pico-login.c revision 104744 
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: head/release/picobsd/tinyware/login/pico-login.c 104744 2002-10-10 00:32:55Z alfred $";
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 <utmp.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/* wrapper for KAME-special getnameinfo() */
90#ifndef NI_WITHSCOPEID
91#define	NI_WITHSCOPEID	0
92#endif
93
94void	 badlogin(char *);
95void	 checknologin(void);
96void	 dolastlog(int);
97void	 getloginname(void);
98void	 motd(const char *);
99int	 rootterm(char *);
100void	 sigint(int);
101void	 sleepexit(int);
102void	 refused(char *,char *,int);
103char	*stypeof(char *);
104void	 timedout(int);
105int	 login_access(char *, char *);
106void     login_fbtab(char *, uid_t, gid_t);
107
108#ifdef USE_PAM
109static int auth_pam(void);
110static int export_pam_environment(void);
111static int ok_to_export(const char *);
112
113static pam_handle_t *pamh = NULL;
114static char **environ_pam;
115
116#define PAM_END { \
117	if ((e = pam_setcred(pamh, PAM_DELETE_CRED)) != PAM_SUCCESS) \
118		syslog(LOG_ERR, "pam_setcred: %s", pam_strerror(pamh, e)); \
119	if ((e = pam_close_session(pamh,0)) != PAM_SUCCESS) \
120		syslog(LOG_ERR, "pam_close_session: %s", pam_strerror(pamh, e)); \
121	if ((e = pam_end(pamh, e)) != PAM_SUCCESS) \
122		syslog(LOG_ERR, "pam_end: %s", pam_strerror(pamh, e)); \
123}
124#endif
125
126static int auth_traditional(void);
127extern void login(struct utmp *);
128static void usage(void);
129
130#define	TTYGRPNAME	"tty"		/* name of group to own ttys */
131#define	DEFAULT_BACKOFF	3
132#define	DEFAULT_RETRIES	10
133#define	DEFAULT_PROMPT		"login: "
134#define	DEFAULT_PASSWD_PROMPT	"Password:"
135
136/*
137 * This bounds the time given to login.  Not a define so it can
138 * be patched on machines where it's too small.
139 */
140u_int	timeout = 300;
141
142/* Buffer for signal handling of timeout */
143jmp_buf timeout_buf;
144
145struct	passwd *pwd;
146int	failures;
147char	*term, *envinit[1], *hostname, *tty, *username;
148const char *passwd_prompt, *prompt;
149char    full_hostname[MAXHOSTNAMELEN];
150
151int
152main(argc, argv)
153	int argc;
154	char *argv[];
155{
156	extern char **environ;
157	struct group *gr;
158	struct stat st;
159	struct timeval tp;
160	struct utmp utmp;
161	int rootok, retries, backoff;
162	int ask, ch, cnt, fflag, hflag, pflag, quietlog, rootlogin, rval;
163	int changepass;
164	time_t warntime;
165	uid_t uid, euid;
166	gid_t egid;
167	char *p, *ttyn;
168	char tbuf[MAXPATHLEN + 2];
169	char tname[sizeof(_PATH_TTY) + 10];
170	const char *shell = NULL;
171	login_cap_t *lc = NULL;
172#ifdef USE_PAM
173	pid_t pid;
174	int e;
175#endif /* USE_PAM */
176
177	(void)signal(SIGQUIT, SIG_IGN);
178	(void)signal(SIGINT, SIG_IGN);
179	(void)signal(SIGHUP, SIG_IGN);
180	if (setjmp(timeout_buf)) {
181		if (failures)
182			badlogin(tbuf);
183		(void)fprintf(stderr, "Login timed out after %d seconds\n",
184		    timeout);
185		exit(0);
186	}
187	(void)signal(SIGALRM, timedout);
188	(void)alarm(timeout);
189	(void)setpriority(PRIO_PROCESS, 0, 0);
190
191	openlog("login", LOG_ODELAY, LOG_AUTH);
192
193	/*
194	 * -p is used by getty to tell login not to destroy the environment
195	 * -f is used to skip a second login authentication
196	 * -h is used by other servers to pass the name of the remote
197	 *    host to login so that it may be placed in utmp and wtmp
