MSC3861: load the issuer and account management URLs from OIDC discovery (#17407)

This will help mitigating any discrepancies between the issuer
configured and the one returned by the OIDC provider.

This also removes the need for configuring the `account_management_url`
explicitely, as it will now be loaded from the OIDC discovery, as per
MSC2965.

Because we may now fetch stuff for the .well-known/matrix/client
endpoint, this also transforms the client well-known resource to be
asynchronous.
This commit is contained in:
Quentin Gliech 2024-08-30 16:04:08 +02:00 committed by Erik Johnston
parent 53a3783750
commit 48303fcbcc
9 changed files with 126 additions and 46 deletions

1
changelog.d/17407.misc Normal file
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@ -0,0 +1 @@
MSC3861: load the issuer and account management URLs from OIDC discovery.

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@ -121,7 +121,9 @@ class MSC3861DelegatedAuth(BaseAuth):
self._hostname = hs.hostname
self._admin_token = self._config.admin_token
self._issuer_metadata = RetryOnExceptionCachedCall(self._load_metadata)
self._issuer_metadata = RetryOnExceptionCachedCall[OpenIDProviderMetadata](
self._load_metadata
)
if isinstance(auth_method, PrivateKeyJWTWithKid):
# Use the JWK as the client secret when using the private_key_jwt method
@ -145,6 +147,33 @@ class MSC3861DelegatedAuth(BaseAuth):
# metadata.validate_introspection_endpoint()
return metadata
async def issuer(self) -> str:
"""
Get the configured issuer
This will use the issuer value set in the metadata,
falling back to the one set in the config if not set in the metadata
"""
metadata = await self._issuer_metadata.get()
return metadata.issuer or self._config.issuer
async def account_management_url(self) -> Optional[str]:
"""
Get the configured account management URL
This will discover the account management URL from the issuer if it's not set in the config
"""
if self._config.account_management_url is not None:
return self._config.account_management_url
try:
metadata = await self._issuer_metadata.get()
return metadata.get("account_management_uri", None)
# We don't want to raise here if we can't load the metadata
except Exception:
logger.warning("Failed to load metadata:", exc_info=True)
return None
async def _introspection_endpoint(self) -> str:
"""
Returns the introspection endpoint of the issuer
@ -154,7 +183,7 @@ class MSC3861DelegatedAuth(BaseAuth):
if self._config.introspection_endpoint is not None:
return self._config.introspection_endpoint
metadata = await self._load_metadata()
metadata = await self._issuer_metadata.get()
return metadata.get("introspection_endpoint")
async def _introspect_token(self, token: str) -> IntrospectionToken:

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@ -20,7 +20,7 @@
#
import logging
from typing import TYPE_CHECKING
from typing import TYPE_CHECKING, cast
from twisted.web.server import Request
@ -70,11 +70,17 @@ class AuthRestServlet(RestServlet):
self.hs.config.experimental.msc3861.enabled
and stagetype == "org.matrix.cross_signing_reset"
):
config = self.hs.config.experimental.msc3861
if config.account_management_url is not None:
url = f"{config.account_management_url}?action=org.matrix.cross_signing_reset"
# If MSC3861 is enabled, we can assume self._auth is an instance of MSC3861DelegatedAuth
# We import lazily here because of the authlib requirement
from synapse.api.auth.msc3861_delegated import MSC3861DelegatedAuth
auth = cast(MSC3861DelegatedAuth, self.auth)
url = await auth.account_management_url()
if url is not None:
url = f"{url}?action=org.matrix.cross_signing_reset"
else:
url = config.issuer
url = await auth.issuer()
respond_with_redirect(request, str.encode(url))
if stagetype == LoginType.RECAPTCHA:

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@ -13,7 +13,7 @@
# limitations under the License.
import logging
import typing
from typing import Tuple
from typing import Tuple, cast
from synapse.api.errors import Codes, SynapseError
from synapse.http.server import HttpServer
@ -43,10 +43,16 @@ class AuthIssuerServlet(RestServlet):
def __init__(self, hs: "HomeServer"):
super().__init__()
self._config = hs.config
self._auth = hs.get_auth()
async def on_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
if self._config.experimental.msc3861.enabled:
return 200, {"issuer": self._config.experimental.msc3861.issuer}
# If MSC3861 is enabled, we can assume self._auth is an instance of MSC3861DelegatedAuth
# We import lazily here because of the authlib requirement
from synapse.api.auth.msc3861_delegated import MSC3861DelegatedAuth
auth = cast(MSC3861DelegatedAuth, self._auth)
return 200, {"issuer": await auth.issuer()}
else:
# Wouldn't expect this to be reached: the servelet shouldn't have been
# registered. Still, fail gracefully if we are registered for some reason.

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@ -23,7 +23,7 @@
import logging
import re
from collections import Counter
from typing import TYPE_CHECKING, Any, Dict, Optional, Tuple
from typing import TYPE_CHECKING, Any, Dict, Optional, Tuple, cast
from synapse.api.errors import (
InteractiveAuthIncompleteError,
@ -406,11 +406,17 @@ class SigningKeyUploadServlet(RestServlet):
# explicitly mark the master key as replaceable.
if self.hs.config.experimental.msc3861.enabled:
if not master_key_updatable_without_uia:
config = self.hs.config.experimental.msc3861
if config.account_management_url is not None:
url = f"{config.account_management_url}?action=org.matrix.cross_signing_reset"
# If MSC3861 is enabled, we can assume self.auth is an instance of MSC3861DelegatedAuth
# We import lazily here because of the authlib requirement
from synapse.api.auth.msc3861_delegated import MSC3861DelegatedAuth
auth = cast(MSC3861DelegatedAuth, self.auth)
uri = await auth.account_management_url()
if uri is not None:
url = f"{uri}?action=org.matrix.cross_signing_reset"
else:
url = config.issuer
url = await auth.issuer()
# We use a dummy session ID as this isn't really a UIA flow, but we
# reuse the same API shape for better client compatibility.

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@ -268,7 +268,7 @@ class LoginRestServlet(RestServlet):
approval_notice_medium=ApprovalNoticeMedium.NONE,
)
well_known_data = self._well_known_builder.get_well_known()
well_known_data = await self._well_known_builder.get_well_known()
if well_known_data:
result["well_known"] = well_known_data
return 200, result

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@ -18,12 +18,13 @@
#
#
import logging
from typing import TYPE_CHECKING, Optional
from typing import TYPE_CHECKING, Optional, Tuple, cast
from twisted.web.resource import Resource
from twisted.web.server import Request
from synapse.http.server import set_cors_headers
from synapse.api.errors import NotFoundError
from synapse.http.server import DirectServeJsonResource
from synapse.http.site import SynapseRequest
from synapse.types import JsonDict
from synapse.util import json_encoder
@ -38,8 +39,9 @@ logger = logging.getLogger(__name__)
class WellKnownBuilder:
def __init__(self, hs: "HomeServer"):
self._config = hs.config
self._auth = hs.get_auth()
def get_well_known(self) -> Optional[JsonDict]:
async def get_well_known(self) -> Optional[JsonDict]:
if not self._config.server.serve_client_wellknown:
return None
@ -52,13 +54,20 @@ class WellKnownBuilder:
# We use the MSC3861 values as they are used by multiple MSCs
if self._config.experimental.msc3861.enabled:
# If MSC3861 is enabled, we can assume self._auth is an instance of MSC3861DelegatedAuth
# We import lazily here because of the authlib requirement
from synapse.api.auth.msc3861_delegated import MSC3861DelegatedAuth
auth = cast(MSC3861DelegatedAuth, self._auth)
result["org.matrix.msc2965.authentication"] = {
"issuer": self._config.experimental.msc3861.issuer
"issuer": await auth.issuer(),
}
if self._config.experimental.msc3861.account_management_url is not None:
account_management_url = await auth.account_management_url()
if account_management_url is not None:
result["org.matrix.msc2965.authentication"][
"account"
] = self._config.experimental.msc3861.account_management_url
] = account_management_url
if self._config.server.extra_well_known_client_content:
for (
@ -71,26 +80,22 @@ class WellKnownBuilder:
return result
class ClientWellKnownResource(Resource):
class ClientWellKnownResource(DirectServeJsonResource):
"""A Twisted web resource which renders the .well-known/matrix/client file"""
isLeaf = 1
def __init__(self, hs: "HomeServer"):
Resource.__init__(self)
super().__init__()
self._well_known_builder = WellKnownBuilder(hs)
def render_GET(self, request: SynapseRequest) -> bytes:
set_cors_headers(request)
r = self._well_known_builder.get_well_known()
async def _async_render_GET(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
r = await self._well_known_builder.get_well_known()
if not r:
request.setResponseCode(404)
request.setHeader(b"Content-Type", b"text/plain")
return b".well-known not available"
raise NotFoundError(".well-known not available")
logger.debug("returning: %s", r)
request.setHeader(b"Content-Type", b"application/json")
return json_encoder.encode(r).encode("utf-8")
return 200, r
class ServerWellKnownResource(Resource):

