title: Sharing ADFS authentication across multiple domains
body: <p>I have a set of applications that could possibly be hosted under different domains or as sub-domains of a common domain.</p>
  
  <p>All of these applications will authenticate against the same ADFS service.</p>
  
  <p><strong>I want my application to automatically login, if another application has authenticated with the same ADFS service.</strong></p>
  
  <p>For example, you only need to login into google once, and then if you visit any of their application sites ( Gmail / Google Drive / Google+ ), you are automatically logged into the application.</p>
  
  <p>Hence, let's say we have an ADFS service <strong>ADFS_AUTH_SERVICE</strong>.</p>
  
  <p>Application <strong>Website1</strong> authenticates with <strong>ADFS_AUTH_SERVICE</strong>.</p>
  
  <p>User visits <strong>Website2</strong> which is also configured to authenticate with <strong>ADFS_AUTH_SERVICE</strong> .</p>
  
  <p>Hence, <strong>when user visits Website2 he should be automatically logged in</strong>.</p>
  
  <p><strong>UPDATE:</strong> For more clarity, following is the sequence that is currently occuring:</p>
  
  <p><strong>1.</strong>  User enters <code>http://site1/Home</code></p>
  
  <p><strong>2.</strong>  User is redirected to the online Microsoft ADFS authentication page.</p>
  
  <p><strong>3.</strong>  User enters his details and successfully authenticates with ADFS service and is redirected to <code>http://site1/Home</code></p>
  
  <p><strong>4.</strong>  User's name is visible on <code>http://site1/Home</code>.</p>
  
  <p><strong>5.</strong>  User clicks on a link in site1 that takes him to <code>http://site2/Home</code></p>
  
  <p><strong><em>Expected Result:</em></strong> User's name should be visible on site2/Home</p>
  
  <p><strong><em>Actual Result:</em></strong> User is redirected to the ADFS login page.</p>