[tor-bugs] #3122 [Tor Client]: Write and use constant-time comparison functions

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#3122: Write and use constant-time comparison functions
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 Reporter:  rransom      |          Owner:  ioerror           
     Type:  enhancement  |         Status:  new               
 Priority:  major        |      Milestone:  Tor: 0.2.1.x-final
Component:  Tor Client   |        Version:                    
 Keywords:               |         Parent:                    
   Points:               |   Actualpoints:                    
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Comment(by rransom):

 Replying to [comment:8 nickm]:
 > I. Memcmp

 > 1. Define a new tor_memcmp and a new tor_memneq.  Both should be data-
 independent.  Define a fast_memcmp that aliases the platform memcmp().
 That's just there so that any unadorned memcmp() in our code can be called
 "incorrect".

 See [http://repo.or.cz/w/tor-utils/rransom.git/shortlog/refs/heads/tor-
 safe-memcmp tor-safe-memcmp in my tor-utils repo] (
 !ssh://mob@repo.or.cz/srv/git/tor-utils/rransom.git tor-safe-memcmp ) for
 tor_memcmp and a minimal unit test.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/3122#comment:13>
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