aes.cpp

aes和des加密的小程序：可以加密文件

    temp[0] =
        Te0[(byte)(w[0])] ^
        Te1[(byte)(w[1] >>  8)] ^
        Te2[(byte)(w[2] >> 16)] ^
        Te3[(byte)(w[3] >> 24)];

    temp[1] =
        Te0[(byte)(w[1])] ^
        Te1[(byte)(w[2] >>  8)] ^
        Te2[(byte)(w[3] >> 16)] ^
        Te3[(byte)(w[0] >> 24)];

    temp[2] =
        Te0[(byte)(w[2])] ^
        Te1[(byte)(w[3] >>  8)] ^
        Te2[(byte)(w[0] >> 16)] ^
        Te3[(byte)(w[1] >> 24)];

    temp[3] =
        Te0[(byte)(w[3])] ^
        Te1[(byte)(w[0] >>  8)] ^
        Te2[(byte)(w[1] >> 16)] ^
        Te3[(byte)(w[2] >> 24)];

    for (i = 0; i < 4; i++)
        w[i] = temp[i];
}

//逆向列混淆加上移位
static void InvMixColumns_ShiftRows(word w[4])
{
    int i;
    word temp[4];
    temp[0] =
        Td0[(byte)(w[0])] ^
        Td1[(byte)(w[3] >>  8)] ^
        Td2[(byte)(w[2] >> 16)] ^
        Td3[(byte)(w[1] >> 24)];

    temp[1] =
        Td0[(byte)(w[1])] ^
        Td1[(byte)(w[0] >>  8)] ^
        Td2[(byte)(w[3] >> 16)] ^
        Td3[(byte)(w[2] >> 24)];

    temp[2] =
        Td0[(byte)(w[2])] ^
        Td1[(byte)(w[1] >>  8)] ^
        Td2[(byte)(w[0] >> 16)] ^
        Td3[(byte)(w[3] >> 24)];

    temp[3] =
        Td0[(byte)(w[3])] ^
        Td1[(byte)(w[2] >>  8)] ^
        Td2[(byte)(w[1] >> 16)] ^
        Td3[(byte)(w[0] >> 24)];

    for (i = 0; i < 4; i++)
        w[i] = temp[i];
}

//逆向列混淆
static void InvMixColumns(word w[4])
{
    int i;
    word temp[4];
    temp[0] =
        Td0[(byte)(w[0])] ^
        Td1[(byte)(w[0] >>  8)] ^
        Td2[(byte)(w[0] >> 16)] ^
        Td3[(byte)(w[0] >> 24)];

    temp[1] =
        Td0[(byte)(w[1])] ^
        Td1[(byte)(w[1] >>  8)] ^
        Td2[(byte)(w[1] >> 16)] ^
        Td3[(byte)(w[1] >> 24)];

    temp[2] =
        Td0[(byte)(w[2])] ^
        Td1[(byte)(w[2] >>  8)] ^
        Td2[(byte)(w[2] >> 16)] ^
        Td3[(byte)(w[2] >> 24)];

    temp[3] =
        Td0[(byte)(w[3])] ^
        Td1[(byte)(w[3] >>  8)] ^
        Td2[(byte)(w[3] >> 16)] ^
        Td3[(byte)(w[3] >> 24)];

    for (i = 0; i < 4; i++)
        w[i] = temp[i];
}

//轮密钥加
static void AddRoundKey(word w[4], const word key[4])
{
    w[0] ^= key[0];
    w[1] ^= key[1];
    w[2] ^= key[2];
    w[3] ^= key[3];
}

//密钥扩展算法
static void KeyExpansion(const byte key[16], word w[44])
{
    word temp;
    int i;
    for (i = 0; i < 4; i++) {
/*         printf("%d\n", key[i]); */
        w[i] = Byte2Word((byte *)&key[4*i]);

/*         printf("%08X\n", w[i]); */
    }
    for (i = 4; i < 44; i++) {
        temp = w[i-1];
        if (i%4 == 0)
            temp = SubWord(ROTWORD(temp)) ^ Rcon[i/4];
        w[i] = w[i-4] ^ temp;
    }
}

//AES加密函数
void AES_encrypt(const byte in[16], byte out[16], const byte key[16])
{
    word state[4], temp[4], key_ex[44];
    int i;

    for (i = 0; i < 4; i++)
        state[i] = Byte2Word(&in[i*4]);

    KeyExpansion(key, key_ex);

