1/*- 2 * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994 3 * The Regents of the University of California. All rights reserved. 4 * Copyright (c) 2002 Networks Associates Technologies, Inc. 5 * All rights reserved. 6 * 7 * Portions of this software were developed for the FreeBSD Project by 8 * ThinkSec AS and NAI Labs, the Security Research Division of Network 9 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 10 * ("CBOSS"), as part of the DARPA CHATS research program. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 */ 40 41#if 0 42#ifndef lint 43static char sccsid[] = "@(#)login.c 8.4 (Berkeley) 4/2/94"; 44#endif 45#endif 46 47#include <sys/cdefs.h> 48__FBSDID("$FreeBSD$"); 49 50/* 51 * login [ name ] 52 * login -h hostname (for telnetd, etc.) 53 * login -f name (for pre-authenticated login: datakit, xterm, etc.) 54 */ 55 56#include <sys/param.h> 57#include <sys/file.h> 58#include <sys/stat.h> 59#include <sys/time.h> 60#include <sys/resource.h> 61#include <sys/wait.h> 62 63#include <err.h> 64#include <errno.h> 65#include <grp.h> 66#include <libutil.h> 67#include <login_cap.h> 68#include <pwd.h> 69#include <setjmp.h> 70#include <signal.h> 71#include <stdio.h> 72#include <stdlib.h> 73#include <string.h> 74#include <syslog.h> 75#include <ttyent.h> 76#include <unistd.h> 77 78#include <security/pam_appl.h> 79#include <security/openpam.h> 80 81#include "login.h" 82#include "pathnames.h" 83 84static int auth_pam(void); 85static void bail(int, int); 86static int export(const char *); 87static void export_pam_environment(void); 88static int motd(const char *); 89static void badlogin(char *); 90static char *getloginname(void); 91static void pam_syslog(const char *); 92static void pam_cleanup(void); 93static void refused(const char *, const char *, int); 94static const char *stypeof(char *); 95static void sigint(int); 96static void timedout(int); 97static void usage(void); 98 99#define TTYGRPNAME "tty" /* group to own ttys */ 100#define DEFAULT_BACKOFF 3 101#define DEFAULT_RETRIES 10 102#define DEFAULT_PROMPT "login: " 103#define DEFAULT_PASSWD_PROMPT "Password:" 104#define TERM_UNKNOWN "su" 105#define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */ 106#define NO_SLEEP_EXIT 0 107#define SLEEP_EXIT 5 108 109/* 110 * This bounds the time given to login. Not a define so it can 111 * be patched on machines where it's too small. 112 */ 113static u_int timeout = 300; 114 115/* Buffer for signal handling of timeout */ 116static jmp_buf timeout_buf; 117 118struct passwd *pwd; 119static int failures; 120 121static char *envinit[1]; /* empty environment list */ 122 123/* 124 * Command line flags and arguments 125 */ 126static int fflag; /* -f: do not perform authentication */ 127static int hflag; /* -h: login from remote host */ 128static char *hostname; /* hostname from command line */ 129static int pflag; /* -p: preserve environment */ 130 131/* 132 * User name 133 */ 134static char *username; /* user name */ 135static char *olduser; /* previous user name */ 136 137/* 138 * Prompts 139 */ 140static char default_prompt[] = DEFAULT_PROMPT; 141static const char *prompt; 142static char default_passwd_prompt[] = DEFAULT_PASSWD_PROMPT; 143static const char *passwd_prompt; 144 145static char *tty; 146 147/* 148 * PAM data 149 */ 150static pam_handle_t *pamh = NULL; 151static struct pam_conv pamc = { openpam_ttyconv, NULL }; 152static int pam_err; 153static int pam_silent = PAM_SILENT; 154static int pam_cred_established; 