Files
deb-python-pysaml2/src/saml2/server.py
2014-03-19 15:16:07 +01:00

686 lines
27 KiB
Python

#!/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 <Response> 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):
# ----------------------------------------
# <ecp:Response
# ----------------------------------------
ecp_response = ecp.Response(assertion_consumer_service_url=acs_url)
header = soapenv.Header()
header.extension_elements = [element_to_extension_element(ecp_response)]
# ----------------------------------------
# <samlp:Response
# ----------------------------------------
response = self.create_authn_response(identity, in_response_to,
destination, sp_entity_id,
name_id_policy, userid, name_id,
authn, issuer,
sign_response, sign_assertion)
body = soapenv.Body()
body.extension_elements = [element_to_extension_element(response)]
soap_envelope = soapenv.Envelope(header=header, body=body)
return "%s" % soap_envelope