Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2585 insertions, 0 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/acl.c b/source4/dsdb/samdb/ldb_modules/acl.c
new file mode 100644
index 0000000..78a5ddf
--- /dev/null
+++ b/source4/dsdb/samdb/ldb_modules/acl.c
@@ -0,0 +1,2585 @@
+/*
+  ldb database library
+
+  Copyright (C) Simo Sorce 2006-2008
+  Copyright (C) Nadezhda Ivanova 2009
+  Copyright (C) Anatoliy Atanasov  2009
+
+  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: ldb
+ *
+ *  Component: ldb ACL module
+ *
+ *  Description: Module that performs authorisation access checks based on the
+ *               account's security context and the DACL of the object being polled.
+ *               Only DACL checks implemented at this point
+ *
+ *  Authors: Nadezhda Ivanova, Anatoliy Atanasov
+ */
+
+#include "includes.h"
+#include "ldb_module.h"
+#include "auth/auth.h"
+#include "libcli/security/security.h"
+#include "dsdb/samdb/samdb.h"
+#include "librpc/gen_ndr/ndr_security.h"
+#include "param/param.h"
+#include "dsdb/samdb/ldb_modules/util.h"
+#include "lib/util/tsort.h"
+#include "system/kerberos.h"
+#include "auth/kerberos/kerberos.h"
+
+#undef strcasecmp
+#undef strncasecmp
+
+struct acl_private {
+	bool acl_search;
+	const char **password_attrs;
+	void *cached_schema_ptr;
+	uint64_t cached_schema_metadata_usn;
+	uint64_t cached_schema_loaded_usn;
+	const char **confidential_attrs;
+};
+
+struct acl_context {
+	struct ldb_module *module;
+	struct ldb_request *req;
+	bool am_system;
+	bool am_administrator;
+	bool constructed_attrs;
+	bool allowedAttributes;
+	bool allowedAttributesEffective;
+	bool allowedChildClasses;
+	bool allowedChildClassesEffective;
+	bool sDRightsEffective;
+	struct dsdb_schema *schema;
+};
+
+static int acl_module_init(struct ldb_module *module)
+{
+	struct ldb_context *ldb;
+	struct acl_private *data;
+	int ret;
+
+	ldb = ldb_module_get_ctx(module);
+
+	data = talloc_zero(module, struct acl_private);
+	if (data == NULL) {
+		return ldb_oom(ldb);
+	}
+
+	data->acl_search = lpcfg_parm_bool(ldb_get_opaque(ldb, "loadparm"),
+					NULL, "acl", "search", true);
+	ldb_module_set_private(module, data);
+
+	ret = ldb_mod_register_control(module, LDB_CONTROL_SD_FLAGS_OID);
+	if (ret != LDB_SUCCESS) {
+		ldb_debug(ldb, LDB_DEBUG_ERROR,
+			  "acl_module_init: Unable to register control with rootdse!\n");
+		return ldb_operr(ldb);
+	}
+
+	return ldb_next_init(module);
+}
+
+static int acl_allowedAttributes(struct ldb_module *module,
+				 const struct dsdb_schema *schema,
+				 struct ldb_message *sd_msg,
+				 struct ldb_message *msg,
+				 struct acl_context *ac)
+{
+	struct ldb_message_element *oc_el;
+	struct ldb_context *ldb = ldb_module_get_ctx(module);
+	TALLOC_CTX *mem_ctx;
+	const char **attr_list;
+	int i, ret;
+	const struct dsdb_class *objectclass;
+
+	/* If we don't have a schema yet, we can't do anything... */
+	if (schema == NULL) {
+		ldb_asprintf_errstring(ldb, "cannot add allowedAttributes to %s because no schema is loaded", ldb_dn_get_linearized(msg->dn));
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	/* Must remove any existing attribute */
+	if (ac->allowedAttributes) {
+		ldb_msg_remove_attr(msg, "allowedAttributes");
+	}
+
+	mem_ctx = talloc_new(msg);
+	if (!mem_ctx) {
+		return ldb_oom(ldb);
+	}
+
+	oc_el = ldb_msg_find_element(sd_msg, "objectClass");
+	attr_list = dsdb_full_attribute_list(mem_ctx, schema, oc_el, DSDB_SCHEMA_ALL);
+	if (!attr_list) {
+		ldb_asprintf_errstring(ldb, "acl: Failed to get list of attributes");
+		talloc_free(mem_ctx);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	/*
+	 * Get the top-most structural object class for the ACL check
+	 */
+	objectclass = dsdb_get_last_structural_class(ac->schema,
+						     oc_el);
+	if (objectclass == NULL) {
+		ldb_asprintf_errstring(ldb, "acl_read: Failed to find a structural class for %s",
+				       ldb_dn_get_linearized(sd_msg->dn));
+		talloc_free(mem_ctx);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	if (ac->allowedAttributes) {
+		for (i=0; attr_list && attr_list[i]; i++) {
+			ldb_msg_add_string(msg, "allowedAttributes", attr_list[i]);
+		}
+	}
+	if (ac->allowedAttributesEffective) {
+		struct security_descriptor *sd;
+		struct dom_sid *sid = NULL;
+		struct ldb_control *as_system = ldb_request_get_control(ac->req,
+									LDB_CONTROL_AS_SYSTEM_OID);
+
+		if (as_system != NULL) {
+			as_system->critical = 0;
+		}
+
+		ldb_msg_remove_attr(msg, "allowedAttributesEffective");
+		if (ac->am_system || as_system) {
+			for (i=0; attr_list && attr_list[i]; i++) {
+				ldb_msg_add_string(msg, "allowedAttributesEffective", attr_list[i]);
+			}
+			return LDB_SUCCESS;
+		}
+
+		ret = dsdb_get_sd_from_ldb_message(ldb_module_get_ctx(module), mem_ctx, sd_msg, &sd);
+
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+
+		sid = samdb_result_dom_sid(mem_ctx, sd_msg, "objectSid");
+		for (i=0; attr_list && attr_list[i]; i++) {
+			const struct dsdb_attribute *attr = dsdb_attribute_by_lDAPDisplayName(schema,
+											attr_list[i]);
+			if (!attr) {
+				return ldb_operr(ldb);
+			}
+			/* remove constructed attributes */
+			if (attr->systemFlags & DS_FLAG_ATTR_IS_CONSTRUCTED
+			    || attr->systemOnly
+			    || (attr->linkID != 0 && attr->linkID % 2 != 0 )) {
+				continue;
+			}
+			ret = acl_check_access_on_attribute(module,
+							    msg,
+							    sd,
+							    sid,
+							    SEC_ADS_WRITE_PROP,
+							    attr,
+							    objectclass);
+			if (ret == LDB_SUCCESS) {
+				ldb_msg_add_string(msg, "allowedAttributesEffective", attr_list[i]);
+			}
+		}
+	}
+	return LDB_SUCCESS;
+}
+
+static int acl_childClasses(struct ldb_module *module,
+			    const struct dsdb_schema *schema,
+			    struct ldb_message *sd_msg,
+			    struct ldb_message *msg,
+			    const char *attrName)
+{
+	struct ldb_message_element *oc_el;
+	struct ldb_message_element *allowedClasses;
+	const struct dsdb_class *sclass;
+	unsigned int i, j;
+	int ret;
+
+	/* If we don't have a schema yet, we can't do anything... */
+	if (schema == NULL) {
+		ldb_asprintf_errstring(ldb_module_get_ctx(module), "cannot add childClassesEffective to %s because no schema is loaded", ldb_dn_get_linearized(msg->dn));
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	/* Must remove any existing attribute, or else confusion reins */
+	ldb_msg_remove_attr(msg, attrName);
+	ret = ldb_msg_add_empty(msg, attrName, 0, &allowedClasses);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	oc_el = ldb_msg_find_element(sd_msg, "objectClass");
+
+	for (i=0; oc_el && i < oc_el->num_values; i++) {
+		sclass = dsdb_class_by_lDAPDisplayName_ldb_val(schema, &oc_el->values[i]);
+		if (!sclass) {
+			/* We don't know this class?  what is going on? */
+			continue;
+		}
+
+		for (j=0; sclass->possibleInferiors && sclass->possibleInferiors[j]; j++) {
+			ldb_msg_add_string(msg, attrName, sclass->possibleInferiors[j]);
+		}
+	}
+	if (allowedClasses->num_values > 1) {
+		TYPESAFE_QSORT(allowedClasses->values, allowedClasses->num_values, data_blob_cmp);
+		for (i=1 ; i < allowedClasses->num_values; i++) {
+			struct ldb_val *val1 = &allowedClasses->values[i-1];
+			struct ldb_val *val2 = &allowedClasses->values[i];
+			if (data_blob_cmp(val1, val2) == 0) {
+				memmove(val1, val2, (allowedClasses->num_values - i) * sizeof(struct ldb_val));
+				allowedClasses->num_values--;
+				i--;
+			}
+		}
+	}
+
+	return LDB_SUCCESS;
+}
+
+static int acl_childClassesEffective(struct ldb_module *module,
+				     const struct dsdb_schema *schema,
+				     struct ldb_message *sd_msg,
+				     struct ldb_message *msg,
+				     struct acl_context *ac)
+{
+	struct ldb_message_element *oc_el;
+	struct ldb_message_element *allowedClasses = NULL;
+	const struct dsdb_class *sclass;
+	struct security_descriptor *sd;
+	struct ldb_control *as_system = ldb_request_get_control(ac->req,
+								LDB_CONTROL_AS_SYSTEM_OID);
+	struct dom_sid *sid = NULL;
+	unsigned int i, j;
+	int ret;
+
+	if (as_system != NULL) {
+		as_system->critical = 0;
+	}
+
+	if (ac->am_system || as_system) {
+		return acl_childClasses(module, schema, sd_msg, msg, "allowedChildClassesEffective");
+	}
+
+	/* If we don't have a schema yet, we can't do anything... */
+	if (schema == NULL) {
+		ldb_asprintf_errstring(ldb_module_get_ctx(module), "cannot add allowedChildClassesEffective to %s because no schema is loaded", ldb_dn_get_linearized(msg->dn));
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	/* Must remove any existing attribute, or else confusion reins */
+	ldb_msg_remove_attr(msg, "allowedChildClassesEffective");
+
+	oc_el = ldb_msg_find_element(sd_msg, "objectClass");
+	ret = dsdb_get_sd_from_ldb_message(ldb_module_get_ctx(module), msg, sd_msg, &sd);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	sid = samdb_result_dom_sid(msg, sd_msg, "objectSid");
+	for (i=0; oc_el && i < oc_el->num_values; i++) {
+		sclass = dsdb_class_by_lDAPDisplayName_ldb_val(schema, &oc_el->values[i]);
+		if (!sclass) {
+			/* We don't know this class?  what is going on? */
+			continue;
+		}
+
+		for (j=0; sclass->possibleInferiors && sclass->possibleInferiors[j]; j++) {
+			const struct dsdb_class *sc;
+
+			sc = dsdb_class_by_lDAPDisplayName(schema,
+							   sclass->possibleInferiors[j]);
+			if (!sc) {
+				/* We don't know this class?  what is going on? */
+				continue;
+			}
+
+			ret = acl_check_access_on_objectclass(module, ac,
