Get TLS cert expiration and send reminder

get_tls.sh

#!/bin/bash
SECONDS=0
RED='\033[0;31m'
WHITE='\033[1;37m'
CYAN='\033[0;36m'
YELLOW='\033[1;33m'
NC='\033[0m' # No Color

LIST='host1 host2 host3'

echo ""
echo "Checking domain TLS cert expiration dates..."
echo ""

for DOMAIN in $LIST
    do
	echo -e "FQDN >>> ${WHITE}${DOMAIN}${NC}"
	echo '================================='
	OUT=$(echo | openssl s_client -showcerts -servername ${DOMAIN} -connect ${DOMAIN}:443 2>/dev/null | openssl x509 -inform pem -noout -text | grep 'Not After' | awk '{ print $4, $5, $7 }')
	echo -e "Expires: ${YELLOW}${OUT}${NC}" 
        echo $OUT
        EXPDUR=$(($(date +%s) + (86400*7)))
        echo epoch how many days to expir ${EXPDUR}
        EXPDAT=$(date -d "${OUT}" +"%s")
        echo epoch expir date ${EXPDAT}
	echo ""
            if [ ${EXPDUR} -gt ${EXPDAT} ] ; then
                echo -e "\n${RED}WARNING TLS cert expires in less than 7 days. The TLS cert for ${DOMAIN} will expire on ${OUT}${NC}\n"
                echo "Warning TLS cert for domain ${DOMAIN} is about to expire.\n\nThe TLS cert for ${DOMAIN} will expire on ${OUT}. Please resolve this issue quickly, you lazy bastard." | mail -s "Warning TLS cert for domain ${DOMAIN} is about to expire." [email protected]
                else
                    echo -e "Everything is awesome"
            fi
    done

#x509=$(echo | openssl s_client -showcerts -servername ${domain} -connect ${domain}:443 2>/dev/null | openssl x509 -inform pem -noout -text)

#echo $x509

# do a date compare
# send a reminder if n num days is less than x days

displaytime () {
   local T=$SECONDS
   local D=$((T/60/60/24))
   local H=$((T/60/60%24))
   local M=$((T/60%60))
   local S=$((T%60))
   [[ $D > 0 ]] && printf '%d days ' $D
   [[ $H > 0 ]] && printf '%d hours ' $H
   [[ $M > 0 ]] && printf '%d minutes ' $M
   [[ $D > 0 || $H > 0 || $M > 0 ]] && printf 'and '
   printf '%d seconds\n' $S
}

echo "Took $(displaytime) to complete ${0}."
exit 0


#!/bin/bash
# openssl checkend option looks to be useful, d'oh!
# -checkend arg ; Checks if the certificate expires within the next arg seconds and exits non-zero if yes it will expire or zero if not.
DAYS=7
 
for file in "$@"; do
    openssl x509 -checkend $(( 86400 * $DAYS )) -in "$file" > /dev/null
    if [ $? != 0 ]; then
        echo "==> Certificate $file is about to expire soon:"
        openssl x509 -enddate -in "$file" -noout
    fi
done