From b9930d24a05e47c36845d8607b12a45eea889be0 Mon Sep 17 00:00:00 2001 From: Patrick Cloke Date: Wed, 1 Apr 2020 08:48:00 -0400 Subject: [PATCH] Support SAML in the user interactive authentication workflow. (#7102) --- CHANGES.md | 8 ++ changelog.d/7102.feature | 1 + synapse/api/constants.py | 1 + synapse/handlers/auth.py | 116 +++++++++++++++++++- synapse/handlers/saml_handler.py | 51 +++++++-- synapse/res/templates/sso_auth_confirm.html | 14 +++ synapse/rest/client/v2_alpha/account.py | 19 +++- synapse/rest/client/v2_alpha/auth.py | 42 +++---- synapse/rest/client/v2_alpha/devices.py | 12 +- synapse/rest/client/v2_alpha/keys.py | 6 +- synapse/rest/client/v2_alpha/register.py | 1 + 11 files changed, 227 insertions(+), 44 deletions(-) create mode 100644 changelog.d/7102.feature create mode 100644 synapse/res/templates/sso_auth_confirm.html diff --git a/CHANGES.md b/CHANGES.md index f794c585b..b997af163 100644 --- a/CHANGES.md +++ b/CHANGES.md @@ -1,3 +1,11 @@ +Next version +============ + +* A new template (`sso_auth_confirm.html`) was added to Synapse. If your Synapse + is configured to use SSO and a custom `sso_redirect_confirm_template_dir` + configuration then this template will need to be duplicated into that + directory. + Synapse 1.12.0 (2020-03-23) =========================== diff --git a/changelog.d/7102.feature b/changelog.d/7102.feature new file mode 100644 index 000000000..01057aa39 --- /dev/null +++ b/changelog.d/7102.feature @@ -0,0 +1 @@ +Support SSO in the user interactive authentication workflow. diff --git a/synapse/api/constants.py b/synapse/api/constants.py index cc8577552..fda2c2e5b 100644 --- a/synapse/api/constants.py +++ b/synapse/api/constants.py @@ -61,6 +61,7 @@ class LoginType(object): MSISDN = "m.login.msisdn" RECAPTCHA = "m.login.recaptcha" TERMS = "m.login.terms" + SSO = "org.matrix.login.sso" DUMMY = "m.login.dummy" # Only for C/S API v1 diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py index 2ce1425df..7c09d15a7 100644 --- a/synapse/handlers/auth.py +++ b/synapse/handlers/auth.py @@ -53,6 +53,31 @@ from ._base import BaseHandler logger = logging.getLogger(__name__) +SUCCESS_TEMPLATE = """ + + +Success! + + + + + +
+

