Table of Contents

Google's authenticator

Google Authenticator is based on and implements the Time-based One-Time Password (TOTP) algorithm specified in RFC 6238. 6-digit code.

single entry

read image from file

zbarimg -q Screenshot.png 
QR-Code:otpauth://totp/Google%3Auser%40example.com?secret=base32secret&issuer=Google

generate QR from command line

qrencode -t ANSI256UTF8 'otpauth://totp/Google%3Auser%40example.com?secret=base32secret&issuer=Google'

migration

All entries are exported as huge QR code. After read it with 

zbarimg --raw -q Screenshot.png 
QR-Code:otpauth-migration://offline?data=...

It is base64 encoded data stream. Data is encoded using protobufs. Decoder / converted is available: Google Authenticator migration decoder 

otpauth -link "$(zbarimg -q --raw Screenshot.png)"