[tor-bugs] #32563 [Core Tor/Tor]: Merge HSv3 spec fixes we found during onionbalance creation

[Tor Bug Tracker & Wiki]

#32563: Merge HSv3 spec fixes we found during onionbalance creation
-------------------------+-------------------------------------------------
     Reporter:  asn      |      Owner:  (none)
         Type:  defect   |     Status:  new
     Priority:  Medium   |  Milestone:  Tor: unspecified
    Component:  Core     |    Version:
  Tor/Tor                |   Keywords:  tor-hs scaling onionbalance
     Severity:  Normal   |  network-team-roadmap-september tor-spec
Actual Points:           |  Parent ID:  #26768
       Points:  0.2      |   Reviewer:
      Sponsor:           |
  Sponsor27-must         |
-------------------------+-------------------------------------------------
 There are a few issues with the v3 spec that we found out as we were
 implementing onionbalance. We should merge them.

 Examples:
 - https://github.com/asn-d6/stem/pull/2#discussion_r348847261
 - The MAC description in the descriptor encryption is wrong.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/32563>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online