AES源码(基于C语言)

整个加解密过程还未完全理解，暂时留个记号，以后有机会再慢慢体会。

代码如下：

#pragma once

#define uint32_t unsigned int

#define uint8_t unsigned char

int aesTest();

#pragma pack(1)

typedef struct {
    uint32_t eK[44], dK[44];    // encKey, decKey
    int Nr; // 10 rounds
}AesKey;

#pragma pack()

//
// Created by Liming Shao on 2018/4/24.
//

#include "AES.h"
#include 
#include 

#define BLOCKSIZE 16

#define LOAD32H(x, y) \
  do { (x) = ((uint32_t)((y)[0] & 0xff)<<24) | ((uint32_t)((y)[1] & 0xff)<<16) | \
             ((uint32_t)((y)[2] & 0xff)<<8)  | ((uint32_t)((y)[3] & 0xff));} while(0)

#define STORE32H(x, y) \
  do { (y)[0] = (uint8_t)(((x)>>24) & 0xff); (y)[1] = (uint8_t)(((x)>>16) & 0xff);   \
       (y)[2] = (uint8_t)(((x)>>8) & 0xff); (y)[3] = (uint8_t)((x) & 0xff); } while(0)

/* extract a byte */
#define BYTE(x, n) (((x) >> (8 * (n))) & 0xff)

/* used for keyExpansion */
#define MIX(x) (((S[BYTE(x, 2)] << 24) & 0xff000000) ^ ((S[BYTE(x, 1)] << 16) & 0xff0000) ^ \
                ((S[BYTE(x, 0)] << 8) & 0xff00) ^ (S[BYTE(x, 3)] & 0xff))

#define ROF32(x, n)  (((x) << (n)) | ((x) >> (32-(n))))

#define ROR32(x, n)  (((x) >> (n)) | ((x) << (32-(n))))

/* for 128-bit blocks, Rijndael never uses more than 10 rcon values */
static const uint32_t rcon[10] = {
        0x01000000UL, 0x02000000UL, 0x04000000UL, 0x08000000UL, 0x10000000UL,
        0x20000000UL, 0x40000000UL, 0x80000000UL, 0x1B000000UL, 0x36000000UL
};

unsigned char S[256] = {
        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 inv_S[256] = {
        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
};

/* copy in[16] to state[4][4] */
int loadStateArray(uint8_t(*state)[4], const uint8_t* in) {
    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            state[j][i] = *in++;
        }
    }
    return 0;
}

/* copy state[4][4] to out[16] */
int storeStateArray(uint8_t(*state)[4], uint8_t* out) {
    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            *out++ = state[j][i];
        }
    }
    return 0;
}

int keyExpansion(const uint8_t* key, uint32_t keyLen, AesKey* aesKey) {

    if (NULL == key || NULL == aesKey) {
        printf("keyExpansion param is NULL\n");
        return -1;
    }

    if (keyLen != 16) {
        printf("keyExpansion keyLen = %d, Not support.\n", keyLen);
        return -1;
    }

    uint32_t* w = aesKey->eK;
    uint32_t* v = aesKey->dK;

    /* keyLen is 16 Bytes, generate uint32_t W[44]. */

    /* W[0-3] */
    for (int i = 0; i < 4; ++i) {
        LOAD32H(w[i], key + 4 * i);
    }

    /* W[4-43] */
    for (int i = 0; i < 10; ++i) {
        w[4] = w[0] ^ MIX(w[3]) ^ rcon[i];
        w[5] = w[1] ^ w[4];
        w[6] = w[2] ^ w[5];
        w[7] = w[3] ^ w[6];
        w += 4;
    }

    w = aesKey->eK + 44 - 4;
    for (int j = 0; j < 11; ++j) {

        for (int i = 0; i < 4; ++i) {
            v[i] = w[i];
        }
        w -= 4;
        v += 4;
    }

    return 0;
}

int addRoundKey(uint8_t(*state)[4], const uint32_t* key) {
    uint8_t k[4][4];

