import HEAD into svn+ssh://svn.samba.org/home/svn/samba/trunk
[metze/old/v3-2-winbind-ndr.git] / source / smbd / password.c
1 /* 
2    Unix SMB/CIFS implementation.
3    Password and authentication handling
4    Copyright (C) Andrew Tridgell 1992-1998
5    
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 2 of the License, or
9    (at your option) any later version.
10    
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15    
16    You should have received a copy of the GNU General Public License
17    along with this program; if not, write to the Free Software
18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #include "includes.h"
22
23 /* users from session setup */
24 static pstring session_users="";
25
26 /* this holds info on user ids that are already validated for this VC */
27 static user_struct *validated_users;
28 static int next_vuid = VUID_OFFSET;
29 static int num_validated_vuids;
30
31 extern userdom_struct current_user_info;
32
33
34 /****************************************************************************
35  Check if a uid has been validated, and return an pointer to the user_struct
36  if it has. NULL if not. vuid is biased by an offset. This allows us to
37  tell random client vuid's (normally zero) from valid vuids.
38 ****************************************************************************/
39
40 user_struct *get_valid_user_struct(uint16 vuid)
41 {
42         user_struct *usp;
43         int count=0;
44
45         if (vuid == UID_FIELD_INVALID)
46                 return NULL;
47
48         for (usp=validated_users;usp;usp=usp->next,count++) {
49                 if (vuid == usp->vuid) {
50                         if (count > 10) {
51                                 DLIST_PROMOTE(validated_users, usp);
52                         }
53                         return usp;
54                 }
55         }
56
57         return NULL;
58 }
59
60 /****************************************************************************
61  Invalidate a uid.
62 ****************************************************************************/
63
64 void invalidate_vuid(uint16 vuid)
65 {
66         user_struct *vuser = get_valid_user_struct(vuid);
67
68         if (vuser == NULL)
69                 return;
70         
71         SAFE_FREE(vuser->homedir);
72         SAFE_FREE(vuser->unix_homedir);
73         SAFE_FREE(vuser->logon_script);
74         
75         session_yield(vuser);
76         SAFE_FREE(vuser->session_keystr);
77
78         free_server_info(&vuser->server_info);
79
80         data_blob_free(&vuser->session_key);
81
82         DLIST_REMOVE(validated_users, vuser);
83
84         /* clear the vuid from the 'cache' on each connection, and
85            from the vuid 'owner' of connections */
86         conn_clear_vuid_cache(vuid);
87
88         SAFE_FREE(vuser->groups);
89         delete_nt_token(&vuser->nt_user_token);
90         destroy_privilege(&vuser->privs);
91         SAFE_FREE(vuser);
92         num_validated_vuids--;
93 }
94
95 /****************************************************************************
96  Invalidate all vuid entries for this process.
97 ****************************************************************************/
98
99 void invalidate_all_vuids(void)
100 {
101         user_struct *usp, *next=NULL;
102
103         for (usp=validated_users;usp;usp=next) {
104                 next = usp->next;
105                 
106                 invalidate_vuid(usp->vuid);
107         }
108 }
109
110 /**
111  *  register that a valid login has been performed, establish 'session'.
112  *  @param server_info The token returned from the authentication process. 
113  *   (now 'owned' by register_vuid)
114  *
115  *  @param session_key The User session key for the login session (now also 'owned' by register_vuid)
116  *
117  *  @param respose_blob The NT challenge-response, if available.  (May be freed after this call)
118  *
119  *  @param smb_name The untranslated name of the user
120  *
121  *  @return Newly allocated vuid, biased by an offset. (This allows us to
122  *   tell random client vuid's (normally zero) from valid vuids.)
