从Apache迁移到Nginx后iFrame因混合内容问题无法加载

我正将网站从Apache迁移至Nginx，其中包含iFrame的页面（https://wpdemo.hotjoomlatemplates.com/）在Nginx上因混合内容问题无法加载iFrame，但iFrame的src已设置为HTTPS。该页面在Apache环境的VPS上可正常运行，无混合内容错误，且页面源码中也没有任何HTTP引用。

以下是我的Nginx配置：

server {
  listen 80;
  listen [::]:80;
  listen 443 quic;
  listen 443 ssl;
  listen [::]:443 quic;
  listen [::]:443 ssl;
  http2 on;
  http3 off;
  {{ssl_certificate_key}}
  {{ssl_certificate}}
  server_name wpdemo.hotjoomlatemplates.com;
  {{root}}

  {{nginx_access_log}}
  {{nginx_error_log}}

  if ($scheme != "https") {
    rewrite ^ https://$host$request_uri permanent;
  }

  location ~ /.well-known {
    auth_basic off;
    allow all;
  }

  {{settings}}

  location / {
    {{varnish_proxy_pass}}
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_hide_header X-Varnish;
    proxy_redirect off;
    proxy_max_temp_file_size 0;
    proxy_connect_timeout      720;
    proxy_send_timeout         720;
    proxy_read_timeout         720;
    proxy_buffer_size          128k;
    proxy_buffers              4 256k;
    proxy_busy_buffers_size    256k;
    proxy_temp_file_write_size 256k;
  }

  location ~* ^.+\.(css|js|jpg|jpeg|gif|png|ico|gz|svg|svgz|ttf|otf|woff|woff2|eot|mp4|ogg|ogv|webm|webp|zip|swf|map|mjs)$ {
    add_header Access-Control-Allow-Origin "*";
    add_header alt-svc 'h3=":443"; ma=86400';
    add_header X-Frame-Options "ALLOWALL";
    expires max;
    access_log off;
  }

  location ~ /\.(ht|svn|git) {
    deny all;
  }

  if (-f $request_filename) {
    break;
  }
}

server {
  listen 8080;
  listen [::]:8080;
  server_name wpdemo.hotjoomlatemplates.com;
  {{root}}

  include /etc/nginx/global_settings;

  try_files $uri $uri/ /index.php?$args;
  index index.php index.html;
  
  autoindex off;

  location ~ \.php$ {
    include fastcgi_params;
    fastcgi_intercept_errors on;
    fastcgi_index index.php;
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    try_files $uri =404;
    fastcgi_read_timeout 3600;
    fastcgi_send_timeout 3600;
    fastcgi_param HTTPS "on";
    fastcgi_param SERVER_PORT 443;
    fastcgi_pass 127.0.0.1:{{php_fpm_port}};
    fastcgi_param PHP_VALUE "{{php_settings}}";
  }

  if (-f $request_filename) {
    break;
  }
}

1. 清空Varnish缓存
   配置中启用了Varnish代理，可能缓存了旧的HTTP内容，执行命令清空缓存后再测试：

   varnishadm "ban req.url ~ .*"
   

2. 优化HTTPS强制跳转逻辑
   替换原配置中if ($scheme != "https")的判断，改用单独的server块实现强制跳转，避免逻辑漏洞：

   # 单独创建80端口的server块，替换原配置中对应的80监听逻辑
   server {
     listen 80;
     listen [::]:80;
     server_name wpdemo.hotjoomlatemplates.com;
     return 301 https://$host$request_uri;
   }
   

3. 添加HSTS头强制HTTPS访问
   在443端口的server块中添加HSTS头，强制浏览器始终使用HTTPS，避免潜在的HTTP fallback：

   add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;
   

4. 补充后端PHP的协议识别头
   在8080端口的php location块中添加X-Forwarded-Proto头，确保PHP应用正确识别请求协议：

   fastcgi_param X-Forwarded-Proto https;
   

5. 扫描页面实际响应内容
   即使源码无HTTP引用，动态生成的内容（如插件、主题输出）可能存在硬编码HTTP链接，用命令扫描：

   curl -s https://wpdemo.hotjoomlatemplates.com/ | grep -i "http://"
   

内容的提问来源于stack exchange，提问作者Milos Stankovic