-- |
-- Module      : Crypto.Store.Cipher.RC2.Primitive
-- License     : BSD-style
-- Maintainer  : Olivier Chéron <olivier.cheron@gmail.com>
-- Stability   : stable
-- Portability : good
--
{-# LANGUAGE MagicHash #-}
module Crypto.Store.Cipher.RC2.Primitive
    ( Key
    , buildKey
    , encrypt
    , decrypt
    ) where

import Control.Monad (forM_)

import           Data.Bits
import           Data.ByteArray (ByteArrayAccess)
import qualified Data.ByteArray as B
import           Data.Memory.Endian (fromLE)
import           Data.Word

import Foreign.Marshal.Utils (copyBytes)
import Foreign.Storable

import GHC.Ptr (Ptr(..))

import Crypto.Store.Block


-- | Expanded RC2 key
newtype Key = Key (Block Word16) -- [ K[0], K[1], ..., K[63] ]

data Q = Q {-# UNPACK #-} !Word16 {-# UNPACK #-} !Word16
           {-# UNPACK #-} !Word16 {-# UNPACK #-} !Word16


-- Utilities

decomp64 :: Word64 -> Q
decomp64 :: Word64 -> Q
decomp64 Word64
x =
    let d :: Word16
d = Word64 -> Word16
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Word64
x Word64 -> Int -> Word64
forall a. Bits a => a -> Int -> a
`shiftR` Int
48)
        c :: Word16
c = Word64 -> Word16
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Word64
x Word64 -> Int -> Word64
forall a. Bits a => a -> Int -> a
`shiftR` Int
32)
        b :: Word16
b = Word64 -> Word16
forall a b. (Integral a, Num b) => a -> b
fromIntegral (Word64
x Word64 -> Int -> Word64
forall a. Bits a => a -> Int -> a
`shiftR` Int
16)
        a :: Word16
a = Word64 -> Word16
forall a b. (Integral a, Num b) => a -> b
fromIntegral  Word64
x
    in Word16 -> Word16 -> Word16 -> Word16 -> Q
Q Word16
a Word16
b Word16
c Word16
d

comp64 :: Q -> Word64
comp64 :: Q -> Word64
comp64 (Q Word16
a Word16
b Word16
c Word16
d) =
    (Word16 -> Word64
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word16
d Word64 -> Int -> Word64
forall a. Bits a => a -> Int -> a
`shiftL` Int
48) Word64 -> Word64 -> Word64
forall a. Bits a => a -> a -> a
.|.
    (Word16 -> Word64
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word16
c Word64 -> Int -> Word64
forall a. Bits a => a -> Int -> a
`shiftL` Int
32) Word64 -> Word64 -> Word64
forall a. Bits a => a -> a -> a
.|.
    (Word16 -> Word64
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word16
b Word64 -> Int -> Word64
forall a. Bits a => a -> Int -> a
`shiftL` Int
16) Word64 -> Word64 -> Word64
forall a. Bits a => a -> a -> a
.|.
     Word16 -> Word64
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word16
a

getR :: Q -> Word8 -> Word16
getR :: Q -> Word8 -> Word16
getR (Q Word16
a Word16
b Word16
c Word16
d) Word8
i =
    case Word8
i Word8 -> Word8 -> Word8
forall a. Bits a => a -> a -> a
.&. Word8
3 of
        Word8
0 -> Word16
a
        Word8
1 -> Word16
b
        Word8
2 -> Word16
c
        Word8
_ -> Word16
d
{-# INLINE getR #-}

setR :: Q -> Word8 -> Word16 -> Q
setR :: Q -> Word8 -> Word16 -> Q
setR (Q Word16
a Word16
b Word16
c Word16
d) Word8
i Word16
x =
    case Word8
i Word8 -> Word8 -> Word8
forall a. Bits a => a -> a -> a
.&. Word8
3 of
        Word8
0 -> Word16 -> Word16 -> Word16 -> Word16 -> Q
Q Word16
x Word16
b Word16
c Word16
d
        Word8
1 -> Word16 -> Word16 -> Word16 -> Word16 -> Q
Q Word16
a Word16
x Word16
c Word16
d
        Word8
2 -> Word16 -> Word16 -> Word16 -> Word16 -> Q
Q Word16
a Word16
b Word16
x Word16
d
        Word8
_ -> Word16 -> Word16 -> Word16 -> Word16 -> Q
Q Word16
a Word16
b Word16
c Word16
x
{-# INLINE setR #-}

