ZF MVC Auth

Introduction

zf-mvc-auth is a ZF2 module that adds services, events, and configuration that extends the base ZF2 MVC lifecycle to handle authentication and authorization.

For authentication, 3 primary methods are supported out of the box: HTTP Basic authentication, HTTP Digest authentication, and OAuth2 (this requires Brent Shaffer's OAuth2 Server).

For authorization, this particular module delivers a pre-dispatch time listener that will identify if the given route match, along with the HTTP method, is authorized to be dispatched.

Requirements

Please see the composer.json file.

Installation

Run the following composer command:

$ composer require "zfcampus/zf-mvc-auth"

Alternately, manually add the following to your composer.json, in the require section:

"require": {
    "zfcampus/zf-mvc-auth": "^1.4"
}

And then run composer update to ensure the module is installed.

Finally, add the module name to your project's config/application.config.php under the modules key:

return [
    /* ... */
    'modules' => [
        /* ... */
        'ZF\MvcAuth',
    ],
    /* ... */
];

Configuration

User Configuration

The top-level configuration key for user configuration of this module is zf-mvc-auth. Under this key, there are two sub-keys, one for authentication and the other for authorization.

Key: authentication

The authentication key is used for any configuration that is related to the process of authentication, or the process of validating an identity.

Sub-key: http

The http sub-key is utilized for configuring an HTTP-based authentication scheme. These schemes utilize ZF2's Zend\Authentication\Adapter\Http adapter, which implements both HTTP Basic and HTTP Digest authentication. To accomplish this, the HTTP adapter uses a file based "resolver" in order to resolve the file containing credentials. These implementation nuances can be explored in the Authentication portion of the ZF2 manual.

The http sub-key has several fields:

• accept_schemes: required; an array of configured schemes; one or both of basic and digest.
• realm: required; this is typically a string that identifies the HTTP realm; e.g., "My Site".
• digest_domains: required for HTTP Digest; this is the relative URI for the protected area, typically /.
• nonce_timeout: required for HTTP Digest; the number of seconds in which to expire the digest nonce, typically 3600.

Beyond those configuration options, one or both of the following resolver configurations is required:

• htpasswd: the path to a file created in the htpasswd file format
• htdigest: the path to a file created in the htdigest file format

An example might look like the following:

'http' => [
    'accept_schemes' => ['basic', 'digest'],
    'realm' => 'My Web Site',
    'digest_domains' => '/',
    'nonce_timeout' => 3600,
    'htpasswd' => APPLICATION_PATH . '/data/htpasswd', // htpasswd tool generated
    'htdigest' => APPLICATION_PATH . '/data/htdigest', // @see http://www.askapache.com/online-tools/htpasswd-generator/
],

Sub-key: map

• Since 1.1.0.

The map subkey is used to map an API module (optionally, with a version namespace) to a given authentication type (typically, one of basic, digest, or oauth2). This can be used to enfore different authentication methods for different APIs, or even versions of the same API.

return [
    'zf-mvc-auth' => [
        'authentication' => [
            'map' => [
                'Status\V1' => 'basic',  // v1 only!
                'Status\V2' => 'oauth2', // v2 only!
                'Ping'      => 'digest', // all versions!
            ],
        ],
    ],
];

In the absence of a map subkey, if any authentication adapter configuration is defined, that configuration will be used for any API.

Note for users migrating from 1.0: In the 1.0 series, authentication was per-application, not per API. The migration to 1.1 should be seamless; if you do not edit your authentication settings, or provide authentication information to any APIs, your API will continue to act as it did. The first time you perform one of these actions, the Admin API will create a map, mapping each version of each service to the configured authentication scheme, and thus ensuring that your API continues to work as previously configured, while giving you the flexibility to define authentication per-API and per-version in the future.

Sub-key: types

• Since 1.1.0.

