Swift

FTP through SSH Tunnel

See more FTP Examples

Demonstrates how to FTP through an SSH tunnel.

The Chilkat SSH tunnel object is used to create a portable SSH tunnel w/ dynamic port forwarding on a background thread that the foreground thread can use for establishing connections through an SSH tunnel.

Swift

func chilkatTest() {
    var success: Bool = false

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

    success = false

    let tunnel = CkoSshTunnel()!

    var sshHostname: String? = "sftp.example.com"
    var sshPort: Int = 22

    // Connect to an SSH server and establish the SSH tunnel:
    success = tunnel.connect(hostname: sshHostname, port: 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.authenticatePw(login: "mySshLogin", password: "mySshPassword")
    if success != true {
        print("\(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(listenPort: 1080)
    if success != true {
        print("\(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 Socket, 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.

    // Let's do an FTP upload through the SSH tunnel.  Both the control and data connections 
    // go through the tunnel.
    let ftp = CkoFtp2()!

    ftp.hostname = "ftp.example.com"
    ftp.username = "login"
    ftp.password = "password"

    // Indicate that the FTP2 object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
    ftp.socksHostname = "localhost"
    ftp.socksPort = 1080
    ftp.socksVersion = 5
    ftp.socksUsername = "chilkat123"
    ftp.socksPassword = "password123"

    // Connect to the FTP server
    success = ftp.connectOnly()
    if success != true {
        print("\(ftp.lastErrorText!)")
        return
    }

    // Authenticate with the FTP server.
    success = ftp.loginAfterConnectOnly()
    if success != true {
        print("\(ftp.lastErrorText!)")
        return
    }

    // Change to the remote directory where the file will be uploaded.
    success = ftp.changeRemoteDir(relativeDirPath: "junk")
    if success != true {
        print("\(ftp.lastErrorText!)")
        return
    }

    // Upload a file.
    var localPath: String? = "/temp/hamlet.xml"
    var remoteFilename: String? = "hamlet.xml"

    success = ftp.putFile(localPath: localPath, remoteFilename: remoteFilename)
    if success != true {
        print("\(ftp.lastErrorText!)")
        return
    }

    // This closes the SSH channel within the SSH tunnel,
    // and thus closes the connection with the FTP server.
    success = ftp.disconnect()

    print("File Uploaded!")

    // Stop the background listen/accept thread:
    var waitForThreadExit: Bool = true
    success = tunnel.stopAccepting(waitForThread: waitForThreadExit)
    if success != true {
        print("\(tunnel.lastErrorText!)")
        return
    }

    // Close the SSH tunnel (would also kick any remaining connected clients).
    success = tunnel.closeTunnel(waitForThreads: waitForThreadExit)
    if success != true {
        print("\(tunnel.lastErrorText!)")
        return
    }


}