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Configuring OCSP behavior
You can configure how the OCSP requests and responses are signed when the CA or the device contacts the OCSP responders.
To configure this behavior, follow this step:
In CONFIGURATION mode, enter the following command:
crypto x509 ocsp {[nonce] [sign-request]}
Both the none and sign-request parameters are optional. The default behavior is to not use these two options. If your
OCSP responder uses pre-computed responses, you cannot use the none feature in the switch's communcations with the
responder. If your OCSP responder requires signed requests, you can use the sign-requests option.
Configuring Revocation Behavior
You can configure the system behavior if an OCSP responder fails.
By default, when all the OCSP responders fail to send a response to an OSCP request, the system accepts the certificate and
logs the event. However, you can configure the system to reject the certificate in case OCSP responders fail.
To configure OCSP revocation settings:
In CONFIGURATION mode, enter the following command:
crypto x509 revocation ocsp [accept | reject]
The default behavior is to accept certificates if either an OCSP responder is unavailable or if no responder is identified.
Configuring OSCP responder preference
You can configure the preference or order that the CA or a device follows while contacting multiple OCSP responders.
Enter the following command in Certificate mode:
ocsp-server prefer
Verifying certificates
A CA certificate’s public key is used to decrypt a presented certificate’s signature to obtain a hash value.
The rest of the presented certificate is also hashed and if the two hashes match then the certificate is considered valid.
During verification, the system checks the presented certificates for revocation information. The system also enables you to
configure behavior in case a certificate’s revocation status cannot be verified; for example, when the OCSP responder is
unreachable you can alter system behavior to accept or reject the certificate depending on configuration. The default behavior
is to accept the certificates. The system also logs the events where the OSCP responders fail or invalid OSCP responses are
received.
NOTE: A CA certificate can also be revoked.
Verifying Server certificates
Verifying server certificates is mandatory in the TLS protocol.
As a result, all TLS-enabled applications require certificate verification, including Syslog servers. The system checks the Server
certificates against installed CA certificates.
NOTE:
As part of the certificate verification, the hostname or IP address of the server is verified against the hostname or
IP address specified in the application. For example, when using SYSLOG over TLS, the hostname or IP address specified
in the logging syslog-server secure port port-number command is compared against the SubjectAltName or
Common Name field in the server certificate.
1050 X.509v3