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\Extension { 13use Twig\FileExtensionEscapingStrategy; 14use Twig\NodeVisitor\EscaperNodeVisitor; 15use Twig\TokenParser\AutoEscapeTokenParser; 16use Twig\TwigFilter; 17 18final class EscaperExtension extends AbstractExtension 19{ 20 private $defaultStrategy; 21 private $escapers = []; 22 23 /** @internal */ 24 public $safeClasses = []; 25 26 /** @internal */ 27 public $safeLookup = []; 28 29 /** 30 * @param string|false|callable $defaultStrategy An escaping strategy 31 * 32 * @see setDefaultStrategy() 33 */ 34 public function __construct($defaultStrategy = 'html') 35 { 36 $this->setDefaultStrategy($defaultStrategy); 37 } 38 39 public function getTokenParsers() 40 { 41 return [new AutoEscapeTokenParser()]; 42 } 43 44 public function getNodeVisitors() 45 { 46 return [new EscaperNodeVisitor()]; 47 } 48 49 public function getFilters() 50 { 51 return [ 52 new TwigFilter('escape', 'twig_escape_filter', ['needs_environment' => true, 'is_safe_callback' => 'twig_escape_filter_is_safe']), 53 new TwigFilter('e', 'twig_escape_filter', ['needs_environment' => true, 'is_safe_callback' => 'twig_escape_filter_is_safe']), 54 new TwigFilter('raw', 'twig_raw_filter', ['is_safe' => ['all']]), 55 ]; 56 } 57 58 /** 59 * Sets the default strategy to use when not defined by the user. 60 * 61 * The strategy can be a valid PHP callback that takes the template 62 * name as an argument and returns the strategy to use. 63 * 64 * @param string|false|callable $defaultStrategy An escaping strategy 65 */ 66 public function setDefaultStrategy($defaultStrategy) 67 { 68 if ('name' === $defaultStrategy) { 69 $defaultStrategy = [FileExtensionEscapingStrategy::class, 'guess']; 70 } 71 72 $this->defaultStrategy = $defaultStrategy; 73 } 74 75 /** 76 * Gets the default strategy to use when not defined by the user. 77 * 78 * @param string $name The template name 79 * 80 * @return string|false The default strategy to use for the template 81 */ 82 public function getDefaultStrategy($name) 83 { 84 // disable string callables to avoid calling a function named html or js, 85 // or any other upcoming escaping strategy 86 if (!\is_string($this->defaultStrategy) && false !== $this->defaultStrategy) { 87 return \call_user_func($this->defaultStrategy, $name); 88 } 89 90 return $this->defaultStrategy; 91 } 92 93 /** 94 * Defines a new escaper to be used via the escape filter. 95 * 96 * @param string $strategy The strategy name that should be used as a strategy in the escape call 97 * @param callable $callable A valid PHP callable 98 */ 99 public function setEscaper($strategy, callable $callable) 100 { 101 $this->escapers[$strategy] = $callable; 102 } 103 104 /** 105 * Gets all defined escapers. 106 * 107 * @return callable[] An array of escapers 108 */ 109 public function getEscapers() 110 { 111 return $this->escapers; 112 } 113 114 public function setSafeClasses(array $safeClasses = []) 115 { 116 $this->safeClasses = []; 117 $this->safeLookup = []; 118 foreach ($safeClasses as $class => $strategies) { 119 $this->addSafeClass($class, $strategies); 120 } 121 } 122 123 public function addSafeClass(string $class, array $strategies) 124 { 125 $class = ltrim($class, '\\'); 126 if (!isset($this->safeClasses[$class])) { 127 $this->safeClasses[$class] = []; 128 } 129 $this->safeClasses[$class] = array_merge($this->safeClasses[$class], $strategies); 130 131 foreach ($strategies as $strategy) { 132 $this->safeLookup[$strategy][$class] = true; 133 } 134 } 135} 136 137class_alias('Twig\Extension\EscaperExtension', 'Twig_Extension_Escaper'); 138} 139 140namespace { 141use Twig\Environment; 142use Twig\Error\RuntimeError; 143use Twig\Extension\CoreExtension; 144use Twig\Extension\EscaperExtension; 145use Twig\Markup; 146use Twig\Node\Expression\ConstantExpression; 147use Twig\Node\Node; 148 149/** 150 * Marks a variable as being safe. 151 * 152 * @param string $string A PHP variable 153 * 154 * @return string 155 */ 156function twig_raw_filter($string) 157{ 158 return $string; 159} 160 161/** 162 * Escapes a string. 