AES Decrypt
The Advanced Encryption Standard (AES) also known as Rijndael is a specification for the encryption of electronic data.
For AES Encrypt algorithm click here.
/*****Please include following header files*****/
// stdint.h
/***********************************************/
const uint8_t aes_sbox[16][16] = {
0x63,0x7C,0x77,0x7B,0xF2,0x6B,0x6F,0xC5,0x30,0x01,0x67,0x2B,0xFE,0xD7,0xAB,0x76,
0xCA,0x82,0xC9,0x7D,0xFA,0x59,0x47,0xF0,0xAD,0xD4,0xA2,0xAF,0x9C,0xA4,0x72,0xC0,
0xB7,0xFD,0x93,0x26,0x36,0x3F,0xF7,0xCC,0x34,0xA5,0xE5,0xF1,0x71,0xD8,0x31,0x15,
0x04,0xC7,0x23,0xC3,0x18,0x96,0x05,0x9A,0x07,0x12,0x80,0xE2,0xEB,0x27,0xB2,0x75,
0x09,0x83,0x2C,0x1A,0x1B,0x6E,0x5A,0xA0,0x52,0x3B,0xD6,0xB3,0x29,0xE3,0x2F,0x84,
0x53,0xD1,0x00,0xED,0x20,0xFC,0xB1,0x5B,0x6A,0xCB,0xBE,0x39,0x4A,0x4C,0x58,0xCF,
0xD0,0xEF,0xAA,0xFB,0x43,0x4D,0x33,0x85,0x45,0xF9,0x02,0x7F,0x50,0x3C,0x9F,0xA8,
0x51,0xA3,0x40,0x8F,0x92,0x9D,0x38,0xF5,0xBC,0xB6,0xDA,0x21,0x10,0xFF,0xF3,0xD2,
0xCD,0x0C,0x13,0xEC,0x5F,0x97,0x44,0x17,0xC4,0xA7,0x7E,0x3D,0x64,0x5D,0x19,0x73,
0x60,0x81,0x4F,0xDC,0x22,0x2A,0x90,0x88,0x46,0xEE,0xB8,0x14,0xDE,0x5E,0x0B,0xDB,
0xE0,0x32,0x3A,0x0A,0x49,0x06,0x24,0x5C,0xC2,0xD3,0xAC,0x62,0x91,0x95,0xE4,0x79,
0xE7,0xC8,0x37,0x6D,0x8D,0xD5,0x4E,0xA9,0x6C,0x56,0xF4,0xEA,0x65,0x7A,0xAE,0x08,
0xBA,0x78,0x25,0x2E,0x1C,0xA6,0xB4,0xC6,0xE8,0xDD,0x74,0x1F,0x4B,0xBD,0x8B,0x8A,
0x70,0x3E,0xB5,0x66,0x48,0x03,0xF6,0x0E,0x61,0x35,0x57,0xB9,0x86,0xC1,0x1D,0x9E,
0xE1,0xF8,0x98,0x11,0x69,0xD9,0x8E,0x94,0x9B,0x1E,0x87,0xE9,0xCE,0x55,0x28,0xDF,
0x8C,0xA1,0x89,0x0D,0xBF,0xE6,0x42,0x68,0x41,0x99,0x2D,0x0F,0xB0,0x54,0xBB,0x16
};
const uint8_t aes_invsbox[16][16] = {
0x52,0x09,0x6A,0xD5,0x30,0x36,0xA5,0x38,0xBF,0x40,0xA3,0x9E,0x81,0xF3,0xD7,0xFB,
0x7C,0xE3,0x39,0x82,0x9B,0x2F,0xFF,0x87,0x34,0x8E,0x43,0x44,0xC4,0xDE,0xE9,0xCB,
0x54,0x7B,0x94,0x32,0xA6,0xC2,0x23,0x3D,0xEE,0x4C,0x95,0x0B,0x42,0xFA,0xC3,0x4E,
0x08,0x2E,0xA1,0x66,0x28,0xD9,0x24,0xB2,0x76,0x5B,0xA2,0x49,0x6D,0x8B,0xD1,0x25,
0x72,0xF8,0xF6,0x64,0x86,0x68,0x98,0x16,0xD4,0xA4,0x5C,0xCC,0x5D,0x65,0xB6,0x92,
0x6C,0x70,0x48,0x50,0xFD,0xED,0xB9,0xDA,0x5E,0x15,0x46,0x57,0xA7,0x8D,0x9D,0x84,
0x90,0xD8,0xAB,0x00,0x8C,0xBC,0xD3,0x0A,0xF7,0xE4,0x58,0x05,0xB8,0xB3,0x45,0x06,
0xD0,0x2C,0x1E,0x8F,0xCA,0x3F,0x0F,0x02,0xC1,0xAF,0xBD,0x03,0x01,0x13,0x8A,0x6B,
0x3A,0x91,0x11,0x41,0x4F,0x67,0xDC,0xEA,0x97,0xF2,0xCF,0xCE,0xF0,0xB4,0xE6,0x73,
0x96,0xAC,0x74,0x22,0xE7,0xAD,0x35,0x85,0xE2,0xF9,0x37,0xE8,0x1C,0x75,0xDF,0x6E,
0x47,0xF1,0x1A,0x71,0x1D,0x29,0xC5,0x89,0x6F,0xB7,0x62,0x0E,0xAA,0x18,0xBE,0x1B,
