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openvpn-install.sh
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openvpn-install.sh
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#!/bin/bash
#
# https://github.com/hwdsl2/openvpn-install
#
# Based on the work of Nyr and contributors at:
# https://github.com/Nyr/openvpn-install
#
# Copyright (c) 2022-2024 Lin Song <[email protected]>
# Copyright (c) 2013-2023 Nyr
#
# Released under the MIT License, see the accompanying file LICENSE.txt
# or https://opensource.org/licenses/MIT
exiterr() { echo "Error: $1" >&2; exit 1; }
exiterr2() { exiterr "'apt-get install' failed."; }
exiterr3() { exiterr "'yum install' failed."; }
exiterr4() { exiterr "'zypper install' failed."; }
check_ip() {
IP_REGEX='^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$'
printf '%s' "$1" | tr -d '\n' | grep -Eq "$IP_REGEX"
}
check_pvt_ip() {
IPP_REGEX='^(10|127|172\.(1[6-9]|2[0-9]|3[0-1])|192\.168|169\.254)\.'
printf '%s' "$1" | tr -d '\n' | grep -Eq "$IPP_REGEX"
}
check_dns_name() {
FQDN_REGEX='^([a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}$'
printf '%s' "$1" | tr -d '\n' | grep -Eq "$FQDN_REGEX"
}
check_root() {
if [ "$(id -u)" != 0 ]; then
exiterr "This installer must be run as root. Try 'sudo bash $0'"
fi
}
check_shell() {
# Detect Debian users running the script with "sh" instead of bash
if readlink /proc/$$/exe | grep -q "dash"; then
exiterr 'This installer needs to be run with "bash", not "sh".'
fi
}
check_kernel() {
# Detect OpenVZ 6
if [[ $(uname -r | cut -d "." -f 1) -eq 2 ]]; then
exiterr "The system is running an old kernel, which is incompatible with this installer."
fi
}
check_os() {
if grep -qs "ubuntu" /etc/os-release; then
os="ubuntu"
os_version=$(grep 'VERSION_ID' /etc/os-release | cut -d '"' -f 2 | tr -d '.')
group_name="nogroup"
elif [[ -e /etc/debian_version ]]; then
os="debian"
os_version=$(grep -oE '[0-9]+' /etc/debian_version | head -1)
group_name="nogroup"
elif [[ -e /etc/almalinux-release || -e /etc/rocky-release || -e /etc/centos-release ]]; then
os="centos"
os_version=$(grep -shoE '[0-9]+' /etc/almalinux-release /etc/rocky-release /etc/centos-release | head -1)
group_name="nobody"
elif grep -qs "Amazon Linux release 2 " /etc/system-release; then
os="centos"
os_version="7"
group_name="nobody"
elif grep -qs "Amazon Linux release 2023" /etc/system-release; then
exiterr "Amazon Linux 2023 is not supported."
elif [[ -e /etc/fedora-release ]]; then
os="fedora"
os_version=$(grep -oE '[0-9]+' /etc/fedora-release | head -1)
group_name="nobody"
elif [[ -e /etc/SUSE-brand && "$(head -1 /etc/SUSE-brand)" == "openSUSE" ]]; then
os="openSUSE"
os_version=$(tail -1 /etc/SUSE-brand | grep -oE '[0-9\\.]+')
group_name="nogroup"
else
exiterr "This installer seems to be running on an unsupported distribution.
Supported distros are Ubuntu, Debian, AlmaLinux, Rocky Linux, CentOS, Fedora, openSUSE and Amazon Linux 2."
fi
}
check_os_ver() {
if [[ "$os" == "ubuntu" && "$os_version" -lt 2004 ]]; then
exiterr "Ubuntu 20.04 or higher is required to use this installer.
This version of Ubuntu is too old and unsupported."
fi
if [[ "$os" == "debian" && "$os_version" -lt 10 ]]; then
exiterr "Debian 10 or higher is required to use this installer.
This version of Debian is too old and unsupported."
fi
if [[ "$os" == "centos" && "$os_version" -lt 8 ]]; then
if ! grep -qs "Amazon Linux release 2 " /etc/system-release; then
exiterr "CentOS 8 or higher is required to use this installer.
This version of CentOS is too old and unsupported."
fi
fi
}
check_tun() {
if [[ ! -e /dev/net/tun ]] || ! ( exec 7<>/dev/net/tun ) 2>/dev/null; then
exiterr "The system does not have the TUN device available.
