git.zerfleddert.de Git - hmcfgusb/blob - aes.c

   1 /*********************************************************************
   2 * Filename:   aes.c
   3 * Author:     Brad Conte (brad AT bradconte.com)
   4 * Copyright:
   5 * Disclaimer: This code is presented "as is" without any guarantees.
   6 * Details:    This code is the implementation of the AES algorithm and
   7               the CTR, CBC, and CCM modes of operation it can be used in.
   8                AES is, specified by the NIST in in publication FIPS PUB 197,
   9               availible at:
  10                * http://csrc.nist.gov/publications/fips/fips197/fips-197.pdf .
  11               The CBC and CTR modes of operation are specified by
  12               NIST SP 800-38 A, available at:
  13                * http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf .
  14               The CCM mode of operation is specified by NIST SP80-38 C, available at:
  15                * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
  16 *********************************************************************/
  17
  18 /*************************** HEADER FILES ***************************/
  19 #include <stdlib.h>
  20 #include <memory.h>
  21 #include "aes.h"
  22
  23 #include <stdio.h>
  24
  25 /****************************** MACROS ******************************/
  26 // The least significant byte of the word is rotated to the end.
  27 #define KE_ROTWORD(x) (((x) << 8) | ((x) >> 24))
  28
  29 #define TRUE  1
  30 #define FALSE 0
  31
  32 /**************************** DATA TYPES ****************************/
  33 #define AES_128_ROUNDS 10
  34 #define AES_192_ROUNDS 12
  35 #define AES_256_ROUNDS 14
  36
  37 /*********************** FUNCTION DECLARATIONS **********************/
  38 void ccm_prepare_first_ctr_blk(BYTE counter[], const BYTE nonce[], int nonce_len, int payload_len_store_size);
  39 void ccm_prepare_first_format_blk(BYTE buf[], int assoc_len, int payload_len, int payload_len_store_size, int mac_len, const BYTE nonce[], int nonce_len);
  40 void ccm_format_assoc_data(BYTE buf[], int *end_of_buf, const BYTE assoc[], int assoc_len);
  41 void ccm_format_payload_data(BYTE buf[], int *end_of_buf, const BYTE payload[], int payload_len);
  42
  43 /**************************** VARIABLES *****************************/
  44 // This is the specified AES SBox. To look up a substitution value, put the first
  45 // nibble in the first index (row) and the second nibble in the second index (column).
  46 static const BYTE aes_sbox[16][16] = {
  47         {0x63,0x7C,0x77,0x7B,0xF2,0x6B,0x6F,0xC5,0x30,0x01,0x67,0x2B,0xFE,0xD7,0xAB,0x76},
  48         {0xCA,0x82,0xC9,0x7D,0xFA,0x59,0x47,0xF0,0xAD,0xD4,0xA2,0xAF,0x9C,0xA4,0x72,0xC0},
  49         {0xB7,0xFD,0x93,0x26,0x36,0x3F,0xF7,0xCC,0x34,0xA5,0xE5,0xF1,0x71,0xD8,0x31,0x15},
  50         {0x04,0xC7,0x23,0xC3,0x18,0x96,0x05,0x9A,0x07,0x12,0x80,0xE2,0xEB,0x27,0xB2,0x75},
  51         {0x09,0x83,0x2C,0x1A,0x1B,0x6E,0x5A,0xA0,0x52,0x3B,0xD6,0xB3,0x29,0xE3,0x2F,0x84},
  52         {0x53,0xD1,0x00,0xED,0x20,0xFC,0xB1,0x5B,0x6A,0xCB,0xBE,0x39,0x4A,0x4C,0x58,0xCF},
  53         {0xD0,0xEF,0xAA,0xFB,0x43,0x4D,0x33,0x85,0x45,0xF9,0x02,0x7F,0x50,0x3C,0x9F,0xA8},
  54         {0x51,0xA3,0x40,0x8F,0x92,0x9D,0x38,0xF5,0xBC,0xB6,0xDA,0x21,0x10,0xFF,0xF3,0xD2},
  55         {0xCD,0x0C,0x13,0xEC,0x5F,0x97,0x44,0x17,0xC4,0xA7,0x7E,0x3D,0x64,0x5D,0x19,0x73},
  56         {0x60,0x81,0x4F,0xDC,0x22,0x2A,0x90,0x88,0x46,0xEE,0xB8,0x14,0xDE,0x5E,0x0B,0xDB},
  57         {0xE0,0x32,0x3A,0x0A,0x49,0x06,0x24,0x5C,0xC2,0xD3,0xAC,0x62,0x91,0x95,0xE4,0x79},
  58         {0xE7,0xC8,0x37,0x6D,0x8D,0xD5,0x4E,0xA9,0x6C,0x56,0xF4,0xEA,0x65,0x7A,0xAE,0x08},
  59         {0xBA,0x78,0x25,0x2E,0x1C,0xA6,0xB4,0xC6,0xE8,0xDD,0x74,0x1F,0x4B,0xBD,0x8B,0x8A},
  60         {0x70,0x3E,0xB5,0x66,0x48,0x03,0xF6,0x0E,0x61,0x35,0x57,0xB9,0x86,0xC1,0x1D,0x9E},
  61         {0xE1,0xF8,0x98,0x11,0x69,0xD9,0x8E,0x94,0x9B,0x1E,0x87,0xE9,0xCE,0x55,0x28,0xDF},
  62         {0x8C,0xA1,0x89,0x0D,0xBF,0xE6,0x42,0x68,0x41,0x99,0x2D,0x0F,0xB0,0x54,0xBB,0x16}
  63 };
  64
  65 static const BYTE aes_invsbox[16][16] = {
  66         {0x52,0x09,0x6A,0xD5,0x30,0x36,0xA5,0x38,0xBF,0x40,0xA3,0x9E,0x81,0xF3,0xD7,0xFB},
  67         {0x7C,0xE3,0x39,0x82,0x9B,0x2F,0xFF,0x87,0x34,0x8E,0x43,0x44,0xC4,0xDE,0xE9,0xCB},
  68         {0x54,0x7B,0x94,0x32,0xA6,0xC2,0x23,0x3D,0xEE,0x4C,0x95,0x0B,0x42,0xFA,0xC3,0x4E},
  69         {0x08,0x2E,0xA1,0x66,0x28,0xD9,0x24,0xB2,0x76,0x5B,0xA2,0x49,0x6D,0x8B,0xD1,0x25},
  70         {0x72,0xF8,0xF6,0x64,0x86,0x68,0x98,0x16,0xD4,0xA4,0x5C,0xCC,0x5D,0x65,0xB6,0x92},
  71         {0x6C,0x70,0x48,0x50,0xFD,0xED,0xB9,0xDA,0x5E,0x15,0x46,0x57,0xA7,0x8D,0x9D,0x84},
  72         {0x90,0xD8,0xAB,0x00,0x8C,0xBC,0xD3,0x0A,0xF7,0xE4,0x58,0x05,0xB8,0xB3,0x45,0x06},
  73         {0xD0,0x2C,0x1E,0x8F,0xCA,0x3F,0x0F,0x02,0xC1,0xAF,0xBD,0x03,0x01,0x13,0x8A,0x6B},
  74         {0x3A,0x91,0x11,0x41,0x4F,0x67,0xDC,0xEA,0x97,0xF2,0xCF,0xCE,0xF0,0xB4,0xE6,0x73},
  75         {0x96,0xAC,0x74,0x22,0xE7,0xAD,0x35,0x85,0xE2,0xF9,0x37,0xE8,0x1C,0x75,0xDF,0x6E},
  76         {0x47,0xF1,0x1A,0x71,0x1D,0x29,0xC5,0x89,0x6F,0xB7,0x62,0x0E,0xAA,0x18,0xBE,0x1B},
  77         {0xFC,0x56,0x3E,0x4B,0xC6,0xD2,0x79,0x20,0x9A,0xDB,0xC0,0xFE,0x78,0xCD,0x5A,0xF4},
  78         {0x1F,0xDD,0xA8,0x33,0x88,0x07,0xC7,0x31,0xB1,0x12,0x10,0x59,0x27,0x80,0xEC,0x5F},
  79         {0x60,0x51,0x7F,0xA9,0x19,0xB5,0x4A,0x0D,0x2D,0xE5,0x7A,0x9F,0x93,0xC9,0x9C,0xEF},
  80         {0xA0,0xE0,0x3B,0x4D,0xAE,0x2A,0xF5,0xB0,0xC8,0xEB,0xBB,0x3C,0x83,0x53,0x99,0x61},
  81         {0x17,0x2B,0x04,0x7E,0xBA,0x77,0xD6,0x26,0xE1,0x69,0x14,0x63,0x55,0x21,0x0C,0x7D}
  82 };
  83
  84 // This table stores pre-calculated values for all possible GF(2^8) calculations.This
  85 // table is only used by the (Inv)MixColumns steps.
