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volunteer.html     4) 

en/volunteer.wml   5) #include "head.wmi" TITLE="Tor: Volunteer"

volunteer.html     6) 
volunteer.html     7) <div class="main-column">
volunteer.html     8) 
volunteer.html     9) <!-- PUT CONTENT AFTER THIS TAG -->

en/volunteer.wml  10) <h2>A few things everyone can do now:</h2>

volunteer.html    11) <ol>

en/volunteer.wml  12) <li>Please consider <a href="<page docs/tor-doc-relay>">running
en/volunteer.wml  13) a relay</a> to help the Tor network grow.</li>
en/volunteer.wml  14) <li>Tell your friends! Get them to run relays. Get them to run hidden

volunteer.html    15) services. Get them to tell their friends.</li>

en/volunteer.wml  16) <li>If you like Tor's goals, please <a href="<page donate>">take a moment
en/volunteer.wml  17) to donate to support further Tor development</a>. We're also looking
en/volunteer.wml  18) for more sponsors &mdash; if you know any companies, NGOs, agencies,
en/volunteer.wml  19) or other organizations that want anonymity / privacy / communications
en/volunteer.wml  20) security, let them know about us.</li>
en/volunteer.wml  21) <li>We're looking for more <a href="<page torusers>">good examples of Tor
en/volunteer.wml  22) users and Tor use cases</a>. If you use Tor for a scenario or purpose not
en/volunteer.wml  23) yet described on that page, and you're comfortable sharing it with us,
en/volunteer.wml  24) we'd love to hear from you.</li>

volunteer.html    25) </ol>
volunteer.html    26) 

en/volunteer.wml  27) <a id="Usability"></a>

en/volunteer.wml  28) <h2><a class="anchor" href="#Usability">Supporting Applications</a></h2>

volunteer.html    29) <ol>

en/volunteer.wml  30) <li>We need more good ways to intercept DNS requests so they don't "leak" their

en/volunteer.wml  31) request to a local observer while we're trying to be anonymous. (This
en/volunteer.wml  32) happens because the application does the DNS resolve before going to
en/volunteer.wml  33) the SOCKS proxy.)</li>

en/volunteer.wml  34) <li>Tsocks/dsocks items:

en/volunteer.wml  35) <ul>
en/volunteer.wml  36) <li>We need to <a

en/volunteer.wml  37) href="https://wiki.torproject.org/noreply/TheOnionRouter/TSocksPatches">apply

en/volunteer.wml  38) all our tsocks patches</a> and maintain a new fork. We'll host it if
en/volunteer.wml  39) you want.</li>
en/volunteer.wml  40) <li>We should patch Dug Song's "dsocks" program to use Tor's
en/volunteer.wml  41) <i>mapaddress</i> commands from the controller interface, so we
en/volunteer.wml  42) don't waste a whole round-trip inside Tor doing the resolve before
en/volunteer.wml  43) connecting.</li>
en/volunteer.wml  44) <li>We need to make our <i>torify</i> script detect which of tsocks or
en/volunteer.wml  45) dsocks is installed, and call them appropriately. This probably means
en/volunteer.wml  46) unifying their interfaces, and might involve sharing code between them
en/volunteer.wml  47) or discarding one entirely.</li>
en/volunteer.wml  48) </ul>

en/volunteer.wml  49) </li>

en/volunteer.wml  50) <li>People running relays tell us they want to have one BandwidthRate

en/volunteer.wml  51) during some part of the day, and a different BandwidthRate at other
en/volunteer.wml  52) parts of the day. Rather than coding this inside Tor, we should have a
en/volunteer.wml  53) little script that speaks via the <a href="<page gui/index>">Tor
en/volunteer.wml  54) Controller Interface</a>, and does a setconf to change the bandwidth

en/volunteer.wml  55) rate. There is one for Unix and Mac already (it uses bash and cron),

en/volunteer.wml  56) but Windows users still need a solution.

en/volunteer.wml  57) </li>

en/volunteer.wml  58) <li>Tor can <a

en/volunteer.wml  59) href="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#ChooseEntryExit">exit

en/volunteer.wml  60) the Tor network from a particular exit node</a>, but we should be able
en/volunteer.wml  61) to specify just a country and have something automatically pick. The
en/volunteer.wml  62) best bet is to fetch Blossom's directory also, and run a local Blossom
en/volunteer.wml  63) client that fetches this directory securely (via Tor and checking its
en/volunteer.wml  64) signature), intercepts <tt>.country.blossom</tt> hostnames, and does
en/volunteer.wml  65) the right thing.</li>

volunteer.html    66) <li>Speaking of geolocation data, somebody should draw a map of the Earth

en/volunteer.wml  67) with a pin-point for each Tor relay. Bonus points if it updates as the

en/volunteer.wml  68) network grows and changes. Unfortunately, the easy ways to do this involve
en/volunteer.wml  69) sending all the data to Google and having them draw the map for you. How
en/volunteer.wml  70) much does this impact privacy, and do we have any other good options?</li>

volunteer.html    71) </ol>
volunteer.html    72) 

en/volunteer.wml  73) <a id="Documentation"></a>
en/volunteer.wml  74) <h2><a class="anchor" href="#Documentation">Documentation</a></h2>

volunteer.html    75) <ol>

en/volunteer.wml  76) <li>Please help Matt Edman with the documentation and how-tos for his

en/volunteer.wml  77) Tor controller,
en/volunteer.wml  78) <a href="http://vidalia-project.net/">Vidalia</a>.</li>

en/volunteer.wml  79) <li>Evaluate and document

en/volunteer.wml  80) <a href="https://wiki.torproject.org/wiki/TheOnionRouter/TorifyHOWTO">our

en/volunteer.wml  81) list of programs</a> that can be configured to use Tor.</li>

volunteer.html    82) <li>We need better documentation for dynamically intercepting

en/volunteer.wml  83) connections and sending them through Tor. tsocks (Linux), dsocks (BSD),

en/volunteer.wml  84) and freecap (Windows) seem to be good candidates, as would better
en/volunteer.wml  85) use of our new TransPort feature.</li>

en/volunteer.wml  86) <li>We have a huge list of <a href="https://wiki.torproject.org/noreply/TheOnionRouter/SupportPrograms">potentially useful

volunteer.html    87) programs that interface to Tor</a>. Which ones are useful in which
volunteer.html    88) situations? Please help us test them out and document your results.</li>

en/volunteer.wml  89) <li>Help translate the web page and documentation into other
en/volunteer.wml  90) languages. See the <a href="<page translation>">translation

en/volunteer.wml  91) guidelines</a> if you want to help out. We especially need Arabic or
en/volunteer.wml  92) Farsi translations, for the many Tor users in censored areas.</li>

volunteer.html    93) </ol>
volunteer.html    94) 

en/volunteer.wml  95) <a id="Coding"></a>

en/volunteer.wml  96) <a id="Summer"></a>
en/volunteer.wml  97) <a id="Projects"></a>

en/volunteer.wml  98) <h2><a class="anchor" href="#Projects">Good Coding Projects</a></h2>

en/volunteer.wml  99) 
en/volunteer.wml 100) <p>

en/volunteer.wml 101) Here is a list of ideas that were proposed for the <a href="<page gsoc>">Google Summer of Code 2008</a>
en/volunteer.wml 102) but have not been put into practice. Some of the <a href="<svnsandbox>doc/spec/proposals/">current proposals</a> 
en/volunteer.wml 103) might also be short on developers. If you think you can help out, <a href="<page contact>"> let us know!</a> 

en/volunteer.wml 104) </p>
en/volunteer.wml 105) 

en/volunteer.wml 106) <ol>
en/volunteer.wml 107) 

en/volunteer.wml 108) <li>

en/volunteer.wml 109) <b>Tor Node Scanner improvements</b>

en/volunteer.wml 110) <br />

en/volunteer.wml 111) Similar to the SoaT exit scanner (or perhaps even during exit scanning),

en/volunteer.wml 112) statistics can be gathered about the reliability of nodes. Nodes that
en/volunteer.wml 113) fail too high a percentage of their circuits should not be given
en/volunteer.wml 114) Guard status. Perhaps they should have their reported bandwidth
en/volunteer.wml 115) penalized by some ratio as well, or just get marked as Invalid. In
en/volunteer.wml 116) addition, nodes that exhibit a very low average stream capacity but
en/volunteer.wml 117) advertise a very high node bandwidth can also be marked as Invalid.
en/volunteer.wml 118) Much of this statistics gathering is already done, it just needs to be
en/volunteer.wml 119) transformed into something that can be reported to the Directory
en/volunteer.wml 120) Authorities to blacklist/penalize nodes in such a way that clients
en/volunteer.wml 121) will listen.