TUN needs to be enabled before running this installer."
fi
}
set_client_name() {
# Allow a limited set of characters to avoid conflicts
client=$(sed 's/[^0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-]/_/g' <<< "$unsanitized_client")
}
parse_args() {
while [ "$#" -gt 0 ]; do
case $1 in
--auto)
auto=1
shift
;;
--addclient)
add_client=1
unsanitized_client="$2"
shift
shift
;;
--exportclient)
export_client=1
unsanitized_client="$2"
shift
shift
;;
--listclients)
list_clients=1
shift
;;
--revokeclient)
revoke_client=1
unsanitized_client="$2"
shift
shift
;;
--uninstall)
remove_ovpn=1
shift
;;
--listenaddr)
listen_addr="$2"
shift
shift
;;
--serveraddr)
server_addr="$2"
shift
shift
;;
--proto)
server_proto="$2"
shift
shift
;;
--port)
server_port="$2"
shift
shift
;;
--clientname)
first_client_name="$2"
shift
shift
;;
--dns1)
dns1="$2"
shift
shift
;;
--dns2)
dns2="$2"
shift
shift
;;
-y|--yes)
assume_yes=1
shift
;;
-h|--help)
show_usage
;;
*)
show_usage "Unknown parameter: $1"
;;
esac
done
}
check_args() {
if [ "$auto" != 0 ] && [ -e "$OVPN_CONF" ]; then
show_usage "Invalid parameter '--auto'. OpenVPN is already set up on this server."
fi
if [ "$((add_client + export_client + list_clients + revoke_client))" -gt 1 ]; then
show_usage "Invalid parameters. Specify only one of '--addclient', '--exportclient', '--listclients' or '--revokeclient'."
fi
if [ "$remove_ovpn" = 1 ]; then
if [ "$((add_client + export_client + list_clients + revoke_client + auto))" -gt 0 ]; then
show_usage "Invalid parameters. '--uninstall' cannot be specified with other parameters."
fi
fi
if [ ! -e "$OVPN_CONF" ]; then
st_text="You must first set up OpenVPN before"
[ "$add_client" = 1 ] && exiterr "$st_text adding a client."
[ "$export_client" = 1 ] && exiterr "$st_text exporting a client."
[ "$list_clients" = 1 ] && exiterr "$st_text listing clients."
[ "$revoke_client" = 1 ] && exiterr "$st_text revoking a client."
[ "$remove_ovpn" = 1 ] && exiterr "Cannot remove OpenVPN because it has not been set up on this server."
fi
if [ "$((add_client + export_client + revoke_client))" = 1 ] && [ -n "$first_client_name" ]; then
show_usage "Invalid parameters. '--clientname' can only be specified when installing OpenVPN."
fi
if [ -n "$listen_addr" ] || [ -n "$server_addr" ] || [ -n "$server_proto" ] \
|| [ -n "$server_port" ] || [ -n "$first_client_name" ] || [ -n "$dns1" ]; then
if [ -e "$OVPN_CONF" ]; then
show_usage "Invalid parameters. OpenVPN is already set up on this server."
elif [ "$auto" = 0 ]; then
show_usage "Invalid parameters. You must specify '--auto' when using these parameters."
fi
fi
if [ "$add_client" = 1 ]; then
set_client_name
if [ -z "$client" ]; then
exiterr "Invalid client name. Use one word only, no special characters except '-' and '_'."
elif [ -e /etc/openvpn/server/easy-rsa/pki/issued/"$client".crt ]; then
exiterr "$client: invalid name. Client already exists."
fi
fi
if [ "$export_client" = 1 ] || [ "$revoke_client" = 1 ]; then
set_client_name
if [ -z "$client" ] || [ ! -e /etc/openvpn/server/easy-rsa/pki/issued/"$client".crt ]; then
exiterr "Invalid client name, or client does not exist."
fi
fi
if [ -n "$listen_addr" ] && ! check_ip "$listen_addr"; then
show_usage "Invalid listen address. Must be an IPv4 address."
fi
if [ -n "$listen_addr" ] && [ -z "$server_addr" ]; then
show_usage "You must also specify the server address if the listen address is specified."
fi
if [ -n "$server_addr" ] && { ! check_dns_name "$server_addr" && ! check_ip "$server_addr"; }; then
exiterr "Invalid server address. Must be a fully qualified domain name (FQDN) or an IPv4 address."
fi
if [ -n "$first_client_name" ]; then
unsanitized_client="$first_client_name"
set_client_name
if [ -z "$client" ]; then
exiterr "Invalid client name. Use one word only, no special characters except '-' and '_'."
fi
fi
if [ -n "$server_proto" ]; then
case "$server_proto" in
[tT][cC][pP])
server_proto=tcp
;;
[uU][dD][pP])
server_proto=udp
;;
*)
exiterr "Invalid protocol. Must be TCP or UDP."
