[非原创] 常用加密算法整理 AES/SSL（一）

前言：

     在伟大的计算机科学家研究下，发明了许多的加密算法，以下做个简答的描述：

一、分类

     加密算法分为两种：单向加密、双向加密。

     单向加密，不可逆的加密算法，只能加密不能解密；

     双向加密，由对称性加密算法和非对称性加密算法；

          对称性加密：约定好的密钥和统一的加密算法，双发对数据进行加密、解密；

               // 加密解密用的是同样的“钥匙”

               张无忌将一个加了锁的盒子寄给了赵敏，

               赵敏收到盒子后用相同的钥匙打开，然后同样的方式寄回给张无忌；

          非对称性加密：公钥和私钥组成，公钥加密私钥解密；

               // 加密解密用的是不同的“钥匙”

               张无忌和赵敏各有自己的盒子。赵敏要跟张无忌秘密通信，她先让张无忌把盒子打开通过邮局发给她。

               赵敏拿到盒子后放入信息锁上，然后发给张无忌。张无忌就可以用他自己的钥匙打开了。回复的话就用同样的方式。

 

二、SSL（HTTPS 协议）加密原理

     SSL 就是典型的非对称性加密方式，结合上面的描述，简单描述一下 SSL 原理：

     1、当你的浏览器向服务器请求一个安全的网页(通常是 https://)；

     2、服务器就把它的证书和（非对称性加密的）公钥发回来；

     3、浏览器检查证书是不是由可以信赖的机构颁发的，确认证书有效和此证书是此网站的；

     4、浏览器使用服务器给的公钥加密了一个随机对称密钥 （浏览器随机生成一个对称性密钥，采用服务器的公钥进行加密），

               包括加密的URL一起发送到服务器

     5、服务器用自己的私钥解密了浏览器发送的密钥，然后用这个对称性加密的密钥解密浏览器的请求信息；

     6、服务器用你发的对称钥匙给你请求的网页加密。你也有相同的钥匙就可以解密发回来的网页了；

     // 非对称算法在加密和解密时用的是不同的钥匙。

         信息接受者有两把钥匙：一把“公匙”，一把“私匙”。

         公匙是给信息发送者用来加密的，私匙是自己用来解密的这样最大的好处是：

         不必通过不安全的渠道发送私密的东西。公匙本来就是给别人用的，不用藏好。

         你的私匙在你产生私匙的电脑里保存着。

     

     // 如果还是没能完全理解，把非对称性加密中的 "张无忌、赵敏" 分别换成客户端（浏览器）与服务器（Web）

 

三、常用的算法

     对称性加密算法：AES、DES、3DES

     非对称性加密算法：RSA、DSA、ECC

     线性散列算法（不是加密算法）：MD5、SHA1、HMAC

四、AES 加密算法

     

     AES 又称“矩阵加密算法”其原理采用字节矩阵上进行“或与非”的操作（置换和替代），

     达到数据被重新排列、或者替换成为另一个完全不相同的数据；

     从而达到可以采用相同的密钥进行“回转”；

     AES 加密的区块长度固定为 128、192、256 位（bit）；

     

     （附破图一张）

     

     AES 加密过程涉及到 4 种操作：

          字节替代（SubBytes）

          行移位（ShiftRows）

          列混淆（MixColumns）

          轮密钥加（AddRoundKey）

     解密过程分别为对应的逆操作，

     由于每一步操作都是可逆的，按照相反的顺序进行解密即可恢复明文。 

     字节替代（SubBytes）

          字节代替的主要功能是通过一个固定的“矩阵”（想象成 Excel 表格上的数据）

          完成一个字节到另外一个字节的映射。

    行移位（ShiftRows）

          行移位的功能是实现一个 4x4 矩阵内部字节之间的置换。

          其实应该就是高级编程不常用的“或与非 ^ & | ”操作；

          采用正向行移位和逆向行移位到达预期结果；

 　列混淆（MixColumns）

          利用GF(28)域上算术特性的一个代替。

          具体没有深究，有点小复杂，总之一句话代替就是 TM 在矩阵上根据数学公式搞来搞去；

/*
 * Advanced Encryption Standard
 * @author Dani Huertas
 * @email huertas.dani@gmail.com
 *
 * Based on the document FIPS PUB 197
 */
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

