NetBSD/crypto/dist/ssh/random.c

/*	$NetBSD: random.c,v 1.4 2001/02/14 04:46:58 itojun Exp $	*/

/*-
 * Copyright (c) 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the NetBSD
 *	Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: random.c,v 1.4 2001/02/14 04:46:58 itojun Exp $");
#endif

/*
 * Functions for stirring in additional noise into the
 * cryptographically strong PRNG.
 * the functions are not using "arc4" in any ways, they are placed here
 * to make porting easy.
 */

#include <sys/types.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>

#include <openssl/rand.h>

#include "includes.h"
#include "pathnames.h"
#include "random.h"
#include "log.h"

#define	BUFSIZE	32

static const char *rndfail = "random number device is mandatory.  see rnd(4).";

int
arc4random_check(void)
{
	int fd;

	fd = open(_PATH_URANDOM, O_RDONLY, 0666);
	if (fd < 0) {
		fatal(rndfail);
		/*NOTREACHED*/
	}
	close(fd);
	return 0;
}

void
arc4random_stir(void)
{
	u_char buf[BUFSIZE];
	ssize_t len;
	int fd;

	fd = open(_PATH_URANDOM, O_RDONLY, 0666);
	if (fd != -1) {
		len = read(fd, buf, sizeof(buf));
		if (len != -1)
			RAND_seed(buf, len);
		(void) close(fd);
		memset(buf, 0, sizeof(buf));
	} else {
		fatal(rndfail);
		/*NOTREACHED*/
	}
}

u_int32_t
arc4random(void)
{
	u_int32_t v;

	RAND_pseudo_bytes((u_char *)&v, sizeof(v));
	return v;
}