url参数的编码解码Demo

为了保证在页面传递数据的安全性,我们通常会对Url传递的参数进行编码解码操作。我们写一个Demo剖析URL编码解码过程。

完整Demo下载地址

1. Url参数如何在服务端进行编码和解码。

1.1 Url参数编码

思路:

  1. 对Url的参数进行Base64编码
  2. 再进行Url编码。
  3. 将多个参数封装到键值对,调用工具类同一进行编码。
    代码:
             // 传递数据到详细页
            Product p = new Product() { Id = 1, Name = "泡椒凤爪", Price = 4.5m, Category = "零食" };
            // 封装到Dictionary中
            Dictionary dic = new Dictionary()
            {
                {"Id",p.Id.ToString()},
                {"Name",p.Name},
                {"Price",p.Price.ToString()},
                {"Category",p.Category}
            };
            // 进行Base64编码  返回数据 {"key":"value",...}
            string data = Helper.UrlCode.UrlEncode(dic);
            // 进行Url编码
            data = HttpUtility.UrlEncode(data, Encoding.UTF8);
            Response.Redirect("details.aspx?data=" + data);

工具类编码方法:

        public static string UrlEncode(Dictionary dic)
        {
            string res = "{";
            foreach (string key in dic.Keys)
            {
                byte[] buffer = Encoding.UTF8.GetBytes(dic[key]);
                string value = Convert.ToBase64String(buffer, 0, buffer.Length);
                res += key + ":" + value + ",";
            }
            res = res.Remove(res.Length - 1);
            res += "}";
            return res;
        }

编码后的地址:

http://localhost:50664/details.aspx?data={Id%3AMQ%3D%3D%2CName%3A5rOh5qSS5Yek54iq%2CPrice%3ANC41%2CCategory%3A6Zu26aOf}

1.2 Url参数解码

解码就更简单了,只需要取到Request中的数据,调用工具类解码。我们的数据就在返回的键值对中了。
代码:

                // 解码Url参数
                string data = Request["data"];
                Dictionary dicRes = Helper.UrlCode.UrlDecode(data);
                Pro = new Product();
                Pro.Id = int.Parse(dicRes["Id"]);
                Pro.Price = decimal.Parse(dicRes["Price"]);
                Pro.Name = dicRes["Name"];
                Pro.Category = dicRes["Category"];

工具类解码方法:

      public static Dictionary UrlDecode(string data)
        {
            Dictionary dic = new Dictionary();
            Dictionary dicRes = new Dictionary();
            data = data.Trim(new char[] { '{', '}' });
            string[] arrRes = data.Split(new char[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
            //"key":"value"
            for (int i = 0; i < arrRes.Length; i++)
            {
                string[] keyvalueArr = arrRes[i].Split(new char[] { ':' }, StringSplitOptions.RemoveEmptyEntries);
                dic[keyvalueArr[0]] = keyvalueArr[1];
            }
            foreach (var kvp in dic)
            {
                byte[] buffer = Convert.FromBase64String(kvp.Value);
                dicRes[kvp.Key] = Encoding.UTF8.GetString(buffer, 0, buffer.Length);
            }
            return dicRes;
        }

总结

我们依次对参数进行Base64编码和ulr编码。并且对多个参数进行统一的封装。而在解码时我们并没有调用Url解码是因为返回的数据已经进行了Url解码了。
可能有人会问进行Base64编码就可以满足需求了,为什么还要多此一举进行Url编码呢?
主要基于以下几个原因:

  1. url编码后,Base64编码中生成的’=‘ 等字符不容易引起混淆。
  2. Base64编码有可能产生'+' 这个字符,ASP.NET帮我们接受参数时会默认把'+' 替换为空格,所以此时数据就不对了。Url编码可以避免这种情况的发生。
  3. url编码后参数更加隐秘。

2.在客户端用js实现url参数编码。

js实现和服务端一样,只不过base64编码需要我们自己实现。

代码:

            // url参数编码
            var b = new Base64();
            // base64编码
            var data = "{Id:" + b.encode("1") + ",Name:" + b.encode('凤爪') +",Price:" + b.encode('4.5')+",Category:" + b.encode('零食')+ "}";
            data = encodeURIComponent(data); // URL编码
            location.href = '/details.aspx?data=' + data;

编码后的地址:

http://localhost:50664/details.aspx?data={Id%3AMQ%3D%3D%2CName%3A5rOh5qSS5Yek54iq%2CPrice%3ANC41%2CCategory%3A6Zu26aOf}


Base64对象:

       //  Base64 加密和解密
 
        function Base64() {
 
            // private property 
            _keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
 
            // public method for encoding 
            this.encode = function (input) {
                input += ''; // 转为string
                var output = "";
                var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
                var i = 0;
                input = _utf8_encode(input);
                while (i < input.length) {
                    chr1 = input.charCodeAt(i++);
                    chr2 = input.charCodeAt(i++);
                    chr3 = input.charCodeAt(i++);
                    enc1 = chr1 >> 2;
                    enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
                    enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
                    enc4 = chr3 & 63;
                    if (isNaN(chr2)) {
                        enc3 = enc4 = 64;
                    } else if (isNaN(chr3)) {
                        enc4 = 64;
                    }
                    output = output +
                    _keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
                    _keyStr.charAt(enc3) + _keyStr.charAt(enc4);
                }
                return output;
            }
 
            // public method for decoding 
            this.decode = function (input) {
                var output = "";
                var chr1, chr2, chr3;
                var enc1, enc2, enc3, enc4;
                var i = 0;
                input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
                while (i < input.length) {
                    enc1 = _keyStr.indexOf(input.charAt(i++));
                    enc2 = _keyStr.indexOf(input.charAt(i++));
                    enc3 = _keyStr.indexOf(input.charAt(i++));
                    enc4 = _keyStr.indexOf(input.charAt(i++));
                    chr1 = (enc1 << 2) | (enc2 >> 4);
                    chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
                    chr3 = ((enc3 & 3) << 6) | enc4;
                    output = output + String.fromCharCode(chr1);
                    if (enc3 != 64) {
                        output = output + String.fromCharCode(chr2);
                    }
                    if (enc4 != 64) {
                        output = output + String.fromCharCode(chr3);
                    }
                }
                output = _utf8_decode(output);
                return output;
            }
 
            // private method for UTF-8 encoding 
            _utf8_encode = function (string) {
                string = string.replace(/\r\n/g, "\n");
                var utftext = "";
                for (var n = 0; n < string.length; n++) {
                    var c = string.charCodeAt(n);
                    if (c < 128) {
                        utftext += String.fromCharCode(c);
                    } else if ((c > 127) && (c < 2048)) {
                        utftext += String.fromCharCode((c >> 6) | 192);
                        utftext += String.fromCharCode((c & 63) | 128);
                    } else {
                        utftext += String.fromCharCode((c >> 12) | 224);
                        utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                        utftext += String.fromCharCode((c & 63) | 128);
                    }
 
                }
                return utftext;
            }
 
            // private method for UTF-8 decoding 
            _utf8_decode = function (utftext) {
                var string = "";
                var i = 0;
                var c = c1 = c2 = 0;
                while (i < utftext.length) {
                    c = utftext.charCodeAt(i);
                    if (c < 128) {
                        string += String.fromCharCode(c);
                        i++;
                    } else if ((c > 191) && (c < 224)) {
                        c2 = utftext.charCodeAt(i + 1);
                        string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
                        i += 2;
                    } else {
                        c2 = utftext.charCodeAt(i + 1);
                        c3 = utftext.charCodeAt(i + 2);
                        string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
                        i += 3;
                    }
                }
                return string;
            }
        }

posted @ 2015-03-26 11:59  AfreadHuang  阅读(4826)  评论(4编辑  收藏  举报