diff --git a/plugins/kolab_2fa/kolab_2fa.php b/plugins/kolab_2fa/kolab_2fa.php
index 906b2b7d..3fe87412 100644
--- a/plugins/kolab_2fa/kolab_2fa.php
+++ b/plugins/kolab_2fa/kolab_2fa.php
@@ -1,755 +1,756 @@
 <?php
 
 /**
  * Kolab 2-Factor-Authentication plugin
  *
  * ...
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2015, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 class kolab_2fa extends rcube_plugin
 {
     public $task = '(login|settings)';
 
     protected $login_verified = null;
     protected $login_factors = array();
     protected $drivers = array();
     protected $storage;
 
     /**
      * Plugin init
      */
     public function init()
     {
         $this->load_config();
         $this->add_hook('startup', array($this, 'startup'));
     }
 
     /**
      * Startup hook
      */
     public function startup($args)
     {
         $rcmail = rcmail::get_instance();
 
         // register library namespace to autoloader
         $loader = include(INSTALL_PATH . 'vendor/autoload.php');
         $loader->set('Kolab2FA', array($this->home . '/lib'));
 
         if ($args['task'] === 'login' && $this->api->output) {
             $this->add_texts('localization/', false);
             $this->add_hook('authenticate', array($this, 'authenticate'));
 
             // process 2nd factor auth step after regular login
             if ($args['action'] === 'plugin.kolab-2fa-login' /* || !empty($_SESSION['kolab_2fa_factors']) */) {
                 return $this->login_verify($args);
             }
         }
         else if ($args['task'] === 'settings') {
             $this->add_texts('localization/', !$this->api->output->ajax_call);
             $this->add_hook('settings_actions', array($this, 'settings_actions'));
             $this->register_action('plugin.kolab-2fa', array($this, 'settings_view'));
             $this->register_action('plugin.kolab-2fa-data', array($this, 'settings_data'));
             $this->register_action('plugin.kolab-2fa-save', array($this, 'settings_save'));
             $this->register_action('plugin.kolab-2fa-verify', array($this, 'settings_verify'));
         }
 
         return $args;
     }
 
     /**
      * Handler for 'authenticate' plugin hook.
      *
      * ATTENTION: needs to be called *after* kolab_auth::authenticate()
      */
     public function authenticate($args)
     {
         // nothing to be done for me
         if ($args['abort'] || $this->login_verified !== null) {
             return $args;
         }
 
         $rcmail = rcmail::get_instance();
 
         // parse $host URL
         $a_host = parse_url($args['host']);
         $hostname = $_SESSION['hostname'] = $a_host['host'] ?: $args['host'];
 
         // 1. find user record (and its prefs) before IMAP login
         if ($user = rcube_user::query($args['user'], $hostname)) {
             $rcmail->config->set_user_prefs($user->get_prefs());
         }
 
         // 2a. let plugins provide the list of active authentication factors
         $lookup = $rcmail->plugins->exec_hook('kolab_2fa_lookup', array(
             'user'    => $args['user'],
             'host'    => $hostname,
             'factors' => $rcmail->config->get('kolab_2fa_factors'),
             'check'   => $rcmail->config->get('kolab_2fa_check', true),
         ));
         if (isset($lookup['factors'])) {
             $factors = (array)$lookup['factors'];
         }
         // 2b. check storage if this user has 2FA enabled
         else if ($lookup['check'] !== false && ($storage = $this->get_storage($args['user']))) {
             $factors = (array)$storage->enumerate();
         }
 
         if (count($factors) > 0) {
             $args['abort'] = true;
             $factors = array_unique($factors);
 
             // 3. flag session for 2nd factor verification
             $_SESSION['kolab_2fa_time']    = time();
             $_SESSION['kolab_2fa_nonce']   = bin2hex(openssl_random_pseudo_bytes(32));
             $_SESSION['kolab_2fa_factors'] = $factors;
 
             $_SESSION['username'] = $args['user'];
             $_SESSION['host']     = $args['host'];
             $_SESSION['password'] = $rcmail->encrypt($args['pass']);
 
             // 4. render to 2nd auth step
             $this->login_step($factors);
         }
 
         return $args;
     }
 
     /**
      * Handler for the additional login step requesting the 2FA verification code
      */
     public function login_step($factors)
     {
         // replace handler for login form
         $this->login_factors = array_values($factors);
         $this->api->output->add_handler('loginform', array($this, 'auth_form'));
 
         // focus the code input field on load
         $this->api->output->add_script('$("input.kolab2facode").first().select();', 'docready');
 
         $this->api->output->send('login');
     }
 
     /**
      * Process the 2nd factor code verification form submission
      */
     public function login_verify($args)
     {
         $rcmail = rcmail::get_instance();
 
         $time  = $_SESSION['kolab_2fa_time'];
         $nonce = $_SESSION['kolab_2fa_nonce'];
         $factors = (array)$_SESSION['kolab_2fa_factors'];
 
         $this->login_verified = false;
         $expired = $time < time() - $rcmail->config->get('kolab_2fa_timeout', 120);
 
         if (!empty($factors) && !empty($nonce) && !$expired) {
             // TODO: check signature
 
             // try to verify each configured factor
             foreach ($factors as $factor) {
                 list($method) = explode(':', $factor, 2);
 
