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 #include "system/passwd.h"
  29 #include "auth.h"
  30 #include "secrets.h"
  31 #include "memcache.h"
  32 #include "../librpc/gen_ndr/netlogon.h"
  33 #include "../libcli/security/security.h"
  34 #include "../lib/util/util_pw.h"
  35 #include "passdb.h"
  36 #include "lib/privileges.h"
  37
  38 /****************************************************************************
  39  Check for a SID in an struct security_token
  40 ****************************************************************************/
  41
  42 bool nt_token_check_sid ( const struct dom_sid *sid, const struct security_token *token )
  43 {
  44         if ( !sid || !token )
  45                 return False;
  46
  47         return security_token_has_sid(token, sid);
  48 }
  49
  50 bool nt_token_check_domain_rid( struct security_token *token, uint32 rid )
  51 {
  52         struct dom_sid domain_sid;
  53
  54         /* if we are a domain member, the get the domain SID, else for
  55            a DC or standalone server, use our own SID */
  56
  57         if ( lp_server_role() == ROLE_DOMAIN_MEMBER ) {
  58                 if ( !secrets_fetch_domain_sid( lp_workgroup(),
  59                                                 &domain_sid ) ) {
  60                         DEBUG(1,("nt_token_check_domain_rid: Cannot lookup "
  61                                  "SID for domain [%s]\n", lp_workgroup()));
  62                         return False;
  63                 }
  64         }
  65         else
  66                 sid_copy( &domain_sid, get_global_sam_sid() );
  67
  68         sid_append_rid( &domain_sid, rid );
  69
  70         return nt_token_check_sid( &domain_sid, token );\
  71 }
  72
  73 /******************************************************************************
  74  Create a token for the root user to be used internally by smbd.
  75  This is similar to running under the context of the LOCAL_SYSTEM account
  76  in Windows.  This is a read-only token.  Do not modify it or free() it.
  77  Create a copy if you need to change it.
  78 ******************************************************************************/
  79
  80 struct security_token *get_root_nt_token( void )
  81 {
  82         struct security_token *token, *for_cache;
  83         struct dom_sid u_sid, g_sid;
  84         struct passwd *pw;
  85         void *cache_data;
  86
  87         cache_data = memcache_lookup_talloc(
  88                 NULL, SINGLETON_CACHE_TALLOC,
  89                 data_blob_string_const_null("root_nt_token"));
  90
  91         if (cache_data != NULL) {
  92                 return talloc_get_type_abort(
  93                         cache_data, struct security_token);
  94         }
  95
  96         if ( !(pw = getpwuid(0)) ) {
  97                 if ( !(pw = getpwnam("root")) ) {
  98                         DEBUG(0,("get_root_nt_token: both getpwuid(0) "
  99                                 "and getpwnam(\"root\") failed!\n"));
 100                         return NULL;
 101                 }
 102         }
 103
 104         /* get the user and primary group SIDs; although the
 105            BUILTIN\Administrators SId is really the one that matters here */
 106
 107         uid_to_sid(&u_sid, pw->pw_uid);
 108         gid_to_sid(&g_sid, pw->pw_gid);
 109
 110         token = create_local_nt_token(talloc_tos(), &u_sid, False,
 111                                       1, &global_sid_Builtin_Administrators);
 112
 113         security_token_set_privilege(token, SEC_PRIV_DISK_OPERATOR);
 114
 115         for_cache = token;
 116
 117         memcache_add_talloc(
 118                 NULL, SINGLETON_CACHE_TALLOC,
 119                 data_blob_string_const_null("root_nt_token"), &for_cache);
 120
 121         return token;
 122 }
 123
 124
 125 /*
 126  * Add alias SIDs from memberships within the partially created token SID list
 127  */
 128
 129 NTSTATUS add_aliases(const struct dom_sid *domain_sid,
 130                      struct security_token *token)
 131 {
 132         uint32 *aliases;
 133         size_t i, num_aliases;
 134         NTSTATUS status;
 135         TALLOC_CTX *tmp_ctx;
 136
 137         if (!(tmp_ctx = talloc_init("add_aliases"))) {
 138                 return NT_STATUS_NO_MEMORY;
 139         }
 140
 141         aliases = NULL;
 142         num_aliases = 0;
 143
 144         status = pdb_enum_alias_memberships(tmp_ctx, domain_sid,
 145                                             token->sids,
 146                                             token->num_sids,
 147                                             &aliases, &num_aliases);
 148
 149         if (!NT_STATUS_IS_OK(status)) {
 150                 DEBUG(10, ("pdb_enum_alias_memberships failed: %s\n",
 151                            nt_errstr(status)));
 152                 goto done;
 153         }
 154
 155         for (i=0; i<num_aliases; i++) {
 156                 struct dom_sid alias_sid;
 157                 sid_compose(&alias_sid, domain_sid, aliases[i]);
 158                 status = add_sid_to_array_unique(token, &alias_sid,
 159                                                  &token->sids,
