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<H1><A name="compat">Linux FreeS/WAN Compatibility Guide</A></H1>
<P>Much of this document is quoted directly from the Linux FreeS/WAN<A href="mail.html">
mailing list</A>. Thanks very much to the community of testers,
patchers and commenters there, especially the ones quoted below but
also various contributors we haven't quoted.</P>
<H2><A name="spec">Implemented parts of the IPsec Specification</A></H2>
<P>In general, do not expect Linux FreeS/WAN to do everything yet. This
is a work-in-progress and some parts of the IPsec specification are not
yet implemented.</P>
<H3><A name="in">In Linux FreeS/WAN</A></H3>
<P>Things we do, as of version 1.96:</P>
<UL>
<LI>key management methods
<DL>
<DT>manually keyed</DT>
<DD>using keys stored in /etc/ipsec.conf</DD>
<DT>automatically keyed</DT>
<DD>Automatically negotiating session keys as required. All connections
are automatically re-keyed periodically. The<A href="glossary.html#Pluto">
Pluto</A> daemon implements this using the<A href="glossary.html#IKE">
IKE</A> protocol.</DD>
</DL>
</LI>
<LI>Methods of authenticating gateways for IKE
<DL>
<DT>shared secrets</DT>
<DD>stored in<A href="manpage.d/ipsec.secrets.5.html"> ipsec.secrets(5)</A>
</DD>
<DT><A href="glossary.html#RSA">RSA</A> signatures</DT>
<DD>For details, see<A href="manpage.d/ipsec_pluto.8.html"> pluto(8)</A>
.</DD>
<DT>looking up RSA authentication keys from<A href="glossary.html#DNS">
DNS</A>.</DT>
<DD>Note that this technique cannot be fully secure until<A href="glossary.html#SDNS">
secure DNS</A> is widely deployed.</DD>
</DL>
</LI>
<LI>groups for<A href="glossary.html#DH"> Diffie-Hellman</A> key
negotiation
<DL>
<DT>group 2, modp 1024-bit</DT>
<DT>group 5, modp 1536-bit</DT>
<DD>We implement these two groups.
<P>In negotiating a keying connection (ISAKMP SA, Phase 1) we propose
both groups when we are the initiator, and accept either when a peer
proposes them. Once the keying connection is made, we propose only the
alternative agreed there for data connections (IPsec SA's, Phase 2)
negotiated over that keying connection.</P>
</DD>
</DL>
</LI>
<LI>encryption transforms
<DL>
<DT><A href="glossary.html#DES">DES</A></DT>
<DD>DES is in the source code since it is needed to implement 3DES, but
single DES is not made available to users because<A href="politics.html#desnotsecure">
DES is insecure</A>.</DD>
<DT><A href="glossary.html#3DES">Triple DES</A></DT>
<DD>implemented, and used as the default encryption in Linux FreeS/WAN.</DD>
</DL>
</LI>
<LI>authentication transforms
<DL>
<DT><A href="glossary.html#HMAC">HMAC</A> using<A href="glossary.html#MD5">
MD5</A></DT>
<DD>implemented, may be used in IKE or by by AH or ESP transforms.</DD>
<DT><A href="glossary.html#HMAC">HMAC</A> using<A href="glossary.html#SHA">
SHA</A></DT>
<DD>implemented, may be used in IKE or by AH or ESP transforms.</DD>
</DL>
<P>In negotiations, we propose both of these and accept either.</P>
</LI>
<LI>compression transforms
<DL>
<DT>IPComp</DT>
<DD>IPComp as described in RFC 2393 was added for FreeS/WAN 1.6. Note
that Pluto becomes confused if you ask it to do IPComp when the kernel
cannot.</DD>
</DL>
</LI>
</UL>
<P>All combinations of implemented transforms are supported. Note that
some form of packet-level<STRONG> authentication is required whenever
encryption is used</STRONG>. Without it, the encryption will not be
secure.</P>
<H3><A name="dropped">Deliberately omitted</A></H3>
We do not implement everything in the RFCs because some of those things
are insecure. See our discussions of avoiding<A href="politics.html#weak">
bogus security</A>.
