[tor-project] Anti-censorship team monthly report: June 2019

[Philipp Winter]

Hi everyone,

Here's a summary of the anti-censorship team's progress in June:

BridgeDB
========

* Blacklisted 53 bridges whose obfs4 port was unreachable.  Most of
  these bridges had no contact info.  Some did, but the operators did
  not respond to our emails.

* Tried to understand why BridgeDB responded to many requests with no
  bridges: <https://bugs.torproject.org/30441>
  - Eventually, the problem seems to have fixed itself.
  - We'll keep a close eye on the logs.

* After hearing back from Tor's research safety board, we implemented a
  new feature that lets BridgeDB export statistics:
  <https://bugs.torproject.org/9316>
  The feature is currently under review.

* Removed support for Yahoo email accounts:
  <https://bugs.torproject.org/28496>

* Published a blog post about BridgeDB's new 0.7.1 release:
  <https://blog.torproject.org/new-release-bridgedb-071>

Snowflake
=========

* We released a prototype for snowflake's webextension!  For Firefox,
  you can get it here:
  <https://addons.mozilla.org/en-US/firefox/addon/torproject-snowflake/>
  We're still working on getting it published in Chrome's web store.
  By installing the addon, you turn your browser into a circumvention
  proxy for censored users.

* Working on integrating pion/webrtc to ease builds and reduce
  dependencies: <https://bugs.torproject.org/28942>

* We wrapped up a ticket to collect statistics on snowflake's broker:
  <https://bugs.torproject.org/21315>

* Brainstormed mechanism for snowflake update versioning:
  <https://bugs.torproject.org/30704>

Pluggable transports
====================

* Implemented a patch to reorder PT/proxy phases:
  <https://bugs.torproject.org/28930>
  The patch is currently under review.

* Brainstormed ideas for obfs4's successor:
  <https://bugs.torproject.org/30716>
  - We decided to first study the "long tail" of network traffic because
    it will allow us to make better design decisions:
    <https://bugs.torproject.org/30986>

* We made some progress on improving our PT spec:
  <https://bugs.torproject.org/29285>
  - For now, we have been collecting a list of issues with the v1 spec.

* We made some progress with loading shared libraries for PTs into the
  Tor executable (on Linux for now).

Miscellaneous
=============

* Deployed <https://bridges.torproject.org/scan/>.  The service allows
  obfs4 operators to test the reachability of their obfs4 port -- at
  least until we are done with the following ticket:
  <https://bugs.torproject.org/30477>

* We wrapped up our "does the GFW block obfs4?" ticket:
  <https://bugs.torproject.org/29279>
  The answer is: no.

* Published a blog post that introduces our anti-censorship team and our
  Sponsor 19 report:
  <https://blog.torproject.org/tors-new-anti-censorship-team-defending-open-internet>

* Asked tor-relays@ to set up more obfs4 bridges:
  <https://lists.torproject.org/pipermail/tor-relays/2019-June/017419.html>

* Worked with a handful operators whose obfs4 bridges were broken.
  Several operators believed that only a bridge's OR port must be
  externally reachable.  Others forgot to configure port forwarding for
  their obfs4 port.