.\"	$KAME: setkey.8,v 1.89 2003/09/07 22:17:41 itojun Exp $
.\"
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.Dd August 25, 2024
.Dt SETKEY 8
.Os
.\"
.Sh NAME
.Nm setkey
.Nd "manually manipulate the IPsec SA/SP database"
.\"
.Sh SYNOPSIS
.Nm
.Op Fl v
.Fl c
.Nm
.Op Fl v
.Fl f Ar filename
.Nm
.Op Fl v
.Fl e Ar script
.Nm
.Op Fl Pgltv
.Fl D
.Nm
.Op Fl Pv
.Fl F
.Nm
.Op Fl h
.Fl x
.\"
.Sh DESCRIPTION
The
.Nm
utility adds, updates, dumps, or flushes
Security Association Database (SAD) entries
as well as Security Policy Database (SPD) entries in the kernel.
.Pp
The
.Nm
utility takes a series of operations from the standard input
(if invoked with
.Fl c ) ,
from the file named
.Ar filename
(if invoked with
.Fl f Ar filename ) ,
or from the command line argument following the option
(if invoked with
.Fl e Ar script ) .
.Bl -tag -width indent
.It Fl D
Dump the SAD entries.
If with
.Fl P ,
the SPD entries are dumped.
.It Fl F
Flush the SAD entries.
If with
.Fl P ,
the SPD entries are flushed.
.It Fl g
Only SPD entries with global scope are dumped with
.Fl D
and
.Fl P
flags.
.It Fl t
Only SPD entries with ifnet scope are dumped with
.Fl D
and
.Fl P
flags.
Such SPD entries are linked to the corresponding
.Xr if_ipsec 4
virtual tunneling interface.
.It Fl h
Add hexadecimal dump on
.Fl x
mode.
.It Fl l
Loop forever with short output on
.Fl D .
.It Fl v
Be verbose.
The program will dump messages exchanged on
.Dv PF_KEY
socket, including messages sent from other processes to the kernel.
.It Fl x
Loop forever and dump all the messages transmitted to
.Dv PF_KEY
socket.
.Fl xx
makes each timestamp unformatted.
.El
.Ss Configuration syntax
With
.Fl c
or
.Fl f
on the command line,
.Nm
accepts the following configuration syntax.
Lines starting with hash signs
.Pq Ql #
are treated as comment lines.
.Bl -tag -width indent
.It Xo
.Li add
.Op Fl 46n
.Ar src Ar dst Ar protocol Ar spi
.Op Ar extensions
.Ar algorithm ...
.Li \&;
.Xc
Add an SAD entry.
.Li add
can fail with multiple reasons,
including when the key length does not match the specified algorithm.
.\"
.It Xo
.Li get
.Op Fl 46n
.Ar src Ar dst Ar protocol Ar spi
.Li \&;
.Xc
Show an SAD entry.
.\"
.It Xo
.Li delete
.Op Fl 46n
.Ar src Ar dst Ar protocol Ar spi
.Li \&;
.Xc
Remove an SAD entry.
.\"
.It Xo
.Li deleteall
.Op Fl 46n
.Ar src Ar dst Ar protocol
.Li \&;
.Xc
Remove all SAD entries that match the specification.
.\"
.It Xo
.Li flush
.Op Ar protocol
.Li \&;
.Xc
Clear all SAD entries matched by the options.
.Fl F
on the command line achieves the same functionality.
.\"
.It Xo
.Li dump
.Op Ar protocol
.Li \&;
.Xc
Dumps all SAD entries matched by the options.
.Fl D
on the command line achieves the same functionality.
.\"
.It Xo
.Li spdadd
.Op Fl 46n
.Ar src_range Ar dst_range Ar upperspec Ar policy
.Li \&;
.Xc
Add an SPD entry.
.\"
.It Xo
.Li spddelete
.Op Fl 46n
.Ar src_range Ar dst_range Ar upperspec Fl P Ar direction
.Li \&;
.Xc
Delete an SPD entry.
.\"
.It Xo
.Li spdflush
.Li \&;
.Xc
Clear all SPD entries.
.Fl FP
on the command line achieves the same functionality.
.\"
.It Xo
.Li spddump
.Li \&;
.Xc
Dumps all SPD entries.
.Fl DP
on the command line achieves the same functionality.
.El
.\"
.Pp
Meta-arguments are as follows:
.Pp
.Bl -tag -compact -width indent
.It Ar src
.It Ar dst
Source/destination of the secure communication is specified as
IPv4/v6 address.
The
.Nm
utility
can resolve an FQDN into numeric addresses.
If the FQDN resolves into multiple addresses,
.Nm
will install multiple SAD/SPD entries into the kernel
by trying all possible combinations.
