ISAKMPD(8) OpenBSD System Manager's Manual ISAKMPD(8)
NAME
isakmpd - ISAKMP/Oakley a.k.a. IKE key management daemon
SYNOPSIS
isakmpd [-c config-file] [-d] [-D class=level] [-f fifo] [-i pid-file]
[-n] [-p listen-port] [-P local-port] [-L] [-l packetlog-file]
[-r seed] [-R report-file]
DESCRIPTION
The isakmpd daemon establishes security associations for encrypted and/or
authenticated network traffic. At this moment, and probably forever,
this means ipsec(4) traffic.
The way isakmpd goes about its work is by maintaining an internal config-
uration as well as a policy database which describes what kinds of SAs to
negotiate, and by listening for different events that triggers these ne-
gotiations. The events that control isakmpd consists of negotiation ini-
tiations from a remote party, user input via a FIFO or by signals, up-
calls from the kernel via a PF_KEY socket, and lastly by scheduled events
triggered by timers running out.
Most uses of isakmpd will be to implement so called "virtual private net-
works" or VPNs for short. The vpn(8) manual page describes how to setup
isakmpd for a simple VPN. For other uses, some more knowledge of IKE as
a protocol is required. One source of information are the RFCs mentioned
below.
The options are as follows:
-c config-file
If given, the -c option specifies an alternate configuration file
instead of /etc/isakmpd/isakmpd.conf. As this file may contain
sensitive information, it must be readable only by the user run-
ning the daemon.
-d The -d option is used to make the daemon run in the foreground,
logging to stderr.
-D class=level
Debugging class. This argument is possible to specify many
times. It takes a parameter of the form class=level where both
class and level are numbers. class denotes a debugging class,
and level the level you want that debugging class to limit debug
printouts at (i.e., all debug printouts above the level specified
will not output anything). If class is set to 'A', then all de-
bugging classes are set to the specified level.
Valid values for class are as follows:
0 Misc
1 Transport
2 Message
3 Crypto
4 Timer
5 Sysdep
6 SA
7 Exchange
8 Negotiation
9 Policy
A All
-f fifo
The -f option specifies the FIFO (a.k.a. named pipe) where the
daemon listens for user requests. If the path given is a dash
(`-'), isakmpd will listen to stdin instead.
-i pid-file
By default the PID of the daemon process will be written to
/var/run/isakmpd.pid. This path can be overridden by specifying
another one as the argument to the -i option.
-n When the -n option is given, the kernel will not take part in the
negotiations. This is a non-destructive mode so to say, in that
it won't alter any SAs in the IPSEC stack.
-p listen-port
The -p option specifies the listen port the daemon will bind to.
-P local-port
On the other hand, the port specified to capital -P will be what
the daemon binds its local end to when acting as initiator.
-L Enable IKE packet capture. When this option is given, isakmpd
will capture to file an unencrypted copy of the negotiation pack-
ets it is sending and receiveing. This file can later be read by
tcpdump(8) and other utilities using pcap(3).
-l packetlog-file
As option -L above, but capture to a specified file.
-r seed
If given a deterministic random number sequence will be used in-
ternally. This is useful for setting up regression tests.
-R report-file
When you signal isakmpd a SIGUSR1 it will report its internal
state to a report file, normally /var/run/isakmpd.report, but
this can be changed by feeding the file name as an argument to
the -R flag.
Setting up an IKE public key infrastructure (a.k.a. PKI)
In order to use public key based authentication, there has to be an in-
frastructure managing the key signing. Either there is an already exist-
ing PKI isakmpd should take part in, or there will be a need to setup
one. In the former case, what is needed to be done varies depending on
the actual Certificate Authority used, and is therefore not covered here,
more than mentioning that openssl(8) needs to be used to create a cer-
tificate signing request that the CA understands. The latter case howev-
er is described here:
1. An RSA-enabled libcrypto (see crypto(3)) needs to be installed.
This is described in ssl(8).
2. Create your own CA as root.
# openssl genrsa -out /etc/ssl/private/ca.key 1024
# openssl req -new -key /etc/ssl/private/ca.key \
-out /etc/ssl/private/ca.csr
You are now being asked to enter information that will be incorpo-
rated into your certificate request. What you are about to enter is
what is called a Distinguished Name or a DN. There are quite a few
fields but you can leave some blank. For some fields there will be
a default value, if you enter '.', the field will be left blank.
# openssl x509 -req -days 365 -in /etc/ssl/private/ca.csr \
-signkey /etc/ssl/private/ca.key \
-out /etc/ssl/ca.crt
3. Create keys and certificates for your IKE peers. This step as well
as the next one, needs to be done for every peer. Furthermore the
last step will need to be done once for each ID you want the peer to
have. The 10.0.0.1 below symbolizes that ID, and should be changed
for each invocation. You will be asked for a DN for each run too.
See to encode the ID in the common name too, so it gets unique.
# openssl genrsa -out /etc/isakmpd/private/local.key 1024
# openssl req -new -key /etc/isakmpd/private/local.key \
-out /etc/isakmpd/private/10.0.0.1.csr
Now take these certificate signing requests to your CA and process
them like below. You have to add some extensions to the certificate
in order to make it usable for isakmpd, which is why you will need
to run certpatch(8). Replace 10.0.0.1 with the IP-address which
isakmpd will be using for identity.
# openssl x509 -req -days 365 -in 10.0.0.1.csr -CA /etc/ssl/ca.crt \
-CAkey /etc/ssl/private/ca.key -CAcreateserial \
-out 10.0.0.1.crt
# certpatch -i 10.0.0.1 -k /etc/ssl/private/ca.key \
10.0.0.1.crt 10.0.0.1.crt
Put the certificate (the file ending in .crt) in /etc/isakmpd/certs/
on your local system. Also carry over the CA cert /etc/ssl/ca.crt
and put it in /etc/isakmpd/ca/.
BUGS
The -P flag does not do what we document, rather it does nothing.
FILES
/etc/isakmpd/ca/ The directory where CA certificates can be
found.
/etc/isakmpd/certs/ The directory where IKE certificates can be
found, both the local certificate(s) and those
of the peers, if a choice to have them kept per-
manently has been made.
/etc/isakmpd/isakmpd.conf
The configuration file. As this file can contain
sensitive information it must not be readable by
anyone but the user running isakmpd.
/etc/isakmpd/isakmpd.policy
The keynote policy configuration file. Same mode
requirements as for isakmpd.conf.
/etc/isakmpd/private/local.key
A local private key for certificate based au-
thentication. There has to be a certificate for
this key in the certificate directory mentioned
above. Same mode requirements as isakmpd.conf.
/var/run/isakmpd.fifo The FIFO used to manually control isakmpd.
/var/run/isakmpd.pcap The default IKE packet capture file.
/var/run/isakmpd.report The report file written when SIGUSR1 is re-
ceived.
SEE ALSO
ipsec(4), isakmpd.conf(5), isakmpd.policy(5), openssl(8), pcap(3),
photurisd(8), ssl(8), tcpdump(8), vpn(8)
HISTORY
The ISAKMP/Oakley key management protocol is described in the RFCs RFC
2407, RFC 2408 and RFC 2409. This implementation was done 1998 by Niklas
Hallqvist and Niels Provos, sponsored by Ericsson Radio Systems.
OpenBSD 2.9 July 31, 1998 4