# Reads important GPO parameters and updates Samba # Copyright (C) Luke Morrison 2013 # # 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 . import sys import os, shutil import errno import tdb import pwd sys.path.insert(0, "bin/python") from samba import WERRORError from configparser import ConfigParser from io import StringIO import traceback from samba.common import get_bytes from abc import ABCMeta, abstractmethod import xml.etree.ElementTree as etree import re from samba.net import Net from samba.dcerpc import nbt from samba.samba3 import libsmb_samba_internal as libsmb import samba.gpo as gpo from uuid import UUID from tempfile import NamedTemporaryFile from samba.dcerpc import preg from samba.ndr import ndr_unpack from samba.credentials import SMB_SIGNING_REQUIRED from samba.gp.util.logging import log from hashlib import blake2b import numbers from samba.common import get_string from samba.samdb import SamDB from samba.auth import system_session import ldb from samba.dsdb import UF_WORKSTATION_TRUST_ACCOUNT, UF_SERVER_TRUST_ACCOUNT, GPLINK_OPT_ENFORCE, GPLINK_OPT_DISABLE, GPO_BLOCK_INHERITANCE from samba.auth import AUTH_SESSION_INFO_DEFAULT_GROUPS, AUTH_SESSION_INFO_AUTHENTICATED, AUTH_SESSION_INFO_SIMPLE_PRIVILEGES from samba.dcerpc import security import samba.security from samba.dcerpc import nbt from datetime import datetime try: from enum import Enum GPOSTATE = Enum('GPOSTATE', 'APPLY ENFORCE UNAPPLY') except ImportError: class GPOSTATE: APPLY = 1 ENFORCE = 2 UNAPPLY = 3 class gp_log: """ Log settings overwritten by gpo apply The gp_log is an xml file that stores a history of gpo changes (and the original setting value). The log is organized like so: -864000000000 -36288000000000 7 1 1d 300 Each guid value contains a list of extensions, which contain a list of attributes. The guid value represents a GPO. The attributes are the values of those settings prior to the application of the GPO. The list of guids is enclosed within a user name, which represents the user the settings were applied to. This user may be the samaccountname of the local computer, which implies that these are machine policies. The applylog keeps track of the order in which the GPOs were applied, so that they can be rolled back in reverse, returning the machine to the state prior to policy application. """ def __init__(self, user, gpostore, db_log=None): """ Initialize the gp_log param user - the username (or machine name) that policies are being applied to param gpostore - the GPOStorage obj which references the tdb which contains gp_logs param db_log - (optional) a string to initialize the gp_log """ self._state = GPOSTATE.APPLY self.gpostore = gpostore self.username = user if db_log: self.gpdb = etree.fromstring(db_log) else: self.gpdb = etree.Element('gp') self.user = user user_obj = self.gpdb.find('user[@name="%s"]' % user) if user_obj is None: user_obj = etree.SubElement(self.gpdb, 'user') user_obj.attrib['name'] = user def state(self, value): """ Policy application state param value - APPLY, ENFORCE, or UNAPPLY The behavior of the gp_log depends on whether we are applying policy, enforcing policy, or unapplying policy. During an apply, old settings are recorded in the log. During an enforce, settings are being applied but the gp_log does not change. During an unapply, additions to the log should be ignored (since function calls to apply settings are actually reverting policy), but removals from the log are allowed. """ # If we're enforcing, but we've unapplied, apply instead if value == GPOSTATE.ENFORCE: user_obj = self.gpdb.find('user[@name="%s"]' % self.user) apply_log = user_obj.find('applylog') if apply_log is None or len(apply_log) == 0: self._state = GPOSTATE.APPLY else: self._state = value else: self._state = value def get_state(self): """Check the GPOSTATE """ return self._state def set_guid(self, guid): """ Log to a different GPO guid param guid - guid value of the GPO from which we're applying policy """ self.guid = guid user_obj = self.gpdb.find('user[@name="%s"]' % self.user) obj = user_obj.find('guid[@value="%s"]' % guid) if obj is None: obj = etree.SubElement(user_obj, 'guid') obj.attrib['value'] = guid if self._state == GPOSTATE.APPLY: apply_log = user_obj.find('applylog') if apply_log is None: apply_log = etree.SubElement(user_obj, 'applylog') prev = apply_log.find('guid[@value="%s"]' % guid) if prev is None: item = etree.SubElement(apply_log, 'guid') item.attrib['count'] = '%d' % (len(apply_log) - 1) item.attrib['value'] = guid def store(self, gp_ext_name, attribute, old_val): """ Store an attribute in the gp_log param gp_ext_name - Name of the extension applying policy param attribute - The attribute being modified