pdfencrypt

#!/usr/bin/env ruby

=begin

= Info
    Encrypts a PDF document.

= License
    Copyright (C) 2016  Guillaume Delugré.

    Origami is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Origami is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with Origami.  If not, see <http://www.gnu.org/licenses/>.

=end

begin
    require 'origami'
rescue LoadError
    $: << File.join(__dir__, '../lib')
    require 'origami'
end
include Origami

require 'optparse'

class OptParser
    BANNER = <<USAGE
Usage: #{$0} [<PDF-file>] [-p <password>] [-c <cipher>] [-s <key-size>] [--hardened] [-o <output-file>]
Encrypts a PDF document. Supports RC4 40 to 128 bits, AES128, AES256.
Bug reports or feature requests at: http://github.com/gdelugre/origami

Options:
USAGE

    def self.parser(options)
        OptionParser.new do |opts|
            opts.banner = BANNER

            opts.on("-o", "--output FILE", "Output PDF file (stdout by default)") do |o|
                options[:output] = o
            end

            opts.on("-p", "--password PASSWORD", "Password of the document") do |p|
                options[:password] = p
            end

            opts.on("-c", "--cipher CIPHER", "Cipher used to encrypt the document (Default: AES)") do |c|
                options[:cipher] = c
            end

            opts.on("-s", "--key-size KEYSIZE", "Key size in bits (Default: 256)") do |s|
                options[:key_size] = s.to_i
            end

            opts.on("--hardened", "Use stronger key validation scheme (only AES-256)") do
                options[:hardened] = true
            end

            opts.on_tail("-h", "--help", "Show this message") do
                puts opts
                exit
            end
        end
    end

    def self.parse(args)
        options =
        {
            output: STDOUT,
            password: '',
            cipher: 'aes',
            key_size: 256,
            hardened: false
        }

        self.parser(options).parse!(args)

        options
    end
end

begin
    @options = OptParser.parse(ARGV)

    target = (ARGV.empty?) ? STDIN : ARGV.shift
    params =
    {
        verbosity: Parser::VERBOSE_QUIET,
    }

    pdf = PDF.read(target, params)
    pdf.encrypt(
        user_passwd:    @options[:password],
        owner_passwd:   @options[:password],
        cipher:         @options[:cipher],
        key_size:       @options[:key_size],
        hardened:       @options[:hardened]
    )
    pdf.save(@options[:output], noindent: true)

rescue
    abort "#{$!.class}: #{$!.message}"
end