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 2 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, write to the Free Software
  23  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 /* functions moved from auth/auth_util.c to minimize linker deps */
  27
  28 #include "includes.h"
  29
  30 /****************************************************************************
  31  Check for a SID in an NT_USER_TOKEN
  32 ****************************************************************************/
  33
  34 BOOL nt_token_check_sid ( const DOM_SID *sid, const NT_USER_TOKEN *token )
  35 {
  36         int i;
  37
  38         if ( !sid || !token )
  39                 return False;
  40
  41         for ( i=0; i<token->num_sids; i++ ) {
  42                 if ( sid_equal( sid, &token->user_sids[i] ) )
  43                         return True;
  44         }
  45
  46         return False;
  47 }
  48
  49 BOOL nt_token_check_domain_rid( NT_USER_TOKEN *token, uint32 rid )
  50 {
  51         DOM_SID domain_sid;
  52
  53         /* if we are a domain member, the get the domain SID, else for
  54            a DC or standalone server, use our own SID */
  55
  56         if ( lp_server_role() == ROLE_DOMAIN_MEMBER ) {
  57                 if ( !secrets_fetch_domain_sid( lp_workgroup(),
  58                                                 &domain_sid ) ) {
  59                         DEBUG(1,("nt_token_check_domain_rid: Cannot lookup "
  60                                  "SID for domain [%s]\n", lp_workgroup()));
  61                         return False;
  62                 }
  63         }
  64         else
  65                 sid_copy( &domain_sid, get_global_sam_sid() );
  66
  67         sid_append_rid( &domain_sid, rid );
  68
  69         return nt_token_check_sid( &domain_sid, token );\
  70 }
  71
  72 /******************************************************************************
  73  Create a token for the root user to be used internally by smbd.
  74  This is similar to running under the context of the LOCAL_SYSTEM account
  75  in Windows.  This is a read-only token.  Do not modify it or free() it.
  76  Create a copy if your need to change it.
  77 ******************************************************************************/
  78
  79 NT_USER_TOKEN *get_root_nt_token( void )
  80 {
  81         static NT_USER_TOKEN *token = NULL;
  82         DOM_SID u_sid, g_sid;
  83         struct passwd *pw;
  84
  85         if ( token )
  86                 return token;
  87
  88         if ( !(pw = sys_getpwnam( "root" )) ) {
  89                 DEBUG(0,("get_root_nt_token: getpwnam\"root\") failed!\n"));
  90                 return NULL;
  91         }
  92
  93         /* get the user and primary group SIDs; although the
  94            BUILTIN\Administrators SId is really the one that matters here */
  95
  96         uid_to_sid(&u_sid, pw->pw_uid);
  97         gid_to_sid(&g_sid, pw->pw_gid);
  98
  99         token = create_local_nt_token(NULL, &u_sid, False,
 100                                       1, &global_sid_Builtin_Administrators);
 101         return token;
 102 }
 103
 104
 105 /*
 106  * Add alias SIDs from memberships within the partially created token SID list
 107  */
 108
 109 NTSTATUS add_aliases(const DOM_SID *domain_sid,
 110                      struct nt_user_token *token)
 111 {
 112         uint32 *aliases;
 113         size_t i, num_aliases;
 114         NTSTATUS status;
 115         TALLOC_CTX *tmp_ctx;
 116
 117         if (!(tmp_ctx = talloc_init("add_aliases"))) {
 118                 return NT_STATUS_NO_MEMORY;
 119         }
 120
 121         aliases = NULL;
 122         num_aliases = 0;
 123
 124         status = pdb_enum_alias_memberships(tmp_ctx, domain_sid,
 125                                             token->user_sids,
 126                                             token->num_sids,
 127                                             &aliases, &num_aliases);
 128
 129         if (!NT_STATUS_IS_OK(status)) {
 130                 DEBUG(10, ("pdb_enum_alias_memberships failed: %s\n",
