devbox
代码领袖开发者
这个屌丝很懒，什么也没留下！
关注作者
热门标签
热门文章
当前位置:   article > 正文

AES-CMAC算法应用实例

作者：代码领袖开发者 | 2024-01-31 19:56:51

赞

踩

aes-cmac

算法应用背景：

在27解锁密钥服务中有时候会应用到其AEC-CMAC的加密，其原理是在诊断仪发送27 01 给到ECU之后，ECU会产生一串随机数后反馈给诊断仪，诊断仪接着根据固定的KEY对随机数进行加密，得到加密后的数据Encrypt,诊断仪通过27 02 Encrypt发送给ECU，ECU则对发送出去的随机数同样进行ASE-CMAC的加密得到Encrypt1，之后Encrypt1与27 02的Encrypt进行对比，成功则返回67 02 ，失败则返回NRC 35 36等。

算法应用具体要求：

1.采用AES-CMAC的算法

2.密钥长度128bit，数据填充参考AEC-CMAC，并参考RFC4493

以上网络上其实也有相关的计算源码。

现在我直接放上可以执行的C代码，以供有需要的人进行查阅。

  1. #include <stdio.h>
  2. #include <stdint.h>
  3. #include <string.h>
  4.  
  5. //
  6.  
  7. typedef struct{
  8.     uint32_t eK[44], dK[44];    // encKey, decKey
  9.     int Nr; // 10 rounds
  10. }AesKey;
  11. void printHex(uint8_t *ptr, int len, char *tag);
  12. #define BLOCKSIZE 16  //AES-128分组长度为16字节
  13. typedef unsigned char uint8_t;
  14. // uint8_t y[4] -> uint32_t x
  15. #define LOAD32H(x, y) \
  16.   do { (x) = ((uint32_t)((y)[0] & 0xff)<<24) | ((uint32_t)((y)[1] & 0xff)<<16) | \
  17.              ((uint32_t)((y)[2] & 0xff)<<8)  | ((uint32_t)((y)[3] & 0xff));} while(0)
  18.  
  19. // uint32_t x -> uint8_t y[4]
  20. #define STORE32H(x, y) \
  21.   do { (y)[0] = (uint8_t)(((x)>>24) & 0xff); (y)[1] = (uint8_t)(((x)>>16) & 0xff);   \
  22.        (y)[2] = (uint8_t)(((x)>>8) & 0xff); (y)[3] = (uint8_t)((x) & 0xff); } while(0)
  23.  
  24. // 从uint32_t x中提取从低位开始的第n个字节
  25. #define BYTE(x, n) (((x) >> (8 * (n))) & 0xff)
  26.  
  27. /* used for keyExpansion */
  28. // 字节替换然后循环左移1位
  29. #define MIX(x) (((S[BYTE(x, 2)] << 24) & 0xff000000) ^ ((S[BYTE(x, 1)] << 16) & 0xff0000) ^ \
  30.                 ((S[BYTE(x, 0)] << 8) & 0xff00) ^ (S[BYTE(x, 3)] & 0xff))
  31.  
  32. // uint32_t x循环左移n位
  33. #define ROF32(x, n)  (((x) << (n)) | ((x) >> (32-(n))))
  34. // uint32_t x循环右移n位
  35. #define ROR32(x, n)  (((x) >> (n)) | ((x) << (32-(n))))
  36.  
  37. /* for 128-bit blocks, Rijndael never uses more than 10 rcon values */
  38. // AES-128轮常量
  39. static const uint32_t rcon[10] = {
  40.         0x01000000UL, 0x02000000UL, 0x04000000UL, 0x08000000UL, 0x10000000UL,
  41.         0x20000000UL, 0x40000000UL, 0x80000000UL, 0x1B000000UL, 0x36000000UL
  42. };
  43. // S盒
  44. unsigned char S[256] = {
  45.         0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
  46.         0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
  47.         0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
  48.         0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
  49.         0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
  50.         0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
  51.         0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
  52.         0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
  53.         0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
  54.         0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
  55.         0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
  56.         0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
  57.         0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
  58.         0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
  59.         0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