Starting in 1.1.0, the concept of authentication adapters was provided. Adapters "provide" one or more authentication types; these are then used internally to determine which adapter to use, as well as by the Admin API to allow mapping APIs to specific authentication types.

In some instances you may be using listeners or other facilities for authenticating an API. In order to allow mapping these (which is primarily a documentation feature in such instances), the types subkey exists. This key is an array of string authentication types:

return [
    'zf-mvc-auth' => [
        'authentication' => [
            'types' => [
                'token',
                'key',
            ],
        ],
    ],
];

This key and its contents must be created manually.

Sub-key: adapters

• Since 1.1.0.

Starting in 1.1.0, with the introduction of adapters, you can also configure named HTTP and OAuth2 adapters. The name provided will be used as the authentication type for purposes of mapping APIs to an authentication adapter.

The format for the adapters key is a key/value pair, with the key acting as the type, and the value as configuration for providing a ZF\MvcAuth\Authentication\HttpAdapter or ZF\MvcAuth\Authentication\OAuth2Adapter instance, as follows:

return [
    'zf-mvc-auth' => [
        'authentication' => [
            'adapters' => [
                'api' => [
                    // This defines an HTTP adapter that can satisfy both
                    // basic and digest.
                    'adapter' => 'ZF\MvcAuth\Authentication\HttpAdapter',
                    'options' => [
                        'accept_schemes' => ['basic', 'digest'],
                        'realm' => 'api',
                        'digest_domains' => 'https://example.com',
                        'nonce_timeout' => 3600,
                        'htpasswd' => 'data/htpasswd',
                        'htdigest' => 'data/htdigest',
                    ],
                ],
                'user' => [
                    // This defines an OAuth2 adapter backed by PDO.
                    'adapter' => 'ZF\MvcAuth\Authentication\OAuth2Adapter',
                    'storage' => [
                        'adapter' => 'pdo',
                        'dsn' => 'mysql:host=localhost;dbname=oauth2',
                        'username' => 'username',
                        'password' => 'password',
                        'options' => [
                            1002 => 'SET NAMES utf8', // PDO::MYSQL_ATTR_INIT_COMMAND
                        ],
                    ],
                ],
                'client' => [
                    // This defines an OAuth2 adapter backed by Mongo.
                    'adapter' => 'ZF\MvcAuth\Authentication\OAuth2Adapter',
                    'storage' => [
                        'adapter' => 'mongo',
                        'locator_name' => 'SomeServiceName', // If provided, pulls the given service
                        'dsn' => 'mongodb://localhost',
                        'database' => 'oauth2',
                        'options' => [
                            'username' => 'username',
                            'password' => 'password',
                            'connectTimeoutMS' => 500,
                        ],
                    ],
                ],
            ],
        ],
    ],
];

Key: authorization

Sub-Key: deny_by_default

deny_by_default toggles the default behavior for the Zend\Permissions\Acl implementation. The default value is false, which means that if no authenticated user is present, and no permissions rule applies for the current resource, then access is allowed. Change this setting to true to require authenticated identities by default.

Example:

'deny_by_default' => false,

deny_by_default with zf-oauth2

When using deny_by_default => true with > zf-oauth2, you will need to explicitly allow POST on the OAuth2 controller in order for Authentication requests to be made.

As an example:

'authorization' => [
    'deny_by_default' => true,
    'ZF\\OAuth2\\Controller\\Auth' => [
        'actions' => [
            'token' => [
                'GET'    => false,
                'POST'   => true,   // <-----
                'PATCH'  => false,
                'PUT'    => false,
                'DELETE' => false,
            ],
        ],
    ],
],

Sub-Key: Controller Service Name

Under the authorization key is an array of controller service name keyed authorization configuration settings. The structure of these arrays depends on the type of the controller service that you're attempting to grant or restrict access to.

For the typical ZF2 based action controller, this array is keyed with actions. Under this key, each action name for the given controller service is associated with a permission array.

