- tor-dev - lists.torproject.org

Requesting feedback on TorDNSd v1.1
by LETO 02 Aug '11

02 Aug '11

Could some of you be so kind to try out my latest version of TorDNSd? It works a lot like ttdnsd with some additional features: - Filters to tell TorDNSd what requests to forward directly, forward through the SOCKS proxy or reject. - Remaps to define your own query replies (Currently only supports A, MX and NS replies) - Interactive shell (tordnsd-shell.exe): config-add settings and see them in action right away, will add extra features in the future. - Accepts both UDP and TPC DNS requests, forwards both through TCP requests - Basic caching of replies (optional) The rejects are handy to for example prevent leaking .onion requests (or any request if you want) You can also find some additional information about this release on my blog ( http://leto-r.blogspot.com/2011/07/tordnsd-v11-is-out.html ) It is written in C# and has been tested by myself under mono 2.6.7 / ubuntu natty. Check the default configuration @ https://raw.github.com/LETO-R/TorDNSd/b7aa04e980ad62308d4f2fa3143700c85b537… the full list of available settings. You can either download the mono compatible bins ( https://github.com/downloads/LETO-R/TorDNSd/tordnsd-v1.1-all-bin.zip ) or the windows installer ( https://github.com/downloads/LETO-R/TorDNSd/tordnsd-v1.1-win-setup.exe ) You can find the source code of these bins @ https://github.com/LETO-R/TorDNSd/tree/b7aa04e980ad62308d4f2fa3143700c85b53… sure to get the submodules too) The sourcecode should be compilable using either MonoDevelop 2.4.2 (using the mono runtime) or Visual Studio 2010. If you do not run it as root on a non-windows system, a fatal error is printed since TorDNSd will most likely not be able to bind on port 53. Specify --no-root to skip this check. Kind of feedback I'd like of you: - What OS did you try it on? When ran using mono, what version? - Did it work? Did it require the elevated rights (root / administrator)? Did the root-checking work on non-windows systems? - Did the shell work for you? If not, what issues did you notice? Any improvements that you suggest? - Are the settings explained well enough (check tordnsd.conf)? - Is the supplied default configuration sufficient? Any filter / remaps I forgot? - Any other feedback you can think of, don't hold back! This is my first attempt at a cross-platform .NET project that contains some non-windows specific code / workarounds (mostly for the shell) so I really could use the feedback. If you do not wish to run it as your main dns resolver 'just yet', you can always test it by using dig (examples: 'dig @127.0.0.1 bla.onion' to test rejection, or 'dig @127.0.0.1 vescum.tor' to test the remap feature) All I ask is to stay constructive. If you wonder, I constantly have TorDNSd (shell) running now and have configured it as my main dns resolver as I consider it secure. Hope you find this to be true as well. - LETO

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[Patch] or/networkstatus.c
by Gisle Vanem 01 Aug '11

01 Aug '11

Hi list. In or/networkstatus.c there is a "#if 0" block inside the macro "SMARTLIST_FOREACH_JOIN". Not all compilers handle such contructs. In the prosess of making solution/projects file for "MS Visual C++ 2010 Express", I hit this problem (cl Version 16.00.30319.01). Can you please accept the following patch: diff --git a/src/or/networkstatus.c b/src/or/networkstatus.c index 2586ce6..d8d6680 100644 --- a/src/or/networkstatus.c +++ b/src/or/networkstatus.c @@ -2001,19 +2001,25 @@ routers_update_status_from_consensus_networkstatus(smartlist_t *routers, routers_sort_by_identity(routers); + /* Since not all compilers handles '#' inside macros, we use a helper-macro. */ +#if 0 + #define CHECK_ROUTER_PURPOSE() do { \ + /* We have no routerstatus for this router. Clear flags and skip it. */ \ + if (!authdir) { \ + if (router->purpose == ROUTER_PURPOSE_GENERAL) \ + router_clear_status_flags(router); \ + } \ + } while (0) +#else + #define CHECK_ROUTER_PURPOSE() +#endif + SMARTLIST_FOREACH_JOIN(ns->routerstatus_list, routerstatus_t *, rs, routers, routerinfo_t *, router, tor_memcmp(rs->identity_digest, router->cache_info.identity_digest, DIGEST_LEN), + { CHECK_ROUTER_PURPOSE(); }) { -#if 0 - /* We have no routerstatus for this router. Clear flags and skip it. */ - if (!authdir) { - if (router->purpose == ROUTER_PURPOSE_GENERAL) - router_clear_status_flags(router); - } -#endif - }) { /* We have a routerstatus for this router. */ const char *digest = router->cache_info.identity_digest; ------------------------ --gv

