Hey everyone!

Here are our meeting logs:

http://meetbot.debian.net/tor-meeting/2022/tor-meeting.2022-02-24-15.59.html

And our meeting pad:

Anti-censorship work meeting pad --------------------------------

Next meeting: Thursday February 24th 16:00 UTC

Weekly meetings, every Thursday at 16:00 UTC, in #tor-meeting at OFTC (channel is logged while meetings are in progress)

== Goal of this meeting ==

Weekly checkin about the status of anti-censorship work at Tor. Coordinate collaboration between people/teams on anti-censorship at Tor.

== Links to Useful documents ==

Our anti-censorship roadmap:

Roadmap: https://gitlab.torproject.org/groups/tpo/anti-censorship/-/boards

The anti-censorship team's wiki page:

https://gitlab.torproject.org/tpo/anti-censorship/team/-/wikis/home

Past meeting notes can be found at:

https://lists.torproject.org/pipermail/tor-project/

Tickets that need reviews: from sponsors we are working on:

All needs review tickets: https://gitlab.torproject.org/groups/tpo/anti-censorship/-/merge_requests?sc...

Sponsor 30

https://gitlab.torproject.org/groups/tpo/-/milestones/4

https://gitlab.torproject.org/groups/tpo/-/milestones/7

https://gitlab.torproject.org/groups/tpo/-/milestones/5

https://gitlab.torproject.org/groups/tpo/-/milestones/6

Sponsor 28

must-do tickets: https://gitlab.torproject.org/groups/tpo/-/milestones/10

possible tickets: https://gitlab.torproject.org/groups/tpo/-/issues?scope=all&utf8=%E2%9C%...

== Announcements ==

meskio plans to deploy rdsys+bridgedb next Monday, 2022-02-28.

many bridges will change distribution mechanism

== Discussion ==

obfs4 fail to connect issue

https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/40804

upstream maintainer recommends getting servers to upgrade

our own testing shows that new client -> new server solves the problem

no reply yet to the query sent to Aaron Johnson following last week's conversation

obfs4proxy is on its way to Debian testing, as soon as it hits testing we should ask acute to upload it to backports, to make it easier for server operators to upgrade

the package is expected to reach testing in <10 days

an upgrade of all obfs4 bridges will likely take time

start with the limited goal of upgrading all Tor Browser default bridges? https://gitlab.torproject.org/tpo/anti-censorship/team/-/wikis/Default-Bridg...

bridges currently don't report the version of the PTs they run, it would help track the progress of upgrading if they did report

https://gitlab.torproject.org/tpo/core/tor/-/issues/11101#note_2770219

Past discussion on using the PT STATUS message for version reporting:

https://lists.torproject.org/pipermail/tor-project/2021-October/003194.html

http://meetbot.debian.net/tor-meeting/2021/tor-meeting.2021-09-30-16.00.log....

uTLS in Snowflake Client Broker Communication

we have some concerns on the uTLS fingerprints being old and "easier" to censor

psiphon devs see uTLS working right for them

is a client side change, we can update it quickly

we don't enable uTLS by default, but make it an option from the SOCKS interface, so we can enable it by changing the bridge line from the circumvention settings

== Actions ==

== Interesting links ==

https://archive.org/details/ptim2021 Pluggable Transports Implementers Meeting 2021 videos

== Reading group ==

We will discuss "Throttling Twitter: an emerging censorship technique in Russia" on 10 March

https://dl.acm.org/doi/pdf/10.1145/3487552.3487858

https://censorbib.nymity.ch/#Xue2021a

Questions to ask and goals to have:

What aspects of the paper are questionable?

Are there immediate actions we can take based on this work?

Are there long-term actions we can take based on this work?

Is there future work that we want to call out, in hopes that others will pick it up?

