source4/dsdb/samdb/ldb_modules/acl.c

   1 /*
   2   ldb database library
   3
   4   Copyright (C) Simo Sorce 2006-2008
   5   Copyright (C) Nadezhda Ivanova 2009
   6   Copyright (C) Anatoliy Atanasov  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: ldb ACL module
  26  *
  27  *  Description: Module that performs authorisation access checks based on the
  28  *               account's security context and the DACL of the object being polled.
  29  *               Only DACL checks implemented at this point
  30  *
  31  *  Authors: Nadezhda Ivanova, Anatoliy Atanasov
  32  */
  33
  34 #include "includes.h"
  35 #include "ldb_module.h"
  36 #include "auth/auth.h"
  37 #include "libcli/security/security.h"
  38 #include "dsdb/samdb/samdb.h"
  39 #include "librpc/gen_ndr/ndr_security.h"
  40 #include "param/param.h"
  41 #include "dsdb/samdb/ldb_modules/util.h"
  42 #include "lib/util/tsort.h"
  43 #include "system/kerberos.h"
  44 #include "auth/kerberos/kerberos.h"
  45
  46 struct extended_access_check_attribute {
  47         const char *oa_name;
  48         const uint32_t requires_rights;
  49 };
  50
  51 struct acl_private {
  52         bool acl_search;
  53         const char **password_attrs;
  54         void *cached_schema_ptr;
  55         uint64_t cached_schema_metadata_usn;
  56         uint64_t cached_schema_loaded_usn;
  57         const char **confidential_attrs;
  58 };
  59
  60 struct acl_context {
  61         struct ldb_module *module;
  62         struct ldb_request *req;
  63         bool am_system;
  64         bool am_administrator;
  65         bool modify_search;
  66         bool constructed_attrs;
  67         bool allowedAttributes;
  68         bool allowedAttributesEffective;
  69         bool allowedChildClasses;
  70         bool allowedChildClassesEffective;
  71         bool sDRightsEffective;
  72         bool userPassword;
  73         const char * const *attrs;
  74         struct dsdb_schema *schema;
  75 };
  76
  77 static int acl_module_init(struct ldb_module *module)
  78 {
  79         struct ldb_context *ldb;
  80         struct acl_private *data;
  81         int ret;
  82         unsigned int i, n, j;
  83         TALLOC_CTX *mem_ctx;
  84         static const char * const attrs[] = { "passwordAttribute", NULL };
  85         static const char * const secret_attrs[] = {
  86                 DSDB_SECRET_ATTRIBUTES
  87         };
  88         struct ldb_result *res;
  89         struct ldb_message *msg;
  90         struct ldb_message_element *password_attributes;
  91
  92         ldb = ldb_module_get_ctx(module);
  93
  94         ret = ldb_mod_register_control(module, LDB_CONTROL_SD_FLAGS_OID);
  95         if (ret != LDB_SUCCESS) {
  96                 ldb_debug(ldb, LDB_DEBUG_ERROR,
  97                           "acl_module_init: Unable to register control with rootdse!\n");
  98                 return ldb_operr(ldb);
  99         }
 100
 101         data = talloc_zero(module, struct acl_private);
 102         if (data == NULL) {
 103                 return ldb_oom(ldb);
 104         }
 105
 106         data->acl_search = lpcfg_parm_bool(ldb_get_opaque(ldb, "loadparm"),
 107                                         NULL, "acl", "search", true);
 108         ldb_module_set_private(module, data);
 109
 110         mem_ctx = talloc_new(module);
 111         if (!mem_ctx) {
 112                 return ldb_oom(ldb);
 113         }
 114
 115         ret = dsdb_module_search_dn(module, mem_ctx, &res,
 116                                     ldb_dn_new(mem_ctx, ldb, "@KLUDGEACL"),
 117                                     attrs,
 118                                     DSDB_FLAG_NEXT_MODULE |
 119                                     DSDB_FLAG_AS_SYSTEM,
 120                                     NULL);
 121         if (ret != LDB_SUCCESS) {
 122                 goto done;
 123         }
 124         if (res->count == 0) {
 125                 goto done;
 126         }
 127
 128         if (res->count > 1) {
 129                 talloc_free(mem_ctx);
 130                 return LDB_ERR_CONSTRAINT_VIOLATION;
 131         }
 132
 133         msg = res->msgs[0];
 134
 135         password_attributes = ldb_msg_find_element(msg, "passwordAttribute");
 136         if (!password_attributes) {
 137                 goto done;
 138         }
 139         data->password_attrs = talloc_array(data, const char *,
 140                         password_attributes->num_values +
 141                         ARRAY_SIZE(secret_attrs) + 1);
 142         if (!data->password_attrs) {
 143                 talloc_free(mem_ctx);
 144                 return ldb_oom(ldb);
 145         }
 146
 147         n = 0;
 148         for (i=0; i < password_attributes->num_values; i++) {
 149                 data->password_attrs[n] = (const char *)password_attributes->values[i].data;
 150                 talloc_steal(data->password_attrs, password_attributes->values[i].data);
 151                 n++;
 152         }
 153
 154         for (i=0; i < ARRAY_SIZE(secret_attrs); i++) {
 155                 bool found = false;
 156
 157                 for (j=0; j < n; j++) {
 158                         if (strcasecmp(data->password_attrs[j], secret_attrs[i]) == 0) {
 159                                 found = true;
 160                                 break;
 161                         }
 162                 }
 163
 164                 if (found) {
 165                         continue;
 166                 }
 167
 168                 data->password_attrs[n] = talloc_strdup(data->password_attrs,
 169                                                         secret_attrs[i]);
 170                 if (data->password_attrs[n] == NULL) {
 171                         talloc_free(mem_ctx);
 172                         return ldb_oom(ldb);
 173                 }
 174                 n++;
 175         }
 176         data->password_attrs[n] = NULL;
 177
 178 done:
 179         talloc_free(mem_ctx);
 180         return ldb_next_init(module);
 181 }
 182
 183 static int acl_allowedAttributes(struct ldb_module *module,
 184                                  const struct dsdb_schema *schema,
 185                                  struct ldb_message *sd_msg,
 186                                  struct ldb_message *msg,
 187                                  struct acl_context *ac)
 188 {
 189         struct ldb_message_element *oc_el;
 190         struct ldb_context *ldb = ldb_module_get_ctx(module);
 191         TALLOC_CTX *mem_ctx;
 192         const char **attr_list;
 193         int i, ret;
 194
 195         /* If we don't have a schema yet, we can't do anything... */
 196         if (schema == NULL) {
 197                 ldb_asprintf_errstring(ldb, "cannot add allowedAttributes to %s because no schema is loaded", ldb_dn_get_linearized(msg->dn));
 198                 return LDB_ERR_OPERATIONS_ERROR;
 199         }
 200
 201         /* Must remove any existing attribute */
 202         if (ac->allowedAttributes) {
 203                 ldb_msg_remove_attr(msg, "allowedAttributes");
 204         }
 205
 206         mem_ctx = talloc_new(msg);
 207         if (!mem_ctx) {
 208                 return ldb_oom(ldb);
 209         }
 210
 211         oc_el = ldb_msg_find_element(sd_msg, "objectClass");
 212         attr_list = dsdb_full_attribute_list(mem_ctx, schema, oc_el, DSDB_SCHEMA_ALL);
 213         if (!attr_list) {
 214                 ldb_asprintf_errstring(ldb, "acl: Failed to get list of attributes");
 215                 talloc_free(mem_ctx);
 216                 return LDB_ERR_OPERATIONS_ERROR;
 217         }
 218         if (ac->allowedAttributes) {
 219                 for (i=0; attr_list && attr_list[i]; i++) {
 220                         ldb_msg_add_string(msg, "allowedAttributes", attr_list[i]);
 221                 }
 222         }
 223         if (ac->allowedAttributesEffective) {
 224                 struct security_descriptor *sd;
 225                 struct dom_sid *sid = NULL;
 226                 struct ldb_control *as_system = ldb_request_get_control(ac->req,
 227                                                                         LDB_CONTROL_AS_SYSTEM_OID);
 228
 229                 if (as_system != NULL) {
 230                         as_system->critical = 0;
 231                 }
 232
 233                 ldb_msg_remove_attr(msg, "allowedAttributesEffective");
 234                 if (ac->am_system || as_system) {
 235                         for (i=0; attr_list && attr_list[i]; i++) {
 236                                 ldb_msg_add_string(msg, "allowedAttributesEffective", attr_list[i]);
 237                         }
 238                         return LDB_SUCCESS;
 239                 }
 240
 241                 ret = dsdb_get_sd_from_ldb_message(ldb_module_get_ctx(module), mem_ctx, sd_msg, &sd);
 242
 243                 if (ret != LDB_SUCCESS) {
 244                         return ret;
 245                 }
 246
 247                 sid = samdb_result_dom_sid(mem_ctx, sd_msg, "objectSid");
 248                 for (i=0; attr_list && attr_list[i]; i++) {
 249                         const struct dsdb_attribute *attr = dsdb_attribute_by_lDAPDisplayName(schema,
 250                                                                                         attr_list[i]);
 251                         if (!attr) {
 252                                 return ldb_operr(ldb);
 253                         }
 254                         /* remove constructed attributes */
 255                         if (attr->systemFlags & DS_FLAG_ATTR_IS_CONSTRUCTED
 256                             || attr->systemOnly
 257                             || (attr->linkID != 0 && attr->linkID % 2 != 0 )) {
 258                                 continue;
 259                         }
 260                         ret = acl_check_access_on_attribute(module,
 261                                                             msg,
 262                                                             sd,
 263                                                             sid,
 264                                                             SEC_ADS_WRITE_PROP,
 265                                                             attr);
 266                         if (ret == LDB_SUCCESS) {
 267                                 ldb_msg_add_string(msg, "allowedAttributesEffective", attr_list[i]);
 268                         }
