The Libreswan Project https://libreswan.org/
Libreswan is an Internet Key Exchange (IKE) implementation for Linux. It supports IKEv1 and IKEv2 and has support for most of the extensions (RFC + IETF drafts) related to IPsec, including IKEv2, X.509 Digital Certificates, NAT Traversal, and many others. Libreswan uses the native Linux IPsec stack (NETKEY/XFRM) per default.
Libreswan was forked from Openswan 2.6.38, which was forked from FreeS/WAN 2.04. See the CREDITS files for contributor acknowledgments.
It can be downloaded from:
A Git repository is available at:
The bulk of libreswan is licensed under the GNU General Public License version 2; see the LICENSE and CREDIT.* files. Some smaller parts have a different license.
Recent Linux distributions based on kernel 2.x, 3.x or 4.x are supported platforms. Libreswan has been ported to Win2k/BSD/OSX in the past as well.
Most distributions have native packaged support for Libreswan. Libreswan is available for RHEL, Fedora, Ubuntu, Debian, Arch, OpenWrt and more.
Unless a source-based build is truly needed, it is often best to use the pre-built version of the distribution you are using.
There are a few packages required for Libreswan to compile from source:
apt-get install libnss3-dev libnspr4-dev pkg-config libpam-dev \ libcap-ng-dev libcap-ng-utils libselinux-dev \ libcurl3-nss-dev flex bison gcc make libldns-dev \ libunbound-dev libnss3-tools libevent-dev xmlto \ libsystemd-dev (there is no fipscheck library for these, set USE_FIPSCHECK=false) (unbound is build without event api, set USE_DNSSEC=false)
yum install audit-libs-devel bison curl-devel fipscheck-devel flex \ gcc ldns-devel libcap-ng-devel libevent-devel \ libseccomp-devel libselinux-devel make nspr-devel nss-devel \ pam-devel pkgconfig systemd-devel unbound-devel xmlto (on rhel/centos unbound is too old, set USE_DNSSEC=false)
yum install audit-libs-devel bison curl-devel fipscheck-devel flex \ gcc libcap-ng-devel libevent2-devel libseccomp-devel \ libselinux-devel make nspr-devel nss-devel pam-devel \ pkgconfig systemd-devel xmlto (unbound is too old to build dnssec support, set USE_DNSSEC=false)
Runtime requirements (usually already present on the system)
nss, iproute2, iptables, sed, awk, bash, cut, procps-ng, which (note: the Busybox version of "ip" does not support 'ip xfrm', so ensure you enable the iproute(2) package for busybox) Python is used for "ipsec verify", which helps debugging problems python-ipaddress is used for "ipsec show", which shows tunnels
Compiling the userland and IKE daemon
make programs sudo make install
If you want to build without creating and installing manual pages, run:
make base sudo make install-base
Note: The ipsec-tools package or setkey is not needed. Instead the iproute2
packakge (>= 2.6.8) is required. Run
ipsec verify to determine if your
system misses any of the requirements. This will also tell you if any of
the kernel sysctl values needs changing.
The install will detect the init system used (systemd, upstart, sysvinit, openrc) and should integrate with the linux distribution. The service name is called "ipsec". For example, on RHEL7, one would use:
systemctl enable ipsec.service systemctl start ipsec.service
If unsure of the specific init system used on the system, the "ipsec" command can also be used to start or stop the ipsec service:
ipsec start ipsec stop
Most of the libreswan configuration is stored in /etc/ipsec.conf and /etc/ipsec.secrets. Include files may be present in /etc/ipsec.d/ See the respective man pages for more information.
Libreswan uses NSS to store private keys and X.509 certificates. The NSS database should have been initialised by the package installer. If not, the NSS database can be initialised using:
PKCS#12 certificates (.p12 files) can be imported using:
ipsec import /path/to/your.p12
See README.NSS and
certutil --help for more details on using NSS and
migrating from the old Openswan
/etc/ipsec.d/ directories to using NSS.
If you are upgrading from FreeS/WAN 1.x or Openswan 2.x to Libreswan 3.x, you might need to adjust your config files, although great care has been put into making the configuration files full backwards compatible. See also: https://libreswan.org/wiki/HOWTO:_openswan_to_libreswan_migration
See 'man ipsec.conf' for the list of options to find any new features.
You can run
make install on top of your old version - it will not
overwrite your your
/etc/ipsec.* configuration files. The default install
target installs in
/usr/local. Ensure you do not install libreswan twice,
one from a distribution package in /usr and once manually in /usr/local.
https://lists.libreswan.org/ is home of all our the mailing lists
https://libreswan.org is home to the Libreswan wiki. it contains documentation, interop guides and other useful information.
Libreswan developers and users can be found on IRC, on #swan irc.freenode.net.
Bugs can be reported on the mailing list or using our bug tracking system, at https://bugs.libreswan.org/
All security issues found that require public disclosure will receive proper CVE tracking numbers (see https://www.mitre.org/) and will be co-ordinated via the vendor-sec / oss-security lists. A complete list of known security vulnerabilities is available at:
Those interested in the development, patches, and beta releases of Libreswan can join the development mailing list "swan-dev" or talk to the development team on IRC in #swan on irc.freenode.net
For those who want to track things a bit more closely, the email@example.com mailing list will mail all the commit messages when they happen. This list is quite busy during active development periods.
KLIPS IPsec stack
The KLIPS IPsec stack is no longer actively maintained or supported. Please migreate to using the Linux native netlink/XFRM stack. If you wish to have network interfaces like KLIPS has, please use the XFRMi (VTI) interfaces.