The main project web site is www.freeswan.org.
Links to other project-related sites are provided in
our introduction section.
Some user-contributed patches gave been integrated into the FreeS/WAN
distribution. For a variety of reasons, those listed below have not.
Patches believed current at time of writing (March 2001, just before 1.9 release):
Before using these, check the mailing list for news of newer
versions and to see whether they have been incorporated into more recent
versions of FreeS/WAN.
Note: At one point the way PGP generates RSA keys and the way
FreeS/WAN checks them for validity before using them were slightly different, so
quite a few PGP-generated keys would be rejected by FreeS/WAN, confusing users
no end. This is fixed in 1.9.
A set of PKIX patches were recently announced on the mailing list:
Subject: a different PKIX patch.
Date: Mon, 5 Mar 2001
From: Luc Lanthier <firesoul@netwinder.org>
I'd like to invite volunteers to use the now-complete PKIX project I've
been working on since about August. Because of this, the patch is for
FreeSWAN 1.5, not 1.8... I haven't really felt the need to update it since
I don't use IPV6 nor DNSSec.
This is similar, but different than Andreas Steffen's pkix
implementation. I've based this work on Neil Dunbar's openssl-pkix patch
for FreeSWAN 1.1. I've updated it to run on FreeSWAN 1.5 correctly, and
added support for ID_DER_ASN1_DN ID packet support. It will do LDAP
certificate lookups no problem, as well as local flatfile, directory, or
DB lookup for testing or speed.
IE: It's a full CA-compatible client, capable of looking up, checking the
CRL for expiry and such. It will not only do the classic PSK and RSASIG
freeswan methods just fine, but also does PKIX's RSASIG, PKE and
RPKE. I've spent a lot of time adding RoadWarrior support for these last
IKE exchange methods.
The patch can be found as:
ftp://ftp.netwinder.org/users/f/firesoul/freeswan-1.5-pkix_13.patch
There are also freeswan-1.5 - kernel 2.4 patches for those who need them.
Let me know. Feedback is appreciated.
Older patches:
These patches are for older versions of FreeS/WAN and
will likely not work with the current version. Older
versions of FreeS/WAN may be available on some of the distribution sites, but we recommend using the current
release.
Finally, there are some patches to other code that may be useful with FreeS/WAN:
Note that this is not required if the same machine does IPSEC and masquerading, only
if you want a to locate your IPSEC gateway on a masqueraded network. See our
firewalls document for discussion of why this is
problematic.
At last report, this patch could not co-exist with FreeS/WAN on the same machine.
The introductory section of our document set lists several Linux distributions which include FreeS/WAN.
- /dev/random support page,
discussion of and code for the Linux random number
driver. Out-of-date when we last checked (January 2000), but still
useful.
- other programs related to random numbers:
- a Linux L2TP Daemon which
might be useful for communicating with Windows 2000 which builds L2TP
tunnels over its IPSEC connections
- packet spy, a packet
sniffer whose author said in a Dec 1999 message "It's very unfinished,
especially the filter, but it can give you an ascii and hex dump at the
same time. I started it specifically for snooping a FreeS/WAN
installation."
- to use opportunistic encryption, you need a recent version of
BIND. Get one from the
FreeS/WAN site
or from the Internet Software Consortium
who maintain BIND.
- other Linux IPSEC implementations
- ENskip, a free
implementation of Sun's SKIP protocol
- vpnd, a non-IPSEC VPN daemon
for Linux which creates tunnels using Blowfish
encryption
- Zebedee, a simple GPLd
tunnel-building program with Linux and Win32 versions. The name is from
Zlib compression, Blowfish encryption
and Diffie-Hellman key exchange.
- LinuxCare's VPS (Virtual
Private Server) which builds tunnels using SSH
- Moreton Bay's PoPToP, PPTP for
Linux
- CIPE
(crypto IP routers)
project, using their own lightweight protocol to encrypt between
routers
- vtun "virtual tunnels", using
Blowfish
- tinc, a VPN Daemon
There is a list of
Linux VPN
software in the
Linux Security Knowledge Base.
- Our document listing the RFCs relevant to Linux
FreeS/WAN and giving various ways of obtaining both RFCs and Internet
Drafts.
- IPSEC standards
page maintained by VPNC. This covers both RFCs and
Drafts, and classifies them in a fairly helpful way.
- RFC archive
- Internet Drafts
related to IPSEC
- US government site
with their FIPS standards
- Archives of the ipsec@tis.com mailing list where discussion of drafts
takes place.
- Counterpane's evaluation of the
protocols
- Simpson's IKE
Considered Dangerous paper. Note that this is a link to an archive
of our mailing list. There are several replies in addition to the paper
itself.
- Bellovin's papers
page including his:
- Security Problems in the TCP/IP Protocol Suite (1989)
- Problem Areas for the IP Security Protocols (1996)
- Probable Plaintext Cryptanalysis of the IP Security Protocols
(1997)
- Catherine Meadows of NRL applied the NRL Protocol Analyzer to IKE. Her
paper is available in PDF
or Postscript.
