如何在 ssllabs.com 上得到 A+ ？

使用了 let’s encrypt 的证书之后，就想着去 https://www.ssllabs.com/ssltest/ 评个分。结果不理想，最多 B ，优化一下，最多 A ，怎么能弄个 A+ 呢？

参照：
https://mozilla.github.io/server-side-tls/ssl-config-generator/

然后执行：

openssl dhparam -out /etc/nginx/dhparam.pem 4096

生成 dhparam.pem 文件。

然后改 nginx 的配置文件如下：

server {
    listen 443 ssl http2;
    server_name www.mydomain.com;
    root /home/webdir/www.mydomain.com;
    index index.html index.htm index.php;

    ssl on;
    ssl_certificate /etc/letsencrypt/live/www.mydomain.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/www.mydomain.com/privkey.pem;

    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:50m;
    ssl_session_tickets off;
    ssl_dhparam dhparam.pem;

    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
    ssl_ciphers 'ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-S
HA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DH
E-RSA-AES256-SHA256:DHE-RSA-AES256-SHA:ECDHE-ECDSA-DES-CBC3-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA:!DSS';
    ssl_prefer_server_ciphers on;

    add_header Strict-Transport-Security max-age=15768000;

    ssl_stapling on;
    ssl_stapling_verify on;

    location ~ \.php$ {
        fastcgi_pass   127.0.0.1:9000;
        fastcgi_index  index.php;
        fastcgi_param  SCRIPT_FILENAME  $document_root$fastcgi_script_name;
        include        fastcgi_params;
    }
}

哈，再一试，果然 A+ 了。