source3/smbd/password.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Password and authentication handling
   4    Copyright (C) Andrew Tridgell 1992-1998
   5    Copyright (C) Jeremy Allison 2007.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "smbd/globals.h"
  23
  24 enum server_allocated_state { SERVER_ALLOCATED_REQUIRED_YES,
  25                                 SERVER_ALLOCATED_REQUIRED_NO,
  26                                 SERVER_ALLOCATED_REQUIRED_ANY};
  27
  28 static user_struct *get_valid_user_struct_internal(
  29                         struct smbd_server_connection *sconn,
  30                         uint16 vuid,
  31                         enum server_allocated_state server_allocated)
  32 {
  33         user_struct *usp;
  34         int count=0;
  35
  36         if (vuid == UID_FIELD_INVALID)
  37                 return NULL;
  38
  39         usp=sconn->smb1.sessions.validated_users;
  40         for (;usp;usp=usp->next,count++) {
  41                 if (vuid == usp->vuid) {
  42                         switch (server_allocated) {
  43                                 case SERVER_ALLOCATED_REQUIRED_YES:
  44                                         if (usp->server_info == NULL) {
  45                                                 continue;
  46                                         }
  47                                         break;
  48                                 case SERVER_ALLOCATED_REQUIRED_NO:
  49                                         if (usp->server_info != NULL) {
  50                                                 continue;
  51                                         }
  52                                 case SERVER_ALLOCATED_REQUIRED_ANY:
  53                                         break;
  54                         }
  55                         if (count > 10) {
  56                                 DLIST_PROMOTE(sconn->smb1.sessions.validated_users,
  57                                               usp);
  58                         }
  59                         return usp;
  60                 }
  61         }
  62
  63         return NULL;
  64 }
  65
  66 /****************************************************************************
  67  Check if a uid has been validated, and return an pointer to the user_struct
  68  if it has. NULL if not. vuid is biased by an offset. This allows us to
  69  tell random client vuid's (normally zero) from valid vuids.
  70 ****************************************************************************/
  71
  72 user_struct *get_valid_user_struct(struct smbd_server_connection *sconn,
  73                                    uint16 vuid)
  74 {
  75         return get_valid_user_struct_internal(sconn, vuid,
  76                         SERVER_ALLOCATED_REQUIRED_YES);
  77 }
  78
  79 bool is_partial_auth_vuid(struct smbd_server_connection *sconn, uint16 vuid)
  80 {
  81         return (get_partial_auth_user_struct(sconn, vuid) != NULL);
  82 }
  83
  84 /****************************************************************************
  85  Get the user struct of a partial NTLMSSP login
  86 ****************************************************************************/
  87
  88 user_struct *get_partial_auth_user_struct(struct smbd_server_connection *sconn,
  89                                           uint16 vuid)
  90 {
  91         return get_valid_user_struct_internal(sconn, vuid,
  92                         SERVER_ALLOCATED_REQUIRED_NO);
  93 }
  94
  95 /****************************************************************************
  96  Invalidate a uid.
  97 ****************************************************************************/
  98
  99 void invalidate_vuid(struct smbd_server_connection *sconn, uint16 vuid)
 100 {
 101         user_struct *vuser = NULL;
 102
 103         vuser = get_valid_user_struct_internal(sconn, vuid,
 104                         SERVER_ALLOCATED_REQUIRED_ANY);
 105         if (vuser == NULL) {
 106                 return;
 107         }
 108
 109         session_yield(vuser);
 110
 111         if (vuser->auth_ntlmssp_state) {
 112                 auth_ntlmssp_end(&vuser->auth_ntlmssp_state);
 113         }
 114
 115         DLIST_REMOVE(sconn->smb1.sessions.validated_users, vuser);
 116
 117         /* clear the vuid from the 'cache' on each connection, and
 118            from the vuid 'owner' of connections */
 119         conn_clear_vuid_caches(sconn, vuid);
 120
 121         TALLOC_FREE(vuser);
 122         sconn->smb1.sessions.num_validated_vuids--;
 123 }
 124
 125 /****************************************************************************
