deb-python-pysaml2/src/saml2/authn.py

268 lines
8.1 KiB
Python

import logging
import six
import time
from saml2 import SAMLError
from saml2.aes import AESCipher
from saml2.httputil import Response
from saml2.httputil import make_cookie
from saml2.httputil import Redirect
from saml2.httputil import Unauthorized
from saml2.httputil import parse_cookie
from six.moves.urllib.parse import urlencode, parse_qs, urlsplit
__author__ = 'rolandh'
logger = logging.getLogger(__name__)
class AuthnFailure(SAMLError):
pass
class EncodeError(SAMLError):
pass
class UserAuthnMethod(object):
def __init__(self, srv):
self.srv = srv
def __call__(self, *args, **kwargs):
raise NotImplemented
def authenticated_as(self, **kwargs):
raise NotImplemented
def verify(self, **kwargs):
raise NotImplemented
def is_equal(a, b):
if len(a) != len(b):
return False
result = 0
for x, y in zip(a, b):
result |= x ^ y
return result == 0
def url_encode_params(params=None):
if not isinstance(params, dict):
raise EncodeError("You must pass in a dictionary!")
params_list = []
for k, v in params.items():
if isinstance(v, list):
params_list.extend([(k, x) for x in v])
else:
params_list.append((k, v))
return urlencode(params_list)
def create_return_url(base, query, **kwargs):
"""
Add a query string plus extra parameters to a base URL which may contain
a query part already.
:param base: redirect_uri may contain a query part, no fragment allowed.
:param query: Old query part as a string
:param kwargs: extra query parameters
:return:
"""
part = urlsplit(base)
if part.fragment:
raise ValueError("Base URL contained parts it shouldn't")
for key, values in parse_qs(query).items():
if key in kwargs:
if isinstance(kwargs[key], six.string_types):
kwargs[key] = [kwargs[key]]
kwargs[key].extend(values)
else:
kwargs[key] = values
if part.query:
for key, values in parse_qs(part.query).items():
if key in kwargs:
if isinstance(kwargs[key], six.string_types):
kwargs[key] = [kwargs[key]]
kwargs[key].extend(values)
else:
kwargs[key] = values
_pre = base.split("?")[0]
else:
_pre = base
logger.debug("kwargs: %s" % kwargs)
return "%s?%s" % (_pre, url_encode_params(kwargs))
class UsernamePasswordMako(UserAuthnMethod):
"""Do user authentication using the normal username password form
using Mako as template system"""
cookie_name = "userpassmako"
def __init__(self, srv, mako_template, template_lookup, pwd, return_to):
"""
:param srv: The server instance
:param mako_template: Which Mako template to use
:param pwd: Username/password dictionary like database
:param return_to: Where to send the user after authentication
:return:
"""
UserAuthnMethod.__init__(self, srv)
self.mako_template = mako_template
self.template_lookup = template_lookup
self.passwd = pwd
self.return_to = return_to
self.active = {}
self.query_param = "upm_answer"
self.aes = AESCipher(self.srv.symkey, srv.iv)
def __call__(self, cookie=None, policy_url=None, logo_url=None,
query="", **kwargs):
"""
Put up the login form
"""
if cookie:
headers = [cookie]
else:
headers = []
resp = Response(headers=headers)
argv = {"login": "",
"password": "",
"action": "verify",
"policy_url": policy_url,
"logo_url": logo_url,
"query": query}
logger.info("do_authentication argv: %s" % argv)
mte = self.template_lookup.get_template(self.mako_template)
resp.message = mte.render(**argv)
return resp
def _verify(self, pwd, user):
assert is_equal(pwd, self.passwd[user])
def verify(self, request, **kwargs):
"""
Verifies that the given username and password was correct
:param request: Either the query part of a URL a urlencoded
body of a HTTP message or a parse such.
:param kwargs: Catch whatever else is sent.
:return: redirect back to where ever the base applications
wants the user after authentication.
"""
#logger.debug("verify(%s)" % request)
if isinstance(request, six.string_types):
_dict = parse_qs(request)
elif isinstance(request, dict):
_dict = request
else:
raise ValueError("Wrong type of input")
# verify username and password
try:
self._verify(_dict["password"][0], _dict["login"][0])
timestamp = str(int(time.mktime(time.gmtime())))
info = self.aes.encrypt("::".join([_dict["login"][0], timestamp]))
self.active[info] = timestamp
cookie = make_cookie(self.cookie_name, info, self.srv.seed)
return_to = create_return_url(self.return_to, _dict["query"][0],
**{self.query_param: "true"})
resp = Redirect(return_to, headers=[cookie])
except (AssertionError, KeyError):
resp = Unauthorized("Unknown user or wrong password")
return resp
def authenticated_as(self, cookie=None, **kwargs):
if cookie is None:
return None
else:
logger.debug("kwargs: %s" % kwargs)
try:
info, timestamp = parse_cookie(self.cookie_name,
self.srv.seed, cookie)
if self.active[info] == timestamp:
uid, _ts = self.aes.decrypt(info).split("::")
if timestamp == _ts:
return {"uid": uid}
except Exception:
pass
return None
def done(self, areq):
try:
_ = areq[self.query_param]
return False
except KeyError:
return True
class SocialService(UserAuthnMethod):
def __init__(self, social):
UserAuthnMethod.__init__(self, None)
self.social = social
def __call__(self, server_env, cookie=None, sid="", query="", **kwargs):
return self.social.begin(server_env, cookie, sid, query)
def callback(self, server_env, cookie=None, sid="", query="", **kwargs):
return self.social.callback(server_env, cookie, sid, query, **kwargs)
class AuthnMethodChooser(object):
def __init__(self, methods=None):
self.methods = methods
def __call__(self, **kwargs):
if not self.methods:
raise SAMLError("No authentication methods defined")
elif len(self.methods) == 1:
return self.methods[0]
else:
pass # TODO
try:
import ldap
class LDAPAuthn(UsernamePasswordMako):
def __init__(self, srv, ldapsrv, return_to,
dn_pattern, mako_template, template_lookup):
"""
:param srv: The server instance
:param ldapsrv: Which LDAP server to us
:param return_to: Where to send the user after authentication
:return:
"""
UsernamePasswordMako.__init__(self, srv, mako_template, template_lookup,
None, return_to)
self.ldap = ldap.initialize(ldapsrv)
self.ldap.protocol_version = 3
self.ldap.set_option(ldap.OPT_REFERRALS, 0)
self.dn_pattern = dn_pattern
def _verify(self, pwd, user):
"""
Verifies the username and password agains a LDAP server
:param pwd: The password
:param user: The username
:return: AssertionError if the LDAP verification failed.
"""
_dn = self.dn_pattern % user
try:
self.ldap.simple_bind_s(_dn, pwd)
except Exception:
raise AssertionError()
except ImportError:
class LDAPAuthn(UserAuthnMethod):
pass