From 6e613a10d072c32e72d6b97b2d178bb840769f3e Mon Sep 17 00:00:00 2001 From: Callum Brown Date: Wed, 18 Aug 2021 13:13:35 +0100 Subject: [PATCH] Display an error page during failure of fallback UIA. (#10561) --- changelog.d/10561.bugfix | 1 + docs/upgrade.md | 8 +++++ synapse/handlers/auth.py | 27 +++++++++------- synapse/handlers/ui_auth/checkers.py | 10 ++++-- synapse/res/templates/recaptcha.html | 3 ++ synapse/res/templates/terms.html | 3 ++ synapse/rest/client/auth.py | 39 +++++++++++++++--------- synapse/static/client/register/style.css | 6 +++- 8 files changed, 67 insertions(+), 30 deletions(-) create mode 100644 changelog.d/10561.bugfix diff --git a/changelog.d/10561.bugfix b/changelog.d/10561.bugfix new file mode 100644 index 0000000000..2e4f53508c --- /dev/null +++ b/changelog.d/10561.bugfix @@ -0,0 +1 @@ +Display an error on User-Interactive Authentication fallback pages when authentication fails. Contributed by Callum Brown. diff --git a/docs/upgrade.md b/docs/upgrade.md index 3ac2387e2a..adbd16fda5 100644 --- a/docs/upgrade.md +++ b/docs/upgrade.md @@ -125,6 +125,14 @@ environment variable. See [using a forward proxy with Synapse documentation](setup/forward_proxy.md) for details. +## User-interactive authentication fallback templates can now display errors + +This may affect you if you make use of custom HTML templates for the +[reCAPTCHA](../synapse/res/templates/recaptcha.html) or +[terms](../synapse/res/templates/terms.html) fallback pages. + +The template is now provided an `error` variable if the authentication +process failed. See the default templates linked above for an example. # Upgrading to v1.39.0 diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py index 161b3c933c..98d3d2d97f 100644 --- a/synapse/handlers/auth.py +++ b/synapse/handlers/auth.py @@ -627,23 +627,28 @@ class AuthHandler(BaseHandler): async def add_oob_auth( self, stagetype: str, authdict: Dict[str, Any], clientip: str - ) -> bool: + ) -> None: """ Adds the result of out-of-band authentication into an existing auth session. Currently used for adding the result of fallback auth. + + Raises: + LoginError if the stagetype is unknown or the session is missing. + LoginError is raised by check_auth if authentication fails. """ if stagetype not in self.checkers: - raise LoginError(400, "", Codes.MISSING_PARAM) - if "session" not in authdict: - raise LoginError(400, "", Codes.MISSING_PARAM) - - result = await self.checkers[stagetype].check_auth(authdict, clientip) - if result: - await self.store.mark_ui_auth_stage_complete( - authdict["session"], stagetype, result + raise LoginError( + 400, f"Unknown UIA stage type: {stagetype}", Codes.INVALID_PARAM ) - return True - return False + if "session" not in authdict: + raise LoginError(400, "Missing session ID", Codes.MISSING_PARAM) + + # If authentication fails a LoginError is raised. Otherwise, store + # the successful result. + result = await self.checkers[stagetype].check_auth(authdict, clientip) + await self.store.mark_ui_auth_stage_complete( + authdict["session"], stagetype, result + ) def get_session_id(self, clientdict: Dict[str, Any]) -> Optional[str]: """ diff --git a/synapse/handlers/ui_auth/checkers.py b/synapse/handlers/ui_auth/checkers.py index 5414ce77d8..270541cc76 100644 --- a/synapse/handlers/ui_auth/checkers.py +++ b/synapse/handlers/ui_auth/checkers.py @@ -49,7 +49,7 @@ class UserInteractiveAuthChecker: clientip: The IP address of the client. Raises: - SynapseError if authentication failed + LoginError if authentication failed. Returns: The result of authentication (to pass back to the client?) @@ -131,7 +131,9 @@ class RecaptchaAuthChecker(UserInteractiveAuthChecker): ) if resp_body["success"]: return True - raise LoginError(401, "", errcode=Codes.UNAUTHORIZED) + raise LoginError( + 401, "Captcha authentication failed", errcode=Codes.UNAUTHORIZED + ) class _BaseThreepidAuthChecker: @@ -191,7 +193,9 @@ class _BaseThreepidAuthChecker: raise AssertionError("Unrecognized threepid medium: %s" % (medium,)) if not threepid: - raise LoginError(401, "", errcode=Codes.UNAUTHORIZED) + raise LoginError( + 401, "Unable to get validated threepid", errcode=Codes.UNAUTHORIZED + ) if threepid["medium"] != medium: raise LoginError( diff --git a/synapse/res/templates/recaptcha.html b/synapse/res/templates/recaptcha.html index 63944dc608..b3db06ef97 100644 --- a/synapse/res/templates/recaptcha.html +++ b/synapse/res/templates/recaptcha.html @@ -16,6 +16,9 @@ function captchaDone() {
+ {% if error is defined %} +

