Libreswan

Is this article helpful to you?
Please consider donating or volunteering
Thank you!

Warning:

Note that you should try and learn as much as you can about VPN, Ipsec, and Security in general before playing with this. You risk leaving your server exposed to the bad guys. Whilst the contribs do their best to make sure there is a simple secure setup, I make no guarantees ! Where possible use RSA keys instead of passwords. An alternative solution is https://wiki.contribs.org/OpenVPN_SiteToSite or https://wiki.contribs.org/OpenVPN_Bridge Where possible avoid the use of PPTP as it was cracked a long time ago and is very easy to read

Version

SME8

Centos 5:

OpenSwan

openswan

Please use the version of openswan in the ReetP repo as below

smeserver-openswan

The latest version of smeserver-openswan is available in the SME repository, click on the version number(s) for more information.

SME9

Alpha 10:

4.15-2

Contrib 9:

3.16-1

libreswan

The latest version of libreswan is available in the SME repository, click on the version number(s) for more information.

Devel 10:

0.5-36

Devel 9:

0.5-33

Contrib 9:

0.5-31

smeserver-libreswan

The latest version of smeserver-libreswan is available in the SME repository, click on the version number(s) for more information.

Openswan

Openswan is a free implementation of IPsec & IKE for Linux. IPsec is the Internet Protocol Security and uses strong cryptography to provide both authentication and encryption services. These services allow you to build secure tunnels through untrusted networks. Everything passing through the untrusted net is encrypted by the ipsec gateway machine and decrypted by the gateway at the other end of the tunnel.The resulting tunnel is a virtual private network or VPN.

Libreswan

Libreswan is a free software implementation of the most widely supported and standarized VPN protocol based on ("IPsec") and the Internet Key Exchange ("IKE"). These standards are produced and maintained by the Internet Engineering Task Force ("IETF").

Note that Libreswan will become the default ipsec installation from CentOS 6.8

https://libreswan.org/wiki/HOWTO:_openswan_to_libreswan_migration

• Credits: John Crisp
• Discuss: This How-to can be discussed on the forums here

Installation

[edit]

• For Koozali SME8
• For Koozali SME9

For Koozali SME Server 8 you will need the ReetP repo to install openswan

yum --enablerepo=smecontribs,epel,reetp install smeserver-openswan

Configuration options and notes are here (check the latest branch):

https://github.com/reetp/smeserver-openswan

For Koozali SME Server 9, Libreswan can be found in the default repo's, so to install Libreswan simply enter the following command:

yum --enablerepo=smecontribs,epel install smeserver-libreswan

Configuration options and notes are here (check the latest branch):

https://github.com/reetp/smeserver-libreswan

	Note:
	I usually have the the latest version of libreswan in my own repo https://wiki.contribs.org/User:ReetP Use at your own risk !

IPSEC server to server configuration

Openswan/IPSEC can be used to setup a secure and permanent VPN connection between a SME Server and another (local or remote) IPSEC enabled device such as a router.

Note - if you want to use with an online VPS set the server to server/gateway with a 'dummy' internal network adaptor.

Passwords

It is recommended to create a very strong random password and keep this safe. One way of generating and store a random strong password is explained here

Alternatively see RSA key section below for much stronger passwords

Settings

The contrib has a lot of configurable settings but with the defaults and few details it should just work

config setprop ipsec status enabled access public

Note for ipsec_connections we use 'set' when we create new connection. Thereafter you can modify it with setprop.

Note most people refer to East and West rather than Local and Remote. There is a very good reason for this if you start using RSA keys !

Server East - WAN IP 5.6.7.8 Local IP 192.168.20.1 Subnet 192.168.20.0/24

db ipsec_connections set MyEast ipsec status enabled leftsourceip 192.168.20.1 leftsubnet 192.168.20.0/24 right 1.2.3.4 rightsubnet 10.0.0.0/24 passwd MyPassWd

Server West- WAN IP 1.2.3.4 Local IP 10.0.0.1 Subnet 10.0.0.0/24

db ipsec_connections set MyWest ipsec status enabled leftsourceip 10.0.0.1 leftsubnet 10.0.0.0/24 right 5.6.7.8 rightsubnet 192.168.20.0/24 passwd MyPassWd

signal-event ipsec-update

Logs and Debug

The following will give you connection details.

ipsec whack --status

You should get this if the connection made : 'IPsec SA established'

The following check your configuration (may be some warnings - severity depends on what they are):

ipsec verify 

If you modify a connection use

signal-event ipsec-update

For a restart of ipsec use

service ipsec restart

You may find masq needs a restart sometimes

/etc/init.d/masq restart

Check /var/log/iptables/current to see if packets are getting blocked.

For ipsec itself place to look is /var/log/pluto/pluto.log

If you need more debugging you can set plutodebug = all

RSA Keys

For the better security it is recommended to use RSA keys. There is more on this on the github page https://github.com/reetp/smeserver-libreswan/blob/master/IpsecSettings.txt

Bug report

SME8 OpenSwan IPSEC is listed in the bugtracker contribs section. Please report all bugs, new feature requests and documentation issues there.

"No open bugs found."

SME9 LibreSwan IPSEC is listed in the bugtracker contribs section. Please report all bugs, new feature requests and documentation issues there.

ID	Product	Version	Status	Summary (4 tasks) ⇒
12109	SME Contribs	10.0	CONFIRMED	NFR reuse existing entries in manager code
11405	SME Contribs	10beta	RESOLVED	Initial Import in SME 10 [smeserver-libreswan]
10661	SME Contribs	9.2	CONFIRMED	New file to adjust redirects in /etc/sysctl.d
9305	SME Contribs	9.1	CONFIRMED	Trouble configuring kernel settings for ipsec contrib

Other articles in this category

Ipsec, Libreswan, Libreswan-xl2tpd, OpenVPN, OpenVPN Bridge, OpenVPN Bridge/fr, OpenVPN Routed, OpenVPN SiteToSite, SME Server wishlist, SoftEther VPN, Softethervpn-server, VPN, Wireguard