  60.         0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16
  61. };
  62.  
  63. //逆S盒
  64. unsigned char inv_S[256] = {
  65.         0x52, 0x09, 0x6A, 0xD5, 0x30, 0x36, 0xA5, 0x38, 0xBF, 0x40, 0xA3, 0x9E, 0x81, 0xF3, 0xD7, 0xFB,
  66.         0x7C, 0xE3, 0x39, 0x82, 0x9B, 0x2F, 0xFF, 0x87, 0x34, 0x8E, 0x43, 0x44, 0xC4, 0xDE, 0xE9, 0xCB,
  67.         0x54, 0x7B, 0x94, 0x32, 0xA6, 0xC2, 0x23, 0x3D, 0xEE, 0x4C, 0x95, 0x0B, 0x42, 0xFA, 0xC3, 0x4E,
  68.         0x08, 0x2E, 0xA1, 0x66, 0x28, 0xD9, 0x24, 0xB2, 0x76, 0x5B, 0xA2, 0x49, 0x6D, 0x8B, 0xD1, 0x25,
  69.         0x72, 0xF8, 0xF6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xD4, 0xA4, 0x5C, 0xCC, 0x5D, 0x65, 0xB6, 0x92,
  70.         0x6C, 0x70, 0x48, 0x50, 0xFD, 0xED, 0xB9, 0xDA, 0x5E, 0x15, 0x46, 0x57, 0xA7, 0x8D, 0x9D, 0x84,
  71.         0x90, 0xD8, 0xAB, 0x00, 0x8C, 0xBC, 0xD3, 0x0A, 0xF7, 0xE4, 0x58, 0x05, 0xB8, 0xB3, 0x45, 0x06,
  72.         0xD0, 0x2C, 0x1E, 0x8F, 0xCA, 0x3F, 0x0F, 0x02, 0xC1, 0xAF, 0xBD, 0x03, 0x01, 0x13, 0x8A, 0x6B,
  73.         0x3A, 0x91, 0x11, 0x41, 0x4F, 0x67, 0xDC, 0xEA, 0x97, 0xF2, 0xCF, 0xCE, 0xF0, 0xB4, 0xE6, 0x73,
  74.         0x96, 0xAC, 0x74, 0x22, 0xE7, 0xAD, 0x35, 0x85, 0xE2, 0xF9, 0x37, 0xE8, 0x1C, 0x75, 0xDF, 0x6E,
  75.         0x47, 0xF1, 0x1A, 0x71, 0x1D, 0x29, 0xC5, 0x89, 0x6F, 0xB7, 0x62, 0x0E, 0xAA, 0x18, 0xBE, 0x1B,
  76.         0xFC, 0x56, 0x3E, 0x4B, 0xC6, 0xD2, 0x79, 0x20, 0x9A, 0xDB, 0xC0, 0xFE, 0x78, 0xCD, 0x5A, 0xF4,
  77.         0x1F, 0xDD, 0xA8, 0x33, 0x88, 0x07, 0xC7, 0x31, 0xB1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xEC, 0x5F,
  78.         0x60, 0x51, 0x7F, 0xA9, 0x19, 0xB5, 0x4A, 0x0D, 0x2D, 0xE5, 0x7A, 0x9F, 0x93, 0xC9, 0x9C, 0xEF,
  79.         0xA0, 0xE0, 0x3B, 0x4D, 0xAE, 0x2A, 0xF5, 0xB0, 0xC8, 0xEB, 0xBB, 0x3C, 0x83, 0x53, 0x99, 0x61,
  80.         0x17, 0x2B, 0x04, 0x7E, 0xBA, 0x77, 0xD6, 0x26, 0xE1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0C, 0x7D
  81. };
  82.  
  83. /* copy in[16] to state[4][4] */
  84. int loadStateArray(uint8_t (*state)[4], const uint8_t *in) {
  85. 	int i,j;
  86.     for (i = 0; i < 4; ++i) {
  87.         for (j = 0; j < 4; ++j) {
  88.             state[j][i] = *in++;
  89.         }
  90.     }
  91.     return 0;
  92. }
  93.  
  94. /* copy state[4][4] to out[16] */
  95. int storeStateArray(uint8_t (*state)[4], uint8_t *out) {
  96. 	int i,j;	
  97.     for (i = 0; i < 4; ++i) {
  98.         for (j = 0; j < 4; ++j) {
  99.             *out++ = state[j][i];
  100.         }
  101.     }
  102.     return 0;
  103. }
  104. //秘钥扩展
  105. int keyExpansion(const uint8_t *key, uint32_t keyLen, AesKey *aesKey) {
  106.  
  107.     if (NULL == key || NULL == aesKey){
  108.         printf("keyExpansion param is NULL\n");
  109.         return -1;
  110.     }
  111.  
  112.     if (keyLen != 16){
  113.         printf("keyExpansion keyLen = %d, Not support.\n", keyLen);
  114.         return -1;
  115.     }
  116.  
  117.     uint32_t *w = aesKey->eK;  //加密秘钥
  118.     uint32_t *v = aesKey->dK;  //解密秘钥
  119.  
  120.     /* keyLen is 16 Bytes, generate uint32_t W[44]. */
  121.  
  122.     /* W[0-3] */
  123.     int i;
  124.     for (i = 0; i < 4; ++i) {
  125.         LOAD32H(w[i], key + 4*i);
  126.     }
  127.  
