add support for curve 25519

Crypto/PubKey/Curve25519.hs

@@ -13,10 +13,13 @@ module Crypto.PubKey.Curve25519
     ( SecretKey
     , PublicKey
     , DhSecret
+    -- * Smart constructors
+    , dhSecret
+    , publicKey
+    , secretKey
     -- * methods
     , dh
     , toPublic
-    , toSecret
     ) where
 
 import           Control.Applicative
@@ -31,57 +34,80 @@ import           Foreign.Storable
 
 import           Crypto.Internal.Compat
 
---  e[0] &= 0xf8;
---  e[31] &= 0x7f;
---  e[31] |= 40;
+-- | A Curve25519 Secret key
 newtype SecretKey = SecretKey SecureMem
     deriving (Show,Eq,Byteable)
 
+-- | A Curve25519 public key
 newtype PublicKey = PublicKey ByteString
     deriving (Show,Eq,Byteable)
 
-newtype DhSecret = DhSecret ByteString
+-- | A Curve25519 Diffie Hellman secret related to a
+-- public key and a secret key.
+newtype DhSecret = DhSecret SecureMem
     deriving (Show,Eq,Byteable)
 
-basePoint :: PublicKey
-basePoint = PublicKey "\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"
+-- | Try to build a public key from a bytearray
+publicKey :: Byteable bs => bs -> Either String PublicKey
+publicKey bs
+    | byteableLength bs == 32 = Right $ PublicKey $ toBytes bs
+    | otherwise               = Left "invalid public key size"
 
-dh :: PublicKey -> SecretKey -> DhSecret
-dh (PublicKey pub) (SecretKey sec) = DhSecret <$>
-    B.unsafeCreate 32    $ \result ->
-    withSecureMemPtr sec $ \psec   ->
-    withBytePtr pub      $ \ppub   ->
-        ccryptonite_curve25519 result psec ppub
-
-toPublic :: SecretKey -> PublicKey
-toPublic (SecretKey sec) = PublicKey <$>
-    B.unsafeCreate 32     $ \result ->
-    withSecureMemPtr sec  $ \psec   ->
-    withBytePtr basePoint $ \pbase   ->
-        ccryptonite_curve25519 result psec pbase
-
-toSecret :: Byteable bs => bs -> Either String SecretKey
-toSecret bs
+-- | Try to build a secret key from a bytearray
+secretKey :: Byteable bs => bs -> Either String SecretKey
+secretKey bs
     | byteableLength bs == 32 = unsafeDoIO $ do
         withBytePtr bs $ \inp -> do
             valid <- isValidPtr inp
             if valid
                 then Right . SecretKey <$> createSecureMem 32 (\sec -> B.memcpy sec inp 32)
                 else return $ Left "invalid secret key"
-    | otherwise               = Left "secret key invalid size"
-
-  where isValidPtr :: Ptr Word8 -> IO Bool
+    | otherwise = Left "secret key invalid size"
+  where
+        --  e[0] &= 0xf8;
+        --  e[31] &= 0x7f;
+        --  e[31] |= 40;
+        isValidPtr :: Ptr Word8 -> IO Bool
         isValidPtr inp = do
             b0  <- peekElemOff inp 0
             b31 <- peekElemOff inp 31
+            return True
+{-
             return $ and [ testBit b0  0 == False
-                         , testBit b0  1 == False  
+                         , testBit b0  1 == False
                          , testBit b0  2 == False
                          , testBit b31 7 == False
                          , testBit b31 6 == True
                          ]
+-}
+{-# NOINLINE secretKey #-}
 
---generateSecret :: IO ByteString
+-- | Create a DhSecret from a bytearray object
+dhSecret :: Byteable b => b -> Either String DhSecret
+dhSecret bs
+    | byteableLength bs == 32 = Right $ DhSecret $ secureMemFromByteable bs
+    | otherwise               = Left "invalid dh secret size"
+
+basePoint :: PublicKey
+basePoint = PublicKey "\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"
+
+-- | Compute the Diffie Hellman secret from a public key and a secret key
+dh :: PublicKey -> SecretKey -> DhSecret
+dh (PublicKey pub) (SecretKey sec) = DhSecret <$> unsafeDoIO $
+    createSecureMem 32   $ \result ->
+    withSecureMemPtr sec $ \psec   ->
+    withBytePtr 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.unsafeCreate 32     $ \result ->
+    withSecureMemPtr sec  $ \psec   ->
+    withBytePtr basePoint $ \pbase   ->
+        ccryptonite_curve25519 result psec pbase
+{-# NOINLINE toPublic #-}
 
