Policy agents are an integral part of SSO and CDSSO sessions. They are programs that police the web container on which resources are hosted. All policy agents interact with the Authentication Service in two ways:
To authenticate itself in order to establish trust. This authentication happens using the Client SDK.
To authenticate users having no valid session for access to a protected resource. This authentication happens as a browser redirect from the Distributed Authentication User Interface.
When a user requests access to a protected resource such as a server or an application, the policy agent intercepts the request and redirects it to the OpenSSO Enterprise Authentication Service for authentication. Following this, the policy agent requests the authenticated user's assigned policy and evaluates it to allow or deny access. (A policy defines the rules that specify a user's access privileges to a protected resource.) OpenSSO Enterprise supports two types of policy agents:
The web agent enforces URL-based policy for C applications.
The Java EE agent enforces URL-based policy and Java-based policy for Java applications on Java EE containers.
Both types of agents are available for you to install as programs separate from OpenSSO Enterprise. Policy agents are basically clients written using the Client SDK and Identity Services.
All HTTP requests are implicitly denied unless explicitly allowed by the presence of a valid session and a policy allowing access. If the resource is defined in the Not Enforced list for the policy agent, access is allowed even if there is no valid session.
For more information, see J2EE Agent Architecture and Web Agent and C-API Architecture on the OpenSSO web site. For an overview of the available policy agents and links to specific information on installation, see the Sun OpenSSO Enterprise Policy Agent 3.0 User’s Guide for J2EE Agents.