rol :: Word8 -> Word16 -> Word16
rol :: Word8 -> Word16 -> Word16
rol Word8
i =
    case Word8
i Word8 -> Word8 -> Word8
forall a. Bits a => a -> a -> a
.&. Word8
3 of
        Word8
0 -> (Word16 -> Int -> Word16) -> Int -> Word16 -> Word16
forall a b c. (a -> b -> c) -> b -> a -> c
flip Word16 -> Int -> Word16
forall a. Bits a => a -> Int -> a
rotateL Int
1
        Word8
1 -> (Word16 -> Int -> Word16) -> Int -> Word16 -> Word16
forall a b c. (a -> b -> c) -> b -> a -> c
flip Word16 -> Int -> Word16
forall a. Bits a => a -> Int -> a
rotateL Int
2
        Word8
2 -> (Word16 -> Int -> Word16) -> Int -> Word16 -> Word16
forall a b c. (a -> b -> c) -> b -> a -> c
flip Word16 -> Int -> Word16
forall a. Bits a => a -> Int -> a
rotateL Int
3
        Word8
_ -> (Word16 -> Int -> Word16) -> Int -> Word16 -> Word16
forall a b c. (a -> b -> c) -> b -> a -> c
flip Word16 -> Int -> Word16
forall a. Bits a => a -> Int -> a
rotateL Int
5
{-# INLINE rol #-}

ror :: Word8 -> Word16 -> Word16
ror :: Word8 -> Word16 -> Word16
ror Word8
i =
    case Word8
i Word8 -> Word8 -> Word8
forall a. Bits a => a -> a -> a
.&. Word8
3 of
        Word8
0 -> (Word16 -> Int -> Word16) -> Int -> Word16 -> Word16
forall a b c. (a -> b -> c) -> b -> a -> c
flip Word16 -> Int -> Word16
forall a. Bits a => a -> Int -> a
rotateR Int
1
        Word8
1 -> (Word16 -> Int -> Word16) -> Int -> Word16 -> Word16
forall a b c. (a -> b -> c) -> b -> a -> c
flip Word16 -> Int -> Word16
forall a. Bits a => a -> Int -> a
rotateR Int
2
        Word8
2 -> (Word16 -> Int -> Word16) -> Int -> Word16 -> Word16
forall a b c. (a -> b -> c) -> b -> a -> c
flip Word16 -> Int -> Word16
forall a. Bits a => a -> Int -> a
rotateR Int
3
        Word8
_ -> (Word16 -> Int -> Word16) -> Int -> Word16 -> Word16
forall a b c. (a -> b -> c) -> b -> a -> c
flip Word16 -> Int -> Word16
forall a. Bits a => a -> Int -> a
rotateR Int
5
{-# INLINE ror #-}

f5 :: (a -> a) -> a -> a
f5 :: forall a. (a -> a) -> a -> a
f5 a -> a
f = a -> a
f (a -> a) -> (a -> a) -> a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> a
f (a -> a) -> (a -> a) -> a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> a
f (a -> a) -> (a -> a) -> a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> a
f (a -> a) -> (a -> a) -> a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> a
f

f6 :: (a -> a) -> a -> a
f6 :: forall a. (a -> a) -> a -> a
f6 a -> a
f = a -> a
f (a -> a) -> (a -> a) -> a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> a
f (a -> a) -> (a -> a) -> a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> a
f (a -> a) -> (a -> a) -> a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> a
f (a -> a) -> (a -> a) -> a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> a
f (a -> a) -> (a -> a) -> a -> a
forall b c a. (b -> c) -> (a -> b) -> a -> c
. a -> a
f


