[tor-bugs] #24432 [Obfuscation/BridgeDB]: The meek<->moat tunneling isn't set up correctly

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#24432: The meek<->moat tunneling isn't set up correctly
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 Reporter:  isis                  |          Owner:  isis
     Type:  defect                |         Status:  closed
 Priority:  High                  |      Milestone:
Component:  Obfuscation/BridgeDB  |        Version:
 Severity:  Normal                |     Resolution:  fixed
 Keywords:  moat bridgedb-dist    |  Actual Points:
Parent ID:  #24689                |         Points:  2
 Reviewer:                        |        Sponsor:  SponsorM
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Changes (by mcs):

 * cc: dcf (added)


Comment:

 (I added dcf to the Cc in case he has any insight into problem 1 below).

 Thanks for your work on this Isis! I feel like we are very close to having
 a working system. Kathy and I have found two problems so far, but I am not
 ready to reopen this ticket yet because I am not sure what component is at
 fault.

 '''Problem 1:''' The meek tunnel does not work reliably for us.
 Specifically, if we use curl as the SOCKS client it seems to always work
 and if we use Tor Browser it does not. When we test with our own meek-
 server + BridgeDB, things also work fine. I am having trouble debugging
 the meek-client code, probably due to my lack of golang knowledge, but I
 wonder if there is an incompatibility between the meek-client we are
 running and the meek-server that you are running. What version of meek-
 server are you using at tor-bridges-hyphae-channel.appspot.com? Kathy and
 I are using a meek-client that was built from dcf's ​bug24642 branch (and
 I don't know of any recent changes to meek that would cause this kind of
 communication problem).

 Another data point: if I insert an socat pipe between the meek-client
 SOCKS port and Tor Browser, it started working. Maybe there is a data
 buffering issue at work here. All of our client side testing so far has
 been on macOS.

 '''Problem 2:''' When we do manage to send a good `check` request (one
 that includes the correct response and challenge), we always receive a "No
 bridges available to fulfill request" response. We tried with both
 "vanilla" and "obfs4" transports. Here is a sample response:
   {"errors": [{"status": "Not Found", "code": 404, "detail": "No bridges
 available to fulfill request: None.", "version": "0.1.0", "type": "moat-
 bridges", "id": 6}]}
 Is the Moat responder throttling things so we do not receive too many
 bridges? I don't think we have ever received any bridges from the
 production BridgeDB server via Moat, but even if we did I thought BridgeDB
 would send back the same set of bridges if we ask again. I can get new
 bridges repeatedly if I use a browser to interact with
 https://bridges.torproject.org/bridges?transport=obfs4.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24432#comment:10>
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