Is that possible to send HttpWebRequest using TLS1.2 on .NET 4.0 framework

My application connects to Experian server and Experian will soon stop supporting TLS 1.0 and TLS 1.1. All connectivity using HTTPS must use TLS Version 1.2.

I want to do some research on that issue and see sending HttpWebRequest using TLS 1.2 on .NET 4.0 framework works

If it does not, I will probably need to create a webservice on .NET 4.5 and call its methods, if it does, I do not have to anything.

Has anyone already faced with that issue?

Yes, it supports it but you must explicitly set the TLS version on the ServicePointManager. Just have this code run anytime (in same app domain) before you make the call to Experian:

System.Net.ServicePointManager.SecurityProtocol = System.Net.SecurityProtocolType.Tls12

Update

see @iignatov 's answer for what you must do for framework v4.0. My code works with 4.5+

I had to deal with the same problem, while integrating PayPal into a legacy application, and found the following workaround for .NET 4.0 which seems to do the trick:

ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;
ServicePointManager.DefaultConnectionLimit = 9999;

Basically the workaround is to directly assign the port for TLS 1.2.

All credit goes to the commenter at CodeProject.

The VB.NET Translation of iignatov's answer:

ServicePointManager.Expect100Continue = True
ServicePointManager.SecurityProtocol = CType(3072, SecurityProtocolType)
ServicePointManager.DefaultConnectionLimit = 9999

I was solved with this way.

    string url = "https://api.foursquare.com/v2/blablabla...";
    var request = (HttpWebRequest)WebRequest.Create(url);

    ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3 | SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls;
    
    var response = (HttpWebResponse)request.GetResponse();
    var responseString = new StreamReader(response.GetResponseStream()).ReadToEnd();

You can also use this:

ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls | (SecurityProtocolType)768 | (SecurityProtocolType)3072;

Unfortunately no, you can't do this. Tls12 was not added until .netfx 4.5 (see the documentation). Note this also requires Windows Server 2008 R2+ or Windows 7+ to run correctly (notice the Applies To section on Introducing TLS).

FrameWork 4.0 does not support TLS 1.1 or 1.2 But you can fix this problem by downloading Rebex.Http from Nuget manager.

Rebex.Licensing.Key = "..."; //Lisans Number
var creator = new HttpRequestCreator();
creator.Register();
    
WebRequest request = WebRequest.Create("https://www.test.com");
request.Method = "POST";                
request.Headers.Add("utsToken", txtToken.Text);
request.ContentType = "application/json";
request.Method = "POST";
    
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
    string json = "{\"VRG\":\"test\"}";
    
    streamWriter.Write(json);
    streamWriter.Flush();
    streamWriter.Close();
}
    
var httpResponse = (WebResponse)request.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
    var result = streamReader.ReadToEnd();
    txtSonuc.Text += result;
}

ServicePointManager.Expect100Continue = true;
ServicePointManager.SecurityProtocol = (SecurityProtocolType)3072;

that's worked for me on .net 3.5