param old_val - The value of the attribute prior to policy application """ if self._state == GPOSTATE.UNAPPLY or self._state == GPOSTATE.ENFORCE: return None user_obj = self.gpdb.find('user[@name="%s"]' % self.user) guid_obj = user_obj.find('guid[@value="%s"]' % self.guid) assert guid_obj is not None, "gpo guid was not set" ext = guid_obj.find('gp_ext[@name="%s"]' % gp_ext_name) if ext is None: ext = etree.SubElement(guid_obj, 'gp_ext') ext.attrib['name'] = gp_ext_name attr = ext.find('attribute[@name="%s"]' % attribute) if attr is None: attr = etree.SubElement(ext, 'attribute') attr.attrib['name'] = attribute attr.text = old_val def retrieve(self, gp_ext_name, attribute): """ Retrieve a stored attribute from the gp_log param gp_ext_name - Name of the extension which applied policy param attribute - The attribute being retrieved return - The value of the attribute prior to policy application """ user_obj = self.gpdb.find('user[@name="%s"]' % self.user) guid_obj = user_obj.find('guid[@value="%s"]' % self.guid) assert guid_obj is not None, "gpo guid was not set" ext = guid_obj.find('gp_ext[@name="%s"]' % gp_ext_name) if ext is not None: attr = ext.find('attribute[@name="%s"]' % attribute) if attr is not None: return attr.text return None def retrieve_all(self, gp_ext_name): """ Retrieve all stored attributes for this user, GPO guid, and CSE param gp_ext_name - Name of the extension which applied policy return - The values of the attributes prior to policy application """ user_obj = self.gpdb.find('user[@name="%s"]' % self.user) guid_obj = user_obj.find('guid[@value="%s"]' % self.guid) assert guid_obj is not None, "gpo guid was not set" ext = guid_obj.find('gp_ext[@name="%s"]' % gp_ext_name) if ext is not None: attrs = ext.findall('attribute') return {attr.attrib['name']: attr.text for attr in attrs} return {} def get_applied_guids(self): """ Return a list of applied ext guids return - List of guids for gpos that have applied settings to the system. """ guids = [] user_obj = self.gpdb.find('user[@name="%s"]' % self.user) if user_obj is not None: apply_log = user_obj.find('applylog') if apply_log is not None: guid_objs = apply_log.findall('guid[@count]') guids_by_count = [(g.get('count'), g.get('value')) for g in guid_objs] guids_by_count.sort(reverse=True) guids.extend(guid for count, guid in guids_by_count) return guids def get_applied_settings(self, guids): """ Return a list of applied ext guids return - List of tuples containing the guid of a gpo, then a dictionary of policies and their values prior policy application. These are sorted so that the most recently applied settings are removed first. """ ret = [] user_obj = self.gpdb.find('user[@name="%s"]' % self.user) for guid in guids: guid_settings = user_obj.find('guid[@value="%s"]' % guid) exts = guid_settings.findall('gp_ext') settings = {} for ext in exts: attr_dict = {} attrs = ext.findall('attribute') for attr in attrs: attr_dict[attr.attrib['name']] = attr.text settings[ext.attrib['name']] = attr_dict ret.append((guid, settings)) return ret def delete(self, gp_ext_name, attribute): """ Remove an attribute from the gp_log param gp_ext_name - name of extension from which to remove the attribute param attribute - attribute to remove """ user_obj = self.gpdb.find('user[@name="%s"]' % self.user) guid_obj = user_obj.find('guid[@value="%s"]' % self.guid) assert guid_obj is not None, "gpo guid was not set" ext = guid_obj.find('gp_ext[@name="%s"]' % gp_ext_name) if ext is not None: attr = ext.find('attribute[@name="%s"]' % attribute) if attr is not None: ext.remove(attr) if len(ext) == 0: guid_obj.remove(ext) def commit(self): """ Write gp_log changes to disk """ self.gpostore.store(self.username, etree.tostring(self.gpdb, 'utf-8')) class GPOStorage: def __init__(self, log_file): if os.path.isfile(log_file): self.log = tdb.open(log_file) else: self.log = tdb.Tdb(log_file, 0, tdb.DEFAULT, os.O_CREAT | os.O_RDWR) def start(self): self.log.transaction_start() def get_int(self, key): try: return int(self.log.get(get_bytes(key))) except TypeError: return None def get(self, key): return self.log.get(get_bytes(key)) def get_gplog(self, user): return gp_log(user, self, self.log.get(get_bytes(user))) def store(self, key, val): self.log.store(get_bytes(key), get_bytes(val)) def cancel(self): self.log.transaction_cancel() def delete(self, key): self.log.delete(get_bytes(key)) def commit(self): self.log.transaction_commit() def __del__(self): self.log.close() class gp_ext(object): __metaclass__ = ABCMeta def __init__(self, lp, creds, username, store): self.lp = lp self.creds = creds self.username = username self.gp_db = store.get_gplog(username) @abstractmethod def