[tor-bugs] #29430 [Applications/Tor Browser]: Use uTLS for meek TLS camouflage in Tor Browser

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#29430: Use uTLS for meek TLS camouflage in Tor Browser
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 Reporter:  dcf                       |          Owner:  tbb-team
     Type:  enhancement               |         Status:  new
 Priority:  Medium                    |      Milestone:
Component:  Applications/Tor Browser  |        Version:
 Severity:  Normal                    |     Resolution:
 Keywords:  meek utls                 |  Actual Points:
Parent ID:                            |         Points:
 Reviewer:                            |        Sponsor:
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Changes (by yawning):

 * cc: yawning (added)


Comment:

 Replying to [comment:4 mcs]:
 > Kathy and I agree: if we are planning to switch to obfs4proxy's meek
 client implementation (which seems like a good option to us), we should
 change Tor Launcher to use SOCKS args with the meek PT that it spins up
 for Moat.
 >
 > Georg, is it worthwhile for us to do that work in Tor Launcher soon, or
 should we first resolve the "meek-client or obfs4proxy?" question?

 For what it's worth, I also think that changing Tor Launcher to do so is
 orthogonal from which meek implementation is being used, since the new
 code will work with both implementations (unless meek-client is doing
 something extremely surprising under the hood).

 I aim to keep the bridge lines between meek-client and meek_lite as
 compatible as possible.

 Currently the differences between the two implementations are as follows:

  * (config) meek_lite's `utls` option understands `HelloChrome_71`.

  * (config) meek_lite will use `HelloFirefox_Auto` if no `utls` option is
 specified.

  * (config) meek_lite has a (misnamed according to some) option
 `disableHPKP`.

 So, all meek-client bridge lines will work with meek_lite (though the TLS
 fingerprint may differ).

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/29430#comment:5>
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