I have a plugin that uses a WebInputStream (with https URL) to connect to my website. On most computers, it works fine. On an older iMac with OS X 10.10, it doesn’t connect. There is no response in the WebInputStream, so I assume there was an error connecting. There are messages in Console abouth SSLHandshake failed. So, I am guessing that the older mac is using an older TLS version (?). My website supports v1.2 and v1.3. I’m not sure how to determine what TLS version is being used. I don’t have a development environment on this older computer - just an installed binary plugin. Chrome has no problem accessing my website on the same computer and indicates that it is using TLS 1.3.
How do I control what version of TLS is used when I use WebInputStream? Or, as a start, how do I determine what version is being used on a given computer?