application authentication API - 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

Related

Mobile authentication approaches, JWTs and refresh tokens

Context
I'm developing togther with my dev team a mobile app in a client-server architecture, since there will be a webclient too, allowing some users (admins) to perform certain operations from the browser.
The REST Api currently authenticates users by returning access and refresh tokens in form of JWTs. Both local (username/password) and OAuth2.0 (only Google at the moment) flows are available, as I provide the user with these two different options for authenticating.
Problem
The flows that follow are working just fine when the API is called from the webclient, but now that we've started developing the mobile app a big question arised: **how do we keep the user authenticated on the mobile app even after the refresh token expires?**
All the famous apps out there do not prompt the user to authenticate let's say weekly or worst daily, but still I'm sure their authentication practices are (almost) flawless.
Tried paths
I've read many blog posts and articles, together with some StackExchange Q&As as reported below, but the right way to approach authentication and access persistence on mobile is still unclear.
Should I create a specific endpoint (or many) to provide non-expiring tokens only when the User-Agent header tells the API is being called by a mobile device?
As mentioned in JWT (JSON Web Token) automatic prolongation of expiration Auth0 abandoned JWT for mobile in favor of random generated strings. What implementations are available in this case? Should I use this string as a never-ending id of the authenticated device and approve all API calls that have it attached?
In the OAuth case, should I perform (I don't know how) silent calls to the OAuth provider to get back a new idToken and then request new tokens to my own API with it?
In the local case, should I keep user credentials stored locally? If so, how do I do that securely?
Consulted resources
What's the right OAuth 2.0 flow for a mobile app
JWT refresh token flow
Authenticating a mobile application with JWT and refresh tokens
https://softwareengineering.stackexchange.com/questions/318471/jwt-refresh-token-exponentially
https://auth0.com/docs/best-practices/mobile-device-login-flow-best-practices
https://auth0.com/blog/refresh-tokens-what-are-they-and-when-to-use-them/
https://mobile-security.gitbook.io/mobile-security-testing-guide/general-mobile-app-testing-guide/0x04e-testing-authentication-and-session-management
https://tech.justeattakeaway.com/2019/12/04/lessons-learned-from-handling-jwt-on-mobile/ (more focused on improving an already established architecture)
...and many more I'm not reporting as outside the scope of the question.
This question was originally posted here, https://softwareengineering.stackexchange.com/questions/430302/mobile-authentication-approaches-jwts-and-refresh-tokens/430315#430315
Some diagrams
These are the flows we've currently implemented, working as espected when the API is consumed by a webclient.
Local
OAuth2.0
I don't think the requirement is well formed and it feels like it is based on a sweeping statement from product owners, without considering costs v benefits:
Gmail keeps me signed in forever and I want my app to work like that
LARGE PROVIDERS
The likes of Google often use bespoke solutions around analyzing user patterns, periodically getting 2 factor confirmation and other actions that would be very expensive for normal companies.
OAUTH
For normal software companies the problem has been solved via OAuth and the AppAuth pattern. Curity Guides provide a good starting point if you are not familiar with it:
Once coded you can use many authentication options with zero code changes in your UIs and APIs
User friendly password-less options such as WebAuthn are supported
You can even support advanced options such as App2App Logins if needed
Mobile code and the architecture remains simple in all cases
USER CONSENT
Note also that OAuth is built around users agreeing to the app using their details for a period of time. I often stop and think if I am abusing this - and what would be the impact if a user's device was stolen - not sure how relevant this is for your scenario ...
MIDDLE GROUND
For most companies I would recommend this type of option so that usability is good:
Start with a user friendly option such as 30 day refresh tokens
If you are using password logins, ensure that password autofill works - AppAuth will enable this
TOKENS
These are issued by an Authorization Server (AS) not developed by you. Think of this as a Docker Container that provides HTTPS endpoints - use a free or low-cost one.
The motivation behind the Auth0 point you mentioned is explained well in this article. The mobile app just sends access tokens to APIs. There is no token issuing in your code and it remains simple.
SUMMARY
Prefer industry standard proven options with good cost v benefit results. OAuth is highly architectural though and there is a learning curve which your company needs to manage.

