(8)
tool to load configurations and credentials into the strongSwan IKE daemon.
For a description of the basic file syntax, including how to reference sections
or split the configuration in multiple files by including other files, refer to
strongswan.conf(5).
For all options that define a time, the time is specified in seconds. The
suffixes explicitly define the units for seconds, minutes, hours and days,
respectively.
The following settings can be used to configure connections, credentials and
pools.
- connections
-
Section defining IKE connection configurations.
The connections section defines IKE connection configurations, each in its own
subsections. In the keyword description below, the connection is named
<conn>,
but an arbitrary yet unique connection name can be chosen for each connection
subsection.
- connections.<conn>
-
Section for an IKE connection named <conn>.
- connections.<conn>.version [0]
-
IKE major version to use for connection.
1
uses IKEv1 aka ISAKMP,
2
uses
IKEv2. A connection using the default of
0
accepts both IKEv1 and IKEv2 as
responder, and initiates the connection actively with IKEv2.
- connections.<conn>.local_addrs [%any]
-
Local address(es) to use for IKE communication, comma separated. Takes single
IPv4/IPv6 addresses, DNS names, CIDR subnets or IP address ranges.
As initiator, the first non-range/non-subnet is used to initiate the connection
from. As responder, the local destination address must match at least to one of
the specified addresses, subnets or ranges.
If FQDNs are assigned they are resolved every time a configuration lookup is
done. If DNS resolution times out, the lookup is delayed for that time.
- connections.<conn>.remote_addrs [%any]
-
Remote address(es) to use for IKE communication, comma separated. Takes single
IPv4/IPv6 addresses, DNS names, CIDR subnets or IP address ranges.
As initiator, the first non-range/non-subnet is used to initiate the connection
to. As responder, the initiator source address must match at least to one of the
specified addresses, subnets or ranges.
If FQDNs are assigned they are resolved every time a configuration lookup is
done. If DNS resolution times out, the lookup is delayed for that time.
To initiate a connection, at least one specific address or DNS name must be
specified.
- connections.<conn>.local_port [500]
-
Local UDP port for IKE communication. By default the port of the socket backend
is used, which is usually
500.
If port
500
is used, automatic IKE port
floating to port 4500 is used to work around NAT issues.
Using a non-default local IKE port requires support from the socket backend in
use (socket-dynamic).
- connections.<conn>.remote_port [500]
-
Remote UDP port for IKE communication. If the default of port
500
is used,
automatic IKE port floating to port 4500 is used to work around NAT issues.
- connections.<conn>.proposals [default]
-
A proposal is a set of algorithms. For non-AEAD algorithms, this includes for
IKE an encryption algorithm, an integrity algorithm, a pseudo random function
and a Diffie-Hellman group. For AEAD algorithms, instead of encryption and
integrity algorithms, a combined algorithm is used.
In IKEv2, multiple algorithms of the same kind can be specified in a single
proposal, from which one gets selected. In IKEv1, only one algorithm per kind is
allowed per proposal, more algorithms get implicitly stripped. Use multiple
proposals to offer different algorithms combinations in IKEv1.
Algorithm keywords get separated using dashes. Multiple proposals may be
separated by commas. The special value
default
forms a default proposal of
supported algorithms considered safe, and is usually a good choice for
interoperability.
- connections.<conn>.vips []
-
Comma separated list of virtual IPs to request in IKEv2 configuration payloads
or IKEv1 Mode Config. The wildcard addresses
0.0.0.0
and
::
request an
arbitrary address, specific addresses may be defined. The responder may return a
different address, though, or none at all.
- connections.<conn>.aggressive [no]
-
Enables Aggressive Mode instead of Main Mode with Identity Protection.
Aggressive Mode is considered less secure, because the ID and HASH payloads are
exchanged unprotected. This allows a passive attacker to snoop peer identities,
and even worse, start dictionary attacks on the Preshared Key.
- connections.<conn>.pull [yes]
-
If the default of
yes
is used, Mode Config works in pull mode, where the
initiator actively requests a virtual IP. With
no,
push mode is used, where
the responder pushes down a virtual IP to the initiating peer.
Push mode is currently supported for IKEv1, but not in IKEv2. It is used by a
few implementations only, pull mode is recommended.
- connections.<conn>.dscp [000000]
-
Differentiated Services Field Codepoint to set on outgoing IKE packets for this
connection. The value is a six digit binary encoded string specifying the
Codepoint to set, as defined in RFC 2474.
- connections.<conn>.encap [no]
-
To enforce UDP encapsulation of ESP packets, the IKE daemon can fake the NAT
detection payloads. This makes the peer believe that NAT takes place on the
path, forcing it to encapsulate ESP packets in UDP.
Usually this is not required, but it can help to work around connectivity issues
with too restrictive intermediary firewalls.
- connections.<conn>.mobike [yes]
-
Enables MOBIKE on IKEv2 connections. MOBIKE is enabled by default on IKEv2
connections, and allows mobility of clients and multi-homing on servers by
migrating active IPsec tunnels.
Usually keeping MOBIKE enabled is unproblematic, as it is not used if the peer
does not indicate support for it. However, due to the design of MOBIKE, IKEv2
always floats to port 4500 starting from the second exchange. Some
implementations don't like this behavior, hence it can be disabled.
- connections.<conn>.dpd_delay [0s]
-
Interval to check the liveness of a peer actively using IKEv2 INFORMATIONAL
exchanges or IKEv1 R_U_THERE messages. Active DPD checking is only enforced if
no IKE or ESP/AH packet has been received for the configured DPD delay.
- connections.<conn>.dpd_timeout [0s]
-
Charon by default uses the normal retransmission mechanism and timeouts to check
the liveness of a peer, as all messages are used for liveness checking. For
compatibility reasons, with IKEv1 a custom interval may be specified; this
option has no effect on connections using IKE2.
- connections.<conn>.fragmentation [yes]
-
Use IKE fragmentation (proprietary IKEv1 extension or RFC 7383 IKEv2
fragmentation). Acceptable values are
yes
(the default),
accept,
force
and
no.
