This meant that if you had set the directory structure, than it would
always deserialize as "Flat".
We also migrate the newly migrated media to the deep directory structure,
if configured.
You may notice that we do no database migration for populating the state cache for knocking.
This is because that in all the places where we use the state cache, it doesn't make a difference:
- For local users, the clients wouldn't have been able to knock on rooms, as the `/knock`
endpoint wasn't implemented yet, and I am not aware of any client which tries to knock over
`/state`, as it would fail if the server is not currently in the room
- It is not used for remote users
Previously, we only fetched keys once, only requesting them again if we have any missing, allowing for ancient keys to be used to sign PDUs and transactions
Now we refresh keys that either have or are about to expire, preventing attacks that make use of leaked private keys of a homeserver
We also ensure that when validating PDUs or transactions, that they are valid at the origin_server_ts or time of us receiving the transaction respectfully
As to not break event authorization for old rooms, we need to keep old keys around
We move verify_keys which we no longer see in direct requests to the origin to old_verify_keys
We keep old_verify_keys indefinitely as mentioned above, as to not break event authorization (at least until a future MSC addresses this)
`IndexMap::remove` was deprecated in favor of explicitly named methods.
I assume that we actually needed to be using `shift_remove`, otherwise
we probably wouldn't be bothering with `indexmap` here in the first
place. I wonder if this fixes any bugs lol
It comes with a bunch of new lints (yay!) so I fixed them all so CI will
keep working.
Also apparently something about linking changed because I had to change
the checks for deciding the linker flags for static x86_64 builds to
keep working.
