d5ae7562ac
The client and proxy use the net/http default transport to make round trip connecitons to the broker. These by default don't time out and can wait indefinitely for the broker to respond if the broker hangs and doesn't terminate the connection. |
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|---|---|---|
| broker | ||
| client | ||
| common | ||
| doc | ||
| proxy | ||
| server | ||
| .gitignore | ||
| .gitlab-ci.yml | ||
| .gitmodules | ||
| .travis.yml | ||
| CONTRIBUTING.md | ||
| go.mod | ||
| go.sum | ||
| LICENSE | ||
| README.md | ||
Snowflake
Pluggable Transport using WebRTC, inspired by Flashproxy.
Table of Contents
Usage
cd client/
go get
go build
tor -f torrc
This should start the client plugin, bootstrapping to 100% using WebRTC.
Dependencies
Client:
- pion/webrtc
- Go 1.10+
More Info
Tor can plug in the Snowflake client via a correctly configured torrc.
For example:
ClientTransportPlugin snowflake exec ./client \
-url https://snowflake-broker.azureedge.net/ \
-front ajax.aspnetcdn.com \
-ice stun:stun.l.google.com:19302
-max 3
The flags -url and -front allow the Snowflake client to speak to the Broker,
in order to get connected with some volunteer's browser proxy. -ice is a
comma-separated list of ICE servers, which are required for NAT traversal.
For logging, run tail -F snowflake.log in a second terminal.
You can modify the torrc to use your own broker:
ClientTransportPlugin snowflake exec ./client --meek
Test Environment
There is a Docker-based test environment at https://github.com/cohosh/snowbox.
FAQ
Q: How does it work?
In the Tor use-case:
- Volunteers visit websites which host the "snowflake" proxy. (just like flashproxy)
- Tor clients automatically find available browser proxies via the Broker (the domain fronted signaling channel).
- Tor client and browser proxy establish a WebRTC peer connection.
- Proxy connects to some relay.
- Tor occurs.
More detailed information about how clients, snowflake proxies, and the Broker fit together on the way...
Q: What are the benefits of this PT compared with other PTs?
Snowflake combines the advantages of flashproxy and meek. Primarily:
-
It has the convenience of Meek, but can support magnitudes more users with negligible CDN costs. (Domain fronting is only used for brief signalling / NAT-piercing to setup the P2P WebRTC DataChannels which handle the actual traffic.)
-
Arbitrarily high numbers of volunteer proxies are possible like in flashproxy, but NATs are no longer a usability barrier - no need for manual port forwarding!
Q: Why is this called Snowflake?
It utilizes the "ICE" negotiation via WebRTC, and also involves a great abundance of ephemeral and short-lived (and special!) volunteer proxies...
Appendix
-- Testing with Standalone Proxy --
cd proxy
go build
./proxy
More documentation on the way.
Also available at: torproject.org/pluggable-transports/snowflake