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 /*
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 #include <security/pam_appl.h>
75 #include <security/openpam.h> /* for openpam_ttyconv() */
76
77 #define TIMEOUT 15
78
79 static void quit(int);
80 static void bye(int);
81 static void hi(int);
82 static void usage(void) __dead2;
83
84 static struct timeval timeout;
85 static struct timeval zerotime;
86 static struct termios tty, ntty;
87 static long nexttime; /* keep the timeout time */
88 static int no_timeout; /* lock terminal forever */
89 static int vtyunlock; /* Unlock flag and code. */
90
91 /*ARGSUSED*/
92 int
main(int argc,char ** argv)93 main(int argc, char **argv)
94 {
95 static const struct pam_conv pamc = { &openpam_ttyconv, NULL };
96 pam_handle_t *pamh;
97 struct passwd *pw;
98 struct itimerval ntimer, otimer;
99 struct tm *timp;
100 time_t timval;
101 int ch, failures, pam_err, sectimeout, usemine, vtylock;
102 char *ap, *ttynam, *tzn;
103 char hostname[MAXHOSTNAMELEN], s[BUFSIZ], s1[BUFSIZ];
104
105 openlog("lock", 0, LOG_AUTH);
106
107 pam_err = PAM_SYSTEM_ERR; /* pacify GCC */
108
109 sectimeout = TIMEOUT;
110 pamh = NULL;
111 pw = NULL;
112 usemine = 0;
113 no_timeout = 0;
114 vtylock = 0;
115 while ((ch = getopt(argc, argv, "npt:v")) != -1)
116 switch((char)ch) {
117 case 't':
118 if ((sectimeout = atoi(optarg)) <= 0)
119 errx(1, "illegal timeout value");
120 break;
121 case 'p':
122 usemine = 1;
123 if (!(pw = getpwuid(getuid())))
124 errx(1, "unknown uid %d", getuid());
125 break;
126 case 'n':
127 no_timeout = 1;
128 break;
129 case 'v':
130 vtylock = 1;
131 break;
132 case '?':
133 default:
134 usage();
135 }
136 timeout.tv_sec = sectimeout * 60;
137
138 if (!usemine) { /* -p with PAM or S/key needs privs */
139 /* discard privs */
140 if (setuid(getuid()) != 0)
141 errx(1, "setuid failed");
142 }
143
144 if (tcgetattr(0, &tty)) /* get information for header */
145 exit(1);
146 gethostname(hostname, sizeof(hostname));
147 if (!(ttynam = ttyname(0)))
148 errx(1, "not a terminal?");
149 if (strncmp(ttynam, _PATH_DEV, strlen(_PATH_DEV)) == 0)
150 ttynam += strlen(_PATH_DEV);
151 timval = time(NULL);
152 nexttime = timval + (sectimeout * 60);
153 timp = localtime(&timval);
154 ap = asctime(timp);
155 tzn = timp->tm_zone;
156
157 (void)signal(SIGINT, quit);
158 (void)signal(SIGQUIT, quit);
159 ntty = tty; ntty.c_lflag &= ~ECHO;
160 (void)tcsetattr(0, TCSADRAIN|TCSASOFT, &ntty);
161
162 if (usemine) {
163 pam_err = pam_start("lock", pw->pw_name, &pamc, &pamh);
164 if (pam_err != PAM_SUCCESS)
165 err(1, "pam_start: %s", pam_strerror(NULL, pam_err));
166 } else {
167 /* get key and check again */
168 (void)printf("Key: ");
169 if (!fgets(s, sizeof(s), stdin) || *s == '\n')
170 quit(0);
171 (void)printf("\nAgain: ");
172 /*
173 * Don't need EOF test here, if we get EOF, then s1 != s
174 * and the right things will happen.
