xref: /illumos-gate/usr/src/lib/pam_modules/unix_account/unix_acct.c (revision a38ddfee9c8c6b6c5a2947ff52fd2338362a4444)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 
27 #include <sys/types.h>
28 #include <sys/wait.h>
29 #include <sys/stat.h>
30 #include <fcntl.h>
31 #include <stdlib.h>
32 #include <security/pam_appl.h>
33 #include <security/pam_modules.h>
34 #include <security/pam_impl.h>
35 #include <syslog.h>
36 #include <pwd.h>
37 #include <shadow.h>
38 #include <lastlog.h>
39 #include <ctype.h>
40 #include <unistd.h>
41 #include <stdlib.h>
42 #include <stdio.h>
43 #include <libintl.h>
44 #include <signal.h>
45 #include <thread.h>
46 #include <synch.h>
47 #include <errno.h>
48 #include <time.h>
49 #include <string.h>
50 #include <crypt.h>
51 #include <assert.h>
52 #include <deflt.h>
53 #include <libintl.h>
54 #include <passwdutil.h>
55 
56 #define	LASTLOG		"/var/adm/lastlog"
57 #define	LOGINADMIN	"/etc/default/login"
58 #define	UNIX_AUTH_DATA		"SUNW-UNIX-AUTH-DATA"
59 #define	UNIX_AUTHTOK_DATA	"SUNW-UNIX-AUTHTOK-DATA"
60 
61 /*
62  * Function Declarations
63  */
64 extern int		defopen(char *);
65 extern char		*defread(char *);
66 extern void		setusershell();
67 extern int		_nfssys(int, void *);
68 
69 typedef struct _unix_authtok_data_ {
70 	int age_status;
71 }unix_authtok_data;
72 
73 /*ARGSUSED*/
74 static void
75 unix_cleanup(
76 	pam_handle_t *pamh,
77 	void *data,
78 	int pam_status)
79 {
80 	free((unix_authtok_data *)data);
81 }
82 
83 /*
84  * check_for_login_inactivity	- Check for login inactivity
85  *
86  */
87 
88 static int
89 check_for_login_inactivity(
90 	uid_t		pw_uid,
91 	struct 	spwd 	*shpwd)
92 {
93 	int		fdl;
94 	struct lastlog	ll;
95 	int		retval;
96 	offset_t	offset;
97 
98 	offset = (offset_t)pw_uid * (offset_t)sizeof (struct lastlog);
99 
100 	if ((fdl = open(LASTLOG, O_RDWR|O_CREAT, 0444)) >= 0) {
101 		/*
102 		 * Read the last login (ll) time
103 		 */
104 		if (llseek(fdl, offset, SEEK_SET) != offset) {
105 			__pam_log(LOG_AUTH | LOG_ERR,
106 			    "pam_unix_acct: pam_sm_acct_mgmt: "
107 			    "can't obtain last login info on uid %d "
108 			    "(uid too large)", pw_uid);
109 			return (0);
110 		}
111 
112 		retval = read(fdl, (char *)&ll, sizeof (ll));
113 
114 		/* Check for login inactivity */
115 
116 		if ((shpwd->sp_inact > 0) && (retval == sizeof (ll)) &&
117 		    ll.ll_time) {
118 			/*
119 			 * account inactive too long.
120 			 * and no update password set
121 			 * and no last pwd change date in shadow file
122 			 * and last pwd change more than inactive time
123 			 * then account inactive too long and no access.
