Framework files moved to lib/Roundcube

1 files changed, 1227 insertions, 0 deletions

diff --git a/program/lib/Roundcube/rcube.php b/program/lib/Roundcube/rcube.php
new file mode 100644
index 000000000..9c1a6d84a
--- /dev/null
+++ b/program/lib/Roundcube/rcube.php
@@ -0,0 +1,1227 @@
+<?php
+
+/*
+ +-----------------------------------------------------------------------+
+ | program/include/rcube.php                                             |
+ |                                                                       |
+ | This file is part of the Roundcube Webmail client                     |
+ | Copyright (C) 2008-2012, The Roundcube Dev Team                       |
+ | Copyright (C) 2011-2012, Kolab Systems AG                             |
+ |                                                                       |
+ | Licensed under the GNU General Public License version 3 or            |
+ | any later version with exceptions for skins & plugins.                |
+ | See the README file for a full license statement.                     |
+ |                                                                       |
+ | PURPOSE:                                                              |
+ |   Framework base class providing core functions and holding           |
+ |   instances of all 'global' objects like db- and storage-connections  |
+ +-----------------------------------------------------------------------+
+ | Author: Thomas Bruederli <roundcube@gmail.com>                        |
+ +-----------------------------------------------------------------------+
+*/
+
+
+/**
+ * Base class of the Roundcube Framework
+ * implemented as singleton
+ *
+ * @package    Framework
+ * @subpackage Core
+ */
+class rcube
+{
+    const INIT_WITH_DB = 1;
+    const INIT_WITH_PLUGINS = 2;
+
+    /**
+     * Singleton instace of rcube
+     *
+     * @var rcmail
+     */
+    static protected $instance;
+
+    /**
+     * Stores instance of rcube_config.
+     *
+     * @var rcube_config
+     */
+    public $config;
+
+    /**
+     * Instace of database class.
+     *
+     * @var rcube_db
+     */
+    public $db;
+
+    /**
+     * Instace of Memcache class.
+     *
+     * @var Memcache
+     */
+    public $memcache;
+
+   /**
+     * Instace of rcube_session class.
+     *
+     * @var rcube_session
+     */
+    public $session;
+
+    /**
+     * Instance of rcube_smtp class.
+     *
+     * @var rcube_smtp
+     */
+    public $smtp;
+
+    /**
+     * Instance of rcube_storage class.
+     *
+     * @var rcube_storage
+     */
+    public $storage;
+
+    /**
+     * Instance of rcube_output class.
+     *
+     * @var rcube_output
+     */
+    public $output;
+
+    /**
+     * Instance of rcube_plugin_api.
+     *
+     * @var rcube_plugin_api
+     */
+    public $plugins;
+
+
+    /* private/protected vars */
+    protected $texts;
+    protected $caches = array();
+    protected $shutdown_functions = array();
+    protected $expunge_cache = false;
+
+
+    /**
+     * This implements the 'singleton' design pattern
+     *
+     * @param integer Options to initialize with this instance. See rcube::INIT_WITH_* constants
+     *
+     * @return rcube The one and only instance
+     */
+    static function get_instance($mode = 0)
+    {
+        if (!self::$instance) {
+            self::$instance = new rcube();
+            self::$instance->init($mode);
+        }
+
+        return self::$instance;
+    }
+
+
+    /**
+     * Private constructor
+     */
+    protected function __construct()
+    {
+        // load configuration
+        $this->config  = new rcube_config;
+        $this->plugins = new rcube_dummy_plugin_api;
+
+        register_shutdown_function(array($this, 'shutdown'));
+    }
+
+
+    /**
+     * Initial startup function
+     */
+    protected function init($mode = 0)
+    {
+        // initialize syslog
+        if ($this->config->get('log_driver') == 'syslog') {
+            $syslog_id       = $this->config->get('syslog_id', 'roundcube');
+            $syslog_facility = $this->config->get('syslog_facility', LOG_USER);
+            openlog($syslog_id, LOG_ODELAY, $syslog_facility);
+        }
+
+        // connect to database
+        if ($mode & self::INIT_WITH_DB) {
+            $this->get_dbh();
+        }
+
+        // create plugin API and load plugins
+        if ($mode & self::INIT_WITH_PLUGINS) {
+            $this->plugins = rcube_plugin_api::get_instance();
+        }
+    }
+
+
+    /**
+     * Get the current database connection
+     *
+     * @return rcube_db Database object
+     */
+    public function get_dbh()
+    {
+        if (!$this->db) {
+            $config_all = $this->config->all();
+            $this->db = rcube_db::factory($config_all['db_dsnw'], $config_all['db_dsnr'], $config_all['db_persistent']);
