source3/auth/token_util.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  Authentication utility functions
   4  *  Copyright (C) Andrew Tridgell 1992-1998
   5  *  Copyright (C) Andrew Bartlett 2001
   6  *  Copyright (C) Jeremy Allison 2000-2001
   7  *  Copyright (C) Rafal Szczesniak 2002
   8  *  Copyright (C) Volker Lendecke 2006
   9  *  Copyright (C) Michael Adam 2007
  10  *
  11  *  This program is free software; you can redistribute it and/or modify
  12  *  it under the terms of the GNU General Public License as published by
  13  *  the Free Software Foundation; either version 3 of the License, or
  14  *  (at your option) any later version.
  15  *
  16  *  This program is distributed in the hope that it will be useful,
  17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  *  GNU General Public License for more details.
  20  *
  21  *  You should have received a copy of the GNU General Public License
  22  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  23  */
  24
  25 /* functions moved from auth/auth_util.c to minimize linker deps */
  26
  27 #include "includes.h"
  28
  29 /****************************************************************************
  30  Check for a SID in an NT_USER_TOKEN
  31 ****************************************************************************/
  32
  33 bool nt_token_check_sid ( const struct dom_sid *sid, const NT_USER_TOKEN *token )
  34 {
  35         int i;
  36
  37         if ( !sid || !token )
  38                 return False;
  39
  40         for ( i=0; i<token->num_sids; i++ ) {
  41                 if ( sid_equal( sid, &token->user_sids[i] ) )
  42                         return True;
  43         }
  44
  45         return False;
  46 }
  47
  48 bool nt_token_check_domain_rid( NT_USER_TOKEN *token, uint32 rid )
  49 {
  50         struct dom_sid domain_sid;
  51
  52         /* if we are a domain member, the get the domain SID, else for
  53            a DC or standalone server, use our own SID */
  54
  55         if ( lp_server_role() == ROLE_DOMAIN_MEMBER ) {
  56                 if ( !secrets_fetch_domain_sid( lp_workgroup(),
  57                                                 &domain_sid ) ) {
  58                         DEBUG(1,("nt_token_check_domain_rid: Cannot lookup "
  59                                  "SID for domain [%s]\n", lp_workgroup()));
  60                         return False;
  61                 }
  62         }
  63         else
  64                 sid_copy( &domain_sid, get_global_sam_sid() );
  65
  66         sid_append_rid( &domain_sid, rid );
  67
  68         return nt_token_check_sid( &domain_sid, token );\
  69 }
  70
  71 /******************************************************************************
  72  Create a token for the root user to be used internally by smbd.
  73  This is similar to running under the context of the LOCAL_SYSTEM account
  74  in Windows.  This is a read-only token.  Do not modify it or free() it.
  75  Create a copy if your need to change it.
  76 ******************************************************************************/
  77
  78 NT_USER_TOKEN *get_root_nt_token( void )
  79 {
  80         struct nt_user_token *token, *for_cache;
  81         struct dom_sid u_sid, g_sid;
  82         struct passwd *pw;
  83         void *cache_data;
  84
  85         cache_data = memcache_lookup_talloc(
  86                 NULL, SINGLETON_CACHE_TALLOC,
  87                 data_blob_string_const_null("root_nt_token"));
  88
  89         if (cache_data != NULL) {
  90                 return talloc_get_type_abort(
  91                         cache_data, struct nt_user_token);
  92         }
  93
  94         if ( !(pw = sys_getpwuid(0)) ) {
  95                 if ( !(pw = sys_getpwnam("root")) ) {
  96                         DEBUG(0,("get_root_nt_token: both sys_getpwuid(0) "
  97                                 "and sys_getpwnam(\"root\") failed!\n"));
  98                         return NULL;
  99                 }
 100         }
 101
 102         /* get the user and primary group SIDs; although the
 103            BUILTIN\Administrators SId is really the one that matters here */
 104
 105         uid_to_sid(&u_sid, pw->pw_uid);
 106         gid_to_sid(&g_sid, pw->pw_gid);
 107
 108         token = create_local_nt_token(talloc_autofree_context(), &u_sid, False,
