mod

scripts/init.sh

@@ -4,6 +4,6 @@ apt update -y
 apt install golang-go
 
 # vpn
-curl -O https://raw.githubusercontent.com/angristan/openvpn-install/master/openvpn-install.sh
+#curl -O https://raw.githubusercontent.com/angristan/openvpn-install/master/openvpn-install.sh
 chmod +x openvpn-install.sh
 export AUTO_INSTALL=y && ./openvpn-install.sh

scripts/openvpn-install.sh

@@ -0,0 +1,1344 @@
+#!/bin/bash
+# shellcheck disable=SC1091,SC2164,SC2034,SC1072,SC1073,SC1009
+
+# Secure OpenVPN server installer for Debian, Ubuntu, CentOS, Amazon Linux 2, Fedora, Oracle Linux 8, Arch Linux, Rocky Linux and AlmaLinux.
+# https://github.com/angristan/openvpn-install
+
+function isRoot() {
+	if [ "$EUID" -ne 0 ]; then
+		return 1
+	fi
+}
+
+function tunAvailable() {
+	if [ ! -e /dev/net/tun ]; then
+		return 1
+	fi
+}
+
+function checkOS() {
+	if [[ -e /etc/debian_version ]]; then
+		OS="debian"
+		source /etc/os-release
+
+		if [[ $ID == "debian" || $ID == "raspbian" ]]; then
+			if [[ $VERSION_ID -lt 9 ]]; then
+				echo "⚠️ Your version of Debian is not supported."
+				echo ""
+				echo "However, if you're using Debian >= 9 or unstable/testing then you can continue, at your own risk."
+				echo ""
+				until [[ $CONTINUE =~ (y|n) ]]; do
+					read -rp "Continue? [y/n]: " -e CONTINUE
+				done
+				if [[ $CONTINUE == "n" ]]; then
+					exit 1
+				fi
+			fi
+		elif [[ $ID == "ubuntu" ]]; then
+			OS="ubuntu"
+			MAJOR_UBUNTU_VERSION=$(echo "$VERSION_ID" | cut -d '.' -f1)
+			if [[ $MAJOR_UBUNTU_VERSION -lt 16 ]]; then
+				echo "⚠️ Your version of Ubuntu is not supported."
+				echo ""
+				echo "However, if you're using Ubuntu >= 16.04 or beta, then you can continue, at your own risk."
+				echo ""
+				until [[ $CONTINUE =~ (y|n) ]]; do
+					read -rp "Continue? [y/n]: " -e CONTINUE
+				done
+				if [[ $CONTINUE == "n" ]]; then
+					exit 1
+				fi
+			fi
+		fi
+	elif [[ -e /etc/system-release ]]; then
+		source /etc/os-release
+		if [[ $ID == "fedora" || $ID_LIKE == "fedora" ]]; then
+			OS="fedora"
+		fi
+		if [[ $ID == "centos" || $ID == "rocky" || $ID == "almalinux" ]]; then
+			OS="centos"
+			if [[ $VERSION_ID -lt 7 ]]; then
+				echo "⚠️ Your version of CentOS is not supported."
+				echo ""
+				echo "The script only support CentOS 7 and CentOS 8."
+				echo ""
+				exit 1
+			fi
+		fi
+		if [[ $ID == "ol" ]]; then
+			OS="oracle"
+			if [[ ! $VERSION_ID =~ (8) ]]; then
+				echo "Your version of Oracle Linux is not supported."
+				echo ""
+				echo "The script only support Oracle Linux 8."
+				exit 1
+			fi
+		fi
+		if [[ $ID == "amzn" ]]; then
+			OS="amzn"
+			if [[ $VERSION_ID != "2" ]]; then
+				echo "⚠️ Your version of Amazon Linux is not supported."
+				echo ""
+				echo "The script only support Amazon Linux 2."
+				echo ""
+				exit 1
+			fi
+		fi
+	elif [[ -e /etc/arch-release ]]; then
+		OS=arch
+	else
+		echo "Looks like you aren't running this installer on a Debian, Ubuntu, Fedora, CentOS, Amazon Linux 2, Oracle Linux 8 or Arch Linux system"
+		exit 1
+	fi
+}
+
+function initialCheck() {
+	if ! isRoot; then
+		echo "Sorry, you need to run this as root"
+		exit 1
+	fi
+	if ! tunAvailable; then
+		echo "TUN is not available"
+		exit 1
+	fi
+	checkOS
+}
+
+function installUnbound() {
+	# If Unbound isn't installed, install it
+	if [[ ! -e /etc/unbound/unbound.conf ]]; then
+
+		if [[ $OS =~ (debian|ubuntu) ]]; then
+			apt-get install -y unbound
+
+			# Configuration
+			echo 'interface: 10.8.0.1
+access-control: 10.8.0.1/24 allow
+hide-identity: yes
+hide-version: yes
+use-caps-for-id: yes
+prefetch: yes' >>/etc/unbound/unbound.conf
+
+		elif [[ $OS =~ (centos|amzn|oracle) ]]; then
+			yum install -y unbound
+
+			# Configuration
+			sed -i 's|# interface: 0.0.0.0$|interface: 10.8.0.1|' /etc/unbound/unbound.conf
+			sed -i 's|# access-control: 127.0.0.0/8 allow|access-control: 10.8.0.1/24 allow|' /etc/unbound/unbound.conf
+			sed -i 's|# hide-identity: no|hide-identity: yes|' /etc/unbound/unbound.conf
+			sed -i 's|# hide-version: no|hide-version: yes|' /etc/unbound/unbound.conf
+			sed -i 's|use-caps-for-id: no|use-caps-for-id: yes|' /etc/unbound/unbound.conf
+
+		elif [[ $OS == "fedora" ]]; then
+			dnf install -y unbound
+
+			# Configuration
+			sed -i 's|# interface: 0.0.0.0$|interface: 10.8.0.1|' /etc/unbound/unbound.conf
+			sed -i 's|# access-control: 127.0.0.0/8 allow|access-control: 10.8.0.1/24 allow|' /etc/unbound/unbound.conf
+			sed -i 's|# hide-identity: no|hide-identity: yes|' /etc/unbound/unbound.conf
+			sed -i 's|# hide-version: no|hide-version: yes|' /etc/unbound/unbound.conf
+			sed -i 's|# use-caps-for-id: no|use-caps-for-id: yes|' /etc/unbound/unbound.conf
+
+		elif [[ $OS == "arch" ]]; then
+			pacman -Syu --noconfirm unbound
+
+			# Get root servers list
+			curl -o /etc/unbound/root.hints https://www.internic.net/domain/named.cache
+
+			if [[ ! -f /etc/unbound/unbound.conf.old ]]; then
+				mv /etc/unbound/unbound.conf /etc/unbound/unbound.conf.old
+			fi
+
+			echo 'server:
+	use-syslog: yes
+	do-daemonize: no
+	username: "unbound"
+	directory: "/etc/unbound"
+	trust-anchor-file: trusted-key.key
+	root-hints: root.hints
+	interface: 10.8.0.1
+	access-control: 10.8.0.1/24 allow
+	port: 53
+	num-threads: 2
+	use-caps-for-id: yes
+	harden-glue: yes
+	hide-identity: yes
+	hide-version: yes
+	qname-minimisation: yes
+	prefetch: yes' >/etc/unbound/unbound.conf
+		fi
+
+		# IPv6 DNS for all OS
+		if [[ $IPV6_SUPPORT == 'y' ]]; then
+			echo 'interface: fd42:42:42:42::1
+access-control: fd42:42:42:42::/112 allow' >>/etc/unbound/unbound.conf
+		fi
+
+		if [[ ! $OS =~ (fedora|centos|amzn|oracle) ]]; then
+			# DNS Rebinding fix
+			echo "private-address: 10.0.0.0/8
+private-address: fd42:42:42:42::/112
+private-address: 172.16.0.0/12
+private-address: 192.168.0.0/16
+private-address: 169.254.0.0/16
+private-address: fd00::/8
+private-address: fe80::/10
+private-address: 127.0.0.0/8
+private-address: ::ffff:0:0/96" >>/etc/unbound/unbound.conf
+		fi
+	else # Unbound is already installed
+		echo 'include: /etc/unbound/openvpn.conf' >>/etc/unbound/unbound.conf
+
+		# Add Unbound 'server' for the OpenVPN subnet
+		echo 'server:
+interface: 10.8.0.1
+access-control: 10.8.0.1/24 allow
+hide-identity: yes
+hide-version: yes
+use-caps-for-id: yes
+prefetch: yes
+private-address: 10.0.0.0/8
+private-address: fd42:42:42:42::/112
+private-address: 172.16.0.0/12
+private-address: 192.168.0.0/16
+private-address: 169.254.0.0/16
+private-address: fd00::/8
+private-address: fe80::/10
+private-address: 127.0.0.0/8
+private-address: ::ffff:0:0/96' >/etc/unbound/openvpn.conf
+		if [[ $IPV6_SUPPORT == 'y' ]]; then
+			echo 'interface: fd42:42:42:42::1
+access-control: fd42:42:42:42::/112 allow' >>/etc/unbound/openvpn.conf
+		fi
+	fi
+
+	systemctl enable unbound
+	systemctl restart unbound
+}
+
+function installQuestions() {
+	echo "Welcome to the OpenVPN installer!"
