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en/volunteer.wml   4) #include "head.wmi" TITLE="Tor: Volunteer"

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en/volunteer.wml   9) <h2>Three things everyone can do now:</h2>

volunteer.html    10) <ol>

en/volunteer.wml  11) <li>Please consider <a href="<page docs/tor-doc-relay>">running
en/volunteer.wml  12) a relay</a> to help the Tor network grow.</li>
en/volunteer.wml  13) <li>Tell your friends! Get them to run relays. Get them to run hidden

volunteer.html    14) services. Get them to tell their friends.</li>

en/volunteer.wml  15) <li>We are looking for funding and sponsors. If you like Tor's goals, please

en/volunteer.wml  16)   <a href="<page donate>">take a moment to donate to support further
en/volunteer.wml  17)   Tor development</a>. Also, if you know any

en/volunteer.wml  18)   companies, NGOs, agencies, or other organizations that want communications

en/volunteer.wml  19)   security, let them know about us.</li>

volunteer.html    20) </ol>
volunteer.html    21) 

en/volunteer.wml  22) <a id="Usability"></a>

en/volunteer.wml  23) <h2><a class="anchor" href="#Usability">Supporting Applications</a></h2>

volunteer.html    24) <ol>

en/volunteer.wml  25) <li>We need good ways to intercept DNS requests so they don't "leak" their
en/volunteer.wml  26) request to a local observer while we're trying to be anonymous. (This
en/volunteer.wml  27) happens because the application does the DNS resolve before going to
en/volunteer.wml  28) the SOCKS proxy.)</li>

en/volunteer.wml  29) <li>Tsocks/dsocks items:

en/volunteer.wml  30) <ul>
en/volunteer.wml  31) <li>We need to <a

en/volunteer.wml  32) href="https://wiki.torproject.org/noreply/TheOnionRouter/TSocksPatches">apply

en/volunteer.wml  33) all our tsocks patches</a> and maintain a new fork. We'll host it if
en/volunteer.wml  34) you want.</li>
en/volunteer.wml  35) <li>We should patch Dug Song's "dsocks" program to use Tor's
en/volunteer.wml  36) <i>mapaddress</i> commands from the controller interface, so we
en/volunteer.wml  37) don't waste a whole round-trip inside Tor doing the resolve before
en/volunteer.wml  38) connecting.</li>
en/volunteer.wml  39) <li>We need to make our <i>torify</i> script detect which of tsocks or
en/volunteer.wml  40) dsocks is installed, and call them appropriately. This probably means
en/volunteer.wml  41) unifying their interfaces, and might involve sharing code between them
en/volunteer.wml  42) or discarding one entirely.</li>
en/volunteer.wml  43) </ul>

en/volunteer.wml  44) </li>

en/volunteer.wml  45) <li>People running relays tell us they want to have one BandwidthRate

en/volunteer.wml  46) during some part of the day, and a different BandwidthRate at other
en/volunteer.wml  47) parts of the day. Rather than coding this inside Tor, we should have a
en/volunteer.wml  48) little script that speaks via the <a href="<page gui/index>">Tor
en/volunteer.wml  49) Controller Interface</a>, and does a setconf to change the bandwidth
en/volunteer.wml  50) rate.  There is one for Unix and Mac already (it uses bash and cron),
en/volunteer.wml  51) but Windows users still need a solution.

en/volunteer.wml  52) </li>

en/volunteer.wml  53) <li>Tor can <a

en/volunteer.wml  54) href="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#ChooseEntryExit">exit

en/volunteer.wml  55) the Tor network from a particular exit node</a>, but we should be able
en/volunteer.wml  56) to specify just a country and have something automatically pick. The
en/volunteer.wml  57) best bet is to fetch Blossom's directory also, and run a local Blossom
en/volunteer.wml  58) client that fetches this directory securely (via Tor and checking its
en/volunteer.wml  59) signature), intercepts <tt>.country.blossom</tt> hostnames, and does
en/volunteer.wml  60) the right thing.</li>

volunteer.html    61) <li>Speaking of geolocation data, somebody should draw a map of the Earth

