getinvolved/en/volunteer.wml (5c8c2cfb9) - tor-webwml.git

volunteer.wml

## translation metadata
# Revision: $Revision$
# Translation-Priority: 4-optional

#include "head.wmi" TITLE="Tor: Volunteer" CHARSET="UTF-8"
<div id="content" class="clearfix">
  <div id="breadcrumbs">
    <a href="<page index>">Home &raquo; </a>
    <a href="<page getinvolved/volunteer>">Volunteer</a>
  </div>
  <div id="maincol">
    
    <h1>A few things everyone can do now:</h1>
    <ol>
    <li>Please consider <a href="<page docs/tor-doc-relay>">running
    a relay</a> to help the Tor network grow.</li>
    <li>Tell your friends! Get them to run relays. Get them to run hidden
    services. Get them to tell their friends.</li>
    <li>If you like Tor's goals, please <a href="<page donate/donate>">take a moment
    to donate to support further Tor development</a>. We're also looking
    for more sponsors &mdash; if you know any companies, NGOs, agencies,
    or other organizations that want anonymity / privacy / communications
    security, let them know about us.</li>
    <li>We're looking for more <a href="<page about/torusers>">good examples of Tor
    users and Tor use cases</a>. If you use Tor for a scenario or purpose not
    yet described on that page, and you're comfortable sharing it with us,
    we'd love to hear from you.</li>
    </ol>

<a id="Documentation"></a>
    <h2><a class="anchor" href="#Documentation">Documentation</a></h2>
    <ol>
    <li>Help translate the

    documentation into other
    languages. See the <a href="<page getinvolved/translation>">translation
    guidelines</a> if you want to help out. We especially need Arabic or
    Farsi translations, for the many Tor users in censored areas.</li>
    <li>Evaluate and document
    <a href="<wiki>doc/TorifyHOWTO">our
    list of programs</a> that can be configured to use Tor.</li>
    <li>We have a huge list of <a
    href="<wiki>doc/SupportPrograms">potentially useful
    programs that interface with Tor</a>. Which ones are useful in which
    situations? Please help us test them out and document your results.</li>
    </ol>

<a id="Advocacy"></a>
    <h2><a class="anchor" href="#Advocacy">Advocacy</a></h2>
    <ol>
    <li>Monitor some of our <a 
    href="https://lists.torproject.org/cgi-bin/mailman/listinfo">public mailing 
    lists</a>, like <a 
    href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-talk">tor-talk</a>, <a 
    href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-relays">tor-relays</a>, <a 
    href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev">tor-dev</a>, or <a 
    href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tbb-dev">tbb-dev</a>, 
    and summarize noteworthy exchanges into articles for <a 
    href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-news">Tor 
    Weekly News</a>.</li>
    <li>Create a presentation that can be used for various user group
meetings around the world.</li>
    <li>Create a video about the positive uses of Tor, what Tor is,
    or how to use it.  Some have already started on <a
    href="https://media.torproject.org/video/">Tor's Media server</a>,
    <a
    href="http://www.howcast.com/videos/90601-How-To-Circumvent-an-Internet-Proxy">Howcast</a>,
    and <a href="http://www.youtube.com/thetorproject">YouTube</a>.</li>
    <li>Create a poster around a theme, such as "Tor for Freedom!"</li>
    <li>Create a t-shirt design that incorporates "<a
    href="https://check.torproject.org/">Congratulations! You are using
    Tor!</a>" in any language.</li>
    <li>Spread the word about Tor at a symposium or conference and use these
    <a href="https://media.torproject.org/misc/2015-03-tor-brochure/">Tor
    brochures</a> in PDF and ODG format and translated to at least ten
    different languages as conversation starter.</li>
    </ol>

<!--
    <a id="gsoc"></a>
    <h2><a class="anchor" href="#gsoc">Google Summer of Code</a></h2>

<p>
    Tor is also taking part in this year's <a
    href="https://www.google-melange.com/gsoc/homepage/google/gsoc2013">Google
    Summer of Code</a>! The criteria for this is a little different - either
    gender can apply but you need to be either <a
    href="https://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2013/help_page#2._Whos_eligible_to_participate_as_a">a
    present student or just graduated</a>.
    </p>

<p>
    As mentioned above if you're eligible for either program then please apply
    for both! Google Summer of Code is a far, far larger program for us than
    OPW so your chances of being applied that way are considerably better.
    </p>

<p>
    <b>See our page for <a href="<page about/gsoc>">Google Summer of Code</a>
    for more information.</b>
    </p>
-->

<a id="Projects"></a>
    <h2><a class="anchor" href="#Projects">Projects</a></h2>

<p>
    Below are a list of Tor related projects we're developing and/or
    maintaining. Most discussions happen on IRC so if you're interested in any
    of these (or you have a project idea of your own), then please <a
    href="<page about/contact>#irc">join us in #tor-dev</a>. Don't be shy
    to ask questions, and don't hesitate to ask even if the main contributors
    aren't active at that moment.
    </p>

<p>
    For a presentation summarizing many of these projects see...
    </p>

<div id="ecosystem_presentation">
      <a href="https://www.youtube.com/watch?v=fb6iqZcQsSg">Tor Ecosystem</a> (<a href="https://media.torproject.org/video/2013-11-t3am-damian-johnson.mp4">mp4</a>, <a href="https://svn.torproject.org/svn/projects/presentations/2013-11-t3am-tor-ecosystem.pdf">slides</a>)
    </div>

<table id="projects">
      <tr>
        <th>Name</th>
        <th>Category</th>
        <th>Language</th>
        <th>Activity</th>
        <th>Contributors</th>
      </tr>

<tr>
        <td><a href="#project-tor">Tor</a></td>
        <td>Core</td>
        <td>C</td>
        <td>Heavy</td>
        <td>nickm, athena, arma</td>
      </tr>

<tr>
        <td><a href="#project-torbrowser">Tor Browser</a></td>
        <td>Bundle</td>
        <td>Javascript, XUL, Scripting</td>
        <td>Heavy</td>
        <td>mikeperry, Pearl Crescent</td>
      </tr>

<tr>
        <td><a href="#project-httpseverywhere">HTTPS Everywhere</a></td>
        <td>Browser Add-on</td>
        <td>Javascript</td>
        <td>Heavy</td>
        <td>pde, mikeperry</td>
      </tr>

<tr>
        <td><a href="#project-nyx">Nyx</a></td>
        <td>User Interface</td>
        <td>Python, Curses</td>
        <td>Heavy</td>
        <td>atagar</td>
      </tr>

<tr>
        <td><a href="#project-orbot">Orbot</a></td>
        <td>User Interface</td>
        <td>Java</td>
        <td>Moderage</td>
        <td>n8fr8</td>
      </tr>

<tr>
        <td><a href="#project-tails">Tails</a></td>
        <td>OS image</td>
        <td>Sys Admin</td>
        <td>Heavy</td>
        <td><a href="https://tails.boum.org/">#tails</a></td>
      </tr>

