X-LS.md

LINE SESSION (LINE 會話週期)

What is X-LS

It is LINE SESSION, It is used to omit user authentication

How to get the X-LS?

When you are in a connection, after using X-LINE-ACCESS to request, server will provide X-LS in the header

LINE Request Example

->  POST ga2.line.naver.jp/P5
    Headers:
        X-Line-Application: ANDROID	11.2.1	Android OS	9.0.0
        X-Line-Access: mid:xxxxxxxxx..xxxxxxxxxx=

<-  OK ga2.line.naver.jp/P5
    Headers:
        x-lc: 200
        x-ls: xxxxxxxxxxxxxxx

<-  POST ga2.line.naver.jp/P5
    Headers:
        x-ls: xxxxxxxxxxxxxxx

<-  POST ga2.line.naver.jp/S4
    Headers:
        x-ls: xxxxxxxxxxxxxxx

<-  POST ga2.line.naver.jp/CH4
    Headers:
        x-ls: xxxxxxxxxxxxxxx
......

But what are the benefits?

Since user checks are omitted, it maybe processed by server faster
MAYBE...

The disadvantages outweigh the benefits?

X-LS must be the same connection, uhh... http/1.1 or... Keep-Alive yea
So when you create a new connection, X-LS will fail
You have to schedule all requests, and it is almost impossible to process them at the same time, otherwise you need multiple x-ls for multiple connections

Others

另外在回應中也有出現x-lc, 它是status code, 當你的x-lpv為1時, server將始終回應OK(200), 取而代之的是將實際的status code塞進x-lc給你
Example:

->  POST gd2.line.naver.jp/xx/api/xx/xxx
    Headers:
        x-lpv: 1

<-  OK gd2.line.naver.jp/xx/api/xx/xxx
    Headers:
        x-lc: 404