xref: /openbsd/usr.bin/lock/lock.c (revision 9b7c3dbb)
1 /*	$OpenBSD: lock.c,v 1.33 2016/05/28 16:11:10 tedu Exp $	*/
2 /*	$NetBSD: lock.c,v 1.8 1996/05/07 18:32:31 jtc Exp $	*/
3 
4 /*
5  * Copyright (c) 1980, 1987, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Bob Toxen.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 /*
37  * Lock a terminal up until the given key is entered, until the root
38  * password is entered, or the given interval times out.
39  *
40  * Timeout interval is by default TIMEOUT, it can be changed with
41  * an argument of the form -time where time is in minutes
42  */
43 
44 #include <sys/stat.h>
45 #include <sys/time.h>
46 #include <signal.h>
47 
48 #include <ctype.h>
49 #include <err.h>
50 #include <pwd.h>
51 #include <readpassphrase.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <termios.h>
56 #include <unistd.h>
57 #include <limits.h>
58 
59 #include <login_cap.h>
60 #include <bsd_auth.h>
61 
62 #define	TIMEOUT	15
63 
64 void bye(int);
65 void hi(int);
66 
67 struct timeval	timeout;
68 struct timeval	zerotime;
69 time_t	nexttime;			/* keep the timeout time */
70 int	no_timeout;			/* lock terminal forever */
71 
72 extern	char *__progname;
73 
74 /*ARGSUSED*/
75 int
76 main(int argc, char *argv[])
77 {
78 	char hostname[HOST_NAME_MAX+1], s[BUFSIZ], s1[BUFSIZ], date[256];
79 	char *p, *style, *nstyle, *ttynam;
80 	struct itimerval ntimer, otimer;
81 	int ch, sectimeout, usemine, cnt, tries = 10, backoff = 3;
82 	const char *errstr;
83 	struct passwd *pw;
84 	struct tm *timp;
85 	time_t curtime;
86 	login_cap_t *lc;
87 
88 	sectimeout = TIMEOUT;
89 	style = NULL;
90 	usemine = 0;
91 	no_timeout = 0;
92 
93 	if (pledge("stdio rpath wpath getpw tty proc exec", NULL) == -1)
94 		err(1, "pledge");
95 
96 	if (!(pw = getpwuid(getuid())))
97 		errx(1, "unknown uid %u.", getuid());
98 
99 	lc = login_getclass(pw->pw_class);
100 	if (lc != NULL) {
101 		/*
102 		 * We allow "login-tries" attempts to login but start
103 		 * slowing down after "login-backoff" attempts.
104 		 */
105 		tries = (int)login_getcapnum(lc, "login-tries", 10, 10);
106 		backoff = (int)login_getcapnum(lc, "login-backoff", 3, 3);
107 	}
108 
109 	while ((ch = getopt(argc, argv, "a:npt:")) != -1) {
110 		switch (ch) {
111 		case 'a':
112 			if (lc) {
113 				style = login_getstyle(lc, optarg, "auth-lock");
114 				if (style == NULL)
115 					errx(1,
116 					    "invalid authentication style: %s",
117 					    optarg);
118 			}
119 			usemine = 1;
120 			break;
121 		case 't':
122 			sectimeout = (int)strtonum(optarg, 1, INT_MAX, &errstr);
123 			if (errstr)
124 				errx(1, "timeout %s: %s", errstr, optarg);
125 			break;
126 		case 'p':
127 			usemine = 1;
128 			break;
129 		case 'n':
130 			no_timeout = 1;
131 			break;
132 		default:
133 			(void)fprintf(stderr,
134 			    "usage: %s [-np] [-a style] [-t timeout]\n",
135 			    __progname);
136 			exit(1);
137 		}
138 	}
139 	timeout.tv_sec = sectimeout * 60;
140 
141 	gethostname(hostname, sizeof(hostname));
142 	if (usemine && lc == NULL)
143 		errx(1, "login class not found");
144 	if (!(ttynam = ttyname(STDIN_FILENO)))
145 		errx(1, "not a terminal?");
146 	curtime = time(NULL);
147 	nexttime = curtime + (sectimeout * 60);
148 	timp = localtime(&curtime);
149 	strftime(date, sizeof(date), "%c", timp);
150 
151 	if (!usemine) {
152 		/* get key and check again */
153 		if (!readpassphrase("Key: ", s, sizeof(s), RPP_ECHO_OFF) ||
154 		    *s == '\0')
155 			exit(0);
156 		/*
157 		 * Don't need EOF test here, if we get EOF, then s1 != s
158 		 * and the right things will happen.
