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Re: [TLS] Record header size?

"Short, Todd" <tshort@akamai.com> Tue, 17 November 2015 20:59 UTC

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From: "Short, Todd" <tshort@akamai.com>
To: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Thread-Topic: [TLS] Record header size?
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Date: Tue, 17 Nov 2015 20:59:11 +0000
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Subject: Re: [TLS] Record header size?
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I would say that 32-bits would be optimal, since that is the typical word-size of processors that need alignment. 2-bytes isn’t much better than 5-bytes in this regard.
--
-Todd Short
// tshort@akamai.com<mailto:tshort@akamai.com>
// "One if by land, two if by sea, three if by the Internet."

On Nov 17, 2015, at 3:45 PM, Daniel Kahn Gillmor <dkg@fifthhorseman.net<mailto:dkg@fifthhorseman.net>> wrote:

On Tue 2015-11-17 12:09:30 -0500, Eric Rescorla wrote:
The concern here is backward compatibility with inspection middleboxes which
expect the length field to be in a particular place. We agreed in Seattle to
wait for early deployment experience before modifying the header to move
the length.

In particular, if we're going to make a change to the TLS record header,
the change would be to remove the version and the type entirely, leaving
only two octets of length on each record.  Is a two-octet offset going
to be problematic?

        --dkg

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