diff --git a/changelog.d/9362.misc b/changelog.d/9362.misc
new file mode 100644
index 0000000000..c75cfeb2a4
--- /dev/null
+++ b/changelog.d/9362.misc
@@ -0,0 +1 @@
+Clean up the code to load the metadata for OpenID Connect identity providers.
diff --git a/synapse/handlers/oidc_handler.py b/synapse/handlers/oidc_handler.py
index 3adc75fa4a..5f3e8a77f5 100644
--- a/synapse/handlers/oidc_handler.py
+++ b/synapse/handlers/oidc_handler.py
@@ -41,6 +41,7 @@ from synapse.http.site import SynapseRequest
from synapse.logging.context import make_deferred_yieldable
from synapse.types import JsonDict, UserID, map_username_to_mxid_localpart
from synapse.util import json_decoder
+from synapse.util.caches.cached_call import RetryOnExceptionCachedCall
if TYPE_CHECKING:
from synapse.server import HomeServer
@@ -245,6 +246,7 @@ class OidcProvider:
self._token_generator = token_generator
+ self._config = provider
self._callback_url = hs.config.oidc_callback_url # type: str
self._scopes = provider.scopes
@@ -253,14 +255,16 @@ class OidcProvider:
provider.client_id, provider.client_secret, provider.client_auth_method,
) # type: ClientAuth
self._client_auth_method = provider.client_auth_method
- self._provider_metadata = OpenIDProviderMetadata(
- issuer=provider.issuer,
- authorization_endpoint=provider.authorization_endpoint,
- token_endpoint=provider.token_endpoint,
- userinfo_endpoint=provider.userinfo_endpoint,
- jwks_uri=provider.jwks_uri,
- ) # type: OpenIDProviderMetadata
- self._provider_needs_discovery = provider.discover
+
+ # cache of metadata for the identity provider (endpoint uris, mostly). This is
+ # loaded on-demand from the discovery endpoint (if discovery is enabled), with
+ # possible overrides from the config. Access via `load_metadata`.
+ self._provider_metadata = RetryOnExceptionCachedCall(self._load_metadata)
+
+ # cache of JWKs used by the identity provider to sign tokens. Loaded on demand
+ # from the IdP's jwks_uri, if required.
+ self._jwks = RetryOnExceptionCachedCall(self._load_jwks)
+
self._user_mapping_provider = provider.user_mapping_provider_class(
provider.user_mapping_provider_config
)
@@ -286,7 +290,7 @@ class OidcProvider:
self._sso_handler.register_identity_provider(self)
- def _validate_metadata(self):
+ def _validate_metadata(self, m: OpenIDProviderMetadata) -> None:
"""Verifies the provider metadata.
This checks the validity of the currently loaded provider. Not
@@ -305,7 +309,6 @@ class OidcProvider:
if self._skip_verification is True:
return
- m = self._provider_metadata
m.validate_issuer()
m.validate_authorization_endpoint()
m.validate_token_endpoint()
@@ -340,11 +343,7 @@ class OidcProvider:
)
else:
# If we're not using userinfo, we need a valid jwks to validate the ID token
- if m.get("jwks") is None:
- if m.get("jwks_uri") is not None:
- m.validate_jwks_uri()
- else:
- raise ValueError('"jwks_uri" must be set')
+ m.validate_jwks_uri()
@property
def _uses_userinfo(self) -> bool:
@@ -361,11 +360,15 @@ class OidcProvider:
or self._user_profile_method == "userinfo_endpoint"
)
- async def load_metadata(self) -> OpenIDProviderMetadata:
- """Load and validate the provider metadata.
+ async def load_metadata(self, force: bool = False) -> OpenIDProviderMetadata:
+ """Return the provider metadata.
+
+ If this is the first call, the metadata is built from the config and from the
+ metadata discovery endpoint (if enabled), and then validated. If the metadata
+ is successfully validated, it is then cached for future use.
