想到我試圖在Haskell中自己實現SHA1。我想出了一個編譯並返回空字符串(「」)的正確答案的實現,但沒有別的。我無法弄清楚什麼可能是錯的。熟悉算法和SHA1的人可以指出嗎?Haskell中的SHA1 - 我的實現有問題
import Data.Bits
import Data.Int
import Data.List
import Data.Word
import Text.Printf
import qualified Data.ByteString.Lazy as L
import qualified Data.ByteString.Lazy.Char8 as C
h0 = 0x67452301 :: Word32
h1 = 0xEFCDAB89 :: Word32
h2 = 0x98BADCFE :: Word32
h3 = 0x10325476 :: Word32
h4 = 0xC3D2E1F0 :: Word32
sha1string :: String -> String
sha1string s = concat $ map (printf "%02x") $ sha1 . C.pack $ s
sha1 :: L.ByteString -> [Word8]
sha1 msg = concat [w32ToComps a, w32ToComps b, w32ToComps c, w32ToComps d, w32ToComps e]
where (a, b, c, d, e) = sha1' msg 0 h0 h1 h2 h3 h4
sha1' msg sz a b c d e
| L.length m1 < 64 = sha1'last (padded msg sz) a b c d e
| otherwise = uncurry5 (sha1' m2 (sz + 64)) $ whole a b c d e m1
where (m1, m2) = L.splitAt 64 msg
sha1'last msg a b c d e
| m1 == L.empty = (a, b, c, d, e)
| otherwise = uncurry5 (sha1'last m2) $ whole a b c d e m1
where (m1, m2) = L.splitAt 64 msg
whole a b c d e msg = partcd (partab msg) a b c d e
partcd ws a b c d e = (h0 + a', h1 + b', h2 + c', h3 + d', h4 + e')
where
(a', b', c', d', e') = go ws a b c d e 0
go ws a b c d e 80 = (a, b, c, d, e)
go (w:ws) a b c d e t = go ws temp a (rotate b 30) c d (t+1)
where temp = (rotate a 5) + f t b c d + e + w + k t
partab chunk = take 80 ns
where
ns = initial ++ zipWith4 g (drop 13 ns) (drop 8 ns) (drop 2 ns) ns
g a b c d = rotate (a `xor` b `xor` c `xor` d) 1
initial = map (L.foldl (\a b -> (a * 256) + fromIntegral b) 0) $ paginate 4 chunk
f t b c d
| t >= 0 && t <= 19 = (b .&. c) .|. ((complement b) .&. d)
| t >= 20 && t <= 39 = b `xor` c `xor` d
| t >= 40 && t <= 59 = (b .&. c) .|. (b .&. d) .|. (c .&. d)
| t >= 60 && t <= 79 = b `xor` c `xor` d
k t
| t >= 0 && t <= 19 = 0x5A827999
| t >= 20 && t <= 39 = 0x6ED9EBA1
| t >= 40 && t <= 59 = 0x8F1BBCDC
| t >= 60 && t <= 79 = 0xCA62C1D6
padded msg prevsz = L.append msg (L.pack pad)
where
sz = L.length msg
totalsz = prevsz + sz
padsz = fromIntegral $ (128 - 9 - sz) `mod` 64
pad = [0x80] ++ (replicate padsz 0) ++ int64ToComps totalsz
uncurry5 f (a, b, c, d, e) = f a b c d e
paginate n xs
| xs == L.empty = []
| otherwise = let (a, b) = L.splitAt n xs in a : paginate n b
w32ToComps :: Word32 -> [Word8]
w32ToComps = integerToComps [24, 16 .. 0]
int64ToComps :: Int64 -> [Word8]
int64ToComps = integerToComps [56, 48 .. 0]
integerToComps :: (Integral a, Bits a) => [Int] -> a -> [Word8]
integerToComps bits x = map f bits
where f n = fromIntegral ((x `shiftR` n) .&. 0xff) :: Word8
調試時,如果您可以將問題縮小到調用堆棧中功能最深的地方,並且做出意想不到的事情,這會非常有幫助。你可以試着對ghci中的其他函數進行一些調用,並驗證它們是在計算你期望它們計算的內容嗎? –