Google Authenticator available as a public service?

Question

Is there public API for using the Google Authenticator (two factor authentication) on self-running (e.g. LAMP stack) web apps?

Answer 1

There are a variety of libraries for PHP (The LAMP Stack)

PHP

https://code.google.com/p/ga4php/

http://www.idontplaydarts.com/2011/07/google-totp-two-factor-authentication-for-php/

You should be careful when implementing two-factor auth, you need to ensure your clocks on the server and client are synchronized, that there is protection in place against brute-force attacks on the token and that the initial seed used is suitably large.