                 // verify the submitted code
                 $code = rcube_utils::get_input_value("_${nonce}_${method}", rcube_utils::INPUT_POST);
                 $this->login_verified = $this->verify_factor_auth($factor, $code);
 
                 // accept first successful method
                 if ($this->login_verified) {
                     break;
                 }
             }
         }
 
         if ($this->login_verified) {
             // restore POST data from session
             $_POST['_user'] = $_SESSION['username'];
             $_POST['_host'] = $_SESSION['host'];
             $_POST['_pass'] = $rcmail->decrypt($_SESSION['password']);
         }
 
         // proceed with regular login ...
         $args['action'] = 'login';
 
         // session data will be reset in index.php thus additional
         // auth attempts with intercepted data will be rejected
         // $rcmail->kill_session();
 
         // we can't display any custom error messages on failed login
         // but that's actually desired to expose as little information as possible
 
         return $args;
     }
     
     /**
      * Helper method to verify the given method/code tuple
      */
     protected function verify_factor_auth($method, $code)
     {
         if (strlen($code) && ($driver = $this->get_driver($method))) {
             // set properties from login
             $driver->username  = $_SESSION['username'];
 
             try {
                 // verify the submitted code
                 return $driver->verify($code, $_SESSION['kolab_2fa_time']);
             }
             catch (Exception $e) {
                 rcube::raise_error($e, true, false);
             }
         }
 
         return false;
     }
 
     /**
      * Render 2nd factor authentication form in place of the regular login form
      */
     public function auth_form($attrib = array())
     {
         $form_name  = !empty($attrib['form']) ? $attrib['form'] : 'form';
         $nonce = $_SESSION['kolab_2fa_nonce'];
 
         $methods = array_unique(array_map(function($factor) {
                 list($method, $id) = explode(':', $factor);
                 return $method;
             },
             $this->login_factors
         ));
 
         // forward these values as the regular login screen would submit them
         $input_task   = new html_hiddenfield(array('name' => '_task', 'value' => 'login'));
         $input_action = new html_hiddenfield(array('name' => '_action', 'value' => 'plugin.kolab-2fa-login'));
         $input_tzone  = new html_hiddenfield(array('name' => '_timezone', 'id' => 'rcmlogintz', 'value' => rcube_utils::get_input_value('_timezone', rcube_utils::INPUT_POST)));
         $input_url    = new html_hiddenfield(array('name' => '_url', 'id' => 'rcmloginurl', 'value' => rcube_utils::get_input_value('_url', rcube_utils::INPUT_POST)));
 
         // create HTML table with two cols
         $table = new html_table(array('cols' => 2));
         $required = count($methods) > 1 ? null : 'required';
 
         // render input for each configured auth method
         foreach ($methods as $i => $method) {
             if ($row++ > 0) {
                 $table->add(array('colspan' => 2, 'class' => 'title hint', 'style' => 'text-align:center'),
                     $this->gettext('or'));
             }
 
             $field_id = "rcmlogin2fa$method";
             $input_code = new html_inputfield(array('name' => "_${nonce}_${method}", 'class' => 'kolab2facode', 'id' => $field_id, 'required' => $required, 'autocomplete' => 'off')
                 + $attrib);
             $table->add('title', html::label($field_id, html::quote($this->gettext($method))));
             $table->add('input', $input_code->show(''));
         }
 
         $out  = $input_task->show();
         $out .= $input_action->show();
         $out .= $input_tzone->show();
         $out .= $input_url->show();
         $out .= $table->show();
 
         // add submit button
         if (rcube_utils::get_boolean($attrib['submit'])) {
             $submit = new html_inputfield(array('type' => 'submit', 'id' => 'rcmloginsubmit',
                 'class' => 'button mainaction', 'value' => $this->gettext('continue')));
             $out .= html::p('formbuttons', $submit->show());
         }
 
         // surround html output with a form tag
         if (empty($attrib['form'])) {
             $out = $this->api->output->form_tag(array('name' => $form_name, 'method' => 'post'), $out);
         }
 
         return $out;
     }
 
     /**
      * Load driver class for the given method
      */
     public function get_driver($method)
     {
         $rcmail = rcmail::get_instance();
 
         if ($this->drivers[$method]) {
             return $this->drivers[$method];
         }
 
         $config = $rcmail->config->get('kolab_2fa_' . $method, array());
 
         // use product name as "issuer""
         if (empty($config['issuer'])) {
             $config['issuer'] = $rcmail->config->get('product_name');
         }
 
         try {
             // TODO: use external auth service if configured
 
             $driver = \Kolab2FA\Driver\Base::factory($method, $config);
 
             // attach storage
             $driver->storage = $this->get_storage();
 
             if ($rcmail->user->ID) {
                 $driver->username  = $rcmail->get_user_name();
             }
 
             $this->drivers[$method] = $driver;
             return $driver;
         }
         catch (Exception $e) {
             $error = strval($e);
         }
 
         rcube::raise_error(array(
                 'code' => 600,
                 'type' => 'php',
                 'file' => __FILE__,
                 'line' => __LINE__,
                 'message' => $error),
             true, false);
 
         return false;
     }
 
     /**
      * Getter for a storage instance singleton
      */
     public function get_storage($for = null)
     {
         if (!isset($this->storage) || (!empty($for) && $this->storage->username !== $for)) {
             $rcmail = rcmail::get_instance();
             try {
                 $this->storage = \Kolab2FA\Storage\Base::factory(
                     $rcmail->config->get('kolab_2fa_storage', 'roundcube'),
                     $rcmail->config->get('kolab_2fa_storage_config', array())
                 );
 