.Fl 4 ,
.Fl 6
and
.Fl n
restricts the address resolution of FQDN in certain ways.
.Fl 4
and
.Fl 6
restrict results into IPv4/v6 addresses only, respectively.
.Fl n
avoids FQDN resolution and requires addresses to be numeric addresses.
.\"
.Pp
.It Ar protocol
.Ar protocol
is one of following:
.Bl -tag -width Fl -compact
.It Li esp
ESP based on rfc2406
.It Li esp-old
ESP based on rfc1827
.It Li ah
AH based on rfc2402
.It Li ah-old
AH based on rfc1826
.It Li ipcomp
IPComp
.It Li tcp
TCP-MD5 based on rfc2385
.El
.\"
.Pp
.It Ar spi
Security Parameter Index
(SPI)
for the SAD and the SPD.
.Ar spi
must be a decimal number, or a hexadecimal number with
.Ql 0x
prefix.
SPI values between 0 and 255 are reserved for future use by IANA
and they cannot be used.
.\"
.Pp
.It Ar extensions
take some of the following:
.Bl -tag -width Fl natt_mtu -compact
.\"
.It Fl m Ar mode
Specify a security protocol mode for use.
.Ar mode
is one of following:
.Li transport , tunnel
or
.Li any .
The default value is
.Li any .
.\"
.It Fl r Ar size
Specify the bitmap size in octets of the anti-replay window.
.Ar size
is a 32-bit unsigned integer, and its value is one eighth of the
anti-replay window size in packets.
If
.Ar size
is zero or not specified, an anti-replay check does not take place.
.\"
.It Fl u Ar id
Specify the identifier of the policy entry in SPD.
See
.Ar policy .
.\"
.It Fl f Ar pad_option
defines the content of the ESP padding.
.Ar pad_option
is one of following:
.Bl -tag -width random-pad -compact
.It Li zero-pad
All of the padding are zero.
.It Li random-pad
A series of randomized values are set.
.It Li seq-pad
A series of sequential increasing numbers started from 1 are set.
.El
.\"
.It Fl f Li nocyclic-seq
Do not allow cyclic sequence number.
.\"
.It Fl lh Ar time
.It Fl ls Ar time
Specify hard/soft life time duration of the SA.
.It Fl natt Ar oai \([ Ar sport \(] Ar oar \([ Ar dport \(]
Manually configure NAT-T for the SA, by specifying initiator
.Ar oai
and
requestor
.Ar oar
ip addresses and ports.
Note that the
.Sq \([
and
.Sq \(]
symbols are part of the syntax for the ports specification,
not indication of the optional components.
.It Fl natt_mtu Ar fragsize
Configure NAT-T fragment size.
.It Fl esn
Enable Extended Sequence Number extension for this SA.
.It Fl hwif Ar ifname
Request hardware offload to the specified interface
.Ar ifname
(only).
By default offload occurs to all capable interfaces.
.El
.\"
.Pp
.It Ar algorithm
.Bl -tag -width Fl -compact
.It Fl E Ar ealgo Ar key
Specify an encryption or Authenticated Encryption with Associated Data
(AEAD) algorithm
.Ar ealgo
for ESP.
.It Xo
.Fl E Ar ealgo Ar key
.Fl A Ar aalgo Ar key
.Xc
Specify a encryption algorithm
.Ar ealgo ,
as well as a payload authentication algorithm
.Ar aalgo ,
for ESP.
.It Fl A Ar aalgo Ar key
Specify an authentication algorithm for AH.
.It Fl C Ar calgo Op Fl R
Specify a compression algorithm for IPComp.
If
.Fl R
is specified, the
.Ar spi
field value will be used as the IPComp CPI
(compression parameter index)
on wire as is.
If
.Fl R
is not specified,
the kernel will use well-known CPI on wire, and
.Ar spi
field will be used only as an index for kernel internal usage.
.El
.Pp
.Ar key
must be double-quoted character string, or a series of hexadecimal digits
preceded by
.Ql 0x .
.Pp
Possible values for
.Ar ealgo ,
.Ar aalgo
and
.Ar calgo
are specified in separate section.
.\"
.Pp
.It Ar src_range
.It Ar dst_range
These are selections of the secure communication specified as
IPv4/v6 address or IPv4/v6 address range, and it may accompany
TCP/UDP port specification.
This takes the following form:
.Bd -unfilled
.Ar address
.Ar address/prefixlen
.Ar address[port]
.Ar address/prefixlen[port]
.Ed
.Pp
.Ar prefixlen
and
.Ar port
must be a decimal number.
The square brackets around
.Ar port
are necessary and are not manpage metacharacters.
For FQDN resolution, the rules applicable to
.Ar src
and
.Ar dst
apply here as well.
.\"
.Pp
.It Ar upperspec
The upper layer protocol to be used.
