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. isakmpd will reread the configuration file when
sent a SIGHUP signal.
-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
Currently used values for level are 0 to 99.
-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(1) needs to be used to create a cer-
tificate signing request that the CA understands. The latter case howev-
er is described here:
1. 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 \
-extfile /etc/ssl/x509v3.cnf -extensions x509v3_CA \
-out /etc/ssl/ca.crt
2. 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, in this case an IPv4
ID, and should be changed for each invocation. You will be asked
for a DN for each run. Encoding the ID in the common name is recom-
mended, as it should be 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. There are two possible ways
to add the extensions to the certificate. Either you have to to run
certpatch(8) or you have to make use of an OpenSSL configuration
file, for example /etc/ssl/x509v3.cnf. Replace 10.0.0.1 with the IP-
address which isakmpd will use as the certificate identity.
To use certpatch(8), do the following
# 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
Otherwise do
# setenv CERTIP 10.0.0.1
# openssl x509 -req -days 365 -in 10.0.0.1.csr -CA /etc/ssl/ca.crt \
-CAkey /etc/ssl/private/ca.key -CAcreateserial \
-extfile /etc/ssl/x509v3.cnf -extensions x509v3_IPAddr \
-out 10.0.0.1.crt
For a FQDN certificate, do
# setenv CERTFQDN somehost.somedomain
# openssl x509 -req -days 365 -in somehost.somedomain.csr \
-CA /etc/ssl/ca.crt -CAkey /etc/ssl/private/ca.key \
-CAcreateserial \
-extfile /etc/ssl/x509v3.cnf -extensions x509v3_FQDN \
-out somehost.somedomain.crt
(This assumes the previous steps were used to create a request for
somehost.somedomain instead of 10.0.0.1)
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/.
It is also possible to store trusted public keys to make them directly
usable by isakmpd. The keys should be saved in PEM format (see
openssl(1)) and named and stored after this easy formula:
For IPv4 identities /etc/isakmpd/pubkeys/ipv4/A.B.C.D
For IPv6 identities /etc/isakmpd/pubkeys/ipv6/abcd:abcd::ab:bc
For FQDN identities /etc/isakmpd/pubkeys/fqdn/foo.bar.org
For UFQDN identities /etc/isakmpd/pubkeys/ufqdn/user@foo.bar.org
The FIFO user interface
When isakmpd starts, it creates a FIFO (named pipe) where it listens for
user requests. All commands start with a single letter, followed by com-
mand-specific options. Available commands are:
c <name>
Start the named connection, if stopped or inactive.
C set [section]:tag=value
C rm [section]:tag
C rms [section]
Update the running isakmpd configuration atomically. 'set' sets a
configuration value consisting of a section, tag and value
triplet. 'rm' removes a tag in a section. 'rms' removes an entire
section.
d <cookies> <msgid>
Delete the specified SA from the system. Specify <msgid> as "-"
to match a Phase 1 SA.
D <class> <level>
D A <level>
D T Set debug class <class> to level <level>. If <class> is specified
as "A", the level applies to all debug classes. "D T" toggles
all debug classes to level zero. Another "D T" command will tog-
gle them back to the earlier levels.
p on[=<path>]
p off Enable or disable cleartext IKE packet capture. When enabling,
optionally specify which file isakmpd should capture the packets
to.
Q Cleanly shutdown of the daemon, as when sent a SIGTERM signal.
r Report isakmpd internal state to a file. See -R option. Same as
when sent a SIGUSR1 signal.
R Reinitialize isakmpd, as when sent a SIGHUP signal.
S Report information on all known SAs to the /var/run/isakmpd_sa
file.
t <name>
Tear down the named connection, if active.
T Tear down all active connections.
BUGS
The -P flag does not do what we document, rather it does nothing.
CAVEATS
When storing a trusted public key for an IPv6 identity, the most
efficient form of address representation, i.e "::" instead of ":0:0:0:",
must be used or the matching will fail. isakmpd uses the output from
getnameinfo(3) for the address-to-name translation.
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 permanently 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. The
same mode requirements as isakmpd.conf.
/etc/isakmpd/private/local.key
A local private key for certificate based
authentication. There has to be a certifi-
cate for this key in the certificate direc-
tory mentioned above. The same mode re-
quirements as isakmpd.conf.
/etc/isakmpd/pubkeys/ Directory in which trusted public keys can
be kept. The keys must be named after a
fashion described above.
/var/run/isakmpd.pid The PID of the current daemon.
/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.
/var/run/isakmpd_sa The report file written when the 'S' command
is issued in the command FIFO.
/usr/share/ipsec/isakmpd/ A directory containing some sample isakmpd
and keynote policy configuration files.
SEE ALSO
ipsec(4), isakmpd.conf(5), isakmpd.policy(5), getnameinfo(3), openssl(1),
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 3.1 July 31, 1998 5