en/volunteer.wml 122) <br />

en/volunteer.wml 123) In addition, these same statistics can be gathered about the traffic
en/volunteer.wml 124) through a node. Events can be added to the <a

en/volunteer.wml 125) href="https://svn.torproject.org/svn/torctl/trunk/doc/howto.txt">Tor Control

en/volunteer.wml 126) Protocol</a> to
en/volunteer.wml 127) report if a circuit extend attempt through the node succeeds or fails, and
en/volunteer.wml 128) passive statistics can be gathered on both bandwidth and reliability
en/volunteer.wml 129) of other nodes via a node-based monitor using these events. Such a
en/volunteer.wml 130) scanner would also report information on oddly-behaving nodes to
en/volunteer.wml 131) the Directory Authorities, but a communication channel for this
en/volunteer.wml 132) currently does not exist and would need to be developed as well.
en/volunteer.wml 133) </li>
en/volunteer.wml 134) 
en/volunteer.wml 135) <li>
en/volunteer.wml 136) <b>Help track the overall Tor Network status</b>

en/volunteer.wml 137) <br />

en/volunteer.wml 138) It would be great to set up an automated system for tracking network
en/volunteer.wml 139) health over time, graphing it, etc. Part of this project would involve
en/volunteer.wml 140) inventing better metrics for assessing network health and growth. Is the
en/volunteer.wml 141) average uptime of the network increasing? How many relays are qualifying
en/volunteer.wml 142) for Guard status this month compared to last month? What's the turnover
en/volunteer.wml 143) in terms of new relays showing up and relays shutting off? Periodically
en/volunteer.wml 144) people collect brief snapshots, but where it gets really interesting is
en/volunteer.wml 145) when we start tracking data points over time.
en/volunteer.wml 146) <br />
en/volunteer.wml 147) Data could be collected from the "Tor Node Scanner" item above, from
en/volunteer.wml 148) the server descriptors that each relay publishes, and from other
en/volunteer.wml 149) sources. Results over time could be integrated into one of the <a
en/volunteer.wml 150) href="https://torstatus.blutmagie.de/">Tor Status</a> web pages, or be
en/volunteer.wml 151) kept separate. Speaking of the Tor Status pages, take a look at Roger's
en/volunteer.wml 152) <a href="http://archives.seul.org/or/talk/Jan-2008/msg00300.html">Tor
en/volunteer.wml 153) Status wish list</a>.
en/volunteer.wml 154) </li>
en/volunteer.wml 155) 
en/volunteer.wml 156) <li>
en/volunteer.wml 157) <b>Better Debian/Ubuntu Packaging for Tor+Vidalia</b>

en/volunteer.wml 158) <br />
en/volunteer.wml 159) Vidalia currently doesn't play nicely on Debian and Ubuntu with the
en/volunteer.wml 160) default Tor packages. The current Tor packages automatically start Tor
en/volunteer.wml 161) as a daemon running as the debian-tor user and (sensibly) do not have a

en/volunteer.wml 162) <a href="<svnsandbox>doc/spec/control-spec.txt">ControlPort</a> defined
en/volunteer.wml 163) in the default torrc. Consequently, Vidalia will try

en/volunteer.wml 164) to start its own Tor process since it could not connect to the existing

en/volunteer.wml 165) Tor, and Vidalia's Tor process will then exit with an error message

en/volunteer.wml 166) the user likely doesn't understand since Tor cannot bind its listening

en/volunteer.wml 167) ports — they're already in use by the original Tor daemon.

en/volunteer.wml 168) <br />
en/volunteer.wml 169) The current solution involves either telling the user to stop the
en/volunteer.wml 170) existing Tor daemon and let Vidalia start its own Tor process, or
en/volunteer.wml 171) explaining to the user how to set a control port and password in their
en/volunteer.wml 172) torrc. A better solution on Debian would be to use Tor's ControlSocket,
en/volunteer.wml 173) which allows Vidalia to talk to Tor via a Unix domain socket, and could
en/volunteer.wml 174) possibly be enabled by default in Tor's Debian packages. Vidalia can

en/volunteer.wml 175) then authenticate to Tor using filesystem-based (cookie) authentication
en/volunteer.wml 176) if the user running Vidalia is also in the debian-tor group.

en/volunteer.wml 177) <br />
en/volunteer.wml 178) This project will first involve adding support for Tor's ControlSocket
en/volunteer.wml 179) to Vidalia. The student will then develop and test Debian and Ubuntu
en/volunteer.wml 180) packages for Vidalia that conform to Debian's packaging standards and

en/volunteer.wml 181) make sure they work well with the existing Tor packages. We can also

en/volunteer.wml 182) set up an apt repository to host the new Vidalia packages.
en/volunteer.wml 183) <br />

en/volunteer.wml 184) The next challenge would be to find an intuitive usable way for Vidalia
en/volunteer.wml 185) to be able to change Tor's configuration (torrc) even though it is
en/volunteer.wml 186) located in <code>/etc/tor/torrc</code> and thus immutable. The best
en/volunteer.wml 187) idea we've come up with so far is to feed Tor a new configuration via
en/volunteer.wml 188) the ControlSocket when Vidalia starts, but that's bad because Tor starts

en/volunteer.wml 189) each boot with a different configuration than the user wants. The second
en/volunteer.wml 190) best idea

en/volunteer.wml 191) we've come up with is for Vidalia to write out a temporary torrc file
en/volunteer.wml 192) and ask the user to manually move it to <code>/etc/tor/torrc</code>,
en/volunteer.wml 193) but that's bad because users shouldn't have to mess with files directly.
en/volunteer.wml 194) <br />

en/volunteer.wml 195) A person undertaking this project should have prior knowledge of

en/volunteer.wml 196) Debian package management and some C++ development experience. Previous
en/volunteer.wml 197) experience with Qt is helpful, but not required.
en/volunteer.wml 198) </li>
en/volunteer.wml 199) 