 269                 }
 270         }
 271         return LDB_SUCCESS;
 272 }
 273
 274 static int acl_childClasses(struct ldb_module *module,
 275                             const struct dsdb_schema *schema,
 276                             struct ldb_message *sd_msg,
 277                             struct ldb_message *msg,
 278                             const char *attrName)
 279 {
 280         struct ldb_message_element *oc_el;
 281         struct ldb_message_element *allowedClasses;
 282         const struct dsdb_class *sclass;
 283         unsigned int i, j;
 284         int ret;
 285
 286         /* If we don't have a schema yet, we can't do anything... */
 287         if (schema == NULL) {
 288                 ldb_asprintf_errstring(ldb_module_get_ctx(module), "cannot add childClassesEffective to %s because no schema is loaded", ldb_dn_get_linearized(msg->dn));
 289                 return LDB_ERR_OPERATIONS_ERROR;
 290         }
 291
 292         /* Must remove any existing attribute, or else confusion reins */
 293         ldb_msg_remove_attr(msg, attrName);
 294         ret = ldb_msg_add_empty(msg, attrName, 0, &allowedClasses);
 295         if (ret != LDB_SUCCESS) {
 296                 return ret;
 297         }
 298
 299         oc_el = ldb_msg_find_element(sd_msg, "objectClass");
 300
 301         for (i=0; oc_el && i < oc_el->num_values; i++) {
 302                 sclass = dsdb_class_by_lDAPDisplayName_ldb_val(schema, &oc_el->values[i]);
 303                 if (!sclass) {
 304                         /* We don't know this class?  what is going on? */
 305                         continue;
 306                 }
 307
 308                 for (j=0; sclass->possibleInferiors && sclass->possibleInferiors[j]; j++) {
 309                         ldb_msg_add_string(msg, attrName, sclass->possibleInferiors[j]);
 310                 }
 311         }
 312         if (allowedClasses->num_values > 1) {
 313                 TYPESAFE_QSORT(allowedClasses->values, allowedClasses->num_values, data_blob_cmp);
 314                 for (i=1 ; i < allowedClasses->num_values; i++) {
 315                         struct ldb_val *val1 = &allowedClasses->values[i-1];
 316                         struct ldb_val *val2 = &allowedClasses->values[i];
 317                         if (data_blob_cmp(val1, val2) == 0) {
 318                                 memmove(val1, val2, (allowedClasses->num_values - i) * sizeof(struct ldb_val));
 319                                 allowedClasses->num_values--;
 320                                 i--;
 321                         }
 322                 }
 323         }
 324
 325         return LDB_SUCCESS;
 326 }
 327
 328 static int acl_check_access_on_class(struct ldb_module *module,
 329                                      const struct dsdb_schema *schema,
 330                                      TALLOC_CTX *mem_ctx,
 331                                      struct security_descriptor *sd,
 332                                      struct security_token *token,
 333                                      struct dom_sid *rp_sid,
 334                                      uint32_t access_mask,
 335                                      const char *class_name)
 336 {
 337         int ret;
 338         NTSTATUS status;
 339         uint32_t access_granted;
 340         struct object_tree *root = NULL;
 341         struct object_tree *new_node = NULL;
 342         const struct GUID *guid;
 343
 344         if (class_name != NULL) {
 345                 guid = class_schemaid_guid_by_lDAPDisplayName(schema, class_name);
 346                 if (!guid) {
 347                         DEBUG(10, ("acl_search: cannot find class %s\n",
 348                                    class_name));
 349                         goto fail;
 350                 }
 351                 if (!insert_in_object_tree(mem_ctx,
 352                                            guid, access_mask,
 353                                            &root, &new_node)) {
 354                         DEBUG(10, ("acl_search: cannot add to object tree guid\n"));
 355                         goto fail;
 356                 }
 357         }
 358
 359         status = sec_access_check_ds(sd, token,
 360                                      access_mask,
 361                                      &access_granted,
 362                                      root,
 363                                      rp_sid);
 364         if (!NT_STATUS_IS_OK(status)) {
 365                 ret = LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
 366         } else {
 367                 ret = LDB_SUCCESS;
 368         }
 369         return ret;
 370 fail:
 371         return ldb_operr(ldb_module_get_ctx(module));
 372 }
 373
 374 static int acl_childClassesEffective(struct ldb_module *module,
 375                                      const struct dsdb_schema *schema,
 376                                      struct ldb_message *sd_msg,
 377                                      struct ldb_message *msg,
 378                                      struct acl_context *ac)
 379 {
 380         struct ldb_message_element *oc_el;
 381         struct ldb_message_element *allowedClasses = NULL;
 382         const struct dsdb_class *sclass;
 383         struct security_descriptor *sd;
 384         struct ldb_control *as_system = ldb_request_get_control(ac->req,
 385                                                                 LDB_CONTROL_AS_SYSTEM_OID);
 386         struct dom_sid *sid = NULL;
 387         unsigned int i, j;
 388         int ret;
 389
 390         if (as_system != NULL) {
 391                 as_system->critical = 0;
 392         }
 393
 394         if (ac->am_system || as_system) {
 395                 return acl_childClasses(module, schema, sd_msg, msg, "allowedChildClassesEffective");
 396         }
 397
 398         /* If we don't have a schema yet, we can't do anything... */
 399         if (schema == NULL) {
 400                 ldb_asprintf_errstring(ldb_module_get_ctx(module), "cannot add allowedChildClassesEffective to %s because no schema is loaded", ldb_dn_get_linearized(msg->dn));
 401                 return LDB_ERR_OPERATIONS_ERROR;
 402         }
 403
 404         /* Must remove any existing attribute, or else confusion reins */
 405         ldb_msg_remove_attr(msg, "allowedChildClassesEffective");
 406
 407         oc_el = ldb_msg_find_element(sd_msg, "objectClass");
 408         ret = dsdb_get_sd_from_ldb_message(ldb_module_get_ctx(module), msg, sd_msg, &sd);
 409         if (ret != LDB_SUCCESS) {
 410                 return ret;
 411         }
 412
 413         sid = samdb_result_dom_sid(msg, sd_msg, "objectSid");
 414         for (i=0; oc_el && i < oc_el->num_values; i++) {
 415                 sclass = dsdb_class_by_lDAPDisplayName_ldb_val(schema, &oc_el->values[i]);
 416                 if (!sclass) {
 417                         /* We don't know this class?  what is going on? */
 418                         continue;
 419                 }
 420
 421                 for (j=0; sclass->possibleInferiors && sclass->possibleInferiors[j]; j++) {
 422                         ret = acl_check_access_on_class(module,
 423                                                         schema,
 424                                                         msg,
 425                                                         sd,
 426                                                         acl_user_token(module),
 427                                                         sid,
 428                                                         SEC_ADS_CREATE_CHILD,
 429                                                         sclass->possibleInferiors[j]);
 430                         if (ret == LDB_SUCCESS) {
 431                                 ldb_msg_add_string(msg, "allowedChildClassesEffective",
 432                                                    sclass->possibleInferiors[j]);
 433                         }
 434                 }
 435         }
 436         allowedClasses = ldb_msg_find_element(msg, "allowedChildClassesEffective");
 437         if (!allowedClasses) {
 438                 return LDB_SUCCESS;
 439         }
 440
 441         if (allowedClasses->num_values > 1) {
 442                 TYPESAFE_QSORT(allowedClasses->values, allowedClasses->num_values, data_blob_cmp);
 443                 for (i=1 ; i < allowedClasses->num_values; i++) {
 444                         struct ldb_val *val1 = &allowedClasses->values[i-1];
 445                         struct ldb_val *val2 = &allowedClasses->values[i];
 446                         if (data_blob_cmp(val1, val2) == 0) {
 447                                 memmove(val1, val2, (allowedClasses->num_values - i) * sizeof( struct ldb_val));
 448                                 allowedClasses->num_values--;
 449                                 i--;
 450                         }
 451                 }
 452         }
 453         return LDB_SUCCESS;
 454 }
 455
 456 static int acl_sDRightsEffective(struct ldb_module *module,
 457                                  struct ldb_message *sd_msg,
 458                                  struct ldb_message *msg,
 459                                  struct acl_context *ac)
 460 {
 461         struct ldb_message_element *rightsEffective;
 462         int ret;
 463         struct security_descriptor *sd;
 464         struct ldb_control *as_system = ldb_request_get_control(ac->req,
 465                                                                 LDB_CONTROL_AS_SYSTEM_OID);
 466         struct dom_sid *sid = NULL;
 467         uint32_t flags = 0;
 468
 469         if (as_system != NULL) {
 470                 as_system->critical = 0;
 471         }
 472
 473         /* Must remove any existing attribute, or else confusion reins */
 474         ldb_msg_remove_attr(msg, "sDRightsEffective");
 475         ret = ldb_msg_add_empty(msg, "sDRightsEffective", 0, &rightsEffective);
 476         if (ret != LDB_SUCCESS) {
 477                 return ret;
 478         }
 479         if (ac->am_system || as_system) {
 480                 flags = SECINFO_OWNER | SECINFO_GROUP |  SECINFO_SACL |  SECINFO_DACL;
 481         }
 482         else {
 483                 /* Get the security descriptor from the message */
 484                 ret = dsdb_get_sd_from_ldb_message(ldb_module_get_ctx(module), msg, sd_msg, &sd);
 485                 if (ret != LDB_SUCCESS) {
