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

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

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

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

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

49)     

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

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

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

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

58)     <a

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

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

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

62)     such as "Tor for Freedom!".</li>

63)     <li>Create a t-shirt design that incorporates "Congratulations!
64)     You are using Tor!" in any language.</li>

65)     </ol>

66)     

67)     <a id="opw"></a>

68)     <h2><a class="anchor" href="#opw">Outreach Program for Women</a></h2>

69)     
70)     <p>
71)     Several organisations, including Tor, are taking part in the <a
72)     href="https://live.gnome.org/OutreachProgramForWomen">2013 Outreach Program
73)     for Women</a>. This is a mentoring program similar to <a
74)     href="https://www.google-melange.com/gsoc/homepage/google/gsoc2012">Google
75)     Summer of Code</a> targeted at getting more women involved in open source.
76)     </p>
77)     
78)     <p>

79)     The program runs from January 2 through April 2, 2013. The application
80)     deadline is December 3, 2012 and it is best to start as early as possible
81)     preparing your application. Like GSoC the program involves a stipend so, if
82)     you're a woman interested in fighting surveillance and censorship around
83)     the world then let us know!

84)     </p>
85)     
86)     <p>
87)     To apply...
88)     </p>
89)     
90)     <ol>
91)       <li>Read up on the <a href="https://live.gnome.org/OutreachProgramForWomen">outreach program</a>.</li>
92)       <li>Look over our projects and task ideas below. If nothing there strikes your fancy then feel free to make one of your own.</li>
93)       <li>Join the <a href="https://www.torproject.org/about/contact.html.en#irc">#tor-dev irc channel</a> and introduce yourself!</li>
94)       <li>Contact the maintainer of the project that you're interested in contributing to, and talk with them about how to get started. Maintainers are listed in the table below. Note that you need to submit a patch or contribute in some way before you can apply to the program.</li>
95)       <li><a href="https://live.gnome.org/OutreachProgramForWomen#Send_in_an_Application">Send your application</a> to opw-list@gnome.org. Please be available and responsive throughout the application period so we can work with you on improving it.</li>
96)     </ol>
97)     

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

100)     

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

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

108)     </p>

109)     

110)     <table id="projects">
111)       <tr>
112)         <th>Name</th>
113)         <th>Category</th>
114)         <th>Language</th>
115)         <th>Activity</th>
116)         <th>Contributors</th>
117)       </tr>

118)       

119)       <tr>
120)         <td><a href="#project-tor">Tor</a></td>
121)         <td>Core</td>
122)         <td>C</td>
123)         <td>Heavy</td>

124)         <td>nickm, arma, Sebastian</td>

125)       </tr>

126)       

127)       <tr class="alt">

128)         <td>*<a href="#project-jtor">JTor</a></td>
129)         <td>Core</td>
130)         <td>Java</td>
131)         <td>None</td>

132)         <td>bleidl</td>

133)       </tr>

134)       

135)       <tr>

136)         <td><a href="#project-tbb">TBB</a></td>
137)         <td>Usability</td>

138)         <td>Sys Admin</td>
139)         <td>Moderate</td>

140)         <td>Erinn</td>

141)       </tr>

142)       

143)       <tr class="alt">

144)         <td><a href="#project-tails">Tails</a></td>

145)         <td>Usability</td>

146)         <td>Sys Admin</td>

147)         <td>Heavy</td>

148)         <td><a href="https://tails.boum.org/">#tails</a></td>

149)       </tr>

150)       

151)       <tr>

152)         <td><a href="#project-torsocks">Torsocks</a></td>
153)         <td>Usability</td>
154)         <td>C</td>

155)         <td>Heavy</td>
156)         <td>ioerror, nickm</td>

157)       </tr>

158)       

159)       <tr class="alt">

160)         <td>*<a href="#project-torouter">Torouter</a></td>
161)         <td>Usability</td>

162)         <td>Sys Admin</td>

163)         <td>Light</td>

164)         <td>ioerror</td>

165)       </tr>

166)       

167)       <tr>

168)         <td><a href="#project-vidalia">Vidalia</a></td>
169)         <td>User Interface</td>
170)         <td>C++, Qt</td>
171)         <td>Light</td>
172)         <td>chiiph</td>
173)       </tr>

174)       

175)       <tr class="alt">

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

179)         <td>Light</td>

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

182)       

183)       <tr>

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

187)         <td>Moderate</td>

188)         <td>n8fr8, ioerror</td>

189)       </tr>

190)       

191)       <tr class="alt">

192)         <td><a href="#project-torbutton">Torbutton</a></td>
193)         <td>Browser Add-on</td>
194)         <td>Javascript</td>
195)         <td>Moderate</td>
196)         <td>mikeperry</td>
197)       </tr>

198)       

199)       <tr>

200)         <td><a href="#project-torbirdy">TorBirdy</a></td>
201)         <td>Browser Add-on</td>
202)         <td>JavaScript</td>
203)         <td>Heavy</td>
204)         <td>Sukhbir (sukhe), ioerror</td>
205)       </tr>
206)       
207)       <tr class="alt">

208)         <td><a href="#project-obfsproxy">Obfsproxy</a></td>
209)         <td>Client Add-on</td>
210)         <td>C</td>
211)         <td>Moderate</td>
212)         <td>nickm, asn</td>
213)       </tr>

214)       

215)       <tr>

216)         <td>*<a href="#project-thandy">Thandy</a></td>
217)         <td>Updater</td>
218)         <td>Python</td>
219)         <td>Light</td>

220)         <td>chiiph, Erinn, nickm</td>

221)       </tr>

222)       

223)       <tr class="alt">

224)         <td>*<a href="#project-ooni-probe">Ooni Probe</a></td>
225)         <td>Scanner</td>
226)         <td>Python</td>
227)         <td>Moderate</td>

228)         <td>hellais, isis, ioerror</td>

229)       </tr>

230)       

231)       <tr>

232)         <td><a href="#project-shadow">Shadow</a></td>
233)         <td>Experimentation</td>
234)         <td>C, Python</td>
235)         <td>Moderate</td>
236)         <td>robgjansen</td>
237)       </tr>

238)       

239)       <tr class="alt">

240)         <td><a href="#project-torctl">TorCtl</a></td>
241)         <td>Library</td>
242)         <td>Python</td>

243)         <td>None</td>
244)         <td>aagbsn</td>

245)       </tr>

246)       

247)       <tr>

248)         <td>*<a href="#project-stem">Stem</a></td>
249)         <td>Library</td>
250)         <td>Python</td>
251)         <td>Heavy</td>

252)         <td>atagar, neena</td>

253)       </tr>

254)       

255)       <tr class="alt">

256)         <td><a href="#project-metrics">Metrics</a></td>
257)         <td>Client Service</td>
258)         <td>Java</td>
259)         <td>Heavy</td>
260)         <td>karsten</td>
261)       </tr>

262)       

263)       <tr>

264)         <td><a href="#project-atlas">Atlas</a></td>
265)         <td>Client Service</td>
266)         <td>JavaScript</td>
267)         <td>Moderate</td>
268)         <td>hellais</td>
269)       </tr>

270)       

271)       <tr class="alt">

272)         <td><a href="#project-torstatus">TorStatus</a></td>
273)         <td>Client Service</td>

274)         <td>Python, Django</td>

275)         <td>None</td>
276)         <td></td>
277)       </tr>

278)       

279)       <tr>

280)         <td><a href="#project-compass">Compass</a></td>
281)         <td>Client Service</td>
282)         <td>Python</td>
283)         <td>Heavy</td>
284)         <td>gsathya, karsten</td>
285)       </tr>
286)       

287)       <tr class="alt">

288)         <td><a href="#project-weather">Weather</a></td>
289)         <td>Client Service</td>
290)         <td>Python</td>

291)         <td>None</td>

292)         <td>kaner</td>
293)       </tr>

294)       

295)       <tr>

296)         <td><a href="#project-gettor">GetTor</a></td>
297)         <td>Client Service</td>
298)         <td>Python</td>

299)         <td>None</td>

300)         <td>kaner</td>

301)       </tr>

302)       

303)       <tr class="alt">

304)         <td><a href="#project-torcheck">TorCheck</a></td>
305)         <td>Client Service</td>
306)         <td>Python, Perl</td>
307)         <td>None</td>

308)         <td>ioerror</td>

309)       </tr>

310)       

311)       <tr>

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

314)         <td>Java, Python</td>

315)         <td>Moderate</td>

316)         <td>karsten, gsathya</td>

317)       </tr>

318)       

319)       <tr class="alt">

320)         <td><a href="#project-bridgedb">BridgeDB</a></td>
321)         <td>Backend Service</td>
322)         <td>Python</td>

323)         <td>None</td>

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

325)       </tr>

326)       

327)       <tr>

328)         <td><a href="#project-torflow">TorFlow</a></td>
329)         <td>Backend Service</td>
330)         <td>Python</td>

331)         <td>None</td>
332)         <td>aagbsn</td>

333)       </tr>

334)       

335)       <tr class="alt">

336)         <td>*<a href="#project-torbel">TorBEL</a></td>
337)         <td>Backend Service</td>
338)         <td>Python</td>
339)         <td>None</td>
340)         <td>Sebastian</td>
341)       </tr>
342)     </table>

343)     

344)     <sub>
345)     * Project is still in an alpha state.
346)     </sub>

347)     

348)     <br /><br />

349)     

350)     <a id="project-tor"></a>
351)     <h3>Tor (<a href="https://gitweb.torproject.org/tor.git">code</a>, <a
352)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Tor+Client&component=Tor+Relay&component=vidalia&order=priority">bug
353)     tracker</a>)</h3>

354)     

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

360)     

361)     <p>
362)     <b>Project Ideas:</b><br />

363)     <i><a href="#limitCapabilities">Run With Limited Capabilities</a></i><br />
364)     <i><a href="#torCleanup">Tor Codebase Cleanup</a></i><br />
365)     <i><a href="#httpsImersonation">HTTPS Server Impersonation</a></i><br />
366)     <i><a href="#chutneyExpansion">Make Chutney Do More, More Reliably</a></i>

367)     </p>

368)     

369)     <a id="project-jtor"></a>
370)     <h3><a href="https://github.com/brl/JTor/wiki">JTor</a> (<a
371)     href="https://github.com/brl/JTor">code</a>, <a
372)     href="https://github.com/brl/JTor/issues">bug
373)     tracker</a>)</h3>

374)     

375)     <p>
376)     Java implementation of Tor and successor to <a
377)     href="http://onioncoffee.sourceforge.net/">OnionCoffee</a>. This project
378)     isn't yet complete, and has been inactive since Fall 2010.
379)     </p>

380)     

381)     <a id="project-tbb"></a>
382)     <h3><a href="<page projects/torbrowser>">Tor Browser Bundle</a> (<a
383)     href="https://gitweb.torproject.org/torbrowser.git">code</a>, <a
384)     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
385)     tracker</a>)</h3>

386)     

387)     <p>
388)     The Tor Browser Bundle is an easy-to-use portable package of Tor, Vidalia,
389)     and Firefox preconfigured to work together out of the box. This is actively
390)     being worked on by Erinn Clark.
391)     </p>

392)     

393)     <!--

394)     <p>
395)     <b>Project Ideas:</b><br />
396)     <i><a href="#auditTBB">Audit Tor Browser Bundles for data leaks</a></i><br />
397)     <i><a href="#usabilityTesting">Usability testing of Tor</a></i>
398)     </p>

399)     -->

400)     

401)     <a id="project-tails"></a>

402)     <h3><a href="https://tails.boum.org/">The Amnesic Incognito Live System</a> (<a

403)     href="http://git.immerda.ch/?p=amnesia.git;a=summary">code</a>, <a

404)     href="https://tails.boum.org/bugs/">bug

405)     tracker</a>)</h3>

406)     

407)     <p>

408)     The Amnesic Incognito Live System is a live CD/USB distribution

409)     preconfigured so that everything is safely routed through Tor and leaves no
410)     trace on the local system. This is a merger of the Amnesia and <a
411)     href="http://www.anonymityanywhere.com/incognito/">Incognito</a> projects,
412)     and still under very active development.
413)     </p>

414)     

415)     <!--

416)     <p>
417)     <b>Project Ideas:</b><br />

418)     <i><a href="#tailsHiddenServicePetnames">Petname system for Tor hidden
419)     services</a></i><br />
420)     <i><a href="#tailsServer">Tails server: Self-hosted services behind
421)     Tails-powered Tor hidden services</a></i>

422)     </p>

423)     -->

424)     

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

430)     

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

436)     

437)     <!--

438)     <p>
439)     <b>Project Ideas:</b><br />
440)     <i><a href="#torsocksForOSX">Make torsocks/dsocks work on OS X</a></i>
441)     </p>

442)     -->

443)     

444)     <a id="project-torouter"></a>
445)     <h3><a

446)     href="<wiki>doc/Torouter">Torouter</a> (<a

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

449)     

450)     <p>
451)     Project to provide an easy-to-use, embedded Tor instance for routers. This

452)     had high activity in late 2010, but has since been rather quiet.

