1 /*	$NetBSD: pam_securetty.c,v 1.7 2006/11/03 18:55:40 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001 Mark R V Murray
5  * All rights reserved.
6  * Copyright (c) 2001 Networks Associates Technology, Inc.
7  * All rights reserved.
8  *
9  * Portions of this software were developed for the FreeBSD Project by
10  * ThinkSec AS and NAI Labs, the Security Research Division of Network
11  * Associates, Inc.  under DARPA/SPAWAR contract N66001-01-C-8035
12  * ("CBOSS"), as part of the DARPA CHATS research program.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. The name of the author may not be used to endorse or promote
23  *    products derived from this software without specific prior written
24  *    permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #ifdef __FreeBSD__
41 __FBSDID("$FreeBSD: src/lib/libpam/modules/pam_securetty/pam_securetty.c,v 1.13 2004/02/10 10:13:21 des Exp $");
42 #else
43 __RCSID("$NetBSD: pam_securetty.c,v 1.7 2006/11/03 18:55:40 christos Exp $");
44 #endif
45 
46 #include <sys/types.h>
47 #include <sys/stat.h>
48 #include <pwd.h>
49 #include <ttyent.h>
50 #include <string.h>
51 #include <syslog.h>
52 
53 #define PAM_SM_ACCOUNT
54 
55 #include <security/pam_appl.h>
56 #include <security/pam_modules.h>
57 #include <security/pam_mod_misc.h>
58 
59 #define TTY_PREFIX	"/dev/"
60 
61 PAM_EXTERN int
62 pam_sm_acct_mgmt(pam_handle_t *pamh __unused, int flags __unused,
63     int argc __unused, const char *argv[] __unused)
64 {
65 	struct passwd *pwd, pwres;
66 	struct ttyent *ty;
67 	const char *user;
68 	const void *tty;
69 	const void *hostname;
70 	int pam_err;
71 	char pwbuf[1024];
72 	struct syslog_data data = SYSLOG_DATA_INIT;
73 
74 	pam_err = pam_get_user(pamh, &user, NULL);
75 	if (pam_err != PAM_SUCCESS)
76 		return (pam_err);
77 	if (user == NULL ||
78 	    getpwnam_r(user, &pwres, pwbuf, sizeof(pwbuf), &pwd) != 0 ||
79 	    pwd == NULL)
80 		return (PAM_SERVICE_ERR);
81 
82 	PAM_LOG("Got user: %s", user);
83 
84 	/* If the user is not root, secure ttys do not apply */
85 	if (pwd->pw_uid != 0)
86 		return (PAM_SUCCESS);
87 
88 	pam_err = pam_get_item(pamh, PAM_TTY, &tty);
89 	if (pam_err != PAM_SUCCESS)
90 		return (pam_err);
91 
92 	PAM_LOG("Got TTY: %s", (const char *)tty);
93 
94 	/* Ignore any "/dev/" on the PAM_TTY item */
95 	if (tty != NULL && strncmp(TTY_PREFIX, tty, sizeof(TTY_PREFIX)) == 0) {
96 		PAM_LOG("WARNING: PAM_TTY starts with " TTY_PREFIX);
97 		tty = (const char *)tty + sizeof(TTY_PREFIX) - 1;
98 	}
99 
100 	if (tty != NULL && (ty = getttynam(tty)) != NULL &&
101 	    (ty->ty_status & TTY_SECURE) != 0)
102 		return (PAM_SUCCESS);
103 
104 	pam_err = pam_get_item(pamh, PAM_RHOST, &hostname);
105 	if (pam_err != PAM_SUCCESS)
106 		hostname = NULL;
107 
108 	openlog_r("pam_securetty", LOG_PID, LOG_AUTHPRIV, &data);
109 	if (hostname)
110 		syslog_r(LOG_NOTICE, &data,
111 		    "LOGIN %s REFUSED FROM %s ON TTY %s",
112 		     pwd->pw_name, (const char *)hostname,
113 		     (const char *)tty);
114 	else
115 		syslog_r(LOG_NOTICE, &data,
116 		    "LOGIN %s REFUSED ON TTY %s",
117 		     pwd->pw_name, (const char *)tty);
118 	closelog_r(&data);
119 
120 
121 	PAM_VERBOSE_ERROR("Not on secure TTY");
122 	return (PAM_AUTH_ERR);
123 }
124 
125 PAM_MODULE_ENTRY("pam_securetty");
126