如何获得防伪标记

Question

您好我需要测试下载链接，我需要登录，当我尝试使用以下代码登录时，我会重定向回错误页面，因为我没有防伪令牌，你能告诉我吗？如何获得防伪标记，我对此事先感谢新手

//Make a post to LoginTest page
HttpWebRequest request = WebRequest.Create(loginUrlwith the login credential ) as HttpWebRequest;
request.Method = "HEAD";
HttpWebResponse response = request.GetResponse() as HttpWebResponse;

HttpWebRequest request2 = WebRequest.Create(downloadurl) as HttpWebRequest;
request2.CookieContainer = new CookieContainer();
request2.CookieContainer.Add(response.Cookies);
HttpWebResponse response2 = request2.GetResponse() as HttpWebResponse;