[tor-bugs] #31009 [Core Tor/Tor]: Tor lets transports advertise private IP addresses in descriptor

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#31009: Tor lets transports advertise private IP addresses in descriptor
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 Reporter:  phw           |          Owner:  (none)
     Type:  defect        |         Status:  new
 Priority:  Medium        |      Milestone:
Component:  Core Tor/Tor  |        Version:
 Severity:  Normal        |     Resolution:
 Keywords:                |  Actual Points:
Parent ID:                |         Points:  0.5
 Reviewer:                |        Sponsor:
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Comment (by arma):

 My first thought, in terms of a low-impact hack, would be: when Tor is
 building its extrainfo descriptor, it should notice that it's about to
 advertise an internal address, and if so, put in the main ipv4 address of
 that descriptor instead.

 (For internal and testing Tor networks, where the main ipv4 address is
 itself an internal address, no problem, we should use that.)

 I think that simple change would resolve the vast majority of the cases
 that we're seeing right now. Then we could imagine also adding a config
 option to be able to say "I want to write a different line about my obfs4
 PT into my extrainfo descriptor" -- but maybe that isn't an additional
 complexity that our operators actually need.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/31009#comment:3>
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