选择：选用Let’s Encrypt的免费证书，且发布的 ACME v2 现已正式支持通配符HTTPS证书
坑在前面：
申请证书填写域名*.wyr.com时，使用https://m.dev.wyr.com 显示证书无效，换成*.dev.wyr.com后问题解决。
#####即，域名不能跨级申请证书
如果有小伙伴测试结果有出入，请告诉我（benny）。
目录
安装
# 下载
wget https://dl.eff.org/certbot-auto
# 设为可执行权限
chmod 755 certbot-auto
申请证书
# 注xxx.com请根据自己的域名自行更改
./certbot-auto --server https://acme-v02.api.letsencrypt.org/directory -d "*.xxx.com" --manual --preferred-challenges dns-01 certonly
执行完这一步之后，会下载一些需要的依赖，稍等片刻之后，会提示输入邮箱
邮箱很重要，主要用于安全提醒，以及续期提醒
Complete!
Creating virtual environment...
Installing Python packages...
Installation succeeded.
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator manual, Installer None
Enter email address (used for urgent renewal and security notices) (Enter 'c' to
- cancel):
+ cancel): 这里填写邮箱地址
-------------------------------------------------------------------------------
Please read the Terms of Service at
https://letsencrypt.org/documents/LE-SA-v1.2-November-15-2017.pdf. You must
agree in order to register with the ACME server at
https://acme-v02.api.letsencrypt.org/directory
-------------------------------------------------------------------------------
- (A)gree/(C)ancel:
+ (A)gree/(C)ancel: A
-------------------------------------------------------------------------------
Would you be willing to share your email address with the Electronic Frontier
Foundation, a founding partner of the Let's Encrypt project and the non-profit
organization that develops Certbot? We'd like to send you email about EFF and
our work to encrypt the web, protect its users and defend digital rights.
-------------------------------------------------------------------------------
- (Y)es/(N)o:
+ (Y)es/(N)o: Y
Obtaining a new certificate
Performing the following challenges:
dns-01 challenge for showgold.com
-------------------------------------------------------------------------------
NOTE: The IP of this machine will be publicly logged as having requested this
certificate. If you're running certbot in manual mode on a machine that is not
your server, please ensure you're okay with that.
Are you OK with your IP being logged?
-------------------------------------------------------------------------------
- (Y)es/(N)o:
+ (Y)es/(N)o: Y
-------------------------------------------------------------------------------
Please deploy a DNS TXT record under the name
+ _acme-challenge.xxx.com
with the following value:
+ VBsfRHG______4t_drxcEFQlyOS0puAlJFypAYQTA
Before continuing, verify the record is deployed.
-------------------------------------------------------------------------------
这步啥意思？
1、添加子域名 _acme-challenge.xxx.com（比如，开发环境添加_acme-challenge.dev.lottery666.com）
2、解析记录
-------------------------------------------------------------------------------
Press Enter to Continue
+ 不要心急着按回车，先执行dig _acme-challenge.xxx.com txt确认解析记录是否生效，生效之后再回去按回车确认
Waiting for verification...
IMPORTANT NOTES:
- Congratulations! Your certificate and chain have been saved at:
+ /etc/letsencrypt/live/xxx.com/fullchain.pem
Your key file has been saved at:
+ /etc/letsencrypt/live/xxx.com/privkey.pem
Your cert will expire on 2018-06-13. 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
注意：
申请通配符证书是要经过DNS认证的，按照提示，前往域名后台添加对应的DNS TXT记录。
添加之后，不要心急着按回车，先执行 dig xxxx.xxx.com txt确认解析记录是否生效，生效之后再回去按回车确认
看到 Congratulations 你就大功告成了！
续期HTTPS证书
certbot-auto renew
免费的证书有效期为90天，所以需要定期更新，如果怕忘记可以设置定时器
1 4 1 * * /tmp/certbot-auto renew >> /data/logs/crontab/ssl.log
nginx应用该证书的例子
server {
server_name xxx.com;
listen 443 http2 ssl;
ssl on;
ssl_certificate /etc/letsencrypt/live/xxx.com/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/xxx.com/privkey.pem;
location / {
proxy_pass http://127.0.0.1:6666;
}
}
无法应用到主域名
如需把主域名也增加到证书的覆盖范围，请在开始申请证书步骤的那个指令把主域名也加上-d "xxx.com"，如下：
需要注意的是，这样的话需要修改两次解析记录
./certbot-auto --server https://acme-v02.api.letsencrypt.org/directory -d "*.xxx.com" -d "xxx.com" --manual --preferred-challenges dns-01 certonly
#The END !!!
#####>>>>>下面的方法没有实践，有兴趣的小伙伴可以自行练习<<<<<
certbot-nginx
安装 EPEL 仓库
首先要安装 Let's Encrypt 证书用的工具，这个可以在CentOS 的 EPEL 仓库里找到它，在找到它之前，先检查是否存在 EPEL 源:
# 进入目录检查是否存在 EPEL 源，一般情况文件名称 epel.repo
cd /etc/yum.repos.d/
如果不存在可以直接安装
sudo yum install epel-release -y
安装签发证书工具
sudo yum install certbot-nginx -y
# 查看版本
certbot --version
# certbot 0.21.1
申请证书
报nginx命令不存在错误
sudo certbot --nginx
# Saving debug log to /var/log/letsencrypt/letsencrypt.log
# The nginx plugin is not working; there may be problems with your existing configuration.
# The error was: NoInstallationError()
# 如果你报上面错误运行下面，命令解决问题
which nginx # 查看目录
#输出 /usr/local/nginx/sbin/nginx
yum info nginx
解决方法
ln -s /usr/local/nginx/sbin/nginx /usr/bin/nginx
ln -s /usr/local/nginx/conf/ /etc/nginx
报nginx配置文件目录不对错误
sudo certbot --nginx
# Saving debug log to /var/log/letsencrypt/letsencrypt.log
# Error while running nginx -c /etc/nginx/nginx.conf -t.
# nginx: [emerg] open() "/etc/nginx/nginx.conf" failed (2: No such file or directory)
# nginx: configuration file /etc/nginx/nginx.conf test failed
# The nginx plugin is not working; there may be problems with your existing configuration.
# The error was: MisconfigurationError('Error while running nginx -c /etc/nginx/nginx.conf -t.\n\nnginx: [emerg] open() "/etc/nginx/nginx.conf" failed (2: No such file or directory)\nnginx: configuration file /etc/nginx/nginx.conf test failed\n',)
解决方法，这个解决方法就是让certbot认为你的，你的配置存在，并且将SSL配置写入你的nginx配置文件中，然后拷贝配置到你的默认 nginx 配置中。哈哈为了方便 nginx 启动不用指定配置，也没有看到 certbot 工具提供指定目录的命令，暂时我就这么解决吧。
# nginx 默认配置文件目录不 /etc/nginx/ 目录下，
# 需要拷贝/usr/local/nginx/conf目录下的全部文件
# 复制到/etc/nginx/目录下
cp -r /usr/local/nginx/conf/* /etc/nginx/
# 编辑开机启动将所有目录换成/etc/nginx/
vim /lib/systemd/system/nginx.service
cp /lib/systemd/system/nginx.service{,.bak}
# 测试配置是否正确
nginx -t -c /etc/nginx/nginx.conf
正确之后将nginx中的 SSL 配置复制到你的原来正在运行的配置中，在默认安装目录配置/usr/local/nginx/conf/。会在配置中生成如下内容，主要是复制这个。
{
ssl_certificate /etc/letsencrypt/live/chat.wangchujiang.com/fullchain.pem; # managed by Certbot
ssl_certificate_key /etc/letsencrypt/live/chat.wangchujiang.com/privkey.pem; # managed by Certbot
}
正式申请申请证书
首先运行证书生成命令，选择你要配置SSL证书的网站，这个是基于你网站已经在nginx中配置好了的情况。
sudo certbot --nginx certonly
# Saving debug log to /var/log/letsencrypt/letsencrypt.log
# Plugins selected: Authenticator nginx, Installer nginx
# Starting new HTTPS connection (1): acme-v01.api.letsencrypt.org
#
# Which names would you like to activate HTTPS for?
# -------------------------------------------------------------------------------
# 1: chat.wangchujiang.com
# 2: g.wangchujiang.com
# 3: pan.wangchujiang.com
# -------------------------------------------------------------------------------
# Select the appropriate numbers separated by commas and/or spaces, or leave input
# blank to select all options shown (Enter 'c' to cancel): 2
上面选择了g.wangchujiang.com生成证书，下面是验证过程，添加 certonly参数表示只生成证书。
# Obtaining a new certificate
# Performing the following challenges:
# tls-sni-01 challenge for g.wangchujiang.com
# Waiting for verification...
# Cleaning up challenges
#
# IMPORTANT NOTES:
# - Congratulations! Your certificate and chain have been saved at:
# /etc/letsencrypt/live/g.wangchujiang.com/fullchain.pem
# Your key file has been saved at:
# /etc/letsencrypt/live/g.wangchujiang.com/privkey.pem
# Your cert will expire on 2018-03-13. To obtain a new or tweaked
# version of this certificate in the future, simply run certbot
# again. To non-interactively renew *all* of your certificates, run
# "certbot 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
上面生成成功了，可以添加到 nginx 配置中，这下完事儿了，下面是一端nginx的配置实例。
配置nginx
# http 重定向到 https
server {
listen 80;
server_name g.wangchujiang.com;
rewrite ^ https://$http_host$request_uri? permanent;
# Enables or disables emitting nginx version on error pages and in the "Server" response header field.
server_tokens off;
}
# https 的配置
server {
listen 443 ssl;
server_name g.wangchujiang.com;
ssl_certificate /etc/letsencrypt/live/g.wangchujiang.com/fullchain.pem;
ssl_certificate_key /etc/letsencrypt/live/g.wangchujiang.com/privkey.pem;
# 禁止在header中出现服务器版本，防止黑客利用版本漏洞攻击
server_tokens off;
# 设置ssl/tls会话缓存的类型和大小。如果设置了这个参数一般是shared，buildin可能会参数内存碎片，默认是none，和off差不多，停用缓存。如shared:SSL:10m表示我所有的nginx工作进程共享ssl会话缓存，官网介绍说1M可以存放约4000个sessions。
ssl_session_cache shared:SSL:1m;
# 客户端可以重用会话缓存中ssl参数的过期时间，内网系统默认5分钟太短了，可以设成30m即30分钟甚至4h。
ssl_session_timeout 5m;
# 选择加密套件，不同的浏览器所支持的套件（和顺序）可能会不同。
# 这里指定的是OpenSSL库能够识别的写法，你可以通过 openssl -v cipher 'RC4:HIGH:!aNULL:!MD5'（后面是你所指定的套件加密算法） 来看所支持算法。
ssl_ciphers HIGH:!aNULL:!MD5;
# 设置协商加密算法时，优先使用我们服务端的加密套件，而不是客户端浏览器的加密套件。
ssl_prefer_server_ciphers on;
location / {
root html;
index index.html index.htm;
}
}