    -- | Advanced Encryption System (specification can be found in FIPS-197)
    module Codec.Encryption.AESAux(
    	aes128Encrypt,
    	aes192Encrypt,
    	aes256Encrypt,
    	aes128Decrypt,
    	aes192Decrypt,
    	aes256Decrypt,
    ) where

    import Data.Bits
    import Data.Int(Int)
    import Data.Word(Word32)

    import Codec.Utils(Octet)

    aes128Encrypt :: [Octet] -- ^ key (16 octets)
    	      -> [Octet] -- ^ msg (16 octets)
    	      -> [Octet] -- ^ enciphered msg (16 octets)
    aes128Encrypt = aesEncrypt 10 4

    aes192Encrypt :: [Octet] -- ^ key (24 octets)
    	      -> [Octet] -- ^ msg (16 octets)
    	      -> [Octet] -- ^ enciphered msg (16 octets)
    aes192Encrypt = aesEncrypt 12 6

    aes256Encrypt :: [Octet] -- ^ key (32 octets)
    	      -> [Octet] -- ^ msg (16 octets)
    	      -> [Octet] -- ^ enciphered msg (16 octets)
    aes256Encrypt = aesEncrypt 14 8

    aes128Decrypt :: [Octet] -- ^ key (16 octets)
    	      -> [Octet] -- ^ enciphered msg (16 octets)
    	      -> [Octet] -- ^ deciphered msg (16 octets)
    aes128Decrypt = aesDecrypt 10 4

    aes192Decrypt :: [Octet] -- ^ key (24 octets)
    	      -> [Octet] -- ^ enciphered msg (16 octets)
    	      -> [Octet] -- ^ deciphered msg (16 octets)
    aes192Decrypt = aesDecrypt 12 6

    aes256Decrypt :: [Octet] -- ^ key (32 octets)
    	      -> [Octet] -- ^ enciphered msg (16 octets)
    	      -> [Octet] -- ^ deciphered msg (16 octets)
    aes256Decrypt = aesDecrypt 14 8

    aesEncrypt :: Int     -- ^ nr
    	   -> Int     -- ^ nk
    	   -> [Octet] -- ^ key
    	   -> [Octet] -- ^ msg
    	   -> [Octet] -- ^ enciphered msg
    aesEncrypt nr nk key
    		[i00, i10, i20, i30,
    		 i01, i11, i21, i31,
    		 i02, i12, i22, i32,
    		 i03, i13, i23, i33] =
    		[fo o00, fo o10, fo o20, fo o30,
    		 fo o01, fo o11, fo o21, fo o31,
    		 fo o02, fo o12, fo o22, fo o32,
    		 fo o03, fo o13, fo o23, fo o33]
    	where State (o00, o01, o02, o03)
    		    (o10, o11, o12, o13)
    		    (o20, o21, o22, o23)
    		    (o30, o31, o32, o33) = transform (
    		    	State(fi i00, fi i01, fi i02, fi i03)
    		    	     (fi i10, fi i11, fi i12, fi i13)
    		    	     (fi i20, fi i21, fi i22, fi i23)
    		    	     (fi i30, fi i31, fi i32, fi i33))
    	      fi = (fromIntegral :: Octet -> Word32)
    	      fo = (fromIntegral :: Word32 -> Octet)
    	      (kt0:kts) = genAddRoundKey (generateKeys nr nk key)
    	      transform = foldr (.) kt0 (reverse rest)
    	      mss = replicate (nr - 1) (mixColumns . shiftRows . subBytes)
    	      rest = zipWith (.) kts (mss ++ [shiftRows . subBytes ])

    aesDecrypt :: Int     -- ^ nr
    	   -> Int     -- ^ nk
    	   -> [Octet] -- ^ key
    	   -> [Octet] -- ^ enciphered msg
    	   -> [Octet] -- ^ deciphered msg
    aesDecrypt nr nk key
    		[i00, i10, i20, i30,
    		 i01, i11, i21, i31,
    		 i02, i12, i22, i32,
    		 i03, i13, i23, i33] =
    		[fo o00, fo o10, fo o20, fo o30,
    		 fo o01, fo o11, fo o21, fo o31,
    		 fo o02, fo o12, fo o22, fo o32,
    		 fo o03, fo o13, fo o23, fo o33]
    	where State (o00, o01, o02, o03)
    		    (o10, o11, o12, o13)
    		    (o20, o21, o22, o23)
    		    (o30, o31, o32, o33) = transform (
    		    	State(fi i00, fi i01, fi i02, fi i03)
    		    	     (fi i10, fi i11, fi i12, fi i13)
    		    	     (fi i20, fi i21, fi i22, fi i23)
    		    	     (fi i30, fi i31, fi i32, fi i33))
    	      fi = (fromIntegral :: Octet -> Word32)
    	      fo = (fromIntegral :: Word32 -> Octet)
    	      (kt0:kts) = reverse (genAddRoundKey (generateKeys nr nk key))
    	      transform = foldr (.) kt0 (reverse rest)
    	      ssm = replicate (nr - 1)
    	      			(subBytesRev . shiftRowsRev . mixColumnsRev)
    	      rest = zipWith (.) kts ([subBytesRev . shiftRowsRev] ++ ssm)

    data State =  State !(Word32, Word32, Word32, Word32)
    		    !(Word32, Word32, Word32, Word32)
    		    !(Word32, Word32, Word32, Word32)
    		    !(Word32, Word32, Word32, Word32)

