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
  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 int 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         return (get_partial_auth_user_struct(vuid) != NULL);
  86 }
  87
  88 /****************************************************************************
  89  Get the user struct of a partial NTLMSSP login
  90 ****************************************************************************/
  91
  92 user_struct *get_partial_auth_user_struct(uint16 vuid)
  93 {
  94         return get_valid_user_struct_internal(vuid,
  95                         SERVER_ALLOCATED_REQUIRED_NO);
  96 }
  97
  98 /****************************************************************************
  99  Invalidate a uid.
 100 ****************************************************************************/
 101
 102 void invalidate_vuid(uint16 vuid)
 103 {
 104         user_struct *vuser = NULL;
 105
 106         if (vuid == UID_FIELD_INVALID) {
 107                 return;
 108         }
 109
 110         vuser = get_valid_user_struct_internal(vuid,
 111                         SERVER_ALLOCATED_REQUIRED_ANY);
 112         if (vuser == NULL) {
 113                 return;
 114         }
 115
 116         session_yield(vuser);
 117
 118         if (vuser->auth_ntlmssp_state) {
 119                 auth_ntlmssp_end(&vuser->auth_ntlmssp_state);
 120         }
 121
 122         DLIST_REMOVE(validated_users, vuser);
 123
 124         /* clear the vuid from the 'cache' on each connection, and
 125            from the vuid 'owner' of connections */
 126         conn_clear_vuid_caches(vuid);
 127
 128         TALLOC_FREE(vuser);
 129         num_validated_vuids--;
 130 }
 131
 132 /****************************************************************************
 133  Invalidate all vuid entries for this process.
 134 ****************************************************************************/
 135
 136 void invalidate_all_vuids(void)
 137 {
 138         while (validated_users != NULL) {
 139                 invalidate_vuid(validated_users->vuid);
 140         }
 141 }
 142
 143 /****************************************************
 144  Create a new partial auth user struct.
 145 *****************************************************/
 146
 147 int register_initial_vuid(void)
 148 {
 149         user_struct *vuser;
 150
 151         /* Paranoia check. */
 152         if(lp_security() == SEC_SHARE) {
 153                 smb_panic("register_initial_vuid: "
 154                         "Tried to register uid in security=share");
 155         }
 156
 157         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 158         if (num_validated_vuids >= 0xFFFF-VUID_OFFSET) {
 159                 return UID_FIELD_INVALID;
 160         }
 161
 162         if((vuser = talloc_zero(NULL, user_struct)) == NULL) {
 163                 DEBUG(0,("register_initial_vuid: "
 164                                 "Failed to talloc users struct!\n"));
 165                 return UID_FIELD_INVALID;
 166         }
 167
 168         /* Allocate a free vuid. Yes this is a linear search... */
 169         while( get_valid_user_struct_internal(next_vuid,
 170                         SERVER_ALLOCATED_REQUIRED_ANY) != NULL ) {
 171                 next_vuid++;
 172                 /* Check for vuid wrap. */
 173                 if (next_vuid == UID_FIELD_INVALID) {
 174                         next_vuid = VUID_OFFSET;
 175                 }
 176         }
 177
 178         DEBUG(10,("register_initial_vuid: allocated vuid = %u\n",
 179                 (unsigned int)next_vuid ));
 180
 181         vuser->vuid = next_vuid;
 182
 183         /*
 184          * This happens in an unfinished NTLMSSP session setup. We
 185          * need to allocate a vuid between the first and second calls
 186          * to NTLMSSP.
