1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1999 Mark Murray
5 * Copyright (c) 2014 Dag-Erling Sm��rgrav
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY MARK MURRAY AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL MARK MURRAY OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD$");
32
33#include <sys/types.h>
34
35#include <libutil.h>
36#include <string.h>
37#include <unistd.h>
38
39#include "crypt.h"
40
41/*
42 * List of supported crypt(3) formats.
43 *
44 * The default algorithm is the last entry in the list (second-to-last
45 * array element since the last is a sentinel).  The reason for placing
46 * the default last rather than first is that DES needs to be at the
47 * bottom for the algorithm guessing logic in crypt(3) to work correctly,
48 * and it needs to be the default for backward compatibility.
49 */
50static const struct crypt_format {
51	const char *name;
52	int (*func)(const char *, const char *, char *);
53	const char *magic;
54} crypt_formats[] = {
55	{ "md5",	crypt_md5,		"$1$"	},
56#ifdef HAS_BLOWFISH
57	{ "blf",	crypt_blowfish,		"$2"	},
58#endif
59	{ "nth",	crypt_nthash,		"$3$"	},
60	{ "sha256",	crypt_sha256,		"$5$"	},
61	{ "sha512",	crypt_sha512,		"$6$"	},
62#ifdef HAS_DES
63	{ "des",	crypt_des,		"_"	},
64#endif
65
66	/* sentinel */
67	{ NULL,		NULL,			NULL	}
68};
69
70static const struct crypt_format *crypt_format =
71    &crypt_formats[(sizeof crypt_formats / sizeof *crypt_formats) - 2];
72
73#define DES_SALT_ALPHABET \
74	"./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
75
76/*
77 * Returns the name of the currently selected format.
78 */
79const char *
80crypt_get_format(void)
81{
82
83	return (crypt_format->name);
84}
85
86/*
87 * Selects the format to use for subsequent crypt(3) invocations.
88 */
89int
90crypt_set_format(const char *format)
91{
92	const struct crypt_format *cf;
93
94	for (cf = crypt_formats; cf->name != NULL; ++cf) {
95		if (strcasecmp(cf->name, format) == 0) {
96			crypt_format = cf;
97			return (1);
98		}
99	}
100	return (0);
101}
102
103/*
104 * Hash the given password with the given salt.  If the salt begins with a
105 * magic string (e.g. "$6$" for sha512), the corresponding format is used;
106 * otherwise, the currently selected format is used.
107 */
108char *
109crypt_r(const char *passwd, const char *salt, struct crypt_data *data)
110{
111	const struct crypt_format *cf;
112	int (*func)(const char *, const char *, char *);
113#ifdef HAS_DES
114	int len;
115#endif
116
117	for (cf = crypt_formats; cf->name != NULL; ++cf)
118		if (cf->magic != NULL && strstr(salt, cf->magic) == salt) {
119			func = cf->func;
120			goto match;
121		}
122#ifdef HAS_DES
123	len = strlen(salt);
124	if ((len == 13 || len == 2) && strspn(salt, DES_SALT_ALPHABET) == len) {
125		func = crypt_des;
126		goto match;
127	}
128#endif
129	func = crypt_format->func;
130match:
131	if (func(passwd, salt, data->__buf) != 0)
132		return (NULL);
133	return (data->__buf);
134}
135
136char *
137crypt(const char *passwd, const char *salt)
138{
139	static struct crypt_data data;
140
141	return (crypt_r(passwd, salt, &data));
142}
143