Beware of the Flash and other third-party plugins to your browser. Flash can also store "flash cookies" on your system as well.<div>I would look at "about:plugins" and see what Firefox has loaded. Torbutton does a good job at stopping third party plugins, but if you specifically allow Flash and do not clear the cookie from Flash, you may have a problem.</div>
<div><br></div><div>Other than that, you have the right idea. :)</div><div><br></div><div><br><br><div class="gmail_quote">On Mon, Jul 12, 2010 at 8:45 AM, Matthew <span dir="ltr"><<a href="mailto:pumpkin@cotse.net">pumpkin@cotse.net</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div text="#000000" bgcolor="#ffffff">
<font face="Helvetica, Arial, sans-serif">Hello,<br>
<br>
I have been reading the Torbutton documentation (thanks, guys) and
have a question about the adversary capabilities. <br>
<br>
The first adversary capability is "inserting javascript". The
document says that "If not properly disabled, Javascript event
handlers and timers can cause the browser to perform network
activity after Tor has been disabled, thus allowing the adversary
to correlate Tor and Non-Tor activity and reveal a user's non-Tor
IP address." <br>
<br>
The third adversary capability is "inserting CSS". The document
says that "CSS can also be used to correlate Tor and Non-Tor
activity and reveal a user's Non-Tor IP address, via the usage of
CSS popups - essentially CSS-based event handlers that fetch
content via CSS's onmouseover attribute. If these popups are
allowed to perform network activity in a different Tor state than
they were loaded in, they can easily correlate Tor and Non-Tor
activity and reveal a user's IP address."<br>
<br>
I understand that Torbutton is useful for protecting privacy in
multiple ways. But I would like to address this specific issue if
I may.<br>
<br>
Let us imagine that a user surfs the net using Tor (and Polipo or
Privoxy). He has JavaScript installed and uses it for all sites.
He finishes his activities and then closes his browser. He then
wipes the following files and directories (I am using Ubuntu as my
example):<br>
<br>
/.mozilla/firefox/nameofuser/cookies.sqlite <br>
/.mozilla/firefox/</font><font face="Helvetica, Arial, sans-serif">nameofuser</font><font face="Helvetica, Arial, sans-serif">/downloads.sqlite <br>
/.mozilla/firefox/</font><font face="Helvetica, Arial, sans-serif">nameofuser</font><font face="Helvetica, Arial, sans-serif">/cookies.sqlite-journal<br>
/.mozilla/firefox/</font><font face="Helvetica, Arial, sans-serif">nameofuser</font><font face="Helvetica, Arial, sans-serif">/places.sqlite <br>
/.mozilla/firefox/</font><font face="Helvetica, Arial, sans-serif">nameofuser</font><font face="Helvetica, Arial, sans-serif">/places.sqlite-journal<br>
/.mozilla/firefox/</font><font face="Helvetica, Arial, sans-serif">nameofuser</font><font face="Helvetica, Arial, sans-serif">/formhistory.sqlite<br>
<br>
/.mozilla/firefox/nameofuser/Cache/<br>
<br>
Now I assume that these Javascript events and handlers and the CSS
handlers were downloaded into the Cache from when the user was
browsing using Tor. They would then be deleted as detailed above.
Therefore, when the user loads up Firefox and turns off the Tor
proxy settings, presumably the potential for JavaScript or CSS to
connect Tor and non-Tor activity and get the users real (non-Tor)
IP address is no longer a concern?<br>
<br>
Is this correct? Or am I missing something? Just to re-state: I
am only looking at this one issue - I am well aware of how useful
Tor button is in other areas!<br>
<br>
Thanks. <br>
</font>
</div>
</blockquote></div><br></div>