xref: /freebsd/crypto/openssh/groupaccess.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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 "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 
35 #include "xmalloc.h"
36 #include "groupaccess.h"
37 #include "match.h"
38 #include "log.h"
39 
40 static int ngroups;
41 static char **groups_byname;
42 
43 /*
44  * Initialize group access list for user with primary (base) and
45  * supplementary groups.  Return the number of groups in the list.
46  */
47 int
48 ga_init(const char *user, gid_t base)
49 {
50 	gid_t *groups_bygid;
51 	int i, j;
52 	struct group *gr;
53 
54 	if (ngroups > 0)
55 		ga_free();
56 
57 	ngroups = NGROUPS_MAX;
58 #if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
59 	ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX));
60 #endif
61 
62 	groups_bygid = xcalloc(ngroups, sizeof(*groups_bygid));
63 	groups_byname = xcalloc(ngroups, sizeof(*groups_byname));
64 
65 	if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
66 		logit("getgrouplist: groups list too small");
67 	for (i = 0, j = 0; i < ngroups; i++)
68 		if ((gr = getgrgid(groups_bygid[i])) != NULL)
69 			groups_byname[j++] = xstrdup(gr->gr_name);
70 	xfree(groups_bygid);
71 	return (ngroups = j);
72 }
73 
74 /*
75  * Return 1 if one of user's groups is contained in groups.
76  * Return 0 otherwise.  Use match_pattern() for string comparison.
77  */
78 int
79 ga_match(char * const *groups, int n)
80 {
81 	int i, j;
82 
83 	for (i = 0; i < ngroups; i++)
84 		for (j = 0; j < n; j++)
85 			if (match_pattern(groups_byname[i], groups[j]))
86 				return 1;
87 	return 0;
88 }
89 
90 /*
91  * Free memory allocated for group access list.
92  */
93 void
94 ga_free(void)
95 {
96 	int i;
97 
98 	if (ngroups > 0) {
99 		for (i = 0; i < ngroups; i++)
100 			xfree(groups_byname[i]);
101 		ngroups = 0;
102 		xfree(groups_byname);
103 	}
104 }
105