DES加密解密的C++源程序
--测试版本，希望大家多多交流
#include<iostream.h>
#include"stdio.h"
#include"math.h"
#include "string.h"
static char key[16][48];
static char Hex[16][4];
////IP置换。
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-1置换。可根据IP表生成
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 \
};
//E扩展
int E[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
};
//PC-1置换。
int PC_1[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
};
//PC-2置换。
int PC_2[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
};
//P置换
int P[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
};
int S[8][4][16] =
//S盒1。 S盒都可以自己设置
{
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,
//S盒2
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,
//S盒3
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,
//S盒4
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,
//S盒5
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,
//S盒6
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,
//S盒7
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,
//S盒8
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
};
void Init_Hex()
{
}
void LS(char src[28],char dist[28],int n)
//将28比特的字符串循环左移n位
{
for(inti=0;i<28;i++)
dist[i]= src[(28-n+i)%28];
}
void Decompose_56(char src[56],chardist1[28],char dist2[28])
//将56比特的字符串分解为2个28比特的字符串
{
}
void Decompose_64(char src[64],chardist1[32],char dist2[32])
//将一个64比特的字符串分解为两个32位的字符串
{}
void Combine_56(char src1[28],charsrc2[28],char dist[56])
//将两个28比特的字符串合并成一个56比特的字符串
{}
void Combine_64(char src1[32],charsrc2[32],char dist[64])
//将两个32比特的字符串合并成一个64比特的字符串
{
for(inti=0;i<32;i++)
dist[i]= src1[i];
for(intj=32;j<64;j++)
dist[j]= src2[j-32];
}
void PC_1_Permutation(char src[64],chardist[56])
//PC-1置换
{
for(inti=0;i<56;i++)
dist[i]= src[PC_1[i]-1];
}
void PC_2_Permutation(char src[56],chardist[48])
//PC-2置换
{
for(inti=0;i<64;i++)
dist[i]= src[PC_2[i]-1];
}
void IP_Permutation(char src[64],chardist[64])
//IP置换
{
for(inti=0;i<64;i++)
dist[i]= src[IP[i]-1];
}
void IP_1_Permutation(char src[64],chardist[64])
//IP的逆置换
{
for(inti =0;i<64;i++)
dist[i]=src[IP_1[i]-1];
}
void E_Permutation(char src[32],chardist[48])
//E置换
{
for(inti=0;i<48;i++)
dist[i]= src[E[i]-1];
}
void P_Permutation(char src[32],chardist[32])
//P置换
{
for(inti=0;i<32;i++)
dist[i]= src[P[i]-1];
}
void StrCpy(char src[],char dist[],int n)
//字符串的复制
{
for(inti=0;i<n;i++)
dist[i]= src[i];
}
void S_Permutation(char src[6],chardist[4],int n)
//第n个S盒的置换
{
Init_Hex();
inti,j,k,m[4];
i=n;
if((src[0]==‘0‘)&&(src[5]==‘0‘))
j= 0;
elseif((src[0]==‘0‘)&&(src[5]==‘1‘))
j= 1;
elseif((src[0]==‘1‘)&&(src[5]==‘0‘))
j= 2;
else
j= 3;
for(inttemp_i=1;temp_i<5;temp_i++)
{
if(src[temp_i]==‘1‘)
m[temp_i-1]= 1;
else
m[temp_i-1]= 0;
}
k= m[3]+2*m[2]+4*m[1]+8*m[3];
StrCpy(Hex[(S[i][j][k])],dist,4);
}
void Make_Key(char k[64])
//产生密钥
{
charTemp_Key[56];
PC_1_Permutation(k,Temp_Key);
charTemp_C[28],Temp_D[28],Temp_C0[28],Temp_D0[28];
