https://github.com/rsc/2fa

Two-factor authentication on the command line
https://github.com/rsc/2fa

Last synced: 25 days ago
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Two-factor authentication on the command line

• Host: GitHub
• URL: https://github.com/rsc/2fa
• Owner: rsc
• License: bsd-3-clause
• Created: 2017-11-22T01:40:20.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2024-08-17T12:34:18.000Z (3 months ago)
• Last Synced: 2024-10-01T20:41:52.665Z (about 1 month ago)
• Language: Go
• Size: 7.81 KB
• Stars: 1,738
• Watchers: 29
• Forks: 157
• Open Issues: 16
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• go-awesome - 2fa - Two-factor authentication on the command line (Open source library / Encrypt And Decrypt)

README

        
2fa is a two-factor authentication agent.

Usage:

    go install rsc.io/2fa@latest

    2fa -add [-7] [-8] [-hotp] name

    2fa -list

    2fa name

`2fa -add name` 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.

By default the new key generates time-based (TOTP) authentication codes; the

`-hotp` flag makes the new key generate counter-based (HOTP) codes instead.

By default the new key generates 6-digit codes; the `-7` and `-8` flags select

7- and 8-digit codes instead.

`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. If `-clip` is specified, `2fa` also copies to the code to the system

clipboard.

With no arguments, `2fa` prints two-factor authentication codes from all

known time-based keys.

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.

The keychain is stored unencrypted in the text file `$HOME/.2fa`.

## Example

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: nzxxiidbebvwk6jb

    $

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

    $ 2fa github

    268346

    $

Or to type less:

    $ 2fa

    268346	github

    $