Google OAuth2 in external window Asp.Net Core - asp.net-core

Question

I'm trying to implement google oauth external authorization to happen in external browser window. My code looks like below:
$('#signinButton').click(function () {
window.auth2.grantOfflineAccess()
.then(signInCallback)
.catch(error => console.log(error));
});
function start() {
gapi.load('auth2', function () {
window.auth2 = gapi.auth2.init({
client_id: 'CLIENT_Id'
});
});
};
function signInCallback(authResult) {
if (authResult['code']) {
var authCode = authResult['code'];
$.ajax({
type: 'POST',
url: '/Auth/GooglePostredirect',
data: authCode,
headers: {
'X-Requested-With': 'XMLHttpRequest'
},
contentType: 'application/octet-stream; charset=utf-8',
success: function (result) {
},
processData: false,
});
} else {
}
};
And the question is after getting authToken, how i should call google api to get user info by auth token. Is there any handy libraries for that? I can't find any to request userInfo by token from c#.
Thanks you all in advance!

Answer 1

You can use Google.Apis.Auth library from nuget package manager, and get info from google token, which you get from your front-end
public async Task<IActionResult> ExternalLoginGoogleAsync(string googleTokenId)
{
GoogleJsonWebSignature.ValidationSettings settings = new GoogleJsonWebSignature.ValidationSettings();
settings.Audience = new List<string>() { Configuration["Authentication:Google:ClientId"] };
GoogleJsonWebSignature.Payload payload = await GoogleJsonWebSignature.ValidateAsync(googleTokenId, settings);
ApplicationUser user = await _userManager.FindByEmailAsync(payload.Email);
if (user == null) //create new user if not exsits
{
user = new ApplicationUser
{
Email = payload.Email,
UserName = payload.Name
};
...
}
return Ok(something);
}