4b38de7ecafe6b1155ddbfd855c08cf68e21617a
[metze/samba/wip.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
299         if (!vuser->session_info->security_token) {
300                 DEBUG(1, ("register_existing_vuid: session_info does not "
301                         "contain a user_token - cannot continue\n"));
302                 goto fail;
303         }
304
305         DEBUG(3,("register_existing_vuid: UNIX uid %d is UNIX user %s, "
306                 "and will be vuid %u\n", (int)vuser->session_info->utok.uid,
307                  vuser->session_info->unix_name, vuser->vuid));
308
309         if (!session_claim(sconn, vuser)) {
310                 DEBUG(1, ("register_existing_vuid: Failed to claim session "
311                         "for vuid=%d\n",
312                         vuser->vuid));
313                 goto fail;
314         }
315
316         /* Register a home dir service for this user if
317         (a) This is not a guest connection,
318         (b) we have a home directory defined
319         (c) there s not an existing static share by that name
320         If a share exists by this name (autoloaded or not) reuse it . */
321
322         vuser->homes_snum = -1;
323
324         if (!vuser->session_info->guest) {
325                 vuser->homes_snum = register_homes_share(
326                         vuser->session_info->unix_name);
327         }
328
329         if (srv_is_signing_negotiated(sconn) &&
330             !vuser->session_info->guest) {
331                 /* Try and turn on server signing on the first non-guest
332                  * sessionsetup. */
333                 srv_set_signing(sconn,
334                                 vuser->session_info->user_session_key,
335                                 response_blob);
336         }
337
338         /* fill in the current_user_info struct */
339         set_current_user_info(
340                 vuser->session_info->sanitized_username,
341                 vuser->session_info->unix_name,
342                 vuser->session_info->info3->base.domain.string);
343
344         return vuser->vuid;
345
346   fail:
347
348         if (vuser) {
349                 invalidate_vuid(sconn, vuid);
350         }
351         return UID_FIELD_INVALID;
352 }
353
354 /****************************************************************************
355  Add a name to the session users list.
356 ****************************************************************************/
357
358 void add_session_user(struct smbd_server_connection *sconn,
359                       const char *user)
360 {
361         struct passwd *pw;
362         char *tmp;
363
364         pw = Get_Pwnam_alloc(talloc_tos(), user);
365
366         if (pw == NULL) {
367                 return;
368         }
369
370         if (sconn->smb1.sessions.session_userlist == NULL) {
371                 sconn->smb1.sessions.session_userlist = SMB_STRDUP(pw->pw_name);
372                 goto done;
373         }
374
375         if (in_list(pw->pw_name,sconn->smb1.sessions.session_userlist,false)) {
376                 goto done;
377         }
378
379         if (strlen(sconn->smb1.sessions.session_userlist) > 128 * 1024) {
380                 DEBUG(3,("add_session_user: session userlist already "
381                          "too large.\n"));
382                 goto done;
383         }
384
385         if (asprintf(&tmp, "%s %s",
386                      sconn->smb1.sessions.session_userlist, pw->pw_name) == -1) {
387                 DEBUG(3, ("asprintf failed\n"));
388                 goto done;
389         }
390
391         SAFE_FREE(sconn->smb1.sessions.session_userlist);
392         sconn->smb1.sessions.session_userlist = tmp;
393  done:
394         TALLOC_FREE(pw);
395 }
396
397 /****************************************************************************
398  In security=share mode we need to store the client workgroup, as that's
399   what Vista uses for the NTLMv2 calculation.
400 ****************************************************************************/
401
402 void add_session_workgroup(struct smbd_server_connection *sconn,
403                            const char *workgroup)
404 {
405         if (sconn->smb1.sessions.session_workgroup) {
406                 SAFE_FREE(sconn->smb1.sessions.session_workgroup);
407         }
408         sconn->smb1.sessions.session_workgroup = smb_xstrdup(workgroup);
409 }
410
411 /****************************************************************************
412  In security=share mode we need to return the client workgroup, as that's
413   what Vista uses for the NTLMv2 calculation.
