squirrelmail/include/init.php

<?php

/**
 * init.php -- initialisation file
 *
 * File should be loaded in every file in src/ or plugins that occupate an entire frame
 *
 * @copyright &copy; 2006 The SquirrelMail Project Team
 * @license http://opensource.org/licenses/gpl-license.php GNU Public License
 * @version $Id$
 * @package squirrelmail
 */

/**
 * This is a development version so in order to track programmer mistakes we
 * set the error reporting to E_ALL
FIXME: disabling this for now, because we now have $sm_debug_mode, but the problem with that is that we don't know what it will be until we have loaded the config file, a good 175 lines below after several important files have been included, etc.  For now, we'll trust that developers have turned on E_ALL in php.ini anyway, but this can be uncommented if not.
 */
//error_reporting(E_ALL);



/**
 * Make sure we have a page name
 *
 */
if ( !defined('PAGE_NAME') ) define('PAGE_NAME', NULL);


/**
 * If register_globals are on, unregister globals.
 * Second test covers boolean set as string (php_value register_globals off).
 */
if ((bool) ini_get('register_globals') &&
    strtolower(ini_get('register_globals'))!='off') {
    /**
     * Remove all globals that are not reserved by PHP
     * 'value' and 'key' are used by foreach. Don't unset them inside foreach.
     */
    foreach ($GLOBALS as $key => $value) {
        switch($key) {
        case 'HTTP_POST_VARS':
        case '_POST':
        case 'HTTP_GET_VARS':
        case '_GET':
        case 'HTTP_COOKIE_VARS':
        case '_COOKIE':
        case 'HTTP_SERVER_VARS':
        case '_SERVER':
        case 'HTTP_ENV_VARS':
        case '_ENV':
        case 'HTTP_POST_FILES':
        case '_FILES':
        case '_REQUEST':
        case 'HTTP_SESSION_VARS':
        case '_SESSION':
        case 'GLOBALS':
        case 'key':
        case 'value':
            break;
        default:
            unset($GLOBALS[$key]);
        }
    }
    // Unset variables used in foreach
    unset($GLOBALS['key']);
    unset($GLOBALS['value']);
}

/**
 * Used as a dummy value, e.g., for passing as an empty
 * hook argument (where the value is passed by reference,
 * and therefore NULL itself is not acceptable).
 */
global $null;
$null = NULL;

/**
 * [#1518885] session.use_cookies = off breaks SquirrelMail
 *
 * When session cookies are not used, all http redirects, meta refreshes,
 * src/download.php and javascript URLs are broken. Setting must be set
 * before session is started.
 */
if (!(bool)ini_get('session.use_cookies') ||
    ini_get('session.use_cookies') == 'off') {
    ini_set('session.use_cookies','1');
}


/**
 * calculate SM_PATH and calculate the base_uri
 * assumptions made: init.php is only called from plugins or from the src dir.
 * files in the plugin directory may not be part of a subdirectory called "src"
 *
 */
if (isset($_SERVER['SCRIPT_NAME'])) {
    $a = explode('/', $_SERVER['SCRIPT_NAME']);
} elseif (isset($HTTP_SERVER_VARS['SCRIPT_NAME'])) {
    $a = explode('/', $HTTP_SERVER_VARS['SCRIPT_NAME']);
} else {
    $error = 'Unable to detect script environment. Please test your PHP '
           . 'settings and send your PHP core configuration, $_SERVER and '
           . '$HTTP_SERVER_VARS contents to the SquirrelMail developers.';
    die($error);
}
$sSM_PATH = '';
for($i = count($a) -2; $i > -1; --$i) {
    $sSM_PATH .= '../';
    if ($a[$i] === 'src' || $a[$i] === 'plugins') {
        break;
    }
}

$base_uri = implode('/', array_slice($a, 0, $i)). '/';

define('SM_PATH',$sSM_PATH);
define('SM_BASE_URI', $base_uri);


/**
 * global var $bInit is used to check if initialisation took place.
 * At this moment it's a workarounf for the include of addrbook_search_html
 * inside compose.php. If we found a better way then remove this. Do only use
 * this var if you know for sure a page can be called stand alone and be included
 * in another file.
 */
$bInit = true;