453)     </p>

454)     

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

457)     href="https://gitweb.torproject.org/vidalia.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=Vidalia&order=priority">bug
459)     tracker</a>)</h3>

460)     

461)     <p>
462)     The most commonly used user interface for Tor. Matt Edman started the
463)     project in 2006 and brought it to its current stable state. Development
464)     slowed for several years, though Tomás Touceda has since taken a lead with
465)     pushing the project forward.
466)     </p>

467)     

468)     <!--

469)     <p>
470)     <b>Project Ideas:</b><br />

471)     <i><a href="#vidaliaStatusEventInterface">Tor Controller Status Event Interface for Vidalia</a></i><br />
472)     <i><a href="#vidalia-hidden-service-panel">Torrc plugin and improved hidden service configuration panel</a></i>

473)     </p>

474)     -->

475)     

476)     <a id="project-arm"></a>
477)     <h3><a href="http://www.atagar.com/arm/">Arm</a> (<a

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

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

481)     

482)     <p>
483)     Command-line monitor for Tor. This has been under very active development
484)     by its author, Damian Johnson, since early 2009 to make it a better
485)     general-purpose controller for *nix environments.
486)     </p>

487)     

488)     <!--

489)     <p>
490)     <b>Project Ideas:</b><br />

491)     <i><a href="#armClientMode">Client Mode Use Cases for Arm</a></i><br />
492)     <i><a href="#armGui">GUI for Arm</a></i>

493)     </p>

494)     -->

495)     

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

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

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

501)     

502)     <p>
503)     Provides Tor on the Android platform. This was under very active
504)     development up through Fall 2010, after which things have been quiet.
505)     </p>

506)     

507)     <!--

508)     <p>
509)     <b>Project Ideas:</b><br />

510)     <i><a href="#orbot-torbutton">TorButton for Mobile Firefox 4 or Custom Browser on Android</a></i><br />
511)     <i><a href="#orbot-userInterface">Build a better user interface for Orbot</a></i><br />

512)     <i><a href="#orbot-optimisation">Core Tor mobile optimisation</a></i>

513)     </p>

514)     -->

515)     

516)     <a id="project-torbutton"></a>
517)     <h3><a href="<page torbutton/index>">Torbutton</a> (<a
518)     href="https://gitweb.torproject.org/torbutton.git">code</a>, <a
519)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torbutton&order=priority">bug
520)     tracker</a>)</h3>

521)     

522)     <p>
523)     Firefox addon that addresses many of the client-side threats to browsing
524)     the Internet anonymously. Mike has since continued to adapt it to new
525)     threats, updated versions of Firefox, and possibly <a
526)     href="https://blog.torproject.org/blog/google-chrome-incognito-mode-tor-and-fingerprinting">Chrome
527)     as well</a>.
528)     </p>

529)     

530)     <a id="project-torbirdy"></a>
531)     <h3>TorBirdy (<a
532)     href="https://github.com/ioerror/torbirdy">code</a>, <a
533)     href="https://trac.torproject.org/projects/tor/wiki/torbirdy/dev">bug
534)     tracker</a>)</h3>
535)     
536)     <p>
537)     TorBirdy is Torbutton for Thunderbird and related Mozilla mail clients.
538)     </p>
539)     
540)     <p>
541)     <b>Project Ideas:</b><br />
542)     <i><a href="#improveTorbirdy">Improving TorBirdy</a></i><br />
543)     </p>
544)     

545)     <a id="project-obfsproxy"></a>
546)     <h3><a href="https://gitweb.torproject.org/obfsproxy.git/tree/HEAD:/doc">Obfsproxy</a> (<a
547)     href="https://gitweb.torproject.org/obfsproxy.git">code</a>, <a
548)     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
549)     tracker</a>)</h3>

550)     

551)     <p>
552)     A proxy that shapes Tor traffic, making it harder for censors to detect and
553)     block Tor.
554)     </p>

555)     

556)     <!--

557)     <p>
558)     <b>Project Ideas:</b><br />
559)     <i><a href="#obfsproxy-new-transports">New and innovative pluggable transports</a></i><br />
560)     <i><a href="#obfsproxy-scanning-measures">Defensive bridge active scanning measures</a></i><br />
561)     <i><a href="#obfsproxy-fuzzer">Fuzzer for the Tor protocol</a></i>
562)     </p>

563)     -->

564)     

565)     <a id="project-thandy"></a>
566)     <h3>Thandy (<a
567)     href="https://gitweb.torproject.org/thandy.git">code</a>)</h3>

568)     

569)     <p>
570)     Updater for Tor. The project began in the Summer of 2008 but wasn't
571)     completed. Recently interest in it has been rekindled and many aspects of
572)     its design (including the language it'll be in) are currently in flux.
573)     </p>

574)     

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

580)     

581)     <p>
582)     Censorship scanner, checking your local connection for blocked or modified
583)     content.
584)     </p>

585)     

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

591)     

592)     <p>
593)     Shadow is a discrete-event network simulator that runs the real
594)     Tor software as a plug-in. Shadow is open-source software that enables
595)     accurate, efficient, controlled, and repeatable Tor experimentation.
596)     </p>

597)     

598)     <a id="project-torctl"></a>
599)     <h3>TorCtl (<a
600)     href="https://gitweb.torproject.org/pytorctl.git">code</a>, <a
601)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Torctl&order=priority">bug
602)     tracker</a>)</h3>

603)     

604)     <p>
605)     Python bindings and utilities for using the Tor control port. It has been
606)     stable for several years, with only minor revisions.
607)     </p>

608)     

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

610)     <h3><a href="https://stem.readthedocs.org/en/latest/index.html">Stem</a> (<a

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

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

613)     tracker</a>)</h3>

614)     

615)     <p>
616)     Python controller library with a similar scope to TorCtl, but with better
617)     testing, documentation, and API. This project is not yet feature complete.
618)     </p>

619)     

620)     <p>
621)     <b>Project Ideas:</b><br />

622)     <i><a href="#stemUsability">Stem Usability Improvements</a></i>

623)     </p>

624)     

625)     <a id="project-metrics"></a>
626)     <h3><a href="https://metrics.torproject.org/">Metrics</a> (code: <a
627)     href="https://gitweb.torproject.org/metrics-db.git">db</a>, <a
628)     href="https://gitweb.torproject.org/metrics-utils.git">utils</a>, <a
629)     href="https://gitweb.torproject.org/metrics-web.git">web</a>, <a
630)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Metrics&order=priority">bug
631)     tracker</a>)</h3>

632)     

633)     <p>
634)     Processing and analytics of consensus data, provided to users via the
635)     metrics portal. This has been under active development for several years by
636)     Karsten Loesing.
637)     </p>

638)     

639)     <p>
640)     <b>Project Ideas:</b><br />
641)     <i><a href="#metricsSearch">Searchable Tor descriptor and Metrics data archive</a></i> (Python/Django?)
642)     </p>

643)     

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

647)     

648)     <p>
649)     Atlas is a web application to discover Tor relays and bridges. It provides
650)     useful information on how relays are configured along with graphics about
651)     their past usage. This is the third evolution of the TorStatus application.
652)     </p>

653)     

654)     <a id="project-torstatus"></a>

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

656)     href="https://gitweb.torproject.org/torstatus.git">code</a>)</h3>

657)     

658)     <p>
659)     Portal providing an overview of the Tor network, and details on any of its
660)     current relays. Though very actively used, this project has been

661)     unmaintained for a long while. The <a
662)     href="https://svn.torproject.org/svn/torstatus/trunk/">original
663)     codebase</a> was written in PHP, and students from Wesleyan wrote the new
664)     Django counterpart.

665)     </p>

666)     

667)     <a id="project-compass"></a>
668)     <h3><a href="https://compass.torproject.org/">Compass</a> (<a
669)     href="https://gitweb.torproject.org/compass.git">code</a>, <a
670)     href="https://trac.torproject.org/projects/tor/query?status=accepted&status=assigned&status=needs_review&status=new&status=reopened&component=Compass&order=priority">bug
671)     tracker</a>)</h3>
672)     
673)     <p>
674)     Compass is a web and command line application that filters and
675)     aggregates the Tor relays based on various attributes.
676)     </p>
677)     

678)     <p>
679)     <b>Project Ideas:</b><br />
680)     <i><a href="#compassRefactoring">Compass Refactoring</a></i>
681)     </p>
682)     

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

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

685)     href="https://gitweb.torproject.org/weather.git">code</a>, <a
686)     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
687)     tracker</a>)</h3>

688)     

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

695)     

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

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

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

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

701)     

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

706)     

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

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

709)     href="https://svn.torproject.org/svn/check/trunk/">code</a>, <a
710)     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
711)     tracker</a>)</h3>

712)     

713)     <p>
714)     Provides a simple site for determining if the visitor is using Tor or not.
715)     This has been relatively unchanged for quite a while.
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>)</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-bridgedb"></a>

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

731)     href="https://gitweb.torproject.org/bridgedb.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=BridgeDB&order=priority">bug
733)     tracker</a>)</h3>

734)     

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

739)     

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

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

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

745)     

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

754)     

755)     <a id="project-torbel"></a>
756)     <h3><a

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

759)     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
760)     tracker</a>)</h3>

761)     

762)     <p>
763)     The Tor Bulk Exitlist provides a method of identifying if IPs belong to
764)     exit nodes or not. This is a replacement for TorDNSEL which is a stable
765)     (though unmaintained) Haskell application for this purpose. The initial
766)     version of TorBEL was started in GSOC 2010 but since then the project has
767)     been inactive.
768)     </p>

769)     

770)     <a id="Coding"></a>
771)     <a id="Summer"></a>

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

773)     

774)     <p>

775)     You may find some of these projects to be good ideas for <a href="<page
776)     about/gsoc>">Google Summer of Code</a> and the <a
777)     href="https://live.gnome.org/OutreachProgramForWomen">Outreach Program for
778)     Women</a>. We have labelled each idea with how useful it would be to the
779)     overall Tor project (priority), how much work we expect it would be (effort
780)     level), how much clue you should start with (skill level), and which of our
781)     <a href="<page about/corepeople>">core developers</a> would be good
782)     mentors. If one or more of these ideas looks promising to you, please <a

783)     href="<page about/contact>">contact us</a> to discuss your plans rather than
784)     sending blind applications. You may also want to propose your own project
785)     idea &mdash; which often results in the best applications.
786)     </p>

787)     

788)     <ol>

789)     

