VB加解密代码

 Function crypt(Action As String, Key As String, Src As String) As String
'Action
'  E encrypts, D decrypts,
'Key is a unique string needed to en/decrypt (either
'  hardcode or setup something for the user to enter.
'Src is the string to be en/decrypted.
On Error GoTo errHandler
    Dim count As Integer, KeyPos As Integer, KeyLen As Integer, SrcAsc As Integer
    Dim Dest As String, Offset As Integer, TmpSrcAsc, SrcPos As Integer
   
    KeyLen = Len(Key)
   
    If Action = "E" Then
        Randomize
        Offset = (Rnd * 10000 Mod 255) + 1
        Dest = Hex$(Offset)
   
        For SrcPos = 1 To Len(Src)
            SrcAsc = (Asc(Mid$(Src, SrcPos, 1)) + Offset) Mod 255
            If KeyPos < KeyLen Then KeyPos = KeyPos + 1 Else KeyPos = 1
            'Fill Dest$ with HEX representation of Encrypted field
            'Hex used to keep nasties such as eof or lf from mangling stream
            'Use format$ to make Hex$ return " 0" instead of "0" when the same
            'values are Xor'ed together (Null) - keeps placeholder for decrypt
            SrcAsc = SrcAsc Xor Asc(Mid$(Key, KeyPos, 1))
            Dest = Dest + Format$(Hex$(SrcAsc), "@@")
            Offset = SrcAsc
   
        Next
   
    ElseIf Action = "D" Then
        Offset = Val("&H" + Left$(Src, 2))
        For SrcPos = 3 To Len(Src) Step 2
            SrcAsc = Val("&H" + Trim(Mid$(Src, SrcPos, 2)))
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