155static int pam_session_established; 156 157int 158main(int argc, char *argv[]) 159{ 160 struct group *gr; 161 struct stat st; 162 int retries, backoff; 163 int ask, ch, cnt, quietlog, rootlogin, rval; 164 uid_t uid, euid; 165 gid_t egid; 166 char *term; 167 char *p, *ttyn; 168 char tname[sizeof(_PATH_TTY) + 10]; 169 char *arg0; 170 const char *tp; 171 const char *shell = NULL; 172 login_cap_t *lc = NULL; 173 login_cap_t *lc_user = NULL; 174 pid_t pid; 175#ifdef USE_BSM_AUDIT 176 char auditsuccess = 1; 177#endif 178 179 (void)signal(SIGQUIT, SIG_IGN); 180 (void)signal(SIGINT, SIG_IGN); 181 (void)signal(SIGHUP, SIG_IGN); 182 if (setjmp(timeout_buf)) { 183 if (failures) 184 badlogin(username); 185 (void)fprintf(stderr, "Login timed out after %d seconds\n", 186 timeout); 187 bail(NO_SLEEP_EXIT, 0); 188 } 189 (void)signal(SIGALRM, timedout); 190 (void)alarm(timeout); 191 (void)setpriority(PRIO_PROCESS, 0, 0); 192 193 openlog("login", LOG_ODELAY, LOG_AUTH); 194 195 uid = getuid(); 196 euid = geteuid(); 197 egid = getegid(); 198 199 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 != 0) 206 errx(1, "-h option: %s", strerror(EPERM)); 207 if (strlen(optarg) >= MAXHOSTNAMELEN) 208 errx(1, "-h option: %s: exceeds maximum " 209 "hostname size", optarg); 210 hflag = 1; 211 hostname = optarg; 212 break; 213 case 'p': 214 pflag = 1; 215 break; 216 case '?': 217 default: 218 if (uid == 0) 219 syslog(LOG_ERR, "invalid flag %c", ch); 220 usage(); 221 } 222 argc -= optind; 223 argv += optind; 224 225 if (argc > 0) { 226 username = strdup(*argv); 227 if (username == NULL) 228 err(1, "strdup()"); 229 ask = 0; 230 } else { 231 ask = 1; 232 } 233 234 setproctitle("-%s", getprogname()); 235 236 closefrom(3); 237 238 /* 239 * Get current TTY 240 */ 241 ttyn = ttyname(STDIN_FILENO); 242 if (ttyn == NULL || *ttyn == '\0') { 243 (void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY); 244 ttyn = tname; 245 } 246 if (strncmp(ttyn, _PATH_DEV, sizeof _PATH_DEV - 1) == 0) 247 tty = ttyn + sizeof _PATH_DEV - 1; 248 else 249 tty = ttyn; 250 251 /* 252 * Get "login-retries" & "login-backoff" from default class 253 */ 254 lc = login_getclass(NULL); 255 prompt = login_getcapstr(lc, "login_prompt", 256 default_prompt, default_prompt); 257 passwd_prompt = login_getcapstr(lc, "passwd_prompt", 258 default_passwd_prompt, default_passwd_prompt); 259 retries = login_getcapnum(lc, "login-retries", 260 DEFAULT_RETRIES, DEFAULT_RETRIES); 261 backoff = login_getcapnum(lc, "login-backoff", 262 DEFAULT_BACKOFF, DEFAULT_BACKOFF); 263 login_close(lc); 264 lc = NULL; 265 266 /* 267 * Try to authenticate the user until we succeed or time out. 268 */ 269 for (cnt = 0;; ask = 1) { 270 if (ask) { 271 fflag = 0; 272 if (olduser != NULL) 273 free(olduser); 274 olduser = username; 275 username = getloginname(); 276 } 277 rootlogin = 0; 278 279 /* 280 * Note if trying multiple user names; log failures for 281 * previous user name, but don't bother logging one failure 282 * for nonexistent name (mistyped username). 283 */ 284 if (failures && strcmp(olduser, username) != 0) { 285 if (failures > (pwd ? 