Authorization

• Introduction
• Gates
  • Writing Gates
  • Authorizing Actions
  • Gate Responses
  • Intercepting Gate Checks
  • Inline Authorization
• Creating Policies
  • Generating Policies
  • Registering Policies
• Writing Policies
  • Policy Methods
  • Policy Responses
  • Methods Without Models
  • Guest Users
  • Policy Filters
• Authorizing Actions Using Policies
  • Via the User Model
  • Via the Gate Facade
  • Via Middleware
  • Via Blade Templates
  • Supplying Additional Context
• Authorization & Inertia

Introduction

In addition to providing built-in authentication services, Laravel also provides a simple way to authorize user actions against a given resource. For example, even though a user is authenticated, they may not be authorized to update or delete certain Eloquent models or database records managed by your application. Laravel's authorization features provide an easy, organized way of managing these types of authorization checks.

Laravel provides two primary ways of authorizing actions: gates and policies. Think of gates and policies like routes and controllers. Gates provide a simple, closure-based approach to authorization while policies, like controllers, group logic around a particular model or resource. In this documentation, we'll explore gates first and then examine policies.

You do not need to choose between exclusively using gates or exclusively using policies when building an application. Most applications will most likely contain some mixture of gates and policies, and that is perfectly fine! Gates are most applicable to actions that are not related to any model or resource, such as viewing an administrator dashboard. In contrast, policies should be used when you wish to authorize an action for a particular model or resource.

拦截器 (Gates)

编写拦截器（Gates）

[! 注意]
拦截器（Gates）是学习 Laravel 授权特性基础知识的好方法，但在构建健壮的 Laravel 应用时，应该考虑结合使用策略 policies 来组织授权规则。

拦截器（Gates）是用来确定用户是否有权执行给定操作的闭包函数。通常，拦截器（Gates）通过 Gate 门面在 App\Providers\AppServiceProvider 类中的 boot 函数里定义。拦截器（Gates）始终接收一个用户实例作为第一个参数，可以选择性的接收额外参数，例如相关的 Eloquent 模型。

在下面的例子中，我们将定义一个拦截器（Gates) 来确定用户是否可以更新给定的 App\Models\Post 模型。拦截器（Gates）将通过比较用户的 id 与创建帖子的用户的 user_id 来实现该判断：

use App\Models\Post;
use App\Models\User;
use Illuminate\Support\Facades\Gate;

/**
 * 启动任何应用程序服务.
 */
public function boot(): void
{
    Gate::define('update-post', function (User $user, Post $post) {
        return $user->id === $post->user_id;
    });
}

与控制器一样，拦截器（Gates）也可以使用类回调数组来定义：

use App\Policies\PostPolicy;
use Illuminate\Support\Facades\Gate;

/**
 * 启动任何应用程序服务.
 */
public function boot(): void
{
    Gate::define('update-post', [PostPolicy::class, 'update']);
}

授权操作

要使用拦截器（Gates）授权操作，你应该使用 Gate 门面提供的 allows 或 denies 方法。注意，你不需要将当前认证的用户传递给这些方法，Laravel 会自动处理将用户传递给拦截器（gate）闭包。通常，在应用程序的控制器中，需要授权操作之前调用门面授权方法：

<?php

namespace App\Http\Controllers;

use App\Models\Post;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Gate;

class PostController extends Controller
{
    /**
     * 更新给定的帖子。
     */
    public function update(Request $request, Post $post): RedirectResponse
    {
        if (! Gate::allows('update-post', $post)) {
            abort(403);
        }

        // 更新帖子...

        return redirect('/posts');
    }
}

peryiqiao 翻译于 2个月前

0 重译

由 gyp719 审阅

If you would like to determine if a user other than the currently authenticated user is authorized to perform an action, you may use the forUser method on the Gate facade:

if (Gate::forUser($user)->allows('update-post', $post)) {
    // The user can update the post...
}

if (Gate::forUser($user)->denies('update-post', $post)) {
    // The user can't update the post...
}

