title: What's Client's Public Key of HTTPS two-way authentication?
body: <p>When HTTPS performs two-way authentication,
  The Server needs to obtain the Client's public key from the Client. </p>
  
  <p>I have question about the Public Key:</p>
  
  <p>The Client here is the browser, I want to know what's the Client's Public Key, does it refer to the Public Key of the Client's OS's? or is it mean a browser's ? if is browser's, how to check the Public Key of Chrome?</p>