1 /*- 2 * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#)login.c 8.4 (Berkeley) 4/2/94 34 * $FreeBSD: src/usr.bin/login/login.c,v 1.51.2.15 2003/04/29 14:10:41 des Exp $ 35 * $DragonFly: src/usr.bin/login/login.c,v 1.4 2003/11/03 19:31:30 eirikn Exp $ 36 */ 37 38 #if 0 39 static char copyright[] = 40 "@(#) Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994\n\ 41 The Regents of the University of California. All rights reserved.\n"; 42 #endif 43 44 /* 45 * login [ name ] 46 * login -h hostname (for telnetd, etc.) 47 * login -f name (for pre-authenticated login: datakit, xterm, etc.) 48 */ 49 50 #include <sys/copyright.h> 51 #include <sys/param.h> 52 #include <sys/stat.h> 53 #include <sys/socket.h> 54 #include <sys/time.h> 55 #include <sys/resource.h> 56 #include <sys/file.h> 57 #include <netinet/in.h> 58 #include <arpa/inet.h> 59 60 #include <err.h> 61 #include <errno.h> 62 #include <grp.h> 63 #include <libutil.h> 64 #include <login_cap.h> 65 #include <netdb.h> 66 #include <pwd.h> 67 #include <setjmp.h> 68 #include <signal.h> 69 #include <stdio.h> 70 #include <stdlib.h> 71 #include <string.h> 72 #include <syslog.h> 73 #include <ttyent.h> 74 #include <unistd.h> 75 #include <utmp.h> 76 77 #ifdef USE_PAM 78 #include <security/pam_appl.h> 79 #include <security/pam_misc.h> 80 #include <sys/wait.h> 81 #endif /* USE_PAM */ 82 83 #include "pathnames.h" 84 85 /* wrapper for KAME-special getnameinfo() */ 86 #ifndef NI_WITHSCOPEID 87 #define NI_WITHSCOPEID 0 88 #endif 89 90 void badlogin(char *); 91 void checknologin(void); 92 void dolastlog(int); 93 void getloginname(void); 94 void motd(char *); 95 int rootterm(char *); 96 void sigint(int); 97 void sleepexit(int); 98 void refused(char *,char *,int); 99 char *stypeof(char *); 100 void timedout(int); 101 int login_access(char *, char *); 102 void login_fbtab(char *, uid_t, gid_t); 103 104 #ifdef USE_PAM 105 static int auth_pam(void); 106 static int export_pam_environment(void); 107 static int ok_to_export(const char *); 108 109 static pam_handle_t *pamh = NULL; 110 static char **environ_pam; 111 112 #define PAM_END { \ 113 if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \ 114 syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e)); \ 115 if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS) \ 116 syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e)); \ 117 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) \ 118 syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); \ 119 } 120 #endif /* USE_PAM */ 121 static int auth_traditional(void); 122 extern void login(struct utmp *); 123 static void usage(void); 124 125 #define TTYGRPNAME "tty" /* name of group to own ttys */ 126 #define DEFAULT_BACKOFF 3 127 #define DEFAULT_RETRIES 10 128 #define DEFAULT_PROMPT "login: " 129 #define DEFAULT_PASSWD_PROMPT "Password:" 130 131 /* 132 * This bounds the time given to login. Not a define so it can 133 * be patched on machines where it's too small. 