Implementation.hsig

{-# LANGUAGE ConstraintKinds             #-}
{-# LANGUAGE DataKinds                   #-}
{-# LANGUAGE KindSignatures              #-}
{-# LANGUAGE MultiParamTypeClasses       #-}
{-# LANGUAGE FlexibleInstances           #-}
{-# LANGUAGE TypeFamilies                #-}
{-# LANGUAGE CPP                         #-}

-- | An implementation for chacha20 together with hchacha20 hash
-- implementation.
signature Implementation where


import Raaz.Core
import Raaz.Primitive.ChaCha20.Internal

-- NOTE:
--
-- With https://gitlab.haskell.org/ghc/ghc/issues/15138 and
-- https://gitlab.haskell.org/ghc/ghc/issues/15379 fixed I (ppk) had
-- expected that one can differ the assignment of Buffer
-- alignment. While this is indeed the case for other implementations,
-- for some reason it, does not seem to work for the Mac
-- implementation, probably because of being an indirect constraint;
-- Mac.Implementation -> Implementation but then is mixed as
-- Implementation in the auth case. Therefore, I am setting an
-- artificially large base number here.
--
# if MIN_VERSION_base(100,100,0)
-- # if MIN_VERSION_base(4,13,0)
import GHC.TypeLits

-- | The alignment requirements on the buffer.
data BufferAlignment :: Nat
instance KnownNat BufferAlignment

# else
-- | The alignment required for buffer (hack around bug
-- https://ghc.haskell.org/trac/ghc/ticket/15138)
type BufferAlignment = 32
#endif

-- | The primitive for which the implementation is given

type Prim = ChaCha20
data Internals
instance Memory Internals

instance Initialisable Internals (BlockCount ChaCha20)
instance Extractable   Internals (BlockCount ChaCha20)

-- | The function that sets the internal state for the xchacha
-- variant.
xchacha20Setup :: Nounce XChaCha20 -> Internals -> IO ()

-- | Allows copying key from a Memory cell to internal.
copyKey :: Dest Internals-> Src (MemoryCell (Key ChaCha20)) -> IO ()