[tor-bugs] #6465 [Tor Relay]: Build abstraction layer around TLS

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#6465: Build abstraction layer around TLS
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 Reporter:  andrea     |          Owner:  andrea            
     Type:  project    |         Status:  needs_review      
 Priority:  major      |      Milestone:  Tor: 0.2.4.x-final
Component:  Tor Relay  |        Version:  Tor: unspecified  
 Keywords:             |         Parent:                    
   Points:             |   Actualpoints:                    
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Comment(by nickm):

 Replying to [comment:30 andrea]:
 > > General stuff: I'm perpetually terrified of breaking the handshake in
 a way
 > > to allow us to count as authenticated, or to process cells we
 shouldn't, or
 > > to send data we shouldn't, without actually completing the TLS
 handshake and
 > > verifying the other party with the Tor handshake. I'm also perpetually
 afraid
 > > of breaking the v2 or v1 TLS handshakes and not noticing because I
 only
 > > tested master against master.
 >
 > Hmm, good point.  Got any suggestions on how to test stuff like this?

 Right now, a combination of trying with different Tor versions and Tor
 versions with some of the handshakes disabled is the only way I know to to
 make sure the old handshakes work.  I don't know a way other than code
 audit to make completely sure that we can't handle any commands without
 having first authenticated; whenever it seems unclear, we could add
 defensive programming to make sure that it's impossible.

 We could maybe at some point hack together in the scripting language of
 anybody's choice an implementation of the various handshakes, and of some
 of their broken variants, as an attempt to better fuzz and test this
 stuff.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/6465#comment:34>
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