Miscellaneous improvements

This commit contains lots changes which are not very significant on its own but
provide important usability improvements and future proofing.

It also includes changes which required OpenVPN v2.4+ and were pending until
that version became widely available.

- General cleanup
- Improved IP address and NAT configuration
- Added input validation and sanitization
- Fix #603
- Remove "sndbuf" and "recvbuf" parameters
- Add server-side "explicit-exit-notify"
- Switch from "setenv opt" to "ignore-unknown-option"
- Switch from "tls-auth" to "tls-crypt"
- Other minor bugfixes and optimizations
This commit is contained in:
Nyr 2019-09-26 19:13:33 +02:00
parent 68e48d21b6
commit 6a29a6babd

View File

@ -5,22 +5,22 @@
# Copyright (c) 2013 Nyr. Released under the MIT License.
if grep -qs "14.04" "/etc/os-release"; then
if grep -qs "14.04" /etc/os-release; then
echo "Ubuntu 14.04 is too old and not supported"
exit
fi
if grep -qs "jessie" "/etc/os-release"; then
if grep -qs "jessie" /etc/os-release; then
echo "Debian 8 is too old and not supported"
exit
fi
if grep -qs "CentOS release 6" "/etc/redhat-release"; then
if grep -qs "CentOS release 6" /etc/redhat-release; then
echo "CentOS 6 is too old and not supported"
exit
fi
if grep -qs "Ubuntu 16.04" "/etc/os-release"; then
if grep -qs "Ubuntu 16.04" /etc/os-release; then
echo 'Ubuntu 16.04 is no longer supported in the current version of openvpn-install
Use an older version if Ubuntu 16.04 support is needed: https://git.io/vpn1604'
exit
@ -44,31 +44,33 @@ You need to enable TUN before running this script"
fi
if [[ -e /etc/debian_version ]]; then
OS=debian
GROUPNAME=nogroup
os="debian"
group_name="nogroup"
elif [[ -e /etc/centos-release || -e /etc/redhat-release ]]; then
OS=centos
GROUPNAME=nobody
os="centos"
group_name="nobody"
else
echo "Looks like you aren't running this installer on Debian, Ubuntu or CentOS"
exit
fi
newclient () {
new_client () {
# Generates the custom client.ovpn
cp /etc/openvpn/server/client-common.txt ~/$1.ovpn
echo "<ca>" >> ~/$1.ovpn
cat /etc/openvpn/server/easy-rsa/pki/ca.crt >> ~/$1.ovpn
echo "</ca>" >> ~/$1.ovpn
echo "<cert>" >> ~/$1.ovpn
sed -ne '/BEGIN CERTIFICATE/,$ p' /etc/openvpn/server/easy-rsa/pki/issued/$1.crt >> ~/$1.ovpn
echo "</cert>" >> ~/$1.ovpn
echo "<key>" >> ~/$1.ovpn
cat /etc/openvpn/server/easy-rsa/pki/private/$1.key >> ~/$1.ovpn
echo "</key>" >> ~/$1.ovpn
echo "<tls-auth>" >> ~/$1.ovpn
sed -ne '/BEGIN OpenVPN Static key/,$ p' /etc/openvpn/server/ta.key >> ~/$1.ovpn
echo "</tls-auth>" >> ~/$1.ovpn
{
cat /etc/openvpn/server/client-common.txt
echo "<ca>"
cat /etc/openvpn/server/easy-rsa/pki/ca.crt
echo "</ca>"
echo "<cert>"
sed -ne '/BEGIN CERTIFICATE/,$ p' /etc/openvpn/server/easy-rsa/pki/issued/"$1".crt
echo "</cert>"
echo "<key>"
cat /etc/openvpn/server/easy-rsa/pki/private/"$1".key
echo "</key>"
echo "<tls-crypt>"
sed -ne '/BEGIN OpenVPN Static key/,$ p' /etc/openvpn/server/tc.key
echo "</tls-crypt>"
} > ~/"$1".ovpn
}
if [[ -e /etc/openvpn/server/server.conf ]]; then
@ -82,26 +84,35 @@ if [[ -e /etc/openvpn/server/server.conf ]]; then
echo " 2) Revoke an existing user"
echo " 3) Remove OpenVPN"
echo " 4) Exit"
read -p "Select an option [1-4]: " option
case $option in
read -p "Select an option: " option
until [[ "$option" =~ ^[1-4]$ ]]; do
echo "$option: invalid selection."
