psiphon-tunnel-core

Psiphon 3 Tunnel Core README

Overview

A Psiphon client component implemented in Go. This component provide core tunnel functionality, handling all aspects of connecting to Psiphon servers and relaying traffic through those servers. Local proxies provide an interface for routing traffic through the tunnel.

This component does not include a UI and does not handle capturing or routing local traffic. These major aspects are handled by other parts of Psiphon client applications.

Status

This project is currently at the proof-of-concept stage. Current production Psiphon client code is available at our Psiphon 3 repository.

Setup

• Go 1.3 (or higher) is required.
• In this repository, run go build to make the psiphon-tunnel-core binary.
• Note that the psiphon package is imported using the absolute path github.com/Psiphon-Labs/psiphon-tunnel-core/psiphon; without further local configuration, go will use this version of the code and not the local copy in the repository.
• This project builds and runs on recent versions of Windows, Linux, and Mac OS X.

• Run ./psiphon-tunnel-core --config psiphon.config where the config file looks like this:

  {
      "PropagationChannelId" : "<placeholder>",
      "SponsorId" : "<placeholder>",
      "RemoteServerListUrl" : "<placeholder>",
      "RemoteServerListSignaturePublicKey" : "<placeholder>",
      "LogFilename" : "",
      "LocalHttpProxyPort" : 0,
      "LocalSocksProxyPort" : 0,
      "EgressRegion" : "",
      "TunnelProtocol" : "",
      "ConnectionWorkerPoolSize" : 10
  }
  

• Replace each <placeholder> with a value from your Psiphon network. The Psiphon server-side stack is open source and can be found in our Psiphon 3 repository. If you would like to use the Psiphon Inc. network, contact developer-support@psiphon.ca.

• The project builds and runs on Android. At this time, Android support is in the developer branch of Go, so build Go from source and use the Android NDK to build android/arm target support. See the sample AndroidApp README for more information about building the Go binary, along with a sample Android app that uses it.

Roadmap

TODO (proof-of-concept)

• Android app
  • open home pages
  • Go binary PIE, or use a Go library and JNI
  • settings UI (e.g., region selection)
• reconnection busy loop when no network available (ex. close laptop); should wait for network connectivity
• sometimes fails to promptly detect loss of connection after device sleep
• continuity and performance
  • always-on local proxies
  • multiplex across simultaneous tunnels
  • monitor health of tunnels; for example fail-over to new server on "ssh: rejected: administratively prohibited (open failed)" error?
• PendingConns: is interrupting connection establishment worth the extra code complexity?
• prefilter entries by capability; don't log "server does not have sufficient capabilities"
• log noise: "use of closed network connection"
• log noise(?): 'Unsolicited response received on idle HTTP channel starting with "H"'
• use ContextError in more places

TODO (future)

• meek enhancements
  • address this: https://trac.torproject.org/projects/tor/wiki/doc/meek#HowtolooklikebrowserHTTPS (new Go client is equivilent to current Windows client, but differs from current Android client which uses the same Android HTTPS stack used by regular apps)
• SSH compression
• preemptive reconnect functionality
  • unfronted meek almost makes this obsolete, since meek sessions survive underlying HTTP transport socket disconnects. The client could prefer unfronted meek protocol when handshake returns a preemptive_reconnect_lifetime_milliseconds.
• split tunnel support
• implement page view stats
• implement local traffic stats (e.g., to display bytes sent/received)
• control interface (w/ event messages)?
• upstream proxy support
• support upgrades
  • download entire client
  • download core component only
• try multiple protocols for each server (currently only tries one protocol per server)
• support a config pushed by the network
  • server can push preferred/optimized settings; client should prefer over defaults
  • e.g., etablish worker pool size; multiplex tunnel pool size
• overlap between httpProxy.go and socksProxy.go: refactor?

Licensing

Please see the LICENSE file.

Contacts

For more information on Psiphon Inc, please visit our web site at:

www.psiphon.ca