[tor-bugs] #7137 [Censorship analysis]: Build a tool that a censored person can run to discover why their Tor is failing to connect

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#7137: Build a tool that a censored person can run to discover why their Tor is
failing to connect
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 Reporter:  karsten              |          Owner:  runa
     Type:  project              |         Status:  new 
 Priority:  normal               |      Milestone:      
Component:  Censorship analysis  |        Version:      
 Keywords:  SponsorZ             |         Parent:      
   Points:                       |   Actualpoints:      
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Comment(by asn):

 I should mention that Arturo and I started developing a similar tool for
 OONI. It's called daphn3 and it's supposed to be able to derive the
 fingerprint that a DPI uses by using the firewall as an oracle.

 Unfortunately, we never got around to testing it or deploying it
 somewhere. It's currently sitting in the OONI codebase:
 https://gitweb.torproject.org/ooni-
 probe.git/blob/HEAD:/ooni/plugins/daphn3.py
 https://gitweb.torproject.org/ooni-
 probe.git/blob/HEAD:/ooni/protocols/daphn3.py
 I would estimate it needs 3-4 days of coding, polishing and testing before
 it's useful.

 For the record, daphn3 is only able to exploit DPI firewalls that look for
 strings of bytes. If the DPI firewall looks for regexps (or anything more
 complicated than that), daphn3 will not be able to derive the whole
 fingerprint.

 (We should probably write down how daphn3 works exactly. A not-very-
 helpful description can be found in #6349. Also, daphn3 is based on
 d0wser, and d0wser's description can be found here:
 https://trac.torproject.org/projects/tor/wiki/doc/OONI/Tests/d0wser )

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/7137#comment:3>
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