lib/keen/aes_helper.rb
require 'openssl'
require 'digest'
require 'base64'
module Keen
class AESHelper
class << self
def aes256_decrypt(key, iv_plus_encrypted)
aes = OpenSSL::Cipher::AES.new(256, :CBC)
iv = iv_plus_encrypted[0, aes.key_len]
encrypted = iv_plus_encrypted[aes.key_len, iv_plus_encrypted.length]
aes.decrypt
aes.key = unhexlify(key)
aes.iv = unhexlify(iv)
aes.update(unhexlify(encrypted)) + aes.final
end
def aes256_encrypt(key, plaintext, iv = nil)
raise OpenSSL::Cipher::CipherError.new("iv must be 16 bytes") if !iv.nil? && iv.length != 16
aes = OpenSSL::Cipher::AES.new(256, :CBC)
aes.encrypt
aes.key = unhexlify(key)
aes.iv = iv unless iv.nil?
iv ||= aes.random_iv
hexlify(iv) + hexlify(aes.update(plaintext) + aes.final)
end
def hexlify(msg)
msg.unpack('H*')[0]
end
def unhexlify(msg)
[msg].pack('H*')
end
end
end
end