Imports System.IO
Imports System.Text
Imports System.Security.Cryptography

Public Class registerMe
    Private serial As String = "xxx"
    Private validserial As String = "QQHP7R-624F5T-7M39ZA-JWGETN-1QQ1BS-DD"
    Private Sub Registerbtn_Click(sender As Object, e As EventArgs) Handles Registerbtn.Click
        serial = Serialtxtbx.Text
        'validate serial
        If serial = validserial Then
            MessageBox.Show("Welcome! Serial accepted", "AccountEditor :: Licensing", MessageBoxButtons.OK, MessageBoxIcon.Information)
            IO.File.WriteAllText("license.pub", Encrypt(serial & vbTab & "04.10.2060" & vbTab & My.Computer.Name))
            LicenseCheck()
        Else
            MessageBox.Show("Serial is not valid", "AccountEditor :: Licensing", MessageBoxButtons.OK, MessageBoxIcon.Error)
        End If
    End Sub

    Private Function Encrypt(ByVal strText As String) As String
        Dim strEncrKey As String = "c8YXEft&+fMs@]ntv2!JyUuFs[#xgXek"
        Dim byKey() As Byte = {}
        Dim IV() As Byte = {&H33, &H62, &H57, &H33, &H23, &H40, &H6A, &H75, &H72, &H5B, &H5F, &H42, &H50, &H55, &H76, &H73}
        Try
            byKey = System.Text.Encoding.UTF8.GetBytes(strEncrKey.Substring(0, 16))

            Dim rijndael As New RijndaelManaged()
            Dim inputByteArray() As Byte = Encoding.UTF8.GetBytes(strText)
            Dim ms As New MemoryStream()
            Dim cs As New CryptoStream(ms, rijndael.CreateEncryptor(byKey, IV), CryptoStreamMode.Write)
            cs.Write(inputByteArray, 0, inputByteArray.Length)
            cs.FlushFinalBlock()
            Return Convert.ToBase64String(ms.ToArray())

        Catch ex As Exception
            Return ex.Message
        End Try

    End Function

    'The function used to decrypt the text
    Private Function Decrypt(ByVal strText As String) As String
        Dim sDecrKey As String = "c8YXEft&+fMs@]ntv2!JyUuFs[#xgXek"
        Dim byKey() As Byte = {}
        Dim IV() As Byte = {&H33, &H62, &H57, &H33, &H23, &H40, &H6A, &H75, &H72, &H5B, &H5F, &H42, &H50, &H55, &H76, &H73}
        Dim inputByteArray(strText.Length) As Byte

        Try
            byKey = System.Text.Encoding.UTF8.GetBytes(sDecrKey.Substring(0, 16))
            Dim rijn As New RijndaelManaged()
            inputByteArray = Convert.FromBase64String(strText)
            Dim ms As New MemoryStream()
            Dim cs As New CryptoStream(ms, rijn.CreateDecryptor(byKey, IV), CryptoStreamMode.Write)

            cs.Write(inputByteArray, 0, inputByteArray.Length)
            cs.FlushFinalBlock()
            Dim encoding As System.Text.Encoding = System.Text.Encoding.UTF8

            Return encoding.GetString(ms.ToArray())

        Catch ex As Exception
            Return ex.Message
        End Try
    End Function

    Private Sub registerMe_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        LicenseCheck()
    End Sub

    Private Sub LicenseCheck()
        If File.Exists("license.pub") Then
            Try
                serial = Decrypt(IO.File.ReadAllText("license.pub"))

                Dim SerialDate As DateTime = serial.Split(vbTab)(1)
                If serial.Split(vbTab)(0) = validserial Then
                    If DateTime.Compare(SerialDate.ToUniversalTime, DateTime.Now.Date.ToUniversalTime) = 1 Then
                        If My.Computer.Name = serial.Split(vbTab)(2) Then
                            Me.Hide()
                            selectAccount.ShowDialog()
                            Environment.Exit(0)
                        Else
                            Throw New Exception("Seems like your want to cheat the licensing system! Please delete license.pub and re-register this tool!")
                        End If
                    Else
                        Throw New Exception("Serial expired at " & serial.Split(vbTab)(1))
                    End If
                Else
                    Throw New Exception("Serial is not valid")
                End If
            Catch ex As Exception
                MessageBox.Show(ex.Message, "AccountEditor :: Licensing", MessageBoxButtons.OK, MessageBoxIcon.Error)
                Environment.Exit(0)
            End Try
        End If
    End Sub
End Class