Introduction : clearly quoted a correct image address, but the show is a red fork or write "This image is limited to the user communication and communication use of" the "fake pictures" (that is, NetEase blog anti-theft chain effect). Using sniffer software to find the real address of the multimedia resources with the download software still cannot download. There is always an error when downloading some resources, and if you confirm the correct address, most of the cases are caught in the anti-theft chain system. Common anti-theft chain system, generally used in pictures, audio and video, software and other related resources.
first, what is the anti-theft chain system:
In the case of ensuring the correct address, can not download the corresponding resources are affected by the anti-theft chain system, then what is the anti-theft chain system? Anti-theft chain nature is to prevent hotlinking, so here first say what is hotlinking.
hotlinkingis to show something on your page that is not on your own server. It is common practice to obtain the address of a resource on its human server by technical means, bypassing other people's resource presentation pages and providing this content directly to the end user on its own page. More common is some small station misappropriation of the resources (Pictures, music, video, software, etc.), for these stations, through the Hotlinking method can alleviate their own server burden, because the real space and traffic are from other people's servers. Anti-theft chain system is to guard against hotlinking system, to prevent others through a number of technical means to bypass the site's resources display page, misappropriation of the resources of the site, so that the resource link around the Folio station resource links failed. After the implementation of the anti-theft chain system, because the shielding of those hotlinking indirect resource requests, which can greatly reduce the pressure on the server and bandwidth, is also the case, more and more sites are beginning to implement anti-theft chain technology.
second, peep Anti-theft chain:now everyone should know why the real address is still unable to download, this is the role of anti-theft chain. Everything must have cause and effect, why can anti-theft chain, and its implementation of the principle is what? How is the anti-theft chain implemented? Referring to the implementation of the anti-theft chain principle has to start from the HTTP protocol, in the HTTP protocol, there is a header field called Referer, in the format of the URL to indicate from where to link to the current page or file. In other words, through Referer, the Web site can detect the source page of the target page access, and if it is a resource file, it can be traced to the page address where it is displayed. With the Referer tracking source is good to do, at this time can be handled by technical means, once detected source is not the site to block or return to the specified page. If you want to protect your site against theft, you need to treat different situations differently. If the site server is using Apache, then using the Apache URL rewrite feature can easily prevent various hotlinking, the principle is to check the refer, if the refer information from other sites are redirected to the specified image or Web page. If the server is using IIS, you need to use a third-party plug-in to implement the anti-theft chain function, now more commonly used a product called isapi_rewrite, can achieve similar to the Apache anti-theft chain function. In addition, for the Forum can also use "Login verification" method for anti-theft chain.
third, to the son of the systemizing, anti-theft chain crack:
Although the anti-theft chain technology more and more mature, crack relatively difficult, but after understanding the principle, most of them can be based on the principle of prevention to crack. For the picture anti-theft chain, has been given a detailed code, the corresponding code page the author has uploaded to the author's previous personal blog space, in the forwarding of pictures, in front of the picture address with "http://www.z7z8.com.cn/old/pic.asp?url=" Address can solve the picture anti-theft chain problem. If you have their own website space can be downloaded directly from Http://www.z7z8.com.cn/old/pic.zip, unzip and upload to their own space, paste the picture address before adding "Domain/path/pic.asp?url=" can be. For the file resources of the anti-theft chain, you can use the method of human-referenced pages to solve the problem cannot be downloaded, such as to obtain the address of the http://www.z7z8.com.cn/old/pic.zip, the download found the use of anti-theft chain technology, when the new download task can be artificially added " Reference page: ". Because the vast majority of anti-theft chain is only to determine the reference page is not the site, so this method can break through the chain to download, but not all the circumstances are valid. By default, Thunder's New Task dialog box is not "reference page" item, you need to execute "tool → configuration" in the Thunderbolt, in the Open Configuration Panel dialog box, in the "Task Default Properties" tab, tick the "New Panel display reference page" check box.
Tips:The above discussion is only the primary anti-theft chain also cracked, with the rapid development of technology, anti-theft chain technology also developed rapidly, so now the anti-theft chain technology to be advanced, more complex. So the above mentioned cracking method does not necessarily apply to all anti-theft chain conditions. This article is from the "Off-road Wolf blog" 51 blog
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