The Beginner’s Guide to OAuth Dancing
Let’s start with the basics: OAuth stands for Open Authorization. It’s a process through which an application or website can access private data from another website.
This other website usually works only as a trusted identity provider. It gives the requesting app some basic information about you so that they can create a profile. This way, you don’t have to fill in a boring sign-up form and deal with yet another password 📋
You’ve already used this at least a gazillion times, in fact you use it every time you clicked in “Log in with Facebook / Google / GitHub / etc.” You are shown a consent screen displaying which information from your (let’s say) Facebook profile you’re allowing that-hot-new-app.com to read (and sometimes, write!). After that, since that-hot-new-app.com trusts the identity provided by Facebook, they can create a profile for you on their database.
The communication between that-hot-new-app.com and Facebook usually ends here. This is why your profile picture won’t change all across the Internet if you change it on Facebook. They just never go back to Facebook and ask for updated data.
When marimba rhythms start to play…
There’s another purpose for building this kind of mechanism, one with way more potential: using the provider as a service provider. This means communicating with it regularly to supply enhanced features for your users. A nice example of this is Relive, a service that connects with different sports tracking apps to create Earth view videos of your run or ride. Every time you finish an activity, Relive prompts you offering to create a video from it. If you say yes, they’ll process it and notify you when it’s ready for social media bragging… I mean sharing 🏅
There’s really no technical difference between these two usages. That’s why you should be cautious about where you log in with your social media or Google/Gmail account (let’s call it YourFavoriteIdentityProvider).
But don’t be afraid, just bear in mind that you’re authorizing your account to provide that-hot-new-app.com with that information detailed in the consent screen, potentially in a recurrent basis. Be aware of the permissions you grant, and make sure you know how to disable them whenever you don’t feel trusting anymore. For instance, if you are using your Google account for accessing that-hot-new-app.com but don’t want to allow that anymore, just go to https://myaccount.google.com/security#connectedapps and disable their access. All the main identity providers offer control over this.
All right, but how do you dance the OAuth?
Before you land on that-hot-new-app.com and even click on “Log in with YourFavoriteIdentityProvider”, someone, probably a developer, has to create an application on the provider’s site. This is a way of registering that-hot-new-app.com, so that later the provider knows who’s asking for private data.
In this step, the developer will set up some information about the application:
- the application’s name
- the application’s website
- and most importantly: a redirect URI. The provider will use this to tell the requesting app that the user said yes 💍
Once the app is registered, the provider will give that-hot-new-app.com a clientId and a clientSecret which will be used in the communications between them. They work sort of like a username and password for the application.
Apart from that, the developer would have to find out what kind of data does the provider give access to, and how it’s segmented. These “segments” are known as scopes and they define access rights, usually separated in read/write categories. So for example, that-hot-new-app.com can request for “profile:read” and “contacts:read” scopes. This means they can read whatever the provider assigns to the “profile” and “contacts” segments. Other things won’t be visible, for instance, your posts or what content you like.
Well, just to make things simple for now on, let’s say that that-hot-new-app.com is a website that integrates with Typeform. You definitely want in on that, and quick, so on their website you click on “Log in with Typeform” to get right into the action. What’s next?
Here’s a nice diagram to use as a map for the whole thing. It may look a bit complicated but don’t worry, we’ll examine each step up next.
Authorize: the first step in the OAuth dance
So, you take the initiative and click on “Connect with Typeform”. Here, that-hot-new-app.com (THNA from now on, ’cause I’m getting tired of writing dash-separated words) will redirect you to Typeform’s authorize endpoint (/oauth/authorize) and provide:
- their clientId (remember, that’s THNA’s username)
- their desired scopes (or access rights)
- and their redirect URI again (Typeform already knows it, but we send it again as an extra layer of security)
That URL will look something like this:
Typeform will use this information to generate a consent screen where you can review what sort of things you’re authorizing THNA to see and do.
Once you have thoroughly read what you’re consenting to and happily click on “Allow”, Typeform send a temporary code to the redirect URI, like so:
Token: it takes 2 to tangOAuth 💃
All this back and forth feels like someone’s taking you for a tango spin, right?
The second step of the OAuth dance is when THNA receives that code, and exchanges it for an OAuth Token.
So THNA takes that code and sends it back again to Typeform, along with the redirect URI (yes, again!), and the client secret (that’s the app’s password!).
As reward for a dance well danced, THNA will get a shiny OAuth Token ✨ which it can use to interact with Typeform on behalf of the user, that is… you!
Stay with me, sway with me
From now on, in every request THNA makes to Typeform on your behalf they’ll have to include an Authorization header with that access token. With it, Typeform (or any other provider) can identify:
- who’s asking for the data (in this case, THNA)
- who’s the data about (you!)
- and also make sure they have the correct authorization to access that data (only what you consented to).
Ready for the dance floor 👯
So now that you know all the steps and spins of the OAuth dancing technique you should be ready to create your own choreographies, I mean, integrations, and make the Internet an even greater place.
If you have an idea to integrate with Typeform but you don’t really know where to start, make sure you don’t miss our upcoming tutorial for setting up a Node.js app using Typeform’s PassportJS strategy for authentication (or grab a free Node.js Typeform integration boilerplate here!)
Thank you for reading! We are glad to share our experience and help everybody out there to code better.
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