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
37 #include <sys/cdefs.h>
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
48 static int
lookup(const char * str,const char * list)49 lookup(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
68 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)69 pam_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
106 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)107 pam_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
114 PAM_MODULE_ENTRY("pam_guest");
115