Question

User uploads files, lets say image files on the remote server.
For example if user1 uploads an image to this path

http://somedomain.com/uploads/123.jpg

And I display image on the web page for the logged in user using the above url.
Suppose the user logs out. and some user come to know about the above url and he can access the image. How can I prevent this?

Answer 1

I will just demonstrate an idea for you. Then you can search in more detail for a solution. There are many solutions, many of them complicated, so it depends on how far you are willing to go. I think this one is a pretty simple solution (depends on your programming skills of course). So,

1. User clicks the link http://somedomain.com/uploads/123.jpg to open the image.
2. You have an htaccess file, that will take that url and do a conversion (behind the scenes).
3. That htaccess file will actually call, for example, the images.php file.
4. images.php file will get the name of the image and will check if a user is logged in or not.
5. If user is logged in, it will grub the image file with name, let’s say, up-image-123.jpg
6. The htaccess file will do the conversion again and instead of revealing the real name up-image-123.jpg, will reveal the 123.jpg (which is not a real file name for someone else to access)