module Crypto.Noise.Hash.SHA512
(
SHA512
) where
import qualified Crypto.Hash as H
import qualified Crypto.MAC.HMAC as M
import Data.ByteArray (ScrubbedBytes, convert, empty, snoc)
import Data.List (unfoldr)
import Data.Word (Word8)
import Crypto.Noise.Hash
data SHA512
instance Hash SHA512 where
newtype ChainingKey SHA512 = HCKSHA512 ScrubbedBytes
newtype Digest SHA512 = HDSHA512 (H.Digest H.SHA512)
hashName _ = "SHA512"
hashLength _ = 64
hash = hash'
hashHKDF = hkdf
hashBytesToCK = bytesToCK
hashCKToBytes = ckToBytes
hashToBytes = toBytes
hash' :: ScrubbedBytes -> Digest SHA512
hash' bs = HDSHA512 $ H.hash bs
hkdf :: ChainingKey SHA512
-> ScrubbedBytes
-> Word8
-> [ScrubbedBytes]
hkdf (HCKSHA512 ck) keyMat numOutputs = loop (empty, 1)
where
hmac key info = convert (M.hmac key info :: M.HMAC H.SHA512) :: ScrubbedBytes
tempKey = hmac ck keyMat
loop = unfoldr $ \(c, i) -> let r = hmac tempKey (c `snoc` i) in
if i == 0
then Nothing
else if i <= numOutputs
then Just (r, (r, i + 1))
else Nothing
bytesToCK :: ScrubbedBytes -> ChainingKey SHA512
bytesToCK = HCKSHA512
ckToBytes :: ChainingKey SHA512 -> ScrubbedBytes
ckToBytes (HCKSHA512 ck) = ck
toBytes :: Digest SHA512 -> ScrubbedBytes
toBytes (HDSHA512 d) = convert d