124 			 */
125 			if (((time_t)((ll.ll_time / DAY) + shpwd->sp_inact)
126 			    < DAY_NOW) &&
127 			    (shpwd->sp_lstchg != 0) &&
128 			    (shpwd->sp_lstchg != -1) &&
129 			    ((shpwd->sp_lstchg + shpwd->sp_inact) < DAY_NOW)) {
130 				/*
131 				 * Account inactive for too long
132 				 */
133 				(void) close(fdl);
134 				return (1);
135 			}
136 		}
137 
138 		(void) close(fdl);
139 	}
140 	return (0);
141 }
142 
143 /*
144  * new_password_check()
145  *
146  * check to see if the user needs to change their password
147  */
148 
149 static int
150 new_password_check(shpwd, flags)
151 	struct 	spwd 	*shpwd;
152 	int 		flags;
153 {
154 	time_t	now  = DAY_NOW;
155 
156 	/*
157 	 * We want to make sure that we change the password only if
158 	 * passwords are required for the system, the user does not
159 	 * have a password, AND the user's NULL password can be changed
160 	 * according to its password aging information
161 	 */
162 
163 	if ((flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) {
164 		if (shpwd->sp_pwdp[0] == '\0') {
165 			if (((shpwd->sp_max == -1) ||
166 				((time_t)shpwd->sp_lstchg > now) ||
167 				((now >= (time_t)(shpwd->sp_lstchg +
168 							shpwd->sp_min)) &&
169 				(shpwd->sp_max >= shpwd->sp_min)))) {
170 					return (PAM_NEW_AUTHTOK_REQD);
171 			}
172 		}
173 	}
174 	return (PAM_SUCCESS);
175 }
176 
177 /*
178  * perform_passwd_aging_check
179  *		- Check for password exipration.
180  */
181 static	int
182 perform_passwd_aging_check(
183 	pam_handle_t *pamh,
184 	struct 	spwd 	*shpwd,
185 	int	flags)
186 {
187 	time_t 	now = DAY_NOW;
188 	int	idledays = -1;
189 	char	*ptr;
190 	char	messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];
191 
192 
193 	if (defopen(LOGINADMIN) == 0) {
194 		if ((ptr = defread("IDLEWEEKS=")) != NULL)
195 			idledays = 7 * atoi(ptr);
196 		(void) defopen(NULL);
197 	}
198 
199 	/*
200 	 * if (sp_lstchg == 0), the administrator has forced the
201 	 * user to change his/her passwd
202 	 */
203 	if (shpwd->sp_lstchg == 0)
204 		return (PAM_NEW_AUTHTOK_REQD);
205 
206 	/* If password aging is disabled (or min>max), all is well */
207 	if (shpwd->sp_max < 0 || shpwd->sp_max < shpwd->sp_min)
208 		return (PAM_SUCCESS);
209 
210 	/* Password aging is enabled. See if the password has aged */
211 	if (now < (time_t)(shpwd->sp_lstchg + shpwd->sp_max))
212 		return (PAM_SUCCESS);
213 
214 	/* Password has aged. Has it aged more than idledays ? */
215 	if (idledays < 0)			/* IDLEWEEKS not configured */
216 		return (PAM_NEW_AUTHTOK_REQD);
217 
218 	/* idledays is configured */
219 	if (idledays > 0 && (now < (time_t)(shpwd->sp_lstchg + idledays)))
220 		return (PAM_NEW_AUTHTOK_REQD);
221 
222 	/* password has aged more that allowed for by IDLEWEEKS */
223 	if (!(flags & PAM_SILENT)) {
224 		(void) strlcpy(messages[0], dgettext(TEXT_DOMAIN,
225 		    "Your password has been expired for too long."),
226 		    sizeof (messages[0]));
227 		(void) strlcpy(messages[1], dgettext(TEXT_DOMAIN,
228 		    "Please contact the system administrator."),
229 		    sizeof (messages[0]));
230 		(void) __pam_display_msg(pamh, PAM_ERROR_MSG, 2, messages,
231 		    NULL);
232 	}
233 	return (PAM_AUTHTOK_EXPIRED);
234 }
235 
236 /*
237  * warn_user_passwd_will_expire	- warn the user when the password will
238  *					  expire.
239  */
240 
241 static void
242 warn_user_passwd_will_expire(
243 	pam_handle_t *pamh,
244 	struct 	spwd shpwd)
245 {
246 	time_t 	now	= DAY_NOW;
247 	char	messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];
248 	time_t	days;
249 
250 
251 	if ((shpwd.sp_warn > 0) && (shpwd.sp_max > 0) &&
252 	    (now + shpwd.sp_warn) >= (time_t)(shpwd.sp_lstchg + shpwd.sp_max)) {
253 		days = (time_t)(shpwd.sp_lstchg + shpwd.sp_max) - now;
254 		if (days <= 0)
255 			(void) snprintf(messages[0],
256 			    sizeof (messages[0]),
257 			    dgettext(TEXT_DOMAIN,
258 			    "Your password will expire within 24 hours."));
259 		else if (days == 1)
260 			(void) snprintf(messages[0],
261 			    sizeof (messages[0]),
262 			    dgettext(TEXT_DOMAIN,
263 			    "Your password will expire in 1 day."));
264 		else
265 			(void) snprintf(messages[0],
266 			    sizeof (messages[0]),
267 			    dgettext(TEXT_DOMAIN,
268 			    "Your password will expire in %d days."),
269 			    (int)days);
270 
271 		(void) __pam_display_msg(pamh, PAM_TEXT_INFO, 1, messages,
272 		    NULL);
273 	}
274 }
275 
276 /*
277  * pam_sm_acct_mgmt	- 	main account managment routine.
