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         static NT_USER_TOKEN *token = NULL;
  81         DOM_SID u_sid, g_sid;
  82         struct passwd *pw;
  83
  84         if ( token )
  85                 return token;
  86
  87         if ( !(pw = sys_getpwnam( "root" )) ) {
  88                 DEBUG(0,("get_root_nt_token: getpwnam\"root\") failed!\n"));
  89                 return NULL;
  90         }
  91
  92         /* get the user and primary group SIDs; although the
  93            BUILTIN\Administrators SId is really the one that matters here */
  94
  95         uid_to_sid(&u_sid, pw->pw_uid);
  96         gid_to_sid(&g_sid, pw->pw_gid);
  97
  98         token = create_local_nt_token(NULL, &u_sid, False,
  99                                       1, &global_sid_Builtin_Administrators);
 100         return token;
 101 }
 102
 103
 104 /*
 105  * Add alias SIDs from memberships within the partially created token SID list
 106  */
 107
 108 NTSTATUS add_aliases(const DOM_SID *domain_sid,
 109                      struct nt_user_token *token)
 110 {
 111         uint32 *aliases;
 112         size_t i, num_aliases;
 113         NTSTATUS status;
 114         TALLOC_CTX *tmp_ctx;
 115
 116         if (!(tmp_ctx = talloc_init("add_aliases"))) {
 117                 return NT_STATUS_NO_MEMORY;
 118         }
 119
 120         aliases = NULL;
 121         num_aliases = 0;
 122
 123         status = pdb_enum_alias_memberships(tmp_ctx, domain_sid,
 124                                             token->user_sids,
 125                                             token->num_sids,
 126                                             &aliases, &num_aliases);
 127
 128         if (!NT_STATUS_IS_OK(status)) {
 129                 DEBUG(10, ("pdb_enum_alias_memberships failed: %s\n",
 130                            nt_errstr(status)));
 131                 TALLOC_FREE(tmp_ctx);
 132                 return status;
 133         }
 134
 135         for (i=0; i<num_aliases; i++) {
 136                 DOM_SID alias_sid;
 137                 sid_compose(&alias_sid, domain_sid, aliases[i]);
 138                 if (!add_sid_to_array_unique(token, &alias_sid,
 139                                         &token->user_sids,
 140                                         &token->num_sids)) {
 141                         DEBUG(0, ("add_sid_to_array failed\n"));
 142                         TALLOC_FREE(tmp_ctx);
 143                         return NT_STATUS_NO_MEMORY;
 144                 }
 145         }
 146
 147         TALLOC_FREE(tmp_ctx);
 148         return NT_STATUS_OK;
 149 }
 150
 151 /*******************************************************************
 152 *******************************************************************/
 153
 154 static NTSTATUS add_builtin_administrators( struct nt_user_token *token )
 155 {
 156         DOM_SID domadm;
 157
 158         /* nothing to do if we aren't in a domain */
 159
 160         if ( !(IS_DC || lp_server_role()==ROLE_DOMAIN_MEMBER) ) {
 161                 return NT_STATUS_OK;
 162         }
 163
 164         /* Find the Domain Admins SID */
 165
 166         if ( IS_DC ) {
 167                 sid_copy( &domadm, get_global_sam_sid() );
 168         } else {
 169                 if ( !secrets_fetch_domain_sid( lp_workgroup(), &domadm ) )
 170                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 171         }
 172         sid_append_rid( &domadm, DOMAIN_GROUP_RID_ADMINS );
 173
 174         /* Add Administrators if the user beloongs to Domain Admins */
 175
 176         if ( nt_token_check_sid( &domadm, token ) ) {
 177                 if (!add_sid_to_array(token, &global_sid_Builtin_Administrators,
 178                                          &token->user_sids, &token->num_sids)) {
 179                         return NT_STATUS_NO_MEMORY;
 180                 }
 181         }
 182
 183         return NT_STATUS_OK;
 184 }
 185
 186 /*******************************************************************
 187 *******************************************************************/
 188
 189 static NTSTATUS create_builtin_users( void )
 190 {
 191         NTSTATUS status;
 192         DOM_SID dom_users;
 193
 194         status = pdb_create_builtin_alias( BUILTIN_ALIAS_RID_USERS );
 195         if ( !NT_STATUS_IS_OK(status) ) {
 196                 DEBUG(0,("create_builtin_users: Failed to create Users\n"));
 197                 return status;
 198         }
 199
 200         /* add domain users */
 201         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 202                 && secrets_fetch_domain_sid(lp_workgroup(), &dom_users))
 203         {
 204                 sid_append_rid(&dom_users, DOMAIN_GROUP_RID_USERS );
 205                 status = pdb_add_aliasmem( &global_sid_Builtin_Users, &dom_users);
 206                 if ( !NT_STATUS_IS_OK(status) ) {
 207                         DEBUG(0,("create_builtin_administrators: Failed to add Domain Users to"
 208                                 " Users\n"));