en/volunteer.wml 200) <li>
en/volunteer.wml 201) <b>Improving Tor's ability to resist censorship</b>
en/volunteer.wml 202) <br />
en/volunteer.wml 203) The Tor 0.2.0.x series makes <a
en/volunteer.wml 204) href="<svnsandbox>doc/design-paper/blocking.html">significant
en/volunteer.wml 205) improvements</a> in resisting national and organizational censorship.
en/volunteer.wml 206) But Tor still needs better mechanisms for some parts of its
en/volunteer.wml 207) anti-censorship design.  For example, current Tors can only listen on a
en/volunteer.wml 208) single address/port combination at a time.  There's
en/volunteer.wml 209) <a href="<svnsandbox>doc/spec/proposals/118-multiple-orports.txt">a
en/volunteer.wml 210) proposal to address this limitation</a> and allow clients to connect
en/volunteer.wml 211) to any given Tor on multiple addresses and ports, but it needs more
en/volunteer.wml 212) work.  Another anti-censorship project (far more difficult) is to try
en/volunteer.wml 213) to make Tor more scanning-resistant.  Right now, an adversary can identify
en/volunteer.wml 214) <a href="<svnsandbox>doc/spec/proposals/125-bridges.txt">Tor bridges</a>
en/volunteer.wml 215) just by trying to connect to them, following the Tor protocol, and
en/volunteer.wml 216) seeing if they respond.  To solve this, bridges could
en/volunteer.wml 217) <a href="<svnsandbox>doc/design-paper/blocking.html#tth_sEc9.3">act like
en/volunteer.wml 218) webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
en/volunteer.wml 219) and not act like bridges until the user provides a bridge-specific key.
en/volunteer.wml 220) <br />
en/volunteer.wml 221) This project involves a lot of research and design. One of the big
en/volunteer.wml 222) challenges will be identifying and crafting approaches that can still
en/volunteer.wml 223) resist an adversary even after the adversary knows the design, and
en/volunteer.wml 224) then trading off censorship resistance with usability and robustness.
en/volunteer.wml 225) </li>
en/volunteer.wml 226) 
en/volunteer.wml 227) <li>
en/volunteer.wml 228) <b>Tor/Polipo/Vidalia Auto-Update Framework</b>
en/volunteer.wml 229) <br />
en/volunteer.wml 230) We're in need of a good authenticated-update framework.
en/volunteer.wml 231) Vidalia already has the ability to notice when the user is running an
en/volunteer.wml 232) outdated or unrecommended version of Tor, using signed statements inside
en/volunteer.wml 233) the Tor directory information. Currently, Vidalia simply pops
en/volunteer.wml 234) up a little message box that lets the user know they should manually
en/volunteer.wml 235) upgrade. The goal of this project would be to extend Vidalia with the
en/volunteer.wml 236) ability to also fetch and install the updated Tor software for the
en/volunteer.wml 237) user. We should do the fetches via Tor when possible, but also fall back
en/volunteer.wml 238) to direct fetches in a smart way. Time permitting, we would also like
en/volunteer.wml 239) to be able to update other
en/volunteer.wml 240) applications included in the bundled installers, such as Polipo and
en/volunteer.wml 241) Vidalia itself.
en/volunteer.wml 242) <br />
en/volunteer.wml 243) To complete this project, the student will first need to first investigate
en/volunteer.wml 244) the existing auto-update frameworks (e.g., Sparkle on OS X) to evaluate
en/volunteer.wml 245) their strengths, weaknesses, security properties, and ability to be
en/volunteer.wml 246) integrated into Vidalia. If none are found to be suitable, the student
en/volunteer.wml 247) will design their own auto-update framework, document the design, and
en/volunteer.wml 248) then discuss the design with other developers to assess any security
en/volunteer.wml 249) issues. The student will then implement their framework (or integrate
en/volunteer.wml 250) an existing one) and test it.
en/volunteer.wml 251) <br />

en/volunteer.wml 252) A person undertaking this project should have good C++ development
en/volunteer.wml 253) experience. Previous experience with Qt is helpful, but not required. One
en/volunteer.wml 254) should also have a good understanding of common security

en/volunteer.wml 255) practices, such as package signature verification. Good writing ability
en/volunteer.wml 256) is also important for this project, since a vital step of the project

en/volunteer.wml 257) will be producing a design document to review and discuss
en/volunteer.wml 258) with others prior to implementation.

en/volunteer.wml 259) </li>
en/volunteer.wml 260) 
en/volunteer.wml 261) <li>
en/volunteer.wml 262) <b>An Improved and More Usable Network Map in Vidalia</b>
en/volunteer.wml 263) <br />
en/volunteer.wml 264) One of Vidalia's existing features is a network map that shows the user
en/volunteer.wml 265) the approximate geographic location of relays in the Tor network and
en/volunteer.wml 266) plots the paths the user's traffic takes as it is tunneled through the
en/volunteer.wml 267) Tor network. The map is currently not very interactive and has rather
en/volunteer.wml 268) poor graphics. Instead, we would like to leverage KDE's Marble widget
en/volunteer.wml 269) that gives us a better quality map and enables improved interactivity,
en/volunteer.wml 270) such as allowing the user to click on individual relays or circuits to
en/volunteer.wml 271) display additional information. We might also consider adding the ability
en/volunteer.wml 272) for users to click on a particular relay or a country containing one or
en/volunteer.wml 273) more Tor exit relays and say, "I want my connections to foo.com to exit
en/volunteer.wml 274) from here."
en/volunteer.wml 275) <br />

en/volunteer.wml 276) This project will first involve getting familiar with Vidalia
en/volunteer.wml 277) and the Marble widget's API. One will then integrate the widget

en/volunteer.wml 278) into Vidalia and customize Marble to be better suited for our application,
en/volunteer.wml 279) such as making circuits clickable, storing cached map data in Vidalia's
en/volunteer.wml 280) own data directory, and customizing some of the widget's dialogs.
en/volunteer.wml 281) <br />

en/volunteer.wml 282) A person undertaking this project should have good C++ development

en/volunteer.wml 283) experience. Previous experience with Qt and CMake is helpful, but not
en/volunteer.wml 284) required.
en/volunteer.wml 285) </li>
en/volunteer.wml 286) 

en/volunteer.wml 287) <li>

en/volunteer.wml 288) <b>Tor Controller Status Event Interface</b>

en/volunteer.wml 289) <br />

en/volunteer.wml 290) There are a number of status changes inside Tor of which the user may need

en/volunteer.wml 291) to be informed. For example, if the user is trying to set up his Tor as a
en/volunteer.wml 292) relay and Tor decides that its ports are not reachable from outside

en/volunteer.wml 293) the user's network, we should alert the user. Currently, all the user

en/volunteer.wml 294) gets is a couple log messages in Vidalia's 'message log' window, which they

en/volunteer.wml 295) likely never see since they don't receive a notification that something
en/volunteer.wml 296) has gone wrong. Even if the user does actually look at the message log,
en/volunteer.wml 297) most of the messages make little sense to the novice user.
en/volunteer.wml 298) <br />
en/volunteer.wml 299) Tor has the ability to inform Vidalia of many such status changes, and
en/volunteer.wml 300) we recently implemented support for a couple of these events. Still,
en/volunteer.wml 301) there are many more status events the user should be informed of and we
en/volunteer.wml 302) need a better UI for actually displaying them to the user.
en/volunteer.wml 303) <br />
en/volunteer.wml 304) The goal of this project then is to design and implement a UI for
en/volunteer.wml 305) displaying Tor status events to the user. For example, we might put a
en/volunteer.wml 306) little badge on Vidalia's tray icon that alerts the user to new status
en/volunteer.wml 307) events they should look at. Double-clicking the icon could bring up a
en/volunteer.wml 308) dialog that summarizes recent status events in simple terms and maybe

en/volunteer.wml 309) suggests a remedy for any negative events if they can be corrected by

en/volunteer.wml 310) the user. Of course, this is just an example and one is free to

en/volunteer.wml 311) suggest another approach.
en/volunteer.wml 312) <br />

en/volunteer.wml 313) A person undertaking this project should have good UI design and layout

en/volunteer.wml 314) and some C++ development experience. Previous experience with Qt and

en/volunteer.wml 315) Qt's Designer will be very helpful, but are not required. Some

en/volunteer.wml 316) English writing ability will also be useful, since this project will
en/volunteer.wml 317) likely involve writing small amounts of help documentation that should
en/volunteer.wml 318) be understandable by non-technical users. Bonus points for some graphic
en/volunteer.wml 319) design/Photoshop fu, since we might want/need some shiny new icons too.
en/volunteer.wml 320) </li>
en/volunteer.wml 321) 

