「干货分享」一键获取安全可信的HTTPS证书！-Eswlnk Blog
智能摘要 AI
文章介绍了如何使用Certbot获取Let's Encrypt的免费HTTPS证书。过去因认为静态内容无需HTTPS且申请证书麻烦，但现在Certbot简化了这一过程。Certbot是一个ACME客户端，支持通过ACME协议自动化签发证书。准备工作包括申请域名和配置VPS。通过Docker或命令行可一键获取证书，选择认证方式后填写邮件信息并同意服务协议。成功获取证书后需配置在Web服务器中，并定期更新（90天有效期）。更新只需运行`certbot renew`命令。

之前因为觉得都是静态内容，所以没必要用HTTPS。主要是嫌申请HTTPS证书比较麻烦。现在可以使用命令行的certbot非常方便地获取Let’s Encrypt的免费证书。

Certbot简介

Certboot是一个ACME（自动化证书管理环境）客户端，这也是Let’s Encrypt官网推荐的签发证书的方式。它适用于对自己domain具有shell访问能力的情况，使用所谓的ACME协议来自动化地签发证书，很大程度上简化了证书签发的步骤。

「干货分享」一键获取安全可信的HTTPS证书！-Eswlnk Blog

准备工作

HTTPS的证书基于domain签发，所以事先需要准备如下工作：

  • 申请一个domain，例如：example.me.
  • 一台公网能够访问的VPS，将example.me解析为它的IP.

一键运行

可以从Github安装certbot，但文档中也给出了直接用Docker启动的方法，还是非常方便的。以下是示例代码：

Copy Codesudo docker run -it --rm --name certbot -v "/etc/letsencrypt:/etc/letsencrypt" -v "/var/lib/letsencrypt:/var/lib/letsencrypt" -p 80:80 certbot/certbot certonly

其中certonly是获取证书的命令，将80端口映射到本地是为了让ACME server来访问我们的VPS，以验证所有权。

填写信息

如果不加任何参数运行certonly，就会进入以下交互式界面：

Copy CodeSaving debug log to /var/log/letsencrypt/letsencrypt.log

How would you like to authenticate with the ACME CA?
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
1: Runs an HTTP server locally which serves the necessary validation files under
the /.well-known/acme-challenge/ request path. Suitable if there is no HTTP
server already running. HTTP challenge only (wildcards not supported).
(standalone)
2: Saves the necessary validation files to a .well-known/acme-challenge/
directory within the nominated webroot path. A seperate HTTP server must be
running and serving files from the webroot path. HTTP challenge only (wildcards
not supported). (webroot)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Select the appropriate number [1-2] then [enter] (press 'c' to cancel):

选项1是让certbot自己运行HTTP server来通过验证，而选项2则需要我们自己将文件放置在.well-known/acme-challenge/目录下来通过验证。如果不怕自己VPS的web服务中断的话，第1种方式还是比较方便的。

「干货分享」一键获取安全可信的HTTPS证书！-Eswlnk Blog

随后需要填写邮件信息和同意服务协议，如下所示：

Copy CodeEnter email address (used for urgent renewal and security notices)
 (Enter 'c' to cancel): alice@bob.com

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Please read the Terms of Service at
https://letsencrypt.org/documents/LE-SA-v1.3-September-21-2022.pdf. You must
agree in order to register with the ACME server. Do you agree?
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(Y)es/(N)o: Y

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Would you be willing, once your first certificate is successfully issued, 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 our work encrypting the web,
EFF news, campaigns, and ways to support digital freedom.
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
(Y)es/(N)o: N
Account registered.

接下来可以输入需要签发证书的domain，用逗号或是空格隔开。但不能使用通配符*。Certbot会在本地启动一个HTTP server，然后通知ACME server来访问对应的website，以验证domain的所有权。

Copy CodePlease enter the domain name(s) you would like on your certificate (comma and/or
space separated) (Enter 'c' to cancel): example.me
Requesting a certificate for example.me

Successfully received certificate.
Certificate is saved at: /etc/letsencrypt/live/example.me/fullchain.pem
Key is saved at:         /etc/letsencrypt/live/example.me/privkey.pem
This certificate expires on xxxx-xx-xx.
These files will be updated when the certificate renews.

到这里就签发完毕了，在host的/etc/letsencrypt/live/example.me/目录下就生成证书fullchain.pem和privkey.pem。然后可以将SSL证书配置在自己的web server中。

更新

用这种方式生成的证书有效期是90天，在过期之后需要进行更新（renew）操作。只需要将上述命令certonly改为renew即可，该命令会自动更新/etc/letsencrypt/live/目录下有效期少于30天的证书。