s3: Fix a segfault with debug level 3 on Solaris
[ddiss/samba.git] / source3 / smbd / password.c
1 /*
2    Unix SMB/CIFS implementation.
3    Password and authentication handling
4    Copyright (C) Andrew Tridgell 1992-1998
5    Copyright (C) Jeremy Allison 2007.
6
7    This program is free software; you can redistribute it and/or modify
8    it under the terms of the GNU General Public License as published by
9    the Free Software Foundation; either version 3 of the License, or
10    (at your option) any later version.
11
12    This program is distributed in the hope that it will be useful,
13    but WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15    GNU General Public License for more details.
16
17    You should have received a copy of the GNU General Public License
18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include "includes.h"
22 #include "system/passwd.h"
23 #include "smbd/smbd.h"
24 #include "smbd/globals.h"
25 #include "../librpc/gen_ndr/netlogon.h"
26 #include "auth.h"
27
28 /* Fix up prototypes for OSX 10.4, where they're missing */
29 #ifndef HAVE_SETNETGRENT_PROTOTYPE
30 extern int setnetgrent(const char* netgroup);
31 #endif
32 #ifndef HAVE_GETNETGRENT_PROTOTYPE
33 extern int getnetgrent(char **host, char **user, char **domain);
34 #endif
35 #ifndef HAVE_ENDNETGRENT_PROTOTYPE
36 extern void endnetgrent(void);
37 #endif
38
39 enum server_allocated_state { SERVER_ALLOCATED_REQUIRED_YES,
40                                 SERVER_ALLOCATED_REQUIRED_NO,
41                                 SERVER_ALLOCATED_REQUIRED_ANY};
42
43 static user_struct *get_valid_user_struct_internal(
44                         struct smbd_server_connection *sconn,
45                         uint16 vuid,
46                         enum server_allocated_state server_allocated)
47 {
48         user_struct *usp;
49         int count=0;
50
51         if (vuid == UID_FIELD_INVALID)
52                 return NULL;
53
54         usp=sconn->smb1.sessions.validated_users;
55         for (;usp;usp=usp->next,count++) {
56                 if (vuid == usp->vuid) {
57                         switch (server_allocated) {
58                                 case SERVER_ALLOCATED_REQUIRED_YES:
59                                         if (usp->session_info == NULL) {
60                                                 continue;
61                                         }
62                                         break;
63                                 case SERVER_ALLOCATED_REQUIRED_NO:
64                                         if (usp->session_info != NULL) {
65                                                 continue;
66                                         }
67                                 case SERVER_ALLOCATED_REQUIRED_ANY:
68                                         break;
69                         }
70                         if (count > 10) {
71                                 DLIST_PROMOTE(sconn->smb1.sessions.validated_users,
72                                               usp);
73                         }
74                         return usp;
75                 }
76         }
77
78         return NULL;
79 }
80
81 /****************************************************************************
82  Check if a uid has been validated, and return an pointer to the user_struct
83  if it has. NULL if not. vuid is biased by an offset. This allows us to
84  tell random client vuid's (normally zero) from valid vuids.
85 ****************************************************************************/
86
87 user_struct *get_valid_user_struct(struct smbd_server_connection *sconn,
88                                    uint16 vuid)
89 {
90         return get_valid_user_struct_internal(sconn, vuid,
91                         SERVER_ALLOCATED_REQUIRED_YES);
92 }
93
94 bool is_partial_auth_vuid(struct smbd_server_connection *sconn, uint16 vuid)
95 {
96         return (get_partial_auth_user_struct(sconn, vuid) != NULL);
97 }
98
99 /****************************************************************************
100  Get the user struct of a partial NTLMSSP login
101 ****************************************************************************/
102
103 user_struct *get_partial_auth_user_struct(struct smbd_server_connection *sconn,
104                                           uint16 vuid)
105 {
106         return get_valid_user_struct_internal(sconn, vuid,
107                         SERVER_ALLOCATED_REQUIRED_NO);
108 }
109
110 /****************************************************************************
