diff --git a/changelog.d/5422.feature b/changelog.d/5422.feature new file mode 100644 index 0000000000..02ac25a2f4 --- /dev/null +++ b/changelog.d/5422.feature @@ -0,0 +1 @@ +Fully support SAML2 authentication. Contributed by [Alexander Trost](https://github.com/galexrt) - thank you! diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index bf9cd88b15..7fe7c94ac4 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -997,6 +997,12 @@ signing_key_path: "CONFDIR/SERVERNAME.signing.key" # so it is not normally necessary to specify them unless you need to # override them. # +# Once SAML support is enabled, a metadata file will be exposed at +# https://:/_matrix/saml2/metadata.xml, which you may be able to +# use to configure your SAML IdP with. Alternatively, you can manually configure +# the IdP to use an ACS location of +# https://:/_matrix/saml2/authn_response. +# #saml2_config: # sp_config: # # point this to the IdP's metadata. You can use either a local file or @@ -1006,7 +1012,15 @@ signing_key_path: "CONFDIR/SERVERNAME.signing.key" # remote: # - url: https://our_idp/metadata.xml # -# # The rest of sp_config is just used to generate our metadata xml, and you +# # By default, the user has to go to our login page first. If you'd like to +# # allow IdP-initiated login, set 'allow_unsolicited: True' in a +# # 'service.sp' section: +# # +# #service: +# # sp: +# # allow_unsolicited: True +# +# # The examples below are just used to generate our metadata xml, and you # # may well not need it, depending on your setup. Alternatively you # # may need a whole lot more detail - see the pysaml2 docs! # @@ -1029,6 +1043,12 @@ signing_key_path: "CONFDIR/SERVERNAME.signing.key" # # separate pysaml2 configuration file: # # # config_path: "CONFDIR/sp_conf.py" +# +# # the lifetime of a SAML session. This defines how long a user has to +# # complete the authentication process, if allow_unsolicited is unset. +# # The default is 5 minutes. +# # +# # saml_session_lifetime: 5m diff --git a/synapse/config/saml2_config.py b/synapse/config/saml2_config.py index 872a1ba934..6a8161547a 100644 --- a/synapse/config/saml2_config.py +++ b/synapse/config/saml2_config.py @@ -12,6 +12,7 @@ # 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. +from synapse.python_dependencies import DependencyException, check_requirements from ._base import Config, ConfigError @@ -25,6 +26,11 @@ class SAML2Config(Config): if not saml2_config or not saml2_config.get("enabled", True): return + try: + check_requirements("saml2") + except DependencyException as e: + raise ConfigError(e.message) + self.saml2_enabled = True import saml2.config @@ -37,6 +43,11 @@ class SAML2Config(Config): if config_path is not None: self.saml2_sp_config.load_file(config_path) + # session lifetime: in milliseconds + self.saml2_session_lifetime = self.parse_duration( + saml2_config.get("saml_session_lifetime", "5m") + ) + def _default_saml_config_dict(self): import saml2 @@ -72,6 +83,12 @@ class SAML2Config(Config): # so it is not normally necessary to specify them unless you need to # override them. # + # Once SAML support is enabled, a metadata file will be exposed at + # https://:/_matrix/saml2/metadata.xml, which you may be able to + # use to configure your SAML IdP with. Alternatively, you can manually configure + # the IdP to use an ACS location of + # https://:/_matrix/saml2/authn_response. + # #saml2_config: # sp_config: # # point this to the IdP's metadata. You can use either a local file or @@ -81,7 +98,15 @@ class SAML2Config(Config): # remote: # - url: https://our_idp/metadata.xml # - # # The rest of sp_config is just used to generate our metadata xml, and you + # # By default, the user has to go to our login page first. If you'd like to + # # allow IdP-initiated login, set 'allow_unsolicited: True' in a + # # 'service.sp' section: + # # + # #service: + # # sp: + # # allow_unsolicited: True + # + # # The examples below are just used to generate our metadata xml, and you # # may well not need it, depending on your setup. Alternatively you # # may need a whole lot more detail - see the pysaml2 docs! # @@ -104,6 +129,12 @@ class SAML2Config(Config): # # separate pysaml2 configuration file: # # # config_path: "%(config_dir_path)s/sp_conf.py" + # + # # the lifetime of a SAML session. This defines how long a user has to + # # complete the authentication process, if allow_unsolicited is unset. + # # The default is 5 minutes. + # # + # # saml_session_lifetime: 5m """ % { "config_dir_path": config_dir_path } diff --git a/synapse/handlers/saml_handler.py b/synapse/handlers/saml_handler.py new file mode 100644 index 0000000000..a1ce6929cf --- /dev/null +++ b/synapse/handlers/saml_handler.py @@ -0,0 +1,123 @@ +# -*- coding: utf-8 -*- +# Copyright 2019 The Matrix.org Foundation C.I.C. +# +# 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. +import logging + +import attr +import saml2 +from saml2.client import Saml2Client + +from synapse.api.errors import SynapseError +from synapse.http.servlet import parse_string +from synapse.rest.client.v1.login import SSOAuthHandler + +logger = logging.getLogger(__name__) + + +class SamlHandler: + def __init__(self, hs): + self._saml_client = Saml2Client(hs.config.saml2_sp_config) + self._sso_auth_handler = SSOAuthHandler(hs) + + # a map from saml session id to Saml2SessionData object + self._outstanding_requests_dict = {} + + self._clock = hs.get_clock() + self._saml2_session_lifetime = hs.config.saml2_session_lifetime + + def handle_redirect_request(self, client_redirect_url): + """Handle an incoming request to /login/sso/redirect + + Args: + client_redirect_url (bytes): the URL that we should redirect the + client to when everything is done + + Returns: + bytes: URL to redirect to + """ + reqid, info = self._saml_client.prepare_for_authenticate( + relay_state=client_redirect_url + ) + + now = self._clock.time_msec() + self._outstanding_requests_dict[reqid] = Saml2SessionData(creation_time=now) + + for key, value in info["headers"]: + if key == "Location": + return value + + # this shouldn't happen! + raise Exception("prepare_for_authenticate didn't return a Location header") + + def handle_saml_response(self, request): + """Handle an incoming request to /_matrix/saml2/authn_response + + Args: + request (SynapseRequest): the incoming request from the browser. We'll + respond to it with a redirect. + + Returns: + Deferred[none]: Completes once we have handled the request. + """ + resp_bytes = parse_string(request, "SAMLResponse", required=True) + relay_state = parse_string(request, "RelayState", required=True) + + # expire outstanding sessions before parse_authn_request_response checks + # the dict. + self.expire_sessions() + + try: + saml2_auth = self._saml_client.parse_authn_request_response( + resp_bytes, + saml2.BINDING_HTTP_POST, + outstanding=self._outstanding_requests_dict, + ) + except Exception as e: + logger.warning("Exception parsing SAML2 response: %s", e) + raise SynapseError(400, "Unable to parse SAML2 response: %s" % (e,)) + + if saml2_auth.not_signed: + logger.warning("SAML2 response was not signed") + raise SynapseError(400, "SAML2 response was not signed") + + if "uid" not in saml2_auth.ava: + logger.warning("SAML2 response lacks a 'uid' attestation") + raise SynapseError(400, "uid not in SAML2 response") + + self._outstanding_requests_dict.pop(saml2_auth.in_response_to, None) + + username = saml2_auth.ava["uid"][0] + displayName = saml2_auth.ava.get("displayName", [None])[0] + + return self._sso_auth_handler.on_successful_auth( + username, request, relay_state, user_display_name=displayName + ) + + def expire_sessions(self): + expire_before = self._clock.time_msec() - self._saml2_session_lifetime + to_expire = set() + for reqid, data in self._outstanding_requests_dict.items(): + if data.creation_time < expire_before: + to_expire.add(reqid) + for reqid in to_expire: + logger.debug("Expiring session id %s", reqid) + del self._outstanding_requests_dict[reqid] + + +@attr.s +class Saml2SessionData: + """Data we track about SAML2 sessions""" + + # time the session was created, in milliseconds + creation_time = attr.ib() diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py index e88d2ad7bd..f961178235 100644 --- a/synapse/rest/client/v1/login.py +++ b/synapse/rest/client/v1/login.py @@ -86,6 +86,7 @@ class LoginRestServlet(RestServlet): self.jwt_enabled = hs.config.jwt_enabled self.jwt_secret = hs.config.jwt_secret self.jwt_algorithm = hs.config.jwt_algorithm + self.saml2_enabled = hs.config.saml2_enabled self.cas_enabled = hs.config.cas_enabled self.auth_handler = self.hs.get_auth_handler() self.registration_handler = hs.get_registration_handler() @@ -97,6 +98,9 @@ class LoginRestServlet(RestServlet): flows = [] if self.jwt_enabled: flows.append({"type": LoginRestServlet.JWT_TYPE}) + if self.saml2_enabled: + flows.append({"type": LoginRestServlet.SSO_TYPE}) + flows.append({"type": LoginRestServlet.TOKEN_TYPE}) if self.cas_enabled: flows.append({"type": LoginRestServlet.SSO_TYPE}) @@ -351,27 +355,49 @@ class LoginRestServlet(RestServlet): defer.returnValue(result) -class CasRedirectServlet(RestServlet): +class BaseSSORedirectServlet(RestServlet): + """Common base class for /login/sso/redirect impls""" + PATTERNS = client_patterns("/login/(cas|sso)/redirect", v1=True) + def on_GET(self, request): + args = request.args + if b"redirectUrl" not in args: + return 400, "Redirect URL not specified for SSO auth" + client_redirect_url = args[b"redirectUrl"][0] + sso_url = self.get_sso_url(client_redirect_url) + request.redirect(sso_url) + finish_request(request) + + def get_sso_url(self, client_redirect_url): + """Get the URL to redirect to, to perform SSO auth + + Args: + client_redirect_url (bytes): the URL that we should redirect the + client to when everything is done + + Returns: + bytes: URL to redirect to + """ + # to be implemented by subclasses + raise NotImplementedError() + + +class CasRedirectServlet(BaseSSORedirectServlet): def __init__(self, hs): super(CasRedirectServlet, self).