  128.     /* W[4-43] */
  129.     
  130.     for (i = 0; i < 10; ++i) {
  131.         w[4] = w[0] ^ MIX(w[3]) ^ rcon[i];
  132.         w[5] = w[1] ^ w[4];
  133.         w[6] = w[2] ^ w[5];
  134.         w[7] = w[3] ^ w[6];
  135.         w += 4;
  136.     }
  137.  
  138.     w = aesKey->eK+44 - 4;
  139.     //解密秘钥矩阵为加密秘钥矩阵的倒序，方便使用，把ek的11个矩阵倒序排列分配给dk作为解密秘钥
  140.     //即dk[0-3]=ek[41-44], dk[4-7]=ek[37-40]... dk[41-44]=ek[0-3]
  141.     int j;
  142.     for (j = 0; j < 11; ++j) {
  143.  
  144.         for (i = 0; i < 4; ++i) {
  145.             v[i] = w[i];
  146.         }
  147.         w -= 4;
  148.         v += 4;
  149.     }
  150.  
  151.     return 0;
  152. }
  153.  
  154. // 轮秘钥加
  155. int addRoundKey(uint8_t (*state)[4], const uint32_t *key) {
  156.     uint8_t k[4][4];
  157. int i;
  158. int j;
  159.     /* i: row, j: col */
  160.     for (i = 0; i < 4; ++i) {
  161.         for (j = 0; j < 4; ++j) {
  162.             k[i][j] = (uint8_t) BYTE(key[j], 3 - i);  /* 把 uint32 key[4] 先转换为矩阵 uint8 k[4][4] */
  163.             state[i][j] ^= k[i][j];
  164.         }
  165.     }
  166.  
  167.     return 0;
  168. }
  169.  
  170. //字节替换
  171. int subBytes(uint8_t (*state)[4]) {
  172.     /* i: row, j: col */
  173.     	int i,j;
  174.     for (i = 0; i < 4; ++i) {
  175.         for (j = 0; j < 4; ++j) {
  176.             state[i][j] = S[state[i][j]]; //直接使用原始字节作为S盒数据下标
  177.         }
  178.     }
  179.  
  180.     return 0;
  181. }
  182.  
  183. //逆字节替换
  184. int invSubBytes(uint8_t (*state)[4]) {
  185.     /* i: row, j: col */
  186.     	int i,j;
  187.     for (i = 0; i < 4; ++i) {
  188.         for (j = 0; j < 4; ++j) {
  189.             state[i][j] = inv_S[state[i][j]];
  190.         }
  191.     }
  192.     return 0;
  193. }
  194.  
  195. //行移位
  196. int shiftRows(uint8_t (*state)[4]) {
  197.     uint32_t block[4] = {0};
  198.  
  199.     /* i: row */
  200.     int i;
  201.     for (i = 0; i < 4; ++i) {
  202.     //便于行循环移位，先把一行4字节拼成uint_32结构，移位后再转成独立的4个字节uint8_t
  203.         LOAD32H(block[i], state[i]);
  204.         block[i] = ROF32(block[i], 8*i);
  205.         STORE32H(block[i], state[i]);
  206.     }
  207.     return 0;
  208. }
  209.  
  210. //逆行移位
  211. int invShiftRows(uint8_t (*state)[4]) {
  212.     uint32_t block[4] = {0};
  213.     /* i: row */
  214.     	int i;
  215.     for (i = 0; i < 4; ++i) {
  216.         LOAD32H(block[i], state[i]);
  217.         block[i] = ROR32(block[i], 8*i);
  218.         STORE32H(block[i], state[i]);
  219.     }
  220.     return 0;
  221. }
  222.  
  223. /* Galois Field (256) Multiplication of two Bytes */
  224. // 两字节的伽罗华域乘法运算
  225. uint8_t GMul(uint8_t u, uint8_t v) {
  226.     uint8_t p = 0;
  227. 	int i;
  228.     for (i = 0; i < 8; ++i) {
  229.         if (u & 0x01) {    //
  230.             p ^= v;
  231.         }
  232.  
  233.         int flag = (v & 0x80);
  234.         v <<= 1;
  235.         if (flag) {
  236.             v ^= 0x1B; /* x^8 + x^4 + x^3 + x + 1 */
  237.         }
  238.         u >>= 1;
  239.     }
  240.     return p;
  241. }
  242.  
  243. // 列混合
  244. int mixColumns(uint8_t (*state)[4]) {
  245.     uint8_t tmp[4][4];
  246.     uint8_t M[4][4] = {{0x02, 0x03, 0x01, 0x01},
