CodeIgniter - 用户应该只能访问自己的图像

Question

I am currently trying to develop an image uploading website by using CodeIgniter. The thing is, I came across an issue today and I would really appreciate any kind of help in order to solve it.

So basically, the site is working. But the thing is, that the files are not private. A user may want to ensure that the files the users upload are only visible by them, and not by someone who just guesses a bunch of urls. (eg. user1 uploads image1 which he wants to keep private, for himself =>[localhostlocalhost/upload_script/files/image1.jpg], user2 can access image1 by guessing and typing the url [localhost/upload_script/files/image1.jpg] which is what we don't want to happen. ) I have done some research and I think that this would probably require another controller for serving the files (which checks for session data). I have been "playing" with sessions etc in PHP for quite some time in the past, but I am not that familiar with them in CodeIgniter. Is this the only way? I don't think I need to create separate directories for each user, do I? Can you please tell me how to head to the right direction or give me an example?

Thanks in advance,

harris21

Answer 1

In order to protect files, you will need keep them outside of your web root, otherwise people will always be able to url hack their way round.

I have used the very handy mod_xsendfile for apache (if you have that kind of access to your server) which will allow you to serve files that can be protected by access control and not accessed without the appropriate credentials.

Code snippet that you could put in your CI controller to display an image (adapted from the mod_xsendfile page):

...
if ($user->isLoggedIn())
{
    header("X-Sendfile: $path_to_somefile");
    header('Content-Type: image/jpeg');
    exit;
}

If you cannot install mod_xsendfile then your only other option would be to use readfile() as TheShiftExchange says.