+							      sd, sid,
+							      SEC_ADS_CREATE_CHILD,
+							      sc);
+			if (ret == LDB_SUCCESS) {
+				ldb_msg_add_string(msg, "allowedChildClassesEffective",
+						   sclass->possibleInferiors[j]);
+			}
+		}
+	}
+	allowedClasses = ldb_msg_find_element(msg, "allowedChildClassesEffective");
+	if (!allowedClasses) {
+		return LDB_SUCCESS;
+	}
+
+	if (allowedClasses->num_values > 1) {
+		TYPESAFE_QSORT(allowedClasses->values, allowedClasses->num_values, data_blob_cmp);
+		for (i=1 ; i < allowedClasses->num_values; i++) {
+			struct ldb_val *val1 = &allowedClasses->values[i-1];
+			struct ldb_val *val2 = &allowedClasses->values[i];
+			if (data_blob_cmp(val1, val2) == 0) {
+				memmove(val1, val2, (allowedClasses->num_values - i) * sizeof( struct ldb_val));
+				allowedClasses->num_values--;
+				i--;
+			}
+		}
+	}
+	return LDB_SUCCESS;
+}
+
+static int acl_sDRightsEffective(struct ldb_module *module,
+				 struct ldb_message *sd_msg,
+				 struct ldb_message *msg,
+				 struct acl_context *ac)
+{
+	struct ldb_context *ldb = ldb_module_get_ctx(module);
+	struct ldb_message_element *rightsEffective;
+	int ret;
+	struct security_descriptor *sd;
+	struct ldb_control *as_system = ldb_request_get_control(ac->req,
+								LDB_CONTROL_AS_SYSTEM_OID);
+	struct dom_sid *sid = NULL;
+	uint32_t flags = 0;
+
+	if (as_system != NULL) {
+		as_system->critical = 0;
+	}
+
+	/* Must remove any existing attribute, or else confusion reins */
+	ldb_msg_remove_attr(msg, "sDRightsEffective");
+	ret = ldb_msg_add_empty(msg, "sDRightsEffective", 0, &rightsEffective);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	if (ac->am_system || as_system) {
+		flags = SECINFO_OWNER | SECINFO_GROUP |  SECINFO_SACL |  SECINFO_DACL;
+	} else {
+		const struct dsdb_class *objectclass;
+		const struct dsdb_attribute *attr;
+
+		objectclass = dsdb_get_structural_oc_from_msg(ac->schema, sd_msg);
+		if (objectclass == NULL) {
+			return ldb_operr(ldb);
+		}
+
+		attr = dsdb_attribute_by_lDAPDisplayName(ac->schema,
+							 "nTSecurityDescriptor");
+		if (attr == NULL) {
+			return ldb_operr(ldb);
+		}
+
+		/* Get the security descriptor from the message */
+		ret = dsdb_get_sd_from_ldb_message(ldb, msg, sd_msg, &sd);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+		sid = samdb_result_dom_sid(msg, sd_msg, "objectSid");
+		ret = acl_check_access_on_attribute(module,
+						    msg,
+						    sd,
+						    sid,
+						    SEC_STD_WRITE_OWNER,
+						    attr,
+						    objectclass);
+		if (ret == LDB_SUCCESS) {
+			flags |= SECINFO_OWNER | SECINFO_GROUP;
+		}
+		ret = acl_check_access_on_attribute(module,
+						    msg,
+						    sd,
+						    sid,
+						    SEC_STD_WRITE_DAC,
+						    attr,
+						    objectclass);
+		if (ret == LDB_SUCCESS) {
+			flags |= SECINFO_DACL;
+		}
+		ret = acl_check_access_on_attribute(module,
+						    msg,
+						    sd,
+						    sid,
+						    SEC_FLAG_SYSTEM_SECURITY,
+						    attr,
+						    objectclass);
+		if (ret == LDB_SUCCESS) {
+			flags |= SECINFO_SACL;
+		}
+	}
+	return samdb_msg_add_uint(ldb_module_get_ctx(module), msg, msg,
+				  "sDRightsEffective", flags);
+}
+
+static int acl_validate_spn_value(TALLOC_CTX *mem_ctx,
+				  struct ldb_context *ldb,
+				  const struct ldb_val *spn_value,
+				  uint32_t userAccountControl,
+				  const struct ldb_val *samAccountName,
+				  const struct ldb_val *dnsHostName,
+				  const char *netbios_name,
+				  const char *ntds_guid)
+{
+	int ret, princ_size;
+	krb5_context krb_ctx;
+	krb5_error_code kerr;
+	krb5_principal principal;
+	char *instanceName;
+	char *serviceType;
+	char *serviceName;
+	const char *spn_value_str = NULL;
+	size_t account_name_len;
+	const char *forest_name = samdb_forest_name(ldb, mem_ctx);
+	const char *base_domain = samdb_default_domain_name(ldb, mem_ctx);
+	struct loadparm_context *lp_ctx = talloc_get_type(ldb_get_opaque(ldb, "loadparm"),
+							  struct loadparm_context);
+	bool is_dc = (userAccountControl & UF_SERVER_TRUST_ACCOUNT) ||
+		(userAccountControl & UF_PARTIAL_SECRETS_ACCOUNT);
+
+	spn_value_str = talloc_strndup(mem_ctx,
+				       (const char *)spn_value->data,
+				       spn_value->length);
+	if (spn_value_str == NULL) {
+		return ldb_oom(ldb);
+	}
+
+	if (spn_value->length == samAccountName->length &&
+	    strncasecmp((const char *)spn_value->data,
+			(const char *)samAccountName->data,
+			spn_value->length) == 0)
+	{
+		/* MacOS X sets this value, and setting an SPN of your
+		 * own samAccountName is both pointless and safe */
+		return LDB_SUCCESS;
+	}
+
+	kerr = smb_krb5_init_context_basic(mem_ctx,
+					   lp_ctx,
+					   &krb_ctx);
+	if (kerr != 0) {
+		return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
+				 "Could not initialize kerberos context.");
+	}
+
+	ret = krb5_parse_name(krb_ctx, spn_value_str, &principal);
+	if (ret) {
+		krb5_free_context(krb_ctx);
+		return LDB_ERR_CONSTRAINT_VIOLATION;
+	}
+
+	princ_size = krb5_princ_size(krb_ctx, principal);
+	if (princ_size < 2) {
+		DBG_WARNING("princ_size=%d\n", princ_size);
+		goto fail;
+	}
+
+	instanceName = smb_krb5_principal_get_comp_string(mem_ctx, krb_ctx,
+							  principal, 1);
+	serviceType = smb_krb5_principal_get_comp_string(mem_ctx, krb_ctx,
+							 principal, 0);
+	if (krb5_princ_size(krb_ctx, principal) == 3) {
+		serviceName = smb_krb5_principal_get_comp_string(mem_ctx, krb_ctx,
+								 principal, 2);
+	} else {
+		serviceName = NULL;
+	}
+
+	if (serviceName) {
+		if (!is_dc) {
+			DBG_WARNING("is_dc=false, serviceName=%s,"
+				    "serviceType=%s\n", serviceName,
+				  serviceType);
+			goto fail;
+		}
+		if (strcasecmp(serviceType, "ldap") == 0) {
+			if (strcasecmp(serviceName, netbios_name) != 0 &&
+			    strcasecmp(serviceName, forest_name) != 0) {
+				DBG_WARNING("serviceName=%s\n", serviceName);
+				goto fail;
+			}
+
+		} else if (strcasecmp(serviceType, "gc") == 0) {
+			if (strcasecmp(serviceName, forest_name) != 0) {
+				DBG_WARNING("serviceName=%s\n", serviceName);
+				goto fail;
+			}
+		} else {
+			if (strcasecmp(serviceName, base_domain) != 0 &&
+			    strcasecmp(serviceName, netbios_name) != 0) {
+				DBG_WARNING("serviceType=%s, "
+					    "serviceName=%s\n",
+					    serviceType, serviceName);
+				goto fail;
+			}
+		}
+	}
+
+	account_name_len = samAccountName->length;
+	if (account_name_len &&
+	    samAccountName->data[account_name_len - 1] == '$')
+	{
+		/* Account for the '$' character. */
+		--account_name_len;
+	}
+
+	/* instanceName can be samAccountName without $ or dnsHostName
+	 * or "ntds_guid._msdcs.forest_domain for DC objects */
+	if (strlen(instanceName) == account_name_len
+	    && strncasecmp(instanceName,
+			   (const char *)samAccountName->data,
+			   account_name_len) == 0)
+	{
+		goto success;
+	}
+	if ((dnsHostName != NULL) &&
+	    strlen(instanceName) == dnsHostName->length &&
+	    (strncasecmp(instanceName,
+			 (const char *)dnsHostName->data,
+			 dnsHostName->length) == 0))
+	{
+		goto success;
+	}
+	if (is_dc) {
+		const char *guid_str;
+		guid_str = talloc_asprintf(mem_ctx,"%s._msdcs.%s",
+					   ntds_guid,
+					   forest_name);
+		if (strcasecmp(instanceName, guid_str) == 0) {
+			goto success;
+		}
+	}
+
+fail:
+	krb5_free_principal(krb_ctx, principal);
+	krb5_free_context(krb_ctx);
+	ldb_debug_set(ldb, LDB_DEBUG_WARNING,
+		      "acl: spn validation failed for "
+		      "spn[%.*s] uac[0x%x] account[%.*s] hostname[%.*s] "
+		      "nbname[%s] ntds[%s] forest[%s] domain[%s]\n",
+		      (int)spn_value->length, spn_value->data,
+		      (unsigned)userAccountControl,
+		      (int)samAccountName->length, samAccountName->data,
+		      dnsHostName != NULL ? (int)dnsHostName->length : 0,
+		      dnsHostName != NULL ? (const char *)dnsHostName->data : "",
+		      netbios_name, ntds_guid,
+		      forest_name, base_domain);
+	return LDB_ERR_CONSTRAINT_VIOLATION;
+
+success:
+	krb5_free_principal(krb_ctx, principal);
+	krb5_free_context(krb_ctx);
+	return LDB_SUCCESS;
+}
+
+/*
+ * Passing in 'el' is critical, we want to check all the values.
+ *
+ */
+static int acl_check_spn(TALLOC_CTX *mem_ctx,
+			 struct ldb_module *module,
+			 struct ldb_request *req,
+			 const struct ldb_message_element *el,
+			 struct security_descriptor *sd,
+			 struct dom_sid *sid,
+			 const struct dsdb_attribute *attr,
+			 const struct dsdb_class *objectclass,
+			 const struct ldb_control *implicit_validated_write_control)
+{
+	int ret;
+	unsigned int i;
+	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
+	struct ldb_context *ldb = ldb_module_get_ctx(module);
+	struct ldb_result *acl_res;
+	struct ldb_result *netbios_res;
+	struct ldb_dn *partitions_dn = samdb_partitions_dn(ldb, tmp_ctx);
+	uint32_t userAccountControl;
+	const char *netbios_name;
+	const struct ldb_val *dns_host_name_val = NULL;
+	const struct ldb_val *sam_account_name_val = NULL;
+	struct GUID ntds;
+	char *ntds_guid = NULL;
+
+	static const char *acl_attrs[] = {
+		"samAccountName",
+		"dnsHostName",
+		"userAccountControl",
+		NULL
+	};
+	static const char *netbios_attrs[] = {
+		"nETBIOSName",
+		NULL
+	};
+
+	if (implicit_validated_write_control != NULL) {
+		/*
+		 * The validated write control dispenses with ACL
+		 * checks. We act as if we have an implicit Self Write
+		 * privilege, but, assuming we don't have Write
+		 * Property, still proceed with further validation
+		 * checks.
