> IO a) -> IO a
withCtxThrow (Ctx ctxB) f =
allocaBytes sizeCtx $ \dstPtr ->
withByteStringPtr ctxB $ \srcPtr -> do
memcopy64 (castPtr dstPtr) (castPtr srcPtr)
f (castPtr dstPtr)
withCtxNew :: (Ptr Ctx -> IO ()) -> IO Ctx
withCtxNew f = Ctx `fmap` create sizeCtx (f . castPtr)
withCtxNewThrow :: (Ptr Ctx -> IO a) -> IO a
withCtxNewThrow f = allocaBytes sizeCtx (f . castPtr)
foreign import ccall unsafe "cryptonite_md5.h cryptonite_md5_init"
c_md5_init :: Ptr Ctx -> IO ()
foreign import ccall "cryptonite_md5.h cryptonite_md5_update"
c_md5_update :: Ptr Ctx -> Ptr Word8 -> Word32 -> IO ()
foreign import ccall unsafe "cryptonite_md5.h cryptonite_md5_finalize"
c_md5_finalize :: Ptr Ctx -> Ptr Word8 -> IO ()
internalInitAt :: Ptr Ctx -> IO ()
internalInitAt = c_md5_init
-- | init a context
internalInit :: IO Ctx
internalInit = withCtxNew internalInitAt
-- | Update a context in place
internalUpdate :: Ptr Ctx -> ByteString -> IO ()
internalUpdate ptr d =
unsafeUseAsCStringLen d (\(cs, len) -> c_md5_update ptr (castPtr cs) (fromIntegral len))
-- | Finalize a context in place
internalFinalize :: Ptr Ctx -> IO ByteString
internalFinalize ptr = create digestSize (c_md5_finalize ptr)