Is it possible to remove a Password from a PDF file using PHP?

I would like to ask if it’s possible to use PHP in removing a password from a password-protected PDF file in which I already know the password? I’ve seen this page which provides many options but using bash script. 🙁 I was required to use PHP as much as possible. Any suggestions appreciated!

Answer

Of course it’s possible, all you need to do is reverse engineer the encryption and compression and implement the reverse operations in PHP – but why bother:

<?php
   `gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=unencrypted.pdf -c .setpdfwrite -f encrypted.pdf`;
?>

C.