text: import base64
  import copy
  import logging
  import requests
  import six
  
  from binascii import hexlify
  from hashlib import sha1
  
  from saml2.metadata import ENDPOINTS
  from saml2.profile import paos, ecp, samlec
  from saml2.soap import parse_soap_enveloped_saml_artifact_resolve
  from saml2.soap import class_instances_from_soap_enveloped_saml_thingies
  from saml2.soap import open_soap_envelope
  
  from saml2 import samlp
  from saml2 import SamlBase
  from saml2 import SAMLError
  from saml2 import saml
  from saml2 import response as saml_response
  from saml2 import BINDING_URI
  from saml2 import BINDING_HTTP_ARTIFACT
  from saml2 import BINDING_PAOS
  from saml2 import request as saml_request
  from saml2 import soap
  from saml2 import element_to_extension_element
  from saml2 import extension_elements_to_elements
  
  from saml2.saml import NameID
  from saml2.saml import EncryptedAssertion
  from saml2.saml import Issuer
  from saml2.saml import NAMEID_FORMAT_ENTITY
  from saml2.response import AuthnResponse
  from saml2.response import LogoutResponse
  from saml2.response import UnsolicitedResponse
  from saml2.time_util import instant
  from saml2.s_utils import sid
  from saml2.s_utils import UnravelError
  from saml2.s_utils import error_status_factory
  from saml2.s_utils import rndbytes
  from saml2.s_utils import success_status_factory
  from saml2.s_utils import decode_base64_and_inflate
  from saml2.s_utils import UnsupportedBinding
  from saml2.samlp import AuthnRequest, SessionIndex, response_from_string
  from saml2.samlp import AuthzDecisionQuery
  from saml2.samlp import AuthnQuery
  from saml2.samlp import AssertionIDRequest
  from saml2.samlp import ManageNameIDRequest
  from saml2.samlp import NameIDMappingRequest
  from saml2.samlp import artifact_resolve_from_string
  from saml2.samlp import ArtifactResolve
  from saml2.samlp import ArtifactResponse
  from saml2.samlp import Artifact
  from saml2.samlp import LogoutRequest
  from saml2.samlp import AttributeQuery
  from saml2.mdstore import all_locations
  from saml2 import BINDING_HTTP_POST
  from saml2 import BINDING_HTTP_REDIRECT
  from saml2 import BINDING_SOAP
  from saml2 import VERSION
  from saml2 import class_name
  from saml2.config import config_factory
  from saml2.httpbase import HTTPBase
  from saml2.sigver import security_context
  from saml2.sigver import SigverError
  from saml2.sigver import SignatureError
  from saml2.sigver import make_temp
  from saml2.sigver import pre_encryption_part
  from saml2.sigver import pre_signature_part
  from saml2.sigver import pre_encrypt_assertion
  from saml2.sigver import signed_instance_factory
  from saml2.virtual_org import VirtualOrg
  from saml2.pack import http_redirect_message
  from saml2.pack import http_form_post_message
  
  from saml2.xmldsig import DefaultSignature
  from saml2.xmldsig import SIG_ALLOWED_ALG
  from saml2.xmldsig import DIGEST_ALLOWED_ALG
  
  
  logger = logging.getLogger(__name__)
  
  __author__ = 'rolandh'
  
  ARTIFACT_TYPECODE = b'\x00\x04'
  
  SERVICE2MESSAGE = {
      "single_sign_on_service": AuthnRequest,
      "attribute_service": AttributeQuery,
      "authz_service": AuthzDecisionQuery,
      "assertion_id_request_service": AssertionIDRequest,
      "authn_query_service": AuthnQuery,
      "manage_name_id_service": ManageNameIDRequest,
      "name_id_mapping_service": NameIDMappingRequest,
      "artifact_resolve_service": ArtifactResolve,
      "single_logout_service": LogoutRequest
  }
  
  
  class UnknownBinding(SAMLError):
      pass
  
  
  def create_artifact(entity_id, message_handle, endpoint_index=0):
      """
      SAML_artifact   := B64(TypeCode EndpointIndex RemainingArtifact)
      TypeCode        := Byte1Byte2
      EndpointIndex   := Byte1Byte2
  
      RemainingArtifact := SourceID MessageHandle
      SourceID          := 20-byte_sequence
      MessageHandle     := 20-byte_sequence
  
      :param entity_id:
      :param message_handle:
      :param endpoint_index:
      :return:
      """
      if not isinstance(entity_id, six.binary_type):
          entity_id = entity_id.encode('utf-8')
      sourceid = sha1(entity_id)
  
      if not isinstance(message_handle, six.binary_type):
          message_handle = message_handle.encode('utf-8')
      ter = b"".join((ARTIFACT_TYPECODE,
                      ("%.2x" % endpoint_index).encode('ascii'),
                      sourceid.digest(),
                      message_handle))
      return base64.b64encode(ter).decode('ascii')
  
  
  class Entity(HTTPBase):
      def __init__(self, entity_type, config=None, config_file="",
                   virtual_organization="", msg_cb=None):
          self.entity_type = entity_type
          self.users = None
  
          if config:
              self.config = config
          elif config_file:
              self.config = config_factory(entity_type, config_file)
          else:
              raise SAMLError("Missing configuration")
  
          def_sig = DefaultSignature()
          self.signing_algorithm = (
              self.config.getattr('signing_algorithm')
              or def_sig.get_sign_alg()
          )
          self.digest_algorithm = (
              self.config.getattr('digest_algorithm')
              or def_sig.get_digest_alg()
          )
  
          sign_config_per_entity_type = {
              'sp': self.config.getattr("authn_requests_signed", "sp"),
              'idp': self.config.getattr("sign_response", "idp"),
          }
          sign_config = sign_config_per_entity_type.get(self.entity_type, False)
          self.should_sign = sign_config
  
          for item in ["cert_file", "key_file", "ca_certs"]:
              _val = getattr(self.config, item, None)
              if not _val:
                  continue
  
              if _val.startswith("http"):
                  r = requests.request("GET", _val)
                  if r.status_code == 200:
                      tmp = make_temp(r.text, ".pem", False, self.config.delete_tmpfiles)
                      setattr(self.config, item, tmp.name)
                  else:
                      raise Exception(
                          "Could not fetch certificate from %s" % _val)
  
