require 'openssl'

ALGORITHM = 'AES-256-CBC'

puts 'Enter message to encrypt:'
message = gets.chomp

cipher = OpenSSL::Cipher.new(ALGORITHM)

key = cipher.random_key
hex_key = key.unpack('H*').first

puts "Randomly generated key in hexadecimal: #{hex_key}"

cipher.encrypt
cipher.key = key

encrypted_message = cipher.update(message)
encrypted_message << cipher.final

hex_encrypted_message = encrypted_message.unpack('H*').first

puts "Encrypted message in hexadecimal: #{hex_encrypted_message}"