Duo plugin 1.3 - Duo Health Check and the recent Duo outage on 21 AUG 2023

[Cantor, Scott]

> It should however 'fail closed’ (skip the redirect) if that check either
> produces an error from Duo's response, or the client experiences an IO
> exception. If it did not, that would be a bug I suspect. 

Notably, it fails closed. It just skips the rest of the flow and signals back a failure event to the calling flow, typically MFA. It doesn't fail open and there's no explicitly option for that, it assumes your calling flow is prepared to handle a non-success in whatever manner expected.

It's possible that some have misunderstood that and expected things to just proceed happily, but that would take more work and planning.

-- Scott