tor-webwml.git

1) ## translation metadata

2) # Revision: $Revision$

3) # Translation-Priority: 4-optional
4) 
5) #include "head.wmi" TITLE="Tor: Volunteer" CHARSET="UTF-8"
6) <div id="content" class="clearfix">
7)   <div id="breadcrumbs">

8)     <a href="<page index>">Home &raquo; </a>

9)     <a href="<page getinvolved/volunteer>">Volunteer</a>
10)   </div>

11)   <div id="maincol">

12)     <!-- PUT CONTENT AFTER THIS TAG -->
13)     <h1>A few things everyone can do now:</h1>
14)     <ol>
15)     <li>Please consider <a href="<page docs/tor-doc-relay>">running
16)     a relay</a> to help the Tor network grow.</li>

17)     <li>Do you have an Amazon account? Are you willing to spend up to $3 a

18)     month? Then spin up your own Tor <a href="<page
19)     docs/bridges>">bridge</a> in less than 10 minutes with <a

20)     href="https://cloud.torproject.org/">tor cloud</a>!</li>

21)     <li>Tell your friends! Get them to run relays. Get them to run hidden
22)     services. Get them to tell their friends.</li>
23)     <li>If you like Tor's goals, please <a href="<page donate/donate>">take a moment
24)     to donate to support further Tor development</a>. We're also looking
25)     for more sponsors &mdash; if you know any companies, NGOs, agencies,
26)     or other organizations that want anonymity / privacy / communications
27)     security, let them know about us.</li>
28)     <li>We're looking for more <a href="<page about/torusers>">good examples of Tor
29)     users and Tor use cases</a>. If you use Tor for a scenario or purpose not
30)     yet described on that page, and you're comfortable sharing it with us,
31)     we'd love to hear from you.</li>
32)     </ol>

33) 

34)     <a id="Documentation"></a>
35)     <h2><a class="anchor" href="#Documentation">Documentation</a></h2>
36)     <ol>

37)     <li>Help translate the
38) <!-- web page and -->
39)     documentation into other

40)     languages. See the <a href="<page getinvolved/translation>">translation
41)     guidelines</a> if you want to help out. We especially need Arabic or
42)     Farsi translations, for the many Tor users in censored areas.</li>
43)     <li>Evaluate and document

44)     <a href="<wiki>doc/TorifyHOWTO">our

45)     list of programs</a> that can be configured to use Tor.</li>
46)     <li>We have a huge list of <a

47)     href="<wiki>doc/SupportPrograms">potentially useful

48)     programs that interface to Tor</a>. Which ones are useful in which
49)     situations? Please help us test them out and document your results.</li>
50)     </ol>

51) 

52)     <a id="Advocacy"></a>
53)     <h2><a class="anchor" href="#Advocacy">Advocacy</a></h2>
54)     <ol>

55)     <li>Create a presentation that can be used for various user group
56) meetings around the world.</li>

57)     <li>Create a video about the positive uses of Tor, what Tor is,
58)     or how to use it.  Some have already started on <a

59)     href="https://media.torproject.org/video/">Tor's Media server</a>,

60)     <a

61)     href="http://www.howcast.com/videos/90601-How-To-Circumvent-an-Internet-Proxy">Howcast</a>,

62)     and <a href="http://www.youtube.com/thetorproject">YouTube</a>.</li>

63)     <li>Create a poster, or a set of posters, around a theme,

64)     such as "Tor for Freedom!"</li>
65)     <li>Create a t-shirt design that incorporates "<a
66)     href="https://check.torproject.org/">Congratulations! You are using
67)     Tor!</a>" in any language.</li>

68)     </ol>

69) 

70) <!--

71)     <a id="gsoc"></a>
72)     <h2><a class="anchor" href="#gsoc">Google Summer of Code</a></h2>
73) 
74)     <p>
75)     Tor is also taking part in this year's <a
76)     href="https://www.google-melange.com/gsoc/homepage/google/gsoc2013">Google
77)     Summer of Code</a>! The criteria for this is a little different - either
78)     gender can apply but you need to be either <a
79)     href="https://www.google-melange.com/gsoc/document/show/gsoc_program/google/gsoc2013/help_page#2._Whos_eligible_to_participate_as_a">a
80)     present student or just graduated</a>.
81)     </p>
82) 
83)     <p>
84)     As mentioned above if you're eligible for either program then please apply
85)     for both! Google Summer of Code is a far, far larger program for us than
86)     OPW so your chances of being applied that way are considerably better.
87)     </p>
88) 
89)     <p>
90)     <b>See our page for <a href="<page about/gsoc>">Google Summer of Code</a>
91)     for more information.</b>
92)     </p>

93) -->

94) 

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

97) 

98)     <p>
99)     Below are a list of Tor related projects we're developing and/or
100)     maintaining. Most discussions happen on IRC so if you're interested in any
101)     of these (or you have a project idea of your own), then please <a

102)     href="<page about/contact>#irc">join us in #tor-dev</a>. Don't be shy
103)     to ask questions, and don't hesitate to ask even if the main contributors
104)     aren't active at that moment.

105)     </p>

106) 

107)     <p>
108)     For a presentation summarizing many of these projects see...
109)     </p>
110) 
111)     <div id="ecosystem_presentation">
112)       <a href="https://media.torproject.org/video/2013-11-t3am-damian-johnson.mp4">Tor Ecosystem</a> (<a href="https://svn.torproject.org/svn/projects/presentations/2013-11-t3am-tor-ecosystem.pdf">slides</a>)
113)     </div>
114) 
115)     <br /></br />
116) 

117)     <table id="projects">
118)       <tr>
119)         <th>Name</th>
120)         <th>Category</th>
121)         <th>Language</th>
122)         <th>Activity</th>
123)         <th>Contributors</th>
124)       </tr>

125) 

126)       <tr>
127)         <td><a href="#project-tor">Tor</a></td>
128)         <td>Core</td>
129)         <td>C</td>
130)         <td>Heavy</td>

131)         <td>nickm, athena, arma</td>

132)       </tr>

133) 

134)       <tr>

135)         <td>*<a href="#project-orchid">Orchid</a></td>

136)         <td>Core</td>
137)         <td>Java</td>

138)         <td>Moderate</td>

139)         <td>bleidl</td>
140)       </tr>
141) 
142)       <tr>

143)         <td><a href="#project-torbrowser">Tor Browser</a></td>

144)         <td>Bundle</td>

145)         <td>C, Scripting</td>

146)         <td>Moderate</td>

147)         <td>mikeperry, Erinn</td>

148)       </tr>

149) 

150)       <tr>

151)         <td><a href="#project-torbutton">Torbutton</a></td>
152)         <td>Browser Add-on</td>
153)         <td>Javascript</td>
154)         <td>Moderate</td>
155)         <td>mikeperry</td>

156)       </tr>

157) 

158)       <tr>

159)         <td><a href="#project-httpseverywhere">HTTPS Everywhere</a></td>
160)         <td>Browser Add-on</td>
161)         <td>Javascript</td>

