- tor-dev - lists.torproject.org

REMINDER: Buoyant Otter outreach, training, & documentation in an hour.
by Tom Lowenthal 29 Oct '13

29 Oct '13

Tor psyops group, We'll be meeting in #tor-dev in just under an hour to scheme, plan, and otherwise prepare out ongoing outreach, training, and documentation efforts. See y'all in an hour. -Tom

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Why the limited HW engine algos in crypto.c?
by Joshua Datko 28 Oct '13

28 Oct '13

Why is there a limited set of OpenSSL engine algorithms chosen in crypto.c (code below)? log_engine("RSA", ENGINE_get_default_RSA()); log_engine("DH", ENGINE_get_default_DH()); log_engine("RAND", ENGINE_get_default_RAND()); log_engine("SHA1", ENGINE_get_digest_engine(NID_sha1)); log_engine("3DES", ENGINE_get_cipher_engine(NID_des_ede3_ecb)); log_engine("AES", ENGINE_get_cipher_engine(NID_aes_128_ecb)); Crypto hardware may be able to support various modes/key sizes and I would have thought one would want to support the algorithms allowed in TLS from the tor spec (MUST support SSL_DHE_RSA_WITH_3DES_EDE_CBC_SHA and SHOULD TLS_DHE_RSA_WITH_AES_128_CBC_SHA). Also, I was a bit surprised to see ECB mode. Is it true that ECB, when used as a stream generator, is equal to CTR mode? ECB mode is not mentioned in the spec and after some digging, I found a reference to it [1] for encrypting at most one block length of data in the header. To rephrase the opening question, it appears, by my limited review, that there is support for only a subset of the algorithms that Tor uses; what are the implications of increasing this support? Thanks, Josh [1] https://lists.torproject.org/pipermail/tor-commits/2012-July/044878.html p.s. My motivation for this question is that I'm trying to optimize the performance of the TI AM335X for use on the BeagleBone Black. While it can't compete with high end servers, it appears to hold its own behind a home network. Unfortunately, the processor doesn't support any asymmetric algorithms, which would help in circuit creation, but it does support various flavors of AES as well as SHA1.

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Sponsor F: final Y3 meeting at 1100 Pacific today
by Tom Lowenthal 28 Oct '13