+		 */
+	} else {
+		/* if we have wp, we can do whatever we like */
+		if (acl_check_access_on_attribute(module,
+						  tmp_ctx,
+						  sd,
+						  sid,
+						  SEC_ADS_WRITE_PROP,
+						  attr, objectclass) == LDB_SUCCESS) {
+			talloc_free(tmp_ctx);
+			return LDB_SUCCESS;
+		}
+
+		ret = acl_check_extended_right(tmp_ctx,
+					       module,
+					       req,
+					       objectclass,
+					       sd,
+					       acl_user_token(module),
+					       GUID_DRS_VALIDATE_SPN,
+					       SEC_ADS_SELF_WRITE,
+					       sid);
+
+		if (ret != LDB_SUCCESS) {
+			dsdb_acl_debug(sd, acl_user_token(module),
+				       req->op.mod.message->dn,
+				       true,
+				       10);
+			talloc_free(tmp_ctx);
+			return ret;
+		}
+	}
+
+	/*
+	 * If we have "validated write spn", allow delete of any
+	 * existing value (this keeps constrained delete to the same
+	 * rules as unconstrained)
+	 */
+	if (req->operation == LDB_MODIFY) {
+		/*
+		 * If not add or replace (eg delete),
+		 * return success
+		 */
+		if (LDB_FLAG_MOD_TYPE(el->flags) != LDB_FLAG_MOD_ADD &&
+		    LDB_FLAG_MOD_TYPE(el->flags) != LDB_FLAG_MOD_REPLACE)
+		{
+			talloc_free(tmp_ctx);
+			return LDB_SUCCESS;
+		}
+	}
+
+	ret = dsdb_module_search_dn(module, tmp_ctx,
+				    &acl_res, req->op.mod.message->dn,
+				    acl_attrs,
+				    DSDB_FLAG_NEXT_MODULE |
+				    DSDB_FLAG_AS_SYSTEM |
+				    DSDB_SEARCH_SHOW_RECYCLED,
+				    req);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	dns_host_name_val = ldb_msg_find_ldb_val(acl_res->msgs[0], "dNSHostName");
+
+	ret = dsdb_msg_get_single_value(req->op.mod.message,
+					"dNSHostName",
+					dns_host_name_val,
+					&dns_host_name_val,
+					req->operation);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	userAccountControl = ldb_msg_find_attr_as_uint(acl_res->msgs[0], "userAccountControl", 0);
+
+	sam_account_name_val = ldb_msg_find_ldb_val(acl_res->msgs[0], "sAMAccountName");
+
+	ret = dsdb_msg_get_single_value(req->op.mod.message,
+					"sAMAccountName",
+					sam_account_name_val,
+					&sam_account_name_val,
+					req->operation);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	ret = dsdb_module_search(module, tmp_ctx,
+				 &netbios_res, partitions_dn,
+				 LDB_SCOPE_ONELEVEL,
+				 netbios_attrs,
+				 DSDB_FLAG_NEXT_MODULE |
+				 DSDB_FLAG_AS_SYSTEM,
+				 req,
+				 "(ncName=%s)",
+				 ldb_dn_get_linearized(ldb_get_default_basedn(ldb)));
+
+	netbios_name = ldb_msg_find_attr_as_string(netbios_res->msgs[0], "nETBIOSName", NULL);
+
+	/* NTDSDSA objectGuid of object we are checking SPN for */
+	if (userAccountControl & (UF_SERVER_TRUST_ACCOUNT | UF_PARTIAL_SECRETS_ACCOUNT)) {
+		ret = dsdb_module_find_ntdsguid_for_computer(module, tmp_ctx,
+							     req->op.mod.message->dn, &ntds, req);
+		if (ret != LDB_SUCCESS) {
+			ldb_asprintf_errstring(ldb, "Failed to find NTDSDSA objectGuid for %s: %s",
+					       ldb_dn_get_linearized(req->op.mod.message->dn),
+					       ldb_strerror(ret));
+			talloc_free(tmp_ctx);
+			return LDB_ERR_OPERATIONS_ERROR;
+		}
+		ntds_guid = GUID_string(tmp_ctx, &ntds);
+	}
+
+	for (i=0; i < el->num_values; i++) {
+		ret = acl_validate_spn_value(tmp_ctx,
+					     ldb,
+					     &el->values[i],
+					     userAccountControl,
+					     sam_account_name_val,
+					     dns_host_name_val,
+					     netbios_name,
+					     ntds_guid);
+		if (ret != LDB_SUCCESS) {
+			talloc_free(tmp_ctx);
+			return ret;
+		}
+	}
+	talloc_free(tmp_ctx);
+	return LDB_SUCCESS;
+}
+
+static int acl_check_dns_host_name(TALLOC_CTX *mem_ctx,
+				   struct ldb_module *module,
+				   struct ldb_request *req,
+				   const struct ldb_message_element *el,
+				   struct security_descriptor *sd,
+				   struct dom_sid *sid,
+				   const struct dsdb_attribute *attr,
+				   const struct dsdb_class *objectclass,
+				   const struct ldb_control *implicit_validated_write_control)
+{
+	int ret;
+	unsigned i;
+	TALLOC_CTX *tmp_ctx = NULL;
+	struct ldb_context *ldb = ldb_module_get_ctx(module);
+	const struct dsdb_schema *schema = NULL;
+	const struct ldb_message_element *allowed_suffixes = NULL;
+	struct ldb_result *nc_res = NULL;
+	struct ldb_dn *nc_root = NULL;
+	const char *nc_dns_name = NULL;
+	const char *dnsHostName_str = NULL;
+	size_t dns_host_name_len;
+	size_t account_name_len;
+	const struct ldb_message *msg = NULL;
+	const struct ldb_message *search_res = NULL;
+	const struct ldb_val *samAccountName = NULL;
+	const struct ldb_val *dnsHostName = NULL;
+	const struct dsdb_class *computer_objectclass = NULL;
+	bool is_subclass;
+
+	static const char *nc_attrs[] = {
+		"msDS-AllowedDNSSuffixes",
+		NULL
+	};
+
+	tmp_ctx = talloc_new(mem_ctx);
+	if (tmp_ctx == NULL) {
+		return ldb_oom(ldb);
+	}
+
+	if (implicit_validated_write_control != NULL) {
+		/*
+		 * The validated write control dispenses with ACL
+		 * checks. We act as if we have an implicit Self Write
+		 * privilege, but, assuming we don't have Write
+		 * Property, still proceed with further validation
+		 * checks.
+		 */
+	} else {
+		/* if we have wp, we can do whatever we like */
+		ret = acl_check_access_on_attribute(module,
+						    tmp_ctx,
+						    sd,
+						    sid,
+						    SEC_ADS_WRITE_PROP,
+						    attr, objectclass);
+		if (ret == LDB_SUCCESS) {
+			talloc_free(tmp_ctx);
+			return LDB_SUCCESS;
+		}
+
+		ret = acl_check_extended_right(tmp_ctx,
+					       module,
+					       req,
+					       objectclass,
+					       sd,
+					       acl_user_token(module),
+					       GUID_DRS_DNS_HOST_NAME,
+					       SEC_ADS_SELF_WRITE,
+					       sid);
+
+		if (ret != LDB_SUCCESS) {
+			dsdb_acl_debug(sd, acl_user_token(module),
+				       req->op.mod.message->dn,
+				       true,
+				       10);
+			talloc_free(tmp_ctx);
+			return ret;
+		}
+	}
+
+	/*
+	 * If we have "validated write dnshostname", allow delete of
+	 * any existing value (this keeps constrained delete to the
+	 * same rules as unconstrained)
+	 */
+	if (req->operation == LDB_MODIFY) {
+		struct ldb_result *acl_res = NULL;
+
+		static const char *acl_attrs[] = {
+			"sAMAccountName",
+			NULL
+		};
+
+		msg = req->op.mod.message;
+
+		/*
+		 * If not add or replace (eg delete),
+		 * return success
+		 */
+		if ((el->flags
+		     & (LDB_FLAG_MOD_ADD|LDB_FLAG_MOD_REPLACE)) == 0)
+		{
+			talloc_free(tmp_ctx);
+			return LDB_SUCCESS;
+		}
+
+		ret = dsdb_module_search_dn(module, tmp_ctx,
+					    &acl_res, msg->dn,
+					    acl_attrs,
+					    DSDB_FLAG_NEXT_MODULE |
+					    DSDB_FLAG_AS_SYSTEM |
+					    DSDB_SEARCH_SHOW_RECYCLED,
+					    req);
+		if (ret != LDB_SUCCESS) {
+			talloc_free(tmp_ctx);
+			return ret;
+		}
+
+		search_res = acl_res->msgs[0];
+	} else if (req->operation == LDB_ADD) {
+		msg = req->op.add.message;
+		search_res = msg;
+	} else {
+		talloc_free(tmp_ctx);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+        /* Check if the account has objectclass 'computer' or 'server'. */
+
+	schema = dsdb_get_schema(ldb, req);
+	if (schema == NULL) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+
+	computer_objectclass = dsdb_class_by_lDAPDisplayName(schema, "computer");
+	if (computer_objectclass == NULL) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+
+	is_subclass = dsdb_is_subclass_of(schema, objectclass, computer_objectclass);
+	if (!is_subclass) {
+		/* The account is not a computer -- check if it's a server. */
+
+		const struct dsdb_class *server_objectclass = NULL;
+
+		server_objectclass = dsdb_class_by_lDAPDisplayName(schema, "server");
+		if (server_objectclass == NULL) {
+			talloc_free(tmp_ctx);
+			return ldb_operr(ldb);
+		}
+
+		is_subclass = dsdb_is_subclass_of(schema, objectclass, server_objectclass);
+		if (!is_subclass) {
+			/* Not a computer or server, so no need to validate. */
+			talloc_free(tmp_ctx);
+			return LDB_SUCCESS;
+		}
+	}
+
+	samAccountName = ldb_msg_find_ldb_val(search_res, "sAMAccountName");
+
+	ret = dsdb_msg_get_single_value(msg,
+					"sAMAccountName",
+					samAccountName,
+					&samAccountName,
+					req->operation);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	account_name_len = samAccountName->length;
+	if (account_name_len && samAccountName->data[account_name_len - 1] == '$') {
+		/* Account for the '$' character. */
+		--account_name_len;
+	}
+
+	/* Check for add or replace requests with no value. */
+	if (el->num_values == 0) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+	dnsHostName = &el->values[0];
+
+	dnsHostName_str = (const char *)dnsHostName->data;
+	dns_host_name_len = dnsHostName->length;
+
+	/* Check that sAMAccountName matches the new dNSHostName. */
+
+	if (dns_host_name_len < account_name_len) {
+		goto fail;
+	}
+	if (strncasecmp(dnsHostName_str,
+			(const char *)samAccountName->data,
+			account_name_len) != 0)
+	{
+		goto fail;
+	}
+
+	dnsHostName_str += account_name_len;
+	dns_host_name_len -= account_name_len;
+
+	/* Check the '.' character */
+
+	if (dns_host_name_len == 0 || *dnsHostName_str != '.') {
+		goto fail;
+	}
+
+	++dnsHostName_str;
+	--dns_host_name_len;
+
+	/* Now we check the suffix. */
+
+	ret = dsdb_find_nc_root(ldb,
+				tmp_ctx,
+				search_res->dn,
