Imports System.Text
Public Class PXOR
    Private regKey As String = ""
    Public Property Key() As String
        Get
            Return regKey
        End Get
        Set(ByVal value As String)
            regKey = value
        End Set
    End Property
    Public Sub New(ByVal Key As String)
        Me.Key = Key
    End Sub
    Public Sub New()
        Me.Key = ""
    End Sub



    Public Function PolyCrypt(ByVal Data As String) As String
        Return Encoding.Default.GetString(PolyCrypt(Encoding.Default.GetBytes(Data)))
    End Function
    Public Function PolyDeCrypt(ByVal Data As String) As String
        Return Encoding.Default.GetString(PolyDeCrypt(Encoding.Default.GetBytes(Data)))
    End Function
    Public Function PolyCrypt(ByVal Data() As Byte) As Byte()
        Dim ReturnBuffer(Data.Length) As Byte
        ReturnBuffer(0) = Convert.ToByte(New Random().Next(1, 255))
        For i = 0 To Data.Length - 1
            ReturnBuffer(i + 1) = ModuloByte(ReturnBuffer(i), Data(i))
        Next
        Return XorCrypt(ReturnBuffer, Encoding.Default.GetBytes(Key))
    End Function
    Public Function PolyDeCrypt(ByVal Data() As Byte) As Byte()
        Data = XorCrypt(Data, Encoding.Default.GetBytes(Key))
        Dim ReturnBuffer(Data.Length - 2) As Byte
        For i = Data.Length - 1 To 1 Step -1
            ReturnBuffer(i - 1) = ModuloByte(Data(i), -Data(i - 1))
        Next
        Return ReturnBuffer
    End Function
    Private Function ModuloByte(ByVal MyByte As Byte, ByVal Addition As Int16) As Byte
        While Addition < 0
            Addition += 256
        End While
        Return Convert.ToByte((MyByte + Addition) Mod 256)
    End Function
    Private Function XorCrypt(ByVal Data() As Byte, ByVal Key() As Byte) As Byte()
        If Key.Length <> 0 Then
            For i = 0 To Data.Length - 1
                Data(i) = Data(i) Xor ModuloByte(Key(i Mod Key.Length), [Key](Key(i Mod Key.Length) Mod Key.Length)) Xor [Key](((i + (i Mod 7)) Mod Key.Length) Mod Key.Length)
            Next
        End If
        Return Data
    End Function
    Public Function XorCrypt(ByVal Data As String, ByVal Key As String) As String
        Return Encoding.Default.GetString(XorCrypt(Encoding.Default.GetBytes(Data), Encoding.Default.GetBytes(Key)))
    End Function
End Class