avoid hotlinking in downloads

[edu]

I need a captcha system to avoid hotlinking in downloads , anybody can download (externally) any image with:

www.mydomain.com/download.php?image_id=345   or   www.mydomain.com/download.php?action=zip&image_id=345

Somebody can help me ?

Thanks.

[V@no]

Lets try this:
in includes/functions.php find:

Code: [Select]

    $download_zip_button = ($target == "" && function_exists("gzcompress") && function_exists("crc32")) ? "<a href=\"".$site_sess->url(ROOT_PATH."download.php?action=zip&amp;".URL_IMAGE_ID."=".$image_row['image_id'])."\"".$target."><img src=\"".get_gallery_image("download_zip.gif")."\" border=\"0\" alt=\"\" /></a>" : "";
Insert below:

Code: [Select]

    $site_sess->set_session_var("download_auth", time());

Then in download.php find:

Code: [Select]

elseif ($image_id) {
Insert below:

Code: [Select]

  if (!$site_sess->get_session_var('download_auth'))
  {
    if (!function_exists("redirect")) { function redirect($url) { header("Location: ".$url); exit;}}
    redirect($url);
  }
  $site_sess->drop_session_var('download_auth');

Now, in order to download a single image, you must first visit the site. If one tryed to hotlink the download link, it will simply redirect to your site.

P.S. this should work with all 4images versions.

[edu]

Thank you V@no !!, It work perfectly.

I would like to force the user to visit the image before he would can download it; is possible ?

[V@no]

replase

Code: [Select]

    redirect($url);
with

Code: [Select]

    redirect($site_sess->url(ROOT_PATH."details.php?image_id=".$image_id, "&"));


[kief24]

works great, thx a lot !