给config加密

Configuration config = WebConfigurationManager.OpenWebConfiguration("/");
            ConfigurationSection appSettings = config.GetSection("appSettings");
            if (appSettings.SectionInformation.IsProtected)
            {
                appSettings.SectionInformation.UnprotectSection();
            }
            else
            {
                appSettings.SectionInformation.ProtectSection(
                "DataProtectionConfigurationProvider");
            }
            config.Save();