162)         <td>Heavy</td>

163)         <td>pde, mikeperry</td>

164)       </tr>

165) 

166)       <tr>

167)         <td><a href="#project-vidalia">Vidalia</a></td>
168)         <td>User Interface</td>
169)         <td>C++, Qt</td>

170)         <td>None</td>

171)         <td>chiiph</td>
172)       </tr>

173) 

174)       <tr>

175)         <td><a href="#project-arm">Arm</a></td>
176)         <td>User Interface</td>
177)         <td>Python, Curses</td>

178)         <td>Light</td>

179)         <td>atagar</td>
180)       </tr>

181) 

182)       <tr>

183)         <td><a href="#project-orbot">Orbot</a></td>
184)         <td>User Interface</td>
185)         <td>Java</td>

186)         <td>Light</td>

187)         <td>n8fr8</td>

188)       </tr>

189) 

190)       <tr>

191)         <td><a href="#project-tails">Tails</a></td>
192)         <td>OS image</td>
193)         <td>Sys Admin</td>
194)         <td>Heavy</td>
195)         <td><a href="https://tails.boum.org/">#tails</a></td>

196)       </tr>

197) 

198)       <tr>

199)         <td><a href="#project-torramdisk">tor-ramdisk</a></td>
200)         <td>OS image</td>
201)         <td>Sys Admin</td>

202)         <td>None</td>

203)         <td>blueness</td>
204)       </tr>
205) 

206)       <tr>

207)         <td>*<a href="#project-torouter">Torouter</a></td>
208)         <td>OS image</td>
209)         <td>Sys Admin</td>

210)         <td>None</td>

211)         <td>ioerror</td>
212)       </tr>
213) 

214)       <tr>

215)         <td><a href="#project-torsocks">Torsocks</a></td>
216)         <td>Usability</td>
217)         <td>C</td>

218)         <td>Light</td>

219)         <td>ioerror, nickm</td>
220)       </tr>
221) 

222)       <tr>

223)         <td><a href="#project-torbirdy">TorBirdy</a></td>
224)         <td>Browser Add-on</td>
225)         <td>JavaScript</td>
226)         <td>Heavy</td>

227)         <td>Sukhbir (sukhe)</td>

228)       </tr>

229) 

230)       <tr>

231)         <td><a href="#project-obfsproxy">Obfsproxy</a></td>
232)         <td>Client Add-on</td>

233)         <td>Python</td>

234)         <td>Moderate</td>

235)         <td>asn</td>

236)       </tr>
237) 

238)       <tr>

239)         <td><a href="#project-flash-proxy">Flash Proxy</a></td>
240)         <td>Client Add-on</td>
241)         <td>Python, JavaScript, Go</td>

242)         <td>Heavy</td>

243)         <td>dcf, aallai, jct</td>
244)       </tr>

245) 

246)       <tr>

247)         <td><a href="#project-shadow">Shadow</a></td>

248)         <td>Simulator</td>

249)         <td>C, Python</td>

250)         <td>Heavy</td>

251)         <td>robgjansen</td>
252)       </tr>

253) 

254)       <tr>

255)         <td><a href="#project-stem">Stem</a></td>

256)         <td>Library</td>
257)         <td>Python</td>
258)         <td>Heavy</td>

259)         <td>atagar</td>

260)       </tr>

261) 

262)       <tr>

263)         <td><a href="#project-txtorcon">Txtorcon</a></td>
264)         <td>Library</td>
265)         <td>Python, Twisted</td>

266)         <td>Moderate</td>

267)         <td>meejah</td>
268)       </tr>

269) 

270)       <tr>

271)         <td><a href="#project-tlsdate">Tlsdate</a></td>
272)         <td>Utility</td>
273)         <td>C</td>

274)         <td>Moderate</td>

275)         <td>ioerror</td>
276)       </tr>

277) 

278)       <tr>

279)         <td><a href="#project-metrics">Metrics</a></td>
280)         <td>Client Service</td>
281)         <td>Java</td>

282)         <td>Moderate</td>

283)         <td>karsten</td>
284)       </tr>

285) 

286)       <tr>

287)         <td><a href="#project-atlas">Atlas</a></td>
288)         <td>Client Service</td>
289)         <td>JavaScript</td>

290)         <td>Light</td>

291)         <td>hellais, karsten</td>

292)       </tr>

293) 

294)       <tr>
295)         <td><a href="#project-globe">Globe</a></td>
296)         <td>Client Service</td>
297)         <td>JavaScript</td>
298)         <td>Heavy</td>
299)         <td>Christian</td>
300)       </tr>
301) 

302)       <tr>

303)         <td><a href="#project-compass">Compass</a></td>
304)         <td>Client Service</td>
305)         <td>Python</td>

306)         <td>Light</td>

307)         <td>gsathya, karsten, cwacek</td>

308)       </tr>

309) 

310)       <tr>

311)         <td><a href="#project-onionoo">Onionoo</a></td>
312)         <td>Backend Service</td>
313)         <td>Java, Python</td>

314)         <td>Moderate</td>

315)         <td>karsten, gsathya</td>
316)       </tr>
317) 

318)       <tr>
319)         <td><a href="#project-doctor">DocTor</a></td>
320)         <td>Backend Service</td>
321)         <td>Python</td>
322)         <td>Light</td>
323)         <td>atagar</td>
324)       </tr>
325) 

326)       <tr>

327)         <td><a href="#project-weather">Weather</a></td>
328)         <td>Client Service</td>
329)         <td>Python</td>

330)         <td>None</td>

331)         <td>kaner</td>
332)       </tr>

333) 

334)       <tr>

335)         <td><a href="#project-gettor">GetTor</a></td>
336)         <td>Client Service</td>
337)         <td>Python</td>

338)         <td>None</td>

339)         <td>kaner</td>

340)       </tr>

341) 

342)       <tr>

343)         <td><a href="#project-torcheck">TorCheck</a></td>
344)         <td>Client Service</td>

345)         <td>Go</td>
346)         <td>Moderate</td>
347)         <td>Arlo</td>

348)       </tr>

349) 

350)       <tr>

351)         <td><a href="#project-bridgedb">BridgeDB</a></td>
352)         <td>Backend Service</td>
353)         <td>Python</td>

354)         <td>Light</td>

355)         <td>kaner, nickm</td>

356)       </tr>

357) 

358)       <tr>

359)         <td><a href="#project-ooni-probe">Ooni Probe</a></td>

360)         <td>Scanner</td>
361)         <td>Python</td>

362)         <td>Moderate</td>

363)         <td>hellais, isis, ioerror</td>
364)       </tr>
365) 

366)       <tr>
367)         <td><a href="#project-torps">TorPS</a></td>
368)         <td>Backend Service</td>
369)         <td>Python</td>
370)         <td>Light</td>
371)         <td>Aaron Johnson</td>
372)       </tr>
373) 

374)       <tr>

375)         <td><a href="#project-torflow">TorFlow</a></td>
376)         <td>Backend Service</td>
377)         <td>Python</td>

378)         <td>None</td>

379)         <td>aagbsn, mikeperry</td>

380)       </tr>

381) 