 126  Invalidate all vuid entries for this process.
 127 ****************************************************************************/
 128
 129 void invalidate_all_vuids(struct smbd_server_connection *sconn)
 130 {
 131         if (sconn->allow_smb2) {
 132                 return;
 133         }
 134
 135         while (sconn->smb1.sessions.validated_users != NULL) {
 136                 invalidate_vuid(sconn,
 137                                 sconn->smb1.sessions.validated_users->vuid);
 138         }
 139 }
 140
 141 static void increment_next_vuid(uint16_t *vuid)
 142 {
 143         *vuid += 1;
 144
 145         /* Check for vuid wrap. */
 146         if (*vuid == UID_FIELD_INVALID) {
 147                 *vuid = VUID_OFFSET;
 148         }
 149 }
 150
 151 /****************************************************
 152  Create a new partial auth user struct.
 153 *****************************************************/
 154
 155 int register_initial_vuid(struct smbd_server_connection *sconn)
 156 {
 157         user_struct *vuser;
 158
 159         /* Paranoia check. */
 160         if(lp_security() == SEC_SHARE) {
 161                 smb_panic("register_initial_vuid: "
 162                         "Tried to register uid in security=share");
 163         }
 164
 165         /* Limit allowed vuids to 16bits - VUID_OFFSET. */
 166         if (sconn->smb1.sessions.num_validated_vuids >= 0xFFFF-VUID_OFFSET) {
 167                 return UID_FIELD_INVALID;
 168         }
 169
 170         if((vuser = talloc_zero(NULL, user_struct)) == NULL) {
 171                 DEBUG(0,("register_initial_vuid: "
 172                                 "Failed to talloc users struct!\n"));
 173                 return UID_FIELD_INVALID;
 174         }
 175
 176         /* Allocate a free vuid. Yes this is a linear search... */
 177         while( get_valid_user_struct_internal(sconn,
 178                         sconn->smb1.sessions.next_vuid,
 179                         SERVER_ALLOCATED_REQUIRED_ANY) != NULL ) {
 180                 increment_next_vuid(&sconn->smb1.sessions.next_vuid);
 181         }
 182
 183         DEBUG(10,("register_initial_vuid: allocated vuid = %u\n",
 184                 (unsigned int)sconn->smb1.sessions.next_vuid ));
 185
 186         vuser->vuid = sconn->smb1.sessions.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         increment_next_vuid(&sconn->smb1.sessions.next_vuid);
 194         sconn->smb1.sessions.num_validated_vuids++;
 195
 196         DLIST_ADD(sconn->smb1.sessions.validated_users, vuser);
 197         return vuser->vuid;
 198 }
 199
 200 int register_homes_share(const char *username)
 201 {
 202         int result;
 203         struct passwd *pwd;
 204
 205         result = lp_servicenumber(username);
 206         if (result != -1) {
 207                 DEBUG(3, ("Using static (or previously created) service for "
 208                           "user '%s'; path = '%s'\n", username,
 209                           lp_pathname(result)));
 210                 return result;
 211         }
 212
 213         pwd = getpwnam_alloc(talloc_tos(), username);
 214
 215         if ((pwd == NULL) || (pwd->pw_dir[0] == '\0')) {
 216                 DEBUG(3, ("No home directory defined for user '%s'\n",
 217                           username));
 218                 TALLOC_FREE(pwd);
 219                 return -1;
 220         }
 221
 222         DEBUG(3, ("Adding homes service for user '%s' using home directory: "
 223                   "'%s'\n", username, pwd->pw_dir));
 224
 225         result = add_home_service(username, username, pwd->pw_dir);
 226
 227         TALLOC_FREE(pwd);
 228         return result;
 229 }
 230
 231 /**
 232  *  register that a valid login has been performed, establish 'session'.
 233  *  @param server_info The token returned from the authentication process.
 234  *   (now 'owned' by register_existing_vuid)
 235  *
 236  *  @param session_key The User session key for the login session (now also
 237  *  'owned' by register_existing_vuid)
 238  *
 239  *  @param respose_blob The NT challenge-response, if available.  (May be
 240  *  freed after this call)
 241  *
 242  *  @param smb_name The untranslated name of the user
 243  *
 244  *  @return Newly allocated vuid, biased by an offset. (This allows us to
 245  *   tell random client vuid's (normally zero) from valid vuids.)