          HTTPBase.__init__(self, self.config.verify_ssl_cert,
                            self.config.ca_certs, self.config.key_file,
                            self.config.cert_file)
  
          if self.config.vorg:
              for vo in self.config.vorg.values():
                  vo.sp = self
  
          self.metadata = self.config.metadata
          self.debug = self.config.debug
  
          self.sec = security_context(self.config)
  
          if virtual_organization:
              if isinstance(virtual_organization, six.string_types):
                  self.vorg = self.config.vorg[virtual_organization]
              elif isinstance(virtual_organization, VirtualOrg):
                  self.vorg = virtual_organization
          else:
              self.vorg = None
  
          self.artifact = {}
          if self.metadata:
              self.sourceid = self.metadata.construct_source_id()
          else:
              self.sourceid = {}
  
          self.msg_cb = msg_cb
  
      def _issuer(self, entityid=None):
          """ Return an Issuer instance """
          if entityid:
              if isinstance(entityid, Issuer):
                  return entityid
              else:
                  return Issuer(text=entityid, format=NAMEID_FORMAT_ENTITY)
          else:
              return Issuer(text=self.config.entityid,
                            format=NAMEID_FORMAT_ENTITY)
  
      # XXX DONE will actually use sign_alg and digest_alg for the Redirect-Binding
      # XXX DONE deepest level - needs to decide the sign_alg (no digest_alg here)
      # XXX verify digest_alg is not needed
      # XXX deprecate sigalg for sign_alg
      def apply_binding(
          self,
          binding,
          msg_str,
          destination="",
          relay_state="",
          response=False,
          sign=None,
          sigalg=None,
          **kwargs,
      ):
          """
          Construct the necessary HTTP arguments dependent on Binding
  
          :param binding: Which binding to use
          :param msg_str: The return message as a string (XML) if the message is
              to be signed it MUST contain the signature element.
          :param destination: Where to send the message
          :param relay_state: Relay_state if provided
          :param response: Which type of message this is
          :param kwargs: response type specific arguments
          :return: A dictionary
          """
  
          # XXX SIG_ALLOWED_ALG should be configurable
          # XXX should_sign stems from authn_requests_signed and sign_response
          # XXX based on the type of the entity
          # XXX but should also take into account the type of message (Authn/Logout/etc)
          # XXX should_sign should be split and the exact config options should be checked
          sign = sign if sign is not None else self.should_sign
          sign_alg = sigalg or self.signing_algorithm
          if sign_alg not in [long_name for short_name, long_name in SIG_ALLOWED_ALG]:
              raise Exception(
                  "Signature algo not in allowed list: {algo}".format(algo=sign_alg)
              )
  
          # unless if BINDING_HTTP_ARTIFACT
          if response:
              typ = "SAMLResponse"
          else:
              typ = "SAMLRequest"
  
          if binding == BINDING_HTTP_POST:
              logger.info("HTTP POST")
              info = http_form_post_message(msg_str, destination, relay_state, typ)
              (msg_str, destination, relay_state, typ)
              info["url"] = destination
              info["method"] = "POST"
          elif binding == BINDING_HTTP_REDIRECT:
              logger.info("HTTP REDIRECT")
              info = http_redirect_message(
                  message=msg_str,
                  location=destination,
                  relay_state=relay_state,
                  typ=typ,
                  sign=sign,
                  sigalg=sign_alg,
                  backend=self.sec.sec_backend,
              )
              info["url"] = str(destination)
              info["method"] = "GET"
          elif binding == BINDING_SOAP or binding == BINDING_PAOS:
              info = self.use_soap(
                  msg_str, destination, sign=sign, sigalg=sign_alg, **kwargs
              )
          elif binding == BINDING_URI:
              info = self.use_http_uri(msg_str, typ, destination)
          elif binding == BINDING_HTTP_ARTIFACT:
              if response:
                  info = self.use_http_artifact(msg_str, destination, relay_state)
                  info["method"] = "GET"
                  info["status"] = 302  # TODO: should be 303 on >= HTTP/1.1
              else:
                  info = self.use_http_artifact(msg_str, destination, relay_state)
          else:
              raise SAMLError("Unknown binding type: %s" % binding)
  
          return info
  
      def pick_binding(
          self, service, bindings=None, descr_type="", request=None, entity_id=""
      ):
          if request and not entity_id:
              entity_id = request.issuer.text.strip()
  
          sfunc = getattr(self.metadata, service)
  
          if bindings is None:
              if request and request.protocol_binding:
                  bindings = [request.protocol_binding]
              else:
                  bindings = self.config.preferred_binding[service]
  
          if not descr_type:
              if self.entity_type == "sp":
                  descr_type = "idpsso"
              else:
                  descr_type = "spsso"
  
          _url = getattr(request, "%s_url" % service, None)
          _index = getattr(request, "%s_index" % service, None)
  
          for binding in bindings:
              try:
                  srvs = sfunc(entity_id, binding, descr_type)
                  if srvs:
                      if _url:
                          for srv in srvs:
                              if srv["location"] == _url:
                                  return binding, _url
                      elif _index:
                          for srv in srvs:
                              if srv["index"] == _index:
                                  return binding, srv["location"]
                      else:
                          destination = next(all_locations(srvs), None)
                          return binding, destination
              except UnsupportedBinding:
                  pass
  
          logger.error("Failed to find consumer URL: %s, %s, %s",
                       entity_id, bindings, descr_type)
          # logger.error("Bindings: %s", bindings)
          # logger.error("Entities: %s", self.metadata)
  
          raise SAMLError("Unknown entity or unsupported bindings")
  
      def message_args(self, message_id=0):
          if not message_id:
              message_id = sid()
  
          margs = {
              "id": message_id,
              "version": VERSION,
              "issue_instant": instant(),
              "issuer": self._issuer(),
          }
          return margs
  
      def response_args(self, message, bindings=None, descr_type=""):
          """
  
