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Re: [TLS] Alternative ESNI?

Eric Rescorla <ekr@rtfm.com> Sat, 15 December 2018 21:30 UTC

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From: Eric Rescorla <ekr@rtfm.com>
Date: Sat, 15 Dec 2018 13:30:18 -0800
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To: IETF TLS WG <tls@ietf.org>
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Subject: Re: [TLS] Alternative ESNI?
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On Sat, Dec 15, 2018 at 12:01 PM Viktor Dukhovni <ietf-dane@dukhovni.org>
wrote:

>
>
> > On Dec 15, 2018, at 8:08 AM, Stephen Farrell <stephen.farrell@cs.tcd.ie>
> wrote:
> >
> > I don't see any point in considering the variant with the easy
> > active attack though;
>
> For the record the easy MiTM attack requires on-path TCP termination,
> only discloses the SNI name, and the full handshake then fails.  It
> looks to me like the same happens with the current draft when the
> fronting key_share is not DNSSEC-validated.


As I said in my response to Nico, it depends on the threat model. If your
concern is the local network (which is quite common), then DoH addresses
the issue.

-Ekr

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