en/volunteer.wml 322) <li>

en/volunteer.wml 323) <b>Improvements on our active browser configuration tester</b> -

en/volunteer.wml 324) <a href="https://check.torproject.org/">https://check.torproject.org/</a>

en/volunteer.wml 325) <br />
en/volunteer.wml 326) We currently have a functional web page to detect if Tor is working. It

en/volunteer.wml 327) has a few places where it falls short. It requires improvements with

en/volunteer.wml 328) regard to default languages and functionality. It currently only responds
en/volunteer.wml 329) in English. In addition, it is a hack of a perl script that should have
en/volunteer.wml 330) never seen the light of day. It should probably be rewritten in python

en/volunteer.wml 331) with multi-lingual support in mind. It currently uses the <a
en/volunteer.wml 332) href="http://exitlist.torproject.org/">Tor DNS exit list</a>
en/volunteer.wml 333) and should continue to do so in the future. It currently result in certain

en/volunteer.wml 334) false positives and these should be discovered, documented, and fixed
en/volunteer.wml 335) where possible. Anyone working on this project should be interested in

en/volunteer.wml 336) DNS, basic perl or preferably python programming skills, and will have

en/volunteer.wml 337) to interact minimally with Tor to test their code.

en/volunteer.wml 338) <br />
en/volunteer.wml 339) If you want to make the project more exciting
en/volunteer.wml 340) and involve more design and coding, take a look at <a
en/volunteer.wml 341) href="<svnsandbox>doc/spec/proposals/131-verify-tor-usage.txt">proposal
en/volunteer.wml 342) 131-verify-tor-usage.txt</a>.

en/volunteer.wml 343) </li>
en/volunteer.wml 344) 
en/volunteer.wml 345) <li>

en/volunteer.wml 346) <b>Improvements on our DNS Exit List service</b> -

en/volunteer.wml 347) <a href="http://exitlist.torproject.org/">http://exitlist.torproject.org/</a>

en/volunteer.wml 348) <br />

en/volunteer.wml 349) The <a href="http://p56soo2ibjkx23xo.onion/">exitlist software</a>
en/volunteer.wml 350) is written by our fabulous anonymous

en/volunteer.wml 351) contributer Tup. It's a DNS server written in Haskell that supports part of our <a

en/volunteer.wml 352) href="<svnsandbox>doc/contrib/torel-design.txt">exitlist

en/volunteer.wml 353) design document</a>. Currently, it is functional and it is used by

en/volunteer.wml 354) check.torproject.org and other users. The issues that are outstanding
en/volunteer.wml 355) are mostly aesthetic. This wonderful service could use a much better
en/volunteer.wml 356) website using the common Tor theme. It would be best served with better
en/volunteer.wml 357) documentation for common services that use an RBL. It could use more
en/volunteer.wml 358) publicity. A person working on this project should be interested in DNS,
en/volunteer.wml 359) basic RBL configuration for popular services, and writing documentation.
en/volunteer.wml 360) The person would require minimal Tor interaction — testing their
en/volunteer.wml 361) own documentation at the very least. Furthermore, it would be useful

en/volunteer.wml 362) if they were interested in Haskell and wanted to implement more of the

en/volunteer.wml 363) torel-design.txt suggestions.
en/volunteer.wml 364) </li>
en/volunteer.wml 365) 
en/volunteer.wml 366) <li>

en/volunteer.wml 367) <b>Testing integration of Tor with web browsers for our end users</b>

en/volunteer.wml 368) <br />

en/volunteer.wml 369) The Tor project currently lacks a solid test suite to ensure that a
en/volunteer.wml 370) user has a properly and safely configured web browser. It should test for as

en/volunteer.wml 371) many known issues as possible. It should attempt to decloak the

en/volunteer.wml 372) user in any way possible. Two current webpages that track these

en/volunteer.wml 373) kinds of issues are run by Greg Fleischer and HD Moore. Greg keeps a nice <a

en/volunteer.wml 374) href="http://pseudo-flaw.net/tor/torbutton/">list of issues along
en/volunteer.wml 375) with their proof of concept code, bug issues, etc</a>. HD Moore runs

en/volunteer.wml 376) the <a href="http://metasploit.com/research/projects/decloak/">metasploit

en/volunteer.wml 377) decloak website</a>. A person interested in defending Tor could start

en/volunteer.wml 378) by collecting as many workable and known methods for decloaking a

en/volunteer.wml 379) Tor user. (<a href="https://torcheck.xenobite.eu/">This page</a> may

en/volunteer.wml 380) be helpful as a start.) One should be familiar with the common pitfalls but

en/volunteer.wml 381) possibly have new methods in mind for implementing decloaking issues. The
en/volunteer.wml 382) website should ensure that it tells a user what their problem is. It
en/volunteer.wml 383) should help them to fix the problem or direct them to the proper support

en/volunteer.wml 384) channels. The person should also be closely familiar with using Tor and how

en/volunteer.wml 385) to prevent Tor information leakage.

en/volunteer.wml 386) </li>
en/volunteer.wml 387) 

en/volunteer.wml 388) <li>

en/volunteer.wml 389) <b>Libevent and Tor integration improvements</b>
en/volunteer.wml 390) <br />

en/volunteer.wml 391) Tor should make better use of the more recent features of Niels
en/volunteer.wml 392) Provos's <a href="http://monkey.org/~provos/libevent/">Libevent</a>

en/volunteer.wml 393) library.  Tor already uses Libevent for its low-level asynchronous IO

en/volunteer.wml 394) calls, and could also use Libevent's increasingly good implementations

en/volunteer.wml 395) of network buffers and of HTTP.  This wouldn't be simply a matter of

en/volunteer.wml 396) replacing Tor's internal calls with calls to Libevent: instead, we'll

en/volunteer.wml 397) need to refactor Tor to use Libevent calls that do not follow the

en/volunteer.wml 398) same models as Tor's existing backends. Also, we'll need to add
en/volunteer.wml 399) missing functionality to Libevent as needed — most difficult likely
en/volunteer.wml 400) will be adding OpenSSL support on top of Libevent's buffer abstraction.
en/volunteer.wml 401) Also tricky will be adding rate-limiting to Libevent.

en/volunteer.wml 402) </li>
en/volunteer.wml 403) 
en/volunteer.wml 404) <li>

en/volunteer.wml 405) <b>Tuneup Tor!</b>
en/volunteer.wml 406) <br />

en/volunteer.wml 407) Right now, Tor relays measure and report their own bandwidth, and Tor
en/volunteer.wml 408) clients choose which relays to use in part based on that bandwidth.
en/volunteer.wml 409) This approach is vulnerable to
en/volunteer.wml 410) <a href="http://freehaven.net/anonbib/#bauer:wpes2007">attacks where
en/volunteer.wml 411) relays lie about their bandwidth</a>;
en/volunteer.wml 412) to address this, Tor currently caps the maximum bandwidth
en/volunteer.wml 413) it's willing to believe any relay provides.  This is a limited fix, and
en/volunteer.wml 414) a waste of bandwidth capacity to boot.  Instead,

en/volunteer.wml 415) Tor should possibly measure bandwidth in a more distributed way, perhaps
en/volunteer.wml 416) as described in the

en/volunteer.wml 417) <a href="http://freehaven.net/anonbib/author.html#snader08">"A Tune-up for
en/volunteer.wml 418) Tor"</a> paper

en/volunteer.wml 419) by Snader and Borisov. One could use current testing code to

en/volunteer.wml 420) double-check this paper's findings and verify the extent to which they

en/volunteer.wml 421) dovetail with Tor as deployed in the wild, and determine good ways to
en/volunteer.wml 422) incorporate them into their suggestions Tor network without adding too

en/volunteer.wml 423) much communications overhead between relays and directory

en/volunteer.wml 424) authorities.

