Merge branch 'feature/5901' into develop

Close #5901

README.md

@@ -34,6 +34,10 @@ version of PHP available to ensure you have the latest security fixes.
 
 Additional updates that may affect existing applications include:
 
+- [#5901](https://github.com/zendframework/zf2/pull/5901) adds a new interface,
+  `Zend\Authentication\AuthenticationServiceInterface`. You can not type-hint
+  against this instead of `Zend\Authentication\AuthenticationService`.
+
 - [#5885](https://github.com/zendframework/zf2/pull/5885) adds the ability to
   specify the Locale via a route match parameter, and have it apply to the
   composed translator in the router, if any.

library/Zend/Authentication/AuthenticationService.php

@@ -9,7 +9,7 @@
 
 namespace Zend\Authentication;
 
-class AuthenticationService
+class AuthenticationService implements AuthenticationServiceInterface
 {
     /**
      * Persistent storage handler

library/Zend/Authentication/AuthenticationServiceInterface.php

@@ -0,0 +1,44 @@
+<?php
+/**
+ * Zend Framework (http://framework.zend.com/)
+ *
+ * @link      http://github.com/zendframework/zf2 for the canonical source repository
+ * @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
+ * @license   http://framework.zend.com/license/new-bsd New BSD License
+ */
+
+namespace Zend\Authentication;
+
+/**
+ * Provides an API for authentication and identity management
+ */
+interface AuthenticationServiceInterface
+{
+    /**
+     * Authenticates and provides an authentication result
+     *
+     * @return Result
+     */
+    public function authenticate();
+
+    /**
+     * Returns true if and only if an identity is available
+     *
+     * @return bool
+     */
+    public function hasIdentity();
+
+    /**
+     * Returns the authenticated identity or null if no identity is available
+     *
+     * @return mixed|null
+     */
+    public function getIdentity();
+
+    /**
+     * Clears the identity
+     *
+     * @return void
+     */
+    public function clearIdentity();
+}