cryptonite/Crypto/Random/Entropy/Backend.hs
Vincent Hanquez adca793a9f Reorganize entropy interfaces.
* separate pool into a different module
* only export by default a simple gathering function
* export an unsafe module with all the memory methods
2014-08-25 08:00:10 +01:00

43 lines
1.1 KiB
Haskell

{-# LANGUAGE CPP #-}
{-# LANGUAGE ExistentialQuantification #-}
module Crypto.Random.Entropy.Backend
( EntropyBackend
, supportedBackends
, gatherBackend
) where
import Foreign.Ptr
import Data.Word (Word8)
import Crypto.Random.Entropy.Source
#ifdef SUPPORT_RDRAND
import Crypto.Random.Entropy.RDRand
#endif
#ifdef WINDOWS
import Crypto.Random.Entropy.Windows
#else
import Crypto.Random.Entropy.Unix
#endif
supportedBackends :: [IO (Maybe EntropyBackend)]
supportedBackends =
[
#ifdef SUPPORT_RDRAND
openBackend (undefined :: RDRand),
#endif
#ifdef WINDOWS
openBackend (undefined :: WinCryptoAPI)
#else
openBackend (undefined :: DevRandom), openBackend (undefined :: DevURandom)
#endif
]
data EntropyBackend = forall b . EntropySource b => EntropyBackend b
openBackend :: EntropySource b => b -> IO (Maybe EntropyBackend)
openBackend b = fmap EntropyBackend `fmap` callOpen b
where callOpen :: EntropySource b => b -> IO (Maybe b)
callOpen _ = entropyOpen
gatherBackend :: EntropyBackend -> Ptr Word8 -> Int -> IO Int
gatherBackend (EntropyBackend backend) ptr n = entropyGather backend ptr n