des.h

本程序的实现des加解密的功能

#include <stdio.h>
#include <malloc.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
/*
author: 李云飞   yunnan university
*/
//定义ip置换表
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
};

//定义ip逆置换表
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
};

//定义e置换表
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
};

//定义p置换表
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
};

//定义pc1置换表
int PC1[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
};

//定义pc2置换表
int PC2[] = {
	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
};

//定义循环移位表
int LOOP[16] = {
	1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
};

//定义s盒
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
};

int change(char *w,int l)
{
	int  j=0,k=0;
    int end=0,f;
	for(k=(l-1),j=0 ;  k>=0 ;j++,k--)
	{ 
		f=(int)pow(2,j);
        end=end+(w[k]-'0')*f;
	}
	return end;
}

int getbit(int i,int *arg,unsigned long e1,unsigned long e2,int l)
{
	unsigned long end1=e1,end2=e2;
	         int k=arg[i];  //得到替换表的数值
    if       (k>0 && k<=32) //因64位数是由两个unsigned long型来存放的
             { 
			 end1=end1>>(l-k); //，所以在替换的时候要分成两部分来处理
			 return (end1%2);
			 }
	else if(k>32 && k<=64)
             {
			 end2=end2>>(l-k+32);
			 return (end2%2);
			 }
	else return -1;
}

int getb(int i,int l,unsigned int end)
{
	 unsigned int e=end;
	          e=e>>(l-i);		
			  return (e%2);
}

int getb1(int i,int l,unsigned long end)
{
	 unsigned long   e=end;
	           int    k=l-i;
	              e=e>>k;
		          return (e%2);
}

unsigned long * getCharbit(char* s)
{
	unsigned int a;
	unsigned long e=0,*r;
    int i,j,k,l,h,d;
    r=(unsigned long*)malloc(2*sizeof(unsigned long)); 
	for(h=0,d=0;h<2;h++){
	for(l=0,j=32;l<4;l++,d++)
	{
       a=(unsigned int)s[d];
	
    for(i=1;i<=8;i++,j--)
	{
		k=getb(i,8,a);
        k=k<<(j-1);
		e=e|k;
	}
    }
	r[h]=e;
	   e=0;
	}
	return r;
}

void get56bit(unsigned long *n,unsigned long *e)
{
  unsigned long e1=0,e2=0; 
  unsigned int i=0,k,h=24,l=32; 
  for(i=0;i<56;i++)
  {
   k=getbit(i,PC1, n[0],n[1],32);
   if(i<24)
   {
	   k=k<<(h-1);
	   e1=e1|k;
	   h--;
   }
   if(i>=24)
   {
	   k=k<<(l-1);
	   e2=e2|k;
	   l--;
   }
  }
  e[0]=e1;  //e1存放的是前24位
  e[1]=e2;  //e2存放的是后32位

}

unsigned long * delevkey(unsigned long  *e )
{
          unsigned long *c,e1,e2;
		  unsigned int i,k,j,m=0;
          c=(unsigned long *)malloc(2*sizeof(unsigned long));
		  if(!c){printf("malloc is wrong!(delevkey)"); exit(0);} //////////////////
          c[0]=c[1]=0;
		  e1=e[0];
          e2=e[1];	  
		  e1=e1<<4;
		  c[0]=c[0]|e1;
          for(i=1,j=4;i<=4;i++,j--)//得到前28位
		  {
          k=getb1(i,32,e2);
		  k=k<<(j-1);
          c[0]=c[0]|k;
		  }
		  for(i=5,j=28;i<=32;i++,j--)//得到后28位 
		  {
            k=getb1(i,32,e[1]);
		    k=k<<(j-1);
            c[1]=c[1]|k;
		  }
		  return c;	      
}

char  * whbit(char *e,int l,int s)
{
	 char *a;
	 int i,j=s,h=l; 
	 a=(char *)malloc(l*sizeof(char));
     if(!a){printf("malloc is wrong!(whbit)"); exit(0);} //////////////////
	 for(i=0,h=h-j;i<j && h<l;i++,h++)
       a[h]=e[i];
	 for(h=0;i<l;h++,i++)
	   a[h]=e[i];
     return a;  
}

char * changeInt(unsigned long m,int l)
{
	unsigned long n=m;
          int    i,e;
          char  *a;
   a=(char *)malloc(l*sizeof(char));
   if(!a){printf("malloc is wrong!(changeInt)"); exit(0);} //////////////////
   for(i=0;n!=1 && i<l;i++)
	{    
		 e=n%2;
		 a[i]=(char)(e+'0');
		 n=n/2   ;
	}
	a[i]=(char)n+'0';	
	a[i+1]='\0';
	return a;
}

char * interger(unsigned long m,int l)
{
   char  *a,*b;
   int   i,j,k=0;
   a=(char *)malloc(l*sizeof(char));
   if(!a){printf("malloc is wrong!(interger)"); exit(0);} //////////////////
   b=(char *)malloc(l*sizeof(char)); 
   if(!b){printf("malloc is wrong!(interger)"); exit(0);} //////////////////
   a=changeInt(m,l);
   i=strlen(a);
   if(i<l)
   for(j=0;j<(l-i);j++)
	   b[j]='0';
   else j=0; 
   for(i=(strlen(a)-1);i>=0 && k<l ;i-- ,j++,k++)
      b[j]=a[i];     
   b[j]='\0';
   return b;
}

char * together(char * c,char *d,int l)
{
   	char  *e;
    int i,j;
	e=(char *)malloc((2*l)*sizeof(char));
    if(!e){printf("malloc is wrong!(interger)"); exit(0);} //////////////////
	strncpy(e, c, l);  
	for(i=l,j=0;i<2*l;i++,j++)
	 e[i]=d[j];
	return e;
}

char *query(char *e,char *n)