Developer and refugee from Reddit

  • 0 Posts
  • 5 Comments
Joined 3 years ago
cake
Cake day: July 2nd, 2023

help-circle
  • Yes, it’s base64. And what’s behind it could be anything that can be attached to an email.

    In this case, it’s a PDF. If the base64 text can be extracted accurately, then the PDF that was attached to the email can be recreated.

    The challenge is basically twofold:

    1. There’s a lot of text, and it needs to be extracted perfectly. Even one character being wrong corrupts it and makes it impossible to decode.
    2. As the article points out, there are lots of visual problems with the encoded text, including the shitty font it’s displayed with, which makes automating the extraction damn near impossible. OCR is very good these days, but this is kind of a perfect example of text that it has trouble with.

    As for my approach, I’m basically just slowly and painstakingly running several OCR tools on small bits at a time, merging the resulting outputs, and doing my best to correct mistakes manually.



  • Long story short:

    • Some of the emails in the file dump had attachments.
    • The way attachments work in emails is that they’re converted to encoded text.
    • That encoded text was included - badly - in the file dump.
    • So it’s theoretically possible to convert them back to the original files, but it will take work to get the text back. Every character has to be exactly correct.

    Source: I’m a software developer and I’m currently trying to recover one of these attachments.