Two-factor authentication example with Vaadin

tl:dr This example shows how to make a Vaadin application work with Google Authenticator.

An example using two-factor authentication (also known as two-step verification) in a Vaadin application. This allows the application to add an additional layer of security, by requiring a one-time "TOTP" password to be entered.

Related links

TOTP RFC: http://tools.ietf.org/html/rfc6238

TOTP java library: https://github.com/wstrange/GoogleAuth (there are other implementation on GitHub, and a messy reference implementation in the RFC)

QRCode add-on: http://vaadin.com/addon/qrcode

Google Authenticator

• Android: https://play.google.com/store/apps/details?id=com.google.android.apps.authenticator2
• iOS: https://itunes.apple.com/en/app/google-authenticator/id388497605