source4/dsdb/samdb/ldb_modules/descriptor.c

   1 /*
   2    ldb database library
   3
   4    Copyright (C) Simo Sorce  2006-2008
   5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005-2007
   6    Copyright (C) Nadezhda Ivanova  2009
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 /*
  23  *  Name: ldb
  24  *
  25  *  Component: DS Security descriptor module
  26  *
  27  *  Description:
  28  *  - Calculate the security descriptor of a newly created object
  29  *  - Perform sd recalculation on a move operation
  30  *  - Handle sd modification invariants
  31  *
  32  *  Author: Nadezhda Ivanova
  33  */
  34
  35 #include "includes.h"
  36 #include "ldb_module.h"
  37 #include "dlinklist.h"
  38 #include "dsdb/samdb/samdb.h"
  39 #include "librpc/ndr/libndr.h"
  40 #include "librpc/gen_ndr/ndr_security.h"
  41 #include "libcli/security/security.h"
  42 #include "auth/auth.h"
  43 #include "param/param.h"
  44
  45 struct descriptor_context {
  46                 struct ldb_module *module;
  47                 struct ldb_request *req;
  48                 struct ldb_reply *search_res;
  49                 int (*step_fn)(struct descriptor_context *);
  50 };
  51
  52 static const struct dsdb_class * get_last_structural_class(const struct dsdb_schema *schema, struct ldb_message_element *element)
  53 {
  54         const struct dsdb_class *last_class = NULL;
  55         int i;
  56         for (i = 0; i < element->num_values; i++){
  57                 if (!last_class)
  58                         last_class = dsdb_class_by_lDAPDisplayName_ldb_val(schema, &element->values[i]);
  59                 else {
  60                         const struct dsdb_class *tmp_class = dsdb_class_by_lDAPDisplayName_ldb_val(schema, &element->values[i]);
  61                         if (tmp_class->subClass_order > last_class->subClass_order)
  62                                 last_class = tmp_class;
  63                 }
  64         }
  65         return last_class;
  66 }
  67
  68 struct dom_sid *get_default_ag(TALLOC_CTX *mem_ctx,
  69                                struct ldb_dn *dn,
  70                                struct security_token *token,
  71                                struct ldb_context *ldb)
  72 {
  73         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
  74         struct ldb_dn *root_base_dn = ldb_get_root_basedn(ldb);
  75         struct ldb_dn *schema_base_dn = ldb_get_schema_basedn(ldb);
  76         struct ldb_dn *config_base_dn = ldb_get_config_basedn(ldb);
  77         const struct dom_sid *domain_sid = samdb_domain_sid(ldb);
  78         struct dom_sid *da_sid = dom_sid_add_rid(tmp_ctx, domain_sid, DOMAIN_RID_ADMINS);
  79         struct dom_sid *ea_sid = dom_sid_add_rid(tmp_ctx, domain_sid, DOMAIN_RID_ENTERPRISE_ADMINS);
  80         struct dom_sid *sa_sid = dom_sid_add_rid(tmp_ctx, domain_sid, DOMAIN_RID_SCHEMA_ADMINS);
  81         struct dom_sid *dag_sid;
  82
  83         if (ldb_dn_compare_base(schema_base_dn, dn) == 0){
  84                 if (security_token_has_sid(token, sa_sid))
  85                         dag_sid = dom_sid_dup(mem_ctx, sa_sid);
  86                 else if (security_token_has_sid(token, ea_sid))
  87                         dag_sid = dom_sid_dup(mem_ctx, ea_sid);
  88                 else if (security_token_has_sid(token, da_sid))
  89                         dag_sid = dom_sid_dup(mem_ctx, da_sid);
  90                 else
  91                         dag_sid = NULL;
  92         }
  93         else if (ldb_dn_compare_base(config_base_dn, dn) == 0){
  94                 if (security_token_has_sid(token, ea_sid))
  95                         dag_sid = dom_sid_dup(mem_ctx, ea_sid);
  96                 else if (security_token_has_sid(token, da_sid))
  97                         dag_sid = dom_sid_dup(mem_ctx, da_sid);
  98                 else
  99                         dag_sid = NULL;
 100         }
 101         else if (ldb_dn_compare_base(root_base_dn, dn) == 0){
 102                 if (security_token_has_sid(token, da_sid))
 103                         dag_sid = dom_sid_dup(mem_ctx, da_sid);
 104                 else if (security_token_has_sid(token, ea_sid))
 105                                 dag_sid = dom_sid_dup(mem_ctx, ea_sid);
 106                 else
 107                         dag_sid = NULL;
 108         }
 109         else
 110                 dag_sid = NULL;
 111
 112         talloc_free(tmp_ctx);
 113         return dag_sid;
 114 }
 115
 116 static struct security_descriptor *get_sd_unpacked(struct ldb_module *module, TALLOC_CTX *mem_ctx,
 117                                             const struct dsdb_class *objectclass)
 118 {
