Two-Factor Authentication with Authy, Ruby and Sinatra

This Sinatra 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 first by logging into the app, and second 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 via text message sent with Authy via Twilio.

See how VMware uses Authy 2FA to secure their enterprise mobility management solution.

Configure 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 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 store our new user into the database and will register the user with Authy.

All Authy needs to get a user set up for your application is the 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.

Having registered our user with Authy, we then can use Authy's OneTouch feature to log them in.

Log in with Authy OneTouch

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

OneTouch works like this:

• We attempt to send a OneTouch Approval Request to the user.
• 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.

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 don'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.

"message" => "Request to Send Money to Jarod's vault",
"details['Request From']" => "Jarod",
"details['Amount Request']" => "1,000,000",
"details['Currency']" => "Galleons",

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

Once we send the request we need to update our user's AuthyStatus based on the response. But first we have to register a OneTouch callback endpoint.

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.

Note: In order to verify that the request is coming from Authy, we've written the helper method authenticate_request! that will halt the request if it appears it isn't coming from 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.

Our application is now capable of using Authy for two-factor authentication. However, we are still missing an important part: the client-side code that will handle it.

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.

Finally, we can confirm the login.

Finish 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 auth using three different methods and the latest Authy technology.

Where to Next?

If you're a Ruby developer working with Twilio, you might enjoy these other tutorials:

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Click-To-Call

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