xref: /illumos-gate/usr/src/lib/pam_modules/unix_account/unix_acct.c (revision e7cbe64f7a72dae5cb44f100db60ca88f3313c65)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 #include <sys/types.h>
30 #include <sys/wait.h>
31 #include <sys/stat.h>
32 #include <fcntl.h>
33 #include <stdlib.h>
34 #include <security/pam_appl.h>
35 #include <security/pam_modules.h>
36 #include <security/pam_impl.h>
37 #include <syslog.h>
38 #include <pwd.h>
39 #include <shadow.h>
40 #include <lastlog.h>
41 #include <ctype.h>
42 #include <unistd.h>
43 #include <stdlib.h>
44 #include <stdio.h>
45 #include <libintl.h>
46 #include <signal.h>
47 #include <thread.h>
48 #include <synch.h>
49 #include <errno.h>
50 #include <time.h>
51 #include <string.h>
52 #include <crypt.h>
53 #include <assert.h>
54 #include <deflt.h>
55 #include <libintl.h>
56 #include <passwdutil.h>
57 
58 #define	LASTLOG		"/var/adm/lastlog"
59 #define	LOGINADMIN	"/etc/default/login"
60 #define	UNIX_AUTH_DATA		"SUNW-UNIX-AUTH-DATA"
61 #define	UNIX_AUTHTOK_DATA	"SUNW-UNIX-AUTHTOK-DATA"
62 #define	NO_PW		"*NP*"
63 
64 /*
65  * Function Declarations
66  */
67 extern int		defopen(char *);
68 extern char		*defread(char *);
69 extern void		setusershell();
70 extern int		_nfssys(int, void *);
71 
72 typedef struct _unix_authtok_data_ {
73 	int age_status;
74 }unix_authtok_data;
75 
76 /*ARGSUSED*/
77 static void
78 unix_cleanup(
79 	pam_handle_t *pamh,
80 	void *data,
81 	int pam_status)
82 {
83 	free((unix_authtok_data *)data);
84 }
85 
86 /*
87  * check_for_login_inactivity	- Check for login inactivity
88  *
89  */
90 
91 static int
92 check_for_login_inactivity(
93 	uid_t		pw_uid,
94 	struct 	spwd 	*shpwd)
95 {
96 	int		fdl;
97 	struct lastlog	ll;
98 	int		retval;
99 	offset_t	offset;
100 
101 	offset = (offset_t)pw_uid * (offset_t)sizeof (struct lastlog);
102 
103 	if ((fdl = open(LASTLOG, O_RDWR|O_CREAT, 0444)) >= 0) {
104 		/*
105 		 * Read the last login (ll) time
106 		 */
107 		if (llseek(fdl, offset, SEEK_SET) != offset) {
108 			syslog(LOG_ERR, "pam_unix_acct: pam_sm_acct_mgmt: "
109 			    "can't obtain last login info on uid %d "
110 			    "(uid too large)", pw_uid);
111 			return (0);
112 		}
113 
114 		retval = read(fdl, (char *)&ll, sizeof (ll));
115 
116 		/* Check for login inactivity */
117 
118 		if ((shpwd->sp_inact > 0) && (retval == sizeof (ll)) &&
119 		    ll.ll_time) {
120 			/*
121 			 * account inactive too long.
122 			 * and no update password set
123 			 * and no last pwd change date in shadow file
124 			 * and last pwd change more than inactive time
125 			 * then account inactive too long and no access.
126 			 */
127 			if (((time_t)((ll.ll_time / DAY) + shpwd->sp_inact)
128 				< DAY_NOW) &&
129 			    (shpwd->sp_lstchg != 0) &&
130 			    (shpwd->sp_lstchg != -1) &&
131 			    ((shpwd->sp_lstchg + shpwd->sp_inact) < DAY_NOW)) {
132 				/*
133 				 * Account inactive for too long
134 				 */
135 				(void) close(fdl);
136 				return (1);
137 			}
138 		}
139 
140 		(void) close(fdl);
141 	}
142 	return (0);
143 }
144 
145 /*
146  * new_password_check()
147  *
148  * check to see if the user needs to change their password
149  */
150 
151 static int
152 new_password_check(pw_uid, shpwd, flags)
153 	uid_t		pw_uid;
154 	struct 	spwd 	*shpwd;
155 	int 		flags;
156 {
157 	time_t	now  = DAY_NOW;
158 
159 	/*
160 	 * We want to make sure that we change the password only if
161 	 * passwords are required for the system, the user does not
162 	 * have a password, AND the user's NULL password can be changed
163 	 * according to its password aging information
164 	 */
165 
166 	if ((flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) {
167 		if (shpwd->sp_pwdp[0] == '\0') {
168 			if ((pw_uid != 0) &&
169 				((shpwd->sp_max == -1) ||
170 				((time_t)shpwd->sp_lstchg > now) ||
171 				((now >= (time_t)(shpwd->sp_lstchg +
172 							shpwd->sp_min)) &&
173 				(shpwd->sp_max >= shpwd->sp_min)))) {
174 					return (PAM_NEW_AUTHTOK_REQD);
175 			}
176 		}
177 	}
178 	return (PAM_SUCCESS);
179 }
180 
181 /*
182  * perform_passwd_aging_check
183  *		- Check for password exipration.
184  */
185 static	int
186 perform_passwd_aging_check(
187 	pam_handle_t *pamh,
188 	struct 	spwd 	*shpwd,
189 	int	flags)
190 {
191 	time_t 	now = DAY_NOW;
192 	int	idledays = -1;
193 	char	*ptr;
194 	char	messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];
195 
196 
197 	if (defopen(LOGINADMIN) == 0) {
198 		if ((ptr = defread("IDLEWEEKS=")) != NULL)
199 			idledays = 7 * atoi(ptr);
200 		(void) defopen(NULL);
201 	}
202 
203 	/*
204 	 * if (sp_lstchg == 0), the administrator has forced the
205 	 * user to change his/her passwd
206 	 */
207 	if (shpwd->sp_lstchg == 0)
208 		return (PAM_NEW_AUTHTOK_REQD);
209 
210 	/* If password aging is disabled (or min>max), all is well */
211 	if (shpwd->sp_max < 0 || shpwd->sp_max < shpwd->sp_min)
212 		return (PAM_SUCCESS);
213 
214 	/* Password aging is enabled. See if the password has aged */
215 	if (now < (time_t)(shpwd->sp_lstchg + shpwd->sp_max))
216 		return (PAM_SUCCESS);
217 
218 	/* Password has aged. Has it aged more than idledays ? */
219 	if (idledays < 0)			/* IDLEWEEKS not configured */
220 		return (PAM_NEW_AUTHTOK_REQD);
221 
222 	/* idledays is configured */
223 	if (idledays > 0 && (now < (time_t)(shpwd->sp_lstchg + idledays)))
224 		return (PAM_NEW_AUTHTOK_REQD);
225 
226 	/* password has aged more that allowed for by IDLEWEEKS */
227 	if (!(flags & PAM_SILENT)) {
228 		(void) strlcpy(messages[0], dgettext(TEXT_DOMAIN,
229 		    "Your password has been expired for too long."),
230 		    sizeof (messages[0]));
231 		(void) strlcpy(messages[1], dgettext(TEXT_DOMAIN,
232 		    "Please contact the system administrator."),
233 		    sizeof (messages[0]));
234 		(void) __pam_display_msg(pamh, PAM_ERROR_MSG, 2, messages,
235 		    NULL);
236 	}
237 	return (PAM_AUTHTOK_EXPIRED);
238 }
239 
240 /*
241  * warn_user_passwd_will_expire	- warn the user when the password will
242  *					  expire.