;;
esac
fi
if [ -n "$server_port" ]; then
if [[ ! "$server_port" =~ ^[0-9]+$ || "$server_port" -gt 65535 ]]; then
exiterr "Invalid port. Must be an integer between 1 and 65535."
fi
fi
if { [ -n "$dns1" ] && ! check_ip "$dns1"; } \
|| { [ -n "$dns2" ] && ! check_ip "$dns2"; }; then
exiterr "Invalid DNS server(s)."
fi
if [ -z "$dns1" ] && [ -n "$dns2" ]; then
show_usage "Invalid DNS server. --dns2 cannot be specified without --dns1."
fi
if [ -n "$dns1" ]; then
dns=7
else
dns=2
fi
}
check_nftables() {
if [ "$os" = "centos" ]; then
if grep -qs "hwdsl2 VPN script" /etc/sysconfig/nftables.conf \
|| systemctl is-active --quiet nftables 2>/dev/null; then
exiterr "This system has nftables enabled, which is not supported by this installer."
fi
fi
}
install_wget() {
# Detect some Debian minimal setups where neither wget nor curl are installed
if ! hash wget 2>/dev/null && ! hash curl 2>/dev/null; then
if [ "$auto" = 0 ]; then
echo "Wget is required to use this installer."
read -n1 -r -p "Press any key to install Wget and continue..."
fi
export DEBIAN_FRONTEND=noninteractive
(
set -x
apt-get -yqq update || apt-get -yqq update
apt-get -yqq install wget >/dev/null
) || exiterr2
fi
}
install_iproute() {
if ! hash ip 2>/dev/null; then
if [ "$auto" = 0 ]; then
echo "iproute is required to use this installer."
read -n1 -r -p "Press any key to install iproute and continue..."
fi
if [ "$os" = "debian" ] || [ "$os" = "ubuntu" ]; then
export DEBIAN_FRONTEND=noninteractive
(
set -x
apt-get -yqq update || apt-get -yqq update
apt-get -yqq install iproute2 >/dev/null
) || exiterr2
elif [ "$os" = "openSUSE" ]; then
(
set -x
zypper install iproute2 >/dev/null
) || exiterr4
else
(
set -x
yum -y -q install iproute >/dev/null
) || exiterr3
fi
fi
}
show_header() {
cat <<'EOF'
OpenVPN Script
https://github.com/hwdsl2/openvpn-install
EOF
}
show_header2() {
cat <<'EOF'
Welcome to this OpenVPN server installer!
GitHub: https://github.com/hwdsl2/openvpn-install
EOF
}
show_header3() {
cat <<'EOF'
Copyright (c) 2022-2024 Lin Song
Copyright (c) 2013-2023 Nyr
EOF
}
show_usage() {
if [ -n "$1" ]; then
echo "Error: $1" >&2
fi
show_header
show_header3
cat 1>&2 <<EOF
Usage: bash $0 [options]
Options:
--addclient [client name] add a new client
--exportclient [client name] export configuration for an existing client
--listclients list the names of existing clients
--revokeclient [client name] revoke an existing client
--uninstall remove OpenVPN and delete all configuration
-y, --yes assume "yes" as answer to prompts when revoking a client or removing OpenVPN
-h, --help show this help message and exit
Install options (optional):
--auto auto install OpenVPN using default or custom options
--listenaddr [IPv4 address] IPv4 address that OpenVPN should listen on for requests
--serveraddr [DNS name or IP] server address, must be a fully qualified domain name (FQDN) or an IPv4 address
--proto [TCP or UDP] protocol for OpenVPN (TCP or UDP, default: UDP)
--port [number] port for OpenVPN (1-65535, default: 1194)
--clientname [client name] name for the first OpenVPN client (default: client)
--dns1 [DNS server IP] primary DNS server for clients (default: Google Public DNS)
--dns2 [DNS server IP] secondary DNS server for clients
To customize options, you may also run this script without arguments.
EOF
exit 1
}
show_welcome() {
if [ "$auto" = 0 ]; then
show_header2
echo 'I need to ask you a few questions before starting setup.'
echo 'You can use the default options and just press enter if you are OK with them.'
else
show_header
op_text=default
if [ -n "$listen_addr" ] || [ -n "$server_addr" ] || [ -n "$server_proto" ] \
|| [ -n "$server_port" ] || [ -n "$first_client_name" ] || [ -n "$dns1" ]; then
op_text=custom
fi
echo
echo "Starting OpenVPN setup using $op_text options."
fi
}
show_dns_name_note() {
cat <<EOF
Note: Make sure this DNS name '$1'
resolves to the IPv4 address of this server.
