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