CKA_SIGN
{ CKA_SIGN, &bool_true, sizeof(bool_true) }
add_object_attribute(o, 0, CKA_SIGN, &bool_true, sizeof(bool_true));
ret = pkinit_find_private_key(context, id_cryptoctx, CKA_SIGN, &obj);
FILL_ATTR(tpriv, npriv, CKA_SIGN, &true_val, sizeof(true_val));
FILL_ATTR(tpriv, npriv, CKA_SIGN, &true_val, sizeof(true_val));
key_filter[2].type = CKA_SIGN;