[NFBCS] THOUGHTS ON PASSWORD PROTECTED PDF FILES

[Jim Barbour]

Yeah, the password protected PDF + AllowPrint option is definitely showing its age. The idea was to prevent, or at least add a lot of friction to, removing or changing water marks, or other kinds of branding.  These days, it's pretty easy to just say "send this PDF document to a my virtual printer, which understands PDF", thus giving you unprotected PDF code to work with.

Jim

On Wed, Aug 05, 2026 at 08:22:41AM -0700, Brian Buhrow via NFBCS wrote:
> 	Hello everyone!  Yesterday I learned a little something about password protected pdf files
> I thought folks might find useful.
> 
> It is my usual practice to run pdf files through pdftotext, part of the poppler open source pdf
> tools package.  In particular, I usually use the -layout option, to, as much as possible, preserve
> the print layout of the original pdf file.
> 
> Yesterday I discovered the Poppler tools can extract the text and images from password
> protected pdf files without the password.  I don't know if this is true for all password
> protected files, but it certainly was handy for the particular file I was working with, since
> Acrobat Reader wouldn't show me anything without the password, which I didn't have.
> 
> I figured out that it is possible to check to see if this trick will work by using the pdfinfo
> command from the same package.  If the output from the pdfinfo command says the file is locked
> or password protected, but the printing capability is enabled, you'll be able to extract the
> text and images from the file using the pdftotext or pdftoppm commands respectively.  If the
> text you  get is insufficient or you need the images for some other reason, this is an
> excellent way to work around a password on a locked pdf file.
> 
> -thanks
> -Brian
> 
> 
> 
> 
> _______________________________________________
> NFBCS mailing list
> NFBCS at nfbnet.org
> http://nfbnet.org/mailman/listinfo/nfbcs_nfbnet.org
> To unsubscribe, change your list options or get your account info for NFBCS:
> http://nfbnet.org/mailman/options/nfbcs_nfbnet.org/jbar%40barcore.com
>