0xFC,0x56,0x3E,0x4B,0xC6,0xD2,0x79,0x20,0x9A,0xDB,0xC0,0xFE,0x78,0xCD,0x5A,0xF4,
0x1F,0xDD,0xA8,0x33,0x88,0x07,0xC7,0x31,0xB1,0x12,0x10,0x59,0x27,0x80,0xEC,0x5F,
0x60,0x51,0x7F,0xA9,0x19,0xB5,0x4A,0x0D,0x2D,0xE5,0x7A,0x9F,0x93,0xC9,0x9C,0xEF,
0xA0,0xE0,0x3B,0x4D,0xAE,0x2A,0xF5,0xB0,0xC8,0xEB,0xBB,0x3C,0x83,0x53,0x99,0x61,
0x17,0x2B,0x04,0x7E,0xBA,0x77,0xD6,0x26,0xE1,0x69,0x14,0x63,0x55,0x21,0x0C,0x7D
};
uint8_t gf_mul[256][6] = {
{ 0x00,0x00,0x00,0x00,0x00,0x00 },{ 0x02,0x03,0x09,0x0b,0x0d,0x0e },
{ 0x04,0x06,0x12,0x16,0x1a,0x1c },{ 0x06,0x05,0x1b,0x1d,0x17,0x12 },
{ 0x08,0x0c,0x24,0x2c,0x34,0x38 },{ 0x0a,0x0f,0x2d,0x27,0x39,0x36 },
{ 0x0c,0x0a,0x36,0x3a,0x2e,0x24 },{ 0x0e,0x09,0x3f,0x31,0x23,0x2a },
{ 0x10,0x18,0x48,0x58,0x68,0x70 },{ 0x12,0x1b,0x41,0x53,0x65,0x7e },
{ 0x14,0x1e,0x5a,0x4e,0x72,0x6c },{ 0x16,0x1d,0x53,0x45,0x7f,0x62 },
{ 0x18,0x14,0x6c,0x74,0x5c,0x48 },{ 0x1a,0x17,0x65,0x7f,0x51,0x46 },
{ 0x1c,0x12,0x7e,0x62,0x46,0x54 },{ 0x1e,0x11,0x77,0x69,0x4b,0x5a },
{ 0x20,0x30,0x90,0xb0,0xd0,0xe0 },{ 0x22,0x33,0x99,0xbb,0xdd,0xee },
{ 0x24,0x36,0x82,0xa6,0xca,0xfc },{ 0x26,0x35,0x8b,0xad,0xc7,0xf2 },
{ 0x28,0x3c,0xb4,0x9c,0xe4,0xd8 },{ 0x2a,0x3f,0xbd,0x97,0xe9,0xd6 },
{ 0x2c,0x3a,0xa6,0x8a,0xfe,0xc4 },{ 0x2e,0x39,0xaf,0x81,0xf3,0xca },
{ 0x30,0x28,0xd8,0xe8,0xb8,0x90 },{ 0x32,0x2b,0xd1,0xe3,0xb5,0x9e },
{ 0x34,0x2e,0xca,0xfe,0xa2,0x8c },{ 0x36,0x2d,0xc3,0xf5,0xaf,0x82 },
{ 0x38,0x24,0xfc,0xc4,0x8c,0xa8 },{ 0x3a,0x27,0xf5,0xcf,0x81,0xa6 },
{ 0x3c,0x22,0xee,0xd2,0x96,0xb4 },{ 0x3e,0x21,0xe7,0xd9,0x9b,0xba },
{ 0x40,0x60,0x3b,0x7b,0xbb,0xdb },{ 0x42,0x63,0x32,0x70,0xb6,0xd5 },
{ 0x44,0x66,0x29,0x6d,0xa1,0xc7 },{ 0x46,0x65,0x20,0x66,0xac,0xc9 },
{ 0x48,0x6c,0x1f,0x57,0x8f,0xe3 },{ 0x4a,0x6f,0x16,0x5c,0x82,0xed },
{ 0x4c,0x6a,0x0d,0x41,0x95,0xff },{ 0x4e,0x69,0x04,0x4a,0x98,0xf1 },
{ 0x50,0x78,0x73,0x23,0xd3,0xab },{ 0x52,0x7b,0x7a,0x28,0xde,0xa5 },
{ 0x54,0x7e,0x61,0x35,0xc9,0xb7 },{ 0x56,0x7d,0x68,0x3e,0xc4,0xb9 },
{ 0x58,0x74,0x57,0x0f,0xe7,0x93 },{ 0x5a,0x77,0x5e,0x04,0xea,0x9d },
{ 0x5c,0x72,0x45,0x19,0xfd,0x8f },{ 0x5e,0x71,0x4c,0x12,0xf0,0x81 },
{ 0x60,0x50,0xab,0xcb,0x6b,0x3b },{ 0x62,0x53,0xa2,0xc0,0x66,0x35 },
{ 0x64,0x56,0xb9,0xdd,0x71,0x27 },{ 0x66,0x55,0xb0,0xd6,0x7c,0x29 },
{ 0x68,0x5c,0x8f,0xe7,0x5f,0x03 },{ 0x6a,0x5f,0x86,0xec,0x52,0x0d },
{ 0x6c,0x5a,0x9d,0xf1,0x45,0x1f },{ 0x6e,0x59,0x94,0xfa,0x48,0x11 },
{ 0x70,0x48,0xe3,0x93,0x03,0x4b },{ 0x72,0x4b,0xea,0x98,0x0e,0x45 },
{ 0x74,0x4e,0xf1,0x85,0x19,0x57 },{ 0x76,0x4d,0xf8,0x8e,0x14,0x59 },
{ 0x78,0x44,0xc7,0xbf,0x37,0x73 },{ 0x7a,0x47,0xce,0xb4,0x3a,0x7d },
