[tor-bugs] #9349 [Flashproxy]: flashproxy facilitator: Allow clients to specify transports

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#9349: flashproxy facilitator: Allow clients to specify transports
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     Reporter:  asn         |      Owner:  dcf
         Type:  task        |     Status:  new
     Priority:  normal      |  Milestone:
    Component:  Flashproxy  |    Version:
   Resolution:              |   Keywords:
Actual Points:              |  Parent ID:  #7167
       Points:              |
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Comment (by dcf):

 Replying to [comment:18 asn]:
 > Replying to [comment:16 dcf]:
 > > `options.relays` should be indexed not by complete transport chains,
 but by transport chains excluding their last element. It should be
 possible for an obfs3|websocket client to talk to an obfs3|tcp relay, if
 there is a proxy that speaks both websocket and tcp. To be specific you
 should key by the tuple `("obfs3",)` and not `("obfs3", "websocket")`.
 > >
 >
 > Hm, would this functionality work currently?
 >
 > To have an obfs3|websocket client talk to an obfs3|tcp relay, doesn't
 the flashproxy have to first strip off the websocket frame? Does this
 happen currently? It was my impression that there is a bridge-side
 websocket transport that strips off the websocket frames.

 Yes, the way it works currently is that the proxy strips off the WebSocket
 container from the client, and adds its own WebSocket container again to
 the relay. The WebSocket API doesn't even give us visibility into the raw
 WebSocket stream; all we see are the bytes that are inside it.

 Remember, a flash proxy isn't tunnelling a client–server WebSocket
 connection between client and relay. There isn't even any WebSocket client
 code in flashproxy-client. Rather, the flash proxy transports
 client–server Tor TLS between client and relay, and it does this by means
 of separate, independent WebSocket connections to client and relay.

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9349#comment:28>
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