#!/usr/bin/env python # -*- coding: utf-8 -*- # # Copyright (C) 2009-2011 Umeå University # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """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 shelve import threading from saml2.eptid import EptidShelve, Eptid from saml2.saml import EncryptedAssertion from saml2.sdb import SessionStorage from saml2.schema import soapenv from saml2.samlp import NameIDMappingResponse from saml2.entity import Entity from saml2 import saml, element_to_extension_element from saml2 import class_name from saml2 import BINDING_HTTP_REDIRECT 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, Unknown, rndstr from saml2.sigver import pre_signature_part, signed_instance_factory, CertificateError, CryptoBackendXmlSec1 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 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" } 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=""): Entity.__init__(self, stype, config, config_file) self.eptid = None self.init_config(stype) self.cache = cache self.ticket = {} # self.session_db = self.choose_session_storage() # Needed for self.symkey = symkey self.seed = rndstr() self.iv = os.urandom(16) 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, basestring): 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, basestring): idb = shelve.open(dbspec, writeback=True) else: # database spec is a a 2-tuple (type, address) #print >> sys.stderr, "DBSPEC: %s" % (dbspec,) (typ, addr) = dbspec if typ == "shelve": idb = shelve.open(addr, writeback=True) 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") if typ == "mongodb": pass elif idb is not None: self.ident = IdentDB(idb) elif dbspec: raise Exception("Couldn't open identity database: %s" % (dbspec,)) _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) 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 :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 dictionary with keys: consumer_url - as gotten from the SPs entity_id and the metadata id - the id of the request sp_entity_id - the entity id of the SP request - The verified request """ 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) # ------------------------------------------------------------------------ # ------------------------------------------------------------------------ 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=False, sign_response=False, best_effort=False, encrypt_assertion=False, encrypt_cert=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 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. :return: A response instance """ to_sign = [] args = {} #if identity: _issuer = self._issuer(issuer) ast = Assertion(identity) if policy is None: policy = Policy() try: ast.apply_policy(sp_entity_id, policy, self.metadata) except MissingValue, exc: if not best_effort: return self.create_error_response(in_response_to, consumer_url, exc, sign_response) 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]) assertion = ast.construct(sp_entity_id, in_response_to, consumer_url, name_id, self.config.attribute_converters, policy, issuer=_issuer, **authn_args) else: assertion = ast.construct(sp_entity_id, in_response_to, consumer_url, name_id, self.config.attribute_converters, policy, issuer=_issuer) if sign_assertion is not None and sign_assertion: assertion.signature = pre_signature_part(assertion.id, self.sec.my_cert, 1) # Just the assertion or the response and the assertion ? to_sign = [(class_name(assertion), assertion.id)] # Store which assertion that has been sent to which SP about which # subject. # self.cache.set(assertion.subject.name_id.text, # sp_entity_id, {"ava": identity, "authn": authn}, # assertion.conditions.not_on_or_after) args["assertion"] = assertion 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, encrypt_assertion=encrypt_assertion, encrypt_cert=encrypt_cert, **args) # ------------------------------------------------------------------------ #noinspection PyUnusedLocal def create_attribute_response(self, identity, in_response_to, destination, sp_entity_id, userid="", name_id=None, status=None, issuer=None, sign_assertion=False, sign_response=False, attributes=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 = [] args = {} if identity: _issuer = self._issuer(issuer) ast = Assertion(identity) if policy: ast.apply_policy(sp_entity_id, policy, self.metadata) else: policy = Policy() if attributes: restr = restriction_from_attribute_spec(attributes) ast = filter_attribute_value_assertions(ast) assertion = ast.construct(sp_entity_id, in_response_to, destination, name_id, self.config.attribute_converters, policy, issuer=_issuer) if