usr.bin/lock/lock.c

   1 /*      $NetBSD: lock.c,v 1.30 2008/07/21 14:19:23 lukem Exp $  */
   2
   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 #include <sys/cdefs.h>
  36 #ifndef lint
  37 __COPYRIGHT("@(#) Copyright (c) 1980, 1987, 1993\
  38  The Regents of the University of California.  All rights reserved.");
  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 __RCSID("$NetBSD: lock.c,v 1.30 2008/07/21 14:19:23 lukem Exp $");
  46 #endif /* not lint */
  47
  48 /*
  49  * Lock a terminal up until the given key is entered, until the root
  50  * password is entered, or the given interval times out.
  51  *
  52  * Timeout interval is by default TIMEOUT, it can be changed with
  53  * an argument of the form -time where time is in minutes
  54  */
  55
  56 #include <sys/param.h>
  57 #include <sys/stat.h>
  58 #include <sys/time.h>
  59 #include <signal.h>
  60
  61 #include <err.h>
  62 #include <pwd.h>
  63 #include <errno.h>
  64 #include <stdio.h>
  65 #include <stdlib.h>
  66 #include <string.h>
  67 #include <termios.h>
  68 #include <time.h>
  69 #include <unistd.h>
  70
  71 #ifdef USE_PAM
  72 #include <security/pam_appl.h>
  73 #include <security/openpam.h>   /* for openpam_ttyconv() */
  74 #endif
  75
  76 #ifdef SKEY
  77 #include <skey.h>
  78 #endif
  79
  80
  81 #define TIMEOUT 15
  82
  83 int     main(int, char **);
  84
  85 static void     bye(int) __dead;
  86 static void     hi(int);
  87 static void     quit(int) __dead;
  88 #ifdef SKEY
  89 static int      skey_auth(const char *);
  90 #endif
  91
  92 static struct timeval   timeout;
  93 static struct timeval   zerotime;
  94 static struct termios   tty, ntty;
  95 static int      notimeout;                      /* no timeout at all */
  96 static long     nexttime;                       /* keep the timeout time */
  97
  98 int
  99 main(int argc, char **argv)
 100 {
 101         struct passwd *pw;
 102         struct timeval timval;
 103         struct itimerval ntimer, otimer;
 104         struct tm *timp;
 105         time_t curtime;
 106         int ch, usemine;
 107         long sectimeout;
 108         char *ap, *mypw, *ttynam;
 109         const char *tzn;
 110         uid_t uid = getuid();
 111         char hostname[MAXHOSTNAMELEN + 1], s[BUFSIZ], s1[BUFSIZ];
 112 #ifdef USE_PAM
 113         pam_handle_t *pamh = NULL;
 114         static const struct pam_conv pamc = { &openpam_ttyconv, NULL };
 115         int pam_err;
 116 #endif
 117
 118         if ((pw = getpwuid(getuid())) == NULL)
 119                 errx(1, "unknown uid %lu.", (u_long)uid);
 120
 121         notimeout = 0;
 122         sectimeout = TIMEOUT;
 123         mypw = NULL;
 124         usemine = 0;
 125
 126         while ((ch = getopt(argc, argv, "npt:")) != -1)
 127                 switch ((char)ch) {
 128                 case 'n':
 129                         notimeout = 1;
 130                         break;
 131                 case 't':
 132                         errno = 0;
 133                         if (((sectimeout = strtol(optarg, &ap, 0)) == LONG_MAX
 134                             || sectimeout == LONG_MIN)
 135                             && errno == ERANGE)
 136                                 err(1, "illegal timeout value: %s", optarg);
 137                         if (optarg == ap || *ap || sectimeout <= 0)
 138                                 errx(1, "illegal timeout value: %s", optarg);
 139                         if (sectimeout >= INT_MAX / 60)
 140                                 errx(1, "too large timeout value: %ld",
 141                                     sectimeout);
 142                         break;
 143                 case 'p':
 144                         usemine = 1;
 145 #ifndef USE_PAM
 146                         mypw = strdup(pw->pw_passwd);
 147                         if (!mypw)
 148                                 err(1, "strdup");
