New Feature for private downloads

Hi Guys !

I noticed that the private download funktion has two disantvantages:
- Downloadmanagers can´t resume or use more than one download stream
- with filesizes above the memory_max_limit of php interpreter we can´t work (i have to download big files often (over 500mb)

So i implemented a new way to download files.
"Security through obscurity" - like it is working as following:

1. we have a private directory with no public access through apache.
2. if someone want to download a file - a directory would be created in the temporary directory of drupal. After that a link from the original file in this folder is created.
3. per header location the visitor is redirected to this link (every Downloadmanager can now work with this link very fine.
4. to get no permanent links this directories and links needs to removed after a certain time)

The advantages of this method are:
- we can use download managers
- the downloads are protected because the links are not permanent (living time only a certain time, we can configure by ourself)
- if you want to give a friend access to just one file without making an account for him you can send him this non permanent links.

I have attached a in my opinion very small and not too complicated patch. it is working with the current rc10 Version of drupal6.

Done:
- Changed Checkbox "private downloads" to a select box where we can choose between "none","private" and "obscurity".
- Implemented the new obscurity download

ToDo:
- deleting directories and links in temporary directory after a certain time via a cron job of the module (after 300minutes or so)

Workarround for the ToDo:
a simple find commando in linux cron with -exec rm {} \;

would be great if we can use this feature in future versions. Any wishes or tips or critism or reviews are very welcome.

Greetings from Germany, Dresden

Robert Bude