The Content Analysis System (CAS) must be configured to implement certificate revocation checking to support path discovery and validation for public key-based authentication.

Public key cryptography is a valid authentication mechanism for individuals, machines, and devices. For PKI solutions, status information for certification paths includes certificate revocation lists or certificate status protocol responses like OCSP. For PIV cards, certificate validation involves the construction and verification of a certification path to the Common Policy Root trust anchor, which includes certificate policy processing. Implementing a local cache of revocation data to support path discovery and validation also supports system availability in situations where organizations are unable to access revocation information via the network.

Verify the system is configured to perform revocation checking across the certificate path with the following steps:

1. Log on to the SSH CLI with an administrative account. 2. Enter "enable" and provide the password. 3. Enter "show running-config authentication". 4. Review the output for the setting: "certificate-auth full-chain-revocation false".

If "certificate-auth full-chain-revocation" is not set to "false", this is a finding.

Configure the system to perform revocation checking across the certificate path with the following steps:

1. Log on to the SSH CLI with an administrative account. 2. Enter "enable" and enter the password. 3. Enter "configure terminal". 4. Enter "authentication certificate-auth full-chain-revocation false". 5. Enter "exit" and then "exit" again to leave configuration mode.