使用免费SSL证书让网站支持HTTPS访问

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我们使用的服务器是在公司内部,用联通送的ip,通过路由器隐射使得外网可以访问,我们在这个服务器搭建了很多工具,比如Gitlab,聊天工具,网盘等,访问都很麻烦,没有备案,都必须带上端口号访问对应的服务,据说80端口被封了,假设有了https就可以默认443端口,就不用带端口号了,通过https访问默认浏览器会给你带上443端口,下面是我使用 Let's Encrypt 提供的SSL证书,记录配置SSL的安装实践过程。

教程归档在我的Github中欢迎修正和Star

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

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;
  }
}