Google OAuth2 acceptable use - google-oauth

I wish to create a single application registered with Google that uses Google's OAuth2 mechanisms to authorize read access to a user's Google Drive content. Then on behalf of that user I want to take that data and expose it via my application as a webservice (proprietary REST API). The webservice can then be consumed by arbitrary 3rd party applications that know nothing about the authorization of my application to access the user's Google Drive.
This is technically possible and not very difficult. My question is whether or not this is an acceptable use of Google's APIs and Google's OAuth2 offering?

OAuth 2 requires an user to affirmatively say yes to your request. As long as you properly describe what you'll do with it (and what is the nature of these third party apps) then I don't see why you can't.
If you just try to slip in the read scope on a generic-looking request form, than I would say that's a no-no.

Related

Do I not need to secure my API endpoints (resources) with OAuth 2 access tokens?

There are multiple partied involved in OAuth2 conversation. Consider the
following diagram from the article here
Consider that I have an application that has data for restaurants and has APIs related to it. Let's call is restaurants APIs. Let us assign some role to each party in context of this example
User - our chefs, who have some recipes in restaurant
Application - Web client written in HTML5, JS, CSS that our Users use to interact with APIs
OAuth Endpoint - Google (who acts as Authorization Server)
API - My application API keeping all data for chefs
The workflow for Implicit (as per above diagram in the link) states the Application gets the access token and then the Application(browser) calls API (my application with chefs recipes) and gets the data back.
Questions
Shouldn't I secure my application endpoints or rather just believe the accesssTokens? Yes, the trust is established between Application and OAuth Endpoint (Google), but there is no trust developed API and Application by confirming the validity of accessToken with OAuth Endpoint (Google)?
If I should secure my application API endpoints, shall I have a /login endpoint for my APIs where my application accepts accessTokens, validate and create a JWT based headers for clients to use for further communication with protected resources like /recipes.
Looking forward to your ideas here.
Thanks in advance
TL;DR - don't blindly trust the access tokens. Ask Google to reveal the user/email associated with them and the client ID that was used when generating them. You can still provide a /login endpoint for scalability purposes mostly.
Let's deal with the core security first
OAuth is a delegation protocol, not an authentication protocol. To quote from the OAuth website:
The OAuth 2.0 specification defines a delegation protocol [...] OAuth is used in a wide variety of applications, including providing mechanisms for user authentication. [...] Let's say that again, to be clear:
OAuth 2.0 is not an authentication protocol.
Because it's not an authentication protocol, your app/API never learns who the user is. It just gets a token. Delegation in this context means that OAuth lets App A request access to resources in App B that belong to a User, by having the User authenticate to App B and then passing the token back to App A. In your example, it can provide your web app with access to Google resources (email, photos, etc. - depending on the required scopes) that are owned by the Users (chefs).
Note that this isn't what you are doing here, since you're accessing resources managed by your app, not by Google. In particular, as you correctly identified, the access token means nothing to your API. I could just as well give it a random string.
You might be tempted to use the following scheme:
Implement the implicit scheme as described in your question.
Have the API server validate the access token with Google, and ask Google for the name or email associated with the token. This will be the identity of the user who actually logged in to Google, and you can then decide whether or not to grant permission to that user.
The problem with this approach is that many apps use OAuth with Google, and so many apps will have Google access tokens that don't belong you app. How can you tell the difference?
You can ask Google, when you present it with the access token, to also provide you with the client ID that was provided when this token was generated (see how your diagram indicates that the client ID is sent?). Since that client ID uniquely identifies your app, then your API can tell that it's been given tokens that only came from your app. Note that this critical part of the OAuth flow is very different in mobile apps which is why the implicit flow should not be used with mobile apps (but it's fine with web apps).
Note that your client ID should be considered common knowledge (e.g. it's found in the .js files on the machines performing this flow), but it cannot be spoofed because as part of the OAuth flow, the user's browser will be redirected to a URL that is pre-configured in Google and belongs to your app. So even if a malicious app uses your client ID, Google will still send the token to your app.
Other practicalities
The above requires you to issue a call to Google on every API call, or at least cache the valid access tokens (which means you keep state, which is a bummer for scalability). If you want to avoid this, you can create a /login endpoint which generates a JWT. Note that you'll still need to validate the access tokens upon login.

Allowing Developer Access tokens for an api secured with Auth0

I have used Auth0 for a while with success, I recently came across a new challenge: allowing external developers to access my API with credentials provided by my web app.
The current system comprises of:
a Web App (not a SPA currently) with Auth0 log in
a back end API with Auth0 api authentication
Currently there is a single client in Auth0. The user logs in on the website and when they call the API via the website the token is passed along in the headers.
My question is: what is the best way to allow developers to request direct access to the api, in a self service manner on my website?
I see two paths forward, either create a client for each developer application via the Auth0 management API (github style), or request a token on behalf of the developer with a VERY long lifespan (like AppVeyor).
I'm assuming that your API provides functionality and/or resources that are associated or owned by an end-user, and you want to allow other application to also access this data on behalf of each end-user. If this isn't the case, and you API is general-purpose and does not require the notion of an end-user identity then other approaches like API keys could also meet your requirements.
Considering the end-user delegation scenario, the approach I would recommend would be going with the creation of separate client applications within Auth0. Like you said, you could automate this process through the Management API so that this process could be handled in a self-service way. Despite being self-service, the application that enabled the registration could still apply constraints in order to make sure only eligible developers could obtain the necessary information to then obtain access tokens to access the API.
This has the benefit that if you wanted to stop an existing developer from using your API you could just remove the associated client application and they wouldn't be allowed to request access tokens anymore and the ones they already had would be short lived and soon expire. This requirement is more complex to implement when using long-lived tokens because they would need to be revoked/blacklisted.
A final note, if these applications don't require to act on behalf an end-user when calling your API and you would prefer to still accept access tokens instead of using a different approach like API keys, then you can consider registering client applications meant to use the client credentials grant.

