Re: [Masque] MASQUE and Tor "pluggable transports"

Ben Schwartz <bemasc@google.com> Tue, 06 August 2019 16:36 UTC

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From: Ben Schwartz <bemasc@google.com>
Date: Tue, 6 Aug 2019 12:36:06 -0400
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Subject: Re: [Masque] MASQUE and Tor "pluggable transports"
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Pluggable Transports generally work between special-purpose, cooperating
clients and servers, so standardization is not necessary.  MASQUE, in some
future form, could be a useful basis for a pluggable transport, but I don't
think it makes sense to focus on PT during the standards development
process.

If you're interested in HTTP-like pluggable transports, I suggest looking
at https://github.com/sergeyfrolov/httpsproxy.  Once MASQUE is fully
specified, I expect we'll see transports like httpsproxy utilizing MASQUE
if there is demand.  However, for Tor's purposes, a MASQUE-based transport
is unlikely to represent an improvement over httpsproxy.

On Tue, Aug 6, 2019 at 12:20 PM Philipp Winter <phw@torproject.org>; wrote:

> Hi everyone,
>
> I read the most recent MASQUE draft that I found here:
> <https://davidschinazi.github.io/masque-drafts/draft-schinazi-masque.html>
> It's great work, thanks for this!
>
> Section 2.4 suggests onion routing on top of MASQUE servers to add
> anonymity.  There may be an easier way to accomplish this: one could
> turn MASQUE into a "pluggable transport" protocol.  Originally developed
> by Tor, pluggable transports are a traffic obfuscation mechanism that
> puts a proxy in front of both a client and a server.  These proxies
> disguise the traffic that's exchanged between client and server as shown
> in the following diagram:
> <https://gitweb.torproject.org/torspec.git/tree/pt-spec.txt#n61>
>
> Turning MASQUE into a pluggable transport would make it easy-ish to
> integrate for systems that support the pluggable transport specification
> including Tor, Psiphon, and Lantern.  MASQUE would also benefit from
> security properties offered by its "host" system -- in Tor's case this
> would be anonymity.
>
> Practically speaking, a user would start Tor Browser with the MASQUE
> pluggable transport (which would be included in Tor Browser).  A
> rendez-vous mechanism would inform the user about MASQUE servers that
> she could use.  Once a MASQUE server receives the user's HTTPS data, the
> server extracts the content and shoves it into a Tor bridge that's
> running on the same (or potentially a different) machine.  All of this
> could be implemented as part of a new module for the obfs4proxy system,
> which is the pluggable transport proxy that the Tor project uses:
> <https://gitlab.com/yawning/obfs4>
>
> Is there interest in pursuing support for pluggable transports?
>
> Cheers,
> Philipp
>
> --
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