xref: /freebsd/usr.bin/lock/lock.c (revision 3416500aef140042c64bc149cb1ec6620483bc44)
1 /*
2  * Copyright (c) 1980, 1987, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Bob Toxen.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1980, 1987, 1993\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif /* not lint */
38 
39 #ifndef lint
40 #if 0
41 static char sccsid[] = "@(#)lock.c	8.1 (Berkeley) 6/6/93";
42 #endif
43 #endif /* not lint */
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 /*
48  * Lock a terminal up until the given key is entered or the given
49  * interval times out.
50  *
51  * Timeout interval is by default TIMEOUT, it can be changed with
52  * an argument of the form -time where time is in minutes
53  */
54 
55 #include <sys/param.h>
56 #include <sys/stat.h>
57 #include <sys/signal.h>
58 #include <sys/consio.h>
59 
60 #include <err.h>
61 #include <ctype.h>
62 #include <errno.h>
63 #include <paths.h>
64 #include <pwd.h>
65 #include <stdint.h>
66 #include <stdio.h>
67 #include <stdlib.h>
68 #include <string.h>
69 #include <syslog.h>
70 #include <termios.h>
71 #include <time.h>
72 #include <unistd.h>
73 
74 #define	TIMEOUT	15
75 
76 static void quit(int);
77 static void bye(int);
78 static void hi(int);
79 static void usage(void);
80 
81 static struct timeval	timeout;
82 static struct timeval	zerotime;
83 static struct termios	tty, ntty;
84 static long		nexttime;		/* keep the timeout time */
85 static int		no_timeout;		/* lock terminal forever */
86 static int		vtyunlock;		/* Unlock flag and code. */
87 
88 /*ARGSUSED*/
89 int
90 main(int argc, char **argv)
91 {
92 	struct passwd *pw;
93 	struct itimerval ntimer, otimer;
94 	struct tm *timp;
95 	time_t timval;
96 	int ch, failures, sectimeout, usemine, vtylock;
97 	char *ap, *cryptpw, *mypw, *ttynam, *tzn;
98 	char hostname[MAXHOSTNAMELEN], s[BUFSIZ], s1[BUFSIZ];
99 
100 	openlog("lock", 0, LOG_AUTH);
101 
102 	sectimeout = TIMEOUT;
103 	pw = NULL;
104 	mypw = NULL;
105 	usemine = 0;
106 	no_timeout = 0;
107 	vtylock = 0;
108 	while ((ch = getopt(argc, argv, "npt:v")) != -1)
109 		switch((char)ch) {
110 		case 't':
111 			if ((sectimeout = atoi(optarg)) <= 0)
112 				errx(1, "illegal timeout value");
113 			break;
114 		case 'p':
115 			usemine = 1;
116 			if (!(pw = getpwuid(getuid())))
117 				errx(1, "unknown uid %d", getuid());
118 			mypw = strdup(pw->pw_passwd);
119 			break;
120 		case 'n':
121 			no_timeout = 1;
122 			break;
123 		case 'v':
124 			vtylock = 1;
125 			break;
126 		case '?':
127 		default:
128 			usage();
129 		}
130 	timeout.tv_sec = sectimeout * 60;
131 
132 	/* discard privs */
133 	if (setuid(getuid()) != 0)
134 		errx(1, "setuid failed");
135 
136 	if (tcgetattr(0, &tty))		/* get information for header */
137 		exit(1);
138 	gethostname(hostname, sizeof(hostname));
139 	if (!(ttynam = ttyname(0)))
140 		errx(1, "not a terminal?");
141 	if (strncmp(ttynam, _PATH_DEV, strlen(_PATH_DEV)) == 0)
142 		ttynam += strlen(_PATH_DEV);
143 	timval = time(NULL);
144 	nexttime = timval + (sectimeout * 60);
145 	timp = localtime(&timval);
146 	ap = asctime(timp);
147 	tzn = timp->tm_zone;
148 
149 	(void)signal(SIGINT, quit);
150 	(void)signal(SIGQUIT, quit);
151 	ntty = tty; ntty.c_lflag &= ~ECHO;
152 	(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &ntty);
153 
154 	if (!mypw) {
155 		/* get key and check again */
156 		(void)printf("Key: ");
157 		if (!fgets(s, sizeof(s), stdin) || *s == '\n')
158 			quit(0);
159 		(void)printf("\nAgain: ");
160 		/*
161 		 * Don't need EOF test here, if we get EOF, then s1 != s
162 		 * and the right things will happen.
