Spring Boot Oauth2 SSO (legacy stack) - spring-boot

I have one Spring Boot application (application A) with Oauth2 (Legacy stack - Authorization + Resource Server). I want to enable user on second app (application B) to be able to use said application if he is logged in on app A (SSO). If I understood correctly, I need to use authorization_code flow to get authorization code in app B so I can exchange it with access token (app B client communication with app A auth server). The problem is, I don't know how to use the access token on the client B side, how should I enable access to endpoints to the user who has access token. I tried using #EnableResourceServer but I don't know how to get an authentication based on access token. From what I read, I would need an introspection URI pointing to the app A auth server, but I don't know how to get said URI.
Is the #EnableResourceServer the solution, and if so, what is required for authentication to be loaded? Should I be using something else like #EnableOAuth2Sso or OauthClient in my app B?
Edit: I am using opaque tokens.

Related

how do I design my authenticated requests and my frontend

i am currently working on a project where my backend uses Spring Boot, Spring security + keycloak and runs on localhost:8081.
My frontend (svelte) runs on http://127.0.0.1:5173/ and the url http://127.0.0.1:5173/products needs to access data from localhost:8081/products (which needs a login) but the login page from keycloak doesnt appear.
In other words, what i am trying to achieve:
I want that the url http://127.0.0.1:5173/products redirects to localhost:8081/products which redirects to keycloak login page and after a successfull login i want to return to http://127.0.0.1:5173/products where i will be able to see the data.
is there an elegant solution to this problem? Im really stuck on this problem and this is one of my first projects.
Thanks in advance!!
Some OAuth2 wording:
Keycloak is an authorization-server (OIDC complient)
Svelte app is a client
Spring REST API is a resource-server
Ensure that a "public" client is declared in Keycloak.
Configure your Svelte client with an existing OIDC lib (component) of your choice to:
use the "public" client deckared in Keycloak
authenticate users against Keycloak (socket is not the same as spring API)
add an authorization header with a JWT access-token retrieved from Keycloak (when issuing requests to your secured REST endpoints)
Configure Spring API as a secured resource-server with a JWT decoder.
You can refer to this article for configuring Keycloak and resource-server with JWT access-tokens.

custom oidc in keycloak

I have a spring based application which does authentication and authorization(oauth2 based) for a client app.I want to now use keycloak to manage my authorizations, but i want to keep my spring code. Basically i want to use my existing auth code as an external identity provider in keycloak.
I am thinking of adding changes in client app such that it receives token from my existing oauth code(which does the authentication) and then exchange this token with keycloak(for session and authorization management). How can i do this? What configurations need to be done in keycloak?
I read about token exchange in keycloak here, but i am not clear about the kind of token i need to send from my existing auth code.
https://www.keycloak.org/docs/latest/securing_apps/
Here is how OAuth2 roles are usually spread:
Keycloak is authorization-server
Spring service is resource-server
front-end is client
user is resource-owner
I have a doubt of you wanting your Spring service to be "authorization-server" as well (serve user identity). If so, I think you should not.
Keycloak (or any other OpenID provider) should be the only authorization-server. Both Spring and client(s) should be configured to use it as so.
To write it differently, Keycloak is responsible for users login and emitting tokens with user ID (subject) and rights (roles or whatever). Other tiers in the architecture (clients & resource servers) get user info from the token and apply relevant security checks (spring security annotations, Angular guards, etc.).
I published a mono-repo for a meetup with minimal sample involving a Spring resource-server and Angular (with Ionic) client talking to a Keycloak OpenID authorization-server. You might find some inspiration browsing it.

