Manpages

NAME

isakmpd.conf — configuration file for isakmpd

DESCRIPTION

isakmpd.conf is the configuration file for the isakmpd daemon managing security association and key management for the IPsec layer of the kernel’s networking stack.

The file is of a well known type of format called .INI style, named after the suffix used by an overrated windowing environment for its configuration files. This format consists of sections, each beginning with a line looking like:

[Section name]
Between the brackets is the name of the section following this section header. Inside a section many tag/value pairs can be stored, each one looking like:

Tag=Value
If the value needs more space than fits on a single line it’s possible to continue it on the next by ending the first with a backslash character immediately before the newline character. This method can extend a value for an arbitrary number of lines.

Comments can be put anywhere in the file by using a hash mark (’#’). The comment extends to the end of the current line.

Often the right-hand side values consist of other section names. This results in a tree structure. Some values are treated as a list of several scalar values. Such lists always use a comma character as the separator. Some values are formatted like this: X,Y:Z, which is an offer/accept syntax, where X is a value we offer and Y:Z is a range of accepted values, inclusive.

To activate changes to isakmpd.conf without restarting isakmpd, send a SIGHUP signal to the daemon process.

Auto-generated parts of the configuration
Some predefined section names are recognized by the daemon, avoiding the need to fully specify the Main Mode transforms and Quick Mode suites, protocols, and transforms.

For Main Mode:
{DES,BLF,3DES,CAST,AES}-{MD5,SHA}[-GRP{1,2,5,14}][-{DSS,RSA_SIG}]

For Quick Mode:
QM-{proto}[-TRP]-{cipher}[-{hash}][-PFS[-{group}]]-SUITE

where
{proto} is either ESP or AH
{cipher} is either DES, 3DES, CAST, BLF or AES
{hash} is either MD5, SHA, RIPEMD, SHA2-{256,384,512}
{group} is either GRP1, GRP2, GRP5 or GRP14

For example, 3DES-SHA means: 3DES encryption, SHA hash, and authorization by pre-shared keys. Similarly, QM-ESP-3DES-SHA-PFS-SUITE means: ESP protocol, 3DES encryption, SHA hash, and use Perfect Forward Secrecy.

Unless explicitly stated with -GRP1, 2, 5 or 14 transforms and PFS suites use DH group 2. There are currently no predefined ESP+AH Quick Mode suites.

The predefinitions include some default values for the special sections "General", "Keynote", "X509-certificates", and "Default-phase-1-configuration". These default values are presented in the example below.

All autogenerated values can be overridden by manual entries by using the same section and tag names in the configuration file. In particular, the default phase 1 (Main or Aggressive Mode) and phase 2 (Quick Mode) lifetimes can be overridden by these tags under the "General" section;

[General]

The Main Mode lifetime currently defaults to one hour (minimum 60 seconds, maximum 1 day). The Quick Mode lifetime defaults to 20 minutes (minimum 60 seconds, maximum 1 day).

Also, the default phase 1 ID can be set by creating a <Phase1-ID> section, as shown below, and adding this tag under the "General" section;

[General]

[Phase1-ID-name]

Roots

General

Generic global configuration parameters

Default-phase-1-ID

Optional default phase 1 ID name.

Default-phase-1-lifetime

The default lifetime for autogenerated transforms (phase 1). If unspecified, the value 3600,60:86400 is used as the default.

Default-phase-2-lifetime

The default lifetime for autogenerated suites (phase 2). If unspecified, the value 1200,60:86400 is used as the default.

Default-phase-2-suites

A list of phase 2 suites that will be used when establishing dynamic SAs. If left unspecified, QM-ESP-3DES-SHA-PFS-SUITE is used as the default.

Acquire-Only

If this tag is defined, isakmpd will not set up flows automatically. This is useful when flows are configured with ipsecadm(4) or by other programs like bgpd(8). Thus isakmpd only takes care of the SA establishment.

Check-interval

The interval between watchdog checks of connections we want up at all times.

DPD-check-interval

The interval between RFC 3706 (Dead Peer Detection) messages. The default value is 0 (zero), which means DPD is disabled.

Exchange-max-time

How many seconds should an exchange maximally take to set up before we give up.

Listen-on

A list of IP-addresses OK to listen on. This list is used as a filter for the set of addresses the interfaces configured provides. This means that we won’t see if an address given here does not exist on this host, and thus no error is given for that case.

Loglevel

A list of the form class=level, where both class and level are numbers. This is similar to the -D command line switch of isakmpd. See isakmpd(8) for details.

Logverbose

If this tag is defined, whatever the value is, verbose logging is enabled. This is similar to the -v command line switch of isakmpd. See isakmpd(8) for details.

