- Merge devel-framework branch, resolved conflicts

1 files changed, 1226 insertions, 0 deletions

diff --git a/program/include/rcube.php b/program/include/rcube.php
new file mode 100644
index 000000000..bee298620
--- /dev/null
+++ b/program/include/rcube.php
@@ -0,0 +1,1226 @@
+<?php
+
+/*
+ +-----------------------------------------------------------------------+
+ | program/include/rcmail.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>                        |
+ +-----------------------------------------------------------------------+
+
+ $Id$
+
+*/
+
+
+/**
+ * Base class of the Roundcube Framework
+ * implemented as singleton
+ *
+ * @package Core
+ */
+class rcube
+{
+  const INIT_WITH_DB = 1;
+  const INIT_WITH_PLUGINS = 2;
+
+  /**
+   * Singleton instace of rcmail
+   *
+   * @var rcmail
+   */
+  static protected $instance;
+
+  /**
+   * Stores instance of rcube_config.
+   *
+   * @var rcube_config
+   */
+  public $config;
+
+  /**
+   * Instace of database class.
+   *
+   * @var rcube_mdb2
+   */
+  public $db;
+
+  /**
+   * Instace of Memcache class.
+   *
+   * @var rcube_mdb2
+   */
+  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 $expunge_cache = false;
+
+
+  /**
+   * This implements the 'singleton' design pattern
+   *
+   * @return rcmail The one and only instance
+   */
+  static function get_instance()
+  {
+    if (!self::$instance) {
+      self::$instance = new rcube();
+    }
+
+    return self::$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) {
+      $this->plugins = rcube_plugin_api::get_instance();
+    }
+  }
+
+
+  /**
+   * Get the current database connection
+   *
+   * @return rcube_mdb2  Database connection object
+   */
+  public function get_dbh()
+  {
+    if (!$this->db) {
+      $config_all = $this->config->all();
+
+      $this->db = new rcube_mdb2($config_all['db_dsnw'], $config_all['db_dsnr'], $config_all['db_persistent']);
+      $this->db->sqlite_initials = INSTALL_PATH . 'SQL/sqlite.initial.sql';
+      $this->db->set_debug((bool)$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 alll configured hosts to pool
+      $pconnect = $this->config->get('memcache_pconnect', true);
+      foreach ($this->config->get('memcache_hosts', array()) as $host) {
+        list($host, $port) = explode(':', $host);
+        if (!$port) $port = 11211;
+        $this->mc_available += intval($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 int    $ttl    Expiration time for cache items in seconds
+   * @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])) {
+      $this->caches[$name] = new rcube_cache($type, $_SESSION['user_id'], $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']);
+    }
+
+    $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();
+  }
+
+
+  /**
+   * Connect to the mail storage server with stored session data
+   *
+   * @return bool True on success, False on error
+   */
+  public function storage_connect()
+  {
+    $storage = $this->get_storage();
+
+    if ($_SESSION['storage_host'] && !$storage->is_connected()) {
+      $host = $_SESSION['storage_host'];
+      $user = $_SESSION['username'];
+      $port = $_SESSION['storage_port'];
+      $ssl  = $_SESSION['storage_ssl'];
+      $pass = $this->decrypt($_SESSION['password']);
+
+      if (!$storage->connect($host, $user, $pass, $port, $ssl)) {
+        if (is_object($this->output))
+          $this->output->show_message($storage->get_error_code() == -1 ? 'storageerror' : 'sessionerror', 'error');
+      }
+      else {
+        $this->set_storage_prop();
+        return $storage->is_connected();
+      }
+    }
+
+    return false;
+  }
+
+  /**
+   * 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']);
+    }
+  }
+
+
+  /**
+   * 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
+   */
+  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' && 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
+     * rcmail::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[] = $function;
+  }
+
+
+  /**
+   * Use imagemagick or GD lib to read image properties
+   *
+   * @param string Absolute file path
+   * @return mixed Hash array with image props like type, width, height or False on error
+   */
+  public static function imageprops($filepath)
+  {
+    $rcube = self::get_instance();
+    if ($cmd = $rcube->config->get('im_identify_path', false)) {
+      list(, $type, $size) = explode(' ', strtolower(self::exec($cmd. ' 2>/dev/null {in}', array('in' => $filepath))));
+      if ($size)
+        list($width, $height) = explode('x', $size);
+    }
+    else if (function_exists('getimagesize')) {
+      $imsize = @getimagesize($filepath);
+      $width = $imsize[0];
+      $height = $imsize[1];
+      $type = preg_replace('!image/!', '', $imsize['mime']);
+    }
+
+    return $type ? array('type' => $type, 'width' => $width, 'height' => $height) : false;
+  }
+
+
+  /**
+   * Convert an image to a given size and type using imagemagick (ensures input is an image)
+   *
+   * @param $p['in']  Input filename (mandatory)
+   * @param $p['out'] Output filename (mandatory)
+   * @param $p['size']  Width x height of resulting image, e.g. "160x60"
+   * @param $p['type']  Output file type, e.g. "jpg"
+   * @param $p['-opts'] Custom command line options to ImageMagick convert
+   * @return Success of convert as true/false
+   */
+  public static function imageconvert($p)
+  {
+    $result = false;
+    $rcube = self::get_instance();
+    $convert  = $rcube->config->get('im_convert_path', false);
+    $identify = $rcube->config->get('im_identify_path', false);
+
+    // imagemagick is required for this
+    if (!$convert)
+        return false;
+
+    if (!(($imagetype = @exif_imagetype($p['in'])) && ($type = image_type_to_extension($imagetype, false))))
+      list(, $type) = explode(' ', strtolower(self::exec($identify . ' 2>/dev/null {in}', $p))); # for things like eps
+
+    $type = strtr($type, array("jpeg" => "jpg", "tiff" => "tif", "ps" => "eps", "ept" => "eps"));
+    $p += array('type' => $type, 'types' => "bmp,eps,gif,jp2,jpg,png,svg,tif", 'quality' => 75);
+    $p['-opts'] = array('-resize' => $p['size'].'>') + (array)$p['-opts'];
+
+    if (in_array($type, explode(',', $p['types']))) # Valid type?
