DataFlex

SSH Through an HTTP Proxy

Demonstrates connecting to an SSH server through an HTTP proxy, using the HTTP/1.1 CONNECT method. Set HttpProxyHostname and HttpProxyPort before calling Connect.

Background: CONNECT asks the proxy to open a raw TCP tunnel rather than to fetch a page, which is how non-HTTP protocols traverse an HTTP proxy. The important caveat is that the proxy must be configured to permit it: many proxies allow CONNECT only to port 443, in which case an SSH connection on port 22 is refused no matter how the client is configured. Typical proxy ports are 3128 and 8080.

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Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoSsh
    String sHostname
    Integer iPort
    String sPassword
    String sTemp1

    Move False To iSuccess

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

    //  Demonstrates connecting to an SSH server through an HTTP proxy, using the HTTP/1.1 CONNECT
    //  method.

    Get Create (RefClass(cComChilkatSsh)) To hoSsh
    If (Not(IsComObjectCreated(hoSsh))) Begin
        Send CreateComObject of hoSsh
    End

    //  Set the proxy hostname (or IP address) and port before connecting.  Typical HTTP proxy ports
    //  are 3128 and 8080.
    Set ComHttpProxyHostname Of hoSsh To "proxy.example.com"
    Set ComHttpProxyPort Of hoSsh To 3128

    //  Important: the HTTP proxy must allow non-HTTP traffic to pass through the CONNECT tunnel,
    //  otherwise this cannot work.

    Move "ssh.example.com" To sHostname
    Move 22 To iPort
    Get ComConnect Of hoSsh sHostname iPort To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Connected to the SSH server through the HTTP proxy."

    //  Normally you would not hard-code the password in source.  You should instead obtain it
    //  from an interactive prompt, environment variable, or a secrets vault.
    Move "mySshPassword" To sPassword

    Get ComAuthenticatePw Of hoSsh "mySshLogin" sPassword To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoSsh To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  ... use the SSH connection normally ...

    Send ComDisconnect To hoSsh


End_Procedure