source/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
  23 /* users from session setup */
  24 static char *session_userlist = NULL;
  25 /* workgroup from session setup. */
  26 static char *session_workgroup = NULL;
  27
  28 /* this holds info on user ids that are already validated for this VC */
  29 static user_struct *validated_users;
  30 static uint16_t next_vuid = VUID_OFFSET;
  31 static int num_validated_vuids;
  32
  33 enum server_allocated_state { SERVER_ALLOCATED_REQUIRED_YES,
  34                                 SERVER_ALLOCATED_REQUIRED_NO,
  35                                 SERVER_ALLOCATED_REQUIRED_ANY};
  36
  37 static user_struct *get_valid_user_struct_internal(uint16 vuid,
  38                         enum server_allocated_state server_allocated)
  39 {
  40         user_struct *usp;
  41         int count=0;
  42
  43         if (vuid == UID_FIELD_INVALID)
  44                 return NULL;
  45
  46         for (usp=validated_users;usp;usp=usp->next,count++) {
  47                 if (vuid == usp->vuid) {
  48                         switch (server_allocated) {
  49                                 case SERVER_ALLOCATED_REQUIRED_YES:
  50                                         if (usp->server_info == NULL) {
  51                                                 continue;
  52                                         }
  53                                         break;
  54                                 case SERVER_ALLOCATED_REQUIRED_NO:
  55                                         if (usp->server_info != NULL) {
  56                                                 continue;
  57                                         }
  58                                 case SERVER_ALLOCATED_REQUIRED_ANY:
  59                                         break;
  60                         }
  61                         if (count > 10) {
  62                                 DLIST_PROMOTE(validated_users, usp);
  63                         }
  64                         return usp;
  65                 }
  66         }
  67
  68         return NULL;
  69 }
  70
  71 /****************************************************************************
  72  Check if a uid has been validated, and return an pointer to the user_struct
  73  if it has. NULL if not. vuid is biased by an offset. This allows us to
  74  tell random client vuid's (normally zero) from valid vuids.
  75 ****************************************************************************/
  76
  77 user_struct *get_valid_user_struct(uint16 vuid)
  78 {
  79         return get_valid_user_struct_internal(vuid,
  80                         SERVER_ALLOCATED_REQUIRED_YES);
  81 }
  82
  83 bool is_partial_auth_vuid(uint16 vuid)
  84 {
  85         if (vuid == UID_FIELD_INVALID) {
  86                 return False;
  87         }
  88         return get_valid_user_struct_internal(vuid,
  89                         SERVER_ALLOCATED_REQUIRED_NO) ? True : False;
  90 }
  91
  92 /****************************************************************************
  93  Get the user struct of a partial NTLMSSP login
  94 ****************************************************************************/
  95
  96 user_struct *get_partial_auth_user_struct(uint16 vuid)
  97 {
  98         return get_valid_user_struct_internal(vuid,
  99                         SERVER_ALLOCATED_REQUIRED_NO);
 100 }
 101
 102 /****************************************************************************
 103  Invalidate a uid.
 104 ****************************************************************************/
 105
 106 void invalidate_vuid(uint16 vuid)
 107 {
 108         user_struct *vuser = NULL;
 109
 110         if (vuid == UID_FIELD_INVALID) {
 111                 return;
 112         }
 113
 114         vuser = get_valid_user_struct_internal(vuid,
 115                         SERVER_ALLOCATED_REQUIRED_ANY);
 116         if (vuser == NULL) {
 117                 return;
 118         }
 119
 120         session_yield(vuser);
 121
 122         data_blob_free(&vuser->session_key);
 123
 124         if (vuser->auth_ntlmssp_state) {
 125                 auth_ntlmssp_end(&vuser->auth_ntlmssp_state);
 126         }
 127
 128         DLIST_REMOVE(validated_users, vuser);
 129
 130         /* clear the vuid from the 'cache' on each connection, and
 131            from the vuid 'owner' of connections */
 132         conn_clear_vuid_cache(vuid);
 133
 134         TALLOC_FREE(vuser);
 135         num_validated_vuids--;
 136 }
 137
 138 /****************************************************************************
