Viewing file:  EscaperExtension.php (14.04 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
<?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\Extension {
use Twig\FileExtensionEscapingStrategy;
use Twig\NodeVisitor\EscaperNodeVisitor;
use Twig\TokenParser\AutoEscapeTokenParser;
use Twig\TwigFilter;
final class EscaperExtension extends AbstractExtension
{
private $defaultStrategy;
private $escapers = [];
/** @internal */
public $safeClasses = [];
/** @internal */
public $safeLookup = [];
/**
* @param string|false|callable $defaultStrategy An escaping strategy
*
* @see setDefaultStrategy()
*/
public function __construct($defaultStrategy = 'html')
{
$this->setDefaultStrategy($defaultStrategy);
}
public function getTokenParsers(): array
{
return [new AutoEscapeTokenParser()];
}
public function getNodeVisitors(): array
{
return [new EscaperNodeVisitor()];
}
public function getFilters(): array
{
return [
new TwigFilter('escape', 'twig_escape_filter', ['needs_environment' => true, 'is_safe_callback' => 'twig_escape_filter_is_safe']),
new TwigFilter('e', 'twig_escape_filter', ['needs_environment' => true, 'is_safe_callback' => 'twig_escape_filter_is_safe']),
new TwigFilter('raw', 'twig_raw_filter', ['is_safe' => ['all']]),
];
}
/**
* Sets the default strategy to use when not defined by the user.
*
* The strategy can be a valid PHP callback that takes the template
* name as an argument and returns the strategy to use.
*
* @param string|false|callable $defaultStrategy An escaping strategy
*/
public function setDefaultStrategy($defaultStrategy): void
{
if ('name' === $defaultStrategy) {
$defaultStrategy = [FileExtensionEscapingStrategy::class, 'guess'];
}
$this->defaultStrategy = $defaultStrategy;
}
/**
* Gets the default strategy to use when not defined by the user.
*
* @param string $name The template name
*
* @return string|false The default strategy to use for the template
*/
public function getDefaultStrategy(string $name)
{
// disable string callables to avoid calling a function named html or js,
// or any other upcoming escaping strategy
if (!\is_string($this->defaultStrategy) && false !== $this->defaultStrategy) {
return \call_user_func($this->defaultStrategy, $name);
}
return $this->defaultStrategy;
}
/**
* 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 $callable A valid PHP callable
*/
public function setEscaper($strategy, callable $callable)
{
$this->escapers[$strategy] = $callable;
}
/**
* Gets all defined escapers.
*
* @return callable[] 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;
}
}
}
}
namespace {
use Twig\Environment;
use Twig\Error\RuntimeError;
use Twig\Extension\EscaperExtension;
use Twig\Markup;
use Twig\Node\Expression\ConstantExpression;
use Twig\Node\Node;
/**
* Marks a variable as being safe.
*
* @param string $string A PHP variable
*/
function twig_raw_filter($string)
{
return $string;
}
/**
* Escapes a string.
*
* @param mixed $string The value to be escaped
* @param string $strategy The escaping strategy
* @param string $charset The charset
* @param bool $autoescape Whether the function is called by the auto-escaping feature (true) or by the developer (false)
*
* @return string
*/
function twig_escape_filter(Environment $env, $string, $strategy = 'html', $charset = null, $autoescape = false)
{
if ($autoescape && $string instanceof Markup) {
return $string;
}
if (!\is_string($string)) {
if (\is_object($string) && method_exists($string, '__toString')) {
if ($autoescape) {
$c = \get_class($string);
$ext = $env->getExtension(EscaperExtension::class);
if (!isset($ext->safeClasses[$c])) {
$ext->safeClasses[$c] = [];
foreach (class_parents($string) + class_implements($string) as $class) {
if (isset($ext->safeClasses[$class])) {
$ext->safeClasses[$c] = array_unique(array_merge($ext->safeClasses[$c], $ext->safeClasses[$class]));
foreach ($ext->safeClasses[$class] as $s) {
$ext->safeLookup[$s][$c] = true;
}
}
}
}
if (isset($ext->safeLookup[$strategy][$c]) || isset($ext->safeLookup['all'][$c])) {
return (string) $string;
}
}
$string = (string) $string;
} elseif (\in_array($strategy, ['html', 'js', 'css', 'html_attr', 'url'])) {
return $string;
}
}
if ('' === $string) {
return '';
}
if (null === $charset) {
$charset = $env->getCharset();
}
switch ($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);
}
$string = twig_convert_encoding($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) {
$string = twig_convert_encoding($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) {
$string = twig_convert_encoding($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) {
$string = twig_convert_encoding($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 && $ord <= 0x9f)) {
return '�';
}
/*
* Check if the current character to escape has a name entity we should
* replace it with while grabbing the hex value of the character.
*/
if (1 === \strlen($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 $entityMap = [
34 => '"', /* quotation mark */
38 => '&', /* ampersand */
60 => '<', /* less-than sign */
62 => '>', /* greater-than sign */
];
if (isset($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:
static $escapers;
if (null === $escapers) {
$escapers = $env->getExtension(EscaperExtension::class)->getEscapers();
}
if (isset($escapers[$strategy])) {
return $escapers[$strategy]($env, $string, $charset);
}
$validStrategies = implode(', ', array_merge(['html', 'js', 'url', 'css', 'html_attr'], array_keys($escapers)));
throw new RuntimeError(sprintf('Invalid escaping strategy "%s" (valid ones: %s).', $strategy, $validStrategies));
}
}
/**
* @internal
*/
function twig_escape_filter_is_safe(Node $filterArgs)
{
foreach ($filterArgs as $arg) {
if ($arg instanceof ConstantExpression) {
return [$arg->getAttribute('value')];
}
return [];
}
return ['html'];
}
}
|