- tor-dev - lists.torproject.org

Pluggable transports research
by Jodi Spacek 25 Jan '18

25 Jan '18

I'm a master's student at the University of British Columbia (Vancouver, Canada) where I'm primarily researching anonymous systems and censorship. I would be delighted to contribute to pluggable transports. Of particular interest is image and audio data stenography - is anything is in the works for this or is it outdated? My aim is to add this functionality while fully testing and evaluating it as part of my thesis project. I refer to the list of idea suggestions here: https://trac.torproject.org/projects/tor/wiki/doc/PluggableTransports/ideas Any guidance is greatly appreciated. Thanks so much! Jodi p.s.: Please advise if this is not the correct mailing list. and perhaps belongs in tor-assistants. If so, I will inquire there once my access is (hopefully!) granted. -- www.jodispacek.com

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tor failing to resolve some dns records
by blaze glory 23 Jan '18

23 Jan '18

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WIP proposal for migration to TLS 1.3
by isis agora lovecruft 23 Jan '18

23 Jan '18

Hello, It's not done yet; it probably has errors; it definitely has omissions; it's still riddled with "XXX"s everywhere… but here's a work-in-progress draft proposal for migrating our link protocol(s) to use TLS 1.3: https://gitweb.torproject.org/user/isis/torspec.git/log/?h=tls13 It's not quite ready for a whole bunch of feedback yet, since I'm still reading through all the specs and writing the proposal. However, if you're super knowledgeable about TLS 1.3 and have opinions or ideas or see a mistake/misunderstanding somewhere, please feel free to share! Thanks! Best regards, -- ♥Ⓐ isis agora lovecruft _________________________________________________________ OpenPGP: 4096R/0A6A58A14B5946ABDE18E207A3ADB67A2CDB8B35 Current Keys: https://fyb.patternsinthevoid.net/isis.txt

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No Control Socket when DisableNetwork 1
by iry 20 Jan '18

20 Jan '18

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Dear Tor Developers, According to the Tor manual: https://www.torproject.org/docs/tor-manual-dev.html.en > DisableNetwork 0|1 When this option is set, we don’t listen for or > accept any connections other than controller connections, and we > close (and don’t reattempt) any outbound connections. Controllers > sometimes use this option to avoid using the network until Tor is > fully configured. (Default: 0) However, it seems when DisableNetwork is set to 1, /var/run/tor/control does not exist anymore making us cannot get a controller from socket file. (stem.control.Controller.from_socket_file() is affected in this case: https://stem.torproject.org/api/control.html#stem.control.Controller.fro m_socket_file) To reproduce this, I tested both Tor 0.3.1.9 and 0.3.2.9 on Debian Stretch: When DisableNetwork 0, run: systemctl --no-pager restart tor@default > user@host:~$ ls -l /var/run/tor/ total 1328 srw-rw---- 1 debian-tor > debian-tor 0 Jan 19 21:14 control -rw-r----- 1 debian-tor > debian-tor 32 Jan 19 21:14 control.authcookie -rw-r----- 1 > debian-tor debian-tor 1350116 Jan 19 21:14 log srw-rw-rw- 1 > debian-tor debian-tor 0 Jan 19 21:14 socks -rw-r--r-- 1 > debian-tor debian-tor 6 Jan 19 21:14 tor.pid When DisableNetwork 1, run: systemctl --no-pager restart tor@default > user@host:~$ ls -l /var/run/tor/ total 1244 -rw-r----- 1 debian-tor > debian-tor 32 Jan 19 21:00 control.authcookie -rw-r----- 1 > debian-tor debian-tor 1269005 Jan 19 21:00 log I searched on Tor-trac but did not find any similar report. Therefore, would you please tell me wether Tor intentionally behaves like this or this is a bug? (If this is a bug, I can definitely help to report it to Tor-trac.) Thank you so much! Best Regards, iry -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEzKSpZKlpRovTotu+oUtNvG3N1TwFAlpifX0ACgkQoUtNvG3N 1TwLsBAAn8W3H7VMwiR9UwnVJoXOZ0iWRLbF/JdtDUjXcG1/cQmK5aEHtbVCy4Jl VOWYKBJeHxZAmHlBC+ZR3E/vyDesatjPDIPvzUuwYN3T0COFpMyN71ipOjs1KqYP GFFgLFzClQHvnThe59TIEomVcdXIt9ebPU3QmVxnNhvB/KKggKOgTuYd/n8R0efe 0kAl5/8vZZv4/IiorRkF/ltQwmnOTR1V2H1OrOOHM/AyxLGfwGO9KffznRDX/BN4 AdM4MWpMh3+DKCKgJZpf3Gzwcn7d6DvL74YQVIhmwofoxEOCBD/f+iYeJKkoVPw7 Pd8YHkYvXqCRqHBFfTEe4BtZdcxK2k3FXbUcbKahFDYMtdotdzknf542f6+Bbt+p hmiuJT8bX/Kn2dBzonbqJuh2XEBA2y6OqqhJaVoJr5l6tWyghp18BsA2m6W4mg2H ApkUTv0YsQ8guXckfJP2LOhXxKWN0yncQ7bMzGZSfSwtqGwrDxFFWk2V8vXIrWWL X5pz3oObvQB9eUJcKix2C29kJSGBry68Ts1x4MnL14CDw0WqNqAqe0O3IAiCANjl CU+z9P129eb/pdYXW/OTFnVyWhQBXNvCRHTZB7Yvym+dN4B6MD3uOkH9THf9BaCF yVCOK1c04/sfqADnpE3Rhkr98iix3N2gbdOod/10T+GyG4OBh64= =Oh0M -----END PGP SIGNATURE-----