sign_assertion: assertion.signature = pre_signature_part(assertion.id, self.sec.my_cert, 1) # Just the assertion or the response and the assertion ? to_sign = [(class_name(assertion), assertion.id)] args["assertion"] = assertion return self._response(in_response_to, destination, status, issuer, sign_response, to_sign, **args) # ------------------------------------------------------------------------ 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=None, encrypt_assertion=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 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. :return: A response instance """ try: policy = kwargs["release_policy"] except KeyError: policy = self.config.getattr("policy", "idp") try: best_effort = kwargs["best_effort"] except KeyError: best_effort = False if sign_assertion is None: sign_assertion = self.config.getattr("sign_assertion", "idp") if sign_assertion is None: sign_assertion = False if sign_response is None: sign_response = self.config.getattr("sign_response", "idp") if sign_response is None: sign_response = False if encrypt_assertion is None: encrypt_assertion = self.config.getattr("encrypt_assertion", "idp") if encrypt_assertion is None: encrypt_assertion = False if encrypt_assertion: if encrypt_cert is not None: verify_encrypt_cert = self.config.getattr("verify_encrypt_cert", "idp") if verify_encrypt_cert is not None: if not verify_encrypt_cert(encrypt_cert): raise CertificateError("Invalid certificate for encryption!") else: raise CertificateError("No certificate for encryption!") else: encrypt_assertion = False if not name_id: try: 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: name_id = _nids[0] else: name_id = self.ident.construct_nameid(userid, policy, sp_entity_id, name_id_policy) except IOError, exc: response = self.create_error_response(in_response_to, destination, sp_entity_id, exc, name_id) return ("%s" % response).split("\n") try: _authn = authn response = None if (sign_assertion or sign_response) and self.sec.cert_handler.generate_cert(): with self.lock: self.sec.cert_handler.update_cert(True) return self._authn_response(in_response_to, # in_response_to destination, # consumer_url sp_entity_id, # sp_entity_id identity, # identity as dictionary name_id, authn=_authn, issuer=issuer, policy=policy, sign_assertion=sign_assertion, sign_response=sign_response, best_effort=best_effort, encrypt_assertion=encrypt_assertion, encrypt_cert=encrypt_cert) return self._authn_response(in_response_to, # in_response_to destination, # consumer_url sp_entity_id, # sp_entity_id identity, # identity as dictionary name_id, authn=_authn, issuer=issuer, policy=policy, sign_assertion=sign_assertion, sign_response=sign_response, best_effort=best_effort, encrypt_assertion=encrypt_assertion, encrypt_cert=encrypt_cert) except MissingValue, exc: return self.create_error_response(in_response_to, destination, sp_entity_id, exc, name_id) 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=False, sign_assertion=False, **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) #noinspection PyUnusedLocal def create_assertion_id_request_response(self, assertion_id, sign=False, **kwargs): """ :param assertion_id: :param sign: :return: """ try: (assertion, to_sign) = self.session_db.get_assertion(assertion_id) except KeyError: raise Unknown if to_sign: if assertion.signature is None: assertion.signature = pre_signature_part(assertion.id, self.sec.my_cert, 1) return signed_instance_factory(assertion, self.sec, to_sign) else: return assertion #noinspection PyUnusedLocal def create_name_id_mapping_response(self, name_id=None, encrypted_id=None, in_response_to=None, issuer=None, sign_response=False, status=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) else: logger.info("Message: %s" % _resp) return _resp def create_authn_query_response(self, subject, session_index=None, requested_context=None, in_response_to=None, issuer=None, sign_response=False, status=None, **kwargs): """ A successful will contain one or more assertions containing authentication statements. :return: """ margs = self.message_args() asserts = [] for statement in self.session_db.get_authn_statements( subject.name_id, session_index, requested_context): asserts.append(saml.Assertion(authn_statement=statement, subject=subject, **margs)) if asserts: args = {"assertion": asserts} else: args = {} return self._response(in_response_to, "", status, issuer, sign_response, to_sign=[], **args) # --------- def parse_ecp_authn_request(self): pass 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=False, sign_assertion=False, **kwargs): # ---------------------------------------- #