htmlpurifier/library/HTMLPurifier/Config.php

<?php

/**
 * Configuration object that triggers customizable behavior.
 *
 * @warning This class is strongly defined: that means that the class
 *          will fail if an undefined directive is retrieved or set.
 *
 * @note Many classes that could (although many times don't) use the
 *       configuration object make it a mandatory parameter.  This is
 *       because a configuration object should always be forwarded,
 *       otherwise, you run the risk of missing a parameter and then
 *       being stumped when a configuration directive doesn't work.
 *
 * @todo Reconsider some of the public member variables
 */
class HTMLPurifier_Config
{

    /**
     * HTML Purifier's version
     */
    public $version = '4.2.0';

    /**
     * Bool indicator whether or not to automatically finalize
     * the object if a read operation is done
     */
    public $autoFinalize = true;

    // protected member variables

    /**
     * Namespace indexed array of serials for specific namespaces (see
     * getSerial() for more info).
     */
    protected $serials = array();

    /**
     * Serial for entire configuration object
     */
    protected $serial;

    /**
     * Parser for variables
     */
    protected $parser;

    /**
     * Reference HTMLPurifier_ConfigSchema for value checking
     * @note This is public for introspective purposes. Please don't
     *       abuse!
     */
    public $def;

    /**
     * Indexed array of definitions
     */
    protected $definitions;

    /**
     * Bool indicator whether or not config is finalized
     */
    protected $finalized = false;

    /**
     * Property list containing configuration directives.
     */
    protected $plist;

    /**
     * Whether or not a set is taking place due to an
     * alias lookup.
     */
    private $aliasMode;

    /**
     * Set to false if you do not want line and file numbers in errors
     * (useful when unit testing)
     */
    public $chatty = true;

    /**
     * Current lock; only gets to this namespace are allowed.
     */
    private $lock;

    /**
     * @param $definition HTMLPurifier_ConfigSchema that defines what directives
     *                    are allowed.
     */
    public function __construct($definition, $parent = null) {
        $parent = $parent ? $parent : $definition->defaultPlist;
        $this->plist = new HTMLPurifier_PropertyList($parent);
        $this->def = $definition; // keep a copy around for checking
        $this->parser = new HTMLPurifier_VarParser_Flexible();
    }

    /**
     * Convenience constructor that creates a config object based on a mixed var
     * @param mixed $config Variable that defines the state of the config
     *                      object. Can be: a HTMLPurifier_Config() object,
     *                      an array of directives based on loadArray(),
     *                      or a string filename of an ini file.
     * @param HTMLPurifier_ConfigSchema Schema object
     * @return Configured HTMLPurifier_Config object
     */
    public static function create($config, $schema = null) {
        if ($config instanceof HTMLPurifier_Config) {
            // pass-through
            return $config;
        }
        if (!$schema) {
            $ret = HTMLPurifier_Config::createDefault();
        } else {
            $ret = new HTMLPurifier_Config($schema);
        }
        if (is_string($config)) $ret->loadIni($config);
        elseif (is_array($config)) $ret->loadArray($config);
        return $ret;
    }

    /**
     * Creates a new config object that inherits from a previous one.
     * @param HTMLPurifier_Config $config Configuration object to inherit
     *        from.
     * @return HTMLPurifier_Config object with $config as its parent.
     */
    public static function inherit(HTMLPurifier_Config $config) {
        return new HTMLPurifier_Config($config->def, $config->plist);
    }

    /**
     * Convenience constructor that creates a default configuration object.
     * @return Default HTMLPurifier_Config object.
     */
    public static function createDefault() {
        $definition = HTMLPurifier_ConfigSchema::instance();
        $config = new HTMLPurifier_Config($definition);
        return $config;
    }

    /**
     * Retreives a value from the configuration.
     * @param $key String key
     */
    public function get($key, $a = null) {
        if ($a !== null) {
            $this->triggerError("Using deprecated API: use \$config->get('$key.$a') instead", E_USER_WARNING);
            $key = "$key.$a";
        }
        if (!$this->finalized) $this->autoFinalize();
        if (!isset($this->def->info[$key])) {
            // can't add % due to SimpleTest bug
            $this->triggerError('Cannot retrieve value of undefined directive ' . htmlspecialchars($key),
                E_USER_WARNING);
            return;
        }
        if (isset($this->def->info[$key]->isAlias)) {
            $d = $this->def->info[$key];
            $this->triggerError('Cannot get value from aliased directive, use real name ' . $d->key,
                E_USER_ERROR);
            return;
        }
        if ($this->lock) {
            list($ns) = explode('.', $key);
            if ($ns !== $this->lock) {
                $this->triggerError('Cannot get value of namespace ' . $ns . ' when lock for ' . $this->lock . ' is active, this probably indicates a Definition setup method is accessing directives that are not within its namespace', E_USER_ERROR);
                return;
            }
        }
        return $this->plist->get($key);
    }

