(Swift) WebSocket through SSH Tunnel

This example shows how to establish a WebSocket connection through an SSH tunnel. The WebSocket protocol communications will be encapsulated within an SSH tunnel.

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

    //  --------------------------------------------------
    //  This example borrows the code from the REST through SSH Tunnel example.
    //  We first use the Chilkat Socket object to establish a connection to the WebSocket server through an SSH Tunnel.
    //  Next, the Rest object uses the Socket object for its connection.
    //  Finally, the WebSocket object uses the Rest object for its connection.
    // 
    //  Hopefully the flexibility of this architecture is easy to see.  All of the HTTP functionality of the Rest object,
    //  such as HTTP authentication, custom headers, etc. is available to the WebSocket.  Likewise, all of the advanced functionality
    //  of the Socket object is in turn available to the Rest object.

    //  The high-level steps for accomplishing the task of running the WebSocket protocol through an SSH accomplished as follows:
    //  1) Create the SSH tunnel using Chilkat Socket.
    //  2) Open a port-forwarding channel (to the WebSocket server) within the tunnel.
    //  2) Tell Rest to use the Socket object.
    //  3) Tell WebSocket to use the Rest object.

    let tunnel = CkoSocket()

    var sshHostname: String? = "www.my-ssh-server.com"
    var sshPort: Int = 22

    //  Connect to an SSH server and establish the SSH tunnel:
    var success: Bool = tunnel.SshOpenTunnel(sshHostname, sshPort: sshPort)
    if success != true {
        print("\(tunnel.LastErrorText)")
        return
    }

    //  Authenticate with the SSH server via a login/password
    //  or with a public key.
    //  This example demonstrates SSH password authentication.
    success = tunnel.SshAuthenticatePw("mySshLogin", sshPassword: "mySshPassword")
    if success != true {
        print("\(tunnel.LastErrorText)")
        return
    }

    //   OK, the SSH tunnel is setup.  Now open a channel within the tunnel.
    var channel: CkoSocket?

    var bTls: Bool = true
    var port: Int = 443
    var maxWaitMs: Int = 5000

    //  This returns a socket object that is a single channel within the SSH tunnel.
    //  The SSH channel is our logical port-forwarded connection through the SSH tunnel.
    //  Note: This example establishes a TLS connection to the target WebSocket server.
    //  (The TLS protocol will run on the logical channel within the SSH tunnel.)
    //  Your application can just as easily make a non-TLS connection by changing the arguments
    //  passed to SshOpenChannel.
    channel = tunnel.SshOpenChannel("some-websocket-server.com", port: port, ssl: bTls, maxWaitMs: maxWaitMs)
    if tunnel.LastMethodSuccess != true {
        print("\(tunnel.LastErrorText)")
        return
    }

    //  Create a REST object and tell it to use the SSH channel.
    //  This connection is a TLS running on an SSH channel through an SSH tunnel.
    //  In other words, TLS is wrapped within the SSH tunnel.
    let rest = CkoRest()
    success = rest.UseConnection(channel, autoReconnect: false)
    if success != true {
        print("\(rest.LastErrorText)")
        channel = nil
        return
    }

    //  Finally, tell our WebSocket object to use the Rest object..
    let ws = CkoWebSocket()

    //  Tell the WebSocket to use this connection.
    success = ws.UseConnection(rest)
    if success != true {
        print("\(ws.LastErrorText)")
        return
    }

    //  Add the standard WebSocket open handshake headers that will be needed.
    //  (This adds the required HTTP request headers to the rest object.)
    ws.AddClientHeaders()

    //  Add any additional headers that might be desired.
    //  Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
    rest.AddHeader("Sec-WebSocket-Protocol", value: "x-some-websocket-subprotocol")
    rest.AddHeader("Origin", value: "http://some-websocket-server.com")

    //  Do the open handshake.
    var responseBody: String? = rest.FullRequestNoBody("GET", uriPath: "/something")
    if rest.LastMethodSuccess != true {
        print("\(rest.LastErrorText)")
        return
    }

    //  If successful, the HTTP response status code should be 101,
    //  and the response body will be empty. (If it failed, we'll have a look
    //  at the response body..)
    var statusCode: Int = rest.ResponseStatusCode.integerValue
    print("Response status code: \(statusCode)")

    if statusCode != 101 {
        print("\(responseBody!)")
        print("-- Failed because of unexpected response status code.")
        return
    }

    //  We have the expected 101 response, so let's now validate the
    //  contents of the response, such as the value sent by the server in the
    //  Sec-WebSocket-Accept header.
    success = ws.ValidateServerHandshake()
    if success != true {
        print("\(ws.LastErrorText)")
        return
    }

    print("WebSocket connection successful.")

    //  The application may now begin sending and receiving frames on the WebSocket connection.
    //  (At this point, we're done with the rest object...)

}