我有一个减轻MVC应用程序中主机头注入的任务。除此之外，我想通过创建一个HTTP模块来实现白名单检查。
到目前为止，我正在使用这样的东西：
web.config条目：

<system.webServer>
    <modules>
      <add name="TestHttpModule" type="MVC5TestApp.MyHttpModule, MVC5TestApp" />
    </modules>
  </system.webServer>

字符串
HTTP模块类：

public class MyHttpModule: IHttpModule 
{
    public MyHttpModule() {}
    public void Init(HttpApplication application) 
    {
        application.BeginRequest += new EventHandler(this.context_BeginRequest);
        application.EndRequest += new EventHandler(this.context_EndRequest);
    }
    public void context_BeginRequest(object sender, EventArgs e) 
    {
        CheckForHostHeaderInjection();
    }
    public void context_EndRequest(object sender, EventArgs e) 
    {
        // some code
    }
    public void Dispose() {}
    private void CheckForHostHeaderInjection()
    {
        // Currently, I am just comparing the following two ServerVariables.
        // I will add a method to compare "HTTP_HOST" value against a whitelist later.
        var httpHost = HttpContext.Current.Request.ServerVariables["HTTP_HOST"];
        var serverName = HttpContext.Current.Request.ServerVariables["SERVER_NAME"];
        if (!string.Equals(httpHost, serverName))
        {
            // What do I do in order to send back to the client a 400 Bad Request??
        }
    }
}

型