+				&nc_root);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	nc_dns_name = samdb_dn_to_dns_domain(tmp_ctx, nc_root);
+	if (nc_dns_name == NULL) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+
+	if (strlen(nc_dns_name) == dns_host_name_len &&
+	    strncasecmp(dnsHostName_str,
+			nc_dns_name,
+			dns_host_name_len) == 0)
+	{
+		/* It matches -- success. */
+		talloc_free(tmp_ctx);
+		return LDB_SUCCESS;
+	}
+
+	/* We didn't get a match, so now try msDS-AllowedDNSSuffixes. */
+
+	ret = dsdb_module_search_dn(module, tmp_ctx,
+				    &nc_res, nc_root,
+				    nc_attrs,
+				    DSDB_FLAG_NEXT_MODULE |
+				    DSDB_FLAG_AS_SYSTEM |
+				    DSDB_SEARCH_SHOW_RECYCLED,
+				    req);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	allowed_suffixes = ldb_msg_find_element(nc_res->msgs[0],
+						"msDS-AllowedDNSSuffixes");
+	if (allowed_suffixes == NULL) {
+		goto fail;
+	}
+
+	for (i = 0; i < allowed_suffixes->num_values; ++i) {
+		const struct ldb_val *suffix = &allowed_suffixes->values[i];
+
+		if (suffix->length == dns_host_name_len &&
+		    strncasecmp(dnsHostName_str,
+				(const char *)suffix->data,
+				dns_host_name_len) == 0)
+		{
+			/* It matches -- success. */
+			talloc_free(tmp_ctx);
+			return LDB_SUCCESS;
+		}
+	}
+
+fail:
+	ldb_debug_set(ldb, LDB_DEBUG_WARNING,
+		      "acl: hostname validation failed for "
+		      "hostname[%.*s] account[%.*s]\n",
+		      (int)dnsHostName->length, dnsHostName->data,
+		      (int)samAccountName->length, samAccountName->data);
+	talloc_free(tmp_ctx);
+	return LDB_ERR_CONSTRAINT_VIOLATION;
+}
+
+static int acl_add(struct ldb_module *module, struct ldb_request *req)
+{
+	int ret;
+	struct ldb_dn *parent;
+	struct ldb_context *ldb;
+	const struct dsdb_schema *schema;
+	const struct dsdb_class *objectclass;
+	struct ldb_control *as_system;
+	struct ldb_message_element *el;
+	unsigned int instanceType = 0;
+
+	if (ldb_dn_is_special(req->op.add.message->dn)) {
+		return ldb_next_request(module, req);
+	}
+
+	as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
+	if (as_system != NULL) {
+		as_system->critical = 0;
+	}
+
+	if (dsdb_module_am_system(module) || as_system) {
+		return ldb_next_request(module, req);
+	}
+
+	ldb = ldb_module_get_ctx(module);
+
+	parent = ldb_dn_get_parent(req, req->op.add.message->dn);
+	if (parent == NULL) {
+		return ldb_oom(ldb);
+	}
+
+	schema = dsdb_get_schema(ldb, req);
+	if (!schema) {
+		return ldb_operr(ldb);
+	}
+
+	objectclass = dsdb_get_structural_oc_from_msg(schema, req->op.add.message);
+	if (!objectclass) {
+		ldb_asprintf_errstring(ldb_module_get_ctx(module),
+				       "acl: unable to find or validate structural objectClass on %s\n",
+				       ldb_dn_get_linearized(req->op.add.message->dn));
+		return ldb_module_done(req, NULL, NULL, LDB_ERR_OPERATIONS_ERROR);
+	}
+
+	el = ldb_msg_find_element(req->op.add.message, "instanceType");
+	if ((el != NULL) && (el->num_values != 1)) {
+		ldb_set_errstring(ldb, "acl: the 'instanceType' attribute is single-valued!");
+		return LDB_ERR_UNWILLING_TO_PERFORM;
+	}
+
+	instanceType = ldb_msg_find_attr_as_uint(req->op.add.message,
+						 "instanceType", 0);
+	if (instanceType & INSTANCE_TYPE_IS_NC_HEAD) {
+		static const char *no_attrs[] = { NULL };
+		struct ldb_result *partition_res;
+		struct ldb_dn *partitions_dn;
+
+		partitions_dn = samdb_partitions_dn(ldb, req);
+		if (!partitions_dn) {
+			ldb_set_errstring(ldb, "acl: CN=partitions dn could not be generated!");
+			return LDB_ERR_UNWILLING_TO_PERFORM;
+		}
+
+		ret = dsdb_module_search(module, req, &partition_res,
+					 partitions_dn, LDB_SCOPE_ONELEVEL,
+					 no_attrs,
+					 DSDB_FLAG_NEXT_MODULE |
+					 DSDB_FLAG_AS_SYSTEM |
+					 DSDB_SEARCH_ONE_ONLY |
+					 DSDB_SEARCH_SHOW_RECYCLED,
+					 req,
+					 "(&(nCName=%s)(objectClass=crossRef))",
+					 ldb_dn_get_linearized(req->op.add.message->dn));
+
+		if (ret == LDB_SUCCESS) {
+			/* Check that we can write to the crossRef object MS-ADTS 3.1.1.5.2.8.2 */
+			ret = dsdb_module_check_access_on_dn(module, req, partition_res->msgs[0]->dn,
+							     SEC_ADS_WRITE_PROP,
+							     &objectclass->schemaIDGUID, req);
+			if (ret != LDB_SUCCESS) {
+				ldb_asprintf_errstring(ldb_module_get_ctx(module),
+						       "acl: ACL check failed on crossRef object %s: %s\n",
+						       ldb_dn_get_linearized(partition_res->msgs[0]->dn),
+						       ldb_errstring(ldb));
+				return ret;
+			}
+
+			/*
+			 * TODO: Remaining checks, like if we are
+			 * the naming master etc need to be handled
+			 * in the instanceType module
+			 */
+			return ldb_next_request(module, req);
+		}
+
+		/* Check that we can create a crossRef object MS-ADTS 3.1.1.5.2.8.2 */
+		ret = dsdb_module_check_access_on_dn(module, req, partitions_dn,
+						     SEC_ADS_CREATE_CHILD,
+						     &objectclass->schemaIDGUID, req);
+		if (ret == LDB_ERR_NO_SUCH_OBJECT &&
+		    ldb_request_get_control(req, LDB_CONTROL_RELAX_OID))
+		{
+			/* Allow provision bootstrap */
+			ret = LDB_SUCCESS;
+		}
+		if (ret != LDB_SUCCESS) {
+			ldb_asprintf_errstring(ldb_module_get_ctx(module),
+					       "acl: ACL check failed on CN=Partitions crossRef container %s: %s\n",
+					       ldb_dn_get_linearized(partitions_dn), ldb_errstring(ldb));
+			return ret;
+		}
+
+		/*
+		 * TODO: Remaining checks, like if we are the naming
+		 * master and adding the crossRef object need to be
+		 * handled in the instanceType module
+		 */
+		return ldb_next_request(module, req);
+	}
+
+	ret = dsdb_module_check_access_on_dn(module, req, parent,
+					     SEC_ADS_CREATE_CHILD,
+					     &objectclass->schemaIDGUID, req);
+	if (ret != LDB_SUCCESS) {
+		ldb_asprintf_errstring(ldb_module_get_ctx(module),
+				       "acl: unable to get access to %s\n",
+				       ldb_dn_get_linearized(req->op.add.message->dn));
+		return ret;
+	}
+	return ldb_next_request(module, req);
+}
+
+/* checks if modifications are allowed on "Member" attribute */
+static int acl_check_self_membership(TALLOC_CTX *mem_ctx,
+				     struct ldb_module *module,
+				     struct ldb_request *req,
+				     struct security_descriptor *sd,
+				     struct dom_sid *sid,
+				     const struct dsdb_attribute *attr,
+				     const struct dsdb_class *objectclass)
+{
+	int ret;
+	unsigned int i;
+	struct ldb_context *ldb = ldb_module_get_ctx(module);
+	struct ldb_dn *user_dn;
+	struct ldb_message_element *member_el;
+	const struct ldb_message *msg = NULL;
+
+	if (req->operation == LDB_MODIFY) {
+		msg = req->op.mod.message;
+	} else if (req->operation == LDB_ADD) {
+		msg = req->op.add.message;
+	} else {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	/* if we have wp, we can do whatever we like */
+	if (acl_check_access_on_attribute(module,
+					  mem_ctx,
+					  sd,
+					  sid,
+					  SEC_ADS_WRITE_PROP,
+					  attr, objectclass) == LDB_SUCCESS) {
+		return LDB_SUCCESS;
+	}
+	/* if we are adding/deleting ourselves, check for self membership */
+	ret = dsdb_find_dn_by_sid(ldb, mem_ctx,
+				  &acl_user_token(module)->sids[PRIMARY_USER_SID_INDEX],
+				  &user_dn);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	member_el = ldb_msg_find_element(msg, "member");
+	if (!member_el) {
+		return ldb_operr(ldb);
+	}
+	/* user can only remove oneself */
+	if (member_el->num_values == 0) {
+		return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
+	}
+	for (i = 0; i < member_el->num_values; i++) {
+		if (strcasecmp((const char *)member_el->values[i].data,
+			       ldb_dn_get_extended_linearized(mem_ctx, user_dn, 1)) != 0) {
+			return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
+		}
+	}
+	ret = acl_check_extended_right(mem_ctx,
+				       module,
+				       req,
+				       objectclass,
+				       sd,
+				       acl_user_token(module),
+				       GUID_DRS_SELF_MEMBERSHIP,
+				       SEC_ADS_SELF_WRITE,
+				       sid);
+	if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
+		dsdb_acl_debug(sd, acl_user_token(module),
+			       msg->dn,
+			       true,
+			       10);
+	}
+	return ret;
+}
+
+static int acl_check_password_rights(
+	TALLOC_CTX *mem_ctx,
+	struct ldb_module *module,
+	struct ldb_request *req,
+	struct security_descriptor *sd,
+	struct dom_sid *sid,
+	const struct dsdb_class *objectclass,
+	bool userPassword,
+	struct  dsdb_control_password_acl_validation **control_for_response)
+{
+	int ret = LDB_SUCCESS;
+	unsigned int del_attr_cnt = 0, add_attr_cnt = 0, rep_attr_cnt = 0;
+	unsigned int del_val_cnt = 0, add_val_cnt = 0, rep_val_cnt = 0;
+	struct ldb_message_element *el;
+	struct ldb_message *msg;
+	struct ldb_control *c = NULL;
+	const char *passwordAttrs[] = { "userPassword", "clearTextPassword",
+					"unicodePwd", NULL }, **l;
+	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
+	struct dsdb_control_password_acl_validation *pav = NULL;
+
+	if (tmp_ctx == NULL) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	pav = talloc_zero(req, struct dsdb_control_password_acl_validation);
+	if (pav == NULL) {
+		talloc_free(tmp_ctx);
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	/*
+	 * Set control_for_response to pav so it can be added to the response
+	 * and be passed up to the audit_log module which uses it to identify
+	 * password reset attempts.