    /* i: row, j: col */
    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            k[i][j] = (uint8_t)BYTE(key[j], 3 - i);  /* copy uint32 key[4] to uint8 k[4][4] */
            state[i][j] ^= k[i][j];
        }
    }

    return 0;
}

int subBytes(uint8_t(*state)[4]) {
    /* i: row, j: col */
    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            state[i][j] = S[state[i][j]];
        }
    }

    return 0;
}

int invSubBytes(uint8_t(*state)[4]) {
    /* i: row, j: col */
    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            state[i][j] = inv_S[state[i][j]];
        }
    }

    return 0;
}

int shiftRows(uint8_t(*state)[4]) {
    uint32_t block[4] = { 0 };

    /* i: row */
    for (int i = 0; i < 4; ++i) {
        LOAD32H(block[i], state[i]);
        block[i] = ROF32(block[i], 8 * i);
        STORE32H(block[i], state[i]);
    }

    return 0;
}

int invShiftRows(uint8_t(*state)[4]) {
    uint32_t block[4] = { 0 };

    /* i: row */
    for (int i = 0; i < 4; ++i) {
        LOAD32H(block[i], state[i]);
        block[i] = ROR32(block[i], 8 * i);
        STORE32H(block[i], state[i]);
    }

    return 0;
}

/* Galois Field (256) Multiplication of two Bytes */
uint8_t GMul(uint8_t u, uint8_t v) {
    uint8_t p = 0;

    for (int i = 0; i < 8; ++i) {
        if (u & 0x01) {    //
            p ^= v;
        }

        int flag = (v & 0x80);
        v <<= 1;
        if (flag) {
            v ^= 0x1B; /* x^8 + x^4 + x^3 + x + 1 */
        }

        u >>= 1;
    }

    return p;
}

int mixColumns(uint8_t(*state)[4]) {
    uint8_t tmp[4][4];
    uint8_t M[4][4] = { {0x02, 0x03, 0x01, 0x01},
                       {0x01, 0x02, 0x03, 0x01},
                       {0x01, 0x01, 0x02, 0x03},
                       {0x03, 0x01, 0x01, 0x02} };

    /* copy state[4][4] to tmp[4][4] */
    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            tmp[i][j] = state[i][j];
        }
    }

    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            state[i][j] = GMul(M[i][0], tmp[0][j]) ^ GMul(M[i][1], tmp[1][j])
                ^ GMul(M[i][2], tmp[2][j]) ^ GMul(M[i][3], tmp[3][j]);
        }
    }

    return 0;
}

int invMixColumns(uint8_t(*state)[4]) {
    uint8_t tmp[4][4];
    uint8_t M[4][4] = { {0x0E, 0x0B, 0x0D, 0x09},
                       {0x09, 0x0E, 0x0B, 0x0D},
                       {0x0D, 0x09, 0x0E, 0x0B},
                       {0x0B, 0x0D, 0x09, 0x0E} };

    /* copy state[4][4] to tmp[4][4] */
    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            tmp[i][j] = state[i][j];
        }
    }

    for (int i = 0; i < 4; ++i) {
        for (int j = 0; j < 4; ++j) {
            state[i][j] = GMul(M[i][0], tmp[0][j]) ^ GMul(M[i][1], tmp[1][j])
                ^ GMul(M[i][2], tmp[2][j]) ^ GMul(M[i][3], tmp[3][j]);
        }
    }

    return 0;
}

int aesEncrypt(const uint8_t* key, uint32_t keyLen, const uint8_t* pt, uint8_t* ct, uint32_t len) {

    AesKey aesKey;
    uint8_t* pos = ct;
    const uint32_t* rk = aesKey.eK;
    uint8_t out[BLOCKSIZE] = { 0 };
    uint8_t actualKey[16] = { 0 };
    uint8_t state[4][4] = { 0 };

    if (NULL == key || NULL == pt || NULL == ct) {
        printf("param err.\n");
        return -1;
    }

    if (keyLen > 16) {
        printf("keyLen must be 16.\n");
        return -1;
    }

    if (len % BLOCKSIZE) {
        printf("inLen is invalid.\n");
        return -1;
    }

    memcpy(actualKey, key, keyLen);
    keyExpansion(actualKey, 16, &aesKey);

    for (int i = 0; i < len; i += BLOCKSIZE) {

        loadStateArray(state, pt);
        addRoundKey(state, rk);

