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An ANTLR 4 grammar for Tor bridge network statuses
by Karsten Loesing 05 Nov '15

05 Nov '15

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello developers, in the past few days I have been working on a grammar to parse Tor bridge network statuses and hopefully other Tor descriptors in the future. It's working, for some definition of working, but some issues remain and I need some help. I just uploaded my sources, consisting only of the grammar with a fair amount of documentation: https://people.torproject.org/~karsten/volatile/BridgeNetworkStatus.g4 Quoting from that file to facilitate discussion here: There are multiple goals of having a grammar for Tor descriptors available on CollecTor: 1. Translate descriptors to JSON for statistical analysis: Some tools and databases require Tor descriptors in a standard format like JSON. This grammar and a parser generated from it can help making that translation as easy as possible, also to keep future maintenance as low as possible. 2. Provide a basis for descriptor-parsing libraries: As of late 2015, there are three libraries for parsing Tor descriptors: metrics-lib for Java, Stem for Python, and Zoossh for Go. It would be beneficial to place as much knowledge about the descriptor format into a grammar shared by all those libraries and then generate parsers for different languages from that grammar. 3. Serve as documentation for the Tor directory protocol specification: Tor descriptors are already documented using a hand-written grammar, but that may contain slight inaccuracies because it's not verified. This grammar could fix that by either detecting inaccuracies while trying to rewrite it to an executable grammar form or by replacing the grammar in the specification documentation with this executable grammar. Open issues and questions: - Was it smart to explicitly include all those SP tokens in the rules, or should those be discarded right away by the lexer? The main reason for keeping them was to stay as close to the specification as possible, but maybe that has downsides on the other goals. - If a bridge uses a nickname (or other token that's supposed to be a STRING) that is also a keyword like "r" or "published", things get confusing. Try editing the input bridge network status and observe the result. But those are perfectly valid nicknames, so what can we do? - It would be really nice to use regular expressions in the grammar to match input more thoroughly than just ~[ \n]+, if only we can fix the lexer troubles. It's a pity that all that verification work would need to be duplicated in each of the language-dependent parsers. That kinda defeats the purpose. - Is it easy to walk the parse tree and output a JSON format *without* having to write code for each of the rules? Ideally, the translator would be 20 lines of code and not grow at all if we add 10 more descriptor types. Do we need to change the grammar for that? - The following may turn out to be a non-issue, but some descriptors require lines to be ordered, e.g., "accept" and "reject" lines in server descriptors, and we'll have to retain that order in the parse tree. This should be similar to how we parse entries, starting with "r" lines, but who knows. Feedback much appreciated! All the best, Karsten -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: GPGTools - http://gpgtools.org iQEcBAEBAgAGBQJWOcp+AAoJEJD5dJfVqbCrnQUH/2dp8ER6ZcEGBtHP+dPb/4p0 0tKb4eZobQhZNx3oQOc08nCJl3AEa+Vedep5Caa9MSNycopf7mBFEGtw2V5J3mKN w6D6cvSbSBoFhuh/+Q8oVj+6h0KkUaCVVMaTHefb63usM0EmjsEXvDjBXr+g5nhn q0RqM1Id3V38rs3pKi1JDwGU4w5X45gzUPOXbiNGig6wJuLN1e2cxfF4RdDmGzST JvjlH/KRV59NjMRvUAeTxZIXlz6fKwjTWWQ2PXUnuXAXNPVxYakzHNhiT7qXGro0 7ZFfIr7gwk9kZlF0oy6ltFC1mGgL4xk0vqlrOjvwrh+oAzIciurMcOddXEHwr3E= =DZ0Z -----END PGP SIGNATURE-----

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A quick and dirty UX evaluation of Tor Messenger
by Greg Norcie 04 Nov '15

