SSL/TLS配置指南

TLS版本支持

版本状态建议
TLS 1.3✓ Current启用——最快最安全
TLS 1.2⚠ Legacy为兼容性启用(2015年后客户端)
TLS 1.1✗ Deprecated禁用——2020年起浏览器不支持
TLS 1.0✗ Deprecated禁用——易受POODLE、BEAST攻击
SSL 2/3✗ Insecure永不启用

Nginx最佳TLS配置

server {
    listen 443 ssl http2;
    server_name example.com;

    ssl_certificate     /etc/letsencrypt/live/example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/example.com/privkey.pem;

    # TLS versions
    ssl_protocols TLSv1.2 TLSv1.3;

    # Cipher suites (TLS 1.2 fallback)
    ssl_ciphers ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384;
    ssl_prefer_server_ciphers off;  # Let client pick in TLS 1.3

    # Session resumption
    ssl_session_timeout 1d;
    ssl_session_cache shared:SSL:10m;
    ssl_session_tickets off;

    # OCSP Stapling
    ssl_stapling on;
    ssl_stapling_verify on;
    resolver 8.8.8.8 valid=300s;

    # HSTS (enable after testing)
    add_header Strict-Transport-Security "max-age=63072000; includeSubDomains; preload" always;
}

Let's Encrypt配置(Certbot)

# Install certbot
sudo apt install certbot python3-certbot-nginx

# Obtain certificate (auto-configures nginx)
sudo certbot --nginx -d example.com -d www.example.com

# Test auto-renewal
sudo certbot renew --dry-run

# Cron job (auto-renewal every 12h)
0 */12 * * * certbot renew --quiet --post-hook "nginx -s reload"

SSL Labs评分要求

评级要求
A+HSTS预加载、TLS 1.2+、仅强密码套件、OCSP装订
ATLS 1.2+、无弱密码、有效证书、HSTS
B启用TLS 1.0/1.1或弱密码套件
F证书过期、严重漏洞、启用SSL 3.0