使用 Nginx 和 SNI 时未知主机的回退配置？

Question

当我的 Nginx 服务器被要求访问一个它不知道的站点时，谁能告诉我如何配置默认主机响应？我试过了：

server {
       listen 443 default_server;
       listen [::]:443 default_server;

       server_name _;

       return 444;
}

这只会导致所有其他站点导致 'unexpectedly closed the connection' 错误。

请注意，我没有计划支持旧版 https 客户端（那些不知道 SNI 的客户端）。

我正在使用 Nginx 1.14.0

Answer 1

通过浏览网络，答案似乎是您需要创建一个自签名证书，然后将其应用到默认主机。没有人会相信这一点，但考虑到他们最终使用的是未处理的主机名，这可能无关紧要？

我按照Digital Ocean的说明操作，我将在这里总结一下（内容太多无法包含全部内容）：

创建自签名证书
生成 dhparam 文件
配置 'default' 主机以在 https 配置（端口 443）中引用该主机

正在生成 dhparm 文件（需要一段时间）：

sudo openssl dhparam -out /etc/ssl/certs/dhparam.pem 2048

默认主机的 443 配置：

server {
       listen 443 default_server;
       listen [::]:443 default_server;

       include snippets/self-signed.conf;
       include snippets/ssl-params.conf;

       server_name _;

        root /var/www/html;

        # Add index.php to the list if you are using PHP
        index index.html index.htm index.nginx-debian.html;

        server_name _;

        location / {
                ssi on;
                # First attempt to serve request as file, then
                # as directory, then fall back to displaying a 404.
                try_files $uri $uri/ =404;
        }
}

ssl-signed.conf文件内容：

ssl_certificate /etc/ssl/certs/nginx-selfsigned.crt;
ssl_certificate_key /etc/ssl/private/nginx-selfsigned.key;

ssl-params.conf文件内容：

# from https://cipherli.st/

# and https://raymii.org/s/tutorials/Strong_SSL_Security_On_nginx.html

ssl_protocols TLSv1 TLSv1.1 TLSv1.2;
ssl_prefer_server_ciphers on;
ssl_ciphers "EECDH+AESGCM:EDH+AESGCM:AES256+EECDH:AES256+EDH";
ssl_ecdh_curve secp384r1;
ssl_session_cache shared:SSL:10m;
ssl_session_tickets off;
ssl_stapling on;
ssl_stapling_verify on;
resolver 8.8.8.8 8.8.4.4 valid=300s;
resolver_timeout 5s;
# Disable preloading HSTS for now.  You can use the commented out header line that includes
# the "preload" directive if you understand the implications.
#add_header Strict-Transport-Security "max-age=63072000; includeSubdomains; preload";
add_header Strict-Transport-Security "max-age=63072000; includeSubdomains";
add_header X-Frame-Options DENY;
add_header X-Content-Type-Options nosniff;

ssl_dhparam /etc/ssl/certs/dhparam.pem;

注意以上是使用 Nginx 1.14.0

测试的

使用 Nginx 和 SNI 时未知主机的回退配置？

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