04 Nov '15

Hi all, First of all, great work on Tor Messenger - it's awesome to see Tor pushing to be more accessible to non-technical folks. I decided to take some notes when installing + using for the first time, hopefully this will be helpful. While there are some minor issues, I'd like to stress that this is a great first step and considering this is the first general public release it's a very good design. /////// I'm on an OSX machine, so the first thing I see after clicking on the icon is a message that Tor can't be opened because it's from an unidentified developer. This would raise an eyebrow at least for most users. (And lessens the effectiveness of the warning if we are going to train users to ignore it) I right click and select "open" and there is a longish pause (>10s) which could frustrate new users, then the wizard appears. I don't chat often - I usually text my friends, and I don't want to use FB chat since it's tied to my real name. I remember that Twitter now has no DM limit. But it's not on the main list. I don't have any data to support this intuition, but I suspect that after XMPP, Twitter would be a popular protocol. I click once on "show all protocols" and click continue. There's only a few additional, Twitter being one of them. Not sure why this list wasn't present from the beginning. I get options for a local alias and "tracked keywords". I have no clue what the latter is, but it sounds like the concept of a taboo in Harry Potter, so for a laugh I put in "Voldermort". Now I'm authorizing Instabird. Fairly straightforward. Now I'm receiving a texted 2f code from twitter and entering it. Now I'm in, and I can see my Twitter timeline, which is interesting. I was expecting just a buddy list to send DMs, not timeline access. I post a tweet to my timeline, then want to send my boss a test DM. But I follow >1500 people, and have to scroll a lot to find him. I locate his name and double click, but nothing happens. At this point, I suspect a less security minded user might abandon the app. (I end up digging around a bit to find the functionality I need) [1] ("Your security preferences allow installation of only apps from the Mac App Store and identified developers.") -- /***********************************/ *Greg Norcie (norcie(a)cdt.org <norcie(a)cdt.org>)* *Staff Technologist* *Center for Democracy & Technology* 1634 Eye St NW Suite 1100 Washington DC 20006 (p) 202-637-9800 PGP: http://norcie.com/pgp.txt Fingerprint: 73DF-6710-520F-83FE-03B5 8407-2D0E-ABC3-E1AE-21F1 /***********************************/

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1-1-1 task exchange meeting on Thursday, Nov 5, 15:00 UTC in #tor-dev
by Karsten Loesing 04 Nov '15

04 Nov '15

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello devs, we'll have another 1-1-1 task exchange meeting on Thursday, November 5, 2015, 15:00 UTC in #tor-dev https://www.timeanddate.com/worldclock/fixedtime.html?iso=20151105T15 Quick reminder: The idea of the 1-1-1 task exchange meeting is that participants get 1 minute to describe a task that would take somebody else roughly 1 hour and that they will do within 1 week. It could be to review a document, write some analysis code, fix a small bug, and so on. It's best to come prepared with a task or two to get the most out of this. In a perfect world people would give one task for each task they take, but that is not required. https://trac.torproject.org/projects/tor/wiki/doc/1-1-1-task-exchange Hint: I'll bring at least two fresh tasks to tomorrow's meeting, one about database optimization and one about grammars for parsing Tor descriptors. Talk to you tomorrow at 15:00 UTC. All the best, Karsten -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: GPGTools - http://gpgtools.org iQEcBAEBAgAGBQJWOjrpAAoJEJD5dJfVqbCrNgAIALHKS1JPtqhq6IGCRrgSIcuB 6Z8gJSc8KB7L/d89i3DwonNk3W0fzKZnLzT2FgUMFwfkL8ehEOw6rB86vL/d1K4o S+9Q71bvUWFP1BjRTCnFsOfC79Jz9aC3QvT69Q9/ULNGyRqsGypaop31h7Y6CE6d acUSSjvKiWxY+hFflZNq9RcugoSyDTasV7IlYulZduc/PMChOdR1FM5kBiXRVL40 Dgd3m71YILW8Ce9CWbwBVi6CD5lrVSRyDWG/I8dKBV206Y6z0BStj/wKrqnRvE9/ GOV0graoqh2kDSD2S3X81PuXlo+QcQU+lDy5nRKB5EcnTEiuXLz9Emph1GNUd2w= =Jwbg -----END PGP SIGNATURE-----

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running a BWauth
by starlight.2015q3＠binnacle.cx 04 Nov '15

04 Nov '15

I am considering starting up a passive BWauth in order to understand how they work and fix bugs. What is the minimum and ideal hardware configuration for a BWauth? Have my eye on an OVH config with unmetered 1G, a fuzzy promise of 500mbps minimum bandwidth and a 3.4GHz 4core/8thread AES-NI CPU: http://ark.intel.com/products/80910 The server could be turned up in any of their facilities: https://www.ovh.com/us/about-us/datacenters.xml Or is 10G a requirement? (out of my league) Is all code here https://gitweb.torproject.org/torflow.git/tree/NetworkScanners/BwAuthority or is there more? Are uncommitted fixes lying around anywhere? Thanks

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[Fwd: UX Principles]
by Mike Perry 03 Nov '15

