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hannahwhy/salsa20.hs

Created November 20, 2008 06:47
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braindead implementation of djb's salsa20
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salsa20.hs
import Bits
import Data.Word (Word32, Word64)
-- Utilities
concatBytes :: (Bits a) => a -> a -> a
concatBytes b1 b2 = (.|.) (shiftL b1 8) b2
le4 :: [Word32] -> [[Word32]]
le4 (x4:x3:x2:x1:[]) = [x1,x2,x3,x4]:[]
le4 (x4:x3:x2:x1:xs) = [x1,x2,x3,x4]:le4 xs
le4 _ = error "list length must be a multiple of 4"
-- Key and nonce setup (key and nonce values taken from djb's paper)
key :: [Word32]
key = map (foldl concatBytes 0) (take 8 (le4 [1..]))
nonce :: [Word32]
nonce = map (foldl concatBytes 0) (le4 [3,1,4,1,5,9,2,6])
counter :: [Word32]
counter = map (foldl concatBytes 0) [[0,0,0,0],[0,0,0,7]]
-- Salsa20 core (from djb's paper)
core = [0x61707865, key !! 0, key !! 1, key !! 2,
key !! 3, 0x3320646e, nonce !! 0, nonce !! 1,
counter !! 1, counter !! 0, 0x79622d32, key !! 4,
key !! 5, key !! 6, key !! 7, 0x6b206574]
-- Test vectors (from djb's paper)
round0 :: [Word32]
round0 = [0x61707865, 0x04030201, 0x08070605, 0x0c0b0a09,
0x100f0e0d, 0x3320646e, 0x01040103, 0x06020905,
0x00000007, 0x00000000, 0x79622d32, 0x14131211,
0x18171615, 0x1c1b1a19, 0x201f1e1d, 0x6b206574]
round1 :: [Word32]
round1 = [0x61707865, 0x04030201, 0x08070605, 0x95b0c8b6,
0xd3c83331, 0x3320646e, 0x01040103, 0x06020905,
0x00000007, 0x91b3379b, 0x79622d32, 0x14131211,
0x18171615, 0x1c1b1a19, 0x130804a0, 0x6b206574]
round2 :: [Word32]
round2 = [0x61707865, 0x04030201, 0xdc64a31d, 0x95b0c8b6,
0xd3c83331, 0x3320646e, 0x01040103, 0xa45e5d04,
0x71572c6d, 0x91b3379b, 0x79622d32, 0x14131211,
0x18171615, 0xbb230990, 0x130804a0, 0x6b206574]
round3 :: [Word32]
round3 = [0x61707865, 0xcc266b9b, 0xdc64a31d, 0x95b0c8b6,
0xd3c83331, 0x3320646e, 0x95f3bcee, 0xa45e5d04,
0x71572c6d, 0x91b3379b, 0x79622d32, 0xf0a45550,
0xf3e4deb6, 0xbb230990, 0x130804a0, 0x6b206574]
round4 :: [Word32]
round4 = [0x4dfdec95, 0xcc266b9b, 0xdc64a31d, 0x95b0c8b6,
0xd3c83331, 0xe78e794b, 0x95f3bcee, 0xa45e5d04,
0x71572c6d, 0x91b3379b, 0xf94fe453, 0xf0a45550,
0xf3e4deb6, 0xbb230990, 0x130804a0, 0xa272317e]
final :: [Word32]
final = [0x4dfdec95, 0xd3c83331, 0x71572c6d, 0xf3e4deb6,
0xcc266b9b, 0xe78e794b, 0x91b3379b, 0xbb230990,
0xdc64a31d, 0x95f3bcee, 0xf94fe453, 0x130804a0,
0x95b0c8b6, 0xa45e5d04, 0xf0a45550, 0xa272317e]
final2 :: [Word32]
final2 = [0xba2409b1, 0x1b7cce6a, 0x29115dcf, 0x5037e027,
0x37b75378, 0x348d94c8, 0x3ea582b3, 0xc3a9a148,
0x825bfcb9, 0x226ae9eb, 0x63dd7748, 0x7129a215,
0x4effd1ec, 0x5f25dc72, 0xa6c3d164, 0x152a26d8]
final20 :: [Word32]
final20 = [0x58318d3e, 0x0292df4f, 0xa28d8215, 0xa1aca723,
0x697a34c7, 0xf2f00ba8, 0x63e9b0a1, 0x27250e3a,
0xb1c7f1f3, 0x62066edc, 0x66d3ccf1, 0xb0365cf3,