/*
 * Addition in GF(2^8)
 * http://en.wikipedia.org/wiki/Finite_field_arithmetic
 */
uint8_t gadd(uint8_t a, uint8_t b) {
    return a^b;
}

/*
 * Subtraction in GF(2^8)
 * http://en.wikipedia.org/wiki/Finite_field_arithmetic
 */
uint8_t gsub(uint8_t a, uint8_t b) {
    return a^b;
}

/*
 * Multiplication in GF(2^8)
 * http://en.wikipedia.org/wiki/Finite_field_arithmetic
 * Irreducible polynomial m(x) = x8 + x4 + x3 + x + 1
 */
uint8_t gmult(uint8_t a, uint8_t b) {

    uint8_t p = 0, i = 0, hbs = 0;

    for (i = 0; i < 8; i++) {
        if (b & 1) {
            p ^= a;
        }

        hbs = a & 0x80;
        a <<= 1;
        if (hbs) a ^= 0x1b; // 0000 0001 0001 1011    
        b >>= 1;
    }

    return (uint8_t)p;
}

/*
 * Addition of 4 byte words
 * m(x) = x4+1
 */
void coef_add(uint8_t a[], uint8_t b[], uint8_t d[]) {

    d[0] = a[0]^b[0];
    d[1] = a[1]^b[1];
    d[2] = a[2]^b[2];
    d[3] = a[3]^b[3];
}

/*
 * Multiplication of 4 byte words
 * m(x) = x4+1
 */
void coef_mult(uint8_t *a, uint8_t *b, uint8_t *d) {

    d[0] = gmult(a[0],b[0])^gmult(a[3],b[1])^gmult(a[2],b[2])^gmult(a[1],b[3]);
    d[1] = gmult(a[1],b[0])^gmult(a[0],b[1])^gmult(a[3],b[2])^gmult(a[2],b[3]);
    d[2] = gmult(a[2],b[0])^gmult(a[1],b[1])^gmult(a[0],b[2])^gmult(a[3],b[3]);
    d[3] = gmult(a[3],b[0])^gmult(a[2],b[1])^gmult(a[1],b[2])^gmult(a[0],b[3]);
}

/*
 * The cipher Key.    
 */
int K;

/*
 * Number of columns (32-bit words) comprising the State. For this 
 * standard, Nb = 4.
 */
int Nb = 4;

/*
 * Number of 32-bit words comprising the Cipher Key. For this 
 * standard, Nk = 4, 6, or 8.
 */
int Nk;

/*
 * Number of rounds, which is a function of  Nk  and  Nb (which is 
 * fixed). For this standard, Nr = 10, 12, or 14.
 */
int Nr;

/*
 * S-box transformation table
 */
static uint8_t s_box[256] = {
    // 0     1     2     3     4     5     6     7     8     9     a     b     c     d     e     f
    0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, // 0
    0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, // 1
    0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, // 2
    0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, // 3
    0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, // 4
    0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, // 5
    0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, // 6
    0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, // 7
    0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, // 8
    0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, // 9
    0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, // a
    0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, // b
    0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, // c
    0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, // d
    0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, // e
    0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16};// f

/*
 * Inverse S-box transformation table
 */
static uint8_t inv_s_box[256] = {
    // 0     1     2     3     4     5     6     7     8     9     a     b     c     d     e     f
    0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, // 0
    0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, // 1
    0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, // 2
    0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25, // 3
    0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, // 4
    0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84, // 5
    0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06, // 6
    0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b, // 7
    0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73, // 8
    0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e, // 9
    0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, // a
    0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4, // b
    0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, // c
    0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, // d
    0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, // e
    0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d};// f


