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