From a3cf36f76ed41222241393adf608d0e640bb51b8 Mon Sep 17 00:00:00 2001 From: Patrick Cloke Date: Fri, 15 May 2020 12:26:02 -0400 Subject: [PATCH] Support UI Authentication for OpenID Connect accounts (#7457) --- changelog.d/7457.feature | 1 + synapse/handlers/auth.py | 4 +- synapse/handlers/oidc_handler.py | 76 +++++++++++++++++++++------- synapse/rest/client/v1/login.py | 31 +++++++----- synapse/rest/client/v2_alpha/auth.py | 19 +++++-- tests/handlers/test_oidc.py | 15 ++++-- 6 files changed, 105 insertions(+), 41 deletions(-) create mode 100644 changelog.d/7457.feature diff --git a/changelog.d/7457.feature b/changelog.d/7457.feature new file mode 100644 index 000000000..7ad767bf7 --- /dev/null +++ b/changelog.d/7457.feature @@ -0,0 +1 @@ +Add OpenID Connect login/registration support. Contributed by Quentin Gliech, on behalf of [les Connecteurs](https://connecteu.rs). diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py index 524281d2f..75b39e878 100644 --- a/synapse/handlers/auth.py +++ b/synapse/handlers/auth.py @@ -80,7 +80,9 @@ 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._sso_enabled = hs.config.saml2_enabled or hs.config.cas_enabled + self._sso_enabled = ( + hs.config.cas_enabled or hs.config.saml2_enabled or hs.config.oidc_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 diff --git a/synapse/handlers/oidc_handler.py b/synapse/handlers/oidc_handler.py index 178f26343..4ba8c7fda 100644 --- a/synapse/handlers/oidc_handler.py +++ b/synapse/handlers/oidc_handler.py @@ -311,7 +311,7 @@ class OidcHandler: ``ClientAuth`` to authenticate with the client with its ID and secret. Args: - code: The autorization code we got from the callback. + code: The authorization code we got from the callback. Returns: A dict containing various tokens. @@ -497,11 +497,14 @@ class OidcHandler: return UserInfo(claims) async def handle_redirect_request( - self, request: SynapseRequest, client_redirect_url: bytes - ) -> None: + self, + request: SynapseRequest, + client_redirect_url: bytes, + ui_auth_session_id: Optional[str] = None, + ) -> str: """Handle an incoming request to /login/sso/redirect - It redirects the browser to the authorization endpoint with a few + It returns a redirect to the authorization endpoint with a few parameters: - ``client_id``: the client ID set in ``oidc_config.client_id`` @@ -511,24 +514,32 @@ class OidcHandler: - ``state``: a random string - ``nonce``: a random string - In addition to redirecting the client, we are setting a cookie with + In addition generating a redirect URL, we are setting a cookie with a signed macaroon token containing the state, the nonce and the client_redirect_url params. Those are then checked when the client comes back from the provider. - Args: request: the incoming request from the browser. We'll respond to it with a redirect and a cookie. client_redirect_url: the URL that we should redirect the client to when everything is done + ui_auth_session_id: The session ID of the ongoing UI Auth (or + None if this is a login). + + Returns: + The redirect URL to the authorization endpoint. + """ state = generate_token() nonce = generate_token() cookie = self._generate_oidc_session_token( - state=state, nonce=nonce, client_redirect_url=client_redirect_url.decode(), + state=state, + nonce=nonce, + client_redirect_url=client_redirect_url.decode(), + ui_auth_session_id=ui_auth_session_id, ) request.addCookie( SESSION_COOKIE_NAME, @@ -541,7 +552,7 @@ class OidcHandler: metadata = await self.load_metadata() authorization_endpoint = metadata.get("authorization_endpoint") - uri = prepare_grant_uri( + return prepare_grant_uri( authorization_endpoint, client_id=self._client_auth.client_id, response_type="code", @@ -550,8 +561,6 @@ class OidcHandler: state=state, nonce=nonce, ) - request.redirect(uri) - finish_request(request) async def handle_oidc_callback(self, request: SynapseRequest) -> None: """Handle an incoming request to /_synapse/oidc/callback @@ -625,7 +634,11 @@ class OidcHandler: # Deserialize the session token and verify it. try: - nonce, client_redirect_url = self._verify_oidc_session_token(session, state) + ( + nonce, + client_redirect_url, + ui_auth_session_id, + ) = self._verify_oidc_session_token(session, state) except MacaroonDeserializationException as e: logger.exception("Invalid session") self._render_error(request, "invalid_session", str(e)) @@ -678,15 +691,21 @@ class OidcHandler: return # and finally complete the login - await self._auth_handler.complete_sso_login( - user_id, request, client_redirect_url - ) + if ui_auth_session_id: + await self._auth_handler.complete_sso_ui_auth( + user_id, ui_auth_session_id, request + ) + else: + await self._auth_handler.complete_sso_login( + user_id, request, client_redirect_url + ) def _generate_oidc_session_token( self, state: str, nonce: str, client_redirect_url: str, + ui_auth_session_id: Optional[str], duration_in_ms: int = (60 * 60 * 1000), ) -> str: """Generates a signed token storing data about an OIDC session. @@ -702,6 +721,8 @@ class OidcHandler: nonce: The ``nonce`` parameter passed to the OIDC provider. client_redirect_url: The URL the client gave when it initiated the flow. + ui_auth_session_id: The session ID of the ongoing UI Auth (or + None if this is a login). duration_in_ms: An optional duration for the token in milliseconds. Defaults to an hour. @@ -718,12 +739,19 @@ class OidcHandler: macaroon.add_first_party_caveat( "client_redirect_url = %s" % (client_redirect_url,) ) + if ui_auth_session_id: + macaroon.add_first_party_caveat( + "ui_auth_session_id = %s" % (ui_auth_session_id,) + ) now = self._clock.time_msec() expiry = now + duration_in_ms macaroon.add_first_party_caveat("time < %d" % (expiry,)) + return macaroon.serialize() - def _verify_oidc_session_token(self, session: str, state: str) -> Tuple[str, str]: + def _verify_oidc_session_token( + self, session: str, state: str + ) -> Tuple[str, str, Optional[str]]: """Verifies and extract an OIDC session token. This verifies that a given session token was issued by this homeserver @@ -734,7 +762,7 @@ class OidcHandler: state: The state the OIDC provider gave back Returns: - The nonce and the client_redirect_url for this session + The nonce, client_redirect_url, and ui_auth_session_id for this session """ macaroon = pymacaroons.Macaroon.deserialize(session) @@ -744,17 +772,27 @@ class OidcHandler: v.satisfy_exact("state = %s" % (state,)) v.satisfy_general(lambda c: c.startswith("nonce = ")) v.satisfy_general(lambda c: c.startswith("client_redirect_url = ")) + # Sometimes there's a UI auth session ID, it seems to be OK to attempt + # to always satisfy this. + v.satisfy_general(lambda c: c.startswith("ui_auth_session_id = ")) v.satisfy_general(self._verify_expiry) v.verify(macaroon, self._macaroon_secret_key) - # Extract the `nonce` and `client_redirect_url` from the token + # Extract the `nonce`, `client_redirect_url`, and maybe the + # `ui_auth_session_id` from the token. nonce = self._get_value_from_macaroon(macaroon, "nonce") client_redirect_url = self._get_value_from_macaroon( macaroon, "client_redirect_url" ) + try: + ui_auth_session_id = self._get_value_from_macaroon( + macaroon, "ui_auth_session_id" + ) # type: Optional[str] + except ValueError: + ui_auth_session_id = None - return nonce, client_redirect_url + return nonce, client_redirect_url, ui_auth_session_id def _get_value_from_macaroon(self, macaroon: pymacaroons.Macaroon, key: str) -> str: """Extracts a caveat value from a macaroon token. @@ -773,7 +811,7 @@ class OidcHandler: for caveat in macaroon.caveats: if caveat.caveat_id.startswith(prefix): return caveat.caveat_id[len(prefix) :] - raise Exception("No %s caveat in macaroon" % (key,)) + raise ValueError("No %s caveat in macaroon" % (key,)) def _verify_expiry(self, caveat: str) -> bool: prefix = "time < " diff --git a/synapse/rest/client/v1/login.py b/synapse/rest/client/v1/login.py index de7eca21f..d89b2e553 100644 --- a/synapse/rest/client/v1/login.py +++ b/synapse/rest/client/v1/login.py @@ -401,19 +401,22 @@ class BaseSSORedirectServlet(RestServlet): PATTERNS = client_patterns("/login/(cas|sso)/redirect", v1=True) - def on_GET(self, request: SynapseRequest): + async def on_GET(self, request: SynapseRequest): 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) + sso_url = await self.get_sso_url(request, client_redirect_url) request.redirect(sso_url) finish_request(request) - def get_sso_url(self, client_redirect_url: bytes) -> bytes: + async def get_sso_url( + self, request: SynapseRequest, client_redirect_url: bytes + ) -> bytes: """Get the URL to redirect to, to perform SSO auth Args: + request: The client request to redirect. client_redirect_url: the URL that we should redirect the client to when everything is done @@ -428,7 +431,9 @@ class