243  */
244 
245 static void
246 warn_user_passwd_will_expire(
247 	pam_handle_t *pamh,
248 	struct 	spwd shpwd)
249 {
250 	time_t 	now	= DAY_NOW;
251 	char	messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];
252 	time_t	days;
253 
254 
255 	if ((shpwd.sp_warn > 0) && (shpwd.sp_max > 0) &&
256 	    (now + shpwd.sp_warn) >= (time_t)(shpwd.sp_lstchg + shpwd.sp_max)) {
257 		days = (time_t)(shpwd.sp_lstchg + shpwd.sp_max) - now;
258 		if (days <= 0)
259 			(void) snprintf(messages[0],
260 				sizeof (messages[0]),
261 				dgettext(TEXT_DOMAIN,
262 				"Your password will expire within 24 hours."));
263 		else if (days == 1)
264 			(void) snprintf(messages[0],
265 				sizeof (messages[0]),
266 				dgettext(TEXT_DOMAIN,
267 				"Your password will expire in 1 day."));
268 		else
269 			(void) snprintf(messages[0],
270 				sizeof (messages[0]),
271 				dgettext(TEXT_DOMAIN,
272 				"Your password will expire in %d days."),
273 				(int)days);
274 
275 		(void) __pam_display_msg(pamh, PAM_TEXT_INFO, 1, messages,
276 		    NULL);
277 	}
278 }
279 
280 /*
281  * pam_sm_acct_mgmt	- 	main account managment routine.
282  *			  Returns: module error or specific error on failure
283  */
284 
285 int
286 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, const char **argv)
287 {
288 	uid_t			pw_uid;
289 	char			*repository_name = NULL;
290 	char    		*user;
291 	attrlist		attr_pw[3];
292 	attrlist		attr_spw[7];
293 	pwu_repository_t	*pwu_rep = PWU_DEFAULT_REP;
294 	pwu_repository_t	*auth_rep = NULL;
295 	int 			error = PAM_ACCT_EXPIRED;
296 	int			result;
297 	int			i;
298 	int			debug = 0;
299 	int			server_policy = 0;
300 	unix_authtok_data	*status;
301 	struct 	spwd		shpwd = {NULL, NULL,
302 					-1, -1, -1, -1, -1, -1, 0};
303 
304 	for (i = 0; i < argc; i++) {
305 		if (strcasecmp(argv[i], "debug") == 0)
306 			debug = 1;
307 		else if (strcasecmp(argv[i], "server_policy") == 0)
308 			server_policy = 1;
309 		else if (strcasecmp(argv[i], "nowarn") == 0) {
310 			flags = flags | PAM_SILENT;
311 		} else {
312 			syslog(LOG_ERR,
313 				"ACCOUNT:pam_sm_acct_mgmt: illegal option %s",
314 				argv[i]);
315 		}
316 	}
317 
318 	if (debug)
319 		syslog(LOG_AUTH | LOG_DEBUG,
320 		    "pam_unix_account: entering pam_sm_acct_mgmt()");
321 
322 	if ((error = pam_get_item(pamh, PAM_USER, (void **)&user))
323 							!= PAM_SUCCESS)
324 		goto out;
325 
326 	if (user == NULL) {
327 		error = PAM_USER_UNKNOWN;
328 		goto out;
329 	} else
330 		shpwd.sp_namp = user;
331 
332 	if ((error = pam_get_item(pamh, PAM_REPOSITORY, (void **)&auth_rep))
333 							!= PAM_SUCCESS)
334 		goto out;
335 
336 	if (auth_rep == NULL) {
337 		pwu_rep = PWU_DEFAULT_REP;
338 	} else {
339 		if ((pwu_rep = calloc(1, sizeof (*pwu_rep))) == NULL) {
340 			error = PAM_BUF_ERR;
341 			goto out;
342 		}
343 		pwu_rep->type = auth_rep->type;
344 		pwu_rep->scope = auth_rep->scope;
345 		pwu_rep->scope_len = auth_rep->scope_len;
346 	}
347 
348 	/*
349 	 * First get the password information
350 	 */
