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| author | Brendan Abolivier <babolivier@matrix.org> | 2020-03-10 13:49:11 +0000 |
|---|---|---|
| committer | Brendan Abolivier <babolivier@matrix.org> | 2020-03-10 13:59:22 +0000 |
| commit | 6b0efe73e21a5d346111df4dd367bc39a03108bb (patch) | |
| tree | 0e20756775f5c628bc33d3b5b2a5b51a425cc70e | |
| parent | Merge pull request #7055 from matrix-org/babolivier/get_time_of_last_push_act... (diff) | |
| download | synapse-6b0efe73e21a5d346111df4dd367bc39a03108bb.tar.xz | |
SAML2: render a comprehensible error page if something goes wrong
If an error happened while processing a SAML AuthN response, or a client ends up doing a `GET` request to `/authn_response`, then render a customisable error page rather than a confusing error.
| -rw-r--r-- | synapse/config/saml2_config.py | 26 | ||||
| -rw-r--r-- | synapse/handlers/saml_handler.py | 20 | ||||
| -rw-r--r-- | synapse/rest/saml2/response_resource.py | 18 |
3 files changed, 62 insertions, 2 deletions
diff --git a/synapse/config/saml2_config.py b/synapse/config/saml2_config.py index 423c158b11..db035bdb5d 100644 --- a/synapse/config/saml2_config.py +++ b/synapse/config/saml2_config.py @@ -27,6 +27,18 @@ DEFAULT_USER_MAPPING_PROVIDER = ( "synapse.handlers.saml_handler.DefaultSamlMappingProvider" ) +SAML2_ERROR_DEFAULT_HTML = """ +<html> + <body> + <p>Oops! Something went wrong</p> + <p> + Try logging in again from the application and if the problem persists + please contact the administrator. + </p> + </body> +</html> +""" + def _dict_merge(merge_dict, into_dict): """Do a deep merge of two dicts @@ -160,6 +172,13 @@ class SAML2Config(Config): saml2_config.get("saml_session_lifetime", "5m") ) + if "error_html_path" in config: + self.saml2_error_html_content = self.read_file( + config["error_html_path"], "saml2_config.error_html_path", + ) + else: + self.saml2_error_html_content = SAML2_ERROR_DEFAULT_HTML + def _default_saml_config_dict( self, required_attributes: set, optional_attributes: set ): @@ -325,6 +344,13 @@ class SAML2Config(Config): # The default is 'uid'. # #grandfathered_mxid_source_attribute: upn + + # Path to a file containing HTML content to serve in case an error happens + # when the user gets redirected from the SAML IdP back to Synapse. + # If no file is provided, this defaults to some minimalistic HTML telling the + # user that something went wrong and they should try authenticating again. + # + #error_html_path: /path/to/static/content/saml_error.html """ % { "config_dir_path": config_dir_path } diff --git a/synapse/handlers/saml_handler.py b/synapse/handlers/saml_handler.py index 9406753393..72c109981b 100644 --- a/synapse/handlers/saml_handler.py +++ b/synapse/handlers/saml_handler.py @@ -23,6 +23,7 @@ from saml2.client import Saml2Client from synapse.api.errors import SynapseError from synapse.config import ConfigError +from synapse.http.server import finish_request from synapse.http.servlet import parse_string from synapse.module_api import ModuleApi from synapse.types import ( @@ -73,6 +74,8 @@ class SamlHandler: # a lock on the mappings self._mapping_lock = Linearizer(name="saml_mapping", clock=self._clock) + self._error_html_content = hs.config.saml2_error_html_content + def handle_redirect_request(self, client_redirect_url): """Handle an incoming request to /login/sso/redirect @@ -114,7 +117,22 @@ class SamlHandler: # the dict. self.expire_sessions() - user_id = await self._map_saml_response_to_user(resp_bytes, relay_state) + try: + user_id = await self._map_saml_response_to_user(resp_bytes, relay_state) + except Exception as e: + # If decoding the response or mapping it to a user failed, then log the + # error and tell the user that something went wrong. + logger.error(e) + + request.setResponseCode(400) + request.setHeader(b"Content-Type", b"text/html; charset=utf-8") + request.setHeader( + b"Content-Length", b"%d" % (len(self._error_html_content),) + ) + request.write(self._error_html_content.encode("utf8")) + finish_request(request) + return + self._auth_handler.complete_sso_login(user_id, request, relay_state) async def _map_saml_response_to_user(self, resp_bytes, client_redirect_url): diff --git a/synapse/rest/saml2/response_resource.py b/synapse/rest/saml2/response_resource.py index 69ecc5e4b4..a545c13db7 100644 --- a/synapse/rest/saml2/response_resource.py +++ b/synapse/rest/saml2/response_resource.py @@ -14,7 +14,11 @@ # See the License for the specific language governing permissions and # limitations under the License. -from synapse.http.server import DirectServeResource, wrap_html_request_handler +from synapse.http.server import ( + DirectServeResource, + finish_request, + wrap_html_request_handler, +) class SAML2ResponseResource(DirectServeResource): @@ -24,8 +28,20 @@ class SAML2ResponseResource(DirectServeResource): def __init__(self, hs): super().__init__() + self._error_html_content = hs.config.saml2_error_html_content self._saml_handler = hs.get_saml_handler() + async def _async_render_GET(self, request): + # We're not expecting any GET request on that resource if everything goes right, + # but some IdPs sometimes end up responding with a 302 redirect on this endpoint. + # In this case, just tell the user that something went wrong and they should + # try to authenticate again. + request.setResponseCode(400) + request.setHeader(b"Content-Type", b"text/html; charset=utf-8") + request.setHeader(b"Content-Length", b"%d" % (len(self._error_html_content),)) + request.write(self._error_html_content.encode("utf8")) + finish_request(request) + @wrap_html_request_handler async def _async_render_POST(self, request): return await self._saml_handler.handle_saml_response(request) |