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Re: [TLS] Maximum Fragment Length negotiation

Martin Thomson <martin.thomson@gmail.com> Wed, 30 November 2016 22:43 UTC

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From: Martin Thomson <martin.thomson@gmail.com>
Date: Thu, 01 Dec 2016 09:43:54 +1100
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To: Hubert Kario <hkario@redhat.com>
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Subject: Re: [TLS] Maximum Fragment Length negotiation
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Asking ALL TLS implementations to change to accommodate these things
is a pretty blunt instrument.  I want to be sure that this is
necessary.  (FWIW, I think that this is a reasonable request, I would
probably be OK with a smaller maximum by default even.)

On 1 December 2016 at 00:22, Hubert Kario <hkario@redhat.com> wrote:
> On Wednesday, 30 November 2016 11:20:01 CET Martin Thomson wrote:
>> On 30 November 2016 at 05:54, Thomas Pornin <pornin@bolet.org> wrote:
>> > Any comments?
>>
>> I'm ambivalent on this generally: though I think that the general
>> notion is OK, I'm not sure about the details.
>>
>> In particular, you need to be clearer in your motivations: the point
>> is to ensure that little things (really little things) can talk to any
>> other TLS implementation.  That seems inherently good, but it might
>> pay to dig into that some more: why is that good?
>
> because if they can't use TLS, they will create a bespoke protocol, and those
> have a tendency of being completely broken, on conceptual level, let alone
> implementation
>
> combine it with the fact that "trusted network" doesn't exist any more and you
> end up with solutions that are insecure with nobody using them knows they are
> insecure, especially in IoT space
> --
> Regards,
> Hubert Kario
> Senior Quality Engineer, QE BaseOS Security team
> Web: www.cz.redhat.com
> Red Hat Czech s.r.o., Purkyňova 99/71, 612 45, Brno, Czech Republic

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