Check wosign certificates

#!/usr/bin/env bash
#vi: set ft=sh :

AFTER_DATE="$(date --date "October 21 2016" +%s)"

# Or read from a file with something like `cat hosts | while read host; do`
for host in "google.com"; do
    echo "$host"
    cert_info="$(openssl s_client -connect $host:443 < /dev/null 2>/dev/null | sed -n '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' | openssl x509 -text -noout)"
    grep 'O=WoSign CA Limited' <<< "$cert_info" &>/dev/null || continue
    echo "  Is WoSign certificate"

    VALIDITY_DATE="$(sed -n 's/\s*Not Before: \(.*\)$/\1/p' <<< "$cert_info")"
    VALIDITY_TIMESTAMP="$(date --date "$VALIDITY_DATE" +%s)"

    [[ $VALIDITY_TIMESTAMP -le $AFTER_DATE ]] && continue
    echo "  Is signed after cutoff date"

    echo ">>>>> Certificate for $host is INVALID"
done