<P>Things we deliberately omit which are required in the RFCs are:</P>
<UL>
<LI>null encryption (to use ESP as an authentication-only service)</LI>
<LI>single DES</LI>
<LI>DH group 1, a 768-bit modp group</LI>
</UL>
<P>Since these are the only encryption algorithms and DH group the RFCs
require, it is possible in theory to have a standards-conforming
implementation which will not interpoperate with FreeS/WAN. Such an
implementation would be inherently insecure, so we do not consider this
a problem.</P>
<P>Anyway, most implementations sensibly include more secure options as
well, so dropping null encryption, single DES and Group 1 does not
greatly hinder interoperation in practice.</P>
<P>We also do not implement some optional features allowed by the RFCs:</P>
<UL>
<LI>aggressive mode for negotiation of the keying channel or ISAKMP SA.
This mode is a little faster than main mode, but exposes more
information to an eavesdropper.</LI>
</UL>
<P>In theory, this should cause no interoperation problems since all
implementations are required to support the more secure main mode,
whether or not they also allow aggressive mode.</P>
<P>In practice, it does sometimes produce problems with implementations
such as Windows 2000 where aggressive mode is the default. Typically,
these are easily solved with a configuration change that overrides that
default.</P>
<H3><A name="not">Not (yet) in Linux FreeS/WAN</A></H3>
<P>Things we don't yet do, as of version 1.96:</P>
<UL>
<LI>key management methods
<UL>
<LI>authenticate key negotiations via local<A href="glossary.html#PKI">
PKI</A> server, but see links to user<A href="web.html#patch"> patches</A>
</LI>
<LI>authenticate key negotiations via<A href="glossary.html#SDNS">
secure DNS</A></LI>
<LI>unauthenticated key management, using<A href="glossary.html#DH">
Diffie-Hellman</A> key agreement protocol without authentication.
Arguably, this would be worth doing since it is secure against all
passive attacks. On the other hand, it is vulnerable to an active<A href="glossary.html#middle">
man-in-the-middle attack</A>.</LI>
</UL>
</LI>
<LI>encryption transforms
<P>Currently<A href="glossary.html#3DES"> Triple DES</A> is the only
encryption method Pluto will negotiate.</P>
<P>No additional encryption transforms are implemented, though the RFCs
allow them and some other IPsec implementations support various of
them. We are not eager to add more. See this<A href="faq.html#other.cipher">
FAQ question</A>.</P>
<P><A href="glossary.html#AES">AES</A>, the successor to the DES
standard, is an excellent candidate for inclusion in FreeS/WAN, see
links to user<A href="web.html#patch"> patches</A>.</P>
</LI>
<LI>authentication transforms
<P>No optional additional authentication transforms are currently
implemented. Likely<A href="glossary.html#SHA-256"> SHA-256, SHA-384
and SHA-512</A> will be added when AES is.</P>
</LI>
<LI>Policy checking on decrypted packets
<P>To fully comply with the RFCs, it is not enough just to accept only
packets which survive any firewall rules in place to limit what IPsec
packets get in, and then pass KLIPS authentication. That is what
FreeS/WAN currently does.</P>
<P>We should also apply additional tests, for example ensuring that all
packets emerging from a particular tunnel have source and destination
addresses that fall within the subnets defined for that tunnel, and
that packets with those addresses that did not emerge from the
appropriate tunnel are disallowed.</P>
<P>This will be done as part of a KLIPS rewrite. See these<A href="intro.html#applied">
links</A> and the<A href="mail.html"> design mailing list</A> for
discussion.</P>
</LI>
</UL>
<H2><A name="pfkey">Our PF-Key implementation</A></H2>
<P>We use PF-key Version Two for communication between the KLIPS kernel
code and the Pluto Daemon. PF-Key v2 is defined by<A href="http://www.normos.org/ietf/rfc/rfc2367.txt">
RFC 2367</A>.</P>
<P>The "PF" stands for Protocol Family. PF-Inet defines a
kernel/userspace interface for the TCP/IP Internet protocols (TCP/IP),
and other members of the PF series handle Netware, Appletalk, etc.