 149 #endif
 150                         break;
 151                 case '?':
 152                 default:
 153                         (void)fprintf(stderr,
 154                             "usage: %s [-np] [-t timeout]\n", getprogname());
 155                         exit(1);
 156                 }
 157
 158 #if defined(USE_PAM) || defined(SKEY)
 159         if (! usemine) {        /* -p with PAM or S/key needs privs */
 160 #endif
 161         if (setuid(uid) == -1)  /* discard privs */
 162                 err(1, "setuid failed");
 163 #if defined(USE_PAM) || defined(SKEY)
 164         }
 165 #endif
 166
 167         timeout.tv_sec = (int)sectimeout * 60;
 168
 169         if (tcgetattr(STDIN_FILENO, &tty) < 0)  /* get information for header */
 170                 err(1, "tcgetattr failed");
 171         gethostname(hostname, sizeof(hostname));
 172         hostname[sizeof(hostname) - 1] = '\0';
 173         if (!(ttynam = ttyname(STDIN_FILENO)))
 174                 err(1, "ttyname failed");
 175         if (gettimeofday(&timval, NULL) == -1)
 176                 err(1, "gettimeofday failed");
 177         curtime = timval.tv_sec;
 178         nexttime = timval.tv_sec + ((int)sectimeout * 60);
 179         timp = localtime(&curtime);
 180         ap = asctime(timp);
 181 #ifdef __SVR4
 182         tzn = tzname[0];
 183 #else
 184         tzn = timp->tm_zone;
 185 #endif
 186
 187         if (signal(SIGINT, quit) == SIG_ERR)
 188                 err(1, "signal failed");
 189         if (signal(SIGQUIT, quit) == SIG_ERR)
 190                 err(1, "signal failed");
 191         ntty = tty; ntty.c_lflag &= ~ECHO;
 192         if (tcsetattr(STDIN_FILENO, TCSADRAIN, &ntty) == -1)
 193                 err(1, "tcsetattr");
 194
 195         if (!usemine) {
 196                 /* get key and check again */
 197                 (void)printf("Key: ");
 198                 if (!fgets(s, sizeof(s), stdin) || *s == '\n')
 199                         quit(0);
 200                 (void)printf("\nAgain: ");
 201                 /*
 202                  * Don't need EOF test here, if we get EOF, then s1 != s
 203                  * and the right things will happen.
 204                  */
 205                 (void)fgets(s1, sizeof(s1), stdin);
 206                 (void)putchar('\n');
 207                 if (strcmp(s1, s)) {
 208                         (void)printf("\alock: passwords didn't match.\n");
 209                         (void)tcsetattr(STDIN_FILENO, TCSADRAIN, &tty);
 210                         exit(1);
 211                 }
 212                 s[0] = '\0';
 213                 mypw = s1;
 214         }
 215 #ifdef USE_PAM
 216         if (usemine) {
 217                 pam_err = pam_start("lock", pw->pw_name, &pamc, &pamh);
 218                 if (pam_err != PAM_SUCCESS)
 219                         err(1, "pam_start: %s", pam_strerror(NULL, pam_err));
 220         }
 221 #endif
 222
 223         /* set signal handlers */
 224         if (signal(SIGINT, hi) == SIG_ERR)
 225                 err(1, "signal failed");
 226         if (signal(SIGQUIT, hi) == SIG_ERR)
 227                 err(1, "signal failed");
 228         if (signal(SIGTSTP, hi) == SIG_ERR)
 229                 err(1, "signal failed");
 230
 231         if (notimeout) {
 232                 if (signal(SIGALRM, hi) == SIG_ERR)
 233                         err(1, "signal failed");
 234                 (void)printf("lock: %s on %s.  no timeout.\n"
 235                     "time now is %.20s%s%s",
 236                     ttynam, hostname, ap, tzn, ap + 19);
 237         }
 238         else {
 239                 if (signal(SIGALRM, bye) == SIG_ERR)
 240                         err(1, "signal failed");
 241
 242                 ntimer.it_interval = zerotime;
 243                 ntimer.it_value = timeout;
 244                 if (setitimer(ITIMER_REAL, &ntimer, &otimer) == -1)