0 : 1)) 286 badlogin(olduser); 287 } 288 289 /* 290 * Load the PAM policy and set some variables 291 */ 292 pam_err = pam_start("login", username, &pamc, &pamh); 293 if (pam_err != PAM_SUCCESS) { 294 pam_syslog("pam_start()"); 295#ifdef USE_BSM_AUDIT 296 au_login_fail("PAM Error", 1); 297#endif 298 bail(NO_SLEEP_EXIT, 1); 299 } 300 pam_err = pam_set_item(pamh, PAM_TTY, tty); 301 if (pam_err != PAM_SUCCESS) { 302 pam_syslog("pam_set_item(PAM_TTY)"); 303#ifdef USE_BSM_AUDIT 304 au_login_fail("PAM Error", 1); 305#endif 306 bail(NO_SLEEP_EXIT, 1); 307 } 308 pam_err = pam_set_item(pamh, PAM_RHOST, hostname); 309 if (pam_err != PAM_SUCCESS) { 310 pam_syslog("pam_set_item(PAM_RHOST)"); 311#ifdef USE_BSM_AUDIT 312 au_login_fail("PAM Error", 1); 313#endif 314 bail(NO_SLEEP_EXIT, 1); 315 } 316 317 pwd = getpwnam(username); 318 if (pwd != NULL && pwd->pw_uid == 0) 319 rootlogin = 1; 320 321 /* 322 * If the -f option was specified and the caller is 323 * root or the caller isn't changing their uid, don't 324 * authenticate. 325 */ 326 if (pwd != NULL && fflag && 327 (uid == (uid_t)0 || uid == (uid_t)pwd->pw_uid)) { 328 /* already authenticated */ 329 rval = 0; 330#ifdef USE_BSM_AUDIT 331 auditsuccess = 0; /* opened a terminal window only */ 332#endif 333 } else { 334 fflag = 0; 335 (void)setpriority(PRIO_PROCESS, 0, -4); 336 rval = auth_pam(); 337 (void)setpriority(PRIO_PROCESS, 0, 0); 338 } 339 340 if (pwd && rval == 0) 341 break; 342 343 pam_cleanup(); 344 345 /* 346 * We are not exiting here, but this corresponds to a failed 347 * login event, so set exitstatus to 1. 348 */ 349#ifdef USE_BSM_AUDIT 350 au_login_fail("Login incorrect", 1); 351#endif 352 353 (void)printf("Login incorrect\n"); 354 failures++; 355 356 pwd = NULL; 357 358 /* 359 * Allow up to 'retry' (10) attempts, but start 360 * backing off after 'backoff' (3) attempts. 361 */ 362 if (++cnt > backoff) { 363 if (cnt >= retries) { 364 badlogin(username); 365 bail(SLEEP_EXIT, 1); 366 } 367 sleep((u_int)((cnt - backoff) * 5)); 368 } 369 } 370 371 /* committed to login -- turn off timeout */ 372 (void)alarm((u_int)0); 373 (void)signal(SIGHUP, SIG_DFL); 374 375 endpwent(); 376 377#ifdef USE_BSM_AUDIT 378 /* Audit successful login. */ 379 if (auditsuccess) 380 au_login_success(); 381#endif 382 383 /* 384 * This needs to happen before login_getpwclass to support 385 * home directories on GSS-API authenticated NFS where the 386 * kerberos credentials need to be saved so that the kernel 387 * can authenticate to the NFS server. 388 */ 389 pam_err = pam_setcred(pamh, pam_silent|PAM_ESTABLISH_CRED); 390 if (pam_err != PAM_SUCCESS) { 391 pam_syslog("pam_setcred()"); 392 bail(NO_SLEEP_EXIT, 1); 393 } 394 pam_cred_established = 1; 395 396 /* 397 * Establish the login class. 398 */ 399 lc = login_getpwclass(pwd); 400 lc_user = login_getuserclass(pwd); 401 402 if (!(quietlog = login_getcapbool(lc_user, "hushlogin", 0))) 403 quietlog = login_getcapbool(lc, "hushlogin", 0); 404 405 /* 406 * Switching needed for NFS with root access disabled. 407 * 408 * XXX: This change fails to modify the additional groups for the 409 * process, and as such, may restrict rights normally granted 410 * through those groups. 411 */ 412 (void)setegid(pwd->pw_gid); 413 (void)seteuid(rootlogin ? 0 : pwd->pw_uid); 414 if (!*pwd->pw_dir || chdir(pwd->pw_dir) < 0) { 415 if (login_getcapbool(lc, "requirehome", 0)) 416 refused("Home directory not available", "HOMEDIR", 1); 417 if (chdir("/") < 0) 418 refused("Cannot find root directory", "ROOTDIR", 1); 419 if (!quietlog || *pwd->pw_dir) 420 printf("No home directory.\nLogging in with home = \"/\".