- The values metadatas are discovered if ``oidc_config.discovery`` is
- ``True`` and then cached.
+ Args:
+ force: If true, any cached metadata is discarded to force a reload.
Raises:
ValueError: if something in the provider is not valid
@@ -373,18 +376,32 @@ class OidcProvider:
Returns:
The provider's metadata.
"""
- # If we are using the OpenID Discovery documents, it needs to be loaded once
- # FIXME: should there be a lock here?
- if self._provider_needs_discovery:
- url = get_well_known_url(self._provider_metadata["issuer"], external=True)
+ if force:
+ # reset the cached call to ensure we get a new result
+ self._provider_metadata = RetryOnExceptionCachedCall(self._load_metadata)
+
+ return await self._provider_metadata.get()
+
+ async def _load_metadata(self) -> OpenIDProviderMetadata:
+ # init the metadata from our config
+ metadata = OpenIDProviderMetadata(
+ issuer=self._config.issuer,
+ authorization_endpoint=self._config.authorization_endpoint,
+ token_endpoint=self._config.token_endpoint,
+ userinfo_endpoint=self._config.userinfo_endpoint,
+ jwks_uri=self._config.jwks_uri,
+ )
+
+ # load any data from the discovery endpoint, if enabled
+ if self._config.discover:
+ url = get_well_known_url(self._config.issuer, external=True)
metadata_response = await self._http_client.get_json(url)
# TODO: maybe update the other way around to let user override some values?
- self._provider_metadata.update(metadata_response)
- self._provider_needs_discovery = False
+ metadata.update(metadata_response)
- self._validate_metadata()
+ self._validate_metadata(metadata)
- return self._provider_metadata
+ return metadata
async def load_jwks(self, force: bool = False) -> JWKS:
"""Load the JSON Web Key Set used to sign ID tokens.
@@ -414,27 +431,27 @@ class OidcProvider:
]
}
"""
+ if force:
+ # reset the cached call to ensure we get a new result
+ self._jwks = RetryOnExceptionCachedCall(self._load_jwks)
+ return await self._jwks.get()
+
+ async def _load_jwks(self) -> JWKS:
if self._uses_userinfo:
# We're not using jwt signing, return an empty jwk set
return {"keys": []}
- # First check if the JWKS are loaded in the provider metadata.
- # It can happen either if the provider gives its JWKS in the discovery
- # document directly or if it was already loaded once.
metadata = await self.load_metadata()
- jwk_set = metadata.get("jwks")
- if jwk_set is not None and not force:
- return jwk_set
- # Loading the JWKS using the `jwks_uri` metadata
+ # Load the JWKS using the `jwks_uri` metadata.
uri = metadata.get("jwks_uri")
if not uri:
+ # this should be unreachable: load_metadata validates that
+ # there is a jwks_uri in the metadata if _uses_userinfo is unset
raise RuntimeError('Missing "jwks_uri" in metadata')
jwk_set = await self._http_client.get_json(uri)
- # Caching the JWKS in the provider's metadata
- self._provider_metadata["jwks"] = jwk_set
return jwk_set
async def _exchange_code(self, code: str) -> Token:
diff --git a/synapse/util/caches/cached_call.py b/synapse/util/caches/cached_call.py
new file mode 100644
index 0000000000..3ee0f2317a
--- /dev/null
+++ b/synapse/util/caches/cached_call.py
@@ -0,0 +1,129 @@
+# -*- coding: utf-8 -*-
+# Copyright 2021 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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 typing import Awaitable, Callable, Generic, Optional, TypeVar, Union
+
+from twisted.internet.defer import Deferred
+from twisted.python.failure import Failure
+
+from synapse.logging.context import make_deferred_yieldable, run_in_background
+
+TV = TypeVar("TV")
+
+
+class CachedCall(Generic[TV]):
+ """A wrapper for asynchronous calls whose results should be shared
+
+ This is useful for wrapping asynchronous functions, where there might be multiple
+ callers, but we only want to call the underlying function once (and have the result
+ returned to all callers).