You may authorize multiple actions at a time using the any or none methods:

if (Gate::any(['update-post', 'delete-post'], $post)) {
    // The user can update or delete the post...
}

if (Gate::none(['update-post', 'delete-post'], $post)) {
    // The user can't update or delete the post...
}

Authorizing or Throwing Exceptions

If you would like to attempt to authorize an action and automatically throw an Illuminate\Auth\Access\AuthorizationException if the user is not allowed to perform the given action, you may use the Gate facade's authorize method. Instances of AuthorizationException are automatically converted to a 403 HTTP response by Laravel:

Gate::authorize('update-post', $post);

// The action is authorized...

Supplying Additional Context

The gate methods for authorizing abilities (allows, denies, check, any, none, authorize, can, cannot) and the authorization Blade directives (@can, @cannot, @canany) can receive an array as their second argument. These array elements are passed as parameters to the gate closure, and can be used for additional context when making authorization decisions:

use App\Models\Category;
use App\Models\User;
use Illuminate\Support\Facades\Gate;

Gate::define('create-post', function (User $user, Category $category, bool $pinned) {
    if (! $user->canPublishToGroup($category->group)) {
        return false;
    } elseif ($pinned && ! $user->canPinPosts()) {
        return false;
    }

    return true;
});

if (Gate::check('create-post', [$category, $pinned])) {
    // The user can create the post...
}

Gate Responses

So far, we have only examined gates that return simple boolean values. However, sometimes you may wish to return a more detailed response, including an error message. To do so, you may return an Illuminate\Auth\Access\Response from your gate:

use App\Models\User;
use Illuminate\Auth\Access\Response;
use Illuminate\Support\Facades\Gate;

Gate::define('edit-settings', function (User $user) {
    return $user->isAdmin
        ? Response::allow()
        : Response::deny('You must be an administrator.');
});

Even when you return an authorization response from your gate, the Gate::allows method will still return a simple boolean value; however, you may use the Gate::inspect method to get the full authorization response returned by the gate:

$response = Gate::inspect('edit-settings');

if ($response->allowed()) {
    // The action is authorized...
} else {
    echo $response->message();
}

When using the Gate::authorize method, which throws an AuthorizationException if the action is not authorized, the error message provided by the authorization response will be propagated to the HTTP response:

Gate::authorize('edit-settings');

// The action is authorized...

Customizing The HTTP Response Status

When an action is denied via a Gate, a 403 HTTP response is returned; however, it can sometimes be useful to return an alternative HTTP status code. You may customize the HTTP status code returned for a failed authorization check using the denyWithStatus static constructor on the Illuminate\Auth\Access\Response class:

use App\Models\User;
use Illuminate\Auth\Access\Response;
use Illuminate\Support\Facades\Gate;

Gate::define('edit-settings', function (User $user) {
    return $user->isAdmin
        ? Response::allow()
        : Response::denyWithStatus(404);
});

Because hiding resources via a 404 response is such a common pattern for web applications, the denyAsNotFound method is offered for convenience:

use App\Models\User;
use Illuminate\Auth\Access\Response;
use Illuminate\Support\Facades\Gate;

Gate::define('edit-settings', function (User $user) {
    return $user->isAdmin
        ? Response::allow()
        : Response::denyAsNotFound();
});

Intercepting Gate Checks

Sometimes, you may wish to grant all abilities to a specific user. You may use the before method to define a closure that is run before all other authorization checks:

use App\Models\User;
use Illuminate\Support\Facades\Gate;

Gate::before(function (User $user, string $ability) {
    if ($user->isAdministrator()) {
        return true;
    }
});

If the before closure returns a non-null result that result will be considered the result of the authorization check.