NAT-T-Keepalive

The number of seconds between NAT-T keepalive messages, sent by the peer behind NAT to keep the mapping active. Defaults to 20.

Policy-file

The name of the file that contains keynote(4) policies. The default is "/etc/isakmpd/isakmpd.policy".

Pubkey-directory

The directory in which isakmpd.conf looks for explicitly trusted public keys. The default is "/etc/isakmpd/pubkeys". Read isakmpd(8) for the required naming convention of the files in here.

Renegotiate-on-HUP

If this tag is defined, whatever the value is, isakmpd will renegotiate all current phase 2 SAs when the daemon receives a SIGHUP signal, or an ’R’ is sent to the FIFO interface (see isakmpd(8)).

Retransmits

How many times should a message be retransmitted before giving up.

Shared-SADB

If this tag is defined, whatever the value is, some semantics of isakmpd.conf are changed so that multiple instances can run on top of one SADB and set up SAs with each other. Specifically this means replay protection will not be asked for, and errors that can occur when updating an SA with its parameters a 2nd time will be ignored.

Use-Keynote

This tag controls the use of keynote(4) policy checking. The default value is "yes", which enables the policy checking. When set to any other value, policies will not be checked. This is useful when policies for flows and SA establishment are arranged by other programs like ipsecadm(8) or bgpd(8).

Phase 1

ISAKMP SA negotiation parameter root

<IP-address>

A name of the ISAKMP peer at the given IP-address.

Default

A name of the default ISAKMP peer. Incoming phase 1 connections from other IP-addresses will use this peer name.
This name is used as the section name for further information to be found. Look at <ISAKMP-peer> below.

Phase 2

IPsec SA negotiation parameter root

Connections

A list of directed IPsec "connection" names that should be brought up automatically, either on first use if the system supports it, or at startup of the daemon. These names are section names where further information can be found. Look at <IPsec-connection> below. Normally any connections mentioned here are treated as part of the "Passive-connection" list we present below, however there is a flag: "Active-only" that disables this behaviour. This too is mentioned in the <IPsec-connection> section, in the "Flags" tag.

Passive-connections

A list of IPsec "connection" names we recognize and accept initiations for. These names are section names where further information can be found. Look at <IPsec-connection> below. Currently only the Local-ID and Remote-ID tags are looked at in those sections, as they are matched against the IDs given by the initiator.

KeyNote

Credential-directory

A directory containing directories named after IDs (IP addresses, ’’user@domain’’, or hostnames) that contain files named ’’credentials’’ and ’’private_key’’.

The credentials file contains keynote(4) credentials that are sent to a remote IKE daemon when we use the associated ID, or credentials that we may want to consider when doing an exchange with a remote IKE daemon that uses that ID. Note that, in the former case, the last credential in the file MUST contain our public key in its Licensees field. More than one credentials may exist in the file. They are separated by whitelines (the format is essentially the same as that of the policy file). The credentials are of the same format as the policies described in isakmpd.policy(5). The only difference is that the Authorizer field contains a public key, and the assertion is signed. Signed assertions can be generated using the keynote(1) utility.

The private_key file contains the private RSA key we use for authentication. If the directory (and the files) exist, they take precedence over X509-based authentication.

X509-Certificates

Accept-self-signed

If this tag is defined, whatever the value is, certificates that do not originate from a trusted CA but are self-signed will be accepted.

Ca-directory

A directory containing PEM certificates of certification authorities that we trust to sign other certificates. Note that for a CA to be really trusted, it needs to be somehow referred to by policy, in isakmpd.policy(5). The certificates in this directory are used for the actual X.509 authentication and for cross-referencing policies that refer to Distinguished Names (DNs). Keeping a separate directory (as opposed to integrating policies and X.509 CA certificates) allows for maintenance of a list of "well known" CAs without actually having to trust all (or any) of them.

Cert-directory

A directory containing PEM certificates that we trust to be valid. These certificates are used in preference to those passed in messages and are required to have a subjectAltName extension containing the certificate holder identity; usually IP address, FQDN, or User FQDN, as provided by certpatch(8).

Private-key

The private key matching the public key of our certificate (which should be in the "Cert-directory", and have an appropriate subjectAltName field).

Referred-to sections

<ISAKMP-peer>

Parameters for negotiation with an ISAKMP peer

Phase

The constant 1, as ISAKMP-peers and IPsec-connections really are handled by the same code inside isakmpd.

Transport

The name of the transport protocol, defaults to UDP.

Port

In case of UDP, the UDP port number to send to. This is optional, the default value is 500 which is the IANA-registered number for ISAKMP.

