# Authors: # Alexander Bokovoy # # Copyright (C) 2011 Red Hat # see file 'COPYING' for use and warranty information # # Portions (C) Andrew Tridgell, Andrew Bartlett # # 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 . # Make sure we only run this module at the server where samba4-python # package is installed to avoid issues with unavailable modules from ipalib.plugins.baseldap import * from ipalib import api, Str, Password, DefaultFrom, _, ngettext, Object from ipalib.parameters import Enum from ipalib import Command from ipalib import errors from ipapython import ipautil from ipapython.ipa_log_manager import * from ipapython.dn import DN from ipaserver.install import installutils import os, string, struct, copy import uuid from samba import param from samba import credentials from samba.dcerpc import security, lsa, drsblobs, nbt, netlogon from samba.ndr import ndr_pack from samba import net import samba import random from Crypto.Cipher import ARC4 try: from ldap.controls import RequestControl as LDAPControl #pylint: disable=F0401 except ImportError: from ldap.controls import LDAPControl as LDAPControl #pylint: disable=F0401 import ldap as _ldap from ipaserver.ipaldap import IPAdmin from ipalib.session import krbccache_dir, krbccache_prefix from dns import resolver, rdatatype from dns.exception import DNSException __doc__ = _(""" Classes to manage trust joins using DCE-RPC calls The code in this module relies heavily on samba4-python package and Samba4 python bindings. """) access_denied_error = errors.ACIError(info=_('CIFS server denied your credentials')) dcerpc_error_codes = { -1073741823: errors.RemoteRetrieveError(reason=_('communication with CIFS server was unsuccessful')), -1073741790: access_denied_error, -1073741715: access_denied_error, -1073741614: access_denied_error, -1073741603: errors.ValidationError(name=_('AD domain controller'), error=_('unsupported functional level')), } dcerpc_error_messages = { "NT_STATUS_OBJECT_NAME_NOT_FOUND": errors.NotFound(reason=_('Cannot find specified domain or server name')), "NT_STATUS_INVALID_PARAMETER_MIX": errors.RequirementError(name=_('At least the domain or IP address should be specified')), } def assess_dcerpc_exception(num=None,message=None): """ Takes error returned by Samba bindings and converts it into an IPA error class. """ if num and num in dcerpc_error_codes: return dcerpc_error_codes[num] if message and message in dcerpc_error_messages: return dcerpc_error_messages[message] reason = _('''CIFS server communication error: code "%(num)s", message "%(message)s" (both may be "None")''') % dict(num=num, message=message) return errors.RemoteRetrieveError(reason=reason) class ExtendedDNControl(LDAPControl): # This class attempts to implement LDAP control that would work # with both python-ldap 2.4.x and 2.3.x, thus there is mix of properties # from both worlds and encodeControlValue has default parameter def __init__(self): self.controlValue = 1 self.controlType = "1.2.840.113556.1.4.529" self.criticality = False self.integerValue = 1 def encodeControlValue(self, value=None): return '0\x03\x02\x01\x01' class DomainValidator(object): ATTR_FLATNAME = 'ipantflatname' ATTR_SID = 'ipantsecurityidentifier' ATTR_TRUSTED_SID = 'ipanttrusteddomainsid' ATTR_TRUST_PARTNER = 'ipanttrustpartner' ATTR_TRUST_AUTHOUT = 'ipanttrustauthoutgoing' def __init__(self, api): self.api = api self.ldap = self.api.Backend.ldap2 self.domain = None self.flatname = None self.dn = None self.sid = None self._domains = None self._info = dict() self._creds = None self._parm = None def is_configured(self): cn_trust_local = DN(('cn', self.api.env.domain), self.api.env.container_cifsdomains, self.api.env.basedn) try: (dn, entry_attrs) = self.ldap.get_entry(cn_trust_local, [self.ATTR_FLATNAME, self.ATTR_SID]) self.flatname = entry_attrs[self.ATTR_FLATNAME][0] self.sid = entry_attrs[self.ATTR_SID][0] self.dn = dn self.domain = self.api.env.domain except errors.NotFound, e: return False return True def get_trusted_domains(self): """Returns dict of trusted domain tuples (flatname, sid, trust_auth_outgoing), keyed by domain name""" cn_trust = DN(('cn', 'ad'), self.api.env.container_trusts, self.api.env.basedn) try: search_kw = {'objectClass': 'ipaNTTrustedDomain'} filter = self.ldap.make_filter(search_kw, rules=self.ldap.MATCH_ALL) (entries, truncated) = self.ldap.find_entries(filter=filter, base_dn=cn_trust, attrs_list=[self.ATTR_TRUSTED_SID, self.ATTR_FLATNAME, self.ATTR_TRUST_PARTNER, self.ATTR_TRUST_AUTHOUT]) result = dict() for entry in entries: result[entry[1][self.ATTR_TRUST_PARTNER][0]] = (entry[1][self.ATTR_FLATNAME][0].lower(), security.dom_sid(entry[1][self.ATTR_TRUSTED_SID][0]), entry[1][self.ATTR_TRUST_AUTHOUT][0]) return result except errors.NotFound, e: return [] def is_trusted_sid_valid(self, sid): if not self.domain: # our domain is not configured or self.is_configured() never run # reject SIDs as we can't check correctness of them return False # Parse sid string to see if it is really in a SID format try: test_sid = security.dom_sid(sid) except TypeError, e: return False # At this point we have SID_NT_AUTHORITY family SID and really need to # check it against prefixes of domain SIDs we trust to if not self._domains: self._domains = self.get_trusted_domains() if len(self._domains) == 0: # Our domain is configured but no trusted domains are configured # This means we can't check the correctness of a trusted domain SIDs return False # We have non-zero list of trusted domains and have to go through them # one by one and check their sids as prefixes test_sid_subauths = test_sid.sub_auths for domain in self._domains: domsid = self._domains[domain][1] sub_auths = domsid.sub_auths num_auths = min(test_sid.num_auths, domsid.num_auths) if test_sid_subauths[:num_auths] == sub_auths[:num_auths]: return True return False def normalize_name(self, name): result = dict() components = name.split('@') if len(components) == 2: result['domain'] = unicode(components[1]).lower() result['name'] = unicode(components[0]).lower() else: components = name.split('\\') if len(components) == 2: result['flatname'] = unicode(components[0]).lower() result['name'] = unicode(components[1]).lower() else: result['name'] = unicode(name).lower() return result def get_sid_trusted_domain_object(self, object_name): """Returns SID for the trusted domain object (user or group only)""" if not self.domain: # our domain is not configured or self.is_configured() never run return None if not self._domains: self._domains = self.get_trusted_domains() if len(self._domains) == 0: # Our domain is configured but no trusted domains are configured return None components = self.normalize_name(object_name) if not ('domain' in components or 'flatname' in components): # No domain or realm specified, ambiguous search return False entry = None if 'domain' in components and components['domain'] in self._domains: # Now we have a name to check against our list of trusted domains entry = self.resolve_against_gc(components['domain'], components['name']) elif 'flatname' in components: # Flatname was specified, traverse through the list of trusted # domains first to find the proper one for domain in self._domains: if self._domains[domain][0] == components['flatname']: entry = self.resolve_against_gc(domain, components['name']) if entry: break if entry: try: test_sid = security.dom_sid(entry) return unicode(test_sid) except TypeError, e: return False return False def __sid_to_str(self, sid): """ Converts binary SID to string representation Returns unicode string """ sid_rev_num = ord(sid[0]) number_sub_id = ord(sid[1]) ia = struct.unpack('!Q','\x00\x00'+sid[2:8])[0] subs = [ struct.unpack(', we use krbccache_prefix++ so