    -- |
    -- Module      : Crypto.Hash.Skein512
    -- License     : BSD-style
    -- Maintainer  : Vincent Hanquez <vincent@snarc.org>
    -- Stability   : experimental
    -- Portability : unknown
    --
    -- module containing the binding functions to work with the
    -- Skein512 cryptographic hash.
    --
    {-# LANGUAGE ForeignFunctionInterface #-}
    module Crypto.Hash.Skein512
        (  Skein512_224 (..), Skein512_256 (..), Skein512_384 (..), Skein512_512 (..)
        ) where

    import           Crypto.Hash.Types
    import           Foreign.Ptr (Ptr)
    import           Data.Word (Word8, Word32)

    -- | Skein512 (224 bits) cryptographic hash algorithm
    data Skein512_224 = Skein512_224
        deriving (Show)

    instance HashAlgorithm Skein512_224 where
        hashBlockSize  _          = 64
        hashDigestSize _          = 28
        hashInternalContextSize _ = 160
        hashInternalInit p        = c_skein512_init p 224
        hashInternalUpdate        = c_skein512_update
        hashInternalFinalize p    = c_skein512_finalize p 224

    -- | Skein512 (256 bits) cryptographic hash algorithm
    data Skein512_256 = Skein512_256
        deriving (Show)

    instance HashAlgorithm Skein512_256 where
        hashBlockSize  _          = 64
        hashDigestSize _          = 32
        hashInternalContextSize _ = 160
        hashInternalInit p        = c_skein512_init p 256
        hashInternalUpdate        = c_skein512_update
        hashInternalFinalize p    = c_skein512_finalize p 256

    -- | Skein512 (384 bits) cryptographic hash algorithm
    data Skein512_384 = Skein512_384
        deriving (Show)

    instance HashAlgorithm Skein512_384 where
        hashBlockSize  _          = 64
        hashDigestSize _          = 48
        hashInternalContextSize _ = 160
        hashInternalInit p        = c_skein512_init p 384
        hashInternalUpdate        = c_skein512_update
        hashInternalFinalize p    = c_skein512_finalize p 384

    -- | Skein512 (512 bits) cryptographic hash algorithm
    data Skein512_512 = Skein512_512
        deriving (Show)

    instance HashAlgorithm Skein512_512 where
        hashBlockSize  _          = 64
        hashDigestSize _          = 64
        hashInternalContextSize _ = 160
        hashInternalInit p        = c_skein512_init p 512
        hashInternalUpdate        = c_skein512_update
        hashInternalFinalize p    = c_skein512_finalize p 512

    foreign import ccall unsafe "cryptonite_skein512_init"
        c_skein512_init :: Ptr (Context a) -> Word32 -> IO ()

    foreign import ccall "cryptonite_skein512_update"
        c_skein512_update :: Ptr (Context a) -> Ptr Word8 -> Word32 -> IO ()

    foreign import ccall unsafe "cryptonite_skein512_finalize"
        c_skein512_finalize :: Ptr (Context a) -> Word32 -> Ptr (Digest a) -> IO ()