API Authentication for multiple apps

I have been doing a lot of research into how to authenticate mobile apps with an API - I still feel a bit unsure about which flow & architecture would be better to use in my particular use case.
I think what's confusing me is some of the terminology used.
My use case:
An API & database on one server. Which holds the users & and the users resources.
A web app, which I have built and consumes the API. Hosted on the same server as the API. So it's dogfooding.
A web app, which I have built and consumes the API. Hosted on a different server to the API.
A mobile app, which I have built and consumes the API.
I'd like to be able to authenticate with the API using username & password.
The API will never be opened up for consumption by other 3rd party services except the web app and the mobile app.
Initially I felt like using the Resource Owner Password Credentials Grant flow would be sufficient. However in the docs it states that this flow should be used if "The client is absolutely trusted with the user credentials".
Since both my mobile & web apps will be built by me, I'm assuming they are seen as 1st party clients. Therefore am I right in thinking they are considered to be trusted with the user credentials? As I typically thought that when implementing oAuth, the idea would be to have the authentication server separate from the resource server. Which would allow you to have one authentication server for multiple APIs.
After reading this post: Why the Password Grant is not suitable for modern applications
It threw me off track a bit. But then, is this post talking about using this flow in my use case?
I was also looking at the Implicit Grant Tokens flow. However using this flow I couldn't really see how the user would enter their credentials first?
I also question if any of the oAuth flows is really needed for my use case and I should instead look at other ways of authenticating?
I'm really quite lost with this I would like some direction to go in with how to authenticate users in my particular case.
Thanks in advance!
I'll most likely be using Laravel to house my API and so I do have Passport available to me to implement oAuth
EDIT
From following this oauth article I've found that in all use cases of my app, I end at Password Credentials Grant flow. Would I be correct here?

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.

Mobile app with api authorisation access

I'm creating a mobile app for customers that need to access an api that I use.
The api requires authentication and the app needs to call the api to receive some data that is specific to each individual customer(mobile app).
I just want to make sure that the right way to do this is for the mobile app to send the query to my server which will then make the authenticated api call and return the response to the mobile client?
or is it possible to have the mobile make the api calls directly, presumably using the same authorisation key?
This is primarily an opinion-based question, however I'll give it a go:
[paraphrased] Can my server act as an API proxy to make authenticated calls to another API on behalf of my unauthenticated users?
This is a common occurrence in the API world, but some things you need to consider:
It's an extra layer in between the user and the service, which adds time to the data transport. Make sure you build your proxy to be scalable or use a 3rd party service that can manage that on your behalf. Either way, don't forget to factor in cost.
Usually service providers require authentication for a reason. Are you violating any license agreements by opening up their API like this?
Is the authentication per-application, or per-user? If it's per-user (e.g. each user logs in and retrieves a unique access_token) then you're going to be making calls to the back-end API as a user instead of an application.
Is the destination API rate-limited? Instagram's API, for example, only allows 5000 requests per hour. If you have 10,000 users that use it once per hour, you'll have already hit that limit.
Are there security concerns opening up the destination API like this? Is there sensitive information that you need to protect? If so, opening it up like you do are you creating security holes?
Is it possible to have the mobile make API calls directly to the target API, presumably using the same authorization key?
Absolutely this is possible - provided that you follow the authentication flow established by the target API. You'll want to consider the same list of concerns listed above though, in addition to:
If you're using an auth flow like OAuth2, the standard dictates that each user should authenticate as themselves and make API calls using a unique access_token. Does your target API provider offer this service? If so, that's the way to go, that way if an access_token is compromised, only that user's data/account/etc. is at risk.
If you're using app-level authentication (e.g. your app's client_id and client_secret) directly in your mobile app, be warned that it can be obtained and compromised with little effort, and thus an attacker could gain access to the entire target API this way.

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.