414 ****************************************************************************/
415
416 const char *get_session_workgroup(struct smbd_server_connection *sconn)
417 {
418         return sconn->smb1.sessions.session_workgroup;
419 }
420
421 /****************************************************************************
422  Check if a username is valid.
423 ****************************************************************************/
424
425 static bool user_ok(const char *user, int snum)
426 {
427         bool ret;
428
429         ret = True;
430
431         if (lp_invalid_users(snum)) {
432                 char **invalid = str_list_copy(talloc_tos(),
433                         lp_invalid_users(snum));
434                 if (invalid &&
435                     str_list_substitute(invalid, "%S", lp_servicename(snum))) {
436
437                         /* This is used in sec=share only, so no current user
438                          * around to pass to str_list_sub_basic() */
439
440                         if ( invalid && str_list_sub_basic(invalid, "", "") ) {
441                                 ret = !user_in_list(talloc_tos(), user,
442                                                     (const char **)invalid);
443                         }
444                 }
445                 TALLOC_FREE(invalid);
446         }
447
448         if (ret && lp_valid_users(snum)) {
449                 char **valid = str_list_copy(talloc_tos(),
450                         lp_valid_users(snum));
451                 if ( valid &&
452                      str_list_substitute(valid, "%S", lp_servicename(snum)) ) {
453
454                         /* This is used in sec=share only, so no current user
455                          * around to pass to str_list_sub_basic() */
456
457                         if ( valid && str_list_sub_basic(valid, "", "") ) {
458                                 ret = user_in_list(talloc_tos(), user,
459                                                    (const char **)valid);
460                         }
461                 }
462                 TALLOC_FREE(valid);
463         }
464
465         if (ret && lp_onlyuser(snum)) {
466                 char **user_list = str_list_make_v3(
467                         talloc_tos(), lp_username(snum), NULL);
468                 if (user_list &&
469                     str_list_substitute(user_list, "%S",
470                                         lp_servicename(snum))) {
471                         ret = user_in_list(talloc_tos(), user,
472                                            (const char **)user_list);
473                 }
474                 TALLOC_FREE(user_list);
475         }
476
477         return(ret);
478 }
479
480 /****************************************************************************
481  Validate a group username entry. Return the username or NULL.
482 ****************************************************************************/
483
484 static char *validate_group(struct smbd_server_connection *sconn,
485                             char *group, DATA_BLOB password,int snum)
486 {
487 #ifdef HAVE_NETGROUP
488         {
489                 char *host, *user, *domain;
490                 struct auth_context *actx = sconn->smb1.negprot.auth_context;
491                 bool enc = sconn->smb1.negprot.encrypted_passwords;
492                 setnetgrent(group);
493                 while (getnetgrent(&host, &user, &domain)) {
494                         if (user) {
495                                 if (user_ok(user, snum) &&
496                                     password_ok(actx, enc,
497                                                 get_session_workgroup(sconn),
498                                                 user,password)) {
499                                         endnetgrent();
500                                         return(user);
501                                 }
502                         }
503                 }
504                 endnetgrent();
505         }
506 #endif
507
508 #ifdef HAVE_GETGRENT
509         {
510                 struct group *gptr;
511                 struct auth_context *actx = sconn->smb1.negprot.auth_context;
512                 bool enc = sconn->smb1.negprot.encrypted_passwords;
513
514                 setgrent();
515                 while ((gptr = (struct group *)getgrent())) {
516                         if (strequal(gptr->gr_name,group))
517                                 break;
518                 }
519
520                 /*
521                  * As user_ok can recurse doing a getgrent(), we must
522                  * copy the member list onto the heap before
523                  * use. Bug pointed out by leon@eatworms.swmed.edu.
524                  */
525
526                 if (gptr) {
527                         char *member_list = NULL;
528                         size_t list_len = 0;
529                         char *member;
530                         int i;
531
532                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
533                                 list_len += strlen(gptr->gr_mem[i])+1;
534                         }
535                         list_len++;
536
537                         member_list = (char *)SMB_MALLOC(list_len);
538                         if (!member_list) {
539                                 endgrent();
540                                 return NULL;
541                         }
542
543                         *member_list = '\0';
544                         member = member_list;
545
546                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
547                                 size_t member_len = strlen(gptr->gr_mem[i])+1;
548
549                                 DEBUG(10,("validate_group: = gr_mem = "
550                                           "%s\n", gptr->gr_mem[i]));
551
552                                 safe_strcpy(member, gptr->gr_mem[i],
553                                         list_len - (member-member_list));
554                                 member += member_len;
555                         }
556
557                         endgrent();
558
559                         member = member_list;
560                         while (*member) {
561                                 if (user_ok(member,snum) &&
562                                     password_ok(actx, enc,
563                                                 get_session_workgroup(sconn),
564                                                 member,password)) {
565                                         char *name = talloc_strdup(talloc_tos(),
566                                                                 member);
567                                         SAFE_FREE(member_list);
568                                         return name;
569                                 }
570
571                                 DEBUG(10,("validate_group = member = %s\n",
572                                           member));
573
574                                 member += strlen(member) + 1;
575                         }
576
577                         SAFE_FREE(member_list);
578                 } else {
579                         endgrent();
580                         return NULL;
581                 }
582         }
583 #endif
584         return(NULL);
585 }
586
587 /****************************************************************************