790)     <a id="improveTorbirdy"></a>
791)     <li>
792)     <b>Improving TorBirdy</b>
793)     <br>
794)     Priority: <i>High</i>
795)     <br>
796)     Effort Level: <i>High</i>
797)     <br>
798)     Skill Level: <i>Medium to High</i>
799)     <br>
800)     Likely Mentors: <i>Sukhbir, Jacob</i>
801)     <p>
802)     TorBirdy is Torbutton for Thunderbird, Icedove and related Mozilla mail
803)     clients.
804)     </p>
805)     <p>
806)     TorBirdy is under active development and is available from <a
807)     href="https://trac.torproject.org/projects/tor/wiki/torbirdy">our wiki</a>
808)     and <a
809)     href="https://addons.mozilla.org/en-US/thunderbird/addon/torbirdy/">mozilla's
810)     addons site</a>.
811)     </p>
812)     
813)     <p>
814)     The goal of this project is to improve TorBirdy by:
815)     </p>
816)     
817)     <ul>
818)       <li>
819)         Writing a Thunderbird patch to plug known leaks. We have already <a
820)         href="https://bugzilla.mozilla.org/show_bug.cgi?id=776397">submitted a
821)         patch to Thunderbird</a> but we anticipate there will be much more work
822)         required before it is accepted, possibly involving rewriting the entire
823)         patch; this appears trivial, but it is not, as we are proposing a
824)         completely new privacy-safe message-ID header generation algorithm for
825)         Thunderbird.
826)       </li>
827)       <li>
828)         Implementing a JavaScript HTTP proxy (see the <a
829)         href="https://trac.torproject.org/projects/tor/ticket/6958">ticket</a>)
830)       </li>
831)       <li>
832)         Auditing TorBirdy for leaks and for use with other add-ons (as an
833)         example see its <a
834)         href="https://trac.torproject.org/projects/tor/ticket/6319">ticket</a>)
835)       </li>
836)     </ul>
837)     
838)     <p>
839)     A student undertaking this project should have some C++ and JavaScript
840)     development experience. Previous experience with Firefox/Thunderbird
841)     extension development is a plus, but not required.
842)     </p>
843)     </li>
844)     
845)     <!--

846)     <a id="auditTBB"></a>

847)     <li>

848)     <b>Audit Tor Browser Bundles for data leaks</b>

849)     <br>

850)     Priority: <i>High</i>

851)     <br>

852)     Effort Level: <i>High</i>

853)     <br>

854)     Skill Level: <i>Medium</i>

855)     <br>

856)     Likely Mentors: <i>Jacob</i>

857)     <p>The Tor Browser Bundle incorporates Tor, Firefox, Polipo, and the Vidalia

858)     user interface (and optionally the <a href="http://pidgin.im/">Pidgin</a>
859)     Instant Messaging client). Components are pre-configured to operate in a
860)     secure way, and it has very few dependencies on the installed operating
861)     system. It has therefore become one of the most easy to use, and popular,

862)     ways to use Tor on Windows.</p>
863)     <p>This project is to identify all of the traces left behind by
864)     using a Tor Browser Bundle on Windows, Mac OS X, or Linux.  Developing
865)     ways to stop, counter, or remove these traces is a final step.</p>
866)     <p>Students should be familiar with operating system analysis,

867)     application development on one or preferably all of Windows, Linux,

868)     and Mac OS X, and be comfortable with C/C++ and shell scripting.</p>

869)     <p>Since the core of this project is researching and auditing TBB this is
870)     not likely to be a good GSoC project.</p>

871)     </li>

872)     -->

873)     

874)     <!--

875)     <a id="firewallProbeTool"></a>
876)     <li>
877)     <b>Develop a fully automatic firewall-probing system</b>
878)     <br>
879)     Priority: <i>High</i>
880)     <br>
881)     Effort Level: <i>Medium to High</i>
882)     <br>
883)     Skill Level: <i>High</i>
884)     <br>

885)     Likely Mentors: <i>Robert Ransom, Jacob</i>

886)     <p>We would like to have a fully automatic firewall-probing system for
887)     blocking systems with no long-term state (i.e. firewalls that can
888)     examine each connection, but do not change their behaviour for future
889)     connections based on the traffic they have seen).</p>
890)     <p>Ideally, volunteers would only need to set up one or more test servers,
891)     and run the probe client program on a publicly accessible computer
892)     behind the firewall.</p>
893)     <p>The test tool should:</p>
894)     <ul>
895)     <li>generate packet captures on both ends (and send them out to the
896)         extent possible),</li>
897)     <li>cycle through all the SSL configurations we might want to test
898)         through a censorship device, and</li>
899)     <li>also test some other protocols to see whether they are allowed
900)         through the firewall (IMAP and other mail protocols, BitTorrent,
901)         DTLS, etc.).</li>
902)     </ul>
903)     </li>

904)     -->

905)     

906)     <!--

907)     <a id="orbot-torbutton"></a>
908)     <li>
909)     <b>TorButton for Mobile Firefox 4 or Custom Browser on Android</b>
910)     <br>
911)     Priority: <i>High</i>
912)     <br>
913)     Effort Level: <i>High</i>
914)     <br>
915)     Skill Level: <i>High</i>
916)     <br>

917)     Likely Mentors: <i>Jake</i>

918)     <p>Initial work has been done on implementing a proxy-setting add-on for
919)     Firefox on Android (see <a
920)     href="https://github.com/guardianproject/ProxyMob">ProxyMob</a>), but a
921)     full port of TorButton needs to be done (dependent upon Firefox 4 port of
922)     TorButton). The other approach is to implement a custom &quot;Tor
923)     Browser&quot; based on Firefox or Webkit browser. See <a
924)     href="http://code.google.com/p/torora/wiki/Android">Torora</a> for progress
925)     on this so far.</p>
926)     </li>

927)     -->

928)     

929)     <!--

930)     <a id="obfsproxy-new-transports"></a>
931)     <li>
932)     <b>New and innovative pluggable transports</b>
933)     <br>
934)     Priority: <i>High</i>
935)     <br>
936)     Effort Level: <i>High</i>
937)     <br>
938)     Skill Level: <i>High</i>
939)     <br>

940)     Likely Mentors: <i>asn, Steven</i>

941)     <p>Not-very-smart transports like ROT13 and base64 are nice but not super
942)     interesting. Other ideas like bittorrent transports might be relevant,
943)     but you will have to provide security proofs on why they are harder to
944)     detect and block than other less-sophisticated transports.</p>

945)     

946)     <p>The whole point of this project, though, is to come up with new
947)     transports that we haven't already thought of. Be creative.</p>

948)     

949)     <p>Bonus points if your idea is interesting and still implementable
950)     through the summer period.</p>

951)     

952)     <p>More bonus points if it's implemented on top of obfsproxy, or if your
953)     implementation has a pluggable transport interface on top of it (as
954)     specified <a href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/180-pluggable-transport.txt">here</a>).</p>
955)     </li>

956)     -->

957)     

958)     <!--

959)     <a id="obfsproxy-scanning-measures"></a>
960)     <li>
961)     <b>Defensive bridge active scanning measures</b>
962)     <br>
963)     Priority: <i>High</i>
964)     <br>
965)     Effort Level: <i>High</i>
966)     <br>
967)     Skill Level: <i>High</i>
968)     <br>
969)     Likely Mentors: <i>asn</i>
970)     <p>Involves providing good answers to <a
971)     href="https://lists.torproject.org/pipermail/tor-dev/2011-November/003073.html">this
972)     thread</a> as well as concrete implementation plans for it.</p>

973)     

974)     <p>This also involves implementing proposals <a
975)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/189-authorize-cell.txt">189</a>
976)     and <a
977)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/190-shared-secret-bridge-authorization.txt">190</a>.</p>
978)     </li>

979)     -->

980)     

981)     <a id="limitCapabilities"></a>
982)     <li>
983)     <b>Run With Limited Capabilities</b>
984)     <br>
985)     Priority: <i>Medium to High</i>
986)     <br>
987)     Effort Level: <i>Medium to High</i>
988)     <br>
989)     Skill Level: <i>High</i>
990)     <br>
991)     Likely Mentors: <i>Nick (nickm)</i>
992)     <p>
993)     Many modern operating systems give a running program the ability to drop
994)     capabilities that it no longer needs, and other ways for a program to run
995)     pieces of itself in a sandbox with diminished privileges.
996)     </p>
997)     
998)     <p>
999)     We'd like to do this with Tor, to improve its resistance to attacks.  The
1000)     easiest areas to address would be on systems like <a
1001)     href="https://lwn.net/Articles/475361/">recent Linux kernels</a> that make
1002)     it easy to drop or restrict the set of syscalls that a program can invoke.
1003)     That's a great project, but probably not big enough for an internship just
1004)     on its own.  For that, we'd want to make progress on at least multiple
1005)     platforms, or look into refactoring Tor into pieces that need more
1006)     privileges and pieces that don't with an eye towards sandboxing them
1007)     differently.
1008)     </p>
1009)     
1010)     <p>
1011)     See tickets <a href="https://trac.torproject.org/7005">#7005</a> and <a
1012)     href="https://trac.torproject.org/5219">#5219</a>, and their descendants,
1013)     for more information.
1014)     </p>
1015)     </li>
1016)     
1017)     <a id="torCleanup"></a>
1018)     <li>
1019)     <b>Tor Codebase Cleanup</b>
1020)     <br>
1021)     Priority: <i>Medium to High</i>
1022)     <br>
1023)     Effort Level: <i>Low to High, depending on subproject chosen</i>
1024)     <br>
1025)     Skill Level: <i>Medium to High</i>
1026)     <br>
1027)     Likely Mentors: <i>Nick (nickm)</i>
1028)     <p>
1029)     The Tor code is almost 10 years old in places, and we haven't always had
1030)     enough time or wisdom to write things as well as we could have.  Our unit
1031)     test coverage is shamefully low, and the dependency graph of our modules is
1032)     shamefully convoluted . We could use refactoring and unit tests!  Please
1033)     look through the Tor source code and look for ugly or tricky code or
1034)     dependencies -- the uglier and trickier the better -- and think about how
1035)     you could make the code look better, read better, and (subject to testing)
1036)     work better.
1037)     </p>
1038)     
1039)     <p>
1040)     If this is for a fun side-project, it would be great for you to work on
1041)     anything that can be made better and more tested.  For an internship-level
1042)     position, we'd hope that you could find a number of particularly tricky or
1043)     knotty piece of the code to clean up, and aim for resolving the ugliest
1044)     problems, not necessarily the easiest.
1045)     </p>
1046)     
1047)     <p>
1048)     For a big project here, it would be great to pick one of the major
1049)     "submodules" of Tor -- path selection, node discovery, directory authority
1050)     operations, directory service -- and refactor its interface completely, to
1051)     minify and codify its points of contact with the rest of Tor.
1052)     </p>
1053)     </li>
1054)     
1055)     <a id="httpsImersonation"></a>
1056)     <li>
1057)     <b>HTTPS Server Impersonation</b>
1058)     <br>
1059)     Priority: <i>Medium</i>
1060)     <br>
1061)     Effort Level: <i>Medium to High</i>
1062)     <br>
1063)     Skill Level: <i>Medium to High</i>
1064)     <br>
1065)     Likely Mentors: <i>Nick (nickm)</i>
1066)     <p>
1067)     We have an open proposal for a way to make Tor bridges avoid censorship by
1068)     impersonating an HTTPS server.  Specifically, we need to hack some popular
1069)     SSL "reverse proxy" (your choice) so that it relays regular web connections
1070)     to an HTTP server, but certain connections to a local Tor process.  <a
1071)     href="https://gitweb.torproject.org/torspec.git/blob_plain/HEAD:/proposals/203-https-frontend.txt">Proposal
1072)     203</a> has a general design sketch.
1073)     </p>
1074)     </li>
1075)     
1076)     <a id="chutneyExpansion"></a>
1077)     <li>
1078)     <b>Make Chutney Do More, More Reliably</b>
1079)     <br>
1080)     Priority: <i>Medium</i>
1081)     <br>
1082)     Effort Level: <i>Medium to High, depending on scope of project</i>
1083)     <br>
1084)     Skill Level: <i>Medium</i>
1085)     <br>
1086)     Likely Mentors: <i>Nick (nickm)</i>
1087)     <p>
1088)     We have a little Python tool called <a
1089)     href="https://gitweb.torproject.org/nickm/chutney.git">Chutney</a> for
1090)     making small local test networks.  It's small, not widely used, and not as
1091)     automated as it could be.
1092)     </p>
1093)     
1094)     <p>
1095)     It would be great to see chutney extended and a set of supporting tests
1096)     built to the point where we could use Chutney to exercise various Tor
1097)     features as an automated integration test.
1098)     </p>
1099)     </li>
1100)     

