[tor-bugs] #29077 [Obfuscation/meek]: uTLS for meek-client camouflage

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#29077: uTLS for meek-client camouflage
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 Reporter:  dcf               |          Owner:  dcf
     Type:  enhancement       |         Status:  new
 Priority:  Medium            |      Milestone:
Component:  Obfuscation/meek  |        Version:
 Severity:  Normal            |     Resolution:
 Keywords:  moat utls         |  Actual Points:
Parent ID:                    |         Points:
 Reviewer:                    |        Sponsor:
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Comment (by dcf):

 Yeah I did some tests today with `HelloRandomizedNoALPN`, 400 trials
 against each of 3 servers.
 ||||=**ajax.aspnetcdn.com** =||
 ||  284||no error ||
 ||   80||remote error: tls: handshake failure ||
 ||   36||tls: server selected unsupported group ||
 ||||=**golang.org** =||
 ||  335||no error ||
 ||   65||remote error: tls: handshake failure ||
 ||||=**www.cloudflare.com** =||
 ||  400||no error ||

 `HelloRandomizedNoALPN` [https://github.com/refraction-
 networking/utls/blob/a89e7e6da482a5a0db02578fc606ace9ccfbea62/u_parrots.go#L557-L564
 unconditionally includes] sec256r1 and sec384r1, but it doesn't seem to
 cause a problem unless it also happens to choose TLSv1.3 (which
 `Firefox_60` always does). 100% of the failures used a fingerprint with
 TLSv1.3, while only 28% of the successes did. I haven't dug deeper to see
 what the difference between the success and failure TLSv1.3 handshakes is.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/29077#comment:6>
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