OpenVPN

From Blue-IT.org Wiki

Revision as of 10:35, 17 November 2015 by Apos (talk | contribs) (Prerequisites)

Introduction

After successfully played around with an Cisco ASA 5505 Firewall we liked to expand our VPN experience. I personally was a little disappointed about the solutions, Cisco offered to us. First of all, I was very disappointed finding out, that - for IPSec VPN - there doesn't exist an native 64bit client for my linux machine. Second the license fees for SSL VPN are barely legal. Third the license and configuration djungle Cisco offers is not what I like.

To make a long story short: pFsense has everything we needed, was configured in a snap and in combination with a Soekris hardware ist a really robust, fast and easy to maintain appliance. ooking back spending hours and hours configuring the ASA, dangling around with license issues and limitationsone of the software this was one of the best decisions this year!

pFSense

There are a lot of HowTo's and Tutorials how to get OpenVPN running with pfSense in version 2.x. I don't like to add another 2 cents here.

OpenVPN auto reconnect script

Despite the very stable connection overall - if you are on the road and the internet connection is lost, the network manager of Ubuntu does not reconnect when internet is available again.

I am using a little improved script.

Because I am NOT SAVING MY VPN PASSWORD in the keyring, the gui asks for the vpn passord. It does this every 30 seconds. The problem: if nobody enters the password, the gui popups a new password dialog. This results in a massive amount of dialogues open. During one night > 30-40 dialogues. This means, the dialogue is not reopend on every recall.

This does NOT work for me on Ubuntu 14.04:

Prerequisites

  1. If you are using VirtualBox, you should VirtualBox#Reconnect_on_lost_network_connection read this article about reconnection the guest network, install the script and set useVboxReconnect="yes"
  2. If you have a second (failover) VPN server, you can use this one by setting useVPNEmergency="yes" and give $myVPN_EMERGENCY a value in the configuration file.
  3. MANDATORY: Install the helper script Bash#Kill_all_processes_with_a_certain_name killall_ in /home/${USER}/bin or find another solution to kill the password dialog
  4. MANDATORY: A configuration file conf/vpn_reconnect.conf (/home/${USER}/bin/conf) with the following content:
cd /home/${USER}/bin/
mkdir conf
vim vpn_reconnect.conf
# The "pinghost" should be the host, 
# which name resolution should be working
# when the vpn is connected
# e.g. "my-firewall" should resolve the ip "10.10.1.1"
PING_HOST="hostname of vpn host"
DOMAIN="domainname.int"
myVPN="uuid from /etc/NetworkManager/system-connections"
# alternate vpn server / backup vpn
myVPN_EMERGENCY="uuid from /etc/NetworkManager/system-connections"

The script

touch /home/${USER}/bin/vpn_reconnect
chmod 755 /home/${USER}/bin/vpn_reconnect
vim /home/${USER}/bin/vpn_reconnect
#!/bin/bash
# The "pinghost" should be the host, 
# which name resolution should be working
# when the vpn is connected
# e.g. "my-firewall" should resolve the ip "10.10.1.1"

# PRE: You should keep the openvpn-auth-dialog in foreground 
# - using e. g. CCSM
# - Window rules
# - Above:  | class=Nm-openvpn-auth-dialog
# - Sticky: | class=Nm-openvpn-auth-dialog
## SET ACCORDING TO USAGE ############################
useVPNEmergency="no"
useVboxReconnect="no"
######################################################
 
PING_HOST=""
DOMAIN=""
myVPN=""
myVPN_EMERGENCY=""
myGSM=""
cd /home/${USER}/bin
source conf/vpn_reconnect.conf

export PATH="${PATH}:/home/${USER}/bin"

export LC_MESSAGES="en_US.UTF-8"
export LC_TYPE="en_US.UTF-8"
export LANGUAGE="en_US.UTF-8"

vpn_connect() {

    echo "Killing all opened openvpn auth dialog"
    if [ "$(ps x | grep openvpn-auth-dialog | grep -v grep | awk '{print $1}')" == "" ]
    then
        echo "No openvpn-auth-dialog open ... continuing"
    else
        killall_ openvpn-auth-dialog
        if ["$useVPNEmergency" == "yes"]; then vbox_reconnect_network; fi
    fi

    echo "Verbinung VPN-acinus herstellen ..."    
    if nmcli con up uuid "${myVPN}"
	then
       if ["$useVPNEmergency" == "yes"]; then vbox_reconnect_network; fi
	else
        if ["$useVPNEmergency" == "yes"]; then nmcli con up uuid "${myVPN_EMERGENCY}"; fi
        killall_ openvpn-auth-dialog
        if ["$useVPNEmergency" == "yes"]; then vbox_reconnect_network; fi
	fi
}

vpn_disconnect() {
        echo "Verbinung VPN-acinus abbauen ..."
        nmcli con down uuid "${myVPN}" || \
        nmcli con down uuid "${myVPN_EMERGENCY}"
        if ["$useVPNEmergency" == "yes"]; then vbox_reconnect_network; fi
}


# Singleton ;-)
if ps x | grep -v grep | grep -v $$ | grep $0 | grep -v subl | grep -v vi
then
        echo "$0 already running. Exiting"
        exit 1
else


        while (true);
        do

                if ping -c 5 ${PING_HOST} | grep ${DOMAIN}
                then
                        echo "Connection established (or local network)."
                else
                        echo " Recheck after 10 sec ..."
                        sleep 10

                        if ping -c 5 ${PING_HOST} | grep ${DOMAIN}
                        then
                                echo "Connection established (or local network)."
                        else
                                vpn_connect

                        fi

                fi

        sleep 30

        done

fi

VPN client on ubuntu server

Client mode

All you need is:

  • a ".ovpn" configuration file and rename it to ".conf"
    • each unique named ".conf" is a vpn client
    • chmod 600 (rw only for root)
  • all necessary credentials that refer to ".p12", ".crt", ".key" -files within the ".ovpn"-file
    • have to be in the /etc/openvpn directory and
    • chmod 400 (read only for root!)
  • place everything in the /etc/openvpn directory
  • edit the /etc/default/openvpn configuration file.
    • Put the name of the ".conf"-file without the ".conf" in the AUTOSTART variable.
    • OR simply make AUTOSTART="all" which will start all vpn clients