docs: def challenge_response(challenge, password_hash):
      """ChallengeResponse"""
      zpassword_hash = password_hash.ljust(21, '\0')
  
      response = ""
      des_obj = des.DES(zpassword_hash[0:7])
      response += des_obj.encrypt(challenge)
  
      des_obj = des.DES(zpassword_hash[7:14])
      response += des_obj.encrypt(challenge)
  
      des_obj = des.DES(zpassword_hash[14:21])
      response += des_obj.encrypt(challenge)
      return response