LINE Engineering

  • LINE x Amazon: Technical discussion
    Sho Tachibana 2018.03.16

    I am a technical evangelist for the LINE platform, including LINE Messaging API and LINE Login.

    We recently had a technical discussion with Amazon at their HQ, Seattle. Fifteen Liners from Planning, Sales, Development and Evangelism participated in the event, and I participated as a facilitator. My guess is that you'd want to find out what discussed, but unfortunately, all I can share with you for now is the non-technical aspects of the trip. So, I'll briefly share some of the pictures.

    Tech Discussion @ Amazon

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  • Bot Designer for previewing conversation with chatbots
    Kazuki Nakajima 2018.03.15

    Bot Designer is an application which allows you to simulate and preview a conversation with a chatbot.


    With the LINE Messaging API, you can make a bot send various types of messages such as texts, images, stickers, locations to a LINE user. To check how these messages are actually displayed on the LINE app, what you had to was to create a JSON object representing the message, call the Messaging API, and then check the sent message on the LINE app. Now, with Bot Designer, you can do it by simply entering information in the input fields of Bot Designer which automatically converts the information into JSON objects and renders message previews. You will get the idea right away when you watch the following video clip.

    LINE BOT BOT Designer

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  • LINE opens community site for third party developers
    Kazuki Nakajima 2018.03.13

    We are very pleased to announce that we have opened a new site, the LINE Developers community site, which you can easily access from the existing LINE developers site. Note the links are added on the top navigation bar and the left-hand side menu of the developer site.


    LINE Developers LINE API

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  • The structure of the LINE LIVE's encoder layer
    Suhyuk Kim 2018.03.06

    On December 10th of 2017, we celebrated our second anniversary for LINE LIVE, our live streaming service. The service has been up and running ever since the launch with no trouble, thanks to the efforts put in by countless engineers at LINE. On this blog post, as a member of ITSC, a team at LINE running a global infrastructure system, I'd like to share with you some of decisions we had to make in the initial phase of designing and implementing the system. Back then, I had absolutely no experience in building or running a live media service.

    AdventCalendar LINE LIVE Live Broadcasting PC Broadcasting Live Video

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  • Buffer overflow in PJSIP, a VoIP open source library
    Kim Youngsung 2018.02.27

    He's a security engineer at LINE. He enjoys looking for bugs and is highly interested in secure coding.

    Hi all, I am Youngsung Kim (Facebook, Twitter) of the Application Security team at LINE and am in charge of evaluating security of LINE services. On this post, I'd like to share a vulnerability (CVE-2017-16872, AST-2017-009) of PJSIP, a VoIP open source library. PJSIP is a multimedia communication library based on the following standard protocols; SIP, SDP, RTP, STUN, TURN, and ICE. The Asterisk framework, widely used on IP-PBX and VoPI gateway has an SIP stack implemented based on PJSIP.

    The cause of the vulnerability was due to incautiousness about sign extension for Integers in the process of converting signed int to unsigned long when handling client's SIP requests on 64-bit environment. There was no window to report the security issue to the PJSIP development teams, so I made my report to the Asterisk's security page. Afterwards, I've consulted with George Joseph, an engineer at Asterisk, and the patch (PJSIP patch, Asterisk patch) has been applied on the pjproject v2.7.1. I'd like to express my gratitude to George for processing the patch.

    VoIP Security Vulnerability OpenSource CVE PJSIP PJPROJECT ASTERISK AdventCalendar

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