28 Oct '13

Happy Monday, This is your just-a-smidge-more-than-an-hour reminder that the final Sponsor F year 3 meeting will be in #tor-dev at 1100h Pacific. Bring true tales of your work, the final reports you've been preparing, and -- probably -- snacks. Sadly, I suspect that this meeting will last slightly more than the 90 assigned minutes. I plan to proceed in deliverable number order, so you may be able to use that as a gauge. If you can only be near the beginning or the end of the meeting, I'd love to know that forthwith so that I can jazz up the order for optimal conveniencing. Also, in the unlikely event that I still have your attention, it'd be really super neat if you could drop into the [Sponsor F year 4 riseup pad][1] and make sure that anything which sounds like you might want to help has your name near it, and that anything you might want to take point on has not just your name, but also as many time, difficulty, chance of success, and alternate result descriptions as you can. See y'all in an hour or so. -Tom 1: https://pad.riseup.net/p/Vt0TDXcdH0PB_Tor-Sponsor-F_Year-4 On 30 September 2013 19:13, Tom Lowenthal <me(a)tomlowenthal.com> wrote: > Today, at 1100 Pacific, we spent more than 90 minutes discussing > [Sponsor F][]. Here's the summary. > > **READ THIS**: The next Sponsor F meeting will be held in a mere two > weeks on **2013-10-14, at 1100h Pacific in #tor-dev**. > > This is a schedule change: from now on, the meetings will be every two > weeks. It's possible that we may have to increase this to every week, > depending on how fast we work, and how long meetings are taking. If > you should be at these meetings but cannot make Mondays at 1100h > Pacific, please contact me, and I'll start the process of finding a > better time or times. > > If you are individually in the `cc` field of this message, it's > because I think that there's something which I think you need to do > for Sponsor F before Halloween. You should also come to the next > Sponsor F meeting. If you can't make the meeting, or don't think this > work applies to you, you should get back to me ASAP so we can fix it. > > Is something else missing, wrong, or messed up? I'd like to know. > > [Sponsor F]: https://trac.torproject.org/projects/tor/wiki/org/sponsors/SponsorF/Year3 > > > * * * * * > > > Core Phase 2 Deliverables > ========================= > > > UDP Transport [#10] > ------------- > > **[On Track: Minimal]** Karsten will work with Rob to complete the > Shadow simulation of this work, then write up a full report on this, > probably with Stephen's help. We expect both tasks to be complete by > Halloween. This likely represents a minimal outcome for this > deliverable. > > > Combine obfuscation (obfsproxy) with address-diversity (flashproxy) [#11] > ------------------------------------------------------------------- > > **[On Track: Minimal]** The work of integrating obfsproxy with > flashproxy is done. George will include this in the next released > version of the pluggable transports browser bundle. George will also > write a report on this work. Ximin and David will help. By Halloween, > the report will be complete and the bundles will either be released or > well on their way through testing. This likely represents some > combination of minimal or intended outcomes for this deliverable. > > > Bridge Metrics [#12] > -------------- > > **[Done: Intended]** Our reporting code has been merged into master. > It will ride the trains or flow downstream or whatever your favorite > code development cycle imagery is, and show up in future releases. As > it goes through alpha, beta, and release, gets picked up and adopted > by more operators, we'll get more comprehensive sample coverage, and > better data. This likely represents an ideal outcome for this > deliverable. > > > N23 Performance Work [#13] > -------------------- > > **[On Track: Alternate]** Roger doesn't think that N23 is as good as > we thought it was, so he's going to write a report on the various > performance improvements we've implemented lately; the performance > work which we though about, but decided not to implement, and why; and > a wishlist of future performance work and research. He'll have this > done by Halloween. This likely represents an alternate outcome for > this deliverable. > > > Improved Scheduling [#14] > ------------------- > > **[On Track: Intended]** Nick will work with Roger and Andrea to > implement an improved scheduler (possibly based on picking randomly, > weighted by bandwidth), and -- if possible -- also to refactor `cmux`. > If time permits, Nick will also attempt to simulate this using Shadow > , probably with Karsten's help. Finally, Nick will produce a full > report before Halloween. This likely represents an intended outcome > for this deliverable. > > > Alternate `Fast` Flag Allocation [#15] > -------------------------------- > > **[At Risk]** The person who we initially expected to do this work > does not seem to be available to do it. We need to find an alternate > plan to execute this deliverable. If you think you can do it, please > read [ticket #1854][#1854] and get in touch. > > [#1854]: https://trac.torproject.org/projects/tor/ticket/1854 > > > VoIP Support [#16] > ------------ > > **[On Track: alternate]** Our implementation strategy for this was > high-latency send-an-mp3-over-XMPP using Gibberbot/Chatsecure, or a > similar system. The internal milestone was to have a release candidate > available today. Sadly, Nathan (who is on point for this) wasn't on > the call. Fortunately, Nathan [blogged][guardian-1] about Chatsecure's > `12.4.0-beta4` ten days ago, and a tantalizingly-named > [`ChatSecure-v12.4.2-release.apk`][chatsecure-release] > ([sig][chatsecure-release-sig]) is available in the Guardian Project > [release directory][guardian-releases]. The outlook seems good, but > Tom will follow up with Nathan as soon as possible to verify these > outrageous claims. Nathan, if you're reading this, could you get in > touch (email, IRC, XMPP, whatever). Thanks! > > [guardian-1]: https://guardianproject.info/2013/09/20/gibberbots-chatsecure-makeover-almo… > [chatsecure-release]: > https://guardianproject.info/releases/ChatSecure-v12.4.0-beta4-release.apk > [chatsecure-release-sig]: > https://guardianproject.info/releases/ChatSecure-v12.4.0-beta4-release.apk.… > [guardian-releases]: https://guardianproject.info/releases/ > > > > Extended Phase 2 Deliverables > ============================= > > > VoIP Support [#17] > ------------ > > **[Limbo: Intended]** Here we're talking about getting a general VoIP > client (Mumble) to work over Tor. This discussed in [ticket > #5699][#5699], and [instructions][torify-mumble] for using Mumble over > Tor are on the wiki. We didn't get an update during the meeting, so if > you're working on this, get in touch, eh? > > [#5699]: https://trac.torproject.org/projects/tor/ticket/5699 > [torify-mumble]: > https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO/Mumble > > > Simulating Tor [#18] > -------------- > > **[On Track: Intended]** Linus will finish Shadow improvements as > needed, and write a full report on his Shadow work. That'll all be > done by Halloween. This probably represents the intended outcome of > this deliverable. > > > Relays as Bridges [#19] > ----------------- > > **[Done: Minimal]** Using a public relay as a bridge works. > > > Defiance [#20, #21] > -------- > > **[At Risk]** We cannot work on these without open Defiance code. > > > Throttling Classifiers [#22] > ---------------------- > > **[On Track]** Adaptive throttling seems to come with unpleasant > anonymity tradeoffs, so we're not doing that right now. It looks like > static throttling will work really quite well, without these > tradeoffs. > > > Torbrowser Optimistic Data [#23] > -------------------------- > > **[Done: Ideal]** It's in your TBB *right now*. > > > > > FAQ > === > > **Q**: Why do you keep talking about Halloween? > **A**: We're currently in Phase Two of Year 3 of the Sponsor F > project. That phase ends on October 31st 2013, so we should try to > finish everything as best we can before then. Also: if we don't > finish, at midnight (local time) each person who has an outstanding > deliverable will be besieged by a seemingly-endless horde of zombies. > Others may be besieged too: the zombie report is hazy.

