DES分组密码算法_加解密任意长度文件
参考来源：https://blog.csdn.net/lisonglisonglisong/article/details/41777413
- 调用DES分组密码源程序中的相关函数，设计一个文件加密器，可以加密任意长度的文件，并且密文文件可解密还原回原明文文件。
- DES分组密码算法流程：
（1）以下程序加密从桌面上的des_message.txt读入8个字符长度的明文，然后输出到桌面上的des_password.txt文件中，解密从后者输出到桌面上的des_p2m.txt文件中（由于加密后或解密失败后输出的字符为中文乱码，在Mac系统中无法正常打开，因此显示图标不一样）。
代码如下：/*提醒：代码很长*/
#include
#include
#include "memory.h"
#include "time.h"
#include "stdlib.h"
using namespace std;
#define PLAIN_FILE_OPEN_ERROR -1
#define CIPHER_FILE_OPEN_ERROR -2
#define OK 1
typedef char ElemType;
/* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** *//* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** */
/*初始置换IP*////第一步
int IP_Table[64] = { 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,
56,48,40,32,24,16,8,0,
58,50,42,34,26,18,10,2,
60,52,44,36,28,20,12,4,
62,54,46,38,30,22,14,6};
/*逆初始置换IP^-1*////最后一步
int IP_1_Table[64] = {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,
32,0,40,8,48,16,56,24};
/* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** *//* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** */
/* ***** ***** ***** ***** ***** 密码函数f所用到的表 ***** ***** ***** ***** ***** *//* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** */
/*选择运算E*///扩展置换表，将32位扩展位48位
int E_Table[48] = {31, 0, 1, 2, 3, 4,
3, 4, 5, 6, 7, 8,
7, 8, 9,10,11,12,
11,12,13,14,15,16,
15,16,17,18,19,20,
19,20,21,22,23,24,
23,24,25,26,27,28,
27,28,29,30,31, 0};
/*置换运算P*///P置换，将32位变成32位//S盒输出的8*4=32位的置换//f函数的输出
int P_Table[32] = {15,6,19,20,
28,11,27,16,
0,14,22,25,
4,17,30,9,
1,7,23,13,
31,26,2,8,
18,12,29,5,
21,10,3,24};
/*S盒*///8个S盒，均为4*16的置换表，将6位转换为4位//第1位和第6位作为行，中间四位作为列，对应的数作为4位二进制数输出
int S[8][4][16] =
{
/*S1*/
{{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*/
{{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*/
{{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*/
{{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, 4},
{3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14}},
/*S5*/
{{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*/
{{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, 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*/
{{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}}};
/* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** *//* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** */
/* ***** ***** ***** ***** ***** 生成密钥所用表 ***** ***** ***** ***** ***** *//* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** */
/*置换选择1*///密钥置换表，将64位密钥变成56位//去奇偶校验位
int PC_1[56] = {
56, 48, 40, 32, 24, 16, 8,
0, 57, 49, 41, 33, 25, 17,
9, 1, 58, 50, 42, 34, 26,
18, 10, 2, 59, 51, 43, 35,
62, 54, 46, 38, 30, 22, 14,
6, 61, 53, 45, 37, 29, 21,
13, 5, 60, 52, 44, 36, 28,
20, 12, 4, 27, 19, 11, 3};
/*置换选择2*///压缩置换，将56位密钥压缩成48位
int PC_2[48] = {
13, 16, 10, 23, 0, 4, 2, 27,
14, 5, 20, 9, 22, 18, 11, 3,
25, 7, 15, 6, 26, 19, 12, 1,
40, 51, 30, 36, 46, 54, 29, 39,
