1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2003 Networks Associates Technology, Inc.
5 * Copyright (c) 2004-2011 Dag-Erling Sm��rgrav
6 * All rights reserved.
7 *
8 * Portions of this software were developed for the FreeBSD Project by
9 * ThinkSec AS and NAI Labs, the Security Research Division of Network
10 * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
11 * ("CBOSS"), as part of the DARPA CHATS research program.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 *    notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 *    notice, this list of conditions and the following disclaimer in the
20 *    documentation and/or other materials provided with the distribution.
21 * 3. The name of the author may not be used to endorse or promote
22 *    products derived from this software without specific prior written
23 *    permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38#include <sys/types.h>
39
40#include <grp.h>
41#include <pwd.h>
42#include <stdarg.h>
43#include <stdio.h>
44#include <string.h>
45#include <syslog.h>
46#include <unistd.h>
47
48#define PAM_SM_AUTH
49#define PAM_SM_ACCOUNT
50
51#include <security/pam_appl.h>
52#include <security/pam_modules.h>
53#include <security/openpam.h>
54
55static int
56pam_group(pam_handle_t *pamh)
57{
58	int local, remote;
59	const char *group, *user;
60	const void *ruser;
61	char *const *list;
62	struct passwd *pwd;
63	struct group *grp;
64
65	/* get target account */
66	if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
67	    user == NULL || (pwd = getpwnam(user)) == NULL)
68		return (PAM_AUTH_ERR);
69	if (pwd->pw_uid != 0 && openpam_get_option(pamh, "root_only"))
70		return (PAM_IGNORE);
71
72	/* check local / remote */
73	local = openpam_get_option(pamh, "luser") ? 1 : 0;
74	remote = openpam_get_option(pamh, "ruser") ? 1 : 0;
75	if (local && remote) {
76		openpam_log(PAM_LOG_ERROR, "(pam_group) "
77		    "the luser and ruser options are mutually exclusive");
78		return (PAM_SERVICE_ERR);
79	} else if (local) {
80		/* we already have the correct struct passwd */
81	} else {
82		if (!remote)
83			openpam_log(PAM_LOG_NOTICE, "(pam_group) "
84			    "neither luser nor ruser specified, assuming ruser");
85		/* default / historical behavior */
86		if (pam_get_item(pamh, PAM_RUSER, &ruser) != PAM_SUCCESS ||
87		    ruser == NULL || (pwd = getpwnam(ruser)) == NULL)
88			return (PAM_AUTH_ERR);
89	}
90
91	/* get regulating group */
92	if ((group = openpam_get_option(pamh, "group")) == NULL)
93		group = "wheel";
94	if ((grp = getgrnam(group)) == NULL || grp->gr_mem == NULL)
95		goto failed;
96
97	/* check if user's own primary group */
98	if (pwd->pw_gid == grp->gr_gid)
99		goto found;
100
101	/* iterate over members */
102	for (list = grp->gr_mem; list != NULL && *list != NULL; ++list)
103		if (strcmp(*list, pwd->pw_name) == 0)
104			goto found;
105
106 not_found:
107	if (openpam_get_option(pamh, "deny"))
108		return (PAM_SUCCESS);
109	return (PAM_AUTH_ERR);
110 found:
111	if (openpam_get_option(pamh, "deny"))
112		return (PAM_AUTH_ERR);
113	return (PAM_SUCCESS);
114 failed:
115	if (openpam_get_option(pamh, "fail_safe"))
116		goto found;
117	else
118		goto not_found;
119}
120
121PAM_EXTERN int
122pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
123    int argc __unused, const char *argv[] __unused)
124{
125
126	return (pam_group(pamh));
127}
128
129PAM_EXTERN int
130pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
131    int argc __unused, const char *argv[] __unused)
132{
133
134	return (PAM_SUCCESS);
135}
136
137PAM_EXTERN int
138pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
139    int argc __unused, const char *argv[] __unused)
140{
141
142	return (pam_group(pamh));
143}
144
145PAM_MODULE_ENTRY("pam_group");
146