111  Invalidate a uid.
112 ****************************************************************************/
113
114 void invalidate_vuid(struct smbd_server_connection *sconn, uint16 vuid)
115 {
116         user_struct *vuser = NULL;
117
118         vuser = get_valid_user_struct_internal(sconn, vuid,
119                         SERVER_ALLOCATED_REQUIRED_ANY);
120         if (vuser == NULL) {
121                 return;
122         }
123
124         session_yield(vuser);
125
126         if (vuser->auth_ntlmssp_state) {
127                 TALLOC_FREE(vuser->auth_ntlmssp_state);
128         }
129
130         DLIST_REMOVE(sconn->smb1.sessions.validated_users, vuser);
131
132         /* clear the vuid from the 'cache' on each connection, and
133            from the vuid 'owner' of connections */
134         conn_clear_vuid_caches(sconn, vuid);
135
136         TALLOC_FREE(vuser);
137         sconn->smb1.sessions.num_validated_vuids--;
138 }
139
140 /****************************************************************************
141  Invalidate all vuid entries for this process.
142 ****************************************************************************/
143
144 void invalidate_all_vuids(struct smbd_server_connection *sconn)
145 {
146         if (sconn->using_smb2) {
147                 return;
148         }
149
150         while (sconn->smb1.sessions.validated_users != NULL) {
151                 invalidate_vuid(sconn,
152                                 sconn->smb1.sessions.validated_users->vuid);
153         }
154 }
155
156 static void increment_next_vuid(uint16_t *vuid)
157 {
158         *vuid += 1;
159
160         /* Check for vuid wrap. */
161         if (*vuid == UID_FIELD_INVALID) {
162                 *vuid = VUID_OFFSET;
163         }
164 }
165
166 /****************************************************
167  Create a new partial auth user struct.
168 *****************************************************/
169
170 int register_initial_vuid(struct smbd_server_connection *sconn)
171 {
172         user_struct *vuser;
173
174         /* Paranoia check. */
175         if(lp_security() == SEC_SHARE) {
176                 smb_panic("register_initial_vuid: "
177                         "Tried to register uid in security=share");
178         }
179
180         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
181         if (sconn->smb1.sessions.num_validated_vuids >= 0xFFFF-VUID_OFFSET) {
182                 return UID_FIELD_INVALID;
183         }
184
185         if((vuser = talloc_zero(NULL, user_struct)) == NULL) {
186                 DEBUG(0,("register_initial_vuid: "
187                                 "Failed to talloc users struct!\n"));
188                 return UID_FIELD_INVALID;
189         }
190
191         /* Allocate a free vuid. Yes this is a linear search... */
192         while( get_valid_user_struct_internal(sconn,
193                         sconn->smb1.sessions.next_vuid,
194                         SERVER_ALLOCATED_REQUIRED_ANY) != NULL ) {
195                 increment_next_vuid(&sconn->smb1.sessions.next_vuid);
196         }
197
198         DEBUG(10,("register_initial_vuid: allocated vuid = %u\n",
199                 (unsigned int)sconn->smb1.sessions.next_vuid ));
200
201         vuser->vuid = sconn->smb1.sessions.next_vuid;
202
203         /*
204          * This happens in an unfinished NTLMSSP session setup. We
205          * need to allocate a vuid between the first and second calls
206          * to NTLMSSP.
207          */
208         increment_next_vuid(&sconn->smb1.sessions.next_vuid);
209         sconn->smb1.sessions.num_validated_vuids++;
210
211         DLIST_ADD(sconn->smb1.sessions.validated_users, vuser);
212         return vuser->vuid;
213 }
214
215 int register_homes_share(const char *username)
216 {
217         int result;
218         struct passwd *pwd;
219
220         result = lp_servicenumber(username);
221         if (result != -1) {
222                 DEBUG(3, ("Using static (or previously created) service for "
223                           "user '%s'; path = '%s'\n", username,
224                           lp_pathname(result)));
225                 return result;
226         }
227
228         pwd = Get_Pwnam_alloc(talloc_tos(), username);
229
230         if ((pwd == NULL) || (pwd->pw_dir[0] == '\0')) {
231                 DEBUG(3, ("No home directory defined for user '%s'\n",
232                           username));
233                 TALLOC_FREE(pwd);
234                 return -1;
235         }
236
237         DEBUG(3, ("Adding homes service for user '%s' using home directory: "
238                   "'%s'\n", username, pwd->pw_dir));
239
240         result = add_home_service(username, username, pwd->pw_dir);
241
242         TALLOC_FREE(pwd);
243         return result;
244 }
245
246 /**
247  *  register that a valid login has been performed, establish 'session'.