382)       <tr>

383)         <td>*<a href="#project-torbel">TorBEL</a></td>
384)         <td>Backend Service</td>
385)         <td>Python</td>
386)         <td>None</td>
387)         <td>Sebastian</td>
388)       </tr>

389) 

390)       <tr>

391)         <td><a href="#project-tor2web">Tor2web</a></td>
392)         <td>Client Service</td>

393)         <td>Python</td>

394)         <td>Moderate</td>

395)         <td>evilaliv3, hellais</td>

396)       </tr>

397) 

398)       <tr>

399)         <td><a href="#project-anonbib">Anonbib</a></td>
400)         <td>Website</td>

401)         <td>Python</td>

402)         <td>Light</td>
403)         <td>arma, nickm</td>
404)       </tr>
405) 

406)     </table>

407) 

408)     <sub>
409)     * Project is still in an alpha state.
410)     </sub>

411) 

412)     <br /><br />

413) 

414)     <a id="project-tor"></a>
415)     <h3>Tor (<a href="https://gitweb.torproject.org/tor.git">code</a>, <a

416)     href="https://trac.torproject.org/projects/tor/report/12">bug

417)     tracker</a>)</h3>

418) 

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

424) 

425)     <p>
426)     <b>Project Ideas:</b><br />

427)     <i><a href="#torCleanup">Tor Codebase Cleanup</a></i><br />

428)     <i><a href="#httpsImpersonation">HTTPS Server Impersonation</a></i><br />

429)     <i><a href="#chutneyExpansion">Make Chutney Do More, More Reliably</a></i>

430)     </p>

431) 

432)     <a id="project-orchid"></a>
433)     <h3><a href="https://github.com/subgraph/Orchid">Orchid</a> (<a
434)     href="https://github.com/subgraph/Orchid">code</a>, <a
435)     href="https://github.com/subgraph/Orchid/issues">bug

436)     tracker</a>)</h3>

437) 

438)     <p>

439)     Java implementation of Tor and successor to <a href="http://onioncoffee.sourceforge.net/">OnionCoffee</a>.

440)     </p>

441) 

442)     <a id="project-torbrowser"></a>

443)     <h3><a href="<page projects/torbrowser>">Tor Browser Bundle</a> (<a
444)     href="https://gitweb.torproject.org/torbrowser.git">code</a>, <a
445)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+bundles/installation&order=priority">bug

446)     tracker</a>, <a href="https://www.torproject.org/projects/torbrowser/design/">design doc</a>)</h3>
447) 

448)     <p>
449)     The Tor Browser Bundle is an easy-to-use portable package of Tor, Vidalia,

450)     Torbutton, and a Firefox fork preconfigured to work together out of

451)     the box. It contains a modified copy of Firefox that aims to resolve the
452)     privacy and security issues in mainline version.

453)     </p>

454) 
455)     <a id="project-torbutton"></a>
456)     <h3><a href="<page torbutton/index>">Torbutton</a> (<a
457)     href="https://gitweb.torproject.org/torbutton.git">code</a>, <a
458)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torbutton&order=priority">bug

459)     tracker</a>)</h3>

460) 

461)     <p>

462)     Firefox addon that addresses many of the client-side threats to browsing
463)     the Internet anonymously. Mike has since continued to adapt it to new
464)     threats, updated versions of Firefox, and possibly <a
465)     href="https://blog.torproject.org/blog/google-chrome-incognito-mode-tor-and-fingerprinting">Chrome
466)     as well</a>.

467)     </p>

468) 
469)     <a id="project-httpseverywhere"></a>
470)     <h3><a href="https://www.eff.org/https-everywhere">HTTPS Everywhere</a> (<a
471)     href="https://gitweb.torproject.org/https-everywhere.git">code</a>, <a
472)     href="https://trac.torproject.org/projects/tor/report/19">bug

473)     tracker</a>)</h3>

474) 

475)     <p>

476)     HTTPS Everywhere is a Firefox and Chrome extension that encrypts
477)     your communications with many major websites, making your browsing
478)     more secure.

479)     </p>

480) 

481)     <a id="project-vidalia"></a>
482)     <h3><a href="<page projects/vidalia>">Vidalia</a> (<a

483)     href="https://gitweb.torproject.org/vidalia.git">code</a>, <a

484)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Vidalia&order=priority">bug
485)     tracker</a>)</h3>

486) 

487)     <p>
488)     The most commonly used user interface for Tor. Matt Edman started the
489)     project in 2006 and brought it to its current stable state. Development

490)     slowed for several years, though Tomás Touceda has since taken the
491)     lead with pushing the project forward.

492)     </p>

493) 

494)     <a id="project-arm"></a>

495)     <h3><a href="https://www.atagar.com/arm/">Arm</a> (<a

496)     href="https://gitweb.torproject.org/arm.git">code</a>, <a

497)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=arm&order=priority">bug
498)     tracker</a>)</h3>

499) 

500)     <p>

501)     The anonymizing relay monitor (arm) is a terminal status monitor for Tor,
502)     intended for command-line aficionados, ssh connections, and anyone with a
503)     tty terminal. This works much like top does for system usage, providing
504)     real time statistics for bandwidth, resource usage, connections, and quite
505)     a bit more.

506)     </p>

507) 

508)     <a id="project-orbot"></a>
509)     <h3><a href="https://guardianproject.info/apps/orbot/">Orbot</a> (<a

510)     href="https://gitweb.torproject.org/orbot.git">code</a>, <a

511)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Orbot&order=priority">bug
512)     tracker</a>)</h3>

513) 
514)     <p>
515)     Provides Tor on the Android platform. This was under very active
516)     development up through Fall 2010, after which things have been quiet.
517)     </p>
518) 
519)     <a id="project-tails"></a>
520)     <h3><a href="https://tails.boum.org/">The Amnesic Incognito Live System</a> (<a

521)     href="https://git-tails.immerda.ch/tails/">code</a>, <a
522)     href="https://labs.riseup.net/code/projects/tails">bug

523)     tracker</a>)</h3>
524) 
525)     <p>
526)     The Amnesic Incognito Live System is a live CD/USB distribution
527)     preconfigured so that everything is safely routed through Tor and leaves no
528)     trace on the local system. This is a merger of the Amnesia and <a
529)     href="http://www.anonymityanywhere.com/incognito/">Incognito</a> projects,
530)     and still under very active development.
531)     </p>
532) 

533)     <a id="project-torramdisk"></a>
534)     <h3><a href="http://opensource.dyc.edu/tor-ramdisk">Tor-ramdisk</a> (<a

535)     href="https://gitweb.torproject.org/tor-ramdisk.git">code</a>, <a

536)     href="http://opensource.dyc.edu/tor-ramdisk-documentation">documentation</a>)</h3>

537) 
538)     <p>

539)     Tor-ramdisk is a uClibc-based micro Linux distribution whose sole
540)     purpose is to securely host a Tor server purely in RAM.

