Javascript implementation of AES compatible with PHP's mcrypt

Question

Problem

I need to encrypt data in Javascript and decrypt it in PHP. Mcrypt seems the way to go on the PHP side, and AES seems thoroughly good enough, but I'm having trouble finding a javascript decryption algorithm that matches it. Any suggestions? I'm open to replacing any of the assumptions (mcrypt, aes, ECB, etc) if it'll help get a compatible js encryption/decryption library.

Code

The PHP looks pretty much like this:

$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
$encrypted = mcrypt_encrypt( MCRYPT_RIJNDAEL_256, $key, $plaintext,
        MCRYPT_MODE_ECB,$iv );

Rationale

Not that it matters, but the point here is to encrypt some credentials to an external system so that we can pass it around our server without our analytics and logging servers picking it up in the clear. It'll eventually be decrypted in the PHP just before it's sent to the external system.

Answer 1

I ended up using the SlowAES library, which has parallel implementations in PHP and JS:

http://kevinkuchta.com/_site/2011/08/matching-php-and-js-encryption/