What is the proper way to identify a user in an API call?
I'm using the Auth0 service to secure my API and manage user authentication/sign up process. I "think" I'm clear about two things:
access_token gives the client app proper access to my backend API. In other words, I need to send an access_token with my API call to my backend so that I can access my API end points.
The primary purpose of id_token is to provide the backend API information about the user e.g. id, name, email, etc.
Assuming I'm right about these two points, how do I let the backend API know who the user is? I don't think I can send both access_token and id_token in the same call. Am I then making two calls?
I can certainly include user information in my API call payload but would that not be a security concern? Potentially a malicious user could change the user info before the API call and present himself/herself as someone else.
I'm unclear about the way of letting the backend API know who the user is.
P.S. Here's more info in case it's needed:
All user authentication, sign up and tokens are handled by the Auth0 service.
My backend API is created in ASP.NET Core and is configured to accept Auth0
tokens. This is working fine i.e. I send the access_token I get from Auth0 in my API calls and I'm able to access my end points.
I'm now developing a mobile app in ReactNative which authenticates users through Auth0 and calls my ASP.NET Core backend API for all the functionality it provides
I agree with Sam's concerns and my preference is to keep access tokens small and confidential - containing just a user id that the API can read.
For further info I use claims in the API using this pattern, which is also commonly used by API gateways - such as AWS:
https://authguidance.com/2017/10/03/api-tokens-claims/
If it helps here is a .Net Core class that implements it.
I've created a FeathersJS backend app and a React frontend app. I'm using OAuth2 strategy to authenticate users to my own WordPress site. Everything is working fine. But now I'd like the users to be able to access my FeathersJS backend REST API, but as they authenticate through the WordPress OAuth2 server, thus following all the OAuth2 authentication process through my React frontend app, which would be the correct FeathersJS way to allow the users authenticate to my backend so that they can do REST API calls?
But now I'd like the users to be able to access my FeathersJS backend REST API
To let people access your backend REST API (which I assume is only possible after they authenticate), you need to check whether the access token they have is, in fact, valid with the third party auth provider.
You can directly let them use the back end API. In case the API doesn't find a valid access token with the incoming request, it will redirect it to the login page. After which, now the backend can validate itself with third-party OAuth provider and return the result.
following all the OAuth2 authentication process through my React frontend app
It is recommended to not do all the OAuth check from front-end since this exposes the access-token on the user agent, which might be a serious issue. See this:
https://www.digitalocean.com/community/tutorials/an-introduction-to-oauth-2#grant-type-implicit
I'm new to Auth0 and having real trouble wrapping my head round it. My app is going to be built using React, packaged using Phonegap.
Am I able to use Auth0 with a completely custom UI for creating accounts, logging in etc.?
Ideally my signup flow would be...
User Signs up using my react form
Details are sent to my API and then passed to Auth0
Success message is received from Auth0 and the user is mirrored in my local DB
My ideal login flow would be...
User fills in email/password on my custom form.
Details sent either directly to Auth0 or via my API
Token is sent back and stored in localStorage
Then each request to my API...
React attaches token to every request in header (actually Axios interceptor does)
My API is able to verify that the token is valid and not expired
API performs request.
Not sure how to deal with social logins, claims etc. but that's for another day, basically I want to do everything through the API and not use their lock screen etc. Is this possible?
Yes! That is definitely possible and to achieve this you would want to use 'Resource Owner Password' grant type.
Once you collect the credentials from user in your custom form, you can directly pass those to Auth0 by calling an endpoint - 'https://yourapplication.auth0.com/oauth/token' with all the necessary parameters. You can make a simple POST request to this endpoint from you client application. For ease of use, there is a javascript library provided by Auth0 for all of their endpoints- (https://auth0.com/docs/libraries/auth0js/v9).
Auth0 will return a token which can be used to call your server side APIs by passing it to the request header.
So to conclude, you can do it through API without using their lock screen.
Let me know if you need any further help. We can discuss on social logins and claims also.
For the past 10+ days I've read an watched ALL the content I could find on understanding OAuth2 and OpenID Connect, only to find that many people disagree on the implementation, which really confuses me.
To my understanding, all the articles and examples I found assume you want access to eg. google calendar, profile info or emails if you eg. login with google, but I do NOT need to access other than my own API's - I only want to use Google, Facebook etc for logging in, and getting an id which I can link to my user in my own database - nothing more than that.
I'll try illustrate my use case and use that as an example.
A note on the diagram: the Authentication service could probably be built into the API Gateway - not that i matters for this example, since this is not about "where to do it", but "how to do it the best way" possible, for an architecture such as mine, where it's used for my own API's / Microservices, and not accessing Google, Facebook etc. external API's
If you can understand what I'm trying to illustrate with this diagram above, please tell me if I've misunderstood this.
The most basic requirements for this architecture you see here are:
Users can login with Google, Facebook, etc.
The same login will be used for all micro-services
OpenId user will have a linked account in the database
User access is defined in my own db, based on groups, roles and permissions
I do not intend to use external API's after the user is authenticated and logged in. No need for ever accessing a users calendar, email etc. so I really just need the authentication part and nothing else (proof of successful login). All user access is defined in my own database.
