MSC4108 implementation (#17056)

Co-authored-by: Hugh Nimmo-Smith <hughns@element.io>
Co-authored-by: Hugh Nimmo-Smith <hughns@users.noreply.github.com>
Co-authored-by: Andrew Morgan <1342360+anoadragon453@users.noreply.github.com>

4 files changed, 85 insertions, 2 deletions

diff --git a/synapse/rest/client/rendezvous.py b/synapse/rest/client/rendezvous.py
index ed06a29987..143f057651 100644
--- a/synapse/rest/client/rendezvous.py
+++ b/synapse/rest/client/rendezvous.py
@@ -97,9 +97,25 @@ class MSC4108DelegationRendezvousServlet(RestServlet):
         )
 
 
+class MSC4108RendezvousServlet(RestServlet):
+    PATTERNS = client_patterns(
+        "/org.matrix.msc4108/rendezvous$", releases=[], v1=False, unstable=True
+    )
+
+    def __init__(self, hs: "HomeServer") -> None:
+        super().__init__()
+        self._handler = hs.get_rendezvous_handler()
+
+    def on_POST(self, request: SynapseRequest) -> None:
+        self._handler.handle_post(request)
+
+
 def register_servlets(hs: "HomeServer", http_server: HttpServer) -> None:
     if hs.config.experimental.msc3886_endpoint is not None:
         MSC3886RendezvousServlet(hs).register(http_server)
 
+    if hs.config.experimental.msc4108_enabled:
+        MSC4108RendezvousServlet(hs).register(http_server)
+
     if hs.config.experimental.msc4108_delegation_endpoint is not None:
         MSC4108DelegationRendezvousServlet(hs).register(http_server)
diff --git a/synapse/rest/client/versions.py b/synapse/rest/client/versions.py
index 638d4c45ae..fa453a3b02 100644
--- a/synapse/rest/client/versions.py
+++ b/synapse/rest/client/versions.py
@@ -141,8 +141,13 @@ class VersionsRestServlet(RestServlet):
                     # Allows clients to handle push for encrypted events.
                     "org.matrix.msc4028": self.config.experimental.msc4028_push_encrypted_events,
                     # MSC4108: Mechanism to allow OIDC sign in and E2EE set up via QR code
-                    "org.matrix.msc4108": self.config.experimental.msc4108_delegation_endpoint
-                    is not None,
+                    "org.matrix.msc4108": (
+                        self.config.experimental.msc4108_enabled
+                        or (
+                            self.config.experimental.msc4108_delegation_endpoint
+                            is not None
+                        )
+                    ),
                 },
             },
         )
diff --git a/synapse/rest/synapse/client/__init__.py b/synapse/rest/synapse/client/__init__.py
index 31544867d4..ba6576d4db 100644
--- a/synapse/rest/synapse/client/__init__.py
+++ b/synapse/rest/synapse/client/__init__.py
@@ -26,6 +26,7 @@ from twisted.web.resource import Resource
 from synapse.rest.synapse.client.new_user_consent import NewUserConsentResource
 from synapse.rest.synapse.client.pick_idp import PickIdpResource
 from synapse.rest.synapse.client.pick_username import pick_username_resource
+from synapse.rest.synapse.client.rendezvous import MSC4108RendezvousSessionResource
 from synapse.rest.synapse.client.sso_register import SsoRegisterResource
 from synapse.rest.synapse.client.unsubscribe import UnsubscribeResource
 
@@ -76,6 +77,9 @@ def build_synapse_client_resource_tree(hs: "HomeServer") -> Mapping[str, Resourc
         # To be removed in Synapse v1.32.0.
         resources["/_matrix/saml2"] = res
 
+    if hs.config.experimental.msc4108_enabled:
+        resources["/_synapse/client/rendezvous"] = MSC4108RendezvousSessionResource(hs)
+
     return resources
 
 
diff --git a/synapse/rest/synapse/client/rendezvous.py b/synapse/rest/synapse/client/rendezvous.py
new file mode 100644
index 0000000000..5216d30d1f
--- /dev/null
+++ b/synapse/rest/synapse/client/rendezvous.py
@@ -0,0 +1,58 @@
+#
+# This file is licensed under the Affero General Public License (AGPL) version 3.
+#
+# Copyright (C) 2024 New Vector, Ltd
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# See the GNU Affero General Public License for more details:
+# <https://www.gnu.org/licenses/agpl-3.0.html>.
+#
+#
+
+import logging
+from typing import TYPE_CHECKING, List
+
+from synapse.api.errors import UnrecognizedRequestError
+from synapse.http.server import DirectServeJsonResource
+from synapse.http.site import SynapseRequest
+
+if TYPE_CHECKING:
+    from synapse.server import HomeServer
+
+logger = logging.getLogger(__name__)
+
+
+class MSC4108RendezvousSessionResource(DirectServeJsonResource):
+    isLeaf = True
+
+    def __init__(self, hs: "HomeServer") -> None:
+        super().__init__()
+        self._handler = hs.get_rendezvous_handler()
+
+    async def _async_render_GET(self, request: SynapseRequest) -> None:
+        postpath: List[bytes] = request.postpath  # type: ignore
+        if len(postpath) != 1:
+            raise UnrecognizedRequestError()
+        session_id = postpath[0].decode("ascii")
+
+        self._handler.handle_get(request, session_id)
+
+    def _async_render_PUT(self, request: SynapseRequest) -> None:
+        postpath: List[bytes] = request.postpath  # type: ignore
+        if len(postpath) != 1:
+            raise UnrecognizedRequestError()
+        session_id = postpath[0].decode("ascii")
+
+        self._handler.handle_put(request, session_id)
+
+    def _async_render_DELETE(self, request: SynapseRequest) -> None:
+        postpath: List[bytes] = request.postpath  # type: ignore
+        if len(postpath) != 1:
+            raise UnrecognizedRequestError()
+        session_id = postpath[0].decode("ascii")
+
+        self._handler.handle_delete(request, session_id)