How to Create a Self-Signed SSL Certificate for MariaDB on Ubuntu 24.04

Create MariaDB SSL Certificate

A self-signed SSL certificate for MariaDB on Ubuntu 24.04 encrypts data sent between your applications and the MariaDB database server. This certificate encryption makes database connections significantly more secure. This guide demonstrates how to create the self-signed SSL certificate if you haven’t already, ensuring your MariaDB setup is protected.

If you haven’t already created a self-signed certificate, you can follow the post below to create one on Ubuntu.

Create a self-signed certificate on Ubuntu

Once created, continue below to use the certificates in MariaDB.

Configure MariaDB SSL Connection

After you create your self-signed SSL certificate, MariaDB needs to use this certificate for secure connections. MariaDB requires a new folder, and your certificate files should be copied into the /etc/mysql/ssl/ directory so MariaDB can find and use them.

Copy the certificate files from `/etc/ssl/private` to `/etc/mysql/ssl` to secure your MariaDB server. Next, adjust the permissions to grant the MariaDB account access. Open the MariaDB configuration file using the command below and add the following lines before saving your changes.

Then, adjust the permissions to allow the MariaDB account access.

sudo cp /etc/ssl/private/{server.crt,server.key} /var/lib/mysql/pki/
sudo chown -R mysql:mysql /var/lib/mysql/pki

After that, open the MariaDB configuration file using the command below.

sudo nano /etc/mysql/mariadb.conf.d/50-server.cnf

Add these lines to the file and save your changes.

# * SSL/TLS

# For documentation, please read
# https://mariadb.com/kb/en/securing-connections-for-client-and-server/
#ssl-ca = /etc/mysql/cacert.pem
#ssl-cert = /etc/mysql/server-cert.pem
#ssl-key = /etc/mysql/server-key.pem
#require-secure-transport = on

ssl-cert = /var/lib/mysql/pki/server.crt
ssl-key = /var/lib/mysql/pki/server.key

..............
..............

Now, exit and restart MariaDB.

sudo systemctl restart mariadb

Validate MariaDB SSL settings

You can check if your MariaDB SSL settings are working correctly by logging into the database and looking at the SSL variables. This confirms that your self-signed certificate is active and being used for secure connections.

First, log into the MariaDB database.

sudo mariadb

Then, run the SQL statement to list the SSL tables.

show variables like '%ssl%'; 

You should see a result similar to this:

+---------------------+-------------------------------+
| Variable_name       | Value                         |
+---------------------+-------------------------------+
| have_openssl        | YES                           |
| have_ssl            | YES                           |
| ssl_ca              |                               |
| ssl_capath          |                               |
| ssl_cert            | /var/lib/mysql/pki/server.crt |
| ssl_cipher          |                               |
| ssl_crl             |                               |
| ssl_crlpath         |                               |
| ssl_key             | /var/lib/mysql/pki/server.key |
| version_ssl_library | OpenSSL 3.0.13 30 Jan 2024    |
+---------------------+-------------------------------+
10 rows in set (0.001 sec)

You can also check how long the certificates are valid by running the command below.

show status like 'Ssl_server_not%';

It should show output lines like these:

You can force specific MariaDB users to always use SSL for secure connections when they log in. This requirement ensures each user establishes an encrypted link, preventing any unencrypted access to your database.

For new users, run the SQL statement below to create a user named jdoe and set a password.

CREATE USER jdoe IDENTIFIED BY 'type_your_password_here' require ssl; 

Remember to replace jdoe with the username you want to create.

Run the statement below to verify all database accounts that must use SSL for connections.

select user,host,ssl_type,plugin from mysql.user;

Your output should appear similar to this:

+-------------+-----------+----------+-----------------------+
| User        | Host      | ssl_type | plugin                |
+-------------+-----------+----------+-----------------------+
| mariadb.sys | localhost |          | mysql_native_password |
| root        | localhost |          | mysql_native_password |
| mysql       | localhost |          | mysql_native_password |
| jdoe        | %         | ANY      | mysql_native_password |
+-------------+-----------+----------+-----------------------+

To make existing database accounts use SSL, run the following SQL statement:

alter user 'root'@'localhost' require ssl;

Connect to MariaDB using SSL

Connecting to MariaDB using SSL creates a safe, encrypted connection between your computer and the database. This protects your data as it travels, making sure it stays private and secure during transfer.

Database tools require SSL to be enabled for connections to function correctly, ensuring secure data transfer.

The process is now complete.

Conclusion:

• Implementing a self-signed SSL certificate for MariaDB strengthens security by encrypting data transmitted between the server and clients.
• Following the steps outlined, you can successfully create, configure, and validate SSL connections for your MariaDB database.
• Enforcing SSL for all user connections ensures that sensitive information remains secure from potential eavesdropping.
• Regularly check and manage SSL certificates to maintain a secure database environment and avoid potential disruptions.
• Consider moving to a trusted certificate authority (CA) for production environments to enhance security further.