www.gusucode.com > VC++ RAS加密解密算法的实现-源码程序 > VC++ RAS加密解密算法的实现-源码程序/code/ras.cpp

    #include<iostream.h>
#include<stdio.h>
#include<math.h>
int pf_c(int m,int k);
int pf(int m1,int n1);
int gcd(int f);
int r;
int h;
//Download by http://www.NewXing.com
void main()
{   int a,b,c,d,d1,a1,b1,c1;
    cout<<"请输入你选择的2个大素数!"<<endl;
	cin>>a1;
	cin>>b1;
	r=a1*b1;
    c=(a1-1)*(b1-1);
	c1=gcd(c);
	cout<<"公开钥为:"<<c1<<endl;
    cout<<"请选择你要的操作:1.加密  2.解密"<<endl;
	cin>>a;
	switch(a){
	case 1: cout<<"请输入明文:"<<endl;
		    cin>>b;
		    cout<<"密文为:"<<pf_c(b,c1)<<endl;
			break;
	case 2: cout<<"请输入密文:"<<endl;
		    cin>>d;
	 	    d1=pf(c,c1);
			cout<<"私密钥为:"<<d1<<endl;
		    cout<<"明文为:"<<pf_c(d,d1)<<endl;
			break;
	}
}
int pf_c(int m,int k)
{
	int a,i1,a1,b[50],c1,c;
	c=0;c1=1;i1=0;
	do{
		a=k/2;
		a1=k%2;
		b[i1]=a1;
		k=a;
		i1++;
	}while(a>0);
	i1--;
	for(int i=i1;i>=0;i--)
	{
		c=2*c;
		c1=(c1*c1)%r;
		if(b[i]==1)
		{
			c=c+1;
			c1=(c1*m)%r;
		}
	}
	return c1;
}
int pf(int m1,int n1)
{
	int x1=1,x2=0,x3;
    int y1=0,y2=1,y3;
	x3=m1;
	y3=n1;
	int d;
	for(int i=0; ;i++)
	{
	   int q=x3/y3;
	   int t1=x1-q*y1;
	   int t2=x2-q*y2;
	   int t3=x3-q*y3;
	   x1=y1;
	   x2=y2;
	   x3=y3;
	   y1=t1;
	   y2=t2;
	   y3=t3;
	   if(y3==1)
	   {
		   if(y2<0) d=m1+y2;
		   else d=y2;
		   break;
	   }
	}
	return d;
}
int gcd(int f)
{   
	int x1=1,x2=0,x3;
    int y1=0,y2=1,y3;
	for(int i1=2;i1<f;i1++)
	{
		x3=f;
		y3=i1;
        int q=x3/y3;
	    int t1=x1-q*y1;
	    int t2=x2-q*y2;
	    int t3=x3-q*y3;
	    x1=y1;
	    x2=y2;
	    x3=y3;
	    y1=t1;
	    y2=t2;
	    y3=t3;
		if(y3==1)
		{
			return i1;
			break;
		}
	}
}