03 Nov '15

Nima sent this to me a while ago and I completely forgot to forward it on. Note the Google docs and the PDF at the bottom. Useful food for though for Tor Messenger, Tor Browser, and other user-facing stuff. ----- Forwarded message from Nima Fatemi <nima(a)torproject.org> ----- Date: Fri, 24 Jul 2015 03:39:31 +0000 From: Nima Fatemi <nima(a)torproject.org> To: Mike Perry <mikeperry(a)torproject.org> Subject: UX Principles Hi Mike, sorry for late email. I was meaning to send you this sooner but I've had a big pile of email, I had to take care of. So the forwarded message below includes an attachment, which is the Yee's principles and then there's another paper that linda has mentioned, which is worth reading I think. Here's that talk from Google Chrome's Elisabeth Morant that I mentioned to you: https://news.yahoo.com/video/yahoo-trust-unconference-security-ux-161037378… Here are the slides: (the good stuff start from page 12) https://docs.google.com/presentation/d/1i2Pwennj8PcsigACPA1oLpRNLd7BVC0oils… And here are my notes from the talk + my thoughts added to them: - 1st principle: Don't annoy users, even with updates. - People (even infosec ppl) ignore updates - users are often worried that updates would change the interface, it took them time and energy to get used to current things, they dont want it to change (even if it's a good change) - Enable auto-update by default with an option to opt out - Give devs and users tools to time permission requests - 2nd principle: allow mistakes!!! let them change their settings easily if they've changed their minds - settings windows doing similar thing should look similar and if they do the exact things, they should look identical. - make settings easy to discover - 3rd principle: combat jerks [malicious-HS_maybe?] - danger is hard to communicate - how to tell users about the danger they're facing - infrastructure for detecting and reacting to badness - how to do this in a decentralized way?! - karma! tie user engagement to resource allocation (maybe useful for HiddenServices?) (okay, right after writing this sentence, I started a conversation in #tor-project. see the backlog, you might find it interesting) - crowd consent Let me know if I can be of any help. Bests, -- Nima -------- Forwarded Message -------- Subject: Yee's principles Date: Wed, 1 Jul 2015 05:51:05 -0700 From: Linda Naeun Lee <lnl(a)berkeley.edu> To: Tor Project <nima(a)torproject.org> Nima: Here are notes. And another paper. http://zesty.ca/pubs/yee-sid-ieeesp2004.pdf -- Linda Naeun Lee Graduate Student Researcher Department of Computer Science University of California, Berkeley ----- End forwarded message ----- -- Mike Perry

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UX tag
by Nima Fatemi 02 Nov '15

02 Nov '15

Hello devs, May I encourage you to add "UX" tag (keyword) to the tickets you're filing or working on that are related to usability in any ways? This is to get a sense of how many tickets and what workload is related to usability in tor-related products. So I want to humbly ask you to use the tag regardless of the help you may or may not need for that ticket. And if you've any suggestions/ideas to measure this better, this is a great time to talk about it :) Peace ✌ -- Nima 0XC009DB191C92A77B | @mrphs "I disapprove of what you say, but I will defend to the death your right to say it" --Evelyn Beatrice Hall

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Re: [tor-dev] Update of prop#250: Random Number Generation During Tor Voting
by Jesse V 01 Nov '15

01 Nov '15

David, I'm in the midst of reworking my OnioNS design around prop250 (and the security analysis therein) and as far as I can tell these changes make sense. I like the 00:00 -> 24:00 change as it's more intuitive as you said. I was at first very concerned that you removed the majority requirement as that is the assumption made during consensus generation, but I think your argument for the new conflict resolution make sense. I'm excited that the implementation is nearly complete and I look forward to seeing it in Tor infrastructure! Jesse V. On 10/28/2015 10:26 AM, David Goulet wrote: > First, period have been changed from 12:00 -> 12:00 (24 hour) to 00:00 > -> 24:00 so the protocol run is not over two days. Seemed more logical > and less confusing :). > > Second, we've removed the need of having majority for a commit to be > considered for the shared random computation. Yes this sounds intense!! > so it needs your attention.

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Tor logo
by Philip Lammert 01 Nov '15

01 Nov '15

Hi, I wasn’t lucky with the Tor logo, its design qualities in general, especially its performance in small sizes and its inconsistent applications (different shades of purple and green, outlines, gradients and glossy effects …). So I made a redesign. I would offer all file types needed. I hope this mailing-list is the right place to present it and discus it. Please, have a look at the PDF-file: http://www.file-upload.net/download-11010886/_logos_overview.pdf.html The whole developing system here seems decentralised and an implementation might be a bit cumbersome, but if it doesn’t exhaust me too much, I could also offer further design advice, (re-)designing app icons, making mockups for Tor websites, apps etc. and give it a consistent and professional appearance. Regards Philip

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Pluggable Transports v1 spec rewrite.
by Yawning Angel 31 Oct '15

