#!/bin/sh # # Script for automatic setup of an IPsec VPN server on CentOS/RHEL 6 and 7. # Works on any dedicated server or Virtual Private Server (VPS) except OpenVZ. # # DO NOT RUN THIS SCRIPT ON YOUR PC OR MAC! # # The latest version of this script is available at: # https://github.com/hwdsl2/setup-ipsec-vpn # # Copyright (C) 2015-2016 Lin Song # Based on the work of Thomas Sarlandie (Copyright 2012) # # This work is licensed under the Creative Commons Attribution-ShareAlike 3.0 # Unported License: http://creativecommons.org/licenses/by-sa/3.0/ # # Attribution required: please include my name in any derivative and let me # know how you have improved it! # ===================================================== # Define your own values for these variables # - IPsec pre-shared key, VPN username and password # - All values MUST be placed inside 'single quotes' # - DO NOT use these characters within values: \ " ' YOUR_IPSEC_PSK='' YOUR_USERNAME='' YOUR_PASSWORD='' # Important notes: https://git.io/vpnnotes # Setup VPN clients: https://git.io/vpnclients # ===================================================== export PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin" SYS_DT="$(date +%Y-%m-%d-%H:%M:%S)"; export SYS_DT exiterr() { echo "Error: $1" >&2; exit 1; } exiterr2() { echo "Error: 'yum install' failed." >&2; exit 1; } conf_bk() { /bin/cp -f "$1" "$1.old-$SYS_DT" 2>/dev/null; } check_ip() { IP_REGEX="^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$" printf %s "$1" | tr -d '\n' | grep -Eq "$IP_REGEX" } if ! grep -qs -e "release 6" -e "release 7" /etc/redhat-release; then exiterr "This script only supports CentOS/RHEL 6 and 7." fi if [ -f /proc/user_beancounters ]; then echo "Error: This script does not support OpenVZ VPS." >&2 echo "Try OpenVPN: https://github.com/Nyr/openvpn-install" >&2 exit 1 fi if [ "$(id -u)" != 0 ]; then exiterr "Script must be run as root. Try 'sudo sh $0'" fi NET_IF0=${VPN_IFACE:-'eth0'} NET_IFS=${VPN_IFACE:-'eth+'} if_state=$(cat "/sys/class/net/$NET_IF0/operstate" 2>/dev/null) if [ -z "$if_state" ] || [ "$if_state" = "down" ] || [ "$NET_IF0" = "lo" ]; then echo "Error: Network interface '$NET_IF0' is not available." >&2 cat 1>&2 <<'EOF' DO NOT RUN THIS SCRIPT ON YOUR PC OR MAC! If running on a server, try this workaround: VPN_IFACE="$(route | grep '^default' | grep -o '[^ ]*$')" EOF cat 1>&2 </dev/null | grep -qs "$swan_ver"; then exiterr "Libreswan $swan_ver failed to build." fi # Create IPsec (Libreswan) config conf_bk "/etc/ipsec.conf" cat > /etc/ipsec.conf < /etc/ipsec.secrets < /etc/xl2tpd/xl2tpd.conf <<'EOF' [global] port = 1701 [lns default] ip range = 192.168.42.10-192.168.42.250 local ip = 192.168.42.1 require chap = yes refuse pap = yes require authentication = yes name = l2tpd pppoptfile = /etc/ppp/options.xl2tpd length bit = yes EOF # Set xl2tpd options conf_bk "/etc/ppp/options.xl2tpd" cat > /etc/ppp/options.xl2tpd <<'EOF' ipcp-accept-local ipcp-accept-remote ms-dns 8.8.8.8 ms-dns 8.8.4.4 noccp auth crtscts mtu 1280 mru 1280 lock proxyarp lcp-echo-failure 4 lcp-echo-interval 