en/volunteer.wml  62) with a pin-point for each Tor relay. Bonus points if it updates as the

en/volunteer.wml  63) network grows and changes. Unfortunately, the easy ways to do this involve
en/volunteer.wml  64) sending all the data to Google and having them draw the map for you. How
en/volunteer.wml  65) much does this impact privacy, and do we have any other good options?</li>

volunteer.html    66) </ol>
volunteer.html    67) 

en/volunteer.wml  68) <a id="Documentation"></a>
en/volunteer.wml  69) <h2><a class="anchor" href="#Documentation">Documentation</a></h2>

volunteer.html    70) <ol>

en/volunteer.wml  71) <li>Please help Matt Edman with the documentation and how-tos for his

en/volunteer.wml  72) Tor controller,
en/volunteer.wml  73) <a href="http://vidalia-project.net/">Vidalia</a>.</li>

en/volunteer.wml  74) <li>Evaluate and document

en/volunteer.wml  75) <a href="https://wiki.torproject.org/wiki/TheOnionRouter/TorifyHOWTO">our

en/volunteer.wml  76) list of programs</a> that can be configured to use Tor.</li>

volunteer.html    77) <li>We need better documentation for dynamically intercepting

en/volunteer.wml  78) connections and sending them through Tor. tsocks (Linux), dsocks (BSD),

en/volunteer.wml  79) and freecap (Windows) seem to be good candidates, as would better
en/volunteer.wml  80) use of our new TransPort feature.</li>

en/volunteer.wml  81) <li>We have a huge list of <a href="https://wiki.torproject.org/noreply/TheOnionRouter/SupportPrograms">potentially useful

volunteer.html    82) programs that interface to Tor</a>. Which ones are useful in which
volunteer.html    83) situations? Please help us test them out and document your results.</li>

en/volunteer.wml  84) <li>Help translate the web page and documentation into other
en/volunteer.wml  85) languages. See the <a href="<page translation>">translation

en/volunteer.wml  86) guidelines</a> if you want to help out. We especially need Arabic or
en/volunteer.wml  87) Farsi translations, for the many Tor users in censored areas.</li>

volunteer.html    88) </ol>
volunteer.html    89) 

en/volunteer.wml  90) <a id="Coding"></a>

en/volunteer.wml  91) <a id="Summer"></a>
en/volunteer.wml  92) <a id="Projects"></a>

en/volunteer.wml  93) <h2><a class="anchor" href="#Projects">Good Coding Projects</a></h2>

en/volunteer.wml  94) <ol>
en/volunteer.wml  95) 

