I can connect with a user who has permissions to set passwords. I'm able to change attributes, but I can't set the password.
Found some instructions to set the attribute unicodePwd to \UNC:"password", but it says:
Error: Modify: Unwilling To Perform. <53>
Setting LDAP_OPT_ENCRYPT to 1 didn't work either. The port I'm using is 389.
Note: this is a repost of a question from stackoverflow, so please go and vote to close the original.