        for (int j = 1; j < 10; ++j) {
            rk += 4;
            subBytes(state);
            shiftRows(state);
            mixColumns(state);
            addRoundKey(state, rk);
        }

        subBytes(state);
        shiftRows(state);
        addRoundKey(state, rk + 4);

        storeStateArray(state, pos);

        pos += BLOCKSIZE;
        pt += BLOCKSIZE;
        rk = aesKey.eK;
    }
    return 0;
}

int aesDecrypt(const uint8_t* key, uint32_t keyLen, const uint8_t* ct, uint8_t* pt, uint32_t len) {
    AesKey aesKey;
    uint8_t* pos = pt;
    const uint32_t* rk = aesKey.dK;
    uint8_t out[BLOCKSIZE] = { 0 };
    uint8_t actualKey[16] = { 0 };
    uint8_t state[4][4] = { 0 };

    if (NULL == key || NULL == ct || NULL == pt) {
        printf("param err.\n");
        return -1;
    }

    if (keyLen > 16) {
        printf("keyLen must be 16.\n");
        return -1;
    }

    if (len % BLOCKSIZE) {
        printf("inLen is invalid.\n");
        return -1;
    }

    memcpy(actualKey, key, keyLen);
    keyExpansion(actualKey, 16, &aesKey);

    for (int i = 0; i < len; i += BLOCKSIZE) {
        loadStateArray(state, ct);
        addRoundKey(state, rk);

        for (int j = 1; j < 10; ++j) {
            rk += 4;
            invShiftRows(state);
            invSubBytes(state);
            addRoundKey(state, rk);
            invMixColumns(state);
        }

        invSubBytes(state);
        invShiftRows(state);
        addRoundKey(state, rk + 4);

        storeStateArray(state, pos);
        pos += BLOCKSIZE;
        ct += BLOCKSIZE;
        rk = aesKey.dK;
    }
    return 0;
}



//
// Created by Liming Shao on 4/30/2018.
//


void printHex(const uint8_t* ptr, int len, char* tag) {
    printf("%s\ndata[%d]: ", tag, len);
    for (int i = 0; i < len; ++i) {
        printf("%.2X ", *ptr++);
    }
    printf("\n");
}

void printState(uint8_t(*state)[4], char* tag) {
    printf("%s\n", tag);
    for (int i = 0; i < 4; ++i) {
        printf("%.2X %.2X %.2X %.2X\n", state[i][0], state[i][1], state[i][2], state[i][3]);
    }
    printf("\n");
}



//
// Created by Liming Shao on 2018/4/24.
//




int aesTest() {

    // case 1
    const uint8_t key[16] = { 0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c };
    const uint8_t pt[16] = { 0x32, 0x43, 0xf6, 0xa8, 0x88, 0x5a, 0x30, 0x8d, 0x31, 0x31, 0x98, 0xa2, 0xe0, 0x37, 0x07, 0x34 };
    uint8_t ct[16] = { 0 };
    uint8_t plain[16] = { 0 };

    aesEncrypt(key, 16, pt, ct, 16);
    printHex(pt, 16, "plain data:");
    printf("expect cipher:\n39 25 84 1D 02 DC 09 FB DC 11 85 97 19 6A 0B 32\n");

    printHex(ct, 16, "after encryption:");

    aesDecrypt(key, 16, ct, plain, 16);
    printHex(plain, 16, "after decryption:");

    // case 2
    const uint8_t key2[] = "1234567890123456";
    const uint8_t* data = (uint8_t*)"abcdefghijklmnopqrstuvwxyz123456";
    uint8_t ct2[32] = { 0 };
    uint8_t plain2[32] = { 0 };
    aesEncrypt(key2, 16, data, ct2, 32);

    printf("\nplain text:\n%s\n", data);
    printf("expect ciphertext:\nfcad715bd73b5cb0488f840f3bad7889\n");
    printHex(ct2, 32, "after encryption:");

    aesDecrypt(key2, 16, ct2, plain2, 32);
    printHex(plain2, 32, "after decryption:");

    printf("output plain text\n");
    for (int i = 0; i < 32; ++i) {
        printf("%c ", plain2[i]);
    }

    return 0;
}

参考链接：

https://blog.csdn.net/shaosunrise/article/details/80219950