          :param message: The message to which a reply is constructed
          :param bindings: Which bindings can be used.
          :param descr_type: Type of descriptor (spssp, idpsso, )
          :return: Dictionary
          """
          info = {"in_response_to": message.id}
  
          if isinstance(message, AuthnRequest):
              rsrv = "assertion_consumer_service"
              descr_type = "spsso"
              info["sp_entity_id"] = message.issuer.text
              info["name_id_policy"] = message.name_id_policy
          elif isinstance(message, LogoutRequest):
              rsrv = "single_logout_service"
          elif isinstance(message, AttributeQuery):
              info["sp_entity_id"] = message.issuer.text
              rsrv = "attribute_consuming_service"
              descr_type = "spsso"
          elif isinstance(message, ManageNameIDRequest):
              rsrv = "manage_name_id_service"
          # The once below are solely SOAP so no return destination needed
          elif isinstance(message, AssertionIDRequest):
              rsrv = ""
          elif isinstance(message, ArtifactResolve):
              rsrv = ""
          elif isinstance(message, AssertionIDRequest):
              rsrv = ""
          elif isinstance(message, NameIDMappingRequest):
              rsrv = ""
          else:
              raise SAMLError("No support for this type of query")
  
          if bindings == [BINDING_SOAP]:
              info["binding"] = BINDING_SOAP
              info["destination"] = ""
              return info
  
          if rsrv:
              if not descr_type:
                  if self.entity_type == "sp":
                      descr_type = "idpsso"
                  else:
                      descr_type = "spsso"
  
              binding, destination = self.pick_binding(
                  rsrv, bindings, descr_type=descr_type, request=message
              )
              info["binding"] = binding
              info["destination"] = destination
  
          return info
  
      @staticmethod
      def unravel(txt, binding, msgtype="response"):
          """
          Will unpack the received text. Depending on the context the original
           response may have been transformed before transmission.
          :param txt:
          :param binding:
          :param msgtype:
          :return:
          """
          # logger.debug("unravel '%s'", txt)
          if binding not in [BINDING_HTTP_REDIRECT, BINDING_HTTP_POST,
                             BINDING_SOAP, BINDING_URI, BINDING_HTTP_ARTIFACT,
                             None]:
              raise UnknownBinding("Don't know how to handle '%s'" % binding)
          else:
              try:
                  if binding == BINDING_HTTP_REDIRECT:
                      xmlstr = decode_base64_and_inflate(txt)
                  elif binding == BINDING_HTTP_POST:
                      xmlstr = base64.b64decode(txt)
                  elif binding == BINDING_SOAP:
                      func = getattr(soap,
                                     "parse_soap_enveloped_saml_%s" % msgtype)
                      xmlstr = func(txt)
                  elif binding == BINDING_HTTP_ARTIFACT:
                      xmlstr = base64.b64decode(txt)
                  else:
                      xmlstr = txt
              except Exception:
                  raise UnravelError("Unravelling binding '%s' failed" % binding)
  
          return xmlstr
  
      @staticmethod
      def parse_soap_message(text):
          """
  
          :param text: The SOAP message
          :return: A dictionary with two keys "body" and "header"
          """
          return class_instances_from_soap_enveloped_saml_thingies(text, [paos,
                                                                          ecp,
                                                                          samlp,
                                                                          samlec])
  
      @staticmethod
      def unpack_soap_message(text):
          """
          Picks out the parts of the SOAP message, body and headers apart
          :param text: The SOAP message
          :return: A dictionary with two keys "body"/"header"
          """
          return open_soap_envelope(text)
  
      # --------------------------------------------------------------------------
  
      # XXX DONE will actually use sign_alg and digest_alg for the POST-Binding
      # XXX DONE deepest level - needs to decide the sign_alg and digest_alg value
      # XXX a controler for signed_instance_factory
      # XXX syncs pre_signature_part and signed_instance_factory
      # XXX makes sure pre_signature_part is called before signed_instance_factory
      # XXX calls pre_signature_part - must have sign_alg & digest_alg
      # XXX calls signed_instance_factory - after pre_signature_part
      # XXX !!expects a msg object!!
      def sign(
          self,
          msg,
          mid=None,
          to_sign=None,
          sign_prepare=None,
          sign_alg=None,
          digest_alg=None,
      ):
          # XXX sig/digest-allowed should be configurable
          sign_alg = sign_alg or self.signing_algorithm
          digest_alg = digest_alg or self.digest_algorithm
          if sign_alg not in [long_name for short_name, long_name in SIG_ALLOWED_ALG]:
              raise Exception(
                  "Signature algo not in allowed list: {algo}".format(algo=sign_alg)
              )
          if digest_alg not in [long_name for short_name, long_name in DIGEST_ALLOWED_ALG]:
              raise Exception(
                  "Digest algo not in allowed list: {algo}".format(algo=digest_alg)
              )
  
          if msg.signature is None:
              msg.signature = pre_signature_part(
                  msg.id, self.sec.my_cert, 1, sign_alg=sign_alg, digest_alg=digest_alg
              )
  
          if sign_prepare:
              return msg
  
          if mid is None:
              mid = msg.id
  
          try:
              to_sign += [(class_name(msg), mid)]
          except (AttributeError, TypeError):
              to_sign = [(class_name(msg), mid)]
  
          logger.info("REQUEST: %s", msg)
          return signed_instance_factory(msg, self.sec, to_sign)
  
      # XXX DONE will actually use sign the POST-Binding
      # XXX DONE deepest level - needs to decide the sign value
      # XXX DONE calls self.sign must figure out sign
      # XXX DONE ensure both SPs and IdPs go through this
      # XXX DONE ensure this works for the POST-Binding
      def _message(
          self,
          request_cls,
          destination=None,
          message_id=0,
          consent=None,
          extensions=None,
          sign=None,
          sign_prepare=None,
          nsprefix=None,
          sign_alg=None,
          digest_alg=None,
          **kwargs,
      ):
          """
          Some parameters appear in all requests so simplify by doing
          it in one place
  
