s3:auth: add comment to nulling out stolen sampass
[amitay/samba.git] / source3 / auth / auth_sam.c
1 /* 
2    Unix SMB/CIFS implementation.
3    Password and authentication handling
4    Copyright (C) Andrew Tridgell              1992-2000
5    Copyright (C) Luke Kenneth Casson Leighton 1996-2000
6    Copyright (C) Andrew Bartlett              2001-2003
7    Copyright (C) Gerald Carter                2003
8
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18
19    You should have received a copy of the GNU General Public License
20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
21 */
22
23 #include "includes.h"
24 #include "../libcli/auth/libcli_auth.h"
25
26 #undef DBGC_CLASS
27 #define DBGC_CLASS DBGC_AUTH
28
29 /****************************************************************************
30  Do a specific test for an smb password being correct, given a smb_password and
31  the lanman and NT responses.
32 ****************************************************************************/
33
34 static NTSTATUS sam_password_ok(const struct auth_context *auth_context,
35                                 TALLOC_CTX *mem_ctx,
36                                 const char *username,
37                                 uint32_t acct_ctrl,
38                                 const uint8_t *lm_pw,
39                                 const uint8_t *nt_pw,
40                                 const struct auth_usersupplied_info *user_info,
41                                 DATA_BLOB *user_sess_key, 
42                                 DATA_BLOB *lm_sess_key)
43 {
44         struct samr_Password _lm_hash, _nt_hash, _client_lm_hash, _client_nt_hash;
45         struct samr_Password *lm_hash = NULL;
46         struct samr_Password *nt_hash = NULL;
47         struct samr_Password *client_lm_hash = NULL;
48         struct samr_Password *client_nt_hash = NULL;
49
50         *user_sess_key = data_blob_null;
51         *lm_sess_key = data_blob_null;
52
53         if (acct_ctrl & ACB_PWNOTREQ) {
54                 if (lp_null_passwords()) {
55                         DEBUG(3,("Account for user '%s' has no password and null passwords are allowed.\n", username));
56                         return NT_STATUS_OK;
57                 } else {
58                         DEBUG(3,("Account for user '%s' has no password and null passwords are NOT allowed.\n", username));
59                         return NT_STATUS_LOGON_FAILURE;
60                 }               
61         }
62
63         if (lm_pw) {
64                 memcpy(_lm_hash.hash, lm_pw, sizeof(_lm_hash.hash));
65                 lm_hash = &_lm_hash;
66         }
67         if (nt_pw) {
68                 memcpy(_nt_hash.hash, nt_pw, sizeof(_nt_hash.hash));
69                 nt_hash = &_nt_hash;
70         }
71         if (user_info->lm_interactive_pwd.data && sizeof(_client_lm_hash.hash) == user_info->lm_interactive_pwd.length) {
72                 memcpy(_client_lm_hash.hash, user_info->lm_interactive_pwd.data, sizeof(_lm_hash.hash));
73                 client_lm_hash = &_client_lm_hash;
74         }
75         if (user_info->nt_interactive_pwd.data && sizeof(_client_nt_hash.hash) == user_info->nt_interactive_pwd.length) {
76                 memcpy(_client_nt_hash.hash, user_info->nt_interactive_pwd.data, sizeof(_nt_hash.hash));
77                 client_nt_hash = &_client_nt_hash;
78         }
79
80         if (client_lm_hash || client_nt_hash) {
81                 *user_sess_key = data_blob_talloc(mem_ctx, NULL, 16);
82                 if (!user_sess_key->data) {
83                         return NT_STATUS_NO_MEMORY;
84                 }
85                 SMBsesskeygen_ntv1(nt_pw, user_sess_key->data);
86                 return hash_password_check(mem_ctx, lp_lanman_auth(),
87                                            client_lm_hash,
88                                            client_nt_hash,
89                                            username, 
90                                            lm_hash,
91                                            nt_hash);
92         } else {
93                 return ntlm_password_check(mem_ctx, lp_lanman_auth(),
94                                            lp_ntlm_auth(),
95                                            user_info->logon_parameters,
96                                            &auth_context->challenge, 
97                                            &user_info->lm_resp, &user_info->nt_resp, 
98                                            username, 
99                                            user_info->smb_name,
100                                            user_info->client_domain,
101                                            lm_hash,
102                                            nt_hash,
103                                            user_sess_key, lm_sess_key);
104         }
105 }
106
107 /****************************************************************************
108  Check if a user is allowed to logon at this time. Note this is the
109  servers local time, as logon hours are just specified as a weekly
110  bitmask.
