untitled4.cpp

C语言编写的des加密和解密算法

#include<stdio.h>
void output(int text[],int num)
{
	int i;
	for(i=0;i<num;i++)
	{
	   printf("%d ",text[i]);
	   if(i%8==7)
	   putchar('\n');
	}
}
void transport(int text[],int table[],int num)
{
	int i;
	int tem[64];
	for(i=0;i<64;i++)
	   tem[i]=text[i];
    for(i=0;i<num;i++)
       text[i]=tem[table[i]-1];
//    printf("reduce key:\n");
//    output(text,56);
}
void moveleft(int *L,int num,int amount)
{
	int first;
	int *p;
	first=*L;
	for(p=L;p<L+num-1;p++)
	    *p=*(p+1);
    *(L+num-1)=first;
    amount--;
    if(amount>0) moveleft(L,num,amount);
}
void moveright(int *R,int num,int amount)
{
	int end;
	int *p;
	end=*(R+num-1);
	for(p=R+num-1;p>R;p--)
	   *p=*(p-1);
    *R=end;
    amount--;
    if(amount>0) moveright(R,num,amount);
}	
void nonlineartransport(int text1[],int text2[],int table[])
{
	int i;
	for(i=0;i<48;i++)
	    text1[i]=text2[table[i]-1];
}
void operation(int text1[],int text2[],int num)
{
	int i;
	for(i=0;i<num;i++)
	{
		if(text1[i]==text2[i])
		   text1[i]=0;
        else text1[i]=1;
    //    printf("%d",text1[i]);
	}
}
void F(int rightext[],int Key[])
{
	int expansionrightext[48];
    int expansiontable[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 S[32][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 rightransportable[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 i,j;
    int temp;
	nonlineartransport(expansionrightext,rightext,expansiontable);
	operation(expansionrightext,Key,48);
	for(i=0;i<8;i++)
	{
		temp=S[expansionrightext[i*6]*2+expansionrightext[i*6+5]+i*4][expansionrightext[i*6+1]*8+expansionrightext[i*6+2]*4+expansionrightext[i*6+3]*2+expansionrightext[i*6+4]];
        j=3;
		for(;temp!=0;j--)
		{
			rightext[j+4*i]=temp%2;
			temp=temp/2;
		}
		for(;j>=0;j--)
		{
		  rightext[j+4*i]=0;
        }
	}
	transport(rightext,	rightransportable,32);
}
void cipher(int text[],int ip[],int IP[],int key[],int roundstable[],int choice )
{
	int i,j;
	int rightext[32];
	int Key[48];
    int keytransportable2[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};
    transport(text,ip,64);
    for(i=0;i<1;i++)
    {
        for(j=0;j<32;j++)
           rightext[j]=text[32+j];
    	if(choice)
	    {
  		  moveleft(key,28,roundstable[i]);
  		  moveleft(key+28,28,roundstable[i]);
  		  nonlineartransport(Key,key,keytransportable2); 	
    	}
    	else
    	{
    	   if(i>0)
    	   {
    	       moveright(key,28,roundstable[i]);
   		       moveright(key+28,28,roundstable[i]);	
   		       nonlineartransport(Key,key,keytransportable2);
 	       }
 	       else
 	           nonlineartransport(Key,key,keytransportable2);
        }	
   	    F(rightext,Key);
   	    operation(text,rightext,32);
        moveleft(text,64,32);
    }
    moveleft(text,64,32);
	transport(text,IP,64);	
}
void main()
{
	int i;
	int temp;
	int text[64]={1,1,0,0,1,0,1,0,
                  1,0,1,1,1,0,1,1,
                  1,0,1,0,1,1,0,0,
                  1,0,1,0,0,0,0,1,
                  1,1,0,1,0,0,0,0,
                  1,0,1,0,0,1,0,1,
                  1,1,0,0,0,0,0,1,
                  0,0,1,0,1,0,1,0};
    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 key[64]={0,0,1,1,0,0,1,0,
                 1,0,0,1,1,0,0,0,
                 0,0,1,0,0,0,1,1,
                 1,1,0,0,1,0,0,0,
                 0,1,1,0,1,0,1,0,
                 1,0,1,1,0,1,0,1,
                 0,1,1,0,0,1,0,1,
                 1,0,0,0,1,0,1,0};
    int keytransportable1[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};
    int roundstable[16]={1,1,2,2,
                         2,2,2,2,
                         1,2,2,2,
                         2,2,2,1};	
    int IP[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};
 printf("The Plaintext is:\n");
 output(text,64);
 printf("The Key is:\n");
 output(key,64);
 transport(key,keytransportable1,56);
 cipher(text,ip,IP,key,roundstable,1);
 printf("The Ciphertext is:\n");
 output(text,64);	
 cipher(text,ip,IP,key,roundstable,0);
 printf("The Plaintext is:\n");
 output(text,64);
}