278  *			  Returns: module error or specific error on failure
279  */
280 
281 int
282 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags, int argc, const char **argv)
283 {
284 	uid_t			pw_uid;
285 	char			*repository_name = NULL;
286 	char    		*user;
287 	attrlist		attr_pw[3];
288 	attrlist		attr_spw[7];
289 	pwu_repository_t	*pwu_rep = PWU_DEFAULT_REP;
290 	pwu_repository_t	*auth_rep = NULL;
291 	int 			error = PAM_ACCT_EXPIRED;
292 	int			result;
293 	int			i;
294 	int			debug = 0;
295 	int			server_policy = 0;
296 	unix_authtok_data	*status;
297 	struct 	spwd		shpwd = {NULL, NULL,
298 					-1, -1, -1, -1, -1, -1, 0};
299 
300 	for (i = 0; i < argc; i++) {
301 		if (strcasecmp(argv[i], "debug") == 0)
302 			debug = 1;
303 		else if (strcasecmp(argv[i], "server_policy") == 0)
304 			server_policy = 1;
305 		else if (strcasecmp(argv[i], "nowarn") == 0) {
306 			flags = flags | PAM_SILENT;
307 		} else {
308 			__pam_log(LOG_AUTH | LOG_ERR,
309 			    "ACCOUNT:pam_sm_acct_mgmt: illegal option %s",
310 			    argv[i]);
311 		}
312 	}
313 
314 	if (debug)
315 		__pam_log(LOG_AUTH | LOG_DEBUG,
316 		    "pam_unix_account: entering pam_sm_acct_mgmt()");
317 
318 	if ((error = pam_get_item(pamh, PAM_USER, (void **)&user))
319 	    != PAM_SUCCESS)
320 		goto out;
321 
322 	if (user == NULL) {
323 		error = PAM_USER_UNKNOWN;
324 		goto out;
325 	} else
326 		shpwd.sp_namp = user;
327 
328 	if ((error = pam_get_item(pamh, PAM_REPOSITORY, (void **)&auth_rep))
329 	    != PAM_SUCCESS)
330 		goto out;
331 
332 	if (auth_rep == NULL) {
333 		pwu_rep = PWU_DEFAULT_REP;
334 	} else {
335 		if ((pwu_rep = calloc(1, sizeof (*pwu_rep))) == NULL) {
336 			error = PAM_BUF_ERR;
337 			goto out;
338 		}
339 		pwu_rep->type = auth_rep->type;
340 		pwu_rep->scope = auth_rep->scope;
341 		pwu_rep->scope_len = auth_rep->scope_len;
342 	}
343 
344 	/*
345 	 * First get the password information
346 	 */
347 	attr_pw[0].type =  ATTR_REP_NAME;	attr_pw[0].next = &attr_pw[1];
348 	attr_pw[1].type =  ATTR_UID;		attr_pw[1].next = &attr_pw[2];
349 	attr_pw[2].type =  ATTR_PASSWD;		attr_pw[2].next = NULL;
350 	result = __get_authtoken_attr(user, pwu_rep, attr_pw);
351 
352 	if (result == PWU_NOT_FOUND) {
353 		error = PAM_USER_UNKNOWN;
354 		goto out;
355 	} else if (result == PWU_DENIED) {
356 		error = PAM_PERM_DENIED;
357 		goto out;
358 	} else if (result == PWU_NOMEM) {
359 		error = PAM_BUF_ERR;
360 		goto out;
361 	} else if (result != PWU_SUCCESS) {
362 		error = PAM_SERVICE_ERR;
363 		goto out;
364 	} else {
365 		repository_name = attr_pw[0].data.val_s;
366 		pw_uid = attr_pw[1].data.val_i;
367 		shpwd.sp_pwdp = attr_pw[2].data.val_s;
368 	}
369 
370 	/*
371 	 * if repository is not files|nis|nisplus, and
372 	 * user wants server_policy, we don't care
373 	 * about aging and hence return PAM_IGNORE
374 	 */
375 	if (server_policy &&
376 	    strcmp(repository_name, "files") != 0 &&
