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 1.6 2006/01/12 13:43:11 corecode 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_types.h> 80 #include <security/openpam.h> 81 #include <sys/wait.h> 82 #endif /* USE_PAM */ 83 84 #include "pathnames.h" 85 86 /* wrapper for KAME-special getnameinfo() */ 87 #ifndef NI_WITHSCOPEID 88 #define NI_WITHSCOPEID 0 89 #endif 90 91 void badlogin(char *); 92 void checknologin(void); 93 void dolastlog(int); 94 void getloginname(void); 95 void motd(char *); 96 int rootterm(char *); 97 void sigint(int); 98 void sleepexit(int); 99 void refused(char *,char *,int); 100 char *stypeof(char *); 101 void timedout(int); 102 int login_access(char *, char *); 103 void login_fbtab(char *, uid_t, gid_t); 104 105 #ifdef USE_PAM 106 static int auth_pam(void); 107 static int export_pam_environment(void); 108 static int ok_to_export(const char *); 109 110 static pam_handle_t *pamh = NULL; 111 static char **environ_pam; 112 113 #define PAM_END { \ 114 if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \ 115 syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e)); \ 116 if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS) \ 117 syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e)); \ 118 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) \ 119 syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); \ 120 } 121 #endif /* USE_PAM */ 122 static int auth_traditional(void); 123 extern void login(struct utmp *); 124 static void usage(void); 125 126 #define TTYGRPNAME "tty" /* name of group to own ttys */ 127 #define DEFAULT_BACKOFF 3 128 #define DEFAULT_RETRIES 10 129 #define DEFAULT_PROMPT "login: " 130 #define DEFAULT_PASSWD_PROMPT "Password:" 131 132 /* 133 * This bounds the time given to login. Not a define so it can 134 * be patched on machines where it's too small. 135 */ 136 u_int timeout = 300; 137 138 /* Buffer for signal handling of timeout */ 139 jmp_buf timeout_buf; 140 141 struct passwd *pwd; 142 int failures; 143 char *term, *envinit[1], *hostname, *passwd_prompt, *prompt, *tty, *username; 144 char full_hostname[MAXHOSTNAMELEN]; 145 146 int 147 main(int argc, char **argv) 148 { 149 extern char **environ; 150 struct group *gr; 151 struct stat st; 152 struct timeval tp; 153 struct utmp utmp; 154 int rootok, retries, backoff; 155 int ask, ch, cnt, fflag, hflag, pflag, quietlog, rootlogin, rval; 156 int changepass; 157 time_t warntime; 158 uid_t uid, euid; 159 gid_t egid; 160 char *p, *ttyn; 161 char tbuf[MAXPATHLEN + 2]; 162 char tname[sizeof(_PATH_TTY) + 10]; 163 char *shell = NULL; 164 login_cap_t *lc = NULL; 165 #ifdef USE_PAM 166 pid_t pid; 167 int e; 168 #endif /* USE_PAM */ 169 170 (void)signal(SIGQUIT, SIG_IGN); 171 (void)signal(SIGINT, SIG_IGN); 172 (void)signal(SIGHUP, SIG_IGN); 173 if (setjmp(timeout_buf)) { 174 if (failures) 175 badlogin(tbuf); 176 (void)fprintf(stderr, "Login timed out after %d seconds\n", 177 timeout); 178 exit(0); 179 } 180 (void)signal(SIGALRM, timedout); 181 (void)alarm(timeout); 182 (void)setpriority(PRIO_PROCESS, 0, 0); 183 184 openlog("login", LOG_ODELAY, LOG_AUTH); 185 186 /* 187 * -p is used by getty to tell login not to destroy the environment 188 * -f is used to skip a second login authentication 189 * -h is used by other servers to pass the name of the remote 190 * host to login so that it may be placed in utmp and wtmp 191 */ 