/*
 * Generates the round constant Rcon[i]
 */
uint8_t R[] = {0x02, 0x00, 0x00, 0x00};
 
uint8_t * Rcon(uint8_t i) {
    
    if (i == 1) {
        R[0] = 0x01; // x^(1-1) = x^0 = 1
    } else if (i > 1) {
        R[0] = 0x02;
        i--;
        while (i-1 > 0) {
            R[0] = gmult(R[0], 0x02);
            i--;
        }
    }
    
    return R;
}

/*
 * Transformation in the Cipher and Inverse Cipher in which a Round 
 * Key is added to the State using an XOR operation. The length of a 
 * Round Key equals the size of the State (i.e., for Nb = 4, the Round 
 * Key length equals 128 bits/16 bytes).
 */
void add_round_key(uint8_t *state, uint8_t *w, uint8_t r) {
    
    uint8_t c;
    
    for (c = 0; c < Nb; c++) {
        state[Nb*0+c] = state[Nb*0+c]^w[4*Nb*r+4*c+0];   //debug, so it works for Nb !=4 
        state[Nb*1+c] = state[Nb*1+c]^w[4*Nb*r+4*c+1];
        state[Nb*2+c] = state[Nb*2+c]^w[4*Nb*r+4*c+2];
        state[Nb*3+c] = state[Nb*3+c]^w[4*Nb*r+4*c+3];    
    }
}

/*
 * Transformation in the Cipher that takes all of the columns of the 
 * State and mixes their data (independently of one another) to 
 * produce new columns.
 */
void mix_columns(uint8_t *state) {

    uint8_t a[] = {0x02, 0x01, 0x01, 0x03}; // a(x) = {02} + {01}x + {01}x2 + {03}x3
    uint8_t i, j, col[4], res[4];

    for (j = 0; j < Nb; j++) {
        for (i = 0; i < 4; i++) {
            col[i] = state[Nb*i+j];
        }

        coef_mult(a, col, res);

        for (i = 0; i < 4; i++) {
            state[Nb*i+j] = res[i];
        }
    }
}

/*
 * Transformation in the Inverse Cipher that is the inverse of 
 * MixColumns().
 */
void inv_mix_columns(uint8_t *state) {

    uint8_t a[] = {0x0e, 0x09, 0x0d, 0x0b}; // a(x) = {0e} + {09}x + {0d}x2 + {0b}x3
    uint8_t i, j, col[4], res[4];

    for (j = 0; j < Nb; j++) {
        for (i = 0; i < 4; i++) {
            col[i] = state[Nb*i+j];
        }

        coef_mult(a, col, res);

        for (i = 0; i < 4; i++) {
            state[Nb*i+j] = res[i];
        }
    }
}

/*
 * Transformation in the Cipher that processes the State by cyclically 
 * shifting the last three rows of the State by different offsets. 
 */
void shift_rows(uint8_t *state) {

    uint8_t i, k, s, tmp;

    for (i = 1; i < 4; i++) {
        // shift(1,4)=1; shift(2,4)=2; shift(3,4)=3
        // shift(r, 4) = r;
        s = 0;
        while (s < i) {
            tmp = state[Nb*i+0];
            
            for (k = 1; k < Nb; k++) {
                state[Nb*i+k-1] = state[Nb*i+k];
            }

            state[Nb*i+Nb-1] = tmp;
            s++;
        }
    }
}

/*
 * Transformation in the Inverse Cipher that is the inverse of 
 * ShiftRows().
 */
void inv_shift_rows(uint8_t *state) {

    uint8_t i, k, s, tmp;

    for (i = 1; i < 4; i++) {
        s = 0;
        while (s < i) {
            tmp = state[Nb*i+Nb-1];
            
            for (k = Nb-1; k > 0; k--) {
                state[Nb*i+k] = state[Nb*i+k-1];
            }

            state[Nb*i+0] = tmp;
            s++;
        }
    }
}

/*
 * Transformation in the Cipher that processes the State using a non­
 * linear byte substitution table (S-box) that operates on each of the 
 * State bytes independently. 
 */
void sub_bytes(uint8_t *state) {

    uint8_t i, j;
    uint8_t row, col;

    for (i = 0; i < 4; i++) {
        for (j = 0; j < Nb; j++) {
            row = (state[Nb*i+j] & 0xf0) >> 4;
            col = state[Nb*i+j] & 0x0f;
            state[Nb*i+j] = s_box[16*row+col];
        }
    }
}