there is no clash Returns tuple (ccache name, principal) where (None, None) signifes an error on ccache initialization """ ccache_name = os.path.join(krbccache_dir, "%sTD%s" % (krbccache_prefix, info['name'][0])) principal = '%s$@%s' % (self.flatname, info['dns_domain'].upper()) (stdout, stderr, returncode) = ipautil.run(['/usr/bin/kinit', principal], env={'KRB5CCNAME':ccache_name}, stdin=password, raiseonerr=False) if returncode == 0: return (ccache_name, principal) else: return (None, None) def resolve_against_gc(self, domain, name): """ Resolves `name' against trusted domain `domain' using Global Catalog Returns SID of the `name' or None """ entry = None sid = None info = self.__retrieve_trusted_domain_gc_list(domain) if not info: return None for (host, port) in info['gc']: entry = self.__resolve_against_gc(info, host, port, name) if entry: break if entry: l = len(entry) if l > 2: # Treat non-unique entries as invalid return None sid = self.__sid_to_str(entry[0][1]['objectSid'][0]) return sid def __resolve_against_gc(self, info, host, port, name): """ Actual resolution against LDAP server, using SASL GSSAPI authentication Returns LDAP result or None """ conn = IPAdmin(host=host, port=port) auth = self.__extract_trusted_auth(info) if auth: (ccache_name, principal) = self.__kinit_as_trusted_account(info, auth) if ccache_name: cb_info = dict() # pass empty dict, SASL GSSAPI is able to get all from the ccache sasl_auth = _ldap.sasl.sasl(cb_info,'GSSAPI') old_ccache = os.environ.get('KRB5CCNAME') os.environ["KRB5CCNAME"] = ccache_name # OPT_X_SASL_NOCANON is used to avoid hard requirement for PTR # records pointing back to the same host name conn.set_option(_ldap.OPT_X_SASL_NOCANON, _ldap.OPT_ON) conn.sasl_interactive_bind_s(None, sasl_auth) base = DN(*map(lambda p: ('dc', p), info['dns_domain'].split('.'))) # We don't use conn.getEntry() because it will attempt to fetch schema from GC and that will fail filterstr = conn.encode('(&(sAMAccountName=%(name)s)(|(objectClass=user)(objectClass=group)))' % dict(name=name)) attrlist = conn.encode(['sAMAccountName', 'sAMAccountType', 'objectSid', 'groupType', 'description']) entry = conn.conn.search_s(str(base), _ldap.SCOPE_SUBTREE, filterstr, attrlist, 0) os.environ["KRB5CCNAME"] = old_ccache return entry def __retrieve_trusted_domain_gc_list(self, domain): """ Retrieves domain information and preferred GC list Returns dictionary with following keys name -- NetBIOS name of the trusted domain dns_domain -- DNS name of the trusted domain auth -- encrypted credentials for trusted domain account gc -- array of tuples (server, port) for Global Catalog """ if domain in self._info: return self._info[domain] if not self._creds: self._parm = param.LoadParm() self._parm.load(os.path.join(ipautil.SHARE_DIR,"smb.conf.empty")) self._parm.set('netbios name', self.flatname) self._creds = credentials.Credentials() self._creds.set_kerberos_state(credentials.MUST_USE_KERBEROS) self._creds.guess(self._parm) self._creds.set_workstation(self.flatname) netrc = net.Net(creds=self._creds, lp=self._parm) finddc_error = None result = None try: result = netrc.finddc(domain=domain, flags=nbt.NBT_SERVER_LDAP | nbt.NBT_SERVER_GC) except RuntimeError, e: finddc_error = e info = dict() info['auth'] = self._domains[domain][2] servers = [] if result: info['name'] = unicode(result.domain_name) info['dns_domain'] = unicode(result.dns_domain) servers = [(unicode(result.pdc_dns_name), 3268)] else: info['name'] = self._domains[domain] info['dns_domain'] = domain # Retrieve GC servers list gc_name = '_gc._tcp.