process_group_policy(self, deleted_gpo_list, changed_gpo_list): pass @abstractmethod def read(self, policy): pass def parse(self, afile): local_path = self.lp.cache_path('gpo_cache') data_file = os.path.join(local_path, check_safe_path(afile).upper()) if os.path.exists(data_file): return self.read(data_file) return None @abstractmethod def __str__(self): pass @abstractmethod def rsop(self, gpo): return {} class gp_inf_ext(gp_ext): def read(self, data_file): with open(data_file, 'rb') as f: policy = f.read() inf_conf = ConfigParser(interpolation=None) inf_conf.optionxform = str try: inf_conf.read_file(StringIO(policy.decode())) except UnicodeDecodeError: inf_conf.read_file(StringIO(policy.decode('utf-16'))) return inf_conf class gp_pol_ext(gp_ext): def read(self, data_file): with open(data_file, 'rb') as f: raw = f.read() return ndr_unpack(preg.file, raw) class gp_xml_ext(gp_ext): def read(self, data_file): with open(data_file, 'rb') as f: raw = f.read() try: return etree.fromstring(raw.decode()) except UnicodeDecodeError: return etree.fromstring(raw.decode('utf-16')) class gp_applier(object): """Group Policy Applier/Unapplier/Modifier The applier defines functions for monitoring policy application, removal, and modification. It must be a multi-derived class paired with a subclass of gp_ext. """ __metaclass__ = ABCMeta def cache_add_attribute(self, guid, attribute, value): """Add an attribute and value to the Group Policy cache guid - The GPO guid which applies this policy attribute - The attribute name of the policy being applied value - The value of the policy being applied Normally called by the subclass apply() function after applying policy. """ self.gp_db.set_guid(guid) self.gp_db.store(str(self), attribute, value) self.gp_db.commit() def cache_remove_attribute(self, guid, attribute): """Remove an attribute from the Group Policy cache guid - The GPO guid which applies this policy attribute - The attribute name of the policy being unapplied Normally called by the subclass unapply() function when removing old policy. """ self.gp_db.set_guid(guid) self.gp_db.delete(str(self), attribute) self.gp_db.commit() def cache_get_attribute_value(self, guid, attribute): """Retrieve the value stored in the cache for the given attribute guid - The GPO guid which applies this policy attribute - The attribute name of the policy """ self.gp_db.set_guid(guid) return self.gp_db.retrieve(str(self), attribute) def cache_get_all_attribute_values(self, guid): """Retrieve all attribute/values currently stored for this gpo+policy guid - The GPO guid which applies this policy """ self.gp_db.set_guid(guid) return self.gp_db.retrieve_all(str(self)) def cache_get_apply_state(self): """Return the current apply state return - APPLY|ENFORCE|UNAPPLY """ return self.gp_db.get_state() def generate_attribute(self, name, *args): """Generate an attribute name from arbitrary data name - A name to ensure uniqueness args - Any arbitrary set of args, str or bytes return - A blake2b digest of the data, the attribute The importance here is the digest of the data makes the attribute reproducible and uniquely identifies it. Hashing the name with the data ensures we don't falsely identify a match which is the same text in a different file. Using this attribute generator is optional. """ data = b''.join([get_bytes(arg) for arg in [*args]]) return blake2b(get_bytes(name)+data).hexdigest() def generate_value_hash(self, *args): """Generate a unique value which identifies value changes args - Any arbitrary set of args, str or bytes return - A blake2b digest of the data, the value represented """ data = b''.join([get_bytes(arg) for arg in [*args]]) return blake2b(data).hexdigest() @abstractmethod def unapply(self, guid, attribute, value): """Group Policy Unapply guid - The GPO guid which applies this policy attribute - The attribute name of the policy being unapplied value - The value of the policy being unapplied """ pass @abstractmethod def apply(self, guid, attribute, applier_func, *args): """Group Policy Apply guid - The GPO guid which applies this policy attribute - The attribute name of the policy being applied applier_func - An applier function which takes variable args args - The variable arguments to pass to applier_func The applier_func function MUST return the value of the policy being applied. It's important that implementations of `apply` check for and first unapply any changed policy. See for example calls to `cache_get_all_attribute_values()` which searches for all policies applied by this GPO for this Client Side Extension (CSE). """ pass def clean(self, guid, keep=None, remove=None, **kwargs): """Cleanup old removed attributes keep - A list of attributes to keep remove - A single attribute