/*
 * Transformation in the Inverse Cipher that is the inverse of 
 * SubBytes().
 */
void inv_sub_bytes(uint8_t *state) {

    uint8_t i, j;
    uint8_t row, col;

    for (i = 0; i < 4; i++) {
        for (j = 0; j < Nb; j++) {
            row = (state[Nb*i+j] & 0xf0) >> 4;
            col = state[Nb*i+j] & 0x0f;
            state[Nb*i+j] = inv_s_box[16*row+col];
        }
    }
}

/*
 * Function used in the Key Expansion routine that takes a four-byte 
 * input word and applies an S-box to each of the four bytes to 
 * produce an output word.
 */
void sub_word(uint8_t *w) {

    uint8_t i;

    for (i = 0; i < 4; i++) {
        w[i] = s_box[16*((w[i] & 0xf0) >> 4) + (w[i] & 0x0f)];
    }
}

/*
 * Function used in the Key Expansion routine that takes a four-byte 
 * word and performs a cyclic permutation. 
 */
void rot_word(uint8_t *w) {

    uint8_t tmp;
    uint8_t i;

    tmp = w[0];

    for (i = 0; i < 3; i++) {
        w[i] = w[i+1];
    }

    w[3] = tmp;
}

/*
 * Key Expansion
 */
void key_expansion(uint8_t *key, uint8_t *w) {

    uint8_t tmp[4];
    uint8_t i, j;
    uint8_t len = Nb*(Nr+1);

    for (i = 0; i < Nk; i++) {
        w[4*i+0] = key[4*i+0];
        w[4*i+1] = key[4*i+1];
        w[4*i+2] = key[4*i+2];
        w[4*i+3] = key[4*i+3];
    }

    for (i = Nk; i < len; i++) {
        tmp[0] = w[4*(i-1)+0];
        tmp[1] = w[4*(i-1)+1];
        tmp[2] = w[4*(i-1)+2];
        tmp[3] = w[4*(i-1)+3];

        if (i%Nk == 0) {

            rot_word(tmp);
            sub_word(tmp);
            coef_add(tmp, Rcon(i/Nk), tmp);

        } else if (Nk > 6 && i%Nk == 4) {

            sub_word(tmp);

        }

        w[4*i+0] = w[4*(i-Nk)+0]^tmp[0];
        w[4*i+1] = w[4*(i-Nk)+1]^tmp[1];
        w[4*i+2] = w[4*(i-Nk)+2]^tmp[2];
        w[4*i+3] = w[4*(i-Nk)+3]^tmp[3];
    }
}

void cipher(uint8_t *in, uint8_t *out, uint8_t *w) {

    uint8_t state[4*Nb];
    uint8_t r, i, j;

    for (i = 0; i < 4; i++) {
        for (j = 0; j < Nb; j++) {
            state[Nb*i+j] = in[i+4*j];
        }
    }

    add_round_key(state, w, 0);

    for (r = 1; r < Nr; r++) {
        sub_bytes(state);
        shift_rows(state);
        mix_columns(state);
        add_round_key(state, w, r);
    }

    sub_bytes(state);
    shift_rows(state);
    add_round_key(state, w, Nr);

    for (i = 0; i < 4; i++) {
        for (j = 0; j < Nb; j++) {
            out[i+4*j] = state[Nb*i+j];
        }
    }
}

void inv_cipher(uint8_t *in, uint8_t *out, uint8_t *w) {

    uint8_t state[4*Nb];
    uint8_t r, i, j;

    for (i = 0; i < 4; i++) {
        for (j = 0; j < Nb; j++) {
            state[Nb*i+j] = in[i+4*j];
        }
    }

    add_round_key(state, w, Nr);

    for (r = Nr-1; r >= 1; r--) {
        inv_shift_rows(state);
        inv_sub_bytes(state);
        add_round_key(state, w, r);
        inv_mix_columns(state);
    }

    inv_shift_rows(state);
    inv_sub_bytes(state);
    add_round_key(state, w, 0);

    for (i = 0; i < 4; i++) {
        for (j = 0; j < Nb; j++) {
            out[i+4*j] = state[Nb*i+j];
        }
    }
}

int main(int argc, char *argv[]) {

    uint8_t i;

