MariaDB [(none)]> show global variables like '%ssl%';
+---------------------+--------------------------------+
| Variable_name       | Value                          |
+---------------------+--------------------------------+
| have_openssl        | YES                            |
| have_ssl            | YES                            |
| ssl_ca              | /etc/mysql/ssl/ca.pem          |
| ssl_capath          |                                |
| ssl_cert            | /etc/mysql/ssl/server-cert.pem |
| ssl_cipher          |                                |
| ssl_crl             |                                |
| ssl_crlpath         |                                |
| ssl_key             | /etc/mysql/ssl/server-key.pem  |
| version_ssl_library | OpenSSL 1.1.1d  10 Sep 2019    |
+---------------------+--------------------------------+

and created the database and user:

MariaDB [(none)]> show grants for netxms@netxms.mgmt.lan;
+---------------------------------------------------------------------+
| Grants for netxms@netxms.mgmt.lan                                   |
+---------------------------------------------------------------------+
| GRANT USAGE ON *.* TO `netxms`@`netxms.mgmt.lan` REQUIRE X509       |
| GRANT ALL PRIVILEGES ON `db_netxms`.* TO `netxms`@`netxms.mgmt.lan` |
+---------------------------------------------------------------------+

Here is my NetXMS configuration:

## Logging
# Log file name
LogFile=/var/log/netxmsd

# Increase logging verbosity, 0 (only errors) to 9 (verbose debug)
DebugLevel=0

## Database configuration.
DBDriver=mariadb.ddr
DBServer=mariadb.mgmt.lan
DBName=db_netxms
DBLogin=netxms
DBPassword=

But I can't seem to get a connection working.  NXDBMGR INIT tells me Access denied, probably because it's not presenting the X509 cert & key to MariaDB. Where do I drop my user cert & key in NetXMS, and how do I configure mariadb driver to use X509?