                 $this->storage->set_username($for);
+                $this->storage->set_logger(new \Kolab2FA\Log\RcubeLogger());
 
                 // set user properties from active session
                 if (!empty($_SESSION['kolab_dn'])) {
                     $this->storage->userdn = $_SESSION['kolab_dn'];
                 }
             }
             catch (Exception $e) {
                 $this->storage = false;
 
                 rcube::raise_error(array(
                         'code' => 600,
                         'type' => 'php',
                         'file' => __FILE__,
                         'line' => __LINE__,
                         'message' => $error),
                     true, false);
             }
         }
 
         return $this->storage;
     }
 
     /**
      * Handler for 'settings_actions' hook
      */
     public function settings_actions($args)
     {
         // register as settings action
         $args['actions'][] = array(
             'action' => 'plugin.kolab-2fa',
             'class'  => '2factorauth',
             'label'  => 'settingslist',
             'title'  => 'settingstitle',
             'domain' => 'kolab_2fa',
         );
 
         return $args;
     }
 
     /**
      * Handler for settings/plugin.kolab-2fa requests
      */
     public function settings_view()
     {
         $this->register_handler('plugin.settingsform', array($this, 'settings_form'));
         $this->register_handler('plugin.settingslist', array($this, 'settings_list'));
         $this->register_handler('plugin.factoradder', array($this, 'settings_factoradder'));
         $this->register_handler('plugin.highsecuritydialog', array($this, 'settings_highsecuritydialog'));
 
         $this->include_script('kolab2fa.js');
         $this->include_stylesheet($this->local_skin_path() . '/kolab2fa.css');
 
         if ($this->check_secure_mode()) {
             $this->api->output->set_env('session_secured', $_SESSION['kolab_2fa_secure_mode']);
         }
 
         $this->api->output->add_label('save','cancel');
         $this->api->output->set_pagetitle($this->gettext('settingstitle'));
         $this->api->output->send('kolab_2fa.config');
     }
 
     /**
      * Render the menu to add another authentication factor
      */
     public function settings_factoradder($attrib)
     {
         $rcmail = rcmail::get_instance();
 
         $select = new html_select(array('id' => 'kolab2fa-add'));
         $select->add($this->gettext('addfactor') . '...', '');
         foreach ((array)$rcmail->config->get('kolab_2fa_drivers', array()) as $method) {
             $select->add($this->gettext($method), $method);
         }
 
         return $select->show();
     }
 
     /**
      * Render a list of active factor this user has configured
      */
     public function settings_list($attrib = array())
     {
         $attrib['id'] = 'kolab2fa-factors';
         $table = new html_table(array('cols' => 3));
 
         $table->add_header('name', $this->gettext('factor'));
         $table->add_header('created', $this->gettext('created'));
         $table->add_header('actions', '');
 
         return $table->show($attrib);
     }
 
     /**
      * Render the settings form template object
      */
     public function settings_form($attrib = array())
     {
         $rcmail = rcmail::get_instance();
         $storage = $this->get_storage($rcmail->get_user_name());
         $factors = $storage ? (array)$storage->enumerate() : array();
         $drivers = (array)$rcmail->config->get('kolab_2fa_drivers', array());
         $env_methods = array();
 
         foreach ($drivers as $j => $method) {
             $out .= $this->settings_factor($method, $attrib);
             $env_methods[$method] = array(
                 'name'   => $this->gettext($method),
                 'active' => 0,
             );
         }
 
         $me = $this;
         $this->api->output->set_env('kolab_2fa_factors', array_combine(
             $factors,
             array_map(function($id) use ($me, &$env_methods) {
                 $props = array('id' => $id);
 
                 if ($driver = $me->get_driver($id)) {
                     $props += $this->format_props($driver->props());
                     $props['method'] = $driver->method;
                     $props['name'] = $me->gettext($driver->method);
                     $env_methods[$driver->method]['active']++;
                 }
 
                 return $props;
             }, $factors)
         ));
 
         $this->api->output->set_env('kolab_2fa_methods', $env_methods);
 
         return html::div(array('id' => 'kolab2fapropform'), $out);
     }
 
     /**
      * Render the settings UI for the given method/driver
      */
     protected function settings_factor($method, $attrib)
     {
         $out = '';
         $rcmail = rcmail::get_instance();
         $attrib += array('class' => 'propform');
 
         if ($driver = $this->get_driver($method)) {
             $table = new html_table(array('cols' => 2, 'class' => $attrib['class']));
 
             foreach ($driver->props() as $field => $prop) {
                 if (!$prop['editable']) {
                     continue;
                 }
 
                 switch ($prop['type']) {
                     case 'boolean':
                     case 'checkbox':
                         $input = new html_checkbox(array('value' => '1'));
                         break;
 
                     case 'enum':
                     case 'select':
                         $input = new html_select(array('disabled' => $prop['readonly']));
                         $input->add(array_map(array($this, 'gettext'), $prop['options']), $prop['options']);
                         break;
 
                     default:
                         $input = new html_inputfield(array('size' => $prop['size'] ?: 30, 'disabled' => !$prop['editable']));
                 }
 
                 $explain_label = $field . 'explain' . $method;
                 $explain_html = $rcmail->text_exists($explain_label, 'kolab_2fa') ? html::p('explain', $this->gettext($explain_label)) : '';
 
                 $field_id = 'rcmk2fa' . $method . $field;
                 $table->add('title', html::label($field_id, $this->gettext($field)));
                 $table->add(null, $input->show('', array('id' => $field_id, 'name' => "_prop[$field]")) . $explain_html);
             }
 
             // add row for displaying the QR code
             if (method_exists($driver, 'get_provisioning_uri')) {
                 $table->add('title', $this->gettext('qrcode'));
                 $table->add(null,
                     html::p('explain',
                         $this->gettext("qrcodeexplain$method")
                     ) .
                     html::p(null,
                         html::tag('img', array('src' => 'data:image/gif;base64,R0lGODlhDwAPAIAAAMDAwAAAACH5BAEAAAAALAAAAAAPAA8AQAINhI+py+0Po5y02otnAQA7', 'class' => 'qrcode', 'rel' => $method))
                     )
                 );
 
                 // add row for testing the factor
                 $field_id = 'rcmk2faverify' . $method;
                 $table->add('title', html::label($field_id, $this->gettext('verifycode')));
                 $table->add(null,
                     html::tag('input', array('type' => 'text', 'name' => '_verify_code', 'id' => $field_id, 'class' => 'k2fa-verify', 'size' => 20, 'required' => true)) .
                     html::p('explain', $this->gettext("verifycodeexplain$method"))
                 );
 
             }
 
             $input_id = new html_hiddenfield(array('name' => '_prop[id]', 'value' => ''));
 
             $out .= html::tag('form', array(
                     'method' => 'post',
                     'action' => '#',
                     'id' => 'kolab2fa-prop-' . $method,
                     'style' => 'display:none',
                 ),
                 html::tag('fieldset', array(),
                     html::tag('legend', array(), $this->gettext($method)) .
                     html::div('factorprop', $table->show()) .
                     $input_id->show()
                 )
             );
         }
 
         return $out;
     }
     
     /**
      * Render th
      */
     public function settings_highsecuritydialog($attrib = array())
     {
         $attrib += array('id' => 'kolab2fa-highsecuritydialog');
 
         $field_id = 'rcmk2facode';
         $input = new html_inputfield(array('name' => '_code', 'id' => $field_id, 'class' => 'verifycode', 'size' => 20));
 
         return html::div($attrib,
             html::p('explain', $this->gettext('highsecuritydialog')) .
             html::div('propform', html::label($field_id, '$name') . $input->show(''))
         );
     }
 
     /**
      * Handler for settings/plugin.kolab-2fa-save requests
      */
     public function settings_save()
     {
         $method = rcube_utils::get_input_value('_method', rcube_utils::INPUT_POST);
         $data   = @json_decode(rcube_utils::get_input_value('_data', rcube_utils::INPUT_POST), true);
 
         $rcmail = rcmail::get_instance();
         $storage = $this->get_storage($rcmail->get_user_name());
         $success = false;
         $errors = 0;
         $save_data = array();
 
         if ($driver = $this->get_driver($method)) {
             if ($data === false) {
                 if ($this->check_secure_mode()) {
                     // remove method from active factors and clear stored settings
                     $success = $driver->clear();
                 }
                 else {
                     $errors++;
                 }
             }
             else {
                 // verify the submitted code before saving
                 $verify_code = rcube_utils::get_input_value('_verify_code', rcube_utils::INPUT_POST);
                 $timestamp = intval(rcube_utils::get_input_value('_timestamp', rcube_utils::INPUT_POST));
                 if (!empty($verify_code)) {
                     if (!$driver->verify($verify_code, $timestamp)) {
                         $this->api->output->command('plugin.verify_response', array(
                             'id'      => $driver->id,
                             'method'  => $driver->method,
                             'success' => false,
                             'message' => str_replace('$method', $this->gettext($driver->method), $this->gettext('codeverificationfailed'))
                         ));
                         $this->api->output->send();
                     }
                 }
 
                 foreach ($data as $prop => $value) {
                     if (!$driver->set($prop, $value)) {
                         $errors++;
                     }
                 }
 
                 $driver->set('active', true);
             }
 
             // commit changes to the user properties
             if (!$errors) {
                 if ($success = $driver->commit()) {
                     $save_data = $data !== false ? $this->format_props($driver->props()) : array();
                 }
                 else {
                     $errors++;
                 }
             }
         }
 
         if ($success) {
             $this->api->output->show_message($data === false ? $this->gettext('factorremovesuccess') : $this->gettext('factorsavesuccess'), 'confirmation');
             $this->api->output->command('plugin.save_success', array('method' => $method, 'active' => $data !== false) + $save_data);
         }
         else if ($errors) {
             $this->api->output->show_message($this->gettext('factorsaveerror'), 'error');
             $this->api->output->command('plugin.reset_form', $method);
         }
 
