- tor-dev - lists.torproject.org

Network Team - Deprecating C-tor Patches
by David Goulet 09 May '22

09 May '22

Greetings everyone! The network team has come up with a policy about C-tor patches in order to help and facilitate our transition to arti. The TL;DR is essentially that we will be reducing considerably the amount of patches (fixes and features) we take in for C-tor[0], most importantly on the client side, in order to alleviate the maintaining work of C-tor in favor of arti development. Please, read the following explaining why and what is changing regarding C-tor patches and development work: https://gitlab.torproject.org/tpo/core/team/-/wikis/NetworkTeam/Deprecating… Don't hesitate to ask questions! Cheers! The Network Team [0] https://gitlab.torproject.org/tpo/core/tor -- G1nLmyQttfczv2rHXvhgktvgPessxMCOKSOe/VwGY/Y=

1 0

How to get source port from conn object
by redriderbbgun11 01 May '22

01 May '22

Hey all, I want to get to know the TOR codebase so I can contribute to the project. To do this I have been doing a few projects of just doing sort of basic tasks to get an idea for how it all works together. One thing that is giving me a bit of trouble but seems like it should be simple is finding the source port for a conn object. How do I find this and moreover how do I find the actual socket behind a given connection? In connection_t I see tor_socket_t but it seems to just be an int value. Thanks

1 0

Discussion about Tor Directory Authority Consensus Code
by Zhongtang Luo 26 Apr '22

26 Apr '22

Hi all! I am a PhD student currently doing some experiments on Tor. My advisor and I was wondering if we can talk to somebody who takes care of the Tor Directory Authority code, since there is a conceptual issue we wish to communicate with them. Can somebody direct us to the appropriate person? Many thanks. Yours, Zhongtang Luo

2 1

We built a new Tor-based team chat prototype. Wanna try it?
by Holmes Wilson 15 Apr '22

15 Apr '22

Hi everyone, My collaborators and I have been working for the past couple years on building a Tor-based team chat app which we're calling Quiet*, and I'm curious if anyone here would like to try it out! If you would, please reply! :) I am especially interested in feedback from Tor project participants and people who are sometimes in the position of advising organizations on their security needs, but everyone on this list is welcome! What I'll try to do is find a time that would work for all of us so we can try it together in a true test of its team chat possibilities, though if that doesn't work I'm happy to do one on one meetings too. Quiet is still lacking pretty much every feature imaginable except adding team members and sending and receiving messages. And mobile apps aren't ready yet. And it hasn't been audited so it shouldn't be used for anything important at all. And so on. But if you've tried any attempts at p2p group chat before, this one will strike you as surprisingly reliable thanks in no small part to the reliability of Tor. So it's pretty cool to see it in action and it's a fun new way to use Tor. Again, I'm not looking for any real end users at this stage—we're just not ready for that yet. But we've invested a lot in usability and reliability and we're making a really serious go of it. This isn't vaporware and I think it'll be worth your time to check it out! :) Perhaps the coolest part about our approach is that its usefulness goes way beyond chat apps. The approach we've taken is adequate for building private, F/OSS alternatives to a large class of crucial applications that currently lack strong privacy and security properties, such as Trello, Asana, Basecamp, Google Docs and Sheets, Figma, Discourse, Airtable, team password managers, and more. Specifically, you can use it to build any application where a bounded group of people share some common workspace, as long as the data would fit on a typical consumer device. And perhaps from that foothold we can figure out ways to extend the model to be adequate for building large unbounded networks like Signal, Twitter, and Facebook in a decentralized way, though that's a much harder class of problem. (I gave this talk <https://archive.org/details/hopeconf2020/20200802_1600_Zbay%2C_Fighting_FAA…> a couple years back at HOPE 2020 about these ideas which is a pretty good overview of the motivations behind the project, and and I'll be speaking again at HOPE 2022 this summer about where we're at now, so it would be great to meet up there if anyone else will be there!) I've included some more notes below on how it works for those who are curious. But if you're curious please write me back so I can give you a demo :) Holmes # How it works Quiet is like a combination of Slack and Ricochet. Ricochet did not depend on any servers except for the Tor network itself, and sent messages directly over onion services, but it was only for 1:1 messaging. Like Ricochet, Quiet doesn't require any servers except for the Tor network itself, but it uses some p2p libraries that have emerged over the past few years to enable group chat where—like Slack and Discord—all clients tend to display the same message history, even clients that were offline when messages were sent. Specifically, Quiet uses OrbitDB, a CRDT. CRDTs are sort of like Git, where they enable syncing between decentralized peers such that all peers eventually converge on the same state. OrbitDB is built on IPFS, so unlike a lot of CRDTs (like Automerge) it comes with some built-in ability to move data around between peers. IPFS is pretty flexible and we set it up so that each team has its own totally isolated IPFS network, and all the IPFS clients connect to each other over Tor. There's no big, global, leaky p2p network, and no blockchain or anything like that. You have a group of friends, and you just talk to each others onions. That's it. To invite a new user, an authorized user shares an onion service link to a "registrar" onion service running on their machine, and they add that new user's key information to a user table, and give the user a certificate they can use to connect to other peers. A single community owner uses certificates to grant unique usernames. Mobile apps use the same approach, though we'll need a centralized service for notifications on iOS until someone changes the way Apple Apples, and we haven't built that yet. There are a lot of other important pieces of the design we haven't tackled yet too, such as timed message deletion, removing users, use of onion auth for incoming connections, optimizations for very large communities, and so on. But it's all fairly tractable, if a bit slow going. (I'm also really interested if this description is clear and would love your feedback and questions!)