192 *full_hostname = '\0'; 193 term = NULL; 194 195 fflag = hflag = pflag = 0; 196 uid = getuid(); 197 euid = geteuid(); 198 egid = getegid(); 199 while ((ch = getopt(argc, argv, "fh:p")) != -1) 200 switch (ch) { 201 case 'f': 202 fflag = 1; 203 break; 204 case 'h': 205 if (uid) 206 errx(1, "-h option: %s", strerror(EPERM)); 207 hflag = 1; 208 if (strlcpy(full_hostname, optarg, 209 sizeof(full_hostname)) >= sizeof(full_hostname)) 210 errx(1, "-h option: %s: exceeds maximum " 211 "hostname size", optarg); 212 213 trimdomain(optarg, UT_HOSTSIZE); 214 215 if (strlen(optarg) > UT_HOSTSIZE) { 216 struct addrinfo hints, *res; 217 int ga_err; 218 219 memset(&hints, 0, sizeof(hints)); 220 hints.ai_family = AF_UNSPEC; 221 ga_err = getaddrinfo(optarg, NULL, &hints, 222 &res); 223 if (ga_err == 0) { 224 char hostbuf[MAXHOSTNAMELEN]; 225 226 getnameinfo(res->ai_addr, 227 res->ai_addrlen, 228 hostbuf, 229 sizeof(hostbuf), NULL, 0, 230 NI_NUMERICHOST| 231 NI_WITHSCOPEID); 232 optarg = strdup(hostbuf); 233 if (optarg == NULL) { 234 syslog(LOG_NOTICE, 235 "strdup(): %m"); 236 sleepexit(1); 237 } 238 } else 239 optarg = "invalid hostname"; 240 if (res != NULL) 241 freeaddrinfo(res); 242 } 243 hostname = optarg; 244 break; 245 case 'p': 246 pflag = 1; 247 break; 248 case '?': 249 default: 250 if (!uid) 251 syslog(LOG_ERR, "invalid flag %c", ch); 252 usage(); 253 } 254 argc -= optind; 255 argv += optind; 256 257 if (*argv) { 258 username = *argv; 259 ask = 0; 260 } else 261 ask = 1; 262 263 setproctitle("-%s", getprogname()); 264 265 for (cnt = getdtablesize(); cnt > 2; cnt--) 266 (void)close(cnt); 267 268 ttyn = ttyname(STDIN_FILENO); 269 if (ttyn == NULL || *ttyn == '\0') { 270 (void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY); 271 ttyn = tname; 272 } 273 if ((tty = strrchr(ttyn, '/')) != NULL) 274 ++tty; 275 else 276 tty = ttyn; 277 278 /* 279 * Get "login-retries" & "login-backoff" from default class 280 */ 281 lc = login_getclass(NULL); 282 prompt = login_getcapstr(lc, "login_prompt", 283 DEFAULT_PROMPT, DEFAULT_PROMPT); 284 passwd_prompt = login_getcapstr(lc, "passwd_prompt", 285 DEFAULT_PASSWD_PROMPT, DEFAULT_PASSWD_PROMPT); 286 retries = login_getcapnum(lc, "login-retries", DEFAULT_RETRIES, 287 DEFAULT_RETRIES); 288 backoff = login_getcapnum(lc, "login-backoff", DEFAULT_BACKOFF, 289 DEFAULT_BACKOFF); 290 login_close(lc); 291 lc = NULL; 292 293 for (cnt = 0;; ask = 1) { 294 if (ask) { 295 fflag = 0; 296 getloginname(); 297 } 298 rootlogin = 0; 299 rootok = rootterm(tty); /* Default (auth may change) */ 300 301 if (strlen(username) > UT_NAMESIZE) 302 username[UT_NAMESIZE] = '\0'; 303 304 /* 305 * Note if trying multiple user names; log failures for 306 * previous user name, but don't bother logging one failure 307 * for nonexistent name (mistyped username). 308 */ 309 if (failures && strcmp(tbuf, username)) { 310 if (failures > (pwd ? 0 : 1)) 311 badlogin(tbuf); 312 } 313 (void)strlcpy(tbuf, username, sizeof(tbuf)); 314 315 pwd = getpwnam(username); 316 317 /* 318 * if we have a valid account name, and it doesn't have a 319 * password, or the -f option was specified and the caller 320 * is root or the caller isn't changing their uid, don't 321 * authenticate. 