 131                            nt_errstr(status)));
 132                 TALLOC_FREE(tmp_ctx);
 133                 return status;
 134         }
 135
 136         for (i=0; i<num_aliases; i++) {
 137                 DOM_SID alias_sid;
 138                 sid_compose(&alias_sid, domain_sid, aliases[i]);
 139                 if (!add_sid_to_array_unique(token, &alias_sid,
 140                                         &token->user_sids,
 141                                         &token->num_sids)) {
 142                         DEBUG(0, ("add_sid_to_array failed\n"));
 143                         TALLOC_FREE(tmp_ctx);
 144                         return NT_STATUS_NO_MEMORY;
 145                 }
 146         }
 147
 148         TALLOC_FREE(tmp_ctx);
 149         return NT_STATUS_OK;
 150 }
 151
 152 /*******************************************************************
 153 *******************************************************************/
 154
 155 static NTSTATUS add_builtin_administrators( struct nt_user_token *token )
 156 {
 157         DOM_SID domadm;
 158
 159         /* nothing to do if we aren't in a domain */
 160
 161         if ( !(IS_DC || lp_server_role()==ROLE_DOMAIN_MEMBER) ) {
 162                 return NT_STATUS_OK;
 163         }
 164
 165         /* Find the Domain Admins SID */
 166
 167         if ( IS_DC ) {
 168                 sid_copy( &domadm, get_global_sam_sid() );
 169         } else {
 170                 if ( !secrets_fetch_domain_sid( lp_workgroup(), &domadm ) )
 171                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 172         }
 173         sid_append_rid( &domadm, DOMAIN_GROUP_RID_ADMINS );
 174
 175         /* Add Administrators if the user beloongs to Domain Admins */
 176
 177         if ( nt_token_check_sid( &domadm, token ) ) {
 178                 if (!add_sid_to_array(token, &global_sid_Builtin_Administrators,
 179                                          &token->user_sids, &token->num_sids)) {
 180                         return NT_STATUS_NO_MEMORY;
 181                 }
 182         }
 183
 184         return NT_STATUS_OK;
 185 }
 186
 187 /*******************************************************************
 188 *******************************************************************/
 189
 190 static NTSTATUS create_builtin_users( void )
 191 {
 192         NTSTATUS status;
 193         DOM_SID dom_users;
 194
 195         status = pdb_create_builtin_alias( BUILTIN_ALIAS_RID_USERS );
 196         if ( !NT_STATUS_IS_OK(status) ) {
 197                 DEBUG(0,("create_builtin_users: Failed to create Users\n"));
 198                 return status;
 199         }
 200
 201         /* add domain users */
 202         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 203                 && secrets_fetch_domain_sid(lp_workgroup(), &dom_users))
 204         {
 205                 sid_append_rid(&dom_users, DOMAIN_GROUP_RID_USERS );
 206                 status = pdb_add_aliasmem( &global_sid_Builtin_Users, &dom_users);
 207                 if ( !NT_STATUS_IS_OK(status) ) {
 208                         DEBUG(0,("create_builtin_administrators: Failed to add Domain Users to"
 209                                 " Users\n"));
 210                         return status;
 211                 }
 212         }
 213
 214         return NT_STATUS_OK;
 215 }
 216
 217 /*******************************************************************
 218 *******************************************************************/
 219
 220 static NTSTATUS create_builtin_administrators( void )
 221 {
 222         NTSTATUS status;
 223         DOM_SID dom_admins, root_sid;
 224         fstring root_name;
 225         enum lsa_SidType type;
 226         TALLOC_CTX *ctx;
 227         BOOL ret;
 228
 229         status = pdb_create_builtin_alias( BUILTIN_ALIAS_RID_ADMINS );
 230         if ( !NT_STATUS_IS_OK(status) ) {
 231                 DEBUG(0,("create_builtin_administrators: Failed to create Administrators\n"));
 232                 return status;
 233         }
 234
 235         /* add domain admins */