-- Encryption

-- | Encrypts a block using the specified key
encrypt :: Key -> Word64 -> Word64
encrypt :: Key -> Word64 -> Word64
encrypt Key
k = Q -> Word64
comp64 (Q -> Word64) -> (Word64 -> Q) -> Word64 -> Word64
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Q -> Q
enc Key
k (Q -> Q) -> (Word64 -> Q) -> Word64 -> Q
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Word64 -> Q
decomp64

enc :: Key -> Q -> Q
enc :: Key -> Q -> Q
enc Key
k Q
r =
    (Q, Int) -> Q
forall a b. (a, b) -> a
fst ((Q, Int) -> Q) -> (Q, Int) -> Q
forall a b. (a -> b) -> a -> b
$ ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a. (a -> a) -> a -> a
f5 (Key -> (Q, Int) -> (Q, Int)
mixingRound Key
k) ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ Key -> (Q, Int) -> (Q, Int)
mashingRound Key
k
        ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a. (a -> a) -> a -> a
f6 (Key -> (Q, Int) -> (Q, Int)
mixingRound Key
k) ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ Key -> (Q, Int) -> (Q, Int)
mashingRound Key
k
        ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a. (a -> a) -> a -> a
f5 (Key -> (Q, Int) -> (Q, Int)
mixingRound Key
k) (Q
r, Int
0)

-- Decryption

-- | Decrypts a block using the specified key
decrypt :: Key -> Word64 -> Word64
decrypt :: Key -> Word64 -> Word64
decrypt Key
k = Q -> Word64
comp64 (Q -> Word64) -> (Word64 -> Q) -> Word64 -> Word64
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Q -> Q
dec Key
k (Q -> Q) -> (Word64 -> Q) -> Word64 -> Q
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Word64 -> Q
decomp64

dec :: Key -> Q -> Q
dec :: Key -> Q -> Q
dec Key
k Q
r =
    (Q, Int) -> Q
forall a b. (a, b) -> a
fst ((Q, Int) -> Q) -> (Q, Int) -> Q
forall a b. (a -> b) -> a -> b
$ ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a. (a -> a) -> a -> a
f5 (Key -> (Q, Int) -> (Q, Int)
rmixingRound Key
k) ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ Key -> (Q, Int) -> (Q, Int)
rmashingRound Key
k
        ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a. (a -> a) -> a -> a
f6 (Key -> (Q, Int) -> (Q, Int)
rmixingRound Key
k) ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ Key -> (Q, Int) -> (Q, Int)
rmashingRound Key
k
        ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a. (a -> a) -> a -> a
f5 (Key -> (Q, Int) -> (Q, Int)
rmixingRound Key
k) (Q
r, Int
63)


-- Encryptiong rounds

mixUp :: Key -> Word8 -> (Q, Int) -> (Q, Int)
mixUp :: Key -> Word8 -> (Q, Int) -> (Q, Int)
mixUp Key
k Word8
i input :: (Q, Int)
input@(Q
r, Int
j) = Q -> (Q, Int) -> (Q, Int)
forall a b. a -> b -> b
seq Q
r' ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ Int -> (Q, Int) -> (Q, Int)
forall a b. a -> b -> b
seq Int
j' (Q
r', Int
j')
  where j' :: Int
j' = Int
j Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Int
1
        r' :: Q
r' = Q -> Word8 -> Word16 -> Q
setR Q
r Word8
i (Word8 -> Word16 -> Word16
rol Word8
i (Word16
ri Word16 -> Word16 -> Word16
forall a. Num a => a -> a -> a
+ Key -> Word8 -> (Q, Int) -> Word16
gmix Key
k Word8
i (Q, Int)
input))
        ri :: Word16
ri = Q -> Word8 -> Word16
getR Q
r Word8
i
{-# INLINE mixUp #-}

mixingRound :: Key -> (Q, Int) -> (Q, Int)
mixingRound :: Key -> (Q, Int) -> (Q, Int)
mixingRound Key
k = Key -> Word8 -> (Q, Int) -> (Q, Int)
mixUp Key
k Word8
3 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
mixUp Key
k Word8
2 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
mixUp Key
k Word8
1 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
mixUp Key
k Word8
0