 486                         return ret;
 487                 }
 488                 sid = samdb_result_dom_sid(msg, sd_msg, "objectSid");
 489                 ret = acl_check_access_on_attribute(module,
 490                                                     msg,
 491                                                     sd,
 492                                                     sid,
 493                                                     SEC_STD_WRITE_OWNER,
 494                                                     NULL);
 495                 if (ret == LDB_SUCCESS) {
 496                         flags |= SECINFO_OWNER | SECINFO_GROUP;
 497                 }
 498                 ret = acl_check_access_on_attribute(module,
 499                                                     msg,
 500                                                     sd,
 501                                                     sid,
 502                                                     SEC_STD_WRITE_DAC,
 503                                                     NULL);
 504                 if (ret == LDB_SUCCESS) {
 505                         flags |= SECINFO_DACL;
 506                 }
 507                 ret = acl_check_access_on_attribute(module,
 508                                                     msg,
 509                                                     sd,
 510                                                     sid,
 511                                                     SEC_FLAG_SYSTEM_SECURITY,
 512                                                     NULL);
 513                 if (ret == LDB_SUCCESS) {
 514                         flags |= SECINFO_SACL;
 515                 }
 516         }
 517         return samdb_msg_add_uint(ldb_module_get_ctx(module), msg, msg,
 518                                   "sDRightsEffective", flags);
 519 }
 520
 521 static int acl_validate_spn_value(TALLOC_CTX *mem_ctx,
 522                                   struct ldb_context *ldb,
 523                                   const char *spn_value,
 524                                   uint32_t userAccountControl,
 525                                   const char *samAccountName,
 526                                   const char *dnsHostName,
 527                                   const char *netbios_name,
 528                                   const char *ntds_guid)
 529 {
 530         int ret;
 531         krb5_context krb_ctx;
 532         krb5_error_code kerr;
 533         krb5_principal principal;
 534         char *instanceName;
 535         char *serviceType;
 536         char *serviceName;
 537         const char *forest_name = samdb_forest_name(ldb, mem_ctx);
 538         const char *base_domain = samdb_default_domain_name(ldb, mem_ctx);
 539         struct loadparm_context *lp_ctx = talloc_get_type(ldb_get_opaque(ldb, "loadparm"),
 540                                                           struct loadparm_context);
 541         bool is_dc = (userAccountControl & UF_SERVER_TRUST_ACCOUNT) ||
 542                 (userAccountControl & UF_PARTIAL_SECRETS_ACCOUNT);
 543
 544         if (strcasecmp_m(spn_value, samAccountName) == 0) {
 545                 /* MacOS X sets this value, and setting an SPN of your
 546                  * own samAccountName is both pointless and safe */
 547                 return LDB_SUCCESS;
 548         }
 549
 550         kerr = smb_krb5_init_context_basic(mem_ctx,
 551                                            lp_ctx,
 552                                            &krb_ctx);
 553         if (kerr != 0) {
 554                 return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
 555                                  "Could not initialize kerberos context.");
 556         }
 557
 558         ret = krb5_parse_name(krb_ctx, spn_value, &principal);
 559         if (ret) {
 560                 krb5_free_context(krb_ctx);
 561                 return LDB_ERR_CONSTRAINT_VIOLATION;
 562         }
 563
 564         if (principal->name.name_string.len < 2) {
 565                 goto fail;
 566         }
 567
 568         instanceName = principal->name.name_string.val[1];
 569         serviceType = principal->name.name_string.val[0];
 570         if (principal->name.name_string.len == 3) {
 571                 serviceName = principal->name.name_string.val[2];
 572         } else {
 573                 serviceName = NULL;
 574         }
 575
 576         if (serviceName) {
 577                 if (!is_dc) {
 578                         goto fail;
 579                 }
 580                 if (strcasecmp(serviceType, "ldap") == 0) {
 581                         if (strcasecmp(serviceName, netbios_name) != 0 &&
 582                             strcasecmp(serviceName, forest_name) != 0) {
 583                                 goto fail;
 584                         }
 585
 586                 } else if (strcasecmp(serviceType, "gc") == 0) {
 587                         if (strcasecmp(serviceName, forest_name) != 0) {
 588                                 goto fail;
 589                         }
 590                 } else {
 591                         if (strcasecmp(serviceName, base_domain) != 0 &&
 592                             strcasecmp(serviceName, netbios_name) != 0) {
 593                                 goto fail;
 594                         }
 595                 }
 596         }
 597         /* instanceName can be samAccountName without $ or dnsHostName
 598          * or "ntds_guid._msdcs.forest_domain for DC objects */
 599         if (strlen(instanceName) == (strlen(samAccountName) - 1)
 600             && strncasecmp(instanceName, samAccountName, strlen(samAccountName) - 1) == 0) {
 601                 goto success;
 602         } else if (dnsHostName != NULL && strcasecmp(instanceName, dnsHostName) == 0) {
 603                 goto success;
 604         } else if (is_dc) {
 605                 const char *guid_str;
 606                 guid_str = talloc_asprintf(mem_ctx,"%s._msdcs.%s",
 607                                            ntds_guid,
 608                                            forest_name);
 609                 if (strcasecmp(instanceName, guid_str) == 0) {
 610                         goto success;
 611                 }
 612         }
 613
 614 fail:
 615         krb5_free_principal(krb_ctx, principal);
 616         krb5_free_context(krb_ctx);
 617         return LDB_ERR_CONSTRAINT_VIOLATION;
 618
 619 success:
 620         krb5_free_principal(krb_ctx, principal);
 621         krb5_free_context(krb_ctx);
 622         return LDB_SUCCESS;
 623 }
 624
 625 static int acl_check_spn(TALLOC_CTX *mem_ctx,
 626                          struct ldb_module *module,
 627                          struct ldb_request *req,
 628                          struct security_descriptor *sd,
 629                          struct dom_sid *sid,
 630                          const struct GUID *oc_guid,
 631                          const struct dsdb_attribute *attr)
 632 {
 633         int ret;
 634         unsigned int i;
 635         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 636         struct ldb_context *ldb = ldb_module_get_ctx(module);
 637         struct ldb_result *acl_res;
 638         struct ldb_result *netbios_res;
 639         struct ldb_message_element *el;
 640         struct ldb_dn *partitions_dn = samdb_partitions_dn(ldb, tmp_ctx);
 641         uint32_t userAccountControl;
 642         const char *samAccountName;
 643         const char *dnsHostName;
 644         const char *netbios_name;
 645         struct GUID ntds;
 646         char *ntds_guid = NULL;
 647
 648         static const char *acl_attrs[] = {
 649                 "samAccountName",
 650                 "dnsHostName",
 651                 "userAccountControl",
 652                 NULL
 653         };
 654         static const char *netbios_attrs[] = {
 655                 "nETBIOSName",
 656                 NULL
 657         };
 658
 659         /* if we have wp, we can do whatever we like */
 660         if (acl_check_access_on_attribute(module,
 661                                           tmp_ctx,
 662                                           sd,
 663                                           sid,
 664                                           SEC_ADS_WRITE_PROP,
 665                                           attr) == LDB_SUCCESS) {
 666                 talloc_free(tmp_ctx);
 667                 return LDB_SUCCESS;
 668         }
 669
 670         ret = acl_check_extended_right(tmp_ctx, sd, acl_user_token(module),
 671                                        GUID_DRS_VALIDATE_SPN,
 672                                        SEC_ADS_SELF_WRITE,
 673                                        sid);
 674
 675         if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
 676                 dsdb_acl_debug(sd, acl_user_token(module),
 677                                req->op.mod.message->dn,
 678                                true,
 679                                10);
 680                 talloc_free(tmp_ctx);
 681                 return ret;
 682         }
 683
 684         ret = dsdb_module_search_dn(module, tmp_ctx,
 685                                     &acl_res, req->op.mod.message->dn,
 686                                     acl_attrs,
 687                                     DSDB_FLAG_NEXT_MODULE |
 688                                     DSDB_FLAG_AS_SYSTEM |
 689                                     DSDB_SEARCH_SHOW_RECYCLED,
 690                                     req);
 691         if (ret != LDB_SUCCESS) {
 692                 talloc_free(tmp_ctx);
 693                 return ret;
 694         }
 695
 696         userAccountControl = ldb_msg_find_attr_as_uint(acl_res->msgs[0], "userAccountControl", 0);
 697         dnsHostName = ldb_msg_find_attr_as_string(acl_res->msgs[0], "dnsHostName", NULL);
 698         samAccountName = ldb_msg_find_attr_as_string(acl_res->msgs[0], "samAccountName", NULL);
 699
 700         ret = dsdb_module_search(module, tmp_ctx,
 701                                  &netbios_res, partitions_dn,
 702                                  LDB_SCOPE_ONELEVEL,
 703                                  netbios_attrs,
 704                                  DSDB_FLAG_NEXT_MODULE |
 705                                  DSDB_FLAG_AS_SYSTEM,
 706                                  req,
 707                                  "(ncName=%s)",
