DES的加密与解密(C语言实现)——大三密码学实验

目录

DES的描述

Feistel体制

密钥扩展函数

F函数

总流程

代码

get函数的构建

yihuo函数的构建

fuck函数的构建

left_move函数的构建

exchange函数的构建

erzhuanshi函数的构建

shizhuaner函数的构建

s_box函数的构建

主函数的构建

总函数

运行结果示例

DES的描述

DES：16轮，Feistel型结构

明文长度：64比特

密钥长度：64比特。实际使用56比特，另8位用作奇偶校验

密文长度：64比特

DES算法用Feistel体制作为框架进行设计，通过实现F函数和密钥扩展函数，并对Feistel进行初始置换和逆初始置换形成DES算法。

Feistel体制

即上一轮的R是下一轮的L，上一轮的R与那一轮对应的key经过F函数再与上一轮的L异或即是下一轮的R

密钥扩展函数

64比特密钥经过PC-1表进行置换，生成56比特密钥

然后把密钥分为两部分，左边28比特为C1，右边28比特为D1

接下来就是密钥扩展算法单轮结构

根据加密的轮数来确定Ci和Di左移几个比特

经过移位后再结合成56比特的密钥，再经过PC-2表置换，就生成对应轮的密钥

但是在下一轮时，使用的Ci和Di是上一轮的，而不是经过PC-2表生成的56比特密钥再平分的两个28比特密钥

至此经过16轮，所有密钥都已经生成

F函数

右半部分明文R经过E扩展，从32变为48位，再与对应的密钥异或，再经过S盒置换，生成32比特的密钥加，最会经过P置换就是F函数的最后输出。

难点在于S盒置换，S盒共8个表，每个表都是4*16的结构，每个S盒输入为6比特，输出为4比特，盒Si的输入为输入的分组的第 6i-5 到 6i 比特，盒Si的输入的第一位和最后一位组成一个2比特的二进制数来选择该盒的行，S盒输入的中间4位构成一个4比特的二进制数来选择该盒的列。

总流程

64比特密钥经过密钥扩展算法生成16轮密钥

明文先进行IP置换，再进行16轮迭代，再将最后生成的左密文与右密文对换顺序，结合后经过置换，即逆初始置换，就能够生成最后的64比特密文

代码

get函数的构建

int get(int r) //得到第r轮的移位数 {int i;if (r == 1 || r == 2 || r == 9 || r == 16) {i = 1;}else {i = 2;}return i;}

根据要进行迭代的轮数得到密钥需要左移的比特位数

yihuo函数的构建

void yihuo(int* a, int* b, int num)//异或 {int i;for (i = 0; i < num; i++){if (a[i] == b[i]) {//相同为0 a[i] = 0;}else {//不同为1 a[i] = 1;}}}

相同为0，不同为1，num为两个参数数组的大小

fuck函数的构建

void fuck(int a[64], int b[64], int n) {for (int i = 0; i < n; i++) {a[i] = b[i];}}

fuck函数人不如其名，其实只是把一个数组赋值给另一个数组

left_move函数的构建

void left_move(int s[28], int s1[28], int n) //左移{int i, t, temp;fuck(s, s1, 28);for (i = 0; i < n; i++) {temp = s[0];for (t = 0; t < 27; t++) {s[t] = s[t + 1];}s[27] = temp;//原先的左半部分第一位赋给最后一位 }}

即左移n位，先把数组S1赋值给S，防止后续对S造成更改

exchange函数的构建

void exchange(int* a, int* b, int* biao, int n)//置换 {int i, loc;for (i = 0; i < n; i++)//输入的第biao[i]位是输出的第i位 {loc = biao[i];b[i] = a[loc - 1];}return;}

即置换函数，输出的第i位等于 输入的（第i位对应的表的位数）的位数

erzhuanshi函数的构建

void erzhuanshi(int* a,unsigned char* b, int n)// a是二进制数组，b是存放十六进制的数组，n是二进制数组的大小{int i, j;n = n / 8;for (i = 0; i < n; i++){j = 128 * a[8 * i] + 64 * a[8 * i + 1] + 32 * a[8 * i + 2] + 16 * a[8 * i + 3] + 8 * a[8 * i + 4] + 4 * a[8 * i + 5] + 2 * a[8 * i + 6] + 1 * a[8 * i + 7];//先转换为十进制 b[i] = (char)j;//转换为char型字符 }}