application authentication API

Iam a student and i making my internship. Sorry for my bad englis
The situation
2 people are building an backend for an message system. There are actual and passed messages. The main backend contains all the data from all the messages. This backend pushes only actual messages to and database from an mini backend which only contains the actual alerts. These actual alerts are provided by an api to multiple front ends such as an app.
I need to do research about api gateways which can make the data in the mini backend accesable for external developers. These developers only need to register or request an account so we know which application/developer connects with our api. We don't have end users with user accounts.
The API need to be scalable because in the future (over a couple of months) this system wil replace an old system. The current system needs to be handle more then 5.000.000 requests in a couple of minutes when sending out an emergency message/alert.
My problem
I googled a lot about authentication methods and i read about OAuth2. This is only necessary for authenticate end users with an user account? I dont have that so OAuth is to complex for my situation i think. But when i look in the documentation of several API Gateways like Mulesoft, Amazon API Gateway and some more i always come back by OAuth and not by an simple authentication token system or something.
See this link and then Creating a client registration flow. This uses OAuth or do i understand this incorrectly?
So now my questions
Is there an default method such as google or facebook uses for authenticate external applications by an API key? and how is this method/framwork/idunno caled?
Is it posible that i can/need to do this with OAuth?
Some example API gateways that can fill in my wishes will be great!
Amazon Api Gateway team here.
Our service supports native API keys which satisfy simple use cases. Are you interested in a simple mechanism to authenticate clients when they access your API? Some limitations would be that it's harder to manage a large number of keys, and there wouldn't really be any authorization to specific backend resources, only authentication to access the API in general.
http://docs.aws.amazon.com/apigateway/latest/developerguide/how-to-api-keys.html
OAuth is better for dynamic user bases where new users register and you want to be able to control access for existing users over time. It is also useful when users have personal data that only they should be able to access.
Jack

How should I use Google APIs in this scenario?

In our company we run a number of different websites which are being tracked with Google Analytics (GA). Up to this point we have been using the Login protocol and GData to access GA data to display the data nicely on our custom web application dash boarded which we use for tracking traffic on our sites.
Nowadays Google has Google API Console which lets you track your API usage. We want to take advantage of this service to view howmuch APIs we consume. However from what we can understand it requires us to use OAuth for authentication instead of the username and password we currently use to access the data. We don't like OAuth because it redirects the user to Google for authentication when currently the user has no need to know about where the data is coming from and what credentials are needed.
Is there anyway that we could make Google API Console monitor our usage without having to switch from GData and the Login protocol?
You can switch to the OAuth 2 protocol and use a refresh token for offline access. Once you get the refresh token, you can save it to a file or database and use that to access the data without an authorization redirect.
See the docs here: https://developers.google.com/accounts/docs/OAuth2InstalledApp#refresh
Also see where there is discussion of using the refresh token: How can we access specific Google Analytics account data using API?

How to authenticate main application when it is OAuth API based

I am starting a new web project and I intend to make it API based; that is I want to build the API first, authenticated via OAuth, then build a website and possibly mobile app(s) that use the API to handle data. I also have my eye on opening up the API to the public.
Here is my issue; I am struggling to get my head around how to authenticate these 'official' apps, the ones made by me, including the main site.
In OAuth the client creates an account for each user then seeks access rights via the resource owner logging in at the main site. This obviously does not work for me because the main site and the client are the same place and it also implies my users should be creating two accounts just to use my website...
I believe twitter uses its own API to run twitter.com and I get the impression that this approach is becoming quite normal so there must be a standard approach.
I must be missing something, but what?
You are confusing the API (business logic) with the authenticaton of user identity (for example logging in), and the authorization of third party apps (OAuth).
It is correct that twitter.com uses their own API. But they don't use OAuth on their own site. When you're on twitter.com, their APIs are available to themselves over cookie authentication. To put it simply: you're logged in.
Once you move away from twitter.com you have to use OAuth. Now an application is using the API on behalf of a user.
To sum up. You don't specifically need OAuth for your "own" web client to use your own APIs. You need OAuth, or some other authorization mechanism, to publish your APIs and it will also come in handy for your own "official" apps.
There is really no need to distinguish your own official apps from third party apps. Not from a technological perspective anyway.
Host two versions of the "API". One mapped to the external domain api.yoursite.com and it OAuth-enabled to authenticate all requests. The other internal version is accessible only within your pool of servers, your official apps. Since only your official apps can access it in the first place, consider all requests to the internal API trusted.
If you want the same application to manage both external and internal calls, you can choose to
distinguish external and internal requests based on incoming IP addresses
implement your API to accept one of "VIP passes" or OAuth tokens for authentications. External apps use OAuth tokens to perform actions on behalf of certain users. Official apps use "VIP passes" to perform actions on behalf of any user.