 708                                  ldb_dn_get_linearized(ldb_get_default_basedn(ldb)));
 709
 710         netbios_name = ldb_msg_find_attr_as_string(netbios_res->msgs[0], "nETBIOSName", NULL);
 711
 712         el = ldb_msg_find_element(req->op.mod.message, "servicePrincipalName");
 713         if (!el) {
 714                 talloc_free(tmp_ctx);
 715                 return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
 716                                          "Error finding element for servicePrincipalName.");
 717         }
 718
 719         /* NTDSDSA objectGuid of object we are checking SPN for */
 720         if (userAccountControl & (UF_SERVER_TRUST_ACCOUNT | UF_PARTIAL_SECRETS_ACCOUNT)) {
 721                 ret = dsdb_module_find_ntdsguid_for_computer(module, tmp_ctx,
 722                                                              req->op.mod.message->dn, &ntds, req);
 723                 if (ret != LDB_SUCCESS) {
 724                         ldb_asprintf_errstring(ldb, "Failed to find NTDSDSA objectGuid for %s: %s",
 725                                                ldb_dn_get_linearized(req->op.mod.message->dn),
 726                                                ldb_strerror(ret));
 727                         talloc_free(tmp_ctx);
 728                         return LDB_ERR_OPERATIONS_ERROR;
 729                 }
 730                 ntds_guid = GUID_string(tmp_ctx, &ntds);
 731         }
 732
 733         for (i=0; i < el->num_values; i++) {
 734                 ret = acl_validate_spn_value(tmp_ctx,
 735                                              ldb,
 736                                              (char *)el->values[i].data,
 737                                              userAccountControl,
 738                                              samAccountName,
 739                                              dnsHostName,
 740                                              netbios_name,
 741                                              ntds_guid);
 742                 if (ret != LDB_SUCCESS) {
 743                         talloc_free(tmp_ctx);
 744                         return ret;
 745                 }
 746         }
 747         talloc_free(tmp_ctx);
 748         return LDB_SUCCESS;
 749 }
 750
 751 static int acl_add(struct ldb_module *module, struct ldb_request *req)
 752 {
 753         int ret;
 754         struct ldb_dn *parent = ldb_dn_get_parent(req, req->op.add.message->dn);
 755         struct ldb_context *ldb;
 756         const struct dsdb_schema *schema;
 757         struct ldb_message_element *oc_el;
 758         const struct GUID *guid;
 759         struct ldb_dn *nc_root;
 760         struct ldb_control *as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
 761
 762         if (as_system != NULL) {
 763                 as_system->critical = 0;
 764         }
 765
 766         if (dsdb_module_am_system(module) || as_system) {
 767                 return ldb_next_request(module, req);
 768         }
 769         if (ldb_dn_is_special(req->op.add.message->dn)) {
 770                 return ldb_next_request(module, req);
 771         }
 772
 773         ldb = ldb_module_get_ctx(module);
 774
 775         /* Creating an NC. There is probably something we should do here,
 776          * but we will establish that later */
 777
 778         ret = dsdb_find_nc_root(ldb, req, req->op.add.message->dn, &nc_root);
 779         if (ret != LDB_SUCCESS) {
 780                 return ret;
 781         }
 782         if (ldb_dn_compare(nc_root, req->op.add.message->dn) == 0) {
 783                 talloc_free(nc_root);
 784                 return ldb_next_request(module, req);
 785         }
 786         talloc_free(nc_root);
 787
 788         schema = dsdb_get_schema(ldb, req);
 789         if (!schema) {
 790                 return ldb_operr(ldb);
 791         }
 792
 793         oc_el = ldb_msg_find_element(req->op.add.message, "objectClass");
 794         if (!oc_el || oc_el->num_values == 0) {
 795                 ldb_asprintf_errstring(ldb_module_get_ctx(module),
 796                                        "acl: unable to find objectClass on %s\n",
 797                                        ldb_dn_get_linearized(req->op.add.message->dn));
 798                 return ldb_module_done(req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR);
 799         }
 800
 801         guid = class_schemaid_guid_by_lDAPDisplayName(schema,
 802                                                       (char *)oc_el->values[oc_el->num_values-1].data);
 803         ret = dsdb_module_check_access_on_dn(module, req, parent, SEC_ADS_CREATE_CHILD, guid, req);
 804         if (ret != LDB_SUCCESS) {
 805                 return ret;
 806         }
 807         return ldb_next_request(module, req);
 808 }
 809
 810 /* ckecks if modifications are allowed on "Member" attribute */
 811 static int acl_check_self_membership(TALLOC_CTX *mem_ctx,
 812                                      struct ldb_module *module,
 813                                      struct ldb_request *req,
 814                                      struct security_descriptor *sd,
 815                                      struct dom_sid *sid,
 816                                      const struct GUID *oc_guid,
 817                                      const struct dsdb_attribute *attr)
 818 {
 819         int ret;
 820         unsigned int i;
 821         struct ldb_context *ldb = ldb_module_get_ctx(module);
 822         struct ldb_dn *user_dn;
 823         struct ldb_message_element *member_el;
 824         /* if we have wp, we can do whatever we like */
 825         if (acl_check_access_on_attribute(module,
 826                                           mem_ctx,
 827                                           sd,
 828                                           sid,
 829                                           SEC_ADS_WRITE_PROP,
 830                                           attr) == LDB_SUCCESS) {
 831                 return LDB_SUCCESS;
 832         }
 833         /* if we are adding/deleting ourselves, check for self membership */
 834         ret = dsdb_find_dn_by_sid(ldb, mem_ctx,
 835                                   &acl_user_token(module)->sids[PRIMARY_USER_SID_INDEX],
 836                                   &user_dn);
 837         if (ret != LDB_SUCCESS) {
 838                 return ret;
 839         }
 840         member_el = ldb_msg_find_element(req->op.mod.message, "member");
 841         if (!member_el) {
 842                 return ldb_operr(ldb);
 843         }
 844         /* user can only remove oneself */
 845         if (member_el->num_values == 0) {
 846                 return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
 847         }
 848         for (i = 0; i < member_el->num_values; i++) {
 849                 if (strcasecmp((const char *)member_el->values[i].data,
 850                                ldb_dn_get_extended_linearized(mem_ctx, user_dn, 1)) != 0) {
 851                         return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
 852                 }
 853         }
 854         ret = acl_check_extended_right(mem_ctx, sd, acl_user_token(module),
 855                                        GUID_DRS_SELF_MEMBERSHIP,
 856                                        SEC_ADS_SELF_WRITE,
 857                                        sid);
 858         if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
 859                 dsdb_acl_debug(sd, acl_user_token(module),
 860                                req->op.mod.message->dn,
 861                                true,
 862                                10);
 863         }
 864         return ret;
 865 }
 866
 867 static int acl_check_password_rights(TALLOC_CTX *mem_ctx,
 868                                      struct ldb_module *module,
 869                                      struct ldb_request *req,
 870                                      struct security_descriptor *sd,
 871                                      struct dom_sid *sid,
 872                                      const struct GUID *oc_guid,
 873                                      bool userPassword)
 874 {
 875         int ret = LDB_SUCCESS;
 876         unsigned int del_attr_cnt = 0, add_attr_cnt = 0, rep_attr_cnt = 0;
 877         struct ldb_message_element *el;
 878         struct ldb_message *msg;
 879         const char *passwordAttrs[] = { "userPassword", "clearTextPassword",
 880                                         "unicodePwd", "dBCSPwd", NULL }, **l;
 881         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 882
 883         msg = ldb_msg_copy_shallow(tmp_ctx, req->op.mod.message);
 884         if (msg == NULL) {
 885                 return ldb_module_oom(module);
 886         }
 887         for (l = passwordAttrs; *l != NULL; l++) {
 888                 if ((!userPassword) && (ldb_attr_cmp(*l, "userPassword") == 0)) {
 889                         continue;
 890                 }
 891
 892                 while ((el = ldb_msg_find_element(msg, *l)) != NULL) {
 893                         if (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_DELETE) {
 894                                 ++del_attr_cnt;
 895                         }
 896                         if (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_ADD) {
 897                                 ++add_attr_cnt;
 898                         }
 899                         if (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_REPLACE) {
 900                                 ++rep_attr_cnt;
 901                         }
 902                         ldb_msg_remove_element(msg, el);
 903                 }
 904         }
 905
 906         /* single deletes will be handled by the "password_hash" LDB module
 907          * later in the stack, so we let it though here */
 908         if ((del_attr_cnt > 0) && (add_attr_cnt == 0) && (rep_attr_cnt == 0)) {
 909                 talloc_free(tmp_ctx);
 910                 return LDB_SUCCESS;
 911         }
 912
 913         if (ldb_request_get_control(req,
 914                                     DSDB_CONTROL_PASSWORD_CHANGE_OID) != NULL) {
 915                 /* The "DSDB_CONTROL_PASSWORD_CHANGE_OID" control means that we
 916                  * have a user password change and not a set as the message
 917                  * looks like. In it's value blob it contains the NT and/or LM
 918                  * hash of the old password specified by the user.
