xref: /webtrees/app/Services/HtmlService.php (revision 534324768cedfc260deb392aa6a125c6cffc46e8) 
1<?php
2
3/**
4 * webtrees: online genealogy
5 * Copyright (C) 2019 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 <http://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;
25
26/**
27 * Filter/sanitize HTML
28 */
29class HtmlService
30{
31    /**
32     * Take some dirty HTML (as provided by the user), and clean it before
33     * we save/display it.
34     *
35     * @param string $html
36     *
37     * @return string
38     */
39    public function sanitize(string $html): string
40    {
41        $config = HTMLPurifier_Config::createDefault();
42
43        $config->set('Cache.DefinitionImpl', null);
44
45        $config->set('HTML.TidyLevel', 'none'); // Only XSS cleaning now
46
47        // Remove the default maximum width/height for images.  This enables percentage values.
48        $config->set('CSS.MaxImgLength', null);
49
50        $def = $config->getHTMLDefinition(true);
51
52        // Allow link targets.
53        $def->addAttribute('a', 'target', new HTMLPurifier_AttrDef_Enum(['_blank', '_self', '_target', '_top']));
54
55        // Allow image maps.
56        $def->addAttribute('img', 'usemap', 'CDATA');
57
58        $map = $def->addElement('map', 'Block', 'Flow', 'Common', [
59            'name'  => 'CDATA',
60            'id'    => 'ID',
61            'title' => 'CDATA',
62        ]);
63
64        $map->excludes = ['map' => true];
65
66        $area = $def->addElement('area', 'Block', 'Empty', 'Common', [
67            'name'      => 'CDATA',
68            'id'        => 'ID',
69            'alt'       => 'Text',
70            'coords'    => 'CDATA',
71            'accesskey' => 'Character',
72            'nohref'    => new HTMLPurifier_AttrDef_Enum(['nohref']),
73            'href'      => 'URI',
74            'shape'     => new HTMLPurifier_AttrDef_Enum(['rect', 'circle', 'poly', 'default']),
75            'tabindex'  => 'Number',
76        ]);
77
78        $area->excludes = ['area' => true];
79
80        $purifier = new HTMLPurifier($config);
81
82        return $purifier->purify($html);
83    }
84}
85