    /**
     * Retreives an array of directives to values from a given namespace
     * @param $namespace String namespace
     */
    public function getBatch($namespace) {
        if (!$this->finalized) $this->autoFinalize();
        $full = $this->getAll();
        if (!isset($full[$namespace])) {
            $this->triggerError('Cannot retrieve undefined namespace ' . htmlspecialchars($namespace),
                E_USER_WARNING);
            return;
        }
        return $full[$namespace];
    }

    /**
     * Returns a md5 signature of a segment of the configuration object
     * that uniquely identifies that particular configuration
     * @note Revision is handled specially and is removed from the batch
     *       before processing!
     * @param $namespace Namespace to get serial for
     */
    public function getBatchSerial($namespace) {
        if (empty($this->serials[$namespace])) {
            $batch = $this->getBatch($namespace);
            unset($batch['DefinitionRev']);
            $this->serials[$namespace] = md5(serialize($batch));
        }
        return $this->serials[$namespace];
    }

    /**
     * Returns a md5 signature for the entire configuration object
     * that uniquely identifies that particular configuration
     */
    public function getSerial() {
        if (empty($this->serial)) {
            $this->serial = md5(serialize($this->getAll()));
        }
        return $this->serial;
    }

    /**
     * Retrieves all directives, organized by namespace
     * @warning This is a pretty inefficient function, avoid if you can
     */
    public function getAll() {
        if (!$this->finalized) $this->autoFinalize();
        $ret = array();
        foreach ($this->plist->squash() as $name => $value) {
            list($ns, $key) = explode('.', $name, 2);
            $ret[$ns][$key] = $value;
        }
        return $ret;
    }

    /**
     * Sets a value to configuration.
     * @param $key String key
     * @param $value Mixed value
     */
    public function set($key, $value, $a = null) {
        if (strpos($key, '.') === false) {
            $namespace = $key;
            $directive = $value;
            $value = $a;
            $key = "$key.$directive";
            $this->triggerError("Using deprecated API: use \$config->set('$key', ...) instead", E_USER_NOTICE);
        } else {
            list($namespace) = explode('.', $key);
        }
        if ($this->isFinalized('Cannot set directive after finalization')) return;
        if (!isset($this->def->info[$key])) {
            $this->triggerError('Cannot set undefined directive ' . htmlspecialchars($key) . ' to value',
                E_USER_WARNING);
            return;
        }
        $def = $this->def->info[$key];

        if (isset($def->isAlias)) {
            if ($this->aliasMode) {
                $this->triggerError('Double-aliases not allowed, please fix '.
                    'ConfigSchema bug with' . $key, E_USER_ERROR);
                return;
            }
            $this->aliasMode = true;
            $this->set($def->key, $value);
            $this->aliasMode = false;
            $this->triggerError("$key is an alias, preferred directive name is {$def->key}", E_USER_NOTICE);
            return;
        }

        // Raw type might be negative when using the fully optimized form
        // of stdclass, which indicates allow_null == true
        $rtype = is_int($def) ? $def : $def->type;
        if ($rtype < 0) {
            $type = -$rtype;
            $allow_null = true;
        } else {
            $type = $rtype;
            $allow_null = isset($def->allow_null);
        }

        try {
            $value = $this->parser->parse($value, $type, $allow_null);
        } catch (HTMLPurifier_VarParserException $e) {
            $this->triggerError('Value for ' . $key . ' is of invalid type, should be ' . HTMLPurifier_VarParser::getTypeName($type), E_USER_WARNING);
            return;
        }
        if (is_string($value) && is_object($def)) {
            // resolve value alias if defined
            if (isset($def->aliases[$value])) {
                $value = $def->aliases[$value];
            }
            // check to see if the value is allowed
            if (isset($def->allowed) && !isset($def->allowed[$value])) {
                $this->triggerError('Value not supported, valid values are: ' .
                    $this->_listify($def->allowed), E_USER_WARNING);
                return;
            }
        }
        $this->plist->set($key, $value);

        // reset definitions if the directives they depend on changed
        // this is a very costly process, so it's discouraged
        // with finalization
        if ($namespace == 'HTML' || $namespace == 'CSS' || $namespace == 'URI') {
            $this->definitions[$namespace] = null;
        }

