1<?php
2
3/*
4 * This file is part of Twig.
5 *
6 * (c) 2009 Fabien Potencier
7 *
8 * For the full copyright and license information, please view the LICENSE
9 * file that was distributed with this source code.
10 */
11
12/**
13 * Represents a security policy which need to be enforced when sandbox mode is enabled.
14 *
15 * @final
16 *
17 * @author Fabien Potencier <fabien@symfony.com>
18 */
19class Twig_Sandbox_SecurityPolicy implements Twig_Sandbox_SecurityPolicyInterface
20{
21    protected $allowedTags;
22    protected $allowedFilters;
23    protected $allowedMethods;
24    protected $allowedProperties;
25    protected $allowedFunctions;
26
27    public function __construct(array $allowedTags = array(), array $allowedFilters = array(), array $allowedMethods = array(), array $allowedProperties = array(), array $allowedFunctions = array())
28    {
29        $this->allowedTags = $allowedTags;
30        $this->allowedFilters = $allowedFilters;
31        $this->setAllowedMethods($allowedMethods);
32        $this->allowedProperties = $allowedProperties;
33        $this->allowedFunctions = $allowedFunctions;
34    }
35
36    public function setAllowedTags(array $tags)
37    {
38        $this->allowedTags = $tags;
39    }
40
41    public function setAllowedFilters(array $filters)
42    {
43        $this->allowedFilters = $filters;
44    }
45
46    public function setAllowedMethods(array $methods)
47    {
48        $this->allowedMethods = array();
49        foreach ($methods as $class => $m) {
50            $this->allowedMethods[$class] = array_map('strtolower', is_array($m) ? $m : array($m));
51        }
52    }
53
54    public function setAllowedProperties(array $properties)
55    {
56        $this->allowedProperties = $properties;
57    }
58
59    public function setAllowedFunctions(array $functions)
60    {
61        $this->allowedFunctions = $functions;
62    }
63
64    public function checkSecurity($tags, $filters, $functions)
65    {
66        foreach ($tags as $tag) {
67            if (!in_array($tag, $this->allowedTags)) {
68                throw new Twig_Sandbox_SecurityNotAllowedTagError(sprintf('Tag "%s" is not allowed.', $tag), $tag);
69            }
70        }
71
72        foreach ($filters as $filter) {
73            if (!in_array($filter, $this->allowedFilters)) {
74                throw new Twig_Sandbox_SecurityNotAllowedFilterError(sprintf('Filter "%s" is not allowed.', $filter), $filter);
75            }
76        }
77
78        foreach ($functions as $function) {
79            if (!in_array($function, $this->allowedFunctions)) {
80                throw new Twig_Sandbox_SecurityNotAllowedFunctionError(sprintf('Function "%s" is not allowed.', $function), $function);
81            }
82        }
83    }
84
85    public function checkMethodAllowed($obj, $method)
86    {
87        if ($obj instanceof Twig_TemplateInterface || $obj instanceof Twig_Markup) {
88            return true;
89        }
90
91        $allowed = false;
92        $method = strtolower($method);
93        foreach ($this->allowedMethods as $class => $methods) {
94            if ($obj instanceof $class) {
95                $allowed = in_array($method, $methods);
96
97                break;
98            }
99        }
100
101        if (!$allowed) {
102            $class = get_class($obj);
103            throw new Twig_Sandbox_SecurityNotAllowedMethodError(sprintf('Calling "%s" method on a "%s" object is not allowed.', $method, $class), $class, $method);
104        }
105    }
106
107    public function checkPropertyAllowed($obj, $property)
108    {
109        $allowed = false;
110        foreach ($this->allowedProperties as $class => $properties) {
111            if ($obj instanceof $class) {
112                $allowed = in_array($property, is_array($properties) ? $properties : array($properties));
113
114                break;
115            }
116        }
117
118        if (!$allowed) {
119            $class = get_class($obj);
120            throw new Twig_Sandbox_SecurityNotAllowedPropertyError(sprintf('Calling "%s" property on a "%s" object is not allowed.', $property, $class), $class, $property);
121        }
122    }
123}
124