Get list of roles of the secure page

How I can get list of the access roles开发者_如何学C for the secure page on the login page?

        // Parse original url
        var originalUrl = FormsAuthentication.GetRedirectUrl(User.Identity.Name, false);
        var originalUrlArray = originalUrl.Split(new char[] { '/' }, StringSplitOptions.RemoveEmptyEntries);

        var pathToWebConfig = "~";
        for (int i = 0; i < originalUrlArray.Length - 1; i++) {
            pathToWebConfig += "/" + originalUrlArray[i];
        }

        var locationName = originalUrlArray[originalUrlArray.Length - 1];

        // Get web config
        var remoteWebConfig = (System.Configuration.Configuration)WebConfigurationManager.OpenWebConfiguration(pathToWebConfig);

        // Find authorization section
        AuthorizationSection authorizationSection = new AuthorizationSection();
        foreach (ConfigurationLocation location in remoteWebConfig.Locations) {
            if (location.Path.Equals(locationName)) {
                authorizationSection = (AuthorizationSection)location.OpenConfiguration().GetSection("system.web/authorization");
                break;
            }
        }

        // Get roles
        var listOfRoles = new List<string>();
        foreach (AuthorizationRule rule in authorizationSection.Rules) {
            if (rule.Action != AuthorizationRuleAction.Allow) {
                continue;
            }

            foreach (var role in rule.Roles) {
                listOfRoles.Add(role);
            }
        }