en/volunteer.wml 425) </li>
en/volunteer.wml 426) 

en/volunteer.wml 427) <!--

en/volunteer.wml 428) <li>

en/volunteer.wml 429) <b>Improving the Tor QA process: Continuous Integration for Windows builds</b>
en/volunteer.wml 430) <br />

en/volunteer.wml 431) It would be useful to have automated build processes for Windows and
en/volunteer.wml 432) probably other platforms. The purpose of having a continuous integration
en/volunteer.wml 433) build environment is to ensure that Windows isn't left behind for any of
en/volunteer.wml 434) the software projects used in the Tor project or its accompanying.<br />
en/volunteer.wml 435) Buildbot may be a good choice for this as it appears to support all of

en/volunteer.wml 436) the platforms Tor does. See the

en/volunteer.wml 437) <a href="http://en.wikipedia.org/wiki/BuildBot">wikipedia entry for

en/volunteer.wml 438) buildbot</a>.<br />
en/volunteer.wml 439) There may be better options and the person undertaking this task should
en/volunteer.wml 440) evaluate other options. Any person working on this automatic build
en/volunteer.wml 441) process should have experience or be willing to learn how to build all
en/volunteer.wml 442) of the respective Tor related code bases from scratch. Furthermore, the
en/volunteer.wml 443) person should have some experience building software in Windows
en/volunteer.wml 444) environments as this is the target audience we want to ensure we do not
en/volunteer.wml 445) leave behind. It would require close work with the Tor source code but

en/volunteer.wml 446) probably only in the form of building, not authoring.<br />
en/volunteer.wml 447) Additionally, we need to automate our performance testing for all platforms.

en/volunteer.wml 448) We've got buildbot (except on Windows — as noted above) to automate

en/volunteer.wml 449) our regular integration and compile testing already,
en/volunteer.wml 450) but we need to get our network simulation tests (as built in torflow)
en/volunteer.wml 451) updated for more recent versions of Tor, and designed to launch a test
en/volunteer.wml 452) network either on a single machine, or across several, so we can test

en/volunteer.wml 453) changes in performance on machines in different roles automatically.

en/volunteer.wml 454) </li>

en/volunteer.wml 455) -->

en/volunteer.wml 456) 

en/volunteer.wml 457) <li>

en/volunteer.wml 458) <b>Improve our unit testing process</b>
en/volunteer.wml 459) <br />

en/volunteer.wml 460) Tor needs to be far more tested. This is a multi-part effort. To start

en/volunteer.wml 461) with, our unit test coverage should rise substantially, especially in

en/volunteer.wml 462) the areas outside the utility functions. This will require significant

en/volunteer.wml 463) refactoring of some parts of Tor, in order to dissociate as much logic

en/volunteer.wml 464) as possible from globals.
en/volunteer.wml 465) <br />

en/volunteer.wml 466) Additionally, we need to automate our performance testing. We've got

en/volunteer.wml 467) buildbot to automate our regular integration and compile testing already
en/volunteer.wml 468) (though we need somebody to set it up on Windows),
en/volunteer.wml 469) but we need to get our network simulation tests (as built in TorFlow: see
en/volunteer.wml 470) the "Tor Node Scanner improvements" item)

en/volunteer.wml 471) updated for more recent versions of Tor, and designed to launch a test
en/volunteer.wml 472) network either on a single machine, or across several, so we can test

en/volunteer.wml 473) changes in performance on machines in different roles automatically.

en/volunteer.wml 474) </li>
en/volunteer.wml 475) 

en/volunteer.wml 476) <li>

en/volunteer.wml 477) <b>Help revive an independent Tor client implementation</b>

en/volunteer.wml 478) <br />

en/volunteer.wml 479) Reanimate one of the approaches to implement a Tor client in Java,
en/volunteer.wml 480) e.g. the <a href="http://onioncoffee.sourceforge.net/">OnionCoffee
en/volunteer.wml 481) project</a>, and make it run on <a
en/volunteer.wml 482) href="http://code.google.com/android/">Android</a>. The first step
en/volunteer.wml 483) would be to port the existing code and execute it in an Android
en/volunteer.wml 484) environment. Next, the code should be updated to support the newer Tor
en/volunteer.wml 485) protocol versions like the <a href="<svnsandbox>doc/spec/dir-spec.txt">v3
en/volunteer.wml 486) directory protocol</a>. Further, support for requesting or even

en/volunteer.wml 487) providing Tor hidden services would be neat, but not required.
en/volunteer.wml 488) <br />

en/volunteer.wml 489) A prospective developer should be able to understand and write new Java
en/volunteer.wml 490) code, including

en/volunteer.wml 491) a Java cryptography API. Being able to read C code would be helpful,

en/volunteer.wml 492) too. One should be willing to read the existing documentation,

en/volunteer.wml 493) implement code based on it, and refine the documentation
en/volunteer.wml 494) when things are underdocumented. This project is mostly about coding and

en/volunteer.wml 495) to a small degree about design.
en/volunteer.wml 496) </li>
en/volunteer.wml 497) 
en/volunteer.wml 498) <li>

en/volunteer.wml 499) <b>Bring moniTor to life</b>
en/volunteer.wml 500) <br />

en/volunteer.wml 501) Implement a <a href="http://www.ss64.com/bash/top.html">top-like</a>
en/volunteer.wml 502) management tool for Tor relays. The purpose of such a tool would be
en/volunteer.wml 503) to monitor a local Tor relay via its control port and include useful
en/volunteer.wml 504) system information of the underlying machine. When running this tool, it
en/volunteer.wml 505) would dynamically update its content like top does for Linux processes.
en/volunteer.wml 506) <a href="http://archives.seul.org/or/dev/Jan-2008/msg00005.html">This

en/volunteer.wml 507) or-dev post</a> might be a good first read.
en/volunteer.wml 508) <br />

en/volunteer.wml 509) A person interested in this should be familiar

en/volunteer.wml 510) with or willing to learn about administering a Tor relay and configuring
en/volunteer.wml 511) it via its control port. As an initial prototype is written in Python,
en/volunteer.wml 512) some knowledge about writing Python code would be helpful, too. This

en/volunteer.wml 513) project is one part about identifying requirements to such a
en/volunteer.wml 514) tool and designing its interface, and one part lots of coding.

en/volunteer.wml 515) </li>
en/volunteer.wml 516) 

en/volunteer.wml 517) <li>
en/volunteer.wml 518) <b>Torbutton improvements</b>
en/volunteer.wml 519) <br />
en/volunteer.wml 520) Torbutton has a number of improvements that can be made in the post-1.2
en/volunteer.wml 521) timeframe. Most of these are documented as feature requests in the <a

en/volunteer.wml 522) href="https://bugs.torproject.org/flyspray/index.php?tasks=all&project=5">Torbutton

en/volunteer.wml 523) flyspray section</a>. Good examples include: stripping off node.exit on http
en/volunteer.wml 524) headers, more fine-grained control over formfill blocking, improved referrer

en/volunteer.wml 525) spoofing based on the domain of the site (a-la <a

en/volunteer.wml 526) href="https://addons.mozilla.org/en-US/firefox/addon/953">refcontrol extension</a>),

en/volunteer.wml 527) tighter integration with Vidalia for reporting Tor status, a New Identity
en/volunteer.wml 528) button with Tor integration and multiple identity management, and anything

en/volunteer.wml 529) else you might think of.

en/volunteer.wml 530) <br />
en/volunteer.wml 531) This work would be independent coding in Javascript and the fun world of <a
en/volunteer.wml 532) href="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">XUL</a>,
en/volunteer.wml 533) with not too much involvement in the Tor internals.