 187          */
 188         next_vuid++;
 189         num_validated_vuids++;
 190
 191         DLIST_ADD(validated_users, vuser);
 192         return vuser->vuid;
 193 }
 194
 195 static int register_homes_share(const char *username)
 196 {
 197         int result;
 198         struct passwd *pwd;
 199
 200         result = lp_servicenumber(username);
 201         if (result != -1) {
 202                 DEBUG(3, ("Using static (or previously created) service for "
 203                           "user '%s'; path = '%s'\n", username,
 204                           lp_pathname(result)));
 205                 return result;
 206         }
 207
 208         pwd = getpwnam_alloc(talloc_tos(), username);
 209
 210         if ((pwd == NULL) || (pwd->pw_dir[0] == '\0')) {
 211                 DEBUG(3, ("No home directory defined for user '%s'\n",
 212                           username));
 213                 TALLOC_FREE(pwd);
 214                 return -1;
 215         }
 216
 217         DEBUG(3, ("Adding homes service for user '%s' using home directory: "
 218                   "'%s'\n", username, pwd->pw_dir));
 219
 220         result = add_home_service(username, username, pwd->pw_dir);
 221
 222         TALLOC_FREE(pwd);
 223         return result;
 224 }
 225
 226 /**
 227  *  register that a valid login has been performed, establish 'session'.
 228  *  @param server_info The token returned from the authentication process.
 229  *   (now 'owned' by register_existing_vuid)
 230  *
 231  *  @param session_key The User session key for the login session (now also
 232  *  'owned' by register_existing_vuid)
 233  *
 234  *  @param respose_blob The NT challenge-response, if available.  (May be
 235  *  freed after this call)
 236  *
 237  *  @param smb_name The untranslated name of the user
 238  *
 239  *  @return Newly allocated vuid, biased by an offset. (This allows us to
 240  *   tell random client vuid's (normally zero) from valid vuids.)
 241  *
 242  */
 243
 244 int register_existing_vuid(uint16 vuid,
 245                         auth_serversupplied_info *server_info,
 246                         DATA_BLOB response_blob,
 247                         const char *smb_name)
 248 {
 249         fstring tmp;
 250         user_struct *vuser;
 251
 252         vuser = get_partial_auth_user_struct(vuid);
 253         if (!vuser) {
 254                 goto fail;
 255         }
 256
 257         /* Use this to keep tabs on all our info from the authentication */
 258         vuser->server_info = talloc_move(vuser, &server_info);
 259
 260         /* This is a potentially untrusted username */
 261         alpha_strcpy(tmp, smb_name, ". _-$", sizeof(tmp));
 262
 263         vuser->server_info->sanitized_username = talloc_strdup(
 264                 vuser->server_info, tmp);
 265
 266         DEBUG(10,("register_existing_vuid: (%u,%u) %s %s %s guest=%d\n",
 267                   (unsigned int)vuser->server_info->utok.uid,
 268                   (unsigned int)vuser->server_info->utok.gid,
 269                   vuser->server_info->unix_name,
 270                   vuser->server_info->sanitized_username,
 271                   pdb_get_domain(vuser->server_info->sam_account),
 272                   vuser->server_info->guest ));
 273
 274         DEBUG(3, ("register_existing_vuid: User name: %s\t"
 275                   "Real name: %s\n", vuser->server_info->unix_name,
 276                   pdb_get_fullname(vuser->server_info->sam_account)));
 277
 278         if (!vuser->server_info->ptok) {
 279                 DEBUG(1, ("register_existing_vuid: server_info does not "
 280                         "contain a user_token - cannot continue\n"));
 281                 goto fail;
 282         }
 283
 284         DEBUG(3,("register_existing_vuid: UNIX uid %d is UNIX user %s, "
 285                 "and will be vuid %u\n", (int)vuser->server_info->utok.uid,
 286                  vuser->server_info->unix_name, vuser->vuid));
 287
 288         next_vuid++;
 289         num_validated_vuids++;
 290
 291         if (!session_claim(vuser)) {
 292                 DEBUG(1, ("register_existing_vuid: Failed to claim session "
 293                         "for vuid=%d\n",
 294                         vuser->vuid));
 295                 goto fail;
 296         }
 297
 298         /* Register a home dir service for this user if
 299         (a) This is not a guest connection,
 300         (b) we have a home directory defined
 301         (c) there s not an existing static share by that name
 302         If a share exists by this name (autoloaded or not) reuse it . */
 303
 304         vuser->homes_snum = -1;
 305
 306         if (!vuser->server_info->guest) {
 307                 vuser->homes_snum = register_homes_share(
 308                         vuser->server_info->unix_name);
 309         }
 310
 311         if (srv_is_signing_negotiated() && !vuser->server_info->guest &&
 312                         !srv_signing_started()) {
 313                 /* Try and turn on server signing on the first non-guest
 314                  * sessionsetup. */
 315                 srv_set_signing(vuser->server_info->user_session_key, response_blob);
 316         }
 317
 318         /* fill in the current_user_info struct */
 319         set_current_user_info(
 320                 vuser->server_info->sanitized_username,
 321                 vuser->server_info->unix_name,
 322                 pdb_get_fullname(vuser->server_info->sam_account),
 323                 pdb_get_domain(vuser->server_info->sam_account));
 324
 325         return vuser->vuid;
 326
 327   fail:
 328
 329         if (vuser) {
 330                 invalidate_vuid(vuid);
 331         }
 332         return UID_FIELD_INVALID;
 333 }
 334
 335 /****************************************************************************
