最近要学习AES的算法实现过程，在网上找了很多AES加解密的代码，发现大多数都是调用API的，看不到具体实现过程，后来在CSDN上找了一下AES的源码(免积分的)，但是没有注释，有注释的都需要积分，所以我自己理了一遍，顺便把源码也分享给大家。
在分析代码的过程中发现下载的代码是按照行排序的，但是课本中讲的是按照列排序，所以后面我自己又把代码写成列排序的。下面解释一下什么是** 行 列 **排序。
按照列排序
- 输入序列为：x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15 x16
- 矩阵排列为：
- x1 x5 x9 x13
- x2 x6 x10 x14
- x3 x7 x11 x15
- x4 x8 x12 x16
按照行排序
- 输入序列为：x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15 x16
- 矩阵排列为：
- x1 x2 x3 x4
- x5 x6 x7 x8
- x9 x10 x11 x12
- x13 x14 x15 x16
最后给出实现代码 首先是列实现，然后是行实现。
/**
* AES过程演示 这是按照课程中AES讲解的顺序做的 也就是按照 列 排序
* 输入序列为：x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15 x16
* 矩阵排列为：
* x1 x5 x9 x13
* x2 x6 x10 x14
* x3 x7 x11 x15
* x4 x8 x12 x16
*
* @author Bloomeet
* @time 2018/9/23 19:55
*/
public class AESclass_column {
static int Nr = 10;//轮数
static int key[] = {0x00, 0x71, 0xDA, 0x60, 0x01, 0x01, 0x79, 0x15, 0x20,
0x98, 0x17, 0x35, 0x01, 0xAE, 0x14, 0x94};//16进制密钥
static int text[] = {0x00, 0x01, 0xda, 0x86, 0x01, 0xA1, 0x78, 0x15, 0x00,
0x98, 0x17, 0x35, 0x01, 0xAF, 0x34, 0x66};//16进制明文
// static int key[] = {0x00, 0x01, 0x20, 0x01, 0x71, 0x01, 0x98, 0xAE, 0xDA,
// 0x79, 0x17, 0x14, 0x60, 0x15, 0x35, 0x94};//16进制密钥
//
// static int text[] = {0x00, 0x01, 0x00, 0x01, 0x01, 0xA1, 0x98, 0xAF, 0xDA,
// 0x78, 0x17, 0x34, 0x86, 0x15, 0x35, 0x66};//16进制明文
static int 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,};//S盒表
static int RCon[];//密钥的常量数组
static int word[][];//轮密钥扩展后的数组，大小为 word[44][4]
public static void main(String[] args) {
keyExpansion();//密钥
int i, r = 0;
text = addRoundKey(text, 0);//初始轮密钥加
r++;
for (; r <= Nr; r++) { // 迭代10轮
for (i = 0; i < 16; i++) {
text[i] = subByte(text[i]);// 字节替代
}
text = shiftRows(text); // 行移位
if (r != 10) {// 注意：AES加密最后一轮没有列混合
text = mixColumn(text);// 列混合
}
text = addRoundKey(text, r);// 轮密钥加
}
//输出加密结果
for (i = 0; i < 16; i++) {
System.out.print(Integer.toHexString(text[i]) + " ");
if (i % 4 == 3) {
System.out.println();
}
}
}
/**
* 密钥数组扩展
*/
static void keyExpansion() {
RCon = new int[10];//轮常量为固定值
RCon[0] = 0x01;
RCon[1] = 0x02;
RCon[2] = 0x04;
RCon[3] = 0x08;
RCon[4] = 0x10;
RCon[5] = 0x20;
RCon[6] = 0x40;
RCon[7] = 0x80;
RCon[8] = 0x1B;
RCon[9] = 0x36;
word = new int[44][4];//44组轮密钥
int i, j;
int temp[];
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
word[i][j] = key[j * 4 + i]; //把初始密钥放入数组
}
}
/*通过密钥计算规则计算余下数组
*
*1.如果i不是4的倍数，那么第i列由如下等式确定：
*W[i]=W[i-4]⨁W[i-1]
*2.如果i是4的倍数，那么第i列由如下等式确定：
*W[i]=W[i-4]⨁T(W[i-1])
*其中，T是一个有点复杂的函数。函数T由3部分组成：字循环(每次循环一位)、字节代换（s盒）和轮常量异或。
*/
for (i = 4; i < 44; i++) {
temp = word[i - 1];//看作W[i-1]
if (i % 4 == 0) { //i为4的倍数 进入函数运算 W[i-1]=T(W[i-1])
temp = subWord(rotWord(temp));
temp[0] = temp[0] ^ RCon[i / 4 - 1];
}
for (j = 0; j < 4; j++) {
