[tor-bugs] #5229 [Ooni]: ooni-probe/bridget should make sure that random port numbers are not already taken

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#5229: ooni-probe/bridget should make sure that random port numbers are not
already taken
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 Reporter:  karsten  |          Owner:  hellais
     Type:  defect   |         Status:  new    
 Priority:  normal   |      Milestone:         
Component:  Ooni     |        Version:         
 Keywords:           |         Parent:  #5028  
   Points:           |   Actualpoints:         
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Comment(by rransom):

 Replying to [comment:4 karsten]:
 > Replying to [comment:2 rransom]:
 > > The plugin should use `SocksPort auto` and `ControlPort auto`.
 >
 > That might work, too.  We probably don't want to run Tor versions before
 0.2.2.26-beta, do we?

 Hopefully not.  0.2.1.x is no longer supported, and we have had security
 bugfixes on the 0.2.2.x branch since it became stable.

 > > > The directory name generation could also be improved, e.g., by using
 an internal counter.
 > >
 > > Or generate a random string containing at least 128 bits of entropy.
 (Use a real random number generator for this.)
 >
 > In theory, there's no need to introduce a random component here.  A
 single thread creates these directories.

 In practice, `datadir_basename =
 base64.b32encode(foozerkit.randombytes(16)).lower()` is simpler, and thus
 easier and less likely to break, than the non-random approaches you had in
 mind.  (See my safecookie-python tor-utils branch for the `randombytes`
 function if you don't already have one.)

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/5229#comment:6>
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