 919                  * This control is used by the SAMR and "kpasswd" password
 920                  * change mechanisms. */
 921                 ret = acl_check_extended_right(tmp_ctx, sd, acl_user_token(module),
 922                                                GUID_DRS_USER_CHANGE_PASSWORD,
 923                                                SEC_ADS_CONTROL_ACCESS,
 924                                                sid);
 925         }
 926         else if (rep_attr_cnt > 0 || (add_attr_cnt != del_attr_cnt)) {
 927                 ret = acl_check_extended_right(tmp_ctx, sd, acl_user_token(module),
 928                                                GUID_DRS_FORCE_CHANGE_PASSWORD,
 929                                                SEC_ADS_CONTROL_ACCESS,
 930                                                sid);
 931         }
 932         else if (add_attr_cnt == 1 && del_attr_cnt == 1) {
 933                 ret = acl_check_extended_right(tmp_ctx, sd, acl_user_token(module),
 934                                                GUID_DRS_USER_CHANGE_PASSWORD,
 935                                                SEC_ADS_CONTROL_ACCESS,
 936                                                sid);
 937                 /* Very strange, but we get constraint violation in this case */
 938                 if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
 939                         ret = LDB_ERR_CONSTRAINT_VIOLATION;
 940                 }
 941         }
 942         if (ret != LDB_SUCCESS) {
 943                 dsdb_acl_debug(sd, acl_user_token(module),
 944                                req->op.mod.message->dn,
 945                                true,
 946                                10);
 947         }
 948         talloc_free(tmp_ctx);
 949         return ret;
 950 }
 951
 952 static const struct GUID *get_oc_guid_from_message(const struct dsdb_schema *schema,
 953                                                    struct ldb_message *msg)
 954 {
 955         struct ldb_message_element *oc_el;
 956         const struct dsdb_class *object_class;
 957
 958         oc_el = ldb_msg_find_element(msg, "objectClass");
 959         if (!oc_el) {
 960                 return NULL;
 961         }
 962
 963         object_class = dsdb_get_last_structural_class(schema, oc_el);
 964         if (object_class == NULL) {
 965                 return NULL;
 966         }
 967
 968         return &object_class->schemaIDGUID;
 969 }
 970
 971
 972 static int acl_modify(struct ldb_module *module, struct ldb_request *req)
 973 {
 974         int ret;
 975         struct ldb_context *ldb = ldb_module_get_ctx(module);
 976         const struct dsdb_schema *schema;
 977         unsigned int i;
 978         const struct GUID *guid;
 979         uint32_t access_granted;
 980         struct object_tree *root = NULL;
 981         struct object_tree *new_node = NULL;
 982         NTSTATUS status;
 983         struct ldb_result *acl_res;
 984         struct security_descriptor *sd;
 985         struct dom_sid *sid = NULL;
 986         struct ldb_control *as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
 987         bool userPassword = dsdb_user_password_support(module, req, req);
 988         TALLOC_CTX *tmp_ctx = talloc_new(req);
 989         static const char *acl_attrs[] = {
 990                 "nTSecurityDescriptor",
 991                 "objectClass",
 992                 "objectSid",
 993                 NULL
 994         };
 995
 996         if (as_system != NULL) {
 997                 as_system->critical = 0;
 998         }
 999
1000         /* Don't print this debug statement if elements[0].name is going to be NULL */
1001         if(req->op.mod.message->num_elements > 0)
1002         {
1003                 DEBUG(10, ("ldb:acl_modify: %s\n", req->op.mod.message->elements[0].name));
1004         }
1005         if (dsdb_module_am_system(module) || as_system) {
1006                 return ldb_next_request(module, req);
1007         }
1008         if (ldb_dn_is_special(req->op.mod.message->dn)) {
1009                 return ldb_next_request(module, req);
1010         }
1011         ret = dsdb_module_search_dn(module, tmp_ctx, &acl_res, req->op.mod.message->dn,
1012                                     acl_attrs,
1013                                     DSDB_FLAG_NEXT_MODULE |
1014                                     DSDB_FLAG_AS_SYSTEM |
1015                                     DSDB_SEARCH_SHOW_RECYCLED,
1016                                     req);
1017
1018         if (ret != LDB_SUCCESS) {
1019                 goto fail;
1020         }
1021
1022         schema = dsdb_get_schema(ldb, tmp_ctx);
1023         if (!schema) {
1024                 talloc_free(tmp_ctx);
1025                 return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
1026                                  "acl_modify: Error obtaining schema.");
1027         }
1028
1029         ret = dsdb_get_sd_from_ldb_message(ldb, tmp_ctx, acl_res->msgs[0], &sd);
1030         if (ret != LDB_SUCCESS) {
1031                 talloc_free(tmp_ctx);
1032                 return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
1033                                  "acl_modify: Error retrieving security descriptor.");
1034         }
1035         /* Theoretically we pass the check if the object has no sd */
1036         if (!sd) {
1037                 goto success;
1038         }
1039
1040         guid = get_oc_guid_from_message(schema, acl_res->msgs[0]);
1041         if (!guid) {
1042                 talloc_free(tmp_ctx);
1043                 return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
1044                                  "acl_modify: Error retrieving object class GUID.");
1045         }
1046         sid = samdb_result_dom_sid(req, acl_res->msgs[0], "objectSid");
1047         if (!insert_in_object_tree(tmp_ctx, guid, SEC_ADS_WRITE_PROP,
1048                                    &root, &new_node)) {
1049                 talloc_free(tmp_ctx);
1050                 return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
1051                                  "acl_modify: Error adding new node in object tree.");
1052         }
1053         for (i=0; i < req->op.mod.message->num_elements; i++){
1054                 const struct dsdb_attribute *attr;
1055                 attr = dsdb_attribute_by_lDAPDisplayName(schema,
1056                                                          req->op.mod.message->elements[i].name);
1057
1058                 if (ldb_attr_cmp("nTSecurityDescriptor", req->op.mod.message->elements[i].name) == 0) {
1059                         uint32_t sd_flags = dsdb_request_sd_flags(req, NULL);
1060                         uint32_t access_mask = 0;
1061
1062                         if (sd_flags & (SECINFO_OWNER|SECINFO_GROUP)) {
1063                                 access_mask |= SEC_STD_WRITE_OWNER;
1064                         }
1065                         if (sd_flags & SECINFO_DACL) {
1066                                 access_mask |= SEC_STD_WRITE_DAC;
1067                         }
1068                         if (sd_flags & SECINFO_SACL) {
1069                                 access_mask |= SEC_FLAG_SYSTEM_SECURITY;
1070                         }
1071
1072                         status = sec_access_check_ds(sd, acl_user_token(module),
1073                                              access_mask,
1074                                              &access_granted,
1075                                              NULL,
1076                                              sid);
1077
1078                         if (!NT_STATUS_IS_OK(status)) {
1079                                 ldb_asprintf_errstring(ldb_module_get_ctx(module),
1080                                                        "Object %s has no write dacl access\n",
1081                                                        ldb_dn_get_linearized(req->op.mod.message->dn));
1082                                 dsdb_acl_debug(sd,
1083                                                acl_user_token(module),
1084                                                req->op.mod.message->dn,
1085                                                true,
1086                                                10);
1087                                 ret = LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
1088                                 goto fail;
1089                         }
1090                 }
1091                 else if (ldb_attr_cmp("member", req->op.mod.message->elements[i].name) == 0) {
1092                         ret = acl_check_self_membership(tmp_ctx,
1093                                                         module,
1094                                                         req,
1095                                                         sd,
1096                                                         sid,
1097                                                         guid,
1098                                                         attr);
1099                         if (ret != LDB_SUCCESS) {
1100                                 goto fail;
1101                         }
1102                 }
1103                 else if (ldb_attr_cmp("dBCSPwd", req->op.mod.message->elements[i].name) == 0) {
1104                         /* this one is not affected by any rights, we should let it through
1105                            so that passwords_hash returns the correct error */
1106                         continue;
1107                 }
1108                 else if (ldb_attr_cmp("unicodePwd", req->op.mod.message->elements[i].name) == 0 ||
1109                          (userPassword && ldb_attr_cmp("userPassword", req->op.mod.message->elements[i].name) == 0) ||
1110                          ldb_attr_cmp("clearTextPassword", req->op.mod.message->elements[i].name) == 0) {
1111                         ret = acl_check_password_rights(tmp_ctx,
1112                                                         module,
1113                                                         req,
1114                                                         sd,
1115                                                         sid,
1116                                                         guid,
1117                                                         userPassword);
1118                         if (ret != LDB_SUCCESS) {
1119                                 goto fail;
1120                         }
1121                 } else if (ldb_attr_cmp("servicePrincipalName", req->op.mod.message->elements[i].name) == 0) {
1122                         ret = acl_check_spn(tmp_ctx,
1123                                             module,
1124                                             req,
1125                                             sd,
1126                                             sid,
1127                                             guid,
1128                                             attr);
1129                         if (ret != LDB_SUCCESS) {
1130                                 goto fail;
1131                         }
1132                 } else {
1133
1134                 /* This basic attribute existence check with the right errorcode
1135                  * is needed since this module is the first one which requests
1136                  * schema attribute information.
