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Perl 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.

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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

$pdf = chilkat::CkPdf->new();
$success = $pdf->LoadFile("qa_data/pdf/two_page_memo.pdf");
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\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 = chilkat::CkJsonObject->new();
$jsonOut = chilkat::CkJsonObject->new();
$success = $pdf->Protection("encrypt",$json,$jsonOut);
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

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

#  Writing the file applies it.
$success = $pdf->WriteFile("qa_output/memo_encrypted.pdf");
if ($success == 0) {
    print $pdf->lastErrorText() . "\r\n";
    exit;
}

#  PreLoadCheck reports a file's encryption without loading it, and needs no password.
$checker = chilkat::CkPdf->new();
$info = chilkat::CkJsonObject->new();
$success = $checker->PreLoadCheck("qa_output/memo_encrypted.pdf",$info);
if ($success == 0) {
    print $checker->lastErrorText() . "\r\n";
    exit;
}

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

#  With the password, the PDF opens normally.
$reader = chilkat::CkPdf->new();
$reader->put_UserPassword("user-secret");
$success = $reader->LoadFile("qa_output/memo_encrypted.pdf");
if ($success == 0) {
    print $reader->lastErrorText() . "\r\n";
    exit;
}

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

#  Sample output:

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