en/volunteer.wml  96) <li>
en/volunteer.wml  97) Reanimate one of the approaches to implement a Tor client in Java,
en/volunteer.wml  98) e.g. the <a href="http://onioncoffee.sourceforge.net/">OnionCoffee
en/volunteer.wml  99) project</a>, and make it run on <a
en/volunteer.wml 100) href="http://code.google.com/android/">Android</a>. The first step
en/volunteer.wml 101) would be to port the existing code and execute it in an Android
en/volunteer.wml 102) environment. Next, the code should be updated to support the newer Tor
en/volunteer.wml 103) protocol versions like the <a href="<svnsandbox>doc/spec/dir-spec.txt">v3
en/volunteer.wml 104) directory protocol</a>. Further, support for requesting or even
en/volunteer.wml 105) providing Tor hidden services would be neat, but not required. The
en/volunteer.wml 106) student should be able to understand and write new Java code, including
en/volunteer.wml 107) a Java cryptography API. Being able to read C code would be helping,
en/volunteer.wml 108) too. The student should be willing to read the existing documentation,
en/volunteer.wml 109) implement code based on it, and, if required, refine the documentation
en/volunteer.wml 110) if things are underdocumented. This project is mostly about coding and
en/volunteer.wml 111) to a small degree about design.
en/volunteer.wml 112) </li>
en/volunteer.wml 113) 
en/volunteer.wml 114) <li>
en/volunteer.wml 115) Write a tool that runs automatic system tests in addition
en/volunteer.wml 116) to the existing unit tests. The Java-based Tor simulator <a
en/volunteer.wml 117) href="https://tor-svn.freehaven.net/svn/puppetor/trunk/">PuppeTor</a>
en/volunteer.wml 118) might be a good start for starting up a private Tor network, using it
en/volunteer.wml 119) for a while, and verifying that at least parts of it are working. This
en/volunteer.wml 120) project requires to conceive a blueprint for performing system tests
en/volunteer.wml 121) of private Tor networks, before starting to code. Typical types of
en/volunteer.wml 122) tests range from performing single requests over the private network to
en/volunteer.wml 123) manipulating exchanged messages and see if nodes handle corrupt messages
en/volunteer.wml 124) appropriately. The student should be able to obtain a good understanding
en/volunteer.wml 125) of how Tor works and what problems and bugs could arise to design good
en/volunteer.wml 126) test cases. Understanding the existing Tor code and documentation is
en/volunteer.wml 127) vital. If PuppeTor is used, the student should also be able to understand
en/volunteer.wml 128) and possibly extend an existing Java application. This project is partly
en/volunteer.wml 129) about design and partly about coding.
en/volunteer.wml 130) </li>
en/volunteer.wml 131) 
en/volunteer.wml 132) <li>
en/volunteer.wml 133) Implement a <a href="http://www.ss64.com/bash/top.html">top-like</a>
en/volunteer.wml 134) management tool for Tor relays. The purpose of such a tool would be
en/volunteer.wml 135) to monitor a local Tor relay via its control port and include useful
en/volunteer.wml 136) system information of the underlying machine. When running this tool, it
en/volunteer.wml 137) would dynamically update its content like top does for Linux processes.
en/volunteer.wml 138) <a href="http://archives.seul.org/or/dev/Jan-2008/msg00005.html">This
en/volunteer.wml 139) or-dev post</a> might be a good first read. The student should be familiar
en/volunteer.wml 140) with or willing to learn about administering a Tor relay and configuring
en/volunteer.wml 141) it via its control port. As an initial prototype is written in Python,
en/volunteer.wml 142) some knowledge about writing Python code would be helpful, too. This
en/volunteer.wml 143) project is for the one part about identifying requirements to such a
en/volunteer.wml 144) tool and designing its interface; but on the other part, the project
en/volunteer.wml 145) also requires a lot of coding.
en/volunteer.wml 146) </li>
en/volunteer.wml 147) 

en/volunteer.wml 148) <li>Help Mike Perry on his <a
en/volunteer.wml 149) href="https://www.torproject.org/svn/torflow/">TorFlow</a>
en/volunteer.wml 150) library (<a href="https://www.torproject.org/svn/torflow/TODO">TODO</a>):
en/volunteer.wml 151) it's a python library that uses the <a
en/volunteer.wml 152) href="https://www.torproject.org/svn/torctl/doc/howto.txt">Tor controller
en/volunteer.wml 153) protocol</a> to instruct Tor to build circuits in a variety of ways,
en/volunteer.wml 154) and then it measures performance and tries to detect anomalies.</li>
en/volunteer.wml 155) <li>Torflow / soat to detect bad relays and automatically get that
en/volunteer.wml 156) info to the directory authorities for realtime blacklisting</li>
en/volunteer.wml 157) <li>Torstatus. Set up an automated system for tracking network health
en/volunteer.wml 158) over time, graphing it, etc. Better metrics for assessing network
en/volunteer.wml 159) health and growth.</li>
en/volunteer.wml 160) <li>vidalia and upnp</li>
en/volunteer.wml 161) <li>nymble</li>
en/volunteer.wml 162) <li>polipo on windows</li>
en/volunteer.wml 163) <li>How can we make the <a
en/volunteer.wml 164) href="http://anonymityanywhere.com/incognito/">Incognito LiveCD</a>
en/volunteer.wml 165) easier to maintain, improve, and document?</li>
en/volunteer.wml 166) <li>We need a distributed testing framework. We have unit tests,
en/volunteer.wml 167) but it would be great to have a script that starts up a Tor network, uses
en/volunteer.wml 168) it for a while, and verifies that at least parts of it are working.</li>
en/volunteer.wml 169) 
en/volunteer.wml 170) <li>Don't like any of these? Look at the <a
en/volunteer.wml 171) href="<svnsandbox>doc/design-paper/roadmap-future.pdf">Tor development
en/volunteer.wml 172) roadmap</a> for more ideas.</li>
en/volunteer.wml 173) <li>Don't see your idea here? We probably need it anyway! Contact
en/volunteer.wml 174) us and find out.</li>
en/volunteer.wml 175) </ol>
en/volunteer.wml 176) 

