Detailed explanation of Auth module examples in Laravel-PHP Tutorial-php.cn

This article is based on the analysis and writing of the localization module code of Laravel 5.4 version; I hope it can help everyone learn the Auth module better.

Module composition

The Auth module is functionally divided into two parts: user authentication and permission management; in terms of file composition, the Illuminate\Auth\Passwords directory is for password reset or A small module for forgetting password processing. Illuminate\Auth is the module responsible for user authentication and permission management. Illuminate\Foundation\Auth provides a series of specific logic implementations such as login, password modification, and password reset;

Next The figure shows the relationship between the various files of the Auth module and gives a brief description;

User Authentication

HTTP itself is stateless, usually in the system During the interaction process, use the account or Token identification to determine the authenticated user;

Configuration file interpretation

return [
 'defaults' => [
 'guard' => 'web',
 ...
 ],
 'guards' => [ 
 'web' => [
  'driver' => 'session',
  'provider' => 'users',
 ],
 'api' => [ 
  'driver' => 'token', 
  'provider' => 'users',
 ],
 ],
 'providers' => [
 'users' => [
  'driver' => 'eloquent',
  'model' => App\User::class,
 ], 
 ],
], 
];

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Understand from bottom to top;

Providers is an interface that provides user data, and the driver object and target object must be marked; here, the key name users is the name of a set of providers, driven by eloquent, and modal is App\User::class;
The guards part is configured for the authentication management part; there are two authentication methods, one is called web, and the other is api; web authentication is based on Session interaction, and the user ID is obtained based on the sessionId. In the users provider Query out this user; api authentication is based on token value interaction, and also uses the users provider;
defaults item shows that web authentication is used by default;

Authentication

Session binding authentication information:

// $credentials数组存放认证条件，比如邮箱或者用户名、密码
// $remember 表示是否要记住，生成 `remember_token`
public function attempt(array $credentials = [], $remember = false) 
 
public function login(AuthenticatableContract $user, $remember = false)
 
public function loginUsingId($id, $remember = false)

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HTTP basic authentication, the authentication information is placed in the request header; subsequent requests are accessed through sessionId;

public function basic($field = 'email', $extraConditions = [])

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Only authenticates in the current session, and does not record authentication information in the session:

public function once(array $credentials = [])

public function onceUsingId($id)

public function onceBasic($field = 'email', $extraConditions = [])

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During the authentication process (including registration, forgotten password), the defined events are as follows:

##AttemptingAttempt to verify eventAuthenticatedVerification passed eventFailedVerification failed eventLockoutThe number of failures exceeds the limit, lock the request to access the event againLogiWhen logging in successfully through 'remember_token' , the event called LogoutUser exit eventRegisteredUser registration event

还有一些其他的认证方法：

检查是否存在认证用户：Auth::check()
获取当前认证用户：Auth::user()
退出系统：Auth::logout()

密码处理

配置解读

return [
 'defaults' => [
  'passwords' => 'users',
  ...
 ],
 
 'passwords' => [
  'users' => [
   'provider' => 'users',
   'table' => 'password_resets',
   'expire' => 60,
  ],
 ],
]

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从下往上，看配置；

passwords数组是重置密码的配置；users是配置方案的别名，包含三个元素：provider（提供用户的方案，是上面providers数组）、table（存放重置密码token的表）、expire（token过期时间）
default 项会设置默认的 passwords 重置方案；

重置密码的调用与实现

先看看Laravel的重置密码功能是怎么实现的：

public function reset(array $credentials, Closure $callback) {
 // 验证用户名、密码和 token 是否有效
 $user = $this->validateReset($credentials);

 if (! $user instanceof CanResetPasswordContract) {
   return $user;
 } 
 
 $password = $credentials['password'];
 // 回调函数执行修改密码，及持久化存储
 $callback($user, $password);
 // 删除重置密码时持久化存储保存的 token
 $this->tokens->delete($user);

 return static::PASSWORD_RESET;
}

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再看看Foundation\Auth模块封装的重置密码模块是怎么调用的：

