Yii Role-Based Access Control

This package provides RBAC (Role-Based Access Control) library. It is used in Yii Framework but is usable separately as well.

Features

Flexible RBAC hierarchy with roles, permissions, and rules.
Role inheritance.
Data could be passed to rules when checking access.
Multiple storage adapters.
Separate storages could be used for user-role assignments and role hierarchy.
API to manage RBAC hierarchy.

Requirements

PHP 8.1 or higher.

Installation

The package could be installed with Composer:

composer require yiisoft/rbac

One of the following storages could be installed as well:

PHP storage - PHP file storage;
DB storage - database storage based on Yii DB;
Cycle DB storage - database storage based on Cycle DBAL.

Also, there is a rule factory implementation - Rules Container (based on Yii Factory).

All these can be replaced with custom implementations.

General usage

Setting up manager

First step when using RBAC is to configure an instance of Manager:

use Yiisoft\Rbac\AssignmentsStorageInterface;
use Yiisoft\Rbac\ItemsStorageInterface;
use Yiisoft\Rbac\RuleFactoryInterface;

/**
* @var ItemsStorageInterface $itemsStorage
* @var AssignmentsStorageInterface $assignmentsStorage
* @var RuleFactoryInterface $ruleFactory
*/
$manager = new Manager($itemsStorage, $assignmentsStorage, $ruleFactory);

It requires the following dependencies:

Items storage (hierarchy itself).
Assignments storage where user IDs are mapped to roles.
Rule factory. Creates a rule instance by a given name.

While storages are required, rule factory is optional and, when omitted, SimpleRuleFactory will be used. For more advanced usage, such as resolving rules by aliases and passing arguments in rules constructor, install Rules Container additionally or write your own implementation.

A few tips for choosing storage backend:

Roles and permissions could usually be considered "semi-static," as they only change when you update your application code, so it may make sense to use PHP storage for it.
Assignments, on the other hand, could be considered "dynamic." They change more often: when creating a new user, or when updating a user role from within your application. So it may make sense to use database storage for assignments.

Managing RBAC hierarchy

Before being able to check for permissions, an RBAC hierarchy must be defined. Usually it is done via either console commands or migrations. Hierarchy consists of permissions, roles, and rules:

Permissions are granules of access such as "create a post" or "read a post."
A role is what is assigned to the user. The Role is granted one or more permissions. Typical roles are "manager" or "admin."
Rule is a PHP class that has given some data answers a single question "given the data has the user the permission asked for."

To create a permission, use the following code:

use Yiisoft\Rbac\ManagerInterface;
use Yiisoft\Rbac\Permission;

/** @var ManagerInterface $manager */
$manager->addPermission(new Permission('createPost'));
$manager->addPermission(new Permission('readPost'));
$manager->addPermission(new Permission('deletePost'));

To add some roles:

use Yiisoft\Rbac\ManagerInterface;
use Yiisoft\Rbac\Role;

/** @var ManagerInterface $manager */
$manager->addRole(new Role('author'));
$manager->addRole(new Role('reader'));

Next, we need to attach permissions to roles:

use Yiisoft\Rbac\ManagerInterface;

/** @var ManagerInterface $manager */
$manager->addChild('reader', 'readPost');
$manager->addChild('author', 'createPost');
$manager->addChild('author', 'deletePost');
$manager->addChild('author', 'reader');

Hierarchy for the example above:

flowchart LR
  createPost:::permission ---> author:::role
  readPost:::permission --> reader:::role --> author:::role
  deletePost:::permission ---> author:::role
  classDef permission fill:#fc0,stroke:#000,color:#000
  classDef role fill:#9c0,stroke:#000,color:#000

Sometimes, basic permissions are not enough. In this case, rules are helpful. Rules are PHP classes that could be added to permissions and roles:

use Yiisoft\Rbac\Item;
use Yiisoft\Rbac\RuleContext;
use Yiisoft\Rbac\RuleInterface;

class ActionRule implements RuleInterface
{
    public function execute(?string $userId, Item $item, RuleContext $context): bool;
    {
        return $context->getParameterValue('action') === 'home';
    }
}

With rule added, the role or permission is considered only when rule's execute() method returns true.

The parameters are:

$userId is user id to check permission against;
$item is RBAC hierarchy item that rule is attached to;
$context is a rule context providing access to parameters.

To use rules with Manager, specify their names with added permissions or roles:

use Yiisoft\Rbac\ManagerInterface;
use Yiisoft\Rbac\Permission;

/** @var ManagerInterface $manager */
$manager->addPermission( 
    (new Permission('viewList'))->withRuleName(ActionRule::class),
);

// or

$manager->addRole(
    (new Role('NewYearMaintainer'))->withRuleName(NewYearOnlyRule::class)
);

The rule names action_rule and new_year_only_rule are resolved to ActionRule and NewYearOnlyRule class instances accordingly via rule factory.

If you need to aggregate multiple rules at once, use composite rule:

use Yiisoft\Rbac\CompositeRule;

// Fresh and owned
$compositeRule = new CompositeRule(CompositeRule::AND, [FreshRule::class, OwnedRule::class]);

// Fresh or owned
$compositeRule = new CompositeRule(CompositeRule::OR, [FreshRule::class, OwnedRule::class]);

Assigning roles to users

To assign a certain role to a user with a given ID, use the following code:

use Yiisoft\Rbac\ManagerInterface;

/** @var ManagerInterface $manager */
$userId = 100;
$manager->assign('author', $userId);

It could be done in an admin panel, via console command, or it could be built into the application business logic itself.

Check for permission

To check for permission, obtain an instance of Yiisoft\Access\AccessCheckerInterface and use it:

use Psr\Http\Message\ResponseInterface; 
use Yiisoft\Access\AccessCheckerInterface;

public function actionCreate(AccessCheckerInterface $accessChecker): ResponseInterface
{
    $userId = getUserId();

    if ($accessChecker->userHasPermission($userId, 'createPost')) {
        // author has permission to create post
    }
}

Sometimes you need to add guest-only permission, which is not assigned to any user ID. In this case, you can specify a role which is assigned to guest user:

use Yiisoft\Access\AccessCheckerInterface;
use Yiisoft\Rbac\Permission;
use Yiisoft\Rbac\Role;

/** 
 * @var ManagerInterface $manager
 * @var AccessCheckerInterface $accessChecker 
 */
$manager->setGuestRoleName('guest');
$manager->addPermission(new Permission('signup'));
$manager->addRole(new Role('guest'));
$manager->addChild('guest', 'signup');

$guestId = null;
if ($accessChecker->userHasPermission($guestId, 'signup')) {
    // Guest has "signup" permission.
}

If there is a rule involved, you may pass extra parameters:

use Yiisoft\Rbac\ManagerInterface;

/** @var ManagerInterface $manager */
$anotherUserId = 103;
if (!$manager->userHasPermission($anotherUserId, 'viewList', ['action' => 'home'])) {
    echo 'reader hasn\'t "index" permission';
}