  86 // USAGE: The second index (column) is the coefficient of multiplication. Only 7 different
  87 // coefficients are used: 0x01, 0x02, 0x03, 0x09, 0x0b, 0x0d, 0x0e, but multiplication by
  88 // 1 is negligible leaving only 6 coefficients. Each column of the table is devoted to one
  89 // of these coefficients, in the ascending order of value, from values 0x00 to 0xFF.
  90 static const BYTE gf_mul[256][6] = {
  91         {0x00,0x00,0x00,0x00,0x00,0x00},{0x02,0x03,0x09,0x0b,0x0d,0x0e},
  92         {0x04,0x06,0x12,0x16,0x1a,0x1c},{0x06,0x05,0x1b,0x1d,0x17,0x12},
  93         {0x08,0x0c,0x24,0x2c,0x34,0x38},{0x0a,0x0f,0x2d,0x27,0x39,0x36},
  94         {0x0c,0x0a,0x36,0x3a,0x2e,0x24},{0x0e,0x09,0x3f,0x31,0x23,0x2a},
  95         {0x10,0x18,0x48,0x58,0x68,0x70},{0x12,0x1b,0x41,0x53,0x65,0x7e},
  96         {0x14,0x1e,0x5a,0x4e,0x72,0x6c},{0x16,0x1d,0x53,0x45,0x7f,0x62},
  97         {0x18,0x14,0x6c,0x74,0x5c,0x48},{0x1a,0x17,0x65,0x7f,0x51,0x46},
  98         {0x1c,0x12,0x7e,0x62,0x46,0x54},{0x1e,0x11,0x77,0x69,0x4b,0x5a},
  99         {0x20,0x30,0x90,0xb0,0xd0,0xe0},{0x22,0x33,0x99,0xbb,0xdd,0xee},
 100         {0x24,0x36,0x82,0xa6,0xca,0xfc},{0x26,0x35,0x8b,0xad,0xc7,0xf2},
 101         {0x28,0x3c,0xb4,0x9c,0xe4,0xd8},{0x2a,0x3f,0xbd,0x97,0xe9,0xd6},
 102         {0x2c,0x3a,0xa6,0x8a,0xfe,0xc4},{0x2e,0x39,0xaf,0x81,0xf3,0xca},
 103         {0x30,0x28,0xd8,0xe8,0xb8,0x90},{0x32,0x2b,0xd1,0xe3,0xb5,0x9e},
 104         {0x34,0x2e,0xca,0xfe,0xa2,0x8c},{0x36,0x2d,0xc3,0xf5,0xaf,0x82},
 105         {0x38,0x24,0xfc,0xc4,0x8c,0xa8},{0x3a,0x27,0xf5,0xcf,0x81,0xa6},
 106         {0x3c,0x22,0xee,0xd2,0x96,0xb4},{0x3e,0x21,0xe7,0xd9,0x9b,0xba},
 107         {0x40,0x60,0x3b,0x7b,0xbb,0xdb},{0x42,0x63,0x32,0x70,0xb6,0xd5},
 108         {0x44,0x66,0x29,0x6d,0xa1,0xc7},{0x46,0x65,0x20,0x66,0xac,0xc9},
 109         {0x48,0x6c,0x1f,0x57,0x8f,0xe3},{0x4a,0x6f,0x16,0x5c,0x82,0xed},
 110         {0x4c,0x6a,0x0d,0x41,0x95,0xff},{0x4e,0x69,0x04,0x4a,0x98,0xf1},
 111         {0x50,0x78,0x73,0x23,0xd3,0xab},{0x52,0x7b,0x7a,0x28,0xde,0xa5},
 112         {0x54,0x7e,0x61,0x35,0xc9,0xb7},{0x56,0x7d,0x68,0x3e,0xc4,0xb9},
 113         {0x58,0x74,0x57,0x0f,0xe7,0x93},{0x5a,0x77,0x5e,0x04,0xea,0x9d},
 114         {0x5c,0x72,0x45,0x19,0xfd,0x8f},{0x5e,0x71,0x4c,0x12,0xf0,0x81},
 115         {0x60,0x50,0xab,0xcb,0x6b,0x3b},{0x62,0x53,0xa2,0xc0,0x66,0x35},
 116         {0x64,0x56,0xb9,0xdd,0x71,0x27},{0x66,0x55,0xb0,0xd6,0x7c,0x29},
 117         {0x68,0x5c,0x8f,0xe7,0x5f,0x03},{0x6a,0x5f,0x86,0xec,0x52,0x0d},
 118         {0x6c,0x5a,0x9d,0xf1,0x45,0x1f},{0x6e,0x59,0x94,0xfa,0x48,0x11},
 119         {0x70,0x48,0xe3,0x93,0x03,0x4b},{0x72,0x4b,0xea,0x98,0x0e,0x45},
 120         {0x74,0x4e,0xf1,0x85,0x19,0x57},{0x76,0x4d,0xf8,0x8e,0x14,0x59},
 121         {0x78,0x44,0xc7,0xbf,0x37,0x73},{0x7a,0x47,0xce,0xb4,0x3a,0x7d},
 122         {0x7c,0x42,0xd5,0xa9,0x2d,0x6f},{0x7e,0x41,0xdc,0xa2,0x20,0x61},
 123         {0x80,0xc0,0x76,0xf6,0x6d,0xad},{0x82,0xc3,0x7f,0xfd,0x60,0xa3},
 124         {0x84,0xc6,0x64,0xe0,0x77,0xb1},{0x86,0xc5,0x6d,0xeb,0x7a,0xbf},
 125         {0x88,0xcc,0x52,0xda,0x59,0x95},{0x8a,0xcf,0x5b,0xd1,0x54,0x9b},
 126         {0x8c,0xca,0x40,0xcc,0x43,0x89},{0x8e,0xc9,0x49,0xc7,0x4e,0x87},
 127         {0x90,0xd8,0x3e,0xae,0x05,0xdd},{0x92,0xdb,0x37,0xa5,0x08,0xd3},
 128         {0x94,0xde,0x2c,0xb8,0x1f,0xc1},{0x96,0xdd,0x25,0xb3,0x12,0xcf},
 129         {0x98,0xd4,0x1a,0x82,0x31,0xe5},{0x9a,0xd7,0x13,0x89,0x3c,0xeb},
 130         {0x9c,0xd2,0x08,0x94,0x2b,0xf9},{0x9e,0xd1,0x01,0x9f,0x26,0xf7},
 131         {0xa0,0xf0,0xe6,0x46,0xbd,0x4d},{0xa2,0xf3,0xef,0x4d,0xb0,0x43},
 132         {0xa4,0xf6,0xf4,0x50,0xa7,0x51},{0xa6,0xf5,0xfd,0x5b,0xaa,0x5f},
 133         {0xa8,0xfc,0xc2,0x6a,0x89,0x75},{0xaa,0xff,0xcb,0x61,0x84,0x7b},
 134         {0xac,0xfa,0xd0,0x7c,0x93,0x69},{0xae,0xf9,0xd9,0x77,0x9e,0x67},
 135         {0xb0,0xe8,0xae,0x1e,0xd5,0x3d},{0xb2,0xeb,0xa7,0x15,0xd8,0x33},
 136         {0xb4,0xee,0xbc,0x08,0xcf,0x21},{0xb6,0xed,0xb5,0x03,0xc2,0x2f},
 137         {0xb8,0xe4,0x8a,0x32,0xe1,0x05},{0xba,0xe7,0x83,0x39,0xec,0x0b},
 138         {0xbc,0xe2,0x98,0x24,0xfb,0x19},{0xbe,0xe1,0x91,0x2f,0xf6,0x17},
 139         {0xc0,0xa0,0x4d,0x8d,0xd6,0x76},{0xc2,0xa3,0x44,0x86,0xdb,0x78},
 140         {0xc4,0xa6,0x5f,0x9b,0xcc,0x6a},{0xc6,0xa5,0x56,0x90,0xc1,0x64},
 141         {0xc8,0xac,0x69,0xa1,0xe2,0x4e},{0xca,0xaf,0x60,0xaa,0xef,0x40},
 142         {0xcc,0xaa,0x7b,0xb7,0xf8,0x52},{0xce,0xa9,0x72,0xbc,0xf5,0x5c},
 143         {0xd0,0xb8,0x05,0xd5,0xbe,0x06},{0xd2,0xbb,0x0c,0xde,0xb3,0x08},
 144         {0xd4,0xbe,0x17,0xc3,0xa4,0x1a},{0xd6,0xbd,0x1e,0xc8,0xa9,0x14},
 145         {0xd8,0xb4,0x21,0xf9,0x8a,0x3e},{0xda,0xb7,0x28,0xf2,0x87,0x30},
 146         {0xdc,0xb2,0x33,0xef,0x90,0x22},{0xde,0xb1,0x3a,0xe4,0x9d,0x2c},
 147         {0xe0,0x90,0xdd,0x3d,0x06,0x96},{0xe2,0x93,0xd4,0x36,0x0b,0x98},
 148         {0xe4,0x96,0xcf,0x2b,0x1c,0x8a},{0xe6,0x95,0xc6,0x20,0x11,0x84},
 149         {0xe8,0x9c,0xf9,0x11,0x32,0xae},{0xea,0x9f,0xf0,0x1a,0x3f,0xa0},
 150         {0xec,0x9a,0xeb,0x07,0x28,0xb2},{0xee,0x99,0xe2,0x0c,0x25,0xbc},
 151         {0xf0,0x88,0x95,0x65,0x6e,0xe6},{0xf2,0x8b,0x9c,0x6e,0x63,0xe8},
 152         {0xf4,0x8e,0x87,0x73,0x74,0xfa},{0xf6,0x8d,0x8e,0x78,0x79,0xf4},