          :param request_cls: The specific request type
          :param destination: The recipient
          :param message_id: A message identifier
          :param consent: Whether the principal have given her consent
          :param extensions: Possible extensions
          :param sign: Whether the request should be signed or not.
          :param sign_prepare: Whether the signature should be prepared or not.
          :param kwargs: Key word arguments specific to one request type
          :return: A tuple containing the request ID and an instance of the
              request_cls
          """
          if not message_id:
              message_id = sid()
  
          for key, val in self.message_args(message_id).items():
              if key not in kwargs:
                  kwargs[key] = val
  
          req = request_cls(**kwargs)
  
          if destination:
              req.destination = destination
  
          if consent:
              req.consent = "true"
  
          if extensions:
              req.extensions = extensions
  
          if nsprefix:
              req.register_prefix(nsprefix)
  
          if self.msg_cb:
              req = self.msg_cb(req)
  
          reqid = req.id
  
          sign = sign if sign is not None else self.should_sign
          if sign:
              signed_req = self.sign(
                  req,
                  sign_prepare=sign_prepare,
                  sign_alg=sign_alg,
                  digest_alg=digest_alg,
              )
              req = signed_req
  
          logger.info("REQUEST: %s", req)
          return reqid, req
  
      @staticmethod
      def _filter_args(instance, extensions=None, **kwargs):
          args = {}
          if extensions is None:
              extensions = []
  
          allowed_attributes = instance.keys()
          for key, val in kwargs.items():
              if key in allowed_attributes:
                  args[key] = val
              elif isinstance(val, SamlBase):
                  # extension elements allowed ?
                  extensions.append(element_to_extension_element(val))
  
          return args, extensions
  
      def _add_info(self, msg, **kwargs):
          """
          Add information to a SAML message. If the attribute is not part of
          what's defined in the SAML standard add it as an extension.
  
          :param msg:
          :param kwargs:
          :return:
          """
  
          args, extensions = self._filter_args(msg, **kwargs)
          for key, val in args.items():
              setattr(msg, key, val)
  
          if extensions:
              if msg.extension_elements:
                  msg.extension_elements.extend(extensions)
              else:
                  msg.extension_elements = extensions
  
      def has_encrypt_cert_in_metadata(self, sp_entity_id):
          """ Verifies if the metadata contains encryption certificates.
  
          :param sp_entity_id: Entity ID for the calling service provider.
          :return: True if encrypt cert exists in metadata, otherwise False.
          """
          if sp_entity_id is not None:
              _certs = self.metadata.certs(sp_entity_id, "any", "encryption")
              if len(_certs) > 0:
                  return True
          return False
  
      def _encrypt_assertion(self, encrypt_cert, sp_entity_id, response, node_xpath=None):
          """ Encryption of assertions.
  
          :param encrypt_cert: Certificate to be used for encryption.
          :param sp_entity_id: Entity ID for the calling service provider.
          :param response: A samlp.Response
          :param node_xpath: Unquie path to the element to be encrypted.
          :return: A new samlp.Resonse with the designated assertion encrypted.
          """
          _certs = []
  
          if encrypt_cert:
              _certs.append(encrypt_cert)
          elif sp_entity_id is not None:
              _certs = self.metadata.certs(sp_entity_id, "any", "encryption")
          exception = None
          for _cert in _certs:
              try:
                  begin_cert = "-----BEGIN CERTIFICATE-----\n"
                  end_cert = "\n-----END CERTIFICATE-----\n"
                  if begin_cert not in _cert:
                      _cert = "%s%s" % (begin_cert, _cert)
                  if end_cert not in _cert:
                      _cert = "%s%s" % (_cert, end_cert)
                  tmp = make_temp(_cert.encode('ascii'),
                                  decode=False,
                                  delete_tmpfiles=self.config.delete_tmpfiles)
                  response = self.sec.encrypt_assertion(response, tmp.name,
                                                        pre_encryption_part(),
                                                        node_xpath=node_xpath)
                  return response
              except Exception as ex:
                  exception = ex
                  pass
          if exception:
              raise exception
          return response
  
      # XXX DONE calls self.sign must figure out sign
      # XXX calls signed_instance_factory - must have called pre_signature_part
      # XXX calls pre_signature_part - must figure out sign_alg/digest_alg
      def _response(
          self,
          in_response_to,
          consumer_url=None,
          status=None,
          issuer=None,
          sign=None,
          to_sign=None,
          sp_entity_id=None,
          encrypt_assertion=False,
          encrypt_assertion_self_contained=False,
          encrypted_advice_attributes=False,
          encrypt_cert_advice=None,
          encrypt_cert_assertion=None,
          sign_assertion=None,
          pefim=False,
          sign_alg=None,
          digest_alg=None,
          **kwargs,
      ):
          """ Create a Response.
              Encryption:
                  encrypt_assertion must be true for encryption to be
                  performed. If encrypted_advice_attributes also is
                  true, then will the function try to encrypt the assertion in
                  the the advice element of the main
                  assertion. Only one assertion element is allowed in the
                  advice element, if multiple assertions exists
                  in the advice element the main assertion will be encrypted
                  instead, since it's no point to encrypt
                  If encrypted_advice_attributes is
                  false the main assertion will be encrypted. Since the same key
  
          :param in_response_to: The session identifier of the request
          :param consumer_url: The URL which should receive the response
          :param status: An instance of samlp.Status
          :param issuer: The issuer of the response
          :param sign: Whether the response should be signed or not
          :param to_sign: If there are other parts to sign
          :param sp_entity_id: Entity ID for the calling service provider.
          :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 sign_assertion: True if assertions should be signed.
          :param pefim: True if a response according to the PEFIM profile
          should be created.
          :param kwargs: Extra key word arguments
          :return: A Response instance
          """
  
          if not status:
              status = success_status_factory()
  
          _issuer = self._issuer(issuer)
  
          response = samlp.Response(id=sid(), version=VERSION, issue_instant=instant())
          response.issuer = _issuer
          response.in_response_to = in_response_to
          response.status = status
  
          if consumer_url:
              response.destination = consumer_url
  
          self._add_info(response, **kwargs)
  
          sign = sign if sign is not None else self.should_sign
          if (
              to_sign
              and not sign
              and not encrypt_assertion
          ):
              return signed_instance_factory(response, self.sec, to_sign)
  
          has_encrypt_cert = self.has_encrypt_cert_in_metadata(sp_entity_id)
          if not has_encrypt_cert and encrypt_cert_advice is None:
              encrypted_advice_attributes = False
          if not has_encrypt_cert and encrypt_cert_assertion is None:
              encrypt_assertion = False
  