248  *  @param session_info The token returned from the authentication process.
249  *   (now 'owned' by register_existing_vuid)
250  *
251  *  @param session_key The User session key for the login session (now also
252  *  'owned' by register_existing_vuid)
253  *
254  *  @param respose_blob The NT challenge-response, if available.  (May be
255  *  freed after this call)
256  *
257  *  @param smb_name The untranslated name of the user
258  *
259  *  @return Newly allocated vuid, biased by an offset. (This allows us to
260  *   tell random client vuid's (normally zero) from valid vuids.)
261  *
262  */
263
264 int register_existing_vuid(struct smbd_server_connection *sconn,
265                         uint16 vuid,
266                         struct auth_serversupplied_info *session_info,
267                         DATA_BLOB response_blob,
268                         const char *smb_name)
269 {
270         fstring tmp;
271         user_struct *vuser;
272
273         vuser = get_partial_auth_user_struct(sconn, vuid);
274         if (!vuser) {
275                 goto fail;
276         }
277
278         /* Use this to keep tabs on all our info from the authentication */
279         vuser->session_info = talloc_move(vuser, &session_info);
280
281         /* This is a potentially untrusted username */
282         alpha_strcpy(tmp, smb_name, ". _-$", sizeof(tmp));
283
284         vuser->session_info->sanitized_username = talloc_strdup(
285                 vuser->session_info, tmp);
286
287         DEBUG(10,("register_existing_vuid: (%u,%u) %s %s %s guest=%d\n",
288                   (unsigned int)vuser->session_info->utok.uid,
289                   (unsigned int)vuser->session_info->utok.gid,
290                   vuser->session_info->unix_name,
291                   vuser->session_info->sanitized_username,
292                   vuser->session_info->info3->base.domain.string,
293                   vuser->session_info->guest ));
294
295         DEBUG(3, ("register_existing_vuid: User name: %s\t"
296                   "Real name: %s\n", vuser->session_info->unix_name,
297                   vuser->session_info->info3->base.full_name.string ?
298                   vuser->session_info->info3->base.full_name.string : ""));
299
300         if (!vuser->session_info->security_token) {
301                 DEBUG(1, ("register_existing_vuid: session_info does not "
302                         "contain a user_token - cannot continue\n"));
303                 goto fail;
304         }
305
306         DEBUG(3,("register_existing_vuid: UNIX uid %d is UNIX user %s, "
307                 "and will be vuid %u\n", (int)vuser->session_info->utok.uid,
308                  vuser->session_info->unix_name, vuser->vuid));
309
310         if (!session_claim(sconn, vuser)) {
311                 DEBUG(1, ("register_existing_vuid: Failed to claim session "
312                         "for vuid=%d\n",
313                         vuser->vuid));
314                 goto fail;
315         }
316
317         /* Register a home dir service for this user if
318         (a) This is not a guest connection,
319         (b) we have a home directory defined
320         (c) there s not an existing static share by that name
321         If a share exists by this name (autoloaded or not) reuse it . */
322
323         vuser->homes_snum = -1;
324
325         if (!vuser->session_info->guest) {
326                 vuser->homes_snum = register_homes_share(
327                         vuser->session_info->unix_name);
328         }
329
330         if (srv_is_signing_negotiated(sconn) &&
331             !vuser->session_info->guest) {
332                 /* Try and turn on server signing on the first non-guest
333                  * sessionsetup. */
334                 srv_set_signing(sconn,
335                                 vuser->session_info->user_session_key,
336                                 response_blob);
337         }
338
339         /* fill in the current_user_info struct */
340         set_current_user_info(
341                 vuser->session_info->sanitized_username,
342                 vuser->session_info->unix_name,
343                 vuser->session_info->info3->base.domain.string);
344
345         return vuser->vuid;
346
347   fail:
348
349         if (vuser) {
350                 invalidate_vuid(sconn, vuid);
351         }
352         return UID_FIELD_INVALID;
353 }
354
355 /****************************************************************************
