tor-relays May 2023

tor-relays@lists.torproject.org

15 participants
14 discussions

recommended way to run 0.4.7 on armhf?
by ilf 25 Nov '23

25 Nov '23

What's the recommended way to run 0.4.7 on armhf? > The package repository [deb.torproject.org] does not offer 32-bit ARM > architecture (armhf) images (yet). https://support.torproject.org/apt/tor-deb-repo/ Debian has 0.4.7 in bullseye-backports. But Raspbian doesn't have bullseye-backports: http://raspbian.raspberrypi.org/raspbian/dists/ -- ilf If you upload your address book to "the cloud", I don't want to be in it.

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(EVENT) Tor Relay Operator Meetup - June 24, 2023 @ 18.00 UTC
by gus 10 Aug '23

10 Aug '23

Hello, The next Tor Relay Operator Meetup will happen on June 24, 2023, at 18.00 UTC. We're working on the agenda here: https://pad.riseup.net/p/tor-relay-op-meetup-june-keep onionsite: http://kfahv6wfkbezjyg4r6mlhpmieydbebr5vkok5r34ya464gqz6c44bnyd.onion/p/tor… Feel free to add other topics to the agenda. WHERE Room link: https://tor.meet.coop/gus-og0-x74-dzn Registration No need for a registration or anything else, just use the room-link above. We will open the room 10 minutes before so you can test your mic setup. Please share with your friends, social media and other mailing lists! cheers, Gus -- The Tor Project Community Team Lead

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Help Turkmens to bypass Internet censorship: run an obfs4 bridge!
by gus 02 Aug '23

02 Aug '23

Dear Relay operators community, The parliamentary elections in Turkmenistan are coming up very soon on March 26th[1], and the Turkmen government has tightened internet censorship and restrictions even more. In the last few months, the Anti-censorship community has learned that different pluggable transports, like Snowflake, and entire IP ranges, have been blocked in the country. Therefore, running a bridge on popular hosting providers like Hetzner, Digital Ocean, Linode, and AWS won't help as these providers' IP ranges are completely blocked in Turkmenistan. Recently, we learned from the Anti-censorship community[2] and via Tor user support channels that Tor bridges running on residential connections were working fine. Although they were blocked after some days or a week, these bridges received a lot of users and were very important to keep Turkmens connected. How to help Turkmens to access the Internet =========================================== You can help Turkmens to access the free and open internet by running an obfs4 Tor bridge! But here's the trick: you need to run it on a residential connection -- you won't need a static IPv4 --, and it would ideally be run on more robust hardware than just a Raspberry Pi (although that can help, we have found they can get overloaded). You can set up an obfs4 bridge by following our official guide: https://community.torproject.org/relay/setup/bridge/ After you setup a new bridge, you can share your bridge line with the Tor support team at frontdesk(a)torproject.org, and we will share it with users. A complete bridge line is composed of: IP:OBFS4_PORT FINGERPRINT cert=obfs4-certificate iat-mode=0 Check this documentation to learn how to share your bridge line: https://community.torproject.org/relay/setup/bridge/post-install/ Just sharing your bridge fingerprint is not the best, but it's fine. You can read more about censorship against Tor in Turkmenistan here: - https://gitlab.torproject.org/tpo/anti-censorship/censorship-analysis/-/iss… - Snowflake blocked: https://gitlab.torproject.org/tpo/anti-censorship/censorship-analysis/-/iss… Thank you for your support in helping to keep the internet free and open for everyone. Gus [1] https://en.wikipedia.org/wiki/2023_Turkmen_parliamentary_election [2] https://ntc.party/c/internet-censorship-all-around-the-world/turkmenistan/17 https://github.com/net4people/bbs/issues/80 -- The Tor Project Community Team Lead

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Security implications of disabling onion key rotation?
by David Fifield 05 Jul '23

05 Jul '23

Linus Nordberg and I have had a paper accepted to FOCI 2023 on the special pluggable transports configuration used on the Snowflake bridges. That design was first hashed out on this mailing list last year. https://forum.torproject.net/t/tor-relays-how-to-reduce-tor-cpu-load-on-a-s… https://github.com/net4people/bbs/issues/103 https://gitlab.torproject.org/tpo/anti-censorship/team/-/wikis/Survival%20G… There is a draft of the paper here: https://www.bamsoftware.com/papers/pt-bridge-hiperf/pt-bridge-hiperf.202303… https://www.bamsoftware.com/papers/pt-bridge-hiperf/pt-bridge-hiperf.202303… A question that more than one reviewer asked is, what are the security implications of disabling onion key rotation as we do? (Section 3.2 in the draft.) It's a good question and one we'd like to address in the final draft. What are the risks of not rotating onion keys? My understanding is that rotation is meant to enhance forward security; i.e., limit how far back in time past recorded connections can be attacked in the case of key compromise. https://spec.torproject.org/tor-design Section 4 says: Short-term keys are rotated periodically and independently, to limit the impact of key compromise. Do the considerations differ when using ntor keys versus TAP keys?