 336  Add a name to the session users list.
 337 ****************************************************************************/
 338
 339 void add_session_user(const char *user)
 340 {
 341         struct passwd *pw;
 342         char *tmp;
 343
 344         pw = Get_Pwnam_alloc(talloc_tos(), user);
 345
 346         if (pw == NULL) {
 347                 return;
 348         }
 349
 350         if (session_userlist == NULL) {
 351                 session_userlist = SMB_STRDUP(pw->pw_name);
 352                 goto done;
 353         }
 354
 355         if (in_list(pw->pw_name,session_userlist,False) ) {
 356                 goto done;
 357         }
 358
 359         if (strlen(session_userlist) > 128 * 1024) {
 360                 DEBUG(3,("add_session_user: session userlist already "
 361                          "too large.\n"));
 362                 goto done;
 363         }
 364
 365         if (asprintf(&tmp, "%s %s", session_userlist, pw->pw_name) == -1) {
 366                 DEBUG(3, ("asprintf failed\n"));
 367                 goto done;
 368         }
 369
 370         SAFE_FREE(session_userlist);
 371         session_userlist = tmp;
 372  done:
 373         TALLOC_FREE(pw);
 374 }
 375
 376 /****************************************************************************
 377  In security=share mode we need to store the client workgroup, as that's
 378   what Vista uses for the NTLMv2 calculation.
 379 ****************************************************************************/
 380
 381 void add_session_workgroup(const char *workgroup)
 382 {
 383         if (session_workgroup) {
 384                 SAFE_FREE(session_workgroup);
 385         }
 386         session_workgroup = smb_xstrdup(workgroup);
 387 }
 388
 389 /****************************************************************************
 390  In security=share mode we need to return the client workgroup, as that's
 391   what Vista uses for the NTLMv2 calculation.
 392 ****************************************************************************/
 393
 394 const char *get_session_workgroup(void)
 395 {
 396         return session_workgroup;
 397 }
 398
 399 /****************************************************************************
 400  Check if a user is in a netgroup user list. If at first we don't succeed,
 401  try lower case.
 402 ****************************************************************************/
 403
 404 bool user_in_netgroup(const char *user, const char *ngname)
 405 {
 406 #ifdef HAVE_NETGROUP
 407         static char *mydomain = NULL;
 408         fstring lowercase_user;
 409
 410         if (mydomain == NULL)
 411                 yp_get_default_domain(&mydomain);
 412
 413         if(mydomain == NULL) {
 414                 DEBUG(5,("Unable to get default yp domain, "
 415                         "let's try without specifying it\n"));
 416         }
 417
 418         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 419                 user, mydomain?mydomain:"(ANY)", ngname));
 420
 421         if (innetgr(ngname, NULL, user, mydomain)) {
 422                 DEBUG(5,("user_in_netgroup: Found\n"));
 423                 return (True);
 424         } else {
 425
 426                 /*
 427                  * Ok, innetgr is case sensitive. Try once more with lowercase
 428                  * just in case. Attempt to fix #703. JRA.