EOF
}
enter_server_address() {
echo
echo "Do you want OpenVPN clients to connect to this server using a DNS name,"
printf "e.g. vpn.example.com, instead of its IP address? [y/N] "
read -r response
case $response in
[yY][eE][sS]|[yY])
use_dns_name=1
echo
;;
*)
use_dns_name=0
;;
esac
if [ "$use_dns_name" = 1 ]; then
read -rp "Enter the DNS name of this VPN server: " server_addr_i
until check_dns_name "$server_addr_i"; do
echo "Invalid DNS name. You must enter a fully qualified domain name (FQDN)."
read -rp "Enter the DNS name of this VPN server: " server_addr_i
done
detect_ip
public_ip="$server_addr_i"
show_dns_name_note "$public_ip"
else
detect_ip
check_nat_ip
fi
}
find_public_ip() {
ip_url1="https://ipv4.icanhazip.com"
ip_url2="https://ip1.dynupdate.no-ip.com"
# Get public IP and sanitize with grep
get_public_ip=$(grep -m 1 -oE '^[0-9]{1,3}(\.[0-9]{1,3}){3}$' <<< "$(wget -T 10 -t 1 -4qO- "$ip_url1" || curl -m 10 -4Ls "$ip_url1")")
if ! check_ip "$get_public_ip"; then
get_public_ip=$(grep -m 1 -oE '^[0-9]{1,3}(\.[0-9]{1,3}){3}$' <<< "$(wget -T 10 -t 1 -4qO- "$ip_url2" || curl -m 10 -4Ls "$ip_url2")")
fi
}
detect_ip() {
# If system has a single IPv4, it is selected automatically.
if [[ $(ip -4 addr | grep inet | grep -vEc '127(\.[0-9]{1,3}){3}') -eq 1 ]]; then
ip=$(ip -4 addr | grep inet | grep -vE '127(\.[0-9]{1,3}){3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}(\.[0-9]{1,3}){3}')
else
# Use the IP address on the default route
ip=$(ip -4 route get 1 | sed 's/ uid .*//' | awk '{print $NF;exit}' 2>/dev/null)
if ! check_ip "$ip"; then
find_public_ip
ip_match=0
if [ -n "$get_public_ip" ]; then
ip_list=$(ip -4 addr | grep inet | grep -vE '127(\.[0-9]{1,3}){3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}(\.[0-9]{1,3}){3}')
while IFS= read -r line; do
if [ "$line" = "$get_public_ip" ]; then
ip_match=1
ip="$line"
fi
done <<< "$ip_list"
fi
if [ "$ip_match" = 0 ]; then
if [ "$auto" = 0 ]; then
echo
echo "Which IPv4 address should be used?"
num_of_ip=$(ip -4 addr | grep inet | grep -vEc '127(\.[0-9]{1,3}){3}')
ip -4 addr | grep inet | grep -vE '127(\.[0-9]{1,3}){3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}(\.[0-9]{1,3}){3}' | nl -s ') '
read -rp "IPv4 address [1]: " ip_num
until [[ -z "$ip_num" || "$ip_num" =~ ^[0-9]+$ && "$ip_num" -le "$num_of_ip" ]]; do
echo "$ip_num: invalid selection."
read -rp "IPv4 address [1]: " ip_num
done
[[ -z "$ip_num" ]] && ip_num=1
else
ip_num=1
fi
ip=$(ip -4 addr | grep inet | grep -vE '127(\.[0-9]{1,3}){3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}(\.[0-9]{1,3}){3}' | sed -n "$ip_num"p)
fi
fi
fi
if ! check_ip "$ip"; then
echo "Error: Could not detect this server's IP address." >&2
echo "Abort. No changes were made." >&2
exit 1
fi
}
check_nat_ip() {
# If $ip is a private IP address, the server must be behind NAT
if check_pvt_ip "$ip"; then
find_public_ip
if ! check_ip "$get_public_ip"; then
if [ "$auto" = 0 ]; then
echo
echo "This server is behind NAT. What is the public IPv4 address?"
read -rp "Public IPv4 address: " public_ip
until check_ip "$public_ip"; do
echo "Invalid input."
