#include<iostream.h>
#include<time.h>
#include<windows.h>
#include<iomanip.h>
void LS(int A[28]) //移位函数
{
int h=A[0];
for(int i=0;i<27;i++){
A[i]=A[i+1];
}
A[27]=h;
}
void Key_Generation(int K[56],int n,int Kn[48]) //子密钥生成函数,n为加密回合数(1~16)。
{
int t[64],k[56],m; //m用来计1的个数,这里采用奇校验。
for(int i=0;i<8;i++){
m=0;
for(int j=0;j<7;j++){
t[8*i+j]=K[7*i+j];
if(K[7*i+j]==1) m++;
}
if(m%2==0) t[8*i+7]=1;
else t[8*i+7]=0; //加奇偶校验位,变成64位t[64]。
}
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
};
for(i=0;i<56;i++){
k[i]=t[PC_1[i]-1];
} //除去奇偶校验位,又变为56位k[56]。
int C[28],D[28];
for(i=0;i<28;i++) C[i]=k[i];
for(int j=0;j<28;j++) D[j]=k[j+28];
int p[16],q=0;
for(i=0;i<16;i++){
if(i==0||i==1||i==8||i==15) p[i]=1;
else p[i]=2;
}
for(i=0;i<n;i++) q+=p[i];
for(j=0;j<q;j++){
LS(C);
LS(D);
}
for(i=0;i<28;i++) k[i]=C[i];
for(j=0;j<28;j++) k[j+28]=D[j]; //经过移位重新组成的密钥k[56]。
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
};
for(i=0;i<48;i++){
Kn[i]=k[PC_2[i]-1];
} //得到48位子密钥Kn
}
void IP(int a[64]) //IP变换
{
int b[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
};
int c[64];
for(int i=0;i<64;i++){
c[i]=a[b[i]-1];
}
for(i=0;i<64;i++){
a[i]=c[i];
}
}
void IP_R(int a[64]) //IP逆变换
{
int b[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
};
int c[64];
for(int i=0;i<64;i++){
c[i]=a[b[i]-1];
}
for(i=0;i<64;i++){
a[i]=c[i];
}
}
void E(int a[32],int c[48]) //扩增置换E(32->48)
{
int b[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
};
for(int i=0;i<48;i++){
c[i]=a[b[i]-1];
}
}
void XOR(int l,int *pa,int *pb,int *pc) //异或函数
{
for(int i=0;i<l;i++){
if(*pa==*pb) *pc=0;
else *pc=1;
pa++;
pb++;
pc++;
}
}
void S(int b[8][6],int d[8][4])
{
int S[8][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,
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,
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,
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,
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,
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,
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,
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,
};
int r,c,v;
for(int i=0;i<8;i++){
r=2*b[i][0]+b[i][5];
c=8*b[i][1]+4*b[i][2]+2*b[i][3]+b[i][4];
v=S[i][r][c];
d[i][0]=v/8;
d[i][1]=(v-8*d[i][0])/4;
d[i][2]=(v-8*d[i][0]-4*d[i][1])/2;
d[i][3]=v-8*d[i][0]-4*d[i][1]-2*d[i][2];
}
}
void P(int a[32],int c[32])
{
int b[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
