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

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

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

volunteer.html    10) <ol>

en/volunteer.wml  11) <li> Please consider <a href="<cvssandbox>tor/doc/tor-doc-server.html">running

volunteer.html    12) a server</a> to help the Tor network grow.</li>

en/volunteer.wml  13) <li> Take a look at the <a href="<page gui/index>">Tor GUI Competition</a>, and

volunteer.html    14) come up with ideas or designs to contribute to making Tor's interface
volunteer.html    15) and usability better. Free T-shirt for each submission!</li>
volunteer.html    16) <li> Tell your friends! Get them to run servers. Get them to run hidden
volunteer.html    17) services. Get them to tell their friends.</li>

en/volunteer.wml  18) <li> We are looking for funding and sponsors. If you like Tor, please
en/volunteer.wml  19)   <a href="<page donate>">take a moment to donate to support further
en/volunteer.wml  20)   Tor development</a>. Also, if you know any

en/volunteer.wml  21)   companies, NGOs, or other organizations that want communications
en/volunteer.wml  22)   security, let them know about us.</li>

volunteer.html    23) </ol>
volunteer.html    24) 

en/volunteer.wml  25) <a id="Installers"></a>
en/volunteer.wml  26) <h2><a class="anchor" href="#Installers">Installers</a></h2>

volunteer.html    27) <ol>

en/volunteer.wml  28) <li>Matt Edman has written a <a
en/volunteer.wml  29) href="http://freehaven.net/~edmanm/torcp/download.html">NSIS-based
en/volunteer.wml  30) Windows installer bundle that
en/volunteer.wml  31) includes Privoxy and TorCP</a>. Can you help make it more stable and
en/volunteer.wml  32) featureful?
en/volunteer.wml  33) </li>

volunteer.html    34) <li>Develop a way to handle OS X uninstallation

en/volunteer.wml  35) that is more automated than telling people to
en/volunteer.wml  36) <a href="<cvssandbox>tor/doc/tor-doc-osx.html#uninstall">manually remove

en/volunteer.wml  37) each file</a>. It needs to have a way to click it into action.</li>

en/volunteer.wml  38) <li>Our <a href="<cvssandbox>tor/tor.spec.in">RPM spec file</a>

volunteer.html    39) needs a maintainer, so we can get back to the business of writing Tor. If
volunteer.html    40) you have RPM fu, please help out.</li>
volunteer.html    41) </ol>
volunteer.html    42) 

en/volunteer.wml  43) <a id="Usability"></a>
en/volunteer.wml  44) <h2><a class="anchor" href="#Usability">Usability and Interface</a></h2>

volunteer.html    45) <ol>
volunteer.html    46) <li>We need a way to intercept DNS requests so they don't "leak" while
volunteer.html    47) we're trying to be anonymous. (This happens because the application does
volunteer.html    48) the DNS resolve before going to the SOCKS proxy.) One option is to use
volunteer.html    49) Tor's built-in support for doing DNS resolves; but you need to ask via
volunteer.html    50) our new socks extension for that, and no applications do this yet. A
volunteer.html    51) nicer option is to use Tor's controller interface: you intercept the
volunteer.html    52) DNS resolve, tell Tor about the resolve, and Tor replies with a dummy IP
volunteer.html    53) address. Then the application makes a connection through Tor to that dummy
volunteer.html    54) IP address, and Tor automatically maps it back to the original query.</li>
volunteer.html    55) <li>People running servers tell us they want to have one BandwidthRate
volunteer.html    56) during some part of the day, and a different BandwidthRate at other parts
volunteer.html    57) of the day. Rather than coding this inside Tor, we should have a little

en/volunteer.wml  58) script that speaks via the <a href="<page gui/index>">Tor Controller Interface</a>,

volunteer.html    59) and does a setconf to change the bandwidth rate. Perhaps it would run out
volunteer.html    60) of cron, or perhaps it would sleep until appropriate times and then do
volunteer.html    61) its tweak (that's probably more portable). Can somebody write one for us

en/volunteer.wml  62) and we'll put it into <a href="<cvssandbox>tor/contrib/">tor/contrib/</a>?</li>

