how do I design my authenticated requests and my frontend - spring-boot

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.

Related

OAuth in Spring security question to get userInfo

My application has frontend build with angular and backend build with spring boot, and I use openam by Forgerock as an authentication server. I got the access_token in frontend and pass this access_token to backend through Bearer authentication, But now I have to check if the token is valid in backend by calling /userInfo endpoint. My question is how to config in spring boot to call this endpoint everytime when get the request? Thanks
I may case I didn't had any explicit configuration for access token. You just have to call end points and the tokens will be stored in the header for authentication. Though you can set the timer for it.

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.

Keycloak authentication flow in a microservices based environment

I want to use Keycloak in a microservices based environment, where authentication is based on OpenID endpoints REST calls ("/token", no redirection to keycloak login page), a flow that I thought of would be something like this:
1. Front-end SPA retrieves the tokens from the "/token" endpoint and stores in browser's localStorage, then sends it with every request.
2. Gateway-level authentication: Acess Token is passed from the front end to the gateway, gateway consults Keycloak server to check if the token is still valid (not invalidated by a logout end-point call).
3. Micro-service based authorization: Acess Token is passed from the Gateway to the microservices, using Spring Boot adapter the microservices check the signature of the token offline (bearer-only client?) then based on the role in the token do the authorization.
My questions are: Does this flow make sense or can you suggest another flow? What type of Keycloak clients to use? What's an ideal way to pass Tokens using Spring Boot Adapter, and should it be done like that in the first place? Please keep in mind that I am not a Keycloak expert, I've done my research but I still have doubts.
Your Front-end SPA should be public-client and springboot micro service should be Bearer only Client and Gateway could be Confidential Client.
You can check the Keycloak provided oidc adapters. For springboot you use the keycloak provided adapter
Similar solution using api gateway is discussed here

How does the authorization rules are validated by keycloak authorization server using spring rest adapter

I have set up the keycloak server and created the spring rest application with keycloak rest adapters. The Authorizations rules are working fine.
I would like to know about the internal working of the keycloak spring boot rest adapter. How the logged in user's token is validated against policy and permission set in keycloak admin client.
You are correct, access token does not contain all these details.
In Keycloak when you are using server side adapters the client will be configured to use the standard flow and not the implicit flow of OIDC.
In standard flow when you login using keycloak IDP your front-end redirects to Keycloak IDP and asks for you credentials. If you have the right credentials login is successful and you are redirected back to your app. In this redirect your app gets a code which it then sends to the back-end rest call. This code is used by spring adapter in the spring boot app to make a call to Keycloak IDP server and it is this call in which the boot application will get the user context to take all the authorization decisions as a response from the Keycloak server.
Hope this makes sense.

Keycloak: Spring Boot project as bearer and reusing token from user

I am building an application with an angular frontend and spring boot on the backend. I was able to configure the angular and spring part.
So, the frontend requests a token and sends it with every request to the java backend. This works just fine.
My java backend is now in the need to reuse the client token to request data from another service, which uses the same mechanism.
What is the right way to go forward? Requesting an own token for my service or using the existing token from the authenticated user?
I have not found a way to do this.
Works as pointed out by ravthiru
While calling your 3rd service you can use the same token , Add your third service as bearer-only Client.

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