[tor-bugs] #29128 [Core Tor/Tor]: Place complete obfs4 bridge line in accessible location

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#29128: Place complete obfs4 bridge line in accessible location
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 Reporter:  phoul                                |          Owner:  (none)
     Type:  defect                               |         Status:  new
 Priority:  Medium                               |      Milestone:  Tor:
                                                 |  unspecified
Component:  Core Tor/Tor                         |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tor-pt, tor-doc,                     |  Actual Points:
  040-deferred-20190220                          |
Parent ID:  #30471                               |         Points:
 Reviewer:                                       |        Sponsor:
                                                 |  Sponsor28
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Changes (by teor):

 * status:  needs_information => new


Comment:

 Replying to [comment:11 phw]:
 > Replying to [comment:9 nickm]:
 > > Is there a standardized way for Tor to learn from the PT which fields
 it should put in the Bridge line?  It knows the `fingerprint`, and it has
 a good guess about the `address` field (though the PT may want to override
 that), but it  usually needs the PT's help to learn the `port` and any
 other fields.
 > [[br]]
 > I believe that all we need is in the `SMETHOD` line that Tor reads from
 the PT proxy's stdout.

 The complete PT line is sent to bridge users by BridgeDB.
 (That line *must* contain all the required information, otherwise bridge
 users wouldn't be able to use the bridge.)

 BridgeDB gets bridge PT lines from bridge extra-info document "transport"
 lines:
 https://gitweb.torproject.org/torspec.git/tree/dir-spec.txt#n1211

 These lines come from pt_get_extra_info_descriptor_string(), which you
 should be able to just dump to a file:
 https://github.com/torproject/tor/blob/989b6325d671744aacec191b181e8b0b0fee35be/src/feature/client/transports.c#L1613

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/29128#comment:12>
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