genprim.c

来自「这个是RSA加密算法C源程序」· C语言 代码 · 共 72 行

/*******************************************************************************
*									       *
*	Copyright (c) Martin Nicolay,  22. Nov. 1988			       *
*									       *
*	Wenn diese (oder sinngemaess uebersetzte) Copyright-Angabe enthalten   *
*	bleibt, darf diese Source fuer jeden nichtkomerziellen Zweck weiter    *
*	verwendet werden.						       *
*									       *
*	[e-mail]					       *
*									       *
*******************************************************************************/

#include	<stdio.h>

#include	"arith.h"
#include	"prim.h"
#include	"nio.h"
#include	"rnd.h"

char *prog;

NUMBER a_three,a_four;

usage()
{
	fprintf(stderr,"usage: %s digits [probability]\n",prog);
	exit (1);
}

main( argc, argv )
char **argv;
{
	NUMBER prim;
	int len,i,prob;
	
	prog = argv[0];	
	
	if ( argc < 2 || 3 < argc )
		usage();
	
	len = atoi( argv[1] );
	if (argc > 2)
		prob = atoi( argv[2] );
	else
		prob = 10;

	a_add( &a_one, &a_two, &a_three );
	a_add( &a_two, &a_two, &a_four );

	init_rnd();
	
	do {
		gen_number( len, &prim );
	} while ( !prim.n_len );
	
	a_mult( &prim, &a_two, &prim );
	a_mult( &prim, &a_three, &prim );
	a_add( &prim, &a_one, &prim );
	
	for (i=1 ;; i++) {
		if (p_prim( &prim, prob ))
			break;
		if (i % 2)
			a_add( &prim, &a_four, &prim );
		else
			a_add( &prim, &a_two, &prim );
	}
	fprintf(stderr,"%d cycles\n",i);
	
	num_fput( &prim, stdout );
}