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Retiring old user number estimates
by Karsten Loesing 28 Oct '13

28 Oct '13

Hi everyone, some of you may already know our new approach to estimating daily Tor users: https://metrics.torproject.org/users.html#userstats This new approach is in beta since April, and I'm quite happy with it. I trust the new numbers more than the old ones, both for direct users and bridge users. The new code for direct users is quite similar to the old one, but much cleaner. The approach for bridge users is a much better idea than the old hack. Today I added the missing features like the top-10 lists and the censorship detector. Why do I tell you this? Because the old approach uses resources on our poor, already overloaded metrics machine, and I'm planning to shut down the old approach in the very near future. Here's the plan: - Compute user numbers for 2012 and before; the current numbers start on January 1, 2013. This is going to take at least until September 23. - Take out the "BETA" labels and throw out everything above "New approach to estimating daily Tor users (BETA)". This could happen on October 1. Thoughts? Did I miss anything that's worth keeping? Anyone want to create an archive of their favorite graphs before I pull the plug? All the best, Karsten

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Damian's Status Report - October 2013
by Damian Johnson 28 Oct '13

28 Oct '13

Hi all. Here's a quick update of what I was up to this October... ====================================================================== Stem Release 1.1.0 ====================================================================== After seven months of work Stem version 1.1.0 is finally out! https://blog.torproject.org/blog/stem-release-11 This month was primarily focused on pre-release performance and compatibility improvements in preparation for this... * Handful of improvements that reduced the memory usage of our Descriptor classes by 20%. [1] * Replaced Stem's custom caching with Python's @lru_cache. This was added to the standard library in Python 3.2, so Stem includes a Python 2.x backport to our utilities. [2][3] * Dozens of compatibility fixes for Python 2.6 and 3.x. * Added test coverage for Stem's interpretor examples, courtesy of Python's doctest module. [4][5] ====================================================================== GSoC Mentor Summit ====================================================================== Nick, Moritz and I attended the GSoC Mentor Summit at Google's main campus. By and large it was very similar to previous years, with many of the same faces and discussion topics. Unlike the prior couple years however I did not focus on keeping notes which, on reflection, was a mistake. Here's the small bit I remember... * Had a couple fun language discussions with developers from SciRuby and Scala. The former mostly concerned the advantages and disadvantages of Ruby with respect to Python (I use the former at work, so I've had some time to form an opinion on this). The later concerned Scala support for issuing database queries via list comprehensions. * Couple discussions with Wikimedia developers regarding Tor abuse. Unfortunately this is a perennial discussion that never seems to go anywhere despite having plenty of technical solutions. * Nick gave me a tour of Chutney's codebase and tried to persuade me to take on development of it. Nearly worked too. But while Chutney, SoaT, TorBEL, and a dozen other projects would be a lot of fun to work on I only have so much I can squeeze in alongside a full-time job. * A hackathon organizer with Random Hacks of Kindness discussed what they've found most successfully attracts contributors. The two most memorable tips were momentum and recognition. Regularly organizing events is necessary to maintain a core contributor group, and engaging local media doesn't hurt as it provides recognition for the contributors. * Shadowed Nick during discussions with a Mozilla developer concerning the upcoming Tor IM bundle. They certainly seem excited for OTR support... * Visited with Terry and Arc from the PSF quite a bit. Still no ETA on when distributions will switch to Python 3, and Mailman 3 is still a ways off. Momentum on lots of projects though. Evidently they acted as an umbrella org for roughly sixty students. I would weep bitter, bitter tears if I had to be the admin for that... ====================================================================== Other news this month includes... * Karsten, Andrew and I are now all moderators for the tor email lists. I'm taking point in this area, making daily sweeps through the moderator queue and tweaking Mailman to reduce friction. * Handful of DocTor fixes and improvements. Karsten shut down the Java DocTor early in the month so our shiny, new Python DocTor is now flying solo! * Attended events in the Seattle area including 'Go for Python Developers' at Google Fremont and the second TA3M meetup. * Worked with authority operators to resolve brief outages with dizum and urras. Cheers! -Damian

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Using Stem to monitor TBB usage.
by remi py 27 Oct '13

27 Oct '13

Hy, I am having trouble using Stem to connect to the tor controller, while at the same time browsing the web using the TBB. The tor control settings can be edited in Vidalia -> settings -> advanced. There it is configured by default to use port 9150 and a random password for authentication, but I can not see what password. If I change any of these settings, then I cannot browse anymore, and TB displays "The proxy server is refusing connections". I am using this snippet: import stem from stem.control import Controller with Controller.from_port(port = 9151) as controller: controller.authenticate('') # provide the password here if you set one bytes_read = controller.get_info("traffic/read") bytes_written = controller.get_info("traffic/written") print "My Tor relay has read %s bytes and written %s." % (bytes_read, bytes_written) from https://stem.torproject.org/tutorials/the_little_relay_that_could.html So my problem is that I can not connect to the tor controller while at the same time browsing using the tbb. How do I fix this? Kind regards, Rémi.

