Re: [TLS] A closer look at ROBOT, BB Attacks, timing attacks in general, and what we can do in TLS

Hanno Böck <hanno@hboeck.de> Fri, 15 December 2017 16:57 UTC

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Date: Fri, 15 Dec 2017 17:57:48 +0100
From: Hanno =?UTF-8?B?QsO2Y2s=?= <hanno@hboeck.de>
To: Kathleen Moriarty <kathleen.moriarty.ietf@gmail.com>
Cc: Nikos Mavrogiannopoulos <nmav@redhat.com>, "<tls@ietf.org>" <tls@ietf.org>
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Subject: Re: [TLS] A closer look at ROBOT, BB Attacks, timing attacks in general, and what we can do in TLS
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On Fri, 15 Dec 2017 11:47:54 -0500
Kathleen Moriarty <kathleen.moriarty.ietf@gmail.com>; wrote:

> Is there a reason why a migration to PCKS #1 v2.2 doesn't help for TLS
> 1.2 and prior? I haven't noticed any discussion on that previously. Is
> it just the code base and not those using it being unwilling to
> upgrade supporting libraries?

It depends... particularly if we talk about encryption or signatures.

With Bleichenbacher attacks there are plenty of cross-protocol attack
possibilities, this was one of the papers at the TRON workshop:
https://www.nds.rub.de/media/nds/veroeffentlichungen/2015/08/21/Tls13QuicAttacks.pdf


While I believe we certainly can't get rid of PKCS #1 1.5 signatures
any time soon, I think we can get rid of PKCS #1 1.5 encryption (at
least on the server side for HTTPS). The number of legit connections is
really low.

If you run servers please check if you can do that. (I'm also
considering writing an RSA-kex-diediedie RFC when I find time for it.)

-- 
Hanno Böck
https://hboeck.de/

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