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
36 static 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
43 static 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
81 static void quit(int);
82 static void bye(int);
83 static void hi(int);
84 static void usage(void);
85
86 static struct timeval timeout;
87 static struct timeval zerotime;
88 static struct termios tty, ntty;
89 static long nexttime; /* keep the timeout time */
90 static int no_timeout; /* lock terminal forever */
91 static int vtyunlock; /* Unlock flag and code. */
92
93 /*ARGSUSED*/
94 int
main(int argc,char ** argv)95 main(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);
257 tryagain:
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
272 static void
usage(void)273 usage(void)
274 {
275 (void)fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
276 exit(1);
277 }
278
279 static void
hi(int signo __unused)280 hi(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
295 static void
quit(int signo __unused)296 quit(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
305 static void
bye(int signo __unused)306 bye(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