 109                                       1, &global_sid_Builtin_Administrators);
 110
 111         token->privileges = se_disk_operators;
 112
 113         for_cache = token;
 114
 115         memcache_add_talloc(
 116                 NULL, SINGLETON_CACHE_TALLOC,
 117                 data_blob_string_const_null("root_nt_token"), &for_cache);
 118
 119         return token;
 120 }
 121
 122
 123 /*
 124  * Add alias SIDs from memberships within the partially created token SID list
 125  */
 126
 127 NTSTATUS add_aliases(const struct dom_sid *domain_sid,
 128                      struct nt_user_token *token)
 129 {
 130         uint32 *aliases;
 131         size_t i, num_aliases;
 132         NTSTATUS status;
 133         TALLOC_CTX *tmp_ctx;
 134
 135         if (!(tmp_ctx = talloc_init("add_aliases"))) {
 136                 return NT_STATUS_NO_MEMORY;
 137         }
 138
 139         aliases = NULL;
 140         num_aliases = 0;
 141
 142         status = pdb_enum_alias_memberships(tmp_ctx, domain_sid,
 143                                             token->user_sids,
 144                                             token->num_sids,
 145                                             &aliases, &num_aliases);
 146
 147         if (!NT_STATUS_IS_OK(status)) {
 148                 DEBUG(10, ("pdb_enum_alias_memberships failed: %s\n",
 149                            nt_errstr(status)));
 150                 goto done;
 151         }
 152
 153         for (i=0; i<num_aliases; i++) {
 154                 struct dom_sid alias_sid;
 155                 sid_compose(&alias_sid, domain_sid, aliases[i]);
 156                 status = add_sid_to_array_unique(token, &alias_sid,
 157                                                  &token->user_sids,
 158                                                  &token->num_sids);
 159                 if (!NT_STATUS_IS_OK(status)) {
 160                         DEBUG(0, ("add_sid_to_array failed\n"));
 161                         goto done;
 162                 }
 163         }
 164
 165 done:
 166         TALLOC_FREE(tmp_ctx);
 167         return NT_STATUS_OK;
 168 }
 169
 170 /*******************************************************************
 171 *******************************************************************/
 172
 173 static NTSTATUS add_builtin_administrators(struct nt_user_token *token,
 174                                            const struct dom_sid *dom_sid)
 175 {
 176         struct dom_sid domadm;
 177         NTSTATUS status;
 178
 179         /* nothing to do if we aren't in a domain */
 180
 181         if ( !(IS_DC || lp_server_role()==ROLE_DOMAIN_MEMBER) ) {
 182                 return NT_STATUS_OK;
 183         }
 184
 185         /* Find the Domain Admins SID */
 186
 187         if ( IS_DC ) {
 188                 sid_copy( &domadm, get_global_sam_sid() );
 189         } else {
 190                 sid_copy(&domadm, dom_sid);
 191         }
 192         sid_append_rid( &domadm, DOMAIN_RID_ADMINS );
 193
 194         /* Add Administrators if the user beloongs to Domain Admins */
 195
 196         if ( nt_token_check_sid( &domadm, token ) ) {
 197                 status = add_sid_to_array(token,
 198                                           &global_sid_Builtin_Administrators,
 199                                           &token->user_sids, &token->num_sids);
 200         if (!NT_STATUS_IS_OK(status)) {
 201                         return status;
 202                 }
 203         }
 204
 205         return NT_STATUS_OK;
 206 }
 207
 208 /**
 209  * Create the requested BUILTIN if it doesn't already exist.  This requires
 210  * winbindd to be running.
 211  *
 212  * @param[in] rid BUILTIN rid to create
 213  * @return Normal NTSTATUS return.
 214  */
 215 static NTSTATUS create_builtin(uint32 rid)
 216 {
 217         NTSTATUS status = NT_STATUS_OK;
 218         struct dom_sid sid;
 219         gid_t gid;
 220
 221         if (!sid_compose(&sid, &global_sid_Builtin, rid)) {
 222                 return NT_STATUS_NO_SUCH_ALIAS;
 223         }
 224
 225         if (!sid_to_gid(&sid, &gid)) {
 226                 if (!lp_winbind_nested_groups() || !winbind_ping()) {
 227                         return NT_STATUS_PROTOCOL_UNREACHABLE;
 228                 }
 229                 status = pdb_create_builtin_alias(rid);
 230         }
 231         return status;
 232 }
 233
 234 /**
 235  * Add sid as a member of builtin_sid.
