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 34#if 0 35static char copyright[] = 36"@(#) Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994\n\ 37 The Regents of the University of California. All rights reserved.\n"; 38#endif 39 40#ifndef lint 41#if 0 42static char sccsid[] = "@(#)login.c 8.4 (Berkeley) 4/2/94"; 43#endif 44static const char rcsid[] = 45 "$FreeBSD$"; 46#endif /* not lint */ 47 48/* 49 * login [ name ] 50 * login -h hostname (for telnetd, etc.) 51 * login -f name (for pre-authenticated login: datakit, xterm, etc.) 52 */ 53 54#include <sys/copyright.h> 55#include <sys/param.h> 56#include <sys/stat.h> 57#include <sys/socket.h> 58#include <sys/time.h> 59#include <sys/resource.h> 60#include <sys/file.h> 61#include <netinet/in.h> 62#include <arpa/inet.h> 63 64#include <err.h> 65#include <errno.h> 66#include <grp.h> 67#include <libutil.h> 68#include <login_cap.h> 69#include <netdb.h> 70#include <pwd.h> 71#include <setjmp.h> 72#include <signal.h> 73#include <stdio.h> 74#include <stdlib.h> 75#include <string.h> 76#include <syslog.h> 77#include <ttyent.h> 78#include <unistd.h> 79#include <utmpx.h> 80 81#ifdef USE_PAM 82#include <security/pam_appl.h> 83#include <security/openpam.h> 84#include <sys/wait.h> 85#endif /* USE_PAM */ 86 87#include "pathnames.h" 88 89void badlogin(char *); 90void checknologin(void); 91void dolastlog(int); 92void getloginname(void); 93void motd(const char *); 94int rootterm(char *); 95void sigint(int); 96void sleepexit(int); 97void refused(char *,char *,int); 98char *stypeof(char *); 99void timedout(int); 100int login_access(char *, char *); 101void login_fbtab(char *, uid_t, gid_t); 102 103#ifdef USE_PAM 104static int auth_pam(void); 105static int export_pam_environment(void); 106static int ok_to_export(const char *); 107 108static pam_handle_t *pamh = NULL; 109static char **environ_pam; 110 111#define PAM_END { \ 112 if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \ 113 syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e)); \ 114 if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS) \ 115 syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e)); \ 116 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) \ 117 syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); \ 118} 119#endif 120 121static int auth_traditional(void); 122static void usage(void); 123 124#define TTYGRPNAME "tty" /* name of group to own ttys */ 125#define DEFAULT_BACKOFF 3 126#define DEFAULT_RETRIES 10 127#define DEFAULT_PROMPT "login: " 128#define DEFAULT_PASSWD_PROMPT "Password:" 129 130/* 131 * This bounds the time given to login. Not a define so it can 132 * be patched on machines where it's too small. 133 */ 134u_int timeout = 300; 135 136/* Buffer for signal handling of timeout */ 137jmp_buf timeout_buf; 138 139struct passwd *pwd; 140int failures; 141char *term, *envinit[1], *hostname, *tty, *username; 142const char *passwd_prompt, *prompt; 143char full_hostname[MAXHOSTNAMELEN]; 144 145int 146main(argc, argv) 147 int argc; 148 char *argv[]; 149{ 150 extern char **environ; 151 struct group *gr; 152 struct stat st; 153 struct timeval tp; 154 struct utmpx utmp; 155 int rootok, retries, backoff; 156 int ask, ch, cnt, fflag, hflag, pflag, quietlog, rootlogin, rval; 157 int changepass; 158 time_t warntime; 159 uid_t uid, euid; 160 gid_t egid; 161 char *p, *ttyn; 162 char tbuf[MAXPATHLEN + 2]; 163 char tname[sizeof(_PATH_TTY) + 