 160                                                  &token->num_sids);
 161                 if (!NT_STATUS_IS_OK(status)) {
 162                         DEBUG(0, ("add_sid_to_array failed\n"));
 163                         goto done;
 164                 }
 165         }
 166
 167 done:
 168         TALLOC_FREE(tmp_ctx);
 169         return NT_STATUS_OK;
 170 }
 171
 172 /*******************************************************************
 173 *******************************************************************/
 174
 175 static NTSTATUS add_builtin_administrators(struct security_token *token,
 176                                            const struct dom_sid *dom_sid)
 177 {
 178         struct dom_sid domadm;
 179         NTSTATUS status;
 180
 181         /* nothing to do if we aren't in a domain */
 182
 183         if ( !(IS_DC || lp_server_role()==ROLE_DOMAIN_MEMBER) ) {
 184                 return NT_STATUS_OK;
 185         }
 186
 187         /* Find the Domain Admins SID */
 188
 189         if ( IS_DC ) {
 190                 sid_copy( &domadm, get_global_sam_sid() );
 191         } else {
 192                 sid_copy(&domadm, dom_sid);
 193         }
 194         sid_append_rid( &domadm, DOMAIN_RID_ADMINS );
 195
 196         /* Add Administrators if the user beloongs to Domain Admins */
 197
 198         if ( nt_token_check_sid( &domadm, token ) ) {
 199                 status = add_sid_to_array(token,
 200                                           &global_sid_Builtin_Administrators,
 201                                           &token->sids, &token->num_sids);
 202         if (!NT_STATUS_IS_OK(status)) {
 203                         return status;
 204                 }
 205         }
 206
 207         return NT_STATUS_OK;
 208 }
 209
 210 static NTSTATUS finalize_local_nt_token(struct security_token *result,
 211                                         bool is_guest);
 212
 213 NTSTATUS create_local_nt_token_from_info3(TALLOC_CTX *mem_ctx,
 214                                           bool is_guest,
 215                                           const struct netr_SamInfo3 *info3,
 216                                           const struct extra_auth_info *extra,
 217                                           struct security_token **ntok)
 218 {
 219         struct security_token *usrtok = NULL;
 220         NTSTATUS status;
 221         int i;
 222
 223         DEBUG(10, ("Create local NT token for %s\n",
 224                    info3->base.account_name.string));
 225
 226         usrtok = talloc_zero(mem_ctx, struct security_token);
 227         if (!usrtok) {
 228                 DEBUG(0, ("talloc failed\n"));
 229                 return NT_STATUS_NO_MEMORY;
 230         }
 231
 232         /* Add the user and primary group sid FIRST */
 233         /* check if the user rid is the special "Domain Guests" rid.
 234          * If so pick the first sid for the extra sids instead as it
 235          * is a local fake account */
 236         usrtok->sids = talloc_array(usrtok, struct dom_sid, 2);
 237         if (!usrtok->sids) {
 238                 TALLOC_FREE(usrtok);
 239                 return NT_STATUS_NO_MEMORY;
 240         }
 241         usrtok->num_sids = 2;
 242
 243         /* USER SID */
 244         if (info3->base.rid == (uint32_t)(-1)) {
 245                 /* this is a signal the user was fake and generated,
 246                  * the actual SID we want to use is stored in the extra
 247                  * sids */
 248                 if (is_null_sid(&extra->user_sid)) {
 249                         /* we couldn't find the user sid, bail out */
 250                         DEBUG(3, ("Invalid user SID\n"));
 251                         TALLOC_FREE(usrtok);
 252                         return NT_STATUS_UNSUCCESSFUL;
 253                 }
 254                 sid_copy(&usrtok->sids[0], &extra->user_sid);
 255         } else {
 256                 sid_copy(&usrtok->sids[0], info3->base.domain_sid);
 257                 sid_append_rid(&usrtok->sids[0], info3->base.rid);
 258         }
 259
 260         /* GROUP SID */
 261         if (info3->base.primary_gid == (uint32_t)(-1)) {
 262                 /* this is a signal the user was fake and generated,
 263                  * the actual SID we want to use is stored in the extra
 264                  * sids */
 265                 if (is_null_sid(&extra->pgid_sid)) {
 266                         /* we couldn't find the user sid, bail out */
 267                         DEBUG(3, ("Invalid group SID\n"));
 268                         TALLOC_FREE(usrtok);
 269                         return NT_STATUS_UNSUCCESSFUL;
 270                 }
 271                 sid_copy(&usrtok->sids[1], &extra->pgid_sid);
 272         } else {
 273                 sid_copy(&usrtok->sids[1], info3->base.domain_sid);
 274                 sid_append_rid(&usrtok->sids[1],
 275                                 info3->base.primary_gid);
 276         }
 277
 278         /* Now the SIDs we got from authentication. These are the ones from
 279          * the info3 struct or from the pdb_enum_group_memberships, depending
 280          * on who authenticated the user.
