[tor-bugs] #3290 [- Select a component]: Circuit reuse for FTP (and other?) multi-connection protocols

[Tor Bug Tracker & Wiki]

#3290: Circuit reuse for FTP (and other?) multi-connection protocols
----------------------------------+-----------------------------------------
 Reporter:  supercyborg           |          Owner:     
     Type:  enhancement           |         Status:  new
 Priority:  normal                |      Milestone:     
Component:  - Select a component  |        Version:     
 Keywords:  FTP                   |         Parent:     
   Points:                        |   Actualpoints:     
----------------------------------+-----------------------------------------
 Some protocols, such as FTP (in passive mode) use 2 connections, one for
 control and a second one for data.  Smarter FTP servers will not allow a
 data connection coming from an IP different than the control connection.

 Could an enhancement be made so that TOR recognizes an already established
 control connection to a particular IP on port 21 (in the case of FTP), and
 then reuses the same circuit on which that control connection was
 established to establish the data connection (if to the same IP)?  This
 would make both connections appear as coming from the same IP/exit-node
 and not make the FTP server suspicious.

 Of course, this behavior could be disabled by default (to keep current
 behavior) and enabled from the config file (a directive like
 ReuseCircuitsForSameHostConnections).

 This would greatly enhance usability of FTP over TOR, which otherwise
 works fine if such behavior happens "accidentally" (effectively no more
 than 1 in 5 or 6 times, because of the number of established circuits, 5
 or 6, and TOR's randomness in assigning circuits to new connections)

 Sorry if this has already been addressed, I couldn't find any information
 on whether or not it has been.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/3290>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online