10]; 164 const char *shell = NULL; 165 login_cap_t *lc = NULL; 166 int UT_HOSTSIZE = sizeof(utmp.ut_host); 167 int UT_NAMESIZE = sizeof(utmp.ut_user); 168#ifdef USE_PAM 169 pid_t pid; 170 int e; 171#endif /* USE_PAM */ 172 173 (void)signal(SIGQUIT, SIG_IGN); 174 (void)signal(SIGINT, SIG_IGN); 175 (void)signal(SIGHUP, SIG_IGN); 176 if (setjmp(timeout_buf)) { 177 if (failures) 178 badlogin(tbuf); 179 (void)fprintf(stderr, "Login timed out after %d seconds\n", 180 timeout); 181 exit(0); 182 } 183 (void)signal(SIGALRM, timedout); 184 (void)alarm(timeout); 185 (void)setpriority(PRIO_PROCESS, 0, 0); 186 187 openlog("login", LOG_ODELAY, LOG_AUTH); 188 189 /* 190 * -p is used by getty to tell login not to destroy the environment 191 * -f is used to skip a second login authentication 192 * -h is used by other servers to pass the name of the remote 193 * host to login so that it may be placed in utmp and wtmp 194 */ 195 *full_hostname = '\0'; 196 term = NULL; 197 198 fflag = hflag = pflag = 0; 199 uid = getuid(); 200 euid = geteuid(); 201 egid = getegid(); 202 while ((ch = getopt(argc, argv, "fh:p")) != -1) 203 switch (ch) { 204 case 'f': 205 fflag = 1; 206 break; 207 case 'h': 208 if (uid) 209 errx(1, "-h option: %s", strerror(EPERM)); 210 hflag = 1; 211 if (strlcpy(full_hostname, optarg, 212 sizeof(full_hostname)) >= sizeof(full_hostname)) 213 errx(1, "-h option: %s: exceeds maximum " 214 "hostname size", optarg); 215 216 trimdomain(optarg, UT_HOSTSIZE); 217 218 if (strlen(optarg) > UT_HOSTSIZE) { 219 struct addrinfo hints, *res; 220 int ga_err; 221 222 memset(&hints, 0, sizeof(hints)); 223 hints.ai_family = AF_UNSPEC; 224 ga_err = getaddrinfo(optarg, NULL, &hints, 225 &res); 226 if (ga_err == 0) { 227 char hostbuf[MAXHOSTNAMELEN]; 228 229 getnameinfo(res->ai_addr, 230 res->ai_addrlen, 231 hostbuf, 232 sizeof(hostbuf), NULL, 0, 233 NI_NUMERICHOST); 234 optarg = strdup(hostbuf); 235 if (optarg == NULL) { 236 syslog(LOG_NOTICE, 237 "strdup(): %m"); 238 sleepexit(1); 239 } 240 } else 241 optarg = "invalid hostname"; 242 if (res != NULL) 243 freeaddrinfo(res); 244 } 245 hostname = optarg; 246 break; 247 case 'p': 248 pflag = 1; 249 break; 250 case '?': 251 default: 252 if (!uid) 253 syslog(LOG_ERR, "invalid flag %c", ch); 254 usage(); 255 } 256 argc -= optind; 257 argv += optind; 258 259 if (*argv) { 260 username = *argv; 261 ask = 0; 262 } else 263 ask = 1; 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 /* 411 * Switching needed for NFS with root access disabled. 412 * 413 * XXX: This change fails to modify the additional groups for the 414 * process, and as such, may restrict rights normally granted 415 * through those groups. 416 */ 417 (void)setegid(pwd->pw_gid); 418 (void)seteuid(rootlogin ? 0 : pwd->pw_uid); 419 if (!*pwd->pw_dir || chdir(pwd->pw_dir) < 0) { 420 if (login_getcapbool(lc, "requirehome", 0)) 421 refused("Home directory not available", "HOMEDIR", 1); 422 if (chdir("/") < 0) 423 refused("Cannot find root directory", "ROOTDIR", 1); 424 if (!quietlog || *pwd->pw_dir) 425 printf("No home directory.\nLogging in with home = \"/\".