Linux-Setup-Scripts/Ubuntu-22.04-Server.sh

#!/bin/bash

#Meant to be run on Ubuntu Pro Minimal 

#Compliance
sudo ua enable usg
sudo apt install -y usg
sudo usg fix cis_level2_server

#Install packages
sudo apt update -y
sudo apt full-upgrade -y
sudo apt install -y curl fwupd resolveconf tuned unbound

#Setup tuned
sudo tuned-adm profile virtual-guest

#Setup unbound
echo 'server:
  trust-anchor-signaling: yes
  root-key-sentinel: yes
  tls-cert-bundle: /etc/ssl/certs/ca-certificates.crt

  hide-identity: yes
  hide-trustanchor: yes
  hide-version: yes
  deny-any: yes
  harden-algo-downgrade: yes
  harden-large-queries: yes
  harden-referral-path: yes
  ignore-cd-flag: yes
  max-udp-size: 3072
  module-config: "validator iterator"
  qname-minimisation-strict: yes
  unwanted-reply-threshold: 10000000
  use-caps-for-id: yes

  outgoing-port-permit: 1024-65535

  prefetch: yes
  prefetch-key: yes


forward-zone:
  name: "."
  forward-tls-upstream: yes
  forward-addr: 1.1.1.2@853#security.cloudflare-dns.com
  forward-addr: 1.0.0.2@853#security.cloudflare-dns.com
  forward-addr: 2606:4700:4700::1112@853#security.cloudflare-dns.com
  forward-addr: 2606:4700:4700::1002@853#security.cloudflare-dns.com' | sudo tee /etc/unbound/unbound.conf.d/custom.conf

mkdir -p /etc/systemd/system/unbound.service.d
echo $'[Service]
CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_SETGID CAP_SETUID CAP_SYS_CHROOT CAP_SYS_RESOURCE CAP_NET_RAW
MemoryDenyWriteExecute=true
NoNewPrivileges=true
PrivateDevices=true
PrivateTmp=true
ProtectHome=true
ProtectClock=true
ProtectControlGroups=true
ProtectKernelLogs=true
ProtectKernelModules=true
# This breaks using socket options like \'so-rcvbuf\'. Explicitly disable for visibility.
ProtectKernelTunables=false
ProtectProc=invisible
RestrictAddressFamilies=AF_INET AF_INET6 AF_NETLINK AF_UNIX
RestrictRealtime=true
SystemCallArchitectures=native
SystemCallFilter=~@clock @cpu-emulation @debug @keyring @module mount @obsolete @resources
RestrictNamespaces=yes
LockPersonality=yes
RestrictSUIDSGID=yes
ReadWritePaths=@UNBOUND_RUN_DIR@ @UNBOUND_CHROOT_DIR@

# Below rules are needed when chroot is enabled (usually it\'s enabled by default).
# If chroot is disabled like chroot: "" then they may be safely removed.
TemporaryFileSystem=@UNBOUND_CHROOT_DIR@/dev:ro
TemporaryFileSystem=@UNBOUND_CHROOT_DIR@/run:ro
BindReadOnlyPaths=-/run/systemd/notify:@UNBOUND_CHROOT_DIR@/run/systemd/notify
BindReadOnlyPaths=-/dev/urandom:@UNBOUND_CHROOT_DIR@/dev/urandom
BindPaths=-/dev/log:@UNBOUND_CHROOT_DIR@/dev/log' | sudo tee /etc/systemd/system/unbound.service.d/override.conf

sudo systemctl daemon-reload
sudo systemctl restart unbound
sudo systemctl disable --now systemd-resolved

#Security kernel settings
sudo curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/etc/modprobe.d/30_security-misc.conf -o /etc/modprobe.d/30_security-misc.conf
sudo curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/etc/sysctl.d/30_security-misc.conf -o /etc/sysctl.d/30_security-misc.conf
sudo curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/etc/sysctl.d/30_silent-kernel-printk.conf -o /etc/sysctl.d/30_silent-kernel-printk.conf
sudo curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/etc/sysctl.d/30_security-misc_kexec-disable.conf -o /etc/sysctl.d/30_security-misc_kexec-disable.conf

echo "GSSAPIAuthentication no" | sudo tee /etc/ssh/ssh_config.d/10-custom.conf
echo "VerifyHostKeyDNS yes" | sudo tee -a /etc/ssh/ssh_config.d/10-custom.conf
sudo chmod 644 /etc/ssh/ssh_config.d/10-custom.conf

#Setup NTS
sudo systemctl disable systemd-timesyncd
sudo apt install -y chrony
rm -rf /etc/chrony/chrony.conf
sudo curl https://raw.githubusercontent.com/GrapheneOS/infrastructure/main/chrony.conf -o /etc/chrony/chrony.conf
sudo systemctl restart chronyd

#Setup UFW
#UFW Snap is strictly confined, unlike its .deb counterpart
sudo apt purge -y ufw
sudo snap install ufw
sudo ufw enable
sudo ufw allow 22

sudo systemctl stop apport.service
sudo systemctl disable apport.service
sudo systemctl mask apport.service
sudo systemctl stop whoopsie.service
sudo systemctl disable whoopsie.service
sudo systemctl mask whoopsie.service

mkdir -p /etc/systemd/system/fwupd-refresh.service.d
echo '[Service]
ExecStart=/usr/bin/fwupdmgr update' | tee /etc/systemd/system/fwupd-refresh.service.d/override.conf
sudo systemctl daemon-reload
sudo systemctl enable --now fwupd-refresh.timer

# Enable fstrim.timer
sudo systemctl enable --now fstrim.timer