path: root/sbin/isakmpd/isakmpd.8

.\" $OpenBSD: isakmpd.8,v 1.67 2005/02/25 14:14:31 hshoexer Exp $
.\" $EOM: isakmpd.8,v 1.23 2000/05/02 00:30:23 niklas Exp $
.\"
.\" Copyright (c) 1998, 1999, 2000, 2001 Niklas Hallqvist.
.\" All rights reserved.
.\" Copyright (c) 1999 Angelos D. Keromytis.  All rights reserved.
.\" Copyright (c) 2001, 2002 Håkan Olsson.  All rights reserved.
.\"
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.\" modification, are permitted provided that the following conditions
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.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
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.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
.\" IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\" This code was written under funding by Ericsson Radio Systems.
.\"
.\" Manual page, using -mandoc macros
.\"
.Dd August 07, 2002
.Dt ISAKMPD 8
.Os
.Sh NAME
.Nm isakmpd
.Nd ISAKMP/Oakley a.k.a. IKE key management daemon
.Sh SYNOPSIS
.Nm isakmpd
.Bk -words
.Op Fl 4
.Op Fl 6
.Op Fl c Ar config-file
.Op Fl a
.Op Fl d
.Op Fl D Ar class=level
.Op Fl f Ar fifo
.Op Fl i Ar pid-file
.Op Fl n
.Op Fl N Ar udpencap-port
.Op Fl p Ar listen-port
.Op Fl K
.Op Fl L
.Op Fl l Ar packetlog-file
.Op Fl r Ar seed
.Op Fl R Ar report-file
.Op Fl v
.Ek
.Sh DESCRIPTION
The
.Nm
daemon establishes security associations for encrypted
and/or authenticated network traffic.
At this moment, and probably forever, this means
.Xr ipsec 4
traffic.
.Pp
The way
.Nm
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
.Nm
consist of negotiation initiations from a remote party, user input via
a FIFO or by signals, upcalls from the kernel via a
.Dv PF_KEY
socket, and lastly by scheduled events triggered by timers running out.
.Pp
Most uses of
.Nm
will be to implement so called "virtual private
networks" or VPNs for short.
The
.Xr vpn 8
manual page describes how to set up
.Nm
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.
.Pp
On startup
.Nm
forks into two processes for privilege separation.
The unprivileged child jails itself with
.Xr chroot 8
to
.Pa /var/empty .
The privileged process communicates with the child, reads configuration files
and PKI information and binds to privileged ports on its behalf.
See
.Sx CAVEATS
section below.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl 4 | Fl 6
These options control what address family
.Pf ( Dv AF_INET
and/or
.Dv AF_INET6 )
.Nm
will use.
The default is to use both IPv4 and IPv6.
.It Fl a
If given,
.Nm
does not set up flows automatically.
This is useful when flows are configured with
.Xr ipsecadm 4
or by other programs like
.Xr bgpd 8 .
Thus
.Nm
only takes care of the SA establishment.
.It Fl c Ar config-file
If given, the
.Fl c
option specifies an alternate configuration file instead of
.Pa /etc/isakmpd/isakmpd.conf .
As this file may contain sensitive information, it must be readable
only by the user running the daemon.
.Nm
will reread the configuration file when sent a
.Dv SIGHUP
signal.
.It Fl d
The
.Fl d
option is used to make the daemon run in the foreground, logging to stderr.
.It Xo Fl D
.Ar class Ns = Ns Ar level
.Xc
Debugging class.
It's possible to specify this argument many times.
It takes a parameter of the form
.Ar class Ns = Ns Ar level ,
where both
.Ar class
and
.Ar level
are numbers.
.Ar class
denotes a debugging class, and
.Ar 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
.Ar class
is set to
.Sq A ,
then all debugging classes are set to the specified level.
.Pp
Valid values for
.Ar class
are as follows:
.Pp
.Bl -tag -width 2n -compact -offset indent
.It 0
Misc
.It 1
Transport
.It 2
Message
.It 3
Crypto
.It 4
Timer
.It 5
Sysdep
.It 6
SA
.It 7
Exchange
.It 8
Negotiation
.It 9
Policy
.It 10
FIFO user interface
.It A
All
.El
.Pp
Currently used values for
.Ar level
are 0 to 99.
.It Fl f Ar fifo
The
.Fl f
option specifies the
.Tn FIFO
(a.k.a. named pipe) where the daemon listens for
user requests.
If the path given is a dash
.Pq Sq \&- ,
.Nm
will listen to stdin instead.
.It Fl i Ar pid-file
By default the PID of the daemon process will be written to
.Pa /var/run/isakmpd.pid .
This path can be overridden by specifying another one as the argument to the
.Fl i
option.
.It Fl n
When the
.Fl 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.
.It Fl N Ar udpencap-port
The
.Fl N
option specifies the listen port for encapsulated udp the daemon will bind to.
.It Fl p Ar listen-port
The
.Fl p
option specifies the listen port the daemon will bind to.
