access HttpContext.Current from WCF Web Service

I just started using WCF Services with ASP.NET AJAX. I instantiate my WCF service from Javascript and then pass string variables as arguments to my WCF Service method (with an OperationCont开发者_JAVA技巧ract signature). I then return a .NET object (defined with a DataContract) which is bound to my custom Javascript class. I'm having trouble authenticating based on the user logged into my web session. However, the WCF web service is a completely different service with no context to the HttpContext.Current object. What is the most secure way to get access to that object?

You can get access to HttpContext.Current by enabling AspNetCompatibility, preferably via configuration:

<configuration>
  <system.serviceModel>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true"/>
  </system.serviceModel>
</configuration>

That in turn allows you to get access to the current user: HttpContext.Current.User - which is what you're after, right?

You can even enforce AspNetCompatibility by decorating your service class with an additional attribute:

[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Required)]

(In the System.ServiceModel.Activation namespace.) If that attribute is in place, your service will fail to start unless AspNetCompatibility is enabled!

You do not have a HttpContext by default but you have many of the same objects present in the OperationContext (which is always present) or the WebOperationContext (which is only available for certain bindings.

You can access the OperationContext or WebOperationContext by using the static .Current property like so: WebOperationContext.Current

In case you don't want to change Web.config or you cannot change it:

private string GetClientIPAddress()
        {
            var props = OperationContext.Current.IncomingMessageProperties;
            var endpointProperty = props[RemoteEndpointMessageProperty.Name] as RemoteEndpointMessageProperty;
            if (endpointProperty != null)
            {
                if (endpointProperty.Address == "::1" || String.IsNullOrEmpty(endpointProperty.Address))
                    return "127.0.0.1";

                return endpointProperty.Address;
            }

            return String.Empty;
        }