Use native Google Account Picker with B2C

Using the Native Google Account Picker with B2C

This article will guide you through integrating the native Google Account Picker with your Azure Active Directory B2C (Azure AD B2C) application. This approach offers a seamless user experience, providing users with the familiar Google sign-in flow.

Understanding the Approach

The native Google Account Picker is a simple JavaScript snippet that lets you prompt the user to choose a Google account. However, it does not directly authenticate the user. Instead, it provides the user’s email address, which can then be used to perform subsequent steps like:

• Signing up for your B2C application.
• Logging into an existing account.

Steps for Implementation

1. Setting Up Azure AD B2C

• Create a B2C tenant: If you haven’t already, create a B2C tenant within your Azure subscription.
• Register an application: Register an application in your B2C tenant to represent your application.
• Create user flows: Design user flows for sign-up, sign-in, and profile editing using the B2C portal.
  • Enable social identity providers for Google and configure the necessary settings.

2. Implementing the Google Account Picker

Use the following code snippet to embed the Google Account Picker within your application:

<button id="google-sign-in">Sign in with Google</button>
<script>
  function handleGoogleSignIn(googleUser) {
    const email = googleUser.getBasicProfile().getEmail();
    // Submit email to your server for B2C authentication
    // ...
  }
  
  function init() {
    gapi.load('auth2', function() {
      gapi.auth2.init({
        client_id: 'YOUR_GOOGLE_CLIENT_ID.apps.googleusercontent.com',
      }).then(auth2 => {
        auth2.attachClickHandler('google-sign-in', {}, handleGoogleSignIn, function(error) {
          // Handle errors
        });
      });
    });
  }
  
  // Load the Google API client library
  (function() {
    var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true;
    po.src = 'https://apis.google.com/js/platform.js';
    var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s);
  })();
</script>

3. Handling User Email

When the user selects their Google account from the picker, you’ll get their email address in the googleUser object. Send this email to your backend server for further processing, such as:

• Sign-up: Create a new B2C user with the provided email.
• Sign-in: Initiate the B2C sign-in process by sending the email as a parameter to the relevant endpoint.

Server-Side Integration

On the server side, you’ll need to handle the user’s email address and authenticate with B2C.

1. Sending Email to B2C

Implement an endpoint in your application’s backend to receive the user’s email from the frontend. This endpoint will be responsible for initiating the B2C sign-up or sign-in process.

2. B2C Authentication

Depending on your chosen user flow, you’ll either create a new user or initiate a sign-in flow. In both cases, you will need to communicate with B2C using its API.

Example: Node.js Backend with Express

const express = require('express');
const app = express();
const port = process.env.PORT || 3000;

// Example endpoint for handling user email
app.post('/google-sign-in', (req, res) => {
  const email = req.body.email;
  
  // Initiate B2C authentication (sign-up or sign-in)
  // ... 
  
  res.send('Email received for B2C processing.');
});

app.listen(port, () => {
  console.log(`Server listening on port ${port}`);
});

Comparison: Native Google Account Picker vs. Google Sign-In

Conclusion

Using the native Google Account Picker alongside Azure AD B2C can provide a seamless and familiar login experience for your users while leveraging the power of B2C for user management.