Swift

SSH Through a SOCKS Proxy

Demonstrates connecting to an SSH server through a SOCKS4 or SOCKS5 proxy. Set the SOCKS properties before calling Connect, and set SocksVersion to match the proxy server.

Background: SOCKS is a general-purpose TCP relay, so unlike an HTTP proxy it is designed from the start to carry arbitrary protocols — usually the smoother option for SSH. The version matters: SOCKS4 supports only a username with no password, while SOCKS5 supports full login/password authentication as well as IPv6 and remote DNS resolution. Note this is the inverse of dynamic port forwarding: here a SOCKS proxy is used to reach the SSH server, rather than SSH providing a SOCKS proxy.

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Swift


func chilkatTest() {
    var success: Bool = false

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  Demonstrates connecting to an SSH server through a SOCKS4 or SOCKS5 proxy.

    let ssh = CkoSsh()!

    //  Set the SOCKS proxy properties before connecting.  The hostname may be a domain name or an
    //  IP address.
    ssh.socksHostname = "socks.example.com"
    ssh.socksPort = 1080
    ssh.socksUsername = "mySocksLogin"
    ssh.socksPassword = "mySocksPassword"

    //  Set the version to match the proxy server: 4 or 5.
    //  Note: SOCKS4 supports only a username, with no password.  SOCKS5 supports full
    //  login/password authentication.
    ssh.socksVersion = 5

    var hostname: String? = "ssh.example.com"
    var port: Int = 22
    success = ssh.connect(hostname: hostname, port: port)
    if success == false {
        print("\(ssh.lastErrorText!)")
        return
    }

    print("Connected to the SSH server through the SOCKS proxy.")

    //  Normally you would not hard-code the password in source.  You should instead obtain it
    //  from an interactive prompt, environment variable, or a secrets vault.
    var password: String? = "mySshPassword"

    success = ssh.authenticatePw(login: "mySshLogin", password: password)
    if success == false {
        print("\(ssh.lastErrorText!)")
        return
    }

    //  ... use the SSH connection normally ...

    ssh.disconnect()

}