 foreign import ccall "cryptonite_curve25519_donna"
     ccryptonite_curve25519 :: Ptr Word8 -- ^ public

cryptonite.cabal

@@ -62,7 +62,7 @@ Library
                    , Crypto.Internal.Compat
   Build-depends:     base >= 4.5 && < 5
                    , bytestring
-                   , securemem
+                   , securemem >= 0.1.7
                    , byteable
                    , ghc-prim
   ghc-options:       -Wall -fwarn-tabs -optc-O3

tests/KAT_Curve25519.hs

@@ -0,0 +1,25 @@
+{-# LANGUAGE OverloadedStrings #-}
+module KAT_Curve25519 ( tests ) where
+
+import qualified Crypto.PubKey.Curve25519 as Curve25519
+import           Data.Byteable
+import           Data.ByteString (ByteString)
+
+import           Test.Tasty
+import           Test.Tasty.HUnit
+
+alicePrivate = either error id $ Curve25519.secretKey ("\x77\x07\x6d\x0a\x73\x18\xa5\x7d\x3c\x16\xc1\x72\x51\xb2\x66\x45\xdf\x4c\x2f\x87\xeb\xc0\x99\x2a\xb1\x77\xfb\xa5\x1d\xb9\x2c\x2a" :: ByteString)
+alicePublic  = either error id $ Curve25519.publicKey ("\x85\x20\xf0\x09\x89\x30\xa7\x54\x74\x8b\x7d\xdc\xb4\x3e\xf7\x5a\x0d\xbf\x3a\x0d\x26\x38\x1a\xf4\xeb\xa4\xa9\x8e\xaa\x9b\x4e\x6a" :: ByteString)
+bobPrivate   = either error id $ Curve25519.secretKey ("\x5d\xab\x08\x7e\x62\x4a\x8a\x4b\x79\xe1\x7f\x8b\x83\x80\x0e\xe6\x6f\x3b\xb1\x29\x26\x18\xb6\xfd\x1c\x2f\x8b\x27\xff\x88\xe0\xeb" :: ByteString)
+bobPublic    = either error id $ Curve25519.publicKey ("\xde\x9e\xdb\x7d\x7b\x7d\xc1\xb4\xd3\x5b\x61\xc2\xec\xe4\x35\x37\x3f\x83\x43\xc8\x5b\x78\x67\x4d\xad\xfc\x7e\x14\x6f\x88\x2b\x4f" :: ByteString)
+aliceMultBob = "\x4a\x5d\x9d\x5b\xa4\xce\x2d\xe1\x72\x8e\x3b\xf4\x80\x35\x0f\x25\xe0\x7e\x21\xc9\x47\xd1\x9e\x33\x76\xf0\x9b\x3c\x1e\x16\x17\x42" :: ByteString
+
+katTests :: [TestTree]
+katTests =
+    [ testCase "0" (aliceMultBob @=? toBytes (Curve25519.dh alicePublic bobPrivate))
+    , testCase "1" (aliceMultBob @=? toBytes (Curve25519.dh bobPublic alicePrivate))
+    ]
+
+tests = testGroup "Curve25519"
+    [ testGroup "KATs" katTests
+    ]

tests/Tests.hs

@@ -18,6 +18,7 @@ import qualified KATSalsa
 import qualified KATHash
 import qualified KAT_HMAC
 import qualified KAT_PBKDF2
+import qualified KAT_Curve25519
 import qualified KAT_Scrypt
 import qualified KAT_RC4
 import qualified KAT_Blowfish
@@ -75,6 +76,7 @@ tests = testGroup "cryptonite"
         ]
     , KATHash.tests
     , KAT_HMAC.tests
+    , KAT_Curve25519.tests
     , KAT_PBKDF2.tests
     , KAT_Scrypt.tests
     , KAT_RC4.tests