Authentication libraries: Two factor auth support

Thanks for the responses. After a bit of hunting around I found a fork of Ion Auth 2 that includes TOTP and have just had a quick play around with it and all appears to work well: https://github.com/SpyTec/CodeIgniter-Ion-Auth-OTP

It's for IonAuth2, not 3. At some point I might look at integrating it with IonAuth 3 as don't think 2 is wildly different to 3.