 281          * Note that we start the for loop at "1" here, we already added the
 282          * first group sid as primary above. */
 283
 284         for (i = 0; i < info3->base.groups.count; i++) {
 285                 struct dom_sid tmp_sid;
 286
 287                 sid_copy(&tmp_sid, info3->base.domain_sid);
 288                 sid_append_rid(&tmp_sid, info3->base.groups.rids[i].rid);
 289
 290                 status = add_sid_to_array_unique(usrtok, &tmp_sid,
 291                                                  &usrtok->sids,
 292                                                  &usrtok->num_sids);
 293                 if (!NT_STATUS_IS_OK(status)) {
 294                         DEBUG(3, ("Failed to add SID to nt token\n"));
 295                         TALLOC_FREE(usrtok);
 296                         return status;
 297                 }
 298         }
 299
 300         /* now also add extra sids if they are not the special user/group
 301          * sids */
 302         for (i = 0; i < info3->sidcount; i++) {
 303                 status = add_sid_to_array_unique(usrtok,
 304                                                  info3->sids[i].sid,
 305                                                  &usrtok->sids,
 306                                                  &usrtok->num_sids);
 307                 if (!NT_STATUS_IS_OK(status)) {
 308                         DEBUG(3, ("Failed to add SID to nt token\n"));
 309                         TALLOC_FREE(usrtok);
 310                         return status;
 311                 }
 312         }
 313
 314         status = finalize_local_nt_token(usrtok, is_guest);
 315         if (!NT_STATUS_IS_OK(status)) {
 316                 DEBUG(3, ("Failed to finalize nt token\n"));
 317                 TALLOC_FREE(usrtok);
 318                 return status;
 319         }
 320
 321         *ntok = usrtok;
 322         return NT_STATUS_OK;
 323 }
 324
 325 /*******************************************************************
 326  Create a NT token for the user, expanding local aliases
 327 *******************************************************************/
 328
 329 struct security_token *create_local_nt_token(TALLOC_CTX *mem_ctx,
 330                                             const struct dom_sid *user_sid,
 331                                             bool is_guest,
 332                                             int num_groupsids,
 333                                             const struct dom_sid *groupsids)
 334 {
 335         struct security_token *result = NULL;
 336         int i;
 337         NTSTATUS status;
 338
 339         DEBUG(10, ("Create local NT token for %s\n",
 340                    sid_string_dbg(user_sid)));
 341
 342         if (!(result = talloc_zero(mem_ctx, struct security_token))) {
 343                 DEBUG(0, ("talloc failed\n"));
 344                 return NULL;
 345         }
 346
 347         /* Add the user and primary group sid */
 348
 349         status = add_sid_to_array(result, user_sid,
 350                                   &result->sids, &result->num_sids);
 351         if (!NT_STATUS_IS_OK(status)) {
 352                 TALLOC_FREE(result);
 353                 return NULL;
 354         }
 355
 356         /* For guest, num_groupsids may be zero. */
 357         if (num_groupsids) {
 358                 status = add_sid_to_array(result, &groupsids[0],
 359                                           &result->sids,
 360                                           &result->num_sids);
 361                 if (!NT_STATUS_IS_OK(status)) {
 362                         TALLOC_FREE(result);
 363                         return NULL;
 364                 }
 365         }
 366
 367         /* Now the SIDs we got from authentication. These are the ones from
 368          * the info3 struct or from the pdb_enum_group_memberships, depending
 369          * on who authenticated the user.
