Does TLS 1.2 support depend only on the version of the .NET framework?

Question

I want to globally enforce using TLS 1.2 in my WPF application in the following way:

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

From .NET 4.5 TLS 1.2 protocol is supported for secure communication over https. My question is that will this always work if I ship the .NET 4.5 along side with my application. Does it depends on the OS version?

Answer 1

TLS is termintated in Windows by a component called SChannel. The supported ciphers are dependent on the version of SChannel, which is dependent on the OS, NOT on the .Net version. Windows XP for instance, only supports up to TLS 1.0

This means that your host PC needs to be at least Windows 7 if you want to support TLS 1.2

Details can be found here: http://blogs.msdn.com/b/kaushal/archive/2011/10/02/support-for-ssl-tls-protocols-on-windows.aspx