          # XXX if encrypt_assertion or encrypted_advice_attributes
          # XXX once in, response becomes a str and uses signed_instance_factory
          if (
              # XXX goto part-C
              encrypt_assertion
              or (
                  # XXX goto part-B
                  encrypted_advice_attributes
                  and response.assertion.advice is not None
                  and len(response.assertion.advice.assertion) == 1
              )
          ):
              # XXX sig/digest-allowed should be configurable
              sign_alg = sign_alg or self.signing_algorithm
              digest_alg = digest_alg or self.digest_algorithm
  
              # XXX part-A (common) prepare sign response
              if sign:
                  response.signature = pre_signature_part(
                      response.id,
                      self.sec.my_cert,
                      1,
                      sign_alg=sign_alg,
                      digest_alg=digest_alg,
                  )
                  sign_class = [(class_name(response), response.id)]
              else:
                  sign_class = []
  
              # XXX part-B if encrypted_advice_attributes
              if (
                  encrypted_advice_attributes
                  and response.assertion.advice is not None
                  and len(response.assertion.advice.assertion) > 0
              ):
                  _assertions = response.assertion
                  if not isinstance(_assertions, list):
                      _assertions = [_assertions]
  
                  for _assertion in _assertions:
                      _assertion.advice.encrypted_assertion = []
                      _assertion.advice.encrypted_assertion.append(EncryptedAssertion())
                      _advice_assertions = copy.deepcopy(_assertion.advice.assertion)
                      _assertion.advice.assertion = []
  
                      if not isinstance(_advice_assertions, list):
                          _advice_assertions = [_advice_assertions]
  
                      for tmp_assertion in _advice_assertions:
                          to_sign_advice = []
                          # XXX prepare sign assertion
                          if sign_assertion and not pefim:
                              tmp_assertion.signature = pre_signature_part(
                                  tmp_assertion.id,
                                  self.sec.my_cert,
                                  1,
                                  sign_alg=sign_alg,
                                  digest_alg=digest_alg,
                              )
                              to_sign_advice.append(
                                  (class_name(tmp_assertion), tmp_assertion.id),
                              )
  
                          # XXX prepare encrypt assertion
                          # tmp_assertion = response.assertion.advice.assertion[0]
                          _assertion.advice.encrypted_assertion[0].add_extension_element(
                              tmp_assertion
                          )
                          if encrypt_assertion_self_contained:
                              advice_tag = response.assertion.advice._to_element_tree().tag
                              assertion_tag = tmp_assertion._to_element_tree().tag
                              response = response.get_xml_string_with_self_contained_assertion_within_advice_encrypted_assertion(
                                  assertion_tag, advice_tag
                              )
                          node_xpath = ''.join(
                              [
                                  "/*[local-name()=\"%s\"]" % v
                                  for v in [
                                      "Response",
                                      "Assertion",
                                      "Advice",
                                      "EncryptedAssertion",
                                      "Assertion"
                                  ]
                              ]
                          )
  
                          # XXX sign assertion
                          if to_sign_advice:
                              response = signed_instance_factory(
                                  response, self.sec, to_sign_advice
                              )
  
                          # XXX encrypt assertion
                          response = self._encrypt_assertion(
                              encrypt_cert_advice,
                              sp_entity_id,
                              response,
                              node_xpath=node_xpath,
                          )
                          response = response_from_string(response)
  
              # XXX part-C if encrypt_assertion
              if encrypt_assertion:
                  to_sign_assertion = []
  
                  # XXX prepare sign assertion
                  if sign_assertion:
                      _assertions = response.assertion
  
                      if not isinstance(_assertions, list):
                          _assertions = [_assertions]
  
                      for _assertion in _assertions:
                          _assertion.signature = pre_signature_part(
                              _assertion.id,
                              self.sec.my_cert,
                              1,
                              sign_alg=sign_alg,
                              digest_alg=digest_alg,
                          )
                          to_sign_assertion.append(
                              (class_name(_assertion), _assertion.id),
                          )
  
                  # XXX prepare encrypt assertion
                  if encrypt_assertion_self_contained:
                      try:
                          assertion_tag = response.assertion._to_element_tree().tag
                      except:
                          assertion_tag = response.assertion[0]._to_element_tree().tag
                      response = pre_encrypt_assertion(response)
                      response = response.get_xml_string_with_self_contained_assertion_within_encrypted_assertion(
                          assertion_tag
                      )
                  else:
                      response = pre_encrypt_assertion(response)
  
                  # XXX sign assertion
                  if to_sign_assertion:
                      response = signed_instance_factory(
                          response, self.sec, to_sign_assertion
                      )
  
                  # XXX encrypt assertion
                  response = self._encrypt_assertion(
                      encrypt_cert_assertion, sp_entity_id, response
                  )
              else:
                  # XXX sign other parts! (defiend by to_sign)
                  if to_sign:
                      response = signed_instance_factory(response, self.sec, to_sign)
  
              # XXX part-D (common) sign response
              # XXX handle response having been signed/encrypted => str
              if sign:
                  return signed_instance_factory(response, self.sec, sign_class)
              else:
                  return response
  
          # XXX sign response
          if sign:
              return self.sign(
                  response, to_sign=to_sign, sign_alg=sign_alg, digest_alg=digest_alg
              )
  
          return response
  
      # XXX DONE calls self.sign must figure out sign
      def _status_response(
          self,
          response_class,
          issuer,
          status,
          sign=None,
          sign_alg=None,
          digest_alg=None,
          **kwargs,
      ):
          """ Create a StatusResponse.
  
