diff -r 000000000000 -r 7f95f8617b0b vendor/symfony/src/Symfony/Component/Security/Http/Session/SessionAuthenticationStrategy.php
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/vendor/symfony/src/Symfony/Component/Security/Http/Session/SessionAuthenticationStrategy.php	Sat Sep 24 15:40:41 2011 +0200
@@ -0,0 +1,63 @@
+<?php
+
+/*
+ * This file is part of the Symfony framework.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * This source file is subject to the MIT license that is bundled
+ * with this source code in the file LICENSE.
+ */
+
+namespace Symfony\Component\Security\Http\Session;
+
+use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * The default session strategy implementation.
+ *
+ * Supports the following strategies:
+ * NONE: the session is not changed
+ * MIGRATE: the session id is updated, attributes are kept
+ * INVALIDATE: the session id is updated, attributes are lost
+ *
+ * @author Johannes M. Schmitt <schmittjoh@gmail.com>
+ */
+class SessionAuthenticationStrategy implements SessionAuthenticationStrategyInterface
+{
+    const NONE         = 'none';
+    const MIGRATE      = 'migrate';
+    const INVALIDATE   = 'invalidate';
+
+    private $strategy;
+
+    public function __construct($strategy)
+    {
+        $this->strategy = $strategy;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function onAuthentication(Request $request, TokenInterface $token)
+    {
+        switch ($this->strategy) {
+            case self::NONE:
+                return;
+
+            case self::MIGRATE:
+                $request->getSession()->migrate();
+
+                return;
+
+            case self::INVALIDATE:
+                $request->getSession()->invalidate();
+
+                return;
+
+            default:
+                throw new \RuntimeException(sprintf('Invalid session authentication strategy "%s"', $this->strategy));
+        }
+    }
+}