/usr/bin/crlrefresh
Crlrefresh is a UNIX command-line program which is used to refresh and update the contents of the system-wide cache of Certificate Revocation Lists (CRLs). Crlrefresh examines the contents of the CRL cache and updates - via network fetch - all CRLs which are currently, or will soon be, invalid. Crlrefresh is also use to fetch specific CRLs and certificates from the network.