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Direktori : /home/silvzytp/ccd-ind-code/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Security/ |
Current File : //home/silvzytp/ccd-ind-code/vendor/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Reader/Security/XmlScanner.php |
<?php namespace PhpOffice\PhpSpreadsheet\Reader\Security; use PhpOffice\PhpSpreadsheet\Reader; class XmlScanner { /** * String used to identify risky xml elements. * * @var string */ private $pattern; /** @var ?callable */ private $callback; /** @var ?bool */ private static $libxmlDisableEntityLoaderValue; /** * @var bool */ private static $shutdownRegistered = false; public function __construct(string $pattern = '<!DOCTYPE') { $this->pattern = $pattern; $this->disableEntityLoaderCheck(); // A fatal error will bypass the destructor, so we register a shutdown here if (!self::$shutdownRegistered) { self::$shutdownRegistered = true; register_shutdown_function([__CLASS__, 'shutdown']); } } public static function getInstance(Reader\IReader $reader): self { $pattern = ($reader instanceof Reader\Html) ? '<!ENTITY' : '<!DOCTYPE'; return new self($pattern); } /** * @codeCoverageIgnore */ public static function threadSafeLibxmlDisableEntityLoaderAvailability(): bool { if (PHP_MAJOR_VERSION === 7) { switch (PHP_MINOR_VERSION) { case 2: return PHP_RELEASE_VERSION >= 1; case 1: return PHP_RELEASE_VERSION >= 13; case 0: return PHP_RELEASE_VERSION >= 27; } return true; } return false; } /** * @codeCoverageIgnore */ private function disableEntityLoaderCheck(): void { if (\PHP_VERSION_ID < 80000) { $libxmlDisableEntityLoaderValue = libxml_disable_entity_loader(true); if (self::$libxmlDisableEntityLoaderValue === null) { self::$libxmlDisableEntityLoaderValue = $libxmlDisableEntityLoaderValue; } } } /** * @codeCoverageIgnore */ public static function shutdown(): void { if (self::$libxmlDisableEntityLoaderValue !== null && \PHP_VERSION_ID < 80000) { libxml_disable_entity_loader(self::$libxmlDisableEntityLoaderValue); self::$libxmlDisableEntityLoaderValue = null; } } public function __destruct() { self::shutdown(); } public function setAdditionalCallback(callable $callback): void { $this->callback = $callback; } /** @param mixed $arg */ private static function forceString($arg): string { return is_string($arg) ? $arg : ''; } /** * @param string $xml * * @return string */ private function toUtf8($xml) { $pattern = '/encoding="(.*?)"/'; $result = preg_match($pattern, $xml, $matches); $charset = strtoupper($result ? $matches[1] : 'UTF-8'); if ($charset !== 'UTF-8') { $xml = self::forceString(mb_convert_encoding($xml, 'UTF-8', $charset)); $result = preg_match($pattern, $xml, $matches); $charset = strtoupper($result ? $matches[1] : 'UTF-8'); if ($charset !== 'UTF-8') { throw new Reader\Exception('Suspicious Double-encoded XML, spreadsheet file load() aborted to prevent XXE/XEE attacks'); } } return $xml; } /** * Scan the XML for use of <!ENTITY to prevent XXE/XEE attacks. * * @param false|string $xml * * @return string */ public function scan($xml) { $xml = "$xml"; $this->disableEntityLoaderCheck(); $xml = $this->toUtf8($xml); // Don't rely purely on libxml_disable_entity_loader() $pattern = '/\\0?' . implode('\\0?', /** @scrutinizer ignore-type */ str_split($this->pattern)) . '\\0?/'; if (preg_match($pattern, $xml)) { throw new Reader\Exception('Detected use of ENTITY in XML, spreadsheet file load() aborted to prevent XXE/XEE attacks'); } if ($this->callback !== null && is_callable($this->callback)) { $xml = call_user_func($this->callback, $xml); } return $xml; } /** * Scan theXML for use of <!ENTITY to prevent XXE/XEE attacks. * * @param string $filestream * * @return string */ public function scanFile($filestream) { return $this->scan(file_get_contents($filestream)); } }