\n"); 426 pwd->pw_dir = "/"; 427 } 428 (void)seteuid(euid); 429 (void)setegid(egid); 430 if (!quietlog) 431 quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0; 432 433 if (pwd->pw_change || pwd->pw_expire) 434 (void)gettimeofday(&tp, (struct timezone *)NULL); 435 436#define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */ 437 438 warntime = login_getcaptime(lc, "warnexpire", DEFAULT_WARN, 439 DEFAULT_WARN); 440 441 if (pwd->pw_expire) { 442 if (tp.tv_sec >= pwd->pw_expire) { 443 refused("Sorry -- your account has expired", "EXPIRED", 444 1); 445 } else if (pwd->pw_expire - tp.tv_sec < warntime && !quietlog) 446 (void)printf("Warning: your account expires on %s", 447 ctime(&pwd->pw_expire)); 448 } 449 450 warntime = login_getcaptime(lc, "warnpassword", DEFAULT_WARN, 451 DEFAULT_WARN); 452 453 changepass = 0; 454 if (pwd->pw_change) { 455 if (tp.tv_sec >= pwd->pw_change) { 456 (void)printf("Sorry -- your password has expired.\n"); 457 changepass = 1; 458 syslog(LOG_INFO, "%s Password expired - forcing change", 459 pwd->pw_name); 460 } else if (pwd->pw_change - tp.tv_sec < warntime && !quietlog) 461 (void)printf("Warning: your password expires on %s", 462 ctime(&pwd->pw_change)); 463 } 464 465 if (lc != NULL) { 466 if (hostname) { 467 struct addrinfo hints, *res; 468 int ga_err; 469 470 memset(&hints, 0, sizeof(hints)); 471 hints.ai_family = AF_UNSPEC; 472 ga_err = getaddrinfo(full_hostname, NULL, &hints, 473 &res); 474 if (ga_err == 0) { 475 char hostbuf[MAXHOSTNAMELEN]; 476 477 getnameinfo(res->ai_addr, res->ai_addrlen, 478 hostbuf, sizeof(hostbuf), NULL, 0, 479 NI_NUMERICHOST); 480 if ((optarg = strdup(hostbuf)) == NULL) { 481 syslog(LOG_NOTICE, "strdup(): %m"); 482 sleepexit(1); 483 } 484 } else 485 optarg = NULL; 486 if (res != NULL) 487 freeaddrinfo(res); 488 if (!auth_hostok(lc, full_hostname, optarg)) 489 refused("Permission denied", "HOST", 1); 490 } 491 492 if (!auth_ttyok(lc, tty)) 493 refused("Permission denied", "TTY", 1); 494 495 if (!auth_timeok(lc, time(NULL))) 496 refused("Logins not available right now", "TIME", 1); 497 } 498 shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell); 499 if (*pwd->pw_shell == '\0') 500 pwd->pw_shell = _PATH_BSHELL; 501 if (*shell == '\0') /* Not overridden */ 502 shell = pwd->pw_shell; 503 if ((shell = strdup(shell)) == NULL) { 504 syslog(LOG_NOTICE, "strdup(): %m"); 505 sleepexit(1); 506 } 507 508#ifdef LOGIN_ACCESS 509 if (login_access(pwd->pw_name, hostname ? full_hostname : tty) == 0) 510 refused("Permission denied", "ACCESS", 1); 511#endif /* LOGIN_ACCESS */ 512 513#if 1 514 ulog_login(tty, username, hostname); 515#else 516 /* Nothing else left to fail -- really log in. */ 517 memset((void *)&utmp, 0, sizeof(utmp)); 518 (void)gettimeofday(&utmp.ut_tv, NULL); 519 (void)strncpy(utmp.ut_user, username, sizeof(utmp.ut_user)); 520 if (hostname) 521 (void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host)); 522 (void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line)); 523 login(&utmp); 524#endif 525 526 dolastlog(quietlog); 527 528 /* 529 * Set device protections, depending on what terminal the 530 * user is logged in. This feature is used on Suns to give 531 * console users better privacy. 532 */ 533 login_fbtab(tty, pwd->pw_uid, pwd->pw_gid); 534 535 /* 536 * Clear flags of the tty. None should be set, and when the 537 * user sets them otherwise, this can cause the chown to fail. 538 * Since it isn't clear that flags are useful on character 539 * devices, we just clear them. 540 */ 541 if (chflags(ttyn, 0) && errno != EOPNOTSUPP) 542 syslog(LOG_ERR, "chflags(%s): %m", ttyn); 543 if (chown(ttyn, pwd->pw_uid, 544 (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid)) 545 