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 /* 36 * Lock a terminal up until the given key is entered or the given 37 * interval times out. 38 * 39 * Timeout interval is by default TIMEOUT, it can be changed with 40 * an argument of the form -time where time is in minutes 41 */ 42 43 #include <sys/param.h> 44 #include <sys/stat.h> 45 #include <sys/signal.h> 46 #include <sys/consio.h> 47 48 #include <err.h> 49 #include <ctype.h> 50 #include <errno.h> 51 #include <paths.h> 52 #include <pwd.h> 53 #include <stdint.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <syslog.h> 58 #include <termios.h> 59 #include <time.h> 60 #include <unistd.h> 61 62 #include <security/pam_appl.h> 63 #include <security/openpam.h> /* for openpam_ttyconv() */ 64 65 #define TIMEOUT 15 66 67 static void quit(int); 68 static void bye(int); 69 static void hi(int); 70 static void usage(void) __dead2; 71 72 static struct timeval timeout; 73 static struct timeval zerotime; 74 static struct termios tty, ntty; 75 static long nexttime; /* keep the timeout time */ 76 static int no_timeout; /* lock terminal forever */ 77 static int vtyunlock; /* Unlock flag and code. */ 78 79 /*ARGSUSED*/ 80 int 81 main(int argc, char **argv) 82 { 83 static const struct pam_conv pamc = { &openpam_ttyconv, NULL }; 84 pam_handle_t *pamh; 85 struct passwd *pw; 86 struct itimerval ntimer, otimer; 87 struct tm *timp; 88 time_t timval; 89 int ch, failures, pam_err, sectimeout, usemine, vtylock; 90 char *ap, *ttynam, *tzn; 91 char hostname[MAXHOSTNAMELEN], s[BUFSIZ], s1[BUFSIZ]; 92 93 openlog("lock", 0, LOG_AUTH); 94 95 pam_err = PAM_SYSTEM_ERR; /* pacify GCC */ 96 97 sectimeout = TIMEOUT; 98 pamh = NULL; 99 pw = NULL; 100 usemine = 0; 101 no_timeout = 0; 102 vtylock = 0; 103 while ((ch = getopt(argc, argv, "npt:v")) != -1) 104 switch((char)ch) { 105 case 't': 106 if ((sectimeout = atoi(optarg)) <= 0) 107 errx(1, "illegal timeout value"); 108 break; 109 case 'p': 110 usemine = 1; 111 if (!(pw = getpwuid(getuid()))) 112 errx(1, "unknown uid %d", getuid()); 113 break; 114 case 'n': 115 no_timeout = 1; 116 break; 117 case 'v': 118 vtylock = 1; 119 break; 120 case '?': 121 default: 122 usage(); 123 } 124 timeout.tv_sec = sectimeout * 60; 125 126 if (!usemine) { /* -p with PAM or S/key needs privs */ 127 /* discard privs */ 128 if (setuid(getuid()) != 0) 129 errx(1, "setuid failed"); 130 } 131 132 if (tcgetattr(0, &tty)) /* get information for header */ 133 exit(1); 134 gethostname(hostname, sizeof(hostname)); 135 if (!(ttynam = ttyname(0))) 136 errx(1, "not a terminal?"); 137 if (strncmp(ttynam, _PATH_DEV, strlen(_PATH_DEV)) == 0) 138 ttynam += strlen(_PATH_DEV); 139 timval = time(NULL); 140 nexttime = timval + (sectimeout * 60); 141 timp = localtime(&timval); 142 ap = asctime(timp); 143 tzn = timp->tm_zone; 144 145 (void)signal(SIGINT, quit); 146 (void)signal(SIGQUIT, quit); 147 ntty = tty; ntty.c_lflag &= ~ECHO; 148 (void)tcsetattr(0, TCSADRAIN|TCSASOFT, &ntty); 149 150 if (usemine) { 151 pam_err = pam_start("lock", pw->pw_name, &pamc, &pamh); 152 if (pam_err != PAM_SUCCESS) 153 err(1, "pam_start: %s", pam_strerror(NULL, pam_err)); 154 } else { 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 } 173 174 /* set signal handlers */ 175 (void)signal(SIGINT, hi); 176 (void)signal(SIGQUIT, hi); 177 (void)signal(SIGTSTP, hi); 178 (void)signal(SIGALRM, bye); 179 180 ntimer.it_interval = zerotime; 181 ntimer.it_value = timeout; 182 if (!no_timeout) 183 setitimer(ITIMER_REAL, &ntimer, &otimer); 184 if (vtylock) { 185 /* 186 * If this failed, we want to err out; warn isn't good 187 * enough, since we don't want the user to think that 188 * everything is nice and locked because they got a 189 * "Key:" prompt. 190 */ 191 if (ioctl(0, VT_LOCKSWITCH, &vtylock) == -1) { 192 (void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty); 193 err(1, "locking vty"); 194 } 195 vtyunlock = 0x2; 196 } 197 198 /* header info */ 199 if (pw != NULL) 200 (void)printf("lock: %s using %s on %s.", pw->pw_name, 201 ttynam, hostname); 202 else 203 (void)printf("lock: %s on %s.", ttynam, hostname); 204 if (no_timeout) 205 (void)printf(" no timeout."); 206 else 207 (void)printf(" timeout in %d minute%s.", sectimeout, 208 sectimeout != 1 ? "s" : ""); 209 if (vtylock) 210 (void)printf(" vty locked."); 211 (void)printf("\ntime now is %.20s%s%s", ap, tzn, ap + 19); 212 213 failures = 0; 214 215 for (;;) { 216 if (usemine) { 217 pam_err = pam_authenticate(pamh, 0); 218 if (pam_err == PAM_SUCCESS) 219 break; 220 221 if (pam_err != PAM_AUTH_ERR && 222 pam_err != PAM_USER_UNKNOWN && 223 pam_err != PAM_MAXTRIES) { 224 syslog(LOG_ERR, "pam_authenticate: %s", 225 pam_strerror(pamh, pam_err)); 226 } 227 228 goto tryagain; 229 } 230 (void)printf("Key: "); 231 if (!fgets(s, sizeof(s), stdin)) { 232 clearerr(stdin); 233 hi(0); 234 goto tryagain; 235 } 236 if (!strcmp(s, s1)) 237 break; 238 (void)printf("\07\n"); 239 failures++; 240 if (getuid() == 0) 241 syslog(LOG_NOTICE, "%d ROOT UNLOCK FAILURE%s (%s on %s)", 242 failures, failures > 1 ? "S": "", ttynam, hostname); 243 tryagain: 244 if (tcgetattr(0, &ntty) && (errno != EINTR)) 245 exit(1); 246 sleep(1); /* to discourage guessing */ 247 } 248 if (getuid() == 0) 249 syslog(LOG_NOTICE, "ROOT UNLOCK ON hostname %s port %s", 250 hostname, ttynam); 251 if (usemine) 252 (void)pam_end(pamh, pam_err); 253 quit(0); 254 return(0); /* not reached */ 255 } 256 257 258 static void 259 usage(void) 260 { 261 (void)fprintf(stderr, "usage: lock [-npv] [-t timeout]\n"); 262 exit(1); 263 } 264 265 static void 266 hi(int signo __unused) 267 { 268 time_t timval; 269 270 timval = time(NULL); 271 (void)printf("lock: type in the unlock key. "); 272 if (no_timeout) { 273 (void)putchar('\n'); 274 } else { 275 (void)printf("timeout in %jd:%jd minutes\n", 276 (intmax_t)(nexttime - timval) / 60, 277 (intmax_t)(nexttime - timval) % 60); 278 } 279 } 280 281 static void 282 quit(int signo __unused) 283 { 284 (void)putchar('\n'); 285 (void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty); 286 if (vtyunlock) 287 (void)ioctl(0, VT_LOCKSWITCH, &vtyunlock); 288 exit(0); 289 } 290 291 static void 292 bye(int signo __unused) 293 { 294 if (!no_timeout) { 295 (void)tcsetattr(0, TCSADRAIN|TCSASOFT, &tty); 296 if (vtyunlock) 297 (void)ioctl(0, VT_LOCKSWITCH, &vtyunlock); 298 (void)printf("lock: timeout\n"); 299 exit(1); 300 } 301 } 302