totp

Minimal CLI tool for generating 6-digit TOTP 2FA codes (RFC 6238). Zero dependencies — Go stdlib only.

Works with GitHub, Google, AWS, and any service that uses standard TOTP.

Install

go install github.com/DabDavis/totp@latest

Or build from source:

git clone https://github.com/DabDavis/totp.git
cd totp
go build -o totp .

Usage

# Generate a code from a secret
totp YOURSECRETHERE
# 482931  (27s remaining)

# Or save the secret and run without args
echo 'YOURSECRETHERE' > ~/.totp && chmod 600 ~/.totp
totp

# Setup instructions
totp setup

GitHub 2FA Setup

1. Go to github.com → Settings → Password and authentication
2. Click Enable two-factor authentication
3. Click "setup key" under the QR code to get the base32 secret
4. Run totp <secret> and enter the 6-digit code on GitHub to verify
5. Download and save your recovery codes
6. Save the secret for future use:

   echo '<secret>' > ~/.totp && chmod 600 ~/.totp

How It Works

TOTP is HMAC-SHA1 over a time-based counter (30-second intervals), truncated to 6 digits per RFC 4226. The entire implementation is ~40 lines of Go.