\n"); 421 pwd->pw_dir = strdup("/"); 422 if (pwd->pw_dir == NULL) { 423 syslog(LOG_NOTICE, "strdup(): %m"); 424 bail(SLEEP_EXIT, 1); 425 } 426 } 427 (void)seteuid(euid); 428 (void)setegid(egid); 429 if (!quietlog) { 430 quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0; 431 if (!quietlog) 432 pam_silent = 0; 433 } 434 435 shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell); 436 if (*pwd->pw_shell == '\0') 437 pwd->pw_shell = strdup(_PATH_BSHELL); 438 if (pwd->pw_shell == NULL) { 439 syslog(LOG_NOTICE, "strdup(): %m"); 440 bail(SLEEP_EXIT, 1); 441 } 442 if (*shell == '\0') /* Not overridden */ 443 shell = pwd->pw_shell; 444 if ((shell = strdup(shell)) == NULL) { 445 syslog(LOG_NOTICE, "strdup(): %m"); 446 bail(SLEEP_EXIT, 1); 447 } 448 449 /* 450 * Set device protections, depending on what terminal the 451 * user is logged in. This feature is used on Suns to give 452 * console users better privacy. 453 */ 454 login_fbtab(tty, pwd->pw_uid, pwd->pw_gid); 455 456 /* 457 * Clear flags of the tty. None should be set, and when the 458 * user sets them otherwise, this can cause the chown to fail. 459 * Since it isn't clear that flags are useful on character 460 * devices, we just clear them. 461 * 462 * We don't log in the case of EOPNOTSUPP because dev might be 463 * on NFS, which doesn't support chflags. 464 * 465 * We don't log in the EROFS because that means that /dev is on 466 * a read only file system and we assume that the permissions there 467 * are sane. 468 */ 469 if (ttyn != tname && chflags(ttyn, 0)) 470 if (errno != EOPNOTSUPP && errno != EROFS) 471 syslog(LOG_ERR, "chflags(%s): %m", ttyn); 472 if (ttyn != tname && chown(ttyn, pwd->pw_uid, 473 (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid)) 474 if (errno != EROFS) 475 syslog(LOG_ERR, "chown(%s): %m", ttyn); 476 477 /* 478 * Exclude cons/vt/ptys only, assume dialup otherwise 479 * TODO: Make dialup tty determination a library call 480 * for consistency (finger etc.) 481 */ 482 if (hflag && isdialuptty(tty)) 483 syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name); 484 485#ifdef LOGALL 486 /* 487 * Syslog each successful login, so we don't have to watch 488 * hundreds of wtmp or lastlogin files. 489 */ 490 if (hflag) 491 syslog(LOG_INFO, "login from %s on %s as %s", 492 hostname, tty, pwd->pw_name); 493 else 494 syslog(LOG_INFO, "login on %s as %s", 495 tty, pwd->pw_name); 496#endif 497 498 /* 499 * If fflag is on, assume caller/authenticator has logged root 500 * login. 501 */ 502 if (rootlogin && fflag == 0) { 503 if (hflag) 504 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s FROM %s", 505 username, tty, hostname); 506 else 507 syslog(LOG_NOTICE, "ROOT LOGIN (%s) ON %s", 508 username, tty); 509 } 510 511 /* 512 * Destroy environment unless user has requested its 513 * preservation - but preserve TERM in all cases 514 */ 515 term = getenv("TERM"); 516 if (!pflag) 517 environ = envinit; 518 if (term != NULL) 519 setenv("TERM", term, 0); 520 521 /* 522 * PAM modules might add supplementary groups during pam_setcred(). 523 */ 524 if (setusercontext(lc, pwd, pwd->pw_uid, LOGIN_SETGROUP) != 0) { 525 syslog(LOG_ERR, "setusercontext() failed - exiting"); 526 bail(NO_SLEEP_EXIT, 1); 527 } 528 529 pam_err = pam_setcred(pamh, pam_silent|PAM_REINITIALIZE_CRED); 530 if (pam_err != PAM_SUCCESS) { 531 pam_syslog("pam_setcred()"); 532 bail(NO_SLEEP_EXIT, 1); 533 } 534 535 pam_err = pam_open_session(pamh, pam_silent); 536 if (pam_err != PAM_SUCCESS) { 537 pam_syslog("pam_open_session()"); 538 bail(NO_SLEEP_EXIT, 1); 539 } 540 pam_session_established = 1; 541 542 /* 543 * We must fork() before setuid() because we need to call 544 * pam_close_session() as root. 545 */ 546 pid = fork(); 547 if (pid < 0) { 548 err(1, "fork"); 549 } else if (pid != 0) { 550 /* 551 * Parent: wait for child to finish, then clean up 552 * session. 