#!/bin/bash # Secure OpenVPN server installer for Debian, Ubuntu, CentOS, Amazon Linux 2, Fedora and Arch Linux # https://github.com/angristan/openvpn-install function isRoot () { if [ "$EUID" -ne 0 ]; then return 1 fi } function tunAvailable () { if [ ! -e /dev/net/tun ]; then return 1 fi } function checkOS () { if [[ -e /etc/debian_version ]]; then OS="debian" # shellcheck disable=SC1091 source /etc/os-release if [[ "$ID" == "debian" || "$ID" == "raspbian" ]]; then if [[ ! $VERSION_ID =~ (8|9|10) ]]; 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." echo "Keep in mind they are not supported, though." 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" if [[ ! $VERSION_ID =~ (16.04|18.04|19.04) ]]; then echo "⚠️ Your version of Ubuntu is not supported." echo "" echo "However, if you're using Ubuntu > 17 or beta, then you can continue." echo "Keep in mind they are not supported, though." 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 # shellcheck disable=SC1091 source /etc/os-release if [[ "$ID" = "fedora" ]]; then OS="fedora" fi if [[ "$ID" = "centos" ]]; then OS="centos" if [[ ! $VERSION_ID =~ (7|8) ]]; then echo "⚠️ Your version of CentOS is not supported." echo "" echo "The script only support CentOS 7." echo "" exit 1 fi fi if [[ "$ID" = "amzn" ]]; then OS="amzn" if [[ ! $VERSION_ID == "2" ]]; then echo "⚠️ Your version of Amazon Linux is not supported." echo "" echo "The script only support Amazon Linux 2." echo "" exit 1 fi fi elif [[ -e /etc/arch-release ]]; then OS=arch else echo "Looks like you aren't running this installer on a Debian, Ubuntu, Fedora, CentOS, Amazon Linux 2 or Arch Linux system" exit 1 fi } function initialCheck () { if ! isRoot; then echo "Sorry, you need to run this as root" exit 1 fi if ! tunAvailable; then echo "TUN is not available" exit 1 fi checkOS } function installUnbound () { if [[ ! -e /etc/unbound/unbound.conf ]]; then if [[ "$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 [[ "$OS" =~ (centos|amzn) ]]; then yum install -y unbound # Configuration sed -i 's|# interface: 0.0.0.0$|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 [[ "$OS" = "arch" ]]; then pacman -Syu --noconfirm unbound # Get root servers list curl -o /etc/unbound/root.hints https://www.internic.net/domain/named.cache mv /etc/unbound/unbound.conf /etc/unbound/unbound.conf.old echo 'server: use-syslog: yes do-daemonize: no username: "unbound" directory: "/etc/unbound" trust-anchor-file: trusted-key.key root-hints: root.hints interface: 10.8.0.1 access-control: 10.8.0.1/24 allow port: 53 num-threads: 2 use-caps-for-id: yes harden-glue: yes hide-identity: yes hide-version: yes qname-minimisation: yes prefetch: yes' > /etc/unbound/unbound.conf fi if [[ ! "$OS" =~ (fedora|centos|amzn) ]];then # DNS Rebinding fix echo "private-address: 10.0.0.0/8 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: 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 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=$(ip addr | grep 'inet' | grep -v inet6 | grep -vE '127\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | grep -oE '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | head -1) APPROVE_IP=${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." until [[ "$ENDPOINT" != "" ]]; do read -rp "Public IPv4 address or hostname: " -e ENDPOINT done fi echo "" echo "Checking for IPv6 connectivity..." echo "" # "ping6" and "ping -6" availability varies depending on the distribution if type ping6 > /dev/null 2>&1; then PING6="ping6 -c3 ipv6.google.com > /dev/null 2>&1" else PING6="ping -6 -c3 ipv6.google.com > /dev/null 2>&1" fi if eval "$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 3 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 make 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. PUBLIC_IPV4=$(curl ifconfig.co) ENDPOINT=${ENDPOINT:-$PUBLIC_IPV4} fi # Run setup questions first, and set other variales if auto-install installQuestions # Get the "public" interface from the default route NIC=$(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 [[ "$OS" =~ (debian|ubuntu) ]]; then apt-get update apt-get -y install ca-certificates gnupg # We add the OpenVPN repo to get the latest version. if [[ "$VERSION_ID" = "8" ]]; then echo "deb http://build.openvpn.net/debian/openvpn/stable