source/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 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         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 = NULL;
  81         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("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_getpwnam( "root" )) ) {
  95                 DEBUG(0,("get_root_nt_token: getpwnam(\"root\") failed!\n"));
  96                 return NULL;
  97         }
  98
  99         /* get the user and primary group SIDs; although the
 100            BUILTIN\Administrators SId is really the one that matters here */
 101
 102         uid_to_sid(&u_sid, pw->pw_uid);
 103         gid_to_sid(&g_sid, pw->pw_gid);
 104
 105         token = create_local_nt_token(NULL, &u_sid, False,
 106                                       1, &global_sid_Builtin_Administrators);
 107
 108         token->privileges = se_disk_operators;
 109
 110         memcache_add_talloc(
 111                 NULL, SINGLETON_CACHE_TALLOC,
 112                 data_blob_string_const("root_nt_token"), token);
 113
 114         return token;
 115 }
 116
 117
 118 /*
 119  * Add alias SIDs from memberships within the partially created token SID list
 120  */
 121
 122 NTSTATUS add_aliases(const DOM_SID *domain_sid,
 123                      struct nt_user_token *token)
 124 {
 125         uint32 *aliases;
 126         size_t i, num_aliases;
 127         NTSTATUS status;
 128         TALLOC_CTX *tmp_ctx;
 129
 130         if (!(tmp_ctx = talloc_init("add_aliases"))) {
 131                 return NT_STATUS_NO_MEMORY;
 132         }
 133
 134         aliases = NULL;
 135         num_aliases = 0;
 136
 137         status = pdb_enum_alias_memberships(tmp_ctx, domain_sid,
 138                                             token->user_sids,
 139                                             token->num_sids,
 140                                             &aliases, &num_aliases);
 141
 142         if (!NT_STATUS_IS_OK(status)) {
 143                 DEBUG(10, ("pdb_enum_alias_memberships failed: %s\n",
 144                            nt_errstr(status)));
 145                 goto done;
 146         }
 147
 148         for (i=0; i<num_aliases; i++) {
 149                 DOM_SID alias_sid;
 150                 sid_compose(&alias_sid, domain_sid, aliases[i]);
 151                 status = add_sid_to_array_unique(token, &alias_sid,
 152                                                  &token->user_sids,
 153                                                  &token->num_sids);
 154                 if (!NT_STATUS_IS_OK(status)) {
 155                         DEBUG(0, ("add_sid_to_array failed\n"));
 156                         goto done;
 157                 }
 158         }
 159
 160 done:
 161         TALLOC_FREE(tmp_ctx);
 162         return NT_STATUS_OK;
 163 }
 164
 165 /*******************************************************************
 166 *******************************************************************/
 167
 168 static NTSTATUS add_builtin_administrators( struct nt_user_token *token )
 169 {
 170         DOM_SID domadm;
 171         NTSTATUS status;
 172
 173         /* nothing to do if we aren't in a domain */
 174
 175         if ( !(IS_DC || lp_server_role()==ROLE_DOMAIN_MEMBER) ) {
 176                 return NT_STATUS_OK;
 177         }
 178
 179         /* Find the Domain Admins SID */
 180
 181         if ( IS_DC ) {
 182                 sid_copy( &domadm, get_global_sam_sid() );
 183         } else {
 184                 if ( !secrets_fetch_domain_sid( lp_workgroup(), &domadm ) )
 185                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 186         }
 187         sid_append_rid( &domadm, DOMAIN_GROUP_RID_ADMINS );
 188
 189         /* Add Administrators if the user beloongs to Domain Admins */
 190
 191         if ( nt_token_check_sid( &domadm, token ) ) {
 192                 status = add_sid_to_array(token,
 193                                           &global_sid_Builtin_Administrators,
 194                                           &token->user_sids, &token->num_sids);
 195         if (!NT_STATUS_IS_OK(status)) {
 196                         return status;
 197                 }
 198         }
 199
 200         return NT_STATUS_OK;
 201 }
 202