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Unused -v and -F options in torperf/trivsocks-client?
by David Fifield 30 Jul '11

30 Jul '11

Running "make" in torperf, I get errors about unused variables: $ make gcc -Wall -Werror -ggdb -c trivsocks-client.c trivsocks-client.c: In function ‘main’: trivsocks-client.c:452:51: error: variable ‘force’ set but not used [-Werror=unused-but-set-variable] trivsocks-client.c:452:21: error: variable ‘isVerbose’ set but not used [-Werror=unused-but-set-variable] cc1: all warnings being treated as errors make: *** [trivsocks-client.o] Error 1 The variables have to do with the -v and -F options, which appear not to do anything. This patch removes the options, but is it intentional? David Fifield

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Improving Private Browsing Mode/Tor Browser
by Georg Koppen 29 Jul '11

29 Jul '11

After reading Mike's blog post and the material contained in it (via links) I thought it would be helpful to start a discussion about it. First of all thanks for explaining the idea of improving the private browsing mode. That aim seems worthwile but I want to focus more on the needs for high anonymity systems like Tor (I am one of the JonDos people to set the records straight). Thus, first I am not sure about the relationship of the improved private browsing and the anon mode. It seems like the former is kind of precondition of the latter and the latter adds some special anon features (or just layout stuff??): "We would love to be able to ship a vastly simplified browser extension that contains only a compiled Tor binary and some minimal addon code that simply "upgrades" the user's private browsing mode into a fully functional anonymous mode." What shall the upgrade do exactly? And why having again add-ons that can probably be toggled on/off and are thus more error-prone than just having an, say, Tor anon mode? Or is this already included in the Tor anon mode but only separated in the blog post for explanatory purposes? Sticking to the blog post (one of) its central idea seems to be to isolate the identifiers and state to the top-level domain in the URL bar as "activity in Tor Browser on one site should not trivially de-anonymize their activity [i.e. the activity of Tor users, G.K.] on another site to ad networks and exits". I am wondering whether this idea really helps here at least regarding exit mixes. If one user requests google.com, mail.google.com and other Google services within the 10 minutes interval (I am simplifying here a bit) without deploying TLS the exit is still able to connect the whole activity and "sees" which services that particular user is requesting/using. Even worse, if the browser session is quite long there is a chance of recognizing that user again if she happens to have the same exit mix more than once. Thus, I do not see how that helps avoiding linkability for users that need/want strong anonymity while surfing the web. Would be good to get that explained in some detail. Or maybe I am missing a point here. Now something to the proposed behavior of the referer and window.name. It is said that they should adhere to the "same-origin policy where sites from different origins get either no referer, or a referer that is truncated to the top-level domain". Assuming I understood TorButton's Smart-Spoofing option properly: Why is it not applied to the referer/window.name anymore? In other words: Why is the referer (and window.name) not kept if the user surfs within one domain (let's say from example.com to foo.example.com and then to foo.bar.example.com)? Before we implemented almost the same algorithm than Torbutton's smart-spoof algo in our own extension a while ago we had some compatibility issues (I remember yahoo.com that needed to have the referer untouched while surfing within the domain) that got fixed by it and never popped up again. Why stepping back? The idea "sites should also be allowed to request an exemption to this rule on a per-site basis using an html attribute, which could trigger a chrome permissions request, or simply be granted automatically (on the assumption that they could just URL smuggle the data)" seems rather awkward and not a good solution to a problem that is not really one. One final point: Leaving my previous section aside: Why is the referer and window.name not treated in the same way as cookies and others in the proposal. Why having two different policies for identifiers? I am not sure whether there could emerge some attacks out of that distinction but my feeling tells me that there should ideally be just one policy that governs all those identifiers. At least it would probably be easier to implement and to audit them. Georg

