之前工作项目要求对文件数据要进行解密处理，而且必须是AES128算法，然后自己去找资料熟悉该算法和流程，以及具体怎么实现的。由于只能对16字节进行处理，所以我对文件进行拆分，将大文件拆为多个小文件，利用多线程去处理文件，加快算法处理。最后功能还是比较耗时，暂时没想到合适的解决方法，
注意：该算法在32位操作系统和64位操作系统处理时间有快慢。我这边也有一个验证解密加密是否正确的小插件。需要可以私信。
AES128加密解密的主要操作算法代码
Aes128加密解密，每轮只能对16字节进行处理；
16字节密钥也是最重要的；
加密流程：轮密钥加、字节代替、行移位、列混淆；
解密流程：轮密钥加、逆向字节代替、逆向行移位、逆向列混淆；
流程进行10轮；
16字节密钥还要进行扩展密钥处理；
具体原理操作流程后续补充。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "aes.h"
/**
* S盒
*/
static const int S[16][16] = { 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 };
/**
* 逆S盒
*/
static const int S2[16][16] = { 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 };
/**
* 获取整形数据的低8位的左4个位
*/
static int getLeft4Bit(int num) {
int left = num & 0x000000f0;
return left >> 4;
}
/**
* 获取整形数据的低8位的右4个位
*/
static int getRight4Bit(int num) {
return num & 0x0000000f;
}
/**
* 根据索引，从S盒中获得元素
*/
static int getNumFromSBox(int index) {
int row = getLeft4Bit(index);
int col = getRight4Bit(index);
return S[row][col];
}
/**
* 把一个字符转变成整型
*/
static int getIntFromChar(char c) {
int result = (int)c;
return result & 0x000000ff;
}
/**
* 把16个字符转变成4X4的数组，
* 该矩阵中字节的排列顺序为从上到下，
* 从左到右依次排列。
*/
static void convertToIntArray(char* str, int pa[4][4]) {
int k = 0;
int i, j;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++) {
pa[j][i] = getIntFromChar(str[k]);
k++;
}
}
/**
* 打印4X4的数组
*/
static void printArray(int a[4][4]) {
int i, j;
for (i = 0; i < 4; i++) {
for (j = 0; j < 4; j++)
printf("a[%d][%d] = 0x%x ", i, j, a[i][j]);
printf("\n");
}
printf("\n");
}
/**
* 打印字符串的ASSCI，
* 以十六进制显示。
*/
static void printASSCI(char* str, int len) {
int i;
for (i = 0; i < len; i++)
printf("0x%x ", getIntFromChar(str[i]));
printf("\n");
}
/**
* 把连续的4个字符合并成一个4字节的整型
*/
static int getWordFromStr(char* str) {
int one, two, three, four;
one = getIntFromChar(str[0]);
one = one << 24;
two = getIntFromChar(str[1]);
two = two << 16;
three = getIntFromChar(str[2]);
three = three << 8;
four = getIntFromChar(str[3]);
return one | two | three | four;
}
/**
* 把一个4字节的数的第一、二、三、四个字节取出，
* 入进一个4个元素的整型数组里面。
*/
static void splitIntToArray(int num, int array[4]) {
int one, two, three;
one = num >> 24;
array[0] = one & 0x000000ff;
two = num >> 16;
array[1] = two & 0x000000ff;
three = num >> 8;
array[2] = three & 0x000000ff;
array[3] = num & 0x000000ff;
}
/**
* 将数组中的元素循环左移step位
*/
static void leftLoop4int(int array[4], int step) {
int temp[4];
int i;
int index;
for (i = 0; i < 4; i++)
temp[i] = array[i];
index = step % 4 == 0 ? 0 : step % 4;
for (i = 0; i < 4; i++) {
array[i] = temp[index];
index++;
index = index % 4;
}
}
/**
* 把数组中的第一、二、三和四元素分别作为
* 4字节整型的第一、二、三和四字节，合并成一个4字节整型
*/
static int mergeArrayToInt(int array[4]) {
int one = array[0] << 24;
int two = array[1] << 16;
int three = array[2] << 8;
int four = array[3];
return one | two | three | four;
}
/**
* 常量轮值表
*/
static const int Rcon[10] = { 0x01000000, 0x02000000,
0x04000000, 0x08000000,
0x10000000, 0x20000000,
0x40000000, 0x80000000,
0x1b000000, 0x36000000 };
/**
* 密钥扩展中的T函数
*/
static int T(int num, int round) {
int numArray[4];
int i;
int result;
splitIntToArray(num, numArray);
leftLoop4int(numArray, 1);//字循环
//字节代换
for (i = 0; i < 4; i++)
numArray[i] = getNumFromSBox(numArray[i]);
result = mergeArrayToInt(numArray);
return result ^ Rcon[round];
}
//密钥对应的扩展数组
static int w[44];
/**
* 打印W数组
*/
static void printW() {