+            $this->db->set_debug((bool)$config_all['sql_debug']);
+        }
+
+        return $this->db;
+    }
+
+
+    /**
+     * Get global handle for memcache access
+     *
+     * @return object Memcache
+     */
+    public function get_memcache()
+    {
+        if (!isset($this->memcache)) {
+            // no memcache support in PHP
+            if (!class_exists('Memcache')) {
+                $this->memcache = false;
+                return false;
+            }
+
+            $this->memcache     = new Memcache;
+            $this->mc_available = 0;
+
+            // add all configured hosts to pool
+            $pconnect = $this->config->get('memcache_pconnect', true);
+            foreach ($this->config->get('memcache_hosts', array()) as $host) {
+                if (substr($host, 0, 7) != 'unix://') {
+                    list($host, $port) = explode(':', $host);
+                    if (!$port) $port = 11211;
+                }
+                else {
+                    $port = 0;
+                }
+
+                $this->mc_available += intval($this->memcache->addServer(
+                    $host, $port, $pconnect, 1, 1, 15, false, array($this, 'memcache_failure')));
+            }
+
+            // test connection and failover (will result in $this->mc_available == 0 on complete failure)
+            $this->memcache->increment('__CONNECTIONTEST__', 1);  // NOP if key doesn't exist
+
+            if (!$this->mc_available) {
+                $this->memcache = false;
+            }
+        }
+
+        return $this->memcache;
+    }
+
+
+    /**
+     * Callback for memcache failure
+     */
+    public function memcache_failure($host, $port)
+    {
+        static $seen = array();
+
+        // only report once
+        if (!$seen["$host:$port"]++) {
+            $this->mc_available--;
+            self::raise_error(array(
+                'code' => 604, 'type' => 'db',
+                'line' => __LINE__, 'file' => __FILE__,
+                'message' => "Memcache failure on host $host:$port"),
+                true, false);
+        }
+    }
+
+
+    /**
+     * Initialize and get cache object
+     *
+     * @param string $name   Cache identifier
+     * @param string $type   Cache type ('db', 'apc' or 'memcache')
+     * @param string $ttl    Expiration time for cache items
+     * @param bool   $packed Enables/disables data serialization
+     *
+     * @return rcube_cache Cache object
+     */
+    public function get_cache($name, $type='db', $ttl=0, $packed=true)
+    {
+        if (!isset($this->caches[$name]) && ($userid = $this->get_user_id())) {
+            $this->caches[$name] = new rcube_cache($type, $userid, $name, $ttl, $packed);
+        }
+
+        return $this->caches[$name];
+    }
+
+
+    /**
+     * Create SMTP object and connect to server
+     *
+     * @param boolean True if connection should be established
+     */
+    public function smtp_init($connect = false)
+    {
+        $this->smtp = new rcube_smtp();
+
+        if ($connect) {
+            $this->smtp->connect();
+        }
+    }
+
+
+    /**
+     * Initialize and get storage object
+     *
+     * @return rcube_storage Storage object
+     */
+    public function get_storage()
+    {
+        // already initialized
+        if (!is_object($this->storage)) {
+            $this->storage_init();
+        }
+
+        return $this->storage;
+    }
+
+
+    /**
+     * Initialize storage object
+     */
+    public function storage_init()
+    {
+        // already initialized
+        if (is_object($this->storage)) {
+            return;
+        }
+
+        $driver       = $this->config->get('storage_driver', 'imap');
+        $driver_class = "rcube_{$driver}";
+
+        if (!class_exists($driver_class)) {
+            self::raise_error(array(
+                'code' => 700, 'type' => 'php',
+                'file' => __FILE__, 'line' => __LINE__,
+                'message' => "Storage driver class ($driver) not found!"),
+                true, true);
+        }
+
+        // Initialize storage object
+        $this->storage = new $driver_class;
+
+        // for backward compat. (deprecated, will be removed)
+        $this->imap = $this->storage;
+
+        // enable caching of mail data
+        $storage_cache  = $this->config->get("{$driver}_cache");
+        $messages_cache = $this->config->get('messages_cache');
+        // for backward compatybility
+        if ($storage_cache === null && $messages_cache === null && $this->config->get('enable_caching')) {
+            $storage_cache  = 'db';
+            $messages_cache = true;
+        }
+
+        if ($storage_cache) {
+            $this->storage->set_caching($storage_cache);
+        }
+        if ($messages_cache) {
+            $this->storage->set_messages_caching(true);
+        }
+
+        // set pagesize from config