 203 /*******************************************************************
 204 *******************************************************************/
 205
 206 static NTSTATUS create_builtin_users( void )
 207 {
 208         NTSTATUS status;
 209         DOM_SID dom_users;
 210
 211         status = pdb_create_builtin_alias( BUILTIN_ALIAS_RID_USERS );
 212         if ( !NT_STATUS_IS_OK(status) ) {
 213                 DEBUG(5,("create_builtin_users: Failed to create Users\n"));
 214                 return status;
 215         }
 216
 217         /* add domain users */
 218         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 219                 && secrets_fetch_domain_sid(lp_workgroup(), &dom_users))
 220         {
 221                 sid_append_rid(&dom_users, DOMAIN_GROUP_RID_USERS );
 222                 status = pdb_add_aliasmem( &global_sid_Builtin_Users, &dom_users);
 223                 if ( !NT_STATUS_IS_OK(status) ) {
 224                         DEBUG(4,("create_builtin_administrators: Failed to add Domain Users to"
 225                                 " Users\n"));
 226                         return status;
 227                 }
 228         }
 229
 230         return NT_STATUS_OK;
 231 }
 232
 233 /*******************************************************************
 234 *******************************************************************/
 235
 236 static NTSTATUS create_builtin_administrators( void )
 237 {
 238         NTSTATUS status;
 239         DOM_SID dom_admins, root_sid;
 240         fstring root_name;
 241         enum lsa_SidType type;
 242         TALLOC_CTX *ctx;
 243         bool ret;
 244
 245         status = pdb_create_builtin_alias( BUILTIN_ALIAS_RID_ADMINS );
 246         if ( !NT_STATUS_IS_OK(status) ) {
 247                 DEBUG(5,("create_builtin_administrators: Failed to create Administrators\n"));
 248                 return status;
 249         }
 250
 251         /* add domain admins */
 252         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 253                 && secrets_fetch_domain_sid(lp_workgroup(), &dom_admins))
 254         {
 255                 sid_append_rid(&dom_admins, DOMAIN_GROUP_RID_ADMINS);
 256                 status = pdb_add_aliasmem( &global_sid_Builtin_Administrators, &dom_admins );
 257                 if ( !NT_STATUS_IS_OK(status) ) {
 258                         DEBUG(4,("create_builtin_administrators: Failed to add Domain Admins"
 259                                 " Administrators\n"));
 260                         return status;
 261                 }
 262         }
 263
 264         /* add root */
 265         if ( (ctx = talloc_init("create_builtin_administrators")) == NULL ) {
 266                 return NT_STATUS_NO_MEMORY;
 267         }
 268         fstr_sprintf( root_name, "%s\\root", get_global_sam_name() );
 269         ret = lookup_name(ctx, root_name, LOOKUP_NAME_DOMAIN, NULL, NULL,
 270                           &root_sid, &type);
 271         TALLOC_FREE( ctx );
 272
 273         if ( ret ) {
 274                 status = pdb_add_aliasmem( &global_sid_Builtin_Administrators, &root_sid );
 275                 if ( !NT_STATUS_IS_OK(status) ) {
 276                         DEBUG(4,("create_builtin_administrators: Failed to add root"
 277                                 " Administrators\n"));
 278                         return status;
 279                 }
 280         }
 281
 282         return NT_STATUS_OK;
 283 }
 284
 285
 286 /*******************************************************************
 287  Create a NT token for the user, expanding local aliases
 288 *******************************************************************/
 289
 290 struct nt_user_token *create_local_nt_token(TALLOC_CTX *mem_ctx,
 291                                             const DOM_SID *user_sid,
 292                                             bool is_guest,
 293                                             int num_groupsids,
 294                                             const DOM_SID *groupsids)
 295 {
 296         struct nt_user_token *result = NULL;
 297         int i;
 298         NTSTATUS status;
 299         gid_t gid;
 300
 301         DEBUG(10, ("Create local NT token for %s\n",
 302                    sid_string_dbg(user_sid)));
 303
