Re: [TLS] 0RTT and HelloRetryRequest (Re: Narrowing the replay window)

Martin Thomson <martin.thomson@gmail.com> Sat, 02 April 2016 01:13 UTC

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Date: Sat, 2 Apr 2016 12:13:42 +1100
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From: Martin Thomson <martin.thomson@gmail.com>
To: Ilari Liusvaara <ilariliusvaara@welho.com>
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Subject: Re: [TLS] 0RTT and HelloRetryRequest (Re: Narrowing the replay window)
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On 1 April 2016 at 03:46, Ilari Liusvaara <ilariliusvaara@welho.com> wrote:
>
>> > I believe Option #2 is simplest.
>>
>> I didn't mention this because I was composing on a phone at the time,
>> but we have to decide whether to allow a second attempt at 0-RTT.  If
>> we do, then the effect is a two round trip setback.  I think that the
>> odds of this happening are small, so I'm OK with it, but I wanted to
>> highlight that.
>
> Not taking it could mix poorly with DTLS, as DTLS rejects need to be
> stateless from server POV.

I thought that we'd already established that this is entirely possible.