RBAC-with-Casbin.md

RBAC with Casbin

Here we use the officially provided DBAL Adapter.

Installation

composer require casbin/casbin
composer require casbin/dbal-adapter

Use RBAC Model

Our model.conf has the following contents:

[request_definition]
r = sub, obj, act

[policy_definition]
p = sub, obj, act

#  the definition for the RBAC role inheritance relations
[role_definition]
g = _, _

[policy_effect]
e = some(where (p.eft == allow))

[matchers]
m = g(r.sub, p.sub) && keyMatch2(r.obj, p.obj) && regexMatch(r.act, p.act)

New a Casbin enforcer with RBAC Model

use Casbin\Enforcer;
use CasbinAdapter\DBAL\Adapter;

$adapter = Adapter::newAdapter([
    'driver' => 'pdo_mysql',
    'host' => '127.0.0.1',
    'dbname' => 'test',
    'user' => 'root',
    'password' => '',
    'port' => '3306',
]);

$enforcer = new Enforcer('path/to/model.conf', $adapter);

Add Policy

Assign roles to Alice and bob

// alice has the admin role
$enforcer->addRoleForUser('alice', 'admin'); 
// bob has the member role
$enforcer->addRoleForUser('bob', 'member');

Assign permissions to roles

member has all read operations:

$enforcer->addPermissionForUser('member', '/foo', 'GET');
$enforcer->addPermissionForUser('member', '/foo/:id', 'GET');

admin has all read and wirte operations:

// admin inherits all permissions of member
$enforcer->addRoleForUser('admin', 'member');

$enforcer->addPermissionForUser('admin', '/foo', 'POST');
$enforcer->addPermissionForUser('admin', '/foo/:id', 'PUT');
$enforcer->addPermissionForUser('admin', '/foo/:id', 'DELETE');

Now the policy rules in the database are probably like this:

g, alice, admin
g, bob, member

p, memeber, /foo, GET
p, memeber, /foo/:id, GET

g, admin, member

p, admin, /foo, POST
p, admin, /foo/:id, PUT
p, admin, /foo/:id, DELETE

Verify permissions

alice has all the permissions of /foo.

$enforcer->enforce('alice', '/foo', 'GET'); // true
$enforcer->enforce('alice', '/foo', 'GET'); // true

$enforcer->enforce('alice', '/foo', 'POST'); // true
$enforcer->enforce('alice', '/foo/1', 'PUT'); // true
$enforcer->enforce('alice', '/foo/1', 'DELETE'); // true

bob has member role, only read permission for /foo.

$enforcer->enforce('bob', '/foo', 'GET'); // true
$enforcer->enforce('bob', '/foo', 'GET'); // true

$enforcer->enforce('bob', '/foo', 'POST'); // false
$enforcer->enforce('bob', '/foo/1', 'PUT'); // false
$enforcer->enforce('bob', '/foo/1', 'DELETE'); // false