PHP Extension Requires Chilkat v11.7.0+

Find Out Whether a PDF Needs a Password Before Loading It

See more PDF Protection Examples

Demonstrates PreLoadCheck, which examines a PDF file without loading it and without any password. It reports whether the file is encrypted, by which method and algorithm, whether a password is needed to open it, and what its permissions are. An application uses it to decide whether to ask for a password, or which certificate it needs, before calling LoadFile. PreLoadCheckBd does the same for a PDF held in memory. 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

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

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

$pdf = new CkPdf();
$info = new CkJsonObject();

//  A PDF that is not encrypted.  Nothing but "encrypted" is reported for it.
$success = $pdf->PreLoadCheck('qa_data/pdf/two_page_memo.pdf',$info);
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

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

//  A PDF that needs a password to open.
$success = $pdf->PreLoadCheck('qa_data/pdf/encrypted_user_password.pdf',$info);
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

print 'encrypted_user_password.pdf' . "\n";
print '  encrypted: ' . $info->BoolOf('encrypted') . "\n";
print '  method: ' . $info->stringOf('method') . "\n";
print '  algorithm: ' . $info->stringOf('algorithm') . "\n";
print '  openPasswordRequired: ' . $info->BoolOf('openPasswordRequired') . "\n";

//  A PDF that opens without a password but is restricted.  The permissions are readable without
//  any password.
$success = $pdf->PreLoadCheck('qa_data/pdf/no_copy_permission.pdf',$info);
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

print 'no_copy_permission.pdf' . "\n";
print '  encrypted: ' . $info->BoolOf('encrypted') . "\n";
print '  openPasswordRequired: ' . $info->BoolOf('openPasswordRequired') . "\n";
print '  may copy: ' . $info->BoolOf('permissions.copy') . "\n";

//  The typical use: ask for a password only when one is needed, then load.
$success = $pdf->PreLoadCheck('qa_data/pdf/encrypted_user_password.pdf',$info);
if ($success == false) {
    print $pdf->lastErrorText() . "\n";
    exit;
}

if ($info->BoolOf('openPasswordRequired') == true) {
    //  An application would prompt for the password here.
    $pdf->put_UserPassword('secret');
}

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

print 'loaded, pages: ' . $pdf->get_NumPages() . "\n";

//  Sample output:

//  two_page_memo.pdf
//    encrypted: False
//  encrypted_user_password.pdf
//    encrypted: True
//    method: password
//    algorithm: rc4-128
//    openPasswordRequired: True
//  no_copy_permission.pdf
//    encrypted: True
//    openPasswordRequired: False
//    may copy: False
//  loaded, pages: 1

?>