          :param response_class: Which subclass of StatusResponse that should be
              used
          :param issuer: The issuer of the response message
          :param status: The return status of the response operation
          :param sign: Whether the response should be signed or not
          :param kwargs: Extra arguments to the response class
          :return: Class instance or string representation of the instance
          """
  
          mid = sid()
  
          for key in ["binding"]:
              kwargs.pop(key, None)
  
          if not status:
              status = success_status_factory()
  
          response = response_class(
              issuer=issuer,
              id=mid,
              version=VERSION,
              issue_instant=instant(),
              status=status,
              **kwargs,
          )
  
          sign = sign if sign is not None else self.should_sign
          if sign:
              return self.sign(response, mid, sign_alg=sign_alg, digest_alg=digest_alg)
          else:
              return response
  
      # ------------------------------------------------------------------------
  
      @staticmethod
      def srv2typ(service):
          for typ in ["aa", "pdp", "aq"]:
              if service in ENDPOINTS[typ]:
                  if typ == "aa":
                      return "attribute_authority"
                  elif typ == "aq":
                      return "authn_authority"
                  else:
                      return typ
  
      def _parse_request(self, enc_request, request_cls, service, binding):
          """Parse a Request
  
          :param enc_request: The request in its transport format
          :param request_cls: The type of requests I expect
          :param service:
          :param binding: Which binding that was used to transport the message
              to this entity.
          :return: A request instance
          """
  
          _log_info = logger.info
          _log_debug = logger.debug
  
          # The addresses I should receive messages like this on
          receiver_addresses = self.config.endpoint(service, binding,
                                                    self.entity_type)
          if not receiver_addresses and self.entity_type == "idp":
              for typ in ["aa", "aq", "pdp"]:
                  receiver_addresses = self.config.endpoint(service, binding, typ)
                  if receiver_addresses:
                      break
  
          _log_debug("receiver addresses: %s", receiver_addresses)
          _log_debug("Binding: %s", binding)
  
          try:
              timeslack = self.config.accepted_time_diff
              if not timeslack:
                  timeslack = 0
          except AttributeError:
              timeslack = 0
  
          _request = request_cls(self.sec, receiver_addresses,
                                 self.config.attribute_converters,
                                 timeslack=timeslack)
  
          xmlstr = self.unravel(enc_request, binding, request_cls.msgtype)
          must = self.config.getattr("want_authn_requests_signed", "idp")
          only_valid_cert = self.config.getattr(
              "want_authn_requests_only_with_valid_cert", "idp")
          if only_valid_cert is None:
              only_valid_cert = False
          if only_valid_cert:
              must = True
          _request = _request.loads(xmlstr, binding, origdoc=enc_request,
                                    must=must, only_valid_cert=only_valid_cert)
  
          _log_debug("Loaded request")
  
          if _request:
              _request.verify()
              _log_debug("Verified request")
  
          if not _request:
              return None
          else:
              return _request
  
      # ------------------------------------------------------------------------
  
      # XXX DONE ent create > _response
      def create_error_response(
          self,
          in_response_to,
          destination,
          info,
          sign=None,
          issuer=None,
          sign_alg=None,
          digest_alg=None,
          **kwargs,
      ):
          """ Create a error response.
  
          :param in_response_to: The identifier of the message this is a response
              to.
          :param destination: The intended recipient of this message
          :param info: Either an Exception instance or a 2-tuple consisting of
              error code and descriptive text
          :param sign: Whether the response should be signed or not
          :param issuer: The issuer of the response
          :param kwargs: To capture key,value pairs I don't care about
          :return: A response instance
          """
          status = error_status_factory(info)
  
          return self._response(
              in_response_to,
              destination,
              status,
              issuer,
              sign,
              sign_alg=sign_alg,
              digest_alg=digest_alg,
          )
  
      # ------------------------------------------------------------------------
  
      # XXX DONE ent create > _message
      def create_logout_request(
          self,
          destination,
          issuer_entity_id,
          subject_id=None,
          name_id=None,
          reason=None,
          expire=None,
          message_id=0,
          consent=None,
          extensions=None,
          sign=None,
          session_indexes=None,
          sign_alg=None,
          digest_alg=None,
      ):
          """ Constructs a LogoutRequest
  
          :param destination: Destination of the request
          :param issuer_entity_id: The entity ID of the IdP the request is
              target at.
          :param subject_id: The identifier of the subject
          :param name_id: A NameID instance identifying the subject
          :param reason: An indication of the reason for the logout, in the
              form of a URI reference.
          :param expire: The time at which the request expires,
              after which the recipient may discard the message.
          :param message_id: Request identifier
          :param consent: Whether the principal have given her consent
          :param extensions: Possible extensions
          :param sign: Whether the query should be signed or not.
          :param session_indexes: SessionIndex instances or just values
          :return: A LogoutRequest instance
          """
  
          if subject_id:
              if self.entity_type == "idp":
                  name_id = NameID(
                      text=self.users.get_entityid(subject_id, issuer_entity_id, False)
                  )
              else:
                  name_id = NameID(text=subject_id)
  
          if not name_id:
              raise SAMLError("Missing subject identification")
  
          args = {}
          if session_indexes:
              sis = []
              for si in session_indexes:
                  if isinstance(si, SessionIndex):
                      sis.append(si)
                  else:
                      sis.append(SessionIndex(text=si))
              args["session_index"] = sis
  
          return self._message(
              LogoutRequest,
              destination,
              message_id,
              consent,
              extensions,
              sign,
              name_id=name_id,
              reason=reason,
              not_on_or_after=expire,
              issuer=self._issuer(),
              sign_alg=sign_alg,
              digest_alg=digest_alg,
              **args,
          )
  
      # XXX DONE ent create > _status_response
      def create_logout_response(
          self,
          request,
          bindings=None,
          status=None,
          sign=None,
          issuer=None,
          sign_alg=None,
          digest_alg=None,
      ):
          """ Create a LogoutResponse.
  