111 ****************************************************************************/
112
113 static bool logon_hours_ok(struct samu *sampass)
114 {
115         /* In logon hours first bit is Sunday from 12AM to 1AM */
116         const uint8 *hours;
117         struct tm *utctime;
118         time_t lasttime;
119         const char *asct;
120         uint8 bitmask, bitpos;
121
122         hours = pdb_get_hours(sampass);
123         if (!hours) {
124                 DEBUG(5,("logon_hours_ok: No hours restrictions for user %s\n",pdb_get_username(sampass)));
125                 return True;
126         }
127
128         lasttime = time(NULL);
129         utctime = gmtime(&lasttime);
130         if (!utctime) {
131                 DEBUG(1, ("logon_hours_ok: failed to get gmtime. Failing logon for user %s\n",
132                         pdb_get_username(sampass) ));
133                 return False;
134         }
135
136         /* find the corresponding byte and bit */
137         bitpos = (utctime->tm_wday * 24 + utctime->tm_hour) % 168;
138         bitmask = 1 << (bitpos % 8);
139
140         if (! (hours[bitpos/8] & bitmask)) {
141                 struct tm *t = localtime(&lasttime);
142                 if (!t) {
143                         asct = "INVALID TIME";
144                 } else {
145                         asct = asctime(t);
146                         if (!asct) {
147                                 asct = "INVALID TIME";
148                         }
149                 }
150
151                 DEBUG(1, ("logon_hours_ok: Account for user %s not allowed to "
152                           "logon at this time (%s).\n",
153                           pdb_get_username(sampass), asct ));
154                 return False;
155         }
156
157         asct = asctime(utctime);
158         DEBUG(5,("logon_hours_ok: user %s allowed to logon at this time (%s)\n",
159                 pdb_get_username(sampass), asct ? asct : "UNKNOWN TIME" ));
160
161         return True;
162 }
163
164 /****************************************************************************
165  Do a specific test for a struct samu being valid for this connection
166  (ie not disabled, expired and the like).
167 ****************************************************************************/
168
169 static NTSTATUS sam_account_ok(TALLOC_CTX *mem_ctx,
170                                struct samu *sampass, 
171                                const struct auth_usersupplied_info *user_info)
172 {
173         uint32  acct_ctrl = pdb_get_acct_ctrl(sampass);
174         char *workstation_list;
175         time_t kickoff_time;
176
177         DEBUG(4,("sam_account_ok: Checking SMB password for user %s\n",pdb_get_username(sampass)));
178
179         /* Quit if the account was disabled. */
180         if (acct_ctrl & ACB_DISABLED) {
181                 DEBUG(1,("sam_account_ok: Account for user '%s' was disabled.\n", pdb_get_username(sampass)));
182                 return NT_STATUS_ACCOUNT_DISABLED;
183         }
184
185         /* Quit if the account was locked out. */
186         if (acct_ctrl & ACB_AUTOLOCK) {
187                 DEBUG(1,("sam_account_ok: Account for user %s was locked out.\n", pdb_get_username(sampass)));
188                 return NT_STATUS_ACCOUNT_LOCKED_OUT;
189         }
190
191         /* Quit if the account is not allowed to logon at this time. */
192         if (! logon_hours_ok(sampass)) {
193                 return NT_STATUS_INVALID_LOGON_HOURS;
194         }
195
196         /* Test account expire time */
197
198         kickoff_time = pdb_get_kickoff_time(sampass);
199         if (kickoff_time != 0 && time(NULL) > kickoff_time) {
200                 DEBUG(1,("sam_account_ok: Account for user '%s' has expired.\n", pdb_get_username(sampass)));
201                 DEBUG(3,("sam_account_ok: Account expired at '%ld' unix time.\n", (long)kickoff_time));
202                 return NT_STATUS_ACCOUNT_EXPIRED;
203         }
204
205         if (!(pdb_get_acct_ctrl(sampass) & ACB_PWNOEXP) && !(pdb_get_acct_ctrl(sampass) & ACB_PWNOTREQ)) {
206                 time_t must_change_time = pdb_get_pass_must_change_time(sampass);