/**
 * This theme as a failsafe if no themes were found, or if we error
 * out before anything could be initialised.
 */
$color = array();
$color[0]  = '#DCDCDC';  /* light gray    TitleBar               */
$color[1]  = '#800000';  /* red                                  */
$color[2]  = '#CC0000';  /* light red     Warning/Error Messages */
$color[3]  = '#A0B8C8';  /* green-blue    Left Bar Background    */
$color[4]  = '#FFFFFF';  /* white         Normal Background      */
$color[5]  = '#FFFFCC';  /* light yellow  Table Headers          */
$color[6]  = '#000000';  /* black         Text on left bar       */
$color[7]  = '#0000CC';  /* blue          Links                  */
$color[8]  = '#000000';  /* black         Normal text            */
$color[9]  = '#ABABAB';  /* mid-gray      Darker version of #0   */
$color[10] = '#666666';  /* dark gray     Darker version of #9   */
$color[11] = '#770000';  /* dark red      Special Folders color  */
$color[12] = '#EDEDED';
$color[13] = '#800000';  /* (dark red)    Color for quoted text -- > 1 quote */
$color[14] = '#ff0000';  /* (red)         Color for quoted text -- >> 2 or more */
$color[15] = '#002266';  /* (dark blue)   Unselectable folders */
$color[16] = '#ff9933';  /* (orange)      Highlight color */

require(SM_PATH . 'include/constants.php');
require(SM_PATH . 'functions/global.php');
require(SM_PATH . 'functions/strings.php');
require(SM_PATH . 'functions/arrays.php');

/* load default configuration */
require(SM_PATH . 'config/config_default.php');
/* reset arrays in default configuration */
$ldap_server = array();
$plugins = array();
$fontsets = array();
$aTemplateSet = array();
$aTemplateSet[0]['ID'] = 'default';
$aTemplateSet[0]['NAME'] = 'Default';

/* load site configuration */
require(SM_PATH . 'config/config.php');
/* load local configuration overrides */
if (file_exists(SM_PATH . 'config/config_local.php')) {
    require(SM_PATH . 'config/config_local.php');
}


/**
 * Set PHP error reporting level based on the SquirrelMail debug mode
 */
$error_level = 0;
if ($sm_debug_mode & SM_DEBUG_MODE_SIMPLE)
    $error_level |= E_ERROR;
if ($sm_debug_mode & SM_DEBUG_MODE_MODERATE
 || $sm_debug_mode & SM_DEBUG_MODE_ADVANCED)
    $error_level |= E_ALL;
if ($sm_debug_mode & SM_DEBUG_MODE_STRICT)
    $error_level |= E_STRICT;
error_reporting($error_level);


require(SM_PATH . 'functions/plugin.php');
require(SM_PATH . 'include/languages.php');
require(SM_PATH . 'class/template/Template.class.php');
require(SM_PATH . 'class/error.class.php');

/**
 * If magic_quotes_runtime is on, SquirrelMail breaks in new and creative ways.
 * Force magic_quotes_runtime off.
 * tassium@squirrelmail.org - I put it here in the hopes that all SM code includes this.
 * If there's a better place, please let me know.
 */
ini_set('magic_quotes_runtime','0');


/* if running with magic_quotes_gpc then strip the slashes
   from POST and GET global arrays */
if (function_exists('get_magic_quotes_gpc') && @get_magic_quotes_gpc()) {
    sqstripslashes($_GET);
    sqstripslashes($_POST);
}


/* strip any tags added to the url from PHP_SELF.
This fixes hand crafted url XXS expoits for any
   page that uses PHP_SELF as the FORM action */
$_SERVER['PHP_SELF'] = strip_tags($_SERVER['PHP_SELF']);

$PHP_SELF = php_self();

/**
 * Initialize the session
 */

/** set the name of the session cookie */
if (!isset($session_name) || !$session_name) {
    $session_name = 'SQMSESSID';
}

/**
 * When session.auto_start is On we want to destroy/close the session
 */
$sSessionAutostartName = session_name();
$sCookiePath = null;
if (isset($sSessionAutostartName) && $sSessionAutostartName !== $session_name) {
    $sCookiePath = ini_get('session.cookie_path');
    $sCookieDomain = ini_get('session.cookie_domain');
    // reset the cookie
    setcookie($sSessionAutostartName,'',time() - 604800,$sCookiePath,$sCookieDomain);
    @session_destroy();
    session_write_close();
}