en/volunteer.wml 534) </li>
en/volunteer.wml 535) 

en/volunteer.wml 536) <li>

en/volunteer.wml 537) <b>Porting Polipo to Windows</b>
en/volunteer.wml 538) <br />

en/volunteer.wml 539) Help port <a
en/volunteer.wml 540) href="http://www.pps.jussieu.fr/~jch/software/polipo/">Polipo</a> to

en/volunteer.wml 541) Windows. Example topics to tackle include:
en/volunteer.wml 542) 1) handle spaces in path names and understand the filesystem
en/volunteer.wml 543) namespace — that is, where application data, personal data,

en/volunteer.wml 544) and program data typically reside in various versions of Windows. 2) the
en/volunteer.wml 545) ability to handle ipv6 communications. 3) the ability to asynchronously
en/volunteer.wml 546) query name servers, find the system nameservers, and manage netbios
en/volunteer.wml 547) and dns queries. 4) use native regex capabilities of Windows, rather
en/volunteer.wml 548) than using 3rd party GNU regex libraries. 5) manage events and buffers
en/volunteer.wml 549) natively (i.e. in Unix-like OSes, Polipo defaults to 25% of ram, in
en/volunteer.wml 550) Windows it's whatever the config specifies). 6) some sort of GUI config
en/volunteer.wml 551) and reporting tool, bonus if it has a systray icon with right clickable
en/volunteer.wml 552) menu options. Double bonus if it's cross-platform compatible.
en/volunteer.wml 553) </li>
en/volunteer.wml 554) 
en/volunteer.wml 555) <li>

en/volunteer.wml 556) <b>Make our diagrams beautiful and automated</b>

en/volunteer.wml 557) <br />

en/volunteer.wml 558) We need a way to generate the website diagrams (for example, the "How
en/volunteer.wml 559) Tor Works" pictures on the <a href="<page overview>">overview page</a>
en/volunteer.wml 560) from source, so we can translate them as UTF-8 text rather than edit
en/volunteer.wml 561) them by hand with Gimp. We might want to
en/volunteer.wml 562) integrate this as an wml file so translations are easy and images are

en/volunteer.wml 563) generated in multiple languages whenever we build the website. 

en/volunteer.wml 564) </li>
en/volunteer.wml 565) 

en/volunteer.wml 566) <li>
en/volunteer.wml 567) <b>Improve the LiveCD offerings for the Tor community</b>
en/volunteer.wml 568) <br />
en/volunteer.wml 569) How can we make the <a

en/volunteer.wml 570) href="http://anonymityanywhere.com/incognito/">Incognito LiveCD</a>

en/volunteer.wml 571) easier to maintain, improve, and document?
en/volunteer.wml 572) </li>

en/volunteer.wml 573) 

en/volunteer.wml 574) <li>
en/volunteer.wml 575) <b>Rework and extend Blossom</b>
en/volunteer.wml 576) <br />
en/volunteer.wml 577) Rework and extend Blossom (a tool for monitoring and
en/volunteer.wml 578) selecting appropriate Tor circuits based upon exit node requirements
en/volunteer.wml 579) specified by the user) to gather data in a self-contained way, with
en/volunteer.wml 580) parameters easily configurable by the user.  Blossom is presently
en/volunteer.wml 581) implemented as a single Python script that interfaces with Tor using the
en/volunteer.wml 582) Controller interface and depends upon metadata about Tor nodes obtained
en/volunteer.wml 583) via external processes, such as a webpage indicating status of the nodes
en/volunteer.wml 584) plus publically available data from DNS, whois, etc.  This project has
en/volunteer.wml 585) two parts: (1) Determine which additional metadata may be useful and
en/volunteer.wml 586) rework Blossom so that it cleanly obtains the metadata on its own rather
en/volunteer.wml 587) than depend upon external scripts (this may, for example, involve
en/volunteer.wml 588) additional threads or inter-process communication), and (2) develop a
en/volunteer.wml 589) means by which the user can easily configure Blossom, starting with a
en/volunteer.wml 590) configuration file and possibly working up to a web configuration engine.

en/volunteer.wml 591) Knowledge of Tor and Python are important; knowledge of
en/volunteer.wml 592) TCP, interprocess communication, and Perl will also be helpful.  An
en/volunteer.wml 593) interest in network neutrality is important as well, since the
en/volunteer.wml 594) principles of evaluating and understanding internet inconsistency are at
en/volunteer.wml 595) the core of the Blossom effort.

en/volunteer.wml 596) </li>
en/volunteer.wml 597) 
en/volunteer.wml 598) <li>
en/volunteer.wml 599) <b>Improve Blossom: Allow users to qualitatively describe exit nodes they desire</b>
en/volunteer.wml 600) <br />
en/volunteer.wml 601) Develop and implement a means of affording Blossom
en/volunteer.wml 602) users the ability to qualitatively describe the exit node that they
en/volunteer.wml 603) want.  The Internet is an inconsistent place: some Tor exit nodes see
en/volunteer.wml 604) the world differently than others.  As presently implemented, Blossom (a
en/volunteer.wml 605) tool for monitoring and selecting appropriate Tor circuits based upon
en/volunteer.wml 606) exit node requirements specified by the user) lacks a sufficiently rich
en/volunteer.wml 607) language to describe how the different vantage points are different.
en/volunteer.wml 608) For example, some exit nodes may have an upstream network that filters
en/volunteer.wml 609) certain kinds of traffic or certain websites.  Other exit nodes may
en/volunteer.wml 610) provide access to special content as a result of their location, perhaps
en/volunteer.wml 611) as a result of discrimination on the part of the content providers
en/volunteer.wml 612) themselves.  This project has two parts: (1) develop a language for
en/volunteer.wml 613) describing characteristics of networks in which exit nodes reside, and
en/volunteer.wml 614) (2) incorporate this language into Blossom so that users can select Tor
en/volunteer.wml 615) paths based upon the description.

en/volunteer.wml 616) Knowledge of Tor and Python are important; knowledge of
en/volunteer.wml 617) TCP, interprocess communication, and Perl will also be helpful.  An
en/volunteer.wml 618) interest in network neutrality is important as well, since the
en/volunteer.wml 619) principles of evaluating and understanding internet inconsistency are at
en/volunteer.wml 620) the core of the Blossom effort.

en/volunteer.wml 621) </li>
en/volunteer.wml 622) 

en/volunteer.wml 623) <li>
en/volunteer.wml 624) <b>Bring up new ideas!</b>
en/volunteer.wml 625) <br />
en/volunteer.wml 626) Don't like any of these? Look at the <a

en/volunteer.wml 627) href="<svnsandbox>doc/roadmaps/2008-12-19-roadmap-full.pdf">Tor development

en/volunteer.wml 628) roadmap</a> for more ideas.
en/volunteer.wml 629) </li>
en/volunteer.wml 630) 

en/volunteer.wml 631) </ol>
en/volunteer.wml 632) 

en/volunteer.wml 633) <a id="OtherCoding"></a>
en/volunteer.wml 634) <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>

volunteer.html   635) <ol>

en/volunteer.wml 636) <li>Tor relays don't work well on Windows XP. On

en/volunteer.wml 637) Windows, Tor uses the standard <tt>select()</tt> system

en/volunteer.wml 638) call, which uses space in the non-page pool. This means

en/volunteer.wml 639) that a medium sized Tor relay will empty the non-page pool, <a

en/volunteer.wml 640) href="https://wiki.torproject.org/noreply/TheOnionRouter/WindowsBufferProblems">causing

en/volunteer.wml 641) havoc and system crashes</a>. We should probably be using overlapped IO

