Drop dependency on Thamas's crypto-api package.

1 files changed, 47 insertions, 5 deletions

diff --git a/Crypto/Cipher/ThomasToVincent.hs b/Crypto/Cipher/ThomasToVincent.hs
index 11cede3..5a68cf3 100644
--- a/Crypto/Cipher/ThomasToVincent.hs
+++ b/Crypto/Cipher/ThomasToVincent.hs
@@ -2,16 +2,57 @@
 {-# LANGUAGE ScopedTypeVariables #-}
 module Crypto.Cipher.ThomasToVincent where
 
+import qualified Data.ByteString as S
 import Crypto.Cipher.Types
+import Crypto.Cipher.Cast5
 import Data.Byteable
 
 import Data.Tagged
+{-
 import qualified Crypto.Classes as Thomas
-#if ! MIN_VERSION_crypto_api(0,11,0)
+if ! MIN_VERSION_crypto_api(0,11,0)
 import qualified Crypto.Modes as Thomas
-#endif
+endif
+-}
 
 
+type ThomasToVincent b = b
+
+instance Cast5Bits size => Cipher (Cast5 size) where
+    cipherName _ = "CAST-5"
+    cipherInit k = b
+      where Just b = buildKey (toBytes k)
+    cipherKeySize _ =  KeySizeFixed (bitlen `div` 8)
+      where Tagged bitlen = keyLength :: Tagged (Cast5 size) Int
+
+
+-- Break a bytestring into block size chunks.
+chunkFor' :: (Cast5Bits size) => Cast5 size -> S.ByteString -> [S.ByteString]
+chunkFor' k = go
+  where
+  blkSz = (Crypto.Cipher.Cast5.blockSize `for` k) `div` 8
+  go bs | S.length bs < blkSz = []
+        | otherwise           = let (blk,rest) = S.splitAt blkSz bs in blk : go rest
+
+-- |Obtain a tagged value for a particular instantiated type.
+for :: Tagged a b -> a -> b
+for t _ = unTagged t
+
+instance Cast5Bits size => BlockCipher (Cast5 size) where
+    blockSize _ = bitlen `div` 8
+     where Tagged bitlen = Crypto.Cipher.Cast5.blockSize :: Tagged (Cast5 size) Int
+
+    -- modeEcb' :: BlockCipher k => k -> B.ByteString -> B.ByteString
+    ecbEncrypt k msg =
+            let chunks = chunkFor' k msg
+                    in S.concat $ map (encryptBlock k) chunks
+
+    ecbDecrypt k ct =
+        let chunks = chunkFor' k ct
+        in S.concat $ map (decryptBlock k) chunks
+
+
+{-
 newtype ThomasToVincent b = ThomasToVincent b
 
 instance Thomas.BlockCipher b => Cipher (ThomasToVincent b) where
@@ -24,12 +65,13 @@ instance Thomas.BlockCipher b => Cipher (ThomasToVincent b) where
 instance Thomas.BlockCipher b => BlockCipher (ThomasToVincent b) where
     blockSize _ = bitlen `div` 8
      where Tagged bitlen = Thomas.blockSize :: Tagged b Int
-#if ! MIN_VERSION_crypto_api(0,11,0)
+if ! MIN_VERSION_crypto_api(0,11,0)
     ecbEncrypt (ThomasToVincent k) = Thomas.ecb' k
     ecbDecrypt (ThomasToVincent k) = Thomas.unEcb' k
-#else
+else
     ecbEncrypt (ThomasToVincent k) = Thomas.ecb k
     ecbDecrypt (ThomasToVincent k) = Thomas.unEcb k
-#endif
+endif
+-}