 246  *
 247  */
 248
 249 int register_existing_vuid(struct smbd_server_connection *sconn,
 250                         uint16 vuid,
 251                         struct auth_serversupplied_info *server_info,
 252                         DATA_BLOB response_blob,
 253                         const char *smb_name)
 254 {
 255         fstring tmp;
 256         user_struct *vuser;
 257
 258         vuser = get_partial_auth_user_struct(sconn, vuid);
 259         if (!vuser) {
 260                 goto fail;
 261         }
 262
 263         /* Use this to keep tabs on all our info from the authentication */
 264         vuser->server_info = talloc_move(vuser, &server_info);
 265
 266         /* This is a potentially untrusted username */
 267         alpha_strcpy(tmp, smb_name, ". _-$", sizeof(tmp));
 268
 269         vuser->server_info->sanitized_username = talloc_strdup(
 270                 vuser->server_info, tmp);
 271
 272         DEBUG(10,("register_existing_vuid: (%u,%u) %s %s %s guest=%d\n",
 273                   (unsigned int)vuser->server_info->utok.uid,
 274                   (unsigned int)vuser->server_info->utok.gid,
 275                   vuser->server_info->unix_name,
 276                   vuser->server_info->sanitized_username,
 277                   vuser->server_info->info3->base.domain.string,
 278                   vuser->server_info->guest ));
 279
 280         DEBUG(3, ("register_existing_vuid: User name: %s\t"
 281                   "Real name: %s\n", vuser->server_info->unix_name,
 282                   vuser->server_info->info3->base.full_name.string));
 283
 284         if (!vuser->server_info->ptok) {
 285                 DEBUG(1, ("register_existing_vuid: server_info does not "
 286                         "contain a user_token - cannot continue\n"));
 287                 goto fail;
 288         }
 289
 290         DEBUG(3,("register_existing_vuid: UNIX uid %d is UNIX user %s, "
 291                 "and will be vuid %u\n", (int)vuser->server_info->utok.uid,
 292                  vuser->server_info->unix_name, vuser->vuid));
 293
 294         if (!session_claim(vuser)) {
 295                 DEBUG(1, ("register_existing_vuid: Failed to claim session "
 296                         "for vuid=%d\n",
 297                         vuser->vuid));
 298                 goto fail;
 299         }
 300
 301         /* Register a home dir service for this user if
 302         (a) This is not a guest connection,
 303         (b) we have a home directory defined
 304         (c) there s not an existing static share by that name
 305         If a share exists by this name (autoloaded or not) reuse it . */
 306
 307         vuser->homes_snum = -1;
 308
 309         if (!vuser->server_info->guest) {
 310                 vuser->homes_snum = register_homes_share(
 311                         vuser->server_info->unix_name);
 312         }
 313
 314         if (srv_is_signing_negotiated(smbd_server_conn) &&
 315             !vuser->server_info->guest) {
 316                 /* Try and turn on server signing on the first non-guest
 317                  * sessionsetup. */
 318                 srv_set_signing(smbd_server_conn,
 319                                 vuser->server_info->user_session_key,
 320                                 response_blob);
 321         }
 322
 323         /* fill in the current_user_info struct */
 324         set_current_user_info(
 325                 vuser->server_info->sanitized_username,
 326                 vuser->server_info->unix_name,
 327                 vuser->server_info->info3->base.domain.string);
 328
 329         return vuser->vuid;
 330
 331   fail:
 332
 333         if (vuser) {
 334                 invalidate_vuid(sconn, vuid);
 335         }
 336         return UID_FIELD_INVALID;
 337 }
 338
 339 /****************************************************************************
