OpenAM - Use OAuth2 Access Token to get User Details? - oauth

Is it possible to get user details (attributes belonging to the resource owner) from ForgeRock's OpenAM using an OAuth 2 access token?
I have a trusted SPA UI that is able to get an access token from OpenAM using the Resource Owner Password Credentials Grant type. However, that access token gives me no information about the resource owner. The token_info endpoint similarly gives me no information.
OpenAM seems to have endpoints for listing user attributes, but expects a JWT as means of authentication for the request.
How can I get user attributes from an access token?

There is a userinfo endpoint that will return user attributes. In OpenAM 13.0, the data returned by the endpoint is scriptable. In prior versions it is mapped to scopes.
The sample client application is helpful to understand how this works:
https://github.com/ForgeRock/openid

Related

Why we need OIDC ID Token?

I'm researching to use OIDC for SSO (Single Sign On).
I know OIDC flow always return id_token and access_token but I don't know why we need id_token?
As I know id_token used only by client application to get authenticated user information. Client application will decode and verify JWT then extract user information from it.
But because I have access_token, I can use it to get user information from endpoint /userinfo. So I dont't need id_token?
Please help me understand the right way to use id_token.
You are correct that you can get the user details using the access token from the /userinfo endpoint.
The ID-token represents details about the user and more important how the user authenticated (password, 2FA...). The lifetime of the Id-token is often very short (like a few minutes).
Just like how the specification describes it:
The ID Token is a security token that contains Claims about the Authentication of an End-User by an Authorization Server when using a Client, and potentially other requested Claims.

OIDC, OAuth2.0 and role of access token when OAuth client application and resource server are not different

I am working on the ASP.NET MVC 5 web application. It has only one layer which contains views as well as business logic/operations. Business logic is logically separated from UI but it is not behind a separate web service/API layer.
Now when I use OIDC and OAuth2.0 for my application, there is no separate Resource Server, so to say. Because Client itself has all the Resources I want to have access to.
I am using Authorization Code Flow for authentication & authorization.
Questions:
Does access token have any role in this case? If yes, what?
How am I going to practically use the access token? Since the client itself is the resource server, there is nothing to which I need to send access token to.
I guess you get an ID token which contains all the information you need for authentication of a user. If not, you can use the access token to get the user info. If this is all the information you need, then the access token is not needed anymore. This happens, because OAuth2 is a permission delegation protocol, not an authentication protocol in a first place.
When you have the user info, you can implement between the browser and your ASP.NET backend in any way. You can take a look at the OAuth 2.0 for Browser-Based Apps RFC.
In this case you should use Client Credential flow instead of Authorization Code flow.
In Client Credential flow, your application would send your client id & client secret to Authorization Endpoint directly and asking for access token. Authorization Code is not needed in Client Credential flow. Details as below
An authorization code flow typically need your client redirect
resource owner to authorization endpoint and get a authorization
code from authorization endpoint, client than uses this code to get
access token, at the end of the day client uses access token to
access protected resource.
In Client Crendential flow. your client app is actually the owner of
your resource. So no need to asking for a authorization code. direct
uses its own client credential to get access token from
authorization endpoint and use that access token to access protected
resource(Resource server)

Using access_tokens and id_tokens together Auth0

While starting to integrate auth0, I came across this article
So its clear that to secure apis, all we need is the access_token and that is sent with each http request in the request Authorization header(Bearer scheme).
But then auth0(and possibly other providers) also send an Id_token that contains information about the user. My confusion is that how do I use this id_token to pass user information to my api. ( I have a spa running front end that authenticates to auth0 and gets these 2 tokens).
I can ofc call the userInfo end point in my api to get user info. But then wouldn't this defeat the purpose of the Id tokens?
The ID Token is consumed by the application and the claims included,
are typically used for UI display. It was added to the OIDC
specification as an optimization so the application can know the
identity of the user, without having to make an additional network
requests.
So my question is how do I access user profile in my api using id tokens?
"My confusion is that how do I use this id_token to pass user information to my api"
for that confusion, you just pass your JWT token. while generating JWT token, you need to add user information in payload part in JWT token. When your api get the JWT token, just check your JWT token is correct or not by the use of secret key and if correct, you can get data. How to get is just go from that JWT Authentication for Asp.Net Web Api
ID token is sent from the authorization server as a part of OIDC protocol. The purpose of this is to authenticate the user to your client application (SPA in this case). i.e. to let your API or the application know which particular user authorized the client to access a certain resource on its behalf.
Best way to use the ID token is by decoding and verifying it using a library. This will allow you to verify the signature of the token and any other claim that is included in the token (you can add custom claims to the tokens). Validation of those claims can be used to determine identity of the user and match with the user profile in your API. You will have to check the documentation related to your IdP(auth0) to figure out how to add new claims that are used by the user profile in your API.

Google open id connect

I'm trying to secure my endpoint using open Id connect. Currently there is only a mobile app client. With Google as the Identity provider, I have Id_token and access_token.
My question is can I use this access token returned as a part of authentication to authorize user to access my endpoint?
If yes, Is there a way to validate the access token within my server?
Or Should I create an access token for the user and store the same, so that when the user requests, I will check in the DB/Redis ?
OpenID connect is an Authentication layer on top of the "Authorization" framework OAuth 2.0. So the Access Token is the "Authorization" for the OAuth Client to access the resource.
Perhaps this post may help.
As #jwilleke mentioned, OAuth2.0 doesn't specify a way in which an access token can be validated with Authorization server.
Hence the approach that I took was to verify the JWT Id token by checking the signature of it and storing the access token returned along with it.

