Linux SSL Certs
Adding CA Cert
mkdir /usr/share/ca-certificates/extra
You need a pem format SSL Cert in Linux: https://support.ssl.com/Knowledgebase/Article/View/19/0/der-vs-crt-vs-cer-vs-pem-certificates-and-how-to-convert-them
cp CA.crt /usr/share/ca-certificates/extra/ chmod 755 CA.crt
You can copy many including your intermediates
openssl x509 -hash -noout -in CA.crt
Link your hash to your new CA.crt location do them all
ln -s /usr/share/ca-cerfificates/extra/CA.crt /etc/ssl/certs/TheHash.0
Update your ca-db
update-ca-certificates