User's Manual

Table Of Contents
Fortress ES-Series CLI Guide: Network Security, Authentication and Auditing
149
NOTE:
Incoming
OCSP traffic
requires administrative
access. If the adminis-
trative IP address ACL
(disabled by default) is
enabled, it must include
IP addresses for the
OCSP responder and
validating devices. See
Section 2.2.5 for more
detail. Traffic is affected
by the per-interface
packet filters. If config-
ured, per-interface
packet filters must
include filters to permit
OCSP traffic to and
from the FMP. See Sec-
tion 4.6.3 for more
detail.
The Mesh Point's internal RADIUS server can optionally be
configured to check the revocation status of certificates using
OCSP. In this configuration, the internal RADIUS server acts as
an OCSP client. The OCSP client function is disabled by
default.
When the OCSP client function is enabled, the internal
RADIUS server determines the current revocation status of an
X.509 digital certificate presented to it for validation, using
information obtained from either the configured OCSP
responder or the local OCSP cache. Any certificate whose
revocation status cannot be determined to be Good is rejected.
The OCSP cache serves as a backup source of revocation
information, when the configured OCSP responder cannot be
reached: a certificate’s revocation status, as obtained directly
from the configured OCSP responder, is saved whenever the
responder can be reached.
The certificate revocation status that is saved in the cache is
valid for a limited period of time, as specified by the global
ValidityPeriod. The cached revocation status of a certificate
expires at the end of its
ValidityPeriod, after which it is not
used to determine revocation status.
NOTE:
For more
detail on OCSP
Cache Operation, refer to
the Fortress Mesh Point
Software GUI Guide.
An entry for an X.509 certificate can be added to the cache
administratively, or it can be learned automatically. In either
case, the revocation status for the certificate is saved (updated
or added) to the cache, whenever it is retrieved from the
configured OCSP responder.
Administratively Added OCSP Cache Entries
When adding an OCSP cache entry administratively, the
certificate is identified by the
SearchText character string. This
must be a substring of the certificate’s Subject field—typically a
substring of the Common Name component of the Subject
field—that identifies the certificate without ambiguity.
At the time it is added, a manually entered OCSP cache entry
is marked
Not yet validated, and it is treated as though it
has expired, unless it matches a previously cached (learned)
certificate. If it matches a previously learned certificate, the
expiration time associated with the entry is left unchanged.
When the certificate matching the entry is presented for
validation, if the revocation status of the certificate can be
determined by successfully contacting the configured OCSP
responder, the entry’s
Not yet validated status is updated to
reflect the revocation status returned in OCSP response.