public ServiceNowTicketValidatorService()
 {
     _safeguardAddress =
         ConfigUtils.ReadRequiredSettingFromAppConfig("SafeguardAddress", "Safeguard appliance network address");
     _safeguardClientCertificateThumbprint =
         ConfigUtils.ReadRequiredSettingFromAppConfig("SafeguardClientCertificateThumbprint",
                                                      "Safeguard client certificate thumbprint").ToUpper();
     _safeguardApiVersion =
         int.Parse(ConfigUtils.ReadRequiredSettingFromAppConfig("SafeguardApiVersion", "Safeguard API version"));
     _safeguardIgnoreSsl = bool.Parse(ConfigurationManager.AppSettings["SafeguardIgnoreSsl"]);
     _serviceNowDnsName  =
         ConfigUtils.ReadRequiredSettingFromAppConfig("ServiceNowDnsName", "ServiceNow server DNS name");
     _serviceNowClientSecret = ConfigUtils.ReadSettingFromAppConfigIfPresent("ServiceNowClientSecret")
                               ?.ToSecureString();
     _serviceNowUserName =
         ConfigUtils.ReadRequiredSettingFromAppConfig("ServiceNowUserName", "ServiceNow user name");
     _safeguardA2AApiKeyForServiceNowPassword = ConfigUtils
                                                .ReadRequiredSettingFromAppConfig("SafeguardA2AApiKeyForServiceNowPassword",
                                                                                  "Safeguard A2A API key for retrieving ServiceNow password").ToSecureString();
 }