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. Perl

use chilkat();

$success = 0;

#  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 = chilkat::CkPdf->new();
$info = chilkat::CkJsonObject->new();

#  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 == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

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

#  A PDF that needs a password to open.
$success = $pdf->PreLoadCheck("qa_data/pdf/encrypted_user_password.pdf",$info);
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

print "encrypted_user_password.pdf" . "\r\n";
print "  encrypted: " . $info->BoolOf("encrypted") . "\r\n";
print "  method: " . $info->stringOf("method") . "\r\n";
print "  algorithm: " . $info->stringOf("algorithm") . "\r\n";
print "  openPasswordRequired: " . $info->BoolOf("openPasswordRequired") . "\r\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 == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

print "no_copy_permission.pdf" . "\r\n";
print "  encrypted: " . $info->BoolOf("encrypted") . "\r\n";
print "  openPasswordRequired: " . $info->BoolOf("openPasswordRequired") . "\r\n";
print "  may copy: " . $info->BoolOf("permissions.copy") . "\r\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 == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

if ($info->BoolOf("openPasswordRequired") == 1) {
    #  An application would prompt for the password here.
    $pdf->put_UserPassword("secret");
}

$success = $pdf->LoadFile("qa_data/pdf/encrypted_user_password.pdf");
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

print "loaded, pages: " . $pdf->get_NumPages() . "\r\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