 370          * Note that we start the for loop at "1" here, we already added the
 371          * first group sid as primary above. */
 372
 373         for (i=1; i<num_groupsids; i++) {
 374                 status = add_sid_to_array_unique(result, &groupsids[i],
 375                                                  &result->sids,
 376                                                  &result->num_sids);
 377                 if (!NT_STATUS_IS_OK(status)) {
 378                         TALLOC_FREE(result);
 379                         return NULL;
 380                 }
 381         }
 382
 383         status = finalize_local_nt_token(result, is_guest);
 384         if (!NT_STATUS_IS_OK(status)) {
 385                 TALLOC_FREE(result);
 386                 return NULL;
 387         }
 388
 389         return result;
 390 }
 391
 392 static NTSTATUS finalize_local_nt_token(struct security_token *result,
 393                                         bool is_guest)
 394 {
 395         struct dom_sid dom_sid;
 396         gid_t gid;
 397         NTSTATUS status;
 398
 399         /* Add in BUILTIN sids */
 400
 401         status = add_sid_to_array(result, &global_sid_World,
 402                                   &result->sids, &result->num_sids);
 403         if (!NT_STATUS_IS_OK(status)) {
 404                 return status;
 405         }
 406         status = add_sid_to_array(result, &global_sid_Network,
 407                                   &result->sids, &result->num_sids);
 408         if (!NT_STATUS_IS_OK(status)) {
 409                 return status;
 410         }
 411
 412         if (is_guest) {
 413                 status = add_sid_to_array(result, &global_sid_Builtin_Guests,
 414                                           &result->sids,
 415                                           &result->num_sids);
 416                 if (!NT_STATUS_IS_OK(status)) {
 417                         return status;
 418                 }
 419         } else {
 420                 status = add_sid_to_array(result,
 421                                           &global_sid_Authenticated_Users,
 422                                           &result->sids,
 423                                           &result->num_sids);
 424                 if (!NT_STATUS_IS_OK(status)) {
 425                         return status;
 426                 }
 427         }
 428
 429         /* Deal with the BUILTIN\Administrators group.  If the SID can
 430            be resolved then assume that the add_aliasmem( S-1-5-32 )
 431            handled it. */
 432
 433         if (!sid_to_gid(&global_sid_Builtin_Administrators, &gid)) {
 434
 435                 become_root();
 436                 if (!secrets_fetch_domain_sid(lp_workgroup(), &dom_sid)) {
 437                         status = NT_STATUS_OK;
 438                         DEBUG(3, ("Failed to fetch domain sid for %s\n",
 439                                   lp_workgroup()));
 440                 } else {
 441                         status = create_builtin_administrators(&dom_sid);
 442                 }
 443                 unbecome_root();
 444
 445                 if (NT_STATUS_EQUAL(status, NT_STATUS_PROTOCOL_UNREACHABLE)) {
 446                         /* Add BUILTIN\Administrators directly to token. */
 447                         status = add_builtin_administrators(result, &dom_sid);
 448                         if ( !NT_STATUS_IS_OK(status) ) {
 449                                 DEBUG(3, ("Failed to check for local "
 450                                           "Administrators membership (%s)\n",
 451                                           nt_errstr(status)));
 452                         }
 453                 } else if (!NT_STATUS_IS_OK(status)) {
 454                         DEBUG(2, ("WARNING: Failed to create "
 455                                   "BUILTIN\\Administrators group!  Can "
 456                                   "Winbind allocate gids?\n"));
 457                 }
 458         }
 459
 460         /* Deal with the BUILTIN\Users group.  If the SID can
 461            be resolved then assume that the add_aliasmem( S-1-5-32 )
 462            handled it. */
 463
 464         if (!sid_to_gid(&global_sid_Builtin_Users, &gid)) {
 465
 466                 become_root();
 467                 if (!secrets_fetch_domain_sid(lp_workgroup(), &dom_sid)) {
 468                         status = NT_STATUS_OK;
 469                         DEBUG(3, ("Failed to fetch domain sid for %s\n",
 470                                   lp_workgroup()));
 471                 } else {
 472                         status = create_builtin_users(&dom_sid);
 473                 }
 474                 unbecome_root();
 475
 476                 if (!NT_STATUS_EQUAL(status, NT_STATUS_PROTOCOL_UNREACHABLE) &&
 477                     !NT_STATUS_IS_OK(status))
 478                 {
 479                         DEBUG(2, ("WARNING: Failed to create BUILTIN\\Users group! "
 480                                   "Can Winbind allocate gids?\n"));
 481                 }
 482         }
 483
 484         /* Deal with local groups */
 485
 486         if (lp_winbind_nested_groups()) {
 487
 488                 become_root();
 489
 490                 /* Now add the aliases. First the one from our local SAM */
 491
 492                 status = add_aliases(get_global_sam_sid(), result);
 493
 494                 if (!NT_STATUS_IS_OK(status)) {
 495                         unbecome_root();
 496                         return status;
 497                 }
 498
 499                 /* Finally the builtin ones */
 500
 501                 status = add_aliases(&global_sid_Builtin, result);
 502
 503                 if (!NT_STATUS_IS_OK(status)) {
 504                         unbecome_root();
 505                         return status;
 506                 }
 507
 508                 unbecome_root();
 509         }
 510
 511         /* Add privileges based on current user sids */
 512
 513         get_privileges_for_sids(&result->privilege_mask, result->sids,
 514                                 result->num_sids);
 515
 516         return NT_STATUS_OK;
 517 }
 518
 519 /****************************************************************************
 520  prints a UNIX 'token' to debug output.
