src/setkey/setkey.8

.\"	$NetBSD: setkey.8,v 1.34 2012/02/18 13:51:29 wiz Exp $
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.Dd February 18, 2012
.Dt SETKEY 8
.Os
.\"
.Sh NAME
.Nm setkey
.Nd manually manipulate the IPsec SA/SP database
.\"
.Sh SYNOPSIS
.Nm setkey
.Op Fl knrv
.Ar file ...
.Nm setkey
.Op Fl knrv
.Fl c
.Nm setkey
.Op Fl krv
.Fl f Ar filename
.Nm setkey
.Op Fl aklPrv
.Fl D
.Nm setkey
.Op Fl Pvp
.Fl F
.Nm setkey
.Op Fl H
.Fl x
.Nm setkey
.Op Fl ?V
.\"
.Sh DESCRIPTION
.Nm
adds, updates, dumps, or flushes
Security Association Database (SAD) entries
as well as Security Policy Database (SPD) entries in the kernel.
.Pp
.Nm
takes a series of operations from standard input
.Po
if invoked with
.Fl c
.Pc
or the file named
.Ar filename
.Po
if invoked with
.Fl f Ar filename
.Pc .
.Bl -tag -width Ds
.It (no flag)
Dump the SAD entries or SPD entries contained in the specified
.Ar file .
.It Fl ?
Print short help.
.It Fl a
.Nm
usually does not display dead SAD entries with
.Fl D .
If
.Fl a
is also specified, the dead SAD entries will be displayed as well.
A dead SAD entry is one that has expired but remains in the
system because it is referenced by some SPD entries.
.It Fl D
Dump the SAD entries.
If
.Fl P
is also specified, the SPD entries are dumped.
If
.Fl p
is specified, the ports are displayed.
.It Fl F
Flush the SAD entries.
If
.Fl P
is also specified, the SPD entries are flushed.
.It Fl H
Add hexadecimal dump in
.Fl x
mode.
.It Fl h
On
.Nx ,
synonym for
.Fl H .
On other systems, synonym for
.Fl ? .
.It Fl k
Use semantics used in kernel.
Available only in Linux.
See also
.Fl r .
.It Fl l
Loop forever with short output on
.Fl D .
.It Fl n
No action.
The program will check validity of the input, but no changes to
the SPD will be made.
.It Fl r
Use semantics described in IPsec RFCs.
This mode is default.
For details see section
.Sx RFC vs Linux kernel semantics .
Available only in Linux.
See also
.Fl k .
.It Fl x
Loop forever and dump all the messages transmitted to the
.Dv PF_KEY
socket.
.Fl xx
prints the unformatted timestamps.
.It Fl V
Print version string.
.It Fl v
Be verbose.
The program will dump messages exchanged on the
.Dv PF_KEY
socket, including messages sent from other processes to the kernel.
.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 Sq #
are treated as comment lines.
.Bl -tag -width Ds
.It Li add Oo Fl 46n Oc Ar src Ar dst Ar protocol Ar spi \
Oo Ar extensions Oc Ar algorithm ... Li ;
Add an SAD entry.
.Li add
can fail for multiple reasons, including when the key length does
not match the specified algorithm.
.\"
.It Li get Oo Fl 46n Oc Ar src Ar dst Ar protocol Ar spi Li ;
Show an SAD entry.
.\"
.It Li delete Oo Fl 46n Oc Ar src Ar dst Ar protocol Ar spi Li ;
Remove an SAD entry.
.\"
.It Li deleteall Oo Fl 46n Oc Ar src Ar dst Ar protocol Li ;
Remove all SAD entries that match the specification.
.\"
.It Li flush Oo Ar protocol Oc Li ;
Clear all SAD entries matched by the options.
.Fl F
on the command line achieves the same functionality.
.\"
.It Li dump Oo Ar protocol Oc Li ;
Dumps all SAD entries matched by the options.
.Fl D
on the command line achieves the same functionality.
.\"
.It Li spdadd Oo Fl 46n Oc Ar src_range Ar dst_range Ar upperspec \
Ar label Ar policy Li ;
Add an SPD entry.
.\"
.It Li spdadd tagged Ar tag Ar policy Li ;
Add an SPD entry based on a PF tag.
.Ar tag
must be a string surrounded by double quotes.
.\"
.It Li spdupdate Oo Fl 46n Oc Ar src_range Ar dst_range Ar upperspec \
Ar label Ar policy Li ;
Updates an SPD entry.
.\"
.It Li spdupdate tagged Ar tag Ar policy Li ;
Update an SPD entry based on a PF tag.
.Ar tag
must be a string surrounded by double quotes.
.\"
.It Li spddelete Oo Fl 46n Oc Ar src_range Ar dst_range Ar upperspec \
Fl P Ar direction Li ;
Delete an SPD entry.
.\"
.It Li spdflush Li ;
Clear all SPD entries.
.Fl FP
on the command line achieves the same functionality.
.\"
.It Li spddump Li ;
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 Ds
.It Ar src
.It Ar dst
Source/destination of the secure communication is specified as
an IPv4/v6 address, and an optional port number between square
brackets.
.Nm
can resolve a 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
restrict 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 esp-udp
UDP encapsulated ESP for NAT traversal (rfc3948)
.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
.Pq SPI
for the SAD and the SPD.
.Ar spi
