#!/bin/bash
# Make sure script is ran as root
if [[ $EUID -ne 0 ]]; then
	exec sudo /bin/bash "$0" "$@"
fi

DIR=$(pwd)
for i in {1..255}; do
	CLIENT_NAME="client$i"
	if [ ! -f "/etc/openvpn/easy-rsa/pki/issued/$CLIENT_NAME.crt" ]; then
		break
	fi
done
VPN_SUBNET=$(grep -E '^server ' "/etc/openvpn/myserver.conf" | awk '{print $2}')
VPN_PUBLIC_HOST=$(grep -E '^#public-host ' "/etc/openvpn/myserver.conf" | awk '{print $2}')
VPN_PUBLIC_PORT=$(grep -E '^port ' "/etc/openvpn/myserver.conf" | awk '{print $2}')
echo "Adding VPN client to $VPN_PUBLIC_HOST:$VPN_PUBLIC_PORT"
read -e -p "Enter client name: " -i "$CLIENT_NAME" CLIENT_NAME
if [ -f "/etc/openvpn/easy-rsa/pki/issued/$CLIENT_NAME.crt" ]; then
	echo Client $CLIENT_NAME already exists...
	exit 1
fi
if grep -q "^auth-user-pass-verify" "/etc/openvpn/myserver.conf"; then
	read -e -p "Enter username: " -i "$CLIENT_NAME" CLIENT_USERNAME
	if grep -i -q "^$CLIENT_USERNAME" "/etc/openvpn/credentials"; then
		echo "Username $CLIENT_USERNAME already exists"
		exit 1
	fi
	read -e -p "Enter password: " -i "$CLIENT_PASSWORD" CLIENT_PASSWORD
	CLIENT_PASSWORD_HASH=$(echo -n "$CLIENT_PASSWORD" | sha256sum | awk '{print $1}')
	echo "$CLIENT_USERNAME:$CLIENT_PASSWORD_HASH:$CLIENT_NAME" >> "/etc/openvpn/credentials"
	EXTRA_CONFIG="auth-user-pass"
fi
read -e -p "Use static IP for this client? VPN subnet is $VPN_SUBNET (Leave empty for dynamic): " -i "" CLIENT_IP
if [ ! -z "${CLIENT_IP}" ]; then
	echo Setting IP...
cat > "/etc/openvpn/ccd/$CLIENT_NAME" <<EOL
ifconfig-push $CLIENT_IP 255.255.255.0
EOL
fi

cd /etc/openvpn/easy-rsa
./easyrsa gen-req $CLIENT_NAME nopass
./easyrsa sign-req client $CLIENT_NAME

CA_CERT=$(cat "/etc/openvpn/ca.crt")
CLIENT_CERT=$(cat "/etc/openvpn/easy-rsa/pki/issued/$CLIENT_NAME.crt")
CLIENT_KEY=$(cat "/etc/openvpn/easy-rsa/pki/private/$CLIENT_NAME.key")
TA_KEY=$(cat "/etc/openvpn/ta.key")

cd "$DIR"
cat > $CLIENT_NAME.conf <<EOL
dev tun
persist-tun
persist-key
cipher AES-256-CBC
ncp-ciphers AES-256-GCM:AES-128-GCM
auth SHA1
tls-client
client
resolv-retry infinite
remote $VPN_PUBLIC_HOST $VPN_PUBLIC_PORT udp
remote-cert-tls server
float
verb 3
$EXTRA_CONFIG

<ca>
$CA_CERT
</ca>
<cert>
$CLIENT_CERT
</cert>
<key>
$CLIENT_KEY
</key>
key-direction 1
<tls-auth>
$TA_KEY
</tls-auth>
EOL