#!/bin/bash

if [ -n "$3" ]; then
	KEYOPT=`echo "-y $3"`
fi
NOWDATE=`date  +%s`
RRSIGDATE=`dig @${2} $KEYOPT +noall +answer $1 RRSIG | head -n 1 | awk '{print $9}'`

YEARDATE=`echo ${RRSIGDATE} | cut -c -4 `
MONTHDATE=`echo ${RRSIGDATE} | cut -c -6 | cut -c 5- `
DAYDATE=`echo ${RRSIGDATE} | cut -c -8 | cut -c 7- `

TMPDATE=`echo ${YEARDATE}-${MONTHDATE}-${DAYDATE}`

EXPIREDATE=`date -d $TMPDATE +%s`

TIMELEFT=`expr $EXPIREDATE - $NOWDATE`

echo $TIMELEFT