1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
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/types.h>
31
32 #include <string.h>
33 #include <unistd.h>
34
35 #include "crypt.h"
36
37 /*
38 * List of supported crypt(3) formats.
39 *
40 * The default algorithm is the last entry in the list (second-to-last
41 * array element since the last is a sentinel). The reason for placing
42 * the default last rather than first is that DES needs to be at the
43 * bottom for the algorithm guessing logic in crypt(3) to work correctly,
44 * and it needs to be the default for backward compatibility.
45 */
46 static const struct crypt_format {
47 const char *name;
48 int (*func)(const char *, const char *, char *);
49 const char *magic;
50 } crypt_formats[] = {
51 { "md5", crypt_md5, "$1$" },
52 #ifdef HAS_BLOWFISH
53 { "blf", crypt_blowfish, "$2" },
54 #endif
55 { "nth", crypt_nthash, "$3$" },
56 { "sha256", crypt_sha256, "$5$" },
57 { "sha512", crypt_sha512, "$6$" },
58 #ifdef HAS_DES
59 { "des", crypt_des, "_" },
60 #endif
61
62 /* sentinel */
63 { NULL, NULL, NULL }
64 };
65
66 static const struct crypt_format *crypt_format =
67 &crypt_formats[(sizeof crypt_formats / sizeof *crypt_formats) - 2];
68
69 #define DES_SALT_ALPHABET \
70 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
71
72 /*
73 * Returns the name of the currently selected format.
74 */
75 const char *
crypt_get_format(void)76 crypt_get_format(void)
77 {
78
79 return (crypt_format->name);
80 }
81
82 /*
83 * Selects the format to use for subsequent crypt(3) invocations.
84 */
85 int
crypt_set_format(const char * format)86 crypt_set_format(const char *format)
87 {
88 const struct crypt_format *cf;
89
90 for (cf = crypt_formats; cf->name != NULL; ++cf) {
91 if (strcasecmp(cf->name, format) == 0) {
92 crypt_format = cf;
93 return (1);
94 }
95 }
96 return (0);
97 }
98
99 /*
100 * Hash the given password with the given salt. If the salt begins with a
101 * magic string (e.g. "$6$" for sha512), the corresponding format is used;
102 * otherwise, the currently selected format is used.
103 */
104 char *
crypt_r(const char * passwd,const char * salt,struct crypt_data * data)105 crypt_r(const char *passwd, const char *salt, struct crypt_data *data)
106 {
107 const struct crypt_format *cf;
108 int (*func)(const char *, const char *, char *);
109 #ifdef HAS_DES
110 int len;
111 #endif
112
113 for (cf = crypt_formats; cf->name != NULL; ++cf)
114 if (cf->magic != NULL && strstr(salt, cf->magic) == salt) {
115 func = cf->func;
116 goto match;
117 }
118 #ifdef HAS_DES
119 len = strlen(salt);
120 if ((len == 13 || len == 2) && strspn(salt, DES_SALT_ALPHABET) == len) {
121 func = crypt_des;
122 goto match;
123 }
124 #endif
125 func = crypt_format->func;
126 match:
127 if (func(passwd, salt, data->__buf) != 0)
128 return (NULL);
129 return (data->__buf);
130 }
131
132 char *
crypt(const char * passwd,const char * salt)133 crypt(const char *passwd, const char *salt)
134 {
135 static struct crypt_data data;
136
137 return (crypt_r(passwd, salt, &data));
138 }
139