man iked.conf (8): Internet Key Exchange Daemon Configuration File

DESCRIPTION

The file is used to configure iked(8) ( Internet Key Exchange Daemon ). The parameters supplied are used to negotiate ISAKMP ( phase1 ) and IPsec ( phase2 ) SAs for IPsec capable hosts.

SYNTAX

The configuration parameters are expressed as a series of sections containing a number of statements. Sections begin with a keyword optionally followed by a parameter list. All statements for a section are enclosed using the `{' and `}' characters. Statements begin with a keyword optionally followed by a parameter list and are terminated with the `;' character. Lines that begin with the `#' character are treated as comments.

Lp This document denotes keywords using this font and user supplied parameters using this font. Optional parameters are enclosed using the `[' and `]' characters. Multiple keywords that may be valid for a single parameter are enclosed using the `(' and `)' characters and separated using the `|' character.

The defined parameter types are as follows ...

number: A decimal number
label: A string comprised of alphanumeric characters
quoted: A quoted string enclosed in `' characters
address: An IP address expressed as x.x.x.x
network: An IP network and prefix length expressed as x.x.x.x/y

Daemon Section

daemon { statements }

Specifies the general configuration for iked(8) operation. This includes parameters related to the basic network configuration, log file and debug output. Only one daemon section should be defined.

socket ( ike | natt ) [ address ] number: An address and port number that should be used for ike or natt communications. If the address parameter is omitted, the daemon will attempt to bind to any address for the given port number. If no socket statements are specified, the daemon will attempt to bind to all interfaces for both ike and natt using the default port numbers ( 500 & 4500 respectively ). Note, the natt keyword can only be specified if the daemon was compiled with natt support.
retry_count number;: The number of times an exchange packet should be resent to a peer. The default value for this parameter is 2.
retry_delay number;: The number of seconds to wait between packet resend attempts. The default value for this parameter is 10.
log_file quoted: The path and file name that should be used for log output.
log_level (none | error | info | debug | loud | decode): The log output detail level. The default value for this parameter is none
pcap_decrypt quoted;: The path and file name that should be used to dump decrypted ike packets in pcap format. If no pcap_decrypt statement is specified, this feature is disabled.
pcap_encrypt quoted;: The path and file name that should be used to dump encrypted ike packets in pcap format. If no pcap_encrypt statement is specified, this feature is disabled.
dhcp_file quoted;: The path and file name that should be used to store a dhcp mac address seed value for dhcp over ipsec negotiation. If no file is present, the file will be created.

Network Group Section

netgroup label { statements }

Specifies a group of networks that can be refferred to by the assigned label. Multiple netgroup sections may be defined.

network: A network to be associated with this network group.

XAuth LDAP Section

xauth_ldap { statements }

Specifies the LDAP configuration to be used for when the xauth_source is set to ldap for a given peer section. Only one xauth_ldap section should be defined. Note, an xauth_ldap section can only be defined if the daemon was compiled with LDAP support.

version number: The LDAP protocol version to be used ( 2 or 3 ). The default value for this parameter is 3.
url quoted: The LDAP server url. For example, a url may look like "ldap://ldap.shrew.net:389".
base quoted: The base dn to be used for LDAP searches. For example, a base dn may look like "ou=users,dc=shrew,dc=net".
subtree (enable | disable);: The search scope to be used for LDAP searches. If enabled, searches will be performed using the subtree search scope. If disabled, searches will be performed using the one level search scope. The default value for this parameter is disable
bind_dn quoted;: The dn to bind as before performing LDAP searches. If this parameter is omitted, searches will be performed using anonymous binds.
bind_pw quoted;: The password to use when a bind_dn is specified.
attr_user quoted;: The attribute used to specify a user name in the LDAP directory. For example, if a user dn is "cn=user,dc=shrew,dc=net" then the attribute would be "cn". The default value for this parameter is "cn".
attr_group quoted;: The attribute used to specify a group name in the LDAP directory. For example, if a group dn is "cn=group,dc=shrew,dc=net" then the attribute would be "cn". The default value for this parameter is "cn".
attr_member quoted;: The attribute used to specify a group member in the LDAP directory. The default value for this parameter is "member".

