DES加密解密

Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Security.Cryptography;

using System.Text;



public class EncryptPassWord

{

    /// <summary>

    /// 获取密钥

    /// </summary>

    /// <returns></returns>

    public static string CreateSalt()

    {

        byte[] data = new byte[8];

        new RNGCryptoServiceProvider().GetBytes(data);

        return Convert.ToBase64String(data);

    }



    /// <summary>

    /// 加密密码

    /// </summary>

    /// <param name="pwdString"></param>

    /// <param name="salt"></param>

    /// <returns></returns>

    public static string EncryptPwd(string pwdString, string salt)

    {

        if (salt == null || salt == "")

        {

            return pwdString;

        }

        byte[] bytes = Encoding.Unicode.GetBytes(salt.ToLower().Trim() + pwdString.Trim());

        return BitConverter.ToString(((HashAlgorithm)CryptoConfig.CreateFromName("SHA1")).ComputeHash(bytes));

    }

}

Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->using System;

using System.Data;

using System.Configuration;

using System.Web;

using System.Web.Security;

using System.Security.Cryptography;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.IO;

using System.Text;

/// <summary>

/// Summary description for DESEncrypt

/// </summary>

public class DESEncrypt

{

    private string iv = "12345678";

    private string key = "12345678";

    private Encoding encoding = new UnicodeEncoding();

    private DES des;



    public DESEncrypt()

    {

        des = new DESCryptoServiceProvider();

    }



    /// <summary>

    /// 设置加密密钥

    /// </summary>

    public string EncryptKey

    {

        get { return this.key; }

        set

        {

            this.key = value;

        }        

    }



    /// <summary>

    /// 要加密字符的编码模式

    /// </summary>

    public Encoding EncodingMode

    {

        get { return this.encoding; }

        set { this.encoding = value; }

    }



    /// <summary>

    /// 加密字符串并返回加密后的结果

    /// </summary>

    /// <param name="str"></param>

    /// <returns></returns>

    public string EncryptString(string str)

    {

        byte[] ivb = Encoding.ASCII.GetBytes(this.iv);

        byte[] keyb = Encoding.ASCII.GetBytes(this.EncryptKey);//得到加密密钥

        byte[] toEncrypt = this.EncodingMode.GetBytes(str);//得到要加密的内容

        byte[] encrypted;

        ICryptoTransform encryptor = des.CreateEncryptor(keyb, ivb);

        MemoryStream msEncrypt = new MemoryStream();

        CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write);

        csEncrypt.Write(toEncrypt, 0, toEncrypt.Length);

        csEncrypt.FlushFinalBlock();

        encrypted = msEncrypt.ToArray();

        csEncrypt.Close();

        msEncrypt.Close();

        return this.EncodingMode.GetString(encrypted);

    }

}

1.原理:每次产生一个随机字符串作为密匙,用户输入一个密码,密码经过密匙加密得到一个字符串存放在数据库中...当需要验证密码时,要先得到密匙才能验证.

Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->//根据用户名得到用户信息       

 DataTable dt = WYTWeb.UserDAO.UserLogin(userName);

 if (dt.Rows.Count == 0)

 {

    return -2;//用户不存在

 }



 DataRow row = dt.Rows[0];

 //得到密匙

 string salt = row["salt"].ToString();

 //验证密码是否正确

 if (EncryptPassWord.EncryptPwd(password, salt) == row["password"].ToString())

 {

      //登录成功

 }

Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/--> //从基类获得登录id

 int userId = LoginUser_Id;

 //获得密匙

 string salt = EncryptPassWord.CreateSalt();

 //得到经过加密后的"密码"

 string password = EncryptPassWord.EncryptPwd(txtPassword.Text.Trim(), salt);

 //修改原数据

 int result = WYTWeb.UserDAO.EditPassword(userId, password, salt);

 if (result > 0)

 {

     WYTWeb.LogDAO.InsertLog("info","wytWeb","用户"+userId+"修改了密码", userId ,this.Request.UserHostAddress.ToString());

     ShowMessage("密码修改成功");

           //this.Response.Redirect("CompanyInfo.aspx"); 

 }

 else

 {

    WYTWeb.LogDAO.InsertLog("info", "wytWeb", "用户" + userId + "修改密码失败", userId, this.Request.UserHostAddress.ToString());

    ShowMessage("密码修改失败");

 }

 

 

转载地址：http://www.cnblogs.com/9421/archive/2010/02/21/1670682.html

 

http://www.cnblogs.com/yank/archive/2007/10/26/938180.html