50, 44, 32, 46, 43, 48, 38, 55,
33, 52, 45, 41, 49, 35, 28, 31};
/*循环左移位数表*///每轮左移的位数
int MOVE_TIMES[16] = {1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1};
/* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** *//* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** */
/* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** *//* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** */
/*函数声明（共19个）*/
int ByteToBit(ElemType ch,ElemType bit[8]);
int BitToByte(ElemType bit[8],ElemType *ch);
int Char8ToBit64(ElemType ch[8],ElemType bit[64]);
int Bit64ToChar8(ElemType bit[64],ElemType ch[8]);
int DES_MakeSubKeys(ElemType key[64],ElemType subKeys[16][48]);
int DES_PC1_Transform(ElemType key[64], ElemType tempbts[56]);
int DES_PC2_Transform(ElemType key[56], ElemType tempbts[48]);
int DES_ROL(ElemType data[56], int time);
int DES_IP_Transform(ElemType data[64]);
int DES_IP_1_Transform(ElemType data[64]);
int DES_E_Transform(ElemType data[48]);
int DES_P_Transform(ElemType data[32]);
int DES_SBOX(ElemType data[48]);
int DES_XOR(ElemType R[48], ElemType L[48],int count);
int DES_Swap(ElemType left[32],ElemType right[32]);
int DES_EncryptBlock(ElemType plainBlock[8], ElemType subKeys[16][48], ElemType cipherBlock[8]);
int DES_DecryptBlock(ElemType cipherBlock[8], ElemType subKeys[16][48], ElemType plainBlock[8]);
int DES_Encrypt(char *plainFile, char *keyStr,char *cipherFile);
int DES_Decrypt(char *cipherFile, char *keyStr,char *plainFile);
/* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** *//* ***** ***** ***** ***** ***** ***** ***** ***** ***** ***** */
/*函数功能实现*/
/*字节转换成二进制*/
int ByteToBit(ElemType ch, ElemType bit[8]){
int cnt;
for(cnt = 0;cnt < 8; cnt++){
*(bit+cnt) = (ch>>cnt)&1;
}
return 0;
}//倒序的
/*二进制转换成字节*/
int BitToByte(ElemType bit[8],ElemType *ch){
int cnt;
for(cnt = 0;cnt < 8; cnt++){
*ch |= *(bit + cnt)<
}
return 0;
}
/*将长度为8的字符串转为二进制位串*/
int Char8ToBit64(ElemType ch[8],ElemType bit[64]){
int cnt;
for(cnt = 0; cnt < 8; cnt++){
ByteToBit(*(ch+cnt),bit+(cnt<<3));
}
return 0;
}
/*将二进制位串转为长度为8的字符串*/
int Bit64ToChar8(ElemType bit[64],ElemType ch[8]){
int cnt;
memset(ch,0,8); //void *memset( void *dest, int c, size_t count );
for(cnt = 0; cnt < 8; cnt++){
BitToByte(bit+(cnt<<3),ch+cnt);
}
return 0;
}
/*生成子密钥*/
int DES_MakeSubKeys(ElemType key[64],ElemType subKeys[16][48]){
ElemType temp[56];
int cnt;
DES_PC1_Transform(key,temp); /*PC1置换*/
for(cnt = 0; cnt < 16; cnt++){ /*16轮跌代，产生16个子密钥*/
DES_ROL(temp,MOVE_TIMES[cnt]); /*循环左移*/
DES_PC2_Transform(temp,subKeys[cnt]); /*PC2置换，产生子密钥*/
}
return 0;
}
/*置换选择1*////去奇偶校验位
int DES_PC1_Transform(ElemType key[64], ElemType tempbts[56]){
int cnt;
for(cnt = 0; cnt < 56; cnt++){
tempbts[cnt] = key[PC_1[cnt]];//按PC1的顺序将key数组的字符存入到tempbts
}
return 0;
}
/*置换选择2*/
int DES_PC2_Transform(ElemType key[56], ElemType tempbts[48]){
int cnt;
for(cnt = 0; cnt < 48; cnt++){
tempbts[cnt] = key[PC_2[cnt]];