You may use the after method to define a closure to be executed after all other authorization checks:

use App\Models\User;

Gate::after(function (User $user, string $ability, bool|null $result, mixed $arguments) {
    if ($user->isAdministrator()) {
        return true;
    }
});

Values returned by after closures will not override the result of the authorization check unless the gate or policy returned null.

Inline Authorization

Occasionally, you may wish to determine if the currently authenticated user is authorized to perform a given action without writing a dedicated gate that corresponds to the action. Laravel allows you to perform these types of "inline" authorization checks via the Gate::allowIf and Gate::denyIf methods. Inline authorization does not execute any defined "before" or "after" authorization hooks:

use App\Models\User;
use Illuminate\Support\Facades\Gate;

Gate::allowIf(fn (User $user) => $user->isAdministrator());

Gate::denyIf(fn (User $user) => $user->banned());

If the action is not authorized or if no user is currently authenticated, Laravel will automatically throw an Illuminate\Auth\Access\AuthorizationException exception. Instances of AuthorizationException are automatically converted to a 403 HTTP response by Laravel's exception handler.

Creating Policies

Generating Policies

Policies are classes that organize authorization logic around a particular model or resource. For example, if your application is a blog, you may have an App\Models\Post model and a corresponding App\Policies\PostPolicy to authorize user actions such as creating or updating posts.

You may generate a policy using the make:policy Artisan command. The generated policy will be placed in the app/Policies directory. If this directory does not exist in your application, Laravel will create it for you:

php artisan make:policy PostPolicy

The make:policy command will generate an empty policy class. If you would like to generate a class with example policy methods related to viewing, creating, updating, and deleting the resource, you may provide a --model option when executing the command:

php artisan make:policy PostPolicy --model=Post

Registering Policies

Policy Discovery

By default, Laravel automatically discover policies as long as the model and policy follow standard Laravel naming conventions. Specifically, the policies must be in a Policies directory at or above the directory that contains your models. So, for example, the models may be placed in the app/Models directory while the policies may be placed in the app/Policies directory. In this situation, Laravel will check for policies in app/Models/Policies then app/Policies. In addition, the policy name must match the model name and have a Policy suffix. So, a User model would correspond to a UserPolicy policy class.

If you would like to define your own policy discovery logic, you may register a custom policy discovery callback using the Gate::guessPolicyNamesUsing method. Typically, this method should be called from the boot method of your application's AppServiceProvider:

use Illuminate\Support\Facades\Gate;

Gate::guessPolicyNamesUsing(function (string $modelClass) {
    // Return the name of the policy class for the given model...
});

Manually Registering Policies

Using the Gate facade, you may manually register policies and their corresponding models within the boot method of your application's AppServiceProvider:

use App\Models\Order;
use App\Policies\OrderPolicy;
use Illuminate\Support\Facades\Gate;

/**
 * Bootstrap any application services.
 */
public function boot(): void
{
    Gate::policy(Order::class, OrderPolicy::class);
}

Writing Policies

Policy Methods

Once the policy class has been registered, you may add methods for each action it authorizes. For example, let's define an update method on our PostPolicy which determines if a given App\Models\User can update a given App\Models\Post instance.

The update method will receive a User and a Post instance as its arguments, and should return true or false indicating whether the user is authorized to update the given Post. So, in this example, we will verify that the user's id matches the user_id on the post:

<?php

namespace App\Policies;

use App\Models\Post;
use App\Models\User;

class PostPolicy
{
    /**
     * Determine if the given post can be updated by the user.
     */
    public function update(User $user, Post $post): bool
    {
        return $user->id === $post->user_id;
    }
}

You may continue to define additional methods on the policy as needed for the various actions it authorizes. For example, you might define view or delete methods to authorize various Post related actions, but remember you are free to give your policy methods any name you like.

If you used the --model option when generating your policy via the Artisan console, it will already contain methods for the viewAny, view, create, update, delete, restore, and forceDelete actions.

