#!/bin/sh SCRIPT_NAME=server-init-harden SCRIPT_VERSION=2.0 TIMESTAMP=$(date '+%Y-%m-%d_%H-%M-%S') LOGFILE_NAME="${SCRIPT_NAME}_${TIMESTAMP}.log" SHOW_CREDENTIALS=false START_TIME=$(date +%s) # username and root-reset flag USERNAME="" RESET_ROOT=false usage() { cat <>"$LOGFILE_NAME" } console_log() { # $1: Log level # $2: Log message case "$1" in Success | SUCCESS) printf "[\033[0;32m OK \033[0m] %s\n" "$2" ;; Error | ERROR) printf "[\033[0;31m FAIL \033[0m] %s\n" "$2" ;; Warning | WARNING) printf "[\033[0;33m WARN \033[0m] %s\n" "$2" ;; Info | INFO) printf "[\033[0;34m INFO \033[0m] %s\n" "$2" ;; CREDENTIALS) printf "[\033[0;30m CREDS \033[0m] %s\n" "$2" ;; *) printf "[ ] %s\n" "$2" ;; esac } log_credentials() { message="$1" file_log "$message" if [ "$SHOW_CREDENTIALS" = true ]; then console_log "CREDENTIALS" "$message" fi } print_logfile_details() { printf "\nLog file location: %s\n" "$LOGFILE_NAME" printf "To view the log file, use one of these commands:\n" printf " cat %s # View log file\n" "$LOGFILE_NAME" printf " tail -f %s # Follow log in real-time\n\n" "$LOGFILE_NAME" } formatted_execution_duration() { duration=$1 days=$((duration / 86400)) hours=$(((duration % 86400) / 3600)) minutes=$(((duration % 3600) / 60)) seconds=$((duration % 60)) if [ $days -gt 0 ]; then echo "${days}d ${hours}h ${minutes}m ${seconds}s" elif [ $hours -gt 0 ]; then echo "${hours}h ${minutes}m ${seconds}s" elif [ $minutes -gt 0 ]; then echo "${minutes}m ${seconds}s" else echo "${seconds}s" fi } manage_service() { service_name="$1" action="$2" # start, stop, restart, enable command_status=0 # Try service command if command -v service >/dev/null 2>&1; then file_log "Using service command for $service_name $action" case "$action" in enable) # Service command doesn't support enable # We will do nothing here, and let the systemctl handle this ;; *) output=$(service "$service_name" "$action" 2>&1) command_status=$? if [ -n "$output" ]; then file_log "service $action output: $output" fi return $command_status ;; esac fi # Try systemctl first (systemd) if command -v systemctl >/dev/null 2>&1; then file_log "Using systemctl for $service_name $action" output=$(systemctl "$action" "$service_name" 2>&1) command_status=$? if [ -n "$output" ]; then file_log "systemctl $action output: $output" fi return $command_status fi # Try init.d script if [ -x "/etc/init.d/$service_name" ]; then file_log "Using init.d script for $service_name $action" case "$action" in enable) # Try to enable using chkconfig if available if command -v chkconfig >/dev/null 2>&1; then output=$(chkconfig "$service_name" on 2>&1) command_status=$? if [ -n "$output" ]; then file_log "chkconfig output: $output" fi return $command_status elif command -v update-rc.d >/dev/null 2>&1; then output=$(update-rc.d "$service_name" defaults 2>&1) command_status=$? if [ -n "$output" ]; then file_log "update-rc.d output: $output" fi return $command_status fi ;; *) output=$("/etc/init.d/$service_name" "$action" 2>&1) command_status=$? if [ -n "$output" ]; then file_log "init.d $action output: $output" fi return $command_status ;; esac fi file_log "No suitable service manager found for $service_name" return 1 } ########################################################################################### ###################################### OPERATIONS ######################################### reset_root_password() { file_log "Attempting to reset root password" ROOT_PASSWORD=$(head -c 12 /dev/urandom | base64 | tr -dc "[:alnum:]" | head -c 15) # Change root password output=$(printf "%s\n%s\n" "${ROOT_PASSWORD}" "${ROOT_PASSWORD}" | passwd root 2>&1) # shellcheck disable=SC2181 if [ $? -ne 0 ]; then console_log "Error" "Failed to reset root password" file_log "Failed to reset root password" if [ -n "$output" ]; then file_log "passwd command output: $output" fi return 1 fi if [ -n "$output" ]; then file_log "passwd command output: $output" fi log_credentials "New root password: $ROOT_PASSWORD" return 0 } revert_create_user() { file_log "Attempting to remove user $USERNAME" # Check if the user exists before attempting to remove if id "$USERNAME" >/dev/null 2>&1; then # Remove user and its home directory output=$(userdel -r "$USERNAME" 2>&1) if [ -n "$output" ]; then file_log "userdel command output: $output" fi # shellcheck disable=SC2181 if [ $? -eq 0 ]; then file_log "User $USERNAME and home directory removed successfully" return 0 else file_log "Failed to remove user $USERNAME" return 1 fi else file_log "No user $USERNAME found to remove" return 0 fi } create_user() { # Check if username already exists if id "$USERNAME" >/dev/null 2>&1; then file_log "User $USERNAME already exists" return 1 fi # Generate a 15-character random password USER_PASSWORD=$(head -c 12 /dev/urandom | base64 | tr -dc "[:alnum:]" | head -c 15) file_log "Creating user $USERNAME" output=$(printf '%s\n%s\n' "${USER_PASSWORD}" "${USER_PASSWORD}" | adduser "$USERNAME" -q --gecos "First Last,RoomNumber,WorkPhone,HomePhone" 2>&1) # shellcheck disable=SC2181 if [ $? -ne 0 ]; then file_log "Failed to create user $USERNAME" return 1 fi if [ -n "$output" ]; then file_log "adduser command output: $output" fi output=$(usermod -aG sudo "$USERNAME" 2>&1) # shellcheck disable=SC2181 if [ $? -ne 0 ]; then console_log "Warning" "Failed to add user $USERNAME to sudo group" file_log "Failed to add user $USERNAME to sudo group" fi if [ -n "$output" ]; then file_log "usermod command output: $output" fi # Log user creation details file_log "User created: $USERNAME" console_log "Success" "User created: $USERNAME" log_credentials "$USERNAME's - Password: $USER_PASSWORD" return 0 } generate_ssh_key() { target_user="$1" console_log "INFO" "Generating SSH key for user: $target_user..." file_log "Generating SSH key for user: $target_user" home_dir=$(eval echo "~$target_user") if [ ! -d "$home_dir" ]; then console_log "ERROR" "Home directory not found for user: $target_user" file_log "Home directory not found for user: $target_user" return 1 fi # Create .ssh directory & set proper permissions ssh_dir="$home_dir/.ssh" if [ ! -d "$ssh_dir" ]; then mkdir -p "$ssh_dir" chown "$target_user:$target_user" "$ssh_dir" chmod 700 "$ssh_dir" file_log "Created .ssh directory: $ssh_dir" fi # Generate a strong passphrase key_passphrase=$(head -c 12 /dev/urandom | base64 | tr -dc "[:alnum:]" | head -c 15) key_name="id_${target_user}_ed25519" key_path="$ssh_dir/$key_name" # Generate the SSH key file_log "Generating SSH key for $target_user" if ! output=$(su -c "ssh-keygen -o -a 1000 -t ed25519 -f '$key_path' -N '$key_passphrase'" - "$target_user" 2>&1); then console_log "ERROR" "Failed to generate SSH key for user: $target_user" file_log "Failed to generate SSH key for user: $target_user" file_log "ssh-keygen output: $output" return 1 fi file_log "SSH key generated successfully for user: $target_user" # Set proper permissions for the key chmod 600 "$key_path" chmod 644 "$key_path.pub" # Append public key to authorized_keys authorized_keys="$ssh_dir/authorized_keys" if ! cat "$key_path.pub" >>"$authorized_keys"; then console_log "ERROR" "Failed to append public key to authorized_keys" file_log "Failed to append public key to authorized_keys" return 1 fi # Set proper permissions on authorized_keys chmod 400 "$authorized_keys" chown "$target_user:$target_user" "$authorized_keys" file_log "Added public key to: $authorized_keys" # Log the key details file_log "SSH key generated successfully for user: $target_user" console_log "Success" "SSH key generated successfully for user: $target_user" file_log "Key path: $key_path" console_log "Info" "Key path: $key_path" console_log "Info" "Authorized keys path: $authorized_keys" log_credentials "SSH key details for $target_user:" log_credentials "SSH Key passphrase: $key_passphrase" log_credentials "Private