Thank you

+

You may now close this window and return to the application

+
+ + +""" + + class AuthHandler(BaseHandler): SESSION_EXPIRE_MS = 48 * 60 * 60 * 1000 @@ -91,6 +116,7 @@ class AuthHandler(BaseHandler): self.hs = hs # FIXME better possibility to access registrationHandler later? self.macaroon_gen = hs.get_macaroon_generator() self._password_enabled = hs.config.password_enabled + self._saml2_enabled = hs.config.saml2_enabled # we keep this as a list despite the O(N^2) implication so that we can # keep PASSWORD first and avoid confusing clients which pick the first @@ -106,6 +132,13 @@ class AuthHandler(BaseHandler): if t not in login_types: login_types.append(t) self._supported_login_types = login_types + # Login types and UI Auth types have a heavy overlap, but are not + # necessarily identical. Login types have SSO (and other login types) + # added in the rest layer, see synapse.rest.client.v1.login.LoginRestServerlet.on_GET. + ui_auth_types = login_types.copy() + if self._saml2_enabled: + ui_auth_types.append(LoginType.SSO) + self._supported_ui_auth_types = ui_auth_types # Ratelimiter for failed auth during UIA. Uses same ratelimit config # as per `rc_login.failed_attempts`. @@ -113,10 +146,21 @@ class AuthHandler(BaseHandler): self._clock = self.hs.get_clock() - # Load the SSO redirect confirmation page HTML template + # Load the SSO HTML templates. + + # The following template is shown to the user during a client login via SSO, + # after the SSO completes and before redirecting them back to their client. + # It notifies the user they are about to give access to their matrix account + # to the client. self._sso_redirect_confirm_template = load_jinja2_templates( hs.config.sso_redirect_confirm_template_dir, ["sso_redirect_confirm.html"], )[0] + # The following template is shown during user interactive authentication + # in the fallback auth scenario. It notifies the user that they are + # authenticating for an operation to occur on their account. + self._sso_auth_confirm_template = load_jinja2_templates( + hs.config.sso_redirect_confirm_template_dir, ["sso_auth_confirm.html"], + )[0] self._server_name = hs.config.server_name @@ -130,6 +174,7 @@ class AuthHandler(BaseHandler): request: SynapseRequest, request_body: Dict[str, Any], clientip: str, + description: str, ): """ Checks that the user is who they claim to be, via a UI auth. @@ -147,6 +192,9 @@ class AuthHandler(BaseHandler): clientip: The IP address of the client. + description: A human readable string to be displayed to the user that + describes the operation happening on their account. + Returns: defer.Deferred[dict]: the parameters for this request (which may have been given only in a previous call). @@ -175,11 +223,11 @@ class AuthHandler(BaseHandler): ) # build a list of supported flows - flows = [[login_type] for login_type in self._supported_login_types] + flows = [[login_type] for login_type in self._supported_ui_auth_types] try: result, params, _ = yield self.check_auth( - flows, request, request_body, clientip + flows, request, request_body, clientip, description ) except LoginError: # Update the ratelimite to say we failed (`can_do_action` doesn't raise). @@ -193,7 +241,7 @@ class AuthHandler(BaseHandler): raise # find the completed login type - for login_type in self._supported_login_types: + for login_type in self._supported_ui_auth_types: if login_type not in result: continue @@ -224,6 +272,7 @@ class AuthHandler(BaseHandler): request: SynapseRequest, clientdict: Dict[str, Any], clientip: str, + description: str, ): """ Takes a dictionary sent by the client in the login / registration @@ -250,6 +299,9 @@ class AuthHandler(BaseHandler): clientip: The IP address of the client. + description: A human readable string to be displayed to the user that + describes the operation happening on their account. + Returns: defer.Deferred[dict, dict, str]: a deferred tuple of (creds, params, session_id). @@ -299,12 +351,18 @@ class AuthHandler(BaseHandler): comparator = (request.uri, request.method, clientdict) if "ui_auth" not in session: session["ui_auth"] = comparator + self._save_session(session) elif session["ui_auth"] != comparator: raise SynapseError( 403, "Requested operation has changed during the UI authentication session.", ) + # Add a human readable description to the session. + if "description" not in session: + session["description"] = description + self._save_session(session) + if not authdict: raise InteractiveAuthIncompleteError( self._auth_dict_for_flows(flows, session) @@ -991,6 +1049,56 @@ class AuthHandler(BaseHandler): else: return defer.succeed(False) + def start_sso_ui_auth(self, redirect_url: str, session_id: str) -> str: + """ + Get the HTML for the SSO redirect confirmation page. + + Args: + redirect_url: The URL to redirect to the SSO provider. + session_id: The user interactive authentication session ID. + + Returns: + The HTML to render. + """ + session = self._get_session_info(session_id) + # Get the human readable operation of what is occurring, falling back to + # a generic message if it isn't available for some reason. + description = session.get("description", "modify your account") + return self._sso_auth_confirm_template.render( + description=description, redirect_url=redirect_url, + ) + + def complete_sso_ui_auth( + self, registered_user_id: str, session_id: str, request: SynapseRequest, + ): + """Having figured out a mxid for this user, complete the HTTP request + + Args: + registered_user_id: The registered user