<tr>
        <td><a href="#project-torramdisk">tor-ramdisk</a></td>
        <td>OS image</td>
        <td>Sys Admin</td>
        <td>Light</td>
        <td>blueness</td>
      </tr>

<tr>
        <td><a href="#project-torsocks">Torsocks</a></td>
        <td>Usability</td>
        <td>C</td>
        <td>Light</td>
        <td>David Goulet</td>
      </tr>

<tr>
        <td><a href="#project-tormessenger">Tor Messenger</a></td>
        <td>Bundle</td>
        <td>JavaScript, XUL, Scripting</td>
        <td>Heavy</td>
        <td>arlolra, boklm, sukhe</td>
      </tr>

<tr>
        <td><a href="#project-torbirdy">TorBirdy</a></td>
        <td>Browser Add-on</td>
        <td>JavaScript</td>
        <td>Light</td>
        <td>sukhe</td>
      </tr>

<tr>
        <td><a href="#project-obfsproxy">Obfsproxy</a></td>
        <td>Client Add-on</td>
        <td>Python</td>
        <td>None</td>
        <td>asn</td>
      </tr>

<tr>
        <td><a href="#project-flash-proxy">Flash Proxy</a></td>
        <td>Client Add-on</td>
        <td>Python, JavaScript, Go</td>
        <td>Light</td>
        <td>dcf, infinity0, Arlo Breault</td>
      </tr>

<tr>
        <td><a href="#project-shadow">Shadow</a></td>
        <td>Simulator</td>
        <td>C, Python</td>
        <td>Heavy</td>
        <td>robgjansen</td>
      </tr>

<tr>
        <td><a href="#project-chutney">Chutney</a></td>
        <td>Simulator</td>
        <td>Python</td>
        <td>Light</td>
        <td>nickm</td>
      </tr>

<tr>
        <td><a href="#project-stem">Stem</a></td>
        <td>Library</td>
        <td>Python</td>
        <td>Heavy</td>
        <td>atagar</td>
      </tr>

<tr>
        <td><a href="#project-txtorcon">Txtorcon</a></td>
        <td>Library</td>
        <td>Python, Twisted</td>
        <td>Light</td>
        <td>meejah</td>
      </tr>

<tr>
        <td><a href="#project-tlsdate">Tlsdate</a></td>
        <td>Utility</td>
        <td>C</td>
        <td>None</td>
        <td>ioerror</td>
      </tr>

<tr>
        <td><a href="#project-metrics">Metrics</a></td>
        <td>Client Service</td>
        <td>Java</td>
        <td>Moderate</td>
        <td>karsten</td>
      </tr>

<tr>
        <td><a href="#project-atlas">Atlas</a></td>
        <td>Client Service</td>
        <td>JavaScript</td>
        <td>None</td>
        <td></td>
      </tr>

<tr>
        <td><a href="#project-globe">Globe</a></td>
        <td>Client Service</td>
        <td>JavaScript</td>
        <td>None</td>
        <td></td>
      </tr>

<tr>
        <td><a href="#project-compass">Compass</a></td>
        <td>Client Service</td>
        <td>Python</td>
        <td>None</td>
        <td></td>
      </tr>

<tr>
        <td><a href="#project-onionoo">Onionoo</a></td>
        <td>Backend Service</td>
        <td>Java</td>
        <td>Light</td>
        <td>karsten</td>
      </tr>

<tr>
        <td><a href="#project-exitmap">ExitMap</a></td>
        <td>Backend Service</td>
        <td>Python</td>
        <td>Light</td>
        <td>phw</td>
      </tr>

<tr>
        <td><a href="#project-doctor">DocTor</a></td>
        <td>Backend Service</td>
        <td>Python</td>
        <td>Light</td>
        <td>atagar</td>
      </tr>

<tr>
        <td><a href="#project-weather">Weather</a></td>
        <td>Client Service</td>
        <td>Python</td>
        <td>None</td>
        <td>kaner</td>
      </tr>

<tr>
        <td><a href="#project-gettor">GetTor</a></td>
        <td>Client Service</td>
        <td>Python</td>
        <td>Light</td>
        <td>ilv</td>
      </tr>

<tr>
        <td><a href="#project-torcheck">TorCheck</a></td>
        <td>Client Service</td>
        <td>Go</td>
        <td>None</td>
        <td>Arlo</td>
      </tr>

<tr>
        <td><a href="#project-bridgedb">BridgeDB</a></td>
        <td>Backend Service</td>
        <td>Python</td>
        <td>Light</td>
        <td>isis</td>
      </tr>

<tr>
        <td><a href="#project-ooni-probe">Ooni Probe</a></td>
        <td>Scanner</td>
        <td>Python</td>
        <td>Moderate</td>
        <td>hellais, aagbsn</td>
      </tr>

<tr>
        <td><a href="#project-torps">TorPS</a></td>
        <td>Backend Service</td>
        <td>Python</td>
        <td>None</td>
        <td>Aaron Johnson</td>
      </tr>

<tr>
        <td><a href="#project-torflow">TorFlow</a></td>
        <td>Backend Service</td>
        <td>Python</td>
        <td>None</td>
        <td>aagbsn</td>
      </tr>

<tr>
        <td><a href="#project-tor2web">Tor2web</a></td>
        <td>Client Service</td>
        <td>Python</td>
        <td>Heavy</td>
        <td>evilaliv3, hellais</td>
      </tr>

<tr>
        <td><a href="#project-anonbib">Anonbib</a></td>
        <td>Website</td>
        <td>Python</td>
        <td>Light</td>
        <td>arma, nickm</td>
      </tr>
    </table>

<sub>
    * Project is still in an alpha state.
    </sub>

<a id="project-tor"></a>
    <h3>Tor (<a href="https://gitweb.torproject.org/tor.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/report/12">bug
    tracker</a>)</h3>

<p>
    Central project, providing the core software for using and participating in
    the Tor network. Numerous people contribute to the project to varying
    extents, but the chief architects are Nick Mathewson and Roger Dingledine.
    </p>

<p>
    <b>Project Ideas:</b><br />
    <i><a href="#torCleanup">Tor Codebase Cleanup</a></i><br />
    <i><a href="#improveTorTestCoverage">Improve test coverage in Tor</a></i><br />
    <i><a href="#useMoreCores">Have the Tor daemon use more cores</a></i><br />
    <i><a href="#improveHiddenServices">Help improve Tor hidden services</a></i><br />
    <i><a href="#improvedDnsSupport">Improved DNS support for Tor</a></i>
    </p>

<a id="project-torbrowser"></a>
    <h3><a href="<page projects/torbrowser>">Tor Browser</a> (<a
    href="https://gitweb.torproject.org/tor-browser.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torbutton&component=Tor+Launcher&component=Tor+Browser&component=Tor+bundles%2Finstallation&col=id&col=summary&col=status&col=owner&col=type&col=priority&col=milestone&order=priority">bug
    tracker</a>, <a href="https://www.torproject.org/projects/torbrowser/design/">design doc</a>)</h3>

<p>
    Tor Browser is an easy-to-use, portable package of Tor, HTTPS-Everywhere, 
    NoScript, TorLauncher, Torbutton, and a Firefox fork, all  preconfigured 
    to work together out of
    the box. The modified copy of Firefox aims to resolve the
    privacy and security issues in mainline version.
    </p>

