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Re: [TLS] Deprecate SHA1 for signatures in TLS 1.3 (was Re: TLS 1.3 draft-07 sneak peek)

Dave Garrett <davemgarrett@gmail.com> Mon, 13 July 2015 14:40 UTC

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From: Dave Garrett <davemgarrett@gmail.com>
To: mrex@sap.com
Date: Mon, 13 Jul 2015 10:40:34 -0400
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Subject: Re: [TLS] Deprecate SHA1 for signatures in TLS 1.3 (was Re: TLS 1.3 draft-07 sneak peek)
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On Monday, July 13, 2015 10:30:06 am Martin Rex wrote:
> Section 7.4.1.4 Hello Extensions and its subsections are clearly IRRELEVANT
> for a client that does not use Hello Extensions.

If you want to put it that way, sure, however they are NOT irrelevant for a _server_ that does use hello extensions. This is a direct part of the TLS 1.2 spec, therefore it is very well established that not sending the extension is a direct request for SHA1, and the server supporting this extension is required to interpret it that way. The expectations on what to do in lieu of that working are bad; that's what we want to fix here.


Dave

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