For zf-rest-based controllers, a top level key of either collection or entity is used. Under each of these keys will be an associated permission array.

A permission array consists of a keyed array of either default or an HTTP method. The values for each of these will be a boolean value where true means an authenticated user is required and where false means an authenticated user is not required. If an action or HTTP method is not idendified, the default value will be assumed. If there is no default, the behavior of the deny_by_default key (discussed above) will be assumed.

Below is an example:

'authorization' => [
    'Controller\Service\Name' => [
        'actions' => [
            'action' => [
                'default' => boolean,
                'GET' => boolean,
                'POST' => boolean,
                // etc.
            ],
        ],
        'collection' => [
            'default' => boolean,
            'GET' => boolean,
            'POST' => boolean,
            // etc.
        ],
        'entity' => [
            'default' => boolean,
            'GET' => boolean,
            'POST' => boolean,
            // etc.
        ],
    ],
],

System Configuration

The following configuration is provided in config/module.config.php to enable the module to function:

'service_manager' => [
    'aliases' => [
        'authentication' => 'ZF\MvcAuth\Authentication',
        'authorization' => 'ZF\MvcAuth\Authorization\AuthorizationInterface',
        'ZF\MvcAuth\Authorization\AuthorizationInterface' => 'ZF\MvcAuth\Authorization\AclAuthorization',
    ],
    'factories' => [
        'ZF\MvcAuth\Authentication' => 'ZF\MvcAuth\Factory\AuthenticationServiceFactory',
        'ZF\MvcAuth\ApacheResolver' => 'ZF\MvcAuth\Factory\ApacheResolverFactory',
        'ZF\MvcAuth\FileResolver' => 'ZF\MvcAuth\Factory\FileResolverFactory',
        'ZF\MvcAuth\Authentication\DefaultAuthenticationListener' => 'ZF\MvcAuth\Factory\DefaultAuthenticationListenerFactory',
        'ZF\MvcAuth\Authentication\AuthHttpAdapter' => 'ZF\MvcAuth\Factory\DefaultAuthHttpAdapterFactory',
        'ZF\MvcAuth\Authorization\AclAuthorization' => 'ZF\MvcAuth\Factory\AclAuthorizationFactory',
        'ZF\MvcAuth\Authorization\DefaultAuthorizationListener' => 'ZF\MvcAuth\Factory\DefaultAuthorizationListenerFactory',
        'ZF\MvcAuth\Authorization\DefaultResourceResolverListener' => 'ZF\MvcAuth\Factory\DefaultResourceResolverListenerFactory',
    ],
    'invokables' => [
        'ZF\MvcAuth\Authentication\DefaultAuthenticationPostListener' => 'ZF\MvcAuth\Authentication\DefaultAuthenticationPostListener',
        'ZF\MvcAuth\Authorization\DefaultAuthorizationPostListener' => 'ZF\MvcAuth\Authorization\DefaultAuthorizationPostListener',
    ],
],

These services will be described in the events and services section.

ZF2 Events

Events

ZF\MvcAuth\MvcAuthEvent::EVENT_AUTHENTICATION (a.k.a "authentication")

This event is triggered in relation to MvcEvent::EVENT_ROUTE at 500 priority. It is registered via the ZF\MvcAuth\MvcRouteListener event listener aggregate.

ZF\MvcAuth\MvcAuthEvent::EVENT_AUTHENTICATION_POST (a.k.a "authentication.post")

This event is triggered in relation to MvcEvent::EVENT_ROUTE at 499 priority. It is registered via the ZF\MvcAuth\MvcRouteListener event listener aggregate.

ZF\MvcAuth\MvcAuthEvent::EVENT_AUTHORIZATION (a.k.a "authorization")

This event is triggered in relation to MvcEvent::EVENT_ROUTE at -600 priority. It is registered via the ZF\MvcAuth\MvcRouteListener event listener aggregate.