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Report from the "Tor ecosystem" BoF at DebConf 11
by Jérémy Bobbio 28 Jul '11

28 Jul '11

Hi! Here is a report from DebConf 11, the annual conference of the Debian project. We had the opportunity to hold a "Tor ecosystem" BoF. It was short (we had only 45 minutes), but productive from my perspective. Here's an (obviously partial) report. A lot more people showed up (± 25) than we expected for a pure work meeting, so there is definitely an interest in having Tor and its ecosystem working well in Debian. Among the attendees we had: * Peter Palfrader, maintainer of the 'tor' package, * Ulises Vitulli, (co-)maintainer of 'vidalia', 'tor-arm', 'python-torctl', 'torchat', * Jérémy Bobbio, maintainer of 'torbutton', * intrigeri and bertagaz, developers of Tails (which is a live system based on Debian). A summary follows from some notes and memory. Feel free to correct me if you feel that things happened differently. New upstream packaging policy ============================= We took some time to discuss the changes to the packaging policy that were proposed by Andrew Lewman last June. See <https://lists.torproject.org/pipermail/tor-dev/2011-June/002780.html> Quoting the relevant part: GNU/Linux (deb and rpm) 1. tor-client. The same TBB we ship today. 2. tor-relay. Create tor-relay.(deb|rpm) that includes geoipdb and a pre-configured torrc that is for a non-exit relay. 3. tor-exit-relay. Create tor-exit-relay.(deb|rpm) that includes geoipdb and a pre-configured torrc that is for an exit relay. 4. tor-bridge. Create tor-bridge.(deb|rpm) that includes geoipdb and a pre-configured torrc that is for a bridge. The 'tor' source package in Debian already builds a binary package called 'tor-geoipdb' which contains GeoIP information. We have not even discussed about changing, as it is how it is supposed to be in Debian (pure data package as separate, architecture-independent packages). The proposed 'tor-client' and TBB in general was discussed later. For the rest, the hard part of the discussion also revolved around defining who are target users of these packages. Pure desktop users? People that can fiddle with a command-line and edit a configuration file? Experienced sysadmins? Having 3 different "configuration" packages for relays, exit-relays and bridges is something that could be done in Debian. But we had a rough consensus that it would actually complicate things for most Debian users. For bridges, pure desktop users would probably benefit from a better integration with Vidalia; so that made us rule out the need for a dedicated 'tor-bridge' package. Which left us with the "relay" and "exit relay" use cases and it looked like those could be better adressed by either a debconf question, or by some examples better integrated. Integration with other software, derivatives and custom distributions ===================================================================== While discussing how we could actually make it easier to setup relays, we got back to the lack of a way to source extra configuration files in `torrc`. We outlined some benefits that would have a `/etc/tor/torrc.d` directory full of configuration snippets: * The 'tor' package will not (or less) need patches to change the default settings. * It would make it much easier to implement example setups (relays, exit relays, bridges) either through a debconf question or through a system script like 'tor-setup-relay'. * Tails developers will only need to drop a very small extra configuration file instead of having to rewrite the whole, which should ease development and reviewing. * Other packages which need a hidden service to work (e.g. 