PMA\libraries\plugins\auth\AuthenticationSignon::authCheck PHP Method

    public function authCheck()
    {
        global $PHP_AUTH_USER, $PHP_AUTH_PW;
        /* Check if we're using same signon server */
        $signon_url = $GLOBALS['cfg']['Server']['SignonURL'];
        if (isset($_SESSION['LAST_SIGNON_URL']) && $_SESSION['LAST_SIGNON_URL'] != $signon_url) {
            return false;
        }
        /* Script name */
        $script_name = $GLOBALS['cfg']['Server']['SignonScript'];
        /* Session name */
        $session_name = $GLOBALS['cfg']['Server']['SignonSession'];
        /* Login URL */
        $signon_url = $GLOBALS['cfg']['Server']['SignonURL'];
        /* Current host */
        $single_signon_host = $GLOBALS['cfg']['Server']['host'];
        /* Current port */
        $single_signon_port = $GLOBALS['cfg']['Server']['port'];
        /* No configuration updates */
        $single_signon_cfgupdate = array();
        /* Handle script based auth */
        if (!empty($script_name)) {
            if (!file_exists($script_name)) {
                PMA_fatalError(__('Can not find signon authentication script:') . ' ' . $script_name);
            }
            include $script_name;
            list($PHP_AUTH_USER, $PHP_AUTH_PW) = get_login_credentials($GLOBALS['cfg']['Server']['user']);
        } elseif (isset($_COOKIE[$session_name])) {
            /* Does session exist? */
            /* End current session */
            $old_session = session_name();
            $old_id = session_id();
            if (!defined('TESTSUITE')) {
                session_write_close();
            }
            /* Load single signon session */
            session_name($session_name);
            session_id($_COOKIE[$session_name]);
            if (!defined('TESTSUITE')) {
                session_start();
            }
            /* Clear error message */
            unset($_SESSION['PMA_single_signon_error_message']);
            /* Grab credentials if they exist */
            if (isset($_SESSION['PMA_single_signon_user'])) {
                $PHP_AUTH_USER = $_SESSION['PMA_single_signon_user'];
            }
            if (isset($_SESSION['PMA_single_signon_password'])) {
                $PHP_AUTH_PW = $_SESSION['PMA_single_signon_password'];
            }
            if (isset($_SESSION['PMA_single_signon_host'])) {
                $single_signon_host = $_SESSION['PMA_single_signon_host'];
            }
            if (isset($_SESSION['PMA_single_signon_port'])) {
                $single_signon_port = $_SESSION['PMA_single_signon_port'];
            }
            if (isset($_SESSION['PMA_single_signon_cfgupdate'])) {
                $single_signon_cfgupdate = $_SESSION['PMA_single_signon_cfgupdate'];
            }
            /* Also get token as it is needed to access subpages */
            if (isset($_SESSION['PMA_single_signon_token'])) {
                /* No need to care about token on logout */
                $pma_token = $_SESSION['PMA_single_signon_token'];
            }
            /* End single signon session */
            if (!defined('TESTSUITE')) {
                session_write_close();
            }
            /* Restart phpMyAdmin session */
            session_name($old_session);
            if (!empty($old_id)) {
                session_id($old_id);
            }
            if (!defined('TESTSUITE')) {
                session_start();
            }
            /* Set the single signon host */
            $GLOBALS['cfg']['Server']['host'] = $single_signon_host;
            /* Set the single signon port */
            $GLOBALS['cfg']['Server']['port'] = $single_signon_port;
            /* Configuration update */
            $GLOBALS['cfg']['Server'] = array_merge($GLOBALS['cfg']['Server'], $single_signon_cfgupdate);
            /* Restore our token */
            if (!empty($pma_token)) {
                $_SESSION[' PMA_token '] = $pma_token;
            }
            /**
             * Clear user cache.
             */
            PMA\libraries\Util::clearUserCache();
        }
        // Returns whether we get authentication settings or not
        if (empty($PHP_AUTH_USER)) {
            unset($_SESSION['LAST_SIGNON_URL']);
            return false;
        } else {
            $_SESSION['LAST_SIGNON_URL'] = $GLOBALS['cfg']['Server']['SignonURL'];
            return true;
        }
    }