ZF\MvcAuth\MvcAuthEvent::EVENT_AUTHORIZATION_POST (a.k.a "authorization.post")

This event is triggered in relation to MvcEvent::EVENT_ROUTE at -601 priority. It is registered via the ZF\MvcAuth\MvcRouteListener event listener aggregate.

ZF\MvcAuth\MvcAuthEvent object

The MvcAuthEvent object provides contextual information when any authentication or authorization event is triggered. It persists the following:

• identity: setIdentity() and getIdentity()
• authentication service: setAuthentication() and getAuthentication()
• authorization service: setAuthorization() and getAuthorization()
• authorization result: setIsAuthorized and isAuthorized()
• original MVC event: getMvcEvent()

Listeners

ZF\MvcAuth\Authentication\DefaultAuthenticationListener

This listener is attached to the MvcAuth::EVENT_AUTHENTICATION event. It is primarily responsible for preforming any authentication and ensuring that an authenticated identity is persisted in both the MvcAuthEvent and MvcEvent objects (the latter under the event parameter ZF\MvcAuth\Identity).

ZF\MvcAuth\Authentication\DefaultAuthenticationPostListener

This listener is attached to the MvcAuth::EVENT_AUTHENTICATION_POST event. It is primarily responsible for determining if an unsuccessful authentication was preformed, and in that case it will attempt to set a 401 Unauthorized status on the MvcEvent's response object.

ZF\MvcAuth\Authorization\DefaultAuthorizationListener

This listener is attached to the MvcAuth::EVENT_AUTHORIZATION event. It is primarily responsible for executing the isAuthorized() method on the configured authorization service.

ZF\MvcAuth\Authorization\DefaultAuthorizationPostListener

This listener is attached to the MvcAuth::EVENT_AUTHORIZATION_POST event. It is primarily responsible for determining if the current request is authorized. In the case where the current request is not authorized, it will attempt to set a 403 Forbidden status on the MvcEvent's response object.

ZF\MvcAuth\Authorization\DefaultResourceResolverListener

This listener is attached to the MvcAuth::EVENT_AUTHENTICATION_POST with a priority of -1. It is primarily responsible for creating and persisting a special name in the current event for zf-rest-based controllers when used in conjunction with zf-rest module.

ZF2 Services

Controller Plugins

This module exposes the controller plugin getIdentity(), mapping to ZF\MvcAuth\Identity\IdentityPlugin. This plugin will return the identity discovered during authentication as injected into the Zend\Mvc\MvcEvent's ZF\MvcAuth\Identity parameter. If no identity is present in the MvcEvent, or the identity present is not an instance of ZF\MvcAuth\Identity\IdentityInterface, an instance of ZF\MvcAuth\Identity\GuestIdentity will be returned.

Event Listener Services

The following services are provided and serve as event listeners:

• ZF\MvcAuth\Authentication\DefaultAuthenticationListener
• ZF\MvcAuth\Authentication\DefaultAuthenticationPostListener
• ZF\MvcAuth\Authorization\DefaultAuthorizationListener
• ZF\MvcAuth\Authorization\DefaultAuthorizationPostListener
• ZF\MvcAuth\Authorization\DefaultResourceResolverListener

ZF\MvcAuth\Authentication (a.k.a "authentication")

This is an instance of Zend\Authentication\AuthenticationService.

ZF\MvcAuth\Authentication\AuthHttpAdapter

This is an instance of Zend\Authentication\Adapter\Http.

ZF\MvcAuth\Authorization\AclAuthorization (a.k.a "authorization", "ZF\MvcAuth\Authorization\AuthorizationInterface")

This is an instance of ZF\MvcAuth\Authorization\AclAuthorization, which in turn is an extension of Zend\Permissions\Acl\Acl.

ZF\MvcAuth\ApacheResolver

This is an instance of Zend\Authentication\Adapter\Http\ApacheResolver. You can override the ApacheResolver with your own resolver by providing a custom factory.