 340  Add a name to the session users list.
 341 ****************************************************************************/
 342
 343 void add_session_user(struct smbd_server_connection *sconn,
 344                       const char *user)
 345 {
 346         struct passwd *pw;
 347         char *tmp;
 348
 349         pw = Get_Pwnam_alloc(talloc_tos(), user);
 350
 351         if (pw == NULL) {
 352                 return;
 353         }
 354
 355         if (sconn->smb1.sessions.session_userlist == NULL) {
 356                 sconn->smb1.sessions.session_userlist = SMB_STRDUP(pw->pw_name);
 357                 goto done;
 358         }
 359
 360         if (in_list(pw->pw_name,sconn->smb1.sessions.session_userlist,false)) {
 361                 goto done;
 362         }
 363
 364         if (strlen(sconn->smb1.sessions.session_userlist) > 128 * 1024) {
 365                 DEBUG(3,("add_session_user: session userlist already "
 366                          "too large.\n"));
 367                 goto done;
 368         }
 369
 370         if (asprintf(&tmp, "%s %s",
 371                      sconn->smb1.sessions.session_userlist, pw->pw_name) == -1) {
 372                 DEBUG(3, ("asprintf failed\n"));
 373                 goto done;
 374         }
 375
 376         SAFE_FREE(sconn->smb1.sessions.session_userlist);
 377         sconn->smb1.sessions.session_userlist = tmp;
 378  done:
 379         TALLOC_FREE(pw);
 380 }
 381
 382 /****************************************************************************
 383  In security=share mode we need to store the client workgroup, as that's
 384   what Vista uses for the NTLMv2 calculation.
 385 ****************************************************************************/
 386
 387 void add_session_workgroup(struct smbd_server_connection *sconn,
 388                            const char *workgroup)
 389 {
 390         if (sconn->smb1.sessions.session_workgroup) {
 391                 SAFE_FREE(sconn->smb1.sessions.session_workgroup);
 392         }
 393         sconn->smb1.sessions.session_workgroup = smb_xstrdup(workgroup);
 394 }
 395
 396 /****************************************************************************
 397  In security=share mode we need to return the client workgroup, as that's
 398   what Vista uses for the NTLMv2 calculation.
 399 ****************************************************************************/
 400
 401 const char *get_session_workgroup(struct smbd_server_connection *sconn)
 402 {
 403         return sconn->smb1.sessions.session_workgroup;
 404 }
 405
 406 /****************************************************************************
 407  Check if a user is in a netgroup user list. If at first we don't succeed,
 408  try lower case.
 409 ****************************************************************************/
 410
 411 bool user_in_netgroup(const char *user, const char *ngname)
 412 {
 413 #ifdef HAVE_NETGROUP
 414         static char *my_yp_domain = NULL;
 415         fstring lowercase_user;
 416
 417         if (my_yp_domain == NULL) {
 418                 yp_get_default_domain(&my_yp_domain);
 419         }
 420
 421         if (my_yp_domain == NULL) {
 422                 DEBUG(5,("Unable to get default yp domain, "
 423                         "let's try without specifying it\n"));
 424         }
 425
 426         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 427                 user, my_yp_domain?my_yp_domain:"(ANY)", ngname));
 428
 429         if (innetgr(ngname, NULL, user, my_yp_domain)) {
 430                 DEBUG(5,("user_in_netgroup: Found\n"));
 431                 return true;
 432         }
 433
 434         /*
 435          * Ok, innetgr is case sensitive. Try once more with lowercase
 436          * just in case. Attempt to fix #703. JRA.
 437          */
 438         fstrcpy(lowercase_user, user);
 439         strlower_m(lowercase_user);
 440
 441         if (strcmp(user,lowercase_user) == 0) {
 442                 /* user name was already lower case! */
 443                 return false;
 444         }
 445
 446         DEBUG(5,("looking for user %s of domain %s in netgroup %s\n",
 447                 lowercase_user, my_yp_domain?my_yp_domain:"(ANY)", ngname));
 448
 449         if (innetgr(ngname, NULL, lowercase_user, my_yp_domain)) {
 450                 DEBUG(5,("user_in_netgroup: Found\n"));
 451                 return true;
 452         }
 453 #endif /* HAVE_NETGROUP */
 454         return false;
 455 }
 456
 457 /****************************************************************************
 458  Check if a user is in a user list - can check combinations of UNIX
 459  and netgroup lists.
 460 ****************************************************************************/
 461
 462 bool user_in_list(const char *user,const char **list)
 463 {
 464         if (!list || !*list)
 465                 return False;
 466
 467         DEBUG(10,("user_in_list: checking user %s in list\n", user));
 468
 469         while (*list) {
 470
 471                 DEBUG(10,("user_in_list: checking user |%s| against |%s|\n",
 472                           user, *list));
 473
 474                 /*
 475                  * Check raw username.