 139  Invalidate all vuid entries for this process.
 140 ****************************************************************************/
 141
 142 void invalidate_all_vuids(void)
 143 {
 144         user_struct *usp, *next=NULL;
 145
 146         for (usp=validated_users;usp;usp=next) {
 147                 next = usp->next;
 148                 invalidate_vuid(usp->vuid);
 149         }
 150 }
 151
 152 static void increment_next_vuid(uint16_t *vuid)
 153 {
 154         *vuid += 1;
 155
 156         /* Check for vuid wrap. */
 157         if (*vuid == UID_FIELD_INVALID) {
 158                 *vuid = VUID_OFFSET;
 159         }
 160 }
 161
 162 /****************************************************
 163  Create a new partial auth user struct.
 164 *****************************************************/
 165
 166 int register_initial_vuid(void)
 167 {
 168         user_struct *vuser;
 169
 170         /* Paranoia check. */
 171         if(lp_security() == SEC_SHARE) {
 172                 smb_panic("register_initial_vuid: "
 173                         "Tried to register uid in security=share");
 174         }
 175
 176         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 177         if (num_validated_vuids >= 0xFFFF-VUID_OFFSET) {
 178                 return UID_FIELD_INVALID;
 179         }
 180
 181         if((vuser = talloc_zero(NULL, user_struct)) == NULL) {
 182                 DEBUG(0,("register_initial_vuid: "
 183                                 "Failed to talloc users struct!\n"));
 184                 return UID_FIELD_INVALID;
 185         }
 186
 187         /* Allocate a free vuid. Yes this is a linear search... */
 188         while( get_valid_user_struct_internal(next_vuid,
 189                         SERVER_ALLOCATED_REQUIRED_ANY) != NULL ) {
 190                 increment_next_vuid(&next_vuid);
 191         }
 192
 193         DEBUG(10,("register_initial_vuid: allocated vuid = %u\n",
 194                 (unsigned int)next_vuid ));
 195
 196         vuser->vuid = next_vuid;
 197
 198         /*
 199          * This happens in an unfinished NTLMSSP session setup. We
 200          * need to allocate a vuid between the first and second calls
 201          * to NTLMSSP.
 202          */
 203         increment_next_vuid(&next_vuid);
 204         num_validated_vuids++;
 205
 206         DLIST_ADD(validated_users, vuser);
 207         return vuser->vuid;
 208 }
 209
 210 /**
 211  *  register that a valid login has been performed, establish 'session'.
 212  *  @param server_info The token returned from the authentication process.
 213  *   (now 'owned' by register_existing_vuid)
 214  *
 215  *  @param session_key The User session key for the login session (now also
 216  *  'owned' by register_existing_vuid)
 217  *
 218  *  @param respose_blob The NT challenge-response, if available.  (May be
 219  *  freed after this call)
 220  *
 221  *  @param smb_name The untranslated name of the user
 222  *
 223  *  @return Newly allocated vuid, biased by an offset. (This allows us to
 224  *   tell random client vuid's (normally zero) from valid vuids.)
