diff --git a/proposals/4124-server-auth-simple.md b/proposals/4124-server-auth-simple.md index 2cc80a71..5b27061d 100644 --- a/proposals/4124-server-auth-simple.md +++ b/proposals/4124-server-auth-simple.md @@ -126,6 +126,21 @@ if the leaking is part of an intentional attack. They could then change the join rule for the room, but this would provide a disruption to their service that outlives the attack. +### Theorized workaround for leaky servers: leak detection + +It has been suggested that it is possible to detect a leak by +forensically analyzing the DAG in order to find which servers +are accepting a denied server's events by analyzing which +servers have used them as forward extremities. + +The author does not consider this to be an acceptable workaround, +because it is possible for a malicious leaking server to poison +`/get_missing_events` and other endpoints to get spec conforming +servers to accept events from denied servers without the malicious +leaking server generating any suspicious PDUs themselves. +In this instance, a naive leak detection tool would likely incriminate +the wrong server. + ## Proposal ### The `m.server.knock` authorization rule