即把二进制数组转化为十进制数组

shizhuaner函数的构建

void shizhuaner(int* a, int x, int i, int n)// a是存放二进制的数组，x是需要进行转换的十进制数，i是第i个十进制数，n是数组大小{int j; n = n / 8; j = n - 1;do {a[i * n + j] = x % 2;//x的2进制最后一位，0or1 x = x / 2;//右移 j--;} while (x != 0);while (j >= 0)//如果右移后出现000....的情况 {a[i * n + j] = 0;j--;}return;}

即把十进制数组转化为二进制数组

s_box函数的构建

void s_box(int a[32], int b[48]) //S盒{int i, r, c, s;int s1[4][16] = { { 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7 },{ 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8 },{ 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0 },{ 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13 } },s2[4][16] = { { 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10 },{ 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5 },{ 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15 },{ 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 } },s3[4][16] = { { 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8 },{ 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1 },{ 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7 },{ 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 } },s4[4][16] = { { 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15 },{ 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9 },{ 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 3 },{ 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 } },s5[4][16] = { { 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9 },{ 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6 },{ 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14 },{ 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 } },s6[4][16] = { { 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11 },{ 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8 },{ 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6 },{ 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 } },s7[4][16] = { { 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1 },{ 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6 },{ 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2 },{ 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12 } },s8[4][16] = { { 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7 },{ 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2 },{ 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8 },{ 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 } };for (i = 0; i < 8; i++){r = 2 * b[6 * i] + b[6 * i + 5];//第一位和最后一位构建行c = 8 * b[6 * i + 1] + 4 * b[6 * i + 2] + 2 * b[6 * i + 3] + b[6 * i + 4];//中间四位构建列 switch (i) //选择盒子 {case 0:s = s1[r][c]; break;case 1:s = s2[r][c]; break;case 2:s = s3[r][c]; break;case 3:s = s4[r][c]; break;case 4:s = s5[r][c]; break;case 5:s = s6[r][c]; break;case 6:s = s7[r][c]; break;case 7:s = s8[r][c]; break;}shizhuaner(a, s, i, 32); //转化为二进制 }}