 225  *
 226  */
 227
 228 int register_existing_vuid(uint16 vuid,
 229                         auth_serversupplied_info *server_info,
 230                         DATA_BLOB session_key,
 231                         DATA_BLOB response_blob,
 232                         const char *smb_name)
 233 {
 234         user_struct *vuser = get_partial_auth_user_struct(vuid);
 235         if (!vuser) {
 236                 goto fail;
 237         }
 238
 239         /* Use this to keep tabs on all our info from the authentication */
 240         vuser->server_info = server_info;
 241
 242         /* Ensure that the server_info will disappear with
 243          * the vuser it is now attached to */
 244
 245         talloc_steal(vuser, vuser->server_info);
 246
 247         /* the next functions should be done by a SID mapping system (SMS) as
 248          * the new real sam db won't have reference to unix uids or gids
 249          */
 250
 251         vuser->uid = server_info->uid;
 252         vuser->gid = server_info->gid;
 253
 254         vuser->n_groups = server_info->n_groups;
 255         if (vuser->n_groups) {
 256                 if (!(vuser->groups = (gid_t *)talloc_memdup(vuser,
 257                                         server_info->groups,
 258                                         sizeof(gid_t)*vuser->n_groups))) {
 259                         DEBUG(0,("register_existing_vuid: "
 260                                 "failed to talloc_memdup vuser->groups\n"));
 261                         goto fail;
 262                 }
 263         }
 264
 265         vuser->guest = server_info->guest;
 266         fstrcpy(vuser->user.unix_name, server_info->unix_name);
 267
 268         /* This is a potentially untrusted username */
 269         alpha_strcpy(vuser->user.smb_name, smb_name, ". _-$",
 270                 sizeof(vuser->user.smb_name));
 271
 272         fstrcpy(vuser->user.domain, pdb_get_domain(server_info->sam_account));
 273         fstrcpy(vuser->user.full_name,
 274         pdb_get_fullname(server_info->sam_account));
 275
 276         {
 277                 /* Keep the homedir handy */
 278                 const char *homedir =
 279                         pdb_get_homedir(server_info->sam_account);
 280                 const char *logon_script =
 281                         pdb_get_logon_script(server_info->sam_account);
 282
 283                 if (!IS_SAM_DEFAULT(server_info->sam_account,
 284                                         PDB_UNIXHOMEDIR)) {
 285                         const char *unix_homedir =
 286                                 pdb_get_unix_homedir(server_info->sam_account);
 287                         if (unix_homedir) {
 288                                 vuser->unix_homedir = unix_homedir;
 289                         }
 290                 } else {
 291                         struct passwd *passwd =
 292                                 getpwnam_alloc(vuser, vuser->user.unix_name);
 293                         if (passwd) {
 294                                 vuser->unix_homedir = passwd->pw_dir;
 295                                 /* Ensure that the unix_homedir now
 296                                  * belongs to vuser, so it goes away
 297                                  * with it, not with passwd below: */
 298                                 talloc_steal(vuser, vuser->unix_homedir);
 299                                 TALLOC_FREE(passwd);
 300                         }
 301                 }
 302
 303                 if (homedir) {
 304                         vuser->homedir = homedir;
 305                 }
 306                 if (logon_script) {
 307                         vuser->logon_script = logon_script;
 308                 }
 309         }
 310         vuser->session_key = session_key;
 311
 312         DEBUG(10,("register_existing_vuid: (%u,%u) %s %s %s guest=%d\n",
 313                         (unsigned int)vuser->uid,
 314                         (unsigned int)vuser->gid,
 315                         vuser->user.unix_name, vuser->user.smb_name,
 316                         vuser->user.domain, vuser->guest ));
 317
 318         DEBUG(3, ("register_existing_vuid: User name: %s\t"
 319                 "Real name: %s\n", vuser->user.unix_name,
 320                 vuser->user.full_name));
 321
 322         if (server_info->ptok) {
 323                 vuser->nt_user_token = dup_nt_token(vuser, server_info->ptok);
 324         } else {
 325                 DEBUG(1, ("register_existing_vuid: server_info does not "
 326                         "contain a user_token - cannot continue\n"));
 327                 goto fail;
 328         }
 329
 330         DEBUG(3,("register_existing_vuid: UNIX uid %d is UNIX user %s, "
 331                 "and will be vuid %u\n",
 332                 (int)vuser->uid,vuser->user.unix_name, vuser->vuid));
 333
 334         if (!session_claim(vuser)) {
 335                 DEBUG(1, ("register_existing_vuid: Failed to claim session "
 336                         "for vuid=%d\n",
 337                         vuser->vuid));
 338                 goto fail;
 339         }
 340
 341         /* Register a home dir service for this user if
 342         (a) This is not a guest connection,
 343         (b) we have a home directory defined
 344         (c) there s not an existing static share by that name
