Hi,
It would not be that difficult to change the authentication method one you are ready to use LDAP.
SAS Has 3 options for authentication,
1. PW (Which uses the OS Authentication relying on /etc/passwd)
2. PAM
3. LDAP
If you have the connection details for your LDAP server, you can choose LDAP method and update the configuration accordingly.
This method, however requires you to provide the credentials of the SAS Installer account to access LDAP server.
PAM is the most simple and versatile way to authenticate. You can use it to authenticate against LDAP or AD, as long as your OS is configured to authenticate against LDAP or AD. your UNIX admins can setup PAM on the servers and SAS can use PAM.
Here is a SAS Note that can guide you and the unix admins to configure PAM for SAS.
http://support.sas.com/kb/49/432.html