[ticket/12352] Use custom provider collection for auth providers

Using this custom provider collection, we can properly check whether the
configured auth provider does exist. The method get_provider() has been added
for returning the default auth provider or the standard db auth provider if
the specified one does not exist.
Additionally, the method get_provider() will throw an RuntimeException if
none of the above exist.

PHPBB3-12352

phpBB/config/auth_providers.yml

@@ -1,8 +1,9 @@
 services:
     auth.provider_collection:
-        class: phpbb\di\service_collection
+        class: phpbb\auth\provider_collection
         arguments:
             - @service_container
+            - @config
         tags:
             - { name: service_collection, tag: auth.provider }
     auth.provider.db:

phpBB/includes/functions.php

@@ -2855,15 +2855,7 @@ function login_box($redirect = '', $l_explain = '', $l_success = '', $admin = fa
 	}
 
 	$provider_collection = $phpbb_container->get('auth.provider_collection');
-	$auth_method = $config['auth_method'];
-
-	// Revert to db auth provider if selected method does not exist
-	if (!isset($provider_collection['auth.provider.' . $config['auth_method']]))
-	{
-		$auth_method = 'db';
-	}
-
-	$auth_provider = $provider_collection['auth.provider.' . $auth_method];
+	$auth_provider = $provider_collection->get_provider();
 
 	$auth_provider_data = $auth_provider->get_login_data();
 	if ($auth_provider_data)

phpBB/phpbb/auth/provider_collection.php

@@ -0,0 +1,63 @@
+<?php
+/**
+*
+* @package phpBB3
+* @copyright (c) 2014 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+namespace phpbb\auth;
+
+use Symfony\Component\DependencyInjection\ContainerInterface;
+
+/**
+* Collection of auth providers to be configured at container compile time.
+*
+* @package phpBB3
+*/
+class provider_collection extends \phpbb\di\service_collection
+{
+	/** @var \phpbb\config\config phpBB Config */
+	protected $config;
+
+	/**
+	* Constructor
+	*
+	* @param ContainerInterface $container Container object
+	* @param \phpbb\config\config $config phpBB config
+	*/
+	public function __construct($container, \phpbb\config\config $config)
+	{
+		$this->container = $container;
+		$this->config = $config;
+	}
+
+	/**
+	* Get an auth provider.
+	*
+	* @return object	Default auth provider selected in config if it
+	*			does exist. Otherwise the standard db auth
+	*			provider.
+	* @throws \RuntimeException If neither the auth provider that
+	*			is specified by the phpBB config nor the db
+	*			auth provider exist. The db auth provider
+	*			should always exist in a phpBB installation.
+	*/
+	public function get_provider()
+	{
+		if ($this->offsetExists('auth.provider.' . basename(trim($this->config['auth_method']))))
+		{
+			return $this->offsetGet('auth.provider.' . basename(trim($this->config['auth_method'])));
+		}
+		// Revert to db auth provider if selected method does not exist
+		elseif ($this->offsetExists('auth.provider.db'))
+		{
+			return $this->offsetGet('auth.provider.db');
+		}
+		else
+		{
+			throw new \RuntimeException(sprintf('The authentication provider for the authentication method "%1$s" does not exist. It was not possible to recover from this by reverting to the database authentication provider.', $this->config['auth_method']));
+		}
+	}
+}

phpBB/phpbb/session.php

@@ -408,16 +408,8 @@ class session
 					$session_expired = false;
 
 					// Check whether the session is still valid if we have one
-					$method = basename(trim($config['auth_method']));
-
 					$provider_collection = $phpbb_container->get('auth.provider_collection');
-
-					// Revert to db auth provider if selected method does not exist
-					if (!isset($provider_collection['auth.provider.' . $method]))
-					{
-						$method = 'db';
-					}
-					$provider = $provider_collection['auth.provider.' . $method];
+					$provider = $provider_collection->get_provider();
 
 					if (!($provider instanceof \phpbb\auth\provider\provider_interface))
 					{
@@ -584,16 +576,8 @@ class session
 			}
 		}
 
-		$method = basename(trim($config['auth_method']));
-
 		$provider_collection = $phpbb_container->get('auth.provider_collection');
-
-		// Revert to db auth provider if selected method does not exist
-		if (!isset($provider_collection['auth.provider.' . $method]))
-		{
-			$method = 'db';
-		}
-		$provider = $provider_collection['auth.provider.' . $method];
+		$provider = $provider_collection->get_provider();
 		$this->data = $provider->autologin();
 
 		if (sizeof($this->data))
@@ -912,9 +896,8 @@ class session
 		$db->sql_query($sql);
 
 		// Allow connecting logout with external auth method logout
-		$method = basename(trim($config['auth_method']));
-
-		$provider = $phpbb_container->get('auth.provider.' . $method);
+		$provider_collection = $phpbb_container->get('auth.provider_collection');
+		$provider = $provider_collection->get_provider();
 		$provider->logout($this->data, $new_session);
 
 		if ($this->data['user_id'] != ANONYMOUS)

tests/session/testable_factory.php

@@ -96,9 +96,11 @@ class phpbb_session_testable_factory
 			'auth.provider.db',
 			new phpbb_mock_auth_provider()
 		);
+		$provider_collection = new \phpbb\auth\provider_collection($phpbb_container, $config);
+		$provider_collection->add('auth.provider.db');
 		$phpbb_container->set(
 			'auth.provider_collection',
-			array('auth.provider.db' => $phpbb_container->get('auth.provider.db'))
+			$provider_collection
 		);
 
 		$session = new phpbb_mock_session_testable;