module Crypto.Random.Entropy.Unsafe
( replenish
, module Crypto.Random.Entropy.Backend
) where
import Data.Word (Word8)
import Foreign.Ptr (Ptr, plusPtr)
import Crypto.Random.Entropy.Backend
replenish :: Int -> [EntropyBackend] -> Ptr Word8 -> IO ()
replenish _ [] _ = fail "cryptonite: random: cannot get any source of entropy on this system"
replenish poolSize backends ptr = loop 0 backends ptr poolSize
where loop :: Int -> [EntropyBackend] -> Ptr Word8 -> Int -> IO ()
loop retry [] p n | n == 0 = return ()
| retry == 3 = error "cryptonite: random: cannot fully replenish"
| otherwise = loop (retry+1) backends p n
loop _ (_:_) _ 0 = return ()
loop retry (b:bs) p n = do
r <- gatherBackend b p n
loop retry bs (p `plusPtr` r) (n - r)