# Gondulf IndieAuth Server - nginx Configuration
# TLS termination, reverse proxy, rate limiting, and security headers

# Rate limiting zones
limit_req_zone $binary_remote_addr zone=gondulf_auth:10m rate=10r/s;
limit_req_zone $binary_remote_addr zone=gondulf_token:10m rate=20r/s;
limit_req_zone $binary_remote_addr zone=gondulf_general:10m rate=30r/s;

# Upstream backend
upstream gondulf_backend {
    server gondulf:8000;
    keepalive 32;
}

# HTTP server - redirect to HTTPS
server {
    listen 80;
    listen [::]:80;
    server_name auth.example.com;  # CHANGE THIS to your domain

    # Allow Let's Encrypt ACME challenges
    location /.well-known/acme-challenge/ {
        root /var/www/certbot;
    }

    # Redirect all other HTTP traffic to HTTPS
    location / {
        return 301 https://$server_name$request_uri;
    }
}

# HTTPS server
server {
    listen 443 ssl http2;
    listen [::]:443 ssl http2;
    server_name auth.example.com;  # CHANGE THIS to your domain

    # SSL/TLS configuration
    ssl_certificate /etc/nginx/ssl/fullchain.pem;
    ssl_certificate_key /etc/nginx/ssl/privkey.pem;

    # Modern TLS configuration
    ssl_protocols TLSv1.2 TLSv1.3;
    ssl_ciphers 'ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384';
    ssl_prefer_server_ciphers off;

    # SSL session cache
    ssl_session_cache shared:SSL:10m;
    ssl_session_timeout 10m;

    # OCSP stapling
    ssl_stapling on;
    ssl_stapling_verify on;
    resolver 8.8.8.8 8.8.4.4 valid=300s;
    resolver_timeout 5s;

    # Security headers
    add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
    add_header X-Frame-Options "DENY" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header X-XSS-Protection "1; mode=block" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
    # CSP will be set by the application

    # Logging
    access_log /var/log/nginx/gondulf_access.log combined;
    error_log /var/log/nginx/gondulf_error.log warn;

    # Client request limits
    client_max_body_size 1M;
    client_body_timeout 10s;
    client_header_timeout 10s;

    # Authorization endpoint - stricter rate limiting
    location ~ ^/(authorize|auth) {
        limit_req zone=gondulf_auth burst=20 nodelay;
        limit_req_status 429;

        proxy_pass http://gondulf_backend;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Port $server_port;
        proxy_set_header Connection "";

        # Proxy timeouts
        proxy_connect_timeout 10s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
    }

    # Token endpoint - moderate rate limiting
    location /token {
        limit_req zone=gondulf_token burst=40 nodelay;
        limit_req_status 429;

        proxy_pass http://gondulf_backend;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Port $server_port;
        proxy_set_header Connection "";

        proxy_connect_timeout 10s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;
    }

    # Health check endpoint - no rate limiting, no logging
    location /health {
        access_log off;
        proxy_pass http://gondulf_backend;
        proxy_http_version 1.1;
        proxy_set_header Connection "";
    }

    # All other endpoints - general rate limiting
    location / {
        limit_req zone=gondulf_general burst=60 nodelay;
        limit_req_status 429;

        proxy_pass http://gondulf_backend;
        proxy_http_version 1.1;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        proxy_set_header X-Forwarded-Host $host;
        proxy_set_header X-Forwarded-Port $server_port;
        proxy_set_header Connection "";

        proxy_connect_timeout 10s;
        proxy_send_timeout 30s;
        proxy_read_timeout 30s;

        # Buffer settings
        proxy_buffering on;
        proxy_buffer_size 4k;
        proxy_buffers 8 4k;
    }
}