/**
 * includes from classes stored in the session
 */
require(SM_PATH . 'class/mime.class.php');

ini_set('session.name' , $session_name);
session_set_cookie_params (0, $base_uri);
sqsession_is_active();

/**
 * When on login page, have to reset the user session, making
 * sure to save session restore data first
 */
if (PAGE_NAME == 'login') {
    if (!sqGetGlobalVar('session_expired_post', $sep, SQ_SESSION))
        $sep = '';
    if (!sqGetGlobalVar('session_expired_location', $sel, SQ_SESSION))
        $sel = '';
    sqsession_destroy();
    session_write_close();

    /**
     * in some rare instances, the session seems to stick
     * around even after destroying it (!!), so if it does,
     * we'll manually flatten the $_SESSION data
     */
    if (!empty($_SESSION))
        $_SESSION = array();

    /**
     * Allow administrators to define custom session handlers
     * for SquirrelMail without needing to change anything in
     * php.ini (application-level).
     *
     * In config_local.php, admin needs to put:
     *
     *     $custom_session_handlers = array(
     *         'my_open_handler',
     *         'my_close_handler',
     *         'my_read_handler',
     *         'my_write_handler',
     *         'my_destroy_handler',
     *         'my_gc_handler',
     *     );
     *     session_module_name('user');
     *     session_set_save_handler(
     *         $custom_session_handlers[0],
     *         $custom_session_handlers[1],
     *         $custom_session_handlers[2],
     *         $custom_session_handlers[3],
     *         $custom_session_handlers[4],
     *         $custom_session_handlers[5]
     *     );
     *
     * We need to replicate that code once here because PHP has
     * long had a bug that resets the session handler mechanism
     * when the session data is also destroyed.  Because of this
     * bug, even administrators who define custom session handlers
     * via a PHP pre-load defined in php.ini (auto_prepend_file)
     * will still need to define the $custom_session_handlers array
     * in config_local.php.
     */
    global $custom_session_handlers;
    if (!empty($custom_session_handlers)) {
        $open    = $custom_session_handlers[0];
        $close   = $custom_session_handlers[1];
        $read    = $custom_session_handlers[2];
        $write   = $custom_session_handlers[3];
        $destroy = $custom_session_handlers[4];
        $gc      = $custom_session_handlers[5];
        session_module_name('user');
        session_set_save_handler($open, $close, $read, $write, $destroy, $gc);
    }

    sqsession_is_active();
    session_regenerate_id();

    // put session restore data back into session if necessary
    if (!empty($sel)) {
        sqsession_register($sel, 'session_expired_location');
        if (!empty($sep))
            sqsession_register($sep, 'session_expired_post');
    }
}

/**
 * SquirrelMail internal version number -- DO NOT CHANGE
 * $sm_internal_version = array (release, major, minor)
 */
$SQM_INTERNAL_VERSION = explode('.', SM_VERSION, 3);
$SQM_INTERNAL_VERSION[2] = intval($SQM_INTERNAL_VERSION[2]);


/* load prefs system; even when user not logged in, should be OK to do this here */
require(SM_PATH . 'functions/prefs.php');

// FIXME: config/plugin_hooks.php has not yet been loaded (see a few lines below); so this hook call should I think not be working -- has anyone actually tested it?  Is there any reason we cannot move this prefs code block down below "MAIN PLUGIN LOADING CODE HERE" (see below)?  Reading the code, I *think* it should be OK, but....   Also, note that this code would then be placed immediately next to the config_override hook, and since it makes little sense to execute two hooks in a row, I will propose removing config_override (although sadly, it is less clear to plugin authors that they should use the prefs_backend hook to do any configuration override work in their plugin)
$prefs_backend = do_hook('prefs_backend', $null);
if (isset($prefs_backend) && !empty($prefs_backend) && file_exists(SM_PATH . $prefs_backend)) {
    require(SM_PATH . $prefs_backend);
} elseif (isset($prefs_dsn) && !empty($prefs_dsn)) {
    require(SM_PATH . 'functions/db_prefs.php');
} else {
    require(SM_PATH . 'functions/file_prefs.php');
}


