There is a non-global setting at the level of HttpClientHandler
:
var handler = new HttpClientHandler()
{
SslProtocols = SslProtocols.Tls12 | SslProtocols.Tls11 | SslProtocols.Tls
};
var client = new HttpClient(handler);
Thus one enables latest TLS versions.
Note, that the default value SslProtocols.Default
is actually SslProtocols.Ssl3 | SslProtocols.Tls
(checked for .Net Core 2.1 and .Net Framework 4.7.1).