  247.                        {0x01, 0x02, 0x03, 0x01},
  248.                        {0x01, 0x01, 0x02, 0x03},
  249.                        {0x03, 0x01, 0x01, 0x02}};
  250.     /* copy state[4][4] to tmp[4][4] */
  251.     	int i,j;
  252.     for (i = 0; i < 4; ++i) {
  253.         for (j = 0; j < 4; ++j){
  254.             tmp[i][j] = state[i][j];
  255.         }
  256.     }
  257.  
  258.     for (i = 0; i < 4; ++i) {
  259.         for (j = 0; j < 4; ++j) {  //伽罗华域加法和乘法
  260.             state[i][j] = GMul(M[i][0], tmp[0][j]) ^ GMul(M[i][1], tmp[1][j])
  261.                         ^ GMul(M[i][2], tmp[2][j]) ^ GMul(M[i][3], tmp[3][j]);
  262.         }
  263.     }
  264.     return 0;
  265. }
  266.  
  267. // 逆列混合
  268. int invMixColumns(uint8_t (*state)[4]) {
  269.     uint8_t tmp[4][4];
  270.     uint8_t M[4][4] = {{0x0E, 0x0B, 0x0D, 0x09},
  271.                        {0x09, 0x0E, 0x0B, 0x0D},
  272.                        {0x0D, 0x09, 0x0E, 0x0B},
  273.                        {0x0B, 0x0D, 0x09, 0x0E}};  //使用列混合矩阵的逆矩阵
  274. 	int i,j;
  275.     /* copy state[4][4] to tmp[4][4] */
  276.     for (i = 0; i < 4; ++i) {
  277.         for ( j = 0; j < 4; ++j){
  278.             tmp[i][j] = state[i][j];
  279.         }
  280.     }
  281.  
  282.     for ( i = 0; i < 4; ++i) {
  283.         for ( j = 0; j < 4; ++j) {
  284.             state[i][j] = GMul(M[i][0], tmp[0][j]) ^ GMul(M[i][1], tmp[1][j])
  285.                           ^ GMul(M[i][2], tmp[2][j]) ^ GMul(M[i][3], tmp[3][j]);
  286.         }
  287.     }
  288.  
  289.     return 0;
  290. }
  291.  
  292. // AES-128加密接口，输入key应为16字节长度，输入长度应该是16字节整倍数，
  293. // 这样输出长度与输入长度相同，函数调用外部为输出数据分配内存
  294. int aesEncrypt(const uint8_t *key, uint32_t keyLen, const uint8_t *pt, uint8_t *ct, uint32_t len) {
  295.  
  296.     AesKey aesKey;
  297.     uint8_t *pos = ct;
  298.     const uint32_t *rk = aesKey.eK;  //解密秘钥指针
  299.     uint8_t out[BLOCKSIZE] = {0};
  300.     uint8_t actualKey[16] = {0};
  301.     uint8_t state[4][4] = {0};
  302.  
  303.     if (NULL == key || NULL == pt || NULL == ct){
  304.         printf("param err.\n");
  305.         return -1;
  306.     }
  307.  
  308.     if (keyLen > 16){
  309.         printf("keyLen must be 16.\n");
  310.         return -1;
  311.     }
  312.  
  313.     if (len % BLOCKSIZE){
  314.         printf("inLen is invalid.\n");
  315.         return -1;
  316.     }
  317.  
  318.     memcpy(actualKey, key, keyLen);
  319.     keyExpansion(actualKey, 16, &aesKey);  // 秘钥扩展
  320. 	int i;
  321. 	// 使用ECB模式循环加密多个分组长度的数据
  322.     for ( i = 0; i < len; i += BLOCKSIZE) {
  323. 		// 把16字节的明文转换为4x4状态矩阵来进行处理
  324.         loadStateArray(state, pt);
  325.         // 轮秘钥加
  326.         addRoundKey(state, rk);
  327. 	int j;
  328.         for (j = 1; j < 10; ++j) {
  329.             rk += 4;
  330.             subBytes(state);   // 字节替换
  331.             shiftRows(state);  // 行移位
  332.             mixColumns(state); // 列混合
  333.             addRoundKey(state, rk); // 轮秘钥加
  334.         }
  335.  
  336.         subBytes(state);    // 字节替换
  337.         shiftRows(state);  // 行移位
  338.         // 此处不进行列混合
  339.         addRoundKey(state, rk+4); // 轮秘钥加