    sbox :: Word32 -> Word32
    sboxRev :: Word32 -> Word32

    sbox 0x00 = 0x63
    sbox 0x01 = 0x7C
    sbox 0x02 = 0x77
    sbox 0x03 = 0x7B
    sbox 0x04 = 0xF2
    sbox 0x05 = 0x6B
    sbox 0x06 = 0x6F
    sbox 0x07 = 0xC5

    sbox 0x08 = 0x30
    sbox 0x09 = 0x01
    sbox 0x0a = 0x67
    sbox 0x0b = 0x2B
    sbox 0x0c = 0xFE
    sbox 0x0d = 0xD7
    sbox 0x0e = 0xAB
    sbox 0x0f = 0x76

    sbox 0x10 = 0xCA
    sbox 0x11 = 0x82
    sbox 0x12 = 0xC9
    sbox 0x13 = 0x7D
    sbox 0x14 = 0xFA
    sbox 0x15 = 0x59
    sbox 0x16 = 0x47
    sbox 0x17 = 0xF0

    sbox 0x18 = 0xAD
    sbox 0x19 = 0xD4
    sbox 0x1a = 0xA2
    sbox 0x1b = 0xAF
    sbox 0x1c = 0x9C
    sbox 0x1d = 0xA4
    sbox 0x1e = 0x72
    sbox 0x1f = 0xC0

    sbox 0x20 = 0xB7
    sbox 0x21 = 0xFD
    sbox 0x22 = 0x93
    sbox 0x23 = 0x26
    sbox 0x24 = 0x36
    sbox 0x25 = 0x3F
    sbox 0x26 = 0xF7
    sbox 0x27 = 0xCC

    sbox 0x28 = 0x34
    sbox 0x29 = 0xA5
    sbox 0x2a = 0xE5
    sbox 0x2b = 0xF1
    sbox 0x2c = 0x71
    sbox 0x2d = 0xD8
    sbox 0x2e = 0x31
    sbox 0x2f = 0x15

    sbox 0x30 = 0x04
    sbox 0x31 = 0xC7
    sbox 0x32 = 0x23
    sbox 0x33 = 0xC3
    sbox 0x34 = 0x18
    sbox 0x35 = 0x96
    sbox 0x36 = 0x05
    sbox 0x37 = 0x9A

    sbox 0x38 = 0x07
    sbox 0x39 = 0x12
    sbox 0x3a = 0x80
    sbox 0x3b = 0xE2
    sbox 0x3c = 0xEB
    sbox 0x3d = 0x27
    sbox 0x3e = 0xB2
    sbox 0x3f = 0x75

    sbox 0x40 = 0x09
    sbox 0x41 = 0x83
    sbox 0x42 = 0x2C
    sbox 0x43 = 0x1A
    sbox 0x44 = 0x1B
    sbox 0x45 = 0x6E
    sbox 0x46 = 0x5A
    sbox 0x47 = 0xA0

    sbox 0x48 = 0x52
    sbox 0x49 = 0x3B
    sbox 0x4a = 0xD6
    sbox 0x4b = 0xB3
    sbox 0x4c = 0x29
    sbox 0x4d = 0xE3
    sbox 0x4e = 0x2F
    sbox 0x4f = 0x84

    sbox 0x50 = 0x53
    sbox 0x51 = 0xD1
    sbox 0x52 = 0x00
    sbox 0x53 = 0xED
    sbox 0x54 = 0x20
    sbox 0x55 = 0xFC
    sbox 0x56 = 0xB1
    sbox 0x57 = 0x5B

    sbox 0x58 = 0x6A
    sbox 0x59 = 0xCB
    sbox 0x5a = 0xBE
    sbox 0x5b = 0x39
    sbox 0x5c = 0x4A
    sbox 0x5d = 0x4C
    sbox 0x5e = 0x58
    sbox 0x5f = 0xCF

    sbox 0x60 = 0xD0
    sbox 0x61 = 0xEF
    sbox 0x62 = 0xAA
    sbox 0x63 = 0xFB
    sbox 0x64 = 0x43
    sbox 0x65 = 0x4D
    sbox 0x66 = 0x33
    sbox 0x67 = 0x85

    sbox 0x68 = 0x45
    sbox 0x69 = 0xF9
    sbox 0x6a = 0x02
    sbox 0x6b = 0x7F
    sbox 0x6c = 0x50
    sbox 0x6d = 0x3C
    sbox 0x6e = 0x9F
    sbox 0x6f = 0xA8

    sbox 0x70 = 0x51
    sbox 0x71 = 0xA3
    sbox 0x72 = 0x40
    sbox 0x73 = 0x8F
    sbox 0x74 = 0x92
    sbox 0x75 = 0x9D
    sbox 0x76 = 0x38
    sbox 0x77 = 0xF5

    sbox 0x78 = 0xBC
    sbox 0x79 = 0xB6
    sbox 0x7a = 0xDA
    sbox 0x7b = 0x21
    sbox 0x7c = 0x10
    sbox 0x7d = 0xFF
    sbox 0x7e = 0xF3
    sbox 0x7f = 0xD2

    sbox 0x80 = 0xCD
    sbox 0x81 = 0x0C
    sbox 0x82 = 0x13
    sbox 0x83 = 0xEC
    sbox 0x84 = 0x5F
    sbox 0x85 = 0x97
    sbox 0x86 = 0x44
    sbox 0x87 = 0x17

