Big feature request: Improve PDF support, cover all versions, better hash format

[JDLH]

I am a new user of hashcat. I am trying to use it on a collection of PDF files spanning decades, to recover some passwords. I know a bit about PDF's format, but I am naive about the constraints of hashcat's architecture and history. My experience led me to write up a rather big feature request:

Improve PDF support, cover all versions, better hash format (issue 3976)

…Make one hashcat invocation able to find passwords for hashes of any version of PDF file, including owner as well as user password. Also, make an improved hash format which a) can describe hashes for any version of PDF file, b) can include a filename and path of the PDF document described by each hash, which may need to be c) a structured format like JSON or bencode rather than the current asterisk-separated flat file format, with d) clear documentation of the hash format, and e) an official, reliable pdf-to-hash tool.…

The issue has more about my view of the current situation, and the desired outcome. I welcome comments and discussion, here, or in issue #3976 on GitHub.