====== 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  =====

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

===== generate QR from command line  =====

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


====== migration ======

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

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

It is base64 encoded data stream. Data is encoded using protobufs. Decoder / converted is available: [[https://github.com/dim13/otpauth|Google Authenticator migration decoder]]

<code bash>
otpauth -link "$(zbarimg -q --raw Screenshot.png)"
</code>