(Swift 3,4,5...) TCP or TLS over Multiple Hop SSH to Remote Server

Demonstrates how to use the Chilkat Socket API to connect to a remote server (using TCP or TLS) tunneled through mulitple-hop SSH. The scheme looks like this:

Application => ServerSSH1 => ServerSSH2 => DestinationServer

The ConnectThroughSsh and UseSsh methods are added in Chilkat version 9.5.0.55 to accomplish this task.

Chilkat Downloads for the Swift Programming Language MAC OS X (Cocoa) Objective-C/Swift Libs iOS Objective-C/Swift Libs

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

    let ssh1 = CkoSsh()!

    // Connect directly to the 1st SSH server.
    var success: Bool = ssh1.connect("serverssh1.com", port: 22)
    if success != true {
        print("\(ssh1.lastErrorText!)")
        return
    }

    // Authenticate using login/password:
    success = ssh1.authenticatePw("ssh1Login", password: "ssh1Password")
    if success != true {
        print("\(ssh1.lastErrorText!)")
        return
    }

    // Connect through the 1st SSH connection to reach a 2nd SSH server.
    // Note: Any number of SSH connections may be simultaneously tunneled through a single
    // existing SSH connection.
    let ssh2 = CkoSsh()!
    success = ssh2.connectThroughSsh(ssh1, hostname: "serverssh2.com", port: 22)
    if success != true {
        print("\(ssh2.lastErrorText!)")
        return
    }

    // Authenticate with ssh2...
    success = ssh2.authenticatePw("ssh2Login", password: "ssh2Password")
    if success != true {
        print("\(ssh2.lastErrorText!)")
        return
    }

    let socket = CkoSocket()!

    // Tell the socket object to connect to our destination server though the ssh2 tunnel (which itself is routed through ssh1).
    // The connection looks like this:  ApplicationSocket(TLS) => ServerSSH1 => ServerSSH2 => DestinationServer
    success = socket.use(ssh2)
    if success != true {
        print("\(socket.lastErrorText!)")
        return
    }

    // Connect using TLS to www.chilkatsoft.com
    // We could also tunnel a bare TCP connection by specifying port 80 with useTls = false.
    var useTls: Bool = true
    var maxWaitMillisec: Int = 20000
    success = socket.connect("www.chilkatsoft.com", port: 443, ssl: useTls, maxWaitMs: maxWaitMillisec)
    if success != true {
        print("\(socket.lastErrorText!)")
        return
    }

    // Once the multiple hop SSH tunneled connection is setup,  the socket programming
    // is identical to the normal case where we have a direct connection.

    // Tell the socket object that all text is to be sent in the utf-8 encoding,
    // and the text received is assumed to be utf-8.
    socket.stringCharset = "utf-8"

    // Send an HTTP HEAD request:
    success = socket.send("HEAD / HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n")
    if success != true {
        print("\(socket.lastErrorText!)")
        return
    }

    // Wait a maximum of 4 seconds while no data is forthcoming:
    socket.maxReadIdleMs = 4000

    // Get the 1st response line, which should be "HTTP/1.1 200 OK"
    var responseStatusLine: String? = socket.receiveToCRLF()
    if socket.lastMethodSuccess != true {
        print("\(socket.lastErrorText!)")
        return
    }

    print("StatusLine: \(responseStatusLine!)")

    // Now get the 1st line of the response header:
    var responseHeaderLine: String? = socket.receiveToCRLF()
    if socket.lastMethodSuccess != true {
        print("\(socket.lastErrorText!)")
        return
    }

    print("HeaderLine: \(responseHeaderLine!)")

    // Now read the remainder of the response header by reading until a double CRLF is seen:
    var remainderOfHeader: String? = socket.receive(untilMatch: "\r\n\r\n")
    if socket.lastMethodSuccess != true {
        print("\(socket.lastErrorText!)")
        return
    }

    print("Remainder: \(remainderOfHeader!)")

    // Close the connection with the server.  This closes the tunnel through ssh2.
    // Wait a max of 20 seconds (20000 millsec)
    success = socket.close(20000)

    // Close the connection with ssh2.  (This closes the the tunnel through ssh1.)
    // The connection with ssh1 is still alive, and may be used for more connections.
    ssh2.disconnect()

    ssh1.disconnect()

}