Error: {{ error }}

+ {% endif %}

Hello! We need to prevent computer programs and other automated things from creating accounts on this server. diff --git a/synapse/res/templates/terms.html b/synapse/res/templates/terms.html index dfef9897ee..369ff446d2 100644 --- a/synapse/res/templates/terms.html +++ b/synapse/res/templates/terms.html @@ -8,6 +8,9 @@

+ {% if error is defined %} +

Error: {{ error }}

+ {% endif %}

Please click the button below if you agree to the privacy policy of this homeserver. diff --git a/synapse/rest/client/auth.py b/synapse/rest/client/auth.py index 6ea1b50a62..73284e48ec 100644 --- a/synapse/rest/client/auth.py +++ b/synapse/rest/client/auth.py @@ -16,7 +16,7 @@ import logging from typing import TYPE_CHECKING from synapse.api.constants import LoginType -from synapse.api.errors import SynapseError +from synapse.api.errors import LoginError, SynapseError from synapse.api.urls import CLIENT_API_PREFIX from synapse.http.server import respond_with_html from synapse.http.servlet import RestServlet, parse_string @@ -95,29 +95,32 @@ class AuthRestServlet(RestServlet): authdict = {"response": response, "session": session} - success = await self.auth_handler.add_oob_auth( - LoginType.RECAPTCHA, authdict, request.getClientIP() - ) - - if success: - html = self.success_template.render() - else: + try: + await self.auth_handler.add_oob_auth( + LoginType.RECAPTCHA, authdict, request.getClientIP() + ) + except LoginError as e: + # Authentication failed, let user try again html = self.recaptcha_template.render( session=session, myurl="%s/r0/auth/%s/fallback/web" % (CLIENT_API_PREFIX, LoginType.RECAPTCHA), sitekey=self.hs.config.recaptcha_public_key, + error=e.msg, ) + else: + # No LoginError was raised, so authentication was successful + html = self.success_template.render() + elif stagetype == LoginType.TERMS: authdict = {"session": session} - success = await self.auth_handler.add_oob_auth( - LoginType.TERMS, authdict, request.getClientIP() - ) - - if success: - html = self.success_template.render() - else: + try: + await self.auth_handler.add_oob_auth( + LoginType.TERMS, authdict, request.getClientIP() + ) + except LoginError as e: + # Authentication failed, let user try again html = self.terms_template.render( session=session, terms_url="%s_matrix/consent?v=%s" @@ -127,10 +130,16 @@ class AuthRestServlet(RestServlet): ), myurl="%s/r0/auth/%s/fallback/web" % (CLIENT_API_PREFIX, LoginType.TERMS), + error=e.msg, ) + else: + # No LoginError was raised, so authentication was successful + html = self.success_template.render() + 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/static/client/register/style.css b/synapse/static/client/register/style.css index 5a7b6eebf2..8a39b5d0f5 100644 --- a/synapse/static/client/register/style.css +++ b/synapse/static/client/register/style.css @@ -57,4 +57,8 @@ textarea, input { background-color: #f8f8f8; border: 1px #ccc solid; -} \ No newline at end of file +} + +.error { + color: red; +}