en/volunteer.wml 177) <h2><a class="anchor" href="#Coding">Coding and Design</a></h2>

volunteer.html   178) <ol>

en/volunteer.wml 179) <li>Tor relays don't work well on Windows XP. On

en/volunteer.wml 180) Windows, Tor uses the standard <tt>select()</tt> system

en/volunteer.wml 181) call, which uses space in the non-page pool. This means

en/volunteer.wml 182) that a medium sized Tor relay will empty the non-page pool, <a

en/volunteer.wml 183) href="https://wiki.torproject.org/noreply/TheOnionRouter/WindowsBufferProblems">causing

en/volunteer.wml 184) havoc and system crashes</a>. We should probably be using overlapped IO

en/volunteer.wml 185) instead. One solution would be to teach <a
en/volunteer.wml 186) href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
en/volunteer.wml 187) overlapped IO rather than select() on Windows, and then adapt Tor to

en/volunteer.wml 188) the new libevent interface. Christian King made a
en/volunteer.wml 189) <a href="https://tor-svn.freehaven.net/svn/libevent-urz/trunk/">good
en/volunteer.wml 190) start</a> on this last summer.</li>

en/volunteer.wml 191) <li>We need to actually start building our <a href="<page
en/volunteer.wml 192) documentation>#DesignDoc">blocking-resistance design</a>. This involves

en/volunteer.wml 193) fleshing out the design, modifying many different pieces of Tor, adapting
en/volunteer.wml 194) <a href="http://vidalia-project.net/">Vidalia</a> so it supports the
en/volunteer.wml 195) new features, and planning for deployment.</li>

en/volunteer.wml 196) <li>We need a flexible simulator framework for studying end-to-end
en/volunteer.wml 197) traffic confirmation attacks. Many researchers have whipped up ad hoc
en/volunteer.wml 198) simulators to support their intuition either that the attacks work
en/volunteer.wml 199) really well or that some defense works great. Can we build a simulator
en/volunteer.wml 200) that's clearly documented and open enough that everybody knows it's
en/volunteer.wml 201) giving a reasonable answer? This will spur a lot of new research.
en/volunteer.wml 202) See the entry <a href="#Research">below</a> on confirmation attacks for
en/volunteer.wml 203) details on the research side of this task &mdash; who knows, when it's
en/volunteer.wml 204) done maybe you can help write a paper or three also.</li>

en/volunteer.wml 205) <li>Tor 0.1.1.x and later include support for hardware crypto accelerators

en/volunteer.wml 206) via OpenSSL. Nobody has ever tested it, though. Does somebody want to get

volunteer.html   207) a card and let us know how it goes?</li>

volunteer.html   208) <li>Perform a security analysis of Tor with <a
volunteer.html   209) href="http://en.wikipedia.org/wiki/Fuzz_testing">"fuzz"</a>. Determine

en/volunteer.wml 210) if there are good fuzzing libraries out there for what we want. Win fame by

volunteer.html   211) getting credit when we put out a new release because of you!</li>

volunteer.html   212) <li>Tor uses TCP for transport and TLS for link
volunteer.html   213) encryption. This is nice and simple, but it means all cells
volunteer.html   214) on a link are delayed when a single packet gets dropped, and
volunteer.html   215) it means we can only reasonably support TCP streams. We have a <a