<a id="project-httpseverywhere"></a>
    <h3><a href="https://www.eff.org/https-everywhere">HTTPS Everywhere</a> (<a
    href="https://gitweb.torproject.org/https-everywhere.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/report/19">bug
    tracker</a>)</h3>

<p>
    HTTPS Everywhere is a Firefox and Chrome extension that encrypts
    your communications with many major websites, making your browsing
    more secure.
    </p>

<a id="project-nyx"></a>
    <h3><a href="https://www.atagar.com/arm/">Nyx</a> (<a
    href="https://gitweb.torproject.org/nyx.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=arm&order=priority">bug
    tracker</a>)</h3>

<p>
    Nyx (previously <i>arm</i>) is a terminal status monitor for Tor
    intended for command-line aficionados, ssh connections, and anyone with a
    tty terminal. This works much like top does for system usage, providing
    real time statistics for bandwidth, resource usage, connections, and quite
    a bit more.
    </p>

<a id="project-orbot"></a>
    <h3><a href="https://guardianproject.info/apps/orbot/">Orbot</a> (<a
    href="https://gitweb.torproject.org/orbot.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Orbot&order=priority">bug
    tracker</a>)</h3>

<p>
    Provides Tor on the Android platform. The project is under active 
    development, updates to latest Tor releases, and working to stay up to 
    date with all changes in Android and mobile threats.
    </p>

<a id="project-tails"></a>
    <h3><a href="https://tails.boum.org/">The Amnesic Incognito Live System</a> (<a
    href="https://git-tails.immerda.ch/tails/">code</a>, <a
    href="https://labs.riseup.net/code/projects/tails">bug
    tracker</a>, <a href="https://tails.boum.org/doc">documentation</a>, <a
    href="https://tails.boum.org/contribute/design/">design</a>, <a
    href="https://tails.boum.org/contribute">contribute</a>)</h3>

<p>
    The Amnesic Incognito Live System is a live CD/USB distribution
    preconfigured so that everything is safely routed through Tor and leaves no
    trace on the local system. This is a merger of the Amnesia and <a
    href="http://www.anonymityanywhere.com/incognito/">Incognito</a> projects,
    and still under very active development.
    </p>

<a id="project-torramdisk"></a>
    <h3><a href="http://opensource.dyc.edu/tor-ramdisk">Tor-ramdisk</a> (<a
    href="https://gitweb.torproject.org/tor-ramdisk.git">code</a>, <a
    href="http://opensource.dyc.edu/tor-ramdisk-documentation">documentation</a>)</h3>

<p>
    Tor-ramdisk is a uClibc-based micro Linux distribution whose sole
    purpose is to securely host a Tor server purely in RAM.
    </p>

<a id="project-torsocks"></a>
    <h3>Torsocks (<a
    href="https://gitweb.torproject.org/torsocks.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torify&order=priority">bug
    tracker</a>)</h3>

<p>
    Utility for adapting other applications to work with Tor. Development has
    slowed and compatibility issues remain with some platforms, but it's
    otherwise feature complete.
    </p>

<a id="project-tormessenger"></a>
    <h3><a href="https://trac.torproject.org/projects/tor/wiki/doc/TorMessenger">Tor Messenger</a> (<a
    href="https://gitweb.torproject.org/tor-messenger-build.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=!closed&component=Tor+Messenger">bug tracker</a>)</h3>

<p>
    Tor Messenger is a cross-platform chat program that aims to be secure by default and sends all of its traffic over Tor.
    </p>

<a id="project-torbirdy"></a>
    <h3>TorBirdy (<a
    href="https://gitweb.torproject.org/torbirdy.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/wiki/torbirdy/dev">bug
    tracker</a>)</h3>

<p>
    TorBirdy is Torbutton for Thunderbird and related Mozilla mail clients.
    </p>

<p>
    <b>Project Ideas:</b><br />
    <i><a href="#makeTorbirdyBetter">Make TorBirdy Better</a></i>
    </p>

<a id="project-obfsproxy"></a>
    <h3><a href="<page projects/obfsproxy>">Obfsproxy</a> (<a
    href="https://gitweb.torproject.org/pluggable-transports/obfsproxy.git">code</a>,
    <a href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Pluggable+transport&order=priority">bug
    tracker</a>)</h3>

<p>
    A proxy that shapes Tor traffic, making it harder for censors to detect and
    block Tor. This has both a C and python implementation.
    </p>

<p>
    <b>Project Ideas:</b><br />
    <i><a href="https://trac.torproject.org/projects/tor/wiki/doc/PluggableTransports#Helpneeded">Various coding tasks</a></i> <br/>
    <i><a href="#betterPluggableTransports">Build Better Pluggable Transports</a></i>
    </p>

<a id="project-flash-proxy"></a>
    <h3><a href="https://crypto.stanford.edu/flashproxy/">Flash Proxy</a> (<a
    href="https://gitweb.torproject.org/flashproxy.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_information&status=needs_review&status=needs_revision&status=new&status=reopened&component=Flashproxy">bug
    tracker</a>)</h3>

<p>
    Pluggable transport using proxies running in web browsers to defeat
    address-based blocking.
    </p>

<a id="project-chutney"></a>
    <h3>Chutney (<a href="https://gitweb.torproject.org/chutney.git">code</a>,
    <a href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_information&status=needs_review&status=needs_revision&status=new&status=reopened&component=Chutney">bug
    tracker</a>)</h3>

<p>
    Integration test suite that spawns a local tor network, checking the
    interactions of its components.
    </p>

<a id="project-shadow"></a>
    <h3><a href="https://shadow.cs.umn.edu/">Shadow</a> (<a
    href="https://github.com/shadow">code</a>, <a
    href="https://github.com/shadow/shadow/issues">bug
    tracker</a>)</h3>

<p>
    Shadow is a discrete-event network simulator that runs the real
    Tor software as a plug-in. Shadow is open-source software that enables
    accurate, efficient, controlled, and repeatable Tor experimentation.
    For another simulator, see <a
    href="http://crysp.uwaterloo.ca/software/exptor/">ExperimenTor</a>.
    </p>

<a id="project-stem"></a>
    <h3><a href="https://stem.torproject.org/">Stem</a> (<a
    href="https://gitweb.torproject.org/stem.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/wiki/doc/stem/bugs">bug
    tracker</a>)</h3>

<p>
    Python controller library for scripts and controller applications using
    Tor.
    </p>

<a id="project-txtorcon"></a>
    <h3><a href="https://txtorcon.readthedocs.org">Txtorcon</a> (<a
    href="https://github.com/meejah/txtorcon">code</a>, <a
    href="https://github.com/meejah/txtorcon/issues">bug tracker</a>)</h3>

<p>
    Twisted-based asynchronous Tor control protocol implementation. Includes
    unit-tests, examples, state-tracking code and configuration abstraction.
    Used by OONI and APAF.
    </p>

