#!/usr/bin/env python # -*- coding: utf-8 -*- # """Contains classes and functions that a SAML2.0 Identity provider (IdP) or attribute authority (AA) may use to conclude its tasks. """ import logging import os import importlib import dbm import shelve import six import threading import saml2.cryptography.symmetric from saml2 import saml from saml2 import element_to_extension_element from saml2 import class_name from saml2 import BINDING_HTTP_REDIRECT from saml2.argtree import add_path, is_set from saml2.entity import Entity from saml2.eptid import Eptid from saml2.eptid import EptidShelve from saml2.samlp import NameIDMappingResponse from saml2.sdb import SessionStorage from saml2.schema import soapenv from saml2.request import AuthnRequest from saml2.request import AssertionIDRequest from saml2.request import AttributeQuery from saml2.request import NameIDMappingRequest from saml2.request import AuthzDecisionQuery from saml2.request import AuthnQuery from saml2.s_utils import MissingValue from saml2.s_utils import rndstr from saml2.s_utils import Unknown from saml2.sigver import pre_signature_part from saml2.sigver import signed_instance_factory from saml2.sigver import CertificateError from saml2.assertion import Assertion from saml2.assertion import Policy from saml2.assertion import restriction_from_attribute_spec from saml2.assertion import filter_attribute_value_assertions from saml2.ident import IdentDB, decode from saml2.profile import ecp logger = logging.getLogger(__name__) AUTHN_DICT_MAP = { "decl": "authn_decl", "authn_auth": "authn_auth", "class_ref": "authn_class", "authn_instant": "authn_instant", "subject_locality": "subject_locality" } def _shelve_compat(name, *args, **kwargs): try: return shelve.open(name, *args, **kwargs) except dbm.error[0]: # Python 3 whichdb needs to try .db to determine type if name.endswith('.db'): name = name.rsplit('.db', 1)[0] return shelve.open(name, *args, **kwargs) else: raise class Server(Entity): """ A class that does things that IdPs or AAs do """ def __init__( self, config_file="", config=None, cache=None, stype="idp", symkey="", msg_cb=None, ): Entity.__init__(self, stype, config, config_file, msg_cb=msg_cb) self.eptid = None self.init_config(stype) self.cache = cache self.ticket = {} self.session_db = self.choose_session_storage() if symkey: self.symkey = symkey.encode() else: self.symkey = saml2.cryptography.symmetric.Default.generate_key() self.seed = rndstr() self.lock = threading.Lock() def getvalid_certificate_str(self): if self.sec.cert_handler is not None: return self.sec.cert_handler._last_validated_cert return None def support_AssertionIDRequest(self): return True def support_AuthnQuery(self): return True def choose_session_storage(self): _spec = self.config.getattr("session_storage", "idp") if not _spec: return SessionStorage() elif isinstance(_spec, six.string_types): if _spec.lower() == "memory": return SessionStorage() else: # Should be tuple typ, data = _spec if typ.lower() == "mongodb": from saml2.mongo_store import SessionStorageMDB return SessionStorageMDB(database=data, collection="session") raise NotImplementedError("No such storage type implemented") def init_config(self, stype="idp"): """ Remaining init of the server configuration :param stype: The type of Server ("idp"/"aa") """ if stype == "aa": return # subject information is stored in a database # default database is in memory which is OK in some setups dbspec = self.config.getattr("subject_data", "idp") idb = None typ = "" if not dbspec: idb = {} elif isinstance(dbspec, six.string_types): idb = _shelve_compat(dbspec, writeback=True, protocol=2) else: # database spec is a a 2-tuple (type, address) # print(>> sys.stderr, "DBSPEC: %s" % (dbspec,)) (typ, addr) = dbspec if typ == "shelve": idb = _shelve_compat(addr, writeback=True, protocol=2) elif typ == "memcached": import memcache idb = memcache.Client(addr) elif typ == "dict": # in-memory dictionary idb = {} elif typ == "mongodb": from saml2.mongo_store import IdentMDB self.ident = IdentMDB(database=addr, collection="ident") elif typ == "identdb": mod, clas = addr.rsplit('.', 1) mod = importlib.import_module(mod) self.ident = getattr(mod, clas)() if typ == "mongodb" or typ == "identdb": pass elif idb is not None: self.ident = IdentDB(idb) elif dbspec: raise Exception("Couldn't open identity database: %s" % (dbspec,)) try: _domain = self.config.getattr("domain", "idp") if _domain: self.ident.domain = _domain self.ident.name_qualifier = self.config.entityid dbspec = self.config.getattr("edu_person_targeted_id", "idp") if not dbspec: pass else: typ = dbspec[0] addr = dbspec[1] secret = dbspec[2] if typ == "shelve": self.eptid = EptidShelve(secret, addr) elif typ == "mongodb": from saml2.mongo_store import EptidMDB self.eptid = EptidMDB(secret, database=addr, collection="eptid") else: self.eptid = Eptid(secret) except Exception: self.ident.close() raise def wants(self, sp_entity_id, index=None): """ Returns what attributes the SP requires and which are optional if any such demands are registered in the Metadata. :param sp_entity_id: The entity id of the SP :param index: which of the attribute consumer services its all about if index == None then all attribute consumer services are clumped together. :return: 2-tuple, list of required and list of optional attributes """ return self.metadata.attribute_requirement(sp_entity_id, index) def verify_assertion_consumer_service(self, request): _acs = request.assertion_consumer_service_url _aci = request.assertion_consumer_service_index _binding = request.protocol_binding _eid = request.issuer.text if _acs: # look up acs in for that binding in the metadata given the issuer # Assuming the format is entity for acs in self.metadata.assertion_consumer_service(_eid, _binding): if _acs == acs.text: return True elif _aci: for acs in self.metadata.assertion_consumer_service(_eid, _binding): if _aci == acs.index: return True return False # ------------------------------------------------------------------------- def parse_authn_request(self, enc_request, binding=BINDING_HTTP_REDIRECT): """Parse a Authentication Request :param enc_request: The request in its transport format :param binding: Which binding that was used to transport the message to this entity. :return: A request instance """ return self._parse_request(enc_request, AuthnRequest, "single_sign_on_service", binding) def parse_attribute_query(self, xml_string, binding): """ Parse an attribute query :param xml_string: The Attribute Query as an XML string :param binding: Which binding that was used for the request :return: A query instance """ return self._parse_request(xml_string, AttributeQuery, "attribute_service", binding) def parse_authz_decision_query(self, xml_string, binding): """ Parse an authorization decision query :param xml_string: The Authz decision Query as an XML string :param binding: Which binding that was used when receiving this query :return: Query instance """ return self._parse_request(xml_string, AuthzDecisionQuery, "authz_service", binding) def parse_assertion_id_request(self, xml_string, binding): """ Parse an assertion id query :param xml_string: The AssertionIDRequest as an XML string :param binding: Which binding that was used when receiving this request :return: Query instance """ return self._parse_request(xml_string, AssertionIDRequest, "assertion_id_request_service", binding) def parse_authn_query(self, xml_string, binding): """ Parse an authn query :param xml_string: The AuthnQuery as an XML string :param binding: Which binding that was used when receiving this query :return: Query instance """ return self._parse_request(xml_string, AuthnQuery, "authn_query_service", binding) def parse_name_id_mapping_request(self, xml_string, binding): """ Parse a nameid mapping request :param xml_string: The NameIDMappingRequest as an XML string :param binding: Which binding that was used when receiving this request :return: Query instance """ return self._parse_request(xml_string, NameIDMappingRequest, "name_id_mapping_service", binding) @staticmethod def update_farg(in_response_to, consumer_url, farg=None): if not farg: farg = add_path( {}, ['assertion', 'subject', 'subject_confirmation', 'method', saml.SCM_BEARER]) add_path( farg['assertion']['subject']['subject_confirmation'], ['subject_confirmation_data', 'in_response_to', in_response_to]) add_path( farg['assertion']['subject']['subject_confirmation'], ['subject_confirmation_data', 'recipient', consumer_url]) else: if not is_set(farg, ['assertion', 'subject', 'subject_confirmation', 'method']): add_path(farg, ['assertion', 'subject', 'subject_confirmation', 'method', saml.SCM_BEARER]) if not is_set(farg, ['assertion', 'subject', 'subject_confirmation', 'subject_confirmation_data', 