134 */ 135 u_int timeout = 300; 136 137 /* Buffer for signal handling of timeout */ 138 jmp_buf timeout_buf; 139 140 struct passwd *pwd; 141 int failures; 142 char *term, *envinit[1], *hostname, *passwd_prompt, *prompt, *tty, *username; 143 char full_hostname[MAXHOSTNAMELEN]; 144 145 int 146 main(int argc, char **argv) 147 { 148 extern char **environ; 149 struct group *gr; 150 struct stat st; 151 struct timeval tp; 152 struct utmp utmp; 153 int rootok, retries, backoff; 154 int ask, ch, cnt, fflag, hflag, pflag, quietlog, rootlogin, rval; 155 int changepass; 156 time_t warntime; 157 uid_t uid, euid; 158 gid_t egid; 159 char *p, *ttyn; 160 char tbuf[MAXPATHLEN + 2]; 161 char tname[sizeof(_PATH_TTY) + 10]; 162 char *shell = NULL; 163 login_cap_t *lc = NULL; 164 #ifdef USE_PAM 165 pid_t pid; 166 int e; 167 #endif /* USE_PAM */ 168 169 (void)signal(SIGQUIT, SIG_IGN); 170 (void)signal(SIGINT, SIG_IGN); 171 (void)signal(SIGHUP, SIG_IGN); 172 if (setjmp(timeout_buf)) { 173 if (failures) 174 badlogin(tbuf); 175 (void)fprintf(stderr, "Login timed out after %d seconds\n", 176 timeout); 177 exit(0); 178 } 179 (void)signal(SIGALRM, timedout); 180 (void)alarm(timeout); 181 (void)setpriority(PRIO_PROCESS, 0, 0); 182 183 openlog("login", LOG_ODELAY, LOG_AUTH); 184 185 /* 186 * -p is used by getty to tell login not to destroy the environment 187 * -f is used to skip a second login authentication 188 * -h is used by other servers to pass the name of the remote 189 * host to login so that it may be placed in utmp and wtmp 190 */ 191 *full_hostname = '\0'; 192 term = NULL; 193 194 fflag = hflag = pflag = 0; 195 uid = getuid(); 196 euid = geteuid(); 197 egid = getegid(); 198 while ((ch = getopt(argc, argv, "fh:p")) != -1) 199 switch (ch) { 200 case 'f': 201 fflag = 1; 202 break; 203 case 'h': 204 if (uid) 205 errx(1, "-h option: %s", strerror(EPERM)); 206 hflag = 1; 207 if (strlcpy(full_hostname, optarg, 208 sizeof(full_hostname)) >= sizeof(full_hostname)) 209 errx(1, "-h option: %s: exceeds maximum " 210 "hostname size", optarg); 211 212 trimdomain(optarg, UT_HOSTSIZE); 213 214 if (strlen(optarg) > UT_HOSTSIZE) { 215 struct addrinfo hints, *res; 216 int ga_err; 217 218 memset(&hints, 0, sizeof(hints)); 219 hints.ai_family = AF_UNSPEC; 220 ga_err = getaddrinfo(optarg, NULL, &hints, 221 &res); 222 if (ga_err == 0) { 223 char hostbuf[MAXHOSTNAMELEN]; 224 225 getnameinfo(res->ai_addr, 226 res->ai_addrlen, 227 hostbuf, 228 sizeof(hostbuf), NULL, 0, 229 NI_NUMERICHOST| 230 NI_WITHSCOPEID); 231 optarg = strdup(hostbuf); 232 if (optarg == NULL) { 233 syslog(LOG_NOTICE, 234 "strdup(): %m"); 235 sleepexit(1); 236 } 237 } else 238 optarg = "invalid hostname"; 239 if (res != NULL) 240 freeaddrinfo(res); 241 } 242 hostname = optarg; 243 break; 244 case 'p': 245 pflag = 1; 246 break; 247 case '?': 248 default: 249 if (!uid) 250 syslog(LOG_ERR, "invalid flag %c", ch); 251 usage(); 252 } 253 argc -= optind; 254 argv += optind; 255 256 if (*argv) { 257 username = *argv; 258 ask = 0; 259 } else 260 ask = 1; 261 262 setproctitle("-%s", getprogname()); 263 264 for (cnt = getdtablesize(); cnt > 2; cnt--) 265 (void)close(cnt); 266 267 ttyn = ttyname(STDIN_FILENO); 268 if (ttyn == NULL || *ttyn == '\0') { 269 (void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY); 270 ttyn = tname; 271 } 272 if ((tty = strrchr(ttyn, '/')) != NULL) 273 ++tty; 274 else 275 tty = ttyn; 276 277 /* 278 * Get "login-retries" & "login-backoff" from default class 279 */ 280 lc = login_getclass(NULL); 281 prompt = login_getcapstr(lc, "login_prompt", 282 DEFAULT_PROMPT, DEFAULT_PROMPT); 283 passwd_prompt = login_getcapstr(lc, "passwd_prompt", 284 DEFAULT_PASSWD_PROMPT, DEFAULT_PASSWD_PROMPT); 285 retries = login_getcapnum(lc, "login-retries", DEFAULT_RETRIES, 286 DEFAULT_RETRIES); 287 backoff = login_getcapnum(lc, "login-backoff", DEFAULT_BACKOFF, 288 DEFAULT_BACKOFF); 289 login_close(lc); 290 lc = NULL; 291 292 for (cnt = 0;; ask = 1) { 293 if (ask) { 294 fflag = 0; 295 getloginname(); 296 } 297 rootlogin = 0; 298 rootok = rootterm(tty); /* Default (auth may change) */ 299 300 if (strlen(username) > UT_NAMESIZE) 301 username[UT_NAMESIZE] = '\0'; 302 303 /* 304 * Note if trying multiple user names; log failures for 305 * previous user name, but don't bother logging one failure 306 * for nonexistent name (mistyped username). 