PF-Key is just a PF for key-related matters.</P>
<H3><A name="pfk.port">PF-Key portability</A></H3>
<P>PF-Key came out of Berkeley Unix work and is used in the various BSD
IPsec implementations, and in Solaris. This means there is some hope of
porting our Pluto(8) to one of the BSD distributions, or of running
their photurisd(8) on Linux if you prefer<A href="glossary.html#photuris">
Photuris</A> key management over IKE.</P>
<P>It is, however, more complex than that. The PK-Key RFC deliberately
deals only with keying, not policy management. The three PF-Key
implementations we have looked at -- ours, OpenBSD and KAME -- all have
extensions to deal with security policy, and the extensions are
different. There have been discussions aimed at sorting out the
differences, perhaps for a version three PF-Key spec. All players are
in favour of this, but everyone involved is busy and it is not clear
whether or when these discussions might bear fruit.</P>
<H2><A name="otherk">Kernels other than the latest 2.2.x and 2.4.y</A></H2>
<P>We develop and test on Redhat Linux using the most recent kernel in
the 2.2 and 2.4 series. In general, we recommend you use the latest
kernel in one of those series. Complications and caveats are discussed
below.</P>
<H3><A name="kernel.2.0">2.0.x kernels</A></H3>
<P>Consider upgrading to the 2.2 kernel series. If you want to stay with
the 2.0 series, then we strongly recommend 2.0.39. Some useful security
patches were added in 2.0.38.</P>
<P>Various versions of the code have run at various times on most 2.0.xx
kernels, but the current version is only lightly tested on 2.0.39, and
not at all on older kernels.</P>
<P>Some of our patches for older kernels are shipped in 2.0.37 and
later, so they are no longer provided in FreeS/WAN. This means recent
versions of FreeS/WAN will probably not compile on anything earlier
than 2.0.37.</P>
<H3><A name="kernel.production">2.2 and 2.4 kernels</A></H3>
<DL>
<DT>FreeS/WAN 1.0</DT>
<DD>ran only on 2.0 kernels</DD>
<DT>FreeS/WAN 1.1 to 1.8</DT>
<DD>ran on 2.0 or 2.2 kernels
<BR> ran on some development kernels, 2.3 or 2.4-test</DD>
<DT>FreeS/WAN 1.9 to 1.96</DT>
<DD>runs on 2.0, 2.2 or 2.4 kernels</DD>
</DL>
<P>In general,<STRONG> we suggest the latest 2.2 kernel or 2.4 for
production use</STRONG>.</P>
<P>Of course no release can be guaranteed to run on kernels more recent
than it is, so quite often there will be no stable FreeS/WAN for the
absolute latest kernel. See the<A href="faq.html#k.versions"> FAQ</A>
for discussion.</P>
<H2><A name="otherdist">Intel Linux distributions other than Redhat</A></H2>
<P>We develop and test on Redhat 6.1 for 2.2 kernels, and on Redhat 7.1
or 7.2 for 2.4, so minor changes may be required for other
distributions.</P>
<H3><A name="rh7">Redhat 7.0</A></H3>
<P>There are some problems with FreeS/WAN on Redhat 7.0. They are
soluble, but we recommend you upgrade to a later Redhat instead..</P>
<P>Redhat 7 ships with two compilers.</P>
<UL>
<LI>Their<VAR> gcc</VAR> is version 2.96. Various people, including the
GNU compiler developers and Linus, have said fairly emphatically that
using this was a mistake. 2.96 is a development version, not intended
for production use. In particular, it will not compile a Linux kernel.</LI>
<LI>Redhat therefore also ship a separate compiler, which they call<VAR>
kgcc</VAR>, for compiling kernels.</LI>
</UL>
<P>Kernel Makefiles have<VAR> gcc</VAR> as a default, and must be
adjusted to use<VAR> kgcc</VAR> before a kernel will compile on 7.0.
