sim123 wrote:
I am not sure what password modification extended operation is
It's a separate LDAP extended operation working on a already existing entry not a normal modify operation (see RFC 3062).
is it ldappasswd utility
Yes.
or does openLDAP offer some kind of API to do so?
See functions ldap_passwd/ldap_passwd_s in OpenLDAP's C API.
Also can how can I configure hashing in SLAPD?
You already posted the relevant FAQ entry.
Watch out for password-hash in man-page slapd.conf.
Ciao, Michael.