541)     </p>
542) 

543)     <a id="project-torouter"></a>
544)     <h3><a
545)     href="<wiki>doc/Torouter">Torouter</a> (<a

546)     href="https://gitweb.torproject.org/torouter.git">code</a>, <a

547)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torouter&order=priority">bug
548)     tracker</a>)</h3>
549) 
550)     <p>
551)     Project to provide an easy-to-use, embedded Tor instance for routers. This
552)     had high activity in late 2010, but has since been rather quiet.
553)     </p>
554) 
555)     <a id="project-torsocks"></a>

556)     <h3>Torsocks (<a

557)     href="https://gitweb.torproject.org/torsocks.git">code</a>, <a
558)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torify&order=priority">bug
559)     tracker</a>)</h3>
560) 

561)     <p>

562)     Utility for adapting other applications to work with Tor. Development has
563)     slowed and compatibility issues remain with some platforms, but it's
564)     otherwise feature complete.

565)     </p>

566) 

567)     <a id="project-torbirdy"></a>
568)     <h3>TorBirdy (<a
569)     href="https://github.com/ioerror/torbirdy">code</a>, <a
570)     href="https://trac.torproject.org/projects/tor/wiki/torbirdy/dev">bug
571)     tracker</a>)</h3>

572) 

573)     <p>
574)     TorBirdy is Torbutton for Thunderbird and related Mozilla mail clients.
575)     </p>

576) 

577)     <a id="project-obfsproxy"></a>

578)     <h3><a href="<page projects/obfsproxy>">Obfsproxy</a> (<a

579)     href="https://gitweb.torproject.org/pluggable-transports/obfsproxy.git">code</a>,
580)     <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

581)     tracker</a>)</h3>

582) 

583)     <p>
584)     A proxy that shapes Tor traffic, making it harder for censors to detect and

585)     block Tor. This has both a C and python implementation.

586)     </p>

587) 

588)     <p>
589)     <b>Project Ideas:</b><br />
590)     <i><a href="#betterPluggableTransports">Build Better Pluggable Transports</a></i>
591)     </p>
592) 

593)     <a id="project-flash-proxy"></a>
594)     <h3><a href="https://crypto.stanford.edu/flashproxy/">Flash Proxy</a> (<a
595)     href="https://gitweb.torproject.org/flashproxy.git">code</a>, <a
596)     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
597)     tracker</a>)</h3>

598) 

599)     <p>
600)     Pluggable transport using proxies running in web browsers to defeat
601)     address-based blocking.
602)     </p>

603) 

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

609) 

610)     <p>
611)     Shadow is a discrete-event network simulator that runs the real
612)     Tor software as a plug-in. Shadow is open-source software that enables
613)     accurate, efficient, controlled, and repeatable Tor experimentation.

614)     For another simulator, see <a
615)     href="http://crysp.uwaterloo.ca/software/exptor/">ExperimenTor</a>.

616)     </p>

617) 

618)     <a id="project-stem"></a>

619)     <h3><a href="https://stem.torproject.org/">Stem</a> (<a

620)     href="https://gitweb.torproject.org/stem.git">code</a>, <a

621)     href="https://trac.torproject.org/projects/tor/wiki/doc/stem/bugs">bug

622)     tracker</a>)</h3>

623) 

624)     <p>

625)     Python controller library for scripts and controller applications using
626)     Tor.

627)     </p>

628) 

629)     <p>
630)     <b>Project Ideas:</b><br />

631)     <i><a href="#txtorcon-stemIntegration">Txtorcon/Stem Integration</a></i><br />

632)     </p>

633) 

634)     <a id="project-txtorcon"></a>

635)     <h3><a href="https://txtorcon.readthedocs.org">Txtorcon</a> (<a

636)     href="https://github.com/meejah/txtorcon">code</a>, <a

637)     href="https://github.com/meejah/txtorcon/issues">bug tracker</a>)</h3>

638) 

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

644) 

645)     <p>
646)     <b>Project Ideas:</b><br />
647)     <i><a href="#txtorcon-stemIntegration">Txtorcon/Stem Integration</a></i>
648)     </p>
649) 

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

652) 

653)     <p>
654)     tlsdate: secure parasitic rdate replacement
655)     </p>

656) 

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

664) 

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

669)     href="https://gitweb.torproject.org/metrics-web.git">web</a>)</h3>

670) 

671)     <p>
672)     Processing and analytics of consensus data, provided to users via the
673)     metrics portal. This has been under active development for several years by

674)     Karsten Loesing. See also <a
675)     href="https://gitweb.torproject.org/torperf.git">TorPerf</a>.

676)     </p>

677) 

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

681) 

682)     <p>
683)     Atlas is a web application to discover Tor relays and bridges. It provides
684)     useful information on how relays are configured along with graphics about

685)     their past usage.

686)     </p>

687) 

688)     <p>

689)     This is the spiritual successor to <a
690)     href="https://gitweb.torproject.org/torstatus.git">TorStatus</a>, the <a

691)     href="https://svn.torproject.org/svn/torstatus/trunk/">original

692)     codebase</a> for which was written in PHP, and rewritten by students from
693)     Wesleyan as Django.

694)     </p>

695) 

696)     <a id="project-globe"></a>
697)     <h3><a href="http://globe.rndm.de/">Globe</a> (<a
698)     href="https://github.com/makepanic/globe">code</a>, <a
699)     href="https://github.com/makepanic/globe/issues">bug tracker</a>)</h3>
700) 
701)     <p>
702)     Globe is a web application that allows you to search for Tor relays and
703)     bridges. It gives you a detailed overview of properties and configurations
704)     of a relay or bridge.
705)     </p>
706) 

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

712) 

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

717) 
718)     <a id="project-onionoo"></a>
719)     <h3><a href="<page projects/onionoo>">Onionoo</a> (<a
720)     href="https://gitweb.torproject.org/onionoo.git">java codebase</a>, <a
721)     href="https://gitweb.torproject.org/pyonionoo.git">python

722)     codebase</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>

723) 
724)     <p>
725)     Onionoo is a JSON based protocol to learn information about currently
726)     running Tor relays and bridges.
727)     </p>
728) 

729)     <a id="project-doctor"></a>
730)     <h3>DocTor (<a
731)     href="https://gitweb.torproject.org/doctor.git">code</a>, <a
732)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=DocTor&order=priority">bug
733)     tracker</a>)</h3>
734) 
735)     <p>
736)     DocTor is a notification service that monitors newly published descriptor
737)     information for issues. This is primarily a service to help the tor
738)     directory authority operators, but it also checks for a handful of other
739)     issues like sybil attacks.
740)     </p>
741) 

742)     <a id="project-weather"></a>

743)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/Weather">Weather</a> (<a

744)     href="https://gitweb.torproject.org/weather.git">code</a>, <a
745)     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
746)     tracker</a>)</h3>

747) 

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

754) 

755)     <a id="project-gettor"></a>

756)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/GetTor">GetTor</a> (<a

757)     href="https://gitweb.torproject.org/gettor.git">code</a>, <a

758)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=GetTor&order=priority">bug
759)     tracker</a>)</h3>

760) 

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

765) 

766)     <a id="project-torcheck"></a>

767)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorCheck">TorCheck</a> (<a

768)     href="https://gitweb.torproject.org/check.git">code</a>, <a

769)     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
770)     tracker</a>)</h3>

771) 

772)     <p>

773)     Site for determining if the visitor is using Tor or not.

