144 lines
5.6 KiB
Haskell
144 lines
5.6 KiB
Haskell
-- |
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-- Module : Crypto.Cipher.Blowfish.Primitive
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-- License : BSD-style
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-- Stability : experimental
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-- Portability : Good
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-- Rewritten by Vincent Hanquez (c) 2015
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--
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-- Original code:
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-- Crypto.Cipher.Blowfish.Primitive, copyright (c) 2012 Stijn van Drongelen
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-- based on: BlowfishAux.hs (C) 2002 HardCore SoftWare, Doug Hoyte
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-- (as found in Crypto-4.2.4)
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module Crypto.Cipher.Blowfish.Primitive
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( Context
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, initBlowfish
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, encrypt
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, decrypt
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) where
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import Control.Monad (forM_)
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import Data.Bits
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import Data.Word
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import qualified Data.ByteString as B
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import Crypto.Error
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import Crypto.Internal.Compat
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import Crypto.Internal.ByteArray
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import Crypto.Internal.Words
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import Crypto.Internal.WordArray
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import Crypto.Cipher.Blowfish.Box
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-- | variable keyed blowfish state
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data Context = BF (Int -> Word32) -- p
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(Int -> Word32) -- sbox0
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(Int -> Word32) -- sbox1
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(Int -> Word32) -- sbox2
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(Int -> Word32) -- sbox2
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encrypt, decrypt :: ByteArray ba => Context -> ba -> ba
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encrypt = cipher
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decrypt = cipher . decryptContext
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decryptContext :: Context -> Context
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decryptContext (BF p s0 s1 s2 s3) = BF (\i -> p (17-i)) s0 s1 s2 s3
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cipher :: ByteArray ba => Context -> ba -> ba
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cipher ctx b
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| byteArrayLength b == 0 = empty
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| byteArrayLength b `mod` 8 /= 0 = error "invalid data length"
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| otherwise = byteArrayMapAsWord64 (coreCrypto ctx) b
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initBlowfish :: ByteArray key => key -> CryptoFailable Context
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initBlowfish key
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| len > (448 `div` 8) = CryptoFailed $ CryptoError_KeySizeInvalid
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| len == 0 = keyFromByteString (B.replicate (18*4) 0)
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| otherwise = keyFromByteString . B.pack . take (18*4) . cycle . B.unpack . byteArrayToBS $ key
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where len = byteArrayLength key
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keyFromByteString :: B.ByteString -> CryptoFailable Context
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keyFromByteString k
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| B.length k /= (18 * 4) = CryptoFailed CryptoError_KeySizeInvalid
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| otherwise = CryptoPassed . makeKeySchedule . w8tow32 . B.unpack $ k
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where
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w8tow32 :: [Word8] -> [Word32]
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w8tow32 [] = []
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w8tow32 (a:b:c:d:xs) = ( (fromIntegral a `shiftL` 24) .|.
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(fromIntegral b `shiftL` 16) .|.
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(fromIntegral c `shiftL` 8) .|.
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(fromIntegral d) ) : w8tow32 xs
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w8tow32 _ = error $ "internal error: Crypto.Cipher.Blowfish:keyFromByteString"
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coreCrypto :: Context -> Word64 -> Word64
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coreCrypto (BF p s0 s1 s2 s3) input = doRound input 0
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where
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-- transform the input @i over 16 rounds
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doRound :: Word64 -> Int -> Word64
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doRound i roundIndex
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| roundIndex == 16 =
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let final = (fromIntegral (p 16) `shiftL` 32) .|. fromIntegral (p 17)
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in rotateL (i `xor` final) 32
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| otherwise =
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let newr = fromIntegral (i `shiftR` 32) `xor` (p roundIndex)
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newi = ((i `shiftL` 32) `xor` (f newr)) .|. (fromIntegral newr)
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in doRound newi (roundIndex+1)
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f :: Word32 -> Word64
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f t = let a = s0 (fromIntegral $ (t `shiftR` 24) .&. 0xff)
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b = s1 (fromIntegral $ (t `shiftR` 16) .&. 0xff)
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c = s2 (fromIntegral $ (t `shiftR` 8) .&. 0xff)
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d = s3 (fromIntegral $ t .&. 0xff)
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in fromIntegral (((a + b) `xor` c) + d) `shiftL` 32
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makeKeySchedule :: [Word32] -> Context
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makeKeySchedule key =
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let v = unsafeDoIO $ do
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mv <- createKeySchedule
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forM_ (zip key [0..17]) $ \(k, i) -> mutableArrayWriteXor32 mv i k
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prepare mv
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mutableArray32Freeze mv
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in BF (\i -> arrayRead32 v i)
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(\i -> arrayRead32 v (s0+i))
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(\i -> arrayRead32 v (s1+i))
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(\i -> arrayRead32 v (s2+i))
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(\i -> arrayRead32 v (s3+i))
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where
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s0 = 18
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s1 = 274
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s2 = 530
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s3 = 786
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prepare mctx = loop 0 0
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where loop i input
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| i == 1042 = return ()
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| otherwise = do
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ninput <- coreCryptoMutable input
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let (nl, nr) = w64to32 ninput
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mutableArrayWrite32 mctx i nl
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mutableArrayWrite32 mctx (i+1) nr
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loop (i+2) ninput
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coreCryptoMutable :: Word64 -> IO Word64
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coreCryptoMutable input = doRound input 0
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where doRound i roundIndex
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| roundIndex == 16 = do
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pVal1 <- mutableArrayRead32 mctx 16
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pVal2 <- mutableArrayRead32 mctx 17
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let final = (fromIntegral pVal1 `shiftL` 32) .|. fromIntegral pVal2
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return $ rotateL (i `xor` final) 32
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| otherwise = do
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pVal <- mutableArrayRead32 mctx roundIndex
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let newr = fromIntegral (i `shiftR` 32) `xor` pVal
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newr' <- f newr
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let newi = ((i `shiftL` 32) `xor` newr') .|. (fromIntegral newr)
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doRound newi (roundIndex+1)
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f :: Word32 -> IO Word64
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f t = do a <- mutableArrayRead32 mctx (s0 + fromIntegral ((t `shiftR` 24) .&. 0xff))
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b <- mutableArrayRead32 mctx (s1 + fromIntegral ((t `shiftR` 16) .&. 0xff))
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c <- mutableArrayRead32 mctx (s2 + fromIntegral ((t `shiftR` 8) .&. 0xff))
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d <- mutableArrayRead32 mctx (s3 + fromIntegral (t .&. 0xff))
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return (fromIntegral (((a + b) `xor` c) + d) `shiftL` 32)
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