.It Fl K
When this option is given,
.Nm
does not read the policy configuration file and no
.Xr keynote 4
policy check is accomplished.
This option can be used when policies for flows and SA establishment are
arranged by other programs like
.Xr ipsecadm 8
or
.Xr bgpd 8 .
.It Fl L
Enable IKE packet capture.
When this option is given,
.Nm
will capture to file an unencrypted copy of the negotiation packets it
is sending and receiving.
This file can later be read by
.Xr tcpdump 8
and other utilities using
.Xr pcap 3 .
.It Fl l Ar packetlog-file
As option
.Fl L
above, but capture to a specified file.
.It Fl r Ar seed
If given, a deterministic random number sequence will be used internally.
This is useful for setting up regression tests.
.It Fl R Ar report-file
When you signal
.Nm
a
.Dv SIGUSR1 ,
it will report its internal state to a report file, normally
.Pa /var/run/isakmpd.report ,
but this can be changed by feeding
the file name as an argument to the
.Fl R
flag.
.It Fl v
Enables verbose logging.
Normally,
.Nm
is silent and outputs only messages when a warning or an error occurs.
With verbose logging
.Nm
reports successful completion of phase 1 (Main and Aggressive) and phase 2
(Quick) exchanges (Information and Transaction exchanges do not generate any
additional status information).
.El
.Ss 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
.Nm
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
.Xr openssl 1
needs to be used to create a certificate signing request that the
CA understands.
The latter case, however, is described here:
.Bl -enum
.It
Create your own CA as root.
.Bd -literal
# openssl genrsa -out /etc/ssl/private/ca.key 1024
# openssl req -new -key /etc/ssl/private/ca.key \e
	-out /etc/ssl/private/ca.csr
.Ed
.Pp
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
.Sq \&. ,
the field will be left blank.
.Bd -literal
# openssl x509 -req -days 365 -in /etc/ssl/private/ca.csr \e
	-signkey /etc/ssl/private/ca.key \e
	-extfile /etc/ssl/x509v3.cnf -extensions x509v3_CA \e
	-out /etc/ssl/ca.crt
.Ed
.Pp
.It
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 recommended, as it should be unique.
.Bd -literal
# openssl genrsa -out /etc/isakmpd/private/local.key 1024
# openssl req -new -key /etc/isakmpd/private/local.key \e
	-out /etc/isakmpd/private/10.0.0.1.csr
.Ed
.Pp
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
.Nm isakmpd .
There are two possible ways to add the extensions to the certificate.
Either you have to run
.Xr certpatch 8
or you have to make use of an OpenSSL configuration file, for example
.Pa /etc/ssl/x509v3.cnf .
Replace 10.0.0.1 with the IP-address which
.Nm
will use as the certificate identity.
.Pp
To use
.Xr certpatch 8 ,
do the following
.Bd -literal
# openssl x509 -req -days 365 -in 10.0.0.1.csr -CA /etc/ssl/ca.crt \e
	-CAkey /etc/ssl/private/ca.key -CAcreateserial \e
	-out 10.0.0.1.crt
# certpatch -i 10.0.0.1 -k /etc/ssl/private/ca.key \e
	10.0.0.1.crt 10.0.0.1.crt
.Ed
.Pp
Otherwise do
.Bd -literal
# setenv CERTIP 10.0.0.1
# openssl x509 -req -days 365 -in 10.0.0.1.csr -CA /etc/ssl/ca.crt \e
	-CAkey /etc/ssl/private/ca.key -CAcreateserial \e
	-extfile /etc/ssl/x509v3.cnf -extensions x509v3_IPAddr \e
	-out 10.0.0.1.crt
.Ed
.Pp
For a FQDN certificate, do
.Bd -literal
# setenv CERTFQDN somehost.somedomain
# openssl x509 -req -days 365 -in somehost.somedomain.csr \e
	-CA /etc/ssl/ca.crt -CAkey /etc/ssl/private/ca.key \e
	-CAcreateserial \e
	-extfile /etc/ssl/x509v3.cnf -extensions x509v3_FQDN \e
	-out somehost.somedomain.crt
.Ed
.Pp
or with
.Xr certpatch 8
.Bd -literal
# certpatch -t fqdn -i somehost.somedomain \e
	-k /etc/ssl/private/ca.key \e
	somehost.somedomain.crt somehost.somedomain.crt
.Ed
.Pp
(This assumes the previous steps were used to create a request for
somehost.somedomain instead of 10.0.0.1)
.Pp
Put the certificate (the file ending in .crt) in
.Pa /etc/isakmpd/certs/
on your local system.
Also carry over the CA cert
.Pa /etc/ssl/ca.crt
and put it in
.Pa /etc/isakmpd/ca/ .
.El
.Pp
To revoke certificates, create a Certificate Revocation List (CRL) file
and install it in the
.Pa /etc/isakmpd/crls/
directory.
See
.Xr openssl 1
and the
.Sq crl
subcommand for more info.
.Pp
It is also possible to store trusted public keys to make them directly
usable by
.Nm isakmpd .
