che_guevara_otp 2018.1.15.1652

Python OTP

che_guevara_otp

This module generates one-time passcodes that are based either on a counter or time using a secret key that is assumed known by server and client.

The counter-based passcodes are hash-based one-time passcodes (HOTP) and are defined in RFC 4226. The time-based passcodes are time-based one-time passcodes (TOTP) and are defined in RFC 6238. For HOTP, the pseudorandom function used is HMAC-SHA-1 and the associated counter should be incremented after each passcode generation. TOTP is HOTP with a specified time interval for validity. A common time interval is 30 seconds.

setup

pip install che_guevara_otp

module

HOTP passcodes can be generated in a way like the following:

>>> import che_guevara_otp
>>> secret = "XXXXXXXXXXXXXXXX"
>>> for nonce in range(0, 3):
...     print(che_guevara_otp.HOTP(secret = secret, nonce = nonce))
...
561452
686073
840123

TOTP passcodes can be generated in a way like the following, where the default time interval is 30 seconds:

>>> import che_guevara_otp
>>> secret = "XXXXXXXXXXXXXXXX"
>>> print(che_guevara_otp.TOTP(secret = secret))
826402

display_che_guevara_otp.py

The script display_che_guevara_otp.py displays time-based one-time passcodes at 30 second intervals based on secrets stored in a specified file. The file is unencrypted plaintext so userspace encryption combined with other security is assumed. The contents of the secrets file should be of the following form:

OmegaBay:         XXXXXXXXXXXXXXXXXXXXXXXX
Missile Emporium: YYYYYYYYYYYYYYYYYYYYYYYY