Re: [TLS] CCS and key reset and renegotiation

Viktor Dukhovni <viktor1dane@dukhovni.org> Thu, 05 June 2014 17:43 UTC

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Date: Thu, 5 Jun 2014 17:43:12 +0000
From: Viktor Dukhovni <viktor1dane@dukhovni.org>
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Subject: Re: [TLS] CCS and key reset and renegotiation
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On Thu, Jun 05, 2014 at 08:23:46PM +0300, Yoav Nir wrote:

> > I don't recall whether this idea got dropped, or whether
> > STOPTLS might yet happen in TLS 1.3.  Anyone care to bring me up
> > to speed?
> 
> Sure. 

Thanks.

> StopTLS would need some mechanism to prevent a Dispensa/Ray/Rex
> prefix injection attack.

Would it suffice to ban application-data messages after STOPTLS
before a new handshake completes, and to require a subsequent
handshake to be a resumption of the previous session (or a new
session handshake in cleartext, but channel-bound to the previous
session).

The purpose of STOPTLS would not be a downgrade to cleartext data
tranfer, but rather a transition from one key-set to another via
a cleartext handshake that can happen with minimal crypto-state
transfer (saved session object or some opaque shared secret
sufficient).

> It's not currently a part of any plan for any version of TLS.

If it does come back, I can put it to good use.

-- 
	Viktor.