588  Check for authority to login to a service with a given username/password.
589  Note this is *NOT* used when logging on using sessionsetup_and_X.
590 ****************************************************************************/
591
592 bool authorise_login(struct smbd_server_connection *sconn,
593                      int snum, fstring user, DATA_BLOB password,
594                      bool *guest)
595 {
596         bool ok = False;
597         struct auth_context *actx = sconn->smb1.negprot.auth_context;
598         bool enc = sconn->smb1.negprot.encrypted_passwords;
599
600 #ifdef DEBUG_PASSWORD
601         DEBUG(100,("authorise_login: checking authorisation on "
602                    "user=%s pass=%s\n", user,password.data));
603 #endif
604
605         *guest = False;
606
607         /* there are several possibilities:
608                 1) login as the given user with given password
609                 2) login as a previously registered username with the given
610                    password
611                 3) login as a session list username with the given password
612                 4) login as a previously validated user/password pair
613                 5) login as the "user =" user with given password
614                 6) login as the "user =" user with no password
615                    (guest connection)
616                 7) login as guest user with no password
617
618                 if the service is guest_only then steps 1 to 5 are skipped
619         */
620
621         /* now check the list of session users */
622         if (!ok) {
623                 char *auser;
624                 char *user_list = NULL;
625                 char *saveptr;
626
627                 if (sconn->smb1.sessions.session_userlist)
628                         user_list = SMB_STRDUP(sconn->smb1.sessions.session_userlist);
629                 else
630                         user_list = SMB_STRDUP("");
631
632                 if (!user_list)
633                         return(False);
634
635                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
636                      !ok && auser;
637                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
638                         fstring user2;
639                         fstrcpy(user2,auser);
640                         if (!user_ok(user2,snum))
641                                 continue;
642
643                         if (password_ok(actx, enc,
644                                         get_session_workgroup(sconn),
645                                         user2,password)) {
646                                 ok = True;
647                                 fstrcpy(user,user2);
648                                 DEBUG(3,("authorise_login: ACCEPTED: session "
649                                          "list username (%s) and given "
650                                          "password ok\n", user));
651                         }
652                 }
653
654                 SAFE_FREE(user_list);
655         }
656
657         /* check the user= fields and the given password */
658         if (!ok && lp_username(snum)) {
659                 TALLOC_CTX *ctx = talloc_tos();
660                 char *auser;
661                 char *user_list = talloc_strdup(ctx, lp_username(snum));
662                 char *saveptr;
663
664                 if (!user_list) {
665                         goto check_guest;
666                 }
667
668                 user_list = talloc_string_sub(ctx,
669                                 user_list,
670                                 "%S",
671                                 lp_servicename(snum));
672
673                 if (!user_list) {
674                         goto check_guest;
675                 }
676
677                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
678                      auser && !ok;
679                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
680                         if (*auser == '@') {
681                                 auser = validate_group(sconn,auser+1,
682                                                        password,snum);
683                                 if (auser) {
684                                         ok = True;
685                                         fstrcpy(user,auser);
686                                         DEBUG(3,("authorise_login: ACCEPTED: "
687                                                  "group username and given "
688                                                  "password ok (%s)\n", user));
689                                 }
690                         } else {
691                                 fstring user2;
692                                 fstrcpy(user2,auser);
693                                 if (user_ok(user2,snum) &&
694                                     password_ok(actx, enc,
695                                                 get_session_workgroup(sconn),
696                                                 user2,password)) {
697                                         ok = True;
698                                         fstrcpy(user,user2);
699                                         DEBUG(3,("authorise_login: ACCEPTED: "
700                                                  "user list username and "
701                                                  "given password ok (%s)\n",
702                                                  user));
703                                 }
704                         }
705                 }
706         }
707
708   check_guest:
709
710         /* check for a normal guest connection */
711         if (!ok && GUEST_OK(snum)) {
712                 struct passwd *guest_pw;
713                 fstring guestname;
714                 fstrcpy(guestname,lp_guestaccount());
715                 guest_pw = Get_Pwnam_alloc(talloc_tos(), guestname);
716                 if (guest_pw != NULL) {
717                         fstrcpy(user,guestname);
718                         ok = True;
719                         DEBUG(3,("authorise_login: ACCEPTED: guest account "
720                                  "and guest ok (%s)\n", user));
721                 } else {
722                         DEBUG(0,("authorise_login: Invalid guest account "
723                                  "%s??\n",guestname));
724                 }
725                 TALLOC_FREE(guest_pw);
726                 *guest = True;
727         }
728
729         if (ok && !user_ok(user, snum)) {
730                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
731                 ok = False;
732         }
733
734         return(ok);
735 }