class `OpenSSL::Cipher`
inherits `Reference` ¶

A class which can be used to encrypt and decrypt data using a specified cipher.

require "random/secure"

key = Random::Secure.random_bytes(64) # You can also use OpenSSL::Cipher#random_key to do this same thing
iv = Random::Secure.random_bytes(32)  # You can also use OpenSSL::Cipher#random_iv to do this same thing

def encrypt(data)
  cipher = OpenSSL::Cipher.new("aes-256-cbc")
  cipher.encrypt
  cipher.key = key
  cipher.iv = iv

  io = IO::Memory.new
  io.write(cipher.update(data))
  io.write(cipher.final)
  io.rewind

  io.to_slice
end

def decrypt(data)
  cipher = OpenSSL::Cipher.new("aes-256-cbc")
  cipher.decrypt
  cipher.key = key
  cipher.iv = iv

  io = IO::Memory.new
  io.write(cipher.update(data))
  io.write(cipher.final)
  io.rewind

  io.gets_to_end
end