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(no subject)
by blaze glory 16 Jan '18

16 Jan '18

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Error-Correcting Onions with Bech32
by nullius 12 Jan '18

12 Jan '18

# Synopsis The Bech32 standard for error-correcting base32 strings was developed explicitly for relative ease and reliability in human communication of pseudorandom bitstrings. I invite discussion of specifying Bech32 as an alternative means for representing RFC 7686 .onion domain names. Should the response hereto be positive, then I will offer a formal proposal. I have written and released a tool which automatically recognizes and encodes/decodes .onion addresses in Bech32. To complement whatever I here say, please get a hands-on feel for Bech32 .onions: https://github.com/nym-zone/bech32 Manpage (yes, a real manpage!): https://raw.githubusercontent.com/nym-zone/bech32/master/bech32.1.txt # Background: About Bech32 Bech32 is specified by the Bitcoin BIP 173 standard,[1] co-authored by Pieter Wuille and Greg Maxwell. According to Mr. Maxwell, “Bech32 is designed for human use and basically nothing else”; the underlying research and development process involved extensive testing with human users, analysis of NIST visual confusability data, and the integration of a BCH code with strong error correction and detection properties. [1] https://github.com/bitcoin/bips/blob/master/bip-0173.mediawiki I refer to BIP 173 for further explanation of Bech32’s design properties, its rationales, and the limits of its error handling. A specific application of Bech32 is Bitcoin’s new address format for the future, which I call “Bravo Charlie Addresses” after the letters “bc” specified for Bitcoin addresses in the standard’s “human-readable part” (HRP). However, the standard was written to permit general use in other applications. Having in hand a standard explicitly designed to ease the pain which wetware suffers when it comes into contact with pseudorandom gibberish, the cypherpunk in me is overjoyed at the potentials. One is a concept which I call “PGP Descriptors”, which I am currently working to specify with a few extra features and nuances. And of course, I think of .onions! # Bech32 for .onion I hereby nominate “onion” as the logical HRP for RFC 7686 .onion special-use domain names. Here is Bech32 .onion by example, using my bech32 tool with its built-in .onion support to encode and decode the name for the Tor Project’s .onion equivalent of its “www” site: ``` $ bech32 -e expyuzz4wqqyqhjn.onion onion1yh0c5eeuksscs8fdyd8406 $ bech32 -d onion1yh0c5eeuksscs8fdyd8406 expyuzz4wqqyqhjn.onion ``` The string is longer, because it contains 6 base32 characters’ worth of error-correcting code. N.b. also, the foregoing should work just fine for v3 onions (formerly prop-224). Imagine the impact on users who have a practical need to transmit a .onion address by verbal communication, or via a handwritten note. Now they can get some help with errors, instead of wondering why they can’t connect to a nonexistent .onion site. The standard enjoins applications against autocorrecting Bitcoin addresses, so as to prevent even the slightest possibility of causing funds loss by being too “helpful”. But in applications where it would be safe to do so, Bech32 can indeed correct small errors (as well as reliably detecting much worse errors). I suggest that such automatic correction would be suitable for .onion addresses. Bech32 co-author Dr. Wuille (sipa) has published Javascript reference code, plus a Javascript error-correction demo, under an MIT license. Perhaps this may be easily adapted into Torbutton, for automagic decoding of Bech32 “onion1” to .onion domains in the Tor Browser address bar. The code is in the same repository whence I copied the Bech32 reference C code I use internally in my tool: https://github.com/sipa/bech32 # Conclusion—or, to be continued... An alternative representational format with error-correcting codes will make .onion addresses more human-friendly. I look forward to the day when “onion1” addresses can be passed by handwritten notes, vocalized with a radio alphabet, stuffed into QR codes, scrawled on parchments placed in bottles tossed to sea, rocketed into space, and then conveniently transformed with appropriate corrections into the DNS-style .onion format specified by RFC 7686. Here’s to the alternative Onion format of the future! -- nullius(a)nym.zone | PGP ECC: 0xC2E91CD74A4C57A105F6C21B5A00591B2F307E0C Bitcoin: bc1qcash96s5jqppzsp8hy8swkggf7f6agex98an7h | (Segwit nested: 3NULL3ZCUXr7RDLxXeLPDMZDZYxuaYkCnG) (PGP RSA: 0x36EBB4AB699A10EE) “‘If you’re not doing anything wrong, you have nothing to hide.’ No! Because I do nothing wrong, I have nothing to show.” — nullius

