Integrating Auth0 with Spring Boot

This document outlines the architecture and steps required to integrate Auth0 for authentication and authorization in a Spring Boot application. The focus is on how to configure Auth0, set up Spring Security to use OAuth2/OIDC flows, and leverage Auth0’s role management to drive role-based access control in the application.

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1. Auth0 Application Setup

1.1 Account Creation and Application Registration

• Auth0 Account:
  • Sign up for an Auth0 account if one does not already exist.
• Register a New Application:
  • In the Auth0 dashboard, navigate to the Applications section.
  • Create a new application by providing a meaningful name (e.g., “Facility Management – User Service”) and selecting Regular Web Applications.
  • Select Java (or Spring Boot if available) as the target technology to receive platform-specific guidance and configuration recommendations.

1.2 Configuring Callback URLs

• Callback URL(s):
  • In the application settings, set the Allowed Callback URLs. This is the endpoint Auth0 will redirect users to after successful authentication.
  • Example:

    http://localhost:8080/login/oauth2/code/auth0
    

• Other URL Settings:
  • Configure Allowed Logout URLs and Web Origins as needed for your environment.

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2. Spring Boot Application Configuration

2.1 OAuth2 Client Configuration

• Application Properties:
  • In your Spring Boot project, update the configuration file (application.properties or application.yml) with Auth0 client details such as client ID, client secret, and issuer URI.
  • Define the OAuth2 registration parameters (client ID, client secret, redirect URI, and scopes like openid, profile, email).
  • Ensure the issuer URI is set to your Auth0 domain so that Spring Security can correctly handle OIDC flows.

2.2 Spring Security Integration

• Security Filter Chain:
  • Configure Spring Security to protect application endpoints. Only allow authenticated users to access secured resources.
  • Set up OAuth2 login so that unauthenticated requests redirect users to Auth0 for authentication.
• Custom User Service:
  • Integrate a custom user service (or OIDC user service) that handles the processing of tokens received from Auth0.
  • This service extracts user attributes and custom claims (such as roles) from the token, and it creates or updates user records in your local database accordingly.

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3. Role Management and Custom Claims

3.1 Role Management in Auth0

• Auth0 Dashboard – Roles:
  • Auth0 provides a user management section where roles can be created and managed.
  • Roles such as “ADMIN”, “USER”, or “VICKER” can be defined and assigned to users either manually or via automation.
• Enabling RBAC:
  • In the Auth0 API settings, enable Role-Based Access Control (RBAC) and configure permissions to be included in access tokens. This allows roles to be automatically added to the token.

3.2 Injecting Roles into Tokens

• Custom Claims:
  • Use a custom namespace (e.g., https://yourdomain.com/roles) to store role information. This prevents conflicts with standard OIDC claims.
• Auth0 Actions or Rules:
  • Post Login Actions (Preferred):
    • In Auth0’s Actions section, use the Post Login trigger to add the roles claim to both the ID token and the access token.
  • Legacy Rules (Alternative):
    • If your tenant uses the legacy Rules system, write a rule that appends the roles (from Auth0’s RBAC system or user metadata) to the tokens.
• Outcome:
  • After a successful login, the tokens will include the custom claim that lists the user’s roles. Your Spring Boot application then extracts these roles to enforce authorization policies.

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4. Testing and Verification

4.1 OAuth2 Flow Testing

• Initiate Login:
  • Test the OAuth2/OIDC flow by navigating to the designated login URL (e.g., /oauth2/authorization/auth0). This triggers a redirect to Auth0 for authentication.
• Callback Handling:
  • After successful authentication, Auth0 will redirect the user back to your application’s callback endpoint, where the token exchange is processed.

4.2 Token Inspection

• Verify Custom Claims:
  • Use tools such as jwt.io or browser developer tools to inspect the tokens returned by Auth0.
  • Confirm that the token contains the custom roles claim (e.g., "https://yourdomain.com/roles": ["ADMIN"]).

4.3 Local User Synchronization

• User Record Management:
  • Ensure that the custom OIDC user service in your Spring Boot application creates or updates the local user record with the correct details and role information.
• Endpoint Verification:
  • Access a protected endpoint (e.g., /users/me) to validate that the authentication and role mapping work as expected. The endpoint should return the current user’s details along with their assigned roles.

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