Difference in PHP encryption from iOS and .NET

Question

I have an issue when communicating encrypted between iOS and PHP. I have an app that encrypts a string and sends it to a PHP server that decrypts it. That part works just fi

Answer 1

After long test's I think this encrypt method will be right for tests:

function mc_encrypt($str = "Affe", $key = "12345678901234567890123456789012")
{
    $str = "Affe";
  $block = mcrypt_get_block_size('rijndael-256', 'cbc');
    $pad = $block - (strlen($str) % $block);
    $str .= str_repeat(chr($pad), $pad);

    $encoded =  base64_encode(mcrypt_encrypt('rijndael-256', $key, $str, 'cbc',$key));
    file_put_contents("test.txt",$encoded);
    return $encoded;
}

I got this on iOS: v+cB4woDYANTozUbOgxJ4rWKb59EfLf6NkRE/Ee0kYY= But if I try to decrypt (see above), I got (null)

On the Other if I encrypt on iOS, I got this one: UUfn34iyNlSK40VaehloaQ==

definitely to short (or the other is to long)...searching again for errors.