  340. 		
  341. 		// 把4x4状态矩阵转换为uint8_t一维数组输出保存
  342.         storeStateArray(state, pos);
  343.  
  344.         pos += BLOCKSIZE;  // 加密数据内存指针移动到下一个分组
  345.         pt += BLOCKSIZE;   // 明文数据指针移动到下一个分组
  346.         rk = aesKey.eK;    // 恢复rk指针到秘钥初始位置
  347.     }
  348.     return 0;
  349. }
  350.  
  351. // AES128解密， 参数要求同加密
  352. int aesDecrypt(const uint8_t *key, uint32_t keyLen, const uint8_t *ct, uint8_t *pt, uint32_t len) {
  353.     AesKey aesKey;
  354.     uint8_t *pos = pt;
  355.     const uint32_t *rk = aesKey.dK;  //解密秘钥指针
  356.     uint8_t out[BLOCKSIZE] = {0};
  357.     uint8_t actualKey[16] = {0};
  358.     uint8_t state[4][4] = {0};
  359.  
  360.     if (NULL == key || NULL == ct || NULL == pt){
  361.         printf("param err.\n");
  362.         return -1;
  363.     }
  364.  
  365.     if (keyLen > 16){
  366.         printf("keyLen must be 16.\n");
  367.         return -1;
  368.     }
  369.  
  370.     if (len % BLOCKSIZE){
  371.         printf("inLen is invalid.\n");
  372.         return -1;
  373.     }
  374.  
  375.     memcpy(actualKey, key, keyLen);
  376.     keyExpansion(actualKey, 16, &aesKey);  //秘钥扩展，同加密
  377. 	int i,j;
  378.     for ( i = 0; i < len; i += BLOCKSIZE) {
  379.         // 把16字节的密文转换为4x4状态矩阵来进行处理
  380.         loadStateArray(state, ct);
  381.         // 轮秘钥加，同加密
  382.         addRoundKey(state, rk);
  383.  
  384.         for ( j = 1; j < 10; ++j) {
  385.             rk += 4;
  386.             invShiftRows(state);    // 逆行移位
  387.             invSubBytes(state);     // 逆字节替换，这两步顺序可以颠倒
  388.             addRoundKey(state, rk); // 轮秘钥加，同加密
  389.             invMixColumns(state);   // 逆列混合
  390.         }
  391.  
  392.         invSubBytes(state);   // 逆字节替换
  393.         invShiftRows(state);  // 逆行移位
  394.         // 此处没有逆列混合
  395.         addRoundKey(state, rk+4);  // 轮秘钥加，同加密
  396.  
  397.         storeStateArray(state, pos);  // 保存明文数据
  398.         pos += BLOCKSIZE;  // 输出数据内存指针移位分组长度
  399.         ct += BLOCKSIZE;   // 输入数据内存指针移位分组长度
  400.         rk = aesKey.dK;    // 恢复rk指针到秘钥初始位置
  401.     }
  402.     return 0;
  403. }
  404.  
  405. void printHex(uint8_t *ptr, int len, char *tag) {
  406.     printf("%s\ndata[%d]: ", tag, len);
  407.     	int i;
  408.     for ( i = 0; i < len; ++i) {
  409.         printf("%.2X ", *ptr++);
  410.     }
  411.     printf("\n");
  412. }
  413.  
  414.  
  415. //
  416.   /* For CMAC Calculation */
  417.   unsigned char const_Rb[16] = {
  418.       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  419.       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x87
  420.   };
  421.   unsigned char const_Zero[16] = {
  422.       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
  423.       0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
  424.   };
  425.  
  426.   /* Basic Functions */
  427.  
  428.   void xor_128(unsigned char *a, unsigned char *b, unsigned char *out)
  429.   {
  430.       int i;
  431.       for (i=0;i<16; i++)
  432.       {
  433.           out[i] = a[i] ^ b[i];
  434.       }
  435.   }
  436.  
  437.   void print_hex(char *str, unsigned char *buf, int len)
  438.   {
  439.       int     i;
  440.  
  441.       for ( i=0; i<len; i++ ) {