 153         {0xf8,0x84,0xb1,0x49,0x5a,0xde},{0xfa,0x87,0xb8,0x42,0x57,0xd0},
 154         {0xfc,0x82,0xa3,0x5f,0x40,0xc2},{0xfe,0x81,0xaa,0x54,0x4d,0xcc},
 155         {0x1b,0x9b,0xec,0xf7,0xda,0x41},{0x19,0x98,0xe5,0xfc,0xd7,0x4f},
 156         {0x1f,0x9d,0xfe,0xe1,0xc0,0x5d},{0x1d,0x9e,0xf7,0xea,0xcd,0x53},
 157         {0x13,0x97,0xc8,0xdb,0xee,0x79},{0x11,0x94,0xc1,0xd0,0xe3,0x77},
 158         {0x17,0x91,0xda,0xcd,0xf4,0x65},{0x15,0x92,0xd3,0xc6,0xf9,0x6b},
 159         {0x0b,0x83,0xa4,0xaf,0xb2,0x31},{0x09,0x80,0xad,0xa4,0xbf,0x3f},
 160         {0x0f,0x85,0xb6,0xb9,0xa8,0x2d},{0x0d,0x86,0xbf,0xb2,0xa5,0x23},
 161         {0x03,0x8f,0x80,0x83,0x86,0x09},{0x01,0x8c,0x89,0x88,0x8b,0x07},
 162         {0x07,0x89,0x92,0x95,0x9c,0x15},{0x05,0x8a,0x9b,0x9e,0x91,0x1b},
 163         {0x3b,0xab,0x7c,0x47,0x0a,0xa1},{0x39,0xa8,0x75,0x4c,0x07,0xaf},
 164         {0x3f,0xad,0x6e,0x51,0x10,0xbd},{0x3d,0xae,0x67,0x5a,0x1d,0xb3},
 165         {0x33,0xa7,0x58,0x6b,0x3e,0x99},{0x31,0xa4,0x51,0x60,0x33,0x97},
 166         {0x37,0xa1,0x4a,0x7d,0x24,0x85},{0x35,0xa2,0x43,0x76,0x29,0x8b},
 167         {0x2b,0xb3,0x34,0x1f,0x62,0xd1},{0x29,0xb0,0x3d,0x14,0x6f,0xdf},
 168         {0x2f,0xb5,0x26,0x09,0x78,0xcd},{0x2d,0xb6,0x2f,0x02,0x75,0xc3},
 169         {0x23,0xbf,0x10,0x33,0x56,0xe9},{0x21,0xbc,0x19,0x38,0x5b,0xe7},
 170         {0x27,0xb9,0x02,0x25,0x4c,0xf5},{0x25,0xba,0x0b,0x2e,0x41,0xfb},
 171         {0x5b,0xfb,0xd7,0x8c,0x61,0x9a},{0x59,0xf8,0xde,0x87,0x6c,0x94},
 172         {0x5f,0xfd,0xc5,0x9a,0x7b,0x86},{0x5d,0xfe,0xcc,0x91,0x76,0x88},
 173         {0x53,0xf7,0xf3,0xa0,0x55,0xa2},{0x51,0xf4,0xfa,0xab,0x58,0xac},
 174         {0x57,0xf1,0xe1,0xb6,0x4f,0xbe},{0x55,0xf2,0xe8,0xbd,0x42,0xb0},
 175         {0x4b,0xe3,0x9f,0xd4,0x09,0xea},{0x49,0xe0,0x96,0xdf,0x04,0xe4},
 176         {0x4f,0xe5,0x8d,0xc2,0x13,0xf6},{0x4d,0xe6,0x84,0xc9,0x1e,0xf8},
 177         {0x43,0xef,0xbb,0xf8,0x3d,0xd2},{0x41,0xec,0xb2,0xf3,0x30,0xdc},
 178         {0x47,0xe9,0xa9,0xee,0x27,0xce},{0x45,0xea,0xa0,0xe5,0x2a,0xc0},
 179         {0x7b,0xcb,0x47,0x3c,0xb1,0x7a},{0x79,0xc8,0x4e,0x37,0xbc,0x74},
 180         {0x7f,0xcd,0x55,0x2a,0xab,0x66},{0x7d,0xce,0x5c,0x21,0xa6,0x68},
 181         {0x73,0xc7,0x63,0x10,0x85,0x42},{0x71,0xc4,0x6a,0x1b,0x88,0x4c},
 182         {0x77,0xc1,0x71,0x06,0x9f,0x5e},{0x75,0xc2,0x78,0x0d,0x92,0x50},
 183         {0x6b,0xd3,0x0f,0x64,0xd9,0x0a},{0x69,0xd0,0x06,0x6f,0xd4,0x04},
 184         {0x6f,0xd5,0x1d,0x72,0xc3,0x16},{0x6d,0xd6,0x14,0x79,0xce,0x18},
 185         {0x63,0xdf,0x2b,0x48,0xed,0x32},{0x61,0xdc,0x22,0x43,0xe0,0x3c},
 186         {0x67,0xd9,0x39,0x5e,0xf7,0x2e},{0x65,0xda,0x30,0x55,0xfa,0x20},
 187         {0x9b,0x5b,0x9a,0x01,0xb7,0xec},{0x99,0x58,0x93,0x0a,0xba,0xe2},
 188         {0x9f,0x5d,0x88,0x17,0xad,0xf0},{0x9d,0x5e,0x81,0x1c,0xa0,0xfe},
 189         {0x93,0x57,0xbe,0x2d,0x83,0xd4},{0x91,0x54,0xb7,0x26,0x8e,0xda},
 190         {0x97,0x51,0xac,0x3b,0x99,0xc8},{0x95,0x52,0xa5,0x30,0x94,0xc6},
 191         {0x8b,0x43,0xd2,0x59,0xdf,0x9c},{0x89,0x40,0xdb,0x52,0xd2,0x92},
 192         {0x8f,0x45,0xc0,0x4f,0xc5,0x80},{0x8d,0x46,0xc9,0x44,0xc8,0x8e},
 193         {0x83,0x4f,0xf6,0x75,0xeb,0xa4},{0x81,0x4c,0xff,0x7e,0xe6,0xaa},
 194         {0x87,0x49,0xe4,0x63,0xf1,0xb8},{0x85,0x4a,0xed,0x68,0xfc,0xb6},
 195         {0xbb,0x6b,0x0a,0xb1,0x67,0x0c},{0xb9,0x68,0x03,0xba,0x6a,0x02},
 196         {0xbf,0x6d,0x18,0xa7,0x7d,0x10},{0xbd,0x6e,0x11,0xac,0x70,0x1e},
 197         {0xb3,0x67,0x2e,0x9d,0x53,0x34},{0xb1,0x64,0x27,0x96,0x5e,0x3a},
 198         {0xb7,0x61,0x3c,0x8b,0x49,0x28},{0xb5,0x62,0x35,0x80,0x44,0x26},
 199         {0xab,0x73,0x42,0xe9,0x0f,0x7c},{0xa9,0x70,0x4b,0xe2,0x02,0x72},
 200         {0xaf,0x75,0x50,0xff,0x15,0x60},{0xad,0x76,0x59,0xf4,0x18,0x6e},
 201         {0xa3,0x7f,0x66,0xc5,0x3b,0x44},{0xa1,0x7c,0x6f,0xce,0x36,0x4a},
 202         {0xa7,0x79,0x74,0xd3,0x21,0x58},{0xa5,0x7a,0x7d,0xd8,0x2c,0x56},
 203         {0xdb,0x3b,0xa1,0x7a,0x0c,0x37},{0xd9,0x38,0xa8,0x71,0x01,0x39},
 204         {0xdf,0x3d,0xb3,0x6c,0x16,0x2b},{0xdd,0x3e,0xba,0x67,0x1b,0x25},
 205         {0xd3,0x37,0x85,0x56,0x38,0x0f},{0xd1,0x34,0x8c,0x5d,0x35,0x01},
 206         {0xd7,0x31,0x97,0x40,0x22,0x13},{0xd5,0x32,0x9e,0x4b,0x2f,0x1d},
 207         {0xcb,0x23,0xe9,0x22,0x64,0x47},{0xc9,0x20,0xe0,0x29,0x69,0x49},
 208         {0xcf,0x25,0xfb,0x34,0x7e,0x5b},{0xcd,0x26,0xf2,0x3f,0x73,0x55},
 209         {0xc3,0x2f,0xcd,0x0e,0x50,0x7f},{0xc1,0x2c,0xc4,0x05,0x5d,0x71},
 210         {0xc7,0x29,0xdf,0x18,0x4a,0x63},{0xc5,0x2a,0xd6,0x13,0x47,0x6d},
 211         {0xfb,0x0b,0x31,0xca,0xdc,0xd7},{0xf9,0x08,0x38,0xc1,0xd1,0xd9},
 212         {0xff,0x0d,0x23,0xdc,0xc6,0xcb},{0xfd,0x0e,0x2a,0xd7,0xcb,0xc5},
 213         {0xf3,0x07,0x15,0xe6,0xe8,0xef},{0xf1,0x04,0x1c,0xed,0xe5,0xe1},
 214         {0xf7,0x01,0x07,0xf0,0xf2,0xf3},{0xf5,0x02,0x0e,0xfb,0xff,0xfd},
 215         {0xeb,0x13,0x79,0x92,0xb4,0xa7},{0xe9,0x10,0x70,0x99,0xb9,0xa9},
 216         {0xef,0x15,0x6b,0x84,0xae,0xbb},{0xed,0x16,0x62,0x8f,0xa3,0xb5},
 217         {0xe3,0x1f,0x5d,0xbe,0x80,0x9f},{0xe1,0x1c,0x54,0xb5,0x8d,0x91},
 218         {0xe7,0x19,0x4f,0xa8,0x9a,0x83},{0xe5,0x1a,0x46,0xa3,0x97,0x8d}
 219 };
 220
 221 /*********************** FUNCTION DEFINITIONS ***********************/
 222 // XORs the in and out buffers, storing the result in out. Length is in bytes.