+	 */
+	*control_for_response = pav;
+
+	c = ldb_request_get_control(req, DSDB_CONTROL_PASSWORD_CHANGE_OLD_PW_CHECKED_OID);
+	if (c != NULL) {
+		pav->pwd_reset = false;
+
+		/*
+		 * The "DSDB_CONTROL_PASSWORD_CHANGE_OLD_PW_CHECKED_OID" control means that we
+		 * have a user password change and not a set as the message
+		 * looks like. In it's value blob it contains the NT and/or LM
+		 * hash of the old password specified by the user.  This control
+		 * is used by the SAMR and "kpasswd" password change mechanisms.
+		 *
+		 * This control can't be used by real LDAP clients,
+		 * the only caller is samdb_set_password_internal(),
+		 * so we don't have to strict verification of the input.
+		 */
+		ret = acl_check_extended_right(tmp_ctx,
+					       module,
+					       req,
+					       objectclass,
+					       sd,
+					       acl_user_token(module),
+					       GUID_DRS_USER_CHANGE_PASSWORD,
+					       SEC_ADS_CONTROL_ACCESS,
+					       sid);
+		goto checked;
+	}
+
+	c = ldb_request_get_control(req, DSDB_CONTROL_PASSWORD_HASH_VALUES_OID);
+	if (c != NULL) {
+		pav->pwd_reset = true;
+
+		/*
+		 * The "DSDB_CONTROL_PASSWORD_HASH_VALUES_OID" control, without
+		 * "DSDB_CONTROL_PASSWORD_CHANGE_OLD_PW_CHECKED_OID" control means that we
+		 * have a force password set.
+		 * This control is used by the SAMR/NETLOGON/LSA password
+		 * reset mechanisms.
+		 *
+		 * This control can't be used by real LDAP clients,
+		 * the only caller is samdb_set_password_internal(),
+		 * so we don't have to strict verification of the input.
+		 */
+		ret = acl_check_extended_right(tmp_ctx,
+					       module,
+					       req,
+					       objectclass,
+					       sd,
+					       acl_user_token(module),
+					       GUID_DRS_FORCE_CHANGE_PASSWORD,
+					       SEC_ADS_CONTROL_ACCESS,
+					       sid);
+		goto checked;
+	}
+
+	el = ldb_msg_find_element(req->op.mod.message, "dBCSPwd");
+	if (el != NULL) {
+		/*
+		 * dBCSPwd is only allowed with a control.
+		 */
+		talloc_free(tmp_ctx);
+		return LDB_ERR_UNWILLING_TO_PERFORM;
+	}
+
+	msg = ldb_msg_copy_shallow(tmp_ctx, req->op.mod.message);
+	if (msg == NULL) {
+		return ldb_module_oom(module);
+	}
+	for (l = passwordAttrs; *l != NULL; l++) {
+		if ((!userPassword) && (ldb_attr_cmp(*l, "userPassword") == 0)) {
+			continue;
+		}
+
+		while ((el = ldb_msg_find_element(msg, *l)) != NULL) {
+			if (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_DELETE) {
+				++del_attr_cnt;
+				del_val_cnt += el->num_values;
+			}
+			if (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_ADD) {
+				++add_attr_cnt;
+				add_val_cnt += el->num_values;
+			}
+			if (LDB_FLAG_MOD_TYPE(el->flags) == LDB_FLAG_MOD_REPLACE) {
+				++rep_attr_cnt;
+				rep_val_cnt += el->num_values;
+			}
+			ldb_msg_remove_element(msg, el);
+		}
+	}
+
+	/* single deletes will be handled by the "password_hash" LDB module
+	 * later in the stack, so we let it though here */
+	if ((del_attr_cnt > 0) && (add_attr_cnt == 0) && (rep_attr_cnt == 0)) {
+		talloc_free(tmp_ctx);
+		return LDB_SUCCESS;
+	}
+
+
+	if (rep_attr_cnt > 0) {
+		pav->pwd_reset = true;
+
+		ret = acl_check_extended_right(tmp_ctx,
+					       module,
+					       req,
+					       objectclass,
+					       sd,
+					       acl_user_token(module),
+					       GUID_DRS_FORCE_CHANGE_PASSWORD,
+					       SEC_ADS_CONTROL_ACCESS,
+					       sid);
+		goto checked;
+	}
+
+	if (add_attr_cnt != del_attr_cnt) {
+		pav->pwd_reset = true;
+
+		ret = acl_check_extended_right(tmp_ctx,
+					       module,
+					       req,
+					       objectclass,
+					       sd,
+					       acl_user_token(module),
+					       GUID_DRS_FORCE_CHANGE_PASSWORD,
+					       SEC_ADS_CONTROL_ACCESS,
+					       sid);
+		goto checked;
+	}
+
+	if (add_val_cnt == 1 && del_val_cnt == 1) {
+		pav->pwd_reset = false;
+
+		ret = acl_check_extended_right(tmp_ctx,
+					       module,
+					       req,
+					       objectclass,
+					       sd,
+					       acl_user_token(module),
+					       GUID_DRS_USER_CHANGE_PASSWORD,
+					       SEC_ADS_CONTROL_ACCESS,
+					       sid);
+		/* Very strange, but we get constraint violation in this case */
+		if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
+			ret = LDB_ERR_CONSTRAINT_VIOLATION;
+		}
+		goto checked;
+	}
+
+	if (add_val_cnt == 1 && del_val_cnt == 0) {
+		pav->pwd_reset = true;
+
+		ret = acl_check_extended_right(tmp_ctx,
+					       module,
+					       req,
+					       objectclass,
+					       sd,
+					       acl_user_token(module),
+					       GUID_DRS_FORCE_CHANGE_PASSWORD,
+					       SEC_ADS_CONTROL_ACCESS,
+					       sid);
+		/* Very strange, but we get constraint violation in this case */
+		if (ret == LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS) {
+			ret = LDB_ERR_CONSTRAINT_VIOLATION;
+		}
+		goto checked;
+	}
+
+	/*
+	 * Everything else is handled by the password_hash module where it will
+	 * fail, but with the correct error code when the module is again
+	 * checking the attributes. As the change request will lack the
+	 * DSDB_CONTROL_PASSWORD_ACL_VALIDATION_OID control, we can be sure that
+	 * any modification attempt that went this way will be rejected.
+	 */
+
+	talloc_free(tmp_ctx);
+	return LDB_SUCCESS;
+
+checked:
+	if (ret != LDB_SUCCESS) {
+		dsdb_acl_debug(sd, acl_user_token(module),
+			       req->op.mod.message->dn,
+			       true,
+			       10);
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	ret = ldb_request_add_control(req,
+		DSDB_CONTROL_PASSWORD_ACL_VALIDATION_OID, false, pav);
+	if (ret != LDB_SUCCESS) {
+		ldb_debug(ldb_module_get_ctx(module), LDB_DEBUG_ERROR,
+			  "Unable to register ACL validation control!\n");
+		return ret;
+	}
+	return LDB_SUCCESS;
+}
+
+/*
+ * Context needed by acl_callback
+ */
+struct acl_callback_context {
+	struct ldb_request *request;
+	struct ldb_module *module;
+};
+
+/*
+ * @brief Copy the password validation control to the reply.
+ *
+ * Copy the dsdb_control_password_acl_validation control from the request,
+ * to the reply.  The control is used by the audit_log module to identify
+ * password rests.
+ *
+ * @param req the ldb request.
+ * @param ares the result, updated with the control.
+ */
+static void copy_password_acl_validation_control(
+	struct ldb_request *req,
+	struct ldb_reply *ares)
+{
+	struct ldb_control *pav_ctrl = NULL;
+	struct dsdb_control_password_acl_validation *pav = NULL;
+
+	pav_ctrl = ldb_request_get_control(
+		discard_const(req),
+		DSDB_CONTROL_PASSWORD_ACL_VALIDATION_OID);
+	if (pav_ctrl == NULL) {
+		return;
+	}
+
+	pav = talloc_get_type_abort(
+		pav_ctrl->data,
+		struct dsdb_control_password_acl_validation);
+	if (pav == NULL) {
+		return;
+	}
+	ldb_reply_add_control(
+		ares,
+		DSDB_CONTROL_PASSWORD_ACL_VALIDATION_OID,
+		false,
+		pav);
+}
+/*
+ * @brief call back function for acl_modify.
+ *
+ * Calls acl_copy to copy the dsdb_control_password_acl_validation from
+ * the request to the reply.
+ *
+ * @param req the ldb_request.
+ * @param ares the operation result.