ID to complete SSO login for. + request: The request to complete. + client_redirect_url: The URL to which to redirect the user at the end of the + process. + """ + # Mark the stage of the authentication as successful. + sess = self._get_session_info(session_id) + if "creds" not in sess: + sess["creds"] = {} + creds = sess["creds"] + + # Save the user who authenticated with SSO, this will be used to ensure + # that the account be modified is also the person who logged in. + creds[LoginType.SSO] = registered_user_id + self._save_session(sess) + + # Render the HTML and return. + html_bytes = SUCCESS_TEMPLATE.encode("utf8") + request.setResponseCode(200) + request.setHeader(b"Content-Type", b"text/html; charset=utf-8") + request.setHeader(b"Content-Length", b"%d" % (len(html_bytes),)) + + request.write(html_bytes) + finish_request(request) + def complete_sso_login( self, registered_user_id: str, diff --git a/synapse/handlers/saml_handler.py b/synapse/handlers/saml_handler.py index dc04b53f4..4741c82f6 100644 --- a/synapse/handlers/saml_handler.py +++ b/synapse/handlers/saml_handler.py @@ -14,7 +14,7 @@ # limitations under the License. import logging import re -from typing import Tuple +from typing import Optional, Tuple import attr import saml2 @@ -44,11 +44,15 @@ class Saml2SessionData: # time the session was created, in milliseconds creation_time = attr.ib() + # The user interactive authentication session ID associated with this SAML + # session (or None if this SAML session is for an initial login). + ui_auth_session_id = attr.ib(type=Optional[str], default=None) class SamlHandler: def __init__(self, hs): self._saml_client = Saml2Client(hs.config.saml2_sp_config) + self._auth = hs.get_auth() self._auth_handler = hs.get_auth_handler() self._registration_handler = hs.get_registration_handler() @@ -77,12 +81,14 @@ class SamlHandler: self._error_html_content = hs.config.saml2_error_html_content - def handle_redirect_request(self, client_redirect_url): + def handle_redirect_request(self, client_redirect_url, ui_auth_session_id=None): """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 + ui_auth_session_id (Optional[str]): The session ID of the ongoing UI Auth (or + None if this is a login). Returns: bytes: URL to redirect to @@ -92,7 +98,9 @@ class SamlHandler: ) now = self._clock.time_msec() - self._outstanding_requests_dict[reqid] = Saml2SessionData(creation_time=now) + self._outstanding_requests_dict[reqid] = Saml2SessionData( + creation_time=now, ui_auth_session_id=ui_auth_session_id, + ) for key, value in info["headers"]: if key == "Location": @@ -119,7 +127,9 @@ class SamlHandler: self.expire_sessions() try: - user_id = await self._map_saml_response_to_user(resp_bytes, relay_state) + user_id, current_session = await self._map_saml_response_to_user( + resp_bytes, relay_state + ) except RedirectException: # Raise the exception as per the wishes of the SAML module response raise @@ -137,9 +147,28 @@ class SamlHandler: finish_request(request) return - self._auth_handler.complete_sso_login(user_id, request, relay_state) + # Complete the interactive auth session or the login. + if current_session and current_session.ui_auth_session_id: + self._auth_handler.complete_sso_ui_auth( + user_id, current_session.ui_auth_session_id, request + ) - async def _map_saml_response_to_user(self, resp_bytes, client_redirect_url): + else: + self._auth_handler.complete_sso_login(user_id, request, relay_state) + + async def _map_saml_response_to_user( + self, resp_bytes: str, client_redirect_url: str + ) -> Tuple[str, Optional[Saml2SessionData]]: + """ + Given a sample response, retrieve the cached session and user for it. + + Args: + resp_bytes: The SAML response. + client_redirect_url: The redirect URL passed in by the client. + + Returns: + Tuple of the user ID and SAML session associated with this response. + """ try: saml2_auth = self._saml_client.parse_authn_request_response( resp_bytes, @@ -167,7 +196,9 @@ class SamlHandler: logger.info("SAML2 mapped attributes: %s", saml2_auth.ava) - self._outstanding_requests_dict.pop(saml2_auth.in_response_to, None) + current_session = self._outstanding_requests_dict.pop( + saml2_auth.in_response_to, None + ) remote_user_id = self._user_mapping_provider.get_remote_user_id( saml2_auth, client_redirect_url @@ -188,7 +219,7 @@ class SamlHandler: ) if registered_user_id is not None: logger.info("Found existing mapping %s", registered_user_id) - return registered_user_id + return registered_user_id, current_session # backwards-compatibility hack: see if there is an existing user with a # suitable mapping from the uid @@ -213,7 +244,7 @@ class SamlHandler: await self._datastore.record_user_external_id( self._auth_provider_id, remote_user_id, registered_user_id ) - return registered_user_id + return registered_user_id, current_session # Map saml response to user attributes using the configured mapping provider for i in range(1000): @@ -260,7 +291,7 @@ class SamlHandler: await self._datastore.record_user_external_id( self._auth_provider_id, remote_user_id, registered_user_id ) - return registered_user_id + return registered_user_id, current_session def expire_sessions(self): expire_before = self._clock.time_msec() - self._saml2_session_lifetime diff --git a/synapse/res/templates/sso_auth_confirm.html b/synapse/res/templates/sso_auth_confirm.html new file mode 100644 index 000000000..0d9de9d46 --- /dev/null +++ b/synapse/res/templates/sso_auth_confirm.html @@ -0,0 +1,14 @@ + + + Authentication + + +
+

