December 2013 - tor-dev - lists.torproject.org

Statistics on fraction of connections used uni-/bidirectionally
by Karsten Loesing 09 Dec '13

09 Dec '13

Björn, Florian, a few years back (in 2010, to be precise) we added statistics to little-t-tor reporting what fraction of connections is used uni-/bidirectionally. Quoting dir-spec.txt: "conn-bi-direct" YYYY-MM-DD HH:MM:SS (NSEC s) BELOW,READ,WRITE,BOTH NL [At most once] Number of connections, split into 10-second intervals, that are used uni-directionally or bi-directionally as observed in the NSEC seconds (usually 86400 seconds) before YYYY-MM-DD HH:MM:SS. Every 10 seconds, we determine for every connection whether we read and wrote less than a threshold of 20 KiB (BELOW), read at least 10 times more than we wrote (READ), wrote at least 10 times more than we read (WRITE), or read and wrote more than the threshold, but not 10 times more in either direction (BOTH). After classifying a connection, read and write counters are reset for the next 10-second interval. These statistics are disabled by default, but when they are enabled, relays publish them in their extra-info descriptors. And quite a few relays do that. Here's a (bad) visualization (that used to be slightly less bad when fewer relays published these statistics): https://metrics.torproject.org/performance.html#connbidirect Here's the question: Is there still value in having these statistics? I recall that they were useful in 2010, but will that still be the case in 2013? If the answer is "yes", never mind. If the answer is "no", I'd create a ticket and submit a patch to remove code parts from little-t-tor, and I'd remove the not-really-useful graph from the metrics website. Cc'ing Rob, Aaron, and Roger as the people who typically have an interest in these kinds of statistics. If other tor-dev@ people have an opinion on this, please raise your voice! All the best, Karsten

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Merge of Gitian PT build with 3.0-rc-1; next steps
by David Fifield 08 Dec '13

08 Dec '13

I recently merged the Gitian-based pluggable transports bundle build with tag tbb-3.0rc1-build1, with suprisingly little difficulty. I'd like you to take a look at what the pt branch is doing and help me decide what to do next. Some background: The ticket for building the PT bundles is https://trac.torproject.org/projects/tor/ticket/9444 The pt branch is at https://gitweb.torproject.org/user/dcf/tor-browser-bundle.git/shortlog/refs… To see what's different in the pt branch with respect to master, in an existing tor-browser-bundle.git checkout, do this: git remote add dcf https://git.torproject.org/user/dcf/tor-browser-bundle.git git fetch dcf Then, for example, git diff master...dcf/pt --stat git diff master...dcf/pt gitk master dcf/pt A recent build of 00789049873753d931fec3803c9ccae75a5c5267 is here, also containing the full complement of usual build outputs. https://people.torproject.org/~dcf/pt-bundle/3.0-rc-1-pt20131207-1/ These bundles are up to date and seem to be working well. I would be comfortable shipping them to users. I'd like your advice on how to make the pluggable transports browser part of the usual build. The diff between descriptors gitian-bundle.yml and gitian-ptbundle.yml is small; in fact I can paste it here: --- descriptors/linux/gitian-bundle.yml 2013-12-06 19:38:40.000000000 -0800 +++ descriptors/linux/gitian-ptbundle.yml 2013-12-06 19:38:40.000000000 -0800 @@ -1,3 +1,3 @@ --- -name: "bundle-linux" +name: "ptbundle-linux" suites: @@ -29,2 +29,4 @@ - "tor-linux64-gbuilt.zip" +- "pluggable-transports-linux32-gbuilt.zip" +- "pluggable-transports-linux64-gbuilt.zip" - "relativelink-src.zip" @@ -39,2 +41,4 @@ - "tbb-docs.zip" +- "pttbb-docs.zip" +- "linux-pt-torrc" script: | @@ -98,4 +102,8 @@ unzip ~/build/tor-linux$GBUILD_BITS-gbuilt.zip + unzip ~/build/pluggable-transports-linux$GBUILD_BITS-gbuilt.zip unzip ~/build/linux-skeleton.zip unzip ~/build/tbb-docs.zip + mkdir -p Docs/PluggableTransports + unzip -d Docs/PluggableTransports ~/build/pttbb-docs.zip + cat ~/build/linux-pt-torrc >> Data/Tor/torrc-defaults chmod 700 Data/Browser @@ -122,3 +130,3 @@ #mv tor-browser.exe $OUTDIR/tor-browser-linux${GBUILD_BITS}_en-US.7z-selfextract - ~/build/dtar.sh $OUTDIR/tor-browser-linux${GBUILD_BITS}-${TORBROWSER_VERSION}_en-US.tar.xz tor-browser_en-US + ~/build/dtar.sh $OUTDIR/tor-pluggable-transports-browser-linux${GBUILD_BITS}-${TORBROWSER_VERSION}_en-US.tar.xz tor-browser_en-US rm -rf tor-browser_en-US @@ -149,3 +157,3 @@ #mv tor-browser.exe $OUTDIR/tor-browser-linux${GBUILD_BITS}_$LANG.7z-selfextract - ~/build/dtar.sh $OUTDIR/tor-browser-linux${GBUILD_BITS}-${TORBROWSER_VERSION}_$LANG.tar.xz tor-browser_$LANG + ~/build/dtar.sh $OUTDIR/tor-pluggable-transports-browser-linux${GBUILD_BITS}-${TORBROWSER_VERSION}_$LANG.tar.xz tor-browser_$LANG I see a couple of options for getting rid of gitian-ptbundle.yml: 1. Add a conditional variable, something like the '[ ${TORBROWSER_VERSION::3} != "3.0" ]' in linux/gitian-firefox.yml, that controls whether a vanilla or a PT build is underway. When the variable is set, it would just do the few small changes in the diff above. 2. Build the pluggable transports bundles unconditionally, and just do all the dtars in gitian-bundle.yml twice: once for tor-browser and once for tor-pluggable-transports-browser. Either option, I think, puts us in a good place to step to a unified bundle in the future. What do you think? David Fifield