1137                  * The complete attribute checking is done in the
1138                  * "objectclass_attrs" module behind this one.
1139                  */
1140                         if (!attr) {
1141                                 ldb_asprintf_errstring(ldb, "acl_modify: attribute '%s' on entry '%s' was not found in the schema!",
1142                                                        req->op.mod.message->elements[i].name,
1143                                                ldb_dn_get_linearized(req->op.mod.message->dn));
1144                                 ret =  LDB_ERR_NO_SUCH_ATTRIBUTE;
1145                                 goto fail;
1146                         }
1147                         if (!insert_in_object_tree(tmp_ctx,
1148                                                    &attr->attributeSecurityGUID, SEC_ADS_WRITE_PROP,
1149                                                    &new_node, &new_node)) {
1150                                 ldb_asprintf_errstring(ldb_module_get_ctx(module),
1151                                                        "acl_modify: cannot add to object tree securityGUID\n");
1152                                 ret = LDB_ERR_OPERATIONS_ERROR;
1153                                 goto fail;
1154                         }
1155
1156                         if (!insert_in_object_tree(tmp_ctx,
1157                                                    &attr->schemaIDGUID, SEC_ADS_WRITE_PROP, &new_node, &new_node)) {
1158                                 ldb_asprintf_errstring(ldb_module_get_ctx(module),
1159                                                        "acl_modify: cannot add to object tree attributeGUID\n");
1160                                 ret = LDB_ERR_OPERATIONS_ERROR;
1161                                 goto fail;
1162                         }
1163                 }
1164         }
1165
1166         if (root->num_of_children > 0) {
1167                 status = sec_access_check_ds(sd, acl_user_token(module),
1168                                              SEC_ADS_WRITE_PROP,
1169                                              &access_granted,
1170                                              root,
1171                                              sid);
1172
1173                 if (!NT_STATUS_IS_OK(status)) {
1174                         ldb_asprintf_errstring(ldb_module_get_ctx(module),
1175                                                "Object %s has no write property access\n",
1176                                                ldb_dn_get_linearized(req->op.mod.message->dn));
1177                         dsdb_acl_debug(sd,
1178                                        acl_user_token(module),
1179                                        req->op.mod.message->dn,
1180                                        true,
1181                                        10);
1182                         ret = LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
1183                         goto fail;
1184                 }
1185         }
1186
1187 success:
1188         talloc_free(tmp_ctx);
1189         return ldb_next_request(module, req);
1190 fail:
1191         talloc_free(tmp_ctx);
1192         return ret;
1193 }
1194
1195 /* similar to the modify for the time being.
1196  * We need to consider the special delete tree case, though - TODO */
1197 static int acl_delete(struct ldb_module *module, struct ldb_request *req)
1198 {
1199         int ret;
1200         struct ldb_dn *parent = ldb_dn_get_parent(req, req->op.del.dn);
1201         struct ldb_context *ldb;
1202         struct ldb_dn *nc_root;
1203         struct ldb_control *as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
1204
1205         if (as_system != NULL) {
1206                 as_system->critical = 0;
1207         }
1208
1209         DEBUG(10, ("ldb:acl_delete: %s\n", ldb_dn_get_linearized(req->op.del.dn)));
1210         if (dsdb_module_am_system(module) || as_system) {
1211                 return ldb_next_request(module, req);
1212         }
1213         if (ldb_dn_is_special(req->op.del.dn)) {
1214                 return ldb_next_request(module, req);
1215         }
1216
1217         ldb = ldb_module_get_ctx(module);
1218
1219         /* Make sure we aren't deleting a NC */
1220
1221         ret = dsdb_find_nc_root(ldb, req, req->op.del.dn, &nc_root);
1222         if (ret != LDB_SUCCESS) {
1223                 return ret;
1224         }
1225         if (ldb_dn_compare(nc_root, req->op.del.dn) == 0) {
1226                 talloc_free(nc_root);
1227                 DEBUG(10,("acl:deleting a NC\n"));
1228                 /* Windows returns "ERR_UNWILLING_TO_PERFORM */
1229                 return ldb_module_done(req, NULL, NULL,
1230                                        LDB_ERR_UNWILLING_TO_PERFORM);
1231         }
1232         talloc_free(nc_root);
1233
1234         if (ldb_request_get_control(req, LDB_CONTROL_TREE_DELETE_OID)) {
1235                 ret = dsdb_module_check_access_on_dn(module, req,
1236                                                      req->op.del.dn,
1237                                                      SEC_ADS_DELETE_TREE, NULL,
1238                                                      req);
1239                 if (ret != LDB_SUCCESS) {
1240                         return ret;
1241                 }
1242
1243                 return ldb_next_request(module, req);
1244         }
1245
1246         /* First check if we have delete object right */
1247         ret = dsdb_module_check_access_on_dn(module, req, req->op.del.dn,
1248                                              SEC_STD_DELETE, NULL, req);
1249         if (ret == LDB_SUCCESS) {
1250                 return ldb_next_request(module, req);
1251         }
1252
1253         /* Nope, we don't have delete object. Lets check if we have delete
1254          * child on the parent */
1255         ret = dsdb_module_check_access_on_dn(module, req, parent,
1256                                              SEC_ADS_DELETE_CHILD, NULL, req);
1257         if (ret != LDB_SUCCESS) {
1258                 return ret;
1259         }
1260
1261         return ldb_next_request(module, req);
1262 }
1263
1264 static int acl_rename(struct ldb_module *module, struct ldb_request *req)
1265 {
1266         int ret;
1267         struct ldb_dn *oldparent = ldb_dn_get_parent(req, req->op.rename.olddn);
1268         struct ldb_dn *newparent = ldb_dn_get_parent(req, req->op.rename.newdn);
1269         const struct dsdb_schema *schema;
1270         struct ldb_context *ldb;
1271         struct security_descriptor *sd = NULL;
1272         struct dom_sid *sid = NULL;
1273         struct ldb_result *acl_res;
1274         const struct GUID *guid;
1275         struct ldb_dn *nc_root;
1276         struct object_tree *root = NULL;
1277         struct object_tree *new_node = NULL;
1278         struct ldb_control *as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
1279         TALLOC_CTX *tmp_ctx = talloc_new(req);
1280         NTSTATUS status;
1281         uint32_t access_granted;
1282         const char *rdn_name;
1283         static const char *acl_attrs[] = {
1284                 "nTSecurityDescriptor",
1285                 "objectClass",
1286                 "objectSid",
1287                 NULL
1288         };
1289
1290         if (as_system != NULL) {
1291                 as_system->critical = 0;
1292         }
1293
1294         DEBUG(10, ("ldb:acl_rename: %s\n", ldb_dn_get_linearized(req->op.rename.olddn)));
1295         if (dsdb_module_am_system(module) || as_system) {
1296                 return ldb_next_request(module, req);
1297         }
1298         if (ldb_dn_is_special(req->op.rename.olddn)) {
1299                 return ldb_next_request(module, req);
1300         }
1301
1302         ldb = ldb_module_get_ctx(module);
1303
1304         /* Make sure we aren't renaming/moving a NC */
1305
1306         ret = dsdb_find_nc_root(ldb, req, req->op.rename.olddn, &nc_root);
1307         if (ret != LDB_SUCCESS) {
1308                 return ret;
1309         }
1310         if (ldb_dn_compare(nc_root, req->op.rename.olddn) == 0) {
1311                 talloc_free(nc_root);
1312                 DEBUG(10,("acl:renaming/moving a NC\n"));
1313                 /* Windows returns "ERR_UNWILLING_TO_PERFORM */
1314                 return ldb_module_done(req, NULL, NULL,
1315                                        LDB_ERR_UNWILLING_TO_PERFORM);
1316         }
1317         talloc_free(nc_root);
1318
1319         /* Look for the parent */
1320
1321         ret = dsdb_module_search_dn(module, tmp_ctx, &acl_res,
1322                                     req->op.rename.olddn, acl_attrs,
1323                                     DSDB_FLAG_NEXT_MODULE |
1324                                     DSDB_FLAG_AS_SYSTEM |
1325                                     DSDB_SEARCH_SHOW_RECYCLED, req);
1326         /* we sould be able to find the parent */
1327         if (ret != LDB_SUCCESS) {
1328                 DEBUG(10,("acl: failed to find object %s\n",
1329                           ldb_dn_get_linearized(req->op.rename.olddn)));
1330                 talloc_free(tmp_ctx);
1331                 return ret;
1332         }
1333
1334         schema = dsdb_get_schema(ldb, acl_res);
1335         if (!schema) {
1336                 talloc_free(tmp_ctx);
1337                 return ldb_operr(ldb);
1338         }
1339
1340         guid = get_oc_guid_from_message(schema, acl_res->msgs[0]);
1341         if (!insert_in_object_tree(tmp_ctx, guid, SEC_ADS_WRITE_PROP,
1342                                    &root, &new_node)) {
1343                 talloc_free(tmp_ctx);
1344                 return ldb_operr(ldb);