to remove, or a list of attributes to remove kwargs - Additional keyword args required by the subclass unapply function This is only necessary for CSEs which provide multiple attributes. """ # Clean syntax is, either provide a single remove attribute, # or a list of either removal attributes or keep attributes. if keep is None: keep = [] if remove is None: remove = [] if type(remove) != list: value = self.cache_get_attribute_value(guid, remove) if value is not None: self.unapply(guid, remove, value, **kwargs) else: old_vals = self.cache_get_all_attribute_values(guid) for attribute, value in old_vals.items(): if (len(remove) > 0 and attribute in remove) or \ (len(keep) > 0 and attribute not in keep): self.unapply(guid, attribute, value, **kwargs) class gp_misc_applier(gp_applier): """Group Policy Miscellaneous Applier/Unapplier/Modifier """ def generate_value(self, **kwargs): data = etree.Element('data') for k, v in kwargs.items(): arg = etree.SubElement(data, k) arg.text = get_string(v) return get_string(etree.tostring(data, 'utf-8')) def parse_value(self, value): vals = {} try: data = etree.fromstring(value) except etree.ParseError: # If parsing fails, then it's an old cache value return {'old_val': value} except TypeError: return {} itr = data.iter() next(itr) # Skip the top element for item in itr: vals[item.tag] = item.text return vals class gp_file_applier(gp_applier): """Group Policy File Applier/Unapplier/Modifier Subclass of abstract class gp_applier for monitoring policy applied via a file. """ def __generate_value(self, value_hash, files, sep): data = [value_hash] data.extend(files) return sep.join(data) def __parse_value(self, value, sep): """Parse a value return - A unique HASH, followed by the file list """ if value is None: return None, [] data = value.split(sep) if '/' in data[0]: # The first element is not a hash, but a filename. This is a # legacy value. return None, data else: return data[0], data[1:] if len(data) > 1 else [] def unapply(self, guid, attribute, files, sep=':'): # If the value isn't a list of files, parse value from the log if type(files) != list: _, files = self.__parse_value(files, sep) for file in files: if os.path.exists(file): os.unlink(file) self.cache_remove_attribute(guid, attribute) def apply(self, guid, attribute, value_hash, applier_func, *args, sep=':'): """ applier_func MUST return a list of files created by the applier. This applier is for policies which only apply to a single file (with a couple small exceptions). This applier will remove any policy applied by this GPO which doesn't match the new policy. """ # If the policy has changed, unapply, then apply new policy old_val = self.cache_get_attribute_value(guid, attribute) # Ignore removal if this policy is applied and hasn't changed old_val_hash, old_val_files = self.__parse_value(old_val, sep) if (old_val_hash != value_hash or self.cache_get_apply_state() == GPOSTATE.ENFORCE) or \ not all([os.path.exists(f) for f in old_val_files]): self.unapply(guid, attribute, old_val_files) else: # If policy is already applied, skip application return # Apply the policy and log the changes files = applier_func(*args) new_value = self.__generate_value(value_hash, files, sep) self.cache_add_attribute(guid, attribute, new_value) """ Fetch the hostname of a writable DC """ def get_dc_hostname(creds, lp): net = Net(creds=creds, lp=lp) cldap_ret = net.finddc(domain=lp.get('realm'), flags=(nbt.NBT_SERVER_LDAP | nbt.NBT_SERVER_DS)) return cldap_ret.pdc_dns_name """ Fetch a list of GUIDs for applicable GPOs """ def get_gpo(samdb, gpo_dn): g = gpo.GROUP_POLICY_OBJECT() attrs = [ "cn", "displayName", "flags", "gPCFileSysPath", "gPCFunctionalityVersion", "gPCMachineExtensionNames", "gPCUserExtensionNames", "gPCWQLFilter", "name", "nTSecurityDescriptor", "versionNumber" ] if gpo_dn.startswith("LDAP://"): gpo_dn = gpo_dn.lstrip("LDAP://") sd_flags = (security.SECINFO_OWNER | security.SECINFO_GROUP | security.SECINFO_DACL) try: res = samdb.search(gpo_dn, ldb.SCOPE_BASE, "(objectclass=*)", attrs, controls=['sd_flags:1:%d' % sd_flags]) except Exception: log.error('Failed to fetch gpo object with nTSecurityDescriptor') raise if res.count != 1: raise ldb.LdbError(ldb.ERR_NO_SUCH_OBJECT, 'get_gpo: search failed') g.ds_path = gpo_dn if 'versionNumber' in res.msgs[0].keys(): g.version = int(res.msgs[0]['versionNumber'][0]) if 'flags' in res.msgs[0].keys(): g.options = int(res.msgs[0]['flags'][0]) if 'gPCFileSysPath' in res.msgs[0].keys(): g.file_sys_path = res.msgs[0]['gPCFileSysPath'][0].decode() if 'displayName' in res.msgs[0].keys(): g.display_name = res.msgs[0]['displayName'][0].decode() if 'name' in res.msgs[0].keys(): g.name = res.msgs[0]['name'][0].decode() if 