 119         struct ldb_context *ldb = ldb_module_get_ctx(module);
 120         struct security_descriptor *sd;
 121         const struct dom_sid *domain_sid = samdb_domain_sid(ldb);
 122
 123         if (!objectclass->defaultSecurityDescriptor || !domain_sid) {
 124                 return NULL;
 125         }
 126
 127         sd = sddl_decode(mem_ctx,
 128                          objectclass->defaultSecurityDescriptor,
 129                          domain_sid);
 130         return sd;
 131 }
 132
 133 static struct dom_sid *get_default_group(TALLOC_CTX *mem_ctx,
 134                                          struct ldb_context *ldb,
 135                                          struct dom_sid *dag)
 136 {
 137         int *domainFunctionality;
 138
 139         domainFunctionality = talloc_get_type(
 140                 ldb_get_opaque(ldb, "domainFunctionality"), int);
 141
 142         if (*domainFunctionality
 143                         && (*domainFunctionality >= DS_DOMAIN_FUNCTION_2008)) {
 144                 return dag;
 145         }
 146
 147         return NULL;
 148 }
 149
 150 static DATA_BLOB *get_new_descriptor(struct ldb_module *module,
 151                                      struct ldb_dn *dn,
 152                                      TALLOC_CTX *mem_ctx,
 153                                      const struct dsdb_class *objectclass,
 154                                      const struct ldb_val *parent,
 155                                      struct ldb_val *object)
 156 {
 157         struct security_descriptor *user_descriptor = NULL, *parent_descriptor = NULL;
 158         struct security_descriptor *new_sd;
 159         DATA_BLOB *linear_sd;
 160         enum ndr_err_code ndr_err;
 161         struct ldb_context *ldb = ldb_module_get_ctx(module);
 162         struct auth_session_info *session_info
 163                 = ldb_get_opaque(ldb, "sessionInfo");
 164         const struct dom_sid *domain_sid = samdb_domain_sid(ldb);
 165         char *sddl_sd;
 166         struct dom_sid *default_owner;
 167         struct dom_sid *default_group;
 168
 169         if (object){
 170                 user_descriptor = talloc(mem_ctx, struct security_descriptor);
 171                 if(!user_descriptor)
 172                         return NULL;
 173                 ndr_err = ndr_pull_struct_blob(object, user_descriptor, NULL,
 174                                                user_descriptor,
 175                                                (ndr_pull_flags_fn_t)ndr_pull_security_descriptor);
 176
 177                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)){
 178                         talloc_free(user_descriptor);
 179                         return NULL;
 180                 }
 181         }
 182         else
 183                 user_descriptor = get_sd_unpacked(module, mem_ctx, objectclass);
 184
 185         if (parent){
 186                 parent_descriptor = talloc(mem_ctx, struct security_descriptor);
 187                 if(!parent_descriptor)
 188                         return NULL;
 189                 ndr_err = ndr_pull_struct_blob(parent, parent_descriptor, NULL,
 190                                                parent_descriptor,
 191                                                (ndr_pull_flags_fn_t)ndr_pull_security_descriptor);
 192
 193                 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)){
 194                         talloc_free(parent_descriptor);
 195                         return NULL;
 196                 }
 197         }
 198         default_owner = get_default_ag(mem_ctx, dn,
 199                                        session_info->security_token, ldb);
 200         default_group = get_default_group(mem_ctx, ldb, default_owner);
 201         new_sd = create_security_descriptor(mem_ctx, parent_descriptor, user_descriptor, true,
 202                                             NULL, SEC_DACL_AUTO_INHERIT|SEC_SACL_AUTO_INHERIT,
 203                                             session_info->security_token,
 204                                             default_owner, default_group,
 205                                             map_generic_rights_ds);
 206         if (!new_sd)
 207                 return NULL;
 208
 209
 210         sddl_sd = sddl_encode(mem_ctx, new_sd, domain_sid);
 211         DEBUG(10, ("Object %s created with desriptor %s", ldb_dn_get_linearized(dn), sddl_sd));
 212
 213         linear_sd = talloc(mem_ctx, DATA_BLOB);
 214         if (!linear_sd) {
 215                 return NULL;
 216         }
 217
 218         ndr_err = ndr_push_struct_blob(linear_sd, mem_ctx,
 219                                        lp_iconv_convenience(ldb_get_opaque(ldb, "loadparm")),
