[tor-bugs] #27841 [Core Tor/Tor]: Surprise race: Intro point closes circuit after NACK, at the same time as client tries to extend circuit to new intro point

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#27841: Surprise race: Intro point closes circuit after NACK, at the same time as
client tries to extend circuit to new intro point
-------------------------------------------------+-------------------------
 Reporter:  asn                                  |          Owner:  neel
     Type:  defect                               |         Status:  closed
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  0.3.5.x-final
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:  fixed
 Keywords:  tor-hs dos 035-backport              |  Actual Points:
  040-backport 041-backport                      |
Parent ID:                                       |         Points:
 Reviewer:  dgoulet                              |        Sponsor:
                                                 |  Sponsor27
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Comment (by teor):

 Replying to [comment:32 dgoulet]:
 > Replying to [comment:31 nickm]:
 > > Is there a flag we can stop giving them?
 >
 > We would need to remove HSIntro=4 basically from the 032, 033 and 034
 relays so the service will go in legacy mode and this bug is not in the
 legacy code.

 We could make working versions declare a new HSIntro version, and then
 make clients require that version.

 When we fix high-impact bugs in future, we should consider adding a new
 protocol version, and making clients require it. That's what protocol
 versions are for,

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/27841#comment:35>
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