2fa is a two-factor authentication manager in command line for macOS, utilizing the macOS keychain to protect your TOTP secrets.

2fa was forked from rsc/2fa and rewrote.

Usage:

go get -u github.com/hSATAC/2fa

2fa add [account]
2fa add --screenshot
2fa list
2fa show [account]

2fa add [account] adds a new key to the 2fa keychain with the given name. It prints a prompt to standard error and reads a two-factor key from standard input. Two-factor keys are short case-insensitive strings of letters A-Z and digits 2-7.

2fa add --screenshot adds a new key by taking a screenshot of the qrcode. See it in action here: (gif).

The new key generates time-based (TOTP) authentication codes.

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

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

The default time-based authentication codes are derived from a hash of the key and the current time, so it is important that the system clock have at least one-minute accuracy.

During GitHub 2FA setup, at the “Scan this barcode with your app” step, click the “enter this text code instead” link. A window pops up showing “your two-factor secret,” a short string of letters and digits.

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

$ 2fa add github
2fa key for github: JBSWY3DPEHPK3PXP
$

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

$ 2fa show github
      [14]  899393

The first 2 digits is the countdown of the TOTP.

Press any key to copy the code and exit.

Screenshot QRCode scanner requires zbar to run, Please install zbar.

$ brew install zbar