DataFlex

SSH Tunnel Inside another SSH Tunnel

See more SSH Tunnel Examples

Demonstrates how to create a TCP/IP socket connection through an SSH tunnel that is dynamic port forwarded through another SSH tunnel. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoTunnel
    String sSshHostname
    Integer iSshPort
    Handle hoTunnelB
    Variant vChannel
    Handle hoChannel
    Integer iMaxWaitMs
    Boolean iUseTls
    Boolean iBigEndian
    Handle hoDt
    Boolean iBLocalTime
    Boolean iWaitForThreadExit
    String sTemp1
    Integer iTemp1

    Move False To iSuccess

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

    Get Create (RefClass(cComChilkatSshTunnel)) To hoTunnel
    If (Not(IsComObjectCreated(hoTunnel))) Begin
        Send CreateComObject of hoTunnel
    End

    Move "www.ssh-serverA.com" To sSshHostname
    Move 22 To iSshPort

    // Connect to an SSH server and establish the SSH tunnel:
    Get ComConnect Of hoTunnel sSshHostname iSshPort To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnel To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Authenticate with the SSH server via a login/password
    // or with a public key.  
    // This example demonstrates SSH password authentication.
    Get ComAuthenticatePw Of hoTunnel "mySshLogin" "mySshPassword" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnel To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Indicate that the background SSH tunnel thread will behave as a SOCKS proxy server
    // with dynamic port forwarding:
    Set ComDynamicPortForwarding Of hoTunnel To 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.

    Set ComInboundSocksUsername Of hoTunnel To "chilkat123"
    Set ComInboundSocksPassword Of hoTunnel To "password123"

    // Start the listen/accept thread to begin accepting SOCKS proxy client connections.
    // Listen on port 1080.
    Get ComBeginAccepting Of hoTunnel 1080 To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnel To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // 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, Socket, 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.

    Get Create (RefClass(cComChilkatSocket)) To hoTunnelB
    If (Not(IsComObjectCreated(hoTunnelB))) Begin
        Send CreateComObject of hoTunnelB
    End

    // Indicate that the socket object is to use our portable SOCKS proxy/SSH tunnel running in our background thread.
    Set ComSocksHostname Of hoTunnelB To "localhost"
    Set ComSocksPort Of hoTunnelB To 1080
    Set ComSocksVersion Of hoTunnelB To 5
    Set ComSocksUsername Of hoTunnelB To "chilkat123"
    Set ComSocksPassword Of hoTunnelB To "password123"

    // Open a new SSH tunnel through the existing tunnel (via what we treat as a SOCKS5 proxy,
    // but it is actually a dynamic port-forwarded SSH tunnel).
    Get ComSshOpenTunnel Of hoTunnelB "www.ssh-serverB.com" 22 To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnelB To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Authenticate with ssh-serverB.com
    Get ComSshAuthenticatePw Of hoTunnelB "uname" "pwd" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnelB To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // OK, the SSH tunnel (within a tunnel) is setup.  Now open a channel within the tunnel.
    // Once the channel is obtained, the Socket API may
    // be used exactly the same as usual, except all communications
    // are sent through the channel in the SSH tunnel.
    // Any number of channels may be created from the same SSH tunnel.
    // Multiple channels may coexist at the same time.

    // Connect to an NIST time server and read the current date/time
    Get Create (RefClass(cComChilkatSocket)) To hoChannel
    If (Not(IsComObjectCreated(hoChannel))) Begin
        Send CreateComObject of hoChannel
    End
    Move 4000 To iMaxWaitMs
    Move False To iUseTls
    Get pvComObject of hoChannel to vChannel
    Get ComSshNewChannel Of hoTunnelB "time-c.nist.gov" 37 iUseTls iMaxWaitMs vChannel To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnelB To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // The time server will send a big-endian 32-bit integer representing
    // the number of seconds since since 00:00 (midnight) 1 January 1900 GMT.
    // The ReceiveInt32 method will receive a 4-byte integer, but returns
    // True or False to indicate success.  If successful, the integer
    // is obtained via the ReceivedInt property.
    Move True To iBigEndian
    Get ComReceiveInt32 Of hoChannel iBigEndian To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoChannel To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComCkDateTime)) To hoDt
    If (Not(IsComObjectCreated(hoDt))) Begin
        Send CreateComObject of hoDt
    End
    Get ComReceivedInt Of hoChannel To iTemp1
    Get ComSetFromNtpTime Of hoDt iTemp1 To iSuccess

    // Show the current local date/time
    Move True To iBLocalTime
    Get ComGetAsRfc822 Of hoDt iBLocalTime To sTemp1
    Showln "Current local date/time: " sTemp1

    // Close the SSH channel.
    Get ComClose Of hoChannel iMaxWaitMs To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoChannel To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Stop the background listen/accept thread:
    Move True To iWaitForThreadExit
    Get ComStopAccepting Of hoTunnel iWaitForThreadExit To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnel To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Close the SSH tunnel (would also kick any remaining connected clients).
    Get ComCloseTunnel Of hoTunnel iWaitForThreadExit To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoTunnel To sTemp1
        Showln sTemp1
        Procedure_Return
    End



End_Procedure