322 */ 323 if (pwd != NULL) { 324 if (pwd->pw_uid == 0) 325 rootlogin = 1; 326 327 if (fflag && (uid == (uid_t)0 || 328 uid == (uid_t)pwd->pw_uid)) { 329 /* already authenticated */ 330 break; 331 } else if (pwd->pw_passwd[0] == '\0') { 332 if (!rootlogin || rootok) { 333 /* pretend password okay */ 334 rval = 0; 335 goto ttycheck; 336 } 337 } 338 } 339 340 fflag = 0; 341 342 (void)setpriority(PRIO_PROCESS, 0, -4); 343 344 #ifdef USE_PAM 345 /* 346 * Try to authenticate using PAM. If a PAM system error 347 * occurs, perhaps because of a botched configuration, 348 * then fall back to using traditional Unix authentication. 349 */ 350 if ((rval = auth_pam()) == -1) 351 #endif /* USE_PAM */ 352 rval = auth_traditional(); 353 354 (void)setpriority(PRIO_PROCESS, 0, 0); 355 356 #ifdef USE_PAM 357 /* 358 * PAM authentication may have changed "pwd" to the 359 * entry for the template user. Check again to see if 360 * this is a root login after all. 361 */ 362 if (pwd != NULL && pwd->pw_uid == 0) 363 rootlogin = 1; 364 #endif /* USE_PAM */ 365 366 ttycheck: 367 /* 368 * If trying to log in as root without Kerberos, 369 * but with insecure terminal, refuse the login attempt. 370 */ 371 if (pwd && !rval) { 372 if (rootlogin && !rootok) 373 refused(NULL, "NOROOT", 0); 374 else /* valid password & authenticated */ 375 break; 376 } 377 378 (void)printf("Login incorrect\n"); 379 failures++; 380 381 /* 382 * we allow up to 'retry' (10) tries, 383 * but after 'backoff' (3) we start backing off 384 */ 385 if (++cnt > backoff) { 386 if (cnt >= retries) { 387 badlogin(username); 388 sleepexit(1); 389 } 390 sleep((u_int)((cnt - backoff) * 5)); 391 } 392 } 393 394 /* committed to login -- turn off timeout */ 395 (void)alarm((u_int)0); 396 (void)signal(SIGHUP, SIG_DFL); 397 398 endpwent(); 399 400 /* 401 * Establish the login class. 402 */ 403 lc = login_getpwclass(pwd); 404 405 /* if user not super-user, check for disabled logins */ 406 if (!rootlogin) 407 auth_checknologin(lc); 408 409 quietlog = login_getcapbool(lc, "hushlogin", 0); 410 /* Switching needed for NFS with root access disabled */ 411 (void)setegid(pwd->pw_gid); 412 (void)seteuid(rootlogin ? 0 : pwd->pw_uid); 413 if (!*pwd->pw_dir || chdir(pwd->pw_dir) < 0) { 414 if (login_getcapbool(lc, "requirehome", 0)) 415 refused("Home directory not available", "HOMEDIR", 1); 416 if (chdir("/") < 0) 417 refused("Cannot find root directory", "ROOTDIR", 1); 418 if (!quietlog || *pwd->pw_dir) 419 printf("No home directory.\nLogging in with home = \"/\".\n"); 420 pwd->pw_dir = "/"; 421 } 422 (void)seteuid(euid); 423 (void)setegid(egid); 424 if (!quietlog) 425 quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0; 426 427 if (pwd->pw_change || pwd->pw_expire) 428 (void)gettimeofday(&tp, (struct timezone *)NULL); 429 430 #define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */ 431 432 warntime = login_getcaptime(lc, "warnexpire", DEFAULT_WARN, 433 DEFAULT_WARN); 434 435 if (pwd->pw_expire) { 436 if (tp.tv_sec >= pwd->pw_expire) { 437 refused("Sorry -- your account has expired", "EXPIRED", 438 1); 439 } else if (pwd->pw_expire - tp.tv_sec < warntime && !quietlog) 440 (void)printf("Warning: your account expires on %s", 441 ctime(&pwd->pw_expire)); 442 } 443 444 warntime = login_getcaptime(lc, "warnpassword", DEFAULT_WARN, 445 DEFAULT_WARN); 446 447 changepass = 0; 448 if (pwd->pw_change) { 449 if (tp.tv_sec >= pwd->pw_change) { 450 (void)printf("Sorry -- your password has expired.