This mailing list message gives details:</P>
<PRE>Subject: Re: AW: Installing IPsec on Redhat 7.0
Date: Thu, 1 Feb 2001 14:32:52 -0200 (BRST)
From: Mads Rasmussen <mads@cit.com.br>
> From www.redhat.com/support/docs/gotchas/7.0/gotchas-7-6.html#ss6.1
cd to /usr/src/linux and open the Makefile in your favorite editor. You
will need to look for a line similar to this:
CC = $(CROSS_COMPILE)gcc -D__KERNEL__ -I$(HPATH)
This line specifies which C compiler to use to build the kernel. It should
be changed to:
CC = $(CROSS_COMPILE)kgcc -D__KERNEL__ -I$(HPATH)
for Red Hat Linux 7. The kgcc compiler is egcs 2.91.66. From here you can
proceed with the typical compiling steps.</PRE>
<P>Check the<A href="mail.html"> mailing list</A> archive for more
recent news.</P>
<H3><A name="suse">SuSE Linux</A></H3>
<P>SuSE 6.3 and later versions, at least in Europe, ship with FreeS/WAN
included.</P>
<P>FreeS/WAN packages distributed for SuSE 7.0-7.2 were somehow
miscompiled. You can find fixed packages on<A HREF="http://www.suse.de/~garloff/linux/FreeSWAN">
Kurt Garloff's page</A>.</P>
<P>Here are some notes for an earlier SuSE version.</P>
<H4>SuSE Linux 5.3</H4>
<PRE>Date: Mon, 30 Nov 1998
From: Peter Onion <ponion@srd.bt.co.uk>
... I got Saturdays snapshot working between my two SUSE5.3 machines at home.
The mods to the install process are quite simple. From memory and looking at
the files on the SUSE53 machine here at work....
And extra link in each of the /etc/init.d/rc?.d directories called K35ipsec
which SUSE use to shut a service down.
A few mods in /etc/init.d/ipsec to cope with the different places that SUSE
put config info, and remove the inculsion of /etc/rc.d/init.d/functions and .
/etc/sysconfig/network as they don't exists and 1st one isn't needed anyway.
insert ". /etc/rc.config" to pick up the SUSE config info and use
if test -n "$NETCONFIG" -a "$NETCONFIG" != "YAST_ASK" ; then
to replace
[ ${NETWORKING} = "no" ] && exit 0
Create /etc/sysconfig as SUSE doesn't have one.
I think that was all (but I prob forgot something)....</PRE>
<P>You may also need to fiddle initialisation scripts to ensure that<VAR>
/var/run/pluto/pluto.pid</VAR> is removed when rebooting. If this file is
present, Pluto does not come up correctly.</P>
<H3><A name="slack">Slackware</A></H3>
<PRE>Subject: Re: linux-IPsec: Slackware distribution
Date: Thu, 15 Apr 1999 12:07:01 -0700
From: Evan Brewer <dmessiah@silcon.com>
> Very shortly, I will be needing to install IPsec on at least gateways that
> are running Slackware. . . .
The only trick to getting it up is that on the slackware dist there is no
init.d directory in /etc/rc.d .. so create one. Then, what I do is take the
IPsec startup script which normally gets put into the init.d directory, and
put it in /etc/rc.d and name ir rc.ipsec .. then I symlink it to the file
in init.d. The only file in the dist you need to really edit is the
utils/Makefile, setup4:
Everything else should be just fine.</PRE>
<P>A year or so later:</P>
<PRE>Subject: Re: HTML Docs- Need some cleanup?
Date: Mon, 8 Jan 2001
From: Jody McIntyre <jodym@oeone.com>
I have successfully installed FreeS/WAN on several Slackware 7.1 machines.
FreeS/WAN installed its rc.ipsec file in /etc/rc.d. I had to manually call
this script from rc.inet2. This seems to be an easier method than Evan
Brewer's.</PRE>
<H3><A name="deb">Debian</A></H3>
<P>A recent (Nov 2001) mailing list points to a<A href="http://www.thing.dyndns.org/debian/vpn.htm">
web page</A> on setting up several types of tunnel, including IPsec, on
Debian.</P>
<P>Some older information:</P>
<PRE>Subject: FreeS/WAN 1.0 on Debian 2.1
Date: Tue, 20 Apr 1999
From: Tim Miller <cerebus+counterpane@haybaler.sackheads.org>
Compiled and installed without error on a Debian 2.1 system
with kernel-source-2.0.36 after pointing RCDIR in utils/Makefile to
/etc/init.d.