{ 0x7c,0x42,0xd5,0xa9,0x2d,0x6f },{ 0x7e,0x41,0xdc,0xa2,0x20,0x61 },
{ 0x80,0xc0,0x76,0xf6,0x6d,0xad },{ 0x82,0xc3,0x7f,0xfd,0x60,0xa3 },
{ 0x84,0xc6,0x64,0xe0,0x77,0xb1 },{ 0x86,0xc5,0x6d,0xeb,0x7a,0xbf },
{ 0x88,0xcc,0x52,0xda,0x59,0x95 },{ 0x8a,0xcf,0x5b,0xd1,0x54,0x9b },
{ 0x8c,0xca,0x40,0xcc,0x43,0x89 },{ 0x8e,0xc9,0x49,0xc7,0x4e,0x87 },
{ 0x90,0xd8,0x3e,0xae,0x05,0xdd },{ 0x92,0xdb,0x37,0xa5,0x08,0xd3 },
{ 0x94,0xde,0x2c,0xb8,0x1f,0xc1 },{ 0x96,0xdd,0x25,0xb3,0x12,0xcf },
{ 0x98,0xd4,0x1a,0x82,0x31,0xe5 },{ 0x9a,0xd7,0x13,0x89,0x3c,0xeb },
{ 0x9c,0xd2,0x08,0x94,0x2b,0xf9 },{ 0x9e,0xd1,0x01,0x9f,0x26,0xf7 },
{ 0xa0,0xf0,0xe6,0x46,0xbd,0x4d },{ 0xa2,0xf3,0xef,0x4d,0xb0,0x43 },
{ 0xa4,0xf6,0xf4,0x50,0xa7,0x51 },{ 0xa6,0xf5,0xfd,0x5b,0xaa,0x5f },
{ 0xa8,0xfc,0xc2,0x6a,0x89,0x75 },{ 0xaa,0xff,0xcb,0x61,0x84,0x7b },
{ 0xac,0xfa,0xd0,0x7c,0x93,0x69 },{ 0xae,0xf9,0xd9,0x77,0x9e,0x67 },
{ 0xb0,0xe8,0xae,0x1e,0xd5,0x3d },{ 0xb2,0xeb,0xa7,0x15,0xd8,0x33 },
{ 0xb4,0xee,0xbc,0x08,0xcf,0x21 },{ 0xb6,0xed,0xb5,0x03,0xc2,0x2f },
{ 0xb8,0xe4,0x8a,0x32,0xe1,0x05 },{ 0xba,0xe7,0x83,0x39,0xec,0x0b },
{ 0xbc,0xe2,0x98,0x24,0xfb,0x19 },{ 0xbe,0xe1,0x91,0x2f,0xf6,0x17 },
{ 0xc0,0xa0,0x4d,0x8d,0xd6,0x76 },{ 0xc2,0xa3,0x44,0x86,0xdb,0x78 },
{ 0xc4,0xa6,0x5f,0x9b,0xcc,0x6a },{ 0xc6,0xa5,0x56,0x90,0xc1,0x64 },
{ 0xc8,0xac,0x69,0xa1,0xe2,0x4e },{ 0xca,0xaf,0x60,0xaa,0xef,0x40 },
{ 0xcc,0xaa,0x7b,0xb7,0xf8,0x52 },{ 0xce,0xa9,0x72,0xbc,0xf5,0x5c },
{ 0xd0,0xb8,0x05,0xd5,0xbe,0x06 },{ 0xd2,0xbb,0x0c,0xde,0xb3,0x08 },
{ 0xd4,0xbe,0x17,0xc3,0xa4,0x1a },{ 0xd6,0xbd,0x1e,0xc8,0xa9,0x14 },
{ 0xd8,0xb4,0x21,0xf9,0x8a,0x3e },{ 0xda,0xb7,0x28,0xf2,0x87,0x30 },
{ 0xdc,0xb2,0x33,0xef,0x90,0x22 },{ 0xde,0xb1,0x3a,0xe4,0x9d,0x2c },
{ 0xe0,0x90,0xdd,0x3d,0x06,0x96 },{ 0xe2,0x93,0xd4,0x36,0x0b,0x98 },
{ 0xe4,0x96,0xcf,0x2b,0x1c,0x8a },{ 0xe6,0x95,0xc6,0x20,0x11,0x84 },
{ 0xe8,0x9c,0xf9,0x11,0x32,0xae },{ 0xea,0x9f,0xf0,0x1a,0x3f,0xa0 },
{ 0xec,0x9a,0xeb,0x07,0x28,0xb2 },{ 0xee,0x99,0xe2,0x0c,0x25,0xbc },
{ 0xf0,0x88,0x95,0x65,0x6e,0xe6 },{ 0xf2,0x8b,0x9c,0x6e,0x63,0xe8 },
{ 0xf4,0x8e,0x87,0x73,0x74,0xfa },{ 0xf6,0x8d,0x8e,0x78,0x79,0xf4 },
{ 0xf8,0x84,0xb1,0x49,0x5a,0xde },{ 0xfa,0x87,0xb8,0x42,0x57,0xd0 },
{ 0xfc,0x82,0xa3,0x5f,0x40,0xc2 },{ 0xfe,0x81,0xaa,0x54,0x4d,0xcc },
{ 0x1b,0x9b,0xec,0xf7,0xda,0x41 },{ 0x19,0x98,0xe5,0xfc,0xd7,0x4f },
{ 0x1f,0x9d,0xfe,0xe1,0xc0,0x5d },{ 0x1d,0x9e,0xf7,0xea,0xcd,0x53 },
{ 0x13,0x97,0xc8,0xdb,0xee,0x79 },{ 0x11,0x94,0xc1,0xd0,0xe3,0x77 },
{ 0x17,0x91,0xda,0xcd,0xf4,0x65 },{ 0x15,0x92,0xd3,0xc6,0xf9,0x6b },
