Store LDAP users and passwords in SQL

I'm researching a security model for our web portal, we have decided to use a partner that requires the users (and passwords) to be stored in some kind of LDAP.

Since we have a database with users (and current passwords hashed) already I would like to be able to use that database instead of the LDAP's m开发者_如何学Goethod of storing users and passwords.

We have no means of getting the passwords from the hash and we don't want to send new passwords to our customers.

What I would like is something that can "fake" the LDAP protocol and read the users from our MS SQL Database. The LDAP will only be used as authentication, the users permissions will be handled in another way.

Any suggestions?

You can use OpenLDAP with the SQL backend for exactly this.