Last updated: 2026-06-25

MySQL TLS/SSL Configuration Guide

This guide provides recommended TLS/SSL settings for MySQL to encrypt connections between clients and the database server. Encrypting database traffic prevents eavesdropping and man-in-the-middle attacks on sensitive data.

Prerequisites#

• MySQL 8.4 LTS or later (MySQL 8.0 reached end of life in April 2026)
• OpenSSL 1.1.1 or later
• SSL certificates (server certificate, private key, and CA certificate)

MySQL 8.4+ ships with TLS support enabled by default and auto-generates certificates on first startup. These self-signed certificates should be replaced with properly issued certificates for production use.

Generating Certificates#

MySQL 8.4+ automatically generates self-signed certificates on first startup if none exist. To generate certificates manually, use openssl commands or obtain certificates from a trusted CA for production use.

For production, use certificates from a CA such as Let's Encrypt, or your organization's internal CA.

Server Configuration#

Add the following settings to your MySQL configuration file under the [mysqld] section.

Path note: Debian/Ubuntu: /etc/mysql/mysql.conf.d/mysqld.cnf. RHEL: /etc/my.cnf.d/mysql-server.cnf (MySQL Community) or /etc/my.cnf. The main config (/etc/mysql/my.cnf or /etc/my.cnf) includes drop-in directories.

Protocol Versions#

Restrict connections to TLS 1.2 and TLS 1.3 only:

[mysqld]
tls_version=TLSv1.2,TLSv1.3

Cipher Suites#

Configure strong cipher suites for TLS 1.2:

[mysqld]
ssl_cipher=ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305

For TLS 1.3 cipher suites (MySQL 8.0.16+):

[mysqld]
tls_ciphersuites=TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256

Certificate Files#

[mysqld]
ssl_ca=/etc/mysql/ssl/ca.pem
ssl_cert=/etc/mysql/ssl/server-cert.pem
ssl_key=/etc/mysql/ssl/server-key.pem

Require Encrypted Connections#

Force all client connections to use TLS. Without this, clients can still connect without encryption:

[mysqld]
require_secure_transport=ON

Complete Server Configuration#

[mysqld]
# TLS protocol versions
tls_version=TLSv1.2,TLSv1.3

# TLS 1.2 cipher suites
ssl_cipher=ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305

# TLS 1.3 cipher suites
tls_ciphersuites=TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256

# Certificate files
ssl_ca=/etc/mysql/ssl/ca.pem
ssl_cert=/etc/mysql/ssl/server-cert.pem
ssl_key=/etc/mysql/ssl/server-key.pem

# Require encrypted connections
require_secure_transport=ON

Client Configuration#

Configure MySQL clients to use TLS by adding settings to the [client] section:

[client]
ssl_mode=REQUIRED
ssl_ca=/etc/mysql/ssl/ca.pem

Available ssl_mode values:

• REQUIRED - Connect with encryption, but don't verify the server certificate
• VERIFY_CA - Connect with encryption and verify the server certificate against the CA
• VERIFY_IDENTITY - Connect with encryption, verify the CA, and verify the server hostname matches the certificate (recommended)

For maximum security, use VERIFY_IDENTITY:

[client]
ssl_mode=VERIFY_IDENTITY
ssl_ca=/etc/mysql/ssl/ca.pem

Mutual TLS (mTLS)#

Standard TLS encrypts the connection and lets the client verify the server's certificate. Mutual TLS goes further: the server also verifies a certificate presented by the client. MySQL implements this through per-user REQUIRE clauses that control what each account must present to connect. This is optional; it is most useful for service accounts and automated clients where you can manage client certificates centrally.