{ 0x0b,0x83,0xa4,0xaf,0xb2,0x31 },{ 0x09,0x80,0xad,0xa4,0xbf,0x3f },
{ 0x0f,0x85,0xb6,0xb9,0xa8,0x2d },{ 0x0d,0x86,0xbf,0xb2,0xa5,0x23 },
{ 0x03,0x8f,0x80,0x83,0x86,0x09 },{ 0x01,0x8c,0x89,0x88,0x8b,0x07 },
{ 0x07,0x89,0x92,0x95,0x9c,0x15 },{ 0x05,0x8a,0x9b,0x9e,0x91,0x1b },
{ 0x3b,0xab,0x7c,0x47,0x0a,0xa1 },{ 0x39,0xa8,0x75,0x4c,0x07,0xaf },
{ 0x3f,0xad,0x6e,0x51,0x10,0xbd },{ 0x3d,0xae,0x67,0x5a,0x1d,0xb3 },
{ 0x33,0xa7,0x58,0x6b,0x3e,0x99 },{ 0x31,0xa4,0x51,0x60,0x33,0x97 },
{ 0x37,0xa1,0x4a,0x7d,0x24,0x85 },{ 0x35,0xa2,0x43,0x76,0x29,0x8b },
{ 0x2b,0xb3,0x34,0x1f,0x62,0xd1 },{ 0x29,0xb0,0x3d,0x14,0x6f,0xdf },
{ 0x2f,0xb5,0x26,0x09,0x78,0xcd },{ 0x2d,0xb6,0x2f,0x02,0x75,0xc3 },
{ 0x23,0xbf,0x10,0x33,0x56,0xe9 },{ 0x21,0xbc,0x19,0x38,0x5b,0xe7 },
{ 0x27,0xb9,0x02,0x25,0x4c,0xf5 },{ 0x25,0xba,0x0b,0x2e,0x41,0xfb },
{ 0x5b,0xfb,0xd7,0x8c,0x61,0x9a },{ 0x59,0xf8,0xde,0x87,0x6c,0x94 },
{ 0x5f,0xfd,0xc5,0x9a,0x7b,0x86 },{ 0x5d,0xfe,0xcc,0x91,0x76,0x88 },
{ 0x53,0xf7,0xf3,0xa0,0x55,0xa2 },{ 0x51,0xf4,0xfa,0xab,0x58,0xac },
{ 0x57,0xf1,0xe1,0xb6,0x4f,0xbe },{ 0x55,0xf2,0xe8,0xbd,0x42,0xb0 },
{ 0x4b,0xe3,0x9f,0xd4,0x09,0xea },{ 0x49,0xe0,0x96,0xdf,0x04,0xe4 },
{ 0x4f,0xe5,0x8d,0xc2,0x13,0xf6 },{ 0x4d,0xe6,0x84,0xc9,0x1e,0xf8 },
{ 0x43,0xef,0xbb,0xf8,0x3d,0xd2 },{ 0x41,0xec,0xb2,0xf3,0x30,0xdc },
{ 0x47,0xe9,0xa9,0xee,0x27,0xce },{ 0x45,0xea,0xa0,0xe5,0x2a,0xc0 },
{ 0x7b,0xcb,0x47,0x3c,0xb1,0x7a },{ 0x79,0xc8,0x4e,0x37,0xbc,0x74 },
{ 0x7f,0xcd,0x55,0x2a,0xab,0x66 },{ 0x7d,0xce,0x5c,0x21,0xa6,0x68 },
{ 0x73,0xc7,0x63,0x10,0x85,0x42 },{ 0x71,0xc4,0x6a,0x1b,0x88,0x4c },
{ 0x77,0xc1,0x71,0x06,0x9f,0x5e },{ 0x75,0xc2,0x78,0x0d,0x92,0x50 },
{ 0x6b,0xd3,0x0f,0x64,0xd9,0x0a },{ 0x69,0xd0,0x06,0x6f,0xd4,0x04 },
{ 0x6f,0xd5,0x1d,0x72,0xc3,0x16 },{ 0x6d,0xd6,0x14,0x79,0xce,0x18 },
{ 0x63,0xdf,0x2b,0x48,0xed,0x32 },{ 0x61,0xdc,0x22,0x43,0xe0,0x3c },
{ 0x67,0xd9,0x39,0x5e,0xf7,0x2e },{ 0x65,0xda,0x30,0x55,0xfa,0x20 },
{ 0x9b,0x5b,0x9a,0x01,0xb7,0xec },{ 0x99,0x58,0x93,0x0a,0xba,0xe2 },
{ 0x9f,0x5d,0x88,0x17,0xad,0xf0 },{ 0x9d,0x5e,0x81,0x1c,0xa0,0xfe },
{ 0x93,0x57,0xbe,0x2d,0x83,0xd4 },{ 0x91,0x54,0xb7,0x26,0x8e,0xda },
{ 0x97,0x51,0xac,0x3b,0x99,0xc8 },{ 0x95,0x52,0xa5,0x30,0x94,0xc6 },
{ 0x8b,0x43,0xd2,0x59,0xdf,0x9c },{ 0x89,0x40,0xdb,0x52,0xd2,0x92 },
{ 0x8f,0x45,0xc0,0x4f,0xc5,0x80 },{ 0x8d,0x46,0xc9,0x44,0xc8,0x8e },
{ 0x83,0x4f,0xf6,0x75,0xeb,0xa4 },{ 0x81,0x4c,0xff,0x7e,0xe6,0xaa },
{ 0x87,0x49,0xe4,0x63,0xf1,0xb8 },{ 0x85,0x4a,0xed,0x68,0xfc,0xb6 },
{ 0xbb,0x6b,0x0a,0xb1,0x67,0x0c },{ 0xb9,0x68,0x03,0xba,0x6a,0x02 },