You can use one of the words in
.Pa /etc/protocols
as
.Ar upperspec ,
as well as
.Li icmp6 ,
.Li ip4 ,
or
.Li any .
The word
.Li any
stands for
.Dq any protocol .
The protocol number may also be used to specify the
.Ar upperspec .
A type and code related to ICMPv6 may also be specified as an
.Ar upperspec .
The type is specified first, followed by a comma and then the relevant
code.
The specification must be placed after
.Li icmp6 .
The kernel considers a zero to be a wildcard but
cannot distinguish between a wildcard and an ICMPv6
type which is zero.
The following example shows a policy where IPSec is not required for
inbound Neighbor Solicitations:
.Pp
.Dl "spdadd ::/0 ::/0 icmp6 135,0 -P in none;"
.Pp
NOTE:
.Ar upperspec
does not work in the forwarding case at this moment,
as it requires extra reassembly at forwarding node,
which is not implemented at this moment.
Although there are many protocols in
.Pa /etc/protocols ,
protocols other than TCP, UDP and ICMP may not be suitable to use with IPsec.
.\"
.Pp
.It Ar policy
.Ar policy
is expressed in one of the following three formats:
.Pp
.Bl -tag -width 2n -compact
.It Fl P Ar direction Li discard
.It Fl P Ar direction Li none
.It Xo Fl P Ar direction Li ipsec
.Ar protocol/mode/src-dst/level Op ...
.Xc
.El
.Pp
.Bl -tag -compact -width "policy level"
.It Ar direction
The
.Ar direction
of a policy must be specified as one of:
.Li out
or
.Li in .
.It Ar policy level
The direction is followed by one of the following policy levels:
.Li discard ,
.Li none ,
or
.Li ipsec .
.Bl -compact -bullet
.It
The
.Li discard
policy level means that packets matching the supplied indices will
be discarded.
.It
The
.Li none
policy level means that IPsec operations will not take place on
the packet.
.It
The
.Li ipsec
policy level means that IPsec operation will take place onto
the packet.
.El
.It Ar protocol/mode/src-dst/level
The
.Ar protocol/mode/src-dst/level
statement gives the rule for how to process the packet.
.Bl -compact -bullet
.It
The
.Ar protocol
is specified as
.Li ah ,
.Li esp
or
.Li ipcomp .
.It
The
.Ar mode
is either
.Li transport
or
.Li tunnel .
.El
.Pp
If
.Ar mode
is
.Li tunnel ,
you must specify the end-point addresses of the SA as
.Ar src
and
.Ar dst
with a dash,
.Sq - ,
between the addresses.
.Pp
If
.Ar mode
is
.Li transport ,
both
.Ar src
and
.Ar dst
can be omitted.
.Pp
The
.Ar level
is one of the following:
.Li default , use , require
or
.Li unique .
If the SA is not available in every level, the kernel will request
the SA from the key exchange daemon.
.Pp
.Bl -compact -bullet
.It
A value of
.Li default
tells the kernel to use the system wide default protocol
e.g.,\& the one from the
.Li esp_trans_deflev
sysctl variable, when the kernel processes the packet.
.It
A value of
.Li use
means that the kernel will use an SA if it is available,
otherwise the kernel will pass the packet as it would normally.
.It
A value of
.Li require
means that an SA is required whenever the kernel sends a packet matched
that matches the policy.
.It
The
.Li unique
level is the same as
.Li require
but, in addition, it allows the policy to bind with the unique out-bound SA.
.Pp
For example, if you specify the policy level
.Li unique ,
.Xr racoon 8 Pq Pa ports/security/ipsec-tools
will configure the SA for the policy.
If you configure the SA by manual keying for that policy,
you can put the decimal number as the policy identifier after
.Li unique
separated by colon
.Ql :\&
as in the following example:
.Li unique:number .
In order to bind this policy to the SA,
.Li number
must be between 1 and 32767,
which corresponds to
.Ar extensions Fl u
of manual SA configuration.
.El
.El
.Pp
When you want to use an SA bundle, you can define multiple rules.
For
example, if an IP header was followed by an AH header followed by an
ESP header followed by an upper layer protocol header, the rule would
be:
.Pp
.Dl esp/transport//require ah/transport//require ;
.Pp
The rule order is very important.
.Pp
Note that
.Dq Li discard
and
.Dq Li none
are not in the syntax described in
.Xr ipsec_set_policy 3 .
There are small, but important, differences in the syntax.
See
.Xr ipsec_set_policy 3
for details.
.El
.\"
.Sh ALGORITHMS
The following lists show the supported algorithms.