en/volunteer.wml 216) href="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#TransportIPnotTCP">list

en/volunteer.wml 217) of reasons why we haven't shifted to UDP transport</a>, but it would
en/volunteer.wml 218) be great to see that list get shorter. We also have a proposed <a

en/volunteer.wml 219) href="<svnsandbox>doc/spec/proposals/100-tor-spec-udp.txt">specification
en/volunteer.wml 220) for Tor and

en/volunteer.wml 221) UDP</a> &mdash; please let us know what's wrong with it.</li>

volunteer.html   222) <li>We're not that far from having IPv6 support for destination addresses
volunteer.html   223) (at exit nodes). If you care strongly about IPv6, that's probably the
volunteer.html   224) first place to start.</li>

volunteer.html   225) </ol>
volunteer.html   226) 

en/volunteer.wml 227) <a id="Research"></a>
en/volunteer.wml 228) <h2><a class="anchor" href="#Research">Research</a></h2>

volunteer.html   229) <ol>

volunteer.html   230) <li>The "website fingerprinting attack": make a list of a few
volunteer.html   231) hundred popular websites, download their pages, and make a set of
volunteer.html   232) "signatures" for each site. Then observe a Tor client's traffic. As
volunteer.html   233) you watch him receive data, you quickly approach a guess about which
volunteer.html   234) (if any) of those sites he is visiting. First, how effective is
volunteer.html   235) this attack on the deployed Tor codebase? Then start exploring
volunteer.html   236) defenses: for example, we could change Tor's cell size from 512
volunteer.html   237) bytes to 1024 bytes, we could employ padding techniques like <a
volunteer.html   238) href="http://freehaven.net/anonbib/#timing-fc2004">defensive dropping</a>,
volunteer.html   239) or we could add traffic delays. How much of an impact do these have,
volunteer.html   240) and how much usability impact (using some suitable metric) is there from
volunteer.html   241) a successful defense in each case?</li>

volunteer.html   242) <li>The "end-to-end traffic confirmation attack":
volunteer.html   243) by watching traffic at Alice and at Bob, we can <a
volunteer.html   244) href="http://freehaven.net/anonbib/#danezis:pet2004">compare
volunteer.html   245) traffic signatures and become convinced that we're watching the same
volunteer.html   246) stream</a>. So far Tor accepts this as a fact of life and assumes this
volunteer.html   247) attack is trivial in all cases. First of all, is that actually true? How
volunteer.html   248) much traffic of what sort of distribution is needed before the adversary
volunteer.html   249) is confident he has won? Are there scenarios (e.g. not transmitting much)
volunteer.html   250) that slow down the attack? Do some traffic padding or traffic shaping
volunteer.html   251) schemes work better than others?</li>

volunteer.html   252) <li>The "routing zones attack": most of the literature thinks of
volunteer.html   253) the network path between Alice and her entry node (and between the
volunteer.html   254) exit node and Bob) as a single link on some graph. In practice,
volunteer.html   255) though, the path traverses many autonomous systems (ASes), and <a
volunteer.html   256) href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
volunteer.html   257) that the same AS appears on both the entry path and the exit path</a>.
volunteer.html   258) Unfortunately, to accurately predict whether a given Alice, entry,
volunteer.html   259) exit, Bob quad will be dangerous, we need to download an entire Internet
volunteer.html   260) routing zone and perform expensive operations on it. Are there practical
volunteer.html   261) approximations, such as avoiding IP addresses in the same /8 network?</li>

en/volunteer.wml 262) <li>Other research questions regarding geographic diversity consider
en/volunteer.wml 263) the tradeoff between choosing an efficient circuit and choosing a random

en/volunteer.wml 264) circuit. Look at Stephen Rollyson's <a

en/volunteer.wml 265) href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
en/volunteer.wml 266) paper</a> on how to discard particularly slow choices without hurting

en/volunteer.wml 267) anonymity "too much". This line of reasoning needs more work and more
en/volunteer.wml 268) thinking, but it looks very promising.</li>

en/volunteer.wml 269) <li>Tor doesn't work very well when relays have asymmetric bandwidth

