Find the right issuing CA certificate for the given certificate (based on the subject) and symlink it to the specific target file.

link-ssl-ca.sh

#! /bin/bash
set -e

CERT_FILE="$1"
CA_FILE="$2"
CA_DIR="$3"

ISSUER=$(openssl x509 -in ${CERT_FILE} -noout -issuer | sed "s/^issuer= //g")

for PEM in ${CA_DIR}/*; do
    SUBJECT=$(openssl x509 -in ${PEM} -noout -subject | sed "s/^subject= //g")

    if [ "$ISSUER" = "$SUBJECT" ]; then
        ln -sf ${PEM} ${CA_FILE}
        exit
    fi
done

echo "Unable to find right issuer certificate for certificate (issuer = $ISSUER)" >&2
exit 1