从teddysun大佬的一键LAMP脚本里看到了一个免费SSL的新选择Buypass Go SSL。和lets一样，不过申请的证书时间比lets长，有180天，而且也支持Certbot或acme.sh签发，官方提供API。
Demo地址：https://buypass.oregai.ru

官网英文教程：https://www.buypass.com/ssl/resources/go-ssl-technical-specification

下载Certbot

1.你也可以可以看Certbot官网https://certbot.eff.org/
2、执行命令

apt-get remove certbot
wget https://dl.eff.org/certbot-auto
chmod a+x certbot-auto

签发命令

1、签发命令

./certbot-auto register -m 'YOUR_EMAIL' --agree-tos --server 'https://api.buypass.com/acme/directory'
 
./certbot-auto certonly --standalone --email '邮箱' -d '域名' --server 'https://api.buypass.com/acme/directory'

2、输出结果 去目录找证书就行

IMPORTANT NOTES:
 - Congratulations! Your certificate and chain have been saved at:
   /etc/letsencrypt/live/buypass.oregai.ru/fullchain.pem
   Your key file has been saved at:
   /etc/letsencrypt/live/buypass.oregai.ru/privkey.pem
   Your cert will expire on 2019-06-29. To obtain a new or tweaked
   version of this certificate in the future, simply run certbot-auto
   again. To non-interactively renew *all* of your certificates, run
   "certbot-auto renew"
 - If you like Certbot, please consider supporting our work by:
 
   Donating to ISRG / Let's Encrypt:   https://letsencrypt.org/donate
   Donating to EFF:                    https://eff.org/donate-le

Myssl测试地址：https://myssl.com/buypass.oregai.ru
以上教程部分摘自可乐博客。理论讲常用的脚本acme.sh也可以实现这个功能，官方教程使用Certbot。