DataFlex

TCP or TLS over Multiple Hop SSH to Remote Server

See more Socket/SSL/TLS Examples

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.

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Variant vSsh1
    Handle hoSsh1
    Variant vSsh2
    Handle hoSsh2
    Handle hoSocket
    Boolean iUseTls
    Integer iMaxWaitMillisec
    String sResponseStatusLine
    String sResponseHeaderLine
    String sRemainderOfHeader
    String sTemp1
    Boolean bTemp1

    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(cComChilkatSsh)) To hoSsh1
    If (Not(IsComObjectCreated(hoSsh1))) Begin
        Send CreateComObject of hoSsh1
    End

    // Connect directly to the 1st SSH server.
    Get ComConnect Of hoSsh1 "serverssh1.com" 22 To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoSsh1 To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Authenticate using login/password:
    Get ComAuthenticatePw Of hoSsh1 "ssh1Login" "ssh1Password" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoSsh1 To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // 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.
    Get Create (RefClass(cComChilkatSsh)) To hoSsh2
    If (Not(IsComObjectCreated(hoSsh2))) Begin
        Send CreateComObject of hoSsh2
    End
    Get pvComObject of hoSsh1 to vSsh1
    Get ComConnectThroughSsh Of hoSsh2 vSsh1 "serverssh2.com" 22 To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoSsh2 To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Authenticate with ssh2...
    Get ComAuthenticatePw Of hoSsh2 "ssh2Login" "ssh2Password" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoSsh2 To sTemp1
        Showln sTemp1
        Procedure_Return
    End

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

    // 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
    Get pvComObject of hoSsh2 to vSsh2
    Get ComUseSsh Of hoSocket vSsh2 To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Connect using TLS to www.chilkatsoft.com
    // We could also tunnel a bare TCP connection by specifying port 80 with useTls = False.
    Move True To iUseTls
    Move 20000 To iMaxWaitMillisec
    Get ComConnect Of hoSocket "www.chilkatsoft.com" 443 iUseTls iMaxWaitMillisec To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // 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.
    Set ComStringCharset Of hoSocket To "utf-8"

    // Send an HTTP HEAD request:
    Get ComSendString Of hoSocket "HEAD / HTTP/1.1" + (character(13)) + (character(10)) + "Host: www.chilkatsoft.com" + (character(13)) + (character(10)) + (character(13)) + (character(10)) To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Wait a maximum of 4 seconds while no data is forthcoming:
    Set ComMaxReadIdleMs Of hoSocket To 4000

    // Get the 1st response line, which should be "HTTP/1.1 200 OK"
    Get ComReceiveToCRLF Of hoSocket To sResponseStatusLine
    Get ComLastMethodSuccess Of hoSocket To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "StatusLine: " sResponseStatusLine

    // Now get the 1st line of the response header:
    Get ComReceiveToCRLF Of hoSocket To sResponseHeaderLine
    Get ComLastMethodSuccess Of hoSocket To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "HeaderLine: " sResponseHeaderLine

    // Now read the remainder of the response header by reading until a double CRLF is seen:
    Get ComReceiveUntilMatch Of hoSocket (character(13)) + (character(10)) + (character(13)) + (character(10)) To sRemainderOfHeader
    Get ComLastMethodSuccess Of hoSocket To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoSocket To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Remainder: " sRemainderOfHeader

    // Close the connection with the server.  This closes the tunnel through ssh2.
    // Wait a max of 20 seconds (20000 millsec)
    Get ComClose Of hoSocket 20000 To iSuccess

    // 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.
    Send ComDisconnect To hoSsh2

    Send ComDisconnect To hoSsh1


End_Procedure