 345         If a share exists by this name (autoloaded or not) reuse it . */
 346
 347         vuser->homes_snum = -1;
 348         if ( (!vuser->guest) && vuser->unix_homedir && *(vuser->unix_homedir)) {
 349                 int servicenumber = lp_servicenumber(vuser->user.unix_name);
 350                 if ( servicenumber == -1 ) {
 351                         DEBUG(3, ("Adding homes service for user '%s' using "
 352                                 "home directory: '%s'\n",
 353                                 vuser->user.unix_name, vuser->unix_homedir));
 354                         vuser->homes_snum =
 355                                 add_home_service(vuser->user.unix_name,
 356                                                 vuser->user.unix_name,
 357                                                 vuser->unix_homedir);
 358                 } else {
 359                         DEBUG(3, ("Using static (or previously created) "
 360                                 "service for user '%s'; path = '%s'\n",
 361                                 vuser->user.unix_name,
 362                                 lp_pathname(servicenumber) ));
 363                         vuser->homes_snum = servicenumber;
 364                 }
 365         }
 366
 367         if (srv_is_signing_negotiated() && !vuser->guest &&
 368                         !srv_signing_started()) {
 369                 /* Try and turn on server signing on the first non-guest
 370                  * sessionsetup. */
 371                 srv_set_signing(vuser->session_key, response_blob);
 372         }
 373
 374         /* fill in the current_user_info struct */
 375         set_current_user_info( &vuser->user );
 376         return vuser->vuid;
 377
 378   fail:
 379
 380         if (vuser) {
 381                 invalidate_vuid(vuid);
 382         }
 383         return UID_FIELD_INVALID;
 384 }
 385
 386 /****************************************************************************
 387  Add a name to the session users list.
 388 ****************************************************************************/
 389
 390 void add_session_user(const char *user)
 391 {
 392         struct passwd *pw;
 393         char *tmp;
 394
 395         pw = Get_Pwnam_alloc(talloc_tos(), user);
 396
 397         if (pw == NULL) {
 398                 return;
 399         }
 400
 401         if (session_userlist == NULL) {
 402                 session_userlist = SMB_STRDUP(pw->pw_name);
 403                 goto done;
 404         }
 405
 406         if (in_list(pw->pw_name,session_userlist,False) ) {
 407                 goto done;
 408         }
 409
 410         if (strlen(session_userlist) > 128 * 1024) {
 411                 DEBUG(3,("add_session_user: session userlist already "
 412                          "too large.\n"));
 413                 goto done;
 414         }
 415
 416         if (asprintf(&tmp, "%s %s", session_userlist, pw->pw_name) == -1) {
 417                 DEBUG(3, ("asprintf failed\n"));
 418                 goto done;
 419         }
 420
 421         SAFE_FREE(session_userlist);
 422         session_userlist = tmp;
 423  done:
 424         TALLOC_FREE(pw);
 425 }
 426
 427 /****************************************************************************
 428  In security=share mode we need to store the client workgroup, as that's
 429   what Vista uses for the NTLMv2 calculation.
 430 ****************************************************************************/
 431
 432 void add_session_workgroup(const char *workgroup)
 433 {
 434         if (session_workgroup) {
 435                 SAFE_FREE(session_workgroup);
 436         }
 437         session_workgroup = smb_xstrdup(workgroup);
 438 }
 439
 440 /****************************************************************************
 441  In security=share mode we need to return the client workgroup, as that's
 442   what Vista uses for the NTLMv2 calculation.
 443 ****************************************************************************/
 444
 445 const char *get_session_workgroup(void)
 446 {
 447         return session_workgroup;
 448 }
 449
 450 /****************************************************************************
 451  Check if a user is in a netgroup user list. If at first we don't succeed,
 452  try lower case.
 453 ****************************************************************************/
 454
 455 bool user_in_netgroup(const char *user, const char *ngname)
 456 {
 457 #ifdef HAVE_NETGROUP
 458         static char *mydomain = NULL;
 459         fstring lowercase_user;
 460
 461         if (mydomain == NULL)
 462                 yp_get_default_domain(&mydomain);
 463
 464         if(mydomain == NULL) {
 465                 DEBUG(5,("Unable to get default yp domain, "
 466                         "let's try without specifying it\n"));
 467         }
 468
 469         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 470                 user, mydomain?mydomain:"(ANY)", ngname));
 471
 472         if (innetgr(ngname, NULL, user, mydomain)) {
 473                 DEBUG(5,("user_in_netgroup: Found\n"));
 474                 return (True);
 475         } else {
 476
 477                 /*
 478                  * Ok, innetgr is case sensitive. Try once more with lowercase
 479                  * just in case. Attempt to fix #703. JRA.
