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Re: [TLS] Comments on the session ticket format in TLS 1.3

Martin Thomson <martin.thomson@gmail.com> Mon, 13 March 2017 00:09 UTC

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From: Martin Thomson <martin.thomson@gmail.com>
Date: Mon, 13 Mar 2017 11:09:23 +1100
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To: Brian Smith <brian@briansmith.org>
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Subject: Re: [TLS] Comments on the session ticket format in TLS 1.3
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On 13 March 2017 at 10:55, Brian Smith <brian@briansmith.org> wrote:
>> So, I'd prefer to bring session IDs back, and
>> to arrange things so that they're always server-generated.
>
> Even in earlier versions, session IDs were not required with
> resumption using tickets. The server sends an empty session ID and the
> client may (should, IMO) send an empty session ID in the resumption
> hello.

This is true, but I believe that there are compatibility reasons to
send the session ID anyway.  I don't know the details, but it probably
comes down to the load balancing thing that Ivan is asking about.

All told, this was a mess in previous versions.  Now we at least have
a hope of maintaining unlinkability.

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