[tor-bugs] #13667 [Tor]: Prevent port scanning of hidden services

[Tor Bug Tracker & Wiki]

#13667: Prevent port scanning of hidden services
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 Reporter:  arma             |          Owner:
     Type:  defect           |         Status:  new
 Priority:  normal           |      Milestone:  Tor: 0.2.5.x-final
Component:  Tor              |        Version:
 Keywords:  SponsorR tor-hs  |  Actual Points:
Parent ID:                   |         Points:
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 If you connect to a hidden service that's listening on virtual port 5222,
 and send it a begin cell for port 80, it will send you back an end cell
 but leave the circuit up.

 I actually thought the design was more defensive: that if you ever asked
 for a virtual port that wasn't assigned, then it would close the circuit
 on you, to prevent scanning to find out what ports *are* open.

 But it turns out I never built it that way. We should fix it.

 With thanks to Ivan Pustogarov for noticing.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/13667>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
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