title: How to validate Json Web Token and extract details
body: <p>I have an ASP.Net WebAPI app that's working fine with basic userid/password authentication.</p>
  
  <p>However I also have to support authentication via Json Web Tokens.</p>
  
  <p>Apparently the JWT will contain an encrypted userid and a signature that I will need to verify, so I assume I will have keys for that.</p>
  
  <p>I don't need to create new tokens, I just need to validate them before I pass control to the usual webservice methods.
  It feels like it should be simple enough, but I haven't done this before and I'm having trouble finding examples online that (a) extract the contents and validate them, and (b) do not use out-of-date libraries.</p>
  
  <p>So, how do I do this, or do you know a good example online?
  Thanks</p>