Hi everyone,

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

Snowflake --------- * Improved throughput bottlenecks in Snowflake.

https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowf...

* Updated webrtc version in Snowflake.

https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowf...

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/...

* 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