356  Add a name to the session users list.
357 ****************************************************************************/
358
359 void add_session_user(struct smbd_server_connection *sconn,
360                       const char *user)
361 {
362         struct passwd *pw;
363         char *tmp;
364
365         pw = Get_Pwnam_alloc(talloc_tos(), user);
366
367         if (pw == NULL) {
368                 return;
369         }
370
371         if (sconn->smb1.sessions.session_userlist == NULL) {
372                 sconn->smb1.sessions.session_userlist = SMB_STRDUP(pw->pw_name);
373                 goto done;
374         }
375
376         if (in_list(pw->pw_name,sconn->smb1.sessions.session_userlist,false)) {
377                 goto done;
378         }
379
380         if (strlen(sconn->smb1.sessions.session_userlist) > 128 * 1024) {
381                 DEBUG(3,("add_session_user: session userlist already "
382                          "too large.\n"));
383                 goto done;
384         }
385
386         if (asprintf(&tmp, "%s %s",
387                      sconn->smb1.sessions.session_userlist, pw->pw_name) == -1) {
388                 DEBUG(3, ("asprintf failed\n"));
389                 goto done;
390         }
391
392         SAFE_FREE(sconn->smb1.sessions.session_userlist);
393         sconn->smb1.sessions.session_userlist = tmp;
394  done:
395         TALLOC_FREE(pw);
396 }
397
398 /****************************************************************************
399  In security=share mode we need to store the client workgroup, as that's
400   what Vista uses for the NTLMv2 calculation.
401 ****************************************************************************/
402
403 void add_session_workgroup(struct smbd_server_connection *sconn,
404                            const char *workgroup)
405 {
406         if (sconn->smb1.sessions.session_workgroup) {
407                 SAFE_FREE(sconn->smb1.sessions.session_workgroup);
408         }
409         sconn->smb1.sessions.session_workgroup = smb_xstrdup(workgroup);
410 }
411
412 /****************************************************************************
413  In security=share mode we need to return the client workgroup, as that's
414   what Vista uses for the NTLMv2 calculation.
415 ****************************************************************************/
416
417 const char *get_session_workgroup(struct smbd_server_connection *sconn)
418 {
419         return sconn->smb1.sessions.session_workgroup;
420 }
421
422 /****************************************************************************
423  Check if a username is valid.
424 ****************************************************************************/
425
426 static bool user_ok(const char *user, int snum)
427 {
428         bool ret;
429
430         ret = True;
431
432         if (lp_invalid_users(snum)) {
433                 char **invalid = str_list_copy(talloc_tos(),
434                         lp_invalid_users(snum));
435                 if (invalid &&
436                     str_list_substitute(invalid, "%S", lp_servicename(snum))) {
437
438                         /* This is used in sec=share only, so no current user
439                          * around to pass to str_list_sub_basic() */
440
441                         if ( invalid && str_list_sub_basic(invalid, "", "") ) {
442                                 ret = !user_in_list(talloc_tos(), user,
443                                                     (const char **)invalid);
444                         }
445                 }
446                 TALLOC_FREE(invalid);
447         }
448
449         if (ret && lp_valid_users(snum)) {
450                 char **valid = str_list_copy(talloc_tos(),
451                         lp_valid_users(snum));
452                 if ( valid &&
453                      str_list_substitute(valid, "%S", lp_servicename(snum)) ) {
454
455                         /* This is used in sec=share only, so no current user
456                          * around to pass to str_list_sub_basic() */
457
458                         if ( valid && str_list_sub_basic(valid, "", "") ) {
459                                 ret = user_in_list(talloc_tos(), user,
460                                                    (const char **)valid);
461                         }
462                 }
463                 TALLOC_FREE(valid);
464         }
465
466         if (ret && lp_onlyuser(snum)) {
467                 char **user_list = str_list_make_v3(
468                         talloc_tos(), lp_username(snum), NULL);
469                 if (user_list &&
470                     str_list_substitute(user_list, "%S",
471                                         lp_servicename(snum))) {
472                         ret = user_in_list(talloc_tos(), user,
473                                            (const char **)user_list);
474                 }
475                 TALLOC_FREE(user_list);
476         }
477
478         return(ret);
479 }
480
481 /****************************************************************************
