Return time remaining in generate_otp()

[jleclanche]

I have the following code in my library:

def get_token(...):
	...
	msg = struct.pack(">Q", int(time / seconds))
	r = hmac.new(secret, msg, sha1).digest()
	k = r[19]
	idx = k & 0x0f
	h = struct.unpack(">L", r[idx:idx + 4])[0] & 0x7fffffff
	return h % (10 ** digits), -(time % seconds - seconds)

I'm replacing it with pyotp to simplify things. Unfortunately, I do use that second return parameter, which is the time remaining for the code's validity. I use it to show how long the user's code is still valid for, and to decide when to generate a new one.

I understand why at() doesn't return the time remaining but having it in generate_otp() at the very least would make this functionality possible.

Thanks!

[tilkinsc]

You could also take the time block used and subtract seconds from it.

[tilkinsc]

#87