1101)     <a id="stemUsability"></a>
1102)     <li>
1103)     <b>Stem Usability Improvements</b>
1104)     <br>
1105)     Priority: <i>Medium</i>
1106)     <br>
1107)     Effort Level: <i>Medium</i>
1108)     <br>
1109)     Skill Level: <i>Medium</i>
1110)     <br>
1111)     Likely Mentors: <i>Damian (atagar)</i>
1112)     <p>
1113)     <a href="https://stem.readthedocs.org/en/latest/index.html">Stem</a> is a
1114)     python controller library for tor. Like it's predecessor, <a
1115)     href="#project-torctl">TorCtl</a>, it uses tor's <a
1116)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/control-spec.txt">control
1117)     protocol</a> to help developers program against the tor process, enabling
1118)     them to build things similar to <a href="#project-vidalia">Vidalia</a> and
1119)     <a href="#project-arm">arm</a>.
1120)     </p>
1121)     
1122)     <p>
1123)     While TorCtl provided a fine first draft for this sort of functionality,
1124)     it has not proved to be extensible nor maintainable. Stem is a rewrite of
1125)     TorCtl with a heavy focus on testing, documentation, and providing a
1126)     developer friendly API.
1127)     </p>
1128)     
1129)     <p>
1130)     Stem is very nearly feature complete but presently has no users. We
1131)     want to change that prior to making our first release for a couple
1132)     reasons...
1133)     </p>
1134)     
1135)     <ul>
1136)       <li>Make sure that we have a reasonably good API, and improve the rough
1137)       edges that hurt its usability.</li>
1138)       <li>Provide examples for how stem can be used.</li>
1139)     </ul>
1140)     
1141)     <p>
1142)     This project involves several tasks...
1143)     </p>
1144)     
1145)     <ol>
1146)       <li>Move stem's site to Tor's website (<a href="https://trac.torproject.org/projects/tor/ticket/7324">ticket</a>)</li>
1147)       <li>Set up Piwik for our site (<a href="https://trac.torproject.org/projects/tor/ticket/7424">ticket</a>)</li>
1148)       <li>Come up with a better, more developer friendly "Module Overview" for our documentation (<a href="https://stem.readthedocs.org/en/latest/api/control.html">example page</a>). For instance, it would be nice to provide interlinking between the overview and the classes/methods that it lists. This will probably involve asking for help from the <a href="http://sphinx-doc.org/">Sphinx user list</a>.</li>
1149)       <li>Finally get your hands dirty using stem. We want to expand stem's <a href="https://stem.readthedocs.org/en/latest/tutorial.html">tutorial page</a> with more examples. To do this you'll want to both brainstorm some of your own and contact the <a href="https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev/">tor-dev@ email list</a> to solicit ideas. This last step is pretty open ended, so go nuts with whatever you think will improve stem's usability!</li>
1150)     </ol>
1151)     </li>
1152)     

1153)     <a id="compassRefactoring"></a>
1154)     <li>
1155)     <b>Compass Refactoring</b>
1156)     <br>
1157)     Priority: <i>Medium</i>
1158)     <br>
1159)     Effort Level: <i>Medium</i>
1160)     <br>
1161)     Skill Level: <i>Medium</i>
1162)     <br>
1163)     Likely Mentors: <i>gsathya, karsten</i>
1164)     <p>
1165)     Compass was first designed to be a cli app and then hacked into a web app.
1166)     The codebase needs to be refactored such that the main processing code is
1167)     separated from the display functions(probably into separate files) and made
1168)     modular so that adding more features (<a
1169)     href="https://trac.torproject.org/6612">#6612</a>) is easy. For example, the
1170)     main processing logic could be in compass.py, whereas print_groups() and other
1171)     display related functions could be part of a separate cli.py; web.py would also
1172)     have to modified to make use of this new modular code. Bonus points for adding
1173)     features to compass(<a href="https://trac.torproject.org/6619">#6619</a>, <a
1174)     href="https://trac.torproject.org/6612">#6612</a>, <a
1175)     href="https://trac.torproject.org/6728">#6728</a>).
1176)     </p>
1177)     </li>
1178)     

1179)     <!--

1180)     <a id="stemPathsupport"></a>
1181)     <li>
1182)     <b>Stem PathSupport Capabilities</b>
1183)     <br>
1184)     Priority: <i>High</i>
1185)     <br>
1186)     Effort Level: <i>High</i>
1187)     <br>
1188)     Skill Level: <i>Medium</i>
1189)     <br>
1190)     Likely Mentors: <i>Damian (atagar)</i>
1191)     <p><a
1192)     href="https://trac.torproject.org/projects/tor/wiki/doc/stem">Stem</a> is a
1193)     python controller library for tor. Like it's predecessor, <a
1194)     href="#project-torctl">TorCtl</a>, it uses tor's <a
1195)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/control-spec.txt">control
1196)     protocol</a> to help developers program against the tor process, enabling
1197)     them to build things similar to <a href="#project-vidalia">Vidalia</a> and
1198)     <a href="#project-arm">arm</a>.</p>

1199)     

1200)     <p>While TorCtl provided a fine first draft for this sort of functionality,
1201)     it has not proved to be extensible nor maintainable. Stem is a rewrite of
1202)     TorCtl with a heavy focus on testing, documentation, and providing a
1203)     developer friendly API.</p>

1204)     

1205)     <p>At the moment stem is still very much incomplete, missing several pieces
1206)     of functionality that TorCtl provides. This is a project to fix that by
1207)     porting TorCtl's <a
1208)     href="https://gitweb.torproject.org/pytorctl.git/blob/HEAD:/PathSupport.py">PathSupport
1209)     module</a> to stem, writing tests for it, and migrate a couple clients to
1210)     use it.</p>

1211)     

1212)     <p>PathSupport provides applications with programmatic control over how
1213)     tor's circuits are built, for instance letting you exit from particular
1214)     relays. This is used by projects like <a href="#project-torbel">TorBEL</a>,
1215)     <a href="#project-torflow">the Bandwidth Scanners, and SoaT</a>.</p>

1216)     

1217)     <p>This project can be broken into three parts...</p>

1218)     

1219)     <ol style="list-style-type: decimal">
1220)       <li><p>Look at PathSupport's clients to figure out how it is used and
1221)       come up with the API that we will use for stem. Note that the goal if
1222)       this project is <b>not</b> to simply copy PathSupport, but to make it
1223)       better. This task would ideally be done as part of writing the GSoC
1224)       application.</p></li>
1225)       <li><p>Implement the PathSupport counterpart for stem. This should be
1226)       done in an incremental fashion, writing the feature, tests, and going
1227)       through a code review before moving on. I'll be pretty anal about making
1228)       it as good as we can during these code reviews so plan for this to take a
1229)       while. ;)</p></li>
1230)       <li><p>The real test of the API that you've developed will come when we
1231)       use it in some real applications. Try to migrate a TorCtl client or two
1232)       to stem, filling in functionality that we're missing and improving our
1233)       API as we discover issues. A particularly good client to start with would
1234)       be TorBEL.</p></li>
1235)     </ol>

1236)     

1237)     <p><b>
1238)     Upon reflection this is not an especially good project for this year's GSoC. You are still perfectly wecome to apply for this project, but <a href="https://trac.torproject.org/projects/tor/wiki/doc/stem">other stem related tasks</a> such as implementing a general controller, descriptor fetching, and client migrations would be better. For the discussion that lead to this see <a href="http://archives.seul.org/or/dev/Apr-2012/msg00006.html">this thread</a>.
1239)     </b></p>
1240)     </li>

1241)     -->

1242)     

1243)     <!--

1244)     <a id="orbot-userInterface"></a>
1245)     <li>
1246)     <b>Build a better user interface for Orbot</b>
1247)     <br>
1248)     Priority: <i>High</i>
1249)     <br>
1250)     Effort Level: <i>Medium</i>
1251)     <br>
1252)     Skill Level: <i>Medium</i>
1253)     <br>

1254)     Likely Mentors: <i>Jake</i>

1255)     <p>Improved home screen to show confirmation of connection (via a TorCheck
1256)     API call), better statistics about data transferred (up/down), number of
1257)     circuits connected, quality of connection and so on. The &quot;Tether
1258)     Wifi&quot; Android application is a good model to follow in how it shows a
1259)     realtime count of bytes transferred as well as notifications when wifi
1260)     clients connect. In addition, better handling of Tor system and error
1261)     messages would also be very helpful, include use of standard Android
1262)     operating systems notifications. The addition of a wizard or tutorial
1263)     walkthrough for novice users to explain to them exactly what is and what is
1264)     not anonymized or protected would greatly improve the likelihood they will
1265)     use Orbot correctly. All of this should work on the range of screens and
1266)     device types now offered for Android, from 2&quot; phone to 10&quot;
1267)     Tablet.</p>
1268)     </li>

1269)     -->

1270)     

1271)     <!--

1272)     <a id="user-space-transport"></a>
1273)     <li>
1274)     <b>Integrating Tor with user-space transport protocol libraries</b>
1275)     <br>
1276)     Priority: <i>Medium to High</i>
1277)     <br>
1278)     Effort Level: <i>High</i>
1279)     <br>
1280)     Skill Level: <i>High</i>
1281)     <br>
1282)     Likely Mentors: <i>Steven</i>
1283)     <p>Tor currently sends data over TCP links between nodes. <a
1284)     href="http://static.usenix.org/events/sec09/tech/full_papers/reardon.pdf">Prior
1285)     research</a> has indicated that this may not be optimal, and instead the
1286)     role that TCP plays (congestion control and reliability) should be moved
1287)     into Tor itself. This would allow a number of desirable changes, such as
1288)     preventing errors on one circuit delaying another, and giving Tor control
1289)     and visibility of congestion control.</p>
1290)     <p>There are <a
1291)     href="http://www.cl.cam.ac.uk/~sjm217/papers/tor11datagramcomparison.pdf">many
1292)     ways to do this</a>, each with their own tradeoffs and difficulty of
1293)     implementation. This project will be to select one (or more) option and
1294)     implement it in Tor. The primary goal will be to test this modified version
1295)     of Tor in simulation, but if it turns out to work well, it could be
1296)     deployed in the live Tor network.</p>
1297)     <p>Excellent C programming skills are needed, and knowledge of Tor
1298)     internals are highly desirable.</p>
1299)     </li>

1300)     -->

1301)     

1302)     <!--

1303)     <a id="resistCensorship"></a>

1304)     <li>
1305)     <b>Improving Tor's ability to resist censorship</b>

1306)     <br>

1307)     Priority: <i>Medium to High</i>

1308)     <br>

1309)     Effort Level: <i>Medium to High</i>

1310)     <br>

1311)     Skill Level: <i>High</i>

1312)     <br>

1313)     Likely Mentors: <i>Jake, Thomas</i>

1314)     <p>The Tor 0.2.1.x series makes <a

1315)     href="<svnprojects>design-paper/blocking.html">significant
1316)     improvements</a> in resisting national and organizational censorship.
1317)     But Tor still needs better mechanisms for some parts of its