 236  *
 237  * @param[in] builtin_sid       An existing builtin group.
 238  * @param[in] dom_sid           sid to add as a member of builtin_sid.
 239  * @return Normal NTSTATUS return
 240  */
 241 static NTSTATUS add_sid_to_builtin(const struct dom_sid *builtin_sid,
 242                                    const struct dom_sid *dom_sid)
 243 {
 244         NTSTATUS status = NT_STATUS_OK;
 245
 246         if (!dom_sid || !builtin_sid) {
 247                 return NT_STATUS_INVALID_PARAMETER;
 248         }
 249
 250         status = pdb_add_aliasmem(builtin_sid, dom_sid);
 251
 252         if (NT_STATUS_EQUAL(status, NT_STATUS_MEMBER_IN_ALIAS)) {
 253                 DEBUG(5, ("add_sid_to_builtin %s is already a member of %s\n",
 254                           sid_string_dbg(dom_sid),
 255                           sid_string_dbg(builtin_sid)));
 256                 return NT_STATUS_OK;
 257         }
 258
 259         if (!NT_STATUS_IS_OK(status)) {
 260                 DEBUG(4, ("add_sid_to_builtin %s could not be added to %s: "
 261                           "%s\n", sid_string_dbg(dom_sid),
 262                           sid_string_dbg(builtin_sid), nt_errstr(status)));
 263         }
 264         return status;
 265 }
 266
 267 /*******************************************************************
 268 *******************************************************************/
 269
 270 NTSTATUS create_builtin_users(const struct dom_sid *dom_sid)
 271 {
 272         NTSTATUS status;
 273         struct dom_sid dom_users;
 274
 275         status = create_builtin(BUILTIN_RID_USERS);
 276         if ( !NT_STATUS_IS_OK(status) ) {
 277                 DEBUG(5,("create_builtin_users: Failed to create Users\n"));
 278                 return status;
 279         }
 280
 281         /* add domain users */
 282         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 283                 && sid_compose(&dom_users, dom_sid, DOMAIN_RID_USERS))
 284         {
 285                 status = add_sid_to_builtin(&global_sid_Builtin_Users,
 286                                             &dom_users);
 287         }
 288
 289         return status;
 290 }
 291
 292 /*******************************************************************
 293 *******************************************************************/
 294
 295 NTSTATUS create_builtin_administrators(const struct dom_sid *dom_sid)
 296 {
 297         NTSTATUS status;
 298         struct dom_sid dom_admins, root_sid;
 299         fstring root_name;
 300         enum lsa_SidType type;
 301         TALLOC_CTX *ctx;
 302         bool ret;
 303
 304         status = create_builtin(BUILTIN_RID_ADMINISTRATORS);
 305         if ( !NT_STATUS_IS_OK(status) ) {
 306                 DEBUG(5,("create_builtin_administrators: Failed to create Administrators\n"));
 307                 return status;
 308         }
 309
 310         /* add domain admins */
 311         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 312                 && sid_compose(&dom_admins, dom_sid, DOMAIN_RID_ADMINS))
 313         {
 314                 status = add_sid_to_builtin(&global_sid_Builtin_Administrators,
 315                                             &dom_admins);
 316                 if (!NT_STATUS_IS_OK(status)) {
 317                         return status;
 318                 }
 319         }
 320
 321         /* add root */
 322         if ( (ctx = talloc_init("create_builtin_administrators")) == NULL ) {
 323                 return NT_STATUS_NO_MEMORY;
 324         }
 325         fstr_sprintf( root_name, "%s\\root", get_global_sam_name() );
 326         ret = lookup_name(ctx, root_name, LOOKUP_NAME_DOMAIN, NULL, NULL,
 327                           &root_sid, &type);
 328         TALLOC_FREE( ctx );
 329
 330         if ( ret ) {
 331                 status = add_sid_to_builtin(&global_sid_Builtin_Administrators,
 332                                             &root_sid);
 333         }
 334
 335         return status;
 336 }
 337
 338
 339 /*******************************************************************
 340  Create a NT token for the user, expanding local aliases
 341 *******************************************************************/
 342
 343 struct nt_user_token *create_local_nt_token(TALLOC_CTX *mem_ctx,
 344                                             const struct dom_sid *user_sid,
 345                                             bool is_guest,
 346                                             int num_groupsids,
 347                                             const struct dom_sid *groupsids)
 348 {
