Re: funneling a wireless net's outbound connections through tor

[Scott Bennett <bennett@xxxxxxxxxx>]

     On Mon, 01 Oct 2007 15:19:26 +0100 Mike Cardwell <tor@xxxxxxxxxxxxxxxxxx>
wrote:
>Scott Bennett wrote:
>
>>> If you set up something like that you're opening up all sorts of attacks 
>>> against the people who use your service. If they don't know that all of 
>>> their plain text traffic can be read and modified by, "dodgy," exit 
>>> nodes, and almost certainly *will* be at some point...
>>      How will they be subject to any greater number of possible attacks
>> if their connections are funneled through tor than if they are not?  They
>> can go to any of several coffee shops in the area and use unencrypted,
>> completely unprotected, free or paid wireless services.  They just can't
>> do that at home.  If you see some way by which anonymizing their TCP
>> source addresses and their UDP port 53 (name service) packets' source
>> addresses when they access the Internet at home will cause them to suffer
>> more attacks than they will in any public location or, for that matter,
>> from a direct connection in their own dwelling if they had one, please
>> enlighten me.
>
>If they use an Internet cafe, their traffic is subject to being 
>monitored. If they use Tor it is *also* subject to being modified.

     If they go to a coffee shop or other location with free wireless
access, their traffic is also subject to being modified, but at *any
and every* hop between their computer and the destination, unless they
use end-to-end encryption anyway.
>
>Example 1:
>
>  [deleted as not unique to the tor environment  --SB]
>
>Example 2:
>
>  [deleted as not unique to the tor environment  --SB]
>
>Scary huh?

     Of course.  But in my intended setup, the only places that could
happen would be in my equipment, the exit node, the destination, or the
hops between the exit node and the destination.  It's not going to happen
in my equipment because I don't do that sort of thing and wouldn't have
the time or energy to devote to it even if I did do that kind of thing.
That leaves the exit node, the destination, and the hops between them.
     If the traffic does not go through tor, then those things could
happen at any of the up to 32 hops normally allowed for a TCP connection.
I do not see how reducing the number of potential points of attack
increases the risk.
>
>Of course, you could argue that the person running the Internet cafe or 
>the ISP could do that, but I am inclined to believe it's much more 
>likely to occur on the Tor network than in those cases.

     So could anyone along the path of an ordinary, unencrypted TCP link.
Some governments apparently do this sort of thing already, most likely
including the U.S. government.
>
>>      Aside from that, the only IP addresses that could conceivably be
>> discovered would either be the one temporarily assigned to my connection
>> or the one assigned on a private network by my wireless router via DHCP.
>>      In any case, I still would appreciate helpful information, so I'll
>> repeat my questions here, quoting from my original query:
>
>The anonymity of the IP address is not at issue here. The issue is, by 
>using Tor, you allow the possibility of exit nodes monitoring and 
>modifying traffic, so you should only use Tor if you truly understand 
>these issues and how to deal with them.

     I see.  The elitist approach to limiting use of damned good software.
Reminds me of David Sternlight claiming that there was no reason for anyone
to use PGP and therefore people shouldn't bother with it.  It was ridiculous
on its face, yet he persisted in trolling the PGP news groups with it for
years.  Do you work for the NSA by any chance?  (Like you would really say
so if you did.  Right.)
>
>IMHO. There's no need to use Tor for general web browsing, and at the 
>end of the day it probably makes your online experience more dangerous 
>rather than less dangerous.
>
     Then perhaps you should get permission to update the tor web pages and
documentation.  After all, we wouldn't want all that general web browsing
traffic to help hide traffic that certain governments really don't want
hidden.  And I'm sure that Roger Dingledine et al. really don't want to
promote widespread use of all their hard work for something so mundane as
general web browsing.  Feh.
     Again, if someone knows the answers to the questions I've now
posted twice, please advise.  I know I can probably figure it out by
trial and error, but it would be messy, and I don't have a spare
computer at present to do that properly.  Testing it from the same computer
runs into problems with routing tables, arp responses from the wrong
interfaces, etc.


                                  Scott Bennett, Comm. ASMELG, CFIAG
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