1/*-
2 * Copyright (c) 2003 Networks Associates Technology, Inc.
3 * Copyright (c) 2004-2011 Dag-Erling Smørgrav
4 * All rights reserved.
5 *
6 * Portions of this software were developed for the FreeBSD Project by
7 * ThinkSec AS and NAI Labs, the Security Research Division of Network
8 * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
9 * ("CBOSS"), as part of the DARPA CHATS research program.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote
20 *    products derived from this software without specific prior written
21 *    permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <sys/cdefs.h>
37__FBSDID("$FreeBSD$");
38
39#include <sys/types.h>
40
41#include <grp.h>
42#include <pwd.h>
43#include <stdarg.h>
44#include <stdio.h>
45#include <string.h>
46#include <syslog.h>
47#include <unistd.h>
48
49#define PAM_SM_AUTH
50#define PAM_SM_ACCOUNT
51
52#include <security/pam_appl.h>
53#include <security/pam_modules.h>
54#include <security/openpam.h>
55
56static int
57pam_group(pam_handle_t *pamh)
58{
59	int local, remote;
60	const char *group, *user;
61	const void *ruser;
62	char *const *list;
63	struct passwd *pwd;
64	struct group *grp;
65
66	/* get target account */
67	if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS ||
68	    user == NULL || (pwd = getpwnam(user)) == NULL)
69		return (PAM_AUTH_ERR);
70	if (pwd->pw_uid != 0 && openpam_get_option(pamh, "root_only"))
71		return (PAM_IGNORE);
72
73	/* check local / remote */
74	local = openpam_get_option(pamh, "luser") ? 1 : 0;
75	remote = openpam_get_option(pamh, "ruser") ? 1 : 0;
76	if (local && remote) {
77		openpam_log(PAM_LOG_ERROR, "(pam_group) "
78		    "the luser and ruser options are mutually exclusive");
79		return (PAM_SERVICE_ERR);
80	} else if (local) {
81		/* we already have the correct struct passwd */
82	} else {
83		if (!remote)
84			openpam_log(PAM_LOG_NOTICE, "(pam_group) "
85			    "neither luser nor ruser specified, assuming ruser");
86		/* default / historical behavior */
87		if (pam_get_item(pamh, PAM_RUSER, &ruser) != PAM_SUCCESS ||
88		    ruser == NULL || (pwd = getpwnam(ruser)) == NULL)
89			return (PAM_AUTH_ERR);
90	}
91
92	/* get regulating group */
93	if ((group = openpam_get_option(pamh, "group")) == NULL)
94		group = "wheel";
95	if ((grp = getgrnam(group)) == NULL || grp->gr_mem == NULL)
96		goto failed;
97
98	/* check if user's own primary group */
99	if (pwd->pw_gid == grp->gr_gid)
100		goto found;
101
102	/* iterate over members */
103	for (list = grp->gr_mem; list != NULL && *list != NULL; ++list)
104		if (strcmp(*list, pwd->pw_name) == 0)
105			goto found;
106
107 not_found:
108	if (openpam_get_option(pamh, "deny"))
109		return (PAM_SUCCESS);
110	return (PAM_AUTH_ERR);
111 found:
112	if (openpam_get_option(pamh, "deny"))
113		return (PAM_AUTH_ERR);
114	return (PAM_SUCCESS);
115 failed:
116	if (openpam_get_option(pamh, "fail_safe"))
117		goto found;
118	else
119		goto not_found;
120}
121
122PAM_EXTERN int
123pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
124    int argc __unused, const char *argv[] __unused)
125{
126
127	return (pam_group(pamh));
128}
129
130PAM_EXTERN int
131pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
132    int argc __unused, const char *argv[] __unused)
133{
134
135	return (PAM_SUCCESS);
136}
137
138PAM_EXTERN int
139pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
140    int argc __unused, const char *argv[] __unused)
141{
142
143	return (pam_group(pamh));
144}
145
146PAM_MODULE_ENTRY("pam_group");
147