volunteer.html    63) <li>We have a variety of ways to <a
volunteer.html    64) href="http://wiki.noreply.org/noreply/TheOnionRouter/TorFAQ#ChooseEntryExit">exit
volunteer.html    65) the Tor network from a particular country</a>, but they all
volunteer.html    66) require specifying the nickname of a particular Tor server. It
volunteer.html    67) would be nice to be able to specify just a country, and
volunteer.html    68) have something automatically pick. This requires having some
volunteer.html    69) component that knows what country each Tor node is in. The <a

en/volunteer.wml  70) href="http://serifos.eecs.harvard.edu/cgi-bin/exit.pl">script on

volunteer.html    71) serifos</a> manually parses whois entries for this. Maybe geolocation
volunteer.html    72) data will also work?</li>
volunteer.html    73) <li>Speaking of geolocation data, somebody should draw a map of the Earth
volunteer.html    74) with a pin-point for each Tor server. Bonus points if it updates as the
volunteer.html    75) network grows and changes.</li>
volunteer.html    76) <li>Tor provides anonymous connections, but we don't support
volunteer.html    77) keeping multiple pseudonyms in practice (say, in case you
volunteer.html    78) frequently go to two websites and if anybody knew about both of
volunteer.html    79) them they would conclude it's you). We should find a good approach
volunteer.html    80) and interface for handling pseudonymous profiles in Tor. See <a

volunteer.html    81) href="http://archives.seul.org/or/talk/Dec-2004/msg00086.html">this

volunteer.html    82) post</a> and <a
volunteer.html    83) href="http://archives.seul.org/or/talk/Jan-2005/msg00007.html">followup</a>
volunteer.html    84) for details.</li>

volunteer.html    85) </ol>
volunteer.html    86) 

en/volunteer.wml  87) <a id="Documentation"></a>
en/volunteer.wml  88) <h2><a class="anchor" href="#Documentation">Documentation</a></h2>

volunteer.html    89) <ol>

volunteer.html    90) <li>Please volunteer to help maintain this website: code, content,

volunteer.html    91) css, layout. Step one is to hang out on the IRC channel until we
volunteer.html    92) get to know you.</li>

volunteer.html    93) <li>We have too much documentation --- it's spread out too much and
volunteer.html    94) duplicates itself in places. Please send us patches, pointers, and
volunteer.html    95) confusions about the documentation so we can clean it up.</li>
volunteer.html    96) <li>Help translate the web page and documentation into other

en/volunteer.wml  97) languages. See the <a href="<page translation>">translation

volunteer.html    98) guidelines</a> if you want to help out. We also need people to help

en/volunteer.wml  99) maintain the existing Italian, French, and Swedish translations.</li>

volunteer.html   100) <li>Investigate privoxy vs. freecap vs. sockscap for win32 clients. Are
volunteer.html   101) there usability or stability issues that we can track down and
volunteer.html   102) resolve, or at least inform people about?</li>

volunteer.html   103) <li>Can somebody help Matt Edman with the documentation and how-tos
volunteer.html   104) for his <a href="http://freehaven.net/~edmanm/torcp/">Windows Tor

volunteer.html   105) Controller</a>?</li>

volunteer.html   106) <li>Evaluate, create, and <a
volunteer.html   107) href="http://wiki.noreply.org/wiki/TheOnionRouter/TorifyHOWTO">document
volunteer.html   108) a list of programs</a> that can be routed through Tor.</li>
volunteer.html   109) <li>We need better documentation for dynamically intercepting

en/volunteer.wml 110) connections and sending them through Tor. tsocks (Linux), dsocks (BSD),
en/volunteer.wml 111) and freecap (Windows) seem to be good candidates.</li>

en/volunteer.wml 112) <li>We have a huge list of <a href="<page support>">potentially useful

volunteer.html   113) programs that interface to Tor</a>. Which ones are useful in which
volunteer.html   114) situations? Please help us test them out and document your results.</li>
volunteer.html   115) </ol>
volunteer.html   116) 

en/volunteer.wml 117) <a id="Coding"></a>
en/volunteer.wml 118) <h2><a class="anchor" href="#Coding">Coding and Design</a></h2>