If set to
yes,
and the peer supports it, oversized IKE
messages will be sent in fragments. If set to
accept,
support for
fragmentation is announced to the peer but the daemon does not send its own
messages in fragments. If set to
force
(only supported for IKEv1) the initial
IKE message will already be fragmented if required. Finally, setting the option
to
no
will disable announcing support for this feature.
Note that fragmented IKE messages sent by a peer are always accepted
irrespective of the value of this option (even when set to
no).
- connections.<conn>.childless [allow]
-
Use childless IKE_SA initiation (RFC 6023) for IKEv2. Acceptable values are
allow
(the default),
force
and
never.
If set to
allow,
responders will
accept childless IKE_SAs (as indicated via notify in the IKE_SA_INIT response)
while initiators continue to create regular IKE_SAs with the first CHILD_SA
created during IKE_AUTH, unless the IKE_SA is initiated explicitly without any
children (which will fail if the responder does not support or has disabled this
extension). If set to
force,
only childless initiation is accepted and the
first CHILD_SA is created with a separate CREATE_CHILD_SA exchange (e.g. to use
an independent DH exchange for all CHILD_SAs). Finally, setting the option to
never
disables support for childless IKE_SAs as responder.
- connections.<conn>.send_certreq [yes]
-
Send certificate request payloads to offer trusted root CA certificates to the
peer. Certificate requests help the peer to choose an appropriate
certificate/private key for authentication and are enabled by default.
Disabling certificate requests can be useful if too many trusted root CA
certificates are installed, as each certificate request increases the size of
the initial IKE packets.
- connections.<conn>.send_cert [ifasked]
-
Send certificate payloads when using certificate authentication. With the
default of
ifasked
the daemon sends certificate payloads only if certificate
requests have been received.
never
disables sending of certificate payloads
altogether,
always
causes certificate payloads to be sent unconditionally
whenever certificate authentication is used.
- connections.<conn>.ppk_id []
-
String identifying the Postquantum Preshared Key (PPK) to be used.
- connections.<conn>.ppk_required [no]
-
Whether a Postquantum Preshared Key (PPK) is required for this connection.
- connections.<conn>.keyingtries [1]
-
Number of retransmission sequences to perform during initial connect. Instead of
giving up initiation after the first retransmission sequence with the default
value of
1,
additional sequences may be started according to the configured
value. A value of
0
initiates a new sequence until the connection establishes
or fails with a permanent error.
- connections.<conn>.unique [no]
-
Connection uniqueness policy to enforce. To avoid multiple connections from the
same user, a uniqueness policy can be enforced. The value
never
does never
enforce such a policy, even if a peer included INITIAL_CONTACT notification
messages, whereas
no
replaces existing connections for the same identity if a
new one has the INITIAL_CONTACT notify.
keep
rejects new connection attempts
if the same user already has an active connection,
replace
deletes any
existing connection if a new one for the same user gets established.
To compare connections for uniqueness, the remote IKE identity is used. If EAP
or XAuth authentication is involved, the EAP-Identity or XAuth username is used
to enforce the uniqueness policy instead.
On initiators this setting specifies whether an INITIAL_CONTACT notify is sent
during IKE_AUTH if no existing connection is found with the remote peer
(determined by the identities of the first authentication round). Unless set to
never
the client will send a notify.
- connections.<conn>.reauth_time [0s]
-
Time to schedule IKE reauthentication. IKE reauthentication recreates the
IKE/ISAKMP SA from scratch and re-evaluates the credentials. In asymmetric
configurations (with EAP or configuration payloads) it might not be possible to
actively reauthenticate as responder. The IKEv2 reauthentication lifetime
negotiation can instruct the client to perform reauthentication.
Reauthentication is disabled by default. Enabling it usually may lead to small
connection interruptions, as strongSwan uses a break-before-make policy with
IKEv2 to avoid any conflicts with associated tunnel resources.
- connections.<conn>.rekey_time [4h]
-
IKE rekeying refreshes key material using a Diffie-Hellman exchange, but does
not re-check associated credentials. It is supported in IKEv2 only, IKEv1
performs a reauthentication procedure instead.
With the default value IKE rekeying is scheduled every 4 hours, minus the
configured
rand_time.
If a
reauth_time
is configured,
rekey_time
defaults to zero disabling rekeying; explicitly set both to enforce rekeying and
reauthentication.
- connections.<conn>.over_time [10% of rekey_time/reauth_time]
-
Hard IKE_SA lifetime if rekey/reauth does not complete, as time. To avoid having
an IKE/ISAKMP kept alive if IKE reauthentication or rekeying fails perpetually,
a maximum hard lifetime may be specified. If the IKE_SA fails to rekey or
reauthenticate within the specified time, the IKE_SA gets closed.
In contrast to CHILD_SA rekeying,
over_time
is relative in time to the
rekey_time
and
reauth_time
values, as it applies to both.
The default is 10% of the longer of
rekey_time
and
reauth_time.
- connections.<conn>.rand_time [over_time]
-
Time range from which to choose a random value to subtract from rekey/reauth
times. To avoid having both peers initiating the rekey/reauth procedure
simultaneously, a random time gets subtracted from the rekey/reauth times.
The default is equal to the configured
over_time.
- connections.<conn>.pools []
-
Comma separated list of named IP pools to allocate virtual IP addresses and
other configuration attributes from. Each name references a pool by name from
either the
pools
section or an external pool.
- connections.<conn>.if_id_in [0]
-
XFRM interface ID set on inbound policies/SA, can be overridden by child config,
see there for details.
- connections.<conn>.if_id_out [0]
-
XFRM interface ID set on outbound policies/SA, can be overridden by child
config, see there for details.
- connections.<conn>.mediation [no]
-
Whether this connection is a mediation connection, that is, whether this
connection is used to mediate other connections using the IKEv2 Mediation
Extension. Mediation connections create no CHILD_SA.
- connections.<conn>.mediated_by []
-
The name of the connection to mediate this connection through. If given, the
connection will be mediated through the named mediation connection. The
mediation connection must have
mediation
enabled.
