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我的问题很简单。我不应该让用户上传图像,而是从源代码创建图像时,是否应该在验证中进行彻底检查?使用PHP上传图片与从上传图片创建图片时的验证过程
我在想,我只会用$_FILES['file']['tmp_name']
用PHP创建功能的新的JPEG或PNG图像。
在php.net,我发现这个建议得票最多,我应该做这样还是矫枉过正?
try {
// Undefined | Multiple Files | $_FILES Corruption Attack
// If this request falls under any of them, treat it invalid.
if (
!isset($_FILES['upfile']['error']) ||
is_array($_FILES['upfile']['error'])
) {
throw new RuntimeException('Invalid parameters.');
}
// Check $_FILES['upfile']['error'] value.
switch ($_FILES['upfile']['error']) {
case UPLOAD_ERR_OK:
break;
case UPLOAD_ERR_NO_FILE:
throw new RuntimeException('No file sent.');
case UPLOAD_ERR_INI_SIZE:
case UPLOAD_ERR_FORM_SIZE:
throw new RuntimeException('Exceeded filesize limit.');
default:
throw new RuntimeException('Unknown errors.');
}
// You should also check filesize here.
if ($_FILES['upfile']['size'] > 1000000) {
throw new RuntimeException('Exceeded filesize limit.');
}
// DO NOT TRUST $_FILES['upfile']['mime'] VALUE !!
// Check MIME Type by yourself.
$finfo = new finfo(FILEINFO_MIME_TYPE);
if (false === $ext = array_search(
$finfo->file($_FILES['upfile']['tmp_name']),
array(
'jpg' => 'image/jpeg',
'png' => 'image/png',
'gif' => 'image/gif',
),
true
)) {
throw new RuntimeException('Invalid file format.');
}
// You should name it uniquely.
// DO NOT USE $_FILES['upfile']['name'] WITHOUT ANY VALIDATION !!
// On this example, obtain safe unique name from its binary data.
if (!move_uploaded_file(
$_FILES['upfile']['tmp_name'],
sprintf('./uploads/%s.%s',
sha1_file($_FILES['upfile']['tmp_name']),
$ext
)
)) {
throw new RuntimeException('Failed to move uploaded file.');
}
echo 'File is uploaded successfully.';
} catch (RuntimeException $e) {
echo $e->getMessage();
}
感谢您的回答。但它似乎在这里不同意你的答案:http://stackoverflow.com/questions/15595592/php-validating-the-file-upload。 “唯一可靠的图像验证方法是使用GD或Imagick制作它的副本”因此,您不应让用户上传图像以节省资源。或者我错了? – Alex