PHP encrypt and decrypt in node JS

I have a encryption in PHP and a decryption in node JS.
I know there are many topics about this. But all of them state that it doesn’t work.
In my case it does. Well sort of.

PHP

define('CRYPT_KEY', 'bwAZA48aaYd34PGhBWSutIIFaCu4oAe/Ps24/Rx+bw0=');

class Encryption {
  public function encrypt($data) {
    $output = false;
    $methode = "AES-256-CBC";
    $key = base64_decode(CRYPT_KEY);

    $ivSize  = openssl_cipher_iv_length($methode);
    $ivData  = openssl_random_pseudo_bytes($ivSize);
    $encData = openssl_encrypt($data, $methode, $key, OPENSSL_RAW_DATA, $ivData);
    $output = base64_encode($ivData . $encData);

    return $output;
  }

  public function decrypt($data) {
    $output = false;
    $methode = "AES-256-CBC";
    $key = base64_decode(CRYPT_KEY);

    $ivSize  = openssl_cipher_iv_length($methode);
    $data = base64_decode($data);
    $ivData   = substr($data, 0, $ivSize);
    $encData = substr($data, $ivSize);
    $output = openssl_decrypt($encData, $methode, $key, OPENSSL_RAW_DATA, $ivData);

    return $output;
  }
}

echo $encryption->encrypt('Hello world'); 
// output: 8ZtGcgDeSCN8f+jrZ/W2tWL40DIncjmCwanFiNrEhyE=

node JS

const key = Buffer.from('bwAZA48aaYd34PGhBWSutIIFaCu4oAe/Ps24/Rx+bw0=', 'base64');
const iv = Buffer.from(crypto.randomBytes(16), 'base64');


function decrypt(data) {
  const decipher = crypto.createDecipheriv('aes-256-cbc', key, iv);
  const decripted = decipher.update(data, 'base64', 'utf8') + decipher.final('utf8');
  
  return decripted;
}

console.log('Output: ', decrypt('8ZtGcgDeSCN8f+jrZ/W2tWL40DIncjmCwanFiNrEhyE='));

the first part of the output is scrambled

result: ▬�2���◄p��r♣�'Hello world

Does someone know why this happens. Im I doing something wrong?

>Solution :

The reason for the problem is that in the PHP code IV and actual ciphertext are concatenated. But in the NodeJS code the separation is missing (instead, a new, random IV is used incorrectly).

The separation of IV and ciphertext can be done as follows:

const data = Buffer.from('tIF2bpl7Ro8lZbslAgBqJNqwIqn4pNWZrGkUaWcJQzo=', 'base64');
const iv = data.subarray(0, 16);
const ciphertext = data.subarray(16);

Since the ciphertext is now passed to decrypt() as buffer and not Base64 encoded, the decryption in decrypt() has to be implemented as follows:

const decripted = decipher.update(data, '', 'utf8') + decipher.final('utf8');

Note that the posted NodeJS example does not work. It returns an EVP_DecryptFinal_ex:bad decrypt error, indicating that the key and ciphertext are not related.