(Go) SSH Tunnel (Port Forwarding via direct-tcpip channel)

Demonstrates how to create an SSH tunnel to a remote hostname:port via a direct-tcpip channel.

Chilkat Go Downloads Go Package for Windows, MacOS, Linux, Alpine Linux, Solaris

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

    ssh := chilkat.NewSsh()

    // Connect to an SSH server:
    var hostname string
    var port int

    // Hostname may be an IP address or hostname:
    hostname = "192.168.1.117"
    port = 22

    success := ssh.Connect(hostname,port)
    if success != true {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    // Wait a max of 5 seconds when reading responses..
    ssh.SetIdleTimeoutMs(5000)

    // Authenticate using login/password:
    success = ssh.AuthenticatePw("chilkat","myPassword")
    if success != true {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    // Open a direct-tcpip channel.  We want the SSH server to connect
    // to www.chilkatsoft.com, port 80 (i.e. the web server).
    // Data sent through the SSH tunnel is forwarded to the remote
    // host:port.  (Note: The remote host:port does not need to be 
    // a web server.  It can be anything.  It can be your own
    // customer application server that listens on a port, or any
    // other type of server.)
    // When we read from the SSH channel, we'll be reading data
    // sent from the remote host:port (i.e. the web server in this
    // example).
    var channelNum int
    channelNum = ssh.OpenDirectTcpIpChannel("www.chilkatsoft.com",80)
    if channelNum < 0 {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    // Build a simple HTTP GET request for http://www.chilkatsoft.com/xyz.html
    httpReq := "GET /xyz123.html HTTP/1.1\r\nHost: www.chilkatsoft.com\r\n\r\n"

    // Send the HTTP request:
    success = ssh.ChannelSendString(channelNum,httpReq,"ansi")
    if success != true {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    // Get the HTTP response.
    // First read the HTTP response header which ends with a double CRLF.
    // Calling ChannelReceiveUntilMatch will receive until match string is seen,
    // or until a timeout occurs (IdleTimeoutMs property).  ChannelReceiveUntilMatch
    // may read beyond the match string, but it will stop reading as soon as the match
    // string is seen.
    caseSensitive := false
    matchStr := "\r\n\r\n"
    success = ssh.ChannelReceiveUntilMatch(channelNum,matchStr,"ansi",caseSensitive)
    if success != true {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    // Extract the HTTP header from the receive buffer.
    // (GetReceiveTextS extracts up to and including the match string from the receive buffer)
    var responseHeader *string = new(string)
    responseHeader = *ssh.GetReceivedTextS(channelNum,matchStr,"ansi")
    fmt.Println("---- HTTP Response Header ----")
    fmt.Println(*responseHeader)

    // Now get the body of the HTTP response (this is the HTML content
    // of http://www.chilkatsoft.com/xyz.html
    // It's possible we've already received the entire HTTP response in the
    // call to ChannelReceiveUntilMatch.  Therefore, we'll poll for any remaining data
    // and wait a max of .2 seconds.
    var numBytesRead int
    pollTimeoutMs := 200
    numBytesRead = ssh.ChannelPoll(channelNum,pollTimeoutMs)
    // We're not checking for an error here.
    // A return value of -2 means that no data was available and the poll simply timed out (not an error)
    // A return value of -1 indicates an error.
    // A return value greater than 0 indicates that additional data was received.

    fmt.Println("---- HTML BODY ----")

    // Extract the remainder of the accumulated data in the internal receive buffer.
    // This should be our HTML body:
    var htmlBody *string = new(string)
    htmlBody = *ssh.GetReceivedText(channelNum,"ansi")
    fmt.Println(*htmlBody)

    // Close the channel:
    success = ssh.ChannelSendClose(channelNum)
    if success != true {
        fmt.Println(ssh.LastErrorText())
        ssh.DisposeSsh()
        return
    }

    // Disconnect
    ssh.Disconnect()

    ssh.DisposeSsh()