title: how does flask get the value back from session cookies?
body: <p>I was looking at a cookie set through the session object in flask and it was just a hash (or it looked like it was just a hash). The value I set for the cookie was nowhere to be found but flask could get the value back.</p>
  
  <p>I thought you had to store the value in the cookie alongside the hash (and then have a SECRET in your app to mix with the value for the hash), otherwise I don't know how you'd get your value back.</p>
  
  <p>I thought maybe they hash the secret and the value and then encode it for extra obfuscation or something along those lines.</p>