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New Fallback Directory File Format
by teor 12 Jan '18

12 Jan '18

Hi all, Some time in the next few weeks, the Tor fallback directory mirror file format will change. This affects stem and Relay Search, which parse this file. Change Description Here is a list of changes to the file format: * the "weight" line has been removed, and replaced with a Tor config default (#24679, #24681) * the comma that separates fallback C strings is now on its own line * a "nickname" comment has been added (#24600) * an optional "extrainfo" comment has been added (#22759) The added fields will be populated with placeholders until the list is rebuilt (#22271). This will hopefully happen some time in the next few weeks. Requesting More Extra Info Caches There are only a few fallbacks that cache extra-info documents. I checked 67, and only 4 cached extra-info documents. atagar, do you want me to ask some fallback operators to set DownloadExtraInfo 1? What number or proportion would you like? (We allow approximately 25% of fallbacks to go down before we start to rebuild the list. In the worst case, this can mean that ~40% are down at some point.) Example Entries A sample entry in the new format, using actual relay info: "5.9.110.236:9030 orport=9001 id=0756B7CD4DFC8182BE23143FAC0642F515182CEB" " ipv6=[2a01:4f8:162:51e2::2]:9001" /* nickname=rueckgrat */ /* extrainfo=1 */ , The current fallback file in the new format, with placeholders: https://github.com/teor2345/tor/blob/ticket22759_tree/src/or/fallback_dirs.… A small sample fallback file in the new format, with actual relay info: https://trac.torproject.org/projects/tor/attachment/ticket/22759/fallback_d… Please let me know if you would like any changes to the format. T -- Tim Wilson-Brown (teor) teor2345 at gmail dot com PGP C855 6CED 5D90 A0C5 29F6 4D43 450C BA7F 968F 094B ricochet:ekmygaiu4rzgsk6n xmpp: teor at torproject dot org ------------------------------------------------------------------------

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Agnostic Tools: Code Dev and Support For
by grarpamp 12 Jan '18

12 Jan '18

> I'm interested in helping you guys with Tor development. I don't really care > what I work on, except I do not support .onion websites (though I am willing > to be convinced otherwise) so I would prefer not to participate directly in > their development. I have plenty of experience with writing code Folks in convo before have covered some of these areas and more that one could surely find or think of... Philosophical... Why does someone want to support and develop for Tor, or any other overlay p2p anonymity network, or crypto, for that matter? When even a fix to the manpage could be read and used by onion users and operators, same for metrics, lists, or any other part of the ecosystem. Does one fear "bad" things, association, or support "good" things? Does freespeech, anonymity, privacy, human rights sound "good"? What is "bad"? Censorship? Theft, Dictatorships, Police States, whether one's own, that of the Enemy, or that of the Oppressed? Cryptocurrency, anonymity, free markets, privacy, messaging... "bad"? "Good" [only] when used to defeat "bad" things inside or outside of [mal]functional democracies that assert majority force over minorities who have forced no one? Ricochet, Signal, GPG... "bad"? New technology that forces change over old entrenched ways... "bad"? Are anonymous forums where professional therapists give pro bono counseling to even the most reviled, depraved, criminal, socially scarlet lettered and outcast... "bad"? Materials and talk of religion? Are datamining, traffic archiving, exploits, cleartext... "good"? Tor has exits... do people realize how much of both what they like to "support", and abhor, travels over those exits? The variety of traffic there is no different than onions. Should exits be unsupported? What about the internet, or printing presses, should those tools be unsupported? Are they "bad", get their makers looked askew? Onions, exits, internet, presses, hammers... all simply agnostic tools. Tools can be used to build great things, to defend, or to wield in bloody murder. And what of biases over certain agnostic tools instead of over the separate "good" or "bad" uses of them? Do other tool builders and users have to wonder if their tools are being compromised by those with such biases? What of when those with biases end up needing the tools themselves, what will be the tool quality, or their ability to do "good" with them? Have people taken the time to explore the onion space to find and participate in all the "good" things they like therein, to create and grow them, or even engage in counsel and advocacy against the "bad"? What tools would be needed to do that? Yes, people are free to work on what they like... including giving deep thought as to what they like and don't, and why, and how supporting agnostic tools can actually fit with that. Are not your pens tools? Who likes those? Who supports those? What if they didn't? Pens... write code. Tech, fun, politic... Amounting to consideration feature X may prevent or diminish a better archictecture on balance for some higher importance feature Y. That should be covered open devops as usual. Or if the *technology* or *code* of eg: eepsites onions, or other subsets of various projects are not in their interest or knowledge practice area. Ok. Or if the features provided by any overlay network or tool are deemed flawed, and the technical or political effort to get them fixed, or rearchitecture, or correctly advertised, or called out within as bunk, is too high, therein it may be better to abandon them and or speak out freely as such.