\n"); 451 changepass = 1; 452 syslog(LOG_INFO, "%s Password expired - forcing change", 453 pwd->pw_name); 454 } else if (pwd->pw_change - tp.tv_sec < warntime && !quietlog) 455 (void)printf("Warning: your password expires on %s", 456 ctime(&pwd->pw_change)); 457 } 458 459 if (lc != NULL) { 460 if (hostname) { 461 struct addrinfo hints, *res; 462 int ga_err; 463 464 memset(&hints, 0, sizeof(hints)); 465 hints.ai_family = AF_UNSPEC; 466 ga_err = getaddrinfo(full_hostname, NULL, &hints, 467 &res); 468 if (ga_err == 0) { 469 char hostbuf[MAXHOSTNAMELEN]; 470 471 getnameinfo(res->ai_addr, res->ai_addrlen, 472 hostbuf, sizeof(hostbuf), NULL, 0, 473 NI_NUMERICHOST|NI_WITHSCOPEID); 474 if ((optarg = strdup(hostbuf)) == NULL) { 475 syslog(LOG_NOTICE, "strdup(): %m"); 476 sleepexit(1); 477 } 478 } else 479 optarg = NULL; 480 if (res != NULL) 481 freeaddrinfo(res); 482 if (!auth_hostok(lc, full_hostname, optarg)) 483 refused("Permission denied", "HOST", 1); 484 } 485 486 if (!auth_ttyok(lc, tty)) 487 refused("Permission denied", "TTY", 1); 488 489 if (!auth_timeok(lc, time(NULL))) 490 refused("Logins not available right now", "TIME", 1); 491 } 492 shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell); 493 if (*pwd->pw_shell == '\0') 494 pwd->pw_shell = _PATH_BSHELL; 495 if (*shell == '\0') /* Not overridden */ 496 shell = pwd->pw_shell; 497 if ((shell = strdup(shell)) == NULL) { 498 syslog(LOG_NOTICE, "strdup(): %m"); 499 sleepexit(1); 500 } 501 502 #ifdef LOGIN_ACCESS 503 if (login_access(pwd->pw_name, hostname ? full_hostname : tty) == 0) 504 refused("Permission denied", "ACCESS", 1); 505 #endif /* LOGIN_ACCESS */ 506 507 /* Nothing else left to fail -- really log in. */ 508 memset((void *)&utmp, 0, sizeof(utmp)); 509 (void)time(&utmp.ut_time); 510 (void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name)); 511 if (hostname) 512 (void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host)); 513 (void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line)); 514 login(&utmp); 515 516 dolastlog(quietlog); 517 518 /* 519 * Set device protections, depending on what terminal the 520 * user is logged in. This feature is used on Suns to give 521 * console users better privacy. 522 */ 523 login_fbtab(tty, pwd->pw_uid, pwd->pw_gid); 524 525 /* 526 * Clear flags of the tty. None should be set, and when the 527 * user sets them otherwise, this can cause the chown to fail. 528 * Since it isn't clear that flags are useful on character 529 * devices, we just clear them. 530 */ 531 if (ttyn != tname && chflags(ttyn, 0) && errno != EOPNOTSUPP) 532 syslog(LOG_ERR, "chflags(%s): %m", ttyn); 533 if (ttyn != tname && chown(ttyn, pwd->pw_uid, 534 (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid)) 535 syslog(LOG_ERR, "chmod(%s): %m", ttyn); 536 537 538 /* 539 * Preserve TERM if it happens to be already set. 540 */ 541 if ((term = getenv("TERM")) != NULL) { 542 if ((term = strdup(term)) == NULL) { 543 syslog(LOG_NOTICE, 544 "strdup(): %m"); 545 sleepexit(1); 546 } 547 } 548 549 /* 550 * Exclude cons/vt/ptys only, assume dialup otherwise 551 * TODO: Make dialup tty determination a library call 552 * for consistency (finger etc.) 553 */ 554 if (hostname==NULL && isdialuptty(tty)) 555 syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name); 556 557 #ifdef LOGALL 558 /* 559 * Syslog each successful login, so we don't have to watch hundreds 560 * of wtmp or lastlogin files. 