This is a migration scenario, I see at least 2 ways: a) some frontend (web?) app is built to proxy the user password to ldap by performing a bind.
This approach doe not really work in real deployments since it is not seamless for the end user.
b) we provide a pam module smart enough to check the user status against ldap if pam_kerb5 fails, and if it finds the user is in "upgrade" mode, perform an (SSL protected) simple bind against the ldap server. Simo.
This approach is better since user does not need to do anything. -- Dmitri Pal Engineering ManagerRed Hat Inc.