[tor-project] Anti-censorship team meeting notes, 2024-11-21

Hey everyone!

Here are our meeting logs:
http://meetbot.debian.net/tor-meeting/2024/tor-meeting.2024-11-21-16.00.html

And our meeting pad:

Anti-censorship work meeting pad

···

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Anti-censorship
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Next meeting: Thursday, November 28 16:00 UTC
Facilitator: onyinyang
^^^(See Facilitator Queue at tail)

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

This week's Facilitator: shelikhoo

== Goal of this meeting ==

Weekly check-in about the status of anti-censorship work at Tor.
Coordinate collaboration between people/teams on anti-censorship at the Tor Project and Tor community.

== Links to Useful documents ==
* Our anti-censorship roadmap:
* Roadmap:Development · Boards · Anti-censorship · GitLab
* The anti-censorship team's wiki page:
* Home · Wiki · The Tor Project / Anti-censorship / Team · GitLab
* Past meeting notes can be found at:
* The tor-project Archives
* Tickets that need reviews: from projects, we are working on:
* All needs review tickets:
* Merge requests · Anti-censorship · GitLab
* Project 158 <-- meskio working on it
* Issues · Anti-censorship · GitLab

== Announcements ==

== Discussion ==

(old)
* Snowflake blocking in Russia November 2024
* Snowflake partially blocked in Russia 2024-11 (#40407) · Issues · The Tor Project / Anti-censorship / Pluggable Transports / Snowflake · GitLab
* No apparent difference in DTLS handshakes between proxies that continue working and proxies that stop working.
* Reports say that some proxies stop working, but only after transferring some traffic.
* Hard to test because we can't easily control the proxy. It would be a good idea to set up a small test deployment to afford us more experimental control.
* cohosh will work on that.
* Traffic analysis fingerprinting? An old padding patch: https://github.com/net4people/bbs/issues/255#issuecomment-1566227484
* on monday shelikhoo will start the move to the new broker
* WebTunnel Server utility command interface
* for certificate pinning we need to generate a hash of the certificate chain
* there is no standard tooling for that, we need to extend webtunnel to do that
* lets add a -gen-cert-fp flag
(New Nov 21)
* Snowflake blocking in Russia November 2024
* Restored copy-paste signaling (manual without broker) to be able to control the proxy connection.
* Add a copy paste rendezvous method for client (a4a574a4) · Commits · Cecylia Bocovich / Snowflake · GitLab
* Still blocked with a new proxy: therefore likely some kind of protocol fingerprinting, not proxy enumeration.
* Snowflake partially blocked in Russia 2024-11 (#40407) · Issues · The Tor Project / Anti-censorship / Pluggable Transports / Snowflake · GitLab
* Still blocked with client-side padding patch as well.
* Snowflake partially blocked in Russia 2024-11 (#40407) · Issues · The Tor Project / Anti-censorship / Pluggable Transports / Snowflake · GitLab
* theodorsm's covertDTLS fork Files · covert-dtls-test · theodorsm / Snowflake · GitLab
* Snowflake broker transition
* Next monday 2024-11-25 there will be a DNS switch from the current broker to the new broker primary.
* Request to update domain snowflake-broker.torproject.net with correct CAA record (#41878) · Issues · The Tor Project / TPA / TPA team · GitLab
* expired cdn77 alerts
* [FIRING:2] X509CertNearExpired -- blackbox - anti-censorship-alerts - lists.torproject.org

== Actions ==

== Interesting links ==

 \* https://github.com/doxx/darkflare
     \* TCP over CDN\. using cloudflare to tunnel traffic, the client does HTTP requests\.
 \* https://www.youtube.com/watch?v=rZYfrj2iqYE&list=PLbRoZ5Rrl5ldQ2K_dpmPKHEyRgyf5JSxd&index=148
     \* Snowflake conference presentation from Usenix Security 2024

== Reading group ==

 \* We will discuss &quot;&quot; on
     \*
     \* 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.

cecylia (cohosh): 2024-11-21
Last week:
- simplified the bridge_blocked function in lox (lox!277)
- improved clean up function and tests (lox!281)
- grant stuff
- iptproxy rewrite now released
- fixup for snowflake transport in lyrebird
- lox reviews
- tried some Snowflake experiments from the vantage point in Russia (snowflake#40407)
This week:
- keep looking at snowflake blocking in Russia
- take care of review backlog
- finish snowflake dependency upgrades that were causing problems
- take a look at snowflake web and webext translations and best practices
- make changes to Lox encrypted bridge table
- Draft: Simplify BridgeLine struct and make it variable length (!147) · Merge requests · The Tor Project / Anti-censorship / lox · GitLab
Needs help with:

