Re: [TLS] Encrypting record headers: practical for TLS 1.3 after all?

Eric Rescorla <> Wed, 02 December 2015 14:13 UTC

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From: Eric Rescorla <>
Date: Wed, 02 Dec 2015 06:12:43 -0800
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To: Yoav Nir <>
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Subject: Re: [TLS] Encrypting record headers: practical for TLS 1.3 after all?
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On Wed, Dec 2, 2015 at 5:38 AM, Yoav Nir <> wrote:
> I don’t think Bryan’s proposal will hurt the capabilities of a Check Point
> firewall, and it will make life difficult for me as a developer no more
> than it will make life difficult for developers of OpenSSL, NSS, SChannel,
> or any of a dozen other TLS implementations. I don’t know about the other
> IDS/IPS/Firewall devices.

The people who will be inconvenienced (if any) by changing the record
framing in an
externally visible way are not largely developers of middleboxes or stacks
rather (1) users and (2) client vendors and (3) server operators, who have
deal with connections being arbitrarily broken and/or damaged by inspection
devices which expect to be able to observe packet framing.

In Seattle, when the topic of stripping off the fixed three bytes of the
header came up (which would have had a similar impact), we agreed to defer
it until we had measurements for the level of breakage that it would cause
(an experiment which we at Mozilla are on the hook for). It seems to me that
this question should be handled similarly.