307 */ 308 if (failures && strcmp(tbuf, username)) { 309 if (failures > (pwd ? 0 : 1)) 310 badlogin(tbuf); 311 } 312 (void)strlcpy(tbuf, username, sizeof(tbuf)); 313 314 pwd = getpwnam(username); 315 316 /* 317 * if we have a valid account name, and it doesn't have a 318 * password, or the -f option was specified and the caller 319 * is root or the caller isn't changing their uid, don't 320 * authenticate. 321 */ 322 if (pwd != NULL) { 323 if (pwd->pw_uid == 0) 324 rootlogin = 1; 325 326 if (fflag && (uid == (uid_t)0 || 327 uid == (uid_t)pwd->pw_uid)) { 328 /* already authenticated */ 329 break; 330 } else if (pwd->pw_passwd[0] == '\0') { 331 if (!rootlogin || rootok) { 332 /* pretend password okay */ 333 rval = 0; 334 goto ttycheck; 335 } 336 } 337 } 338 339 fflag = 0; 340 341 (void)setpriority(PRIO_PROCESS, 0, -4); 342 343 #ifdef USE_PAM 344 /* 345 * Try to authenticate using PAM. If a PAM system error 346 * occurs, perhaps because of a botched configuration, 347 * then fall back to using traditional Unix authentication. 348 */ 349 if ((rval = auth_pam()) == -1) 350 #endif /* USE_PAM */ 351 rval = auth_traditional(); 352 353 (void)setpriority(PRIO_PROCESS, 0, 0); 354 355 #ifdef USE_PAM 356 /* 357 * PAM authentication may have changed "pwd" to the 358 * entry for the template user. Check again to see if 359 * this is a root login after all. 360 */ 361 if (pwd != NULL && pwd->pw_uid == 0) 362 rootlogin = 1; 363 #endif /* USE_PAM */ 364 365 ttycheck: 366 /* 367 * If trying to log in as root without Kerberos, 368 * but with insecure terminal, refuse the login attempt. 369 */ 370 if (pwd && !rval) { 371 if (rootlogin && !rootok) 372 refused(NULL, "NOROOT", 0); 373 else /* valid password & authenticated */ 374 break; 375 } 376 377 (void)printf("Login incorrect\n"); 378 failures++; 379 380 /* 381 * we allow up to 'retry' (10) tries, 382 * but after 'backoff' (3) we start backing off 383 */ 384 if (++cnt > backoff) { 385 if (cnt >= retries) { 386 badlogin(username); 387 sleepexit(1); 388 } 389 sleep((u_int)((cnt - backoff) * 5)); 390 } 391 } 392 393 /* committed to login -- turn off timeout */ 394 (void)alarm((u_int)0); 395 (void)signal(SIGHUP, SIG_DFL); 396 397 endpwent(); 398 399 /* 400 * Establish the login class. 401 */ 402 lc = login_getpwclass(pwd); 403 404 /* if user not super-user, check for disabled logins */ 405 if (!rootlogin) 406 auth_checknologin(lc); 407 408 quietlog = login_getcapbool(lc, "hushlogin", 0); 409 /* Switching needed for NFS with root access disabled */ 410 (void)setegid(pwd->pw_gid); 411 (void)seteuid(rootlogin ? 0 : pwd->pw_uid); 412 if (!*pwd->pw_dir || chdir(pwd->pw_dir) < 0) { 413 if (login_getcapbool(lc, "requirehome", 0)) 414 refused("Home directory not available", "HOMEDIR", 1); 415 if (chdir("/") < 0) 416 refused("Cannot find root directory", "ROOTDIR", 1); 417 if (!quietlog || *pwd->pw_dir) 418 printf("No home directory.\nLogging in with home = \"/\".