+        $pagesize = $this->config->get('mail_pagesize');
+        if (!$pagesize) {
+            $pagesize = $this->config->get('pagesize', 50);
+        }
+        $this->storage->set_pagesize($pagesize);
+
+        // set class options
+        $options = array(
+            'auth_type'   => $this->config->get("{$driver}_auth_type", 'check'),
+            'auth_cid'    => $this->config->get("{$driver}_auth_cid"),
+            'auth_pw'     => $this->config->get("{$driver}_auth_pw"),
+            'debug'       => (bool) $this->config->get("{$driver}_debug"),
+            'force_caps'  => (bool) $this->config->get("{$driver}_force_caps"),
+            'timeout'     => (int) $this->config->get("{$driver}_timeout"),
+            'skip_deleted' => (bool) $this->config->get('skip_deleted'),
+            'driver'      => $driver,
+        );
+
+        if (!empty($_SESSION['storage_host'])) {
+            $options['host']     = $_SESSION['storage_host'];
+            $options['user']     = $_SESSION['username'];
+            $options['port']     = $_SESSION['storage_port'];
+            $options['ssl']      = $_SESSION['storage_ssl'];
+            $options['password'] = $this->decrypt($_SESSION['password']);
+            $_SESSION[$driver.'_host'] = $_SESSION['storage_host'];
+        }
+
+        $options = $this->plugins->exec_hook("storage_init", $options);
+
+        // for backward compat. (deprecated, to be removed)
+        $options = $this->plugins->exec_hook("imap_init", $options);
+
+        $this->storage->set_options($options);
+        $this->set_storage_prop();
+    }
+
+
+    /**
+     * Set storage parameters.
+     * This must be done AFTER connecting to the server!
+     */
+    protected function set_storage_prop()
+    {
+        $storage = $this->get_storage();
+
+        $storage->set_charset($this->config->get('default_charset', RCMAIL_CHARSET));
+
+        if ($default_folders = $this->config->get('default_folders')) {
+            $storage->set_default_folders($default_folders);
+        }
+        if (isset($_SESSION['mbox'])) {
+            $storage->set_folder($_SESSION['mbox']);
+        }
+        if (isset($_SESSION['page'])) {
+            $storage->set_page($_SESSION['page']);
+        }
+    }
+
+
+    /**
+     * Create session object and start the session.
+     */
+    public function session_init()
+    {
+        // session started (Installer?)
+        if (session_id()) {
+            return;
+        }
+
+        $sess_name   = $this->config->get('session_name');
+        $sess_domain = $this->config->get('session_domain');
+        $sess_path   = $this->config->get('session_path');
+        $lifetime    = $this->config->get('session_lifetime', 0) * 60;
+
+        // set session domain
+        if ($sess_domain) {
+            ini_set('session.cookie_domain', $sess_domain);
+        }
+        // set session path
+        if ($sess_path) {
+            ini_set('session.cookie_path', $sess_path);
+        }
+        // set session garbage collecting time according to session_lifetime
+        if ($lifetime) {
+            ini_set('session.gc_maxlifetime', $lifetime * 2);
+        }
+
+        ini_set('session.cookie_secure', rcube_utils::https_check());
+        ini_set('session.name', $sess_name ? $sess_name : 'roundcube_sessid');
+        ini_set('session.use_cookies', 1);
+        ini_set('session.use_only_cookies', 1);
+        ini_set('session.serialize_handler', 'php');
+        ini_set('session.cookie_httponly', 1);
+
+        // use database for storing session data
+        $this->session = new rcube_session($this->get_dbh(), $this->config);
+
+        $this->session->register_gc_handler(array($this, 'temp_gc'));
+        $this->session->register_gc_handler(array($this, 'cache_gc'));
+
+        $this->session->set_secret($this->config->get('des_key') . dirname($_SERVER['SCRIPT_NAME']));
+        $this->session->set_ip_check($this->config->get('ip_check'));
+
+        // start PHP session (if not in CLI mode)
+        if ($_SERVER['REMOTE_ADDR']) {
+            session_start();
+        }
+    }
+
+
+    /**
+     * Garbage collector function for temp files.
+     * Remove temp files older than two days
+     */
+    public function temp_gc()
+    {
+        $tmp = unslashify($this->config->get('temp_dir'));
+        $expire = time() - 172800;  // expire in 48 hours
+
+        if ($tmp && ($dir = opendir($tmp))) {
+            while (($fname = readdir($dir)) !== false) {
+                if ($fname{0} == '.') {
+                    continue;
+                }
+
+                if (filemtime($tmp.'/'.$fname) < $expire) {
+                    @unlink($tmp.'/'.$fname);
+                }
+            }
+
+            closedir($dir);
+        }
+    }
+
+
+    /**
+     * Garbage collector for cache entries.
