SSL証明書の有効期限を確認するbash script

SSL証明書の期限を確認する

こんな感じで確認できる。

$ sslexpire secure.nicovideo.jp
https://secure.nicovideo.jp SSL certificate expires after 39 days and 13 hours (2014/06/30 23:59:00 JST)

#!/bin/bash
#
# usage: $0 domain[:port] [alert days] [timeout]
# ex)
# $0 yahoo.com 365
#

server=${1//:*/}
port=${1/*:/}
test "$server" = "$port" && port=443
limit=${2-60}   # default 60 days
timeout=${3-3}  # default timeout 3 seconds

notafter=$(timeout $timeout openssl s_client -connect $server:$port < /dev/null 2> /dev/null | openssl x509 -enddate -noout 2> /dev/null | cut -d= -f2)

if [ "$notafter" ]; then
    s=$(( $(date --date "$notafter" +%s) - $(date +%s) ))

    if [ $limit -ge $((s / 86400)) ]; then
        d=$(date --date "$notafter" +"%Y/%m/%d %H:%M:%S %Z")
        days=$((s/86400))
        hours=$((s%86400/3600))
        echo -n "https://$server SSL certificate expires after "
        if [ $days -gt 0 ]; then
            echo -n $days day
            if [ $days -gt 1 ]; then
                echo -n s
            fi
        fi
        if [ $hours -gt 0 ]; then
            if [ $days -gt 0 ]; then
                echo -n " and "
            fi
            echo -n $hours hour
            if [ $hours -gt 1 ]; then
                echo -n s
            fi
        fi
        echo " ($d)"

        exit 1
    fi
else
    echo "https://$server is not supported SSL or timeout?"
    exit 1
fi

タイムアウトの処理はもうちょっとなんとかしたほうがいい。