- connections.<conn>.mediation_peer []
-
Identity under which the peer is registered at the mediation server, that is,
the IKE identity the other end of this connection uses as its local identity on
its connection to the mediation server. This is the identity we request the
mediation server to mediate us with. Only relevant on connections that set
mediated_by.
If it is not given, the remote IKE identity of the first
authentication round of this connection will be used.
- connections.<conn>.local<suffix>
-
Section for a local authentication round. A local authentication round defines
the rules how authentication is performed for the local peer. Multiple rounds
may be defined to use IKEv2 RFC 4739 Multiple Authentication or IKEv1 XAuth.
Each round is defined in a section having
local
as prefix, and an optional
unique suffix. To define a single authentication round, the suffix may be
omitted.
- connections.<conn>.local<suffix>.round [0]
-
Optional numeric identifier by which authentication rounds are sorted. If not
specified rounds are ordered by their position in the config file/VICI message.
- connections.<conn>.local<suffix>.certs []
-
Comma separated list of certificate candidates to use for authentication. The
certificates may use a relative path from the
swanctl
x509
directory or an
absolute path.
The certificate used for authentication is selected based on the received
certificate request payloads. If no appropriate CA can be located, the first
certificate is used.
- connections.<conn>.local<suffix>.cert<suffix> []
-
Section for a certificate candidate to use for authentication. Certificates in
certs
are transmitted as binary blobs, these sections offer more flexibility.
- connections.<conn>.local<suffix>.cert<suffix>.file []
-
Absolute path to the certificate to load. Passed as-is to the daemon, so it must
be readable by it.
Configure either this or
handle,
but not both, in one section.
- connections.<conn>.local<suffix>.cert<suffix>.handle []
-
Hex-encoded CKA_ID of the certificate on a token.
Configure either this or
file,
but not both, in one section.
- connections.<conn>.local<suffix>.cert<suffix>.slot []
-
Optional slot number of the token that stores the certificate.
- connections.<conn>.local<suffix>.cert<suffix>.module []
-
Optional PKCS#11 module name.
- connections.<conn>.local<suffix>.pubkeys []
-
Comma separated list of raw public key candidates to use for authentication. The
public keys may use a relative path from the
swanctl
pubkey
directory or
an absolute path.
Even though multiple local public keys could be defined in principle, only the
first public key in the list is used for authentication.
- connections.<conn>.local<suffix>.auth [pubkey]
-
Authentication to perform locally.
pubkey
uses public key authentication using
a private key associated to a usable certificate.
psk
uses pre-shared key
authentication. The IKEv1 specific
xauth
is used for XAuth or Hybrid
authentication, while the IKEv2 specific
eap
keyword defines EAP
authentication.
For
xauth,
a specific backend name may be appended, separated by a dash. The
appropriate
xauth
backend is selected to perform the XAuth exchange. For
traditional XAuth, the
xauth
method is usually defined in the second
authentication round following an initial
pubkey
(or
psk)
round. Using
xauth
in the first round performs Hybrid Mode client authentication.
For
eap,
a specific EAP method name may be appended, separated by a dash. An
EAP module implementing the appropriate method is selected to perform the EAP
conversation.
If both peers support RFC 7427 ("Signature Authentication in IKEv2") specific
hash algorithms to be used during IKEv2 authentication may be configured. To do
so use
ike:
followed by a trust chain signature scheme constraint (see
description of the
remote
section's
auth
keyword). For example, with
ike:pubkey-sha384-sha256
a public key signature scheme with either SHA-384 or
SHA-256 would get used for authentication, in that order and depending on the
hash algorithms supported by the peer. If no specific hash algorithms are
configured, the default is to prefer an algorithm that matches or exceeds the
strength of the signature key. If no constraints with
ike:
prefix are
configured any signature scheme constraint (without
ike:
prefix) will also
apply to IKEv2 authentication, unless this is disabled in
strongswan.conf(5).
To use RSASSA-PSS signatures use
rsa/pss
instead of
pubkey
or
rsa
as in e.g.
ike:rsa/pss-sha256.
If
pubkey
or
rsa
constraints are configured RSASSA-PSS signatures will only be used if enabled in
strongswan.conf(5).
- connections.<conn>.local<suffix>.id []
-
IKE identity to use for authentication round. When using certificate
authentication, the IKE identity must be contained in the certificate, either as
subject or as subjectAltName.
The identity can be an IP address, a fully-qualified domain name, an email
address or a Distinguished Name for which the ID type is determined
automatically and the string is converted to the appropriate encoding. To
enforce a specific identity type, a prefix may be used, followed by a colon (:).
If the number sign (#) follows the colon, the remaining data is interpreted as
hex encoding, otherwise the string is used as-is as the identification data.
Note that this implies that no conversion is performed for non-string
identities. For example,
ipv4:10.0.0.1
does not create a valid ID_IPV4_ADDR
IKE identity, as it does not get converted to binary 0x0a000001. Instead, one
could use
ipv4:#0a000001
to get a valid identity, but just using the implicit
type with automatic conversion is usually simpler. The same applies to the ASN1
encoded types. The following prefixes are known:
ipv4,
ipv6,
rfc822,
email,
userfqdn,
fqdn,
dns,
asn1dn,
asn1gn
and
keyid.
Custom type
prefixes may be specified by surrounding the numerical type value by curly
brackets.
- connections.<conn>.local<suffix>.eap_id [id]
-
Client EAP-Identity to use in EAP-Identity exchange and the EAP method.
- connections.<conn>.local<suffix>.aaa_id [remote-id]
-
Server side EAP-Identity to expect in the EAP method. Some EAP methods, such as
EAP-TLS, use an identity for the server to perform mutual authentication. This
identity may differ from the IKE identity, especially when EAP authentication is
delegated from the IKE responder to an AAA backend.
For EAP-(T)TLS, this defines the identity for which the server must provide a
certificate in the TLS exchange.
- connections.<conn>.local<suffix>.xauth_id [id]
-
Client XAuth username used in the XAuth exchange.
