1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright 1998 Juniper Networks, Inc.
5 * All rights reserved.
6 * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
7 * All rights reserved.
8 *
9 * Portions of this software was developed for the FreeBSD Project by
10 * ThinkSec AS and NAI Labs, the Security Research Division of Network
11 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
12 * ("CBOSS"), as part of the DARPA CHATS research program.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * 3. The name of the author may not be used to endorse or promote
23 * products derived from this software without specific prior written
24 * permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39 #include <sys/cdefs.h>
40 #include <sys/param.h>
41 #include <sys/socket.h>
42 #include <sys/time.h>
43 #include <netinet/in.h>
44 #include <arpa/inet.h>
45
46 #include <login_cap.h>
47 #include <netdb.h>
48 #include <pwd.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <stdio.h>
52 #include <syslog.h>
53 #include <time.h>
54 #include <unistd.h>
55
56 #include <libutil.h>
57
58 #ifdef YP
59 #include <ypclnt.h>
60 #endif
61
62 #define PAM_SM_AUTH
63 #define PAM_SM_ACCOUNT
64 #define PAM_SM_PASSWORD
65
66 #include <security/pam_appl.h>
67 #include <security/pam_modules.h>
68 #include <security/pam_mod_misc.h>
69
70 #define PASSWORD_HASH "md5"
71 #define DEFAULT_WARN (2L * 7L * 86400L) /* Two weeks */
72 #define SALTSIZE 32
73
74 #define LOCKED_PREFIX "*LOCKED*"
75 #define LOCKED_PREFIX_LEN (sizeof(LOCKED_PREFIX) - 1)
76
77 static void makesalt(char [SALTSIZE + 1]);
78
79 static char password_hash[] = PASSWORD_HASH;
80
81 #define PAM_OPT_LOCAL_PASS "local_pass"
82 #define PAM_OPT_NIS_PASS "nis_pass"
83
84 /*
85 * authentication management
86 */
87 PAM_EXTERN int
pam_sm_authenticate(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)88 pam_sm_authenticate(pam_handle_t *pamh, int flags __unused,
89 int argc __unused, const char *argv[] __unused)
90 {
91 login_cap_t *lc;
92 struct passwd *pwd;
93 int retval;
94 const char *pass, *user, *realpw, *prompt;
95
96 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF)) {
97 user = getlogin();
98 } else {
99 retval = pam_get_user(pamh, &user, NULL);
100 if (retval != PAM_SUCCESS)
101 return (retval);
102 }
103 pwd = getpwnam(user);
104
105 PAM_LOG("Got user: %s", user);
106
107 if (pwd != NULL) {
108 PAM_LOG("Doing real authentication");
109 realpw = pwd->pw_passwd;
110 if (realpw[0] == '\0') {
111 if (!(flags & PAM_DISALLOW_NULL_AUTHTOK) &&
112 openpam_get_option(pamh, PAM_OPT_NULLOK))
113 return (PAM_SUCCESS);
114 PAM_LOG("Password is empty, using fake password");
115 realpw = "*";
116 }
117 lc = login_getpwclass(pwd);
118 } else {
119 PAM_LOG("Doing dummy authentication");
120 realpw = "*";
121 lc = login_getclass(NULL);
122 }
123 prompt = login_getcapstr(lc, "passwd_prompt", NULL, NULL);
124 retval = pam_get_authtok(pamh, PAM_AUTHTOK, &pass, prompt);
125 login_close(lc);
126 if (retval != PAM_SUCCESS)
127 return (retval);
128 PAM_LOG("Got password");
129 if (strnlen(pass, _PASSWORD_LEN + 1) > _PASSWORD_LEN) {