read -p "Select an option: " option
done
case "$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 CLIENT
read -p "Client name: " unsanitized_client
client=$(sed 's/[^0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-]/_/g' <<< "$unsanitized_client")
while [[ -z "$client" || -e /etc/openvpn/server/easy-rsa/pki/issued/"$client".crt ]]; do
echo "$client: invalid client name."
read -p "Client name: " unsanitized_client
client=$(sed 's/[^0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-]/_/g' <<< "$unsanitized_client")
done
cd /etc/openvpn/server/easy-rsa/
EASYRSA_CERT_EXPIRE=3650 ./easyrsa build-client-full $CLIENT nopass
EASYRSA_CERT_EXPIRE=3650 ./easyrsa build-client-full "$client" nopass
# Generates the custom client.ovpn
newclient "$CLIENT"
new_client "$client"
echo
echo "Client $CLIENT added, configuration is available at:" ~/"$CLIENT.ovpn"
echo "Client $client added, configuration is available at:" ~/"$client.ovpn"
exit
;;
2)
# This option could be documented a bit better and maybe even be simplified
# ...but what can I say, I want some sleep too
NUMBEROFCLIENTS=$(tail -n +2 /etc/openvpn/server/easy-rsa/pki/index.txt | grep -c "^V")
if [[ "$NUMBEROFCLIENTS" = '0' ]]; then
number_of_clients=$(tail -n +2 /etc/openvpn/server/easy-rsa/pki/index.txt | grep -c "^V")
if [[ "$number_of_clients" = 0 ]]; then
echo
echo "You have no existing clients!"
exit
@ -109,60 +120,68 @@ if [[ -e /etc/openvpn/server/server.conf ]]; then
echo
echo "Select the existing client certificate you want to revoke:"
tail -n +2 /etc/openvpn/server/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=$(tail -n +2 /etc/openvpn/server/easy-rsa/pki/index.txt | grep "^V" | cut -d '=' -f 2 | sed -n "$CLIENTNUMBER"p)
read -p "Select one client: " client_number
until [[ "$client_number" =~ ^[0-9]+$ && "$client_number" -le "$number_of_clients" ]]; do
echo "$client_number: invalid selection."
read -p "Select one client: " client_number
done
client=$(tail -n +2 /etc/openvpn/server/easy-rsa/pki/index.txt | grep "^V" | cut -d '=' -f 2 | sed -n "$client_number"p)
echo
read -p "Do you really want to revoke access for client $CLIENT? [y/N]: " -e REVOKE
if [[ "$REVOKE" = 'y' || "$REVOKE" = 'Y' ]]; then
read -p "Do you really want to revoke access for client $client? [y/N]: " revoke
until [[ "$revoke" =~ ^[yYnN]*$ ]]; do
echo "$revoke: invalid selection."
read -p "Do you really want to revoke access for client $client? [y/N]: " revoke
done
if [[ "$revoke" =~ ^[yY]$ ]]; then
cd /etc/openvpn/server/easy-rsa/
./easyrsa --batch revoke $CLIENT
./easyrsa --batch revoke "$client"
EASYRSA_CRL_DAYS=3650 ./easyrsa gen-crl
rm -f pki/reqs/$CLIENT.req
rm -f pki/private/$CLIENT.key
rm -f pki/issued/$CLIENT.crt
rm -f pki/reqs/"$client".req
rm -f pki/private/"$client".key
rm -f pki/issued/"$client".crt
rm -f /etc/openvpn/server/crl.pem
cp /etc/openvpn/server/easy-rsa/pki/crl.pem /etc/openvpn/server/crl.pem
# CRL is read with each client connection, when OpenVPN is dropped to nobody
chown nobody:$GROUPNAME /etc/openvpn/server/crl.pem
chown nobody:"$group_name" /etc/openvpn/server/crl.pem
echo
echo "Certificate for client $CLIENT revoked!"
