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