private void initializeFromFile(File masterFile) throws Exception {
    try {
      List<String> lines = FileUtils.readLines(masterFile, "UTF8");
      String tag = lines.get(0);
      LOG.info("Loading from persistent master: " + tag);
      master = encryptionService.decrypt(lines.get(1), MASTER_PASSPHRASE).toCharArray();
    } catch (Exception e) {
      e.printStackTrace();
      throw e;
    }
  }
Ensures that the owner of this process is the only local user account able to read and write to
the specified file or read, write to, and execute the specified directory.

@param file the file or directory for which to modify access
ambari-server/src/main/java/org/apache/ambari/server/security/encryption/MasterKeyServiceImpl.java