    sbox 0x88 = 0xC4
    sbox 0x89 = 0xA7
    sbox 0x8a = 0x7E
    sbox 0x8b = 0x3D
    sbox 0x8c = 0x64
    sbox 0x8d = 0x5D
    sbox 0x8e = 0x19
    sbox 0x8f = 0x73

    sbox 0x90 = 0x60
    sbox 0x91 = 0x81
    sbox 0x92 = 0x4F
    sbox 0x93 = 0xDC
    sbox 0x94 = 0x22
    sbox 0x95 = 0x2A
    sbox 0x96 = 0x90
    sbox 0x97 = 0x88

    sbox 0x98 = 0x46
    sbox 0x99 = 0xEE
    sbox 0x9a = 0xB8
    sbox 0x9b = 0x14
    sbox 0x9c = 0xDE
    sbox 0x9d = 0x5E
    sbox 0x9e = 0x0B
    sbox 0x9f = 0xDB

    sbox 0xa0 = 0xE0
    sbox 0xa1 = 0x32
    sbox 0xa2 = 0x3A
    sbox 0xa3 = 0x0A
    sbox 0xa4 = 0x49
    sbox 0xa5 = 0x06
    sbox 0xa6 = 0x24
    sbox 0xa7 = 0x5C

    sbox 0xa8 = 0xC2
    sbox 0xa9 = 0xD3
    sbox 0xaa = 0xAC
    sbox 0xab = 0x62
    sbox 0xac = 0x91
    sbox 0xad = 0x95
    sbox 0xae = 0xE4
    sbox 0xaf = 0x79

    sbox 0xb0 = 0xE7
    sbox 0xb1 = 0xC8
    sbox 0xb2 = 0x37
    sbox 0xb3 = 0x6D
    sbox 0xb4 = 0x8D
    sbox 0xb5 = 0xD5
    sbox 0xb6 = 0x4E
    sbox 0xb7 = 0xA9

    sbox 0xb8 = 0x6C
    sbox 0xb9 = 0x56
    sbox 0xba = 0xF4
    sbox 0xbb = 0xEA
    sbox 0xbc = 0x65
    sbox 0xbd = 0x7A
    sbox 0xbe = 0xAE
    sbox 0xbf = 0x08

    sbox 0xc0 = 0xBA
    sbox 0xc1 = 0x78
    sbox 0xc2 = 0x25
    sbox 0xc3 = 0x2E
    sbox 0xc4 = 0x1C
    sbox 0xc5 = 0xA6
    sbox 0xc6 = 0xB4
    sbox 0xc7 = 0xC6

    sbox 0xc8 = 0xE8
    sbox 0xc9 = 0xDD
    sbox 0xca = 0x74
    sbox 0xcb = 0x1F
    sbox 0xcc = 0x4B
    sbox 0xcd = 0xBD
    sbox 0xce = 0x8B
    sbox 0xcf = 0x8A

    sbox 0xd0 = 0x70
    sbox 0xd1 = 0x3E
    sbox 0xd2 = 0xB5
    sbox 0xd3 = 0x66
    sbox 0xd4 = 0x48
    sbox 0xd5 = 0x03
    sbox 0xd6 = 0xF6
    sbox 0xd7 = 0x0E

    sbox 0xd8 = 0x61
    sbox 0xd9 = 0x35
    sbox 0xda = 0x57
    sbox 0xdb = 0xB9
    sbox 0xdc = 0x86
    sbox 0xdd = 0xC1
    sbox 0xde = 0x1D
    sbox 0xdf = 0x9E

    sbox 0xe0 = 0xE1
    sbox 0xe1 = 0xF8
    sbox 0xe2 = 0x98
    sbox 0xe3 = 0x11
    sbox 0xe4 = 0x69
    sbox 0xe5 = 0xD9
    sbox 0xe6 = 0x8E
    sbox 0xe7 = 0x94

    sbox 0xe8 = 0x9B
    sbox 0xe9 = 0x1E
    sbox 0xea = 0x87
    sbox 0xeb = 0xE9
    sbox 0xec = 0xCE
    sbox 0xed = 0x55
    sbox 0xee = 0x28
    sbox 0xef = 0xDF

    sbox 0xf0 = 0x8C
    sbox 0xf1 = 0xA1
    sbox 0xf2 = 0x89
    sbox 0xf3 = 0x0D
    sbox 0xf4 = 0xBF
    sbox 0xf5 = 0xE6
    sbox 0xf6 = 0x42
    sbox 0xf7 = 0x68

    sbox 0xf8 = 0x41
    sbox 0xf9 = 0x99
    sbox 0xfa = 0x2D
    sbox 0xfb = 0x0F
    sbox 0xfc = 0xB0
    sbox 0xfd = 0x54
    sbox 0xfe = 0xBB
    sbox 0xff = 0x16