- connections.<conn>.remote<suffix>
-
Section for a remote authentication round. A remote authentication round defines
the constraints how the peers must authenticate to use this connection. Multiple
rounds may be defined to use IKEv2 RFC 4739 Multiple Authentication or IKEv1
XAuth.
Each round is defined in a section having
remote
as prefix, and an optional
unique suffix. To define a single authentication round, the suffix may be
omitted.
- connections.<conn>.remote<suffix>.round [0]
-
Optional numeric identifier by which authentication rounds are sorted. If not
specified rounds are ordered by their position in the config file/VICI message.
- connections.<conn>.remote<suffix>.id [%any]
-
IKE identity to expect for authentication round. Refer to the
local
section's
id
keyword for details.
It's possible to use wildcards to match remote identities (e.g.
*@strongswan.org,
*.strongswan.org,
or
C=CH,O=strongSwan,CN=*).
Connections with exact matches are preferred. When using distinguished names
with wildcards, the
charon.rdn_matching
option in
strongswan.conf(5)
specifies how RDNs are matched.
- connections.<conn>.remote<suffix>.eap_id [id]
-
Identity to use as peer identity during EAP authentication. If set to
%any
the
EAP-Identity method will be used to ask the client for an identity.
- connections.<conn>.remote<suffix>.groups []
-
Comma separated authorization group memberships to require. The peer must prove
membership to at least one of the specified groups. Group membership can be
certified by different means, for example by appropriate Attribute Certificates
or by an AAA backend involved in the authentication.
- connections.<conn>.remote<suffix>.cert_policy []
-
Comma separated list of certificate policy OIDs the peer's certificate must
have. OIDs are specified using the numerical dotted representation.
- connections.<conn>.remote<suffix>.certs []
-
Comma separated list of certificates to accept for authentication. The
certificates may use a relative path from the
swanctl
x509
directory or an
absolute path.
- connections.<conn>.remote<suffix>.cert<suffix> []
-
Section for a certificate to accept for authentication. Certificates in
certs
are transmitted as binary blobs, these sections offer more flexibility.
- connections.<conn>.remote<suffix>.cert<suffix>.file []
-
Absolute path to the certificate to load. Passed as-is to the daemon, so it must
be readable by it.
Configure either this or
handle,
but not both, in one section.
- connections.<conn>.remote<suffix>.cert<suffix>.handle []
-
Hex-encoded CKA_ID of the certificate on a token.
Configure either this or
file,
but not both, in one section.
- connections.<conn>.remote<suffix>.cert<suffix>.slot []
-
Optional slot number of the token that stores the certificate.
- connections.<conn>.remote<suffix>.cert<suffix>.module []
-
Optional PKCS#11 module name.
- connections.<conn>.remote<suffix>.cacerts []
-
Comma separated list of CA certificates to accept for authentication. The
certificates may use a relative path from the
swanctl
x509ca
directory or
an absolute path.
- connections.<conn>.remote<suffix>.cacert<suffix> []
-
Section for a CA certificate to accept for authentication. Certificates in
cacerts
are transmitted as binary blobs, these sections offer more
flexibility.
- connections.<conn>.remote<suffix>.cacert<suffix>.file []
-
Absolute path to the certificate to load. Passed as-is to the daemon, so it must
be readable by it.
Configure either this or
handle,
but not both, in one section.
- connections.<conn>.remote<suffix>.cacert<suffix>.handle []
-
Hex-encoded CKA_ID of the CA certificate on a token.
Configure either this or
file,
but not both, in one section.
- connections.<conn>.remote<suffix>.cacert<suffix>.slot []
-
Optional slot number of the token that stores the CA certificate.
- connections.<conn>.remote<suffix>.cacert<suffix>.module []
-
Optional PKCS#11 module name.
- connections.<conn>.remote<suffix>.ca_id []
-
The specified identity must be contained in one (intermediate) CA of the remote
peer trustchain, either as subject or as subjectAltName. This has the same
effect as specifying
cacerts
to force clients under a CA to specific
connections; it does not require the CA certificate to be available locally, and
can be received from the peer during the IKE exchange.
- connections.<conn>.remote<suffix>.pubkeys []
-
Comma separated list of raw public keys to accept for authentication. The public
keys may use a relative path from the
swanctl
pubkey
directory or an
absolute path.
- connections.<conn>.remote<suffix>.revocation [relaxed]
-
Certificate revocation policy for CRL or OCSP revocation.
A
strict
revocation policy fails if no revocation information is available,
i.e. the certificate is not known to be unrevoked.
ifuri
fails only if a CRL/OCSP URI is available, but certificate revocation
checking fails, i.e. there should be revocation information available, but it
could not be obtained.
The default revocation policy
relaxed
fails only if a certificate is revoked,
i.e. it is explicitly known that it is bad.
- connections.<conn>.remote<suffix>.auth [pubkey]
-
Authentication to expect from remote. See the
local
section's
auth
keyword description about the details of supported mechanisms.
To require a trustchain public key strength for the remote side, specify the key
type followed by the minimum strength in bits (for example
ecdsa-384
or
rsa-2048-ecdsa-256).
To limit the acceptable set of hashing algorithms for
trustchain validation, append hash algorithms to
pubkey
or a key strength
definition (for example
pubkey-sha256-sha512,
rsa-2048-sha256-sha384-sha512
or
rsa-2048-sha256-ecdsa-256-sha256-sha384).
Unless disabled in
strongswan.conf(5),
or explicit IKEv2 signature constraints are configured
(refer to the description of the
local
section's
auth
keyword for
details), such key types and hash algorithms are also applied as constraints
against IKEv2 signature authentication schemes used by the remote side. To
require RSASSA-PSS signatures use
rsa/pss
instead of
pubkey
or
rsa
as in
e.g.
rsa/pss-sha256.
If
pubkey
or
rsa
constraints are configured
RSASSA-PSS signatures will only be accepted if enabled in
strongswan.conf(5).
To specify trust chain constraints for EAP-(T)TLS, append a colon to the EAP
method, followed by the key type/size and hash algorithm as discussed above
(e.g.
eap-tls:ecdsa-384-sha384).
