title: Owin WS-Federation setting up token sliding expiration
body: <p>Can somebody explain how to implement sliding expiration using the new <strong>Owin WS-Federation</strong> plugin?</p>
  
  <p>On the client side, at WS-Fedeartion <strong>configuration</strong> I see that there are some <strong>events</strong> like :</p>
  
  <pre><code>  Notifications = new WsFederationAuthenticationNotifications
              {
                  SecurityTokenReceived = ...,
                  AuthenticationFailed = ...,
                  RedirectToIdentityProvider = ...,
                  MessageReceived = ...,
                  SecurityTokenValidated = ....
              },
  </code></pre>
  
  <p>But because the <strong>lack of documentation</strong> I can't really figure it out where an how?</p>
  
  <p>At the moment my <strong>STS is issuing tokens with absolute expiration</strong>:</p>
  
  <pre><code> protected override Lifetime GetTokenLifetime(Lifetime requestLifetime)
   {
          // 5 Minutes for token lifetime
          var lifetime = new Lifetime(DateTime.UtcNow, DateTime.UtcNow.AddMinutes(5));
          return lifetime;
   }
  </code></pre>
  
  <p>Any help is higly appreciated.</p>