 349         struct nt_user_token *result = NULL;
 350         int i;
 351         NTSTATUS status;
 352         gid_t gid;
 353         struct dom_sid dom_sid;
 354
 355         DEBUG(10, ("Create local NT token for %s\n",
 356                    sid_string_dbg(user_sid)));
 357
 358         if (!(result = TALLOC_ZERO_P(mem_ctx, struct nt_user_token))) {
 359                 DEBUG(0, ("talloc failed\n"));
 360                 return NULL;
 361         }
 362
 363         /* Add the user and primary group sid */
 364
 365         status = add_sid_to_array(result, user_sid,
 366                                   &result->user_sids, &result->num_sids);
 367         if (!NT_STATUS_IS_OK(status)) {
 368                 return NULL;
 369         }
 370
 371         /* For guest, num_groupsids may be zero. */
 372         if (num_groupsids) {
 373                 status = add_sid_to_array(result, &groupsids[0],
 374                                           &result->user_sids,
 375                                           &result->num_sids);
 376                 if (!NT_STATUS_IS_OK(status)) {
 377                         return NULL;
 378                 }
 379         }
 380
 381         /* Add in BUILTIN sids */
 382
 383         status = add_sid_to_array(result, &global_sid_World,
 384                                   &result->user_sids, &result->num_sids);
 385         if (!NT_STATUS_IS_OK(status)) {
 386                 return NULL;
 387         }
 388         status = add_sid_to_array(result, &global_sid_Network,
 389                                   &result->user_sids, &result->num_sids);
 390         if (!NT_STATUS_IS_OK(status)) {
 391                 return NULL;
 392         }
 393
 394         if (is_guest) {
 395                 status = add_sid_to_array(result, &global_sid_Builtin_Guests,
 396                                           &result->user_sids,
 397                                           &result->num_sids);
 398                 if (!NT_STATUS_IS_OK(status)) {
 399                         return NULL;
 400                 }
 401         } else {
 402                 status = add_sid_to_array(result,
 403                                           &global_sid_Authenticated_Users,
 404                                           &result->user_sids,
 405                                           &result->num_sids);
 406                 if (!NT_STATUS_IS_OK(status)) {
 407                         return NULL;
 408                 }
 409         }
 410
 411         /* Now the SIDs we got from authentication. These are the ones from
 412          * the info3 struct or from the pdb_enum_group_memberships, depending
 413          * on who authenticated the user.
 414          * Note that we start the for loop at "1" here, we already added the
 415          * first group sid as primary above. */
 416
 417         for (i=1; i<num_groupsids; i++) {
 418                 status = add_sid_to_array_unique(result, &groupsids[i],
 419                                                  &result->user_sids,
 420                                                  &result->num_sids);
 421                 if (!NT_STATUS_IS_OK(status)) {
 422                         return NULL;
 423                 }
 424         }
 425
 426         /* Deal with the BUILTIN\Administrators group.  If the SID can
 427            be resolved then assume that the add_aliasmem( S-1-5-32 )
 428            handled it. */
 429
 430         if (!sid_to_gid(&global_sid_Builtin_Administrators, &gid)) {
 431
 432                 become_root();
 433                 if (!secrets_fetch_domain_sid(lp_workgroup(), &dom_sid)) {
 434                         status = NT_STATUS_OK;
 435                         DEBUG(3, ("Failed to fetch domain sid for %s\n",
 436                                   lp_workgroup()));
 437                 } else {
 438                         status = create_builtin_administrators(&dom_sid);
 439                 }
 440                 unbecome_root();
 441
 442                 if (NT_STATUS_EQUAL(status, NT_STATUS_PROTOCOL_UNREACHABLE)) {
 443                         /* Add BUILTIN\Administrators directly to token. */
 444                         status = add_builtin_administrators(result, &dom_sid);
 445                         if ( !NT_STATUS_IS_OK(status) ) {
 446                                 DEBUG(3, ("Failed to check for local "
 447                                           "Administrators membership (%s)\n",
 448                                           nt_errstr(status)));
 449                         }
 450                 } else if (!NT_STATUS_IS_OK(status)) {