    {----}

    sboxRev 0x63 = 0x00
    sboxRev 0x7C = 0x01
    sboxRev 0x77 = 0x02
    sboxRev 0x7B = 0x03
    sboxRev 0xF2 = 0x04
    sboxRev 0x6B = 0x05
    sboxRev 0x6F = 0x06
    sboxRev 0xC5 = 0x07

    sboxRev 0x30 = 0x08
    sboxRev 0x01 = 0x09
    sboxRev 0x67 = 0x0a
    sboxRev 0x2B = 0x0b
    sboxRev 0xFE = 0x0c
    sboxRev 0xD7 = 0x0d
    sboxRev 0xAB = 0x0e
    sboxRev 0x76 = 0x0f

    sboxRev 0xCA = 0x10
    sboxRev 0x82 = 0x11
    sboxRev 0xC9 = 0x12
    sboxRev 0x7D = 0x13
    sboxRev 0xFA = 0x14
    sboxRev 0x59 = 0x15
    sboxRev 0x47 = 0x16
    sboxRev 0xF0 = 0x17

    sboxRev 0xAD = 0x18
    sboxRev 0xD4 = 0x19
    sboxRev 0xA2 = 0x1a
    sboxRev 0xAF = 0x1b
    sboxRev 0x9C = 0x1c
    sboxRev 0xA4 = 0x1d
    sboxRev 0x72 = 0x1e
    sboxRev 0xC0 = 0x1f

    sboxRev 0xB7 = 0x20
    sboxRev 0xFD = 0x21
    sboxRev 0x93 = 0x22
    sboxRev 0x26 = 0x23
    sboxRev 0x36 = 0x24
    sboxRev 0x3F = 0x25
    sboxRev 0xF7 = 0x26
    sboxRev 0xCC = 0x27

    sboxRev 0x34 = 0x28
    sboxRev 0xA5 = 0x29
    sboxRev 0xE5 = 0x2a
    sboxRev 0xF1 = 0x2b
    sboxRev 0x71 = 0x2c
    sboxRev 0xD8 = 0x2d
    sboxRev 0x31 = 0x2e
    sboxRev 0x15 = 0x2f

    sboxRev 0x04 = 0x30
    sboxRev 0xC7 = 0x31
    sboxRev 0x23 = 0x32
    sboxRev 0xC3 = 0x33
    sboxRev 0x18 = 0x34
    sboxRev 0x96 = 0x35
    sboxRev 0x05 = 0x36
    sboxRev 0x9A = 0x37

    sboxRev 0x07 = 0x38
    sboxRev 0x12 = 0x39
    sboxRev 0x80 = 0x3a
    sboxRev 0xE2 = 0x3b
    sboxRev 0xEB = 0x3c
    sboxRev 0x27 = 0x3d
    sboxRev 0xB2 = 0x3e
    sboxRev 0x75 = 0x3f

    sboxRev 0x09 = 0x40
    sboxRev 0x83 = 0x41
    sboxRev 0x2C = 0x42
    sboxRev 0x1A = 0x43
    sboxRev 0x1B = 0x44
    sboxRev 0x6E = 0x45
    sboxRev 0x5A = 0x46
    sboxRev 0xA0 = 0x47

    sboxRev 0x52 = 0x48
    sboxRev 0x3B = 0x49
    sboxRev 0xD6 = 0x4a
    sboxRev 0xB3 = 0x4b
    sboxRev 0x29 = 0x4c
    sboxRev 0xE3 = 0x4d
    sboxRev 0x2F = 0x4e
    sboxRev 0x84 = 0x4f

    sboxRev 0x53 = 0x50
    sboxRev 0xD1 = 0x51
    sboxRev 0x00 = 0x52
    sboxRev 0xED = 0x53
    sboxRev 0x20 = 0x54
    sboxRev 0xFC = 0x55
    sboxRev 0xB1 = 0x56
    sboxRev 0x5B = 0x57

    sboxRev 0x6A = 0x58
    sboxRev 0xCB = 0x59
    sboxRev 0xBE = 0x5a
    sboxRev 0x39 = 0x5b
    sboxRev 0x4A = 0x5c
    sboxRev 0x4C = 0x5d
    sboxRev 0x58 = 0x5e
    sboxRev 0xCF = 0x5f

    sboxRev 0xD0 = 0x60
    sboxRev 0xEF = 0x61
    sboxRev 0xAA = 0x62
    sboxRev 0xFB = 0x63
    sboxRev 0x43 = 0x64
    sboxRev 0x4D = 0x65
    sboxRev 0x33 = 0x66
    sboxRev 0x85 = 0x67

    sboxRev 0x45 = 0x68
    sboxRev 0xF9 = 0x69
    sboxRev 0x02 = 0x6a
    sboxRev 0x7F = 0x6b
    sboxRev 0x50 = 0x6c
    sboxRev 0x3C = 0x6d
    sboxRev 0x9F = 0x6e
    sboxRev 0xA8 = 0x6f

    sboxRev 0x51 = 0x70
    sboxRev 0xA3 = 0x71
    sboxRev 0x40 = 0x72
    sboxRev 0x8F = 0x73
    sboxRev 0x92 = 0x74
    sboxRev 0x9D = 0x75
    sboxRev 0x38 = 0x76
    sboxRev 0xF5 = 0x77

    sboxRev 0xBC = 0x78
    sboxRev 0xB6 = 0x79
    sboxRev 0xDA = 0x7a
    sboxRev 0x21 = 0x7b
    sboxRev 0x10 = 0x7c
    sboxRev 0xFF = 0x7d
    sboxRev 0xF3 = 0x7e
    sboxRev 0xD2 = 0x7f

    sboxRev 0xCD = 0x80
    sboxRev 0x0C = 0x81
    sboxRev 0x13 = 0x82
    sboxRev 0xEC = 0x83
    sboxRev 0x5F = 0x84
    sboxRev 0x97 = 0x85
    sboxRev 0x44 = 0x86
    sboxRev 0x17 = 0x87