30 connect-delay 5000 EOF # Create VPN credentials conf_bk "/etc/ppp/chap-secrets" cat > /etc/ppp/chap-secrets < /etc/ipsec.d/passwd <> /etc/sysctl.conf </dev/null \ || ! iptables -t nat -C POSTROUTING -s 192.168.43.0/24 -o "$NET_IFS" -m policy --dir out --pol none -j SNAT --to-source "$PRIVATE_IP" 2>/dev/null; then ipt_flag=1 fi # Add IPTables rules for VPN if [ "$ipt_flag" = "1" ]; then service fail2ban stop >/dev/null 2>&1 iptables-save > "$IPT_FILE.old-$SYS_DT" iptables -I INPUT 1 -m conntrack --ctstate INVALID -j DROP iptables -I INPUT 2 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT iptables -I INPUT 3 -p udp -m multiport --dports 500,4500 -j ACCEPT iptables -I INPUT 4 -p udp --dport 1701 -m policy --dir in --pol ipsec -j ACCEPT iptables -I INPUT 5 -p udp --dport 1701 -j DROP iptables -I FORWARD 1 -m conntrack --ctstate INVALID -j DROP iptables -I FORWARD 2 -i "$NET_IFS" -o ppp+ -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT iptables -I FORWARD 3 -i ppp+ -o "$NET_IFS" -j ACCEPT iptables -I FORWARD 4 -i ppp+ -o ppp+ -s 192.168.42.0/24 -d 192.168.42.0/24 -j ACCEPT iptables -I FORWARD 5 -i "$NET_IFS" -d 192.168.43.0/24 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT iptables -I FORWARD 6 -s 192.168.43.0/24 -o "$NET_IFS" -j ACCEPT # Uncomment if you wish to disallow traffic between VPN clients themselves # iptables -I FORWARD 2 -i ppp+ -o ppp+ -s 192.168.42.0/24 -d 192.168.42.0/24 -j DROP # iptables -I FORWARD 3 -s 192.168.43.0/24 -d 192.168.43.0/24 -j DROP iptables -A FORWARD -j DROP iptables -t nat -I POSTROUTING -s 192.168.43.0/24 -o "$NET_IFS" -m policy --dir out --pol none -j SNAT --to-source "$PRIVATE_IP" iptables -t nat -I POSTROUTING -s 192.168.42.0/24 -o "$NET_IFS" -j SNAT --to-source "$PRIVATE_IP" echo "# Modified by hwdsl2 VPN script" > "$IPT_FILE" iptables-save >> "$IPT_FILE" fi # Create basic Fail2Ban rules if [ ! -f /etc/fail2ban/jail.local ] ; then cat > /etc/fail2ban/jail.local <<'EOF' [ssh-iptables] enabled = true filter = sshd action = iptables[name=SSH, port=ssh, protocol=tcp] logpath = /var/log/secure EOF fi # Start services at boot if grep -qs "release 6" /etc/redhat-release; then chkconfig iptables on chkconfig fail2ban on else systemctl --now mask firewalld yum -y install iptables-services || exiterr2 systemctl enable iptables fail2ban >/dev/null 2>&1 fi if ! grep -qs "hwdsl2 VPN script" /etc/rc.local; then conf_bk "/etc/rc.local" cat >> /etc/rc.local <<'EOF' # Added by hwdsl2 VPN script service ipsec start service xl2tpd start echo 1 > /proc/sys/net/ipv4/ip_forward EOF fi # Restore SELinux contexts restorecon /etc/ipsec.d/*db 2>/dev/null restorecon /usr/local/sbin -Rv 2>/dev/null restorecon /usr/local/libexec/ipsec -Rv 2>/dev/null # Reload sysctl.conf sysctl -e -q -p # Update file attributes chmod +x /etc/rc.local chmod 600 /etc/ipsec.secrets* /etc/ppp/chap-secrets* /etc/ipsec.d/passwd* # Apply new IPTables rules iptables-restore < "$IPT_FILE" # Restart services service fail2ban restart 2>/dev/null service ipsec restart 2>/dev/null service xl2tpd restart 2>/dev/null cat <