I need to programmatically determine the TLS features of a client and underlying host based on Javascript.
What webserver instance (apache, IIS, etc), allows for different configurations of SSL ciphers to be loaded under different hostnames?
In this use-case, all clients support SNI. The only difference is that I want to make some pages read-only under old ciphers, and full access if using a modern browser.
My plan is to ask everyone to go to app.example.com, which will make a GET request to "legacy.example.com" and also "secure.example.com". If the secure connection succeeds, then we will proceed to that endpoint via a javascript induced redirect.
What webserver technology allows for this, and if I can do it under IIS, that is preferred.