    sboxRev 0xC4 = 0x88
    sboxRev 0xA7 = 0x89
    sboxRev 0x7E = 0x8a
    sboxRev 0x3D = 0x8b
    sboxRev 0x64 = 0x8c
    sboxRev 0x5D = 0x8d
    sboxRev 0x19 = 0x8e
    sboxRev 0x73 = 0x8f

    sboxRev 0x60 = 0x90
    sboxRev 0x81 = 0x91
    sboxRev 0x4F = 0x92
    sboxRev 0xDC = 0x93
    sboxRev 0x22 = 0x94
    sboxRev 0x2A = 0x95
    sboxRev 0x90 = 0x96
    sboxRev 0x88 = 0x97

    sboxRev 0x46 = 0x98
    sboxRev 0xEE = 0x99
    sboxRev 0xB8 = 0x9a
    sboxRev 0x14 = 0x9b
    sboxRev 0xDE = 0x9c
    sboxRev 0x5E = 0x9d
    sboxRev 0x0B = 0x9e
    sboxRev 0xDB = 0x9f

    sboxRev 0xE0 = 0xa0
    sboxRev 0x32 = 0xa1
    sboxRev 0x3A = 0xa2
    sboxRev 0x0A = 0xa3
    sboxRev 0x49 = 0xa4
    sboxRev 0x06 = 0xa5
    sboxRev 0x24 = 0xa6
    sboxRev 0x5C = 0xa7

    sboxRev 0xC2 = 0xa8
    sboxRev 0xD3 = 0xa9
    sboxRev 0xAC = 0xaa
    sboxRev 0x62 = 0xab
    sboxRev 0x91 = 0xac
    sboxRev 0x95 = 0xad
    sboxRev 0xE4 = 0xae
    sboxRev 0x79 = 0xaf

    sboxRev 0xE7 = 0xb0
    sboxRev 0xC8 = 0xb1
    sboxRev 0x37 = 0xb2
    sboxRev 0x6D = 0xb3
    sboxRev 0x8D = 0xb4
    sboxRev 0xD5 = 0xb5
    sboxRev 0x4E = 0xb6
    sboxRev 0xA9 = 0xb7

    sboxRev 0x6C = 0xb8
    sboxRev 0x56 = 0xb9
    sboxRev 0xF4 = 0xba
    sboxRev 0xEA = 0xbb
    sboxRev 0x65 = 0xbc
    sboxRev 0x7A = 0xbd
    sboxRev 0xAE = 0xbe
    sboxRev 0x08 = 0xbf

    sboxRev 0xBA = 0xc0
    sboxRev 0x78 = 0xc1
    sboxRev 0x25 = 0xc2
    sboxRev 0x2E = 0xc3
    sboxRev 0x1C = 0xc4
    sboxRev 0xA6 = 0xc5
    sboxRev 0xB4 = 0xc6
    sboxRev 0xC6 = 0xc7

    sboxRev 0xE8 = 0xc8
    sboxRev 0xDD = 0xc9
    sboxRev 0x74 = 0xca
    sboxRev 0x1F = 0xcb
    sboxRev 0x4B = 0xcc
    sboxRev 0xBD = 0xcd
    sboxRev 0x8B = 0xce
    sboxRev 0x8A = 0xcf

    sboxRev 0x70 = 0xd0
    sboxRev 0x3E = 0xd1
    sboxRev 0xB5 = 0xd2
    sboxRev 0x66 = 0xd3
    sboxRev 0x48 = 0xd4
    sboxRev 0x03 = 0xd5
    sboxRev 0xF6 = 0xd6
    sboxRev 0x0E = 0xd7

    sboxRev 0x61 = 0xd8
    sboxRev 0x35 = 0xd9
    sboxRev 0x57 = 0xda
    sboxRev 0xB9 = 0xdb
    sboxRev 0x86 = 0xdc
    sboxRev 0xC1 = 0xdd
    sboxRev 0x1D = 0xde
    sboxRev 0x9E = 0xdf

    sboxRev 0xE1 = 0xe0
    sboxRev 0xF8 = 0xe1
    sboxRev 0x98 = 0xe2
    sboxRev 0x11 = 0xe3
    sboxRev 0x69 = 0xe4
    sboxRev 0xD9 = 0xe5
    sboxRev 0x8E = 0xe6
    sboxRev 0x94 = 0xe7

    sboxRev 0x9B = 0xe8
    sboxRev 0x1E = 0xe9
    sboxRev 0x87 = 0xea
    sboxRev 0xE9 = 0xeb
    sboxRev 0xCE = 0xec
    sboxRev 0x55 = 0xed
    sboxRev 0x28 = 0xee
    sboxRev 0xDF = 0xef

    sboxRev 0x8C = 0xf0
    sboxRev 0xA1 = 0xf1
    sboxRev 0x89 = 0xf2
    sboxRev 0x0D = 0xf3
    sboxRev 0xBF = 0xf4
    sboxRev 0xE6 = 0xf5
    sboxRev 0x42 = 0xf6
    sboxRev 0x68 = 0xf7

    sboxRev 0x41 = 0xf8
    sboxRev 0x99 = 0xf9
    sboxRev 0x2D = 0xfa
    sboxRev 0x0F = 0xfb
    sboxRev 0xB0 = 0xfc
    sboxRev 0x54 = 0xfd
    sboxRev 0xBB = 0xfe
    sboxRev 0x16 = 0xff

    xtime :: Word32 -> Word32
    xtime x = b
    	where	a = x `shiftL` 1
    		b = if a .&. (0x0100) == 0 then a else a `xor` 0x11b

