Question

I have an HttpHandler mapped to aspnet_isapi.dll to perform a custom authentication check on static files (.pdf files) using IIS 7.5 in Classic mode:

void IHttpHandler.ProcessRequest(HttpContext context)
{
  if(!User.IsMember) {
    Response.Redirect("~/Login.aspx?m=1");
   }
  else {
     //serve static content
   }
}

The above code works fine, except for the else statement logic. In the else statement, I simply want to allow the StaticFileHandler to process the request, but I haven’t been able to sort this out. Any suggestions on how to simply “hand off” the file back to IIS to serve the request as a normal StaticFile request, would be appreciated.

Answer 1

To answer your question directly, you can create a StaticFileHandler and have it process the request:

// Serve static content:
Type type = typeof(HttpApplication).Assembly.GetType("System.Web.StaticFileHandler", true);
IHttpHandler handler = (IHttpHandler)Activator.CreateInstance(type, true);
handler.ProcessRequest(context);

But a better idea might be to create an HTTP module instead of an HTTP handler:

public class AuthenticationModule : IHttpModule
{
    public void Dispose()
    {
    }

    public void Init(HttpApplication application)
    {
        application.AuthorizeRequest += this.Application_AuthorizeRequest;
    }

    private void Application_AuthorizeRequest(object sender, EventArgs e)
    {
        HttpContext context = ((HttpApplication)sender).Context;
        if (!User.IsMember)
            context.Response.Redirect("~/Login.aspx?m=1");      
    }
}