two-factor

#!/usr/bin/env ruby --disable-gems

# Roll your own two-factor authentication! Place this file on a USB key, make
# it executable, then run:
#
#     two-factor --setup
#
# Now place each TOTP secret in its own file in the `keys/` directory. I like
# to name them after the website they apply to, but any name is fine. To
# generate a token, plug in your USB key and:
#
#     two-factor github.com
#
# Remember to unplug the key afterwards! To disable the unsafe eject warning on
# OSX, run:
#
#     sudo launchctl unload -w \
#         /System/Library/LaunchDaemons/com.apple.UserNotificationCenter.plist
#
# Recommended addition to your shell configuration:
#
#     # .zshrc
#     PATH=/Volumes/KEYS:$PATH
#     function tf() { two-factor $1 | pbcopy }

root = File.expand_path("../", __FILE__)

$available_keys = Dir[root + '/keys/*']

def usage
  $stderr.puts <<-EOS
usage: two-factor [--setup | KEYPREFIX]

Available keys:

#{$available_keys.map {|x| "  " + File.basename(x) }.join("\n")}

EOS
  exit 1
end

app = ARGV.shift
usage unless app

if app == '--setup'
  require 'fileutils'
  FileUtils.mkdir_p('keys')
  FileUtils.mkdir_p('vendor')
  Dir.chdir("vendor") do
    puts "Vendoring rotp gem..."
    system("gem unpack rotp")
  end
  exit 0
end

glob = root + "/vendor/*/lib"

Dir[glob].each do |lib|
  $LOAD_PATH.unshift lib
end

require 'rotp'

key = $available_keys.detect {|x| File.basename(x).start_with?(app) }
usage unless key

puts ROTP::TOTP.new(File.read(key).chomp).now