通过Let's Encrypt申请免费https证书
通过Let’s Encrypt申请免费https证书。
环境：centos 7+apache/nginx
本文采用letsencrypt.org推荐Certbot ACME 方式获取证书。
获取 Certbot
访问 https://certbot.eff.org/，依提示选择环境。
本文为 https://certbot.eff.org/lets-encrypt/centosrhel7-apache，按提示安装。
安装步骤
1. 安装 EPEL (Extra Packages for Enterprise Linux)
yum -y install yum-utils
yum-config-manager --enable rhui-REGION-rhel-server-extras rhui-REGION-rhel-server-optional
2.安装Certbot
yum install certbot-apache
certbot --apache
3.开始申请证书
# 注xxxlab.cn请根据自己的域名自行更改
certbot -d "*.xxxlab.cn" -d xxxlab.cn --server https://acme-v02.api.letsencrypt.org/directory --manual --preferred-challenges dns certonly
申请过程交互如下：
Saving debug log to /var/log/letsencrypt/letsencrypt.log
Plugins selected: Authenticator manual, Installer nginx
Starting new HTTPS connection (1): acme-v02.api.letsencrypt.org
Obtaining a new certificate
Performing the following challenges:
dns-01 challenge for xxxlab.cn
dns-01 challenge for xxxlab.cn
-------------------------------------------------------------------------------
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
-------------------------------------------------------------------------------
Please deploy a DNS TXT record under the name (第一次在DNS上配置)
_acme-challenge.xxxlab.cn with the following value:
7rBRoMUcyphsdfdsfsfdfsaa3332rsdfsaOeMv1Tfpk-6phU
Before continuing, verify the record is deployed.
-------------------------------------------------------------------------------
Press Enter to Continue
-------------------------------------------------------------------------------
Please deploy a DNS TXT record under the name (第二次在DNS上配置并保留第一次配置)
_acme-challenge.xxxlab.cn with the following value:
FjPeO3aHA2GXXhAiknu4d0sfdsdf23r223uXIff--E4
Before continuing, verify the record is deployed.
-------------------------------------------------------------------------------
Press Enter to Continue
Waiting for verification...
Cleaning up challenges
IMPORTANT NOTES:
- Congratulations! Your certificate and chain have been saved at:
/etc/letsencrypt/live/xxxlab.cn/fullchain.pem
Your key file has been saved at:
/etc/letsencrypt/live/xxxlab.cn/privkey.pem
Your cert will expire on 2018-06-27. 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
注意过程需要两次在DNS上配置_acme-challenge.xxxlab.cn，其值如上所示。
使用dig测试
dig _acme-challenge.xxxlab.cn txt
结果如下：
......
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;_acme-challenge.xxxlab.cn. IN TXT
;; ANSWER SECTION:
_acme-challenge.xxxlab.cn. 86400 IN TXT "7rBRoMUcyphsdfdsfsfdfsaa3332rsdfsaOeMv1Tfpk-6phU"
_acme-challenge.xxxlab.cn. 86400 IN TXT "FjPeO3aHA2GXXhAiknu4d0sfdsdf23r223uXIff--E4"
.........
4. 测试及自动续订证书
测试自动续订证书
certbot renew --dry-run
如上述测试正常可通过定时器或其他方式自动执行如下命令
certbot renew
本步骤笔者未测试。
5. 部署用例
1) nginx
......
server {
server_name xxxlab.cn;
listen 443 http2 ssl;
ssl on;
ssl_certificate /etc/cert/xxxlab.cn/fullchain.pem;
ssl_certificate_key /etc/cert/xxxlab.cn/privkey.pem;
ssl_trusted_certificate /etc/cert/xxxlab.cn/chain.pem;
location / {
proxy_pass http://10.10.10.10:8080;
}
}
......
2)apache
.....
SSLEngine on
SSLProtocol all -SSLv2
SSLCertificateFile /etc/cert/xxxlab.cn/fullchain.pem
SSLCertificateKeyFile /etc/cert/xxxlab.cn/privkey.pem
......
使用http认证方式
上述是使用dns作为认证获取申请通配符证书，早期笔者是使用http认证方式在服务器下配置提示认证信息。命令如下
certbot certonly --email abanger@xxxlab.cn -d login.xxxlab.cn -a manual
邮件abanger@xxxlab.cn用于证书过期提示。
其他
- 申请的主机要可访问互联网，DNS要互联网可访问。
- xxxlab.cn是一个测试域名，请根据自己的域名自行更改。
- 为什么使用https,参考链接2有描述。
- 这样配置有没有引发其他安全问题，包括此开源软件隐患，欢迎大家讨论点击讨论
参考
Let’s Encrypt 给网站加 HTTPS 完全指南certbot
修订
- 2019-01-17 08:07:00 删除命令多余参数（郑先生提醒）