130 PAM_LOG("Password is too long, using fake password");
131 realpw = "*";
132 }
133 if (strcmp(crypt(pass, realpw), realpw) == 0)
134 return (PAM_SUCCESS);
135
136 PAM_VERBOSE_ERROR("UNIX authentication refused");
137 return (PAM_AUTH_ERR);
138 }
139
140 PAM_EXTERN int
pam_sm_setcred(pam_handle_t * pamh __unused,int flags __unused,int argc __unused,const char * argv[]__unused)141 pam_sm_setcred(pam_handle_t *pamh __unused, int flags __unused,
142 int argc __unused, const char *argv[] __unused)
143 {
144
145 return (PAM_SUCCESS);
146 }
147
148 /*
149 * account management
150 */
151 PAM_EXTERN int
pam_sm_acct_mgmt(pam_handle_t * pamh,int flags __unused,int argc __unused,const char * argv[]__unused)152 pam_sm_acct_mgmt(pam_handle_t *pamh, int flags __unused,
153 int argc __unused, const char *argv[] __unused)
154 {
155 struct addrinfo hints, *res;
156 struct passwd *pwd;
157 struct timeval tp;
158 login_cap_t *lc;
159 time_t warntime;
160 int retval;
161 const char *user;
162 const void *rhost, *tty;
163 char rhostip[MAXHOSTNAMELEN] = "";
164
165 retval = pam_get_user(pamh, &user, NULL);
166 if (retval != PAM_SUCCESS)
167 return (retval);
168
169 if (user == NULL || (pwd = getpwnam(user)) == NULL)
170 return (PAM_SERVICE_ERR);
171
172 PAM_LOG("Got user: %s", user);
173
174 retval = pam_get_item(pamh, PAM_RHOST, &rhost);
175 if (retval != PAM_SUCCESS)
176 return (retval);
177
178 retval = pam_get_item(pamh, PAM_TTY, &tty);
179 if (retval != PAM_SUCCESS)
180 return (retval);
181
182 if (*pwd->pw_passwd == '\0' &&
183 (flags & PAM_DISALLOW_NULL_AUTHTOK) != 0)
184 return (PAM_NEW_AUTHTOK_REQD);
185
186 if (strncmp(pwd->pw_passwd, LOCKED_PREFIX, LOCKED_PREFIX_LEN) == 0)
187 return (PAM_AUTH_ERR);
188
189 lc = login_getpwclass(pwd);
190 if (lc == NULL) {
191 PAM_LOG("Unable to get login class for user %s", user);
192 return (PAM_SERVICE_ERR);
193 }
194
195 PAM_LOG("Got login_cap");
196
197 if (pwd->pw_change || pwd->pw_expire)
198 gettimeofday(&tp, NULL);
199
200 /*
201 * Check pw_expire before pw_change - no point in letting the
202 * user change the password on an expired account.
203 */
204
205 if (pwd->pw_expire) {
206 warntime = login_getcaptime(lc, "warnexpire",
207 DEFAULT_WARN, DEFAULT_WARN);
208 if (tp.tv_sec >= pwd->pw_expire) {
209 login_close(lc);
210 return (PAM_ACCT_EXPIRED);
211 } else if (pwd->pw_expire - tp.tv_sec < warntime &&
212 (flags & PAM_SILENT) == 0) {
213 pam_error(pamh, "Warning: your account expires on %s",
214 ctime(&pwd->pw_expire));
215 }
216 }
217
218 retval = PAM_SUCCESS;
219 if (pwd->pw_change) {
220 warntime = login_getcaptime(lc, "warnpassword",
221 DEFAULT_WARN, DEFAULT_WARN);
222 if (tp.tv_sec >= pwd->pw_change) {
223 retval = PAM_NEW_AUTHTOK_REQD;
224 } else if (pwd->pw_change - tp.tv_sec < warntime &&
225 (flags & PAM_SILENT) == 0) {
226 pam_error(pamh, "Warning: your password expires on %s",
227 ctime(&pwd->pw_change));
228 }
229 }
230
231 /*
232 * From here on, we must leave retval untouched (unless we
233 * know we're going to fail), because we need to remember
234 * whether we're supposed to return PAM_SUCCESS or
235 * PAM_NEW_AUTHTOK_REQD.
