xref: /openbsd-src/usr.bin/ssh/groupaccess.c (revision daf88648c0e349d5c02e1504293082072c981640)
1 /* $OpenBSD: groupaccess.c,v 1.12 2006/08/03 03:34:42 deraadt 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 
33 #include "xmalloc.h"
34 #include "groupaccess.h"
35 #include "match.h"
36 #include "log.h"
37 
38 static int ngroups;
39 static char *groups_byname[NGROUPS_MAX + 1];	/* +1 for base/primary group */
40 
41 /*
42  * Initialize group access list for user with primary (base) and
43  * supplementary groups.  Return the number of groups in the list.
44  */
45 int
46 ga_init(const char *user, gid_t base)
47 {
48 	gid_t groups_bygid[NGROUPS_MAX + 1];
49 	int i, j;
50 	struct group *gr;
51 
52 	if (ngroups > 0)
53 		ga_free();
54 
55 	ngroups = sizeof(groups_bygid) / sizeof(gid_t);
56 	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
57 		logit("getgrouplist: groups list too small");
58 	for (i = 0, j = 0; i < ngroups; i++)
59 		if ((gr = getgrgid(groups_bygid[i])) != NULL)
60 			groups_byname[j++] = xstrdup(gr->gr_name);
61 	return (ngroups = j);
62 }
63 
64 /*
65  * Return 1 if one of user's groups is contained in groups.
66  * Return 0 otherwise.  Use match_pattern() for string comparison.
67  */
68 int
69 ga_match(char * const *groups, int n)
70 {
71 	int i, j;
72 
73 	for (i = 0; i < ngroups; i++)
74 		for (j = 0; j < n; j++)
75 			if (match_pattern(groups_byname[i], groups[j]))
76 				return 1;
77 	return 0;
78 }
79 
80 /*
81  * Free memory allocated for group access list.
82  */
83 void
84 ga_free(void)
85 {
86 	int i;
87 
88 	if (ngroups > 0) {
89 		for (i = 0; i < ngroups; i++)
90 			xfree(groups_byname[i]);
91 		ngroups = 0;
92 	}
93 }
94