Initial commit of Session/Authentication code

Plugin architecture with single Database-backed implementation.

source/lib/SihnonFramework/Auth/Plugin/Database.class.php

@@ -0,0 +1,83 @@
+<?php
+
+class SihnonFramework_Auth_Plugin_Database
+    extends    Sihnon_PluginBase 
+    implements Sihnon_Auth_IPlugin, 
+               Sihnon_Auth_IUpdateable, 
+               Sihnon_Auth_IFinelyPermissionable {
+
+    protected $config;
+    protected $database;
+    
+    protected function __construct($config) {
+        $this->config = $config;
+        $this->database = SihnonFramework_Main::instance()->database();
+    }
+    
+    /*
+     * IPlugin methods 
+     */
+    
+    public static function create(SihnonFramework_Config $config) {
+        return new self($config);
+    }
+    
+    public function userExists($username) {
+        return Sihnon_Auth_Plugin_Database_User::exists($username);
+    }
+    
+    public function listUsers() {
+        return Sihnon_Auth_Plugin_Database_User::all();
+    }
+    
+    public function authenticate($username, $password) {
+        $user = Sihnon_Auth_Plugin_Database_User::from('username', $username);
+        
+        if ( ! $user->checkPassword($password)) {
+            throw new Sihnon_Exception_IncorrectPassword();
+        }
+        
+        return $user;
+    }
+    
+    public function authenticateSession($username) {
+        return Sihnon_Auth_Plugin_Database_User::from('username', $username);
+    }
+    
+    /*
+     * IUpdateable methods
+     */
+    
+    public function addUser($username, $password) {
+        return Sihnon_Auth_Plugin_Database_User::add($username, $password);
+    }
+    
+    public function removeUser(Sihnon_Auth_IUser $user) {
+        $user->delete();
+    }
+    
+    public function changePassword(Sihnon_Auth_IUser $user, $new_password) {
+        $user->changePassword($new_password);
+    }
+    
+    /*
+     * IPermissionable methods
+     */
+    
+    public function isAdministrator(Sihnon_Auth_IUser $user) {
+        // As this class supports fine-grained permissions, map the isAdministrator function to the Superadmin privilege
+        // to fallback for badly written applications
+        return $user->hasPermission(Sihnon_Auth_Plugin_Database_Permission::PERM_Administrator);
+    }
+    
+    /*
+     * IFinelyPermissionable methods
+     */
+
+    public function hasPermission(Sihnon_Auth_IUser $user, $permission) {
+        return new $user->hasPermission($permission);
+    }
+    
+}
+
+?>