  442.           if ( (i % 16) == 0 && i != 0 ) printf(str);
  443.           printf("%02x", buf[i]);
  444.           if ( (i % 4) == 3 ) printf(" ");
  445.           if ( (i % 16) == 15 ) printf("\n");
  446.       }
  447.       if ( (i % 16) != 0 ) printf("\n");
  448.   }
  449.   void print128(unsigned char *bytes)
  450.   {
  451.       int         j;
  452.       for (j=0; j<16;j++) {
  453.           printf("%02x",bytes[j]);
  454.           if ( (j%4) == 3 ) printf(" ");
  455.       }
  456.   }
  457.  
  458.   void print96(unsigned char *bytes)
  459.   {
  460.       int         j;
  461.       for (j=0; j<12;j++) {
  462.           printf("%02x",bytes[j]);
  463.           if ( (j%4) == 3 ) printf(" ");
  464.       }
  465.   }
  466.  
  467.   /* AES-CMAC Generation Function */
  468.  
  469.   void leftshift_onebit(unsigned char *input,unsigned char *output)
  470.   {
  471.       int         i;
  472.       unsigned char overflow = 0;
  473.  
  474.       for ( i=15; i>=0; i-- ) {
  475.           output[i] = input[i] << 1;
  476.           output[i] |= overflow;
  477.           overflow = (input[i] & 0x80)?1:0;
  478.       }
  479.       return;
  480.   }
  481.  
  482.   void generate_subkey(unsigned char *key, unsigned char *K1, unsigned
  483.                        char *K2)
  484.   {
  485.       unsigned char L[16];
  486.       unsigned char Z[16];
  487.       unsigned char tmp[16];
  488.       int i;
  489.  
  490.       for ( i=0; i<16; i++ ) Z[i] = 0;
  491.  
  492.       aesEncrypt(key,16,Z,L,16);
  493.  
  494.       if ( (L[0] & 0x80) == 0 ) { /* If MSB(L) = 0, then K1 = L << 1 */
  495.           leftshift_onebit(L,K1);
  496.       } else {    /* Else K1 = ( L << 1 ) (+) Rb */
  497.  leftshift_onebit(L,tmp);
  498.           xor_128(tmp,const_Rb,K1);
  499.       }
  500.  
  501.       if ( (K1[0] & 0x80) == 0 ) {
  502.           leftshift_onebit(K1,K2);
  503.       } else {
  504.           leftshift_onebit(K1,tmp);
  505.           xor_128(tmp,const_Rb,K2);
  506.       }
  507.       return;
  508.   }
  509.  
  510.   void padding ( unsigned char *lastb, unsigned char *pad, int length )
  511.   {
  512.       int         j;
  513.  
  514.       /* original last block */
  515.       for ( j=0; j<16; j++ ) {
  516.           if ( j < length ) {
  517.               pad[j] = lastb[j];
  518.           } else if ( j == length ) {
  519.               pad[j] = 0x80;
  520.           } else {
  521.               pad[j] = 0x00;
  522.           }
  523.       }
  524.   }
  525.  
  526.   void AES_CMAC ( unsigned char *key, unsigned char *input, int length,
  527.                   unsigned char *mac )
  528.   {
  529.       unsigned char       X[16],Y[16], M_last[16], padded[16];
  530.       unsigned char       K1[16], K2[16];
  531.       int         n, i, flag;
  532.       generate_subkey(key,K1,K2);
  533.  
  534.       n = (length+15) / 16;       /* n is number of rounds */
  535.  
  536.       if ( n == 0 ) {
  537.           n = 1;
  538.           flag = 0;
  539.       } else {
  540.           if ( (length%16) == 0 ) { /* last block is a complete block */
  541.               flag = 1;
  542.           } else { /* last block is not complete block */