/var/lock/subsys/ doesn't exist on Debian boxen, needs to be
created; not a fatal error.
Finally, IPsec scripts appear to be dependant on GNU awk
(gawk); the default Debian awk (mawk-1.3.3-2) had fatal difficulties.
With gawk installed and /etc/alternatives/awk linked to /usr/bin/gawk
operation appears flawless.</PRE>
<P>The scripts in question have been modified since this was posted. Awk
versions should no longer be a problem.</P>
<H3><A name="caldera">Caldera</A></H3>
<PRE>Subject: Re: HTML Docs- Need some cleanup?
Date: Mon, 08 Jan 2001
From: Andy Bradford <andyb@calderasystems.com>
On Sun, 07 Jan 2001 22:59:05 EST, Sandy Harris wrote:
> Intel Linux distributions other than Redhat 5.x and 6.x
> Redhat 7.0
> SuSE Linux
> SuSE Linux 5.3
> Slackware
> Debian
Can you please include Caldera in this list? I have tested it since
FreeS/Wan 1.1 and it works great with our systems---provided one
follows the FreeS/Wan documentation. :-)
Thank you,
Andy</PRE>
<H2><A name="CPUs">CPUs other than Intel</A></H2>
<P>FreeS/WAN has been run sucessfully on a number of different CPU
architectures. If you have tried it on one not listed here, please post
to the<A href="mail.html"> mailing list</A>.</P>
<H3><A name=" strongarm">Corel Netwinder (StrongARM CPU)</A></H3>
<PRE>Subject: linux-ipsec: Netwinder diffs
Date: Wed, 06 Jan 1999
From: rhatfield@plaintree.com
I had a mistake in my IPsec-auto, so I got things working this morning.
Following are the diffs for my changes. Probably not the best and cleanest way
of doing it, but it works. . . . </PRE>
<P>These diffs are in the 0.92 and later distributions, so these should
work out-of-the-box on Netwinder.</P>
<H3><A name="yellowdog">Yellow Dog Linux on Power PC</A></H3>
<PRE>Subject: Compiling FreeS/WAN 1.1 on YellowDog Linux (PPC)
Date: 11 Dec 1999
From: Darron Froese <darron@fudgehead.com>
I'm summarizing here for the record - because it's taken me many hours to do
this (multiple times) and because I want to see IPsec on more linuxes than
just x86.
Also, I can't remember if I actually did summarize it before... ;-) I'm
working too many late hours.
That said - here goes.
1. Get your linux kernel and unpack into /usr/src/linux/ - I used 2.2.13.
<http://www.kernel.org/pub/linux/kernel/v2.2/linux-2.2.13.tar.bz2>
2. Get FreeS/WAN and unpack into /usr/src/freeswan-1.1
<ftp://ftp.xs4all.nl/pub/crypto/freeswan/freeswan-1.1.tar.gz>
3. Get the gmp src rpm from here:
<ftp://ftp.yellowdoglinux.com//pub/yellowdog/champion-1.1/SRPMS/SRPMS/gmp-2.0.2-9a.src.rpm>
4. Su to root and do this: rpm --rebuild gmp-2.0.2-9a.src.rpm
You will see a lot of text fly by and when you start to see the rpm
recompiling like this:
Executing: %build
+ umask 022
+ cd /usr/src/redhat/BUILD
+ cd gmp-2.0.2
+ libtoolize --copy --force
Remember to add `AM_PROG_LIBTOOL' to `configure.in'.
You should add the contents of `/usr/share/aclocal/libtool.m4' to
`aclocal.m4'.
+ CFLAGS=-O2 -fsigned-char
+ ./configure --prefix=/usr
Hit Control-C to stop the rebuild. NOTE: We're doing this because for some
reason the gmp source provided with FreeS/WAN 1.1 won't build properly on
ydl.
cd /usr/src/redhat/BUILD/
cp -ar gmp-2.0.2 /usr/src/freeswan-1.1/
cd /usr/src/freeswan-1.1/
rm -rf gmp
mv gmp-2.0.2 gmp
5. Open the freeswan Makefile and change the line that says:
KERNEL=$(b)zimage (or something like that) to
KERNEL=vmlinux
6. cd ../linux/
7. make menuconfig
Select an option or two and then exit - saving your changes.
