Files
deb-python-pysaml2/src/saml2/s2repoze/plugins/sp.py
Roland Hedberg c78a93298c Slowly moving from six to future.backports
pycryptodomex from pypi now constructs Cryptodome module on OS X too.
2016-03-09 09:31:46 +01:00

669 lines
24 KiB
Python

#
"""
A plugin that allows you to use SAML2 SSO as authentication
and SAML2 attribute aggregations as metadata collector in your
WSGI application.
"""
import logging
import sys
import platform
import shelve
import traceback
import saml2
import six
from saml2.samlp import Extensions
from saml2 import xmldsig as ds
from future.backports.urllib.parse import parse_qs
from future.backports.urllib.parse import urlparse
from six import StringIO
from paste.httpexceptions import HTTPSeeOther, HTTPRedirection
from paste.httpexceptions import HTTPNotImplemented
from paste.httpexceptions import HTTPInternalServerError
from paste.request import parse_dict_querystring
from paste.request import construct_url
from saml2.extension.pefim import SPCertEnc
from saml2.httputil import SeeOther
from saml2.client_base import ECP_SERVICE
from zope.interface import implementer
from repoze.who.interfaces import IChallenger, IIdentifier, IAuthenticator
from repoze.who.interfaces import IMetadataProvider
from saml2 import ecp, BINDING_HTTP_REDIRECT, element_to_extension_element
from saml2 import BINDING_HTTP_POST
from saml2.client import Saml2Client
from saml2.ident import code, decode
from saml2.s_utils import sid
from saml2.config import config_factory
from saml2.profile import paos
# from saml2.population import Population
#from saml2.attribute_resolver import AttributeResolver
logger = logging.getLogger(__name__)
PAOS_HEADER_INFO = 'ver="%s";"%s"' % (paos.NAMESPACE, ECP_SERVICE)
def construct_came_from(environ):
""" The URL that the user used when the process where interupted
for single-sign-on processing. """
came_from = environ.get("PATH_INFO")
qstr = environ.get("QUERY_STRING", "")
if qstr:
came_from += '?' + qstr
return came_from
def exception_trace(tag, exc, log):
message = traceback.format_exception(*sys.exc_info())
log.error("[%s] ExcList: %s" % (tag, "".join(message),))
log.error("[%s] Exception: %s" % (tag, exc))
class ECP_response(object):
code = 200
title = 'OK'
def __init__(self, content):
self.content = content
#noinspection PyUnusedLocal
def __call__(self, environ, start_response):
start_response('%s %s' % (self.code, self.title),
[('Content-Type', "text/xml")])
return [self.content]
@implementer(IChallenger, IIdentifier, IAuthenticator, IMetadataProvider)
class SAML2Plugin(object):
def __init__(self, rememberer_name, config, saml_client, wayf, cache,
sid_store=None, discovery="", idp_query_param="",
sid_store_cert=None, ):
self.rememberer_name = rememberer_name
self.wayf = wayf
self.saml_client = saml_client
self.conf = config
self.cache = cache
self.discosrv = discovery
self.idp_query_param = idp_query_param
self.logout_endpoints = [urlparse(ep)[2] for ep in config.endpoint(
"single_logout_service")]
try:
self.metadata = self.conf.metadata
except KeyError:
self.metadata = None
if sid_store:
self.outstanding_queries = shelve.open(sid_store, writeback=True,
protocol=2)
else:
self.outstanding_queries = {}
if sid_store_cert:
self.outstanding_certs = shelve.open(sid_store_cert, writeback=True,
protocol=2)
else:
self.outstanding_certs = {}
self.iam = platform.node()
def _get_rememberer(self, environ):
rememberer = environ['repoze.who.plugins'][self.rememberer_name]
return rememberer
#### IIdentifier ####
def remember(self, environ, identity):