774)     </p>

775) 

776)     <a id="project-bridgedb"></a>

777)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/BridgeDB">BridgeDB</a> (<a

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

781) 

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

786) 
787)     <a id="project-ooni-probe"></a>

788)     <h3><a href="https://ooni.torproject.org/">Ooni Probe</a> (<a

789)     href="https://gitweb.torproject.org/ooni-probe.git">code</a>, <a
790)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Ooni&order=priority">bug
791)     tracker</a>)</h3>
792) 
793)     <p>
794)     Censorship scanner, checking your local connection for blocked or modified
795)     content.
796)     </p>
797) 

798)     <p>
799)     <b>Project Ideas:</b><br />

800)     <i><a href="#censorshipAnalyzer">Develop a Censorship Analyzer</a></i>

801)     </p>
802) 

803)     <a id="project-torps"></a>
804)     <h3>TorPS</a> (<a href="https://github.com/torps/torps">code</a>)</h3>
805) 
806)     <p>
807)     The Tor Path Simulator (TorPS) is a tool for efficiently simulating
808)     path selection in Tor. It chooses circuits and assigns user streams to
809)     those circuits in the same way that Tor does. TorPS is fast enough to
810)     perform thousands of simulations over periods of months.
811)     </p>
812) 

813)     <a id="project-torflow"></a>

814)     <h3><a href="https://trac.torproject.org/projects/tor/wiki/org/roadmaps/TorFlow">TorFlow</a> (<a

815)     href="https://gitweb.torproject.org/torflow.git">code</a>, <a
816)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torflow&order=priority">bug
817)     tracker</a>)</h3>

818) 

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

827) 

828)     <a id="project-torbel"></a>
829)     <h3><a

830)     href="https://blog.torproject.org/blog/torbel-tor-bulk-exit-list-tools">TorBEL</a> (<a
831)     href="https://gitweb.torproject.org/torbel.git">code</a>, <a

832)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=TorDNSEL/TorBEL&order=priority">bug
833)     tracker</a>)</h3>

834) 

835)     <p>
836)     The Tor Bulk Exitlist provides a method of identifying if IPs belong to
837)     exit nodes or not. This is a replacement for TorDNSEL which is a stable
838)     (though unmaintained) Haskell application for this purpose. The initial
839)     version of TorBEL was started in GSOC 2010 but since then the project has
840)     been inactive.
841)     </p>

842) 
843)     <a id="project-tor2web"></a>
844)     <h3><a
845)     href="http://wiki.tor2web.org/index.php/Main_Page">Tor2web</a> (<a
846)     href="https://github.com/globaleaks/tor2web-3.0/wiki">code</a>)</h3>
847) 
848)     <p>
849)     Tor2web allows Internet users to browse websites running in <a
850)     href="<page docs/hidden-services>">Tor hidden services</a>. It trades
851)     user anonymity for usability by allowing anonymous content to be
852)     distributed to non-anonymous users.
853)     </p>
854) 

855)     <a id="project-anonbib"></a>
856)     <h3><a
857)     href="http://freehaven.net/anonbib/">Anonymity Bibliography</a> (<a
858)     href="https://gitweb.torproject.org/anonbib.git">code</a>)</h3>
859) 
860)     <p>

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

864)     </p>
865) 

866)     <a id="Coding"></a>
867)     <a id="Summer"></a>

868)     <h2><a class="anchor" href="#Coding">Project Ideas</a></h2>

869) 

870)     <p>

871)     You may find some of these projects to be good ideas for <a href="<page
872)     about/gsoc>">Google Summer of Code</a> and the <a
873)     href="https://live.gnome.org/OutreachProgramForWomen">Outreach Program for

874)     Women</a>. We have labelled each idea with how much work we expect it would
875)     be (effort level), how much clue you should start with (skill level),
876)     and which of our <a href="<page about/corepeople>">core developers</a>
877)     would be good mentors. If one or more of these ideas looks promising to
878)     you, please <a href="<page about/contact>">contact us</a> to discuss your
879)     plans rather than sending blind applications. You may also want to propose
880)     your own project idea &mdash; which often results in the best applications.

881)     </p>

882) 

883)     <ol>

884) 

885)     <a id="txtorcon-stemIntegration"></a>
886)     <li>
887)     <b>Txtorcon/Stem Integration</b>
888)     <br>
889)     Effort Level: <i>Medium</i>
890)     <br>
891)     Skill Level: <i>Medium</i>
892)     <br>
893)     Likely Mentors: <i>meejah, Damian (atagar)</i>
894)     <p>Txtorcon is a Twisted-based Python controller library, and Stem is a
895)     synchronous (threaded) one, also in Python. There is no need to have
896)     two implementations of (at least) the protocol parsing code. This
897)     project would entail eliminating duplication by leveraging Stem's
898)     parsing in txtorcon while keeping txtorcon's API the same (or at least
899)     close).</p>

900)     <p>Besides this you should identify some additional tasks to improve our
901)     controller space across these two libraries. Some ideas are...</p>
902)     <ul>
903)       <li>Write a tutorial for <a
904)       href="https://stem.torproject.org/tutorials.html">stem's tutorial
905)       page</a> demonstrating cross txtorcon/stem usage.</li>
906)       <li>Expand the txtorcon API to include functionality of <a
907)       href="https://gitweb.torproject.org/stem.git/blob/HEAD:/stem/control.py">stem's
908)       controller</a> that would be of interest to twisted users. All additions
909)       should include tests!</li>
910)       <li>Come up with some ideas of your own! We'd love to discuss them with
911)       you.</li>
912)     </ul>

913)     <p>This would very likely involve changes to both libraries, although
914)     most would be expected to be in txtorcon. meejah is available to
915)     mentor txtorcon changes, and Damian (atagar) can help with Stem.</p>
916)     <p>It would help if you're already familiar with event-based programming,
917)     bonus points if it's Twisted.</p>
918)     </li>
919) 

920)     <a id="httpsImpersonation"></a>

921)     <li>
922)     <b>HTTPS Server Impersonation</b>
923)     <br>
924)     Effort Level: <i>Medium to High</i>
925)     <br>
926)     Skill Level: <i>Medium to High</i>
927)     <br>
928)     Likely Mentors: <i>Nick (nickm)</i>

929)     <p>

930)     We have an open proposal for a way to make Tor bridges avoid censorship by
931)     impersonating an HTTPS server.  Specifically, we need to hack some popular
932)     SSL "reverse proxy" (your choice) so that it relays regular web connections
933)     to an HTTP server, but certain connections to a local Tor process.  <a
934)     href="https://gitweb.torproject.org/torspec.git/blob_plain/HEAD:/proposals/203-https-frontend.txt">Proposal
935)     203</a> has a general design sketch.

