[tor-bugs] #20509 [Core Tor/Tor]: Directory authorities should take away Guard flag from relays with #20499 bug

[Tor Bug Tracker & Wiki]

#20509: Directory authorities should take away Guard flag from relays with #20499
bug
--------------------------------+------------------------------------
 Reporter:  arma                |          Owner:
     Type:  defect              |         Status:  new
 Priority:  Medium              |      Milestone:  Tor: 0.2.9.x-final
Component:  Core Tor/Tor        |        Version:
 Severity:  Normal              |     Resolution:
 Keywords:  028-backport, easy  |  Actual Points:
Parent ID:                      |         Points:
 Reviewer:                      |        Sponsor:
--------------------------------+------------------------------------

Comment (by arma):

 Replying to [comment:7 teor]:
 > Hang on, didn't we have a bug where clients would pick relays as their
 guard regardless of whether they had the Guard flag? How many versions ago
 was that?

 That was bug #17772 and its fix went into 0.2.7.6, which came out before
 0.2.8.1-alpha. Whereas directory guards went into 0.2.4.8-alpha. So
 clients running 0.2.4.x and 0.2.5.x and 0.2.6.x will have the #17772 bug.
 But I think they have bigger problems.

 > And do clients automatically get new guards when their existing guards
 lose the Guard flag? Or do they keep their old guards until they rotate?

 Great question. #17773 is the complicated mess you want to read to answer
 it. I *think* the summary of that ticket is that clients do in fact go
 find another Guard if their current one loses its flag. And we were
 thinking of changing that behavior, because it introduces other problems,
 but we haven't yet. Lucky us here.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/20509#comment:9>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online