[Java] How to calculate and encode an element digest.

CalculateElementDigest.java

 /*
  * The following snippet calculates the SHA512 digest hash of the received element and return it as a BASE64
  * encode String. It is used to calculate the digest of the content of the request and it is an important
  * element of the signature. The expected parameter is the plain text representation of the request's body
  * being sent. For SOAP, it is the XML node being signed. For RESTful is the JSON document being sent.
  *
  * Gists provided for illustrative purposes only. Developers can use these as a support tool
  * but the Office of the Revenue Commissioners (Revenue) does not provide any warranty with 
  * these gists.
  */
public static String calculateAndEncodeElementDigest(InputStream element) throws IOException, NoSuchAlgorithmException {
    MessageDigest sha512Digest = MessageDigest.getInstance("SHA-512");
    ByteArrayOutputStream elementOutputStream = new ByteArrayOutputStream();
    byte[] elementData = new byte[1];

    while(element.read(elementData) != -1) {
        elementOutputStream.write(elementData);
    }

    elementOutputStream.flush();

    byte[] digest = sha512Digest.digest(elementOutputStream.toByteArray());

    return Base64.getEncoder().encodeToString(
            digest
    );
}

This does NOT use sha512 on the input value!!! it is just returning the base64 encode version of the input string!!!!

Hi neilm-fourjs, apologies for the delayed response. We have updated this gist.

Thanks for your input. Please don't hesitate to highlight other issues.