rsa.cpp

RSA对称、非对称加密解密算法

#include "stdafx.h"
#include "RSA.h"
#include<stdlib.h>
#include<time.h>


unsigned long gcd(unsigned long a,unsigned long b);

CRSA::CRSA(void)
{
}

CRSA::~CRSA(void)
{
}
/*
CBigInt CRSA::Gen_Prime(int len)
{
	srand((unsigned) time(NULL));
	unsigned long tmp,i;
	string temp;
	
		i=len/8;
		this->number.Clear0();
		this->number.m_nLength=i+1;
		for(;i>0;i--)
		{
			tmp=rand()%9973;
			tmp*=9973;
			tmp+=rand()%9973;
			this->number.m_ulvalue[i]=tmp;
		}
		while((tmp=rand()%9973)%2==0)
		{
		}
		tmp+=(rand()%9973)*9973;
		this->number.m_ulvalue[0]=tmp;
		while(1)
		{
			this->number.OutPutToStr(temp,10);
			if(this->prime_check(0))
			{
				cout<<temp<<"是素数"<<endl;
				return this->number;
			}
			cout<<temp<<"是合数"<<endl;
			this->number.Add(2);
		}
}
*/

CBigInt CRSA::Gen_Prime(int len)
{
	
	unsigned long temp,bigint_len=len/8+1,chengshu,isprime;
	string result,tmp_str1,tmp_str2;
	CBigInt b,gcdreturn,randtmp;
	int gen_prime=0,count;
	this->number.Rand(bigint_len);
	b.Seed(this->number);

	do
	{
		
		//this->number.OutPutToStr(result,10);
		
		do
		{
			b.Mov(b.Rand64());
			do
			{
				randtmp.Mov(b.Rand64());
				b.Mov(b.Mul(randtmp));

			}while(b.m_nLength<bigint_len);
		
		b.Mov(b.Mod(this->number));
		//b.OutPutToStr(tmp_str1,10);
		//cout<<result<<" "<<tmp_str1<<" ";
		}while(b.Cmp(0)==0);

		
		gcdreturn.Mov(b.Euc(this->number));

		//gcdreturn.OutPutToStr(tmp_str2,10);
		//cout<<tmp_str2<<endl;

		this->number.Mov(this->number.Div(gcdreturn));
		b.Mov(b.Div(gcdreturn));
		this->number.Mov(this->number.Add(b));
		count=0;
		gen_prime=0;
		while((isprime=this->prime_check(0))==0)
		{
			this->number.OutPutToStr(result,10);
			if(isprime)
			{
				//cout<<result<<"素数"<<endl;
				break;
			}
			else
			{
			//cout<<result<<"不是一个素数"<<endl;
			count++;
			if(count==20)
			{
				gen_prime=1;
				break;
			}
			}
			this->number.Mov(this->number.Add(b));
			//cout<<"+1"<<endl;
		}
	}
	while(gen_prime);
	
	//this->number.OutPutToStr(result,10);
	//cout<<result<<"是一个素数"<<endl;

	return this->number;

}

void CRSA::Gen_Public_Pravite(int len,CBigInt& public_key,CBigInt& private_key,CBigInt& n)
{
	CBigInt p,q,by_n,test,tmp;
	p.Mov(Gen_Prime(len/2));
	q.Mov(Gen_Prime(len/2));
	n.Mov(p.Mul(q));
	p.Mov(p.Sub(1));
	q.Mov(q.Sub(1));
	by_n.Mov(p.Mul(q));//by_n=(p-1)*(q-1)
	p.~CBigInt();q.~CBigInt();
	do
	{
	test.Rand(len);
	test.Mov(test.Mod(by_n));
	}
	while(test.Cmp(0)==0);
	tmp.Mov(test.Euc(by_n));
	public_key.Mov(test.Div(tmp));
	private_key.Euc(by_n,private_key);
}
void CRSA::Gen_Public_Pravite(int len,string& public_key,string& private_key,string& result_n)
{
	CBigInt p,q,n,by_n,public_k,private_k,test,tmp;
	p.Mov(Gen_Prime(len/2));
	q.Mov(Gen_Prime(len/2));
	n.Mov(p.Mul(q));
	p.Mov(p.Sub(1));
	q.Mov(q.Sub(1));
	by_n.Mov(p.Mul(q));//by_n=(p-1)*(q-1)
	p.~CBigInt();q.~CBigInt();
	do
	{
	test.Rand(len);
	test.Mov(test.Mod(by_n));
	}
	while(test.Cmp(0)==0);
	tmp.Mov(test.Euc(by_n));
	public_k.Mov(test.Div(tmp));
	public_k.Euc(by_n,private_k);
	public_k.OutPutToStr(public_key,10);
	private_k.OutPutToStr(private_key,10);
	n.OutPutToStr(result_n,10);
}
unsigned long gcd(unsigned long a,unsigned long b)
{
	if(b==0)
		return a;
	else
		return gcd(b,a%b);
}

string CRSA::Encryp(std::string mingwen, std::string public_key, std::string n)
{
	CBigInt m,e,mod,result;
	string temp;
	m.InPutFromStr(mingwen,10);
	e.InPutFromStr(public_key,10);
	mod.InPutFromStr(n,10);
	result.Mov(m.Mon(e,mod));
	result.OutPutToStr(temp,10);
	return temp;
}

CBigInt CRSA::Encryp(CBigInt mingwen, CBigInt public_key, CBigInt n)
{
	CBigInt result;
	result.Mov(mingwen.Mon(public_key,n));
	return result;
}

string CRSA::Decrypt(std::string miwen, std::string private_key, std::string n)
{
	CBigInt c,d,mod,result;
	string temp;
	c.InPutFromStr(miwen,10);
	d.InPutFromStr(private_key,10);
	mod.InPutFromStr(n,10);
	result.Mov(c.Mon(d,mod));
	result.OutPutToStr(temp,10);
	return temp;
}
CBigInt CRSA::Decrypt(CBigInt miwen, CBigInt private_key, CBigInt n)
{
	CBigInt result;
	result.Mov(miwen.Mon(private_key,n));
	return result;
}

string CRSA::Sign(std::string text, std::string private_key, std::string n)
{
	CBigInt c,d,mod,result;
	string temp;
	c.InPutFromStr(text,10);
	d.InPutFromStr(private_key,10);
	mod.InPutFromStr(n,10);
	result.Mov(c.Mon(d,mod));
	result.OutPutToStr(temp,10);
	return temp;
}

CBigInt CRSA::Sign(CBigInt text, CBigInt private_key, CBigInt n)
{
	CBigInt result;
	result.Mov(text.Mon(private_key,n));
	return result;
}

string CRSA::Sign_Check(std::string text, std::string public_key, std::string n)
{
	CBigInt m,e,mod,result;
	string temp;
	m.InPutFromStr(text,10);
	e.InPutFromStr(public_key,10);
	mod.InPutFromStr(n,10);
	result.Mov(m.Mon(e,mod));
	result.OutPutToStr(temp,10);
	return temp;
}

CBigInt CRSA::Sign_Check(CBigInt text, CBigInt public_key, CBigInt n)
{
	CBigInt result;
	result.Mov(text.Mon(public_key,n));
	return result;
}