561 */ 562 if (hostname) 563 syslog(LOG_INFO, "login from %s on %s as %s", 564 full_hostname, tty, pwd->pw_name); 565 else 566 syslog(LOG_INFO, "login on %s as %s", 567 tty, pwd->pw_name); 568 #endif 569 570 /* 571 * If fflag is on, assume caller/authenticator has logged root login. 572 */ 573 if (rootlogin && fflag == 0) 574 { 575 if (hostname) 576 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s", 577 username, tty, full_hostname); 578 else 579 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s", 580 username, tty); 581 } 582 583 /* 584 * Destroy environment unless user has requested its preservation. 585 * We need to do this before setusercontext() because that may 586 * set or reset some environment variables. 587 */ 588 if (!pflag) 589 environ = envinit; 590 591 /* 592 * PAM modules might add supplementary groups during pam_setcred(). 593 */ 594 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) { 595 syslog(LOG_ERR, "setusercontext() failed - exiting"); 596 exit(1); 597 } 598 599 #ifdef USE_PAM 600 if (pamh) { 601 if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) { 602 syslog(LOG_ERR, "pam_open_session: %s", 603 pam_strerror(pamh, e)); 604 } else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) 605 != PAM_SUCCESS) { 606 syslog(LOG_ERR, "pam_setcred: %s", 607 pam_strerror(pamh, e)); 608 } 609 610 /* 611 * Add any environmental variables that the 612 * PAM modules may have set. 613 * Call *after* opening session! 614 */ 615 if (pamh) { 616 environ_pam = pam_getenvlist(pamh); 617 if (environ_pam) 618 export_pam_environment(); 619 } 620 621 /* 622 * We must fork() before setuid() because we need to call 623 * pam_close_session() as root. 624 */ 625 pid = fork(); 626 if (pid < 0) { 627 err(1, "fork"); 628 PAM_END; 629 exit(0); 630 } else if (pid) { 631 /* parent - wait for child to finish, then cleanup 632 session */ 633 setproctitle("-%s [pam]", getprogname()); 634 wait(NULL); 635 PAM_END; 636 exit(0); 637 } else { 638 if ((e = pam_end(pamh, PAM_SILENT)) != PAM_SUCCESS) 639 syslog(LOG_ERR, "pam_end: %s", 640 pam_strerror(pamh, e)); 641 } 642 } 643 #endif /* USE_PAM */ 644 645 /* 646 * We don't need to be root anymore, so 647 * set the user and session context 648 */ 649 if (setlogin(username) != 0) { 650 syslog(LOG_ERR, "setlogin(%s): %m - exiting", username); 651 exit(1); 652 } 653 if (setusercontext(lc, pwd, pwd->pw_uid, 654 LOGIN_SETALL & ~(LOGIN_SETLOGIN|LOGIN_SETGROUP)) != 0) { 655 syslog(LOG_ERR, "setusercontext() failed - exiting"); 656 exit(1); 657 } 658 659 if (setenv("SHELL", pwd->pw_shell, 1) == -1) 660 err(1, "setenv: cannot set SHELL=%s", pwd->pw_shell); 661 if (setenv("HOME", pwd->pw_dir, 1) == -1) 662 err(1, "setenv: cannot set HOME=%s", pwd->pw_dir); 663 if (term != NULL && *term != '\0') { 664 if (setenv("TERM", term, 1) == -1) /* Preset overrides */ 665 err(1, "setenv: cannot set TERM=%s", term); 666 } 667 else { 668 if (setenv("TERM", stypeof(tty), 0) == -1) /* Fallback doesn't */ 669 err(1, "setenv: cannot set TERM=%s", stypeof(tty)); 670 } 671 if (setenv("LOGNAME", username, 1) == -1) 672 err(1, "setenv: cannot set LOGNAME=%s", username); 673 if (setenv("USER", username, 1) == -1) 674 err(1, "setenv: cannot set USER=%s", username); 675 if (setenv("PATH", rootlogin ? _PATH_STDPATH : _PATH_DEFPATH, 0) == -1) 676 err(1, "setenv: cannot set PATH=%s", rootlogin ? _PATH_STDPATH : _PATH_DEFPATH); 