Email Verification Using Azure Functions and MSAL

Improving User Authentication Using Azure Functions and MSAL

JavaScript and Node.js Implementation

const { ConfidentialClientApplication } = require('@azure/msal-node');
const axios = require('axios');
const { json } = require('express');
const express = require('express');
const app = express();
app.use(json());

const msalConfig = {
    auth: {
        clientId: "YOUR_CLIENT_ID",
        authority: "https://login.microsoftonline.com/YOUR_TENANT_ID",
        clientSecret: "YOUR_CLIENT_SECRET",
    }
};

const cca = new ConfidentialClientApplication(msalConfig);
const tokenRequest = {
    scopes: ["user.Read.All"],
    skipCache: true,
};

async function getUserDetails(userEmail, accessToken) {
    const graphEndpoint = \`https://graph.microsoft.com/v1.0/users/\${userEmail}\`;
    try {
        const userResponse = await axios.get(graphEndpoint, { headers: { Authorization: \`Bearer \${accessToken}\` } });
        return { email: userResponse.data.mail, fullName: userResponse.data.displayName };
    } catch (error) {
        console.error('Error fetching user details:', error);
        return null;
    }
}

app.post('/verifyUser', async (req, res) => {
    const { emailToVerify } = req.body;
    const authHeader = req.headers.authorization;
    const accessToken = authHeader.split(' ')[1];
    const userDetails = await getUserDetails(emailToVerify, accessToken);
    if (userDetails && userDetails.email === emailToVerify) {
        res.status(200).json({
            message: 'User verified successfully.',
            fullName: userDetails.fullName
        });
    } else {
        res.status(404).json({ message: 'User not found or email mismatch.' });
    }
});

app.listen(3000, () => console.log('Server running on port 3000'));

Frequently Asked Questions about Azure Functions and MSAL Authentication

1. How does MSAL interact with Azure Functions and what does it do?
2. A library called MSAL (Microsoft Authentication Library) was created to assist developers in user authentication and token access from the Microsoft identity platform. It works with Azure Functions to manage users and validate tokens to secure APIs.
3. Could token refresh scenarios be handled by Azure Functions?
4. Yes, by leveraging MSAL's built-in features to automatically manage token lifecycles, including updating them upon expiration, Azure Functions may be set up to handle token refresh scenarios.
5. How may Azure Functions be secured with MSAL?
6. Function-level authentication must be implemented, the function app must be configured with the proper authentication settings using MSAL, and token validation must occur for every request in order to secure Azure Functions.
7. Which scopes are required in Azure to validate a user's email address?
8. You usually need the `User.view} or `User.ReadBasic.All} scope, which enables the application to view the basic profile of authenticated users, in order to verify a user's email using MSAL and Azure Functions.
9. How do I deal with Azure Functions authentication errors?
10. Try-catch blocks can be incorporated into the function code to capture and react to authentication or API call failures, hence guaranteeing strong error management and response tactics. This allows for error handling in Azure Functions.

Last Thoughts on Azure Functions-Based MSAL Authentication

Robust user verification can be implemented to improve security and streamline user management in applications that use Azure Functions and MSAL. Applications needing trustworthy identity verification to continue operating securely and effectively must use this method. Developers can effectively handle high numbers of authentication requests, manage authentication flows, and give users a seamless, secure experience by integrating MSAL with Azure Functions. This approach is a great option for enterprise situations because it secures apps and fits nicely with contemporary cloud-based architecture.