It's possible for a server to have multiple associated public keys. This can happen when a Matrix server is set up on a particular domain, its key is lost, and the server continues running on the domain. Now there will be two keys associated to the domain. The old logic wouldn't fetch the new key if we already had the old key cached. The new logic will fetch any keys we don't have that we need, rather than just fetching one key per server.
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)
Original patch by Matthias. Benjamin just rebased it onto grapevine and
fixed clippy/rustc warnings.
Co-authored-by: Benjamin Lee <benjamin@computer.surgery>
Unfortunately we need to pull tracing-opentelemetry from git because
there hasn't been a release including the dependency bump on the other
opentelemetry crates.
This change is fully automated, except the `rustfmt.toml` changes and
a few clippy directives to allow specific functions with too many lines
because they are longer now.
Functions using `services()` are allowed to pointlessly take `self`
because the existence of `services()` is a crime and the solution is
making the types store references to their dependencies and then going
through `self`, so just allowing the lint saves us from modifying some
code only to switch it back later. Much later. Getting rid of
`services()` will probably be an ordeal.
