xref: /openbsd-src/usr.bin/ssh/groupaccess.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /* $OpenBSD: groupaccess.c,v 1.13 2008/07/04 03:44:59 djm 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 <sys/types.h>
27 #include <sys/param.h>
28 
29 #include <grp.h>
30 #include <unistd.h>
31 #include <stdarg.h>
32 #include <string.h>
33 
34 #include "xmalloc.h"
35 #include "groupaccess.h"
36 #include "match.h"
37 #include "log.h"
38 
39 static int ngroups;
40 static char *groups_byname[NGROUPS_MAX + 1];	/* +1 for base/primary group */
41 
42 /*
43  * Initialize group access list for user with primary (base) and
44  * supplementary groups.  Return the number of groups in the list.
45  */
46 int
47 ga_init(const char *user, gid_t base)
48 {
49 	gid_t groups_bygid[NGROUPS_MAX + 1];
50 	int i, j;
51 	struct group *gr;
52 
53 	if (ngroups > 0)
54 		ga_free();
55 
56 	ngroups = sizeof(groups_bygid) / sizeof(gid_t);
57 	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
58 		logit("getgrouplist: groups list too small");
59 	for (i = 0, j = 0; i < ngroups; i++)
60 		if ((gr = getgrgid(groups_bygid[i])) != NULL)
61 			groups_byname[j++] = xstrdup(gr->gr_name);
62 	return (ngroups = j);
63 }
64 
65 /*
66  * Return 1 if one of user's groups is contained in groups.
67  * Return 0 otherwise.  Use match_pattern() for string comparison.
68  */
69 int
70 ga_match(char * const *groups, int n)
71 {
72 	int i, j;
73 
74 	for (i = 0; i < ngroups; i++)
75 		for (j = 0; j < n; j++)
76 			if (match_pattern(groups_byname[i], groups[j]))
77 				return 1;
78 	return 0;
79 }
80 
81 /*
82  * Return 1 if one of user's groups matches group_pattern list.
83  * Return 0 on negated or no match.
84  */
85 int
86 ga_match_pattern_list(const char *group_pattern)
87 {
88 	int i, found = 0;
89 	size_t len = strlen(group_pattern);
90 
91 	for (i = 0; i < ngroups; i++) {
92 		switch (match_pattern_list(groups_byname[i],
93 		    group_pattern, len, 0)) {
94 		case -1:
95 			return 0;	/* Negated match wins */
96 		case 0:
97 			continue;
98 		case 1:
99 			found = 1;
100 		}
101 	}
102 	return found;
103 }
104 
105 /*
106  * Free memory allocated for group access list.
107  */
108 void
109 ga_free(void)
110 {
111 	int i;
112 
113 	if (ngroups > 0) {
114 		for (i = 0; i < ngroups; i++)
115 			xfree(groups_byname[i]);
116 		ngroups = 0;
117 	}
118 }
119