          :param request: The request this is a response to
          :param bindings: Which bindings that can be used for the response
              If None the preferred bindings are gathered from the configuration
          :param status: The return status of the response operation
              If None the operation is regarded as a Success.
          :param issuer: The issuer of the message
          :return: HTTP args
          """
  
          rinfo = self.response_args(request, bindings)
  
          if not issuer:
              issuer = self._issuer()
  
          response = self._status_response(
              samlp.LogoutResponse,
              issuer,
              status,
              sign,
              sign_alg=sign_alg,
              digest_alg=digest_alg,
              **rinfo,
          )
  
          logger.info("Response: %s", response)
  
          return response
  
      # XXX DONE ent create > _message
      def create_artifact_resolve(
          self,
          artifact,
          destination,
          sessid,
          consent=None,
          extensions=None,
          sign=None,
          sign_alg=None,
          digest_alg=None,
      ):
          """
          Create a ArtifactResolve request
  
          :param artifact:
          :param destination:
          :param sessid: session id
          :param consent:
          :param extensions:
          :param sign:
          :return: The request message
          """
  
          artifact = Artifact(text=artifact)
  
          return self._message(
              ArtifactResolve,
              destination,
              sessid,
              consent,
              extensions,
              sign,
              artifact=artifact,
              sign_alg=sign_alg,
              digest_alg=digest_alg,
          )
  
      # XXX DONE ent create > _status_response
      def create_artifact_response(
          self,
          request,
          artifact,
          bindings=None,
          status=None,
          sign=None,
          issuer=None,
          sign_alg=None,
          digest_alg=None,
      ):
          """
          Create an ArtifactResponse
          :return:
          """
  
          rinfo = self.response_args(request, bindings)
          response = self._status_response(
              ArtifactResponse,
              issuer,
              status,
              sign=sign,
              sign_alg=sign_alg,
              digest_alg=digest_alg,
              **rinfo,
          )
  
          msg = element_to_extension_element(self.artifact[artifact])
          response.extension_elements = [msg]
  
          logger.info("Response: %s", response)
  
          return response
  
      # XXX DONE ent create > _message
      def create_manage_name_id_request(
          self,
          destination,
          message_id=0,
          consent=None,
          extensions=None,
          sign=None,
          name_id=None,
          new_id=None,
          encrypted_id=None,
          new_encrypted_id=None,
          terminate=None,
          sign_alg=None,
          digest_alg=None,
      ):
          """
  
          :param destination:
          :param message_id:
          :param consent:
          :param extensions:
          :param sign:
          :param name_id:
          :param new_id:
          :param encrypted_id:
          :param new_encrypted_id:
          :param terminate:
          :return:
          """
          kwargs = self.message_args(message_id)
  
          if name_id:
              kwargs["name_id"] = name_id
          elif encrypted_id:
              kwargs["encrypted_id"] = encrypted_id
          else:
              raise AttributeError(
                  "One of NameID or EncryptedNameID has to be provided")
  
          if new_id:
              kwargs["new_id"] = new_id
          elif new_encrypted_id:
              kwargs["new_encrypted_id"] = new_encrypted_id
          elif terminate:
              kwargs["terminate"] = terminate
          else:
              raise AttributeError(
                  "One of NewID, NewEncryptedNameID or Terminate has to be "
                  "provided")
  
          return self._message(
              ManageNameIDRequest,
              destination,
              consent=consent,
              extensions=extensions,
              sign=sign,
              sign_alg=sign_alg,
              digest_alg=digest_alg,
              **kwargs,
          )
  
      def parse_manage_name_id_request(self, xmlstr, binding=BINDING_SOAP):
          """ Deal with a LogoutRequest
  
          :param xmlstr: The response as a xml string
          :param binding: What type of binding this message came through.
          :return: None if the reply doesn't contain a valid SAML LogoutResponse,
              otherwise the reponse if the logout was successful and None if it
              was not.
          """
  
          return self._parse_request(xmlstr, saml_request.ManageNameIDRequest,
                                     "manage_name_id_service", binding)
  
      # XXX DONE ent create > _status_response
      def create_manage_name_id_response(
          self,
          request,
          bindings=None,
          status=None,
          sign=None,
          issuer=None,
          sign_alg=None,
          digest_alg=None,
          **kwargs,
      ):
  
          rinfo = self.response_args(request, bindings)
  
          response = self._status_response(
              samlp.ManageNameIDResponse,
              issuer,
              status,
              sign,
              sign_alg=sign_alg,
              digest_alg=digest_alg,
              **rinfo,
          )
  
          logger.info("Response: %s", response)
  
          return response
  
      def parse_manage_name_id_request_response(self, string, binding=BINDING_SOAP):
          return self._parse_response(
              string,
              saml_response.ManageNameIDResponse,
              "manage_name_id_service",
              binding,
              asynchop=False,
          )
  
      # ------------------------------------------------------------------------
  
      def _parse_response(
          self,
          xmlstr,
          response_cls,
          service,
          binding,
          outstanding_certs=None,
          **kwargs,
      ):
          """ Deal with a Response
  
          :param xmlstr: The response as a xml string
          :param response_cls: What type of response it is
          :param binding: What type of binding this message came through.
          :param outstanding_certs: Certificates that belongs to me that the
                  IdP may have used to encrypt a response/assertion/..
          :param kwargs: Extra key word arguments
          :return: None if the reply doesn't contain a valid SAML Response,
              otherwise the response.
          """
  
          if self.config.accepted_time_diff:
              kwargs["timeslack"] = self.config.accepted_time_diff
  
          if "asynchop" not in kwargs:
              if binding in [BINDING_SOAP, BINDING_PAOS]:
                  kwargs["asynchop"] = False
              else:
                  kwargs["asynchop"] = True
  
          response = None
          if not xmlstr:
              return response
  
          if "return_addrs" not in kwargs:
              bindings = {
                  BINDING_SOAP,
                  BINDING_HTTP_REDIRECT,
                  BINDING_HTTP_POST,
              }
              if binding in bindings:
                  # expected return address
                  kwargs["return_addrs"] = self.config.endpoint(
                          service,
                          binding=binding,
                          context=self.entity_type)
  
          try:
              response = response_cls(self.sec, **kwargs)
          except Exception as exc:
              logger.info("%s", exc)
              raise
  
          xmlstr = self.unravel(xmlstr, binding, response_cls.msgtype)
          if not xmlstr:  # Not a valid reponse
              return None
  