syslog(LOG_ERR, "chown(%s): %m", ttyn); 546 547 548 /* 549 * Preserve TERM if it happens to be already set. 550 */ 551 if ((term = getenv("TERM")) != NULL) { 552 if ((term = strdup(term)) == NULL) { 553 syslog(LOG_NOTICE, 554 "strdup(): %m"); 555 sleepexit(1); 556 } 557 } 558 559 /* 560 * Exclude cons/vt/ptys only, assume dialup otherwise 561 * TODO: Make dialup tty determination a library call 562 * for consistency (finger etc.) 563 */ 564 if (hostname==NULL && isdialuptty(tty)) 565 syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name); 566 567#ifdef LOGALL 568 /* 569 * Syslog each successful login, so we don't have to watch hundreds 570 * of wtmp or lastlogin files. 571 */ 572 if (hostname) 573 syslog(LOG_INFO, "login from %s on %s as %s", 574 full_hostname, tty, pwd->pw_name); 575 else 576 syslog(LOG_INFO, "login on %s as %s", 577 tty, pwd->pw_name); 578#endif 579 580 /* 581 * If fflag is on, assume caller/authenticator has logged root login. 582 */ 583 if (rootlogin && fflag == 0) 584 { 585 if (hostname) 586 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s", 587 username, tty, full_hostname); 588 else 589 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s", 590 username, tty); 591 } 592 593 /* 594 * Destroy environment unless user has requested its preservation. 595 * We need to do this before setusercontext() because that may 596 * set or reset some environment variables. 597 */ 598 if (!pflag) 599 environ = envinit; 600 601 /* 602 * PAM modules might add supplementary groups during pam_setcred(). 603 */ 604 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) { 605 syslog(LOG_ERR, "setusercontext() failed - exiting"); 606 exit(1); 607 } 608 609#ifdef USE_PAM 610 if (pamh) { 611 if ((e = pam_open_session(pamh, 0)) != PAM_SUCCESS) { 612 syslog(LOG_ERR, "pam_open_session: %s", 613 pam_strerror(pamh, e)); 614 } else if ((e = pam_setcred(pamh, PAM_ESTABLISH_CRED)) 615 != PAM_SUCCESS) { 616 syslog(LOG_ERR, "pam_setcred: %s", 617 pam_strerror(pamh, e)); 618 } 619 620 /* 621 * Add any environmental variables that the 622 * PAM modules may have set. 623 * Call *after* opening session! 624 */ 625 if (pamh) { 626 environ_pam = pam_getenvlist(pamh); 627 if (environ_pam) 628 export_pam_environment(); 629 } 630 631 /* 632 * We must fork() before setuid() because we need to call 633 * pam_close_session() as root. 634 */ 635 pid = fork(); 636 if (pid < 0) { 637 err(1, "fork"); 638 PAM_END; 639 exit(0); 640 } else if (pid) { 641 /* parent - wait for child to finish, then cleanup 642 session */ 643 wait(NULL); 644 PAM_END; 645 exit(0); 646 } else { 647 if ((e = pam_end(pamh, 0)) != PAM_SUCCESS) 648 syslog(LOG_ERR, "pam_end: %s", 649 pam_strerror(pamh, e)); 650 } 651 } 652#endif /* USE_PAM */ 653 654 /* 655 * We don't need to be root anymore, so 656 * set the user and session context 657 */ 658 if (setlogin(username) != 0) { 659 syslog(LOG_ERR, "setlogin(%s): %m - exiting", username); 660 exit(1); 661 } 662 if (setusercontext(lc, pwd, pwd->pw_uid, 663 LOGIN_SETALL & ~(LOGIN_SETLOGIN|LOGIN_SETGROUP)) != 0) { 664 syslog(LOG_ERR, "setusercontext() failed - exiting"); 665 exit(1); 666 } 667 668 (void)setenv("SHELL", pwd->pw_shell, 1); 669 (void)setenv("HOME", pwd->pw_dir, 1); 670 if (term != NULL && *term != '\0') 671 (void)setenv("TERM", term, 1); /* Preset overrides */ 672 else { 673 (void)setenv("TERM", stypeof(tty), 0); /* Fallback doesn't */ 674 } 675 (void)setenv("LOGNAME", username, 1); 676 (void)setenv("USER", username, 1); 677 (void)setenv("PATH", rootlogin ? _PATH_STDPATH : _PATH_DEFPATH, 0); 678 679 if (!quietlog) { 680 const char *cw; 681 682 cw = login_getcapstr(lc, "copyright", NULL, NULL); 683 if (cw != NULL && access(cw, F_OK) == 0) 684 motd(cw); 685 else 686 (void)printf("%s\n\t%s %s\n", 687 "Copyright (c) 1980, 1983, 1986, 1988, 1990, 1991, 1993, 1994", 688 "The Regents of the University of California. ", 689 "All rights reserved."); 690 691 (void)printf("\n"); 692 693 cw = login_getcapstr(lc, "welcome", NULL, NULL); 694 if (cw == NULL || access(cw, F_OK) != 0) 695 cw = _PATH_MOTDFILE; 696 motd(cw); 697 698 cw = getenv("MAIL"); /* $MAIL may have been set by class */ 699 if (cw != NULL) 700 strlcpy(tbuf, cw, sizeof(tbuf)); 701 else 702 snprintf(tbuf, sizeof(tbuf), "%s/%s", _PATH_MAILDIR, 703 pwd->pw_name); 704 if (stat(tbuf, &st) == 0 && st.st_size != 0) 705 (void)printf("You have %smail.\n", 706 (st.st_mtime > st.st_atime) ? "new " : ""); 707 } 708 709 login_close(lc); 710 711 (void)signal(SIGALRM, SIG_DFL); 712 (void)signal(SIGQUIT, SIG_DFL); 713 (void)signal(SIGINT, SIG_DFL); 714 (void)signal(SIGTSTP, SIG_IGN); 715 716 /* 717 * Login shells have a leading '-' in front of argv[0] 718 */ 719 if (snprintf(tbuf, sizeof(tbuf), "-%s", 720 (p = strrchr(pwd->pw_shell, '/')) ? p + 1 : pwd->pw_shell) >= 721 sizeof(tbuf)) { 722 syslog(LOG_ERR, "user: %s: shell exceeds maximum pathname size", 723 username); 724 errx(1, "shell exceeds maximum pathname size"); 725 } 726 727 execlp(shell, tbuf, (char *)0); 728 err(1, "%s", shell); 729} 730 731static int 732auth_traditional() 733{ 734 int rval; 735 char *p; 736 char *ep; 737 char *salt; 738 739 rval = 1; 740 salt = pwd != NULL ? pwd->pw_passwd : "xx"; 741 742 p = getpass(passwd_prompt); 743 ep = crypt(p, salt); 744 745 if (pwd) { 746 if (!p[0] && pwd->pw_passwd[0]) 747 ep = ":"; 748 if (strcmp(ep, pwd->pw_passwd) == 0) 749 rval = 0; 750 } 751 752 /* clear entered password */ 753 memset(p, 0, strlen(p)); 754 return rval; 755} 756 757#ifdef USE_PAM 758/* 759 * Attempt to authenticate the user using PAM. Returns 0 if the user is 760 * authenticated, or 1 if not authenticated. If some sort of PAM system 761 * error occurs (e.g., the "/etc/pam.conf" file is missing) then this 762 * function returns -1. This can be used as an indication that we should 763 * fall back to a different authentication mechanism. 764 */ 765static int 766auth_pam() 767{ 768 const char *tmpl_user; 769 const void *item; 770 int rval; 771 int e; 772 static struct pam_conv conv = { openpam_ttyconv, NULL }; 773 774 if ((e = pam_start("login", username, &conv, &pamh)) != PAM_SUCCESS) { 775 syslog(LOG_ERR, "pam_start: %s", pam_strerror(pamh, e)); 776 return -1; 777 } 778 if ((e = pam_set_item(pamh, PAM_TTY, tty)) != PAM_SUCCESS) { 779 syslog(LOG_ERR, "pam_set_item(PAM_TTY): %s", 780 pam_strerror(pamh, e)); 781 return -1; 782 } 783 if (hostname != NULL && 784 (e = pam_set_item(pamh, PAM_RHOST, full_hostname)) != PAM_SUCCESS) { 785 syslog(LOG_ERR, "pam_set_item(PAM_RHOST): %s", 786 pam_strerror(pamh, e)); 787 return -1; 788 } 789 e = pam_authenticate(pamh, 0); 790 switch (e) { 791 792 case PAM_SUCCESS: 793 /* 794 * With PAM we support the concept of a "template" 795 * user. The user enters a login name which is 796 * authenticated by PAM, usually via a remote service 797 * such as RADIUS or TACACS+. If authentication 798 * succeeds, a different but related "template" name 799 * is used for setting the credentials, shell, and 800 * home directory. The name the user enters need only 801 * exist on the remote authentication server, but the 802 * template name must be present in the local password 803 * database. 