'gPCMachineExtensionNames' in res.msgs[0].keys(): g.machine_extensions = str(res.msgs[0]['gPCMachineExtensionNames'][0]) if 'gPCUserExtensionNames' in res.msgs[0].keys(): g.user_extensions = str(res.msgs[0]['gPCUserExtensionNames'][0]) if 'nTSecurityDescriptor' in res.msgs[0].keys(): g.set_sec_desc(bytes(res.msgs[0]['nTSecurityDescriptor'][0])) return g class GP_LINK: def __init__(self, gPLink, gPOptions): self.link_names = [] self.link_opts = [] self.gpo_parse_gplink(gPLink) self.gp_opts = int(gPOptions) def gpo_parse_gplink(self, gPLink): for p in gPLink.decode().split(']'): if not p: continue log.debug('gpo_parse_gplink: processing link') p = p.lstrip('[') link_name, link_opt = p.split(';') log.debug('gpo_parse_gplink: link: {}'.format(link_name)) log.debug('gpo_parse_gplink: opt: {}'.format(link_opt)) self.link_names.append(link_name) self.link_opts.append(int(link_opt)) def num_links(self): if len(self.link_names) != len(self.link_opts): raise RuntimeError('Link names and opts mismatch') return len(self.link_names) def find_samaccount(samdb, samaccountname): attrs = ['dn', 'userAccountControl'] res = samdb.search(samdb.get_default_basedn(), ldb.SCOPE_SUBTREE, '(sAMAccountName={})'.format(samaccountname), attrs) if res.count != 1: raise ldb.LdbError(ldb.ERR_NO_SUCH_OBJECT, "Failed to find samAccountName '{}'".format(samaccountname) ) uac = int(res.msgs[0]['userAccountControl'][0]) dn = res.msgs[0]['dn'] log.info('Found dn {} for samaccountname {}'.format(dn, samaccountname)) return uac, dn def get_gpo_link(samdb, link_dn): res = samdb.search(link_dn, ldb.SCOPE_BASE, '(objectclass=*)', ['gPLink', 'gPOptions']) if res.count != 1: raise ldb.LdbError(ldb.ERR_NO_SUCH_OBJECT, 'get_gpo_link: no result') if 'gPLink' not in res.msgs[0]: raise ldb.LdbError(ldb.ERR_NO_SUCH_ATTRIBUTE, "get_gpo_link: no 'gPLink' attribute found for '{}'".format(link_dn) ) gPLink = res.msgs[0]['gPLink'][0] gPOptions = 0 if 'gPOptions' in res.msgs[0]: gPOptions = res.msgs[0]['gPOptions'][0] else: log.debug("get_gpo_link: no 'gPOptions' attribute found") return GP_LINK(gPLink, gPOptions) def add_gplink_to_gpo_list(samdb, gpo_list, forced_gpo_list, link_dn, gp_link, link_type, only_add_forced_gpos, token): for i in range(gp_link.num_links()-1, -1, -1): is_forced = (gp_link.link_opts[i] & GPLINK_OPT_ENFORCE) != 0 if gp_link.link_opts[i] & GPLINK_OPT_DISABLE: log.debug('skipping disabled GPO') continue if only_add_forced_gpos: if not is_forced: log.debug("skipping nonenforced GPO link " "because GPOPTIONS_BLOCK_INHERITANCE " "has been set") continue else: log.debug("adding enforced GPO link although " "the GPOPTIONS_BLOCK_INHERITANCE " "has been set") try: new_gpo = get_gpo(samdb, gp_link.link_names[i]) except ldb.LdbError as e: (enum, estr) = e.args log.debug("failed to get gpo: %s" % gp_link.link_names[i]) if enum == ldb.ERR_NO_SUCH_OBJECT: log.debug("skipping empty gpo: %s" % gp_link.link_names[i]) continue return else: try: sec_desc = ndr_unpack(security.descriptor, new_gpo.get_sec_desc_buf()) samba.security.access_check(sec_desc, token, security.SEC_STD_READ_CONTROL | security.SEC_ADS_LIST | security.SEC_ADS_READ_PROP) except Exception as e: log.debug("skipping GPO \"%s\" as object " "has no access to it" % new_gpo.display_name) continue new_gpo.link = str(link_dn) new_gpo.link_type = link_type if is_forced: forced_gpo_list.insert(0, new_gpo) else: gpo_list.insert(0, new_gpo) log.debug("add_gplink_to_gpo_list: added GPLINK #%d %s " "to GPO list" % (i, gp_link.link_names[i])) def merge_with_system_token(token_1): sids = token_1.sids system_token = system_session().security_token sids.extend(system_token.sids) token_1.sids = sids token_1.rights_mask |= system_token.rights_mask token_1.privilege_mask |= system_token.privilege_mask # There are no claims in the system token, so it is safe not to merge the claims return token_1 def site_dn_for_machine(samdb, dc_hostname, lp, creds, hostname): # [MS-GPOL] 3.2.5.1.4 Site Search # The netr_DsRGetSiteName() needs to run over local rpc, however we do not # have the call implemented in our rpc_server. # What netr_DsRGetSiteName() actually does is an ldap query to get # the sitename, we can do the same. # NtVer=(NETLOGON_NT_VERSION_IP|NETLOGON_NT_VERSION_WITH_CLOSEST_SITE| # NETLOGON_NT_VERSION_5EX) [0x20000014] expr = "(&(DnsDomain=%s.)