must be a decimal number, or a hexadecimal number with a
.Dq Li 0x
prefix.
SPI values between 0 and 255 are reserved for future use by IANA
and cannot be used.
TCP-MD5 associations must use 0x1000 and therefore only have per-host
granularity at this time.
.\"
.Pp
.It Ar extensions
take some of the following:
.Bl -tag -width Fl -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 window size of bytes for replay prevention.
.Ar size
must be decimal number in 32-bit word.
If
.Ar size
is zero or not specified, replay checks don't take place.
.\"
.It Fl u Ar id
Specify the identifier of the policy entry in the 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 the paddings are zero.
.It Li random-pad
A series of randomized values are used.
.It Li seq-pad
A series of sequential increasing numbers started from 1 are used.
.El
.\"
.It Fl f Li nocyclic-seq
Don't allow cyclic sequence numbers.
.\"
.It Fl lh Ar time
.It Fl ls Ar time
Specify hard/soft life time duration of the SA measured in seconds.
.\"
.It Fl bh Ar bytes
.It Fl bs Ar bytes
Specify hard/soft life time duration of the SA measured in bytes transported.
.\"
.It Fl esp_frag Ar bytes
Specify esp fragment size for NAT-T (only valid for NAT-T SAs).
.\"
.It Fl ctx Ar doi Ar algorithm Ar context-name
Specify an access control label.
The access control label is interpreted by the LSM (e.g., SELinux).
Ultimately, it enables MAC on network communications.
.Bl -tag -width Fl -compact
.It Ar doi
The domain of interpretation, which is used by the
IKE daemon to identify the domain in which negotiation takes place.
.It Ar algorithm
Indicates the LSM for which the label is generated (e.g., SELinux).
.It Ar context-name
The string representation of the label that is interpreted by the LSM.
.El
.El
.\"
.Pp
.It Ar algorithm
.Bl -tag -width Fl -compact
.It Fl E Ar ealgo Ar key
Specify an encryption algorithm
.Ar ealgo
for ESP.
.It Fl E Ar ealgo Ar key Fl A Ar aalgo Ar key
Specify an 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
.Pq 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 a double-quoted character string, or a series of hexadecimal
digits preceded by
.Dq Li 0x .
.Pp
Possible values for
.Ar ealgo ,
.Ar aalgo ,
and
.Ar calgo
are specified in the
.Sx Algorithms
sections.
.\"
.Pp
.It Ar src_range
.It Ar dst_range
These select the communications that should be secured by IPsec.
They can be an IPv4/v6 address or an IPv4/v6 address range, and
may be accompanied by a TCP/UDP port specification.
This takes the following form:
.Bd -literal -offset
.Ar address
.Ar address/prefixlen
.Ar address[port]
.Ar address/prefixlen[port]
.Ed
.Pp
.Ar prefixlen
and
.Ar port
must be decimal numbers.
The square brackets around
.Ar port
are really necessary,
they are not man page meta-characters.
For FQDN resolution, the rules applicable to
.Ar src
and
.Ar dst
apply here as well.
.\"
.Pp
.It Ar upperspec
Upper-layer protocol to be used.
You can use one of the words in
.Pa /etc/protocols
as
.Ar upperspec ,
or
.Li icmp6 ,
.Li ip4 ,
.Li gre ,
or
.Li any .
.Li any
stands for
.Dq any protocol .
You can also use the protocol number.
Additional specification can be placed after the protocol name for
some protocols.
You can specify a type and/or a code of ICMP or ICMPv6.
The type is separated from a code by single comma and the code must
always be specified.
GRE key can be specified in dotted-quad format or as plain number.
When a zero is specified, the kernel deals with it as a wildcard.
Note that the kernel can not distinguish a wildcard from an ICPMv6
type of zero.
.Pp
For example, the following means that the policy doesn't require IPsec
for any inbound Neighbor Solicitation.
.Dl spdadd ::/0 ::/0 icmp6 135,0 -P in none ;
.Pp
A second example of requiring transport mode encryption of specific
GRE tunnel:
.Dl spdadd 0.0.0.0 0.0.0.0 gre 1234 ipsec esp/transport//require ;
.Pp
.Em Note :
.Ar upperspec
does not work against forwarding case at this moment,
as it requires extra reassembly at the forwarding node
.Pq not implemented at this moment .
There are many protocols in
.Pa /etc/protocols ,
but all protocols except of TCP, UDP, GRE, and ICMP may not be suitable
to use with IPsec.
You have to consider carefully what to use.
.\"
.Pp
.It Ar label
.Ar label
is the access control label for the policy.
This label is interpreted by the LSM (e.g., SELinux).
Ultimately, it enables MAC on network communications.
When a policy contains an access control label, SAs
negotiated with this policy will contain the label.