377 	    strcmp(repository_name, "nis") != 0 &&
378 	    strcmp(repository_name, "nisplus") != 0) {
379 		error = PAM_IGNORE;
380 		goto out;
381 	}
382 
383 	/*
384 	 * Now get the aging information
385 	 */
386 	attr_spw[0].type =  ATTR_LSTCHG;	attr_spw[0].next = &attr_spw[1];
387 	attr_spw[1].type =  ATTR_MIN;		attr_spw[1].next = &attr_spw[2];
388 	attr_spw[2].type =  ATTR_MAX;		attr_spw[2].next = &attr_spw[3];
389 	attr_spw[3].type =  ATTR_WARN;		attr_spw[3].next = &attr_spw[4];
390 	attr_spw[4].type =  ATTR_INACT;		attr_spw[4].next = &attr_spw[5];
391 	attr_spw[5].type =  ATTR_EXPIRE;	attr_spw[5].next = &attr_spw[6];
392 	attr_spw[6].type =  ATTR_FLAG;		attr_spw[6].next = NULL;
393 
394 	result = __get_authtoken_attr(user, pwu_rep, attr_spw);
395 	if (result == PWU_SUCCESS) {
396 		shpwd.sp_lstchg = attr_spw[0].data.val_i;
397 		shpwd.sp_min = attr_spw[1].data.val_i;
398 		shpwd.sp_max = attr_spw[2].data.val_i;
399 		shpwd.sp_warn = attr_spw[3].data.val_i;
400 		shpwd.sp_inact = attr_spw[4].data.val_i;
401 		shpwd.sp_expire = attr_spw[5].data.val_i;
402 		shpwd.sp_flag = attr_spw[6].data.val_i;
403 	}
404 
405 	if (debug) {
406 		char *pw = "Unix PW";
407 
408 		if (shpwd.sp_pwdp == NULL)
409 			pw = "NULL";
410 		else if (strncmp(shpwd.sp_pwdp, LOCKSTRING,
411 		    sizeof (LOCKSTRING) - 1) == 0)
412 			pw = LOCKSTRING;
413 		else if (strcmp(shpwd.sp_pwdp, NOPWDRTR) == 0)
414 			pw = NOPWDRTR;
415 
416 		if (result ==  PWU_DENIED) {
417 			__pam_log(LOG_AUTH | LOG_DEBUG,
418 			    "pam_unix_account: %s: permission denied "
419 			    "to access password aging information. "
420 			    "Using defaults.", user);
421 		}
422 
423 		__pam_log(LOG_AUTH | LOG_DEBUG,
424 		    "%s Policy:Unix, pw=%s, lstchg=%d, min=%d, max=%d, "
425 		    "warn=%d, inact=%d, expire=%d",
426 		    user, pw, shpwd.sp_lstchg, shpwd.sp_min, shpwd.sp_max,
427 		    shpwd.sp_warn, shpwd.sp_inact, shpwd.sp_expire);
428 	}
429 
430 	if (pwu_rep != PWU_DEFAULT_REP) {
431 		free(pwu_rep);
432 		pwu_rep = PWU_DEFAULT_REP;
433 	}
434 
435 	if (result == PWU_NOT_FOUND) {
436 		error = PAM_USER_UNKNOWN;
437 		goto out;
438 	} else if (result == PWU_NOMEM) {
439 		error = PAM_BUF_ERR;
440 		goto out;
441 	} else if (result != PWU_SUCCESS && result != PWU_DENIED) {
442 		error = PAM_SERVICE_ERR;
443 		goto out;
444 	}
445 
446 	/*
447 	 * Check for locked account
448 	 */
449 	if (shpwd.sp_pwdp != NULL &&
450 	    strncmp(shpwd.sp_pwdp, LOCKSTRING, sizeof (LOCKSTRING) - 1) == 0) {
451 		char *service;
452 		char *rhost = NULL;
453 
454 		(void) pam_get_item(pamh, PAM_SERVICE, (void **)&service);
455 		(void) pam_get_item(pamh, PAM_RHOST, (void **)&rhost);
456 		__pam_log(LOG_AUTH | LOG_NOTICE,
457 		    "pam_unix_account: %s attempting to validate locked "
458 		    "account %s from %s",
459 		    service, user,
460 		    (rhost != NULL && *rhost != '\0') ? rhost : "local host");
