AES.cpp

#include "AES.h"
#include <algorithm>

// Cache alignment
#ifdef _WIN32
 #define ALIGNED(x) __declspec(align(x))
#elif defined(__GNUC__) || defined(__GNUG__)
 #define ALIGNED(x) __attribute__(aligned(x))
#else
 #define ALIGNED(x)
#endif 

using namespace AES_NAMESPACE;


ALIGNED(256) 
const uint8_t AES_NAMESPACE::S_BOX[SBOX_SIZE][SBOX_SIZE] = {
  0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
  0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
  0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
  0x04, 0xc4, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
  0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
  0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
  0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
  0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
  0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
  0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
  0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
  0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
  0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
  0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
  0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
  0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16
};


ALIGNED(256) 
const uint8_t AES_NAMESPACE::INVERSE_S_BOX[SBOX_SIZE][SBOX_SIZE] = {
  82,    9, 106, 213,  48,  54, 165,  56, 191,  64, 163, 158, 129, 243, 215, 251,
  124, 227,  57, 130, 155,  47, 255, 135,  52, 142,  67,  68, 196, 222, 233, 203,
   84, 123, 148,  50, 166, 194,  35,  61, 238,  76, 149,  11,  66, 250, 195,  78,
    8,  46, 161, 102,  40, 217,  36, 178, 118,  91, 162,  73, 109, 139, 209,  37,
  114, 248, 246, 100, 134, 104, 152,  22, 212, 164,  92, 204,  93, 101, 182, 146,
  108, 112,  72,  80, 253, 237, 185, 218,  94,  21,  70,  87, 167, 141, 157, 132,
  144, 216, 171,   0, 140, 188, 211,  10, 247, 228,  88,   5, 184, 179,  69,   6,
  208,  44,  30, 143, 202,  63,  15,   2, 193, 175, 189,   3,   1,  19, 138, 107,
   58, 145,  17,  65,  79, 103, 220, 234, 151, 242, 207, 206, 240, 180, 230, 115,
  150, 172, 116,  34, 231, 173,  53, 133, 226, 249,  55, 232,  28, 117, 223, 110,
   71, 241,  26, 113,  29,  41, 197, 137, 111, 183,  98,  14, 170,  24, 190,  27,
  252,  86,  62,  75, 198, 210, 121,  32, 154, 219, 192, 254, 120, 205,  90, 244,
   31, 221, 168,  51, 136,   7, 199, 204, 177,  18,  16,  89,  39, 128, 236,  95,
   96,  81, 127, 169,  25, 181,  74,  13,  45, 229, 122, 159, 147, 201, 156, 239,
  160, 224,  59,  77, 174,  42, 245, 176, 200, 235, 187,  60, 131,  83, 153,  97,
   23,  43,   4, 126, 186, 119, 214,  38, 225, 105,  20,  99,  85,  33,  12, 125
};



AES::AES()
{
    
}

AES::~AES()
{
    
}

uint32_t AES::encrypt(uint8_t *buffer, uint32_t size, uint8_t* key)
{
    //check if block size if %16
    //either pad or throw error
    return 0;
}

void AES::debugPrint()
{
    printf("\n");
    for (int x = 0; x < 4; x++)
    {
        for (int y = 0; y < 4; y++)
        {
            printf("%#04x ", block[x][y]);
        }
        printf("\n");
    }
}

void AES::GenerateInverseSBox(uint8_t sBox[SBOX_SIZE][SBOX_SIZE], uint8_t output[SBOX_SIZE][SBOX_SIZE])
{
		for (int i = 0; i < SBOX_SIZE; i++) {
				for (int j = 0; j < SBOX_SIZE; j++) {
						uint8_t val = sBox[i][j];
						uint8_t x = (val >> 4) & 0x0f;
						uint8_t y = val & 0x0f;
						uint8_t pos = (j & 0x0f);
						pos |= (i & 0x0f) << 4;
						output[x][y] = pos;
				}
		}
}

