Crypto js encrypted string not decrypt in php

Question

I am using following js code to encrypt string

var text = 'should be decrypted!';
var key = 'HighlySecretKeyForJsEncryption!!';
var encrypted = CryptoJS.AES.encrypt(text, key);
console.log(encrypted.toString());

output : U2FsdGVkX19vf+s6/+eB8A+3iKFCl1A0e+oe0BSbcMVGxb64FL35Q3CB/LZNu4ng

and this what I did in php to decrypt this

function decrypt($toDecrypt) {
    $key = "HighlySecretKeyForJsEncryption!!";
    $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
    $toDecrypt = base64_decode($toDecrypt);
    return rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, substr($toDecrypt, $iv_size), MCRYPT_MODE_CBC, substr($toDecrypt, 0, $iv_size)));
}

But this is not working, it gives me garbage string.

Answer 1

From docs :

var encrypted = CryptoJS.AES.encrypt("Message", "Secret Passphrase");
var decrypted = CryptoJS.AES.decrypt(encrypted, "Secret Passphrase");

CryptoJS supports AES-128, AES-192, and AES-256. It will pick the variant by the size of the key you pass in. If you use a passphrase, then it will generate a 256-bit key.

You probabily need to pass the constant MCRYPT_RIJNDAEL_256 when decrypting php-side

More about AES encryption / decrytption in php: https://stackoverflow.com/a/3422787/4499267