摇曳的蔷薇
docx是 Microsoft Word Open XML 格式文档，它是一种基于 XML 的文件，所有内容都存储为单独的文件，并最终压缩为一个 ZIP 压缩文件。它看起来像一个文件容器。并且我们不应该将文件扩展名与 mimetype 相同。据了解，具有docx文件扩展名的正常（带有 docx 的 mp4 文件不应视为正常）文件可以具有这些 mimetypes 之一。'application/vnd.openxmlformats-officedocument.wordprocessingml.document''application/zip''application/CDFV2'在您的代码中，$file->getClientOriginalExtension() extract extension from the original file name that was uploaded which should not be considered as a safe value.$file->getClientMimeType() extract the mime type from client request which should not be considered as a safe value.Both these two functin implemented in ./vendor/symfony/http-foundation/File/UploadedFile.phpThen take a look at last function in your code,$file->extension() use some method to guess (which maybe not accurate) the file extension. In sequence php's finfo (manual) which base on the file content, the system file. As the below source code it's guess, so it's not accurate all the time. Refer to file command apparently returning wrong MIME type.Here you should get it. If you want to go further, see below source code of the function extension.Source Codeextension call guessExtension to guess the file extension, and guessExtension use the mimetype returned by guessMiMeType// FileHelpers.phppublic function extension(){ return $this->guessExtension();}// File.phppublic function guessExtension(){ return MimeTypes::getDefault()->getExtensions($this->getMimeType())[0] ?? null;}...public function getMimeType(){ return MimeTypes::getDefault()->guessMimeType($this->getPathname());}guessMiMeType use two guesser to guess the mimetype. php's finfo and system's file, and finfo take high priority than file.//MimeTypes.phppublic function __construct(array $map = []){ foreach ($map as $mimeType => $extensions) { $this->extensions[$mimeType] = $extensions; foreach ($extensions as $extension) { $this->mimeTypes[$extension] = $mimeType; } } $this->registerGuesser(new FileBinaryMimeTypeGuesser()); $this->registerGuesser(new FileinfoMimeTypeGuesser());}.../*** Registers a MIME type guesser.** The last registered guesser has precedence over the other ones.*/public function registerGuesser(MimeTypeGuesserInterface $guesser){ array_unshift($this->guessers, $guesser);}...public function guessMimeType(string $path): ?string{ foreach ($this->guessers as $guesser) { if (!$guesser->isGuesserSupported()) { continue; } if (null !== $mimeType = $guesser->guessMimeType($path)) { return $mimeType; } } if (!$this->isGuesserSupported()) { throw new LogicException('Unable to guess the MIME type as no guessers are available (have you enable the php_fileinfo extension?).'); } return null;}//FileinfoMimeTypeGuesser.phppublic function guessMimeType(string $path): ?string{ if (!is_file($path) || !is_readable($path)) { throw new InvalidArgumentException(sprintf('The "%s" file does not exist or is not readable.', $path)); } if (!$this->isGuesserSupported()) { throw new LogicException(sprintf('The "%s" guesser is not supported.', __CLASS__)); } if (false === $finfo = new \finfo(FILEINFO_MIME_TYPE, $this->magicFile)) { return null; } return $finfo->file($path);}//FileBianryMimeTypeGuesser.phppublic function __construct(string $cmd = 'file -b --mime %s 2>/dev/null'){ $this->cmd = $cmd;} public function guessMimeType(string $path): ?string{ if (!is_file($path) || !is_readable($path)) { throw new InvalidArgumentException(sprintf('The "%s" file does not exist or is not readable.', $path)); } if (!$this->isGuesserSupported()) { throw new LogicException(sprintf('The "%s" guesser is not supported.', __CLASS__)); } ob_start(); // need to use --mime instead of -i. see #6641 passthru(sprintf($this->cmd, escapeshellarg($path)), $return); if ($return > 0) { ob_end_clean(); return null; } $type = trim(ob_get_clean()); if (!preg_match('#^([a-z0-9\-]+/[a-z0-9\-\.]+)#i', $type, $match)) { // it's not a type, but an error message return null; } return $match[1];}