privacy - How to get the missing Wifi MAC Address in Android Marshmallow and later?

Question

Android developers looking to get the Wifi MAC Address on Android M may have experienced an issue where the standard Android OS API to get the MAC Address returns a fake MAC Address (02:00:00:00:00:00) instead of the real value.

The normal way to get the Wifi MAC address is below:

final WifiManager wifiManager = (WifiManager) getApplication().getApplicationContext().getSystemService(Context.WIFI_SERVICE);

final String wifiMACaddress = wifiManager.getConnectionInfo().getMacAddress();

Answer 1

In Android M the MACAddress will be "unreadable" for WiFi and Bluetooth. You can get the WiFi MACAddress with (Android M Preview 2):

public static String getWifiMacAddress() {
    try {
        String interfaceName = "wlan0";
        List<NetworkInterface> interfaces = Collections.list(NetworkInterface.getNetworkInterfaces());
        for (NetworkInterface intf : interfaces) {
            if (!intf.getName().equalsIgnoreCase(interfaceName)){
                continue;
            }

            byte[] mac = intf.getHardwareAddress();
            if (mac==null){
                return "";
            }

            StringBuilder buf = new StringBuilder();
            for (byte aMac : mac) {
                buf.append(String.format("%02X:", aMac));
            }
            if (buf.length()>0) {
                buf.deleteCharAt(buf.length() - 1);
            }
            return buf.toString();
        }
    } catch (Exception ex) { } // for now eat exceptions
    return "";
}

(got this code from this Post)

Somehow I heared that reading the File from "/sys/class/net/" + networkInterfaceName + "/address"; will not work since Android N will be released and also there can be differences between the different manufacturers like Samsung etc.

Hopefully this code will still work in later Android versions.

EDIT: Also in Android 6 release this works