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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

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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

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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-----

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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.

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Fine Tunneling For Tor Network | Tor Browser
by Alessandro Greco 09 Mar '22

09 Mar '22

Dear Tor-Dev, My name is Alessandro Greco and I am an Italian computer science student, I am finishing my studies and therefore I am working with my thesis and, as a topic, my supervisor and I have chosen the Tor network. The work done focuses entirely on the Tor Browser torrc configuration file, which is why I wrote Professor Steven Murdoch and he pointed me to this method in order to get in touch with the current Tor-Project developers. I state that I am not good in English and therefore I may be wrong or not give the right weight to the words. Going into the matter, I have developed an extension currently available only on Firefox reachable via the addresshttps://addons.mozilla.org/it/firefox/addon/tropea-project/. The initial goal was to simplify the tunneling phase, already editable through the Tor Browser torrc file, through commands such as ExitNode or ExcludeNode and much more. In order to simplify the use, I decided to create an extension and an "advanced" section, thus bringing back user-friendly graphic interfaces already well known to average users (the advanced section consists of a web page), which would allow modify the file to your liking without necessarily having to follow correct syntax and without having to go too far into the technical aspect of Tor Browser. Why? I decided to simplify the use of this configuration file because I believe that the path of "simplification" is the only (or in general one of the most important) way to be able to expand the catchment area by trying to accommodate more people who have the need for a network like Tor in order to be able to divert dictatorial censorship methods by governments. I want to give a practical example, let's consider the current situation between Russia and Ukraine. Although Putin belongs to Russia, it is also true that there is a large slice of Russian citizens who are intellectually suppressed every day given the limits of censorship by the Russian government and by other governments that limit the people in order to weaken Putin. Russia has currently blocked several social networks so that citizens can no longer share the atrocities that are happening, so much so that Anonymous has asked to publish photos and videos of what is happening through Google Maps or other applications that are currently not censored. In all this mess, I sincerely think that Tor can significantly affect the protection of truth and rights on the net. But it is also true that many people do not know how to use or modify these settings correctly or, more simply, they may not even know that they can change some settings. I strongly believe that a breakthrough in the world of Tor Networks is needed and so that citizens of every state in the world can have, without minimum IT requirements, the ability to fully use Tor Browser and consequently Tor. The thesis work is called Tropea-Project (Tropea is a type of onion from our area, if you want to do a search, look for Tropea Onion on Google) and it is completely free and open-source so that anyone can dare to add new features. The features currently available are the following: [Add-Remove] EntryNodes + StrictNodes [Add-Remove] ExitNodes + StrictNodes [Add-Remove] ExcludeNodes [Add-Remove] ExcludeExitNodes [Edit] GeoIPExcludeUnknow [Edit] Reset configuration [Torify App] Torify /*It depends on the application launched, [Working Application](https://github.com/NoNameoN-A/Tropea-Project/blob/main)*/ Please consider this project, at the moment I am struggling with the writing of the thesis so in a few weeks an extremely detailed guide on the whole programming aspect will be published so that I can help any student, programmer, hacker and anyone who wants to improve existing features or add new ones. I am very excited to write you this email and I hope you can consider this development of mine which focuses 100% of the forces so that the Tor project can help free as many people as possible from inhuman web slavery. I believe that online freedom is a humanitarian right on par with education and water, so I think it is appropriate to develop new features that simplify its use. If you have read this far I would ask you now to see the demonstration video that I have published so that you can see for yourself what it does and I hope you can understand how much I care. Now more than ever anyone needs Tor. * Technical notes on the extension * In order for it to be used correctly, you must first start a local script called tropea.js, which is located in the socket-tropea folder of the Repository. The extension code is in the tropea folder of the Repository. Since the exact path of the Tor Browser folder is required, due to the configuration of the torrc file, it would be ideal to install it when installing Tor Browser so as to further simplify the whole process so that they don't even have to run the local script as it might launch when Tor Browser starts. Repository:https://github.com/NoNameoN-A/Tropea-Project Demonstration video:https://peertube.uno/w/acz9VzntwYFicwgxk7i9by I wrote an informal article on my blog:https://greco-alessandro.netlify.app/articles/tropea-project-la-rete-tor-da-un-altro-punto-di-vista/ Thesis with technical documentation of the code: At the moment not available because I haven't finished writing it yet. Best Regards, Alessandro Greco. -- FSF Member (NoNameoN), Join the Free Software Foundation! (fsf.org) Browse my WebSite! (autistici.org/nonameon)

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Relay "Ping" Functionality
by Alexander Mages 19 Feb '22