+     * Set flag to expunge caches on shutdown
+     */
+    public function cache_gc()
+    {
+        // because this gc function is called before storage is initialized,
+        // we just set a flag to expunge storage cache on shutdown.
+        $this->expunge_cache = true;
+    }
+
+
+    /**
+     * Get localized text in the desired language
+     *
+     * @param mixed   $attrib  Named parameters array or label name
+     * @param string  $domain  Label domain (plugin) name
+     *
+     * @return string Localized text
+     */
+    public function gettext($attrib, $domain=null)
+    {
+        // load localization files if not done yet
+        if (empty($this->texts)) {
+            $this->load_language();
+        }
+
+        // extract attributes
+        if (is_string($attrib)) {
+            $attrib = array('name' => $attrib);
+        }
+
+        $name = $attrib['name'] ? $attrib['name'] : '';
+
+        // attrib contain text values: use them from now
+        if (($setval = $attrib[strtolower($_SESSION['language'])]) || ($setval = $attrib['en_us'])) {
+            $this->texts[$name] = $setval;
+        }
+
+        // check for text with domain
+        if ($domain && ($text = $this->texts[$domain.'.'.$name])) {
+        }
+        // text does not exist
+        else if (!($text = $this->texts[$name])) {
+            return "[$name]";
+        }
+
+        // replace vars in text
+        if (is_array($attrib['vars'])) {
+            foreach ($attrib['vars'] as $var_key => $var_value) {
+                $text = str_replace($var_key[0]!='$' ? '$'.$var_key : $var_key, $var_value, $text);
+            }
+        }
+
+        // format output
+        if (($attrib['uppercase'] && strtolower($attrib['uppercase'] == 'first')) || $attrib['ucfirst']) {
+            return ucfirst($text);
+        }
+        else if ($attrib['uppercase']) {
+            return mb_strtoupper($text);
+        }
+        else if ($attrib['lowercase']) {
+            return mb_strtolower($text);
+        }
+
+        return strtr($text, array('\n' => "\n"));
+    }
+
+
+    /**
+     * Check if the given text label exists
+     *
+     * @param string  $name       Label name
+     * @param string  $domain     Label domain (plugin) name or '*' for all domains
+     * @param string  $ref_domain Sets domain name if label is found
+     *
+     * @return boolean True if text exists (either in the current language or in en_US)
+     */
+    public function text_exists($name, $domain = null, &$ref_domain = null)
+    {
+        // load localization files if not done yet
+        if (empty($this->texts)) {
+            $this->load_language();
+        }
+
+        if (isset($this->texts[$name])) {
+            $ref_domain = '';
+            return true;
+        }
+
+        // any of loaded domains (plugins)
+        if ($domain == '*') {
+            foreach ($this->plugins->loaded_plugins() as $domain) {
+                if (isset($this->texts[$domain.'.'.$name])) {
+                    $ref_domain = $domain;
+                    return true;
+                }
+            }
+        }
+        // specified domain
+        else if ($domain) {
+            $ref_domain = $domain;
+            return isset($this->texts[$domain.'.'.$name]);
+        }
+
+        return false;
+    }
+
+
+    /**
+     * Load a localization package
+     *
+     * @param string Language ID
+     * @param array  Additional text labels/messages
+     */
+    public function load_language($lang = null, $add = array())
+    {
+        $lang = $this->language_prop(($lang ? $lang : $_SESSION['language']));
+
+        // load localized texts
+        if (empty($this->texts) || $lang != $_SESSION['language']) {
+            $this->texts = array();
+
+            // handle empty lines after closing PHP tag in localization files
+            ob_start();
+
+            // get english labels (these should be complete)
+            @include(INSTALL_PATH . 'program/localization/en_US/labels.inc');
+            @include(INSTALL_PATH . 'program/localization/en_US/messages.inc');
+
+            if (is_array($labels))
+                $this->texts = $labels;
+            if (is_array($messages))
+                $this->texts = array_merge($this->texts, $messages);
+
+            // include user language files
+            if ($lang != 'en' && $lang != 'en_US' && is_dir(INSTALL_PATH . 'program/localization/' . $lang)) {
+                include_once(INSTALL_PATH . 'program/localization/' . $lang . '/labels.inc');