/* if plugins are disabled only for one user and
 * the current user is NOT that user, turn them
 * back on
 */
sqgetGlobalVar('username',$username,SQ_SESSION);
if ($disable_plugins && !empty($disable_plugins_user)
 && $username != $disable_plugins_user) {
    $disable_plugins = false;
}

/* remove all plugins if they are disabled */
if ($disable_plugins) {
   $plugins = array();
}


/**
 * Include Compatibility plugin if available.
 */
if (!$disable_plugins && file_exists(SM_PATH . 'plugins/compatibility/functions.php'))
    include_once(SM_PATH . 'plugins/compatibility/functions.php');

/**
 * MAIN PLUGIN LOADING CODE HERE
 * On init, we no longer need to load all plugin setup files.
 * Now, we load the statically generated hook registrations here
 * and let the hook calls include only the plugins needed.
 */
$squirrelmail_plugin_hooks = array();
if (!$disable_plugins && file_exists(SM_PATH . 'config/plugin_hooks.php')) {
    require(SM_PATH . 'config/plugin_hooks.php');
}

/**
 * allow plugins to override main configuration; hook is placed
 * here to allow plugins to use session information to do their work
 */
do_hook('config_override', $null);

/**
 * DISABLED.
 * Remove globalized session data in rg=on setups
 *
 * Code can be utilized when session is started, but data is not loaded.
 * We have already loaded configuration and other important vars. Can't
 * clean session globals here, beside, the cleanout of globals at the
 * top of this file will have removed anything this code would find anyway.
if ((bool) @ini_get('register_globals') &&
    strtolower(ini_get('register_globals'))!='off') {
    foreach ($_SESSION as $key => $value) {
        unset($GLOBALS[$key]);
    }
}
*/

sqsession_register(SM_BASE_URI,'base_uri');

/**
 * Retrieve the language cookie
 */
if (! sqgetGlobalVar('squirrelmail_language',$squirrelmail_language,SQ_COOKIE)) {
    $squirrelmail_language = '';
}


/**
 * Do something special for some pages. This is based on the PAGE_NAME constant
 * set at the top of every page.
 */
switch (PAGE_NAME) {
    case 'style':

        // need to get the right template set up
        //
        sqGetGlobalVar('templateid', $templateid, SQ_GET);

        // sanitize just in case...
        //
        $templateid = preg_replace('/(\.\.\/){1,}/', '', $templateid);

        // make sure given template actually is available
        //
        $found_templateset = false;
        for ($i = 0; $i < count($aTemplateSet); ++$i) {
            if ($aTemplateSet[$i]['ID'] == $templateid) {
                $found_templateset = true;
                break;
            }
        }

// FIXME: do we need/want to check here for actual (physical) presence of template sets?
        // selected template not available, fall back to default template
        //
        if (!$found_templateset) {
            $sTemplateID = Template::get_default_template_set();
        } else {
            $sTemplateID = $templateid;
        }

        session_write_close();
        break;

    case 'mailto':
        // nothing to do
        break;

    case 'redirect':
        require(SM_PATH . 'functions/auth.php');
        //nobreak;

    case 'login':
        require(SM_PATH . 'functions/display_messages.php' );
        require(SM_PATH . 'functions/page_header.php');
        require(SM_PATH . 'functions/html.php');

        // reset template file cache
        //
        $sTemplateID = Template::get_default_template_set();
        Template::cache_template_file_hierarchy(TRUE);

        /**
         * Make sure icon variables are setup for the login page.
         */
        $icon_theme = $icon_themes[$icon_theme_def]['PATH'];
        /*
         * NOTE: The $icon_theme_path var should contain the path to the icon
         *       theme to use.  If the admin has disabled icons, or the user has
         *       set the icon theme to "None," no icons will be used.
         */
        $icon_theme_path = (!$use_icons || $icon_theme=='none') ? NULL : ($icon_theme == 'template' ? SM_PATH . Template::calculate_template_images_directory($sTemplateID) : $icon_theme);