XConf Local Section

xconf_local { statements }

Specifies the Configuration Exchange settings to be used when the xconf_source is set to local for a given peer section. Only one xconf_local section should be defined.

network4 network [number];: The network that will be used to define a local address pool. An optional number can be specified to restrict the pool to a specific size. An address from this pool along with the network mask are passed to a peer when requested.
dnss4 address;: The dns server address to be passed to a peer when requested.
nbns4 address;: The netbios name server address to be passed to a peer when requested.
dns_suffix quoted;: The dns suffix to be passed to a peer when requested.
dns_list quoted quoted ...: A list of split dns suffixes to be passed to a peer when requested. A peer can use this list to selectivly forward dns requests to the dnss4 server when a query matches one of the supplied split dns suffixes.
banner quoted;: The path to a file that contains a login banner to be passed to a peer when requested.
pfs_group number;: The pfs group number to be passed to a peer when requested.

Peer Section

peer address [ number ] { statements }

Specifies the parameters used to communicate with a given peer by address and optional port number. If the port value is omitted, the default isakmp port number will be used ( 500 ). If an address of 0.0.0.0 is used, the peer section can be used for any remote host. Multiple peer sections may be defined.

contact (initiator | responder | both)

Specifies the contact type when establishing phase1 negotiations with a peer. If initiator is used, the daemon will initiate contact but deny contact initiated by the peer. If responder is used, the daemon will allow contact initiated by the peer but will not initiate contact. If both is specified, the daemon will initiate contact and allow the peer to initiate contact.

exchange (main | aggressive)

Specifies the exchange type to be used for phase1 negotiations with a peer. The default value for this parameter is main

natt_mode (disable | enable | force [ draft | rfc ]

Specifies the NAT Traversal mode to be used for phase1 negotiations with a peer. If disable is used, natt negotiations will not be attempted. If enable is used, the daemon will attempt to negotiate and use NAT Traversal when appropriate. If force is used, the daemon will use NAT Traversal even if the peer does not negotiate support for this feature. When force is used, the draft or rfc modifiers can optionally be specified to select the required method with rfc being the default if omitted. The default value for this parameter is disable

natt_port number

Specifies the NAT Traversal port number to be used for phase1 negotiations with a peer when acting as an initiator. The default value for this parameter is 4500.

natt_rate number

Specifies the number of seconds between sending NAT Traversal keep-alive messages. The default value for this parameter is 15.

dpd_mode (disable | enable | force)

Specifies the Dead Peer Detection mode to be used with a peer. If disable is used, DPD negotiations will not be attempted. If enable is used, the daemon will attempt to negotiate and use DPD when appropriate. If force is used, the daemon will use DPD even if the peer does not negotiate support for this feature. The default value for this parameter is disable

dpd_delay number

Specifies the number of seconds between sending DPD are-you-there messages. The default value for this parameter is 15.

dpd_retry number

Specifies the number times a DPD are-you-there message will be retransmitted when no response is received. The default value for this parameter is 5.

frag_ike_mode (disable | enable | force)

Specifies the IKE Fragmentation mode to be used with a peer. If disable is used, IKE Fragmentation negotiations will not be attemted. If enable is used, the daemon will attempt to negotiate and use IKE Fragmentation when appropriate. If force is used, the daemon will use IKE Fragmentation even if the peer does not negotiate support for this feature. The default value for this parameter is disable

frag_ike_size number

Specifies the maximum number of bytes for an IKE Fragment. The default value for this parameter is 520.

frag_esp_mode (disable | enable)

Specifies the ESP Fragmentation mode to be used with a peer. If disable is used, the daemon will create IPsec SAs without the ESP Fragmentation option. If enable is used, the daemon will create IPsec SAs with the ESP Fragmentation option. The default value for this parameter is disable Note, ESP Fragmentation is only valid for IPsec SAs using NAT Traversal. The operating system must also have support for this feature. ( NetBSD Only )

frag_esp_size number

Specifies the maximum number of bytes for an ESP Fragment. The default value for this parameter is 520.

peerid (local | remote) type ...

