Node.js

FTP through SSH Tunnel with Dynamic Port Forwarding

See more FTP Examples

Demonstrates how to start a background thread that runs a portable SSH tunnel w/ dynamic port forwarding that the foreground thread can be used for establishing FTP sessions through an SSH tunnel.

Note: Some developers may be accustomed to starting an stunnel.exe proxy from https://www.stunnel.org. The stunnel.exe is not necessary here. Chilkat's background thread fulfills the task of what the external stunnel.exe does. Therefore, your application is self-contained, meaning that it can run anywhere because the SSH tunnel proxy is built-in.

Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

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

    success = false;

    var tunnel = new chilkat.SshTunnel();

    var sshHostname = "sftp.example.com";
    var sshPort = 22;

    //  Connect to an SSH server and establish the SSH tunnel:
    success = tunnel.Connect(sshHostname,sshPort);
    if (success !== true) {
        console.log(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.AuthenticatePw("mySshLogin","mySshPassword");
    if (success !== true) {
        console.log(tunnel.LastErrorText);
        return;
    }

    //  Indicate that the background SSH tunnel thread will behave as a SOCKS proxy server
    //  with dynamic port forwarding:
    tunnel.DynamicPortForwarding = true;

    //  We may optionally require that connecting clients authenticate with our SOCKS proxy server.
    //  To do this, set an inbound username/password.  Any connecting clients would be required to 
    //  use SOCKS5 with the correct username/password.
    //  If no inbound username/password is set, then our SOCKS proxy server will accept both
    //  SOCKS4 and SOCKS5 unauthenticated connections.

    tunnel.InboundSocksUsername = "chilkat123";
    tunnel.InboundSocksPassword = "password123";

    //  Start the listen/accept thread to begin accepting SOCKS proxy client connections.
    //  Listen on port 1080.
    success = tunnel.BeginAccepting(1080);
    if (success !== true) {
        console.log(tunnel.LastErrorText);
        return;
    }

    //  Now that a background thread is running a SOCKS proxy server that forwards connections
    //  through an SSH tunnel, it is possible to use any Chilkat implemented protocol that is SOCKS capable,
    //  such as HTTP, POP3, SMTP, IMAP, FTP, etc.  The protocol may use SSL/TLS because the SSL/TLS
    //  will be passed through the SSH tunnel to the end-destination.  Also, any number of simultaneous
    //  connections may be routed through the SSH tunnel.

    var ftp = new chilkat.Ftp2();

    //  Indicate that the HTTP object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
    ftp.SocksHostname = "localhost";
    //  The SocksPort must equal the port passed to BeginAccepting above.
    ftp.SocksPort = 1080;
    ftp.SocksVersion = 5;
    //  The SOCKS5 login/password set here must equal the InboundSocksUsername/Password set above.
    ftp.SocksUsername = "chilkat123";
    ftp.SocksPassword = "password123";

    //  This is the actual FTP server domain or IP address, and the login/password for the user account on the destination FTP server.
    ftp.Hostname = "ftp.someFtpServer.com";
    ftp.Username = "myLogin";
    ftp.Password = "myPassword";
    ftp.AuthTls = true;

    //  Connect and login (via the SSH tunnel) to the FTP server.
    success = ftp.Connect();
    if (success !== true) {
        console.log(ftp.LastErrorText);
        return;
    }

    //  Change to the remote directory where the file is located.
    //  This step is only necessary if the file is not in the root directory
    //  for the FTP account.
    success = ftp.ChangeRemoteDir("junk");
    if (success !== true) {
        console.log(ftp.LastErrorText);
        return;
    }

    var localFilename = "c:/temp/hamlet.xml";
    var remoteFilename = "hamlet.xml";

    //  Download a file.  (the data connection is also automatically established through the 
    //  SSH tunnel using dynamic port forwarding..)
    success = ftp.GetFile(remoteFilename,localFilename);
    if (success !== true) {
        console.log(ftp.LastErrorText);
        return;
    }

    //  The disconnect is disconnecting with the FTP server and closes the SSH tunnel.
    //  The background tunnel thread is still running, and may be used for subsequent FTP connections,
    //  or even connections for any other purpose, such as HTTP, IMAP, SMTP, POP3, etc.
    success = ftp.Disconnect();

    //  When the app is finished with the tunnel, it can cleanup..

    //  Stop the background listen/accept thread:
    var waitForThreadExit = true;
    success = tunnel.StopAccepting(waitForThreadExit);
    if (success !== true) {
        console.log(tunnel.LastErrorText);
        return;
    }

    //  Close the SSH tunnel (would also kick any remaining connected clients).
    success = tunnel.CloseTunnel(waitForThreadExit);
    if (success !== true) {
        console.log(tunnel.LastErrorText);
        return;
    }


}

chilkatExample();