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Edit File: drs_utils.py
# DRS utility code # # Copyright Andrew Tridgell 2010 # Copyright Andrew Bartlett 2017 # # 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/>. # from samba.dcerpc import drsuapi, misc, drsblobs from samba.net import Net from samba.ndr import ndr_unpack from samba import dsdb from samba import werror from samba import WERRORError import samba import ldb from samba.dcerpc.drsuapi import (DRSUAPI_ATTID_name, DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V8, DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V10) import re class drsException(Exception): """Base element for drs errors""" def __init__(self, value): self.value = value def __str__(self): return "drsException: " + self.value def drsuapi_connect(server, lp, creds, ip=None): """Make a DRSUAPI connection to the server. :param server: the name of the server to connect to :param lp: a samba line parameter object :param creds: credential used for the connection :param ip: Forced target server name :return: A tuple with the drsuapi bind object, the drsuapi handle and the supported extensions. :raise drsException: if the connection fails """ binding_options = "seal" if lp.log_level() >= 9: binding_options += ",print" # Allow forcing the IP if ip is not None: binding_options += f",target_hostname={server}" binding_string = f"ncacn_ip_tcp:{ip}[{binding_options}]" else: binding_string = "ncacn_ip_tcp:%s[%s]" % (server, binding_options) try: drsuapiBind = drsuapi.drsuapi(binding_string, lp, creds) (drsuapiHandle, bindSupportedExtensions) = drs_DsBind(drsuapiBind) except Exception as e: raise drsException("DRS connection to %s failed: %s" % (server, e)) return (drsuapiBind, drsuapiHandle, bindSupportedExtensions) def sendDsReplicaSync(drsuapiBind, drsuapi_handle, source_dsa_guid, naming_context, req_option): """Send DS replica sync request. :param drsuapiBind: a drsuapi Bind object :param drsuapi_handle: a drsuapi handle on the drsuapi connection :param source_dsa_guid: the guid of the source dsa for the replication :param naming_context: the DN of the naming context to replicate :param req_options: replication options for the DsReplicaSync call :raise drsException: if any error occur while sending and receiving the reply for the dsReplicaSync """ nc = drsuapi.DsReplicaObjectIdentifier() nc.dn = naming_context req1 = drsuapi.DsReplicaSyncRequest1() req1.naming_context = nc req1.options = req_option req1.source_dsa_guid = misc.GUID(source_dsa_guid) try: drsuapiBind.DsReplicaSync(drsuapi_handle, 1, req1) except Exception as estr: raise drsException("DsReplicaSync failed %s" % estr) def drs_DsBind(drs): '''make a DsBind call, returning the binding handle''' bind_info = drsuapi.DsBindInfoCtr() bind_info.length = 28 bind_info.info = drsuapi.DsBindInfo28() bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_BASE bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_ASYNC_REPLICATION bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_REMOVEAPI bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_MOVEREQ_V2 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHG_COMPRESS bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_DCINFO_V1 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_RESTORE_USN_OPTIMIZATION bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_KCC_EXECUTE bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_ADDENTRY_V2 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_LINKED_VALUE_REPLICATION bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_DCINFO_V2 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_INSTANCE_TYPE_NOT_REQ_ON_MOD bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_CRYPTO_BIND bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GET_REPL_INFO bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_STRONG_ENCRYPTION bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_DCINFO_V01 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_TRANSITIVE_MEMBERSHIP bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_ADD_SID_HISTORY bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_POST_BETA3 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GET_MEMBERSHIPS2 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V6 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_NONDOMAIN_NCS bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V8 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREPLY_V5 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREPLY_V6 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_ADDENTRYREPLY_V3 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_GETCHGREPLY_V7 bind_info.info.supported_extensions |= drsuapi.DRSUAPI_SUPPORTED_EXTENSION_VERIFY_OBJECT (info, handle) = drs.DsBind(misc.GUID(drsuapi.DRSUAPI_DS_BIND_GUID), bind_info) return (handle, info.info.supported_extensions) def drs_get_rodc_partial_attribute_set(samdb): '''get a list of attributes for RODC replication''' partial_attribute_set = drsuapi.DsPartialAttributeSet() partial_attribute_set.version = 1 attids = [] # the exact list of attids we send is quite critical. Note that # we do ask for the secret attributes, but set SPECIAL_SECRET_PROCESSING # to zero them out schema_dn = samdb.get_schema_basedn() res = samdb.search(base=schema_dn, scope=ldb.SCOPE_SUBTREE, expression="objectClass=attributeSchema", attrs=["lDAPDisplayName", "systemFlags", "searchFlags"]) for r in res: ldap_display_name = str(r["lDAPDisplayName"][0]) if "systemFlags" in r: system_flags = r["systemFlags"][0] if (int(system_flags) & (samba.dsdb.DS_FLAG_ATTR_NOT_REPLICATED | samba.dsdb.DS_FLAG_ATTR_IS_CONSTRUCTED)): continue if "searchFlags" in r: search_flags = r["searchFlags"][0] if (int(search_flags) & samba.dsdb.SEARCH_FLAG_RODC_ATTRIBUTE): continue attid = samdb.get_attid_from_lDAPDisplayName(ldap_display_name) attids.append(int(attid)) # the attids do need to be sorted, or windows doesn't return # all the attributes we need attids.sort() partial_attribute_set.attids = attids partial_attribute_set.num_attids = len(attids) return partial_attribute_set def drs_copy_highwater_mark(hwm, new_hwm): """ Copies the highwater mark by value, rather than by object reference. (This avoids lingering talloc references to old GetNCChanges reply messages). """ hwm.tmp_highest_usn = new_hwm.tmp_highest_usn hwm.reserved_usn = new_hwm.reserved_usn hwm.highest_usn = new_hwm.highest_usn class drs_Replicate(object): '''DRS replication calls''' def __init__(self, binding_string, lp, creds, samdb, invocation_id): self.drs = drsuapi.drsuapi(binding_string, lp, creds) (self.drs_handle, self.supports_ext) = drs_DsBind(self.drs) self.net = Net(creds=creds, lp=lp) self.samdb = samdb if not isinstance(invocation_id, misc.GUID): raise RuntimeError("Must supply GUID for invocation_id") if invocation_id == misc.GUID("00000000-0000-0000-0000-000000000000"): raise RuntimeError("Must not set GUID 00000000-0000-0000-0000-000000000000 as invocation_id") self.replication_state = self.net.replicate_init(self.samdb, lp, self.drs, invocation_id) self.more_flags = 0 def _should_retry_with_get_tgt(self, error_code, req): # If the error indicates we fail to resolve a target object for a # linked attribute, then we should retry the request with GET_TGT # (if we support it and haven't already tried that) supports_ext = self.supports_ext return (error_code == werror.WERR_DS_DRA_RECYCLED_TARGET and supports_ext & DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V10 and (req.more_flags & drsuapi.DRSUAPI_DRS_GET_TGT) == 0) @staticmethod def _should_calculate_missing_anc_locally(error_code, req): # If the error indicates we fail to resolve the parent object # for a new object, then we assume we are replicating from a # buggy server (Samba 4.5 and earlier) that doesn't