'onioncat') would be able to create it automatically by installing the proper configuration snippet. That would enable them to work right after being installed. Feature request: https://trac.torproject.org/projects/tor/ticket/2863 Control of the system-wide 'tor' daemon ======================================= We finally have (currently in 'experimental') an easy way for applications to control the system-wide 'tor' daemon: the ControlSocket option is on by default. Vidalia, ARM and others now only require users to be in the system 'debian-tor' group to be able to control Tor. We did not have the time to properly discuss if, and how, we offer an easy way to add users to this group. Tor Browser Bundle (e.g tor-client) =================================== There is an incentive to have something as close as the Tor Browser Bundle in Debian. Otherwise, desktop users on Debian get a smaller anonymity set (such strong partitioning already happened in the past, see <http://bugs.debian.org/595375>). The main issue is the Tor fork of Firefox. There are a few possibilities on how it can be handled within Debian. Summary: this is doable, but requires a lot of work, and the cooperation of quite a few different parties. One other thing that TBB is doing is to start its own instance of Tor. We agreed that it was a behaviour that would be quite desirable to have. It will make setup even more easier and it might limit users exposure when they are not using Tor. In order to achieve that, we need either to make the 'tor' package not start Tor after being installed or we need a way have the `tor` binary without the rest of the daemon infrastructure (e.g initscript). The former will probably be quite confusing to sysadmins, so we agreed on splitting out the daemon binary from the current 'tor' package to a new 'tor-bin' package. How TorBrowser could get in Debian? =================================== Having a full separate source package for TorBrowser is not possible due to Debian Policy 4.13. But there are still other options, all having their shortcomings: 1. Make the 'iceweasel' source package (that's how Firefox is called in Debian due to trademark issues) produce an extra 'tor-browser' binary package. Issues: - Mike Hommey (iceweasel maintainer) stated clearly that he did not want to maintain the Tor patches. But we can probably settle on a policy like "if it does not build, just drop it". The removal of a binary package does not trigger NEW queue processing. It is also not triggered if the same binary packages returns before two weeks. - Double (?) the build time of 'iceweasel' which is already huge. Security team will not be happy, and it's going to be harder to actually maintain the TorBrowser side of things. Pros: until the patches do not apply anymore, it'll be less maintainance from our side. 2. Make the 'iceweasel' source package produce an extra binary package (e.g 'iceweasel-src') that will contain the full Iceweasel source. Create a 'tor-browser' package that Build-Depends on the former. Issues: - 'iceweasel' is a pretty fast moving target. This will need us to follow its uploads quite closely to ask for binNMU or to upload updated versions quickly. - The security team will have two packages to track instead of one. They might not like it at all. Pros: much easier for Mike Hommey and we are autonomous to upload the 'tor-browser' package if changes are only needed there. Looks like the latter is probably better. But it definitely needs to be checked with all parties involved first. For browser extensions curretly shipped with TBB, Debian already has 'torbutton' and 'noscript'. But we miss 'httpseverwhere' (#591579) and 'betterprivacy'. There are a few open issues that still need to be figured out: * TorBrowser should create dedicated profiles in the user home directories, * How can default values be set? Do we need 'locked down' preferences? * How should we handle other system-wide extensions? Active like for the main Iceweasel, totally ignored, or disabled by default? * If Debian ships the TorBrowser, should we prevent Torbutton from appearing in the usual Iceweasel? This will require a lot of work for the initial bootstrap and a decent amount of work for the daily maintainance after that. But it looked worthwhile anyhow… Cheers, -- Jérémy Bobbio .''`. lunar(a)debian.org : :Ⓐ : # apt-get install anarchism `. `'` `-