'in_response_to']): add_path(farg, ['assertion', 'subject', 'subject_confirmation', 'subject_confirmation_data', 'in_response_to', in_response_to]) if not is_set(farg, ['assertion', 'subject', 'subject_confirmation', 'subject_confirmation_data', 'recipient']): add_path(farg, ['assertion', 'subject', 'subject_confirmation', 'subject_confirmation_data', 'recipient', consumer_url]) return farg def setup_assertion( self, authn, sp_entity_id, in_response_to, consumer_url, name_id, policy, _issuer, authn_statement, identity, best_effort, sign_response, farg=None, session_not_on_or_after=None, sign_alg=None, digest_alg=None, **kwargs, ): """ Construct and return the Assertion :param authn: Authentication information :param sp_entity_id: :param in_response_to: The ID of the request this is an answer to :param consumer_url: The recipient of the assertion :param name_id: The NameID of the subject :param policy: Assertion policies :param _issuer: Issuer of the statement :param authn_statement: An AuthnStatement instance :param identity: Identity information about the Subject :param best_effort: Even if not the SPs demands can be met send a response. :param sign_response: Sign the response, only applicable if ErrorResponse :param kwargs: Extra keyword arguments :return: An Assertion instance """ ast = Assertion(identity) ast.acs = self.config.getattr("attribute_converters") if policy is None: policy = Policy(mds=self.metadata) try: ast.apply_policy(sp_entity_id, policy) except MissingValue as exc: if not best_effort: response = self.create_error_response( in_response_to, destination=consumer_url, info=exc, sign=sign_response, sign_alg=sign_alg, digest_alg=digest_alg, ) return str(response).split("\n") farg = self.update_farg(in_response_to, consumer_url, farg) if authn: # expected to be a dictionary # Would like to use dict comprehension but ... authn_args = dict( [(AUTHN_DICT_MAP[k], v) for k, v in authn.items() if k in AUTHN_DICT_MAP]) authn_args.update(kwargs) assertion = ast.construct( sp_entity_id, self.config.attribute_converters, policy, issuer=_issuer, farg=farg['assertion'], name_id=name_id, session_not_on_or_after=session_not_on_or_after, **authn_args) elif authn_statement: # Got a complete AuthnStatement assertion = ast.construct( sp_entity_id, self.config.attribute_converters, policy, issuer=_issuer, authn_statem=authn_statement, farg=farg['assertion'], name_id=name_id, **kwargs) else: assertion = ast.construct( sp_entity_id, self.config.attribute_converters, policy, issuer=_issuer, farg=farg['assertion'], name_id=name_id, session_not_on_or_after=session_not_on_or_after, **kwargs) return assertion # XXX DONE calls pre_signature_part # XXX calls _response def _authn_response( self, in_response_to, consumer_url, sp_entity_id, identity=None, name_id=None, status=None, authn=None, issuer=None, policy=None, sign_assertion=None, sign_response=None, best_effort=False, encrypt_assertion=False, encrypt_cert_advice=None, encrypt_cert_assertion=None, authn_statement=None, encrypt_assertion_self_contained=False, encrypted_advice_attributes=False, pefim=False, sign_alg=None, digest_alg=None, farg=None, session_not_on_or_after=None, ): """ Create a response. A layer of indirection. :param in_response_to: The session identifier of the request :param consumer_url: The URL which should receive the response :param sp_entity_id: The entity identifier of the SP :param identity: A dictionary with attributes and values that are expected to be the bases for the assertion in the response. :param name_id: The identifier of the subject :param status: The status of the response :param authn: A dictionary containing information about the authn context. :param issuer: The issuer of the response :param policy: :param sign_assertion: Whether the assertion should be signed or not :param sign_response: Whether the response should be signed or not :param best_effort: Even if not the SPs demands can be met send a response. :param encrypt_assertion: True if assertions should be encrypted. :param encrypt_assertion_self_contained: True if all encrypted assertions should have alla namespaces selfcontained. :param encrypted_advice_attributes: True if assertions in the advice element should be encrypted. :param encrypt_cert_advice: Certificate to be used for encryption of assertions in the advice element. :param encrypt_cert_assertion: Certificate to be