+                include_once(INSTALL_PATH . 'program/localization/' . $lang . '/messages.inc');
+
+                if (is_array($labels))
+                    $this->texts = array_merge($this->texts, $labels);
+                if (is_array($messages))
+                    $this->texts = array_merge($this->texts, $messages);
+            }
+
+            ob_end_clean();
+
+            $_SESSION['language'] = $lang;
+        }
+
+        // append additional texts (from plugin)
+        if (is_array($add) && !empty($add)) {
+            $this->texts += $add;
+        }
+    }
+
+
+    /**
+     * Check the given string and return a valid language code
+     *
+     * @param string Language code
+     *
+     * @return string Valid language code
+     */
+    protected function language_prop($lang)
+    {
+        static $rcube_languages, $rcube_language_aliases;
+
+        // user HTTP_ACCEPT_LANGUAGE if no language is specified
+        if (empty($lang) || $lang == 'auto') {
+            $accept_langs = explode(',', $_SERVER['HTTP_ACCEPT_LANGUAGE']);
+            $lang         = str_replace('-', '_', $accept_langs[0]);
+        }
+
+        if (empty($rcube_languages)) {
+            @include(INSTALL_PATH . 'program/localization/index.inc');
+        }
+
+        // check if we have an alias for that language
+        if (!isset($rcube_languages[$lang]) && isset($rcube_language_aliases[$lang])) {
+            $lang = $rcube_language_aliases[$lang];
+        }
+        // try the first two chars
+        else if (!isset($rcube_languages[$lang])) {
+            $short = substr($lang, 0, 2);
+
+            // check if we have an alias for the short language code
+            if (!isset($rcube_languages[$short]) && isset($rcube_language_aliases[$short])) {
+                $lang = $rcube_language_aliases[$short];
+            }
+            // expand 'nn' to 'nn_NN'
+            else if (!isset($rcube_languages[$short])) {
+                $lang = $short.'_'.strtoupper($short);
+            }
+        }
+
+        if (!isset($rcube_languages[$lang]) || !is_dir(INSTALL_PATH . 'program/localization/' . $lang)) {
+            $lang = 'en_US';
+        }
+
+        return $lang;
+    }
+
+
+    /**
+     * Read directory program/localization and return a list of available languages
+     *
+     * @return array List of available localizations
+     */
+    public function list_languages()
+    {
+        static $sa_languages = array();
+
+        if (!sizeof($sa_languages)) {
+            @include(INSTALL_PATH . 'program/localization/index.inc');
+
+            if ($dh = @opendir(INSTALL_PATH . 'program/localization')) {
+                while (($name = readdir($dh)) !== false) {
+                    if ($name[0] == '.' || !is_dir(INSTALL_PATH . 'program/localization/' . $name)) {
+                        continue;
+                    }
+
+                    if ($label = $rcube_languages[$name]) {
+                        $sa_languages[$name] = $label;
+                    }
+                }
+                closedir($dh);
+            }
+        }
+
+        return $sa_languages;
+    }
+
+
+    /**
+     * Encrypt using 3DES
+     *
+     * @param string $clear clear text input
+     * @param string $key encryption key to retrieve from the configuration, defaults to 'des_key'
+     * @param boolean $base64 whether or not to base64_encode() the result before returning
+     *
+     * @return string encrypted text
+     */
+    public function encrypt($clear, $key = 'des_key', $base64 = true)
+    {
+        if (!$clear) {
+            return '';
+        }
+
+        /*-
+         * Add a single canary byte to the end of the clear text, which
+         * will help find out how much of padding will need to be removed
+         * upon decryption; see http://php.net/mcrypt_generic#68082
+         */
+        $clear = pack("a*H2", $clear, "80");
+
+        if (function_exists('mcrypt_module_open') &&
+            ($td = mcrypt_module_open(MCRYPT_TripleDES, "", MCRYPT_MODE_CBC, ""))
+        ) {
+            $iv = $this->create_iv(mcrypt_enc_get_iv_size($td));
+            mcrypt_generic_init($td, $this->config->get_crypto_key($key), $iv);
+            $cipher = $iv . mcrypt_generic($td, $clear);
+            mcrypt_generic_deinit($td);
+            mcrypt_module_close($td);
+        }
+        else {
+            @include_once 'des.inc';
+
+            if (function_exists('des')) {
+                $des_iv_size = 8;
+                $iv = $this->create_iv($des_iv_size);
+                $cipher = $iv . des($this->config->get_crypto_key($key), $clear, 1, 1, $iv);
