RBAC from ACL: A Step-by-Step Guide

TL;DR

This guide shows you how to move from Access Control Lists (ACLs) to Role-Based Access Control (RBAC). It’s about making managing permissions easier and more secure by grouping users into roles instead of setting individual permissions.

Step 1: Understand the Difference

Before we start, let’s quickly recap ACL vs RBAC:

• ACL: Each resource (file, folder, etc.) has a list saying who can do what. It gets messy fast as you add more users and resources.
• RBAC: You define roles (e.g., ‘Admin’, ‘Editor’, ‘Viewer’). Users are assigned to these roles, and roles have permissions. Much easier to manage!

Step 2: Define Your Roles

Think about what people in your organisation *do*, not who they *are*. Common roles include:

• Admin: Full access to everything.
• Editor: Can create, modify, and delete content.
• Viewer: Read-only access.
• Contributor: Can create new content but not edit existing ones.

Write down a clear description of what each role can do.

Step 3: Map Existing ACLs to Roles

This is the most time-consuming part. Go through your current ACLs and figure out which roles they correspond to:

• For each user, list all the resources they have access to and what actions they can perform.
• Identify common permission sets – these will become your roles.
• If a user has permissions that don’t fit neatly into any existing role, consider creating a new one or modifying an existing one.

Step 4: Implement RBAC in Your System

How you do this depends on your system (operating system, application, database). Here are some examples:

Linux/Unix

You might use groups to represent roles. For example:

sudo groupadd admin

sudo usermod -aG admin username

Then, set file permissions based on the group:

chmod 750 filename; chown :admin filename

Databases (e.g., PostgreSQL)

Create roles and grant privileges:

CREATE ROLE editor;

GRANT SELECT, INSERT, UPDATE ON mytable TO editor;

GRANT editor TO username;

Applications

Most applications have built-in RBAC features. Look for settings related to ‘Roles’, ‘Permissions’, or ‘User Groups’. Configure these according to the roles you defined in Step 2.

Step 5: Test, Test, Test!

This is crucial. Make sure users can only do what their role allows:

• Log in as different users with different roles.
• Try to perform actions they shouldn’t be able to do (e.g., an Editor trying to delete a system file).
• Verify that users *can* perform the actions their role allows.

Step 6: Remove Old ACLs

Once you’re confident RBAC is working correctly, carefully remove your old ACLs. This reduces complexity and potential security issues.

Step 7: Ongoing Maintenance

RBAC isn’t a one-time task:

• Regularly review roles to ensure they still reflect the needs of your organisation.
• When new users join, assign them to appropriate roles.
• If requirements change, update roles accordingly.