1345         };
1346
1347         guid = attribute_schemaid_guid_by_lDAPDisplayName(schema,
1348                                                           "name");
1349         if (!insert_in_object_tree(tmp_ctx, guid, SEC_ADS_WRITE_PROP,
1350                                    &new_node, &new_node)) {
1351                 talloc_free(tmp_ctx);
1352                 return ldb_operr(ldb);
1353         };
1354
1355         rdn_name = ldb_dn_get_rdn_name(req->op.rename.olddn);
1356         if (rdn_name == NULL) {
1357                 talloc_free(tmp_ctx);
1358                 return ldb_operr(ldb);
1359         }
1360         guid = attribute_schemaid_guid_by_lDAPDisplayName(schema,
1361                                                           rdn_name);
1362         if (!insert_in_object_tree(tmp_ctx, guid, SEC_ADS_WRITE_PROP,
1363                                    &new_node, &new_node)) {
1364                 talloc_free(tmp_ctx);
1365                 return ldb_operr(ldb);
1366         };
1367
1368         ret = dsdb_get_sd_from_ldb_message(ldb, req, acl_res->msgs[0], &sd);
1369
1370         if (ret != LDB_SUCCESS) {
1371                 talloc_free(tmp_ctx);
1372                 return ldb_operr(ldb);
1373         }
1374         /* Theoretically we pass the check if the object has no sd */
1375         if (!sd) {
1376                 talloc_free(tmp_ctx);
1377                 return LDB_SUCCESS;
1378         }
1379         sid = samdb_result_dom_sid(req, acl_res->msgs[0], "objectSid");
1380         status = sec_access_check_ds(sd, acl_user_token(module),
1381                                      SEC_ADS_WRITE_PROP,
1382                                      &access_granted,
1383                                      root,
1384                                      sid);
1385
1386         if (!NT_STATUS_IS_OK(status)) {
1387                 ldb_asprintf_errstring(ldb_module_get_ctx(module),
1388                                        "Object %s has no wp on name\n",
1389                                        ldb_dn_get_linearized(req->op.rename.olddn));
1390                 dsdb_acl_debug(sd,
1391                           acl_user_token(module),
1392                           req->op.rename.olddn,
1393                           true,
1394                           10);
1395                 talloc_free(tmp_ctx);
1396                 return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
1397         }
1398
1399         if (ldb_dn_compare(oldparent, newparent) == 0) {
1400                 /* regular rename, not move, nothing more to do */
1401                 talloc_free(tmp_ctx);
1402                 return ldb_next_request(module, req);
1403         }
1404
1405         /* new parent should have create child */
1406         root = NULL;
1407         new_node = NULL;
1408         guid = get_oc_guid_from_message(schema, acl_res->msgs[0]);
1409         if (!guid) {
1410                 ldb_asprintf_errstring(ldb_module_get_ctx(module),
1411                                        "acl:renamed object has no object class\n");
1412                 talloc_free(tmp_ctx);
1413                 return ldb_module_done(req, NULL, NULL,  LDB_ERR_OPERATIONS_ERROR);
1414         }
1415
1416         ret = dsdb_module_check_access_on_dn(module, req, newparent, SEC_ADS_CREATE_CHILD, guid, req);
1417         if (ret != LDB_SUCCESS) {
1418                 ldb_asprintf_errstring(ldb_module_get_ctx(module),
1419                                        "acl:access_denied renaming %s",
1420                                        ldb_dn_get_linearized(req->op.rename.olddn));
1421                 talloc_free(tmp_ctx);
1422                 return ret;
1423         }
1424         /* do we have delete object on the object? */
1425
1426         status = sec_access_check_ds(sd, acl_user_token(module),
1427                                      SEC_STD_DELETE,
1428                                      &access_granted,
1429                                      NULL,
1430                                      sid);
1431
1432         if (NT_STATUS_IS_OK(status)) {
1433                 talloc_free(tmp_ctx);
1434                 return ldb_next_request(module, req);
1435         }
1436         /* what about delete child on the current parent */
1437         ret = dsdb_module_check_access_on_dn(module, req, oldparent, SEC_ADS_DELETE_CHILD, NULL, req);
1438         if (ret != LDB_SUCCESS) {
1439                 ldb_asprintf_errstring(ldb_module_get_ctx(module),
1440                                        "acl:access_denied renaming %s", ldb_dn_get_linearized(req->op.rename.olddn));
1441                 talloc_free(tmp_ctx);
1442                 return ldb_module_done(req, NULL, NULL, ret);
1443         }
1444
1445         talloc_free(tmp_ctx);
1446
1447         return ldb_next_request(module, req);
1448 }
1449
1450 static int acl_search_update_confidential_attrs(struct acl_context *ac,
1451                                                 struct acl_private *data)
1452 {
1453         struct dsdb_attribute *a;
1454         uint32_t n = 0;
1455
1456         if (data->acl_search) {
1457                 /*
1458                  * If acl:search is activated, the acl_read module
1459                  * protects confidential attributes.
1460                  */
1461                 return LDB_SUCCESS;
1462         }
1463
1464         if ((ac->schema == data->cached_schema_ptr) &&
1465             (ac->schema->loaded_usn == data->cached_schema_loaded_usn) &&
1466             (ac->schema->metadata_usn == data->cached_schema_metadata_usn))
1467         {
1468                 return LDB_SUCCESS;
1469         }
1470
1471         data->cached_schema_ptr = NULL;
1472         data->cached_schema_loaded_usn = 0;
1473         data->cached_schema_metadata_usn = 0;
1474         TALLOC_FREE(data->confidential_attrs);
1475
1476         if (ac->schema == NULL) {
1477                 return LDB_SUCCESS;
1478         }
1479
1480         for (a = ac->schema->attributes; a; a = a->next) {
1481                 const char **attrs = data->confidential_attrs;
1482
1483                 if (!(a->searchFlags & SEARCH_FLAG_CONFIDENTIAL)) {
1484                         continue;
1485                 }
1486
1487                 attrs = talloc_realloc(data, attrs, const char *, n + 2);
1488                 if (attrs == NULL) {
1489                         TALLOC_FREE(data->confidential_attrs);
1490                         return ldb_module_oom(ac->module);
1491                 }
1492
1493                 attrs[n] = a->lDAPDisplayName;
1494                 attrs[n+1] = NULL;
1495                 n++;
1496
1497                 data->confidential_attrs = attrs;
1498         }
1499
1500         data->cached_schema_ptr = ac->schema;
1501         data->cached_schema_loaded_usn = ac->schema->loaded_usn;
1502         data->cached_schema_metadata_usn = ac->schema->metadata_usn;
1503
1504         return LDB_SUCCESS;
1505 }
1506
1507 static int acl_search_callback(struct ldb_request *req, struct ldb_reply *ares)
1508 {
1509         struct acl_context *ac;
1510         struct acl_private *data;
1511         struct ldb_result *acl_res;
1512         static const char *acl_attrs[] = {
1513                 "objectClass",
1514                 "nTSecurityDescriptor",
1515                 "objectSid",
1516                 NULL
1517         };
1518         int ret;
1519         unsigned int i;
1520
1521         ac = talloc_get_type(req->context, struct acl_context);
1522         data = talloc_get_type(ldb_module_get_private(ac->module), struct acl_private);
1523         if (!ares) {
1524                 return ldb_module_done(ac->req, NULL, NULL,
1525                                        LDB_ERR_OPERATIONS_ERROR);
1526         }
1527         if (ares->error != LDB_SUCCESS) {
1528                 return ldb_module_done(ac->req, ares->controls,
1529                                        ares->response, ares->error);
1530         }
1531
1532         switch (ares->type) {
1533         case LDB_REPLY_ENTRY:
1534                 if (ac->constructed_attrs) {
1535                         ret = dsdb_module_search_dn(ac->module, ac, &acl_res, ares->message->dn,
1536                                                     acl_attrs,
1537                                                     DSDB_FLAG_NEXT_MODULE |
1538                                                     DSDB_FLAG_AS_SYSTEM |
1539                                                     DSDB_SEARCH_SHOW_RECYCLED,
1540                                                     req);
1541                         if (ret != LDB_SUCCESS) {
1542                                 return ldb_module_done(ac->req, NULL, NULL, ret);
1543                         }
1544                 }
1545
1546                 if (ac->allowedAttributes || ac->allowedAttributesEffective) {
1547                         ret = acl_allowedAttributes(ac->module, ac->schema,
1548                                                     acl_res->msgs[0],
1549                                                     ares->message, ac);
1550                         if (ret != LDB_SUCCESS) {
1551                                 return ldb_module_done(ac->req, NULL, NULL, ret);
1552                         }
1553                 }
1554
1555                 if (ac->allowedChildClasses) {
1556                         ret = acl_childClasses(ac->module, ac->schema,
1557                                                acl_res->msgs[0],
1558                                                ares->message,
1559                                                "allowedChildClasses");
1560                         if (ret != LDB_SUCCESS) {