}
return 0;
}
/*循环左移*/
int DES_ROL(ElemType data[56], int time){
ElemType temp[56];
/*保存将要循环移动到右边的位*/
memcpy(temp,data,time); //void *memcpy( void *dest, const void *src, size_t count );
memcpy(temp+time,data+28,time);
/*前28位移动*/
memcpy(data,data+time,28-time);
memcpy(data+28-time,temp,time);
/*后28位移动*/
memcpy(data+28,data+28+time,28-time);
memcpy(data+56-time,temp+time,time);
return 0;
}
/*IP置换*////第一步
int DES_IP_Transform(ElemType data[64]){
int cnt;
ElemType temp[64];
for(cnt = 0; cnt < 64; cnt++){
temp[cnt] = data[IP_Table[cnt]];//data中数据以IP_Table的顺序存储在temp中
}
memcpy(data,temp,64);//更新data数组
return 0;
}
/*IP逆置换*/
int DES_IP_1_Transform(ElemType data[64]){
int cnt;
ElemType temp[64];
for(cnt = 0; cnt < 64; cnt++){
temp[cnt] = data[IP_1_Table[cnt]];
}
memcpy(data,temp,64);
return 0;
}
/*选择运算E*/
int DES_E_Transform(ElemType data[48]){
int cnt;
ElemType temp[48];
for(cnt = 0; cnt < 48; cnt++){
temp[cnt] = data[E_Table[cnt]];//data中数据以E_Table的顺序存储在temp中
}
memcpy(data,temp,48);
return 0;
}
/*P置换--S盒输出的32位数据打乱*/
int DES_P_Transform(ElemType data[32]){
int cnt;
ElemType temp[32];
for(cnt = 0; cnt < 32; cnt++){
temp[cnt] = data[P_Table[cnt]];//data中数据以P_Table的顺序存储在temp中
}
memcpy(data,temp,32);
return 0;
}
/*异或--模2加运算*/
int DES_XOR(ElemType R[48], ElemType L[48] ,int count){
int cnt;
for(cnt = 0; cnt < count; cnt++){
R[cnt] ^= L[cnt];
}
return 0;
}
/*S盒置换*/
int DES_SBOX(ElemType data[48]){
int cnt;
int line,row,output;
int cur1,cur2;
for(cnt = 0; cnt < 8; cnt++){
cur1 = cnt*6;
cur2 = cnt<<2; /*cur2=cnt*4;*/
/*计算在S盒中的行与列*/
line = (data[cur1]<<1) + data[cur1+5];
row = (data[cur1+1]<<3) + (data[cur1+2]<<2) + (data[cur1+3]<<1) + data[cur1+4];
output = S[cnt][line][row];
/*化为2进制*/
data[cur2] = (output&0X08)>>3;
data[cur2+1] = (output&0X04)>>2;
data[cur2+2] = (output&0X02)>>1;
data[cur2+3] = output&0x01;
}
return 0;
}
/*交换*/
int DES_Swap(ElemType left[32], ElemType right[32]){
ElemType temp[32];
memcpy(temp,left,32);
memcpy(left,right,32);
memcpy(right,temp,32);
return 0;
}
/*加密单个分组*/
int DES_EncryptBlock(ElemType plainBlock[8], ElemType subKeys[16][48], ElemType cipherBlock[8]){
ElemType plainBits[64];
ElemType copyRight[48];
int cnt;
Char8ToBit64(plainBlock,plainBits);
/*初始置换（IP置换）*/
DES_IP_Transform(plainBits);
/*16轮迭代*/
for(cnt = 0; cnt < 16; cnt++){
memcpy(copyRight,plainBits+32,32);//取右边32位
/*将右边32位进行扩展置换，从32位扩展到48位*////原明文操作
DES_E_Transform(copyRight);
/*将右边32位与子密钥进行异或操作*/
DES_XOR(copyRight,subKeys[cnt],48);
/*异或结果进入S盒，输出32位结果*/
DES_SBOX(copyRight);
/*P置换*/
DES_P_Transform(copyRight);
/*将明文左边32位与右边32位进行异或*/
DES_XOR(plainBits,copyRight,32);
if(cnt != 15){
/*最后完成左右两边的交换*/
DES_Swap(plainBits,plainBits+32);
}
}
/*逆初始置换（IP^1置换）*/
DES_IP_1_Transform(plainBits);
Bit64ToChar8(plainBits,cipherBlock);//cipherBlock是输出的密文
return 0;
}
/*解密单个分组*/
int DES_DecryptBlock(ElemType cipherBlock[8], ElemType subKeys[16][48],ElemType plainBlock[8]){
ElemType cipherBits[64];
