1、创建用户并开启ssl认证
CREATE USER 'remote_user'@'mysql_client_IP' IDENTIFIED BY 'password' REQUIRE SSL;

2、对已经存在的用户开启ssl
alter user 'xxx'@'%' require ssl; 

3、取消ssl验证: 
alter user 'safecheck'@'7.220.%' require none;