volunteer.html   119) <ol>
volunteer.html   120) <li>We recommend Privoxy as a good scrubbing web proxy, but it's
volunteer.html   121) unmaintained and still has bugs, especially on Windows. While we're at
volunteer.html   122) it, what sensitive information is not kept safe by Privoxy? Are there
volunteer.html   123) other scrubbing web proxies that are more secure?</li>
volunteer.html   124) <li>tsocks appears to be unmaintained: we have submitted several patches
volunteer.html   125) with no response. Can somebody volunteer to start maintaining a new
volunteer.html   126) tsocks branch? We'll help.</li>

volunteer.html   127) <li>Right now the hidden service descriptors are being stored on just a few
volunteer.html   128) directory servers. This is bad for privacy and bad for robustness. To get
volunteer.html   129) more robustness, we're going to need to make hidden service descriptors
volunteer.html   130) even less private because we're going to have to mirror them onto many
volunteer.html   131) places. Ideally we'd like to separate the storage/lookup system from the
volunteer.html   132) Tor directory servers entirely. Any reliable distributed storage system
volunteer.html   133) will do, as long as it allows authenticated updates. As far as we know,
volunteer.html   134) no implemented DHT code supports authenticated updates. What's the right
volunteer.html   135) next step?</li>
volunteer.html   136) <li>Tor exit servers need to do many DNS resolves in parallel. But
volunteer.html   137) gethostbyname() is poorly designed --- it blocks until it has finished

volunteer.html   138) resolving a query --- so it requires its own thread or process. So Tor
volunteer.html   139) is forced to spawn many separate DNS "worker" threads. There are some
volunteer.html   140) asynchronous DNS libraries out there, but historically they are buggy and

volunteer.html   141) abandoned. Are any of them stable, fast, clean, and free software? (Remember,
volunteer.html   142) Tor uses OpenSSL, and OpenSSL is (probably) not compatible with the GPL, so
volunteer.html   143) any GPL libraries are out of the running.) If so

volunteer.html   144) (or if we can make that so), we should integrate them into Tor. See <a

volunteer.html   145) href="http://archives.seul.org/or/talk/Sep-2005/msg00001.html">Agl's

volunteer.html   146) post</a> for one potential approach. Also see
volunteer.html   147) <a href="http://daniel.haxx.se/projects/c-ares/">c-ares</a> and
volunteer.html   148) <a href="http://www.monkey.org/~provos/libdnsres/">libdnsres</a>.
volunteer.html   149) </li>

volunteer.html   150) <li>Tor 0.1.1.x includes support for hardware crypto accelerators via
volunteer.html   151) OpenSSL. Nobody has ever tested it, though. Does somebody want to get
volunteer.html   152) a card and let us know how it goes?</li>

volunteer.html   153) <li>Long ago, we added dmalloc support to Tor, to track leaks. But we
volunteer.html   154) never quite got it working. Is dmalloc unfit for the job? Look at the
volunteer.html   155) --with-dmalloc configure option and go from there.</li>

volunteer.html   156) <li>Because Tor servers need to store-and-forward each cell they handle,
volunteer.html   157) high-bandwidth Tor servers end up using dozens of megabytes of memory
volunteer.html   158) just for buffers. We need better heuristics for when to shrink/expand
volunteer.html   159) buffers. Maybe this should be modelled after the Linux kernel buffer
volunteer.html   160) design, where you have many smaller buffers that link to each other,
volunteer.html   161) rather than monolithic buffers?</li>

volunteer.html   162) <li>How do ulimits work on Win32, anyway? We're having problems,

volunteer.html   163) especially on older Windowses with people running out of file
volunteer.html   164) descriptors, connection buffer space, etc. (We should handle
volunteer.html   165) WSAENOBUFS as needed, look at the MaxConnections registry entry,
volunteer.html   166) look at the MaxUserPort entry, and look at the TcpTimedWaitDelay
volunteer.html   167) entry. We may also want to provide a way to set them as needed. See <a

volunteer.html   168) href="http://bugs.noreply.org/flyspray/index.php?do=details&id=98">bug

volunteer.html   169) 98</a>.)</li>

volunteer.html   170) <li>Patches to Tor's autoconf scripts. First, we'd like our configure.in
volunteer.html   171) to handle cross-compilation, e.g. so we can build Tor for obscure