[!NOTE]
All policies are resolved via the Laravel service container, allowing you to type-hint any needed dependencies in the policy's constructor to have them automatically injected.

Policy Responses

So far, we have only examined policy methods that return simple boolean values. However, sometimes you may wish to return a more detailed response, including an error message. To do so, you may return an Illuminate\Auth\Access\Response instance from your policy method:

use App\Models\Post;
use App\Models\User;
use Illuminate\Auth\Access\Response;

/**
 * Determine if the given post can be updated by the user.
 */
public function update(User $user, Post $post): Response
{
    return $user->id === $post->user_id
        ? Response::allow()
        : Response::deny('You do not own this post.');
}

When returning an authorization response from your policy, the Gate::allows method will still return a simple boolean value; however, you may use the Gate::inspect method to get the full authorization response returned by the gate:

use Illuminate\Support\Facades\Gate;

$response = Gate::inspect('update', $post);

if ($response->allowed()) {
    // The action is authorized...
} else {
    echo $response->message();
}

When using the Gate::authorize method, which throws an AuthorizationException if the action is not authorized, the error message provided by the authorization response will be propagated to the HTTP response:

Gate::authorize('update', $post);

// The action is authorized...

Customizing the HTTP Response Status

When an action is denied via a policy method, a 403 HTTP response is returned; however, it can sometimes be useful to return an alternative HTTP status code. You may customize the HTTP status code returned for a failed authorization check using the denyWithStatus static constructor on the Illuminate\Auth\Access\Response class:

use App\Models\Post;
use App\Models\User;
use Illuminate\Auth\Access\Response;

/**
 * Determine if the given post can be updated by the user.
 */
public function update(User $user, Post $post): Response
{
    return $user->id === $post->user_id
        ? Response::allow()
        : Response::denyWithStatus(404);
}

Because hiding resources via a 404 response is such a common pattern for web applications, the denyAsNotFound method is offered for convenience:

use App\Models\Post;
use App\Models\User;
use Illuminate\Auth\Access\Response;

/**
 * Determine if the given post can be updated by the user.
 */
public function update(User $user, Post $post): Response
{
    return $user->id === $post->user_id
        ? Response::allow()
        : Response::denyAsNotFound();
}

Methods Without Models

Some policy methods only receive an instance of the currently authenticated user. This situation is most common when authorizing create actions. For example, if you are creating a blog, you may wish to determine if a user is authorized to create any posts at all. In these situations, your policy method should only expect to receive a user instance:

/**
 * Determine if the given user can create posts.
 */
public function create(User $user): bool
{
    return $user->role == 'writer';
}

Guest Users

By default, all gates and policies automatically return false if the incoming HTTP request was not initiated by an authenticated user. However, you may allow these authorization checks to pass through to your gates and policies by declaring an "optional" type-hint or supplying a null default value for the user argument definition:

<?php

namespace App\Policies;

use App\Models\Post;
use App\Models\User;

class PostPolicy
{
    /**
     * Determine if the given post can be updated by the user.
     */
    public function update(?User $user, Post $post): bool
    {
        return $user?->id === $post->user_id;
    }
}

Policy Filters

For certain users, you may wish to authorize all actions within a given policy. To accomplish this, define a before method on the policy. The before method will be executed before any other methods on the policy, giving you an opportunity to authorize the action before the intended policy method is actually called. This feature is most commonly used for authorizing application administrators to perform any action:

use App\Models\User;

/**
 * Perform pre-authorization checks.
 */
public function before(User $user, string $ability): bool|null
{
    if ($user->isAdministrator()) {
        return true;
    }

    return null;
}

If you would like to deny all authorization checks for a particular type of user then you may return false from the before method. If null is returned, the authorization check will fall through to the policy method.

[!WARNING]
The before method of a policy class will not be called if the class doesn't contain a method with a name matching the name of the ability being checked.