198	 */
199	*full_hostname = '\0';
200	term = NULL;
201
202	fflag = hflag = pflag = 0;
203	uid = getuid();
204	euid = geteuid();
205	egid = getegid();
206	while ((ch = getopt(argc, argv, "fh:p")) != -1)
207		switch (ch) {
208		case 'f':
209			fflag = 1;
210			break;
211		case 'h':
212			if (uid)
213				errx(1, "-h option: %s", strerror(EPERM));
214			hflag = 1;
215			if (strlcpy(full_hostname, optarg,
216			    sizeof(full_hostname)) >= sizeof(full_hostname))
217				errx(1, "-h option: %s: exceeds maximum "
218				    "hostname size", optarg);
219
220			trimdomain(optarg, UT_HOSTSIZE);
221
222			if (strlen(optarg) > UT_HOSTSIZE) {
223				struct addrinfo hints, *res;
224				int ga_err;
225
226				memset(&hints, 0, sizeof(hints));
227				hints.ai_family = AF_UNSPEC;
228				ga_err = getaddrinfo(optarg, NULL, &hints,
229				    &res);
230				if (ga_err == 0) {
231					char hostbuf[MAXHOSTNAMELEN];
232
233					getnameinfo(res->ai_addr,
234					    res->ai_addrlen,
235					    hostbuf,
236					    sizeof(hostbuf), NULL, 0,
237					    NI_NUMERICHOST|
238					    NI_WITHSCOPEID);
239					optarg = strdup(hostbuf);
240					if (optarg == NULL) {
241						syslog(LOG_NOTICE,
242						    "strdup(): %m");
243						sleepexit(1);
244					}
245				} else
246					optarg = "invalid hostname";
247				if (res != NULL)
248					freeaddrinfo(res);
249			}
250			hostname = optarg;
251			break;
252		case 'p':
253			pflag = 1;
254			break;
255		case '?':
256		default:
257			if (!uid)
258				syslog(LOG_ERR, "invalid flag %c", ch);
259			usage();
260		}
261	argc -= optind;
262	argv += optind;
263
264	if (*argv) {
265		username = *argv;
266		ask = 0;
267	} else
268		ask = 1;
269
270	for (cnt = getdtablesize(); cnt > 2; cnt--)
271		(void)close(cnt);
272
273	ttyn = ttyname(STDIN_FILENO);
274	if (ttyn == NULL || *ttyn == '\0') {
275		(void)snprintf(tname, sizeof(tname), "%s??", _PATH_TTY);
276		ttyn = tname;
277	}
278	if ((tty = strrchr(ttyn, '/')) != NULL)
279		++tty;
280	else
281		tty = ttyn;
282
283	/*
284	 * Get "login-retries" & "login-backoff" from default class
285	 */
286	lc = login_getclass(NULL);
287	prompt = login_getcapstr(lc, "prompt", DEFAULT_PROMPT, DEFAULT_PROMPT);
288	passwd_prompt = login_getcapstr(lc, "passwd_prompt",
289	    DEFAULT_PASSWD_PROMPT, DEFAULT_PASSWD_PROMPT);
290	retries = login_getcapnum(lc, "login-retries", DEFAULT_RETRIES,
291	    DEFAULT_RETRIES);
292	backoff = login_getcapnum(lc, "login-backoff", DEFAULT_BACKOFF,
293	    DEFAULT_BACKOFF);
294	login_close(lc);
295	lc = NULL;
296
297	for (cnt = 0;; ask = 1) {
298		if (ask) {
299			fflag = 0;
300			getloginname();
301		}
302		rootlogin = 0;
303		rootok = rootterm(tty); /* Default (auth may change) */
304
305		if (strlen(username) > UT_NAMESIZE)
306			username[UT_NAMESIZE] = '\0';
307
308		/*
309		 * Note if trying multiple user names; log failures for
310		 * previous user name, but don't bother logging one failure
311		 * for nonexistent name (mistyped username).
312		 */
313		if (failures && strcmp(tbuf, username)) {
314			if (failures > (pwd ? 0 : 1))
315				badlogin(tbuf);
316		}
317		(void)strlcpy(tbuf, username, sizeof(tbuf));
318
319		pwd = getpwnam(username);
320
321		/*
322		 * if we have a valid account name, and it doesn't have a
323		 * password, or the -f option was specified and the caller
324		 * is root or the caller isn't changing their uid, don't
325		 * authenticate.