Specifies either the local identity to be sent to a peer or the remote identity to be compared with the value received from a peer during phase1 negotiations. The valid identity types are as follows ...

address [address]: An IP Address. If the address value is omitted, the network address used during phase1 negotiations is used.
fqdn quoted: A Fully Qualified Domain Name string.
ufqdn quoted: A User Fully Qualified Domain Name string.
asn1dn [quoted]: An ASN.1 Distinguished Name string. If the quoted value is omitted, the daemon will aquire the DN from the subject field contained within the certificate.

authdata type ...

Specifies the authentication data to use during phase1 negotiations. The valid authentication data types are as follows ...

psk quoted: A Pre Shared Secret.
ca quoted [quoted];: A path to a OpenSSL PEM or PSK12 file that contains the Remote Certificate Autority. In the case where a PSK12 file is encrypted, the second quoted parameter specifies the file password.
cert quoted [quoted];: A path to a OpenSSL PEM or PSK12 file that contains the Local Public Certificate. In the case where a PSK12 file is encrypted, the second quoted parameter specifies the file password.
pkey quoted [quoted];: A path to a OpenSSL PEM or PSK12 file that contains the Local Private Key. In the case where a PSK12 file is encrypted, the second quoted parameter specifies the password.

life_check level

Specifies the behavior when validating peer lifetime proposal values. The default level is claim The valid levels are as follows ...

obey: A responder will always use the initiators value.
strict: A responder will use the initiators value if it is shorter than the responders. A responder will reject the proposal if the initiators value is greater than the responders.
claim: A responder will use the initiators value if it is shorter than the responders. A responder will use its own value if it is shorter than the initiators. In the second case, the responder will send a RESPONDER-LIFETIME notification to the initiator when responding to phase2 proposals.
exact: A responder will reject the proposal if the initiators value is not equal to the responders.

xauth_source (local | ldap) [quoted]

Sepcifies the Extended Authentication source to be used for user authentication post phase1 negotitations. The optional quoted value specifies a group name that can be used to restrict access to only users that are valid members of the group. If local is used, the peer supplied credentials will be compared to the local account database. If ldap is used, the peer supplied credentials will be compared to an LDAP account database. The LDAP source configuration is defined in the xauth_ldap section. The default value for this parameter is local

xconf_source local [(push | pull)];

Sepcifies the Configuration Exchange source to be used when responding to peer configuration requests. If local is used, the daemon will supply configuration information defined in the xconf_local section. The default value for this parameter is local

plcy_mode (disable | config | compat)

Specifies the policy generation mode. When disable is used, no policy generation is performed. When config mode is used, policy generation is performed during Configuration Exchange. This allows the daemon to generate polices using the peers private tunnel address. When compat mode is used, policy generation is performed post phase1 negotiations. This allows the daemon to interoperate with peers that do not support Configuration Exchanges.

plcy_list { statements }

Specifies a list of network groups and parameters that can be used to perform policy generation. If no plcy_list is defined but plcy_mode is set to config or compat the daemon operates as if a single include statement was used that specified a netmap defining all networks.

(include | exclude) label [quoted]: Specifies a netgroup by label for use with policy generation. When include is used, the daemon will generate appropriate IPsec policies and pass all netgroup defined networks during the Configuration Exchange if requested. A peer would use this configuration information to selectively tunnel all traffic destined for any one of these networks. If exclude is used, the daemon will generate appropriate discard policies and pass all netgroup defined networks during the Configuration Exchange if requested. A peer would use this configuration information to selectively bypass IPsec processing for all traffic destined to any one of these networks. The optional quoted string specifies a group name that can be used to restrict processing of this netgroup to only users that are valid members of the group. If XAuth is not performed, statements that define a group name are skipped.

proposal type { statements

Specifies a proposal to be used during SA negotiations with a peer. The valid proposal types are as follows ...

isakmp

An ISAKMP proposal supports the following ...

auth type: Define the authentication mechanism for the ISAKMP proposal. The accepted types are hybrid_xauth_rsa , mutual_xauth_rsa , mutual_xauth_psk , mutual_rsa and mutual_psk
ciph type [number]: Define the cipher algorithm for this proposal. The optional number specifies the keylength for algorithms that support it. The accepted types are aes , blowfish , 3des , cast and des
hash type: Define the hash algorithm for this proposal. The accepted types are md5 and sha1
dhgr number: Define the DH group for this proposal. The accepted values are 1 , 2 , 5 , 14 , 15, 16, 17, 18 and 16

ah

An AH proposal supports the following ...

