112 lines
3.7 KiB
Haskell
112 lines
3.7 KiB
Haskell
-- |
|
|
-- Module : Crypto.PubKey.Curve25519
|
|
-- License : BSD-style
|
|
-- Maintainer : Vincent Hanquez <vincent@snarc.org>
|
|
-- Stability : experimental
|
|
-- Portability : unknown
|
|
--
|
|
-- Curve25519 support
|
|
--
|
|
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
|
|
{-# LANGUAGE MagicHash #-}
|
|
module Crypto.PubKey.Curve25519
|
|
( SecretKey
|
|
, PublicKey
|
|
, DhSecret
|
|
-- * Smart constructors
|
|
, dhSecret
|
|
, publicKey
|
|
, secretKey
|
|
-- * methods
|
|
, dh
|
|
, toPublic
|
|
) where
|
|
|
|
import Data.Word
|
|
import Foreign.Ptr
|
|
import GHC.Ptr
|
|
|
|
import Crypto.Internal.Compat
|
|
import Crypto.Internal.Imports
|
|
import Crypto.Internal.ByteArray (ByteArrayAccess, ScrubbedBytes, Bytes, withByteArray)
|
|
import qualified Crypto.Internal.ByteArray as B
|
|
|
|
-- | A Curve25519 Secret key
|
|
newtype SecretKey = SecretKey ScrubbedBytes
|
|
deriving (Show,Eq,ByteArrayAccess)
|
|
|
|
-- | A Curve25519 public key
|
|
newtype PublicKey = PublicKey Bytes
|
|
deriving (Show,Eq,ByteArrayAccess)
|
|
|
|
-- | A Curve25519 Diffie Hellman secret related to a
|
|
-- public key and a secret key.
|
|
newtype DhSecret = DhSecret ScrubbedBytes
|
|
deriving (Show,Eq,ByteArrayAccess)
|
|
|
|
-- | Try to build a public key from a bytearray
|
|
publicKey :: ByteArrayAccess bs => bs -> Either String PublicKey
|
|
publicKey bs
|
|
| B.length bs == 32 = Right $ PublicKey $ B.copyAndFreeze bs (\_ -> return ())
|
|
| otherwise = Left "invalid public key size"
|
|
|
|
-- | Try to build a secret key from a bytearray
|
|
secretKey :: ByteArrayAccess bs => bs -> Either String SecretKey
|
|
secretKey bs
|
|
| B.length bs == 32 = unsafeDoIO $ do
|
|
withByteArray bs $ \inp -> do
|
|
valid <- isValidPtr inp
|
|
if valid
|
|
then (Right . SecretKey) <$> B.copy bs (\_ -> return ())
|
|
else return $ Left "invalid secret key"
|
|
| otherwise = Left "secret key invalid size"
|
|
where
|
|
-- e[0] &= 0xf8;
|
|
-- e[31] &= 0x7f;
|
|
-- e[31] |= 40;
|
|
isValidPtr :: Ptr Word8 -> IO Bool
|
|
isValidPtr _ = do
|
|
--b0 <- peekElemOff inp 0
|
|
--b31 <- peekElemOff inp 31
|
|
return True
|
|
{-
|
|
return $ and [ testBit b0 0 == False
|
|
, testBit b0 1 == False
|
|
, testBit b0 2 == False
|
|
, testBit b31 7 == False
|
|
, testBit b31 6 == True
|
|
]
|
|
-}
|
|
{-# NOINLINE secretKey #-}
|
|
|
|
-- | Create a DhSecret from a bytearray object
|
|
dhSecret :: ByteArrayAccess b => b -> Either String DhSecret
|
|
dhSecret bs
|
|
| B.length bs == 32 = Right $ DhSecret $ B.copyAndFreeze bs (\_ -> return ())
|
|
| otherwise = Left "invalid dh secret size"
|
|
|
|
-- | 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 32 $ \result ->
|
|
withByteArray sec $ \psec ->
|
|
withByteArray pub $ \ppub ->
|
|
ccryptonite_curve25519 result psec ppub
|
|
{-# NOINLINE dh #-}
|
|
|
|
-- | Create a public key from a secret key
|
|
toPublic :: SecretKey -> PublicKey
|
|
toPublic (SecretKey sec) = PublicKey <$>
|
|
B.allocAndFreeze 32 $ \result ->
|
|
withByteArray sec $ \psec ->
|
|
ccryptonite_curve25519 result psec basePoint
|
|
where
|
|
basePoint = Ptr "\x09\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 #-}
|
|
|
|
foreign import ccall "cryptonite_curve25519_donna"
|
|
ccryptonite_curve25519 :: Ptr Word8 -- ^ public
|
|
-> Ptr Word8 -- ^ secret
|
|
-> Ptr Word8 -- ^ basepoint
|
|
-> IO ()
|