mash :: Key -> Word8 -> (Q, Int) -> (Q, Int)
mash :: Key -> Word8 -> (Q, Int) -> (Q, Int)
mash = (Word16 -> Word16 -> Word16)
-> Key -> Word8 -> (Q, Int) -> (Q, Int)
gmash Word16 -> Word16 -> Word16
forall a. Num a => a -> a -> a
(+)
{-# INLINE mash #-}

mashingRound :: Key -> (Q, Int) -> (Q, Int)
mashingRound :: Key -> (Q, Int) -> (Q, Int)
mashingRound Key
k = Key -> Word8 -> (Q, Int) -> (Q, Int)
mash Key
k Word8
3 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
mash Key
k Word8
2 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
mash Key
k Word8
1 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
mash Key
k Word8
0


-- Decryption rounds

rmixUp :: Key -> Word8 -> (Q, Int) -> (Q, Int)
rmixUp :: Key -> Word8 -> (Q, Int) -> (Q, Int)
rmixUp Key
k Word8
i input :: (Q, Int)
input@(Q
r, Int
j) = Q -> (Q, Int) -> (Q, Int)
forall a b. a -> b -> b
seq Q
r' ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ Int -> (Q, Int) -> (Q, Int)
forall a b. a -> b -> b
seq Int
j' (Q
r', Int
j')
  where j' :: Int
j' = Int
j Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
1
        r' :: Q
r' = Q -> Word8 -> Word16 -> Q
setR Q
r Word8
i (Word16
ri Word16 -> Word16 -> Word16
forall a. Num a => a -> a -> a
- Key -> Word8 -> (Q, Int) -> Word16
gmix Key
k Word8
i (Q, Int)
input)
        ri :: Word16
ri = Word8 -> Word16 -> Word16
ror Word8
i (Q -> Word8 -> Word16
getR Q
r Word8
i)
{-# INLINE rmixUp #-}

rmixingRound :: Key -> (Q, Int) -> (Q, Int)
rmixingRound :: Key -> (Q, Int) -> (Q, Int)
rmixingRound Key
k = Key -> Word8 -> (Q, Int) -> (Q, Int)
rmixUp Key
k Word8
0 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
rmixUp Key
k Word8
1 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
rmixUp Key
k Word8
2 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
rmixUp Key
k Word8
3

rmash :: Key -> Word8 -> (Q, Int) -> (Q, Int)
rmash :: Key -> Word8 -> (Q, Int) -> (Q, Int)
rmash = (Word16 -> Word16 -> Word16)
-> Key -> Word8 -> (Q, Int) -> (Q, Int)
gmash (-)
{-# INLINE rmash #-}

rmashingRound :: Key -> (Q, Int) -> (Q, Int)
rmashingRound :: Key -> (Q, Int) -> (Q, Int)
rmashingRound Key
k = Key -> Word8 -> (Q, Int) -> (Q, Int)
rmash Key
k Word8
0 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
rmash Key
k Word8
1 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
rmash Key
k Word8
2 ((Q, Int) -> (Q, Int))
-> ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Key -> Word8 -> (Q, Int) -> (Q, Int)
rmash Key
k Word8
3


-- Generic rounds

gmix :: Key -> Word8 -> (Q, Int) -> Word16
gmix :: Key -> Word8 -> (Q, Int) -> Word16
gmix (Key Block Word16
k) Word8
i (Q
r, Int
j) = Word16
kj Word16 -> Word16 -> Word16
forall a. Num a => a -> a -> a
+ (Word16
ri1 Word16 -> Word16 -> Word16
forall a. Bits a => a -> a -> a
.&. Word16
ri2) Word16 -> Word16 -> Word16
forall a. Num a => a -> a -> a
+ (Word16 -> Word16
forall a. Bits a => a -> a
complement Word16
ri1 Word16 -> Word16 -> Word16
forall a. Bits a => a -> a -> a
.&. Word16
ri3)
  where ri1 :: Word16
ri1 = Q -> Word8 -> Word16
getR Q
r (Word8
i Word8 -> Word8 -> Word8
forall a. Num a => a -> a -> a
- Word8
1)
        ri2 :: Word16
ri2 = Q -> Word8 -> Word16
getR Q
r (Word8
i Word8 -> Word8 -> Word8
forall a. Num a => a -> a -> a
- Word8
2)
        ri3 :: Word16
ri3 = Q -> Word8 -> Word16
getR Q
r (Word8
i Word8 -> Word8 -> Word8
forall a. Num a => a -> a -> a
- Word8
3)
        kj :: Word16
kj  = Block Word16 -> Offset Word16 -> Word16
forall a. PrimType a => Block a -> Offset a -> a
unsafeIndex Block Word16
k (Int -> Offset Word16
forall a. Int -> Offset a
Offset Int
j)
{-# INLINE gmix #-}

