<?php

/*

 * This file is part of Twig.

 *

 * (c) 2009 Fabien Potencier

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 */

/**

 * Represents a security policy which need to be enforced when sandbox mode is enabled.

 *

 * @package    twig

 * @author     Fabien Potencier <fabien@symfony.com>

 */

class Twig_Sandbox_SecurityPolicy implements Twig_Sandbox_SecurityPolicyInterface

{

    protected $allowedTags;

    protected $allowedFilters;

    protected $allowedMethods;

    protected $allowedProperties;

    protected $allowedFunctions;

    public function __construct(array $allowedTags = array(), array $allowedFilters = array(), array $allowedMethods = array(), array $allowedProperties = array(), array $allowedFunctions = array())

    {

        $this->allowedTags = $allowedTags;

        $this->allowedFilters = $allowedFilters;

        $this->setAllowedMethods($allowedMethods);

        $this->allowedProperties = $allowedProperties;

        $this->allowedFunctions = $allowedFunctions;

    }

    public function setAllowedTags(array $tags)

    {

        $this->allowedTags = $tags;

    }

    public function setAllowedFilters(array $filters)

    {

        $this->allowedFilters = $filters;

    }

    public function setAllowedMethods(array $methods)

    {

        $this->allowedMethods = array();

        foreach ($methods as $class => $m) {

            $this->allowedMethods[$class] = array_map('strtolower', is_array($m) ? $m : array($m));

        }

    }

    public function setAllowedProperties(array $properties)

    {

        $this->allowedProperties = $properties;

    }

    public function setAllowedFunctions(array $functions)

    {

        $this->allowedFunctions = $functions;

    }

    public function checkSecurity($tags, $filters, $functions)

    {

        foreach ($tags as $tag) {

            if (!in_array($tag, $this->allowedTags)) {

                throw new Twig_Sandbox_SecurityError(sprintf('Tag "%s" is not allowed.', $tag));

            }

        }

        foreach ($filters as $filter) {

            if (!in_array($filter, $this->allowedFilters)) {

                throw new Twig_Sandbox_SecurityError(sprintf('Filter "%s" is not allowed.', $filter));

            }

        }

        foreach ($functions as $function) {

            if (!in_array($function, $this->allowedFunctions)) {

                throw new Twig_Sandbox_SecurityError(sprintf('Function "%s" is not allowed.', $function));

            }

        }

    }

    public function checkMethodAllowed($obj, $method)

    {

        if ($obj instanceof Twig_TemplateInterface || $obj instanceof Twig_Markup) {

            return true;

        }

        $allowed = false;

        $method = strtolower($method);

        foreach ($this->allowedMethods as $class => $methods) {

            if ($obj instanceof $class) {

                $allowed = in_array($method, $methods);

                break;

            }

        }

        if (!$allowed) {

            throw new Twig_Sandbox_SecurityError(sprintf('Calling "%s" method on a "%s" object is not allowed.', $method, get_class($obj)));

        }

    }

    public function checkPropertyAllowed($obj, $property)

    {

        $allowed = false;

        foreach ($this->allowedProperties as $class => $properties) {

            if ($obj instanceof $class) {

                $allowed = in_array($property, is_array($properties) ? $properties : array($properties));

                break;

            }

        }

        if (!$allowed) {

            throw new Twig_Sandbox_SecurityError(sprintf('Calling "%s" property on a "%s" object is not allowed.', $property, get_class($obj)));

        }

    }

}