krb5_decrypt_tkt_part
errcode = krb5_decrypt_tkt_part(kdc_context, st_sealing_key,
if ((retval = krb5_decrypt_tkt_part(context, (*auth_context)->keyblock,
retval = krb5_decrypt_tkt_part(context, &ktent.key, req->ticket);
krb5_error_code KRB5_CALLCONV krb5_decrypt_tkt_part