Clarification on id_token vs access_token

I'm building a system with OIDC and OAuth 2.0 (using Auth0), and I'm unsure how to properly use the id_token and access_token. Or rather, I'm confused about which roles to assign to the various services in my setup.
I have a fully static frontend-application (single-page app, HTML + JS, no backend) that ensures that the user is authenticated using the implicit flow against Auth0. The frontend-application then fetches data from an API that I am also building.
Now, which is right?
The frontend SPA is the OAuth client application
My API service is an OAuth resource server
...or:
The frontend and my API service are both the client application
If both my frontend and backend API can be considered to be the client, I see no real harm in using the id_token as the bearer token on requests from my frontend to my backend - this is appealing because then I can simply verify the signed token on the backend, and I have all the information about the user that I need. However, if my API is considered a resource server, I should probably use the access_token, but then I have to connect to Auth0's servers on every API request to both verify the token, and get basic user info, won't I?
I've read this which seems to suggest that the access_token is the only valid token for use with my API. But like I said, I'm not sure about the roles of the individual services. And using the id_token is tempting, because it requires no network connections on the backend, and contains information I need to extract the right data.
What is the right way to go about this?
I like this Medium post about the difference, all cred to this author.
https://medium.com/#nilasini/id-token-vs-access-token-17e7dd622084
If you are using Azure AD B2C like I am you can read more here:
https://learn.microsoft.com/en-us/azure/active-directory-b2c/openid-connect
ID Token
You will get id token if you are using scope as openid. Id token is specific to openid scope. With openid scope you can get both id token and access token.
The primary extension that OpenID Connect makes to OAuth 2.0 to enable End-Users to be Authenticated is the ID Token data structure. The ID Token is a security token that contains Claims(claims are name/value pairs that contain information about a user) about the Authentication of an End-User by an Authorization Server when using a Client, and potentially other requested Claims. The ID Token is represented as a JSON Web Token (JWT)
{
"iss": "https://server.example.com",
"sub": "24400320",
"aud": "s6BhdRkqt3",
"nonce": "n-0S6_WzA2Mj",
"exp": 1311281970,
"iat": 1311280970,
"auth_time": 1311280969,
"acr": "urn:mace:incommon:iap:silver"
}
The above is default JWT claims, in addition to that, if you requested claims from service provider then you will get those as well.
An id_token is a JWT, per the OIDC Specification. This means that:
identity information about the user is encoded right into the token
and
the token can be definitively verified to prove that it hasn't been
tampered with.
There's a set of rules in the specification for validating an id_token. Among the claims encoded in the id_token is an expiration (exp), which must be honored as part of the validation process. Additionally, the signature section of JWT is used in concert with a key to validate that the entire JWT has not been tampered with in any way.
Access Tokens
Access tokens are used as bearer tokens. A bearer token means that the bearer (who hold the access token) can access authorized resources without further identification. Because of this, it's important that bearer tokens are protected. If I can somehow get ahold of and "bear" your access token, I can pretend as you.
These tokens usually have a short lifespan (dictated by its expiration) for improved security. That is, when the access token expires, the user must authenticate again to get a new access token limiting the exposure of the fact that it's a bearer token.
Although not mandated by the OIDC spec, Okta uses JWTs for access tokens as (among other things) the expiration is built right into the token.
OIDC specifies a /userinfo endpoint that returns identity information and must be protected. Presenting the access token makes the endpoint accessible.
http://openid.net/specs/openid-connect-core-1_0.html
https://connect2id.com/learn/openid-connect#cool-id-token-uses
https://developer.okta.com/blog/2017/07/25/oidc-primer-part-1
Your frontent is your OAuth client application, once it stores the token it can take actions on the OAuth flow. And your API service is resource server, because it accepts the access_token issued by your identity server.
Also I would say that your id_token stands for the identification of the logged user and may contain sensitive data for your app. The access_token is standing as your credential to access a resource.
At the end you will use an access_token to request a resource, and then if you need specific data from the logged in user (resource owner), you may request the ID token from the token endpoint.
In my opinion, the first approach is correct. Your SPA is the client application and your APIs are resource servers.
I would suggest you limit the use of id_token till your SPA only. You can use the basic information present in the id token (like username and email) to display user information within your UI. If you can generate access tokens as JWTs too then your API can validate the access tokens without going to the Identity provider. You can include roles (or similar) in your access token to get authorization information in your access token.
I was also wondering if I need to talk to the IdP on every request if I'm using the tokens received from the IdP. I ended up with the following setup:
Only the backend talks to the IdP, the frontend does not.
Upon the IdP callback the backend issues a JWT for the frontend.
User session and frontend-backend communication is managed entirely by my app using the JWT token.
Check this article: OAuth2 in NestJS for Social Login (Google, Facebook, Twitter, etc)
and this repo: https://github.com/thisismydesign/nestjs-starter
and this question: OAuth2 flow in full-stack NestJS application
The id_token is an cryptographically encoded token for authentication. The OP (the auth provider) is the one that generates it and the RP (relying party or the resource) will eventually re-present the token to the OP to counter validate when handed over by the client. In short the id_token is tied to authn workflow.
The access_token enables resource access. It does subsume the userinfo i.e., the id_token or any other principal on whose behalf the access is being requested. So this token includes both user claims plus claims to groups that are authorized. In short the access_token is tied to your authz workflow.

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