一、安裝certbot客戶端

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

二、生成證書

./certbot-auto certonly --standalone --email 郵箱地址 -d 域名1 -d 域名2 ...

三、查看生成的證書

tree /etc/letsencrypt/live/

四、apache配置文件 httpd-ssl.conf

<VirtualHost *:443>
DocumentRoot "路徑"
ServerName 域名
ServerAdmin 郵箱
ErrorLog "路徑/logs/error_log"
TransferLog "路徑/logs/access_log"
SSLEngine on
SSLCertificateFile "/etc/letsencrypt/live/證書域名/fullchain.pem"
SSLCertificateKeyFile "/etc/letsencrypt/live/證書域名/privkey.pem"
<FilesMatch "\.(cgi|shtml|phtml|php)$">
    SSLOptions +StdEnvVars
</FilesMatch>
<Directory "路徑">
    SetOutputFilter DEFLATE
    Options FollowSymLinks
    AllowOverride All
    Order allow,deny
    Allow from all
    DirectoryIndex index.html index.php
</Directory>
BrowserMatch "MSIE [2-5]" \
         nokeepalive ssl-unclean-shutdown \
         downgrade-1.0 force-response-1.0
CustomLog "路徑/logs/ssl_request_log" \
          "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
</VirtualHost>  

五、證書續(xù)簽
Let’s Encrypt 生成的免費(fèi)證書為3個(gè)月時(shí)間

./certbot-auto renew