Manipulation binärer Daten durch TypedArrays in Next.js Edge-Middleware

export function verifyBinaryHeader(arrayBuffer, expectedMagicNumber) {
  if (!(arrayBuffer instanceof ArrayBuffer)) {
    throw new TypeError('Expected an ArrayBuffer instance');
  }
 
  const dataView = new DataView(arrayBuffer);
  if (dataView.byteLength < 4) {
    return false;
  }
 
  const magicHeader = dataView.getUint32(0, false);
  const payloadBytes = new Uint8Array(arrayBuffer, 4);
 
  return {
    isValid: magicHeader === expectedMagicNumber,
    checksum: payloadBytes.reduce((acc, byte) => (acc ^ byte) & 0xff, 0)
  };
}