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@ -12,6 +12,7 @@
# See the License for the specific language governing permissions and
# limitations under the License.
from http import HTTPStatus
from unittest.mock import AsyncMock
from synapse.rest.client import auth_issuer
@ -50,10 +51,27 @@ class AuthIssuerTestCase(HomeserverTestCase):
}
)
def test_returns_issuer_when_oidc_enabled(self) -> None:
# Make an unauthenticated request for the discovery info.
# Patch the HTTP client to return the issuer metadata
req_mock = AsyncMock(return_value={"issuer": ISSUER})
self.hs.get_proxied_http_client().get_json = req_mock # type: ignore[method-assign]
channel = self.make_request(
"GET",
"/_matrix/client/unstable/org.matrix.msc2965/auth_issuer",
)
self.assertEqual(channel.code, HTTPStatus.OK)
self.assertEqual(channel.json_body, {"issuer": ISSUER})
req_mock.assert_called_with("https://account.example.com/.well-known/openid-configuration")
req_mock.reset_mock()
# Second call it should use the cached value
channel = self.make_request(
"GET",
"/_matrix/client/unstable/org.matrix.msc2965/auth_issuer",
)
self.assertEqual(channel.code, HTTPStatus.OK)
self.assertEqual(channel.json_body, {"issuer": ISSUER})
req_mock.assert_not_called()

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@ -17,6 +17,8 @@
# [This file includes modifications made by New Vector Limited]
#
#
from unittest.mock import AsyncMock
from twisted.web.resource import Resource
from synapse.rest.well_known import well_known_resource
@ -112,7 +114,6 @@ class WellKnownTests(unittest.HomeserverTestCase):
"msc3861": {
"enabled": True,
"issuer": "https://issuer",
"account_management_url": "https://my-account.issuer",
"client_id": "id",
"client_auth_method": "client_secret_post",
"client_secret": "secret",
@ -122,6 +123,11 @@ class WellKnownTests(unittest.HomeserverTestCase):
}
)
def test_client_well_known_msc3861_oauth_delegation(self) -> None:
# Patch the HTTP client to return the issuer metadata
req_mock = AsyncMock(return_value={"issuer": "https://issuer", "account_management_uri": "https://my-account.issuer"})
self.hs.get_proxied_http_client().get_json = req_mock # type: ignore[method-assign]
for _ in range(2):
channel = self.make_request(
"GET", "/.well-known/matrix/client", shorthand=False
)
@ -137,3 +143,6 @@ class WellKnownTests(unittest.HomeserverTestCase):
},
},
)
# It should have been called exactly once, because it gets cached
req_mock.assert_called_once_with("https://issuer/.well-known/openid-configuration")