 223 void xor_buf(const BYTE in[], BYTE out[], size_t len)
 224 {
 225         size_t idx;
 226
 227         for (idx = 0; idx < len; idx++)
 228                 out[idx] ^= in[idx];
 229 }
 230
 231 /*******************
 232 * AES - CBC
 233 *******************/
 234 int aes_encrypt_cbc(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
 235 {
 236         BYTE buf_in[AES_BLOCK_SIZE], buf_out[AES_BLOCK_SIZE], iv_buf[AES_BLOCK_SIZE];
 237         int blocks, idx;
 238
 239         if (in_len % AES_BLOCK_SIZE != 0)
 240                 return(FALSE);
 241
 242         blocks = in_len / AES_BLOCK_SIZE;
 243
 244         memcpy(iv_buf, iv, AES_BLOCK_SIZE);
 245
 246         for (idx = 0; idx < blocks; idx++) {
 247                 memcpy(buf_in, &in[idx * AES_BLOCK_SIZE], AES_BLOCK_SIZE);
 248                 xor_buf(iv_buf, buf_in, AES_BLOCK_SIZE);
 249                 aes_encrypt(buf_in, buf_out, key, keysize);
 250                 memcpy(&out[idx * AES_BLOCK_SIZE], buf_out, AES_BLOCK_SIZE);
 251                 memcpy(iv_buf, buf_out, AES_BLOCK_SIZE);
 252         }
 253
 254         return(TRUE);
 255 }
 256
 257 int aes_encrypt_cbc_mac(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
 258 {
 259         BYTE buf_in[AES_BLOCK_SIZE], buf_out[AES_BLOCK_SIZE], iv_buf[AES_BLOCK_SIZE];
 260         int blocks, idx;
 261
 262         if (in_len % AES_BLOCK_SIZE != 0)
 263                 return(FALSE);
 264
 265         blocks = in_len / AES_BLOCK_SIZE;
 266
 267         memcpy(iv_buf, iv, AES_BLOCK_SIZE);
 268
 269         for (idx = 0; idx < blocks; idx++) {
 270                 memcpy(buf_in, &in[idx * AES_BLOCK_SIZE], AES_BLOCK_SIZE);
 271                 xor_buf(iv_buf, buf_in, AES_BLOCK_SIZE);
 272                 aes_encrypt(buf_in, buf_out, key, keysize);
 273                 memcpy(iv_buf, buf_out, AES_BLOCK_SIZE);
 274                 // Do not output all encrypted blocks.
 275         }
 276
 277         memcpy(out, buf_out, AES_BLOCK_SIZE);   // Only output the last block.
 278
 279         return(TRUE);
 280 }
 281
 282 int aes_decrypt_cbc(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
 283 {
 284         BYTE buf_in[AES_BLOCK_SIZE], buf_out[AES_BLOCK_SIZE], iv_buf[AES_BLOCK_SIZE];
 285         int blocks, idx;
 286
 287         if (in_len % AES_BLOCK_SIZE != 0)
 288                 return(FALSE);
 289
 290         blocks = in_len / AES_BLOCK_SIZE;
 291
 292         memcpy(iv_buf, iv, AES_BLOCK_SIZE);
 293
 294         for (idx = 0; idx < blocks; idx++) {
 295                 memcpy(buf_in, &in[idx * AES_BLOCK_SIZE], AES_BLOCK_SIZE);
 296                 aes_decrypt(buf_in, buf_out, key, keysize);
 297                 xor_buf(iv_buf, buf_out, AES_BLOCK_SIZE);
 298                 memcpy(&out[idx * AES_BLOCK_SIZE], buf_out, AES_BLOCK_SIZE);
 299                 memcpy(iv_buf, buf_in, AES_BLOCK_SIZE);
 300         }
 301
 302         return(TRUE);
 303 }
 304
 305 /*******************
 306 * AES - CTR
 307 *******************/
 308 void increment_iv(BYTE iv[], int counter_size)
 309 {
 310         int idx;
 311
 312         // Use counter_size bytes at the end of the IV as the big-endian integer to increment.
 313         for (idx = AES_BLOCK_SIZE - 1; idx >= AES_BLOCK_SIZE - counter_size; idx--) {
 314                 iv[idx]++;
 315                 if (iv[idx] != 0 || idx == AES_BLOCK_SIZE - counter_size)
 316                         break;
 317         }
 318 }
 319
 320 // Performs the encryption in-place, the input and output buffers may be the same.
 321 // Input may be an arbitrary length (in bytes).
 322 void aes_encrypt_ctr(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
 323 {
 324         size_t idx = 0, last_block_length;
 325         BYTE iv_buf[AES_BLOCK_SIZE], out_buf[AES_BLOCK_SIZE];
 326
 327         if (in != out)
 328                 memcpy(out, in, in_len);
 329
 330         memcpy(iv_buf, iv, AES_BLOCK_SIZE);
 331         last_block_length = in_len - AES_BLOCK_SIZE;
 332
 333         if (in_len > AES_BLOCK_SIZE) {
 334                 for (idx = 0; idx < last_block_length; idx += AES_BLOCK_SIZE) {
 335                         aes_encrypt(iv_buf, out_buf, key, keysize);
 336                         xor_buf(out_buf, &out[idx], AES_BLOCK_SIZE);
 337                         increment_iv(iv_buf, AES_BLOCK_SIZE);
 338                 }
 339         }
 340
 341         aes_encrypt(iv_buf, out_buf, key, keysize);
 342         xor_buf(out_buf, &out[idx], in_len - idx);   // Use the Most Significant bytes.
 343 }
 344
 345 void aes_decrypt_ctr(const BYTE in[], size_t in_len, BYTE out[], const WORD key[], int keysize, const BYTE iv[])
 346 {
 347         // CTR encryption is its own inverse function.