8. cd ../freeswan-1.1/ ; make menugo
That will start the whole process going - once that's finished compiling,
you have to install your new kernel and reboot.
That should build FreeS/WAN on ydl (I tried it on 1.1).</PRE>
And a later message on the same topic:
<PRE>Subject: Re: FreeS/WAN, PGPnet and E-mail
Date: Sat, 22 Jan 2000
From: Darron Froese <darron@fudgehead.com>
on 1/22/00 6:47 PM, Philip Trauring at philip@trauring.com wrote:
> I have a PowerMac G3 ...
The PowerMac G3 can run YDL 1.1 just fine. It should also be able to run
FreeS/WAN 1.2patch1 with a couple minor modifications:
1. In the Makefile it specifies a bzimage for the kernel compile - you have
to change that to vmlinux for the PPC.
2. The gmp source that comes with FreeS/WAN (for whatever reason) fails to
compile. I have gotten around this by getting the gmp src rpm from here:
ftp://ftp.yellowdoglinux.com//pub/yellowdog/champion-1.1/SRPMS/SRPMS/gmp-2.0.2-9a.src.rpm
If you rip the source out of there - and place it where the gmp source
resides it will compile just fine.</PRE>
<P>FreeS/WAN no longer includes GMP source.</P>
<H3><A name="mklinux">Mklinux</A></H3>
<P>One user reports success on the Mach-based<STRONG> m</STRONG>icro<STRONG>
k</STRONG>ernel Linux.</P>
<PRE>Subject: Smiles on sparc and ppc
Date: Fri, 10 Mar 2000
From: Jake Hill <jah@alien.bt.co.uk>
You may or may not be interested to know that I have successfully built
FreeS/WAN on a number of non intel alpha architectures; namely on ppc
and sparc and also on osfmach3/ppc (MkLinux). I can report that it just
works, mostly, with few changes.</PRE>
<H3><A name="alpha">Alpha 64-bit processors</A></H3>
<PRE>Subject: IT WORKS (again) between intel & alpha :-)))))
Date: Fri, 29 Jan 1999
From: Peter Onion <ponion@srd.bt.co.uk>
Well I'm happy to report that I've got an IPsec connection between by intel & alpha machines again :-))
If you look back on this list to 7th of December I wrote...
-On 07-Dec-98 Peter Onion wrote:
->
-> I've about had enuf of wandering around inside the kernel trying to find out
-> just what is corrupting outgoing packets...
-
-Its 7:30 in the evening .....
-
-I FIXED IT :-))))))))))))))))))))))))))))))))
-
-It was my own fault :-((((((((((((((((((
-
-If you ask me very nicly I'll tell you where I was a little too over keen to
-change unsigned long int __u32 :-) OPSE ...
-
-So tomorrow it will full steam ahead to produce a set of diffs/patches against
-0.91
-
-Peter Onion.</PRE>
<P>In general (there have been some glitches), FreeS/WAN has been
running on Alphas since then.</P>
<H3><A name="SPARC">Sun SPARC processors</A></H3>
<P>Several users have reported success with FreeS/WAN on SPARC Linux.
Here is one mailing list message:</P>
<PRE>Subject: Smiles on sparc and ppc
Date: Fri, 10 Mar 2000
From: Jake Hill <jah@alien.bt.co.uk>
You may or may not be interested to know that I have successfully built
FreeS/WAN on a number of non intel alpha architectures; namely on ppc
and sparc and also on osfmach3/ppc (MkLinux). I can report that it just
works, mostly, with few changes.
I have a question, before I make up some patches. I need to hack
gmp/mpn/powerpc32/*.s to build them. Is this ok? The changes are
trivial, but could I also use a different version of gmp? Is it vanilla
here?
I guess my only real headache is from ipchains, which appears to stop
running when IPsec has been started for a while. This is with 2.2.14 on
sparc.</PRE>
<P>This message, from a different mailing list, may be relevant for
anyone working with FreeS/WAN on Suns:</P>
<PRE>Subject: UltraSPARC DES assembler
Date: Thu, 13 Apr 2000
From: svolaf@inet.uni2.dk (Svend Olaf Mikkelsen)
To: coderpunks@toad.com
An UltraSPARC assembler version of the LibDES/SSLeay/OpenSSL des_enc.c
file is available at http://inet.uni2.dk/~svolaf/des.htm.
