HTTP digest authentication

The digest http authentication does not allow to use a password storing
systems, that do not successively allow to retrieve it, even if hashed

include/AddonAuthentication.php

@@ -0,0 +1,43 @@
+<?php
+
+/* 
+ * This class requires only DB functionalities from CI
+ * CI_Hack couldn't be included here because this class is called every time an addon
+ * makes an API call, so it would raise a lot of "already declared" errors
+ */
+require_once('/var/www/fhc/fhcomplete/vendor/codeigniter/framework/system/core/Model.php');
+require_once(dirname(__FILE__).'/../application/core/FHC_Model.php');
+
+/**
+ * This class is used to authenticate the addons on the core system
+ */
+class AddonAuthentication extends DB_Model
+{
+	public function __construct()
+	{
+		parent::__construct(NULL);
+	}
+
+	/**
+	 * It retrieves the password with the given username from ci_addons table
+	 * CREATE TABLE ci_addons (
+	 *	username       varchar(10),
+	 *	password       varchar(40),
+	 *	enabled        integer,
+	 *	CONSTRAINT ci_addons_pk UNIQUE(username));
+	 */
+	public function getPasswordByUsername($username)
+	{
+		$password = NULL;
+		$sql = "SELECT password FROM public.ci_addons WHERE enabled = 1 AND username = ?";
+		
+		$result = $this->db->query($sql, array($username));
+		
+		if(!is_null($result) && $result->num_rows() > 0)
+		{
+			$password = $result->row()->password;
+		}
+		
+		return $password;
+	}
+}