使用DESCryptoServiceProvider类对数据或者文件进行加密解密

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.Security.Cryptography;
using  System.IO;
using  System.Text;
namespace  CommonFunction
{
    /**//// <summary>
    /// secret 的摘要说明。
    /// </summary>
    public partial class secrettest : System.Web.UI.Page
    {
        protected string txtFilePath,fileExtName;

        Secret jiami = new Secret();

        protected void Page_Load(object sender, System.EventArgs e)
        {
            // 在此处放置用户代码以初始化页面
        }
        Web Form Designer generated code#region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN：该调用是 ASP.NET Web 窗体设计器所必需的。
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /**//// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {    

        }
        #endregion

        protected void btnJia_Click(object sender, System.EventArgs e)
        {
            txtNew.Text = jiami.DesEncrypt(txtValue.Text,"songxiud");
        }

        protected void btnJie_Click(object sender, System.EventArgs e)
        {
            txtValue.Text = jiami.DesDecrypt(txtNew.Text.Trim(),"songxiud");
        }

        protected void btnOpen_Click(object sender, System.EventArgs e)
        {
            if(filePath.PostedFile.FileName != "")
            {
                txtFilePath =filePath.PostedFile.FileName;
                fileExtName = txtFilePath.Substring(txtFilePath.LastIndexOf(".")+1,3);

                if(fileExtName !="txt" && fileExtName != "TXT")
                {
                    Response.Write("请选择文本文件");
                }
                else
                {
                    StreamReader fileStream = new StreamReader(txtFilePath,Encoding.Default);
                    txtContent.Text = fileStream.ReadToEnd();
                    fileStream.Close();
                }
            }
        }

        protected void btnFile_Click(object sender, System.EventArgs e)
        {
            jiami.DesEncrypt(Server.MapPath("txtFile")+"\\work.txt",Server.MapPath("txtFile")+"\\work1.txt","songxiud");
            StreamReader fileStream = new StreamReader(Server.MapPath("txtFile")+"\\work1.txt",Encoding.Default);
            txtContent.Text = fileStream.ReadToEnd();
            fileStream.Close();
        }

        protected void btnFileDes_Click(object sender, System.EventArgs e)
        {
            jiami.DesDecrypt(Server.MapPath("txtFile")+"\\work1.txt",Server.MapPath("txtFile")+"\\workjie.txt","songxiud");
            StreamReader fileStream = new StreamReader(Server.MapPath("txtFile")+"\\workjie.txt",Encoding.Default);
            txtContent.Text = fileStream.ReadToEnd();
            fileStream.Close();
        }

    
    }
}

<% @ Page language="c#" Inherits="CommonFunction.secrettest" CodeFile="secret.aspx.cs"  %>
<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"  >
< HTML >
     < HEAD >
         < title > secret </ title >
         < meta  content ="Microsoft Visual Studio 7.0"  name ="GENERATOR" >
         < meta  content ="C#"  name ="CODE_LANGUAGE" >
         < meta  content ="JavaScript"  name ="vs_defaultClientScript" >
         < meta  content ="http://schemas.microsoft.com/intellisense/ie5"  name ="vs_targetSchema" >
     </ HEAD >
     < body  bgColor ="#ccccff" >
         < form  id ="usersecret"  method ="post"  encType ="multipart/form-data"  runat ="server" >
             < FONT  face ="宋体" >
                 < asp:textbox  id ="txtValue"  style ="Z-INDEX: 101; LEFT: 168px; POSITION: absolute; TOP: 72px"  runat ="server" ></ asp:textbox >< asp:button  id ="btnJia"  style ="Z-INDEX: 102; LEFT: 344px; POSITION: absolute; TOP: 72px"  runat ="server"
                    Text ="数据加密"  onclick ="btnJia_Click" ></ asp:button >< asp:button  id ="btnJie"  style ="Z-INDEX: 103; LEFT: 344px; POSITION: absolute; TOP: 104px"  runat ="server"
                    Text ="数据解密"  onclick ="btnJie_Click" ></ asp:button >< asp:textbox  id ="txtNew"  style ="Z-INDEX: 104; LEFT: 168px; POSITION: absolute; TOP: 112px"  runat ="server" ></ asp:textbox >< asp:textbox  id ="txtContent"  style ="Z-INDEX: 105; LEFT: 168px; POSITION: absolute; TOP: 160px"
                    runat ="server"  Width ="200px"  Height ="296px"  TextMode ="MultiLine" ></ asp:textbox >< asp:button  id ="btnFile"  style ="Z-INDEX: 106; LEFT: 408px; POSITION: absolute; TOP: 312px"  runat ="server"
                    Text ="文件加密"  onclick ="btnFile_Click" ></ asp:button >< asp:button  id ="btnFileDes"  style ="Z-INDEX: 107; LEFT: 408px; POSITION: absolute; TOP: 384px"
                    runat ="server"  Text ="文件解密"  onclick ="btnFileDes_Click" ></ asp:button >< INPUT  id ="filePath"  style ="Z-INDEX: 108; LEFT: 408px; POSITION: absolute; TOP: 160px"
                    type ="file"  name ="File1"  runat ="server" >
                 < asp:button  id ="btnOpen"  style ="Z-INDEX: 109; LEFT: 408px; POSITION: absolute; TOP: 240px"  runat ="server"
                    Text ="打开文件"  onclick ="btnOpen_Click" ></ asp:button >
                 < asp:Label  id ="Label1"  style ="Z-INDEX: 110; LEFT: 168px; POSITION: absolute; TOP: 32px"  runat ="server" > 该示例以txtFile文件夹下的Work.txt文件为例 </ asp:Label ></ FONT ></ form >
     </ body >
</ HTML >

