diff --git a/openvpn-install.sh b/openvpn-install.sh new file mode 100755 index 0000000..bc593c0 --- /dev/null +++ b/openvpn-install.sh @@ -0,0 +1,419 @@ +#!/bin/bash +# OpenVPN road warrior installer for Debian, Ubuntu and CentOS + +# This script will work on Debian, Ubuntu, CentOS and probably other distros +# of the same families, although no support is offered for them. It isn't +# bulletproof but it will probably work if you simply want to setup a VPN on +# your Debian/Ubuntu/CentOS box. It has been designed to be as unobtrusive and +# universal as possible. + + +# Detect Debian users running the script with "sh" instead of bash +if readlink /proc/$$/exe | grep -qs "dash"; then + echo "This script needs to be run with bash, not sh" + exit 1 +fi + +if [[ "$EUID" -ne 0 ]]; then + echo "Sorry, you need to run this as root" + exit 2 +fi + +if [[ ! -e /dev/net/tun ]]; then + echo "The TUN device is not available +You need to enable TUN before running this script" + exit 3 +fi + +if grep -qs "CentOS release 5" "/etc/redhat-release"; then + echo "CentOS 5 is too old and not supported" + exit 4 +fi +if [[ -e /etc/debian_version ]]; then + OS=debian + GROUPNAME=nogroup + RCLOCAL='/etc/rc.local' +elif [[ -e /etc/centos-release || -e /etc/redhat-release ]]; then + OS=centos + GROUPNAME=nobody + RCLOCAL='/etc/rc.d/rc.local' +else + echo "Looks like you aren't running this installer on Debian, Ubuntu or CentOS" + exit 5 +fi + +newclient () { + # Generates the custom client.ovpn + cp /etc/openvpn/client-common.txt ~/$1.ovpn + echo "" >> ~/$1.ovpn + cat /etc/openvpn/easy-rsa/pki/ca.crt >> ~/$1.ovpn + echo "" >> ~/$1.ovpn + echo "" >> ~/$1.ovpn + cat /etc/openvpn/easy-rsa/pki/issued/$1.crt >> ~/$1.ovpn + echo "" >> ~/$1.ovpn + echo "" >> ~/$1.ovpn + cat /etc/openvpn/easy-rsa/pki/private/$1.key >> ~/$1.ovpn + echo "" >> ~/$1.ovpn + echo "" >> ~/$1.ovpn + cat /etc/openvpn/ta.key >> ~/$1.ovpn + echo "" >> ~/$1.ovpn +} + +# Try to get our IP from the system and fallback to the Internet. +# I do this to make the script compatible with NATed servers (lowendspirit.com) +# and to avoid getting an IPv6. +IP=$(ip addr | grep 'inet' | grep -v inet6 | grep -vE '127\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | grep -o -E '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | head -1) +if [[ "$IP" = "" ]]; then + IP=$(wget -4qO- "http://whatismyip.akamai.com/") +fi + +if [[ -e /etc/openvpn/server.conf ]]; then + while : + do + clear + echo "Looks like OpenVPN is already installed" + echo "" + echo "What do you want to do?" + echo " 1) Add a new user" + echo " 2) Revoke an existing user" + echo " 3) Remove OpenVPN" + echo " 4) Exit" + read -p "Select an option [1-4]: " option + case $option in + 1) + echo "" + echo "Tell me a name for the client certificate" + echo "Please, use one word only, no special characters" + read -p "Client name: " -e -i client CLIENT + cd /etc/openvpn/easy-rsa/ + ./easyrsa build-client-full $CLIENT nopass + # Generates the custom client.ovpn + newclient "$CLIENT" + echo "" + echo "Client $CLIENT added, configuration is available at" ~/"$CLIENT.ovpn" + exit + ;; + 2) + # This option could be documented a bit better and maybe even be simplimplified + # ...but what can I say, I want some sleep too + 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 6 + 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 [[ "$NUMBEROFCLIENTS" = '1' ]]; then + read -p "Select one client [1]: " CLIENTNUMBER + else + read -p "Select one client [1-$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/ + ./easyrsa --batch revoke $CLIENT + ./easyrsa gen-crl + rm -rf pki/reqs/$CLIENT.req + rm -rf pki/private/$CLIENT.key + rm -rf pki/issued/$CLIENT.crt + rm -rf /etc/openvpn/crl.pem + cp /etc/openvpn/easy-rsa/pki/crl.pem /etc/openvpn/crl.pem + # CRL is read with each client connection, when OpenVPN is dropped to nobody + chown nobody:$GROUPNAME /etc/openvpn/crl.pem + echo "" + echo "Certificate for client $CLIENT revoked" + exit + ;; + 3) + echo "" + read -p "Do you really want to remove OpenVPN? [y/n]: " -e -i n REMOVE + if [[ "$REMOVE" = 'y' ]]; then + PORT=$(grep '^port ' /etc/openvpn/server.conf | cut -d " " -f 2) + PROTOCOL=$(grep '^proto ' /etc/openvpn/server.conf | cut -d " " -f 2) + if pgrep firewalld; then + IP=$(firewall-cmd --direct --get-rules ipv4 nat POSTROUTING | grep '\-s 10.8.0.0/24 '"'"'!'"'"' -d 10.8.0.0/24 -j SNAT --to ' | cut -d " " -f 10) + # Using both permanent and not permanent rules to avoid a firewalld reload. + firewall-cmd --zone=public --remove-port=$PORT/$PROTOCOL + firewall-cmd --zone=trusted --remove-source=10.8.0.0/24 + firewall-cmd --permanent --zone=public --remove-port=$PORT/$PROTOCOL + firewall-cmd --permanent --zone=trusted --remove-source=10.8.0.0/24 + firewall-cmd --direct --remove-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $IP + firewall-cmd --permanent --direct --remove-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $IP + else + IP=$(grep 'iptables -t nat -A POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to ' $RCLOCAL | cut -d " " -f 11) + iptables -t nat -D POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $IP + sed -i '/iptables -t nat -A POSTROUTING -s 10.8.0.0\/24 ! -d 10.8.0.0\/24 -j SNAT --to /d' $RCLOCAL + if iptables -L -n | grep -qE '^ACCEPT'; then + iptables -D INPUT -p $PROTOCOL --dport $PORT -j ACCEPT + iptables -D FORWARD -s 10.8.0.0/24 -j ACCEPT + iptables -D FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT + sed -i "/iptables -I INPUT -p $PROTOCOL --dport $PORT -j ACCEPT/d" $RCLOCAL + sed -i "/iptables -I FORWARD -s 10.8.0.0\/24 -j ACCEPT/d" $RCLOCAL + sed -i "/iptables -I FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT/d" $RCLOCAL + fi + fi + if hash sestatus 2>/dev/null; then + if sestatus | grep "Current mode" | grep -qs "enforcing"; then + if [[ "$PORT" != '1194' || "$PROTOCOL" = 'tcp' ]]; then + semanage port -d -t openvpn_port_t -p $PROTOCOL $PORT + fi + fi + fi + if [[ "$OS" = 'debian' ]]; then + apt-get remove --purge -y openvpn openvpn-blacklist + else + yum remove openvpn -y + fi + rm -rf /etc/openvpn + rm -rf /usr/share/doc/openvpn* + echo "" + echo "OpenVPN removed!" + else + echo "" + echo "Removal aborted!" + fi + exit + ;; + 4) exit;; + esac + done +else + clear + echo 'Welcome to this quick OpenVPN "road warrior" installer' + echo "" + # OpenVPN setup and first user creation + 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 "First I need to know the IPv4 address of the network interface you want OpenVPN" + echo "listening to." + read -p "IP address: " -e -i $IP IP + echo "" + echo "Which protocol do you want for OpenVPN connections?" + echo " 1) UDP (recommended)" + echo " 2) TCP" + read -p "Protocol [1-2]: " -e -i 1 PROTOCOL + case $PROTOCOL in + 1) + PROTOCOL=udp + ;; + 2) + PROTOCOL=tcp + ;; + esac + echo "" + echo "What port do you want OpenVPN listening to?" + read -p "Port: " -e -i 1194 PORT + echo "" + echo "Which DNS do you want to use with the VPN?" + echo " 1) Current system resolvers" + echo " 2) Google" + echo " 3) OpenDNS" + echo " 4) NTT" + echo " 5) Hurricane Electric" + echo " 6) Verisign" + read -p "DNS [1-6]: " -e -i 1 DNS + echo "" + echo "Finally, tell me your name for the client certificate" + echo "Please, use one word only, no special characters" + read -p "Client name: " -e -i client CLIENT + echo "" + echo "Okay, that was all I needed. We are ready to setup your OpenVPN server now" + read -n1 -r -p "Press any key to continue..." + if [[ "$OS" = 'debian' ]]; then + apt-get update + apt-get install openvpn iptables openssl ca-certificates -y + else + # Else, the distro is CentOS + yum install epel-release -y + yum install openvpn iptables openssl wget ca-certificates -y + 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 + # Get easy-rsa + wget -O ~/EasyRSA-3.0.1.tgz "https://github.com/OpenVPN/easy-rsa/releases/download/3.0.1/EasyRSA-3.0.1.tgz" + tar xzf ~/EasyRSA-3.0.1.tgz -C ~/ + mv ~/EasyRSA-3.0.1/ /etc/openvpn/ + mv /etc/openvpn/EasyRSA-3.0.1/ /etc/openvpn/easy-rsa/ + chown -R root:root /etc/openvpn/easy-rsa/ + rm -rf ~/EasyRSA-3.0.1.tgz + cd /etc/openvpn/easy-rsa/ + # Create the PKI, set up the CA, the DH params and the server + client certificates + ./easyrsa init-pki + ./easyrsa --batch build-ca nopass + ./easyrsa gen-dh + ./easyrsa build-server-full server nopass + ./easyrsa build-client-full $CLIENT nopass + ./easyrsa gen-crl + # Move the stuff we need + cp pki/ca.crt pki/private/ca.key pki/dh.pem pki/issued/server.crt pki/private/server.key /etc/openvpn/easy-rsa/pki/crl.pem /etc/openvpn + # CRL is read with each client connection, when OpenVPN is dropped to nobody + chown nobody:$GROUPNAME /etc/openvpn/crl.pem + # Generate key for tls-auth + openvpn --genkey --secret /etc/openvpn/ta.key + # Generate server.conf + echo "port $PORT +proto $PROTOCOL +dev tun +sndbuf 0 +rcvbuf 0 +ca ca.crt +cert server.crt +key server.key +dh dh.pem +auth SHA512 +tls-auth ta.key 0 +topology subnet +server 10.8.0.0 255.255.255.0 +ifconfig-pool-persist ipp.txt" > /etc/openvpn/server.conf + echo 'push "redirect-gateway def1 bypass-dhcp"' >> /etc/openvpn/server.conf + # DNS + case $DNS in + 1) + # Obtain the resolvers from resolv.conf and use them for OpenVPN + grep -v '#' /etc/resolv.conf | grep 'nameserver' | grep -E -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | while read line; do + echo "push \"dhcp-option DNS $line\"" >> /etc/openvpn/server.conf + done + ;; + 2) + 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 + ;; + 3) + 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 + ;; + 4) + echo 'push "dhcp-option DNS 129.250.35.250"' >> /etc/openvpn/server.conf + echo 'push "dhcp-option DNS 129.250.35.251"' >> /etc/openvpn/server.conf + ;; + 5) + echo 'push "dhcp-option DNS 74.82.42.42"' >> /etc/openvpn/server.conf + ;; + 6) + echo 'push "dhcp-option DNS 64.6.64.6"' >> /etc/openvpn/server.conf + echo 'push "dhcp-option DNS 64.6.65.6"' >> /etc/openvpn/server.conf + ;; + esac + echo "keepalive 10 120 +cipher AES-256-CBC +comp-lzo +user nobody +group $GROUPNAME +persist-key +persist-tun +status openvpn-status.log +verb 3 +crl-verify crl.pem" >> /etc/openvpn/server.conf + # Enable net.ipv4.ip_forward for the system + sed -i '/\/c\net.ipv4.ip_forward=1' /etc/sysctl.conf + if ! grep -q "\" /etc/sysctl.conf; then + echo 'net.ipv4.ip_forward=1' >> /etc/sysctl.conf + fi + # Avoid an unneeded reboot + echo 1 > /proc/sys/net/ipv4/ip_forward + if pgrep firewalld; then + # Using both permanent and not permanent rules to avoid a firewalld + # reload. + # We don't use --add-service=openvpn because that would only work with + # the default port and protocol. + firewall-cmd --zone=public --add-port=$PORT/$PROTOCOL + firewall-cmd --zone=trusted --add-source=10.8.0.0/24 + firewall-cmd --permanent --zone=public --add-port=$PORT/$PROTOCOL + firewall-cmd --permanent --zone=trusted --add-source=10.8.0.0/24 + # Set NAT for the VPN subnet + firewall-cmd --direct --add-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $IP + firewall-cmd --permanent --direct --add-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $IP + else + # Needed to use rc.local with some systemd distros + if [[ "$OS" = 'debian' && ! -e $RCLOCAL ]]; then + echo '#!