[tor-bugs] #28942 [Circumvention/Snowflake]: Evaluate pion WebRTC

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#28942: Evaluate pion WebRTC
--------------------------------------------+------------------------------
 Reporter:  backkem                         |          Owner:  cohosh
     Type:  enhancement                     |         Status:  accepted
 Priority:  Medium                          |      Milestone:
Component:  Circumvention/Snowflake         |        Version:
 Severity:  Normal                          |     Resolution:
 Keywords:  anti-censorship-roadmap-august  |  Actual Points:
Parent ID:                                  |         Points:  5
 Reviewer:                                  |        Sponsor:
                                            |  Sponsor28-must
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Comment (by cohosh):

 Replying to [comment:43 dcf]:
 Thanks for looking into this!
 > I did a `make testbuild` using the pion-webrtc branch at
 0f31d1bcfd71bba9ef27fab3b5a6d3231c60213d and put the outputs, including
 checksums, here:
 >   https://people.torproject.org/~dcf/pt-bundle/tor-browser-pion-
 webrtc-20190829-0f31d1bcfd/
 >
 > Everything builds, and from the command line I can run `snowflake-client
 -h` and see that it produces output, but unfortunately it doesn't
 bootstrap for me. But then again, neither does
 [https://github.com/cohosh/snowflake/commit/3cc240625cad22db02eca7af41b139606c13147d
 3cc240625c] from cohosh's pion branch from comment:28. So whatever is
 going wrong for me, is possibly not related to the rbm build.
 >
 > This is what I see in the snowflake-client log. After this, there's no
 more output for at least several minutes (that's as long as I waited).
 > {{{
 > 2019/08/29 01:43:47 Rendezvous using Broker at: https://snowflake-
 broker.bamsoftware.com/
 > 2019/08/29 01:43:47 WebRTC: Collecting a new Snowflake. Currently at
 [0/3]
 > 2019/08/29 01:43:47 snowflake-UQ9COqlX3fZ5JMmA  connecting...
 > 2019/08/29 01:43:47 Started SOCKS listener.
 > 2019/08/29 01:43:47 SOCKS listening...
 > 2019/08/29 01:43:47 WebRTC: PeerConnection created.
 > 2019/08/29 01:43:47 WebRTC: DataChannel created.
 > 2019/08/29 01:43:47 WebRTC: Created offer
 > 2019/08/29 01:43:47 WebRTC: Set local description
 > 2019/08/29 01:43:48 SOCKS accepted:  {[scrubbed]   map[]}
 > }}}

 Noting that I can reproduce this issue seemingly 100% of the time, I'll
 investigate whether it's due to recent changes to any of the pion
 libraries, since bootstrapping used to work

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/28942#comment:44>
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