So a few fundamental questions comes to mind.
First of all, is OpenID Connect even the right tool for the job for authentication only (I'll have no use for authorization, since I will not need read/write access to google / facebook API's other than getting the ID from authenticating)?
People generally do not agree on whether to use the ID or Access token for accessing your own API's. As far as I understand the ID token is for the client (user-agent) only, and the access token is for eg. accessing google calendar, emails etc.... External API's of the OpenID Provider... but since I'll only be accessing my own API's, do I event need the access token or the ID token - what is the correct way to protect your own API's?
If the ID token is really just for the client, so it can show eg. currently logged in user, without going to the DB, I have 0 use for it, since I'll probably query the user from from the db and store it in redux for my react frontend app.
Dilemma: To store user details, groups, roles and permission inside JWT or not for API authorization?
By only storing the user identifier in the token, it means that I always allow authenticated users that has a valid token, to call endpoints BEFORE authorization and first then determine access based on the db query result and the permissions in my own database.
By storing more data about the user inside the JWT, it means that in some cases, I'd be able to do the authorization / access (group, role, permission) check before hitting the API - only possible with user info, groups, roles and permission stored inside a JWT issued upon login. In some cases it would not be possible due to eg. the CMS content access permissions being on a per-node level. But still it would mean a little better performance.
As you can see on the diagram I'm sending all API requests through the gateway, which will (in itself or with an authentication service) translate the opaque access token into some JWT with an identifier, so I can identify the user in the graph database - and then verify if the user has the required groups, roles and permissions - not from an external API, but from my own database like you see on the diagram.
This seems like a lot of work on every request, even if the services can share the JWT in case multiple services should need to cross call each other.
The advantage of always looking up the user, and his permissions in the db, is naturally that the moment the user access levels change, he is denied/granted access immediately and it will always be in sync. If I store the user details, groups, roles and permission inside a JWT and persist that in the client localstorage, I guess it could pose a security issue right, and it would be pretty hard to update the user info, groups, roles and permissions inside that JWT?
One big advantage of storing user access levels and info inside the JWT is of course that in many cases I'd be able to block the user from calling certain API's, instead of having to determine access after a db lookup.
So the whole token translation thing means increased security at the cost of performance, but is is generally recommended and worth it? Or is it safe enough to store user info and groups, roles, permissions inside the JWT?
If yes, do I store all that information from my own DB in the ID Token, Access token or a 3rd token - what token is sent to the API and determines if the user should be granted access to a given resource based on his permissions in the db? Do I really need an access token if I don't need to interact with the ID providers API? Or do I store and append all my groups, roles, permissions inside the ID token (that doesn't seem clean to me) issued by OpenID connect, and call the API and authorize my own API endpoints using that, even if some say you should never use the ID token to access an API? Or do I create a new JWT to store all the info fetched from my database, which is to be used for deciding if the user can access a given resource / API endpoint?
Please do not just link to general specs or general info, since I've already read it all - I just failed to understand how to apply all that info to my actual use case (the diagram above). Try to please be as concrete as possible.
Made another attempt to try and simply the flow:
The following answer does only apply for a OpenID Connect authentication flow with a 3rd party IDP (like Google). It does not apply for an architecture where you host your own IDP.
(There are some API gateways (e.g Tyk or Kong) which support OpenID Connect out of the box.)
You can use JWTs (ID token) to secure your APIs. However, this has one disadvantage. JWTs cannot be revoked easily.
I would not recommend this. Instead you should implement an OAuth2 authorization server which issues access tokens for your API. (In this case, you have two OAuth2 flows. One for authentication and one for authorization. The ID and access token from the IDP are used only for authentication.)
The following picture shows a setup where the API gateway and authentication/authorization server are two separate services. (As mentioned above, the authentication/authorization can also be done by the API gateway.)
The authentication flow (Authorization Code Grant) calls are marked blue. The authorization flow (Implicit Grant) calls are marked green.
1: Your web app is loaded from the app server.
2a: The user clicks on your login button, your web app builds the authorization URL and opens it. (See: Authorization Request)
2b: Because the user hasn't authenticated and has no valid session with your authorization server, the URL he wanted to access is stored and your authorization server responds with a redirect to its login page.
3: The login page is loaded from your authorization server.
4a: The user clicks on "Login with ...".
4b: Your authorization server builds the IDP authorization URL and responds with a redirect to it. (See: Authentication Request)
5a: The IDP authorization URL is opend.
5b: Because the user hasn't authenticated and has no valid session with the IDP, the URL he wanted to access is stored and the IDP responds with a redirect to its login page.
6: The login page is loaded from the IDP.
7a: The user fills in his credentials and clicks on the login button.
7b: The IDP checks the credentials, creates a new session and responds with a redirect to the stored URL.
8a: The IDP authorization URL is opend again.
(The approval steps are ignored here for simplicity.)
8b: The IDP creates an authorization and responds with a redirect to the callback URL of your authorization server. (See: Authentication Response)
9a: The callback URL is opened.
9b: Your authorization server extracts the authorization code from the callback URL.
