• Copyright (c) 2012, http://www.phpgangsta.de
• Author: Michael Kliewe, @PHPGangsta
• Licensed under the BSD License.

This PHP class can be used to interact with the Google Authenticator mobile app for 2-factor-authentication. This class can generate secrets, generate codes, validate codes and present a QR-Code for scanning the secret.

For a secret installation you have to make sure that used codes cannot be reused (replay-attack).

See example files

php example1.php
Secret is: OQB6ZZGYHCPSX4AK

Google Charts URL for the QR-Code: https://www.google.com/chart?chs=200x200&chld=M|0&cht=qr&chl=otpauth://totp/infoATphpgangsta.de%3Fsecret%3DOQB6ZZGYHCPSX4AK

Checking Code '848634' and Secret 'OQB6ZZGYHCPSX4AK':
OK

• ??? What do you need?

If you like this script or have some features to add: contact me, visit my blog, fork this project, send pull requests, you know how it works.