+	echo "The git repository is available at: https://github.com/angristan/openvpn-install"
+	echo ""
+
+	echo "I need to ask you a few questions before starting the setup."
+	echo "You can leave the default options and just press enter if you are ok with them."
+	echo ""
+	echo "I need to know the IPv4 address of the network interface you want OpenVPN listening to."
+	echo "Unless your server is behind NAT, it should be your public IPv4 address."
+
+	# Detect public IPv4 address and pre-fill for the user
+	IP=$(ip -4 addr | sed -ne 's|^.* inet \([^/]*\)/.* scope global.*$|\1|p' | head -1)
+
+	if [[ -z $IP ]]; then
+		# Detect public IPv6 address
+		IP=$(ip -6 addr | sed -ne 's|^.* inet6 \([^/]*\)/.* scope global.*$|\1|p' | head -1)
+	fi
+	APPROVE_IP=${APPROVE_IP:-n}
+	if [[ $APPROVE_IP =~ n ]]; then
+		read -rp "IP address: " -e -i "$IP" IP
+	fi
+	# If $IP is a private IP address, the server must be behind NAT
+	if echo "$IP" | grep -qE '^(10\.|172\.1[6789]\.|172\.2[0-9]\.|172\.3[01]\.|192\.168)'; then
+		echo ""
+		echo "It seems this server is behind NAT. What is its public IPv4 address or hostname?"
+		echo "We need it for the clients to connect to the server."
+
+		PUBLICIP=$(curl -s https://api.ipify.org)
+		until [[ $ENDPOINT != "" ]]; do
+			read -rp "Public IPv4 address or hostname: " -e -i "$PUBLICIP" ENDPOINT
+		done
+	fi
+
+	echo ""
+	echo "Checking for IPv6 connectivity..."
+	echo ""
+	# "ping6" and "ping -6" availability varies depending on the distribution
+	if type ping6 >/dev/null 2>&1; then
+		PING6="ping6 -c3 ipv6.google.com > /dev/null 2>&1"
+	else
+		PING6="ping -6 -c3 ipv6.google.com > /dev/null 2>&1"
+	fi
+	if eval "$PING6"; then
+		echo "Your host appears to have IPv6 connectivity."
+		SUGGESTION="y"
+	else
+		echo "Your host does not appear to have IPv6 connectivity."
+		SUGGESTION="n"
+	fi
+	echo ""
+	# Ask the user if they want to enable IPv6 regardless its availability.
+	until [[ $IPV6_SUPPORT =~ (y|n) ]]; do
+		read -rp "Do you want to enable IPv6 support (NAT)? [y/n]: " -e -i $SUGGESTION IPV6_SUPPORT
+	done
+	echo ""
+	echo "What port do you want OpenVPN to listen to?"
+	echo "   1) Default: 1194"
+	echo "   2) Custom"
+	echo "   3) Random [49152-65535]"
+	until [[ $PORT_CHOICE =~ ^[1-3]$ ]]; do
+		read -rp "Port choice [1-3]: " -e -i 1 PORT_CHOICE
+	done
+	case $PORT_CHOICE in
+	1)
+		PORT="1194"
+		;;
+	2)
+		until [[ $PORT =~ ^[0-9]+$ ]] && [ "$PORT" -ge 1 ] && [ "$PORT" -le 65535 ]; do
+			read -rp "Custom port [1-65535]: " -e -i 1194 PORT
+		done
+		;;
+	3)
+		# Generate random number within private ports range
+		PORT=$(shuf -i49152-65535 -n1)
+		echo "Random Port: $PORT"
+		;;
+	esac
+	echo ""
+	echo "What protocol do you want OpenVPN to use?"
+	echo "UDP is faster. Unless it is not available, you shouldn't use TCP."
+	echo "   1) UDP"
+	echo "   2) TCP"
+	until [[ $PROTOCOL_CHOICE =~ ^[1-2]$ ]]; do
+		read -rp "Protocol [1-2]: " -e -i 1 PROTOCOL_CHOICE
+	done
+	case $PROTOCOL_CHOICE in
+	1)
+		PROTOCOL="udp"
+		;;
+	2)
+		PROTOCOL="tcp"
+		;;
+	esac
+	echo ""
+	echo "What DNS resolvers do you want to use with the VPN?"
+	echo "   1) Current system resolvers (from /etc/resolv.conf)"
+	echo "   2) Self-hosted DNS Resolver (Unbound)"
+	echo "   3) Cloudflare (Anycast: worldwide)"
+	echo "   4) Quad9 (Anycast: worldwide)"
+	echo "   5) Quad9 uncensored (Anycast: worldwide)"
+	echo "   6) FDN (France)"
+	echo "   7) DNS.WATCH (Germany)"
+	echo "   8) OpenDNS (Anycast: worldwide)"
+	echo "   9) Google (Anycast: worldwide)"
+	echo "   10) Yandex Basic (Russia)"
+	echo "   11) AdGuard DNS (Anycast: worldwide)"
+	echo "   12) NextDNS (Anycast: worldwide)"
+	echo "   13) Custom"
+	until [[ $DNS =~ ^[0-9]+$ ]] && [ "$DNS" -ge 1 ] && [ "$DNS" -le 13 ]; do
+		read -rp "DNS [1-12]: " -e -i 11 DNS
+		if [[ $DNS == 2 ]] && [[ -e /etc/unbound/unbound.conf ]]; then
+			echo ""
+			echo "Unbound is already installed."