ZF\MvcAuth\FileResolver

This is an instance of Zend\Authentication\Adapter\Http\FileResolver. You can override the FileResolver with your own resolver by providing a custom factory.

Authentication Adapters

• Since 1.1.0

Authentication adapters provide the most direct means for adding custom authentication facilities to your APIs. Adapters implement ZF\MvcAuth\Authentication\AdapterInterface:

namespace ZF\MvcAuth\Authentication;

use Zend\Http\Request;
use Zend\Http\Response;
use ZF\MvcAuth\Identity\IdentityInterface;
use ZF\MvcAuth\MvcAuthEvent;

interface AdapterInterface
{
    /**
     * @return array Array of types this adapter can handle.
     */
    public function provides();

    /**
     * Attempt to match a requested authentication type
     * against what the adapter provides.
     *
     * @param string $type
     * @return bool
     */
    public function matches($type);

    /**
     * Attempt to retrieve the authentication type based on the request.
     *
     * Allows an adapter to have custom logic for detecting if a request
     * might be providing credentials it's interested in.
     *
     * @param Request $request
     * @return false|string
     */
    public function getTypeFromRequest(Request $request);

    /**
     * Perform pre-flight authentication operations.
     *
     * Use case would be for providing authentication challenge headers.
     *
     * @param Request $request
     * @param Response $response
     * @return void|Response
     */
    public function preAuth(Request $request, Response $response);

    /**
     * Attempt to authenticate the current request.
     *
     * @param Request $request
     * @param Response $response
     * @param MvcAuthEvent $mvcAuthEvent
     * @return false|IdentityInterface False on failure, IdentityInterface
     *     otherwise
     */
    public function authenticate(Request $request, Response $response, MvcAuthEvent $mvcAuthEvent);
}

The provides() method should return an array of strings, each an authentication "type" that this adapter provides; as an example, the provided ZF\MvcAuth\Authentication\HttpAdapter can provide basic and/or digest.

The matches($type) should test the given $type against what the adapter provides to determine if it can handle an authentication request. Typically, this can be done with return in_array($type, $this->provides(), true);

The getTypeFromRequest() method can be used to match an incoming request to the authentication type it resolves, if any. Examples might be deconstructing the Authorization header, or a custom header such as X-Api-Token.

The preAuth() method can be used to provide client challenges; typically, this will only ever be used by the included HttpAdapter.

Finally, the authenticate() method is used to attempt to authenticate an incoming request. I should return either a boolean false, indicating authentictaion failed, or an instance of ZF\MvcAuth\Identity\IdentityInterface; if the latter is returned, that identity will be used for the duration of the request.

Adapters are attached to the DefaultAuthenticationListener. To attach your custom adapter, you will need to do one of the following:

• Define named HTTP and/or OAuth2 adapters via configuration.
• During an event listener, pull your adapter and the DefaultAuthenticationListener services, and attach your adapter to the latter.
• Create a DelegatorFactory for the DefaultAuthenticationListener that attaches your custom adapter before returning the listener.

Defining named HTTP and/or OAuth2 adapters

Since HTTP and OAuth2 support is built-in, zf-mvc-auth provides a configuration-driven approach for creating named adapters of these types. Each requires a unique key under the zf-mvc-auth.authentication.adapters configuration, and each type has its own format.

