Re: [TLS] draft-ietf-tls-tls13-16

Adam Langley <> Wed, 28 September 2016 17:06 UTC

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From: Adam Langley <>
Date: Wed, 28 Sep 2016 10:06:35 -0700
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To: "Salz, Rich" <>
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Subject: Re: [TLS] draft-ietf-tls-tls13-16
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On Wed, Sep 28, 2016 at 9:37 AM, Salz, Rich <> wrote:
> On the crypto-library side, boringSSL had equivalence classes so you could specify that by configuring the CIPHER list. If running in a server, and the configured ciphers were like "[AES:CHACHA]:3DES:RC4" for example, then either AES or ChaCha would be picked.  I don't know if Google servers use that, but I'd be a bit surprised if they didn't.
> As for OpenSSL, we need to figure out something.  The "ciphers" syntax is showing its age.

The equal-preference groupings have worked pretty well for us in terms
of making the right thing happen and being understandable to
non-experts. I certainly agree that the ciphers mini-language could do
with some renewal overall.

But I think a lot of the need for it is also going away. We've spent
years worrying about should we do forward security? Do we put RC4
ahead of AES-CBC because of BEAST / POODLE / etc? What about the poor
performance of AES-GCM with Java (for a while)?

But since we've now drastically reduced the number of options, and
those options are (fingers crossed) less shitty than before, I'd hope
that a default would work for the vast majority of TLS 1.3 users.



Adam Langley