1318)     anti-censorship design.</p>
1319)     <p>One huge category of work is adding features to our <a

1320)     href="https://gitweb.torproject.org/bridgedb.git?a=tree">BridgeDB</a>

1321)     service (Python). Tor aims to give out <a href="<page docs/bridges>">bridge
1322)     relay addresses</a> to users that can't reach the Tor network
1323)     directly, but there's an arms race between algorithms for distributing
1324)     addresses and algorithms for gathering and blocking them. See <a

1325)     href="<blog>bridge-distribution-strategies">our

1326)     blog post on the topic</a> as an overview, and then look at <a

1327)     href="https://lists.torproject.org/pipermail/tor-dev/2009-December/000666.html">Roger's
1328)     or-dev post</a> from December 2009 for more recent thoughts &mdash; lots of

1329)     design work remains.</p>
1330)     <p>If you want to get more into the guts of Tor itself (C), a more minor problem

1331)     we should address is that current Tors can only listen on a single
1332)     address/port combination at a time. There's

1333)     <a href="<specblob>proposals/118-multiple-orports.txt">a

1334)     proposal to address this limitation</a> and allow clients to connect
1335)     to any given Tor on multiple addresses and ports, but it needs more

1336)     work.</p>
1337)     <p>This project could involve a lot of research and design. One of the big

1338)     challenges will be identifying and crafting approaches that can still
1339)     resist an adversary even after the adversary knows the design, and

1340)     then trading off censorship resistance with usability and
1341)     robustness.</p>

1342)     </li>

1343)     -->

1344)     

1345)     <!--

1346)     <a id="tailsHiddenServicePetnames"></a>
1347)     <li>
1348)     <b>Petname system for Tor hidden services</b>
1349)     <br>
1350)     Priority: <i>Medium</i>
1351)     <br>
1352)     Effort Level: <i>High</i>
1353)     <br>
1354)     Skill Level: <i>High</i>
1355)     <br>
1356)     Likely Mentors: <i>ague</i>
1357)     <p>Tor provides hidden services. These services are only reachable through
1358)     Tor itself, and provide greater anonymity both for the providers of the
1359)     service and for its users.</p>
1360)     <p>One current downside of Tor hidden services is that they are addressed
1361)     using 80-bit base32-encoded addresses such as "v2cbb2l4lsnpio4q.onion".
1362)     These addresses are hard to remember; this makes them hard to use
1363)     within amnesic environment like Tails.</p>
1364)     <p>The project is to implement a petname system for Tor hidden services:
1365)     a way for users or providers of Tor hidden services to add a simple
1366)     'nickname' to a central database. Users could then query this central
1367)     database to retrieve a full hidden service address by giving
1368)     a nickname.</p>
1369)     <p>Adding petnames to the database could be done using a web interface or
1370)     automated fetch like those described in the <a
1371)     href="https://gitweb.torproject.org/torspec.git/blob/HEAD:/proposals/ideas/xxx-onion-nyms.txt">&quot;.onion
1372)     nym system&quot; proposal</a>.</p>
1373)     <p>Querying the database could be done using a web interface, a REST API and
1374)     a DNS interface.</p>
1375)     <p>In order not to grow indefinitely, the software should make regular tests to
1376)     see if hidden services are still reachable and, depending on the last time
1377)     a nickname was accessed, cleanup the database as necessary.</p>
1378)     <p>The software should allow a distributed, fault-tolerant setup.
1379)     All nodes should have a synchronized copy of the database, should be
1380)     ready to answer queries and should coordinate the tests for hidden
1381)     service availability.</p>
1382)     <p>The resulting codebase must be easy to deploy: it should not be hard to
1383)     setup new databases.</p>
1384)     <p>It is expected that the volunteer will be using Behaviour Driven
1385)     Development methods. Either in Ruby using Cucumber and RSpec, or in
1386)     Python using similar tools.</p>
1387)     </li>

1388)     -->

1389)     

1390)     <!--

1391)     <a id="tailsServer"></a>
1392)     <li>
1393)     <b>Tails server: Self-hosted services behind Tails-powered Tor hidden services</b>
1394)     <br>
1395)     Priority: <i>Medium</i>
1396)     <br>
1397)     Effort Level: <i>High</i>
1398)     <br>
1399)     Skill Level: <i>Medium, but wide-scoped</i>
1400)     <br>
1401)     Likely Mentors: <i>intrigeri, anonym</i>
1402)     <p>Let's talk about group collaboration, communication and data sharing
1403)     infrastructure, such as chat servers, wikis, or file repositories.</p>
1404)     <p>Hosting such data and infrastructure <b>in the cloud</b> generally
1405)     implies to trust the service providers not to disclose content, usage or
1406)     users location information to third-parties. Hence, there are many threat
1407)     models in which cloud hosting is not suitable.</p>
1408)     <p>Tor partly answers the <b>users location</b> part; this is great, but
1409)     <b>content</b> is left unprotected.</p>
1410)     <p>There are two main ways to protect such content: either to encrypt it
1411)     client-side (<b>security by design</b>), or to avoid putting it into
1412)     untrusted hands in the first place.</p>
1413)     <p>Cloud solutions that offer security by design are rare and generally
1414)     not mature yet. The <b>Tails server</b> project is about exploring the
1415)     other side of the alternative: avoiding to put private data into
1416)     untrusted hands in the first place.</p>
1417)     <p>This is made possible thanks to Tor hidden services, that allow users
1418)     to offer location-hidden services, and make self-hosting possible in
1419)     many threat models. Self-hosting has its own lot of problems, however,
1420)     particularly in contexts where the physical security of the hosting
1421)     place is not assured. Combining Tor hidden services with Tails'
1422)     amnesia property and limited support for persistent encrypted data
1423)     allows to protect content, to a great degree, even in such contexts.</p>
1424)     <p>In short, setting up a new Tails server would be done by:</p>

1425)     

1426)     <ol style="list-style-type: decimal">
1427)       <li>Alice plugs a USB stick into a running desktop Tails system.</li>
1428)       <li>Alice uses a GUI to easily configure the needed services.</li>
1429)       <li>Alice unplugs the USB stick, that now contains encrypted services
1430)       configuration and data storage space.</li>
1431)       <li>Alice plugs that USB stick (and possibly a Tails Live CD) into the
1432)       old laptop that was dedicated to run Tails server.</li>
1433)       <li>Once booted, Alice enters the encryption passphrase either
1434)       directly using the keyboard or through a web interface listening on the
1435)       local network.</li>
1436)       <li>Then, Bob can use the configured services once he gets a hold on
1437)       the hidden service address. (The <b>petname system for Tor hidden
1438)       services</b> project would be very complementary to this one, by the
1439)       way.)</li>
1440)     </ol>

1441)     

1442)     <p>Tails server should content itself with hardware that is a bit old
1443)     (such as a PIII-450 laptop with 256MB of RAM) and/or half broken (e.g.
1444)     non-functional hard-disk, screen or keyboard).</p>
1445)     <p>The challenges behind this project are:</p>

1446)     

1447)     <ul>
1448)       <li>Design and write the services configuration GUI [keywords: edit
1449)       configuration files, upgrade between major Debian versions,
1450)       debconf].</li>
1451)       <li>How to create the hidden service key? [keywords: Vidalia, control
1452)       protocol].</li>
1453)       <li>Adapt the Tails boot process to allow switching to &quot;server
1454)       mode&quot; when appropriate.</li>
1455)       <li>Add support, to the Tails persistence setup process, for asking an
1456)       encryption passphrase without X, and possibly with a broken keyboard
1457)       and/or screen [keywords: local network, SSL/TLS?, certificate?].</li>
1458)     </ul>

1459)     

1460)     <p>This project can easily grow quite large, so the first task would
1461)     probably be to clarify what it would need to get an initial (minimal
1462)     but working) implementation ready to be shipped to users.</p>
1463)     <p>This project does not require to be an expert in one specific field,
1464)     but it requires to be experienced and at ease with a large scope of
1465)     software development tools, processes, and operating system knowledge.</p>
1466)     <p>Undertaking this project requires in-depth knowledge of Debian-like
1467)     systems (self-test: do the "dpkg conffile" and "debconf preseeding"
1468)     words sound new to your ear?); the Debian Live persistence system
1469)     being written in shell, being at ease with robust shell scripting is
1470)     a must; to end with, at least two pieces of software need to be
1471)     written from scratch (a GUI and a webapp): the preferred languages for
1472)     these tasks would be Python and Perl. Using Behaviour Driven
1473)     Development methods to convey expectations and acceptance criteria
1474)     would be most welcome.</p>
1475)     <p>For more information see https://tails.boum.org/todo/server_edition/</p>
1476)     </li>

1477)     -->

1478)     

1479)     <!--

1480)     <a id="geoIPUpgrade"></a>
1481)     <li>
1482)     <b>Improve our GeoIP file format</b>
1483)     <br>
1484)     Priority: <i>Medium</i>
1485)     <br>
1486)     Effort Level: <i>Medium</i>
1487)     <br>
1488)     Skill Level: <i>Medium to High</i>
1489)     <br>
1490)     Likely Mentors: <i>Robert Ransom</i>

1491)     <p>Currently, Tor bridges and relays read an entire IP-&gt;country database

1492)     into memory from a text file during startup.  We would like to
1493)     distribute this database and store it on disk in a much more compact

1494)     form, and perform IP->country lookups on it in its on-disk format if

1495)     possible.</p>

1496)     <p>We have <a href='https://trac.torproject.org/projects/tor/ticket/2506'>a
1497)     sketch of a design</a> for a moderately optimized format for IPv4 GeoIP
1498)     data; this project will involve both implementing the IPv4 format and
1499)     designing and implementing a format for IPv6 GeoIP data.</p>

1500)     <p>Since the core of this project is researching IPv6 GeoIP data and

1501)     designing the IPv6 format, this is not likely to be a good GSoC

1502)     project.</p>

1503)     </li>

1504)     -->

1505)     

1506)     <!--

1507)     <a id="armClientMode"></a>

1508)     <li>
1509)     <b>Client Mode Use Cases for Arm</b>
1510)     <br>
1511)     Priority: <i>Medium</i>
1512)     <br>
1513)     Effort Level: <i>High</i>
1514)     <br>
1515)     Skill Level: <i>Medium</i>
1516)     <br>

1517)     Likely Mentors: <i>Damian (atagar)</i>

1518)     <p><a href="<page projects/arm>">Arm</a> is a Tor command line status
1519)     monitor on *nix environments (Linux, Mac, and BSD). It functions much like
1520)     top does, giving a CLI overlay of Tor's bandwidth usage, connections,
1521)     configuration, log, etc. Thus far its design has been geared for Tor relay
1522)     operators. However, this doesn't need to be the case. This project would be
1523)     to expand and simplify arm to make it useful for Tor's client users
1524)     too.</p>

1525)     

1526)     <p>This would include UI design, experimenting, and a lot of python
1527)     hacking. Here's some ideas for client functionality arm could provide:</p>

1528)     

1529)     <ul>
1530)       <li>A panel for client connections, showing each hop of the user's
1531)       circuits with the ISP, country, and jurisdiction where those relays
1532)       reside. Other interesting information would be the circuit's latency, how
1533)       long its been around, and its possible exit ports. Some of this will be
1534)       pretty tricky and require some experimentation to figure out what
1535)       information can be fetched safely (for instance, scraping rdns and whois
1536)       lookups could give hints about a relay's ISP, but we'd need to do it on
1537)       all Tor relays to avoid leaking our connections to the resolver).</li>

