Encrypt, Decrypt large files

example_encrypt_decrypt.rb

# From https://tjay.dev/howto-working-efficiently-with-large-files-in-ruby/

# Encrypt
cipher = OpenSSL::Cipher::AES256.new(:CBC)
cipher.encrypt
cipher.key = KEY
cipher.iv = IV

file = nil
enc_file = nil

profile do 
  buf = ""
  file = File.open("large_1G.txt", "rb")
  enc_file = File.open("large_1G.txt.enc", "wb")
  while buf = file.read(4096)
    enc_file << cipher.update(buf)
  end
  enc_file << cipher.final
end

file.close
enc_file.close


# Decrypt
decipher = OpenSSL::Cipher::AES256.new(:CBC)
decipher.decrypt
decipher.key = KEY
decipher.iv = IV

dec_file = nil
enc_file = nil

profile do 
  buf = ""
  enc_file = File.open("large_1G.txt.enc", "rb")
  dec_file = File.open("large_1G.txt.dec", "wb")
  while buf = enc_file.read(4096)
    dec_file << decipher.update(buf)
  end
  dec_file << decipher.final
end

dec_file.close
enc_file.close