Internet Key Exchange for IPsec VPNs Configuration Guide, Cisco IOS XE Release 3S (Cisco ASR 1000)
Certificate to ISAKMP Profile Mapping
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Certificate to ISAKMP Profile Mapping

Certificate to ISAKMP Profile Mapping

Last Updated: September 14, 2012

The Certificate to ISAKMP Profile Mapping feature enables you to assign an Internet Security Association and Key Management Protocol (ISAKMP) profile to a peer on the basis of the contents of arbitrary fields in the certificate. In addition, this feature allows you to assign a group name to those peers that are assigned an ISAKMP profile.

Finding Feature Information

Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table at the end of this module.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Prerequisites for Certificate to ISAKMP Profile Mapping

  • You should be familiar with configuring certificate maps.
  • You should be familiar with configuring ISAKMP profiles.

Restrictions for Certificate to ISAKMP Profile Mapping

  • This feature will not be applicable if you use Rivest, Shamir, and Adelman- (RSA-) signature or RSA-encryption authentication without certificate exchange. ISAKMP peers must be configured to do RSA-signature or RSA-encryption authentication using certificates.
  • When there are two or more ISAKMP profiles, each having a different trustpoint enrolled in the same certificate authority server, the responder selects the last global trustpoint. This is because trustpoints are selected in the reverse order in which they are defined globally. For the IPsec tunnel establishment to be successful for peers, the trustpoint selected by the initiator should match the trustpoint selected by the responder. All other IPsec tunnels will fail to establish connection if the trustpoints do not match.

Information About Certificate to ISAKMP Profile Mapping

Certificate to ISAKMP Profile Mapping Overview

Prior to Cisco IOS XE Release 2.1, the only way to map a peer to an ISAKMP profile was as follows. The ISAKMP identity field in the ISAKMP exchange was used for mapping a peer to an ISAKMP profile. When certificates were used for authentication, the ISAKMP identity payload contained the subject name from the certificate. If a certificate authority (CA) did not provide the required group value in the first Organizational Unit (OU) field of a certificate, an ISAKMP profile could not be assigned to a peer.

Effective with Cisco IOS XE Release 2.1, a peer can still be mapped as explained above. However, the Certificate to ISAKMP Profile Mapping feature enables you to assign an ISAKMP profile to a peer on the basis of the contents of arbitrary fields in the certificate. You are no longer limited to assigning an ISAKMP profile on the basis of the subject name of the certificate. In addition, this feature allows you to assign a group to a peer to which an ISAKMP profile has been assigned.

How Certificate to ISAKMP Profile Mapping Works

The figure below illustrates how certificate maps may be attached to ISAKMP profiles and assigned group names.

Figure 1 Certificate Maps Mapped for Profile Group Assignment


A certificate map can be attached to only one ISAKMP profile although an ISAKMP profile can have several certificate maps attached to it.

Certificate maps provide the ability for a certificate to be matched with a given set of criteria. ISAKMP profiles can bind themselves to certificate maps, and if the presented certificate matches the certificate map present in an ISAKMP profile, the peer will be assigned the ISAKMP profile. If the ISAKMP profile contains a client configuration group name, the same group name will be assigned to the peer. This ISAKMP profile information will override the information in the ID_KEY_ID identity or in the first OU field of the certificate.

Assigning an ISAKMP Profile and Group Name to a Peer

To assign an ISAKMP profile to a peer on the basis of arbitrary fields in the certificate, use the match certificate command after the ISAKMP profile has been defined.

To associate a group name with an ISAKMP profile that will be assigned to a peer, use the client configuration group command, also after the ISAKMP profile has been defined.

How to Configure Certificate to ISAKMP Profile Mapping

Mapping the Certificate to the ISAKMP Profile

To map the certificate to the ISAKMP profile, perform the following steps. This configuration will enable you to assign the ISAKMP profile to a peer on the basis of the contents of arbitrary fields in the certificate.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    crypto isakmp profile profile-name

4.    match certificate certificate-map


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router# enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
crypto isakmp profile profile-name


Example:

Router (config)# crypto isakmp profile vpnprofile

 

Defines an ISAKMP profile and enters into crypto ISAKMP profile configuration mode.

 
Step 4
match certificate certificate-map


Example:

Router (conf-isa-prof)# match certificate map1

 

Accepts the name of a certificate map.

 

Verifying That the Certificate Has Been Mapped

The following show crypto ca certificates command may be used to verify that the subject name of the certificate map has been properly configured.

SUMMARY STEPS

1.    enable

2.    show crypto ca certificates


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router# enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
show crypto ca certificates


Example:

Router# show crypto ca certificates

 

Displays information about your certificate.

 

Assigning the Group Name to the Peer

To associate a group name with a peer when the peer is mapped to an ISAKMP profile, perform the following steps.