 348         aes_encrypt_ctr(in, in_len, out, key, keysize, iv);
 349 }
 350
 351 /*******************
 352 * AES - CCM
 353 *******************/
 354 // out_len = payload_len + assoc_len
 355 int aes_encrypt_ccm(const BYTE payload[], WORD payload_len, const BYTE assoc[], unsigned short assoc_len,
 356                     const BYTE nonce[], unsigned short nonce_len, BYTE out[], WORD *out_len,
 357                     WORD mac_len, const BYTE key_str[], int keysize)
 358 {
 359         BYTE temp_iv[AES_BLOCK_SIZE], counter[AES_BLOCK_SIZE], mac[16], *buf;
 360         int end_of_buf, payload_len_store_size;
 361         WORD key[60];
 362
 363         if (mac_len != 4 && mac_len != 6 && mac_len != 8 && mac_len != 10 &&
 364            mac_len != 12 && mac_len != 14 && mac_len != 16)
 365                 return(FALSE);
 366
 367         if (nonce_len < 7 || nonce_len > 13)
 368                 return(FALSE);
 369
 370         if (assoc_len > 32768 /* = 2^15 */)
 371                 return(FALSE);
 372
 373         buf = (BYTE*)malloc(payload_len + assoc_len + 48 /*Round both payload and associated data up a block size and add an extra block.*/);
 374         if (! buf)
 375                 return(FALSE);
 376
 377         // Prepare the key for usage.
 378         aes_key_setup(key_str, key, keysize);
 379
 380         // Format the first block of the formatted data.
 381         payload_len_store_size = AES_BLOCK_SIZE - 1 - nonce_len;
 382         ccm_prepare_first_format_blk(buf, assoc_len, payload_len, payload_len_store_size, mac_len, nonce, nonce_len);
 383         end_of_buf = AES_BLOCK_SIZE;
 384
 385         // Format the Associated Data, aka, assoc[].
 386         ccm_format_assoc_data(buf, &end_of_buf, assoc, assoc_len);
 387
 388         // Format the Payload, aka payload[].
 389         ccm_format_payload_data(buf, &end_of_buf, payload, payload_len);
 390
 391         // Create the first counter block.
 392         ccm_prepare_first_ctr_blk(counter, nonce, nonce_len, payload_len_store_size);
 393
 394         // Perform the CBC operation with an IV of zeros on the formatted buffer to calculate the MAC.
 395         memset(temp_iv, 0, AES_BLOCK_SIZE);
 396         aes_encrypt_cbc_mac(buf, end_of_buf, mac, key, keysize, temp_iv);
 397
 398         // Copy the Payload and MAC to the output buffer.
 399         memcpy(out, payload, payload_len);
 400         memcpy(&out[payload_len], mac, mac_len);
 401
 402         // Encrypt the Payload with CTR mode with a counter starting at 1.
 403         memcpy(temp_iv, counter, AES_BLOCK_SIZE);
 404         increment_iv(temp_iv, AES_BLOCK_SIZE - 1 - mac_len);   // Last argument is the byte size of the counting portion of the counter block. /*BUG?*/
 405         aes_encrypt_ctr(out, payload_len, out, key, keysize, temp_iv);
 406
 407         // Encrypt the MAC with CTR mode with a counter starting at 0.
 408         aes_encrypt_ctr(&out[payload_len], mac_len, &out[payload_len], key, keysize, counter);
 409
 410         free(buf);
 411         *out_len = payload_len + mac_len;
 412
 413         return(TRUE);
 414 }
 415
 416 // plaintext_len = ciphertext_len - mac_len
 417 // Needs a flag for whether the MAC matches.
 418 int aes_decrypt_ccm(const BYTE ciphertext[], WORD ciphertext_len, const BYTE assoc[], unsigned short assoc_len,
 419                     const BYTE nonce[], unsigned short nonce_len, BYTE plaintext[], WORD *plaintext_len,
 420                     WORD mac_len, int *mac_auth, const BYTE key_str[], int keysize)
 421 {
 422         BYTE temp_iv[AES_BLOCK_SIZE], counter[AES_BLOCK_SIZE], mac[16], mac_buf[16], *buf;
 423         int end_of_buf, plaintext_len_store_size;
 424         WORD key[60];
 425
 426         if (ciphertext_len <= mac_len)
 427                 return(FALSE);
 428
 429         buf = (BYTE*)malloc(assoc_len + ciphertext_len /*ciphertext_len = plaintext_len + mac_len*/ + 48);
 430         if (! buf)
 431                 return(FALSE);
 432
 433         // Prepare the key for usage.
 434         aes_key_setup(key_str, key, keysize);
 435
 436         // Copy the plaintext and MAC to the output buffers.
 437         *plaintext_len = ciphertext_len - mac_len;
 438         plaintext_len_store_size = AES_BLOCK_SIZE - 1 - nonce_len;
 439         memcpy(plaintext, ciphertext, *plaintext_len);
 440         memcpy(mac, &ciphertext[*plaintext_len], mac_len);
 441
 442         // Prepare the first counter block for use in decryption.
 443         ccm_prepare_first_ctr_blk(counter, nonce, nonce_len, plaintext_len_store_size);
 444
 445         // Decrypt the Payload with CTR mode with a counter starting at 1.
 446         memcpy(temp_iv, counter, AES_BLOCK_SIZE);
 447         increment_iv(temp_iv, AES_BLOCK_SIZE - 1 - mac_len);   // (AES_BLOCK_SIZE - 1 - mac_len) is the byte size of the counting portion of the counter block.
 448         aes_decrypt_ctr(plaintext, *plaintext_len, plaintext, key, keysize, temp_iv);
 449
 450         // Setting mac_auth to NULL disables the authentication check.
 451         if (mac_auth != NULL) {
 452                 // Decrypt the MAC with CTR mode with a counter starting at 0.
 453                 aes_decrypt_ctr(mac, mac_len, mac, key, keysize, counter);
 454
 455                 // Format the first block of the formatted data.
 456                 plaintext_len_store_size = AES_BLOCK_SIZE - 1 - nonce_len;
 457                 ccm_prepare_first_format_blk(buf, assoc_len, *plaintext_len, plaintext_len_store_size, mac_len, nonce, nonce_len);
 458                 end_of_buf = AES_BLOCK_SIZE;
 459
 460                 // Format the Associated Data into the authentication buffer.
 461                 ccm_format_assoc_data(buf, &end_of_buf, assoc, assoc_len);
 462
 463                 // Format the Payload into the authentication buffer.
 464                 ccm_format_payload_data(buf, &end_of_buf, plaintext, *plaintext_len);
 465
 466                 // Perform the CBC operation with an IV of zeros on the formatted buffer to calculate the MAC.
 467                 memset(temp_iv, 0, AES_BLOCK_SIZE);
 468                 aes_encrypt_cbc_mac(buf, end_of_buf, mac_buf, key, keysize, temp_iv);
 469
 470                 // Compare the calculated MAC against the MAC embedded in the ciphertext to see if they are the same.
 471                 if (! memcmp(mac, mac_buf, mac_len)) {
 472                         *mac_auth = TRUE;
 473                 }
 474                 else {
 475                         *mac_auth = FALSE;
 476                         memset(plaintext, 0, *plaintext_len);
 477                 }
 478         }
 479
 480         free(buf);
 481
 482         return(TRUE);
 483 }
 484
 485 // Creates the first counter block. First byte is flags, then the nonce, then the incremented part.
 486 void ccm_prepare_first_ctr_blk(BYTE counter[], const BYTE nonce[], int nonce_len, int payload_len_store_size)
 487 {
 488         memset(counter, 0, AES_BLOCK_SIZE);
 489         counter[0] = (payload_len_store_size - 1) & 0x07;
 490         memcpy(&counter[1], nonce, nonce_len);
 491 }
 492
 493 void ccm_prepare_first_format_blk(BYTE buf[], int assoc_len, int payload_len, int payload_len_store_size, int mac_len, const BYTE nonce[], int nonce_len)
 494 {
 495         // Set the flags for the first byte of the first block.
 496         buf[0] = ((((mac_len - 2) / 2) & 0x07) << 3) | ((payload_len_store_size - 1) & 0x07);
 497         if (assoc_len > 0)
 498                 buf[0] += 0x40;
 499         // Format the rest of the first block, storing the nonce and the size of the payload.
 500         memcpy(&buf[1], nonce, nonce_len);
 501         memset(&buf[1 + nonce_len], 0, AES_BLOCK_SIZE - 1 - nonce_len);
 502         buf[15] = payload_len & 0x000000FF;
 503         buf[14] = (payload_len >> 8) & 0x000000FF;
 504 }
 505
 506 void ccm_format_assoc_data(BYTE buf[], int *end_of_buf, const BYTE assoc[], int assoc_len)
 507 {
 508         int pad;
 509
 510         buf[*end_of_buf + 1] = assoc_len & 0x00FF;
 511         buf[*end_of_buf] = (assoc_len >> 8) & 0x00FF;
 512         *end_of_buf += 2;
 513         memcpy(&buf[*end_of_buf], assoc, assoc_len);
 514         *end_of_buf += assoc_len;
 515         pad = AES_BLOCK_SIZE - (*end_of_buf % AES_BLOCK_SIZE); /*BUG?*/
 516         memset(&buf[*end_of_buf], 0, pad);
 517         *end_of_buf += pad;
 518 }
 519
 520 void ccm_format_payload_data(BYTE buf[], int *end_of_buf, const BYTE payload[], int payload_len)
 521 {
 522         int pad;
 523
 524         memcpy(&buf[*end_of_buf], payload, payload_len);
 525         *end_of_buf += payload_len;
 526         pad = *end_of_buf % AES_BLOCK_SIZE;
 527         if (pad != 0)
 528                 pad = AES_BLOCK_SIZE - pad;
 529         memset(&buf[*end_of_buf], 0, pad);
 530         *end_of_buf += pad;
 531 }
 532
 533 /*******************
 534 * AES
 535 *******************/
 536 /////////////////
 537 // KEY EXPANSION
 538 /////////////////
 539
 540 // Substitutes a word using the AES S-Box.
