Allow hs to do CAS login completely and issue the client with a login token that can be redeemed for the usual successful login response

This commit is contained in:
Steven Hammerton 2015-11-05 14:01:12 +00:00
parent 45f1827fb7
commit 414a4a71b4
3 changed files with 218 additions and 5 deletions

View File

@ -41,7 +41,7 @@ class CasConfig(Config):
#cas_config:
# enabled: true
# server_url: "https://cas-server.com"
# ticket_redirect_url: "https://homesever.domain.com:8448"
# service_url: "https://homesever.domain.com:8448"
# #required_attributes:
# # name: value
"""

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@ -18,7 +18,7 @@ from twisted.internet import defer
from ._base import BaseHandler
from synapse.api.constants import LoginType
from synapse.types import UserID
from synapse.api.errors import LoginError, Codes
from synapse.api.errors import AuthError, LoginError, Codes
from synapse.util.async import run_on_reactor
from twisted.web.client import PartialDownloadError
@ -46,6 +46,13 @@ class AuthHandler(BaseHandler):
}
self.bcrypt_rounds = hs.config.bcrypt_rounds
self.sessions = {}
self.INVALID_TOKEN_HTTP_STATUS = 401
self._KNOWN_CAVEAT_PREFIXES = set([
"gen = ",
"type = ",
"time < ",
"user_id = ",
])
@defer.inlineCallbacks
def check_auth(self, flows, clientdict, clientip):
@ -297,10 +304,11 @@ class AuthHandler(BaseHandler):
defer.returnValue((user_id, access_token, refresh_token))
@defer.inlineCallbacks
def login_with_cas_user_id(self, user_id):
def login_with_user_id(self, user_id):
"""
Authenticates the user with the given user ID,
intended to have been captured from a CAS response
it is intended that the authentication of the user has
already been verified by other mechanism (e.g. CAS)
Args:
user_id (str): User ID
@ -393,6 +401,17 @@ class AuthHandler(BaseHandler):
))
return m.serialize()
def generate_short_term_login_token(self, user_id):
macaroon = self._generate_base_macaroon(user_id)
macaroon.add_first_party_caveat("type = login")
now = self.hs.get_clock().time_msec()
expiry = now + (2 * 60 * 1000)
macaroon.add_first_party_caveat("time < %d" % (expiry,))
return macaroon.serialize()
def validate_short_term_login_token_and_get_user_id(self, login_token):
return self._validate_macaroon_and_get_user_id(login_token, "login", True)
def _generate_base_macaroon(self, user_id):
macaroon = pymacaroons.Macaroon(
location=self.hs.config.server_name,
@ -402,6 +421,57 @@ class AuthHandler(BaseHandler):
macaroon.add_first_party_caveat("user_id = %s" % (user_id,))
return macaroon
def _validate_macaroon_and_get_user_id(self, macaroon_str,
macaroon_type, validate_expiry):
try:
macaroon = pymacaroons.Macaroon.deserialize(macaroon_str)
user_id = self._get_user_from_macaroon(macaroon)
v = pymacaroons.Verifier()
v.satisfy_exact("gen = 1")
v.satisfy_exact("type = " + macaroon_type)
v.satisfy_exact("user_id = " + user_id)
if validate_expiry:
v.satisfy_general(self._verify_expiry)
v.verify(macaroon, self.hs.config.macaroon_secret_key)
v = pymacaroons.Verifier()
v.satisfy_general(self._verify_recognizes_caveats)
v.verify(macaroon, self.hs.config.macaroon_secret_key)
return user_id
except (pymacaroons.exceptions.MacaroonException, TypeError, ValueError):
raise AuthError(
self.INVALID_TOKEN_HTTP_STATUS, "Invalid token",
errcode=Codes.UNKNOWN_TOKEN
)
def _get_user_from_macaroon(self, macaroon):
user_prefix = "user_id = "
for caveat in macaroon.caveats:
if caveat.caveat_id.startswith(user_prefix):
return caveat.caveat_id[len(user_prefix):]
raise AuthError(
self.INVALID_TOKEN_HTTP_STATUS, "No user_id found in token",
errcode=Codes.UNKNOWN_TOKEN
)
def _verify_expiry(self, caveat):
prefix = "time < "
if not caveat.startswith(prefix):
return False
expiry = int(caveat[len(prefix):])
now = self.hs.get_clock().time_msec()
return now < expiry
def _verify_recognizes_caveats(self, caveat):
first_space = caveat.find(" ")
if first_space < 0:
return False
second_space = caveat.find(" ", first_space + 1)
if second_space < 0:
return False
return caveat[:second_space + 1] in self._KNOWN_CAVEAT_PREFIXES
@defer.inlineCallbacks
def set_password(self, user_id, newpassword):
password_hash = self.hash(newpassword)