void AES::SubBytes(uint8_t *buffer) {
    
    for(int i = 0; i < MATRIX_SIZE; ++i) {
        for(int j = 0; j < MATRIX_SIZE; ++j) {
          block[j][i] = buffer[i * MATRIX_SIZE + j];
        }
    }  
}


void AES::SBox() 
{
    uint8_t x_coord = 0, y_coord = 0; // x & y coord of the Rijndael S-Box
    for (int i = 0; i < MATRIX_SIZE; i++) {
        for (int j = 0; j < MATRIX_SIZE; j++) {
            x_coord = (block[i][j] & 0xf0) >> 4; // upper 4 bits
            y_coord = block[i][j] & 0x0f; // lower 4 bits
            block[i][j] = S_BOX[x_coord][y_coord];
        }
    }
}

void AES::InverseSBox()
{
		for (int i = 0; i < MATRIX_SIZE; i++) {
				for (int j = 0; j < MATRIX_SIZE; j++) {
						uint8_t x = (block[i][j] & 0xf0) >> 4;
						uint8_t y = (block[i][j] & 0x0f);
						block[i][j] = INVERSE_S_BOX[x][y];
				}
		}
}

void AES::ShiftRows() {
    /**
    Iterate through rows of matrix starting at row 1
    */
    for (int y = 1; y < MATRIX_SIZE; y++) {
        /*
        Move elements between index 0 and y to the end of the array, shifts
        elements that are being replaced towards the beginning of the array
        */
        std::rotate(&block[y][0], &block[y][y], &block[y][MATRIX_SIZE]);
    }
}

void AES::InverseShiftRows() {
		/**
		Iterate through rows of matrix starting at row 1
		*/
		for (int y = 1; y < MATRIX_SIZE; y++) {
				/**
				Move elements between the end of the array and end of the array - y to
				the beginning of the array
				*/
				std::rotate(std::reverse_iterator<uint8_t*>(std::end(block[y])),
						std::reverse_iterator<uint8_t*>(std::end(block[y])) + y,
						std::reverse_iterator<uint8_t*>(block[y]));
		}
}

/**
 * Performs the mix Column step of AES. Takes a column from an array and multiplies it against
 * the galois field
 * @param stateColumn current column being multiplied
 */
void mixColumns(uint8_t *stateColumn) {
  uint8_t colOrg[4];//for the parts that are only being multiplied by 1
  uint8_t colByTwo[4];//for the parts being multiplied by 2 or 3
  uint8_t upperBit;//for storing the leftmost bit
  /**
  * Iterating through the state column, copying it to colOrg. The values from colOrg are
  * multiplied by 2 and stored in colByTwo and conditionally xored by 0x1b.
  */
  for (int c = 0; c < 4; c++) {
      colOrg[c] = stateColumn[c];
      upperBit = stateColumn[c] >> 7;
      colByTwo[c] = stateColumn[c] << 1;
      if (upperBit == 1) {
        colByTwo[c] = colByTwo[c] ^ 0x1b;
      }
  }
  /**
  * Values multiplies by 2 and 3 are taken from coldAdj. Values multiplied by 1
  * are taken from col1. An extra value is added in for the valued multiplied by 3
  */
  stateColumn[0] = colByTwo[0] ^ (colByTwo[1] ^ colOrg[1]) ^ colOrg[2] ^ colOrg[3];
  stateColumn[1] = colOrg[0] ^ colByTwo[1] ^ (colByTwo[2] ^ colOrg[2]) ^ colOrg[3];
  stateColumn[2] = colOrg[0] ^ colOrg[1] ^ colByTwo[2] ^ (colByTwo[3] ^ colOrg[3]);
  stateColumn[3] = (colByTwo[0] ^ colOrg[0]) ^ colOrg[1] ^ colOrg[2] ^ colByTwo[3];
}