 304         if (!(result = TALLOC_ZERO_P(mem_ctx, struct nt_user_token))) {
 305                 DEBUG(0, ("talloc failed\n"));
 306                 return NULL;
 307         }
 308
 309         /* Add the user and primary group sid */
 310
 311         status = add_sid_to_array(result, user_sid,
 312                                   &result->user_sids, &result->num_sids);
 313         if (!NT_STATUS_IS_OK(status)) {
 314                 return NULL;
 315         }
 316
 317         /* For guest, num_groupsids may be zero. */
 318         if (num_groupsids) {
 319                 status = add_sid_to_array(result, &groupsids[0],
 320                                           &result->user_sids,
 321                                           &result->num_sids);
 322                 if (!NT_STATUS_IS_OK(status)) {
 323                         return NULL;
 324                 }
 325         }
 326
 327         /* Add in BUILTIN sids */
 328
 329         status = add_sid_to_array(result, &global_sid_World,
 330                                   &result->user_sids, &result->num_sids);
 331         if (!NT_STATUS_IS_OK(status)) {
 332                 return NULL;
 333         }
 334         status = add_sid_to_array(result, &global_sid_Network,
 335                                   &result->user_sids, &result->num_sids);
 336         if (!NT_STATUS_IS_OK(status)) {
 337                 return NULL;
 338         }
 339
 340         if (is_guest) {
 341                 status = add_sid_to_array(result, &global_sid_Builtin_Guests,
 342                                           &result->user_sids,
 343                                           &result->num_sids);
 344                 if (!NT_STATUS_IS_OK(status)) {
 345                         return NULL;
 346                 }
 347         } else {
 348                 status = add_sid_to_array(result,
 349                                           &global_sid_Authenticated_Users,
 350                                           &result->user_sids,
 351                                           &result->num_sids);
 352                 if (!NT_STATUS_IS_OK(status)) {
 353                         return NULL;
 354                 }
 355         }
 356
 357         /* Now the SIDs we got from authentication. These are the ones from
 358          * the info3 struct or from the pdb_enum_group_memberships, depending
 359          * on who authenticated the user.
 360          * Note that we start the for loop at "1" here, we already added the
 361          * first group sid as primary above. */
 362
 363         for (i=1; i<num_groupsids; i++) {
 364                 status = add_sid_to_array_unique(result, &groupsids[i],
 365                                                  &result->user_sids,
 366                                                  &result->num_sids);
 367                 if (!NT_STATUS_IS_OK(status)) {
 368                         return NULL;
 369                 }
 370         }
 371
 372         /* Deal with the BUILTIN\Administrators group.  If the SID can
 373            be resolved then assume that the add_aliasmem( S-1-5-32 )
 374            handled it. */
 375
 376         if ( !sid_to_gid( &global_sid_Builtin_Administrators, &gid ) ) {
 377                 /* We can only create a mapping if winbind is running
 378                    and the nested group functionality has been enabled */
 379
 380                 if ( lp_winbind_nested_groups() && winbind_ping() ) {
 381                         become_root();
 382                         status = create_builtin_administrators( );
 383                         if ( !NT_STATUS_IS_OK(status) ) {
 384                                 DEBUG(2,("WARNING: Failed to create BUILTIN\\Administrators "
 385                                          "group!  Can Winbind allocate gids?\n"));
 386                                 /* don't fail, just log the message */
 387                         }
 388                         unbecome_root();
 389                 }
 390                 else {
 391                         status = add_builtin_administrators( result );
 392                         if ( !NT_STATUS_IS_OK(status) ) {
 393                                 /* just log a complaint but do not fail */
 394                                 DEBUG(3,("create_local_nt_token: failed to check for local Administrators"
