What’s the difference between RBAC and ABAC in Fauna?

ABAC (Attribute-Based Access Control) is not an extension of RBAC (Role-Based Access Control), but rather a distinct model that can be considered a superset regarding flexibility and granularity. They both answer the question, “Does this operation have access,” but use very different mechanisms to determine the answer. Here’s how they compare and relate:

Role-Based Access Control (RBAC):

• Role-centric: Access decisions are primarily based on the static roles assigned to users. Each role has predefined permissions that determine what the bearer of that role can access.
• Simplicity and manageability: RBAC is generally simpler to implement and manage because it categorizes permissions by broad roles, which can be easily assigned to users.
• Static: The rules are static and don't typically consider the context of a request or the attributes of the resources being accessed.

Attribute-Based Access Control (ABAC) in Fauna:

• Attribute-centric: ABAC uses a variety of attributes (user attributes, resource attributes, action attributes, and contextual attributes) to make access decisions. These attributes can encompass various data points pertinent to enforcing access control policies. This includes personal user information such as age and location, organizational roles assigned to the user, and broader system-level conditions like the time of day or the device being used for access. Each attribute can be dynamically assessed to make real-time decisions about the user’s permissions within the system.
• Dynamic and granular: Policies in ABAC can be very granular and context-sensitive, allowing for more precise control over who can access what, when, and under what conditions.
• Flexibility: Due to its reliance on multiple attributes for making decisions, ABAC can accommodate more complex scenarios than RBAC. It can adapt to a range of changing conditions, which would be more difficult or cumbersome to manage in a purely role-based model.

Relationship between RBAC and ABAC:

• While RBAC is focused on user roles, ABAC uses roles as just one of the many attributes it uses for access control. This means ABAC can implement all the policies that RBAC can, plus additional policies that are too specific or dynamic for RBAC to handle effectively.
• Thus, ABAC can be seen as a superset of RBAC in terms of capability. It offers everything RBAC does, with additional flexibility to incorporate a broader range of criteria into access decisions.

In summary, ABAC offers a more flexible and comprehensive approach to access control compared to RBAC, capable of handling complex, dynamic environments by leveraging a wide range of attributes, whereas RBAC offers a simpler, more straightforward approach that might be sufficient for environments with fixed access control requirements based on well-defined roles.