1 /* $OpenBSD: groupaccess.c,v 1.17 2019/03/06 22:14:23 dtucker 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 gid_t *groups_bygid;
53 int i, j, retry = 0;
54 struct group *gr;
55
56 if (ngroups > 0)
57 ga_free();
58
59 ngroups = NGROUPS_MAX;
60 #if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
61 ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX));
62 #endif
63
64 groups_bygid = xcalloc(ngroups, sizeof(*groups_bygid));
65 while (getgrouplist(user, base, groups_bygid, &ngroups) == -1) {
66 if (retry++ > 0)
67 fatal("getgrouplist: groups list too small");
68 groups_bygid = xreallocarray(groups_bygid, ngroups,
69 sizeof(*groups_bygid));
70 }
71 groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
72
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 }
79
80 /*
81 * Return 1 if one of user's groups is contained in groups.
82 * Return 0 otherwise. Use match_pattern() for string comparison.
83 */
84 int
ga_match(char * const * groups,int n)85 ga_match(char * const *groups, int n)
86 {
87 int i, j;
88
89 for (i = 0; i < ngroups; i++)
90 for (j = 0; j < n; j++)
91 if (match_pattern(groups_byname[i], groups[j]))
92 return 1;
93 return 0;
94 }
95
96 /*
97 * Return 1 if one of user's groups matches group_pattern list.
98 * Return 0 on negated or no match.
99 */
100 int
ga_match_pattern_list(const char * group_pattern)101 ga_match_pattern_list(const char *group_pattern)
102 {
103 int i, found = 0;
104
105 for (i = 0; i < ngroups; i++) {
106 switch (match_usergroup_pattern_list(groups_byname[i],
107 group_pattern)) {
108 case -1:
109 return 0; /* Negated match wins */
110 case 0:
111 continue;
112 case 1:
113 found = 1;
114 }
115 }
116 return found;
117 }
118
119 /*
120 * Free memory allocated for group access list.
121 */
122 void
ga_free(void)123 ga_free(void)
124 {
125 int i;
126
127 if (ngroups > 0) {
128 for (i = 0; i < ngroups; i++)
129 free(groups_byname[i]);
130 ngroups = 0;
131 free(groups_byname);
132 groups_byname = NULL;
133 }
134 }
135