ReadHexStringToByte

    Public Function ReadHexStringToByte(ByVal Input As String) As Byte()
        Input = Input.ToUpper().Trim()
        If Input.Length = 0 Then GoTo fail

        Dim ValidChar As String = "0123456789ABCDEF"
        For Each character As Char In Input
            If Not ValidChar.Contains(character) Then GoTo fail
        Next

        If Input.Length Mod 2 = 1 Then Input = "0" & Input
        Dim ResultBytes As Byte() = New Byte(Input.Length / 2 - 1) {}
        Dim index As Integer = 0
        For i As Integer = 0 To Input.Length - 1 Step 2
            ResultBytes(index) = Convert.ToByte(Input.Substring(i, 2), 16)
            index += 1
        Next

        Return ResultBytes
fail:
        Throw New Exception("Invalid HexString")
    End Function