461 		error = PAM_PERM_DENIED;
462 		goto out;
463 	}
464 
465 	/*
466 	 * Check for NULL password and, if so, see if such is allowed
467 	 */
468 	if (shpwd.sp_pwdp[0] == '\0' &&
469 	    (flags & PAM_DISALLOW_NULL_AUTHTOK) != 0) {
470 		char *service;
471 		char *rhost = NULL;
472 
473 		(void) pam_get_item(pamh, PAM_SERVICE, (void **)&service);
474 		(void) pam_get_item(pamh, PAM_RHOST, (void **)&rhost);
475 
476 		__pam_log(LOG_AUTH | LOG_NOTICE,
477 		    "pam_unix_account: %s: empty password not allowed for "
478 		    "account %s from %s", service, user,
479 		    (rhost != NULL && *rhost != '\0') ? rhost : "local host");
480 		error = PAM_PERM_DENIED;
481 		goto out;
482 	}
483 
484 	/*
485 	 * Check for account expiration
486 	 */
487 	if (shpwd.sp_expire > 0 &&
488 	    (time_t)shpwd.sp_expire < DAY_NOW) {
489 		error = PAM_ACCT_EXPIRED;
490 		goto out;
491 	}
492 
493 	/*
494 	 * Check for excessive login account inactivity
495 	 */
496 	if (check_for_login_inactivity(pw_uid, &shpwd)) {
497 		error = PAM_PERM_DENIED;
498 		goto out;
499 	}
500 
501 	/*
502 	 * Check to see if the user needs to change their password
503 	 */
504 	if (error = new_password_check(&shpwd, flags)) {
505 		goto out;
506 	}
507 
508 	/*
509 	 * Check to make sure password aging information is okay
510 	 */
511 	if ((error = perform_passwd_aging_check(pamh, &shpwd, flags))
512 	    != PAM_SUCCESS) {
513 		goto out;
514 	}
515 
516 	/*
517 	 * Finally, warn the user if their password is about to expire.
518 	 */
519 	if (!(flags & PAM_SILENT)) {
520 		warn_user_passwd_will_expire(pamh, shpwd);
521 	}
522 
523 	/*
524 	 * All done, return Success
525 	 */
526 	error = PAM_SUCCESS;
527 
528 out:
529 
530 	{
531 		int pam_res;
532 		unix_authtok_data *authtok_data;
533 
534 		if (debug) {
535 			__pam_log(LOG_AUTH | LOG_DEBUG,
536 			    "pam_unix_account: %s: %s",
537 			    (user == NULL)?"NULL":user,
538 			    pam_strerror(pamh, error));
539 		}
540 
541 		if (repository_name)
542 			free(repository_name);
543 		if (pwu_rep != PWU_DEFAULT_REP)
544 			free(pwu_rep);
545 		if (shpwd.sp_pwdp) {
546 			(void) memset(shpwd.sp_pwdp, 0, strlen(shpwd.sp_pwdp));
547 			free(shpwd.sp_pwdp);
548 		}
549 
550 		/* store the password aging status in the pam handle */
551 		pam_res = pam_get_data(pamh, UNIX_AUTHTOK_DATA,
552 		    (const void **)&authtok_data);
553 
554 		if ((status = (unix_authtok_data *)calloc(1,
555 		    sizeof (unix_authtok_data))) == NULL) {
556 			return (PAM_BUF_ERR);
557 		}
558 
559 		if (pam_res == PAM_SUCCESS)
560 			(void) memcpy(status, authtok_data,
561 			    sizeof (unix_authtok_data));
562 
563 		status->age_status = error;
564 		if (pam_set_data(pamh, UNIX_AUTHTOK_DATA, status, unix_cleanup)
565 		    != PAM_SUCCESS) {
566 			free(status);
567 			return (PAM_SERVICE_ERR);
568 		}
569 	}
570 
571 	return (error);
572 }
573