    xtimeX2 :: Word32 -> Word32
    --xtimeX2 = xtime . xtime
    xtimeX2 x = c
    	where	a = x `shiftL` 2
    		b = if a .&. (0x0200) == 0 then a else a `xor` 0x236
    		c = if b .&. (0x0100) == 0 then b else b `xor` 0x11b

    xtimeX3 :: Word32 -> Word32
    --xtimeX3 = xtime . xtime . xtime
    xtimeX3 x = d
    	where	a = x `shiftL` 3
    		b = if a .&. (0x0400) == 0 then a else a `xor` 0x46c
    		c = if b .&. (0x0200) == 0 then b else b `xor` 0x236
    		d = if c .&. (0x0100) == 0 then c else c `xor` 0x11b

    xtime03 :: Word32 -> Word32
    xtime03 x = x `xor` (xtime x)

    xtime0e :: Word32 -> Word32
    xtime0e x = xtime (x `xor` (xtime (x `xor` (xtime x))))

    xtime09 :: Word32 -> Word32
    xtime09 x = x `xor` (xtimeX3 x)

    xtime0d :: Word32 -> Word32
    xtime0d x = x `xor` (xtimeX2 (x `xor` (xtime x)))

    xtime0b :: Word32 -> Word32
    xtime0b x = x `xor` (xtime (x `xor` (xtimeX2 x)))

    generateKey :: Int -> Int -> Word32 -> Word32 -> Word32
    generateKey nk i wIminus1 wIminusNk =
    		(temp' `xor` wIminusNk)
    	where temp' =
    		if (i `mod` nk) == 0 then (subword(rotword temp)) `xor` rcon
    		else if (nk > 6) && ((i `mod` nk) == 4) then subword temp
    		else temp
    	      temp = wIminus1
    	      subword :: Word32 -> Word32
    	      subword w = (a `shiftL` 24) .|. (b `shiftL` 16) .|.
    	      		  (c `shiftL` 8) .|. d
    			  where a = sbox ((w `shiftR` 24) .&. 0xff)
    			        b = sbox ((w `shiftR` 16) .&. 0xff)
    			        c = sbox ((w `shiftR`  8) .&. 0xff)
    			        d = sbox ( w             .&. 0xff)
    	      rotword :: Word32 -> Word32
    	      rotword w = w `rotateL` 8
    	      rcon :: Word32
    	      rcon = ((fromIntegral rconMSB)::Word32) `shiftL` 24
    	      rconMSB = (iterate xtime 0x01) !! ((i `div` nk) - 1)

    wordify :: [Octet] -> [Word32]
    wordify [] = []
    wordify octets = firstWord:otherWords
    	where
    		(firstWord, otherOctets) = getWord32 octets
    		otherWords = wordify otherOctets

    generateKeys :: Int -> Int -> [Octet] -> [Word32]
    generateKeys nr nk mainKey =
    		-- assert ((nk * 4) == length mainKey) $
    		(take (4 * (nr + 1)) xs)
    	where
    		xs = (wordify mainKey) ++ (zipWith3 (generateKey nk)
    						(drop nk [0,1..])
    						(drop (nk - 1) xs)
    						xs
    					)

    subBytes :: State -> State
    subBytes (State (s00, s01, s02, s03)
    		(s10, s11, s12, s13)
    	 	(s20, s21, s22, s23)
    	 	(s30, s31, s32, s33)) =
    	  State (sbox s00, sbox s01, sbox s02, sbox s03)
     		(sbox s10, sbox s11, sbox s12, sbox s13)
    		(sbox s20, sbox s21, sbox s22, sbox s23)
    		(sbox s30, sbox s31, sbox s32, sbox s33)

    subBytesRev :: State -> State
    subBytesRev (State (s00, s01, s02, s03)
    		   (s10, s11, s12, s13)
    	 	   (s20, s21, s22, s23)
    	 	   (s30, s31, s32, s33)) =
    	  State (sboxRev s00, sboxRev s01, sboxRev s02, sboxRev s03)
      		(sboxRev s10, sboxRev s11, sboxRev s12, sboxRev s13)
      		(sboxRev s20, sboxRev s21, sboxRev s22, sboxRev s23)
      		(sboxRev s30, sboxRev s31, sboxRev s32, sboxRev s33)

    shiftRows :: State -> State
    shiftRows (State (s00, s01, s02, s03)
    		 (s10, s11, s12, s13)
    	 	 (s20, s21, s22, s23)
    	 	 (s30, s31, s32, s33)) =
    	  State (s00, s01, s02, s03)
     		(s11, s12, s13, s10)
    		(s22, s23, s20, s21)
    		(s33, s30, s31, s32)

    shiftRowsRev :: State -> State
    shiftRowsRev (State (s00, s01, s02, s03)
    		    (s10, s11, s12, s13)
    	 	    (s20, s21, s22, s23)
    	 	    (s30, s31, s32, s33)) =
    	  State (s00, s01, s02, s03)
     		(s13, s10, s11, s12)
    		(s22, s23, s20, s21)
    		(s31, s32, s33, s30)

    mixColumn:: (Word32, Word32, Word32, Word32) -> (Word32, Word32, Word32, Word32)
    mixColumn (s0,s1,s2,s3) =
    	((xtime   s0) `xor` (xtime03 s1) `xor`          s2  `xor`          s3 ,
    	          s0  `xor` (xtime   s1) `xor` (xtime03 s2) `xor`          s3 ,
    	          s0  `xor`          s1  `xor` (xtime   s2) `xor` (xtime03 s3),
    	 (xtime03 s0) `xor`          s1  `xor`          s2  `xor` (xtime   s3))

