Алгоритм AES-256 Размер блока 128 бит Размер ключа 256 бит Число раунд

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/* Алгоритм AES-256
Размер блока - 128 бит
Размер ключа - 256 бит
Число раундов - 10 */
#define AES_KEY_SIZE 32
#define AES_BLOCK_SIZE 16
#define AES_ROUNDS 10
#define AES_EXPAND_KEY_SIZE ((AES_ROUNDS+1)*AES_BLOCK_SIZE)
struct aes_key
{
unsigned char k[AES_EXPAND_KEY_SIZE]; /* 240 байт */
};
unsigned char aes_sbox[] = {
0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16,
};
unsigned char aes_invsbox[] = {
0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
};
/* Процедуры шифрования */
/* Вычисляем расширеный ключ шифрования
key - указатель на 32-х байтный буфер */
void aes_expand(struct aes_key* exp_key, unsigned char* key)
{
unsigned char t[4], c, k = 1;
int i;
/* копируем первые 32 байта */
for(i = 0; i < AES_KEY_SIZE; i++)
exp_key->k[i] = key[i];
i = AES_KEY_SIZE;
while(i < AES_EXPAND_KEY_SIZE) {
/* копируем предыдущее слово во временную переменную */
t[0] = exp_key->k[i - 4];
t[1] = exp_key->k[i - 3];
t[2] = exp_key->k[i - 2];
t[3] = exp_key->k[i - 1];
if(!(i & 0x1F)) {
/* вращаем слово */
c = t[0];
t[0] = t[1]; t[1] = t[2]; t[2] = t[3];
t[3] = c;
/* нелинейная подстановка */
t[0] = aes_sbox[t[0]];
t[1] = aes_sbox[t[1]];
t[2] = aes_sbox[t[2]];
t[3] = aes_sbox[t[3]];
t[0] ^= k; k <<= 1;
} else if((i & 0x1F) == 0x10) {
/* только для AES с 256-и битным ключом */
t[0] = aes_sbox[t[0]];
t[1] = aes_sbox[t[1]];
t[2] = aes_sbox[t[2]];
t[3] = aes_sbox[t[3]];
}
/* записываем новое слово */
exp_key->k[i] = exp_key->k[i - AES_KEY_SIZE] ^ t[0]; i++;
exp_key->k[i] = exp_key->k[i - AES_KEY_SIZE] ^ t[1]; i++;
exp_key->k[i] = exp_key->k[i - AES_KEY_SIZE] ^ t[2]; i++;
exp_key->k[i] = exp_key->k[i - AES_KEY_SIZE] ^ t[3]; i++;
}
}
/* Нелинейная подстановка */
void aes_sub_bytes(unsigned char* state)
{
int i;
for(i = 0; i < AES_BLOCK_SIZE; i++)
state[i] = aes_sbox[state[i]];
}
/* Перестановка строк матрицы */
void aes_shift_rows(unsigned char* state)
{
unsigned char t = state[1];
/* вторая строка */
state[1] = state[5];
state[5] = state[9];
state[9] = state[13];
state[13] = t;
/* третья строка */
t = state[2];
state[2] = state[10];
state[10] = t;
t = state[6];
state[6] = state[14];
state[14] = t;
/* четвертая строка */
t = state[15];
state[15] = state[11];
state[11] = state[7];
state[7] = state[3];
state[3] = t;
}
/* Перестановка столбцов */
void aes_mix_columns(unsigned char* state)
{
unsigned char tmp, tm, t;
int i;
for(i = 0; i < 4; i++) { /* для каждого столбца */
t = state[i << 2];
tmp = t ^ state[(i<<2)+1] ^ state[(i<<2)+2] ^ state[(i<<2)+3];
/* первый элемент */
tm = t ^ state[(i << 2) + 1];
tm = (tm & 0x80) ? (tm << 1) ^ 0x1B : tm << 1;
state[i << 2] ^= tm ^ tmp;
/* второй элемент */
tm = state[(i << 2) + 1] ^ state[(i << 2) + 2];
tm = (tm & 0x80) ? (tm << 1) ^ 0x1B: tm << 1;
state[(i << 2) + 1] ^= tm ^ tmp;
/* третий элемент */
tm = state[(i << 2) + 2] ^ state[(i << 2) + 3];
tm = (tm & 0x80) ? (tm << 1) ^ 0x1B: tm << 1;
state[(i << 2) + 2] ^= tm ^ tmp;
/* четвертый элемент */
tm = state[(i << 2) + 3] ^ t;
tm = (tm & 0x80) ? (tm << 1) ^ 0x1B: tm << 1;
state[(i << 2) + 3] ^= tm ^ tmp;
}
}
/* Сложение с ключом */
void aes_add_round_key(struct aes_key* key, unsigned char* state, int* delta)
{
int i, t = *delta;
for(i = 0; i < AES_BLOCK_SIZE; i++)
state[i] ^= key->k[t++];
*delta = t;
}
/* Процедуры дешифрования */
/* Нелинейная подстановка */
void inv_sub_bytes(unsigned char* state)
{
int i;
for(i = 0; i < AES_BLOCK_SIZE; i++)
state[i] = aes_invsbox[state[i]];
}
/* Перестановка строк матрицы */
void inv_shift_rows(unsigned char* state)
{
unsigned char t = state[7];
/* вторая строка */
state[7] = state[6];
state[6] = state[5];
state[5] = state[4];
state[4] = t;
for (int i =0;i<3;i++)
{
/* третья строка */
t = state[11];
state[11] = state[10];
state[10] = state[9];
state[9] = state[8];
state[8] = t;
}
for ( int i = 0; i<4;i++)
{
/* четвертая строка */
t = state[15];
state[15] = state[14];
state[14] = state[13];
state[13] = state[12];
state[12] = t;
}
}
/* Перестановка столбцов */
void inv_mix_columns(unsigned char* state)
{
unsigned char t[4];
int i;
for(i = 0; i < 4; i++)
{
/* для каждого столбца */
t[0] = state[(i << 2)];
t[1] = state[(i << 2)+1];
t[2] = state[(i << 2)+2];
t[3] = state[(i << 2)+3];
/* первый элемент */
state[i << 2] = (14*t[0])^(11*t[1])^(13*t[2])^(9*t[3]);
state[(i << 2)+1] = (9*t[0])^(14*t[1])^(11*t[2])^(13*t[3]);
state[(i << 2)+2] = (13*t[0])^(9*t[1])^(14*t[2])^(11*t[3]);
state[(i << 2)+3] = (11*t[0])^(13*t[1])^(9*t[2])^(14*t[3]);
}
}