677 678 if (!quietlog) { 679 char *cw; 680 681 cw = login_getcapstr(lc, "copyright", NULL, NULL); 682 if (cw != NULL && access(cw, F_OK) == 0) 683 motd(cw); 684 else 685 (void)printf("%s\n\t%s %s\n", 686 "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994", 687 "The Regents of the University of California. ", 688 "All rights reserved."); 689 690 (void)printf("\n"); 691 692 cw = login_getcapstr(lc, "welcome", NULL, NULL); 693 if (cw == NULL || access(cw, F_OK) != 0) 694 cw = _PATH_MOTDFILE; 695 motd(cw); 696 697 cw = getenv("MAIL"); /* $MAIL may have been set by class */ 698 if (cw != NULL) 699 strlcpy(tbuf, cw, sizeof(tbuf)); 700 else 701 snprintf(tbuf, sizeof(tbuf), "%s/%s", _PATH_MAILDIR, 702 pwd->pw_name); 703 if (stat(tbuf, &st) == 0 && st.st_size != 0) 704 (void)printf("You have %smail.\n", 705 (st.st_mtime > st.st_atime) ? "new " : ""); 706 } 707 708 login_close(lc); 709 710 (void)signal(SIGALRM, SIG_DFL); 711 (void)signal(SIGQUIT, SIG_DFL); 712 (void)signal(SIGINT, SIG_DFL); 713 (void)signal(SIGTSTP, SIG_IGN); 714 715 if (changepass) { 716 if (system(_PATH_CHPASS) != 0) 717 sleepexit(1); 718 } 719 720 /* 721 * Login shells have a leading '-' in front of argv[0] 722 */ 723 if (snprintf(tbuf, sizeof(tbuf), "-%s", 724 (p = strrchr(pwd->pw_shell, '/')) ? p + 1 : pwd->pw_shell) >= 725 sizeof(tbuf)) { 726 syslog(LOG_ERR, "user: %s: shell exceeds maximum pathname size", 727 username); 728 errx(1, "shell exceeds maximum pathname size"); 729 } 730 731 execlp(shell, tbuf, (char *)0); 732 err(1, "%s", shell); 733 } 734 735 static int 736 auth_traditional(void) 737 { 738 int rval; 739 char *p; 740 char *ep; 741 char *salt; 742 743 rval = 1; 744 salt = pwd != NULL ? pwd->pw_passwd : "xx"; 745 746 p = getpass(passwd_prompt); 747 ep = crypt(p, salt); 748 749 if (pwd) { 750 if (!p[0] && pwd->pw_passwd[0]) 751 ep = ":"; 752 if (strcmp(ep, pwd->pw_passwd) == 0) 753 rval = 0; 754 } 755 756 /* clear entered password */ 757 memset(p, 0, strlen(p)); 758 return rval; 759 } 760 761 #ifdef USE_PAM 762 /* 763 * Attempt to authenticate the user using PAM. Returns 0 if the user is 764 * authenticated, or 1 if not authenticated. If some sort of PAM system 765 * error occurs (e.g., the "/etc/pam.conf" file is missing) then this 766 * function returns -1. This can be used as an indication that we should 767 * fall back to a different authentication mechanism. 768 */ 769 static int 770 auth_pam(void) 771 { 772 const char *tmpl_user; 773 const void *item; 774 int rval; 775 int e; 776 static struct pam_conv conv; 777 778 conv.conv = &openpam_ttyconv; 779 780 if ((e = pam_start("login", username, &conv, &pamh)) != PAM_SUCCESS) { 781 syslog(LOG_ERR, "pam_start: %s", pam_strerror(pamh, e)); 782 return -1; 783 } 784 if ((e = pam_set_item(pamh, PAM_TTY, tty)) != PAM_SUCCESS) { 785 syslog(LOG_ERR, "pam_set_item(PAM_TTY): %s", 786 pam_strerror(pamh, e)); 787 return -1; 788 } 789 if (hostname != NULL && 790 (e = pam_set_item(pamh, PAM_RHOST, full_hostname)) != PAM_SUCCESS) { 791 syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s", 792 pam_strerror(pamh, e)); 793 return -1; 794 } 795 e = pam_authenticate(pamh, 0); 796 switch (e) { 797 798 case PAM_SUCCESS: 799 /* 800 * With PAM we support the concept of a "template" 801 * user. The user enters a login name which is 802 * authenticated by PAM, usually via a remote service 803 * such as RADIUS or TACACS+. If authentication 804 * succeeds, a different but related "template" name 805 * is used for setting the credentials, shell, and 806 * home directory. The name the user enters need only 807 * exist on the remote authentication server, but the 808 * template name must be present in the local password 809 * database. 