PrivacyNow is a BadExit (was Re: PrivacyNow node has misconfigured OpenDNS account)

[Sebastian Hahn]

On Apr 15, 2010, at 9:11 AM, Scott Bennett wrote:

>     On Thu, 15 Apr 2010 08:25:07 +0200 Sebastian Hahn <mail at sebastianhahn.net 
> >
> wrote:
>> On Apr 15, 2010, at 8:17 AM, Scott Bennett wrote:
>>> Unfortunate (IMO), the latest versions have the support for .exit
>>> either disabled or deleted, apparently leaving us no easy way to
>>> perform
>>> such tests.  I've asked recently on this list whether some other
>>> easy way
>>> were available, but have been met with silence, so I assume that  
>>> there
>>> still is none.
>>
>> If you want the functionality, feel free to set the AllowDotExit
>> config option
>> to 1. Note that this can't be recommended, because it opens you up  
>> for
>
>     That is what I have been doing in order to be able to test for  
> exit
> misbehavior.  However, the ChangeLog notes under "Minor bugfixes" for
> 0.2.2.9-alpha the following:
>
> 	- Resume handling .exit hostnames in a special way: originally we
> 	stripped the .exit part and used the requested exit relay. In
> 	0.2.2.1-alpha we stopped treating them in any special way, meaning
> 	if you use a .exit address then Tor will pass it on to the exit
> 	relay. Now we reject the .exit stream outright, since that behavior
> 	       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> 	might be more expected by the user. Found and diagnosed by Scott
> 	??????????????????????????????????
> 	Bennett and Downie on or-talk.
>
> I understood the "Now we reject" part as meaning that the .exit  
> support had
> been completely removed.  I do not understand why that behavior  
> "might be
> more expected by the user."  In any case, the above note is why I've  
> paused
> at 0.2.2.7-alpha while waiting to discover some fairly easy-to-use  
> alternative
> method of testing exit behavior.

Ah no, that's not what is meant here. The idea is that when .exit is  
disabled,
we reject connections to some domain ending in .exit, instead of passing
that URL to the exit node. This is more expected behaviour because there
is no .exit tld currently, so people telling to to go to xyz.exit are  
most likely
thinking that they are talking to a tor with the .exit functionality  
enabled.

>
>> attacks where the exit node can choose who your exit is going to be,
>> unless you use encrypted protocols when webbrowsing only.
>>
>     Regarding the attack route you mention, I have some firefox plug- 
> ins
> like NoRedirect and RefreshBlocker installed in addition to the  
> recommended
> plug-ins (including QuickJava, NoScript, and Torbutton especially)  
> that should
> help with automated stuff, and I'm in the habit of checking the  
> actual URLs
> in links before using the links manually.  In many cases, I don't  
> even use
> firefox to get stuff from the links, but rather do a copy-and-paste  
> to a
> wget(1) or some other downloader command in an xterm(1), so I have  
> plenty of
> opportunity to notice that sort of interference.  If those  
> strategies still
> miss something, please do let me know.

I suppose you still load images and possibly other resources, too;
those can be fetched from arbitrary locations unless disabled via
special-purpose addons like RequestPolicy.

>>>> # This file was generated by Tor; if youedit it, comments will not
>>>> be pres=
>>>
>>>    I think the comment may be a lie.  It's most likely a torrc
>>> produced by
>>> vidalia, not tor.  (Someone please correct me if I've forgotten some
>>> special
>>> case in which tor does rewrite a torrc.)
>>
>> I think it is more likely that the file was written by Tor, via the
>> SAFECONF
>> torctl command.
>>
>     Okay, I guess I had forgotten tor implemented such a command,  
> but who
> is issuing the command?  Vidalia?
>     Thanks for the information, Sebastian.

Yes, Vidalia as the only Tor controller in a typical setup would be  
issuing
the saveconf command.

Sebastian
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