used for encryption of assertions. :param authn_statement: Authentication statement. :param pefim: True if a response according to the PEFIM profile should be created. :param farg: Argument to pass on to the assertion constructor :return: A response instance """ if farg is None: assertion_args = {} # if identity: _issuer = self._issuer(issuer) # if encrypt_assertion and show_nameid: # tmp_name_id = name_id # name_id = None # name_id = None # tmp_authn = authn # authn = None # tmp_authn_statement = authn_statement # authn_statement = None if pefim: encrypted_advice_attributes = True encrypt_assertion_self_contained = True assertion_attributes = self.setup_assertion( None, sp_entity_id, None, None, None, policy, None, None, identity, best_effort, sign_response, farg=farg) assertion = self.setup_assertion( authn, sp_entity_id, in_response_to, consumer_url, name_id, policy, _issuer, authn_statement, [], True, sign_response, farg=farg, session_not_on_or_after=session_not_on_or_after) assertion.advice = saml.Advice() # assertion.advice.assertion_id_ref.append(saml.AssertionIDRef()) # assertion.advice.assertion_uri_ref.append(saml.AssertionURIRef()) assertion.advice.assertion.append(assertion_attributes) else: assertion = self.setup_assertion( authn, sp_entity_id, in_response_to, consumer_url, name_id, policy, _issuer, authn_statement, identity, True, sign_response, farg=farg, session_not_on_or_after=session_not_on_or_after) to_sign = [] if not encrypt_assertion: if sign_assertion: # XXX self.signing_algorithm self.digest_algorithm defined by entity # XXX this should be handled through entity.py # XXX sig/digest-allowed should be configurable sign_alg = sign_alg or self.signing_algorithm digest_alg = digest_alg or self.digest_algorithm assertion.signature = pre_signature_part( assertion.id, self.sec.my_cert, 2, sign_alg=sign_alg, digest_alg=digest_alg, ) to_sign.append((class_name(assertion), assertion.id)) if (self.support_AssertionIDRequest() or self.support_AuthnQuery()): self.session_db.store_assertion(assertion, to_sign) return self._response( in_response_to, consumer_url, status, issuer, sign_response, to_sign, sp_entity_id=sp_entity_id, encrypt_assertion=encrypt_assertion, encrypt_cert_advice=encrypt_cert_advice, encrypt_cert_assertion=encrypt_cert_assertion, encrypt_assertion_self_contained=encrypt_assertion_self_contained, encrypted_advice_attributes=encrypted_advice_attributes, sign_assertion=sign_assertion, pefim=pefim, sign_alg=sign_alg, digest_alg=digest_alg, assertion=assertion, ) # ------------------------------------------------------------------------ # XXX DONE idp create > _response def create_attribute_response( self, identity, in_response_to, destination, sp_entity_id, userid="", name_id=None, status=None, issuer=None, sign_assertion=None, sign_response=None, attributes=None, sign_alg=None, digest_alg=None, farg=None, **kwargs, ): """ Create an attribute assertion response. :param identity: A dictionary with attributes and values that are expected to be the bases for the assertion in the response. :param in_response_to: The session identifier of the request :param destination: The URL which should receive the response :param sp_entity_id: The entity identifier of the SP :param userid: A identifier of the user :param name_id: The identifier of the subject :param status: The status of the response :param issuer: The issuer of the response :param sign_assertion: Whether the assertion should be signed or not :param sign_response: Whether the whole response should be signed :param attributes: :param kwargs: To catch extra keyword arguments :return: A response instance """ policy = self.config.getattr("policy", "aa") if not name_id and userid: try: name_id = self.ident.construct_nameid(userid, policy, sp_entity_id) logger.warning("Unspecified NameID format") except Exception: pass to_sign = [] if identity: farg = self.update_farg(in_response_to, sp_entity_id, farg=farg) _issuer = self._issuer(issuer) ast = Assertion(identity) if policy: ast.apply_policy(sp_entity_id, policy) else: policy = Policy(mds=self.metadata) if attributes: restr = restriction_from_attribute_spec(attributes) ast = filter_attribute_value_assertions(ast) assertion = ast.construct( sp_entity_id, self.config.attribute_converters, policy, issuer=_issuer, name_id=name_id, farg=farg['assertion']) return