\n"); 419 pwd->pw_dir = "/"; 420 } 421 (void)seteuid(euid); 422 (void)setegid(egid); 423 if (!quietlog) 424 quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0; 425 426 if (pwd->pw_change || pwd->pw_expire) 427 (void)gettimeofday(&tp, (struct timezone *)NULL); 428 429 #define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */ 430 431 warntime = login_getcaptime(lc, "warnexpire", DEFAULT_WARN, 432 DEFAULT_WARN); 433 434 if (pwd->pw_expire) { 435 if (tp.tv_sec >= pwd->pw_expire) { 436 refused("Sorry -- your account has expired", "EXPIRED", 437 1); 438 } else if (pwd->pw_expire - tp.tv_sec < warntime && !quietlog) 439 (void)printf("Warning: your account expires on %s", 440 ctime(&pwd->pw_expire)); 441 } 442 443 warntime = login_getcaptime(lc, "warnpassword", DEFAULT_WARN, 444 DEFAULT_WARN); 445 446 changepass = 0; 447 if (pwd->pw_change) { 448 if (tp.tv_sec >= pwd->pw_change) { 449 (void)printf("Sorry -- your password has expired.\n"); 450 changepass = 1; 451 syslog(LOG_INFO, "%s Password expired - forcing change", 452 pwd->pw_name); 453 } else if (pwd->pw_change - tp.tv_sec < warntime && !quietlog) 454 (void)printf("Warning: your password expires on %s", 455 ctime(&pwd->pw_change)); 456 } 457 458 if (lc != NULL) { 459 if (hostname) { 460 struct addrinfo hints, *res; 461 int ga_err; 462 463 memset(&hints, 0, sizeof(hints)); 464 hints.ai_family = AF_UNSPEC; 465 ga_err = getaddrinfo(full_hostname, NULL, &hints, 466 &res); 467 if (ga_err == 0) { 468 char hostbuf[MAXHOSTNAMELEN]; 469 470 getnameinfo(res->ai_addr, res->ai_addrlen, 471 hostbuf, sizeof(hostbuf), NULL, 0, 472 NI_NUMERICHOST|NI_WITHSCOPEID); 473 if ((optarg = strdup(hostbuf)) == NULL) { 474 syslog(LOG_NOTICE, "strdup(): %m"); 475 sleepexit(1); 476 } 477 } else 478 optarg = NULL; 479 if (res != NULL) 480 freeaddrinfo(res); 481 if (!auth_hostok(lc, full_hostname, optarg)) 482 refused("Permission denied", "HOST", 1); 483 } 484 485 if (!auth_ttyok(lc, tty)) 486 refused("Permission denied", "TTY", 1); 487 488 if (!auth_timeok(lc, time(NULL))) 489 refused("Logins not available right now", "TIME", 1); 490 } 491 shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell); 492 if (*pwd->pw_shell == '\0') 493 pwd->pw_shell = _PATH_BSHELL; 494 if (*shell == '\0') /* Not overridden */ 495 shell = pwd->pw_shell; 496 if ((shell = strdup(shell)) == NULL) { 497 syslog(LOG_NOTICE, "strdup(): %m"); 498 sleepexit(1); 499 } 500 501 #ifdef LOGIN_ACCESS 502 if (login_access(pwd->pw_name, hostname ? full_hostname : tty) == 0) 503 refused("Permission denied", "ACCESS", 1); 504 #endif /* LOGIN_ACCESS */ 505 506 /* Nothing else left to fail -- really log in. */ 507 memset((void *)&utmp, 0, sizeof(utmp)); 508 (void)time(&utmp.ut_time); 509 (void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name)); 510 if (hostname) 511 (void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host)); 512 (void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line)); 513 login(&utmp); 514 515 dolastlog(quietlog); 516 517 /* 518 * Set device protections, depending on what terminal the 519 * user is logged in. This feature is used on Suns to give 520 * console users better privacy. 