上面已经做过说明

主函数的构建

intmain(){unsigned char a[8];//明文unsigned char b[8];//密钥inte[48] = { 32, 1, 2, 3, 4, 5,4, 5, 6, 7, 8, 9,8, 9, 10, 11, 12, 13,12, 13, 14, 15, 16, 17,16, 17, 18, 19, 20, 21,20, 21, 22, 23, 24, 25,24, 25, 26, 27, 28, 29,28, 29, 30, 31, 32, 1 };//E盒 intp[32] = { 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25 }; //P盒 int m_a[64] = { 0 };int m_b[64];//IP置换前后的明文 int s_a[64] = { 0 };int s_b[56];//置换1前后的二进制密钥 int r;//轮数int miwen[8] = { 0 }; //最终密文 int i, j = 0;int key_l[17][28];//16轮密钥 int key_r[17][28];int key_2[17][56];int zhihuan1[56] = { 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36, 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4 };//置换1 int IP[64] = { 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7 };//IP置换 int IP_1[64] = { 40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25 };//IP_1置换cout<<"* -------------- - DES加密-------------- *"<<endl<<endl;printf("请输入需要加密的明文:\n");//将明文转化为2进制for (i=0;i>a[i];shizhuaner(m_a,(int)a[i],i,64);}cout<<endl<<"请输入加密的密钥:"<<endl;//将密钥转为2进制for (i=0;i>b[i];shizhuaner(s_a,(int)b[i],i,64);}exchange(m_a, m_b, IP, 64); //明文进行初始置换 int min_l[17][32];int min_r[17][32];for (i = 0; i < 32; i++)//明文第0轮的左半部分 min_l[0][i] = m_b[i];for (i = 32; i < 64; i++)//明文的右半部分 min_r[0][i - 32] = m_b[i];exchange(s_a, s_b, zhihuan1, 56);//密钥进行PC-1置换int run = 1;for (int i = 0; i < 28; i++) {key_l[0][i] = s_b[i];key_r[0][i] = s_b[i + 28];}int n;for (r = 1; r <= 16; r++) {n = get(r);left_move(key_l[run], key_l[run - 1], n);left_move(key_r[run], key_r[run - 1], n);run++;}//结合 for (r = 1; r <= 16; r++) {for (i = 0; i < 28; i++) {key_2[r][i] = key_l[r][i];key_2[r][i + 28] = key_r[r][i];}}//pc-2置换int key_3[17][48];intzhihuan2[48] = { 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32 };//置换2for (r = 1; r <= 16; r++) {exchange(key_2[r], key_3[r], zhihuan2, 48);}//真正的16轮密钥到此生成 int temp6[48], temp1[32];for (int r = 1; r <= 16; r++) {fuck(min_l[r], min_r[r - 1], 32);//左半部分等于上一轮右半部分 exchange(min_r[r - 1], temp6, e, 48);//E置换yihuo(temp6, key_3[r], 48);//准备S盒置换 s_box(temp1, temp6);//s盒替换完毕 exchange(temp1, temp6, p, 32);//P置换 yihuo(temp6, min_l[r - 1], 32);fuck(min_r[r], temp6, 32);cout << "第" << r << "轮加密后的密文为" << endl;for (i = 0; i < 32; i++) {cout << min_l[r][i];}for (i = 0; i < 32; i++) {cout << min_r[r][i];}cout << endl;}int plus1[64] = { 0 };int plus2[64] = { 0 };for (i = 0; i < 32; i++) {plus1[i] = min_r[16][i];plus1[i + 32] = min_l[16][i];}unsigned char plus3[8];exchange(plus1, plus2, IP_1, 64);erzhuanshi(plus2, plus3, 64);cout << "最终密文为" << endl;for (i = 0; i < 8; i++) {cout << plus3[i];}//开始解密exchange(plus2, plus1, IP, 64);//IP_1置换 for (i = 0; i < 32; i++) {min_l[16][i] = plus1[i + 32];min_r[16][i] = plus1[i];}cout <= 1; r--) {fuck(min_r[r - 1], min_l[r], 32);//这一轮的左等于上一轮的右 exchange(min_r[r - 1], plus1, e, 48);//E扩展 yihuo(plus1, key_3[r], 48);//与密钥异或s_box(plus2, plus1);//S盒置换exchange(plus2, plus1, p, 32);//p盒置换fuck(min_l[r - 1], plus1, 32);yihuo(min_l[r - 1], min_r[r], 32);//异或 cout << "第" << 17 - r << "轮解密后的密文为" << endl;for (i = 0; i < 32; i++) {cout << min_l[r - 1][i];}for (i = 0; i < 32; i++) {cout << min_r[r - 1][i];}cout << endl;}for (i = 0; i < 32; i++) {plus1[i + 32] = min_r[0][i];plus1[i] = min_l[0][i];}exchange(plus1, plus2, IP_1, 64);cout << "解密后的密文为" << endl;int min_re[64];unsigned char min_plus[16];erzhuanshi(plus2, min_plus, 64);for (i = 0; i < 8; i++) {cout << min_plus[i];}cout << endl;fuck(min_re, plus2, 64);int flag = 0;for (i = 0; i < 64; i++) {if (m_a[i] != min_re[i]) {flag = 1;break;}}if (flag == 0) {cout << "解密成功";}else {cout << "解密失败";}}