jessie 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 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 [[ "$OS" = 'amzn' ]]; then amazon-linux-extras install -y epel yum install -y openvpn iptables openssl wget ca-certificates curl elif [[ "$OS" = 'fedora' ]]; then dnf install -y openvpn iptables openssl wget ca-certificates curl elif [[ "$OS" = 'arch' ]]; then # Install required dependencies and upgrade the system pacman --needed --noconfirm -Syu openvpn iptables openssl wget ca-certificates curl fi # Find out if the machine uses nogroup or nobody for the permissionless group if grep -qs "^nogroup:" /etc/group; then NOGROUP=nogroup else NOGROUP=nobody fi # An old version of easy-rsa was available by default in some openvpn packages if [[ -d /etc/openvpn/easy-rsa/ ]]; then rm -rf /etc/openvpn/easy-rsa/ fi # Install the latest version of easy-rsa from source local version="3.0.6" wget -O ~/EasyRSA-unix-v${version}.tgz https://github.com/OpenVPN/easy-rsa/releases/download/v${version}/EasyRSA-unix-v${version}.tgz tar xzf ~/EasyRSA-unix-v${version}.tgz -C ~/ mv ~/EasyRSA-v${version} /etc/openvpn/easy-rsa chown -R root:root /etc/openvpn/easy-rsa/ rm -f ~/EasyRSA-unix-v${version}.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)" SERVER_NAME="server_$(head /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 16 | head -n 1)" echo "set_var EASYRSA_REQ_CN $SERVER_CN" >> vars # Create the PKI, set up the CA, the DH params and the server certificate ./easyrsa init-pki # Workaround to remove unharmful error until easy-rsa 3.0.7 # https://github.com/OpenVPN/easy-rsa/issues/261 sed -i 's/^RANDFILE/#RANDFILE/g' pki/openssl-easyrsa.cnf ./easyrsa --batch 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 $DH_KEY_SIZE fi ./easyrsa build-server-full "$SERVER_NAME" nopass EASYRSA_CRL_DAYS=3650 ./easyrsa gen-crl case $TLS_SIG in 1) # Generate tls-crypt key openvpn --genkey --secret /etc/openvpn/tls-crypt.key ;; 2) # Generate tls-auth key openvpn --genkey --secret /etc/openvpn/tls-auth.key ;; esac # Move all the generated files cp pki/ca.crt pki/private/ca.key "pki/issued/$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 grep -v '#' $RESOLVCONF | grep 'nameserver' | grep -E -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | while read -r line; do echo "push \"dhcp-option DNS $line\"" >> /etc/openvpn/server.conf done ;; 2) # Self-hosted DNS resolver (Unbound) echo 'push "dhcp-option DNS 10.8.0.1"' >> /etc/openvpn/server.conf ;; 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 176.103.130.130"' >> /etc/openvpn/server.conf echo 'push "dhcp-option DNS 176.103.130.131"' >> /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 0" >> /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 $CC_CIPHER status /var/log/openvpn/status.log verb 3" >> /etc/openvpn/server.conf # Create log dir mkdir -p /var/log/openvpn # Enable routing echo 'net.ipv4.ip_forward=1' >> /etc/sysctl.d/20-openvpn.conf if [[ "$IPV6_SUPPORT" = 'y' ]]; then echo 'net.ipv6.conf.all.forwarding=1' >> /etc/sysctl.d/20-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' ]]; 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 # On fedora, the service hardcodes the ciphers. We want to manage the cipher ourselves, so we remove it from the service if [[ "$OS" == "fedora" ]];then sed -i 's|--cipher AES-256-GCM --ncp-ciphers AES-256-GCM:AES-128-GCM:AES-256-CBC:AES-128-CBC:BF-CBC||' /etc/systemd/system/openvpn-server@.service fi systemctl daemon-reload systemctl enable openvpn-server@server systemctl restart openvpn-server@server elif [[ "$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" >> /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 $NIC -j ACCEPT" >> /etc/iptables/rm-openvpn-rules.sh fi chmod +x /etc/iptables/add-openvpn-rules.sh chmod +x /etc/iptables/rm-openvpn-rules.sh # Handle the rules via a systemd script echo "[Unit] Description=iptables rules for OpenVPN Before=network-online.target Wants=network-online.target [Service] Type=oneshot ExecStart=/etc/iptables/add-openvpn-rules.sh ExecStop=/etc/iptables/rm-openvpn-rules.sh RemainAfterExit=yes [Install] WantedBy=multi-user.target" > /etc/systemd/system/iptables-openvpn.service # Enable service and apply rules systemctl daemon-reload systemctl enable iptables-openvpn systemctl start