krb5_keyblock_zero
krb5_keyblock_zero(&cache->key.keyblock);
krb5_keyblock_zero(&key);
krb5_keyblock_zero(&ccache->key.keyblock);
krb5_keyblock_zero (krb5_keyblock */*keyblock*/);
krb5_keyblock_zero(&ck);
krb5_keyblock_zero(&sk_verify);