    mixColumns :: State -> State
    mixColumns (State (s00, s01, s02, s03)
    		  (s10, s11, s12, s13)
    	 	  (s20, s21, s22, s23)
    	 	  (s30, s31, s32, s33)) =
    	  State (r00, r01, r02, r03)
     		(r10, r11, r12, r13)
    		(r20, r21, r22, r23)
    		(r30, r31, r32, r33)
    	where (r00, r10, r20, r30) = mixColumn (s00, s10, s20, s30)
    	      (r01, r11, r21, r31) = mixColumn (s01, s11, s21, s31)
    	      (r02, r12, r22, r32) = mixColumn (s02, s12, s22, s32)
    	      (r03, r13, r23, r33) = mixColumn (s03, s13, s23, s33)

    mixColumnRev :: (Word32, Word32, Word32, Word32)
    		-> (Word32, Word32, Word32, Word32)
    mixColumnRev (s0,s1,s2,s3) =
    	((xtime0e s0) `xor` (xtime0b s1) `xor` (xtime0d s2) `xor` (xtime09 s3),
    	 (xtime09 s0) `xor` (xtime0e s1) `xor` (xtime0b s2) `xor` (xtime0d s3),
    	 (xtime0d s0) `xor` (xtime09 s1) `xor` (xtime0e s2) `xor` (xtime0b s3),
    	 (xtime0b s0) `xor` (xtime0d s1) `xor` (xtime09 s2) `xor` (xtime0e s3))

    mixColumnsRev :: State -> State
    mixColumnsRev (State (s00, s01, s02, s03)
    		  (s10, s11, s12, s13)
    	 	  (s20, s21, s22, s23)
    	 	  (s30, s31, s32, s33)) =
    	  State (r00, r01, r02, r03)
     		(r10, r11, r12, r13)
    		(r20, r21, r22, r23)
    		(r30, r31, r32, r33)
    	where (r00, r10, r20, r30) = mixColumnRev (s00, s10, s20, s30)
    	      (r01, r11, r21, r31) = mixColumnRev (s01, s11, s21, s31)
    	      (r02, r12, r22, r32) = mixColumnRev (s02, s12, s22, s32)
    	      (r03, r13, r23, r33) = mixColumnRev (s03, s13, s23, s33)

    addRoundKey :: State -> State -> State
    addRoundKey (State (k00, k01, k02, k03)
    		   (k10, k11, k12, k13)
    		   (k20, k21, k22, k23)
    	 	   (k30, k31, k32, k33))
    	    (State (s00, s01, s02, s03)
    		   (s10, s11, s12, s13)
    		   (s20, s21, s22, s23)
    	 	   (s30, s31, s32, s33)) =
    	  State (s00 `xor` k00, s01 `xor` k01, s02 `xor` k02, s03 `xor` k03)
     		(s10 `xor` k10, s11 `xor` k11, s12 `xor` k12, s13 `xor` k13)
    		(s20 `xor` k20, s21 `xor` k21, s22 `xor` k22, s23 `xor` k23)
    		(s30 `xor` k30, s31 `xor` k31, s32 `xor` k32, s33 `xor` k33)

    genAddRoundKey :: [Word32] -> [State -> State]
    genAddRoundKey [] = []
    genAddRoundKey (a:b:c:d:ks) = (addRoundKey k):(genAddRoundKey ks)
    	where k = State (fromIntegral s00, fromIntegral s01,
    			 fromIntegral s02, fromIntegral s03)
    			(fromIntegral s10, fromIntegral s11,
    			 fromIntegral s12, fromIntegral s13)
    			(fromIntegral s20, fromIntegral s21,
    			 fromIntegral s22, fromIntegral s23)
    			(fromIntegral s30, fromIntegral s31,
    			 fromIntegral s32, fromIntegral s33)
    	      [s00, s10, s20, s30] = putWord32 a
    	      [s01, s11, s21, s31] = putWord32 b
    	      [s02, s12, s22, s32] = putWord32 c
    	      [s03, s13, s23, s33] = putWord32 d

    getWord32 :: [Octet] -> (Word32, [Octet])
    getWord32 (a:b:c:d:xs) = (x, xs)
    	where
    		x = ((fromIntegral a) `shiftL` 24) .|.
    		    ((fromIntegral b) `shiftL` 16) .|.
    		    ((fromIntegral c) `shiftL`  8) .|.
    		    ((fromIntegral d)            )

    putWord32 :: Word32 -> [Octet]
    --a bit slower putWord32 x = map fromIntegral [a,b,c,d]
    putWord32 x = [fromIntegral a, fromIntegral b, fromIntegral c, fromIntegral d]
    	where
    		a = (x `shiftR` 24)
    		b = (x `shiftR` 16) .&. 255
    		c = (x `shiftR`  8) .&. 255
    		d = (x            ) .&. 255