<a id="project-tlsdate"></a>
    <h3>Tlsdate (<a href="https://github.com/ioerror/tlsdate">code</a>)</h3>

<p>
    tlsdate: secure parasitic rdate replacement
    </p>

<p>
    tlsdate sets the local clock by securely connecting with TLS to remote
    servers and extracting the remote time out of the secure handshake. Unlike
    ntpdate, tlsdate uses TCP, for instance connecting to a remote HTTPS or TLS
    enabled service, and provides some protection against adversaries that try
    to feed you malicious time information.
    </p>

<a id="project-metrics"></a>
    <h3><a href="https://metrics.torproject.org/">Metrics</a> (code: <a
    href="https://gitweb.torproject.org/metrics-db.git">db</a>, <a
    href="https://gitweb.torproject.org/metrics-web.git">web</a>)</h3>

<p>
    Processing and analytics of consensus data, provided to users via the
    metrics portal. This has been under active development for several years by
    Karsten Loesing. See also <a
    href="https://gitweb.torproject.org/torperf.git">TorPerf</a>.
    </p>

<a id="project-atlas"></a>
    <h3><a href="https://atlas.torproject.org/">Atlas</a> (<a
    href="https://gitweb.torproject.org/atlas.git">code</a>)</h3>

<p>
    Atlas is a web application to discover Tor relays and bridges. It provides
    useful information on how relays are configured along with graphics about
    their past usage.
    </p>

<p>
    This is the spiritual successor to <a
    href="https://gitweb.torproject.org/torstatus.git">TorStatus</a>, the <a
    href="https://svn.torproject.org/svn/torstatus/trunk/">original
    codebase</a> for which was written in PHP, and rewritten by students from
    Wesleyan as Django.
    </p>

<a id="project-globe"></a>
    <h3><a href="http://globe.rndm.de/">Globe</a> (<a
    href="https://github.com/makepanic/globe">code</a>, <a
    href="https://github.com/makepanic/globe/issues">bug tracker</a>)</h3>

<p>
    Globe is a web application that allows you to search for Tor relays and
    bridges. It gives you a detailed overview of properties and configurations
    of a relay or bridge.
    </p>

<a id="project-compass"></a>
    <h3><a href="https://compass.torproject.org/">Compass</a> (<a
    href="https://gitweb.torproject.org/compass.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Compass&order=priority">bug
    tracker</a>)</h3>

<p>
    Compass is a web and command line application that filters and
    aggregates the Tor relays based on various attributes.
    </p>

<a id="project-onionoo"></a>
    <h3><a href="https://onionoo.torproject.org/">Onionoo</a> (<a
    href="https://gitweb.torproject.org/onionoo.git">code</a>,
    <a href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Onionoo&order=priority">bug tracker</a>)</h3>

<p>
    Onionoo is a JSON based protocol to learn information about currently
    running Tor relays and bridges.
    </p>

<a id="project-exitmap"></a>
    <h3><a href="http://www.cs.kau.se/philwint/spoiled_onions/">ExitMap</a> (<a
    href="https://github.com/NullHypothesis/exitmap">code</a>, <a
    href="https://github.com/NullHypothesis/exitmap/issues">bug tracker</a>)</h3>

<p>
    Scanner for the Tor network by Philipp Winter to detect malicious and
    misconfigured exits. For more information about how it works see his <a
    href="http://www.cs.kau.se/philwint/spoiled_onions/pets2014.pdf">Spoiled
    Onions</a> research paper.
    </p>

<p>
    <b>Project Ideas:</b><br />
    <i><a href="#exitmap_improvements">Exitmap Improvements</a></i>
    </p>

<a id="project-doctor"></a>
    <h3>DocTor (<a
    href="https://gitweb.torproject.org/doctor.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=DocTor&order=priority">bug
    tracker</a>)</h3>

<p>
    DocTor is a notification service that monitors newly published descriptor
    information for issues. This is primarily a service to help the tor
    directory authority operators, but it also checks for a handful of other
    issues like sybil attacks.
    </p>

<a id="project-weather"></a>
    <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/Weather">Weather</a> (<a
    href="https://gitweb.torproject.org/weather.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+Weather&order=priority">bug
    tracker</a>)</h3>

<p>
    Provides automatic notification to subscribed relay operators when their
    relay's unreachable. This underwent a rewrite by the <a
    href="http://hfoss.wesleyan.edu/">Wesleyan HFOSS team</a>, which went live
    in early 2011.
    </p>

<a id="project-gettor"></a>
    <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/GetTor">GetTor</a> (<a
    href="https://gitweb.torproject.org/gettor.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=GetTor&order=priority">bug
    tracker</a>)</h3>

<p>
    E-mail autoresponder providing Tor's packages over SMTP. This has been
    relatively unchanged for quite a while.
    </p>

<a id="project-torcheck"></a>
    <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorCheck">TorCheck</a> (<a
    href="https://gitweb.torproject.org/check.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+Check&order=priority">bug
    tracker</a>)</h3>

<p>
    Site for determining if the visitor is using Tor or not.
    </p>

<a id="project-bridgedb"></a>
    <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/BridgeDB">BridgeDB</a> (<a
    href="https://gitweb.torproject.org/bridgedb.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=BridgeDB&order=priority">bug
    tracker</a>)</h3>

<p>
    Backend bridge distributor, handling the various pools they're distributed
    in. This was actively developed until Fall of 2010.
    </p>

<a id="project-ooni-probe"></a>
    <h3><a href="https://ooni.torproject.org/">Ooni Probe</a> (<a
    href="https://gitweb.torproject.org/ooni-probe.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Ooni&order=priority">bug
    tracker</a>)</h3>

<p>
    Censorship scanner, checking your local connection for blocked or modified
    content.
    </p>

<p>
    <b>Project Ideas:</b><br />
    <i><a href="#ooniprobePcapsSupport">Add Support for Reporting Pcaps to OoniBackend and OoniProbe</a></i>
    </p>

<a id="project-torps"></a>
    <h3>TorPS</a> (<a href="https://github.com/torps/torps">code</a>)</h3>

<p>
    The Tor Path Simulator (TorPS) is a tool for efficiently simulating
    path selection in Tor. It chooses circuits and assigns user streams to
    those circuits in the same way that Tor does. TorPS is fast enough to
    perform thousands of simulations over periods of months.
    </p>

<a id="project-torflow"></a>
    <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorFlow">TorFlow</a> (<a
    href="https://gitweb.torproject.org/torflow.git">code</a>, <a
    href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torflow&order=priority">bug
    tracker</a>)</h3>

<p>
    Library and collection of services for actively monitoring the Tor network.
    These include the Bandwidth Scanners (measuring throughput of relays) and
    SoaT (scans for malicious or misconfigured exit nodes). SoaT was last
    actively developed in the Summer of 2010, and the Bandwidth Scanners a few
    months later. Both have been under active use since then, but development
    has stopped.
    </p>

<p>
    Tor2web allows Internet users to browse websites running in <a
    href="<page docs/hidden-services>">Tor hidden services</a>. It trades
    user anonymity for usability by allowing anonymous content to be
    distributed to non-anonymous users.
    </p>

