Are there .NET implementation of TLS 1.2?
Since I just discovered that RFC 5425 requires TLS 1.2 to be used, and that .NET doesn't yet support it, I wonder if there are any implementation, possibly open source, of TLS 1.2 protocol, as defined in RFC 5246.
Answer
Yes, though you have to turn on TLS 1.2 manually at System.Net.ServicePointManager.SecurityProtocol
System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12 | SecurityProtocolType.Tls11 | SecurityProtocolType.Tls; // comparable to modern browsers
var response = WebRequest.Create("https://www.howsmyssl.com/").GetResponse();
var body = new StreamReader(response.GetResponseStream()).ReadToEnd();
Your client is using TLS 1.2, the most modern version of the encryption protocol
Out the box, WebRequest will use TLS 1.0 or SSL 3.
Your client is using TLS 1.0, which is very old, possibly susceptible to the BEAST attack, and doesn't have the best cipher suites available on it. Additions like AES-GCM, and SHA256 to replace MD5-SHA-1 are unavailable to a TLS 1.0 client as well as many more modern cipher suites.