[cairo] pdf encryption, read-write permissions

[chris nuernberger]

I would love to use cairo as a rendering backend for a tool that I am
writing, but we need a few PDF options and I don't know if they are in
cairo already or what.  I searched the archives a bit but must have
missed the response I am looking for.

Specifically, I need to know if cairo supports, plans on supporting,
or how difficult it would be to add pdf encryption (I know it is
pathetic but it is a business requirement), as pdf read-write
permissions.

I *really* want to use cairo as I can see it is super powerful, but I
need these types of options.  Please don't just tell me they don't
exist, give me a couple paths (I code, so I could add them myself if
necessary) to get them if they don't exist.

Chris