This brings DES on UltraSPARC from slower than Pentium at the same
clock speed to significantly faster.</PRE>
<H3><A name="mips">MIPS processors</A></H3>
<P>We know FreeS/WAN runs on at least some MIPS processors because<A href="http://www.lasat.com">
Lasat</A> manufacture an IPsec box based on an embedded MIPS running
Linux with FreeS/WAN. We have no details.</P>
<H3><A name="crusoe">Transmeta Crusoe</A></H3>
<P>The Merilus<A href="http://www.merilus.com/products/fc/index.shtml">
Firecard</A>, a Linux firewall on a PCI card, is based on a Crusoe
processor and supports FreeS/WAN.</P>
<H3><A name="coldfire">Motorola Coldfire</A></H3>
<PRE>Subject: Re: Crypto hardware support
Date: Mon, 03 Jul 2000
From: Dan DeVault <devault@tampabay.rr.com>
.... I have been running
uClinux with FreeS/WAN 1.4 on a system built by Moreton Bay (
http://www.moretonbay.com ) and it was using a Coldfire processor
and was able to do the Triple DES encryption at just about
1 mbit / sec rate....... they put a Hi/Fn 7901 hardware encryption
chip on their board and now their system does over 25 mbit of 3DES
encryption........ pretty significant increase if you ask me.</PRE>
<H2><A name="multiprocessor">Multiprocessor machines</A></H2>
<P>FreeS/WAN is designed to work on SMP (symmetric multi-processing)
Linux machines and is regularly tested on dual processor x86 machines.</P>
<P>We do not know of any testing on multi-processor machines with other
CPU architectures or with more than two CPUs. Anyone who does test
this, please report results to the<A href="mail.html"> mailing list</A>
.</P>
<P>The current design does not make particularly efficient use of
multiprocessor machines; some of the kernel work is single-threaded.</P>
<H2><A name="hardware">Support for crypto hardware</A></H2>
<P>Supporting hardware cryptography accelerators has not been a high
priority for the development team because it raises a number of fairly
complex issues:</P>
<UL>
<LI>Can you trust the hardware? If it is not Open Source, how do you
audit its security? Even if it is, how do you check that the design has
no concealed traps?</LI>
<LI>If an interface is added for such hardware, can that interface be
subverted or misused?</LI>
<LI>Is hardware acceleration actually a performance win? It clearly is
in many cases, but on a fast machine it might be better to use the CPU
for the encryption than to pay the overheads of moving data to and from
a crypto board.</LI>
<LI>the current KLIPS code does not provide a clean interface for
hardware accelerators</LI>
</UL>
<P>That said, we have a<A href="#coldfire"> report</A> of FreeS/WAN
working with one crypto accelerator and some work is going on to modify
KLIPS to create a clean generic interface to such products. See this<A href="http://www.jukie.net/~bart/linux-ipsec/">
web page</A> for some of the design discussion.</P>
<P>More recently, a patch to support some hardware accelerators has been
posted:</P>
<PRE>Subject: [Design] [PATCH] H/W acceleration patch
Date: Tue, 18 Sep 2001
From: "Martin Gadbois" <martin.gadbois@colubris.com>
Finally!!
Here's a web site with H/W acceleration patch for FreeS/WAN 1.91, including
S/W and Hifn 7901 crypto support.
