1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1980, 1987, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Bob Toxen.
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. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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#ifndef lint
36static const char copyright[] =
37"@(#) Copyright (c) 1980, 1987, 1993\n\
38	The Regents of the University of California.  All rights reserved.\n";
39#endif /* not lint */
40
41#ifndef lint
42#if 0
43static char sccsid[] = "@(#)lock.c	8.1 (Berkeley) 6/6/93";
44#endif
45#endif /* not lint */
46#include <sys/cdefs.h>
47__FBSDID("$FreeBSD$");
48
49/*
50 * Lock a terminal up until the given key is entered or the given
51 * interval times out.
52 *
53 * Timeout interval is by default TIMEOUT, it can be changed with
54 * an argument of the form -time where time is in minutes
55 */
56
57#include <sys/param.h>
58#include <sys/stat.h>
59#include <sys/signal.h>
60#include <sys/consio.h>
61
62#include <err.h>
63#include <ctype.h>
64#include <errno.h>
65#include <paths.h>
66#include <pwd.h>
67#include <stdint.h>
68#include <stdio.h>
69#include <stdlib.h>
70#include <string.h>
71#include <syslog.h>
72#include <termios.h>
73#include <time.h>
74#include <unistd.h>
75
76#include <security/pam_appl.h>
77#include <security/openpam.h>	/* for openpam_ttyconv() */
78
79#define	TIMEOUT	15
80
81static void quit(int);
82static void bye(int);
83static void hi(int);
84static void usage(void);
85
86static struct timeval	timeout;
87static struct timeval	zerotime;
88static struct termios	tty, ntty;
89static long		nexttime;		/* keep the timeout time */
90static int		no_timeout;		/* lock terminal forever */
91static int		vtyunlock;		/* Unlock flag and code. */
92
93/*ARGSUSED*/
94int
95main(int argc, char **argv)
96{
97	static const struct pam_conv pamc = { &openpam_ttyconv, NULL };
98	pam_handle_t *pamh;
99	struct passwd *pw;
100	struct itimerval ntimer, otimer;
101	struct tm *timp;
102	time_t timval;
103	int ch, failures, pam_err, sectimeout, usemine, vtylock;
104	char *ap, *ttynam, *tzn;
105	char hostname[MAXHOSTNAMELEN], s[BUFSIZ], s1[BUFSIZ];
106
107	openlog("lock", 0, LOG_AUTH);
108
109	pam_err = PAM_SYSTEM_ERR; /* pacify GCC */
110
111	sectimeout = TIMEOUT;
112	pamh = NULL;
113	pw = NULL;
114	usemine = 0;
115	no_timeout = 0;
116	vtylock = 0;
117	while ((ch = getopt(argc, argv, "npt:v")) != -1)
118		switch((char)ch) {
119		case 't':
120			if ((sectimeout = atoi(optarg)) <= 0)
121				errx(1, "illegal timeout value");
122			break;
123		case 'p':
124			usemine = 1;
125			if (!(pw = getpwuid(getuid())))
126				errx(1, "unknown uid %d", getuid());
127			break;
128		case 'n':
129			no_timeout = 1;
130			break;
131		case 'v':
132			vtylock = 1;
133			break;
134		case '?':
135		default:
136			usage();
137		}
138	timeout.tv_sec = sectimeout * 60;
139
140	if (!usemine) {	/* -p with PAM or S/key needs privs */
141		/* discard privs */
142		if (setuid(getuid()) != 0)
143			errx(1, "setuid failed");
144	}
145
146	if (tcgetattr(0, &tty))		/* get information for header */
147		exit(1);
148	gethostname(hostname, sizeof(hostname));
149	if (!(ttynam = ttyname(0)))
150		errx(1, "not a terminal?");
151	if (strncmp(ttynam, _PATH_DEV, strlen(_PATH_DEV)) == 0)
152		ttynam += strlen(_PATH_DEV);
153	timval = time(NULL);
154	nexttime = timval + (sectimeout * 60);
155	timp = localtime(&timval);
156	ap = asctime(timp);
157	tzn = timp->tm_zone;
158
159	(void)signal(SIGINT, quit);
160	(void)signal(SIGQUIT, quit);
161	ntty = tty; ntty.c_lflag &= ~ECHO;
162	(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &ntty);
163
164	if (usemine) {
165		pam_err = pam_start("lock", pw->pw_name, &pamc, &pamh);
166		if (pam_err != PAM_SUCCESS)
167			err(1, "pam_start: %s", pam_strerror(NULL, pam_err));
168	} else {
169		/* get key and check again */
170		(void)printf("Key: ");
171		if (!fgets(s, sizeof(s), stdin) || *s == '\n')
172			quit(0);
173		(void)printf("\nAgain: ");
174		/*
175		 * Don't need EOF test here, if we get EOF, then s1 != s
176		 * and the right things will happen.
