确保用户定义的路径在PHP中是安全的

I am implementing a simple directory listing script in PHP.

我在PHP中实现了一个简单的目录列表脚本。

I want to ensure that the passed path is safe before opening directory handles and echoing the results willy-nilly.

我想确保传递的路径是安全的,然后打开目录句柄并不断回应结果。

$f = $_GET["f"];
if(! $f) {
    $f = "/";
}
// make sure $f is safe
$farr = explode("/",$f);
$unsafe = false;
foreach($farr as $farre) {
    // protect against directory traversal
    if(strpos($farre,"..") != false) {
        $unsafe = true;
        break;
    }
    if(end($farr) != $farre) {
        // make sure no dots are present (except after the last slash in the file path)
        if(strpos($farre,".") != false) {
            $unsafe = true;
            break;
        }
    }
}

Is this enough to make sure a path sent by the user is safe, or are there other things I should do to protected against attack?

这是否足以确保用户发送的路径是安全的,还是我应该采取其他措施来防止攻击?

1 个解决方案

#1

It may be that realpath() is helpful to you.

可能是realpath()对你有帮助。

realpath() expands all symbolic links and resolves references to '/./', '/../' and extra '/' characters in the input path, and returns the canonicalized absolute pathname.

realpath()展开所有符号链接并解析对输入路径中'/./','/../'和额外'/'字符的引用,并返回规范化的绝对路径名。

However, this function assumes that the path in question actually exists. It will not perform canonization for a non-existing path. In this case FALSE is returned.

但是,此函数假定所讨论的路径实际存在。它不会对不存在的路径执行canonization。在这种情况下,返回FALSE。

#1