553 */ 554 int status; 555 setproctitle("-%s [pam]", getprogname()); 556 waitpid(pid, &status, 0); 557 bail(NO_SLEEP_EXIT, 0); 558 } 559 560 /* 561 * NOTICE: We are now in the child process! 562 */ 563 564 /* 565 * Add any environment variables the PAM modules may have set. 566 */ 567 export_pam_environment(); 568 569 /* 570 * We're done with PAM now; our parent will deal with the rest. 571 */ 572 pam_end(pamh, 0); 573 pamh = NULL; 574 575 /* 576 * We don't need to be root anymore, so set the login name and 577 * the UID. 578 */ 579 if (setlogin(username) != 0) { 580 syslog(LOG_ERR, "setlogin(%s): %m - exiting", username); 581 bail(NO_SLEEP_EXIT, 1); 582 } 583 if (setusercontext(lc, pwd, pwd->pw_uid, 584 LOGIN_SETALL & ~(LOGIN_SETLOGIN|LOGIN_SETGROUP)) != 0) { 585 syslog(LOG_ERR, "setusercontext() failed - exiting"); 586 exit(1); 587 } 588 589 (void)setenv("SHELL", pwd->pw_shell, 1); 590 (void)setenv("HOME", pwd->pw_dir, 1); 591 /* Overwrite "term" from login.conf(5) for any known TERM */ 592 if (term == NULL && (tp = stypeof(tty)) != NULL) 593 (void)setenv("TERM", tp, 1); 594 else 595 (void)setenv("TERM", TERM_UNKNOWN, 0); 596 (void)setenv("LOGNAME", username, 1); 597 (void)setenv("USER", username, 1); 598 (void)setenv("PATH", rootlogin ? _PATH_STDPATH : _PATH_DEFPATH, 0); 599 600 if (!quietlog) { 601 const char *cw; 602 603 cw = login_getcapstr(lc, "welcome", NULL, NULL); 604 if (cw != NULL && access(cw, F_OK) == 0) 605 motd(cw); 606 else 607 motd(_PATH_MOTDFILE); 608 609 if (login_getcapbool(lc_user, "nocheckmail", 0) == 0 && 610 login_getcapbool(lc, "nocheckmail", 0) == 0) { 611 char *cx; 612 613 /* $MAIL may have been set by class. */ 614 cx = getenv("MAIL"); 615 if (cx == NULL) { 616 asprintf(&cx, "%s/%s", 617 _PATH_MAILDIR, pwd->pw_name); 618 } 619 if (cx && stat(cx, &st) == 0 && st.st_size != 0) 620 (void)printf("You have %smail.\n", 621 (st.st_mtime > st.st_atime) ? "new " : ""); 622 if (getenv("MAIL") == NULL) 623 free(cx); 624 } 625 } 626 627 login_close(lc_user); 628 login_close(lc); 629 630 (void)signal(SIGALRM, SIG_DFL); 631 (void)signal(SIGQUIT, SIG_DFL); 632 (void)signal(SIGINT, SIG_DFL); 633 (void)signal(SIGTSTP, SIG_IGN); 634 635 /* 636 * Login shells have a leading '-' in front of argv[0] 637 */ 638 p = strrchr(pwd->pw_shell, '/'); 639 if (asprintf(&arg0, "-%s", p ? p + 1 : pwd->pw_shell) >= MAXPATHLEN) { 640 syslog(LOG_ERR, "user: %s: shell exceeds maximum pathname size", 641 username); 642 errx(1, "shell exceeds maximum pathname size"); 643 } else if (arg0 == NULL) { 644 err(1, "asprintf()"); 645 } 646 647 execlp(shell, arg0, (char *)0); 648 err(1, "%s", shell); 649 650 /* 651 * That's it, folks! 652 */ 653} 654 655/* 656 * Attempt to authenticate the user using PAM. Returns 0 if the user is 657 * authenticated, or 1 if not authenticated. If some sort of PAM system 658 * error occurs (e.g., the "/etc/pam.conf" file is missing) then this 659 * function returns -1. This can be used as an indication that we should 660 * fall back to a different authentication mechanism. 