word[i][j] = word[i - 4][j] ^ temp[j];//相当于W[i]=W[i-4]⨁W[i-1]
}
}
}
//密钥扩展中的移位
static int[] rotWord(int[] word) {
int[] rot = new int[4];
int i;
for (i = 0; i < 4; i++) {
rot[i] = word[(i + 1) % 4];
}
return rot;
}
//密钥扩展中的4个字节的代换（4个字节为一组） 例如 A2 BE C4 D5
static int[] subWord(int[] word) {
int sub[] = new int[4];
int i;
for (i = 0; i < 4; i++) {
sub[i] = subByte(word[i]);
}
return sub;
}
//S盒的单个字节代换 例如 AE
static int subByte(int w) {
int x = w / 16;
int y = w % 16;
return sbox[x * 16 + y];
}
//轮密钥加
static int[] addRoundKey(int[] text, int round) {
int[] add = new int[16];
int i, j;
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
//System.out.print(Integer.toHexString(word[4 * round + i][j]) + ",");//第round轮的轮密钥
add[4 * j + i] = text[4 * j + i] ^ word[4 * round + i][j]; //逐比特异或
}
//System.out.println();
}
return add;
}
//行移位（循环移位）规则：第0行移0位 ..... 第3行移3位
static int[] shiftRows(int[] text) {
int[] shift = new int[16];
int i, j;
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
if ((4 * i + j + i) == 8 || (4 * i + j + i) == 12 || (4 * i + j + i) == 13 || (4 * i + j + i) > 15) {
shift[4 * i + j] = text[(4 * i + j + i) - 4];
} else {
shift[4 * i + j] = text[4 * i + j + i];
}
}
}
return shift;
}
//列混合
static int[] mixColumn(int[] text) {
int[] mix = new int[16];
int[] mass = {2, 3, 1, 1,
1, 2, 3, 1,
1, 1, 2, 3,
3, 1, 1, 2
};
int i, j, u;
for (i = 0; i < 16; i++) {
u = 0;
for (j = 0; j < 4; j++) {
u = u ^ fieldMulit(mass[(i / 4) * 4 + j], text[4 * j + i % 4]);
}
mix[i] = u;
}
return mix;
}
static int fieldMulit(int x, int y) {
String xString = Integer.toBinaryString(x);
int i, j, mul = 0, tem = y;
for (i = 0; i < xString.length(); i++) {
if (xString.charAt(i) == '1') {
for (j = 1; j < xString.length() - i; j++) {
tem = tem << 1;
if (tem > 255) {
tem = tem % 256;
tem = tem ^ 0x1b;
}
}
mul = mul ^ tem;
tem = y;
}
}
return mul;
}
}
/**
* AES过程演示 按照 行 排列 与课本中讲解的排列顺序相反
* 输入序列为：x1 x2 x3 x4 x5 x6 x7 x8 x9 x10 x11 x12 x13 x14 x15 x16
* 矩阵排列为：
* x1 x2 x3 x4
* x5 x6 x7 x8
* x9 x10 x11 x12
* x13 x14 x15 x16
*
* @author Bloomeet
* @time 2018/9/23 19:55
*/
public class AESclass_Line {
static int Nr = 10;//轮数
static int key[] = {0x00, 0x01, 0x20, 0x01, 0x71, 0x01, 0x98, 0xAE, 0xDA,
0x79, 0x17, 0x14, 0x60, 0x15, 0x35, 0x94};//16进制密钥
static int text[] = {0x00, 0x01, 0x00, 0x01, 0x01, 0xA1, 0x98, 0xAF, 0xDA,
0x78, 0x17, 0x34, 0x86, 0x15, 0x35, 0x66};//16进制明文
static int 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,};//S盒表
static int RCon[];//密钥的常量数组
static int word[][];//轮密钥扩展后的数组，大小为 word[44][4]
public static void main(String[] args) {
keyExpansion();//密钥
int i, r = 0;
text = addRoundKey(text, 0);//初始轮密钥加
r++;
for (; r <= Nr; r++) { // 迭代10轮
for (i = 0; i < 16; i++) {
