leilukin-tumbleblog/includes/lib/Twig/Runtime/EscaperRuntime.php

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2024-06-20 14:10:42 +00:00
<?php
/*
* This file is part of Twig.
*
* (c) Fabien Potencier
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Twig\Runtime;
use Twig\Error\RuntimeError;
use Twig\Extension\RuntimeExtensionInterface;
use Twig\Markup;
final class EscaperRuntime implements RuntimeExtensionInterface
{
private $escapers = [];
/** @internal */
public $safeClasses = [];
/** @internal */
public $safeLookup = [];
private $charset;
public function __construct($charset = 'UTF-8')
{
$this->charset = $charset;
}
/**
* Defines a new escaper to be used via the escape filter.
*
* @param string $strategy The strategy name that should be used as a strategy in the escape call
* @param callable(string $string, string $charset) $callable A valid PHP callable
*/
public function setEscaper($strategy, callable $callable)
{
$this->escapers[$strategy] = $callable;
}
/**
* Gets all defined escapers.
*
* @return array<callable(string $string, string $charset)> An array of escapers
*/
public function getEscapers()
{
return $this->escapers;
}
public function setSafeClasses(array $safeClasses = [])
{
$this->safeClasses = [];
$this->safeLookup = [];
foreach ($safeClasses as $class => $strategies) {
$this->addSafeClass($class, $strategies);
}
}
public function addSafeClass(string $class, array $strategies)
{
$class = ltrim($class, '\\');
if (!isset($this->safeClasses[$class])) {
$this->safeClasses[$class] = [];
}
$this->safeClasses[$class] = array_merge($this->safeClasses[$class], $strategies);
foreach ($strategies as $strategy) {
$this->safeLookup[$strategy][$class] = true;
}
}
/**
* Escapes a string.
*
* @param mixed $string The value to be escaped
* @param string $strategy The escaping strategy
* @param string|null $charset The charset
* @param bool $autoescape Whether the function is called by the auto-escaping feature (true) or by the developer (false)
*
* @throws RuntimeError
*/
public function escape($string, string $strategy = 'html', ?string $charset = null, bool $autoescape = false)
{
if ($autoescape && $string instanceof Markup) {
return $string;
}
if (!\is_string($string)) {
if (\is_object($string) && method_exists($string, '__toString')) {
if ($autoescape) {
$c = \get_class($string);
if (!isset($this->safeClasses[$c])) {
$this->safeClasses[$c] = [];
foreach (class_parents($string) + class_implements($string) as $class) {
if (isset($this->safeClasses[$class])) {
$this->safeClasses[$c] = array_unique(array_merge($this->safeClasses[$c], $this->safeClasses[$class]));
foreach ($this->safeClasses[$class] as $s) {
$this->safeLookup[$s][$c] = true;
}
}
}
}
if (isset($this->safeLookup[$strategy][$c]) || isset($this->safeLookup['all'][$c])) {
return (string) $string;
}
}
$string = (string) $string;
} elseif (\in_array($strategy, ['html', 'js', 'css', 'html_attr', 'url'])) {
// we return the input as is (which can be of any type)
return $string;
}
}
if ('' === $string) {
return '';
}
$charset = $charset ?: $this->charset;
switch ($strategy) {
case 'html':
// see https://www.php.net/htmlspecialchars
// Using a static variable to avoid initializing the array
// each time the function is called. Moving the declaration on the
// top of the function slow downs other escaping strategies.
static $htmlspecialcharsCharsets = [
'ISO-8859-1' => true, 'ISO8859-1' => true,
'ISO-8859-15' => true, 'ISO8859-15' => true,
'utf-8' => true, 'UTF-8' => true,
'CP866' => true, 'IBM866' => true, '866' => true,
'CP1251' => true, 'WINDOWS-1251' => true, 'WIN-1251' => true,
'1251' => true,
'CP1252' => true, 'WINDOWS-1252' => true, '1252' => true,
'KOI8-R' => true, 'KOI8-RU' => true, 'KOI8R' => true,
'BIG5' => true, '950' => true,
'GB2312' => true, '936' => true,
'BIG5-HKSCS' => true,
'SHIFT_JIS' => true, 'SJIS' => true, '932' => true,
'EUC-JP' => true, 'EUCJP' => true,
'ISO8859-5' => true, 'ISO-8859-5' => true, 'MACROMAN' => true,
];
if (isset($htmlspecialcharsCharsets[$charset])) {
return htmlspecialchars($string, \ENT_QUOTES | \ENT_SUBSTITUTE, $charset);
}
if (isset($htmlspecialcharsCharsets[strtoupper($charset)])) {
// cache the lowercase variant for future iterations
$htmlspecialcharsCharsets[$charset] = true;
return htmlspecialchars($string, \ENT_QUOTES | \ENT_SUBSTITUTE, $charset);
}
$string = $this->convertEncoding($string, 'UTF-8', $charset);
$string = htmlspecialchars($string, \ENT_QUOTES | \ENT_SUBSTITUTE, 'UTF-8');
return iconv('UTF-8', $charset, $string);
case 'js':
// escape all non-alphanumeric characters
// into their \x or \uHHHH representations
if ('UTF-8' !== $charset) {
$string = $this->convertEncoding($string, 'UTF-8', $charset);
}
if (!preg_match('//u', $string)) {
throw new RuntimeError('The string to escape is not a valid UTF-8 string.');
}
$string = preg_replace_callback('#[^a-zA-Z0-9,\._]#Su', function ($matches) {
$char = $matches[0];
/*
* A few characters have short escape sequences in JSON and JavaScript.