SUMMARY STEPS

1.    enable

2.    configure terminal

3.    crypto isakmp profile profile-name

4.    client configuration group group-name


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router# enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
configure terminal


Example:

Router# configure terminal

 

Enters global configuration mode.

 
Step 3
crypto isakmp profile profile-name


Example:

Router (config)# crypto isakmp profile vpnprofile

 

Defines an ISAKMP profile and enters into isakmp profile configuration mode.

 
Step 4
client configuration group group-name


Example:

Router (conf-isa-prof)# client configuration group group1

 

Accepts the name of a group that will be assigned to a peer when the peer is assigned this crypto ISAKMP profile.

 

Monitoring and Maintaining Your Certificate to ISAKMP Profile Mapping

To monitor and maintain your certificate to ISAKMP profile mapping, you may use the following debug crypto isakmp command.

SUMMARY STEPS

1.    enable

2.    debug crypto isakmp


DETAILED STEPS
  Command or Action Purpose
Step 1
enable


Example:

Router# enable

 

Enables privileged EXEC mode.

  • Enter your password if prompted.
 
Step 2
debug crypto isakmp


Example:

Router# debug crypto isakmp

 

Displays output showing that the certificate has gone through certificate map matching and that the certificate matches the ISAKMP profile.

The command may also be used to verify that the peer has been assigned a group.

 

Configuration Examples for Certificate to ISAKMP Profile Mapping

Certificates Mapped to the ISAKMP Profile on the Basis of Arbitrary Fields Example

The following configuration example shows that whenever a certificate contains "ou = green," the ISAKMP profile "cert_pro" will be assigned to the peer:

crypto pki certificate map cert_map 10 
 subject-name co ou = green
!
!
crypto isakmp identity dn
crypto isakmp profile cert_pro 
   ca trust-point 2315 
   ca trust-point LaBcA 
   initiate mode aggressive
   match certificate cert_map 

Group Name Assigned to a Peer That Is Associated with an ISAKMP Profile Example

The following example shows that the group "some_group" is to be associated with a peer that has been assigned an ISAKMP profile:

crypto isakmp profile id_profile 
   ca trust-point 2315
   match identity host domain cisco.com
   client configuration group some_group

Mapping a Certificate to an ISAKMP Profile Verification Example

The following examples show that a certificate has been mapped to an ISAKMP profile. The examples include the configurations for the responder and initiator, the show commandoutput verifying that the subject name of the certificate map has been configured, and debug command output showing that the certificate has gone through certificate map matching and been matched to the ISAKMP profile.

Responder Configuration

crypto pki certificate map cert_map 10
! The above line is the certificate map definition.
 subject-name co ou = green
! The above line shows that the subject name must have "ou = green."
! 
crypto isakmp profile certpro
! The above line shows that this is the ISAKMP profile that will match if the certificate of the peer matches cert_map (shown on third line below).
   ca trust-point 2315
   ca trust-point LaBcA
   match certificate cert_map 
   initiate mode aggressive

Initiator Configuration

crypto ca trustpoint LaBcA
 enrollment url http://10.76.82.20:80/cgi-bin/openscep
 subject-name ou=green,c=IN
! The above line ensures that the subject name "ou = green" is set.
 revocation-check none

show crypto ca certificates Command Output for the Initiator

Router# show crypto ca certificates
Certificate
  Status: Available
  Certificate Serial Number: 21
  Certificate Usage: General Purpose
  Issuer: 
    cn=blue-lab CA
    o=CISCO
    c=IN
  Subject:
    Name: Router1.cisco.com
    c=IN
    ou=green
! The above line is a double check that "ou = green" has been set as the subject name.
    hostname=Router1.cisco.com
  Validity Date: 
    start date: 14:34:30 UTC Mar 31 2004
    end   date: 14:34:30 UTC Apr 1 2009
    renew date: 00:00:00 UTC Jan 1 1970
  Associated Trustpoints: LaBcA