31 Oct '15

Hello all, In an attempt to make Pluggable Transports more accessible to other people, and to have a spec that is more applicable and useful to other projects that seek to use Pluggable Transports for circumvention, I have drafted a re-write of the spec. This is not intended to alter existing behavior, but instead make it clear that the whole "Pluggable Transports" thing isn't just for Tor. Unless people have serious objections, this will replace the existing PT spec, to serve as a stop-gap while the next revision of the PT spec (that does alter behavior) is being drafted/implemented. Regards, -- Yawning Angel

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Bridge Guards (prop#188) & Bridge ORPort Reachability Tests
by isis 30 Oct '15

30 Oct '15

Hey all, I have a working implementation of proposal #188, [0] which specifies a mechanism by which tor's (rather accidental) loose-source routing feature is utilised by Bridges in order to transparently inject a Bridge Guard into all client circuits. (See #7144. [1]) Currently, I am updating the text in proposal #188 to match my implementation, and I am trying to decide what to do about the two types of Bridge ORPort reachability testing. Here's the text I've written so far to explain the issues: (In the following, "Alice" is an OP, "Bob" is a Bridge, "Guillaume" is Bob's chosen Entry Guard, and "Charlie" is a random Middle node.) > 4.4. Bridge Reachability Testing > > Currently, a Bridge's reachability is tested both by the Bridge > itself (called "self-testing") and by the BridgeAuthority. > > 4.4.1. Bridge Reachability Self-Testing > > Before a Bridge uploads its descriptors to the BridgeAuthority, it > creates a special type of testing circuit which ends at itself: > > Bob -> Guillaume -> Charlie -> Bob > > Thus, going to all this trouble to later use loose-source routing in > order to relay Alice's traffic through Guillaume (rather than > connecting directly to Charlie, as Alice intended) is diminished by > the fact that Charlie can still passively enumerate Bridges by > waiting to be asked to connect to a node which is not > contained within the consensus. > > We could get around this option by disabling self-testing for bridges > entirely, by automatically setting "AssumeReachable 1" for all Bridge > relays… although I am not sure if this is wise. > > 4.4.2. Bridge Reachability Testing by the BridgeAuthority > > After receiving Bob's descriptors, the BridgeAuthority attempts to > connect to Bob's ORPort by making a direct TLS connection to the > Bridge's advertised ORPort. > > Should we change this behaviour? One the one hand, at least this > does not enable any random OR in the entire network to enumerate > Bridges. On the other hand, any adversary who can observe packets > from the BridgeAuthority is capable of enumeration. So, my current questions are: 1. Bridges only do reachability self-testing in order to warn their operators that the Bridge (or firewall or whatever) might be misconfigured, correct? Is there any other reason (or future reason) why self-testing is important/useful? 2. How should the self-testing be changed? 2.a. First, if there aren't any other reasons for self-testing: Is Bridge reachability self-testing actually helpful to Bridge operators in practice? Don't most Bridge operators just try to connect, as a client, to their own Bridge to see if it's working correctly? (This is what I usually do, at least…) If it's not useful to most Bridge operators, can we just disable self-testing for all Bridges? (And, should we disable it only for Bridges who are using Bridge Guards, or all of Bridges regardless?) 2.b. If it is useful to people, then the best way I can think of so far to keep it, but refactor it to be safer, would be to create a circuit like: Bridge → Guard → Middle → OtherMiddle → Guard → Bridge Clearly, that circuit is just a little bit insane… but we can't do: Bridge → Guard → Middle → Guard → Bridge because the Middle would refuse to extend back to the previous node (all ORs follow this rule). Similarly, it would be stupid to do: Bridge → Guard → Middle → OtherMiddle → Bridge because, obviously, that merely shifts the problem and accomplishes nothing. But is there something smarter I could do? 3. Should we change how the BridgeAuthority tests Bridge ORPort reachability? If so, how? 4. If I'm going to refactor all of this, are there other (future) things I should take into account? For example, if self-testing is disabled for Bridges, and, due to #7349, [2] the BridgeAuthority isn't testing reachability either, then how will the BridgeAuthority know if (any of) the Bridge's PTs are reachable? (One solution might be to, in that case, have the BridgeAuthority lie and tell BridgeDB that such Bridges were reachable, letting BridgeDB do the PT reachability testing.) Please help me brainstorm a way out of this mess! [0]: https://gitweb.torproject.org/torspec.git/tree/proposals/188-bridge-guards.… [1]: https://bugs.torproject.org/7144 [2]: https://bugs.torproject.org/7349 Best Regards, -- ♥Ⓐ isis agora lovecruft _________________________________________________________ OpenPGP: 4096R/0A6A58A14B5946ABDE18E207A3ADB67A2CDB8B35 Current Keys: https://blog.patternsinthevoid.net/isis.txt

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