351 	attr_pw[0].type =  ATTR_REP_NAME;	attr_pw[0].next = &attr_pw[1];
352 	attr_pw[1].type =  ATTR_UID;		attr_pw[1].next = &attr_pw[2];
353 	attr_pw[2].type =  ATTR_PASSWD;		attr_pw[2].next = NULL;
354 	result = __get_authtoken_attr(user, pwu_rep, attr_pw);
355 
356 	if (result == PWU_NOT_FOUND) {
357 		error = PAM_USER_UNKNOWN;
358 		goto out;
359 	} else if (result == PWU_DENIED) {
360 		error = PAM_PERM_DENIED;
361 		goto out;
362 	} else if (result == PWU_NOMEM) {
363 		error = PAM_BUF_ERR;
364 		goto out;
365 	} else if (result != PWU_SUCCESS) {
366 		error = PAM_SERVICE_ERR;
367 		goto out;
368 	} else {
369 		repository_name = attr_pw[0].data.val_s;
370 		pw_uid = attr_pw[1].data.val_i;
371 		shpwd.sp_pwdp = attr_pw[2].data.val_s;
372 	}
373 
374 	/*
375 	 * if repository is not files|nis|nisplus, and
376 	 * user wants server_policy, we don't care
377 	 * about aging and hence return PAM_IGNORE
378 	 */
379 	if (server_policy &&
380 	    strcmp(repository_name, "files") != 0 &&
381 	    strcmp(repository_name, "nis") != 0 &&
382 	    strcmp(repository_name, "nisplus") != 0) {
383 		error = PAM_IGNORE;
384 		goto out;
385 	}
386 
387 	/*
388 	 * Now get the aging information
389 	 */
390 	attr_spw[0].type =  ATTR_LSTCHG;	attr_spw[0].next = &attr_spw[1];
391 	attr_spw[1].type =  ATTR_MIN;		attr_spw[1].next = &attr_spw[2];
392 	attr_spw[2].type =  ATTR_MAX;		attr_spw[2].next = &attr_spw[3];
393 	attr_spw[3].type =  ATTR_WARN;		attr_spw[3].next = &attr_spw[4];
394 	attr_spw[4].type =  ATTR_INACT;		attr_spw[4].next = &attr_spw[5];
395 	attr_spw[5].type =  ATTR_EXPIRE;	attr_spw[5].next = &attr_spw[6];
396 	attr_spw[6].type =  ATTR_FLAG;		attr_spw[6].next = NULL;
397 
398 	result = __get_authtoken_attr(user, pwu_rep, attr_spw);
399 	if (result == PWU_SUCCESS) {
400 		shpwd.sp_lstchg = attr_spw[0].data.val_i;
401 		shpwd.sp_min = attr_spw[1].data.val_i;
402 		shpwd.sp_max = attr_spw[2].data.val_i;
403 		shpwd.sp_warn = attr_spw[3].data.val_i;
404 		shpwd.sp_inact = attr_spw[4].data.val_i;
405 		shpwd.sp_expire = attr_spw[5].data.val_i;
406 		shpwd.sp_flag = attr_spw[6].data.val_i;
407 	}
408 
409 	if (debug) {
410 		char *pw = "Unix PW";
411 
412 		if (shpwd.sp_pwdp == NULL)
413 			pw = "NULL";
414 		else if (strncmp(shpwd.sp_pwdp, LOCKSTRING,
415 		    sizeof (LOCKSTRING) - 1) == 0)
416 			pw = LOCKSTRING;
417 		else if (strcmp(shpwd.sp_pwdp, NO_PW) == 0)
418 			pw = NO_PW;
419 
420 		if (result ==  PWU_DENIED) {
421 			syslog(LOG_AUTH | LOG_DEBUG,
422 				"pam_unix_account: %s: permission denied "
423 				"to access password aging information. "
424 				"Using defaults.", user);
425 		}
426 
427 		syslog(LOG_AUTH | LOG_DEBUG,
428 		    "%s Policy:Unix, pw=%s, lstchg=%d, min=%d, max=%d, "
429 		    "warn=%d, inact=%d, expire=%d",
430 		    user, pw, shpwd.sp_lstchg, shpwd.sp_min, shpwd.sp_max,
431 		    shpwd.sp_warn, shpwd.sp_inact, shpwd.sp_expire);
432 	}
433 
434 	if (pwu_rep != PWU_DEFAULT_REP) {
435 		free(pwu_rep);
436 		pwu_rep = PWU_DEFAULT_REP;
437 	}
438 
439 	if (result == PWU_NOT_FOUND) {
