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Re: [TLS] Fully encrypted and authenticated headers (was Re: Encrypting record headers: practical for TLS 1.3 after all?)

Martin Thomson <martin.thomson@gmail.com> Wed, 02 December 2015 05:02 UTC

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Date: Tue, 01 Dec 2015 21:02:34 -0800
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From: Martin Thomson <martin.thomson@gmail.com>
To: Bryan A Ford <brynosaurus@gmail.com>
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Subject: Re: [TLS] Fully encrypted and authenticated headers (was Re: Encrypting record headers: practical for TLS 1.3 after all?)
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On 1 December 2015 at 08:22, Bryan A Ford <brynosaurus@gmail.com> wrote:
> The 2-byte length field in each record's header no longer indicates
> the length of the *current* record but instead indicates the length of
> the *next* record.

Ensuring that you know the length of the *next* record is difficult
and could dramatically degrade latency, or adding extra bogus padding
or extra bogus records.  For instance, I can always send in bursts of
two packets, a one octet packet that promises the remainder of the
burst and one that promises a single octet packet.  At that point, I
get to do what I've always done and you have gained little other than
an increase in packet size of around 19 octets (best case).

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