SETKEY(8) FreeBSD System Manager's Manual SETKEY(8)
NAME
setkey - manually manipulate the IPsec SA/SP database
SYNOPSIS
setkey [-v] -c
setkey [-v] -f filename
setkey [-v] -e script
setkey [-Pgltv] -D
setkey [-Pv] -F
setkey [-h] -x
DESCRIPTION
The setkey utility adds, updates, dumps, or flushes Security Association
Database (SAD) entries as well as Security Policy Database (SPD) entries
in the kernel.
The setkey utility takes a series of operations from the standard input
(if invoked with -c), from the file named filename (if invoked with -f
filename), or from the command line argument following the option (if
invoked with -e script).
-D Dump the SAD entries. If with -P, the SPD entries are dumped.
-F Flush the SAD entries. If with -P, the SPD entries are flushed.
-g Only SPD entries with global scope are dumped with -D and -P
flags.
-t Only SPD entries with ifnet scope are dumped with -D and -P
flags. Such SPD entries are linked to the corresponding
if_ipsec(4) virtual tunneling interface.
-h Add hexadecimal dump on -x mode.
-l Loop forever with short output on -D.
-v Be verbose. The program will dump messages exchanged on PF_KEY
socket, including messages sent from other processes to the
kernel.
-x Loop forever and dump all the messages transmitted to PF_KEY
socket. -xx makes each timestamp unformatted.
Configuration syntax
With -c or -f on the command line, setkey accepts the following
configuration syntax. Lines starting with hash signs (`#') are treated
as comment lines.
add [-46n] src dst protocol spi [extensions] algorithm ... ;
Add an SAD entry. add can fail with multiple reasons, including
when the key length does not match the specified algorithm.
get [-46n] src dst protocol spi ;
Show an SAD entry.
delete [-46n] src dst protocol spi ;
Remove an SAD entry.
deleteall [-46n] src dst protocol ;
Remove all SAD entries that match the specification.
flush [protocol] ;
Clear all SAD entries matched by the options. -F on the command
line achieves the same functionality.
dump [protocol] ;
Dumps all SAD entries matched by the options. -D on the command
line achieves the same functionality.
spdadd [-46n] src_range dst_range upperspec policy ;
Add an SPD entry.
spddelete [-46n] src_range dst_range upperspec -P direction ;
Delete an SPD entry.
spdflush ;
Clear all SPD entries. -FP on the command line achieves the same
functionality.
spddump ;
Dumps all SPD entries. -DP on the command line achieves the same
functionality.
Meta-arguments are as follows:
src
dst Source/destination of the secure communication is specified as
IPv4/v6 address. The setkey utility can resolve an FQDN into
numeric addresses. If the FQDN resolves into multiple addresses,
setkey will install multiple SAD/SPD entries into the kernel by
trying all possible combinations. -4, -6 and -n restricts the
address resolution of FQDN in certain ways. -4 and -6 restrict
results into IPv4/v6 addresses only, respectively. -n avoids
FQDN resolution and requires addresses to be numeric addresses.
protocol
protocol is one of following:
esp ESP based on rfc2406
esp-old ESP based on rfc1827
ah AH based on rfc2402
ah-old AH based on rfc1826
ipcomp IPComp
tcp TCP-MD5 based on rfc2385
spi Security Parameter Index (SPI) for the SAD and the SPD. spi must
be a decimal number, or a hexadecimal number with `0x' prefix.
SPI values between 0 and 255 are reserved for future use by IANA
and they cannot be used.
extensions
take some of the following:
-m mode Specify a security protocol mode for use. mode is one
of following: transport, tunnel or any. The default
value is any.
-r size Specify the bitmap size in octets of the anti-replay
window. size is a 32-bit unsigned integer, and its
value is one eighth of the anti-replay window size in
packets. If size is zero or not specified, an anti-
replay check does not take place.
-u id Specify the identifier of the policy entry in SPD. See
policy.
-f pad_option
defines the content of the ESP padding. pad_option is
one of following:
zero-pad All of the padding are zero.
random-pad A series of randomized values are set.
seq-pad A series of sequential increasing numbers
started from 1 are set.
-f nocyclic-seq
Do not allow cyclic sequence number.
-lh time
-ls time Specify hard/soft life time duration of the SA.
-natt oai [ sport ] oar [ dport ]
Manually configure NAT-T for the SA, by specifying
initiator oai and requestor oar ip addresses and ports.
Note that the `[' and `]' symbols are part of the
syntax for the ports specification, not indication of
the optional components.
-natt_mtu fragsize
Configure NAT-T fragment size.
-esn Enable Extended Sequence Number extension for this SA.
-hwif ifname
Request hardware offload to the specified interface
ifname (only). By default offload occurs to all
capable interfaces.
algorithm
-E ealgo key
Specify an encryption or Authenticated Encryption
with Associated Data (AEAD) algorithm ealgo for ESP.
-E ealgo key -A aalgo key
Specify a encryption algorithm ealgo, as well as a
payload authentication algorithm aalgo, for ESP.
-A aalgo key
Specify an authentication algorithm for AH.
-C calgo [-R]
Specify a compression algorithm for IPComp. If -R is
specified, the spi field value will be used as the
IPComp CPI (compression parameter index) on wire as
is. If -R is not specified, the kernel will use
well-known CPI on wire, and spi field will be used
only as an index for kernel internal usage.
key must be double-quoted character string, or a series of
hexadecimal digits preceded by `0x'.
