Sun Java System Access Manager Policy Agent 2.2 Guide for BEA WebLogic Server 9.0/9.1

Web-Tier Security Details

When the deployment container gets a request for a resource that is protected by the web-tier declarative security-constraint, it must evaluate the credentials of the user against the agent realm to ensure that only authorized requests go through. In order to process such a request, the deployment container requires the user to sign on using the specified form login page as mentioned in the form-login-config element of the web.xml descriptor. Based on the specification of the FORM authentication mechanism, it is required that the user submits a valid user name as j_username and a valid password as j_password to the special URI j_security_check using the HTTP POST method of form submission.

The agent, once configured to support web-tier declarative security for the given application can isolate the request for accessing form-login-page and instead can stream out some data to the client browser. This data contains the user’s login name and temporary encrypted password, which in turn uses Javascript to do automatic form submission as required. This gives the user a seamless single sign-on experience since the user does not have to re-login in order to access the protected resources for a deployed application that uses web-tier declarative security.

By default, the content that the agent sends to the client browser on intercepting a request for the form login page is read from the file called FormLoginContent.txt located in the locale directory of the agent installation. This file contains the following HTML code:

      <title>Security Check</title>
   <body onLoad="document.security_check_form.submit()">
      <form name="security_check_form" action="j_security_check" method="POST">
         <input type="hidden" value="am.filter.j_username" name="j_username">
         <input type="hidden" value="am.filter.j_password" name="j_password">


Before the agent streams out the contents of this file, it replaces all occurrences of the string am.filter.j_username by the appropriate user name. Similarly, all occurrences of the string am.filter.j_password are replaced by a temporary encrypted string that acts as a one-time password for the user.