 209                         return status;
 210                 }
 211         }
 212
 213         return NT_STATUS_OK;
 214 }
 215
 216 /*******************************************************************
 217 *******************************************************************/
 218
 219 static NTSTATUS create_builtin_administrators( void )
 220 {
 221         NTSTATUS status;
 222         DOM_SID dom_admins, root_sid;
 223         fstring root_name;
 224         enum lsa_SidType type;
 225         TALLOC_CTX *ctx;
 226         BOOL ret;
 227
 228         status = pdb_create_builtin_alias( BUILTIN_ALIAS_RID_ADMINS );
 229         if ( !NT_STATUS_IS_OK(status) ) {
 230                 DEBUG(0,("create_builtin_administrators: Failed to create Administrators\n"));
 231                 return status;
 232         }
 233
 234         /* add domain admins */
 235         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 236                 && secrets_fetch_domain_sid(lp_workgroup(), &dom_admins))
 237         {
 238                 sid_append_rid(&dom_admins, DOMAIN_GROUP_RID_ADMINS);
 239                 status = pdb_add_aliasmem( &global_sid_Builtin_Administrators, &dom_admins );
 240                 if ( !NT_STATUS_IS_OK(status) ) {
 241                         DEBUG(0,("create_builtin_administrators: Failed to add Domain Admins"
 242                                 " Administrators\n"));
 243                         return status;
 244                 }
 245         }
 246
 247         /* add root */
 248         if ( (ctx = talloc_init("create_builtin_administrators")) == NULL ) {
 249                 return NT_STATUS_NO_MEMORY;
 250         }
 251         fstr_sprintf( root_name, "%s\\root", get_global_sam_name() );
 252         ret = lookup_name( ctx, root_name, 0, NULL, NULL, &root_sid, &type );
 253         TALLOC_FREE( ctx );
 254
 255         if ( ret ) {
 256                 status = pdb_add_aliasmem( &global_sid_Builtin_Administrators, &root_sid );
 257                 if ( !NT_STATUS_IS_OK(status) ) {
 258                         DEBUG(0,("create_builtin_administrators: Failed to add root"
 259                                 " Administrators\n"));
 260                         return status;
 261                 }
 262         }
 263
 264         return NT_STATUS_OK;
 265 }
 266
 267
 268 /*******************************************************************
 269  Create a NT token for the user, expanding local aliases
 270 *******************************************************************/
 271
 272 struct nt_user_token *create_local_nt_token(TALLOC_CTX *mem_ctx,
 273                                             const DOM_SID *user_sid,
 274                                             BOOL is_guest,
 275                                             int num_groupsids,
 276                                             const DOM_SID *groupsids)
 277 {
 278         struct nt_user_token *result = NULL;
 279         int i;
 280         NTSTATUS status;
 281         gid_t gid;
 282
 283         DEBUG(10, ("Create local NT token for %s\n", sid_string_static(user_sid)));
 284
 285         if (!(result = TALLOC_ZERO_P(mem_ctx, NT_USER_TOKEN))) {
 286                 DEBUG(0, ("talloc failed\n"));
 287                 return NULL;
 288         }
 289
 290         /* Add the user and primary group sid */
 291
 292         if (!add_sid_to_array(result, user_sid,
 293                          &result->user_sids, &result->num_sids)) {
 294                 return NULL;
 295         }
 296
 297         /* For guest, num_groupsids may be zero. */
 298         if (num_groupsids) {
 299                 if (!add_sid_to_array(result, &groupsids[0],
 300                                  &result->user_sids, &result->num_sids)) {
 301                         return NULL;
 302                 }
 303         }
 304
 305         /* Add in BUILTIN sids */
 306
 307         if (!add_sid_to_array(result, &global_sid_World,
 308                          &result->user_sids, &result->num_sids)) {
 309                 return NULL;
 310         }
 311         if (!add_sid_to_array(result, &global_sid_Network,
 312                          &result->user_sids, &result->num_sids)) {
 313                 return NULL;
 314         }
 315
 316         if (is_guest) {
 317                 if (!add_sid_to_array(result, &global_sid_Builtin_Guests,
 318                                  &result->user_sids, &result->num_sids)) {
 319                         return NULL;
 320                 }
 321         } else {
 322                 if (!add_sid_to_array(result, &global_sid_Authenticated_Users,
 323                                  &result->user_sids, &result->num_sids)) {
 324                         return NULL;
 325                 }
 326         }
 327
 328         /* Now the SIDs we got from authentication. These are the ones from
 329          * the info3 struct or from the pdb_enum_group_memberships, depending
 330          * on who authenticated the user.