The keys should be saved in PEM format (see
.Xr openssl 1 )
and named and stored after this easy formula:
.Bl -tag -width for_ufqdn_identities
.It For IPv4 identities
/etc/isakmpd/pubkeys/ipv4/A.B.C.D
.It For IPv6 identities
/etc/isakmpd/pubkeys/ipv6/abcd:abcd::ab:bc
.It For FQDN identities
/etc/isakmpd/pubkeys/fqdn/foo.bar.org
.It For UFQDN identities
/etc/isakmpd/pubkeys/ufqdn/user@foo.bar.org
.El
.Ss The FIFO user interface
When
.Nm
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:
.Bl -tag -width Ds -compact
.Pp
.It Ic "c <name>"
Start the named connection, if stopped or inactive.
.Pp
.It Ic "C set [section]:tag=value"
.It Ic "C set [section]:tag=value force"
.It Ic "C add [section]:tag=value"
.It Ic "C rm  [section]:tag"
.It Ic "C rms [section]"
Update the running
.Nm
configuration atomically.
.Sq set
sets a configuration value consisting of a section, tag and value triplet.
.Sq set
will fail if the configuration already contains a section with the named tag;
use the
.Sq force
option to change this behaviour.
.Sq add
appends a configuration value to the named configuration list tag.
.Sq rm
removes a tag in a section.
.Sq rms
removes an entire section.
.Pp
NOTE: Sending isakmpd a SIGHUP or an "R" through the FIFO will
void any updates done to the configuration.
.Pp
.It Ic "C get [section]:tag"
Get the configuration value of the specified section and tag.
The result is stored in
.Pa /var/run/isakmpd.result .
.Pp
.It Ic "d <cookies> <msgid>"
Delete the specified SA from the system.
Specify <msgid> as "-" to match a Phase 1 SA.
.Pp
.It Ic "D <class> <level>"
.It Ic "D A <level>"
.It Ic "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.
.Pp
.It Ic "p on[=<path>]"
.It Ic "p off"
Enable or disable cleartext IKE packet capture.
When enabling, optionally specify which file
.Nm
should capture the packets to.
.Pp
.It Ic "Q"
Cleanly shutdown the daemon, as when sent a
.Dv SIGTERM
signal.
.Pp
.It Ic "r"
Report
.Nm
internal state to a file.
See
.Fl R
option.
Same as when sent a
.Dv SIGUSR1
signal.
.Pp
.It Ic "R"
Reinitialize
.Nm isakmpd ,
as when sent a
.Dv SIGHUP
signal.
.Pp
.It Ic "S"
Report information on all known SAs to the
.Pa /var/run/isakmpd.result
file.
.Pp
.It Ic "t <name>"
Tear down the named connection, if active.
.Pp
.It Ic "T"
Tear down all active connections.
.El
.Sh FILES
.Bl -tag -width /etc/isakmpd/private/local.
.It Pa /etc/isakmpd/ca/
The directory where CA certificates can be found.
.It Pa /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.
.It Pa /etc/isakmpd/crls/
The directory where CRLs can be found.
.It Pa /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
.Nm isakmpd .
.It Pa /etc/isakmpd/isakmpd.policy
The keynote policy configuration file.
The same mode requirements as
.Nm isakmpd.conf .
.It Pa /etc/isakmpd/private/local.key
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
.Nm isakmpd.conf .
.It Pa /etc/isakmpd/pubkeys/
Directory in which trusted public keys can be kept.
The keys must be named in the fashion described above.
.It Pa /var/run/isakmpd.pid
The PID of the current daemon.
.It Pa /var/run/isakmpd.fifo
The FIFO used to manually control
.Nm isakmpd .
.It Pa /var/run/isakmpd.pcap
The default IKE packet capture file.
.It Pa /var/run/isakmpd.report
The report file written when
.Dv SIGUSR1
is received.
.It Pa /var/run/isakmpd.result
The report file written when the
.Sq S
or
.Sq "C get"
command is issued in the command FIFO.
.It Pa /usr/share/ipsec/isakmpd/
A directory containing some sample
.Nm
and keynote policy configuration files.
.El
.Sh SEE ALSO
.Xr openssl 1 ,
.Xr getnameinfo 3 ,
.Xr pcap 3 ,
.Xr ipsec 4 ,
.Xr isakmpd.conf 5 ,
.Xr isakmpd.policy 5 ,
.Xr ssl 8 ,
.Xr tcpdump 8 ,
.Xr vpn 8
.Sh HISTORY
The ISAKMP/Oakley key management protocol is described in the RFCs
.%T RFC 2407 ,
.%T RFC 2408
and
.%T RFC 2409 .
This implementation was done 1998 by Niklas Hallqvist and Niels Provos,
sponsored by Ericsson Radio Systems.
.Sh CAVEATS
When storing a trusted public key for an IPv6 identity, the
.Em most efficient
form of address representation, i.e "::" instead of ":0:0:0:",
must be used or the matching will fail.
.Nm
uses the output from
.Xr 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
.Nm
listens on without a restart.