xref: /freebsd/crypto/openssh/groupaccess.c (revision 8d20be1e22095c27faf8fe8b2f0d089739cc742e)
1 /* $OpenBSD: groupaccess.c,v 1.14 2013/05/17 00:13:13 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 "includes.h"
27 
28 #include <sys/types.h>
29 #include <sys/param.h>
30 
31 #include <grp.h>
32 #include <unistd.h>
33 #include <stdarg.h>
34 #include <stdlib.h>
35 #include <string.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
50 ga_init(const char *user, gid_t base)
51 {
52 	gid_t *groups_bygid;
53 	int i, j;
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 	groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
66 
67 	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
68 		logit("getgrouplist: groups list too small");
69 	for (i = 0, j = 0; i < ngroups; i++)
70 		if ((gr = getgrgid(groups_bygid[i])) != NULL)
71 			groups_byname[j++] = xstrdup(gr->gr_name);
72 	free(groups_bygid);
73 	return (ngroups = j);
74 }
75 
76 /*
77  * Return 1 if one of user's groups is contained in groups.
78  * Return 0 otherwise.  Use match_pattern() for string comparison.
79  */
80 int
81 ga_match(char * const *groups, int n)
82 {
83 	int i, j;
84 
85 	for (i = 0; i < ngroups; i++)
86 		for (j = 0; j < n; j++)
87 			if (match_pattern(groups_byname[i], groups[j]))
88 				return 1;
89 	return 0;
90 }
91 
92 /*
93  * Return 1 if one of user's groups matches group_pattern list.
94  * Return 0 on negated or no match.
95  */
96 int
97 ga_match_pattern_list(const char *group_pattern)
98 {
99 	int i, found = 0;
100 	size_t len = strlen(group_pattern);
101 
102 	for (i = 0; i < ngroups; i++) {
103 		switch (match_pattern_list(groups_byname[i],
104 		    group_pattern, len, 0)) {
105 		case -1:
106 			return 0;	/* Negated match wins */
107 		case 0:
108 			continue;
109 		case 1:
110 			found = 1;
111 		}
112 	}
113 	return found;
114 }
115 
116 /*
117  * Free memory allocated for group access list.
118  */
119 void
120 ga_free(void)
121 {
122 	int i;
123 
124 	if (ngroups > 0) {
125 		for (i = 0; i < ngroups; i++)
126 			free(groups_byname[i]);
127 		ngroups = 0;
128 		free(groups_byname);
129 	}
130 }
131