Re: [TLS] About encrypting SNI

[Nick Mathewson <[e-mail]>]

On Mon, Apr 14, 2014 at 2:39 PM, Alyssa Rowan <[e-mail]> wrote:
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> On 14/04/2014 18:13, Eric Rescorla wrote:
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>> I'm not sure that this addresses the requests I have heard for SNI
>> encryption which is to conceal the sites people are going to by
>> default rather than as a special case for the privacy conscious.
>
> Precisely.
>
> Tor (for example) wants to look like a common-or-garden browser to
> avoid Eve fingerprinting it (and real, actual jackboots knocking doors
> in as a result). This means, say, browsers should make - and be able
> to make - the most privacy-preserving choices, too. That benefits
> everyone.

[marginally offtopic from the rest of the thread.]

In the case of Tor, that's no longer exactly the case.  We don't want
to deviate _too much_ from typical browser behavior, but we no longer
consider "emulate a browser talking TLS to a webserver" to be a viable
way to achieve censorship-resistance.  We've found, over the years,
that there are simply too many degrees of freedom in TLS and X.509 to
make this trick work well.

Our current link-anticensorship architecture relies instead on a
pluggable layer to handle superencipherment and protocol
obfuscation/emulation.

I don't claim to know what implications this might or might not have
for SNI (non-)encryption.

cheers,
-- 
Nick Mathewson