en/volunteer.wml 642) instead. One solution would be to teach <a
en/volunteer.wml 643) href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
en/volunteer.wml 644) overlapped IO rather than select() on Windows, and then adapt Tor to

en/volunteer.wml 645) the new libevent interface. Christian King made a

en/volunteer.wml 646) <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good

en/volunteer.wml 647) start</a> on this in the summer of 2007.</li>

en/volunteer.wml 648) 

en/volunteer.wml 649) <li>We need to actually start building our <a href="<page
en/volunteer.wml 650) documentation>#DesignDoc">blocking-resistance design</a>. This involves

en/volunteer.wml 651) fleshing out the design, modifying many different pieces of Tor, adapting
en/volunteer.wml 652) <a href="http://vidalia-project.net/">Vidalia</a> so it supports the
en/volunteer.wml 653) new features, and planning for deployment.</li>

en/volunteer.wml 654) 

en/volunteer.wml 655) <li>We need a flexible simulator framework for studying end-to-end
en/volunteer.wml 656) traffic confirmation attacks. Many researchers have whipped up ad hoc
en/volunteer.wml 657) simulators to support their intuition either that the attacks work
en/volunteer.wml 658) really well or that some defense works great. Can we build a simulator
en/volunteer.wml 659) that's clearly documented and open enough that everybody knows it's
en/volunteer.wml 660) giving a reasonable answer? This will spur a lot of new research.
en/volunteer.wml 661) See the entry <a href="#Research">below</a> on confirmation attacks for
en/volunteer.wml 662) details on the research side of this task &mdash; who knows, when it's
en/volunteer.wml 663) done maybe you can help write a paper or three also.</li>

en/volunteer.wml 664) 

en/volunteer.wml 665) <li>Tor 0.1.1.x and later include support for hardware crypto accelerators

en/volunteer.wml 666) via OpenSSL. Nobody has ever tested it, though. Does somebody want to get

volunteer.html   667) a card and let us know how it goes?</li>

en/volunteer.wml 668) 

volunteer.html   669) <li>Perform a security analysis of Tor with <a
volunteer.html   670) href="http://en.wikipedia.org/wiki/Fuzz_testing">"fuzz"</a>. Determine

en/volunteer.wml 671) if there are good fuzzing libraries out there for what we want. Win fame by

volunteer.html   672) getting credit when we put out a new release because of you!</li>

en/volunteer.wml 673) 

volunteer.html   674) <li>Tor uses TCP for transport and TLS for link
volunteer.html   675) encryption. This is nice and simple, but it means all cells
volunteer.html   676) on a link are delayed when a single packet gets dropped, and
volunteer.html   677) it means we can only reasonably support TCP streams. We have a <a

en/volunteer.wml 678) href="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#TransportIPnotTCP">list

en/volunteer.wml 679) of reasons why we haven't shifted to UDP transport</a>, but it would
en/volunteer.wml 680) be great to see that list get shorter. We also have a proposed <a

en/volunteer.wml 681) href="<svnsandbox>doc/spec/proposals/100-tor-spec-udp.txt">specification
en/volunteer.wml 682) for Tor and

en/volunteer.wml 683) UDP</a> &mdash; please let us know what's wrong with it.</li>

en/volunteer.wml 684) 

volunteer.html   685) <li>We're not that far from having IPv6 support for destination addresses
volunteer.html   686) (at exit nodes). If you care strongly about IPv6, that's probably the
volunteer.html   687) first place to start.</li>

volunteer.html   688) </ol>
volunteer.html   689) 

en/volunteer.wml 690) <a id="Research"></a>
en/volunteer.wml 691) <h2><a class="anchor" href="#Research">Research</a></h2>

volunteer.html   692) <ol>

volunteer.html   693) <li>The "website fingerprinting attack": make a list of a few
volunteer.html   694) hundred popular websites, download their pages, and make a set of
volunteer.html   695) "signatures" for each site. Then observe a Tor client's traffic. As
volunteer.html   696) you watch him receive data, you quickly approach a guess about which
volunteer.html   697) (if any) of those sites he is visiting. First, how effective is
volunteer.html   698) this attack on the deployed Tor codebase? Then start exploring
volunteer.html   699) defenses: for example, we could change Tor's cell size from 512
volunteer.html   700) bytes to 1024 bytes, we could employ padding techniques like <a
volunteer.html   701) href="http://freehaven.net/anonbib/#timing-fc2004">defensive dropping</a>,
volunteer.html   702) or we could add traffic delays. How much of an impact do these have,
volunteer.html   703) and how much usability impact (using some suitable metric) is there from
volunteer.html   704) a successful defense in each case?</li>

volunteer.html   705) <li>The "end-to-end traffic confirmation attack":
volunteer.html   706) by watching traffic at Alice and at Bob, we can <a
volunteer.html   707) href="http://freehaven.net/anonbib/#danezis:pet2004">compare
volunteer.html   708) traffic signatures and become convinced that we're watching the same
volunteer.html   709) stream</a>. So far Tor accepts this as a fact of life and assumes this
volunteer.html   710) attack is trivial in all cases. First of all, is that actually true? How
volunteer.html   711) much traffic of what sort of distribution is needed before the adversary
volunteer.html   712) is confident he has won? Are there scenarios (e.g. not transmitting much)
volunteer.html   713) that slow down the attack? Do some traffic padding or traffic shaping
volunteer.html   714) schemes work better than others?</li>

en/volunteer.wml 715) <li>A related question is: Does running a relay/bridge provide additional
en/volunteer.wml 716) protection against these timing attacks? Can an external adversary that can't

en/volunteer.wml 717) see inside TLS links still recognize individual streams reliably?

en/volunteer.wml 718) Does the amount of traffic carried degrade this ability any? What if the
en/volunteer.wml 719) client-relay deliberately delayed upstream relayed traffic to create a queue
en/volunteer.wml 720) that could be used to mimic timings of client downstream traffic to make it
en/volunteer.wml 721) look like it was also relayed? This same queue could also be used for masking
en/volunteer.wml 722) timings in client upstream traffic with the techniques from <a
en/volunteer.wml 723) href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
en/volunteer.wml 724) but without the need for additional traffic. Would such an interleaving of
en/volunteer.wml 725) client upstream traffic obscure timings for external adversaries? Would the
en/volunteer.wml 726) strategies need to be adjusted for asymmetric links? For example, on
en/volunteer.wml 727) asymmetric links, is it actually possible to differentiate client traffic from
en/volunteer.wml 728) natural bursts due to their asymmetric capacity? Or is it easier than
en/volunteer.wml 729) symmetric links for some other reason?</li>

en/volunteer.wml 730) <li>Repeat Murdoch and Danezis's <a
en/volunteer.wml 731) href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
en/volunteer.wml 732) Oakland 05</a> on the current Tor network. See if you can learn why it
en/volunteer.wml 733) works well on some nodes and not well on others. (My theory is that the
en/volunteer.wml 734) fast nodes with spare capacity resist the attack better.) If that's true,
en/volunteer.wml 735) then experiment with the RelayBandwidthRate and RelayBandwidthBurst
en/volunteer.wml 736) options to run a relay that is used as a client while relaying the
en/volunteer.wml 737) attacker's traffic: as we crank down the RelayBandwidthRate, does the
en/volunteer.wml 738) attack get harder? What's the right ratio of RelayBandwidthRate to
en/volunteer.wml 739) actually capacity? Or is it a ratio at all? While we're at it, does a
en/volunteer.wml 740) much larger set of candidate relays increase the false positive rate
en/volunteer.wml 741) or other complexity for the attack? (The Tor network is now almost two
en/volunteer.wml 742) orders of magnitude larger than it was when they wrote their paper.) Be
en/volunteer.wml 743) sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
en/volunteer.wml 744) Clog the Queue</a> too.</li>