rememberer = self._get_rememberer(environ)
return rememberer.remember(environ, identity)
#### IIdentifier ####
def forget(self, environ, identity):
rememberer = self._get_rememberer(environ)
return rememberer.forget(environ, identity)
def _get_post(self, environ):
"""
Get the posted information
:param environ: A dictionary with environment variables
"""
body = ''
try:
length = int(environ.get('CONTENT_LENGTH', '0'))
except ValueError:
length = 0
if length != 0:
body = environ['wsgi.input'].read(length) # get the POST variables
environ[
's2repoze.body'] = body # store the request body for later
# use by pysaml2
environ['wsgi.input'] = StringIO(body) # restore the request body
# as a stream so that everything seems untouched
post = parse_qs(body) # parse the POST fields into a dict
logger.debug('identify post: %s', post)
return post
def _wayf_redirect(self, came_from):
sid_ = sid()
self.outstanding_queries[sid_] = came_from
logger.info("Redirect to WAYF function: %s", self.wayf)
return -1, HTTPSeeOther(headers=[('Location',
"%s?%s" % (self.wayf, sid_))])
#noinspection PyUnusedLocal
def _pick_idp(self, environ, came_from):
"""
If more than one idp and if none is selected, I have to do wayf or
disco
"""
# check headers to see if it's an ECP request
# headers = {
# 'Accept' : 'text/html; application/vnd.paos+xml',
# 'PAOS' : 'ver="%s";"%s"' % (paos.NAMESPACE,
# SERVICE)
# }
_cli = self.saml_client
logger.info("[_pick_idp] %s", environ)
if "HTTP_PAOS" in environ:
if environ["HTTP_PAOS"] == PAOS_HEADER_INFO:
if 'application/vnd.paos+xml' in environ["HTTP_ACCEPT"]:
# Where should I redirect the user to
# entityid -> the IdP to use
# relay_state -> when back from authentication
logger.info("- ECP client detected -")
_relay_state = construct_came_from(environ)
_entityid = _cli.config.ecp_endpoint(environ["REMOTE_ADDR"])
if not _entityid:
return -1, HTTPInternalServerError(
detail="No IdP to talk to")
logger.info("IdP to talk to: %s", _entityid)
return ecp.ecp_auth_request(_cli, _entityid,
_relay_state)
else:
return -1, HTTPInternalServerError(
detail='Faulty Accept header')
else:
return -1, HTTPInternalServerError(
detail='unknown ECP version')
idps = self.metadata.with_descriptor("idpsso")
logger.info("IdP URL: %s", idps)
idp_entity_id = query = None
for key in ['s2repoze.body', "QUERY_STRING"]:
query = environ.get(key)
if query:
try:
_idp_entity_id = dict(parse_qs(query))[
self.idp_query_param][0]
if _idp_entity_id in idps:
idp_entity_id = _idp_entity_id
break
except KeyError:
logger.debug("No IdP entity ID in query: %s", query)
pass
if idp_entity_id is None:
if len(idps) == 1:
# idps is a dictionary
idp_entity_id = idps.keys()[0]
elif not len(idps):
return -1, HTTPInternalServerError(detail='Misconfiguration')
else:
idp_entity_id = ""
logger.info("ENVIRON: %s", environ)
if self.wayf:
if query:
try:
wayf_selected = dict(parse_qs(query))[
"wayf_selected"][0]
except KeyError:
return self._wayf_redirect(came_from)
idp_entity_id = wayf_selected
else:
return self._wayf_redirect(came_from)
elif self.discosrv:
if query:
idp_entity_id = _cli.parse_discovery_service_response(
query=environ.get("QUERY_STRING"))
else:
sid_ = sid()
self.outstanding_queries[sid_] = came_from
logger.debug("Redirect to Discovery Service function")
eid = _cli.config.entityid
ret = _cli.config.getattr(
"endpoints", "sp")["discovery_response"][0][0]
ret += "?sid=%s" % sid_
loc = _cli.create_discovery_service_request(
self.discosrv, eid, **{"return": ret})
return -1, SeeOther(loc)
else:
return -1, HTTPNotImplemented(
detail='No WAYF or DJ present!')
