[tor-bugs] #33336 [Circumvention/Snowflake]: Trial deployment of Snowflake with Turbo Tunnel

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#33336: Trial deployment of Snowflake with Turbo Tunnel
-------------------------------------+--------------------------
 Reporter:  dcf                      |          Owner:  dcf
     Type:  task                     |         Status:  accepted
 Priority:  Medium                   |      Milestone:
Component:  Circumvention/Snowflake  |        Version:
 Severity:  Normal                   |     Resolution:
 Keywords:  turbotunnel              |  Actual Points:
Parent ID:                           |         Points:
 Reviewer:                           |        Sponsor:
-------------------------------------+--------------------------

Comment (by dcf):

 Replying to [comment:12 dcf]:
 > I can try doing another Tor Browser build with a more recent version of
 quic-go, assuming I can find a new enough version of quic-go that is also
 compatible with pion-quic (which
 [https://github.com/pion/quic/blob/v0.1.1/go.mod#L4 currently specifies]
 the old version from 2019-04-01).

 I have a couple of updated branches and I'm starting on Tor Browser builds
 with them. They make the kcp idle timeout fix from comment:14 and update
 to a newer quic-go as mentioned in comment:12.

  * [https://gitweb.torproject.org/user/dcf/snowflake.git/log/?h
 =turbotunnel-kcp&id=90746c1c3fce5db371038b092c32abb548504d9d turbotunnel-
 kcp]
  * [https://gitweb.torproject.org/user/dcf/snowflake.git/log/?h
 =turbotunnel-quic&id=42c07f2c140e4c6f1f752329a67fdf15cd6bd8c5 turbotunnel-
 quic]

 The upgrade of quic-go was a bit of a gross process. The
 [https://gitweb.torproject.org/user/dcf/snowflake.git/commit/?h
 =turbotunnel-quic&id=42c07f2c140e4c6f1f752329a67fdf15cd6bd8c5 API changes]
 are mild. pion-quic is unfortunately incompatible with the newer version;
 but I worked around that with a patch in the tor-browser-build project. I
 selected a very specific commit of quic-go to upgrade to: we need at least
 [https://github.com/lucas-clemente/quic-
 go/commit/6407f5bf680283bf7e3755976306767da2c55e66 6407f5bf] because it
 has the keepalive fix for comment:12 and those in #33401. But I didn't
 want to use [https://github.com/lucas-clemente/quic-
 go/commit/572ef44cf2d1197428f493e90cdfdd161e584f2c 572ef44c] or later,
 because it adds a huge number of new transitive dependencies that I didn't
 have the ambition to start packaging for tor-browser-build. (It's a
 ''lot'' of dependencies—`go mod graph` goes from 59 lines to 283 lines.
 And one of the dependencies—google.golang.org/api—is over 550 MB!)
 Upgrading quic-go also requires upgrading go itself to 1.13, because the
 qtls library is coupled to crypto/tls in the standard library. The
 upgraded client was not compatible with the server I deployed in
 comment:8, so I rebuilt the server at commit
 [https://gitweb.torproject.org/user/dcf/snowflake.git/log/?h=turbotunnel&id=42c07f2c140e4c6f1f752329a67fdf15cd6bd8c5
 42c07f2c] and deployed it at 2020-02-22T04:13:
 {{{
 lrwxrwxrwx 1 root root       37 Feb 22 04:12 snowflake-server ->
 snowflake-server.turbotunnel.42c07f2c
 -rwxr-xr-x 1 root root  9067083 Feb 18 23:18 snowflake-server.normal
 -rwxr-xr-x 1 root root 15648527 Feb 22 04:11 snowflake-
 server.turbotunnel.42c07f2c
 -rwxr-xr-x 1 root root 12459290 Feb 19 18:01 snowflake-
 server.turbotunnel.da37211c
 }}}
 Overall, it's making me feel more and more meh about deploying quic-go; it
 and QUIC are still changing fast and I foresee maintenance and
 compatibility difficulties.

 In the new Tor Browser builds I'm going to enable snowflake-client logging
 by default and enable some torrc options to try and make tor more
 reluctant to give up on its circuits. The latter idea I got from the
 [http://meetbot.debian.net/tor-meeting/2020/tor-
 meeting.2020-02-20-18.00.log.html#l-32 2020-02-20 anti-censorship meeting]
 (staring at about 18:10:00).
 {{{
 LearnCircuitBuildTimeout 0
 CircuitBuildTimeout 300
 CircuitStreamTimeout 300
 }}}

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/33336#comment:15>
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