diff options
| -rw-r--r-- | changelog.d/7614.misc | 1 | ||||
| -rw-r--r-- | docs/sample_config.yaml | 8 | ||||
| -rw-r--r-- | synapse/config/saml2_config.py | 18 | ||||
| -rw-r--r-- | synapse/handlers/saml_handler.py | 41 | ||||
| -rw-r--r-- | synapse/http/server.py | 43 | ||||
| -rw-r--r-- | synapse/rest/saml2/response_resource.py | 26 | ||||
| -rw-r--r-- | tox.ini | 1 |
7 files changed, 77 insertions, 61 deletions
diff --git a/changelog.d/7614.misc b/changelog.d/7614.misc new file mode 100644 index 0000000000..f0e24f9f61 --- /dev/null +++ b/changelog.d/7614.misc @@ -0,0 +1 @@ +Clean up exception handling in `SAML2ResponseResource`. diff --git a/docs/sample_config.yaml b/docs/sample_config.yaml index ce2c235994..6784234d5f 100644 --- a/docs/sample_config.yaml +++ b/docs/sample_config.yaml @@ -1512,7 +1512,13 @@ saml2_config: # * HTML page to display to users if something goes wrong during the # authentication process: 'saml_error.html'. # - # This template doesn't currently need any variable to render. + # When rendering, this template is given the following variables: + # * code: an HTML error code corresponding to the error that is being + # returned (typically 400 or 500) + # + # * msg: a textual message describing the error. + # + # The variables will automatically be HTML-escaped. # # You can see the default templates at: # https://github.com/matrix-org/synapse/tree/master/synapse/res/templates diff --git a/synapse/config/saml2_config.py b/synapse/config/saml2_config.py index 726a27d7b2..38ec256984 100644 --- a/synapse/config/saml2_config.py +++ b/synapse/config/saml2_config.py @@ -15,8 +15,8 @@ # limitations under the License. import logging -import os +import jinja2 import pkg_resources from synapse.python_dependencies import DependencyException, check_requirements @@ -167,9 +167,11 @@ class SAML2Config(Config): if not template_dir: template_dir = pkg_resources.resource_filename("synapse", "res/templates",) - self.saml2_error_html_content = self.read_file( - os.path.join(template_dir, "saml_error.html"), "saml2_config.saml_error", - ) + loader = jinja2.FileSystemLoader(template_dir) + # enable auto-escape here, to having to remember to escape manually in the + # template + env = jinja2.Environment(loader=loader, autoescape=True) + self.saml2_error_html_template = env.get_template("saml_error.html") def _default_saml_config_dict( self, required_attributes: set, optional_attributes: set @@ -349,7 +351,13 @@ class SAML2Config(Config): # * HTML page to display to users if something goes wrong during the # authentication process: 'saml_error.html'. # - # This template doesn't currently need any variable to render. + # When rendering, this template is given the following variables: + # * code: an HTML error code corresponding to the error that is being + # returned (typically 400 or 500) + # + # * msg: a textual message describing the error. + # + # The variables will automatically be HTML-escaped. # # You can see the default templates at: # https://github.com/matrix-org/synapse/tree/master/synapse/res/templates diff --git a/synapse/handlers/saml_handler.py b/synapse/handlers/saml_handler.py index de6ba4ab55..abecaa8313 100644 --- a/synapse/handlers/saml_handler.py +++ b/synapse/handlers/saml_handler.py @@ -23,11 +23,9 @@ 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.http.site import SynapseRequest from synapse.module_api import ModuleApi -from synapse.module_api.errors import RedirectException from synapse.types import ( UserID, map_username_to_mxid_localpart, @@ -80,8 +78,6 @@ 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: bytes, ui_auth_session_id: Optional[str] = None ) -> bytes: @@ -129,26 +125,9 @@ class SamlHandler: # the dict. self.expire_sessions() - try: - 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 - 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 + user_id, current_session = await self._map_saml_response_to_user( + resp_bytes, relay_state + ) # Complete the interactive auth session or the login. if current_session and current_session.ui_auth_session_id: @@ -171,6 +150,11 @@ class SamlHandler: Returns: Tuple of the user ID and SAML session associated with this response. + + Raises: + SynapseError if there was a problem with the response. + RedirectException: some mapping providers may raise this if they need + to redirect to an interstitial page. """ try: saml2_auth = self._saml_client.parse_authn_request_response( @@ -179,11 +163,9 @@ class SamlHandler: 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") logger.debug("SAML2 response: %s", saml2_auth.origxml) @@ -264,11 +246,10 @@ class SamlHandler: localpart = attribute_dict.get("mxid_localpart") if not localpart: - logger.error( - "SAML mapping provider plugin did not return a " - "mxid_localpart object" + raise Exception( + "Error parsing SAML2 response: SAML mapping provider plugin " + "did not return a mxid_localpart value" ) - raise SynapseError(500, "Error parsing SAML2 response") displayname = attribute_dict.get("displayname") emails = attribute_dict.get("emails", []) diff --git a/synapse/http/server.py b/synapse/http/server.py index 9cc2e2e154..2487a72171 100644 --- a/synapse/http/server.py +++ b/synapse/http/server.py @@ -21,13 +21,15 @@ import logging import types import urllib from io import BytesIO +from typing import Awaitable, Callable, TypeVar, Union +import jinja2 from canonicaljson import encode_canonical_json, encode_pretty_printed_json, json from twisted.internet import defer from twisted.python import failure from twisted.web import resource -from twisted.web.server import NOT_DONE_YET +from twisted.web.server import NOT_DONE_YET, Request from twisted.web.static import NoRangeStaticProducer from twisted.web.util import redirectTo @@ -40,6 +42,7 @@ from synapse.api.errors import ( SynapseError, UnrecognizedRequestError, ) +from synapse.http.site import SynapseRequest from synapse.logging.context import preserve_fn from synapse.logging.opentracing import trace_servlet from synapse.util.caches import intern_dict @@ -130,7 +133,12 @@ def wrap_json_request_handler(h): return wrap_async_request_handler(wrapped_request_handler) -def wrap_html_request_handler(h): +TV = TypeVar("TV") + + +def wrap_html_request_handler( + h: Callable[[TV, SynapseRequest], Awaitable] +) -> Callable[[TV, SynapseRequest], Awaitable[None]]: """Wraps a request handler method with exception handling. Also does the wrapping with request.processing as per wrap_async_request_handler. @@ -141,20 +149,26 @@ def wrap_html_request_handler(h): async def wrapped_request_handler(self, request): try: - return await h(self, request) + await h(self, request) except Exception: f = failure.Failure() - return _return_html_error(f, request) + return_html_error(f, request, HTML_ERROR_TEMPLATE) return wrap_async_request_handler(wrapped_request_handler) -def _return_html_error(f, request): - """Sends an HTML error page corresponding to the given failure +def return_html_error( + f: failure.Failure, request: Request, error_template: Union[str, jinja2.Template], +) -> None: + """Sends an HTML error page corresponding to the given failure. + + Handles RedirectException and other CodeMessageExceptions (such as SynapseError) Args: - f (twisted.python.failure.Failure): - request (twisted.web.server.Request): + f: the error to report + request: the failing request + error_template: the HTML template. Can be either a string (with `{code}`, + `{msg}` placeholders), or a jinja2 template """ if f.check(CodeMessageException): cme = f.value @@ -174,7 +188,7 @@ def _return_html_error(f, request): exc_info=(f.type, f.value, f.getTracebackObject()), ) else: - code = http.client.INTERNAL_SERVER_ERROR + code = http.HTTPStatus.INTERNAL_SERVER_ERROR msg = "Internal server error" logger.error( @@ -183,11 +197,16 @@ def _return_html_error(f, request): exc_info=(f.type, f.value, f.getTracebackObject()), ) - body = HTML_ERROR_TEMPLATE.format(code=code, msg=html.escape(msg)).encode("utf-8") + if isinstance(error_template, str): + body = error_template.format(code=code, msg=html.escape(msg)) + else: + body = error_template.render(code=code, msg=msg) + + body_bytes = body.encode("utf-8") request.setResponseCode(code) request.setHeader(b"Content-Type", b"text/html; charset=utf-8") - request.setHeader(b"Content-Length", b"%i" % (len(body),)) - request.write(body) + request.setHeader(b"Content-Length", b"%i" % (len(body_bytes),)) + request.write(body_bytes) finish_request(request) diff --git a/synapse/rest/saml2/response_resource.py b/synapse/rest/saml2/response_resource.py index a545c13db7..75e58043b4 100644 --- a/synapse/rest/saml2/response_resource.py +++ b/synapse/rest/saml2/response_resource.py @@ -13,12 +13,10 @@ # 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 twisted.python import failure -from synapse.http.server import ( - DirectServeResource, - finish_request, - wrap_html_request_handler, -) +from synapse.api.errors import SynapseError +from synapse.http.server import DirectServeResource, return_html_error class SAML2ResponseResource(DirectServeResource): @@ -28,20 +26,22 @@ 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() + self._error_html_template = hs.config.saml2.saml2_error_html_template 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) + f = failure.Failure( + SynapseError(400, "Unexpected GET request on /saml2/authn_response") + ) + return_html_error(f, request, self._error_html_template) - @wrap_html_request_handler async def _async_render_POST(self, request): - return await self._saml_handler.handle_saml_response(request) + try: + await self._saml_handler.handle_saml_response(request) + except Exception: + f = failure.Failure() + return_html_error(f, request, self._error_html_template) diff --git a/tox.ini b/tox.ini index 9fefcb72b5..463a34d137 100644 --- a/tox.ini +++ b/tox.ini @@ -193,6 +193,7 @@ commands = mypy \ synapse/handlers/saml_handler.py \ synapse/handlers/sync.py \ synapse/handlers/ui_auth \ + synapse/http/server.py \ synapse/http/site.py \ synapse/logging/ \ synapse/metrics \ |