des.cpp

密码学实验自己写的程序

#include<stdio.h>
#include<string.h>
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};
int IPN[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 keyp[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};
int k1[28]={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};
int k2[28]={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};
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};
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 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};
int 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};
int 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};
int s4[4][16]={7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15,13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9,10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4,3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14};
int 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};
int 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};
int 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};
int 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};
int lmove[16]={1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1};
int character[64];
int d[64];
int L[32];
int R[32];
int key[48];
char zifu[8];
int z1[28];
int z2[28];
struct node
{
	unsigned a:1;
	unsigned b:1;
	unsigned c:1;
	unsigned d:1;
	unsigned e:1;
	unsigned f:1;
	unsigned g:1;
	unsigned h:1;
}data;
void fuzhi(int *z,int *K)
{
	for(int i=0;i<28;i++)
		z[i]=character[K[i]-1];   	
}
void tb()//生成64位数据流；
{	
    int j=0;
    for(int i=0;i<8;i++)
	{	
		j=i*8;
		data.a=zifu[i];
       	data.b=(zifu[i]>>1);
    	data.c=(zifu[i]>>2);
    	data.d=(zifu[i]>>3);
    	data.e=(zifu[i]>>4);
    	data.f=(zifu[i]>>5);
    	data.g=(zifu[i]>>6);
    	data.h=(zifu[i]>>7);
		character[j]=data.a;
	    character[j+1]=data.b;
	    character[j+2]=data.c;
	    character[j+3]=data.d;
	    character[j+4]=data.e;
	    character[j+5]=data.f;
	    character[j+6]=data.g;
	    character[j+7]=data.h;
	 }
}
int s_box(int *c,int m,int count,int s[4][16])
{	 
	int num,row,low;
	row=(c[m-5]<<1)+c[m];
    low=(c[m-4]<<3)+(c[m-3]<<2)+(c[m-2]<<1)+c[m-1];
    num=s[row][low];
	data.a=num;
	data.b=num>>1;
	data.c=num>>2;
	data.d=num>>3;
	R[count++]=data.d;
	R[count++]=data.c;	
	R[count++]=data.b;
	R[count++]=data.a;
	return count;
}
void R_L(int *l,int *r)
{
	for(int i=0;i<32;i++)
		l[i]=r[i];
}
void Fes(int *l,int *r)
{
	int L1[32],c[48],s[32];
	  R_L(L1,r);
      for(int x=0;x<48;x++)
		  c[x]=r[E[x]-1];
      for(int j=0;j<48;j++)
		  c[j]=c[j]^key[j];
	  int count=0;
      for(int m=0;m<48;m++)
	  { 
		  if(m==5) count=s_box(c,m,count,s1);
		  if(m==11)count=s_box(c,m,count,s2);
		  if(m==17)count=s_box(c,m,count,s3);
		  if(m==23)count=s_box(c,m,count,s4);
		  if(m==29)count=s_box(c,m,count,s5); 
		  if(m==35)count=s_box(c,m,count,s6);
		  if(m==41)count=s_box(c,m,count,s7);
		  if(m==47)count=s_box(c,m,count,s8);
	  }
	  for(int i=0;i<32;i++)	  
		  s[i]=r[P[i]-1];
	  for(int i1=0;i1<32;i1++)
	  {
		  r[i1]=l[i1]^s[i1];
	  }
      R_L(l,L1);
}

void KEY(int x)
{
	int temp[56],t1,t2,t3,t4;
	if(x==1)
	{
		t1=z1[0];t2=z2[0];
		for(int i1=1;i1<28;i1++)
		{
			z1[i1-1]=z1[i1];
	    	z2[i1-1]=z2[i1];
		}
		z1[27]=t1;
		z2[27]=t2;
	}
	if(x==2)
	{
      	t1=z1[0];t2=z1[1];t3=z2[0];t4=z2[1];
		for(int i1=2;i1<28;i1++)
		{
			z1[i1-2]=z1[i1];
			z1[i1-1]=z1[i1+1];
	    	z2[i1-2]=z2[i1];
			z2[i1-1]=z2[i1+1];
		}
		z1[26]=t1;z1[27]=t2;
		z2[26]=t3;z2[27]=t4;
	}
	for(int i=0;i<56;i++)
	{
		if(i<28)
			temp[i]=z1[i];
		if(i>=28)
			temp[i]=z2[i-28];
	}
	for(int j=0;j<48;j++)
		key[j]=temp[keyp[j]-1];
}
void KEY2(int x)
{
	int temp[56],t1,t2,t3,t4;
	if(x==1)
	{
        t1=z1[27];t2=z2[27];
		for(int i1=26;i1>=0;i1--)
		{
			z1[i1+1]=z1[i1];
	    	z2[i1+1]=z2[i1];
		}
		z1[0]=t1;
		z2[0]=t2;
	}
	if(x==2)
	{
        t1=z1[27];t2=z1[26];t3=z2[27];t4=z2[26];
		for(int i1=24;i1>=0;i1--)
		{
			z1[i1+3]=z1[i1+1];
	    	z1[i1+2]=z1[i1];
			z2[i1+3]=z2[i1+1];
	    	z2[i1+2]=z2[i1];
		}
		z1[1]=t1;z1[0]=t2;
		z2[1]=t3;z2[0]=t4;
	}	
	for(int i=0;i<56;i++)
	{
		if(i<28)
			temp[i]=z1[i];
		if(i>=28)
			temp[i]=z2[i-28];
	}
	for(int j=0;j<48;j++)
	{   
		key[j]=temp[keyp[j]-1];
	}
}
void output()
{
	for(int i=0;i<64;i++)
	{
		if(i%8==0)
	    	putchar('\n');
    	printf("%3d",d[i]);
	}
}
void zhihuan()
{
	for(int i=0;i<64;i++)
		d[i]=character[IPN[i]-1];
}
void keyInterlan()
{
	tb();
    fuzhi(z1,k1);
    fuzhi(z2,k2);
}
void DES()
{
	tb();
	for(int i=0;i<64;i++)
	{
	    if(i<32)
			L[i]=character[IP[i]-1];
		if(i>=32)
		    R[i-32]=character[IP[i]-1];
	}
    for(int j=0;j<16;j++)
	{	   
		KEY(lmove[j]);
		Fes(L,R);
	}
    for(i=0;i<64;i++)
	{
		if(i<32)
		    character[i]=R[i];
	    if(i>=32)
		    character[i]=L[i-32];
	}
    zhihuan();
    printf("加密后的密文\n");
    output();
}
void fanDES()
{
    for(int i=0;i<64;i++)
	{
	    if(i<32)
		    L[i]=d[IP[i]-1];
	    if(i>=32)
		    R[i-32]=d[IP[i]-1];
	}
	for(int j=15;j>=0;j--)
	{  
		Fes(L,R);
	    KEY2(lmove[j]);
	}
    for(i=0;i<64;i++)
	{
	    if(i<32)
		    character[i]=R[i];
	    if(i>=32)
		    character[i]=L[i-32];
	}
    for(int t=0;t<64;t++)
	    d[t]=character[IPN[t]-1];
    printf("解密后的原文\n");
	output();
/*    for(int z=0;z<64;z++)
	{
		if(z!=0&&z%8==0)
            putchar('\n');
	    printf("%3d",d[z]);
	}*/
}
void main()
{    
	
	printf("请输入密钥KEY\n");
    scanf("%s",zifu);
    keyInterlan();
    printf("请输入明文M\n");
    scanf("%s",zifu);
	DES();
    putchar('\n');putchar('\n');putchar('\n');
    fanDES();
}