private byte[] getMessageBytes(HttpServletRequest req) throws IOException {
if (req.getMethod().equals(POST)) {
return IOUtils.toByteArray(req.getInputStream());
} else {
Operation op = getOperation(req);
if (op == Operation.PKI_OPERATION) {
String msg = req.getParameter(MSG_PARAM);
if (msg.length() == 0) {
return new byte[0];