#!/bin/sh

# Copyright (C) 2022-2024 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.

set -e

unpriv(){
  sudo -u nobody "$@"
}

# Compliance
systemctl mask debug-shell.service
systemctl mask kdump.service

# 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
sudo sed -i 's/umask 022/umask 077/g' /etc/bashrc

# Make home directory private
sudo chmod 700 /home/*

# Disable timesyncd
systemctl disable --now systemd-timesyncd
systemctl mask systemd-timesyncd

# Harden SSH
unpriv curl -s --proxy http://127.0.0.1:8082 https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/ssh/ssh_config.d/10-custom.conf | tee /etc/ssh/ssh_config.d/10-custom.conf > /dev/null
chmod 644 /etc/ssh/ssh_config.d/10-custom.conf

# Security kernel settings
unpriv curl -s --proxy http://127.0.0.1:8082 https://raw.githubusercontent.com/secureblue/secureblue/live/config/files/usr/etc/modprobe.d/blacklist.conf | sudo tee /etc/modprobe.d/workstation-blacklist.conf > /dev/null
sudo chmod 644 /etc/modprobe.d/workstation-blacklist.conf
unpriv curl -s --proxy https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/sysctl.d/99-workstation.conf | sudo tee /etc/sysctl.d/99-workstation.conf > /dev/null
sudo chmod 644 /etc/sysctl.d/30_security-misc_kexec-disable.conf
# Dracut doesn't seem to work - need to investigate
# dracut -f
sudo sysctl -p

# Setup ZRAM
unpriv curl --proxy http://127.0.0.1:8082 https://raw.githubusercontent.com/TommyTran732/Linux-Setup-Scripts/main/etc/systemd/zram-generator.conf | sudo tee /etc/systemd/zram-generator.conf > /dev/null

# Setup hardened_malloc
sudo dnf copr enable secureblue/hardened_malloc -y
sudo dnf install -y hardened_malloc
echo 'libhardened_malloc.so' | sudo tee /etc/ld.so.preload
sudo chmod 644 /etc/ld.so.preload