236 */
237
238 if (rhost && *(const char *)rhost != '\0') {
239 memset(&hints, 0, sizeof(hints));
240 hints.ai_family = AF_UNSPEC;
241 if (getaddrinfo(rhost, NULL, &hints, &res) == 0) {
242 getnameinfo(res->ai_addr, res->ai_addrlen,
243 rhostip, sizeof(rhostip), NULL, 0,
244 NI_NUMERICHOST);
245 }
246 if (res != NULL)
247 freeaddrinfo(res);
248 }
249
250 /*
251 * Check host / tty / time-of-day restrictions
252 */
253
254 if (!auth_hostok(lc, rhost, rhostip) ||
255 !auth_ttyok(lc, tty) ||
256 !auth_timeok(lc, time(NULL)))
257 retval = PAM_AUTH_ERR;
258
259 login_close(lc);
260
261 return (retval);
262 }
263
264 /*
265 * password management
266 *
267 * standard Unix and NIS password changing
268 */
269 PAM_EXTERN int
pam_sm_chauthtok(pam_handle_t * pamh,int flags,int argc __unused,const char * argv[]__unused)270 pam_sm_chauthtok(pam_handle_t *pamh, int flags,
271 int argc __unused, const char *argv[] __unused)
272 {
273 #ifdef YP
274 struct ypclnt *ypclnt;
275 const void *yp_domain, *yp_server;
276 #endif
277 char salt[SALTSIZE + 1];
278 login_cap_t *lc;
279 struct passwd *pwd, *old_pwd;
280 const char *user, *old_pass, *new_pass;
281 char *encrypted;
282 time_t passwordtime;
283 int pfd, tfd, retval;
284
285 if (openpam_get_option(pamh, PAM_OPT_AUTH_AS_SELF))
286 user = getlogin();
287 else {
288 retval = pam_get_user(pamh, &user, NULL);
289 if (retval != PAM_SUCCESS)
290 return (retval);
291 }
292 pwd = getpwnam(user);
293
294 if (pwd == NULL)
295 return (PAM_AUTHTOK_RECOVERY_ERR);
296
297 PAM_LOG("Got user: %s", user);
298
299 if (flags & PAM_PRELIM_CHECK) {
300
301 PAM_LOG("PRELIM round");
302
303 if (getuid() == 0 &&
304 (pwd->pw_fields & _PWF_SOURCE) == _PWF_FILES)
305 /* root doesn't need the old password */
306 return (pam_set_item(pamh, PAM_OLDAUTHTOK, ""));
307 #ifdef YP
308 if (getuid() == 0 &&
309 (pwd->pw_fields & _PWF_SOURCE) == _PWF_NIS) {
310
311 yp_domain = yp_server = NULL;
312 (void)pam_get_data(pamh, "yp_domain", &yp_domain);
313 (void)pam_get_data(pamh, "yp_server", &yp_server);
314
315 ypclnt = ypclnt_new(yp_domain, "passwd.byname", yp_server);
316 if (ypclnt == NULL)
317 return (PAM_BUF_ERR);
318
319 if (ypclnt_connect(ypclnt) == -1) {
320 ypclnt_free(ypclnt);
321 return (PAM_SERVICE_ERR);
322 }
323
324 retval = ypclnt_havepasswdd(ypclnt);
325 ypclnt_free(ypclnt);
326 if (retval == 1)
327 return (pam_set_item(pamh, PAM_OLDAUTHTOK, ""));
328 else if (retval == -1)
329 return (PAM_SERVICE_ERR);
330 }
331 #endif
332 if (pwd->pw_passwd[0] == '\0'
333 && openpam_get_option(pamh, PAM_OPT_NULLOK)) {
334 /*
335 * No password case. XXX Are we giving too much away
336 * by not prompting for a password?
337 * XXX check PAM_DISALLOW_NULL_AUTHTOK
338 */
339 old_pass = "";
340 retval = PAM_SUCCESS;
341 } else {
342 retval = pam_get_authtok(pamh,
343 PAM_OLDAUTHTOK, &old_pass, NULL);
344 if (retval != PAM_SUCCESS)
345 return (retval);
346 }
347 PAM_LOG("Got old password");
348 /* always encrypt first */
349 encrypted = crypt(old_pass, pwd->pw_passwd);
350 if (old_pass[0] == '\0' &&
351 !openpam_get_option(pamh, PAM_OPT_NULLOK))
352 return (PAM_PERM_DENIED);
353 if (strcmp(encrypted, pwd->pw_passwd) != 0)
354 return (PAM_PERM_DENIED);
355 }
356 else if (flags & PAM_UPDATE_AUTHTOK) {
357 PAM_LOG("UPDATE round");
358
359 retval = pam_get_authtok(pamh,
360 PAM_OLDAUTHTOK, &old_pass, NULL);
361 if (retval != PAM_SUCCESS)
362 return (retval);
