[tor-bugs] #8402 [Tor]: Tor should help its transport proxy use a proxy, if needed.

[Tor Bug Tracker & Wiki]

#8402: Tor should help its transport proxy use a proxy, if needed.
-------------------------+-------------------------------------------------
     Reporter:  asn      |      Owner:
         Type:  defect   |     Status:  needs_review
     Priority:  major    |  Milestone:  Tor: 0.2.6.x-final
    Component:  Tor      |    Version:
   Resolution:           |   Keywords:  tor-bridge pt flashproxy, tbb-
Actual Points:           |  needs, tbb-helpdesk-frequent, tbb-tor-
       Points:           |  backported-3.6.1
                         |  Parent ID:
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Comment (by dcf):

 Replying to [comment:31 asn]:
 > So, should we do David's suggestion? I think we all agree that it's
 better than the informationless `PROXY DONE` message that we currently do.
 >
 > Yawning mentioned the problem that there are already versions of
 flashproxy/FTE/meek that implement the old proposal (only send `PROXY
 DONE`) and Tor would get confused if we changed that to `PROXY
 socks5://tor:test1234 at 198.51.100.1:8000`.
 >
 > Maybe we could change it to `PROXY DONE
 socks5://tor:test1234 at 198.51.100.1:8000` and treat the last part as
 optional but `SHOULD` do?

 It would be better for the PROXY line to have more information, but at
 this point it may not be worth breaking the interface of deployed
 programs. There's a de-facto standard now that there's code in the wild.

 My use case was a narrow one. It was: I want to have a --proxy command-
 line option in meek-client. The command line overrides anything set
 through the PT protocol. (The --port option in e.g. websocket-server works
 the same way: it overrides TOR_PT_SERVER_BINDADDR and listens on the port
 you give it; then informs tor that it was ignored through the SMETHOD
 line.) I want to be able to at least inform tor that I am ignoring its
 proxy setting by telling it the proxy I'm actually going to use.

 The use case is not totally coherent because meek-client can also take a
 proxy parameter per-bridgeline, which overrides the command line and the
 PT protocol (see [https://gitweb.torproject.org/pluggable-
 transports/meek.git/blob/77e4bff0fb29b214fb3641b943da5c809b29aff3:/doc
 /meek-client.1.txt man page]). (If it seems weird to use a non-global HTTP
 proxy, i.e., not just use HTTPSProxy for all transports, think of the use
 case of chaining one proxy to another, like
 [https://lists.torproject.org/pipermail/tor-dev/2014-March/006356.html
 meek-in-Lantern].) So it's possible that even if the PROXY line gives a
 transport URL, the actual proxy could be different, set dynamically with a
 SOCKS arg.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/8402#comment:32>
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