gmash :: (Word16 -> Word16 -> Word16)
      -> Key -> Word8 -> (Q, Int) -> (Q, Int)
gmash :: (Word16 -> Word16 -> Word16)
-> Key -> Word8 -> (Q, Int) -> (Q, Int)
gmash Word16 -> Word16 -> Word16
op (Key Block Word16
k) Word8
i (Q
r, Int
j) = Q -> (Q, Int) -> (Q, Int)
forall a b. a -> b -> b
seq Q
r' ((Q, Int) -> (Q, Int)) -> (Q, Int) -> (Q, Int)
forall a b. (a -> b) -> a -> b
$ Int -> (Q, Int) -> (Q, Int)
forall a b. a -> b -> b
seq Int
j (Q
r', Int
j)
  where r' :: Q
r'  = Q -> Word8 -> Word16 -> Q
setR Q
r Word8
i (Word16
ri Word16 -> Word16 -> Word16
`op` Word16
kp)
        ri :: Word16
ri  = Q -> Word8 -> Word16
getR Q
r Word8
i
        ri1 :: Word16
ri1 = Q -> Word8 -> Word16
getR Q
r (Word8
i Word8 -> Word8 -> Word8
forall a. Num a => a -> a -> a
- Word8
1)
        kp :: Word16
kp  = Block Word16 -> Offset Word16 -> Word16
forall a. PrimType a => Block a -> Offset a -> a
unsafeIndex Block Word16
k (Offset Word16 -> Word16) -> Offset Word16 -> Word16
forall a b. (a -> b) -> a -> b
$ Int -> Offset Word16
forall a. Int -> Offset a
Offset (Word16 -> Int
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word16
ri1 Int -> Int -> Int
forall a. Bits a => a -> a -> a
.&. Int
63)
{-# INLINE gmash #-}


-- Key expansion

-- | Perform key expansion
buildKey :: ByteArrayAccess key
         => Int    -- ^ Effective key length in bits
         -> key    -- ^ Input key between 1 and 128 bytes
         -> Key    -- ^ Expanded key
buildKey :: forall key. ByteArrayAccess key => Int -> key -> Key
buildKey Int
t1 key
key = Block Word16 -> Key
Key (Block Word16 -> Key) -> Block Word16 -> Key
forall a b. (a -> b) -> a -> b
$ Block Word8 -> Block Word16
doCast (Block Word8 -> Block Word16) -> Block Word8 -> Block Word16
forall a b. (a -> b) -> a -> b
$ CountOf Word8 -> (Ptr Word8 -> IO ()) -> Block Word8
forall p a. CountOf Word8 -> (Ptr p -> IO a) -> Block Word8
createWithPtr (Int -> CountOf Word8
forall a. Int -> CountOf a
CountOf Int
128) ((Ptr Word8 -> IO ()) -> Block Word8)
-> (Ptr Word8 -> IO ()) -> Block Word8
forall a b. (a -> b) -> a -> b
$ \Ptr Word8
p -> do
    key -> Ptr Word8 -> IO ()
forall p. key -> Ptr p -> IO ()
forall ba p. ByteArrayAccess ba => ba -> Ptr p -> IO ()
B.copyByteArrayToPtr key
key Ptr Word8
p