10a: Your authorization server calls the IDP's token endpoint, gets an ID and access token and validates the data in the ID token. (See: Token Request)
(10b: Your authorization server calls the IDP's user info endpoint if some needed claims aren't available in the ID token.)
11a/b: Your authorization server queries/creates the user in your service/DB, creates a new session and responds with a redirect to the stored URL.
12a: The authorization URL is opend again.
(The approval steps are ignored here for simplicity.)
12b/+13a/b: Your authorization server creates/gets the authorization (creates access token) and responds with a redirect to the callback URL of your web app. (See: Access Token Response)
14a: The callback URL is opened.
14b: Your web app extracts the access token from the callback URL.
15: Your web app makes an API call.
16/17/18: The API gateway checks the access token, exchanges the access token with an JWT (which contains user infos, ...) and forwards the call.
A setup where the authorization server calls the API gateway is also possible. In this case, after the authorization is done, the authorization server passes the access token and JWT to the API gateway. Here, however, everytime the user infos change the authorization server has to "inform" the API gateway.
This is a very long question. But I believe most can be summarised by answering below,
To my understanding, all the articles and examples I found assume you want access to eg. google calendar, profile info or emails if you eg. login with google,
You do not necessarily use Access token (ID token in some occasions) to access the services offered by token issuer.You can consume tokens by your own APIs. What these Identity Providers (synonym to Authorization server, or IDP in shorthand) is to hold identities of end users. For example, typical internet have a Facebook account. With OAuth and OpenID Connect, the same user get the ability to consume your API or any OAuth/OIDC accepted service. This reduce user profile creation for end users.
In corporate domain, OAuth and OIDC serves the same purpose. Having a single Azure AD account lets you to consume MS Word as well as Azure AD's OIDC will issue tokens which can be used to Authorise against an in-house API or an third party ERP product (used in organization) which support OIDC based authentication. Hope it's clear now
A note on the diagram is that the Authentication service could probably be built into the API Gateway - not sure if that would be better?
If you are planning to implement an API gateway, think twice. If things are small scale and if you think you can maintain it, then go ahead. But consider about API managers which could provide most of your required functionalities. I welcome you to read this article about WSO2 API manger and understand its capabilities (No I'm not working for them).
For example, that API manager has built in authentication handling mechanism for OAuth and OIDC. It can handle API authentication with simple set of configurations. With such solution you get rid of the requirement of implement everything.
What if you can't use an API manager and has to do it yourself
OpenID Connect is for authentication. Your application can validate the id token and authenticate end user. To access APIs through API Gateway, I think you should utilise Access token.
To validate the access token, you can use introspection endpoint of the identity provider. And to get user information, you can use user-info endpoint.
Once access token is validated, API gateway could create a session for a limited time (ideally to be less or equal to access token lifetime). Consequent requests should come with this session to accept by API gateway. Alternatively, you can still use validated access token. Since you validated it at the first call, you may cache for a certain time period thus avoiding round trips to validations.
To validate user details, permission and other grants, well you must wither bind user to a session or else associate user to access token from API gateway at token validation. I'm also not super clear about this as I have no idea on how your DB logic works.
First Appreciate your patience in writing a very valuable question in this forum
we too have same situation and problem
I want to go through ,as images are blocked in our company in detail
Was trying to draw paralles to similar one quoted in the book
Advance API In Practise - Prabath Siriwerdena [ page 269]Federating access to API's Chapter. Definitely worth reading of his works
API GW should invoke Token Exchange OAUTH2.0 Profile to IDP [ provided the IDP should support TOken Exchange profile for OAUTH 2.0
The Absence of API Gateway , will result in quite bespoke development
for Access Control for each API Check
you land up in having this check at each of the api or microservice [ either as library which does work for you as a reusable code]
definitely will become a choking point.]
For my current work project we're trying to use OAuth to secure a mobile API, but the app doesn't have user accounts, so authentication would take place invisibly from the user, where the app will send up some secrets to the server and receive the token to be used for subsequent web service calls. The problem is, all the libraries and tutorials I can find implementing OAuth follow this pattern:
Present a web view allowing a user to login
Receive a callback to a custom URL scheme, and parse the necessary information to authenticate future web service calls
How do I achieve this without the webview step? I should be able to make an HTTP request directly with the correct credentials which will return the necessary authentication details.
The app will use OAuth 2.0
It is not clear what do you mean by
the app doesn't have user accounts
If you want to call some API on behalf of user you should ask him for a password. Doing it in webview or not depends on provider implementation. For example, twitter doesn't force you to do that.
In other case, if you want to call service on behalf of client, take a look at this answer: https://stackoverflow.com/a/7477112/2283405
If the app doesn't require "personalised" or "user-specific" data to be manipulated, then you can probably try using "client-credentials" grant type to obtain access tokens using the application credentials granted upon the application registration process by the Authorisation Server (for e.g.: OAuth server) that's there in your environment. The idea is that, your app is what basically authenticates with the Authentication Server for you using the aforesaid credentials (i.e. Client Consumer Key and Client Secret Key).
NO, you have to do login compalsary. if you try without. it won't be possible.