Re: [T(A)ILS-dev] About bridges support

Delete this message

Reply to this message
Author: anonym
Date:  
To: The T(A)ILS public development discussion list
Subject: Re: [T(A)ILS-dev] About bridges support
03/02/11 23:21, intrigeri:
> Hi,
>
> anonym wrote (03 Feb 2011 20:14:24 GMT) :
>> Clearing Tor's data dir will induce hefty amounts of directory
>> fetches unnecessarily. I'd suggest reverting that commit and doing
>> something like the attached patch instead.
>
> I perfectly trust your proposal but to make sure I understand clearly
> what is going on, can you please confirm "UseBridges 1" is enough to
> workaround the network disconnect+reconnect bug[1] ?


Enabling UseBridges is not enough -- a bridge (working or not) is also
necessary, otherwise Tor doesn't even start ("...Failed to
parse/validate config: If you set UseBriges, you must specify at least
one bridge."), hence the need of the bogus/non-existent bridge. Let me
quote the bridge specification [1]:

> 3. Bridge users.
> Bridge users are like ordinary Tor users except they use encrypted
> directory connections by default, and they use bridge relays as both
> entry guards (their first hop) and directory guards (the source of
> all their directory information).


(Also see sections 3.2-3 for more detailed, affirmation)

So, once UseBridges is set AND one or more bridges are configured, both
in torrc, Tor will only go through bridges according to the spec. I've
tested and verified that this is working properly in T(A)ILS 0.6.2 using
a packet sniffer. Restarting Tor with or without clearing the data dir
makes no difference. It seems sound.

> [1] https://trac.torproject.org/projects/tor/ticket/2357
>
> If using this option is sufficient, I suggest this ticket is updated
> to reflect the current state of your testing process.


That ticket is about ReachableAddresses not working correctly, possibly
only in combination with a Vidalia bridge setup (note: there's nothing
about bridges in torrc in this setup). With this, ReachableAddresses
just doesn't work after Tor is restarted, and this inconsistent
behaviour should be treated as a bug. To me it seems unrelated that
UseBridges and a bridge configured *in* *torrc* works. Or am I mistaken?

Cheers!

[1]
https://gitweb.torproject.org/tor.git/blob/HEAD:/doc/spec/bridges-spec.txt