 480                  */
 481
 482                 fstrcpy(lowercase_user, user);
 483                 strlower_m(lowercase_user);
 484
 485                 DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 486                         lowercase_user, mydomain?mydomain:"(ANY)", ngname));
 487
 488                 if (innetgr(ngname, NULL, lowercase_user, mydomain)) {
 489                         DEBUG(5,("user_in_netgroup: Found\n"));
 490                         return (True);
 491                 }
 492         }
 493 #endif /* HAVE_NETGROUP */
 494         return False;
 495 }
 496
 497 /****************************************************************************
 498  Check if a user is in a user list - can check combinations of UNIX
 499  and netgroup lists.
 500 ****************************************************************************/
 501
 502 bool user_in_list(const char *user,const char **list)
 503 {
 504         if (!list || !*list)
 505                 return False;
 506
 507         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 508
 509         while (*list) {
 510
 511                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n",
 512                           user, *list));
 513
 514                 /*
 515                  * Check raw username.
 516                  */
 517                 if (strequal(user, *list))
 518                         return(True);
 519
 520                 /*
 521                  * Now check to see if any combination
 522                  * of UNIX and netgroups has been specified.
 523                  */
 524
 525                 if(**list == '@') {
 526                         /*
 527                          * Old behaviour. Check netgroup list
 528                          * followed by UNIX list.
 529                          */
 530                         if(user_in_netgroup(user, *list +1))
 531                                 return True;
 532                         if(user_in_group(user, *list +1))
 533                                 return True;
 534                 } else if (**list == '+') {
 535
 536                         if((*(*list +1)) == '&') {
 537                                 /*
 538                                  * Search UNIX list followed by netgroup.
 539                                  */
 540                                 if(user_in_group(user, *list +2))
 541                                         return True;
 542                                 if(user_in_netgroup(user, *list +2))
 543                                         return True;
 544
 545                         } else {
 546
 547                                 /*
 548                                  * Just search UNIX list.
 549                                  */
 550
 551                                 if(user_in_group(user, *list +1))
 552                                         return True;
 553                         }
 554
 555                 } else if (**list == '&') {
 556
 557                         if(*(*list +1) == '+') {
 558                                 /*
 559                                  * Search netgroup list followed by UNIX list.
 560                                  */
 561                                 if(user_in_netgroup(user, *list +2))
 562                                         return True;
 563                                 if(user_in_group(user, *list +2))
 564                                         return True;
 565                         } else {
 566                                 /*
 567                                  * Just search netgroup list.
 568                                  */
 569                                 if(user_in_netgroup(user, *list +1))
 570                                         return True;
 571                         }
 572                 }
 573
 574                 list++;
 575         }
 576         return(False);
 577 }
 578
 579 /****************************************************************************
 580  Check if a username is valid.
 581 ****************************************************************************/
 582
 583 static bool user_ok(const char *user, int snum)
 584 {
 585         char **valid, **invalid;
 586         bool ret;
 587
 588         valid = invalid = NULL;
 589         ret = True;
 590
 591         if (lp_invalid_users(snum)) {
 592                 str_list_copy(talloc_tos(), &invalid, lp_invalid_users(snum));
 593                 if (invalid &&
 594                     str_list_substitute(invalid, "%S", lp_servicename(snum))) {
 595
 596                         /* This is used in sec=share only, so no current user
 597                          * around to pass to str_list_sub_basic() */
 598
 599                         if ( invalid && str_list_sub_basic(invalid, "", "") ) {
 600                                 ret = !user_in_list(user,
 601                                                     (const char **)invalid);
 602                         }
 603                 }
 604         }
 605         TALLOC_FREE(invalid);
 606
 607         if (ret && lp_valid_users(snum)) {
 608                 str_list_copy(talloc_tos(), &valid, lp_valid_users(snum));
 609                 if ( valid &&
 610                      str_list_substitute(valid, "%S", lp_servicename(snum)) ) {
 611
 612                         /* This is used in sec=share only, so no current user
 613                          * around to pass to str_list_sub_basic() */
 614
 615                         if ( valid && str_list_sub_basic(valid, "", "") ) {
 616                                 ret = user_in_list(user, (const char **)valid);
 617                         }
 618                 }
 619         }
 620         TALLOC_FREE(valid);
 621
 622         if (ret && lp_onlyuser(snum)) {
 623                 char **user_list = str_list_make(
 624                         talloc_tos(), lp_username(snum), NULL);
 625                 if (user_list &&
 626                     str_list_substitute(user_list, "%S",
 627                                         lp_servicename(snum))) {
 628                         ret = user_in_list(user, (const char **)user_list);
 629                 }
 630                 TALLOC_FREE(user_list);
 631         }
 632
 633         return(ret);
 634 }
 635
 636 /****************************************************************************