 476                  */
 477                 if (strequal(user, *list))
 478                         return(True);
 479
 480                 /*
 481                  * Now check to see if any combination
 482                  * of UNIX and netgroups has been specified.
 483                  */
 484
 485                 if(**list == '@') {
 486                         /*
 487                          * Old behaviour. Check netgroup list
 488                          * followed by UNIX list.
 489                          */
 490                         if(user_in_netgroup(user, *list +1))
 491                                 return True;
 492                         if(user_in_group(user, *list +1))
 493                                 return True;
 494                 } else if (**list == '+') {
 495
 496                         if((*(*list +1)) == '&') {
 497                                 /*
 498                                  * Search UNIX list followed by netgroup.
 499                                  */
 500                                 if(user_in_group(user, *list +2))
 501                                         return True;
 502                                 if(user_in_netgroup(user, *list +2))
 503                                         return True;
 504
 505                         } else {
 506
 507                                 /*
 508                                  * Just search UNIX list.
 509                                  */
 510
 511                                 if(user_in_group(user, *list +1))
 512                                         return True;
 513                         }
 514
 515                 } else if (**list == '&') {
 516
 517                         if(*(*list +1) == '+') {
 518                                 /*
 519                                  * Search netgroup list followed by UNIX list.
 520                                  */
 521                                 if(user_in_netgroup(user, *list +2))
 522                                         return True;
 523                                 if(user_in_group(user, *list +2))
 524                                         return True;
 525                         } else {
 526                                 /*
 527                                  * Just search netgroup list.
 528                                  */
 529                                 if(user_in_netgroup(user, *list +1))
 530                                         return True;
 531                         }
 532                 }
 533
 534                 list++;
 535         }
 536         return(False);
 537 }
 538
 539 /****************************************************************************
 540  Check if a username is valid.
 541 ****************************************************************************/
 542
 543 static bool user_ok(struct smbd_server_connection *sconn,
 544                     const char *user, int snum)
 545 {
 546         bool ret;
 547
 548         ret = True;
 549
 550         if (lp_invalid_users(snum)) {
 551                 char **invalid = str_list_copy(talloc_tos(),
 552                         lp_invalid_users(snum));
 553                 if (invalid &&
 554                     str_list_substitute(invalid, "%S", lp_servicename(snum))) {
 555
 556                         /* This is used in sec=share only, so no current user
 557                          * around to pass to str_list_sub_basic() */
 558
 559                         if ( invalid && str_list_sub_basic(invalid, "", "") ) {
 560                                 ret = !user_in_list(user,
 561                                                     (const char **)invalid);
 562                         }
 563                 }
 564                 TALLOC_FREE(invalid);
 565         }
 566
 567         if (ret && lp_valid_users(snum)) {
 568                 char **valid = str_list_copy(talloc_tos(),
 569                         lp_valid_users(snum));
 570                 if ( valid &&
 571                      str_list_substitute(valid, "%S", lp_servicename(snum)) ) {
 572
 573                         /* This is used in sec=share only, so no current user
 574                          * around to pass to str_list_sub_basic() */
 575
 576                         if ( valid && str_list_sub_basic(valid, "", "") ) {
 577                                 ret = user_in_list(user,
 578                                                    (const char **)valid);
 579                         }
 580                 }
 581                 TALLOC_FREE(valid);
 582         }
 583
 584         if (ret && lp_onlyuser(snum)) {
 585                 char **user_list = str_list_make_v3(
 586                         talloc_tos(), lp_username(snum), NULL);
 587                 if (user_list &&
 588                     str_list_substitute(user_list, "%S",
 589                                         lp_servicename(snum))) {
 590                         ret = user_in_list(user,
 591                                            (const char **)user_list);
 592                 }
 593                 TALLOC_FREE(user_list);
 594         }
 595
 596         return(ret);
 597 }
 598
 599 /****************************************************************************