326		 */
327		if (pwd != NULL) {
328			if (pwd->pw_uid == 0)
329				rootlogin = 1;
330
331			if (fflag && (uid == (uid_t)0 ||
332			    uid == (uid_t)pwd->pw_uid)) {
333				/* already authenticated */
334				break;
335			} else if (pwd->pw_passwd[0] == '\0') {
336				if (!rootlogin || rootok) {
337					/* pretend password okay */
338					rval = 0;
339					goto ttycheck;
340				}
341			}
342		}
343
344		fflag = 0;
345
346		(void)setpriority(PRIO_PROCESS, 0, -4);
347
348#ifdef USE_PAM
349		/*
350		 * Try to authenticate using PAM.  If a PAM system error
351		 * occurs, perhaps because of a botched configuration,
352		 * then fall back to using traditional Unix authentication.
353		 */
354		if ((rval = auth_pam()) == -1)
355#endif /* USE_PAM */
356			rval = auth_traditional();
357
358		(void)setpriority(PRIO_PROCESS, 0, 0);
359
360#ifdef USE_PAM
361		/*
362		 * PAM authentication may have changed "pwd" to the
363		 * entry for the template user.  Check again to see if
364		 * this is a root login after all.
365		 */
366		if (pwd != NULL && pwd->pw_uid == 0)
367			rootlogin = 1;
368#endif /* USE_PAM */
369
370	ttycheck:
371		/*
372		 * If trying to log in as root without Kerberos,
373		 * but with insecure terminal, refuse the login attempt.
374		 */
375		if (pwd && !rval) {
376			if (rootlogin && !rootok)
377				refused(NULL, "NOROOT", 0);
378			else	/* valid password & authenticated */
379				break;
380		}
381
382		(void)printf("Login incorrect\n");
383		failures++;
384
385		/*
386		 * we allow up to 'retry' (10) tries,
387		 * but after 'backoff' (3) we start backing off
388		 */
389		if (++cnt > backoff) {
390			if (cnt >= retries) {
391				badlogin(username);
392				sleepexit(1);
393			}
394			sleep((u_int)((cnt - backoff) * 5));
395		}
396	}
397
398	/* committed to login -- turn off timeout */
399	(void)alarm((u_int)0);
400	(void)signal(SIGHUP, SIG_DFL);
401
402	endpwent();
403
404	/*
405	 * Establish the login class.
406	 */
407	lc = login_getpwclass(pwd);
408
409	/* if user not super-user, check for disabled logins */
410	if (!rootlogin)
411		auth_checknologin(lc);
412
413	quietlog = login_getcapbool(lc, "hushlogin", 0);
414	/*
415	 * Switching needed for NFS with root access disabled.
416	 *
417	 * XXX: This change fails to modify the additional groups for the
418	 * process, and as such, may restrict rights normally granted
419	 * through those groups.
420	 */
421	(void)setegid(pwd->pw_gid);
422	(void)seteuid(rootlogin ? 0 : pwd->pw_uid);
423	if (!*pwd->pw_dir || chdir(pwd->pw_dir) < 0) {
424		if (login_getcapbool(lc, "requirehome", 0))
425			refused("Home directory not available", "HOMEDIR", 1);
426		if (chdir("/") < 0)
427			refused("Cannot find root directory", "ROOTDIR", 1);
428		if (!quietlog || *pwd->pw_dir)
429			printf("No home directory.\nLogging in with home = \"/\".\n");
430		pwd->pw_dir = "/";
431	}
432	(void)seteuid(euid);
433	(void)setegid(egid);
434	if (!quietlog)
435		quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0;
436
437	if (pwd->pw_change || pwd->pw_expire)
438		(void)gettimeofday(&tp, (struct timezone *)NULL);
439
440#define	DEFAULT_WARN  (2L * 7L * 86400L)  /* Two weeks */
441
442	warntime = login_getcaptime(lc, "warnexpire", DEFAULT_WARN,
443	    DEFAULT_WARN);
444
445	if (pwd->pw_expire) {
446		if (tp.tv_sec >= pwd->pw_expire) {
447			refused("Sorry -- your account has expired", "EXPIRED",
448			    1);
449		} else if (pwd->pw_expire - tp.tv_sec < warntime && !quietlog)
450			(void)printf("Warning: your account expires on %s",
451			    ctime(&pwd->pw_expire));
452	}
453
454	warntime = login_getcaptime(lc, "warnpassword", DEFAULT_WARN,
455	    DEFAULT_WARN);
456
457	changepass = 0;
458	if (pwd->pw_change) {
459		if (tp.tv_sec >= pwd->pw_change) {
460			(void)printf("Sorry -- your password has expired.\n");