521 */ 522 login_fbtab(tty, pwd->pw_uid, pwd->pw_gid); 523 524 /* 525 * Clear flags of the tty. None should be set, and when the 526 * user sets them otherwise, this can cause the chown to fail. 527 * Since it isn't clear that flags are useful on character 528 * devices, we just clear them. 529 */ 530 if (ttyn != tname && chflags(ttyn, 0) && errno != EOPNOTSUPP) 531 syslog(LOG_ERR, "chflags(%s): %m", ttyn); 532 if (ttyn != tname && chown(ttyn, pwd->pw_uid, 533 (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid)) 534 syslog(LOG_ERR, "chmod(%s): %m", ttyn); 535 536 537 /* 538 * Preserve TERM if it happens to be already set. 539 */ 540 if ((term = getenv("TERM")) != NULL) { 541 if ((term = strdup(term)) == NULL) { 542 syslog(LOG_NOTICE, 543 "strdup(): %m"); 544 sleepexit(1); 545 } 546 } 547 548 /* 549 * Exclude cons/vt/ptys only, assume dialup otherwise 550 * TODO: Make dialup tty determination a library call 551 * for consistency (finger etc.) 552 */ 553 if (hostname==NULL && isdialuptty(tty)) 554 syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name); 555 556 #ifdef LOGALL 557 /* 558 * Syslog each successful login, so we don't have to watch hundreds 559 * of wtmp or lastlogin files. 560 */ 561 if (hostname) 562 syslog(LOG_INFO, "login from %s on %s as %s", 563 full_hostname, tty, pwd->pw_name); 564 else 565 syslog(LOG_INFO, "login on %s as %s", 566 tty, pwd->pw_name); 567 #endif 568 569 /* 570 * If fflag is on, assume caller/authenticator has logged root login. 571 */ 572 if (rootlogin && fflag == 0) 573 { 574 if (hostname) 575 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s", 576 username, tty, full_hostname); 577 else 578 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s", 579 username, tty); 580 } 581 582 /* 583 * Destroy environment unless user has requested its preservation. 584 * We need to do this before setusercontext() because that may 585 * set or reset some environment variables. 586 */ 587 if (!pflag) 588 environ = envinit; 589 590 /* 591 * PAM modules might add supplementary groups during pam_setcred(). 592 */ 593 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) { 594 syslog(LOG_ERR, "setusercontext() failed - exiting"); 595 exit(1); 596 } 597 598 #ifdef USE_PAM 599 if (pamh) { 600 if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) { 601 syslog(LOG_ERR, "pam_open_session: %s", 602 pam_strerror(pamh, e)); 603 } else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) 604 != PAM_SUCCESS) { 605 syslog(LOG_ERR, "pam_setcred: %s", 606 pam_strerror(pamh, e)); 607 } 608 609 /* 610 * Add any environmental variables that the 611 * PAM modules may have set. 612 * Call *after* opening session! 613 */ 614 if (pamh) { 615 environ_pam = pam_getenvlist(pamh); 616 if (environ_pam) 617 export_pam_environment(); 618 } 619 620 /* 621 * We must fork() before setuid() because we need to call 622 * pam_close_session() as root. 623 */ 624 pid = fork(); 625 if (pid < 0) { 626 err(1, "fork"); 627 PAM_END; 628 exit(0); 629 } else if (pid) { 630 /* parent - wait for child to finish, then cleanup 631 session */ 632 setproctitle("-%s [pam]", getprogname()); 633 wait(NULL); 634 PAM_END; 635 exit(0); 636 } else { 637 if ((e = pam_end(pamh, PAM_DATA_SILENT)) != PAM_SUCCESS) 638 syslog(LOG_ERR, "pam_end: %s", 639 pam_strerror(pamh, e)); 640 } 641 } 642 #endif /* USE_PAM */ 643 644 /* 645 * We don't need to be root anymore, so 646 * set the user and session context 647 */ 648 if (setlogin(username) != 0) { 649 syslog(LOG_ERR, "setlogin(%s): %m - exiting", username); 650 exit(1); 651 } 652 if (setusercontext(lc, pwd, pwd->pw_uid, 653 LOGIN_SETALL & ~(LOGIN_SETLOGIN|LOGIN_SETGROUP)) != 0) { 654 syslog(LOG_ERR, "setusercontext() failed - exiting"); 655 exit(1); 656 } 657 658 (void)setenv("SHELL", pwd->pw_shell, 1); 659 (void)setenv("HOME", pwd->pw_dir, 1); 660 if (term != NULL && *term != '\0') 661 (void)setenv("TERM", term, 1); /* Preset overrides */ 662 else { 663 (void)setenv("TERM", stypeof(tty), 0); /* Fallback doesn't */ 664 } 665 (void)setenv("LOGNAME", username, 1); 666 (void)setenv("USER", username, 1); 667 (void)setenv("PATH", rootlogin ? _PATH_STDPATH : _PATH_DEFPATH, 0); 668 669 if (!quietlog) { 670 char *cw; 671 672 cw = login_getcapstr(lc, "copyright", NULL, NULL); 673 if (cw != NULL && access(cw, F_OK) == 0) 674 motd(cw); 675 else 676 (void)printf("%s\n\t%s %s\n", 677 "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994", 678 "The Regents of the University of California. ", 679 "All rights reserved."); 680 681 (void)printf("\n"); 682 683 cw = login_getcapstr(lc, "welcome", NULL, NULL); 684 if (cw == NULL || access(cw, F_OK) != 0) 685 cw = _PATH_MOTDFILE; 686 motd(cw); 687 688 cw = getenv("MAIL"); /* $MAIL may have been set by class */ 689 if (cw != NULL) 690 strlcpy(tbuf, cw, sizeof(tbuf)); 691 else 692 snprintf(tbuf, sizeof(tbuf), "%s/%s", _PATH_MAILDIR, 693 pwd->pw_name); 694 if (stat(tbuf, &st) == 0 && st.st_size != 0) 695 (void)printf("You have %smail.\n", 696 (st.st_mtime > st.st_atime) ? "new " : ""); 697 } 698 699 login_close(lc); 700 701 (void)signal(SIGALRM, SIG_DFL); 702 (void)signal(SIGQUIT, SIG_DFL); 703 (void)signal(SIGINT, SIG_DFL); 704 (void)signal(SIGTSTP, SIG_IGN); 705 706 if (changepass) { 707 if (system(_PATH_CHPASS) != 0) 708 sleepexit(1); 709 } 710 711 /* 712 * Login shells have a leading '-' in front of argv[0] 713 */ 714 if (snprintf(tbuf, sizeof(tbuf), "-%s", 715 (p = strrchr(pwd->pw_shell, '/')) ? p + 1 : pwd->pw_shell) >= 716 sizeof(tbuf)) { 717 syslog(LOG_ERR, "user: %s: shell exceeds maximum pathname size", 718 username); 719 errx(1, "shell exceeds maximum pathname size"); 720 } 721 722 execlp(shell, tbuf, (char *)0); 723 err(1, "%s", shell); 724 } 725 726 static int 727 auth_traditional(void) 728 { 729 int rval; 730 char *p; 731 char *ep; 732 char *salt; 733 734 rval = 1; 735 salt = pwd != NULL ? pwd->pw_passwd : "xx"; 736 737 p = getpass(passwd_prompt); 738 ep = crypt(p, salt); 739 740 if (pwd) { 741 if (!p[0] && pwd->pw_passwd[0]) 742 ep = ":"; 743 if (strcmp(ep, pwd->pw_passwd) == 0) 744 rval = 0; 745 } 746 747 /* clear entered password */ 748 memset(p, 0, strlen(p)); 749 return rval; 750 } 751 752 #ifdef USE_PAM 753 /* 754 * Attempt to authenticate the user using PAM. Returns 0 if the user is 755 * authenticated, or 1 if not authenticated. If some sort of PAM system 756 * error occurs (e.g., the "/etc/pam.conf" file is missing) then this 757 * function returns -1. This can be used as an indication that we should 758 * fall back to a different authentication mechanism. 759 */ 760 static int 761 auth_pam(void) 762 { 763 const char *tmpl_user; 764 const void *item; 765 int rval; 766 int e; 767 static struct pam_conv conv = { misc_conv, NULL }; 768 769 if ((e = pam_start("login", username, &conv, &pamh)) != PAM_SUCCESS) { 770 syslog(LOG_ERR, "pam_start: %s", pam_strerror(pamh, e)); 771 return -1; 772 } 773 if ((e = pam_set_item(pamh, PAM_TTY, tty)) != PAM_SUCCESS) { 774 syslog(LOG_ERR, "pam_set_item(PAM_TTY): %s", 775 pam_strerror(pamh, e)); 776 return -1; 777 } 778 if (hostname != NULL && 779 (e = pam_set_item(pamh, PAM_RHOST, full_hostname)) != PAM_SUCCESS) { 780 syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s", 781 pam_strerror(pamh, e)); 782 return -1; 783 } 784 e = pam_authenticate(pamh, 0); 785 switch (e) { 786 