 429                  */
 430
 431                 fstrcpy(lowercase_user, user);
 432                 strlower_m(lowercase_user);
 433
 434                 DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 435                         lowercase_user, mydomain?mydomain:"(ANY)", ngname));
 436
 437                 if (innetgr(ngname, NULL, lowercase_user, mydomain)) {
 438                         DEBUG(5,("user_in_netgroup: Found\n"));
 439                         return (True);
 440                 }
 441         }
 442 #endif /* HAVE_NETGROUP */
 443         return False;
 444 }
 445
 446 /****************************************************************************
 447  Check if a user is in a user list - can check combinations of UNIX
 448  and netgroup lists.
 449 ****************************************************************************/
 450
 451 bool user_in_list(const char *user,const char **list)
 452 {
 453         if (!list || !*list)
 454                 return False;
 455
 456         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 457
 458         while (*list) {
 459
 460                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n",
 461                           user, *list));
 462
 463                 /*
 464                  * Check raw username.
 465                  */
 466                 if (strequal(user, *list))
 467                         return(True);
 468
 469                 /*
 470                  * Now check to see if any combination
 471                  * of UNIX and netgroups has been specified.
 472                  */
 473
 474                 if(**list == '@') {
 475                         /*
 476                          * Old behaviour. Check netgroup list
 477                          * followed by UNIX list.
 478                          */
 479                         if(user_in_netgroup(user, *list +1))
 480                                 return True;
 481                         if(user_in_group(user, *list +1))
 482                                 return True;
 483                 } else if (**list == '+') {
 484
 485                         if((*(*list +1)) == '&') {
 486                                 /*
 487                                  * Search UNIX list followed by netgroup.
 488                                  */
 489                                 if(user_in_group(user, *list +2))
 490                                         return True;
 491                                 if(user_in_netgroup(user, *list +2))
 492                                         return True;
 493
 494                         } else {
 495
 496                                 /*
 497                                  * Just search UNIX list.
 498                                  */
 499
 500                                 if(user_in_group(user, *list +1))
 501                                         return True;
 502                         }
 503
 504                 } else if (**list == '&') {
 505
 506                         if(*(*list +1) == '+') {
 507                                 /*
 508                                  * Search netgroup list followed by UNIX list.
 509                                  */
 510                                 if(user_in_netgroup(user, *list +2))
 511                                         return True;
 512                                 if(user_in_group(user, *list +2))
 513                                         return True;
 514                         } else {
 515                                 /*
 516                                  * Just search netgroup list.
 517                                  */
 518                                 if(user_in_netgroup(user, *list +1))
 519                                         return True;
 520                         }
 521                 }
 522
 523                 list++;
 524         }
 525         return(False);
 526 }
 527
 528 /****************************************************************************
 529  Check if a username is valid.
 530 ****************************************************************************/
 531
 532 static bool user_ok(const char *user, int snum)
 533 {
 534         char **valid, **invalid;
 535         bool ret;
 536
 537         valid = invalid = NULL;
 538         ret = True;
 539
 540         if (lp_invalid_users(snum)) {
 541                 invalid = str_list_copy(talloc_tos(), lp_invalid_users(snum));
 542                 if (invalid &&
 543                     str_list_substitute(invalid, "%S", lp_servicename(snum))) {
 544
 545                         /* This is used in sec=share only, so no current user
 546                          * around to pass to str_list_sub_basic() */
 547
 548                         if ( invalid && str_list_sub_basic(invalid, "", "") ) {
 549                                 ret = !user_in_list(user,
 550                                                     (const char **)invalid);
 551                         }
 552                 }
 553         }
 554         TALLOC_FREE(invalid);
 555
 556         if (ret && lp_valid_users(snum)) {
 557                 valid = str_list_copy(talloc_tos(), lp_valid_users(snum));
 558                 if ( valid &&
 559                      str_list_substitute(valid, "%S", lp_servicename(snum)) ) {
 560
 561                         /* This is used in sec=share only, so no current user
 562                          * around to pass to str_list_sub_basic() */
 563
 564                         if ( valid && str_list_sub_basic(valid, "", "") ) {
 565                                 ret = user_in_list(user, (const char **)valid);
 566                         }
 567                 }
 568         }
 569         TALLOC_FREE(valid);
 570
 571         if (ret && lp_onlyuser(snum)) {
 572                 char **user_list = str_list_make_v3(
 573                         talloc_tos(), lp_username(snum), NULL);
 574                 if (user_list &&
 575                     str_list_substitute(user_list, "%S",
 576                                         lp_servicename(snum))) {
 577                         ret = user_in_list(user, (const char **)user_list);
 578                 }
 579                 TALLOC_FREE(user_list);
 580         }
 581
 582         return(ret);
 583 }
 584
 585 /****************************************************************************