 451                         DEBUG(2, ("WARNING: Failed to create "
 452                                   "BUILTIN\\Administrators group!  Can "
 453                                   "Winbind allocate gids?\n"));
 454                 }
 455         }
 456
 457         /* Deal with the BUILTIN\Users group.  If the SID can
 458            be resolved then assume that the add_aliasmem( S-1-5-32 )
 459            handled it. */
 460
 461         if (!sid_to_gid(&global_sid_Builtin_Users, &gid)) {
 462
 463                 become_root();
 464                 if (!secrets_fetch_domain_sid(lp_workgroup(), &dom_sid)) {
 465                         status = NT_STATUS_OK;
 466                         DEBUG(3, ("Failed to fetch domain sid for %s\n",
 467                                   lp_workgroup()));
 468                 } else {
 469                         status = create_builtin_users(&dom_sid);
 470                 }
 471                 unbecome_root();
 472
 473                 if (!NT_STATUS_EQUAL(status, NT_STATUS_PROTOCOL_UNREACHABLE) &&
 474                     !NT_STATUS_IS_OK(status))
 475                 {
 476                         DEBUG(2, ("WARNING: Failed to create BUILTIN\\Users group! "
 477                                   "Can Winbind allocate gids?\n"));
 478                 }
 479         }
 480
 481         /* Deal with local groups */
 482
 483         if (lp_winbind_nested_groups()) {
 484
 485                 become_root();
 486
 487                 /* Now add the aliases. First the one from our local SAM */
 488
 489                 status = add_aliases(get_global_sam_sid(), result);
 490
 491                 if (!NT_STATUS_IS_OK(status)) {
 492                         unbecome_root();
 493                         TALLOC_FREE(result);
 494                         return NULL;
 495                 }
 496
 497                 /* Finally the builtin ones */
 498
 499                 status = add_aliases(&global_sid_Builtin, result);
 500
 501                 if (!NT_STATUS_IS_OK(status)) {
 502                         unbecome_root();
 503                         TALLOC_FREE(result);
 504                         return NULL;
 505                 }
 506
 507                 unbecome_root();
 508         }
 509
 510
 511         get_privileges_for_sids(&result->privileges, result->user_sids,
 512                                 result->num_sids);
 513         return result;
 514 }
 515
 516 /****************************************************************************
 517  prints a NT_USER_TOKEN to debug output.
 518 ****************************************************************************/
 519
 520 void debug_nt_user_token(int dbg_class, int dbg_lev, NT_USER_TOKEN *token)
 521 {
 522         size_t     i;
 523
 524         if (!token) {
 525                 DEBUGC(dbg_class, dbg_lev, ("NT user token: (NULL)\n"));
 526                 return;
 527         }
 528
 529         DEBUGC(dbg_class, dbg_lev,
 530                ("NT user token of user %s\n",
 531                 sid_string_dbg(&token->user_sids[0]) ));
 532         DEBUGADDC(dbg_class, dbg_lev,
 533                   ("contains %lu SIDs\n", (unsigned long)token->num_sids));
 534         for (i = 0; i < token->num_sids; i++)
 535                 DEBUGADDC(dbg_class, dbg_lev,
 536                           ("SID[%3lu]: %s\n", (unsigned long)i,
 537                            sid_string_dbg(&token->user_sids[i])));
 538
 539         dump_se_priv( dbg_class, dbg_lev, &token->privileges );
 540 }
 541
 542 /****************************************************************************
 543  prints a UNIX 'token' to debug output.
 544 ****************************************************************************/
 545
 546 void debug_unix_user_token(int dbg_class, int dbg_lev, uid_t uid, gid_t gid,
 547                            int n_groups, gid_t *groups)
 548 {
 549         int     i;
 550         DEBUGC(dbg_class, dbg_lev,
 551                ("UNIX token of user %ld\n", (long int)uid));
 552
 553         DEBUGADDC(dbg_class, dbg_lev,
 554                   ("Primary group is %ld and contains %i supplementary "
 555                    "groups\n", (long int)gid, n_groups));
 556         for (i = 0; i < n_groups; i++)
 557                 DEBUGADDC(dbg_class, dbg_lev, ("Group[%3i]: %ld\n", i,
 558                         (long int)groups[i]));
 559 }
 560
 561 /*
 562  * Create an artificial NT token given just a username. (Initially intended
 563  * for force user)
 564  *
 565  * We go through lookup_name() to avoid problems we had with 'winbind use
 566  * default domain'.