Local-address

The Local IP-address to use, if we are multi-homed, or have aliases.

Address

If existent, the IP-address of the peer.

Configuration

The name of the ISAKMP-configuration section to use. Look at <ISAKMP-configuration> below. If unspecified, defaults to "Default-phase-1-configuration".

Authentication

If existent, authentication data for this specific peer. In the case of preshared key, this is the key value itself.

ID

If existent, the name of the section that describes the local client ID that we should present to our peer. If not present, it defaults to the address of the local interface we are sending packets over to the remote daemon. Look at <Phase1-ID> below.

Remote-ID

If existent, the name of the section that describes the remote client ID we expect the remote daemon to send us. If not present, it defaults to the address of the remote daemon. Look at <Phase1-ID> below.

Flags

A comma-separated list of flags controlling the further handling of the ISAKMP SA. Currently there are no specific ISAKMP SA flags defined.

<Phase1-ID>

ID-type

The ID type as given by the RFC specifications. For phase 1 this is currently IPV4_ADDR, IPV4_ADDR_SUBNET, IPV6_ADDR, IPV6_ADDR_SUBNET, FQDN, USER_FQDN or KEY_ID.

Address

If the ID-type is IPV4_ADDR or IPV6_ADDR, this tag should exist and be an IP-address.

Network

If the ID-type is IPV4_ADDR_SUBNET or IPV6_ADDR_SUBNET this tag should exist and be a network address.

Netmask

If the ID-type is IPV4_ADDR_SUBNET or IPV6_ADDR_SUBNET this tag should exist and be a network subnet mask.

Name

If the ID-type is FQDN, USER_FQDN or KEY_ID, this tag should exist and contain a domain name, user@domain, or other identifying string respectively.

In the case of KEY_ID, note that the IKE protocol allows any octet sequence to be sent or received under this payload, potentially including non-printable ones. isakmpd(8) can only transmit printable KEY_ID payloads, but can receive and process arbitrary KEY_ID payloads. This effectively means that non-printable KEY_ID remote identities cannot be verified through this means, although it is still possible to do so through isakmpd.policy(5).

<ISAKMP-configuration>

DOI

The domain of interpretation as given by the RFCs. Normally IPSEC. If unspecified, defaults to IPSEC.

EXCHANGE_TYPE

The exchange type as given by the RFCs. For main mode this is ID_PROT and for aggressive mode it is AGGRESSIVE.

Transforms

A list of proposed transforms to use for protecting the ISAKMP traffic. These are actually names for sections further describing the transforms. Look at <ISAKMP-transform> below.

<ISAKMP-transform>

ENCRYPTION_ALGORITHM

The encryption algorithm as the RFCs name it, or ANY to denote that any encryption algorithm proposed will be accepted.

KEY_LENGTH

For encryption algorithms with variable key length, this is where the offered/accepted keylengths are described. The value is of the offer-accept kind described above.

HASH_ALGORITHM

The hash algorithm as the RFCs name it, or ANY.

AUTHENTICATION_METHOD

The authentication method as the RFCs name it, or ANY.

GROUP_DESCRIPTION

The group used for Diffie-Hellman exponentiations, or ANY. The names are symbolic, like MODP_768, MODP_1024, EC_155 and EC_185.

PRF

The algorithm to use for the keyed pseudo-random function (used for key derivation and authentication in phase 1), or ANY.

Life

A list of lifetime descriptions, or ANY. In the former case, each element is in itself a name of the section that defines the lifetime. Look at <Lifetime> below. If it is set to ANY, then any type of proposed lifetime type and value will be accepted.

<Lifetime>

LIFE_TYPE

SECONDS or KILOBYTES depending on the type of the duration. Notice that this field may NOT be set to ANY.

LIFE_DURATION

An offer/accept kind of value, see above. Can also be set to ANY.

<IPsec-connection>

Phase

The constant 2, as ISAKMP-peers and IPsec-connections really are handled by the same code inside isakmpd.

ISAKMP-peer

The name of the ISAKMP-peer which to talk to in order to set up this connection. The value is the name of an <ISAKMP-peer> section. See above.

Configuration

The name of the IPsec-configuration section to use. Look at <IPsec-configuration> below.

Local-ID

If existent, the name of the section that describes the optional local client ID that we should present to our peer. It is also used when we act as responders to find out what <IPsec-connection> we are dealing with. Look at <IPsec-ID> below.

Remote-ID

If existent, the name of the section that describes the optional remote client ID that we should present to our peer. It is also used when we act as responders to find out what <IPsec-connection> we are dealing with. Look at <IPsec-ID> below.

