Key rotation within continuation

[jricher]

§5 Continuing a Grant Request: Editor's note:

We need to have a secure way to rotate the key used for the continuation here. In most cases this will be a rotation for the client instance, since a client without an instance record would likely just present a new key for a new request. In that case it could go with the client management, above - but it doesn't necessarily have to be.

[TomCJones]

See my comment on pull request #132
I think we need to find a single rotation recovery method.
I collected my ideas here: https://tcwiki.azurewebsites.net/index.php?title=Recovery#Proposed_for_Standardization

[fimbault]

This is close to what I was thinking about. I would also add as a reference what KERI is doing on key rotation, for discussion purposes.

[jricher]

Key rotation is now handled on the continuation access token, not as part of the grant update. See #435

[adeinega]

Could you answer on #435 (comment) and other comments in this PR? Thank you.

[fimbault]

what do you mean by "more or less gracefully" ?

[adeinega]

@fimbault, you can omit "more or less gracefully", I wanted to know if GNAP allows to address the use case I provided

It could be useful when there are multiple running instances of the client and it's tough, or even impossible, to update the keys on all these instances immediately (just as an example, the client instance could be deployed as a service in K8S).

and

am I right that previous_key becomes immediately invalid?

[fimbault]

Indeed the idea currently is that previous-key is replaced by the new key, for all what's coming afterwards.
I know of some systems that allow a delay during which both versions coexist, is that what you're after ?

[adeinega]

There are plenty of systems where both, or even more versions coexist until an administrator or a client itself decides to remove/invalidate previous keys. That's correct.

The same approach arguably is even way more valuable for RSs. BTW, are you planning to allow them to rotate their own keys?

You are writing these specs, and IMO, you still have time to add & embed these features into the core of GNAP.