<a id="project-anonbib"></a>
    <h3><a
    href="http://freehaven.net/anonbib/">Anonymity Bibliography</a> (<a
    href="https://gitweb.torproject.org/anonbib.git">code</a>)</h3>

<p>
    Anonbib is a list of important papers in the field of anonymity. It's
    also a set of scripts to generate the website from Latex (bibtex). If
    we're missing any important papers, please let us know!
    </p>

<a id="Coding"></a>
    <a id="Summer"></a>
    <h2><a class="anchor" href="#Coding">Project Ideas</a></h2>

<p>
    You may find some of these projects to be good ideas for <a href="<page
    about/gsoc>">Google Summer of Code</a> and the <a
    href="https://live.gnome.org/OutreachProgramForWomen">Outreach Program for
    Women</a>. We have labelled each idea with how much work we expect it would
    be (effort level), how much clue you should start with (skill level),
    and which of our <a href="<page about/corepeople>">core developers</a>
    would be good mentors. If one or more of these ideas looks promising to
    you, please <a href="<page about/contact>">contact us</a> to discuss your
    plans rather than sending blind applications. You may also want to propose
    your own project idea &mdash; which often results in the best applications.
    </p>

<ol>

<a id="torCleanup"></a>
    <li>
    <b>Tor Codebase Cleanup</b>
    <br>
    Effort Level: <i>Low to High, depending on subproject chosen</i>
    <br>
    Skill Level: <i>Medium to High</i>
    <br>
    Likely Mentors: <i>David (dgoulet)</i>
    <p>
    The Tor code is more than 10 years old in places, and we haven't always had
    enough time or wisdom to write things as well as we could have.  Our unit
    test coverage is shamefully low, and the dependency graph of our modules is
    shamefully convoluted . We could use refactoring and unit tests!  Please
    look through the Tor source code and look for ugly or tricky code or
    dependencies -- the uglier and trickier the better -- and think about how
    you could make the code look better, read better, and (subject to testing)
    work better.
    </p>

<p>
    If this is for a fun side-project, it would be great for you to work on
    anything that can be made better and more tested.  For an internship-level
    position, we'd hope that you could find a number of particularly tricky or
    knotty piece of the code to clean up, and aim for resolving the ugliest
    problems, not necessarily the easiest.
    </p>

<p>
    For a big project here, it would be great to pick one of the major
    "submodules" of Tor -- path selection, node discovery, directory authority
    operations, directory service -- and refactor its interface completely, to
    minify and codify its points of contact with the rest of Tor.
    </p>

<p>
    <b>As part of your application for this project please identify one of the
    thorniest Tor functions and submit a patch refactoring it to be better. If
    you find this to be difficult then this likely isn't the project for
    you.</b>
    </p>
    </li>

<a id="betterPluggableTransports"></a>
    <li>
    <b>Build Better Pluggable Transports</b>
    <br>
    Effort Level: <i>Medium to High</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>Ximin (infinity0)</i>
    <p>
    For Tor users in censored countries, we have a <a
    href="<page docs/pluggable-transports>">
    pluggable transports</a> framework that uses external programs to bypass
    censorship in different ways. Each of these have their own strengths and
    weaknesses.
    </p>

<p>
    We have deployed <a
    href="<page projects/obfsproxy>">obfsproxy</a>, 
    <a href="http://crypto.stanford.edu/flashproxy/">flashproxy</a>, 
    <a href="http://www.cs.kau.se/philwint/scramblesuit/">scramblesuit</a>, 
    <a href="https://trac.torproject.org/projects/tor/wiki/doc/meek">meek</a>,
    and <a href="https://fteproxy.org/about">FTE</a> bridges into the main 
    Tor Browser.</a>
    </p>

<p>
    There are several possible directions for this project. Ideas include:
      <ol>
        <li>Address gaps or weaknesses in our existing pluggable transports
          <ul>
            <li>Flashproxy: Add WebRTC support to traverse NATs.</li>
            <li>Flashproxy: Improve the facilitator's resistance against DoS
            and poisoning attacks.</li>
          </ul>
        </li>
        <li>Finish and release our pluggable transport combiner, that chains
        several transports together to take advantage of orthogonal types of
        blocking resistance.</li>
        <li>Improve the UX for selecting the appropriate pluggable transport in
        the new Tor Browser, whilst maintaining user security.</li>
        <li>Implement a new pluggable transport that resists blocking in a
        novel way.
        <ul>
          <li>Impersonate a voice-over-IP protocol</li>
          <li>Impersonate HTTP <a
          href="http://www.cs.utexas.edu/~amir/papers/parrot.pdf">sufficiently
          well</a> that traffic will go through a HTTP-only proxy</li>
          <li>Implement <a
          href="http://cacr.uwaterloo.ca/techreports/2011/cacr2011-21.pdf">scanning
          resistance</a></li>
        </ul>
        </li>
      </ol>
    </p>

<p>
    Applicants should be familiar with asynchronous/reactive programming, in
    particular the <a href="https://twistedmatrix.com/">Twisted framework</a>
    or something related. Most of the existing code is written in Python, with
    some parts in JavaScript and Go, so you should know at least one of these.
    You are invited to talk to us and ask questions, via our mailing lists
    or IRC. <b>As part of your application, please contribute a patch that
    implements a small feature or fixes a bug related to this area, e.g. <a
    href="https://trac.torproject.org/projects/tor/query?status=!closed&component=Pluggable+transport">1</a>,
    <a href="https://trac.torproject.org/projects/tor/query?status=!closed&component=Obfsproxy">2</a>,
    <a href="https://trac.torproject.org/projects/tor/query?status=!closed&component=Flashproxy">3</a>.
    </b>
    </p>

<a id="makeTorbirdyBetter"></a>
    <li>
    <b>Make TorBirdy Better</b>
    <br>
    Effort Level: <i>High</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>Sukhbir Singh (sukhe), Jacob Appelbaum (ioerror)</i>
    <p>
TorBirdy is an extension that configures Thunderbird to make connections over
the Tor anonymity network. TorBirdy has been under development for quite a
while but there are two known leaks that prevent it from being used by a wider
audience. As part of this project, you will be working on implementing a HTTP
proxy.
    </p>

<p>

<p>
<b>HTTP Proxy</b> TorBirdy needs a HTTP proxy or a HTTP -&gt; SOCKS5 shim. Please look at
ticket <a href="https://trac.torproject.org/projects/tor/ticket/6958">#6958</a>
for more information. Note: this has to be done using JavaScript and without using
an external proxy.
    </p>

<p>
If time permits and you are awesome enough to finish the above two tasks, you
will be working on the <a href="https://trac.torproject.org/projects/tor/query?status=!closed&component=TorBirdy">
remaining TorBirdy tickets</a>.
    </p>

<p>
Applicants should be familiar with JavaScript (and preferably C++ as well). As
part of your application for this project, please submit code samples for
previous JavaScript projects that you have developed, or point us to projects
you have been involved with (links to a public Git/GitHub repository
preferred).  Prior extension development is a big plus and will be given
preference during application ranking.
    </p>