936)     </p>

937) 
938)     <p>
939)     <b>This project is likely trickier than it looks. You should avoid applying
940)     for this if you're uncertain about being able to complete it.</b>
941)     </p>
942)     </li>

943)     </li>

944) 

945)     <a id="chutneyExpansion"></a>
946)     <li>
947)     <b>Make Chutney Do More, More Reliably</b>
948)     <br>
949)     Effort Level: <i>Medium to High, depending on scope of project</i>
950)     <br>
951)     Skill Level: <i>Medium</i>
952)     <br>

953)     Likely Mentors: <i>Nick (nickm)</i>
954)     <p>

955)     We have a little Python tool called <a
956)     href="https://gitweb.torproject.org/nickm/chutney.git">Chutney</a> for
957)     making small local test networks.  It's small, not widely used, and not as
958)     automated as it could be.

959)     </p>

960) 

961)     <p>

962)     It would be great to see chutney extended and a set of supporting tests
963)     built to the point where we could use Chutney to exercise various Tor
964)     features as an automated integration test.

965)     </p>

966) 
967)     <p>
968)     <b>As part of your application for this project please submit a patch that
969)     expands Chutney.</b>
970)     </p>
971) 

972)     </li>

973) 

974)     <a id="torCleanup"></a>

975)     <li>

976)     <b>Tor Codebase Cleanup</b>

977)     <br>

978)     Effort Level: <i>Low to High, depending on subproject chosen</i>

979)     <br>

980)     Skill Level: <i>Medium to High</i>

981)     <br>

982)     Likely Mentors: <i>Nick (nickm)</i>

983)     <p>

984)     The Tor code is almost 10 years old in places, and we haven't always had
985)     enough time or wisdom to write things as well as we could have.  Our unit
986)     test coverage is shamefully low, and the dependency graph of our modules is
987)     shamefully convoluted . We could use refactoring and unit tests!  Please
988)     look through the Tor source code and look for ugly or tricky code or
989)     dependencies -- the uglier and trickier the better -- and think about how
990)     you could make the code look better, read better, and (subject to testing)
991)     work better.

992)     </p>

993) 

994)     <p>

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

1000)     </p>

1001) 

1002)     <p>

1003)     For a big project here, it would be great to pick one of the major
1004)     "submodules" of Tor -- path selection, node discovery, directory authority
1005)     operations, directory service -- and refactor its interface completely, to
1006)     minify and codify its points of contact with the rest of Tor.

1007)     </p>

1008) 
1009)     <p>
1010)     <b>As part of your application for this project please identify one of the
1011)     thorniest Tor functions and submit a patch refactoring it to be better. If
1012)     you find this to be difficult then this likely isn't the project for
1013)     you.</b>
1014)     </p>

1015)     </li>

1016) 

1017)     <a id="betterPluggableTransports"></a>
1018)     <li>
1019)     <b>Build Better Pluggable Transports</b>
1020)     <br>
1021)     Effort Level: <i>Medium to High</i>
1022)     <br>
1023)     Skill Level: <i>Medium</i>
1024)     <br>
1025)     Likely Mentors: <i>Steven (sjmurdoch)</i>
1026)     <p>
1027)     For Tor users in censored countries, we currently offer <a
1028)     href="https://www.torproject.org/projects/obfsproxy.html.en">obfsproxy</a>
1029)     bridges, which disguise Tor traffic by making it look random. This works
1030)     for many users, but it has disadvantages: firstly it does not disguise
1031)     packet size and secondly it looks like no real protocol. These weaknesses
1032)     may result in obfsproxy being blocked.
1033)     </p>
1034) 
1035)     <p>
1036)     The goal for this project will be to implement new pluggable transports,
1037)     which resolve these weaknesses and so can be deployed if/when obfsproxy is
1038)     blocked. Ideas for doing so include:
1039)       <ul>
1040)         <li>Impersonate a voice-over-IP protocol</li>
1041)         <li>Impersonate HTTP sufficiently well that traffic will go through a HTTP-only proxy</li>
1042)         <li>Implement <a href="http://cacr.uwaterloo.ca/techreports/2011/cacr2011-21.pdf">scanning resistance</a></a>
1043)       </ul>
1044)     </p>
1045) 
1046)     <a id="profileUDPTransport"></a>
1047)     <li>
1048)     <b>Profile UDP transport protocols</b>
1049)     <br>
1050)     Effort Level: <i>Medium to High</i>
1051)     <br>
1052)     Skill Level: <i>High</i>
1053)     <br>
1054)     Likely Mentors: <i>Steven (sjmurdoch)</i>
1055)     <p>
1056)     There are <a
1057)     href="https://research.torproject.org/techreports/datagram-comparison-2011-11-07.pdf">lots
1058)     of options</a> as to how Tor could send its data over UDP rather than TCP,
1059)     and some will likely perform significantly better than others. This project
1060)     will evaluate these options, so as to decide which should be used in future
1061)     versions of Tor. A first step will be to benchmark the various transport
1062)     protocols being considered, in terms of performance and also code quality,
1063)     including userspace TCP, <a
1064)     href="https://github.com/bittorrent/libutp">&mu;TP</a>, <a
1065)     href="http://en.wikipedia.org/wiki/Stream_Control_Transmission_Protocol">SCTP</a>
1066)     and <a href="http://curvecp.org/">CurveCP</a>. Initially these transport
1067)     protocols will be examined in isolation, but if the project progresses well
1068)     one or more could be integrated in Tor.
1069)     </p>
1070)     </li>
1071) 

1072)     <a id="httpsEverywhereRulesetTesting"></a>
1073)     <li>
1074)     <b>Incorporate Ruleset Testing into the HTTPS Everywhere release process</b>
1075)     <br>
1076)     Effort Level: <i>Medium</i>
1077)     <br>
1078)     Skill Level: <i>Medium</i>
1079)     <br>

1080)     Likely Mentors: <i>Peter Eckersley (pde), Micah Lee</i>

1081)     <p>
1082) Ondrej Mikle has implemented a codebase for testing HTTPS Everywhere rulesets
1083) by crawling pages that are affected by the ruleset (<a href="https://github.com/hiviah/https-everywhere-checker">repository</a>).
1084)     </p>
1085) 
1086)     <p>
1087) This codebase still has some rough edges that need to be smoothed over, but
1088) once those are done it should be incorporated into the HTTPS Everywhere build
1089) process, in order to improve the quality of our releases.
1090)     </p>
1091)     </li>
1092) 

1093)     <a id="censorshipAnalyzer"></a>
1094)     <li>
1095)     <b>Develop a Censorship Analyzer</b>
1096)     <br>
1097)     Effort Level: <i>Medium</i>
1098)     <br>
1099)     Skill Level: <i>Medium to High (depends on the implemented tests)</i>
1100)     <br>
1101)     Likely Mentors: <i>Philipp (phw)</i>
1102)     <p>
1103) Tor is documented to be blocked in <a
1104) href="https://censorshipwiki.torproject.org">several countries</a>. Analyzing
1105) these censorship incidents can be a tedious task; especially without access to
1106) machines inside the censoring networks. To make analysis easier, it would be
1107) great to have a lightweight analysis tool which can be run by censored users.
1108) This tool would conduct a number of networking tests and figure out if and how
1109) Tor could be blocked. The tool's final report should then somehow make it back
1110) to the Tor project.
1111)     </p>
1112) 
1113)     <p>
1114) The theory behind this tool is already <a