+			echo "You can allow the script to configure it in order to use it from your OpenVPN clients"
+			echo "We will simply add a second server to /etc/unbound/unbound.conf for the OpenVPN subnet."
+			echo "No changes are made to the current configuration."
+			echo ""
+
+			until [[ $CONTINUE =~ (y|n) ]]; do
+				read -rp "Apply configuration changes to Unbound? [y/n]: " -e CONTINUE
+			done
+			if [[ $CONTINUE == "n" ]]; then
+				# Break the loop and cleanup
+				unset DNS
+				unset CONTINUE
+			fi
+		elif [[ $DNS == "13" ]]; then
+			until [[ $DNS1 =~ ^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$ ]]; do
+				read -rp "Primary DNS: " -e DNS1
+			done
+			until [[ $DNS2 =~ ^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$ ]]; do
+				read -rp "Secondary DNS (optional): " -e DNS2
+				if [[ $DNS2 == "" ]]; then
+					break
+				fi
+			done
+		fi
+	done
+	echo ""
+	echo "Do you want to use compression? It is not recommended since the VORACLE attack makes use of it."
+	until [[ $COMPRESSION_ENABLED =~ (y|n) ]]; do
+		read -rp"Enable compression? [y/n]: " -e -i n COMPRESSION_ENABLED
+	done
+	if [[ $COMPRESSION_ENABLED == "y" ]]; then
+		echo "Choose which compression algorithm you want to use: (they are ordered by efficiency)"
+		echo "   1) LZ4-v2"
+		echo "   2) LZ4"
+		echo "   3) LZ0"
+		until [[ $COMPRESSION_CHOICE =~ ^[1-3]$ ]]; do
+			read -rp"Compression algorithm [1-3]: " -e -i 1 COMPRESSION_CHOICE
+		done
+		case $COMPRESSION_CHOICE in
+		1)
+			COMPRESSION_ALG="lz4-v2"
+			;;
+		2)
+			COMPRESSION_ALG="lz4"
+			;;
+		3)
+			COMPRESSION_ALG="lzo"
+			;;
+		esac
+	fi
+	echo ""
+	echo "Do you want to customize encryption settings?"
+	echo "Unless you know what you're doing, you should stick with the default parameters provided by the script."
+	echo "Note that whatever you choose, all the choices presented in the script are safe. (Unlike OpenVPN's defaults)"
+	echo "See https://github.com/angristan/openvpn-install#security-and-encryption to learn more."
+	echo ""
+	until [[ $CUSTOMIZE_ENC =~ (y|n) ]]; do
+		read -rp "Customize encryption settings? [y/n]: " -e -i n CUSTOMIZE_ENC
+	done
+	if [[ $CUSTOMIZE_ENC == "n" ]]; then
+		# Use default, sane and fast parameters
+		CIPHER="AES-128-GCM"
+		CERT_TYPE="1" # ECDSA
+		CERT_CURVE="prime256v1"
+		CC_CIPHER="TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256"
+		DH_TYPE="1" # ECDH
+		DH_CURVE="prime256v1"
+		HMAC_ALG="SHA256"
+		TLS_SIG="1" # tls-crypt
+	else
+		echo ""
+		echo "Choose which cipher you want to use for the data channel:"
+		echo "   1) AES-128-GCM (recommended)"
+		echo "   2) AES-192-GCM"
+		echo "   3) AES-256-GCM"
+		echo "   4) AES-128-CBC"
+		echo "   5) AES-192-CBC"
+		echo "   6) AES-256-CBC"
+		until [[ $CIPHER_CHOICE =~ ^[1-6]$ ]]; do
+			read -rp "Cipher [1-6]: " -e -i 1 CIPHER_CHOICE
+		done
+		case $CIPHER_CHOICE in
+		1)
+			CIPHER="AES-128-GCM"
+			;;
+		2)
+			CIPHER="AES-192-GCM"
+			;;
+		3)
+			CIPHER="AES-256-GCM"
+			;;
+		4)
+			CIPHER="AES-128-CBC"
+			;;
+		5)
+			CIPHER="AES-192-CBC"
+			;;
+		6)
+			CIPHER="AES-256-CBC"
+			;;
+		esac
+		echo ""
+		echo "Choose what kind of certificate you want to use:"
+		echo "   1) ECDSA (recommended)"
+		echo "   2) RSA"
+		until [[ $CERT_TYPE =~ ^[1-2]$ ]]; do
+			read -rp"Certificate key type [1-2]: " -e -i 1 CERT_TYPE
+		done
+		case $CERT_TYPE in
+		1)
+			echo ""
+			echo "Choose which curve you want to use for the certificate's key:"
+			echo "   1) prime256v1 (recommended)"
+			echo "   2) secp384r1"
+			echo "   3) secp521r1"
+			until [[ $CERT_CURVE_CHOICE =~ ^[1-3]$ ]]; do
+				read -rp"Curve [1-3]: " -e -i 1 CERT_CURVE_CHOICE
+			done
+			case $CERT_CURVE_CHOICE in
+			1)
+				CERT_CURVE="prime256v1"
+				;;
+			2)
+				CERT_CURVE="secp384r1"
+				;;
+			3)
+				CERT_CURVE="secp521r1"
+				;;
+			esac
+			;;
+		2)
+			echo ""
+			echo "Choose which size you want to use for the certificate's RSA key:"
+			echo "   1) 2048 bits (recommended)"
+			echo "   2) 3072 bits"
+			echo "   3) 4096 bits"
+			until [[ $RSA_KEY_SIZE_CHOICE =~ ^[1-3]$ ]]; do
+				read -rp "RSA key size [1-3]: " -e -i 1 RSA_KEY_SIZE_CHOICE
+			done
+			case $RSA_KEY_SIZE_CHOICE in
+			1)
+				RSA_KEY_SIZE="2048"
+				;;
+			2)
+				RSA_KEY_SIZE="3072"
+				;;
+			3)
+				RSA_KEY_SIZE="4096"
+				;;
+			esac
+			;;
+		esac
+		echo ""
+		echo "Choose which cipher you want to use for the control channel:"
+		case $CERT_TYPE in
+		1)
+			echo "   1) ECDHE-ECDSA-AES-128-GCM-SHA256 (recommended)"
+			echo "   2) ECDHE-ECDSA-AES-256-GCM-SHA384"
+			until [[ $CC_CIPHER_CHOICE =~ ^[1-2]$ ]]; do
+				read -rp"Control channel cipher [1-2]: " -e -i 1 CC_CIPHER_CHOICE
+			done
+			case $CC_CIPHER_CHOICE in
+			1)
+				CC_CIPHER="TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256"
+				;;
+			2)
+				CC_CIPHER="TLS-ECDHE-ECDSA-WITH-AES-256-GCM-SHA384"
+				;;
+			esac
+			;;
+		2)
+			echo "   1) ECDHE-RSA-AES-128-GCM-SHA256 (recommended)"
+			echo "   2) ECDHE-RSA-AES-256-GCM-SHA384"
+			until [[ $CC_CIPHER_CHOICE =~ ^[1-2]$ ]]; do
+				read -rp"Control channel cipher [1-2]: " -e -i 1 CC_CIPHER_CHOICE
+			done
+			case $CC_CIPHER_CHOICE in
+			1)
+				CC_CIPHER="TLS-ECDHE-RSA-WITH-AES-128-GCM-SHA256"
+				;;
+			2)