 600  Validate a group username entry. Return the username or NULL.
 601 ****************************************************************************/
 602
 603 static char *validate_group(struct smbd_server_connection *sconn,
 604                             char *group, DATA_BLOB password,int snum)
 605 {
 606 #ifdef HAVE_NETGROUP
 607         {
 608                 char *host, *user, *domain;
 609                 struct auth_context *actx = sconn->smb1.negprot.auth_context;
 610                 bool enc = sconn->smb1.negprot.encrypted_passwords;
 611                 setnetgrent(group);
 612                 while (getnetgrent(&host, &user, &domain)) {
 613                         if (user) {
 614                                 if (user_ok(sconn, user, snum) &&
 615                                     password_ok(actx, enc,
 616                                                 get_session_workgroup(sconn),
 617                                                 user,password)) {
 618                                         endnetgrent();
 619                                         return(user);
 620                                 }
 621                         }
 622                 }
 623                 endnetgrent();
 624         }
 625 #endif
 626
 627 #ifdef HAVE_GETGRENT
 628         {
 629                 struct group *gptr;
 630                 struct auth_context *actx = sconn->smb1.negprot.auth_context;
 631                 bool enc = sconn->smb1.negprot.encrypted_passwords;
 632
 633                 setgrent();
 634                 while ((gptr = (struct group *)getgrent())) {
 635                         if (strequal(gptr->gr_name,group))
 636                                 break;
 637                 }
 638
 639                 /*
 640                  * As user_ok can recurse doing a getgrent(), we must
 641                  * copy the member list onto the heap before
 642                  * use. Bug pointed out by leon@eatworms.swmed.edu.
 643                  */
 644
 645                 if (gptr) {
 646                         char *member_list = NULL;
 647                         size_t list_len = 0;
 648                         char *member;
 649                         int i;
 650
 651                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 652                                 list_len += strlen(gptr->gr_mem[i])+1;
 653                         }
 654                         list_len++;
 655
 656                         member_list = (char *)SMB_MALLOC(list_len);
 657                         if (!member_list) {
 658                                 endgrent();
 659                                 return NULL;
 660                         }
 661
 662                         *member_list = '\0';
 663                         member = member_list;
 664
 665                         for(i = 0; gptr->gr_mem && gptr->gr_mem[i]; i++) {
 666                                 size_t member_len = strlen(gptr->gr_mem[i])+1;
 667
 668                                 DEBUG(10,("validate_group: = gr_mem = "
 669                                           "%s\n", gptr->gr_mem[i]));
 670
 671                                 safe_strcpy(member, gptr->gr_mem[i],
 672                                         list_len - (member-member_list));
 673                                 member += member_len;
 674                         }
 675
 676                         endgrent();
 677
 678                         member = member_list;
 679                         while (*member) {
 680                                 if (user_ok(sconn, member,snum) &&
 681                                     password_ok(actx, enc,
 682                                                 get_session_workgroup(sconn),
 683                                                 member,password)) {
 684                                         char *name = talloc_strdup(talloc_tos(),
 685                                                                 member);
 686                                         SAFE_FREE(member_list);
 687                                         return name;
 688                                 }
 689
 690                                 DEBUG(10,("validate_group = member = %s\n",
 691                                           member));
 692
 693                                 member += strlen(member) + 1;
 694                         }
 695
 696                         SAFE_FREE(member_list);
 697                 } else {
 698                         endgrent();
 699                         return NULL;
 700                 }
 701         }
 702 #endif
 703         return(NULL);
 704 }
 705
 706 /****************************************************************************