read -rp "Public IPv4 address: " public_ip
done
else
echo "Error: Could not detect this server's public IP." >&2
echo "Abort. No changes were made." >&2
exit 1
fi
else
public_ip="$get_public_ip"
fi
fi
}
show_config() {
if [ "$auto" != 0 ]; then
echo
if [ -n "$listen_addr" ]; then
echo "Listen address: $listen_addr"
fi
if [ -n "$server_addr" ]; then
echo "Server address: $server_addr"
else
printf '%s' "Server IP: "
[ -n "$public_ip" ] && printf '%s\n' "$public_ip" || printf '%s\n' "$ip"
fi
if [ "$server_proto" = "tcp" ]; then
proto_text=TCP
else
proto_text=UDP
fi
[ -n "$server_port" ] && port_text="$server_port" || port_text=1194
[ -n "$first_client_name" ] && client_text="$client" || client_text=client
if [ -n "$dns1" ] && [ -n "$dns2" ]; then
dns_text="$dns1, $dns2"
elif [ -n "$dns1" ]; then
dns_text="$dns1"
else
dns_text="Google Public DNS"
fi
echo "Port: $proto_text/$port_text"
echo "Client name: $client_text"
echo "Client DNS: $dns_text"
fi
}
detect_ipv6() {
ip6=""
if [[ $(ip -6 addr | grep -c 'inet6 [23]') -ne 0 ]]; then
ip6=$(ip -6 addr | grep 'inet6 [23]' | cut -d '/' -f 1 | grep -oE '([0-9a-fA-F]{0,4}:){1,7}[0-9a-fA-F]{0,4}' | sed -n 1p)
fi
}
select_protocol() {
if [ "$auto" = 0 ]; then
echo
echo "Which protocol should OpenVPN use?"
echo " 1) UDP (recommended)"
echo " 2) TCP"
read -rp "Protocol [1]: " protocol
until [[ -z "$protocol" || "$protocol" =~ ^[12]$ ]]; do
echo "$protocol: invalid selection."
read -rp "Protocol [1]: " protocol
done
case "$protocol" in
1|"")
protocol=udp
;;
2)
protocol=tcp
;;
esac
else
[ -n "$server_proto" ] && protocol="$server_proto" || protocol=udp
fi
}
select_port() {
if [ "$auto" = 0 ]; then
echo
echo "Which port should OpenVPN listen to?"
read -rp "Port [1194]: " port
until [[ -z "$port" || "$port" =~ ^[0-9]+$ && "$port" -le 65535 ]]; do
echo "$port: invalid port."
read -rp "Port [1194]: " port
done
[[ -z "$port" ]] && port=1194
else
[ -n "$server_port" ] && port="$server_port" || port=1194
fi
}
enter_custom_dns() {
read -rp "Enter primary DNS server: " dns1
until check_ip "$dns1"; do
echo "Invalid DNS server."
read -rp "Enter primary DNS server: " dns1
done
read -rp "Enter secondary DNS server (Enter to skip): " dns2
until [ -z "$dns2" ] || check_ip "$dns2"; do
echo "Invalid DNS server."
read -rp "Enter secondary DNS server (Enter to skip): " dns2
done
}
select_dns() {
if [ "$auto" = 0 ]; then
echo
echo "Select a DNS server for the clients:"
echo " 1) Current system resolvers"
echo " 2) Google Public DNS"
echo " 3) Cloudflare DNS"
echo " 4) OpenDNS"
echo " 5) Quad9"
echo " 6) AdGuard DNS"
echo " 7) Custom"
read -rp "DNS server [2]: " dns
until [[ -z "$dns" || "$dns" =~ ^[1-7]$ ]]; do
echo "$dns: invalid selection."
read -rp "DNS server [2]: " dns
done
else
dns=2
fi
if [ "$dns" = 7 ]; then
enter_custom_dns
fi
}
enter_first_client_name() {
if [ "$auto" = 0 ]; then
echo
echo "Enter a name for the first client:"
read -rp "Name [client]: " unsanitized_client
set_client_name
[[ -z "$client" ]] && client=client
else
if [ -n "$first_client_name" ]; then
unsanitized_client="$first_client_name"
set_client_name
else
client=client
fi
fi
}
show_setup_ready() {
if [ "$auto" = 0 ]; then
echo
echo "OpenVPN installation is ready to begin."
fi
}
check_firewall() {
# Install a firewall if firewalld or iptables are not already available
if ! systemctl is-active --quiet firewalld.service && ! hash iptables 2>/dev/null; then
if [[ "$os" == "centos" || "$os" == "fedora" ]]; then
firewall="firewalld"
elif [[ "$os" == "openSUSE" ]]; then
firewall="firewalld"
elif [[ "$os" == "debian" || "$os" == "ubuntu" ]]; then
firewall="iptables"
fi
if [[ "$firewall" == "firewalld" ]]; then
# We don't want to silently enable firewalld, so we give a subtle warning
# If the user continues, firewalld will be installed and enabled during setup
echo
echo "Note: firewalld, which is required to manage routing tables, will also be installed."
fi
fi
}
abort_and_exit() {
echo "Abort. No changes were made." >&2
exit 1
}
confirm_setup() {
if [ "$auto" = 0 ]; then
printf "Do you want to continue? [Y/n] "
read -r response
case $response in
[yY][eE][sS]|[yY]|'')
:
;;
*)
abort_and_exit
;;
esac
fi
}
show_start_setup() {
echo
echo "Installing OpenVPN, please wait..."