text[i] = subByte(text[i]);// 字节替代
}
text = shiftRows(text); // 行移位
if (r != 10) {// 注意：AES加密最后一轮没有列混合
text = mixColumn(text);// 列混合
}
text = addRoundKey(text, r);// 轮密钥加
}
//输出加密结果
for (i = 0; i < 16; i++) {
System.out.print(Integer.toHexString(text[i]) + " ");
if (i % 4 == 3) {
System.out.println();
}
}
}
/**
* 密钥数组扩展
*/
static void keyExpansion() {
RCon = new int[10];//轮常量为固定值
RCon[0] = 0x01;
RCon[1] = 0x02;
RCon[2] = 0x04;
RCon[3] = 0x08;
RCon[4] = 0x10;
RCon[5] = 0x20;
RCon[6] = 0x40;
RCon[7] = 0x80;
RCon[8] = 0x1B;
RCon[9] = 0x36;
word = new int[44][4];//44组轮密钥
int i, j;
int temp[];
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
word[i][j] = key[i * 4 + j]; //把初始密钥放入数组
}
}
/*通过密钥计算规则计算余下数组
*
*1.如果i不是4的倍数，那么第i列由如下等式确定：
*W[i]=W[i-4]⨁W[i-1]
*2.如果i是4的倍数，那么第i列由如下等式确定：
*W[i]=W[i-4]⨁T(W[i-1])
*其中，T是一个有点复杂的函数。函数T由3部分组成：字循环(每次循环一位)、字节代换（s盒）和轮常量异或。
*/
for (i = 4; i < 44; i++) {
temp = word[i - 1];//看作W[i-1]
if (i % 4 == 0) { //i为4的倍数 进入函数运算 W[i-1]=T(W[i-1])
temp = subWord(rotWord(temp));
temp[0] = temp[0] ^ RCon[i / 4 - 1];
}
for (j = 0; j < 4; j++) {
word[i][j] = word[i - 4][j] ^ temp[j];//相当于W[i]=W[i-4]⨁W[i-1]
}
}
}
//密钥扩展中的移位
static int[] rotWord(int[] word) {
int[] rot = new int[4];
int i;
for (i = 0; i < 4; i++) {
rot[i] = word[(i + 1) % 4];
}
return rot;
}
//密钥扩展中的4个字节的代换（4个字节为一组） 例如 A2 BE C4 D5
static int[] subWord(int[] word) {
int sub[] = new int[4];
int i;
for (i = 0; i < 4; i++) {
sub[i] = subByte(word[i]);
}
return sub;
}
//S盒的单个字节代换 例如 AE
static int subByte(int w) {
int x = w / 16;
int y = w % 16;
return sbox[x * 16 + y];
}
//轮密钥加
static int[] addRoundKey(int[] text, int round) {
int[] add = new int[16];
int i, j;
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
//System.out.print(Integer.toHexString(word[4 * round + i][j]) + ",");//第round轮的轮密钥
add[4 * i + j] = text[4 * i + j] ^ word[4 * round + i][j]; //逐比特异或
}
}
return add;
}
//行移位（循环移位）规则：第0行移0位 ..... 第3行移3位
static int[] shiftRows(int[] text) {
int[] shift = new int[16];
int i, j;
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++) {
shift[4 * i + j] = text[4 * ((i + j) % 4) + j];
}
}
return shift;
}
//列混合
static int[] mixColumn(int[] text) {
int[] mix = new int[16];
int[] mass = {2, 3, 1, 1};
int i, j, u;
for (i = 0; i < 16; i++) {
u = 0;
for (j = 0; j < 4; j++) {
u = u ^ fieldMulit(text[(i / 4) * 4 + j], mass[(4 - i % 4 + j) % 4]);
}
mix[i] = u;
}
return mix;
}
static int fieldMulit(int x, int y) {
String xString = Integer.toBinaryString(x);
int i, j, mul = 0, tem = y;
for (i = 0; i < xString.length(); i++) {
if (xString.charAt(i) == '1') {
for (j = 1; j < xString.length() - i; j++) {
tem = tem << 1;
if (tem > 255) {
tem = tem % 256;
tem = tem ^ 0x1b;
}
}
mul = mul ^ tem;
tem = y;
}
}
return mul;
}
}