crypt.c revision 265880 
1/*-
2 * Copyright (c) 1999 Mark Murray
3 * Copyright (c) 2014 Dag-Erling Sm��rgrav
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY MARK MURRAY AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL MARK MURRAY OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: stable/9/lib/libcrypt/crypt.c 265880 2014-05-11 15:03:24Z des $");
30
31#include <sys/types.h>
32
33#include <libutil.h>
34#include <string.h>
35#include <unistd.h>
36
37#include "crypt.h"
38
39/*
40 * List of supported crypt(3) formats.  The first element in the list will
41 * be the default.
42 */
43static const struct crypt_format {
44	const char *const name;
45	char *(*const func)(const char *, const char *);
46	const char *const magic;
47} crypt_formats[] = {
48	/* default format */
49	{ "sha512",	crypt_sha512,		"$6$"	},
50
51	/* other supported formats */
52	{ "md5",	crypt_md5,		"$1$"	},
53#ifdef HAS_BLOWFISH
54	{ "blf",	crypt_blowfish,		"$2"	},
55#endif
56	{ "nth",	crypt_nthash,		"$3$"	},
57	{ "sha256",	crypt_sha256,		"$5$"	},
58#ifdef HAS_DES
59	{ "des",	crypt_des,		"_"	},
60#endif
61
62	/* sentinel */
63	{ NULL,		NULL,			NULL	}
64};
65
66static const struct crypt_format *crypt_format = &crypt_formats[0];
67
68#define DES_SALT_ALPHABET \
69	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
70
71/*
72 * Returns the name of the currently selected format.
73 */
74const char *
75crypt_get_format(void)
76{
77
78	return (crypt_format->name);
79}
80
81/*
82 * Selects the format to use for subsequent crypt(3) invocations.
83 */
84int
85crypt_set_format(const char *format)
86{
87	const struct crypt_format *cf;
88
89	for (cf = crypt_formats; cf->name != NULL; ++cf) {
90		if (strcasecmp(cf->name, format) == 0) {
91			crypt_format = cf;
92			return (1);
93		}
94	}
95	return (0);
96}
97
98/*
99 * Hash the given password with the given salt.  If the salt begins with a
100 * magic string (e.g. "$6$" for sha512), the corresponding format is used;
101 * otherwise, the currently selected format is used.
102 */
103char *
104crypt(const char *passwd, const char *salt)
105{
106	const struct crypt_format *cf;
107
108	for (cf = crypt_formats; cf->name != NULL; ++cf)
109		if (cf->magic != NULL && strstr(salt, cf->magic) == salt)
110			return (cf->func(passwd, salt));
111#ifdef HAS_DES
112	if (strlen(salt) == 13 && strspn(salt, DES_SALT_ALPHABET) == 13)
113		return (crypt_des(passwd, salt));
114#endif
115	return (crypt_format->func(passwd, salt));
116}
117