1/*-
2 * Copyright (c) 2003 Networks Associates Technology, Inc.
3 * All rights reserved.
4 *
5 * Portions of this software were developed for the FreeBSD Project by
6 * ThinkSec AS and NAI Labs, the Security Research Division of Network
7 * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
8 * ("CBOSS"), as part of the DARPA CHATS research program.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. The name of the author may not be used to endorse or promote
19 *    products derived from this software without specific prior written
20 *    permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD$");
37
38#include <string.h>
39
40#define PAM_SM_AUTH
41
42#include <security/pam_appl.h>
43#include <security/pam_modules.h>
44#include <security/openpam.h>
45
46#define DEFAULT_GUESTS	"guest"
47
48static int
49lookup(const char *str, const char *list)
50{
51	const char *next;
52	size_t len;
53
54	len = strlen(str);
55	while (*list != '\0') {
56		while (*list == ',')
57			++list;
58		if ((next = strchr(list, ',')) == NULL)
59			next = strchr(list, '\0');
60		if (next - list == (ptrdiff_t)len &&
61		    strncmp(list, str, len) == 0)
62			return (1);
63		list = next;
64	}
65	return (0);
66}
67
68PAM_EXTERN int
69pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
70    int argc __unused, const char *argv[] __unused)
71{
72	const char *authtok, *guests, *user;
73	int err, is_guest;
74
75	/* get target account */
76	if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS || user == NULL)
77		return (PAM_AUTH_ERR);
78
79	/* get list of guest logins */
80	if ((guests = openpam_get_option(pamh, "guests")) == NULL)
81		guests = DEFAULT_GUESTS;
82
83	/* check if the target account is on the list */
84	is_guest = lookup(user, guests);
85
86	/* check password */
87	if (!openpam_get_option(pamh, "nopass")) {
88		err = pam_get_authtok(pamh, PAM_AUTHTOK, &authtok, NULL);
89		if (err != PAM_SUCCESS)
90			return (err);
91		if (openpam_get_option(pamh, "pass_is_user") &&
92		    strcmp(user, authtok) != 0)
93			return (PAM_AUTH_ERR);
94		if (openpam_get_option(pamh, "pass_as_ruser"))
95			pam_set_item(pamh, PAM_RUSER, authtok);
96	}
97
98	/* done */
99	if (is_guest) {
100		pam_setenv(pamh, "GUEST", user, 1);
101		return (PAM_SUCCESS);
102	}
103	return (PAM_AUTH_ERR);
104}
105
106PAM_EXTERN int
107pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
108    int argc __unused, const char *argv[] __unused)
109{
110
111	return (PAM_SUCCESS);
112}
113
114PAM_MODULE_ENTRY("pam_guest");
115