/bin/sh -e +exit 0' > $RCLOCAL + fi + chmod +x $RCLOCAL + # Set NAT for the VPN subnet + iptables -t nat -A POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $IP + sed -i "1 a\iptables -t nat -A POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $IP" $RCLOCAL + if iptables -L -n | grep -qE '^(REJECT|DROP)'; then + # If iptables has at least one REJECT rule, we asume this is needed. + # Not the best approach but I can't think of other and this shouldn't + # cause problems. + iptables -I INPUT -p $PROTOCOL --dport $PORT -j ACCEPT + iptables -I FORWARD -s 10.8.0.0/24 -j ACCEPT + iptables -I FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT + sed -i "1 a\iptables -I INPUT -p $PROTOCOL --dport $PORT -j ACCEPT" $RCLOCAL + sed -i "1 a\iptables -I FORWARD -s 10.8.0.0/24 -j ACCEPT" $RCLOCAL + sed -i "1 a\iptables -I FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT" $RCLOCAL + fi + fi + # If SELinux is enabled and a custom port or TCP was selected, we need this + if hash sestatus 2>/dev/null; then + if sestatus | grep "Current mode" | grep -qs "enforcing"; then + if [[ "$PORT" != '1194' || "$PROTOCOL" = 'tcp' ]]; then + # semanage isn't available in CentOS 6 by default + if ! hash semanage 2>/dev/null; then + yum install policycoreutils-python -y + fi + semanage port -a -t openvpn_port_t -p $PROTOCOL $PORT + fi + fi + fi + # And finally, restart OpenVPN + if [[ "$OS" = 'debian' ]]; then + # Little hack to check for systemd + if pgrep systemd-journal; then + systemctl restart openvpn@server.service + else + /etc/init.d/openvpn restart + fi + else + if pgrep systemd-journal; then + systemctl restart openvpn@server.service + systemctl enable openvpn@server.service + else + service openvpn restart + chkconfig openvpn on + fi + fi + # Try to detect a NATed connection and ask about it to potential LowEndSpirit users + EXTERNALIP=$(wget -4qO- "http://whatismyip.akamai.com/") + if [[ "$IP" != "$EXTERNALIP" ]]; then + echo "" + echo "Looks like your server is behind a NAT!" + echo "" + echo "If your server is NATed (e.g. LowEndSpirit), I need to know the external IP" + echo "If that's not the case, just ignore this and leave the next field blank" + read -p "External IP: " -e USEREXTERNALIP + if [[ "$USEREXTERNALIP" != "" ]]; then + IP=$USEREXTERNALIP + fi + fi + # client-common.txt is created so we have a template to add further users later + echo "client +dev tun +proto $PROTOCOL +sndbuf 0 +rcvbuf 0 +remote $IP $PORT +resolv-retry infinite +nobind +persist-key +persist-tun +remote-cert-tls server +auth SHA512 +cipher AES-256-CBC +comp-lzo +setenv opt block-outside-dns +key-direction 1 +verb 3" > /etc/openvpn/client-common.txt + # Generates the custom client.ovpn + newclient "$CLIENT" + echo "" + echo "Finished!" + echo "" + echo "Your client configuration is available at" ~/"$CLIENT.ovpn" + echo "If you want to add more clients, you simply need to run this script again!" +fi diff --git a/openvpn.sh b/openvpn.sh new file mode 100755 index 0000000..c434478 --- /dev/null +++ b/openvpn.sh @@ -0,0 +1,2 @@ +openvpn --config ~/linux.ovpn +ip route add default dev tun0