 567  *
 568  * We have 3 cases:
 569  *
 570  * unmapped unix users: Go directly to nss to find the user's group.
 571  *
 572  * A passdb user: The list of groups is provided by pdb_enum_group_memberships.
 573  *
 574  * If the user is provided by winbind, the primary gid is set to "domain
 575  * users" of the user's domain. For an explanation why this is necessary, see
 576  * the thread starting at
 577  * http://lists.samba.org/archive/samba-technical/2006-January/044803.html.
 578  */
 579
 580 NTSTATUS create_token_from_username(TALLOC_CTX *mem_ctx, const char *username,
 581                                     bool is_guest,
 582                                     uid_t *uid, gid_t *gid,
 583                                     char **found_username,
 584                                     struct nt_user_token **token)
 585 {
 586         NTSTATUS result = NT_STATUS_NO_SUCH_USER;
 587         TALLOC_CTX *tmp_ctx = talloc_stackframe();
 588         struct dom_sid user_sid;
 589         enum lsa_SidType type;
 590         gid_t *gids;
 591         struct dom_sid *group_sids;
 592         struct dom_sid unix_group_sid;
 593         size_t num_group_sids;
 594         size_t num_gids;
 595         size_t i;
 596
 597         if (!lookup_name_smbconf(tmp_ctx, username, LOOKUP_NAME_ALL,
 598                          NULL, NULL, &user_sid, &type)) {
 599                 DEBUG(1, ("lookup_name_smbconf for %s failed\n", username));
 600                 goto done;
 601         }
 602
 603         if (type != SID_NAME_USER) {
 604                 DEBUG(1, ("%s is a %s, not a user\n", username,
 605                           sid_type_lookup(type)));
 606                 goto done;
 607         }
 608
 609         if (sid_check_is_in_our_domain(&user_sid)) {
 610                 bool ret;
 611
 612                 /* This is a passdb user, so ask passdb */
 613
 614                 struct samu *sam_acct = NULL;
 615
 616                 if ( !(sam_acct = samu_new( tmp_ctx )) ) {
 617                         result = NT_STATUS_NO_MEMORY;
 618                         goto done;
 619                 }
 620
 621                 become_root();
 622                 ret = pdb_getsampwsid(sam_acct, &user_sid);
 623                 unbecome_root();
 624
 625                 if (!ret) {
 626                         DEBUG(1, ("pdb_getsampwsid(%s) for user %s failed\n",
 627                                   sid_string_dbg(&user_sid), username));
 628                         DEBUGADD(1, ("Fall back to unix user %s\n", username));
 629                         goto unix_user;
 630                 }
 631
 632                 result = pdb_enum_group_memberships(tmp_ctx, sam_acct,
 633                                                     &group_sids, &gids,
 634                                                     &num_group_sids);
 635                 if (!NT_STATUS_IS_OK(result)) {
 636                         DEBUG(1, ("enum_group_memberships failed for %s (%s): "
 637                                   "%s\n", username, sid_string_dbg(&user_sid),
 638                                   nt_errstr(result)));
 639                         DEBUGADD(1, ("Fall back to unix user %s\n", username));
 640                         goto unix_user;
 641                 }
 642
 643                 /* see the smb_panic() in pdb_default_enum_group_memberships */
 644                 SMB_ASSERT(num_group_sids > 0);
 645
 646                 *gid = gids[0];
 647
 648                 /* Ensure we're returning the found_username on the right context. */
 649                 *found_username = talloc_strdup(mem_ctx,
 650                                                 pdb_get_username(sam_acct));
 651
 652                 /*
 653                  * If the SID from lookup_name() was the guest sid, passdb knows
 654                  * about the mapping of guest sid to lp_guestaccount()
 655                  * username and will return the unix_pw info for a guest
 656                  * user. Use it if it's there, else lookup the *uid details
 657                  * using getpwnam_alloc(). See bug #6291 for details. JRA.
