Attribute VB_Name = "modEncryption"
Option Explicit

Public Function Crypt(Action As String, Key As String, Src As String) As String
'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.

Dim count As Integer, KeyPos As Integer, KeyLen As Integer, SrcAsc As Integer
Dim Dest As String, Offset As Integer, TmpSrcAsc, SrcPos As Integer
Const KN_OFFSET = 91

KeyLen = Len(Key)

If Action = "E" Then
                    'Randomize
    'Offset = (Rnd * 10000 Mod 255) + 1     'Modified by randy gadingan
    Offset = KN_OFFSET
    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)))
        If KeyPos < KeyLen Then KeyPos = KeyPos + 1 Else KeyPos = 1
        TmpSrcAsc = SrcAsc Xor Asc(Mid$(Key, KeyPos, 1))
        If TmpSrcAsc <= Offset Then
            TmpSrcAsc = 255 + TmpSrcAsc - Offset
        Else
            TmpSrcAsc = TmpSrcAsc - Offset
        End If
        Dest = Dest + Chr(TmpSrcAsc)
        Offset = SrcAsc
    Next

End If
Crypt = Dest
End Function