volunteer.html   270) (e.g. cable or DSL). Because Tor has separate TCP connections between
volunteer.html   271) each hop, if the incoming bytes are arriving just fine and the outgoing
volunteer.html   272) bytes are all getting dropped on the floor, the TCP push-back mechanisms
volunteer.html   273) don't really transmit this information back to the incoming streams.
volunteer.html   274) Perhaps Tor should detect when it's dropping a lot of outgoing packets,
volunteer.html   275) and rate-limit incoming streams to regulate this itself? I can imagine
volunteer.html   276) a build-up and drop-off scheme where we pick a conservative rate-limit,
volunteer.html   277) slowly increase it until we get lost packets, back off, repeat. We
volunteer.html   278) need somebody who's good with networks to simulate this and help design
volunteer.html   279) solutions; and/or we need to understand the extent of the performance
volunteer.html   280) degradation, and use this as motivation to reconsider UDP transport.</li>
volunteer.html   281) <li>A related topic is congestion control. Is our
volunteer.html   282) current design sufficient once we have heavy use? Maybe
volunteer.html   283) we should experiment with variable-sized windows rather
volunteer.html   284) than fixed-size windows? That seemed to go well in an <a
volunteer.html   285) href="http://www.psc.edu/networking/projects/hpn-ssh/theory.php">ssh
volunteer.html   286) throughput experiment</a>. We'll need to measure and tweak, and maybe
volunteer.html   287) overhaul if the results are good.</li>

volunteer.html   288) <li>To let dissidents in remote countries use Tor without being blocked
volunteer.html   289) at their country's firewall, we need a way to get tens of thousands of
volunteer.html   290) relays, not just a few hundred. We can imagine a Tor client GUI that

en/volunteer.wml 291) has a "Tor for Freedom" button at the top that opens a port and relays a

volunteer.html   292) few KB/s of traffic into the Tor network. (A few KB/s shouldn't be too
volunteer.html   293) much hassle, and there are few abuse issues since they're not being exit
volunteer.html   294) nodes.) But how do we distribute a list of these volunteer clients to the
volunteer.html   295) good dissidents in an automated way that doesn't let the country-level
volunteer.html   296) firewalls intercept and enumerate them? Probably needs to work on a

en/volunteer.wml 297) human-trust level. See our <a href="<page documentation>#DesignDoc">early
en/volunteer.wml 298) blocking-resistance design document</a> and our
en/volunteer.wml 299) <a

en/volunteer.wml 300) href="https://wiki.torproject.org/noreply/TheOnionRouter/TorFAQ#BlockingResistance">FAQ

en/volunteer.wml 301) entry</a> on this, and then read the <a
en/volunteer.wml 302) href="http://freehaven.net/anonbib/topic.html#Communications_20Censorship">censorship
en/volunteer.wml 303) resistance section of anonbib</a>.</li>

volunteer.html   304) <li>Tor circuits are built one hop at a time, so in theory we have the
volunteer.html   305) ability to make some streams exit from the second hop, some from the
volunteer.html   306) third, and so on. This seems nice because it breaks up the set of exiting

en/volunteer.wml 307) streams that a given relay can see. But if we want each stream to be safe,

volunteer.html   308) the "shortest" path should be at least 3 hops long by our current logic, so
volunteer.html   309) the rest will be even longer. We need to examine this performance / security
volunteer.html   310) tradeoff.</li>

en/volunteer.wml 311) <li>It's not that hard to DoS Tor relays or directory authorities. Are client

volunteer.html   312) puzzles the right answer? What other practical approaches are there? Bonus
volunteer.html   313) if they're backward-compatible with the current Tor protocol.</li>

volunteer.html   314) </ol>
volunteer.html   315) 

en/volunteer.wml 316) <a href="<page contact>">Let us know</a> if you've made progress on any
en/volunteer.wml 317) of these!

volunteer.html   318) 

en/volunteer.wml 319)   </div><!-- #main -->

volunteer.html   320) 

en/volunteer.wml 321) #include <foot.wmi>