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编程10000问
如何实现在下拉菜单里输入文字?
如何使用数组来显示下拉菜单?
如何用下拉列表显示数据库里的内容?
如何在读取Excel文件时创建列表的下拉菜单?
如何制作关联的下拉菜单?
如何测试字符串的长度?
如何验证字符串是否包含有效字符?
如何检测字符串出现的次数?
如何准确地获得一个整数?
如何编写一个小数转换分数的函数?
如何把一长串数字分位显示?
如何正确显示数据库里同时存在的GB码和BIG5码?
如何实现人民币的大写转换?
怎样给文件加密最安全?
如何用Access加密页面?
为什么用磁盘序列号加密过的代码不能被复制安装?
如何根据用户银行帐户余额的多少进行显式的提交或终止?
如何获知所有的Cookie?
如何提示用户打开Cookie?
如何刪除客户端的Cookies?

编程10000问 中的 怎样给文件加密最安全?


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2010-01-10   浏览: 23 ::
收藏到网摘: n/a

<%@ Language = VBScript%>
<%

Response.Expires = 0


p = "abcdefg"
Set TestPWD = New CPassWord
TestPWD.EnPWD p
TestPWD.UnPWD TestPWD.ShowPWD(True)
k = TestPWD.ShowPWD(True)
l = TestPWD.ShowPWD(False)
Set TestPWD = Nothing
With Response
.Write "
原文:" & p & "<br>"
.Write "
加密后:" & k & "<br>"
.Write "
解密后:" & L & "<br>"
End With

Class CPassWord
Private CEnPWD,CUnPWD
Private Function My_Hex(My_Hex_Source)
My_Hex = Hex(My_Hex_Source)
If Len(My_Hex) = 1 Then
My_Hex = "0" & My_Hex
End If
End Function
Private Function My_UnHex(My_UnHex_Source)
If Len(My_UnHex_Source) = 2 Then
Temp_Value = My_HexReplace(Left(My_UnHex_Source,1))
End If
My_UnHex = Temp_Value * 16 + My_HexReplace(Right(My_UnHex_Source,1))
End Function
Private Function My_HexReplace(My_HexReplace_Source)
If Asc(My_HexReplace_Source) > 64 Then
My_HexReplace = Asc(UCase(My_HexReplace_Source)) - 55
Else
My_HexReplace = Asc(My_HexReplace_Source) - 48
End If
End Function
Public Property Get ShowPWD(EnP)

' 输出.
If EnP Then
ShowPWD = CEnPWD
Else
ShowPWD = CUnPWD
End If
End Property
Sub EnPWD(EnPWD_Source)
if EnPWD_Source = "" then
CEnPWD = 0
Exit Sub
else
Randomize
Key = Rnd * 256
While Key = 0
Key = Rnd * 256
Wend
For i=1 To Len(EnPWD_Source)
Temp_String = Key Xor Asc(Mid(EnPWD_Source,i,1))
Crc = Crc + Temp_String
CEnPWD = CEnPWD + My_Hex(Temp_String)
Next
CEnPWD = My_Hex(Key) + StrReverse(CEnPWD) + My_Hex(Crc Mod 256)
End if
End Sub
Sub UnPWD(UnPWD_Source)
If Len(UnPWD_Source) < 6 Or Len(UnPWD_Source) Mod 2 = 1 then
CUnPWD = 0
Exit Sub
End If
Old_Key = My_UnHex(Left(UnPWD_Source,2))
Old_Crc = My_UnHex(Right(UnPWD_Source,2))
Old_String = StrReverse(Mid(UnPWD_Source,3,Len(UnPWD_Source)-4))
For i=1 To Len(Old_String) - 1 Step 2
Temp_Value = My_UnHex(Mid(Old_String,i,2))
Crc_Temp = Crc_Temp + Temp_Value
Temp_String = Temp_String + Chr(Temp_Value Xor Old_Key)
Next
If Old_Crc <> (Crc_Temp Mod 256) Then
CUnPWD = 403
Exit Sub
End If
CUnPWD = Temp_String
End Sub
End Class

%>