+				CC_CIPHER="TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384"
+				;;
+			esac
+			;;
+		esac
+		echo ""
+		echo "Choose what kind of Diffie-Hellman key you want to use:"
+		echo "   1) ECDH (recommended)"
+		echo "   2) DH"
+		until [[ $DH_TYPE =~ [1-2] ]]; do
+			read -rp"DH key type [1-2]: " -e -i 1 DH_TYPE
+		done
+		case $DH_TYPE in
+		1)
+			echo ""
+			echo "Choose which curve you want to use for the ECDH key:"
+			echo "   1) prime256v1 (recommended)"
+			echo "   2) secp384r1"
+			echo "   3) secp521r1"
+			while [[ $DH_CURVE_CHOICE != "1" && $DH_CURVE_CHOICE != "2" && $DH_CURVE_CHOICE != "3" ]]; do
+				read -rp"Curve [1-3]: " -e -i 1 DH_CURVE_CHOICE
+			done
+			case $DH_CURVE_CHOICE in
+			1)
+				DH_CURVE="prime256v1"
+				;;
+			2)
+				DH_CURVE="secp384r1"
+				;;
+			3)
+				DH_CURVE="secp521r1"
+				;;
+			esac
+			;;
+		2)
+			echo ""
+			echo "Choose what size of Diffie-Hellman key you want to use:"
+			echo "   1) 2048 bits (recommended)"
+			echo "   2) 3072 bits"
+			echo "   3) 4096 bits"
+			until [[ $DH_KEY_SIZE_CHOICE =~ ^[1-3]$ ]]; do
+				read -rp "DH key size [1-3]: " -e -i 1 DH_KEY_SIZE_CHOICE
+			done
+			case $DH_KEY_SIZE_CHOICE in
+			1)
+				DH_KEY_SIZE="2048"
+				;;
+			2)
+				DH_KEY_SIZE="3072"
+				;;
+			3)
+				DH_KEY_SIZE="4096"
+				;;
+			esac
+			;;
+		esac
+		echo ""
+		# The "auth" options behaves differently with AEAD ciphers
+		if [[ $CIPHER =~ CBC$ ]]; then
+			echo "The digest algorithm authenticates data channel packets and tls-auth packets from the control channel."
+		elif [[ $CIPHER =~ GCM$ ]]; then
+			echo "The digest algorithm authenticates tls-auth packets from the control channel."
+		fi
+		echo "Which digest algorithm do you want to use for HMAC?"
+		echo "   1) SHA-256 (recommended)"
+		echo "   2) SHA-384"
+		echo "   3) SHA-512"
+		until [[ $HMAC_ALG_CHOICE =~ ^[1-3]$ ]]; do
+			read -rp "Digest algorithm [1-3]: " -e -i 1 HMAC_ALG_CHOICE
+		done
+		case $HMAC_ALG_CHOICE in
+		1)
+			HMAC_ALG="SHA256"
+			;;
+		2)
+			HMAC_ALG="SHA384"
+			;;
+		3)
+			HMAC_ALG="SHA512"
+			;;
+		esac
+		echo ""
+		echo "You can add an additional layer of security to the control channel with tls-auth and tls-crypt"
+		echo "tls-auth authenticates the packets, while tls-crypt authenticate and encrypt them."
+		echo "   1) tls-crypt (recommended)"
+		echo "   2) tls-auth"
+		until [[ $TLS_SIG =~ [1-2] ]]; do
+			read -rp "Control channel additional security mechanism [1-2]: " -e -i 1 TLS_SIG
+		done
+	fi
+	echo ""
+	echo "Okay, that was all I needed. We are ready to setup your OpenVPN server now."
+	echo "You will be able to generate a client at the end of the installation."
+	APPROVE_INSTALL=${APPROVE_INSTALL:-n}
+	if [[ $APPROVE_INSTALL =~ n ]]; then
+		read -n1 -r -p "Press any key to continue..."
+	fi
+}
+
+function installOpenVPN() {
+	if [[ $AUTO_INSTALL == "y" ]]; then
+		# Set default choices so that no questions will be asked.
+		APPROVE_INSTALL=${APPROVE_INSTALL:-y}
+		APPROVE_IP=${APPROVE_IP:-y}
+		IPV6_SUPPORT=${IPV6_SUPPORT:-n}
+		PORT_CHOICE=${PORT_CHOICE:-1}
+		PROTOCOL_CHOICE=${PROTOCOL_CHOICE:-1}
+		DNS=${DNS:-1}
+		COMPRESSION_ENABLED=${COMPRESSION_ENABLED:-n}
+		CUSTOMIZE_ENC=${CUSTOMIZE_ENC:-n}
+		CLIENT=${CLIENT:-client}
+		PASS=${PASS:-1}
+		CONTINUE=${CONTINUE:-y}
+
+		# Behind NAT, we'll default to the publicly reachable IPv4/IPv6.
+		if [[ $IPV6_SUPPORT == "y" ]]; then
+			if ! PUBLIC_IP=$(curl -f --retry 5 --retry-connrefused https://ip.seeip.org); then
+				PUBLIC_IP=$(dig -6 TXT +short o-o.myaddr.l.google.com @ns1.google.com | tr -d '"')
+			fi
+		else
+			if ! PUBLIC_IP=$(curl -f --retry 5 --retry-connrefused -4 https://ip.seeip.org); then
+				PUBLIC_IP=$(dig -4 TXT +short o-o.myaddr.l.google.com @ns1.google.com | tr -d '"')
+			fi
+		fi
+		ENDPOINT=${ENDPOINT:-$PUBLIC_IP}
+	fi
+
+	# Run setup questions first, and set other variables if auto-install
+	installQuestions
+
+	# Get the "public" interface from the default route
+	NIC=$(ip -4 route ls | grep default | grep -Po '(?<=dev )(\S+)' | head -1)
+	if [[ -z $NIC ]] && [[ $IPV6_SUPPORT == 'y' ]]; then
+		NIC=$(ip -6 route show default | sed -ne 's/^default .* dev \([^ ]*\) .*$/\1/p')
+	fi
+
+	# $NIC can not be empty for script rm-openvpn-rules.sh
+	if [[ -z $NIC ]]; then
+		echo
+		echo "Can not detect public interface."
+		echo "This needs for setup MASQUERADE."
+		until [[ $CONTINUE =~ (y|n) ]]; do
+			read -rp "Continue? [y/n]: " -e CONTINUE
+		done
+		if [[ $CONTINUE == "n" ]]; then
+			exit 1
+		fi
+	fi
+
+	# If OpenVPN isn't installed yet, install it. This script is more-or-less
+	# idempotent on multiple runs, but will only install OpenVPN from upstream
+	# the first time.
+	if [[ ! -e /etc/openvpn/server.conf ]]; then
+		if [[ $OS =~ (debian|ubuntu) ]]; then
+			apt-get update
+			apt-get -y install ca-certificates gnupg
+			# We add the OpenVPN repo to get the latest version.
+			if [[ $VERSION_ID == "16.04" ]]; then
+				echo "deb http://build.openvpn.net/debian/openvpn/stable xenial main" >/etc/apt/sources.list.d/openvpn.list
+				wget -O - https://swupdate.openvpn.net/repos/repo-public.gpg | apt-key add -
+				apt-get update
+			fi
+			# Ubuntu > 16.04 and Debian > 8 have OpenVPN >= 2.4 without the need of a third party repository.
