Apologies, I have been working in ticket #570 and I send for your comments before the send
a patch final.
I was reviewing where else needs to change and I find this places
1 - krb5_auth.c ---> tevent_req *krb5_auth_send(
2 - krb5_utils.c ---> char *expand_ccname_template(
3 - ipa_dyndns.c ---> int create_nsupdate_message(