Safari ​

const serverCertificatePath =
  'https://cert.sigmadrm.com/app/fairplay/{MECHANT_ID}/{APP_ID}';
function loadCertificate() {
  var request = new XMLHttpRequest();
  request.responseType = 'arraybuffer';
  request.addEventListener('load', onCertificateLoaded, false);
  request.addEventListener('error', onCertificateError, false);
  request.open('GET', serverCertificatePath, true);
  request.send();
}
function onCertificateLoaded(event) {
  var request = event.target;
  certificate = new Uint8Array(request.response);
  console.log('Certificate: ', certificate);
  /*
    Start video at here. Here, we call function startVideo()
    */
  startVideo();
}
function onCertificateError(event) {
  window.console.error('Failed to retrieve the server certificate.');
  /*
    Retry get certificate here
    */
}

function startVideo() {
  var video = document.getElementsByTagName('video')[0];
  video.addEventListener('webkitneedkey', onneedkey, false);
  video.addEventListener('error', onerror, false);
  // ADAPT: there must be logic here to fetch/build the appropriate m3u8 URL
  video.src = '{M3U8_URL}';
}
function onerror(event) {
  window.console.error('A video playback error occurred', event);
}
function onneedkey(event) {
  console.log('onneedkey: ', event);
  var video = event.target;
  var initData = event.initData;
  var contentId = extractContentId(initData);
  initData = concatInitDataIdAndCertificate(initData, contentId, certificate);

  if (!video.webkitKeys) {
    selectKeySystem();
    video.webkitSetMediaKeys(new WebKitMediaKeys(keySystem));
  }

  if (!video.webkitKeys) throw 'Could not create MediaKeys';
  console.log('Init Data: ', btoa(initData));
  var keySession = video.webkitKeys.createSession('video/mp4', initData);
  if (!keySession) throw 'Could not create key session';

  keySession.contentId = contentId;
  waitForEvent('webkitkeymessage', licenseRequestReady, keySession);
  waitForEvent('webkitkeyadded', onkeyadded, keySession);
  waitForEvent('webkitkeyerror', onkeyerror, keySession);
}
function extractContentId(initData) {
  parserInitData(initData);
  var contentId = licenseUrl.searchParams.get('assetId');
  return contentId;
}
function parserInitData(initData) {
  var url = arrayToString(initData).substring(1);
  licenseUrl = new URL(url);
  licenseUrl.protocol = 'https';
}
function concatInitDataIdAndCertificate(initData, id, cert) {
  if (typeof id == 'string') id = stringToArray(id);
  var offset = 0;
  var buffer = new ArrayBuffer(
    initData.byteLength + 4 + id.byteLength + 4 + cert.byteLength,
  );
  var dataView = new DataView(buffer);

  var initDataArray = new Uint8Array(buffer, offset, initData.byteLength);
  initDataArray.set(initData);
  offset += initData.byteLength;

  dataView.setUint32(offset, id.byteLength, true);
  offset += 4;

  var idArray = new Uint16Array(buffer, offset, id.length);
  idArray.set(id);
  offset += idArray.byteLength;

  dataView.setUint32(offset, cert.byteLength, true);
  offset += 4;

  var certArray = new Uint8Array(buffer, offset, cert.byteLength);
  certArray.set(cert);

  return new Uint8Array(buffer, 0, buffer.byteLength);
}
function selectKeySystem() {
  if (WebKitMediaKeys.isTypeSupported('com.apple.fps.1_0', 'video/mp4')) {
    keySystem = 'com.apple.fps.1_0';
  } else {
    throw 'Key System not supported';
  }
}
function waitForEvent(name, action, target) {
  target.addEventListener(
    name,
    function () {
      console.log('Wait For Event: ', name, arguments);
      action(arguments[0]);
    },
    false,
  );
}

function licenseRequestFailed(event) {
  window.console.error('The license request failed.');
}

function onkeyerror(event) {
  window.console.error('A decryption key error was encountered', event);
}

function onkeyadded(event) {
  window.console.log('Decryption key was added to session.');
}

function licenseRequestReady(event) {
  var session = event.target;
  var message = event.message;
  var request = new XMLHttpRequest();
  var sessionId = event.sessionId;
  request.responseType = 'text';
  request.session = session;
  request.addEventListener('load', licenseRequestLoaded, false);
  request.addEventListener('error', licenseRequestFailed, false);
  // var params = 'spc=' + base64EncodeUint8Array(message) + '&assetId=' + encodeURIComponent(session.contentId);
  var params = JSON.stringify({
    spc: base64EncodeUint8Array(message),
    assetId: encodeURIComponent(session.contentId),
  });
  console.log(message);
  request.open('POST', licenseUrl.toString(), true);
  request.setRequestHeader('Content-type', 'application/json');
  request.setRequestHeader(
    'custom-data',
    btoa(
      JSON.stringify({
        userId: 'USER_ID',
        sessionId: 'SESSION_ID',
        merchantId: 'MERCHANT_ID',
        appId: 'APP_ID',
      }),
    ),
  );
  request.send(params);
}

function licenseRequestLoaded(event) {
  var request = event.target;
  var session = request.session;
  // response can be of the form: '\n<ckc>base64encoded</ckc>\n'
  // so trim the excess:
  var wrappedString = request.responseText.trim();
  var wrapped = JSON.parse(wrappedString);
  var keyText = wrapped.license;
  console.log('request license: ', request);
  if (keyText.substr(0, 5) === '<ckc>' && keyText.substr(-6) === '</ckc>')
    keyText = keyText.slice(5, -6);
  key = base64DecodeUint8Array(keyText);
  session.update(key);
}