+			apt-get install -y openvpn iptables openssl wget ca-certificates curl
+		elif [[ $OS == 'centos' ]]; then
+			yum install -y epel-release
+			yum install -y openvpn iptables openssl wget ca-certificates curl tar 'policycoreutils-python*'
+		elif [[ $OS == 'oracle' ]]; then
+			yum install -y oracle-epel-release-el8
+			yum-config-manager --enable ol8_developer_EPEL
+			yum install -y openvpn iptables openssl wget ca-certificates curl tar policycoreutils-python-utils
+		elif [[ $OS == 'amzn' ]]; then
+			amazon-linux-extras install -y epel
+			yum install -y openvpn iptables openssl wget ca-certificates curl
+		elif [[ $OS == 'fedora' ]]; then
+			dnf install -y openvpn iptables openssl wget ca-certificates curl policycoreutils-python-utils
+		elif [[ $OS == 'arch' ]]; then
+			# Install required dependencies and upgrade the system
+			pacman --needed --noconfirm -Syu openvpn iptables openssl wget ca-certificates curl
+		fi
+		# An old version of easy-rsa was available by default in some openvpn packages
+		if [[ -d /etc/openvpn/easy-rsa/ ]]; then
+			rm -rf /etc/openvpn/easy-rsa/
+		fi
+	fi
+
+	# Find out if the machine uses nogroup or nobody for the permissionless group
+	if grep -qs "^nogroup:" /etc/group; then
+		NOGROUP=nogroup
+	else
+		NOGROUP=nobody
+	fi
+
+	# Install the latest version of easy-rsa from source, if not already installed.
+	if [[ ! -d /etc/openvpn/easy-rsa/ ]]; then
+		local version="3.1.2"
+		wget -O ~/easy-rsa.tgz https://github.com/OpenVPN/easy-rsa/releases/download/v${version}/EasyRSA-${version}.tgz
+		mkdir -p /etc/openvpn/easy-rsa
+		tar xzf ~/easy-rsa.tgz --strip-components=1 --no-same-owner --directory /etc/openvpn/easy-rsa
+		rm -f ~/easy-rsa.tgz
+
+		cd /etc/openvpn/easy-rsa/ || return
+		case $CERT_TYPE in
+		1)
+			echo "set_var EASYRSA_ALGO ec" >vars
+			echo "set_var EASYRSA_CURVE $CERT_CURVE" >>vars
+			;;
+		2)
+			echo "set_var EASYRSA_KEY_SIZE $RSA_KEY_SIZE" >vars
+			;;
+		esac
+
+		# Generate a random, alphanumeric identifier of 16 characters for CN and one for server name
+		SERVER_CN="cn_$(head /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)"
+		echo "$SERVER_CN" >SERVER_CN_GENERATED
+		SERVER_NAME="server_$(head /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)"
+		echo "$SERVER_NAME" >SERVER_NAME_GENERATED
+
+		# Create the PKI, set up the CA, the DH params and the server certificate
+		./easyrsa init-pki
+		./easyrsa --batch --req-cn="$SERVER_CN" build-ca nopass
+
+		if [[ $DH_TYPE == "2" ]]; then
+			# ECDH keys are generated on-the-fly so we don't need to generate them beforehand
+			openssl dhparam -out dh.pem $DH_KEY_SIZE
+		fi
+
+		./easyrsa --batch build-server-full "$SERVER_NAME" nopass
+		EASYRSA_CRL_DAYS=3650 ./easyrsa gen-crl
+
+		case $TLS_SIG in
+		1)
+			# Generate tls-crypt key
+			openvpn --genkey --secret /etc/openvpn/tls-crypt.key
+			;;
+		2)
+			# Generate tls-auth key
+			openvpn --genkey --secret /etc/openvpn/tls-auth.key
+			;;
+		esac
+	else
+		# If easy-rsa is already installed, grab the generated SERVER_NAME
+		# for client configs
+		cd /etc/openvpn/easy-rsa/ || return
+		SERVER_NAME=$(cat SERVER_NAME_GENERATED)
+	fi
+
+	# Move all the generated files
+	cp pki/ca.crt pki/private/ca.key "pki/issued/$SERVER_NAME.crt" "pki/private/$SERVER_NAME.key" /etc/openvpn/easy-rsa/pki/crl.pem /etc/openvpn
+	if [[ $DH_TYPE == "2" ]]; then
+		cp dh.pem /etc/openvpn
+	fi
+
+	# Make cert revocation list readable for non-root
+	chmod 644 /etc/openvpn/crl.pem
+
+	# Generate server.conf
+	echo "port $PORT" >/etc/openvpn/server.conf
+	if [[ $IPV6_SUPPORT == 'n' ]]; then
+		echo "proto $PROTOCOL" >>/etc/openvpn/server.conf
+	elif [[ $IPV6_SUPPORT == 'y' ]]; then
+		echo "proto ${PROTOCOL}6" >>/etc/openvpn/server.conf
+	fi
+
+	echo "dev tun
+user nobody
+group $NOGROUP
+persist-key
+persist-tun
+keepalive 10 120
+topology subnet
+server 10.8.0.0 255.255.255.0
+ifconfig-pool-persist ipp.txt" >>/etc/openvpn/server.conf
+
+	# DNS resolvers
+	case $DNS in
+	1) # Current system resolvers
+		# Locate the proper resolv.conf
+		# Needed for systems running systemd-resolved
+		if grep -q "127.0.0.53" "/etc/resolv.conf"; then
+			RESOLVCONF='/run/systemd/resolve/resolv.conf'
+		else
+			RESOLVCONF='/etc/resolv.conf'
+		fi
+		# Obtain the resolvers from resolv.conf and use them for OpenVPN
+		sed -ne 's/^nameserver[[:space:]]\+\([^[:space:]]\+\).*$/\1/p' $RESOLVCONF | while read -r line; do
+			# Copy, if it's a IPv4 |or| if IPv6 is enabled, IPv4/IPv6 does not matter
+			if [[ $line =~ ^[0-9.]*$ ]] || [[ $IPV6_SUPPORT == 'y' ]]; then
+				echo "push \"dhcp-option DNS $line\"" >>/etc/openvpn/server.conf
+			fi
+		done
+		;;
+	2) # Self-hosted DNS resolver (Unbound)
+		echo 'push "dhcp-option DNS 10.8.0.1"' >>/etc/openvpn/server.conf
+		if [[ $IPV6_SUPPORT == 'y' ]]; then
+			echo 'push "dhcp-option DNS fd42:42:42:42::1"' >>/etc/openvpn/server.conf
+		fi
+		;;
+	3) # Cloudflare
+		echo 'push "dhcp-option DNS 1.0.0.1"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 1.1.1.1"' >>/etc/openvpn/server.conf
+		;;
+	4) # Quad9
+		echo 'push "dhcp-option DNS 9.9.9.9"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 149.112.112.112"' >>/etc/openvpn/server.conf
+		;;
+	5) # Quad9 uncensored
+		echo 'push "dhcp-option DNS 9.9.9.10"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 149.112.112.10"' >>/etc/openvpn/server.conf
