Two-Factor Authentication with Authy

Learn to implement two-factor authentication (2FA) in your web app with Twilio-powered Authy. 2FA helps further secure your users' data by validating more than just a password. This tutorial will show you the code to make it happen.

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About this application

This PHP Laravel sample application is an example of typical login flow. To run this sample app yourself, download the code and follow the instructions on GitHub.

Adding two-factor authentication (2FA) to your web application increases the security of your user's data. Multi-factor authentication determines the identity of a user by validating once by logging into the app, and then by validating their mobile device.

For the second factor, we will validate that the user has their mobile phone by either:

  • Sending them a OneTouch push notification to their mobile Authy app or
  • Sending them a token through their mobile Authy app or
  • Sending them a one-time token in a text message sent with Authy via Twilio. Here's how this works at a high level:

2FA High Level

Let's get started! Click the right arrow above to move to the next step of the tutorial.

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Configuring Authy

If you haven't configured Authy already now is the time to sign up for Authy. Create your first application naming it as you wish. After you create your application, your "production" API key will be visible on your dashboard:

Authy Dashboard

Once we have an Authy API key we register it as a environment variable.

Let's take a look at how we register a user with Authy.

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Registering a User with Authy

When a new user signs up for our website, we will call this route. This will save our new user to the database and will register the user with Authy.

In order to set up your application, Authy only needs the user's email, phone number and country code. In order to do a two-factor authentication, we need to make sure we ask for this information at sign up.

Once we register the User with Authy we get an authy id back. This is very important since it's how we will verify the identity of our User with Authy.

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Logging in with Authy OneTouch

When a User attempts to log in to our website, we will ask them for a second form of identification. Let's take a look at Authy's OneTouch verification first.

Authy OneTouch Approval

OneTouch works like this:

  • We attempt to send a User a OneTouch Approval Request.
  • If the User has OneTouch enabled we will get a success message back.
  • The User hits Approve in their Authy app.
  • Authy makes a POST request to our app with an approved status.
  • We log the User in.

In the next steps we'll look at how we handle cases where the User does not have OneTouch, or denies the login request.

Sending the OneTouch Request

When our User logs in we immediately attempt to verify their identity with OneTouch. We will fallback gracefully if they don't have a OneTouch device, but we won't know until we try.

Authy allows us to input details with our OneTouch request, including a message, a logo and so on. We could easily send any amount of details by appending details['some_detail']. You could imagine a scenario where we send a OneTouch request to approve a money transfer.

$params = array(
  'message' => "Request to send money to Jarod's vault",
  'details[From]' => "Jarod",
  'details[Amount]' => "1,000,000",
  'details[Currency]' => "Galleons",

Once we send the request we need to update our User's authy_status based on the response.

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Configuring the OneTouch callback

In order for our app to know what the user did after we sent the OneTouch request, we need to register a callback endpoint with Authy.

Authy OneTouch Callback

Here in our callback, we look up the user using the authy_id sent with the Authy POST request. Ideally at this point we would probably use a websocket to let our client know that we received a response from Authy. However for this version we're going to keep it simple and just update the authy_status on the User.

Let's take a look at the client-side code that will be handling this.

Handling Two-Factor in the Browser

We've already taken a look at what's happening on the server side, so let's step in front of the cameras and see how our JavaScript is interacting with those server endpoints.

When we expect a OneTouch response, we will begin by polling /authy/status until we see an Authy status is not empty. Let's take a look at this controller and see what is happening.

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Finishing the 2FA Step

If authy_status is approved the user will be redirected to the protected content, otherwise we'll show the login form with a message that indicates the request was denied.

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Where to next?

That's it! We've just implemented two-factor auth using three different methods and the latest in Authy technology.

If you're a PHP developer working with Twilio, you might want to check out these other tutorials.

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Did this help?

Thanks for checking this tutorial out! If you have any feedback to share with us, we'd love to hear it. Contact the Twilio Developer Education Team to let us know what you think.