 637  Validate a group username entry. Return the username or NULL.
 638 ****************************************************************************/
 639
 640 static char *validate_group(char *group, DATA_BLOB password,int snum)
 641 {
 642 #ifdef HAVE_NETGROUP
 643         {
 644                 char *host, *user, *domain;
 645                 setnetgrent(group);
 646                 while (getnetgrent(&host, &user, &domain)) {
 647                         if (user) {
 648                                 if (user_ok(user, snum) &&
 649                                     password_ok(user,password)) {
 650                                         endnetgrent();
 651                                         return(user);
 652                                 }
 653                         }
 654                 }
 655                 endnetgrent();
 656         }
 657 #endif
 658
 659 #ifdef HAVE_GETGRENT
 660         {
 661                 struct group *gptr;
 662                 setgrent();
 663                 while ((gptr = (struct group *)getgrent())) {
 664                         if (strequal(gptr->gr_name,group))
 665                                 break;
 666                 }
 667
 668                 /*
 669                  * As user_ok can recurse doing a getgrent(), we must
 670                  * copy the member list onto the heap before
 671                  * use. Bug pointed out by leon@eatworms.swmed.edu.
 672                  */
 673
 674                 if (gptr) {
 675                         char *member_list = NULL;
 676                         size_t list_len = 0;
 677                         char *member;
 678                         int i;
 679
 680                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 681                                 list_len += strlen(gptr->gr_mem[i])+1;
 682                         }
 683                         list_len++;
 684
 685                         member_list = (char *)SMB_MALLOC(list_len);
 686                         if (!member_list) {
 687                                 endgrent();
 688                                 return NULL;
 689                         }
 690
 691                         *member_list = '\0';
 692                         member = member_list;
 693
 694                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 695                                 size_t member_len = strlen(gptr->gr_mem[i])+1;
 696
 697                                 DEBUG(10,("validate_group: = gr_mem = "
 698                                           "%s\n", gptr->gr_mem[i]));
 699
 700                                 safe_strcpy(member, gptr->gr_mem[i],
 701                                         list_len - (member-member_list));
 702                                 member += member_len;
 703                         }
 704
 705                         endgrent();
 706
 707                         member = member_list;
 708                         while (*member) {
 709                                 if (user_ok(member,snum) &&
 710                                     password_ok(member,password)) {
 711                                         char *name = talloc_strdup(talloc_tos(),
 712                                                                 member);
 713                                         SAFE_FREE(member_list);
 714                                         return name;
 715                                 }
 716
 717                                 DEBUG(10,("validate_group = member = %s\n",
 718                                           member));
 719
 720                                 member += strlen(member) + 1;
 721                         }
 722
 723                         SAFE_FREE(member_list);
 724                 } else {
 725                         endgrent();
 726                         return NULL;
 727                 }
 728         }
 729 #endif
 730         return(NULL);
 731 }
 732
 733 /****************************************************************************