 707  Check for authority to login to a service with a given username/password.
 708  Note this is *NOT* used when logging on using sessionsetup_and_X.
 709 ****************************************************************************/
 710
 711 bool authorise_login(struct smbd_server_connection *sconn,
 712                      int snum, fstring user, DATA_BLOB password,
 713                      bool *guest)
 714 {
 715         bool ok = False;
 716         struct auth_context *actx = sconn->smb1.negprot.auth_context;
 717         bool enc = sconn->smb1.negprot.encrypted_passwords;
 718
 719 #ifdef DEBUG_PASSWORD
 720         DEBUG(100,("authorise_login: checking authorisation on "
 721                    "user=%s pass=%s\n", user,password.data));
 722 #endif
 723
 724         *guest = False;
 725
 726         /* there are several possibilities:
 727                 1) login as the given user with given password
 728                 2) login as a previously registered username with the given
 729                    password
 730                 3) login as a session list username with the given password
 731                 4) login as a previously validated user/password pair
 732                 5) login as the "user =" user with given password
 733                 6) login as the "user =" user with no password
 734                    (guest connection)
 735                 7) login as guest user with no password
 736
 737                 if the service is guest_only then steps 1 to 5 are skipped
 738         */
 739
 740         /* now check the list of session users */
 741         if (!ok) {
 742                 char *auser;
 743                 char *user_list = NULL;
 744                 char *saveptr;
 745
 746                 if (sconn->smb1.sessions.session_userlist)
 747                         user_list = SMB_STRDUP(sconn->smb1.sessions.session_userlist);
 748                 else
 749                         user_list = SMB_STRDUP("");
 750
 751                 if (!user_list)
 752                         return(False);
 753
 754                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
 755                      !ok && auser;
 756                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
 757                         fstring user2;
 758                         fstrcpy(user2,auser);
 759                         if (!user_ok(sconn,user2,snum))
 760                                 continue;
 761
 762                         if (password_ok(actx, enc,
 763                                         get_session_workgroup(sconn),
 764                                         user2,password)) {
 765                                 ok = True;
 766                                 fstrcpy(user,user2);
 767                                 DEBUG(3,("authorise_login: ACCEPTED: session "
 768                                          "list username (%s) and given "
 769                                          "password ok\n", user));
 770                         }
 771                 }
 772
 773                 SAFE_FREE(user_list);
 774         }
 775
 776         /* check the user= fields and the given password */
 777         if (!ok && lp_username(snum)) {
 778                 TALLOC_CTX *ctx = talloc_tos();
 779                 char *auser;
 780                 char *user_list = talloc_strdup(ctx, lp_username(snum));
 781                 char *saveptr;
 782
 783                 if (!user_list) {
 784                         goto check_guest;
 785                 }
 786
 787                 user_list = talloc_string_sub(ctx,
 788                                 user_list,
 789                                 "%S",
 790                                 lp_servicename(snum));
 791
 792                 if (!user_list) {
 793                         goto check_guest;
 794                 }
 795
 796                 for (auser = strtok_r(user_list, LIST_SEP, &saveptr);
 797                      auser && !ok;
 798                      auser = strtok_r(NULL, LIST_SEP, &saveptr)) {
 799                         if (*auser == '@') {
 800                                 auser = validate_group(sconn,auser+1,
 801                                                        password,snum);
 802                                 if (auser) {
 803                                         ok = True;
 804                                         fstrcpy(user,auser);
 805                                         DEBUG(3,("authorise_login: ACCEPTED: "
 806                                                  "group username and given "
 807                                                  "password ok (%s)\n", user));
 808                                 }
 809                         } else {
 810                                 fstring user2;
 811                                 fstrcpy(user2,auser);
 812                                 if (user_ok(sconn,user2,snum) &&
 813                                     password_ok(actx, enc,
 814                                                 get_session_workgroup(sconn),
 815                                                 user2,password)) {
 816                                         ok = True;
 817                                         fstrcpy(user,user2);
 818                                         DEBUG(3,("authorise_login: ACCEPTED: "
 819                                                  "user list username and "
 820                                                  "given password ok (%s)\n",
 821                                                  user));
 822                                 }
 823                         }
 824                 }
 825         }
 826
 827   check_guest:
 828
 829         /* check for a normal guest connection */
 830         if (!ok && GUEST_OK(snum)) {
 831                 struct passwd *guest_pw;
 832                 fstring guestname;
 833                 fstrcpy(guestname,lp_guestaccount());
 834                 guest_pw = Get_Pwnam_alloc(talloc_tos(), guestname);
 835                 if (guest_pw != NULL) {
 836                         fstrcpy(user,guestname);
 837                         ok = True;
 838                         DEBUG(3,("authorise_login: ACCEPTED: guest account "
 839                                  "and guest ok (%s)\n", user));
 840                 } else {
 841                         DEBUG(0,("authorise_login: Invalid guest account "
 842                                  "%s??\n",guestname));
 843                 }
 844                 TALLOC_FREE(guest_pw);
 845                 *guest = True;
 846         }
 847
 848         if (ok && !user_ok(sconn, user, snum)) {
 849                 DEBUG(0,("authorise_login: rejected invalid user %s\n",user));
 850                 ok = False;
 851         }
 852
 853         return(ok);
 854 }