482  Validate a group username entry. Return the username or NULL.
483 ****************************************************************************/
484
485 static char *validate_group(struct smbd_server_connection *sconn,
486                             char *group, DATA_BLOB password,int snum)
487 {
488 #ifdef HAVE_NETGROUP
489         {
490                 char *host, *user, *domain;
491                 struct auth_context *actx = sconn->smb1.negprot.auth_context;
492                 bool enc = sconn->smb1.negprot.encrypted_passwords;
493                 setnetgrent(group);
494                 while (getnetgrent(&host, &user, &domain)) {
495                         if (user) {
496                                 if (user_ok(user, snum) &&
497                                     password_ok(actx, enc,
498                                                 get_session_workgroup(sconn),
499                                                 user,password)) {
500                                         endnetgrent();
501                                         return(user);
502                                 }
503                         }
504                 }
505                 endnetgrent();
506         }
507 #endif
508
509 #ifdef HAVE_GETGRENT
510         {
511                 struct group *gptr;
512                 struct auth_context *actx = sconn->smb1.negprot.auth_context;
513                 bool enc = sconn->smb1.negprot.encrypted_passwords;
514
515                 setgrent();
516                 while ((gptr = (struct group *)getgrent())) {
517                         if (strequal(gptr->gr_name,group))
518                                 break;
519                 }
520
521                 /*
522                  * As user_ok can recurse doing a getgrent(), we must
523                  * copy the member list onto the heap before
524                  * use. Bug pointed out by leon@eatworms.swmed.edu.
525                  */
526
527                 if (gptr) {
528                         char *member_list = NULL;
529                         size_t list_len = 0;
530                         char *member;
531                         int i;
532
533                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
534                                 list_len += strlen(gptr->gr_mem[i])+1;
535                         }
536                         list_len++;
537
538                         member_list = (char *)SMB_MALLOC(list_len);
539                         if (!member_list) {
540                                 endgrent();
541                                 return NULL;
542                         }
543
544                         *member_list = '\0';
545                         member = member_list;
546
547                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
548                                 size_t member_len = strlen(gptr->gr_mem[i])+1;
549
550                                 DEBUG(10,("validate_group: = gr_mem = "
551                                           "%s\n", gptr->gr_mem[i]));
552
553                                 strlcpy(member, gptr->gr_mem[i],
554                                         list_len - (member-member_list));
555                                 member += member_len;
556                         }
557
558                         endgrent();
559
560                         member = member_list;
561                         while (*member) {
562                                 if (user_ok(member,snum) &&
563                                     password_ok(actx, enc,
564                                                 get_session_workgroup(sconn),
565                                                 member,password)) {
566                                         char *name = talloc_strdup(talloc_tos(),
567                                                                 member);
568                                         SAFE_FREE(member_list);
569                                         return name;
570                                 }
571
572                                 DEBUG(10,("validate_group = member = %s\n",
573                                           member));
574
575                                 member += strlen(member) + 1;
576                         }
577
578                         SAFE_FREE(member_list);
579                 } else {
580                         endgrent();
581                         return NULL;
582                 }
583         }
584 #endif
585         return(NULL);
586 }
587
588 /****************************************************************************