 734  Check for authority to login to a service with a given username/password.
 735  Note this is *NOT* used when logging on using sessionsetup_and_X.
 736 ****************************************************************************/
 737
 738 bool authorise_login(int snum, fstring user, DATA_BLOB password,
 739                      bool *guest)
 740 {
 741         bool ok = False;
 742
 743 #ifdef DEBUG_PASSWORD
 744         DEBUG(100,("authorise_login: checking authorisation on "
 745                    "user=%s pass=%s\n", user,password.data));
 746 #endif
 747
 748         *guest = False;
 749
 750         /* there are several possibilities:
 751                 1) login as the given user with given password
 752                 2) login as a previously registered username with the given
 753                    password
 754                 3) login as a session list username with the given password
 755                 4) login as a previously validated user/password pair
 756                 5) login as the "user =" user with given password
 757                 6) login as the "user =" user with no password
 758                    (guest connection)
 759                 7) login as guest user with no password
 760
 761                 if the service is guest_only then steps 1 to 5 are skipped
 762         */
 763
 764         /* now check the list of session users */
 765         if (!ok) {
 766                 char *auser;
 767                 char *user_list = NULL;
 768                 char *saveptr;
 769
 770                 if ( session_userlist )
 771                         user_list = SMB_STRDUP(session_userlist);
 772                 else
 773                         user_list = SMB_STRDUP("");
 774
 775                 if (!user_list)
 776                         return(False);
 777
 778                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
 779                      !ok && auser;
 780                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
 781                         fstring user2;
 782                         fstrcpy(user2,auser);
 783                         if (!user_ok(user2,snum))
 784                                 continue;
 785
 786                         if (password_ok(user2,password)) {
 787                                 ok = True;
 788                                 fstrcpy(user,user2);
 789                                 DEBUG(3,("authorise_login: ACCEPTED: session "
 790                                          "list username (%s) and given "
 791                                          "password ok\n", user));
 792                         }
 793                 }
 794
 795                 SAFE_FREE(user_list);
 796         }
 797
 798         /* check the user= fields and the given password */
 799         if (!ok && lp_username(snum)) {
 800                 TALLOC_CTX *ctx = talloc_tos();
 801                 char *auser;
 802                 char *user_list = talloc_strdup(ctx, lp_username(snum));
 803                 char *saveptr;
 804
 805                 if (!user_list) {
 806                         goto check_guest;
 807                 }
 808
 809                 user_list = talloc_string_sub(ctx,
 810                                 user_list,
 811                                 "%S",
 812                                 lp_servicename(snum));
 813
 814                 if (!user_list) {
 815                         goto check_guest;
 816                 }
 817
 818                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
 819                      auser && !ok;
 820                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
 821                         if (*auser == '@') {
 822                                 auser = validate_group(auser+1,password,snum);
 823                                 if (auser) {
 824                                         ok = True;
 825                                         fstrcpy(user,auser);
 826                                         DEBUG(3,("authorise_login: ACCEPTED: "
 827                                                  "group username and given "
 828                                                  "password ok (%s)\n", user));
 829                                 }
 830                         } else {
 831                                 fstring user2;
 832                                 fstrcpy(user2,auser);
 833                                 if (user_ok(user2,snum) &&
 834                                     password_ok(user2,password)) {
 835                                         ok = True;
 836                                         fstrcpy(user,user2);
 837                                         DEBUG(3,("authorise_login: ACCEPTED: "
 838                                                  "user list username and "
 839                                                  "given password ok (%s)\n",
 840                                                  user));
 841                                 }
 842                         }
 843                 }
 844         }
 845
 846   check_guest:
 847
 848         /* check for a normal guest connection */
 849         if (!ok && GUEST_OK(snum)) {
 850                 struct passwd *guest_pw;
 851                 fstring guestname;
 852                 fstrcpy(guestname,lp_guestaccount());
 853                 guest_pw = Get_Pwnam_alloc(talloc_tos(), guestname);
 854                 if (guest_pw != NULL) {
 855                         fstrcpy(user,guestname);
 856                         ok = True;
 857                         DEBUG(3,("authorise_login: ACCEPTED: guest account "
 858                                  "and guest ok (%s)\n", user));
 859                 } else {
 860                         DEBUG(0,("authorise_login: Invalid guest account "
 861                                  "%s??\n",guestname));
 862                 }
 863                 TALLOC_FREE(guest_pw);
 864                 *guest = True;
 865         }
 866
 867         if (ok && !user_ok(user, snum)) {
 868                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
 869                 ok = False;
 870         }
 871
 872         return(ok);
 873 }