Question

One of the client requirements is that the server generate files and store them on a special folder. This files created can not be modified by users or deleted.
So the only way I thought is to generate this files with elevated privileges so a normal user can’t delete or modify them.
But the question is how can I generate a file with this privileges that normal users can interact with this files… only download from server.

I use this code to generate the file… But I don’t know how to configure it for elevated privileges.

This is the button which generate the file and allow to download it:

Protected Sub ibtGenerar_OnClick(ByVal sender As Object, ByVal e As ImageClickEventArgs)
    oArchivoTelecredito.NombreArchivo = txtNombreArchivo.Text
    oArchivoTelecredito.SesionDetalleArchivosTelecredito = New List(Of DetalleArchivoTelecreditoBE)
    Dim oArchivoTelecreditoSL As New ArchivoTelecreditoSL
    Response.AddHeader("Content-disposition", "attachment;filename=" & oArchivoTelecredito.NombreArchivo & ".txt")
    Response.ContentType = "application/octet-stream"
    Response.BinaryWrite(oArchivoTelecreditoSL.GeneraArchivoTelecredito(oArchivoTelecredito, Server.MapPath(oArchivoTelecredito.NombreArchivo)))
    Response.End()
End Sub

This is the function which create the file on server:

Public Function GeneraArchivoTelecredito(ByVal telecredito As ArchivoTelecreditoBE, ByVal ruta As String) As Byte()
            Dim lineas As Integer = telecredito.SesionDetalleArchivosTelecredito.Count + 1
            Dim registro(0 To lineas) As String
            registro(0) = Me.ObtenerCabeceraArchivoTelecredito(telecredito)
            Dim archivo = ruta & ".txt"
            Using escritor As New StreamWriter(archivo)
                For index = 0 To lineas
                    escritor.WriteLine(registro(index))
                Next
                escritor.Close()
            End Using
            Dim lector As FileStream
            lector = File.Open(archivo, FileMode.Open)
            Dim bytes(lector.Length) As Byte
            lector.Read(bytes, 0, lector.Length)
            lector.Close()
            Return bytes
        End Function

Answer 1

If you want to set the file to be read-only then you can use

File.SetAttributes("PathToFile", FileAttributes.ReadOnly).

You could also set the permissions on the directory itself instead of the individual files – see this post: https://serverfault.com/questions/3878/is-there-a-way-to-prevent-a-file-from-being-deleted