logger.info("Chosen IdP: '%s'", idp_entity_id)
return 0, idp_entity_id
#### IChallenger ####
#noinspection PyUnusedLocal
def challenge(self, environ, _status, _app_headers, _forget_headers):
_cli = self.saml_client
if 'REMOTE_USER' in environ:
name_id = decode(environ["REMOTE_USER"])
_cli = self.saml_client
path_info = environ['PATH_INFO']
if 'samlsp.logout' in environ:
responses = _cli.global_logout(name_id)
return self._handle_logout(responses)
if 'samlsp.pending' in environ:
response = environ['samlsp.pending']
if isinstance(response, HTTPRedirection):
response.headers += _forget_headers
return response
#logger = environ.get('repoze.who.logger','')
# Which page was accessed to get here
came_from = construct_came_from(environ)
environ["myapp.came_from"] = came_from
logger.debug("[sp.challenge] RelayState >> '%s'", came_from)
# Am I part of a virtual organization or more than one ?
try:
vorg_name = environ["myapp.vo"]
except KeyError:
try:
vorg_name = _cli.vorg._name
except AttributeError:
vorg_name = ""
logger.info("[sp.challenge] VO: %s", vorg_name)
# If more than one idp and if none is selected, I have to do wayf
(done, response) = self._pick_idp(environ, came_from)
# Three cases: -1 something went wrong or Discovery service used
# 0 I've got an IdP to send a request to
# >0 ECP in progress
logger.debug("_idp_pick returned: %s", done)
if done == -1:
return response
elif done > 0:
self.outstanding_queries[done] = came_from
return ECP_response(response)
else:
entity_id = response
logger.info("[sp.challenge] entity_id: %s", entity_id)
# Do the AuthnRequest
_binding = BINDING_HTTP_REDIRECT
try:
srvs = _cli.metadata.single_sign_on_service(entity_id, _binding)
logger.debug("srvs: %s", srvs)
dest = srvs[0]["location"]
logger.debug("destination: %s", dest)
extensions = None
cert = None
if _cli.config.generate_cert_func is not None:
cert_str, req_key_str = _cli.config.generate_cert_func()
cert = {
"cert": cert_str,
"key": req_key_str
}
spcertenc = SPCertEnc(x509_data=ds.X509Data(
x509_certificate=ds.X509Certificate(text=cert_str)))
extensions = Extensions(extension_elements=[
element_to_extension_element(spcertenc)])
if _cli.authn_requests_signed:
_sid = saml2.s_utils.sid()
req_id, msg_str = _cli.create_authn_request(
dest, vorg=vorg_name, sign=_cli.authn_requests_signed,
message_id=_sid, extensions=extensions)
_sid = req_id
else:
req_id, req = _cli.create_authn_request(
dest, vorg=vorg_name, sign=False, extensions=extensions)
msg_str = "%s" % req
_sid = req_id
if cert is not None:
self.outstanding_certs[_sid] = cert
ht_args = _cli.apply_binding(_binding, msg_str,
destination=dest,
relay_state=came_from)
logger.debug("ht_args: %s", ht_args)
except Exception as exc:
logger.exception(exc)
raise Exception(
"Failed to construct the AuthnRequest: %s" % exc)
try:
ret = _cli.config.getattr(
"endpoints", "sp")["discovery_response"][0][0]
if (environ["PATH_INFO"]) in ret and ret.split(
environ["PATH_INFO"])[1] == "":
query = parse_qs(environ["QUERY_STRING"])
sid = query["sid"][0]
came_from = self.outstanding_queries[sid]
except:
pass
# remember the request
self.outstanding_queries[_sid] = came_from
if not ht_args["data"] and ht_args["headers"][0][0] == "Location":
logger.debug('redirect to: %s', ht_args["headers"][0][1])
return HTTPSeeOther(headers=ht_args["headers"])
else:
return ht_args["data"]
def _construct_identity(self, session_info):
cni = code(session_info["name_id"])
identity = {
"login": cni,
"password": "",
'repoze.who.userid': cni,
"user": session_info["ava"],
}
logger.debug("Identity: %s", identity)
return identity
def _eval_authn_response(self, environ, post, binding=BINDING_HTTP_POST):
logger.info("Got AuthN response, checking..")