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New mailing list for wiki changes
by Karsten Loesing 25 Jul '11

25 Jul '11

Hi everyone, yesterday we found that a few people run their own rss-to-email service to be notified of wiki changes. We decided that it's easier to set up a new mailing list that has all the wiki changes and that everyone can subscribe to. If you're interested in learning when something in the wiki changed, subscribe to: https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-wiki-changes (And if you have suggestions to make the r2e output more useful, please say so. The current configuration is simply 'r2e add "https://trac.torproject.org/projects/tor/timeline?wiki=on&max=50&daysback=2…" tor-wiki-changes(a)lists.torproject.org'.) Best, Karsten

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New Paper: Cloud-based Onion Routing
by Nick Jones 15 Jul '11

15 Jul '11

Hi All, I'm a graduate student at Princeton, and our research group has recently submitted a paper proposing a design for cloud based onion routing. The goal of our research is to securely perform onion routing on cloud based infrastructure (like Amazon EC2 and Rackspace) while allowing users to retain the same (or almost the same) privacy as when using Tor. We distribute trust across multiple cloud providers, and use Chaum's e-cash for payment and access control. Additionally, we hope that the elasticity of cloud infrastructure will make cloud based OR more censorship resistant than current systems. This project is still in a relatively early stage, and we would love to get feedback from the Tor community. We would welcome any comments/questions/criticisms. Our project's website is available at: http://sns.cs.princeton.edu/projects/cor/ A direct link to our paper is here: http://www.cs.princeton.edu/~najones/publications/cor-foci11.pdf Our abstract: Internet censorship and surveillance have made anonymity tools increasingly critical for free and open Internet access. Tor, and its associated ecosystem of vol- unteer traffic relays, provides one of the most secure and widely-available means for achieving Internet anonymity today. Unfortunately, Tor has limitations, including poor performance, inadequate capacity, and a susceptibility to wholesale blocking. Rather than utilizing a large number of volunteers (as Tor does), we propose mov- ing onion-routing services to the “cloud” to leverage the large capacities, robust connectivity, and economies of scale inherent to commercial datacenters. This paper de- scribes Cloud-based Onion Routing (COR), which builds onion-routed tunnels over multiple anonymity service providers and through multiple cloud hosting providers, dividing trust while forcing censors to incur large collat- eral damage. We discuss the new security policies and mechanisms needed for such a provider-based ecosys- tem, and present some preliminary benchmarks. At to- day’s prices, a user could gain fast, anonymous network access through COR for only pennies per day. Thanks! Nick Jones

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Re: [tor-dev] CPU utilization for relay
by swsnyder＠snydernet.net 15 Jul '11

15 Jul '11

Mike Perry wrote: >Thus spake swsnyder at snydernet.net (swsnyder at snydernet.net) > >> FYI, this is a profile of my Tor v0.2.2.30-rc relay, taken in a 10-minute sampling: >> >> CPU: CPU with timer interrupt, speed 0 MHz (estimated) >> Profiling through timer interrupt >> samples % linenr info symbol name >> 3126 29.7290 cast-586.s:9 CAST_encrypt > >Can you attach gdb to your relay and set a breakpoint for >CAST_encrypt? We have no idea why this function should be called at >all (unless it is for something like reading keyfiles off disk?) let >alone dominate your profile output. I didn't break on CAST_encrypt() either in a running process or in tor started from a gdb command line. Either way, I could set a breakpoint on the symbol but never actually got there. I think the symbols were screwed-up from building Tor with GCC's Profile Guided Optimization. When I built the same code without PGO I get this from another 10-minute run: CPU: CPU with timer interrupt, speed 0 MHz (estimated) Profiling through timer interrupt samples % linenr info symbol name 2386 58.6241 x86-mont.s:8 bn_mul_mont 262 6.4373 aes-586.s:269 _sse_AES_encrypt_compact 207 5.0860 sha1-586.s:8 sha1_block_data_order 199 4.8894 aes-586.s:424 _x86_AES_encrypt 189 4.6437 aes-586.s:1610 _x86_AES_decrypt 55 1.3514 aes.c:329 aes_crypt_inplace 48 1.1794 di_ops.c:97 tor_memeq Breakpoints *do* hit on bn_mul_mont(). I assume the reduced number of samples is a result of only having half as many active connection as the prior profiling run. Thanks for the reply.

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Re: [tor-dev] [tor-relays] CPU utilization for relay
by Mike Perry 15 Jul '11

