{-# LANGUAGE FlexibleInstances #-} module Codec.Encryption.DESAux (des_enc, des_dec) where import Data.Word import Data.Bits type Rotation = Int type Key = Word64 type Message = Word64 type Enc = Word64 type BitsX = [Bool] type Bits4 = [Bool] type Bits6 = [Bool] type Bits32 = [Bool] type Bits48 = [Bool] type Bits56 = [Bool] type Bits64 = [Bool] instance Num [Bool] instance Bits [Bool] where a `xor` b = (zipWith (\x y -> (not x && y) || (x && not y)) a b) rotate bits rot = drop rot' bits ++ take rot' bits where rot' = rot `mod` (length bits) bitify :: Word64 -> Bits64 bitify w = map (\b -> w .&. (shiftL 1 b) /= 0) [63,62..0] unbitify :: Bits64 -> Word64 unbitify bs = foldl (\i b -> if b then 1 + shiftL i 1 else shiftL i 1) 0 bs initial_permutation :: Bits64 -> Bits64 initial_permutation mb = map ((!!) mb) i where i = [57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7, 56, 48, 40, 32, 24, 16, 8, 0, 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6] key_transformation :: Bits64 -> Bits56 key_transformation kb = map ((!!) kb) i where i = [56, 48, 40, 32, 24, 16, 8, 0, 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 60, 52, 44, 36, 28, 20, 12, 4, 27, 19, 11, 3] des_enc :: Message -> Key -> Enc des_enc = do_des [1,2,4,6,8,10,12,14,15,17,19,21,23,25,27,28] des_dec :: Message -> Key -> Enc des_dec = do_des [28,27,25,23,21,19,17,15,14,12,10,8,6,4,2,1] do_des :: [Rotation] -> Message -> Key -> Enc do_des rots m k = des_work rots (takeDrop 32 mb) kb where kb = key_transformation $ bitify k mb = initial_permutation $ bitify m des_work :: [Rotation] -> (Bits32, Bits32) -> Bits56 -> Enc des_work [] (ml, mr) _ = unbitify $ final_perm $ (mr ++ ml) des_work (r:rs) mb kb = des_work rs mb' kb where mb' = do_round r mb kb do_round :: Rotation -> (Bits32, Bits32) -> Bits56 -> (Bits32, Bits32) do_round r (ml, mr) kb = (mr, m') where kb' = get_key kb r comp_kb = compression_permutation kb' expa_mr = expansion_permutation mr res = comp_kb `xor` expa_mr res' = tail $ iterate (trans 6) ([], res) trans n (_, b) = (take n b, drop n b) res_s = concat $ zipWith (\f (x,_) -> f x) [s_box_1, s_box_2, s_box_3, s_box_4, s_box_5, s_box_6, s_box_7, s_box_8] res' res_p = p_box res_s m' = res_p `xor` ml get_key :: Bits56 -> Rotation -> Bits56 get_key kb r = kb' where (kl, kr) = takeDrop 28 kb kb' = rotateL kl r ++ rotateL kr r compression_permutation :: Bits56 -> Bits48 compression_permutation kb = map ((!!) kb) i where i = [13, 16, 10, 23, 0, 4, 2, 27, 14, 5, 20, 9, 22, 18, 11, 3, 25, 7, 15, 6, 26, 19, 12, 1, 40, 51, 30, 36, 46, 54, 29, 39, 50, 44, 32, 47, 43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31] expansion_permutation :: Bits32 -> Bits48 expansion_permutation mb = map ((!!) mb) i where i = [31, 0, 1, 2, 3, 4, 3, 4, 5, 6, 7, 8, 7, 8, 9, 10, 11, 12, 11, 12, 13, 14, 15, 16, 15, 16, 17, 18, 19, 20, 19, 20, 21, 22, 23, 24, 23, 24, 25, 26, 27, 28, 27, 28, 29, 30, 31, 0] s_box :: [[Word8]] -> Bits6 -> Bits4 s_box s [a,b,c,d,e,f] = to_bool 4 $ (s !! row) !! col where row = sum $ zipWith numericise [a,f] [1, 0] col = sum $ zipWith numericise [b,c,d,e] [3, 2, 1, 0] numericise = (\x y -> if x then 2^y else 0) to_bool 0 _ = [] to_bool n i = ((i .&. 8) == 8):to_bool (n-1) (shiftL i 1) s_box_1 :: Bits6 -> Bits4 s_box_1 = s_box i where i = [[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7], [ 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8], [ 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0], [15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13]] s_box_2 :: Bits6 -> Bits4 s_box_2 = s_box i where i = [[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10], [3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5], [0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15], [13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9]] s_box_3 :: Bits6 -> Bits4 s_box_3 = s_box i where i = [[10, 0, 9, 14 , 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8], [13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1], [13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7], [1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12]] s_box_4 :: Bits6 -> Bits4 s_box_4 = s_box i where i = [[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15], [13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9], [10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4], [3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14]] s_box_5 :: Bits6 -> Bits4 s_box_5 = s_box i where i = [[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9], [14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6], [4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14], [11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3]] s_box_6 :: Bits6 -> Bits4 s_box_6 = s_box i where i = [[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11], [10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8], [9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6], [4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13]] s_box_7 :: Bits6 -> Bits4 s_box_7 = s_box i where i = [[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1], [13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6], [1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2], [6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12]] s_box_8 :: Bits6 -> Bits4 s_box_8 = s_box i where i = [[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7], [1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2], [7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8], [2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11]] p_box :: Bits32 -> Bits32 p_box kb = map ((!!) kb) i where i = [15, 6, 19, 20, 28, 11, 27, 16, 0, 14, 22, 25, 4, 17, 30, 9, 1, 7, 23, 13, 31, 26, 2, 8, 18, 12, 29, 5, 21, 10, 3, 24] final_perm :: Bits64 -> Bits64 final_perm kb = map ((!!) kb) i where i = [39, 7, 47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25, 32, 0, 40 , 8, 48, 16, 56, 24] takeDrop :: Int -> [a] -> ([a], [a]) takeDrop _ [] = ([], []) takeDrop 0 xs = ([], xs) takeDrop n (x:xs) = (x:ys, zs) where (ys, zs) = takeDrop (n-1) xs