         $this->api->output->send();
     }
 
     /**
      * Handler for settings/plugin.kolab-2fa-data requests
      */
     public function settings_data()
     {
         $method = rcube_utils::get_input_value('_method', rcube_utils::INPUT_POST);
 
         if ($driver = $this->get_driver($method)) {
             $data = array('method' => $method, 'id' => $driver->id);
 
             foreach ($driver->props(true) as $field => $prop) {
                 $data[$field] = $prop['text'] ?: $prop['value'];
             }
 
             // generate QR code for provisioning URI
             if (method_exists($driver, 'get_provisioning_uri')) {
                 try {
                     $uri = $driver->get_provisioning_uri();
 
                     $qr = new Endroid\QrCode\QrCode();
                     $qr->setText($uri)
                        ->setSize(240)
                        ->setPadding(10)
                        ->setErrorCorrection('high')
                        ->setForegroundColor(array('r' => 0, 'g' => 0, 'b' => 0, 'a' => 0))
                        ->setBackgroundColor(array('r' => 255, 'g' => 255, 'b' => 255, 'a' => 0));
                     $data['qrcode'] = base64_encode($qr->get());
                 }
                 catch (Exception $e) {
                     rcube::raise_error($e, true, false);
                 }
             }
 
             $this->api->output->command('plugin.render_data', $data);
         }
 
         $this->api->output->send();
     }
 
     /**
      * Handler for settings/plugin.kolab-2fa-verify requests
      */
     public function settings_verify()
     {
         $method = rcube_utils::get_input_value('_method', rcube_utils::INPUT_POST);
         $timestamp = intval(rcube_utils::get_input_value('_timestamp', rcube_utils::INPUT_POST));
         $success = false;
 
         if ($driver = $this->get_driver($method)) {
             $data = @json_decode(rcube_utils::get_input_value('_data', rcube_utils::INPUT_POST), true);
             if (is_array($data)) {
                 foreach ($data as $key => $value) {
                     if ($value !== '******') {
                         $driver->$key = $value;
                     }
                 }
             }
             $success = $driver->verify(rcube_utils::get_input_value('_code', rcube_utils::INPUT_POST), $timestamp);
             $method = $driver->method;
         }
 
         // put session into high-security mode
         if ($success && !empty($_POST['_session'])) {
             $_SESSION['kolab_2fa_secure_mode'] = time();
         }
 
         $this->api->output->command('plugin.verify_response', array(
             'method' => $method,
             'success' => $success,
             'message' => str_replace('$method', $this->gettext($method),
                 $this->gettext($success ? 'codeverificationpassed' : 'codeverificationfailed'))
         ));
         $this->api->output->send();
     }
 
     /**
      *
      */
     protected function format_props($props)
     {
         $rcmail = rcmail::get_instance();
         $values = array();
 
         foreach ($props as $key => $prop) {
             switch ($prop['type']) {
                 case 'datetime':
                     $value = $rcmail->format_date($prop['value']);
                     break;
 
                 default:
                     $value = $prop['value'];
             }
 
             $values[$key] = $value;
         }
 
         return $values;
     }
 
     /**
      *
      */
     protected function check_secure_mode()
     {
         $valid = ($_SESSION['kolab_2fa_secure_mode'] && $_SESSION['kolab_2fa_secure_mode'] > time() - 180);
         return $valid;
     }
 
 }
\ No newline at end of file
diff --git a/plugins/kolab_2fa/lib/Kolab2FA/Storage/Base.php b/plugins/kolab_2fa/lib/Kolab2FA/Storage/Base.php
index f79f2d57..b4f36115 100644
--- a/plugins/kolab_2fa/lib/Kolab2FA/Storage/Base.php
+++ b/plugins/kolab_2fa/lib/Kolab2FA/Storage/Base.php
@@ -1,95 +1,127 @@
 <?php
 
 /**
  * Abstract storage backend class for the Kolab 2-Factor-Authentication plugin
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2015, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 namespace Kolab2FA\Storage;
 
+use \Kolab2FA\Log;
+
+
 abstract class Base
 {
     public $username = null;
     protected $config = array();
+    protected $logger;
 
     /**
      *
      */
     public static function factory($backend, $config)
     {
         $classmap = array(
             'ldap' => '\\Kolab2FA\\Storage\\LDAP',
             'roundcube' => '\\Kolab2FA\\Storage\\RcubeUser',
             'rcubeuser' => '\\Kolab2FA\\Storage\\RcubeUser',
         );
 
         $cls = $classmap[strtolower($backend)];
         if ($cls && class_exists($cls)) {
             return new $cls($config);
         }
 
         throw new Exception("Unknown storage backend '$backend'");
     }
 
     /**
      * Default constructor
      */
     public function __construct($config = null)
     {
         if (is_array($config)) {
             $this->init($config);
         }
     }
 
     /**
      * Initialize the driver with the given config options
      */
     public function init(array $config)
     {
         $this->config = array_merge($this->config, $config);
+
+        // use syslog logger by default
+        $this->set_logger(new Log\Syslog());
+    }
+
+    /**
+     * 
+     */
+    public function set_logger(Log\Logger $logger)
+    {
+        $this->logger = $logger;
+
+        if ($this->config['debug']) {
+            $this->logger->set_level(LOG_DEBUG);
+        }
+        else if ($this->config['loglevel']) {
+            $this->logger->set_level($this->config['loglevel']);
+        }
     }
 