1538)       

1539)       <li>Options to let the user request new circuits (the &quot;New
1540)       Identity&quot; feature in Vidalia), select the exit country, etc.</li>

1541)       

1542)       <li>A panel showing Internet application and if their connections are
1543)       being routed through Tor or not (giving a warning if there's leaks).</li>

1544)       

1545)       <li>The status of the bridges we're configured to use (ie, are they up?).
1546)       This would include adding control port functionality to Tor for <a
1547)       href="https://trac.torproject.org/projects/tor/ticket/2068">ticket
1548)       2068</a>.</li>

1549)       

1550)       <li>A one click option to set Tor to be a client, relay, or bridge. The
1551)       goal would be to make it trivial for users to voluntarily contribute to
1552)       the Tor network.</li>

1553)       

1554)       <li>Menus as an alternative to hotkeys to make the interface more
1555)       intuitive and usable for beginners (<a
1556)       href="http://gnosis.cx/publish/programming/charming_python_6.html">example</a>).</li>

1557)       

1558)       <li>Look at Vidalia and TorK for ideas and solicit input from the Tor community.</li>
1559)     </ul>

1560)     

1561)     <p>

1562)     More information is available in the following sections of arm's dev notes: <a href="https://trac.torproject.org/projects/tor/wiki/doc/arm#ConnectionListingExpansion">Connection Listing Expansion</a>, <a href="https://trac.torproject.org/projects/tor/wiki/doc/arm#CircuitDetails">Circuit Details</a>, and <a href="https://trac.torproject.org/projects/tor/wiki/doc/arm#ClientModeUseCases">Client Mode Use Cases</a>

1563)     </p>

1564)     </li>

1565)     -->

1566)     

1567)     <!--

1568)     <a id="vidalia-hidden-service-panel"></a>
1569)     <li>
1570)     <b>Torrc plugin and improved hidden service configuration panel</b>
1571)     <br>
1572)     Priority: <i>Medium</i>
1573)     <br>
1574)     Effort Level: <i>Medium</i>
1575)     <br>
1576)     Skill Level: <i>Medium</i>
1577)     <br>
1578)     Likely Mentors: <i>Tomás</i>
1579)     <p>Vidalia's configuration handling has changed in the alpha branch. Now
1580)     every Tor option is saved in the torrc file. With that change, the
1581)     Hidden Service configuration panel was removed due to its specificity
1582)     and its multiple bugs.</p>

1583)     

1584)     <p>The idea would be to provide the new Torrc class' functionality to the
1585)     Plugin Engine and with that, create a better Hidden Service
1586)     configuration panel as a plugin.</p>

1587)     

1588)     <p>A person undertaking this project should have good UI design, layout
1589)     skills and some C++ development experience. Previous experience with Qt
1590)     and Qt's Designer will be very helpful, but are not required. Javascript
1591)     knowledge is a plus, but it shouldn't be a problem if the person
1592)     complies with the previous requirements.</p>
1593)     </li>

1594)     -->

1595)     

1596)     <a id="metricsSearch"></a>
1597)     <li>
1598)     <b>Searchable Tor descriptor and Metrics data archive</b>
1599)     <br>
1600)     Priority: <i>Medium</i>
1601)     <br>
1602)     Effort Level: <i>Medium</i>
1603)     <br>
1604)     Skill Level: <i>Medium</i>
1605)     <br>
1606)     Likely Mentors: <i>Karsten</i>

1607)     <p>The <a href="https://metrics.torproject.org/data.html">Metrics data archive</a> of Tor relay descriptors and other Tor-related network data has grown to over 100G in size, bz2-compressed.  We have developed two search interfaces: the <a href="https://metrics.torproject.org/relay-search.html">relay search</a> finds relays by nickname, fingerprint, or IP address in a given month; <a href="https://metrics.torproject.org/exonerator.html">ExoneraTor</a> finds whether a given IP address was a relay on a given day.</p>

1608)     

1609)     <p>We'd like to have a more general search application for Tor descriptors and metrics data.  There are more <a href="https://metrics.torproject.org/formats.html">descriptor types</a> that we'd like to include in the search.  The search application should handle most of them and understand some semantics like what's a timestamp, what's an IP address, and what's a link to another descriptor.  Users should then be able to search for arbitrary strings or limit their search to given time periods or IP address ranges.  Descriptors that reference other descriptors should contain links, and descriptors should be able to say from where they are linked.  The goal is to make the archive easily browsable.</p>

1610)     

1611)     <p>The search application shall be separate from the metrics website and shouldn't rely on the metrics website codebase.  The search application will contain hourly updated descriptor data from the metrics website via rsync.  Programming language and database system are not specified yet, though there's a slight preference for Python/Django and Postgres for maintenance reasons.  If there are good reasons to pick something else, e.g, some NoSQL variant or some search application framework, that's fine, too.  Further requirements are that lookups should be really fast and that changes to the search application can be implemented in reasonable time.</p>

1612)     

1613)     <p>Applications for this project should come with a design of the proposed search application, ideally with a proof-of-concept based on a subset of the available data to show that it will be able to handle the 100G+ of data.</p>

1614)     

1615)     <!--

1616)     <a id="unitTesting"></a>

1617)     <li>
1618)     <b>Improve our unit testing process</b>

1619)     <br>

1620)     Priority: <i>Medium</i>

1621)     <br>

1622)     Effort Level: <i>Medium</i>

1623)     <br>

1624)     Skill Level: <i>Medium</i>

1625)     <br>

1626)     Likely Mentors: <i>Nick, Erinn</i>

1627)     <p>Tor needs to be tested far more thoroughly. This is a
1628)     multi-part effort. To start with, our unit test coverage should
1629)     rise substantially, especially in the areas outside the utility
1630)     functions. This will require significant refactoring of some parts
1631)     of Tor, in order to dissociate as much logic as possible from
1632)     globals.</p>

1633)     <p>Additionally, we need to automate our performance testing. We've got

1634)     buildbot to automate our regular integration and compile testing already
1635)     (though we need somebody to set it up on Windows),
1636)     but we need to get our network simulation tests (as built in <a
1637)     href="https://svn.torproject.org/svn/torflow/trunk/README">TorFlow</a>)
1638)     updated for more recent versions of Tor, and designed to launch a test
1639)     network either on a single machine, or across several, so we can test

1640)     changes in performance on machines in different roles automatically.</p>

1641)     </li>

1642)     -->

1643)     

1644)     <!--

1645)     <a id="simulateSlowConnections"></a>

1646)     <li>
1647)     <b>Simulator for slow Internet connections</b>

1648)     <br>

1649)     Priority: <i>Medium</i>

1650)     <br>

1651)     Effort Level: <i>Medium</i>

1652)     <br>

1653)     Skill Level: <i>Medium</i>

1654)     <br>

1655)     Likely Mentors: <i>Nick</i>

1656)     <p>

1657)     Many users of Tor have poor-quality Internet connections, giving low
1658)     bandwidth, high latency, and high packet loss/re-ordering. User
1659)     experience is that Tor reacts badly to these conditions, but it is
1660)     difficult to improve the situation without being able to repeat the
1661)     problems in the lab.

1662)     </p>

1663)     

1664)     <p>

1665)     This project would be to build a simulation environment which
1666)     replicates the poor connectivity so that the effect on Tor performance
1667)     can be measured. Other components would be a testing utility to
1668)     establish what are the properties of connections available, and to
1669)     measure the effect of performance-improving modifications to Tor.

1670)     </p>

1671)     

1672)     <p>

1673)     The tools used would be up to the student, but dummynet (for FreeBSD)
1674)     and nistnet (for Linux) are two potential components on which this
1675)     project could be built. Students should be experienced with network
1676)     programming/debugging and TCP/IP, and preferably familiar with C and a
1677)     scripting language.

1678)     </p>

1679)     </li>

1680)     -->

1681)     

1682)     <!--

1683)     <a id="usabilityTesting"></a>

1684)     <li>
1685)     <b>Usability testing of Tor</b>

1686)     <br>

1687)     Priority: <i>Medium</i>

1688)     <br>

1689)     Effort Level: <i>Medium</i>

1690)     <br>

1691)     Skill Level: <i>Low to Medium</i>

1692)     <br>

1693)     Likely Mentors: <i>Andrew</i>

1694)     <p>

1695)     Especially the browser bundle, ideally amongst our target demographic.
1696)     That would help a lot in knowing what needs to be done in terms of bug
1697)     fixes or new features. We get this informally at the moment, but a more
1698)     structured process would be better.

1699)     </p>

1700)     

1701)     <p>
1702)     Please note that since this isn't a coding project, it isn't suitable for
1703)     Google Summer of Code.
1704)     </p>

1705)     </li>

1706)     -->

1707)     

1708)     <!--

1709)     <a id="torsocksForOSX"></a>

1710)     <li>
1711)     <b>Make torsocks/dsocks work on OS X</b>

1712)     <br>

1713)     Priority: <i>Medium</i>

1714)     <br>

1715)     Effort Level: <i>Medium</i>

1716)     <br>

1717)     Skill Level: <i>Medium</i>

1718)     <br>

1719)     Likely Mentors: <i>Robert Hogan</i>

1720)     <p>

1721)     <a href="https://code.google.com/p/torsocks/">Torsocks</a> and <a
1722)     href="https://code.google.com/p/dsocks/">dsocks</a> are wrappers that will

1723)     run applications, intercept their outgoing network connections, and push
1724)     those connections through Tor. The goal is to handle applications that
1725)     don't support proxies (or don't supporting them well). To get it right,
1726)     they need to intercept many system calls. The syscalls you need to
1727)     intercept on Linux differ dramatically from those on BSD. So Torsocks
1728)     works fine on Linux, dsocks works ok on BSD (though it may be less
1729)     maintained and thus might miss more syscalls), and nothing works well
1730)     on both. First, we should patch dsocks to use Tor's <i>mapaddress</i>
1731)     commands from the controller interface, so we don't waste a whole
1732)     round-trip inside Tor doing the resolve before connecting. Second,
1733)     we should make our <i>torify</i> script detect which of torsocks or
1734)     dsocks is installed, and call them appropriately. This probably means
1735)     unifying their interfaces, and might involve sharing code between them
1736)     or discarding one entirely.

