Dart HMAC SHA 256 Example code

example.dart

import 'dart:html';
import 'dart:convert';
import 'package:crypto/crypto.dart';

void main() {

  String secret = 'secret';
  String message = 'Message';

  List<int> secretBytes = UTF8.encode('secret');
  List<int> messageBytes = UTF8.encode('Message');
  
  var hmac = new HMAC(new SHA256(), secretBytes);
  hmac.add(messageBytes);
  var digest = hmac.close();
  
  var hash = CryptoUtils.bytesToBase64(digest);
  
  // output to html page
  querySelector('#hash').text = hash;
  // hash => qnR8UCqJggD55PohusaBNviGoOJ67HC6Btry4qXLVZc=
}

Thanks for the heads up