 586  Validate a group username entry. Return the username or NULL.
 587 ****************************************************************************/
 588
 589 static char *validate_group(char *group, DATA_BLOB password,int snum)
 590 {
 591 #ifdef HAVE_NETGROUP
 592         {
 593                 char *host, *user, *domain;
 594                 setnetgrent(group);
 595                 while (getnetgrent(&host, &user, &domain)) {
 596                         if (user) {
 597                                 if (user_ok(user, snum) &&
 598                                     password_ok(user,password)) {
 599                                         endnetgrent();
 600                                         return(user);
 601                                 }
 602                         }
 603                 }
 604                 endnetgrent();
 605         }
 606 #endif
 607
 608 #ifdef HAVE_GETGRENT
 609         {
 610                 struct group *gptr;
 611                 setgrent();
 612                 while ((gptr = (struct group *)getgrent())) {
 613                         if (strequal(gptr->gr_name,group))
 614                                 break;
 615                 }
 616
 617                 /*
 618                  * As user_ok can recurse doing a getgrent(), we must
 619                  * copy the member list onto the heap before
 620                  * use. Bug pointed out by leon@eatworms.swmed.edu.
 621                  */
 622
 623                 if (gptr) {
 624                         char *member_list = NULL;
 625                         size_t list_len = 0;
 626                         char *member;
 627                         int i;
 628
 629                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 630                                 list_len += strlen(gptr->gr_mem[i])+1;
 631                         }
 632                         list_len++;
 633
 634                         member_list = (char *)SMB_MALLOC(list_len);
 635                         if (!member_list) {
 636                                 endgrent();
 637                                 return NULL;
 638                         }
 639
 640                         *member_list = '\0';
 641                         member = member_list;
 642
 643                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 644                                 size_t member_len = strlen(gptr->gr_mem[i])+1;
 645
 646                                 DEBUG(10,("validate_group: = gr_mem = "
 647                                           "%s\n", gptr->gr_mem[i]));
 648
 649                                 safe_strcpy(member, gptr->gr_mem[i],
 650                                         list_len - (member-member_list));
 651                                 member += member_len;
 652                         }
 653
 654                         endgrent();
 655
 656                         member = member_list;
 657                         while (*member) {
 658                                 if (user_ok(member,snum) &&
 659                                     password_ok(member,password)) {
 660                                         char *name = talloc_strdup(talloc_tos(),
 661                                                                 member);
 662                                         SAFE_FREE(member_list);
 663                                         return name;
 664                                 }
 665
 666                                 DEBUG(10,("validate_group = member = %s\n",
 667                                           member));
 668
 669                                 member += strlen(member) + 1;
 670                         }
 671
 672                         SAFE_FREE(member_list);
 673                 } else {
 674                         endgrent();
 675                         return NULL;
 676                 }
 677         }
 678 #endif
 679         return(NULL);
 680 }
 681
 682 /****************************************************************************