123  *
124  */
125
126 int register_vuid(auth_serversupplied_info *server_info, DATA_BLOB session_key, DATA_BLOB response_blob, const char *smb_name)
127 {
128         user_struct *vuser = NULL;
129
130         /* Ensure no vuid gets registered in share level security. */
131         if(lp_security() == SEC_SHARE) {
132                 data_blob_free(&session_key);
133                 return UID_FIELD_INVALID;
134         }
135
136         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
137         if (num_validated_vuids >= 0xFFFF-VUID_OFFSET) {
138                 data_blob_free(&session_key);
139                 return UID_FIELD_INVALID;
140         }
141
142         if((vuser = (user_struct *)malloc( sizeof(user_struct) )) == NULL) {
143                 DEBUG(0,("Failed to malloc users struct!\n"));
144                 data_blob_free(&session_key);
145                 return UID_FIELD_INVALID;
146         }
147
148         ZERO_STRUCTP(vuser);
149
150         /* Allocate a free vuid. Yes this is a linear search... :-) */
151         while( get_valid_user_struct(next_vuid) != NULL ) {
152                 next_vuid++;
153                 /* Check for vuid wrap. */
154                 if (next_vuid == UID_FIELD_INVALID)
155                         next_vuid = VUID_OFFSET;
156         }
157
158         DEBUG(10,("register_vuid: allocated vuid = %u\n", (unsigned int)next_vuid ));
159
160         vuser->vuid = next_vuid;
161
162         /* the next functions should be done by a SID mapping system (SMS) as
163          * the new real sam db won't have reference to unix uids or gids
164          */
165         
166         vuser->uid = server_info->uid;
167         vuser->gid = server_info->gid;
168         
169         vuser->n_groups = server_info->n_groups;
170         if (vuser->n_groups) {
171                 if (!(vuser->groups = memdup(server_info->groups, sizeof(gid_t) * vuser->n_groups))) {
172                         DEBUG(0,("register_vuid: failed to memdup vuser->groups\n"));
173                         data_blob_free(&session_key);
174                         free(vuser);
175                         free_server_info(&server_info);
176                         return UID_FIELD_INVALID;
177                 }
178         }
179
180         vuser->guest = server_info->guest;
181         fstrcpy(vuser->user.unix_name, server_info->unix_name); 
182
183         /* This is a potentially untrusted username */
184         alpha_strcpy(vuser->user.smb_name, smb_name, ". _-$", sizeof(vuser->user.smb_name));
185
186         fstrcpy(vuser->user.domain, pdb_get_domain(server_info->sam_account));
187         fstrcpy(vuser->user.full_name, pdb_get_fullname(server_info->sam_account));
188
189         {
190                 /* Keep the homedir handy */
191                 const char *homedir = pdb_get_homedir(server_info->sam_account);
192                 const char *logon_script = pdb_get_logon_script(server_info->sam_account);
193
194                 if (!IS_SAM_DEFAULT(server_info->sam_account, PDB_UNIXHOMEDIR)) {
195                         const char *unix_homedir = pdb_get_unix_homedir(server_info->sam_account);
196                         if (unix_homedir) {
197                                 vuser->unix_homedir = smb_xstrdup(unix_homedir);
198                         }
199                 } else {
200                         struct passwd *passwd = getpwnam_alloc(vuser->user.unix_name);
201                         if (passwd) {
202                                 vuser->unix_homedir = smb_xstrdup(passwd->pw_dir);
203                                 passwd_free(&passwd);
204                         }
205                 }
206                 
207                 if (homedir) {
208                         vuser->homedir = smb_xstrdup(homedir);
209                 }
210                 if (logon_script) {
211                         vuser->logon_script = smb_xstrdup(logon_script);
212                 }
213         }
214
215         vuser->session_key = session_key;
216
217         DEBUG(10,("register_vuid: (%u,%u) %s %s %s guest=%d\n", 
218                   (unsigned int)vuser->uid, 
219                   (unsigned int)vuser->gid,
220                   vuser->user.unix_name, vuser->user.smb_name, vuser->user.domain, vuser->guest ));
221
222         DEBUG(3, ("User name: %s\tReal name: %s\n",vuser->user.unix_name,vuser->user.full_name));       
223
224         if (server_info->ptok) {
225                 vuser->nt_user_token = dup_nt_token(server_info->ptok);
226         } else {
227                 DEBUG(1, ("server_info does not contain a user_token - cannot continue\n"));
228                 free_server_info(&server_info);
229                 data_blob_free(&session_key);
230                 SAFE_FREE(vuser->homedir);
231                 SAFE_FREE(vuser->unix_homedir);
232                 SAFE_FREE(vuser->logon_script);
233
234                 SAFE_FREE(vuser);
235                 return UID_FIELD_INVALID;
236         }
237
238         if (server_info->privs) {
239                 init_privilege(&(vuser->privs));
240                 dup_priv_set(vuser->privs, server_info->privs);
241         }
242
243         /* use this to keep tabs on all our info from the authentication */
244         vuser->server_info = server_info;
245
246         DEBUG(3,("UNIX uid %d is UNIX user %s, and will be vuid %u\n",(int)vuser->uid,vuser->user.unix_name, vuser->vuid));
247
248         next_vuid++;
249         num_validated_vuids++;
250
251         DLIST_ADD(validated_users, vuser);
252
253         if (!session_claim(vuser)) {
254                 DEBUG(1,("Failed to claim session for vuid=%d\n", vuser->vuid));
255                 invalidate_vuid(vuser->vuid);
256                 return -1;
257         }
258
259         /* Register a home dir service for this user iff
260            (a) This is not a guest connection,
261            (b) we have a home directory defined, and
262            (c) there s not an existing static share by that name */
263
264         if ( (!vuser->guest) 
265                 && vuser->unix_homedir 
266                 && *(vuser->unix_homedir) 
267                 && (lp_servicenumber(vuser->user.unix_name) == -1) ) 
268         {
269                         DEBUG(3, ("Adding/updating homes service for user '%s' using home directory: '%s'\n", 
270                                 vuser->user.unix_name, vuser->unix_homedir));
271
272                         vuser->homes_snum = add_home_service(vuser->user.unix_name, 
273                                 vuser->user.unix_name, vuser->unix_homedir);
274         } else {
275                 vuser->homes_snum = -1;
276         }
277         
278         if (srv_is_signing_negotiated() && !vuser->guest && !srv_signing_started()) {
279                 /* Try and turn on server signing on the first non-guest sessionsetup. */
280                 srv_set_signing(vuser->session_key, response_blob);
281         }
282         
283         /* fill in the current_user_info struct */
284         set_current_user_info( &vuser->user );
285
286
287         return vuser->vuid;
288 }
289
290 /****************************************************************************