1115) href="http://www.cs.kau.se/philwint/pdf/foci2013.pdf">documented

1116) in a research paper</a>. What we now need is code! Implementing it would first
1117) mean getting familiar with <a href="https://ooni.torproject.org">OONI</a> and
1118) <a href="http://twistedmatrix.com/trac/">Twisted</a>. After that, the tool
1119) should be implemented as a number of OONI-specific networking tests.
1120)     </p>
1121)     </li>
1122) 

1123)     <li>
1124)     <b>Bring up new ideas!</b>

1125)     <br>

1126)     Don't like any of these? Look at the <a

1127)     href="/press/presskit/2008-12-19-roadmap-full.pdf">Tor development

1128)     roadmap</a> for more ideas, or just try out Tor, Vidalia, and Torbutton,
1129)     and find out what you think needs fixing.

1130)     Some of the <a href="<spectree>proposals">current proposals</a>

1131)     might also be short on developers.
1132)     </li>

1133) 

1134)     </ol>

1135) 

1136)     <a id="OtherCoding"></a>
1137)     <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>
1138)     <ol>
1139)     <li>Tor relays don't work well on Windows XP. On
1140)     Windows, Tor uses the standard <tt>select()</tt> system
1141)     call, which uses space in the non-page pool. This means
1142)     that a medium sized Tor relay will empty the non-page pool, <a

1143)     href="<wiki>doc/WindowsBufferProblems">causing

1144)     havoc and system crashes</a>. We should probably be using overlapped IO
1145)     instead. One solution would be to teach <a
1146)     href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
1147)     overlapped IO rather than select() on Windows, and then adapt Tor to
1148)     the new libevent interface. Christian King made a
1149)     <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good
1150)     start</a> on this in the summer of 2007.</li>

1151) 

1152)     <li>We need to actually start building our <a href="<page
1153)     docs/documentation>#DesignDoc">blocking-resistance design</a>. This involves
1154)     fleshing out the design, modifying many different pieces of Tor, adapting
1155)     <a href="<page projects/vidalia>">Vidalia</a> so it supports the
1156)     new features, and planning for deployment.</li>

1157) 

1158)     <li>We need a flexible simulator framework for studying end-to-end
1159)     traffic confirmation attacks. Many researchers have whipped up ad hoc
1160)     simulators to support their intuition either that the attacks work
1161)     really well or that some defense works great. Can we build a simulator
1162)     that's clearly documented and open enough that everybody knows it's
1163)     giving a reasonable answer? This will spur a lot of new research.
1164)     See the entry <a href="#Research">below</a> on confirmation attacks for
1165)     details on the research side of this task &mdash; who knows, when it's
1166)     done maybe you can help write a paper or three also.</li>

1167) 

1168)     <li>Tor 0.1.1.x and later include support for hardware crypto
1169)     accelerators via OpenSSL. It has been lightly tested and is
1170)     possibly very buggy.  We're looking for more rigorous testing,

1171)     performance analysis, and optimally, code fixes to OpenSSL and

1172)     Tor if needed.</li>

1173) 

1174)     <li>Write a <a
1175)     href="https://secure.wikimedia.org/wikipedia/en/wiki/Fuzz_testing">fuzzer</a>
1176)     for Tor to discover security vulnerabilities. Determine if there
1177)     are good fuzzing frameworks out there for what we want. Win fame by

1178)     getting credit when we put out a new release because of you!</li>

1179) 

1180)     <li>Tor uses TCP for transport and TLS for link
1181)     encryption. This is nice and simple, but it means all cells
1182)     on a link are delayed when a single packet gets dropped, and
1183)     it means we can only reasonably support TCP streams. We have a <a

1184)     href="<page docs/faq>#TransportIPnotTCP">list

1185)     of reasons why we haven't shifted to UDP transport</a>, but it would
1186)     be great to see that list get shorter. We also have a proposed <a

1187)     href="<specblob>proposals/100-tor-spec-udp.txt">specification

1188)     for Tor and
1189)     UDP</a> &mdash; please let us know what's wrong with it.</li>

1190) 

1191)     <li>We're not that far from having IPv6 support for destination addresses
1192)     (at exit nodes). If you care strongly about IPv6, that's probably the
1193)     first place to start.</li>

1194) 

1195)     <li>We need a way to generate the website diagrams (for example, the "How
1196)     Tor Works" pictures on the <a href="<page about/overview>">overview page</a>
1197)     from source, so we can translate them as UTF-8 text rather than edit
1198)     them by hand with Gimp. We might want to
1199)     integrate this as an wml file so translations are easy and images are
1200)     generated in multiple languages whenever we build the website.</li>

1201) 

1202)     <li>How can we make the various LiveCD/USB systems easier
1203)     to maintain, improve, and document?  One example is <a

1204)     href="https://tails.boum.org/">The Amnesic Incognito Live

1205)     System</a>.
1206)     </li>

1207) 

1208)     <li>
1209)     Another anti-censorship project is to try to make Tor
1210)     more scanning-resistant.  Right now, an adversary can identify <a

1211)     href="<specblob>proposals/125-bridges.txt">Tor bridges</a>

1212)     just by trying to connect to them, following the Tor protocol,
1213)     and seeing if they respond.  To solve this, bridges could <a
1214)     href="<svnprojects>design-paper/blocking.html#tth_sEc9.3">act like
1215)     webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
1216)     and not act like bridges until the user provides a bridge-specific key.
1217)     To start, check out Shane Pope's <a
1218)     href="http://dl.dropbox.com/u/37735/index.html">thesis and prototype</a>.
1219)     </li>

1220) 

1221)     </ol>

1222) 