return [
    /* ... */
    'zf-mvc-auth' => [
        'authentication' => [
            'adapters' => [
                'api' => [
                    // This defines an HTTP adapter that can satisfy both
                    // basic and digest.
                    'adapter' => 'ZF\MvcAuth\Authentication\HttpAdapter',
                    'options' => [
                        'accept_schemes' => ['basic', 'digest'],
                        'realm' => 'api',
                        'digest_domains' => 'https://example.com',
                        'nonce_timeout' => 3600,
                        'htpasswd' => 'data/htpasswd',
                        'htdigest' => 'data/htdigest',
                    ],
                ],
                'user' => [
                    // This defines an OAuth2 adapter backed by PDO.
                    'adapter' => 'ZF\MvcAuth\Authentication\OAuth2Adapter',
                    'storage' => [
                        'adapter' => 'pdo',
                        'dsn' => 'mysql:host=localhost;dbname=oauth2',
                        'username' => 'username',
                        'password' => 'password',
                        'options' => [
                            1002 => 'SET NAMES utf8', // PDO::MYSQL_ATTR_INIT_COMMAND
                        ],
                    ],
                ],
                'client' => [
                    // This defines an OAuth2 adapter backed by Mongo.
                    'adapter' => 'ZF\MvcAuth\Authentication\OAuth2Adapter',
                    'storage' => [
                        'adapter' => 'mongo',
                        'locator_name' => 'SomeServiceName', // If provided, pulls the given service
                        'dsn' => 'mongodb://localhost',
                        'database' => 'oauth2',
                        'options' => [
                            'username' => 'username',
                            'password' => 'password',
                            'connectTimeoutMS' => 500,
                        ],
                    ],
                ],
            ],
            /* ... */
        ],
        /* ... */
    ],
    /* ... */
];

The above configuration would provide the authentication types ['api-basic', 'api-digest', 'user', 'client'] to your application, which can each them be associated in the authentication type map.

If you use zf-apigility-admin's Admin API and/or the Apigility UI to configure authentication adapters, the above configuration will be created for you.

Attaching an adapter during an event listener

The best event to attach to in this circumstances is the "authentication" event. When doing so, you'll want to attach at a priority > 1 to ensure it executes before the DefaultAuthenticationListener.

In the following example, we'll assume you've defined a service named MyCustomAuthenticationAdapter that returns an AdapterInterface implementation, and that the class is the Module class of your API or a module in your application.

class Module
{
    public function onBootstrap($e)
    {
        $app      = $e->getApplication();
        $events   = $app->getEventManager();
        $services = $app->getServiceManager();

        $events->attach(
            'authentication',
            function ($e) use ($services) {
                $listener = $services->get('ZF\MvcAuth\Authentication\DefaultAuthenticationListener')
                $adapter = $services->get('MyCustomAuthenticationAdapter');
                $listener->attach($adapter);
            },
            1000
        );
    }
}

By returning nothing, the DefaultAuthenticationListener will continue to execute, but will now also have the new adapter attached.

Using a delegator factory

Delegator Factories are a way to "decorate" an instance returned by the Zend Framework ServiceManager in order to provide pre-conditions or alter the instance normally returned. In our case, we want to attach an adapter after the instance is created, but before it's returned.

In the following example, we'll assume you've defined a service named MyCustomAuthenticationAdapter that returns an AdapterInterface implementation. The following is a delegator factory for the DefaultAuthenticationListener that will inject our adapter.

use Zend\ServiceManager\DelegatorFactoryInterface;
use Zend\ServiceManager\ServiceLocatorInterface;

class CustomAuthenticationDelegatorFactory implements DelegatorFactoryInterface
{
    public function createDelegatorWithName(
        ServiceLocatorInterface $services,
        $name,
        $requestedName,
        $callback
    ) {
        $listener  = $callback();
        $listener->attach($services->get('MyCustomAuthenticationAdapter');
        return $listener;
    }
}

We then need to tell the ServiceManager about the delegator factory; we do this in our module's config/module.config.php, or one of the config/autoload/ configuration files:

return [
    /* ... */
    'service_manager' => [
        /* ... */
        'delegators' => [
            'ZF\MvcAuth\Authentication\DefaultAuthenticationListener' => [
                'CustomAuthenticationDelegatorFactory',
            ],
        ],
    ],
    /* ... */
];

Once configured, our adapter will be attached to every instance of the DefaultAuthenticationListener that is retrieved.