2.cpp

SDES 的加密

#include<iostream.h>
void cout1(int *a,int b)
{
	for(int i = 0 ;i<b;i++)
	{
		cout<<a[i];
		if(i !=b-1) 
			cout<<" ";
		else cout<<endl;
	}
}
int * jiao1 (int * a ,int i = 3)//二进制进行加1的运算
{
	a[i] = a[i]++;
	if(a[i] ==2 && i>=0) 
	{
		a[i] = 0;
		jiao1(a,--i);
	}
	 return a;
}
int * XOR(int * a, int * b)//  四位二进制的数进行xor 运算
{
	for(int i = 0; i<4 ; i++)
	{
		if( a[i] == b[i] )
			a[i] =  0;
		else 
			a[i] = 1;
	}
	return a;
}
int * s ( int * s,int *s0) // s0 是s盒子的值的变化字  s是输入的4bit的数
{                         //  注意：s 是4位的，返回的结果是2位，所以，就只有2 3位有效
	int a = s[0]*2 + s[1];
	int b = s[2]*2 + s[3];
	s[2]= s[3]=0;
	for(int i = 0; i<s0[a*4+b]; i++)
		jiao1(s);
	return s;
}

	
int * fk(int * sw , int * k2)
{
	int E_P [] = {4,1,2,3,2,3,4,1} ;
	int s0  [] = {1,0,3,2,3,2,1,0,0,2,1,3,3,1,3,2};
	int s1  [] = {0,1,2,3,2,0,1,3,3,0,1,0,2,1,0,3};
	int p4  [] = {2,4,3,1};
	int e_phou [8];
	for(int i = 0;i<8;i++)
		e_phou[i] = sw[E_P[i]+4-1];
	cout<<1<<endl;
	cout1(e_phou,8);
	////////////////////////////////////////////////////////
	XOR(e_phou,k2);
	XOR(e_phou+4,k2+4);
	cout<<2<<endl;
	cout1(e_phou,8);
//////////////////////////////////////////////////////////
	s(e_phou,s0);
	cout1(e_phou+2,2);
	s(e_phou+4,s1);
		cout1(e_phou+6,2);

	e_phou[4] = e_phou[2];
	e_phou[5] = e_phou[3];// 4 5   6 7位为s0 和s1后的四个数
	cout<<3<<endl;
		cout1(e_phou+4,4);
/////////////////////////////////////////////////////////////
	for(i = 0;i<4;i++)
		e_phou[i] = e_phou[p4[i]+4-1];
	 // p4 后的四个数 0 1 2 3 中
	cout<<4<<endl;
		cout1(e_phou,8);
		////////////////////////////////
	XOR(sw ,e_phou);
	cout<<5<<endl;
		cout1(sw,8);
	return sw;
}

//下面的函数是对求密匙的运算k1 k2 
 int *Ls_1(int * a)// 循环左移一位  ， 是5为数的
{
	int temp = a[0];
	for(int i =0;i<4;i++)
		a[i] = a[i+1];
	a[4]  =  temp;
	return a;
}
 void main ()
 {
//	 	int s0  [] = {1,0,3,2,3,2,1,0,0,2,1,3,3,1,3,2};
//	int s1  [] = {0,1,2,3,2,0,1,3,3,0,1,0,2,1,0,3};
	 int  sw[8] = { 0,0,0,1,0,0,1,1};
	 int  mishi[8] = {0,1,0,1,1,1,1,1};
	 fk(sw ,mishi);
	 

/*	 s(a,s0);
	 cout1(a+2,2);
	 s(b,s1);
	 int a[4] ={0,1};
	 	 int b[4] ={0,1};
	 cout1(b+2,2);
*/	 




 }