Switch to SpeakEasy.net DSL

The Modular Manual Browser

Home Page
Manual: (OpenBSD-3.6)
Apropos / Subsearch:
optional field

ISAKMPD(8)              OpenBSD System Manager's Manual             ISAKMPD(8)

     isakmpd - ISAKMP/Oakley a.k.a. IKE key management daemon

     isakmpd [-4] [-6] [-c config-file] [-a] [-d] [-D class=level] [-f fifo]
             [-i pid-file] [-n] [-p listen-port] [-P local-port] [-K] [-L]
             [-l packetlog-file] [-r seed] [-R report-file] [-v]

     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 trigger these nego-
     tiations.  The events that control isakmpd consist of negotiation initia-
     tions from a remote party, user input via a FIFO or by signals, upcalls
     from the kernel via a PF_KEY socket, and lastly by scheduled events trig-
     gered 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 set up
     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

     On startup isakmpd forks into two processes for privilege separation.
     The unprivileged child jails itself with chroot(8) to /var/empty.  The
     privileged process communicates with the child, reads configuration files
     and PKI information and binds to privileged ports on its behalf.  See
     CAVEATS section below.

     The options are as follows:

     -4 | -6
             These options control what address family (AF_INET and/or
             AF_INET6) isakmpd will use.  The default is to use both IPv4 and

     -a      If given, isakmpd does not set up flows automatically.  This is
             useful when flows are configured with ipsecadm(4) or by other
             programs like bgpd(8).  Thus isakmpd only takes care of the SA

     -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.  It's possible to specify this argument 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
                   10  FIFO user interface
                   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 speak, 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.

     -K      When this option is given, isakmpd does not read the policy con-
             figuration file and no keynote(4) policy check is accomplished.
             This option can be used when policies for flows and SA establish-
             ment are arranged by other programs like ipsecadm(8) or bgpd(8).

     -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 receiving.  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.

     -v      Enables verbose logging.  Normally, isakmpd is silent and outputs
             only messages when a warning or an error occurs.  With verbose
             logging isakmpd reports successful completion of phase 1 (Main
             and Aggressive) and phase 2 (Quick) exchanges (Information and
             Transaction exchanges do not generate any additional status in-

   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 set one
     up.  In the former case, what is needed to be done varies depending on
     the actual Certificate Authority used, and is therefore not covered here,
     other than mentioning that openssl(1) needs to be used to create a cer-
     tificate signing request that the CA understands.  The latter case, how-
     ever, 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 then asked to enter information that will be incorporated
          into your certificate request.  What you are about to enter is what
          is called a Distinguished Name (DN).  There are quite a few fields
          but you can leave some blank.  For some fields there will be a de-
          fault 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 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/

          Now take these certificate signing requests to your CA and process
          them like below.  You have to add a subjectAltName extension field
          to the certificate in order to make it usable by isakmpd.  There are
          two possible ways to add the extensions to the certificate.  Either
          you have to run certpatch(8) or you have to make use of an OpenSSL
          configuration file, for example /etc/ssl/x509v3.cnf.  Replace
 with the IP-address which isakmpd will use as the certifi-
          cate identity.

          To use certpatch(8), do the following

          # openssl x509 -req -days 365 -in -CA /etc/ssl/ca.crt \
                  -CAkey /etc/ssl/private/ca.key -CAcreateserial \
          # certpatch -i -k /etc/ssl/private/ca.key \

          Otherwise do

          # setenv CERTIP
          # openssl x509 -req -days 365 -in -CA /etc/ssl/ca.crt \
                  -CAkey /etc/ssl/private/ca.key -CAcreateserial \
                  -extfile /etc/ssl/x509v3.cnf -extensions x509v3_IPAddr \

          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

          or with certpatch(8)

          # certpatch -t fqdn -i somehost.somedomain \
                  -k /etc/ssl/private/ca.key \
                  somehost.somedomain.crt somehost.somedomain.crt

          (This assumes the previous steps were used to create a request for
          somehost.somedomain instead of

          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/.

     To revoke certificates, create a Certificate Revocation List (CRL) file
     and install it in the /etc/isakmpd/crls/ directory.  See openssl(1) and
     the `crl' subcommand for more info.

     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/userATfoo.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 <&lt;name>&gt;
             Start the named connection, if stopped or inactive.

     C set [section]:tag=value
     C set [section]:tag=value force
     C add [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.  `set' will fail if the configuration already contains a
             section with the named tag; use the `force' option to change this
             behaviour.  `add' appends a configuration value to the named con-
             figuration list tag.  `rm' removes a tag in a section.  `rms' re-
             moves an entire section.

             NOTE: Sending isakmpd a SIGHUP or an "R" through the FIFO will
             void any updates done to the configuration.

     C get [section]:tag
             Get the configuration value of the specified section and tag.
             The result is stored in /var/run/isakmpd.result.

     d <&lt;cookies>&gt; <&lt;msgid>&gt;
             Delete the specified SA from the system.  Specify <msgid> as "-"
             to match a Phase 1 SA.

     D <&lt;class>&gt; <&lt;level>&gt;
     D A <&lt;level>&gt;
     D T     Set debug class <class> to level <level>.  If <class> is speci-
             fied as "A", the level applies to all debug classes.  "D T" tog-
             gles all debug classes to level zero.  Another "D T" command will
             toggle them back to the earlier levels.

     p on[=<&lt;path>&gt;]
     p off   Enable or disable cleartext IKE packet capture.  When enabling,
             optionally specify which file isakmpd should capture the packets

     Q       Cleanly shutdown 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.result file.

     t <&lt;name>&gt;
             Tear down the named connection, if active.

     T       Tear down all active connections.

     /etc/isakmpd/ca/             The directory where CA certificates can be

     /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/crls/           The directory where CRLs can be found.

     /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

     /etc/isakmpd/isakmpd.policy  The keynote policy configuration file.  The
                                  same mode requirements as isakmpd.conf.

                                  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 in the
                                  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-

     /var/run/isakmpd.result      The report file written when the `S' or `C
                                  get' command is issued in the command FIFO.

     /usr/share/ipsec/isakmpd/    A directory containing some sample isakmpd
                                  and keynote policy configuration files.

     openssl(1), getnameinfo(3), pcap(3), ipsec(4), isakmpd.conf(5),
     isakmpd.policy(5), ssl(8), tcpdump(8), vpn(8)

     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.

     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.  The privileged pro-
     cess only allows binding to the default port 500 or unprivileged ports
     (>1024).  It is not possible to change the interfaces isakmpd listens on
     without a restart.

     The -P flag does not do what we document, rather it does nothing.

OpenBSD 3.6                     August 07, 2002                              6