1 0

Interoperation with libp2p
by Mike Mestnik 07 Apr '22

07 Apr '22

https://gitlab.torproject.org/tpo/core/torspec/-/issues/64

5 5

[dappy] Willing to chat with tor devs, about name system issues/solutions
by Raphaël Fabre 27 Mar '22

27 Mar '22

Hello I'm Raphaël (fr) I just joined the tor dev mailing list. I would like to chat with tor developers, particularly if they have worked, or are interested in the issues regarding a name system for tor. I'm the lead developer of dappy https://dappy.tech , we'll launch in 2022 and I do think we have interesting properties, for the public web as well as for tor and privacy-focused web projects. We are the only name system in the world that does co-resolution, that's the way we found to maintain a consistent name system, and also avoid censorship and phishing. Our system has the following properties: - blockchain-based name system: it simply means that mapping is globally consistent, name management is distributed in the sense that a blockchain handles it, the resolver just connect to this blockchain. - Systematic co-resolution (not rotation): lookup request are always addressed to a network of independant agents: there are many instead of a single one. And then there is consensus at browser level. This prevents 90% of attacks or attempt of censorship/phishing. - Anonymous registrations - Load-balancing of names: you can attach 20 IP addresses to your name, dappy browser will try each one of them until it gets a response. - 100% encrypted/https Censorship cannot happen, neither at the storage location (blockchain) or on-the-fly at resolution time (co-resolution) We will launch in 2022 and would be thrilled to exchange with some developers or engineers. This document has lead me to the path of the tor-dev mailing list https://gitlab.torproject.org/legacy/trac/-/wikis/doc/OnionServiceNamingSys… Happy to chat Merry Christmas Raphaël Fabre Building a ultra-secure blockchain-based name system and browser https://dappy.tech

2 2

Time interval for changing Introduction Points in Tor Hidden Services
by Piyush Kumar Sharma 23 Mar '22

23 Mar '22

Hi all, I have been investigating the Tor hidden services for some research work. I am finding it hard to obtain information about how often do Introduction Points of hidden service change. More specifically, I am looking for answers to the following questions: 1.) If the tor relays selected as Introduction Points for a hidden service go down (e.g., due to DoS), then in what time duration does the hidden service select new Introduction Points automatically? 2.) Even when the Introduction Points are not down, is there a duration after which they are automatically changed by the hidden service? If so, what is this duration? I have already tried to find this information in the Tor-spec about onion v3 services. But could not find answers to these specific questions. Thus, it would be really helpful if someone can answer these questions or point to some resources where this information can be obtained. Thanks

2 3

Gosling onion-to-onion specifications
by Richard Pospesel 19 Mar '22

19 Mar '22

Hi tor-dev, As part of my work with Blueprint for Free Speech, I recently gave a short presentation during the 2021 state-of-the-onion where we announced Gosling ( see https://youtu.be/mNhIjtXuVzk?t=8155 ). If you missed the talk, the tldr; is that we're developing a specification and reference implementation library for building (onion service based) anonymous+private+secure peer-to-peer applications. Essentially, we're taking what we've learned about onion-to-onion authentication from Ricochet-Refresh, extracting and improving the relevant pieces, and packaging it all in a library that developers can use to build their own anonymous+private+secure peer-to-peer applications. Our hope is that future developers will not need to be tor experts to build these types of applications. Today ,I'm happy to announce that we just made the the gosling repo on Github public! - https://github.com/blueprint-freespeech/gosling Things are little bare-bones at the moment, but the most relevant piece right now is the protocol specification here: - https://github.com/blueprint-freespeech/gosling/blob/main/docs/protocol.md You'll also find some initial prototyping work under the source directory (the pace of development should pick up come 2022). Please go take a look and feel free to respond here with any questions, concerns, criticisms, etc. Thanks! best, -Richard