    [Int] -> (Int -> IO ()) -> IO ()
forall (t :: * -> *) (m :: * -> *) a b.
(Foldable t, Monad m) =>
t a -> (a -> m b) -> m ()
forM_ [Int
t .. Int
127] ((Int -> IO ()) -> IO ()) -> (Int -> IO ()) -> IO ()
forall a b. (a -> b) -> a -> b
$ \Int
i -> do
        pos <- Word8 -> Word8 -> Word8
forall a. Num a => a -> a -> a
(+) (Word8 -> Word8 -> Word8) -> IO Word8 -> IO (Word8 -> Word8)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Ptr Word8 -> Int -> IO Word8
forall a. Storable a => Ptr a -> Int -> IO a
peekElemOff Ptr Word8
p (Int
i Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
1) IO (Word8 -> Word8) -> IO Word8 -> IO Word8
forall a b. IO (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> Ptr Word8 -> Int -> IO Word8
forall a. Storable a => Ptr a -> Int -> IO a
peekElemOff Ptr Word8
p (Int
i Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
t)
        let b = Block Word8 -> Offset Word8 -> Word8
forall a. PrimType a => Block a -> Offset a -> a
unsafeIndex Block Word8
piTable (Word8 -> Offset Word8
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word8
pos)
        pokeElemOff p i b

    pos' <- (Word8 -> Word8 -> Word8
forall a. Bits a => a -> a -> a
.&. Word8
tm) (Word8 -> Word8) -> IO Word8 -> IO Word8
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Ptr Word8 -> Int -> IO Word8
forall a. Storable a => Ptr a -> Int -> IO a
peekElemOff Ptr Word8
p (Int
128 Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
t8)
    let b' = Block Word8 -> Offset Word8 -> Word8
forall a. PrimType a => Block a -> Offset a -> a
unsafeIndex Block Word8
piTable (Word8 -> Offset Word8
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word8
pos')
    pokeElemOff p (128 - t8) b'

    forM_ [127 - t8, 126 - t8 .. 0] $ \Int
i -> do
        pos <- Word8 -> Word8 -> Word8
forall a. Bits a => a -> a -> a
xor (Word8 -> Word8 -> Word8) -> IO Word8 -> IO (Word8 -> Word8)
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Ptr Word8 -> Int -> IO Word8
forall a. Storable a => Ptr a -> Int -> IO a
peekElemOff Ptr Word8
p (Int
i Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Int
1) IO (Word8 -> Word8) -> IO Word8 -> IO Word8
forall a b. IO (a -> b) -> IO a -> IO b
forall (f :: * -> *) a b. Applicative f => f (a -> b) -> f a -> f b
<*> Ptr Word8 -> Int -> IO Word8
forall a. Storable a => Ptr a -> Int -> IO a
peekElemOff Ptr Word8
p (Int
i Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Int
t8)
        let b = Block Word8 -> Offset Word8 -> Word8
forall a. PrimType a => Block a -> Offset a -> a
unsafeIndex Block Word8
piTable (Word8 -> Offset Word8
forall a b. (Integral a, Num b) => a -> b
fromIntegral Word8
pos)
        pokeElemOff p i b

  where t :: Int
t  = key -> Int
forall ba. ByteArrayAccess ba => ba -> Int
B.length key
key
        t8 :: Int
t8 = (Int
t1 Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Int
7) Int -> Int -> Int
forall a. Integral a => a -> a -> a
`div` Int
8
        tm :: Word8
tm | Int
t1 Int -> Int -> Bool
forall a. Eq a => a -> a -> Bool
== Int
8 Int -> Int -> Int
forall a. Num a => a -> a -> a
* Int
t8 = Word8
255
           | Bool
otherwise    = Word8
255 Word8 -> Word8 -> Word8
forall a. Integral a => a -> a -> a
`mod` Word8 -> Int -> Word8
forall a. Bits a => a -> Int -> a
shiftL Word8
1 (Int
8 Int -> Int -> Int
forall a. Num a => a -> a -> a
+ Int
t1 Int -> Int -> Int
forall a. Num a => a -> a -> a
- Int
8 Int -> Int -> Int
forall a. Num a => a -> a -> a
* Int
t8)

        doCast :: Block Word8 -> Block Word16
        doCast :: Block Word8 -> Block Word16
doCast = (LE Word16 -> Word16) -> Block (LE Word16) -> Block Word16
forall a b.
(PrimType a, PrimType b) =>
(a -> b) -> Block a -> Block b
Crypto.Store.Block.map LE Word16 -> Word16
forall a. ByteSwap a => LE a -> a
fromLE (Block (LE Word16) -> Block Word16)
-> (Block Word8 -> Block (LE Word16))
-> Block Word8
-> Block Word16
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Block Word8 -> Block (LE Word16)
forall a b. Block a -> Block b
unsafeCast