810 * 811 * This is supported by two various mechanisms in the 812 * individual modules. However, from the application's 813 * point of view, the template user is always passed 814 * back as a changed value of the PAM_USER item. 815 */ 816 if ((e = pam_get_item(pamh, PAM_USER, &item)) == 817 PAM_SUCCESS) { 818 tmpl_user = (const char *) item; 819 if (strcmp(username, tmpl_user) != 0) 820 pwd = getpwnam(tmpl_user); 821 } else 822 syslog(LOG_ERR, "Couldn't get PAM_USER: %s", 823 pam_strerror(pamh, e)); 824 rval = 0; 825 break; 826 827 case PAM_AUTH_ERR: 828 case PAM_USER_UNKNOWN: 829 case PAM_MAXTRIES: 830 rval = 1; 831 break; 832 833 default: 834 syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e)); 835 rval = -1; 836 break; 837 } 838 839 if (rval == 0) { 840 e = pam_acct_mgmt(pamh, 0); 841 if (e == PAM_NEW_AUTHTOK_REQD) { 842 e = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK); 843 if (e != PAM_SUCCESS) { 844 syslog(LOG_ERR, "pam_chauthtok: %s", 845 pam_strerror(pamh, e)); 846 rval = 1; 847 } 848 } else if (e != PAM_SUCCESS) { 849 rval = 1; 850 } 851 } 852 853 if (rval != 0) { 854 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) { 855 syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); 856 } 857 pamh = NULL; 858 } 859 return rval; 860 } 861 862 static int 863 export_pam_environment(void) 864 { 865 char **pp; 866 867 for (pp = environ_pam; *pp != NULL; pp++) { 868 if (ok_to_export(*pp)) { 869 if (putenv(*pp) == -1) 870 err(1, "putenv: cannot set %s", *pp); 871 } 872 free(*pp); 873 } 874 return PAM_SUCCESS; 875 } 876 877 /* 878 * Sanity checks on PAM environmental variables: 879 * - Make sure there is an '=' in the string. 880 * - Make sure the string doesn't run on too long. 881 * - Do not export certain variables. This list was taken from the 882 * Solaris pam_putenv(3) man page. 883 */ 884 static int 885 ok_to_export(const char *s) 886 { 887 static const char *noexport[] = { 888 "SHELL", "HOME", "LOGNAME", "MAIL", "CDPATH", 889 "IFS", "PATH", NULL 890 }; 891 const char **pp; 892 size_t n; 893 894 if (strlen(s) > 1024 || strchr(s, '=') == NULL) 895 return 0; 896 if (strncmp(s, "LD_", 3) == 0) 897 return 0; 898 for (pp = noexport; *pp != NULL; pp++) { 899 n = strlen(*pp); 900 if (s[n] == '=' && strncmp(s, *pp, n) == 0) 901 return 0; 902 } 903 return 1; 904 } 905 #endif /* USE_PAM */ 906 907 static void 908 usage(void) 909 { 910 911 (void)fprintf(stderr, "usage: login [-fp] [-h hostname] [username]\n"); 912 exit(1); 913 } 914 915 /* 916 * Allow for authentication style and/or kerberos instance 917 */ 918 919 #define NBUFSIZ UT_NAMESIZE + 64 920 921 void 922 getloginname(void) 923 { 924 int ch; 925 char *p; 926 static char nbuf[NBUFSIZ]; 927 928 for (;;) { 929 (void)printf("%s", prompt); 930 for (p = nbuf; (ch = getchar()) != '\n'; ) { 931 if (ch == EOF) { 932 badlogin(username); 933 exit(0); 934 } 935 if (p < nbuf + (NBUFSIZ - 1)) 936 *p++ = ch; 937 } 938 if (p > nbuf) { 939 if (nbuf[0] == '-') 940 (void)fprintf(stderr, 941 "login names may not start with '-'.