2.8.6 Configuring SSL Library Support

An SSL library is required for support of encrypted connections, entropy for random number generation, and other encryption-related operations.

If you compile MySQL from a source distribution, CMake configures the distribution to use the installed OpenSSL library by default.

To compile using OpenSSL, use this procedure:

1. Ensure that OpenSSL 1.0.1 or newer is installed on your system. If the installed OpenSSL version is older than 1.0.1, CMake produces an error at MySQL configuration time. If it is necessary to obtain OpenSSL, visit http://www.openssl.org.

2. The WITH_SSL CMake option determines which SSL library to use for compiling MySQL (see Section 2.8.7, “MySQL Source-Configuration Options”). The default is -DWITH_SSL=system, which uses OpenSSL. To make this explicit, specify that option. For example:

   cmake . -DWITH_SSL=system

   That command configures the distribution to use the installed OpenSSL library. Alternatively, to explicitly specify the path name to the OpenSSL installation, use the following syntax. This can be useful if you have multiple versions of OpenSSL installed, to prevent CMake from choosing the wrong one:

   cmake . -DWITH_SSL=path_name

   Alternative OpenSSL system packages are supported by using WITH_SSL=openssl11 on EL7 or WITH_SSL=openssl3 on EL8. Authentication plugins, such as LDAP and Kerberos, are disabled since they do not support these alternative versions of OpenSSL.

3. Compile and install the distribution.

To check whether a mysqld server supports encrypted connections, examine the value of the tls_version system variable:

mysql> SHOW VARIABLES LIKE 'tls_version';
+---------------+-----------------+
| Variable_name | Value           |
+---------------+-----------------+
| tls_version   | TLSv1.2,TLSv1.3 |
+---------------+-----------------+

If the value contains TLS versions then the server supports encrypted connections, otherwise it does not.

For additional information, see Section 8.3.1, “Configuring MySQL to Use Encrypted Connections”.