- An errata list
for the IPSEC RFCs.
- An introduction to IP
addressing from 3Com
- An IP tutorial that seems
to be written mainly for Netware or Microsoft LAN admins entering a new
world
- IANA, Internet Assigned Numbers
Authority
- CIDR,
Classless Inter-Domain Routing
- Also see our bibliography
Vendors using FreeS/WAN in turnkey firewall or VPN products are listed in
our introduction.
Other vendors have Linux IPSEC products which, as far as we know, do not
use FreeS/WAN
- Redcreek
provide an open source Linux driver for their PCI hardware VPN card.
This card has a 100 Mbit Ethernet port, an Intel 960 CPU plus more
specialised crypto chips, and claimed encryption performance of 45
Mbit/sec. The PC sees it as an Ethernet board.
- Paktronix
offer a Linux-based VPN with hardware encryption
- According to a report on our mailing list, Watchguard use Linux in their
Firebox product.
- Entrust offer a developers'
toolkit for using their PKI for IPSEC
authentication
- According to a report on our mailing list, Axent
have a Linux version of their product.
All the major router vendors support IPSEC, at least in some models.
- Cisco IPSEC
information
- Ascend, now part of Lucent, have
some IPSEC-based products
- Bay Networks, now part of
Nortel, use IPSEC in their Contivity switch product line
- 3Com have a
number of VPN products, some using IPSEC
Many firewall vendors offer IPSEC, either as a standard part of their
product, or an optional extra. A few we know about are:
Vendors using FreeS/WAN in turnkey firewall products are listed in
our introduction.
All the major open source operating systems support IPSEC. See below for
details on BSD-derived Unix variants.
Among commercial OS vendors, IPSEC players include:
- Microsoft
have put IPSEC in their Windows 2000 products
- Apple's Mac OS X has IPSEC support built in
- IBM
announce a release of OS390 with IPSEC support via a crypto
co-processor
- Sun
include IPSEC in Solaris 8
- Hewlett
Packard offer IPSEC for their Unix machines
We like to think of FreeS/WAN as the Linux IPSEC implementation,
but it is not the only one. Others we know of are:
- pipsecd, a
lightweight implementation of IPSEC for Linux. Does not require kernel
recompilation.
- Petr Novak's ipnsec,
based on the OpenBSD IPSEC code and using Photuris for key management
- A now defunct project at U of
Arizona (export controlled)
- NIST Cerebus (export
controlled)
- KAME, several
large Japanese companies co-operating on IPv6 and IPSEC
- US Naval Research Lab
implementation of IPv6 and of IPSEC for IPv4 (export controlled)
- OpenBSD includes IPSEC as
a standard part of the distribution
- IPSEC for FreeBSD
- a FAQ
on NetBSD's IPSEC implementation
The IPSEC protocols are designed so that different implementations should
be able to work together. As they say "the devil is in the details". IPSEC
has a lot of details, but considerable success has been achieved.
Linux FreeS/WAN has been tested for interoperability with many other
IPSEC implementations. Results to date are in our interoperability section.
Various other sites have information on interoperability between various
IPSEC implementations:
- interop
results from a bakeoff in Atlanta, September 1999.
- a French company, HSC's, interoperability
test data covers FreeS/WAN, Open BSD, KAME, Linux pipsecd, Checkpoint, Red
Creek Ravlin, and Cisco IOS
- ICSA offer certification programs
for various security-related products. See their list of
certified IPSEC products. Linux FreeS/WAN is not currently on that
list, but several products with which we interoperate are.
- VPNC have a page on why they are not yet doing
interoperability testing and a
page on the spec conformance
testing that they are doning
- a review
comparing a dozen commercial IPSEC implemetations. Unfortunately, the
reviewers did not look at Open Source implementations such as FreeS/WAN
or OpenBSD.
- results
from interoperability tests at a conference. FreeS/WAN was not tested
there.
- test results from the IPSEC 2000 conference
The Linux IP stack is getting some new features in 2.4 kernels. Most are
already available as experimental code in 2.3 kernels. Some HowTos have been
written:
Two enormous collections of links, each the standard reference in its
area:
- Gene Spafford's COAST hotlist
- Computer and network security.
- Peter Gutmann's Encryption and
Security-related Resources
- Cryptography.
See also the interesting papers section
below.
- RFC
1984, the IAB and IESG
Statement on Cryptographic Technology and the Internet.
- John Young's collection of documents of interest to the
cryptography, open government and privacy movements, organized
chronologically
- Encryption, Privacy and Security Resource Page with a mainly US
focus
- Cryptography
Export Control Archive, mainly links to court and govenment
documents on various challenges to US law
- A good overview of
the issues from Australia.
See also our documentation section on the history and
politics of cryptography.
These papers emphasize important issues around the use of cryptography,
and the design and management of secure systems.
David Wagner at Berkeley provides a set of links to
home pages
of cryptographers, cypherpunks and computer security people.