1737)     </p>
1738)     </li>

1739)     -->

1740)     

1741)     <!--

1742)     <a id="vidaliaStatusEventInterface"></a>

1743)     <li>
1744)     <b>Tor Controller Status Event Interface for Vidalia</b>
1745)     <br>
1746)     Priority: <i>Medium</i>
1747)     <br>
1748)     Effort Level: <i>Medium</i>
1749)     <br>
1750)     Skill Level: <i>Low to Medium</i>
1751)     <br>

1752)     Likely Mentors: <i>Tomás</i>

1753)     <p>There are a number of status changes inside Tor of which the user may need
1754)     to be informed. For example, if the user is trying to set up his Tor as a
1755)     relay and Tor decides that its ports are not reachable from outside
1756)     the user's network, we should alert the user. Currently, all the user
1757)     gets is a couple of log messages in Vidalia's 'message log' window, which they
1758)     likely never see since they don't receive a notification that something
1759)     has gone wrong. Even if the user does actually look at the message log,
1760)     most of the messages make little sense to the novice user.</p>
1761)     <p>Tor has the ability to inform Vidalia of many such status
1762)     changes, and we recently implemented support for a couple of these
1763)     events. Still, there are many more status events which the user should
1764)     be informed of, and we need a better UI for actually displaying them
1765)     to the user.</p>
1766)     <p>The goal of this project then is to design and implement a UI for
1767)     displaying Tor status events to the user. For example, we might put a
1768)     little badge on Vidalia's tray icon that alerts the user to new status
1769)     events they should look at. Double-clicking the icon could bring up a
1770)     dialog that summarizes recent status events in simple terms and maybe
1771)     suggests a remedy for any negative events if they can be corrected by
1772)     the user. Of course, this is just an example and one is free to
1773)     suggest another approach.</p>
1774)     <p>A person undertaking this project should have good UI design and layout
1775)     skills and some C++ development experience. Previous experience with Qt and
1776)     Qt's Designer will be very helpful, but are not required. Some
1777)     English writing ability will also be useful, since this project will
1778)     likely involve writing small amounts of help documentation that should
1779)     be understandable by non-technical users. Bonus points for some graphic
1780)     design/Photoshop fu, since we might want/need some shiny new icons too.</p>
1781)     </li>

1782)     -->

1783)     

1784)     <!--

1785)     <a id="orbot-optimisation"></a>
1786)     <li>
1787)     <b>Core Tor mobile optimisation</b>
1788)     <br>
1789)     Priority: <i>Medium</i>
1790)     <br>
1791)     Effort Level: <i>Medium</i>
1792)     <br>
1793)     Skill Level: <i>High</i>
1794)     <br>

1795)     Likely Mentors: <i>Jake</i>

1796)     <p>
1797)     The existing port of Tor to Android is basically a straight
1798)     cross-compile to Linux ARM. There has been no work done in looking at
1799)     possible optimizations of Tor within a mobile hardware environment or on
1800)     mobile networks. In addition, a number of additional Android OS APIs are
1801)     available (such as wireless network status) that could be taken
1802)     advantage of.
1803)     </p>

1804)     

1805)     <p>
1806)     It should be noted, that even without optimisation, Tor is handling the
1807)     mobile network environment very well, automatically detecting change in
1808)     IP addresses, opening circuits, etc, as the device switches from no
1809)     coverage to 2G, 3G or Wifi constantly as it changes position. However,
1810)     this observation of &quot;very well&quot;, is just based on user
1811)     experience, and not any detailed study of what exactly is happening, and
1812)     what threats might exist because of this constantly changing network state.
1813)     </p>

1814)     

1815)     <p>
1816)     Finally, the build process needs to be moved to the Android NDK from the
1817)     custom GCC toolchain we are now using, and compatibility with Android
1818)     2.3 and 3.x Honeycomb OS need to be verified.
1819)     </p>

1820)     

1821)     <p>
1822)     For more information see the <a
1823)     href="https://svn.torproject.org/svn/projects/android/trunk/Orbot/BUILD">Orbot
1824)     build documentation</a>.
1825)     </p>
1826)     </li>

1827)     -->

1828)     

1829)     <!--

1830)     <a id="orbot-orlibAndOutreach"></a>
1831)     <li>
1832)     <b>Orbot integration library and community outreach</b>
1833)     <br>
1834)     Priority: <i>Medium</i>
1835)     <br>
1836)     Effort Level: <i>Low</i>
1837)     <br>
1838)     Skill Level: <i>Medium</i>
1839)     <br>
1840)     Likely Mentors: <i>Nathan (n8fr8)</i>
1841)     <p>
1842)     We need additional work on <a
1843)     href="https://github.com/guardianproject/orlib">ORLib</a>, our library for
1844)     use with third-party application to easily enable them to support
1845)     &quot;Torification&quot; on non-rooted devices (i.e. w/o transparent
1846)     proxying). This library includes a SOCKS client, a wrapper for the Apache
1847)     HTTPClient library, a utility class for detecting the state of Orbot
1848)     connectivity, and other relevant/useful things an Android app might need to
1849)     anonymize itself. This work would includes direct development of the
1850)     library, documentation, and sample code. Outreach or effort to implement
1851)     the library within other open-source apps is also needed.
1852)     </p>
1853)     </li>

1854)     -->

1855)     

1856)     <!--

1857)     <a id="vidaliaNetworkMap"></a>

1858)     <li>
1859)     <b>An Improved and More Usable Network Map in Vidalia</b>
1860)     <br>
1861)     Priority: <i>Low to Medium</i>
1862)     <br>
1863)     Effort Level: <i>Medium</i>
1864)     <br>
1865)     Skill Level: <i>Medium</i>
1866)     <br>

1867)     Likely Mentors: <i>Tomás</i>

1868)     <p>
1869)     One of Vidalia's existing features is a network map that shows the user
1870)     the approximate geographic location of relays in the Tor network and
1871)     plots the paths the user's traffic takes as it is tunneled through the
1872)     Tor network. The map is currently not very interactive and has rather
1873)     poor graphics. Instead, we implemented KDE's Marble widget such
1874)     that it gives us a better quality map and enables improved interactivity,
1875)     such as allowing the user to click on individual relays or circuits to
1876)     display additional information. We want to add the ability
1877)     for users to click on a particular relay or a country containing one or
1878)     more Tor exit relays and say, "I want my connections to exit
1879)     from here."
1880)     </p>

1881)     

1882)     <p>
1883)     This project will first involve getting familiar with Vidalia
1884)     and the Marble widget's API. One will then integrate the widget
1885)     into Vidalia and customize Marble to be better suited for our application,
1886)     such as making circuits clickable, storing cached map data in Vidalia's
1887)     own data directory, and customizing some of the widget's dialogs.
1888)     </p>

1889)     

1890)     <p>
1891)     A person undertaking this project should have good C++ development
1892)     experience. Previous experience with Qt and CMake is helpful, but not
1893)     required.
1894)     </p>

1895)     </li>

1896)     -->

1897)     

1898)     <!--

1899)     <a id="obfsproxy-fuzzer"></a>
1900)     <li>
1901)     <b>Fuzzer for the Tor protocol</b>
1902)     <br>
1903)     Priority: <i>Low to Medium</i>
1904)     <br>
1905)     Effort Level: <i>Medium to High</i>
1906)     <br>
1907)     Skill Level: <i>High</i>
1908)     <br>
1909)     Likely Mentors: <i>asn</i>
1910)     <p>Involves researching good and smart ways to fuzz stateful network
1911)     protocols, and also implementing the fuzzer.</p>

1912)     

1913)     <p>We are mostly looking for a fuzzer that fuzzes the Tor protocol
1914)     itself, and not the Tor directory protocol.</p>

1915)     

1916)     <p>Bonus points if it's extremely modular. Relevant research:</p>

1917)     

1918)     <ul>
1919)       <li>PROTOS - Security Testing of Protocol Implementations</li>
1920)       <li>INTERSTATE: A Stateful Protocol Fuzzer for SIP</li>
1921)       <li>Detecting Communication Protocol Security Flaws by Formal Fuzz
1922)       Testing and Machine Learning</li>
1923)       <li>SNOOZE: Toward a Stateful NetwOrk prOtocol fuzZE</li>
1924)       <li>Michal Zalewski's &quot;bugger&quot;</li>
1925)       <li>Also look at the concepts of &quot;model checking&quot; and
1926)       &quot;symbolic execution&quot; to get inspired.</li>
1927)     </ul>
1928)     </li>

1929)     -->

1930)     

1931)     <!--

1932)     <a id="armGui"></a>
1933)     <li>
1934)     <b>GUI for Arm</b>
1935)     <br>
1936)     Priority: <i>Low</i>
1937)     <br>
1938)     Effort Level: <i>High</i>
1939)     <br>
1940)     Skill Level: <i>Medium</i>
1941)     <br>

1942)     Likely Mentors: <i>Damian (atagar)</i>

1943)     <p>
1944)     Arm has several unique features, some of the most interesting being its
1945)     connection listing (correlating netstat results against the Tor consensus)
1946)     and configuration editor (a quick method for editing Tor's config, with
1947)     information pulled from the control port and man page). However, since arm
1948)     is a command line controller it's of limited appeal to certain sets of
1949)     users. This project would be to build a GTK or Qt frontend for the
1950)     controller, providing similar features set but with a windowed interface.
1951)     </p>

1952)     

1953)     <p>
1954)     The vast majority of arm's more interesting functionality lies in its

1955)     backend <a href="https://gitweb.torproject.org/arm.git/tree/HEAD:/src/util">utilities</a>, so

1956)     there should be little to no work decoupling the CLI from its backend.
1957)     Instead, this project would mostly be UI hacking and experimentation,
1958)     trying different interfaces to find something that's elegant and simple,
1959)     but matches the information found in the current terminal application.
1960)     </p>
1961)     </li>

1962)     -->

1963)     

1964)     <!--

1965)     <a id="APAF"></a>
1966)     <li>
1967)     <b>APAF: Anonymous Python Application Framework</b>
1968)     <br>
1969)     Priority: <i>Medium</i>
1970)     <br>
1971)     Effort Level: <i>Medium</i>
1972)     <br>
1973)     Skill Level: <i>Medium</i>
1974)     <br>
1975)     Likely Mentors: <i>Arturo (hellais)</i>
1976)     <p>

1977)     The goal of APAF is to create a build framework for creating a binary
1978)     package for multiple platforms (.app/dmg, .exe, .deb, etc.) that includes
1979)     the python interpreter (cpython), the Tor binary and all the UI necessary
1980)     to make users be able to easily run the bundled Tor Hidden Service.

1981)     </p>

1982)     

1983)     <p>

1984)     For GSoC the student is expected to create the build system capable of
1985)     building a simple web application that serves static files. It should also
1986)     include a web UI for a wizard setup, checking the status of the HS and
1987)     configuring it.

1988)     </p>

1989)     

1990)     <p>

1991)     For more details on this: check out <a
1992)     href="https://pad.riseup.net/p/1zA8FI4nrYlq">https://pad.riseup.net/p/1zA8FI4nrYlq</a>

1993)     </p>
1994)     </li>

1995)     -->

1996)     

1997)     <li>
1998)     <b>Bring up new ideas!</b>

1999)     <br>

2000)     Don't like any of these? Look at the <a

2001)     href="/press/presskit/2008-12-19-roadmap-full.pdf">Tor development

2002)     roadmap</a> for more ideas, or just try out Tor, Vidalia, and Torbutton,
2003)     and find out what you think needs fixing.

