Authorization

You've successfully authenticated a user, verifying their identity. Now, it's time to determine what that user is allowed to do. This is where authorization comes in. Authorization answers the question: "What are you allowed to access?"

Think of authorization as checking your ticket at the entrance to a specific section of a concert venue. Just because you have a ticket doesn't mean you can access every area.

The Authorization Process

After a user has been authenticated, the application needs to determine whether they have the necessary permissions to access a particular resource or perform a specific action. The authorization process typically involves the following steps:

1. User Requests Access: The user attempts to access a resource or perform an action (e.g., view a document, update a profile, delete a record).
2. Server Checks Permissions: The server checks the user's permissions to determine whether they are authorized to access the requested resource or perform the requested action.
3. Access Granted or Denied: Based on the user's permissions, the server either grants access to the resource or denies the request.

Common Authorization Models

There are several common authorization models:

• Role-Based Access Control (RBAC): A widely used authorization model that assigns permissions to roles and then assigns users to those roles.
  • Pros: Simple to implement and manage.
  • Cons: Can become complex to manage in large organizations with many roles and permissions.
  • Example:
    • Define roles such as "admin," "editor," and "viewer."
    • Assign permissions to each role (e.g., "admin" can create, read, update, and delete resources; "editor" can read and update resources; "viewer" can only read resources).
    • Assign users to roles based on their job function.
• Attribute-Based Access Control (ABAC): A more flexible and granular authorization model that controls access based on attributes of the user, the resource, and the environment.
  • Pros: Highly flexible and can be used to implement complex authorization policies.
  • Cons: More complex to implement and manage than RBAC.
  • Example:
    • Allow access to a document only if the user's department is the same as the document's department, the user's security clearance is high enough, and the current time is within the document's validity period.
• Access Control Lists (ACLs): A mechanism for granting or denying specific permissions to individual users or groups for specific resources.
  • Pros: Provides fine-grained control over access to resources.
  • Cons: Can be difficult to manage and scale, especially for large numbers of users and resources.
  • Example:
    • A file system that allows you to specify which users or groups have read, write, or execute permissions for each file or directory.

Implementing Authorization

Here's a general outline of how to implement authorization in your back-end code:

1. Retrieve User Information: After authenticating the user, retrieve their roles, permissions, or attributes from the database or a session store.
2. Check Permissions: Based on the authorization model you're using, check whether the user has the necessary permissions to access the requested resource or perform the requested action.
3. Grant or Deny Access: If the user is authorized, grant access to the resource or allow the action to proceed. Otherwise, deny the request and return an appropriate error message (e.g., 403 Forbidden).

Authorization and APIs

When designing APIs, it's important to consider how authorization will be handled. Some common approaches include:

• API Keys: Assign unique API keys to each client and require them to include the API key in every request.
• OAuth 2.0: Use OAuth 2.0 to allow users to grant third-party applications limited access to their API resources.
• JWT (JSON Web Tokens): Include user roles and permissions in the JWT and verify the JWT's signature and claims on every request.

Remember

Authentication verifies who a user is, while authorization verifies what they are allowed to do. Choose an authorization model that matches your application's complexity and security needs. Implement authorization checks throughout your application, from APIs to database queries.