+
+ Similar results can be achieved via a lock of some form, but that typically requires
+ more boilerplate (and ends up being less efficient).
+
+ Correctly handles Synapse logcontexts (logs and resource usage for the underlying
+ function are logged against the logcontext which is active when get() is first
+ called).
+
+ Example usage:
+
+ _cached_val = CachedCall(_load_prop)
+
+ async def handle_request() -> X:
+ # We can call this multiple times, but it will result in a single call to
+ # _load_prop().
+ return await _cached_val.get()
+
+ async def _load_prop() -> X:
+ await difficult_operation()
+
+
+ The implementation is deliberately single-shot (ie, once the call is initiated,
+ there is no way to ask for it to be run). This keeps the implementation and
+ semantics simple. If you want to make a new call, simply replace the whole
+ CachedCall object.
+ """
+
+ __slots__ = ["_callable", "_deferred", "_result"]
+
+ def __init__(self, f: Callable[[], Awaitable[TV]]):
+ """
+ Args:
+ f: The underlying function. Only one call to this function will be alive
+ at once (per instance of CachedCall)
+ """
+ self._callable = f # type: Optional[Callable[[], Awaitable[TV]]]
+ self._deferred = None # type: Optional[Deferred]
+ self._result = None # type: Union[None, Failure, TV]
+
+ async def get(self) -> TV:
+ """Kick off the call if necessary, and return the result"""
+
+ # Fire off the callable now if this is our first time
+ if not self._deferred:
+ self._deferred = run_in_background(self._callable)
+
+ # we will never need the callable again, so make sure it can be GCed
+ self._callable = None
+
+ # once the deferred completes, store the result. We cannot simply leave the
+ # result in the deferred, since if it's a Failure, GCing the deferred
+ # would then log a critical error about unhandled Failures.
+ def got_result(r):
+ self._result = r
+
+ self._deferred.addBoth(got_result)
+
+ # TODO: consider cancellation semantics. Currently, if the call to get()
+ # is cancelled, the underlying call will continue (and any future calls
+ # will get the result/exception), which I think is *probably* ok, modulo
+ # the fact the underlying call may be logged to a cancelled logcontext,
+ # and any eventual exception may not be reported.
+
+ # we can now await the deferred, and once it completes, return the result.
+ await make_deferred_yieldable(self._deferred)
+
+ # I *think* this is the easiest way to correctly raise a Failure without having
+ # to gut-wrench into the implementation of Deferred.
+ d = Deferred()
+ d.callback(self._result)
+ return await d
+
+
+class RetryOnExceptionCachedCall(Generic[TV]):
+ """A wrapper around CachedCall which will retry the call if an exception is thrown
+
+ This is used in much the same way as CachedCall, but adds some extra functionality
+ so that if the underlying function throws an exception, then the next call to get()
+ will initiate another call to the underlying function. (Any calls to get() which
+ are already pending will raise the exception.)
