xref: /webtrees/app/Services/HtmlService.php (revision afa67798854828b1edc33dd077960ec2b18e6140) 
1<?php
2
3/**
4 * webtrees: online genealogy
5 * Copyright (C) 2021 webtrees development team
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <https://www.gnu.org/licenses/>.
16 */
17
18declare(strict_types=1);
19
20namespace Fisharebest\Webtrees\Services;
21
22use HTMLPurifier;
23use HTMLPurifier_AttrDef_Enum;
24use HTMLPurifier_Config;
25use HTMLPurifier_HTMLDefinition;
26
27use function assert;
28
29/**
30 * Filter/sanitize HTML
31 */
32class HtmlService
33{
34    /**
35     * Take some dirty HTML (as provided by the user), and clean it before
36     * we save/display it.
37     *
38     * @param string $html
39     *
40     * @return string
41     */
42    public function sanitize(string $html): string
43    {
44        $config = HTMLPurifier_Config::createDefault();
45
46        $config->set('Cache.DefinitionImpl', null);
47
48        $config->set('HTML.TidyLevel', 'none'); // Only XSS cleaning now
49
50        // Remove the default maximum width/height for images.  This enables percentage values.
51        $config->set('CSS.MaxImgLength', null);
52
53        // Allow id attributes.
54        $config->set('Attr.EnableID', true);
55
56        $def = $config->getHTMLDefinition(true);
57        assert($def instanceof HTMLPurifier_HTMLDefinition);
58
59        // Allow link targets.
60        $def->addAttribute('a', 'target', new HTMLPurifier_AttrDef_Enum(['_blank', '_self', '_target', '_top']));
61
62        // Allow image maps.
63        $def->addAttribute('img', 'usemap', 'CDATA');
64
65        $map = $def->addElement('map', 'Block', 'Flow', 'Common', [
66            'name'  => 'CDATA',
67            'id'    => 'ID',
68            'title' => 'CDATA',
69        ]);
70
71        $map->excludes = ['map' => true];
72
73        $area = $def->addElement('area', 'Block', 'Empty', 'Common', [
74            'name'      => 'CDATA',
75            'id'        => 'ID',
76            'alt'       => 'Text',
77            'coords'    => 'CDATA',
78            'accesskey' => 'Character',
79            'nohref'    => new HTMLPurifier_AttrDef_Enum(['nohref']),
80            'href'      => 'URI',
81            'shape'     => new HTMLPurifier_AttrDef_Enum(['rect', 'circle', 'poly', 'default']),
82            'tabindex'  => 'Number',
83        ]);
84
85        $area->excludes = ['area' => true];
86
87        $purifier = new HTMLPurifier($config);
88
89        return $purifier->purify($html);
90    }
91}
92