1 1

txtorcon v22.0.0
by meejah 16 Mar '22

16 Mar '22

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 I'm pleased to announce txtorcon 22.0.0. This fixes some broken infrastructure. * Use GitHub Actions (not Travis) * Update method to upload coverage to coveralls You can download the release from PyPI or GitHub (or of course "pip install txtorcon"): https://pypi.python.org/pypi/txtorcon/22.0.0 https://github.com/meejah/txtorcon/releases/tag/v22.0.0 Releases are also available from the hidden service: http://fjblvrw2jrxnhtg67qpbzi45r7ofojaoo3orzykesly2j3c2m3htapid.onion/txtor… http://fjblvrw2jrxnhtg67qpbzi45r7ofojaoo3orzykesly2j3c2m3htapid.onion/txtor… You can verify the sha256sum of both by running the following 4 lines in a shell wherever you have the files downloaded: cat <<EOF | sha256sum --check 89a1b65e32a4b369d67e6c166387fbc468cc5d05227448d239a5e7e9718aa053 dist/txtorcon-22.0.0.tar.gz 824b5df1977bedabfc1c49c9523b8fa1b7cff11d6fee78015df1ce133685779c dist/txtorcon-22.0.0-py2.py3-none-any.whl EOF thanks, meejah -----BEGIN PGP SIGNATURE----- iQFFBAEBCgAvFiEEnVor1WiOy4id680/wmAoAxKAaacFAmIyVzMRHG1lZWphaEBt ZWVqYWguY2EACgkQwmAoAxKAaaeNYQf/XBYfAvqqvT/jU+z8EUwgj0EJbFusNAls 8W37RE8fRkxTCYBOnfmK2IlQouHLBVgjzS2H0ZGyAzczxZb/kfY7uRbAm7N63eMx rc7urZtDeHS4K7+cUPf03KlqYdKmbIGEezPVQSNRT1/UZ/kTB6CxMqteyXxfYkvY +pkfIvOJ49Yw6KuMt+iWKRNnfVsMNYX+gV6PNYBHoWGRTWxANReaXRSowe+5Cgus 4O51I3+1QH1slLIH77Dvpktmqka+Fbs3mDWm1ICzf4rB0z+aJRxt7xYjNnhaLCPQ 5xeY1IdmmJAxg/WouMQh1Kus8eEWgIhFLeigPN+ABwt2VziL1lL8XQ== =HKmX -----END PGP SIGNATURE-----

1 0

Proposal 338: Use an 8-byte handshake in NETINFO cells
by Nick Mathewson 14 Mar '22

14 Mar '22

``` Filename: 338-netinfo-y2038.md Title: Use an 8-byte timestamp in NETINFO cells Author: Nick Mathewson Created: 2022-03-14 Status: Open ``` # Introduction Currently Tor relays use a 4-byte timestamp (in seconds since the Unix epoch) in their NETINFO cells. Notoriously, such a timestamp will overflow on 19 January 2038. Let's get ahead of the problem and squash this issue now, by expanding the timestamp to 8 bytes. (8 bytes worth of seconds will be long enough to outlast the Earth's sun.) # Proposed change I propose adding a new link protocol version. (The next one in sequence, as of this writing, is version 6.) I propose that we change the text of tor-spec section 4.5 from: ``` TIME (Timestamp) [4 bytes] ``` to ``` TIME (Timestamp) [4 or 8 bytes *] ``` and specify that this field is 4 bytes wide on link protocols 1-5, but 8 bytes wide on link protocols 6 and beyond. # Rejected alternatives Our protocol specifies that parties MUST ignore extra data at the end of cells. Therefore we _could_ add additional data at the end of the NETINFO cell, and use that to store the high 4 bytes of the timestamp without having to increase the link protocol version number. I propose that we don't do that: it's ugly. As another alternative, we could declare that parties must interpret the timestamp such that its high 4 bytes place it as close as possible to their current time. I'm rejecting this kludge because it would give confusing results in the too-common case where clients have their clocks mis-set to Jan 1, 1970. # Impacts on our implementations Arti won't be able to implement this change until it supports connection padding (as required by link protocol 5), which is currently planned for the next Arti milestone (1.0.0, scheduled for this fall). If we think that that's a problem, or if we want to have support for implementations without connection padding in the future, we should reconsider this plan so that connection padding support is independent from 8-byte timestamps. # Other timestamps in Tor I've done a cursory search of our protocols to see if we have any other instances of the Y2038 problem. There is a 4-byte timestamp in `cert-spec`, but that one is an unsigned integer counting _hours_ since the Unix epoch, which will keep it from wrapping around till 478756 C.E. (The rollover date of "10136 CE" reported in `cert-spec` is wrong, and seems to be based on the misapprehension that the counter is in *minutes*.) The v2 onion service protocol has 4-byte timestamps, but it is thoroughly deprecated and unsupported. I couldn't find any other 4-byte timestamps, but that is no guarantee: others should look for them too.

2 3