+      $result = self::exec($convert . ' 2>&1 -flatten -auto-orient -colorspace RGB -quality {quality} {-opts} {in} {type}:{out}', $p) === "";
+
+    return $result;
+  }
+
+
+  /**
+   * 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);
+  }
+
+
+    /**
+     * Replaces hostname variables.
+     *
+     * @param string $name Hostname
+     * @param string $host Optional IMAP hostname
+     *
+     * @return string Hostname
+     */
+    public static function parse_host($name, $host = '')
+    {
+        // %n - host
+        $n = preg_replace('/:\d+$/', '', $_SERVER['SERVER_NAME']);
+        // %d - domain name without first part, e.g. %n=mail.domain.tld, %d=domain.tld
+        $d = preg_replace('/^[^\.]+\./', '', $n);
+        // %h - IMAP host
+        $h = $_SESSION['storage_host'] ? $_SESSION['storage_host'] : $host;
+        // %z - IMAP domain without first part, e.g. %h=imap.domain.tld, %z=domain.tld
+        $z = preg_replace('/^[^\.]+\./', '', $h);
+        // %s - domain name after the '@' from e-mail address provided at login screen. Returns FALSE if an invalid email is provided
+        if (strpos($name, '%s') !== false) {
+            $user_email = rcube_ui::get_input_value('_user', rcube_ui::INPUT_POST);
+            $user_email = rcube_idn_convert($user_email, true);
+            $matches    = preg_match('/(.*)@([a-z0-9\.\-\[\]\:]+)/i', $user_email, $s);
+            if ($matches < 1 || filter_var($s[1]."@".$s[2], FILTER_VALIDATE_EMAIL) === false) {
+                return false;
+            }
+        }
+
+        $name = str_replace(array('%n', '%d', '%h', '%z', '%s'), array($n, $d, $h, $z, $s[2]), $name);
+        return $name;
+    }
+
+
+    /**
+     * Print or write debug messages
+     *
+     * @param mixed Debug message or data
+     */
+    public static function console()
+    {
+        $args = func_get_args();
+
+        if (class_exists('rcmail', false)) {
+            $rcube = self::get_instance();
+            if (is_object($rcube->plugins)) {
+                $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)
+    {
+        // installer
+        if (class_exists('rcube_install', false)) {
+            $rci = rcube_install::get_instance();
+            $rci->raise_error($arg);
+            return;
+        }
+
+        if ($log && $arg['type'] && $arg['message']) {
+            self::log_bug($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 ($level & 1) {
+            if ($_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 remote IP address and forwarded addresses if found
+     *
+     * @return string Remote IP address(es)
+     */
+    public static function remote_ip()
+    {
+        $address = $_SERVER['REMOTE_ADDR'];
+
+        // append the NGINX X-Real-IP header, if set
+        if (!empty($_SERVER['HTTP_X_REAL_IP'])) {
+            $remote_ip[] = 'X-Real-IP: ' . $_SERVER['HTTP_X_REAL_IP'];
+        }
+        // append the X-Forwarded-For header, if set
+        if (!empty($_SERVER['HTTP_X_FORWARDED_FOR'])) {
+            $remote_ip[] = 'X-Forwarded-For: ' . $_SERVER['HTTP_X_FORWARDED_FOR'];
+        }
+
+        if (!empty($remote_ip)) {
+            $address .= '(' . implode(',', $remote_ip) . ')';
+        }
+
+        return $address;
+    }
+
+
+    /**
+     * 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 $this->user->ID;
+        }
+
+        return null;
+    }
+
+
+    /**
+     * Getter for logged user name.
+     *
+     * @return string User name
+     */
+    public function get_user_name()
+    {
+        if (is_object($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;
+    }
+}
+