__init__() self.cas_server_url = hs.config.cas_server_url.encode("ascii") self.cas_service_url = hs.config.cas_service_url.encode("ascii") - def on_GET(self, request): - args = request.args - if b"redirectUrl" not in args: - return (400, "Redirect URL not specified for CAS auth") + def get_sso_url(self, client_redirect_url): client_redirect_url_param = urllib.parse.urlencode( - {b"redirectUrl": args[b"redirectUrl"][0]} + {b"redirectUrl": client_redirect_url} ).encode("ascii") hs_redirect_url = self.cas_service_url + b"/_matrix/client/r0/login/cas/ticket" service_param = urllib.parse.urlencode( {b"service": b"%s?%s" % (hs_redirect_url, client_redirect_url_param)} ).encode("ascii") - request.redirect(b"%s/login?%s" % (self.cas_server_url, service_param)) - finish_request(request) + return b"%s/login?%s" % (self.cas_server_url, service_param) class CasTicketServlet(RestServlet): @@ -454,6 +480,16 @@ class CasTicketServlet(RestServlet): return user, attributes +class SAMLRedirectServlet(BaseSSORedirectServlet): + PATTERNS = client_patterns("/login/sso/redirect", v1=True) + + def __init__(self, hs): + self._saml_handler = hs.get_saml_handler() + + def get_sso_url(self, client_redirect_url): + return self._saml_handler.handle_redirect_request(client_redirect_url) + + class SSOAuthHandler(object): """ Utility class for Resources and Servlets which handle the response from a SSO @@ -529,3 +565,5 @@ def register_servlets(hs, http_server): if hs.config.cas_enabled: CasRedirectServlet(hs).register(http_server) CasTicketServlet(hs).register(http_server) + elif hs.config.saml2_enabled: + SAMLRedirectServlet(hs).register(http_server) diff --git a/synapse/rest/saml2/response_resource.py b/synapse/rest/saml2/response_resource.py index 939c87306c..69ecc5e4b4 100644 --- a/synapse/rest/saml2/response_resource.py +++ b/synapse/rest/saml2/response_resource.py @@ -13,17 +13,8 @@ # 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. -import logging -import saml2 -from saml2.client import Saml2Client - -from synapse.api.errors import CodeMessageException from synapse.http.server import DirectServeResource, wrap_html_request_handler -from synapse.http.servlet import parse_string -from synapse.rest.client.v1.login import SSOAuthHandler - -logger = logging.getLogger(__name__) class SAML2ResponseResource(DirectServeResource): @@ -33,32 +24,8 @@ class SAML2ResponseResource(DirectServeResource): def __init__(self, hs): super().__init__() - - self._saml_client = Saml2Client(hs.config.saml2_sp_config) - self._sso_auth_handler = SSOAuthHandler(hs) + self._saml_handler = hs.get_saml_handler() @wrap_html_request_handler async def _async_render_POST(self, request): - resp_bytes = parse_string(request, "SAMLResponse", required=True) - relay_state = parse_string(request, "RelayState", required=True) - - try: - saml2_auth = self._saml_client.parse_authn_request_response( - resp_bytes, saml2.BINDING_HTTP_POST - ) - except Exception as e: - logger.warning("Exception parsing SAML2 response", exc_info=1) - raise CodeMessageException(400, "Unable to parse SAML2 response: %s" % (e,)) - - if saml2_auth.not_signed: - raise CodeMessageException(400, "SAML2 response was not signed") - - if "uid" not in saml2_auth.ava: - raise CodeMessageException(400, "uid not in SAML2 response") - - username = saml2_auth.ava["uid"][0] - - displayName = saml2_auth.ava.get("displayName", [None])[0] - return self._sso_auth_handler.on_successful_auth( - username, request, relay_state, user_display_name=displayName - ) + return await self._saml_handler.handle_saml_response(request) diff --git a/synapse/server.py b/synapse/server.py index a9592c396c..9e28dba2b1 100644 --- a/synapse/server.py +++ b/synapse/server.py @@ -194,6 +194,7 @@ class HomeServer(object): "sendmail", "registration_handler", "account_validity_handler", + "saml_handler", "event_client_serializer", ] @@ -524,6 +525,11 @@ class HomeServer(object): def build_account_validity_handler(self): return AccountValidityHandler(self) + def build_saml_handler(self): + from synapse.handlers.saml_handler import SamlHandler + + return SamlHandler(self) + def build_event_client_serializer(self): return EventClientSerializer(self)