-- PITABLE

piTable :: Block Word8
piTable :: Block Word8
piTable = CountOf Word8 -> (Ptr (ZonkAny 0) -> IO ()) -> Block Word8
forall p a. CountOf Word8 -> (Ptr p -> IO a) -> Block Word8
createWithPtr (Int -> CountOf Word8
forall a. Int -> CountOf a
CountOf Int
bytes) ((Ptr (ZonkAny 0) -> IO ()) -> Block Word8)
-> (Ptr (ZonkAny 0) -> IO ()) -> Block Word8
forall a b. (a -> b) -> a -> b
$ \Ptr (ZonkAny 0)
p -> Ptr (ZonkAny 0) -> Ptr (ZonkAny 0) -> Int -> IO ()
forall a. Ptr a -> Ptr a -> Int -> IO ()
copyBytes Ptr (ZonkAny 0)
p (Addr# -> Ptr (ZonkAny 0)
forall a. Addr# -> Ptr a
Ptr Addr#
addr#) Int
bytes
  where
    bytes :: Int
bytes = Int
256
    addr# :: Addr#
addr# =
        Addr#
"\xd9\x78\xf9\xc4\x19\xdd\xb5\xed\x28\xe9\xfd\x79\x4a\xa0\xd8\x9d\
        \\xc6\x7e\x37\x83\x2b\x76\x53\x8e\x62\x4c\x64\x88\x44\x8b\xfb\xa2\
        \\x17\x9a\x59\xf5\x87\xb3\x4f\x13\x61\x45\x6d\x8d\x09\x81\x7d\x32\
        \\xbd\x8f\x40\xeb\x86\xb7\x7b\x0b\xf0\x95\x21\x22\x5c\x6b\x4e\x82\
        \\x54\xd6\x65\x93\xce\x60\xb2\x1c\x73\x56\xc0\x14\xa7\x8c\xf1\xdc\
        \\x12\x75\xca\x1f\x3b\xbe\xe4\xd1\x42\x3d\xd4\x30\xa3\x3c\xb6\x26\
        \\x6f\xbf\x0e\xda\x46\x69\x07\x57\x27\xf2\x1d\x9b\xbc\x94\x43\x03\
        \\xf8\x11\xc7\xf6\x90\xef\x3e\xe7\x06\xc3\xd5\x2f\xc8\x66\x1e\xd7\
        \\x08\xe8\xea\xde\x80\x52\xee\xf7\x84\xaa\x72\xac\x35\x4d\x6a\x2a\
        \\x96\x1a\xd2\x71\x5a\x15\x49\x74\x4b\x9f\xd0\x5e\x04\x18\xa4\xec\
        \\xc2\xe0\x41\x6e\x0f\x51\xcb\xcc\x24\x91\xaf\x50\xa1\xf4\x70\x39\
        \\x99\x7c\x3a\x85\x23\xb8\xb4\x7a\xfc\x02\x36\x5b\x25\x55\x97\x31\
        \\x2d\x5d\xfa\x98\xe3\x8a\x92\xae\x05\xdf\x29\x10\x67\x6c\xba\xc9\
        \\xd3\x00\xe6\xcf\xe1\x9e\xa8\x2c\x63\x16\x01\x3f\x58\xe2\x89\xa9\
        \\x0d\x38\x34\x1b\xab\x33\xff\xb0\xbb\x48\x0c\x5f\xb9\xb1\xcd\x2e\
        \\xc5\xf3\xdb\x47\xe5\xa5\x9c\x77\x0a\xa6\x20\x68\xfe\x7f\xc1\xad"#