207                 time_t last_set_time = pdb_get_pass_last_set_time(sampass);
208
209                 /* check for immediate expiry "must change at next logon" 
210                  * for a user account. */
211                 if (((acct_ctrl & (ACB_WSTRUST|ACB_SVRTRUST)) == 0) && (last_set_time == 0)) {
212                         DEBUG(1,("sam_account_ok: Account for user '%s' password must change!\n", pdb_get_username(sampass)));
213                         return NT_STATUS_PASSWORD_MUST_CHANGE;
214                 }
215
216                 /* check for expired password */
217                 if (must_change_time < time(NULL) && must_change_time != 0) {
218                         DEBUG(1,("sam_account_ok: Account for user '%s' password expired!\n", pdb_get_username(sampass)));
219                         DEBUG(1,("sam_account_ok: Password expired at '%s' (%ld) unix time.\n", http_timestring(talloc_tos(), must_change_time), (long)must_change_time));
220                         return NT_STATUS_PASSWORD_EXPIRED;
221                 }
222         }
223
224         /* Test workstation. Workstation list is comma separated. */
225
226         workstation_list = talloc_strdup(mem_ctx, pdb_get_workstations(sampass));
227         if (!workstation_list)
228                 return NT_STATUS_NO_MEMORY;
229
230         if (*workstation_list) {
231                 bool invalid_ws = True;
232                 char *tok = NULL;
233                 const char *s = workstation_list;
234                 char *machine_name = talloc_asprintf(mem_ctx, "%s$", user_info->wksta_name);
235
236                 if (machine_name == NULL)
237                         return NT_STATUS_NO_MEMORY;
238
239                 while (next_token_talloc(mem_ctx, &s, &tok, ",")) {
240                         DEBUG(10,("sam_account_ok: checking for workstation match %s and %s\n",
241                                   tok, user_info->wksta_name));
242                         if(strequal(tok, user_info->wksta_name)) {
243                                 invalid_ws = False;
244                                 break;
245                         }
246                         if (tok[0] == '+') {
247                                 DEBUG(10,("sam_account_ok: checking for workstation %s in group: %s\n", 
248                                         machine_name, tok + 1));
249                                 if (user_in_group(machine_name, tok + 1)) {
250                                         invalid_ws = False;
251                                         break;
252                                 }
253                         }
254                         TALLOC_FREE(tok);
255                 }
256                 TALLOC_FREE(tok);
257                 TALLOC_FREE(machine_name);
258
259                 if (invalid_ws)
260                         return NT_STATUS_INVALID_WORKSTATION;
261         }
262
263         if (acct_ctrl & ACB_DOMTRUST) {
264                 DEBUG(2,("sam_account_ok: Domain trust account %s denied by server\n", pdb_get_username(sampass)));
265                 return NT_STATUS_NOLOGON_INTERDOMAIN_TRUST_ACCOUNT;
266         }
267
268         if (acct_ctrl & ACB_SVRTRUST) {
269                 if (!(user_info->logon_parameters & MSV1_0_ALLOW_SERVER_TRUST_ACCOUNT)) {
270                         DEBUG(2,("sam_account_ok: Server trust account %s denied by server\n", pdb_get_username(sampass)));
271                         return NT_STATUS_NOLOGON_SERVER_TRUST_ACCOUNT;
272                 }
273         }
274
275         if (acct_ctrl & ACB_WSTRUST) {
276                 if (!(user_info->logon_parameters & MSV1_0_ALLOW_WORKSTATION_TRUST_ACCOUNT)) {
277                         DEBUG(2,("sam_account_ok: Wksta trust account %s denied by server\n", pdb_get_username(sampass)));
278                         return NT_STATUS_NOLOGON_WORKSTATION_TRUST_ACCOUNT;
279                 }
280         }
281         return NT_STATUS_OK;
282 }
283
284 /**
285  * Check whether the given password is one of the last two
286  * password history entries. If so, the bad pwcount should
287  * not be incremented even thought the actual password check
288  * failed.