 521 ****************************************************************************/
 522
 523 void debug_unix_user_token(int dbg_class, int dbg_lev, uid_t uid, gid_t gid,
 524                            int n_groups, gid_t *groups)
 525 {
 526         int     i;
 527         DEBUGC(dbg_class, dbg_lev,
 528                ("UNIX token of user %ld\n", (long int)uid));
 529
 530         DEBUGADDC(dbg_class, dbg_lev,
 531                   ("Primary group is %ld and contains %i supplementary "
 532                    "groups\n", (long int)gid, n_groups));
 533         for (i = 0; i < n_groups; i++)
 534                 DEBUGADDC(dbg_class, dbg_lev, ("Group[%3i]: %ld\n", i,
 535                         (long int)groups[i]));
 536 }
 537
 538 /*
 539  * Create an artificial NT token given just a domain SID.
 540  *
 541  * We have 3 cases:
 542  *
 543  * unmapped unix users: Go directly to nss to find the user's group.
 544  *
 545  * A passdb user: The list of groups is provided by pdb_enum_group_memberships.
 546  *
 547  * If the user is provided by winbind, the primary gid is set to "domain
 548  * users" of the user's domain. For an explanation why this is necessary, see
 549  * the thread starting at
 550  * http://lists.samba.org/archive/samba-technical/2006-January/044803.html.
 551  */
 552
 553 static NTSTATUS create_token_from_sid(TALLOC_CTX *mem_ctx,
 554                                       const struct dom_sid *user_sid,
 555                                       bool is_guest,
 556                                       uid_t *uid, gid_t *gid,
 557                                       char **found_username,
 558                                       struct security_token **token)
 559 {
 560         NTSTATUS result = NT_STATUS_NO_SUCH_USER;
 561         TALLOC_CTX *tmp_ctx = talloc_stackframe();
 562         gid_t *gids;
 563         struct dom_sid *group_sids;
 564         struct dom_sid unix_group_sid;
 565         uint32_t num_group_sids;
 566         uint32_t num_gids;
 567         uint32_t i;
 568
 569         if (sid_check_is_in_our_sam(user_sid)) {
 570                 bool ret;
 571                 uint32_t pdb_num_group_sids;
 572                 /* This is a passdb user, so ask passdb */
 573
 574                 struct samu *sam_acct = NULL;
 575
 576                 if ( !(sam_acct = samu_new( tmp_ctx )) ) {
 577                         result = NT_STATUS_NO_MEMORY;
 578                         goto done;
 579                 }
 580
 581                 become_root();
 582                 ret = pdb_getsampwsid(sam_acct, user_sid);
 583                 unbecome_root();
 584
 585                 if (!ret) {
 586                         DEBUG(1, ("pdb_getsampwsid(%s) failed\n",
 587                                   sid_string_dbg(user_sid)));
 588                         DEBUGADD(1, ("Fall back to unix user\n"));
 589                         goto unix_user;
 590                 }
 591
 592                 result = pdb_enum_group_memberships(tmp_ctx, sam_acct,
 593                                                     &group_sids, &gids,
 594                                                     &pdb_num_group_sids);
 595                 if (!NT_STATUS_IS_OK(result)) {
 596                         DEBUG(1, ("enum_group_memberships failed for %s: "
 597                                   "%s\n", sid_string_dbg(user_sid),
 598                                   nt_errstr(result)));
 599                         DEBUGADD(1, ("Fall back to unix uid lookup\n"));
 600                         goto unix_user;
 601                 }
 602                 num_group_sids = pdb_num_group_sids;
 603
 604                 /* see the smb_panic() in pdb_default_enum_group_memberships */
 605                 SMB_ASSERT(num_group_sids > 0);
 606
 607                 *gid = gids[0];
 608
 609                 /* Ensure we're returning the found_username on the right context. */
 610                 *found_username = talloc_strdup(mem_ctx,
 611                                                 pdb_get_username(sam_acct));
 612
 613                 /*
 614                  * If the SID from lookup_name() was the guest sid, passdb knows
 615                  * about the mapping of guest sid to lp_guestaccount()
 616                  * username and will return the unix_pw info for a guest
 617                  * user. Use it if it's there, else lookup the *uid details
 618                  * using Get_Pwnam_alloc(). See bug #6291 for details. JRA.