Its format:
.Bl -tag -width Fl -compact
.\"
.It Fl ctx Ar doi Ar algorithm Ar context-name
.Bl -tag -width Fl -compact
.It Ar doi
The domain of interpretation, which is used by the
IKE daemon to identify the domain in which negotiation takes place.
.It Ar algorithm
Indicates the LSM for which the label is generated (e.g., SELinux).
.It Ar context-name
The string representation of the label that is interpreted by the LSM.
.El
.El
.\"
.Pp
.It Ar policy
.Ar policy
is in one of the following three formats:
.Bl -item -compact
.It
.Fl P Ar direction [priority specification] Li discard
.It
.Fl P Ar direction [priority specification] Li none
.It
.Fl P Ar direction [priority specification] Li ipsec
.Ar protocol/mode/src-dst/level Op ...
.El
.Pp
You must specify the direction of its policy as
.Ar direction .
Either
.Ar out ,
.Ar in ,
or
.Ar fwd
can be used.
.Pp
.Ar priority specification
is used to control the placement of the policy within the SPD.
Policy position is determined by
a signed integer where higher priorities indicate the policy is placed
closer to the beginning of the list and lower priorities indicate the
policy is placed closer to the end of the list.
Policies with equal priorities are added at the end of groups
of such policies.
.Pp
Priority can only
be specified when setkey has been compiled against kernel headers that
support policy priorities (Linux \*[Gt]= 2.6.6).
If the kernel does not support priorities, a warning message will
be printed the first time a priority specification is used.
Policy priority takes one of the following formats:
.Bl -tag  -width "discard"
.It Ar {priority,prio} offset
.Ar offset
is an integer in the range from \-2147483647 to 214783648.
.It Ar {priority,prio} base {+,\-} offset
.Ar base
is either
.Li low (\-1073741824) ,
.Li def (0) ,
or
.Li high (1073741824)
.Pp
.Ar offset
is an unsigned integer.
It can be up to 1073741824 for
positive offsets, and up to 1073741823 for negative offsets.
.El
.Pp
.Li discard
means the packet matching indexes will be discarded.
.Li none
means that IPsec operation will not take place onto the packet.
.Li ipsec
means that IPsec operation will take place onto the packet.
.Pp
The
.Ar protocol/mode/src-dst/level
part specifies the rule how to process the packet.
Either
.Li ah ,
.Li esp ,
or
.Li ipcomp
must be used as
.Ar protocol .
.Ar mode
is either
.Li transport
or
.Li tunnel .
If
.Ar mode
is
.Li tunnel ,
you must specify the end-point addresses of the SA as
.Ar src
and
.Ar dst
with
.Sq -
between these addresses, which is used to specify the SA to use.
If
.Ar mode
is
.Li transport ,
both
.Ar src
and
.Ar dst
can be omitted.
.Ar level
is to be one of the following:
.Li default , use , require ,
or
.Li unique .
If the SA is not available in every level, the kernel will
ask the key exchange daemon to establish a suitable SA.
.Li default
means the kernel consults the system wide default for the protocol
you specified, e.g. the
.Li esp_trans_deflev
sysctl variable, when the kernel processes the packet.
.Li use
means that the kernel uses an SA if it's available,
otherwise the kernel keeps normal operation.
.Li require
means SA is required whenever the kernel sends a packet matched
with the policy.
.Li unique
is the same as
.Li require ;
in addition, it allows the policy to match the unique out-bound SA.
You just specify the policy level
.Li unique ,
.Xr racoon 8
will configure the SA for the policy.
If you configure the SA by manual keying for that policy,
you can put a decimal number as the policy identifier after
.Li unique
separated by a colon
.Sq \&:
like:
.Li unique:number
in order to bind this policy to the SA.
.Li number
must be between 1 and 32767.
It corresponds to
.Ar extensions Fl u
of the manual SA configuration.
When you want to use 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:
.Dl esp/transport//require ah/transport//require ;
The rule order is very important.
.Pp
When NAT-T is enabled in the kernel, policy matching for ESP over
UDP packets may be done on endpoint addresses and port
(this depends on the system.
System that do not perform the port check cannot support
multiple endpoints behind the same NAT).
When using ESP over UDP, you can specify port numbers in the endpoint
addresses to get the correct matching.
Here is an example:
.Bd -literal -offset
spdadd 10.0.11.0/24[any] 10.0.11.33/32[any] any \-P out ipsec
    esp/tunnel/192.168.0.1[4500]-192.168.1.2[30000]/require ;

