1<?php
2
3/*
4 * This file is part of Twig.
5 *
6 * (c) 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
12namespace Twig\NodeVisitor;
13
14use Twig\Environment;
15use Twig\Node\CheckSecurityCallNode;
16use Twig\Node\CheckSecurityNode;
17use Twig\Node\CheckToStringNode;
18use Twig\Node\Expression\Binary\ConcatBinary;
19use Twig\Node\Expression\Binary\RangeBinary;
20use Twig\Node\Expression\FilterExpression;
21use Twig\Node\Expression\FunctionExpression;
22use Twig\Node\Expression\GetAttrExpression;
23use Twig\Node\Expression\NameExpression;
24use Twig\Node\ModuleNode;
25use Twig\Node\Node;
26use Twig\Node\PrintNode;
27use Twig\Node\SetNode;
28
29/**
30 * @author Fabien Potencier <fabien@symfony.com>
31 */
32final class SandboxNodeVisitor extends AbstractNodeVisitor
33{
34    private $inAModule = false;
35    private $tags;
36    private $filters;
37    private $functions;
38
39    private $needsToStringWrap = false;
40
41    protected function doEnterNode(Node $node, Environment $env)
42    {
43        if ($node instanceof ModuleNode) {
44            $this->inAModule = true;
45            $this->tags = [];
46            $this->filters = [];
47            $this->functions = [];
48
49            return $node;
50        } elseif ($this->inAModule) {
51            // look for tags
52            if ($node->getNodeTag() && !isset($this->tags[$node->getNodeTag()])) {
53                $this->tags[$node->getNodeTag()] = $node;
54            }
55
56            // look for filters
57            if ($node instanceof FilterExpression && !isset($this->filters[$node->getNode('filter')->getAttribute('value')])) {
58                $this->filters[$node->getNode('filter')->getAttribute('value')] = $node;
59            }
60
61            // look for functions
62            if ($node instanceof FunctionExpression && !isset($this->functions[$node->getAttribute('name')])) {
63                $this->functions[$node->getAttribute('name')] = $node;
64            }
65
66            // the .. operator is equivalent to the range() function
67            if ($node instanceof RangeBinary && !isset($this->functions['range'])) {
68                $this->functions['range'] = $node;
69            }
70
71            if ($node instanceof PrintNode) {
72                $this->needsToStringWrap = true;
73                $this->wrapNode($node, 'expr');
74            }
75
76            if ($node instanceof SetNode && !$node->getAttribute('capture')) {
77                $this->needsToStringWrap = true;
78            }
79
80            // wrap outer nodes that can implicitly call __toString()
81            if ($this->needsToStringWrap) {
82                if ($node instanceof ConcatBinary) {
83                    $this->wrapNode($node, 'left');
84                    $this->wrapNode($node, 'right');
85                }
86                if ($node instanceof FilterExpression) {
87                    $this->wrapNode($node, 'node');
88                    $this->wrapArrayNode($node, 'arguments');
89                }
90                if ($node instanceof FunctionExpression) {
91                    $this->wrapArrayNode($node, 'arguments');
92                }
93            }
94        }
95
96        return $node;
97    }
98
99    protected function doLeaveNode(Node $node, Environment $env)
100    {
101        if ($node instanceof ModuleNode) {
102            $this->inAModule = false;
103
104            $node->setNode('constructor_end', new Node([new CheckSecurityCallNode(), $node->getNode('constructor_end')]));
105            $node->setNode('class_end', new Node([new CheckSecurityNode($this->filters, $this->tags, $this->functions), $node->getNode('class_end')]));
106        } elseif ($this->inAModule) {
107            if ($node instanceof PrintNode || $node instanceof SetNode) {
108                $this->needsToStringWrap = false;
109            }
110        }
111
112        return $node;
113    }
114
115    private function wrapNode(Node $node, string $name)
116    {
117        $expr = $node->getNode($name);
118        if ($expr instanceof NameExpression || $expr instanceof GetAttrExpression) {
119            $node->setNode($name, new CheckToStringNode($expr));
120        }
121    }
122
123    private function wrapArrayNode(Node $node, string $name)
124    {
125        $args = $node->getNode($name);
126        foreach ($args as $name => $_) {
127            $this->wrapNode($args, $name);
128        }
129    }
130
131    public function getPriority()
132    {
133        return 0;
134    }
135}
136
137class_alias('Twig\NodeVisitor\SandboxNodeVisitor', 'Twig_NodeVisitor_Sandbox');
138