cryptonite/Crypto/PubKey/Ed448.hs
2016-04-18 13:25:11 -07:00

103 lines
3.5 KiB
Haskell

-- |
-- Module : Crypto.PubKey.Ed448
-- License : BSD-style
-- Maintainer : John Galt <jgalt@centromere.net>
-- Stability : experimental
-- Portability : unknown
--
-- Ed448 support
--
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE MagicHash #-}
module Crypto.PubKey.Ed448
( SecretKey
, PublicKey
, DhSecret
-- * Smart constructors
, dhSecret
, publicKey
, secretKey
-- * methods
, dh
, toPublic
) where
import Data.Word
import Foreign.Ptr
import GHC.Ptr
import Crypto.Error
import Crypto.Internal.Compat
import Crypto.Internal.Imports
import Crypto.Internal.ByteArray (ByteArrayAccess, ScrubbedBytes, Bytes, withByteArray)
import qualified Crypto.Internal.ByteArray as B
-- | A Ed448 Secret key
newtype SecretKey = SecretKey ScrubbedBytes
deriving (Show,Eq,ByteArrayAccess,NFData)
-- | A Ed448 public key
newtype PublicKey = PublicKey Bytes
deriving (Show,Eq,ByteArrayAccess,NFData)
-- | A Ed448 Diffie Hellman secret related to a
-- public key and a secret key.
newtype DhSecret = DhSecret ScrubbedBytes
deriving (Show,Eq,ByteArrayAccess,NFData)
-- | Try to build a public key from a bytearray
publicKey :: ByteArrayAccess bs => bs -> CryptoFailable PublicKey
publicKey bs
| B.length bs == x448_bytes = CryptoPassed $ PublicKey $ B.copyAndFreeze bs (\_ -> return ())
| otherwise = CryptoFailed CryptoError_PublicKeySizeInvalid
-- | Try to build a secret key from a bytearray
secretKey :: ByteArrayAccess bs => bs -> CryptoFailable SecretKey
secretKey bs
| B.length bs == x448_bytes = unsafeDoIO $
withByteArray bs $ \inp -> do
valid <- isValidPtr inp
if valid
then (CryptoPassed . SecretKey) <$> B.copy bs (\_ -> return ())
else return $ CryptoFailed CryptoError_SecretKeyStructureInvalid
| otherwise = CryptoFailed CryptoError_SecretKeySizeInvalid
where
isValidPtr :: Ptr Word8 -> IO Bool
isValidPtr _ =
return True
{-# NOINLINE secretKey #-}
-- | Create a DhSecret from a bytearray object
dhSecret :: ByteArrayAccess b => b -> CryptoFailable DhSecret
dhSecret bs
| B.length bs == x448_bytes = CryptoPassed $ DhSecret $ B.copyAndFreeze bs (\_ -> return ())
| otherwise = CryptoFailed CryptoError_SharedSecretSizeInvalid
-- | Compute the Diffie Hellman secret from a public key and a secret key
dh :: PublicKey -> SecretKey -> DhSecret
dh (PublicKey pub) (SecretKey sec) = DhSecret <$>
B.allocAndFreeze x448_bytes $ \result ->
withByteArray sec $ \psec ->
withByteArray pub $ \ppub ->
ccryptonite_ed448 result psec ppub
{-# NOINLINE dh #-}
-- | Create a public key from a secret key
toPublic :: SecretKey -> PublicKey
toPublic (SecretKey sec) = PublicKey <$>
B.allocAndFreeze x448_bytes $ \result ->
withByteArray sec $ \psec ->
ccryptonite_ed448 result psec basePoint
where
basePoint = Ptr "\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"#
{-# NOINLINE toPublic #-}
x448_bytes :: Int
x448_bytes = 448 `quot` 8
foreign import ccall "cryptonite_x448"
ccryptonite_ed448 :: Ptr Word8 -- ^ public
-> Ptr Word8 -- ^ secret
-> Ptr Word8 -- ^ basepoint
-> IO ()