+		;;
+	6) # FDN
+		echo 'push "dhcp-option DNS 80.67.169.40"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 80.67.169.12"' >>/etc/openvpn/server.conf
+		;;
+	7) # DNS.WATCH
+		echo 'push "dhcp-option DNS 84.200.69.80"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 84.200.70.40"' >>/etc/openvpn/server.conf
+		;;
+	8) # OpenDNS
+		echo 'push "dhcp-option DNS 208.67.222.222"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 208.67.220.220"' >>/etc/openvpn/server.conf
+		;;
+	9) # Google
+		echo 'push "dhcp-option DNS 8.8.8.8"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 8.8.4.4"' >>/etc/openvpn/server.conf
+		;;
+	10) # Yandex Basic
+		echo 'push "dhcp-option DNS 77.88.8.8"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 77.88.8.1"' >>/etc/openvpn/server.conf
+		;;
+	11) # AdGuard DNS
+		echo 'push "dhcp-option DNS 94.140.14.14"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 94.140.15.15"' >>/etc/openvpn/server.conf
+		;;
+	12) # NextDNS
+		echo 'push "dhcp-option DNS 45.90.28.167"' >>/etc/openvpn/server.conf
+		echo 'push "dhcp-option DNS 45.90.30.167"' >>/etc/openvpn/server.conf
+		;;
+	13) # Custom DNS
+		echo "push \"dhcp-option DNS $DNS1\"" >>/etc/openvpn/server.conf
+		if [[ $DNS2 != "" ]]; then
+			echo "push \"dhcp-option DNS $DNS2\"" >>/etc/openvpn/server.conf
+		fi
+		;;
+	esac
+	echo 'push "redirect-gateway def1 bypass-dhcp"' >>/etc/openvpn/server.conf
+
+	# IPv6 network settings if needed
+	if [[ $IPV6_SUPPORT == 'y' ]]; then
+		echo 'server-ipv6 fd42:42:42:42::/112
+tun-ipv6
+push tun-ipv6
+push "route-ipv6 2000::/3"
+push "redirect-gateway ipv6"' >>/etc/openvpn/server.conf
+	fi
+
+	if [[ $COMPRESSION_ENABLED == "y" ]]; then
+		echo "compress $COMPRESSION_ALG" >>/etc/openvpn/server.conf
+	fi
+
+	if [[ $DH_TYPE == "1" ]]; then
+		echo "dh none" >>/etc/openvpn/server.conf
+		echo "ecdh-curve $DH_CURVE" >>/etc/openvpn/server.conf
+	elif [[ $DH_TYPE == "2" ]]; then
+		echo "dh dh.pem" >>/etc/openvpn/server.conf
+	fi
+
+	case $TLS_SIG in
+	1)
+		echo "tls-crypt tls-crypt.key" >>/etc/openvpn/server.conf
+		;;
+	2)
+		echo "tls-auth tls-auth.key 0" >>/etc/openvpn/server.conf
+		;;
+	esac
+
+	echo "crl-verify crl.pem
+ca ca.crt
+cert $SERVER_NAME.crt
+key $SERVER_NAME.key
+auth $HMAC_ALG
+cipher $CIPHER
+ncp-ciphers $CIPHER
+tls-server
+tls-version-min 1.2
+tls-cipher $CC_CIPHER
+client-config-dir /etc/openvpn/ccd
+status /var/log/openvpn/status.log
+verb 3" >>/etc/openvpn/server.conf
+
+	# Create client-config-dir dir
+	mkdir -p /etc/openvpn/ccd
+	# Create log dir
+	mkdir -p /var/log/openvpn
+
+	# Enable routing
+	echo 'net.ipv4.ip_forward=1' >/etc/sysctl.d/99-openvpn.conf
+	if [[ $IPV6_SUPPORT == 'y' ]]; then
+		echo 'net.ipv6.conf.all.forwarding=1' >>/etc/sysctl.d/99-openvpn.conf
+	fi
+	# Apply sysctl rules
+	sysctl --system
+
+	# If SELinux is enabled and a custom port was selected, we need this
+	if hash sestatus 2>/dev/null; then
+		if sestatus | grep "Current mode" | grep -qs "enforcing"; then
+			if [[ $PORT != '1194' ]]; then
+				semanage port -a -t openvpn_port_t -p "$PROTOCOL" "$PORT"
+			fi
+		fi
+	fi
+
+	# Finally, restart and enable OpenVPN
+	if [[ $OS == 'arch' || $OS == 'fedora' || $OS == 'centos' || $OS == 'oracle' ]]; then
+		# Don't modify package-provided service
+		cp /usr/lib/systemd/system/openvpn-server@.service /etc/systemd/system/openvpn-server@.service
+
+		# Workaround to fix OpenVPN service on OpenVZ
+		sed -i 's|LimitNPROC|#LimitNPROC|' /etc/systemd/system/openvpn-server@.service
+		# Another workaround to keep using /etc/openvpn/
+		sed -i 's|/etc/openvpn/server|/etc/openvpn|' /etc/systemd/system/openvpn-server@.service
+
+		systemctl daemon-reload
+		systemctl enable openvpn-server@server
+		systemctl restart openvpn-server@server
+	elif [[ $OS == "ubuntu" ]] && [[ $VERSION_ID == "16.04" ]]; then
+		# On Ubuntu 16.04, we use the package from the OpenVPN repo
+		# This package uses a sysvinit service
+		systemctl enable openvpn
+		systemctl start openvpn
+	else
+		# Don't modify package-provided service
+		cp /lib/systemd/system/openvpn\@.service /etc/systemd/system/openvpn\@.service
+
+		# Workaround to fix OpenVPN service on OpenVZ
+		sed -i 's|LimitNPROC|#LimitNPROC|' /etc/systemd/system/openvpn\@.service
+		# Another workaround to keep using /etc/openvpn/
+		sed -i 's|/etc/openvpn/server|/etc/openvpn|' /etc/systemd/system/openvpn\@.service
+
+		systemctl daemon-reload
+		systemctl enable openvpn@server
+		systemctl restart openvpn@server
+	fi
+
+	if [[ $DNS == 2 ]]; then
+		installUnbound
+	fi
+
+	# Add iptables rules in two scripts
+	mkdir -p /etc/iptables
+
+	# Script to add rules
+	echo "#!/bin/sh
+iptables -t nat -I POSTROUTING 1 -s 10.8.0.0/24 -o $NIC -j MASQUERADE
+iptables -I INPUT 1 -i tun0 -j ACCEPT
+iptables -I FORWARD 1 -i $NIC -o tun0 -j ACCEPT
+iptables -I FORWARD 1 -i tun0 -o $NIC -j ACCEPT
+iptables -I INPUT 1 -i $NIC -p $PROTOCOL --dport $PORT -j ACCEPT" >/etc/iptables/add-openvpn-rules.sh
+
+	if [[ $IPV6_SUPPORT == 'y' ]]; then
+		echo "ip6tables -t nat -I POSTROUTING 1 -s fd42:42:42:42::/112 -o $NIC -j MASQUERADE
+ip6tables -I INPUT 1 -i tun0 -j ACCEPT
+ip6tables -I FORWARD 1 -i $NIC -o tun0 -j ACCEPT
+ip6tables -I FORWARD 1 -i tun0 -o $NIC -j ACCEPT
+ip6tables -I INPUT 1 -i $NIC -p $PROTOCOL --dport $PORT -j ACCEPT" >>/etc/iptables/add-openvpn-rules.sh