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Volunteering for Tor
by Charles Hunt 12 Jan '18

12 Jan '18

After 15 years of desktop support, I am following my passion to be a Python3 programmer. I am still an amature programmer, but I aced the python fundamentals course from Coursera to flesh out my skills. I would like to continue developing my programming skills by volunteering for Tor. Do you have something I can help with? Thank you. Charles

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Re: [tor-dev] A suggestion for differential private statistics gathering
by Eyal Ronen 11 Jan '18

11 Jan '18

Hi Tim, First of all thanks for your detailed and quick response. I am sorry for my delayed response as I am attending Real World Crypto (BTW if there are any devs here it will be nice to try and meet). I will try to answer your questions and remarks below. >Hi Eyal, > >Thank you for letting us know about your research. > >You've emailed an internal discussion list, so I'm going to direct all >responses to the public tor-dev@ list. That is the list where we discuss >changes to Tor. > >Please see my response below: > >> On 7 Jan 2018, at 20:31, Eyal Ronen <eyal.ronen(a)weizmann.ac.il> wrote: >> >> I am a PHD student, and have just published online a paper, that shows a protocol that I think might be relevant to the TOR network. >> The protocol allows a server to privately learn information from a client, and is resilient to a situation where a malicious adversary wants to temper with the statistics. >> The main use case in our paper is learning popular passwords, > >Are you aware of this password list? >(It has no privacy apart from hashing the passwords, because the >passwords are already publicly available in data breaches.) > > https://www.troyhunt.com/introducing-306-million-freely-downloadable-<https://www.troyhunt.com/introducing-306-million-freely-downloadable-pwned-…> pwned<https://www.troyhunt.com/introducing-306-million-freely-downloadable-pwned-…> -passwords/<https://www.troyhunt.com/introducing-306-million-freely-downloadable-pwned-…> One of the assumptions of our paper is that if we blacklist known vulnerable passwords, we will change the passwords distribution and new passwords will become "popular". We enable the server to continually learn the changing password distribution. Another example is that the previously popular password "superman" might be replaced today with the password "wonderwoman", and we want to be able to learn this kind of changes. > >> but we believe that it might also be usable for other cases in the TOR network. As we do not know the needs and challenges in the TOR network, we would greatly appreciate any feedback from the TOR metrics community. > >I would be interested in an explanation of the tradeoffs between the >16 and 32 bit versions of the protocol. In particular, we may not be >able to provide servers with 4 GB of RAM for the 32 bit protocol. > >What would we lose with a 16 bit version? Is a 24 bit version possible? Any bit number is possible , and without any impact on security. The number of bit is the size of the domain or histogram of items you want to measure. If you use a low number of bits, you can have collision between different measured values, that may change the statistics. For example, lets assume we want to find out popular sites in the TOR network. We encode the sites IP. If you use 32 bit version, you can measure each IP individually. Otherwise you use a truncated a hash of the IP address. Now when you find a heavy hitter, you know what possible IP contributed to this measurement. But you can't know which one or more IP addresses are the popular ones. However I believe that this might not be a problem. One of the main differences to other solutions is that we work in the "Local model" and do no require any "Tally Reporters" to protect the data or for answers to be aggregate on the relay servers. The only place that needs to store the whole histogram is the one server that aggregates all of the information. I think that it greatly reduce the communication and implementation overheads of the solution. I think that the main differences are the one above and our provable malicious resilient. There are other differences but I think that this is the most relevant one. If we don't care about malicious users or relays we can use the semi honest version, that takes have almost zero computation requirements, and can be done either by the user, or by the relay. If we want to use the malicious resilient, it is a bit more costly, and we need to think of the right way and place to incorporate it. If it sounds interesting I will like to find a possible use case that I can try and design the best tailored solution for you. And we can try to prove the security and complexity of the solution, and verify this with