Controller::processActionDownloadFile

protected function processActionDownloadFile(): void
{
	$this->checkRequiredGetParams(['attachedId']);

	if ($this->errorCollection->hasErrors())
	{
		$this->sendJsonErrorResponse();
	}

	[$type, $realValue] = FileUserType::detectType($this->request->getQuery('attachedId'));
	if ($type === FileUserType::TYPE_NEW_OBJECT)
	{
		$fileModel = File::loadById((int)$realValue, ['STORAGE']);
		if (!$fileModel)
		{
			$this->addError(new Error('Could not find file'));
			$this->sendJsonErrorResponse();
		}
		if (!$fileModel->canRead($fileModel->getStorage()->getCurrentUserSecurityContext()))
		{
			$this->addError(new Error("Bad permission. Could not read this file"));
			$this->sendJsonErrorResponse();
		}

		$fileName = $fileModel->getName();
		$fileData = $fileModel->getFile();

		if (!$fileData)
		{
			$this->end();
		}

		$cacheTime = 0;

		$width = (int)$this->request->getQuery('width');
		$height = (int)$this->request->getQuery('height');
		$isImage = TypeFile::isImage($fileData['ORIGINAL_NAME']) || TypeFile::isImage($fileName);
		$isImage = $isImage && !TypeFile::shouldTreatImageAsFile($fileData);
		if ($isImage && ($width > 0 || $height > 0))
		{
			$signature = $this->request->getQuery('signature');
			if (!$signature)
			{
				$this->sendJsonInvalidSignResponse('Empty signature');
			}
			if (!ParameterSigner::validateImageSignature($signature, $fileModel->getId(), $width, $height))
			{
				$this->sendJsonInvalidSignResponse('Invalid signature');
			}

			$resizeType = $this->request->getQuery('exact') === 'Y' ? BX_RESIZE_IMAGE_EXACT : BX_RESIZE_IMAGE_PROPORTIONAL;
			$tmpFile = CFile::resizeImageGet($fileData, ['width' => $width, 'height' => $height], $resizeType, true, false, true);
			$fileData['FILE_SIZE'] = $tmpFile['size'];
			$fileData['SRC'] = $tmpFile['src'];
			$cacheTime = 86400;
		}
		CFile::viewByUser($fileData, ['force_download' => false, 'cache_time' => $cacheTime, 'attachment_name' => $fileName]);
	}
	else
	{
		$this->addError(new Error('Could not find attached object'));
		$this->sendJsonErrorResponse();
	}
}