#!/bin/sh

# example certificate_issuer_checker script

# pull cert from stdin to shell variable
cert=`openssl x509 -text`

# check for MD5 signatures
echo "$cert" | grep 'Algorithm: md5' > /dev/null 2>&1
if [ $? = "0" ]; then
    echo "MD5 signature detected" 1>&2
    exit 1
fi

# all done
exit 0