%s.' % info['dns_domain'] try: answers = resolver.query(gc_name, rdatatype.SRV) except DNSException, e: answers = [] for answer in answers: server = str(answer.target).rstrip(".") servers.append((server, answer.port)) info['gc'] = servers # Both methods should not fail at the same time if finddc_error and len(info['gc']) == 0: raise assess_dcerpc_exception(message=str(finddc_error)) self._info[domain] = info return info class TrustDomainInstance(object): def __init__(self, hostname, creds=None): self.parm = param.LoadParm() self.parm.load(os.path.join(ipautil.SHARE_DIR,"smb.conf.empty")) if len(hostname) > 0: self.parm.set('netbios name', hostname) self.creds = creds self.hostname = hostname self.info = {} self._pipe = None self._policy_handle = None self.read_only = False def __gen_lsa_connection(self, binding): if self.creds is None: raise errors.RequirementError(name=_('CIFS credentials object')) try: result = lsa.lsarpc(binding, self.parm, self.creds) return result except RuntimeError, (num, message): raise assess_dcerpc_exception(num=num, message=message) def __init_lsa_pipe(self, remote_host): """ Try to initialize connection to the LSA pipe at remote host. This method tries consequently all possible transport options and selects one that works. See __gen_lsa_bindings() for details. The actual result may depend on details of existing credentials. For example, using signing causes NO_SESSION_KEY with Win2K8 and using kerberos against Samba with signing does not work. """ # short-cut: if LSA pipe is initialized, skip completely if self._pipe: return attempts = 0 bindings = self.__gen_lsa_bindings(remote_host) for binding in bindings: try: self._pipe = self.__gen_lsa_connection(binding) if self._pipe: break except errors.ACIError, e: attempts = attempts + 1 if self._pipe is None and attempts == len(bindings): raise errors.ACIError( info=_('CIFS server %(host)s denied your credentials') % dict(host=remote_host)) if self._pipe is None: raise errors.RemoteRetrieveError( reason=_('Cannot establish LSA connection to %(host)s. Is CIFS server running?') % dict(host=remote_host)) self.binding = binding def __gen_lsa_bindings(self, remote_host): """ There are multiple transports to issue LSA calls. However, depending on a system in use they may be blocked by local operating system policies. Generate all we can use. __init_lsa_pipe() will try them one by one until there is one working. We try NCACN_NP before NCACN_IP_TCP and signed sessions before unsigned. """ transports = (u'ncacn_np', u'ncacn_ip_tcp') options = ( u',', u'') binding_template=lambda x,y,z: u'%s:%s[%s]' % (x, y, z) return [binding_template(t, remote_host, o) for t in transports for o in options] def retrieve_anonymously(self, remote_host, discover_srv=False): """ When retrieving DC information anonymously, we can't get SID of the domain """ netrc = net.Net(creds=self.creds, lp=self.parm) try: if discover_srv: result = netrc.finddc(domain=remote_host, flags=nbt.NBT_SERVER_LDAP | nbt.NBT_SERVER_DS) else: result = netrc.finddc(address=remote_host, flags=nbt.NBT_SERVER_LDAP | nbt.NBT_SERVER_DS) except RuntimeError, e: raise assess_dcerpc_exception(message=str(e)) if not result: return False self.info['name'] = unicode(result.domain_name) self.info['dns_domain'] = unicode(result.dns_domain) self.info['dns_forest'] = unicode(result.forest) self.info['guid'] = unicode(result.domain_uuid) self.info['dc'] = unicode(result.pdc_dns_name) # Netlogon response doesn't contain SID of the domain. # We need to do rootDSE search with LDAP_SERVER_EXTENDED_DN_OID control to reveal the SID ldap_uri = 'ldap://%s' % (result.pdc_dns_name) conn = _ldap.initialize(ldap_uri) conn.set_option(_ldap.OPT_SERVER_CONTROLS, [ExtendedDNControl()]) result = None try: (objtype, res) = conn.search_s('', _ldap.SCOPE_BASE)[0] result = res['defaultNamingContext'][0] self.info['dns_hostname'] = res['dnsHostName'][0] except _ldap.LDAPError, e: root_logger.error( "LDAP error when connecting to %(host)s: %(error)s" % dict(host=unicode(result.pdc_name), error=str(e))) if result: self.info['sid'] = self.parse_naming_context(result) return True def parse_naming_context(self, context): naming_ref = re.compile('.