363 PAM_LOG("Got old password");
364
365 /* get new password */
366 for (;;) {
367 retval = pam_get_authtok(pamh,
368 PAM_AUTHTOK, &new_pass, NULL);
369 if (retval != PAM_TRY_AGAIN)
370 break;
371 pam_error(pamh, "Mismatch; try again, EOF to quit.");
372 }
373 PAM_LOG("Got new password");
374 if (retval != PAM_SUCCESS) {
375 PAM_VERBOSE_ERROR("Unable to get new password");
376 return (retval);
377 }
378
379 if (getuid() != 0 && new_pass[0] == '\0' &&
380 !openpam_get_option(pamh, PAM_OPT_NULLOK))
381 return (PAM_PERM_DENIED);
382
383 if ((old_pwd = pw_dup(pwd)) == NULL)
384 return (PAM_BUF_ERR);
385
386 lc = login_getclass(pwd->pw_class);
387 if (login_setcryptfmt(lc, password_hash, NULL) == NULL)
388 openpam_log(PAM_LOG_ERROR,
389 "can't set password cipher, relying on default");
390
391 /* set password expiry date */
392 pwd->pw_change = 0;
393 passwordtime = login_getcaptime(lc, "passwordtime", 0, 0);
394 if (passwordtime > 0)
395 pwd->pw_change = time(NULL) + passwordtime;
396
397 login_close(lc);
398 makesalt(salt);
399 pwd->pw_passwd = crypt(new_pass, salt);
400 #ifdef YP
401 switch (old_pwd->pw_fields & _PWF_SOURCE) {
402 case _PWF_FILES:
403 #endif
404 retval = PAM_SERVICE_ERR;
405 if (pw_init(NULL, NULL))
406 openpam_log(PAM_LOG_ERROR, "pw_init() failed");
407 else if ((pfd = pw_lock()) == -1)
408 openpam_log(PAM_LOG_ERROR, "pw_lock() failed");
409 else if ((tfd = pw_tmp(-1)) == -1)
410 openpam_log(PAM_LOG_ERROR, "pw_tmp() failed");
411 else if (pw_copy(pfd, tfd, pwd, old_pwd) == -1)
412 openpam_log(PAM_LOG_ERROR, "pw_copy() failed");
413 else if (pw_mkdb(pwd->pw_name) == -1)
414 openpam_log(PAM_LOG_ERROR, "pw_mkdb() failed");
415 else
416 retval = PAM_SUCCESS;
417 pw_fini();
418 #ifdef YP
419 break;
420 case _PWF_NIS:
421 yp_domain = yp_server = NULL;
422 (void)pam_get_data(pamh, "yp_domain", &yp_domain);
423 (void)pam_get_data(pamh, "yp_server", &yp_server);
424 ypclnt = ypclnt_new(yp_domain,
425 "passwd.byname", yp_server);
426 if (ypclnt == NULL) {
427 retval = PAM_BUF_ERR;
428 } else if (ypclnt_connect(ypclnt) == -1 ||
429 ypclnt_passwd(ypclnt, pwd, old_pass) == -1) {
430 openpam_log(PAM_LOG_ERROR, "%s", ypclnt->error);
431 retval = PAM_SERVICE_ERR;
432 } else {
433 retval = PAM_SUCCESS;
434 }
435 ypclnt_free(ypclnt);
436 break;
437 default:
438 openpam_log(PAM_LOG_ERROR, "unsupported source 0x%x",
439 pwd->pw_fields & _PWF_SOURCE);
440 retval = PAM_SERVICE_ERR;
441 }
442 #endif
443 free(old_pwd);
444 }
445 else {
446 /* Very bad juju */
447 retval = PAM_ABORT;
448 PAM_LOG("Illegal 'flags'");
449 }
450
451 return (retval);
452 }
453
454 /* Mostly stolen from passwd(1)'s local_passwd.c - markm */
455
456 static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */
457 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
458
459 static void
to64(char * s,long v,int n)460 to64(char *s, long v, int n)
461 {
462 while (--n >= 0) {
463 *s++ = itoa64[v&0x3f];
464 v >>= 6;
465 }
466 }
467
468 /* Salt suitable for traditional DES and MD5 */
469 static void
makesalt(char salt[SALTSIZE+1])470 makesalt(char salt[SALTSIZE + 1])
471 {
472 int i;
473
474 /* These are not really random numbers, they are just
475 * numbers that change to thwart construction of a
476 * dictionary.
477 */
478 for (i = 0; i < SALTSIZE; i += 4)
479 to64(&salt[i], arc4random(), 4);
480 salt[SALTSIZE] = '\0';
481 }
482
483 PAM_MODULE_ENTRY("pam_unix");
484