Laravel中的Auth

摘要：中的中有一个组件叫，组件提供了整个框架的认证功能，这里想简单追踪一下它的实现逻辑。

laravel中有一个组件叫auth，auth组件提供了整个框架的认证功能，这里想简单追踪一下它的实现逻辑。

# IlluminateAuthConsoleAuthMakeCommand.php

public function handle()
{
    // 创建存放auth前端界面的目录和文件
    // 模版存放在AuthConsole的stubs下
    $this->createDirectories();
    $this->exportViews();

    if (! $this->option("views")) {
        // 生成HomeController控制器文件
        file_put_contents(
            app_path("Http/Controllers/HomeController.php"),
            $this->compileControllerStub()
        );
        // 生成auth相关路由
    file_put_contents(
        base_path("routes/web.php"),
        file_get_contents(__DIR__."/stubs/make/routes.stub"),
        FILE_APPEND
        );
    }
}

生成文件resources/views/auth、 resources/layouts路由文件 web.php 、和 Http/Controllers/Auth 下的控制器

        function csrf_token()
    {
        $session = app("session");

        if (isset($session)) {
            return $session->token();
        }

        throw new RuntimeException("Application session store not set.");
    }

    public function login(Request $request)
    {
                // 检查请求体
        $this->validateLogin($request);
                // 判断是否请求失败太多次
        if ($this->hasTooManyLoginAttempts($request)) {
            $this->fireLockoutEvent($request);

            return $this->sendLockoutResponse($request);
        }
                // 判断是否验证通过
        if ($this->attemptLogin($request)) {
            return $this->sendLoginResponse($request);
        }
                // 记录请求失败次数
        $this->incrementLoginAttempts($request);

        return $this->sendFailedLoginResponse($request);
    }

通过 Auth::guard() 引导到 IlluminateAuthAuthManager
先看  服务提供者  AuthServiceProvider
AuthServiceProvider注册四个服务

protected function registerAuthenticator()
    {
        $this->app->singleton("auth", function ($app) {
            $app["auth.loaded"] = true;
                        // 生成一个AuthManager实例
            return new AuthManager($app);
        });

        $this->app->singleton("auth.driver", function ($app) {
            return $app["auth"]->guard();
        });
    }

protected function registerUserResolver()
    {
        $this->app->bind(
            AuthenticatableContract::class, function ($app) {
                return call_user_func($app["auth"]->userResolver());
            }
        );
    }

protected function registerAccessGate()
    {
        $this->app->singleton(GateContract::class, function ($app) {
            return new Gate($app, function () use ($app) {
                return call_user_func($app["auth"]->userResolver());
            });
        });
    }

protected function registerRequestRebindHandler()
    {
        $this->app->rebinding("request", function ($app, $request) {
            $request->setUserResolver(function ($guard = null) use ($app) {
                return call_user_func($app["auth"]->userResolver(), $guard);
            });
        });
    }

生成一个AuthManager实例
AuthManager中的trait CreatesUserProviders
这个trait是用来绑定一个用户认证的Eloqument服务提供者

public function __construct($app)
    {
                // 绑定application实例
        $this->app = $app;
                // 绑定一个闭包，用于解析用户。
                // 通过$guard来确定用户解析用户的方法
        $this->userResolver = function ($guard = null) {
            return $this->guard($guard)->user();
        };
    }

protected function resolve($name)
    {
        $config = $this->getConfig($name);

                // 根据配置调用不同的解析用户的驱动方法
        $driverMethod = "create".ucfirst($config["driver"])."Driver";

        if (method_exists($this, $driverMethod)) {
            return $this->{$driverMethod}($name, $config);
        }
    }

分别定位的两个方法

        public function createSessionDriver($name, $config)
    {
                //     根据配置文件创建一个相应的provider
        $provider = $this->createUserProvider($config["provider"] ?? null);
                
                $guard = new SessionGuard($name, $provider, $this->app["session.store"]);

        return $guard;
    }
    
    public function createTokenDriver($name, $config)
    {
        $guard = new TokenGuard(
            $this->createUserProvider($config["provider"] ?? null),
            $this->app["request"],
            $config["input_key"] ?? "api_token",
            $config["storage_key"] ?? "api_token"
        );
        return $guard;
    }

于是得到 $this->guard($guard) 的user()方法
先看如何实例一个TokenGuard类

public function __construct(UserProvider $provider, Request $request, $inputKey = "api_token", $storageKey = "api_token")
    {
        $this->request = $request;
        $this->provider = $provider;
        $this->inputKey = $inputKey;
        $this->storageKey = $storageKey;
    }

# IlluminateAuthTokenGuard

    public function user()
    {
        if (! is_null($this->user)) {
            return $this->user;
        }

        $user = null;
                // 从request中获取token
        $token = $this->getTokenForRequest();

        if (! empty($token)) {
                        // 通过用户provider中的retrieveByCredentials方法来判断用户是否认证成功
            $user = $this->provider->retrieveByCredentials(
                [$this->storageKey => $token]
            );
        }

        return $this->user = $user;
    }

上面都是通用的加载引导调用功能，下面的用户服务提供者则是可以修改自定义的认证的具体功能

# IlluminateAuthDatabaseUserProvider

    public function retrieveByCredentials(array $credentials)
    {
        if (empty($credentials) ||
           (count($credentials) === 1 &&
            array_key_exists("password", $credentials))) {
            return;
        }
        $query = $this->conn->table($this->table);

        foreach ($credentials as $key => $value) {
            if (Str::contains($key, "password")) {
                continue;
            }

            if (is_array($value) || $value instanceof Arrayable) {
                $query->whereIn($key, $value);
            } else {
                $query->where($key, $value);
            }
        }
        
        $user = $query->first();
        
        // 返回auth用户数据包
        return $this->getGenericUser($user);
    }