really # understand how to implement GET_ANC return ((error_code == werror.WERR_DS_DRA_MISSING_PARENT) and (req.replica_flags & drsuapi.DRSUAPI_DRS_GET_ANC) != 0) def _calculate_missing_anc_locally(self, ctr): self.guids_seen = set() # walk objects in ctr, add to guid_seen as we see them # note if an object doesn't have a parent object_to_check = ctr.first_object while True: if object_to_check is None: break self.guids_seen.add(str(object_to_check.object.identifier.guid)) if object_to_check.parent_object_guid is not None \ and object_to_check.parent_object_guid \ != misc.GUID("00000000-0000-0000-0000-000000000000") \ and str(object_to_check.parent_object_guid) not in self.guids_seen: obj_dn = ldb.Dn(self.samdb, object_to_check.object.identifier.dn) parent_dn = obj_dn.parent() print(f"Object {parent_dn} with " f"GUID {object_to_check.parent_object_guid} " "was not sent by the server in this chunk") object_to_check = object_to_check.next_object def process_chunk(self, level, ctr, schema, req_level, req, first_chunk): '''Processes a single chunk of received replication data''' # pass the replication into the py_net.c python bindings for processing self.net.replicate_chunk(self.replication_state, level, ctr, schema=schema, req_level=req_level, req=req) def replicate(self, dn, source_dsa_invocation_id, destination_dsa_guid, schema=False, exop=drsuapi.DRSUAPI_EXOP_NONE, rodc=False, replica_flags=None, full_sync=True, sync_forced=False, more_flags=0): '''replicate a single DN''' # setup for a GetNCChanges call if self.supports_ext & DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V10: req = drsuapi.DsGetNCChangesRequest10() req.more_flags = (more_flags | self.more_flags) req_level = 10 else: req_level = 8 req = drsuapi.DsGetNCChangesRequest8() req.destination_dsa_guid = destination_dsa_guid req.source_dsa_invocation_id = source_dsa_invocation_id req.naming_context = drsuapi.DsReplicaObjectIdentifier() req.naming_context.dn = dn # Default to a full replication if we don't find an upToDatenessVector udv = None hwm = drsuapi.DsReplicaHighWaterMark() hwm.tmp_highest_usn = 0 hwm.reserved_usn = 0 hwm.highest_usn = 0 if not full_sync: res = self.samdb.search(base=dn, scope=ldb.SCOPE_BASE, attrs=["repsFrom"]) if "repsFrom" in res[0]: for reps_from_packed in res[0]["repsFrom"]: reps_from_obj = ndr_unpack(drsblobs.repsFromToBlob, reps_from_packed) if reps_from_obj.ctr.source_dsa_invocation_id == source_dsa_invocation_id: hwm = reps_from_obj.ctr.highwatermark udv = drsuapi.DsReplicaCursorCtrEx() udv.version = 1 udv.reserved1 = 0 udv.reserved2 = 0 cursors_v1 = [] cursors_v2 = dsdb._dsdb_load_udv_v2(self.samdb, self.samdb.get_default_basedn()) for cursor_v2 in cursors_v2: cursor_v1 = drsuapi.DsReplicaCursor() cursor_v1.source_dsa_invocation_id = cursor_v2.source_dsa_invocation_id cursor_v1.highest_usn = cursor_v2.highest_usn cursors_v1.append(cursor_v1) udv.cursors = cursors_v1 udv.count = len(cursors_v1) req.highwatermark = hwm req.uptodateness_vector = udv if replica_flags is not None: req.replica_flags = replica_flags elif exop == drsuapi.DRSUAPI_EXOP_REPL_SECRET: req.replica_flags = 0 else: req.replica_flags = (drsuapi.DRSUAPI_DRS_INIT_SYNC | drsuapi.DRSUAPI_DRS_PER_SYNC | drsuapi.DRSUAPI_DRS_GET_ANC | drsuapi.DRSUAPI_DRS_NEVER_SYNCED | drsuapi.DRSUAPI_DRS_GET_ALL_GROUP_MEMBERSHIP) if rodc: req.replica_flags |= ( drsuapi.DRSUAPI_DRS_SPECIAL_SECRET_PROCESSING) else: req.replica_flags |= drsuapi.DRSUAPI_DRS_WRIT_REP if sync_forced: req.replica_flags |= drsuapi.DRSUAPI_DRS_SYNC_FORCED req.max_object_count = 402 req.max_ndr_size = 402116 req.extended_op = exop req.fsmo_info = 0 req.partial_attribute_set = None req.partial_attribute_set_ex = None req.mapping_ctr.num_mappings = 0 req.mapping_ctr.mappings = None if not schema and rodc: req.partial_attribute_set = drs_get_rodc_partial_attribute_set(self.samdb) if not self.supports_ext & DRSUAPI_SUPPORTED_EXTENSION_GETCHGREQ_V8: req_level = 5 req5 = drsuapi.DsGetNCChangesRequest5() for a in dir(req5): if a[0] != '_': setattr(req5, a, getattr(req, a)) req = req5 num_objects = 0 num_links = 0 first_chunk = True while True: (level, ctr) = self.drs.DsGetNCChanges(self.drs_handle, req_level, req) if ctr.first_object is None and ctr.object_count != 0: raise RuntimeError("DsGetNCChanges: NULL first_object with object_count=%u" % (ctr.object_count)) try: self.process_chunk(level, ctr, schema, req_level, req, first_chunk) except WERRORError as e: # Check if retrying with the GET_TGT flag set might resolve this error if self._should_retry_with_get_tgt(e.args[0], req): print("Missing target object - retrying with DRS_GET_TGT") req.more_flags |= drsuapi.DRSUAPI_DRS_GET_TGT # try sending the request again (this has the side-effect # of causing the DC to restart the replication from scratch) first_chunk = True continue if self._should_calculate_missing_anc_locally(e.args[0], req): print("Missing parent object - calculating missing objects locally") self._calculate_missing_anc_locally(ctr) raise e first_chunk = False num_objects += ctr.object_count # Cope with servers that do not return level 6, so do not return any links try: num_links += ctr.linked_attributes_count except AttributeError: pass if ctr.more_data == 0: break # update the request's HWM so we get the next chunk drs_copy_highwater_mark(req.highwatermark, ctr.new_highwatermark) return (num_objects, num_links) # Handles the special case of creating a new clone of a DB, while also renaming # the entire DB's objects on the way through class drs_ReplicateRenamer(drs_Replicate): '''Uses DRS replication to rename the entire DB''' def __init__(self, binding_string, lp, creds, samdb, invocation_id, old_base_dn, new_base_dn): super(drs_ReplicateRenamer, self).__init__(binding_string, lp, creds, samdb, invocation_id) self.old_base_dn = old_base_dn self.new_base_dn = new_base_dn # because we're renaming the DNs, we know we're going to have trouble # resolving link targets. Normally we'd get to the end of replication # only to find we need to retry the whole replication with the GET_TGT # flag set. Always setting the GET_TGT flag avoids this extra work. self.more_flags = drsuapi.DRSUAPI_DRS_GET_TGT def rename_dn(self, dn_str): '''Uses string substitution to replace the base DN''' return re.sub('%s$' % self.old_base_dn, self.new_base_dn, dn_str) def update_name_attr(self, base_obj): '''Updates the 'name' attribute for the base DN object''' for attr in base_obj.attribute_ctr.attributes: if attr.attid == DRSUAPI_ATTID_name: base_dn = ldb.Dn(self.samdb, base_obj.identifier.dn) new_name = base_dn.get_rdn_value() attr.value_ctr.values[0].blob = new_name.encode('utf-16-le') def rename_top_level_object(self, first_obj): '''Renames the first/top-level object in a partition''' old_dn = first_obj.identifier.dn first_obj.identifier.dn = self.rename_dn(first_obj.identifier.dn) print("Renaming partition %s --> %s" % (old_dn, first_obj.identifier.dn)) # we also need to fix up the 'name' attribute for the base DN, # otherwise the RDNs won't match if first_obj.identifier.dn == self.new_base_dn: self.update_name_attr(first_obj) def process_chunk(self, level, ctr, schema, req_level, req, first_chunk): '''Processes a single chunk of received replication data''' # we need to rename the NC in every chunk - this gets used in searches # when applying the chunk if ctr.naming_context: ctr.naming_context.dn = self.rename_dn(ctr.naming_context.dn) # rename the first object in each partition. This will cause every # subsequent object in the partiton to be renamed as a side-effect if first_chunk and ctr.object_count != 0: self.rename_top_level_object(ctr.first_object.object) # then do the normal repl processing to apply this chunk to our DB super(drs_ReplicateRenamer, self).process_chunk(level, ctr, schema, req_level, req, first_chunk)