From 06f0d622a97fc969d99a91d95d8f215384155815 Mon Sep 17 00:00:00 2001 From: Patrick Cloke Date: Tue, 15 Jun 2021 13:24:15 -0400 Subject: [PATCH] Clarify membership checking over federation. --- proposals/3083-restricted-rooms.md | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/proposals/3083-restricted-rooms.md b/proposals/3083-restricted-rooms.md index 85ef353c..b3637140 100644 --- a/proposals/3083-restricted-rooms.md +++ b/proposals/3083-restricted-rooms.md @@ -123,8 +123,8 @@ the call to `/join` or `/make_join` / `/send_join` regardless). ### Checking room membership over federation If a server is not in a room (and thus doesn't know the membership of a room) it -cannot enforce membership of a room during a join. Peeking over federation, -as described in [MSC2444](https://github.com/matrix-org/matrix-doc/pull/2444), +cannot enforce membership of a room during a call to `/make_join`, or `/send_join`. +Peeking over federation, as described in [MSC2444](https://github.com/matrix-org/matrix-doc/pull/2444), could be used to establish if the user is in any of the proper rooms. Note that there are additional security considerations with this, namely that @@ -132,8 +132,8 @@ the peek server has significant power. For example, a poorly chosen peek server could lie about the room membership and add an `@evil_user:example.org` to a room to gain membership to a room. -This MSC recommends rejecting the join in this case and allowing the requesting -homeserver to ask another homeserver. +As iterated above, this MSC recommends rejecting the join, potentially allowing +the requesting homeserver to retry via another homeserver. ### Kicking users out when they leave the allowed space