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 XFRM IPsec stack.
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:
https://download.libreswan.org/
A Git repository is available at:
https://github.com/libreswan/libreswan/
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 to 5.x, as well as NetBSD and FreeBSD are supported platforms. Libreswan has been ported to Windows and OSX in the past as well. With effort, it can be compiled to run on Linux no-mmu systems as well.
Most distributions have native packaged support for Libreswan. Libreswan is available for RHEL, Fedora, CentOS, 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:
For Debian/Ubuntu
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
(unbound is build without event api, set USE_DNSSEC=false)
For Fedora/CentOS-Stream/RHEL/AlmaLinux/RockyLinux etc.
yum install audit-libs-devel bison curl-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
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
Install requirements for rpm package building:
dnf install rpm-build rpmdevtools
The packaging/ directory is used to find the proper spce file for your distribution. Simply issue the command: make rpm You can also pick a specific spec file. For example, to build for CentOS8, use: rpmbuild -ba packaging/centos/8/libreswan.spec
The packaging/debian directory is used to build deb files. Simply issue the command: make deb
make programs
sudo make install
If you want to build without creating and installing manual pages, run:
make base
sudo make install-base
Note: For Linux, 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 RHEL8, 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. This command will auto-detect the init system and invoke it:
ipsec start
ipsec stop
For a connection status overview, use: ipsec trafficstatus For a brief status overview, use: ipsec briefstatus For a machine readable global status, use: ipsec globalstatus
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:
ipsec initnss
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, Openswan 2.x or older Libreswan versions to Libreswan 4.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.
Note that for rpm based systems, the NSS directory changed from /etc/ipsec.d to /var/lib/ipsec/nss/
Mailing lists:
https://lists.libreswan.org/ is home of all our the mailing lists
Wiki:
https://libreswan.org is home to the Libreswan wiki. it contains
documentation, interop guides and other useful information.
IRC:
Libreswan developers and users can be found on IRC, on #libreswan
irc.libera.chat
Bugs can be reported on the mailing list or using our bug tracking system, at https://github.com/libreswan/libreswan/issues
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:
https://libreswan.org/security/
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.libera.chat
For those who want to track things a bit more closely, the [email protected] mailing list will mail all the commit messages when they happen. This list is quite busy during active development periods.
The most up to date documentation consists of the man pages that come with the software. Further documentation can be found at https://libreswan.org/ and the wiki at https://libreswan.org/wiki/
The KLIPS IPsec stack has been removed. Please use the XFRM stack. If you wish to have network interfaces like KLIPS had, please use the XFRMi interfaces via the ipsec-interface= keyword, or use the less capable VTI interface support.