 658                  */
 659
 660                 /* We must always assign the *uid. */
 661                 if (sam_acct->unix_pw == NULL) {
 662                         struct passwd *pwd = getpwnam_alloc(sam_acct, *found_username );
 663                         if (!pwd) {
 664                                 DEBUG(10, ("getpwnam_alloc failed for %s\n",
 665                                         *found_username));
 666                                 result = NT_STATUS_NO_SUCH_USER;
 667                                 goto done;
 668                         }
 669                         result = samu_set_unix(sam_acct, pwd );
 670                         if (!NT_STATUS_IS_OK(result)) {
 671                                 DEBUG(10, ("samu_set_unix failed for %s\n",
 672                                         *found_username));
 673                                 result = NT_STATUS_NO_SUCH_USER;
 674                                 goto done;
 675                         }
 676                 }
 677                 *uid = sam_acct->unix_pw->pw_uid;
 678
 679         } else  if (sid_check_is_in_unix_users(&user_sid)) {
 680
 681                 /* This is a unix user not in passdb. We need to ask nss
 682                  * directly, without consulting passdb */
 683
 684                 struct passwd *pass;
 685
 686                 /*
 687                  * This goto target is used as a fallback for the passdb
 688                  * case. The concrete bug report is when passdb gave us an
 689                  * unmapped gid.
 690                  */
 691
 692         unix_user:
 693
 694                 if (!sid_to_uid(&user_sid, uid)) {
 695                         DEBUG(1, ("unix_user case, sid_to_uid for %s (%s) failed\n",
 696                                   username, sid_string_dbg(&user_sid)));
 697                         result = NT_STATUS_NO_SUCH_USER;
 698                         goto done;
 699                 }
 700
 701                 uid_to_unix_users_sid(*uid, &user_sid);
 702
 703                 pass = getpwuid_alloc(tmp_ctx, *uid);
 704                 if (pass == NULL) {
 705                         DEBUG(1, ("getpwuid(%u) for user %s failed\n",
 706                                   (unsigned int)*uid, username));
 707                         goto done;
 708                 }
 709
 710                 if (!getgroups_unix_user(tmp_ctx, username, pass->pw_gid,
 711                                          &gids, &num_group_sids)) {
 712                         DEBUG(1, ("getgroups_unix_user for user %s failed\n",
 713                                   username));
 714                         goto done;
 715                 }
 716
 717                 if (num_group_sids) {
 718                         group_sids = TALLOC_ARRAY(tmp_ctx, struct dom_sid, num_group_sids);
 719                         if (group_sids == NULL) {
 720                                 DEBUG(1, ("TALLOC_ARRAY failed\n"));
 721                                 result = NT_STATUS_NO_MEMORY;
 722                                 goto done;
 723                         }
 724                 } else {
 725                         group_sids = NULL;
 726                 }
 727
 728                 for (i=0; i<num_group_sids; i++) {
 729                         gid_to_sid(&group_sids[i], gids[i]);
 730                 }
 731
 732                 /* In getgroups_unix_user we always set the primary gid */
 733                 SMB_ASSERT(num_group_sids > 0);
 734
 735                 *gid = gids[0];
 736
 737                 /* Ensure we're returning the found_username on the right context. */
 738                 *found_username = talloc_strdup(mem_ctx, pass->pw_name);
 739         } else {
 740
 741                 /* This user is from winbind, force the primary gid to the
 742                  * user's "domain users" group. Under certain circumstances
 743                  * (user comes from NT4), this might be a loss of
 744                  * information. But we can not rely on winbind getting the
 745                  * correct info. AD might prohibit winbind looking up that
 746                  * information. */
 747
 748                 uint32 dummy;
 749
 750                 /* We must always assign the *uid. */
 751                 if (!sid_to_uid(&user_sid, uid)) {
 752                         DEBUG(1, ("winbindd case, sid_to_uid for %s (%s) failed\n",
 753                                   username, sid_string_dbg(&user_sid)));
 754                         result = NT_STATUS_NO_SUCH_USER;
 755                         goto done;
 756                 }
 757
 758                 num_group_sids = 1;
 759                 group_sids = TALLOC_ARRAY(tmp_ctx, struct dom_sid, num_group_sids);