15 Jul '11

Thus spake swsnyder(a)snydernet.net (swsnyder(a)snydernet.net) > FYI, this is a profile of my Tor v0.2.2.30-rc relay, taken in a 10-minute sampling: > > CPU: CPU with timer interrupt, speed 0 MHz (estimated) > Profiling through timer interrupt > samples % linenr info symbol name > 3126 29.7290 cast-586.s:9 CAST_encrypt Can you attach gdb to your relay and set a breakpoint for CAST_encrypt? We have no idea why this function should be called at all (unless it is for something like reading keyfiles off disk?) let alone dominate your profile output. gdb -p <tor_pid> (gdb) break CAST_encrypt (gdb) cont You may need to stick a 'file /usr/bin/tor' or similar in there. If you get no hits, try to do it on startup: gdb /usr/bin/tor (gdb) break CAST_encrypt Function "CAST_encrypt" not defined. Make breakpoint pending on future shared library load? (y or [n]) y (gdb) run [<tor args>] If you get any hits, run 'backtrace' and give us the output. You may need to install some debuginfo packages, but gdb should tell you this if so. If anyone playing along at home gets any hits on either of these breakpoints, let us know. > 1677 15.9486 sha256-586.s:8 sha256_block_data_order > 1149 10.9272 aes-586.s:424 _x86_AES_encrypt > 844 8.0266 sha1-586.s:8 sha1_block_data_order > 273 2.5963 crypto.c:1649 crypto_digest_get_digest > 221 2.1018 md32_common.h:283 SHA1_Update > 182 1.7309 encode.c:190 EVP_EncodeBlock > 171 1.6262 OpenBSD_malloc_Linux.c:1793 ifree > 136 1.2934 cast-586.s:379 CAST_decrypt > 130 1.2363 md32_common.h:348 SHA1_Final > 127 1.2078 obj_lib.c:66 OBJ_dup > 122 1.1602 memarea.c:221 memarea_alloc > 110 1.0461 aes-586.s:1610 _x86_AES_decrypt > > After running for 14 hours, the Tor relay has consumed 1.6% of CPU time. It is now using 45MB of RAM, servicing 112 active connections. > > According to http://torstatus.blutmagie.de my Max/Burst/Observed (Bps) bandwidth is: > > 153600 / 307200 / 127170 > > Environment: > > CPU: Pentium-M (Dothan) @ 1.80 GHz > RAM: 1.0 GB DDR1 > Net: Fast Ethernet connected to a Surfboard cable modem > > CentOS v5.6 > Tor v0.2.2.30-rc > libevent 2.0.12-stable > openssl 1.0.0d > zlib 1.2.5 > glibc 2.5-58 > > Just another data point. > > > _______________________________________________ > tor-relays mailing list > tor-relays(a)lists.torproject.org > https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays -- Mike Perry Mad Computer Scientist fscked.org evil labs

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Nick's planned schedule for Tor 0.2.3.x development
by Nick Mathewson 14 Jul '11

14 Jul '11

Hi, all! I'll try to avoid a long-winded mail and instead cut to the chase: I want Tor releases to come out more frequently, and I'm going to plan a release schedule for 0.2.3 to make sure it happens. It's July 2011 now; I want to get 0.2.3.x released in early 2012. To that end, I'm going to declare the following tentative and somewhat arbitrary schedule: December 1, 2011: Big feature freeze. No new features that "feel big" to me get merged into 0.2.3.x after this date, barring exceptional circumstances[*]. January 6, 2012: Feature freeze. Barring exceptional circumstances, no new features get merged to 0.2.3.x after this date, barring exceptional circumstances[*]. Fixes for non-regression bugs (that is, those that also existed in 0.2.2.x) may also get deferred if they aren't too severe. Some time between Jan 6 and Jan 30: we fork off a maint-0.2.3 branch and have master become 0.2.4. When it's ready, 2012: We release 0.2.3.x-rc, see how long everything took us, and adjust our plans or 0.2.4.x. Note that the deadlines above are _merge_ freezes, not _submission_ freezes. If you give me a big patch on Dec 1, and it needs more review or revision than can get done that day, then it needs to wait for 0.2.4. Obviously, this is still up for discussion. But please remember about the bikeshed. Also, please keep the following in mind: * Delaying a release in order to merge "one more feature" means that every *other* feature in the release gets delayed so that the "one more feature" can hit stable earlier. * If we can actually get releases out on a 7-9 month schedule (or better), the impact of making a feature wait for the next release becomes less severe than it's been in the past. [*] Let's not waste time trying in advance to enumerate exceptional circumstances. yrs, -- Nick

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