Kestrel Endpoints' "SslProtocols" settable via config (#22663)

[fstaffa]

Kestrel Endpoints' "SslProtocols" settable via config (#22663)

Priority of using SslProtocols is:

1. Code default
2. Configuration from EndpointDefaults section
3. Code configuration for named endpoint
4. Configuration from named endpoint section

[fstaffa]

I have tested the changes manually and they work ok. I have tried to write tests for the changes in KestrelConfigurationLoader but I didn't find a way to do so.
I can test the ConfigurationBackedListOptions (https://github.com/fstaffa/aspnetcore/blob/add-kestrel-ssl-protocols-in-config/src/Servers/Kestrel/Core/src/KestrelServerOptions.cs#L27 ) but that does not really test that the SslProtocols were correctly applied.
What I would like to test is results of
(https://github.com/fstaffa/aspnetcore/blob/add-kestrel-ssl-protocols-in-config/src/Servers/Kestrel/Core/src/KestrelConfigurationLoader.cs#L335 ) since this is the place which actually passes the SslProtocols configuration (as a part of httpsOptions) to the server. Do you knowhow to do that?

I also realized that changing EndpointDefaults in config does not cause configuration to reload. Is that expected or should I create an issue for that?

[halter73]

I'd like the nits addressed, but no big deal.

[halter73]

Looks great. Thanks @fstaffa!

[Tratcher]

Thanks