iptables-openvpn # If the server is behind a NAT, use the correct IP address for the clients to connect to if [[ "$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 setenv opt block-outside-dns # Prevent Windows 10 DNS leak verb 3" >> /etc/openvpn/client-template.txt if [[ $COMPRESSION_ENABLED == "y" ]]; then echo "compress $COMPRESSION_ALG" >> /etc/openvpn/client-template.txt fi # Generate the custom client.ovpn newClient echo "If you want to add more clients, you simply need to run this script another time!" } function newClient () { echo "" echo "Tell me a name for the client." echo "Use one word only, no special characters." until [[ "$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 cd /etc/openvpn/easy-rsa/ || return case $PASS in 1) ./easyrsa build-client-full "$CLIENT" nopass ;; 2) echo "⚠️ You will be asked for the client password below ⚠️" ./easyrsa build-client-full "$CLIENT" ;; esac # Home directory of the user, where the client configuration (.ovpn) will be written if [ -e "/home/$CLIENT" ]; then # if $1 is a user name homeDir="/home/$CLIENT" elif [ "${SUDO_USER}" ]; then # if not, use SUDO_USER homeDir="/home/${SUDO_USER}" 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 "" cat "/etc/openvpn/easy-rsa/pki/ca.crt" echo "" echo "" awk '/BEGIN/,/END/' "/etc/openvpn/easy-rsa/pki/issued/$CLIENT.crt" echo "" echo "" cat "/etc/openvpn/easy-rsa/pki/private/$CLIENT.key" echo "" case $TLS_SIG in 1) echo "" cat /etc/openvpn/tls-crypt.key echo "" ;; 2) echo "key-direction 1" echo "" cat /etc/openvpn/tls-auth.key echo "" ;; esac } >> "$homeDir/$CLIENT.ovpn" echo "" echo "Client $CLIENT added, the configuration file is available at $homeDir/$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 ') ' if [[ "$NUMBEROFCLIENTS" = '1' ]]; then read -rp "Select one client [1]: " CLIENTNUMBER else read -rp "Select one client [1-$NUMBEROFCLIENTS]: " CLIENTNUMBER fi 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 "$CLIENT" EASYRSA_CRL_DAYS=3650 ./easyrsa gen-crl # Cleanup rm -f "pki/reqs/$CLIENT.req" rm -f "pki/private/$CLIENT.key" rm -f "pki/issued/$CLIENT.crt" 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 "s|^$CLIENT,.*||" /etc/openvpn/ipp.txt echo "" echo "Certificate for client $CLIENT revoked." } function removeUnbound () { # Remove OpenVPN-related config sed -i 's|include: \/etc\/unbound\/openvpn.conf||' /etc/unbound/unbound.conf rm /etc/unbound/openvpn.conf systemctl restart unbound 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 [[ "$OS" =~ (debian|ubuntu) ]]; then apt-get autoremove --purge -y unbound elif [[ "$OS" = 'arch' ]]; then pacman --noconfirm -R unbound elif [[ "$OS" =~ (centos|amzn) ]]; then yum remove -y unbound elif [[ "$OS" = 'fedora' ]]; then dnf remove -y unbound fi rm -rf /etc/unbound/ echo "" echo "Unbound removed!" else echo "" echo "Unbound wasn't removed." fi } function removeOpenVPN () { echo "" # shellcheck disable=SC2034 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) # Stop OpenVPN if [[ "$OS" =~ (fedora|arch|centos) ]]; then systemctl disable openvpn-server@server systemctl stop openvpn-server@server # Remove customised service rm /etc/systemd/system/openvpn-server@.service elif [[ "$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 udp "$PORT" fi fi fi if [[ "$OS" =~ (debian|ubuntu) ]]; then apt-get autoremove --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) ]]; then yum remove -y openvpn elif [[ "$OS" = 'fedora' ]]; then dnf remove -y openvpn fi # Cleanup find /home/ -maxdepth 2 -name "*.ovpn" -delete find /root/ -maxdepth 1 -name "*.ovpn" -delete rm -rf /etc/openvpn rm -rf /usr/share/doc/openvpn* rm -f /etc/sysctl.d/20-openvpn.conf rm -rf /var/log/openvpn # Unbound if [[ -e /etc/unbound/openvpn.conf ]]; then removeUnbound fi echo "" echo "OpenVPN removed!" else echo "" echo "Removal aborted!" fi } function manageMenu () { clear echo "Welcome to OpenVPN-install!" echo "The git repository is available at: https://github.com/angristan/openvpn-install" echo "" echo "It looks like OpenVPN is already installed." echo "" echo "What do you want to do?" echo " 1) Add a new user" echo " 2) Revoke existing user" echo " 3) Remove OpenVPN" echo " 4) Exit" until [[ "$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 ]]; then manageMenu else installOpenVPN fi