JWT and Spring Security - spring

Question

I've built a REST Service using Spring Boot and Spring Security for authentication. I'm pretty new to both Spring Boot and Spring Security. I've made one authentication module in one JAR file. The front end client sends a request with username and password to the authentication module. The authentication module then authenticates the user's details against a DB. A JWT is created and then sent back to the client if the authentication is successful. The username and role is coded into the JWT. The JWT is then used to verify the user when resources are requested from the other REST Service endpoints that are built in separate JAR files. There are a few things I'm not sure about.
In Spring Security is there one authentication object created for each user so that several users can be authenticated at the same time or is one authentication done each time and only one user can be logged in?
How long is the authentication object in valid? Should I "logout"/remove the authentication successful when the JWT has been created in the authentication module or will it take care of it itself when the request is done? For the resource endpoints (not the authentication endpoint) is there a way to set authentication successful in the authentication object once I've verified the JWT? Similarly can I set the role in the authentication object once the JWT has been verified?
I've based my code on this example https://auth0.com/blog/securing-spring-boot-with-jwts/. I've split it into different JARs for authentication and verification of the JWT (I'm doing verification in resource endpoint). I've also added JDBC authentication instead of in memory authentication.

Answer 1

In Spring Security is there one authentication object created for each
user so that several users can be authenticated at the same time or is
one authentication done each time and only one user can be logged in?
Of course multiple users can be authenticated at the same time!
How long is the authentication object in valid? Should I
"logout"/remove the authentication successful when the JWT has been
created in the authentication module or will it take care of it itself
when the request is done?
You write your service is REST, and if you want to stay "puritan" REST you should configure the authentication to be stateless, which means that the Authentication object is removed when the request has been processed. This does not affect the validity of the JWT token, you can set an expiry of JWT token if you want.
How to make REST stateless with "Java config":
#Configuration
public static class RestHttpConfig extends WebSecurityConfigurerAdapter
{
#Override
protected void configure(HttpSecurity http) throws Exception
{
http
.sessionManagement()
.sessionCreationPolicy(SessionCreationPolicy.STATELESS);
// and the rest of security config after this
For the resource endpoints (not the authentication endpoint) is there
a way to set authentication successful in the authentication object
once I've verified the JWT? Similarly can I set the role in the
authentication object once the JWT has been verified?
I use code similar to below after verification of the token:
Collection<? extends GrantedAuthority> authorities = Collections.singleton(new SimpleGrantedAuthority("ROLE_JWT"));
Authentication authentication = new PreAuthenticatedAuthenticationToken(subject, token, authorities);
SecurityContextHolder.getContext().setAuthentication(authentication);
By constructing the authentication object with at least one role (authority), it is marked as "successful" (authenticated).