\n"); 942 else { 943 *p = '\0'; 944 username = nbuf; 945 break; 946 } 947 } 948 } 949 } 950 951 int 952 rootterm(char *ttyn) 953 { 954 struct ttyent *t; 955 956 return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE); 957 } 958 959 volatile int motdinterrupt; 960 961 void 962 sigint(int signo __unused) 963 { 964 motdinterrupt = 1; 965 } 966 967 void 968 motd(char *motdfile) 969 { 970 int fd, nchars; 971 sig_t oldint; 972 char tbuf[256]; 973 974 if ((fd = open(motdfile, O_RDONLY, 0)) < 0) 975 return; 976 motdinterrupt = 0; 977 oldint = signal(SIGINT, sigint); 978 while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0 && !motdinterrupt) 979 (void)write(fileno(stdout), tbuf, nchars); 980 (void)signal(SIGINT, oldint); 981 (void)close(fd); 982 } 983 984 /* ARGSUSED */ 985 void 986 timedout(int signo) 987 { 988 989 longjmp(timeout_buf, signo); 990 } 991 992 993 void 994 dolastlog(int quiet) 995 { 996 struct lastlog ll; 997 int fd; 998 999 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) { 1000 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 1001 if (!quiet) { 1002 if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) && 1003 ll.ll_time != 0) { 1004 (void)printf("Last login: %.*s ", 1005 24-5, (char *)ctime(&ll.ll_time)); 1006 if (*ll.ll_host != '\0') 1007 (void)printf("from %.*s\n", 1008 (int)sizeof(ll.ll_host), 1009 ll.ll_host); 1010 else 1011 (void)printf("on %.*s\n", 1012 (int)sizeof(ll.ll_line), 1013 ll.ll_line); 1014 } 1015 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 1016 } 1017 memset((void *)&ll, 0, sizeof(ll)); 1018 (void)time(&ll.ll_time); 1019 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line)); 1020 if (hostname) 1021 (void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host)); 1022 (void)write(fd, (char *)&ll, sizeof(ll)); 1023 (void)close(fd); 1024 } else { 1025 syslog(LOG_ERR, "cannot open %s: %m", _PATH_LASTLOG); 1026 } 1027 } 1028 1029 void 1030 badlogin(char *name) 1031 { 1032 1033 if (failures == 0) 1034 return; 1035 if (hostname) { 1036 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s", 1037 failures, failures > 1 ? "S" : "", full_hostname); 1038 syslog(LOG_AUTHPRIV|LOG_NOTICE, 1039 "%d LOGIN FAILURE%s FROM %s, %s", 1040 failures, failures > 1 ? "S" : "", full_hostname, name); 1041 } else { 1042 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s", 1043 failures, failures > 1 ? "S" : "", tty); 1044 syslog(LOG_AUTHPRIV|LOG_NOTICE, 1045 "%d LOGIN FAILURE%s ON %s, %s", 1046 failures, failures > 1 ? "S" : "", tty, name); 1047 } 1048 failures = 0; 1049 } 1050 1051 #undef UNKNOWN 1052 #define UNKNOWN "su" 1053 1054 char * 1055 stypeof(char *ttyid) 1056 { 1057 struct ttyent *t; 1058 1059 if (ttyid != NULL && *ttyid != '\0') { 1060 t = getttynam(ttyid); 1061 if (t != NULL && t->ty_type != NULL) 1062 return (t->ty_type); 1063 } 1064 return (UNKNOWN); 1065 } 1066 1067 void 1068 refused(char *msg, char *rtype, int lout) 1069 { 1070 1071 if (msg != NULL) 1072 printf("%s.\n", msg); 1073 if (hostname) 1074 syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) FROM %s ON TTY %s", 1075 pwd->pw_name, rtype, full_hostname, tty); 1076 else 1077 syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) ON TTY %s", 1078 pwd->pw_name, rtype, tty); 1079 if (lout) 1080 sleepexit(1); 1081 } 1082 1083 void 1084 sleepexit(int eval) 1085 { 1086 1087 (void)sleep(5); 1088 exit(eval); 1089 } 1090