{ 0xbf,0x6d,0x18,0xa7,0x7d,0x10 },{ 0xbd,0x6e,0x11,0xac,0x70,0x1e },
{ 0xb3,0x67,0x2e,0x9d,0x53,0x34 },{ 0xb1,0x64,0x27,0x96,0x5e,0x3a },
{ 0xb7,0x61,0x3c,0x8b,0x49,0x28 },{ 0xb5,0x62,0x35,0x80,0x44,0x26 },
{ 0xab,0x73,0x42,0xe9,0x0f,0x7c },{ 0xa9,0x70,0x4b,0xe2,0x02,0x72 },
{ 0xaf,0x75,0x50,0xff,0x15,0x60 },{ 0xad,0x76,0x59,0xf4,0x18,0x6e },
{ 0xa3,0x7f,0x66,0xc5,0x3b,0x44 },{ 0xa1,0x7c,0x6f,0xce,0x36,0x4a },
{ 0xa7,0x79,0x74,0xd3,0x21,0x58 },{ 0xa5,0x7a,0x7d,0xd8,0x2c,0x56 },
{ 0xdb,0x3b,0xa1,0x7a,0x0c,0x37 },{ 0xd9,0x38,0xa8,0x71,0x01,0x39 },
{ 0xdf,0x3d,0xb3,0x6c,0x16,0x2b },{ 0xdd,0x3e,0xba,0x67,0x1b,0x25 },
{ 0xd3,0x37,0x85,0x56,0x38,0x0f },{ 0xd1,0x34,0x8c,0x5d,0x35,0x01 },
{ 0xd7,0x31,0x97,0x40,0x22,0x13 },{ 0xd5,0x32,0x9e,0x4b,0x2f,0x1d },
{ 0xcb,0x23,0xe9,0x22,0x64,0x47 },{ 0xc9,0x20,0xe0,0x29,0x69,0x49 },
{ 0xcf,0x25,0xfb,0x34,0x7e,0x5b },{ 0xcd,0x26,0xf2,0x3f,0x73,0x55 },
{ 0xc3,0x2f,0xcd,0x0e,0x50,0x7f },{ 0xc1,0x2c,0xc4,0x05,0x5d,0x71 },
{ 0xc7,0x29,0xdf,0x18,0x4a,0x63 },{ 0xc5,0x2a,0xd6,0x13,0x47,0x6d },
{ 0xfb,0x0b,0x31,0xca,0xdc,0xd7 },{ 0xf9,0x08,0x38,0xc1,0xd1,0xd9 },
{ 0xff,0x0d,0x23,0xdc,0xc6,0xcb },{ 0xfd,0x0e,0x2a,0xd7,0xcb,0xc5 },
{ 0xf3,0x07,0x15,0xe6,0xe8,0xef },{ 0xf1,0x04,0x1c,0xed,0xe5,0xe1 },
{ 0xf7,0x01,0x07,0xf0,0xf2,0xf3 },{ 0xf5,0x02,0x0e,0xfb,0xff,0xfd },
{ 0xeb,0x13,0x79,0x92,0xb4,0xa7 },{ 0xe9,0x10,0x70,0x99,0xb9,0xa9 },
{ 0xef,0x15,0x6b,0x84,0xae,0xbb },{ 0xed,0x16,0x62,0x8f,0xa3,0xb5 },
{ 0xe3,0x1f,0x5d,0xbe,0x80,0x9f },{ 0xe1,0x1c,0x54,0xb5,0x8d,0x91 },
{ 0xe7,0x19,0x4f,0xa8,0x9a,0x83 },{ 0xe5,0x1a,0x46,0xa3,0x97,0x8d }
};
void AddRoundKey(uint8_t state[][4], uint32_t w[])
{
uint8_t subkey[4];
subkey[0] = w[0] >> 24;
subkey[1] = w[0] >> 16;
subkey[2] = w[0] >> 8;
subkey[3] = w[0];
state[0][0] ^= subkey[0];
state[1][0] ^= subkey[1];
state[2][0] ^= subkey[2];
state[3][0] ^= subkey[3];
subkey[0] = w[1] >> 24;
subkey[1] = w[1] >> 16;
subkey[2] = w[1] >> 8;
subkey[3] = w[1];
state[0][1] ^= subkey[0];
state[1][1] ^= subkey[1];
state[2][1] ^= subkey[2];
state[3][1] ^= subkey[3];
subkey[0] = w[2] >> 24;
subkey[1] = w[2] >> 16;
subkey[2] = w[2] >> 8;
subkey[3] = w[2];
state[0][2] ^= subkey[0];
state[1][2] ^= subkey[1];
state[2][2] ^= subkey[2];
state[3][2] ^= subkey[3];
subkey[0] = w[3] >> 24;
subkey[1] = w[3] >> 16;
subkey[2] = w[3] >> 8;
subkey[3] = w[3];
state[0][3] ^= subkey[0];
state[1][3] ^= subkey[1];
state[2][3] ^= subkey[2];
state[3][3] ^= subkey[3];
}
void InvSubBytes(uint8_t state[][4])
{
state[0][0] = aes_invsbox[state[0][0] >> 4][state[0][0] & 0x0F];
state[0][1] = aes_invsbox[state[0][1] >> 4][state[0][1] & 0x0F];
