#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <time.h>

#include "BigInt.h"
#include "BIStack.h"
#include <iostream>

using namespace std;

bool primetest(BigInt b) {
	bool flag = false;
	flag = b.isProbablePrime(1000);
	if(!flag)
		return false;
	return true;
}

bool easynotprime(BigInt b) {
	if(b % BigInt::two() == BigInt::zero()) return false;
	BigInt three = BigInt::two() + BigInt::one();
	BigInt five = three + BigInt::two();
	BigInt seven = five + BigInt::two();
	BigInt eleven = seven + three + BigInt::one();
	if(b % three == BigInt::zero() || b % five == BigInt::zero() || b % seven == BigInt::zero() || b % eleven == BigInt::zero())
		return false;
	else
		return true;
}

int main() {
	FILE *f, *g;
	f = fopen("open.txt", "w");
	g = fopen("close.txt", "w");
	BigInt b = -BigInt::one();
	b.generateRandom(256);
	if(b < BigInt::zero())
		b = BigInt::zero() - b;
	while(!primetest(b)) {
		b += BigInt::one();
		while(!easynotprime(b))
			b += BigInt::one();
	}

	BigInt c = -BigInt::one();
	c.generateRandom(256);
	if(c < BigInt::zero())
		c = BigInt::zero() - c;
	while(!primetest(c)) {
		c += BigInt::one();
		while(!easynotprime(c))
			c += BigInt::one();
	}

	BigInt n = b * c;
	BigInt fn = (b - 1) * (c - 1), e;
	char line1[513];
	fn.toString(line1, 513);

	e.generateRandom(20);
	if(e < BigInt::zero())
		e = BigInt::zero() - e;
	while(BigInt::gcd(fn, e) != BigInt::one()) {
		e += BigInt::one();
	}
	char line3[512];
	e.toString(line3, 512);

	BigInt d, p, a;
	a = BigInt::extEucl(e, fn, d, p, a);
	char line4[512];
	if(d < BigInt::zero())
		d += fn;
	d.toString(line4, 512);

	fprintf(f, "Открытый ключ\n%s\n%s\n", line1, line3);
	fprintf(g, "Закрытый ключ\n%s\n%s\n", line1, line4);
	fclose(f);
	fclose(g);
	return 0;
}