Perl 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. Chilkat2 Perl

use strict;
use warnings;
use Chilkat2;

# 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

my $pdf = Chilkat2::Pdf->new;
my $info = Chilkat2::JsonObject->new;

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

print "two_page_memo.pdf\n";
print '  encrypted: ', ($info->BoolOf('encrypted') ? 1 : 0), "\n";

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

print "encrypted_user_password.pdf\n";
print '  encrypted: ', ($info->BoolOf('encrypted') ? 1 : 0), "\n";
print '  method: ', $info->StringOf('method'), "\n";
print '  algorithm: ', $info->StringOf('algorithm'), "\n";
print '  openPasswordRequired: ', ($info->BoolOf('openPasswordRequired') ? 1 : 0), "\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) {
    print $pdf->LastErrorText, "\n";
    exit;
}

print "no_copy_permission.pdf\n";
print '  encrypted: ', ($info->BoolOf('encrypted') ? 1 : 0), "\n";
print '  openPasswordRequired: ', ($info->BoolOf('openPasswordRequired') ? 1 : 0), "\n";
print '  may copy: ', ($info->BoolOf('permissions.copy') ? 1 : 0), "\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) {
    print $pdf->LastErrorText, "\n";
    exit;
}

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

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

print 'loaded, pages: ', $pdf->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