OpenLDAP, PAM ...

Hi,
i want to change the authentication method of the users in the local
network . I want to use smartcards and centralized directory which
stores the information about them. I want to use smartcards with X.509
certificates and OpenLDAP server as Certification Authority .
I am not sure how should i configure the LDAP server to handle X.509
certificate. I saw also example pam configuration files of login with
ldap , but login expects password and not certificate. I really have
no idea how the infrastructre should look like :(((
Please give me more information .