xref: /freebsd/crypto/openssh/groupaccess.c (revision 6fd05b64b5b65dd4ba9b86482a0634a5f0b96c29)
1 /*
2  * Copyright (c) 2001 Kevin Steves.  All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23  */
24 
25 #include "includes.h"
26 RCSID("$OpenBSD: groupaccess.c,v 1.6 2003/04/08 20:21:28 itojun Exp $");
27 
28 #include "groupaccess.h"
29 #include "xmalloc.h"
30 #include "match.h"
31 #include "log.h"
32 
33 static int ngroups;
34 static char **groups_byname;
35 
36 /*
37  * Initialize group access list for user with primary (base) and
38  * supplementary groups.  Return the number of groups in the list.
39  */
40 int
41 ga_init(const char *user, gid_t base)
42 {
43 	gid_t *groups_bygid;
44 	int i, j;
45 	struct group *gr;
46 
47 	if (ngroups > 0)
48 		ga_free();
49 
50 	ngroups = NGROUPS_MAX;
51 #if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
52 	ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX));
53 #endif
54 
55 	groups_bygid = xmalloc(ngroups * sizeof(*groups_bygid));
56 	groups_byname = xmalloc(ngroups * sizeof(*groups_byname));
57 
58 	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
59 		logit("getgrouplist: groups list too small");
60 	for (i = 0, j = 0; i < ngroups; i++)
61 		if ((gr = getgrgid(groups_bygid[i])) != NULL)
62 			groups_byname[j++] = xstrdup(gr->gr_name);
63 	xfree(groups_bygid);
64 	return (ngroups = j);
65 }
66 
67 /*
68  * Return 1 if one of user's groups is contained in groups.
69  * Return 0 otherwise.  Use match_pattern() for string comparison.
70  */
71 int
72 ga_match(char * const *groups, int n)
73 {
74 	int i, j;
75 
76 	for (i = 0; i < ngroups; i++)
77 		for (j = 0; j < n; j++)
78 			if (match_pattern(groups_byname[i], groups[j]))
79 				return 1;
80 	return 0;
81 }
82 
83 /*
84  * Free memory allocated for group access list.
85  */
86 void
87 ga_free(void)
88 {
89 	int i;
90 
91 	if (ngroups > 0) {
92 		for (i = 0; i < ngroups; i++)
93 			xfree(groups_byname[i]);
94 		ngroups = 0;
95 		xfree(groups_byname);
96 	}
97 }
98