PHP Extension Requires Chilkat v11.7.0+

Password-Protect a PDF with AES-256 Encryption

See more PDF Protection Examples

Demonstrates the simplest way to encrypt a PDF so that it needs a password to open. The passwords come from the UserPassword and OwnerPassword properties, and Protection with the encrypt operation and an empty JSON uses the defaults: AES-256, everything encrypted, every permission granted. Protection only records the security the PDF will be saved with. Nothing is encrypted until WriteFile is called. PHP Extension

<?php

include("chilkat.php");

$success = false;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

//  The PDF used in this example is available at two_page_memo.pdf

$pdf = new CkPdf();
$success = $pdf->LoadFile('qa_data/pdf/two_page_memo.pdf');
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

//  The passwords are taken from these two properties at the time Protection is called.
//  The user password opens the PDF.  The owner password opens it too, and is the one needed
//  later to change or remove the protection.
$pdf->put_UserPassword('user-secret');
$pdf->put_OwnerPassword('owner-secret');

//  An empty JSON asks for the defaults: AES-256, everything encrypted, every permission granted.
$json = new CkJsonObject();
$jsonOut = new CkJsonObject();
$success = $pdf->Protection('encrypt',$json,$jsonOut);
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

//  Nothing has been encrypted yet.  "pending" describes the security the PDF will be saved with.
print 'algorithm: ' . $jsonOut->stringOf('pending.algorithm') . "\n";
print 'PDF version: ' . $jsonOut->stringOf('pending.pdfVersion') . "\n";
print 'password needed to open: ' . $jsonOut->BoolOf('pending.userPasswordRequired') . "\n";

//  Writing the file applies it.
$success = $pdf->WriteFile('qa_output/memo_encrypted.pdf');
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

//  PreLoadCheck reports a file's encryption without loading it, and needs no password.
$checker = new CkPdf();
$info = new CkJsonObject();
$success = $checker->PreLoadCheck('qa_output/memo_encrypted.pdf',$info);
if ($success == false) {
    print $checker->lastErrorText() . "\n";
    exit;
}

print 'encrypted: ' . $info->BoolOf('encrypted') . "\n";
print 'openPasswordRequired: ' . $info->BoolOf('openPasswordRequired') . "\n";

//  With the password, the PDF opens normally.
$reader = new CkPdf();
$reader->put_UserPassword('user-secret');
$success = $reader->LoadFile('qa_output/memo_encrypted.pdf');
if ($success == false) {
    print $reader->lastErrorText() . "\n";
    exit;
}

print 'pages: ' . $reader->get_NumPages() . "\n";

//  Sample output:

//  algorithm: aes-256
//  PDF version: 1.7
//  password needed to open: True
//  encrypted: True
//  openPasswordRequired: True
//  pages: 2

?>