Anti crawler mechanism solution: JS code generates random strings locally

This is an article in Python Notes in learning .
May we make progress together .

Problem description

Previous web Generally, there is no anti crawler mechanism on the end , But now we encounter this problem , It's about to cross this mountain , Conquer it .
In the process of learning reptiles , I climbed a dictionary , As a result, people crawled backwards ,error.

{
    “errorCode”:50}

Analyze and solve

Let's look at it first “ Review element ”, That is to choose “ Check ”, Shortcut key ：Ctrl + Shift + I
choice network, Find the network request for translation , Then check it out Headers

Results found , stay Request URL in , There is one more website “_o”, Generally, delete this item , To avoid anti crawler mechanism .

follow-up

This can indeed run successfully , however , It's not that simple .
In the view Form Data Find out ：

Unexpectedly, it has the same translation as before without anti crawler mechanism From Data The content is different , There are a few more , There are also a few items missing .

Two of them are the key signs of anti crawler ：
salt ： salt ？ Encryption function , It's about time , Is the timestamp of system time conversion .
sign： User's signature string , By constant 、 Time stamp 、 The character composition of user translation , There are specific ways to encrypt , Therefore, each translated character corresponds to sign Is not the same .

If you don't want to delete “_o” To solve , We need to understand their anti crawler mechanism , Find the encryption method , So as to deal with anti reptiles ——
Find all of them in the web page source code “JS file ”, Find related The suffix is “fanyi.js” Of （ It's easy to find , Blue link ）, After jumping, I got a full page of strange and disordered code .
Copy code to Code formatter In , You can format less strange code .
Search for “salt”, You can see that salt and sign How to define , Crack the encryption principle .