没什么好解释的，就是跟着16轮迭代来呗，里面也加了注释

所谓解密就是加密的逆过程，大家都是大佬，我就不做过多解释

此外太冷了，写不下去了

总函数

#include #include using namespace std;int get(int r) //得到第r轮的移位数 {int i;if (r == 1 || r == 2 || r == 9 || r == 16) {i = 1;}else {i = 2;}return i;}void yihuo(int* a, int* b, int num)//异或 {int i;for (i = 0; i < num; i++){if (a[i] == b[i]) {//相同为0 a[i] = 0;}else {//不同为1 a[i] = 1;}}}void fuck(int a[64], int b[64], int n) {for (int i = 0; i < n; i++) {a[i] = b[i];}}void left_move(int s[28], int s1[28], int n) //左移{int i, t, temp;fuck(s, s1, 28);for (i = 0; i < n; i++) {temp = s[0];for (t = 0; t < 27; t++) {s[t] = s[t + 1];}s[27] = temp;//原先的左半部分第一位赋给最后一位 }}void exchange(int* a, int* b, int* biao, int n)//置换 {int i, loc;for (i = 0; i < n; i++)//输入的第biao[i]位是输出的第i位 {loc = biao[i];b[i] = a[loc - 1];}return;}void erzhuanshi(int* a,unsigned char* b, int n)// a是二进制数组，b是存放十六进制的数组，n是二进制数组的大小{int i, j;n = n / 8;for (i = 0; i = 0)//如果右移后出现000....的情况 {a[i * n + j] = 0;j--;}return;}void s_box(int a[32], int b[48]) //S盒{int i, r, c, s;int s1[4][16] = { { 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7 },{ 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8 },{ 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0 },{ 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13 } },s2[4][16] = { { 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10 },{ 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5 },{ 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15 },{ 13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 } },s3[4][16] = { { 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8 },{ 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1 },{ 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7 },{ 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 } },s4[4][16] = { { 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15 },{ 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9 },{ 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 3 },{ 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 } },s5[4][16] = { { 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9 },{ 14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6 },{ 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14 },{ 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 } },s6[4][16] = { { 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11 },{ 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8 },{ 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6 },{ 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 } },s7[4][16] = { { 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1 },{ 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6 },{ 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2 },{ 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12 } },s8[4][16] = { { 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7 },{ 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2 },{ 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8 },{ 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 } };for (i = 0; i < 8; i++){r = 2 * b[6 * i] + b[6 * i + 5];//第一位和最后一位构建行c = 8 * b[6 * i + 1] + 4 * b[6 * i + 2] + 2 * b[6 * i + 3] + b[6 * i + 4];//中间四位构建列 switch (i) //选择盒子 {case 0:s = s1[r][c]; break;case 1:s = s2[r][c]; break;case 2:s = s3[r][c]; break;case 3:s = s4[r][c]; break;case 4:s = s5[r][c]; break;case 5:s = s6[r][c]; break;case 6:s = s7[r][c]; break;case 7:s = s8[r][c]; break;}shizhuaner(a, s, i, 32); //转化为二进制 }}intmain(){unsigned char a[8];//明文unsigned char b[8];//密钥inte[48] = { 32, 1, 2, 3, 4, 5,4, 5, 6, 7, 8, 