Flags

A comma-separated list of flags controlling the further handling of the IPsec SA. Currently only one flag is defined:

Active-only

If this flag is given and this <IPsec-connection> is part of the phase 2 connections we automatically keep up, it will not automatically be used for accepting connections from the peer.

<IPsec-configuration>

DOI

The domain of interpretation as given by the RFCs. Normally IPSEC. If unspecified, defaults to IPSEC.

EXCHANGE_TYPE

The exchange type as given by the RFCs. For quick mode this is QUICK_MODE.

Suites

A list of protection suites (bundles of protocols) usable for protecting the IP traffic. Each of the list elements is a name of an <IPsec-suite> section. See below.

<IPsec-suite>

Protocols

A list of the protocols included in this protection suite. Each of the list elements is a name of an <IPsec-protocol> section. See below.

<IPsec-protocol>

PROTOCOL_ID

The protocol as given by the RFCs. Acceptable values today are IPSEC_AH and IPSEC_ESP.

Transforms

A list of transforms usable for implementing the protocol. Each of the list elements is a name of an <IPsec-transform> section. See below.

ReplayWindow

The size of the window used for replay protection. This is normally left alone. Look at the ESP and AH RFCs for a better description.

<IPsec-transform>

TRANSFORM_ID

The transform ID as given by the RFCs.

ENCAPSULATION_MODE

The encapsulation mode as given by the RFCs. This means TRANSPORT or TUNNEL.

AUTHENTICATION_ALGORITHM

The optional authentication algorithm in the case of this being an ESP transform.

GROUP_DESCRIPTION

An optional (provides PFS if present) Diffie-Hellman group description. The values are the same as GROUP_DESCRIPTION’s in <ISAKMP-transform> sections shown above.

Life

List of lifetimes, each element is a <Lifetime> section name.

<IPsec-ID>

ID-type

The ID type as given by the RFCs. For IPsec this is currently IPV4_ADDR, IPV6_ADDR, IPV4_ADDR_SUBNET or IPV6_ADDR_SUBNET.

Address

If the ID-type is IPV4_ADDR or IPV6_ADDR this tag should exist and be an IP-address.

Network

If the ID-type is IPV4_ADDR_SUBNET or IPV6_ADDR_SUBNET this tag should exist and be a network address.

Netmask

If the ID-type is IPV4_ADDR_SUBNET or IPV6_ADDR_SUBNET this tag should exist and be a network subnet mask.

Protocol

If the ID-type is IPV4_ADDR, IPV4_ADDR_SUBNET, IPV6_ADDR or IPV6_ADDR_SUBNET this tag indicates what transport protocol should be transmitted over the SA. If left unspecified, all transport protocols between the two address (ranges) will be sent (or permitted) over that SA.

Port

If the ID-type is IPV4_ADDR, IPV4_ADDR_SUBNET, IPV6_ADDR or IPV6_ADDR_SUBNET this tag indicates what source or destination port is allowed to be transported over the SA (depending on whether this is a local or remote ID). If left unspecified, all ports of the given transport protocol will be transmitted (or permitted) over the SA. The Protocol tag must be specified in conjunction with this tag.

Other sections

<IKECFG-ID>

Parameters to use with IKE mode-config. One ID per peer.

An IKECFG-ID is written as [<ID-type>/<name>]. The following ID types are supported:

IPv4

[ipv4/A.B.C.D]

IPv6

[ipv6/abcd:abcd::ab:cd]

FQDN

[fqdn/foo.bar.org]

UFQDN

[ufqdn/user [AT] foo.org]

ASN1_DN

[asn1_dn//C=aa/O=cc/...] (Note the double slashes as the DN itself starts with a ’/’.)

Each section specifies what configuration values to return to the peer requesting IKE mode-config. Currently supported values are:

Address

The peer’s network address.

Netmask

The peer’s netmask.

Nameserver

The IP address of a DNS nameserver.

WINS-server

The IP address of a WINS server.

<Initiator-ID>

During phase 1 negotiation isakmpd looks for a pre-shared key in the <ISAKMP-peer> section. If no Authentication data is specified in that section, and isakmpd is not the initiator, it looks for Authentication data in a section named after the initiator’s phase 1 ID. This allows mobile users with dynamic IP addresses to have different shared secrets.

This only works for aggressive mode because in main mode the remote initiator ID would not yet be known.

The name of the <Initiator-ID> section depends on the ID type sent by the initiator. Currently this can be:

IPv4

[A.B.C.D]

IPv6

[abcd:abcd::ab:cd]

FQDN

[foo.bar.org]

UFQDN

[user [AT] foo.org]

FILES
/etc/isakmpd/isakmpd.conf

The default isakmpd configuration file.

