# mysql --ssl
mysql> show variables like '%ssl%';
+---------------+-----------------+
| Variable_name | Value           |
+---------------+-----------------+
| have_openssl  | YES             |
| have_ssl      | YES             |
| ssl_ca        | ca.pem          |
| ssl_capath    |                 |
| ssl_cert      | server-cert.pem |
| ssl_cipher    |                 |
| ssl_crl       |                 |
| ssl_crlpath   |                 |
| ssl_key       | server-key.pem  |
+---------------+-----------------+

mysql> status
--------------
mysql  Ver 14.14 Distrib 5.7.21-20, for debian-linux-gnu (x86_64) using  6.3

Connection id:      31
Current database:
Current user:       root@localhost
SSL:            Cipher in use is ECDHE-RSA-AES128-GCM-SHA256

mysql -h 127.0.0.1 -P 3306 -u root  -p  --ssl-ca=/var/lib/mysql/ca.pem --ssl-cert=/var/lib/mysql/server-cert.pem --ssl-key=/var/lib/mysql/server-key.pem

ERROR 2026 (HY000): SSL connection error: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed