In order to prevent sharing links from being reported maliciously, some resource providers began to share them in the form of second transmission links. This paper explores the principle of second transmission link extraction, and introduces a simple usage.
be careful: This is an article published in 2021, and the relevant content is outdated.
With the update iteration of Baidu's online disk, from one key second to Access_Key semi-automatic second transmission, and then to all script writers who announced that they would stop maintenance, the era of big second transmission has gone forever.
Friends from search engines, if you are looking for a way to use SecondPass, please close this page~
How to use
Please skip to the next section about the principle.
Install extension and script (1 and 2 are required, not one of two options)
- Install extension components (required)
- For Chrome and shell browsers with the same core, please install
Tampermonkey Expansion.
- For FireFox browser, you can install
Tampermonkey Expand or Greasemonkey , recommend the former.
The Grease Monkey component allows you to insert additional js code into the browser to freely define the display and operation mode of the web page, and provides common interface encapsulation for development.
- Install oil monkey script (required)
>Note: This content is outdated
- Currently, the commonly used second transmission extraction script is Mengzonefire - link extraction per second 。 After clicking the link, click Install on the page.
- Note that after clicking Install, the oil monkey extension will pop up a prompt indicating whether to install it. Click Install.
Extract Link
Access under login status pan.baidu.com , there will be a Second transmission link Button:
Click this button, paste the second transmission link and click OK.
principle
I have a second transmission link starting with de0276e5f63e27f6604903727c299e7d. How is it used? First, take a look at the overview of the link:
de0276e5f63e27f6604903727c299e7d#1f5cfb6422675ae224739b496c3ea54c#202703879#/mirrornorabbit2.zip
In this link # The number separation is divided into four parts:
- File MD5
- First 256 KiB MD5
- File size (bytes, B)
- file name
We all know that Baidu online disk does not store a copy of the same file for each user, that is, only one copy of the file is kept on the server.
When a user deletes a file, the online disk only deletes the user's access to the file, and the physical file is not deleted. That is why we upload the file in seconds.
The principle of Baidu online disk second transmission is to verify the above two MD5 and file size. If they are consistent, the transfer operation is executed. Of course, this is not my nonsense, because there are the following descriptions in Baidu PCS API list:
Due to interface permissions and other problems, our commonly used transfer script does not use the rest api interface, but directly uses the Baidu online disk web end self use interface. The verification of this interface is very simple. Just find a shared file and upload it on the Baidu web disk and monitor the network:
To sum up, the second transmission link uses the second transmission interface of Baidu online disk to save the necessary parameters as strings in a specific format, so as to achieve the purpose of distribution and transfer.
At present, there are several common formats of second transmission link, but they are all the same. After decoding, they all have the same parameters.
key word
How to use Baidu Seconds Link
References
- [yeeach]【yeeach】 How to Create and Use Baidu Secondlink