787 case PAM_SUCCESS: 788 /* 789 * With PAM we support the concept of a "template" 790 * user. The user enters a login name which is 791 * authenticated by PAM, usually via a remote service 792 * such as RADIUS or TACACS+. If authentication 793 * succeeds, a different but related "template" name 794 * is used for setting the credentials, shell, and 795 * home directory. The name the user enters need only 796 * exist on the remote authentication server, but the 797 * template name must be present in the local password 798 * database. 799 * 800 * This is supported by two various mechanisms in the 801 * individual modules. However, from the application's 802 * point of view, the template user is always passed 803 * back as a changed value of the PAM_USER item. 804 */ 805 if ((e = pam_get_item(pamh, PAM_USER, &item)) == 806 PAM_SUCCESS) { 807 tmpl_user = (const char *) item; 808 if (strcmp(username, tmpl_user) != 0) 809 pwd = getpwnam(tmpl_user); 810 } else 811 syslog(LOG_ERR, "Couldn't get PAM_USER: %s", 812 pam_strerror(pamh, e)); 813 rval = 0; 814 break; 815 816 case PAM_AUTH_ERR: 817 case PAM_USER_UNKNOWN: 818 case PAM_MAXTRIES: 819 rval = 1; 820 break; 821 822 default: 823 syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e)); 824 rval = -1; 825 break; 826 } 827 828 if (rval == 0) { 829 e = pam_acct_mgmt(pamh, 0); 830 if (e == PAM_NEW_AUTHTOK_REQD) { 831 e = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK); 832 if (e != PAM_SUCCESS) { 833 syslog(LOG_ERR, "pam_chauthtok: %s", 834 pam_strerror(pamh, e)); 835 rval = 1; 836 } 837 } else if (e != PAM_SUCCESS) { 838 rval = 1; 839 } 840 } 841 842 if (rval != 0) { 843 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) { 844 syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); 845 } 846 pamh = NULL; 847 } 848 return rval; 849 } 850 851 static int 852 export_pam_environment(void) 853 { 854 char **pp; 855 856 for (pp = environ_pam; *pp != NULL; pp++) { 857 if (ok_to_export(*pp)) 858 (void) putenv(*pp); 859 free(*pp); 860 } 861 return PAM_SUCCESS; 862 } 863 864 /* 865 * Sanity checks on PAM environmental variables: 866 * - Make sure there is an '=' in the string. 867 * - Make sure the string doesn't run on too long. 868 * - Do not export certain variables. This list was taken from the 869 * Solaris pam_putenv(3) man page. 870 */ 871 static int 872 ok_to_export(const char *s) 873 { 874 static const char *noexport[] = { 875 "SHELL", "HOME", "LOGNAME", "MAIL", "CDPATH", 876 "IFS", "PATH", NULL 877 }; 878 const char **pp; 879 size_t n; 880 881 if (strlen(s) > 1024 || strchr(s, '=') == NULL) 882 return 0; 883 if (strncmp(s, "LD_", 3) == 0) 884 return 0; 885 for (pp = noexport; *pp != NULL; pp++) { 886 n = strlen(*pp); 887 if (s[n] == '=' && strncmp(s, *pp, n) == 0) 888 return 0; 889 } 890 return 1; 891 } 892 #endif /* USE_PAM */ 893 894 static void 895 usage(void) 896 { 897 898 (void)fprintf(stderr, "usage: login [-fp] [-h hostname] [username]\n"); 899 exit(1); 900 } 901 902 /* 903 * Allow for authentication style and/or kerberos instance 904 */ 905 906 #define NBUFSIZ UT_NAMESIZE + 64 907 908 void 909 getloginname(void) 910 { 911 int ch; 912 char *p; 913 static char nbuf[NBUFSIZ]; 914 915 for (;;) { 916 (void)printf("%s", prompt); 917 for (p = nbuf; (ch = getchar()) != '\n'; ) { 918 if (ch == EOF) { 919 badlogin(username); 920 exit(0); 921 } 922 if (p < nbuf + (NBUFSIZ - 1)) 923 *p++ = ch; 924 } 925 if (p > nbuf) { 926 if (nbuf[0] == '-') 927 (void)fprintf(stderr, 928 "login names may not start with '-'.