Enterprise Library 4.1--加密应用程序块

学习这一块内容前，先得大概知道"哈希算法"和"对称加密算法"是咋回事儿.

不清楚的先去这里充电5分钟再回来

哈希算法------http://baike.baidu.com/view/273836.htm

对称加密算法--http://baike.baidu.com/view/7591.htm

使用步骤:

1.先添加Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.dll的引用

2.参照http://www.cnblogs.com/Terrylee/archive/2005/11/29/286688.html中所写，创建web.config中的相关节点

需要注意的是:
对称算法中的密钥文本文件，在asp.net环境中一定不要存放在网站目录下，否则谁都可以下载，形同虚设!

完成后，web.config内容大概如下:

<configuration>
    <configSections>
        
        <section name="securityCryptographyConfiguration" type="Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.Configuration.CryptographySettings, Microsoft.Practices.EnterpriseLibrary.Security.Cryptography, Version=4.1.0.0, Culture=neutral"/>
        
    </configSections>
    <securityCryptographyConfiguration>
        <hashProviders>
            <add algorithmType="System.Security.Cryptography.SHA256Managed, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" saltEnabled="true" type="Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.HashAlgorithmProvider, Microsoft.Practices.EnterpriseLibrary.Security.Cryptography, Version=4.1.0.0, Culture=neutral" name="SHA256Managed"/>
        </hashProviders>
        <symmetricCryptoProviders>
            <add algorithmType="System.Security.Cryptography.RC2CryptoServiceProvider, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" protectedKeyFilename="C:\key.txt" protectedKeyProtectionScope="LocalMachine" type="Microsoft.Practices.EnterpriseLibrary.Security.Cryptography.SymmetricAlgorithmProvider, Microsoft.Practices.EnterpriseLibrary.Security.Cryptography, Version=4.1.0.0, Culture=neutral" name="RC2CryptoServiceProvider"/>
        </symmetricCryptoProviders>
    </securityCryptographyConfiguration>
    
3.接下来就可以测试了，关键地方已经加了注释

using System;
using System.Text;
using Microsoft.Practices.EnterpriseLibrary.Security.Cryptography;

namespace EncryptTest
{
    public partial class _Default : System.Web.UI.Page
    {
        //这二个值必须与web.config相关Providers中的name一致
        private const string hashProvider = "SHA256Managed";
        private const string symmProvider = "RC2CryptoServiceProvider";
        

        protected void Page_Load(object sender, EventArgs e)
        {

        }

        /// <summary>
        /// 生成Hash散列值
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btnHash_Click(object sender, EventArgs e)
        {
            byte[] valueToHash = Encoding.Default.GetBytes(txtOriginal.Text);

            byte[] generatedHash = Cryptographer.CreateHash(hashProvider, valueToHash);

            // Clear the byte array memory
            Array.Clear(valueToHash, 0, valueToHash.Length);

            lHash.Text = Convert.ToBase64String(generatedHash);
        }

        /// <summary>
        /// 比较Hash散列值
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btnCompare_Click(object sender, EventArgs e)
        {
            byte[] valueToHash = System.Text.Encoding.UTF8.GetBytes(txtCompare.Text);

            if (lHash.Text != "")
            {
                bool matched = Cryptographer.CompareHash(hashProvider, valueToHash, Convert.FromBase64String(lHash.Text));

                // Clear the byte array memory
                Array.Clear(valueToHash, 0, valueToHash.Length);

                if (matched)
                {
                    lCompare.Text = "<span style='color:green'>该字符串未被篡改过!</span>";                    
                }
                else
                {
                    lCompare.Text = "<span style='color:red'>该字符串被修改过了!</span>";
                }
            }
        }

        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btnEncrypt_Click(object sender, EventArgs e)
        {
            lEncrypt.Text = Cryptographer.EncryptSymmetric(symmProvider, txtOriginal2.Text);
        }

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btnDecrypt_Click(object sender, EventArgs e)
        {
            lDecrypt.Text = Cryptographer.DecryptSymmetric(symmProvider, lEncrypt.Text);
        }
    }
}
 前端asp页
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="EncryptTest._Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <style type="text/css">
        *
        {
            font-size: 12px;
            line-height: 18px;
        }
        th
        {
            font-size: 14px;
            line-height: 20px;
        }
        .btn
        {
            height: 21px;
            width: 100px;
            line-height: 16px;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server">
    <table>
        <tr>
            <th colspan="3" align="center">
                Hash算法测试
            </th>
        </tr>
        <tr>
            <td align="right">
                输入要加密的文字：
            </td>
            <td>
                <asp:TextBox ID="txtOriginal" runat="server" Width="300px"></asp:TextBox>
            </td>
            <td align="left">
                <asp:Button ID="btnHash" runat="server" Text="生成Hash散列" OnClick="btnHash_Click" CssClass="btn" />
            </td>
        </tr>
        <tr>
            <td colspan="3" align="center">
                <asp:Literal ID="lHash" runat="server"></asp:Literal>
            </td>
        </tr>
        <tr>
            <td align="right">
                请输入要比较的文字：
            </td>
            <td>
                <asp:TextBox ID="txtCompare" runat="server" Width="300px"></asp:TextBox>
            </td>
            <td align="left">
                <asp:Button ID="btnCompare" runat="server" Text="比较Hash散列" OnClick="btnCompare_Click"
                    CssClass="btn" />
            </td>
        </tr>
        <tr>
            <td colspan="3" align="center">
                <asp:Literal ID="lCompare" runat="server"></asp:Literal>
            </td>
        </tr>
        <tr>
            <th colspan="3" align="center">
                对称加密算法测试
            </th>
        </tr>
        <tr>
            <td align="right">
                输入要加密的文字：
            </td>
            <td>
                <asp:TextBox ID="txtOriginal2" runat="server" Width="300px"></asp:TextBox>
            </td>
            <td align="left">
                <asp:Button ID="btnEncrypt" runat="server" Text=" 加 密 " CssClass="btn" OnClick="btnEncrypt_Click" />
            </td>
        </tr>
        <tr>
            <td colspan="3" align="center">
                <asp:Literal ID="lEncrypt" runat="server"></asp:Literal>
            </td>
        </tr>
        <tr>
            <td align="right">
                输入要解密的密码：
            </td>
            <td>
                <asp:TextBox ID="txtEncrypt" runat="server" Width="300px"></asp:TextBox>
            </td>
            <td align="left">
                <asp:Button ID="btnDecrypt" runat="server" Text=" 解 密 " CssClass="btn" 
                    onclick="btnDecrypt_Click"/>
            </td>
        </tr>
        <tr>
            <td colspan="3" align="center">
                <asp:Literal ID="lDecrypt" runat="server"></asp:Literal>
            </td>
        </tr>
    </table>
    </form>
</body>
</html>

运行界面图：