1 /* $OpenBSD: groupaccess.c,v 1.15 2015/01/20 23:14:00 deraadt Exp $ */
2 /*
3 * Copyright (c) 2001 Kevin Steves. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26 #include "includes.h"
27
28 #include <sys/types.h>
29
30 #include <grp.h>
31 #include <unistd.h>
32 #include <stdarg.h>
33 #include <stdlib.h>
34 #include <string.h>
35 #include <limits.h>
36
37 #include "xmalloc.h"
38 #include "groupaccess.h"
39 #include "match.h"
40 #include "log.h"
41
42 static int ngroups;
43 static char **groups_byname;
44
45 /*
46 * Initialize group access list for user with primary (base) and
47 * supplementary groups. Return the number of groups in the list.
48 */
49 int
ga_init(const char * user,gid_t base)50 ga_init(const char *user, gid_t base)
51 {
52 #if defined(ANDROID)
53 return 0;
54 #else
55
56 gid_t *groups_bygid;
57 int i, j;
58 struct group *gr;
59
60 if (ngroups > 0)
61 ga_free();
62
63 ngroups = NGROUPS_MAX;
64 #if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
65 ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX));
66 #endif
67
68 groups_bygid = xcalloc(ngroups, sizeof(*groups_bygid));
69 groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
70
71 if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
72 logit("getgrouplist: groups list too small");
73 for (i = 0, j = 0; i < ngroups; i++)
74 if ((gr = getgrgid(groups_bygid[i])) != NULL)
75 groups_byname[j++] = xstrdup(gr->gr_name);
76 free(groups_bygid);
77 return (ngroups = j);
78 #endif
79 }
80
81 /*
82 * Return 1 if one of user's groups is contained in groups.
83 * Return 0 otherwise. Use match_pattern() for string comparison.
84 */
85 int
ga_match(char * const * groups,int n)86 ga_match(char * const *groups, int n)
87 {
88 int i, j;
89
90 for (i = 0; i < ngroups; i++)
91 for (j = 0; j < n; j++)
92 if (match_pattern(groups_byname[i], groups[j]))
93 return 1;
94 return 0;
95 }
96
97 /*
98 * Return 1 if one of user's groups matches group_pattern list.
99 * Return 0 on negated or no match.
100 */
101 int
ga_match_pattern_list(const char * group_pattern)102 ga_match_pattern_list(const char *group_pattern)
103 {
104 int i, found = 0;
105 size_t len = strlen(group_pattern);
106
107 for (i = 0; i < ngroups; i++) {
108 switch (match_pattern_list(groups_byname[i],
109 group_pattern, len, 0)) {
110 case -1:
111 return 0; /* Negated match wins */
112 case 0:
113 continue;
114 case 1:
115 found = 1;
116 }
117 }
118 return found;
119 }
120
121 /*
122 * Free memory allocated for group access list.
123 */
124 void
ga_free(void)125 ga_free(void)
126 {
127 int i;
128
129 if (ngroups > 0) {
130 for (i = 0; i < ngroups; i++)
131 free(groups_byname[i]);
132 ngroups = 0;
133 free(groups_byname);
134 }
135 }
136