 220                                        new_sd,
 221                                        (ndr_push_flags_fn_t)ndr_push_security_descriptor);
 222         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 223                 return NULL;
 224         }
 225
 226         return linear_sd;
 227 }
 228
 229 static struct descriptor_context *descriptor_init_context(struct ldb_module *module,
 230                                                           struct ldb_request *req)
 231 {
 232         struct ldb_context *ldb;
 233         struct descriptor_context *ac;
 234
 235         ldb = ldb_module_get_ctx(module);
 236
 237         ac = talloc_zero(req, struct descriptor_context);
 238         if (ac == NULL) {
 239                 ldb_set_errstring(ldb, "Out of Memory");
 240                 return NULL;
 241         }
 242
 243         ac->module = module;
 244         ac->req = req;
 245         return ac;
 246 }
 247
 248 static int get_search_callback(struct ldb_request *req, struct ldb_reply *ares)
 249 {
 250         struct ldb_context *ldb;
 251         struct descriptor_context *ac;
 252         int ret;
 253
 254         ac = talloc_get_type(req->context, struct descriptor_context);
 255         ldb = ldb_module_get_ctx(ac->module);
 256
 257         if (!ares) {
 258                 return ldb_module_done(ac->req, NULL, NULL,
 259                                         LDB_ERR_OPERATIONS_ERROR);
 260         }
 261         if (ares->error != LDB_SUCCESS &&
 262             ares->error != LDB_ERR_NO_SUCH_OBJECT) {
 263                 return ldb_module_done(ac->req, ares->controls,
 264                                         ares->response, ares->error);
 265         }
 266
 267         switch (ares->type) {
 268         case LDB_REPLY_ENTRY:
 269                 if (ac->search_res != NULL) {
 270                         ldb_set_errstring(ldb, "Too many results");
 271                         talloc_free(ares);
 272                         return ldb_module_done(ac->req, NULL, NULL,
 273                                                 LDB_ERR_OPERATIONS_ERROR);
 274                 }
 275
 276                 ac->search_res = talloc_steal(ac, ares);
 277                 break;
 278
 279         case LDB_REPLY_REFERRAL:
 280                 /* ignore */
 281                 talloc_free(ares);
 282                 break;
 283
 284         case LDB_REPLY_DONE:
 285                 talloc_free(ares);
 286                 ret = ac->step_fn(ac);
 287                 if (ret != LDB_SUCCESS) {
 288                         return ldb_module_done(ac->req, NULL, NULL, ret);
 289                 }
 290                 break;
 291         }
 292
 293         return LDB_SUCCESS;
 294 }
 295 static int descriptor_op_callback(struct ldb_request *req, struct ldb_reply *ares)
 296 {
 297         struct descriptor_context *ac;
 298
 299         ac = talloc_get_type(req->context, struct descriptor_context);
 300
 301         if (!ares) {
 302                 return ldb_module_done(ac->req, NULL, NULL,
 303                                         LDB_ERR_OPERATIONS_ERROR);
 304         }
 305         if (ares->error != LDB_SUCCESS) {
 306                 return ldb_module_done(ac->req, ares->controls,
 307                                         ares->response, ares->error);
 308         }
 309
 310         if (ares->type != LDB_REPLY_DONE) {
 311                 talloc_free(ares);
 312                 return ldb_module_done(ac->req, NULL, NULL,
 313                                         LDB_ERR_OPERATIONS_ERROR);
 314         }
 315
 316         return ldb_module_done(ac->req, ares->controls,
 317                                 ares->response, ares->error);
 318 }
 319
 320 static int descriptor_do_add(struct descriptor_context *ac)
 321 {
 322         struct ldb_context *ldb;
 323         const struct dsdb_schema *schema;
 324         struct ldb_request *add_req;
 325         struct ldb_message_element *objectclass_element, *sd_element = NULL;
 326         struct ldb_message *msg;
 327         TALLOC_CTX *mem_ctx;
 328         int ret;
 329         struct ldb_val *sd_val = NULL;
 330         const struct ldb_val *parentsd_val = NULL;
 331         DATA_BLOB *sd;
 332         const struct dsdb_class *objectclass;
 333
 334         ldb = ldb_module_get_ctx(ac->module);
 335         schema = dsdb_get_schema(ldb);
 336
 337         mem_ctx = talloc_new(ac);
 338         if (mem_ctx == NULL) {
 339                 return LDB_ERR_OPERATIONS_ERROR;
 340         }
 341
 342         msg = ldb_msg_copy_shallow(ac, ac->req->op.add.message);
 343
 344         /* get the security descriptor values*/
 345         sd_element = ldb_msg_find_element(msg, "nTSecurityDescriptor");
