CakePHP JWT Authenticate plugin

Plugin containing AuthComponent's authenticate class for authenticating using JSON Web Tokens. You can read about JSON Web Token specification in detail here.

Requirements

• CakePHP 3.1+

Installation

composer require admad/cakephp-jwt-auth

Usage

In your app's config/bootstrap.php add:

// In config/bootstrap.php
Plugin::load('ADmad/JwtAuth');

or using cake's console:

./bin/cake plugin load ADmad/JwtAuth

Configuration:

Setup AuthComponent:

    // In your controller, for e.g. src/Api/AppController.php
    public function initialize()
    {
        parent::initialize();

        $this->loadComponent('Auth', [
            'storage' => 'Memory',
            'authenticate' => [
                'ADmad/JwtAuth.Jwt' => [
                    'userModel' => 'Users',
                    'fields' => [
                        'username' => 'id'
                    ],

                    'parameter' => 'token',

                    // Boolean indicating whether the "sub" claim of JWT payload
                    // should be used to query the Users model and get user info.
                    // If set to `false` JWT's payload is directly returned.
                    'queryDatasource' => true,
                ]
            ],

            'unauthorizedRedirect' => false,
            'checkAuthIn' => 'Controller.initialize',

            // If you don't have a login action in your application set
            // 'loginAction' to false to prevent getting a MissingRouteException.
            'loginAction' => false
        ]);
    }

Working

The authentication class checks for the token in two locations:

• HTTP_AUTHORIZATION environment variable:

  It first checks if token is passed using Authorization request header. The value should be of form Bearer <token>. The Authorization header name and token prefix Bearer can be customzied using options header and prefix respectively.

  Note: Some servers don't populate $_SERVER['HTTP_AUTHORIZATION'] when Authorization header is set. So it's upto you to ensure that either $_SERVER['HTTP_AUTHORIZATION'] or $_ENV['HTTP_AUTHORIZATION'] is set.

  For e.g. for apache you could use the following:

  RewriteEngine On
  RewriteCond %{HTTP:Authorization} ^(.*)
  RewriteRule .* - [e=HTTP_AUTHORIZATION:%1]
  

• The query string variable specified using parameter config:

  Next it checks if the token is present in query string. The default variable name is token and can be customzied by using the parameter config shown above.

Token Generation

You can use \Firebase\JWT\JWT::encode() of the firebase/php-jwt lib, which this plugin depends on, to generate tokens.

The payload should have the "sub" (subject) claim whos value is used to query the Users model and find record matching the "id" field.

You can set the queryDatasource option to false to directly return the token's payload as user info without querying datasource for matching user record.

Further reading

For an end to end usage example check out this blog post by Bravo Kernel.