Authorizing Actions Using Policies

Via the User Model

The App\Models\User model that is included with your Laravel application includes two helpful methods for authorizing actions: can and cannot. The can and cannot methods receive the name of the action you wish to authorize and the relevant model. For example, let's determine if a user is authorized to update a given App\Models\Post model. Typically, this will be done within a controller method:

<?php

namespace App\Http\Controllers;

use App\Models\Post;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;

class PostController extends Controller
{
    /**
     * Update the given post.
     */
    public function update(Request $request, Post $post): RedirectResponse
    {
        if ($request->user()->cannot('update', $post)) {
            abort(403);
        }

        // Update the post...

        return redirect('/posts');
    }
}

If a policy is registered for the given model, the can method will automatically call the appropriate policy and return the boolean result. If no policy is registered for the model, the can method will attempt to call the closure-based Gate matching the given action name.

Actions That Don't Require Models

Remember, some actions may correspond to policy methods like create that do not require a model instance. In these situations, you may pass a class name to the can method. The class name will be used to determine which policy to use when authorizing the action:

<?php

namespace App\Http\Controllers;

use App\Models\Post;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;

class PostController extends Controller
{
    /**
     * Create a post.
     */
    public function store(Request $request): RedirectResponse
    {
        if ($request->user()->cannot('create', Post::class)) {
            abort(403);
        }

        // Create the post...

        return redirect('/posts');
    }
}

Via the Gate Facade

In addition to helpful methods provided to the App\Models\User model, you can always authorize actions via the Gate facade's authorize method.

Like the can method, this method accepts the name of the action you wish to authorize and the relevant model. If the action is not authorized, the authorize method will throw an Illuminate\Auth\Access\AuthorizationException exception which the Laravel exception handler will automatically convert to an HTTP response with a 403 status code:

<?php

namespace App\Http\Controllers;

use App\Models\Post;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Gate;

class PostController extends Controller
{
    /**
     * Update the given blog post.
     *
     * @throws \Illuminate\Auth\Access\AuthorizationException
     */
    public function update(Request $request, Post $post): RedirectResponse
    {
        Gate::authorize('update', $post);

        // The current user can update the blog post...

        return redirect('/posts');
    }
}

Actions That Don't Require Models

As previously discussed, some policy methods like create do not require a model instance. In these situations, you should pass a class name to the authorize method. The class name will be used to determine which policy to use when authorizing the action:

use App\Models\Post;
use Illuminate\Http\RedirectResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Gate;

/**
 * Create a new blog post.
 *
 * @throws \Illuminate\Auth\Access\AuthorizationException
 */
public function create(Request $request): RedirectResponse
{
    Gate::authorize('create', Post::class);

    // The current user can create blog posts...

    return redirect('/posts');
}

Via Middleware

Laravel includes a middleware that can authorize actions before the incoming request even reaches your routes or controllers. By default, the Illuminate\Auth\Middleware\Authorize middleware may be attached to a route using the can middleware alias, which is automatically registered by Laravel. Let's explore an example of using the can middleware to authorize that a user can update a post:

use App\Models\Post;

Route::put('/post/{post}', function (Post $post) {
    // The current user may update the post...
})->middleware('can:update,post');

In this example, we're passing the can middleware two arguments. The first is the name of the action we wish to authorize and the second is the route parameter we wish to pass to the policy method. In this case, since we are using implicit model binding, an App\Models\Post model will be passed to the policy method. If the user is not authorized to perform the given action, an HTTP response with a 403 status code will be returned by the middleware.

