Re: [TLS] draft-ietf-tls-cached-info-02 / New "Fast-Track" draft

Brian Smith <brian@briansmith.org> Thu, 25 February 2010 17:07 UTC

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Date: Thu, 25 Feb 2010 11:09:35 -0600
From: Brian Smith <brian@briansmith.org>
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Subject: Re: [TLS] draft-ietf-tls-cached-info-02 / New "Fast-Track" draft
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Stefan Santesson wrote:
> Simon,
>
> Note that the requirement is MUST support, it is not MUST use.
> It is perfectly allowed to use SHA-256.
>
> Does that solve your concern?
This doesn't make sense. If the server doesn't implement SHA-1, then a 
client that only sends SHA-1 to it won't be able to use the extension 
effectively. If the client cannot rely on SHA-1 working then what is the 
value of the "MUST" requirement? Similarly, if the client doesn't 
implement SHA-1, but the server only supports SHA-1, then they won't be 
able to take advantage of the optimization.

- Brian