- connections.<conn>.children.<child>
-
CHILD_SA configuration sub-section. Each connection definition may have one or
more sections in its
children
subsection. The section name defines the name of
the CHILD_SA configuration, which must be unique within the connection.
- connections.<conn>.children.<child>.ah_proposals []
-
AH proposals to offer for the CHILD_SA. A proposal is a set of algorithms. For
AH, this includes an integrity algorithm and an optional Diffie-Hellman group.
If a DH group is specified, CHILD_SA/Quick Mode rekeying and initial negotiation
uses a separate Diffie-Hellman exchange using the specified group (refer to
esp_proposals
for details).
In IKEv2, multiple algorithms of the same kind can be specified in a single
proposal, from which one gets selected. In IKEv1, only one algorithm per kind is
allowed per proposal, more algorithms get implicitly stripped. Use multiple
proposals to offer different algorithms combinations in IKEv1.
Algorithm keywords get separated using dashes. Multiple proposals may be
separated by commas. The special value
default
forms a default proposal of
supported algorithms considered safe, and is usually a good choice for
interoperability. By default no AH proposals are included, instead ESP is
proposed.
- connections.<conn>.children.<child>.esp_proposals [default]
-
ESP proposals to offer for the CHILD_SA. A proposal is a set of algorithms. For
ESP non-AEAD proposals, this includes an integrity algorithm, an encryption
algorithm, an optional Diffie-Hellman group and an optional Extended Sequence
Number Mode indicator. For AEAD proposals, a combined mode algorithm is used
instead of the separate encryption/integrity algorithms.
If a DH group is specified, CHILD_SA/Quick Mode rekeying and initial negotiation
use a separate Diffie-Hellman exchange using the specified group. However, for
IKEv2, the keys of the CHILD_SA created implicitly with the IKE_SA will always
be derived from the IKE_SA's key material. So any DH group specified here will
only apply when the CHILD_SA is later rekeyed or is created with a separate
CREATE_CHILD_SA exchange. A proposal mismatch might, therefore, not immediately
be noticed when the SA is established, but may later cause rekeying to fail.
Extended Sequence Number support may be indicated with the
esn
and
noesn
values, both may be included to indicate support for both modes. If omitted,
noesn
is assumed.
In IKEv2, multiple algorithms of the same kind can be specified in a single
proposal, from which one gets selected. In IKEv1, only one algorithm per kind is
allowed per proposal, more algorithms get implicitly stripped. Use multiple
proposals to offer different algorithms combinations in IKEv1.
Algorithm keywords get separated using dashes. Multiple proposals may be
separated by commas. The special value
default
forms a default proposal of
supported algorithms considered safe, and is usually a good choice for
interoperability. If no algorithms are specified for AH nor ESP, the
default
set of algorithms for ESP is included.
- connections.<conn>.children.<child>.sha256_96 [no]
-
HMAC-SHA-256 is used with 128-bit truncation with IPsec. For compatibility with
implementations that incorrectly use 96-bit truncation this option may be
enabled to configure the shorter truncation length in the kernel. This is not
negotiated, so this only works with peers that use the incorrect truncation
length (or have this option enabled).
- connections.<conn>.children.<child>.local_ts [dynamic]
-
Comma separated list of local traffic selectors to include in CHILD_SA. Each
selector is a CIDR subnet definition, followed by an optional proto/port
selector. The special value
dynamic
may be used instead of a subnet
definition, which gets replaced by the tunnel outer address or the virtual IP,
if negotiated. This is the default.
A protocol/port selector is surrounded by opening and closing square brackets.
Between these brackets, a numeric or
getservent(3)
protocol name may be
specified. After the optional protocol restriction, an optional port restriction
may be specified, separated by a slash. The port restriction may be numeric, a
getservent(3)
service name, or the special value
opaque
for RFC 4301
OPAQUE selectors. Port ranges may be specified as well, none of the kernel
backends currently support port ranges, though.
When IKEv1 is used only the first selector is interpreted, except if the Cisco
Unity extension plugin is used. This is due to a limitation of the IKEv1
protocol, which only allows a single pair of selectors per CHILD_SA. So to
tunnel traffic matched by several pairs of selectors when using IKEv1 several
children (CHILD_SAs) have to be defined that cover the selectors.
The IKE daemon uses traffic selector narrowing for IKEv1, the same way it is
standardized and implemented for IKEv2. However, this may lead to problems with
other implementations. To avoid that, configure identical selectors in such
scenarios.
- connections.<conn>.children.<child>.remote_ts [dynamic]
-
Comma separated list of remote selectors to include in CHILD_SA. See
local_ts
for a description of the selector syntax.
- connections.<conn>.children.<child>.rekey_time [1h]
-
Time to schedule CHILD_SA rekeying. CHILD_SA rekeying refreshes key material,
optionally using a Diffie-Hellman exchange if a group is specified in the
proposal.
To avoid rekey collisions initiated by both ends simultaneously, a value in the
range of
rand_time
gets subtracted to form the effective soft lifetime.
By default CHILD_SA rekeying is scheduled every hour, minus
rand_time.
- connections.<conn>.children.<child>.life_time [rekey_time + 10%]
-
Maximum lifetime before CHILD_SA gets closed. Usually this hard lifetime is
never reached, because the CHILD_SA gets rekeyed before. If that fails for
whatever reason, this limit closes the CHILD_SA.
The default is 10% more than the
rekey_time.
- connections.<conn>.children.<child>.rand_time [life_time - rekey_time]
-
Time range from which to choose a random value to subtract from
rekey_time.
The default is the difference between
life_time
and
rekey_time.
- connections.<conn>.children.<child>.rekey_bytes [0]
-
Number of bytes processed before initiating CHILD_SA rekeying. CHILD_SA rekeying
refreshes key material, optionally using a Diffie-Hellman exchange if a group is
specified in the proposal.
To avoid rekey collisions initiated by both ends simultaneously, a value in the
range of
rand_bytes
gets subtracted to form the effective soft volume limit.