int i, j;
for (i = 0, j = 1; i < 44; i++, j++) {
printf("w[%d] = 0x%x ", i, w[i]);
if (j % 4 == 0)
printf("\n");
}
printf("\n");
}
/**
* 扩展密钥，结果是把w[44]中的每个元素初始化
*/
static void extendKey(char* key) {
int i, j;
for (i = 0; i < 4; i++)
w[i] = getWordFromStr(key + i * 4);
for (i = 4, j = 0; i < 44; i++) {
if (i % 4 == 0) {
w[i] = w[i - 4] ^ T(w[i - 1], j);
j++;//下一轮
}
else {
w[i] = w[i - 4] ^ w[i - 1];
}
}
}
/**
* 轮密钥加
*/
static void addRoundKey(int array[4][4], int round) {
int warray[4];
int i, j;
for (i = 0; i < 4; i++) {
splitIntToArray(w[round * 4 + i], warray);
for (j = 0; j < 4; j++) {
array[j][i] = array[j][i] ^ warray[j];
}
}
}
/**
* 字节代换
*/
static void subBytes(int array[4][4]) {
int i, j;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
array[i][j] = getNumFromSBox(array[i][j]);
}
/**
* 行移位
*/
static void shiftRows(int array[4][4]) {
int rowTwo[4], rowThree[4], rowFour[4];
int i;
for (i = 0; i < 4; i++) {
rowTwo[i] = array[1][i];
rowThree[i] = array[2][i];
rowFour[i] = array[3][i];
}
leftLoop4int(rowTwo, 1);
leftLoop4int(rowThree, 2);
leftLoop4int(rowFour, 3);
for (i = 0; i < 4; i++) {
array[1][i] = rowTwo[i];
array[2][i] = rowThree[i];
array[3][i] = rowFour[i];
}
}
/**
* 列混合要用到的矩阵
*/
static const int colM[4][4] = { 2, 3, 1, 1,
1, 2, 3, 1,
1, 1, 2, 3,
3, 1, 1, 2 };
static int GFMul2(int s) {
int result = s << 1;
int a7 = result & 0x00000100;
if (a7 != 0) {
result = result & 0x000000ff;
result = result ^ 0x1b;
}
return result;
}
static int GFMul3(int s) {
return GFMul2(s) ^ s;
}
static int GFMul4(int s) {
return GFMul2(GFMul2(s));
}
static int GFMul8(int s) {
return GFMul2(GFMul4(s));
}
static int GFMul9(int s) {
return GFMul8(s) ^ s;
}
static int GFMul11(int s) {
return GFMul9(s) ^ GFMul2(s);
}
static int GFMul12(int s) {
return GFMul8(s) ^ GFMul4(s);
}
static int GFMul13(int s) {
return GFMul12(s) ^ s;
}
static int GFMul14(int s) {
return GFMul12(s) ^ GFMul2(s);
}
/**
* GF上的二元运算
*/
static int GFMul(int n, int s) {
int result;
if (n == 1)
result = s;
else if (n == 2)
result = GFMul2(s);
else if (n == 3)
result = GFMul3(s);
else if (n == 0x9)
result = GFMul9(s);
else if (n == 0xb)//11
result = GFMul11(s);
else if (n == 0xd)//13
result = GFMul13(s);
else if (n == 0xe)//14
result = GFMul14(s);
return result;
}
/**
* 列混合
*/
static void mixColumns(int array[4][4]) {
int tempArray[4][4];
int i, j;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
tempArray[i][j] = array[i][j];
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++) {
array[i][j] = GFMul(colM[i][0], tempArray[0][j]) ^ GFMul(colM[i][1], tempArray[1][j])
^ GFMul(colM[i][2], tempArray[2][j]) ^ GFMul(colM[i][3], tempArray[3][j]);
}
}
/**
* 把4X4数组转回字符串
*/
static void convertArrayToStr(int array[4][4], char* str) {
int i, j;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
*str++ = (char)array[j][i];
}
/**
* 检查密钥长度
*/
static int checkKeyLen(int len) {
if (len == 16)
return 1;
else
return 0;
}
/**
* 参数 p: 明文的字符串数组。
* 参数 plen: 明文的长度。
* 参数 key: 密钥的字符串数组。
*/
void aes(char* p, int plen, char* key) {
int keylen = strlen(key);
int pArray[4][4];
int k, i;
if (plen == 0 || plen % 16 != 0) {
printf("明文字符长度必须为16的倍数！\n");
exit(0);
}
if (!checkKeyLen(keylen)) {
printf("密钥字符长度错误！长度必须为16。当前长度为%d\n", keylen);
exit(0);
}
extendKey(key);//扩展密钥
for (k = 0; k < plen; k += 16) {
convertToIntArray(p + k, pArray);
