#!/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. output(){ echo -e '\e[36m'"$1"'\e[0m'; } unpriv(){ sudo -u nobody "$@" } # Compliance and updates sudo systemctl mask debug-shell.service ## Avoid phased updates 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 sudo apt full-upgrade -y sudo apt autoremove -y # Make home directory private sudo chmod 700 /home/* # Setup NTS sudo rm -rf /etc/chrony/chrony.conf unpriv curl https://raw.githubusercontent.com/GrapheneOS/infrastructure/main/chrony.conf | sudo tee /etc/chrony/chrony.conf sudo systemctl restart chronyd # Setup repositories sudo find /etc/apt/sources.list.d -type f -exec sudo sed -i 's/http:/https:/g' {} \; # Setup ufw sudo apt install ufw -y sudo ufw enable sudo ufw allow OpenSSH # 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 sshd # Kernel Hardening unpriv curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/etc/modprobe.d/30_security-misc.conf | sudo tee /etc/modprobe.d/30_security-misc.conf sudo chmod 644 /etc/modprobe.d/30_security-misc.conf sudo sed -i 's/#install msr/install msr/g' /etc/modprobe.d/30_security-misc.conf sudo sed -i 's/# install bluetooth/install bluetooth/g' /etc/modprobe.d/30_security-misc.conf sudo sed -i 's/# install btusb/install btusb/g' /etc/modprobe.d/30_security-misc.conf unpriv curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/usr/lib/sysctl.d/990-security-misc.conf | sudo tee /etc/sysctl.d/990-security-misc.conf sudo chmod 644 /etc/sysctl.d/990-security-misc.conf sudo sed -i 's/kernel.yama.ptrace_scope=2/kernel.yama.ptrace_scope=3/g' /etc/sysctl.d/990-security-misc.conf sudo sed -i 's/net.ipv4.icmp_echo_ignore_all=1/net.ipv4.icmp_echo_ignore_all=0/g' /etc/sysctl.d/990-security-misc.conf sudo sed -i 's/net.ipv6.icmp.echo_ignore_all=1/net.ipv6.icmp.echo_ignore_all=0/g' /etc/sysctl.d/990-security-misc.conf unpriv curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/usr/lib/sysctl.d/30_silent-kernel-printk.conf | sudo tee /etc/sysctl.d/30_silent-kernel-printk.conf sudo chmod 644 /etc/sysctl.d/30_silent-kernel-printk.conf unpriv curl https://raw.githubusercontent.com/Kicksecure/security-misc/master/usr/lib/sysctl.d/30_security-misc_kexec-disable.conf | sudo tee /etc/sysctl.d/30_security-misc_kexec-disable.conf sudo chmod 644 /etc/sysctl.d/30_security-misc_kexec-disable.conf sudo sysctl -p # Rebuild initramfs sudo update-initramfs -u # Disable coredump 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 # System Hardening sudo mkdir -p /etc/systemd/system/NetworkManager.service.d curl https://gitlab.com/divested/brace/-/raw/master/brace/usr/lib/systemd/system/NetworkManager.service.d/99-brace.conf | sudo tee /etc/systemd/system/NetworkManager.service.d/99-brace.conf # Update GRUB config # shellcheck disable=SC2016 echo 'GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX mitigations=auto,nosmt spectre_v2=on spec_store_bypass_disable=on tsx=off kvm.nx_huge_pages=force nosmt=force l1d_flush=on spec_rstack_overflow=safe-ret random.trust_bootloader=off random.trust_cpu=off intel_iommu=on amd_iommu=force_isolation efi=disable_early_pci_dma iommu=force iommu.passthrough=0 iommu.strict=1 slab_nomerge init_on_alloc=1 init_on_free=1 pti=on vsyscall=none ia32_emulation=0 page_alloc.shuffle=1 randomize_kstack_offset=on debugfs=off"' | sudo tee -a /etc/grub.d/40_custom sudo update-grub # Setup tuned sudo dnf install tuned -y sudo tuned-adm profile virtual-guest # Enable fstrim.timer sudo systemctl enable --now fstrim.timer ### Differentiating bare metal and virtual installs # Installing tuned first here because virt-what is 1 of its dependencies anyways sudo apt install tuned -y virt_type=$(virt-what) if [ "$virt_type" = "" ]; then output 'Virtualization: Bare Metal.' elif [ "$virt_type" = 'openvz lxc' ]; then output 'Virtualization: OpenVZ 7.' elif [ "$virt_type" = 'xen xen-hvm' ]; then output 'Virtualization: Xen-HVM.' elif [ "$virt_type" = 'xen xen-hvm aws' ]; then output 'Virtualization: Xen-HVM on AWS.' else output "Virtualization: $virt_type." fi # Setup tuned if [ "$virt_type" = "" ]; then sudo tuned-adm profile latency-performance else sudo tuned-adm profile virtual-guest fi # Setup fwupd if [ "$virt_type" = '' ]; then sudo apt install fwupd -y 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 instal unbound resolvconf -y 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 sudo reboot