 245                         err(1, "setitimer failed");
 246
 247                 /* header info */
 248                 (void)printf("lock: %s on %s. timeout in %ld minutes\n"
 249                     "time now is %.20s%s%s",
 250                     ttynam, hostname, sectimeout, ap, tzn, ap + 19);
 251         }
 252
 253         for (;;) {
 254 #ifdef USE_PAM
 255                 if (usemine) {
 256                         pam_err = pam_authenticate(pamh, 0);
 257                         if (pam_err == PAM_SUCCESS)
 258                                 break;
 259                         goto tryagain;
 260                 }
 261 #endif
 262                 (void)printf("Key: ");
 263                 if (!fgets(s, sizeof(s), stdin)) {
 264                         clearerr(stdin);
 265                         hi(0);
 266                         goto tryagain;
 267                 }
 268 #ifndef USE_PAM
 269                 if (usemine) {
 270                         s[strlen(s) - 1] = '\0';
 271 #ifdef SKEY
 272                         if (strcasecmp(s, "s/key") == 0) {
 273                                 if (skey_auth(pw->pw_name))
 274                                         break;
 275                         }
 276 #endif
 277                         if (!strcmp(mypw, crypt(s, mypw)))
 278                                 break;
 279                 }
 280                 else
 281 #endif
 282                         if (!strcmp(s, s1))
 283                                 break;
 284                 (void)printf("\a\n");
 285  tryagain:
 286                 if (tcsetattr(STDIN_FILENO, TCSADRAIN, &ntty) == -1
 287                     && errno != EINTR)
 288                         err(1, "tcsetattr failed");
 289         }
 290 #ifdef USE_PAM
 291         if (usemine) {
 292                 (void)pam_end(pamh, pam_err);
 293         }
 294 #endif
 295         quit(0);
 296         /* NOTREACHED */
 297         return 0;
 298 }
 299
 300 #ifdef SKEY
 301 /*
 302  * We can't use libskey's skey_authenticate() since it
 303  * handles signals in a way that's inappropriate
 304  * for our needs. Instead we roll our own.
 305  */
 306 static int
 307 skey_auth(const char *user)
 308 {
 309         char s[128];
 310         const char *ask;
 311         int ret = 0;
 312
 313         if (!skey_haskey(user) && (ask = skey_keyinfo(user))) {
 314                 (void)printf("\n[%s]\nResponse: ", ask);
 315                 if (!fgets(s, sizeof(s), stdin) || *s == '\n')
 316                         clearerr(stdin);
 317                 else {
 318                         s[strlen(s) - 1] = '\0';
 319                         if (skey_passcheck(user, s) != -1)
 320                                 ret = 1;
 321                 }
 322         } else
 323                 (void)printf("Sorry, you have no s/key.\n");
 324         return ret;
 325 }
 326 #endif
 327
 328 static void
 329 hi(dummy)
 330         int dummy;
 331 {
 332         struct timeval timval;
 333
 334         if (notimeout)
 335                 (void)printf("lock: type in the unlock key.\n");
 336         else {
 337                 if (gettimeofday(&timval, NULL) == -1)
 338                         err(1, "gettimeofday failed");
 339                 (void)printf("lock: type in the unlock key. "
 340                     "timeout in %lld:%lld minutes\n",
 341                     (long long)(nexttime - timval.tv_sec) / 60,
 342                     (long long)(nexttime - timval.tv_sec) % 60);
 343         }
 344 }
 345
 346 static void
 347 quit(int dummy)
 348 {
 349         (void)putchar('\n');
 350         (void)tcsetattr(STDIN_FILENO, TCSADRAIN, &tty);
 351         exit(0);
 352 }
 353
 354 static void
 355 bye(int dummy)
 356 {
 357         (void)tcsetattr(STDIN_FILENO, TCSADRAIN, &tty);
 358         (void)printf("lock: timeout\n");
 359         exit(1);
 360 }