Cross signing key updates fail on workerised synapse

[dbkr]

When an EDU comes in with updated cross-signing keys for a user, it's handled by the federation_inbound worker which lacks the ability to write the keys to the db. Stack trace: https://gist.github.com/dbkr/d93c32abab600ff3c7a240c0de0f1d61

@erikjohnston sez:

ah, looks like we're incorrectly registering an edu handler on workers when it should only happen on master

This affects ability to cross-sign to/from matrix.org so is time-sensitive.

[jryans]

@dbkr Does this also mean affected users would need re-create their keys after a fix is found, or do the keys keep coming in over federation until you save them correctly...?

[dbkr]

I'm not 100% sure: I suspect there is more to this because the keys should also get written into the cache when the client does a /keys/query. Suggest we re-test once this if fixed.

[anoadragon453]

Unfortunately the above fix doesn't seem to be the silver bullet we thought it would be.

[richvdh]

so the Failed to handle edu error (with stack trace) is still happening?

[dbkr]

I believe this bug is now fixed (ie. the stack trace is no longer appearing and the EDU is getting through) but the riot-web bug element-hq/element-web#12973 is still a problem. Closing this and opening #7276 for the wider problem.