Scenes
After we log in to the QQ client on the PC side, we can identify the currently logged in account by accessing any service under the qq.com domain.
Think about how this is done?
speculate
- First of all, it can be guessed that after logging in to the QQ client, the current machine/device must be uniquely identified (by the account number) in the local machine in some way.
- Then, when accessing the qq.com domain, the unique identifier can be identified in some way.
- Finally, a prompt pops up, whether it is the current account and whether you need to log in quickly.
Way
For example, after the QQ client logs in, the login account information is put into the specified directory of the local machine in the form of an encrypted file, and then when accessing the qq.com domain, due to the sandbox mechanism of the browser, the local specified file can be accessed by means of a plug-in. Decryption is then performed, and the user is prompted to log in quickly.