  543.               flag = 0;
  544.           }
  545.            }
  546.  
  547.       if ( flag ) { /* last block is complete block */
  548.           xor_128(&input[16*(n-1)],K1,M_last);
  549.       } else {
  550.           padding(&input[16*(n-1)],padded,length%16);
  551.           xor_128(padded,K2,M_last);
  552.       }
  553.  
  554.       for ( i=0; i<16; i++ ) X[i] = 0;
  555.       for ( i=0; i<n-1; i++ ) {
  556.           xor_128(X,&input[16*i],Y); /* Y := Mi (+) X  */
  557.           aesEncrypt(key,16,Y,X,16);      /* X := AES-128(KEY, Y); */
  558.       }
  559.  
  560.       xor_128(X,M_last,Y);
  561.       aesEncrypt(key,16,Y,X,16);
  562.  
  563.       for ( i=0; i<16; i++ ) {
  564.           mac[i] = X[i];
  565.       }
  566.   }
  567.  
  568.   int main()
  569.   {
  570.       unsigned char L[16], K1[16], K2[16], T[16], TT[12];
  571.       unsigned char M[64] = {
  572.           0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
  573.           0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff,
  574.           0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c,
  575.           0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
  576.           0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11,
  577.           0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
  578.           0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17,
  579.           0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10
  580.       };
  581.       unsigned char key[16] = {
  582.           0x3d, 0x2e, 0x6d, 0xe2, 0xa1, 0x25, 0x17, 0xba,
  583.           0xc5, 0xb3, 0x1b, 0xbd, 0x0e, 0x7e, 0x3b, 0x54
  584.       };
  585.  
  586.       printf("--------------------------------------------------\n");
  587.       printf("K              "); print128(key); printf("\n");
  588.  
  589.       printf("\nSubkey Generation\n");
  590.       aesEncrypt(key,16,const_Zero,L,16);
  591.       printf("AES_128(key,0) "); print128(L); printf("\n");
  592.       generate_subkey(key,K1,K2);
  593.        printf("K1             "); print128(K1); printf("\n");
  594.       printf("K2             "); print128(K2); printf("\n");
  595.  
  596.       printf("\nExample 1: len = 0\n");
  597.       printf("M              "); printf("<empty string>\n");
  598.  
  599.       AES_CMAC(key,M,0,T);
  600.       printf("AES_CMAC       "); print128(T); printf("\n");
  601.  
  602.       printf("\nExample 2: len = 16\n");
  603.       printf("M              "); print_hex("                ",M,16);
  604.       AES_CMAC(key,M,16,T);
  605.       printf("AES_CMAC       "); print128(T); printf("\n");
  606.       printf("\nExample 3: len = 40\n");
  607.       printf("M              "); print_hex("               ",M,40);
  608.       AES_CMAC(key,M,40,T);
  609.       printf("AES_CMAC       "); print128(T); printf("\n");
  610.  
  611.       printf("\nExample 4: len = 64\n");
  612.       printf("M              "); print_hex("               ",M,64);
  613.       AES_CMAC(key,M,64,T);
  614.       printf("AES_CMAC       "); print128(T); printf("\n");
  615.  
  616.       printf("--------------------------------------------------\n");
  617.  
  618.       return 0;
  619.   }
  620.

