From 3af88f3145edc987f2ca37a1334eab5050835019 Mon Sep 17 00:00:00 2001
From: Kei Hibino <ex8k.hibino@gmail.com>
Date: Fri, 8 Apr 2016 16:11:17 +0900
Subject: [PATCH] Add smart constructor of MiyaguchiPreneel hash type.

---
 Crypto/ConstructHash/MiyaguchiPreneel.hs | 24 ++++++++++++++++++------
 tests/KAT_MiyaguchiPreneel.hs            |  3 ++-
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/Crypto/ConstructHash/MiyaguchiPreneel.hs b/Crypto/ConstructHash/MiyaguchiPreneel.hs
index a49a33b..e7f14b8 100644
--- a/Crypto/ConstructHash/MiyaguchiPreneel.hs
+++ b/Crypto/ConstructHash/MiyaguchiPreneel.hs
@@ -8,7 +8,12 @@
 -- provide the hash function construction method from block cipher
 -- <https://en.wikipedia.org/wiki/One-way_compression_function>
 --
-module Crypto.ConstructHash.MiyaguchiPreneel ( mp, cipherInit' ) where
+{-# LANGUAGE GeneralizedNewtypeDeriving #-}
+module Crypto.ConstructHash.MiyaguchiPreneel
+       ( mp
+       , MiyaguchiPreneel(..)
+       , cipherInit'
+       ) where
 
 import           Data.List (foldl')
 
@@ -18,13 +23,20 @@ import           Crypto.Internal.ByteArray (ByteArrayAccess, ByteArray, Bytes)
 import qualified Crypto.Internal.ByteArray as B
 
 
+newtype MiyaguchiPreneel a = MP { chashGetBytes :: Bytes }
+    deriving ByteArrayAccess
+
+instance Eq (MiyaguchiPreneel a) where
+    MP b1 == MP b2  =  B.constEq b1 b2
+
+
 -- | Compute Miyaguchi-Preneel one way compress using the supplied block cipher.
 --   Simple usage /mp (cipherInit' :: ByteString -> AES128) msg/
-mp :: (ByteArrayAccess bin, ByteArray bout, ByteArray ba, BlockCipher cipher)
-   => (ba -> cipher) -- ^ key build function to compute Miyaguchi-Preneel
-   -> bin            -- ^ input message
-   -> bout           -- ^ output tag
-mp g = B.convert . foldl' (step $ g . B.convert) (B.replicate bsz 0) . chunks . B.convert
+mp :: (ByteArrayAccess bin, ByteArray ba, BlockCipher cipher)
+   => (ba -> cipher)          -- ^ key build function to compute Miyaguchi-Preneel
+   -> bin                     -- ^ input message
+   -> MiyaguchiPreneel cipher -- ^ output tag
+mp g = MP . foldl' (step $ g . B.convert) (B.replicate bsz 0) . chunks . B.convert
   where
     bsz = blockSize ( g B.empty {- dummy to get block size -} )
     chunks msg
diff --git a/tests/KAT_MiyaguchiPreneel.hs b/tests/KAT_MiyaguchiPreneel.hs
index f117e2f..24bfd35 100644
--- a/tests/KAT_MiyaguchiPreneel.hs
+++ b/tests/KAT_MiyaguchiPreneel.hs
@@ -8,10 +8,11 @@ import           Imports
 
 import           Data.Char (digitToInt)
 import qualified Data.ByteString as BS
+import qualified Data.ByteArray as B
 
 
 runMP128 :: ByteString -> ByteString
-runMP128 = mp (cipherInit' :: ByteString -> AES128)
+runMP128 s = B.convert $ mp (cipherInit' :: ByteString -> AES128) s
 
 hxs :: String -> ByteString
 hxs = BS.pack . rec' where