804 * 805 * This is supported by two various mechanisms in the 806 * individual modules. However, from the application's 807 * point of view, the template user is always passed 808 * back as a changed value of the PAM_USER item. 809 */ 810 if ((e = pam_get_item(pamh, PAM_USER, &item)) == 811 PAM_SUCCESS) { 812 tmpl_user = (const char *) item; 813 if (strcmp(username, tmpl_user) != 0) 814 pwd = getpwnam(tmpl_user); 815 } else 816 syslog(LOG_ERR, "Couldn't get PAM_USER: %s", 817 pam_strerror(pamh, e)); 818 rval = 0; 819 break; 820 821 case PAM_AUTH_ERR: 822 case PAM_USER_UNKNOWN: 823 case PAM_MAXTRIES: 824 rval = 1; 825 break; 826 827 default: 828 syslog(LOG_ERR, "pam_authenticate: %s", pam_strerror(pamh, e)); 829 rval = -1; 830 break; 831 } 832 833 if (rval == 0) { 834 e = pam_acct_mgmt(pamh, 0); 835 if (e == PAM_NEW_AUTHTOK_REQD) { 836 e = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK); 837 if (e != PAM_SUCCESS) { 838 syslog(LOG_ERR, "pam_chauthtok: %s", 839 pam_strerror(pamh, e)); 840 rval = 1; 841 } 842 } else if (e != PAM_SUCCESS) { 843 rval = 1; 844 } 845 } 846 847 if (rval != 0) { 848 if ((e = pam_end(pamh, e)) != PAM_SUCCESS) { 849 syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); 850 } 851 pamh = NULL; 852 } 853 return rval; 854} 855 856static int 857export_pam_environment() 858{ 859 char **pp; 860 861 for (pp = environ_pam; *pp != NULL; pp++) { 862 if (ok_to_export(*pp)) 863 (void) putenv(*pp); 864 free(*pp); 865 } 866 return PAM_SUCCESS; 867} 868 869/* 870 * Sanity checks on PAM environmental variables: 871 * - Make sure there is an '=' in the string. 872 * - Make sure the string doesn't run on too long. 873 * - Do not export certain variables. This list was taken from the 874 * Solaris pam_putenv(3) man page. 875 */ 876static int 877ok_to_export(s) 878 const char *s; 879{ 880 static const char *noexport[] = { 881 "SHELL", "HOME", "LOGNAME", "MAIL", "CDPATH", 882 "IFS", "PATH", NULL 883 }; 884 const char **pp; 885 size_t n; 886 887 if (strlen(s) > 1024 || strchr(s, '=') == NULL) 888 return 0; 889 if (strncmp(s, "LD_", 3) == 0) 890 return 0; 891 for (pp = noexport; *pp != NULL; pp++) { 892 n = strlen(*pp); 893 if (s[n] == '=' && strncmp(s, *pp, n) == 0) 894 return 0; 895 } 896 return 1; 897} 898#endif /* USE_PAM */ 899 900static void 901usage() 902{ 903 904 (void)fprintf(stderr, "usage: login [-fp] [-h hostname] [username]\n"); 905 exit(1); 906} 907 908/* 909 * Allow for authentication style and/or kerberos instance 910 */ 911 912#define NBUFSIZ 128 // XXX was UT_NAMESIZE + 64 913 914void 915getloginname() 916{ 917 int ch; 918 char *p; 919 static char nbuf[NBUFSIZ]; 920 921 for (;;) { 922 (void)printf("%s", prompt); 923 for (p = nbuf; (ch = getchar()) != '\n'; ) { 924 if (ch == EOF) { 925 badlogin(username); 926 exit(0); 927 } 928 if (p < nbuf + (NBUFSIZ - 1)) 929 *p++ = ch; 930 } 931 if (p > nbuf) { 932 if (nbuf[0] == '-') 933 (void)fprintf(stderr, 934 "login names may not start with '-'.