 619                  */
 620
 621                 /* We must always assign the *uid. */
 622                 if (sam_acct->unix_pw == NULL) {
 623                         struct passwd *pwd = Get_Pwnam_alloc(sam_acct, *found_username );
 624                         if (!pwd) {
 625                                 DEBUG(10, ("Get_Pwnam_alloc failed for %s\n",
 626                                         *found_username));
 627                                 result = NT_STATUS_NO_SUCH_USER;
 628                                 goto done;
 629                         }
 630                         result = samu_set_unix(sam_acct, pwd );
 631                         if (!NT_STATUS_IS_OK(result)) {
 632                                 DEBUG(10, ("samu_set_unix failed for %s\n",
 633                                         *found_username));
 634                                 result = NT_STATUS_NO_SUCH_USER;
 635                                 goto done;
 636                         }
 637                 }
 638                 *uid = sam_acct->unix_pw->pw_uid;
 639
 640         } else  if (sid_check_is_in_unix_users(user_sid)) {
 641                 struct dom_sid tmp_sid;
 642                 uint32_t getgroups_num_group_sids;
 643                 /* This is a unix user not in passdb. We need to ask nss
 644                  * directly, without consulting passdb */
 645
 646                 struct passwd *pass;
 647
 648                 /*
 649                  * This goto target is used as a fallback for the passdb
 650                  * case. The concrete bug report is when passdb gave us an
 651                  * unmapped gid.
 652                  */
 653
 654         unix_user:
 655
 656                 if (!sid_to_uid(user_sid, uid)) {
 657                         DEBUG(1, ("unix_user case, sid_to_uid for %s failed\n",
 658                                   sid_string_dbg(user_sid)));
 659                         result = NT_STATUS_NO_SUCH_USER;
 660                         goto done;
 661                 }
 662
 663                 uid_to_unix_users_sid(*uid, &tmp_sid);
 664                 user_sid = &tmp_sid;
 665
 666                 pass = getpwuid_alloc(tmp_ctx, *uid);
 667                 if (pass == NULL) {
 668                         DEBUG(1, ("getpwuid(%u) failed\n",
 669                                   (unsigned int)*uid));
 670                         goto done;
 671                 }
 672
 673                 if (!getgroups_unix_user(tmp_ctx, pass->pw_name, pass->pw_gid,
 674                                          &gids, &getgroups_num_group_sids)) {
 675                         DEBUG(1, ("getgroups_unix_user for user %s failed\n",
 676                                   pass->pw_name));
 677                         goto done;
 678                 }
 679                 num_group_sids = getgroups_num_group_sids;
 680
 681                 if (num_group_sids) {
 682                         group_sids = talloc_array(tmp_ctx, struct dom_sid, num_group_sids);
 683                         if (group_sids == NULL) {
 684                                 DEBUG(1, ("talloc_array failed\n"));
 685                                 result = NT_STATUS_NO_MEMORY;
 686                                 goto done;
 687                         }
 688                 } else {
 689                         group_sids = NULL;
 690                 }
 691
 692                 for (i=0; i<num_group_sids; i++) {
 693                         gid_to_sid(&group_sids[i], gids[i]);
 694                 }
 695
 696                 /* In getgroups_unix_user we always set the primary gid */
 697                 SMB_ASSERT(num_group_sids > 0);
 698
 699                 *gid = gids[0];
 700
 701                 /* Ensure we're returning the found_username on the right context. */
 702                 *found_username = talloc_strdup(mem_ctx, pass->pw_name);
 703         } else {
 704
 705                 /* This user is from winbind, force the primary gid to the
 706                  * user's "domain users" group. Under certain circumstances
