[tor-project] Anti-censorship team monthly report: December 2020

[Cecylia Bocovich]

Hi everyone,

Here's our monthly report on anti-censorship work:


Snowflake
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* Improved throughput bottlenecks in Snowflake.

https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/-/issues/40026

* Updated webrtc version in Snowflake.

https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/-/issues/40027

Rdsys
-----

* Implemented an initial set of prometheus metrics.
  https://gitlab.torproject.org/tpo/anti-censorship/rdsys/-/issues/14

* Refactored the way rdsys interacts with bridgestrap, so rdsys no
longer accumulates goroutines if bridgestrap does not respond.
  https://gitlab.torproject.org/tpo/anti-censorship/rdsys/-/issues/30

* Spent some time experimenting with a persistence layer for rdsys.
More work is necessary though.
  https://gitlab.torproject.org/tpo/anti-censorship/rdsys/-/issues/5

Bridgestrap
-----------

* Implemented more idiomatic prometheus metrics.
  https://gitlab.torproject.org/tpo/anti-censorship/bridgestrap/-/issues/10

* Finished deploying bridgestrap.
  https://gitlab.torproject.org/tpo/anti-censorship/bridgestrap/-/issues/5

* Realised that tor's dormant mode breaks bridgestrap and implemented a
workaround.
  https://gitlab.torproject.org/tpo/anti-censorship/bridgestrap/-/issues/12

obfs4proxy
----------

* Dealt with an unexpected failure in obfs4proxy. Microsoft rotated its
Azure certificates, which were pinned in obfs4proxy, resulting in
obfs4proxy rejecting connections to Azure. That broke both meek-azure
and moat in Tor Browser.  We updated obfs4proxy's pinned certificates
and worked with the Tor Browser team to push out an emergency update.

https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/meek/-/issues/40001

* obfs4proxy has an -unsafeLogging command line switch which didn't
actually work.  We wrote a patch that makes it work.
  https://gitlab.com/yawning/obfs4/-/merge_requests/1

Other
-----

* Discussed building and integrating a new PT with the creators of Protozoa

* Added rdsys as monitoring target to our monit configuration file.

* Brainstormed a way to incorporate emma into OONI.
  https://gitlab.torproject.org/tpo/anti-censorship/emma/-/issues/5