使用SOAP HTTPS和Duplex进行WCF绑定

Question

I've found myself in need of finding a WCF Binding that uses HTTPS/SOAP and must be duplex. I was programmatically using NetTcpBinding before but the binding now has to be HTTPS/SOAP. I did some research and it seems like it's not possible without creating your own CustomBinding.

However I'm sort of at a lost in what to do (not very familiar with bindings and the setup). I can't seem to get correct binding elements for what I need:

    public class CustomHttpsBinding : CustomBinding
    {
        public CustomHttpsBinding() 
        {
        }


        public override BindingElementCollection CreateBindingElements()
        {
            ReliableSessionBindingElement https = new ReliableSessionBindingElement();

            SecurityBindingElement security = SecurityBindingElement.CreateCertificateOverTransportBindingElement();

            CompositeDuplexBindingElement duplex = new CompositeDuplexBindingElement();

            SslStreamSecurityBindingElement ssl = new SslStreamSecurityBindingElement();

            MessageEncodingBindingElement encoding = new GZipMessageEncodingBindingElement((MessageEncodingBindingElement)  new BinaryMessageEncodingBindingElement());

            HttpsTransportBindingElement transport = new HttpsTransportBindingElement();

            return new BindingElementCollection(new BindingElement[] { https, security, duplex, ssl, encoding, transport });

        }

It gives me an invalid operation exception when checking soap over secure transport requirements saying my contract is configured with an authentication mode that requires integrity and confidentiality. However the transport cannot provide integrity and confidentiality.

Seems like my HttpsTransportBindingElement is not correct? I'm not sure.

Thanks

edit:

I did manage to get WSDualHttpBinding to work at one point, but it seems like HTTPS is not possible with it (as well as others on the internet which say it shouldn't even be used)

Answer 1

HTTP isn't duplex protocol - its request / response - that's why wsDualHttpBinding uses two connections - one in each direction. Silverlight achieves duplex over HTTP by polling for messages from the client under the covers

NetTcpBinding uses TCP which can quite happily be duplex

If you can wait until 4.5 is released later this year this has the NetHttpBinding which does duplex using the WebSocket protocol