Subversion Repositories planix.SVN

#include "os.h"

#include <mp.h>

#include <libsec.h>

//  generate a probable prime.  accuracy is the miller-rabin interations

void

genprime(mpint *p, int n, int accuracy)

{

	mpdigit x;

	// generate n random bits with high and low bits set

	mpbits(p, n);

	genrandom((uchar*)p->p, (n+7)/8);

	p->top = (n+Dbits-1)/Dbits;

	x = 1;

	x <<= ((n-1)%Dbits);

	p->p[p->top-1] &= (x-1);

	p->p[p->top-1] |= x;

	p->p[0] |= 1;

	// keep icrementing till it looks prime

	for(;;){

		if(probably_prime(p, accuracy))

			break;

		mpadd(p, mptwo, p);

	}

}