+            }
+            else {
+                self::raise_error(array(
+                    'code' => 500, 'type' => 'php',
+                    'file' => __FILE__, 'line' => __LINE__,
+                    'message' => "Could not perform encryption; make sure Mcrypt is installed or lib/des.inc is available"
+                    ), true, true);
+            }
+        }
+
+        return $base64 ? base64_encode($cipher) : $cipher;
+    }
+
+
+    /**
+     * Decrypt 3DES-encrypted string
+     *
+     * @param string $cipher encrypted text
+     * @param string $key encryption key to retrieve from the configuration, defaults to 'des_key'
+     * @param boolean $base64 whether or not input is base64-encoded
+     *
+     * @return string decrypted text
+     */
+    public function decrypt($cipher, $key = 'des_key', $base64 = true)
+    {
+        if (!$cipher) {
+            return '';
+        }
+
+        $cipher = $base64 ? base64_decode($cipher) : $cipher;
+
+        if (function_exists('mcrypt_module_open') &&
+            ($td = mcrypt_module_open(MCRYPT_TripleDES, "", MCRYPT_MODE_CBC, ""))
+        ) {
+            $iv_size = mcrypt_enc_get_iv_size($td);
+            $iv = substr($cipher, 0, $iv_size);
+
+            // session corruption? (#1485970)
+            if (strlen($iv) < $iv_size) {
+                return '';
+            }
+
+            $cipher = substr($cipher, $iv_size);
+            mcrypt_generic_init($td, $this->config->get_crypto_key($key), $iv);
+            $clear = mdecrypt_generic($td, $cipher);
+            mcrypt_generic_deinit($td);
+            mcrypt_module_close($td);
+        }
+        else {
+            @include_once 'des.inc';
+
+            if (function_exists('des')) {
+                $des_iv_size = 8;
+                $iv = substr($cipher, 0, $des_iv_size);
+                $cipher = substr($cipher, $des_iv_size);
+                $clear = des($this->config->get_crypto_key($key), $cipher, 0, 1, $iv);
+            }
+            else {
+                self::raise_error(array(
+                    'code' => 500, 'type' => 'php',
+                    'file' => __FILE__, 'line' => __LINE__,
+                    'message' => "Could not perform decryption; make sure Mcrypt is installed or lib/des.inc is available"
+                    ), true, true);
+            }
+        }
+
+        /*-
+         * Trim PHP's padding and the canary byte; see note in
+         * rcube::encrypt() and http://php.net/mcrypt_generic#68082
+         */
+        $clear = substr(rtrim($clear, "\0"), 0, -1);
+
+        return $clear;
+    }
+
+
+    /**
+     * Generates encryption initialization vector (IV)
+     *
+     * @param int Vector size
+     *
+     * @return string Vector string
+     */
+    private function create_iv($size)
+    {
+        // mcrypt_create_iv() can be slow when system lacks entrophy
+        // we'll generate IV vector manually
+        $iv = '';
+        for ($i = 0; $i < $size; $i++) {
+            $iv .= chr(mt_rand(0, 255));
+        }
+
+        return $iv;
+    }
+
+
+    /**
+     * Build a valid URL to this instance of Roundcube
+     *
+     * @param mixed Either a string with the action or url parameters as key-value pairs
+     * @return string Valid application URL
+     */
+    public function url($p)
+    {
+        // STUB: should be overloaded by the application
+        return '';
+    }
+
+
+    /**
+     * Function to be executed in script shutdown
+     * Registered with register_shutdown_function()
+     */
+    public function shutdown()
+    {
+        foreach ($this->shutdown_functions as $function) {
+            call_user_func($function);
+        }
+
+        if (is_object($this->smtp)) {
+            $this->smtp->disconnect();
+        }
+
+        foreach ($this->caches as $cache) {
+            if (is_object($cache)) {
+                $cache->close();
+            }
+        }
+
+        if (is_object($this->storage)) {
+            if ($this->expunge_cache) {
+                $this->storage->expunge_cache();
+            }
+            $this->storage->close();
+        }
+    }
+
+
+    /**
+     * Registers shutdown function to be executed on shutdown.
+     * The functions will be executed before destroying any
+     * objects like smtp, imap, session, etc.
+     *
+     * @param callback Function callback
+     */
+    public function add_shutdown_function($function)
+    {
+        $this->shutdown_functions[] = $function;
+    }
+
+
+    /**
+     * Construct shell command, execute it and return output as string.