key content:" log_credentials "$(cat "$key_path")" log_credentials "Public key content:" log_credentials "$(cat "$key_path.pub")" return 0 } update_ssh_setting() { setting="$1" value="$2" # Comment out existing setting if found output=$(sed -i "s/^${setting}/#${setting}/" "$SSHD_CONFIG" 2>&1) if [ -n "$output" ]; then file_log "sed command output: $output" fi # Add new setting at the end of file echo "${setting} ${value}" >>"$SSHD_CONFIG" file_log "Updated SSH setting: ${setting} ${value}" } harden_ssh_config() { console_log "INFO" "Configuring SSH hardening settings..." file_log "Starting SSH configuration hardening" SSHD_CONFIG="/etc/ssh/sshd_config" if [ ! -f "$SSHD_CONFIG" ]; then console_log "ERROR" "SSH config file not found at $SSHD_CONFIG" file_log "SSH config file not found at $SSHD_CONFIG" return 1 fi # Create backup with timestamps BACKUP_FILE="${SSHD_CONFIG}.bak.${TIMESTAMP}" output=$(cp "$SSHD_CONFIG" "$BACKUP_FILE" 2>&1) if [ -n "$output" ]; then file_log "cp command output: $output" fi file_log "Created backup of sshd_config at: $BACKUP_FILE" # Update SSH settings update_ssh_setting "PermitRootLogin" "no" update_ssh_setting "PasswordAuthentication" "no" update_ssh_setting "PubkeyAuthentication" "yes" update_ssh_setting "AuthorizedKeysFile" ".ssh/authorized_keys" console_log "SUCCESS" "SSH configuration hardening completed" file_log "SSH configuration hardening completed" # Restart SSH service if manage_service sshd restart || manage_service ssh restart; then console_log "SUCCESS" "SSH service restarted successfully" file_log "SSH service restarted successfully" return 0 fi console_log "ERROR" "Failed to restart SSH service" file_log "Failed to restart SSH service" # Revert to backup and try restarting again console_log "INFO" "Reverting to backup configuration..." file_log "Reverting to backup configuration from: $BACKUP_FILE" if ! cp "$BACKUP_FILE" "$SSHD_CONFIG"; then console_log "ERROR" "Failed to restore SSH config backup" file_log "Failed to restore SSH config backup" exit 1 fi # Try restarting SSH with original config if manage_service sshd restart || manage_service ssh restart; then console_log "SUCCESS" "SSH service restarted successfully with original configuration" file_log "SSH service restarted successfully with original configuration" exit 1 fi console_log "ERROR" "Failed to restart SSH service even with original configuration" file_log "Failed to restart SSH service even with original configuration" exit 1 } install_package() { if [ $# -eq 0 ]; then file_log "No package specified for installation" return 1 fi PACKAGE_NAME="$1" # Detect the package manager and OS if [ -f /etc/debian_version ] || [ -f /etc/ubuntu_version ]; then # Debian/Ubuntu file_log "Installing $PACKAGE_NAME using apt..." # shellcheck disable=SC2086 output=$(DEBIAN_FRONTEND=noninteractive apt-get update && apt-get install -y --no-install-recommends $PACKAGE_NAME 2>&1) ret=$? elif [ -f /etc/fedora-release ]; then # Fedora file_log "Installing $PACKAGE_NAME using dnf..." # shellcheck disable=SC2086 output=$(dnf makecache && dnf install -y $PACKAGE_NAME 2>&1) ret=$? elif [ -f /etc/freebsd-update.conf ]; then # FreeBSD file_log "Installing $PACKAGE_NAME using pkg..." # shellcheck disable=SC2086 output=$(pkg update && pkg install -y $PACKAGE_NAME 2>&1) ret=$? else file_log "Unsupported operating system" return 1 fi # Log the output if any if [ -n "$output" ]; then file_log "Package installation output: $output" fi # Handle the return status if [ $ret -ne 0 ]; then file_log "Failed to install package: $PACKAGE_NAME" return 1 fi file_log "Successfully installed package: $PACKAGE_NAME" return 0 } configure_ufw() { console_log "INFO" "Starting UFW configuration..." file_log "Starting UFW configuration" # Check if UFW is installed if ! command -v ufw >/dev/null 2>&1; then file_log "UFW is not installed" return 1 fi output=$(ufw allow ssh 2>&1) if [ -n "$output" ]; then file_log "ufw allow ssh output: $output" fi output=$(ufw allow http 2>&1) if [ -n "$output" ]; then file_log "ufw allow http output: $output" fi output=$(ufw allow https 2>&1) if [ -n "$output" ]; then file_log "ufw allow https output: $output" fi # Enable UFW output=$(echo "y" | ufw enable 2>&1) if [ -n "$output" ]; then file_log "ufw enable output: $output" fi # Verify UFW is active output=$(ufw status 2>&1) if [ -n "$output" ]; then file_log "ufw status output: $output" fi if ! echo "$output" | grep -q "Status: active"; then console_log "ERROR" "UFW is not active after enabling" file_log "UFW is not active after enabling" return 1 fi console_log "Success" "UFW configuration completed successfully" file_log "UFW configuration completed successfully" return 0 } update_fail2ban_jail_local_file() { search_term="$1" new_value="$2" # We want to update the setting in the [DEFAULT] section # [DEFAULT] section ends right before "# JAILS" range_start="^\[DEFAULT\]$" range_end="^# JAILS$" # When the setting exists & it's NOT commented out -> comment it and add the new setting on next line if sed -n "/${range_start}/,/${range_end}/p" "$JAIL_LOCAL" | grep -q "^${search_term}[[:blank:]]*="; then sed -ri "/${range_start}/,/${range_end}/ s/^(${search_term}[[:blank:]]*=.*)/#\1/" "$JAIL_LOCAL" sed -ri "/${range_start}/,/${range_end}/ s/^#${search_term}[[:blank:]]*=.*/&\n${search_term} = ${new_value}/" "$JAIL_LOCAL" else # If the setting is commented out or it doesn't exist -> add it after the commented line or at the end of the section sed -ri "/${range_start}/,/${range_end}/ s/^#${search_term}[[:blank:]]*=.*/&\n${search_term} = ${new_value}/" "$JAIL_LOCAL" fi } configure_fail2ban() { console_log "INFO" "Starting Fail2ban configuration..." file_log "Starting Fail2ban configuration" if ! command -v fail2ban-client >/dev/null 2>&1; then file_log "Fail2ban is not installed" return 1 fi JAIL_LOCAL_FILE="/etc/fail2ban/jail.local" DEFAULT_JAIL_CONF_FILE="/etc/fail2ban/jail.conf" CUSTOM_JAILS_FILE="/etc/fail2ban/jail.d/custom-enabled.conf" # Backup jail.local if it exists if [ -f "$JAIL_LOCAL_FILE" ]; then JAIL_LOCAL_BACKUP_FILE="${JAIL_LOCAL_FILE}.bak.${TIMESTAMP}" cp "$JAIL_LOCAL_FILE" "$JAIL_LOCAL_BACKUP_FILE" file_log "Created backup of existing jail.local at $JAIL_LOCAL_BACKUP_FILE" else # Copy jail.conf to jail.local if jail.local doesn't exist if [ -f "$DEFAULT_JAIL_CONF_FILE" ]; then cp "$DEFAULT_JAIL_CONF_FILE" "$JAIL_LOCAL_FILE" file_log "Created jail.local from jail.conf" else console_log "ERROR" "Neither jail.conf nor jail.local exists" file_log "Neither jail.conf nor jail.local exists" return 1 fi fi # Fetch public IP using ipinfo.io/ip file_log "Attempting to get server's public IP" output=$(curl -s -4 ifconfig.me 2>&1 || curl -s -4 icanhazip.com 2>&1 || curl -s -4 ipinfo.io/ip 2>&1) if [ -z "$output" ]; then console_log "ERROR" "Could not determine server's public IP" file_log "Could not determine server's public IP" PUBLIC_IP="" else PUBLIC_IP="$output" file_log "Server public IP: $PUBLIC_IP" fi # Update default settings in jail.local update_fail2ban_jail_local_file "bantime" "5h" update_fail2ban_jail_local_file "backend" "systemd" update_fail2ban_jail_local_file "ignoreip" "127.0.0.1\/8 ::1 $PUBLIC_IP" # Enable jails and more settings for them in /etc/fail2ban/jail.d/custom-enabled.conf file_log "Enabling jails in $CUSTOM_JAILS_FILE" cat <$CUSTOM_JAILS_FILE [sshd] enabled = true filter = sshd bantime = 1d maxretry = 3 [nginx-http-auth] enabled = true logpath = /var/log/nginx/error.log maxretry = 3 # Repeat offenders across all other jails [recidive] enabled = true filter = recidive findtime = 1d bantime = 30d maxretry = 50 FAIL2BAN if ! manage_service fail2ban restart; then # If restarting service fails, try reverting all configurations & restart again console_log "ERROR" "Failed to restart fail2ban service" file_log "Failed to restart