Volume based CHILD_SA rekeying is disabled by default.
- connections.<conn>.children.<child>.life_bytes [rekey_bytes + 10%]
-
Maximum bytes processed before CHILD_SA gets closed. Usually this hard volume
limit is never reached, because the CHILD_SA gets rekeyed before. If that fails
for whatever reason, this limit closes the CHILD_SA.
The default is 10% more than
rekey_bytes.
- connections.<conn>.children.<child>.rand_bytes [life_bytes - rekey_bytes]
-
Byte range from which to choose a random value to subtract from
rekey_bytes.
The default is the difference between
life_bytes
and
rekey_bytes.
- connections.<conn>.children.<child>.rekey_packets [0]
-
Number of packets processed before initiating CHILD_SA rekeying. CHILD_SA
rekeying refreshes key material, optionally using a Diffie-Hellman exchange if a
group is specified in the proposal.
To avoid rekey collisions initiated by both ends simultaneously, a value in the
range of
rand_packets
gets subtracted to form the effective soft packet
count limit.
Packet count based CHILD_SA rekeying is disabled by default.
- connections.<conn>.children.<child>.life_packets [rekey_packets + 10%]
-
Maximum number of packets processed before CHILD_SA gets closed. Usually this
hard packets limit is never reached, because the CHILD_SA gets rekeyed before.
If that fails for whatever reason, this limit closes the CHILD_SA.
The default is 10% more than
rekey_bytes.
- connections.<conn>.children.<child>.rand_packets [life_packets - rekey_packets]
-
Packet range from which to choose a random value to subtract from
rekey_packets.
The default is the difference between
life_packets
and
rekey_packets.
- connections.<conn>.children.<child>.updown []
-
Updown script to invoke on CHILD_SA up and down events.
- connections.<conn>.children.<child>.hostaccess [no]
-
Hostaccess variable to pass to
updown
script.
- connections.<conn>.children.<child>.mode [tunnel]
-
IPsec Mode to establish CHILD_SA with.
tunnel
negotiates the CHILD_SA in IPsec
Tunnel Mode, whereas
transport
uses IPsec Transport Mode.
transport_proxy
signifying the special Mobile IPv6 Transport Proxy Mode.
beet
is the Bound End
to End Tunnel mixture mode, working with fixed inner addresses without the need
to include them in each packet.
Both
transport
and
beet
modes are subject to mode negotiation;
tunnel
mode
is negotiated if the preferred mode is not available.
pass
and
drop
are used to install shunt policies which explicitly bypass the
defined traffic from IPsec processing or drop it, respectively.
- connections.<conn>.children.<child>.policies [yes]
-
Whether to install IPsec policies or not. Disabling this can be useful in some
scenarios e.g. MIPv6, where policies are not managed by the IKE daemon.
- connections.<conn>.children.<child>.policies_fwd_out [no]
-
Whether to install outbound FWD IPsec policies or not. Enabling this is required
in case there is a drop policy that would match and block forwarded traffic for
this CHILD_SA.
- connections.<conn>.children.<child>.dpd_action [clear]
-
Action to perform for this CHILD_SA on DPD timeout. The default
clear
closes
the CHILD_SA and does not take further action.
trap
installs a trap policy,
which will catch matching traffic and tries to re-negotiate the tunnel
on-demand.
restart
immediately tries to re-negotiate the CHILD_SA under a
fresh IKE_SA.
- connections.<conn>.children.<child>.ipcomp [no]
-
Enable IPComp compression before encryption. If enabled, IKE tries to negotiate
IPComp compression to compress ESP payload data prior to encryption.
- connections.<conn>.children.<child>.inactivity [0s]
-
Timeout before closing CHILD_SA after inactivity. If no traffic has been
processed in either direction for the configured timeout, the CHILD_SA gets
closed due to inactivity. The default value of
0
disables inactivity checks.
- connections.<conn>.children.<child>.reqid [0]
-
Fixed reqid to use for this CHILD_SA. This might be helpful in some scenarios,
but works only if each CHILD_SA configuration is instantiated not more than
once. The default of
0
uses dynamic reqids, allocated incrementally.
- connections.<conn>.children.<child>.priority [0]
-
Optional fixed priority for IPsec policies. This could be useful to install
high-priority drop policies. The default of
0
uses dynamically calculated
priorities based on the size of the traffic selectors.
- connections.<conn>.children.<child>.interface []
-
Optional interface name to restrict IPsec policies.
- connections.<conn>.children.<child>.mark_in [0/0x00000000]
-
Netfilter mark and mask for input traffic. On Linux, Netfilter may require marks
on each packet to match an SA/policy having that option set. This allows
installing duplicate policies and enables Netfilter rules to select specific
SAs/policies for incoming traffic. Note that inbound marks are only set on
policies, by default, unless *mark_in_sa* is enabled. The special value
%unique
sets a unique mark on each CHILD_SA instance, beyond that the value
%unique-dir
assigns a different unique mark for each CHILD_SA direction
(in/out).
An additional mask may be appended to the mark, separated by
/.
The default
mask if omitted is 0xffffffff.
- connections.<conn>.children.<child>.mark_in_sa [no]
-
Whether to set *mark_in* on the inbound SA. By default, the inbound mark is only
set on the inbound policy. The tuple destination address, protocol and SPI is
unique and the mark is not required to find the correct SA, allowing to mark
traffic after decryption instead (where more specific selectors may be used) to
match different policies. Marking packets before decryption is still possible,
even if no mark is set on the SA.
- connections.<conn>.children.<child>.mark_out [0/0x00000000]
-
Netfilter mark and mask for output traffic. On Linux, Netfilter may require
marks on each packet to match a policy/SA having that option set. This allows
installing duplicate policies and enables Netfilter rules to select specific
policies/SAs for outgoing traffic. The special value
%unique
sets a unique
mark on each CHILD_SA instance, beyond that the value
%unique-dir
assigns a
different unique mark for each CHILD_SA direction (in/out).
An additional mask may be appended to the mark, separated by
/.
The default
mask if omitted is 0xffffffff.