};
for(int i=0;i<32;i++){
c[i]=a[b[i]-1];
}
}
void DES(int M[64],int K[56],int C[64]) //DES加密函数
{
int m[64],L0[32],R0[32],L1[32],R1[32];
for(int i=0;i<64;i++){
m[i]=M[i];
}
IP(m);
for(i=0;i<32;i++) L0[i]=m[i];
for(int j=0;j<32;j++) R0[j]=m[j+32];
for(int n=1;n<=16;n++){
for(i=0;i<32;i++){
L1[i]=R0[i];
}
int Kn[48],s[48],B[48],b[8][6]; //m[32]扩增得到s[48]
E(R0,s);
Key_Generation(K,n,Kn);
XOR(48,s,Kn,B); //s[48]与Kn异或得到B[48]
for(i=0;i<8;i++)
for(j=0;j<6;j++)
b[i][j]=B[6*i+j];
int d[8][4],D[32],F[32];
S(b,d); //通过S盒将b[8][6]变换为d[8][4]
for(i=0;i<8;i++)
for(j=0;j<4;j++)
D[4*i+j]=d[i][j];
P(D,F); //缩减置换P(32->32)
XOR(32,L0,F,R1);
for(i=0;i<32;i++){
L0[i]=L1[i]; //迭代
R0[i]=R1[i];
}
}
int temp[32];
for(i=0;i<32;i++){
temp[i]=L0[i];
L0[i]=R0[i];
R0[i]=temp[i];
}
for(i=0;i<32;i++) m[i]=L0[i];
for(j=0;j<32;j++) m[j+32]=R0[j];
IP_R(m);
for(i=0;i<64;i++){
C[i]=m[i];
}
}
void DES_R(int C[64],int K[56],int M[64]) //DES解密函数
{
int c[64],L0[32],R0[32],L1[32],R1[32];
for(int i=0;i<64;i++){
c[i]=C[i];
}
IP(c);
for(i=0;i<32;i++) L0[i]=c[i];
for(int j=0;j<32;j++) R0[j]=c[j+32];
for(int n=1;n<=16;n++){
for(i=0;i<32;i++){
L1[i]=R0[i];
}
int Kn[48],s[48],B[48],b[8][6];
E(R0,s);
Key_Generation(K,17-n,Kn); //子密钥从K16至K1产生
XOR(48,s,Kn,B);
for(i=0;i<8;i++)
for(j=0;j<6;j++)
b[i][j]=B[6*i+j];
int d[8][4],D[32],F[32];
S(b,d);
for(i=0;i<8;i++)
for(j=0;j<4;j++)
D[4*i+j]=d[i][j];
P(D,F);
XOR(32,L0,F,R1);
for(i=0;i<32;i++){
L0[i]=L1[i];
R0[i]=R1[i];
}
}
int temp[32];
for(i=0;i<32;i++){
temp[i]=L0[i];
L0[i]=R0[i];
R0[i]=temp[i];
}
for(i=0;i<32;i++) c[i]=L0[i];
for(j=0;j<32;j++) c[j+32]=R0[j];
IP_R(c);
for(i=0;i<64;i++){
M[i]=c[i];
}
}
void main()
{
char c;
int i,j,M[64],K[56],C[64];
cout<<"请选择明文M及初始密钥K生成方式"<<endl<<"a 手动输入"<<"\t"<<"b 随机生成"<<endl<<"请选择:";
cin>>c;
switch(c){
case 'a':{
cout<<"输入64位明文M:"<<endl;
for(i=0;i<64;i++){
cin>>M[i];
}
cout<<"输入56位初始密钥K:"<<endl;
for(j=0;j<56;j++){
cin>>K[j];
}
} break;
case 'b':{
srand(GetTickCount());
for(i=0;i<64;i++){
M[i]=rand()%2;
}
for(j=0;j<56;j++){
K[j]=rand()%2;
}
} break;
default:;
}
cout<<"明文M:"<<endl;
for(i=0;i<64;i++){
cout<<setw(2)<<M[i];
if(i%8==7) cout<<endl;
}
cout<<"密钥K:"<<endl;
for(j=0;j<56;j++){
cout<<setw(2)<<K[j];
if(j%8==7) cout<<endl;
}
DES(M,K,C);
cout<<"密文C:"<<endl;
for(i=0;i<64;i++){
cout<<setw(2)<<C[i];
if(i%8==7) cout<<endl;
}
DES_R(C,K,M);
cout<<"解密得到的明文M:"<<endl;
for(i=0;i<64;i++){
cout<<setw(2)<<M[i];
if(i%8==7) cout<<endl;
}
}