SSL Certificates Location
For creating SSL certificates, you have to install one of httpd module called mod_ssl, and after that, a corresponding configuration file will be created at /etc/httpd/conf.d/ssl.conf.
ssl.conf
[root@test ~]# ls -l /etc/httpd/conf.d/
total 36
...
-rw-r--r--. 1 root root 9534 Jul 15 2008 ssl.conf
...
domain.crt
You can look inside the file and see the default path of SSL Certificates.
[root@test ~]# vi /etc/httpd/conf.d/ssl.conf
...
SSLCertificateFile /etc/pki/tls/certs/localhost.crt
...
SSLCertificateKeyFile /etc/pki/tls/private/localhost.key
...
There are two important files, one is for SSL certificate and the other is for the private key, which means, you should put your SSL certificate under /etc/pki/tls/certs to follow the convention.
Even though, the path of the key and certs can be changed according to your requirement.