Can a application passing user id as a private key encrypted value access another application which uses CAS for SSO
<p>Lets say we have two applications</p>

<ol>
<li>App1 using CAS for authentication</li>
<li>External application App2 some custom authentication</li>
</ol>

<p>And a user with id 'user1'. This user once log in to App2 we want to display a link (link for App1) which allow the user to login to App1. User once clicks the link should be taken to App1.</p>

<p>App2 passes only the user id encrypted with a private key to App1. It will not pass password.</p>

<p>User ---------> External App2 -----Encrypted user id-----> CAS ===== App1</p>

<p>Is this possible to implement, as the request does not contain password?
Could you please guide me on the approach as this is first time I am working on CAS and SSO.</p>

<p>Your help is much appreciated.</p>

<p>We are using CAS 3.4 and Spring 3 integration.</p>