Openswan

Openswan is an IPsec implementation for Linux. It has support for most of the extensions (RFC + IETF drafts) related to IPsec, including IKEv2, X.509 Digital Certificates, NAT Traversal, and many others. Openswan was originally based on FreeS/WAN 2.04 CVS with the X.509 Patch from Andreas Steffen, the NAT-T patch from Arkoon networks and some minor bug fixes from 2.05 and 2.06. See CREDITS for the history. A recent Linux distribution based on either Kernel 2.4.x, or 2.6.x are the currently supported platforms. Most recent distributions have package support for openswan. Unless a source based build is truly needed, it is often best to use the pre-built distributions packaged version. 3. iproute2, iptables, sed, awk, bash, cut and possibly other tools are required at runtime. Debian package names: libpcap0.8-dev, libpcap0.8, electric-fence, tcpdump Rpm package names: libpcap, libpcap-devel, ElectricFence, tcpdump To use Openswan with the linux native (builtin) IPsec stack, then the following steps should be all that are needed. Please use at least kernel version 2.6.9, as prior versions of the kernel have serious bugs in the native IPsec stack. From the Openswan directory: Note: The ipsec-tools package is no longer needed. Instead iproute2 = 2.6.8 is required. For backported kernels, setkey and thus ipsec-tools might still be required. Run 'ipsec verify' to determine if your system has either one of the requirements. To use the Openswan KLIPS IPsec stack (ipsec0 devices) for Linux Kernels 2.6.23 and higher, the following steps should work. From the Openswan directory: For Linux 2.6 Kernels before 2.6.23, including 2.4 linux systems, the kernel requires patching if NAT-T support or SAref tracking is required. Full kernel source will be required as the kernel sources are being patched, built and installed. It is good practice to build and install an unpatched kernel before starting to ensure the process is correct. See your distribution documentation on how to build and install a new kernel Determine the linux source directory, for example /usr/src/linux on most full source installs. It may also be /usr/src/linux-2.[46].X Premade patches for some distributions kernels can be found in patches/kernel/ It is recommended that kernel 2.6.32 or higher is used. Documentation on SAref/MAST can be found in docs/HACKING/Mast and doc/klips/mast.xml. To understand what SAref tracking does, see doc/ipsecsaref.png and the overlapip= entry in the ipsec.conf man page. For OCF HW offloading support, you need also need a patched kernel See: for more details. The Openswan configuration file can select which ipsec stack to use at runtime by using the "protostack= " options in ipsec.conf. See the ipsec.conf man page for more information on configuration options. 2. You can 'make install' overtop of your old version - it won't replace your /etc/ipsec. config files is home to the Openswan Wiki. It has the most up to date documentation, interop guides and other related information. Commercial support for Openswan is also available - see for more information, or email [email protected] All security vulnerabilities found that require public disclosure will receive proper CVE tracking numbers (see and co-ordinated via the vendor-sec mailing list. A complete list of known security vulnerabilities is available at: Several high-level documents are in the doc directory. Most are in HTML format; See doc/index.html for the top level index. These are now considered obsolete. The bulk of this software is under the GNU General Public License; see LICENSE. Some parts of it are not; see CREDITS for the details.