diff options
Diffstat (limited to 'source4/dsdb/common/dsdb_access.c')
| -rw-r--r-- | source4/dsdb/common/dsdb_access.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/source4/dsdb/common/dsdb_access.c b/source4/dsdb/common/dsdb_access.c new file mode 100644 index 0000000..6edae35 --- /dev/null +++ b/source4/dsdb/common/dsdb_access.c @@ -0,0 +1,183 @@ +/* + ldb database library + + Copyright (C) Nadezhda Ivanova 2010 + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +/* + * Name: dsdb_access + * + * Description: utility functions for access checking on objects + * + * Authors: Nadezhda Ivanova + */ + +#include "includes.h" +#include "ldb.h" +#include "ldb_module.h" +#include "ldb_errors.h" +#include "libcli/security/security.h" +#include "librpc/gen_ndr/ndr_security.h" +#include "libcli/ldap/ldap_ndr.h" +#include "param/param.h" +#include "auth/auth.h" +#include "dsdb/samdb/samdb.h" +#include "dsdb/common/util.h" + +void dsdb_acl_debug(struct security_descriptor *sd, + struct security_token *token, + struct ldb_dn *dn, + bool denied, + int level) +{ + if (denied) { + DEBUG(level, ("Access on %s denied\n", ldb_dn_get_linearized(dn))); + } else { + DEBUG(level, ("Access on %s granted\n", ldb_dn_get_linearized(dn))); + } + + DEBUG(level,("Security context: %s\n", + ndr_print_struct_string(0,(ndr_print_fn_t)ndr_print_security_token,"", token))); + DEBUG(level,("Security descriptor: %s\n", + ndr_print_struct_string(0,(ndr_print_fn_t)ndr_print_security_descriptor,"", sd))); +} + +int dsdb_get_sd_from_ldb_message(struct ldb_context *ldb, + TALLOC_CTX *mem_ctx, + struct ldb_message *acl_res, + struct security_descriptor **sd) +{ + struct ldb_message_element *sd_element; + enum ndr_err_code ndr_err; + + sd_element = ldb_msg_find_element(acl_res, "nTSecurityDescriptor"); + if (sd_element == NULL) { + return ldb_error(ldb, LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS, + "nTSecurityDescriptor is missing"); + } + *sd = talloc(mem_ctx, struct security_descriptor); + if(!*sd) { + return ldb_oom(ldb); + } + ndr_err = ndr_pull_struct_blob(&sd_element->values[0], *sd, *sd, + (ndr_pull_flags_fn_t)ndr_pull_security_descriptor); + + if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) { + TALLOC_FREE(*sd); + return ldb_operr(ldb); + } + + return LDB_SUCCESS; +} + +int dsdb_check_access_on_dn_internal(struct ldb_context *ldb, + struct ldb_result *acl_res, + TALLOC_CTX *mem_ctx, + struct security_token *token, + struct ldb_dn *dn, + uint32_t access_mask, + const struct GUID *guid) +{ + struct security_descriptor *sd = NULL; + struct dom_sid *sid = NULL; + struct object_tree *root = NULL; + NTSTATUS status; + uint32_t access_granted; + int ret; + + ret = dsdb_get_sd_from_ldb_message(ldb, mem_ctx, acl_res->msgs[0], &sd); + if (ret != LDB_SUCCESS) { + return ldb_operr(ldb); + } + + sid = samdb_result_dom_sid(mem_ctx, acl_res->msgs[0], "objectSid"); + if (guid) { + if (!insert_in_object_tree(mem_ctx, guid, access_mask, NULL, + &root)) { + TALLOC_FREE(sd); + TALLOC_FREE(sid); + return ldb_operr(ldb); + } + } + status = sec_access_check_ds(sd, token, + access_mask, + &access_granted, + root, + sid); + if (!NT_STATUS_IS_OK(status)) { + dsdb_acl_debug(sd, + token, + dn, + true, + 10); + ldb_asprintf_errstring(ldb, + "dsdb_access: Access check failed on %s", + ldb_dn_get_linearized(dn)); + TALLOC_FREE(sd); + TALLOC_FREE(sid); + return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS; + } + return LDB_SUCCESS; +} + +/* performs an access check from outside the module stack + * given the dn of the object to be checked, the required access + * guid is either the guid of the extended right, or NULL + */ + +int dsdb_check_access_on_dn(struct ldb_context *ldb, + TALLOC_CTX *mem_ctx, + struct ldb_dn *dn, + struct security_token *token, + uint32_t access_mask, + const char *ext_right) +{ + int ret; + struct GUID guid; + struct ldb_result *acl_res; + static const char *acl_attrs[] = { + "nTSecurityDescriptor", + "objectSid", + NULL + }; + + if (ext_right != NULL) { + NTSTATUS status = GUID_from_string(ext_right, &guid); + if (!NT_STATUS_IS_OK(status)) { + return LDB_ERR_OPERATIONS_ERROR; + } + } + + /* + * We need AS_SYSTEM in order to get the nTSecurityDescriptor attribute. + * Also the result of this search not controlled by the client + * nor is the result exposed to the client. + */ + ret = dsdb_search_dn(ldb, mem_ctx, &acl_res, dn, acl_attrs, + DSDB_FLAG_AS_SYSTEM | DSDB_SEARCH_SHOW_RECYCLED); + if (ret != LDB_SUCCESS) { + DEBUG(10,("access_check: failed to find object %s\n", ldb_dn_get_linearized(dn))); + return ret; + } + + return dsdb_check_access_on_dn_internal(ldb, acl_res, + mem_ctx, + token, + dn, + access_mask, + ext_right ? &guid : NULL); +} + |