 683  Check for authority to login to a service with a given username/password.
 684  Note this is *NOT* used when logging on using sessionsetup_and_X.
 685 ****************************************************************************/
 686
 687 bool authorise_login(int snum, fstring user, DATA_BLOB password,
 688                      bool *guest)
 689 {
 690         bool ok = False;
 691
 692 #ifdef DEBUG_PASSWORD
 693         DEBUG(100,("authorise_login: checking authorisation on "
 694                    "user=%s pass=%s\n", user,password.data));
 695 #endif
 696
 697         *guest = False;
 698
 699         /* there are several possibilities:
 700                 1) login as the given user with given password
 701                 2) login as a previously registered username with the given
 702                    password
 703                 3) login as a session list username with the given password
 704                 4) login as a previously validated user/password pair
 705                 5) login as the "user =" user with given password
 706                 6) login as the "user =" user with no password
 707                    (guest connection)
 708                 7) login as guest user with no password
 709
 710                 if the service is guest_only then steps 1 to 5 are skipped
 711         */
 712
 713         /* now check the list of session users */
 714         if (!ok) {
 715                 char *auser;
 716                 char *user_list = NULL;
 717                 char *saveptr;
 718
 719                 if ( session_userlist )
 720                         user_list = SMB_STRDUP(session_userlist);
 721                 else
 722                         user_list = SMB_STRDUP("");
 723
 724                 if (!user_list)
 725                         return(False);
 726
 727                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
 728                      !ok && auser;
 729                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
 730                         fstring user2;
 731                         fstrcpy(user2,auser);
 732                         if (!user_ok(user2,snum))
 733                                 continue;
 734
 735                         if (password_ok(user2,password)) {
 736                                 ok = True;
 737                                 fstrcpy(user,user2);
 738                                 DEBUG(3,("authorise_login: ACCEPTED: session "
 739                                          "list username (%s) and given "
 740                                          "password ok\n", user));
 741                         }
 742                 }
 743
 744                 SAFE_FREE(user_list);
 745         }
 746
 747         /* check the user= fields and the given password */
 748         if (!ok && lp_username(snum)) {
 749                 TALLOC_CTX *ctx = talloc_tos();
 750                 char *auser;
 751                 char *user_list = talloc_strdup(ctx, lp_username(snum));
 752                 char *saveptr;
 753
 754                 if (!user_list) {
 755                         goto check_guest;
 756                 }
 757
 758                 user_list = talloc_string_sub(ctx,
 759                                 user_list,
 760                                 "%S",
 761                                 lp_servicename(snum));
 762
 763                 if (!user_list) {
 764                         goto check_guest;
 765                 }
 766
 767                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
 768                      auser && !ok;
 769                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
 770                         if (*auser == '@') {
 771                                 auser = validate_group(auser+1,password,snum);
 772                                 if (auser) {
 773                                         ok = True;
 774                                         fstrcpy(user,auser);
 775                                         DEBUG(3,("authorise_login: ACCEPTED: "
 776                                                  "group username and given "
 777                                                  "password ok (%s)\n", user));
 778                                 }
 779                         } else {
 780                                 fstring user2;
 781                                 fstrcpy(user2,auser);
 782                                 if (user_ok(user2,snum) &&
 783                                     password_ok(user2,password)) {
 784                                         ok = True;
 785                                         fstrcpy(user,user2);
 786                                         DEBUG(3,("authorise_login: ACCEPTED: "
 787                                                  "user list username and "
 788                                                  "given password ok (%s)\n",
 789                                                  user));
 790                                 }
 791                         }
 792                 }
 793         }
 794
 795   check_guest:
 796
 797         /* check for a normal guest connection */
 798         if (!ok && GUEST_OK(snum)) {
 799                 struct passwd *guest_pw;
 800                 fstring guestname;
 801                 fstrcpy(guestname,lp_guestaccount());
 802                 guest_pw = Get_Pwnam_alloc(talloc_tos(), guestname);
 803                 if (guest_pw != NULL) {
 804                         fstrcpy(user,guestname);
 805                         ok = True;
 806                         DEBUG(3,("authorise_login: ACCEPTED: guest account "
 807                                  "and guest ok (%s)\n", user));
 808                 } else {
 809                         DEBUG(0,("authorise_login: Invalid guest account "
 810                                  "%s??\n",guestname));
 811                 }
 812                 TALLOC_FREE(guest_pw);
 813                 *guest = True;
 814         }
 815
 816         if (ok && !user_ok(user, snum)) {
 817                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
 818                 ok = False;
 819         }
 820
 821         return(ok);
 822 }