 541 WORD SubWord(WORD word)
 542 {
 543         unsigned int result;
 544
 545         result = (int)aes_sbox[(word >> 4) & 0x0000000F][word & 0x0000000F];
 546         result += (int)aes_sbox[(word >> 12) & 0x0000000F][(word >> 8) & 0x0000000F] << 8;
 547         result += (int)aes_sbox[(word >> 20) & 0x0000000F][(word >> 16) & 0x0000000F] << 16;
 548         result += (int)aes_sbox[(word >> 28) & 0x0000000F][(word >> 24) & 0x0000000F] << 24;
 549         return(result);
 550 }
 551
 552 // Performs the action of generating the keys that will be used in every round of
 553 // encryption. "key" is the user-supplied input key, "w" is the output key schedule,
 554 // "keysize" is the length in bits of "key", must be 128, 192, or 256.
 555 void aes_key_setup(const BYTE key[], WORD w[], int keysize)
 556 {
 557         int Nb=4,Nr,Nk,idx;
 558         WORD temp,Rcon[]={0x01000000,0x02000000,0x04000000,0x08000000,0x10000000,0x20000000,
 559                           0x40000000,0x80000000,0x1b000000,0x36000000,0x6c000000,0xd8000000,
 560                           0xab000000,0x4d000000,0x9a000000};
 561
 562         switch (keysize) {
 563                 case 128: Nr = 10; Nk = 4; break;
 564                 case 192: Nr = 12; Nk = 6; break;
 565                 case 256: Nr = 14; Nk = 8; break;
 566                 default: return;
 567         }
 568
 569         for (idx=0; idx < Nk; ++idx) {
 570                 w[idx] = ((key[4 * idx]) << 24) | ((key[4 * idx + 1]) << 16) |
 571                                    ((key[4 * idx + 2]) << 8) | ((key[4 * idx + 3]));
 572         }
 573
 574         for (idx = Nk; idx < Nb * (Nr+1); ++idx) {
 575                 temp = w[idx - 1];
 576                 if ((idx % Nk) == 0)
 577                         temp = SubWord(KE_ROTWORD(temp)) ^ Rcon[(idx-1)/Nk];
 578                 else if (Nk > 6 && (idx % Nk) == 4)
 579                         temp = SubWord(temp);
 580                 w[idx] = w[idx-Nk] ^ temp;
 581         }
 582 }
 583
 584 /////////////////
 585 // ADD ROUND KEY
 586 /////////////////
 587
 588 // Performs the AddRoundKey step. Each round has its own pre-generated 16-byte key in the
 589 // form of 4 integers (the "w" array). Each integer is XOR'd by one column of the state.
 590 // Also performs the job of InvAddRoundKey(); since the function is a simple XOR process,
 591 // it is its own inverse.
 592 void AddRoundKey(BYTE state[][4], const WORD w[])
 593 {
 594         BYTE subkey[4];
 595
 596         // memcpy(subkey,&w[idx],4); // Not accurate for big endian machines
 597         // Subkey 1
 598         subkey[0] = w[0] >> 24;
 599         subkey[1] = w[0] >> 16;
 600         subkey[2] = w[0] >> 8;
 601         subkey[3] = w[0];
 602         state[0][0] ^= subkey[0];
 603         state[1][0] ^= subkey[1];
 604         state[2][0] ^= subkey[2];
 605         state[3][0] ^= subkey[3];
 606         // Subkey 2
 607         subkey[0] = w[1] >> 24;
 608         subkey[1] = w[1] >> 16;
 609         subkey[2] = w[1] >> 8;
 610         subkey[3] = w[1];
 611         state[0][1] ^= subkey[0];
 612         state[1][1] ^= subkey[1];
 613         state[2][1] ^= subkey[2];
 614         state[3][1] ^= subkey[3];
 615         // Subkey 3
 616         subkey[0] = w[2] >> 24;
 617         subkey[1] = w[2] >> 16;
 618         subkey[2] = w[2] >> 8;
 619         subkey[3] = w[2];
 620         state[0][2] ^= subkey[0];
 621         state[1][2] ^= subkey[1];
 622         state[2][2] ^= subkey[2];
 623         state[3][2] ^= subkey[3];
 624         // Subkey 4
 625         subkey[0] = w[3] >> 24;
 626         subkey[1] = w[3] >> 16;
 627         subkey[2] = w[3] >> 8;
 628         subkey[3] = w[3];
 629         state[0][3] ^= subkey[0];
 630         state[1][3] ^= subkey[1];
 631         state[2][3] ^= subkey[2];
 632         state[3][3] ^= subkey[3];
 633 }
 634
 635 /////////////////
 636 // (Inv)SubBytes
 637 /////////////////
 638
 639 // Performs the SubBytes step. All bytes in the state are substituted with a
 640 // pre-calculated value from a lookup table.
 641 void SubBytes(BYTE state[][4])
 642 {
 643         state[0][0] = aes_sbox[state[0][0] >> 4][state[0][0] & 0x0F];
 644         state[0][1] = aes_sbox[state[0][1] >> 4][state[0][1] & 0x0F];
 645         state[0][2] = aes_sbox[state[0][2] >> 4][state[0][2] & 0x0F];
 646         state[0][3] = aes_sbox[state[0][3] >> 4][state[0][3] & 0x0F];
 647         state[1][0] = aes_sbox[state[1][0] >> 4][state[1][0] & 0x0F];
 648         state[1][1] = aes_sbox[state[1][1] >> 4][state[1][1] & 0x0F];
 649         state[1][2] = aes_sbox[state[1][2] >> 4][state[1][2] & 0x0F];
 650         state[1][3] = aes_sbox[state[1][3] >> 4][state[1][3] & 0x0F];
 651         state[2][0] = aes_sbox[state[2][0] >> 4][state[2][0] & 0x0F];
 652         state[2][1] = aes_sbox[state[2][1] >> 4][state[2][1] & 0x0F];
 653         state[2][2] = aes_sbox[state[2][2] >> 4][state[2][2] & 0x0F];
 654         state[2][3] = aes_sbox[state[2][3] >> 4][state[2][3] & 0x0F];
 655         state[3][0] = aes_sbox[state[3][0] >> 4][state[3][0] & 0x0F];
 656         state[3][1] = aes_sbox[state[3][1] >> 4][state[3][1] & 0x0F];
 657         state[3][2] = aes_sbox[state[3][2] >> 4][state[3][2] & 0x0F];
 658         state[3][3] = aes_sbox[state[3][3] >> 4][state[3][3] & 0x0F];
 659 }
 660
 661 void InvSubBytes(BYTE state[][4])
 662 {
 663         state[0][0] = aes_invsbox[state[0][0] >> 4][state[0][0] & 0x0F];
 664         state[0][1] = aes_invsbox[state[0][1] >> 4][state[0][1] & 0x0F];
 665         state[0][2] = aes_invsbox[state[0][2] >> 4][state[0][2] & 0x0F];
 666         state[0][3] = aes_invsbox[state[0][3] >> 4][state[0][3] & 0x0F];
 667         state[1][0] = aes_invsbox[state[1][0] >> 4][state[1][0] & 0x0F];
 668         state[1][1] = aes_invsbox[state[1][1] >> 4][state[1][1] & 0x0F];
 669         state[1][2] = aes_invsbox[state[1][2] >> 4][state[1][2] & 0x0F];
 670         state[1][3] = aes_invsbox[state[1][3] >> 4][state[1][3] & 0x0F];
 671         state[2][0] = aes_invsbox[state[2][0] >> 4][state[2][0] & 0x0F];
 672         state[2][1] = aes_invsbox[state[2][1] >> 4][state[2][1] & 0x0F];
 673         state[2][2] = aes_invsbox[state[2][2] >> 4][state[2][2] & 0x0F];
 674         state[2][3] = aes_invsbox[state[2][3] >> 4][state[2][3] & 0x0F];
 675         state[3][0] = aes_invsbox[state[3][0] >> 4][state[3][0] & 0x0F];
 676         state[3][1] = aes_invsbox[state[3][1] >> 4][state[3][1] & 0x0F];
 677         state[3][2] = aes_invsbox[state[3][2] >> 4][state[3][2] & 0x0F];
 678         state[3][3] = aes_invsbox[state[3][3] >> 4][state[3][3] & 0x0F];
 679 }
 680
 681 /////////////////
 682 // (Inv)ShiftRows
 683 /////////////////
 684
 685 // Performs the ShiftRows step. All rows are shifted cylindrically to the left.