175 */
176 (void)fgets(s1, sizeof(s1), stdin);
177 (void)putchar('\n');
178 if (strcmp(s1, s)) {
179 (void)printf("\07lock: passwords didn't match.\n");
180 (void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
181 exit(1);
182 }
183 s[0] = '\0';
184 }
185
186 /* set signal handlers */
187 (void)signal(SIGINT, hi);
188 (void)signal(SIGQUIT, hi);
189 (void)signal(SIGTSTP, hi);
190 (void)signal(SIGALRM, bye);
191
192 ntimer.it_interval = zerotime;
193 ntimer.it_value = timeout;
194 if (!no_timeout)
195 setitimer(ITIMER_REAL, &ntimer, &otimer);
196 if (vtylock) {
197 /*
198 * If this failed, we want to err out; warn isn't good
199 * enough, since we don't want the user to think that
200 * everything is nice and locked because they got a
201 * "Key:" prompt.
202 */
203 if (ioctl(0, VT_LOCKSWITCH, &vtylock) == -1) {
204 (void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
205 err(1, "locking vty");
206 }
207 vtyunlock = 0x2;
208 }
209
210 /* header info */
211 if (pw != NULL)
212 (void)printf("lock: %s using %s on %s.", pw->pw_name,
213 ttynam, hostname);
214 else
215 (void)printf("lock: %s on %s.", ttynam, hostname);
216 if (no_timeout)
217 (void)printf(" no timeout.");
218 else
219 (void)printf(" timeout in %d minute%s.", sectimeout,
220 sectimeout != 1 ? "s" : "");
221 if (vtylock)
222 (void)printf(" vty locked.");
223 (void)printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19);
224
225 failures = 0;
226
227 for (;;) {
228 if (usemine) {
229 pam_err = pam_authenticate(pamh, 0);
230 if (pam_err == PAM_SUCCESS)
231 break;
232
233 if (pam_err != PAM_AUTH_ERR &&
234 pam_err != PAM_USER_UNKNOWN &&
235 pam_err != PAM_MAXTRIES) {
236 syslog(LOG_ERR, "pam_authenticate: %s",
237 pam_strerror(pamh, pam_err));
238 }
239
240 goto tryagain;
241 }
242 (void)printf("Key: ");
243 if (!fgets(s, sizeof(s), stdin)) {
244 clearerr(stdin);
245 hi(0);
246 goto tryagain;
247 }
248 if (!strcmp(s, s1))
249 break;
250 (void)printf("\07\n");
251 failures++;
252 if (getuid() == 0)
253 syslog(LOG_NOTICE, "%d ROOT UNLOCK FAILURE%s (%s on %s)",
254 failures, failures > 1 ? "S": "", ttynam, hostname);
255 tryagain:
256 if (tcgetattr(0, &ntty) && (errno != EINTR))
257 exit(1);
258 sleep(1); /* to discourage guessing */
259 }
260 if (getuid() == 0)
261 syslog(LOG_NOTICE, "ROOT UNLOCK ON hostname %s port %s",
262 hostname, ttynam);
263 if (usemine)
264 (void)pam_end(pamh, pam_err);
265 quit(0);
266 return(0); /* not reached */
267 }
268
269
270 static void
usage(void)271 usage(void)
272 {
273 (void)fprintf(stderr, "usage: lock [-npv] [-t timeout]\n");
274 exit(1);
275 }
276
277 static void
hi(int signo __unused)278 hi(int signo __unused)
279 {
280 time_t timval;
281
282 timval = time(NULL);
283 (void)printf("lock: type in the unlock key. ");
284 if (no_timeout) {
285 (void)putchar('\n');
286 } else {
287 (void)printf("timeout in %jd:%jd minutes\n",
288 (intmax_t)(nexttime - timval) / 60,
289 (intmax_t)(nexttime - timval) % 60);
290 }
291 }
292
293 static void
quit(int signo __unused)294 quit(int signo __unused)
295 {
296 (void)putchar('\n');
297 (void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
298 if (vtyunlock)
299 (void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
300 exit(0);
301 }
302
303 static void
bye(int signo __unused)304 bye(int signo __unused)
305 {
306 if (!no_timeout) {
307 (void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty);
308 if (vtyunlock)
309 (void)ioctl(0, VT_LOCKSWITCH, &vtyunlock);
310 (void)printf("lock: timeout\n");
311 exit(1);
312 }
313 }
314