gistfile1.hs

-- Take *that*, retiman!

-- It's my general ignorance of Haskell, or the awfulness of 
-- Haskell's SHA1 library, or something.  This is the best way I 
-- could find to turn whatever that SHA1 library returns into a 
-- regular string to compare with other strings.

str2octets = concatMap ((toOctets 256) . ord)
hashString = hash . str2octets

octetsToNumber [] = 0
octetsToNumber (x:xs) =
        ((toInteger x) * (256 ^ (length xs))) + (octetsToNumber xs)

word160toInteger x =
        let (Word160 a b c d e) = x in
                (toInteger a) * (2 ^ (4 * 32)) +
                        (toInteger b) * (2 ^ (3 * 32)) +
                        (toInteger c) * (2 ^ (2 * 32)) +
                        (toInteger d) * (2 ^ (1 * 32)) +
                        (toInteger e)

word160toOctets x =
        let (Word160 a b c d e) = x in
                concatMap (toOctets 256) $ [a, b, c, d, e]

sha1sum :: String -> String
sha1sum s = printf "%x" $ word160toInteger $ hashString s