一个可逆加密的例子

一个可逆加密的例子

下面的这个例子实现了一个可逆加密的例子功能。代码很简单，这里就不多解释了。代码如下：

EncString.aspx

<% @ Page Language = " vb "  AutoEventWireup = " false "  Codebehind = " EncString.aspx.vb "  Inherits = " aspxWeb.EncString " %>
<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
< HTML >
   < HEAD >
     < title > 一个可逆加密的例子 </ title >
     < meta  name ="GENERATOR"  content ="Microsoft Visual Studio.NET 7.0" >
     < meta  name ="CODE_LANGUAGE"  content ="Visual Basic 7.0" >
     < meta  name ="vs_defaultClientScript"  content ="JavaScript" >
     < meta  name ="vs_targetSchema"  content ="http://schemas.microsoft.com/intellisense/ie5" >
   </ HEAD >
   < body  MS_POSITIONING ="GridLayout" >
     < h3  align ="center" > 一个可逆加密的例子 </ h3 >
     < p  align ="center" >
       < form  id ="Form1"  method ="post"  runat ="server" >
         < FONT  face ="宋体" >
           < asp:TextBox  id ="TextBox1"  runat ="server"  Width ="96%" ></ asp:TextBox >
           < asp:RadioButtonList  id ="RadioButtonList1"  runat ="server"  Font-Bold ="True"
          RepeatDirection ="Horizontal"  AutoPostBack ="True"  OnSelectedIndexChanged ="ShowRes" >
           </ asp:RadioButtonList >
           < asp:TextBox  id ="TextBox2"  runat ="server"  Width ="96%" ></ asp:TextBox >
         </ FONT >
       </ form >
     </ p >
   </ body >
</ HTML >

 EncString.aspx.vb

Imports  System
Imports  System.IO
Imports  System.Xml
Imports  System.Text
Imports  System.Security.Cryptography
Public   Class  EncString
   Inherits  System.Web.UI.Page
   Protected   WithEvents  TextBox1  As  System.Web.UI.WebControls.TextBox
   Protected   WithEvents  TextBox2  As  System.Web.UI.WebControls.TextBox
   Protected   WithEvents  Form1  As  System.Web.UI.HtmlControls.HtmlForm
   Protected   WithEvents  RadioButtonList1  As  System.Web.UI.WebControls.RadioButtonList
#Region  " Web Form Designer Generated Code "
   ' This call is required by the Web Form Designer.
   < System.Diagnostics.DebuggerStepThrough() >   Private   Sub  InitializeComponent()
   End Sub
   Private   Sub  Page_Init( ByVal  sender  As  System.Object,_
    ByVal  e  As  System.EventArgs)  Handles   MyBase .Init
     ' CODEGEN: This method call is required by the Web Form Designer
     ' Do not modify it using the code editor.
    InitializeComponent()
   End Sub
#End Region
   Private   Sub  Page_Load( ByVal  sender  As  System.Object,_
    ByVal  e  As  System.EventArgs)  Handles   MyBase .Load
     ' Put user code to initialize the page here
     If   Not  IsPostBack  Then
       Dim  MyList  As   New  ArrayList()
      MyList.Add( " 加密 " )
      MyList.Add( " 解密 " )
      RadioButtonList1.DataSource  =  MyList
      RadioButtonList1.DataBind()
     End   If
   End Sub
   '  加密
   Public   Shared   Function  EncryptText( ByVal  strText  As   String )  As   String
     Return  Encrypt(strText,  " &%#@?,:* " )
   End Function
   ' 解密
   Public   Shared   Function  DecryptText( ByVal  strText  As   String )  As   String
     Return  Decrypt(strText,  " &%#@?,:* " )
   End Function
   ' 加密函数
   Private   Shared   Function  Encrypt( ByVal  strText  As   String ,_
    ByVal  strEncrKey  As   String )  As   String
     Dim  byKey()  As   Byte   =  {}
     Dim  IV()  As   Byte   =  { & H12,  & H34,  & H56,  & H78,  & H90,  & HAB,  & HCD,  & HEF}
     Try
      byKey  =  System.Text.Encoding.UTF8.GetBytes( Left (strEncrKey,  8 ))
       Dim  des  As   New  DESCryptoServiceProvider()
       Dim  inputByteArray()  As   Byte   =  Encoding.UTF8.GetBytes(strText)
       Dim  ms  As   New  MemoryStream()
       Dim  cs  As   New  CryptoStream(ms, des.CreateEncryptor(byKey, IV), CryptoStreamMode.Write)
      cs.Write(inputByteArray,  0 , inputByteArray.Length)
      cs.FlushFinalBlock()
       Return  Convert.ToBase64String(ms.ToArray())
     Catch  ex  As  Exception
       Return  ex.Message
     End   Try
   End Function
   ' 解密函数
   Private   Shared   Function  Decrypt( ByVal  strText  As   String ,_
    ByVal  sDecrKey  As   String )  As   String
     Dim  byKey()  As   Byte   =  {}
     Dim  IV()  As   Byte   =  { & H12,  & H34,  & H56,  & H78,  & H90,  & HAB,  & HCD,  & HEF}
     Dim  inputByteArray(strText.Length)  As   Byte
     Try
      byKey  =  System.Text.Encoding.UTF8.GetBytes( Left (sDecrKey,  8 ))
       Dim  des  As   New  DESCryptoServiceProvider()
      inputByteArray  =  Convert.FromBase64String(strText)
       Dim  ms  As   New  MemoryStream()
       Dim  cs  As   New  CryptoStream(ms, des.CreateDecryptor(byKey, IV), CryptoStreamMode.Write)
      cs.Write(inputByteArray,  0 , inputByteArray.Length)
      cs.FlushFinalBlock()
       Dim  encoding  As  System.Text.Encoding  =  System.Text.Encoding.UTF8
       Return  encoding.GetString(ms.ToArray())
     Catch  ex  As  Exception
       Return  ex.Message
     End   Try
   End Function
   Public   Sub  ShowRes( ByVal  sender  As   Object , _
   ByVal  e  As  System.EventArgs)  Handles  RadioButtonList1.SelectedIndexChanged
     If  RadioButtonList1.SelectedIndex  =   0   Then
      TextBox2.Text  =  EncryptText(TextBox1.Text)
     Else
      TextBox2.Text  =  DecryptText(TextBox1.Text)
     End   If
   End Sub
End Class