2fa is a two-factor authentication agent.

2fa is inspired by Russ Cox's 2fa library, written in go. I thought re-writing it in Ruby would be a good exercise.

Usage:

2fa --name [NAME]
2fa [NAME]
2fa --list

2fa --name [NAME] adds a new key to the 2fa keychain with the given name. It prints a prompt to standard output and reads a two-factor key from standard input.

The new key generates a time-based (TOTP) authentication codes made up of 6-digit.

2fa --list lists the names of all the keys in the keychain.

2fa [NAME] prints a two-factor authentication code from the key with the given name.

The keychain is stored unencrypted in the file $PWD/.2fa.

Example

During Twitter 2FA setup, at the "scan the following QR code with your camera" step, click the "Can’t scan QR code?" link. A new window is shown with a code - a bold string of letters and digits.

Add it to 2fa under the name twitter, typing the secret at the prompt:

$ 2fa --name twitter
2fa key for twitter: KERZ 2YRQ INYK 7GH4
$

Then whenever Twitter prompts for a 2FA code, run 2fa to obtain one:

$ 2fa twitter
268346
$

Or list the names of all keys:

$ 2fa --list
twitter
$