 331          * Note that we start the for loop at "1" here, we already added the
 332          * first group sid as primary above. */
 333
 334         for (i=1; i<num_groupsids; i++) {
 335                 if (!add_sid_to_array_unique(result, &groupsids[i],
 336                                         &result->user_sids, &result->num_sids)) {
 337                         return NULL;
 338                 }
 339         }
 340
 341         /* Deal with the BUILTIN\Administrators group.  If the SID can
 342            be resolved then assume that the add_aliasmem( S-1-5-32 )
 343            handled it. */
 344
 345         if ( !sid_to_gid( &global_sid_Builtin_Administrators, &gid ) ) {
 346                 /* We can only create a mapping if winbind is running
 347                    and the nested group functionality has been enabled */
 348
 349                 if ( lp_winbind_nested_groups() && winbind_ping() ) {
 350                         become_root();
 351                         status = create_builtin_administrators( );
 352                         if ( !NT_STATUS_IS_OK(status) ) {
 353                                 DEBUG(2,("create_local_nt_token: Failed to create BUILTIN\\Administrators group!\n"));
 354                                 /* don't fail, just log the message */
 355                         }
 356                         unbecome_root();
 357                 }
 358                 else {
 359                         status = add_builtin_administrators( result );
 360                         if ( !NT_STATUS_IS_OK(status) ) {
 361                                 /* just log a complaint but do not fail */
 362                                 DEBUG(3,("create_local_nt_token: failed to check for local Administrators"
 363                                         " membership (%s)\n", nt_errstr(status)));
 364                         }
 365                 }
 366         }
 367
 368         /* Deal with the BUILTIN\Users group.  If the SID can
 369            be resolved then assume that the add_aliasmem( S-1-5-32 )
 370            handled it. */
 371
 372         if ( !sid_to_gid( &global_sid_Builtin_Users, &gid ) ) {
 373                 /* We can only create a mapping if winbind is running
 374                    and the nested group functionality has been enabled */
 375
 376                 if ( lp_winbind_nested_groups() && winbind_ping() ) {
 377                         become_root();
 378                         status = create_builtin_users( );
 379                         if ( !NT_STATUS_IS_OK(status) ) {
 380                                 DEBUG(2,("create_local_nt_token: Failed to create BUILTIN\\Users group!\n"));
 381                                 /* don't fail, just log the message */
 382                         }
 383                         unbecome_root();
 384                 }
 385         }
 386
 387         /* Deal with local groups */
 388
 389         if (lp_winbind_nested_groups()) {
 390
 391                 /* Now add the aliases. First the one from our local SAM */
 392
 393                 status = add_aliases(get_global_sam_sid(), result);
 394
 395                 if (!NT_STATUS_IS_OK(status)) {
 396                         TALLOC_FREE(result);
 397                         return NULL;
 398                 }
 399
 400                 /* Finally the builtin ones */
 401
 402                 status = add_aliases(&global_sid_Builtin, result);
 403
 404                 if (!NT_STATUS_IS_OK(status)) {
 405                         TALLOC_FREE(result);
 406                         return NULL;
 407                 }
 408         }
 409
 410
 411         get_privileges_for_sids(&result->privileges, result->user_sids,
 412                                 result->num_sids);
 413         return result;
 414 }
 415
 416 /****************************************************************************
 417  prints a NT_USER_TOKEN to debug output.
 418 ****************************************************************************/
 419
 420 void debug_nt_user_token(int dbg_class, int dbg_lev, NT_USER_TOKEN *token)
 421 {
 422         size_t     i;
 423
 424         if (!token) {
 425                 DEBUGC(dbg_class, dbg_lev, ("NT user token: (NULL)\n"));
 426                 return;
 427         }
 428
 429         DEBUGC(dbg_class, dbg_lev,
 430                ("NT user token of user %s\n",
 431                 sid_string_static(&token->user_sids[0]) ));
 432         DEBUGADDC(dbg_class, dbg_lev,
 433                   ("contains %lu SIDs\n", (unsigned long)token->num_sids));
 434         for (i = 0; i < token->num_sids; i++)
 435                 DEBUGADDC(dbg_class, dbg_lev,
 436                           ("SID[%3lu]: %s\n", (unsigned long)i,
 437                            sid_string_static(&token->user_sids[i])));
 438
 439         dump_se_priv( dbg_class, dbg_lev, &token->privileges );
 440 }
 441
 442 /****************************************************************************
 443  prints a UNIX 'token' to debug output.
 444 ****************************************************************************/
 445
 446 void debug_unix_user_token(int dbg_class, int dbg_lev, uid_t uid, gid_t gid,
 447                            int n_groups, gid_t *groups)
 448 {
 449         int     i;
 450         DEBUGC(dbg_class, dbg_lev,
 451                ("UNIX token of user %ld\n", (long int)uid));
 452
 453         DEBUGADDC(dbg_class, dbg_lev,
 454                   ("Primary group is %ld and contains %i supplementary "
 455                    "groups\n", (long int)gid, n_groups));
 456         for (i = 0; i < n_groups; i++)
 457                 DEBUGADDC(dbg_class, dbg_lev, ("Group[%3i]: %ld\n", i,
 458                         (long int)groups[i]));
 459 }
 460
 461 /* END */