+ *
+ * @return the LDB_STATUS
+ */
+static int acl_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+	struct acl_callback_context *ac = NULL;
+
+	ac = talloc_get_type(req->context, struct acl_callback_context);
+
+	if (!ares) {
+		return ldb_module_done(
+			ac->request,
+			NULL,
+			NULL,
+			LDB_ERR_OPERATIONS_ERROR);
+	}
+
+	/* pass on to the callback */
+	switch (ares->type) {
+	case LDB_REPLY_ENTRY:
+		return ldb_module_send_entry(
+			ac->request,
+			ares->message,
+			ares->controls);
+
+	case LDB_REPLY_REFERRAL:
+		return ldb_module_send_referral(
+			ac->request,
+			ares->referral);
+
+	case LDB_REPLY_DONE:
+		/*
+		 * Copy the ACL control from the request to the response
+		 */
+		copy_password_acl_validation_control(req, ares);
+		return ldb_module_done(
+			ac->request,
+			ares->controls,
+			ares->response,
+			ares->error);
+
+	default:
+		/* Can't happen */
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+}
+
+static int acl_modify(struct ldb_module *module, struct ldb_request *req)
+{
+	int ret;
+	struct ldb_context *ldb = ldb_module_get_ctx(module);
+	const struct dsdb_schema *schema;
+	unsigned int i;
+	const struct dsdb_class *objectclass;
+	struct ldb_result *acl_res;
+	struct security_descriptor *sd;
+	struct dom_sid *sid = NULL;
+	struct ldb_control *as_system;
+	struct ldb_control *is_undelete;
+	struct ldb_control *implicit_validated_write_control = NULL;
+	bool userPassword;
+	bool password_rights_checked = false;
+	TALLOC_CTX *tmp_ctx;
+	const struct ldb_message *msg = req->op.mod.message;
+	static const char *acl_attrs[] = {
+		"nTSecurityDescriptor",
+		"objectClass",
+		"objectSid",
+		NULL
+	};
+	struct acl_callback_context *context = NULL;
+	struct ldb_request *new_req = NULL;
+	struct  dsdb_control_password_acl_validation *pav = NULL;
+	struct ldb_control **controls = NULL;
+
+	if (ldb_dn_is_special(msg->dn)) {
+		return ldb_next_request(module, req);
+	}
+
+	as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
+	if (as_system != NULL) {
+		as_system->critical = 0;
+	}
+
+	is_undelete = ldb_request_get_control(req, DSDB_CONTROL_RESTORE_TOMBSTONE_OID);
+
+	implicit_validated_write_control = ldb_request_get_control(
+		req, DSDB_CONTROL_FORCE_ALLOW_VALIDATED_DNS_HOSTNAME_SPN_WRITE_OID);
+	if (implicit_validated_write_control != NULL) {
+		implicit_validated_write_control->critical = 0;
+	}
+
+	/* Don't print this debug statement if elements[0].name is going to be NULL */
+	if (msg->num_elements > 0) {
+		DEBUG(10, ("ldb:acl_modify: %s\n", msg->elements[0].name));
+	}
+	if (dsdb_module_am_system(module) || as_system) {
+		return ldb_next_request(module, req);
+	}
+
+	tmp_ctx = talloc_new(req);
+	if (tmp_ctx == NULL) {
+		return ldb_oom(ldb);
+	}
+
+	ret = dsdb_module_search_dn(module, tmp_ctx, &acl_res, msg->dn,
+				    acl_attrs,
+				    DSDB_FLAG_NEXT_MODULE |
+				    DSDB_FLAG_AS_SYSTEM |
+				    DSDB_SEARCH_SHOW_RECYCLED,
+				    req);
+
+	if (ret != LDB_SUCCESS) {
+		goto fail;
+	}
+
+	userPassword = dsdb_user_password_support(module, req, req);
+
+	schema = dsdb_get_schema(ldb, tmp_ctx);
+	if (!schema) {
+		talloc_free(tmp_ctx);
+		return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
+				 "acl_modify: Error obtaining schema.");
+	}
+
+	ret = dsdb_get_sd_from_ldb_message(ldb, tmp_ctx, acl_res->msgs[0], &sd);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
+				 "acl_modify: Error retrieving security descriptor.");
+	}
+	/* Theoretically we pass the check if the object has no sd */
+	if (!sd) {
+		goto success;
+	}
+
+	objectclass = dsdb_get_structural_oc_from_msg(schema, acl_res->msgs[0]);
+	if (!objectclass) {
+		talloc_free(tmp_ctx);
+		return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
+				 "acl_modify: Error retrieving object class for GUID.");
+	}
+	sid = samdb_result_dom_sid(req, acl_res->msgs[0], "objectSid");
+	for (i=0; i < msg->num_elements; i++) {
+		const struct ldb_message_element *el = &msg->elements[i];
+		const struct dsdb_attribute *attr;
+
+		/*
+		 * This basic attribute existence check with the right errorcode
+		 * is needed since this module is the first one which requests
+		 * schema attribute information.
+		 * The complete attribute checking is done in the
+		 * "objectclass_attrs" module behind this one.
+		 *
+		 * NOTE: "clearTextPassword" is not defined in the schema.
+		 */
+		attr = dsdb_attribute_by_lDAPDisplayName(schema, el->name);
+		if (!attr && ldb_attr_cmp("clearTextPassword", el->name) != 0) {
+			ldb_asprintf_errstring(ldb, "acl_modify: attribute '%s' "
+					       "on entry '%s' was not found in the schema!",
+					       req->op.mod.message->elements[i].name,
+				       ldb_dn_get_linearized(req->op.mod.message->dn));
+			ret =  LDB_ERR_NO_SUCH_ATTRIBUTE;
+			goto fail;
+		}
+
+		if (ldb_attr_cmp("nTSecurityDescriptor", el->name) == 0) {
+			uint32_t sd_flags = dsdb_request_sd_flags(req, NULL);
+			uint32_t access_mask = 0;
+
+			if (sd_flags & (SECINFO_OWNER|SECINFO_GROUP)) {
+				access_mask |= SEC_STD_WRITE_OWNER;
+			}
+			if (sd_flags & SECINFO_DACL) {
+				access_mask |= SEC_STD_WRITE_DAC;
+			}
+			if (sd_flags & SECINFO_SACL) {
+				access_mask |= SEC_FLAG_SYSTEM_SECURITY;
+			}
+
+			ret = acl_check_access_on_attribute(module,
+							    tmp_ctx,
+							    sd,
+							    sid,
+							    access_mask,
+							    attr,
+							    objectclass);
+			if (ret != LDB_SUCCESS) {
+				ldb_asprintf_errstring(ldb_module_get_ctx(module),
+						       "Object %s has no write dacl access\n",
+						       ldb_dn_get_linearized(msg->dn));
+				dsdb_acl_debug(sd,
+					       acl_user_token(module),
+					       msg->dn,
+					       true,
+					       10);
+				ret = LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
+				goto fail;
+			}
+		} else if (ldb_attr_cmp("member", el->name) == 0) {
+			ret = acl_check_self_membership(tmp_ctx,
+							module,
+							req,
+							sd,
+							sid,
+							attr,
+							objectclass);
+			if (ret != LDB_SUCCESS) {
+				goto fail;
+			}
+		} else if (ldb_attr_cmp("dBCSPwd", el->name) == 0) {
+			/* this one is not affected by any rights, we should let it through
+			   so that passwords_hash returns the correct error */
+			continue;
+		} else if (ldb_attr_cmp("unicodePwd", el->name) == 0 ||
+			   (userPassword && ldb_attr_cmp("userPassword", el->name) == 0) ||
+			   ldb_attr_cmp("clearTextPassword", el->name) == 0) {
+			/*
+			 * Ideally we would do the acl_check_password_rights
+			 * before we checked the other attributes, i.e. in a
+			 * loop before the current one.
+			 * Have not done this as yet in order to limit the size
+			 * of the change. To limit the possibility of breaking
+			 * the ACL logic.
+			 */
+			if (password_rights_checked) {
+				continue;
+			}
+			ret = acl_check_password_rights(tmp_ctx,
+							module,
+							req,
+							sd,
+							sid,
+							objectclass,
+							userPassword,
+							&pav);
+			if (ret != LDB_SUCCESS) {
+				goto fail;
+			}
+			password_rights_checked = true;
+		} else if (ldb_attr_cmp("servicePrincipalName", el->name) == 0) {
+			ret = acl_check_spn(tmp_ctx,
+					    module,
+					    req,
+					    el,
+					    sd,
+					    sid,
+					    attr,
+					    objectclass,
+					    implicit_validated_write_control);
+			if (ret != LDB_SUCCESS) {
+				goto fail;
+			}
+		} else if (ldb_attr_cmp("dnsHostName", el->name) == 0) {
+			ret = acl_check_dns_host_name(tmp_ctx,
+						      module,
+						      req,
+						      el,
+						      sd,
+						      sid,
+						      attr,
+						      objectclass,
+						      implicit_validated_write_control);
+			if (ret != LDB_SUCCESS) {
+				goto fail;
+			}
+		} else if (is_undelete != NULL && (ldb_attr_cmp("isDeleted", el->name) == 0)) {
+			/*
+			 * in case of undelete op permissions on
+			 * isDeleted are irrelevant and
+			 * distinguishedName is removed by the
+			 * tombstone_reanimate module
+			 */
+			continue;
+		} else if (implicit_validated_write_control != NULL) {
+			/* Allow the update. */
+			continue;
+		} else {
+			ret = acl_check_access_on_attribute(module,
+							    tmp_ctx,
+							    sd,
+							    sid,
+							    SEC_ADS_WRITE_PROP,
+							    attr,
+							    objectclass);
+			if (ret != LDB_SUCCESS) {
+				ldb_asprintf_errstring(ldb_module_get_ctx(module),
+						       "Object %s has no write property access\n",
+						       ldb_dn_get_linearized(msg->dn));
+				dsdb_acl_debug(sd,
+					       acl_user_token(module),
+					       msg->dn,
+					       true,
+					       10);
+				ret = LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
+				goto fail;
+			}
+		}
+	}
+
+success:
+	talloc_free(tmp_ctx);
+	context = talloc_zero(req, struct acl_callback_context);
+
+	if (context == NULL) {
+		return ldb_oom(ldb);
+	}
+	context->request = req;
+	context->module  = module;
+	ret = ldb_build_mod_req(
+		&new_req,
+		ldb,
+		req,
+		req->op.mod.message,
+		req->controls,
+		context,
+		acl_callback,
+		req);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	return ldb_next_request(module, new_req);
+fail:
+	talloc_free(tmp_ctx);
+	/*
+	 * We copy the pav into the result, so that the password reset
+	 * logging code in audit_log can log failed password reset attempts.
+	 */
+	if (pav) {
+		struct ldb_control *control = NULL;
+
+		controls = talloc_zero_array(req, struct ldb_control *, 2);
+		if (controls == NULL) {
+			return ldb_oom(ldb);
+		}
+
+		control = talloc(controls, struct ldb_control);
+
+		if (control == NULL) {
+			return ldb_oom(ldb);
+		}
+
+		control->oid= talloc_strdup(
+			control,
+			DSDB_CONTROL_PASSWORD_ACL_VALIDATION_OID);
+		if (control->oid == NULL) {
+			return ldb_oom(ldb);
+		}
+		control->critical	= false;
+		control->data	= pav;
+		*controls = control;
+	}
+	return ldb_module_done(req, controls, NULL, ret);
+}
+
+/* similar to the modify for the time being.