 346         objectclass_element = ldb_msg_find_element(msg, "objectClass");
 347         objectclass = get_last_structural_class(schema, objectclass_element);
 348
 349         if (!objectclass)
 350                 return LDB_ERR_OPERATIONS_ERROR;
 351
 352         if (sd_element)
 353                 sd_val = &sd_element->values[0];
 354         /* NC's have no parent */
 355         if ((ldb_dn_compare(msg->dn, (ldb_get_schema_basedn(ldb))) == 0) ||
 356                         (ldb_dn_compare(msg->dn, (ldb_get_config_basedn(ldb))) == 0) ||
 357                         (ldb_dn_compare(msg->dn, (ldb_get_root_basedn(ldb))) == 0))
 358                 parentsd_val = NULL;
 359         else if (ac->search_res != NULL)
 360                 parentsd_val = ldb_msg_find_ldb_val(ac->search_res->message, "nTSecurityDescriptor");
 361
 362
 363         /* get the parent descriptor and the one provided. If not provided, get the default.*/
 364         /* convert to security descriptor and calculate */
 365         sd = get_new_descriptor(ac->module, msg->dn, mem_ctx, objectclass,
 366                         parentsd_val, sd_val);
 367         if (sd) {
 368                 ldb_msg_add_steal_value(msg, "nTSecurityDescriptor", sd);
 369         }
 370
 371         talloc_free(mem_ctx);
 372         ret = ldb_msg_sanity_check(ldb, msg);
 373
 374         if (ret != LDB_SUCCESS) {
 375                 return ret;
 376         }
 377
 378         ret = ldb_build_add_req(&add_req, ldb, ac,
 379                                 msg,
 380                                 ac->req->controls,
 381                                 ac, descriptor_op_callback,
 382                                 ac->req);
 383         if (ret != LDB_SUCCESS) {
 384                 return ret;
 385         }
 386
 387         /* perform the add */
 388         return ldb_next_request(ac->module, add_req);
 389 }
 390
 391 static int descriptor_add(struct ldb_module *module, struct ldb_request *req)
 392 {
 393         struct ldb_context *ldb;
 394         struct ldb_request *search_req;
 395         struct descriptor_context *ac;
 396         struct ldb_dn *parent_dn;
 397         int ret;
 398         static const char * const descr_attrs[] = { "nTSecurityDescriptor", NULL };
 399
 400         ldb = ldb_module_get_ctx(module);
 401
 402         ldb_debug(ldb, LDB_DEBUG_TRACE, "descriptor_add\n");
 403
 404         if (ldb_dn_is_special(req->op.add.message->dn)) {
 405                 return ldb_next_request(module, req);
 406         }
 407
 408         ac = descriptor_init_context(module, req);
 409         if (ac == NULL) {
 410                 return LDB_ERR_OPERATIONS_ERROR;
 411         }
 412
 413         /* If there isn't a parent, just go on to the add processing */
 414         if (ldb_dn_get_comp_num(ac->req->op.add.message->dn) == 1) {
 415                 return descriptor_do_add(ac);
 416         }
 417
 418         /* get copy of parent DN */
 419         parent_dn = ldb_dn_get_parent(ac, ac->req->op.add.message->dn);
 420         if (parent_dn == NULL) {
 421                 ldb_oom(ldb);
 422                 return LDB_ERR_OPERATIONS_ERROR;
 423         }
 424
 425         ret = ldb_build_search_req(&search_req, ldb,
 426                                    ac, parent_dn, LDB_SCOPE_BASE,
 427                                    "(objectClass=*)", descr_attrs,
 428                                    NULL,
 429                                    ac, get_search_callback,
 430                                    req);
 431         if (ret != LDB_SUCCESS) {
 432                 return ret;
 433         }
 434         talloc_steal(search_req, parent_dn);
 435
 436         ac->step_fn = descriptor_do_add;
 437
 438         return ldb_next_request(ac->module, search_req);
 439 }
 440 /* TODO */
 441 static int descriptor_modify(struct ldb_module *module, struct ldb_request *req)
 442 {
 443         struct ldb_context *ldb = ldb_module_get_ctx(module);
 444         ldb_debug(ldb, LDB_DEBUG_TRACE, "descriptor_modify\n");
 445         return ldb_next_request(module, req);
 446 }
 447 /* TODO */
 448 static int descriptor_rename(struct ldb_module *module, struct ldb_request *req)
 449 {
 450         struct ldb_context *ldb = ldb_module_get_ctx(module);
 451         ldb_debug(ldb, LDB_DEBUG_TRACE, "descriptor_rename\n");
 452         return ldb_next_request(module, req);
 453 }
 454
 455 _PUBLIC_ const struct ldb_module_ops ldb_descriptor_module_ops = {
 456         .name              = "descriptor",
 457         .add           = descriptor_add,
 458         .modify        = descriptor_modify,
 459         .rename        = descriptor_rename,
 460 };
 461
 462