On the subjects of TFA ok, not sure how I missed this one appearing, but I found
Two factor authentication with Google Authenticator https://issues.apache.org/jira/browse/GUACAMOLE-96 not sure how to comment on that one, but as a comment to L.J. van Ruiten, In terms of user interface, has this been considered https://github.com/Arno0x/TwoFactorAuth .It would make nice simple Personally i'd say , only let the admins enable or disable the extra authentication but I guess having the QR code on their settings screen would make it easier for them to add their own authenticator. Although at this point I'd live with typing things manually at a unix prompt and holding their phones to register them if it at least worked for me . danielm
