Silk Road forums

Discussion => Security => Topic started by: bp on July 07, 2011, 03:51 pm

Title: DNS leak when running Bitcoin 0.3.23 and Tor bundle together
Post by: bp on July 07, 2011, 03:51 pm
I keep seeing this message in yellow in the Vidalia log:

"Jul 07 08:19:05.171 [Warning] Your application (using socks4 to port 8333) is giving Tor only an IP address. Applications that do DNS resolves themselves may leak information. Consider using Socks4A (e.g. via privoxy or socat) instead. For more information, please see https://wiki.torproject.org/TheOnionRouter/TorFAQ#SOCKSAndDNS."

It shows up fairly often and a lot of connections are "srubbed" too, like:

"Jul 07 08:18:40.062 [Notice] We tried for 15 seconds to connect to '[scrubbed]' using exit 'TORy3'. Retrying on a new circuit."

I tried creating a bitcoin.conf file with    noirc=1 in it (only thing I could find that claimed to anatomize bitcoin over tor) but I still get it.

Would a bitcoin upgrade with socks4a be an easy noob fix? Is there simple a config I can do that won't need 10 years of Linix experience or way too much reading?

I'm running the FF4 windows bundle.


Is this a real problem?


Title: Re: DNS leak when running Bitcoin 0.3.23 and Tor bundle together
Post by: peaceloveharmony on July 07, 2011, 04:41 pm
No, its fine as long as you dont add nodes via URLs.
Title: Re: DNS leak when running Bitcoin 0.3.23 and Tor bundle together
Post by: MrTHC on July 08, 2011, 12:25 pm
No, its fine as long as you dont add nodes via URLs.

Can you elaborate on that? What would open a node?
Title: Re: DNS leak when running Bitcoin 0.3.23 and Tor bundle together
Post by: peaceloveharmony on July 08, 2011, 03:29 pm
Bitcoin connects to IP addresses so there is no host name resolution as long as you dont add nodes with the -addnode option using host names instead of IP addresses.
Title: Re: DNS leak when running Bitcoin 0.3.23 and Tor bundle together
Post by: ~shabang~ on July 08, 2011, 08:57 pm
Don't worry about the entries in the log file marked 'scrubbed' when unable to complete a circuit.

All that means is for some reason a circuit was unable to be completed, whether it timed out waiting for a response, or one of your TOR circuits Guard, Link or Exit nodes suddenly went offline or was inundated with traffic it couldn't handle before the TTL expired.

The 'scrubbed' part refers to the actuall address you were trying to reach. Vidalia doesn't store the addresses of .onion sites in its logs, it replaces them with 'scrubbed' so that they can't be recovered later by a third party. The name that shows up is the name of the exit node it was attempting to use.
Title: Re: DNS leak when running Bitcoin 0.3.23 and Tor bundle together
Post by: OneOfMany on July 09, 2011, 01:24 am
Bitcoin connects to IP addresses so there is no host name resolution as long as you dont add nodes with the -addnode option using host names instead of IP addresses.
To elaborate further. Bitcoin uses IP addresses directly instead of resolving a host name (like bitcoin.org). But Tor doesn't know this, so when sees the IP address and warns you the program might be looking up addresses without going through Tor.

At least that's my understanding, for the record I have not independently verified this.
Title: Re: DNS leak when running Bitcoin 0.3.23 and Tor bundle together
Post by: bp on July 09, 2011, 09:18 pm
Thanks, I feel a little better now.