// 暴露的重置密码 API
public function reset(Request $request) {
 // 验证请求参数 token、email、password、password_confirmation
 $this->validate($request, $this->rules(), $this->validationErrorMessages());
 // 调用重置密码的方法，第二个参数是回调，做一些持久化存储工作
 $response = $this->broker()->reset(
  $this->credentials($request), function ($user, $password) {
  $this->resetPassword($user, $password);
  }
 );
 // 封装 Response
 return $response == Password::PASSWORD_RESET
  ? $this->sendResetResponse($response)
  : $this->sendResetFailedResponse($request, $response);
}

// 获取重置密码时的请求参数
protected function credentials(Request $request) {
 return $request->only(
  'email', 'password', 'password_confirmation', 'token'
 );
}

// 重置密码的真实性验证后，进行的持久化工作
protected function resetPassword($user, $password) {
 // 修改后的密码、重新生成 remember_token
 $user->forceFill([
  'password' => bcrypt($password),
  'remember_token' => Str::random(60),
 ])->save();
 // session 中的用户信息也进行重新赋值          
 $this->guard()->login($user);
}

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“忘记密码 => 发邮件 => 重置密码” 的大体流程如下：

点击“忘记密码”，通过路由配置，跳到“忘记密码”页面，页面上有“要发送的邮箱”这个字段要填写；
验证“要发送的邮箱”是否是数据库中存在的，如果存在，即向该邮箱发送重置密码邮件；
重置密码邮件中有一个链接（点击后会携带 token 到修改密码页面），同时数据库会保存这个 token 的哈希加密后的值；
填写“邮箱”，“密码”，“确认密码”三个字段后，携带 token 访问重置密码API，首页判断邮箱、密码、确认密码这三个字段，然后验证 token是否有效；如果是，则重置成功；

权限管理

权限管理是依靠内存空间维护的一个数组变量abilities来维护，结构如下：

$abilities = array(
 '定义的动作名，比如以路由的 as 名(common.dashboard.list)' => function($user) {
  // 方法的参数，第一位是 $user, 当前 user, 后面的参数可以自行决定
  return true; // 返回 true 意味有权限， false 意味没有权限
 },
 ......
);

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但只用 $abilities，会使用定义的那部分代码集中在一起太烦索，所以有policy策略类的出现；

policy策略类定义一组实体及实体权限类的对应关系，比如以文章举例：

有一个 Modal实体类叫 Post，可以为这个实体类定义一个PostPolicy权限类，在这个权限类定义一些动作为方法名；

class PostPolicy {
 // update 权限，文章作者才可以修改
 public function update(User $user, Post $post) {
  return $user->id === $post->user_id;
 }
}

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然后在ServiceProvider中注册，这样系统就知道，如果你要检查的类是Post对象，加上你给的动作名，系统会找到PostPolicy类的对应方法；

protected $policies = [
 Post::class => PostPolicy::class,
];

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怎么调用呢？

对于定义在abilities数组的权限：

当前用户是否具备common.dashboard.list权限：Gate::allows('common.dashboard.list')
当前用户是否具备common.dashboard.list权限：! Gate::denies('common.dashboard.list')
当前用户是否具备common.dashboard.list权限：$request->user()->can('common.dashboard.list')
当前用户是否具备common.dashboard.list权限：! $request->user()->cannot('common.dashboard.list')
指定用户是否具备common.dashboard.list权限：Gate::forUser($user)->allows('common.dashboard.list')

对于policy策略类调用的权限：

当前用户是否可以修改文章（Gate 调用）：Gate::allows('update', $post)
当前用户是否可以修改文章（user 调用）：$user->can('update', $post)
当前用户是否可以修改文章（用帮助函数）：policy($post)->update($user, $post)
当前用户是否可以修改文章（Controller 类方法中调用）：$this->authorize('update', $post);
当前用户是否可以修改文章（Controller 类同名方法中调用）：$this->authorize($post);
指定用户是否可以修改文章（Controller 类方法中调用）：$this->authorizeForUser($user, 'update', $post);

有用的技巧

获取当前系统注册的权限，包括两部分abilities和policies数组内容，代码如下：

$gate = app(\Illuminate\Contracts\Auth\Access\Gate::class);
$reflection_gate = new ReflectionClass($gate);

$policies = $reflection_gate->getProperty('policies');
$policies->setAccessible(true);
// 获取当前注册的 policies 数组
dump($policies->getValue($gate));
                          
$abilities = $reflection_gate->getProperty('abilities');          
$abilities->setAccessible(true);
// 获取当前注册的 abilities 数组
dump($abilities->getValue($gate));

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