[tor-commits] [meek/utls] Use the utls HelloRandomizedNoALPN handshake.

[dcf at torproject.org]

commit 90d82c205c0269b87de5a6956e485225f8a9a2cb
Author: David Fifield <david at bamsoftware.com>
Date:   Thu Jan 10 22:11:10 2019 -0700

    Use the utls HelloRandomizedNoALPN handshake.
    
    Since we cannot use any handshake that has a "h2" ALPN (like
    HelloFirefox_63 or HelloChrome_70), let's use a randomized handshake.
    HelloRandomizedNoALPN differs from HelloRandomized and
    HelloRandomizedALPN in that it always omits ALPN.
    
    The http.Transport still appears to make 10 independent connections,
    each with its own randomized fingerprint...
---
 meek-client/meek-client.go | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/meek-client/meek-client.go b/meek-client/meek-client.go
index 5853428..4f5aadd 100644
--- a/meek-client/meek-client.go
+++ b/meek-client/meek-client.go
@@ -451,18 +451,8 @@ func main() {
 		if err != nil {
 			return nil, err
 		}
-		uconn := tls.UClient(conn, config, tls.HelloChrome_Auto)
-		// We cannot call uconn.Handshake() here: it causes the server
-		// to use HTTP/2, when the client is still using HTTP/1.1,
-		// because net/http disables automatic HTTP/2 support when using
-		// DialTLS.
-		// https://github.com/golang/go/issues/21753
-		// "Auto-HTTP/2 is disabled by DialTLS being set"
-		// https://github.com/golang/go/issues/21336
-		// But: returning without calling uconn.Handshake causes the
-		// ClientHello to lack the ALPN extension entirely...
-		//
-		// err = uconn.Handshake()
+		uconn := tls.UClient(conn, config, tls.HelloRandomizedNoALPN)
+		err = uconn.Handshake()
 		return uconn, err
 	}