    AddRoundKey(state, &key_ex[0]);

    for (i = 1; i < 10; i++) {
        MixColumns_ShifRows(state);
        AddRoundKey(state, &key_ex[i*4]);
    }

    temp[0] =
        sbox[(byte)(state[0])] |
        sbox[(byte)(state[1] >>  8)] <<  8 |
        sbox[(byte)(state[2] >> 16)] << 16 |
        sbox[(byte)(state[3] >> 24)] << 24;

    temp[1] =
        sbox[(byte)(state[1])] |
        sbox[(byte)(state[2] >>  8)] <<  8 |
        sbox[(byte)(state[3] >> 16)] << 16 |
        sbox[(byte)(state[0] >> 24)] << 24;

    temp[2] =
        sbox[(byte)(state[2])] |
        sbox[(byte)(state[3] >>  8)] <<  8 |
        sbox[(byte)(state[0] >> 16)] << 16 |
        sbox[(byte)(state[1] >> 24)] << 24;

    temp[3] =
        sbox[(byte)(state[3])] |
        sbox[(byte)(state[0] >>  8)] <<  8 |
        sbox[(byte)(state[1] >> 16)] << 16 |
        sbox[(byte)(state[2] >> 24)] << 24;

    AddRoundKey(temp, &key_ex[i*4]);

    for (i = 0; i < 4; i++)
        Word2Byte(temp[i], &out[i*4]);
}

//AES解密函数
void AES_decrypt(const byte in[16], byte out[16], const byte key[16])
{
    word state[4], temp[4], key_ex[44];
    int i;

    for (i = 0; i < 4; i++)
        state[i] = Byte2Word(&in[i*4]);

    KeyExpansion(key, key_ex);
    for (i = 1; i < 10; i++) {
        InvMixColumns(&key_ex[i*4]);
    }

    AddRoundKey(state, &key_ex[10 * 4]);

    for (i = 9; i > 0; i--) {
        state[0] = InvSubWord(state[0]);
        state[1] = InvSubWord(state[1]);
        state[2] = InvSubWord(state[2]);
        state[3] = InvSubWord(state[3]);

        InvMixColumns_ShiftRows(state);
        AddRoundKey(state, &key_ex[i*4]);
    }

    temp[0] =
        invsbox[(byte)(state[0])] |
        invsbox[(byte)(state[3] >>  8)] <<  8 |
        invsbox[(byte)(state[2] >> 16)] << 16 |
        invsbox[(byte)(state[1] >> 24)] << 24;

    temp[1] =
        invsbox[(byte)(state[1])] |
        invsbox[(byte)(state[0] >>  8)] <<  8 |
        invsbox[(byte)(state[3] >> 16)] << 16 |
        invsbox[(byte)(state[2] >> 24)] << 24;

    temp[2] =
        invsbox[(byte)(state[2])] |
        invsbox[(byte)(state[1] >>  8)] <<  8 |
        invsbox[(byte)(state[0] >> 16)] << 16 |
        invsbox[(byte)(state[3] >> 24)] << 24;

    temp[3] =
        invsbox[(byte)(state[3])] |
        invsbox[(byte)(state[2] >>  8)] <<  8 |
        invsbox[(byte)(state[1] >> 16)] << 16 |
        invsbox[(byte)(state[0] >> 24)] << 24;

    AddRoundKey(temp, &key_ex[i*4]);

    for (i = 0; i < 4; i++)
        Word2Byte(temp[i], &out[i*4]);
}

/* int main() */
/* { */
/*     byte a[16] = {0, 1, 2, 3, 4, 5, 6, 7, */
/*                   8, 9, 10, 11, 12, 13, 14, 15}; */
/*     word w[44]; */

/*     word b[4] = {0x3d7c6ebd, 0x9e77b5f2, 0x6e21610b, 0x89b6108b}; */

/*     byte key[16] = {0x2B, 0x7E, 0x15, 0x16, 0x28, 0xAE, 0xD2, 0xA6, */
/*                     0xAB, 0xF7, 0x15, 0x88, 0x09, 0xCF, 0x4F, 0x3C }; */
/*     int i; */

/*     byte input[] = {0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, */
/*                     0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff}; */
/*     byte ckey[] = {0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, */
/*                    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f}; */
/*     byte output[16]; */


/*     clock_t start, finish; */
/*     double duration; */

/*     start = clock(); */
/*     for (i = 0; i < 1000000; i++) */
/*         AES_encrypt(input, output, ckey); */
/*     finish = clock(); */
/*     duration = (double)(finish - start) / CLOCKS_PER_SEC; */
/*     printf("%lf\n", duration); */

/*     for (i = 0; i < 16; i++) */
/*         printf("%02x", output[i]); */
/*     printf("\n"); */
    
/*     return 0; */
/* } */