本文是从ASP.NE T 1.1升级到ASP.NET 2.0需要考虑的Cookie问题的补充，通过示例代码说明如何通过反射在ASP.NET 1.1与ASP.NET 2.0中获取随机生成的cookie加密与验证密钥。
ASP.NET 1.1示例代码：
            object machineKeyConfig = HttpContext.Current.GetConfig("system.web/machineKey");
            //得到System.Web.Configuration.MachineKey+MachineKeyConfig的实例,MachineKeyConfig是MachineKey的嵌套类

            Type machineKeyType = machineKeyConfig.GetType().Assembly.GetType("System.Web.Configuration.MachineKey");
            //得到System.Web.Configuration.MachineKey类型

            BindingFlags bf = BindingFlags.NonPublic | BindingFlags.Static;
            //设置绑定标志

            MethodInfo byteArrayToHexString = machineKeyType.GetMethod("ByteArrayToHexString", bf);
            //通过反射获取MachineKey中的ByteArrayToHexString方法,该方法用于将字节数组转换为16进制表示的字符串

            Byte[] validationKey = (Byte[])machineKeyType.GetField("s_validationKey",bf).GetValue(machineKeyConfig);
            //获取验证密钥字节数组
            SymmetricAlgorithm algorithm = (SymmetricAlgorithm)machineKeyType.GetField("s_oDes",bf).GetValue(machineKeyConfig);
            Byte[] decryptionKey = algorithm.Key;
            //获取加密密钥字节数组
            string ValidationKey = (string)byteArrayToHexString.Invoke(null,new object[]{validationKey,validationKey.Length});
            //将验证密钥字节数组转换为16进制表示的字符串
            string DecryptionKey = (string)byteArrayToHexString.Invoke(null,new object[]{decryptionKey,decryptionKey.Length});
            //将加密密钥字节数组转换为16进制表示的字符串
ASP.NET 2.0示例代码：
         System.Web.Configuration.MachineKeySection machineKeySection = new System.Web.Configuration.MachineKeySection();
        //直接创建MachineKeySection的实例,ASP.NET 2.0中用machineKeySection取代ASP.NET 1.1中的MachineKey,并且可以直接访问,没有被internal保护。
        Type type = typeof(System.Web.Configuration.MachineKeySection);//或者machineKeySection.GetType();

        PropertyInfo propertyInfo = type.GetProperty("ValidationKeyInternal", BindingFlags.NonPublic | BindingFlags.Instance);
        Byte[] validationKeyArray = (Byte[])propertyInfo.GetValue(machineKeySection, null);
        //获取随机生成的验证密钥字节数组

        propertyInfo = type.GetProperty("DecryptionKeyInternal", BindingFlags.NonPublic | BindingFlags.Instance);
        Byte[] decryptionKeyArray = (Byte[])propertyInfo.GetValue(machineKeySection, null);
        //获取随机生成的加密密钥字节数组

        MethodInfo byteArrayToHexString = type.GetMethod("ByteArrayToHexString", BindingFlags.Static | BindingFlags.NonPublic);
        //通过反射获取MachineKeySection中的ByteArrayToHexString方法,该方法用于将字节数组转换为16进制表示的字符串
        string validationKey = (string)byteArrayToHexString.Invoke(null, new object[] { validationKeyArray, validationKeyArray.Length });
        //将验证密钥字节数组转换为16进制表示的字符串
        string DecryptionKey = (string)byteArrayToHexString.Invoke(null, new object[] { decryptionKeyArray, decryptionKeyArray.Length });
        //将加密密钥字节数组转换为16进制表示的字符串

        //作者Blog: http://dudu.cnblogs.com