safety board. If needed I have a POC written in Python to be easily understandable, but I can easily implement it using TOR's cryptographic package of choice. I will also try to go over the current proposal on the other papers in more details. Thanks again, Eyal Ronen > >> The paper is titles "How to (not) share a password: Privacy preserving protocols for finding heavy hitters with adversarial behavior" and can be found at https://eprint.iacr.org/2018/003 >> >> The abstract is: >> "Bad choices of passwords were and are a pervasive problem. Most password alternatives (such as two-factor authentication) may increase cost and arguably hurt the usability of the system. This is of special significance for low cost IoT devices. >> >> Users choosing weak passwords do not only compromise themselves, but the whole eco system. For example, common and default passwords in IoT devices were exploited by hackers to create botnets and mount severe attacks on large Internet services, such as the Mirai botnet DDoS attack. >> >> We present a method to help protect the Internet from such large scale attacks. We enable a server to identify popular passwords (heavy hitters), and publish a list of over-popular passwords that must be avoided. This filter ensures that no single password can be used to comprise a large percentage of the users. The list is dynamic and can be changed as new users are added or when current users change their passwords. We apply maliciously secure two-party computation and differential privacy to protect the users' password privacy. Our solution does not require extra hardware or cost, and is transparent to the user. >> >> The construction is secure even against a malicious coalition of devices which tries to manipulate the protocol in order to hide the popularity of some password that the attacker is exploiting. We show a proof-of-concept implementation and analyze its performance. >> >> Our construction can also be used in any setting where one would desire to privately learn heavy hitters in the presence of an active malicious adversary. For example, learning the most popular sites accessed by the TOR network." > >Tor Proposals > >There is a current proposal to add privacy-preserving statistics to Tor >using a scheme that's based on PrivCount: > > https://gitweb.torproject.org/torspec.git/tree/proposals/288-<https://gitweb.torproject.org/torspec.git/tree/proposals/288-privcount-with…> privcount<https://gitweb.torproject.org/torspec.git/tree/proposals/288-privcount-with…> -with-shamir.txt<https://gitweb.torproject.org/torspec.git/tree/proposals/288-privcount-with…> > >PrivCount is limited to counters with integer increments, so we can't >easily find the most popular site (the mode), or calculate the median. > >We discussed the proposal on tor-dev@, and decided that we could add >more sophisticated statistics later. We would appreciate your feedback >on the proposal. In particular, please let us know if there is anything >we should change in the proposal to make it easier to extend with schemes >like yours in future. > >Here is the proposal thread: > > https://lists.torproject.org/<https://lists.torproject.org/pipermail/tor-dev/2017-December/012699.html>pipermail<https://lists.torproject.org/pipermail/tor-dev/2017-December/012699.html>/tor-dev/2017-December/012699.html<https://lists.torproject.org/pipermail/tor-dev/2017-December/012699.html> > > >Anyone is welcome to submit Tor proposals, the process is described here: > > https://gitweb.torproject.org/torspec.git/tree/proposals/001-process.txt > > >Related Research > >There was a paper at CCS 2017 that sounds very similar to your scheme: > >Ellis Fenske, Akshaya Mani, Aaron Johnson, and Micah Sherr. Distributed >Measurement with Private Set-Union Cardinality. In ACM Conference on >Computer and Communications Security (CCS), November 2017. > >Source: http://safecounting.com/ > >Can you explain how your scheme differs from PSC? > > >There's a forthcoming paper at NDSS 2018 that measures a single onion >site's popularity with differential privacy using PrivCount: > >Inside Job: Applying Traffic Analysis to Measure Tor from Within >25th Symposium on Network and Distributed System Security (NDSS 2018) >Rob Jansen, Marc Juarez, Rafael Galvez, Tariq Elahi, and Claudia Diaz > >Source: https://onionpop.github.io/ > >But the measurement was limited to one site, because PrivCount can't >calculate the modal value from set of samples. So I can see the >advantages of a scheme like yours over PrivCount. > > >Your Own Research > >And finally, if you do want to do research on the public Tor network, I >would recommend contacting the Tor Research Safety Board for advice: > > https://research.torproject.org/safetyboard.html > >T > >-- >Tim Wilson-Brown (teor) Best regards, Eyal

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