.Ss Authentication Algorithms
The following authentication algorithms can be used as
.Ar aalgo
in the
.Fl A Ar aalgo
of the
.Ar protocol
parameter:
.Bd -literal -offset indent
algorithm	keylen (bits)	comment
hmac-sha1	160		ah/esp: rfc2404
		160		ah-old/esp-old: 128bit ICV (no document)
null		0 to 2048	for debugging
hmac-sha2-256	256		ah/esp: 128bit ICV (RFC4868)
		256		ah-old/esp-old: 128bit ICV (no document)
hmac-sha2-384	384		ah/esp: 192bit ICV (RFC4868)
		384		ah-old/esp-old: 128bit ICV (no document)
hmac-sha2-512	512		ah/esp: 256bit ICV (RFC4868)
		512		ah-old/esp-old: 128bit ICV (no document)
aes-xcbc-mac	128		ah/esp: 96bit ICV (RFC3566)
		128		ah-old/esp-old: 128bit ICV (no document)
tcp-md5		8 to 640	tcp: rfc2385
chacha20-poly1305	256	ah/esp: 128bit ICV (RFC7634)
.Ed
.Ss Encryption Algorithms
The following encryption algorithms can be used as the
.Ar ealgo
in the
.Fl E Ar ealgo
of the
.Ar protocol
parameter:
.Bd -literal -offset indent
algorithm	keylen (bits)	comment
null		0 to 2048	rfc2410
aes-cbc		128/192/256	rfc3602
aes-ctr		160/224/288	rfc3686
aes-gcm-16	160/224/288	AEAD; rfc4106
chacha20-poly1305	256	rfc7634
.Ed
.Pp
Note that the first 128/192/256 bits of a key for
.Li aes-ctr
or
.Li aes-gcm-16
will be used as the AES key,
and the remaining 32 bits will be used as the nonce.
.Pp
AEAD encryption algorithms such as
.Li aes-gcm-16
include authentication and should not be
paired with a separate authentication algorithm via
.Fl A .
.Ss Compression Algorithms
The following compression algorithms can be used
as the
.Ar calgo
in the
.Fl C Ar calgo
of the
.Ar protocol
parameter:
.Bd -literal -offset indent
algorithm	comment
deflate		rfc2394
.Ed
.\"
.Sh EXIT STATUS
.Ex -std
.\"
.Sh EXAMPLES
Add an ESP SA between two IPv6 addresses using the
AES-GCM AEAD algorithm.
.Bd -literal -offset indent
add 3ffe:501:4819::1 3ffe:501:481d::1 esp 123457
	-E aes-gcm-16 0x3ffe050148193ffe050148193ffe050148193ffe ;
.Pp
.Ed
.\"
Add an authentication SA between two FQDN specified hosts:
.Bd -literal -offset indent
add -6 myhost.example.com yourhost.example.com ah 123456
	-A hmac-sha2-256 "AH SA configuration!" ;
.Pp
.Ed
Get the SA information associated with first example above:
.Bd -literal -offset indent
get 3ffe:501:4819::1 3ffe:501:481d::1 ah 123456 ;
.Pp
.Ed
Flush all entries from the database:
.Bd -literal -offset indent
flush ;
.Pp
.Ed
Dump the ESP entries from the database:
.Bd -literal -offset indent
dump esp ;
.Pp
.Ed
Add a security policy between two networks that uses ESP in tunnel mode:
.Bd -literal -offset indent
spdadd 10.0.11.41/32[21] 10.0.11.33/32[any] any
	-P out ipsec esp/tunnel/192.168.0.1-192.168.1.2/require ;
.Pp
.Ed
Use TCP MD5 between two numerically specified hosts:
.Bd -literal -offset indent
add 10.1.10.34 10.1.10.36 tcp 0x1000 -A tcp-md5 "TCP-MD5 BGP secret" ;
add 10.1.10.36 10.1.10.34 tcp 0x1001 -A tcp-md5 "TCP-MD5 BGP secret" ;
.Ed
.\"
.Sh SEE ALSO
.Xr ipsec_set_policy 3 ,
.Xr if_ipsec 4 ,
.Xr racoon 8 Pq Pa ports/security/ipsec-tools ,
.Xr sysctl 8
.Rs
.%T "Changed manual key configuration for IPsec"
.%U https://www.kame.net/newsletter/19991007/
.%D "October 1999"
.Re
.\"
.Sh HISTORY
The
.Nm
utility first appeared in WIDE Hydrangea IPv6 protocol stack kit.
The utility was completely re-designed in June 1998.
It first appeared in
.Fx 4.0 .
.\"
.Sh BUGS
The
.Nm
utility
should report and handle syntax errors better.
.Pp
For IPsec gateway configuration,
.Ar src_range
and
.Ar dst_range
with TCP/UDP port number do not work, as the gateway does not reassemble
packets
(cannot inspect upper-layer headers).