2004)     Some of the <a href="<spectree>proposals">current proposals</a>

2005)     might also be short on developers.
2006)     </li>

2007)     

2008)     </ol>

2009)     

2010)     <a id="OtherCoding"></a>
2011)     <h2><a class="anchor" href="#OtherCoding">Other Coding and Design related ideas</a></h2>
2012)     <ol>
2013)     <li>Tor relays don't work well on Windows XP. On
2014)     Windows, Tor uses the standard <tt>select()</tt> system
2015)     call, which uses space in the non-page pool. This means
2016)     that a medium sized Tor relay will empty the non-page pool, <a

2017)     href="<wiki>doc/WindowsBufferProblems">causing

2018)     havoc and system crashes</a>. We should probably be using overlapped IO
2019)     instead. One solution would be to teach <a
2020)     href="http://www.monkey.org/~provos/libevent/">libevent</a> how to use
2021)     overlapped IO rather than select() on Windows, and then adapt Tor to
2022)     the new libevent interface. Christian King made a
2023)     <a href="https://svn.torproject.org/svn/libevent-urz/trunk/">good
2024)     start</a> on this in the summer of 2007.</li>

2025)     

2026)     <li>We need to actually start building our <a href="<page
2027)     docs/documentation>#DesignDoc">blocking-resistance design</a>. This involves
2028)     fleshing out the design, modifying many different pieces of Tor, adapting
2029)     <a href="<page projects/vidalia>">Vidalia</a> so it supports the
2030)     new features, and planning for deployment.</li>

2031)     

2032)     <li>We need a flexible simulator framework for studying end-to-end
2033)     traffic confirmation attacks. Many researchers have whipped up ad hoc
2034)     simulators to support their intuition either that the attacks work
2035)     really well or that some defense works great. Can we build a simulator
2036)     that's clearly documented and open enough that everybody knows it's
2037)     giving a reasonable answer? This will spur a lot of new research.
2038)     See the entry <a href="#Research">below</a> on confirmation attacks for
2039)     details on the research side of this task &mdash; who knows, when it's
2040)     done maybe you can help write a paper or three also.</li>

2041)     

2042)     <li>Tor 0.1.1.x and later include support for hardware crypto
2043)     accelerators via OpenSSL. It has been lightly tested and is
2044)     possibly very buggy.  We're looking for more rigorous testing,

2045)     performance analysis, and optimally, code fixes to OpenSSL and

2046)     Tor if needed.</li>

2047)     

2048)     <li>Perform a security analysis of Tor with <a

2049)     href="https://secure.wikimedia.org/wikipedia/en/wiki/Fuzz_testing">"fuzz"</a>. Determine

2050)     if there are good fuzzing libraries out there for what we want. Win fame by
2051)     getting credit when we put out a new release because of you!</li>

2052)     

2053)     <li>Tor uses TCP for transport and TLS for link
2054)     encryption. This is nice and simple, but it means all cells
2055)     on a link are delayed when a single packet gets dropped, and
2056)     it means we can only reasonably support TCP streams. We have a <a

2057)     href="<page docs/faq>#TransportIPnotTCP">list

2058)     of reasons why we haven't shifted to UDP transport</a>, but it would
2059)     be great to see that list get shorter. We also have a proposed <a

2060)     href="<specblob>proposals/100-tor-spec-udp.txt">specification

2061)     for Tor and
2062)     UDP</a> &mdash; please let us know what's wrong with it.</li>

2063)     

2064)     <li>We're not that far from having IPv6 support for destination addresses
2065)     (at exit nodes). If you care strongly about IPv6, that's probably the
2066)     first place to start.</li>

2067)     

2068)     <li>We need a way to generate the website diagrams (for example, the "How
2069)     Tor Works" pictures on the <a href="<page about/overview>">overview page</a>
2070)     from source, so we can translate them as UTF-8 text rather than edit
2071)     them by hand with Gimp. We might want to
2072)     integrate this as an wml file so translations are easy and images are
2073)     generated in multiple languages whenever we build the website.</li>

2074)     

2075)     <li>How can we make the various LiveCD/USB systems easier
2076)     to maintain, improve, and document?  One example is <a

2077)     href="https://tails.boum.org/">The Amnesic Incognito Live

2078)     System</a>.
2079)     </li>

2080)     

2081)     <li>
2082)     Another anti-censorship project is to try to make Tor
2083)     more scanning-resistant.  Right now, an adversary can identify <a

2084)     href="<specblob>proposals/125-bridges.txt">Tor bridges</a>

2085)     just by trying to connect to them, following the Tor protocol,
2086)     and seeing if they respond.  To solve this, bridges could <a
2087)     href="<svnprojects>design-paper/blocking.html#tth_sEc9.3">act like
2088)     webservers</a> (HTTP or HTTPS) when contacted by port-scanning tools,
2089)     and not act like bridges until the user provides a bridge-specific key.
2090)     To start, check out Shane Pope's <a
2091)     href="http://dl.dropbox.com/u/37735/index.html">thesis and prototype</a>.
2092)     </li>

2093)     

2094)     </ol>

2095)     

2096)     <a id="Research"></a>
2097)     <h2><a class="anchor" href="#Research">Research</a></h2>
2098)     <ol>
2099)     <li>The "end-to-end traffic confirmation attack":
2100)     by watching traffic at Alice and at Bob, we can <a
2101)     href="http://freehaven.net/anonbib/#danezis:pet2004">compare
2102)     traffic signatures and become convinced that we're watching the same
2103)     stream</a>. So far Tor accepts this as a fact of life and assumes this
2104)     attack is trivial in all cases. First of all, is that actually true? How
2105)     much traffic of what sort of distribution is needed before the adversary
2106)     is confident he has won? Are there scenarios (e.g. not transmitting much)
2107)     that slow down the attack? Do some traffic padding or traffic shaping
2108)     schemes work better than others?</li>
2109)     <li>A related question is: Does running a relay/bridge provide additional
2110)     protection against these timing attacks? Can an external adversary that can't
2111)     see inside TLS links still recognize individual streams reliably?
2112)     Does the amount of traffic carried degrade this ability any? What if the
2113)     client-relay deliberately delayed upstream relayed traffic to create a queue
2114)     that could be used to mimic timings of client downstream traffic to make it
2115)     look like it was also relayed? This same queue could also be used for masking
2116)     timings in client upstream traffic with the techniques from <a
2117)     href="http://www.freehaven.net/anonbib/#ShWa-Timing06">adaptive padding</a>,
2118)     but without the need for additional traffic. Would such an interleaving of
2119)     client upstream traffic obscure timings for external adversaries? Would the
2120)     strategies need to be adjusted for asymmetric links? For example, on
2121)     asymmetric links, is it actually possible to differentiate client traffic from
2122)     natural bursts due to their asymmetric capacity? Or is it easier than
2123)     symmetric links for some other reason?</li>
2124)     <li>Repeat Murdoch and Danezis's <a
2125)     href="http://www.cl.cam.ac.uk/~sjm217/projects/anon/#torta">attack from
2126)     Oakland 05</a> on the current Tor network. See if you can learn why it
2127)     works well on some nodes and not well on others. (My theory is that the
2128)     fast nodes with spare capacity resist the attack better.) If that's true,
2129)     then experiment with the RelayBandwidthRate and RelayBandwidthBurst
2130)     options to run a relay that is used as a client while relaying the
2131)     attacker's traffic: as we crank down the RelayBandwidthRate, does the
2132)     attack get harder? What's the right ratio of RelayBandwidthRate to
2133)     actually capacity? Or is it a ratio at all? While we're at it, does a
2134)     much larger set of candidate relays increase the false positive rate
2135)     or other complexity for the attack? (The Tor network is now almost two
2136)     orders of magnitude larger than it was when they wrote their paper.) Be
2137)     sure to read <a href="http://freehaven.net/anonbib/#clog-the-queue">Don't
2138)     Clog the Queue</a> too.</li>
2139)     <li>The "routing zones attack": most of the literature thinks of
2140)     the network path between Alice and her entry node (and between the
2141)     exit node and Bob) as a single link on some graph. In practice,
2142)     though, the path traverses many autonomous systems (ASes), and <a
2143)     href="http://freehaven.net/anonbib/#feamster:wpes2004">it's not uncommon
2144)     that the same AS appears on both the entry path and the exit path</a>.
2145)     Unfortunately, to accurately predict whether a given Alice, entry,
2146)     exit, Bob quad will be dangerous, we need to download an entire Internet
2147)     routing zone and perform expensive operations on it. Are there practical
2148)     approximations, such as avoiding IP addresses in the same /8 network?</li>
2149)     <li>Other research questions regarding geographic diversity consider
2150)     the tradeoff between choosing an efficient circuit and choosing a random
2151)     circuit. Look at Stephen Rollyson's <a
2152)     href="http://swiki.cc.gatech.edu:8080/ugResearch/uploads/7/ImprovingTor.pdf">position
2153)     paper</a> on how to discard particularly slow choices without hurting
2154)     anonymity "too much". This line of reasoning needs more work and more
2155)     thinking, but it looks very promising.</li>
2156)     <li>Tor doesn't work very well when relays have asymmetric bandwidth
2157)     (e.g. cable or DSL). Because Tor has separate TCP connections between
2158)     each hop, if the incoming bytes are arriving just fine and the outgoing
2159)     bytes are all getting dropped on the floor, the TCP push-back mechanisms
2160)     don't really transmit this information back to the incoming streams.
2161)     Perhaps Tor should detect when it's dropping a lot of outgoing packets,
2162)     and rate-limit incoming streams to regulate this itself? I can imagine
2163)     a build-up and drop-off scheme where we pick a conservative rate-limit,
2164)     slowly increase it until we get lost packets, back off, repeat. We
2165)     need somebody who's good with networks to simulate this and help design
2166)     solutions; and/or we need to understand the extent of the performance
2167)     degradation, and use this as motivation to reconsider UDP transport.</li>
2168)     <li>A related topic is congestion control. Is our
2169)     current design sufficient once we have heavy use? Maybe
2170)     we should experiment with variable-sized windows rather
2171)     than fixed-size windows? That seemed to go well in an <a

2172)     href="http://www.psc.edu/index.php/hpn-ssh/638">ssh

2173)     throughput experiment</a>. We'll need to measure and tweak, and maybe
2174)     overhaul if the results are good.</li>
2175)     <li>Our censorship-resistance goals include preventing
2176)     an attacker who's looking at Tor traffic on the wire from <a
2177)     href="<svnprojects>design-paper/blocking.html#sec:network-fingerprint">distinguishing
2178)     it from normal SSL traffic</a>. Obviously we can't achieve perfect
2179)     steganography and still remain usable, but for a first step we'd like to
2180)     block any attacks that can win by observing only a few packets. One of
2181)     the remaining attacks we haven't examined much is that Tor cells are 512
2182)     bytes, so the traffic on the wire may well be a multiple of 512 bytes.
2183)     How much does the batching and overhead in TLS records blur this on the
2184)     wire? Do different buffer flushing strategies in Tor affect this? Could
2185)     a bit of padding help a lot, or is this an attack we must accept?</li>
2186)     <li>Tor circuits are built one hop at a time, so in theory we have the
2187)     ability to make some streams exit from the second hop, some from the
2188)     third, and so on. This seems nice because it breaks up the set of exiting
2189)     streams that a given relay can see. But if we want each stream to be safe,
2190)     the "shortest" path should be at least 3 hops long by our current logic, so
2191)     the rest will be even longer. We need to examine this performance / security
2192)     tradeoff.</li>
2193)     <li>It's not that hard to DoS Tor relays or directory authorities. Are client
2194)     puzzles the right answer? What other practical approaches are there? Bonus
2195)     if they're backward-compatible with the current Tor protocol.</li>
2196)     <li>Programs like <a

2197)     href="<page torbutton/index>">Torbutton</a> aim to hide

2198)     your browser's UserAgent string by replacing it with a uniform answer for
2199)     every Tor user. That way the attacker can't splinter Tor's anonymity set
2200)     by looking at that header. It tries to pick a string that is commonly used
2201)     by non-Tor users too, so it doesn't stand out. Question one: how badly
2202)     do we hurt ourselves by periodically updating the version of Firefox
2203)     that Torbutton claims to be? If we update it too often, we splinter the
2204)     anonymity sets ourselves. If we don't update it often enough, then all the
2205)     Tor users stand out because they claim to be running a quite old version
2206)     of Firefox. The answer here probably depends on the Firefox versions seen
2207)     in the wild. Question two: periodically people ask us to cycle through N
2208)     UserAgent strings rather than stick with one. Does this approach help,
2209)     hurt, or not matter? Consider: cookies and recognizing Torbutton users
2210)     by their rotating UserAgents; malicious websites who only attack certain
2211)     browsers; and whether the answers to question one impact this answer.
2212)     </li>
2213)     <li>How many bridge relays do you need to know to maintain
2214)     reachability? We should measure the churn in our bridges. If there is
2215)     lots of churn, are there ways to keep bridge users more likely to stay
2216)     connected?
2217)     </li>
2218)     </ol>

2219)     

2220)     <p>
2221)     <a href="<page about/contact>">Let us know</a> if you've made progress on any
2222)     of these!
2223)     </p>
2224)   </div>
2225)   <!-- END MAINCOL -->
2226)   <div id = "sidecol">
2227) #include "side.wmi"
2228) #include "info.wmi"
2229)   </div>
2230)   <!-- END SIDECOL -->
2231) </div>
2232) <!-- END CONTENT -->