[tor-bugs] #26806 [Core Tor/Tor]: Check if Tor clients sometiems send duplicate cells on rendezvous circuits: Possible replay detected! An INTRODUCE2 cell with thesame ENCRYPTED section was seen

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#26806: Check if Tor clients sometiems send duplicate cells on rendezvous circuits:
Possible replay detected! An INTRODUCE2 cell with thesame ENCRYPTED section
was seen
------------------------------+------------------------------
     Reporter:  s7r           |      Owner:  (none)
         Type:  defect        |     Status:  new
     Priority:  Medium        |  Milestone:  Tor: unspecified
    Component:  Core Tor/Tor  |    Version:
     Severity:  Normal        |   Keywords:  tor-hs
Actual Points:                |  Parent ID:
       Points:                |   Reviewer:
      Sponsor:                |
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 As my v3 onion service is getting more and more popular, I started to get:
 {{{
 [warn] Possible replay detected! An INTRODUCE2 cell with thesame ENCRYPTED
 section was seen 32 seconds ago. Dropping cell.
 }}}

 I am inclined to think that this is more like a bug in Tor, maybe due to a
 race condition, rather than a replay attack.

 I also think this is what causes #15618 - dgoulet confirmed that the
 warning can be reproduced every time a second `ESTABLISH_RENDEZVOUS` is
 sent over the same circuit.

 This can probably go away if we fix #21084. I am not sure if that should
 be a parent ticket here or not, please change if you feel like it. I think
 I still have yawning's tool and notes about how to reproduce #21084.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/26806>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
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