17.3.1 Setting Up Replication to Use Encrypted Connections

ssl_ca: The path name of the Certificate Authority (CA) certificate file. (ssl_capath is similar but specifies the path name of a directory of CA certificate files.)

ssl_cert: The path name of the server public key certificate file. This certificate can be sent to the client and authenticated against the CA certificate that it has.

ssl_key: The path name of the server private key file.

To name the replica's certificate and SSL private key files using CHANGE REPLICATION SOURCE TO (CHANGE MASTER TO), add the appropriate SOURCE_SSL_xxx (MASTER_SSL_xxx) options, like this:

-> SOURCE_SSL_CA = 'ca_file_name',
    -> SOURCE_SSL_CAPATH = 'ca_directory_name',
    -> SOURCE_SSL_CERT = 'cert_file_name',
    -> SOURCE_SSL_KEY = 'key_file_name',

These options correspond to the --ssl-xxx options with the same names, as described in Command Options for Encrypted Connections. For these options to take effect, SOURCE_SSL=1 must also be set. For a replication connection, specifying a value for either of SOURCE_SSL_CA or SOURCE_SSL_CAPATH corresponds to setting --ssl-mode=VERIFY_CA. The connection attempt succeeds only if a valid matching Certificate Authority (CA) certificate is found using the specified information.

To activate host name identity verification, add the SOURCE_SSL_VERIFY_SERVER_CERT option, like this:

-> SOURCE_SSL_VERIFY_SERVER_CERT=1,

This option corresponds to the --ssl-verify-server-cert option, which is deprecated in MySQL 5.7 and removed in MySQL 8.0. For a replication connection, specifying MASTER_SSL_VERIFY_SERVER_CERT=1 corresponds to setting --ssl-mode=VERIFY_IDENTITY, as described in Command Options for Encrypted Connections. For this option to take effect, SOURCE_SSL=1 must also be set. Host name identity verification does not work with self-signed certificates.

To activate certificate revocation list (CRL) checks, add the SOURCE_SSL_CRL or SOURCE_SSL_CRLPATH option, as shown here:

-> SOURCE_SSL_CRL = 'crl_file_name',
    -> SOURCE_SSL_CRLPATH = 'crl_directory_name',

These options correspond to the --ssl-xxx options with the same names, as described in Command Options for Encrypted Connections. If they are not specified, no CRL checking takes place.

To specify lists of ciphers, ciphersuites, and encryption protocols permitted by the replica for the replication connection, use the SOURCE_SSL_CIPHER, SOURCE_TLS_VERSION, and SOURCE_TLS_CIPHERSUITES options, like this:

-> SOURCE_SSL_CIPHER = 'cipher_list',
    -> SOURCE_TLS_VERSION = 'protocol_list',
    -> SOURCE_TLS_CIPHERSUITES = 'ciphersuite_list',

The protocols, ciphers, and ciphersuites that you can specify in these lists depend on the SSL library used to compile MySQL. For information about the formats, the permitted values, and the defaults if you do not specify the options, see Section 6.3.2, “Encrypted Connection TLS Protocols and Ciphers”.

After the source information has been updated, start the replication process on the replica, like this:

mysql> START SLAVE;

Beginning with MySQL 8.0.22, START REPLICA is preferred, as shown here:

mysql> START REPLICA;

You can use the SHOW REPLICA STATUS (prior to MySQL 8.0.22, SHOW SLAVE STATUS) statement to confirm that an encrypted connection was established successfully.

Requiring encrypted connections on the replica does not ensure that the source requires encrypted connections from replicas. If you want to ensure that the source only accepts replicas that connect using encrypted connections, create a replication user account on the source using the REQUIRE SSL option, then grant that user the REPLICATION SLAVE privilege. For example:

mysql> CREATE USER 'repl'@'%.example.com' IDENTIFIED BY 'password'
    -> REQUIRE SSL;
mysql> GRANT REPLICATION SLAVE ON *.*
    -> TO 'repl'@'%.example.com';

If you have an existing replication user account on the source, you can add REQUIRE SSL to it with this statement:

mysql> ALTER USER 'repl'@'%.example.com' REQUIRE SSL;