[tor-bugs] #18456 [Core Tor/Tor]: Exits on 0.2.7 publicise all their IP addresses in their descriptor

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#18456: Exits on 0.2.7 publicise all their IP addresses in their descriptor
--------------------------+------------------------------------
 Reporter:  teor          |          Owner:
     Type:  defect        |         Status:  needs_review
 Priority:  Medium        |      Milestone:  Tor: 0.2.9.x-final
Component:  Core Tor/Tor  |        Version:  Tor: 0.2.7.2-alpha
 Severity:  Normal        |     Resolution:
 Keywords:                |  Actual Points:  0.2
Parent ID:                |         Points:  3
 Reviewer:                |        Sponsor:
--------------------------+------------------------------------
Changes (by teor):

 * status:  new => needs_review
 * actualpoints:   => 0.2


Comment:

 Please see my branch bug18456 on https://github.com/teor2345/tor.git
 The corresponding torspec patch is in #19453.

 I fixed this issue by making ExitPolicyRejectPrivate only reject IP
 addresses we are going to put in the descriptor anyway (that is, the
 relay's advertised IPv4 and IPv6 address).

 Then, I added another option ExitPolicyRejectLocalInterfaces that also
 blocks the IPv4 and IPv6 OutboundBindAddresses, and the configured port
 addresses, and any interface addresses. (If a specific bind address is
 configured for the ORPort and DirPort, it is included by both options.
 This is ok, and necessary because of public-to-public address redirection.
 Also, any duplicate rules are removed.)

 I didn't modify the sample torrcs, but I can do that if we think it's a
 good idea.

 I made this patch on master because we've made multiple changes to this
 code since 0.2.7.2-alpha. And it's not really a security issue.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/18456#comment:6>
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