289  */
290 static bool need_to_increment_bad_pw_count(
291         const struct auth_context *auth_context,
292         struct samu* sampass,
293         const struct auth_usersupplied_info *user_info)
294 {
295         uint8_t i;
296         const uint8_t *pwhistory;
297         uint32_t pwhistory_len;
298         uint32_t policy_pwhistory_len;
299         uint32_t acct_ctrl;
300         const char *username;
301         TALLOC_CTX *mem_ctx = talloc_stackframe();
302         bool result = true;
303
304         pdb_get_account_policy(PDB_POLICY_PASSWORD_HISTORY,
305                                &policy_pwhistory_len);
306         if (policy_pwhistory_len == 0) {
307                 goto done;
308         }
309
310         pwhistory = pdb_get_pw_history(sampass, &pwhistory_len);
311         if (!pwhistory || pwhistory_len == 0) {
312                 goto done;
313         }
314
315         acct_ctrl = pdb_get_acct_ctrl(sampass);
316         username = pdb_get_username(sampass);
317
318         for (i=1; i < MIN(MIN(3, policy_pwhistory_len), pwhistory_len); i++) {
319                 static const uint8_t zero16[SALTED_MD5_HASH_LEN];
320                 const uint8_t *salt;
321                 const uint8_t *nt_pw;
322                 NTSTATUS status;
323                 DATA_BLOB user_sess_key = data_blob_null;
324                 DATA_BLOB lm_sess_key = data_blob_null;
325
326                 salt = &pwhistory[i*PW_HISTORY_ENTRY_LEN];
327                 nt_pw = salt + PW_HISTORY_SALT_LEN;
328
329                 if (memcmp(zero16, nt_pw, NT_HASH_LEN) == 0) {
330                         /* skip zero password hash */
331                         continue;
332                 }
333
334                 if (memcmp(zero16, salt, PW_HISTORY_SALT_LEN) != 0) {
335                         /* skip nonzero salt (old format entry) */
336                         continue;
337                 }
338
339                 status = sam_password_ok(auth_context, mem_ctx,
340                                          username, acct_ctrl, NULL, nt_pw,
341                                          user_info, &user_sess_key, &lm_sess_key);
342                 if (NT_STATUS_IS_OK(status)) {
343                         result = false;
344                         break;
345                 }
346         }
347
348 done:
349         TALLOC_FREE(mem_ctx);
350         return result;
351 }
352
353 /****************************************************************************
354 check if a username/password is OK assuming the password is a 24 byte
355 SMB hash supplied in the user_info structure
356 return an NT_STATUS constant.
