# nginx 1.20.x

load_module modules/ngx_http_brotli_static_module.so;

worker_processes auto;
worker_rlimit_nofile 16384;

events {
    worker_connections 4096;
}

http {
    include mime.types;
    default_type application/octet-stream;

    charset utf-8;

    sendfile on;
    sendfile_max_chunk 512k;
    tcp_nopush on;
    keepalive_timeout 3m;
    server_tokens off;
    msie_padding off;

    client_max_body_size 1k;
    client_body_buffer_size 1k;
    client_header_buffer_size 1k;
    large_client_header_buffers 4 4k;
    http2_recv_buffer_size 128k;

    client_body_timeout 30s;
    client_header_timeout 30s;
    send_timeout 30s;

    http2_max_concurrent_streams 32;
    limit_conn_status 429;
    limit_conn_zone $binary_remote_addr zone=addr:10m;
    limit_conn addr 256;

    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256;
    ssl_prefer_server_ciphers on;
    ssl_conf_command Options PrioritizeChaCha;

    ssl_certificate /etc/letsencrypt/live/matrix.grapheneos.org/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/matrix.grapheneos.org/privkey.pem;

    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 1d;
    # maintained by nginx-rotate-session-ticket-keys in ramfs
    ssl_session_ticket_key session-ticket-keys/4.key;
    ssl_session_ticket_key session-ticket-keys/3.key;
    ssl_session_ticket_key session-ticket-keys/2.key;
    ssl_session_ticket_key session-ticket-keys/1.key;
    ssl_buffer_size 4k;

    ssl_trusted_certificate /etc/letsencrypt/live/matrix.grapheneos.org/chain.pem;
    ssl_stapling on;
    ssl_stapling_verify on;
    # maintained by certbot-ocsp-fetcher
    ssl_stapling_file ocsp-cache/matrix.grapheneos.org.der;

    log_format main '$remote_addr - $remote_user [$time_local] '
                    '"$request_method $scheme://$host$request_uri $server_protocol" $status $body_bytes_sent '
                    '"$http_referer" "$http_user_agent"';
    access_log /var/log/nginx/access.log main buffer=64k flush=1m;
    error_log /var/log/nginx/error.log;
    log_not_found off;

    gzip_proxied any;
    gzip_vary on;

    if_modified_since before;

    aio threads;
    # temporarily disabled since it appears to uncover a bug with how nginx and synapse interact
    #aio_write on;

    upstream backend {
        server [::1]:8008 fail_timeout=1s;
    }

    server {
        listen 80 backlog=4096;
        listen [::]:80 backlog=4096;
        server_name matrix.grapheneos.org element.grapheneos.org;

        root /var/empty;

        return 301 https://$host$request_uri;
    }

    server {
        listen 443 ssl http2 backlog=4096;
        listen [::]:443 ssl http2 backlog=4096;
        server_name matrix.grapheneos.org;

        root /var/empty;

        include snippets/security-headers.conf;
        add_header Cross-Origin-Resource-Policy "same-origin" always;
        add_header Content-Security-Policy "font-src 'none'; manifest-src 'none'; object-src 'none'; script-src 'none'; style-src 'none'; frame-ancestors 'none'; block-all-mixed-content" always;
        # obsolete and replaced with Content-Security-Policy frame-ancestors 'none'
        add_header X-Frame-Options "DENY" always;

        location = / {
            return 301 https://grapheneos.org/articles/grapheneos-servers#matrix.grapheneos.org;
        }

        location ~ ^(/_matrix|/_synapse/client) {
            # remove security headers that are statically set to the strictest possible values below
            proxy_hide_header Referrer-Policy;
            proxy_hide_header X-Frame-Options;

            include snippets/security-headers.conf;
            add_header Cross-Origin-Resource-Policy "cross-origin" always;
            add_header Content-Security-Policy "font-src 'none'; manifest-src 'none'; object-src 'none'; script-src 'none'; style-src 'none'; frame-ancestors 'none'; block-all-mixed-content" always;
            # obsolete and replaced with Content-Security-Policy frame-ancestors 'none'
            add_header X-Frame-Options "DENY" always;
            add_header X-Robots-Tag "none";

            proxy_pass http://backend;
            proxy_set_header X-Forwarded-For $remote_addr;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_set_header Host $host;
            proxy_read_timeout 600s;

            client_max_body_size 100m;
            client_body_buffer_size 16k;
        }

        location / {
            return 404;
        }
    }

    server {
        listen 443 ssl http2;
        listen [::]:443 ssl http2;
        server_name element.grapheneos.org;

        root /srv/element.grapheneos.org;

        include snippets/security-headers.conf;
        add_header Cross-Origin-Resource-Policy "cross-origin" always;
        add_header Content-Security-Policy "font-src 'self'; manifest-src 'self'; object-src 'none'; script-src 'self' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; frame-ancestors 'self'; block-all-mixed-content" always;
        # obsolete and replaced with Content-Security-Policy frame-ancestors 'self'
        add_header X-Frame-Options "SAMEORIGIN" always;
        add_header X-Robots-Tag "none";

        location ~ '\.(css|html|ico|js|json|map|svg|txt|wasm|xml)$' {
            gzip_static on;
            brotli_static on;
        }
    }

    server {
        listen 127.0.0.1:81;
        listen [::1]:81;

        root /var/empty;

        location = /nginx_status {
            stub_status;
            access_log off;
        }

        location / {
            return 404;
        }
    }
}