volunteer.html   172) platforms like the Linksys WRTG54. Second, we'd like the with-ssl-dir
volunteer.html   173) option to disable the search for ssl's libraries.</li>

volunteer.html   174) <li>Implement reverse DNS requests inside Tor (already specified in

en/volunteer.wml 175) Section 5.4 of <a href="<cvssandbox>tor/doc/tor-spec.txt">tor-spec.txt</a>).</li>

volunteer.html   176) <li>Perform a security analysis of Tor with <a
volunteer.html   177) href="http://en.wikipedia.org/wiki/Fuzz_testing">"fuzz"</a>. Determine

en/volunteer.wml 178) if there are good fuzzing libraries out there for what we want. Win fame by

volunteer.html   179) getting credit when we put out a new release because of you!</li>
volunteer.html   180) <li>How hard is it to patch bind or a DNS proxy to redirect requests to

volunteer.html   181) Tor via our <a href="http://wiki.noreply.org/noreply/TheOnionRouter/TorFAQ#CompatibleApplications">tor-resolve socks extension</a>? What about to convert UDP DNS

volunteer.html   182) requests to TCP requests and send them through Tor?</li>

volunteer.html   183) <li>Tor uses TCP for transport and TLS for link
volunteer.html   184) encryption. This is nice and simple, but it means all cells
volunteer.html   185) on a link are delayed when a single packet gets dropped, and
volunteer.html   186) it means we can only reasonably support TCP streams. We have a <a
volunteer.html   187) href="http://wiki.noreply.org/noreply/TheOnionRouter/TorFAQ#TransportIPnotTCP">list
volunteer.html   188) of reasons why we haven't shifted to UDP transport</a>, but it would be

volunteer.html   189) great to see that list get shorter.</li>

volunteer.html   190) <li>We're not that far from having IPv6 support for destination addresses
volunteer.html   191) (at exit nodes). If you care strongly about IPv6, that's probably the
volunteer.html   192) first place to start.</li>

volunteer.html   193) </ol>
volunteer.html   194) 

en/volunteer.wml 195) <a id="Research"></a>
en/volunteer.wml 196) <h2><a class="anchor" href="#Research">Research</a></h2>

volunteer.html   197) <ol>

volunteer.html   198) <li>The "website fingerprinting attack": make a list of a few
volunteer.html   199) hundred popular websites, download their pages, and make a set of
volunteer.html   200) "signatures" for each site. Then observe a Tor client's traffic. As
volunteer.html   201) you watch him receive data, you quickly approach a guess about which
volunteer.html   202) (if any) of those sites he is visiting. First, how effective is
volunteer.html   203) this attack on the deployed Tor codebase? Then start exploring
volunteer.html   204) defenses: for example, we could change Tor's cell size from 512
volunteer.html   205) bytes to 1024 bytes, we could employ padding techniques like <a
volunteer.html   206) href="http://freehaven.net/anonbib/#timing-fc2004">defensive dropping</a>,
volunteer.html   207) or we could add traffic delays. How much of an impact do these have,
volunteer.html   208) and how much usability impact (using some suitable metric) is there from
volunteer.html   209) a successful defense in each case?</li>

volunteer.html   210) <li>The "end-to-end traffic confirmation attack":
volunteer.html   211) by watching traffic at Alice and at Bob, we can <a
volunteer.html   212) href="http://freehaven.net/anonbib/#danezis:pet2004">compare
volunteer.html   213) traffic signatures and become convinced that we're watching the same
volunteer.html   214) stream</a>. So far Tor accepts this as a fact of life and assumes this
volunteer.html   215) attack is trivial in all cases. First of all, is that actually true? How
volunteer.html   216) much traffic of what sort of distribution is needed before the adversary
volunteer.html   217) is confident he has won? Are there scenarios (e.g. not transmitting much)
volunteer.html   218) that slow down the attack? Do some traffic padding or traffic shaping
volunteer.html   219) schemes work better than others?</li>

