There is an applicationthat obfuscates a serial number by padding each character. Here is a de-obfuscator I made.
First: define the array with all the characters the algorithm uses:
Public charArray() As Char = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9", _
"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", _
"K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", _
"V", "W", "X", "Y", "Z"}
Function that will deobfuscate it.
Private Function OffsetAChar(ByVal chartooffset As Char, ByVal offset As Integer)
Dim posInArray As Integer = Array.IndexOf(charArray, chartooffset)
Dim ArrayLength As Integer = charArray.Length
If posInArray + offset = ArrayLength Then
Return "0"
End If
If (posInArray + offset) <= ArrayLength And (posInArray + offset) > 0 Then
Return charArray(posInArray + offset)
End If
If posInArray + offset = 0 Then
Return 0
End If
If (posInArray + offset) < 0 Then
Return charArray(ArrayLength + posInArray + offset)
End If
If (posInArray + offset) > ArrayLength Then
Return charArray(Math.Abs(ArrayLength - (posInArray + offset)))
End If
End Function
Usage is simple:
Dim charArray2() As Char
Dim ArraySTring As String = txtDecode.Text
ArraySTring = ArraySTring.Replace("-", "")
charArray2 = ArraySTring
txtCodeDecoded.Text += OffsetAChar(charArray2(0), -19).ToString.ToUpper
Figuring out the offset of two letters
Public Function OffsetFinder(ByVal letter1 As Char, ByVal letter2 As Char)
Dim CharPos1 = Array.IndexOf(charArray, letter1)
Dim CharPos2 = Array.IndexOf(charArray, letter2)
Return CharPos2 - CharPos1
End Function