+ """
+
+ slots = ["_cachedcall"]
+
+ def __init__(self, f: Callable[[], Awaitable[TV]]):
+ async def _wrapper() -> TV:
+ try:
+ return await f()
+ except Exception:
+ # the call raised an exception: replace the underlying CachedCall to
+ # trigger another call next time get() is called
+ self._cachedcall = CachedCall(_wrapper)
+ raise
+
+ self._cachedcall = CachedCall(_wrapper)
+
+ async def get(self) -> TV:
+ return await self._cachedcall.get()
diff --git a/tests/handlers/test_oidc.py b/tests/handlers/test_oidc.py
index ad20400b1d..27bb50e3b5 100644
--- a/tests/handlers/test_oidc.py
+++ b/tests/handlers/test_oidc.py
@@ -24,7 +24,7 @@ from synapse.handlers.sso import MappingException
from synapse.server import HomeServer
from synapse.types import UserID
-from tests.test_utils import FakeResponse, simple_async_mock
+from tests.test_utils import FakeResponse, get_awaitable_result, simple_async_mock
from tests.unittest import HomeserverTestCase, override_config
try:
@@ -131,7 +131,6 @@ class OidcHandlerTestCase(HomeserverTestCase):
return config
def make_homeserver(self, reactor, clock):
-
self.http_client = Mock(spec=["get_json"])
self.http_client.get_json.side_effect = get_json
self.http_client.user_agent = "Synapse Test"
@@ -151,7 +150,15 @@ class OidcHandlerTestCase(HomeserverTestCase):
return hs
def metadata_edit(self, values):
- return patch.dict(self.provider._provider_metadata, values)
+ """Modify the result that will be returned by the well-known query"""
+
+ async def patched_get_json(uri):
+ res = await get_json(uri)
+ if uri == WELL_KNOWN:
+ res.update(values)
+ return res
+
+ return patch.object(self.http_client, "get_json", patched_get_json)
def assertRenderedError(self, error, error_description=None):
self.render_error.assert_called_once()
@@ -212,7 +219,14 @@ class OidcHandlerTestCase(HomeserverTestCase):
self.http_client.get_json.assert_called_once_with(JWKS_URI)
# Throw if the JWKS uri is missing
- with self.metadata_edit({"jwks_uri": None}):
+ original = self.provider.load_metadata
+
+ async def patched_load_metadata():
+ m = (await original()).copy()
+ m.update({"jwks_uri": None})
+ return m
+
+ with patch.object(self.provider, "load_metadata", patched_load_metadata):
self.get_failure(self.provider.load_jwks(force=True), RuntimeError)
# Return empty key set if JWKS are not used
@@ -222,55 +236,60 @@ class OidcHandlerTestCase(HomeserverTestCase):
self.http_client.get_json.assert_not_called()
self.assertEqual(jwks, {"keys": []})
- @override_config({"oidc_config": COMMON_CONFIG})
def test_validate_config(self):
"""Provider metadatas are extensively validated."""
h = self.provider
+ def force_load_metadata():
+ async def force_load():
+ return await h.load_metadata(force=True)
+
+ return get_awaitable_result(force_load())
+
# Default test config does not throw
- h._validate_metadata()
+ force_load_metadata()
with self.metadata_edit({"issuer": None}):
- self.assertRaisesRegex(ValueError, "issuer", h._validate_metadata)
+ self.assertRaisesRegex(ValueError, "issuer", force_load_metadata)
with self.metadata_edit({"issuer": "http://insecure/"}):
- self.assertRaisesRegex(ValueError, "issuer", h._validate_metadata)
+ self.assertRaisesRegex(ValueError, "issuer", force_load_metadata)
with self.metadata_edit({"issuer": "https://invalid/?because=query"}):
- self.assertRaisesRegex(ValueError, "issuer", h._validate_metadata)
+ self.assertRaisesRegex(ValueError, "issuer", force_load_metadata)