+ A client is trying to {{ description | e }}. To confirm this action, + re-authenticate with single sign-on. + If you did not expect this, your account may be compromised! +

+
+ + diff --git a/synapse/rest/client/v2_alpha/account.py b/synapse/rest/client/v2_alpha/account.py index f80b5e40e..31435b1e1 100644 --- a/synapse/rest/client/v2_alpha/account.py +++ b/synapse/rest/client/v2_alpha/account.py @@ -234,7 +234,11 @@ class PasswordRestServlet(RestServlet): if self.auth.has_access_token(request): requester = await self.auth.get_user_by_req(request) params = await self.auth_handler.validate_user_via_ui_auth( - requester, request, body, self.hs.get_ip_from_request(request), + requester, + request, + body, + self.hs.get_ip_from_request(request), + "modify your account password", ) user_id = requester.user.to_string() else: @@ -244,6 +248,7 @@ class PasswordRestServlet(RestServlet): request, body, self.hs.get_ip_from_request(request), + "modify your account password", ) if LoginType.EMAIL_IDENTITY in result: @@ -311,7 +316,11 @@ class DeactivateAccountRestServlet(RestServlet): return 200, {} await self.auth_handler.validate_user_via_ui_auth( - requester, request, body, self.hs.get_ip_from_request(request), + requester, + request, + body, + self.hs.get_ip_from_request(request), + "deactivate your account", ) result = await self._deactivate_account_handler.deactivate_account( requester.user.to_string(), erase, id_server=body.get("id_server") @@ -669,7 +678,11 @@ class ThreepidAddRestServlet(RestServlet): assert_valid_client_secret(client_secret) await self.auth_handler.validate_user_via_ui_auth( - requester, request, body, self.hs.get_ip_from_request(request), + requester, + request, + body, + self.hs.get_ip_from_request(request), + "add a third-party identifier to your account", ) validation_session = await self.identity_handler.validate_threepid_session( diff --git a/synapse/rest/client/v2_alpha/auth.py b/synapse/rest/client/v2_alpha/auth.py index 85cf5a14c..1787562b9 100644 --- a/synapse/rest/client/v2_alpha/auth.py +++ b/synapse/rest/client/v2_alpha/auth.py @@ -18,6 +18,7 @@ import logging from synapse.api.constants import LoginType from synapse.api.errors import SynapseError from synapse.api.urls import CLIENT_API_PREFIX +from synapse.handlers.auth import SUCCESS_TEMPLATE from synapse.http.server import finish_request from synapse.http.servlet import RestServlet, parse_string @@ -89,30 +90,6 @@ TERMS_TEMPLATE = """ """ -SUCCESS_TEMPLATE = """ - - -Success! - - - - - -
-

