des.c

用C语言编译的DES加解密程序 望大家指教

		ip[i+32]=*(*(l+a)+i);
	}
	printf("\n");
	printf("\n");
	printf("     IP 逆");
	for(i=0;i<=63;i++)
	{
		*(ip_1+i)=ip[IP_1[i]-1];
		if(i%8==0) printf("\n");
		printf("%2d",*(ip_1+i)); 
	}
	printf("\n");
}
/*************************************************************************************************/
void miwen(int *ip_1)
{
	int i,j,a,c,b,x[8];
	for(i=0;i<=7;i++)
	{
		a=i*8;
		x[i]=0;
		for(j=7;j>=0;j--)
		{
			c=*(ip_1+a);
			b=pow(2,j);
			x[i]=x[i]+b*c;
			
			a++;
		}
	}
	for(i=0;i<=7;i++)
	{
		a=x[i]%127;
		printf("%c",(char)(a));
	}
	printf("\n");
}
/*************************************************************************************************/
void main()
{
	void erjinzhi(char z[8],int *q);
	void PC_1_bianhuan(int *Key,int *pc_1);
	void CD(int *pc_1,int (*c)[28],int (*d)[28]);
	void LS_yiwei(int (*p)[28],int i);
	void CD_hebin(int *pc_1,int (*c)[28],int (*d)[28],int i);
	void PC_2_bianhuan(int (*kout)[48],int *pc_1,int a);
	void IP_change(int *ip,int *Data);
	void L__R(int (*l)[32],int (*r)[32],int i);
	void E_change(int *r_change,int (*r)[32],int a);
	void yihuo1(int *r_change,int (*kout)[48],int a);
	void S_replace(int *r_change,int *s1);
	void P_replace(int *p,int *s1);
	void yihuo2(int (*l)[32],int (*r)[32],int *p,int a);
	void IP2(int (*l)[32],int (*r)[32],int *ip_1,int i);
	void miwen(int *ip_1);
	void yihuo3(int *r_change,int (*kout)[48],int a);

	char mingwen[8],key_Origion[8];
	int i,R_change[48],S1[32],P[32],DATA[64],KEY[64],PC_1[56],IP[64],IP_1[64],
		C[17][28],D[17][28],Left[17][32],Right[17][32],key_out[16][48];
	int *r_change,*s1,*p,*Data,*Key,*pc_1,*ip,*ip_1,
		(*c)[28],(*d)[28],(*l)[32],(*r)[32],(*kout)[48];		
/******************************************************************************/
	c=C;
	p=P;
	ip_1=IP_1;
	d=D;
	l=Left;
	r=Right;
	kout=key_out;
	Key=KEY;
	Data=DATA;
	pc_1=PC_1;
	r_change=R_change;
	s1=S1;
	ip=IP;

	do
	{
		printf("请输入8位明文字符");
		scanf("%s",mingwen);
		i=strlen(mingwen);
	}while(i!=8);
	erjinzhi(mingwen,Data);           // 明文二进制转换
	
	do
	{
		printf("请输入8位密钥字符");
		scanf("%s",key_Origion);
		i=strlen(key_Origion);
	}while(i!=8);
	printf("\n");
	erjinzhi(key_Origion,Key);        // 密文二进制
	//jiami
	IP_change(ip,Data);               // 明文IP变换
	L0_R0(ip,l,r);                    // LO RO
	PC_1_bianhuan(Key,pc_1);          // PC_1
	CD(pc_1,c,d);                     // C0 D0
	for(i=1;i<=16;i++)
	{
		LS_yiwei(c,i);
		LS_yiwei(d,i);
		CD_hebin(pc_1,c,d,i);
		PC_2_bianhuan(kout,pc_1,i);

		L__R(l,r,i);
		E_change(r_change,r,i);
		yihuo1(r_change,kout,i);            // R与K 的异或
		S_replace(r_change,s1);             // S-盒替换
		P_replace(p,s1);                    // P-盒替换
        yihuo2(l,r,p,i);                    // L与P替换后的数组异或
	}
	IP2(l,r,ip_1,i-1);
	miwen(ip_1);
	//jiemi
	IP_change(ip,ip_1);                   // 密文IP变换
	L0_R0(ip,l,r);                        // LO RO
	for(i=1;i<=16;i++)
	{
		L__R(l,r,i);
		E_change(r_change,r,i);
		yihuo3(r_change,kout,i);            // R与K 的异或
		S_replace(r_change,s1);             // S-盒替换
		P_replace(p,s1);                    // P-盒替换
		yihuo2(l,r,p,i);                    // L与P替换后的数组异或
	}
	IP2(l,r,ip_1,i-1);
	miwen(ip_1);
	return;
}