357 ****************************************************************************/
358
359 static NTSTATUS check_sam_security(const struct auth_context *auth_context,
360                                    void *my_private_data, 
361                                    TALLOC_CTX *mem_ctx,
362                                    const struct auth_usersupplied_info *user_info,
363                                    struct auth_serversupplied_info **server_info)
364 {
365         struct samu *sampass=NULL;
366         bool ret;
367         NTSTATUS nt_status;
368         NTSTATUS update_login_attempts_status;
369         DATA_BLOB user_sess_key = data_blob_null;
370         DATA_BLOB lm_sess_key = data_blob_null;
371         bool updated_autolock = False, updated_badpw = False;
372         uint32_t acct_ctrl;
373         const char *username;
374         const uint8_t *nt_pw;
375         const uint8_t *lm_pw;
376
377         if (!user_info || !auth_context) {
378                 return NT_STATUS_UNSUCCESSFUL;
379         }
380
381         /* the returned struct gets kept on the server_info, by means
382            of a steal further down */
383
384         sampass = samu_new(mem_ctx);
385         if (sampass == NULL) {
386                 return NT_STATUS_NO_MEMORY;
387         }
388
389         /* get the account information */
390
391         become_root();
392         ret = pdb_getsampwnam(sampass, user_info->internal_username);
393         unbecome_root();
394
395         if (ret == False) {
396                 DEBUG(3,("check_sam_security: Couldn't find user '%s' in "
397                          "passdb.\n", user_info->internal_username));
398                 TALLOC_FREE(sampass);
399                 return NT_STATUS_NO_SUCH_USER;
400         }
401
402         acct_ctrl = pdb_get_acct_ctrl(sampass);
403         username = pdb_get_username(sampass);
404         nt_pw = pdb_get_nt_passwd(sampass);
405         lm_pw = pdb_get_lanman_passwd(sampass);
406
407         /* see if autolock flag needs to be updated */
408         if (acct_ctrl & ACB_NORMAL)
409                 pdb_update_autolock_flag(sampass, &updated_autolock);
410         /* Quit if the account was locked out. */
411         if (acct_ctrl & ACB_AUTOLOCK) {
412                 DEBUG(3,("check_sam_security: Account for user %s was locked out.\n", username));
413                 return NT_STATUS_ACCOUNT_LOCKED_OUT;
414         }
415
416         nt_status = sam_password_ok(auth_context, mem_ctx,
417                                     username, acct_ctrl, lm_pw, nt_pw,
418                                     user_info, &user_sess_key, &lm_sess_key);
419
420         /* Notify passdb backend of login success/failure. If not 
421            NT_STATUS_OK the backend doesn't like the login */
422
423         update_login_attempts_status = pdb_update_login_attempts(sampass, NT_STATUS_IS_OK(nt_status));
424
425         if (!NT_STATUS_IS_OK(nt_status)) {
426                 bool increment_bad_pw_count = false;
427
428                 if (NT_STATUS_EQUAL(nt_status,NT_STATUS_WRONG_PASSWORD) && 
429                     acct_ctrl & ACB_NORMAL &&
430                     NT_STATUS_IS_OK(update_login_attempts_status)) 
431                 {
432                         increment_bad_pw_count =
433                                 need_to_increment_bad_pw_count(auth_context,
434                                                                sampass,
435                                                                user_info);
436                 }
437
438                 if (increment_bad_pw_count) {
439                         pdb_increment_bad_password_count(sampass);
440                         updated_badpw = True;
441                 } else {
442                         pdb_update_bad_password_count(sampass, 
443                                                       &updated_badpw);
444                 }
445                 if (updated_autolock || updated_badpw){
446                         NTSTATUS status;
447
448                         become_root();
449                         status = pdb_update_sam_account(sampass);
450                         unbecome_root();
451
452                         if (!NT_STATUS_IS_OK(status)) {
453                                 DEBUG(1, ("Failed to modify entry: %s\n",
454                                           nt_errstr(status)));
455                         }
456                 }
457                 goto done;
458         }
459
460         if ((acct_ctrl & ACB_NORMAL) &&
461             (pdb_get_bad_password_count(sampass) > 0)){
462                 pdb_set_bad_password_count(sampass, 0, PDB_CHANGED);
463                 pdb_set_bad_password_time(sampass, 0, PDB_CHANGED);
464                 updated_badpw = True;
465         }
466
467         if (updated_autolock || updated_badpw){
468                 NTSTATUS status;
469
470                 become_root();
471                 status = pdb_update_sam_account(sampass);
472                 unbecome_root();
473
474                 if (!NT_STATUS_IS_OK(status)) {
475                         DEBUG(1, ("Failed to modify entry: %s\n",
476                                   nt_errstr(status)));
477                 }
478         }
479
480         nt_status = sam_account_ok(mem_ctx, sampass, user_info);
481
482         if (!NT_STATUS_IS_OK(nt_status)) {
483                 goto done;
484         }
485
486         become_root();
487         nt_status = make_server_info_sam(server_info, sampass);
488         unbecome_root();
489         /*
490          * sampass has been stolen to server_info.
491          * So NULL it out to prevent segfaults.