Decompose_56(Temp_Key,Temp_C0,Temp_D0);
for(inti=0;i<16;i++)
{
if((i==0)||(i==1)||(i==8)||(i==15))
{
LS(Temp_C0,Temp_C,1);
LS(Temp_D0,Temp_D,1);
}
else
{
LS(Temp_C0,Temp_C,2);
LS(Temp_D0,Temp_D,2);
}
Combine_56(Temp_C,Temp_D,key[i]);
StrCpy(Temp_C0,Temp_C,28);
StrCpy(Temp_D0,Temp_D,28);
}
}
void XOR(char src[48],char dist[48])
//将两个48比特的字符串进行异或
{
for(inti=0;i<48;i++)
{
if(src[i]== dist[i])
dist[i]= ‘0‘;
else
dist[i]= ‘1‘;
}
}
void F_Function(char R[32],chardist[32],int n)
//第n次轮函数
{
chartemp[48],A[8][6],C[8][4],temp_dist[32];
E_Permutation(R,temp);
XOR(key[n],temp);
for(inti=0;i<8;i++)
{
for(intj=0;j<6;j++)
{
A[i][j]= temp[8*i+j];
}
}
for(i=0;i<8;i++)
{
S_Permutation(A[i],C[i],i);
}
for(i=0;i<4;i++)
{
temp_dist[i]= C[0][i];
}
for(i=4;i<8;i++)
{
temp_dist[i]= C[1][i+4];
}
for(i=8;i<12;i++)
{
temp_dist[i]= C[2][i+8];
}
for(i=12;i<16;i++)
{
temp_dist[i]= C[3][i+12];
}
for(i=16;i<20;i++)
{
temp_dist[i]= C[4][i+16];
}
for(i=20;i<24;i++)
{
temp_dist[i]= C[5][i+20];
}
for(i=24;i<28;i++)
{
temp_dist[i]= C[6][i+24];
}
for(i=28;i<32;i++)
{
temp_dist[i]= C[7][i+28];
}
P_Permutation(temp_dist,dist);
}
void Char2bitchar(char src[8],chardist[64])
//将一个任意的8字符串转换为比特串
{
inttemp;
for(inti=0;i<8;i++)
{
temp= (int)src[i];
for(intj=0;j<8;j++)
{
if((temp%2)== 1)
dist[8*(i+1)-(j+1)]= ‘1‘;
else
dist[8*(i+1)-(j+1)]= ‘0‘;
temp= int(temp/2);
}
}
}
void Bitchar2char(char src[64],chardist[8])
//将一个8字符串转换为一个64比特字符串
{
inttemp =0;
for(inti=0;i<8;i++)
{
for(intj=0;j<8;j++)
{
if(src[8*i+j]== ‘1‘)
temp+= int(pow(2,7-j));
}
dist[i]= char(temp);
temp= 0;
}
}
void Encryption(char temp_src[8],chartemp_dist[8],char temp_key[8])
//DES加密过程
{
charsrc[64],dist[64],Key[64];
Char2bitchar(temp_src,src);
Char2bitchar(temp_key,Key);
Make_Key(Key);
chartemp[64],temp_L[32],temp_R[32],L[32],R[32];
IP_Permutation(src,temp);
/*for(intj=0;j<64;j++)
cout<<temp[j];
cout<<endl;*/
Decompose_64(temp,temp_L,temp_R);
for(inti=0;i<16;i++)
{
StrCpy(temp_R,L,32);
F_Function(temp_R,R,i);
XOR(temp_L,R);
StrCpy(R,temp_R,64);
StrCpy(L,temp_L,64);
}
Combine_64(temp_R,temp_L,temp);
IP_1_Permutation(temp,dist);
Bitchar2char(dist,temp_dist);
}
void DeMake_Key(char k[64])
//产生密钥
{
chartemp = ‘0‘;
for(inti=0;i<8;i++)
{
for(intj=0;j<48;j++)
{
temp= key[i][j];
key[i][j]= key[15-i][j];
key[15-i][j]= temp;
}
}
}
void Decryption(char temp_src[8],chartemp_dist[8],char temp_key[8])
//DES解密过程
{
charsrc[64],dist[64],Key[64];
Char2bitchar(temp_src,src);
Char2bitchar(temp_key,Key);
DeMake_Key(Key);
chartemp[64],temp_L[32],temp_R[32],L[32],R[32];
IP_Permutation(src,temp);
/*for(intj=0;j<64;j++)
cout<<temp[j];
cout<<endl;*/
Decompose_64(temp,temp_L,temp_R);
for(inti=0;i<16;i++)
{
StrCpy(temp_R,L,32);
F_Function(temp_R,R,i);
XOR(temp_L,R);
StrCpy(R,temp_R,64);
StrCpy(L,temp_L,64);
}
Combine_64(temp_R,temp_L,temp);
IP_1_Permutation(temp,dist);
Bitchar2char(dist,temp_dist);
}
原文：http://blog.csdn.net/u014316433/article/details/26342227