<p>
You may contact the mentors on IRC for more information. (sukhe on #tor-dev, #tor on irc.oftc.net)
    </p>
    </li>

<a id="ooniprobePcapsSupport"></a>
    <li>
    <b>Add Support for Reporting Pcaps to OoniBackend and OoniProbe</b>
    <br>
    Effort Level: <i>Medium</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>Arturo (hellais)</i>
    <p>
The feature should also add support for including only packet capture data that
is relevant to the test being run. This means that the pcap should not contain
all the data sniffed on the users machine, but only that which was generated
and intended to be received by ooniprobe.
    </p>

<p>
This can probably be implemented by setting up a tun/tap device and routing all
the ooniprobe traffic through it and only capturing data sent and received from
that device. The task for the student will also be that of doing research into
what are possible strategies for doing this. <b><a
href="https://trac.torproject.org/projects/tor/ticket/7416">For more
information see ticket 7416.</a></b>
    </p>
    </li>

<a id="improveTorTestCoverage"></a>
    <li>
    <b>Improve test coverage in Tor</b>
    <br>
    Effort Level: <i>Medium</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>David (dgoulet)</i>
    <p>
Right now, our unit test coverage with the tests we ship is around 30%
-- only 30% of the executable lines in our source are reached by the
unit tests.  Improving this test coverage could make Tor development
much more reliable.
    </p>

<p>
So we need better unit tests, and we need better integration tests too.
    </p>

<p>
Improving unit tests would involve refactoring functions to be more
testable, and writing a bunch of unit tests.
    </p>

<p>
Improving integration tests would involve refactoring and improving
the "chutney" program that launches a test tor network, and writing a
bunch of tests to see what works and what doesn't work on such a
network.  It could also involve writing tests using the library "<a
href="https://stem.torproject.org/">stem</a>" to script individual clients on a
Chutney network.
    </p>

<p>
To get a feel for how testing works in Tor today, download Tor and
Chutney, and make sure you can build Tor and use Chutney.  See how the
unit tests work by skimming some of the test code in the src/test
subdirectory.  Try computing test coverage (according to the
instructions in the doc/HACKING file.
    </p>

<p>
Also, have a look at the one current integration test that works on
chutney today: it is a shell script distributed with Tor as
src/test/test-tor-network.sh .  We probably don't want to have all of
our integration tests be written as shell scripts, but it's interesting
to see how one works.
    </p>

<p>
If working on designs for an improved or refactored Chutney, watch out for <a
href="http://www.joelonsoftware.com/articles/fog0000000018.html">"archicture
astronautics"</a>: while it's important that we have a well-designed and
maintainable Chutney architecture, it wouldn't be very useful if a good
architecture were the <em>only</em> outcome here: we need tests too.
    </p>

<p>
As part of the application process, please contribute a patch that makes
a non-trivial improvement to chutney, and/or include a new test for some
interesting Tor function. (Please pick a function that isn't completely
easy to test.)
    </p>
    </li>

<a id="useMoreCores"></a>
    <li>
    <b>Have the Tor daemon use more cores</b>
    <br>
    Effort Level: <i>Medium</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>David (dgoulet)</i>
    <p>
Right now, if you run a busy Tor server on a multicore computer, most of
the cores are mostly unused.  We have a "cpuworker" mechanism to move
expensive computations into worker threads, but that mechanism is
currently only used for a small fraction of our cryptography.  Moving
more work into the worker threads could improve performance immensely.
    </p>

<p>
So it would be great to parallelize our cryptography more in order to
better handle more cores.  See
<a href="https://trac.torproject.org/projects/tor/wiki/org/projects/Tor/MultithreadedCrypto">MultithreadedCrypto</a>
for some background info, and
<a href="https://trac.torproject.org/projects/tor/ticket/7572">ticket 7572</a> for some subtickets
on our tracker.
    </p>

<p>
(If you're reading through the code to see how it works today, you will
also want to have a look at the new implementation for cpuworkers
described in <a href="https://trac.torproject.org/projects/tor/ticket/9682">9682</a>.)
    </p>

<p>
Completing the implementation of ticket #7572 --which would move our
circuit crypto onto separate threads-- could be a good summer project.
Alternatively, moving all of the signature generation and verification
code onto the cpuworkers could be fun.  In either case, you will have
some important architectural decisions to make about how to minimize
shared data between the main thread and the workers, how to avoid
race conditions between them, and how to test it all to make sure it has
no hidden failure cases.
    </p>

<p>
As part of the application process for this project, please contribute a
nontrivial patch to Tor -- ideally, one that will affect some part of
the codebase that you want to work on.
    </p>
    </li>

<a id="improveHiddenServices"></a>
    <li>
    <b>Help improve Tor hidden services</b>
    <br>
    Effort Level: <i>Medium</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>David (dgoulet), George (asn)</i>
    <p>
We're working on a revamp of the entire Tor hidden service design to
improve the security and reliability of the hidden service system.
    </p>

<p>
This is a big project: see
<a href="https://gitweb.torproject.org/torspec.git/tree/proposals/224-rend-spec-ng.txt">proposal
224</a> for the latest design.  Are you interested in implementing some
part of that?
    </p>

<p>
This is a very ambitious project, so we're deliberately not suggesting
particular sub-topics.  If you're interested in participating, try to
read and understand the <a
href="https://gitweb.torproject.org/torspec.git/tree/rend-spec.txt">existing
design</a> and the design proposal for the new design, and then talk to
us about what part you want to work on.
    </p>

<a id="improvedDnsSupport"></a>
    <li>
    <b>Improved DNS support for Tor</b>
    <br>
    Effort Level: <i>Medium</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>David (dgoulet)</i>
    <p>
Right now, you can only use Tor's DNS support to look up IPv4 and IPv6
addresses, and to fetch PTR records.  But DNS can do so much more!
    </p>

<p>
<a
href="https://gitweb.torproject.org/torspec.git/tree/proposals/219-expanded-dns.txt">Proposal
219</a> describes some new cell types that Tor could use to support
more types of DNS over Tor.
    </p>

<p>
To see how Tor implements its existing DNS lookups, start by tracing the
the connection_exit_begin_resolve() function in src/or/connection_edge.c ,
and see how we pass these requests downwards through src/or/dns.c to the
underlying resolver.  It's not too complicated, but there are some
tricky parts to understand.
    </p>

<a id="exitmap_improvements"></a>
    <li>
    <b>Exitmap Improvements</b>
    <br>
    Effort Level: <i>Medium</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>Philipp (phw)</i>
    <p>
The Tor Project makes use of the Python tool <a
href="https://gitweb.torproject.org/user/phw/exitmap.git/">Exitmap</a> to
systematically scan for malicious and misbehaving exit relays.  Once such a
relay is found, it is assigned the BadExit flag which prevents clients from
selecting the relay as last hop in their circuit.
    </p>

<p>
Exitmap supports scanning modules which implement a specific scan over
exit relays.  Examples are the DNS module which checks for DNS poisoning
or the patching check module which looks out for tampered file
downloads.
    </p>

