Re: [TLS] Making post-handshake messages optional in TLS 1.3 (#676)

Hannes Tschofenig <hannes.tschofenig@gmx.net> Wed, 12 October 2016 08:36 UTC

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To: Ilari Liusvaara <ilariliusvaara@welho.com>, Daniel Kahn Gillmor <dkg@fifthhorseman.net>
References: <CAOjisRznhk-Fww=EnRg7zXO-zaHWyNgi0g+reRBj+y3ZOhwMhw@mail.gmail.com> <d267aa85-56fc-b7b0-dc1f-3373f3b0c563@gmx.net> <CAOjisRxMAyzEVG_0THV9q6R9EHtPNKk94OB+pOzH_Q3kyi-ZQg@mail.gmail.com> <87fuo2vy81.fsf@alice.fifthhorseman.net> <20161012081724.GB16436@LK-Perkele-V2.elisa-laajakaista.fi>
From: Hannes Tschofenig <hannes.tschofenig@gmx.net>
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Date: Wed, 12 Oct 2016 10:36:01 +0200
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Subject: Re: [TLS] Making post-handshake messages optional in TLS 1.3 (#676)
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I agre with Ilari. Currently, the way to reject a request is more than
just saying "no, thanks.".

On 10/12/2016 10:17 AM, Ilari Liusvaara wrote:
> On Wed, Oct 12, 2016 at 03:10:54AM -0400, Daniel Kahn Gillmor wrote:
>>
>> I don't think it's too much to ask that implementations be able to
>> reject a post-handshake CertificateRequest gracefully, even if they have
>> no intention of ever implementing a proper Client Certificate response.
> 
> Unfortunately, currently it is too much:
> 
> One can't just send a message saying "NAK CertficiateRequest X", since
> that message is followed by Finished message, that is quite annoying
> to compute (even requires forkable hash, when nothing else requires
> that, and if one is to be able to freeze connection, requires very
> exotic features from hash implementation.
> 
> 
> -Ilari
>