Encrypt/Decrypt File with AES in Ruby

aes.rb

require 'yaml'
require 'openssl'

def read_config 
	unless File.exist?(ENV["HOME"] + "/.mabs_api.yml")
		key = {
			:key => cipher.random_key, 
			:iv => cipher.random_iv 
		}
	
		File.write(ENV["HOME"] + "/.mabs_api.yml", key.to_yaml)
	end

	YAML.load_file(ENV["HOME"] + "/.mabs_api.yml")
end

# Used as flag to whether to encrypt or decrypt the file
# By default we encrypt the files
fdecrypt = false

aes = OpenSSL::Cipher::AES.new(128, :CBC)

if ARGV.empty? || ARGV[0] == "--help"
	abort "Use --encrypt/--decrypt to encrypt/decrypt the given file"
end

case ARGV[0]
	when "--encrypt"
		aes.encrypt
	when "--decrypt"
		aes.decrypt
		fdecrypt = true
	else
		abort "Unknow arguments #{ARGV[0]}"
end

config = read_config
aes.key = config[:key]
aes.iv = config[:iv]

content = File.read(ARGV[1])

if fdecrypt
	filename = ARGV[1].chomp(".enc")
	final_content = aes.update(content) + aes.final
else
	filename = ARGV[1] + ".enc"
	final_content = aes.update(content) + aes.final
end

File.write(filename, final_content)