 395                                         " membership (%s)\n", nt_errstr(status)));
 396                         }
 397                 }
 398         }
 399
 400         /* Deal with the BUILTIN\Users group.  If the SID can
 401            be resolved then assume that the add_aliasmem( S-1-5-32 )
 402            handled it. */
 403
 404         if ( !sid_to_gid( &global_sid_Builtin_Users, &gid ) ) {
 405                 /* We can only create a mapping if winbind is running
 406                    and the nested group functionality has been enabled */
 407
 408                 if ( lp_winbind_nested_groups() && winbind_ping() ) {
 409                         become_root();
 410                         status = create_builtin_users( );
 411                         if ( !NT_STATUS_IS_OK(status) ) {
 412                                 DEBUG(2,("WARNING: Failed to create BUILTIN\\Users group! "
 413                                          "Can Winbind allocate gids?\n"));
 414                                 /* don't fail, just log the message */
 415                         }
 416                         unbecome_root();
 417                 }
 418         }
 419
 420         /* Deal with local groups */
 421
 422         if (lp_winbind_nested_groups()) {
 423
 424                 become_root();
 425
 426                 /* Now add the aliases. First the one from our local SAM */
 427
 428                 status = add_aliases(get_global_sam_sid(), result);
 429
 430                 if (!NT_STATUS_IS_OK(status)) {
 431                         unbecome_root();
 432                         TALLOC_FREE(result);
 433                         return NULL;
 434                 }
 435
 436                 /* Finally the builtin ones */
 437
 438                 status = add_aliases(&global_sid_Builtin, result);
 439
 440                 if (!NT_STATUS_IS_OK(status)) {
 441                         unbecome_root();
 442                         TALLOC_FREE(result);
 443                         return NULL;
 444                 }
 445
 446                 unbecome_root();
 447         }
 448
 449
 450         get_privileges_for_sids(&result->privileges, result->user_sids,
 451                                 result->num_sids);
 452         return result;
 453 }
 454
 455 /****************************************************************************
 456  prints a NT_USER_TOKEN to debug output.
 457 ****************************************************************************/
 458
 459 void debug_nt_user_token(int dbg_class, int dbg_lev, NT_USER_TOKEN *token)
 460 {
 461         size_t     i;
 462
 463         if (!token) {
 464                 DEBUGC(dbg_class, dbg_lev, ("NT user token: (NULL)\n"));
 465                 return;
 466         }
 467
 468         DEBUGC(dbg_class, dbg_lev,
 469                ("NT user token of user %s\n",
 470                 sid_string_dbg(&token->user_sids[0]) ));
 471         DEBUGADDC(dbg_class, dbg_lev,
 472                   ("contains %lu SIDs\n", (unsigned long)token->num_sids));
 473         for (i = 0; i < token->num_sids; i++)
 474                 DEBUGADDC(dbg_class, dbg_lev,
 475                           ("SID[%3lu]: %s\n", (unsigned long)i,
 476                            sid_string_dbg(&token->user_sids[i])));
 477
 478         dump_se_priv( dbg_class, dbg_lev, &token->privileges );
 479 }
 480
 481 /****************************************************************************
 482  prints a UNIX 'token' to debug output.
 483 ****************************************************************************/
 484
 485 void debug_unix_user_token(int dbg_class, int dbg_lev, uid_t uid, gid_t gid,
 486                            int n_groups, gid_t *groups)
 487 {
 488         int     i;
 489         DEBUGC(dbg_class, dbg_lev,
 490                ("UNIX token of user %ld\n", (long int)uid));
 491
 492         DEBUGADDC(dbg_class, dbg_lev,
 493                   ("Primary group is %ld and contains %i supplementary "
 494                    "groups\n", (long int)gid, n_groups));
 495         for (i = 0; i < n_groups; i++)
 496                 DEBUGADDC(dbg_class, dbg_lev, ("Group[%3i]: %ld\n", i,
 497                         (long int)groups[i]));
 498 }
 499
 500 /* END */