(User=%s)(NtVer=\\14\\00\\00\\20))" % ( samdb.domain_dns_name(), hostname) res = samdb.search( base='', scope=ldb.SCOPE_BASE, expression=expr, attrs=["Netlogon"]) if res.count != 1: raise RuntimeError('site_dn_for_machine: No result') samlogon_response = ndr_unpack(nbt.netlogon_samlogon_response, bytes(res.msgs[0]['Netlogon'][0])) if samlogon_response.ntver not in [nbt.NETLOGON_NT_VERSION_5EX, (nbt.NETLOGON_NT_VERSION_1 | nbt.NETLOGON_NT_VERSION_5EX)]: raise RuntimeError('site_dn_for_machine: Invalid NtVer in ' + 'netlogon_samlogon_response') # We want NETLOGON_NT_VERSION_5EX out of the union! samlogon_response.ntver = nbt.NETLOGON_NT_VERSION_5EX samlogon_response_ex = samlogon_response.data client_site = "Default-First-Site-Name" if (samlogon_response_ex.client_site and len(samlogon_response_ex.client_site) > 1): client_site = samlogon_response_ex.client_site site_dn = samdb.get_config_basedn() site_dn.add_child("CN=Sites") site_dn.add_child("CN=%s" % (client_site)) return site_dn def get_gpo_list(dc_hostname, creds, lp, username): """Get the full list of GROUP_POLICY_OBJECTs for a given username. Push GPOs to gpo_list so that the traversal order of the list matches the order of application: (L)ocal (S)ite (D)omain (O)rganizational(U)nit For different domains and OUs: parent-to-child. Within same level of domains and OUs: Link order. Since GPOs are pushed to the front of gpo_list, GPOs have to be pushed in the opposite order of application (OUs first, local last, child-to-parent). Forced GPOs are appended in the end since they override all others. """ gpo_list = [] forced_gpo_list = [] url = 'ldap://' + dc_hostname samdb = SamDB(url=url, session_info=system_session(), credentials=creds, lp=lp) # username is DOM\\SAM, but get_gpo_list expects SAM uac, dn = find_samaccount(samdb, username.split('\\')[-1]) add_only_forced_gpos = False # Fetch the security token session_info_flags = (AUTH_SESSION_INFO_DEFAULT_GROUPS | AUTH_SESSION_INFO_AUTHENTICATED) if url.startswith('ldap'): session_info_flags |= AUTH_SESSION_INFO_SIMPLE_PRIVILEGES session = samba.auth.user_session(samdb, lp_ctx=lp, dn=dn, session_info_flags=session_info_flags) gpo_list_machine = False if uac & UF_WORKSTATION_TRUST_ACCOUNT or uac & UF_SERVER_TRUST_ACCOUNT: gpo_list_machine = True token = merge_with_system_token(session.security_token) else: token = session.security_token # (O)rganizational(U)nit parent_dn = dn.parent() while True: if str(parent_dn) == str(samdb.get_default_basedn().parent()): break # An account can be a member of more OUs if parent_dn.get_component_name(0) == 'OU': try: log.debug("get_gpo_list: query OU: [%s] for GPOs" % parent_dn) gp_link = get_gpo_link(samdb, parent_dn) except ldb.LdbError as e: (enum, estr) = e.args log.debug(estr) else: add_gplink_to_gpo_list(samdb, gpo_list, forced_gpo_list, parent_dn, gp_link, gpo.GP_LINK_OU, add_only_forced_gpos, token) # block inheritance from now on if gp_link.gp_opts & GPO_BLOCK_INHERITANCE: add_only_forced_gpos = True parent_dn = parent_dn.parent() # (D)omain parent_dn = dn.parent() while True: if str(parent_dn) == str(samdb.get_default_basedn().parent()): break # An account can just be a member of one domain if parent_dn.get_component_name(0) == 'DC': try: log.debug("get_gpo_list: query DC: [%s] for GPOs" % parent_dn) gp_link = get_gpo_link(samdb, parent_dn) except ldb.LdbError as e: (enum, estr) = e.args log.debug(estr) else: add_gplink_to_gpo_list(samdb, gpo_list, forced_gpo_list, parent_dn, gp_link, gpo.GP_LINK_DOMAIN, add_only_forced_gpos, token) # block inheritance from now on if gp_link.gp_opts & GPO_BLOCK_INHERITANCE: add_only_forced_gpos = True parent_dn = parent_dn.parent() # (S)ite if gpo_list_machine: try: site_dn = site_dn_for_machine(samdb, dc_hostname, lp, creds, username) try: log.debug("get_gpo_list: query SITE: [%s] for GPOs" % site_dn) gp_link = get_gpo_link(samdb, site_dn) except ldb.LdbError as e: (enum, estr) = e.args log.debug(estr) else: add_gplink_to_gpo_list(samdb, gpo_list, forced_gpo_list, site_dn, gp_link, gpo.GP_LINK_SITE, add_only_forced_gpos, token) except ldb.LdbError: # [MS-GPOL] 3.2.5.1.4 Site Search: If the method returns # ERROR_NO_SITENAME, the remainder of this message MUST be skipped # and the protocol sequence MUST continue at GPO Search pass # (L)ocal gpo_list.insert(0, gpo.GROUP_POLICY_OBJECT("Local Policy", "Local Policy", gpo.GP_LINK_LOCAL)) # Append |forced_gpo_list| at the end of |gpo_list|, # so that forced GPOs are applied on top of non enforced GPOs. return gpo_list+forced_gpo_list def cache_gpo_dir(conn, cache, sub_dir): loc_sub_dir = sub_dir.upper() local_dir = os.path.join(cache, loc_sub_dir) try: os.makedirs(local_dir, mode=0o755) except OSError as e: if e.errno != errno.EEXIST: raise for fdata in conn.list(sub_dir): if fdata['attrib'] & libsmb.FILE_ATTRIBUTE_DIRECTORY: cache_gpo_dir(conn, cache, os.path.join(sub_dir, fdata['name'])) else: local_name = fdata['name'].upper() f = NamedTemporaryFile(delete=False, dir=local_dir) fname = os.path.join(sub_dir, fdata['name']).replace('/', '\\') f.write(conn.loadfile(fname)) f.close() os.rename(f.name, os.path.join(local_dir, local_name)) def