PDF Encrypt

PdfEncrypt applies or removes PDF encryption. It performs a full document rewrite (not incremental), rebuilding the page tree with the new encryption settings.

Opening a PDF

use Phpdftk\Pdf\Toolkit\PdfEncrypt;

// Unencrypted PDF
$enc = PdfEncrypt::open('doc.pdf');

// Already encrypted -- supply the password to open
$enc = PdfEncrypt::open('encrypted.pdf', password: 'secret');

// From string
$enc = PdfEncrypt::openString($pdfBytes);

Encrypting a PDF

use Phpdftk\Pdf\Toolkit\Encryption\EncryptionMethod;

$enc->encrypt('userpass', 'ownerpass', EncryptionMethod::Aes256)
    ->save('encrypted.pdf');

Encryption methods

Enum case	Algorithm
EncryptionMethod::Rc440	RC4 40-bit
EncryptionMethod::Rc4128	RC4 128-bit
EncryptionMethod::Aes128	AES 128-bit
EncryptionMethod::Aes256	AES 256-bit (default)

The default when no method is specified is Aes256.

Decrypting a PDF

Remove all encryption, producing an unprotected document:

PdfEncrypt::open('encrypted.pdf', password: 'secret')
    ->decrypt()
    ->save('decrypted.pdf');

Changing passwords

PdfEncrypt::open('encrypted.pdf', password: 'oldpass')
    ->changePasswords('newuser', 'newowner')
    ->save('rekeyed.pdf');

If no encryption method has been explicitly set, changePasswords defaults to AES-256.

Setting permissions

Use the Permission constants to control what operations are allowed:

use Phpdftk\Pdf\Toolkit\Encryption\Permission;

$enc->encrypt('user', 'owner', EncryptionMethod::Aes256,
    Permission::PRINT | Permission::COPY
);

Available permissions

Constant	Description
Permission::PRINT	Print the document
Permission::MODIFY	Modify document contents
Permission::COPY	Copy or extract text/graphics
Permission::ANNOTATE	Add or modify annotations
Permission::FILL_FORMS	Fill in form fields
Permission::ACCESSIBILITY	Extract text for accessibility
Permission::ASSEMBLE	Assemble the document (insert, rotate, delete pages)
Permission::PRINT_HIGH	High-resolution printing
Permission::ALL	All permissions granted

Permissions can also be set separately:

$enc->setPermissions(Permission::PRINT | Permission::FILL_FORMS);

Querying encryption status

$enc->isEncrypted(); // bool

Saving

// To file
$enc->save('output.pdf');

// To string
$bytes = $enc->toBytes();

Document info

$enc->getPageCount(); // int

Escape hatch

$reader = $enc->getReader(); // PdfReader