661 */ 662static int 663auth_pam(void) 664{ 665 const char *tmpl_user; 666 const void *item; 667 int rval; 668 669 pam_err = pam_authenticate(pamh, pam_silent); 670 switch (pam_err) { 671 672 case PAM_SUCCESS: 673 /* 674 * With PAM we support the concept of a "template" 675 * user. The user enters a login name which is 676 * authenticated by PAM, usually via a remote service 677 * such as RADIUS or TACACS+. If authentication 678 * succeeds, a different but related "template" name 679 * is used for setting the credentials, shell, and 680 * home directory. The name the user enters need only 681 * exist on the remote authentication server, but the 682 * template name must be present in the local password 683 * database. 684 * 685 * This is supported by two various mechanisms in the 686 * individual modules. However, from the application's 687 * point of view, the template user is always passed 688 * back as a changed value of the PAM_USER item. 689 */ 690 pam_err = pam_get_item(pamh, PAM_USER, &item); 691 if (pam_err == PAM_SUCCESS) { 692 tmpl_user = (const char *)item; 693 if (strcmp(username, tmpl_user) != 0) 694 pwd = getpwnam(tmpl_user); 695 } else { 696 pam_syslog("pam_get_item(PAM_USER)"); 697 } 698 rval = 0; 699 break; 700 701 case PAM_AUTH_ERR: 702 case PAM_USER_UNKNOWN: 703 case PAM_MAXTRIES: 704 rval = 1; 705 break; 706 707 default: 708 pam_syslog("pam_authenticate()"); 709 rval = -1; 710 break; 711 } 712 713 if (rval == 0) { 714 pam_err = pam_acct_mgmt(pamh, pam_silent); 715 switch (pam_err) { 716 case PAM_SUCCESS: 717 break; 718 case PAM_NEW_AUTHTOK_REQD: 719 pam_err = pam_chauthtok(pamh, 720 pam_silent|PAM_CHANGE_EXPIRED_AUTHTOK); 721 if (pam_err != PAM_SUCCESS) { 722 pam_syslog("pam_chauthtok()"); 723 rval = 1; 724 } 725 break; 726 default: 727 pam_syslog("pam_acct_mgmt()"); 728 rval = 1; 729 break; 730 } 731 } 732 733 if (rval != 0) { 734 pam_end(pamh, pam_err); 735 pamh = NULL; 736 } 737 return (rval); 738} 739 740/* 741 * Export any environment variables PAM modules may have set 742 */ 743static void 744export_pam_environment(void) 745{ 746 char **pam_env; 747 char **pp; 748 749 pam_env = pam_getenvlist(pamh); 750 if (pam_env != NULL) { 751 for (pp = pam_env; *pp != NULL; pp++) { 752 (void)export(*pp); 753 free(*pp); 754 } 755 } 756} 757 758/* 759 * Perform sanity checks on an environment variable: 760 * - Make sure there is an '=' in the string. 761 * - Make sure the string doesn't run on too long. 762 * - Do not export certain variables. This list was taken from the 763 * Solaris pam_putenv(3) man page. 764 * Then export it. 765 */ 766static int 767export(const char *s) 768{ 769 static const char *noexport[] = { 770 "SHELL", "HOME", "LOGNAME", "MAIL", "CDPATH", 771 "IFS", "PATH", NULL 772 }; 773 char *p; 774 const char **pp; 775 size_t n; 776 777 if (strlen(s) > 1024 || (p = strchr(s, '=')) == NULL) 778 return (0); 779 if (strncmp(s, "LD_", 3) == 0) 780 return (0); 781 for (pp = noexport; *pp != NULL; pp++) { 782 n = strlen(*pp); 783 if (s[n] == '=' && strncmp(s, *pp, n) == 0) 784 return (0); 785 } 786 *p = '\0'; 787 (void)setenv(s, p + 1, 1); 788 *p = '='; 789 return (1); 790} 791 792static void 793usage(void) 794{ 795 796 (void)fprintf(stderr, "usage: login [-fp] [-h hostname] [username]\n"); 797 exit(1); 798} 799 800/* 801 * Prompt user and read login name from stdin. 802 */ 803static char * 804getloginname(void) 805{ 806 char *nbuf, *p; 807 int ch; 808 809 nbuf = malloc(MAXLOGNAME); 810 if (nbuf == NULL) 811 err(1, "malloc()"); 812 do { 813 (void)printf("%s", prompt); 814 for (p = nbuf; (ch = getchar()) != '\n'; ) { 815 if (ch == EOF) { 816 badlogin(username); 817 bail(NO_SLEEP_EXIT, 0); 818 } 819 if (p < nbuf + MAXLOGNAME - 1) 820 *p++ = ch; 821 } 822 } while (p == nbuf); 823 824 *p = '\0'; 825 if (nbuf[0] == '-') { 826 pam_silent = 0; 827 memmove(nbuf, nbuf + 1, strlen(nbuf)); 828 } else { 829 pam_silent = PAM_SILENT; 830 } 831 return nbuf; 832} 833 834/* 835 * SIGINT handler for motd(). 