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