1 /* $OpenBSD: groupaccess.c,v 1.18 2024/11/04 21:59:15 jca 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 ongroups, i, j, retry = 0;
54 struct group *gr;
55
56 if (ngroups > 0)
57 ga_free();
58
59 ongroups = ngroups = NGROUPS_MAX;
60 #if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
61 ongroups = 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 (ngroups <= ongroups) {
67 error("getgrouplist(\"%s\", %ld): failed",
68 user, (long)base);
69 free(groups_bygid);
70 groups_bygid = NULL;
71 ngroups = 0;
72 return 0;
73 }
74 if (retry++ > 0) {
75 fatal("getgrouplist(\"%s\", %ld): groups list too big "
76 "(have %ld, need %ld)", user, (long)base,
77 (long)ongroups, (long)ngroups);
78 }
79 groups_bygid = xreallocarray(groups_bygid, ngroups,
80 sizeof(*groups_bygid));
81 }
82 groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
83
84 for (i = 0, j = 0; i < ngroups; i++)
85 if ((gr = getgrgid(groups_bygid[i])) != NULL)
86 groups_byname[j++] = xstrdup(gr->gr_name);
87 free(groups_bygid);
88 return (ngroups = j);
89 }
90
91 /*
92 * Return 1 if one of user's groups is contained in groups.
93 * Return 0 otherwise. Use match_pattern() for string comparison.
94 */
95 int
ga_match(char * const * groups,int n)96 ga_match(char * const *groups, int n)
97 {
98 int i, j;
99
100 for (i = 0; i < ngroups; i++)
101 for (j = 0; j < n; j++)
102 if (match_pattern(groups_byname[i], groups[j]))
103 return 1;
104 return 0;
105 }
106
107 /*
108 * Return 1 if one of user's groups matches group_pattern list.
109 * Return 0 on negated or no match.
110 */
111 int
ga_match_pattern_list(const char * group_pattern)112 ga_match_pattern_list(const char *group_pattern)
113 {
114 int i, found = 0;
115
116 for (i = 0; i < ngroups; i++) {
117 switch (match_usergroup_pattern_list(groups_byname[i],
118 group_pattern)) {
119 case -1:
120 return 0; /* Negated match wins */
121 case 0:
122 continue;
123 case 1:
124 found = 1;
125 }
126 }
127 return found;
128 }
129
130 /*
131 * Free memory allocated for group access list.
132 */
133 void
ga_free(void)134 ga_free(void)
135 {
136 int i;
137
138 if (ngroups > 0) {
139 for (i = 0; i < ngroups; i++)
140 free(groups_byname[i]);
141 ngroups = 0;
142 free(groups_byname);
143 groups_byname = NULL;
144 }
145 }
146