volunteer.html   745) <li>The "routing zones attack": most of the literature thinks of
volunteer.html   746) the network path between Alice and her entry node (and between the
volunteer.html   747) exit node and Bob) as a single link on some graph. In practice,
volunteer.html   748) though, the path traverses many autonomous systems (ASes), and <a
volunteer.html   749) href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
volunteer.html   750) that the same AS appears on both the entry path and the exit path</a>.
volunteer.html   751) Unfortunately, to accurately predict whether a given Alice, entry,
volunteer.html   752) exit, Bob quad will be dangerous, we need to download an entire Internet
volunteer.html   753) routing zone and perform expensive operations on it. Are there practical
volunteer.html   754) approximations, such as avoiding IP addresses in the same /8 network?</li>

en/volunteer.wml 755) <li>Other research questions regarding geographic diversity consider
en/volunteer.wml 756) the tradeoff between choosing an efficient circuit and choosing a random

en/volunteer.wml 757) circuit. Look at Stephen Rollyson's <a

en/volunteer.wml 758) href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
en/volunteer.wml 759) paper</a> on how to discard particularly slow choices without hurting

en/volunteer.wml 760) anonymity "too much". This line of reasoning needs more work and more
en/volunteer.wml 761) thinking, but it looks very promising.</li>

en/volunteer.wml 762) <li>Tor doesn't work very well when relays have asymmetric bandwidth

volunteer.html   763) (e.g. cable or DSL). Because Tor has separate TCP connections between
volunteer.html   764) each hop, if the incoming bytes are arriving just fine and the outgoing
volunteer.html   765) bytes are all getting dropped on the floor, the TCP push-back mechanisms
volunteer.html   766) don't really transmit this information back to the incoming streams.
volunteer.html   767) Perhaps Tor should detect when it's dropping a lot of outgoing packets,
volunteer.html   768) and rate-limit incoming streams to regulate this itself? I can imagine
volunteer.html   769) a build-up and drop-off scheme where we pick a conservative rate-limit,
volunteer.html   770) slowly increase it until we get lost packets, back off, repeat. We
volunteer.html   771) need somebody who's good with networks to simulate this and help design
volunteer.html   772) solutions; and/or we need to understand the extent of the performance
volunteer.html   773) degradation, and use this as motivation to reconsider UDP transport.</li>
volunteer.html   774) <li>A related topic is congestion control. Is our
volunteer.html   775) current design sufficient once we have heavy use? Maybe
volunteer.html   776) we should experiment with variable-sized windows rather
volunteer.html   777) than fixed-size windows? That seemed to go well in an <a
volunteer.html   778) href="http://www.psc.edu/networking/projects/hpn-ssh/theory.php">ssh
volunteer.html   779) throughput experiment</a>. We'll need to measure and tweak, and maybe
volunteer.html   780) overhaul if the results are good.</li>

en/volunteer.wml 781) <li>Our censorship-resistance goals include preventing
en/volunteer.wml 782) an attacker who's looking at Tor traffic on the wire from <a

en/volunteer.wml 783) href="<svnsandbox>doc/design-paper/blocking.html#sec:network-fingerprint">distinguishing

en/volunteer.wml 784) it from normal SSL traffic</a>. Obviously we can't achieve perfect
en/volunteer.wml 785) steganography and still remain usable, but for a first step we'd like to
en/volunteer.wml 786) block any attacks that can win by observing only a few packets. One of
en/volunteer.wml 787) the remaining attacks we haven't examined much is that Tor cells are 512
en/volunteer.wml 788) bytes, so the traffic on the wire may well be a multiple of 512 bytes.
en/volunteer.wml 789) How much does the batching and overhead in TLS records blur this on the
en/volunteer.wml 790) wire? Do different buffer flushing strategies in Tor affect this? Could
en/volunteer.wml 791) a bit of padding help a lot, or is this an attack we must accept?</li>

volunteer.html   792) <li>Tor circuits are built one hop at a time, so in theory we have the
volunteer.html   793) ability to make some streams exit from the second hop, some from the
volunteer.html   794) third, and so on. This seems nice because it breaks up the set of exiting

en/volunteer.wml 795) streams that a given relay can see. But if we want each stream to be safe,

volunteer.html   796) the "shortest" path should be at least 3 hops long by our current logic, so
volunteer.html   797) the rest will be even longer. We need to examine this performance / security
volunteer.html   798) tradeoff.</li>

en/volunteer.wml 799) <li>It's not that hard to DoS Tor relays or directory authorities. Are client

volunteer.html   800) puzzles the right answer? What other practical approaches are there? Bonus
volunteer.html   801) if they're backward-compatible with the current Tor protocol.</li>

en/volunteer.wml 802) <li>Programs like <a

en/volunteer.wml 803) href="<page torbutton/index>">Torbutton</a> aim to hide

en/volunteer.wml 804) your browser's UserAgent string by replacing it with a uniform answer for
en/volunteer.wml 805) every Tor user. That way the attacker can't splinter Tor's anonymity set
en/volunteer.wml 806) by looking at that header. It tries to pick a string that is commonly used
en/volunteer.wml 807) by non-Tor users too, so it doesn't stand out. Question one: how badly
en/volunteer.wml 808) do we hurt ourselves by periodically updating the version of Firefox
en/volunteer.wml 809) that Torbutton claims to be? If we update it too often, we splinter the
en/volunteer.wml 810) anonymity sets ourselves. If we don't update it often enough, then all the
en/volunteer.wml 811) Tor users stand out because they claim to be running a quite old version
en/volunteer.wml 812) of Firefox. The answer here probably depends on the Firefox versions seen
en/volunteer.wml 813) in the wild. Question two: periodically people ask us to cycle through N
en/volunteer.wml 814) UserAgent strings rather than stick with one. Does this approach help,
en/volunteer.wml 815) hurt, or not matter? Consider: cookies and recognizing Torbutton users
en/volunteer.wml 816) by their rotating UserAgents; malicious websites who only attack certain
en/volunteer.wml 817) browsers; and whether the answers to question one impact this answer.
en/volunteer.wml 818) </li>

en/volunteer.wml 819) <li>Right now Tor clients are willing to reuse a given circuit for ten
en/volunteer.wml 820) minutes after it's first used. The goal is to avoid loading down the
en/volunteer.wml 821) network with too many circuit extend operations, yet to also avoid having
en/volunteer.wml 822) clients use the same circuit for so long that the exit node can build a
en/volunteer.wml 823) useful pseudonymous profile of them. Alas, ten minutes is probably way
en/volunteer.wml 824) too long, especially if connections from multiple protocols (e.g. IM and
en/volunteer.wml 825) web browsing) are put on the same circuit. If we keep fixed the overall
en/volunteer.wml 826) number of circuit extends that the network needs to do, are there more
en/volunteer.wml 827) efficient and/or safer ways for clients to allocate streams to circuits,
en/volunteer.wml 828) or for clients to build preemptive circuits? Perhaps this research item
en/volunteer.wml 829) needs to start with gathering some traces of what connections typical
en/volunteer.wml 830) clients try to launch, so you have something realistic to try to optimize.
en/volunteer.wml 831) </li>
en/volunteer.wml 832) <li>How many bridge relays do you need to know to maintain
en/volunteer.wml 833) reachability? We should measure the churn in our bridges. If there is
en/volunteer.wml 834) lots of churn, are there ways to keep bridge users more likely to stay
en/volunteer.wml 835) connected?
en/volunteer.wml 836) </li>

volunteer.html   837) </ol>
volunteer.html   838) 

en/volunteer.wml 839) <p>

en/volunteer.wml 840) <a href="<page contact>">Let us know</a> if you've made progress on any
en/volunteer.wml 841) of these!

en/volunteer.wml 842) </p>

volunteer.html   843) 

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