How to easily manage an encrypted 2FA code list using GPG and OATHTOOL

get_2fa.sh

  #!/bin/bash
  
  # After breaking my phone one too many times, I decided to have a backup 2FA option.
  # Every 2fa app uses a QR code to add the secret key, and 
  # you can always choose to get a text version of that secret key
  # See: for an example
  # I choose to save that text code AS WELL as add it to my phone, so that I can 
  # get codes from my laptop, and back up those codes somewhere safe for easy migration 
  # between, or synchronization between all my devices.
  # This GIST will get codes from the command line.
  #
  # Assuming the 2fa secret is ABUNCHOFLETTERSANDNUMBERS
  # Save the codes in a text file as
  # PROVIDER.secret ABUNCHOFLETTERSANDNUMBERS
  # Then encrypt it using gpg
  # gpg -r <your email> -e 2fa.gpg
  # You can safely store 2fa.gpg on github if you'd like.
  # Now you have a .gpg file with some encrypted 2-factor authentication codes
  # To get a code for PROVIDER, call this script with 
  # WHO=PROVIDER get_2fa.sh
 
  oathtool -b --totp "`gpg -d 2fa.gpg 2>/dev/null | grep $WHO.secret | cut -d ' ' -f 2- `"
  
  # oathtool -b --totp ABUNCHOFLETTERSANDNUMBERS 
  # is the base command
  # but first we decrypt the file and find the PROVIDER.secret with:
  # gpg -d 2fa.gpg 2>/dev/null
  # Note, 2>/dev/null removes the "human readable" messaging, which isn't necessary but unclutters the command output
  # cut -d ' ' -f 2- will remove the PROVIDER.secret portion, leaving just  ABUNCHOFLETTERSANDNUMBERS
  # and the whole thing is encpasulated in quotes (") because some keys are of the form "ABUN CHOF LETT ERSA NDNU MBER"