laravel auth如何实现的

//\app\Http\Controllers\Auth\AuthController.php
/**
     * Create a new authentication controller instance.
     *
     * @param \Illuminate\Contracts\Auth\Guard     $auth
     * @param \Illuminate\Contracts\Auth\Registrar $registrar
     */
    public function __construct(Guard $auth, Registrar $registrar,Request $request)
    {
        $this->auth = $auth;
        $this->registrar = $registrar;
        $this->request = $request;
        }
        
    public function postRegister()
    {
        $data = $this->request->all();
        //调用App\Services\Registrar里的validator
        $validator = $this->registrar->validator($data);

        if ($validator->fails()) {
            $this->throwValidationException(
                $this->request, $validator
            );
        }
        $this->auth->login($this->registrar->create($data));//这里的login哪里实现的？
        
        return redirect('/user');
    }
    //\app\Providers\AppServiceProvider.php
    public function register()
    {
    //绑定实现Illuminate\Contracts\Auth\Registrar接口的类App\Services\Registrar,但没绑定auth的
        $this->app->bind(
            'Illuminate\Contracts\Auth\Registrar',
            'App\Services\Registrar'
        );
    }    

---

Login哪里实现
\Illuminate\Auth\Guard 第430行

public function login(UserContract $user, $remember = false)
    {
        $this->updateSession($user->getAuthIdentifier());

        // If the user should be permanently "remembered" by the application we will
        // queue a permanent cookie that contains the encrypted copy of the user
        // identifier. We will then decrypt this later to retrieve the users.
        if ($remember) {
            $this->createRememberTokenIfDoesntExist($user);

            $this->queueRecallerCookie($user);
        }

        // If we have an event dispatcher instance set we will fire an event so that
        // any listeners will hook into the authentication events and run actions
        // based on the login and logout events fired from the guard instances.
        $this->fireLoginEvent($user, $remember);

        $this->setUser($user);
    }

还有啥问题么= =？

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看源代码：https://github.com/laravel/framework/tree/5.1/src/Illuminate/Auth
自己扩展：http://my.oschina.net/zgldh/blog/379461#OSC_h2_1
参考第三方实现：https://cartalyst.com/manual/sentinel/2.0