2fa is a two-factor authentication agent

Table of Contents

• Supported Imports
• Usage
• Example
• Importing from 2FAS
• Fuzzy Matching

2fa is a command-line tool for managing two-factor authentication keys

Supported Imports

• 2FAS

Raise an issue to request support for Authenticator Apps.

Usage

go install github.com/jammutkarsh/2fa@latest

2fa -add [-7] [-8] [-hotp] name
2fa -list
2fa name # Uses fuzzy matching and automatically copies to clipboard
2fa -import 2fas <file>

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 and automatically copies it to the system clipboard. The name supports fuzzy matching - if the search matches exactly one key, that code will be displayed and copied. If multiple keys match, all matching codes will be listed (clipboard is not used for multiple matches).

2fa -import 2fas <file> imports keys from a 2FAS JSON export file. This allows bulk import of all your 2FA keys. Keys that already exist will be skipped.

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
$

The code is automatically copied to your clipboard! Just paste it.

Or use fuzzy matching to type less:

$ 2fa git
268346
$

Or to see all codes:

$ 2fa
268346 github
123456 google
$

Importing from 2FAS

Export your 2FAS data to a JSON file, then import it:

$ 2fa -import 2fas export.json
imported: Discord
imported: GitHub
imported: Google

Successfully imported 3 key(s)
$

Fuzzy Matching

The tool supports fuzzy matching for key names, making it easier to find keys:

$ 2fa gthb
268346
$

If multiple keys match, all will be displayed:

$ 2fa go
multiple matches found for "go":
123456  google
789012  gojek
$