159 		 */
160 		(void)readpassphrase("Again: ", s1, sizeof(s1), RPP_ECHO_OFF);
161 		if (strcmp(s1, s)) {
162 			warnx("\apasswords didn't match.");
163 			exit(1);
164 		}
165 		s[0] = '\0';
166 	}
167 
168 	/* set signal handlers */
169 	(void)signal(SIGINT, hi);
170 	(void)signal(SIGQUIT, hi);
171 	(void)signal(SIGTSTP, hi);
172 	(void)signal(SIGALRM, bye);
173 
174 	ntimer.it_interval = zerotime;
175 	ntimer.it_value = timeout;
176 	if (!no_timeout)
177 		setitimer(ITIMER_REAL, &ntimer, &otimer);
178 
179 	/* header info */
180 	if (no_timeout) {
181 		(void)fprintf(stderr,
182 		    "%s: %s on %s. no timeout\ntime now is %s\n",
183 		    __progname, ttynam, hostname, date);
184 	} else {
185 		(void)fprintf(stderr,
186 		    "%s: %s on %s. timeout in %d minutes\ntime now is %s\n",
187 		    __progname, ttynam, hostname, sectimeout, date);
188 	}
189 
190 	for (cnt = 0;;) {
191 		if (!readpassphrase("Key: ", s, sizeof(s), RPP_ECHO_OFF) ||
192 		    *s == '\0') {
193 			hi(0);
194 			continue;
195 		}
196 		if (usemine) {
197 			/*
198 			 * If user entered 's/key' or the style specified via
199 			 * the '-a' argument, auth_userokay() will prompt
200 			 * for a new password.  Otherwise, use what we have.
201 			 */
202 			if ((strcmp(s, "s/key") == 0 &&
203 			    (nstyle = login_getstyle(lc, "skey", "auth-lock")))
204 			    || ((nstyle = style) && strcmp(s, nstyle) == 0))
205 				p = NULL;
206 			else
207 				p = s;
208 			if (auth_userokay(pw->pw_name, nstyle, "auth-lock", p))
209 				break;
210 		} else if (strcmp(s, s1) == 0)
211 			break;
212 		(void)putc('\a', stderr);
213 		cnt %= tries;
214 		if (++cnt > backoff) {
215 			sigset_t set, oset;
216 			sigfillset(&set);
217 			sigprocmask(SIG_BLOCK, &set, &oset);
218 			sleep((u_int)((cnt - backoff) * tries / 2));
219 			sigprocmask(SIG_SETMASK, &oset, NULL);
220 		}
221 	}
222 
223 	exit(0);
224 }
225 
226 /*ARGSUSED*/
227 void
228 hi(int signo)
229 {
230 	char buf[1024], buf2[1024];
231 	time_t left;
232 
233 	if (no_timeout)
234 		buf2[0] = '\0';
235 	else {
236 		left = nexttime - time(NULL);
237 		(void)snprintf(buf2, sizeof buf2, " timeout in %lld:%d minutes",
238 		    (long long)(left / 60), (int)(left % 60));
239 	}
240 	(void)snprintf(buf, sizeof buf, "%s: type in the unlock key.%s\n",
241 	    __progname, buf2);
242 	(void) write(STDERR_FILENO, buf, strlen(buf));
243 }
244 
245 /*ARGSUSED*/
246 void
247 bye(int signo)
248 {
249 
250 	if (!no_timeout)
251 		warnx("timeout");
252 	_exit(1);
253 }
254