163 * 164 * @param mixed $string The value to be escaped 165 * @param string $strategy The escaping strategy 166 * @param string $charset The charset 167 * @param bool $autoescape Whether the function is called by the auto-escaping feature (true) or by the developer (false) 168 * 169 * @return string 170 */ 171function twig_escape_filter(Environment $env, $string, $strategy = 'html', $charset = null, $autoescape = false) 172{ 173 if ($autoescape && $string instanceof Markup) { 174 return $string; 175 } 176 177 if (!\is_string($string)) { 178 if (\is_object($string) && method_exists($string, '__toString')) { 179 if ($autoescape) { 180 $c = \get_class($string); 181 $ext = $env->getExtension(EscaperExtension::class); 182 if (!isset($ext->safeClasses[$c])) { 183 $ext->safeClasses[$c] = []; 184 foreach (class_parents($string) + class_implements($string) as $class) { 185 if (isset($ext->safeClasses[$class])) { 186 $ext->safeClasses[$c] = array_unique(array_merge($ext->safeClasses[$c], $ext->safeClasses[$class])); 187 foreach ($ext->safeClasses[$class] as $s) { 188 $ext->safeLookup[$s][$c] = true; 189 } 190 } 191 } 192 } 193 if (isset($ext->safeLookup[$strategy][$c]) || isset($ext->safeLookup['all'][$c])) { 194 return (string) $string; 195 } 196 } 197 198 $string = (string) $string; 199 } elseif (\in_array($strategy, ['html', 'js', 'css', 'html_attr', 'url'])) { 200 return $string; 201 } 202 } 203 204 if ('' === $string) { 205 return ''; 206 } 207 208 if (null === $charset) { 209 $charset = $env->getCharset(); 210 } 211 212 switch ($strategy) { 213 case 'html': 214 // see https://www.php.net/htmlspecialchars 215 216 // Using a static variable to avoid initializing the array 217 // each time the function is called. Moving the declaration on the 218 // top of the function slow downs other escaping strategies. 219 static $htmlspecialcharsCharsets = [ 220 'ISO-8859-1' => true, 'ISO8859-1' => true, 221 'ISO-8859-15' => true, 'ISO8859-15' => true, 222 'utf-8' => true, 'UTF-8' => true, 223 'CP866' => true, 'IBM866' => true, '866' => true, 224 'CP1251' => true, 'WINDOWS-1251' => true, 'WIN-1251' => true, 225 '1251' => true, 226 'CP1252' => true, 'WINDOWS-1252' => true, '1252' => true, 227 'KOI8-R' => true, 'KOI8-RU' => true, 'KOI8R' => true, 228 'BIG5' => true, '950' => true, 229 'GB2312' => true, '936' => true, 230 'BIG5-HKSCS' => true, 231 'SHIFT_JIS' => true, 'SJIS' => true, '932' => true, 232 'EUC-JP' => true, 'EUCJP' => true, 233 'ISO8859-5' => true, 'ISO-8859-5' => true, 'MACROMAN' => true, 234 ]; 235 236 if (isset($htmlspecialcharsCharsets[$charset])) { 237 return htmlspecialchars($string, \ENT_QUOTES | \ENT_SUBSTITUTE, $charset); 238 } 239 240 if (isset($htmlspecialcharsCharsets[strtoupper($charset)])) { 241 // cache the lowercase variant for future iterations 242 $htmlspecialcharsCharsets[$charset] = true; 243 244 return htmlspecialchars($string, \ENT_QUOTES | \ENT_SUBSTITUTE, $charset); 245 } 246 247 $string = twig_convert_encoding($string, 'UTF-8', $charset); 248 $string = htmlspecialchars($string, \ENT_QUOTES | \ENT_SUBSTITUTE, 'UTF-8'); 249 250 return iconv('UTF-8', $charset, $string); 251 252 case 'js': 253 // escape all non-alphanumeric characters 254 // into their \x or \uHHHH representations 255 if ('UTF-8' !== $charset) { 256 $string = twig_convert_encoding($string, 'UTF-8', $charset); 257 } 258 259 if (!preg_match('//u', $string)) { 260 throw new RuntimeError('The string to escape is not a valid UTF-8 string.'); 261 } 262 263 $string = preg_replace_callback('#[^a-zA-Z0-9,\._]#Su', function ($matches) { 264 $char = $matches[0]; 265 266 /* 267 * A few characters have short escape sequences in JSON and JavaScript. 268 * Escape sequences supported only by JavaScript, not JSON, are omitted. 269 * \" is also supported but omitted, because the resulting string is not HTML safe. 270 */ 271 static $shortMap = [ 272 '\\' => '\\\\', 273 '/' => '\\/', 274 "\x08" => '\b', 275 "\x0C" => '\f', 276 "\x0A" => '\n', 277 "\x0D" => '\r', 278 "\x09" => '\t', 279 ]; 280 281 if (isset($shortMap[$char])) { 282 return $shortMap[$char]; 283 } 284 285 $codepoint = mb_ord($char, 'UTF-8'); 286 if (0x10000 > $codepoint) { 287 return sprintf('\u%04X', $codepoint); 288 } 289 290 // Split characters outside the BMP into surrogate pairs 291 // https://tools.ietf.org/html/rfc2781.html#section-2.1 292 $u = $codepoint - 0x10000; 293 $high = 0xD800 | ($u >> 10); 294 $low = 0xDC00 | ($u & 0x3FF); 295 296 return sprintf('\u%04X\u%04X', $high, $low); 297 }, $string); 298 299 if ('UTF-8' !