Is there any difference between Ruby 'AES-128-CBC' and PHP 'rijndael-128' encryption?

Question

Ruby code is

require 'base64'
require 'openssl'

def ruby_dec iv, key, encrypted
  decipher = OpenSSL::Cipher::AES.new(128, :CBC)
  #decipher.padding = 0 
  decipher.decrypt
  decipher.key = key
  decipher.iv = iv
  ciphertext = Base64.decode64 encrypted
  decipher.update(ciphertext) + decipher.final
end


def ruby_enc iv, key, plaintext 
  enc = OpenSSL::Cipher.new 'aes-128-cbc'
  enc.encrypt
  enc.key = key
  enc.iv = iv

  Base64.encode64(enc.update(plaintext) + enc.final)
end

iv = Base64.decode64("TOB+9YNdXSbkSYIU7D/IpQ==")
key =  Base64.decode64("7DxoShENB0D+8xrwOwSbi1TPQBiIaFq2yveoUkutCpM=")
plaintext = "testtesttest"

encrypted = ruby_enc iv, key, plaintext
puts "encrypted is #{encrypted}"
ruby_dec iv, key, encrypted
puts "plaintext is #{plaintext}"

then

$ ruby enc_dec.rb #the above code
encrypted is LXJmnM7t+HGKi2iI51ethA==
plaintext is testtesttest

Now PHP code is

function php_dec($iv, $key, $encrypted) { 
  $cipher_algorithm    = 'rijndael-128';
  $cipher_mode = 'cbc';

  $key = base64_decode($key);
  $iv = base64_decode($iv);
  $ciphertext = base64_decode($enctypted);
  return $ciphertext;
}


function php_enc($iv, $key, $plaintext){
  $td = mcrypt_module_open(MCRYPT_RIJNDAEL_128, '', MCRYPT_MODE_CBC, '');

  $mcrypt_key = base64_decode($key);
  $iv = base64_decode($iv);
  mcrypt_generic_init($td, $mcrypt_key, $iv);

  $ciphertext = mcrypt_generic($td, $plaintext);

  retun base64_encode($ciphertext); 
}

$iv = base64_decode("TOB+9YNdXSbkSYIU7D/IpQ==");
$key =  base64_decode("7DxoShENB0D+8xrwOwSbi1TPQBiIaFq2yveoUkutCpM=");
$plaintext = "testtesttest";

$encrypted = php_enc($iv, $key, $plaintext);
echo "encrypted is ".$encrypted."\n";
php_dec($iv, $key, $encrypted);
echo "plaintext is ".$plaintext."\n";

$ruby_encrypted = base64_encode("LXJmnM7t+HGKi2iI51ethA==");
php_dec($iv, $key, $ruby_encrypted);
echo "plaintext is ".$plaintext."\n";

then I get

$ php enc_dec.php
encrypted is SUR33tXu32JjR9JAKIGL7w==
plaintext is testtesttest
plaintext is testtesttest

the ciphertext is different from the ruby one. Now I try to decrypt ruby with cipher text made by PHP.

$ pry
  [1] pry(main)> load 'enc_dec.rb'
  [2] pry(main)> iv = Base64.decode64("TOB+9YNdXSbkSYIU7D/IpQ==")    
  => "L\xE0~\xF5\x83]]&\xE4I\x82\x14\xEC?\xC8\xA5"
  [3] pry(main)> key =  Base64.decode64("7DxoShENB0D+8xrwOwSbi1TPQBiIaFq2yveoUkutCpM=")    
  => "\xEC<hJ\x11\r\a@\xFE\xF3\x1A\xF0;\x04\x9B\x8BT\xCF@\x18\x88hZ\xB6\xCA\xF7\xA8RK\xAD\n\x93"
  [4] pry(main)> ruby_dec iv, key, Base64.decode64("SUR33tXu32JjR9JAKIGL7w==")
  OpenSSL::Cipher::CipherError: data not multiple of block length
  from enc_dec.rb:12:in `final'
  [5] pry(main)>

Is there any difference between Ruby 'AES-128-CBC' and PHP 'rijndael-128' encryption? and how can i decrypt with ruby?

Could you remove your previous question about the same thing? Note that you should edit your question if you just want to provide more information. — Maarten Bodewes
Thank you your comment, I deleted previous one. and from next time I do edit my question. — Hisatake Ishibashi

Erik Oppedijk Erik Oppedijk · Accepted Answer · 2014-10-15T14:57:33

There is a difference between AES and Rijndael in the meaning of 128, in AES the 128 is the keysize, in Rijndael it is the blocksize.

The key you used is larger than 128 bits I believe.

See this article: http://www.leaseweblabs.com/2014/02/aes-php-mcrypt-key-padding/

Is there any difference between Ruby 'AES-128-CBC' and PHP 'rijndael-128' encryption?

1 Answers