    -- |
    -- Module      : Crypto.Hash.Blake2b
    -- License     : BSD-style
    -- Maintainer  : Vincent Hanquez <vincent@snarc.org>
    -- Stability   : experimental
    -- Portability : unknown
    --
    -- module containing the binding functions to work with the
    -- Blake2b cryptographic hash.
    --
    {-# LANGUAGE ForeignFunctionInterface #-}
    {-# LANGUAGE DeriveDataTypeable #-}
    module Crypto.Hash.Blake2b
        (  Blake2b_160 (..), Blake2b_224 (..), Blake2b_256 (..), Blake2b_384 (..), Blake2b_512 (..)
        ) where

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

    -- | Blake2b (160 bits) cryptographic hash algorithm
    data Blake2b_160 = Blake2b_160
        deriving (Show,Data,Typeable)

    instance HashAlgorithm Blake2b_160 where
        hashBlockSize  _          = 128
        hashDigestSize _          = 20
        hashInternalContextSize _ = 361
        hashInternalInit p        = c_blake2b_init p 160
        hashInternalUpdate        = c_blake2b_update
        hashInternalFinalize p    = c_blake2b_finalize p 160

    -- | Blake2b (224 bits) cryptographic hash algorithm
    data Blake2b_224 = Blake2b_224
        deriving (Show,Data,Typeable)

    instance HashAlgorithm Blake2b_224 where
        hashBlockSize  _          = 128
        hashDigestSize _          = 28
        hashInternalContextSize _ = 361
        hashInternalInit p        = c_blake2b_init p 224
        hashInternalUpdate        = c_blake2b_update
        hashInternalFinalize p    = c_blake2b_finalize p 224

    -- | Blake2b (256 bits) cryptographic hash algorithm
    data Blake2b_256 = Blake2b_256
        deriving (Show,Data,Typeable)

    instance HashAlgorithm Blake2b_256 where
        hashBlockSize  _          = 128
        hashDigestSize _          = 32
        hashInternalContextSize _ = 361
        hashInternalInit p        = c_blake2b_init p 256
        hashInternalUpdate        = c_blake2b_update
        hashInternalFinalize p    = c_blake2b_finalize p 256

    -- | Blake2b (384 bits) cryptographic hash algorithm
    data Blake2b_384 = Blake2b_384
        deriving (Show,Data,Typeable)

    instance HashAlgorithm Blake2b_384 where
        hashBlockSize  _          = 128
        hashDigestSize _          = 48
        hashInternalContextSize _ = 361
        hashInternalInit p        = c_blake2b_init p 384
        hashInternalUpdate        = c_blake2b_update
        hashInternalFinalize p    = c_blake2b_finalize p 384

    -- | Blake2b (512 bits) cryptographic hash algorithm
    data Blake2b_512 = Blake2b_512
        deriving (Show,Data,Typeable)

    instance HashAlgorithm Blake2b_512 where
        hashBlockSize  _          = 128
        hashDigestSize _          = 64
        hashInternalContextSize _ = 361
        hashInternalInit p        = c_blake2b_init p 512
        hashInternalUpdate        = c_blake2b_update
        hashInternalFinalize p    = c_blake2b_finalize p 512

    foreign import ccall unsafe "cryptonite_blake2b_init"
        c_blake2b_init :: Ptr (Context a) -> Word32 -> IO ()

    foreign import ccall "cryptonite_blake2b_update"
        c_blake2b_update :: Ptr (Context a) -> Ptr Word8 -> Word32 -> IO ()

    foreign import ccall unsafe "cryptonite_blake2b_finalize"
        c_blake2b_finalize :: Ptr (Context a) -> Word32 -> Ptr (Digest a) -> IO ()