logger.info("Outstanding: %s", self.outstanding_queries)
try:
# Evaluate the response, returns a AuthnResponse instance
try:
authresp = self.saml_client.parse_authn_request_response(
post["SAMLResponse"][0], binding, self.outstanding_queries,
self.outstanding_certs)
except Exception as excp:
logger.exception("Exception: %s" % (excp,))
raise
session_info = authresp.session_info()
except TypeError as excp:
logger.exception("Exception: %s" % (excp,))
return None
if session_info["came_from"]:
logger.debug("came_from << %s", session_info["came_from"])
try:
path, query = session_info["came_from"].split('?')
environ["PATH_INFO"] = path
environ["QUERY_STRING"] = query
except ValueError:
environ["PATH_INFO"] = session_info["came_from"]
logger.info("Session_info: %s", session_info)
return session_info
def do_ecp_response(self, body, environ):
response, _relay_state = ecp.handle_ecp_authn_response(self.saml_client,
body)
environ["s2repoze.relay_state"] = _relay_state.text
session_info = response.session_info()
logger.info("Session_info: %s", session_info)
return session_info
#### IIdentifier ####
def identify(self, environ):
"""
Tries to do the identification
"""
#logger = environ.get('repoze.who.logger', '')
query = parse_dict_querystring(environ)
if ("CONTENT_LENGTH" not in environ or not environ[
"CONTENT_LENGTH"]) and \
"SAMLResponse" not in query and "SAMLRequest" not in \
query:
logger.debug('[identify] get or empty post')
return None
# if logger:
# logger.info("ENVIRON: %s", environ)
# logger.info("self: %s", self.__dict__)
uri = environ.get('REQUEST_URI', construct_url(environ))
logger.debug('[sp.identify] uri: %s', uri)
query = parse_dict_querystring(environ)
logger.debug('[sp.identify] query: %s', query)
if "SAMLResponse" in query or "SAMLRequest" in query:
post = query
binding = BINDING_HTTP_REDIRECT
else:
post = self._get_post(environ)
binding = BINDING_HTTP_POST
try:
logger.debug('[sp.identify] post keys: %s', post.keys())
except (TypeError, IndexError):
pass
try:
path_info = environ['PATH_INFO']
logout = False
if path_info in self.logout_endpoints:
logout = True
if logout and "SAMLRequest" in post:
print("logout request received")
try:
response = self.saml_client.handle_logout_request(
post["SAMLRequest"][0],
self.saml_client.users.subjects()[0], binding)
environ['samlsp.pending'] = self._handle_logout(response)
return {}
except:
import traceback
traceback.print_exc()
elif "SAMLResponse" not in post:
logger.info("[sp.identify] --- NOT SAMLResponse ---")
# Not for me, put the post back where next in line can
# find it
environ["post.fieldstorage"] = post
# restore wsgi.input incase that is needed
# only of s2repoze.body is present
if 's2repoze.body' in environ:
environ['wsgi.input'] = StringIO(environ['s2repoze.body'])
return {}
else:
logger.info("[sp.identify] --- SAMLResponse ---")
# check for SAML2 authN response
#if self.debug:
try:
if logout:
response = \
self.saml_client.parse_logout_request_response(
post["SAMLResponse"][0], binding)
if response:
action = self.saml_client.handle_logout_response(
response)
if type(action) == dict:
request = self._handle_logout(action)
else:
#logout complete
request = HTTPSeeOther(headers=[
('Location', "/")])
if request:
environ['samlsp.pending'] = request
return {}
else:
session_info = self._eval_authn_response(
environ, post,
binding=binding)
except Exception as err:
environ["s2repoze.saml_error"] = err
return {}
except TypeError as exc:
# might be a ECP (=SOAP) response
body = environ.get('s2repoze.body', None)
if body:
# might be a ECP response
try:
session_info = self.do_ecp_response(body, environ)
except Exception as err:
environ["post.fieldstorage"] = post
environ["s2repoze.saml_error"] = err
return {}
else:
exception_trace("sp.identity", exc, logger)
environ["post.fieldstorage"] = post
return {}
if session_info:
environ["s2repoze.sessioninfo"] = session_info
return self._construct_identity(session_info)
else:
return None
# IMetadataProvider
def add_metadata(self, environ, identity):
""" Add information to the knowledge I have about the user """
name_id = identity['repoze.who.userid']
if isinstance(name_id, six.string_types):
try:
# Make sure that userids authenticated by another plugin
# don't cause problems here.
name_id = decode(name_id)
except:
pass
_cli = self.saml_client
logger.debug("[add_metadata] for %s", name_id)
try:
logger.debug("Issuers: %s", _cli.users.sources(name_id))
except KeyError:
pass
if "user" not in identity:
identity["user"] = {}
try:
(ava, _) = _cli.users.get_identity(name_id)
#now = time.gmtime()
logger.debug("[add_metadata] adds: %s", ava)
identity["user"].update(ava)
except KeyError:
pass
if "pysaml2_vo_expanded" not in identity and _cli.vorg:
# is this a Virtual Organization situation
for vo in _cli.vorg.values():
try:
if vo.do_aggregation(name_id):
# Get the extended identity
identity["user"] = _cli.users.get_identity(name_id)[0]
# Only do this once, mark that the identity has been
# expanded
identity["pysaml2_vo_expanded"] = 1
except KeyError:
logger.exception("Failed to do attribute aggregation, "
"missing common attribute")
logger.debug("[add_metadata] returns: %s", dict(identity))
if not identity["user"]:
# remove cookie and demand re-authentication
pass
# used 2 times : one to get the ticket, the other to validate it
@staticmethod
def _service_url(environ, qstr=None):
if qstr is not None:
url = construct_url(environ, querystring=qstr)
else:
url = construct_url(environ)
return url
#### IAuthenticatorPlugin ####
#noinspection PyUnusedLocal
def authenticate(self, environ, identity=None):
if identity:
if identity.get('user') and environ.get(
's2repoze.sessioninfo') and identity.get(
'user') == environ.get('s2repoze.sessioninfo').get('ava'):
return identity.get('login')
tktuser = identity.get('repoze.who.plugins.auth_tkt.userid', None)
if tktuser and self.saml_client.is_logged_in(decode(tktuser)):
return tktuser
return None
else:
return None
@staticmethod
def _handle_logout(responses):
if 'data' in responses:
ht_args = responses
else:
ht_args = responses[responses.keys()[0]][1]
if not ht_args["data"] and ht_args["headers"][0][0] == "Location":
logger.debug('redirect to: %s', ht_args["headers"][0][1])
return HTTPSeeOther(headers=ht_args["headers"])
else:
return ht_args["data"]
def make_plugin(remember_name=None, # plugin for remember
cache="", # cache
# Which virtual organization to support
virtual_organization="",
saml_conf="",
wayf="",
sid_store="",
identity_cache="",
discovery="",
idp_query_param=""
):
if saml_conf is "":
raise ValueError(
'must include saml_conf in configuration')
if remember_name is None:
raise ValueError('must include remember_name in configuration')
conf = config_factory("sp", saml_conf)
scl = Saml2Client(config=conf, identity_cache=identity_cache,
virtual_organization=virtual_organization)
plugin = SAML2Plugin(remember_name, conf, scl, wayf, cache, sid_store,
discovery, idp_query_param)
return plugin