    -- |
    -- Module      : Crypto.Hash.Blake2s
    -- License     : BSD-style
    -- Maintainer  : Vincent Hanquez <vincent@snarc.org>
    -- Stability   : experimental
    -- Portability : unknown
    --
    -- Module containing the binding functions to work with the
    -- Blake2s cryptographic hash.
    --
    {-# LANGUAGE ForeignFunctionInterface #-}
    {-# LANGUAGE DeriveDataTypeable #-}
    {-# LANGUAGE DataKinds #-}
    {-# LANGUAGE TypeFamilies #-}
    module Crypto.Hash.Blake2s
        (  Blake2s_160 (..), Blake2s_224 (..), Blake2s_256 (..)
        ) where

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

    -- | Blake2s (160 bits) cryptographic hash algorithm
    data Blake2s_160 = Blake2s_160
        deriving (Show,Data,Typeable)

    instance HashAlgorithm Blake2s_160 where
        type HashBlockSize           Blake2s_160 = 64
        type HashDigestSize          Blake2s_160 = 20
        type HashInternalContextSize Blake2s_160 = 136
        hashBlockSize  _          = 64
        hashDigestSize _          = 20
        hashInternalContextSize _ = 136
        hashInternalInit p        = c_blake2s_init p 160
        hashInternalUpdate        = c_blake2s_update
        hashInternalFinalize p    = c_blake2s_finalize p 160

    -- | Blake2s (224 bits) cryptographic hash algorithm
    data Blake2s_224 = Blake2s_224
        deriving (Show,Data,Typeable)

    instance HashAlgorithm Blake2s_224 where
        type HashBlockSize           Blake2s_224 = 64
        type HashDigestSize          Blake2s_224 = 28
        type HashInternalContextSize Blake2s_224 = 136
        hashBlockSize  _          = 64
        hashDigestSize _          = 28
        hashInternalContextSize _ = 136
        hashInternalInit p        = c_blake2s_init p 224
        hashInternalUpdate        = c_blake2s_update
        hashInternalFinalize p    = c_blake2s_finalize p 224

    -- | Blake2s (256 bits) cryptographic hash algorithm
    data Blake2s_256 = Blake2s_256
        deriving (Show,Data,Typeable)

    instance HashAlgorithm Blake2s_256 where
        type HashBlockSize           Blake2s_256 = 64
        type HashDigestSize          Blake2s_256 = 32
        type HashInternalContextSize Blake2s_256 = 136
        hashBlockSize  _          = 64
        hashDigestSize _          = 32
        hashInternalContextSize _ = 136
        hashInternalInit p        = c_blake2s_init p 256
        hashInternalUpdate        = c_blake2s_update
        hashInternalFinalize p    = c_blake2s_finalize p 256

    foreign import ccall unsafe "cryptonite_blake2s_init"
        c_blake2s_init :: Ptr (Context a) -> Word32 -> IO ()

    foreign import ccall "cryptonite_blake2s_update"
        c_blake2s_update :: Ptr (Context a) -> Ptr Word8 -> Word32 -> IO ()

    foreign import ccall unsafe "cryptonite_blake2s_finalize"
        c_blake2s_finalize :: Ptr (Context a) -> Word32 -> Ptr (Digest a) -> IO ()