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Torbirdy - IMAP issue
by arkmd 07 Dec '13

07 Dec '13

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Accessing an email server via IMAP may leak data by saving a draft on the remote server. Using Thunderbird+Enigmail+Torbirdy. While writing a message on Thunderbird, it is automatically saved as a draft, which by default is sent to the IMAP server. So the server will be able to read that message. That's a big problem when the message should be encrypted before sent. So the email provider will be able to read sensitive data on those drafts in cleartext and the user probably won't notice. To solve this the user need to manually set the account drafts settings (in Copies & Folders) to keep drafts on Local Folders. I think Torbirdy should do it by default. This info should be added to known issues on Torbirdy wiki. I know Torbirdy developers recommend POP over IMAP, but as a mailtor.net user I don't have any other option. - -- arkmd DeepBlog | A verdade nua crua e distorcida http://xzzpowtjlobho6kd.onion/ OpenPGP Public Key: http://xzzpowtjlobho6kd.onion/arkmd.asc 4096R: 0461 DF2C B6B7 6059 7529 77E0 04CD FE83 766B 8DA6 -----BEGIN PGP SIGNATURE----- iQIcBAEBCgAGBQJSoUwEAAoJEATN/oN2a42mW/AQAI7IITFPTZEe4X2UBNS3kovK UHJIe9j/K9FA63ubGxu8TotdkIK5TvnkPP/DGDg6NrnILIx/KeK6XAWTDhv6vfgY hIBA+v+9mjAW64fQ31tTSXEVKUofKUyazN984QnVcb/Qyj297GujgrI0vdDFU0c9 KIS7z15Lk3QRx+Qtb+VboXH3ES59oRPuutTSQ+z0RyLToMmFs41BDei01WtLfy/i aLcIYTWUZb+yVmspkOuOKAe9enlGNTXeFGaR6uspA8ImedsCUYq5iySBhm5CVs0B 0sF6Mq18rXTVDF4jwoNLYqkgyANSI9IzgDbxlzgBaJwJjnN9OAeF8vJI+qkZUElS 56pVIzayyEMJXhvsqotuBYH+X+aRt2+Hw2prIxuUcRDFP3iOrupElARpqvDqYa4U IrQ/8lUl5jEnPNNJFklBwTjzHOVtxmCymEDh+zSXlIzL4WQJwYPDj1+uqwOenwO4 FCy1ADFXyMDQso3bXwPqD3VSGdYGqmMc+34vIVA28vTSFYyxiBwjHZLF16Us+uD/ sMbMGEOg+za8MSrgLVwcBAkbRG14fE50litW+bnSWl3QltGOt0rV9INKLKSGvEy4 DMCL2mc9aU9Rago1j/FJlXAOCctuFlTOS9MkCzF+iSJIoa3IxwUmnrvWwOuEuFxa zrSdjkyzMJKgnd+b+Vm4 =oF2B -----END PGP SIGNATURE-----

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InjectSOCKS
by tor＠herr-der-mails.de 06 Dec '13

06 Dec '13

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Pluggable transports meeting tomorrow (Friday 6th of December 2013)
by George Kadianakis 06 Dec '13

06 Dec '13

Greetings humans, this is an email to remind you that the regular biweekly pluggable transports meeting is going to happen tomorrow. Place is the #tor-dev IRC channel in OFTC. Time is 17:00 UTC. Cheers!