 236         if ((IS_DC || (lp_server_role() == ROLE_DOMAIN_MEMBER))
 237                 && secrets_fetch_domain_sid(lp_workgroup(), &dom_admins))
 238         {
 239                 sid_append_rid(&dom_admins, DOMAIN_GROUP_RID_ADMINS);
 240                 status = pdb_add_aliasmem( &global_sid_Builtin_Administrators, &dom_admins );
 241                 if ( !NT_STATUS_IS_OK(status) ) {
 242                         DEBUG(0,("create_builtin_administrators: Failed to add Domain Admins"
 243                                 " Administrators\n"));
 244                         return status;
 245                 }
 246         }
 247
 248         /* add root */
 249         if ( (ctx = talloc_init("create_builtin_administrators")) == NULL ) {
 250                 return NT_STATUS_NO_MEMORY;
 251         }
 252         fstr_sprintf( root_name, "%s\\root", get_global_sam_name() );
 253         ret = lookup_name( ctx, root_name, 0, NULL, NULL, &root_sid, &type );
 254         TALLOC_FREE( ctx );
 255
 256         if ( ret ) {
 257                 status = pdb_add_aliasmem( &global_sid_Builtin_Administrators, &root_sid );
 258                 if ( !NT_STATUS_IS_OK(status) ) {
 259                         DEBUG(0,("create_builtin_administrators: Failed to add root"
 260                                 " Administrators\n"));
 261                         return status;
 262                 }
 263         }
 264
 265         return NT_STATUS_OK;
 266 }
 267
 268
 269 /*******************************************************************
 270  Create a NT token for the user, expanding local aliases
 271 *******************************************************************/
 272
 273 struct nt_user_token *create_local_nt_token(TALLOC_CTX *mem_ctx,
 274                                             const DOM_SID *user_sid,
 275                                             BOOL is_guest,
 276                                             int num_groupsids,
 277                                             const DOM_SID *groupsids)
 278 {
 279         struct nt_user_token *result = NULL;
 280         int i;
 281         NTSTATUS status;
 282         gid_t gid;
 283
 284         DEBUG(10, ("Create local NT token for %s\n", sid_string_static(user_sid)));
 285
 286         if (!(result = TALLOC_ZERO_P(mem_ctx, NT_USER_TOKEN))) {
 287                 DEBUG(0, ("talloc failed\n"));
 288                 return NULL;
 289         }
 290
 291         /* Add the user and primary group sid */
 292
 293         if (!add_sid_to_array(result, user_sid,
 294                          &result->user_sids, &result->num_sids)) {
 295                 return NULL;
 296         }
 297
 298         /* For guest, num_groupsids may be zero. */
 299         if (num_groupsids) {
 300                 if (!add_sid_to_array(result, &groupsids[0],
 301                                  &result->user_sids, &result->num_sids)) {
 302                         return NULL;
 303                 }
 304         }
 305
 306         /* Add in BUILTIN sids */
 307
 308         if (!add_sid_to_array(result, &global_sid_World,
 309                          &result->user_sids, &result->num_sids)) {
 310                 return NULL;
 311         }
 312         if (!add_sid_to_array(result, &global_sid_Network,
 313                          &result->user_sids, &result->num_sids)) {
 314                 return NULL;
 315         }
 316
 317         if (is_guest) {
 318                 if (!add_sid_to_array(result, &global_sid_Builtin_Guests,
 319                                  &result->user_sids, &result->num_sids)) {
 320                         return NULL;
 321                 }
 322         } else {
 323                 if (!add_sid_to_array(result, &global_sid_Authenticated_Users,
 324                                  &result->user_sids, &result->num_sids)) {
 325                         return NULL;
 326                 }
 327         }
 328
 329         /* Now the SIDs we got from authentication. These are the ones from
 330          * the info3 struct or from the pdb_enum_group_memberships, depending
 331          * on who authenticated the user.