        $this->serials[$namespace] = false;
    }

    /**
     * Convenience function for error reporting
     */
    private function _listify($lookup) {
        $list = array();
        foreach ($lookup as $name => $b) $list[] = $name;
        return implode(', ', $list);
    }

    /**
     * Retrieves object reference to the HTML definition.
     * @param $raw Return a copy that has not been setup yet. Must be
     *             called before it's been setup, otherwise won't work.
     */
    public function getHTMLDefinition($raw = false) {
        return $this->getDefinition('HTML', $raw);
    }

    /**
     * Retrieves object reference to the CSS definition
     * @param $raw Return a copy that has not been setup yet. Must be
     *             called before it's been setup, otherwise won't work.
     */
    public function getCSSDefinition($raw = false) {
        return $this->getDefinition('CSS', $raw);
    }

    /**
     * Retrieves a definition
     * @param $type Type of definition: HTML, CSS, etc
     * @param $raw  Whether or not definition should be returned raw
     */
    public function getDefinition($type, $raw = false) {
        if (!$this->finalized) $this->autoFinalize();
        // temporarily suspend locks, so we can handle recursive definition calls
        $lock = $this->lock;
        $this->lock = null;
        $factory = HTMLPurifier_DefinitionCacheFactory::instance();
        $cache = $factory->create($type, $this);
        $this->lock = $lock;
        if (!$raw) {
            // see if we can quickly supply a definition
            if (!empty($this->definitions[$type])) {
                if (!$this->definitions[$type]->setup) {
                    $this->definitions[$type]->setup($this);
                    $cache->set($this->definitions[$type], $this);
                }
                return $this->definitions[$type];
            }
            // memory check missed, try cache
            $this->definitions[$type] = $cache->get($this);
            if ($this->definitions[$type]) {
                // definition in cache, return it
                return $this->definitions[$type];
            }
        } elseif (
            !empty($this->definitions[$type]) &&
            !$this->definitions[$type]->setup
        ) {
            // raw requested, raw in memory, quick return
            return $this->definitions[$type];
        }
        // quick checks failed, let's create the object
        if ($type == 'HTML') {
            $this->definitions[$type] = new HTMLPurifier_HTMLDefinition();
        } elseif ($type == 'CSS') {
            $this->definitions[$type] = new HTMLPurifier_CSSDefinition();
        } elseif ($type == 'URI') {
            $this->definitions[$type] = new HTMLPurifier_URIDefinition();
        } else {
            throw new HTMLPurifier_Exception("Definition of $type type not supported");
        }
        // quick abort if raw
        if ($raw) {
            if (is_null($this->get($type . '.DefinitionID'))) {
                // fatally error out if definition ID not set
                throw new HTMLPurifier_Exception("Cannot retrieve raw version without specifying %$type.DefinitionID");
            }
            return $this->definitions[$type];
        }
        // set it up
        $this->lock = $type;
        $this->definitions[$type]->setup($this);
        $this->lock = null;
        // save in cache
        $cache->set($this->definitions[$type], $this);
        return $this->definitions[$type];
    }

    /**
     * Loads configuration values from an array with the following structure:
     * Namespace.Directive => Value
     * @param $config_array Configuration associative array
     */
    public function loadArray($config_array) {
        if ($this->isFinalized('Cannot load directives after finalization')) return;
        foreach ($config_array as $key => $value) {
            $key = str_replace('_', '.', $key);
            if (strpos($key, '.') !== false) {
                $this->set($key, $value);
            } else {
                $namespace = $key;
                $namespace_values = $value;
                foreach ($namespace_values as $directive => $value) {
                    $this->set($namespace .'.'. $directive, $value);
                }
            }
        }
    }

    /**
     * Returns a list of array(namespace, directive) for all directives
     * that are allowed in a web-form context as per an allowed
     * namespaces/directives list.
     * @param $allowed List of allowed namespaces/directives
     */
    public static function getAllowedDirectivesForForm($allowed, $schema = null) {
        if (!$schema) {
            $schema = HTMLPurifier_ConfigSchema::instance();
        }
        if ($allowed !== true) {
             if (is_string($allowed)) $allowed = array($allowed);
             $allowed_ns = array();
             $allowed_directives = array();
             $blacklisted_directives = array();
             foreach ($allowed as $ns_or_directive) {
                 if (strpos($ns_or_directive, '.') !== false) {
                     // directive
                     if ($ns_or_directive[0] == '-') {
                         $blacklisted_directives[substr($ns_or_directive, 1)] = true;
                     } else {
                         $allowed_directives[$ns_or_directive] = true;
                     }
                 } else {
                     // namespace
                     $allowed_ns[$ns_or_directive] = true;
                 }
             }
        }
        $ret = array();
        foreach ($schema->info as $key => $def) {
            list($ns, $directive) = explode('.', $key, 2);
            if ($allowed !== true) {
                if (isset($blacklisted_directives["$ns.$directive"])) continue;
                if (!isset($allowed_directives["$ns.$directive"]) && !isset($allowed_ns[$ns])) continue;
            }
            if (isset($def->isAlias)) continue;
            if ($directive == 'DefinitionID' || $directive == 'DefinitionRev') continue;
            $ret[] = array($ns, $directive);
        }
        return $ret;
    }

