summaryrefslogtreecommitdiff
path: root/libpam/pam_modutil_ingroup.c
blob: adb9dadba3705ba7a0ecd0a4396aac28a55719e3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
/*
 * $Id: pam_modutil_ingroup.c,v 1.1 2005/09/21 10:00:58 t8m Exp $
 *
 * This function provides common methods for checking if a user is in a
 * specified group.
 */

#include "pam_modutil_private.h"

#include <stdlib.h>
#include <pwd.h>
#include <grp.h>

#ifdef HAVE_GETGROUPLIST
static int checkgrouplist(const char *user, gid_t primary, gid_t target)
{
	gid_t *grouplist = NULL;
	int agroups, ngroups, i;
	ngroups = agroups = 3;
	do {
		grouplist = malloc(sizeof(gid_t) * agroups);
		if (grouplist == NULL) {
			return 0;
		}
		ngroups = agroups;
		i = getgrouplist(user, primary, grouplist, &ngroups);
		if ((i < 0) || (ngroups < 1)) {
			agroups *= 2;
			free(grouplist);
		} else {
			for (i = 0; i < ngroups; i++) {
				if (grouplist[i] == target) {
					free(grouplist);
					return 1;
				}
			}
			free(grouplist);
		}
	} while (((i < 0) || (ngroups < 1)) && (agroups < 10000));
	return 0;
}
#endif

static int
pam_modutil_user_in_group_common(pam_handle_t *pamh UNUSED,
				 struct passwd *pwd,
				 struct group *grp)
{
	int i;

	if (pwd == NULL) {
		return 0;
	}
	if (grp == NULL) {
		return 0;
	}

	if (pwd->pw_gid == grp->gr_gid) {
		return 1;
	}

	for (i = 0; (grp->gr_mem != NULL) && (grp->gr_mem[i] != NULL); i++) {
		if (strcmp(pwd->pw_name, grp->gr_mem[i]) == 0) {
			return 1;
		}
	}

#ifdef HAVE_GETGROUPLIST
	if (checkgrouplist(pwd->pw_name, pwd->pw_gid, grp->gr_gid)) {
		return 1;
	}
#endif

	return 0;
}

int 
pam_modutil_user_in_group_nam_nam(pam_handle_t *pamh,
				 const char *user, const char *group)
{
	struct passwd *pwd;
	struct group *grp;

	pwd = pam_modutil_getpwnam(pamh, user);
	grp = pam_modutil_getgrnam(pamh, group);

	return pam_modutil_user_in_group_common(pamh, pwd, grp);
}

int
pam_modutil_user_in_group_nam_gid(pam_handle_t *pamh,
				  const char *user, gid_t group)
{
	struct passwd *pwd;
	struct group *grp;

	pwd = pam_modutil_getpwnam(pamh, user);
	grp = pam_modutil_getgrgid(pamh, group);

	return pam_modutil_user_in_group_common(pamh, pwd, grp);
}

int
pam_modutil_user_in_group_uid_nam(pam_handle_t *pamh,
				  uid_t user, const char *group)
{
	struct passwd *pwd;
	struct group *grp;

	pwd = pam_modutil_getpwuid(pamh, user);
	grp = pam_modutil_getgrnam(pamh, group);

	return pam_modutil_user_in_group_common(pamh, pwd, grp);
}

int
pam_modutil_user_in_group_uid_gid(pam_handle_t *pamh,
				  uid_t user, gid_t group)
{
	struct passwd *pwd;
	struct group *grp;

	pwd = pam_modutil_getpwuid(pamh, user);
	grp = pam_modutil_getgrgid(pamh, group);

	return pam_modutil_user_in_group_common(pamh, pwd, grp);
}