Convert Encrypt code in java to Ruby

Question

I have been trying to convert a code for encrypt in java to ruby, but I am not able to do it completely. I getting different values.

   passphrase = passphra         


        

Answer 1

require 'openssl'

Encrypt:

unencrypted = "I am a secret!"

initialize the Cipher for encrypt

cipher = OpenSSL::Cipher::AES.new(128, :CBC)
cipher.encrypt

create the key using SHA1

key = Digest::SHA1.hexdigest('secret_key')[0...32]
cipher.key = key

create the initialisationVector with an input

iv = Digest::SHA1.hexdigest('secret_iv')[0...32]
cipher.iv = iv

or create a random initialisationVector

iv = cipher.random_iv

run the encryption

encrypted = cipher.update(unencrypted) + cipher.final

Decrypt:

initialize the Cipher for decrypt

decipher = OpenSSL::Cipher::AES.new(128, :CBC)
decipher.decrypt

load the key and initialisationVector

decipher.key = key
decipher.iv = iv

decrypt the plaintext

plain = decipher.update(encrypted) + decipher.final

Does it match?

puts unencrypted == plain #=> true

For more information look at the Ruby Docs for the Class - OpenSSL::Cipher

Answer 2

Encrypt Code:

def aes(key,string)
  cipher = OpenSSL::Cipher::Cipher.new("aes-128-cbc")
  cipher.encrypt
  cipher.padding = 1
  cipher.key = hex_to_bin(Digest::SHA1.hexdigest('secret_key')[0..32])
  cipher_text = cipher.update(string)
  cipher_text << cipher.final
  return bin_to_hex(cipher_text).upcase
end

Decrypt Code:

def aes_decrypt(key, encrypted)
  encrypted = hex_to_bin(encrypted.downcase)
  cipher = OpenSSL::Cipher::Cipher.new("aes-128-cbc")
  cipher.decrypt
  cipher.padding = 1
  cipher.key = hex_to_bin(Digest::SHA1.hexdigest('secret_key')[0..32])
  d = cipher.update(encrypted)
  d << cipher.final
end

hex_to_bin and bin_to_hex

def hex_to_bin(str)
  [str].pack "H*"
end

def bin_to_hex(s)
  s.unpack('C*').map{ |b| "%02X" % b }.join('')
end

In My case, The java code was using default initialization vector, So I did not set any iv, Also, there was hex_to_bin was a missing piece there. So after that, all started working properly.

I hope it helps someone if they come across this issue.