    {-
    testGenerateKeys128 :: Test
    testGenerateKeys128 =
    	let key = [0x2b, 0x7e, 0x15, 0x16,
    		   0x28, 0xae, 0xd2, 0xa6,
    		   0xab, 0xf7, 0x15, 0x88,
    		   0x09, 0xcf, 0x4f, 0x3c]
    	    expected = [0x2b7e1516, 0x28aed2a6, 0xabf71588, 0x09cf4f3c,
    	    		0xa0fafe17, 0x88542cb1, 0x23a33939, 0x2a6c7605,
    			0xf2c295f2, 0x7a96b943, 0x5935807a, 0x7359f67f,
    			0x3d80477d, 0x4716fe3e, 0x1e237e44, 0x6d7a883b,
    			0xef44a541, 0xa8525b7f, 0xb671253b, 0xdb0bad00,
    			0xd4d1c6f8, 0x7c839d87, 0xcaf2b8bc, 0x11f915bc,
    			0x6d88a37a, 0x110b3efd, 0xdbf98641, 0xca0093fd,
    			0x4e54f70e, 0x5f5fc9f3, 0x84a64fb2, 0x4ea6dc4f,
    			0xead27321, 0xb58dbad2, 0x312bf560, 0x7f8d292f,
    			0xac7766f3, 0x19fadc21, 0x28d12941, 0x575c006e,
    			0xd014f9a8, 0xc9ee2589, 0xe13f0cc8, 0xb6630ca6
    			]
    	in TestCase (do
    		assertEqual "" expected (generateKeys 10 4 key)
    	)

    testGenerateKeys192 :: Test
    testGenerateKeys192 =
    	let key = [0x8e, 0x73, 0xb0, 0xf7,
    		   0xda, 0x0e, 0x64, 0x52,
    		   0xc8, 0x10, 0xf3, 0x2b,
    		   0x80, 0x90, 0x79, 0xe5,
    		   0x62, 0xf8, 0xea, 0xd2,
    		   0x52, 0x2c, 0x6b, 0x7b]
    	    expected = [0x8e73b0f7, 0xda0e6452, 0xc810f32b, 0x809079e5,
    	    		0x62f8ead2, 0x522c6b7b, 0xfe0c91f7, 0x2402f5a5,
    			0xec12068e, 0x6c827f6b, 0x0e7a95b9, 0x5c56fec2,
    			0x4db7b4bd, 0x69b54118, 0x85a74796, 0xe92538fd,
    			0xe75fad44, 0xbb095386, 0x485af057, 0x21efb14f
    			]
    	in TestCase (do
    		assertEqual "" expected
    			(take (length expected) (generateKeys 12 6 key))
    	)

    testGenerateKeys256 :: Test
    testGenerateKeys256 =
    	let key = [0x60, 0x3d, 0xeb, 0x10,
    		   0x15, 0xca, 0x71, 0xbe,
    		   0x2b, 0x73, 0xae, 0xf0,
    		   0x85, 0x7d, 0x77, 0x81,
    		   0x1f, 0x35, 0x2c, 0x07,
    		   0x3b, 0x61, 0x08, 0xd7,
    		   0x2d, 0x98, 0x10, 0xa3,
    		   0x09, 0x14, 0xdf, 0xf4]
    	    expected = [0x603deb10, 0x15ca71be, 0x2b73aef0, 0x857d7781,
    	    		0x1f352c07, 0x3b6108d7, 0x2d9810a3, 0x0914dff4,
    			0x9ba35411, 0x8e6925af, 0xa51a8b5f, 0x2067fcde,
    			0xa8b09c1a, 0x93d194cd, 0xbe49846e, 0xb75d5b9a,
    			0xd59aecb8, 0x5bf3c917, 0xfee94248, 0xde8ebe96
    			]
    	in TestCase (do
    		assertEqual "" expected
    			(take (length expected) (generateKeys 14 8 key))
    	)

    testAes128 :: Test
    testAes128 =
    	let key = [0x2b, 0x7e, 0x15, 0x16,
    		   0x28, 0xae, 0xd2, 0xa6,
    		   0xab, 0xf7, 0x15, 0x88,
    		   0x09, 0xcf, 0x4f, 0x3c]
    	    input = [0x32, 0x43, 0xf6, 0xa8,
    	    	     0x88, 0x5a, 0x30, 0x8d,
    		     0x31, 0x31, 0x98, 0xa2,
    		     0xe0, 0x37, 0x07, 0x34]
    	    output = [0x39, 0x25, 0x84, 0x1d,
    	    	      0x02, 0xdc, 0x09, 0xfb,
    		      0xdc, 0x11, 0x85, 0x97,
    		      0x19, 0x6a, 0x0b, 0x32]
    	in TestCase (do
    		assertEqual "encrypt test" output (aes128Encrypt key input)
    		assertEqual "encrypt/decrypt test" input
    				(aes128Decrypt key (aes128Encrypt key input))
    	)

    testAesRandom :: Test
    testAesRandom =
    	TestCase (do
    		key128 <- getRandomOctets 16
    		key192 <- getRandomOctets 24
    		key256 <- getRandomOctets 32
    		msg <- getRandomOctets 16
    		assertEqual "aes128" msg
    			(aes128Decrypt key128 (aes128Encrypt key128 msg))
    		assertEqual "aes192" msg
    			(aes192Decrypt key192 (aes192Encrypt key192 msg))
    		assertEqual "aes256" msg
    			(aes256Decrypt key256 (aes256Encrypt key256 msg))
    	)

    -- | HUnit tests
    tests :: Test
    tests = TestList [
    		TestLabel "testGenerateKeys128" testGenerateKeys128,
    		TestLabel "testGenerateKeys192" testGenerateKeys192,
    		TestLabel "testGenerateKeys256" testGenerateKeys256,
    		TestLabel "testAes128" testAes128,
    		TestLabel "testAesRandom" testAesRandom
    	]
    -}