- (totp-time-step #!key (time (current-seconds)) (period 30) (t0 0)) -> fixnumprocedure
Returns the absolute time step for time, i.e. (quotient (- time t0) period). Adding totp-verify's returned offset to this value recovers the absolute step a successful verification matched, which is what a caller should compare against (and then store as) its "last accepted step" to prevent replay.