Two-Factor Authentication with Authy, PHP and Laravel

Adding Two-Factor Authentication (2FA) to your web application increases the security of your user's data by requiring something your user has to be present for step-up transactions, log-ins, and other sensitive actions. Multi-factor authentication determines the identity of a user by validating once by logging into the app, and then by validating their mobile device.

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

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 Client app or
• Sending them a token through their mobile Authy app or
• Sending them a one-time token in a text message.

See how VMware uses Twilio Two-Factor Authentication to secure their enterprise mobility management solution.

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

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

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

Register 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.

Log 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.

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.

Send 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.

Configure 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.

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.

Disabling Unsuccessful Callbacks

Scenario: The OneTouch callback URL provided by you is no longer active.

Action: We will disable the OneTouch callback after 3 consecutive HTTP error responses. We will also

• Set the OneTouch callback URL to blank.
• Send an email notifying you that the OneTouch callback is disabled with details on how to enable the OneTouch callback.

How to enable OneTouch callback? You need to update the OneTouch callback endpoint, which will allow the OneTouch callback.

Visit the Twilio Console: Console > Authy > Applications > {ApplicationName} > Push Authentication > Webhooks > Endpoint/URL to update the Endpoint/URL with a valid OneTouch callback URL.

Handle 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.

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.

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

Where to next?

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

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