* Escape sequences supported only by JavaScript, not JSON, are omitted.
* \" is also supported but omitted, because the resulting string is not HTML safe.
*/
static $shortMap = [
'\\' => '\\\\',
'/' => '\\/',
"\x08" => '\b',
"\x0C" => '\f',
"\x0A" => '\n',
"\x0D" => '\r',
"\x09" => '\t',
];
if (isset($shortMap[$char])) {
return $shortMap[$char];
}
$codepoint = mb_ord($char, 'UTF-8');
if (0x10000 > $codepoint) {
return sprintf('\u%04X', $codepoint);
}
// Split characters outside the BMP into surrogate pairs
// https://tools.ietf.org/html/rfc2781.html#section-2.1
$u = $codepoint - 0x10000;
$high = 0xD800 | ($u >> 10);
$low = 0xDC00 | ($u & 0x3FF);
return sprintf('\u%04X\u%04X', $high, $low);
}, $string);
if ('UTF-8' !== $charset) {
$string = iconv('UTF-8', $charset, $string);
}
return $string;
case 'css':
if ('UTF-8' !== $charset) {
$string = $this->convertEncoding($string, 'UTF-8', $charset);
}
if (!preg_match('//u', $string)) {
throw new RuntimeError('The string to escape is not a valid UTF-8 string.');
}
$string = preg_replace_callback('#[^a-zA-Z0-9]#Su', function ($matches) {
$char = $matches[0];
return sprintf('\\%X ', 1 === \strlen($char) ? \ord($char) : mb_ord($char, 'UTF-8'));
}, $string);
if ('UTF-8' !== $charset) {
$string = iconv('UTF-8', $charset, $string);
}
return $string;
case 'html_attr':
if ('UTF-8' !== $charset) {
$string = $this->convertEncoding($string, 'UTF-8', $charset);
}
if (!preg_match('//u', $string)) {
throw new RuntimeError('The string to escape is not a valid UTF-8 string.');
}
$string = preg_replace_callback('#[^a-zA-Z0-9,\.\-_]#Su', function ($matches) {
/**
* This function is adapted from code coming from Zend Framework.
*
* @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (https://www.zend.com)
* @license https://framework.zend.com/license/new-bsd New BSD License
*/
$chr = $matches[0];
$ord = \ord($chr);
/*
* The following replaces characters undefined in HTML with the
* hex entity for the Unicode replacement character.
*/
if (($ord <= 0x1F && "\t" != $chr && "\n" != $chr && "\r" != $chr) || ($ord >= 0x7F && $ord <= 0x9F)) {
return '&#xFFFD;';
}
/*
* Check if the current character to escape has a name entity we should
* replace it with while grabbing the hex value of the character.
*/
if (1 === \strlen($chr)) {
/*
* While HTML supports far more named entities, the lowest common denominator
* has become HTML5's XML Serialisation which is restricted to the those named
* entities that XML supports. Using HTML entities would result in this error:
* XML Parsing Error: undefined entity
*/
static $entityMap = [
34 => '&quot;', /* quotation mark */
38 => '&amp;', /* ampersand */
60 => '&lt;', /* less-than sign */
62 => '&gt;', /* greater-than sign */
];
if (isset($entityMap[$ord])) {
return $entityMap[$ord];
}
return sprintf('&#x%02X;', $ord);
}
/*
* Per OWASP recommendations, we'll use hex entities for any other
* characters where a named entity does not exist.
*/
return sprintf('&#x%04X;', mb_ord($chr, 'UTF-8'));
}, $string);
if ('UTF-8' !== $charset) {
$string = iconv('UTF-8', $charset, $string);
}
return $string;
case 'url':
return rawurlencode($string);
default:
if (\array_key_exists($strategy, $this->escapers)) {
return $this->escapers[$strategy]($string, $charset);
}
$validStrategies = implode('", "', array_merge(['html', 'js', 'url', 'css', 'html_attr'], array_keys($this->escapers)));
throw new RuntimeError(sprintf('Invalid escaping strategy "%s" (valid ones: "%s").', $strategy, $validStrategies));
}
}
private function convertEncoding(string $string, string $to, string $from)
{
if (!\function_exists('iconv')) {
throw new RuntimeError('Unable to convert encoding: required function iconv() does not exist. You should install ext-iconv or symfony/polyfill-iconv.');
}
return iconv($from, $to, $string);
}
}