来源:http://soft.yesky.com

　　你的主页或者你管理的网站有各种密码需要保护，把密码直接放在数据库或者文件中存在不少安全隐患，所以密码加密后存储是最常见的做法。在ASP.NET中实现加密非常容易。.NET SDK中提供了CookieAuthentication类，其中的HashPasswordForStoringInConfigFile方法可直接使用MD5和SHA1算法。例子如下：

　　file: encrypting.aspx

＜%@ Page language="c#" Codebehind="encrypting.cs" AutoEventWireup="false" Inherits="encrypting.encrypting" %＞
＜html＞＜head＞
＜meta name="GENERATOR" Content="Microsoft Visual Studio 7.0"＞
＜meta name="CODE_LANGUAGE" Content="C#"＞＜/head＞
＜body＞

＜form method="post" runat="server"＞

＜asp:TextBox id=TextBox1 runat="server"＞＜/asp:TextBox＞
＜asp:Button id=Button1 runat="server" Text="encrypting"＞＜/asp:Button＞
Encrypting Password(MD5):
＜asp:Label id=MD5 runat="server"＞＜/asp:Label＞
＜/form＞

＜/body＞＜/html＞

file:encrypting.cs

namespace encrypting
{
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Web.Security;
/// ＜summary＞
/// Summary description for encrypting.
/// ＜/summary＞
public class encrypting : System.Web.UI.Page
{
　protected System.Web.UI.WebControls.Label MD5;
　protected System.Web.UI.WebControls.Button Button1;
　protected System.Web.UI.WebControls.TextBox TextBox1;

　public encrypting()
　{
　　Page.Init += new System.EventHandler(Page_Init);
　}
　protected void Page_Load(object sender, EventArgs e)
　{
　　if (!IsPostBack)
　　{
　　　//
　　　// Evals true first time browser hits the page
　　　//
　　}
　}
　protected void Page_Init(object sender, EventArgs e)
　{
　　//
　　// CODEGEN: This call is required by the ASP+ Windows Form Designer.
　　//
　　InitializeComponent();
　}
　/// ＜summary＞
　/// Required method for Designer support - do not modify
　/// the contents of this method with the code editor.
　/// ＜/summary＞
　private void InitializeComponent()
　{
　　Button1.Click += new System.EventHandler (this.Button1_Click);
　　this.Load += new System.EventHandler (this.Page_Load);
　}
　public void Button1_Click (object sender, System.EventArgs e)
　{
　　MD5.Text = CookieAuthentication.HashPasswordForStoringInConfigFile(TextBox1.Text,"MD5");
　　//SHA1 use CookieAuthentication.HashPasswordForStoringInConfigFile(TextBox1.Text,"SHA1");
　}
}
}

　　注意：类CookieAuthentication的namespace是System.Web.Security。