Casbin RBAC vs. RBAC96

Casbin RBAC and RBAC96

This document compares Casbin RBAC with RBAC96.

Casbin RBAC implements nearly all RBAC96 features while adding enhancements.

RBAC Version	Support Level	Description
RBAC0	Fully Supported	RBAC0 provides basic RBAC96 functionality, defining relationships between Users, Roles, and Permissions.
RBAC1	Fully Supported	RBAC1 extends RBAC0 with role hierarchies. When `alice` has `role1` and `role1` has `role2`, then `alice` inherits `role2` and its permissions.
RBAC2	Mutually Exclusive Handling Supported (like this)	RBAC2 adds constraints to RBAC0, enabling mutually exclusive policy handling. Quantitative limits are unsupported.
RBAC3	Mutually Exclusive Handling Supported (like this)	RBAC3 combines RBAC1 and RBAC2, supporting both role hierarchies and constraints. Quantitative limits are unsupported.

Casbin handles User-Role distinction less strictly than RBAC96.

Casbin treats both Users and Roles as strings. Consider this policy:
```
p, admin, book, read
p, alice, book, read
g, amber, admin
```
Calling GetAllSubjects() on a Casbin Enforcer:
```
e.GetAllSubjects()
```
returns:
```
[admin alice]
```
Casbin includes both Users and Roles as subjects.

However, calling GetAllRoles():
```
e.GetAllRoles()
```
returns:
```
[admin]
```
Casbin distinguishes Users from Roles, but less strictly than RBAC96. Add prefixes like user::alice and role::admin to clarify relationships.
Casbin RBAC offers more flexible permissions than RBAC96.

RBAC96 defines seven permissions: read, write, append, execute, credit, debit, and inquiry.

Casbin treats permissions as strings, letting you define permissions matching your requirements.
Casbin RBAC supports domains.

Casbin enables domain-based authorization, providing greater Access Control Model flexibility.