dcf: 2024-11-21
Last week:
- released goptlib v1.6.0 goptlib v1.6.0 - anti-censorship-team - lists.torproject.org
Next week:
- comment on updates to unreliable snowflake transport Draft: Unreliable+unordered WebRTC data channel transport for Snowflake rev2 (!315) · Merge requests · The Tor Project / Anti-censorship / Pluggable Transports / Snowflake · GitLab
- open issue to have snowflake-client log whenever KCPInErrors is nonzero Deploy snowflake-server for QueuePacketConn buffer reuse fix (#40260) (#40262) · Issues · The Tor Project / Anti-censorship / Pluggable Transports / Snowflake · GitLab
- parent: Improve bug discovery process (#40267) · Issues · The Tor Project / Anti-censorship / Pluggable Transports / Snowflake · GitLab
- open issue to disable /debug endpoint on snowflake broker
Help with:

meskio: 2024-11-21
Last week:
- investigate OnionSproutsBot freeze (onionsproutsbot#68)
- distribute windows7 TorBrowser installers in OnionSproutsBot (onionsproutsbot#64)
- fix OnionSproutsBot locale deployment so all locales appear (onionsproutsbot#60)
- multiple grant writting work (reviews, risks assesments, ...)
- WIP on snowflake proxy package for debian (snowflake#40414)
Next week:
- update snowflake proxy debian package (snowflake#40414)

Shelikhoo: 2024-11-21
Last Week:
- [Pending] snowflake broker update/reinstall(cont.):

- [Awaiting Review] Unreliable+unordered WebRTC data channel transport for Snowflake rev2 (cont.)( Draft: Unreliable+unordered WebRTC data channel transport for Snowflake rev2 (!315) · Merge requests · The Tor Project / Anti-censorship / Pluggable Transports / Snowflake · GitLab ) improvements
- [Awaiting Input] Review CI: fix `latest` container image tag. CI: fix `latest` container image tag. (!408) · Merge requests · The Tor Project / Anti-censorship / Pluggable Transports / Snowflake · GitLab
- Request to update domain snowflake-broker.torproject.net with correct CAA record (Request to update domain snowflake-broker.torproject.net with correct CAA record (#41878) · Issues · The Tor Project / TPA / TPA team · GitLab)
- Rapid response fund for webtunnel dynamic bridges ( Sign in · GitLab )
- Choosing next provider target(s) for Rapid Response Funded Dynamic Bridges ( https://gitlab.torproject.org/tpo/community/relays/-/issues/106 )
- Merge request reviews
Next Week/TODO:
- Merge request reviews
- Work on finishing snowflake container release(and fix the comments)
- Vantage point deployment in Iran
- Snowflake broker deployment

onyinyang: 2024-11-21
Last week(s):
- working on refactor of Lox (library) protocols to improve issuing efficiency as described in: https://eprint.iacr.org/2024/1552.pdf
- WIP MR: Draft: Implement uCMZ for Lox credentials (!284) · Merge requests · The Tor Project / Anti-censorship / lox · GitLab
- Adjusted dependencies to line up with non-wasm browser integration for: Consider dropping Lox's WASM (#43096) · Issues · The Tor Project / Applications / Tor Browser · GitLab):
- Browser integration changes (!283) · Merge requests · The Tor Project / Anti-censorship / lox · GitLab
- Updating renovate bot to ignore these dependencies (and maybe others)
- Fixed up wasm changes in Improve testing branch for Lox distributor/wasm interactions (!271) · Merge requests · The Tor Project / Anti-censorship / lox · GitLab
Next week:
- Fix up Troll-patrol MR
- Deploy test distributor
- Continue work on improving issuer efficiency in Lox protocols
- update lox protocols to return duplicate responses for an already seen request
- Work on outstanding milestone issues:
in particular: Increase the acceptable time for bridgeline failure (#69) · Issues · The Tor Project / Anti-censorship / lox · GitLab
- key rotation automation

     Later:
     pending decision on abandoning lox wasm in favour of some kind of FFI? https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/43096):
         \- add pref to handle timing for pubkey checks in Tor browser
         \- add trusted invitation logic to tor browser integration:

- improve metrics collection/think about how to show Lox is working/valuable
- sketch out Lox blog post/usage notes for forum

 \(long term things were discussed at the meeting\!\):
     \- brainstorming grouping strategies for Lox buckets \(of bridges\) and gathering context on how types of bridges are distributed/use in practice
         Question: What makes a bridge usable for a given user, and how can we encode that to best ensure we&#39;re getting the most appropriate resources to people?
             1\. Are there some obvious grouping strategies that we can already consider?
                 e\.g\., by PT, by bandwidth \(lower bandwidth bridges sacrificed to open\-invitation buckets?\), by locale \(to be matched with a requesting user&#39;s geoip or something?\)
             2\. Does it make sense to group 3 bridges/bucket, so trusted users have access to 3 bridges \(and untrusted users have access to 1\)? More? Less?

theodorsm: 2024-10-24
Last weeks:
- Adjusting to post-student life
- Testing out beta releases of pion dtls and webrtc
Next weeks:
- Update Snowflake to use latest pion upstream releases
- Test Snowflake fork with covert-dtls
- Condensing thesis into paper
Help with:
- Feedback on thesis

Facilitator Queue:
onyinyang meskio shelikhoo
1. First available staff in the Facilitator Queue will be the facilitator for the meeting
2. After facilitating the meeting, the facilitator will be moved to the tail of the queue