echo "Certificate for client $client revoked!"
else
echo
echo "Certificate revocation for client $CLIENT aborted!"
echo "Certificate revocation for client $client aborted!"
fi
exit
;;
3)
echo
read -p "Do you really want to remove OpenVPN? [y/N]: " -e REMOVE
if [[ "$REMOVE" = 'y' || "$REMOVE" = 'Y' ]]; then
PORT=$(grep '^port ' /etc/openvpn/server/server.conf | cut -d " " -f 2)
PROTOCOL=$(grep '^proto ' /etc/openvpn/server/server.conf | cut -d " " -f 2)
read -p "Do you really want to remove OpenVPN? [y/N]: " remove
until [[ "$remove" =~ ^[yYnN]*$ ]]; do
echo "$remove: invalid selection."
read -p "Do you really want to remove OpenVPN? [y/N]: " remove
done
if [[ "$remove" =~ ^[yY]$ ]]; then
port=$(grep '^port ' /etc/openvpn/server/server.conf | cut -d " " -f 2)
protocol=$(grep '^proto ' /etc/openvpn/server/server.conf | cut -d " " -f 2)
if pgrep firewalld; then
IP=$(firewall-cmd --direct --get-rules ipv4 nat POSTROUTING | grep '\-s 10.8.0.0/24 '"'"'!'"'"' -d 10.8.0.0/24 -j SNAT --to ' | cut -d " " -f 10)
ip=$(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 --remove-port=$PORT/$PROTOCOL
firewall-cmd --remove-port="$port"/"$protocol"
firewall-cmd --zone=trusted --remove-source=10.8.0.0/24
firewall-cmd --permanent --remove-port=$PORT/$PROTOCOL
firewall-cmd --permanent --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 $IP
firewall-cmd --direct --remove-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to "$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 "$ip"
else
systemctl disable --now openvpn-iptables.service
rm -f /etc/systemd/system/openvpn-iptables.service
fi
if sestatus 2>/dev/null | grep "Current mode" | grep -q "enforcing" && [[ "$PORT" != '1194' ]]; then
semanage port -d -t openvpn_port_t -p $PROTOCOL $PORT
if sestatus 2>/dev/null | grep "Current mode" | grep -q "enforcing" && [[ "$port" != 1194 ]]; then
semanage port -d -t openvpn_port_t -p "$protocol" "$port"
fi
systemctl disable --now openvpn-server@server.service
rm -rf /etc/openvpn/server
rm -f /etc/systemd/system/openvpn-server@server.service.d/disable-limitnproc.conf
rm -f /etc/sysctl.d/30-openvpn-forward.conf
if [[ "$OS" = 'debian' ]]; then
if [[ "$os" = "debian" ]]; then
apt-get remove --purge -y openvpn
else
yum remove openvpn -y
@ -180,39 +199,59 @@ if [[ -e /etc/openvpn/server/server.conf ]]; then
done
else
clear
echo 'Welcome to this OpenVPN "road warrior" installer!'
echo "Welcome to this 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, provide the IPv4 address of the network interface you want OpenVPN"
echo "listening to."
# Autodetect IP 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)
read -p "IP address: " -e -i $IP IP
echo "I need to ask you a few questions before starting setup."
echo "You can use the default options and just press enter if you are ok with them."