== Updates ==

Name: This week: - What you worked on this week. Next week: - What you are planning to work on next week. Help with:

- Something you need help with.

anadahz: 2022-01-27

Last week:

- Increase timeout check cycles for default-bridge-felix-1 and default-bridge-felix-2 as they have been generating too many alerts: https://gitlab.torproject.org/tpo/anti-censorship/monit-configuration/-/merg...

cecylia (cohosh): last updated 2022-02-17 Last week: - tried out snowflake experiments in shadow's preload mode - https://github.com/shadow/shadow/issues/1549 - deployed snowflake server fixes - reached out to default bridge operators - finished s28 prep and documentation - wrote some follow up code for Snowflake event channel - https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowf... This week: - mostly afk Needs help with:

dcf: 2022-02-24

Last week:

- further helped debug obfs4proxy-0.0.12 connection failures https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/40804

- investigated a snowflake bridge outage and restarted the server

Next week:

- post summary of 2022-02-18 snowflake bridge outage

Help with:

agix: 2021-02-10

Last week:

- Continued work on gettor-twitter

Next week:

- Hopefully finish the task

Help with:

-

arlolra: 2022-01-20

Last week:

- [added 2022-01-20 by dcf] ALPN support for pion DTLS https://github.com/pion/dtls/pull/415

Next week:

- Figure out where in pion/webrtc ALPN should be configured and used

- Maybe add Chacha20Poly1305 to pion/dtls

https://github.com/pion/dtls#planned-features

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

Help with:

-

maxb: 2021-09-23

Last week:

- Worked on https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowf... re: utls for broker negotiation

- Had conversation with someone about upstream utls http round tripper https://github.com/refraction-networking/utls/pull/74

- Too busy with work :/

Next week:

- _Really_ want to get a PR for utls round tripper

meskio: 2022-02-24

Last week:

- validate opendkim headers in bridgedb (bridgedb!36)

- review concurrency problems in rdsys (rdsys#90)

- fix rdsys bridge status site, it was not reporting if they are working for non-vanilla bridges (rdsys#88)

- handle bridgedb reconnections (bridgedb!34)

- make easier to develop bridgedb with a fake rdsys (bridgedb#40034)

- coordinate the deployment of rdsys + bridgedb

Next week:

- deploy rdsys + bridgedb in production (rdsys#12)

- use rdsys bridges in circumvention settings (bridgedb#40045)

Shelikhoo: 2022-02-24 Last Week: - [Merge Request Awaiting] Add SOCKS5 forward proxy support to snowflake (snowflake!64) - [Merge Request Done] Add verbosity switch to suppress diagnostic output (snowflake#40079, snowflake!74) - [Merge Request] uTLS for broker negotiation

- [Discussion] Implement metrics to measure snowflake churn (snowflake#34075)

- [Discussion] Proposal: Support for Dynamic IP obfs4 bridges with unattended proxy information update (aka "Subscription")

- [Discussion] Proposal: Push Notification Based Signaling Channel

- [Discussion] Proposal: Centralized Probe Result Collector (anti-censorship/team#54)

- [Discussion] HTTPT & Websocket (https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/httpt...)

- [Investigate] Is there a better moat/snowflake SNI than cdn.sstatic.net? (snowflake#40068)

- [Investigate] Multi-instance Load Balanced Tor - Snowflake Deployment

- [Investigate] China "Anti-Fraud" Webpage Redirection Censorship (censorship-analysis#40026)

- [Investigate] S96 Bridge Performance

Next Week: - [Discussion] Implement metrics to measure snowflake churn (snowflake#34075) - [Discussion] Proposal: Push Notification Based Signaling Channel - [Coding] Proposal: Centralized Probe Result Collector (anti-censorship/team#54)

HackerNCoder: 2021-12-16 This week: Last/done: Setup web mirror on tor.encryptionin.space Next: Get (new VPs with) new IP and setup new web mirror on new domain

hanneloresx: 2021-3-4

Last week:

- Submitted MR for bridgestrap issue #14

Next week:

- Finish bridgestrap #14

- Find new issue to work on

Help with:

-