 760                 if (group_sids == NULL) {
 761                         DEBUG(1, ("TALLOC_ARRAY failed\n"));
 762                         result = NT_STATUS_NO_MEMORY;
 763                         goto done;
 764                 }
 765
 766                 sid_copy(&group_sids[0], &user_sid);
 767                 sid_split_rid(&group_sids[0], &dummy);
 768                 sid_append_rid(&group_sids[0], DOMAIN_RID_USERS);
 769
 770                 if (!sid_to_gid(&group_sids[0], gid)) {
 771                         DEBUG(1, ("sid_to_gid(%s) failed\n",
 772                                   sid_string_dbg(&group_sids[0])));
 773                         goto done;
 774                 }
 775
 776                 gids = gid;
 777
 778                 /* Ensure we're returning the found_username on the right context. */
 779                 *found_username = talloc_strdup(mem_ctx, username);
 780         }
 781
 782         /* Add the "Unix Group" SID for each gid to catch mapped groups
 783            and their Unix equivalent.  This is to solve the backwards
 784            compatibility problem of 'valid users = +ntadmin' where
 785            ntadmin has been paired with "Domain Admins" in the group
 786            mapping table.  Otherwise smb.conf would need to be changed
 787            to 'valid user = "Domain Admins"'.  --jerry */
 788
 789         num_gids = num_group_sids;
 790         for ( i=0; i<num_gids; i++ ) {
 791                 gid_t high, low;
 792
 793                 /* don't pickup anything managed by Winbind */
 794
 795                 if ( lp_idmap_gid(&low, &high) && (gids[i] >= low) && (gids[i] <= high) )
 796                         continue;
 797
 798                 if ( !gid_to_unix_groups_sid( gids[i], &unix_group_sid ) ) {
 799                         DEBUG(1,("create_token_from_username: Failed to create SID "
 800                                 "for gid %u!\n", (unsigned int)gids[i]));
 801                         continue;
 802                 }
 803                 result = add_sid_to_array_unique(tmp_ctx, &unix_group_sid,
 804                                                  &group_sids, &num_group_sids);
 805                 if (!NT_STATUS_IS_OK(result)) {
 806                         goto done;
 807                 }
 808         }
 809
 810         /* Ensure we're creating the nt_token on the right context. */
 811         *token = create_local_nt_token(mem_ctx, &user_sid,
 812                                        is_guest, num_group_sids, group_sids);
 813
 814         if ((*token == NULL) || (*found_username == NULL)) {
 815                 result = NT_STATUS_NO_MEMORY;
 816                 goto done;
 817         }
 818
 819         result = NT_STATUS_OK;
 820  done:
 821         TALLOC_FREE(tmp_ctx);
 822         return result;
 823 }
 824
 825 /***************************************************************************
 826  Build upon create_token_from_username:
 827
 828  Expensive helper function to figure out whether a user given its name is
 829  member of a particular group.
 830 ***************************************************************************/
 831
 832 bool user_in_group_sid(const char *username, const struct dom_sid *group_sid)
 833 {
 834         NTSTATUS status;
 835         uid_t uid;
 836         gid_t gid;
 837         char *found_username;
 838         struct nt_user_token *token;
 839         bool result;
 840         TALLOC_CTX *mem_ctx = talloc_stackframe();
 841
 842         status = create_token_from_username(mem_ctx, username, False,
 843                                             &uid, &gid, &found_username,
 844                                             &token);
 845
 846         if (!NT_STATUS_IS_OK(status)) {
 847                 DEBUG(10, ("could not create token for %s\n", username));
 848                 TALLOC_FREE(mem_ctx);
 849                 return False;
 850         }
 851
 852         result = nt_token_check_sid(group_sid, token);
 853
 854         TALLOC_FREE(mem_ctx);
 855         return result;
 856 }
 857
 858 bool user_in_group(const char *username, const char *groupname)
 859 {
 860         TALLOC_CTX *mem_ctx = talloc_stackframe();
 861         struct dom_sid group_sid;
 862         bool ret;
 863
 864         ret = lookup_name(mem_ctx, groupname, LOOKUP_NAME_ALL,
 865                           NULL, NULL, &group_sid, NULL);
 866         TALLOC_FREE(mem_ctx);
 867
 868         if (!ret) {
 869                 DEBUG(10, ("lookup_name for (%s) failed.\n", groupname));
 870                 return False;
 871         }
 872
 873         return user_in_group_sid(username, &group_sid);
 874 }
 875
 876 /* END */