Base64 with Encryption

Base64_Encryption.php

<?php

namespace Gajani;

class Base64_Encryption {

    public static function aes128Encrypt($key, $data) {
        if(16 !== strlen($key)) $key = hash('MD5', $key, true);
        $padding = 16 - (strlen($data) % 16);
        $data .= str_repeat(chr($padding), $padding);
        return base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $data, MCRYPT_MODE_CBC, str_repeat("\0", 16)));
    }
    public static function aes128Decrypt($key, $data) {
        $data = base64_decode($data);
        if(16 !== strlen($key)) $key = hash('MD5', $key, true);
        $data = mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, $data, MCRYPT_MODE_CBC, str_repeat("\0", 16));
        $padding = ord($data[strlen($data) - 1]);
        return substr($data, 0, -$padding);
    }

}

Test.php

<?php

use Gajani\Base64_Encryption;

$key = "somethingStrong";
$encryptedText = Base64_Encryption::aes128Encrypt($key, 'aligajani');

$decryptedText = Base64_Encryption::aes128Decrypt($key, $encryptedText);
echo $decryptedText;