http://sources.colubris.com/
Martin Gadbois</PRE>
<P>Hardware accelerators could take performance well beyond what
FreeS/WAN can do in software (discussed<A href="performance.html"> here</A>
). Here is some discussion off the IETF IPsec list, October 2001:</P>
<PRE> ... Currently shipping chips deliver, 600 mbps throughput on a single
stream of 3DES IPsec traffic. There are also chips that use multiple
cores to do 2.4 gbps. We (Cavium) and others have announced even faster
chips. ... Mid 2002 versions will handle at line rate (OC48 and OC192)
IPsec and SSL/TLS traffic not only 3DES CBC but also AES and arc4.</PRE>
<P>The patches to date support chips that have been in production for
some time, not the state-of-the-art latest-and-greatest devices
described in that post. However, they may still outperform software and
they almost certainly reduce CPU overhead.</P>
<H2><A name="ipv6">IP version 6 (IPng)</A></H2>
<P>The Internet currently runs on version four of the IP protocols. IPv4
is what is in the standard Linux IP stack, and what FreeS/WAN was built
for. In IPv4, IPsec is an optional feature.</P>
<P>The next version of the IP protocol suite is version six, usually
abbreviated either as "IPv6" or as "IPng" for "IP: the next
generation". For IPv6, IPsec is a required feature. Any machine doing
IPv6 is required to support IPsec, much as any machine doing (any
version of) IP is required to support ICMP.</P>
<P>There is a Linux implementation of IPv6 in Linux kernels 2.2 and
above. For details, see the<A href="http://www.cs-ipv6.lancs.ac.uk/ipv6/systems/linux/faq/">
FAQ</A>. It does not yet support IPsec. The<A href="http://www.linux-ipv6.org/">
USAGI</A> project are also working on IPv6 for Linux.</P>
<P>FreeS/WAN was originally built for the current standard, IPv4, but we
are interested in seeing it work with IPv6. Some progress has been
made, and a patched version with IPv6 support is<A href="http://www.ipv6.iabg.de/downloadframe/index.html">
available</A>. For more recent information, check the<A href="mail.html">
mailing list</A>.</P>
<H3><A name="v6.back">IPv6 background</A></H3>
<P>IPv6 has been specified by an IETF<A href="http://www.ietf.org/html.charters/ipngwg-charter.html">
working group</A>. The group's page lists over 30 RFCs to date, and
many Internet Drafts as well. The overview is<A href="http://www.ietf.org/rfc/rfc2460.txt">
RFC 2460</A>. Major features include:</P>
<UL>
<LI>expansion of the address space from 32 to 128 bits,</LI>
<LI>changes to improve support for
<UL>
<LI>mobile IP</LI>
<LI>automatic network configuration</LI>
<LI>quality of service routing</LI>
<LI>...</LI>
</UL>
</LI>
<LI>improved security via IPsec</LI>
</UL>
<P>A number of projects are working on IPv6 implementation. A prominent
Open Source effort is<A href="http://www.kame.net/"> KAME</A>, a
collaboration among several large Japanese companies to implement IPv6
for Berkeley Unix. Other major players are also working on IPv6. For
example, see pages at:</P>
<UL>
<LI><A href="http://playground.sun.com/pub/ipng/html/ipng-main.html">Sun</A>
</LI>
<LI><A href="http://www.cisco.com/warp/public/732/ipv6/index.html">Cisco</A>
</LI>
<LI><A href="http://www.microsoft.com/windows2000/techinfo/howitworks/communications/networkbasics/IPv6.asp">
Microsoft</A></LI>
</UL>
<P>The<A href="http://www.6bone.net/"> 6bone</A> (IPv6 backbone) testbed
network has been up for some time. There is an active<A href="http://www.ipv6.org/">
IPv6 user group</A>.</P>
<P>One of the design goals for IPv6 was that it must be possible to
convert from v4 to v6 via a gradual transition process. Imagine the
mess if there were a "flag day" after which the entire Internet used
v6, and all software designed for v4 stopped working. Almost every
computer on the planet would need major software changes! There would
be huge costs to replace older equipment. Implementers would be worked
to death before "the day", systems administrators and technical support
would be completely swamped after it. The bugs in every implementation
would all bite simultaneously. Large chunks of the net would almost
certainly be down for substantial time periods. ...</P>
<P>Fortunately, the design avoids any "flag day". It is therefore a
little tricky to tell how quickly IPv6 will take over. The transition
has certainly begun. For examples, see announcements from<A href="http://www.mailbase.ac.uk/lists/internet2/2000-03/0016.html">
NTT</A> and<A href="http://www.vnunet.com/News/1102383"> Nokia</A>.
However, it is not yet clear how quickly the process will gain
momentum, or when it will be completed. Likely large parts of the
Internet will remain with IPv4 for years to come.</P>
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