<p>
This project is meant to extend exitmap in several ways.  First, it
should be made fully autonomous.  That means that exitmap should be able
to run in the background, periodically fetch new relay descriptors, and
have a smart algorithm which keeps scanning all exit relays
periodically.  Second, exitmap should be able to emulate some user
interaction and dynamically "explore" the web in order to detect
tampering.  Third, unit tests should be added for existing and new code
in order to make the code base more robust.
    </p>
    </li>

<a id="coniks_in_messenger"></a>
    <li>
    <b>Implement and Integrate CONIKS for Tor Messenger</b>
    <br>
    Effort Level: <i>Medium</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>Marcela, Arlo (arlolra)</i>
    <p>
CONIKS is an end-user key management and verification system for end-to-end
secure communication services, which improves upon existing key management
systems by providing both strong security and better usability using a model
called key transparency. CONIKS does this by requiring providers to manage
tamper-evident, publicly-auditable key directories, which contain mappings from
usernames to public keys, on behalf of their users. This design makes it easier
for users (both "default" users and power users) to establish trust since they
don't have to worry about or even see keys, but users also don't have to
trust the provider to be well-behaved because the CONIKS client can run as
part of the secure messaging app and automatically check that the service
provider doesn’t map spurious keys to their users' usernames, and it can
verify that observed name-to-key mappings are consistent with what other
clients in the system are seeing. Unlike existing key transparency solutions,
CONIKS also provides strong privacy guarantees by employing cryptographic
primitives for robust data obfuscation.
    </p>

<p>
The CONIKS system design, protocols, and proof-of-concept are described in
great detail in the <a
href="https://www.usenix.org/system/files/conference/usenixsecurity15/sec15-paper-melara.pdf">CONIKS
research paper</a>, and basic reference implementations of a CONIKS key server
and a CONIKS client are avialable on <a
href="https://github.com/coniks-sys/coniks-ref-implementation">Github</a>.
    </p>

<p>
This project has two main components: (1) designing and implementing a CONIKS
key server tailored to Tor Messenger users, and (2) building a CONIKS client
which integrates with the Tor Messenger client. One challenge the applicant
will face is ensuring that the key server design is efficient and scalable for
large volumes of users, concurrent traffic and guarantees this scalability even
as Tor Messenger's user base grows. On the client side, the main challenges
will be to focus on space efficiency as well as minimizing computational
overhead when implementing the CONIKS consistency checks, and determining how
to best communicate CONIKS consistency check results to users in the UI. Since
Tor Messenger does not hand out online identities per se, as most online
communication services do (like, say, Twitter, in which each user has a unique
handle), the CONIKS key server for Tor Messenger will have to map usernames
from third-party communication services to the encryption keys used in Tor
Messenger. One additional important challenge that the applicant will have to
help address is ensuring that each such third-party username remains unique in
the Tor Messenger space and that such external, third-party identities are
indeed controlled by the expected user of that third-party communication
service.
    </p>

<p>
Some design and implementation questions have been discussed in <a
href="https://trac.torproject.org/projects/tor/ticket/17961">Ticket #17961</a>.
    </p>

<p>
The applicant should have some familiarity with well-known crypto primitives
and algorithms, as well as have a basic understanding of the key transparency
model. Client side integration will require some basic use of JavaScript.
Consider submitting a patch for <a
href="https://github.com/arlolra/ctypes-otr/issues">one of the open key
verification issues</a> as part of the application process.
    </p>
    </li>
<!--
    <a id=""></a>
    <li>
    <b></b>
    <br>
    Effort Level: <i>Medium</i>
    <br>
    Skill Level: <i>Medium</i>
    <br>
    Likely Mentors: <i>Damian (atagar)</i>
    <p>

</p>

<p>

</p>
    </li>
-->

<li>
    <b>Bring up new ideas!</b>
    <br>
    Don't like any of these? Look at the <a
    href="/press/presskit/2008-12-19-roadmap-full.pdf">Tor development
    roadmap</a> for more ideas, or just try out Tor and Tor Browser,
    and find out what you think needs fixing.
    Some of the <a href="<spectree>proposals">current proposals</a>
    might also be short on developers.
    </li>

</ol>

<a id="OtherCoding"></a>
    <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>
    <ol>
    <li>Tor relays don't work well on Windows XP. On
    Windows, Tor uses the standard <tt>select()</tt> system
    call, which uses space in the non-page pool. This means
    that a medium sized Tor relay will empty the non-page pool, <a
    href="<wiki>doc/WindowsBufferProblems">causing
    havoc and system crashes</a>. We should probably be using overlapped IO
    instead. One solution would be to teach <a
    href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
    overlapped IO rather than select() on Windows, and then adapt Tor to
    the new libevent interface. Christian King made a
    <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good
    start</a> on this in the summer of 2007.</li>

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

<li>Tor 0.1.1.x and later include support for hardware crypto
    accelerators via OpenSSL. It has been lightly tested and is
    possibly very buggy.  We're looking for more rigorous testing,
    performance analysis, and optimally, code fixes to OpenSSL and
    Tor if needed.</li>

<li>Write a <a
    href="https://secure.wikimedia.org/wikipedia/en/wiki/Fuzz_testing">fuzzer</a>
    for Tor to discover security vulnerabilities. Determine if there
    are good fuzzing frameworks out there for what we want. Win fame by
    getting credit when we put out a new release because of you!</li>

<li>Tor uses TCP for transport and TLS for link
    encryption. This is nice and simple, but it means all cells
    on a link are delayed when a single packet gets dropped, and
    it means we can only reasonably support TCP streams. We have a <a
    href="<page docs/faq>#TransportIPnotTCP">list
    of reasons why we haven't shifted to UDP transport</a>, but it would
    be great to see that list get shorter. We also have a proposed <a
    href="<specblob>proposals/100-tor-spec-udp.txt">specification
    for Tor and
    UDP</a> &mdash; please let us know what's wrong with it.</li>

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

<li>We need a way to generate the website diagrams (for example, the "How
    Tor Works" pictures on the <a href="<page about/overview>">overview page</a>
    from source, so we can translate them as UTF-8 text rather than edit
    them by hand with Gimp. We might want to
    integrate this as an wml file so translations are easy and images are
    generated in multiple languages whenever we build the website.</li>

<li>How can we make the various LiveCD/USB systems easier
    to maintain, improve, and document?  One example is <a
    href="https://tails.boum.org/">The Amnesic Incognito Live
    System</a>.
    </li>

<li>
    Another anti-censorship project is to try to make Tor
    more scanning-resistant.  Right now, an adversary can identify <a
    href="<specblob>proposals/125-bridges.txt">Tor bridges</a>
    just by trying to connect to them, following the Tor protocol,
    and seeing if they respond.  To solve this, bridges could <a
    href="<svnprojects>design-paper/blocking.html#tth_sEc9.3">act like
    webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
    and not act like bridges until the user provides a bridge-specific key.
    To start, check out Shane Pope's <a
    href="http://dl.dropbox.com/u/37735/index.html">thesis and prototype</a>.
    </li>