# If system has a single IPv4, it is selected automatically. Else, ask the user
if [[ $(ip addr | grep inet | grep -v inet6 | grep -vEc '127\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}') -eq 1 ]]; then
ip=$(ip addr | grep inet | grep -v inet6 | grep -vE '127\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}')
else
number_of_ips=$(ip addr | grep inet | grep -v inet6 | grep -vEc '127\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}')
echo
echo "What IPv4 address should the OpenVPN server bind to?"
ip addr | grep inet | grep -v inet6 | grep -vE '127\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | nl -s ') '
read -p "IPv4 address [1]: " ip_number
until [[ -z "$ip_number" || "$ip_number" =~ ^[0-9]+$ && "$ip_number" -le "$number_of_ips" ]]; do
echo "$ip_number: invalid selection."
read -p "IPv4 address [1]: " ip_number
done
[[ -z "$ip_number" ]] && ip_number="1"
ip=$(ip addr | grep inet | grep -v inet6 | grep -vE '127\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | cut -d '/' -f 1 | grep -oE '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | sed -n "$ip_number"p)
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
if echo "$ip" | grep -qE '^(10\.|172\.1[6789]\.|172\.2[0-9]\.|172\.3[01]\.|192\.168)'; then
echo
echo "This server is behind NAT. What is the public IPv4 address or hostname?"
read -p "Public IP address / hostname: " -e PUBLICIP
get_public_ip=$(wget -4qO- "http://whatismyip.akamai.com/" || curl -4Ls "http://whatismyip.akamai.com/")
read -p "Public IPv4 address / hostname [$get_public_ip]: " public_ip
[ -z "$public_ip" ] && public_ip="$get_public_ip"
fi
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 $PROTOCOL in
1)
PROTOCOL=udp
read -p "Protocol [1]: " protocol
until [[ -z "$protocol" || "$protocol" =~ ^[12]$ ]]; do
echo "$protocol: invalid selection."
read -p "Protocol [1]: " protocol
done
case "$protocol" in
1|"")
protocol=udp
;;
2)
PROTOCOL=tcp
protocol=tcp
;;
esac
echo
echo "What port do you want OpenVPN listening to?"
read -p "Port: " -e -i 1194 PORT
read -p "Port [1194]: " port
until [[ -z "$port" || "$port" =~ ^[0-9]+$ && "$port" -le 65535 ]]; do
echo "$port: invalid selection."
read -p "Port [1194]: " port
done
[[ -z "$port" ]] && port="1194"
echo
echo "Which DNS do you want to use with the VPN?"
echo " 1) Current system resolvers"
@ -220,21 +259,27 @@ else
echo " 3) Google"
echo " 4) OpenDNS"
echo " 5) Verisign"
read -p "DNS [1-5]: " -e -i 1 DNS
read -p "DNS [1]: " dns
until [[ -z "$dns" || "$dns" =~ ^[1-5]$ ]]; do
echo "$dns: invalid selection."
read -p "DNS [1]: " dns
done
echo
echo "Finally, tell me your name for the client certificate."
echo "Please, use one word only, no special characters."
read -p "Client name: " -e -i client CLIENT
echo "Finally, tell me a name for the client certificate."
read -p "Client name [client]: " unsanitized_client
# Allow a limited set of characters to avoid conflicts
client=$(sed 's/[^0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_-]/_/g' <<< "$unsanitized_client")
[[ -z "$client" ]] && client="client"
echo
echo "Okay, that was all I needed. We are ready to set up your OpenVPN server now."
read -n1 -r -p "Press any key to continue..."