 707                  * (user comes from NT4), this might be a loss of
 708                  * information. But we can not rely on winbind getting the
 709                  * correct info. AD might prohibit winbind looking up that
 710                  * information. */
 711
 712                 /* We must always assign the *uid. */
 713                 if (!sid_to_uid(user_sid, uid)) {
 714                         DEBUG(1, ("winbindd case, sid_to_uid for %s failed\n",
 715                                   sid_string_dbg(user_sid)));
 716                         result = NT_STATUS_NO_SUCH_USER;
 717                         goto done;
 718                 }
 719
 720                 num_group_sids = 1;
 721                 group_sids = talloc_array(tmp_ctx, struct dom_sid, num_group_sids);
 722                 if (group_sids == NULL) {
 723                         DEBUG(1, ("talloc_array failed\n"));
 724                         result = NT_STATUS_NO_MEMORY;
 725                         goto done;
 726                 }
 727
 728                 sid_copy(&group_sids[0], user_sid);
 729                 sid_split_rid(&group_sids[0], NULL);
 730                 sid_append_rid(&group_sids[0], DOMAIN_RID_USERS);
 731
 732                 if (!sid_to_gid(&group_sids[0], gid)) {
 733                         DEBUG(1, ("sid_to_gid(%s) failed\n",
 734                                   sid_string_dbg(&group_sids[0])));
 735                         goto done;
 736                 }
 737
 738                 gids = gid;
 739
 740                 /* Ensure we're returning the found_username on the right context. */
 741                 *found_username = NULL;
 742         }
 743
 744         /* Add the "Unix Group" SID for each gid to catch mapped groups
 745            and their Unix equivalent.  This is to solve the backwards
 746            compatibility problem of 'valid users = +ntadmin' where
 747            ntadmin has been paired with "Domain Admins" in the group
 748            mapping table.  Otherwise smb.conf would need to be changed
 749            to 'valid user = "Domain Admins"'.  --jerry */
 750
 751         num_gids = num_group_sids;
 752         for ( i=0; i<num_gids; i++ ) {
 753                 gid_t high, low;
 754
 755                 /* don't pickup anything managed by Winbind */
 756
 757                 if ( lp_idmap_gid(&low, &high) && (gids[i] >= low) && (gids[i] <= high) )
 758                         continue;
 759
 760                 gid_to_unix_groups_sid(gids[i], &unix_group_sid);
 761
 762                 result = add_sid_to_array_unique(tmp_ctx, &unix_group_sid,
 763                                                  &group_sids, &num_group_sids);
 764                 if (!NT_STATUS_IS_OK(result)) {
 765                         goto done;
 766                 }
 767         }
 768
 769         /* Ensure we're creating the nt_token on the right context. */
 770         *token = create_local_nt_token(mem_ctx, user_sid,
 771                                        is_guest, num_group_sids, group_sids);
 772
 773         if ((*token == NULL) || (*found_username == NULL)) {
 774                 result = NT_STATUS_NO_MEMORY;
 775                 goto done;
 776         }
 777
 778         result = NT_STATUS_OK;
 779  done:
 780         TALLOC_FREE(tmp_ctx);
 781         return result;
 782 }
 783
 784 /*
 785  * Create an artificial NT token given just a username. (Initially intended
 786  * for force user)
 787  *
 788  * We go through lookup_name() to avoid problems we had with 'winbind use
 789  * default domain'.
 790  *
 791  * We have 3 cases:
 792  *
 793  * unmapped unix users: Go directly to nss to find the user's group.
 794  *
 795  * A passdb user: The list of groups is provided by pdb_enum_group_memberships.
 796  *
 797  * If the user is provided by winbind, the primary gid is set to "domain
 798  * users" of the user's domain. For an explanation why this is necessary, see
 799  * the thread starting at
 800  * http://lists.samba.org/archive/samba-technical/2006-January/044803.html.
