ASP.NET - consume web service - https only - how?

I have web services built with ASP.NET and ASP.NET clients consuming them. When consuming the webservices, how would I to force the clients to use https?

I don't want to f开发者_运维百科orce the whole site to use https by turning on require SSL in IIS.

Can I use the IIS7 URL rewrite module to re-route http requests to https?

No, you cannot use URL rewriting to change the protocol.

Instead, you could just implant a check in your web service and throw an exception if the protocol is HTTP.

Any chance you can add your webservices to a virtual directory and just force the virtual directory to use SSL? Along with checking inside the webservice calls as Fyodor suggest, you could add a check in Application_BeginRequest in your global.asax, although it's not very tidy:

void Application_BeginRequest(object sender, EventArgs e)
{
     if (!Request.IsSecureConnection && Request.Url.ToString().Contains(".asmx"))
     {
        string secureUrl = Request.Url.ToString().Replace("http:", "https:");
        Response.Redirect(secureUrl);
     }
}