/**
     * Use SMB2 non-backward compatible negotiation style
     * 
     * Property <tt>jcifs.smb.client.useSMB2Negotiation</tt> (boolean, default false)
     * 
     * @return whether to use non-backward compatible protocol negotiation
     */
    boolean isUseSMB2OnlyNegotiation ();


    /**
     * Enforce secure negotiation
     * 

     * 
     * @param req
     *            The servlet request
     * @param resp
     *            The servlet response
     * @param skipAuthentication
     *            If true the negotiation is only done if it is
     *            initiated by the client (MSIE post requests after successful NTLM SSP
     *            authentication). If false and the user has not been authenticated yet

     * @param skipAuthentication If true the negotiation is only done if it is
     * initiated by the client (MSIE post requests after successful NTLM SSP
     * authentication). If false and the user has not been authenticated yet
     * the client will be forced to send an authentication (server sends
     * HttpServletResponse.SC_UNAUTHORIZED).
     * @return True if the negotiation is complete, otherwise false
     */

            log.debug("Secure negotiation does not apply");
            return;
        }

        Smb2NegotiateResponse nego = (Smb2NegotiateResponse) trans.getNegotiateResponse();
        if ( nego.getSelectedDialect().atLeast(DialectVersion.SMB311) ) {
            // have preauth integrity instead
            log.debug("Secure negotiation does not apply, is SMB3.1");
            return;
        }

            }
            else if ( targ.getResult() != NegTokenTarg.ACCEPT_COMPLETED ) {
                throw new SmbException("SPNEGO negotiation did not complete");
            }
            verifyMechListMIC(targ.getMechanismListMIC());
            this.completed = true;
            return null;
        }

        if ( inputToken == null ) {

/**
 * Access to platform-specific features.
 *
 * ### Session Tickets
 *
 * Supported on Android 2.3+.
 * Supported on JDK 8+ via Conscrypt.
 *
 * ### ALPN (Application Layer Protocol Negotiation)
 *
 * Supported on Android 5.0+.
 *
 * Supported on OpenJDK 8 via the JettyALPN-boot library or Conscrypt.
 *
 * Supported on OpenJDK 9+ via SSLParameters and SSLSocket features.
 *

   * HTTP/2. This is true by default; set to false to disable negotiation and restrict connections
   * to HTTP/1.1.
   */
  var protocolNegotiationEnabled: Boolean = true

  /**
   * The protocols supported by ALPN on incoming HTTPS connections in order of preference. The list
   * must contain [Protocol.HTTP_1_1]. It must not contain null.
   *
   * This list is ignored when [negotiation is disabled][protocolNegotiationEnabled].
   */

    // we should try the next route (if there is one).
    if (e is InterruptedIOException) {
      return e is SocketTimeoutException && !requestSendStarted
    }

    // Look for known client-side or negotiation errors that are unlikely to be fixed by trying
    // again with a different route.
    if (e is SSLHandshakeException) {
      // If the problem was a CertificateException from the X509TrustManager,
      // do not retry.

        if ( this.flags2 == 0 ) {
            this.flags2 = SmbConstants.FLAGS2_LONG_FILENAMES | SmbConstants.FLAGS2_EXTENDED_ATTRIBUTES
                    | ( this.useExtendedSecurity ? SmbConstants.FLAGS2_EXTENDED_SECURITY_NEGOTIATION : 0 )
                    | ( this.signingPreferred ? SmbConstants.FLAGS2_SECURITY_SIGNATURES : 0 )
                    | ( this.useNtStatus ? SmbConstants.FLAGS2_STATUS32 : 0 )

 *  **`COMPATIBLE_TLS` no longer supports SSLv3.** In response to the
    [POODLE](https://googleonlinesecurity.blogspot.ca/2014/10/this-poodle-bites-exploiting-ssl-30.html)
    vulnerability, OkHttp no longer offers SSLv3 when negotiation an
    HTTPS connection. If you continue to need to connect to webservers
    running SSLv3, you must manually configure your own `ConnectionSpec`.