xref: /openbsd/usr.bin/ssh/groupaccess.c (revision 0d40fefd)
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 <sys/types.h>
27 #include <sys/param.h>
28 
29 #include <grp.h>
30 #include <unistd.h>
31 #include <stdarg.h>
32 #include <stdlib.h>
33 #include <string.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[NGROUPS_MAX + 1];	/* +1 for base/primary group */
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[NGROUPS_MAX + 1];
51 	int i, j;
52 	struct group *gr;
53 
54 	if (ngroups > 0)
55 		ga_free();
56 
57 	ngroups = sizeof(groups_bygid) / sizeof(gid_t);
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 	return (ngroups = j);
64 }
65 
66 /*
67  * Return 1 if one of user's groups is contained in groups.
68  * Return 0 otherwise.  Use match_pattern() for string comparison.
69  */
70 int
71 ga_match(char * const *groups, int n)
72 {
73 	int i, j;
74 
75 	for (i = 0; i < ngroups; i++)
76 		for (j = 0; j < n; j++)
77 			if (match_pattern(groups_byname[i], groups[j]))
78 				return 1;
79 	return 0;
80 }
81 
82 /*
83  * Return 1 if one of user's groups matches group_pattern list.
84  * Return 0 on negated or no match.
85  */
86 int
87 ga_match_pattern_list(const char *group_pattern)
88 {
89 	int i, found = 0;
90 	size_t len = strlen(group_pattern);
91 
92 	for (i = 0; i < ngroups; i++) {
93 		switch (match_pattern_list(groups_byname[i],
94 		    group_pattern, len, 0)) {
95 		case -1:
96 			return 0;	/* Negated match wins */
97 		case 0:
98 			continue;
99 		case 1:
100 			found = 1;
101 		}
102 	}
103 	return found;
104 }
105 
106 /*
107  * Free memory allocated for group access list.
108  */
109 void
110 ga_free(void)
111 {
112 	int i;
113 
114 	if (ngroups > 0) {
115 		for (i = 0; i < ngroups; i++)
116 			free(groups_byname[i]);
117 		ngroups = 0;
118 	}
119 }
120