state[0][2] = aes_invsbox[state[0][2] >> 4][state[0][2] & 0x0F];
state[0][3] = aes_invsbox[state[0][3] >> 4][state[0][3] & 0x0F];
state[1][0] = aes_invsbox[state[1][0] >> 4][state[1][0] & 0x0F];
state[1][1] = aes_invsbox[state[1][1] >> 4][state[1][1] & 0x0F];
state[1][2] = aes_invsbox[state[1][2] >> 4][state[1][2] & 0x0F];
state[1][3] = aes_invsbox[state[1][3] >> 4][state[1][3] & 0x0F];
state[2][0] = aes_invsbox[state[2][0] >> 4][state[2][0] & 0x0F];
state[2][1] = aes_invsbox[state[2][1] >> 4][state[2][1] & 0x0F];
state[2][2] = aes_invsbox[state[2][2] >> 4][state[2][2] & 0x0F];
state[2][3] = aes_invsbox[state[2][3] >> 4][state[2][3] & 0x0F];
state[3][0] = aes_invsbox[state[3][0] >> 4][state[3][0] & 0x0F];
state[3][1] = aes_invsbox[state[3][1] >> 4][state[3][1] & 0x0F];
state[3][2] = aes_invsbox[state[3][2] >> 4][state[3][2] & 0x0F];
state[3][3] = aes_invsbox[state[3][3] >> 4][state[3][3] & 0x0F];
}
void InvShiftRows(uint8_t state[][4])
{
int t;
t = state[1][3];
state[1][3] = state[1][2];
state[1][2] = state[1][1];
state[1][1] = state[1][0];
state[1][0] = t;
t = state[2][3];
state[2][3] = state[2][1];
state[2][1] = t;
t = state[2][2];
state[2][2] = state[2][0];
state[2][0] = t;
t = state[3][3];
state[3][3] = state[3][0];
state[3][0] = state[3][1];
state[3][1] = state[3][2];
state[3][2] = t;
}
void InvMixColumns(uint8_t state[][4])
{
int idx;
uint8_t col[4], t;
col[0] = state[0][0];
col[1] = state[1][0];
col[2] = state[2][0];
col[3] = state[3][0];
state[0][0] = gf_mul[col[0]][5];
state[0][0] ^= gf_mul[col[1]][3];
state[0][0] ^= gf_mul[col[2]][4];
state[0][0] ^= gf_mul[col[3]][2];
state[1][0] = gf_mul[col[0]][2];
state[1][0] ^= gf_mul[col[1]][5];
state[1][0] ^= gf_mul[col[2]][3];
state[1][0] ^= gf_mul[col[3]][4];
state[2][0] = gf_mul[col[0]][4];
state[2][0] ^= gf_mul[col[1]][2];
state[2][0] ^= gf_mul[col[2]][5];
state[2][0] ^= gf_mul[col[3]][3];
state[3][0] = gf_mul[col[0]][3];
state[3][0] ^= gf_mul[col[1]][4];
state[3][0] ^= gf_mul[col[2]][2];
state[3][0] ^= gf_mul[col[3]][5];
col[0] = state[0][1];
col[1] = state[1][1];
col[2] = state[2][1];
col[3] = state[3][1];
state[0][1] = gf_mul[col[0]][5];
state[0][1] ^= gf_mul[col[1]][3];
state[0][1] ^= gf_mul[col[2]][4];
state[0][1] ^= gf_mul[col[3]][2];
state[1][1] = gf_mul[col[0]][2];
state[1][1] ^= gf_mul[col[1]][5];
state[1][1] ^= gf_mul[col[2]][3];
state[1][1] ^= gf_mul[col[3]][4];
state[2][1] = gf_mul[col[0]][4];
state[2][1] ^= gf_mul[col[1]][2];
state[2][1] ^= gf_mul[col[2]][5];
state[2][1] ^= gf_mul[col[3]][3];
state[3][1] = gf_mul[col[0]][3];
