[tor-bugs] #7971 [Tor]: review address lists in tor_addr_is_internal_()

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#7971: review address lists in tor_addr_is_internal_()
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 Reporter:  cypherpunks                |          Owner:                    
     Type:  defect                     |         Status:  new               
 Priority:  normal                     |      Milestone:  Tor: 0.2.4.x-final
Component:  Tor                        |        Version:                    
 Keywords:  tor-client 024-deferrable  |         Parent:                    
   Points:                             |   Actualpoints:                    
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Comment(by nickm):

 Summarizing the difficulty from #5166, to see if I understand them.

 Adding new addresses that clients will reject as internal when they hear
 about them is problematic to the extent that it lets you distinguish old
 clients from new clients.

 Adding new addresses that get rejected by "reject private:*" is
 problematic when clients and servers disagree about what addresses are
 'private': If a server rejects an address that a client doesn't expect it
 to reject, the client will mark the server as a bad exit in 0.2.3 (and
 under some circumstances in 0.2.4 too).  This could be deliberately
 triggered by a hostile website.

 This is a big enough nest of worms that I'm tempted to say that we should
 do a real solution, and that such a real solution needs to come in 0.2.5.
 The question remaining is whether _other_ cases of tor_addr_is_internal
 could change in 0.2.4, and if they did, whether there'd be much real
 benefit to that.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/7971#comment:4>
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