with self.metadata_edit({"authorization_endpoint": None}):
self.assertRaisesRegex(
- ValueError, "authorization_endpoint", h._validate_metadata
+ ValueError, "authorization_endpoint", force_load_metadata
)
with self.metadata_edit({"authorization_endpoint": "http://insecure/auth"}):
self.assertRaisesRegex(
- ValueError, "authorization_endpoint", h._validate_metadata
+ ValueError, "authorization_endpoint", force_load_metadata
)
with self.metadata_edit({"token_endpoint": None}):
- self.assertRaisesRegex(ValueError, "token_endpoint", h._validate_metadata)
+ self.assertRaisesRegex(ValueError, "token_endpoint", force_load_metadata)
with self.metadata_edit({"token_endpoint": "http://insecure/token"}):
- self.assertRaisesRegex(ValueError, "token_endpoint", h._validate_metadata)
+ self.assertRaisesRegex(ValueError, "token_endpoint", force_load_metadata)
with self.metadata_edit({"jwks_uri": None}):
- self.assertRaisesRegex(ValueError, "jwks_uri", h._validate_metadata)
+ self.assertRaisesRegex(ValueError, "jwks_uri", force_load_metadata)
with self.metadata_edit({"jwks_uri": "http://insecure/jwks.json"}):
- self.assertRaisesRegex(ValueError, "jwks_uri", h._validate_metadata)
+ self.assertRaisesRegex(ValueError, "jwks_uri", force_load_metadata)
with self.metadata_edit({"response_types_supported": ["id_token"]}):
self.assertRaisesRegex(
- ValueError, "response_types_supported", h._validate_metadata
+ ValueError, "response_types_supported", force_load_metadata
)
with self.metadata_edit(
{"token_endpoint_auth_methods_supported": ["client_secret_basic"]}
):
# should not throw, as client_secret_basic is the default auth method
- h._validate_metadata()
+ force_load_metadata()
with self.metadata_edit(
{"token_endpoint_auth_methods_supported": ["client_secret_post"]}
@@ -278,7 +297,7 @@ class OidcHandlerTestCase(HomeserverTestCase):
self.assertRaisesRegex(
ValueError,
"token_endpoint_auth_methods_supported",
- h._validate_metadata,
+ force_load_metadata,
)
# Tests for configs that require the userinfo endpoint
@@ -287,24 +306,24 @@ class OidcHandlerTestCase(HomeserverTestCase):
h._user_profile_method = "userinfo_endpoint"
self.assertTrue(h._uses_userinfo)
- # Revert the profile method and do not request the "openid" scope.
+ # Revert the profile method and do not request the "openid" scope: this should
+ # mean that we check for a userinfo endpoint
h._user_profile_method = "auto"
h._scopes = []
self.assertTrue(h._uses_userinfo)
- self.assertRaisesRegex(ValueError, "userinfo_endpoint", h._validate_metadata)
+ with self.metadata_edit({"userinfo_endpoint": None}):
+ self.assertRaisesRegex(ValueError, "userinfo_endpoint", force_load_metadata)
- with self.metadata_edit(
- {"userinfo_endpoint": USERINFO_ENDPOINT, "jwks_uri": None}
- ):
- # Shouldn't raise with a valid userinfo, even without
- h._validate_metadata()
+ with self.metadata_edit({"jwks_uri": None}):
+ # Shouldn't raise with a valid userinfo, even without jwks
+ force_load_metadata()
@override_config({"oidc_config": {"skip_verification": True}})
def test_skip_verification(self):
"""Provider metadata validation can be disabled by config."""
with self.metadata_edit({"issuer": "http://insecure"}):
# This should not throw
- self.provider._validate_metadata()
+ get_awaitable_result(self.provider.load_metadata())
def test_redirect_request(self):
"""The redirect request has the right arguments & generates a valid session cookie."""
