Requiring TLS on MariaDB Server

Overview

MariaDB Enterprise Server and MariaDB Community Server support data-in-transit encryption, which secures data transmitted over the network. The server and the clients encrypt data using the Transport Layer Security (TLS) protocol, which is a newer version of the Secure Socket Layer (SSL) protocol.

TLS must be manually enabled on the server, and then the server can be configured to require it.

Requiring TLS

  1. Acquire an X509 certificate and a private key for the server.

    If you are performing testing, then self-signed certificates and keys might be sufficient.

  2. Determine which system variables and options you need to configure.

    Mandatory system variables and options for requiring TLS include:

    System Variable/Option

    Description

    require_secure_transport

    When this option is enabled, connections attempted using insecure transport will be rejected. Secure transports are SSL/TLS, Unix sockets, or named pipes.

    ssl_cert

    X509 cert in PEM format

    ssl_key

    X509 key in PEM format

    ssl_ca

    CA file in PEM format

    Useful system variables and options for TLS include:

    System Variable/Option

    Description

    ssl_capath

    CA directory

    ssl_cipher

    SSL cipher to use

    ssl_crl

    CRL file in PEM format

    ssl_crlpath

    CRL directory

    tls_version

    TLS protocol version for secure connections.

  3. Choose a configuration file in which to configure your system variables and options.

    It is not recommended to make custom changes to one of the bundled configuration files. Instead, it is recommended to create a custom configuration file in one of the included directories. Configuration files in included directories are read in alphabetical order. If you want your custom configuration file to override the bundled configuration files, then it is a good idea to prefix the custom configuration file's name with a string that will be sorted last, such as z-.

    • On RHEL, CentOS, Rocky Linux, and SLES, a good custom configuration file would be: /etc/my.cnf.d/z-custom-my.cnf

    • On Debian and Ubuntu, a good custom configuration file would be: /etc/mysql/mariadb.conf.d/z-custom-my.cnf

  4. Set your system variables and options in the configuration file.

    They need to be set in a group that will be read by MariaDB Server, such as [mariadb] or [server].

    For example:

    [mariadb]
...
ssl_cert = /certs/server-cert.pem
ssl_key = /certs/server-key.pem
ssl_ca = /certs/ca-cert.pem

  5. Restart the server.

    $ sudo systemctl restart mariadb

  6. Connect to the server using MariaDB Client:

    $ sudo mariadb

  7. Confirm that TLS is enabled by confirming that the have_ssl system variable is YES with the SHOW GLOBAL VARIABLES statement:

    SHOW GLOBAL VARIABLES LIKE 'have_ssl';

    +---------------+-------+
| Variable_name | Value |
+---------------+-------+
| have_ssl      | YES   |
+---------------+-------+

  8. Confirm that TLS is required by confirming that the require_secure_transport system variable is ON with the SHOW GLOBAL VARIABLES statement:

    SHOW GLOBAL VARIABLES LIKE 'require_secure_transport';

    +--------------------------+-------+
| Variable_name            | Value |
+--------------------------+-------+
| require_secure_transport | ON    |
+--------------------------+-------+