[tor-bugs] #3375 [Tor Client]: NEWNYM does not abandon open rendezvous circuits

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#3375: NEWNYM does not abandon open rendezvous circuits
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 Reporter:  rransom     |          Owner:  rransom           
     Type:  defect      |         Status:  needs_review      
 Priority:  critical    |      Milestone:  Tor: 0.2.1.x-final
Component:  Tor Client  |        Version:                    
 Keywords:              |         Parent:                    
   Points:              |   Actualpoints:                    
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Comment(by rransom):

 Replying to [comment:2 nickm]:
 > Looks like a plausible idea to me.
 >
 > Do we want to be using the same MaxCircuitDirtiness for rendezvous
 circuits?  It seems that this change would make us not only abandon
 circuits on newnym, but reintroduce to any hidden service that we want to
 stay connected to every MaxCircuitDirtiness seconds (current default 10
 min, I think).

 A rendezvous circuit's `timestamp_dirty` is reset every time a stream is
 attached to it, so this change would only cause clients to reintroduce to
 a hidden service if they had a long-lived stream open and had not opened a
 new stream to the HS in the last 10 minutes.  (If they don't have a long-
 lived stream open, Tor will currently close the circuit 10 minutes after
 the last time a stream was attached to it)  I don't see a problem with
 using a new circuit in that case, and it may be beneficial (e.g. for
 reliability reasons).

 > Is changing circuit_is_acceptable sufficient?  That is, will the having
 this circuit present but non-usable cause new introduction attempts to be
 made correctly, or will new attempts to connect to the hidden service fail
 while it's around?

 When I tested this patch, a new attempt to connect to a hidden service
 after NEWNYM succeeded (in refetching the descriptor, reintroducing to the
 HS, and building and using a second rendezvous circuit).

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/3375#comment:3>
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