Before implement Linkedin login authentication first we need create Linkedin application and need to get api key from Linkedin for that open this link https://www.linkedin.com/secure/developer once you open that link we have option like “Add New Application” click on it that will display window like this
Once you enter all the details click ok now api key will generate for your application. Now open your application and write the following code in your aspx page
<title>Linkedin Authentication Login in Asp.net Website</title>
<form id="form1" runat="server">
Hello, <?js= firstName ?> <?js= lastName ?>.
In header section replace Your_API_KEY with your api key. Once we run above code we will get output of Sign in Button like as shown below
Once we click on that button another window will open and it will ask access permission for that application for your details like as shown below
Once you click the Allow access button you will get output like as show below
In this way we can implement Linkedin authentication for your web application.
Here you need to remember one point that is once you get the output please try to refresh your page for few times you will notice that login button reappears every time, even though you have already logged into the app and granted permission. By default, Linkedin framework will only fetch an OAuth token if the user explicitly clicks a Sign In button. You can override this to auto-login signed in users for that set the option authorize: true, and the framework will automatically fetch an OAuth token if one is available (i.e. if the user has previously authorized your application). For that you need to change header script code like as shown below
In this way we can implement linkedin authentication mechanism for website.