492          */
493         sampass = NULL;
494
495         if (!NT_STATUS_IS_OK(nt_status)) {
496                 DEBUG(0,("check_sam_security: make_server_info_sam() failed with '%s'\n", nt_errstr(nt_status)));
497                 goto done;
498         }
499
500         (*server_info)->user_session_key =
501                 data_blob_talloc(*server_info, user_sess_key.data,
502                                  user_sess_key.length);
503         data_blob_free(&user_sess_key);
504
505         (*server_info)->lm_session_key =
506                 data_blob_talloc(*server_info, lm_sess_key.data,
507                                  lm_sess_key.length);
508         data_blob_free(&lm_sess_key);
509
510         (*server_info)->nss_token |= user_info->was_mapped;
511
512 done:
513         TALLOC_FREE(sampass);
514         data_blob_free(&user_sess_key);
515         data_blob_free(&lm_sess_key);
516         return nt_status;
517 }
518
519 /* module initialisation */
520 static NTSTATUS auth_init_sam_ignoredomain(struct auth_context *auth_context, const char *param, auth_methods **auth_method) 
521 {
522         if (!make_auth_methods(auth_context, auth_method)) {
523                 return NT_STATUS_NO_MEMORY;
524         }
525
526         (*auth_method)->auth = check_sam_security;      
527         (*auth_method)->name = "sam_ignoredomain";
528         return NT_STATUS_OK;
529 }
530
531
532 /****************************************************************************
533 Check SAM security (above) but with a few extra checks.
534 ****************************************************************************/
535
536 static NTSTATUS check_samstrict_security(const struct auth_context *auth_context,
537                                          void *my_private_data, 
538                                          TALLOC_CTX *mem_ctx,
539                                          const struct auth_usersupplied_info *user_info,
540                                          struct auth_serversupplied_info **server_info)
541 {
542         bool is_local_name, is_my_domain;
543
544         if (!user_info || !auth_context) {
545                 return NT_STATUS_LOGON_FAILURE;
546         }
547
548         is_local_name = is_myname(user_info->domain);
549         is_my_domain  = strequal(user_info->domain, lp_workgroup());
550
551         /* check whether or not we service this domain/workgroup name */
552
553         switch ( lp_server_role() ) {
554                 case ROLE_STANDALONE:
555                 case ROLE_DOMAIN_MEMBER:
556                         if ( !is_local_name ) {
557                                 DEBUG(6,("check_samstrict_security: %s is not one of my local names (%s)\n",
558                                         user_info->domain, (lp_server_role() == ROLE_DOMAIN_MEMBER 
559                                         ? "ROLE_DOMAIN_MEMBER" : "ROLE_STANDALONE") ));
560                                 return NT_STATUS_NOT_IMPLEMENTED;
561                         }
562                 case ROLE_DOMAIN_PDC:
563                 case ROLE_DOMAIN_BDC:
564                         if ( !is_local_name && !is_my_domain ) {
565                                 DEBUG(6,("check_samstrict_security: %s is not one of my local names or domain name (DC)\n",
566                                         user_info->domain));
567                                 return NT_STATUS_NOT_IMPLEMENTED;
568                         }
569                 default: /* name is ok */
570                         break;
571         }
572
573         return check_sam_security(auth_context, my_private_data, mem_ctx, user_info, server_info);
574 }
575
576 /* module initialisation */
577 static NTSTATUS auth_init_sam(struct auth_context *auth_context, const char *param, auth_methods **auth_method) 
578 {
579         if (!make_auth_methods(auth_context, auth_method)) {
580                 return NT_STATUS_NO_MEMORY;
581         }
582
583         (*auth_method)->auth = check_samstrict_security;
584         (*auth_method)->name = "sam";
585         return NT_STATUS_OK;
586 }
587
588 NTSTATUS auth_sam_init(void)
589 {
590         smb_register_auth(AUTH_INTERFACE_VERSION, "sam", auth_init_sam);
591         smb_register_auth(AUTH_INTERFACE_VERSION, "sam_ignoredomain", auth_init_sam_ignoredomain);
592         return NT_STATUS_OK;
593 }