This fixes a vulnerability where an attacker with a malicious remote
server and a user on the local server can trick the local server into
signing arbitrary events. The attacker issue a remote leave as the local
user to a room on the malicious server. Without any validation of the
make_leave response, the local server would sign the attacker-controlled
event and pass it back to the malicious server with send_leave.
The join and knock endpoints are also fixed in this commit, but are less
useful for exploitation because the local server replaces the "content"
field returned by the remote server. Remote invites are unaffected
because we already check that the event returned from /invite has the
same event ID as the event passed to it.
Co-authored-by: timedout <git@nexy7574.co.uk>
Co-authored-by: Jade Ellis <jade@ellis.link>
Co-authored-by: Ginger <ginger@gingershaped.computer>
Add support for the m.replace and m.reference bundled
aggregations.
This should fix plenty of subtle client issues.
Threads are not included in the new code as they have
historically been written to the database. Replacing the
old system would result in issues when switching away from
continuwuity, so saved for later.
Some TODOs have been left re event visibility and ignored users.
These should be OK for now, though.
Also fixes:
- Transaction IDs leaking in event route
- Age not being set for event relations or threads
- Both of the above for search results
Notes down concern with relations table
What's missing? Being able to use separate rooms & lists for typing
indicators.
At the moment, we use the same ones as we use for the timeline, as
todo_rooms is quite intertwined. We need to disentangle this to get that
functionality, although I'm not sure if clients use it.
- Remove most usages of `update_membership` in favor
of directly calling the `mark_as_*` functions
- Store the leave membership event as the value in the
`userroomid_leftstate` table
- Use the `userroomid_leftstate` table to synchronize the
timeline and state for left rooms if possible