836 */ 837static volatile int motdinterrupt; 838static void 839sigint(int signo __unused) 840{ 841 motdinterrupt = 1; 842} 843 844/* 845 * Display the contents of a file (such as /etc/motd). 846 */ 847static int 848motd(const char *motdfile) 849{ 850 sig_t oldint; 851 FILE *f; 852 int ch; 853 854 if ((f = fopen(motdfile, "r")) == NULL) 855 return (-1); 856 motdinterrupt = 0; 857 oldint = signal(SIGINT, sigint); 858 while ((ch = fgetc(f)) != EOF && !motdinterrupt) 859 putchar(ch); 860 signal(SIGINT, oldint); 861 if (ch != EOF || ferror(f)) { 862 fclose(f); 863 return (-1); 864 } 865 fclose(f); 866 return (0); 867} 868 869/* 870 * SIGALRM handler, to enforce login prompt timeout. 871 * 872 * XXX This can potentially confuse the hell out of PAM. We should 873 * XXX instead implement a conversation function that returns 874 * XXX PAM_CONV_ERR when interrupted by a signal, and have the signal 875 * XXX handler just set a flag. 876 */ 877static void 878timedout(int signo __unused) 879{ 880 881 longjmp(timeout_buf, signo); 882} 883 884static void 885badlogin(char *name) 886{ 887 888 if (failures == 0) 889 return; 890 if (hflag) { 891 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s", 892 failures, failures > 1 ? "S" : "", hostname); 893 syslog(LOG_AUTHPRIV|LOG_NOTICE, 894 "%d LOGIN FAILURE%s FROM %s, %s", 895 failures, failures > 1 ? "S" : "", hostname, name); 896 } else { 897 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s", 898 failures, failures > 1 ? "S" : "", tty); 899 syslog(LOG_AUTHPRIV|LOG_NOTICE, 900 "%d LOGIN FAILURE%s ON %s, %s", 901 failures, failures > 1 ? "S" : "", tty, name); 902 } 903 failures = 0; 904} 905 906const char * 907stypeof(char *ttyid) 908{ 909 struct ttyent *t; 910 911 if (ttyid != NULL && *ttyid != '\0') { 912 t = getttynam(ttyid); 913 if (t != NULL && t->ty_type != NULL) 914 return (t->ty_type); 915 } 916 return (NULL); 917} 918 919static void 920refused(const char *msg, const char *rtype, int lout) 921{ 922 923 if (msg != NULL) 924 printf("%s.\n", msg); 925 if (hflag) 926 syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) FROM %s ON TTY %s", 927 pwd->pw_name, rtype, hostname, tty); 928 else 929 syslog(LOG_NOTICE, "LOGIN %s REFUSED (%s) ON TTY %s", 930 pwd->pw_name, rtype, tty); 931 if (lout) 932 bail(SLEEP_EXIT, 1); 933} 934 935/* 936 * Log a PAM error 937 */ 938static void 939pam_syslog(const char *msg) 940{ 941 syslog(LOG_ERR, "%s: %s", msg, pam_strerror(pamh, pam_err)); 942} 943 944/* 945 * Shut down PAM 946 */ 947static void 948pam_cleanup(void) 949{ 950 951 if (pamh != NULL) { 952 if (pam_session_established) { 953 pam_err = pam_close_session(pamh, 0); 954 if (pam_err != PAM_SUCCESS) 955 pam_syslog("pam_close_session()"); 956 } 957 pam_session_established = 0; 958 if (pam_cred_established) { 959 pam_err = pam_setcred(pamh, pam_silent|PAM_DELETE_CRED); 960 if (pam_err != PAM_SUCCESS) 961 pam_syslog("pam_setcred()"); 962 } 963 pam_cred_established = 0; 964 pam_end(pamh, pam_err); 965 pamh = NULL; 966 } 967} 968 969/* 970 * Exit, optionally after sleeping a few seconds 971 */ 972void 973bail(int sec, int eval) 974{ 975 976 pam_cleanup(); 977#ifdef USE_BSM_AUDIT 978 if (pwd != NULL) 979 audit_logout(); 980#endif 981 (void)sleep(sec); 982 exit(eval); 983} 984