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This is my new OnionMail
by enfn 26 Oct '13

26 Oct '13

The first OnionMail server is working. OnionMail + Tails is simple!

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test
by enfn 26 Oct '13

26 Oct '13

Test

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Browser extension identification/fingerprinting mitigation?
by Griffin Boyce 26 Oct '13

26 Oct '13

Hi all, I'm looking at possibly replacing the images used by Cupcake with inline SVG XML, to reduce the possibility of fingerprinting/identifying Cupcake users who use Chrome [1]. One of the more talked-about methods of identifying a user's browser extensions is to look for images used by the extension (in Chrome at least), so this seems to make some amount of sense. [2] Does anyone have any thoughts on this? ~Griffin [1] https://chrome.google.com/webstore/detail/cupcake/dajjbehmbnbppjkcnpdkaniap… [2] http://blog.kotowicz.net/2012/02/intro-to-chrome-addons-hacking.html -- "Cypherpunks write code not flame wars." --Jurre van Bergen #Foucault / PGP: 0xAE792C97 / OTR: saint(a)jabber.ccc.de My posts are my own, not my employer's.

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Re: [tor-dev] Incorporating your torsearch changes into Onionoo
by Kostas Jakeliunas 25 Oct '13

25 Oct '13

On Fri, Oct 11, 2013 at 12:00 PM, Karsten Loesing <karsten(a)torproject.org>wrote: > Hi Kostas, > > should we move this thread to tor-dev@? > Hi Karsten! sure. >From our earlier conversation about your GSoC project: > > In particular, we should discuss how to integrate your project into > > Onionoo. I could imagine that we: > > > > - create a database on the Onionoo machine; > > - run your database importer cronjob right after the current Onionoo > > cronjob; > > - make your code produce statuses documents and store them on disk, > > similar to details/weights/bandwidth documents; > > - let the ResourceServlet use your database to return the > > fingerprints to return documents for; and > > - extend the ResourceServlet to support the new statuses documents. > > > > Maybe I'm overlooking something and you have a better plan? In any > > case, we should take the path that implies writing as little code as > > possible to integrate your code in Onionoo. > > Let me know what you think! > Sounds good. Responding to particular points: > - create a database on the Onionoo machine; > - run your database importer cronjob right after the current Onionoo > cronjob; These should be no problem and make perfect sense. It's always best to use raw SQL table creation routines to make sure the database looks exactly like the one on the dev machine I guess (cf. using SQLAlchemy abstractions to do that (I did that before)). Current SQL script to do that is at [1]. I'll look over it. For example, I'd (still) like to generate some plots showing the chances of two fingerprints having the same substring (this is for the intermediate fingerprint table.) (One axis would be substring length, another would be the possibility in (portions of) %.) As of now, we still use substr(fingerprint, 0, 12), and it is reflected in the schema. Overall though, no particular snags here. > - make your code produce statuses documents and store them on disk, > similar to details/weights/bandwidth documents; Right, so if we are planning to support all V3 network statuses for all fingerprints, how are we to store all the status documents? The idea is to preprocess and serve static JSON documents, correct (as in the current Onionoo)? (cf. the idea of simply caching documents: if we serve a particular status document, it gets cached, and depending on the query parameters (date range restriction, e.g.) it may be set not to expire at all.) Or should we try and actually store all the statuses (the condensed status document version [2], of course)? > - let the ResourceServlet use your database to return the > fingerprints to return documents for; and > - extend the ResourceServlet to support the new statuses documents. Sounds good. I assume you are very busy with other things as well, so ideally maybe you had in mind that I could try and do the Java part? :) Though, since you are much more familiar with (your own) code, you could probably do it faster than me. Not sure. Any particular technical issues/nuances here (re: ResourceServlet)? cheerio Kostas. [1]: https://github.com/wfn/torsearch/blob/master/db/db_create.sql [2]: https://github.com/wfn/torsearch/blob/master/docs/onionoo_api.md#network-st… (e.g. http://ts.mkj.lt:5555/statuses?lookup=9695DFC35FFEB861329B9F1AB04C46397020C… )

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