Support password-protected PDFs

[gco]

Opening an encrypted PDF without a password (bank statement) results in:

NotImplementedError: password-protected PDFs are currently not supported

This is a TODO mentioned here

[jorisschellekens]

I'm currently working on supporting encrypted (that is to say password protected) PDF documents.

The PDF standard lists various possible algorithms, I will not implement all of them in the next release, but the general framework and the most basic cases should be present.

Kind regards,
Joris Schellekens

[joshuisken]

I see quite some code for this but I would like to see a small example how to open a password protected pdf-file.
Providing a password to PDF.loads() is not enough:

AssertionError: R is not 2 or 3. A number specifying which revision of the standard security handler shall be used to interpret this dictionary.

How can I set R?

[jorisschellekens]

Currently, password-protected PDF documents (reading and/or writing thereof) are not supported.

I do have a useful contact from way back when I still worked at another PDF related company. He has already helped me with a bug in borb and was going to help me on the whole encryption thing.

I'll see if I can't poke him again.

Kind regards,
Joris Schellekens

[mfikrin]

Is there an update for password-protected PDF documents? I'm looking forward to an example of that. Thank You

[jorisschellekens]

Update: It should be possible for some of the supported types of password-protected PDF documents to be opened by borb ijn the upcoming release. I am going to close this issue. Further issues regarding this functionality will need to be more specific (so that I can get an idea of which type of encryption needs to be supported specifically).

The following TestCase will also be added to the tests:

class TestReadEncryptedPDF(TestCase):

    def test_open_encrypted_pdf(self):
        input_file: Path = self.get_artifacts_directory(True) / "input_001.pdf"
        with open(input_file, "rb") as fh:
            PDF.loads(fh, password="appeltje")

    def test_read_encrypted_pdf(self):
        input_file: Path = self.get_artifacts_directory(True) / "input_001.pdf"

        # open
        l: SimpleTextExtraction = SimpleTextExtraction()
        with open(input_file, "rb") as fh:
            PDF.loads(fh, password="appeltje", event_listeners=[l])

        # compare text
        text: str = l.get_text()[0]
        assert text.startswith("Video provides a powerful way to help you prove your point.")

Which attempts to read the following PDF:
input_001.pdf

Which is protected by the password appeltje (it means "little apple" in Dutch)

Kind regards,
Joris Schellekens