Authentifizierung und Autorisierung

Welcome to Authentication & Authorization in Micro Frontends! Securing federated applications brings unique challenges compared to monolithic apps.

We need robust ways to verify user identities (authentication) and control what they can access (authorization) across independently developed and deployed Micro Frontends.

In a Micro Frontend architecture, users interact with multiple separate applications. If each MFE handled authentication independently, users would face multiple login prompts.

This leads to a poor user experience and complex session management. A centralized authentication mechanism is crucial for seamless navigation.

A common solution is to use an Identity Provider (IdP). This is a service that creates, maintains, and manages identity information for users and authenticates them.

• Examples: Auth0, Okta, Keycloak, or a custom OAuth 2.0/OpenID Connect server.
• The IdP handles the login process and issues security tokens (like JWTs) upon successful authentication.

Here's a simplified centralized authentication flow:

1. User tries to access any MFE.
2. If not authenticated, they are redirected to the central IdP login page.
3. User logs in with the IdP.
4. IdP redirects the user back to the MFE with a security token.
5. The MFE stores this token (e.g., in an HTTP-only cookie or local storage).

All subsequent requests from any MFE will use this token.

Once a user is authenticated, their session or token needs to be available to all Micro Frontends. Common strategies for sharing state:

• HTTP-Only Cookies: Secure and automatically sent with requests.
• Web Storage (localStorage/sessionStorage): Accessible across same-origin domains.
• Shared Libraries/Context: A shared utility that wraps token management, often exposed via Module Federation.

Each method has its trade-offs regarding security and ease of implementation.

While authentication verifies who you are, authorization determines what you can do.

• After authentication, the security token often contains user roles or permissions.
• Each Micro Frontend is then responsible for checking these permissions before granting access to specific features or data.

Role-Based Access Control (RBAC) is a popular authorization strategy. Users are assigned roles (e.g., 'admin', 'editor', 'viewer'), and each role has specific permissions.

Micro Frontends simply check the user's roles against the required roles for a given action or component.

Each Micro Frontend or its backend API can implement authorization checks. This often involves:

• Decoding the security token to extract user roles/permissions.
• Comparing these against the required permissions for a specific action or UI element.

Here's a simple JavaScript example:

Securing your federated applications requires vigilance:

• HTTPS: Always use HTTPS for all communication.
• Token Storage: Store sensitive tokens securely (e.g., HTTP-only cookies over localStorage).
• CORS: Properly configure Cross-Origin Resource Sharing policies.
• Input Validation: Always validate user input on both client and server sides.
• Regular Audits: Perform security audits and keep dependencies updated.

Drag and drop the steps to correctly order a user's initial authentication flow in a federated application using an Identity Provider (IdP).

We've covered the essentials of authentication and authorization in Micro Frontends. Key takeaways:

• Centralized authentication via an Identity Provider ensures a smooth user experience.
• Security tokens (like JWTs) carry authentication and authorization data.
• Strategies like HTTP-only cookies or shared libraries help share authentication state.
• Authorization (e.g., RBAC) dictates what users can do, based on roles/permissions in their token.
• Always follow security best practices like HTTPS and secure token storage.

Next, we'll explore cross-application security risks!