+ * We need to consider the special delete tree case, though - TODO */
+static int acl_delete(struct ldb_module *module, struct ldb_request *req)
+{
+	int ret;
+	struct ldb_dn *parent;
+	struct ldb_context *ldb;
+	struct ldb_dn *nc_root;
+	struct ldb_control *as_system;
+	const struct dsdb_schema *schema;
+	const struct dsdb_class *objectclass;
+	struct security_descriptor *sd = NULL;
+	struct dom_sid *sid = NULL;
+	struct ldb_result *acl_res;
+	static const char *acl_attrs[] = {
+		"nTSecurityDescriptor",
+		"objectClass",
+		"objectSid",
+		NULL
+	};
+
+	if (ldb_dn_is_special(req->op.del.dn)) {
+		return ldb_next_request(module, req);
+	}
+
+	as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
+	if (as_system != NULL) {
+		as_system->critical = 0;
+	}
+
+	if (dsdb_module_am_system(module) || as_system) {
+		return ldb_next_request(module, req);
+	}
+
+	DEBUG(10, ("ldb:acl_delete: %s\n", ldb_dn_get_linearized(req->op.del.dn)));
+
+	ldb = ldb_module_get_ctx(module);
+
+	parent = ldb_dn_get_parent(req, req->op.del.dn);
+	if (parent == NULL) {
+		return ldb_oom(ldb);
+	}
+
+	/* Make sure we aren't deleting a NC */
+
+	ret = dsdb_find_nc_root(ldb, req, req->op.del.dn, &nc_root);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	if (ldb_dn_compare(nc_root, req->op.del.dn) == 0) {
+		talloc_free(nc_root);
+		DEBUG(10,("acl:deleting a NC\n"));
+		/* Windows returns "ERR_UNWILLING_TO_PERFORM */
+		return ldb_module_done(req, NULL, NULL,
+				       LDB_ERR_UNWILLING_TO_PERFORM);
+	}
+	talloc_free(nc_root);
+
+	ret = dsdb_module_search_dn(module, req, &acl_res,
+				    req->op.del.dn, acl_attrs,
+				    DSDB_FLAG_NEXT_MODULE |
+				    DSDB_FLAG_AS_SYSTEM |
+				    DSDB_SEARCH_SHOW_RECYCLED, req);
+	/* we sould be able to find the parent */
+	if (ret != LDB_SUCCESS) {
+		DEBUG(10,("acl: failed to find object %s\n",
+			  ldb_dn_get_linearized(req->op.rename.olddn)));
+		return ret;
+	}
+
+	ret = dsdb_get_sd_from_ldb_message(ldb, req, acl_res->msgs[0], &sd);
+	if (ret != LDB_SUCCESS) {
+		return ldb_operr(ldb);
+	}
+	if (!sd) {
+		return ldb_operr(ldb);
+	}
+
+	schema = dsdb_get_schema(ldb, req);
+	if (!schema) {
+		return ldb_operr(ldb);
+	}
+
+	sid = samdb_result_dom_sid(req, acl_res->msgs[0], "objectSid");
+
+	objectclass = dsdb_get_structural_oc_from_msg(schema, acl_res->msgs[0]);
+	if (!objectclass) {
+		return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
+				 "acl_modify: Error retrieving object class for GUID.");
+	}
+
+	if (ldb_request_get_control(req, LDB_CONTROL_TREE_DELETE_OID)) {
+		ret = acl_check_access_on_objectclass(module, req, sd, sid,
+						      SEC_ADS_DELETE_TREE,
+						      objectclass);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+
+		return ldb_next_request(module, req);
+	}
+
+	/* First check if we have delete object right */
+	ret = acl_check_access_on_objectclass(module, req, sd, sid,
+					      SEC_STD_DELETE,
+					      objectclass);
+	if (ret == LDB_SUCCESS) {
+		return ldb_next_request(module, req);
+	}
+
+	/* Nope, we don't have delete object. Lets check if we have delete
+	 * child on the parent */
+	ret = dsdb_module_check_access_on_dn(module, req, parent,
+					     SEC_ADS_DELETE_CHILD,
+					     &objectclass->schemaIDGUID,
+					     req);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+
+	return ldb_next_request(module, req);
+}
+static int acl_check_reanimate_tombstone(TALLOC_CTX *mem_ctx,
+					 struct ldb_module *module,
+					 struct ldb_request *req,
+					 struct ldb_dn *nc_root)
+{
+	int ret;
+	struct ldb_result *acl_res;
+	struct security_descriptor *sd = NULL;
+	struct dom_sid *sid = NULL;
+	const struct dsdb_schema *schema = NULL;
+	const struct dsdb_class *objectclass = NULL;
+	struct ldb_context *ldb = ldb_module_get_ctx(module);
+	static const char *acl_attrs[] = {
+		"nTSecurityDescriptor",
+		"objectClass",
+		"objectSid",
+		NULL
+	};
+
+	ret = dsdb_module_search_dn(module, mem_ctx, &acl_res,
+				    nc_root, acl_attrs,
+				    DSDB_FLAG_NEXT_MODULE |
+				    DSDB_FLAG_AS_SYSTEM |
+				    DSDB_SEARCH_SHOW_RECYCLED, req);
+	if (ret != LDB_SUCCESS) {
+		DEBUG(10,("acl: failed to find object %s\n",
+			  ldb_dn_get_linearized(nc_root)));
+		return ret;
+	}
+
+	ret = dsdb_get_sd_from_ldb_message(mem_ctx, req, acl_res->msgs[0], &sd);
+	sid = samdb_result_dom_sid(mem_ctx, acl_res->msgs[0], "objectSid");
+	schema = dsdb_get_schema(ldb, req);
+	if (!schema) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	objectclass = dsdb_get_structural_oc_from_msg(schema, acl_res->msgs[0]);
+	if (ret != LDB_SUCCESS || !sd) {
+		return ldb_operr(ldb_module_get_ctx(module));
+	}
+	return acl_check_extended_right(mem_ctx,
+					module,
+					req,
+					objectclass,
+					sd,
+					acl_user_token(module),
+					GUID_DRS_REANIMATE_TOMBSTONE,
+					SEC_ADS_CONTROL_ACCESS, sid);
+}
+
+static int acl_rename(struct ldb_module *module, struct ldb_request *req)
+{
+	int ret;
+	struct ldb_dn *oldparent;
+	struct ldb_dn *newparent;
+	const struct dsdb_schema *schema;
+	const struct dsdb_class *objectclass;
+	const struct dsdb_attribute *attr = NULL;
+	struct ldb_context *ldb;
+	struct security_descriptor *sd = NULL;
+	struct dom_sid *sid = NULL;
+	struct ldb_result *acl_res;
+	struct ldb_dn *nc_root;
+	struct ldb_control *as_system;
+	struct ldb_control *is_undelete;
+	TALLOC_CTX *tmp_ctx;
+	const char *rdn_name;
+	static const char *acl_attrs[] = {
+		"nTSecurityDescriptor",
+		"objectClass",
+		"objectSid",
+		NULL
+	};
+
+	if (ldb_dn_is_special(req->op.rename.olddn)) {
+		return ldb_next_request(module, req);
+	}
+
+	as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
+	if (as_system != NULL) {
+		as_system->critical = 0;
+	}
+
+	DEBUG(10, ("ldb:acl_rename: %s\n", ldb_dn_get_linearized(req->op.rename.olddn)));
+	if (dsdb_module_am_system(module) || as_system) {
+		return ldb_next_request(module, req);
+	}
+
+	ldb = ldb_module_get_ctx(module);
+
+	tmp_ctx = talloc_new(req);
+	if (tmp_ctx == NULL) {
+		return ldb_oom(ldb);
+	}
+
+	oldparent = ldb_dn_get_parent(tmp_ctx, req->op.rename.olddn);
+	if (oldparent == NULL) {
+		return ldb_oom(ldb);
+	}
+	newparent = ldb_dn_get_parent(tmp_ctx, req->op.rename.newdn);
+	if (newparent == NULL) {
+		return ldb_oom(ldb);
+	}
+
+	/* Make sure we aren't renaming/moving a NC */
+
+	ret = dsdb_find_nc_root(ldb, req, req->op.rename.olddn, &nc_root);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	if (ldb_dn_compare(nc_root, req->op.rename.olddn) == 0) {
+		talloc_free(nc_root);
+		DEBUG(10,("acl:renaming/moving a NC\n"));
+		/* Windows returns "ERR_UNWILLING_TO_PERFORM */
+		return ldb_module_done(req, NULL, NULL,
+				       LDB_ERR_UNWILLING_TO_PERFORM);
+	}
+
+	/* special check for undelete operation */
+	is_undelete = ldb_request_get_control(req, DSDB_CONTROL_RESTORE_TOMBSTONE_OID);
+	if (is_undelete != NULL) {
+		is_undelete->critical = 0;
+		ret = acl_check_reanimate_tombstone(tmp_ctx, module, req, nc_root);
+		if (ret != LDB_SUCCESS) {
+			talloc_free(tmp_ctx);
+			return ret;
+		}
+	}
+	talloc_free(nc_root);
+
+	/* Look for the parent */
+
+	ret = dsdb_module_search_dn(module, tmp_ctx, &acl_res,
+				    req->op.rename.olddn, acl_attrs,
+				    DSDB_FLAG_NEXT_MODULE |
+				    DSDB_FLAG_AS_SYSTEM |
+				    DSDB_SEARCH_SHOW_RECYCLED, req);
+	/* we sould be able to find the parent */
+	if (ret != LDB_SUCCESS) {
+		DEBUG(10,("acl: failed to find object %s\n",
+			  ldb_dn_get_linearized(req->op.rename.olddn)));
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	ret = dsdb_get_sd_from_ldb_message(ldb, req, acl_res->msgs[0], &sd);
+	if (ret != LDB_SUCCESS) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+	if (!sd) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+
+	schema = dsdb_get_schema(ldb, acl_res);
+	if (!schema) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+
+	sid = samdb_result_dom_sid(req, acl_res->msgs[0], "objectSid");
+
+	objectclass = dsdb_get_structural_oc_from_msg(schema, acl_res->msgs[0]);
+	if (!objectclass) {
+		talloc_free(tmp_ctx);
+		return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
+				 "acl_modify: Error retrieving object class for GUID.");
+	}
+
+	attr = dsdb_attribute_by_lDAPDisplayName(schema, "name");
+	if (attr == NULL) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+
+	ret = acl_check_access_on_attribute(module, tmp_ctx, sd, sid,
+					    SEC_ADS_WRITE_PROP,
+					    attr, objectclass);
+	if (ret != LDB_SUCCESS) {
+		ldb_asprintf_errstring(ldb_module_get_ctx(module),
+				       "Object %s has no wp on %s\n",
+				       ldb_dn_get_linearized(req->op.rename.olddn),
+				       attr->lDAPDisplayName);
+		dsdb_acl_debug(sd,
+			  acl_user_token(module),
+			  req->op.rename.olddn,
+			  true,
+			  10);
+		talloc_free(tmp_ctx);
+		return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
+	}
+
+	rdn_name = ldb_dn_get_rdn_name(req->op.rename.olddn);
+	if (rdn_name == NULL) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+
+	attr = dsdb_attribute_by_lDAPDisplayName(schema, rdn_name);
+	if (attr == NULL) {
+		talloc_free(tmp_ctx);
+		return ldb_operr(ldb);
+	}
+
+	ret = acl_check_access_on_attribute(module, tmp_ctx, sd, sid,
+					    SEC_ADS_WRITE_PROP,
+					    attr, objectclass);
+	if (ret != LDB_SUCCESS) {
+		ldb_asprintf_errstring(ldb_module_get_ctx(module),
+				       "Object %s has no wp on %s\n",
+				       ldb_dn_get_linearized(req->op.rename.olddn),
+				       attr->lDAPDisplayName);
+		dsdb_acl_debug(sd,
+			  acl_user_token(module),
+			  req->op.rename.olddn,
+			  true,
+			  10);
+		talloc_free(tmp_ctx);
+		return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
+	}
+
+	if (ldb_dn_compare(oldparent, newparent) == 0) {
+		/* regular rename, not move, nothing more to do */
+		talloc_free(tmp_ctx);
+		return ldb_next_request(module, req);
+	}
+
+	/* new parent should have create child */
+	ret = dsdb_module_check_access_on_dn(module, req, newparent,
+					     SEC_ADS_CREATE_CHILD,
+					     &objectclass->schemaIDGUID, req);
+	if (ret != LDB_SUCCESS) {
+		ldb_asprintf_errstring(ldb_module_get_ctx(module),
+				       "acl:access_denied renaming %s",
+				       ldb_dn_get_linearized(req->op.rename.olddn));
+		talloc_free(tmp_ctx);
+		return ret;
+	}
+
+	/* do we have delete object on the object? */
+	/* this access is not necessary for undelete ops */
+	if (is_undelete == NULL) {
+		ret = acl_check_access_on_objectclass(module, tmp_ctx, sd, sid,
+						      SEC_STD_DELETE,
+						      objectclass);
+		if (ret == LDB_SUCCESS) {
+			talloc_free(tmp_ctx);
+			return ldb_next_request(module, req);
+		}
+		/* what about delete child on the current parent */
+		ret = dsdb_module_check_access_on_dn(module, req, oldparent,
+						     SEC_ADS_DELETE_CHILD,
+						     &objectclass->schemaIDGUID,
+						     req);
+		if (ret != LDB_SUCCESS) {
+			ldb_asprintf_errstring(ldb_module_get_ctx(module),
+					       "acl:access_denied renaming %s", ldb_dn_get_linearized(req->op.rename.olddn));
+			talloc_free(tmp_ctx);
+			return ldb_module_done(req, NULL, NULL, ret);
+		}
+	}
+	talloc_free(tmp_ctx);
+
+	return ldb_next_request(module, req);
+}
+
+static int acl_search_update_confidential_attrs(struct acl_context *ac,
+						struct acl_private *data)
+{
+	struct dsdb_attribute *a;
+	uint32_t n = 0;
+
+	if (data->acl_search) {
+		/*
+		 * If acl:search is activated, the acl_read module
+		 * protects confidential attributes.
