javascript check mac address with key

 const os = require('os');

const crypto = require('crypto');

function getHashedMacAddress(secretKey) {
const networkInterfaces = os.networkInterfaces();
let macAddress = null;

// Iterate over network interfaces to find a valid MAC address
for (const interfaceName in networkInterfaces) {
for (const networkInterface of networkInterfaces[interfaceName]) {
// Exclude loopback interfaces and ensure it's not an internal address
if (!networkInterface.internal && networkInterface.mac !== '00:00:00:00:00:00') {
macAddress = networkInterface.mac;
break; // Found a MAC address, exit inner loop
}
}
if (macAddress) {
break; // Found a MAC address, exit outer loop
}
}

if (!macAddress) {
throw new Error('Could not find a valid MAC address on this machine.');
}

// Create an HMAC hash with the provided secret key
const hmac = crypto.createHmac('sha256', secretKey);
hmac.update(macAddress);
return hmac.digest('hex');
}

// Example usage:
const SECRET_KEY = 'your_super_secret_key'; // Replace with a strong, unique key
const EXPECTED_HASHED_MAC = 'your_precomputed_hashed_mac_constant'; // Replace with your constant

try {
const currentHashedMac = getHashedMacAddress(SECRET_KEY);

if (currentHashedMac === EXPECTED_HASHED_MAC) {
console.log('MAC address matches the expected constant.');
} else {
console.log('MAC address does NOT match the expected constant.');
console.log('Current Hashed MAC:', currentHashedMac);
}
} catch (error) {
console.error('Error:', error.message);
}