OCSP Response Stapling

The OCSP Response Stapling feature allows you to check the validity of a peer's user or device credentials contained in a digital certificate using Online Certificate Status Protocol (OCSP).

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.

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.

Information About OCSP Response Stapling

Overview of OCSP Response Stapling

Online Certificate Status Protocol (OCSP) is a method to check certificate revocation when a peer has to retrieve this revocation information and then validate it to check the certificate revocation status. In this method, the certification revocation status is limited by the peer's ability to reach an OCSP responder through the cloud or by the certificate sender's performance in retrieving the certificate revocation-information.

OCSP response stapling supports a new method to fetch the OCSP response for a device’s own certificates. This feature allows the device to obtain its own certificate revocation information by contacting the OCSP server and then sending this result along with its certificates directly to the peer. As a result, the peer does not require to contact the OCSP responder.

How to Configure OCSP Response Stapling

Configuring PKI Client to Request EKU Attribute

Perform this task to configure OCSP (Online Certificate Status Protocol) response stapling.

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. crypto pki trustpoint name
  4. ocsp url url
  5. eku request attribute
  6. match eku attribute
  7. revocation-check method1 [ method2 [ method3]]
  8. exit
  9. exit
  10. show cry pki counters

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:

Device> enable
Enables privileged EXEC mode.

  1. Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal
Enters global configuration mode.
Step 3

crypto pki trustpoint name

Example:

Device(config)# crypto pki trustpoint msca
Declares the trustpoint and a given name and enters ca-trustpoint configuration mode.
Step 4

ocsp url url

Example:


Device(ca-trustpoint)# ocsp url http://ocsp-server

Example:


Device(ca-trustpoint)# ocsp url http://10.10.10.1:80

Example:


Device(ca-trustpoint)# ocsp url http://[2001DB8:1:1::2]:80
The url argument specifies the URL of an OCSP server so that the trustpoint can check the certificate status. This URL overrides the URL of the OCSP server (if one exists) in the Authority Info Access (AIA) extension of the certificate. All certificates associated with a configured trustpoint are checked by the OCSP server. The URL can be a hostname, IPv4 address, or an IPv6 address.
Note 

Make sure that the OCSP request url is configured with the ocsp url url command and not with an http-proxy server.

Step 5

eku request attribute

Example:


Device(ca-trustpoint)# eku request ssh-client
Requests to include specified eku attribute in the certificate. This request, when configured on the PKI client, will be sent to the CA server during enrollment.
The attribute argument can be one of the following:

  • client-auth

  • code-signing

  • email-protection

  • ipsec-end-system

  • ipsec-tunnel

  • ipsec-user

  • ocsp-signing

  • server-auth

  • time-stamping

  • ssh-server

  • ssh-client

Step 6

match eku attribute

Example:

Device(ca-trustpoint)# match eku client-auth
Allows PKI to validate a peer certificate only if the specified attribute is present in the certificate else validation fails.
The attribute argument can be one of the following:

  • client-auth

  • code-signing

  • email-protection

  • ipsec-end-system

  • ipsec-tunnel

  • ipsec-user

  • ocsp-signing

  • server-auth

  • time-stamping

  • ssh-server

  • ssh-client

Step 7

revocation-check method1 [ method2 [ method3]]

Example:


Device(ca-trustpoint)# revocation-check ocsp none
(Optional) Checks the revocation status of a certificate.

  • crl --Certificate checking is performed by a CRL. This is the default option.

  • none --Certificate checking is ignored.

  • ocsp --Certificate checking is performed by an OCSP server.

If a second and third method are specified, each method will be used only if the previous method returns an error, such as a server being down.

Step 8

exit

Example:


Device(ca-trustpoint)# exit
Exits ca-trustpoint configuration mode and returns to global configuration mode.
Step 9

exit

Example:


Device(config)# exit
Returns to privileged EXEC mode.
Step 10

show cry pki counters

Example:


Device# show cry pki counters
(Optional) Displays the PKI counters of the device.

Configuring PKI Server to Include EKU Attributes

Perform this task to configure OCSP (Online Certificate Status Protocol) response stapling.

SUMMARY STEPS

  1. enable
  2. configure terminal
  3. ip http server
  4. crypto pki server cs-label
  5. eku request attribute
  6. exit
  7. exit
  8. show crypto pki counters

DETAILED STEPS

  Command or Action Purpose
Step 1

enable

Example:

Device> enable
Enables privileged EXEC mode.

  1. Enter your password if prompted.

Step 2

configure terminal

Example:

Device# configure terminal

Enters global configuration mode.

Step 3

ip http server

Example:


Device(config)# ip http server

Enables the HTTP server on your system.

Step 4

crypto pki server cs-label

Example:


Device(config)# crypto pki server server-pki
Defines a label for the certificate server and enters certificate server configuration mode.
Note 

If you manually generated an RSA key pair, the cs-label argument must match the name of the key pair.

Step 5

eku request attribute

Example:


Device(cs-server)# eku request ssh-server

Requests to include specified eku attribute in the certificate.

The attribute argument can be one of the following:

  • client-auth

  • code-signing

  • email-protection

  • ipsec-end-system

  • ipsec-tunnel

  • ipsec-user

  • ocsp-signing

  • server-auth

  • time-stamping

  • ssh-server

  • ssh-client

Step 6

exit

Example:


Device(cs-server)# exit

Exits cs-server configuration mode and returns to global configuration mode.

Step 7

exit

Example:


Device(config)# exit

Returns to privileged EXEC mode.

Step 8

show crypto pki counters

Example:


Device# show crypto pki counters

(Optional) Displays the PKI counters of the device.

Example

The following is sample output from the show crypto pki counters . 

Device# show crypto pki counters

PKI Sessions Started: 0
PKI Sessions Ended: 0
PKI Sessions Active: 0
Successful Validations: 0
Failed Validations: 0
Bypassed Validations: 0
Pending Validations: 0
CRLs checked: 0
CRL - fetch attempts: 0
CRL - failed attempts: 0
CRL - rejected busy fetching: 0
OCSP – fetch requests: 0
OCSP – received responses: 0
OCSP – failed attempts: 0
OCSP - staple requests: 0
AAA authorizations: 0

Additional References for OCSP Response Stapling

Related Documents

Related Topic

Document Title

Cisco IOS commands

Master Command List, All Releases

Security commands

Standards and RFCs

Standard/RFC

Title

RFC 2560

X.509 Internet Public Key Infrastructure Online Certificate Status Protocol - OCSP

RFC 4806

Online Certificate Status Protocol (OCSP) Extensions to IKEv2

RFC 5280

Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile

RFC 6187

X.509v3 Certificates for Secure Shell Authentication

RFC 6066

Transport Layer Security (TLS) Extensions: Extension Definitions

MIBs

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

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Feature Information for OCSP Response Stapling

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 OCSP Response Stapling

Feature Name

Releases

Feature Information

OCSP Response Stapling

This feature allows you to check the validity of a peer’s user or device credentials contained in a digital certificate using Online Certificate Status Protocol (OCSP).