461			changepass = 1;
462			syslog(LOG_INFO, "%s Password expired - forcing change",
463			    pwd->pw_name);
464		} else if (pwd->pw_change - tp.tv_sec < warntime && !quietlog)
465			(void)printf("Warning: your password expires on %s",
466			    ctime(&pwd->pw_change));
467	}
468
469	if (lc != NULL) {
470		if (hostname) {
471			struct addrinfo hints, *res;
472			int ga_err;
473
474			memset(&hints, 0, sizeof(hints));
475			hints.ai_family = AF_UNSPEC;
476			ga_err = getaddrinfo(full_hostname, NULL, &hints,
477					     &res);
478			if (ga_err == 0) {
479				char hostbuf[MAXHOSTNAMELEN];
480
481				getnameinfo(res->ai_addr, res->ai_addrlen,
482				    hostbuf, sizeof(hostbuf), NULL, 0,
483				    NI_NUMERICHOST|NI_WITHSCOPEID);
484				if ((optarg = strdup(hostbuf)) == NULL) {
485					syslog(LOG_NOTICE, "strdup(): %m");
486					sleepexit(1);
487				}
488			} else
489				optarg = NULL;
490			if (res != NULL)
491				freeaddrinfo(res);
492			if (!auth_hostok(lc, full_hostname, optarg))
493				refused("Permission denied", "HOST", 1);
494		}
495
496		if (!auth_ttyok(lc, tty))
497			refused("Permission denied", "TTY", 1);
498
499		if (!auth_timeok(lc, time(NULL)))
500			refused("Logins not available right now", "TIME", 1);
501	}
502        shell = login_getcapstr(lc, "shell", pwd->pw_shell, pwd->pw_shell);
503	if (*pwd->pw_shell == '\0')
504		pwd->pw_shell = _PATH_BSHELL;
505	if (*shell == '\0')   /* Not overridden */
506		shell = pwd->pw_shell;
507	if ((shell = strdup(shell)) == NULL) {
508		syslog(LOG_NOTICE, "strdup(): %m");
509		sleepexit(1);
510	}
511
512#ifdef LOGIN_ACCESS
513	if (login_access(pwd->pw_name, hostname ? full_hostname : tty) == 0)
514		refused("Permission denied", "ACCESS", 1);
515#endif /* LOGIN_ACCESS */
516
517	/* Nothing else left to fail -- really log in. */
518	memset((void *)&utmp, 0, sizeof(utmp));
519	(void)time(&utmp.ut_time);
520	(void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
521	if (hostname)
522		(void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
523	(void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
524	login(&utmp);
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, "chmod(%s): %m", ttyn);
543	if (chown(ttyn, pwd->pw_uid,
544	    (gr = getgrnam(TTYGRPNAME)) ? gr->gr_gid : pwd->pw_gid))
545		syslog(LOG_ERR, "chmod(%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		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	struct lastlog ll;
995	int fd;
996
997	if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
998		(void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);
999		if (!quiet) {
1000			if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
1001			    ll.ll_time != 0) {
1002				(void)printf("Last login: %.*s ",
1003				    24-5, (char *)ctime(&ll.ll_time));
1004				if (*ll.ll_host != '\0')
1005					(void)printf("from %.*s\n",
1006					    (int)sizeof(ll.ll_host),
1007					    ll.ll_host);
1008				else
1009					(void)printf("on %.*s\n",
1010					    (int)sizeof(ll.ll_line),
1011					    ll.ll_line);
1012			}
1013			(void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);
1014		}
1015		memset((void *)&ll, 0, sizeof(ll));
1016		(void)time(&ll.ll_time);
1017		(void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
1018		if (hostname)
1019			(void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
1020		(void)write(fd, (char *)&ll, sizeof(ll));
1021		(void)close(fd);
1022	} else {
1023		syslog(LOG_ERR, "cannot open %s: %m", _PATH_LASTLOG);
1024	}
1025}
1026
1027void
1028badlogin(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
1053char *
1054stypeof(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
1067void
1068refused(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
1086void
1087sleepexit(eval)
1088	int eval;
1089{
1090
1091	(void)sleep(5);
1092	exit(eval);
1093}
1094