*.*') return naming_ref.match(context).group(1) def retrieve(self, remote_host): self.__init_lsa_pipe(remote_host) objectAttribute = lsa.ObjectAttribute() objectAttribute.sec_qos = lsa.QosInfo() try: self._policy_handle = self._pipe.OpenPolicy2(u"", objectAttribute, security.SEC_FLAG_MAXIMUM_ALLOWED) result = self._pipe.QueryInfoPolicy2(self._policy_handle, lsa.LSA_POLICY_INFO_DNS) except RuntimeError, (num, message): raise assess_dcerpc_exception(num=num, message=message) self.info['name'] = unicode(result.name.string) self.info['dns_domain'] = unicode(result.dns_domain.string) self.info['dns_forest'] = unicode(result.dns_forest.string) self.info['guid'] = unicode(result.domain_guid) self.info['sid'] = unicode(result.sid) self.info['dc'] = remote_host def generate_auth(self, trustdom_secret): def arcfour_encrypt(key, data): c = ARC4.new(key) return c.encrypt(data) def string_to_array(what): blob = [0] * len(what) for i in range(len(what)): blob[i] = ord(what[i]) return blob password_blob = string_to_array(trustdom_secret.encode('utf-16-le')) clear_value = drsblobs.AuthInfoClear() clear_value.size = len(password_blob) clear_value.password = password_blob clear_authentication_information = drsblobs.AuthenticationInformation() clear_authentication_information.LastUpdateTime = samba.unix2nttime(int(time.time())) clear_authentication_information.AuthType = lsa.TRUST_AUTH_TYPE_CLEAR clear_authentication_information.AuthInfo = clear_value authentication_information_array = drsblobs.AuthenticationInformationArray() authentication_information_array.count = 1 authentication_information_array.array = [clear_authentication_information] outgoing = drsblobs.trustAuthInOutBlob() outgoing.count = 1 outgoing.current = authentication_information_array confounder = [3]*512 for i in range(512): confounder[i] = random.randint(0, 255) trustpass = drsblobs.trustDomainPasswords() trustpass.confounder = confounder trustpass.outgoing = outgoing trustpass.incoming = outgoing trustpass_blob = ndr_pack(trustpass) encrypted_trustpass = arcfour_encrypt(self._pipe.session_key, trustpass_blob) auth_blob = lsa.DATA_BUF2() auth_blob.size = len(encrypted_trustpass) auth_blob.data = string_to_array(encrypted_trustpass) auth_info = lsa.TrustDomainInfoAuthInfoInternal() auth_info.auth_blob = auth_blob self.auth_info = auth_info def establish_trust(self, another_domain, trustdom_secret): """ Establishes trust between our and another domain Input: another_domain -- instance of TrustDomainInstance, initialized with #retrieve call trustdom_secret -- shared secred used for the trust """ self.generate_auth(trustdom_secret) info = lsa.TrustDomainInfoInfoEx() info.domain_name.string = another_domain.info['dns_domain'] info.netbios_name.string = another_domain.info['name'] info.sid = security.dom_sid(another_domain.info['sid']) info.trust_direction = lsa.LSA_TRUST_DIRECTION_INBOUND | lsa.LSA_TRUST_DIRECTION_OUTBOUND info.trust_type = lsa.LSA_TRUST_TYPE_UPLEVEL info.trust_attributes = lsa.LSA_TRUST_ATTRIBUTE_FOREST_TRANSITIVE try: dname = lsa.String() dname.string = another_domain.info['dns_domain'] res = self._pipe.QueryTrustedDomainInfoByName(self._policy_handle, dname, lsa.LSA_TRUSTED_DOMAIN_INFO_FULL_INFO) self._pipe.DeleteTrustedDomain(self._policy_handle, res.info_ex.sid) except RuntimeError, e: pass try: trustdom_handle = self._pipe.CreateTrustedDomainEx2(self._policy_handle, info, self.auth_info, security.SEC_STD_DELETE) except RuntimeError, (num, message): raise assess_dcerpc_exception(num=num, message=message) try: infoclass = lsa.TrustDomainInfoSupportedEncTypes() infoclass.enc_types = security.KERB_ENCTYPE_RC4_HMAC_MD5 infoclass.enc_types |= security.KERB_ENCTYPE_AES128_CTS_HMAC_SHA1_96 infoclass.enc_types |= security.KERB_ENCTYPE_AES256_CTS_HMAC_SHA1_96 