 686 void ShiftRows(BYTE state[][4])
 687 {
 688         int t;
 689
 690         // Shift left by 1
 691         t = state[1][0];
 692         state[1][0] = state[1][1];
 693         state[1][1] = state[1][2];
 694         state[1][2] = state[1][3];
 695         state[1][3] = t;
 696         // Shift left by 2
 697         t = state[2][0];
 698         state[2][0] = state[2][2];
 699         state[2][2] = t;
 700         t = state[2][1];
 701         state[2][1] = state[2][3];
 702         state[2][3] = t;
 703         // Shift left by 3
 704         t = state[3][0];
 705         state[3][0] = state[3][3];
 706         state[3][3] = state[3][2];
 707         state[3][2] = state[3][1];
 708         state[3][1] = t;
 709 }
 710
 711 // All rows are shifted cylindrically to the right.
 712 void InvShiftRows(BYTE state[][4])
 713 {
 714         int t;
 715
 716         // Shift right by 1
 717         t = state[1][3];
 718         state[1][3] = state[1][2];
 719         state[1][2] = state[1][1];
 720         state[1][1] = state[1][0];
 721         state[1][0] = t;
 722         // Shift right by 2
 723         t = state[2][3];
 724         state[2][3] = state[2][1];
 725         state[2][1] = t;
 726         t = state[2][2];
 727         state[2][2] = state[2][0];
 728         state[2][0] = t;
 729         // Shift right by 3
 730         t = state[3][3];
 731         state[3][3] = state[3][0];
 732         state[3][0] = state[3][1];
 733         state[3][1] = state[3][2];
 734         state[3][2] = t;
 735 }
 736
 737 /////////////////
 738 // (Inv)MixColumns
 739 /////////////////
 740
 741 // Performs the MixColums step. The state is multiplied by itself using matrix
 742 // multiplication in a Galios Field 2^8. All multiplication is pre-computed in a table.
 743 // Addition is equivilent to XOR. (Must always make a copy of the column as the original
 744 // values will be destoyed.)
 745 void MixColumns(BYTE state[][4])
 746 {
 747         BYTE col[4];
 748
 749         // Column 1
 750         col[0] = state[0][0];
 751         col[1] = state[1][0];
 752         col[2] = state[2][0];
 753         col[3] = state[3][0];
 754         state[0][0] = gf_mul[col[0]][0];
 755         state[0][0] ^= gf_mul[col[1]][1];
 756         state[0][0] ^= col[2];
 757         state[0][0] ^= col[3];
 758         state[1][0] = col[0];
 759         state[1][0] ^= gf_mul[col[1]][0];
 760         state[1][0] ^= gf_mul[col[2]][1];
 761         state[1][0] ^= col[3];
 762         state[2][0] = col[0];
 763         state[2][0] ^= col[1];
 764         state[2][0] ^= gf_mul[col[2]][0];
 765         state[2][0] ^= gf_mul[col[3]][1];
 766         state[3][0] = gf_mul[col[0]][1];
 767         state[3][0] ^= col[1];
 768         state[3][0] ^= col[2];
 769         state[3][0] ^= gf_mul[col[3]][0];
 770         // Column 2
 771         col[0] = state[0][1];
 772         col[1] = state[1][1];
 773         col[2] = state[2][1];
 774         col[3] = state[3][1];
 775         state[0][1] = gf_mul[col[0]][0];
 776         state[0][1] ^= gf_mul[col[1]][1];
 777         state[0][1] ^= col[2];
 778         state[0][1] ^= col[3];
 779         state[1][1] = col[0];
 780         state[1][1] ^= gf_mul[col[1]][0];
 781         state[1][1] ^= gf_mul[col[2]][1];
 782         state[1][1] ^= col[3];
 783         state[2][1] = col[0];
 784         state[2][1] ^= col[1];
 785         state[2][1] ^= gf_mul[col[2]][0];
 786         state[2][1] ^= gf_mul[col[3]][1];
 787         state[3][1] = gf_mul[col[0]][1];
 788         state[3][1] ^= col[1];
 789         state[3][1] ^= col[2];
 790         state[3][1] ^= gf_mul[col[3]][0];
 791         // Column 3
 792         col[0] = state[0][2];
 793         col[1] = state[1][2];
 794         col[2] = state[2][2];
 795         col[3] = state[3][2];
 796         state[0][2] = gf_mul[col[0]][0];
 797         state[0][2] ^= gf_mul[col[1]][1];
 798         state[0][2] ^= col[2];
 799         state[0][2] ^= col[3];
 800         state[1][2] = col[0];
 801         state[1][2] ^= gf_mul[col[1]][0];
 802         state[1][2] ^= gf_mul[col[2]][1];
 803         state[1][2] ^= col[3];
 804         state[2][2] = col[0];
 805         state[2][2] ^= col[1];
 806         state[2][2] ^= gf_mul[col[2]][0];
 807         state[2][2] ^= gf_mul[col[3]][1];
 808         state[3][2] = gf_mul[col[0]][1];
 809         state[3][2] ^= col[1];
 810         state[3][2] ^= col[2];
 811         state[3][2] ^= gf_mul[col[3]][0];
 812         // Column 4
 813         col[0] = state[0][3];
 814         col[1] = state[1][3];
 815         col[2] = state[2][3];
 816         col[3] = state[3][3];
 817         state[0][3] = gf_mul[col[0]][0];
 818         state[0][3] ^= gf_mul[col[1]][1];
 819         state[0][3] ^= col[2];
 820         state[0][3] ^= col[3];
 821         state[1][3] = col[0];
 822         state[1][3] ^= gf_mul[col[1]][0];
 823         state[1][3] ^= gf_mul[col[2]][1];
 824         state[1][3] ^= col[3];
 825         state[2][3] = col[0];
 826         state[2][3] ^= col[1];
 827         state[2][3] ^= gf_mul[col[2]][0];
 828         state[2][3] ^= gf_mul[col[3]][1];
 829         state[3][3] = gf_mul[col[0]][1];
 830         state[3][3] ^= col[1];
 831         state[3][3] ^= col[2];
 832         state[3][3] ^= gf_mul[col[3]][0];
 833 }
 834
 835 void InvMixColumns(BYTE state[][4])
 836 {
 837         BYTE col[4];
 838
 839         // Column 1
 840         col[0] = state[0][0];
 841         col[1] = state[1][0];
 842         col[2] = state[2][0];
 843         col[3] = state[3][0];
 844         state[0][0] = gf_mul[col[0]][5];
 845         state[0][0] ^= gf_mul[col[1]][3];
 846         state[0][0] ^= gf_mul[col[2]][4];
 847         state[0][0] ^= gf_mul[col[3]][2];
 848         state[1][0] = gf_mul[col[0]][2];
 849         state[1][0] ^= gf_mul[col[1]][5];
 850         state[1][0] ^= gf_mul[col[2]][3];
 851         state[1][0] ^= gf_mul[col[3]][4];
 852         state[2][0] = gf_mul[col[0]][4];
 853         state[2][0] ^= gf_mul[col[1]][2];
 854         state[2][0] ^= gf_mul[col[2]][5];
 855         state[2][0] ^= gf_mul[col[3]][3];
 856         state[3][0] = gf_mul[col[0]][3];
 857         state[3][0] ^= gf_mul[col[1]][4];
 858         state[3][0] ^= gf_mul[col[2]][2];
 859         state[3][0] ^= gf_mul[col[3]][5];
 860         // Column 2
 861         col[0] = state[0][1];
 862         col[1] = state[1][1];
 863         col[2] = state[2][1];
 864         col[3] = state[3][1];
 865         state[0][1] = gf_mul[col[0]][5];
 866         state[0][1] ^= gf_mul[col[1]][3];
 867         state[0][1] ^= gf_mul[col[2]][4];
 868         state[0][1] ^= gf_mul[col[3]][2];
 869         state[1][1] = gf_mul[col[0]][2];
 870         state[1][1] ^= gf_mul[col[1]][5];
 871         state[1][1] ^= gf_mul[col[2]][3];
 872         state[1][1] ^= gf_mul[col[3]][4];
 873         state[2][1] = gf_mul[col[0]][4];
 874         state[2][1] ^= gf_mul[col[1]][2];
 875         state[2][1] ^= gf_mul[col[2]][5];
 876         state[2][1] ^= gf_mul[col[3]][3];
 877         state[3][1] = gf_mul[col[0]][3];
 878         state[3][1] ^= gf_mul[col[1]][4];
 879         state[3][1] ^= gf_mul[col[2]][2];
 880         state[3][1] ^= gf_mul[col[3]][5];
 881         // Column 3
 882         col[0] = state[0][2];
 883         col[1] = state[1][2];
 884         col[2] = state[2][2];
 885         col[3] = state[3][2];
 886         state[0][2] = gf_mul[col[0]][5];
 887         state[0][2] ^= gf_mul[col[1]][3];
 888         state[0][2] ^= gf_mul[col[2]][4];
 889         state[0][2] ^= gf_mul[col[3]][2];
 890         state[1][2] = gf_mul[col[0]][2];
 891         state[1][2] ^= gf_mul[col[1]][5];
 892         state[1][2] ^= gf_mul[col[2]][3];
 893         state[1][2] ^= gf_mul[col[3]][4];
 894         state[2][2] = gf_mul[col[0]][4];
 895         state[2][2] ^= gf_mul[col[1]][2];
 896         state[2][2] ^= gf_mul[col[2]][5];
 897         state[2][2] ^= gf_mul[col[3]][3];
 898         state[3][2] = gf_mul[col[0]][3];
 899         state[3][2] ^= gf_mul[col[1]][4];
 900         state[3][2] ^= gf_mul[col[2]][2];
 901         state[3][2] ^= gf_mul[col[3]][5];
 902         // Column 4
 903         col[0] = state[0][3];
 904         col[1] = state[1][3];
 905         col[2] = state[2][3];