    /**
     * Loads configuration values from $_GET/$_POST that were posted
     * via ConfigForm
     * @param $array $_GET or $_POST array to import
     * @param $index Index/name that the config variables are in
     * @param $allowed List of allowed namespaces/directives
     * @param $mq_fix Boolean whether or not to enable magic quotes fix
     * @param $schema Instance of HTMLPurifier_ConfigSchema to use, if not global copy
     */
    public static function loadArrayFromForm($array, $index = false, $allowed = true, $mq_fix = true, $schema = null) {
        $ret = HTMLPurifier_Config::prepareArrayFromForm($array, $index, $allowed, $mq_fix, $schema);
        $config = HTMLPurifier_Config::create($ret, $schema);
        return $config;
    }

    /**
     * Merges in configuration values from $_GET/$_POST to object. NOT STATIC.
     * @note Same parameters as loadArrayFromForm
     */
    public function mergeArrayFromForm($array, $index = false, $allowed = true, $mq_fix = true) {
         $ret = HTMLPurifier_Config::prepareArrayFromForm($array, $index, $allowed, $mq_fix, $this->def);
         $this->loadArray($ret);
    }

    /**
     * Prepares an array from a form into something usable for the more
     * strict parts of HTMLPurifier_Config
     */
    public static function prepareArrayFromForm($array, $index = false, $allowed = true, $mq_fix = true, $schema = null) {
        if ($index !== false) $array = (isset($array[$index]) && is_array($array[$index])) ? $array[$index] : array();
        $mq = $mq_fix && function_exists('get_magic_quotes_gpc') && get_magic_quotes_gpc();

        $allowed = HTMLPurifier_Config::getAllowedDirectivesForForm($allowed, $schema);
        $ret = array();
        foreach ($allowed as $key) {
            list($ns, $directive) = $key;
            $skey = "$ns.$directive";
            if (!empty($array["Null_$skey"])) {
                $ret[$ns][$directive] = null;
                continue;
            }
            if (!isset($array[$skey])) continue;
            $value = $mq ? stripslashes($array[$skey]) : $array[$skey];
            $ret[$ns][$directive] = $value;
        }
        return $ret;
    }

    /**
     * Loads configuration values from an ini file
     * @param $filename Name of ini file
     */
    public function loadIni($filename) {
        if ($this->isFinalized('Cannot load directives after finalization')) return;
        $array = parse_ini_file($filename, true);
        $this->loadArray($array);
    }

    /**
     * Checks whether or not the configuration object is finalized.
     * @param $error String error message, or false for no error
     */
    public function isFinalized($error = false) {
        if ($this->finalized && $error) {
            $this->triggerError($error, E_USER_ERROR);
        }
        return $this->finalized;
    }

    /**
     * Finalizes configuration only if auto finalize is on and not
     * already finalized
     */
    public function autoFinalize() {
        if ($this->autoFinalize) {
            $this->finalize();
        } else {
            $this->plist->squash(true);
        }
    }

    /**
     * Finalizes a configuration object, prohibiting further change
     */
    public function finalize() {
        $this->finalized = true;
        unset($this->parser);
    }

    /**
     * Produces a nicely formatted error message by supplying the
     * stack frame information from two levels up and OUTSIDE of
     * HTMLPurifier_Config.
     */
    protected function triggerError($msg, $no) {
        // determine previous stack frame
        $backtrace = debug_backtrace();
        if ($this->chatty && isset($backtrace[1])) {
            $frame = $backtrace[1];
            $extra = " on line {$frame['line']} in file {$frame['file']}";
        } else {
            $extra = '';
        }
        trigger_error($msg . $extra, $no);
    }

    /**
     * Returns a serialized form of the configuration object that can
     * be reconstituted.
     */
    public function serialize() {
        $this->getDefinition('HTML');
        $this->getDefinition('CSS');
        $this->getDefinition('URI');
        return serialize($this);
    }

}

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