     /**
      * Set username to store data for
      */
     public function set_username($username)
     {
         $this->username = $username;
     }
 
+    /**
+     * Send messager to the logging system
+     */
+    protected function log($level, $message)
+    {
+        if ($this->logger) {
+            $this->logger->log($level, $message);
+        }
+    }
+
     /**
      * List keys holding settings for 2-factor-authentication
      */
     abstract public function enumerate();
 
     /**
      * Read data for the given key
      */
     abstract public function read($key);
 
     /**
      * Save data for the given key
      */
     abstract public function write($key, $value);
 
     /**
      * Remove the data stored for the given key
      */
     abstract public function remove($key);
 }
diff --git a/plugins/kolab_2fa/lib/Kolab2FA/Storage/LDAP.php b/plugins/kolab_2fa/lib/Kolab2FA/Storage/LDAP.php
index 67871adf..074c2cbd 100644
--- a/plugins/kolab_2fa/lib/Kolab2FA/Storage/LDAP.php
+++ b/plugins/kolab_2fa/lib/Kolab2FA/Storage/LDAP.php
@@ -1,374 +1,349 @@
 <?php
 
 /**
  * Storage backend to store 2-Factor-Authentication settings in LDAP
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2015, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 namespace Kolab2FA\Storage;
 
 use \Net_LDAP3;
+use \Kolab2FA\Log\Logger;
 
 class LDAP extends Base
 {
     public $userdn;
 
     private $cache = array();
     private $ldapcache = array();
     private $conn;
     private $error;
 
     public function init(array $config)
     {
         parent::init($config);
 
         $this->conn = new Net_LDAP3($config);
         $this->conn->config_set('log_hook', array($this, 'log'));
 
         $this->conn->connect();
 
         $bind_pass = $this->config['bind_pass'];
         $bind_user = $this->config['bind_user'];
         $bind_dn   = $this->config['bind_dn'];
 
         $this->ready = $this->conn->bind($bind_dn, $bind_pass);
 
         if (!$this->ready) {
             throw new Exception("LDAP storage not ready: " . $this->error);
         }
     }
 
     /**
      * List/set methods activated for this user
      */
     public function enumerate($active = true)
     {
         $filter  = $this->parse_vars($this->config['filter'],  '*');
         $base_dn = $this->parse_vars($this->config['base_dn'], '*');
         $scope   = $this->config['scope'] ?: 'sub';
         $ids     = array();
 
         if ($this->ready && ($result = $this->conn->search($base_dn, $filter, $scope, array($this->config['fieldmap']['id'], $this->config['fieldmap']['active'])))) {
             foreach ($result as $dn => $entry) {
                 $rec = $this->field_mapping($dn, Net_LDAP3::normalize_entry($entry, true));
                 if (!empty($rec['id']) && ($active === null || $active == $rec['active'])) {
                     $ids[] = $rec['id'];
                 }
             }
         }
 
         // TODO: cache this in memory
 
         return $ids;
     }
 
     /**
      * Read data for the given key
      */
     public function read($key)
     {
         if (!isset($this->cache[$key])) {
             $this->cache[$key] = $this->get_ldap_record($this->username, $key);
         }
 
         return $this->cache[$key];
     }
 
     /**
      * Save data for the given key
      */
     public function write($key, $value)
     {
         $success = false;
         $ldap_attrs = array();
 
         if (is_array($value)) {
             // add some default values
             $value += (array)$this->config['defaults'] + array('active' => false, 'username' => $this->username, 'userdn' => $this->userdn);
 
             foreach ($value as $k => $val) {
                 if ($attr = $this->config['fieldmap'][$k]) {
                     $ldap_attrs[$attr] = $this->value_mapping($k, $val, false);
                 }
             }
         }
         else {
             // invalid data structure
             return false;
         }
 
         // update existing record
         if ($rec = $this->get_ldap_record($this->username, $key)) {
             $old_attrs = $rec['_raw'];
             $new_attrs = array_merge($old_attrs, $ldap_attrs);
 
             $result = $this->conn->modify_entry($rec['_dn'], $old_attrs, $new_attrs);
             $success = !empty($result);
         }
         // insert new record
         else if ($this->ready) {
             $entry_dn = $this->get_entry_dn($this->username, $key);
 
             // add object class attribute
             $me = $this;
             $ldap_attrs['objectclass'] = array_map(function($cls) use ($me, $key) {
                 return $me->parse_vars($cls, $key);
             }, (array)$this->config['objectclass']);
 
             $success = $this->conn->add_entry($entry_dn, $ldap_attrs);
         }
 
         if ($success) {
             $this->cache[$key] = $value;
             $this->ldapcache = array();
 
             // cleanup: remove disabled/inactive/temporary entries
             if ($value['active']) {
                 foreach ($this->enumerate(false) as $id) {
                     if ($id != $key) {
                         $this->remove($id);
                     }
                 }
 
                 // set user roles according to active factors
                 $this->set_user_roles();
             }
         }
 
         return $success;
     }
 
     /**
      * Remove the data stored for the given key
      */
     public function remove($key)
     {
         if ($this->ready) {
             $entry_dn = $this->get_entry_dn($this->username, $key);
             $success = $this->conn->delete_entry($entry_dn);
 
