Re: [webauthn] Specify the set of hash algorithms UAs can select between.

In general, it's useful to have a story re: algorithm agility, and that goes far beyond "just parameterize them".  That story needs to include specific instructions for what to do when a new, previously unknown algorithm appears and when no known algorithms appear.  Ideally, it would address downgrade attacks.  

[RFC7696](https://tools.ietf.org/html/rfc7696#section-2.4) (Guidelines for Cryptographic Algorithm Agility and Selecting Mandatory-to-Implement Algorithms) is relevant, though it's really not a great reference.  I'll see if I can find something better.

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Received on Friday, 19 May 2017 01:33:54 UTC