LJ<OZ6IN?7N4<GTL?(M'4S8+3JMK5)HC%^1^+K;\$WBXPA?F&5^E\D$7%*O/U[1/?8(5:1OVWV*1Z-%`:K&V?X1,1KURD@3W0^D)<OG40?(VJ4EWL5A5M<$A);CQ36R9I]*U#Q%1<Y\&SA%#1<V
  
   下面再仔细分析一下上面的程序，我们发现其中的lowerbound和upperbound的数值
  其实就是你想使用来加密的ASCII字符范围。
  
  下面的代码将介绍如何使用这个密钥来加密和解密一个字符串
  
  Crypt.asp文件
  <%
  Dim g_Key
  
  Const g_CryptThis = "Now is the time for all good men to come to the aid of their country."
  Const g_KeyLocation = "c:\key.txt"
  
  g_Key = mid(ReadKeyFromFile(g_KeyLocation),1,Len(g_CryptThis))
  
  Response.Write "<p>ORIGINAL STRING: " & g_CryptThis & "<p>"
  Response.Write "<p>KEY VALUE: " & g_Key & "<p>"
  Response.Write "<p>ENCRYPTED CYPHERTEXT: " & EnCrypt(g_CryptThis) & "<p>"
  Response.Write "<p>DECRYPTED CYPHERTEXT: " & DeCrypt(EnCrypt(g_CryptThis)) & "<p>"
  
  Function EnCrypt(strCryptThis)
   Dim strChar, iKeyChar, iStringChar, i
   for i = 1 to Len(strCryptThis)
   iKeyChar = Asc(mid(g_Key,i,1))
   iStringChar = Asc(mid(strCryptThis,i,1))
   ' *** uncomment below to encrypt with addition,
   ' iCryptChar = iStringChar + iKeyChar
   iCryptChar = iKeyChar Xor iStringChar
   strEncrypted = strEncrypted & Chr(iCryptChar)
   next
   EnCrypt = strEncrypted
  End Function
  
  Function DeCrypt(strEncrypted)
  Dim strChar, iKeyChar, iStringChar, i
   for i = 1 to Len(strEncrypted)
   iKeyChar = (Asc(mid(g_Key,i,1)))
   iStringChar = Asc(mid(strEncrypted,i,1))
   ' *** uncomment below to decrypt with subtraction
   ' iDeCryptChar = iStringChar - iKeyChar
   iDeCryptChar = iKeyChar Xor iStringChar
   strDecrypted = strDecrypted & Chr(iDeCryptChar)
   next
   DeCrypt = strDecrypted
  End Function
  
  Function ReadKeyFromFile(strFileName)
   Dim keyFile, fso, f
   set fso = Server.CreateObject("scripting.FileSystemObject")
   set f = fso.GetFile(strFileName)
   set ts = f.OpenAsTextStream(1, -2)
  
   Do While not ts.AtEndOfStream
   keyFile = keyFile & ts.ReadLine
   Loop
&

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