+     * Keywords {keyword} are replaced with arguments
+     *
+     * @param $cmd Format string with {keywords} to be replaced
+     * @param $values (zero, one or more arrays can be passed)
+     *
+     * @return output of command. shell errors not detectable
+     */
+    public static function exec(/* $cmd, $values1 = array(), ... */)
+    {
+        $args   = func_get_args();
+        $cmd    = array_shift($args);
+        $values = $replacements = array();
+
+        // merge values into one array
+        foreach ($args as $arg) {
+            $values += (array)$arg;
+        }
+
+        preg_match_all('/({(-?)([a-z]\w*)})/', $cmd, $matches, PREG_SET_ORDER);
+        foreach ($matches as $tags) {
+            list(, $tag, $option, $key) = $tags;
+            $parts = array();
+
+            if ($option) {
+                foreach ((array)$values["-$key"] as $key => $value) {
+                    if ($value === true || $value === false || $value === null) {
+                        $parts[] = $value ? $key : "";
+                    }
+                    else {
+                        foreach ((array)$value as $val) {
+                            $parts[] = "$key " . escapeshellarg($val);
+                        }
+                    }
+                }
+            }
+            else {
+                foreach ((array)$values[$key] as $value) {
+                    $parts[] = escapeshellarg($value);
+                }
+            }
+
+            $replacements[$tag] = join(" ", $parts);
+        }
+
+        // use strtr behaviour of going through source string once
+        $cmd = strtr($cmd, $replacements);
+
+        return (string)shell_exec($cmd);
+    }
+
+
+    /**
+     * Print or write debug messages
+     *
+     * @param mixed Debug message or data
+     */
+    public static function console()
+    {
+        $args = func_get_args();
+
+        if (class_exists('rcube', false)) {
+            $rcube = self::get_instance();
+            $plugin = $rcube->plugins->exec_hook('console', array('args' => $args));
+            if ($plugin['abort']) {
+                return;
+            }
+           $args = $plugin['args'];
+        }
+
+        $msg = array();
+        foreach ($args as $arg) {
+            $msg[] = !is_string($arg) ? var_export($arg, true) : $arg;
+        }
+
+        self::write_log('console', join(";\n", $msg));
+    }
+
+
+    /**
+     * Append a line to a logfile in the logs directory.
+     * Date will be added automatically to the line.
+     *
+     * @param $name name of log file
+     * @param line Line to append
+     */
+    public static function write_log($name, $line)
+    {
+        if (!is_string($line)) {
+            $line = var_export($line, true);
+        }
+
+        $date_format = self::$instance ? self::$instance->config->get('log_date_format') : null;
+        $log_driver  = self::$instance ? self::$instance->config->get('log_driver') : null;
+
+        if (empty($date_format)) {
+            $date_format = 'd-M-Y H:i:s O';
+        }
+
+        $date = date($date_format);
+
+        // trigger logging hook
+        if (is_object(self::$instance) && is_object(self::$instance->plugins)) {
+            $log  = self::$instance->plugins->exec_hook('write_log', array('name' => $name, 'date' => $date, 'line' => $line));
+            $name = $log['name'];
+            $line = $log['line'];
+            $date = $log['date'];
+            if ($log['abort'])
+                return true;
+        }
+
+        if ($log_driver == 'syslog') {
+            $prio = $name == 'errors' ? LOG_ERR : LOG_INFO;
+            syslog($prio, $line);
+            return true;
+        }
+
+        // log_driver == 'file' is assumed here
+
+        $line = sprintf("[%s]: %s\n", $date, $line);
+        $log_dir  = self::$instance ? self::$instance->config->get('log_dir') : null;
+
+        if (empty($log_dir)) {
+            $log_dir = INSTALL_PATH . 'logs';
+        }
+
+        // try to open specific log file for writing
+        $logfile = $log_dir.'/'.$name;
+
+        if ($fp = @fopen($logfile, 'a')) {
+            fwrite($fp, $line);
+            fflush($fp);
+            fclose($fp);
+            return true;
+        }
+
+        trigger_error("Error writing to log file $logfile; Please check permissions", E_USER_WARNING);
+        return false;
+    }
+
+
+    /**
+     * Throw system error (and show error page).