.Ed
These ports must be left unspecified (which defaults to 0) for
anything other than ESP over UDP.
They can be displayed in SPD dump using
.Nm
.Fl DPp .
.Pp
Note that
.Dq Li discard
and
.Dq Li none
are not in the syntax described in
.Xr ipsec_set_policy 3 .
There are a few differences in the syntax.
See
.Xr ipsec_set_policy 3
for detail.
.El
.\"
.Ss Algorithms
The following list shows the supported algorithms.
.Sy protocol
and
.Sy algorithm
are almost orthogonal.
These authentication algorithms can be used as
.Ar aalgo
in
.Fl A Ar aalgo
of the
.Ar protocol
parameter:
.Pp
.Bd -literal -offset indent
algorithm	keylen (bits)
hmac-md5	128		ah: rfc2403
		128		ah-old: rfc2085
hmac-sha1	160		ah: rfc2404
		160		ah-old: 128bit ICV (no document)
keyed-md5	128		ah: 96bit ICV (no document)
		128		ah-old: rfc1828
keyed-sha1	160		ah: 96bit ICV (no document)
		160		ah-old: 128bit ICV (no document)
null		0 to 2048	for debugging
hmac-sha256	256		ah: 128bit ICV (RFC4868)
		256		ah-old: 128bit ICV (no document)
hmac-sha384	384		ah: 192bit ICV (RFC4868)
		384		ah-old: 128bit ICV (no document)
hmac-sha512	512		ah: 256bit ICV (RFC4868)
		512		ah-old: 128bit ICV (no document)
hmac-ripemd160	160		ah: 96bit ICV (RFC2857)
				ah-old: 128bit ICV (no document)
aes-xcbc-mac	128		ah: 96bit ICV (RFC3566)
		128		ah-old: 128bit ICV (no document)
tcp-md5		8 to 640	tcp: rfc2385
.Ed
.Pp
These encryption algorithms can be used as
.Ar ealgo
in
.Fl E Ar ealgo
of the
.Ar protocol
parameter:
.Pp
.Bd -literal -offset indent
algorithm	keylen (bits)
des-cbc		64		esp-old: rfc1829, esp: rfc2405
3des-cbc	192		rfc2451
null		0 to 2048	rfc2410
blowfish-cbc	40 to 448	rfc2451
cast128-cbc	40 to 128	rfc2451
des-deriv	64		ipsec-ciph-des-derived-01
3des-deriv	192		no document
rijndael-cbc	128/192/256	rfc3602
twofish-cbc	0 to 256	draft-ietf-ipsec-ciph-aes-cbc-01
aes-ctr		160/224/288	rfc3686
camellia-cbc	128/192/256	rfc4312
aes-gcm-16	160/224/288	rfc4106
aes-gmac	160/224/288	rfc4543
.Ed
.Pp
Note that the first 128/192/256 bits of a key for
.Li aes-ctr ,
.Li aes-gcm-16
or
.Li aes-gmac
will be used as AES key, and the remaining 32 bits will be used as nonce.
Also note that
.Li aes-gmac
does not encrypt the payload, it only provides authentication.
.Pp
These compression algorithms can be used as
.Ar calgo
in
.Fl C Ar calgo
of the
.Ar protocol
parameter:
.Pp
.Bd -literal -offset indent
algorithm
deflate		rfc2394
.Ed
.\"
.Ss RFC vs Linux kernel semantics
The Linux kernel uses the
.Ar fwd
policy instead of the
.Ar in
policy for packets what are forwarded through that particular box.
.Pp
In
.Ar kernel
mode,
.Nm
manages and shows policies and SAs exactly as they are stored in the kernel.
.Pp
In
.Ar RFC
mode,
.Nm
.Bl -item
.It
creates
.Ar fwd
policies for every
.Ar in
policy inserted
.It
(not implemented yet) filters out all
.Ar fwd
policies
.El
.Sh RETURN VALUES
The command exits with 0 on success, and non-zero on errors.
.\"
.Sh EXAMPLES
.Bd -literal -offset
add 3ffe:501:4819::1 3ffe:501:481d::1 esp 123457
	\-E des-cbc 0x3ffe05014819ffff ;