        /**
         * cleanup old cookies with a cookie path the same as the standard php.ini
         * cookie path. All previous SquirrelMail version used the standard php.ini
         * cookie path for storing the session name. That behaviour changed.
         */
        if ($sCookiePath !== SM_BASE_URI) {
            /**
             * do not delete the standard sessions with session.name is i.e. PHPSESSID
             * because they probably belong to other php apps
             */
            if (ini_get('session.name') !== $sSessionAutostartName) {
                //  This does not work. Sometimes the cookie with SQSESSID=deleted and path /
                // is picked up in webmail.php => login will fail
                //sqsetcookie(ini_get('session.name'),'',0,$sCookiePath);
            }
        }
        break;
    default:
        require(SM_PATH . 'functions/display_messages.php' );
        require(SM_PATH . 'functions/page_header.php');
        require(SM_PATH . 'functions/html.php');


        /**
         * Check if we are logged in
         */
        require(SM_PATH . 'functions/auth.php');

        if ( !sqsession_is_registered('user_is_logged_in') ) {

            // use $message to indicate what logout text the user
            // will see... if 0, typical "You must be logged in"
            // if 1, information that the user session was saved
            // and will be resumed after (re)login
            //
            $message = 0;

            //  First we store some information in the new session to prevent
            //  information-loss.
            //
            $session_expired_post = $_POST;
            $session_expired_location = PAGE_NAME;
            if (!sqsession_is_registered('session_expired_post')) {
                sqsession_register($session_expired_post,'session_expired_post');
            }
            if (!sqsession_is_registered('session_expired_location')) {
                sqsession_register($session_expired_location,'session_expired_location');
                if ($session_expired_location == 'compose')
                    $message = 1;
            }
            // signout page will deal with users who aren't logged
            // in on its own; don't show error here
            //
            if ( PAGE_NAME == 'signout' ) {
                return;
            }

            /**
             * Initialize the template object (logout_error uses it)
             */
            /*
             * $sTemplateID is not initialized when a user is not logged in, so we
             * will use the config file defaults here.  If the neccesary variables
             * are net set, force a default value.
             */
            $sTemplateID = Template::get_default_template_set();
            $oTemplate = Template::construct_template($sTemplateID);

            set_up_language($squirrelmail_language, true);
            if (!$message)
                logout_error( _("You must be logged in to access this page.") );
            else
                logout_error( _("Your session has expired, but will be resumed after logging in again.") );
            exit;
        }

        sqgetGlobalVar('authz',$authz,SQ_SESSION);

        /**
         * Setting the prefs backend
         */
        sqgetGlobalVar('prefs_cache', $prefs_cache, SQ_SESSION );
        sqgetGlobalVar('prefs_are_cached', $prefs_are_cached, SQ_SESSION );

        if ( !sqsession_is_registered('prefs_are_cached') ||
            !isset( $prefs_cache) ||
            !is_array( $prefs_cache)) {
            $prefs_are_cached = false;
            $prefs_cache = false; //array();
        }

        /**
         * initializing user settings
         */
        require(SM_PATH . 'include/load_prefs.php');

// i do not understand the frames language cookie story
        /**
         * We'll need this to later have a noframes version
         *
         * Check if the user has a language preference, but no cookie.
         * Send him a cookie with his language preference, if there is
         * such discrepancy.
         */
         $my_language = getPref($data_dir, $username, 'language');
         if ($my_language != $squirrelmail_language) {
             sqsetcookie('squirrelmail_language', $my_language, time()+2592000, $base_uri);
         }
// /dont understand

        /**
         * Set up the language.
         */
        $err=set_up_language(getPref($data_dir, $username, 'language'));

        // Japanese translation used without mbstring support
        if ($err==2) {
            $sError = "<p>Your administrator needs to have PHP installed with the multibyte string extension enabled (using configure option --enable-mbstring).</p>\n"
                    . "<p>This system has assumed that you accidently switched to Japanese and has reverted your language preference to English.</p>\n"
                    . "<p>Please refresh this page in order to continue using your webmail.</p>\n";
            error_box($sError);
        }

        $timeZone = getPref($data_dir, $username, 'timezone');

        /* Check to see if we are allowed to set the TZ environment variable.
         * We are able to do this if ...
         *   safe_mode is disabled OR
         *   safe_mode_allowed_env_vars is empty (you are allowed to set any) OR
         *   safe_mode_allowed_env_vars contains TZ
         */
        $tzChangeAllowed = (!ini_get('safe_mode')) ||
                            !strcmp(ini_get('safe_mode_allowed_env_vars'),'') ||
                            preg_match('/^([\w_]+,)*TZ/', ini_get('safe_mode_allowed_env_vars'));

        if ( $timeZone != SMPREF_NONE && ($timeZone != "")
            && $tzChangeAllowed ) {