1561                                 return ldb_module_done(ac->req, NULL, NULL, ret);
1562                         }
1563                 }
1564
1565                 if (ac->allowedChildClassesEffective) {
1566                         ret = acl_childClassesEffective(ac->module, ac->schema,
1567                                                         acl_res->msgs[0],
1568                                                         ares->message, ac);
1569                         if (ret != LDB_SUCCESS) {
1570                                 return ldb_module_done(ac->req, NULL, NULL, ret);
1571                         }
1572                 }
1573
1574                 if (ac->sDRightsEffective) {
1575                         ret = acl_sDRightsEffective(ac->module,
1576                                                     acl_res->msgs[0],
1577                                                     ares->message, ac);
1578                         if (ret != LDB_SUCCESS) {
1579                                 return ldb_module_done(ac->req, NULL, NULL, ret);
1580                         }
1581                 }
1582
1583                 if (data == NULL) {
1584                         return ldb_module_send_entry(ac->req, ares->message,
1585                                                      ares->controls);
1586                 }
1587
1588                 if (ac->am_system) {
1589                         return ldb_module_send_entry(ac->req, ares->message,
1590                                                      ares->controls);
1591                 }
1592
1593                 if (data->password_attrs != NULL) {
1594                         for (i = 0; data->password_attrs[i]; i++) {
1595                                 if ((!ac->userPassword) &&
1596                                     (ldb_attr_cmp(data->password_attrs[i],
1597                                                   "userPassword") == 0))
1598                                 {
1599                                                 continue;
1600                                 }
1601
1602                                 ldb_msg_remove_attr(ares->message, data->password_attrs[i]);
1603                         }
1604                 }
1605
1606                 if (ac->am_administrator) {
1607                         return ldb_module_send_entry(ac->req, ares->message,
1608                                                      ares->controls);
1609                 }
1610
1611                 ret = acl_search_update_confidential_attrs(ac, data);
1612                 if (ret != LDB_SUCCESS) {
1613                         return ret;
1614                 }
1615
1616                 if (data->confidential_attrs != NULL) {
1617                         for (i = 0; data->confidential_attrs[i]; i++) {
1618                                 ldb_msg_remove_attr(ares->message,
1619                                                     data->confidential_attrs[i]);
1620                         }
1621                 }
1622
1623                 return ldb_module_send_entry(ac->req, ares->message, ares->controls);
1624
1625         case LDB_REPLY_REFERRAL:
1626                 return ldb_module_send_referral(ac->req, ares->referral);
1627
1628         case LDB_REPLY_DONE:
1629                 return ldb_module_done(ac->req, ares->controls,
1630                                        ares->response, LDB_SUCCESS);
1631
1632         }
1633         return LDB_SUCCESS;
1634 }
1635
1636 static int acl_search(struct ldb_module *module, struct ldb_request *req)
1637 {
1638         struct ldb_context *ldb;
1639         struct acl_context *ac;
1640         struct ldb_parse_tree *down_tree;
1641         struct ldb_request *down_req;
1642         struct acl_private *data;
1643         int ret;
1644         unsigned int i;
1645
1646         ldb = ldb_module_get_ctx(module);
1647
1648         ac = talloc_zero(req, struct acl_context);
1649         if (ac == NULL) {
1650                 return ldb_oom(ldb);
1651         }
1652         data = talloc_get_type(ldb_module_get_private(module), struct acl_private);
1653
1654         ac->module = module;
1655         ac->req = req;
1656         ac->am_system = dsdb_module_am_system(module);
1657         ac->am_administrator = dsdb_module_am_administrator(module);
1658         ac->constructed_attrs = false;
1659         ac->modify_search = true;
1660         ac->allowedAttributes = ldb_attr_in_list(req->op.search.attrs, "allowedAttributes");
1661         ac->allowedAttributesEffective = ldb_attr_in_list(req->op.search.attrs, "allowedAttributesEffective");
1662         ac->allowedChildClasses = ldb_attr_in_list(req->op.search.attrs, "allowedChildClasses");
1663         ac->allowedChildClassesEffective = ldb_attr_in_list(req->op.search.attrs, "allowedChildClassesEffective");
1664         ac->sDRightsEffective = ldb_attr_in_list(req->op.search.attrs, "sDRightsEffective");
1665         ac->userPassword = dsdb_user_password_support(module, ac, req);
1666         ac->schema = dsdb_get_schema(ldb, ac);
1667
1668         ac->constructed_attrs |= ac->allowedAttributes;
1669         ac->constructed_attrs |= ac->allowedChildClasses;
1670         ac->constructed_attrs |= ac->allowedChildClassesEffective;
1671         ac->constructed_attrs |= ac->allowedAttributesEffective;
1672         ac->constructed_attrs |= ac->sDRightsEffective;
1673
1674         if (data == NULL) {
1675                 ac->modify_search = false;
1676         }
1677         if (ac->am_system) {
1678                 ac->modify_search = false;
1679         }
1680
1681         if (!ac->constructed_attrs && !ac->modify_search) {
1682                 return ldb_next_request(module, req);
1683         }
1684
1685         ret = acl_search_update_confidential_attrs(ac, data);
1686         if (ret != LDB_SUCCESS) {
1687                 return ret;
1688         }
1689
1690         down_tree = ldb_parse_tree_copy_shallow(ac, req->op.search.tree);
1691         if (down_tree == NULL) {
1692                 return ldb_oom(ldb);
1693         }
1694
1695         if (!ac->am_system && data->password_attrs) {
1696                 for (i = 0; data->password_attrs[i]; i++) {
1697                         if ((!ac->userPassword) &&
1698                             (ldb_attr_cmp(data->password_attrs[i],
1699                                           "userPassword") == 0))
1700                         {
1701                                 continue;
1702                         }
1703
1704                         ldb_parse_tree_attr_replace(down_tree,
1705                                                     data->password_attrs[i],
1706                                                     "kludgeACLredactedattribute");
1707                 }
1708         }
1709
1710         if (!ac->am_system && !ac->am_administrator && data->confidential_attrs) {
1711                 for (i = 0; data->confidential_attrs[i]; i++) {
1712                         ldb_parse_tree_attr_replace(down_tree,
1713                                                     data->confidential_attrs[i],
1714                                                     "kludgeACLredactedattribute");
1715                 }
1716         }
1717
1718         ret = ldb_build_search_req_ex(&down_req,
1719                                       ldb, ac,
1720                                       req->op.search.base,
1721                                       req->op.search.scope,
1722                                       down_tree,
1723                                       req->op.search.attrs,
1724                                       req->controls,
1725                                       ac, acl_search_callback,
1726                                       req);
1727         LDB_REQ_SET_LOCATION(down_req);
1728         if (ret != LDB_SUCCESS) {
1729                 return ret;
1730         }
1731         /* perform the search */
1732         return ldb_next_request(module, down_req);
1733 }
1734
1735 static int acl_extended(struct ldb_module *module, struct ldb_request *req)
1736 {
1737         struct ldb_context *ldb = ldb_module_get_ctx(module);
1738         struct ldb_control *as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
1739
1740         /* allow everybody to read the sequence number */
1741         if (strcmp(req->op.extended.oid,
1742                    LDB_EXTENDED_SEQUENCE_NUMBER) == 0) {
1743                 return ldb_next_request(module, req);
1744         }
1745
1746         if (dsdb_module_am_system(module) ||
1747             dsdb_module_am_administrator(module) || as_system) {
1748                 return ldb_next_request(module, req);
1749         } else {
1750                 ldb_asprintf_errstring(ldb,
1751                                        "acl_extended: "
1752                                        "attempted database modify not permitted. "
1753                                        "User %s is not SYSTEM or an administrator",
1754                                        acl_user_name(req, module));
1755                 return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
1756         }
1757 }
1758
1759 static const struct ldb_module_ops ldb_acl_module_ops = {
1760         .name              = "acl",
1761         .search            = acl_search,
1762         .add               = acl_add,
1763         .modify            = acl_modify,
1764         .del               = acl_delete,
1765         .rename            = acl_rename,
1766         .extended          = acl_extended,
1767         .init_context      = acl_module_init
1768 };
1769
1770 int ldb_acl_module_init(const char *version)
1771 {
1772         LDB_MODULE_CHECK_VERSION(version);
1773         return ldb_register_module(&ldb_acl_module_ops);
1774 }