             // set user roles according to active factors
             if ($success) {
                 $this->set_user_roles();
             }
 
             return $success;
         }
 
         return false;
     }
 
     /**
      * Set username to store data for
      */
     public function set_username($username)
     {
         parent::set_username($username);
 
         // reset cached values
         $this->cache = array();
         $this->ldapcache = array();
     }
 
     /**
      *
      */
     protected function set_user_roles()
     {
         if (!$this->ready || !$this->userdn || empty($this->config['user_roles'])) {
             return false;
         }
 
         $auth_roles = array();
         foreach ($this->enumerate(true) as $id) {
             foreach ($this->config['user_roles'] as $prefix => $role) {
                 if (strpos($id, $prefix) === 0) {
                     $auth_roles[] = $role;
                 }
             }
         }
 
         $role_attr = $this->config['fieldmap']['roles'] ?: 'nsroledn';
         if ($user_attrs = $this->conn->get_entry($this->userdn, array($role_attr))) {
             $internals = array_values($this->config['user_roles']);
             $new_attrs = $old_attrs = Net_LDAP3::normalize_entry($user_attrs);
             $new_attrs[$role_attr] = array_merge(
                 array_unique($auth_roles),
                 array_filter((array)$old_attrs[$role_attr], function($f) use ($internals) { return !in_array($f, $internals); })
             );
 
             $result = $this->conn->modify_entry($this->userdn, $old_attrs, $new_attrs);
             return !empty($result);
         }
 
         return false;
     }
 
     /**
      * Fetches user data from LDAP addressbook
      */
     protected function get_ldap_record($user, $key)
     {
         $entry_dn = $this->get_entry_dn($user, $key);
 
         if (!isset($this->ldapcache[$entry_dn])) {
             $this->ldapcache[$entry_dn] = array();
 
             if ($this->ready && ($entry = $this->conn->get_entry($entry_dn, array_values($this->config['fieldmap'])))) {
                 $this->ldapcache[$entry_dn] = $this->field_mapping($entry_dn, Net_LDAP3::normalize_entry($entry, true));
             }
         }
 
         return $this->ldapcache[$entry_dn];
     }
 
     /**
      * Compose a full DN for the given record identifier
      */
     protected function get_entry_dn($user, $key)
     {
         $base_dn = $this->parse_vars($this->config['base_dn'], $key);
         return sprintf('%s=%s,%s', $this->config['rdn'], Net_LDAP3::quote_string($key, true), $base_dn);
     }
 
     /**
      * Maps LDAP attributes to defined fields
      */
     protected function field_mapping($dn, $entry)
     {
         $entry['_dn'] = $dn;
         $entry['_raw'] = $entry;
 
         // fields mapping
         foreach ($this->config['fieldmap'] as $field => $attr) {
             $attr_lc = strtolower($attr);
             if (isset($entry[$attr_lc])) {
                 $entry[$field] = $this->value_mapping($field, $entry[$attr_lc], true);
             }
             else if (isset($entry[$attr])) {
                 $entry[$field] = $this->value_mapping($field, $entry[$attr], true);
             }
         }
 
         return $entry;
     }
 
     /**
      *
      */
     protected function value_mapping($attr, $value, $reverse = false)
     {
         if ($map = $this->config['valuemap'][$attr]) {
             if ($reverse) {
                 $map = array_flip($map);
             }
 
             if (is_array($value)) {
                 $value = array_filter(array_map(function($val) use ($map) {
                     return $map[$val];
                 }, $value));
             }
             else {
                 $value = $map[$value];
             }
         }
 
         // convert (date) type
         switch ($this->config['attrtypes'][$attr]) {
             case 'datetime':
                 $ts = is_numeric($value) ? $value : strtotime($value);
                 if ($ts) {
                     $value = gmdate($reverse ? 'U' : 'YmdHi\Z', $ts);
                 }
                 break;
 
             case 'integer':
                 $value = intval($value);
                 break;
         }
 
         return $value;
     }
 
     /**
      * Prepares filter query for LDAP search
      */
     protected function parse_vars($str, $key)
     {
         $user = $this->username;
 
         if (strpos($user, '@') > 0) {
             list($u, $d) = explode('@', $user);
         }
         else if ($this->userdn) {
             $u = $this->userdn;
             $d = trim(str_replace(',dc=', '.', substr($u, strpos($u, ',dc='))), '.');
         }
 
         if ($this->userdn) {
             $user = $this->userdn;
         }
 
         // build hierarchal domain string
         $dc = $this->conn->domain_root_dn($d);
 
         $class = $this->config['classmap'] ? $this->config['classmap']['*'] : '*';
 
         // map key to objectclass
         if (is_array($this->config['classmap'])) {
             foreach ($this->config['classmap'] as $k => $c) {
                 if (strpos($key, $k) === 0) {
                     $class = $c;
                     break;
                 }
             }
         }
 