1223)     <a id="Research"></a>
1224)     <h2><a class="anchor" href="#Research">Research</a></h2>
1225)     <ol>
1226)     <li>The "end-to-end traffic confirmation attack":
1227)     by watching traffic at Alice and at Bob, we can <a
1228)     href="http://freehaven.net/anonbib/#danezis:pet2004">compare
1229)     traffic signatures and become convinced that we're watching the same
1230)     stream</a>. So far Tor accepts this as a fact of life and assumes this
1231)     attack is trivial in all cases. First of all, is that actually true? How
1232)     much traffic of what sort of distribution is needed before the adversary
1233)     is confident he has won? Are there scenarios (e.g. not transmitting much)
1234)     that slow down the attack? Do some traffic padding or traffic shaping
1235)     schemes work better than others?</li>
1236)     <li>A related question is: Does running a relay/bridge provide additional
1237)     protection against these timing attacks? Can an external adversary that can't
1238)     see inside TLS links still recognize individual streams reliably?
1239)     Does the amount of traffic carried degrade this ability any? What if the
1240)     client-relay deliberately delayed upstream relayed traffic to create a queue
1241)     that could be used to mimic timings of client downstream traffic to make it
1242)     look like it was also relayed? This same queue could also be used for masking
1243)     timings in client upstream traffic with the techniques from <a
1244)     href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
1245)     but without the need for additional traffic. Would such an interleaving of
1246)     client upstream traffic obscure timings for external adversaries? Would the
1247)     strategies need to be adjusted for asymmetric links? For example, on
1248)     asymmetric links, is it actually possible to differentiate client traffic from
1249)     natural bursts due to their asymmetric capacity? Or is it easier than
1250)     symmetric links for some other reason?</li>
1251)     <li>Repeat Murdoch and Danezis's <a
1252)     href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
1253)     Oakland 05</a> on the current Tor network. See if you can learn why it
1254)     works well on some nodes and not well on others. (My theory is that the
1255)     fast nodes with spare capacity resist the attack better.) If that's true,
1256)     then experiment with the RelayBandwidthRate and RelayBandwidthBurst
1257)     options to run a relay that is used as a client while relaying the
1258)     attacker's traffic: as we crank down the RelayBandwidthRate, does the
1259)     attack get harder? What's the right ratio of RelayBandwidthRate to
1260)     actually capacity? Or is it a ratio at all? While we're at it, does a
1261)     much larger set of candidate relays increase the false positive rate
1262)     or other complexity for the attack? (The Tor network is now almost two
1263)     orders of magnitude larger than it was when they wrote their paper.) Be
1264)     sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
1265)     Clog the Queue</a> too.</li>
1266)     <li>The "routing zones attack": most of the literature thinks of
1267)     the network path between Alice and her entry node (and between the
1268)     exit node and Bob) as a single link on some graph. In practice,
1269)     though, the path traverses many autonomous systems (ASes), and <a
1270)     href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
1271)     that the same AS appears on both the entry path and the exit path</a>.
1272)     Unfortunately, to accurately predict whether a given Alice, entry,
1273)     exit, Bob quad will be dangerous, we need to download an entire Internet
1274)     routing zone and perform expensive operations on it. Are there practical
1275)     approximations, such as avoiding IP addresses in the same /8 network?</li>
1276)     <li>Other research questions regarding geographic diversity consider
1277)     the tradeoff between choosing an efficient circuit and choosing a random
1278)     circuit. Look at Stephen Rollyson's <a
1279)     href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
1280)     paper</a> on how to discard particularly slow choices without hurting
1281)     anonymity "too much". This line of reasoning needs more work and more
1282)     thinking, but it looks very promising.</li>
1283)     <li>Tor doesn't work very well when relays have asymmetric bandwidth
1284)     (e.g. cable or DSL). Because Tor has separate TCP connections between
1285)     each hop, if the incoming bytes are arriving just fine and the outgoing
1286)     bytes are all getting dropped on the floor, the TCP push-back mechanisms
1287)     don't really transmit this information back to the incoming streams.
1288)     Perhaps Tor should detect when it's dropping a lot of outgoing packets,
1289)     and rate-limit incoming streams to regulate this itself? I can imagine
1290)     a build-up and drop-off scheme where we pick a conservative rate-limit,
1291)     slowly increase it until we get lost packets, back off, repeat. We
1292)     need somebody who's good with networks to simulate this and help design
1293)     solutions; and/or we need to understand the extent of the performance
1294)     degradation, and use this as motivation to reconsider UDP transport.</li>
1295)     <li>A related topic is congestion control. Is our
1296)     current design sufficient once we have heavy use? Maybe
1297)     we should experiment with variable-sized windows rather
1298)     than fixed-size windows? That seemed to go well in an <a

1299)     href="http://www.psc.edu/index.php/hpn-ssh/638">ssh

1300)     throughput experiment</a>. We'll need to measure and tweak, and maybe
1301)     overhaul if the results are good.</li>
1302)     <li>Our censorship-resistance goals include preventing
1303)     an attacker who's looking at Tor traffic on the wire from <a
1304)     href="<svnprojects>design-paper/blocking.html#sec:network-fingerprint">distinguishing
1305)     it from normal SSL traffic</a>. Obviously we can't achieve perfect
1306)     steganography and still remain usable, but for a first step we'd like to
1307)     block any attacks that can win by observing only a few packets. One of
1308)     the remaining attacks we haven't examined much is that Tor cells are 512
1309)     bytes, so the traffic on the wire may well be a multiple of 512 bytes.
1310)     How much does the batching and overhead in TLS records blur this on the
1311)     wire? Do different buffer flushing strategies in Tor affect this? Could
1312)     a bit of padding help a lot, or is this an attack we must accept?</li>
1313)     <li>Tor circuits are built one hop at a time, so in theory we have the
1314)     ability to make some streams exit from the second hop, some from the
1315)     third, and so on. This seems nice because it breaks up the set of exiting
1316)     streams that a given relay can see. But if we want each stream to be safe,
1317)     the "shortest" path should be at least 3 hops long by our current logic, so
1318)     the rest will be even longer. We need to examine this performance / security
1319)     tradeoff.</li>
1320)     <li>It's not that hard to DoS Tor relays or directory authorities. Are client
1321)     puzzles the right answer? What other practical approaches are there? Bonus
1322)     if they're backward-compatible with the current Tor protocol.</li>
1323)     <li>Programs like <a

1324)     href="<page torbutton/index>">Torbutton</a> aim to hide

1325)     your browser's UserAgent string by replacing it with a uniform answer for
1326)     every Tor user. That way the attacker can't splinter Tor's anonymity set
1327)     by looking at that header. It tries to pick a string that is commonly used
1328)     by non-Tor users too, so it doesn't stand out. Question one: how badly
1329)     do we hurt ourselves by periodically updating the version of Firefox
1330)     that Torbutton claims to be? If we update it too often, we splinter the
1331)     anonymity sets ourselves. If we don't update it often enough, then all the
1332)     Tor users stand out because they claim to be running a quite old version
1333)     of Firefox. The answer here probably depends on the Firefox versions seen
1334)     in the wild. Question two: periodically people ask us to cycle through N
1335)     UserAgent strings rather than stick with one. Does this approach help,
1336)     hurt, or not matter? Consider: cookies and recognizing Torbutton users
1337)     by their rotating UserAgents; malicious websites who only attack certain
1338)     browsers; and whether the answers to question one impact this answer.
1339)     </li>
1340)     <li>How many bridge relays do you need to know to maintain
1341)     reachability? We should measure the churn in our bridges. If there is
1342)     lots of churn, are there ways to keep bridge users more likely to stay
1343)     connected?
1344)     </li>
1345)     </ol>

1346) 

1347)     <p>
1348)     <a href="<page about/contact>">Let us know</a> if you've made progress on any
1349)     of these!
1350)     </p>
1351)   </div>
1352)   <!-- END MAINCOL -->
1353)   <div id = "sidecol">
1354) #include "side.wmi"
1355) #include "info.wmi"
1356)   </div>
1357)   <!-- END SIDECOL -->
1358) </div>
1359) <!-- END CONTENT -->