CampusFeed's device UDID generation. Use to take over a user's account.

GenerateCampusFeedUID.java

/**
 * getCampusFeedUid
 * Replicates the UID generation algorithm for CampusFeed
 * Run this function on the phone of a CampusFeed user to get the information needed to
 * take over their account.
 * Use the returned string in a Firebase Auth call as such:
 * createUserWithEmailAndPassword(getCampusFeedUid() + "@user.com", getCampusFeedUid());
 *
 * Requires:
 * android.provider.Settings.Secure
 * android.os.Build
 * android.telephony.TelephonyManager
 */
private String getCampusFeedUid() {
        if (VERSION.SDK_INT >= 23) {
            return Secure.getString(getApplicationContext().getContentResolver(), "android_id") + "#-#" + Build.SERIAL;
        }
        String str;
        TelephonyManager telephonyManager = (TelephonyManager) getSystemService(PlaceFields.PHONE);
        if (telephonyManager != null) {
            str = telephonyManager.getDeviceId() + "#-#" + Secure.getString(getContentResolver(), "android_id");
        } else {
            str = null;
        }
        if (str == null || str.length() == 0) {
            return Secure.getString(getContentResolver(), "android_id");
        }
        return str;
}