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Re: [tor-dev] (Draft) Proposal 224: Next-Generation Hidden Services in Tor
by Kang 05 Dec '13

05 Dec '13

Hello. I gave it a quick once over and these are my thoughts. I very much appreciate the ``Participants'' and ``In more detail: A menagerie of keys'' sections. I've had trouble in the past where I've been reading Tor specs and a new (or inconsistently named) key or actor is mentioned in passing. Likewise I appreciate that | was explicitly defined as concatenation, since in the current rend-spec it's left ambiguous. A few times you mention ``consensus parameters''. I assume these are values that go in the params field of the consensus, although it wasn't particularly clear (for me) until I looked it up in dir-spec. I like the ``Offline operation'' idea; that would certainly be more secure than distributing the same private key to several servers. In the hsdir_index(node) formula what exactly is ``node_identity_digest''?

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GSoC 2014
by Nicolae Andrei 03 Dec '13

03 Dec '13

Hey everyone, I would be very interested in the Google Summer of Code 2014 edition. Do you intend to apply as a mentoring organization? Moreover, do you have any projects in plan about which we could talk? I would like to involve in your ideas as soon as possible. Thank you and best regards, Andrei

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Design for an exit relay scanner: feedback appreciated
by Philipp Winter 03 Dec '13

03 Dec '13

I am working on a Python-based exit relay scanner which should detect malicious and misbehaving exits. The design should have a reasonable balance between being fast/parallel and stressing the network as little as possible. I came up with the following three steps: 1. Spawn a "parent" Tor process to get an up-to-date consensus. 2.1 For every selected exit relay, spawn a lightweight Tor process. 2.2 The consensus is copied from the "parent" process to the lightweight process' data directory. That way, the consensus has to be downloaded only once. 2.3 Every lightweight Tor process has the following configuration: --- SOCKSPort auto ControlPort 0 __DisablePredictedCircuits 1 UseEntryGuards 0 FetchServerDescriptors 0 DataDirectory <data_directory> ExitNodes <exit_relay> --- Entry guards are not used to distribute the load. Predicted circuits are disabled to prevent expensive creation of circuits which would not be used anyway. In addition, I am considering adding "EntryNodes" or "Bridge" to concentrate the first hop's load on machines under my control. 3. torsocks is then used to establish decoy connections over the respective exit relay. After that, the process is terminated. Any thoughts on how to further improve the design or ideas for a better one? Cheers, Philipp

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Orbot+Orchid redesign
by Bruce Leidl 02 Dec '13

02 Dec '13

> This makes me wonder: Would it be helpful to start compiling a big > list of things which could go wrong with a Tor implementation without > making it obviously broken? I think a checklist like that might help > people working on compatible implementations to have some idea what to > look for once you have something that interoperates. Would you have > found that useful? Would you find that useful now? Yes, for sure. I would have found that very useful because the delta between a working implementation and a secure implementation is quite large and a checklist would allow me to go down the list and at least *know* that I'm missing things. Some of these details may even be underspecified and there would be no easy way for me to find out about them. --brl

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Orbot+Orchid redesign
by Bruce Leidl 02 Dec '13

02 Dec '13

>> Any objections to this approach? Is Orchid ready for this? > > It seems like a good architecture to target. I'm not sure that the > current Orchid codebase has gotten as much review yet as it would need > before I'd be comfortable making it the default option, but an > experimental build could be a fine idea. > > (My two cents' worth; two cents not refundable) Hi, Orchid (previously called JTor) author here, I agree with Nick to be cautious about rushing out and replacing Tor with Orchid for really important projects. I believe that it works well and that it is implemented correctly and securely, but you may want to collect more opinions than just mine about that. Although Orchid is advertised as working on Android, the amount of testing on Android has been very light so far. So please start using Orchid experimentally to discover bugs and other inadequacies, but for projects that can get away with using C Tor that's probably a better plan for now. To help you decide if Orchid is appropriate for use here's a list of important things which have not (yet) been implemented: * Path bias defense * Adaptive circuit build times (also, path bias depends on this?) * Stream isolation * Optimistic data * Control protocol * Publication of hidden services (I don't understand the description of Adaptive CBT in the spec at all, so I would either need to blindly copy the implemenation from Tor (i.e circuitstats.c) or need help from the original author.) --brl

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