#!/bin/bash
set -e

[[ -z $2 ]] && echo "usage: ${0##*/} <host> <port> [smtp]" && exit 1
host=$1
port=$2

[[ $3 = smtp ]] && smtp="-starttls smtp" || smtp=""

[[ ! -x `which openssl` ]] && echo install openssl or libressl first && exit 1

openssl version

echo Q | openssl s_client -servername $host -connect $host:$port $smtp 2>/dev/null | \
	openssl x509 -noout -text | less

# -showcerts