+	fi
+
+	# Script to remove rules
+	echo "#!/bin/sh
+iptables -t nat -D POSTROUTING -s 10.8.0.0/24 -o $NIC -j MASQUERADE
+iptables -D INPUT -i tun0 -j ACCEPT
+iptables -D FORWARD -i $NIC -o tun0 -j ACCEPT
+iptables -D FORWARD -i tun0 -o $NIC -j ACCEPT
+iptables -D INPUT -i $NIC -p $PROTOCOL --dport $PORT -j ACCEPT" >/etc/iptables/rm-openvpn-rules.sh
+
+	if [[ $IPV6_SUPPORT == 'y' ]]; then
+		echo "ip6tables -t nat -D POSTROUTING -s fd42:42:42:42::/112 -o $NIC -j MASQUERADE
+ip6tables -D INPUT -i tun0 -j ACCEPT
+ip6tables -D FORWARD -i $NIC -o tun0 -j ACCEPT
+ip6tables -D FORWARD -i tun0 -o $NIC -j ACCEPT
+ip6tables -D INPUT -i $NIC -p $PROTOCOL --dport $PORT -j ACCEPT" >>/etc/iptables/rm-openvpn-rules.sh
+	fi
+
+	chmod +x /etc/iptables/add-openvpn-rules.sh
+	chmod +x /etc/iptables/rm-openvpn-rules.sh
+
+	# Handle the rules via a systemd script
+	echo "[Unit]
+Description=iptables rules for OpenVPN
+Before=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=oneshot
+ExecStart=/etc/iptables/add-openvpn-rules.sh
+ExecStop=/etc/iptables/rm-openvpn-rules.sh
+RemainAfterExit=yes
+
+[Install]
+WantedBy=multi-user.target" >/etc/systemd/system/iptables-openvpn.service
+
+	# Enable service and apply rules
+	systemctl daemon-reload
+	systemctl enable iptables-openvpn
+	systemctl start iptables-openvpn
+
+	# If the server is behind a NAT, use the correct IP address for the clients to connect to
+	if [[ $ENDPOINT != "" ]]; then
+		IP=$ENDPOINT
+	fi
+
+	# client-template.txt is created so we have a template to add further users later
+	echo "client" >/etc/openvpn/client-template.txt
+	if [[ $PROTOCOL == 'udp' ]]; then
+		echo "proto udp" >>/etc/openvpn/client-template.txt
+		echo "explicit-exit-notify" >>/etc/openvpn/client-template.txt
+	elif [[ $PROTOCOL == 'tcp' ]]; then
+		echo "proto tcp-client" >>/etc/openvpn/client-template.txt
+	fi
+	echo "remote $IP $PORT
+dev tun
+resolv-retry infinite
+nobind
+persist-key
+persist-tun
+remote-cert-tls server
+verify-x509-name $SERVER_NAME name
+auth $HMAC_ALG
+auth-nocache
+cipher $CIPHER
+tls-client
+tls-version-min 1.2
+tls-cipher $CC_CIPHER
+ignore-unknown-option block-outside-dns
+setenv opt block-outside-dns # Prevent Windows 10 DNS leak
+verb 3" >>/etc/openvpn/client-template.txt
+
+	if [[ $COMPRESSION_ENABLED == "y" ]]; then
+		echo "compress $COMPRESSION_ALG" >>/etc/openvpn/client-template.txt
+	fi
+
+	# Generate the custom client.ovpn
+	newClient
+	echo "If you want to add more clients, you simply need to run this script another time!"
+}
+
+function newClient() {
+	echo ""
+	echo "Tell me a name for the client."
+	echo "The name must consist of alphanumeric character. It may also include an underscore or a dash."
+
+	until [[ $CLIENT =~ ^[a-zA-Z0-9_-]+$ ]]; do
+		read -rp "Client name: " -e CLIENT
+	done
+
+	echo ""
+	echo "Do you want to protect the configuration file with a password?"
+	echo "(e.g. encrypt the private key with a password)"
+	echo "   1) Add a passwordless client"
+	echo "   2) Use a password for the client"
+
+	until [[ $PASS =~ ^[1-2]$ ]]; do
+		read -rp "Select an option [1-2]: " -e -i 1 PASS
+	done
+
+	CLIENTEXISTS=$(tail -n +2 /etc/openvpn/easy-rsa/pki/index.txt | grep -c -E "/CN=$CLIENT\$")
+	if [[ $CLIENTEXISTS == '1' ]]; then
+		echo ""
+		echo "The specified client CN was already found in easy-rsa, please choose another name."
+		exit
+	else
+		cd /etc/openvpn/easy-rsa/ || return
+		case $PASS in
+		1)
+			./easyrsa --batch build-client-full "$CLIENT" nopass
+			;;
+		2)
+			echo "⚠️ You will be asked for the client password below ⚠️"
+			./easyrsa --batch build-client-full "$CLIENT"
+			;;
+		esac
+		echo "Client $CLIENT added."
+	fi
+
+	# Home directory of the user, where the client configuration will be written
+	if [ -e "/home/${CLIENT}" ]; then
+		# if $1 is a user name
+		homeDir="/home/${CLIENT}"
+	elif [ "${SUDO_USER}" ]; then
+		# if not, use SUDO_USER
+		if [ "${SUDO_USER}" == "root" ]; then
+			# If running sudo as root
+			homeDir="/root"
+		else
+			homeDir="/home/${SUDO_USER}"
+		fi
+	else
+		# if not SUDO_USER, use /root
+		homeDir="/root"
+	fi
+
+	# Determine if we use tls-auth or tls-crypt
+	if grep -qs "^tls-crypt" /etc/openvpn/server.conf; then
+		TLS_SIG="1"
+	elif grep -qs "^tls-auth" /etc/openvpn/server.conf; then
+		TLS_SIG="2"
+	fi
+
+	# Generates the custom client.ovpn
+	cp /etc/openvpn/client-template.txt "$homeDir/$CLIENT.ovpn"
+	{
+		echo "<ca>"
+		cat "/etc/openvpn/easy-rsa/pki/ca.crt"
+		echo "</ca>"
+
+		echo "<cert>"
+		awk '/BEGIN/,/END CERTIFICATE/' "/etc/openvpn/easy-rsa/pki/issued/$CLIENT.crt"
+		echo "</cert>"
+
+		echo "<key>"
+		cat "/etc/openvpn/easy-rsa/pki/private/$CLIENT.key"
+		echo "</key>"
+
+		case $TLS_SIG in
+		1)
+			echo "<tls-crypt>"
+			cat /etc/openvpn/tls-crypt.key
+			echo "</tls-crypt>"
+			;;
+		2)
+			echo "key-direction 1"
+			echo "<tls-auth>"
+			cat /etc/openvpn/tls-auth.key
+			echo "</tls-auth>"
+			;;
+		esac
+	} >>"$homeDir/$CLIENT.ovpn"
+
+	echo ""
+	echo "The configuration file has been written to $homeDir/$CLIENT.ovpn."
+	echo "Download the .ovpn file and import it in your OpenVPN client."
+
+	exit 0
+}
+
+function revokeClient() {
+	NUMBEROFCLIENTS=$(tail -n +2 /etc/openvpn/easy-rsa/pki/index.txt | grep -c "^V")
+	if [[ $NUMBEROFCLIENTS == '0' ]]; then
+		echo ""
+		echo "You have no existing clients!"