debug crypto isakmp Command Output for the Responder

Router# debug crypto isakmp
6d23h: ISAKMP (0:268435460): received packet from 192.0.0.2 dport 500 sport 500 Global (R) MM_KEY_EXCH
6d23h: ISAKMP: Main Mode packet contents (flags 1, len 892):
6d23h:           ID payload
6d23h:             FQDN <Router1.cisco.com> port 500 protocol 17
6d23h:           CERT payload
6d23h:           SIG payload
6d23h:           KEEPALIVE payload
6d23h:           NOTIFY payload
6d23h: ISAKMP:(0:4:HW:2):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH
6d23h: ISAKMP:(0:4:HW:2):Old State = IKE_R_MM4  New State = IKE_R_MM5 
6d23h: ISAKMP:(0:4:HW:2): processing ID payload. message ID = 0
6d23h: ISAKMP (0:268435460): ID payload 
        next-payload : 6
        type         : 2 
        FQDN name    : Router1.cisco.com 
        protocol     : 17 
        port         : 500 
        length       : 28
6d23h: ISAKMP:(0:4:HW:2):: peer matches *none* of the profiles
6d23h: ISAKMP:(0:4:HW:2): processing CERT payload. message ID = 0
6d23h: ISAKMP:(0:4:HW:2): processing a CT_X509_SIGNATURE cert
6d23h: ISAKMP:(0:4:HW:2): peer's pubkey isn't cached
6d23h: ISAKMP:(0:4:HW:2): OU = green
6d23h: ISAKMP:(0:4:HW:2): certificate map matches certpro profile
! The above line shows that the certificate has gone through certificate map matching and that it matches the "certpro" profile.
6d23h: ISAKMP:(0:4:HW:2): Trying to re-validate CERT using new profile
6d23h: ISAKMP:(0:4:HW:2): Creating CERT validation list: 2315, LaBcA, 
6d23h: ISAKMP:(0:4:HW:2): CERT validity confirmed.

Group Name Assigned to a Peer Verification Example

The following configuration and debug output show that a group has been assigned to a peer.

Initiator Configuration

crypto isakmp profile certpro
   ca trust-point 2315
   ca trust-point LaBcA
   match certificate cert_map
   client configuration group new_group
! The statement on the above line will assign the group "new_group" to any peer that matches the ISAKMP profile "certpro." 
   initiate mode aggressive 

!

debug crypto isakmp profile Command Output for the Responder

The following debug output example shows that the peer has been matched to the ISAKMP profile named "certpro" and that it has been assigned a group named "new_group."

Router# debug crypto isakmp profile
6d23h: ISAKMP (0:268435461): received packet from 192.0.0.2 dport 500 sport 500 Global (R) MM_KEY_EXCH
6d23h: ISAKMP: Main Mode packet contents (flags 1, len 892):
6d23h:           ID payload
6d23h:             FQDN <Router1.cisco.com> port 500 protocol 17
6d23h:           CERT payload
6d23h:           SIG payload
6d23h:           KEEPALIVE payload
6d23h:           NOTIFY payload
6d23h: ISAKMP:(0:5:HW:2):Input = IKE_MESG_FROM_PEER, IKE_MM_EXCH
6d23h: ISAKMP:(0:5:HW:2):Old State = IKE_R_MM4  New State = IKE_R_MM5 
6d23h: ISAKMP:(0:5:HW:2): processing ID payload. message ID = 0
6d23h: ISAKMP (0:268435461): ID payload 
        next-payload : 6
        type         : 2 
        FQDN name    : Router1.cisco.com 
        protocol     : 17 
        port         : 500 
        length       : 28
6d23h: ISAKMP:(0:5:HW:2):: peer matches *none* of the profiles
6d23h: ISAKMP:(0:5:HW:2): processing CERT payload. message ID = 0
6d23h: ISAKMP:(0:5:HW:2): processing a CT_X509_SIGNATURE cert
6d23h: ISAKMP:(0:5:HW:2): peer's pubkey isn't cached
6d23h: ISAKMP:(0:5:HW:2): OU = green
6d23h: ISAKMP:(0:5:HW:2): certificate map matches certpro profile
6d23h: ISAKMP:(0:5:HW:2): Trying to re-validate CERT using new profile
6d23h: ISAKMP:(0:5:HW:2): Creating CERT validation list: 2315, LaBcA, 
6d23h: ISAKMP:(0:5:HW:2): CERT validity confirmed.
6d23h: ISAKMP:(0:5:HW:2):Profile has no keyring, aborting key search
6d23h: ISAKMP:(0:5:HW:2): Profile certpro assigned peer the group named new_group

Additional References

Related Documents

Related Topic

Document Title

Configuring ISAKMP profiles

VRF-Aware IPSec

Security commands

Cisco IOS Security Command Reference

Standards

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Title

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MIBs

MIBs

MIBs Link

None

To locate and download MIBs for selected platforms, Cisco IOS XE releases, and feature sets, use Cisco MIB Locator found at the following URL:

http://www.cisco.com/go/mibs

RFCs

RFCs

Title

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Technical Assistance

Description

Link

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Feature Information for Certificate to ISAKMP Profile Mapping

The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.

Table 1 Feature Information for Certificate to ISAKMP Profile Mapping

Feature Name

Releases

Feature Information

Certificate to ISAKMP Profile Mapping

Cisco IOS XE Release 2.1

This feature enables you to assign an ISAKMP profile to a peer on the basis of the contents of arbitrary fields in the certificate. In addition, this feature allows you to assign a group name to those peers that are assigned an ISAKMP profile.

The following commands were introduced or modified: client configuration group, match certificate (ISAKMP).

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Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.

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