9,8, 9, 10, 11, 12, 13,12, 13, 14, 15, 16, 17,16, 17, 18, 19, 20, 21,20, 21, 22, 23, 24, 25,24, 25, 26, 27, 28, 29,28, 29, 30, 31, 32, 1 };//E盒 intp[32] = { 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25 }; //P盒 int m_a[64] = { 0 };int m_b[64];//IP置换前后的明文 int s_a[64] = { 0 };int s_b[56];//置换1前后的二进制密钥 int r;//轮数int miwen[8] = { 0 }; //最终密文 int i, j = 0;int key_l[17][28];//16轮密钥 int key_r[17][28];int key_2[17][56];int zhihuan1[56] = { 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36, 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4 };//置换1 int IP[64] = { 58, 50, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7 };//IP置换 int IP_1[64] = { 40, 8, 48, 16, 56, 24, 64, 32, 39, 7, 47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25 };//IP_1置换cout<<"* -------------- - DES加密-------------- *"<<endl<<endl;printf("请输入需要加密的明文:\n");//将明文转化为2进制for (i=0;i>a[i];shizhuaner(m_a,(int)a[i],i,64);}cout<<endl<<"请输入加密的密钥:"<<endl;//将密钥转为2进制for (i=0;i>b[i];shizhuaner(s_a,(int)b[i],i,64);}exchange(m_a, m_b, IP, 64); //明文进行初始置换 int min_l[17][32];int min_r[17][32];for (i = 0; i < 32; i++)//明文第0轮的左半部分 min_l[0][i] = m_b[i];for (i = 32; i < 64; i++)//明文的右半部分 min_r[0][i - 32] = m_b[i];exchange(s_a, s_b, zhihuan1, 56);//密钥进行PC-1置换int run = 1;for (int i = 0; i < 28; i++) {key_l[0][i] = s_b[i];key_r[0][i] = s_b[i + 28];}int n;for (r = 1; r <= 16; r++) {n = get(r);left_move(key_l[run], key_l[run - 1], n);left_move(key_r[run], key_r[run - 1], n);run++;}//结合 for (r = 1; r <= 16; r++) {for (i = 0; i < 28; i++) {key_2[r][i] = key_l[r][i];key_2[r][i + 28] = key_r[r][i];}}//pc-2置换int key_3[17][48];intzhihuan2[48] = { 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 52, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32 };//置换2for (r = 1; r <= 16; r++) {exchange(key_2[r], key_3[r], zhihuan2, 48);}//真正的16轮密钥到此生成 int temp6[48], temp1[32];for (int r = 1; r <= 16; r++) {fuck(min_l[r], min_r[r - 1], 32);//左半部分等于上一轮右半部分 exchange(min_r[r - 1], temp6, e, 48);//E置换yihuo(temp6, key_3[r], 48);//准备S盒置换 s_box(temp1, temp6);//s盒替换完毕 exchange(temp1, temp6, p, 32);//P置换 yihuo(temp6, min_l[r - 1], 32);fuck(min_r[r], temp6, 32);cout << "第" << r << "轮加密后的密文为" << endl;for (i = 0; i < 32; i++) {cout << min_l[r][i];}for (i = 0; i < 32; i++) {cout << min_r[r][i];}cout << endl;}int plus1[64] = { 0 };int plus2[64] = { 0 };for (i = 0; i < 32; i++) {plus1[i] = min_r[16][i];plus1[i + 32] = min_l[16][i];}unsigned char plus3[8];exchange(plus1, plus2, IP_1, 64);erzhuanshi(plus2, plus3, 64);cout << "最终密文为" << endl;for (i = 0; i < 8; i++) {cout << plus3[i];}//开始解密exchange(plus2, plus1, IP, 64);//IP_1置换 for (i = 0; i < 32; i++) {min_l[16][i] = plus1[i + 32];min_r[16][i] = plus1[i];}cout <= 1; r--) {fuck(min_r[r - 1], min_l[r], 32);//这一轮的左等于上一轮的右 exchange(min_r[r - 1], plus1, e, 48);//E扩展 yihuo(plus1, key_3[r], 48);//与密钥异或s_box(plus2, plus1);//S盒置换exchange(plus2, plus1, p, 32);//p盒置换fuck(min_l[r - 1], plus1, 32);yihuo(min_l[r - 1], min_r[r], 32);//异或 cout << "第" << 17 - r << "轮解密后的密文为" << endl;for (i = 0; i < 32; i++) {cout << min_l[r - 1][i];}for (i = 0; i < 32; i++) {cout << min_r[r - 1][i];}cout << endl;}for (i = 0; i < 32; i++) {plus1[i + 32] = min_r[0][i];plus1[i] = min_l[0][i];}exchange(plus1, plus2, IP_1, 64);cout << "解密后的密文为" << endl;int min_re[64];unsigned char min_plus[16];erzhuanshi(plus2, min_plus, 64);for (i = 0; i < 8; i++) {cout << min_plus[i];}cout << endl;fuck(min_re, plus2, 64);int flag = 0;for (i = 0; i < 64; i++) {if (m_a[i] != min_re[i]) {flag = 1;break;}}if (flag == 0) {cout << "解密成功";}else {cout << "解密失败";}}

运行结果示例