177		 */
178		(void)fgets(s1, sizeof(s1), stdin);
179		(void)putchar('\n');
180		if (strcmp(s1, s)) {
181			(void)printf("\07lock: passwords didn't match.\n");
182			(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
183			exit(1);
184		}
185		s[0] = '\0';
186	}
187
188	/* set signal handlers */
189	(void)signal(SIGINT, hi);
190	(void)signal(SIGQUIT, hi);
191	(void)signal(SIGTSTP, hi);
192	(void)signal(SIGALRM, bye);
193
194	ntimer.it_interval = zerotime;
195	ntimer.it_value = timeout;
196	if (!no_timeout)
197		setitimer(ITIMER_REAL, &ntimer, &otimer);
198	if (vtylock) {
199		/*
200		 * If this failed, we want to err out; warn isn't good
201		 * enough, since we don't want the user to think that
202		 * everything is nice and locked because they got a
203		 * "Key:" prompt.
204		 */
205		if (ioctl(0, VT_LOCKSWITCH, &vtylock) == -1) {
206			(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
207			err(1, "locking vty");
208		}
209		vtyunlock = 0x2;
210	}
211
212	/* header info */
213	if (pw != NULL)
214		(void)printf("lock: %s using %s on %s.", pw->pw_name,
215		    ttynam, hostname);
216	else
217		(void)printf("lock: %s on %s.", ttynam, hostname);
218	if (no_timeout)
219		(void)printf(" no timeout.");
220	else
221		(void)printf(" timeout in %d minute%s.", sectimeout,
222		    sectimeout != 1 ? "s" : "");
223	if (vtylock)
224		(void)printf(" vty locked.");
225	(void)printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19);
226
227	failures = 0;
228
229	for (;;) {
230		if (usemine) {
231			pam_err = pam_authenticate(pamh, 0);
232			if (pam_err == PAM_SUCCESS)
233				break;
234
235			if (pam_err != PAM_AUTH_ERR &&
236			    pam_err != PAM_USER_UNKNOWN &&
237			    pam_err != PAM_MAXTRIES) {
238				syslog(LOG_ERR, "pam_authenticate: %s",
239				    pam_strerror(pamh, pam_err));
240			}
241
242			goto tryagain;
243		}
244		(void)printf("Key: ");
245		if (!fgets(s, sizeof(s), stdin)) {
246			clearerr(stdin);
247			hi(0);
248			goto tryagain;
249		}
250		if (!strcmp(s, s1))
251			break;
252		(void)printf("\07\n");
253	    	failures++;
254		if (getuid() == 0)
255	    	    syslog(LOG_NOTICE, "%d ROOT UNLOCK FAILURE%s (%s on %s)",
256			failures, failures > 1 ? "S": "", ttynam, hostname);
257tryagain:
258		if (tcgetattr(0, &ntty) && (errno != EINTR))
259			exit(1);
260		sleep(1);		/* to discourage guessing */
261	}
262	if (getuid() == 0)
263		syslog(LOG_NOTICE, "ROOT UNLOCK ON hostname %s port %s",
264		    hostname, ttynam);
265	if (usemine)
266		(void)pam_end(pamh, pam_err);
267	quit(0);
268	return(0); /* not reached */
269}
270
271
272static void
273usage(void)
274{
275	(void)fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
276	exit(1);
277}
278
279static void
280hi(int signo __unused)
281{
282	time_t timval;
283
284	timval = time(NULL);
285	(void)printf("lock: type in the unlock key. ");
286	if (no_timeout) {
287		(void)putchar('\n');
288	} else {
289		(void)printf("timeout in %jd:%jd minutes\n",
290		    (intmax_t)(nexttime - timval) / 60,
291		    (intmax_t)(nexttime - timval) % 60);
292	}
293}
294
295static void
296quit(int signo __unused)
297{
298	(void)putchar('\n');
299	(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
300	if (vtyunlock)
301		(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
302	exit(0);
303}
304
305static void
306bye(int signo __unused)
307{
308	if (!no_timeout) {
309		(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
310		if (vtyunlock)
311			(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
312		(void)printf("lock: timeout\n");
313		exit(1);
314	}
315}
316