 332          * Note that we start the for loop at "1" here, we already added the
 333          * first group sid as primary above. */
 334
 335         for (i=1; i<num_groupsids; i++) {
 336                 if (!add_sid_to_array_unique(result, &groupsids[i],
 337                                         &result->user_sids, &result->num_sids)) {
 338                         return NULL;
 339                 }
 340         }
 341
 342         /* Deal with the BUILTIN\Administrators group.  If the SID can
 343            be resolved then assume that the add_aliasmem( S-1-5-32 )
 344            handled it. */
 345
 346         if ( !sid_to_gid( &global_sid_Builtin_Administrators, &gid ) ) {
 347                 /* We can only create a mapping if winbind is running
 348                    and the nested group functionality has been enabled */
 349
 350                 if ( lp_winbind_nested_groups() && winbind_ping() ) {
 351                         become_root();
 352                         status = create_builtin_administrators( );
 353                         if ( !NT_STATUS_IS_OK(status) ) {
 354                                 DEBUG(2,("create_local_nt_token: Failed to create BUILTIN\\Administrators group!\n"));
 355                                 /* don't fail, just log the message */
 356                         }
 357                         unbecome_root();
 358                 }
 359                 else {
 360                         status = add_builtin_administrators( result );
 361                         if ( !NT_STATUS_IS_OK(status) ) {
 362                                 /* just log a complaint but do not fail */
 363                                 DEBUG(3,("create_local_nt_token: failed to check for local Administrators"
 364                                         " membership (%s)\n", nt_errstr(status)));
 365                         }
 366                 }
 367         }
 368
 369         /* Deal with the BUILTIN\Users group.  If the SID can
 370            be resolved then assume that the add_aliasmem( S-1-5-32 )
 371            handled it. */
 372
 373         if ( !sid_to_gid( &global_sid_Builtin_Users, &gid ) ) {
 374                 /* We can only create a mapping if winbind is running
 375                    and the nested group functionality has been enabled */
 376
 377                 if ( lp_winbind_nested_groups() && winbind_ping() ) {
 378                         become_root();
 379                         status = create_builtin_users( );
 380                         if ( !NT_STATUS_IS_OK(status) ) {
 381                                 DEBUG(2,("create_local_nt_token: Failed to create BUILTIN\\Users group!\n"));
 382                                 /* don't fail, just log the message */
 383                         }
 384                         unbecome_root();
 385                 }
 386         }
 387
 388         /* Deal with local groups */
 389
 390         if (lp_winbind_nested_groups()) {
 391
 392                 /* Now add the aliases. First the one from our local SAM */
 393
 394                 status = add_aliases(get_global_sam_sid(), result);
 395
 396                 if (!NT_STATUS_IS_OK(status)) {
 397                         TALLOC_FREE(result);
 398                         return NULL;
 399                 }
 400
 401                 /* Finally the builtin ones */
 402
 403                 status = add_aliases(&global_sid_Builtin, result);
 404
 405                 if (!NT_STATUS_IS_OK(status)) {
 406                         TALLOC_FREE(result);
 407                         return NULL;
 408                 }
 409         }
 410
 411
 412         get_privileges_for_sids(&result->privileges, result->user_sids,
 413                                 result->num_sids);
 414         return result;
 415 }
 416
 417 /****************************************************************************
 418  prints a NT_USER_TOKEN to debug output.
 419 ****************************************************************************/
 420
 421 void debug_nt_user_token(int dbg_class, int dbg_lev, NT_USER_TOKEN *token)
 422 {
 423         size_t     i;
 424
 425         if (!token) {
 426                 DEBUGC(dbg_class, dbg_lev, ("NT user token: (NULL)\n"));
 427                 return;
 428         }
 429
 430         DEBUGC(dbg_class, dbg_lev,
 431                ("NT user token of user %s\n",
 432                 sid_string_static(&token->user_sids[0]) ));
 433         DEBUGADDC(dbg_class, dbg_lev,
 434                   ("contains %lu SIDs\n", (unsigned long)token->num_sids));
 435         for (i = 0; i < token->num_sids; i++)
 436                 DEBUGADDC(dbg_class, dbg_lev,
 437                           ("SID[%3lu]: %s\n", (unsigned long)i,
 438                            sid_string_static(&token->user_sids[i])));
 439
 440         dump_se_priv( dbg_class, dbg_lev, &token->privileges );
 441 }
 442
 443 /****************************************************************************
 444  prints a UNIX 'token' to debug output.
 445 ****************************************************************************/
 446
 447 void debug_unix_user_token(int dbg_class, int dbg_lev, uid_t uid, gid_t gid,
 448                            int n_groups, gid_t *groups)
 449 {
 450         int     i;
 451         DEBUGC(dbg_class, dbg_lev,
 452                ("UNIX token of user %ld\n", (long int)uid));
 453
 454         DEBUGADDC(dbg_class, dbg_lev,
 455                   ("Primary group is %ld and contains %i supplementary "
 456                    "groups\n", (long int)gid, n_groups));
 457         for (i = 0; i < n_groups; i++)
 458                 DEBUGADDC(dbg_class, dbg_lev, ("Group[%3i]: %ld\n", i,
 459                         (long int)groups[i]));
 460 }
 461
 462 /* END */