+     *
+     * @param array Named parameters
+     *      - code:    Error code (required)
+     *      - type:    Error type [php|db|imap|javascript] (required)
+     *      - message: Error message
+     *      - file:    File where error occured
+     *      - line:    Line where error occured
+     * @param boolean True to log the error
+     * @param boolean Terminate script execution
+     */
+    public static function raise_error($arg = array(), $log = false, $terminate = false)
+    {
+        // handle PHP exceptions
+        if (is_object($arg) && is_a($arg, 'Exception')) {
+            $err = array(
+                'type' => 'php',
+                'code' => $arg->getCode(),
+                'line' => $arg->getLine(),
+                'file' => $arg->getFile(),
+                'message' => $arg->getMessage(),
+            );
+            $arg = $err;
+        }
+
+        // installer
+        if (class_exists('rcube_install', false)) {
+            $rci = rcube_install::get_instance();
+            $rci->raise_error($arg);
+            return;
+        }
+
+        if (($log || $terminate) && $arg['type'] && $arg['message']) {
+            $arg['fatal'] = $terminate;
+            self::log_bug($arg);
+        }
+
+        // display error page and terminate script
+        if ($terminate && is_object(self::$instance->output)) {
+            self::$instance->output->raise_error($arg['code'], $arg['message']);
+        }
+    }
+
+
+    /**
+     * Report error according to configured debug_level
+     *
+     * @param array Named parameters
+     * @see self::raise_error()
+     */
+    public static function log_bug($arg_arr)
+    {
+        $program = strtoupper($arg_arr['type']);
+        $level   = self::get_instance()->config->get('debug_level');
+
+        // disable errors for ajax requests, write to log instead (#1487831)
+        if (($level & 4) && !empty($_REQUEST['_remote'])) {
+            $level = ($level ^ 4) | 1;
+        }
+
+        // write error to local log file
+        if (($level & 1) || !empty($arg_arr['fatal'])) {
+            if ($_SERVER['REQUEST_METHOD'] == 'POST') {
+                $post_query = '?_task='.urlencode($_POST['_task']).'&_action='.urlencode($_POST['_action']);
+            }
+            else {
+                $post_query = '';
+            }
+
+            $log_entry = sprintf("%s Error: %s%s (%s %s)",
+                $program,
+                $arg_arr['message'],
+                $arg_arr['file'] ? sprintf(' in %s on line %d', $arg_arr['file'], $arg_arr['line']) : '',
+                $_SERVER['REQUEST_METHOD'],
+                $_SERVER['REQUEST_URI'] . $post_query);
+
+            if (!self::write_log('errors', $log_entry)) {
+                // send error to PHPs error handler if write_log didn't succeed
+                trigger_error($arg_arr['message']);
+            }
+        }
+
+        // report the bug to the global bug reporting system
+        if ($level & 2) {
+            // TODO: Send error via HTTP
+        }
+
+        // show error if debug_mode is on
+        if ($level & 4) {
+            print "<b>$program Error";
+
+            if (!empty($arg_arr['file']) && !empty($arg_arr['line'])) {
+                print " in $arg_arr[file] ($arg_arr[line])";
+            }
+
+            print ':</b>&nbsp;';
+            print nl2br($arg_arr['message']);
+            print '<br />';
+            flush();
+        }
+    }
+
+
+    /**
+     * Returns current time (with microseconds).
+     *
+     * @return float Current time in seconds since the Unix
+     */
+    public static function timer()
+    {
+        return microtime(true);
+    }
+
+
+    /**
+     * Logs time difference according to provided timer
+     *
+     * @param float  $timer  Timer (self::timer() result)
+     * @param string $label  Log line prefix
+     * @param string $dest   Log file name
+     *
+     * @see self::timer()
+     */
+    public static function print_timer($timer, $label = 'Timer', $dest = 'console')
+    {
+        static $print_count = 0;
+
+        $print_count++;
+        $now  = self::timer();
+        $diff = $now - $timer;
+
+        if (empty($label)) {
+            $label = 'Timer '.$print_count;
+        }
+
+        self::write_log($dest, sprintf("%s: %0.4f sec", $label, $diff));
+    }
+
+
+    /**
+     * Getter for logged user ID.
+     *
+     * @return mixed User identifier
+     */
+    public function get_user_id()
+    {
+        if (is_object($this->user)) {
+            return $this->user->ID;
+        }
+        else if (isset($_SESSION['user_id'])) {
+            return $_SESSION['user_id'];
+        }
+
+        return null;
+    }
+
+
+    /**
+     * Getter for logged user name.
+     *
+     * @return string User name
+     */
+    public function get_user_name()
+    {
+        if (is_object($this->user)) {
+            return $this->user->get_username();
+        }
+
+        return null;
+    }
+}
+
+
+/**
+ * Lightweight plugin API class serving as a dummy if plugins are not enabled
+ *
+ * @package Core
+ */
+class rcube_dummy_plugin_api
+{
+    /**
+     * Triggers a plugin hook.
+     * @see rcube_plugin_api::exec_hook()
+     */
+    public function exec_hook($hook, $args = array())
+    {
+        return $args;
+    }
+}