self._response( in_response_to, destination, status, issuer, sign_response, to_sign, sign_assertion=sign_assertion, sign_alg=sign_alg, digest_alg=digest_alg, assertion=assertion, sp_entity_id=sp_entity_id, **kwargs, ) def gather_authn_response_args( self, sp_entity_id, name_id_policy, userid, **kwargs ): kwargs["policy"] = kwargs.get("release_policy") # collect args and return them args = {} # XXX will be passed to _authn_response param_defaults = { 'policy': None, 'best_effort': False, 'sign_assertion': False, 'sign_response': False, 'encrypt_assertion': False, 'encrypt_assertion_self_contained': True, 'encrypted_advice_attributes': False, 'encrypt_cert_advice': None, 'encrypt_cert_assertion': None, # need to be named sign_alg and digest_alg } for param, val_default in param_defaults.items(): val_kw = kwargs.get(param) val_config = self.config.getattr(param, "idp") args[param] = ( val_kw if val_kw is not None else val_config if val_config is not None else val_default ) for arg, attr, eca, pefim in [ ('encrypted_advice_attributes', 'verify_encrypt_cert_advice', 'encrypt_cert_advice', kwargs["pefim"]), ('encrypt_assertion', 'verify_encrypt_cert_assertion', 'encrypt_cert_assertion', False)]: if args[arg] or pefim: _enc_cert = self.config.getattr(attr, "idp") if _enc_cert is not None: if kwargs[eca] is None: raise CertificateError( "No SPCertEncType certificate for encryption " "contained in authentication " "request.") if not _enc_cert(kwargs[eca]): raise CertificateError( "Invalid certificate for encryption!") if 'name_id' not in kwargs or not kwargs['name_id']: nid_formats = [] for _sp in self.metadata[sp_entity_id]["spsso_descriptor"]: if "name_id_format" in _sp: nid_formats.extend([n["text"] for n in _sp["name_id_format"]]) try: snq = name_id_policy.sp_name_qualifier except AttributeError: snq = sp_entity_id if not snq: snq = sp_entity_id kwa = {"sp_name_qualifier": snq} try: kwa["format"] = name_id_policy.format except AttributeError: pass _nids = self.ident.find_nameid(userid, **kwa) # either none or one if _nids: args['name_id'] = _nids[0] else: args['name_id'] = self.ident.construct_nameid( userid, args['policy'], sp_entity_id, name_id_policy) logger.debug("construct_nameid: %s => %s", userid, args['name_id']) else: args['name_id'] = kwargs['name_id'] for param in ['status', 'farg']: try: args[param] = kwargs[param] except KeyError: pass return args # XXX DONE idp create > _authn_response > _response def create_authn_response( self, identity, in_response_to, destination, sp_entity_id, name_id_policy=None, userid=None, name_id=None, authn=None, issuer=None, sign_response=None, sign_assertion=None, encrypt_cert_advice=None, encrypt_cert_assertion=None, encrypt_assertion=None, encrypt_assertion_self_contained=True, encrypted_advice_attributes=False, pefim=False, sign_alg=None, digest_alg=None, session_not_on_or_after=None, **kwargs, ): """ Constructs an AuthenticationResponse :param identity: Information about an user :param in_response_to: The identifier of the authentication request this response is an answer to. :param destination: Where the response should be sent :param sp_entity_id: The entity identifier of the Service Provider :param name_id_policy: How the NameID should be constructed :param userid: The subject identifier :param name_id: The identifier of the subject. A saml.NameID instance. :param authn: Dictionary with information about the authentication context :param issuer: Issuer of the response :param sign_assertion: Whether the assertion should be signed or not. :param sign_response: Whether the response should be signed or not. :param encrypt_assertion: True if assertions should be encrypted. :param encrypt_assertion_self_contained: True if all encrypted assertions should have alla namespaces selfcontained. :param encrypted_advice_attributes: True if assertions in the advice element should be encrypted. :param encrypt_cert_advice: Certificate to be used for encryption of assertions in the advice element. :param encrypt_cert_assertion: Certificate to be used for encryption of assertions. :param pefim: True if a response according to the PEFIM profile should be created. :return: A response instance """ try: args = self.gather_authn_response_args( sp_entity_id, name_id_policy=name_id_policy, userid=userid, name_id=name_id, sign_response=sign_response, sign_assertion=sign_assertion, encrypt_cert_advice=encrypt_cert_advice, encrypt_cert_assertion=encrypt_cert_assertion, encrypt_assertion=encrypt_assertion, encrypt_assertion_self_contained=encrypt_assertion_self_contained, encrypted_advice_attributes=encrypted_advice_attributes, pefim=pefim, **kwargs, ) except IOError as exc: response = self.create_error_response( in_response_to, destination=destination, info=exc, sign=sign_response, sign_alg=sign_alg, digest_alg=digest_alg, ) return str(response).split("\n") try: _authn = authn return self._authn_response( in_response_to, destination, sp_entity_id, identity, authn=_authn, issuer=issuer, pefim=pefim, sign_alg=sign_alg, digest_alg=digest_alg, session_not_on_or_after=session_not_on_or_after, **args, ) except MissingValue as exc: return self.create_error_response( in_response_to, destination=destination, info=exc, sign=sign_response, sign_alg=sign_alg, digest_alg=digest_alg, ) # XXX DONE idp create > create_authn_response > _authn_response > _response def create_authn_request_response( self, identity, in_response_to, destination, sp_entity_id, name_id_policy=None, userid=None, name_id=None, authn=None, authn_decl=None, issuer=None, sign_response=None, sign_assertion=None, session_not_on_or_after=None, sign_alg=None, digest_alg=None, **kwargs, ): return self.create_authn_response( identity, in_response_to, destination, sp_entity_id, name_id_policy, userid, name_id, authn, issuer, sign_response, sign_assertion, authn_decl=authn_decl, session_not_on_or_after=session_not_on_or_after, sign_alg=sign_alg, digest_alg=digest_alg, ) # XXX DONE calls pre_signature_part # XXX DONE idp create > [...] def create_assertion_id_request_response( self, assertion_id, sign=None, sign_alg=None, digest_alg=None, **kwargs ): try: (assertion, to_sign) = self.session_db.get_assertion(assertion_id) except KeyError: raise Unknown if to_sign: if assertion.signature is None: # XXX self.signing_algorithm self.digest_algorithm defined by entity # XXX this should be handled through entity.py # XXX sig/digest-allowed should be configurable sign_alg = sign_alg or self.signing_algorithm digest_alg = digest_alg or self.digest_algorithm assertion.signature = pre_signature_part( assertion.id, self.sec.my_cert, 1, sign_alg=sign_alg, digest_alg=digest_alg, ) return signed_instance_factory(assertion, self.sec, to_sign) else: return assertion # XXX calls self.sign without ensuring sign # XXX calls self.sign => should it call _message (which calls self.sign)? # XXX idp create > NameIDMappingResponse & sign? def create_name_id_mapping_response( self, name_id=None, encrypted_id=None, in_response_to=None, issuer=None, sign_response=None, status=None, sign_alg=None, digest_alg=None, **kwargs, ): """ protocol for mapping a principal's name identifier into a different name identifier for the same principal. Done over soap. :param name_id: :param encrypted_id: :param in_response_to: :param issuer: :param sign_response: :param status: :return: """ # Done over SOAP ms_args = self.message_args() _resp = NameIDMappingResponse( name_id, encrypted_id, in_response_to=in_response_to, **ms_args ) if sign_response: return self.sign(_resp, sign_alg=sign_alg, digest_alg=digest_alg) else: logger.info("Message: %s", _resp) return _resp # XXX DONE idp create > _response def create_authn_query_response( self, subject, session_index=None, requested_context=None, in_response_to=None, issuer=None, sign_response=None, status=None, sign_alg=None, digest_alg=None, **kwargs, ): """ A successful will contain one or more assertions containing authentication statements. :return: """ margs = self.message_args() asserts = [ saml.Assertion(authn_statement=statement, subject=subject, **margs) for statement in self.session_db.get_authn_statements( subject.name_id, session_index, requested_context ) ] if asserts: args = {"assertion": asserts} else: args = {} return self._response( in_response_to, "", status, issuer, sign_response, to_sign=[], sign_alg=sign_alg, digest_alg=digest_alg, **args, ) # --------- def parse_ecp_authn_request(self): pass # XXX DONE idp create > create_authn_response > _authn_response > _response def create_ecp_authn_request_response( self, acs_url, identity, in_response_to, destination, sp_entity_id, name_id_policy=None, userid=None, name_id=None, authn=None, issuer=None, sign_response=None, sign_assertion=None, sign_alg=None, digest_alg=None, **kwargs, ): # ---------------------------------------- #