- connections.<conn>.children.<child>.set_mark_in [0/0x00000000]
-
Netfilter mark applied to packets after the inbound IPsec SA processed them.
This way it's not necessary to mark packets via Netfilter before decryption or
right afterwards to match policies or process them differently (e.g. via policy
routing).
An additional mask may be appended to the mark, separated by
/.
The default
mask if omitted is 0xffffffff. The special value
%same
uses the value (but not
the mask) from
mark_in
as mark value, which can be fixed,
%unique
or
%unique-dir.
Setting marks in XFRM input requires Linux 4.19 or higher.
- connections.<conn>.children.<child>.set_mark_out [0/0x00000000]
-
Netfilter mark applied to packets after the outbound IPsec SA processed them.
This allows processing ESP packets differently than the original traffic (e.g.
via policy routing).
An additional mask may be appended to the mark, separated by
/.
The default
mask if omitted is 0xffffffff. The special value
%same
uses the value (but not
the mask) from
mark_out
as mark value, which can be fixed,
%unique
or
%unique-dir.
Setting marks in XFRM output is supported since Linux 4.14. Setting a mask
requires at least Linux 4.19.
- connections.<conn>.children.<child>.if_id_in [0]
-
XFRM interface ID set on inbound policies/SA. This allows installing duplicate
policies/SAs and associates them with an interface with the same ID. The special
value
%unique
sets a unique interface ID on each CHILD_SA instance, beyond
that the value
%unique-dir
assigns a different unique interface ID for each
CHILD_SA direction (in/out).
- connections.<conn>.children.<child>.if_id_out [0]
-
XFRM interface ID set on outbound policies/SA. This allows installing duplicate
policies/SAs and associates them with an interface with the same ID. The special
value
%unique
sets a unique interface ID on each CHILD_SA instance, beyond
that the value
%unique-dir
assigns a different unique interface ID for each
CHILD_SA direction (in/out).
The daemon will not install routes for CHILD_SAs that have this option set.
- connections.<conn>.children.<child>.tfc_padding [0]
-
Pads ESP packets with additional data to have a consistent ESP packet size for
improved Traffic Flow Confidentiality. The padding defines the minimum size of
all ESP packets sent.
The default value of 0 disables TFC padding, the special value
mtu
adds TFC
padding to create a packet size equal to the Path Maximum Transfer Unit.
- connections.<conn>.children.<child>.replay_window [32]
-
IPsec replay window to configure for this CHILD_SA. Larger values than the
default of 32 are supported using the Netlink backend only, a value of 0
disables IPsec replay protection.
- connections.<conn>.children.<child>.hw_offload [no]
-
Enable hardware offload for this CHILD_SA, if supported by the IPsec
implementation. The value
yes
enforces offloading and the installation will
fail if it's not supported by either kernel or device. The value
auto
enables offloading, if it's supported, but the installation does not fail
otherwise.
- connections.<conn>.children.<child>.copy_df [yes]
-
Whether to copy the DF bit to the outer IPv4 header in tunnel mode. This
effectively disables Path MTU discovery (PMTUD). Controlling this behavior is
not supported by all kernel interfaces.
- connections.<conn>.children.<child>.copy_ecn [yes]
-
Whether to copy the ECN (Explicit Congestion Notification) header field to/from
the outer IP header in tunnel mode. Controlling this behavior is not supported
by all kernel interfaces.
- connections.<conn>.children.<child>.copy_dscp [out]
-
Whether to copy the DSCP (Differentiated Services Field Codepoint) header field
to/from the outer IP header in tunnel mode. The value
out
only copies the
field from the inner to the outer header, the value
in
does the opposite and
only copies the field from the outer to the inner header when decapsulating, the
value
yes
copies the field in both directions, and the value
no
disables
copying the field altogether. Setting this to
yes
or
in
could allow an
attacker to adversely affect other traffic at the receiver, which is why the
default is
out.
Controlling this behavior is not supported by all kernel
interfaces.
- connections.<conn>.children.<child>.start_action [none]
-
Action to perform after loading the configuration. The default of
none
loads
the connection only, which then can be manually initiated or used as a responder
configuration.
The value
trap
installs a trap policy, which triggers the tunnel as soon as
matching traffic has been detected. The value
start
initiates the connection
actively.
When unloading or replacing a CHILD_SA configuration having a
start_action
different from
none,
the inverse action is performed. Configurations with
start
get closed, while such with
trap
get uninstalled.
- connections.<conn>.children.<child>.close_action [none]
-
Action to perform after a CHILD_SA gets closed by the peer. The default of
none
does not take any action,
trap
installs a trap policy for the CHILD_SA.
start
tries to re-create the CHILD_SA.
close_action
does not provide any guarantee that the CHILD_SA is kept alive.
It acts on explicit close messages only, but not on negotiation failures. Use
trap policies to reliably re-create failed CHILD_SAs.
- secrets
-
Section defining secrets for IKE/EAP/XAuth authentication and private key
decryption. The
secrets
section takes sub-sections having a specific prefix
which defines the secret type.
It is not recommended to define any private key decryption passphrases, as then
there is no real security benefit in having encrypted keys. Either store the key
unencrypted or enter the keys manually when loading credentials.
- secrets.eap<suffix>
-
EAP secret section for a specific secret. Each EAP secret is defined in a unique
section having the
eap
prefix. EAP secrets are used for XAuth authentication
as well.
- secrets.eap<suffix>.secret []
-
Value of the EAP/XAuth secret. It may either be an ASCII string, a hex encoded
string if it has a
0x
prefix or a Base64 encoded string if it has a
0s
prefix in its value.
- secrets.eap<suffix>.id<suffix> []
-
Identity the EAP/XAuth secret belongs to. Multiple unique identities may be
specified, each having an
id
prefix, if a secret is shared between multiple
users.
- secrets.xauth<suffix>
-
XAuth secret section for a specific secret.
xauth
is just an alias for
eap,
secrets under both section prefixes are used for both EAP and XAuth
authentication.