ElemType copyRight[48];
int cnt;
Char8ToBit64(cipherBlock,cipherBits);
/*初始置换（IP置换）*/
DES_IP_Transform(cipherBits);
/*16轮迭代*/
for(cnt = 15; cnt >= 0; cnt--){
memcpy(copyRight,cipherBits+32,32);
/*将右边32位进行扩展置换，从32位扩展到48位*/
DES_E_Transform(copyRight);
/*将右边32位与子密钥进行异或操作*/
DES_XOR(copyRight,subKeys[cnt],48);
/*异或结果进入S盒，输出32位结果*/
DES_SBOX(copyRight);
/*P置换*/
DES_P_Transform(copyRight);
/*将明文左边32位与右边32位进行异或*/
DES_XOR(cipherBits,copyRight,32);
if(cnt != 0){
/*最后完成左右两边的交换*/
DES_Swap(cipherBits,cipherBits+32);
}
}
/*逆初始置换（IP^1置换）*/
DES_IP_1_Transform(cipherBits);
Bit64ToChar8(cipherBits,plainBlock);
return 0;
}
int format(){
fstream file;
file.open("/Users/fenglunli/Desktop/des_message.txt",ios::in);
int i = 0;
ElemType m;
while(file.peek()!=EOF){
file >> m;
i++;
}
file.close();
return i;
}
void fun(ElemType* m1, ElemType* m2, ElemType* k, bool des){
ElemType temp[64];//64位密钥
Char8ToBit64(k,temp);//
DES_IP_Transform(temp);//IP置换//temp已更新
ElemType subkeys[16][48];//子密钥
DES_MakeSubKeys(temp,subkeys);//16子密钥
if(des)
DES_EncryptBlock(m1,subkeys,m2);//cout<<"密文为:";
else
DES_DecryptBlock(m1,subkeys,m2);//cout<<"明文为:";
}
void fun2(ElemType* k, bool des, int n){
fstream file_in("/Users/fenglunli/Desktop/des_message.txt", ios::in);//读入
fstream file_out("/Users/fenglunli/Desktop/des_password.txt", ios::out | ios::app);//写出
fstream file_in2("/Users/fenglunli/Desktop/des_password.txt", ios::in);
fstream file_out2("/Users/fenglunli/Desktop/des_p2m.txt", ios::out | ios::app);
ElemType message[8], password[8], p2m[8];
int time = n/8, num = n%8;
if(des){
//while(file_in.peek() != EOF){
for(int j=0;j<time;j++){
for(int i=0;i<8;i++)
file_in >> message[i];
fun(message, password, k, true);
for(int i=0;i<8;i++)
file_out << password[i];
}
for(int i=0;i
file_in >> message[i];
fun(message, password, k, true);
for(int i=0;i
file_out << password[i];
}else{
//while(file_in2.peek() != EOF){
for(int j=0;j<time;j++){
for(int i=0;i<8;i++)
file_in2 >> password[i];
fun(password, p2m, k, false);
/*if(file_in2.peek() == EOF)
for(int i=0;i
file_out2 << p2m[i];
else
for(int i=0;i<8;i++)
file_out2 << p2m[i];*/
for(int i=0;i<8;i++)
file_out2 << p2m[i];
}
for(int i=0;i
file_in2 >> password[i];
fun(password, p2m, k, false);
for(int i=0;i
file_out2 << p2m[i];
}
file_in.close();
file_out.close();
file_in2.close();
file_out2.close();
}
int main(){
int n = format();
//int time = n/8, num = n%8;
fstream file_out("/Users/fenglunli/Desktop/des_password.txt",ios::out);
file_out << "";
fstream file_out2("/Users/fenglunli/Desktop/des_p2m.txt",ios::out);
file_out2 << "";
ElemType key[8];
cout<<"请选择 1:加密; 其他:解密:";
int c;
while(cin>>c){
cout<<"请输入密钥:";
for(int i=0;i<8;i++){
key[i] = getchar();
if(key[i]<48 || key[i]>122)
i--;
}
fun2(key, c==1, n);
cout<<"请选择 1:加密; 其他:解密:";
}
return 0;
}
（2）测试：
第一步：准备好测试文件，由于任意长度均可测试，此处取14个字符：
第二步：解密时先输入错误的密钥：
然后发现解密输出文件时乱码，无法打开：
第三步：输入正确的密钥：
这时再打开解密后的文件，与明文一致，实验成功！
/*好像传不了图片，有空再补吧*/