[tor-bugs] #29293 [Obfuscation/Snowflake]: New Design for client -- broker protocol for Snowflake

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#29293: New Design for client -- broker protocol for Snowflake
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 Reporter:  cohosh                      |          Owner:  (none)
     Type:  task                        |         Status:  new
 Priority:  High                        |      Milestone:
Component:  Obfuscation/Snowflake       |        Version:
 Severity:  Normal                      |     Resolution:
 Keywords:  snowflake, bridges, broker  |  Actual Points:
Parent ID:                              |         Points:
 Reviewer:                              |        Sponsor:  Sponsor19
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Comment (by dcf):

 One of the problems with the current client–broker protocol is its use of
 HTTP response codes to carry some of the information in the broker's
 response.
   https://gitweb.torproject.org/pluggable-
 transports/snowflake.git/tree/client/lib/rendezvous.go?id=6399ef9d4fa7d1dced903b43f329a43d3a80dfc7#n98
 For example, when the client requests /client, the broker returns either a
 200 with a response body, an empty 503, or an empty 400. This is awkward
 when doing rendezvous over non-HTTP channels, or even over AMP cache,
 which doesn't reliably pass through the server's original status code (see
 comment:24:ticket:25985). As it is now, if the client is operating in HTTP
 mode, it needs to look at the status code; but if it's operating in AMP
 cache mode, it needs a separate code path that ignores the status code and
 instead looks for the equivalent information somewhere in the response
 body.

 It would be easier if all the necessary information in the broker's
 response were in the HTTP body, because that's easier to port to other
 channels.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/29293#comment:2>
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