[tor-bugs] #2667 [Tor Relay]: Exits should block reentry into the tor network

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#2667: Exits should block reentry into the tor network
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 Reporter:  mikeperry  |          Owner:                    
     Type:  defect     |         Status:  new               
 Priority:  critical   |      Milestone:  Tor: 0.2.4.x-final
Component:  Tor Relay  |        Version:                    
 Keywords:             |         Parent:  #2664             
   Points:             |   Actualpoints:                    
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Changes (by proper):

 * cc: adrelanos@… (added)


Comment:

 To make this worse:
  * if you forbid reentry into the Tor network...
   * A good way to censor and monitor Tor users would be...
    * Put your network behind a transparent torified network.
    * Connect to nodes under your control.

 > I wonder if the better fix is to make the "transparent torify" process
 smarter (that is, write and maintain some "best practices" iptables rules
 that do the right thing), so it can recognize connections to the Tor
 network and let them through directly? It seems risky (full of
 opportunities for serious fail), but better than the other options I've
 heard so far.

 Please don't. The advantage of an correctly transparently torified network
 is, that there can be no IP/DNS leaks. If you allow some magic direct
 connections, transparent proxying will only be a usability feature, no
 security feature.

 If you really must... Please make it configurable thought an torrc option.

 TRANS_PORT_ALLOW_DIRECT_CONNECTIONS_TO_THE_TOR_NETWORK=1
 (Find better name. Default is 1. 0 disables the magic direct Tor network
 connection feature.)

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/2667#comment:16>
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