For convenience, you may also attach the can middleware to your route using the can method:

use App\Models\Post;

Route::put('/post/{post}', function (Post $post) {
    // The current user may update the post...
})->can('update', 'post');

Actions That Don't Require Models

Again, some policy methods like create do not require a model instance. In these situations, you may pass a class name to the middleware. The class name will be used to determine which policy to use when authorizing the action:

Route::post('/post', function () {
    // The current user may create posts...
})->middleware('can:create,App\Models\Post');

Specifying the entire class name within a string middleware definition can become cumbersome. For that reason, you may choose to attach the can middleware to your route using the can method:

use App\Models\Post;

Route::post('/post', function () {
    // The current user may create posts...
})->can('create', Post::class);

Via Blade Templates

When writing Blade templates, you may wish to display a portion of the page only if the user is authorized to perform a given action. For example, you may wish to show an update form for a blog post only if the user can actually update the post. In this situation, you may use the @can and @cannot directives:

@can('update', $post)
    <!-- The current user can update the post... -->
@elsecan('create', App\Models\Post::class)
    <!-- The current user can create new posts... -->
@else
    <!-- ... -->
@endcan

@cannot('update', $post)
    <!-- The current user cannot update the post... -->
@elsecannot('create', App\Models\Post::class)
    <!-- The current user cannot create new posts... -->
@endcannot

These directives are convenient shortcuts for writing @if and @unless statements. The @can and @cannot statements above are equivalent to the following statements:

@if (Auth::user()->can('update', $post))
    <!-- The current user can update the post... -->
@endif

@unless (Auth::user()->can('update', $post))
    <!-- The current user cannot update the post... -->
@endunless

You may also determine if a user is authorized to perform any action from a given array of actions. To accomplish this, use the @canany directive:

@canany(['update', 'view', 'delete'], $post)
    <!-- The current user can update, view, or delete the post... -->
@elsecanany(['create'], \App\Models\Post::class)
    <!-- The current user can create a post... -->
@endcanany

Actions That Don't Require Models

Like most of the other authorization methods, you may pass a class name to the @can and @cannot directives if the action does not require a model instance:

@can('create', App\Models\Post::class)
    <!-- The current user can create posts... -->
@endcan

@cannot('create', App\Models\Post::class)
    <!-- The current user can't create posts... -->
@endcannot

Supplying Additional Context

When authorizing actions using policies, you may pass an array as the second argument to the various authorization functions and helpers. The first element in the array will be used to determine which policy should be invoked, while the rest of the array elements are passed as parameters to the policy method and can be used for additional context when making authorization decisions. For example, consider the following PostPolicy method definition which contains an additional $category parameter:

/**
 * Determine if the given post can be updated by the user.
 */
public function update(User $user, Post $post, int $category): bool
{
    return $user->id === $post->user_id &&
           $user->canUpdateCategory($category);
}

When attempting to determine if the authenticated user can update a given post, we can invoke this policy method like so:

/**
 * Update the given blog post.
 *
 * @throws \Illuminate\Auth\Access\AuthorizationException
 */
public function update(Request $request, Post $post): RedirectResponse
{
    Gate::authorize('update', [$post, $request->category]);

    // The current user can update the blog post...

    return redirect('/posts');
}

Authorization & Inertia

Although authorization must always be handled on the server, it can often be convenient to provide your frontend application with authorization data in order to properly render your application's UI. Laravel does not define a required convention for exposing authorization information to an Inertia powered frontend.

However, if you are using one of Laravel's Inertia-based starter kits, your application already contains a HandleInertiaRequests middleware. Within this middleware's share method, you may return shared data that will be provided to all Inertia pages in your application. This shared data can serve as a convenient location to define authorization information for the user:

<?php

namespace App\Http\Middleware;

use App\Models\Post;
use Illuminate\Http\Request;
use Inertia\Middleware;

class HandleInertiaRequests extends Middleware
{
    // ...

    /**
     * Define the props that are shared by default.
     *
     * @return array<string, mixed>
     */
    public function share(Request $request)
    {
        return [
            ...parent::share($request),
            'auth' => [
                'user' => $request->user(),
                'permissions' => [
                    'post' => [
                        'create' => $request->user()->can('create', Post::class),
                    ],
                ],
            ],
        ];
    }
}