WordPress MySQL SSL dropin. Place in wp-content/db.php

<?php

class dd32_wpdb_ssl extends wpdb {
    /**
     * Connect to and select database
     * This is a COPY of the WordPress function as of r19773
     * Alteration: Adds the MySQL SSL arg.
     */
    function db_connect() {

        $this->is_mysql = true;

        if ( WP_DEBUG ) {
            $this->dbh = mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, true, MYSQL_CLIENT_SSL );
        } else {
            $this->dbh = @mysql_connect( $this->dbhost, $this->dbuser, $this->dbpassword, true, MYSQL_CLIENT_SSL );
        }

        if ( !$this->dbh ) {
            if ( ! function_exists( 'wp_load_translations_early' ) ) // only 3.4+ gets the wonderful error messages, everyone else, you just die
                die( 'Error establishing database connection. Goodbye.' );

            $this->bail( sprintf( __( "
<h1>Error establishing a database connection</h1>
<p>This either means that the username and password information in your <code>wp-config.php</code> file is incorrect or we can't contact the database server at <code>%s</code>. This could mean your host's database server is down.</p>
<ul>
    <li>Are you sure you have the correct username and password?</li>
    <li>Are you sure that you have typed the correct hostname?</li>
    <li>Are you sure that the database server is running?</li>
</ul>
<p>If you're unsure what these terms mean you should probably contact your host. If you still need help you can always visit the <a href='http://wordpress.org/support/'>WordPress Support Forums</a>.</p>
" ), $this->dbhost ), 'db_connect_fail' );

            return;
        }

        $this->set_charset( $this->dbh );

        $this->ready = true;

        $this->select( $this->dbname, $this->dbh );
    }
}
$wpdb = new dd32_wpdb_ssl( DB_USER, DB_PASSWORD, DB_NAME, DB_HOST );