\n"); 935 else { 936 *p = '\0'; 937 username = nbuf; 938 break; 939 } 940 } 941 } 942} 943 944int 945rootterm(ttyn) 946 char *ttyn; 947{ 948 struct ttyent *t; 949 950 return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE); 951} 952 953volatile int motdinterrupt; 954 955void 956sigint(signo) 957 int signo __unused; 958{ 959 motdinterrupt = 1; 960} 961 962void 963motd(motdfile) 964 const char *motdfile; 965{ 966 int fd, nchars; 967 sig_t oldint; 968 char tbuf[256]; 969 970 if ((fd = open(motdfile, O_RDONLY, 0)) < 0) 971 return; 972 motdinterrupt = 0; 973 oldint = signal(SIGINT, sigint); 974 while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0 && !motdinterrupt) 975 (void)write(fileno(stdout), tbuf, nchars); 976 (void)signal(SIGINT, oldint); 977 (void)close(fd); 978} 979 980/* ARGSUSED */ 981void 982timedout(signo) 983 int signo; 984{ 985 986 longjmp(timeout_buf, signo); 987} 988 989 990void 991dolastlog(quiet) 992 int quiet; 993{ 994#if 0 /* XXX not implemented after utmp->utmpx change */ 995 struct lastlog ll; 996 int fd; 997 998 if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) { 999 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 1000 if (!quiet) { 1001 if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) && 1002 ll.ll_time != 0) { 1003 (void)printf("Last login: %.*s ", 1004 24-5, (char *)ctime(&ll.ll_time)); 1005 if (*ll.ll_host != '\0') 1006 (void)printf("from %.*s\n", 1007 (int)sizeof(ll.ll_host), 1008 ll.ll_host); 1009 else 1010 (void)printf("on %.*s\n", 1011 (int)sizeof(ll.ll_line), 1012 ll.ll_line); 1013 } 1014 (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET); 1015 } 1016 memset((void *)&ll, 0, sizeof(ll)); 1017 (void)time(&ll.ll_time); 1018 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line)); 1019 if (hostname) 1020 (void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host)); 1021 (void)write(fd, (char *)&ll, sizeof(ll)); 1022 (void)close(fd); 1023 } else { 1024 syslog(LOG_ERR, "cannot open %s: %m", _PATH_LASTLOG); 1025 } 1026#endif 1027} 1028 1029void 1030badlogin(name) 1031 char *name; 1032{ 1033 1034 if (failures == 0) 1035 return; 1036 if (hostname) { 1037 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s", 1038 failures, failures > 1 ? "S" : "", full_hostname); 1039 syslog(LOG_AUTHPRIV|LOG_NOTICE, 1040 "%d LOGIN FAILURE%s FROM %s, %s", 1041 failures, failures > 1 ? "S" : "", full_hostname, name); 1042 } else { 1043 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s", 1044 failures, failures > 1 ? "S" : "", tty); 1045 syslog(LOG_AUTHPRIV|LOG_NOTICE, 1046 "%d LOGIN FAILURE%s ON %s, %s", 1047 failures, failures > 1 ? "S" : "", tty, name); 1048 } 1049 failures = 0; 1050} 1051 1052#undef UNKNOWN 1053#define UNKNOWN "su" 1054 1055char * 1056stypeof(ttyid) 1057 char *ttyid; 1058{ 1059 struct ttyent *t; 1060 1061 if (ttyid != NULL && *ttyid != '\0') { 1062 t = getttynam(ttyid); 1063 if (t != NULL && t->ty_type != NULL) 1064 return (t->ty_type); 1065 } 1066 return (UNKNOWN); 1067} 1068 1069void 1070refused(msg, rtype, lout) 1071 char *msg; 1072 char *rtype; 1073 int lout; 1074{ 1075 1076 if (msg != NULL) 1077 printf("%s.\n", msg); 1078 if (hostname) 1079 syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) FROM %s ON TTY %s", 1080 pwd->pw_name, rtype, full_hostname, tty); 1081 else 1082 syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) ON TTY %s", 1083 pwd->pw_name, rtype, tty); 1084 if (lout) 1085 sleepexit(1); 1086} 1087 1088void 1089sleepexit(eval) 1090 int eval; 1091{ 1092 1093 (void)sleep(5); 1094 exit(eval); 1095} 1096