如何使用JwtSecurityTokenHandler和JWKS端点验证JWT？

I am prototyping the use IdentityServer4 to secure several services, with the caveat that those services will likely not be migrated (in the forseeable future) to use the OWIN middleware idiom of ASP.NET Core. Consequently, I can not leverage the many middleware helpers that automate the validation of a JWT by simply providing the well-known JWKS endpoint of IdentityServer, among other things.I am prototyping the use IdentityServer4 to sec