SiteMinder customers are entitled to use CA Directory to implement the policy store, key store and session store. However, you may find yourself having trouble to locate the CA Directory installation media from the support "My Downloads" page:
Release: 12.8
Component: SMPLC
This is because unless you license CA Directory separately, you really do not have the entitlement to use it for generic LDAP purposes, likes to use it as a User Directory.
However as a SIteMinder customer, you are entitled to use CA Directory for the three types of stores that you need for your SiteMinder implementation. As a result, the support CA Directory installation media is actually included within the area where you download your SiteMinder installation media:
How to download CA Directory 14 from the SiteMinder side: