问用用户证书签名的HTTPS连接-不同计算机上的意外行为

EN

    static public string PostLPDA(string fileName, string URL, string certificateFile)
    {
        X509Certificate cert = new X509Certificate(certificateFile); // importing certificate from file <===== 1

        StreamReader sr = new StreamReader(fileName); 
        string postString = string.Format("Query={0}", sr.ReadToEnd());  // preparing data to send

        const string contentType = "application/x-www-form-urlencoded";
        System.Net.ServicePointManager.Expect100Continue = false;

        CookieContainer cookies = new CookieContainer();
        HttpWebRequest webRequest = WebRequest.Create(URL) as HttpWebRequest;
        webRequest.Method = "POST";
        webRequest.ContentType = contentType;
        webRequest.CookieContainer = cookies;
        webRequest.ContentLength = postString.Length;
        webRequest.UserAgent = "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1";
        webRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        webRequest.ClientCertificates.Add(cert); //adding certificate 
        System.Net.ServicePointManager.ServerCertificateValidationCallback = 
            ((sender, certificate, chain, sslPolicyErrors) => true); // ignore untrusted site error <===== 2

        StreamWriter requestWriter = new StreamWriter(webRequest.GetRequestStream()); // <===== 3
        requestWriter.Write(postString);
        requestWriter.Close();

        StreamReader responseReader = new StreamReader(webRequest.GetResponse().GetResponseStream());
        string responseData = responseReader.ReadToEnd();

        responseReader.Close();
        webRequest.GetResponse().Close();
        return responseData;
    }