}
disable_limitnproc() {
# If running inside a container, disable LimitNPROC to prevent conflicts
if systemd-detect-virt -cq; then
mkdir /etc/systemd/system/[email protected]/ 2>/dev/null
echo "[Service]
LimitNPROC=infinity" > /etc/systemd/system/[email protected]/disable-limitnproc.conf
fi
}
install_pkgs() {
if [[ "$os" = "debian" || "$os" = "ubuntu" ]]; then
export DEBIAN_FRONTEND=noninteractive
(
set -x
apt-get -yqq update || apt-get -yqq update
apt-get -yqq --no-install-recommends install openvpn >/dev/null
) || exiterr2
(
set -x
apt-get -yqq install openssl ca-certificates $firewall >/dev/null
) || exiterr2
elif [[ "$os" = "centos" ]]; then
if grep -qs "Amazon Linux release 2 " /etc/system-release; then
(
set -x
amazon-linux-extras install epel -y >/dev/null
) || exit 1
else
(
set -x
yum -y -q install epel-release >/dev/null
) || exiterr3
fi
(
set -x
yum -y -q install openvpn openssl ca-certificates tar $firewall >/dev/null 2>&1
) || exiterr3
elif [[ "$os" = "fedora" ]]; then
(
set -x
dnf install -y openvpn openssl ca-certificates tar $firewall >/dev/null
) || exiterr "'dnf install' failed."
else
# Else, OS must be openSUSE
(
set -x
zypper install -y openvpn openssl ca-certificates tar $firewall >/dev/null
) || exiterr4
fi
# If firewalld was just installed, enable it
if [[ "$firewall" == "firewalld" ]]; then
(
set -x
systemctl enable --now firewalld.service >/dev/null 2>&1
)
fi
}
remove_pkgs() {
if [[ "$os" = "debian" || "$os" = "ubuntu" ]]; then
(
set -x
rm -rf /etc/openvpn/server
apt-get remove --purge -y openvpn >/dev/null
)
elif [[ "$os" = "openSUSE" ]]; then
(
set -x
zypper remove -y openvpn >/dev/null
rm -rf /etc/openvpn/server
)
rm -f /etc/openvpn/ipp.txt
else
# Else, OS must be CentOS or Fedora
(
set -x
yum -y -q remove openvpn >/dev/null
rm -rf /etc/openvpn/server
)
fi
}
create_firewall_rules() {
if systemctl is-active --quiet firewalld.service; then
# Using both permanent and not permanent rules to avoid a firewalld
# reload.
# We don't use --add-service=openvpn because that would only work with
# the default port and protocol.
firewall-cmd -q --add-port="$port"/"$protocol"
firewall-cmd -q --zone=trusted --add-source=10.8.0.0/24
firewall-cmd -q --permanent --add-port="$port"/"$protocol"
firewall-cmd -q --permanent --zone=trusted --add-source=10.8.0.0/24
# Set NAT for the VPN subnet
firewall-cmd -q --direct --add-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j MASQUERADE
firewall-cmd -q --permanent --direct --add-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j MASQUERADE
if [[ -n "$ip6" ]]; then
firewall-cmd -q --zone=trusted --add-source=fddd:1194:1194:1194::/64
firewall-cmd -q --permanent --zone=trusted --add-source=fddd:1194:1194:1194::/64
firewall-cmd -q --direct --add-rule ipv6 nat POSTROUTING 0 -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j MASQUERADE
firewall-cmd -q --permanent --direct --add-rule ipv6 nat POSTROUTING 0 -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j MASQUERADE
fi
else
# Create a service to set up persistent iptables rules
iptables_path=$(command -v iptables)
ip6tables_path=$(command -v ip6tables)
