I have a few ebooks I’ve purchased online that came as password protected PDFs. While mildly annoying while trying to read them on a desktop system, it’s patently absurd when I try to move them over to the iPad to use. There are a bunch of hacks floating around describing how to use conversion software to remove the password. Such as convert to a postscript file and then back to a PDF. Generally you end up with a pretty crappy PDF out the other end. You always loose hyperlinks (table of content or index), and a lot of times the formatting can get screwy. Fortunately I found a few comments mentioning qpdf, which is in the default repos for Ubuntu at least:

  • sudo apt-get install qpdf
  • qpdf --password=******** --decrypt lame_pass_version.pdf happy_version.pdf

Yay! No more crashing iBooks trying to read stuff I paid money for. And there’s an actual preview of the cover on the bookshelf now. Amazing.