ldap_add read binary from file

["W.Schefe" <w.schefe@bauwi.de>]

Hallo, group,
my question:
I want to insert a userCertificate from a file into the tree with

ldap_add ... -f ldif.ldif ... and the ldif- construct

userCertificate;binary:< file:///usr/local/certificat.asc

(the certificat.asc is a normal utf8 pgp text file)
The result is, that the file was been red, it starts add and breaks with
ldap_add: Invalid syntax
        additional info: userCertificate;binary: value #0 invalid per syntax

Where I can find out more about this problem or, what is a solution, so that I get back
while searching the inserted userCertificate as file ?

Thanks, Wolfgang