View File

@ -22,6 +22,7 @@ from base import ClientV1RestServlet, client_path_pattern
import simplejson as json
import urllib
import urlparse
import logging
from saml2 import BINDING_HTTP_POST
@ -39,6 +40,7 @@ class LoginRestServlet(ClientV1RestServlet):
PASS_TYPE = "m.login.password"
SAML2_TYPE = "m.login.saml2"
CAS_TYPE = "m.login.cas"
TOKEN_TYPE = "m.login.token"
def __init__(self, hs):
super(LoginRestServlet, self).__init__(hs)
@ -58,6 +60,7 @@ class LoginRestServlet(ClientV1RestServlet):
flows.append({"type": LoginRestServlet.CAS_TYPE})
if self.password_enabled:
flows.append({"type": LoginRestServlet.PASS_TYPE})
flows.append({"type": LoginRestServlet.TOKEN_TYPE})
return (200, {"flows": flows})
def on_OPTIONS(self, request):
@ -83,6 +86,7 @@ class LoginRestServlet(ClientV1RestServlet):
"uri": "%s%s" % (self.idp_redirect_url, relay_state)
}
defer.returnValue((200, result))
# TODO Delete this after all CAS clients switch to token login instead
elif self.cas_enabled and (login_submission["type"] ==
LoginRestServlet.CAS_TYPE):
# TODO: get this from the homeserver rather than creating a new one for
@ -96,6 +100,9 @@ class LoginRestServlet(ClientV1RestServlet):
body = yield http_client.get_raw(uri, args)
result = yield self.do_cas_login(body)
defer.returnValue(result)
elif login_submission["type"] == LoginRestServlet.TOKEN_TYPE:
result = yield self.do_token_login(login_submission)
defer.returnValue(result)
else:
raise SynapseError(400, "Bad login type.")
except KeyError:
@ -131,6 +138,26 @@ class LoginRestServlet(ClientV1RestServlet):
defer.returnValue((200, result))
@defer.inlineCallbacks
def do_token_login(self, login_submission):
token = login_submission['token']
auth_handler = self.handlers.auth_handler
user_id = (
yield auth_handler.validate_short_term_login_token_and_get_user_id(token)
)
user_id, access_token, refresh_token = (
yield auth_handler.login_with_user_id(user_id)
)
result = {
"user_id": user_id, # may have changed
"access_token": access_token,
"refresh_token": refresh_token,
"home_server": self.hs.hostname,
}
defer.returnValue((200, result))
# TODO Delete this after all CAS clients switch to token login instead
@defer.inlineCallbacks
def do_cas_login(self, cas_response_body):
user, attributes = self.parse_cas_response(cas_response_body)
@ -152,7 +179,7 @@ class LoginRestServlet(ClientV1RestServlet):
user_exists = yield auth_handler.does_user_exist(user_id)
if user_exists:
user_id, access_token, refresh_token = (
yield auth_handler.login_with_cas_user_id(user_id)
yield auth_handler.login_with_user_id(user_id)
)
result = {
"user_id": user_id, # may have changed
@ -173,6 +200,7 @@ class LoginRestServlet(ClientV1RestServlet):
defer.returnValue((200, result))
# TODO Delete this after all CAS clients switch to token login instead
def parse_cas_response(self, cas_response_body):
root = ET.fromstring(cas_response_body)
if not root.tag.endswith("serviceResponse"):
@ -243,6 +271,7 @@ class SAML2RestServlet(ClientV1RestServlet):
defer.returnValue((200, {"status": "not_authenticated"}))
# TODO Delete this after all CAS clients switch to token login instead
class CasRestServlet(ClientV1RestServlet):
PATTERN = client_path_pattern("/login/cas")
@ -254,6 +283,118 @@ class CasRestServlet(ClientV1RestServlet):
return (200, {"serverUrl": self.cas_server_url})
class CasRedirectServlet(ClientV1RestServlet):
PATTERN = client_path_pattern("/login/cas/redirect")
def __init__(self, hs):
super(CasRedirectServlet, self).__init__(hs)
self.cas_server_url = hs.config.cas_server_url
self.cas_service_url = hs.config.cas_service_url
def on_GET(self, request):
args = request.args
if "redirectUrl" not in args:
return (400, "Redirect URL not specified for CAS auth")
clientRedirectUrlParam = urllib.urlencode({
"redirectUrl": args["redirectUrl"][0]
})
hsRedirectUrl = self.cas_service_url + "/_matrix/client/api/v1/login/cas/ticket"
