Today I deployed the turbotunnel branch to the Snowflake public bridge. It's a triple-mode bridge, compatible with current Snowflake clients, Turbo Tunnel with KCP, and Turbo Tunnel with QUIC. https://bugs.torproject.org/33336#comment:8
To go with it there are special builds of Tor Browser that use turbotunnel-kcp and turbotunnel-quic respectively. To try these, just select "Configure", then "Tor is censored in my country", then "Select a built-in bridge", then choose snowflake. Alternatively, enable snowflake at about:preferences#tor. https://people.torproject.org/~dcf/pt-bundle/tor-browser-snowflake-turbotunn... https://people.torproject.org/~dcf/pt-bundle/tor-browser-snowflake-turbotunn...
The purpose of having two bundles is so we can evaluate both KCP and QUIC and see if either offers a compelling advantage over the other. My thinking is that after this experimental phase, we'll choose one of the two and deploy only that one. The experimental bundles will stop working after 2020-04-15, when they will be liable to self-update to an ordinary alpha and lose their Turbo Tunnel nature.
Here are tips on running the experimental bundles simultaneously and alongside your normal Tor Browser. You just have to change some port numbers to avoid conflicts. https://trac.torproject.org/projects/tor/wiki/doc/TorBrowser/Hacking#Launchi... tar xf tor-browser-snowflake-turbotunnel-kcp-9.5a5-20200215/tor-browser-linux64-9.5a5_en-US.tar.xz mv tor-browser_en-US tor-browser_en-US_kcp cd tor-browser_en-US_kcp export TOR_SOCKS_PORT=9250 export TOR_CONTROL_PORT=9251 sed -i -e 's/Port 915/Port 925/' ./Browser/TorBrowser/Data/Tor/torrc-defaults ./start-tor-browser.desktop
tar xf tor-browser-snowflake-turbotunnel-quic-9.5a5-20200215/tor-browser-linux64-9.5a5_en-US.tar.xz mv tor-browser_en-US tor-browser_en-US_quic cd tor-browser_en-US_quic export TOR_SOCKS_PORT=9350 export TOR_CONTROL_PORT=9351 sed -i -e 's/Port 915/Port 935/' ./Browser/TorBrowser/Data/Tor/torrc-defaults ./start-tor-browser.desktop You may also want to go to the Customize... menu and choose different themes (default/light/dark) to help distinguish the browsers.
One thing I didn't think about is enabling client logging by default. If you need a log for debugging, you'll have to manually add "-log snowflake-client.log" to the "ClientTransportPlugin snowflake" line in Browser/TorBrowser/Data/Tor/torrc-defaults.
The Turbo Tunnel browsers are meant to keep working even after you've left them idle for a long time, and even if your Snowflake proxy dies. When a proxy dies, your connection will hang for at least 30 s--maybe longer if a replacement isn't immediately available. Occasional hangs are expected (at least until #25723 is done), but it should always recover within a few minutes at the outmost.