# nf_tables is not available as standard in OVZ kernels. So use iptables-legacy
# if we are in OVZ, with a nf_tables backend and iptables-legacy is available.
if [[ $(systemd-detect-virt) == "openvz" ]] && readlink -f "$(command -v iptables)" | grep -q "nft" && hash iptables-legacy 2>/dev/null; then
iptables_path=$(command -v iptables-legacy)
ip6tables_path=$(command -v ip6tables-legacy)
fi
echo "[Unit]
Before=network.target
[Service]
Type=oneshot
ExecStart=$iptables_path -t nat -A POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j MASQUERADE
ExecStart=$iptables_path -I INPUT -p $protocol --dport $port -j ACCEPT
ExecStart=$iptables_path -I FORWARD -s 10.8.0.0/24 -j ACCEPT
ExecStart=$iptables_path -I FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
ExecStop=$iptables_path -t nat -D POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j MASQUERADE
ExecStop=$iptables_path -D INPUT -p $protocol --dport $port -j ACCEPT
ExecStop=$iptables_path -D FORWARD -s 10.8.0.0/24 -j ACCEPT
ExecStop=$iptables_path -D FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT" > /etc/systemd/system/openvpn-iptables.service
if [[ -n "$ip6" ]]; then
echo "ExecStart=$ip6tables_path -t nat -A POSTROUTING -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j MASQUERADE
ExecStart=$ip6tables_path -I FORWARD -s fddd:1194:1194:1194::/64 -j ACCEPT
ExecStart=$ip6tables_path -I FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
ExecStop=$ip6tables_path -t nat -D POSTROUTING -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j MASQUERADE
ExecStop=$ip6tables_path -D FORWARD -s fddd:1194:1194:1194::/64 -j ACCEPT
ExecStop=$ip6tables_path -D FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT" >> /etc/systemd/system/openvpn-iptables.service
fi
echo "RemainAfterExit=yes
[Install]
WantedBy=multi-user.target" >> /etc/systemd/system/openvpn-iptables.service
(
set -x
systemctl enable --now openvpn-iptables.service >/dev/null 2>&1
)
fi
}
remove_firewall_rules() {
port=$(grep '^port ' "$OVPN_CONF" | cut -d " " -f 2)
protocol=$(grep '^proto ' "$OVPN_CONF" | cut -d " " -f 2)
if systemctl is-active --quiet firewalld.service; then
ip=$(firewall-cmd --direct --get-rules ipv4 nat POSTROUTING | grep '\-s 10.8.0.0/24 '"'"'!'"'"' -d 10.8.0.0/24' | grep -oE '[^ ]+$')
# Using both permanent and not permanent rules to avoid a firewalld reload.
firewall-cmd -q --remove-port="$port"/"$protocol"
firewall-cmd -q --zone=trusted --remove-source=10.8.0.0/24
firewall-cmd -q --permanent --remove-port="$port"/"$protocol"
firewall-cmd -q --permanent --zone=trusted --remove-source=10.8.0.0/24
firewall-cmd -q --direct --remove-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j MASQUERADE
firewall-cmd -q --permanent --direct --remove-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j MASQUERADE
if grep -qs "server-ipv6" "$OVPN_CONF"; then
ip6=$(firewall-cmd --direct --get-rules ipv6 nat POSTROUTING | grep '\-s fddd:1194:1194:1194::/64 '"'"'!'"'"' -d fddd:1194:1194:1194::/64' | grep -oE '[^ ]+$')
firewall-cmd -q --zone=trusted --remove-source=fddd:1194:1194:1194::/64
firewall-cmd -q --permanent --zone=trusted --remove-source=fddd:1194:1194:1194::/64
firewall-cmd -q --direct --remove-rule ipv6 nat POSTROUTING 0 -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j MASQUERADE
firewall-cmd -q --permanent --direct --remove-rule ipv6 nat POSTROUTING 0 -s fddd:1194:1194:1194::/64 ! -d fddd:1194:1194:1194::/64 -j MASQUERADE
fi
else
systemctl disable --now openvpn-iptables.service
rm -f /etc/systemd/system/openvpn-iptables.service
fi
if sestatus 2>/dev/null | grep "Current mode" | grep -q "enforcing" && [[ "$port" != 1194 ]]; then
semanage port -d -t openvpn_port_t -p "$protocol" "$port"
fi
}
install_easyrsa() {
# Get easy-rsa
easy_rsa_url='https://github.com/OpenVPN/easy-rsa/releases/download/v3.2.1/EasyRSA-3.2.1.tgz'
mkdir -p /etc/openvpn/server/easy-rsa/
{ wget -t 3 -T 30 -qO- "$easy_rsa_url" 2>/dev/null || curl -m 30 -sL "$easy_rsa_url" ; } | tar xz -C /etc/openvpn/server/easy-rsa/ --strip-components 1
if [ ! -f /etc/openvpn/server/easy-rsa/easyrsa ]; then
exiterr "Failed to download EasyRSA from $easy_rsa_url."