Possible values for ealgo, aalgo and calgo are specified in
separate section.
src_range
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:
address
address/prefixlen
address[port]
address/prefixlen[port]
prefixlen and port must be a decimal number. The square brackets
around port are necessary and are not manpage metacharacters.
For FQDN resolution, the rules applicable to src and dst apply
here as well.
upperspec
The upper layer protocol to be used. You can use one of the
words in /etc/protocols as upperspec, as well as icmp6, ip4, or
any. The word any stands for "any protocol". The protocol
number may also be used to specify the upperspec. A type and
code related to ICMPv6 may also be specified as an upperspec.
The type is specified first, followed by a comma and then the
relevant code. The specification must be placed after 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:
spdadd ::/0 ::/0 icmp6 135,0 -P in none;
NOTE: 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 /etc/protocols, protocols other than TCP, UDP and
ICMP may not be suitable to use with IPsec.
policy policy is expressed in one of the following three formats:
-P direction discard
-P direction none
-P direction ipsec protocol/mode/src-dst/level [...]
direction The direction of a policy must be specified as one
of: out or in.
policy level The direction is followed by one of the following
policy levels: discard, none, or ipsec.
o The discard policy level means that packets
matching the supplied indices will be
discarded.
o The none policy level means that IPsec
operations will not take place on the packet.
o The ipsec policy level means that IPsec
operation will take place onto the packet.
protocol/mode/src-dst/level
The protocol/mode/src-dst/level statement gives the
rule for how to process the packet.
o The protocol is specified as ah, esp or ipcomp.
o The mode is either transport or tunnel.
If mode is tunnel, you must specify the end-point
addresses of the SA as src and dst with a dash,
`-', between the addresses.
If mode is transport, both src and dst can be
omitted.
The level is one of the following: default, use,
require or unique. If the SA is not available in
every level, the kernel will request the SA from
the key exchange daemon.
o A value of default tells the kernel to use the
system wide default protocol e.g., the one from
the esp_trans_deflev sysctl variable, when the
kernel processes the packet.
o A value of use means that the kernel will use
an SA if it is available, otherwise the kernel
will pass the packet as it would normally.
o A value of require means that an SA is required
whenever the kernel sends a packet matched that
matches the policy.
o The unique level is the same as require but, in
addition, it allows the policy to bind with the
unique out-bound SA.
For example, if you specify the policy level
unique, racoon(8) (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 unique separated by
colon `:' as in the following example:
unique:number. In order to bind this policy to
the SA, number must be between 1 and 32767,
which corresponds to extensions -u of manual SA
configuration.
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:
esp/transport//require ah/transport//require;
The rule order is very important.
Note that "discard" and "none" are not in the syntax described in
ipsec_set_policy(3). There are small, but important, differences
in the syntax. See ipsec_set_policy(3) for details.
ALGORITHMS
The following lists show the supported algorithms.
Authentication Algorithms
The following authentication algorithms can be used as aalgo in the -A
aalgo of the protocol parameter:
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)
Encryption Algorithms
The following encryption algorithms can be used as the ealgo in the -E
ealgo of the protocol parameter:
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
Note that the first 128/192/256 bits of a key for aes-ctr or aes-gcm-16
will be used as the AES key, and the remaining 32 bits will be used as
the nonce.
AEAD encryption algorithms such as aes-gcm-16 include authentication and
should not be paired with a separate authentication algorithm via -A.
Compression Algorithms
The following compression algorithms can be used as the calgo in the -C
calgo of the protocol parameter:
algorithm comment
deflate rfc2394
EXIT STATUS
The setkey utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
Add an ESP SA between two IPv6 addresses using the AES-GCM AEAD
algorithm.
add 3ffe:501:4819::1 3ffe:501:481d::1 esp 123457
-E aes-gcm-16 0x3ffe050148193ffe050148193ffe050148193ffe ;
Add an authentication SA between two FQDN specified hosts:
add -6 myhost.example.com yourhost.example.com ah 123456
-A hmac-sha2-256 "AH SA configuration!" ;
Get the SA information associated with first example above:
get 3ffe:501:4819::1 3ffe:501:481d::1 ah 123456 ;
Flush all entries from the database:
flush ;
Dump the ESP entries from the database:
dump esp ;
Add a security policy between two networks that uses ESP in tunnel mode:
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 ;
Use TCP MD5 between two numerically specified hosts:
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" ;
SEE ALSO
ipsec_set_policy(3), if_ipsec(4), racoon(8) (ports/security/ipsec-tools),
sysctl(8)
Changed manual key configuration for IPsec,
https://www.kame.net/newsletter/19991007/, October 1999.
HISTORY
The setkey utility first appeared in WIDE Hydrangea IPv6 protocol stack
kit. The utility was completely re-designed in June 1998. It first
appeared in FreeBSD 4.0.
BUGS
The setkey utility should report and handle syntax errors better.
For IPsec gateway configuration, src_range and dst_range with TCP/UDP
port number do not work, as the gateway does not reassemble packets
(cannot inspect upper-layer headers).
FreeBSD 15.1-STABLE-HBSD August 25, 2024 SETKEY(8)