# If running inside a container, disable LimitNPROC to prevent conflicts
if systemd-detect-virt -cq; then
mkdir /etc/systemd/system/openvpn-server@server.service.d/ 2>/dev/null
echo '[Service]
LimitNPROC=infinity' > /etc/systemd/system/openvpn-server@server.service.d/disable-limitnproc.conf
echo "[Service]
LimitNPROC=infinity" > /etc/systemd/system/openvpn-server@server.service.d/disable-limitnproc.conf
fi
if [[ "$OS" = 'debian' ]]; then
if [[ "$os" = "debian" ]]; then
apt-get update
apt-get install openvpn iptables openssl ca-certificates -y
else
@ -243,8 +288,8 @@ LimitNPROC=infinity' > /etc/systemd/system/openvpn-server@server.service.d/disab
yum install openvpn iptables openssl ca-certificates -y
fi
# Get easy-rsa
EASYRSAURL='https://github.com/OpenVPN/easy-rsa/releases/download/v3.0.5/EasyRSA-nix-3.0.5.tgz'
wget -O ~/easyrsa.tgz "$EASYRSAURL" 2>/dev/null || curl -Lo ~/easyrsa.tgz "$EASYRSAURL"
easy_rsa_url='https://github.com/OpenVPN/easy-rsa/releases/download/v3.0.5/EasyRSA-nix-3.0.5.tgz'
wget -O ~/easyrsa.tgz "$easy_rsa_url" 2>/dev/null || curl -Lo ~/easyrsa.tgz "$easy_rsa_url"
tar xzf ~/easyrsa.tgz -C ~/
mv ~/EasyRSA-3.0.5/ /etc/openvpn/server/
mv /etc/openvpn/server/EasyRSA-3.0.5/ /etc/openvpn/server/easy-rsa/
@ -255,14 +300,14 @@ LimitNPROC=infinity' > /etc/systemd/system/openvpn-server@server.service.d/disab
./easyrsa init-pki
./easyrsa --batch build-ca nopass
EASYRSA_CERT_EXPIRE=3650 ./easyrsa build-server-full server nopass
EASYRSA_CERT_EXPIRE=3650 ./easyrsa build-client-full $CLIENT nopass
EASYRSA_CERT_EXPIRE=3650 ./easyrsa build-client-full "$client" nopass
EASYRSA_CRL_DAYS=3650 ./easyrsa gen-crl
# Move the stuff we need
cp pki/ca.crt pki/private/ca.key pki/issued/server.crt pki/private/server.key pki/crl.pem /etc/openvpn/server
# CRL is read with each client connection, when OpenVPN is dropped to nobody
chown nobody:$GROUPNAME /etc/openvpn/server/crl.pem
# Generate key for tls-auth
openvpn --genkey --secret /etc/openvpn/server/ta.key
chown nobody:"$group_name" /etc/openvpn/server/crl.pem
# Generate key for tls-crypt
openvpn --genkey --secret /etc/openvpn/server/tc.key
# Create the DH parameters file using the predefined ffdhe2048 group
echo '-----BEGIN DH PARAMETERS-----
MIIBCAKCAQEA//////////+t+FRYortKmq/cViAnPTzx2LnFg84tNpWp4TZBFGQz
@ -273,33 +318,32 @@ YdEIqUuyyOP7uWrat2DX9GgdT0Kj3jlN9K5W7edjcrsZCwenyO4KbXCeAvzhzffi
ssbzSibBsu/6iGtCOGEoXJf//////////wIBAg==
-----END DH PARAMETERS-----' > /etc/openvpn/server/dh.pem
# Generate server.conf
echo "port $PORT
proto $PROTOCOL
echo "local $ip
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
tls-crypt tc.key
topology subnet
server 10.8.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt" > /etc/openvpn/server/server.conf
echo 'push "redirect-gateway def1 bypass-dhcp"' >> /etc/openvpn/server/server.conf
# DNS
case $DNS in
1)
case "$dns" in
1|"")
# 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'
resolv_conf="/run/systemd/resolve/resolv.conf"
else
RESOLVCONF='/etc/resolv.conf'
resolv_conf="/etc/resolv.conf"
fi
# Obtain the resolvers from resolv.conf and use them for OpenVPN
grep -v '#' $RESOLVCONF | grep 'nameserver' | grep -E -o '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}' | while read line; do
grep -v '#' "$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/server.conf
done
;;
@ -323,12 +367,15 @@ ifconfig-pool-persist ipp.txt" > /etc/openvpn/server/server.conf