\n"); 929 else { 930 *p = '\0'; 931 username = nbuf; 932 break; 933 } 934 } 935 } 936 } 937 938 int 939 rootterm(char *ttyn) 940 { 941 struct ttyent *t; 942 943 return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE); 944 } 945 946 volatile int motdinterrupt; 947 948 void 949 sigint(int signo __unused) 950 { 951 motdinterrupt = 1; 952 } 953 954 void 955 motd(char *motdfile) 956 { 957 int fd, nchars; 958 sig_t oldint; 959 char tbuf[256]; 960 961 if ((fd = open(motdfile, O_RDONLY, 0)) < 0) 962 return; 963 motdinterrupt = 0; 964 oldint = signal(SIGINT, sigint); 965 while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0 && !motdinterrupt) 966 (void)write(fileno(stdout), tbuf, nchars); 967 (void)signal(SIGINT, oldint); 968 (void)close(fd); 969 } 970 971 /* ARGSUSED */ 972 void 973 timedout(int signo) 974 { 975 976 longjmp(timeout_buf, signo); 977 } 978 979 980 void 981 dolastlog(int quiet) 982 { 983 struct lastlog ll; 984 int fd; 985 986 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) { 987 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 988 if (!quiet) { 989 if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) && 990 ll.ll_time != 0) { 991 (void)printf("Last login: %.*s ", 992 24-5, (char *)ctime(&ll.ll_time)); 993 if (*ll.ll_host != '\0') 994 (void)printf("from %.*s\n", 995 (int)sizeof(ll.ll_host), 996 ll.ll_host); 997 else 998 (void)printf("on %.*s\n", 999 (int)sizeof(ll.ll_line), 1000 ll.ll_line); 1001 } 1002 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 1003 } 1004 memset((void *)&ll, 0, sizeof(ll)); 1005 (void)time(&ll.ll_time); 1006 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line)); 1007 if (hostname) 1008 (void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host)); 1009 (void)write(fd, (char *)&ll, sizeof(ll)); 1010 (void)close(fd); 1011 } else { 1012 syslog(LOG_ERR, "cannot open %s: %m", _PATH_LASTLOG); 1013 } 1014 } 1015 1016 void 1017 badlogin(char *name) 1018 { 1019 1020 if (failures == 0) 1021 return; 1022 if (hostname) { 1023 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s", 1024 failures, failures > 1 ? "S" : "", full_hostname); 1025 syslog(LOG_AUTHPRIV|LOG_NOTICE, 1026 "%d LOGIN FAILURE%s FROM %s, %s", 1027 failures, failures > 1 ? "S" : "", full_hostname, name); 1028 } else { 1029 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s", 1030 failures, failures > 1 ? "S" : "", tty); 1031 syslog(LOG_AUTHPRIV|LOG_NOTICE, 1032 "%d LOGIN FAILURE%s ON %s, %s", 1033 failures, failures > 1 ? "S" : "", tty, name); 1034 } 1035 failures = 0; 1036 } 1037 1038 #undef UNKNOWN 1039 #define UNKNOWN "su" 1040 1041 char * 1042 stypeof(char *ttyid) 1043 { 1044 struct ttyent *t; 1045 1046 if (ttyid != NULL && *ttyid != '\0') { 1047 t = getttynam(ttyid); 1048 if (t != NULL && t->ty_type != NULL) 1049 return (t->ty_type); 1050 } 1051 return (UNKNOWN); 1052 } 1053 1054 void 1055 refused(char *msg, char *rtype, int lout) 1056 { 1057 1058 if (msg != NULL) 1059 printf("%s.\n", msg); 1060 if (hostname) 1061 syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) FROM %s ON TTY %s", 1062 pwd->pw_name, rtype, full_hostname, tty); 1063 else 1064 syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) ON TTY %s", 1065 pwd->pw_name, rtype, tty); 1066 if (lout) 1067 sleepexit(1); 1068 } 1069 1070 void 1071 sleepexit(int eval) 1072 { 1073 1074 (void)sleep(5); 1075 exit(eval); 1076 } 1077