Rhino HMAC (Pure JDK Standard Library)

rhino_hmac.js

function toHexString(byteArray) {
  return Array.from(byteArray, function(byte) {
    return ('0' + (byte & 0xFF).toString(16)).slice(-2);
  }).join('')
}

function hmac(algorithm, key, message) {
  var mac = javax.crypto.Mac.getInstance(algorithm);
  mac.init(new javax.crypto.spec.SecretKeySpec(key, algorithm));
  return mac.doFinal(message);
}

function generateHmac256(message, key) {
  var bytes = hmac("HmacSHA256", key, message.getBytes());
  return toHexString(bytes);
}

var valueToDigest = new java.lang.String("0123456789");
var key = (new java.lang.String("secret")).getBytes();
var messageDigest = generateHmac256(valueToDigest, key);
print(messageDigest);