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[Important] A call for more long running bridges, especially with OBFS IAT-Mode set to 1 or 2.
by George Hartley 16 Jun '23

16 Jun '23

Hello dear relay and bridge hosts, recently a paper was published, describing a traffic confirmation attack called DeepCorr, which works against Tor users and as such, also hidden services. The attack allegedly had success rates of up to 96% percent. It is being worked on and listed here as a separate ticket: https://forum.torproject.net/t/tor-dev-critical-deepcorr-traffic-confirmati… Until mitigations have been merged into the Tor codebase, I kindly ask you, the driving force behind the network, to set up more bridges with "iat-mode" enabled and set to "1" or "2" - the paper stated that it was significantly harder to launch successful attacks against clients using OBFS4 bridges with timing obfuscation enabled, which is what "iat-mode" really is. In a nutshell, the measure of IAT is the average (or the arithmetic mean) between network packets arriving at a host over a period of time, of the times between packets arriving at a host over a period of time, which you can also call latency. For security reasons such as defeating DPI and similar network analysis techniques, OBFS4, while at the same time encrypting and making your traffic look like regular TLS traffic, it also offers to try and obfuscate the IAT and packet size by inserting random padding bytes. For you guys or girls with programming skills or the ability to read and understand code, here is the responsible code: https://github.com/Yawning/obfs4/blob/40245c4a1cf221395c59d1f4bf27412704535… I vote for a fair 50 / 50 distribution of bridges with "iat-mode=1" and "iat-mode=2", even though while IAT mode 2, also called the "paranoid" mode by the author of the code above, may be more effective. Dear clients, you can already enable timing-obfuscation in one way, by editing your bridge-line and setting iat-mode from "0" to either "1" or "2" - please be aware that this will only enable timing-obfuscation in one way, the bridge needs to support it too to get packet timing obfuscated in both ways. Dear bridge operators, all it takes is a simple tor configuration file change: ServerTransportOptions obfs4 iat-mode=1 or ServerTransportOptions obfs4 iat-mode=2 Your bridge key will very likely stay the same, although I do not have the infrastructure to try this out right now. It is and has been very hard to find reliable OBFS4 bridges which also support timing obfuscation, for over a year now - please consider changing your bridge configuration in order to possibly help clients and hidden services evade timing related attacks such as DeepCorr. Yours truly, George Hartley

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Tor Relay Operator Poll (closes on 2023-05-30)
by nusenu 27 May '23

27 May '23

Hi, want to help shape the future of the Tor network? Here is a poll for you: https://cryptpad.fr/form/#/2/form/view/VE-b3bd-IS1P17Povh0ryIHYhqGqEiA7sJMR… It is open until 2023-05-30. Only operators that did run relays/bridges before 2023-04-01 (and are still running) may participate. An AROI or a relay fingerprint (or hashed bridge fingerprint) is required to participate. This poll happens in the context of working on a network health proposal. The goal of this poll is * to gather input from non-malicious relay operators * to help make pragmatical design decisions for an upcoming network health proposal * to ensure it remains practical to implement for relay operators * to get a feeling on whether it has a chance to see actual real world adoption * to get a feeling on whether relay operators would participate in a web of trust * to get a feeling on what type of rules relay operators would find acceptable In the light of malicious entities this poll has been send to large relay operators a few days ago so they can claim their submission first. Their feedback was also used to improve and extend the poll, if you submitted it already once you can submit it again but ensure to submit the same random string at the end as you did the first time so they can be linked. kind regards, nusenu -- https://nusenu.github.io

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ContactInfo semantics
by nusenu 26 May '23

26 May '23

This is probably of interest to many relay operators: https://gitlab.torproject.org/tpo/community/relays/-/issues/71 > Write proposal to restrict contact information field to email address (and make it mandatory) https://gitlab.torproject.org/tpo/core/arti/-/issues/870 > Restrict contact information field in arti to just allow an email address kind regards, nusenu -- https://nusenu.github.io

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Configuring key expiration warning messages?
by telekobold 22 May '23

22 May '23

Hi everyone, I'm using OfflineMasterKey 1 for my Tor bridge, hosting and renewing the long-term identity key on a Tails USB stick. I observed that Tor starts printing warning messages to /var/log/tor/notices.log 24 hours before the intermediate key expires. My question is if there is a flag that could be set in the torrc file to start printing these warning message more than 24 hours before the expiration time, possibly even with outputting the exact expiration time? If there isn't such an option, does anyone happen to have a script ready for this (before I start trying to implement something like this myself)? Kind regards telekobold

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Tor Relay Operator Meetup - April 15th, 2023 at 19 UTC
by gus 22 May '23

22 May '23

Hello, The next Tor Relay Operator Meetup will happen on April 15th, 2023, at 19 UTC. We're still working on the agenda, feel free to add your topics and/or questions on the pad: https://pad.riseup.net/p/tor-relay-op-meetup-april-keep onionsite: http://kfahv6wfkbezjyg4r6mlhpmieydbebr5vkok5r34ya464gqz6c44bnyd.onion/p/tor… WHERE Room link: https://tor.meet.coop/gus-og0-x74-dzn Registration No need for a registration or anything else, just use the room-link above. We will open the room 10 minutes before so you can test your mic setup. Please share with your friends, social media and other mailing lists! Gus -- The Tor Project Community Team Lead

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mulitply ipv6 bridge lines for a single bridge
by Toralf Förster 21 May '23

21 May '23

Given that hosters of a VPS often gives a big /48, /56 or /64 ipv6 subnet to a VPS I do wonder if the BridgeLine for ipv6 could benefit from that? With ip6tables -t nat -I PREROUTING -p tcp -j DNAT --to-destination [obfs4 address] /usr/sbin/ip6tables-save > /etc/iptables/rules.v6 all incoming TCPv6 packets would be flow to the bridge address. This idea is implemented in [1]. BTW there I do change the factory default ipv6 address into a random one too. [1] https://github.com/toralf/tor-relays/blob/main/playbooks/roles/setup/tasks/… -- Toralf

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