 906         col[3] = state[3][3];
 907         state[0][3] = gf_mul[col[0]][5];
 908         state[0][3] ^= gf_mul[col[1]][3];
 909         state[0][3] ^= gf_mul[col[2]][4];
 910         state[0][3] ^= gf_mul[col[3]][2];
 911         state[1][3] = gf_mul[col[0]][2];
 912         state[1][3] ^= gf_mul[col[1]][5];
 913         state[1][3] ^= gf_mul[col[2]][3];
 914         state[1][3] ^= gf_mul[col[3]][4];
 915         state[2][3] = gf_mul[col[0]][4];
 916         state[2][3] ^= gf_mul[col[1]][2];
 917         state[2][3] ^= gf_mul[col[2]][5];
 918         state[2][3] ^= gf_mul[col[3]][3];
 919         state[3][3] = gf_mul[col[0]][3];
 920         state[3][3] ^= gf_mul[col[1]][4];
 921         state[3][3] ^= gf_mul[col[2]][2];
 922         state[3][3] ^= gf_mul[col[3]][5];
 923 }
 924
 925 /////////////////
 926 // (En/De)Crypt
 927 /////////////////
 928
 929 void aes_encrypt(const BYTE in[], BYTE out[], const WORD key[], int keysize)
 930 {
 931         BYTE state[4][4];
 932
 933         // Copy input array (should be 16 bytes long) to a matrix (sequential bytes are ordered
 934         // by row, not col) called "state" for processing.
 935         // *** Implementation note: The official AES documentation references the state by
 936         // column, then row. Accessing an element in C requires row then column. Thus, all state
 937         // references in AES must have the column and row indexes reversed for C implementation.
 938         state[0][0] = in[0];
 939         state[1][0] = in[1];
 940         state[2][0] = in[2];
 941         state[3][0] = in[3];
 942         state[0][1] = in[4];
 943         state[1][1] = in[5];
 944         state[2][1] = in[6];
 945         state[3][1] = in[7];
 946         state[0][2] = in[8];
 947         state[1][2] = in[9];
 948         state[2][2] = in[10];
 949         state[3][2] = in[11];
 950         state[0][3] = in[12];
 951         state[1][3] = in[13];
 952         state[2][3] = in[14];
 953         state[3][3] = in[15];
 954
 955         // Perform the necessary number of rounds. The round key is added first.
 956         // The last round does not perform the MixColumns step.
 957         AddRoundKey(state,&key[0]);
 958         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[4]);
 959         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[8]);
 960         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[12]);
 961         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[16]);
 962         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[20]);
 963         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[24]);
 964         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[28]);
 965         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[32]);
 966         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[36]);
 967         if (keysize != 128) {
 968                 SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[40]);
 969                 SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[44]);
 970                 if (keysize != 192) {
 971                         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[48]);
 972                         SubBytes(state); ShiftRows(state); MixColumns(state); AddRoundKey(state,&key[52]);
 973                         SubBytes(state); ShiftRows(state); AddRoundKey(state,&key[56]);
 974                 }
 975                 else {
 976                         SubBytes(state); ShiftRows(state); AddRoundKey(state,&key[48]);
 977                 }
 978         }
 979         else {
 980                 SubBytes(state); ShiftRows(state); AddRoundKey(state,&key[40]);
 981         }
 982
 983         // Copy the state to the output array.
 984         out[0] = state[0][0];
 985         out[1] = state[1][0];
 986         out[2] = state[2][0];
 987         out[3] = state[3][0];
 988         out[4] = state[0][1];
 989         out[5] = state[1][1];
 990         out[6] = state[2][1];
 991         out[7] = state[3][1];
 992         out[8] = state[0][2];
 993         out[9] = state[1][2];
 994         out[10] = state[2][2];
 995         out[11] = state[3][2];
 996         out[12] = state[0][3];
 997         out[13] = state[1][3];
 998         out[14] = state[2][3];
 999         out[15] = state[3][3];
1000 }
1001
1002 void aes_decrypt(const BYTE in[], BYTE out[], const WORD key[], int keysize)
1003 {
1004         BYTE state[4][4];
1005
1006         // Copy the input to the state.
1007         state[0][0] = in[0];
1008         state[1][0] = in[1];
1009         state[2][0] = in[2];
1010         state[3][0] = in[3];
1011         state[0][1] = in[4];
1012         state[1][1] = in[5];
1013         state[2][1] = in[6];
1014         state[3][1] = in[7];
1015         state[0][2] = in[8];
1016         state[1][2] = in[9];
1017         state[2][2] = in[10];
1018         state[3][2] = in[11];
1019         state[0][3] = in[12];
1020         state[1][3] = in[13];
1021         state[2][3] = in[14];
1022         state[3][3] = in[15];
1023
1024         // Perform the necessary number of rounds. The round key is added first.
1025         // The last round does not perform the MixColumns step.
1026         if (keysize > 128) {
1027                 if (keysize > 192) {
1028                         AddRoundKey(state,&key[56]);
1029                         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[52]);InvMixColumns(state);
1030                         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[48]);InvMixColumns(state);
1031                 }
1032                 else {
1033                         AddRoundKey(state,&key[48]);
1034                 }
1035                 InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[44]);InvMixColumns(state);
1036                 InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[40]);InvMixColumns(state);
1037         }
1038         else {
1039                 AddRoundKey(state,&key[40]);
1040         }
1041         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[36]);InvMixColumns(state);
1042         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[32]);InvMixColumns(state);
1043         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[28]);InvMixColumns(state);
1044         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[24]);InvMixColumns(state);
1045         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[20]);InvMixColumns(state);
1046         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[16]);InvMixColumns(state);
1047         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[12]);InvMixColumns(state);
1048         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[8]);InvMixColumns(state);
1049         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[4]);InvMixColumns(state);
1050         InvShiftRows(state);InvSubBytes(state);AddRoundKey(state,&key[0]);
1051
1052         // Copy the state to the output array.
1053         out[0] = state[0][0];
1054         out[1] = state[1][0];
1055         out[2] = state[2][0];
1056         out[3] = state[3][0];
1057         out[4] = state[0][1];
1058         out[5] = state[1][1];
1059         out[6] = state[2][1];
1060         out[7] = state[3][1];
1061         out[8] = state[0][2];
1062         out[9] = state[1][2];
1063         out[10] = state[2][2];
1064         out[11] = state[3][2];
1065         out[12] = state[0][3];
1066         out[13] = state[1][3];
1067         out[14] = state[2][3];
1068         out[15] = state[3][3];
1069 }
1070
1071 /*******************
1072 ** AES DEBUGGING FUNCTIONS
1073 *******************/
1074 /*
1075 // This prints the "state" grid as a linear hex string.
1076 void print_state(BYTE state[][4])
1077 {
1078         int idx,idx2;
1079
1080         for (idx=0; idx < 4; idx++)
1081                 for (idx2=0; idx2 < 4; idx2++)
1082                         printf("%02x",state[idx2][idx]);
1083         printf("\n");
1084 }
1085
1086 // This prints the key (4 consecutive ints) used for a given round as a linear hex string.
1087 void print_rnd_key(WORD key[])
1088 {
1089         int idx;
1090
1091         for (idx=0; idx < 4; idx++)
1092                 printf("%08x",key[idx]);
1093         printf("\n");
1094 }
1095 */