291  Add a name to the session users list.
292 ****************************************************************************/
293
294 void add_session_user(const char *user)
295 {
296         fstring suser;
297         struct passwd *passwd;
298
299         if (!(passwd = Get_Pwnam(user)))
300                 return;
301
302         fstrcpy(suser,passwd->pw_name);
303
304         if (suser && *suser && !in_list(suser,session_users,False)) {
305                 if (strlen(suser) + strlen(session_users) + 2 >= sizeof(pstring)) {
306                         DEBUG(1,("Too many session users??\n"));
307                 } else {
308                         pstrcat(session_users," ");
309                         pstrcat(session_users,suser);
310                 }
311         }
312 }
313
314 /****************************************************************************
315  Check if a username is valid.
316 ****************************************************************************/
317
318 BOOL user_ok(const char *user,int snum, gid_t *groups, size_t n_groups)
319 {
320         char **valid, **invalid;
321         BOOL ret;
322
323         valid = invalid = NULL;
324         ret = True;
325
326         if (lp_invalid_users(snum)) {
327                 str_list_copy(&invalid, lp_invalid_users(snum));
328                 if (invalid && str_list_substitute(invalid, "%S", lp_servicename(snum))) {
329                         if ( invalid && str_list_sub_basic(invalid, current_user_info.smb_name) ) {
330                                 ret = !user_in_list(user, (const char **)invalid, groups, n_groups);
331                         }
332                 }
333         }
334         if (invalid)
335                 str_list_free (&invalid);
336
337         if (ret && lp_valid_users(snum)) {
338                 str_list_copy(&valid, lp_valid_users(snum));
339                 if ( valid && str_list_substitute(valid, "%S", lp_servicename(snum)) ) {
340                         if ( valid && str_list_sub_basic(valid, current_user_info.smb_name) ) {
341                                 ret = user_in_list(user, (const char **)valid, groups, n_groups);
342                         }
343                 }
344         }
345         if (valid)
346                 str_list_free (&valid);
347
348         if (ret && lp_onlyuser(snum)) {
349                 char **user_list = str_list_make (lp_username(snum), NULL);
350                 if (user_list && str_list_substitute(user_list, "%S", lp_servicename(snum))) {
351                         ret = user_in_list(user, (const char **)user_list, groups, n_groups);
352                 }
353                 if (user_list) str_list_free (&user_list);
354         }
355
356         return(ret);
357 }
358
359 /****************************************************************************
360  Validate a group username entry. Return the username or NULL.
361 ****************************************************************************/
362
363 static char *validate_group(char *group, DATA_BLOB password,int snum)
364 {
365 #ifdef HAVE_NETGROUP
366         {
367                 char *host, *user, *domain;
368                 setnetgrent(group);
369                 while (getnetgrent(&host, &user, &domain)) {
370                         if (user) {
371                                 if (user_ok(user, snum, NULL, 0) && 
372                                     password_ok(user,password)) {
373                                         endnetgrent();
374                                         return(user);
375                                 }
376                         }
377                 }
378                 endnetgrent();
379         }
380 #endif
381   
382 #ifdef HAVE_GETGRENT
383         {
384                 struct group *gptr;
385                 setgrent();
386                 while ((gptr = (struct group *)getgrent())) {
387                         if (strequal(gptr->gr_name,group))
388                                 break;
389                 }
390
391                 /*
392                  * As user_ok can recurse doing a getgrent(), we must
393                  * copy the member list into a pstring on the stack before
394                  * use. Bug pointed out by leon@eatworms.swmed.edu.
