Custom JAX-RS authorization - using JWT in each request

Solution 1:

You can perform this logic in a ContainerRequestFilter. It pretty common to handle custom security features in here.

Some things to consider

1. The class should be annotated with @Priority(Priorities.AUTHENTICATION) so it is performed before other filters, if any.

2. You should make use of the SecurityContext, inside the filter. What I do is implement a SecurityContext. You can really implement it anyway you want.

Here's a simple example without any of the security logic

@Provider
@Priority(Priorities.AUTHENTICATION)
public class SecurityFilter implements ContainerRequestFilter {

    @Override
    public void filter(ContainerRequestContext requestContext) throws IOException {
        SecurityContext originalContext = requestContext.getSecurityContext();
        Set<String> roles = new HashSet<>();
        roles.add("ADMIN");
        Authorizer authorizer = new Authorizer(roles, "admin", 
                                               originalContext.isSecure());
        requestContext.setSecurityContext(authorizer);
    }

    public static class Authorizer implements SecurityContext {

        Set<String> roles;
        String username;
        boolean isSecure;
        public Authorizer(Set<String> roles, final String username, 
                                             boolean isSecure) {
            this.roles = roles;
            this.username = username;
            this.isSecure = isSecure;
        }

        @Override
        public Principal getUserPrincipal() {
            return new User(username);
        }

        @Override
        public boolean isUserInRole(String role) {
            return roles.contains(role);
        }

        @Override
        public boolean isSecure() {
            return isSecure;
        }

        @Override
        public String getAuthenticationScheme() {
            return "Your Scheme";
        } 
    } 

    public static class User implements Principal {
        String name;

        public User(String name) {
            this.name = name;
        }

        @Override
        public String getName() { return name; }   
    }
}

A few things to notice

• I've created a SecurityContext
• I've added some roles, and used them for the isUserInRole method. This will be used for authorization.
• I've created a custom User class, that implements java.security.Principal. I returned this custom object
• Finally I set the new SecurityContext in the ContainerRequestContext

Now what? Let's look at a simple resource class

@Path("secure")
public class SecuredResource {
    @GET
    @RolesAllowed({"ADMIN"})
    public String getUsername(@Context SecurityContext securityContext) {
        User user = (User)securityContext.getUserPrincipal();
        return user.getName();
    }
}

A few things to notice:

• SecurityContext is injected into the method.
• We get the Principal and cast it to User. So really you can create any class that implements Principal, and use this object however you want.

• The use of the @RolesAllowed annotation. With Jersey, there is a filter that checks the SecurityContext.isUserInRole by passing in each value in the @RolesAllowed annotation to see if the User is allowed to access the resource.

  To enable this feature with Jersey, we need to register the RolesAllowedDynamicFeature

  @ApplicationPath("/api")
  public class AppConfig extends ResourceConfig {
  
      public AppConfig() {
          packages("packages.to.scan");
          register(RolesAllowedDynamicFeature.class);
      }
  }
  

Solution 2:

I was searching for an solution which is Jersey independent and works for Wildfly -> found this github example implementation:

https://github.com/sixturtle/examples/tree/master/jaxrs-jwt-filter

It should give you a hint how to solve it clean.

Implement a JWTRequestFilter which implements ContainerRequestFilter https://github.com/sixturtle/examples/blob/master/jaxrs-jwt-filter/src/main/java/com/sixturtle/jwt/JWTRequestFilter.java

as stated above and register the filter as resteasy provider in web.xml:

<context-param>
       <description>Custom JAX-RS Providers</description>
       <param-name>resteasy.providers</param-name>
       <param-value>com.sixturtle.jwt.JWTRequestFilter</param-value>
</context-param>
<context-param>
        <param-name>resteasy.role.based.security</param-name>
        <param-value>true</param-value>
</context-param>