code: def validate_key(key_path):
      
  
      key_path = os.path.expanduser(key_path)
  
      if not os.path.isfile(key_path):
          return False
  
      return paramiko.RSAKey.from_private_key_file(key_path)
docs: Validate a key
  
          :param key_path: path to a key to use for authentication
          :type key_path: str
  
          :return: key object used for authentication
          :rtype: paramiko.RSAKey