xref: /openbsd/usr.bin/ssh/groupaccess.c (revision c1d304b2)
1 /*	$OpenBSD: groupaccess.c,v 1.4 2001/06/26 17:27:23 markus Exp $	*/
2 
3 /*
4  * Copyright (c) 2001 Kevin Steves.  All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include "includes.h"
28 
29 #include "groupaccess.h"
30 #include "xmalloc.h"
31 #include "match.h"
32 #include "log.h"
33 
34 static int ngroups;
35 static char *groups_byname[NGROUPS_MAX + 1];	/* +1 for base/primary group */
36 
37 /*
38  * Initialize group access list for user with primary (base) and
39  * supplementary groups.  Return the number of groups in the list.
40  */
41 int
42 ga_init(const char *user, gid_t base)
43 {
44 	gid_t groups_bygid[NGROUPS_MAX + 1];
45 	int i, j;
46 	struct group *gr;
47 
48 	if (ngroups > 0)
49 		ga_free();
50 
51 	ngroups = sizeof(groups_bygid) / sizeof(gid_t);
52 	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
53 		log("getgrouplist: groups list too small");
54 	for (i = 0, j = 0; i < ngroups; i++)
55 		if ((gr = getgrgid(groups_bygid[i])) != NULL)
56 			groups_byname[j++] = xstrdup(gr->gr_name);
57 	return (ngroups = j);
58 }
59 
60 /*
61  * Return 1 if one of user's groups is contained in groups.
62  * Return 0 otherwise.  Use match_pattern() for string comparison.
63  */
64 int
65 ga_match(char * const *groups, int n)
66 {
67 	int i, j;
68 
69 	for (i = 0; i < ngroups; i++)
70 		for (j = 0; j < n; j++)
71 			if (match_pattern(groups_byname[i], groups[j]))
72 				return 1;
73 	return 0;
74 }
75 
76 /*
77  * Free memory allocated for group access list.
78  */
79 void
80 ga_free(void)
81 {
82 	int i;
83 
84 	if (ngroups > 0) {
85 		for (i = 0; i < ngroups; i++)
86 			xfree(groups_byname[i]);
87 		ngroups = 0;
88 	}
89 }
90