0x091ad09e, 0x64f0c40f, 0xd60d95ea, 0x00be78c9]
--
-- x0:x1:x2:x3 x0 x1 x2 (X x3 (RL xf+xb) 7)
-- x4:x5:x6:x7 --> (X x4 (RL x0+xc 7)) x5 x6 x7
-- x8:x9:xa:xb x8 (X x9 (RL x5+x1 7)) xa xb
-- xc:xd:xe:xf xc xd (X xe (RL xa+x6) 7) xf
--
t1 :: [Word32] -> [Word32]
t1 (x0:x1:x2:x3:x4:x5:x6:x7:x8:x9:xa:xb:xc:xd:xe:xf:[]) = let m = \x y z -> xor x (rotateL (y+z) 7) in
x0:x1:x2:(m x3 xf xb):(m x4 x0 xc):x5:x6:x7:x8:(m x9 x5 x1):xa:xb:xc:xd:(m xe xa x6):xf:[]
--
-- x0:x1:x2:x3 x0 x1 (X x2 (RL xa+xe) 9) x3
-- x4:x5:x6:x7 --> x4 x5 x6 (X x7 (RL x3+xf) 9)
-- x8:x9:xa:xb (X x8 (RL x0+x4 9)) x9 xa xb
-- xc:xd:xe:xf xc (X xd (RL x5+x9 9)) xe xf
--
t2 :: [Word32] -> [Word32]
t2 (x0:x1:x2:x3:x4:x5:x6:x7:x8:x9:xa:xb:xc:xd:xe:xf:[]) = let m = \x y z -> xor x (rotateL (y+z) 9) in
x0:x1:(m x2 xa xe):x3:x4:x5:x6:(m x7 x3 xf):(m x8 x0 x4):x9:xa:xb:xc:(m xd x5 x9):xe:xf:[]
--
-- x0:x1:x2:x3 x0 (X x1 (RL x9+xd)) x2 x3
-- x4:x5:x6:x7 --> x4 x5 (X x6 (RL xe+x2)) x7
-- x8:x9:xa:xb x8 x9 xa (X xb (RL x3+x7))
-- xc:xd:xe:xf (X xc (RL x4+x8)) xd xe xf
--
t3 :: [Word32] -> [Word32]
t3 (x0:x1:x2:x3:x4:x5:x6:x7:x8:x9:xa:xb:xc:xd:xe:xf:[]) = let m = \x y z -> xor x (rotateL (y+z) 13) in
x0:(m x1 x9 xd):x2:x3:x4:x5:(m x6 xe x2):x7:x8:x9:xa:(m xb x3 x7):(m xc x4 x8):xd:xe:xf:[]
--
-- x0:x1:x2:x3 (X x0 (RL x8 xc)) x1 x2 x3
-- x4:x5:x6:x7 --> x4 (X x5 (RL xd+x1)) x6 x7
-- x8:x9:xa:xb x8 x9 (X xa (RL x2+x6) xb
-- xc:xd:xe:xf xc xd xe (X xf (RL x7+xb))
--
t4 :: [Word32] -> [Word32]
t4 (x0:x1:x2:x3:x4:x5:x6:x7:x8:x9:xa:xb:xc:xd:xe:xf:[]) = let m = \x y z -> xor x (rotateL (y+z) 18) in
(m x0 x8 xc):x1:x2:x3:x4:(m x5 xd x1):x6:x7:x8:x9:(m xa x2 x6):xb:xc:xd:xe:(m xf x7 xb):[]
--
-- x0:x1:x2:x3 x0:x4:x8:xc
-- x4:x5:x6:x7 --> x1:x5:x9:xd
-- x8:x9:xa:xb x2:x6:xa:xe
-- xc:xd:xe:xf x3:x7:xb:xf
--
t5 :: [Word32] -> [Word32]
t5 (x0:x1:x2:x3:x4:x5:x6:x7:x8:x9:xa:xb:xc:xd:xe:xf:[]) = x0:x4:x8:xc:x1:x5:x9:xd:x2:x6:xa:xe:x3:x7:xb:xf:[]
doRound :: [Word32] -> [Word32]
doRound a = (t5 . t4 . t3 . t2 . t1) a
salsa :: Int -> [Word32] -> [Word32]
salsa 1 a = doRound a
salsa n a = salsa (n - 1) (doRound a)
-- key, nonce, stream (from counter 0)
salsa20Stream :: [Word32] -> [Word32] -> [Word32]
salsa20Stream key nonce = salsa20StreamFrom 0 key nonce
salsa20StreamFrom :: Word64 -> [Word32] -> [Word32] -> [Word32]
salsa20StreamFrom from key nonce = let msw = (fromIntegral $ shiftR ((.&.) from 0xffffffff00000000) 32)
lsw = (fromIntegral $ (.&.) from 0x00000000ffffffff)
core = [0x61707865, key !! 0, key !! 1, key !! 2,
key !! 3, 0x3320646e, nonce !! 0, nonce !! 1,
lsw, msw, 0x79622d32, key !! 4,
key !! 5, key !! 6, key !! 7, 0x6b206574]
in (salsa 20 core) ++ salsa20StreamFrom (from + 1) key nonce
--
-- to replicate the example in djb's paper:
--
-- salsa 20 core == final20
-- take 16 (salsa20StreamFrom 7 key nonce) == final20
--
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