How to set up download authentication? - authentication

Question

I am looking for some sort of download authentication. I am going to give a user a link to a file, and I want to make sure only that person will get it only once. Is there a simple solution without setting up a database?
Even better: if it's possible to have an encrypted web link that will let you download a file from my FTP server just once, after that the link becomes invalid.

Answer 1

You can use simple php script. This script returing inputet in GET file on the brower.
After his excecution you can rename this file to random string.
this only first person download this file.
Your link get somethis like this. www.domain.tld/dir/script.php?file=./usr/123.tar.gz.
You can filename encrypt in base64 too, in this option your link is www.domain.tld/dir/script.php?file=Li91c3IvMTIzLnRhci5neg==
Script without base64:
<?php
$file = $_GET['file'];
if (file_exists($file)) {
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
ob_clean();
flush();
readfile($file);
rename($file, "secret_new_filename");
exit;
}
else
{
echo 'File don\'t exist';
}
?>
And with base64:
<?php
$file = base64_decode($_GET['file']);
if (file_exists($file)) {
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename='.basename($file));
header('Content-Transfer-Encoding: binary');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
header('Content-Length: ' . filesize($file));
ob_clean();
flush();
readfile($file);
rename($file, "secret_new_filename");
exit;
}
else
{
echo 'File don\'t exist';
}
?>