589  Check for authority to login to a service with a given username/password.
590  Note this is *NOT* used when logging on using sessionsetup_and_X.
591 ****************************************************************************/
592
593 bool authorise_login(struct smbd_server_connection *sconn,
594                      int snum, fstring user, DATA_BLOB password,
595                      bool *guest)
596 {
597         bool ok = False;
598         struct auth_context *actx = sconn->smb1.negprot.auth_context;
599         bool enc = sconn->smb1.negprot.encrypted_passwords;
600
601 #ifdef DEBUG_PASSWORD
602         DEBUG(100,("authorise_login: checking authorisation on "
603                    "user=%s pass=%s\n", user,password.data));
604 #endif
605
606         *guest = False;
607
608         /* there are several possibilities:
609                 1) login as the given user with given password
610                 2) login as a previously registered username with the given
611                    password
612                 3) login as a session list username with the given password
613                 4) login as a previously validated user/password pair
614                 5) login as the "user =" user with given password
615                 6) login as the "user =" user with no password
616                    (guest connection)
617                 7) login as guest user with no password
618
619                 if the service is guest_only then steps 1 to 5 are skipped
620         */
621
622         /* now check the list of session users */
623         if (!ok) {
624                 char *auser;
625                 char *user_list = NULL;
626                 char *saveptr;
627
628                 if (sconn->smb1.sessions.session_userlist)
629                         user_list = SMB_STRDUP(sconn->smb1.sessions.session_userlist);
630                 else
631                         user_list = SMB_STRDUP("");
632
633                 if (!user_list)
634                         return(False);
635
636                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
637                      !ok && auser;
638                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
639                         fstring user2;
640                         fstrcpy(user2,auser);
641                         if (!user_ok(user2,snum))
642                                 continue;
643
644                         if (password_ok(actx, enc,
645                                         get_session_workgroup(sconn),
646                                         user2,password)) {
647                                 ok = True;
648                                 fstrcpy(user,user2);
649                                 DEBUG(3,("authorise_login: ACCEPTED: session "
650                                          "list username (%s) and given "
651                                          "password ok\n", user));
652                         }
653                 }
654
655                 SAFE_FREE(user_list);
656         }
657
658         /* check the user= fields and the given password */
659         if (!ok && lp_username(snum)) {
660                 TALLOC_CTX *ctx = talloc_tos();
661                 char *auser;
662                 char *user_list = talloc_strdup(ctx, lp_username(snum));
663                 char *saveptr;
664
665                 if (!user_list) {
666                         goto check_guest;
667                 }
668
669                 user_list = talloc_string_sub(ctx,
670                                 user_list,
671                                 "%S",
672                                 lp_servicename(snum));
673
674                 if (!user_list) {
675                         goto check_guest;
676                 }
677
678                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
679                      auser && !ok;
680                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
681                         if (*auser == '@') {
682                                 auser = validate_group(sconn,auser+1,
683                                                        password,snum);
684                                 if (auser) {
685                                         ok = True;
686                                         fstrcpy(user,auser);
687                                         DEBUG(3,("authorise_login: ACCEPTED: "
688                                                  "group username and given "
689                                                  "password ok (%s)\n", user));
690                                 }
691                         } else {
692                                 fstring user2;
693                                 fstrcpy(user2,auser);
694                                 if (user_ok(user2,snum) &&
695                                     password_ok(actx, enc,
696                                                 get_session_workgroup(sconn),
697                                                 user2,password)) {
698                                         ok = True;
699                                         fstrcpy(user,user2);
700                                         DEBUG(3,("authorise_login: ACCEPTED: "
701                                                  "user list username and "
702                                                  "given password ok (%s)\n",
703                                                  user));
704                                 }
705                         }
706                 }
707         }
708
709   check_guest:
710
711         /* check for a normal guest connection */
712         if (!ok && GUEST_OK(snum)) {
713                 struct passwd *guest_pw;
714                 fstring guestname;
715                 fstrcpy(guestname,lp_guestaccount());
716                 guest_pw = Get_Pwnam_alloc(talloc_tos(), guestname);
717                 if (guest_pw != NULL) {
718                         fstrcpy(user,guestname);
719                         ok = True;
720                         DEBUG(3,("authorise_login: ACCEPTED: guest account "
721                                  "and guest ok (%s)\n", user));
722                 } else {
723                         DEBUG(0,("authorise_login: Invalid guest account "
724                                  "%s??\n",guestname));
725                 }
726                 TALLOC_FREE(guest_pw);
727                 *guest = True;
728         }
729
730         if (ok && !user_ok(user, snum)) {
731                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
732                 ok = False;
733         }
734
735         return(ok);
736 }