#!/bin/bash # Copyright (C) 2021-2024 Thien Tran # # Licensed under the Apache License, Version 2.0 (the "License"); you may not # use this file except in compliance with the License. You may obtain a copy of # the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the # License for the specific language governing permissions and limitations under # the License. #Meant to be run on Ubuntu Pro Minimal output(){ echo -e '\e[36m'"$1"'\e[0m'; } unpriv(){ sudo -u nobody "$@" } virtualization=$(systemd-detect-virt) # Compliance and updates sudo systemctl mask debug-shell.service echo 'Authorized uses only. All activity may be monitored and reported.' | sudo tee /etc/issue echo 'Authorized uses only. All activity may be monitored and reported.' | sudo tee /etc/issue.net # Setting umask to 077 umask 077 sudo sed -i 's/^UMASK.*/UMASK 077/g' /etc/login.defs sudo sed -i 's/^HOME_MODE/#HOME_MODE/g' /etc/login.defs sudo sed -i 's/^USERGROUPS_ENAB.*/USERGROUPS_ENAB no/g' /etc/login.defs # Make home directory private sudo chmod 700 /home/* # Setup NTS sudo systemctl disable --now systemd-timesyncd sudo systemctl mask systemd-timesyncd sudo apt install -y chrony unpriv curl https://raw.githubusercontent.com/GrapheneOS/infrastructure/main/chrony.conf | sudo tee /etc/chrony/chrony.conf sudo systemctl restart chronyd # Harden SSH unpriv curl https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/ssh/sshd_config.d/10-custom.conf | sudo tee /etc/ssh/sshd_config.d/10-custom.conf sudo chmod 644 /etc/ssh/sshd_config.d/10-custom.conf unpriv curl https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/ssh/ssh_config.d/10-custom.conf | sudo tee /etc/ssh/ssh_config.d/10-custom.conf sudo chmod 644 /etc/ssh/ssh_config.d/10-custom.conf sudo mkdir -p /etc/systemd/system/ssh.service.d unpriv curl https://raw.githubusercontent.com/GrapheneOS/infrastructure/main/systemd/system/sshd.service.d/local.conf | sudo tee /etc/systemd/system/ssh.service.d/override.conf sudo systemctl daemon-reload sudo systemctl restart ssh # Security kernel settings unpriv curl https://raw.githubusercontent.com/secureblue/secureblue/live/config/files/usr/etc/modprobe.d/blacklist.conf | sudo tee /etc/modprobe.d/server-blacklist.conf sudo chmod 644 /etc/modprobe.d/server-blacklist.conf unpriv curl https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/sysctl.d/99-server.conf | sudo tee /etc/sysctl.d/99-server.conf sudo chmod 644 /etc/sysctl.d/99-server.conf sudo sysctl -p # Rebuild initramfs sudo update-initramfs -u # Disable coredump umask 022 unpriv curl https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/security/limits.d/30-disable-coredump.conf | sudo tee /etc/security/limits.d/30-disable-coredump.conf sudo mkdir -p /etc/systemd/coredump.conf.d unpriv curl https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/systemd/coredump.conf.d/disable.conf | sudo tee /etc/systemd/coredump.conf.d/disable.conf umask 077 # Update GRUB config if [ ! -d /boot/efi/EFI/ZBM ]; then # shellcheck disable=SC2016 sed -i 's/splash/splash mitigations=auto,nosmt spectre_v2=on spectre_bhi=on spec_store_bypass_disable=on tsx=off kvm.nx_huge_pages=force nosmt=force l1d_flush=on spec_rstack_overflow=safe-ret gather_data_sampling=force reg_file_data_sampling=on random.trust_bootloader=off random.trust_cpu=off intel_iommu=on amd_iommu=force_isolation efi=disable_early_pci_dma iommu=force iommu.passthrough=0 iommu.strict=1 slab_nomerge init_on_alloc=1 init_on_free=1 pti=on vsyscall=none ia32_emulation=0 page_alloc.shuffle=1 randomize_kstack_offset=on debugfs=off console=tty0 console=ttyS0,115200/g' /etc/default/grub sudo update-grub fi # Disable telemetry sudo systemctl disable --now apport.service sudo systemctl mask apport.service ## Avoid phased updates sudo apt install -y curl unpriv curl https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/apt/apt.conf.d/99sane-upgrades | sudo tee /etc/apt/apt.conf.d/99sane-upgrades sudo chmod 644 /etc/apt/apt.conf.d/99sane-upgrades sudo apt update -y sudo apt full-upgrade -y sudo apt autoremove -y ## Install basic sysadmin tools sudo apt install -y nano iputils-ping # Install appropriate virtualization drivers if [ "$virtualization" = 'kvm' ]; then sudo apt install -y qemu-guest-agent fi # Enable fstrim.timer sudo systemctl enable --now fstrim.timer ### Differentiating bare metal and virtual installs # Setup tuned sudo apt install -y tuned sudo systemctl enable --now tuned if [ "$virtualization" = 'none' ]; then sudo tuned-adm profile latency-performance else sudo tuned-adm profile virtual-guest fi # Setup fwupd if [ "$virtualization" = 'none' ]; then sudo apt install -y fwupd echo 'UriSchemes=file;https' | sudo tee -a /etc/fwupd/fwupd.conf sudo systemctl restart fwupd mkdir -p /etc/systemd/system/fwupd-refresh.service.d unpriv curl https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/systemd/system/fwupd-refresh.service.d/override.conf | sudo tee /etc/systemd/system/fwupd-refresh.service.d/override.conf sudo systemctl daemon-reload sudo systemctl enable --now fwupd-refresh.timer fi # Setup unbound sudo apt install -y 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 systemd-resolved # Setup networking # UFW Snap is strictly confined, unlike its .deb counterpart sudo apt purge -y ufw sudo snap install ufw sudo ufw enable sudo ufw allow SSH sudo reboot