1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1999 Mark Murray
5 * Copyright (c) 2014 Dag-Erling Smørgrav
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 <string.h>
36 #include <unistd.h>
37
38 #include "crypt.h"
39
40 /*
41 * List of supported crypt(3) formats.
42 *
43 * The default algorithm is the last entry in the list (second-to-last
44 * array element since the last is a sentinel). The reason for placing
45 * the default last rather than first is that DES needs to be at the
46 * bottom for the algorithm guessing logic in crypt(3) to work correctly,
47 * and it needs to be the default for backward compatibility.
48 */
49 static const struct crypt_format {
50 const char *name;
51 int (*func)(const char *, const char *, char *);
52 const char *magic;
53 } crypt_formats[] = {
54 { "md5", crypt_md5, "$1$" },
55 #ifdef HAS_BLOWFISH
56 { "blf", crypt_blowfish, "$2" },
57 #endif
58 { "nth", crypt_nthash, "$3$" },
59 { "sha256", crypt_sha256, "$5$" },
60 { "sha512", crypt_sha512, "$6$" },
61 #ifdef HAS_DES
62 { "des", crypt_des, "_" },
63 #endif
64
65 /* sentinel */
66 { NULL, NULL, NULL }
67 };
68
69 static const struct crypt_format *crypt_format =
70 &crypt_formats[(sizeof crypt_formats / sizeof *crypt_formats) - 2];
71
72 #define DES_SALT_ALPHABET \
73 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
74
75 /*
76 * Returns the name of the currently selected format.
77 */
78 const char *
crypt_get_format(void)79 crypt_get_format(void)
80 {
81
82 return (crypt_format->name);
83 }
84
85 /*
86 * Selects the format to use for subsequent crypt(3) invocations.
87 */
88 int
crypt_set_format(const char * format)89 crypt_set_format(const char *format)
90 {
91 const struct crypt_format *cf;
92
93 for (cf = crypt_formats; cf->name != NULL; ++cf) {
94 if (strcasecmp(cf->name, format) == 0) {
95 crypt_format = cf;
96 return (1);
97 }
98 }
99 return (0);
100 }
101
102 /*
103 * Hash the given password with the given salt. If the salt begins with a
104 * magic string (e.g. "$6$" for sha512), the corresponding format is used;
105 * otherwise, the currently selected format is used.
106 */
107 char *
crypt_r(const char * passwd,const char * salt,struct crypt_data * data)108 crypt_r(const char *passwd, const char *salt, struct crypt_data *data)
109 {
110 const struct crypt_format *cf;
111 int (*func)(const char *, const char *, char *);
112 #ifdef HAS_DES
113 int len;
114 #endif
115
116 for (cf = crypt_formats; cf->name != NULL; ++cf)
117 if (cf->magic != NULL && strstr(salt, cf->magic) == salt) {
118 func = cf->func;
119 goto match;
120 }
121 #ifdef HAS_DES
122 len = strlen(salt);
123 if ((len == 13 || len == 2) && strspn(salt, DES_SALT_ALPHABET) == len) {
124 func = crypt_des;
125 goto match;
126 }
127 #endif
128 func = crypt_format->func;
129 match:
130 if (func(passwd, salt, data->__buf) != 0)
131 return (NULL);
132 return (data->__buf);
133 }
134
135 char *
crypt(const char * passwd,const char * salt)136 crypt(const char *passwd, const char *salt)
137 {
138 static struct crypt_data data;
139
140 return (crypt_r(passwd, salt, &data));
141 }
142