JWT::urlsafeB64Decode

static function urlsafeB64Decode($input)
{
	$remainder = strlen($input) % 4;
	if ($remainder) {
		$padlen = 4 - $remainder;
		$input .= str_repeat('=', $padlen);
	}
	return base64_decode(strtr($input, '-_', '+/'));
}