The Operator Foundation

Operator makes usable tools to help people around the world with censorship, security, and privacy.

Shapeshifter

The Shapeshifter project provides network protocol shapeshifting technology (also sometimes referred to as obfuscation). The purpose of this technology is to change the characteristics of network traffic so that it is not identified and subsequently blocked by network filtering devices.

There are two components to Shapeshifter: transports and the dispatcher. Each transport provide different approach to shapeshifting. ShadowSwift is provided as a Swift library which can be integrated directly into applications.

If you are a tool developer working in the Swift programming language, then you are in the right place. If you are a tool developer working in other languages we have several other tools available to you:

A Go transports library that can be used directly in your application: shapeshifter-transports
A Kotlin transports library that can be used directly in your Android application (currently supports Shadow): ShapeshifterAndroidKotlin
A Java transports library that can be used directly in your Android application (currently supports Shadow): ShapeshifterAndroidJava

If you want a end user that is trying to circumvent filtering on your network or you are a developer that wants to add pluggable transports to an existing tool that is not written in the Swift programming language, then you probably want the dispatcher. Please note that familiarity with executing programs on the command line is necessary to use this tool. https://github.com/OperatorFoundation/shapeshifter-dispatcher

If you are looking for a complete, easy-to-use VPN that incorporates shapeshifting technology and has a graphical user interface, consider Moonbounce, an application for macOS which incorporates shapeshifting without the need to write code or use the command line.

Shapeshifter Transports

Shapeshifter Transports is a suite of pluggable transports implemented in a variety of langauges. This repository is an implementation of the Shadow transport in the Swift programming language.

If you are looking for a tool which you can install and use from the command line, take a look at shapeshifter-dispatcher instead.

ShadowSwift implements the Pluggable Transports 3.0 specification available here: https://github.com/Pluggable-Transports/Pluggable-Transports-spec/tree/main/releases/PTSpecV3.0 Specifically, they implement the Swift Transports API v3.0.

The purpose of the transport library is to provide a set of different transports. Each transport implements a different method of shapeshifting network traffic. The goal is for application traffic to be sent over the network in a shapeshifted form that bypasses network filtering, allowing the application to work on networks where it would otherwise be blocked or heavily throttled.

ShadowSwift

Shadowsocks is a fast, free, and open-source encrypted proxy project, used to circumvent Internet censorship by utilizing a simple, but effective encryption and a shared password. ShadowSwift is a wrapper for Shadowsocks that makes it available as a Pluggable Transport.

Prerequisites

The Swift programming language minimum version 5.6. If you are using a Linux system follow the instructions on swift.org to install Swift. If you are using macOS we recommend that you install Xcode.

Using the Library

Add the dependency to your project

This can be done through the Xcode GUI or by updating your Package.swift file

dependencies: [
        // Dependencies declare other packages that this package depends on.
        .package(url: "https://github.com/OperatorFoundation/ShadowSwift.git", from: "3.0.4"),
    ],

targets: [
        // Targets are the basic building blocks of a package. A target can define a module or a test suite.
        // Targets can depend on other targets in this package, and on products in packages this package depends on.
        .target(
            name: "MyApp",
            dependencies: [
                "ShadowSwift",
            ]),
        .testTarget(
            name: "MyAppTests",
            dependencies: ["MyApp"]),
    ],

Client:

Create a Shadow connection factory with a ShadowConfig and a swift Logger containing the password and cipher mode. For DarkStar mode, the password will be the server's persistent private key in hex.

let logger: Logger = Logger(label: "Shadow Logger")
LoggingSystem.bootstrap(StreamLogHandler.standardError)

let shadowConfig = ShadowConfig(key: publicKeyHex, serverIP: "127.0.0.1", port: 1234, mode: .DARKSTAR)
let factory = ShadowConnectionFactory(config: shadowConfig, logger: logger)

Connect using the client factory

guard var connection = factory.connect(using: .tcp) else 
{
    return
}

 connection.stateUpdateHandler = 
 {
    state in

    switch state
    {
        case .ready:
            print("Ready!")
        default:
            return
    }
}

Call .send and .receive on the client connection to send and receive data

Server:

Create a Shadow config containing the password and cipher mode. For DarkStar mode, the password will be the server's persistent private key in hex.

let shadowServerConfig = ShadowConfig(password: "privateKeyHex", mode: .DARKSTAR)

Create a Shadow Server with the host, port, ShadowConfig and Swift Logger.

guard let server = ShadowServer(host: "host", port: 2222, config: shadowServerConfig, logger: logger) else                
{
    return
}

Accept the connection

let connection = try server.accept()

Call .send and .receive on the server connection to send and receive data

let messageSent = connection.write(string: "test\n")
let maybeData = connection.read(size: expectedLength)

Credits

Shadowsocks was developed by the Shadowsocks team. whitepaper