Provided by: isakmpd_20041012-7.2ubuntu1_amd64 bug


     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 configuration as well as a
     policy database which describes what kinds of SAs to negotiate, and by listening for
     different events that trigger these negotiations.  The events that control isakmpd consist
     of negotiation initiations 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 triggered by timers
     running out.

     Most uses of isakmpd will be to implement so called "virtual private networks" 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 below.

     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 IPv6.

     -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 establishment.

     -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 running 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 debugging 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

     -i pid-file
             By default the PID of the daemon process will be written to /var/run/
             This path can be overridden by specifying another one as the argument to the -i

     -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 configuration file and
             no keynote(4) policy check is accomplished.  This option can be used when policies
             for flows and SA establishment are arranged by other programs like ipsecadm(8) or

     -L      Enable IKE packet capture.  When this option is given, isakmpd will capture to file
             an unencrypted copy of the negotiation packets 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 internally.  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/, 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

   Setting up an IKE public key infrastructure (a.k.a. PKI)
     In order to use public key based authentication, there has to be an infrastructure managing
     the key signing.  Either there is an already existing 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 certificate signing request
     that the CA understands.  The latter case, however, 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 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 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 recommended, as it should be

          # 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 certificate 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

     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/

     For UFQDN identities  /etc/isakmpd/pubkeys/ufqdn/

   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 command-specific options.  Available
     commands are:

     c <name>
             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
             configuration list tag.  ‘rm’ removes a tag in a section.  ‘rms’ removes an entire

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

     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 toggle 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 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 <name>
             Tear down the named connection, if active.

     T       Tear down all active connections.


     /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/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 isakmpd.

     /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 certificate for this key in the certificate
                                  directory mentioned above.  The same mode requirements as

     /etc/isakmpd/pubkeys/        Directory in which trusted public keys can be kept.  The keys
                                  must be named in the fashion described above.

     /var/run/         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/      The report file written when SIGUSR1 is received.

     /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 process 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.