aes_sample.rb

require "openssl"
require "base64"

include Base64

# 0-15: 24
plain_text = "p"*15
# 44
#plain_text = "p"*16
# 44
#plain_text = "p"*31
# 64
#plain_text = "p"*32
# 64
#plain_text = "p"*47
#
#plain_text = "p"*48


cipher = OpenSSL::Cipher::AES128.new(:CBC)
cipher.encrypt
key = cipher.random_key
iv = cipher.random_iv
cipher_text = cipher.update(plain_text) + cipher.final

cipher = OpenSSL::Cipher::AES128.new(:CBC)
cipher.decrypt
cipher.key = key
cipher.iv = iv
decrypted_plain_text = cipher.update(cipher_text) + cipher.final

puts "AES128 in CBC mode"
puts "Key: " + urlsafe_encode64(key*8)
puts "Key size: " + key.size.to_s

puts "Iv: " + urlsafe_encode64(iv)
puts "Iv size: " + iv.size.to_s

puts "Plain text: " + plain_text
puts "Plain text size: " + plain_text.size.to_s
puts "Cipher text: " + urlsafe_encode64(cipher_text)
puts "Cipher size: " + urlsafe_encode64(cipher_text).size.to_s
puts "Decrypted plain text: " + decrypted_plain_text