add \-6 myhost.example.com yourhost.example.com ah 123456
	\-A hmac-sha1 "AH SA configuration!" ;

add 10.0.11.41 10.0.11.33 esp 0x10001
	\-E des-cbc 0x3ffe05014819ffff
	\-A hmac-md5 "authentication!!" ;

get 3ffe:501:4819::1 3ffe:501:481d::1 ah 123456 ;

flush ;

dump esp ;

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 ;

add 10.1.10.34 10.1.10.36 tcp 0x1000 \-A tcp-md5 "TCP-MD5 BGP secret" ;

add 10.0.11.41 10.0.11.33 esp 0x10001
	\-ctx 1 1 "system_u:system_r:unconfined_t:SystemLow-SystemHigh"
	\-E des-cbc 0x3ffe05014819ffff;

spdadd 10.0.11.41 10.0.11.33 any
	\-ctx 1 1 "system_u:system_r:unconfined_t:SystemLow-SystemHigh"
	\-P out ipsec esp/transport//require ;
.Ed
.\"
.Sh SEE ALSO
.Xr ipsec_set_policy 3 ,
.Xr racoon 8 ,
.Xr sysctl 8
.Rs
.%T "Changed manual key configuration for IPsec"
.%U "http://www.kame.net/newsletter/19991007/"
.%D "October 1999"
.Re
.\"
.Sh HISTORY
The
.Nm
command first appeared in the WIDE Hydrangea IPv6 protocol stack
kit.
The command was completely re-designed in June 1998.
.\"
.Sh BUGS
.Nm
should report and handle syntax errors better.
.Pp
For IPsec gateway configuration,
.Ar src_range
and
.Ar dst_range
with TCP/UDP port numbers does not work, as the gateway does not
reassemble packets
.Pq it cannot inspect upper-layer headers .