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'EZ_Crypt.vb(字符串加密和解密类)

'参考Namespace
Imports System
Imports Microsoft.VisualBasic
Imports System.Collections
Imports System.Configuration

Namespace Security
Public Class Crypt
'加密字符串
Public Function Encrypt(ByVal PlainStr As String, ByVal key As String) As String
Dim strChar, KeyChar, NewStr As String
Dim Pos As Integer
Dim i, intLen As Integer
Dim Side1, Side2 As String
Pos = 1

For i = 1 To Len(PlainStr)
strChar = Mid(PlainStr, i, 1)
[color=#FFFFFF'][/color]

KeyChar = Mid(key, Pos, 1)
NewStr = NewStr &;amp; Chr(Asc(strChar) Xor Asc(KeyChar))
If Pos = Len(key) Then Pos = 0
Pos = Pos 1
Next

If Len(NewStr) Mod 2 = 0 Then
Side1 = StrReverse(Left(NewStr, (Len(NewStr) / 2)))
Side2 = StrReverse(Right(NewStr, (Len(NewStr) / 2)))
NewStr = Side1 &;amp; Side2
End If

Encrypt = NewStr
End Function

'解密字符串
Public Function Decrypt(ByVal PlainStr As String, ByVal key As String) As String
Dim strChar, KeyChar, NewStr As String
Dim Pos As Integer
Dim i As Integer
Dim Side1 As String
Dim Side2 As String
Pos = 1

If Len(PlainStr) Mod 2 = 0 Then
Side1 = StrReverse(Left(PlainStr, (Len(PlainStr) / 2)))
Side2 = StrReverse(Right(PlainStr, (Len(PlainStr) / 2)))
PlainStr = Side1 &;amp; Side2
End If

For i = 1 To Len(PlainStr)
strChar = Mid(PlainStr, i, 1)
KeyChar = Mid(key, Pos, 1)
NewStr = NewStr &;amp; Chr(Asc(strChar) Xor Asc(KeyChar))
If Pos = Len(key) Then Pos = 0
Pos = Pos 1
Next

Decrypt = NewStr
End Function
End Class
End