Google+ Authentication in ASP.Net

In this article you will learn how to use Google Plus authentication in ASP.NET.

How to get Google API access:

Google-Plus-Authentication-in-ASPNet-1.jpg
  • Click the "Create new client ID" button.
Google-Plus-Authentication-in-ASPNet-1.jpg
  • It will open a dialog box to create a new Client ID.
Google-Plus-Authentication-in-ASPNet-2.jpg
  • Select Web Application and Set the Authorized JavaScript origins (example: http://localhost), Authorized redirect URIs (example: http://localhost/googleplus/Test.aspx).
  • Click "Create Client ID" and it will create a Client ID detail.
Google-Plus-Authentication-in-ASPNet-3.jpg
  • Redirect URIs and Client ID need to replaced in the Test.aspx file.

ASP.Net application

In the code below, first set your Client ID and Redirect URI. I have provided an example to show the logged in username and profile image, you can use it in any other way also. In the function getUserInfo(), you can get the results as username, email and and so on.

jQuery Link: jQuery.js

  1. <HTML>  
  2.     <Head>  
  3.         <script src="jquery.js" temp_src="jquery.js" type="text/javascript"></script>  
  4.         <script language="javascript" type="text/javascript">  
  5.     var OAUTHURL = 'https://accounts.google.com/o/oauth2/auth?';  
  6.     var VALIDURL = 'https://www.googleapis.com/oauth2/v1/tokeninfo?access_token=';  
  7.     var SCOPE = 'https://www.googleapis.com/auth/userinfo.profile https://www.googleapis.com/auth/userinfo.email';  
  8.     var CLIENTID = '132264420893-na047nu1sif8dn1p6qaug895feu2lqbp.apps.googleusercontent.com';  
  9.     var REDIRECT = 'http://localhost/googleplus/Test.aspx';  
  10.     var LOGOUT = 'http://accounts.google.com/Logout';  
  11.     var TYPE = 'token';  
  12.     var _url = OAUTHURL + 'scope=' + SCOPE + '&client_id=' + CLIENTID + '&redirect_uri=' + REDIRECT + '&response_type=' + TYPE;  
  13.     var acToken;  
  14.     var tokenType;  
  15.     var expiresIn;  
  16.     var user;  
  17.     var loggedIn = false;  
  18.     function login()  
  19.     {  
  20.   
  21.         var win = window.open(_url, "windowname1", 'width=800height=600');  
  22.         var pollTimer = window.setInterval(function () {  
  23.             try  
  24.             {  
  25.                 console.log(win.document.URL);  
  26.                 if (win.document.URL.indexOf(REDIRECT) != -1)   
  27.                 {  
  28.                     window.clearInterval(pollTimer);  
  29.                     var url = win.document.URL;  
  30.                     acToken = gup(url, 'access_token');  
  31.                     tokenType = gup(url, 'token_type');  
  32.                     expiresIn = gup(url, 'expires_in');  
  33.                     win.close();  
  34.                     validateToken(acToken);  
  35.                 }  
  36.             }   
  37.             catch (e)  
  38.             {  
  39.   
  40.             }  
  41.         }, 500);  
  42.     }  
  43.     function validateToken(token)  
  44.     {  
  45.         $.ajax(  
  46.             {  
  47.             url: VALIDURL + token,  
  48.             data: null,  
  49.             success: function (responseText)  
  50.             {        
  51.                 getUserInfo();  
  52.                 loggedIn = true;  
  53.                 $('#loginText').hide();  
  54.                 $('#logoutText').show();  
  55.             },  
  56.             dataType: "jsonp"  
  57.         });  
  58.     }  
  59.     function getUserInfo()   
  60.     {  
  61.         $.ajax({  
  62.             url: 'https://www.googleapis.com/oauth2/v1/userinfo?access_token=' + acToken,  
  63.             data: null,  
  64.             success: function (resp)   
  65.             {  
  66.                 user = resp;  
  67.                 console.log(user);  
  68.                 $('#uName').text('Welcome ' + user.name);  
  69.                 $('#imgHolder').attr('src', user.picture);  
  70.             },  
  71.             dataType: "jsonp"  
  72.         });  
  73.     }  
  74.     //credits: http://www.netlobo.com/url_query_string_javascript.html  
  75.   
  76.     function gup(url, name)  
  77.     {  
  78.         namename = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");  
  79.         var regexS = "[\\#&]" + name + "=([^&#]*)";  
  80.         var regex = new RegExp(regexS);  
  81.         var results = regex.exec(url);  
  82.         if (results == null)  
  83.             return "";  
  84.         else  
  85.             return results[1];  
  86.     }  
  87.     function startLogoutPolling()  
  88.     {  
  89.         $('#loginText').show();  
  90.         $('#logoutText').hide();  
  91.         loggedIn = false;  
  92.         $('#uName').text('Welcome ');  
  93.         $('#imgHolder').attr('src', 'none.jpg');  
  94.     }  
  95.   
  96.     
  97.   
  98. </script>  
  99.     </Head>  
  100.     <body>  
  101.         <a href='#' onClick='login();' id="loginText"'> Google Plus </a>  
  102.         <a href="#" temp_href="#" style="display:none" id="logoutText" target='myIFrame' onclick="myIFrame.location='https://www.google.com/accounts/Logout'; startLogoutPolling();return false;"> Click here to logout </a>  
  103.         <iframe name='myIFrame' id="myIFrame" style='display:none'></iframe>  
  104.         <div id='uName'></div>  
  105.         <img src='' id='imgHolder'/>  
  106.     </body>  
  107. </HTML>