395                  */
396
397                 if (gptr) {
398                         pstring member_list;
399                         char *member;
400                         size_t copied_len = 0;
401                         int i;
402
403                         *member_list = '\0';
404                         member = member_list;
405
406                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
407                                 size_t member_len = strlen(gptr->gr_mem[i]) + 1;
408                                 if( copied_len + member_len < sizeof(pstring)) { 
409
410                                         DEBUG(10,("validate_group: = gr_mem = %s\n", gptr->gr_mem[i]));
411
412                                         safe_strcpy(member, gptr->gr_mem[i], sizeof(pstring) - copied_len - 1);
413                                         copied_len += member_len;
414                                         member += copied_len;
415                                 } else {
416                                         *member = '\0';
417                                 }
418                         }
419
420                         endgrent();
421
422                         member = member_list;
423                         while (*member) {
424                                 static fstring name;
425                                 fstrcpy(name,member);
426                                 if (user_ok(name,snum, NULL, 0) &&
427                                     password_ok(name,password)) {
428                                         endgrent();
429                                         return(&name[0]);
430                                 }
431
432                                 DEBUG(10,("validate_group = member = %s\n", member));
433
434                                 member += strlen(member) + 1;
435                         }
436                 } else {
437                         endgrent();
438                         return NULL;
439                 }
440         }
441 #endif
442         return(NULL);
443 }
444
445 /****************************************************************************
446  Check for authority to login to a service with a given username/password.
447  Note this is *NOT* used when logging on using sessionsetup_and_X.
448 ****************************************************************************/
449
450 BOOL authorise_login(int snum, fstring user, DATA_BLOB password, 
451                      BOOL *guest)
452 {
453         BOOL ok = False;
454         
455 #if DEBUG_PASSWORD
456         DEBUG(100,("authorise_login: checking authorisation on user=%s pass=%s\n",
457                    user,password.data));
458 #endif
459
460         *guest = False;
461   
462         /* there are several possibilities:
463                 1) login as the given user with given password
464                 2) login as a previously registered username with the given password
465                 3) login as a session list username with the given password
466                 4) login as a previously validated user/password pair
467                 5) login as the "user =" user with given password
468                 6) login as the "user =" user with no password (guest connection)
469                 7) login as guest user with no password
470
471                 if the service is guest_only then steps 1 to 5 are skipped
472         */
473
474         /* now check the list of session users */
475         if (!ok) {
476                 char *auser;
477                 char *user_list = strdup(session_users);
478                 if (!user_list)
479                         return(False);
480                 
481                 for (auser=strtok(user_list,LIST_SEP); !ok && auser;
482                      auser = strtok(NULL,LIST_SEP)) {
483                         fstring user2;
484                         fstrcpy(user2,auser);
485                         if (!user_ok(user2,snum, NULL, 0))
486                                 continue;
487                         
488                         if (password_ok(user2,password)) {
489                                 ok = True;
490                                 fstrcpy(user,user2);
491                                 DEBUG(3,("authorise_login: ACCEPTED: session list username (%s) \
492 and given password ok\n", user));
493                         }
494                 }
495                 
496                 SAFE_FREE(user_list);
497         }
498         
499         /* check the user= fields and the given password */
500         if (!ok && lp_username(snum)) {
501                 char *auser;
502                 pstring user_list;
503                 pstrcpy(user_list,lp_username(snum));
504                 
505                 pstring_sub(user_list,"%S",lp_servicename(snum));
506                 
507                 for (auser=strtok(user_list,LIST_SEP); auser && !ok;
508                      auser = strtok(NULL,LIST_SEP)) {
509                         if (*auser == '@') {
510                                 auser = validate_group(auser+1,password,snum);
511                                 if (auser) {
512                                         ok = True;
513                                         fstrcpy(user,auser);
514                                         DEBUG(3,("authorise_login: ACCEPTED: group username \
515 and given password ok (%s)\n", user));
516                                 }
517                         } else {
518                                 fstring user2;
519                                 fstrcpy(user2,auser);
520                                 if (user_ok(user2,snum, NULL, 0) && password_ok(user2,password)) {
521                                         ok = True;
522                                         fstrcpy(user,user2);
523                                         DEBUG(3,("authorise_login: ACCEPTED: user list username \
524 and given password ok (%s)\n", user));
525                                 }
526                         }
527                 }
528         }
529
530         /* check for a normal guest connection */
531         if (!ok && GUEST_OK(snum)) {
532                 fstring guestname;
533                 fstrcpy(guestname,lp_guestaccount());
534                 if (Get_Pwnam(guestname)) {
535                         fstrcpy(user,guestname);
536                         ok = True;
537                         DEBUG(3,("authorise_login: ACCEPTED: guest account and guest ok (%s)\n",
538                                         user));
539                 } else {
540                         DEBUG(0,("authorise_login: Invalid guest account %s??\n",guestname));
541                 }
542                 *guest = True;
543         }
544
545         if (ok && !user_ok(user, snum, NULL, 0)) {
546                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
547                 ok = False;
548         }
549
550         return(ok);
551 }