feat(infra): hardening firewall + sysctl + ssh

- deny-by-default iptables/ip6tables: public cuma 22/80/443/4013, sisanya localhost + tailscale CGNAT; log FW-DROP rate-limited - persist via netfilter-persistent (rules.v4/v6) + /usr/local/bin/firewall.sh - sysctl hardening: syncookies, rp_filter, redirect off, kptr/dmesg restrict, protected links, somaxconn, tcp retries tuner - sshd: PasswordAuthentication no (fix 50-cloud-init.conf override), PermitRootLogin prohibit-password, MaxAuthTries 4, LoginGraceTime 30, X11Forwarding no
2026-08-02 20:22:49 +07:00
parent 500af023de
commit e6033c8b12
3 changed files with 126 additions and 0 deletions
@@ -0,0 +1,74 @@
+#!/bin/bash
+# ============================================================
+# firewall.sh — deny-by-default firewall untuk orangevps
+# Public: 22 (SSH), 80/443 (Caddy), 4013 (hermes dashboard)
+# Tailscale CGNAT 100.64/10: semua port (imrnes & node lain)
+# Localhost: semua
+# Sisanya: DROP + log
+# ============================================================
+set -e
+
+### IPv4 ###
+iptables -F
+iptables -X
+iptables -Z
+
+# Policy default DROP
+iptables -P INPUT DROP
+iptables -P FORWARD DROP
+iptables -P OUTPUT ACCEPT
+
+# Loopback
+iptables -A INPUT -i lo -j ACCEPT
+
+# Established/related
+iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
+
+# Tailscale overlay (100.64.0.0/10) — imrnes & peers
+iptables -A INPUT -s 100.64.0.0/10 -j ACCEPT
+
+# Public: SSH, HTTP(S)
+iptables -A INPUT -p tcp --dport 22 -j ACCEPT
+iptables -A INPUT -p tcp --dport 80 -j ACCEPT
+iptables -A INPUT -p tcp --dport 443 -j ACCEPT
+# Public: hermes dashboard (auth-protected)
+iptables -A INPUT -p tcp --dport 4013 -j ACCEPT
+
+# ICMP (ping, PMTU)
+iptables -A INPUT -p icmp --icmp-type echo-request -m limit --limit 5/sec --limit-burst 10 -j ACCEPT
+iptables -A INPUT -p icmp -m conntrack --ctstate NEW -j ACCEPT
+iptables -A INPUT -p icmp -j ACCEPT
+
+# Log dropped (rate-limited, 1 baris/5s)
+iptables -A INPUT -m limit --limit 5/min --limit-burst 10 -j LOG --log-prefix "FW-DROP " --log-level 4
+iptables -A INPUT -j DROP
+
+# UFW chains (dipanggil dari ts-input) — kosongkan
+iptables -F ufw-before-input 2>/dev/null || true
+iptables -F ufw-after-input 2>/dev/null || true
+iptables -F ufw-before-logging-input 2>/dev/null || true
+iptables -F ufw-after-logging-input 2>/dev/null || true
+iptables -F ufw-reject-input 2>/dev/null || true
+iptables -F ufw-track-input 2>/dev/null || true
+
+### IPv6 ###
+ip6tables -F
+ip6tables -X
+ip6tables -Z
+ip6tables -P INPUT DROP
+ip6tables -P FORWARD DROP
+ip6tables -P OUTPUT ACCEPT
+ip6tables -A INPUT -i lo -j ACCEPT
+ip6tables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
+# Tailscale IPv6 ULA (fd7a:115c::/48)
+ip6tables -A INPUT -s fd7a:115c::/48 -j ACCEPT
+ip6tables -A INPUT -p tcp --dport 22 -j ACCEPT
+ip6tables -A INPUT -p tcp --dport 80 -j ACCEPT
+ip6tables -A INPUT -p tcp --dport 443 -j ACCEPT
+ip6tables -A INPUT -p tcp --dport 4013 -j ACCEPT
+ip6tables -A INPUT -p icmpv6 -j ACCEPT
+ip6tables -A INPUT -m limit --limit 5/min --limit-burst 10 -j LOG --log-prefix "FW6-DROP " --log-level 4
+ip6tables -A INPUT -j DROP
+
+echo "Firewall applied:"
+iptables -L INPUT -n --line-numbers | head -20