IP block ASP.NET Module

IPBlockModule.cs

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net;
using System.Text.RegularExpressions;
using System.Web;
using System.Web.Caching;
using System.Web.Script.Serialization;

namespace Website.App_Code
{
    public class IPAddressLocation
    {
        public string ip { get; set; }
        public string country_code { get; set; }
        public string country_name { get; set; }
        public string region_code { get; set; }
        public string region_name { get; set; }
        public string city { get; set; }
        public string zip_code { get; set; }
        public string time_zone { get; set; }
        public float latitude { get; set; }
        public float longitude { get; set; }
        public int metro_code { get; set; }
    }

    public class IPBlockModule : IHttpModule
    {
        private EventHandler onBeginRequest;
        private static string _defaultCookieValue = "NCUTY";
        public IPBlockModule()
        {
            onBeginRequest = new EventHandler(this.HandleBeginRequest);
        }

        void IHttpModule.Dispose()
        {
        }

        public void Init(HttpApplication context)
        {
            context.BeginRequest += onBeginRequest;
        }

        void HandleBeginRequest(object sender, EventArgs e)
        {
            HttpApplication app = sender as HttpApplication;
            if (ModuleEnabled())
            {
                if (app != null)
                {
                    var countryCookie = app.Context.Request.Cookies["country"];
                    if (countryCookie == null || String.IsNullOrEmpty(countryCookie.Value))
                    {
                        var countryCode = GetCountryCode(app.Context);
                        countryCookie = new HttpCookie("country", countryCode);
                        if (countryCode == _defaultCookieValue) goto SecureLog;
                        countryCookie.Expires = DateTime.Now.AddMinutes(30);
                        app.Context.Response.Cookies.Add(countryCookie);
                    }

                    if (!string.IsNullOrEmpty(countryCookie.Value) && "ZA" == countryCookie.Value.ToUpper())
                    {

                        LogSecureAccessFile(app.Context.Request.UserHostAddress, countryCookie.Value, DateTime.Now, app.Context.Request.Path, "Deny");
                        app.Context.Response.Redirect("~/", true);
                    }
                    SecureLog:
                    LogSecureAccessFile(app.Context.Request.UserHostAddress, countryCookie.Value, DateTime.Now, app.Context.Request.Path, "Grant");
                }
            }
            
            
        }

        public static string GetCountryCode(HttpContext context)
        {
            return _GetCountryCodeFromIP(context.Request.UserHostAddress) ?? "_defaultCookieValue";
        }

        private static bool ModuleEnabled()
        {
            bool appSetting;
            if (!bool.TryParse(ConfigurationManager.AppSettings["UseIPBlockModule"],
                               out appSetting))
                appSetting = false;

            return appSetting;
        }

        private static string _GetCountryCodeFromIP(string ipaddress)
        {
            try
            {
                string url = "http://freegeoip.net/json/" + ipaddress;
                WebClient client = new WebClient();
                string jsonstring = client.DownloadString(url);
                var deserializer = new JavaScriptSerializer();
                var results = deserializer.Deserialize<IPAddressLocation>(jsonstring);
                return String.IsNullOrEmpty(results.country_code) ? _defaultCookieValue : results.country_code;
            }
            catch (Exception ex)
            {
                return _defaultCookieValue;
            }
        }

        private static void LogSecureAccessFile(string Ipaddress, string countryCode, DateTime date, string location, string authorize)
        {
            System.IO.StreamWriter sw = null;
            try
            {
                sw = new StreamWriter(System.AppDomain.CurrentDomain.BaseDirectory + "SecureAccess.txt", true);
                var str = String.Format("{0} : {1}, Country: {2}, Location {3}, Authorize {4}", date, Ipaddress, countryCode, location, authorize);
                sw.WriteLine(str);
                sw.WriteLine();
            }
            catch { }
            finally { sw.Close(); }
        }
    }
}