== $charset) { 300 $string = iconv('UTF-8', $charset, $string); 301 } 302 303 return $string; 304 305 case 'css': 306 if ('UTF-8' !== $charset) { 307 $string = twig_convert_encoding($string, 'UTF-8', $charset); 308 } 309 310 if (!preg_match('//u', $string)) { 311 throw new RuntimeError('The string to escape is not a valid UTF-8 string.'); 312 } 313 314 $string = preg_replace_callback('#[^a-zA-Z0-9]#Su', function ($matches) { 315 $char = $matches[0]; 316 317 return sprintf('\\%X ', 1 === \strlen($char) ? \ord($char) : mb_ord($char, 'UTF-8')); 318 }, $string); 319 320 if ('UTF-8' !== $charset) { 321 $string = iconv('UTF-8', $charset, $string); 322 } 323 324 return $string; 325 326 case 'html_attr': 327 if ('UTF-8' !== $charset) { 328 $string = twig_convert_encoding($string, 'UTF-8', $charset); 329 } 330 331 if (!preg_match('//u', $string)) { 332 throw new RuntimeError('The string to escape is not a valid UTF-8 string.'); 333 } 334 335 $string = preg_replace_callback('#[^a-zA-Z0-9,\.\-_]#Su', function ($matches) { 336 /** 337 * This function is adapted from code coming from Zend Framework. 338 * 339 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (https://www.zend.com) 340 * @license https://framework.zend.com/license/new-bsd New BSD License 341 */ 342 $chr = $matches[0]; 343 $ord = \ord($chr); 344 345 /* 346 * The following replaces characters undefined in HTML with the 347 * hex entity for the Unicode replacement character. 348 */ 349 if (($ord <= 0x1f && "\t" != $chr && "\n" != $chr && "\r" != $chr) || ($ord >= 0x7f && $ord <= 0x9f)) { 350 return '�'; 351 } 352 353 /* 354 * Check if the current character to escape has a name entity we should 355 * replace it with while grabbing the hex value of the character. 356 */ 357 if (1 === \strlen($chr)) { 358 /* 359 * While HTML supports far more named entities, the lowest common denominator 360 * has become HTML5's XML Serialisation which is restricted to the those named 361 * entities that XML supports. Using HTML entities would result in this error: 362 * XML Parsing Error: undefined entity 363 */ 364 static $entityMap = [ 365 34 => '"', /* quotation mark */ 366 38 => '&', /* ampersand */ 367 60 => '<', /* less-than sign */ 368 62 => '>', /* greater-than sign */ 369 ]; 370 371 if (isset($entityMap[$ord])) { 372 return $entityMap[$ord]; 373 } 374 375 return sprintf('&#x%02X;', $ord); 376 } 377 378 /* 379 * Per OWASP recommendations, we'll use hex entities for any other 380 * characters where a named entity does not exist. 381 */ 382 return sprintf('&#x%04X;', mb_ord($chr, 'UTF-8')); 383 }, $string); 384 385 if ('UTF-8' !== $charset) { 386 $string = iconv('UTF-8', $charset, $string); 387 } 388 389 return $string; 390 391 case 'url': 392 return rawurlencode($string); 393 394 default: 395 // check the ones set on CoreExtension for BC (to be removed in 3.0) 396 $legacyEscapers = $env->getExtension(CoreExtension::class)->getEscapers(false); 397 if (array_key_exists($strategy, $legacyEscapers)) { 398 return $legacyEscapers[$strategy]($env, $string, $charset); 399 } 400 401 $escapers = $env->getExtension(EscaperExtension::class)->getEscapers(); 402 if (array_key_exists($strategy, $escapers)) { 403 return $escapers[$strategy]($env, $string, $charset); 404 } 405 406 $escapers = array_merge($legacyEscapers, $escapers); 407 $validStrategies = implode(', ', array_merge(['html', 'js', 'url', 'css', 'html_attr'], array_keys($escapers))); 408 409 throw new RuntimeError(sprintf('Invalid escaping strategy "%s" (valid ones: %s).', $strategy, $validStrategies)); 410 } 411} 412 413/** 414 * @internal 415 */ 416function twig_escape_filter_is_safe(Node $filterArgs) 417{ 418 foreach ($filterArgs as $arg) { 419 if ($arg instanceof ConstantExpression) { 420 return [$arg->getAttribute('value')]; 421 } 422 423 return []; 424 } 425 426 return ['html']; 427} 428} 429