php mcrypt to javascript aes integration

Question

I am trying to use javascript to encode data with AES-256-CBC and php mcrypt libraries to decode, and vise versa.

I am aware of the problematic nature of javascript and the fact that anyone sees the key, but I am using javascript a scripting tool for non-web environment - so not worried about it.

I found pidder https://sourceforge.net/projects/pidcrypt/

and encrypted some data with the demo page, then tried to decrypt it via php, but something is wrong and I can't seem to find what... I am using the same key with both ends, a 32 byte string

any pointers will be appreciated

~~~

$encrypted = "string after pidder encryption";  

$cipher = mcrypt_module_open(MCRYPT_RIJNDAEL_256,'',MCRYPT_MODE_CBC,'');    

$iv_size = mcrypt_enc_get_iv_size($cipher);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);

mcrypt_generic_init($cipher, $key, $iv);


$encrypted = base64_decode($encrypted);

echo "after b64decode: " . $encrypted . "\n\n\n";

$encrypted = mdecrypt_generic($cipher, $encrypted);

echo "decrypt:" . $encrypted;

~~~

Answer 1

Try MCRYPT_RIJNDAEL_128 with a 32-byte key for AES-256.

AES is a 128-bit block cipher that supports 128-, 192-, and 256-bit keys. Rijndael-256 is a 256-bit block cipher and AES. AES is a 128-bit block specification for Rijndael.