Add a module type for account validity (#9884)

This adds an API for third-party plugin modules to implement account validity, so they can provide this feature instead of Synapse. The module implementing the current behaviour for this feature can be found at https://github.com/matrix-org/synapse-email-account-validity.

To allow for a smooth transition between the current feature and the new module, hooks have been added to the existing account validity endpoints to allow their behaviours to be overridden by a module.

synapse/rest/admin/users.py

@@ -560,16 +560,24 @@ class AccountValidityRenewServlet(RestServlet):
     async def on_POST(self, request: SynapseRequest) -> Tuple[int, JsonDict]:
         await assert_requester_is_admin(self.auth, request)
 
-        body = parse_json_object_from_request(request)
+        if self.account_activity_handler.on_legacy_admin_request_callback:
+            expiration_ts = await (
+                self.account_activity_handler.on_legacy_admin_request_callback(request)
+            )
+        else:
+            body = parse_json_object_from_request(request)
 
-        if "user_id" not in body:
-            raise SynapseError(400, "Missing property 'user_id' in the request body")
+            if "user_id" not in body:
+                raise SynapseError(
+                    400,
+                    "Missing property 'user_id' in the request body",
+                )
 
-        expiration_ts = await self.account_activity_handler.renew_account_for_user(
-            body["user_id"],
-            body.get("expiration_ts"),
-            not body.get("enable_renewal_emails", True),
-        )
+            expiration_ts = await self.account_activity_handler.renew_account_for_user(
+                body["user_id"],
+                body.get("expiration_ts"),
+                not body.get("enable_renewal_emails", True),
+            )
 
         res = {"expiration_ts": expiration_ts}
         return 200, res

synapse/rest/client/v2_alpha/account_validity.py

@@ -14,7 +14,7 @@
 
 import logging
 
-from synapse.api.errors import AuthError, SynapseError
+from synapse.api.errors import SynapseError
 from synapse.http.server import respond_with_html
 from synapse.http.servlet import RestServlet
 
@@ -92,11 +92,6 @@ class AccountValiditySendMailServlet(RestServlet):
         )
 
     async def on_POST(self, request):
-        if not self.account_validity_renew_by_email_enabled:
-            raise AuthError(
-                403, "Account renewal via email is disabled on this server."
-            )
-
         requester = await self.auth.get_user_by_req(request, allow_expired=True)
         user_id = requester.user.to_string()
         await self.account_activity_handler.send_renewal_email_to_user(user_id)