/***********************************    S 替 换  **********************************************************/
void S_replace(int *r_change,int *s1)
{
	int i,b,j,x,a,
		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,
				   15,12,8,2,4,9,1,7,5,11,3,15,10,0,6,13},
		
		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},
		
	    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},
		
		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},
		
		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},
		
		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},
		
		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},
		
		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};
//	printf(" i  j  x");
	for(b=0;b<=7;b++)
	{
		switch(b)
		{
		case 0:
			i=*(r_change+0)*2+*(r_change+5)*1+1;
			j=*(r_change+1)*8+*(r_change+2)*4+*(r_change+3)*2+*(r_change+4)+1;
			x=S1[i-1][j-1];
//			printf("  %2d  %2d  %2d\n",i,j,x);
			for(a=3;a>=0;a--)
			{
				*(s1+a)=x%2;
				x=x/2;
			}
			break;
		case 1:
			i=*(r_change+6)*2+*(r_change+11)*1+1;
			j=*(r_change+7)*8+*(r_change+8)*4+*(r_change+9)*2+*(r_change+10)+1;
			x=S2[i-1][j-1];
//			printf("  %2d  %2d  %2d\n",i,j,x);
			for(a=7;a>=4;a--)
			{
				*(s1+a)=x%2;
				x=x/2;
			}
			break;
		case 2:
			i=*(r_change+12)*2+*(r_change+17)*1+1;
			j=*(r_change+13)*8+*(r_change+14)*4+*(r_change+15)*2+*(r_change+16)+1;
			x=S3[i-1][j-1];
//			printf("  %2d  %2d  %2d\n",i,j,x);
			for(a=11;a>=8;a--)
			{
				*(s1+a)=x%2;
				x=x/2;
			}
			break;
		case 3:
			i=*(r_change+18)*2+*(r_change+23)*1+1;
			j=*(r_change+19)*8+*(r_change+20)*4+*(r_change+21)*2+*(r_change+22)+1;
			x=S4[i-1][j-1];
//			printf("  %2d  %2d  %2d\n",i,j,x);
			for(a=15;a>=12;a--)
			{
				*(s1+a)=x%2;
				x=x/2;
			}
			break;
		case 4:
			i=*(r_change+24)*2+*(r_change+29)*1+1;
			j=*(r_change+25)*8+*(r_change+26)*4+*(r_change+27)*2+*(r_change+28)+1;
			x=S5[i-1][j-1];
//			printf("  %2d  %2d  %2d\n",i,j,x);
			for(a=19;a>=16;a--)
			{
				*(s1+a)=x%2;
				x=x/2;
			}
			break;
		case 5:
			i=*(r_change+30)*2+*(r_change+35)*1+1;
			j=*(r_change+31)*8+*(r_change+32)*4+*(r_change+33)*2+*(r_change+34)+1;
			x=S6[i-1][j-1];
//			printf("  %2d  %2d  %2d\n",i,j,x);
			for(a=23;a>=20;a--)
			{
				*(s1+a)=x%2;
				x=x/2;
			}
			break;
		case 6:
			i=*(r_change+36)*2+*(r_change+41)*1+1;
			j=*(r_change+37)*8+*(r_change+38)*4+*(r_change+39)*2+*(r_change+40)+1;
			x=S7[i-1][j-1];
//			printf("  %2d  %2d  %2d\n",i,j,x);
			for(a=27;a>=24;a--)
			{
				*(s1+a)=x%2;
				x=x/2;
			}
			break;
		case 7:
			i=*(r_change+42)*2+*(r_change+47)*1+1;
			j=*(r_change+43)*8+*(r_change+44)*4+*(r_change+45)*2+*(r_change+46)+1;
			x=S8[i-1][j-1];
//			printf("  %2d  %2d  %2d\n",i,j,x);
			for(a=31;a>=28;a--)
			{
				*(s1+a)=x%2;
				x=x/2;
			}
			break;
		}
	}
/*	printf("S变换\n");
	for(i=0;i<=31;i++)                        //输出 S变换
	{
		if(i%4==0) printf("\n");
		printf("%2d",*(s1+i));
	}
	printf("\n");*/
}