serviceParam = urllib.urlencode({
"service": "%s?%s" % (hsRedirectUrl, clientRedirectUrlParam)
})
request.redirect("%s?%s" % (self.cas_server_url, serviceParam))
request.finish()
defer.returnValue(None)
class CasTicketServlet(ClientV1RestServlet):
PATTERN = client_path_pattern("/login/cas/ticket")
def __init__(self, hs):
super(CasTicketServlet, self).__init__(hs)
self.cas_server_url = hs.config.cas_server_url
self.cas_service_url = hs.config.cas_service_url
self.cas_required_attributes = hs.config.cas_required_attributes
@defer.inlineCallbacks
def on_GET(self, request):
clientRedirectUrl = request.args["redirectUrl"][0]
# TODO: get this from the homeserver rather than creating a new one for
# each request
http_client = SimpleHttpClient(self.hs)
uri = self.cas_server_url + "/proxyValidate"
args = {
"ticket": request.args["ticket"],
"service": self.cas_service_url
}
body = yield http_client.get_raw(uri, args)
result = yield self.handle_cas_response(request, body, clientRedirectUrl)
defer.returnValue(result)
@defer.inlineCallbacks
def handle_cas_response(self, request, cas_response_body, clientRedirectUrl):
user, attributes = self.parse_cas_response(cas_response_body)
for required_attribute, required_value in self.cas_required_attributes.items():
# If required attribute was not in CAS Response - Forbidden
if required_attribute not in attributes:
raise LoginError(401, "Unauthorized", errcode=Codes.UNAUTHORIZED)
# Also need to check value
if required_value is not None:
actual_value = attributes[required_attribute]
# If required attribute value does not match expected - Forbidden
if required_value != actual_value:
raise LoginError(401, "Unauthorized", errcode=Codes.UNAUTHORIZED)
user_id = UserID.create(user, self.hs.hostname).to_string()
auth_handler = self.handlers.auth_handler
user_exists = yield auth_handler.does_user_exist(user_id)
if not user_exists:
user_id, ignored = (
yield self.handlers.registration_handler.register(localpart=user)
)
login_token = auth_handler.generate_short_term_login_token(user_id)
redirectUrl = self.add_login_token_to_redirect_url(clientRedirectUrl, login_token)
request.redirect(redirectUrl)
request.finish()
defer.returnValue(None)
def add_login_token_to_redirect_url(self, url, token):
url_parts = list(urlparse.urlparse(url))
query = dict(urlparse.parse_qsl(url_parts[4]))
query.update({"loginToken": token})
url_parts[4] = urllib.urlencode(query)
return urlparse.urlunparse(url_parts)
def parse_cas_response(self, cas_response_body):
root = ET.fromstring(cas_response_body)
if not root.tag.endswith("serviceResponse"):
raise LoginError(401, "Invalid CAS response", errcode=Codes.UNAUTHORIZED)
if not root[0].tag.endswith("authenticationSuccess"):
raise LoginError(401, "Unsuccessful CAS response", errcode=Codes.UNAUTHORIZED)
for child in root[0]:
if child.tag.endswith("user"):
user = child.text
if child.tag.endswith("attributes"):
attributes = {}
for attribute in child:
# ElementTree library expands the namespace in attribute tags
# to the full URL of the namespace.
# See (https://docs.python.org/2/library/xml.etree.elementtree.html)
# We don't care about namespace here and it will always be encased in
# curly braces, so we remove them.
if "}" in attribute.tag:
attributes[attribute.tag.split("}")[1]] = attribute.text
else:
attributes[attribute.tag] = attribute.text
if user is None or attributes is None:
raise LoginError(401, "Invalid CAS response", errcode=Codes.UNAUTHORIZED)
return (user, attributes)
def _parse_json(request):
try:
content = json.loads(request.content.read())
@ -269,5 +410,7 @@ def register_servlets(hs, http_server):
if hs.config.saml2_enabled:
SAML2RestServlet(hs).register(http_server)
if hs.config.cas_enabled:
CasRedirectServlet(hs).register(http_server)
CasTicketServlet(hs).register(http_server)
CasRestServlet(hs).register(http_server)
# TODO PasswordResetRestServlet(hs).register(http_server)