state[3][1] ^= gf_mul[col[1]][4];
state[3][1] ^= gf_mul[col[2]][2];
state[3][1] ^= gf_mul[col[3]][5];
col[0] = state[0][2];
col[1] = state[1][2];
col[2] = state[2][2];
col[3] = state[3][2];
state[0][2] = gf_mul[col[0]][5];
state[0][2] ^= gf_mul[col[1]][3];
state[0][2] ^= gf_mul[col[2]][4];
state[0][2] ^= gf_mul[col[3]][2];
state[1][2] = gf_mul[col[0]][2];
state[1][2] ^= gf_mul[col[1]][5];
state[1][2] ^= gf_mul[col[2]][3];
state[1][2] ^= gf_mul[col[3]][4];
state[2][2] = gf_mul[col[0]][4];
state[2][2] ^= gf_mul[col[1]][2];
state[2][2] ^= gf_mul[col[2]][5];
state[2][2] ^= gf_mul[col[3]][3];
state[3][2] = gf_mul[col[0]][3];
state[3][2] ^= gf_mul[col[1]][4];
state[3][2] ^= gf_mul[col[2]][2];
state[3][2] ^= gf_mul[col[3]][5];
col[0] = state[0][3];
col[1] = state[1][3];
col[2] = state[2][3];
col[3] = state[3][3];
state[0][3] = gf_mul[col[0]][5];
state[0][3] ^= gf_mul[col[1]][3];
state[0][3] ^= gf_mul[col[2]][4];
state[0][3] ^= gf_mul[col[3]][2];
state[1][3] = gf_mul[col[0]][2];
state[1][3] ^= gf_mul[col[1]][5];
state[1][3] ^= gf_mul[col[2]][3];
state[1][3] ^= gf_mul[col[3]][4];
state[2][3] = gf_mul[col[0]][4];
state[2][3] ^= gf_mul[col[1]][2];
state[2][3] ^= gf_mul[col[2]][5];
state[2][3] ^= gf_mul[col[3]][3];
state[3][3] = gf_mul[col[0]][3];
state[3][3] ^= gf_mul[col[1]][4];
state[3][3] ^= gf_mul[col[2]][2];
state[3][3] ^= gf_mul[col[3]][5];
}
uint32_t SubWord(uint32_t word)
{
unsigned int result;
result = (int)aes_sbox[(word >> 4) & 0x0000000F][word & 0x0000000F];
result += (int)aes_sbox[(word >> 12) & 0x0000000F][(word >> 8) & 0x0000000F] << 8;
result += (int)aes_sbox[(word >> 20) & 0x0000000F][(word >> 16) & 0x0000000F] << 16;
result += (int)aes_sbox[(word >> 28) & 0x0000000F][(word >> 24) & 0x0000000F] << 24;
return(result);
}
#define KE_ROTWORD(x) ( ((x) << 8) | ((x) >> 24) )
void KeyExpansion(uint8_t key[], uint32_t w[], int keysize)
{
int Nb = 4, Nr, Nk, idx;
uint32_t temp, Rcon[] = { 0x01000000,0x02000000,0x04000000,0x08000000,0x10000000,0x20000000,
0x40000000,0x80000000,0x1b000000,0x36000000,0x6c000000,0xd8000000,
0xab000000,0x4d000000,0x9a000000 };
switch (keysize) {
case 128: Nr = 10; Nk = 4; break;
case 192: Nr = 12; Nk = 6; break;
case 256: Nr = 14; Nk = 8; break;
default: return;
}
for (idx = 0; idx < Nk; ++idx) {
w[idx] = ((key[4 * idx]) << 24) | ((key[4 * idx + 1]) << 16) |
((key[4 * idx + 2]) << 8) | ((key[4 * idx + 3]));
}
for (idx = Nk; idx < Nb * (Nr + 1); ++idx) {
temp = w[idx - 1];
if ((idx % Nk) == 0)
temp = SubWord(KE_ROTWORD(temp)) ^ Rcon[(idx - 1) / Nk];
else if (Nk > 6 && (idx % Nk) == 4)
