我有虚拟主机
<VirtualHost 10.10.10.10:80>
ServerAdmin webmaster@server.com
ServerName server.com
ServerAlias subdomain-a.server.com subdomain-b.server.com subdomain-c.server.com subdomain-d.server.com
DocumentRoot /srv/www/server.com/public_html/
</VirtualHost>
<VirtualHost 10.10.10.10:443>
ServerAdmin webmaster@server.com
ServerName server.com
ServerAlias subdomain-a.server.com subdomain-b.server.com subdomain-c.server.com subdomain-d.server.com
DocumentRoot /srv/www/server.com/public_html/
</VirtualHost>
我想强制访问者对子域-a 和子域-c 使用 https。subdomain-b 和 subdomain-d 的访问者可以使用 http 和 https。如何配置.htaccess?