#!/bin/sh
#
# CHECK SSL CERT for AIX
#
################################
#Get current date, and format it
CURRENT_DATE=$(date "+%b %d %H:%M:%S %Y")
CURRENT_DATE_YEAR=$(date "+%Y")
CURRENT_DATE_MONTH=$(date "+%m")
CURRENT_DATE_DAY=$(date "+%d")
CURRENT_DATE_HOUR=$(date "+%H")
CURRENT_DATE_MIN=$(date "+%M")
CURRENT_DATE_SEC=$(date "+%S")

#Get the end date of the certification and format it
GET_CERT_ENDDATE=$(openssl x509 -enddate -in <CERT PATH, FILENAME> -text -noout | grep "Not After" | cut -c 25- )
CERT_ENDDATE_YEAR=$(openssl x509 -enddate -in <CERT PATH, FILENAME> -text -noout | grep "Not After" | cut -c 41-44 )
CERT_ENDDATE_MONTH=$(openssl x509 -enddate -in <CERT PATH, FILENAME> -text -noout | grep "Not After" | cut -c 25-28 )
CERT_ENDDATE_DAY=$(openssl x509 -enddate -in <CERT PATH, FILENAME> -text -noout | grep "Not After" | cut -c 29-30 )
CERT_ENDDATE_HOUR=$(openssl x509 -enddate -in <CERT PATH, FILENAME> -text -noout | grep "Not After" | cut -c 32-33 )
CERT_ENDDATE_MIN=$(openssl x509 -enddate -in <CERT PATH, FILENAME> -text -noout | grep "Not After" | cut -c 35-36 )
CERT_ENDDATE_SEC=$(openssl x509 -enddate -in <CERT PATH, FILENAME> -text -noout | grep "Not After" | cut -c 38-39 )

#Display values
echo $GET_CERT_ENDDATE
echo $CURRENT_DATE

#Convert month name to number format
months="Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec"
month=$CERT_ENDDATE_MONTH
string="${months%$month*}"
	if [ $((${#string}/4 + 1)) -lt 10 ]; then
		monthnumber="0$((${#string}/4 + 1))"
	else
		monthnumber="$((${#string}/4 + 1))"
	fi

#Convert dates to timestamp
epoch() {
    echo "$1" | perl -MTime::Local -lne '
        ($year, $month, $day) = /(\d{4})(\d{2})(\d{2})/;
        print timelocal(0, 0, 0, $day, $month-1, $year-1900)
    '
}

CD_TIMESTAMP=$(epoch $CURRENT_DATE_YEAR$CURRENT_DATE_MONTH$CURRENT_DATE_DAY)		
CE_TIMESTAMP=$(epoch $CERT_ENDDATE_YEAR$monthnumber$CERT_ENDDATE_DAY) 	
		
#Calculate the difference between two dates
diff=$((CE_TIMESTAMP - CD_TIMESTAMP))

#Display the days until expire
echo $((diff / 86400))