- secrets.ntlm<suffix>
-
NTLM secret section for a specific secret. Each NTLM secret is defined in a
unique section having the
ntlm
prefix. NTLM secrets may only be used for
EAP-MSCHAPv2 authentication.
- secrets.ntlm<suffix>.secret []
-
Value of the NTLM secret, which is the NT Hash of the actual secret, that is,
MD4(UTF-16LE(secret)). The resulting 16-byte value may either be given as a hex
encoded string with a
0x
prefix or as a Base64 encoded string with a
0s
prefix.
- secrets.ntlm<suffix>.id<suffix> []
-
Identity the NTLM secret belongs to. Multiple unique identities may be
specified, each having an
id
prefix, if a secret is shared between multiple
users.
- secrets.ike<suffix>
-
IKE preshared secret section for a specific secret. Each IKE PSK is defined in a
unique section having the
ike
prefix.
- secrets.ike<suffix>.secret []
-
Value of the IKE preshared secret. It may either be an ASCII string, a hex
encoded string if it has a
0x
prefix or a Base64 encoded string if it has a
0s
prefix in its value.
- secrets.ike<suffix>.id<suffix> []
-
IKE identity the IKE preshared secret belongs to. Multiple unique identities may
be specified, each having an
id
prefix, if a secret is shared between multiple
peers.
- secrets.ppk<suffix>
-
Postquantum Preshared Key (PPK) section for a specific secret. Each PPK is
defined in a unique section having the
ppk
prefix.
- secrets.ppk<suffix>.secret []
-
Value of the PPK. It may either be an ASCII string, a hex encoded string if
it has a
0x
prefix or a Base64 encoded string if it has a
0s
prefix in its
value. Should have at least 256 bits of entropy for 128-bit security.
- secrets.ppk<suffix>.id<suffix> []
-
PPK identity the PPK belongs to. Multiple unique identities may be specified,
each having an
id
prefix, if a secret is shared between multiple peers.
- secrets.private<suffix>
-
Private key decryption passphrase for a key in the
private
folder.
- secrets.private<suffix>.file []
-
File name in the
private
folder for which this passphrase should be used.
- secrets.private<suffix>.secret []
-
Value of decryption passphrase for private key.
- secrets.rsa<suffix>
-
Private key decryption passphrase for a key in the
rsa
folder.
- secrets.rsa<suffix>.file []
-
File name in the
rsa
folder for which this passphrase should be used.
- secrets.rsa<suffix>.secret []
-
Value of decryption passphrase for RSA key.
- secrets.ecdsa<suffix>
-
Private key decryption passphrase for a key in the
ecdsa
folder.
- secrets.ecdsa<suffix>.file []
-
File name in the
ecdsa
folder for which this passphrase should be used.
- secrets.ecdsa<suffix>.secret []
-
Value of decryption passphrase for ECDSA key.
- secrets.pkcs8<suffix>
-
Private key decryption passphrase for a key in the
pkcs8
folder.
- secrets.pkcs8<suffix>.file []
-
File name in the
pkcs8
folder for which this passphrase should be used.
- secrets.pkcs8<suffix>.secret []
-
Value of decryption passphrase for PKCS#8 key.
- secrets.pkcs12<suffix>
-
PKCS#12 decryption passphrase for a container in the
pkcs12
folder.
- secrets.pkcs12<suffix>.file []
-
File name in the
pkcs12
folder for which this passphrase should be used.
- secrets.pkcs12<suffix>.secret []
-
Value of decryption passphrase for PKCS#12 container.
- secrets.token<suffix>
-
Definition for a private key that's stored on a token/smartcard.
- secrets.token<suffix>.handle []
-
Hex-encoded CKA_ID of the private key on the token.
- secrets.token<suffix>.slot []
-
Optional slot number to access the token.
- secrets.token<suffix>.module []
-
Optional PKCS#11 module name to access the token.
- secrets.token<suffix>.pin []
-
Optional PIN required to access the key on the token. If none is provided the
user is prompted during an interactive --load-creds call.
- pools
-
Section defining named pools. Named pools may be referenced by connections with
the
pools
option to assign virtual IPs and other configuration attributes.
- pools.<name>
-
Section defining a single pool with a unique name.
- pools.<name>.addrs []
-
Subnet or range defining addresses allocated in pool. Accepts a single CIDR
subnet defining the pool to allocate addresses from or an address range
(<from>-<to>). Pools must be unique and non-overlapping.
- pools.<name>.<attr> []
-
Comma separated list of additional attributes of type
<attr>.
The attribute
type may be one of
dns,
nbns,
dhcp,
netmask,
server,
subnet,
split_include
and
split_exclude
to define addresses or CIDR subnets for the
corresponding attribute types. Alternatively,
<attr>
can be a numerical
identifier, for which string attribute values are accepted as well.
- authorities
-
Section defining attributes of certification authorities.
- authorities.<name>
-
Section defining a certification authority with a unique name.
- authorities.<name>.cacert []
-
CA certificate belonging to the certification authority. The certificates may
use a relative path from the
swanctl
x509ca
directory or an absolute path.
Configure one of
cacert,
file,
or
handle
per section.
- authorities.<name>.file []
-
Absolute path to the certificate to load. Passed as-is to the daemon, so it must
be readable by it.
Configure one of
cacert,
file,
or
handle
per section.
- authorities.<name>.handle []
-
Hex-encoded CKA_ID of the CA certificate on a token.
Configure one of
cacert,
file,
or
handle
per section.
- authorities.<name>.slot []
-
Optional slot number of the token that stores the CA certificate.
- authorities.<name>.module []
-
Optional PKCS#11 module name.
- authorities.<name>.crl_uris []
-
Comma-separated list of CRL distribution points (ldap, http, or file URI).
- authorities.<name>.ocsp_uris []
-
Comma-separated list of OCSP URIs.
- authorities.<name>.cert_uri_base []
-
Defines the base URI for the Hash and URL feature supported by IKEv2. Instead of
exchanging complete certificates, IKEv2 allows one to send an URI that resolves
to the DER encoded certificate. The certificate URIs are built by appending the
SHA1 hash of the DER encoded certificates to this base URI.