         $replaces = array('%dc' => $dc, '%d' => $d, '%fu' => $user, '%u' => $u, '%c' => $class);
 
         return strtr($str, $replaces);
     }
 
-    /**
-     * Prints debug/error info to the log
-     */
-    public function log($level, $msg)
-    {
-        $msg = implode("\n", $msg);
-
-        switch ($level) {
-        case LOG_DEBUG:
-        case LOG_INFO:
-        case LOG_NOTICE:
-            if ($this->config['debug'] && class_exists('\\rcube', false)) {
-                \rcube::write_log('ldap', $msg);
-            }
-            break;
-
-        case LOG_EMERGE:
-        case LOG_ALERT:
-        case LOG_CRIT:
-        case LOG_ERR:
-        case LOG_WARNING:
-            $this->error = $msg;
-            // throw new Exception("LDAP storage error: " . $msg);
-            break;
-        }
-    }
 }
diff --git a/plugins/kolab_2fa/lib/Kolab2FA/Storage/RcubeUser.php b/plugins/kolab_2fa/lib/Kolab2FA/Storage/RcubeUser.php
index 5f614704..99f89cd6 100644
--- a/plugins/kolab_2fa/lib/Kolab2FA/Storage/RcubeUser.php
+++ b/plugins/kolab_2fa/lib/Kolab2FA/Storage/RcubeUser.php
@@ -1,183 +1,193 @@
 <?php
 
 /**
  * Storage backend to use the Roundcube user prefs to store 2-Factor-Authentication settings
  *
  * @author Thomas Bruederli <bruederli@kolabsys.com>
  *
  * Copyright (C) 2015, Kolab Systems AG <contact@kolabsys.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
  * published by the Free Software Foundation, either version 3 of the
  * License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU Affero General Public License for more details.
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
 namespace Kolab2FA\Storage;
 
 use \rcmail;
 use \rcube_user;
 
 class RcubeUser extends Base
 {
     // sefault config
     protected $config = array(
         'keymap' => array(),
     );
 
     private $cache = array();
     private $user;
 
     public function init(array $config)
     {
         parent::init($config);
 
         $rcmail = rcmail::get_instance();
         $this->config['hostname'] = $rcmail->user->ID ? $rcmail->user->data['mail_host'] : $_SESSION['hostname'];
     }
 
     /**
      * List/set methods activated for this user
      */
     public function enumerate()
     {
         if ($factors = $this->get_factors()) {
             return array_keys(array_filter($factors, function($prop) {
                 return !empty($prop['active']);
             }));
         }
 
         return array();
     }
 
     /**
      * Read data for the given key
      */
     public function read($key)
     {
         if (!isset($this->cache[$key])) {
             $factors = $this->get_factors();
-            console('READ', $key, $factors);
+            $this->log(LOG_DEBUG, 'RcubeUser::read() ' . $key);
             $this->cache[$key] = $factors[$key];
         }
 
         return $this->cache[$key];
     }
 
     /**
      * Save data for the given key
      */
     public function write($key, $value)
     {
+        $this->log(LOG_DEBUG, 'RcubeUser::write() ' . @json_encode($value));
+
         if ($user = $this->get_user($this->username)) {
             $this->cache[$key] = $value;
 
             $factors = $this->get_factors();
             $factors[$key] = $value;
 
             $pkey = $this->key2property('blob');
             $save_data = array($pkey => $factors);
             $update_index = false;
 
             // remove entry
             if ($value === null) {
                 unset($factors[$key]);
                 $update_index = true;
             }
             // remove non-active entries
             else if (!empty($value['active'])) {
                 $factors = array_filter($factors, function($prop) {
                     return !empty($prop['active']);
                 });
                 $update_index = true;
             }
 
             // update the index of active factors
             if ($update_index) {
                 $save_data[$this->key2property('factors')] = array_keys(
                     array_filter($factors, function($prop) {
                         return !empty($prop['active']);
                     })
                 );
             }
 
-            return $user->save_prefs($save_data, true);
+            $success = $user->save_prefs($save_data, true);
+
+            if (!$success) {
+                $this->log(LOG_WARNING, sprintf('Failed to save prefs for user %s', $this->username));
+            }
         }
 
         return false;
     }
 
     /**
      * Remove the data stored for the given key
      */
     public function remove($key)
     {
         return $this->write($key, null);
     }
 
     /**
      * Set username to store data for
      */
     public function set_username($username)
     {
         parent::set_username($username);
 
         // reset cached values
         $this->cache = array();
         $this->user = null;
     }
 
     /**
      * Helper method to get a rcube_user instance for storing prefs
      */
     private function get_user($username)
     {
         // use global instance if we have a valid Roundcube session
         $rcmail = rcmail::get_instance();
         if ($rcmail->user->ID && $rcmail->user->get_username() == $username) {
             return $rcmail->user;
         }
 
         if (!$this->user) {
             $this->user = rcube_user::query($username, $this->config['hostname']);
         }
 
+        if (!$this->user) {
+            $this->log(LOG_WARNING, sprintf('No user record found for %s @ %s', $username, $this->config['hostname']));
+        }
+
         return $this->user;
     }
 
     /**
      *
      */
     private function get_factors()
     {
         if ($user = $this->get_user($this->username)) {
             $prefs = $user->get_prefs();
             return (array)$prefs[$this->key2property('blob')];
         }
 
         return null;
     }
 
     /**
      *
      */
     private function key2property($key)
     {
         // map key to configured property name
         if (is_array($this->config['keymap']) && isset($this->config['keymap'][$key])) {
             return $this->config['keymap'][$key];
         }
 
         // default
         return 'kolab_2fa_' . $key;
     }
 
 }