大文件上传下载加密

<system.web>
   <httpModules>
            <add name="UploadModule" type="Bestcomy.Web.Controls.Upload.UploadModule,Bestcomy.Web.Controls.Upload" />
   </httpModules>
    <httpHandlers>
         <add verb="*" path="download.aspx" type="EPWeb.TrafficConfig.DownloadHandler,EPWeb"/>
    </httpHandlers>
   
  <httpRuntime maxRequestLength="40000" useFullyQualifiedRedirectUrl="true" executionTimeout="450"/>

调用代码：

 

using Bestcomy.Web.Controls.Upload; 

private void Page_Load(object sender, System.EventArgs e)
  ...{
   AspnetUpload upldr = new AspnetUpload();
   // upldr.RegisterProgressBar("ProgressBar.aspx",btn_upload);
   // upldr.RegisterProgressBar(btn_upload);
   // upldr.RegisterModelessProgressBar("ProgressBar.aspx",btn_upload);
   upldr.RegisterModelessProgressBar(btn_upload);
   string fpath = Path.Combine(Server.MapPath("."),"Upload");
   if(!Directory.Exists(fpath))
    Directory.CreateDirectory(fpath);
   upldr.set_UploadFolder(fpath); 
  }

    private void btn_upload_Click(object sender, System.EventArgs e)
  ...{   
   AspnetUpload upldr = new AspnetUpload();
   StringBuilder sb = new StringBuilder();
   foreach(UploadFile file in upldr.GetUploadFiles("file1"))
   ...{
    if(file != null)
    ...{
     string fpath = Path.Combine(Server.MapPath("."),"Upload");
     fpath = Path.Combine(fpath,Path.GetFileName(file.get_FileName()));     
     file.SaveAs(fpath);
        
     sb.Append("<strong>已录入文件:</strong>&nbsp;&nbsp;");
     string url = QueryFilename.EncryptFilename(Path.GetFileName(file.get_FileName()));
     sb.Append(""+Path.GetFileName(file.get_FileName())+"&nbsp;["+file.get_ContentLength().ToString("###,###")+"&nbsp;Bytes]"+"<br>");//<a href="download.aspx?filename="+url+"" target="_blank"></a>
    
     sb.Append("</div>");    
     Label1.Text=sb.ToString();
    
     


    } //if 
   }//foreach
  }

 

下面是一下下载类。

 

using System;
using System.Web;

namespace EPWeb.TrafficConfig
...{
 /**//// <summary>
 /// DownloadHandler class for large file download.
 /// </summary>
 public class DownloadHandler : IHttpHandler
 ...{
  public DownloadHandler()
  ...{
  }

  // Override the ProcessRequest method.
  public void ProcessRequest(HttpContext context)
  ...{
   HttpResponse Response = context.Response;
   HttpRequest Request = context.Request;

 

   System.IO.Stream iStream = null;

   // Buffer to read 10K bytes in chunk:
   byte[] buffer = new Byte[10240];

   // Length of the file:
   int length;

   // Total bytes to read:
   long dataToRead;

   try
   ...{
    // Identify the file name.
    string  filename  = QueryFilename.DecryptFilename(Request["filename"]);

    // Identify the file to download including its path.
    string filepath  = System.IO.Path.Combine(HttpContext.Current.Server.MapPath("."),"Upload\"+filename);

    // Open the file.
    iStream = new System.IO.FileStream(filepath, System.IO.FileMode.Open, 
     System.IO.FileAccess.Read,System.IO.FileShare.Read);
    Response.Clear();

    // Total bytes to read:
    dataToRead = iStream.Length;

    long p = 0;
    if(Request.Headers["Range"]!=null)
    ...{
     Response.StatusCode = 206;
     p = long.Parse( Request.Headers["Range"].Replace("bytes=","").Replace("-",""));
    }
    if(p != 0)
    ...{
     Response.AddHeader("Content-Range","bytes " + p.ToString() + "-" + ((long)(dataToRead - 1)).ToString() + "/" + dataToRead.ToString());                    
    }
    Response.AddHeader("Content-Length",((long)(dataToRead-p)).ToString());
    Response.ContentType = "application/octet-stream";
    Response.AddHeader("Content-Disposition", "attachment; filename=" + System.Web.HttpUtility.UrlEncode(System.Text.Encoding.GetEncoding(65001).GetBytes(filename)));
  //  Response.AddHeader("Content-Disposition", "attachment; filename=" + System.Web.HttpUtility.UrlEncode(Request.ContentEncoding.GetBytes(filename)));

    iStream.Position = p;
    dataToRead = dataToRead - p;
    // 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, 10240);

      // 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[10240];
      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();
   }
  }

  // Override the IsReusable property.
  public bool IsReusable
  ...{
   get ...{ return true; }
  }
 }
}

 

下面是一个加密文件名的类

 

using System;
using System.Web;

namespace EPWeb.TrafficConfig
...{
 /**//// <summary>
 /// QueryFilename class.
 /// </summary>
 public class QueryFilename
 ...{
  private QueryFilename()
  ...{
  }

  public static string EncryptFilename(string filename)
  ...{
   byte[] buffer = HttpContext.Current.Request.ContentEncoding.GetBytes(filename);
   return HttpUtility.UrlEncode(Convert.ToBase64String(buffer));
  }

  public static string DecryptFilename(string encryptfilename)
  ...{
   byte[] buffer = Convert.FromBase64String(encryptfilename);
   return HttpContext.Current.Request.ContentEncoding.GetString(buffer);
  }
 }
}