 801  */
 802
 803 NTSTATUS create_token_from_username(TALLOC_CTX *mem_ctx, const char *username,
 804                                     bool is_guest,
 805                                     uid_t *uid, gid_t *gid,
 806                                     char **found_username,
 807                                     struct security_token **token)
 808 {
 809         NTSTATUS result = NT_STATUS_NO_SUCH_USER;
 810         TALLOC_CTX *tmp_ctx = talloc_stackframe();
 811         struct dom_sid user_sid;
 812         enum lsa_SidType type;
 813
 814         if (!lookup_name_smbconf(tmp_ctx, username, LOOKUP_NAME_ALL,
 815                          NULL, NULL, &user_sid, &type)) {
 816                 DEBUG(1, ("lookup_name_smbconf for %s failed\n", username));
 817                 goto done;
 818         }
 819
 820         if (type != SID_NAME_USER) {
 821                 DEBUG(1, ("%s is a %s, not a user\n", username,
 822                           sid_type_lookup(type)));
 823                 goto done;
 824         }
 825
 826         result = create_token_from_sid(mem_ctx, &user_sid, is_guest, uid, gid, found_username, token);
 827
 828         if (!NT_STATUS_IS_OK(result)) {
 829                 goto done;
 830         }
 831
 832         if (*found_username == NULL) {
 833                 *found_username = talloc_strdup(mem_ctx, username);
 834         }
 835
 836         if ((*token == NULL) || (*found_username == NULL)) {
 837                 result = NT_STATUS_NO_MEMORY;
 838                 goto done;
 839         }
 840
 841         result = NT_STATUS_OK;
 842 done:
 843         TALLOC_FREE(tmp_ctx);
 844         return result;
 845 }
 846
 847 /***************************************************************************
 848  Build upon create_token_from_username:
 849
 850  Expensive helper function to figure out whether a user given its name is
 851  member of a particular group.
 852 ***************************************************************************/
 853
 854 bool user_sid_in_group_sid(const struct dom_sid *sid, const struct dom_sid *group_sid)
 855 {
 856         NTSTATUS status;
 857         uid_t uid;
 858         gid_t gid;
 859         char *found_username;
 860         struct security_token *token;
 861         bool result;
 862         enum lsa_SidType type;
 863         TALLOC_CTX *mem_ctx = talloc_stackframe();
 864
 865         if (!lookup_sid(mem_ctx, sid,
 866                          NULL, NULL, &type)) {
 867                 DEBUG(1, ("lookup_sid for %s failed\n", dom_sid_string(mem_ctx, sid)));
 868                 goto done;
 869         }
 870
 871         if (type != SID_NAME_USER) {
 872                 DEBUG(5, ("%s is a %s, not a user\n", dom_sid_string(mem_ctx, sid),
 873                           sid_type_lookup(type)));
 874                 goto done;
 875         }
 876
 877         status = create_token_from_sid(mem_ctx, sid, False,
 878                                        &uid, &gid, &found_username,
 879                                        &token);
 880
 881         if (!NT_STATUS_IS_OK(status)) {
 882                 DEBUG(10, ("could not create token for %s\n", dom_sid_string(mem_ctx, sid)));
 883                 TALLOC_FREE(mem_ctx);
 884                 return False;
 885         }
 886
 887         result = security_token_has_sid(token, group_sid);
 888
 889 done:
 890         TALLOC_FREE(mem_ctx);
 891         return result;
 892 }
 893
 894 /***************************************************************************
 895  Build upon create_token_from_username:
 896
 897  Expensive helper function to figure out whether a user given its name is
 898  member of a particular group.
 899 ***************************************************************************/
 900
 901 bool user_in_group_sid(const char *username, const struct dom_sid *group_sid)
 902 {
 903         NTSTATUS status;
 904         uid_t uid;
 905         gid_t gid;
 906         char *found_username;
 907         struct security_token *token;
 908         bool result;
 909         TALLOC_CTX *mem_ctx = talloc_stackframe();
 910
 911         status = create_token_from_username(mem_ctx, username, False,
 912                                             &uid, &gid, &found_username,
 913                                             &token);
 914
 915         if (!NT_STATUS_IS_OK(status)) {
 916                 DEBUG(10, ("could not create token for %s\n", username));
 917                 TALLOC_FREE(mem_ctx);
 918                 return False;
 919         }
 920
 921         result = security_token_has_sid(token, group_sid);
 922
 923         TALLOC_FREE(mem_ctx);
 924         return result;
 925 }
 926
 927 bool user_in_group(const char *username, const char *groupname)
 928 {
 929         TALLOC_CTX *mem_ctx = talloc_stackframe();
 930         struct dom_sid group_sid;
 931         bool ret;
 932
 933         ret = lookup_name(mem_ctx, groupname, LOOKUP_NAME_ALL,
 934                           NULL, NULL, &group_sid, NULL);
 935         TALLOC_FREE(mem_ctx);
 936
 937         if (!ret) {
 938                 DEBUG(10, ("lookup_name for (%s) failed.\n", groupname));
 939                 return False;
 940         }
 941
 942         return user_in_group_sid(username, &group_sid);
 943 }
 944
 945 /* END */