Lab — Check Your Privacy Score

curl -I https://example.com: your client opens TCP/443, completes TLS to that name, and prints response headers (HEAD-style). You want: a successful TLS verify, a status (200/301/302/…), and any Strict-Transport-Security. You are not attacking example.com. You are reading the envelope stamp. A certificate error here is a finding about YOUR trust store or middlebox — stop, do not -k to "make the lab pass" on a real site. Public IP echo (ifconfig.me / icanhazip.com / api.ipify.org): the service sees the source address of YOUR TCP connection and prints it back. That is the address the internet sees for you right now — home NAT, café NAT, or VPN server, depending on what is up. It is not someone else's IP. Do not iterate the subnet. Do not mass-query. One GET is enough. dig example.com +short or nslookup example.com: YOUR configured resolver answers with A/AAAA (and maybe CNAME). That tells you which DNS you are actually using — ISP, router, tunnel DNS, or a DoH stub. It does not give you permission to zone-transfer, to brute names, or to query internal hostnames of a company you do not own. Stick to example.com or a name you already type in the browser every day.

The browser half of the score is not a command. Open YOUR browser: is third-party cookie blocking / tracking protection on? Does https://example.com show a padlock (or equivalent) without a warning? Those two questions close the loop with lessons 1–3. A perfect curl and a browser that still allows all cookies is a mid score, not a win. Write both.

Run the block on a machine you administer (Windows: WSL or native curl.exe if present; macOS/Linux: Terminal). Create the lab directory first so the redirect cannot fail halfway. After commands, open the browser you hardened in lesson 1. Visit https://example.com — padlock, no warning. Note tracking protection. Then score. Healthy output is still a lab: write "rungs passed." Do not invent extra targets because everything succeeded.

mkdir -p "$HOME/cyberlium-lab"

echo '=== curl -I https://example.com ==='
curl -I --connect-timeout 10 https://example.com

echo '=== curl -I http://example.com ==='
curl -I --connect-timeout 10 http://example.com

echo '=== public IP (self) ==='
curl -sS --max-time 10 https://ifconfig.me; echo

curl -sS --max-time 10 https://icanhazip.com
curl -sS --max-time 10 https://api.ipify.org; echo

echo '=== DNS ==='
dig example.com +short 2>/dev/null || nslookup example.com

{
  echo "date: $(date -Iseconds 2>/dev/null || date)"
  echo "=== curl HTTPS ==="
  echo "tls_ok_no_warning: yes/no"
  echo "http_status:"
  echo "hsts_present: yes/no"
  echo "=== public IP (self, optional) ==="
  echo "public_ip: (or skipped)"
  echo "looks_like: home_nat / cafe_nat / vpn_egress / unknown"
  echo "=== DNS ==="
  echo "resolver_tool: dig / nslookup / Resolve-DnsName"
  echo "name_queried: example.com"
  echo "answers:"
  echo "=== browser checklist ==="
  echo "third_party_cookies_or_tracking_blocked: yes/no"
  echo "https_padlock_on_example: yes/no"
  echo "https_only_mode: yes/no"
  echo "=== score (1 point each, max 6) ==="
  echo "1_https_tls_ok:"
  echo "2_hsts_or_http_redirect_noted:"
  echo "3_public_ip_recorded_or_honestly_skipped:"
  echo "4_dns_answer_recorded:"
  echo "5_browser_tracker_control_on:"
  echo "6_padlock_without_clickthrough:"
  echo "total:"
  echo "one_improvement_next: (DoH / VPN on untrusted Wi-Fi / banking profile / permissions review)"
  echo "ethics: did not scan other devices, did not capture café guests"
} > "$HOME/cyberlium-lab/privacy-score.txt"
chmod 600 "$HOME/cyberlium-lab/privacy-score.txt"

You measured what YOUR connection reveals: TLS to a name you may query, the public IP the world sees for you (if you chose to look), the resolver answer, and whether the browser still helps trackers. The score is a baseline for the next café, not a trophy for mapping a room. Next — Quiz — Safe Browsing — APPLY browser isolation, VPN honesty, public-Wi-Fi ethics, and this lab's commands, then Module 4 starts with Social Media Privacy.