fi
chown -R root:root /etc/openvpn/server/easy-rsa/
}
create_pki_and_certs() {
cd /etc/openvpn/server/easy-rsa/ || exit 1
(
set -x
# Create the PKI, set up the CA and the server and client certificates
./easyrsa --batch init-pki >/dev/null
./easyrsa --batch build-ca nopass >/dev/null 2>&1
./easyrsa --batch --days=3650 build-server-full server nopass >/dev/null 2>&1
./easyrsa --batch --days=3650 build-client-full "$client" nopass >/dev/null 2>&1
./easyrsa --batch --days=3650 gen-crl >/dev/null 2>&1
)
# Move the stuff we need
cp pki/ca.crt pki/private/ca.key pki/issued/server.crt pki/private/server.key pki/crl.pem /etc/openvpn/server
# CRL is read with each client connection, while OpenVPN is dropped to nobody
chown nobody:"$group_name" /etc/openvpn/server/crl.pem
# Without +x in the directory, OpenVPN can't run a stat() on the CRL file
chmod o+x /etc/openvpn/server/
(
set -x
# Generate key for tls-crypt
openvpn --genkey --secret /etc/openvpn/server/tc.key >/dev/null
)
# Create the DH parameters file using the predefined ffdhe2048 group
echo '-----BEGIN DH PARAMETERS-----
MIIBCAKCAQEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz
+8yTnc4kmz75fS/jY2MMddj2gbICrsRhetPfHtXV/WVhJDP1H18GbtCFY2VVPe0a
87VXE15/V8k1mE8McODmi3fipona8+/och3xWKE2rec1MKzKT0g6eXq8CrGCsyT7
YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi
7MA0BM0oNC9hkXL+nOmFg/+OTxIy7vKBg8P+OxtMb61zO7X8vC7CIAXFjvGDfRaD
ssbzSibBsu/6iGtCOGEoXJf//////////wIBAg==
-----END DH PARAMETERS-----' > /etc/openvpn/server/dh.pem
}
create_dns_config() {
case "$dns" in
1)
# Locate the proper resolv.conf
# Needed for systems running systemd-resolved
if grep '^nameserver' "/etc/resolv.conf" | grep -qv '127.0.0.53' ; then
resolv_conf="/etc/resolv.conf"
else
resolv_conf="/run/systemd/resolve/resolv.conf"
fi
# Obtain the resolvers from resolv.conf and use them for OpenVPN
grep -v '^#\|^;' "$resolv_conf" | grep '^nameserver' | grep -v '127.0.0.53' | grep -oE '[0-9]{1,3}(\.[0-9]{1,3}){3}' | while read line; do
echo "push \"dhcp-option DNS $line\"" >> "$OVPN_CONF"
done
;;
2|"")
echo 'push "dhcp-option DNS 8.8.8.8"' >> "$OVPN_CONF"
echo 'push "dhcp-option DNS 8.8.4.4"' >> "$OVPN_CONF"
;;
3)
echo 'push "dhcp-option DNS 1.1.1.1"' >> "$OVPN_CONF"
echo 'push "dhcp-option DNS 1.0.0.1"' >> "$OVPN_CONF"
;;
4)
echo 'push "dhcp-option DNS 208.67.222.222"' >> "$OVPN_CONF"
echo 'push "dhcp-option DNS 208.67.220.220"' >> "$OVPN_CONF"
;;
5)
echo 'push "dhcp-option DNS 9.9.9.9"' >> "$OVPN_CONF"
echo 'push "dhcp-option DNS 149.112.112.112"' >> "$OVPN_CONF"
;;
6)
echo 'push "dhcp-option DNS 94.140.14.14"' >> "$OVPN_CONF"
echo 'push "dhcp-option DNS 94.140.15.15"' >> "$OVPN_CONF"
;;
7)
echo "push \"dhcp-option DNS $dns1\"" >> "$OVPN_CONF"
if [ -n "$dns2" ]; then
echo "push \"dhcp-option DNS $dns2\"" >> "$OVPN_CONF"
fi
;;
esac
}
create_server_config() {
# Generate server.conf
echo "local $ip
port $port
proto $protocol
dev tun
ca ca.crt
cert server.crt
key server.key
dh dh.pem
auth SHA256
tls-crypt tc.key
topology subnet
server 10.8.0.0 255.255.255.0" > "$OVPN_CONF"
# IPv6
if [[ -z "$ip6" ]]; then
echo 'push "block-ipv6"' >> "$OVPN_CONF"
echo 'push "ifconfig-ipv6 fddd:1194:1194:1194::2/64 fddd:1194:1194:1194::1"' >> "$OVPN_CONF"
else
echo 'server-ipv6 fddd:1194:1194:1194::/64' >> "$OVPN_CONF"
fi
echo 'push "redirect-gateway def1 ipv6 bypass-dhcp"' >> "$OVPN_CONF"
echo 'ifconfig-pool-persist ipp.txt' >> "$OVPN_CONF"
create_dns_config