fail2ban service" # Revert jail.local to backup if it exists if [ -f "$JAIL_LOCAL_BACKUP_FILE" ]; then console_log "INFO" "Reverting jail.local to backup..." file_log "Reverting jail.local to backup from: $JAIL_LOCAL_BACKUP_FILE" if ! cp "$JAIL_LOCAL_BACKUP_FILE" "$JAIL_LOCAL_FILE"; then console_log "ERROR" "Failed to restore jail.local backup" file_log "Failed to restore jail.local backup" exit 1 fi else # If no backup exists (i.e, jail.local was created from jail.conf) -> remove jail.local console_log "INFO" "Removing newly created jail.local..." file_log "Removing newly created jail.local" rm -f "$JAIL_LOCAL_FILE" fi # Remove the custom enabled configuration if [ -f "$CUSTOM_JAILS_FILE" ]; then console_log "INFO" "Removing custom jail configuration..." file_log "Removing custom jail configuration: $CUSTOM_JAILS_FILE" rm -f "$CUSTOM_JAILS_FILE" fi # Try restarting fail2ban with original configuration if ! manage_service fail2ban restart; then console_log "ERROR" "Failed to restart fail2ban service even with original configuration" file_log "Failed to restart fail2ban service even with original configuration" exit 1 fi console_log "INFO" "Fail2ban restarted with original configuration" file_log "Fail2ban restarted with original configuration" exit 1 fi console_log "Success" "Fail2ban configuration completed successfully" file_log "Fail2ban configuration completed successfully" return 0 } main() { parse_args "$@" create_logfile print_logfile_details # Log script start console_log "INFO" "Starting $SCRIPT_NAME v$SCRIPT_VERSION" file_log "Starting $SCRIPT_NAME v$SCRIPT_VERSION" # Step 1: Reset root password if requested if [ "$RESET_ROOT" = true ]; then console_log "INFO" "Resetting root password..." reset_root_password # Continue regardless of any errors fi # Step 2: Create new user if [ -n "$USERNAME" ]; then console_log "INFO" "Creating user..." create_user # Continue regardless of any errors fi # Step 3: Generate SSH key for user if [ -n "$USERNAME" ]; then if ! generate_ssh_key "$USERNAME"; then console_log "ERROR" "Failed to generate SSH key for new user: $USERNAME" print_logfile_details return 1 # Abort on error fi else CURRENT_USER=$(whoami) if ! generate_ssh_key "$CURRENT_USER"; then console_log "ERROR" "Failed to generate SSH key for current user: $CURRENT_USER" print_logfile_details return 1 # Abort on error fi fi # Step 4: Configure SSH if ! harden_ssh_config; then print_logfile_details return 1 # Abort on error fi # Step 5: Install required packages console_log "INFO" "Installing required packages" file_log "Installing required packages" if ! install_package "curl ufw fail2ban"; then console_log "ERROR" "Failed to install required packages" print_logfile_details return 1 # Abort on error fi console_log "Success" "Successfully installed all required packages" file_log "Successfully installed all required packages" # Step 6: Configure UFW console_log "INFO" "Configuring UFW" file_log "Configuring UFW" if ! configure_ufw; then console_log "ERROR" "Failed to configure UFW" print_logfile_details return 1 # Abort on error fi console_log "Success" "Successfully configured UFW" file_log "Successfully configured UFW" # Step 7: Configure Fail2ban console_log "INFO" "Configuring Fail2ban" file_log "Configuring Fail2ban" if ! configure_fail2ban; then console_log "ERROR" "Failed to configure Fail2ban" print_logfile_details return 1 # Abort on error fi console_log "Success" "Successfully configured Fail2ban" file_log "Successfully configured Fail2ban" console_log "SUCCESS" "Script completed successfully" file_log "Script completed successfully" # Calculate and show execution time END_TIME=$(date +%s) DURATION=$((END_TIME - START_TIME)) FORMATTED_DURATION=$(formatted_execution_duration $DURATION) console_log "INFO" "Total execution time: $FORMATTED_DURATION" file_log "Total execution time: $FORMATTED_DURATION" print_logfile_details return 0 } main "$@"