</ol>

<a id="Research"></a>
    <h2><a class="anchor" href="#Research">Research</a></h2>
    <ol>
    <li>The "end-to-end traffic confirmation attack":
    by watching traffic at Alice and at Bob, we can <a
    href="http://freehaven.net/anonbib/#danezis:pet2004">compare
    traffic signatures and become convinced that we're watching the same
    stream</a>. So far Tor accepts this as a fact of life and assumes this
    attack is trivial in all cases. First of all, is that actually true? How
    much traffic of what sort of distribution is needed before the adversary
    is confident he has won? Are there scenarios (e.g. not transmitting much)
    that slow down the attack? Do some traffic padding or traffic shaping
    schemes work better than others?</li>
    <li>A related question is: Does running a relay/bridge provide additional
    protection against these timing attacks? Can an external adversary that can't
    see inside TLS links still recognize individual streams reliably?
    Does the amount of traffic carried degrade this ability any? What if the
    client-relay deliberately delayed upstream relayed traffic to create a queue
    that could be used to mimic timings of client downstream traffic to make it
    look like it was also relayed? This same queue could also be used for masking
    timings in client upstream traffic with the techniques from <a
    href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
    but without the need for additional traffic. Would such an interleaving of
    client upstream traffic obscure timings for external adversaries? Would the
    strategies need to be adjusted for asymmetric links? For example, on
    asymmetric links, is it actually possible to differentiate client traffic from
    natural bursts due to their asymmetric capacity? Or is it easier than
    symmetric links for some other reason?</li>
    <li>Repeat Murdoch and Danezis's <a
    href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
    Oakland 05</a> on the current Tor network. See if you can learn why it
    works well on some nodes and not well on others. (My theory is that the
    fast nodes with spare capacity resist the attack better.) If that's true,
    then experiment with the RelayBandwidthRate and RelayBandwidthBurst
    options to run a relay that is used as a client while relaying the
    attacker's traffic: as we crank down the RelayBandwidthRate, does the
    attack get harder? What's the right ratio of RelayBandwidthRate to
    actually capacity? Or is it a ratio at all? While we're at it, does a
    much larger set of candidate relays increase the false positive rate
    or other complexity for the attack? (The Tor network is now almost two
    orders of magnitude larger than it was when they wrote their paper.) Be
    sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
    Clog the Queue</a> too.</li>
    <li>The "routing zones attack": most of the literature thinks of
    the network path between Alice and her entry node (and between the
    exit node and Bob) as a single link on some graph. In practice,
    though, the path traverses many autonomous systems (ASes), and <a
    href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
    that the same AS appears on both the entry path and the exit path</a>.
    Unfortunately, to accurately predict whether a given Alice, entry,
    exit, Bob quad will be dangerous, we need to download an entire Internet
    routing zone and perform expensive operations on it. Are there practical
    approximations, such as avoiding IP addresses in the same /8 network?</li>
    <li>Other research questions regarding geographic diversity consider
    the tradeoff between choosing an efficient circuit and choosing a random
    circuit. Look at Stephen Rollyson's <a
    href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
    paper</a> on how to discard particularly slow choices without hurting
    anonymity "too much". This line of reasoning needs more work and more
    thinking, but it looks very promising.</li>
    <li>Tor doesn't work very well when relays have asymmetric bandwidth
    (e.g. cable or DSL). Because Tor has separate TCP connections between
    each hop, if the incoming bytes are arriving just fine and the outgoing
    bytes are all getting dropped on the floor, the TCP push-back mechanisms
    don't really transmit this information back to the incoming streams.
    Perhaps Tor should detect when it's dropping a lot of outgoing packets,
    and rate-limit incoming streams to regulate this itself? I can imagine
    a build-up and drop-off scheme where we pick a conservative rate-limit,
    slowly increase it until we get lost packets, back off, repeat. We
    need somebody who's good with networks to simulate this and help design
    solutions; and/or we need to understand the extent of the performance
    degradation, and use this as motivation to reconsider UDP transport.</li>
    <li>A related topic is congestion control. Is our
    current design sufficient once we have heavy use? Maybe
    we should experiment with variable-sized windows rather
    than fixed-size windows? That seemed to go well in an <a
    href="http://www.psc.edu/index.php/hpn-ssh/638">ssh
    throughput experiment</a>. We'll need to measure and tweak, and maybe
    overhaul if the results are good.</li>
    <li>Our censorship-resistance goals include preventing
    an attacker who's looking at Tor traffic on the wire from <a
    href="<svnprojects>design-paper/blocking.html#sec:network-fingerprint">distinguishing
    it from normal SSL traffic</a>. Obviously we can't achieve perfect
    steganography and still remain usable, but for a first step we'd like to
    block any attacks that can win by observing only a few packets. One of
    the remaining attacks we haven't examined much is that Tor cells are 512
    bytes, so the traffic on the wire may well be a multiple of 512 bytes.
    How much does the batching and overhead in TLS records blur this on the
    wire? Do different buffer flushing strategies in Tor affect this? Could
    a bit of padding help a lot, or is this an attack we must accept?</li>
    <li>Tor circuits are built one hop at a time, so in theory we have the
    ability to make some streams exit from the second hop, some from the
    third, and so on. This seems nice because it breaks up the set of exiting
    streams that a given relay can see. But if we want each stream to be safe,
    the "shortest" path should be at least 3 hops long by our current logic, so
    the rest will be even longer. We need to examine this performance / security
    tradeoff.</li>
    <li>It's not that hard to DoS Tor relays or directory authorities. Are client
    puzzles the right answer? What other practical approaches are there? Bonus
    if they're backward-compatible with the current Tor protocol.</li>
    <li>Programs like <a
    href="<page docs/torbutton/index>">Torbutton</a> aim to hide
    your browser's UserAgent string by replacing it with a uniform answer for
    every Tor user. That way the attacker can't splinter Tor's anonymity set
    by looking at that header. It tries to pick a string that is commonly used
    by non-Tor users too, so it doesn't stand out. Question one: how badly
    do we hurt ourselves by periodically updating the version of Firefox
    that Torbutton claims to be? If we update it too often, we splinter the
    anonymity sets ourselves. If we don't update it often enough, then all the
    Tor users stand out because they claim to be running a quite old version
    of Firefox. The answer here probably depends on the Firefox versions seen
    in the wild. Question two: periodically people ask us to cycle through N
    UserAgent strings rather than stick with one. Does this approach help,
    hurt, or not matter? Consider: cookies and recognizing Torbutton users
    by their rotating UserAgents; malicious websites who only attack certain
    browsers; and whether the answers to question one impact this answer.
    </li>
    <li>How many bridge relays do you need to know to maintain
    reachability? We should measure the churn in our bridges. If there is
    lots of churn, are there ways to keep bridge users more likely to stay
    connected?
    </li>
    </ol>

<p>
    <a href="<page about/contact>">Let us know</a> if you've made progress on any
    of these!
    </p>
  </div>
  
  <div id = "sidecol">
#include "side.wmi"
#include "info.wmi"
  </div>
  
</div>

#include <foot.wmi>

tor-webwml.git

Drop 'Txtorcon/Stem Integration'