38 lines
2.2 KiB
Markdown
38 lines
2.2 KiB
Markdown
# MSC3821: Update redaction rules, again
|
|
|
|
[MSC2176](https://github.com/matrix-org/matrix-spec-proposals/pull/2176) aimed to fix inconsistencies
|
|
with the [redaction algorithm](https://spec.matrix.org/v1.6/rooms/v10/#redactions) where server-side
|
|
event auth required properties to exist that were being removed. While MSC2176 fixed a number of cases,
|
|
one was unfortunately missed.
|
|
|
|
This MSC aims to fix that missing case, originally identified long ago by [synapse#1831](https://github.com/matrix-org/synapse/issues/1831).
|
|
|
|
## Proposal
|
|
|
|
*Note*: It is recommended to read [MSC2176](https://github.com/matrix-org/matrix-spec-proposals/pull/2176)
|
|
before this proposal as MSC2176 contains a lot of backing context.
|
|
|
|
In a future room version, the following changes are made to the [redaction algorithm](https://spec.matrix.org/v1.6/rooms/v10/#redactions).
|
|
Note that this requires a new room version because changing the redaction algorithm changes how
|
|
[event IDs](https://spec.matrix.org/v1.6/rooms/v10/#event-ids) are calculated, as they are
|
|
[reference hashes](https://spec.matrix.org/v1.6/server-server-api/#calculating-the-reference-hash-for-an-event)
|
|
which redact the event during calculation.
|
|
|
|
* [`m.room.member`](https://spec.matrix.org/v1.6/client-server-api/#mroommember) events preserve a portion
|
|
of `third_party_invite` under `content`, if present. Those properties being:
|
|
|
|
* `signed`: the block is required for the server to validate the event, however excess adjacent properties
|
|
such as `display_name` are not important.
|
|
|
|
Clients should note that because `display_name` is *not* preserved during redaction they might need to change
|
|
how that event is rendered/presented to users. For example, when rendering such a redacted event the client
|
|
might show it as "Bob accepted a third party invite".
|
|
|
|
## Unstable prefix
|
|
|
|
Implementations looking to test these changes before adopted into a stable room version should use
|
|
`org.matrix.msc3821.opt1` as the room version, using **v9** as a base and treating it as unstable.
|
|
|
|
**History**: This MSC was originally written before room version 10 existed. Implementations wishing to use
|
|
v10 as a base instead of v9 should use `org.matrix.msc3821.opt1.v10` as the room version instead.
|