Name

The setkey

utility takes a series of operations from the standard input (if invoked with -c ) or the file named filename (if invoked with -f filename).

-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.
-a	The setkey utility usually does not display dead SAD entries with -D . If with -a , the dead SAD entries will be displayed as well. A dead SAD entry means that it has been expired but remains in the system because it is referenced by some SPD entries.
-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 timestamps 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 a 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. TCP-MD5 associations must use 0x1000 and therefore only have per-host granularity at this time.
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 window size of bytes for replay prevention. size must be decimal number in 32-bit word. If size is zero or not specified, 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.

algorithm

-E ealgo key
	Specify an encryption 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, 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 decimal number. The square bracket around port is really necessary. They are not manpage metacharacters. For FQDN resolution, the rules applicable to src and dst apply here as well.
upperspec
	Upper-layer protocol to be used. Use one of the words in /etc/protocols as upperspec. Or icmp6, ip4, and any can be specified. any stands for "any protocol". Also, use the protocol number. Specify a type and/or a code of ICMPv6 when upper-layer protocol is ICMPv6. The specification can be placed after icmp6. A type is separated with a code by single comma. A code must be specified anytime. When a zero is specified, the kernel deals with it as a wildcard. Note that the kernel cannot distinguish a wildcard from that a type of ICMPv6 is zero. For example, the following means the policy does not require IPsec for any inbound Neighbor Solicitation:     spdadd ::/0 ::/0 icmp6 135,0 -P in none; NOTE: upperspec does not work against forwarding case at this moment, as it requires extra reassembly at forwarding node (not implemented at this moment). There are many protocols in /etc/protocols, but protocols except of TCP, UDP and ICMP may not be suitable to use with IPsec. be cautious when using the protocols.
policy
	policy is the one of the following three formats:
-P direction discard -P direction none
protocol/mode/src-dst/level [...]
	Specify the direction of its policy as direction. Either out or in are used. discard means the packet matching indexes will be discarded. none means that IPsec operation will not take place onto the packet. ipsec means that IPsec operation will take place onto the packet. The part of protocol/mode/src-dst/level specifies the rule how to process the packet. Either ah, esp or ipcomp is to be set as protocol. mode is either transport or tunnel. If mode is tunnel, specify the end-points addresses of the SA as src and dst with '-' between these addresses which is used to specify the SA to use. If mode is transport, both src and dst can be omitted. level is to be one of the following: default, use, require or unique. If the SA is not available in every level, the kernel will request getting SA to the key exchange daemon. default means the kernel consults to the system wide default against the specified protocol , for example, esp_trans_deflev sysctl variable, when the kernel processes the packet. use means that the kernel use a SA if it is available, otherwise the kernel keeps normal operation. require means SA is required whenever the kernel sends a packet matched with the policy. unique is the same to require. In addition, it allows the policy to bind with the unique out-bound SA. Specify the policy level unique, racoon will configure the SA for the policy. If the SA is configured by manual keying for that policy, put the decimal number as the policy identifier after unique separated by colon ‘:’ like the following; unique:number. In order to bind this policy to the SA, number must be between 1 and 32767. It corresponds to extensions-u of the manual SA configuration. In order to use the SA bundle, multiple rules can be defined. For example, if an IP header was followed by AH header followed by 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. There are little differences in the syntax. See ipsec_set_policy for detail.

algorithm       keylen (bits)   comment
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-sha2-256   256             ah: 96bit ICV
                                (draft-ietf-ipsec-ciph-sha-256-00)
                256             ah-old: 128bit ICV (no document)
hmac-sha2-384   384             ah: 96bit ICV (no document)
                384             ah-old: 128bit ICV (no document)
hmac-sha2-512   512             ah: 96bit ICV (no document)
                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

Followings are the list of encryption algorithms that can be used as ealgo in -E ealgo of protocol parameter:

algorithm       keylen (bits)   comment
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
aes-ctr         160/224/288     draft-ietf-ipsec-ciph-aes-ctr-03

Note that the first 128 bits of a key for aes-ctr will be used as AES key, and remaining 32 bits will be used as nonce.

Followings are the list of compression algorithms that can be used as calgo in -C calgo of protocol parameter:

algorithm       comment
deflate         rfc2394

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" ;

Changed manual key configuration for IPsec

The setkey

utility first appeared in WIDE Hydrangea IPv6 protocol stack kit. The utility was completely re-designed in June 1998.

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).

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