Thank you

-

You may now close this window and return to the application

-
- - -""" - class AuthRestServlet(RestServlet): """ @@ -130,6 +107,11 @@ class AuthRestServlet(RestServlet): self.auth_handler = hs.get_auth_handler() self.registration_handler = hs.get_registration_handler() + # SSO configuration. + self._saml_enabled = hs.config.saml2_enabled + if self._saml_enabled: + self._saml_handler = hs.get_saml_handler() + def on_GET(self, request, stagetype): session = parse_string(request, "session") if not session: @@ -150,6 +132,15 @@ class AuthRestServlet(RestServlet): "myurl": "%s/r0/auth/%s/fallback/web" % (CLIENT_API_PREFIX, LoginType.TERMS), } + + elif stagetype == LoginType.SSO and self._saml_enabled: + # Display a confirmation page which prompts the user to + # re-authenticate with their SSO provider. + client_redirect_url = "" + sso_redirect_url = self._saml_handler.handle_redirect_request( + client_redirect_url, session + ) + html = self.auth_handler.start_sso_ui_auth(sso_redirect_url, session) else: raise SynapseError(404, "Unknown auth stage type") @@ -210,6 +201,9 @@ class AuthRestServlet(RestServlet): "myurl": "%s/r0/auth/%s/fallback/web" % (CLIENT_API_PREFIX, LoginType.TERMS), } + elif stagetype == LoginType.SSO: + # The SSO fallback workflow should not post here, + raise SynapseError(404, "Fallback SSO auth does not support POST requests.") else: raise SynapseError(404, "Unknown auth stage type") diff --git a/synapse/rest/client/v2_alpha/devices.py b/synapse/rest/client/v2_alpha/devices.py index 119d97905..c0714fcfb 100644 --- a/synapse/rest/client/v2_alpha/devices.py +++ b/synapse/rest/client/v2_alpha/devices.py @@ -81,7 +81,11 @@ class DeleteDevicesRestServlet(RestServlet): assert_params_in_dict(body, ["devices"]) await self.auth_handler.validate_user_via_ui_auth( - requester, request, body, self.hs.get_ip_from_request(request), + requester, + request, + body, + self.hs.get_ip_from_request(request), + "remove device(s) from your account", ) await self.device_handler.delete_devices( @@ -127,7 +131,11 @@ class DeviceRestServlet(RestServlet): raise await self.auth_handler.validate_user_via_ui_auth( - requester, request, body, self.hs.get_ip_from_request(request), + requester, + request, + body, + self.hs.get_ip_from_request(request), + "remove a device from your account", ) await self.device_handler.delete_device(requester.user.to_string(), device_id) diff --git a/synapse/rest/client/v2_alpha/keys.py b/synapse/rest/client/v2_alpha/keys.py index 5eb7ef35a..8f41a3edb 100644 --- a/synapse/rest/client/v2_alpha/keys.py +++ b/synapse/rest/client/v2_alpha/keys.py @@ -263,7 +263,11 @@ class SigningKeyUploadServlet(RestServlet): body = parse_json_object_from_request(request) await self.auth_handler.validate_user_via_ui_auth( - requester, request, body, self.hs.get_ip_from_request(request), + requester, + request, + body, + self.hs.get_ip_from_request(request), + "add a device signing key to your account", ) result = await self.e2e_keys_handler.upload_signing_keys_for_user(user_id, body) diff --git a/synapse/rest/client/v2_alpha/register.py b/synapse/rest/client/v2_alpha/register.py index 66fc8ec17..431ecf4f8 100644 --- a/synapse/rest/client/v2_alpha/register.py +++ b/synapse/rest/client/v2_alpha/register.py @@ -505,6 +505,7 @@ class RegisterRestServlet(RestServlet): request, body, self.hs.get_ip_from_request(request), + "register a new account", ) # Check that we're not trying to register a denied 3pid.