3a0c68edfd
The algorithm used is essentially PBKDF1 from RFC 2898 but using hmac_sha1 rather than SHA1 directly (suggested by smb@research.att.com). * The format of the encrypted password is: * $<tag>$<iterations>$<salt>$<digest> * * where: * <tag> is "sha1" * <iterations> is an unsigned int identifying how many rounds * have been applied to <digest>. The number * should vary slightly for each password to make * it harder to generate a dictionary of * pre-computed hashes. See crypt_sha1_iterations. * <salt> up to 64 bytes of random data, 8 bytes is * currently considered more than enough. * <digest> the hashed password. hmac.c implementes HMAC as defined in RFC 2104 and includes a unit test for both hmac_sha1 and hmac_sha1 using a selection of the Known Answer Tests from RFC 2202. It is worth noting that to be FIPS compliant the hmac key (password) should be 10-20 chars.
145 lines
4.3 KiB
C
145 lines
4.3 KiB
C
/* $NetBSD: pwd_gensalt.c,v 1.11 2004/07/02 00:05:23 sjg Exp $ */
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/*
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* Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by Niels Provos.
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* 4. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* from OpenBSD: pwd_gensalt.c,v 1.9 1998/07/05 21:08:32 provos Exp
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*/
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#include <sys/cdefs.h>
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#ifndef lint
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__RCSID("$NetBSD: pwd_gensalt.c,v 1.11 2004/07/02 00:05:23 sjg Exp $");
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#endif /* not lint */
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#include <sys/syslimits.h>
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#include <sys/types.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <err.h>
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#include <grp.h>
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#include <pwd.h>
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#include <util.h>
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#include <time.h>
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#include <pwd.h>
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#include <crypt.h>
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#include "extern.h"
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int
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pwd_gensalt(char *salt, int max, struct passwd *pwd, char type)
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{
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char option[LINE_MAX], *next, *now, *cipher, grpkey[LINE_MAX];
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int rounds;
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struct group *grp;
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*salt = '\0';
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switch (type) {
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case 'y':
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cipher = "ypcipher";
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break;
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case 'l':
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default:
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cipher = "localcipher";
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break;
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}
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pw_getconf(option, sizeof(option), pwd->pw_name, cipher);
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/* Try to find an entry for the group */
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if (*option == 0) {
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if ((grp = getgrgid(pwd->pw_gid)) != NULL) {
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snprintf(grpkey, sizeof(grpkey), ":%s", grp->gr_name);
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pw_getconf(option, sizeof(option), grpkey, cipher);
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}
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if (*option == 0)
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pw_getconf(option, sizeof(option), "default", cipher);
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}
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next = option;
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now = strsep(&next, ",");
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if (strcmp(now, "old") == 0) {
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if (max < 3)
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return (0);
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__crypt_to64(&salt[0], arc4random(), 2);
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salt[2] = '\0';
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} else if (strcmp(now, "newsalt") == 0) {
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rounds = atol(next);
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if (max < 10)
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return (0);
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/* Check rounds, 24 bit is max */
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if (rounds < 7250)
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rounds = 7250;
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else if (rounds > 0xffffff)
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rounds = 0xffffff;
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salt[0] = _PASSWORD_EFMT1;
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__crypt_to64(&salt[1], (u_int32_t)rounds, 4);
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__crypt_to64(&salt[5], arc4random(), 4);
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salt[9] = '\0';
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} else if (strcmp(now, "md5") == 0) {
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if (max < 13) /* $1$8salt$\0 */
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return (0);
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salt[0] = _PASSWORD_NONDES;
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salt[1] = '1';
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salt[2] = '$';
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__crypt_to64(&salt[3], arc4random(), 4);
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__crypt_to64(&salt[7], arc4random(), 4);
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salt[11] = '$';
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salt[12] = '\0';
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} else if (strcmp(now, "sha1") == 0) {
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int n;
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rounds = atoi(next); /* a hint only, 0 is ok */
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n = snprintf(salt, max, "%s%u$", SHA1_MAGIC,
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__crypt_sha1_iterations(rounds));
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/*
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* The salt can be up to 64 bytes, but 8
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* is considered enough for now.
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*/
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if (n + 9 >= max)
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return 0;
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__crypt_to64(&salt[n], arc4random(), 4);
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__crypt_to64(&salt[n + 4], arc4random(), 4);
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salt[n + 8] = '$';
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salt[n + 9] = '\0';
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} else if (strcmp(now, "blowfish") == 0) {
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rounds = atoi(next);
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if (rounds < 4)
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rounds = 4;
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strlcpy(salt, bcrypt_gensalt(rounds), max);
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} else {
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strlcpy(salt, ":", max);
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warnx("Unknown option %s.", now);
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}
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return (1);
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}
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