[9front] Totp in factotum (advice and code)

[sirjofri <sirjofri+ml-9front@sirjofri.de>]

Hey all,

as I mentioned before, I am working on totp support in factotum. Here is what I have now:

http://sirjofri.de/oat/patches/totp.zip

(will do it as a proper patch when I'll submit it for inclusion, for future reference.)

I kindly ask for advice about the protocol, which I also describe here shortly for those who don't want to open the zip file:

The client protocol looks like this:

- write (optional): digits + seconds
- read: otp[digits] + time_remaining

This can be used by programs to display the current OTP code in a gui, for example.

The server protocol looks like this:

- write totp: otp[digits]
- read response: "valid" | error

This can be used to verify an entered OTP code.

The keys can look like this:

key proto=totp user=a role=client !secret=abc
key proto=totp user=a role=server digits=6 seconds=30 !secret=abc

Inside the code there are surely potential bugs, leaks, nonsense etc, just so you are prepared.

Note that I plan to submit this to the 9front distribution (if that's welcome), so any advice that can help improve quality is welcome.

sirjofri