diff --git a/tests/util/caches/test_cached_call.py b/tests/util/caches/test_cached_call.py
new file mode 100644
index 0000000000..f349b5ced0
--- /dev/null
+++ b/tests/util/caches/test_cached_call.py
@@ -0,0 +1,161 @@
+# -*- coding: utf-8 -*-
+# Copyright 2021 The Matrix.org Foundation C.I.C.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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 unittest.mock import Mock
+
+from twisted.internet import defer
+from twisted.internet.defer import Deferred
+
+from synapse.util.caches.cached_call import CachedCall, RetryOnExceptionCachedCall
+
+from tests.test_utils import get_awaitable_result
+from tests.unittest import TestCase
+
+
+class CachedCallTestCase(TestCase):
+ def test_get(self):
+ """
+ Happy-path test case: makes a couple of calls and makes sure they behave
+ correctly
+ """
+ d = Deferred()
+
+ async def f():
+ return await d
+
+ slow_call = Mock(side_effect=f)
+
+ cached_call = CachedCall(slow_call)
+
+ # the mock should not yet have been called
+ slow_call.assert_not_called()
+
+ # now fire off a couple of calls
+ completed_results = []
+
+ async def r():
+ res = await cached_call.get()
+ completed_results.append(res)
+
+ r1 = defer.ensureDeferred(r())
+ r2 = defer.ensureDeferred(r())
+
+ # neither result should be complete yet
+ self.assertNoResult(r1)
+ self.assertNoResult(r2)
+
+ # and the mock should have been called *once*, with no params
+ slow_call.assert_called_once_with()
+
+ # allow the deferred to complete, which should complete both the pending results
+ d.callback(123)
+ self.assertEqual(completed_results, [123, 123])
+ self.successResultOf(r1)
+ self.successResultOf(r2)
+
+ # another call to the getter should complete immediately
+ slow_call.reset_mock()
+ r3 = get_awaitable_result(cached_call.get())
+ self.assertEqual(r3, 123)
+ slow_call.assert_not_called()
+
+ def test_fast_call(self):
+ """
+ Test the behaviour when the underlying function completes immediately
+ """
+
+ async def f():
+ return 12
+
+ fast_call = Mock(side_effect=f)
+ cached_call = CachedCall(fast_call)
+
+ # the mock should not yet have been called
+ fast_call.assert_not_called()
+
+ # run the call a couple of times, which should complete immediately
+ self.assertEqual(get_awaitable_result(cached_call.get()), 12)
+ self.assertEqual(get_awaitable_result(cached_call.get()), 12)
+
+ # the mock should have been called once
+ fast_call.assert_called_once_with()
+
+
+class RetryOnExceptionCachedCallTestCase(TestCase):
+ def test_get(self):
+ # set up the RetryOnExceptionCachedCall around a function which will fail
+ # (after a while)
+ d = Deferred()
+
+ async def f1():
+ await d
+ raise ValueError("moo")
+
+ slow_call = Mock(side_effect=f1)
+ cached_call = RetryOnExceptionCachedCall(slow_call)
+
+ # the mock should not yet have been called
+ slow_call.assert_not_called()
+
+ # now fire off a couple of calls
+ completed_results = []
+
+ async def r():
+ try:
+ await cached_call.get()
+ except Exception as e1:
+ completed_results.append(e1)
+
+ r1 = defer.ensureDeferred(r())
+ r2 = defer.ensureDeferred(r())
+
+ # neither result should be complete yet
+ self.assertNoResult(r1)
+ self.assertNoResult(r2)
+
+ # and the mock should have been called *once*, with no params
+ slow_call.assert_called_once_with()
+
+ # complete the deferred, which should make the pending calls fail
+ d.callback(0)
+ self.assertEqual(len(completed_results), 2)
+ for e in completed_results:
+ self.assertIsInstance(e, ValueError)
+ self.assertEqual(e.args, ("moo",))
+
+ # reset the mock to return a successful result, and make another pair of calls
+ # to the getter
+ d = Deferred()
+
+ async def f2():
+ return await d
+
+ slow_call.reset_mock()
+ slow_call.side_effect = f2
+ r3 = defer.ensureDeferred(cached_call.get())
+ r4 = defer.ensureDeferred(cached_call.get())
+
+ self.assertNoResult(r3)
+ self.assertNoResult(r4)
+ slow_call.assert_called_once_with()
+
+ # let that call complete, and check the results
+ d.callback(123)
+ self.assertEqual(self.successResultOf(r3), 123)
+ self.assertEqual(self.successResultOf(r4), 123)
+
+ # and now more calls to the getter should complete immediately
+ slow_call.reset_mock()
+ self.assertEqual(get_awaitable_result(cached_call.get()), 123)
+ slow_call.assert_not_called()
|