          try:
              response_is_signed = False
              # Record the response signature requirement.
              require_response_signature = response.require_response_signature
              # Force the requirement that the response be signed in order to
              # force signature checking to happen so that we can know whether
              # or not the response is signed. The attribute on the response class
              # is reset to the recorded value in the finally clause below.
              response.require_response_signature = True
              response = response.loads(xmlstr, False, origxml=xmlstr)
          except SigverError as err:
              if require_response_signature:
                  logger.error("Signature Error: %s", err)
                  raise
              else:
                  # The response is not signed but a signature is not required
                  # so reset the attribute on the response class to the recorded
                  # value and attempt to consume the unpacked XML again.
                  response.require_response_signature = require_response_signature
                  response = response.loads(xmlstr, False, origxml=xmlstr)
          except UnsolicitedResponse:
              logger.error("Unsolicited response")
              raise
          except Exception as err:
              if "not well-formed" in "%s" % err:
                  logger.error("Not well-formed XML")
              raise
          else:
              response_is_signed = True
          finally:
              response.require_response_signature = require_response_signature
  
          logger.debug("XMLSTR: %s", xmlstr)
  
          if not response:
              return response
  
          keys = None
          if outstanding_certs:
              try:
                  cert = outstanding_certs[response.in_response_to]
              except KeyError:
                  keys = None
              else:
                  if not isinstance(cert, list):
                      cert = [cert]
                  keys = []
                  for _cert in cert:
                      keys.append(_cert["key"])
  
          try:
              assertions_are_signed = False
              # Record the assertions signature requirement.
              require_signature = response.require_signature
              # Force the requirement that the assertions be signed in order to
              # force signature checking to happen so that we can know whether
              # or not the assertions are signed. The attribute on the response class
              # is reset to the recorded value in the finally clause below.
              response.require_signature = True
              # Verify that the assertion is syntactically correct and the
              # signature on the assertion is correct if present.
              response.verify(keys)
          except SignatureError as err:
              if require_signature:
                  logger.error("Signature Error: %s", err)
                  raise
              else:
                  response.require_signature = require_signature
                  response.verify(keys)
          else:
              assertions_are_signed = True
          finally:
              response.require_signature = require_signature
  
          # If so configured enforce that either the response is signed
          # or the assertions within it are signed.
          if response.require_signature_or_response_signature:
              if not response_is_signed and not assertions_are_signed:
                  msg = "Neither the response nor the assertions are signed"
                  logger.error(msg)
                  raise SigverError(msg)
  
          return response
  
      # ------------------------------------------------------------------------
  
      def parse_logout_request_response(self, xmlstr, binding=BINDING_SOAP):
          return self._parse_response(xmlstr, LogoutResponse,
                                      "single_logout_service", binding)
  
      # ------------------------------------------------------------------------
  
      def parse_logout_request(self, xmlstr, binding=BINDING_SOAP):
          """ Deal with a LogoutRequest
  
          :param xmlstr: The response as a xml string
          :param binding: What type of binding this message came through.
          :return: None if the reply doesn't contain a valid SAML LogoutResponse,
              otherwise the reponse if the logout was successful and None if it
              was not.
          """
  
          return self._parse_request(xmlstr, saml_request.LogoutRequest,
                                     "single_logout_service", binding)
  
      def use_artifact(self, message, endpoint_index=0):
          """
  
          :param message:
          :param endpoint_index:
          :return:
          """
          message_handle = sha1(str(message).encode('utf-8'))
          message_handle.update(rndbytes())
          mhd = message_handle.digest()
          saml_art = create_artifact(self.config.entityid, mhd, endpoint_index)
          self.artifact[saml_art] = message
          return saml_art
  
      def artifact2destination(self, artifact, descriptor):
          """
          Translate an artifact into a receiver location
  
          :param artifact: The Base64 encoded SAML artifact
          :return:
          """
  
          _art = base64.b64decode(artifact)
  
          typecode = _art[:2]
          if typecode != ARTIFACT_TYPECODE:
              raise ValueError(
                  "Invalid artifact typecode '{invalid}' should be {valid}".format(
                      invalid=typecode, valid=ARTIFACT_TYPECODE
                  )
              )
  
          try:
              endpoint_index = str(int(_art[2:4]))
          except ValueError:
              endpoint_index = str(int(hexlify(_art[2:4])))
          entity = self.sourceid[_art[4:24]]
  
          destination = None
          for desc in entity["%s_descriptor" % descriptor]:
              for srv in desc["artifact_resolution_service"]:
                  if srv["index"] == endpoint_index:
                      destination = srv["location"]
                      break
  
          return destination
  
      # XXX DONE uses sign but not a create_*
      def artifact2message(
          self,
          artifact,
          descriptor,
          sign=None,
          sign_alg=None,
          digest_alg=None,
      ):
          """
  
          :param artifact: The Base64 encoded SAML artifact as sent over the net
          :param descriptor: The type of entity on the other side
          :param sign: Whether ArtifactResolve should be signed or not
          :return: A SAML message (request/response)
          """
  
          destination = self.artifact2destination(artifact, descriptor)
  
          if not destination:
              raise SAMLError("Missing endpoint location")
  
          _sid = sid()
          mid, msg = self.create_artifact_resolve(
              artifact,
              destination,
              _sid,
              sign=sign,
              sign_alg=sign_alg,
              digest_alg=digest_alg,
          )
          return self.send_using_soap(msg, destination)
  
      def parse_artifact_resolve(self, txt, **kwargs):
          """
          Always done over SOAP
  
          :param txt: The SOAP enveloped ArtifactResolve
          :param kwargs:
          :return: An ArtifactResolve instance
          """
  
          _resp = parse_soap_enveloped_saml_artifact_resolve(txt)
          return artifact_resolve_from_string(_resp)
  
      def parse_artifact_resolve_response(self, xmlstr):
          kwargs = {"entity_id": self.config.entityid,
                    "attribute_converters": self.config.attribute_converters}
  
          resp = self._parse_response(xmlstr, saml_response.ArtifactResponse,
                                      "artifact_resolve", BINDING_SOAP,
                                      **kwargs)
          # should just be one
          elems = extension_elements_to_elements(resp.response.extension_elements,
                                                 [samlp, saml])
          return elems[0]
  