addRoundKey(pArray, 0);//一开始的轮密钥加
for (i = 1; i < 10; i++) {
subBytes(pArray);//字节代换
shiftRows(pArray);//行移位
mixColumns(pArray);//列混合
addRoundKey(pArray, i);
}
subBytes(pArray);//字节代换
shiftRows(pArray);//行移位
addRoundKey(pArray, 10);
convertArrayToStr(pArray, p + k);
}
}
/**
* 根据索引从逆S盒中获取值
*/
static int getNumFromS1Box(int index) {
int row = getLeft4Bit(index);
int col = getRight4Bit(index);
return S2[row][col];
}
/**
* 逆字节变换
*/
static void deSubBytes(int array[4][4]) {
int i, j;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
array[i][j] = getNumFromS1Box(array[i][j]);
}
/**
* 把4个元素的数组循环右移step位
*/
static void rightLoop4int(int array[4], int step) {
int temp[4];
int i;
int index;
for (i = 0; i < 4; i++)
temp[i] = array[i];
index = step % 4 == 0 ? 0 : step % 4;
index = 3 - index;
for (i = 3; i >= 0; i--) {
array[i] = temp[index];
index--;
index = index == -1 ? 3 : index;
}
}
/**
* 逆行移位
*/
static void deShiftRows(int array[4][4]) {
int rowTwo[4], rowThree[4], rowFour[4];
int i;
for (i = 0; i < 4; i++) {
rowTwo[i] = array[1][i];
rowThree[i] = array[2][i];
rowFour[i] = array[3][i];
}
rightLoop4int(rowTwo, 1);
rightLoop4int(rowThree, 2);
rightLoop4int(rowFour, 3);
for (i = 0; i < 4; i++) {
array[1][i] = rowTwo[i];
array[2][i] = rowThree[i];
array[3][i] = rowFour[i];
}
}
/**
* 逆列混合用到的矩阵
*/
static const int deColM[4][4] = { 0xe, 0xb, 0xd, 0x9,
0x9, 0xe, 0xb, 0xd,
0xd, 0x9, 0xe, 0xb,
0xb, 0xd, 0x9, 0xe };
/**
* 逆列混合
*/
static void deMixColumns(int array[4][4]) {
int tempArray[4][4];
int i, j;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
tempArray[i][j] = array[i][j];
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++) {
array[i][j] = GFMul(deColM[i][0], tempArray[0][j]) ^ GFMul(deColM[i][1], tempArray[1][j])
^ GFMul(deColM[i][2], tempArray[2][j]) ^ GFMul(deColM[i][3], tempArray[3][j]);
}
}
/**
* 把两个4X4数组进行异或
*/
static void addRoundTowArray(int aArray[4][4], int bArray[4][4]) {
int i, j;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
aArray[i][j] = aArray[i][j] ^ bArray[i][j];
}
/**
* 从4个32位的密钥字中获得4X4数组，
* 用于进行逆列混合
*/
static void getArrayFrom4W(int i, int array[4][4]) {
int index, j;
int colOne[4], colTwo[4], colThree[4], colFour[4];
index = i * 4;
splitIntToArray(w[index], colOne);
splitIntToArray(w[index + 1], colTwo);
splitIntToArray(w[index + 2], colThree);
splitIntToArray(w[index + 3], colFour);
for (j = 0; j < 4; j++) {
array[j][0] = colOne[j];
array[j][1] = colTwo[j];
array[j][2] = colThree[j];
array[j][3] = colFour[j];
}
}
/**
* 参数 c: 密文的字符串数组。
* 参数 clen: 密文的长度。
* 参数 key: 密钥的字符串数组。
*/
void deAes(char* c, int clen, char* key) {
int cArray[4][4];
int keylen, k;
keylen = strlen(key);
if (clen == 0 || clen % 16 != 0) {
printf("密文字符长度必须为16的倍数！现在的长度为%d\n", clen);
exit(0);
}
if (!checkKeyLen(keylen)) {
printf("密钥字符长度错误！长度必须为16、24和32。当前长度为%d\n", keylen);
exit(0);
}
extendKey(key);//扩展密钥
for (k = 0; k < clen; k += 16) {
int i;
int wArray[4][4];
convertToIntArray(c + k, cArray);
addRoundKey(cArray, 10);
for (i = 9; i >= 1; i--) {
deSubBytes(cArray);
deShiftRows(cArray);
deMixColumns(cArray);
getArrayFrom4W(i, wArray);
deMixColumns(wArray);
addRoundTowArray(cArray, wArray);
}
deSubBytes(cArray);
deShiftRows(cArray);
addRoundKey(cArray, 0);
convertArrayToStr(cArray, c + k);
}
}
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