WooYun.org

else if (Request.QueryString["Type"] == "pdf")
            {
                if (!string.IsNullOrEmpty(Request.QueryString["FileName"]))
                {
                    string openulr = Server.MapPath(strPath + "/" + Request.QueryString["FileName"].ToString());
                    if (File.Exists(openulr))
                    {
                        System.IO.Stream iStream = null;
                        // Buffer to read 10K bytes in chunk:
                        byte[] buffer = new Byte[1000000];
                        // Length of the file:
                        int length;
                        // Total bytes to read:
                        long dataToRead;
                        string filepath = openulr;
                        // Identify the file name.
                        string filetype = System.IO.Path.GetFileName(filepath);
                        try
                        {
                            // Open the file.
                            iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open,
                                        System.IO.FileAccess.Read, System.IO.FileShare.Read);
                            // Total bytes to read:
                            dataToRead = iStream.Length;
                            Response.ContentType = "application/octet-stream";
                            Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(Request.QueryString["FileName"].ToString(), Encoding.UTF8).ToString().Trim());
                            // Read the bytes.
                            while (dataToRead > 0)
                            {
                                // Verify that the client is connected.
                                if (Response.IsClientConnected)
                                {
                                    // Read the data in buffer.
                                    length = iStream.Read(buffer, 0, 1000000);
                                    // Write the data to the current output stream.
                                    Response.OutputStream.Write(buffer, 0, length);
                                    // Flush the data to the HTML output.
                                    Response.Flush();
                                    buffer = new Byte[1000000];
                                    dataToRead = dataToRead - length;
                                }
                                else
                                {
                                    //prevent infinite loop if user disconnects
                                    dataToRead = -1;
                                }
                            }
                        }
                        catch (Exception ex)
                        {
                            // Trap the error, if any.
                            Response.Write("Error : " + ex.Message);
                        }
                        finally
                        {
                            if (iStream != null)
                            {
                                //Close the file.
                                iStream.Close();
                                Response.End();
                            }
                        }
                    }
                }
            }
            base.OnLoad(e);
        }
    }
}