1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2003 Networks Associates Technology, Inc.
5 * All rights reserved.
6 *
7 * Portions of this software were developed for the FreeBSD Project by
8 * ThinkSec AS and NAI Labs, the Security Research Division of Network
9 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
10 * ("CBOSS"), as part of the DARPA CHATS research program.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote
21 * products derived from this software without specific prior written
22 * permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * $FreeBSD: head/lib/libpam/modules/pam_guest/pam_guest.c 326219 2017-11-26 02:00:33Z pfg $
37 */
38
39 #include <string.h>
40
41 #define PAM_SM_AUTH
42
43 #include <security/pam_appl.h>
44 #include <security/pam_modules.h>
45 #include <security/openpam.h>
46
47 #define DEFAULT_GUESTS "guest"
48
49 static int
lookup(const char * str,const char * list)50 lookup(const char *str, const char *list)
51 {
52 const char *next;
53 size_t len;
54
55 len = strlen(str);
56 while (*list != '\0') {
57 while (*list == ',')
58 ++list;
59 if ((next = strchr(list, ',')) == NULL)
60 next = strchr(list, '\0');
61 if (next - list == (ptrdiff_t)len &&
62 strncmp(list, str, len) == 0)
63 return (1);
64 list = next;
65 }
66 return (0);
67 }
68
69 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)70 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
71 int argc __unused, const char *argv[] __unused)
72 {
73 const char *authtok, *guests, *user;
74 int err, is_guest;
75
76 /* get target account */
77 if (pam_get_user(pamh, &user, NULL) != PAM_SUCCESS || user == NULL)
78 return (PAM_AUTH_ERR);
79
80 /* get list of guest logins */
81 if ((guests = openpam_get_option(pamh, "guests")) == NULL)
82 guests = DEFAULT_GUESTS;
83
84 /* check if the target account is on the list */
85 is_guest = lookup(user, guests);
86
87 /* check password */
88 if (!openpam_get_option(pamh, "nopass")) {
89 err = pam_get_authtok(pamh, PAM_AUTHTOK, &authtok, NULL);
90 if (err != PAM_SUCCESS)
91 return (err);
92 if (openpam_get_option(pamh, "pass_is_user") &&
93 strcmp(user, authtok) != 0)
94 return (PAM_AUTH_ERR);
95 if (openpam_get_option(pamh, "pass_as_ruser"))
96 pam_set_item(pamh, PAM_RUSER, authtok);
97 }
98
99 /* done */
100 if (is_guest) {
101 pam_setenv(pamh, "GUEST", user, 1);
102 return (PAM_SUCCESS);
103 }
104 return (PAM_AUTH_ERR);
105 }
106
107 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)108 pam_sm_setcred(pam_handle_t * pamh __unused, int flags __unused,
109 int argc __unused, const char *argv[] __unused)
110 {
111
112 return (PAM_SUCCESS);
113 }
114
115 PAM_MODULE_ENTRY("pam_guest");
116