volunteer.html   220) <li>The "routing zones attack": most of the literature thinks of
volunteer.html   221) the network path between Alice and her entry node (and between the
volunteer.html   222) exit node and Bob) as a single link on some graph. In practice,
volunteer.html   223) though, the path traverses many autonomous systems (ASes), and <a
volunteer.html   224) href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
volunteer.html   225) that the same AS appears on both the entry path and the exit path</a>.
volunteer.html   226) Unfortunately, to accurately predict whether a given Alice, entry,
volunteer.html   227) exit, Bob quad will be dangerous, we need to download an entire Internet
volunteer.html   228) routing zone and perform expensive operations on it. Are there practical
volunteer.html   229) approximations, such as avoiding IP addresses in the same /8 network?</li>

volunteer.html   230) <li>Tor doesn't work very well when servers have asymmetric bandwidth
volunteer.html   231) (e.g. cable or DSL). Because Tor has separate TCP connections between
volunteer.html   232) each hop, if the incoming bytes are arriving just fine and the outgoing
volunteer.html   233) bytes are all getting dropped on the floor, the TCP push-back mechanisms
volunteer.html   234) don't really transmit this information back to the incoming streams.
volunteer.html   235) Perhaps Tor should detect when it's dropping a lot of outgoing packets,
volunteer.html   236) and rate-limit incoming streams to regulate this itself? I can imagine
volunteer.html   237) a build-up and drop-off scheme where we pick a conservative rate-limit,
volunteer.html   238) slowly increase it until we get lost packets, back off, repeat. We
volunteer.html   239) need somebody who's good with networks to simulate this and help design
volunteer.html   240) solutions; and/or we need to understand the extent of the performance
volunteer.html   241) degradation, and use this as motivation to reconsider UDP transport.</li>
volunteer.html   242) <li>A related topic is congestion control. Is our
volunteer.html   243) current design sufficient once we have heavy use? Maybe
volunteer.html   244) we should experiment with variable-sized windows rather
volunteer.html   245) than fixed-size windows? That seemed to go well in an <a
volunteer.html   246) href="http://www.psc.edu/networking/projects/hpn-ssh/theory.php">ssh
volunteer.html   247) throughput experiment</a>. We'll need to measure and tweak, and maybe
volunteer.html   248) overhaul if the results are good.</li>

volunteer.html   249) <li>To let dissidents in remote countries use Tor without being blocked
volunteer.html   250) at their country's firewall, we need a way to get tens of thousands of
volunteer.html   251) relays, not just a few hundred. We can imagine a Tor client GUI that
volunteer.html   252) has a "help China" button at the top that opens a port and relays a
volunteer.html   253) few KB/s of traffic into the Tor network. (A few KB/s shouldn't be too
volunteer.html   254) much hassle, and there are few abuse issues since they're not being exit
volunteer.html   255) nodes.) But how do we distribute a list of these volunteer clients to the
volunteer.html   256) good dissidents in an automated way that doesn't let the country-level
volunteer.html   257) firewalls intercept and enumerate them? Probably needs to work on a

en/volunteer.wml 258) human-trust level. See our <a
en/volunteer.wml 259) href="http://wiki.noreply.org/noreply/TheOnionRouter/TorFAQ#China">FAQ
en/volunteer.wml 260) entry</a> on this, and then read the <a
en/volunteer.wml 261) href="http://freehaven.net/anonbib/topic.html#Communications_20Censorship">censorship
en/volunteer.wml 262) resistance section of anonbib</a>.</li>

volunteer.html   263) <li>Tor circuits are built one hop at a time, so in theory we have the
volunteer.html   264) ability to make some streams exit from the second hop, some from the
volunteer.html   265) third, and so on. This seems nice because it breaks up the set of exiting
volunteer.html   266) streams that a given server can see. But if we want each stream to be safe,
volunteer.html   267) the "shortest" path should be at least 3 hops long by our current logic, so
volunteer.html   268) the rest will be even longer. We need to examine this performance / security
volunteer.html   269) tradeoff.</li>
volunteer.html   270) <li>It's not that hard to DoS Tor servers or dirservers. Are client
volunteer.html   271) puzzles the right answer? What other practical approaches are there? Bonus
volunteer.html   272) if they're backward-compatible with the current Tor protocol.</li>

volunteer.html   273) </ol>
volunteer.html   274) 
volunteer.html   275) Drop by the #tor IRC channel at irc.oftc.net or email tor-volunteer@freehaven.net if you want to help out!
volunteer.html   276) 

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