[tor-bugs] #3263 [Tor Relay]: only publish new descriptor if onion key has changed

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#3263: only publish new descriptor if onion key has changed
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 Reporter:  arma       |          Owner:                    
     Type:  defect     |         Status:  needs_review      
 Priority:  normal     |      Milestone:  Tor: 0.2.3.x-final
Component:  Tor Relay  |        Version:                    
 Keywords:             |         Parent:                    
   Points:             |   Actualpoints:                    
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Comment(by nickm):

 Replying to [comment:1 arma]:
 > See my bug3263 branch.
 >
 > In particular, it needs review of:
 >
 > A) Should I be doing the key comparison inside the mutex? I think no.

 Indeed no.  `set_onion_key` is only called from the main thread, and is
 the only thing that can change `onionkey`.

 > B) Are there other things that init_keys() does that *do* want a new
 descriptor to be uploaded? I worry we're swinging the pendulum the other
 way and uncovering bugs that were masked by the "always republish" bug.

 I had a quick look through the code, and the only iffy case I can find is
 that we call init_keys if `options_transition_affects_workers()` detects a
 change in public_server_mode, whereas
 `option_transition_affects_descriptors()` doesn't check
 public_server_mode.  If you think that's safe, let's merge this.  If you
 want to add a check for public_server_mode() transition, that's fine too.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/3263#comment:3>
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