PDF metadata not encrypted

[lfavole]

Error details
The title of the PDF file doesn't appear correctly because it is not encrypted.
I have tested the code snippet below with the master branch (beb40d4).

Minimal code

from fpdf import FPDF

pdf = FPDF()
pdf.set_title("Title")
pdf.set_encryption("")
pdf.add_page()

pdf.set_font("helvetica", size=12)
pdf.write(txt="Hello world!")
pdf.output("test_enc.pdf")

Environment

• Operating System: Windows 11
• Python version: 3.11.4
• fpdf2 version used: 2.7.4

Proposed solution
Update the file fpdf/output.py at line 81:

class PDFInfo(PDFObject):
    def __init__(
        self,
        title,
        subject,
        author,
        keywords,
        creator,
        producer,
        creation_date: PDFDate,
    ):
        super().__init__()
        self.title = PDFString(title, encrypt=True) if title else None
        self.subject = PDFString(subject, encrypt=True) if subject else None
        self.author = PDFString(author, encrypt=True) if author else None
        self.keywords = PDFString(keywords, encrypt=True) if keywords else None
        self.creator = PDFString(creator, encrypt=True) if creator else None
        self.producer = PDFString(producer, encrypt=True) if producer else None
        self.creation_date = creation_date

I have added encrypt=True to all metadata.

[Tolker-KU]

Hi!

Have you tried enabling the encrypt_metadata flag in the call to set_encryption()?

https://github.com/PyFPDF/fpdf2/blob/beb40d4ff0e0d0813b2ed5453286f9454bba5de7/fpdf/fpdf.py#L363

[andersonhc]

I can see the same problem on our reference files.

https://github.com/PyFPDF/fpdf2/blob/master/test/encryption/encryption_rc4.pdf

The document properties are not being correctly encrypted since #736

[Tolker-KU]

I can see the same problem on our reference files.

https://github.com/PyFPDF/fpdf2/blob/master/test/encryption/encryption_rc4.pdf

The document properties are not being correctly encrypted since #736

That file is also generated with encrypt_metdata=False

https://github.com/PyFPDF/fpdf2/blob/df762e360658dd062c8ee030c9e2722aecdc3ad1/test/encryption/test_encryption.py#L43-L51

Do you see the same problem in https://github.com/PyFPDF/fpdf2/blob/master/test/encryption/encrypt_metadata.pdf generated with encrypt_metdata=True

https://github.com/PyFPDF/fpdf2/blob/df762e360658dd062c8ee030c9e2722aecdc3ad1/test/encryption/test_encryption.py#L139-L155

[andersonhc]

That file is also generated with encrypt_metdata=False

encrypy_metadata only applies to XMP metadata.
The regular PDF Info always has to be encrypted as a string.

[lfavole]

Hello @Tolker-KU,
I have the same problem as in test_encryption_rc4.

I have tried this code snippet:

from fpdf import FPDF

pdf = FPDF()
pdf.set_title("Title")
pdf.set_encryption("", encrypt_metadata=True)
pdf.add_page()

pdf.set_font("helvetica", size=12)
pdf.write(txt="Hello world!")
pdf.output("test_enc.pdf")

but the metadata is still not encrypted correctly.

If I apply my fix, the metadata is correctly encrypted whether encrypt_metadata is True or False.

Moreover, I need the DocumentInformation metadata because it is supported by all the PDF readers.
XMP metadata is not supported by browsers (Chrome and Firefox).

[Lucas-C]

The document properties are not being correctly encrypted since #736

Damn, that was me... 😅
Sorry about this

So this is indeed a bug.
Is anyone willing to submit a PR to fix it?

[Lucas-C]

Thank you @lfavole for fixing this in PR #867! 👍