440 		error = PAM_USER_UNKNOWN;
441 		goto out;
442 	} else if (result == PWU_NOMEM) {
443 		error = PAM_BUF_ERR;
444 		goto out;
445 	} else if (result != PWU_SUCCESS && result != PWU_DENIED) {
446 		error = PAM_SERVICE_ERR;
447 		goto out;
448 	}
449 
450 	/*
451 	 * Check for locked account
452 	 */
453 	if (shpwd.sp_pwdp != NULL &&
454 	    strncmp(shpwd.sp_pwdp, LOCKSTRING, sizeof (LOCKSTRING) - 1) == 0) {
455 		char *service;
456 		char *rhost = NULL;
457 
458 		(void) pam_get_item(pamh, PAM_SERVICE, (void **)&service);
459 		(void) pam_get_item(pamh, PAM_RHOST, (void **)&rhost);
460 		__pam_log(LOG_AUTH | LOG_NOTICE,
461 		    "pam_unix_account: %s attempting to validate locked "
462 		    "account %s from %s",
463 		    service, user,
464 		    (rhost != NULL && *rhost != '\0') ? rhost : "local host");
465 		error = PAM_PERM_DENIED;
466 		goto out;
467 	}
468 
469 	/*
470 	 * Check for account expiration
471 	 */
472 	if (shpwd.sp_expire > 0 &&
473 	    (time_t)shpwd.sp_expire < DAY_NOW) {
474 		error = PAM_ACCT_EXPIRED;
475 		goto out;
476 	}
477 
478 	/*
479 	 * Check for excessive login account inactivity
480 	 */
481 	if (check_for_login_inactivity(pw_uid, &shpwd)) {
482 		error = PAM_PERM_DENIED;
483 		goto out;
484 	}
485 
486 	/*
487 	 * Check to see if the user needs to change their password
488 	 */
489 	if (error = new_password_check(pw_uid, &shpwd, flags)) {
490 		goto out;
491 	}
492 
493 	/*
494 	 * Check to make sure password aging information is okay
495 	 */
496 	if ((error = perform_passwd_aging_check(pamh, &shpwd, flags))
497 							!= PAM_SUCCESS) {
498 		goto out;
499 	}
500 
501 	/*
502 	 * Finally, warn the user if their password is about to expire.
503 	 */
504 	if (!(flags & PAM_SILENT)) {
505 		warn_user_passwd_will_expire(pamh, shpwd);
506 	}
507 
508 	/*
509 	 * All done, return Success
510 	 */
511 	error = PAM_SUCCESS;
512 
513 out:
514 
515 	{
516 		int pam_res;
517 		unix_authtok_data *authtok_data;
518 
519 		if (debug) {
520 			syslog(LOG_AUTH | LOG_DEBUG,
521 				"pam_unix_account: %s: %s",
522 				(user == NULL)?"NULL":user,
523 				pam_strerror(pamh, error));
524 		}
525 
526 		if (repository_name)
527 			free(repository_name);
528 		if (pwu_rep != PWU_DEFAULT_REP)
529 			free(pwu_rep);
530 		if (shpwd.sp_pwdp) {
531 			(void) memset(shpwd.sp_pwdp, 0, strlen(shpwd.sp_pwdp));
532 			free(shpwd.sp_pwdp);
533 		}
534 
535 		/* store the password aging status in the pam handle */
536 		pam_res = pam_get_data(
537 			pamh, UNIX_AUTHTOK_DATA, (const void **)&authtok_data);
538 
539 		if ((status = (unix_authtok_data *)calloc
540 			(1, sizeof (unix_authtok_data))) == NULL) {
541 			return (PAM_BUF_ERR);
542 		}
543 
544 		if (pam_res == PAM_SUCCESS)
545 			(void) memcpy(status, authtok_data,
546 				sizeof (unix_authtok_data));
547 
548 		status->age_status = error;
549 		if (pam_set_data(pamh, UNIX_AUTHTOK_DATA, status, unix_cleanup)
550 							!= PAM_SUCCESS) {
551 			free(status);
552 			return (PAM_SERVICE_ERR);
553 		}
554 	}
555 
556 	return (error);
557 }
558