check_safe_path(path): dirs = re.split('/|\\\\', path) if 'sysvol' in path.lower(): ldirs = re.split('/|\\\\', path.lower()) dirs = dirs[ldirs.index('sysvol') + 1:] if '..' not in dirs: return os.path.join(*dirs) raise OSError(path) def check_refresh_gpo_list(dc_hostname, lp, creds, gpos): # Force signing for the connection saved_signing_state = creds.get_smb_signing() creds.set_smb_signing(SMB_SIGNING_REQUIRED) conn = libsmb.Conn(dc_hostname, 'sysvol', lp=lp, creds=creds) # Reset signing state creds.set_smb_signing(saved_signing_state) cache_path = lp.cache_path('gpo_cache') for gpo_obj in gpos: if not gpo_obj.file_sys_path: continue cache_gpo_dir(conn, cache_path, check_safe_path(gpo_obj.file_sys_path)) def get_deleted_gpos_list(gp_db, gpos): applied_gpos = gp_db.get_applied_guids() current_guids = set([p.name for p in gpos]) deleted_gpos = [guid for guid in applied_gpos if guid not in current_guids] return gp_db.get_applied_settings(deleted_gpos) def gpo_version(lp, path): # gpo.gpo_get_sysvol_gpt_version() reads the GPT.INI from a local file, # read from the gpo client cache. gpt_path = lp.cache_path(os.path.join('gpo_cache', path)) return int(gpo.gpo_get_sysvol_gpt_version(gpt_path)[1]) def apply_gp(lp, creds, store, gp_extensions, username, target, force=False): gp_db = store.get_gplog(username) dc_hostname = get_dc_hostname(creds, lp) gpos = get_gpo_list(dc_hostname, creds, lp, username) del_gpos = get_deleted_gpos_list(gp_db, gpos) try: check_refresh_gpo_list(dc_hostname, lp, creds, gpos) except: log.error('Failed downloading gpt cache from \'%s\' using SMB' % dc_hostname) return if force: changed_gpos = gpos gp_db.state(GPOSTATE.ENFORCE) else: changed_gpos = [] for gpo_obj in gpos: if not gpo_obj.file_sys_path: continue guid = gpo_obj.name path = check_safe_path(gpo_obj.file_sys_path).upper() version = gpo_version(lp, path) if version != store.get_int(guid): log.info('GPO %s has changed' % guid) changed_gpos.append(gpo_obj) gp_db.state(GPOSTATE.APPLY) store.start() for ext in gp_extensions: try: ext = ext(lp, creds, username, store) if target == 'Computer': ext.process_group_policy(del_gpos, changed_gpos) else: drop_privileges(username, ext.process_group_policy, del_gpos, changed_gpos) except Exception as e: log.error('Failed to apply extension %s' % str(ext)) _, _, tb = sys.exc_info() filename, line_number, _, _ = traceback.extract_tb(tb)[-1] log.error('%s:%d: %s: %s' % (filename, line_number, type(e).__name__, str(e))) continue for gpo_obj in gpos: if not gpo_obj.file_sys_path: continue guid = gpo_obj.name path = check_safe_path(gpo_obj.file_sys_path).upper() version = gpo_version(lp, path) store.store(guid, '%i' % version) store.commit() def unapply_gp(lp, creds, store, gp_extensions, username, target): gp_db = store.get_gplog(username) gp_db.state(GPOSTATE.UNAPPLY) # Treat all applied gpos as deleted del_gpos = gp_db.get_applied_settings(gp_db.get_applied_guids()) store.start() for ext in gp_extensions: try: ext = ext(lp, creds, username, store) if target == 'Computer': ext.process_group_policy(del_gpos, []) else: drop_privileges(username, ext.process_group_policy, del_gpos, []) except Exception as e: log.error('Failed to unapply extension %s' % str(ext)) log.error('Message was: ' + str(e)) continue store.commit() def __rsop_vals(vals, level=4): if type(vals) == dict: ret = [' '*level + '[ %s ] = %s' % (k, __rsop_vals(v, level+2)) for k, v in vals.items()] return '\n' + '\n'.join(ret) elif type(vals) == list: ret = [' '*level + '[ %s ]' % __rsop_vals(v, level+2) for v in vals] return '\n' + '\n'.join(ret) else: if isinstance(vals, numbers.Number): return ' '*(level+2) + str(vals) else: return ' '*(level+2) + get_string(vals) def rsop(lp, creds, store, gp_extensions, username, target): dc_hostname = get_dc_hostname(creds, lp) gpos = get_gpo_list(dc_hostname, creds, lp, username) check_refresh_gpo_list(dc_hostname, lp, creds, gpos) print('Resultant Set of Policy') print('%s Policy\n' % target) term_width = shutil.get_terminal_size(fallback=(120, 50))[0] for gpo_obj in gpos: if gpo_obj.display_name.strip() == 'Local Policy': continue # We never apply local policy print('GPO: %s' % gpo_obj.display_name) print('='*term_width) for ext in gp_extensions: ext = ext(lp, creds, username, store) cse_name_m = re.findall(r"'([\w\.]+)'", str(type(ext))) if len(cse_name_m) > 0: cse_name = cse_name_m[-1].split('.')[-1] else: cse_name = ext.__module__.split('.')