/usr/share/ipsec/isakmpd/

A directory containing some sample isakmpd configuration files.

EXAMPLES

An example of a configuration file:

# A configuration sample for the isakmpd ISAKMP/Oakley (aka IKE) daemon.

[General]

# Incoming phase 1 negotiations are multiplexed on the source IP address
[Phase 1]

# These connections are walked over after config file parsing and told
# to the application layer so that it will inform us when traffic wants to
# pass over them.
This means we can do on-demand keying.
[Phase 2]

# Default values are commented out.
[ISAKMP-peer-west]

#Flags=

[IPsec-east-west]

#Flags=

[Net-west]

[Net-east]

# Quick mode descriptions

[Default-quick-mode]

# Data for an IKE mode-config peer
[asn1_dn//C=SE/L=SomeCity/O=SomeCompany/CN=SomePeer.company.com]

# pre-shared key based on initiator’s phase 1 ID
[foo.bar.org]

#
# #####################################################################
# All configuration data below this point is not required as the example
# uses the predefined Main Mode transform and Quick Mode suite names.
# It is included here for completeness. Note the default values for the
# [General] and [X509-certificates] sections just below.
# #####################################################################
#

[General]

# KeyNote credential storage
[KeyNote]

# Certificates stored in PEM format
[X509-certificates]
CA-directory= /etc/isakmpd/ca/
Cert-directory= /etc/isakmpd/certs/

# Default phase 1 description (Main Mode)

[Default-phase-1-configuration]

# Main mode transforms
######################

# DES

[DES-MD5]

[DES-SHA]

# 3DES

[3DES-SHA]

# Blowfish

[BLF-SHA]

# Blowfish, using DH group 4 (non-default)
[BLF-SHA-EC185]

# Quick mode protection suites
##############################

# DES

[QM-ESP-DES-SUITE]

[QM-ESP-DES-PFS-SUITE]

[QM-ESP-DES-MD5-SUITE]

[QM-ESP-DES-MD5-PFS-SUITE]

[QM-ESP-DES-SHA-SUITE]

[QM-ESP-DES-SHA-PFS-SUITE]

# 3DES

[QM-ESP-3DES-SHA-SUITE]

[QM-ESP-3DES-SHA-PFS-SUITE]

# AES

[QM-ESP-AES-SHA-SUITE]
Protocols= QM-ESP-AES-SHA

[QM-ESP-AES-SHA-PFS-SUITE]
Protocols= QM-ESP-AES-SHA-PFS

# AH

[QM-AH-MD5-SUITE]

[QM-AH-MD5-PFS-SUITE]

# AH + ESP (non-default)

[QM-AH-MD5-ESP-DES-SUITE]

[QM-AH-MD5-ESP-DES-MD5-SUITE]

[QM-ESP-DES-MD5-AH-MD5-SUITE]

# Quick mode protocols

# DES

[QM-ESP-DES]

[QM-ESP-DES-MD5]

[QM-ESP-DES-MD5-PFS]

[QM-ESP-DES-SHA]

# 3DES

[QM-ESP-3DES-SHA]

[QM-ESP-3DES-SHA-PFS]

[QM-ESP-3DES-SHA-TRP]

# AES

[QM-ESP-AES-SHA]

[QM-ESP-AES-SHA-PFS]

[QM-ESP-AES-SHA-TRP]

# AH MD5

[QM-AH-MD5]

[QM-AH-MD5-PFS]

# Quick mode transforms

# ESP DES+MD5

[QM-ESP-DES-XF]

[QM-ESP-DES-MD5-XF]

[QM-ESP-DES-MD5-PFS-XF]

[QM-ESP-DES-SHA-XF]

# 3DES

[QM-ESP-3DES-SHA-XF]

[QM-ESP-3DES-SHA-PFS-XF]

[QM-ESP-3DES-SHA-TRP-XF]

# AES

[QM-ESP-AES-SHA-XF]

[QM-ESP-AES-SHA-PFS-XF]

[QM-ESP-AES-SHA-TRP-XF]

# AH

[QM-AH-MD5-XF]

[QM-AH-MD5-PFS-XF]

[Sample-Life-Time]

[Sample-Life-Volume]

SEE ALSO

keynote(1), ipsec(4), keynote(4), isakmpd.policy(5), isakmpd(8)

BUGS

The RFCs do not permit differing DH groups in the same proposal for aggressive and quick mode exchanges. Mixing both PFS and non-PFS suites in a quick mode proposal is not possible, as PFS implies using a DH group.

BSD August 07, 2002 BSD