SSL Certificate Exception everytime a connection is established

Question

Hello guys!
I am trying to authenticate a website running SharePoint 2010. But everytime a connection is established, an SSL/TLS exception is thrown. The following is the code I am using. Any idea??
The exception is: "The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel."
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using System.Net;
using System.Net.NetworkInformation;
using Windows.Networking.Connectivity;
using System.Net.Http;
using System.Xml.Linq;
using System.Text;
using Windows.Web.Http.Filters;
using Windows.Security.Cryptography.Certificates;
// The Blank Page item template is documented at http://go.microsoft.com/fwlink/?LinkId=234238
namespace TestApp
    /// <summary>
    /// An empty page that can be used on its own or navigated to within a Frame.
    /// </summary>
    public sealed partial class MainPage : Page
        public MainPage()
            this.InitializeComponent();
        private static HttpWebRequest CreateWebRequest(string url, NetworkCredential credentials)
            //Initialize new instance of HttpBaseProtocolFilter, which implements IHttpFilter.  
            string action = "http://schemas.microsoft.com/sharepoint/soap/GetWebCollection";
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Credentials = credentials;
            req.Headers["SOAPAction"] = action;
            req.ContentType = "text/xml;charset=\"utf-8\"";
            req.Accept = "text/xml";
            req.Method = "POST";
            return req;
        static string soapEnvelope = @"<soap:Envelope xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xsd='http://www.w3.org/2001/XMLSchema' xmlns:soap='http://schemas.xmlsoap.org/soap/envelope/'><soap:Body></soap:Body></soap:Envelope>";
        //static string soapEnvelope =
          //         @"<?xml version=""1.0"" encoding=""utf-8""?> <soap:Envelope xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema""
xmlns:soap=""http://schemas.xmlsoap.org/soap/envelope/""> <soap:Body> <Login xmlns=""http://schemas.microsoft.com/sharepoint/soap/""> <username>{0}</username> <password>{1}</password>
</Login> </soap:Body> </soap:Envelope>";
        private static XDocument CreateSoapEnvelope(string content)
            StringBuilder sb = new StringBuilder(soapEnvelope);
            sb.Insert(sb.ToString().IndexOf("</soap:Body>"), content);
            XDocument soapEnvelopeXml = XDocument.Parse(sb.ToString());
            return soapEnvelopeXml;
        private static void InsertSoapEnvelopeIntoWebRequest(XDocument soapEnvelopeXml, HttpWebRequest webRequest)
        webRequest.BeginGetRequestStream((IAsyncResult asynchronousResult) =>
                HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
                Stream postStream = request.EndGetRequestStream(asynchronousResult);
                soapEnvelopeXml.Save(postStream);
                //postStream.Close();
                request.BeginGetResponse(new AsyncCallback(GetResponseCallback), request);
                }, webRequest);
        private static void GetResponseCallback(IAsyncResult asynchronousResult)
            HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
            HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);
            Stream streamResponse = response.GetResponseStream();
            StreamReader streamRead = new StreamReader(streamResponse);
            string responseString = streamRead.ReadToEnd();
            //do whatever with the response 
            //streamResponse.Close();
            //streamRead.Close();
            //response.Close();
        private void Button_Click(object sender, RoutedEventArgs e)
            NetworkCredential credentials = new NetworkCredential("<user>", "<password>", "<domain>");
            HttpWebRequest request = CreateWebRequest("https://the_website_I_am_trying_to_connect_to", credentials);
            XDocument soapEnvelope = CreateSoapEnvelope("<GetWebCollection xmlns=\"http://schemas.microsoft.com/sharepoint/soap/\" />");
            InsertSoapEnvelopeIntoWebRequest(soapEnvelope, request);
                

Answer 1

Hi,
According to your description, my understanding is that when you access a https web service, it occurs the “The underlying connection was closed. Could not establish trust relationship for the SSL/TLS secure channe” error.
To overcome this error, you need to install the certificate that is used by the web service provider in the server that will be calling the web service.
Open Microsoft Management Console (Start --> Run      --> mmc.exe);
Choose File --> Add/Remove Snap-in;
In the Standalone tab, choose Add;
Choose the Certificates snap-in, and click Add;
In the wizard, choose the Computer Account, and then      choose Local Computer. Press Finish to end the wizard;
Close the Add/Remove Snap-in dialog;
Navigate to Certificates (Local Computer)
Choose a store to import:
If you have the Root CA       certificate for the company that issued the certificate, choose Trusted       Root Certification Authorities;
If you have the       certificate for the server itself, choose Other People
Right-click the store and choose All Tasks -->      Import
Follow the wizard and provide the certificate file you      have;
Here are some detailed articles for your reference:
http://www.c-sharpcorner.com/uploadfile/anavijai/could-not-establish-trust-relationship-for-the-ssltls-secure-channel/
http://stackoverflow.com/questions/703272/could-not-establish-trust-relationship-for-ssl-tls-secure-channel-soap
Thanks
Best Regards
Jerry Guo
TechNet Community Support
Hello Jerry,
Thank you very much for your reply.
But what about Windows Phone? I am running the same code on´WP 8.1 as a store app, and returns an exception at the same place: the GetResponseCallBack.
Any workaround? Can I run a code from the app that uses the certificate or at least installs it?
Thanks a lot.