Authorization Server Endpoints

As we know the Spring Security OAuth 2.0 project has bee depreciated and now it's Spring Security 5.
My question is related with Authorisation Server for grant_type: authorization_code. Spring team is also working on standalone project for Authorization Server. So most of the codebase in Spring Security project is depreciated for Authorization Server.
Still, I've couple of questions for endpoints with authorization_code flow in Spring Security 2.0/5.
OAuth 2.0:
Can you please let me know, which endpoints are supported for below use cases in Authorization Flow:
Login Button: ask the customised authorization url from Authorization Server.
User logged-in: once end-user logged-in (authenticate), need to authorise with registered client application and provide the code in the callback URI.
Request For Access Token: once the code has been received in previous step, it should use the code to get the access token.
Please let me know which endpoints are meant to be used in Spring Security OAuth 2.0/5 for above use cases. Based on my research, I've found these endpoints:
/oauth/token: get the access token
/oauth/token_key: produces JWT encoded token values
/oauth/check_token: validate the access token
Can you please let me know which endpoint dedicated for authorisation before end-user authenticate in use case #1. And after end-user authentication in use case #2.
Any help would be appreciated.
Many Thanks,
Adnan

Resource Owner Password Credentials with Spring Boot

I have a legacy desktop application that communicates with a Spring Boot server (latest version 2.2.2.RELEASE). I'm using OAuth2 for authentication (provided by spring-boot-starter-oauth2-client). I want to avoid changing the client because is a legacy application. It is capable of collecting the credentials and start the session via HTTP Basic Authentication, and then keep the cookies for the session in the following requests.
Given this scenario, I think best option is to make use the OAuth2 Resource Owner Password Credentials grant. With this, we can exchange the collected credentials by the OAuth2 Tokens. We have two options:
Option 1:
Modify the client application to use the access tokens via the Authorization header. This will require to make an initial call to the Authorization Provider to exchange the collected credentials by the tokens.
Option 2:
Keep using the Spring session and store the information about the OAuth client in the server.
I found this project ALMOST does that: https://github.com/jgrandja/spring-security-oauth-5-2-migrate. It has a client (messaging-client-password) defined with authorization-grant-type: password which will activate the OAuth2 Resource Owner Password Credentials grant in Spring Boot.
It creates an OAuth2 client and stores its information in the session, then Spring is able to use that client in further requests. The problem with this project is it seems to only work as when the OAuth client is used to make HTTP requests (e. g. an endpoint that makes a call to another service) and not provide authentication to the controller. You can find more information about this in here:
Spring Security 5.2 Password Flow
Github related issues: link1, link2, link3
Exception thrown when we try to use the password client as authentication
The natural idea to overcome this is to implement a proxy and use the OAuth2 client in the requests. Well, Spring already offers a proxy solution, the Spring Cloud Gateway. But I don't know to accomplish that with this setup.
Any insights? Am I thinking correctly or should I follow a different approach?

How one can use other oauth2 providers like FB, Google in an existing jwt authentication system

I am new to spring boot and trying to implement oauth2 client with facebook as oauth2 provider.
I already have a traditional JWT token authentication in place which is configured with in #EnableWebSecurity with default authentication manager and custome JWT token generator.
is it really required to configure AuthorizationServer and
ResourceServer in above scenario?
if not then why my code always returns me only Code and state from facebook to call back URL.
Please have a look into the code here
Oauth2 = Authorization delegation protocol NOT an authentication one.
If you want to use FaceBook and Google as identity provider then you must go with an identity federation protocol, ie OpenId Connect (OIDC).
This last add an authentication layer (using JWT id token) above oauth2 authorization layer.
Regarding more specifically your question (which is not very clear) about the spring security configuration part , it seems that the current oauth2 server implementation (AuthorizationServer and ResourceServer you're talking about are part of it) is not suitable as it is to implement an OIDC identity provider)
Regarding the code and state returned to the callback URL, it's part of the oauth2 authorization code flow and it's perfectly normal, you then have to exchange the retrieved code against an access token using the authorization server token endpoint.
(state is just here to allow to transmit an information for example a tenant id, across the oauth2 whole flow).
Here is really well written oauth2 vulgarization article.

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