19 Feb '22

Hello Tor-Dev, My name is Alex Mages, and I have been doing pluggable transport research with Eugene Vasserman (CC) at Kansas State University. Right now we're exploring latency-based attacks but are having trouble achieving a particular goal: a way to “ping” an arbitrary node in a client’s already-built (“live”) circuit. One-way timing is ideal but round trip time would suffice. We can glean this information during circuit construction, but what about a “live” circuit? Ideally, this would be a periodic thing Tor already keeps track of, but as an on-demand or as a byproduct/side-effect of a different function would also work. We have not been able to find a way to do this within the Tor (sub)protocol specs or the control port spec. Any ideas, suggestions, or criticisms would be greatly appreciated. Thanks, Alex Mages

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onionoo overload_general_timestamp (prop 328)
by nusenu 10 Feb '22

10 Feb '22

Hi, in onionoo all timestamps used to be in the format YYYY-MM-DD hh:mm:ss Proposal 328 has timestamps in this same format https://gitlab.torproject.org/tpo/core/torspec/-/blob/main/proposals/328-re… The newly added prop328 fields in oninoo appear to break with that convention https://metrics.torproject.org/onionoo.html#details_relay_overload_general_… Here is an example for an onionoo overload_general_timestamp which appears to be at millisecond granularity (the source has a granularity of an hour): 1636038000000 Was there a particular motivation for this format change and granularity? And what do you think about changing it to use the YYYY-MM-DD hh:mm:ss format for consistency and having a direct human readable format here as well? related: Karsten used to maintain onionoo protocol documentation/changelog and versions: https://metrics.torproject.org/onionoo.html#versions Is that and the 'version' field in onionoo no longer maintained? (since it didn't change with the new fields) kind regards, nusenu -- https://nusenu.github.io

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onbasca - the next-generation bandwidth scanner
by Georg Koppen 09 Feb '22

09 Feb '22

Hello everyone! As many of you know we have been working on a simple bandwidth scanner (sbws) over the last years to deal with the old and unmaintained Torflow code on our bandwidth authorities. We learned a lot during that process, especially after we started to replace Torflow with the new sbws code on bandwidth authorities (today sbws is powering a majority of them, yay!). We realized that we needed to improve the robustness and testability of the code significantly, in particular as we want to build exciting features like loadbalancing capability on top of it and decided it would be easier to do so in a new tool: welcome onbasca. Onbasca takes the best out of sbws and makes the code easier to test and more robust for future improvements by deploying a database management system where we previously dealt with JSON files only.[1] The code repository lives in our network-health group[2] and is open for contributions. Get in touch in case you are interested, everyone is welcome! Georg [1] For a more detailed overview over the bandwidth scanner history, design issues we encountered in sbws, and decisions we made, see: https://tpo.pages.torproject.net/network-health/onbasca/history.html. [2] https://gitlab.torproject.org/tpo/network-health/onbasca

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HAROI: Human Readable Authenticated Relay Operator Identifier
by nusenu 27 Dec '21