以上代码中，Key[16]为密钥，其是一个固定值，M则为需要加密的数据，上面最大支持64byte，根据自己项目实际情况去使用，其中int main里面写了0 ，16 ，40 ，64的时候执行的结果。

 AES_CMAC(key,M,64,T)函数中，形参Key表示密钥，M表示需要加密的数据，64表示填充为64byte的形式，T则表示加密之后得到的结果。以上根据自己要求来即可得到相应的结果。

实际测试结果：

以Key为  0x3d, 0x2e, 0x6d, 0xe2, 0xa1, 0x25, 0x17, 0xba,0xc5, 0xb3, 0x1b, 0xbd, 0x0e, 0x7e, 0x3b, 0x54为例，加密数据为0x00-0xff的16byte，加密长度为16byte，得到的结果为

a51eb807 bc447f92 fa33b569 9acb4cdf

以上即为AES-CMAC的计算方法，仅供大家参考。

最后附上可以在线进行AES-CMAC的算法网站，供大家自己去验证：

CryptoJS extension by artjomb

声明：本文内容由网友自发贡献，不代表【wpsshop博客】立场，版权归原作者所有，本站不承担相应法律责任。如您发现有侵权的内容，请联系我们。转载请注明出处：https://www.wpsshop.cn/article/detail/51892
推荐阅读
相关标签

Copyright © 2003-2013 www.wpsshop.cn 版权所有，并保留所有权利。

  

闽ICP备14008679号