echo "keepalive 10 120
cipher AES-256-CBC
user nobody
group $GROUPNAME
group $group_name
persist-key
persist-tun
status openvpn-status.log
verb 3
crl-verify crl.pem" >> /etc/openvpn/server/server.conf
if [[ "$protocol" = "udp" ]]; then
echo "explicit-exit-notify" >> /etc/openvpn/server/server.conf
fi
# Enable net.ipv4.ip_forward for the system
echo 'net.ipv4.ip_forward=1' > /etc/sysctl.d/30-openvpn-forward.conf
# Enable without waiting for a reboot or service restart
@ -338,25 +385,25 @@ crl-verify crl.pem" >> /etc/openvpn/server/server.conf
# reload.
# We don't use --add-service=openvpn because that would only work with
# the default port and protocol.
firewall-cmd --add-port=$PORT/$PROTOCOL
firewall-cmd --add-port="$port"/"$protocol"
firewall-cmd --zone=trusted --add-source=10.8.0.0/24
firewall-cmd --permanent --add-port=$PORT/$PROTOCOL
firewall-cmd --permanent --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 $IP
firewall-cmd --direct --add-rule ipv4 nat POSTROUTING 0 -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to "$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
# Create a service to set up persistent iptables rules
echo "[Unit]
Before=network.target
[Service]
Type=oneshot
ExecStart=/sbin/iptables -t nat -A POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $IP
ExecStart=/sbin/iptables -I INPUT -p $PROTOCOL --dport $PORT -j ACCEPT
ExecStart=/sbin/iptables -t nat -A POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $ip
ExecStart=/sbin/iptables -I INPUT -p $protocol --dport $port -j ACCEPT
ExecStart=/sbin/iptables -I FORWARD -s 10.8.0.0/24 -j ACCEPT
ExecStart=/sbin/iptables -I FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
ExecStop=/sbin/iptables -t nat -D POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $IP
ExecStop=/sbin/iptables -D INPUT -p $PROTOCOL --dport $PORT -j ACCEPT
ExecStop=/sbin/iptables -t nat -D POSTROUTING -s 10.8.0.0/24 ! -d 10.8.0.0/24 -j SNAT --to $ip
ExecStop=/sbin/iptables -D INPUT -p $protocol --dport $port -j ACCEPT
ExecStop=/sbin/iptables -D FORWARD -s 10.8.0.0/24 -j ACCEPT
ExecStop=/sbin/iptables -D FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
RemainAfterExit=yes
@ -365,7 +412,7 @@ WantedBy=multi-user.target" > /etc/systemd/system/openvpn-iptables.service
systemctl enable --now openvpn-iptables.service
fi
# If SELinux is enabled and a custom port was selected, we need this
if sestatus 2>/dev/null | grep "Current mode" | grep -q "enforcing" && [[ "$PORT" != '1194' ]]; then
if sestatus 2>/dev/null | grep "Current mode" | grep -q "enforcing" && [[ "$port" != 1194 ]]; then
# Install semanage if not already present
if ! hash semanage 2>/dev/null; then
if grep -qs "CentOS Linux release 7" "/etc/centos-release"; then
@ -374,21 +421,17 @@ WantedBy=multi-user.target" > /etc/systemd/system/openvpn-iptables.service
yum install policycoreutils-python-utils -y
fi
fi
semanage port -a -t openvpn_port_t -p $PROTOCOL $PORT
semanage port -a -t openvpn_port_t -p "$protocol" "$port"
fi
# And finally, enable and start the OpenVPN service
systemctl enable --now openvpn-server@server.service
# If the server is behind a NAT, use the correct IP address
if [[ "$PUBLICIP" != "" ]]; then
IP=$PUBLICIP
if [[ "$public_ip" != "" ]]; then
ip="$public_ip"
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
proto $protocol
remote $ip $port
resolv-retry infinite
nobind
persist-key
@ -396,14 +439,16 @@ persist-tun
remote-cert-tls server
auth SHA512
cipher AES-256-CBC
setenv opt block-outside-dns
key-direction 1
ignore-unknown-option block-outside-dns
block-outside-dns
verb 3" > /etc/openvpn/server/client-common.txt
# Enable and start the OpenVPN service
systemctl enable --now openvpn-server@server.service
# Generates the custom client.ovpn
newclient "$CLIENT"
new_client "$client"
echo
echo "Finished!"
echo
echo "Your client configuration is available at:" ~/"$CLIENT.ovpn"
echo "If you want to add more clients, you simply need to run this script again!"
echo "Your client configuration is available at:" ~/"$client.ovpn"
echo "If you want to add more clients, just run this script again!"
fi