163 		 */
164 		(void)fgets(s1, sizeof(s1), stdin);
165 		(void)putchar('\n');
166 		if (strcmp(s1, s)) {
167 			(void)printf("\07lock: passwords didn't match.\n");
168 			(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
169 			exit(1);
170 		}
171 		s[0] = '\0';
172 		mypw = s1;
173 	}
174 
175 	/* set signal handlers */
176 	(void)signal(SIGINT, hi);
177 	(void)signal(SIGQUIT, hi);
178 	(void)signal(SIGTSTP, hi);
179 	(void)signal(SIGALRM, bye);
180 
181 	ntimer.it_interval = zerotime;
182 	ntimer.it_value = timeout;
183 	if (!no_timeout)
184 		setitimer(ITIMER_REAL, &ntimer, &otimer);
185 	if (vtylock) {
186 		/*
187 		 * If this failed, we want to err out; warn isn't good
188 		 * enough, since we don't want the user to think that
189 		 * everything is nice and locked because they got a
190 		 * "Key:" prompt.
191 		 */
192 		if (ioctl(0, VT_LOCKSWITCH, &vtylock) == -1) {
193 			(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
194 			err(1, "locking vty");
195 		}
196 		vtyunlock = 0x2;
197 	}
198 
199 	/* header info */
200 	if (pw != NULL)
201 		(void)printf("lock: %s using %s on %s.", pw->pw_name,
202 		    ttynam, hostname);
203 	else
204 		(void)printf("lock: %s on %s.", ttynam, hostname);
205 	if (no_timeout)
206 		(void)printf(" no timeout.");
207 	else
208 		(void)printf(" timeout in %d minute%s.", sectimeout,
209 		    sectimeout != 1 ? "s" : "");
210 	if (vtylock)
211 		(void)printf(" vty locked.");
212 	(void)printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19);
213 
214 	failures = 0;
215 
216 	for (;;) {
217 		(void)printf("Key: ");
218 		if (!fgets(s, sizeof(s), stdin)) {
219 			clearerr(stdin);
220 			hi(0);
221 			goto tryagain;
222 		}
223 		if (usemine) {
224 			s[strlen(s) - 1] = '\0';
225 			cryptpw = crypt(s, mypw);
226 			if (cryptpw == NULL || !strcmp(mypw, cryptpw))
227 				break;
228 		}
229 		else if (!strcmp(s, s1))
230 			break;
231 		(void)printf("\07\n");
232 	    	failures++;
233 		if (getuid() == 0)
234 	    	    syslog(LOG_NOTICE, "%d ROOT UNLOCK FAILURE%s (%s on %s)",
235 			failures, failures > 1 ? "S": "", ttynam, hostname);
236 tryagain:
237 		if (tcgetattr(0, &ntty) && (errno != EINTR))
238 			exit(1);
239 		sleep(1);		/* to discourage guessing */
240 	}
241 	if (getuid() == 0)
242 		syslog(LOG_NOTICE, "ROOT UNLOCK ON hostname %s port %s",
243 		    hostname, ttynam);
244 	quit(0);
245 	return(0); /* not reached */
246 }
247 
248 
249 static void
250 usage(void)
251 {
252 	(void)fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
253 	exit(1);
254 }
255 
256 static void
257 hi(int signo __unused)
258 {
259 	time_t timval;
260 
261 	timval = time(NULL);
262 	(void)printf("lock: type in the unlock key. ");
263 	if (no_timeout) {
264 		(void)putchar('\n');
265 	} else {
266 		(void)printf("timeout in %jd:%jd minutes\n",
267 		    (intmax_t)(nexttime - timval) / 60,
268 		    (intmax_t)(nexttime - timval) % 60);
269 	}
270 }
271 
272 static void
273 quit(int signo __unused)
274 {
275 	(void)putchar('\n');
276 	(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
277 	if (vtyunlock)
278 		(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
279 	exit(0);
280 }
281 
282 static void
283 bye(int signo __unused)
284 {
285 	if (!no_timeout) {
286 		(void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
287 		if (vtyunlock)
288 			(void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
289 		(void)printf("lock: timeout\n");
290 		exit(1);
291 	}
292 }
293