pam_securetty.c revision 331722 
1/*-
2 * Copyright (c) 2001 Mark R V Murray
3 * All rights reserved.
4 * Copyright (c) 2001 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__FBSDID("$FreeBSD: stable/11/lib/libpam/modules/pam_securetty/pam_securetty.c 331722 2018-03-29 02:50:57Z eadler $");
39
40#include <sys/types.h>
41#include <sys/stat.h>
42#include <pwd.h>
43#include <ttyent.h>
44#include <string.h>
45
46#define PAM_SM_ACCOUNT
47
48#include <security/pam_appl.h>
49#include <security/pam_modules.h>
50#include <security/pam_mod_misc.h>
51
52#define TTY_PREFIX	"/dev/"
53
54PAM_EXTERN int
55pam_sm_acct_mgmt(pam_handle_t *pamh __unused, int flags __unused,
56    int argc __unused, const char *argv[] __unused)
57{
58	struct passwd *pwd;
59	struct ttyent *ty;
60	const char *user;
61	const void *tty;
62	int pam_err;
63
64	pam_err = pam_get_user(pamh, &user, NULL);
65	if (pam_err != PAM_SUCCESS)
66		return (pam_err);
67	if (user == NULL || (pwd = getpwnam(user)) == NULL)
68		return (PAM_SERVICE_ERR);
69
70	PAM_LOG("Got user: %s", user);
71
72	/* If the user is not root, secure ttys do not apply */
73	if (pwd->pw_uid != 0)
74		return (PAM_SUCCESS);
75
76	pam_err = pam_get_item(pamh, PAM_TTY, &tty);
77	if (pam_err != PAM_SUCCESS)
78		return (pam_err);
79
80	PAM_LOG("Got TTY: %s", (const char *)tty);
81
82	/* Ignore any "/dev/" on the PAM_TTY item */
83	if (tty != NULL && strncmp(TTY_PREFIX, tty, sizeof(TTY_PREFIX)) == 0) {
84		PAM_LOG("WARNING: PAM_TTY starts with " TTY_PREFIX);
85		tty = (const char *)tty + sizeof(TTY_PREFIX) - 1;
86	}
87
88	if (tty != NULL && (ty = getttynam(tty)) != NULL &&
89	    (ty->ty_status & TTY_SECURE) != 0)
90		return (PAM_SUCCESS);
91
92	PAM_VERBOSE_ERROR("Not on secure TTY");
93	return (PAM_AUTH_ERR);
94}
95
96PAM_MODULE_ENTRY("pam_securetty");
97