+		 */
+		return LDB_SUCCESS;
+	}
+
+	if ((ac->schema == data->cached_schema_ptr) &&
+	    (ac->schema->metadata_usn == data->cached_schema_metadata_usn))
+	{
+		return LDB_SUCCESS;
+	}
+
+	data->cached_schema_ptr = NULL;
+	data->cached_schema_loaded_usn = 0;
+	data->cached_schema_metadata_usn = 0;
+	TALLOC_FREE(data->confidential_attrs);
+
+	if (ac->schema == NULL) {
+		return LDB_SUCCESS;
+	}
+
+	for (a = ac->schema->attributes; a; a = a->next) {
+		const char **attrs = data->confidential_attrs;
+
+		if (!(a->searchFlags & SEARCH_FLAG_CONFIDENTIAL)) {
+			continue;
+		}
+
+		attrs = talloc_realloc(data, attrs, const char *, n + 2);
+		if (attrs == NULL) {
+			TALLOC_FREE(data->confidential_attrs);
+			return ldb_module_oom(ac->module);
+		}
+
+		attrs[n] = a->lDAPDisplayName;
+		attrs[n+1] = NULL;
+		n++;
+
+		data->confidential_attrs = attrs;
+	}
+
+	data->cached_schema_ptr = ac->schema;
+	data->cached_schema_metadata_usn = ac->schema->metadata_usn;
+
+	return LDB_SUCCESS;
+}
+
+static int acl_search_callback(struct ldb_request *req, struct ldb_reply *ares)
+{
+	struct acl_context *ac;
+	struct acl_private *data;
+	struct ldb_result *acl_res;
+	static const char *acl_attrs[] = {
+		"objectClass",
+		"nTSecurityDescriptor",
+		"objectSid",
+		NULL
+	};
+	int ret;
+	unsigned int i;
+
+	ac = talloc_get_type(req->context, struct acl_context);
+	data = talloc_get_type(ldb_module_get_private(ac->module), struct acl_private);
+	if (!ares) {
+		return ldb_module_done(ac->req, NULL, NULL,
+				       LDB_ERR_OPERATIONS_ERROR);
+	}
+	if (ares->error != LDB_SUCCESS) {
+		return ldb_module_done(ac->req, ares->controls,
+				       ares->response, ares->error);
+	}
+
+	switch (ares->type) {
+	case LDB_REPLY_ENTRY:
+		if (ac->constructed_attrs) {
+			ret = dsdb_module_search_dn(ac->module, ac, &acl_res, ares->message->dn, 
+						    acl_attrs,
+						    DSDB_FLAG_NEXT_MODULE |
+						    DSDB_FLAG_AS_SYSTEM |
+						    DSDB_SEARCH_SHOW_RECYCLED,
+						    req);
+			if (ret != LDB_SUCCESS) {
+				return ldb_module_done(ac->req, NULL, NULL, ret);
+			}
+		}
+
+		if (ac->allowedAttributes || ac->allowedAttributesEffective) {
+			ret = acl_allowedAttributes(ac->module, ac->schema,
+						    acl_res->msgs[0],
+						    ares->message, ac);
+			if (ret != LDB_SUCCESS) {
+				return ldb_module_done(ac->req, NULL, NULL, ret);
+			}
+		}
+
+		if (ac->allowedChildClasses) {
+			ret = acl_childClasses(ac->module, ac->schema,
+					       acl_res->msgs[0],
+					       ares->message,
+					       "allowedChildClasses");
+			if (ret != LDB_SUCCESS) {
+				return ldb_module_done(ac->req, NULL, NULL, ret);
+			}
+		}
+
+		if (ac->allowedChildClassesEffective) {
+			ret = acl_childClassesEffective(ac->module, ac->schema,
+							acl_res->msgs[0],
+							ares->message, ac);
+			if (ret != LDB_SUCCESS) {
+				return ldb_module_done(ac->req, NULL, NULL, ret);
+			}
+		}
+
+		if (ac->sDRightsEffective) {
+			ret = acl_sDRightsEffective(ac->module,
+						    acl_res->msgs[0],
+						    ares->message, ac);
+			if (ret != LDB_SUCCESS) {
+				return ldb_module_done(ac->req, NULL, NULL, ret);
+			}
+		}
+
+		if (data == NULL) {
+			return ldb_module_send_entry(ac->req, ares->message,
+						     ares->controls);
+		}
+
+		if (ac->am_system) {
+			return ldb_module_send_entry(ac->req, ares->message,
+						     ares->controls);
+		}
+
+		if (ac->am_administrator) {
+			return ldb_module_send_entry(ac->req, ares->message,
+						     ares->controls);
+		}
+
+		if (data->confidential_attrs != NULL) {
+			for (i = 0; data->confidential_attrs[i]; i++) {
+				ldb_msg_remove_attr(ares->message,
+						    data->confidential_attrs[i]);
+			}
+		}
+
+		return ldb_module_send_entry(ac->req, ares->message, ares->controls);
+
+	case LDB_REPLY_REFERRAL:
+		return ldb_module_send_referral(ac->req, ares->referral);
+
+	case LDB_REPLY_DONE:
+		return ldb_module_done(ac->req, ares->controls,
+				       ares->response, LDB_SUCCESS);
+
+	}
+	return LDB_SUCCESS;
+}
+
+static int acl_search(struct ldb_module *module, struct ldb_request *req)
+{
+	struct ldb_context *ldb;
+	struct acl_context *ac;
+	struct ldb_parse_tree *down_tree = req->op.search.tree;
+	struct ldb_request *down_req;
+	struct acl_private *data;
+	int ret;
+	unsigned int i;
+	bool modify_search = true;
+
+	if (ldb_dn_is_special(req->op.search.base)) {
+		return ldb_next_request(module, req);
+	}
+
+	ldb = ldb_module_get_ctx(module);
+
+	ac = talloc_zero(req, struct acl_context);
+	if (ac == NULL) {
+		return ldb_oom(ldb);
+	}
+	data = talloc_get_type(ldb_module_get_private(module), struct acl_private);
+
+	ac->module = module;
+	ac->req = req;
+	ac->am_system = dsdb_module_am_system(module);
+	ac->am_administrator = dsdb_module_am_administrator(module);
+	ac->constructed_attrs = false;
+	ac->allowedAttributes = ldb_attr_in_list(req->op.search.attrs, "allowedAttributes");
+	ac->allowedAttributesEffective = ldb_attr_in_list(req->op.search.attrs, "allowedAttributesEffective");
+	ac->allowedChildClasses = ldb_attr_in_list(req->op.search.attrs, "allowedChildClasses");
+	ac->allowedChildClassesEffective = ldb_attr_in_list(req->op.search.attrs, "allowedChildClassesEffective");
+	ac->sDRightsEffective = ldb_attr_in_list(req->op.search.attrs, "sDRightsEffective");
+	ac->schema = dsdb_get_schema(ldb, ac);
+
+	ac->constructed_attrs |= ac->allowedAttributes;
+	ac->constructed_attrs |= ac->allowedChildClasses;
+	ac->constructed_attrs |= ac->allowedChildClassesEffective;
+	ac->constructed_attrs |= ac->allowedAttributesEffective;
+	ac->constructed_attrs |= ac->sDRightsEffective;
+
+	if (data == NULL) {
+		modify_search = false;
+	}
+	if (ac->am_system) {
+		modify_search = false;
+	}
+
+	if (!ac->constructed_attrs && !modify_search) {
+		talloc_free(ac);
+		return ldb_next_request(module, req);
+	}
+
+	data = talloc_get_type(ldb_module_get_private(ac->module), struct acl_private);
+	if (data == NULL) {
+		return ldb_error(ldb, LDB_ERR_OPERATIONS_ERROR,
+				 "acl_private data is missing");
+	}
+
+	if (!ac->am_system && !ac->am_administrator) {
+		ret = acl_search_update_confidential_attrs(ac, data);
+		if (ret != LDB_SUCCESS) {
+			return ret;
+		}
+
+		if (data->confidential_attrs != NULL) {
+			down_tree = ldb_parse_tree_copy_shallow(ac, req->op.search.tree);
+			if (down_tree == NULL) {
+				return ldb_oom(ldb);
+			}
+
+			for (i = 0; data->confidential_attrs[i]; i++) {
+				ldb_parse_tree_attr_replace(down_tree,
+							    data->confidential_attrs[i],
+							    "kludgeACLredactedattribute");
+			}
+		}
+	}
+
+	ret = ldb_build_search_req_ex(&down_req,
+				      ldb, ac,
+				      req->op.search.base,
+				      req->op.search.scope,
+				      down_tree,
+				      req->op.search.attrs,
+				      req->controls,
+				      ac, acl_search_callback,
+				      req);
+	LDB_REQ_SET_LOCATION(down_req);
+	if (ret != LDB_SUCCESS) {
+		return ret;
+	}
+	/* perform the search */
+	return ldb_next_request(module, down_req);
+}
+
+static int acl_extended(struct ldb_module *module, struct ldb_request *req)
+{
+	struct ldb_context *ldb = ldb_module_get_ctx(module);
+	struct ldb_control *as_system = ldb_request_get_control(req, LDB_CONTROL_AS_SYSTEM_OID);
+
+	/* allow everybody to read the sequence number */
+	if (strcmp(req->op.extended.oid,
+		   LDB_EXTENDED_SEQUENCE_NUMBER) == 0) {
+		return ldb_next_request(module, req);
+	}
+
+	if (dsdb_module_am_system(module) ||
+	    dsdb_module_am_administrator(module) || as_system) {
+		return ldb_next_request(module, req);
+	} else {
+		ldb_asprintf_errstring(ldb,
+				       "acl_extended: "
+				       "attempted database modify not permitted. "
+				       "User %s is not SYSTEM or an administrator",
+				       acl_user_name(req, module));
+		return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
+	}
+}
+
+static const struct ldb_module_ops ldb_acl_module_ops = {
+	.name		   = "acl",
+	.search            = acl_search,
+	.add               = acl_add,
+	.modify            = acl_modify,
+	.del               = acl_delete,
+	.rename            = acl_rename,
+	.extended          = acl_extended,
+	.init_context	   = acl_module_init
+};
+
+int ldb_acl_module_init(const char *version)
+{
+	LDB_MODULE_CHECK_VERSION(version);
+	return ldb_register_module(&ldb_acl_module_ops);
+}