temp = SubWord(temp);
w[idx] = w[idx - Nk] ^ temp;
}
}
void Decrypt(uint8_t in[], uint8_t out[], uint32_t key[], int keysize)
{
uint8_t state[4][4];
state[0][0] = in[0];
state[1][0] = in[1];
state[2][0] = in[2];
state[3][0] = in[3];
state[0][1] = in[4];
state[1][1] = in[5];
state[2][1] = in[6];
state[3][1] = in[7];
state[0][2] = in[8];
state[1][2] = in[9];
state[2][2] = in[10];
state[3][2] = in[11];
state[0][3] = in[12];
state[1][3] = in[13];
state[2][3] = in[14];
state[3][3] = in[15];
if (keysize > 128) {
if (keysize > 192) {
AddRoundKey(state, &key[56]);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[52]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[48]); InvMixColumns(state);
}
else {
AddRoundKey(state, &key[48]);
}
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[44]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[40]); InvMixColumns(state);
}
else {
AddRoundKey(state, &key[40]);
}
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[36]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[32]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[28]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[24]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[20]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[16]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[12]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[8]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[4]); InvMixColumns(state);
InvShiftRows(state); InvSubBytes(state); AddRoundKey(state, &key[0]);
out[0] = state[0][0];
out[1] = state[1][0];
out[2] = state[2][0];
out[3] = state[3][0];
out[4] = state[0][1];
out[5] = state[1][1];
out[6] = state[2][1];
out[7] = state[3][1];
out[8] = state[0][2];
out[9] = state[1][2];
out[10] = state[2][2];
out[11] = state[3][2];
out[12] = state[0][3];
out[13] = state[1][3];
out[14] = state[2][3];
out[15] = state[3][3];
}
Example
/*****Please include following header files*****/
// stdio.h
/***********************************************/
uint8_t ciphertext[16] = { 0x8e,0xa2,0xb7,0xca,0x51,0x67,0x45,0xbf,
0xea,0xfc,0x49,0x90,0x4b,0x49,0x60,0x89 };
uint8_t key[32] = { 0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,
0x09,0x0a,0x0b,0x0c,0x0d,0x0e,0x0f,0x10,0x11,
0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1a,
0x1b,0x1c,0x1d,0x1e,0x1f };
uint8_t plaintext[16];
uint32_t key_schedule[60];
KeyExpansion(key, key_schedule, 256);
Decrypt(ciphertext, plaintext, key_schedule, 256);
for (int idx = 0; idx < 16; idx++)
printf("%02x", plaintext[idx]);
Output
00112233445566778899aabbccddeeff