Require a specific user to connect over TLS (encryption only, no certificate verification):

ALTER USER 'appuser'@'%' REQUIRE SSL;

To require the user to also present a valid client certificate signed by the server's CA:

ALTER USER 'appuser'@'%' REQUIRE X509;

For the strictest enforcement, require a specific certificate subject or issuer:

ALTER USER 'appuser'@'%' REQUIRE SUBJECT '/CN=appuser/O=Example Corp';

Client Configuration for mTLS#

Clients connecting to an account with REQUIRE X509 must provide a certificate and key:

[client]
ssl_mode=VERIFY_IDENTITY
ssl_ca=/etc/mysql/ssl/ca.pem
ssl_cert=/etc/mysql/ssl/client-cert.pem
ssl_key=/etc/mysql/ssl/client-key.pem

Or on the command line:

mysql -h db.example.com -u appuser -p \
    --ssl-ca=/etc/mysql/ssl/ca.pem \
    --ssl-cert=/etc/mysql/ssl/client-cert.pem \
    --ssl-key=/etc/mysql/ssl/client-key.pem

See RFC 8446 §4.3.2 for the TLS Certificate Request specification, and Wikipedia: Mutual authentication for a general overview.

Replication TLS#

To encrypt replication traffic between primary and replica servers, configure the replica to use TLS:

CHANGE REPLICATION SOURCE TO
    SOURCE_SSL = 1,
    SOURCE_SSL_CA = '/etc/mysql/ssl/ca.pem',
    SOURCE_SSL_CERT = '/etc/mysql/ssl/client-cert.pem',
    SOURCE_SSL_KEY = '/etc/mysql/ssl/client-key.pem',
    SOURCE_SSL_VERIFY_SERVER_CERT = 1;

The older CHANGE MASTER TO syntax was removed in MySQL 8.4. Use CHANGE REPLICATION SOURCE TO exclusively.

Security Notes#

The cipher suite and protocol configuration in this guide addresses the following known TLS vulnerabilities:

• POODLE (CVE-2014-3566, 2014): SSL 3.0 is disabled. TLS_FALLBACK_SCSV was added in OpenSSL 1.0.1j / 1.0.2 (October 2014); SSL 3.0 disabled by default in OpenSSL 1.1.0 (August 2016).
• BEAST (CVE-2011-3389, 2011): Mitigated by recommending TLS 1.2 as the minimum; AEAD-only ciphers eliminate the CBC padding oracle.
• CRIME (CVE-2012-4929, 2012): TLS compression is off by default in OpenSSL 1.1.0+; do not enable it.
• Lucky13 (2013): AEAD-only cipher list eliminates CBC padding timing side-channels entirely.
• FREAK (CVE-2015-0204, 2015): EXPORT-grade ciphers are excluded from the cipher string. Removed from OpenSSL 1.1.0 (August 2016).
• LOGJAM (CVE-2015-4000, 2015): Short-key DHE is excluded; only ECDHE key exchange is recommended.
• Sweet32 (CVE-2016-2183, 2016): 3DES is excluded from the cipher string.
• ROBOT (2017): Static RSA key exchange is excluded; only ECDHE is recommended.
• Downgrade attacks: TLS_FALLBACK_SCSV prevents protocol version rollback.
• Renegotiation injection (CVE-2009-3555, 2009): Secure renegotiation is enforced by default in OpenSSL 0.9.8m+; TLS 1.3 removes renegotiation entirely.

The following are not addressable through TLS configuration alone:

• Heartbleed (CVE-2014-0160, 2014): A memory disclosure bug in OpenSSL 1.0.1 through 1.0.1f. Fixed in OpenSSL 1.0.1g (April 7, 2014). Addressed by patching OpenSSL, not by TLS configuration.
• BREACH (CVE-2013-3587, 2013): Not applicable. BREACH targets HTTP-level response compression; the MySQL wire protocol does not involve HTTP.
• DROWN (CVE-2016-0800, 2016): Requires SSLv2 to be enabled on any server sharing the same private key. Ensure SSLv2 is disabled on all services that use the same certificate and key pair.

Verification#

After restarting MySQL, verify TLS is active:

mysql -u root -p -e "SHOW VARIABLES LIKE '%ssl%';"
mysql -u root -p -e "SHOW VARIABLES LIKE 'tls_version';"

Check the current connection's encryption status:

mysql -u root -p -e "SHOW SESSION STATUS LIKE 'Ssl_cipher';"

This should return a cipher name like TLS_AES_256_GCM_SHA384 confirming the connection is encrypted.