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

To set up a launcher for the che_guevara_otp command, copy Che.svg to /usr/share/icons/hicolor/scalable/apps/ and copy che_guevara_otp.desktop to /usr/share/applications/, for example:

sudo cp /usr/local/lib/python3.5/dist-packages/che_guevara_otp-2018.5.11.1653-py3.5.egg/che_guevara_otp/data/Che.svg /usr/share/icons/hicolor/scalable/apps/

sudo cp /usr/local/lib/python3.5/dist-packages/che_guevara_otp-2018.5.11.1653-py3.5.egg/che_guevara_otp/data/che_guevara_otp.desktop /usr/share/applications/

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

che_guevara_otp terminal loop display

The command che_guevara_otp displays time-based one-time passcodes at 30 second intervals based on secrets stored in a specified file ~/.secrets. 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

future

Under consideration are functions to install the launcher and icon infrastructure based on Python version information.