[-1] print(' CSE: %s' % cse_name) print(' ' + ('-'*int(term_width/2))) for section, settings in ext.rsop(gpo_obj).items(): print(' Policy Type: %s' % section) print(' ' + ('-'*int(term_width/2))) print(__rsop_vals(settings).lstrip('\n')) print(' ' + ('-'*int(term_width/2))) print(' ' + ('-'*int(term_width/2))) print('%s\n' % ('='*term_width)) def parse_gpext_conf(smb_conf): from samba.samba3 import param as s3param lp = s3param.get_context() if smb_conf is not None: lp.load(smb_conf) else: lp.load_default() ext_conf = lp.state_path('gpext.conf') parser = ConfigParser(interpolation=None) parser.read(ext_conf) return lp, parser def atomic_write_conf(lp, parser): ext_conf = lp.state_path('gpext.conf') with NamedTemporaryFile(mode="w+", delete=False, dir=os.path.dirname(ext_conf)) as f: parser.write(f) os.rename(f.name, ext_conf) def check_guid(guid): # Check for valid guid with curly braces if guid[0] != '{' or guid[-1] != '}' or len(guid) != 38: return False try: UUID(guid, version=4) except ValueError: return False return True def register_gp_extension(guid, name, path, smb_conf=None, machine=True, user=True): # Check that the module exists if not os.path.exists(path): return False if not check_guid(guid): return False lp, parser = parse_gpext_conf(smb_conf) if guid not in parser.sections(): parser.add_section(guid) parser.set(guid, 'DllName', path) parser.set(guid, 'ProcessGroupPolicy', name) parser.set(guid, 'NoMachinePolicy', "0" if machine else "1") parser.set(guid, 'NoUserPolicy', "0" if user else "1") atomic_write_conf(lp, parser) return True def list_gp_extensions(smb_conf=None): _, parser = parse_gpext_conf(smb_conf) results = {} for guid in parser.sections(): results[guid] = {} results[guid]['DllName'] = parser.get(guid, 'DllName') results[guid]['ProcessGroupPolicy'] = \ parser.get(guid, 'ProcessGroupPolicy') results[guid]['MachinePolicy'] = \ not int(parser.get(guid, 'NoMachinePolicy')) results[guid]['UserPolicy'] = not int(parser.get(guid, 'NoUserPolicy')) return results def unregister_gp_extension(guid, smb_conf=None): if not check_guid(guid): return False lp, parser = parse_gpext_conf(smb_conf) if guid in parser.sections(): parser.remove_section(guid) atomic_write_conf(lp, parser) return True def set_privileges(username, uid, gid): """ Set current process privileges """ os.setegid(gid) os.seteuid(uid) def drop_privileges(username, func, *args): """ Run supplied function with privileges for specified username. """ current_uid = os.getuid() if not current_uid == 0: raise Exception('Not enough permissions to drop privileges') user_uid = pwd.getpwnam(username).pw_uid user_gid = pwd.getpwnam(username).pw_gid # Drop privileges set_privileges(username, user_uid, user_gid) # We need to catch exception in order to be able to restore # privileges later in this function out = None exc = None try: out = func(*args) except Exception as e: exc = e # Restore privileges set_privileges('root', current_uid, 0) if exc: raise exc return out def expand_pref_variables(text, gpt_path, lp, username=None): utc_dt = datetime.utcnow() dt = datetime.now() cache_path = lp.cache_path(os.path.join('gpo_cache')) # These are all the possible preference variables that MS supports. The # variables set to 'None' here are currently unsupported by Samba, and will # prevent the individual policy from applying. variables = { 'AppDataDir': os.path.expanduser('~/.config'), 'BinaryComputerSid': None, 'BinaryUserSid': None, 'CommonAppdataDir': None, 'CommonDesktopDir': None, 'CommonFavoritesDir': None, 'CommonProgramsDir': None, 'CommonStartUpDir': None, 'ComputerName': lp.get('netbios name'), 'CurrentProccessId': None, 'CurrentThreadId': None, 'DateTime': utc_dt.strftime('%Y-%m-%d %H:%M:%S UTC'), 'DateTimeEx': str(utc_dt), 'DesktopDir': os.path.expanduser('~/Desktop'), 'DomainName': lp.get('realm'), 'FavoritesDir': None, 'GphPath': None, 'GptPath': os.path.join(cache_path, check_safe_path(gpt_path).upper()), 'GroupPolicyVersion': None, 'LastDriveMapped': None, 'LastError': None, 'LastErrorText': None, 'LdapComputerSid': None, 'LdapUserSid': None, 'LocalTime': dt.strftime('%H:%M:%S'), 'LocalTimeEx': dt.strftime('%H:%M:%S.%f'), 'LogonDomain': lp.get('realm'), 'LogonServer': None, 'LogonUser': username, 'LogonUserSid': None, 'MacAddress': None, 'NetPlacesDir': None, 'OsVersion': None, 'ProgramFilesDir': None, 'ProgramsDir': None, 'RecentDocumentsDir': None, 'ResultCode': None, 'ResultText': None, 'ReversedComputerSid': None, 'ReversedUserSid': None, 'SendToDir': None, 'StartMenuDir': None, 'StartUpDir': None, 'SystemDir': None, 'SystemDrive': '/', 'TempDir': '/tmp', 'TimeStamp': str(datetime.timestamp(dt)), 'TraceFile': None, 'WindowsDir': None } for exp_var, val in variables.items(): exp_var_fmt = '%%%s%%' % exp_var if exp_var_fmt in text: if val is None: raise NameError('Expansion variable %s is undefined' % exp_var) text = text.replace(exp_var_fmt, val) return text