27 Dec '21

Hi, below is a partial proposal draft for human readable relay operator IDs that are authenticated by directory authorities. If there is any interest in implementing something like this I'll complete the draft and submit it via gitlab. kind regards, nusenu # HAROI: Human Readable Authenticated Relay Operator Identifier A HAROI is a DNS FQDN that can be chosen by a relay operator and linked to one or more relays in a verifiable way. The link is authenticated in the sense that it requires some control over the relay and the FQDN (on the DNS or webroot level). A relay can only be linked to a single HAROI. Relays publish their HAROI via their descriptor. Directory authorities verify the link and publish the verification result in their vote. ## Motivation Many tools in the tor ecosystem display at least some relay (operator) information (nickname, ContactInfo, ...), some examples are: - Tor Browser - Relay Search [1] - Onioncircuits by tails [2] - ExoneraTor [3] - allium [4] unfortunatelly there is no authenticated operator ID available, these tools could display, so they might display misleading information, something that has been exploited in the wild for impersonation attacks. There is a value in giving relay operators the possibility to declare an identifier that is globally unique, consistent and can not be easily spoofed by adversaries so they do not become easy victims of impersonation attacks. The tor ecosystem would benefit from an operator ID that can not be spoofed. This proposal is not replacing the relay ContactInfo. ## Design * A HAROI is optional and not mandatory. * A HAROI is verified by directory authorities in one of two ways, depending on the proof type. In the distant future where relays have no RSA1024 keys, Ed25519 proof types are added. * The used proof type can be selected by the relay operator. Successfully verified proofs are cached by directory authorities for 30 days. After 30 days proofs are verified again. Relay operators that want to make use of HAROI can participate without requiring a domain since many free services offer custom free subdomains (example: GitLab or GitHub pages). ## Proof Types Relay operators, that chose to set a HAROI, can select their preferred a proof type. ### uri-rsa This proof type can be verified by fetching the list of relay RSA SHA1 fingerprints from the FQDN via HTTPS using the well-known URI as defined in proposal 326 https://gitlab.torproject.org/tpo/core/torspec/-/blob/main/proposals/326-to… Example: if the FQDN is example.com, the url to fetch the list of fingerprints is: https://example.com/.well-known/tor-relay/rsa-fingerprint.txt The TLS certificate used on the webserver must be from a trusted CA and logged in a public certificate transparency log. For N relays using the same FQDN only a single HTTPS GET request is needed. ### dns-rsa This proof type can be verified by performing DNS lookups. To make use of this proof type the DNS zone MUST be DNSSEC signed. The DNS query is constructed by combining the relay's fingerprint and the FQDN: relay-fingerprint.<FQDN> example: relay-fingerprint.example.com value: “we-run-this-tor-relay” relay-fingerprint is the 40 character RSA SHA1 fingerprint of the tor relay. Each relay has its own DNS record, a single TXT record MUST be returned per relay only. content of the TXT record MUST match: "we-run-this-tor-relay” Each relay requires a single DNS lookup (less scalable than the uri-rsa option). ## Relay Configuration Relay operators can specify their identifier via a torrc option. OperatorIdentifier <FQDN> <proof-type> example: OperatorIdentifier example.com dns-rsa ## Length Limit Although DNS FQDNs can be rather long, we limit HAROIs to 40 characters. (As of December 2021 the longest observed HAROI is 28 characters long.) Operators will not be able to specify a HAROI longer than 40 characters in their torrc. Directory authorities refuse to accept them as well. ## Relays Descriptor Changes This proposal defines a new optional descriptor field that is automatically verified and voted on by tor directory authorities. operatorid <FQDN> <proof-type> ## Directory Authorities Directory authorities refuse to accept domains on the public suffix list [5]. XXX TODO ## Security Considerations Relay operators can trick directory authorities into performing DNS lookups and HTTPS GETs on arbitrary domains. Possible solutions: Directory authorities could required PTR+A DNS records on the same domain as the given FQDN for the relays IP address. [1] https://metrics.torproject.org/rs.html [2] https://gitlab.tails.boum.org/tails/onioncircuits [3] https://metrics.torproject.org/exonerator.html [4] https://yui.cat/ [5] https://publicsuffix.org/list/public_suffix_list.dat -- https://nusenu.github.io

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the consequences of deprecating debian alpha repos with every new major branch
by nusenu 21 Dec '21

21 Dec '21

Hi, tldr: - more outdated relays (that is a claim I'm making and you could easily proof me wrong by recreating the 0.3.3.x alpha repos and ship 0.3.3.7 in them and see how things evolve after a week or so) - more work for the tpo website maintainer - less happy relay operators [3][4] - more work for repo maintainers? (since a new repo needs to be created) When the tor 0.3.4 alpha repos (deb.torproject.org) first appeared on 2018-05-23 I was about to submit a PR for the website to include it in the sources.list generator [1] on tpo but didn't do it because I wanted to wait for a previous PR to be merged first. The outstanding PR got merged eventually (2018-06-28) but I still did not submit a PR to update the repo generator for 0.3.4.x nonetheless and here is why. Recently I was wondering why are there so many relays running tor version 0.3.3.5-rc? (see OrNetStats or Relay Search) (> 3.2% CW fraction) Then I realized that this was the last version the tor-experimental-0.3.3.x-* repos were shipping before they got abandoned due to the new 0.3.4.x-* repos (I can no longer verify it since they got removed by now). Peter made it clear in the past that the current way to have per-major-version debian alpha repos (i.e. tor-experimental-0.3.4.x-jessie) will not change [2]: > If you can't be bothered to change your sources.list once or twice a > year, then you probably should be running stable. but maybe someone else would be willing to invoke a "ln" commands everytime a new new alpha repo is born. tor-alpha-jessie -> tor-experimental-0.3.4.x-jessie once 0.3.5.x repos are created the link would point to tor-alpha-jessie -> tor-experimental-0.3.5.x-jessie It is my opinion that this will help reduce the amount of relays running outdated versions of tor. It will certainly avoid having to update the tpo website, which isn't a big task and could probably be automated but it isn't done currently. "..but that would cause relay operators to jump from i.e. 0.3.3.x to 0.3.4.x alphas (and break setups)!" Yes, and I think that is better than relays stuck on an older version because the former repo no longer exists and operators still can choose the old repos which will not jump to newer major versions. [1] https://www.torproject.org/docs/debian.html.en#ubuntu [2] https://trac.torproject.org/projects/tor/ticket/14997#comment:3 [3] https://lists.torproject.org/pipermail/tor-relays/2018-June/015549.html [4] https://trac.torproject.org/projects/tor/ticket/26474 -- https://twitter.com/nusenu_ https://mastodon.social/@nusenu

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