            // get time zone key, if strict or custom strict timezones are used
            if (isset($time_zone_type) &&
                ($time_zone_type == 1 || $time_zone_type == 3)) {
                /* load time zone functions */
                require(SM_PATH . 'include/timezones.php');
                $realTimeZone = sq_get_tz_key($timeZone);
            } else {
                $realTimeZone = $timeZone;
            }

            // set time zone
            if ($realTimeZone) {
                putenv("TZ=".$realTimeZone);
            }
        }

        /**
         * php 5.1.0 added time zone functions. Set time zone with them in order
         * to prevent E_STRICT notices and allow time zone modifications in safe_mode.
         */
        if (function_exists('date_default_timezone_set')) {
            if ($timeZone != SMPREF_NONE && $timeZone != "") {
                date_default_timezone_set($timeZone);
            } else {
                // interface runs on server's time zone. Remove php E_STRICT complains
                $default_timezone = @date_default_timezone_get();
                date_default_timezone_set($default_timezone);
            }
        }
        break;
}

/*
 * $sTemplateID is not initialized when a user is not logged in, so we
 * will use the config file defaults here.  If the neccesary variables
 * are not set, force a default value.
 *
 * If the user is logged in, $sTemplateID will be set in load_prefs.php,
 * so we shouldn't change it here.
 */
if (!isset($sTemplateID)) {
    $sTemplateID = Template::get_default_template_set();
    $icon_theme_path = !$use_icons ? NULL : Template::calculate_template_images_directory($sTemplateID);
}

// template object may have already been constructed in load_prefs.php
//
if (empty($oTemplate)) {
    $oTemplate = Template::construct_template($sTemplateID);
}

// We want some variables to always be available to the template
//
$oTemplate->assign('javascript_on', 
    (sqGetGlobalVar('user_is_logged_in', $user_is_logged_in, SQ_SESSION)
     ?  checkForJavascript() : 0));
$oTemplate->assign('base_uri', sqm_baseuri());
$always_include = array('sTemplateID', 'icon_theme_path');
foreach ($always_include as $var) {
    $oTemplate->assign($var, (isset($$var) ? $$var : NULL));
}

// A few output elements are used often, so just get them once here
//
$nbsp = $oTemplate->fetch('non_breaking_space.tpl');
$br = $oTemplate->fetch('line_break.tpl');

/**
 * Initialize our custom error handler object
 */
$oErrorHandler = new ErrorHandler($oTemplate,'error_message.tpl');

/**
 * Activate custom error handling
 */
if (version_compare(PHP_VERSION, "4.3.0", ">=")) {
    $oldErrorHandler = set_error_handler(array($oErrorHandler, 'SquirrelMailErrorhandler'));
} else {
    $oldErrorHandler = set_error_handler('SquirrelMailErrorhandler');
}


// ============================================================================
// ================= End of Live Code, Beginning of Functions ================= 
// ============================================================================


/**
 * Javascript support detection function
 * @param boolean $reset recheck javascript support if set to true.
 * @return integer SMPREF_JS_ON or SMPREF_JS_OFF ({@see include/constants.php})
 * @since 1.5.1
 */
function checkForJavascript($reset = FALSE) {
  global $data_dir, $username, $javascript_on, $javascript_setting;

  if ( !$reset && sqGetGlobalVar('javascript_on', $javascript_on, SQ_SESSION) )
    return $javascript_on;

  $user_is_logged_in = FALSE;
  if ( $reset || !isset($javascript_setting) )
    $javascript_setting = getPref($data_dir, $username, 'javascript_setting', SMPREF_JS_AUTODETECT);

  if ( !sqGetGlobalVar('new_js_autodetect_results', $js_autodetect_results) &&
       !sqGetGlobalVar('js_autodetect_results', $js_autodetect_results) )
    $js_autodetect_results = SMPREF_JS_OFF;

  if ( $javascript_setting == SMPREF_JS_AUTODETECT )
    $javascript_on = $js_autodetect_results;
  else
    $javascript_on = $javascript_setting;

  sqsession_register($javascript_on, 'javascript_on');
  return $javascript_on;
}

function sqm_baseuri() {
    global $base_uri;
    return $base_uri;
}