hash type: Define the hash algorithm for this proposal. The accepted types are md5 and sha1
dhgr number: Define the DH group for this proposal. The accepted values are 1 , 2 , 5 , 14 , 15, 16, 17, 18 and 16

esp

An ESP proposal supports the following ...

ciph type [number]: Define the cipher algorithm for this proposal. The optional number specifies the keylength for algorithms that support it. The accepted types are aes , blowfish , 3des , cast and des
hmac type: Define the message authentication algorithm for this proposal. The accepted types are md5 and sha1
dhgr number: Define the DH group for this proposal. The accepted values are 1 , 2 , 5 , 14 , 15, 16, 17, 18 and 16

ipcomp

An IPCOMP proposal supports the following ...

comp type: Define the compression algorithm for this proposal. The accepted types are deflate and lzs

All proposals types support the following ...

life_sec number: Define the lifetime in seconds for this proposal.
life_kbs number: Define the lifetime in kilobytes for this proposal.

EXAMPLES

This section contains a few iked configuration examples.

The first example shows a configuration that only defines the parameters required to support client connectivity mode with NATT and debug options enabled.

daemon
{
    socket ike 500;
    socket natt 4500;
    log_level debug;
    log_file "/var/log/iked.log";
    pcap_decrypt "/var/log/ike-decrypt.pcap";
    pcap_encrypt "/var/log/ike-encrypt.pcap";
    retry_delay 10;
    retry_count 2;
}

The second example shows a configuration that supports simple peer to peer negotiations using mutual preshared key authentication.

daemon
{
    socket ike 500;
    log_level debug;
    log_file "/var/log/iked.log";
}
peer 1.2.3.4
{
    exchange main;
    peerid local address;
    peerid remote address;
    authdata psk "sharedsecret";
    life_check claim;
    proposal isakmp
    {
        auth mutual_psk;
        life_sec 28800;
        life_kbs 0;
    }
    proposal esp
    {
        life_sec 3800;
        life_kbs 0;
    }
}

The third example shows a configuration that supports client gateway negotiations using mutual preshared key authentication with xauth, nat traversal, dead peer detection, ike fragmentation and policy generation. The daemon would allow xauth users that are members of the "remote" group to connect to the gateway. Policies would be generated to allow a peer access to the 10.1.1.0/24 and 1.3.3.0/24 networks with the exception of 1.1.1.15/32 which be accessed directly ( not via IPsec ). Peers that use an xauth user account that is a member of the "netadmin" group would have additional policies generated to allow access to the 10.4.4.0/24 network.

daemon
{
    socket ike 500;
    socket natt 4500;
    log_level debug;
    log_file "/var/log/iked.log";
    pcap_decrypt "/var/log/ike-decrypt.pcap";
    pcap_encrypt "/var/log/ike-encrypt.pcap";
}
netgroup allow
{
    10.1.1.0/24;
    10.3.3.0/24;
}
netgroup deny
{
    1.1.1.15/32;
}
netgroup protect
{
    10.4.4.0/24;
}
xconf_local
{
    network4 10.2.1.0/24;
    dnss4 10.1.1.1;
    nbns4 10.1.1.1;
    dns_suffix "foo.com";
    dns_list "foo.com" "bar.com";
    banner "/etc/iked.motd";
    pfs_group 2;
}
peer 0.0.0.0
{
    contact responder;
    exchange main;
    natt_mode enable;
    dpd_mode enable;
    frag_ike_mode enable;
    peerid local address;
    peerid remote address;
    authdata psk "sharedsecret";
    life_check claim;
    xauth_source local "remote";
    xconf_source local;
    plcy_mode config;
    plcy_list
    {
        include allow;
        exclude deny;
        include protect "netadmin";
    }
    proposal isakmp
    {
        auth mutual_xauth_psk;
        ciph 3des;
        hash md5;
        dhgr 2;
        life_sec 28800;
        life_kbs 0;
    }
    proposal esp
    {
        life_sec 3800;
        life_kbs 0;
    }
}

HISTORY

The parser was written by Matthew Grooms ( [email protected] ) as part of the Shrew Soft ( http://www.shrew.net ) family of IPsec products.