- 技术人生
- asp.net防盗链源码
/**/
/* * * 防盗链IHttpHandler * * * 增加了对文件关键字的选择(即仅对文件名存在某些关键字或不存在某些关键字进行过滤) * 设置web.config中<appSettings>节以下值 * string eWebapp_NoLink 如果文件名符合该正确表态式将进行过滤(不设置对所有进行过滤) * string eWebapp_AllowLink 如果文件名符合该正确表态式将不进行过滤(优先权高于AllowLink,不设置则服从AllowLink) * bool eWebapp_ AllowOnlyFile 如果为False,(默认true)则不允许用户直接对该文件进行访问建议为true * * * :)以下设置均可省略,设置只是为了增加灵活性与体验 * eWebapp_NoLink_Message 错误信息提示:默认为Link From:域名 * eWebapp_Error_Width 错误信息提示图片宽 * eWebapp_Error_Height 错误信息提示图片高 * * * * 垃圾猪 2005-9-11 创建 * http://ewebapp.net */
using
System;
using
System.Web;
using
System.Drawing;
using
System.Drawing.Imaging;
using
System.IO;
using
System.Configuration;
using
System.Text.RegularExpressions;
namespace
eWebapp
...
{ /**//// <summary> /// 防盗链IHttpHandler /// 参考http://www.softat.org/archiver/tid-52114.html /// 垃圾猪 2005-9-12 修正 /// </summary> public class NoLink : IHttpHandler ...{ private string eWebapp_NoLink = string.Empty; private string eWebapp_AllowLink = string.Empty; private bool eWebapp_AllowOnlyFile = true; private string eWebapp_NoLink_Message = string.Empty; private bool error = false; public NoLink() ...{ // // TODO: 在此处添加构造函数逻辑 // } public void ProcessRequest(HttpContext context) ...{ eWebapp_NoLink_Message = ConfigurationSettings.AppSettings["eWebapp_NoLink_Message"]; string myDomain = string.Empty; error = errorLink(context,out myDomain); if(Empty(eWebapp_NoLink_Message)) ...{ eWebapp_NoLink_Message = "Link from :" + myDomain; } if(error) ...{ //Jpg(context.Response,eWebapp_NoLink_Message); Jpg(context.Response,eWebapp_NoLink_Message); } else ...{ Real(context.Response,context.Request); } } public bool IsReusable ...{ get ...{ return true; } } /**//// <summary> /// 输出错误信息 /// </summary> /// <param name="Response"></param> /// <param name="_word"></param> private void Jpg(HttpResponse Response,string _word) ...{ int myErrorWidth = _word.Length*15; int myErrorHeight = 16; try ...{ int _myErrorWidth = Convert.ToInt32(ConfigurationSettings.AppSettings["eWebapp_Error_Width"]); if(_myErrorWidth > 0 ) ...{ myErrorWidth = _myErrorWidth; } } catch ...{ } try ...{ int _myErrorHeight = Convert.ToInt32(ConfigurationSettings.AppSettings["eWebapp_Error_Height"]); if(_myErrorHeight > 0 ) ...{ myErrorHeight = _myErrorHeight; } } catch ...{ } Bitmap Img=null; Graphics g=null; MemoryStream ms=null; Img=new Bitmap(myErrorWidth,myErrorHeight); g=Graphics.FromImage(Img); g.Clear(Color.White); Font f=new Font("Arial",9); SolidBrush s=new SolidBrush(Color.Red); g.DrawString(_word,f,s,3,3); ms=new MemoryStream(); Img.Save(ms,ImageFormat.Jpeg); Response.ClearContent(); Response.ContentType="image/Gif"; Response.BinaryWrite(ms.ToArray()); g.Dispose(); Img.Dispose(); Response.End(); } /**//// <summary> /// 输出真实文件 /// </summary> /// <param name="response"></param> /// <param name="context"></param> private void Real(HttpResponse response,HttpRequest request) ...{ FileInfo file = new System.IO.FileInfo(request.PhysicalPath); response.Clear(); response.AddHeader("Content-Disposition", "filename=" + file.Name); response.AddHeader("Content-Length", file.Length.ToString()); string fileExtension = file.Extension.ToLower(); //这里选择输出的文件格式 //可以参考http://ewebapp.cnblogs.com/articles/234756.html增加对更多文件格式的支持. switch (fileExtension) ...{ case "mp3": response.ContentType = "audio/mpeg3"; break; case "mpeg": response.ContentType = "video/mpeg"; break; case "jpg": response.ContentType = "image/jpeg"; break; case "bmp": response.ContentType = "image/bmp"; break; case "gif": response.ContentType = "image/gif"; break; case "doc": response.ContentType = "application/msword"; break; case "css": response.ContentType = "text/css"; break; default: response.ContentType = "application/octet-stream"; break; } response.WriteFile(file.FullName); response.End(); } /**//// <summary> /// 确认字符串是否为空 /// </summary> /// <param name="_value"></param> /// <returns></returns> private bool Empty(string _value) ...{ if(_value == null | _value == string.Empty | _value == "") ...{ return true; } else ...{ return false; } } /**//// <summary> /// 检查是否是非法链接 /// </summary> /// <param name="context"></param> /// <param name="_myDomain"></param> /// <returns></returns> private bool errorLink(HttpContext context,out string _myDomain) ...{ HttpResponse response = context.Response; string myDomain = context.Request.ServerVariables["SERVER_NAME"]; _myDomain = myDomain ; string myDomainIp = context.Request.UserHostAddress; eWebapp_NoLink = ConfigurationSettings.AppSettings["eWebapp_NoLink"]; eWebapp_AllowLink = ConfigurationSettings.AppSettings["eWebapp_AllowLink"]; try ...{ eWebapp_AllowOnlyFile = Convert.ToBoolean(ConfigurationSettings.AppSettings["eWebapp_AllowOnlyFile"]); } catch ...{ eWebapp_AllowOnlyFile = true; } if(context.Request.UrlReferrer != null) ...{ //判定referDomain是否存在网站的IP或域名 string referDomain = context.Request.UrlReferrer.AbsoluteUri.Replace(context.Request.UrlReferrer.AbsolutePath,""); string myPath = context.Request.RawUrl; if(referDomain.IndexOf(myDomainIp) >=0 | referDomain.IndexOf(myDomain)>=0) ...{ return false; } else ...{ //这里使用正则表达对规则进行匹配 try ...{ Regex myRegex ; //检查允许匹配 if(!Empty(eWebapp_AllowLink)) ...{ myRegex = new Regex(eWebapp_AllowLink); if(myRegex.IsMatch(myPath)) ...{ return false; } } //检查禁止匹配 if(!Empty(eWebapp_NoLink)) ...{ myRegex = new Regex(eWebapp_NoLink); if(myRegex.IsMatch(myPath)) ...{ return true; } else ...{ return false; } } return true; } catch ...{ //如果匹配出错，链接错误 return true; } } } else ...{ //是否允许直接访问文件 if(eWebapp_AllowOnlyFile) ...{ return false; } else ...{ return true; } } } } }