self._pipe.SetInformationTrustedDomain(trustdom_handle, lsa.LSA_TRUSTED_DOMAIN_SUPPORTED_ENCRYPTION_TYPES, infoclass) except RuntimeError, e: pass def verify_trust(self, another_domain): def retrieve_netlogon_info_2(domain, function_code, data): try: netr_pipe = netlogon.netlogon(domain.binding, domain.parm, domain.creds) result = netr_pipe.netr_LogonControl2Ex(logon_server=None, function_code=function_code, level=2, data=data ) return result except RuntimeError, (num, message): raise assess_dcerpc_exception(num=num, message=message) result = retrieve_netlogon_info_2(self, netlogon.NETLOGON_CONTROL_TC_VERIFY, another_domain.info['dns_domain']) if (result and (result.flags and netlogon.NETLOGON_VERIFY_STATUS_RETURNED)): # netr_LogonControl2Ex() returns non-None result only if overall call # result was WERR_OK which means verification was correct. # We only check that it was indeed status for verification process return True return False class TrustDomainJoins(object): def __init__(self, api): self.api = api self.local_domain = None self.remote_domain = None domain_validator = DomainValidator(api) self.configured = domain_validator.is_configured() if self.configured: self.local_flatname = domain_validator.flatname self.local_dn = domain_validator.dn self.__populate_local_domain() def __populate_local_domain(self): # Initialize local domain info using kerberos only ld = TrustDomainInstance(self.local_flatname) ld.creds = credentials.Credentials() ld.creds.set_kerberos_state(credentials.MUST_USE_KERBEROS) ld.creds.guess(ld.parm) ld.creds.set_workstation(ld.hostname) ld.retrieve(installutils.get_fqdn()) self.local_domain = ld def __populate_remote_domain(self, realm, realm_server=None, realm_admin=None, realm_passwd=None): def get_instance(self): # Fetch data from foreign domain using password only rd = TrustDomainInstance('') rd.parm.set('workgroup', self.local_domain.info['name']) rd.creds = credentials.Credentials() rd.creds.set_kerberos_state(credentials.DONT_USE_KERBEROS) rd.creds.guess(rd.parm) return rd rd = get_instance(self) rd.creds.set_anonymous() rd.creds.set_workstation(self.local_domain.hostname) if realm_server is None: rd.retrieve_anonymously(realm, discover_srv=True) else: rd.retrieve_anonymously(realm_server, discover_srv=False) rd.read_only = True if realm_admin and realm_passwd: if 'name' in rd.info: names = realm_admin.split('\\') if len(names) > 1: # realm admin is in DOMAIN\user format # strip DOMAIN part as we'll enforce the one discovered realm_admin = names[-1] auth_string = u"%s\%s%%%s" % (rd.info['name'], realm_admin, realm_passwd) td = get_instance(self) td.creds.parse_string(auth_string) td.creds.set_workstation(self.local_domain.hostname) if realm_server is None: # we must have rd.info['dns_hostname'] then, part of anonymous discovery td.retrieve(rd.info['dns_hostname']) else: td.retrieve(realm_server) td.read_only = False self.remote_domain = td return # Otherwise, use anonymously obtained data self.remote_domain = rd def join_ad_full_credentials(self, realm, realm_server, realm_admin, realm_passwd): if not self.configured: return None self.__populate_remote_domain(realm, realm_server, realm_admin, realm_passwd) if not self.remote_domain.read_only: trustdom_pass = samba.generate_random_password(128, 128) self.remote_domain.establish_trust(self.local_domain, trustdom_pass) self.local_domain.establish_trust(self.remote_domain, trustdom_pass) result = self.remote_domain.verify_trust(self.local_domain) return dict(local=self.local_domain, remote=self.remote_domain, verified=result) return None def join_ad_ipa_half(self, realm, realm_server, trustdom_passwd): if not self.configured: return None self.__populate_remote_domain(realm, realm_server, realm_passwd=None) self.local_domain.establish_trust(self.remote_domain, trustdom_passwd) return dict(local=self.local_domain, remote=self.remote_domain, verified=False)