NetBSD/lib/libcrypt/pw_gensalt.c

186 lines
4.5 KiB
C

/* $NetBSD: pw_gensalt.c,v 1.7 2009/01/18 12:15:27 lukem Exp $ */
/*
* Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
* All rights reserved.
*
* 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 Niels Provos.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*
* from OpenBSD: pwd_gensalt.c,v 1.9 1998/07/05 21:08:32 provos Exp
*/
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: pw_gensalt.c,v 1.7 2009/01/18 12:15:27 lukem Exp $");
#endif /* not lint */
#include <sys/syslimits.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <err.h>
#include <grp.h>
#include <pwd.h>
#include <util.h>
#include <time.h>
#include <errno.h>
#include "crypt.h"
static const struct pw_salt {
const char *name;
int (*gensalt)(char *, size_t, const char *);
} salts[] = {
{ "old", __gensalt_old },
{ "new", __gensalt_new },
{ "newsalt", __gensalt_new },
{ "md5", __gensalt_md5 },
{ "sha1", __gensalt_sha1 },
{ "blowfish", __gensalt_blowfish },
{ NULL, NULL }
};
static int
getnum(const char *str, size_t *num)
{
char *ep;
unsigned long rv;
if (str == NULL) {
*num = 0;
return 0;
}
rv = strtoul(str, &ep, 0);
if (str == ep || *ep) {
errno = EINVAL;
return -1;
}
if (errno == ERANGE && rv == ULONG_MAX)
return -1;
*num = (size_t)rv;
return 0;
}
int
/*ARGSUSED2*/
__gensalt_old(char *salt, size_t saltsiz, const char *option)
{
if (saltsiz < 3) {
errno = ENOSPC;
return -1;
}
__crypt_to64(&salt[0], arc4random(), 2);
salt[2] = '\0';
return 0;
}
int
/*ARGSUSED2*/
__gensalt_new(char *salt, size_t saltsiz, const char* option)
{
size_t nrounds;
if (saltsiz < 10) {
errno = ENOSPC;
return -1;
}
if (getnum(option, &nrounds) == -1)
return -1;
/* Check rounds, 24 bit is max */
if (nrounds < 7250)
nrounds = 7250;
else if (nrounds > 0xffffff)
nrounds = 0xffffff;
salt[0] = _PASSWORD_EFMT1;
__crypt_to64(&salt[1], (uint32_t)nrounds, 4);
__crypt_to64(&salt[5], arc4random(), 4);
salt[9] = '\0';
return 0;
}
int
/*ARGSUSED2*/
__gensalt_md5(char *salt, size_t saltsiz, const char *option)
{
if (saltsiz < 13) { /* $1$8salt$\0 */
errno = ENOSPC;
return -1;
}
salt[0] = _PASSWORD_NONDES;
salt[1] = '1';
salt[2] = '$';
__crypt_to64(&salt[3], arc4random(), 4);
__crypt_to64(&salt[7], arc4random(), 4);
salt[11] = '$';
salt[12] = '\0';
return 0;
}
int
__gensalt_sha1(char *salt, size_t saltsiz, const char *option)
{
int n;
size_t nrounds;
if (getnum(option, &nrounds) == -1)
return -1;
n = snprintf(salt, saltsiz, "%s%u$", SHA1_MAGIC,
__crypt_sha1_iterations(nrounds));
/*
* The salt can be up to 64 bytes, but 8
* is considered enough for now.
*/
if ((size_t)n + 9 >= saltsiz)
return 0;
__crypt_to64(&salt[n], arc4random(), 4);
__crypt_to64(&salt[n + 4], arc4random(), 4);
salt[n + 8] = '$';
salt[n + 9] = '\0';
return 0;
}
int
pw_gensalt(char *salt, size_t saltlen, const char *type, const char *option)
{
const struct pw_salt *sp;
for (sp = salts; sp->name; sp++)
if (strcmp(sp->name, type) == 0)
return (*sp->gensalt)(salt, saltlen, option);
errno = EINVAL;
return -1;
}