    /*
     * Appendix A - Key Expansion Examples
     */
     
    /* 128 bits */
    /* uint8_t key[] = {
        0x2b, 0x7e, 0x15, 0x16,
        0x28, 0xae, 0xd2, 0xa6,
        0xab, 0xf7, 0x15, 0x88,
        0x09, 0xcf, 0x4f, 0x3c}; */
    
    /* 192 bits */
    /* uint8_t key[] = {
        0x8e, 0x73, 0xb0, 0xf7,
        0xda, 0x0e, 0x64, 0x52,
        0xc8, 0x10, 0xf3, 0x2b,
        0x80, 0x90, 0x79, 0xe5,
        0x62, 0xf8, 0xea, 0xd2,
        0x52, 0x2c, 0x6b, 0x7b}; */
    
    /* 256 bits */
    /* uint8_t key[] = {
        0x60, 0x3d, 0xeb, 0x10,
        0x15, 0xca, 0x71, 0xbe,
        0x2b, 0x73, 0xae, 0xf0,
        0x85, 0x7d, 0x77, 0x81,
        0x1f, 0x35, 0x2c, 0x07,
        0x3b, 0x61, 0x08, 0xd7,
        0x2d, 0x98, 0x10, 0xa3,
        0x09, 0x14, 0xdf, 0xf4};
    */
    
    /* uint8_t in[] = {
        0x32, 0x43, 0xf6, 0xa8,
        0x88, 0x5a, 0x30, 0x8d,
        0x31, 0x31, 0x98, 0xa2,
        0xe0, 0x37, 0x07, 0x34}; // 128
    */

    /*
     * Appendix C - Example Vectors
     */

    /* 128 bit key */
    /* uint8_t key[] = {
        0x00, 0x01, 0x02, 0x03, 
        0x04, 0x05, 0x06, 0x07, 
        0x08, 0x09, 0x0a, 0x0b, 
        0x0c, 0x0d, 0x0e, 0x0f}; */
    
    /* 192 bit key */
    /* uint8_t key[] = {
        0x00, 0x01, 0x02, 0x03,
        0x04, 0x05, 0x06, 0x07,
        0x08, 0x09, 0x0a, 0x0b,
        0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13,
        0x14, 0x15, 0x16, 0x17}; */
    
    /* 256 bit key */
    uint8_t key[] = {
        0x00, 0x01, 0x02, 0x03,
        0x04, 0x05, 0x06, 0x07,
        0x08, 0x09, 0x0a, 0x0b,
        0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13,
        0x14, 0x15, 0x16, 0x17,
        0x18, 0x19, 0x1a, 0x1b,
        0x1c, 0x1d, 0x1e, 0x1f};

    uint8_t in[] = {
        0x00, 0x11, 0x22, 0x33,
        0x44, 0x55, 0x66, 0x77,
        0x88, 0x99, 0xaa, 0xbb,
        0xcc, 0xdd, 0xee, 0xff};
    
    uint8_t out[16]; // 128
    
    uint8_t *w; // expanded key

    switch (sizeof(key)) {
        default:
        case 16: Nk = 4; Nr = 10; break;
        case 24: Nk = 6; Nr = 12; break;
        case 32: Nk = 8; Nr = 14; break;
    }
    
    w = malloc(Nb*(Nr+1)*4);

    key_expansion(key, w);

    cipher(in /* in */, out /* out */, w /* expanded key */);

    printf("out:
");
    
    for (i = 0; i < 4; i++) {
        printf("%x %x %x %x ", out[4*i+0], out[4*i+1], out[4*i+2], out[4*i+3]);
    }

    printf("
");

    inv_cipher(out, in, w);

    printf("msg:
");
    for (i = 0; i < 4; i++) {
        printf("%x %x %x %x ", in[4*i+0], in[4*i+1], in[4*i+2], in[4*i+3]);
    }

    printf("
");

    exit(0);

}

   https://github.com/dhuertas/AES/blob/master/aes.c

参考自：

     http://blog.csdn.net/qq_26420489/article/details/53395472

     http://www.mamicode.com/info-detail-514466.html