using  System;
using  System.Security.Cryptography;
using  System.IO;
using  System.Text;
namespace  CommonFunction
{
    /**//// <summary>
    ///数据加密、解密，文件的加密解密
    /// </summary>
    public class Secret
    {
        public Secret()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }

        public string DesEncrypt(string strText, string strEncrKey)
        {
            byte[] byKey=null;
            byte[] IV= {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
            try
            {
                byKey = System.Text.Encoding.UTF8.GetBytes(strEncrKey.Substring(0,strEncrKey.Length));
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                byte[] inputByteArray = Encoding.UTF8.GetBytes(strText);
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write) ;
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                return Convert.ToBase64String(ms.ToArray());


            }
            catch(System.Exception error)
            {
                return "error:" +error.Message+"\r";
            }
        }

        public string DesDecrypt(string strText,string sDecrKey)
        {
            byte[] byKey = null;
            byte[] IV= {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
            byte[] inputByteArray = new Byte[strText.Length];
            try
            {
                byKey = System.Text.Encoding.UTF8.GetBytes(sDecrKey.Substring(0,8));
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                inputByteArray = Convert.FromBase64String(strText);            
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write); 
                cs.Write(inputByteArray, 0, inputByteArray.Length); 
                cs.FlushFinalBlock();
                System.Text.Encoding encoding = new System.Text.UTF8Encoding();
                return encoding.GetString(ms.ToArray());
            }
            catch(System.Exception error)
            {
                return "error:"+error.Message+"\r";
            }

        }
        
        public void DesEncrypt(string m_InFilePath,string m_OutFilePath,string strEncrKey)
        {
            byte[] byKey=null;
            byte[] IV= {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
            try
            {
                byKey = System.Text.Encoding.UTF8.GetBytes(strEncrKey.Substring(0,8));
                FileStream fin = new FileStream(m_InFilePath, FileMode.Open, FileAccess.Read);
                FileStream fout = new FileStream(m_OutFilePath, FileMode.OpenOrCreate, FileAccess.Write);
                fout.SetLength(0);
                byte[] bin = new byte[100]; 
                long rdlen = 0;
                long totlen = fin.Length;
                int len; 
                DES des = new DESCryptoServiceProvider();
                CryptoStream encStream = new CryptoStream(fout, des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write);
                while(rdlen < totlen)
                {
                    len = fin.Read(bin, 0, 100);
                    encStream.Write(bin, 0, len);
                    rdlen = rdlen + len;
                }

                encStream.Close();
                fout.Close();
                fin.Close();
            }
            catch
            {
                
            }
        }

        public void DesDecrypt(string m_InFilePath,string m_OutFilePath,string sDecrKey)
        {
            byte[] byKey = null;
            byte[] IV= {0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF};
            try
            {
                byKey = System.Text.Encoding.UTF8.GetBytes(sDecrKey.Substring(0,8));
                FileStream fin = new FileStream(m_InFilePath, FileMode.Open, FileAccess.Read);
                FileStream fout = new FileStream(m_OutFilePath, FileMode.OpenOrCreate, FileAccess.Write);
                fout.SetLength(0);
                
                byte[] bin = new byte[100]; 
                long rdlen = 0; 
                long totlen = fin.Length; 
                int len; 

                DES des = new DESCryptoServiceProvider();
                CryptoStream encStream = new CryptoStream(fout, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write);

                while(rdlen < totlen)
                {
                    len = fin.Read(bin, 0, 100);
                    encStream.Write(bin, 0, len);
                    rdlen = rdlen + len;
                }

                encStream.Close();
                fout.Close();
                fin.Close();

            }
            catch
            {
                
            }


        }

        public string MD5Encrypt(string strText)
        {
            MD5 md5 = new MD5CryptoServiceProvider();
            byte[] result = md5.ComputeHash(System.Text.Encoding.Default.GetBytes(strText));
            return System.Text.Encoding.Default.GetString(result);
        }

        public string MD5Decrypt(string strText)
        {
            MD5 md5 = new MD5CryptoServiceProvider();
            byte[] result = md5.TransformFinalBlock(System.Text.Encoding.Default.GetBytes(strText),0,strText.Length);
            return System.Text.Encoding.Default.GetString(result);
        }
    }
}