WindowsLiveLogin::decodeToken

function decodeToken($token, $cryptkey=null)
{
	if (!$cryptkey) {
		$cryptkey = $this->_cryptkey;
	}
	if (!$cryptkey) {
		$this->fatal("Error: decodeToken: Secret key was not set. Aborting.");
	}

	$ivLen = 16;
	$token = $this->u64($token);
	$len = strlen($token);

	if (!$token || ($len <= $ivLen) || (($len % $ivLen) != 0)) {
		$this->debug("Error: decodeToken: Attempted to decode invalid token.");
		return;
	}

	$iv = substr($token, 0, 16);
	$crypted = substr($token, 16);

	return openssl_decrypt($crypted, "AES-128-CBC", $cryptkey, OPENSSL_RAW_DATA | OPENSSL_NO_PADDING, $iv);
}