snowflake-pt

A Pluggable Transport using WebRTC

Status

• Successful automatic bootstraps with a WebRTC transport, using HTTP signaling (with optional domain fronting) speaking to a multitude of volunteer "snowflakes".
• Needs a lot more work though.

Usage

cd client/
go build
tor -f torrc

And it will start the client plugin with the following torrc options:

ClientTransportPlugin snowflake exec ./client \
--url https://snowflake-reg.appspot.com/ \
--front www.google.com

It will speak to the Broker, get matched with a "snowflake" browser proxy, and negotiate a WebRTC PeerConnection. After that, it should bootstrap to 100%.

To see logs, do tail -F snowflake.log in a second terminal.

You can modify the torrc to use your own broker, or remove the options entirely which will default to the old copy paste method (see torrc-manual):

ClientTransportPlugin snowflake exec ./client --meek

Also, it is possible to connect directly to the go-webrtc server plugin (skipping all the browser snowflake / broker stuff - see appendix)

Building a Snowflake Proxy

This will only work if there are any browser snowflakes running at all. To run your own, first make sure coffeescript is installed. Then, build with:

cd proxy/
cake build

(Type cake by itself to see possible commands)

Then, start a local http server in the proxy/build/ in any way you like. For instance:

cd build/
python -m http.server

Open a browser tab to 0.0.0.0:8000/snowflake.html.

TODO: Turn the snowflake proxy into a more deployable badge.

Appendix

-- Testing directly via WebRTC Server --

Using the server plugin uses an HTTP server that simulates the interaction that a client would have with a broker. Using the browser proxy (which will soon be the only way) requires copy and pasting between 3 terminals and a browser tab.

Edit server/torrc and add "-http 127.0.0.1:8080" to the end of the ServerTransportPlugin line:

ServerTransportPlugin snowflake exec ./server -http 127.0.0.1:8080

cd server/
go build
tor -f torrc

Edit client/torrc and add "-url http://127.0.0.1:8080" to the end of the ClientTransportPlugin line:

ClientTransportPlugin snowflake exec ./client -url http://127.0.0.1:8080/

-- Via Browser Proxy --

Open up three terminals for the client:

A: tor -f torrc SOCKSPort auto

B: cat > signal

C: tail -F snowflake.log

Then, in the browser proxy:

• Look for the offer in terminal C; copy and paste it into the browser.
• Copy and paste the answer generated in the browser back to terminal B.
• Once WebRTC successfully connects, the browser terminal should turn green. Shortly after, the tor client should bootstrap to 100%.

More documentation on the way.