+		exit 1
+	fi
+
+	echo ""
+	echo "Select the existing client certificate you want to revoke"
+	tail -n +2 /etc/openvpn/easy-rsa/pki/index.txt | grep "^V" | cut -d '=' -f 2 | nl -s ') '
+	until [[ $CLIENTNUMBER -ge 1 && $CLIENTNUMBER -le $NUMBEROFCLIENTS ]]; do
+		if [[ $CLIENTNUMBER == '1' ]]; then
+			read -rp "Select one client [1]: " CLIENTNUMBER
+		else
+			read -rp "Select one client [1-$NUMBEROFCLIENTS]: " CLIENTNUMBER
+		fi
+	done
+	CLIENT=$(tail -n +2 /etc/openvpn/easy-rsa/pki/index.txt | grep "^V" | cut -d '=' -f 2 | sed -n "$CLIENTNUMBER"p)
+	cd /etc/openvpn/easy-rsa/ || return
+	./easyrsa --batch revoke "$CLIENT"
+	EASYRSA_CRL_DAYS=3650 ./easyrsa gen-crl
+	rm -f /etc/openvpn/crl.pem
+	cp /etc/openvpn/easy-rsa/pki/crl.pem /etc/openvpn/crl.pem
+	chmod 644 /etc/openvpn/crl.pem
+	find /home/ -maxdepth 2 -name "$CLIENT.ovpn" -delete
+	rm -f "/root/$CLIENT.ovpn"
+	sed -i "/^$CLIENT,.*/d" /etc/openvpn/ipp.txt
+	cp /etc/openvpn/easy-rsa/pki/index.txt{,.bk}
+
+	echo ""
+	echo "Certificate for client $CLIENT revoked."
+}
+
+function removeUnbound() {
+	# Remove OpenVPN-related config
+	sed -i '/include: \/etc\/unbound\/openvpn.conf/d' /etc/unbound/unbound.conf
+	rm /etc/unbound/openvpn.conf
+
+	until [[ $REMOVE_UNBOUND =~ (y|n) ]]; do
+		echo ""
+		echo "If you were already using Unbound before installing OpenVPN, I removed the configuration related to OpenVPN."
+		read -rp "Do you want to completely remove Unbound? [y/n]: " -e REMOVE_UNBOUND
+	done
+
+	if [[ $REMOVE_UNBOUND == 'y' ]]; then
+		# Stop Unbound
+		systemctl stop unbound
+
+		if [[ $OS =~ (debian|ubuntu) ]]; then
+			apt-get remove --purge -y unbound
+		elif [[ $OS == 'arch' ]]; then
+			pacman --noconfirm -R unbound
+		elif [[ $OS =~ (centos|amzn|oracle) ]]; then
+			yum remove -y unbound
+		elif [[ $OS == 'fedora' ]]; then
+			dnf remove -y unbound
+		fi
+
+		rm -rf /etc/unbound/
+
+		echo ""
+		echo "Unbound removed!"
+	else
+		systemctl restart unbound
+		echo ""
+		echo "Unbound wasn't removed."
+	fi
+}
+
+function removeOpenVPN() {
+	echo ""
+	read -rp "Do you really want to remove OpenVPN? [y/n]: " -e -i n REMOVE
+	if [[ $REMOVE == 'y' ]]; then
+		# Get OpenVPN port from the configuration
+		PORT=$(grep '^port ' /etc/openvpn/server.conf | cut -d " " -f 2)
+		PROTOCOL=$(grep '^proto ' /etc/openvpn/server.conf | cut -d " " -f 2)
+
+		# Stop OpenVPN
+		if [[ $OS =~ (fedora|arch|centos|oracle) ]]; then
+			systemctl disable openvpn-server@server
+			systemctl stop openvpn-server@server
+			# Remove customised service
+			rm /etc/systemd/system/openvpn-server@.service
+		elif [[ $OS == "ubuntu" ]] && [[ $VERSION_ID == "16.04" ]]; then
+			systemctl disable openvpn
+			systemctl stop openvpn
+		else
+			systemctl disable openvpn@server
+			systemctl stop openvpn@server
+			# Remove customised service
+			rm /etc/systemd/system/openvpn\@.service
+		fi
+
+		# Remove the iptables rules related to the script
+		systemctl stop iptables-openvpn
+		# Cleanup
+		systemctl disable iptables-openvpn
+		rm /etc/systemd/system/iptables-openvpn.service
+		systemctl daemon-reload
+		rm /etc/iptables/add-openvpn-rules.sh
+		rm /etc/iptables/rm-openvpn-rules.sh
+
+		# SELinux
+		if hash sestatus 2>/dev/null; then
+			if sestatus | grep "Current mode" | grep -qs "enforcing"; then
+				if [[ $PORT != '1194' ]]; then
+					semanage port -d -t openvpn_port_t -p "$PROTOCOL" "$PORT"
+				fi
+			fi
+		fi
+
+		if [[ $OS =~ (debian|ubuntu) ]]; then
+			apt-get remove --purge -y openvpn
+			if [[ -e /etc/apt/sources.list.d/openvpn.list ]]; then
+				rm /etc/apt/sources.list.d/openvpn.list
+				apt-get update
+			fi
+		elif [[ $OS == 'arch' ]]; then
+			pacman --noconfirm -R openvpn
+		elif [[ $OS =~ (centos|amzn|oracle) ]]; then
+			yum remove -y openvpn
+		elif [[ $OS == 'fedora' ]]; then
+			dnf remove -y openvpn
+		fi
+
+		# Cleanup
+		find /home/ -maxdepth 2 -name "*.ovpn" -delete
+		find /root/ -maxdepth 1 -name "*.ovpn" -delete
+		rm -rf /etc/openvpn
+		rm -rf /usr/share/doc/openvpn*
+		rm -f /etc/sysctl.d/99-openvpn.conf
+		rm -rf /var/log/openvpn
+
+		# Unbound
+		if [[ -e /etc/unbound/openvpn.conf ]]; then
+			removeUnbound
+		fi
+		echo ""
+		echo "OpenVPN removed!"
+	else
+		echo ""
+		echo "Removal aborted!"
+	fi
+}
+
+function manageMenu() {
+	echo "Welcome to OpenVPN-install!"
+	echo "The git repository is available at: https://github.com/angristan/openvpn-install"
+	echo ""
+	echo "It looks like OpenVPN is already installed."
+	echo ""
+	echo "What do you want to do?"
+	echo "   1) Add a new user"
+	echo "   2) Revoke existing user"
+	echo "   3) Remove OpenVPN"
+	echo "   4) Exit"
+	until [[ $MENU_OPTION =~ ^[1-4]$ ]]; do
+		read -rp "Select an option [1-4]: " MENU_OPTION
+	done
+
+	case $MENU_OPTION in
+	1)
+		newClient
+		;;
+	2)
+		revokeClient
+		;;
+	3)
+		removeOpenVPN
+		;;
+	4)
+		exit 0
+		;;
+	esac
+}
+
+# Check for root, TUN, OS...
+initialCheck
+
+# Check if OpenVPN is already installed
+if [[ -e /etc/openvpn/server.conf && $AUTO_INSTALL != "y" ]]; then
+	manageMenu
+else
+	installOpenVPN
+fi