General information for default certificate locations for various services.
The order will be cert,key, ca/chain, combined (cert+ca)and their related directadmin.conf settings, where applicable.
Apache/LiteSpeed
apachecert=/etc/httpd/conf/ssl.crt/server.crt
apachekey=/etc/httpd/conf/ssl.key/server.key
apacheca=/etc/httpd/conf/ssl.crt/server.ca
OpenLiteSpeed
openlitespeed_cert=/usr/local/lsws/ssl.crt/server.crt
openlitespeed_key=/usr/local/lsws/ssl.key/server.key
openlitespeed_ca=/usr/local/lsws/ssl.crt/server.ca
Nginx
nginx_cert=/etc/nginx/ssl.crt/server.crt
nginx_key=/etc/nginx/ssl.key/server.key
nginx_ca=/etc/nginx/ssl.crt/server.ca
/etc/nginx/ssl.crt/server.crt.combined
Exim + Dovecot
/etc/exim.cert
/etc/exim.key
Note that the exim.cert contains BOTH the cert and the ca, in that order.
User Domain
/usr/local/directadmin/data/users/USER/domains/DOMAIN.COM.cert
/usr/local/directadmin/data/users/USER/domains/DOMAIN.COM.key
/usr/local/directadmin/data/users/USER/domains/DOMAIN.COM.ca
/usr/local/directadmin/data/users/USER/domains/DOMAIN.COM.combined
DirectAdmin may automatically create the .combined version of the cert, when needed by various servers.
If you see one on disk beside the cert, put the cert + ca into the combined file, eg:
cat /etc/nginx/ssl.crt/server.crt /etc/nginx/ssl.crt/server.ca > /etc/nginx/ssl.crt/server.crt.combined