CasRedirectServlet(BaseSSORedirectServlet): def __init__(self, hs): self._cas_handler = hs.get_cas_handler() - def get_sso_url(self, client_redirect_url: bytes) -> bytes: + async def get_sso_url( + self, request: SynapseRequest, client_redirect_url: bytes + ) -> bytes: return self._cas_handler.get_redirect_url( {"redirectUrl": client_redirect_url} ).encode("ascii") @@ -465,11 +470,13 @@ class SAMLRedirectServlet(BaseSSORedirectServlet): def __init__(self, hs): self._saml_handler = hs.get_saml_handler() - def get_sso_url(self, client_redirect_url: bytes) -> bytes: + async def get_sso_url( + self, request: SynapseRequest, client_redirect_url: bytes + ) -> bytes: return self._saml_handler.handle_redirect_request(client_redirect_url) -class OIDCRedirectServlet(RestServlet): +class OIDCRedirectServlet(BaseSSORedirectServlet): """Implementation for /login/sso/redirect for the OIDC login flow.""" PATTERNS = client_patterns("/login/sso/redirect", v1=True) @@ -477,12 +484,12 @@ class OIDCRedirectServlet(RestServlet): def __init__(self, hs): self._oidc_handler = hs.get_oidc_handler() - async 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] - await self._oidc_handler.handle_redirect_request(request, client_redirect_url) + async def get_sso_url( + self, request: SynapseRequest, client_redirect_url: bytes + ) -> bytes: + return await self._oidc_handler.handle_redirect_request( + request, client_redirect_url + ) def register_servlets(hs, http_server): diff --git a/synapse/rest/client/v2_alpha/auth.py b/synapse/rest/client/v2_alpha/auth.py index 24dd3d3e9..7bca1326d 100644 --- a/synapse/rest/client/v2_alpha/auth.py +++ b/synapse/rest/client/v2_alpha/auth.py @@ -131,14 +131,19 @@ class AuthRestServlet(RestServlet): 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() self._cas_enabled = hs.config.cas_enabled if self._cas_enabled: self._cas_handler = hs.get_cas_handler() self._cas_server_url = hs.config.cas_server_url self._cas_service_url = hs.config.cas_service_url + self._saml_enabled = hs.config.saml2_enabled + if self._saml_enabled: + self._saml_handler = hs.get_saml_handler() + self._oidc_enabled = hs.config.oidc_enabled + if self._oidc_enabled: + self._oidc_handler = hs.get_oidc_handler() + self._cas_server_url = hs.config.cas_server_url + self._cas_service_url = hs.config.cas_service_url async def on_GET(self, request, stagetype): session = parse_string(request, "session") @@ -172,11 +177,17 @@ class AuthRestServlet(RestServlet): ) elif self._saml_enabled: - client_redirect_url = "" + client_redirect_url = b"" sso_redirect_url = self._saml_handler.handle_redirect_request( client_redirect_url, session ) + elif self._oidc_enabled: + client_redirect_url = b"" + sso_redirect_url = await self._oidc_handler.handle_redirect_request( + request, client_redirect_url, session + ) + else: raise SynapseError(400, "Homeserver not configured for SSO.") diff --git a/tests/handlers/test_oidc.py b/tests/handlers/test_oidc.py index 61963aa90..1bb25ab68 100644 --- a/tests/handlers/test_oidc.py +++ b/tests/handlers/test_oidc.py @@ -292,11 +292,10 @@ class OidcHandlerTestCase(HomeserverTestCase): @defer.inlineCallbacks def test_redirect_request(self): """The redirect request has the right arguments & generates a valid session cookie.""" - req = Mock(spec=["addCookie", "redirect", "finish"]) - yield defer.ensureDeferred( + req = Mock(spec=["addCookie"]) + url = yield defer.ensureDeferred( self.handler.handle_redirect_request(req, b"http://client/redirect") ) - url = req.redirect.call_args[0][0] url = urlparse(url) auth_endpoint = urlparse(AUTHORIZATION_ENDPOINT) @@ -382,7 +381,10 @@ class OidcHandlerTestCase(HomeserverTestCase): nonce = "nonce" client_redirect_url = "http://client/redirect" session = self.handler._generate_oidc_session_token( - state=state, nonce=nonce, client_redirect_url=client_redirect_url, + state=state, + nonce=nonce, + client_redirect_url=client_redirect_url, + ui_auth_session_id=None, ) request.getCookie.return_value = session @@ -472,7 +474,10 @@ class OidcHandlerTestCase(HomeserverTestCase): # Mismatching session session = self.handler._generate_oidc_session_token( - state="state", nonce="nonce", client_redirect_url="http://client/redirect", + state="state", + nonce="nonce", + client_redirect_url="http://client/redirect", + ui_auth_session_id=None, ) request.args = {} request.args[b"state"] = [b"mismatching state"]